JPH033557A - Position adjustment mechanism for picture reader - Google Patents

Abstract

PURPOSE:To adjust the picture element array of a photoelectric conversion element (CCD) and the adjustment in the lens optical axis direction easily with high accuracy by providing a fastening screw adjusting a press contact force of an elastic resin member supporting the positioning adjustment screw to a prescribed position. CONSTITUTION:A damping member 71 made of an elastic resin member is pressed into contact with a pressing force from a fastening screw 72 to a screw section of a positioning adjustment screw 39 provided so as to the prolonged in any direction of the main scanning direction, the subscanning direction and the optical direction. Thus, a tip of the damping member 71 is intruded to a screw of the adjustment screw 39 to support the adjustment screw to a prescribed position. Moreover, the intrusion quantity of the damping member 71 with respect to the adjustment screw 39, that is, the locking force to the adjustment screw 39 is adjusted by adjusting a pressing force by the fastening screw 72. Thus, the adjustment of the CCD picture element array in the main scanning direction, the adjustment in the subscanning direction and the adjustment in the lens optical direction are implemented stably, accurately and easily.

Description

Detailed Description of the Invention [Industrial Application Field] 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 that reads the original image in the sub-scanning direction. 7. Related to Position Adjustment Mechanism for Image Reading Apparatus for Manually Reading [Prior Art] In recent years, optical reading apparatuses for document images have been widely used as 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 841 m (JISAO size) to 36 m (JISAO size).
Some are larger, such as # (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 main scanning direction 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.

High-density t used when particularly high-density reading is required
c In the CD linear sensor, 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-
Publication No. 201572 or JP-A-59-122171
Various COD support structures and position adjustment mechanisms using screws have been proposed in publications such as the above, but in all of them, the adjustment screws tend to be misaligned during adjustment or after positioning, and it is difficult to properly align the CCD. is no longer possible.

The present invention aims to accurately and easily adjust the main scanning direction, the sub-scanning direction, and the lens optical axis direction of the pixel row of the CCD by eliminating misalignment of the adjustment screw for positioning the CCD. It is an object of the present invention to provide a position adjustment mechanism 81 for an image reading device that enables the position adjustment of an image reading device.

[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 a position adjustment mechanism of an image reading device that photoelectrically reads a document image by scanning a document, the positioning mechanism is provided so as to extend in any one of the main scanning direction, sub-scanning direction, and optical axis direction. an elastic resin member that comes into pressure contact with the threaded portion of the adjustment screw to hold the adjustment screw in a fixed position; and an elastic resin member that comes into contact with the rear side of the elastic resin member to increase or decrease the pressing contact force against the adjustment screw. It has a configuration comprising a set screw for adjustment.

[Function] In the means having such a configuration, the adjustment screw for positioning is provided to extend in any one of the main scanning direction, sub-scanning direction, and optical axis direction. A brake made of an elastic resin member is pressed into contact with the part by the pressing force from the set screw, and the tip of the brake will bite into the threaded part of the adjustment screw, thereby holding the adjustment screw in a fixed position. At the same time, by adjusting the pressing force of the set screw, the amount of biting of the brake into the adjusting screw, that is, the locking force to the adjusting screw can be adjusted.

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

As shown in FIG. 1, the H document 12 is illuminated by the elongated illumination lamp 11, and the image on the document 12 is thereby formed in the exposure line 13 by the three imaging lenses 4,
5.6, each one-dimensional photoelectric conversion device (hereinafter COD
(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 applied to a predetermined area a□2QZ in the exposure line 13.
3 are overlapped, and the C0DI, 2.3
When the read signal is output to a writing device (not shown), control is performed to prevent omissions, overlaps, shifts, etc. from occurring at predetermined positions in each overlamp 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
The image is reduced by 102 times and imaged on the pixel row of the CCD 2. The CCD 2 consists of a linear sensor having 5000 pixels (7 μm×7 μm (7) pixels), and the length of the pixel row is set to 35 mm. Therefore, the length of the region Q2 is 317.5+
+n+. Here, the width of the original 12 on the exposure line 13, that is, the maximum reading width Q is 914.4nw.
If n, the overlap on the exposure line 13 is N Q
1□-223 becomes 6.35 pixels, and on the pixel row 2a of the CCD 2, it becomes 0.7 om (100 pixels).

