JPH1097011A - Image scanning device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To facilitate optical axis adjustment of a reflected light image of a document image on a document table. SOLUTION: After an adjustment plate pressing member 42 is engaged with an upper side of an optical axis adjustment plate 33 for fixing and holding an optical mirror 27,
The upper and lower long holes 39 and 41 are fitted into the adjustment plate support projections 37,
By tightening the screw 38 over the central elongated hole 40 and the screw hole, the optical axis adjusting plate 33 is pressed downward by the adjusting plate pressing member 42 and can be displaced vertically by the eccentric screw 43. 32, eccentric screw 4
3, the optical axis L reaching the photoelectric conversion element 19
The original reading unit is mounted in parallel with the optical axis L, the photoelectric conversion element is mounted so as to be rotatable around a rotation fulcrum, and the displacement adjustment screw is operated to operate the photoelectric conversion element. In the direction of rotation with respect to the optical axis L.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanner used as an image input section of a computer or an image scanning apparatus constituting a scanner section of an image forming machine such as a facsimile or an electrophotographic copying machine. The present invention relates to an improvement in a mechanical configuration for adjusting a deviation of an optical axis of a reflected light image of a document image in an optical system.

[0002]

2. Description of the Related Art For example, a digital image forming machine guides a reflected light image obtained by scanning a document image to a photoelectric conversion element,
Here, after being converted into a digital electric signal, required signal processing is performed, and a copy image of a document is formed based on the document image data obtained thereby. The image scanning apparatus includes a scanning optical system disposed between a document placing portion on which a document is set and a photoelectric conversion element, and a supporting structure and a driving structure for the scanning optical system.

FIG. 15 shows an example of a digital image forming machine having a scanner section comprising a conventional image scanning apparatus. In this figure, a document table 102 as a document placing portion is provided on a main body shell 101 constituting a main body shell of the apparatus main body.
Is provided. Further, the scanner unit B, the optical scanner unit 103, the image processing unit 10
4, an image forming unit 105, a fixing unit 106, a paper feeding unit 107, and the like, which are indicated by oblique lines. The scanner section B is configured by first and second exposure scanning optical units 108 and 109 constituting a scanning optical system for scanning a document image, a document reading unit 112 having an optical imaging lens 110 and a photoelectric conversion element 111. .

In the image forming apparatus having the above-described configuration, an image of a document placed on the platen glass 113 of the document table 102 is scanned by a scanning optical system of the scanner section B, and the image data is optically reflected as a reflected light image. Imaging lens 1
From 10, the light is guided to a photoelectric conversion element 111, where it is converted into an electric signal, and then subjected to signal processing in an image processing unit 104. Thereafter, document image data is given from the image processing unit 104 to the optical scanner unit 103, further developed by the image forming unit 105, and a toner image is transferred onto a sheet supplied from the sheet feeding unit 107. Then, finally, the sheet subjected to the toner fixing process in the fixing unit 106 is discharged from the outer shell 101 of the main body.

In such a configuration, conventionally, the shift of the optical axis reaching the photoelectric conversion element 111 for reading the reflected light image from the original image in the scanner section B as image data, that is, the image distortion is adjusted. Has adjusted the height of the exposure scanning body guiding means 114 including a rail for guiding the second exposure scanning optical unit 109.

[0006]

However, when adjusting the height of the exposure scanning body guide means 114, the height adjustment screws 115 provided at both ends in the longitudinal direction of the guide means 114 are individually operated. If the height adjustment with the height adjustment screws 115 at both ends is not performed only once, the adjustment operation of the screws 115 on both sides is repeated until the image distortion falls within the allowable adjustment range. Has to be performed continuously.

FIG. 16 shows an example of the prior art:
7 shows a configuration common to that described in JP-A-7618. In the prior art example shown in this figure, an exposure scanning body guiding means 114 for guiding the second exposure scanning optical unit 109 is provided at both front and rear ends thereof, and an optical support means (not shown) is provided thereon. ) Can slide the three exposure scanning member sliding members 115 provided in (1).

The sliding member 115 on one side has a screw shape on the outside and is attached to the second exposure / scanning optical unit 109. Slider 115 into driver 1
By displacing the sliding member 115 on the one-point side in the vertical direction, for example, by rotating it using a jig such as 16 or the like, the second exposure-scanning optical unit 109 is moved to the three-point exposure-scanning-body sliding member 115. Were displaced using the two points as a fulcrum. However, at this time, the sliding member 115 on the one point side is used.
In order to carry out the adjustment work,-
The workability was poor in that point 3 had to be removed.

