JPH08154155A - Document reading apparatus and optical axis adjusting method for imaging lens - Google Patents

Abstract

(57) [Summary] [Object] To provide a document reading apparatus and an optical axis adjusting method for an imaging lens that can obtain a high-quality image by eliminating the optical axis shift of the imaging lens to improve the imaging performance. A light flux from the wave light illuminating means 12 is guided to a minute opening portion 14 of a light flux regulating member 13 to generate a diffraction pattern, and while the diffraction pattern is observed by the pattern display means 15, the imaging lens 8 is adjusted and virtual. The lens optical axis C of the imaging lens 8 is moved and adjusted using the imaging lens optical axis adjusting means so that the diffraction patterns with and without the optical axis E are aligned. The lens optical axis C of the image lens 8 and the optical axis of the light beam emitted from the illuminating means are made to coincide with each other, thereby eliminating the deviation of the incident optical axis with respect to the imaging lens 8 and enhancing the imaging performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document reading apparatus and an optical axis adjusting method for an imaging lens.

[0002]

2. Description of the Related Art As a conventional document reading device, a transmissive document reading device using a CCD line sensor will be described as an example. FIG. 2 shows an example of the configuration of the reading optical system of the document reading device. Device body 1 that constitutes the reading optical system
A light source 2 as an illuminating unit is provided in the upper part of the inside, and light emitted from the light source 2 is folded back by a cold mirror 3 to illuminate a document 4. This manuscript 4
Is sandwiched between the contact glass 5 and the pressing glass 6 without any gap. Then, the light flux A transmitted through the original 4 is
The light is reflected by the mirror 7 and is incident on the imaging lens 8, which is focused and focused on a CCD line sensor 9 (hereinafter, referred to as CCD) as a light receiving means to read an original image. The projection distance between the imaging lens 8 and the CCD 9 is L. The bottom of the device body 1 is
It is said to be base 10.

As an actual reading operation, scanning is performed in the sub-scanning direction (arrow direction) at a speed corresponding to the reading resolution by the carriage 11 in which the contact glass 5 and the pressing glass 6 are integrally formed, and the CCD 9 is used. The two-dimensional reading scanning by the scanning in the main scanning direction (the sensor array direction orthogonal to the sub-scanning direction) is simultaneously performed to perform the actual reading. In this case, if all the assembled and adjusted optical members are arranged at the design position (ideal position), the optical axis B of the light flux A and the lens optical axis C of the imaging lens 8 are completely coincident, and the light flux Since A is incident on the image forming lens 8 vertically, high-quality image reading can be performed.

[0004]

In a digital document reading device using the CCD 9, as a means for improving image quality, the reading line on the surface of the document 4 and the reading line of the CCD 9 are adjusted to match each other. Is essential. Especially in recent years, in order to obtain high resolution, CCD
There is also an apparatus in which a plurality of 9s are arranged in the reading line direction (main scanning direction) to increase the number of read pixels. In such a document reading device in which a plurality of CCDs 9 are arranged, in order to match the reading line on the surface of the document 4 with the reading line of the CCD 9, not only the adjustment of the connection of the reading lines in the sub-scanning direction but also the main adjustment is performed. It is also necessary to adjust the connection of reading lines in the scanning direction.

As a typical example of the publicly known examples relating to such connection adjustment of reading lines, Japanese Patent Publication No. 55-180.
There are techniques described in Japanese Patent Application Laid-Open No. 96-96, and Japanese Patent Application Laid-Open No. 59-122171. In Japanese Examined Patent Publication No. 55-18096, connection adjustment of reading lines is performed by finely adjusting the relative position between each CCD and the imaging lens in the main scanning direction and the sub scanning direction using a screw and a spring. . Further, in JP-A-59-122171, the CCD and the imaging lens are modularized, and the adjustment amount of the module is made equal to the deviation amount of the reading line on the original surface to adjust the connection of the reading lines. There is.

In the conventional document reading apparatus as described above, if a certain point on the document surface and the CCD are relatively misaligned within the range of lens performance, the image is obliquely incident on the imaging lens and the lens is moved. Even if it was off the optical axis, it was still reading. However, it is ideal that the chief ray that connects a certain point on the document surface to the CCD is incident perpendicularly to the imaging lens and coincides with the lens optical axis, and if it deviates from the lens optical axis. , The variation of the aberration of each imaging lens becomes large,
The imaging performance is deteriorated. Such a reduction in image forming performance causes a reduction in image quality, which is a serious problem in the fields of printing and plate making that require high-quality image reading. Further, in the case of using a plurality of sets in which one CCD is associated with one imaging lens as in the known example, when the reading lines on the original surface are divided and read, the lenses having the same performance are used. However, the imaging performance varies depending on the location of each light flux passing through each lens, and the image quality differs for each divided reading width.

In the case where a right-angle mirror is inserted between the image forming lens and the CCD and two CCDs are associated with one image forming lens so that the reading line on the original surface is divided into two and read ( According to Japanese Patent Laid-Open No. 57-87277), if the illuminance peak position of the light source on the document surface, the reading position, the lens optical axis, the vertex of the right-angled mirror, etc. are not all the same or substantially the same, the light is incident on each CCD. The light flux causes not only the imaging performance but also the absolute light amount, the light amount distribution, the reading width, and the like, which considerably deteriorates the image quality.

[0008]

According to a first aspect of the present invention, an original is illuminated by an illuminating means, a light flux containing read information of the original is guided to an image forming lens by this illumination, and the image forming lens combines the light. In an original reading device for reading the read information of the original by forming an image of the imaged light flux on a light receiving means, a wave light (laser light or the like) is provided on an adjustment virtual optical axis on either side of the entrance and exit of the imaging lens. ) Is provided, and the wave light emitted from the wave light illumination means is provided on the adjusted virtual optical axis on the side opposite to the wave light illumination means of the entrance and exit of the imaging lens. A light flux regulating member having a minute aperture for regulating is provided, pattern display means for receiving and displaying a diffraction pattern generated by the light flux regulating member is provided, and the lens optical axis of the imaging lens is adjustable. like It provided an imaging lens optical axis adjusting means for lifting.

According to a second aspect of the present invention, in the first aspect of the invention, at least two light flux regulating members are arranged on either side of the entrance and exit of the imaging lens, and the side opposite to the wave light illumination means. The adjustment was made on the virtual optical axis.

In the invention of claim 3, claim 1 or 2
In the invention described above, the light flux regulating member is arranged on the adjusted virtual optical axis on the same side as the wave light illumination means arranged on either side of the entrance and exit of the imaging lens.

According to a fourth aspect of the present invention, in the first, second or third aspect of the invention, at least one light flux regulating member is arranged at a position substantially equal to the image plane position of the imaging lens or a position substantially equal to the image plane distance thereof. I set it up.

According to the invention of claim 5, claims 1, 2,
In the invention described in 3 or 4, the apparatus main body is provided with a positioning means for aligning or substantially aligning a line connecting the centers of the respective minute apertures formed by at least two light flux regulating members with the adjusted virtual optical axis of the imaging lens. I installed it.

According to the invention of claim 6, claims 1, 2 and
In the invention described in 3 or 4, a minute opening portion that regulates the light flux from the wave light illuminating means is formed in the apparatus main body at a position that intersects the adjusted virtual optical axis of the imaging lens.

According to the invention described in claim 7, claims 1, 2,
In the invention described in 3 or 4, at least one light flux regulating member is arranged at a position on the adjustment virtual optical axis of the imaging lens and outside the apparatus main body.

In the invention described in claim 8, claims 1, 2,
In the invention described in 3, 4, 5, 6 or 7, the adjustment virtual optical axis of the imaging lens and the optical axis of the light flux of the wave light illuminating means passing through the minute opening are aligned or substantially aligned with each other. The wave light optical axis adjusting means for adjusting the optical axis of the light flux of the wave light illuminating means is provided.

According to the invention of claim 9, claims 1, 2 and
In the invention described in 3, 4, 5, 6, 7 or 8, the center position of the minute opening is set so that the adjusted virtual optical axis of the imaging lens and the center position of the minute opening match or substantially match. An opening center position adjusting means for adjusting is provided.

According to the invention of claim 10,
In the invention described in 2, 3, 4, 5, 6, 7, 8 or 9, at least the light flux regulating member and the lens holding member that holds the imaging lens are provided on at least the same constituent member (base or the like) of the apparatus main body. Arranged.

According to the invention of claim 11, claim 1
In the invention described in 2, 3, 4, 5, 6, 7, 8, 9, or 10, the installation portion of the component member (base or the like) of the apparatus main body in which the lens holding member for holding the imaging lens is installed, and A high-rigidity means is applied to the peripheral portion.

According to the invention of claim 12,
In the invention described in 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11, the adjustment virtual on the side opposite to the wave light illumination means arranged on either side of the entrance and exit of the imaging lens. A light flux regulating member movement adjusting means for moving the light flux regulating member arranged on the optical axis in the adjustment virtual optical axis direction is provided.

According to the invention described in claim 13,
2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12
In the described invention, the light receiving monitor is used as the pattern display means for receiving and displaying the diffraction pattern.

According to the invention of claim 14, claim 1
In the invention described in 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 13, projection position movement adjusting means for adjusting the projection position by moving the pattern display means in the adjustment virtual optical axis direction. Was set up.

According to the invention of claim 15, claim 1,
2,3,4,5,6,7,8,9,10,11,12,
In the invention described in 13 or 14, at least aperture changing means for changing the size of the minute aperture of the light flux regulating member is provided.

According to the invention of claim 16, claim 1
2,3,4,5,6,7,8,9,10,11,12,
In the invention described in 13, 14, or 15, the opening / projection position varying means for varying at least the size of the minute opening of the light flux regulating member and the projection distance from the minute opening to the pattern display means is provided.

According to the invention of claim 17, claim 1
2,3,4,5,6,7,8,9,10,11,12,
In the invention described in 13, 14, 15 or 16, at least the wave light illuminating means, the optical axis of the light flux of the wave light illuminating means, and the adjusted virtual optical axis of the imaging lens coincide with each other on the optical axis adjusting table, or Positioning means for positioning the constituent members (base, etc.) of the apparatus main body holding the imaging lens so as to substantially coincide with each other are provided, and the constituent members are detachable from the optical axis adjusting table.

In the eighteenth aspect of the present invention, the light flux regulating member is arranged so that the adjusted virtual optical axis of the imaging lens and the center of the minute aperture of the light flux regulating member having the minute aperture coincide or substantially coincide with each other. The first optical axis adjusting step of positioning inside the apparatus main body and the wave so that the center of the minute opening and the optical axis of the wave light illuminating means for emitting wave light (laser light etc.) coincide or substantially coincide with each other. A second optical axis adjusting step of adjusting and positioning the position of the light illuminating means using a diffraction pattern, and the diffraction pattern before the image forming lens is arranged on the adjusted virtual optical axis and the image forming lens is interposed And a third optical axis adjusting step of adjusting the optical axis of the imaging lens so that both diffraction patterns coincide or substantially coincide with each other.

