JPH033552A - Position adjustment mechanism for picture reader - Google Patents

Abstract

PURPOSE:To adjust and position projection magnification of an original picture and focus to a CCD photodetection face easily with high accuracy by providing a support shaft supporting a rotary board with respect to a base movably in a lens optical axis direction. CONSTITUTION:A read unit 15 is provided with a base plate 100 whose cross section is channel shape mounted movably for parallel minute adjustment in the optical direction (Z axis direction) of an image forming lens 5 with respect to a base 200, a rotary base plate 80 mounted in a way of rotation minute adjustment around a conical shaft having a shaft center in the subscanning direction at a right angle to the optical axis with an optical center of the image forming lens 5 to the base plate 100, a support shaft 64 provided between a right boss 81 and a left boss 82 screwed to the lower part of a right side wall 80a and a left side wall 80b of the rotary base plate 80 and a CCD base plate unit 30 mounted in slide minute adjustment in the axial direction and in a way of rotary minute adjustment, with respect to the support shaft 64. Thus, the image forming lens 5 and photoelectric conversion elements 1-3 are moved and adjusted integrally and the position deviation of the both is not caused.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides photoelectric conversion of an original image by relatively moving an original image projected by an imaging lens and a photoelectric conversion element for reading the original image in the sub-scanning direction. The present invention relates to a position adjustment mechanism for an image reading device that reads images.

[Prior Art] In recent years, optical reading devices for document images have been widely used in office equipment such as copying machines and facsimile machines. The size of documents to be read in general is limited to a maximum of A3 size,
In certain fields such as industrial drawings, the size of target manuscripts is increased from 841 on + (JISAO size) to 3611 (941 mm) (ANSI E size). For such large documents, it is impossible to reduce and project the image onto a single photoelectric conversion element (hereinafter referred to as CCD) and read the image, so conventional general office reading devices cannot provide sufficient images. It is not possible to read by density.

Therefore, an apparatus has been proposed in which a large document image is dividedly projected onto a plurality of CCDs using a plurality of imaging lenses, and the image is read in correspondence with each projected image.

[Problems to be Solved by the Invention] However, in such a split-type reading device, for example, not only the main scanning direction of each CCD perfectly matches the width direction of the original image, but also the COD of each CCD in the sub-scanning direction. It is impossible to photoelectrically read the original image unless the original image and the photoelectric conversion element are moved relative to each other after being positioned so that the original image is perpendicular to the optical axis.

In particular, for high-density CCD linear sensors used when high-density reading is required, highly accurate position adjustment must be performed in relation to the projection magnification or reading overlap amount for each CCD, as well as temperature changes. .

On the other hand, the lens barrels that make up the imaging lenses are processed and assembled with high precision, and each imaging lens must have no variation in focal length or back focus. C corresponding to multiple imaging lenses, respectively.
It is essential to adjust the distance to the CD original image exposure surface, that is, the projection magnification. Furthermore, the distance between the imaging lens and the CCD must be adjusted and positioned within a range that satisfies a predetermined projection magnification and the required imaging accuracy, that is, resolution.

Conventionally, in Japanese Patent Application Laid-Open No. 51-51217, etc.,
Various support structures for the CCD and the imaging lens have been proposed, but in all of them, when moving the distance between the original image exposure surface and the COD to a position corresponding to the required projection magnification, it is necessary to Positional deviation occurs and the in-focus state is impaired.

The present invention is characterized by the projection magnification of an original image by an imaging lens and CO
D Focusing on the light receiving surface easily and with high Rff degree'jA
An object of the present invention is to provide a position adjustment mechanism for an image reading device that can perform m positioning.

[Means for Solving the Problems] In order to achieve the above object, the invention described in claim 1 projects a document image onto a photoelectric conversion element using an imaging lens, and combines the document image and the photoelectric conversion element. In the position adjustment mechanism of an image reading device that photoelectrically reads a document image by relatively moving the two in the sub-scanning direction, a movable base plate holding the photoelectric conversion element is supported movably in the main-scanning direction; and a white plate that rotatably supports a lens support member that holds an imaging lens in a direction perpendicular to the optical axis; a base that is immovable in the main scanning direction with respect to the original reading position; On the other hand, the base plate is configured to include a support shaft that holds the base plate movably at least in the direction of the optical axis of the lens.

Further, the invention described in claim 2 is such that in the position:A adjustment mechanism of the image reading device described in claim 1, the lens support member holding the imaging lens is arranged to Supported rotatably around an axis in the sub-scanning direction of the photoelectric conversion element and orthogonal to the optical axis of the imaging lens at or near the optical center between the front principal point and the rear principal point of the imaging lens. It has the following configuration.

Furthermore, the invention described in claim 3 is based on claim 1.
In the position adjustment mechanism for an image reading device described in , a means for compressing and biasing a member holding a rotating base plate against the base, and a means for fastening the member holding the rotating base plate and the base. The device has a configuration including means.

[Function] In the means having such a configuration, the imaging lens and the photoelectric conversion element are moved and adjusted as one, so that positional deviation between them does not occur.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

As shown in FIG. 1, the original 12 is illuminated by a long illumination lamp 11, thereby causing the JJ'Av!
The image on 112 is converted into one-dimensional photoelectric conversion element (
(hereinafter abbreviated as COD) is projected onto a pixel column of 1.2°3.

Each light beam 7°8.9 in the imaging lenses 4, 5.6 is distributed over a predetermined area Q1□-Ω23 in the exposure line 13.
are overlapped, and when the read signals from the CCDIs, 2 and 3 are output to a writing device (not shown), it is made to prevent omissions, duplications, and shifts from occurring at predetermined positions in the respective overlap areas. controlled.

The document 12 is conveyed by a conveying means (not shown) along an exposure line 13 on a transparent flat glass plate from its leading edge to its trailing edge in the direction of the arrow shown in the figure at a speed corresponding to a predetermined reading speed. This allows all images of the document to be read.

Further, as shown in FIG. 2, an area 122 on the exposure line 13 of the original 12 is formed by the imaging lens 5 at 0.000.
The image is reduced by 1102 times and imaged on the C0D2 pixel column. The CCD 2 consists of a linear sensor having 5000 pixels (picxels) of 7 μm x 7 μm, and the length of the pixel row is set to 35 nm. Therefore, the area 12. The length of is 317.
It will be made to have a thickness of 5 nm. Here, the width of the original 12 on the exposure line 13, that is, the maximum reading width Ω, is 914.4un.
Then, the overlap on the exposure line 13 is nQ□.

-Q23 is 6.35m+, and pixel row 2 of CCD2
On a, it is 0.7un (IQQ pixel).

In this way, the image of the original 12 is transferred to multiple CGDIs.

In order to read the image separately according to 2.3, each CGDI, the reading magnification and position of the read image in 2.3,
The range etc. needs to be positioned with a predetermined accuracy. Therefore, in this embodiment, as shown in FIG.
The position of 2 is movable for parallel fine adjustment in each direction: the X-axis direction which is the main scanning direction, the Y-axis direction which is the sub-scanning direction, and the Z-axis direction which is the optical axis direction of the imaging lens 5. , can be rotated and finely adjusted around each of the X-axis direction, Y-axis direction, and Z-axis direction.

As shown in FIGS. 3, 4, and 5, the reading unit 15 has an imaging lens 5 with respect to the base 200.
A base plate 100 having a U-shaped cross section is mounted for parallel fine adjustment movement in the optical axis direction (Z-axis direction), and the optical center of the imaging lens 5 is perpendicular to the optical axis with respect to this base plate 100. , and a rotary base plate 80 mounted for fine rotational adjustment around a conical shaft 94 having an axis in the sub-scanning direction; a shading correction plate 97 movably screwed to the
The optical center of the imaging lens 5 is screwed to approximately the center of the front side wall 80c of the rotary base plate 80 so as to allow fine rotational adjustment around a conical shaft 94 having an axis perpendicular to the optical axis and in the sub-scanning direction. A support shaft 64 is provided between the lens unit 300 and the right boss 81 and left boss 82 screwed to the lower portions of the left side wall 80a and the left side wall 8ob of the rotating base plate 80. , and a CCD base plate unit 30 mounted on the support shaft 64 so as to be finely adjustable in rotation and finely adjustable in the axial direction.