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

In order to read the image separately according to 2.3, each CCDI, 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. .

It is possible to rotate and move for fine adjustment 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 30 mounted on the support shaft 64 so as to be finely adjustable in rotation and finely adjustable in the axial direction.

A CCD unit 20 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 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 left 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. The movement can be fine-tuned.

The CCD 2 of the COD 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 so as to protrude inward, and a main scanning direction reference 921a is formed at the tip of each support piece.
The main scanning direction end surface and the sub scanning direction end surface of the ceramic case of C0D2 are held in contact with the sub scanning direction reference edges 21b and 21c, respectively. Furthermore, the reference edge 21a in the main scanning direction and the reference edges 21b, 21c in the sub-scanning direction 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 C0D2
b and the upper surface of the metal 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.

Further, the CCD control board PCB422, which includes an amplifying circuit for amplifying the image reading signal from the CCD2, is connected to the
It is held by soldering to the connecting pin 2C of the book. C
Two connectors 23 are soldered to the CD control board PCB-122, and flat cables 24 each consisting of a plurality of lead wires are detachably attached to the CD control board PCB-122. CCD
A thermistor 25 for detecting the temperature of the CCD 2 is installed in the mounting hole 22a provided in the control board PCB-122, and is held in place by adhesive with epoxy resin while in contact with the ceramic case of the CCD 2. It has become.

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 of the flat cable 24 is connected to a CCD control board PC.
It is inserted and connected to a connector 401 soldered to the B-2400 (see FIGS. 3 and 5). The COD control board PCB-2400 constitutes a drive control circuit for the CCD 2, and is larger than the COD control board PCB-122 and is equipped with more control electronic components, so it generates less heat. big. Therefore this COD? ll13 Goita PCB-2400 is a CCD
It is desirable to install it as far away as possible from 2.
In this embodiment, the right support leg 100d and the left support leg 100e extending downward from the base plate 100 are locked by screws 404, so that the heat generated by the CCD control board PCB-122 is transferred to the CCD 2. I try not to let it affect me.

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 example, as mentioned above, C0D
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 C0D2. In other words, at the edge of the positioning hole 21g,
Main scanning direction reference edge 21a and sub scanning direction reference edge 21b
, 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 with a cross section of [[11SL shape, and the rear part 301b of the lens holder 301 is formed with three convex parts 301e, and the rotating base plate 8
0 is formed. The convex portion 301
The flat surface of the protruding end of e and the holder lower surface 301d are cut so as to have a perpendicular relationship, and a fitting hole 304 for accommodating the imaging lens 5 is formed with reference to both surfaces 301e and 301d. It is formed to penetrate in the direction of the optical axis. That is, the axis of the fitting hole 304 is positioned accurately so that it is 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. And this fitting hole 30
An imaging lens 5 is fitted within the lens 4 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 screw 95 is used to lock the conical shaft 94 to the front wall 80c of the rotating base plate 8o. 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 30Le. There is. On the other hand, a movable base plate 50 holding the 069 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 3o2. , 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, and a cylindrical eccentric cam 306a is provided at the tip of the focus adjustment shaft 306. This eccentric cam 306a
is engaged within groove 322. The eccentric cam 306a
is formed to have a diameter of 8 mm, and is offset by 1.5 m++ with respect to the axis of the main axis 306c of the focus adjustment shaft 306.

The length in the axial direction is set 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 nn, 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 is connected to the small diameter shaft 306e. It is integrally connected to the auxiliary shaft 306f via. Auxiliary shaft 306f
is formed to have the same diameter as the main shaft 3°6c, and the auxiliary shaft 306
A slotted portion 306g into which a driver can be fitted is formed on the end face of f. 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 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 P1 causes the eccentric cam 306a to The distal end surface 306b is pressed against the groove bottom surface 322a of the groove 322, 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 axis 306c of the focus adjustment shaft 306 and the auxiliary axis 3
06 is pressed against the wall surface of the fitting hole 305 and maintained without any play, and rotation of the focus adjustment shaft 306 is braked by frictional force. At this time, the pressing force against the groove bottom surface 322a by the end surface 306b of the eccentric cam 306a, that is, the frictional force between the lens barrel 321 and the fitting hole 304 is based on the pressing force from 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 barrel 321 and the fitting hole 304
The pressing force from the set screw 308 against the pressure rod 307 is adjusted to such an extent that it does not become larger than the pressing force from the leaf spring 325 against the pressure rod 307 .