In the nineteenth aspect of the present invention, the adjustment virtual optical axis of the imaging lens and the center of the minute aperture of the first light flux regulating member having the minute aperture are aligned or substantially aligned with each other. A first optical axis adjusting step of positioning one light flux regulating member inside the apparatus main body; and a wave light illuminating means for emitting wave light (laser light or the like) to the center of the minute opening of the first light flux regulating member. So that the optical axes match or almost match,
A second optical axis adjusting step for adjusting and positioning the position of the wave light illuminating means by using a diffraction pattern, and a position on the adjusted virtual optical axis different from the position where the first light flux regulating member is arranged. A second light flux restricting member is disposed inside or outside the device main body, and the center of the minute opening of the second light flux restricting member and the optical axis of the light flux of the wave light illumination means coincide or substantially coincide with each other. As described above, the third optical axis adjusting step of adjusting and positioning the position of the second light flux regulating member, and the step of arranging the imaging lens on the adjusted virtual optical axis and interposing this imaging lens And a fourth optical axis adjusting step of adjusting the optical axis of the imaging lens so that both the diffraction patterns are matched or substantially matched with each other. .

According to a twentieth aspect of the invention, in the eighteenth or nineteenth aspect of the invention, at least the minimum member necessary for the optical axis adjustment is provided at the stage before the optical axis adjustment is performed by the optical axis adjusting step. A process for assembling the main body inside was provided.

According to a twenty-first aspect of the invention, in the eighteenth or nineteenth aspect of the invention, among the constituent members of the apparatus main body, at least the imaging lens, the light receiving means, and the light flux of the wave light illuminating means are shielded when the optical axis is adjusted. The members that can be detached are detachable, and the constituent members excluding these detachable members are
A main body assembling step for assembling inside the main body of the apparatus is provided before the optical axis adjustment by the optical axis adjusting step.

According to a twenty-second aspect of the present invention, in the twenty-first aspect of the present invention, among the constituent members of the apparatus main body, an opening is formed in a member that shields a light beam from the wave light illuminating means at the time of adjusting the optical axis. The light flux is passed through this opening to adjust the optical axis.

[0030]

According to the first aspect of the invention, the wave light such as the laser light emitted from the wave light illuminating means disposed on the adjustment virtual optical axis on either side of the entrance and exit of the imaging lens is combined. Moving on the adjusted virtual optical axis of the image lens, and entering the minute aperture of the light flux regulating member disposed on the adjusted virtual optical axis on the side opposite to the wave light illumination means for entering and exiting the imaging lens. A diffraction pattern is generated by this, and the generated diffraction pattern is received by the pattern display means and displayed. At this time, the imaging lens optical axis adjusting means is used while observing the diffraction pattern when the imaging lens displayed by the pattern display means is interposed on the adjusted virtual optical axis and the diffraction pattern when not interposed. By adjusting the lens optical axis of the imaging lens by adjusting the two patterns,
Thereby, the lens optical axis of the imaging lens can be matched with the adjusted virtual optical axis.

According to the second aspect of the invention, the wave light such as the laser light emitted from the wave light illuminating means is opposite to the wave light illuminating means arranged on either side of the entrance and exit of the imaging lens. The diffraction patterns obtained by passing through the minute apertures of at least two light flux regulating members arranged on the adjustment virtual optical axis on the side and obtained by passing through the plurality of minute apertures are received by the pattern display means and displayed. . At this time, the lens optical axis of the imaging lens is adjusted so that the light flux passing through the imaging lens passes through the plurality of minute openings.

According to the third aspect of the present invention, the wave light such as laser light emitted from the wave light illuminating means is on the same side as the wave light illuminating means arranged on either side of the entrance and exit of the imaging lens. After passing through the minute opening of the light flux regulating member arranged on the adjusted virtual optical axis, the light flux regulating member arranged on the adjusted virtual optical axis on the side opposite to the wave light illuminating means for entering and exiting the imaging lens. The diffraction pattern obtained by passing through the minute openings of the above is received by the pattern display means and displayed. At this time, the position of the wave light illumination means serving as a reference for the optical axis adjustment is always checked by the minute opening arranged on the adjustment virtual optical axis on the same side as the incident / emitted wave light illumination means of the imaging lens. .

According to the invention described in claim 4, the diffraction pattern obtained by passing through the light flux restricting member arranged at a substantially image plane position of the imaging lens or a position substantially equal to the image plane distance is used. By adjusting the optical axis of the image lens, it is possible to perform adjustment suitable for a device that allows a slight deviation of the optical axis of the imaging lens.

According to the fifth aspect of the present invention, at least two light flux regulating members are positioned by using the positioning means attached to the apparatus main body, so that each minute opening formed by the positioned light flux regulating members. The line connecting the centers of the two can be matched or substantially matched with the adjusted virtual optical axis of the imaging lens, which allows the adjusted virtual optical axis, which is the reference for the optical axis adjustment, to be set easily and with high accuracy. Can be seen.

In the sixth aspect of the invention, the light flux from the wave light illuminating means enters the inside of the main body through a minute opening formed in the main body of the apparatus, and advances along the adjusted virtual optical axis of the imaging lens. Then, the light is emitted to the outside of the main body from a minute opening formed in another apparatus main body, and the diffraction pattern generated thereby is displayed on the pattern display means. By forming the minute opening in the main body of the apparatus as described above, the optical axis of the imaging lens can be easily adjusted at any time without installing the light flux regulating member inside the main body.

In the seventh aspect of the invention, the light flux regulating member is arranged at a position outside the main body of the apparatus to adjust the optical axis of the imaging lens, so that the light flux regulating member is assembled on the adjusted virtual optical axis. The attaching workability becomes easy.

In the eighth aspect of the present invention, the optical axis of the light beam emitted from the wave light illumination means is made to coincide or substantially coincide with the adjusted virtual optical axis of the imaging lens by using the wave light optical axis adjusting means. It is possible to quickly and highly accurately cope with an optical axis shift in the initial stage of emission of the light flux of the wave light illuminating means and an optical axis shift caused by a change over time.

In the ninth aspect of the invention, the optical axis adjustment is further performed by using the opening center position adjusting means to match or substantially match the center position of the minute opening with the adjusted virtual optical axis of the imaging lens. It will be easier and you can easily perform high-precision positioning.

According to the tenth aspect of the present invention, at least the light flux regulating member and the lens holding member are arranged on at least the same component member such as the base of the apparatus main body, so that the processing accuracy and the molding accuracy of the mounting portions can be improved. It can be expensive.

According to the eleventh aspect of the present invention, the high rigidity means is provided in the installation portion area of the constituent member such as the base on which the lens holding member is installed, so that the weight of the imaging lens and the lens holding member is reduced. It is possible to prevent flexure of constituent members such as the base of the apparatus body.

In the twelfth aspect of the invention, the light flux regulating member movement adjusting means is used to regulate the light flux located on the opposite side of the wave light illuminating means disposed on either side of the entrance and exit of the imaging lens. By moving the member along the direction of the adjusted virtual optical axis, it is possible to eliminate the blurring of the diffraction pattern displayed after passing through the light flux regulating member and obtain a clear pattern.

According to the thirteenth aspect of the present invention, the state of the diffraction pattern is used as a pattern display means by a light receiving monitor, for example, a CCD camera, to receive the light, so that the diffraction pattern is objectively evaluated, not by the subjective evaluation of a person. You can observe it and adjust it.

In the fourteenth aspect of the present invention, the projection position movement adjusting means is used to move the pattern display means along the adjustment virtual optical axis direction to adjust the projection position, whereby the projected diffraction pattern While observing the amount and size of light, it is possible to create the optimum pattern state for adjusting the optical axis.

According to the fifteenth aspect of the present invention, the amount of light of the diffraction pattern and the size thereof can be delicately controlled by changing the size of at least the minute opening using the opening changing means.

In the sixteenth aspect of the present invention, at least the size of the minute opening and the projection distance from the minute opening to the pattern display means are simultaneously changed by using the opening / projection position changing means. As a result, the control range of the light quantity and size of the diffraction pattern can be expanded.

In the seventeenth aspect of the invention, at least the wave light illuminating means and the positioning means for positioning the constituent members of the apparatus body such as the base holding the imaging lens are provided on the optical axis adjusting table. When the optical axis of the imaging lens is adjusted for the second time and thereafter by adjusting the optical axis of the imaging lens by the diffraction pattern, the constituent members of the apparatus main body such as the base holding the imaging lens are fixed to the positioning means, All you have to do is adjust the movement of the imaging lens.
High-precision positioning can always be performed in any adjustment environment.

In the eighteenth aspect of the present invention, the light flux regulating member is positioned inside the main body of the apparatus in the first optical axis adjusting step, and the adjusted virtual optical axis of the imaging lens and the center of the minute opening of the light flux regulating member are set. In the second optical axis adjusting step, the center of the minute aperture and the optical axis of the light beam of the wave light illuminating means are made to match or substantially match, and the imaging lens is moved in the third optical axis adjusting step. By comparing the diffraction patterns before and after interposing and matching or substantially matching both diffraction patterns,
The optical axis adjustment work of the imaging lens can be performed smoothly and efficiently.

In the nineteenth aspect of the invention, the first light flux regulating member is positioned inside the apparatus main body in the first optical axis adjusting step, and the adjusted virtual optical axis of the imaging lens and the first light flux regulating member are arranged. The center of the minute opening is matched or substantially matched, and the center of the minute opening of the first light flux regulating member and the optical axis of the light flux of the wave light illumination means are matched or substantially matched in the second optical axis adjusting step. In the third optical axis adjusting step, the second light flux regulating member is disposed inside or outside the device body, and the center of the minute opening of the second light flux regulating member and the optical axis of the light flux of the wave light illumination means are arranged. Are matched or substantially matched, and the diffraction patterns before and after interposing the imaging lens in the fourth optical axis adjusting step are compared to match or substantially match both diffraction patterns, thereby Optical axis adjustment work can be performed smoothly and efficiently.

In the invention of claim 20, first,
According to the body assembling process, at least the minimum number of members necessary for adjusting the optical axis of the imaging lens is assembled, then the optical axis of the imaging lens is adjusted according to the optical axis adjusting process, and then,
All of the remaining components were fully assembled into the device body.

In the twenty-first aspect of the invention, first,
According to the main body assembling step, assembling the constituent members of the main body of the apparatus except at least the imaging lens, the light receiving means, and the member that blocks the light flux of the wave light illuminating means at the time of adjusting the optical axis. Therefore, at the stage of the optical axis adjustment process, the weight of the apparatus main body is set to a state close to the actual use level to perform the optical axis adjustment.

According to the twenty-second aspect of the present invention, among the constituent members of the apparatus main body, an opening is provided in a member that shields the light flux from the wave light illumination means when the optical axis is adjusted. The emitted light flux passes through the opening, is guided to the adjustment virtual optical axis of the imaging lens, and is used as a light flux for adjusting the optical axis of the imaging lens.

