JPH033553A - Position adjustment mechanism for picture reader - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

[Industrial Application Fields] The present invention provides a method for photoelectrically reading the original image by relatively moving the 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. [Prior Art] In recent years, optical reading devices for document images have been widely used in office equipment such as copying machines and facsimile machines. The size of documents to be read in general is limited to a maximum of A3 size,
In certain fields such as industrial drawings, the size of target manuscripts may be large, such as 111 g 841 mm (JISAO size) to 3671941 mm (ANSZ E size). For such large documents, it is impossible to reduce and project the image onto a single photoelectric converter 3- (hereinafter referred to as COD) and read it, and conventional reading devices for general office use cannot do so. Reading cannot be performed 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. [Problem to be Solved by the Invention] However, in such a split-type reading device, for example, the CCD is positioned and arranged so that the main scanning direction of each COD perfectly matches the width direction of the original image. It is impossible to photoelectrically read the original image unless the original image and the photoelectric conversion element are moved relative to each other in the sub-scanning direction. 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 COD, as well as temperature changes. . Additionally, although the COD installed in the document reading device is designed to prevent dirt and dust from adhering to the surface of the cover glass, it can 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. Conventionally, JP-A-62-48940, JP-A-51
-51217 publication or Utility Model Application Publication No. 61-171353
Although structures for facilitating the support and replacement of CODs have been proposed in Japanese Patent Publication No. 2003-120003, they have not yet fully met the above-mentioned requirements. SUMMARY OF THE INVENTION An object of the present invention is to provide a position adjustment mechanism for an image reading device that allows easy replacement and cleaning while accurately positioning a COD. [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 that photoelectrically reads the original image by moving the image, the photoelectric conversion element is movable in the main scanning direction and rotatable around an axis extending in the main scanning direction. The photoelectric conversion element is provided with sliding biasing means for applying a biasing force in the main scanning direction and rotational biasing means for applying a biasing force around an axis in the main scanning direction, The rotational biasing means is provided with an opening/closing mechanism that biases or deenergizes the biasing force of the rotational biasing means to rotate the photoelectric conversion element into and out of the imaging optical path. have. [Operation] In the means having such a configuration, by reducing the urging force of the rotational urging means by the opening/closing mechanism, the photoelectric conversion element is rotated out of the imaging optical path, and the photoelectric conversion element is rotated out of the imaging optical path. The handling of the element is now easier.

[Example] Hereinafter, an example 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 transmitted to a predetermined area 212 121 in the exposure line 13.
3 are overlapped, and the CCDI, 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
The image is reduced to 102 times and focused on the pixel row of the CCD2. CCD2 is 7 μm x 7 μm
It consists of a linear sensor having 50oO pixels (ρ1cxel), and the length of the pixel row is set to 35mm. Therefore, the length of the above region Q□ is 317
．． 5IIn+. Here, the width of the original 12 on the exposure line 13, that is, the maximum reading width Q, is 914.
4+nm, the overlap amount Q□2-Q23 on the exposure line 13 is 6.35 nm, and on the pixel row 2a of the CCD 2 it is 0.7 mm (100 pixels). In this way, the image of the original 12 is transferred to multiple CGDIs. In order to read the image separately according to 2.3, each CCDI, the reading magnification 1 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 rotating 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 2o is held in the CCD base plate unit 30, and a sealing member 310 having light-shielding properties, dust-proofing properties, and air permeability is installed between the CCD unit 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 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 2o is fitted into a substantially rectangular positioning hole 21g provided in the metal plate 21, as shown in FIGS. 7 and 8. At the edge of the positioning hole 21g, three support pieces are formed to protrude inward, and a main scanning direction reference Q21 is formed at the tip of each support piece.
a and the sub-scanning direction reference edges 21b and 21c,
The end face in the main scanning direction and the end face in the sub-scanning direction of the ceramic case of the CCD 2 are held in contact with each other. 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 2b of the CCD 2 and the upper surface of the metal plate 21 are placed on the same plane. Furthermore, a two-component epoxy resin is injected and hardened into the gap between the ceramic case of C0D2 and the positioning hole 21g, so that the CCD 2 remains immovable. Further, the CCD control board PCB-122, which includes an amplifying circuit for amplifying the image reading signal from the CCD2, is connected to the CCD2 of C0D2.