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 m-stripe image, that is, in the direction to eliminate single focus blur in the main scanning direction, and at this time, in the optical axis direction. is maintained in a state of no play.

After the focus adjustment is completed, the imaging lens 5 is displaced relative to the lens holder 301 by further tightening the set screw 308 to increase the axial component force P□ and the axis-perpendicular component force P2. It is securely latched and focused! The rotation of the i-adjustment shaft 306 will be restrained.

Next, the position of C and CD2 [1 mechanism will be explained based on FIGS. 3, 4, 5, 12, 18, and 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 described above, the CCD unit 20 having the metal plate 21 that holds the CCD 2 at a constant 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, the above-mentioned CCD shall be easily replaceable within a positional deviation range of 200 to 300 μm>HH.
The control board PCB-122 is positioned so as to protrude downward from a rectangular mounting hole 31a formed in the control panel 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 1
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 5o, a vertical shaft 35 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, the channel 31 including the CCD unit 20
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 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 5o 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 31a 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
The square bar 38 extends obliquely at an angle of about 45 degrees with respect to the two axes (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 pressing force exerted by the tension springs 37a and 37b. As a result, the entire channel 31 including the COD unit 20 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 pressing force of 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 5o.
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
, the lower surfaces of the cylindrical portions 33b at both ends of the horizontal shaft 33 are urged to be more strongly pressed against the upper surface 50a of the movable base plate 50, and 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. 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 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 31e 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 kept in contact with the front side wall surface 31e of the channel 31 in the Y-axis direction. Since the perpendicularity of the 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 above-mentioned sliding movement, and there is no problem in adjustment. 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 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. Furthermore, since the vertical axis 35 is provided at a position sufficiently apart from the CCD 2, the CCD 2 may be 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. rare.

Next, position adjustment in the Y-axis direction, which is the sub-scanning direction, and the X-axis direction, which is the main scanning direction, of C0D2 will be explained. These square bars 5
5. Adjustment screws 56° and 58 are screwed to 57. The tip portions of the adjustment screws 56 and 58 are formed into a spherical shape, and the spherical tip portions are connected to the front wall 80 of the rotating base plate 80.
It is abutted on c.

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 particularly shown in FIG. 4, L-shaped plates 59 and 6o are screwed to the upper sides of the right side u50d and left side wall 50a, respectively. One ends of tension springs 61'a and 61b are attached to holes 59a and 60a formed at the tips of these L-shaped plates 59 and 60, respectively. 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. Fitting holes 62a and 63a are formed in the right lever 62 and left lever 63, and the supporting shaft 64 is fitted into these fitting holes 62a and 63a. The right lever 62 and the left lever 63 are arranged on the outside of the right side wall 50d and left side wall 50e of the movable base plate 50, respectively, and are inserted into elongated holes 62e formed in their upper arm parts 62d and 63d.
By engaging the locking screws 68 and 69 in the locking screws 63a and 63a, the rotation of the right lever 62 and the left lever 63 with respect to the support shaft 64 is respectively restrained. Note that the locking screws 68 and 69 are attached to the rotating base plate 8.
They are screwed into the right side wall 80a and left side wall 80b of o so as to penetrate in the X-axis direction.

Further, holes 62c and 63c are formed in the middle arm parts 62b and 63b which 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 80. 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 COD unit 2o 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.

By a fine adjustment mechanism having such a configuration.