[0052]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. 1 to 4 (corresponding to the invention of claim 1). In this embodiment, a transmissive original reading device (see FIG. 2) using the CCD 9 as described in the related art will be described as an example. The description of the same parts in the main body 1 of the reading optical system is omitted.

FIG. 1 shows the structure of an optical system for adjusting the optical axis of the imaging lens 8. A laser light source 12 as a wave light illuminating means is arranged on the incident side of the imaging lens 8,
A light flux regulating member 13 (hereinafter referred to as a pinhole) is arranged on the exit side thereof. A small hole 14 as a minute opening is formed at the center of the pinhole 13. Further, behind the pinhole 13, an observation plate 15 as a pattern display means for receiving and displaying the generated diffraction pattern K is arranged. In this case, the optical axis D of the laser light emitted from the laser light source 12 and the center position of the small hole 14 of the pinhole 13 are located on the adjusted virtual optical axis E. The adjusted virtual optical axis E here is not actually visible, but is an imaginary one that is used for convenience during design and adjustment. The adjusted virtual optical axis E finally corresponds to the optical axis B of the light flux A from the light source 2.

The image forming lens 8 is movably supported by an image forming lens optical axis adjusting means (not shown) such as a spacer or a micro head. With this imaging lens optical axis adjusting means, the lens optical axis C of the imaging lens 8 can be moved and adjusted so as to coincide with the adjusted virtual optical axis E.

In such a structure, the diffraction pattern K
A method of adjusting the movement of the lens optical axis C of the imaging lens 8 by utilizing the optical phenomenon described in (3) will be described. First, at a stage before installing the imaging lens 8 in the apparatus main body 1, the laser light emitted from the laser light source 12 is applied to the small hole 1 of the pinhole 13.
4, the diffraction pattern K generated by passing through the pinhole 13 is received by the observation plate 15 and projected. In this case, since the optical axis D of the laser light, the center of the small hole 14 and the adjusted virtual optical axis E coincide with each other, the diffraction pattern is centered on the position of the point P where the adjusted virtual optical axis E intersects the observation plate 15. K is formed. This projected diffraction pattern K
As shown in FIG. 3, the light intensity distribution is concentric, and the light amount distribution decreases uniformly from the center to the outside. The shape and position of the diffraction pattern K centering on the point P is used as a reference for adjusting the optical axis.

Next, the imaging lens 8 is set at a predetermined position in the apparatus main body 1, that is, at a position substantially corresponding to the optical axis B of the light beam A from the light source 2. In this installed state, the laser light is guided to the imaging lens 8 and the diffraction pattern K obtained by passing through the pinhole 13 is projected on the observation plate 15 for observation. If the shape and position of the projected diffraction pattern K is the same as the reference diffraction pattern K, the adjusted virtual optical axis E, which is the designed position, and the lens optical axis C of the imaging lens 8 coincide with each other. Therefore, it is not necessary to adjust the optical axis of the imaging lens 8. However, when the shape or position of the projected diffraction pattern K does not match the shape or position of the reference diffraction pattern K and, for example, as shown in FIG. Means that the lens optical axis C of the imaging lens 8 is deviated from the adjusted virtual optical axis E, so that the optical axis adjustment is necessary. This optical axis adjustment is performed by shifting the imaging lens 8 in the X and Y directions by using the imaging lens optical axis adjusting means so that the projected diffraction pattern K matches the reference diffraction pattern K. : Vertical direction with respect to the paper surface of FIG. 1, Y: vertical direction with respect to the paper surface of FIG. 1, and inclinations in the Xθ and Yθ directions (Xθ: X
Direction rotation, Yθ: Y direction rotation) is adjusted. In this case, the adjustment is performed in consideration of the property that when the imaging lens 8 is shifted, the light emitted from the lens is tilted, and conversely, when the imaging lens 8 is tilted, the light emitted from the lens is shifted. Then, it is possible to easily grasp the location (direction) to be adjusted and the adjustment amount. After the optical axis adjustment is completed in this way, the imaging lens 8 is fixed so as not to move except in the optical axis direction (Z direction).

As described above, by using the optical axis adjusting means of the imaging lens and utilizing the optical phenomenon called the diffraction pattern K,
By adjusting the lens optical axis C of the imaging lens 8 so as to match the adjusted virtual optical axis E, that is, the design position, the lens optical axis C of the imaging lens 8 and the optical axis B of the light beam A emitted from the light source 2 are adjusted. It is possible to match them, and it is possible to eliminate the optical axis deviation. As a result, the light flux A of the light source 2 is incident on the imaging lens 8 vertically without being inclined, so that the imaging performance can be improved and the image quality can be further improved. Therefore, it is possible to provide a high-quality document reading device. In the embodiment, the laser light source 12 is installed on the entrance side of the imaging lens 8 and the pinhole 13 is installed on the exit side. However, the laser light source 1 is arranged on the opposite side, that is, on the exit side of the imaging lens 8.
2. Even if the pinhole 13 is installed on the incident side, the same adjustment can be performed.

Next, a second embodiment of the present invention will be described based on FIG. 5 (corresponding to the invention described in claim 2). The description of the same parts as in the first embodiment is omitted,
The same reference numerals are used for the same portions.

On the adjusted virtual optical axis E between the pinhole 13 on the exit side of the imaging lens 8 and the observation plate 15, a pinhole 16 as a light flux regulating member is arranged. A small hole 17 is formed in the pinhole 16, and the center position of the small hole 17 coincides with the adjusted virtual optical axis E.

The amount of deviation of the diffraction pattern K obtained from the pinhole 13 from the reference position can be determined by observing the amount of deviation from the point P on the observation plate 15, but it cannot be said to be sufficient in terms of accuracy. . Therefore, the lens optical axis C of the imaging lens 8 is moved so that the laser light passing through the imaging lens 8 passes through the small holes 14 and 17 of the pinholes 13 and 16 which coincide with the adjusted virtual optical axis E. adjust. In this case, the diffraction pattern K does not occur unless the laser light passes through the two small holes 14 and 17, so there is no need to consider the positional deviation from the reference point P on the observation plate 15 at all. While observing only the pattern shape, the lens optical axis C is adjusted so as to finally obtain the diffraction pattern K as shown in FIG. As a result, the optical axis adjustment accuracy can be further improved as compared with the case where only one pinhole 13 is arranged. The number of pinholes arranged on the exit side of the imaging lens 8 is 2
However, the number of pinholes is not limited to one, and three or more pinholes are arranged further away from the observation plate 15, so that the optical axis can be adjusted with higher accuracy. However, in this case, it is necessary to set the output power of the laser light source 12 high.

Next, a third embodiment of the present invention will be described with reference to FIGS. 6 and 7 (corresponding to the invention of claim 3). It should be noted that the description of the same parts as those in the above-mentioned respective embodiments is omitted, and the same reference numerals are used for the same parts.

On the adjusted virtual optical axis E between the laser light source 12 and the incident side of the imaging lens 8, a pinhole 18 as a light flux regulating member is arranged. A small hole 19 is formed in the pinhole 18, and the center position of the small hole 19 coincides with the adjusted virtual optical axis E.

In such a configuration, the laser light source 12
If the laser light from the laser does not pass through the pinhole 18 on the lens entrance side and the pinhole 13 on the lens exit side, the diffraction pattern K projected on the observation plate 15 is not generated. This means that, for example, when the laser light source 12 is slightly tilted due to an unexpected external force or stress during the adjustment in which the lens optical axis C of the imaging lens 8 matches the adjusted virtual optical axis E, the It means that the inclination appears as a difference in the diffraction pattern shape. From this, with the imaging lens 8 removed, the laser light from the laser light source 12 is passed through the two pinholes 18 and 13, and the diffraction pattern K is observed to determine the position of the laser light source 12. Can be checked at all times. As a result, it is possible to perform the optical axis adjustment more highly accurately and without variations.

Further, the wider the distance between the pinhole 13 and the pinhole 18, the higher the accuracy of tilt adjustment of the laser light source 12 can be set. Further, the number of pinholes arranged on the adjusted virtual optical axis E is not particularly limited, and for example, three pinholes 13, 16, 18 as shown in FIG. 7 which is a combination of FIG. 5 and FIG. By using the configuration (1 on the incident side and 2 on the emitting side) using the, the number of pinholes is the smallest among the configurations capable of adjusting the laser optical axis C and adjusting the tilt of the laser light source 12. The reduction rate of the light amount of light can also be minimized, which allows the optical axis to be adjusted with higher accuracy.

Next, a fourth embodiment of the present invention will be described with reference to FIG. 8 (corresponding to the invention of claim 4). It should be noted that description of the same parts as those in each of the above-described embodiments is omitted,
The same reference numerals are used for the same portions.

The small hole 14 of the pinhole 13 is located at a position substantially equal to the image plane position of the imaging lens 8 or its image plane distance L (that is, a position equal to or substantially equal to the light receiving position of the CCD 9). It is located in.

Even if the optical axis C of the imaging lens 8 is shifted and the optical axis B of the light beam A from the light source 2 is incident on the CCD 9 at a slight angle (see FIG. 2), the light received by the CCD 9 at the design position is received. In the case where it is only necessary to form an image on a part, unless consideration is taken in response to the demand, adjustment will be performed more than necessary, resulting in overspecification and high work cost. Therefore, by disposing the pinhole 13 at a position substantially equal to the image plane distance (focal length) L, the positional deviation of the diffraction pattern K is not a problem, and the pattern as shown in FIG. 3 is observed while observing only its shape. Adjust so that Further, here, the pinhole 13 is arranged at the same position as the CCD 9, but if the relationship of the image plane distance L on the adjusted virtual optical axis E is established, it is folded back at a position different from the position of the CCD 9, for example, a mirror or the like. It may be placed in a different position. Also, the same adjustment can be performed by installing the laser light source 12 on the exit side of the imaging lens.

Next, a fifth embodiment of the present invention will be described with reference to FIGS. 9 and 10 (corresponding to the invention of claim 5). It should be noted that the description of the same parts as those in the above-mentioned respective embodiments is omitted, and the same reference numerals are used for the same parts.

At both ends on the base 10 of the apparatus main body 1,
A pin 20 as a positioning means is provided. The line connecting the centers of these two pins 20 coincides with the adjusted virtual optical axis E. Each of these pins 20 is a pinhole 1
The pin holes 13 and 18 are fixed so that they can be removed. In this fitted state, the line connecting the centers of the small holes 14 and 19 of the pinholes 13 and 18 and the adjusted virtual optical axis E match or substantially match.

Two pins 22 are fixed on the same line as the line connecting the pins 20 near the center of the base 10. These pins 22 are adapted to fit into holes 21 formed in a lens block 23 serving as a lens holding member for holding the imaging lens 8, whereby the X direction and the Yθ direction of the imaging lens 8 are set. Movement is restricted.