The CCD unit 20 is held in the CCD base plate unit 30, and a sealing member 310 having light-shielding properties, dust-proofing properties, and air permeability is installed between the CCD unit 20 and the lens unit 300. .

Further, as shown in FIGS. 14, 15, and 16, the base 200 is connected to the exposure line 13 of the original image.
The left support frame 230 is provided as an immovable member.
It is rotatably supported on the right support frame 231 via an upper left shaft 215 and an upper right shaft 217. Its rotation plane is set to a plane that includes the optical center of the imaging lens 5 and is orthogonal to the optical axis of the imaging lens 5. It has an axis in a direction parallel to the line 13. Further, two stop shafts 214 are provided on both sides of the right main shaft 215 in the direction perpendicular to the axis, and when these stop shafts 214 are tightened or loosened by set screws 222 and 223, the base 200 is rotated. Motive! l! It is designed to be 1ffu.

The CCD 2 of the CCD unit 20 is fitted into a substantially rectangular positioning hole 21g provided in the metal plate 21, as shown in FIGS. 7 and 8. Three support pieces are formed at the edge of the positioning hole 21g to protrude inward, and a main scanning direction reference edge 21a and a sub-scanning direction reference edge 21a are formed at the tips of each of these support pieces. With respect to the direction reference edges 21b and 21c, the above C
The end face in the main scanning direction and the end face in the sub-scanning direction of the ceramic case of the CD 2 are held in contact with each other. Furthermore, the main scanning direction base $921a and the sub-scanning direction reference edges 21b and 21c are accurately positioned with respect to the two mounting holes 21e provided in the metal plate 21, so that the pixel row 2a of the CCD 2 Positioning is performed with a predetermined accuracy. At this time, the cover glass 2 of CCD 2
b and the upper surface of the gold plate 21 are positioned on the same plane. Furthermore, a two-component epoxy resin is injected and hardened into the gap between the ceramic case of the CCD 2 and the positioning hole 21g, so that the CCD 2 remains immovable.

Also, a CCD including an amplification circuit for amplifying the image reading signal from the CCD 2? l+IJ goita r'CI! -122 is soldered and held to the 22 connection pins 2c of C0D2. Two connectors 23 are soldered to the CCD control board PCB-122, and flat cables 24 each consisting of a plurality of lead wires are detachably attached to the CCD control board PCB-122. A thermistor 25 for detecting the temperature of the CCD 2 is installed in the mounting hole 22a provided in the CCD control board PCB-122, and is held adhesively with epoxy resin while in contact with the ceramic case of the CCD 2. It looks like this.

Furthermore, CCD control board PCI! -122 has connector 2
3 is soldered, and one end of a flat cable 24 is inserted into this connector 23.

The other end of the flat cable 24 is connected to a CCD control board P.
The connector 401L soldered to the CB-2400 (see FIGS. 3 and 5) is inserted and connected. The above COD control board PC: B-2400 is a CC
It constitutes the following motion control circuit of D2, and the CO
It is larger than the D control board PCB-122 and has more control electronic components mounted thereon, and therefore generates more heat. Therefore, it is desirable that the COD control board PCB-2400 is installed as far away from the CCD 2 as possible, and in this embodiment, the COD control board PCB-2400 is installed with respect to the right support leg 100d and the left support leg 100s extending downward from the base plate 100. By being locked by the screw 404, the COD control board PC
The heat generated by B-122 is prevented from affecting the CCD2.

The CCD control plates PCl3 spaced apart from each other in this way
-122 and the CCD control board I'C [1-2400] are connected by a flat cable 24, electrical noise is picked up through the flat cable 24, and an accurate signal corresponding to the original image can be output. Therefore, in this example, as described above,
CCP control board PCB-12 directly connected to C0D2L
2 is provided with a read signal amplification function, thereby minimizing the influence of electrical noise. As a result, the flat cable 24 can be made longer to some extent, which allows the CCD control board r'cn-24 to
The positional constraints of 00 are relaxed, and even if the CCD 2 is adjusted in position over a relatively large range, no excessive force is applied to the CCD 2, and connection failures between the flat cable 24 and the connectors 23, 401 are eliminated. It is now possible to do so.

9 and 10 show other mounting structures for the CCD 2. In other words, in the total part of the positioning hole 21g,
Main scanning direction reference edge 21a and sub scanning direction reference 921b
, 21c, there are three optical axis direction references g21f, and CC
The cover glass 2b of D2 is brought into contact and positioned. A two-component epoxy resin is injected and hardened into the gap 21d between the ceramic case of the CCD 2 and the positioning hole 21g, so that the C0D2 remains immovable.

In this way, positioning of the CCD 2 with respect to the metal plate 21 in the optical axis direction can be facilitated.

Further, FIG. 11 shows another mounting structure for the COD control plate PC+3-122. That is, a socket 26 is connected to the COD control board PCB-122 via a connecting pin 26a, and a connecting pin 2c of the CCD 2 is inserted into the socket 26. By doing this, connecting pin 2c of C0D2 can be connected to socket 1-26.
By inserting it into the PC row 122, it is possible to easily and inexpensively replace the CCD 2 or the CCD control plate PC row 122.

Next, the lens unit 300 will be explained with reference to FIGS. 13, 5, and 3. The lens holder 301 is made of aluminum casting in the shape of a broken circuit, and the rear part 301b of the lens holder 301 has three protrusions 301.
8 is formed, and an attachment hole 303 to the rotating base plate 80 is also formed. The protruding tip plane part of the convex part 301e and the holder lower surface part 301d are cut so as to have a perpendicular relationship, and furthermore, with these both surfaces 301e and 301d as a reference, a fitting part for housing the imaging lens 5 is formed. A hole 304 is formed through the optical axis direction. That is, the axis of the fitting hole 304 is precisely positioned to be perpendicular to the holder lower surface 301d of the lens holder 301 and parallel to the flat surface of the protruding end of the convex portion 301e. The imaging lens 5 is fitted into the fitting hole 304 so as to be slid back and forth in the direction of its front axis.

Further, a fitting hole 302 is formed in the rear part 301b of the lens holder 301, into which the outer circumference of the cylindrical female thread 95 is fitted. The cylindrical female thread 95 locks the cone @94 to the front wall 80c of the rotating base plate 80. At this time, the formation position of the fitting hole 302 is precisely set on the optical center of the imaging lens 5 in a direction perpendicular to the optical axis of the lens and perpendicular to the flat surface of the protruding end of the convex portion 301e. There is. On the other hand, a movable base plate 50 holding the 009 base plate unit 3o is rotatably and slidably supported on the support shaft 64, and the lens unit 300 can be rotated and adjusted around the fitting hole 302. , holder bottom part 3
01d is set to be parallel to the support axis C4, and then it is locked to the rotating base plate 80 with three screws 309. As a result, the optical axis of the imaging lens 5 and the support axis 6
4, the required perpendicularity accuracy is guaranteed.

Further, the tip of the plate spring 325 screwed to the front part 301a of the lens holder 301 is connected to the imaging lens 5.
The imaging lens 5 is pressed downward in the optical axis direction.

