JPH033560A - Position adjustment mechanism for picture reader - Google Patents

Abstract

PURPOSE:To adjust the orthogonality between an original picture face and the optical axis of an image forming lens with high accuracy by mounting a rotary base plate supporting a lens support member turnably in a direction orthogonal to the optical axis around a support shaft prolonged in a direction orthogonal to the lens optical axis turnably. CONSTITUTION:A rotary base plate 50 supporting a photoelectric conversion element (CCD) 2 and a lens support member 301 supporting an image forming lens 5 to the optical center or its vicinity are moved and adjusted integrally in the subscanning direction and turned integrally at the optical center or its vicinity between a front main point and a rear main point of the image forming lens. Thus, the squareness between the optical axis of the image forming lens 5 and the main scanning direction of an original picture exposure face is adjusted minutely without causing a deviation to the relative position between the CCD 2 and the image forming lens 5. Thus, the production of deviation in the magnification of the formed picture in the main scanning direction or defocus of one focal point is prevented.

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 target manuscript size is 841mm (JISAO size) to 3mm in width.
Some are larger, such as 6# (941g+) (ANSI E size). For such large documents, one photoelectric conversion element (hereinafter referred to as CCD) is required.
It is impossible to reduce and project an image and read it, and conventional reading devices for general office use cannot read with sufficient image 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 COD perfectly matches the width direction of the original image, but also the respective CODs 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 COD 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. .

Conventionally, JP-A-51-51217, JP-A-59-
Various CCD support structures have been proposed in Japanese Patent Application Laid-open No. 201572, Japanese Patent Application Laid-open No. 59-201575, Japanese Patent Application Laid-Open No. 62-277852, and Japanese Patent Application Laid-Open No. 62-89916, but none of them have been proposed. Technology to adjust the perpendicularity between the original image and the optical axis of the imaging lens, technology to adjust the parallelism of the CCD pixel row to the optical axis of the imaging lens, and technology to eliminate the difference in level between multiple CCDs arranged in parallel. has not been disclosed and does not fully meet the above requirements.

The present invention makes it possible to adjust the orthogonality between the original image plane and the optical axis of the imaging lens with high precision, and to align the pixel row of the CCD with the original image exposure surface when finely adjusting the position of the CCD. It is an object of the present invention to provide a position adjustment mechanism for an image reading device that can maintain high accuracy.

[Means for Solving the Problems] In order to achieve the above object, the present invention projects an original image onto a photoelectric conversion element using an imaging lens, and also moves the original image and the photoelectric conversion element relative to each other in the sub-scanning direction. In the position adjustment mechanism of the image reading device, the movable base plate holding the photoelectric conversion element is movably supported in the main scanning direction, and the imaging lens is positioned at the optical center or A rotating base plate that rotatably supports a lens support member held in the vicinity thereof, and a photoelectric conversion element at or near the optical center between the front principal point and the rear principal point of the imaging lens. a supporting shaft that extends in the sub-scanning direction and perpendicular to the optical axis of the imaging lens; and a support that is slidably movable along the axis that extends in the optical axis direction of the imaging lens. The rotating base plate is configured to be rotatably mounted around the support shaft.

[Function] In the means having such a configuration, the movable base plate that holds the photoelectric conversion element and the lens support member that holds the imaging lens at or near the optical center,
They are integrally moved and adjusted in the sub-scanning direction, and integrally rotated at or near the optical center between the front principal point and the rear principal point of the imaging lens.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

As shown in FIG. 1, a document 12 is illuminated by a long illumination lamp 11, and an image on the document 12 is thereby formed in an exposure line 13 by three imaging lenses 4,
5.6, one-dimensional photoelectric conversion device (hereinafter referred to as CCD)
(abbreviated as )) 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 α12 Q1 in the exposure line 13.
0 are overlapped and the CGDI, 2.3
When the read signal is output to a writing device (not shown), control is performed to prevent omissions, duplications, shifts, etc. from occurring at predetermined positions in each overlap area.

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, the area Q2 on the exposure line 13 of the original 12 is
It is reduced by 102 times and is 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 mm. Therefore, the length of the area Q2 is 317.5 m.
m. Here, if the width of the original 12 on the exposure line 13, that is, the maximum reading width Q, is 914.4 mm, the amount of overlap on the exposure line 13 is 0□2-Q
23 is 6.35 nm, and on the pixel row 2a of C0D2, it is 0.7 mm (100 pixels).

In this way, the image of the original 12 is captured by a plurality of CCDs 1.