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. C.C.
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 COD 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 above CCD control board PCB-2400 has CCD2 (
7) It constitutes a 1-section motion control circuit, and the CC
It is larger than the D control board PCB-122 and has more control electronic components mounted thereon, and therefore generates more heat. Therefore, this CCD control board PCB-2400 has CCD 2
It is desirable to install the right support leg 100d and the left support leg 100e extending downward from the base plate 100 by means of screws 404. COD control board P
The heat generated by the CB-122 is prevented from affecting the CCD 2. The CCD control boards PCB- which are spaced apart from each other in this way
122 and the COD 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 edge 21a and sub scanning direction reference edge 21b
, 21c plus optical axis direction reference! 21f are provided at three locations, and the CC is
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 COD 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 an abbreviated cross section, 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 8o is also formed. The protruding tip plane part of the convex part 301e and the holder lower surface part 301d are cut so as to have a perpendicular relationship, and furthermore, with these both surfaces 301e and 301d as a reference, a fitting part for housing the imaging lens 5 is formed. A hole 304 is formed through the optical axis direction. That is, the axis of the fitting hole 304 is precisely positioned to be perpendicular to the holder lower surface 301d of the lens holder 301 and parallel to the flat surface of the protruding end of the convex portion 301e. The imaging lens 5 is fitted into the fitting hole 304 so as to be slid back and forth in the direction of its front axis. Further, a fitting hole 302 is formed in the rear part 301b of the lens holder 301, into which the outer circumference of the cylindrical female thread 95 is fitted. The above-mentioned cylindrical female thread 95 is. The conical shaft 94 is locked to the front wall 80c of the rotating base plate 80. At this time, the formation position of the fitting hole 302 is precisely set on the optical center of the imaging lens 5 in a direction perpendicular to the optical axis of the lens and perpendicular to the flat surface of the protruding end of the convex portion 301e. There is. On the other hand, a movable base plate 50 holding the CCD base plate unit 3o is rotatably and slidably supported on the support shaft 64. After the holder lower surface portion 301d is set to be parallel to the support shaft 64, it is secured to the rotating base plate 80 with three screws 309. This ensures the required perpendicular precision between the optical axis of the imaging lens 5 and the support shaft 64. 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 with a diameter of 8I111+, and the focus adjustment shaft 306a is formed with a diameter of 8I111+.
It is eccentric by 1.5 m with respect to the axis of the main shaft 306c, and the 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 12
The eccentric cam 306c is formed into a cylindrical shape of mm.
A conical portion 306d with an apex angle of 90″ is formed on the opposite side of the auxiliary shaft 306f, and this conical portion 306d is integrally connected to an auxiliary shaft 306f via a small diameter shaft 306e. A slotted portion 306g is formed on the end face of the auxiliary shaft 306f to allow a driver to fit therein.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 is pressed.Component forces P□ and P2 of the pressing force of the pressurizing rod 307 at these pressure contact points are in the axial direction of the focus adjustment shaft 306 and in the direction orthogonal to the axis. The leading end surface 306b of the eccentric cam 306a is pressed against the groove bottom surface 322a of the groove 322 by the axial component force P□, and thereby the lens barrel 321 is pressed against the wall surface of the fitting hole 304 and there is no 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. The rotation of the 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 , a set screw 30 for 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 causes the plate against the lens barrel 321. The set screw 30 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 8 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 imaging lens 5 is prevented from rotating around the optical axis by the pressing force of the leaf spring 325, and the groove 3
The groove side surface 322b of No. 22 is maintained in pressure contact with the cam surface of the eccentric cam 306a. As a result, the imaging lens 5 is always movable for fine focusing adjustment in the most desirable direction for reading the original image, that is, in the direction to eliminate unilateral point 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 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 position adjustment mechanism of C0D2, 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 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 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 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 50 having a U-shaped cross section.
is in contact with. On the other hand, stepped pins 36a and 36b are provided on the front wall 31e and rear wall 31f of the channel 31 in the Y-axis direction.
are respectively screwed in the vicinity of the square rod 38, and the upper ends of tension springs 37a and 37b are hung on these stepped pins 36a and 36b, respectively. The lower ends of the tension springs 37a and 37b are hung on stepped pins 54a and 54b 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 pressing force exerted by the tension springs 37a and 37b. As a result, the entire channel 31 including the CCD unit 20 connects to the vertical axis 35 and the movable base plate 5 via the horizontal axis 33.