A fitting hole 305 is formed in the front part 301a of the lens holder 301 in a direction perpendicular to the lens optical axis.
A focus adjustment shaft 306 is rotatably fitted into the fitting hole 305 for finely adjusting and moving the imaging lens 5 in the optical axis direction for focusing and locking. Further, a screw hole 301f is formed in the front part 301a of the lens holder 301 so as to be perpendicular to the axis of the fitting hole 305, and a pressure rod 307 loosely fitted into the screw hole 301f is screwed into the screw hole 301f. 308, the focus adjustment shaft 306 is pressed in a direction perpendicular to the axis, thereby locking the focus adjustment shaft 306 at a predetermined position as described later. The pressure rod 307 is made of a flexible hard resin.

On the other hand, a groove 322 of a predetermined depth is formed in an annular shape on the outer periphery of the lens barrel 321 of the imaging lens 5.
A cylindrical eccentric cam 306a is formed at the rear end of the focus adjustment shaft 306, and this eccentric cam 306a is engaged in the groove 322. The eccentric cam 306a is formed to have a diameter of 8 m, and has a main shaft 3 of the focus adjustment shaft 306.
It is eccentric by 1.5+nu+ with respect to the axis of 06c, and the length in the axial direction is set to be longer than the depth of the groove 322. The main shaft 306c of the focus adjustment shaft 306 is formed into a cylindrical shape with a diameter of 12 mm, and a conical portion 306d with an apex angle of 90° is formed on the opposite side of the eccentric cam 306c, and this conical portion 306d serves as a small diameter shaft. It is integrally connected to the auxiliary shaft 306f via 306e. Auxiliary shaft 30
6f is formed to have the same diameter as the main shaft 306c, and the auxiliary shaft 3
A slotted portion 306g into which a driver can be fitted is formed on the end face portion of 06f. A conical portion 307a formed at the tip of the pressure rod 307 described above is pressed into contact with the conical inclined side surface of the conical portion 306d. Component force P1 of the pressing force of the pressing rod 307 at the pressure contact point between these two
and P2 are oriented in the axial direction of the focus adjustment shaft 306 and in the direction perpendicular to the axis, respectively.1. @ Directional force P
□ allows the tip surface 306b of the eccentric cam 306a to fit into the groove 3.
22, so that the lens barrel 321 is pressed against the wall surface of the fitting hole 304 and maintained without any play. In addition, the main shaft 306c and the auxiliary shaft 306 of the focus adjustment shaft 30G are pressed against the wall surface of the fitting hole 305 by the axis-perpendicular component force P2 and are maintained in a state without play, and the rotation of the focus adjustment shaft 306 is braked by the frictional force. It has become so. At this time, the groove bottom surface 3 formed by the end surface 306b of the eccentric cam 306a
22a, that is, the lens barrel 321 and the fitting hole 3
04 is caused by the set screw 308 against the pressure rod 307.
However, at least when the imaging lens 5 focuses the projected image on the CCD 2, the frictional force between the lens fii 321 and the fitting hole 304 is due to the force of the plate spring 325 against the lens opening 321. The set screw 30 is attached to the pressure rod 307 to an extent that the pressure is not greater than the pressing force.
The suppression power from 8 has been adjusted.

To adjust the focus of the imaging lens 5, first, a driver is engaged with the slotted portion 306g and the focus adjustment shaft 306 is rotated. As a result, the eccentric cam 306a is eccentrically rotated, and the imaging lens 5 is moved in the optical axis direction, so that the CCD 2
The focus of the projected image is adjusted. At this time, the imaging lens 5 is prevented from rotating around the optical axis by the pressing force of the leaf spring 325, and the groove 3
The groove side surface 322b of No. 22 is maintained in pressure contact with the cam surface of the eccentric cam 306a.

As a result, the imaging lens 5 is always movable for fine focusing adjustment in the most desirable direction for reading the original image, that is, in the direction to eliminate single-focal blur in the main scanning direction, and at this time, in the optical axis direction. It is intended to be maintained in a state of no play.

After the focus adjustment is completed, the set screw 308 is further screwed in to increase the axial component force P and the axis orthogonal component force P2, thereby ensuring that the imaging lens 5 does not shift relative to the lens holder 301. At the same time, rotation of the focus adjustment shaft 306 is stopped.

Next, regarding the CCD2 position adjustment mechanism, see Figures 3 and 4.
The explanation will be given based on FIG. 5, FIG. 12, FIG. 18, and FIG. 19.

First, in the tilt adjustment mechanism for the inclination of the CCD 2 in the X-axis direction, which is the main scanning direction, that is, the rotational fine adjustment around the Y-axis α! As mentioned above, the COD unit 20 having the metal plate 21 that holds the CCD 2 at a fixed reference position is mounted on two circular pedestals 31d formed on the upper surface of the channel 31 corresponding to the two reference mounting holes 21e. screw pin 3
It is fixed by placing 2 in one place. As a result, the CCD 2 can be easily replaced within a positional deviation range of 200 to 300 μm.

The COD control board PCB-122 is positioned so as to protrude downward from a rectangular mounting hole 31a formed in the channel 31.

A substantially cylindrical horizontal shaft 33 is attached to the lower surface side of the right end portion of the channel 31 in the X-axis direction in FIG. 12 so as to extend in the Y-axis direction. This horizontal axis 33 is
Both end portions are cut out into a substantially semi-cylindrical shape, and the plane portions of the semi-cylindrical cut-out portions 33C are brought into contact with the lower surface side of the channel 31 and fixed by countersunk screws 34.

Further, two conical portions 33a are formed at the center of the horizontal shaft 33 so as to face each other.

Both of these conical portions 33a are accommodated within a rectangular cutout portion 31c formed in the channel 31. On the other hand, on the upper surface side of the right end portion of the movable base plate 50 in the X-axis direction in FIG. 12, a vertical shaft 35 is provided upright in the Z-axis direction (optical axis direction). The lower outer peripheral edge of the cylindrical portion 35a is in contact with the conical inclined side surfaces of two conical portions 33a formed on the horizontal shaft 33. As a result, the entire channel 31 including the CCD unit 20 can be rotated about the horizontal axis 33 and the vertical axis 35.

A square bar 38 is fastened to the left end portion of the channel 31 in the X-axis direction in FIG. They are screwed together. This adjustment screw 39 is
It protrudes downward through a large diameter hole (not shown) formed in the channel 31, and its spherical tip portion 3
9a is the upper surface 50i of the movable base plate 50 having a U-shaped cross section.
is in contact with.

On the other hand, stepped pins 36a and 36b are provided on the front wall 31e and rear wall 31f of the channel 31 in the Y-axis direction.
are respectively screwed in the vicinity of the square rod 38, and the upper ends of tension springs 37a and 37b are hung on these stepped pins 36a and 36b, respectively. The lower ends of the tension springs 37a and 37b are hung on stepped pins 54a and 54b, respectively, which are screwed onto the front wall 50g and rear wall 50h of the movable base plate 5o. These tension springs 37a and 37b
is extended obliquely to form approximately 456 angles with respect to the two axes (optical axes), and due to its tensile force, the
A component force is generated inside the vicinity that presses the channel 31 downward and to the right in FIG. Then, due to the rightward suppressing force by the tension springs 37a and 37b, the lower outer peripheral edge 35a of the cylindrical portion of the vertical shaft 35 is moved into the conical shape of the two conical portions 33a formed on the horizontal shaft 33. At the same time as being pressed against the inclined side surface,
The lower surfaces of the cylindrical portions 33b on both end sides of the horizontal #I33 are brought into pressure contact with the upper surface 50a of the movable base plate 50 by the downward suppressing force exerted by the tension springs 37a and 37b. As a result, the entire channel 31 including the CCD unit 20 is held in a three-point supported state by the vertical shaft 35 and the movable base plate 5o via the horizontal shaft 33. Further, due to the downward suppressing force by the tension springs 37a and 37b, the spherical tip portion 39a of the adjusting screw 39 screwed onto the square rod 38 is pushed onto the upper surface of the movable base plate 50.
It is designed to be pressed against 0i. Therefore, by rotating the adjusting screw 39, the channel 31 is adjusted to the horizontal axis 3.
It is rotated around the Y axis, that is, in the α direction, and positioned.