The pinholes 13 and 18 are the first adjustment reference points in the optical axis adjustment work, and the centers of the small holes 14 and 19 of the pinholes 13 and 18 are located on the virtual adjustment optical axis E. Need to let. This adjusted virtual optical axis E is a fictitious one in terms of design and adjustment, and is actually invisible, but adjustment cannot be performed unless the reference position is known at the time of adjustment.
Therefore, the line connecting the centers of the small holes 14 and 19 of the pinholes 13 and 18 is treated as the adjusted virtual optical axis E, and the adjusted virtual optical axis E is made visible by passing the laser beam on the line. Therefore, by setting the adjusted virtual optical axis E in a visible state in this way, the reference optical axis for adjustment can be easily set with high accuracy. This makes it possible to improve the accuracy of the optical axis adjustment of the imaging lens 8 and further improve the efficiency of the adjustment work.

Next, a sixth embodiment of the present invention will be described with reference to FIG. 11 (corresponding to the invention of claim 6). It should be noted that description of the same parts as those in each of the above-described embodiments is omitted,
The same reference numerals are used for the same portions.

Adjustment of the imaging lens 8 On the side plates 24a, 24b of the apparatus main body 1 at positions intersecting the virtual optical axis E, small holes 25, 26 are formed as minute openings for restricting the laser light from the laser light source 12. Has been formed.

In such a configuration, the laser light source 12
The laser light from passes through the small hole 25 and travels along the adjusted virtual optical axis E, and passes through the small hole 26 via the imaging lens 8 to form a diffraction pattern K, and the observation plate 15 Projected on. Accordingly, even after the apparatus body 1 is assembled, the optical axis adjustment of the lens optical axis C of the imaging lens 8 and the recheck after the adjustment can be easily performed by simply removing the mirror 7, the CCD 9, and the like. . The side plates 24a and 24b having the small holes 25 and 26 replace the pinholes 13 and 18 having the small holes 14 and 19 described above, and it is possible to dispose the pinholes 13 and 18 on the optical axis. The optical axis of the imaging lens 8 can be adjusted at any time, and thus the workability of assembling and dismounting can be further improved. In addition, the side plates 24a, 2 are used as constituent members of the apparatus main body 1 in which the small holes 25, 26 are formed.
It is not limited to 4b, but may be any component member of the apparatus main body 1 that intersects with the adjusted virtual optical axis E.

Next, a seventh embodiment of the present invention will be described with reference to FIG. 12 (corresponding to the invention of claim 7). It should be noted that description of the same parts as those in each of the above-described embodiments is omitted,
The same reference numerals are used for the same portions.

On the adjustment virtual optical axis E on the exit side of the imaging lens 8 outside the apparatus main body 1, a pinhole 27 as a light flux regulating member is arranged. This pinhole 27
A small hole 28 as a minute opening is formed in this.
A pinhole 18 having a small hole 19 is arranged on the adjusted virtual optical axis E on the incident side of the imaging lens 8 in the apparatus body 1.

Generally, when an optical axis adjusting pinhole is to be installed inside the apparatus main body 1, it takes a long time for the attachment and detachment work, and depending on the structure of the apparatus, it cannot be arranged inside, or even if it can be installed, other The components necessary for the adjustment may not be attached, or the imaging lens 8 may be displaced when it is removed after the optical axis adjustment. Therefore, in such a case, by disposing at least one pinhole 27 outside the apparatus main body 1, it becomes possible to widen the pinhole interval, which enables highly accurate adjustment. , It is possible to deal with the problems as described above. Further, by arranging all the pinholes outside the apparatus main body 1 and further installing a pinhole (not shown) in place of the pinhole 18 outside the apparatus main body 1, more highly accurate adjustment can be performed. it can. Further, this eliminates the need to insert a hand into the inside of the apparatus main body 1 or to attach or remove the pinhole when adjusting the optical axis, thereby improving the work efficiency.

Next, an eighth embodiment of the present invention will be described with reference to FIG. 13 (corresponding to the invention of claim 8). It should be noted that description of the same parts as those in each of the above-described embodiments is omitted,
The same reference numerals are used for the same portions.

A position adjusting mechanism 29 as a wave light optical axis adjusting means is attached to the laser light source 12. In this case, the position adjustment mechanism 29 causes the adjustment virtual optical axis E of the imaging lens 8 and the optical axis D of the laser light of the laser light source 12 passing through the small hole 19 to coincide or substantially coincide with each other.
To move.

Whether or not the laser light source 12 is always in a predetermined position is very important, and if the laser light source 12 is misaligned for some reason, it is necessary to quickly return it to the normal position. Therefore, even if the optical axis D is deviated from the adjusted virtual optical axis E, the position adjusting mechanism 29 can be used to make quick adjustment. Here, the shift (X, Y directions) of the laser light source 12 and the tilt (Xθ, Yθ directions) can be adjusted. Specifically, when the optical axis shift occurs,
Only the imaging lens 8 is removed, and the optical axis is adjusted so that the position and shape of the diffraction pattern K return to the original state. Further, such a position adjusting mechanism 29 matches the optical axis D of the laser light with the adjusted virtual optical axis E on the basis of the pinholes 13 and 18 not only when the optical axis shifts but also in the initial stage of the work. It can be useful in any case. Further, even in such adjustment of the laser optical axis D, the pinhole 13,
By making the interval of 18 as wide as possible, the optical axis can be adjusted with higher accuracy. Further, in the embodiment, since adjustment was not necessary, the Z-axis direction (optical axis direction)
Although the adjusting mechanism is not attached to the above, a position adjusting mechanism 29 may be added if it is necessary to improve workability.

Next, a ninth embodiment of the present invention will be described with reference to FIG. 14 (corresponding to the invention of claim 9). It should be noted that description of the same parts as those in each of the above-described embodiments is omitted,
The same reference numerals are used for the same portions.

A pinhole 27 is arranged outside the apparatus body 1 on the exit side of the imaging lens 8, and a position adjusting mechanism 30 as an opening center position adjusting means is attached to the pinhole 27. . The position adjusting mechanism 30 moves the pinhole 27 so that the adjusted virtual optical axis E of the imaging lens 8 and the center of the small hole 28 of the pinhole 27 coincide or substantially coincide with each other.

The pin holes 13 and 18 provided inside the apparatus main body 1 are, for example, the pins 20 (see FIG. 10) as described above.
The positioning adjustment can be easily performed by using (see). On the other hand, it is difficult to position the pinhole 27 arranged outside the apparatus body 1 without adjustment, and there is a problem in accuracy. Therefore, the position adjusting mechanism 30 can be used to adjust the pinhole 27. Here, since the pinhole 27 is installed so as to be oriented substantially perpendicular to the adjusted virtual optical axis E, only the shift (X and Y directions) can be adjusted. This adjustment adjusts the pinhole 27 so that the reference diffraction pattern K generated when only the pinholes 13 and 18 are arranged and the diffraction pattern K when the pinhole 27 is arranged match. Therefore, in this way, the position adjusting mechanism 3
By adjusting the pinhole 27 by using 0, the adjustment work becomes easy, and highly accurate positioning can be performed easily. Further, although the position adjusting mechanism 30 is adjusted only for the shift, the position (Xθ, Yθ) may be adjusted if necessary. Further, the position adjusting mechanism 30 may adjust not only the outside of the apparatus main body 1 but also the pinholes 13 and 18 installed inside the apparatus main body 1.

Next, a tenth embodiment of the present invention will be described with reference to FIGS. 9 and 10 (corresponding to the invention of claim 10). It should be noted that the description of the same parts as those in the above-mentioned respective embodiments is omitted, and the same reference numerals are used for the same parts.

Pinholes 13, 18 and a lens block 23 as a lens holding member for holding the imaging lens 8 are provided on the same plane of the base 10 (constituent member) fixed to the apparatus main body 1. There is.

Lens block 2 for holding the imaging lens 8
By disposing 3, the pinholes 13 and 18, and the pins 20 and 22 for mounting these members on the same surface of the same member, it is possible to set the processing accuracy and the molding accuracy in the mounting portion to be high. The flatness and the positional accuracy of the mounting portion can be maintained with high accuracy. As in the embodiment, the lens holding member 23 and the pinholes 13 and 18
The method of mounting the same on the same plane of the base 10, which is the same member, is the best in terms of accuracy, but when it is not possible to mount on the same plane of the same member due to the configuration and structure of the device, the same plane Even if it is not above, it is a method of mounting on at least the same member so that the accuracy is not deteriorated.

Next, an eleventh embodiment of the present invention will be described with reference to FIGS. 15 and 16 (corresponding to the invention of claim 11). It should be noted that the description of the same parts as those in the above-mentioned respective embodiments is omitted, and the same reference numerals are used for the same parts.

Lens block 2 for holding the imaging lens 8
A reinforcing channel 31 as a high-rigidity means is attached to the base 10 (constituent member) on which 3 is installed along the central longitudinal direction on the lower surface side of the base 10. The reinforcing channel 31 has a structure sufficient to withstand the weight of the imaging lens 8.

At the stage before the adjustment of the optical axis C of the lens of the imaging lens 8, there is no deflection of the base 10 and the accuracy is maintained to some extent. Due to the added weight, the vicinity of the center of the base 10 is curved in a concave shape. Therefore, by providing the base 10 with the reinforcing channel 31 sufficient to withstand the weight of the imaging lens 8, the surface accuracy of the base 10 can be always kept stable. It is possible to prevent deterioration of axis adjustment accuracy. The high-rigidity means is not limited to the reinforcement means such as the reinforcement channel 31, and any method and method may be used as long as the high-rigidity means can withstand the weight of the imaging lens 8.
Further, as in the embodiment, not only the installation portion of the lens block 23 but also the pinholes 13 and 1 are provided by the reinforcing channel 31.
If the adjustment parts such as 8 and the installation parts such as the main body constituent members such as the mirror 7 and the CCD 9 are also reinforced, not only the optical axis adjustment of the imaging lens 8 becomes more precise, but also the reading optical system. Overall adjustment accuracy is also improved.

Next, a twelfth embodiment of the present invention will be described with reference to FIG. 17 (corresponding to the invention of claim 12). It should be noted that the description of the same parts as those in the above-mentioned respective embodiments is omitted, and the same reference numerals are used for the same parts.

A pinhole 27 is arranged outside the apparatus main body 1 on the exit side of the imaging lens 8, and a position adjusting mechanism 32 as a light flux regulating member movement adjusting means is attached to the pinhole 27. . This position adjusting mechanism 32
The pinhole 27 is moved in the Z-axis direction (adjustment virtual optical axis direction).

The focal length of the imaging lens 8 and the pinhole 2
Depending on the positional relationship with 7, the projected diffraction pattern K may be blurred and difficult to see, and the position and shape may not be clearly determined. In such a case, the focal length of the image forming lens 8 cannot be changed or unnecessarily moved in the optical axis direction. Therefore, a clear diffraction pattern K is created by moving the pinhole 27 arranged on the exit side of the imaging lens 8 in the optical axis direction. Thereby, the accuracy of the optical axis adjustment can be improved.