The three-point support state is maintained by o. Further, due to the downward pressing force of the tension springs 37a and 37b, the spherical tip portion 39a of the adjustment 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
, the lower surfaces of the cylindrical portions 33b on both ends of the horizontal shaft 33 are urged to be more strongly pressed against the upper surface 50a of the movable base plate 5o, and the two are separated from each other. The biasing force of the stepped pins 36a and 36b, which are brought into close contact with each other, 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 protruding 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 moved once 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 above-mentioned 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 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. But. 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 hardly rotated around the horizontal axis 33 by the sliding movement. There are no problems with adjustment. Furthermore, since the vertical axis 35 is provided at a position sufficiently separated from the CCD 2, the CCD 2 is rarely 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. do not have. 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. 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 8o.
It is abutted on c. On the other hand, the right side u50d of the movable base plate 50 in the X-axis direction
Fitting holes 5'Of are formed through the left side wall 50e, and each of these fitting holes 50f connects 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 60 are screwed to the upper sides of the right side wall 50d and left side wall 50e, respectively. Holes 59a and 60a formed at the tips of these L-shaped plates 59 and 60
One ends of tension springs 61a and 61b are attached to. 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.
11 of the right lever 62 and the left lever 63 by engaging the locking screws 68 and 69 in 63e and 63e.
Rotation with respect to 1164 is restrained. The locking screws 68 and 69 are screwed into the right side wall 80a and the left side wall 80b of the rotating table plate 80, respectively, so as to penetrate in the X-axis direction. Further, holes 62c and 63c are formed in the middle arm 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 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 5o is about to be rotated around the fourth centroid by the urging force of the tension springs 61a and 61b, but the spherical tip portions 56a and 58a of the adjustment screws 56 and 58 are attached to the front wall 80c of the rotary base plate 8o. It is stopped by being pressed against the top. 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, so that the movable base plate 50 is pressed against the support shaft 6.1. It will be forced and 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, arcuate holes 62g, 62h and 63g, 63h are provided to face each other, and one of the arcuate holes 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 spaced apart from each other compared to the distance between the rotation center position and the CCD 2, fine adjustments can be made without using a complicated mechanism such as a differential screw. be able to. Note that this adjustment screw 56.
The movement adjustment operation in the sub-scanning direction by 58 is performed by a rotational movement around the support shaft 64, but the CCD 2 is spaced apart from the support shaft 64 and the amount of movement for position adjustment is 1. ~2[lIn, so C
There is no problem because the deviation in the inclination β direction of the CD 2 in the sub-scanning direction is extremely small. Furthermore, when a linear sensor with extremely small pixel dimensions (7 μm×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, by slightly tilting the C0D2 in the sub-scanning direction with respect to the optical axis, the reflected image of the projected image by the cover glass 2b of the CCD2 is re-projected onto the pixel row. This is preferable because it can be avoided. 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 8.2b. Further, a compression spring 65 is fitted to the outside of the support shaft 64 . One end portion of this compression spring 65 is connected to the movable base plate 5.
It is supported on the inner surface of the right side wall 50d of 0, and
The other end portion of the compression spring 65 is pressed into contact with a pin 67 fixed through the support shaft 64 via a washer 66 and locked therein. 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, for the right boss 81 above,! 81 is screwed so as to penetrate therethrough, and the spherical tip portion 83a of this adjustment screw 83 is in contact with the right side wall 50d of the movable base plate 50. 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 the force of movement of the movable base plate 50 by the compression spring 65. 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 0.5 mm,
Position Fl accuracy of pixel row 2a of CCD 2: 63.5 μm'
In order to satisfy this requirement, it is only necessary to rotate the adjustment screw 83 with an accuracy of about 45 degrees, and the adjustment operation can be performed extremely easily. In the main scanning direction (X-axis direction) adjustment operation of the CCD 2 using this III screw 83. The position of C0D2 does not shift 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 perpendicularity between the support shaft 64 and the optical axis of the imaging lens 5 is ±1'.