Fine adjustment of position movement in the Y-axis direction, which is the sub-scanning direction, is performed accurately. That is, by rotating the adjustment screws 56 and 58, the movable base plate 5o is rotated about the support shaft 64 in opposition to the tension springs 61a and 61b.
The CD 2 is positioned in the Y-axis direction. At this time, since the rotation center position and the adjustment action position are separated by 161 points 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. can be set. Note that the movement adjustment operation in the sub-scanning direction by the adjustment screws 56 and 58 is performed by rotational movement around the support shaft 64, but C
0D2 is arranged spaced apart from the support shaft 64;
Since the amount of movement for position adjustment is 1 to 2I, the deviation in the inclination β direction of C0D2 in the sub-scanning direction is extremely small and there is no problem. Furthermore, as in this example, the pixel dimensions are extremely small (7 μm x 7 μm).
) When a linear sensor is used, 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 reprojected onto the 9 pixel rows.

Furthermore, 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 80, respectively. 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 through a washer 66 and locked. I'm here.

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, an adjustment screw 83 is screwed into the right boss 81 so as to pass therethrough, and a spherical tip portion 83 of this adjustment screw 83 is fitted.
a is in contact with the right side wall Sod of the movable base plate 5o.

The movement force of the movable base plate 50 by the compression spring 65 causes the movable base plate 50 to move to the right side! ! 50d is adapted to be 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 set to 0.5m, and the CC
In order to satisfy the position adjustment accuracy of 63.5 μm for the pixel row 2a of D2, it is sufficient to rotate the adjustment screw 83 with an accuracy of about 45 degrees, making the adjustment operation extremely easy. . CCD2 by this adjustment screw 83
In the main scanning direction (X-axis direction) adjustment operation, the CCD
Position 2 is in the sub-scanning direction (Y-axis direction) and in the main-scanning tilt direction (
α direction), the direction around the optical axis (γ direction), or the Z-axis direction. This is because the surface angle between the support shaft 64 and the optical axis of the imaging lens 5 has an accuracy of ±1' In addition, the parallelism of the support shaft 64 to the exposure line 13 of the original image is similarly maintained within an accuracy of ±1', and the movable base plate 50 is configured to be adjustable by the tension springs 61a and 61b. This is because the movable base plate 50 is pressed in the radial direction of the support shaft 64 by the urging 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 8o via the adjustment screws 56 and 58.

Further, as in this embodiment, the dimensions of the pixel row 2a of the CCD 2 (
35nm), the spindle 64 has a sufficient spacing (180nm).
), the positional accuracy of the right boss 81 and left boss 82 supporting the support shaft 64 in the sub-scanning direction (Y-axis direction) is within the normal machining accuracy (for example, ±O, in
(about n), but the position vR adjustment amount 2 of the CCD 2 in the main scanning direction
The positional deviation in the sub-scanning direction (Y-axis direction) with respect to ra 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 optical 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. As a result, the rotating base plate 80 is
is rotatable about a conical shaft 94.

On the other hand, the third
A pedestal 101 is welded to the left side of the figure, and an adjustment screw 102 is inserted into the screw hole formed in the pedestal 101.
are screwed together so that they pass through.

The spherical tip portion 102a of the adjusting screw 102 is in contact with the upper surface 90a of the square rod 9o that is welded to the right side wall 80a of the rotating table plate 80. 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 bins 91 are erected on the left side wall 8ob of the rotating base plate 80, and tension springs 92 are installed between the stepped bins 93 and the stepped pins 91. is spread across the board. As a result, the base plate 10
The rotating base plate 8o is connected to the conical shaft 94 with respect to the front wall 100a of
The third member is rotated counterclockwise around , and
The upper surface 90a of the square bar 9o welded to the right side wall 80a of the rotating base plate 80 is the spherical tip portion 10 of the adjustment screw 102.
2a and the rotary base plate 80 is restrained, the conical shaft 94 is pressed downward perpendicularly to the conical shaft 94, but as described above. As the conical inclined surface 94a of the conical shaft 94 is engaged with the circular arc hole portion 120a of the engagement hole 120, the conical shaft 94 receives a component of force directed to the left in FIG. The movable base plate 8o is pressed against the base plate 100 side 6 Also, on the front face 1100a of the base plate 100, three circular bases 100f are arranged at equal intervals of approximately 120° on the circumference centered on the conical shaft 94. are formed, and the outer surface of the front wall 80C of the rotary base plate 80 is brought into contact with these circular bases 100f, and the rotary base plate 80 is supported at three points, thereby stabilizing the rotary base plate 80. It is designed to be rotated.