At this time, the stepped pins 36a and 36b are connected to the horizontal axis 3.
3 and the adjustment screw 39, and the adjustment screw 39
, the lower surfaces of the cylindrical portions 33b on both end sides of the horizontal shaft 33 are urged to be more strongly pressed against the upper surface 50a of the movable base plate 5o, and the two are interposed between each other. It is designed to be closely attached without any problem. Further, the biasing force of the stepped pins 36a and 36b is set to such an extent that the channel 31 is not prevented from rotating around the vertical axis 35.

Furthermore, a spring hook portion 38g is formed to protrude from the left end portion of the channel 31 in the X-axis direction in FIG. It is being On the other hand, a square bar 51 is screwed and fixed to the side surface of the movable base plate 50, and the other end of the tension spring 40 is hung on a stepped pin 52 provided upright on the square bar 51. ing.

Due to the biasing force of the tension spring 40, the channel 31
The whole can be rotated toward the front about a vertical axis 35. Also, the screw hole 5 provided in the square bar 51
An adjusting screw 53 is screwed into 1a, and the spherical tip portion 53a of this A adjusting screw 53 is connected to the Y of the channel 31.
It is in contact with the hand side wall surface 31e in the axial direction. Therefore, by rotating the adjustment screw 53, the channel 3
1 is rotated about the vertical axis 35 around the Z axis, that is, in the γ direction, and is positioned.

The fine adjustment mechanism having such a configuration allows fine adjustment of the inclination in the X-axis direction, which is the main scanning direction, that is, the rotational fine adjustment in the α direction around the Y-axis, and the rotational fine adjustment in the α direction, which is the optical axis direction of the imaging lens 5.
Fine rotational adjustment of the direction is performed accurately. That is, by first rotating the adjustment screw 39, the tension spring 37a
, 37b, the channel 31 is rotated about the horizontal axis 33, thereby positioning the CCD 2 in the α inclination direction. At this time, since the rotation center position and the adjustment action position are separated from each other, fine adjustments can be made without using a complicated mechanism such as a differential screw. Naoko! l! I setting screw 3
9, the spherical tip portion 53 of the adjustment screw 53 is placed on the front wall surface 31e of the channel 31 in the Y-axis direction.
a is kept in contact with the channel 31, but since the perpendicularity of the front side wall surface 31e of the channel 31 to the horizontal axis 33 is maintained at the required precision, the channel 31 is vertically moved by the above-mentioned sliding movement. It is hardly rotated around the shaft 35 and there is no problem in adjustment. Moreover, the horizontal axis 33 is CC
Since it is provided at a position sufficiently spaced from D2, C0D2 is hardly displaced in the X-axis direction, which is the main scanning direction, when adjusting the CCD 2 in the α inclination direction.

- By rotating the force adjustment screw 53, the channel 31 is rotated around the vertical axis 35 in the γ direction around the Z axis against the tension spring 4o to perform positioning, and the exposure shown in FIG. The parallelism of the pixel row of the CCD 2 with respect to the line 13 is adjusted. Even in this case, since the rotation center position and the adjustment position are spaced apart, fine adjustment can be made without using a complicated mechanism such as a differential screw. Note that when adjusting the rotation with this adjustment screw 53, the upper surface 50 of the movable base plate 50
The spherical tip portion 53a of the adjustment screw 39 is slid on the top surface 50a of the movable base plate 50 while being in contact with the cylindrical portion 33b of the horizontal shaft 33. However, since the perpendicularity of the upper surfaces 50i and 50a of the movable base plate 50 to the vertical axis 35 is maintained at the required precision, the channel 31 is rotated around the horizontal axis 33 by the above sliding movement. There is almost no problem with adjustment. Moreover, since the vertical axis 35 is provided at a position that is fully visible from C0D2, when adjusting the CCD 2 in the γ direction around the Z axis, the vertical axis 35 is
CD2 is almost never misaligned.

Next, position adjustment of the CCD 2 in the Y-axis direction, which is the sub-scanning direction, and the X-axis direction, which is the main scanning direction, will be explained.

Square rods 56.57 are attached to the rear wall 50h of the movable base plate 50 in the Y-axis direction, and adjustment screws 56.58 are screwed onto these square rods 55.57. Upper v2: The tip portions of the Ag1 screws 56 and 58 are formed into a spherical shape, and the spherical tip portions are in contact with the front wall 80c of the rotating base plate 80.

On the other hand, the right side wall 50d of the movable base plate 50 in the X-axis direction
Fitting holes 50f are formed through the left side wall 50e, and each of these fitting holes 50f is connected to a support shaft 64 extending between a right boss 81 and a left boss 82, which will be described later. It is fitted so that it can slide and rotate freely. Further, as shown in FIG. 4 in particular, L-shaped plates 59 and 60 are provided on the upper sides of the right side In 50 d and the left side wall 50 e.
are each screwed on. These L-shaped plates 59
Holes 59a and 6 formed at the tips of and 60
One ends of tension springs 61a and 61b are attached to Oa. Further, as shown in FIGS. 3 and 4, a right lever 62 and a left lever 63 are rotatably mounted on the support shaft 64. Above right lever 6
2 and the left lever 63 are formed with fitting holes G2a and G3a, and these fitting holes 62a and 63a are adapted to be attached to the support shaft 64. Right lever 62
The left lever 63 is arranged on the outside of the right side wall 50d and the left side wall 50e of the movable base plate 50, respectively, and the elongated holes 6 formed in the upper arm parts 62d and 63d thereof
By engaging locking screws 68 and 69 in 2e and 63e, rotation of right lever 62 and left lever 63 with respect to support shaft 64 is restrained, respectively. The locking screws 68 and 69 are screwed into the right side wall 80a and the left side wall 80b of the rotating table plate 80, respectively, so as to penetrate in the X-axis direction.

Further, holes 62c and 63c are formed in the middle arm portions 62b and G3b extending in a direction perpendicular to the upper arm portions 62d and 63d, that is, toward the front wall 80c of the rotating base plate 8o, and these holes 132c and One ends of the aforementioned tension springs 61a and 61b are hung on 63c.

In the state shown in FIG. 4, the tension spring 61a
and 61b are energized.

The movable base plate 50 attempts to rotate in the fourth clockwise direction due to the urging force of the tension springs 61a and 61b, but the spherical tip portions 56a and 58a of the adjustment screws 56. It is designed to be stopped by being pressed against it. The tension spring 61a is extended so that its biasing force generates component forces in the tangential direction and the normal direction around the support shaft 64, whereby the movable base plate 50 is urged against the support shaft 64. , will be held in a fixed position.

Further, as shown in FIG. 6, a lower arm portion 62f is formed below the right lever 62, and a bent portion provided on the lower arm portion 62f forms the right side wall 50d of the movable base plate 50.
is in contact with the lower edge of the

When the CCD unit 20 is rotated toward the front to the state shown in FIG. 6 for maintenance or replacement, the tension spring 61a, which is in a predetermined deenergized state, is held so as not to fall off. It has become so. Further, around the fitting holes 62a and 63a formed in the right lever 62 and the left lever 63, circular arc holes 62g, G2h and 63g, 63h are provided so as to face each other, and one of the circular arc holes 62g and 63
An adjustment screw 83 is passed through g in a non-contact manner, and a locking screw 73 is loosely fitted into the other arcuate hole G2h and 6311.