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 parts of the right side wall 80a and left side wall 80b of the rotating base plate 80. , and a CCD base plate unit 3o which is attached to the support shaft 64 so that it can be rotated and finely adjusted and slidably adjusted in the axial direction.

A CCD unit 2o is held on the CCD base plate unit 3o, and a sealing member 310 having light-shielding properties, dust-proofing properties, and air permeability is installed between the CCD unit 2o 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 a left main shaft 215 and a right main shaft 217. The 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, and the left main axis 215 and the right main axis 217 are in the main scanning direction of the CCD, that is, the exposure direction. It has an axis in a direction parallel to the line 13. Further, two stop shafts 214 are provided on the surface in the direction perpendicular to the axis of the left main shaft 215, and when these stop shafts 214 are tightened or loosened by set screws 222 and 223, the base 200 is fixed. The rotation can be finely adjusted.

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 reference edge 21a and the sub-scanning direction reference edge 2 are connected to the two mounting holes 21e provided in the metal plate 21.
1b and 21c are accurately positioned, so that the pixel column 2a of the CCD 2 is positioned with a predetermined accuracy. At this time, the cover glass 2b of the CCD 2
and the upper surface of the metal plate 21 are positioned on the same plane. Furthermore, in the gap between the ceramic case of the CCD 2 and the positioning hole 21g.

A two-component epoxy resin is injected and hardened to make the CCD 2 immobile.

Further, the CCD control board PCB-122, which includes an amplifying circuit for amplifying the image reading signal from the CCD 2, is connected to the CCD 2.
It is held by soldering to two connecting pins 2c.

There are two connectors 23 on the CCD control board PCB-122.
are soldered, and flat cables 24 made up of a plurality of lead wires are each removably attached. cc
Mounting hole 22a provided on D control board PCB-122
A thermistor 25 for detecting the temperature of the CCD 2 is attached to the holder, and is held in contact with the ceramic case of the CCD 2 by adhesion with an epoxy resin.

Furthermore, the CCD control board PCB-122 has a connector 23.
is soldered, and one end of a flat cable 24 is inserted into this connector 23. The other end 4 of the flat cable 24;! , and is connected to a connector 401 soldered to the CCD control board PCB-2400 (see FIGS. 3 and 5). The above CCD control board PCB-2400 is a CCD
2 constitutes the active motion control circuit, and the CCD
It is larger than the 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 100e extending downward from the base plate 100. By being locked by the screws 404, the COD control board PC
The heat generated by B-122 is prevented from affecting the CCD2.

The CCD control boards PCB- which are spaced apart from each other in this way
122 and the CCD control board PCB-2400 using the flat cable 24, it is conceivable that electrical noise will be picked up through the flat cable 24, making it impossible to output accurate signals corresponding to the original image. However, in this embodiment, as mentioned above, the CCD
The CCD control board PCB-122, which is directly connected to 2, has a read signal amplification function, thereby minimizing the influence of electrical noise. As a result, the flat cable 24 can be lengthened to a certain extent, which alleviates the positional restrictions on the CCD control board PCB-2400, and also allows the CCD 2 to be adjusted in position over a relatively large range without applying undue force to the CCD 2. Flat cable 24 and connector 2 without any load
3,401 can be eliminated.

9 and 10 show other mounting structures for the CCD 2. In other words, at the edge of the positioning hole 21g,
Main scanning direction reference 921a and sub-scanning direction reference 921b
, 21c, there are three reference edges 21f in the optical axis direction, and the 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 CCD 2 remains immovable.

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

Further, FIG. 11 shows another mounting structure for the CCD control board PCB-122. That is, CCD control board P
A socket 26 is connected to the CB-122 via a connecting pin 26a, and a connecting pin 2C of the CCD 2 is inserted into the socket 26. In this way, the CCD 2 can be replaced by inserting the connecting pin 2c of the CCD 2 into the socket 26, or the CC
The D control board PCB-122 can be replaced easily and inexpensively.