[0009]

SUMMARY OF THE INVENTION An image scanning apparatus according to the present invention has been made in view of the above-mentioned conventional problems, and has an original placing portion having a light-transmissive original placing surface; A first exposure / scanning optical unit having a document exposure light source and a first optical mirror which moves with a first set distance relationship with respect to the document placing portion, and a second set distance relationship with the document placing portion; An original scanning unit that holds and moves with a predetermined speed relationship with the first exposure scanning optical unit and has a second exposure scanning optical unit having a second optical mirror and a third optical mirror, and an optical imaging lens and a photoelectric conversion element A reflection image of a document image exposed and scanned by the first and second exposure / scanning optical units from the first optical mirror of the first exposure / scanning optical unit to the second
The light is guided to the photoelectric conversion element via the second and third optical mirrors of the exposure scanning optical unit and the optical imaging lens of the document reading unit, and the reflected light image of the document image is read as image data by the photoelectric conversion element. It is configured.

[0010] One of the features is that at least one of the first to third optical mirrors in the first or second exposure scanning optical unit is displaced in the mounting position of the mirror. And an optical mirror displacement adjusting means for adjusting the optical axis of the reflected light image of the original image. The adjusting means adjusts the displacement of the optical axis reaching the photoelectric conversion element in the first or second exposure scanning optical unit. An object of the present invention is to make it possible to adjust the optical axis by changing the position at which the optical mirror is mounted.

Second, the optical axis of the reflected light image of the original image is adjusted by displacing at least one of the first to third optical mirrors in the first or second exposure scanning optical unit. While providing an optical mirror displacement adjusting means to
The document reading unit is provided with element tilt adjusting means for rotating the photoelectric conversion element around a fulcrum present on an extension of the reading line of the photoelectric conversion element, thereby increasing the adjustable range. To reduce the amount of movement of the photoelectric conversion element,
The object is to improve the reliability of the adjusted image quality.

[0012]

An embodiment of the present invention will be described below in detail with reference to the drawings. 1 and 2
1 shows a digital image forming machine in which the image scanning apparatus of the present embodiment is incorporated. FIG. 1 shows the entire configuration, and FIG. 2 shows the configuration around an optical scanner unit contact portion. Are respectively shown. In these figures, 1
Is an outer shell of the main body of the apparatus, and a document table 2 as an original placing portion is arranged on the outer shell 1 of the main body. A scanner unit A, an optical scanner unit 3, an image processing unit 4, an image forming unit 5, a fixing unit 6, and a paper feeding unit, which are configured by the image scanning device of the present embodiment, are provided in the outer shell 1 of the present embodiment. A part 7 and the like are provided.

The image forming unit 5 includes a photosensitive drum 8 exposed by the optical scanner unit 3, a main charger 9 disposed around the drum 8 in a rotation direction thereof,
It comprises a developing unit 10, a transfer charger 11, a separation charger 12, and a cleaning unit 13. The document table 2 is provided on the upper surface of the outer shell 1 of the main body, and includes a platen glass 14 functioning as a light-transmitting document placing surface, and a document holder 15 provided on the platen glass 14 so as to be freely opened and closed. .

The scanner section A has first and second exposure scanning optical units 16 and 17 constituting a scanning optical system for scanning a document image, and a photoelectric conversion element 19 including an optical imaging lens 18 and a CCD sensor. Document reading unit 2
0.

An original M placed on the platen glass 14 so as to be pressed by the original holder 15.
The image shown in FIG. 6 is scanned by the scanning optical system of the scanner unit A, and the image data is guided as a reflected light image from the optical imaging lens 18 to the photoelectric conversion element 19, where it is converted into an electric signal. Thereafter, the image processing section 4 performs signal processing. Thereafter, the original image data is provided from the image processing unit 4 to the optical scanner unit 3.

On the other hand, while the photosensitive drum 8 rotates, its surface is charged by the discharging operation of the main charger 9, and thereafter, the original image is statically placed on the charged surface of the photosensitive drum 8 by the optical scanner unit 5. The latent image is drawn as an electrostatic latent image, and then charged toner is attached to the electrostatic latent image by the developing unit 10 to form a toner image of a document image.