The fine adjustment device having such a configuration allows accurate position movement fine adjustment in the Y-axis direction, which is the sub-scanning direction. That is, by rotating the adjusting screws 5G and 58, the movable base plate 50 is rotated about the support shaft 64 against the tension springs 61a and Glb, thereby determining the position V:1 of the CCD 2 in the Y-axis direction. It is supposed to be done. At this time, since the rotation center position and the adjustment action position are spaced apart from each other compared to the distance between the rotation center position and the CCD 2, fine adjustments can be made without using a complicated mechanism such as a differential screw. be able to. Note that this adjustment screw 5
The movement adjustment operation in the sub-scanning direction according to 6.58 is performed by a rotational movement around the support shaft 64, but the CCD 2 is arranged at a distance from the support shaft 64, and the amount of movement for position adjustment is Since C is 1 to 2 am, C
There is no problem because the deviation in the inclination β direction of the CD 2 in the sub-scanning direction is extremely small. Further, when a linear sensor with extremely small pixel dimensions (7 μm x 7 μm) is used as in this embodiment, the slight inclination β of the pixel row in the sub-scanning direction does not pose any problem in reading the projected image.

Rather, it is preferable to slightly tilt the CCD 2 in the sub-scanning direction with respect to the optical axis, since this prevents the reflected image of the C0D 2 projected by the cover glass 2b from being re-projected onto the pixel row.

Furthermore, the right side u 80 a and 80 of the rotating base plate 80
Fitting holes 81a and 82a are formed through the center portions of the right boss 81 and left boss 82, respectively, which are screwed to b.
Both end portions of the support shaft 64 are fitted into the support shaft 64, and are locked by set screws 81b and 82b. Further, a compression spring 65 is inserted into the support shaft 64 on the outside. One end portion of this compression spring 65 is supported by the inner surface of the right side wall 50d of the movable base plate 5o, and the other end portion of the compression spring 65 is fixed so as to pass through the support shaft 64. The movable base plate 50 is pressed against and locked to the pin 67 via a washer 66, so that the movable base plate 50 is urged toward the right in FIG. 3, that is, toward the right boss 81. On the other hand, an adjustment screw 83 is screwed into the right boss 81 so as to pass therethrough.
It is in contact with 0d. The right side wall 50d of the movable base plate 5o is caused by the moving force of the movable base plate 5o by the compression spring 65.
is pressed against the spherical tip portion 83a of the adjustment screw 83. Therefore, by rotating the adjustment screw 83, the movable base plate 50 is moved in the main scanning direction. The thread pitch of the adjustment screw 83 is 0.51
IIn, and the position of pixel row 2a of CCD 2! l! In order to satisfy the adjustment accuracy of 63.5 .mu.m, it is sufficient to rotate the adjustment screw 83 with an accuracy of about 45 DEG, making the adjustment operation extremely easy. The main scanning direction (X
Axial direction): J! In the 4-alignment operation, the position of the CCD 2 is in the sub-scanning direction (Y-axis direction) and the main-scanning tilt direction (α direction).
, in the direction around the optical axis (γ direction), or in the Z-axis direction. This means that the perpendicularity between the support shaft 64 and the optical axis of the imaging lens 5 is Fj'' with an accuracy of ±1'.
! 1, and the parallelism of the support shaft 64 to the exposure line 13 of the original image is also maintained within an accuracy of ±1', and the movable base plate 50 is configured such that the tension springs 61a and 61b are This is because the movable base plate 50 is pressed in the radial direction of the support shaft 64 by the force, and at the same time, the position of the movable base plate 50 is maintained by the front wall 80c of the rotary base plate 80 via the adjustment screws 56 and 58.

Further, as in this embodiment, the dimensions of the pixel row 2a of the CCD 2 (
35ao), the spindle 64 has a sufficient spacing (180nu
).

The positional accuracy in the sub-scanning direction (Y-axis direction) of the right boss 81 and left boss 82 that support the support shaft 64 is the normal machining accuracy (
For example, about ±0.1nn), the main scanning direction of CCD2
In the sub-scanning direction (
The positional deviation in the Y-axis direction is about 2 μm, and there is no problem with adjustment.

Next, a mechanism for adjusting the perpendicularity of the optical axis of the imaging lens 5 with respect to the original exposure surface shown in FIG. 1, that is, the plane for reading the original 12 with the exposure line 13 will be explained.

As shown in FIG. 3, FIG. 4, and FIG. A hole 96 is formed perpendicular to the axis, and this hole 96
A conical shaft 94 is fitted into the front wall 80c, and the conical shaft 94 is tightened by a cylindrical female screw 95 and fixed at right angles to the front wall 80c. Further, the rotary base plate 80 is arranged so as to face the front wall 100a of the base plate 100, which is formed in a U-shape in cross section. The large-diameter side of the conical shaft 94 passes through the circular arc hole portion 120a of the mating hole 120 (see FIG. 5(b)) and projects inside the base plate 100. At this time, the engagement hole 1
20 circular arc hole portions 120a are formed to be smaller than the maximum diameter of the conical portion of the conical shaft 94 and larger than the minimum diameter, and the conical inclined surface 94a of the conical shaft 94 is formed in the engagement hole 1.
20 is engaged with the circular arc hole portion 120a. This causes the front surface ulo of the base plate 100 to be lowered.

The rotary base plate 80 is rotatable about a conical shaft 94 with respect to a.

On the other hand, the third
A pedestal 101 is welded to the right side of the figure.

An adjustment screw 102 is screwed into a screw hole formed in this pedestal 101 so as to penetrate therethrough.

The spherical tip portion 102a of the adjustment wand 102 is as follows.

It is in contact with the upper surface 90a of a square bar 90 that is welded to the right side u 80a of the rotating base plate 80. Further, a stepped pin 93 is erected on the left side portion of the front wall 100a of the base plate 100 in FIG. 3, and a stepped pin 91 is erected on the left side wall 80b of the rotary base plate 80. A tension spring 92 is stretched between the stepped pins 93 and 91. As a result, the rotating white plate 8
0 is urged to rotate around the third mouth around the conical shaft 94, and the upper surface 90a of the square bar 90 welded to the right side wall 8°a of the rotating base plate 80 is rotated by the adjusting screw 102. It is pressed against the spherical tip portion 102a, and the rotating base plate 8o is stopped.

At this time, the conical shaft 94 is pressed downward perpendicularly to the conical shaft 94, but as described above, the conical inclined surface 94a of the conical shaft 94 By engaging with the conical shaft 94, the conical shaft 94 receives a component force directed to the left in FIG. 5, and this component force presses the rotating base plate 80 toward the base plate 100. Also, the base plate 1
On the front wall 100a of 00, three circular pedestals 100f are formed on the circumference centered on the conical axis 94 at an equal pitch of approximately 120'', and these circular pedestals 100
The outer surface of the front wall 80C of the rotating base plate 80 is brought into contact with the upper surface f, and the rotating base plate 80 is supported at three points, thereby allowing the rotating base plate 80 to rotate stably. There is. Further, on the front surface M 80 c of the rotating base plate 80, three elongated holes 84, 85, 86 are formed at equal intervals of approximately 120° on the circumference around the conical shaft 94. long hole 8
Set screws 8G, 87.degree. 88 passing through holes 4, 85 and 86 are screwed onto the front wall 100a of the base plate 100 to fix the rotating base plate.

Therefore, if the adjusting screw 102 is rotated with the setscrews 86, 87, and 88 loosened, the rotating base plate 8o is rotated about the conical shaft 94, and the base plate 8o is rotated at a right angle to the optical axis of the imaging lens 5. will be adjusted.

In the perpendicularity adjustment operation of the optical axis using the adjustment screw 102, the position of the CCD 2 is adjusted in the main scanning direction (X-axis direction), the sub-scanning direction (Y-axis direction), the main scanning tilt direction (α direction), and the direction around the optical axis. No deviation occurs in either the γ direction or the Z axis direction. Moreover, the three-point support structure of the rotating base plate 80 prevents the rotating base plate 80 from deforming.