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.
e 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 positioned accurately in terms of its surface angle with the holder lower surface portion 301d of the lens holder 301 and the parallelism with the protruding end flat portion 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 conical shaft 94 to the front wall 80c of the rotating base plate 8Q. 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, the movable base plate 5o holding the CCD base plate unit 30 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
After 01d is set parallel to the support shaft 64, it is secured to the rotating base plate 8o 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 against the upper edge of the lens 5, so that 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 mm, is eccentric by 1.5 mo with respect to the axis of the main shaft 306c of the focus adjustment shaft 306, and its length in the axial direction is set to be longer than the depth of the groove 322. . The main axis 306c of the focus adjustment shaft 306 has a diameter of 1211
The eccentric cam 306c is formed in a cylindrical shape of 11.
A conical portion 306d with an apex angle of 90@ is formed on the opposite side of the conical portion 306d, and this conical portion 306d is integrally connected to an auxiliary shaft 306f via a small diameter shaft 306e. The auxiliary shaft 306f is formed to have the same diameter as the main shaft 306c, and a slotted portion 306g into which a driver can be fitted is formed on the end face of the auxiliary shaft 306f. 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. The component forces P and P2 of the pressing force of the pressure rod 307 at these pressure contact points are directed in the axial direction and the direction perpendicular to the axis of the focus adjustment shaft 306, respectively, and the axial component force P□ causes the eccentric cam 306a to The tip surface 306b of 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 306 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 focusing the projected image on the CCD 2 by the imaging lens 5, the frictional force between the lens barrel 321 and the fitting hole 304 is applied to the plate against the lens barrel 321. The set screw 308 is attached to the pressure rod 307 to an extent that the pressing force is not greater than that of the spring 325.
The pressing force from is 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 M image 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 above-mentioned axial component force P1 and axis orthogonal component force P2, thereby ensuring that the imaging lens 5 is not misaligned with respect to the lens holder 301. At the same time, the 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 in the X-axis direction, which is the main scanning direction of the CCD 2, that is, the rotational fine adjustment mechanism around the Y-axis α, and the rotational fine-adjustment mechanism around the Z-axis γ, which is the optical axis direction of the imaging lens 5.
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. It is fixed by screwing in a screw pin 32. This allows CCD
2 can be easily replaced within a positional deviation range of 200 to 300 μm.

The CCD 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 cutout 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, and both of these conical portions 33a are inserted into a rectangular notch 31c formed in the channel 31. is housed in. On the other hand, on the upper surface side of the right end portion in FIG. 12 in the X-axis direction of the movable base plate 50, a vertical axis 3S is erected in the Z-axis direction (optical axis direction).
A cylindrical portion 35a formed at the upper end portion of this vertical shaft 35
The lower outer circumferential edge of is in contact with the conical inclined side surfaces of two conical portions 33a formed on the horizontal shaft 33. As a result, channel 31 including CCD unit 2o
The entire body is rotatable about a horizontal axis 33 and a 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 passes through a large-diameter hole (not shown) formed in the channel 31 and protrudes downward, and its spherical tip portion 39a meets the upper surface 50 of the movable base plate 50 having a U-shaped cross section.
It is in contact with i.

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 screwed onto the front wall 50g and rear wall 50h of the movable base plate 50, respectively. These tension springs 37a and 37b
extends obliquely at an angle of about 45@ with respect to the Z axis (optical axis), and its tensile force causes the square bar 38 to
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 pressing 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 at both ends of the horizontal shaft 33 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 2o connects to the vertical shaft 35 and the movable base plate 5 via the horizontal shaft 33.
0, the three-point support state is maintained. 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 against the upper surface 50 of the movable base plate 50.
It is designed to be pressed against i. Therefore, by rotating the adjustment screw 39, the channel 31 is adjusted to the horizontal axis 33.
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
Since 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 50, the two are separated from each other. It is designed to be closely attached without any problems. 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. The biasing force of the tension spring 40 causes the channel 31 to
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 adjustment screw 53 is screwed into 1a, and a spherical tip portion 53a of this adjustment screw 53 is in contact with the front side wall surface 31a of the channel 31 in the Y-axis direction. Therefore, by rotating the adjustment screw 53, the channel 31
is rotated about the vertical axis 35 around the Z axis, that is, in the γ direction, and 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. Note that when adjusting the inclination using the adjustment screw 39, the spherical tip portion 53a of the adjustment screw 53 is slid while being in contact with the front side wall surface 31a of the channel 31 in the Y-axis direction. Since the perpendicularity of the side wall surface 31e to the horizontal axis 33 is maintained at the required precision, the channel 31 is hardly rotated around the vertical axis 35 by the sliding movement, and there is no problem in adjustment. Further, since the horizontal axis 33 is provided at a position sufficiently apart from the CCD 2, the CCD
2, the CCD 2 is hardly displaced in the X-axis direction, which is the main scanning direction.

- By rotating the force adjustment screw 53, the channel 31 is rotated about the vertical axis 35 in the γ direction around the Z axis against the tension spring 40, and positioning is performed, and the exposure shown in FIG. The parallelism of the C0D2 pixel column 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 5o
The spherical tip portion 53a of the adjustment screw 39 is slid onto the top surface S of the movable base plate 5o while the cylindrical portion 33b of the horizontal shaft 33 is in contact with the upper surface S of the movable base plate 5o.