The paper supply unit 7 is loaded with a plurality of paper supply cassettes 21 containing papers of various sizes, and a single-sheet paper is transferred from the paper supply cassette 21 selected as an alternative. The toner image on the surface of the photosensitive drum 8 is transferred onto a sheet by the transfer charger 11. After the transfer to the paper is completed, the toner remaining on the surface of the photosensitive drum 8 is removed by the cleaning unit 13, and after the charge is removed, the photosensitive drum 8 is charged again by the main charger 9 to prepare for the next exposure.

The sheet on which the toner image has been formed in this manner is separated from the transfer charger 11 by the separation charger 12, and then conveyed to the fixing unit 6 by the sheet conveying unit 22, where the toner is heated and pressed. After undergoing the fixing process, it is finally discharged from the outer shell 1 of the main body.

In the digital image forming machine configured and operated as described above, the first one of the image scanning apparatus of the present embodiment is used.
The exposure scanning optical unit 16 includes a halogen lamp unit 23 serving as a document exposure light source, and a first optical mirror 24 (deflecting the optical axis direction of a reflected light image of the document image on the platen glass 14 irradiated on the halogen lamp unit 23). FIG.
) Is mounted on a pair of front and rear first guide rails 26 erected in parallel with the original table 2 below the original table 2 so as to be movable. It moves with a certain distance in the vertical direction with respect to the table 2.

The second exposure and scanning optical unit 17 includes a second optical mirror 27 for deflecting the optical axis direction of the reflected light image of the original image from the first optical mirror 24 of the first exposure and scanning optical unit 16, and the second optical mirror 27. A second exposure scanning body 29 mounted with a third optical mirror 28 for deflecting the optical axis direction of the reflected light image from the optical mirror 27 toward the optical imaging lens 18 is moved below the first guide rail 26 to a document. It is movably mounted on a pair of front and rear second guide rails 30 provided in parallel with the table 2, and has a certain distance in the vertical direction with respect to the document table 2, and the first exposure scanning optical unit 16. And move with a predetermined speed relationship.

As described above, the original image is exposed and scanned by the first and second exposure / scanning optical units 16 and 17, and the reflected light image is transmitted from the first optical mirror 24 of the first exposure / scanning optical unit 16 to the second The light is guided to the photoelectric conversion element 19 via the second and third optical mirrors 27 and 28 of the exposure scanning optical unit 17 and the optical imaging lens 18 of the document reading unit 20.

In the present embodiment, the first to third optical mirrors 2 in the first and second exposure / scanning optical units 16 and 17 are used.
Each of 4, 27 and 28 is provided with an optical mirror displacement adjusting structure for adjusting the optical axis of the reflected light image of the original image by displacing the mounting position. FIG. 3 shows a displacement adjusting structure of the second optical mirror 27 of the second exposure scanning optical unit 17.
4 shows the displacement adjusting structure of the third optical mirror 28, and FIG. 5 shows the first optical mirror 2 of the first exposure / scanning optical unit 16.
4 shows a displacement adjustment structure. In this embodiment, since the displacement adjusting structures of the first to third optical mirrors 24, 27, 28 are basically common, the second mirror 27 in the second exposure scanning optical unit 17 shown in FIG.
This will be described below.

As shown in FIG. 3, the second exposure scanning body 29 of the second exposure scanning optical unit 17 is arranged in a bridge shape between the front and rear second guide rails 30, and is located on the rear end side in the figure. There are three sliders 31 as exposure / scanning body sliding means, one at the center in the moving direction (not shown) and one at both ends in the moving direction on the front end side.
Thereby, it is slidably supported at three points on the second guide rail 30. Further, a housing 32 supporting the second and third optical mirrors 27 and 28 is fixed to the second exposure scanning body 29 in an upright posture so as to penetrate vertically.

An optical axis adjusting plate 33 for supporting the second optical mirror 27 is attached to the housing 32. A mirror support hole 34 is formed in the optical axis adjustment plate 33 at a predetermined inclination (45 °).
Support projections 35 projecting into the support holes 34 are provided at various places. One place on the rear end side of the housing 32 (not shown)
The second mirror 27 has a front end fitted into the mirror support hole 34,
While being supported by these three points of the support protrusion 35 and the support portion, the opposite surface of the one surface is pressed by a pressing member 36 attached to the mirror support hole 34, thereby being fixedly held in a predetermined inclined state. I have.