In addition, three elongated holes 84, 85, 86 are formed in the front wall 80c of the rotating base plate 80 on the circumference centered on the conical shaft 94 at an equal pitch of approximately 12°. Set screws 86, 87° 88 passing through the elongated holes 84, 85, 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 liquid at right angles to the optical axis of the imaging lens 5 is rotated. will be adjusted.

In the optical axis perpendicularity adjustment operation using the adjustment screw 102, the position of C0D2 is 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 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 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. Support plate 218 and 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 fine point of the left main axis 215 and the left main axis 215, and is set in a plane that passes through the left main axis 215 and the right main axis 217 and extends in the sub-scanning direction.
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 M document exposure surface 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 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, 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.

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 left main shaft 231
and the support shaft 11 at right angles to both axes of the right main shaft 217.
3 is inserted. On the other hand, the upper flange wall 10 of the base plate 100
Both fitting holes 201,
Elongated hole 1 extending long in the sub-scanning direction at a position corresponding to 202
11.degree. 112 are formed respectively, and both upper and lower end portions of the support shaft 113 are fitted into these elongated holes 111 and 112. Also, the upper wall 100b and the lower ulo of the upper plate 100 of the support shaft 113.

Retaining rings 114 are respectively locked on the upper and lower sides of C, which allows the support shaft 11 to be held together with the base plate 1o○.
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
It is movable in the main scanning direction (X-axis direction) and remains stationary in the main scanning direction (X-axis direction).

Furthermore, among the three circular pedestals 203 welded to the front wall 200a of the base 200, two 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. Along with 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 pedestal 203, and the base plate 10d is pressed against the circular pedestal 203 by the urging force of the compression springs 106 at three locations along the support shaft 113. 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 1 of the above MA setting screw 110
10a 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 rotating base plate 80 attached to the base plate 100, and the lens unit 300, COD unit 20, and C
Due to the weight of the CD base plate unit 3o, 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 COD 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
3 and C0D2, that is, the conjugate length (L in FIG. 2) at a predetermined projection magnification, can be easily and accurately fine-tuned. 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), 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 C0D2 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 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 COD unit 20 into the channel 31. The sealing body 310 is mounted 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 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 degraded. 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 seal body 310 to 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
11 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 ensures that the lens is positioned securely. Holder 3o1. This prevents excessive force from being applied to the metal plate 21.

In the cooling system shown in FIG. 5(a), the air that is forced to be blown by a blower 206 is filtered by a dust filter 208 attached to a duct 207, and then filtered to the base. flowed into the stand 200,
From the square hole 205 of the base 200 to the square hole 100g of the base plate 100
The liquid passes through the square hole 80e of the rotating base plate 8o, and is sprayed toward the sealing body 310, the lower part of the CCD 2, and the PCB-122. The blowing action of the blower 206 is controlled based on a temperature detection signal of the CCD 2 emitted from a thermistor 25 that is in contact with and adhered 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 generated from the 0D2 itself or the PCB-122 soldered to the C0D2. This prevents image reading errors 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 M 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 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, even when the CCD unit 20 is replaced, as well as during cleaning, the position of the mounting member of the C0D2 is configured to be accurately returned to its original position by the biasing force of the adjustment screw and spring, and the dimensions of the CCD unit 20 are The structure 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. 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.

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 5° with the D unit 20 attached is 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 arcuate hole 62 of the right lever 62
h and one end of the arcuate hole 63h of the left lever 63 are brought into contact with each other. 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. In addition, 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 5o on which the CCD unit 20 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 5o
The holding member (channel 31 in FIG. 3) of the COD unit 2o, which is held in a position adjustable manner with respect to the movable base plate 50, is maintained in a completely unchanged state with respect to the movable base plate 50.

After completing the necessary work such as cleaning and replacing the CCD 2 and COD unit 2o, 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 urging force of the movable base plate 1b, and at this time, the tips of the adjustment screws 56, 58 are brought into contact with the front wall 80c of the rotary base plate 80, so that the movable base plate 50 is movable. The base plate 50 is 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 50d of 0 is also brought into contact with the adjustment screw 83 at its original position, and its position in the main scanning direction is also accurately returned to its original position.