Further, a mechanism for adjusting the shift (X, Y directions) and the inclination (Xθ, Yθ directions) like the above-mentioned position adjusting mechanism 30 (see FIG. 14) is added to the position adjusting mechanism 32. As a result, the accuracy of the optical axis adjustment can be further improved. Further, the pinhole 3 having a small hole 38 is provided outside the apparatus main body 1 on the incident side of the imaging lens 8.
7 is arranged, and by adding a position adjusting mechanism 39 as an opening center position adjusting means for moving the pinhole 37 in the shift (X, Y directions), the accuracy of the optical axis adjustment is further improved. be able to.
Further, in the embodiment, the laser light source 12 is installed and adjusted on the incident side of the imaging lens 8, but the reverse arrangement, that is,
When the laser light source 12 is installed on the emitting side of the imaging lens 8 for adjustment, a mechanism similar to the position adjusting mechanism 32 may be attached to the pinhole on the incident side.

Next, a thirteenth embodiment of the present invention will be described with reference to FIG. 18 (corresponding to the invention of claim 13). It should be noted that the description of the same parts as those in the above-mentioned respective embodiments is omitted, and the same reference numerals are used for the same parts.

On the optical path behind the pinhole 27, a light receiving monitor 33 (hereinafter referred to as a CCD camera) is arranged as pattern display means. A display 34 for displaying the received diffraction pattern K on the screen and an analysis device 35 for analyzing the state of the diffraction pattern K are connected to the CCD camera 33.

In the observation plate 15 as described above, since the amount of positional deviation (width) of the projected diffraction pattern K is generally measured by applying a scale, adjustment is performed by subjective evaluation, and the adjustment accuracy may be deteriorated. There is. Therefore, by making the CCD camera 33 detect the diffraction pattern K, the pattern state can be adjusted by objective evaluation,
As a result, the reliability of adjustment accuracy can be further improved.

Next, a fourteenth embodiment of the present invention will be described with reference to FIG. 19 (corresponding to the invention of claim 14). It should be noted that the description of the same parts as those in the above-mentioned respective embodiments is omitted, and the same reference numerals are used for the same parts.

A position adjusting mechanism 36 as a projection position movement adjusting means is attached to the observation plate 15. The position adjusting mechanism 36 moves the observation plate 15 in the adjustment virtual optical axis direction.

The size of the projected diffraction pattern K increases as the projected position increases, and decreases when the projected position decreases. Further, if the diffraction pattern K is made too large at the time of adjustment, the pattern will be blurred due to deterioration of the light quantity,
On the contrary, if it is too small, it becomes impossible to judge the difference in pattern state. Considering these points, the observation plate 1 is designed so that the projected diffraction pattern K is optimal in terms of light quantity and size.
5 is moved in the optical axis direction. Specifically, while observing the light quantity and size of the diffraction pattern K, the observation plate 1 is adjusted by the position adjusting mechanism 36 so that the pattern state is suitable for adjustment.
5 is moved in the Z direction. Thereby, the optical axis adjustment accuracy can be improved. In addition to the optical axis direction,
If the shift (X, Y directions) and the inclination (Xθ, Yθ directions) can be adjusted, the projection state of the diffraction pattern K can be further improved. Although the observation plate 15 is moved by the position adjusting mechanism 36 here, the light receiving monitor 33 may be moved in the Z direction instead of the observation plate 15.

Next, a fifteenth embodiment of the present invention will be described with reference to FIG. 17 (corresponding to the invention of claim 15). It should be noted that the description of the same parts as those in the above-mentioned respective embodiments is omitted, and the same reference numerals are used for the same parts.

The diameter of the small hole 28 of the pinhole 27 arranged on the exit side of the imaging lens 8 is made variable by a variable mechanism (not shown) as an opening variable means.

The small hole 28 of the pinhole 27 plays a role of determining the final light amount and size of the diffraction pattern K projected. In this case, the light quantity of the diffraction pattern K is small.
The size of the diffraction pattern K is proportional to the diameter of 8
There is a relationship that is inversely proportional to the diameter of 8. Therefore, while observing the state of the diffraction pattern K projected on the observation plate 15, the diameter of the small hole 28 is changed by using a variable mechanism so that the diffraction pattern K has the optimum light amount and size for the optical axis adjustment. To do. Thereby, the light quantity and size of the diffraction pattern K can be freely and delicately controlled. Further, such a variable mechanism can be attached to the pinhole 37 arranged on the incident side of the imaging lens 8 and the small hole 38 can be changed to further expand the control range. In addition, if the variable mechanism can change not only the size of the small hole diameter but also its shape, more flexible control can be performed, so that the optical axis of the imaging lens 8 is adjusted with an arbitrary diffraction pattern shape that is easy to adjust. be able to.

Next, a sixteenth embodiment of the present invention will be described with reference to FIG. 19 (corresponding to the invention of claim 16). It should be noted that the description of the same parts as those in the above-mentioned respective embodiments is omitted, and the same reference numerals are used for the same parts.

An opening / projection position varying means is provided for varying the size of the small hole 28 of the pinhole 27 and the projection distance from the small hole 28 to the observation plate 15. In this case, as the opening / projection position changing means, for example, the changing mechanism (opening changing means) of the fifteenth embodiment for changing the size of the small hole 28 and the tenth changing means for changing the projection distance. Position adjusting mechanism 36 (projection position movement adjusting means) of the fourth embodiment
And can be combined.

If the variable mechanism or the position adjusting mechanism 36 is used alone for adjustment, it is good for a limited device, but it cannot be adjusted for another imaging lens of another device. In this case, the laser power and the pinholes 27 and 37 are factors that determine the light quantity and size of the diffraction pattern K.
And the projection position of the diffraction pattern K. At least the pinholes of the pinhole and the projection position of the diffraction pattern K are variably adjusted at the same time. Therefore, it is necessary to expand the control range and flexibly respond to any device. Therefore, the diameter of the small hole 28 of the pinhole 27 is changed by using the variable mechanism, and at the same time, the observation plate 15 is moved in the Z direction by using the position adjusting mechanism 36. That is, while observing the state of the diffraction pattern K projected on the observation plate 15, the diameter of the small hole 28 and the position of the observation plate 15 are adjusted simultaneously and in balance. As a result, the control range of the optical axis adjustment can be further expanded, and any apparatus can be flexibly accommodated. Therefore, the optical axis of the imaging lens 8 is always adjusted using the diffraction pattern K in the optimum state. be able to.

Next, a seventeenth embodiment of the present invention will be described with reference to FIG. 20 (corresponding to the invention of claim 17). It should be noted that the description of the same parts as those in the above-mentioned respective embodiments is omitted, and the same reference numerals are used for the same parts.

On the optical axis adjusting table 40, a pin 41 as a positioning means for positioning the base 10 holding the imaging lens 8 is fixed. The base 10 is detachably attached to these pins 41. Base 1
The imaging lens 8 is held on the lens 0 via a lens block 23 (see FIG. 9). Further, on the optical axis adjusting table 40, optical members for adjusting the optical axis, that is, the laser light source 12, the pinholes 27 and 37, the observation plate 1 are provided.
5 etc. are arranged.

When the base 10 moves during the adjustment of the optical axis of the imaging lens 8, or when the optical axes of the same imaging lens 8 must be adjusted in mass production, the optical axes are adjusted one by one. Optical members (laser light source 12 and pinholes 27, 3
(7) is readjusted, it takes too much working time, and the measurement accuracy varies each time. Therefore,
The optical axis adjustment work was performed using the optical axis adjustment table 40. Specifically, first, the optical axis adjustment table 40
An optical member for adjusting the optical axis is arranged on the top. Next, environment setting (position setting of the optical member) for adjusting the lens optical axis C of the imaging lens 8 is performed. After the initial environment setting is completed, the state after the setting is maintained unless the device type is changed. Next, in the state after the setting, the diffraction pattern K
The lens optical axis C of the imaging lens 8 is adjusted by. After completion of the optical axis adjustment, the base 10 positioned on the pin 41 is removed from the table 40. Then, when the readjustment is performed, the same base 10 is used again, and when the mass production is performed, another base 10 is used again.
Are set at predetermined positions by the pins 41 of the table 40, and the lens optical axis of the imaging lens 8 is adjusted. Therefore, from the above, it is not necessary to set the environment for the second and subsequent optical axis adjustments, so that the adjustment work efficiency is remarkably improved and the accuracy variation between the adjustments can be suppressed as much as possible. In the embodiment, the base 10 is positioned with respect to the table 40, but the positioning member with respect to the table 40 is not particularly limited as long as it is a constituent member of the apparatus body 1.
Further, if the pin 41 is used as the positioning means (as an alternative to the pins 20 and 22) according to claim 5, the adjustment accuracy is further improved.

Next, an eighteenth embodiment of the present invention will be described with reference to FIGS. 21 and 22 (corresponding to the invention of claim 18). It should be noted that the description of the same parts as those in the above-mentioned respective embodiments is omitted, and the same reference numerals are used for the same parts.

The present embodiment relates to a method of adjusting the optical axis of the imaging lens 8 using the diffraction pattern K. Hereinafter, a procedure for installing a pinhole inside the apparatus main body 1 to adjust the optical axis will be sequentially described based on the first to third optical axis adjusting steps.
First, the first optical axis adjusting step will be described. As shown in FIG. 21, the pinholes 13 and 18 are positioned and fixed to the base 10. This positioning can be performed by fitting the pin 20 into the holes 21 of the pin holes 13 and 18 (see FIG. 9). These pinholes 13, 1
Due to the positioning of 8, the small holes 14 and 19 coincide with the adjusted virtual optical axis E.

Next, the second optical axis adjusting step will be described. As shown in FIG. 22, the laser light source 12 provided with the position adjusting mechanism 29 and the observation plate 15 are arranged at the front and rear positions separated from the pinholes 13 and 18. In this state,
The laser light from the laser light source 12 is applied to the pinholes 18, 13
The light is emitted toward the small holes 19 and 14, and the diffraction pattern K generated thereby is projected on the observation plate 15. Then, it is checked whether or not the projected diffraction pattern K is a beautiful diffraction pattern K (see FIG. 3) having a concentric circular uniform light amount distribution. If the diffraction pattern K is a clean concentric circle, the optical axis adjustment is not necessary. If not, the optical axis D of the laser light is adjusted. To adjust the optical axis, the laser light source 12 is shifted (X, Y directions) and tilted (Xθ, Y) using the position adjusting mechanism 29 while looking at the diffraction pattern K on the observation plate 15.
(θ direction). By performing such an adjustment, the optical axis D of the laser light is made to coincide with the line connecting the centers of the small holes 14 and 19, whereby the adjusted virtual optical axis E is actually visible. The process up to this point completes the creation of an environment for adjusting the lens optical axis C of the imaging lens 8.