In the upper half of the housing 32, adjustment plate support projections 37 are provided at upper and lower portions, respectively, and screw holes (not shown) are provided between the support projections 37. On the other hand, on one end side of the optical axis adjustment plate 33, three long holes 39 to 41 into which the adjustment plate support protrusion 37 and the screw 38 are fitted.
Are provided at predetermined intervals in the vertical direction. An adjusting plate pressing member 42 is attached to an upper end portion of the housing 32, and an eccentric screw 43 is provided on a base end side of the housing 32.
Mounting holes (not shown) are provided.

After the adjustment plate pressing member 42 is engaged with the upper side of the optical axis adjustment plate 33, the upper and lower slots 39 and 41 are fitted into the adjustment plate support projection 37, and the center slot 40 and the screw are inserted. By tightening the screw 38 over the hole, the optical axis adjustment plate 33 holding the second mirror 27 can be adjusted by the adjustment plate pressing member 4.
2 and is mounted on the housing 32 in a state where it can be displaced vertically by the eccentric screw 43 while being pressed downward.

By configuring the displacement adjusting structure of the second optical mirror 27 as described above, the optical axis L reaching the photoelectric conversion element 19 can be adjusted. That is, as shown in FIG. 6, when the second mirror 27 is moved upward by the length l, the optical axis L is shifted by the length l on the original image, and the image is distorted. In other words, as shown in FIG. 7 (B), the position of the second optical mirror 27 is adjusted by turning the eccentric screw 43 on the image whose both sides are distorted by the shift amount x before the adjustment. Can be adjusted within the allowable range. In FIG. 7B, the deviation amount (x / 2) of the adjusted image is an adjustment allowable value.

The displacement adjusting structure of the third optical mirror 28 of the second exposure scanning optical unit 17 shown in FIG. 4 is substantially symmetric with respect to the displacement adjusting structure of the second optical mirror 27 with respect to the second guide rail 30. It is configured. Further, the displacement adjusting structure of the first optical mirror 24 in the first exposure scanning optical unit 16 shown in FIG. 5 has substantially the same configuration as the displacement adjusting structure of the second optical mirror 27. Therefore, in FIGS. 4 and 5, portions having the same configuration and operation as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted to avoid duplication. FIG. 7A shows before and after adjustment of the first optical mirror 24 in the first exposure scanning optical unit 16.

The first to third optical mirrors 24, 27,
By configuring the displacement adjusting structure 28 as described above, as shown in FIGS. 1 and 9, by providing the adjusting hole 44 of the eccentric screw 43 on the side wall 1 a of the outer shell 1 of the image forming machine, Lateral direction of image forming machine, for example, scanner unit A
The jig such as the driver 45 can be inserted from the adjustment hole 44 to adjust the position of at least one of the optical mirrors 24, 27, and 28 from the outside, and the eccentric screw 43 can be rotated. Therefore, unlike the related art, there is no need to remove the platen glass 14 to adjust the height of the optical mirrors 24, 27, and 28, and the adjustment work efficiency is improved.

Next, the first to third optical mirrors 24, 27,
When the displacement of the mounting position of the scanner 28 is adjusted, in the scanner unit A, as shown in FIG. 9, the image of the document M is formed on the photoelectric conversion element 19 by the optical imaging lens 18 and reduced. The reduction ratio is set to, for example, n / m = about 1/9 depending on the pixel size of the photoelectric conversion element 19.

Therefore, as the first to third optical mirrors 24, 27, and 28 are farther from the photoelectric conversion element 19, the influence of the adjustment amount upon the optical axis adjustment on the photoelectric conversion element 19 becomes smaller. A state in which the first exposure scanning optical unit 16 and the second exposure scanning optical unit 17 are closest to each other, that is, a state in which the first to third optical mirrors 24, 27, and 28 are farthest from the photoelectric conversion element 19. In the first to third
By displacing the mounting positions of the optical mirrors 24, 27, and 28 to adjust the optical axis L of the reflected light image of the original image, the reliability of the image is improved.

At this time, in the scanner section A, the scanning start state of the document M placed on the document table 2 is usually determined by the distance between the first exposure scanning optical unit 16 and the second exposure scanning optical unit 17. When the optical axes of the reflected light images of the original image are adjusted by displacing the mounting positions of the first to third optical mirrors 24, 27, and 28, the optical axis L Is reduced when the light is incident on the optical imaging lens 18, and as a result, the displacement of the optical axis L to the photoelectric conversion element 19 is reduced, so that the adjustment accuracy in the optical axis adjustment is improved. Therefore, in order to correspond to this positional relationship, the above-described adjustment hole 44 is formed in the outer shell 1 of the image forming apparatus main body.
In this case, the reliability of the image of the optical axis adjustment work by always adjusting the displacement of at least one of the first to third optical mirrors 24, 27, 28 is improved.