The M of the support shaft 64 can be adjusted with an accuracy of
Similarly, the parallelism of the original image to the exposure line 13 is ±1'.
The movable base plate 50 is pressed in the radial direction of the support shaft 64 by the biasing forces of the tension springs 61a and 61b, and at the same time, the rotation of the rotary base plate 80 is maintained through the adjusting screws 56 and 58. This is because the position of the movable base plate 50 is maintained by the front wall 80c. Also, as in this embodiment, the dimensions of the pixel row 2a of C0D2 (
35mm), the spindle 64 has sufficient spacing (180na
), 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 normal processing accuracy (for example, ±O, in
n), but the position adjustment amount in the main scanning direction X of C0D2 is 2 m.
The positional deviation in the sub-scanning direction (Y-axis direction) relative to + is 2 μm
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 so as to be perpendicular to the 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, and is attached to the front wall 100a of the base plate LOO. The large diameter side of the conical shaft 94 of the cone @94 passes through the arcuate 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
The circular arc hole portion 120a of 20 is 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 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 pins 91 are erected on the left side wall 80b of the rotating base plate 80, 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 rotating base plate 80 is connected to the conical shaft 94 with respect to the front wall 100a of
It is urged to rotate around the third mouth centering on , and
The upper surface 90a of the square rod 90 welded to the right side wall 8°a of the rotating base plate 80 is the spherical tip portion 10 of the adjustment screw 102.
2a, 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 being engaged with the conical shaft 94, the conical shaft 94 receives a component force directed to the left in FIG. Also, the base plate 1
On the front wall 100a of 00, three circular pedestals 100f are formed at equal intervals of approximately 120' on the circumference around the conical axis 94, and these circular pedestals 10
The outer surface of the front wall 80C of the rotating base [80] is brought into contact with the rotating base 80, and the rotating base plate 80 is supported at three points, thereby allowing the rotating base plate 8o to rotate stably. There is. In addition, three elongated holes 84, 85, 86 are formed in the front wall 80c of the rotating base plate 80 at an equal pitch of approximately 120° on the circumference centered on the conical shaft 94. Long hole 84
, 85, 86 are screwed into 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 perpendicularity of the optical axis of the imaging lens 5 is In the perpendicularity adjustment operation of the optical axis using the adjusting 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), and the main scanning tilt direction ( (alpha direction), the direction around the optical axis (gamma direction), or the Z-axis direction. Also, due to the three-point support structure of the rotating plywood 80, the rotating base plate 8o
deformation is prevented. 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 symmetrical positions of 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 on the bottom surface 218f of the four parts 218a.
A square bar 219 for positioning 5 is fixed by two setscrews 220. - Groove 21 on the right and left upper shafts 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 adjustment screws 222 and 223, the left support plate 218 is rotated about both main shafts. Further, a bearing portion 225a having an arcuate cross section is recessed in the center portion of the right support plate 225.
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 upper right 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 is finely adjusted.9 In such an adjustment operation, the imaging lens 5 is axial direction) or in the inclination direction (α direction) of the main scanning direction. Further, after adjusting the inclination of the optical axis of the imaging lens 5 in the sub-scanning direction, the upper
28 and adjustment screws 222, 223 to adjust the base 2oO.
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 201 and 202 are formed in the upper wall 200b and lower side M200c of M200, respectively, so as to face each other. These fitting holes 201. , 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 13 are fitted into these elongated holes 111 and 112. In addition, retaining rings 114 are respectively secured to the upper and lower sides of the upper plate 100, the side wall 100b, and the lower wall 100C of the upper plate 100. It is supported so that it can slide in the direction of the optical axis of 5. 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). 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 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 Jixoob 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 adjustment screw 110
10a passes through a large diameter hole (not shown) formed in the base plate 1o and connects to the upper wall 200b of the base 200.
is in contact with. In this embodiment, a base plate 100, a rotary base plate 80 attached to the base plate 100, and a lens unit 300, a CCD, and a lens unit 20 attached to the rotary base plate 8o are used.
．． The force that presses and slides the base plate 100 downward along the support shaft 113 due to the weight of the CCD base plate unit 30, the support shaft 64, etc. is applied to the base plate 10 by the pressure of the three compression springs 106.