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 sliding movement allows the channel to be moved. 31 is rarely rotated around the horizontal axis 33, and there is no problem in adjustment. Also, the vertical axis 35
is provided at a position sufficiently apart from the CCD 2, so that the CCD 2 is hardly displaced in the X-axis direction, which is the main scanning direction, when adjusting the CCD 2 in the γ direction around the Z-axis.

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 bars 55 and 57 are attached to the rear wall 50h of the movable base plate 50 in the Y-axis direction, and these square bars 5
5. Adjustment screws 56° and 58 are screwed to 57. Above F1'! The tip portions of the 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 extending between a right boss 81 and a left boss 82, which will be described later.
64 so as to be slidable and rotatable. Further, as particularly shown in FIG. 4, L-shaped plates 59 and 60 are screwed to the upper sides of the right side wall 50d and left side wall 50e, respectively. One ends of tension springs 61a and 61b are attached to holes 59a and 60a formed at the tips of these L-shaped plates 59 and 60. Further, as shown in FIGS. 3 and 4, the support shaft 64 includes a right lever 62 and a left lever 6.
3 is rotatably attached. Fitting holes 62a and 63a are formed in the right lever 62 and left lever 63, and these fitting holes 62a and 63a are connected to the support shaft 6.
It is designed to be installed on 4. The right lever 62 and the left lever 63 are arranged on the outside of the right side wall 50d and the left side wall 50e of the movable base plate 5°, respectively, and are engaged in elongated holes 62e and 63e formed in their upper arm parts 62d and 63d. When the locking screws 68 and 69 are engaged, the support shaft 6 of the right lever 62 and the left lever 63 is
Rotation with respect to 4 is restrained. Note that the locking screws 68 and 69 are attached to the rotating base plate 80.
They are screwed to the right side wall 80a and the left side wall 80b so as to penetrate in the X-axis direction.

In addition, holes 62c and 63c are formed in the middle pile parts 62b and 63b that extend in a direction perpendicular to the upper arm parts 62d and 63d, that is, toward the front wall 80c of the rotating base plate 8o. 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, 62h and 63g, 63h are provided so as to face each other. 62g and 63
An adjustment screw 83 is passed through g in a non-contact manner, and locking screws 73 are loosely fitted into the other arcuate holes 62h and 63h.

The fine adjustment mechanism having such a configuration allows precise position movement fine adjustment in the Y-axis direction, which is the sub-scanning direction. That is, by rotating the adjustment screws 56 and 58, the movable base plate 50 is rotated about the support shaft 64 against the tension springs 61a and 61b, thereby positioning the CCD 2 in the Y-axis direction. It has become. At this time, since the rotation center position and the adjustment action position are separated from each other compared to the distance between the rotation center position and C0D2, fine adjustments can be made without using a complicated mechanism such as a differential screw. be able to. Note that this adjustment screw 56.
The movement adjustment operation in the sub-scanning direction by the CCD 58 is performed by rotational movement around the support shaft 64, but the CCD 2 is
64, and the amount of movement for position adjustment is 1 to 2 mm, the CCD
2, the deviation in the inclination β direction in the sub-scanning direction is extremely small, and there is no problem. 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 projected image by the cover glass 2b of the CCD 2 from being re-projected onto the pixel row.

Further, fitting holes 81a and 82a are formed through the center portions of the right boss 81 and the left boss 82, which are screwed to the right side walls 80a and 80b of the rotating base plate 8o, respectively, and these fitting holes Both end portions of the support shaft 64 are fitted into the holes 81a and 82a, and are locked by set screws 81b and 82b.

Further, a compression spring 65 is fitted to the outside of the support shaft 64 . One end portion of this compression spring 65 is attached to the movable base plate 50.
The compression spring 65 is supported on the inner surface of the right side wall 50d, and the other end portion of the compression spring 65 is pressed into contact with a pin 67 fixed through a support shaft 64 via a washer 66 and locked. As a result, the movable base plate 5o is urged toward the right in FIG. 3, that is, toward the right boss 81. On the other hand, the right boss 81 has an adjustment screw 8.
3 are screwed together so that they pass through, and this adjustment screw 83
The spherical tip portion 83a of is in contact with the right side wall 50d of the movable base plate 50. Movable base plate 5 by the compression spring 65
The right side wall 50d of the movable base plate 50 is brought into pressure contact with the spherical tip portion 83a of the adjustment screw 83 by a moving force of 0. Therefore, by rotating the adjustment screw 83, the movable base plate 50 is moved in the main scanning direction. The screw pitch of the adjustment screw 83 is set to 0.5 m, and the position adjustment accuracy of the pixel row 2a of the CCD 2 is 63.
．． In order to satisfy 5 .mu.m, it is sufficient to rotate the adjustment screw 83 with an accuracy of about 45 degrees, making the adjustment operation extremely easy. This adjustment screw 8
3 in the main scanning direction (X-axis direction) adjustment operation of the CCD 2.