Further, since the first optical mirror 24 in the first exposure / scanning optical unit 16 is farthest from the photoelectric conversion element 19 of the original reading unit 20 in the scanning optical system, the optical axis L reaches the photoelectric conversion element 19. Since the displacement is minimized, the displacement adjusting structure shown in FIG.
Adjusting the displacement of the mounting position of the optical mirror 24 increases the adjustment accuracy, and can improve the reliability of the image of the optical axis adjustment most.

As shown in FIG. 10, the second optical mirror 27 and the third
In the case where the mounting position of the optical mirror 28 is displaced and adjusted by providing the optical axis adjusting plate 33 for the reflected light image of the original image, the amount of movement between the second optical mirror 27 and the third optical mirror 28 is determined by the third optical mirror. After setting the moving amount larger than the second optical mirror moving amount and adjusting the distance between the third optical mirror 28 and the photoelectric conversion element 19 of the document reading unit 20,
That is, after the coarse adjustment by the displacement adjustment of the third optical mirror 28 is performed, the distance between the first optical mirror 27 of the first exposure scanning optical unit 16 and the second optical mirror 28 of the second exposure scanning optical unit 17 is adjusted. That is, by performing the fine adjustment by adjusting the displacement of the first optical mirror 24, the adjustment accuracy of the optical axis L is improved, and the reliability of the image is improved.

In this case, usually in the scanner section A,
In a state where the first exposure scanning optical unit 16 and the second exposure scanning optical unit 17 are closest to each other, that is, in a state where scanning of the document M placed on the document table 2 is started, the first exposure scanning optical unit 16 and the second exposure scanning optical unit 17 start scanning as shown in FIG. The positional relationship between the first to third optical mirrors 24, 27, and 28 and the photoelectric conversion element 19 is obtained. The first optical mirror 24, the second optical mirror 27, and the third optical mirror 28 with respect to the photoelectric conversion element 19 at that time. Positional relationship (distance ratio)
Is, for example, the ratio of the distance m between the optical imaging lens 18 and the document to the distance n between the optical imaging lens 18 and the photoelectric conversion element 19 as described above.
m: n ≒ 9: 1. Similarly, the ratio of the distance between the optical imaging lens 18 and the first optical mirror 24 is m ₁ : n ≒ 8: 1 The ratio of the distance between the optical imaging lens 18 and the second optical mirror 27 is m ₂ : n ≒ The ratio of the distance between the 7: 1 optical imaging lens 18 and the third optical mirror 28 is m ₃ : n ≒ 6.5: 1, and the rotation adjustment amount at the position of the photoelectric conversion element 19 is generally about 0.1 mm. Therefore, the adjustment amounts of the first optical mirror 24, the second optical mirror 27, and the third optical mirror 28 increase due to the reciprocal of the distance ratio.

As described above, the second exposure scanning optical unit 17
When adjusting the optical axis of the reflected light image of the original image by displacing the mounting positions of the second and third optical mirrors 27 and 28 in the above, the third optical mirror movement amount> the second optical mirror movement amount, and After adjusting the distance between the third optical mirror 28 and the photoelectric conversion element 19, the first
The optical mirror 24 and the second exposure / scanning optical unit 17
The optical axis of the reflected light image of the original image is adjusted by adjusting the distance between the optical mirror 27 and the optical mirror 27.

As a result, the first optical mirror 27
The optical axis is adjusted between the exposure / scanning optical unit 16 and the second exposure / scanning optical unit 17. The third optical mirror 28 controls the second exposure / scanning optical unit 17 and the original reading unit 2.
Since the optical axis is adjusted between 0 and 0, the third optical mirror 28
The optical axis is roughly adjusted by the displacement of the second optical mirror 27.
Fine adjustment can be performed by the displacement of the optical axis, and as a result, the adjustment accuracy at the time of optical axis adjustment is improved.

Further, as shown in FIG.
3 instead of the second optical mirror 27 and the third optical mirror 28
In order to simultaneously move and adjust the optical axis adjusting plate 33, an eccentric cam 46 common to both is provided, and the moving amount of the second optical mirror 27 and the third optical mirror 28 is changed by the second optical mirror. By making the adjustment larger than the mirror movement amount and performing the adjustment at the same time, the adjustment time can be further reduced.