In the perpendicularity adjustment mechanism in the sub-scanning direction between the optical axis of the imaging lens 5 and the original image exposure surface, as shown in FIGS. 14, 15 and 16, the base plate 100
is screwed onto the front side wall 200a of the base 200, and three circular pedestals 203 are welded to the front side Q200a, and a left side plate 213 is welded to both left and right end portions of the base Q200a, respectively. The upper left shaft 215 and the right main shaft 217 are attached to the right side plate 216 so that they are coaxially arranged. Two shafts 214 are provided at positions symmetrical to the left main shaft 215 on the left side plate 213 so that they are parallel to the left main shaft 215 and their axes are arranged on the same plane. Further, the left support frame 230 and the right support frame 231, which are provided as immovable members with respect to the original exposure line 13, have a left support frame 230 and a right support frame 231, which support the base 200 rotatably around the left main shaft 215 and the right main shaft 217. The support plate 218 and the right support plate 225 are respectively welded. 6 A recess 218a is formed in the center of the left support plate 218, and the bottom surface 21 of the recess 218a
A bearing portion 218b having an arcuate cross section is recessed in the center portion of 8f. The upper left shaft 21 is attached to this bearing portion 218b.
5 is fitted.

Further, the left main shaft 21 is located at the bottom surface 218f of the recess 218a.
A square bar 219 for positioning 5 is fixed by two setscrews 220. - Grooves 21 on the right and left main shafts 215
5a is formed in an annular shape, and when the square rod 219 is brought into contact with the groove bottom 215b of this annular groove 215a, the upper left shaft 215 is positioned in an immovable state in the left and right main axis direction, that is, the main scanning direction (X-axis direction). It is becoming regulated.

Also, a set screw 22 is screwed onto the square rod 219.
1 is pressed against the groove bottom 215b of the groove 215a.

Further, in the upper and lower end portions of the left support plate 218, there are grooves 318c for accommodating the shaft 214 in a TL-fitted state.
and 218d are recessed, and adjustment screws 222 and 223 are screwed into the upper and lower end portions of the left support plate 218, respectively, so as to press the shaft 214. By rotating the adjustment screws 222 and 223, the left support plate 218 is rotated about both main shafts.

Further, a bearing portion 225a having an arcuate cross section is recessed in the center portion of the right support plate 225.
The upper right shaft 217 is fitted to the 6 and right support plate 22.
5 has a square rod 22 for positioning the upper right shaft 217.
6 is fixed by two set screws 226 , and the tip of the set screw 228 screwed onto the square bar 226 is pressed against the surface of the right main shaft 217 .

In FIG. 15, the optical axis of the imaging lens 5 is the axis 214.
The imaging lens 5 is set parallel to the straight line connecting the axis of the lens and the axis of the upper left axis 215, and extends in the sub-scanning direction through the left main axis 215 and the upper right axis 217.
The optical center of the imaging lens 5 is arranged, and the optical axis position of the imaging lens 5 is arranged near the left and right axes. In such a configuration, if the adjustment screws 222 and 223 are rotated.

The optical axis of the imaging lens 5 is rotated integrally with the base 200,
The inclination in the sub-scanning direction (Y-axis direction) will be finely adjusted. As a result, the angle between the optical axis of the imaging lens 5 and the exposure surface of the document in the sub-scanning direction is finely adjusted. In such an adjustment operation, the imaging lens 5 does not shift in the main scanning direction (X-axis direction) or in the inclination direction (α direction) of the main scanning direction. Further, after adjusting the inclination of the optical axis of the imaging lens 5 in the sub-scanning direction, the upper screw 22
1.228 and adjustment screws 222, 223, the base 200 is fixed in position, and therefore the position of the imaging lens 5 is fixed.

Next, lens unit 3oO and CCD unit 2o
The mechanism for adjusting the movement of the lens in the optical axis direction will be described below.

Next, the lens unit 300 and the CCD unit 2o
The mechanism for adjusting the movement of the lens in the optical axis direction will be described below.

In FIGS. 1, 2, 3, 4, and 14, the left support frame 230 and the right support frame 230 are provided as immovable members with respect to the exposure line 13 of the original image, as described above. With respect to the frame 231, the base 200 is aligned with the exposure line 1.
A left main shaft 215 and a right main shaft 2 which are parallel to and coaxial with 3.
This base 20 is rotatably supported by a base 17.
Fitting holes 2 are provided in the upper wall 200b and lower wall 200C of 0.
01 and 202 are formed so as to face each other. In these fitting holes 201 and 202.

The support shaft 113 is fitted into the upper left shaft 231 and the right main shaft 217 so as to be perpendicular to both axes. On the other hand, the base plate 100
In the upper wall 100b and the lower wall 100c, elongated holes 111° and 112, which extend in the sub-scanning direction, are formed at positions corresponding to the refitting holes 201 and 202, respectively.
Both upper and lower end portions of the support shaft 113 are fitted into these elongated holes 111 and 112. Also, the above support N 11
The upper wall 100b and lower side a1o of the upper plate 100 of No. 3.

Retaining rings 114 are respectively locked on the upper and lower sides of C, thereby securing the support shaft 11 together with the base plate 100.
3 is supported so as to be slidable in the optical axis direction of the imaging lens 5. At this time, the base plate 100 is moved in the sub-scanning direction (Y
can be moved in the axial direction).

In addition, it remains immobile in the main scanning direction (XII11 direction).

Furthermore, of the three circular pedestals 203 that are welded to the front wall 200a of the base 200, two of the circular pedestals 203 are placed apart from each other by a predetermined distance on a line parallel to the axis of the support shaft 113. and the remaining one circular pedestal 20
3 is arranged on a line parallel to the axes of the left main shaft 215 and right main shaft 217. The surface portions of these three circular pedestals 203 are formed so as to be arranged in the same plane, and are each formed with a female thread portion 203b that allows a screw 104 (to be described later) to 3M. On the other hand, in the front wall 100a of the base plate 100, there are three vertically long elongated holes 103 at positions corresponding to the three circular pedestals 203.
The screws 104 pass through each of these elongated holes 103. A compression spring 10G is attached to the outside of the screw 104, and this compression spring 106
A tube 105 is attached to the outside of the tube. compression spring 106
One end portion of the compression spring 106 is pressed against the screw head of the screw 104 through a washer 107, and the other end portion of the compression spring 106 is pressed against the base plate 100 through a washer 108. As a result, the base plate 100 is pressed toward the circular base 203, and the base plate 100 is moved along the support shaft 113 while being pressed against the circular base 203 by the urging force of the compression springs 106 at three locations. It is made slidable in the direction of the lens optical axis. At this time, the base plate 100 remains stationary in the sub-scanning direction.

Further, a square rod 109 is screwed to the right end of the upper u1oob of the base plate 100 near the support shaft 113, and an adjustment screw 110 is screwed to pass through the square rod 109. Spherical tip portion 11 of the adjustment screw 110
0a passes through a large diameter hole (not shown) formed in the base plate 10 and abuts on the upper wall 200b of the base 200.

In this embodiment, one base plate 100, a rotary base plate 80 attached thereto, a lens unit 1-300, a CCD unit 20 .
The force that presses and slides the base plate 100 downward along the support shaft 113 due to the weight of the CCD base plate unit 30, the support shaft 64, etc. is applied to the base plate 100 by the pressure of the three compression springs 106.
The friction resistance force between the front wall 100a of the circular base 203 and the front surface 203a of the circular pedestal 203 is larger than that of the front wall 100a of the circular base 203.
In particular, no spring is used to press and bias the base plate 100 downward. However, if necessary, for example, the lower side u of the base plate 100
It is also possible to arrange a compression spring to be inserted into the support shaft 113 between lOc)c and the lower side 'I-200c of the base 200.