There is no deviation in the position of the CCD 2 in the sub-scanning direction (Y-axis direction), the main-scanning tilt direction (α direction), the direction around the optical axis (γ direction), or the Z-axis direction. This means that the surface angle between the support shaft 64 and the optical axis of the imaging lens 5 is ±1'.
In addition, the parallelism of the support shaft 64 to the exposure line 13 of the original image is also ±1'.
The movable base plate 5o is pressed in the radial direction of the support shaft 64 by the urging force of the tension springs 61a and 61b, and at the same time, the rotation of the rotary base plate 80 is maintained within the accuracy of This is because the position of the movable base plate 50 is maintained by the front wall 80c.

Further, as in this embodiment, the dimensions of the pixel row 2a of the CCD 2 (
35nn), the support shaft 64 has a sufficient interval (180+I
n), the right boss 81 and left boss 82 supporting the support shaft 64 are arranged in the sub-scanning direction (Y
axial direction) position accuracy is normal machining accuracy (e.g. ±O, 1
Even if the amount of position adjustment in the main scanning direction X of the CCD 2 is 2
The positional deviation in the sub-scanning direction (Y-axis direction) with respect to mn is 2μ
m, 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 rotating base plate 8o is disposed so as to face the front wall 100a of the base plate 100, which is formed in a U-shape in cross section, and is connected to the front wall 100a of the base plate 100. 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. As a result, the rotating base plate 80 is
is rotatable about a conical shaft 94.

On the other hand, a pedestal 101 is welded to the front wall 100a of the base plate 100 on the right side in FIG.
An adjustment screw 102 is screwed into the screw hole formed in 1 so as to penetrate therethrough.

The spherical tip portion 102a of the adjustment screw 102 is in contact with the upper surface 90a of the square bar 9o that is welded to the right side wall 80a of the rotating table plate 8o. Further, a stepped pin 9 is provided on the left side portion of the front wall 100a of the base plate 100 in FIG.
3 are erected, and stepped pins 91 are erected on the left side wall 80b of the rotating base plate 8o, and tension springs 92 are installed between the stepped pins 93 and the stepped pins 91. is spread across the board. As a result, the base plate 10
The rotary base plate 8o is urged to rotate in the third counterclockwise direction about the conical shaft 94 with respect to the front surface W, 100a of the rotary base plate 80, and is welded to the right side wall 80a of the rotary base plate 80. The upper surface 90a of the square bar 90 is 1! ! It is pressed against the spherical tip portion 102a of the setting screw 102, and the rotating base plate 80 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, in the front wall 80c of the rotating base plate 80, three elongated holes 8 are formed at equal intervals of approximately 12° on the circumference around the conical shaft 94.
4.85, 86 are formed, and these long holes 84,
Set screws 86, 87°88 passing through 85 and 86 are attached to the base plate 1.
It is screwed onto the front wall 100a of 00 to fix the rotating base plate.

Therefore, if the adjusting screw 102 is rotated with the setscrews 86, 87, and 88 loosened, the rotary base plate 80 will be rotated about the conical shaft 94, and the perpendicularity of the optical axis of the imaging lens 5 will be 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. Further, the three-point support structure of the rotating base plate 80 prevents the rotating base plate 8o 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 wall 200a of the base 200, and three circular pedestals 203 are welded to the front wall 200a, and a left side plate is welded to the left and right ends of the pedestals 203, respectively. A left main shaft 215 and a right main shaft 217 are attached to the right side plate 213 and the right side plate 216 so as to be 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 base 200 is rotatably supported around the left main shaft 215 and the right main shaft 217 by the left support frame 230 and the right support frame 231, which are provided as immovable members with respect to the M document exposure line 13. A left support plate 218 and a right support plate 225 are each welded.

A recess 218a is formed in the center of the left support plate 218, and a 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 left main 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. - Groove 21 on the power wood main shaft 215
5a is formed in an annular shape, and when the square rod 219 comes into contact with the groove bottom 215b of this annular groove 215a, the left main shaft 215 is fixedly positioned 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.

Furthermore, grooves 318c and 218d are recessed in the upper and lower end portions of the left support plate 218 to accommodate the shaft 214 in a loosely fitted state. are screwed onto the upper and lower end portions of the left support plate 218, respectively. By rotating the adjusting screws 222 and 223, the left support plate 218 is rotated about the biaxial shaft.