Here, as shown in FIG. 13, the eccentric cam 46 has a radius r _{2 at} which the displacement adjusting center O ₂ of the third optical mirror 28 is located at a position away from the rotation center O _{1 in the} opposite direction. of an arc C ₂ parts, and a circular arc C ₃ parts of a radius r ₃ that is displaced for adjusting the center O ₃ of the second optical mirror 27, from the rotation center O ₁ of the eccentric cam 46, each arc C ₂ Part and C ₃
The difference between the distances r ₄ and r ₆ at the minimum adjustment amount and the distances r ₅ and r ₇ at the maximum adjustment amount is (r ₅ −r ₄ )> (r ₇ −r ₆ ).
There is a relationship.

As described above, the second exposure scanning optical unit 1
7, the mounting positions of the second and third optical mirrors 27 and 28 are simultaneously displaced to adjust the optical axis of the reflected light image of the original image, and the third optical mirror movement amount> the second optical mirror movement amount. Accordingly, it is possible to shorten the adjustment time when adjusting the optical axis, and it is possible to improve the adjustment accuracy.

Next, the procedure for adjusting the original reading unit 20 will be described. Before the document reading unit 20 is incorporated in the scanner unit A, the focus, magnification, optical axis of the image, and the like are adjusted in advance by an optical adjustment jig (not shown). The reading unit 20 is attached in parallel with the optical axis L, and as shown in FIG. 14, a unit supporting member 47 fixed inside the image forming apparatus.
In addition, an element mounting plate 48 to which the photoelectric conversion element 19 is fixed is rotatably mounted around a rotation fulcrum 49.
The unit support member 47 is attached to the lower side of the end working piece 48a of the unit 8.
And the upper side of the end working piece 48a is pressed by the CCD substrate pressing member 51 provided on the unit support member 47, thereby making the photoelectric conversion element 19 Adjustment in the rotation direction with respect to the optical axis L can be performed.

In this manner, the first to third optical mirrors 24, 27, and 2 in the first exposure optical unit 16 or the second exposure scanning optical unit 17 depend on the optical relationship.
8, the optical axis L can be adjusted in the same manner as the displacement adjustment.

However, regarding the adjustment range, the image distortion due to the displacement adjustment of the first and second optical mirrors 27 and 28 in the second exposure scanning optical unit 17 is the same as that shown in FIG.
As shown in (1), the distortion of the image also becomes 1 with respect to the height change 1 of the second optical mirror 27. On the other hand, the original reading unit 20
As shown in FIG. 9 described above, the original image is reduced by the optical imaging lens 18 and then imaged on the photoelectric conversion element 19, and the reduction ratio is determined by the pixel size of the photoelectric conversion element 19. For example, it is about 1/9. Therefore, the distortion of the image with respect to the displacement adjustment amount of the photoelectric conversion element 19 is about nine times, and the adjustment width is larger than the displacement adjustment amounts of the first and second optical mirrors 27 and 28 in the second exposure scanning optical unit 17.

When the image of the original image and the side where the first and second optical mirrors 27 and 28 are adjusted for displacement adjustment are formed on the photoelectric conversion element 19 by the optical imaging lens 18, the light Since the image is inverted with respect to the axis L, the side on which the rotation adjustment of the photoelectric conversion element 19 is performed is disposed on the opposite side with respect to the optical axis L, so that the adjustment range of the image distortion can be adjusted by the optical mirror,
It can be larger than only one of the respective adjusting means of the photoelectric conversion element, and as a result, the adjusting work efficiency and the reliability of the image can be improved.

Further, the work of each of the adjusting means is divided.
In other words, the rotation adjustment by the photoelectric conversion element 19 having a large adjustment width is a rough adjustment performed first, and the first to third exposure scanning optical units 16 and 17 having a small adjustment width are first to third.
By performing the displacement adjustment of the optical mirrors 24, 27, and 28 as fine adjustment performed later, the adjustment accuracy and image reliability can be further improved.