Next, the third optical axis adjusting step will be described. Here, the lens optical axis C of the imaging lens 8 is adjusted. First, the imaging lens 8 is attached at a predetermined position between the pinholes 13 and 18. This attachment can be performed by fitting the lens block 23 holding the imaging lens 8 with the pin 22 (see FIG. 9). Then, the diffraction pattern K obtained by irradiating the laser light from the laser light source 12 with the imaging lens 8 interposed is projected onto the observation plate 15, and the projected diffraction pattern K causes the imaging lens 8 to be interposed. It is checked whether it is the same as the beautiful concentric diffraction pattern K before. If the pattern is the same, the adjustment is not performed. If not, the lens optical axis C is adjusted. This adjustment is performed while observing the diffraction pattern K so that the diffraction pattern K coincides with the pattern state before interposing the imaging lens 8 (however, in consideration of the case where the light amount and the diameter change), not shown. This is executed by adjusting the image forming lens 8 in the shift (X, Y) and tilt (Xθ, Yθ) directions using the image lens optical axis adjusting means (first embodiment). In this case, if the laser light passes through the centers of the two small holes 14 and 19, it is always projected at the same position to form a beautiful pattern. Therefore, the lens optical axis C is adjusted by adjusting the projected diffraction pattern K. It suffices to make adjustments by paying attention to only the shape. After this adjustment is completed, the imaging lens 8 is fixed so as not to move except in the Z direction (optical axis direction). This allows
The lens optical axis C of the imaging lens 8 coincides with the adjusted virtual optical axis E, and the optical axis adjustment work is completed. Then, by removing the pinholes 13 and 18 from the base 10,
The next step, for example, attachment of actual optical members such as the mirror 7 and the CCD 9 to the apparatus main body 1 can be performed. By performing the optical axis adjustment according to the procedure of the first to third optical axis adjusting steps as described above, the highly accurate adjustment work can be smoothly and efficiently performed.

Next, a nineteenth embodiment of the present invention will be described with reference to FIGS.
Description will be given based on FIG. 26 (corresponding to the invention of claim 19). It should be noted that the description of the same parts as those in the above-mentioned respective embodiments is omitted, and the same reference numerals are used for the same parts.

The present embodiment relates to a method of adjusting the optical axis of the imaging lens 8 using the diffraction pattern K. Hereinafter, the procedure for installing the pinholes inside and outside the apparatus body 1 to adjust the optical axis will be sequentially described based on the first to fourth optical axis adjusting steps. First, the first and second optical axis adjusting steps are work steps when the pinholes 13 and 18 are arranged inside the apparatus main body 1, and the first and second optical axis adjusting steps of the eighteenth embodiment described above. Since the work content is the same as that of the optical axis adjusting step, description thereof is omitted here.

Next, the third optical axis adjusting step will be described. Here, the pinholes 27 and 37 are different from the place where the pinholes 13 and 18 are arranged, for example,
It is a step of arranging it outside the apparatus main body 1 for adjustment.
That is, first, as shown in FIG. 23, the position adjusting mechanism 3
The pinhole 37 provided with 9 is arranged at a predetermined position between the laser light source 12 and the pinhole 18 outside the apparatus main body 1. In general, when installing and adjusting the pinholes both inside and outside the apparatus body 1, it is always necessary to provide a reference light and one or more reference pinholes. Therefore, here, the pinholes 13 and 18 are installed as they are. Further, in order to eliminate the decrease in the amount of light, when either one of the pinholes is removed, the pinhole 18 closer to the pinhole 37 is removed. Then, with the pinhole 37 arranged in this manner, the laser light from the laser light source 12 is applied to the pinhole 37,
It irradiates 18 and 13, and the diffraction pattern K is projected on the observation plate 15. It is judged whether or not the projected diffraction pattern K coincides with the beautiful concentric circular diffraction pattern K, and if they do not coincide, the adjustment is performed. This adjustment is
This is performed by moving the pinhole 37 in the shift (X, Y) direction using the position adjusting mechanism 39 while observing the diffraction pattern to adjust the position of the small hole 38, and then fixing after this adjustment. As a result, the small hole 38 of the pinhole 37
The center of is coincident with the optical axis D of the laser light, that is, the adjusted virtual optical axis E.

Next, as shown in FIG. 24, the pinhole 27 having the position adjusting mechanism 30 is arranged at a predetermined position between the pinhole 13 outside the apparatus main body 1 and the observation plate 15. The position of the pinhole 27 is adjusted by using the position adjusting mechanism 30.
This can be performed in the same manner as in the above case, and finally the center of the small hole 28 of the pinhole 27 coincides with the adjusted virtual optical axis E. Through the series of adjustments described above, the small holes 14, 19, 28, 3 of the four pinholes 13, 18, 27, 37 are formed.
The center of 8 can be aligned with the adjusted virtual optical axis E. After that, as shown in FIG. 25, only the pinholes 27 and 37 arranged outside the apparatus body 1 are left, and both the pinholes 13 and 18 inside the apparatus body 1 are removed.
However, either one of the pinholes 13 and 18 may be removed or left as it is, as required. The process up to this point completes the creation of an environment for adjusting the lens optical axis C of the imaging lens 8.

Next, the fourth optical axis adjusting step will be described. Here, as shown in FIG. 26, the imaging lens 8 is attached at a predetermined position and the lens optical axis C is adjusted. The details of this work are the same as those of the third optical axis adjusting step of the nineteenth embodiment described above, and therefore the description thereof is omitted here. When the optical axis adjustment is completed, the optical axis C is fixed so as not to move except in the optical axis direction, and the adjustment work of the lens optical axis C of the imaging lens 8 is completed. In this case, since the pinholes 27 and 37 are arranged outside the apparatus main body 1, the pinhole interval can be widened, whereby the optical axis adjustment accuracy can be set to be considerably high. As described above, not only the pinholes 13 and 18 are arranged only inside the apparatus, but the pinholes 27 and 37 are arranged outside the apparatus, and the optical axis adjustment is performed according to the procedure of the first to fourth optical axis adjusting steps. By doing so, highly accurate adjustment work can be performed more smoothly and efficiently.

Next, a twentieth embodiment of the present invention will be described (corresponding to the invention of claim 20). It should be noted that the description of the same parts as those in the above-mentioned respective embodiments is omitted, and the same reference numerals are used for the same parts.

This embodiment relates to a method for adjusting the optical axis of the imaging lens 8, and relates to the various optical axis adjusting steps described above (claim 18,
In addition to the invention described in claim 19, a main body assembling step is newly added. The main body assembling step means assembling at least the minimum number of members required for the optical axis adjustment inside the apparatus main body 1 before the optical axis adjustment is performed in the optical axis adjusting step.

The specific operation of the main body assembling process will be described below. First, at a stage before entering the optical axis adjusting step, at least the imaging lens 8 and the pinholes 13 and 18 required for the optical axis adjusting work are assembled on the base 10. After performing this necessary minimum assembly, in the optical axis adjustment process, create an environment for optical axis adjustment using the diffraction pattern,
Further, the lens optical axis C of the imaging lens 8 is adjusted. After completion of the optical axis adjustment, the imaging lens 8 and the pinholes 13 and 18
All the remaining members other than the above are assembled to the apparatus main body 1. By the above, a series of steps of the main body assembling step and the optical axis adjusting step are completed.

In general, the optical axis adjustment of the imaging lens 8 is often performed after the members such as the optical system, the electric transmission system, and the mechanical system in the apparatus are assembled and the state is almost completed. If the optical axis adjustment is performed after setting the optical axis to a state close to the above condition, the laser beam that is the reference for the adjustment may be blocked by these members, or there may be no space for installing the pinhole in the apparatus body 1. Therefore, at the stage of designing the device, the structure of the device main body 1 is made a structure in consideration of the optical axis adjustment and the assembly procedure of each member, and as described above, it does not interfere with the adjustment of the lens optical axis C. The minimum necessary components (imaging lens 8, pinholes 13 and 18)
Etc.) is assembled to the apparatus body 1 and the optical axis is adjusted, and after the adjustment is completed, all the other members are assembled to the apparatus body 1, so that the adjustment work can be performed more smoothly. As a result, work efficiency can be further improved.

The twenty-first embodiment of the present invention will now be described (corresponding to the invention of claim 21). In addition,
The description of the same parts as those of the above-described embodiments will be omitted, and the same reference numerals will be used for the same parts.

This embodiment relates to a method for adjusting the optical axis of the imaging lens 8, and relates to the various optical axis adjusting steps described above (claim 18,
In addition to the invention described in claim 19, a main body assembling step is newly added. This main body assembling step means at least the imaging lens 8 and the CCD among the components of the main body 1 of the apparatus.
9 and the mirror 7 as a member for blocking the light flux of the laser light source 12 are made detachable, and almost all the constituent members except these detachable members are light-transmitted by the imaging lens 8 by the optical axis adjusting process. Assembling inside the apparatus main body 1 before the axis adjustment.

The specific operation of the main body assembling process will be described below. First, before entering the optical axis adjusting step, as shown in FIG. 1, almost all the constituent members other than the detachable mirror 7, the imaging lens 8 and the CCD 9 are assembled inside the apparatus main body 1. . However, these first assembled members are the ones through which the laser light passes, the pinholes 13 and 18,
It has a shape and structure that does not hinder the attachment and detachment of the mirror 7, the imaging lens 8, the CCD 9, and the like. After assembling almost all the members, in the optical axis adjustment process, the pinhole 1
3, 18, the imaging lens 8 is installed inside the apparatus main body 1,
An environment for adjusting the optical axis is created using the diffraction pattern, and then the lens optical axis C of the imaging lens 8 is adjusted.
After completion of the optical axis adjustment, the pinholes 13 and 18 are removed, and the mirror 7 and the CCD 9 are assembled to the apparatus main body 1 to complete a series of steps.

In general, the optical axis of the imaging lens 8 is adjusted in such a manner that the lens optical axis C is first adjusted and then the apparatus main body 1 is assembled in earnest. Even if the adjustment is performed, the device main body 1 after adjustment is subjected to external force at the time of assembling, optical members, own weight of parts, etc., which causes distortion, and the optical axis shifts when the device main body 1 after assembly is actually used. May occur. Therefore, as described above, the optical axis adjustment of the lens optical axis C is performed by assembling the apparatus main body 1 to the actual use level or in a state close to the actual use level to bring out any badness such as distortion generated in the apparatus main body 1. Therefore, the lens optical axis C of the imaging lens 8 can be substantially positioned with higher accuracy. Further, the detachable member is not only the mirror 7 as a member for blocking the light flux of the imaging lens 8, the CCD 9 and the laser light source 12 as in the embodiment, but also a member that interferes with the operator when adjusting the optical axis. If the attachment / detachment is possible (however, the attachment / detachment of a member that does not affect the deterioration such as distortion), the adjustment work efficiency is further improved.

Next, a twenty-second embodiment of the present invention will be described (corresponding to the invention of claim 22). In addition,
The description of the same parts as those of the above-described embodiments will be omitted, and the same reference numerals will be used for the same parts.