Further, a bearing portion 225a having an arcuate cross section is recessed in the center portion of the right support plate 225.
A right main shaft 217 is fitted into the main shaft 217 . Also, the right support plate 22
5 has a square rod 22 for positioning the right main 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 left main axis 215 and the left main axis 215, and extends in the sub-scanning direction through the left main axis 215 and the right main 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 adjusting screws 222 and 223 are rotated, the optical axis of the imaging lens 5 is rotated integrally with the base 200, and the inclination in the sub-scanning direction (Y-axis direction) is adjusted. It will be fine-tuned. As a result, the perpendicularity between the optical axis of the imaging lens 5 and the exposure surface of the document in the sub-scanning direction can be 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 set screw 221.2
28 and adjusting screws 222, 223
is fixed in position, and therefore the position of the imaging lens 5 is fixed.

Next, the lens unit 300 and the CCD unit 20
The mechanism for adjusting the movement of the lens in the optical axis direction will be described below.

Next, lens unit 300 and COD 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 inserted into and perpendicular to both the left main shaft 231 and the right main shaft 217. 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 fitting holes 201 and 202, respectively.
Both upper and lower ends of the support shaft 113 are fitted into these elongated shafts 111 and 112. Further, retaining rings 114 are respectively engaged on the upper and lower sides of the upper wall 100b and the lower wall 100C of the upper plate 100 of the support shaft 113, so that the support shaft 113 and the base plate 100 are fixed to the imaging lens 5. It is supported so that it can slide in the optical axis direction. At this time, the base plate 100 is movable in the sub-scanning direction (Y-axis direction) and remains immovable in the main-scanning direction (X-axis direction).

Also, of the three circular pedestals 203 welded to the forward-tilting wall 200a of the base 200, two circular pedestals 203 are arranged at predetermined intervals 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 into which a screw 104, which will be described later, is screwed. 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 106 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 wall 100b 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, the base plate 100, the rotary base plate 80 attached thereto, the lens unit 300, the CCD units 2o, and the CCD units 2o and CCD units attached to the rotary base plate 80 are
Due to the weight of the CD base plate unit 30, support shaft 64, etc.
The force that presses and slides the base plate 100 downward along the support shaft 113 becomes greater than the frictional resistance force between the front wall 100a of the base plate 100 and the front surface 203a of the circular pedestal 203 due to the pressure of the three compression springs 106. Therefore, no spring is used to press and bias the base plate 100 downward. However, if necessary, for example, the lower wall 1 of the base plate 100
00c and the lower wall 200c of the base 200,
It is also possible to arrange the compression spring so that it is inserted into the support shaft 113.

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 300 and the CCD unit 20 can be finely adjusted in the direction of the lens optical axis without causing any mutual positional deviation. And with this, exposure line 1
Fine adjustment of the distance between CCD 3 and CCD 2, that is, the conjugate length (L in FIG. 2) at a predetermined projection magnification, can be easily and accurately performed. Furthermore, during such adjustment, the imaging lens 5 and C0D2 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), No deviation occurs in the direction of inclination in the scanning direction (α direction) or in the direction of inclination in the sub-scanning direction (β direction).

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

3 and 5, a seal body 31 is attached to the lower part 301d of the lens holder 301 of the lens unit 300.
0 is fitted with an upper plate 311 that is adhesively fixed.

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 bonded to a lower plate 312, and this lower plate 312 is formed with a notch 312a that engages with two countersunk screw pins 32 that screw the CCD unit 20 into the channel 31. has been done. The seal body 31
0 is attached and positioned so as to shield the peripheral area outside the imaging optical path of the imaging lens 5 between the lens holder 301 and the metal plate 21 that adhesively holds the CCD 2.

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 of the C0D2 is blocked, and the adhesion of dirt, dust, etc. to the C0D2 is prevented.

Further, the seal body 310 is formed of a material and shape that does not impair air permeability, and is designed to sufficiently prevent interference and deterioration of the image reading function of the C0D2. 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. 5(,), air is forced to be blown by a blower 206, and dust such as dirt and dust is removed by a dust filter 208 attached to a duct 207. It flows into the base 200 from the square hole 205 of the base 200 to the square hole 100 of the base plate 100.
g and the square hole 80e of the rotating base plate 80, and is sprayed toward the seal body 310, the lower part of the CCD 2, and the PCB-122. This blower 206
The air blowing action is controlled based on a temperature detection signal of the CCD 2 emitted from a thermistor 25 that is in contact with and bonded to the back surface of the CCD 2.