Since the frictional resistance force is larger than the frictional force between the front wall 100a of the oO and the front surface 203a of the circular pedestal 203, no spring is used to press the oO downward. However, if necessary, a compression spring may be inserted into the support shaft 113, for example, between the lower wall 100C of the base plate 100 and the lower wall 200c of the base 200. In such a configuration, by rotating the adjustment screw 110, the base plate 100 is finely adjusted and moved along the support shaft 113 while in contact with the circular base 203. Therefore, by moving the adjusting screw 110 back and forth, the lens unit 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. 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 glued to a lower plate 312, and this lower plate 312 has notches that engage with two countersunk screw pins 32 that screw the CCD 22 1-20 into the channel 31. A cutout 312a is formed. The above seal body 3
10 is mounted and positioned so as to shield the peripheral area outside the imaging optical path formed by the imaging lens S 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
This will block external light that would degrade the image reading signal of the C0D2, and prevent dust such as dust from adhering to the C0D2.The sealing body 310 is made of a material and shape that does not impair air permeability. It is formed in such a manner 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 sealing body 310 to which the upper plate 311 and the lower plate 312 are vertically bonded can be easily removed 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 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
It passes through the square hole 80e of the rotating base plate 8o, and is sprayed toward the seal body 31o, 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 CCD2 due to heat generation from the CD2 itself or the PCB-122 soldered to the C0D2. This prevents image reading errors from occurring, and also 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 the CCD 2 is mounted on a CCD that is integrally formed with the metal plate 21 that is the holding member thereof.
A configuration is adopted in which the unit 20 is retracted out of the imaging optical path, thereby facilitating attachment and detachment to a member. In addition, when simply cleaning the CCD 2 without replacing it, the CCD unit 2Q is configured to be tilted to the front for exposure, making the cleaning operation extremely easy. Furthermore, even when cleaning the CCD unit 20 or replacing the CCD unit 20, the position of the CCD 2 mounting member is accurately returned to its original position by the biasing force of an adjustment screw and a spring.
The structure is such that fine A adjustment due to dimensional variations in the unit 20 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 a position where it is removed from the elongated hole 62e, the right lever 62 is rotated around the sixth opening around the support shaft 64 due to the biasing force of the tension spring 61a. A bent portion of the lower arm portion 62f of the right lever 62 is brought into contact with the lower edge portion of the right side wall 50d of the movable base plate 50. As a result, the relative positions of the movable base plate 50 and the right lever 62 around the support shaft 64 are stabilized. Similarly, when the screw 69 screwed into the left side 1sob is removed from the elongated hole 63e of the upper arm 63d of the left lever 63,
The bent part of the lower arm 63f of the left lever 63 is the movable base plate 5.
0, the relative positions of the movable base plate 50 and the left lever 63 around the support shaft 64 are brought into a stable state. In this state, as shown in FIG.
The movable base plate 50 with the D unit 2o attached is attached to the right lever 6.
2. It can be rotated integrally with the left lever 63 to outside the projection optical path of the imaging lens 5, but its rotation range is limited to the screws 73 and 74 screwed into the right boss 81 and left boss 82, respectively. In contrast, the arc 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 this state, the arcuate hole 62g of the right lever 62 is in contact with the adjustment screw 83 that cooperates with the compression spring 65 to position the movable base plate 50 with the CCD unit 1-20 mounted thereon in the main scanning direction. The position and size of the circular arc hole 62g are set so that they do not come in contact with each other, so that no excessive force is applied to the adjustment screw 83, causing its position to shift or deform. ing. At this time, the movable base plate 5
The holding member (channel 31 in FIG. 3) of the CCD unit 2o, which is held so as to be adjustable in position relative to the movable base plate 5°, remains completely unchanged relative to the movable base plate 5°. After completing the necessary work such as cleaning and replacing the CCD 2 and the CCD 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 5o 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 50
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, a position yA adjustment mechanism that utilizes the steps of a screw is used to adjust the position of the COD with respect to the imaging lens, and to adjust the position vR of the imaging lens 5 and CCD 2 with respect to the original image exposure surface. has been done. 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 corner 138 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 71 made of a nylon ring 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 ring, the distal end portion of the nylon ring brake 71 is pressed against the adjustment screw 39 while undergoing compressive deformation, and the distal end portion 71a of the brake 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 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 adjustment screw 39 is
It is not moved in the radial direction of the screw. When rotating the adjusting screw 39 which has a male thread that engages with the female thread 38a, the square rod 38 and the movable base plate 5 change depending on the step of the adjusting screw 39.