This example relates to the optical axis adjusting method of the imaging lens 8 described in the twenty-first example. Among the constituent members of the apparatus main body 1, an opening is formed in a member that shields the laser light from the laser light source 12 at the time of adjusting the optical axis. Here, the laser light is passed through the opening to allow the optical axis to pass. I made adjustments. For example, in this case, the member that blocks light is the side plates 24a and 24b (see FIG. 1).
1) and the mirror 7 (see FIG. 1), and the opening means the small holes 25, 26 (see FIG. 11) of the side plates 24a, 24b.
It corresponds to a hole (not shown) of about 3 to 5 mm formed at the position (see). This opening has a small diameter that allows the laser light to pass therethrough. In this case, in order to provide an opening in a member that blocks the laser light so as not to block the laser light, the diameter should be limited to the minimum size that does not affect other members. The size of this diameter may be about 3 to 5 mm as described above.

Generally, in order to make the shape such that the passage of the laser light from the laser light source 12 is not obstructed, a relief part or a large hole is provided in the member in the passing optical path, or a part of the constituent members is omitted. Doing so may cause a decrease in adjustment accuracy, a decrease in rigidity of the apparatus body 1, a decrease in apparatus function, and the like. Therefore, the optical axis of the imaging lens 8 is adjusted by forming the opening of the minimum size that allows the laser light to pass through the member that shields light so that the apparatus body 1 is actually used. You can In addition, this can prevent deterioration of adjustment accuracy, rigidity, function, and the like.

In all the embodiments described above, the light flux regulating member (pinholes 13, 16, 18, 2) is used.
(7,37) the small openings to the small holes 14,17,19,2
However, the shape is not limited to this circular shape, and may be, for example, a vertically long or horizontally long slit or a rectangular shape. Further, the optical axis adjusting method is a method in which all the adjustment virtual optical axes E of the imaging lens 8 are strictly matched, but the ratio of the matching accuracy is determined by the performance and specifications of the apparatus itself. Therefore, it is not always necessary to set it strictly. In addition, the arrangement position of the optical member for adjusting the optical axis is set to a position (imaging lens 8
The same adjustment can be carried out even if they are installed at positions (opposite to the positions on the incident side and the exit side). Furthermore, the method of adjusting the lens optical axis C of the imaging lens 8 using the diffraction pattern K is not limited to the document reading device, but can be applied to a high-quality and highly accurate device including the imaging lens 8. .

[0130]

According to the first aspect of the invention, the wave light illuminating means and the light flux regulating member having a minute aperture for regulating the light flux are arranged on the adjusted virtual optical axis of the imaging lens, and the diffraction generated by this is arranged. The pattern display means receives and displays the pattern, and the imaging lens optical axis adjusting means moves and adjusts the lens optical axis of the imaging lens based on the displayed diffraction pattern to adjust the imaging lens. Since the diffraction pattern when it is interposed on the optical axis and the diffraction pattern when it is not interposed are made to coincide with each other, the lens optical axis of the imaging lens can be made to coincide with the adjusted virtual optical axis, that is, the design position. This prevents the optical axis of the reading light beam from being obliquely incident on the lens optical axis of the imaging lens during actual document reading, thus causing optical axis misalignment. Image quality can be the increase further, it is possible to provide a high-quality document reading apparatus.

According to a second aspect of the present invention, at least two light flux regulating members are arranged on the adjusted virtual optical axis on the side opposite to the wave light illuminating means arranged on either side of the entrance and exit of the imaging lens. Since the optical axis of the imaging lens is adjusted by using the diffraction pattern, whether the shapes of the diffraction patterns match without considering the amount of deviation from the reference position of the pattern display means on which the diffraction pattern is projected. The lens optical axis can be adjusted by determining whether or not it is possible to further improve the accuracy of the optical axis adjustment of the imaging lens.

According to the third aspect of the present invention, the light flux regulating member is arranged on the adjustment virtual optical axis on the same side as the wave light illuminating means arranged on either side of the entrance and exit of the imaging lens, and the diffraction pattern is used. Since the optical axis of the imaging lens is adjusted, it is possible to always check the position of the wave light illuminating means, which serves as a reference for the optical axis adjustment, and thus the optical axis of the imaging lens can be adjusted with high accuracy. It can be performed stably without variation.

According to a fourth aspect of the present invention, at least 1 is provided at a position substantially equal to the image plane position of the imaging lens or the image plane distance thereof.
Since the two light flux regulating members are arranged to adjust the optical axis of the imaging lens, it is possible to perform the adjustment suitable for the device that allows the slight deviation of the optical axis of the imaging lens. No adjustment is required, which makes it possible to provide optimum quality performance for individual devices at optimum cost.

According to the fifth aspect of the present invention, the line connecting the centers of the minute apertures formed by at least two light flux regulating members is made to coincide or substantially coincide with the adjusted virtual optical axis of the imaging lens by using the positioning means. As a result, the adjusted virtual optical axis, which is the reference for the optical axis adjustment, can be set easily and with high accuracy, and can be made visible in reality. It is possible to improve accuracy and work efficiency of positioning adjustment.

According to the sixth aspect of the present invention, since the minute opening for generating the diffraction pattern is formed in the apparatus main body to adjust the optical axis of the imaging lens, the light flux regulating member should be installed inside the main body. Without adjusting the optical axis, the optical axis of the imaging lens can be easily adjusted and the optical axis can be checked after adjustment. This makes it possible to improve the work efficiency of the optical axis adjustment, and maintainability and reliability of the device. It is possible to improve the sex.

According to the seventh aspect of the invention, since the light flux regulating member is arranged outside the main body of the apparatus to adjust the optical axis of the imaging lens, compared with the case where the light flux regulating member is assembled inside the main body of the apparatus. Work efficiency can be significantly improved, and the installation interval can be widened even when a plurality of light flux regulating members are arranged, so that the optical axis of the imaging lens can be adjusted with higher accuracy. Can be done.

According to the present invention, the wave light optical axis adjusting means is used so that the optical axis of the light beam emitted from the wave light illuminating means coincides or substantially coincides with the adjusted virtual optical axis of the imaging lens. Since the optical axis of the luminous flux of the light illuminating means is adjusted, it is possible to quickly and highly accurately respond to the position setting of the wave light illuminating means or when the wave light illuminating means is displaced from the set position. It is possible to further improve the precision of the optical axis adjustment and the work efficiency.

According to a ninth aspect of the invention, the center position of the minute opening is adjusted by using the opening center position adjusting means so that the center position of the minute opening coincides with or substantially coincides with the adjustment virtual optical axis of the imaging lens. Since it is adjusted, the center position can be easily adjusted and high-accuracy positioning can be performed easily.
As a result, it is possible to further improve the accuracy of the optical axis adjustment of the imaging lens and the efficiency of the work.

According to a tenth aspect of the present invention, at least a light flux regulating member and a lens holding member for holding the imaging lens are provided.
Since they are arranged on at least the same constituent member such as the base of the apparatus main body, it is possible to improve the processing accuracy and the molding accuracy of the mounting portion. The position can be maintained with high accuracy.

According to the eleventh aspect of the invention, high rigidity means is applied to the installation portion and its peripheral portion of the component member (base or the like) on which the lens holding member for holding the imaging lens is installed. It is possible to prevent the component members (base, etc.) from being deflected by the weight of the lens or the like, and thus it is possible to constantly maintain the accuracy of the optical axis adjustment before and after the assembly of the imaging lens to the component members.

According to the twelfth aspect of the present invention, the light flux regulating member movement adjusting means is used to arrange on the adjusting virtual optical axis on the side opposite to the wave light illuminating means arranged on either side of the entrance and exit of the imaging lens. Since the provided light flux regulating member is moved and adjusted in the adjustment virtual optical axis direction, it is possible to eliminate blurring of the projected diffraction pattern and to clearly determine the pattern state. It is possible to further improve the accuracy of axis adjustment.

According to the thirteenth aspect of the invention, since the light receiving monitor is used as the pattern display means for receiving and displaying the diffraction pattern, the optical axis of the imaging lens can be adjusted by objective evaluation. The accuracy of the optical axis adjustment of the imaging lens can be improved and the work efficiency can be improved.

According to the fourteenth aspect of the invention, since the pattern display means is moved and adjusted in the adjustment virtual optical axis direction by using the projection position movement adjusting means, the projected diffraction pattern is optimal for both the light quantity and the size. The optical axis of the imaging lens can be adjusted with high accuracy.

According to the fifteenth aspect of the present invention, since at least the size of the minute aperture of the light flux regulating member is varied by the aperture varying means, the light quantity and size of the diffraction pattern are delicately controlled and projected. The diffraction pattern can be set to an optimum state, and thus the accuracy of the optical axis adjustment of the imaging lens can be further improved.

According to the sixteenth aspect of the invention, at least the size of the minute opening of the light flux regulating member and the projection distance from the minute opening to the pattern display means are changed by the opening / projection position changing means. Therefore, it is possible to flexibly respond to the lens of any device by expanding the control range of the light amount and size of the diffraction pattern,
This makes it possible to adjust the optical axis of the imaging lens while always keeping the projected diffraction pattern in an optimum state.

According to a seventeenth aspect of the present invention, at least the wave light illuminating means for adjusting the optical axis of the imaging lens on the optical axis adjusting table, and the component member (base) of the apparatus main body holding the imaging lens. And the like) are arranged so that after the first optical axis adjustment, after the second time, the constituent members are fixed to the positioning means and the movement of the imaging lens is simply adjusted. The accuracy variation between adjustments can be greatly suppressed, which greatly improves the adjustment work efficiency when the optical axis of the same imaging lens is adjusted many times during mass production or readjustment. Can be made.

According to the eighteenth aspect of the present invention, the optical axis adjustment of the imaging lens using the diffraction patterns is sequentially performed according to the first to third optical axis adjustment steps in a state where the light flux regulating member is arranged inside the apparatus main body. Since the optical axis adjustment work is performed smoothly and efficiently, anyone can easily achieve the desired optical axis accuracy, which makes the operation of the imaging lens easy and highly accurate. An optical axis adjusting method can be realized.

According to a nineteenth aspect of the present invention, the first to fourth light flux regulating members are arranged inside the apparatus body, and the second light flux regulating member is arranged inside or outside the apparatus body. Since the optical axis of the imaging lens is adjusted sequentially using the diffraction pattern according to the optical axis adjustment process, the optical axis adjustment work can be performed smoothly and efficiently, and anyone can easily achieve the desired optical axis accuracy. As a result, it is possible to realize a method of adjusting the optical axis of the imaging lens that is easy and highly accurate.

According to the twentieth aspect of the invention, first, at least the minimum number of members necessary for adjusting the optical axis of the imaging lens is assembled according to the main body assembling step, and then the imaging is performed according to the optical axis adjusting step. After adjusting the optical axis of the lens, all the remaining constituent members are assembled inside the main body of the apparatus, so that the optical axis adjustment work can be performed smoothly and the work efficiency can be further improved.

According to a twenty-first aspect of the invention, in the main body assembling step before the optical axis adjusting step for adjusting the optical axis of the image forming lens, at least the image forming lens and the light receiving means among the constituent members of the apparatus main body. Since almost all the constituent members except the member that shields the luminous flux of the wave light illuminating means during the optical axis adjustment are assembled inside the apparatus main body, in the optical axis adjusting step after the assembly, the imaging lens At the stage of adjusting the optical axis, the weight of the device body can be set to the actual usage level or a state close to it, so that the adjustment can be performed in a state where all the badness such as distortion generated in the device body is brought out. Therefore, the substantial positioning of the optical axis of the imaging lens can be performed with higher accuracy.