[0046]

As described above, according to the first aspect of the present invention,
In order to adjust the optical axis of the reflected light image of the original image, the mounting position of the mirror is displaced to at least one of the first to third optical mirrors in the first or second exposure scanning optical unit. Optical mirror displacement adjusting means, the displacement of the optical axis leading to the photoelectric conversion element for reading the reflected light image of the original image in the image scanning device as image data can be reduced by the first or second exposure scanning optical unit. The optical axis can be adjusted by displacing the mounting position of the mirror.
It is not necessary to adjust the height of the movement guide means of the exposure scanning optical unit, and therefore, the optical axis can be easily adjusted and the adjustment time can be reduced.

According to the second aspect, at least one of the first to third optical mirrors is displaced in a state where the distance between the first exposure scanning optical unit and the second exposure scanning optical unit is closest. Thus, the optical mirror displacement adjusting means is configured to adjust the optical axis of the reflected light image of the original image. In the state where the first exposure scanning optical unit and the second exposure scanning optical unit are closest to each other, the second exposure scanning optical unit is farthest from the document reading unit. When adjusting the optical axis of the reflected light image of the original image by displacing the mounting positions of the first, second, and third optical mirrors,
The deviation when the optical axis is incident on the optical imaging lens is reduced, and as a result, the deviation of the optical axis to the photoelectric conversion element is reduced, so that the adjustment accuracy when adjusting the optical axis can be improved.

According to the third aspect, the positions of the second and third optical mirrors in the second exposure scanning optical unit are displaced to adjust the optical axis of the reflected light image of the original image. Since the optical mirror displacement adjusting means is configured so that the amount of movement of the second optical mirror is different from the amount of movement of the third optical mirror, the second optical mirror uses the first exposure scanning optical unit and the second exposure scanning optical unit. And the third optical mirror adjusts the optical axis between the second exposure scanning optical unit and the original reading unit.
The optical axis is roughly adjusted by the displacement of the third optical mirror.
Since the fine adjustment can be performed by the displacement of the optical mirror, the adjustment accuracy at the time of optical axis adjustment can be improved.

According to the fourth aspect, at least one of the first to third optical mirrors is displaced by the first or second exposure scanning optical unit to adjust the optical axis of the reflected light image of the original image. While the optical mirror displacement adjusting means is provided, the document reading unit is provided with element inclination adjusting means for rotating the photoelectric conversion element around a fulcrum existing on an extension of the reading line of the photoelectric conversion element. The amount of adjustment increases by the amount of adjustment performed by the element tilt adjustment means,
The adjustable range can be increased. That is, since there is a limit to the adjustment width by the displacement adjustment of the optical mirror, the adjustment range can be increased by adjusting the inclination of the read line of the photoelectric conversion element. And conversely,
Since the amount of adjustment by the tilt adjusting means in the photoelectric conversion element can be reduced, the amount of movement of the photoelectric conversion element is reduced, and the reliability of the adjusted image quality can be improved.

According to the fifth aspect, since the adjustment amount by the inclination adjusting means of the photoelectric conversion element is set to be larger than the adjustment amount by the optical mirror displacement adjusting means, fine adjustment can be performed accordingly. As a result, the adjusted image quality can be improved.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional front view showing an entire configuration of a digital image forming apparatus in which an image scanning device according to an embodiment of the present invention is incorporated.

FIG. 2 is a sectional view taken along section line PP of FIG. 1;

FIG. 3 is an enlarged front view of a main part showing a second optical mirror displacement adjusting structure.

FIG. 4 is an enlarged front view of a main part showing a third optical mirror displacement adjusting structure.

FIG. 5 is an enlarged front view of a main part showing a first optical mirror displacement adjusting structure.

FIG. 6 is a diagram illustrating a state of image distortion due to displacement adjustment of a second optical mirror.

FIG. 7 is a diagram showing a change in image distortion due to displacement adjustment of a first or second exposure scanning optical unit and a photoelectric conversion element.

FIG. 8 is a cross-sectional view of the scanner showing an adjustment operation when adjusting the displacement of the first or second exposure scanning optical unit.

FIG. 9 is a schematic configuration diagram showing a reduction optical system in a scanner unit.

FIG. 10 is an enlarged front view of a main part showing an adjustment structure including displacement adjustment of a second optical mirror and a third optical mirror.

FIG. 11 is a configuration diagram showing a positional relationship between an optical mirror and a photoelectric conversion element in a state where the first exposure scanning optical unit and the second exposure scanning optical unit are closest to each other;

FIG. 12 is an enlarged front view of a main part showing an adjustment structure having displacement adjustment of a second optical mirror and a third optical mirror, and further displacing them simultaneously.