The relative position of the adjustment screw 3 with respect to the upper surface 50i of the movable base plate 50 is adjusted due to the play in the engagement between the adjustment screw 39 and the female screw 38a.
The abutting position of the tip 39a of 9 does not shift. Furthermore, when the nylon ring brake 71 is plastically deformed as described above, elastic stress is generated within itself, so the brake 71
1 and the setscrew 72 are prevented from unintentionally loosening. Further, the braking force applied to the adjusting screw 39 by the pressing force of the brake element 71 does not change regardless of whether the adjusting screw advances or retreats, and can be further adjusted as necessary. In such a configuration, after the relative position between the movable base plate 50 and the square bar 38 is adjusted by moving the adjusting screw 39 back and forth, the set screw 72 is further screwed in, thereby further suppressing and deforming the brake element 71. Adjustment screw 39 is female thread 38
It is immovably locked with respect to a. In this case, the adjustment screw 39 will not be displaced from the female thread 38a by screwing in the set screw 72. Therefore, 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 adjusting screw 39 is rotated with its axial center position maintained at a predetermined position by the required suppressing force, and there is no damage to the threaded portion of the adjusting screw 39. Also, no indentation is caused, and therefore the smooth rotation of the adjusting screw 39 is not hindered in any way. The position adjustment device constituted by 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°. 6 [Effects of the Invention] As described above, according to the present invention, the photoelectric conversion element is rotated out of the imaging optical path by the opening/closing mechanism. This makes it easier to handle the photoelectric conversion element, making it easier to replace and clean the photoelectric conversion element, and
After replacement and cleaning. The opening/closing mechanism allows the photoelectric conversion element to be accurately positioned on the imaging optical path again.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view showing the main parts of the optical system of an apparatus in an embodiment of the present invention, and Fig. 2 shows a set of imaging lenses and C
Figure 3 is an explanatory front view showing a set of CCD reading units; Figures 4 and 5 (, ) are the CCD shown in Figure \. 5(b) is a front explanatory view showing the shape of the hole provided in the base plate; FIG. is C
FIG. 7 is a plan view showing the CCD positioning and fixing structure; FIG. 8 is a cross-sectional view taken along line A-A' in FIG. 7; 9 is a plan view showing another embodiment of the CCD positioning and fixing structure, FIG. 10 is a cross-sectional view taken along line BB' in FIG. 9, and FIG. 11 is a plan view showing another embodiment of the CCD positioning and fixing structure. FIG. 12 is an exploded perspective view showing a CCD fine adjustment structure, and FIG. 13 is a focus adjustment mounting structure for an imaging lens. FIG. 14 is a front explanatory view showing the reading unit shown in FIG. 3 removed from the base, and FIG. 15 is a cross-sectional view taken along line A-A' in FIG. 14. The explanatory drawings, FIG. 16 are cross-sectional explanatory views taken along the line BB' in FIG. 14, and FIGS. 17 and 18 are cross-sectional explanatory views showing the locking structure of the adjustment screw. 1.2.3...CCD, 4,5.6...Imaging lens, 12...JM draft, 13...Exposure line, 15...
・Reading unit, 20... COD unit, 31...
・Channel, 50...Movable base plate, 62...Right lever, 63...Left lever, 64...Spindle, 68.69.
...Adjustment screw, 80... Rotating base plate, 94... Conical shaft, 100... Base plate, 200... Base. (1 other person) v) q Cause F--β Riyashi Oσ] Ero 14 figure? 7i! l! 5iU figure 547 figure 4 figure 40 country'23 Ie day

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, the photoelectric conversion element is installed to be movable in the main scanning direction and rotatable around an axis extending in the main scanning direction, and the photoelectric conversion element includes: , a sliding biasing means for applying a biasing force in the main scanning direction and a rotational biasing means for applying a biasing force around an axis in the main scanning direction, and the rotational biasing means 1. A position adjustment mechanism for an image reading device, comprising an opening/closing mechanism for rotating a photoelectric conversion element onto and out of an imaging optical path by biasing and deenergizing a biasing force of a biasing means.