According to a twenty-second aspect of the present invention, among the constituent members of the apparatus main body, an opening is formed in a member that shields the light beam from the wave light illumination means at the time of adjusting the optical axis, and the wave light illumination is provided in this opening. Since the light flux of the means is guided, it is possible to adjust the optical axis of the imaging lens with high accuracy while the apparatus body is brought close to the state of actual use, and this reduces the rigidity of the apparatus body. It is possible to eliminate the deterioration of the optical axis adjustment accuracy.

[Brief description of drawings]

FIG. 1 is an optical path diagram showing an optical system for adjusting an optical axis of an imaging lens which is a first embodiment.

FIG. 2 is a front view showing the configuration of a reading optical system of the document reading device.

FIG. 3 is a schematic diagram showing a shape of a normal concentric diffraction pattern.

FIG. 4 is a schematic diagram showing the shape of an asymmetric diffraction pattern.

FIG. 5 is an optical path diagram showing a second embodiment.

FIG. 6 is an optical path diagram showing a third embodiment.

FIG. 7 is an optical path diagram showing another configuration example of the third embodiment.

FIG. 8 is an optical path diagram showing a fourth embodiment.

FIG. 9 is an optical path diagram showing a fifth embodiment and a tenth embodiment.

FIG. 10 is a plan view showing a shape on a base surface.

FIG. 11 is an optical path diagram showing a sixth embodiment.

FIG. 12 is an optical path diagram showing a seventh embodiment.

FIG. 13 is an optical path diagram showing an eighth embodiment.

FIG. 14 is an optical path diagram showing a ninth embodiment.

FIG. 15 is an optical path diagram showing an eleventh embodiment.

FIG. 16 is a plan view showing a shape on a base surface.

FIG. 17 is an optical path diagram showing a twelfth embodiment and a fifteenth embodiment.

FIG. 18 is an optical path diagram showing a thirteenth embodiment.

FIG. 19 is an optical path diagram showing a fourteenth embodiment and a sixteenth embodiment.

FIG. 20 is an optical path diagram showing a seventeenth embodiment.

FIG. 21 is an optical path diagram showing a method of adjusting the optical axis of the imaging lens of the eighteenth embodiment.

22 is an optical path diagram showing the optical axis adjusting method following FIG.

FIG. 23 is an optical path diagram showing a method of adjusting the optical axis of the imaging lens of the nineteenth embodiment.

FIG. 24 is an optical path diagram showing the optical axis adjusting method following FIG. 23.

25 is an optical path diagram showing the optical axis adjusting method following FIG.

26 is an optical path diagram showing the optical axis adjusting method following FIG. 25. FIG.

[Explanation of symbols]

 2 Illuminating means 4 Original document 7 Mirror 8 Imaging lens 9 Light receiving means 10 Base 12 Wave light illuminating means 13 Light flux regulating member 14 Micro aperture 15 Pattern display means 16, 18 Luminous flux regulating member 20 Positioning means 25, 26 Micro aperture 27 Luminous flux Regulation member 29 Wave light optical axis adjusting means 30 Opening center position adjusting means 31 High rigidity means 32 Luminous flux regulating member movement adjusting means 33 Light receiving monitor 36 Projection position movement adjusting means 39 Opening center position adjusting means 40 Table 41 Positioning means A Luminous flux B optical axis K diffraction pattern E adjustment virtual optical axis

Claims (22)

[Claims] 1. A document is illuminated by an illuminating means, a light flux containing read information of the document is guided to an imaging lens by this illumination, and the light flux imaged by the imaging lens is focused on a light receiving means. In the document reading device for reading the read information of the document, a wave light illuminating means for emitting wave light is disposed on the adjusted virtual optical axis of either the entrance side or the exit side of the image forming lens, and the image forming lens of the image forming lens is provided. A light flux restricting member having a minute opening for restricting the wave light emitted from the wave light illumination means is disposed on the adjusted virtual optical axis on the side opposite to the wave light illumination means for entrance and exit. A pattern display means for receiving and displaying a diffraction pattern generated by the regulating member is provided, and an imaging lens optical axis adjusting means for supporting the imaging lens so that the lens optical axis thereof is adjustable is provided. To Document reader. 2. At least two light flux regulating members are arranged on an adjusted virtual optical axis on the side opposite to the wave light illuminating means arranged on either side of the entrance and exit of the imaging lens. The document reading apparatus according to claim 1, wherein 3. The light flux regulating member is arranged on the adjusted virtual optical axis on the same side as the wave light illuminating means arranged on either side of the entrance and exit of the imaging lens. Or 2
The document reading device described. 4. The document reading apparatus according to claim 1, wherein at least one light flux regulating member is arranged at a position substantially equal to an image plane position of the imaging lens or a position substantially equal to an image plane distance thereof. apparatus. 5. A positioning means for attaching or substantially aligning a line connecting the centers of the respective minute apertures formed by at least two light flux regulating members with the adjusted virtual optical axis of the imaging lens is attached to the apparatus main body. The document reading device according to claim 1, 2, 3, or 4. 6. A fine aperture for restricting a light flux from the wave light illuminating means is formed in the apparatus main body at a position intersecting with the adjusted virtual optical axis of the imaging lens.
The document reading device described in 3 or 4. 7. The document according to claim 1, wherein at least one light flux regulating member is arranged at a position on the adjusted virtual optical axis of the imaging lens and outside the apparatus main body. Reader. 8. The optical axis of the luminous flux of the wave light illumination means so that the adjusted virtual optical axis of the imaging lens and the optical axis of the luminous flux of the wave light illumination means passing through the minute opening coincide or substantially coincide with each other. 8. The document reading apparatus according to claim 1, further comprising: a wave light optical axis adjusting means for adjusting. 9. An opening center position adjusting means for adjusting the center position of the minute opening is provided so that the adjustment virtual optical axis of the imaging lens and the center position of the minute opening coincide or substantially coincide with each other. Claims 1, 2, 3, 4, 5, characterized in that
The document reading device according to 6, 7, or 8. 10. The at least light flux regulating member and the lens holding member for holding the imaging lens are arranged on at least the same constituent member of the apparatus main body.
The document reading device described in 2, 3, 4, 5, 6, 7, 8 or 9. 11. A high-rigidity means is provided at the installation portion and the peripheral portion of the constituent member of the apparatus main body in which the lens holding member for holding the imaging lens is installed. The document reading device according to 3, 4, 5, 6, 7, 8, 9, or 10. 12. A light flux regulating member arranged on an adjusted virtual optical axis on the side opposite to the wave light illumination means arranged on one side of the entrance and exit of the imaging lens is moved in the adjusted virtual optical axis direction. 12. The document reading apparatus according to claim 1, further comprising a light flux regulating member movement adjusting means for controlling the movement. 13. A light receiving monitor is used as a pattern display means for receiving and displaying a diffraction pattern, and the light receiving monitor is used as a pattern display means.
11. The document reading device according to item 11 or 12. 14. A projection position movement adjusting means for adjusting the projection position by moving the pattern display means in the adjustment virtual optical axis direction.
The document reading device according to 6, 7, 8, 9, 10, 11, 12 or 13. 15. An aperture varying means for varying the size of at least the minute aperture of the light flux regulating member is provided. , 1
The document reading device according to 0, 11, 12, 13 or 14. 16. An aperture / projection position varying means for varying at least the size of the minute opening of the light flux regulating member and the projection distance from the minute opening to the pattern display means. 1, 2, 3, 4, 5, 6,
The document reading device according to 7, 8, 9, 10, 11, 12, 13, 14 or 15. 17. The optical axis adjusting table is so constructed that at least the wave light illuminating means and the optical axis of the light flux of the wave light illuminating means and the adjusted virtual optical axis of the imaging lens are matched or substantially matched. 4. Positioning means for positioning the constituent member of the apparatus main body holding the image lens is provided, and the constituent member is attachable to and detachable from the optical axis adjusting table. , 4,5,6,7,8,9,1
The document reading device according to 1, 12, 13, 14, 15 or 16. 18. The light flux regulating member is positioned inside the apparatus main body such that the adjusted virtual optical axis of the imaging lens and the center of the fine aperture of the light flux regulating member having the minute aperture coincide or substantially coincide with each other. The position of the wave light illumination means is adjusted by using a diffraction pattern so that the first optical axis adjusting step and the optical axis of the wave light illumination means for emitting the wave light coincide with or substantially coincide with the center of the minute opening. Comparing the second optical axis adjusting step of adjusting and positioning with the diffraction pattern before the interposition of the imaging lens with the imaging lens arranged on the adjusted virtual optical axis and after the interposition. And a third optical axis adjusting step of adjusting the optical axis of the imaging lens so that the two diffraction patterns are matched or substantially matched with each other. 19. The first light flux regulating member is adjusted so that the adjusted virtual optical axis of the imaging lens and the center of the minute light flux regulating member having the minute aperture coincide with or substantially coincide with each other. In order that the first optical axis adjusting step of positioning inside the apparatus main body and the center of the minute opening of the first light flux regulating member and the optical axis of the wave light illuminating means that emits wave light may coincide or substantially coincide with each other. A second optical axis adjusting step of adjusting and positioning the position of the wave light illuminating means by using a diffraction pattern, and an adjustment virtual optical axis different from the position where the first light flux regulating member is provided. A second light flux regulating member is disposed inside or outside the device body, and the center of the minute opening of the second light flux regulating member and the optical axis of the light flux of the wave light illuminating means coincide or are substantially the same. Adjust the position of the second light flux regulating member so that they match. The third optical axis adjusting step of positioning by positioning the image forming lens is arranged on the adjusted virtual optical axis, and the diffraction pattern before the interposing of the image forming lens and the diffraction pattern after the interposing are compared. A fourth optical axis adjusting step of adjusting the optical axis of the imaging lens so that the two diffraction patterns are matched or substantially matched with each other. 20. A main body assembling step is provided for assembling at least a minimum number of members required for the optical axis adjustment inside the apparatus main body before performing the optical axis adjustment in the optical axis adjusting step. The optical axis adjusting method for an imaging lens according to claim 18 or 19. 21. Among the constituent members of the apparatus main body, at least the imaging lens, the light receiving means, and the member that blocks the light flux of the wave light illuminating means at the time of adjusting the optical axis are detachable, and these detachable members. 20. The optical system according to claim 18, further comprising a main body assembling step of assembling the components other than the above into the inside of the main body of the apparatus before the optical axis is adjusted by the optical axis adjusting step. Axis adjustment method. 22. Among the constituent members of the apparatus main body, an opening is formed in a member that shields the light flux from the wave light illumination means at the time of adjusting the optical axis, and the light flux is passed through this opening to adjust the optical axis. 22. The method of adjusting an optical axis of an imaging lens according to claim 21, wherein