In such a configuration, by rotating the adjustment screw 110, the base plate 100 is finely adjusted and moved along the support shaft 113 while in contact with the circular base 203. Therefore, by moving the adjusting screw 110 back and forth, the lens unit 1-300 and the CCD unit 20 can be finely adjusted in the direction of the lens optical axis without causing any mutual positional deviation. As a result, fine adjustment of the distance between the exposure line 13 and the CCD 2, that is, the conjugate length (L in FIG. 2) at a predetermined projection magnification, can be easily and accurately performed. Moreover, during such adjustment, the imaging lens 5 and CCD 2 are adjusted in the main scanning direction (X-axis direction), sub-scanning direction (Y-axis direction), rotation direction around the lens optical axis (γ direction), and main scanning direction (X-axis direction), sub-scanning direction (Y-axis direction), Tilt direction of scanning direction (
There is no deviation in the direction of inclination (β direction) in the sub-scanning direction or the α direction.

Next, the light shielding and dustproof seal structure of the CCD 2 will be explained.

In FIGS. 3 and 5, lens 221-300
A seal body 3 is attached to the lower part 301d of the lens holder 301.
To 10 [? The fixed upper plate 311 is joined by hχ. The upper plate 311 is formed with a bent portion 311a for positioning in the main scanning direction and the sub-scanning direction. On the other hand, the lower side of the seal body 310 is adhered to the lower plate 312.

This lower plate 312 is formed with a notch 312a that engages with two countersunk screw pins 32 that screw the CCD unit I-20 into the channel 31. The seal body 310 is
The lens holder 301 and the metal plate 21 that adhesively hold the CCD 2 are mounted and positioned so as to shield the peripheral area outside the imaging optical path formed by the imaging lens 5.

The seal body 310 is made of a soft foamed resin having fine mesh and light-shielding properties and air permeability formed into a rectangular tube shape, and its elastic force allows the lens holder 301 and the metal plate 2 to be attached to each other.
1 through an upper plate 311 and a lower plate 312.

No gaps are formed between the upper plate 311 and the lens holder 301 and between the lower plate 312 and the metal plate 21. With such a seal body 310, the CCD 2
External light that would degrade the image reading signal is blocked, and the adhesion of dirt, dust, etc. to the CCD 2 is prevented.

Further, the sealing body 310 is made of a material and having a shape and dimensions that do not impair air permeability, so that the image reading function of the CCD 2 is sufficiently prevented from being inhibited or deteriorated. Furthermore, the hardness and size of the seal body 310 are such that the lens holder 301 or the metal plate 21 will not be deformed or misaligned with each other due to the elastic force of the seal body 310, and the lens holder 301 and the metal plate It is set to such an extent that it is possible to separate from between 21 and 21. Therefore, the sealing body 310 in which the upper plate 311 and the lower plate 312 are vertically bonded can be easily attached and detached between the lens holder 301 and the metal plate 21, and the upper plate 31
1 and the lower plate 312, the mounting position of the metal plate 21 does not shift when adjusting the position of the metal plate 21 relative to the lens holder 301, and the flexibility of the seal body 301 prevents the lens from shifting. This prevents excessive force from being applied to the holder 301 and the metal plate 21.

In the cooling device shown in FIG.
6, the air is filtered by a dust filter 208 attached to the duct I/207 to remove dirt and dust, and then flows into the base 200 through the square hole 205 of the base 200. The seal body 31 passes through the square hole 100g of the base plate 100 and the square hole 80e of the rotating base plate 80.
0, it is designed to be sprayed towards the lower part of CCD 2 and PCB-122. The blowing action of the air blower 1f120G is controlled based on a temperature detection signal from the CCD 2 emitted from the thermistor 25 that is in contact with and adhered to the back surface of the C0D2.

With such a cooling device for the CCD unit 2o, C
This prevents expansion and deformation of the CCD2 due to heat generated from the 0D2 itself or the PCB-122 soldered to the CCD2, thereby preventing image reading abnormalities and preventing the electronic components on the PCB-122 from occurring. Malfunctions due to heat generation are also prevented.

Although the CCD 2 installed in the document reading device is designed to prevent dust such as dust from adhering to the surface of the cover glass 2b, it may interfere with normal reading during long-term use. Since dirt and dust may adhere to the surface, it is desirable to clean it as necessary. Furthermore, it is desirable that the CCD 2 be constructed so that it can be easily replaced if it breaks down or its performance deteriorates for some reason.

Therefore, in this embodiment, the mounting member of the CCD 2 is made rotatable in the sub-scanning direction.

A configuration is adopted in which the CCD 2 is retracted out of the imaging optical path in the form of a CCD unit 2o that is integrally formed with a metal plate 21 that is a holding member thereof, thereby facilitating attachment and detachment to the member. 6. When simply cleaning the C0D 2 without replacing it, the CCD unit 20 is configured to expose the CCD unit 20 at an angle to the front, making the cleaning operation extremely easy. Furthermore, even when the CCD unit 20 is replaced, the CC
The position of the D2 mounting member is configured to be accurately returned to its original position by the adjustment screw and spring bias, and fine adjustments due to dimensional variations in the CCD unit h20 can be made easily (a). It is structured so that it can be done.

That is, as shown in FIGS. 3, 4, and 6, the tip of the screw 68 screwed into the right side wall 80a of the rotating base plate 80 is connected to the upper arm 62d of the right lever 62. Although the right lever 62 is retracted to the position where it is removed from the elongated hole G2e, the right lever 62 is rotated around the sixth opening around the support shaft 64 by the biasing force of the tension spring 61a, so that the right lever 62 The bent portion of the lower arm portion 62f of the movable base plate 5o is brought into contact with the lower edge of the right side wall 50d of the movable base plate 5o.

By tightening the lever 4, the relative positions of the movable base plate 50 and the right lever 62 around the support shaft 64 are brought into a stable state. Similarly, the screw 69 screwed into the left side wall 80b is removed from the elongated hole 63e of the upper arm <33d of the left lever 63, so that the bent portion of the lower arm 63f of the left lever 63 is attached to the movable base plate 50. The left side (:J, 50c) is brought into contact with the lower bulge of the lever, and the relative positions of the movable base plate 50 and the left lever 63 around the support shaft 64 are maintained at a stable distance of 1 m.

In this state, as shown in FIG.
The movable base plate 50 with the D unit 20 attached is attached to the right lever 6
2. It can be rotated integrally with the left lever 63 to the outside of the projection optical path of the imaging lens 5, but the range of rotation is limited to the screws 73 screwed into the right boss 81 and the left boss 82, respectively. and 74, the circular arc hole G of the right lever 62
21 and one end of the arcuate hole G 3 h of the left lever G3 are brought into contact with each other, thereby being regulated. In this state, the CCD unit 20 is exposed at the front of the apparatus, and cleaning of the CCD 2, replacement, and attachment/detachment of the CCD unit 20 can be easily performed. The arcuate hole 6 of the right lever 62 is connected to the adjustment screw 83 which cooperates with the compression spring 65 to position the movable base plate 50 with the
The position and size of the arcuate hole 62g are set so that the screw 2K does not come into contact with the adjustment screw 83, thereby preventing it from being displaced or deformed due to excessive force being applied to the adjustment screw 83. It looks like this. At this time, the CC is held so that its position can be adjusted with respect to the movable base plate 50.
Holding member of D unit 1-20 (channel 3 in Figure 3)
1) is maintained completely unchanged with respect to the movable base plate 50.

After completing the necessary work such as cleaning and replacing the CG, D2, and CCD units 20, the movable base plate 50 is rotated back to its original position. That is, if the right lever 62 and the left lever 63 are respectively locked in predetermined positions by the screws 68 and 69, the tension springs 6La,
The movable base plate 50 is rotated around the support shaft 64 by the biasing force of the movable base plate 61b. 50 is adapted to be returned to its original position in a state where it is accurately positioned. Also at this time, the movable base plate 5
The right side wall Sod of 0 is also brought into contact with the adjustment screw 83 at its original position, and the position in the main scanning direction is also accurately restored to its original position.
It is now possible to do so.