With such a cooling device for the CCD unit 2o, C
This prevents expansion and deformation of the C0D2 due to heat generation from the CD2 itself or the PCB-122 soldered to the CCD2, which prevents image reading abnormalities and prevents the electronic components on the PCB-122 from expanding or deforming. 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 C0D2 is made rotatable in the sub-scanning direction, and a CCD unit 20 is formed in which the CCD 2 is integrally formed with a metal plate 21 which is a holding member thereof. A configuration is adopted in which it is retracted to the outside, which facilitates attachment and detachment to the member. In addition, when simply cleaning the CCD 2 without replacing it, the CCD unit 20 is configured to expose the CCD unit 20 at an angle to the front, thereby making the cleaning operation extremely easy. Furthermore, the position of the mounting member of the CCD 2 is configured so that it can be accurately returned to its original position by the GA screw and spring bias even when the CCD unit 2o is replaced, as well as during cleaning, and the dimensions of the CCD unit 20 are The configuration is such that fine adjustments due to the above variations can be made extremely easily.

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 provided elongated hole 62e, the right lever 62 is rotated counterclockwise around the support shaft 64 by the biasing force of the tension spring 61a, and the right lever 62 is rotated counterclockwise around the support shaft 64. A bent portion of the lower arm portion 62f of the movable base plate 50 contacts the lower edge of the right side wall 50d of the movable base plate 50.

As a result, the movable base plate 5o and the support shaft 6 of the right lever 62
The relative position around 4 is made stable. Similarly, when the screw 69 screwed into the left side wall 80b is removed from the elongated hole 63e of the upper arm 63d of the left lever 63, the bent portion of the lower arm 63f of the left lever 63 is attached to the movable base plate 50.
The movable base plate 5o and the left lever 63 are kept in a stable relative position around the support shaft 64.

In this state, as shown in FIG.
The movable base plate 50 on which the CD unit 2o is attached can rotate integrally with the right lever 62 and 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 right boss. The circular arc hole 6 of the right lever 62 is connected to the screws 73 and 74 which are screwed into
2h and one end of the arcuate hole 63h of the left lever 63 are brought into contact with each other to be 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 are extremely easy. Also, in this state, the arcuate hole 62g of the right lever 62 does not come into contact with the adjustment screw 83 that cooperates with the compression spring 65 to position the movable base plate 50 on which the CCD unit 2o is attached in the main scanning direction. The position and size of the arcuate hole 62g are set so as to prevent the adjustment screw 83 from being displaced or deformed due to excessive force being applied to it. . At this time, the movable base plate 5
The holding member (channel 31 in FIG. 3) of the CCD unit 20, which is held so as to be adjustable in position with respect to 0, remains completely unchanged with respect to the movable base plate 5°.

After completing the necessary work such as cleaning and replacing the CCD 2 and CCD unit 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 locked in predetermined positions by screws 68 and 69, respectively, the tension springs 61a and 6
The movable base plate 50 is rotated around the support shaft 64 by the biasing force of the movable base plate 1b. The plate 50 is returned to its original position accurately. Also at this time, the movable base plate 5o
The right side wall 50d is also brought into contact with the adjustment screw 83 at its original position, so that its position in the main scanning direction can also be accurately returned to its original position.

In the image reading device according to the embodiment of the present invention, the position adjustment of the CCD with respect to the imaging lens, the imaging lens 5. A position adjustment mechanism that uses the steps of a screw is used to adjust the position of the CCD2. 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 pressed by a tension spring or gravity in a direction in which they approach each other, and an adjustment screw 39 is screwed into a female thread 38a formed in the square bar 38. The hemispherical tip portion 39a of this adjustment screw 39 is in contact with the upper surface 50i of the movable base plate 50.

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 element 71 made of nylon is fitted into the female thread 73. A set screw 72 is screwed into the female thread 73 from behind the brake 71, and a planar tip 72a of the set screw 72 presses the brake 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 member 71, the distal end portion of the nylon brake member 71 is pressed against the adjustment screw 39 while undergoing compressive deformation, and the distal end portion 71a of the brake member 71 is pressed against the illumination 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 threads and valleys of the female thread 73. . In this state, the male thread of the adjusting screw 39 presses the female thread 38a in the radial direction, and the axial center of the adjusting screw 39 is maintained slightly deviated from the axial center of the female thread 38a. The shaft center position can be rotated without shifting due to rotation. Therefore, the tip 39a of the adjusting screw 39 is not moved in the radial direction of the screw. Female thread 38a
The relative position between the square bar 38 and the movable base plate 5o is adjusted by the steps of the adjusting screw 39 when rotating the adjusting screw 39, which has a male thread that engages with the adjusting screw 39 and the female screw. The contact position of the tip end 39a of the adjusting screw 39 with respect to the upper surface 50i of the movable base plate 5° does not shift due to play in engagement with the adjusting screw 38a.