FIG. 13 is an enlarged view showing a detailed shape of an eccentric cam for a second optical mirror and a third optical mirror optical axis adjusting plate for simultaneously adjusting the displacement of the second optical mirror and the third optical mirror;

FIG. 14 is a perspective view showing an adjustment structure of a rotation adjustment unit of the photoelectric conversion element.

FIG. 15 is a vertical sectional front view showing the entire configuration of a conventional digital image forming machine.

FIG. 16 is a cross-sectional view of a scanner unit showing a displacement adjustment method using a slide member of an exposure scanning body of a second exposure optical scanning unit in a conventional image scanning apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Outer shell 2 Original platen 14 Platen glass 16 1st exposure scanning optical unit 17 2nd exposure scanning optical unit 18 Optical imaging lens 19 Photoelectric conversion element 20 Document reading unit 23 Halogen lamp unit 24 1st optical mirror 26 1st guide Rail 27 Second optical mirror 28 Third optical mirror 30 Second guide rail 31 Slider 32 Housing 33 Optical axis adjustment plate 34 Mirror support hole 35 Support protrusion 36 Press member 37 Adjust plate support protrusion 38 Screw 42 Adjust plate press member 43 Eccentric screw 44 Adjustment hole 46 Eccentric cam 47 Unit support member 48 Element mounting plate 49 Rotation fulcrum 50 Displacement adjustment screw 51 CCD substrate pressing member

Claims (5)

[Claims] A first document placement unit having a light-transmissive document placement surface, a document exposure light source moving with a first set distance to the document placement unit, and a first optical mirror. An exposure / scanning optical unit, a second set distance relationship with the original placing unit, and a movement with a predetermined speed relationship with the first exposure / scanning optical unit; And a document reading unit having an optical imaging lens and a photoelectric conversion element. The reflected light image of the document image exposed and scanned by the first and second exposure scanning optical units is provided. The photoelectric conversion from the first optical mirror of the first exposure scanning optical unit via the second and third optical mirrors of the second exposure scanning optical unit and the optical imaging lens of the document reading unit Lead to the child, in the image scanning apparatus configured to read the reflected light image of an original image as image data by photoelectric conversion elements, first in the first or second exposure scanning optical unit 1
Image scanning, wherein at least one of the third optical mirror is provided with optical mirror displacement adjusting means for adjusting the optical axis of the reflected light image of the original image by displacing the mounting position of the mirror. apparatus. 2. The optical mirror displacement adjusting means according to claim 1, wherein at least one of the first to third optical mirrors is mounted in a state in which the distance between the first exposure scanning optical unit and the second exposure scanning optical unit is closest. 2. The image scanning device according to claim 1, wherein the image scanning device is configured to adjust the optical axis of the reflected light image of the document image by displacing the image light. 3. The optical mirror displacement adjusting means adjusts the optical axis of the reflected light image of the original image by displacing the mounting positions of the second and third optical mirrors in the second exposure scanning optical unit, and , The amount of movement of the second optical mirror and the third
The image scanning device according to claim 1, wherein a moving amount of the optical mirror is different. 4. A document placement unit having a light-transmissive document placement surface, a document exposure light source moving with a first set distance to the document placement unit, and a first optical mirror having a first optical mirror An exposure / scanning optical unit, a second set distance relationship with the original placing unit, and a movement with a predetermined speed relationship with the first exposure / scanning optical unit; And a document reading unit having an optical imaging lens and a photoelectric conversion element. The reflected light image of the document image exposed and scanned by the first and second exposure scanning optical units is provided. The photoelectric conversion from the first optical mirror of the first exposure scanning optical unit via the second and third optical mirrors of the second exposure scanning optical unit and the optical imaging lens of the document reading unit Lead to the child, in the image scanning apparatus configured to read the reflected light image of an original image as image data by photoelectric conversion elements, to the first or second exposure scanning optical unit, the first
An optical mirror displacement adjusting means for adjusting the optical axis of the reflected light image of the original image by displacing at least one of the mounting positions of the third optical mirror; and a reading line of the photoelectric conversion element in the original reading unit. An image scanning apparatus, further comprising an element tilt adjusting means for rotating the photoelectric conversion element about a fulcrum existing on an extension of the image scanning device. 5. The image scanning device according to claim 4, wherein the adjustment amount of the photoelectric conversion element by the inclination adjustment unit is set to be larger than the adjustment amount by the optical mirror displacement adjustment unit.