In the image reading device according to the embodiment of the present invention, a position adjustment mechanism that uses the steps of a screw is employed to adjust the position of the CCD with respect to the imaging lens, and the position of the imaging lens 5 and CCD 2 with respect to the original image exposure surface. There is. That is, in this embodiment, a means for pressing the male thread and the female thread in the radial direction is used in order to prevent problems in fine adjustment due to play in the axial and radial directions of the screw.

As shown in FIGS. 17 and 18, the square bar 3
8 and the movable base plate 50 are urged toward each other by a tension spring or gravity, and the female thread 38a formed on the square bar 38 has a thread 38a.
An A adjustment screw 39 is screwed together, and a hemispherical tip portion 39a of this adjustment screw 39 is in contact with the upper surface 50i of the movable base plate 5o.

The mutual positions of the square rod 38 and the movable base plate 50 are determined by the cooperation of tension springs or gravity. Also, a female thread 38 formed on the square bar 38
A female thread 73 is formed in a direction perpendicular to the screw axis of a, and has a diameter equal to or slightly smaller than the root diameter of this female screw 73, and a length approximately equal to the root diameter of the female screw 73. A cylindrical brake 71 made of nylon is inserted into the female thread 73 by 11x. Further, a set screw 72 is screwed into the female thread 73 from behind the brake element 71, and a planar tip 72a of the set screw 72 suppresses the brake element 71.

The planar tip 72a of the set screw 72 is connected to the brake member 71.
When the set screw 72 is screwed in more strongly from the state in which it is in contact with the nylon brake element 71, the tip part of the nylon brake 71 is pressed against the adjustment screw 39 while being compressed and deformed, and the tip part 71a of the brake element 71 is pressed against the adjustment screw 39. 39, and the peripheral surface 71b of this brake 71 in contact with the female thread 73 also undergoes plastic deformation so as to bite into the thread ridges and valleys of the female thread 73. Become. In this state, the male thread of the adjusting screw 39 will suppress the female thread 38a in the radial direction, and the axial center of the adjusting screw 39 will be maintained in a state slightly deviated from the axial center of the female thread 38a, and the white body of the adjusting screw 39 will be The shaft center position is rotated without shifting due to the rotation of . Therefore, the tip 39a of the adjustment screw 39 is
It is not moved in the radial direction of the screw. When rotating the adjusting screw 39 which has a male thread that engages with the female thread 38a, the square rod 38 and the movable base plate 5 change depending on the step of the adjusting screw 39.
0 will be adjusted, but at that time, due to the play in the engagement between the adjustment screw 39 and the female screw 38a, the tip portion 39a of the A adjustment screw 39 comes into contact with the upper surface 50i of the movable base plate 50. It is designed so that it will not move out of position.

Furthermore, when the nylon brake 71 is plastically deformed as described above, elastic stress is generated in itself, so the brake 71
1 and the setscrew 72 are prevented from unintentionally loosening. Further, the braking force applied to the adjusting screw 39 by the pressing force of the brake element 71 does not change regardless of whether the adjusting screw advances or retreats, and can be further adjusted as necessary.

In such a configuration, after the relative position between the movable base plate 50 and the square bar 38 is adjusted by moving the adjusting screw 39 back and forth, the set screw 72 is further screwed in, thereby further suppressing and deforming the brake element 71. Adjustment screw 39 is female thread 38
It is immovably locked with respect to a. In this case, the adjustment screw 39 will not be displaced from the female thread 38a by screwing in the set screw 72. Therefore 1ffi screw 39
No other fastening means are required to lock the to the female thread 38a.

If the adjusting screw 39 has been rotated for some reason and it becomes necessary to readjust the mutual positions of the movable base plate 50 and the square bar 38, loosen the set screw 72 slightly and adjust the position of the brake 71 relative to the adjusting screw 39. Reduce the pressing force. By doing this, the adjusting screw 39 is rotated with its axial center position maintained at a predetermined position by the required suppressing force, and there is no damage to the threaded portion of the adjusting screw 39. Also, no indentation is caused, and therefore the smooth rotation of the adjusting screw 39 is not hindered in any way.

The position adjustment device constituted by such adjustment screw 39, square rod 38, upper surface 50i of movable base plate 50, brake 71 and set screw 72 is similar to other position adjustment devices, namely:
It is similarly adopted in a position adjustment device using A setting screws 53.5G, 58°102.110.83.6 [Effects of the Invention] As described above, according to the present invention, the focal length of the imaging lens The distance between the original image exposure surface and the COD can be easily and sensitively adjusted against variations in gm, and the projection magnification in each divided reading section can be made to match accurately.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view showing the main parts of the optical system of an apparatus in an embodiment of the present invention, and Fig. 2 shows a set of imaging lenses and C
FIG. 3 is an explanatory front view showing a set of CCD reading units, and FIGS. 4 and 5 (a) show the CCD shown in FIG. 3. FIG. 5(b) is a front explanatory view showing the shape of the hole provided in the plywood, and FIG. C
FIG. 7 is a plan view showing the positioning and fixing structure of the CCD, and FIG. 8 is a cross-sectional view taken along line A-A' in FIG. 7. 9 is an explanatory plan view showing another embodiment of the COD positioning and fixing structure, FIG. 10 is an explanatory cross-sectional view taken along line B-I3' in FIG. 9, and FIG. 11 is an explanatory plan view of the COD positioning and fixing structure.
Fig. 12 is an exploded perspective view showing a CCD fine adjustment structure, and Fig. 13 is an imaging lens focal point 311 mounting structure. FIG. 14 is a front explanatory view showing the reading unit shown in FIG. 3 removed from the base, and FIG. A cross-sectional explanatory diagram along FIG. 16 is B-I3 in FIG. 14.
FIGS. 17 and 18 are cross-sectional explanatory views taken along line 1 and 2, respectively, and are cross-sectional explanatory views showing the locking structure of the adjustment screw. 1.2.3...CCD, 4,5. G...Imaging lens, 12...Original, 13...Exposure line, 15...Reading unit, 20...CCD unit, 64...Spindle, 50...Movable base plate, 8o ... Rotating base plate, 94.
... Conical shaft, 100 ... Base plate, 200 ... Base, 21
5,217...Main shaft, 230,231...Support frame. (Other names) Shape q Figure knee β Shape 40 mouth 9- 17 Figure I'f56 Square shape 140? Fukui Iσ figure 4υ long Ie circle

Claims (3)

[Claims] 1. A position adjustment mechanism for an image reading device that projects an original image onto a photoelectric conversion element using an imaging lens and moves the original image and the photoelectric conversion element relative to each other in a sub-scanning direction to photoelectrically read the original image. , a rotary base that supports a movable base plate that holds the photoelectric conversion element so as to be movable in the main scanning direction, and also supports a lens support member that holds an imaging lens so that it can rotate around an axis in a direction perpendicular to the optical axis. a base that is immovable in the main scanning direction with respect to the document reading position; and a support shaft that holds the rotating base plate movably at least in the lens optical axis direction with respect to the base. A position adjustment mechanism for an image reading device, comprising: 2. In the position adjustment mechanism for an image reading device according to claim 1, the lens support member that holds the imaging lens is positioned between the front principal point and the rear principal point of the imaging lens with respect to the rotating base plate. Position adjustment of an image reading device, characterized in that the image reading device is supported rotatably around an axis in the sub-scanning direction of the photoelectric conversion element and perpendicular to the optical axis of the imaging lens at or near the optical center. mechanism. 3. The position adjustment mechanism for an image reading device according to claim 1, further comprising means for pressing and biasing a member holding the rotating base plate against the base, a member holding the rotating base plate, and the base. 1. A position adjustment mechanism for an image reading device, comprising means for fastening the two.