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 arm 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, no other fastening means is required for locking the adjustment screw 39 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 adjustment screw 39 can be rotated with its axial center position maintained at a predetermined position by the required pressing force, and there is no damage to the threaded portion of the adjustment screw 39. Also, no indentation is caused, and therefore the smooth rotation of the adjusting screw 39 is not hindered in any way.

Such adjustment screw 39, square bar 38. The position adjustment device constituted by the upper surface 50i of the movable base plate 50, the brake 71, and the set screw 72 is different from other position adjustment devices, that is, position adjustment devices using adjustment screws 53, 56, 58° 102, 110, 83. are also adopted in the same way.

[Effects of the Invention] As described above, according to the present invention, the bottom of the right angle between the optical axis of the imaging lens and the main scanning direction of the original image exposure surface is determined by the relative position of the photoelectric conversion element and the imaging lens. It is possible to make fine adjustments without causing any deviation, and it is possible to prevent magnification deviation in the main scanning direction of the imaged image, unilateral point blur, etc. from occurring.

[Brief explanation of drawings]

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
An external perspective view showing the positional relationship with the CD, Figure 3 shows a set of COD reading units.Front explanatory view, Figures 4 and 5 (a) are shown in Figure 1. 5(b) is a front explanatory view showing the shape of the hole provided in the white board; FIG. is a side partial cross-sectional view showing the COD reading unit in an open state, and Figure 7 is C.
FIG. 8 is a plan view showing a CD positioning and fixing structure; FIG. 8 is a cross-sectional view taken along line A-A' in FIG. 7; FIG. 9 is a plan view showing another embodiment of the CCD positioning and fixing structure. 10 is an explanatory cross-sectional view taken along the line BB' in FIG. 9, FIG. 11 is an explanatory cross-sectional view corresponding to FIG. 1o showing another embodiment of the COD connection supplement, and FIG. The image is CC
FIG. 13 is an exploded perspective view showing the fine adjustment structure of D, FIG. 13 is a vertical cross-sectional explanatory view showing the focusing structure of the imaging lens, and FIG. 14 is a view of the reading unit shown in FIG. 3 from the base. 15 is a cross-sectional explanatory view taken along line A-A' in FIG. 14; FIG. 16 is an explanatory cross-sectional view taken along line B-B' in FIG. 14; 17
This figure and FIG. 18 are cross-sectional explanatory views showing the locking structure of the adjustment screw. 1.2, 3...CCD, 4,5.6...imaging lens, 12...original, 13...exposure line, 15...
Reading unit, 20... COD unit, 64...
Support shaft, 5°...movable base plate, 8o...rotating base plate, 94
... Conical shaft, 100 ... Base plate, 200 ... Base,
215, 217... Main shaft, 230, 231... Support frame. Agent ( Kaba et al. + 1.' Toyomi 1--7- (L name) 1 cause β ro40kuniichi7 Figure maximum δ

Claims (1)

[Claims] 1. A document image is projected onto a photoelectric conversion element by an imaging lens, and the document image is read photoelectrically by relatively moving the document image and the photoelectric conversion element in a sub-scanning direction. In the position adjustment mechanism of the image reading device, the movable base plate holding the photoelectric conversion element is movably supported in the main scanning direction, and the lens support member holding the imaging lens at or near the optical center is aligned with the optical axis. At or near the optical center between the rotating base plate that is rotatably supported in the orthogonal direction and the front principal point and rear principal point of the imaging lens, the optical center is located in the sub-scanning direction of the photoelectric conversion element and in the optical center between the front principal point and the rear principal point of the imaging lens. A position adjustment mechanism for an image reading device, wherein the rotary base plate includes a support shaft extending in a direction perpendicular to the optical axis and is mounted rotatably around the support shaft. . 2. In the position adjustment mechanism for an image reading device according to claim 1, the support base plate is provided to be slidable along an axis extending in the optical axis direction of the imaging lens. A position adjustment mechanism for an image reading device, characterized in that a rotating base plate is rotatably engaged via a support shaft. 3. In the position adjustment mechanism for an image reading device according to claim 2, the engaging portion of the support shaft with respect to the support base plate is formed in a conical shape, and the conical inclined surface of the support shaft is connected to the support base plate. A position adjustment mechanism for an image reading device, characterized in that the mechanism is pressed against the side.