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 COD 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 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 element 71, and a planar tip 72a of the set screw 72 presses 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 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 offset 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 adjustment screw 39 is
It is not moved in the radial direction of the screw. When rotating the adjustment screw 39 having a male thread that engages with the female screw 38a, the relative position between the one-sided bar 38 and the movable base plate 50 is adjusted by the step of the adjustment screw 39. The abutment position of the tip end 39a of the adjusting screw 39 against the upper surface 50i of the movable base plate 5° does not shift due to play in the engagement between the adjusting screw 39 and the female 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 screw advances or retreats, and can be further adjusted as necessary.

In such a configuration, the set screw 72 is further screwed in after the relative position between the movable base plate 50 and the square bar 38 is adjusted iA by moving the adjustment screw 39 back and forth, and thereby the brake 71 is further pressed and deformed. Adjustment screw 39 is female thread 3
8a. In this case, the set screw 72
The adjustment screw 39 will not be displaced from the female thread 38a by screwing in. Therefore, no other fastening means is required for locking the adjustment screw 39 to the female thread 38a.

For some reason, the adjustment screw 39 has been rotated, and the mutual positions of the movable base plate 5o and the square bar 38 have been changed again! 4m
When it becomes necessary to do so, the set screw 72 is slightly loosened to reduce the pressing force of the brake 71 against the adjustment screw 39. 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. and will not be indented and therefore! l! There is no problem in the smooth rotation of the I adjustment screw 39.

The position adjustment device constituted by the adjustment screw 39, the square bar 38, the upper surface 50i of the movable base plate 50, the brake 71, and the set screw 72 is similar to other position adjustment devices, that is, the adjustment screws 53, 56, and 58°. The same method is adopted in a position adjustment device using 102.110.83.

[Effects of the Invention] As described above, according to the present invention, when positioning the COD, the adjustment screw for positioning the COD can be rotated and adjusted without moving in the radial direction, and the main pixel column of the COD can be rotated and adjusted. Adjustment in the scanning direction, sub-scanning direction, and lens optical axis direction can be performed stably, accurately, and easily.

[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 OD, Fig. 3 is a front explanatory view showing a set of CCD reading units, and Figs. 4 and 5 (,) show the CCD shown in Fig. 3. FIG. 5(b) is a front explanatory view showing the shape of the hole provided in the base plate, and FIG. C
FIG. 7 is a plan view showing the COD positioning and fixing structure; 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 CCD positioning and fixing structure, FIG. 10 is an explanatory cross-sectional view taken along the line B-B' in FIG. 9, and FIG. 11 is an explanatory plan view of the COD connection. FIG. 12 is an exploded perspective view showing a COD fine adjustment supplement, and FIG. 13 is a vertical cross-sectional view showing the focusing lens mounting structure. FIG. 14 is a front explanatory view showing the reading unit shown in FIG. 3 removed from the base;
Fig. 15 is an explanatory cross-sectional view taken along the line A-A' in Fig. 14, Fig. 16 is an explanatory cross-sectional view taken along the line B-B' in Fig. 14, and Figs. 17 and 18 are the adjustment screws. FIG. 1.2, 3...CCD, 4,5,6...imaging lens. 12... Original, 13... Exposure line, 15... Reading unit, 20... CCD unit, 39, 53,
56゜58.102,110,83...adjustment screw, 7
1... Brake element, 72... Set screw, 50... Movable base plate 6-14? 1σ diagram 2 β shape 40 circles 47 shapes, // 3 shapes 40 circles Ie circle

Claims (1)

[Claims] An image in which a document image is projected onto a photoelectric conversion element by an imaging lens, and the document image is read photoelectrically by moving the document image and the photoelectric conversion element relative to each other in the sub-scanning direction. In the position adjustment mechanism of the reading device, a positioning adjustment screw provided to extend in any one of the main scanning direction, sub-scanning direction, and optical axis direction; and a threaded portion of the adjustment screw; A brake made of an elastic resin member that is pressed into contact to hold the adjustment screw in a fixed position, and a set screw that comes into contact with the rear side of the elastic resin member and adjusts the pressing contact force to the adjustment screw to increase or decrease. A position adjustment mechanism for an image reading device, characterized in that: