JP2517110B2 - Image reader position adjustment mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention photoelectrically converts a document image by moving a document image projected by an imaging lens and a photoelectric conversion element for reading the document image in the sub-scanning direction. The present invention relates to a position adjusting mechanism of an image reading device that is configured to read an image.

[Prior Art] In recent years, an optical image reading apparatus for an original image has been widely used as office equipment such as a copying machine and a facsimile. Generally, the size of the scanned original is limited to about A3 size,
In specific fields such as industrial drawings, the size of the target document is 841 mm wide (JIS A0 size) or 36 〃 (941 m
m) (ANSI E size). For such a large original, it is impossible to read the image by reducing and projecting it on one photoelectric conversion element (hereinafter referred to as CCD). It is not possible to make readings at a density.

Therefore, an apparatus has been proposed in which a large original image is divided and projected onto a plurality of CCDs by using a plurality of imaging lenses, and the image is read corresponding to each projected image.

[Problems to be Solved by the Invention] However, in such a split-type reading device, for example, the main scanning direction of each CCD perfectly matches the width direction of the original image, and the main pixel line of each CCD 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 the positioning is arranged so that the scanning direction is orthogonal to the optical axis. . Especially in high-density CCD linear sensors, which are used when high-density reading is required, it is necessary to perform highly accurate position adjustment in relation to the projection magnification for each CCD, the amount of read overlap, and temperature changes. I won't.

Conventionally, JP-A-51-51217 and JP-A-59-201572
JP, JP-A-59-201575, or JP-A-62-27
Although various types of CCD support structures have been proposed in Japanese Patent Publication No. 7852, etc., all of them are related to the technology for adjusting the perpendicularity between the original image and the optical axis of the imaging lens and the optical axis of the imaging lens.
It does not disclose the technology to adjust the squareness of CCD pixel rows,
It does not fully meet the demands mentioned above.

The present invention makes it possible to adjust the orthogonality between the photoelectric conversion element and the optical axis of the imaging lens with high accuracy, and when finely moving the position of the CCD in the main scanning direction, the pixel row of the CCD and the imaging lens. It is an object of the present invention to provide a position adjusting mechanism of an image reading device capable of maintaining the perpendicularity with respect to the optical axis of the device with high accuracy.

[Means for Solving the Problems] In order to achieve the above object, the present invention projects a document image on a photoelectric conversion element by an imaging lens, and the document image and the photoelectric conversion element are relatively arranged in the sub-scanning direction. In a position adjusting mechanism of an image reading device that is moved to photoelectrically read the original image, a lens unit having a lens barrel moving mechanism that moves the imaging lens in the optical axis direction, and a lens unit that is parallel to the optical axis. A first support shaft arranged in the sub-scanning direction and orthogonal to the first support shaft,
A second support shaft rotatable around an axis orthogonal to the first support shaft and around the first support shaft, and a base end portion of the second support shaft are provided on the first support shaft, and a free end portion of the second support shaft is provided. A first holding member extending in a main scanning direction orthogonal to the sub-scanning direction and having a surface substantially orthogonal to the optical axis, and a base end portion of the first holding member includes a first support shaft and a second support member. A second holding member for holding the photoelectric conversion element, which is provided on the second support shaft across the intersection with the shaft, and has a free end portion extending to face the first holding member; The second holding member extends in the main scanning direction and is rotatable about an axis in the main scanning direction via a first holding member and is slidably supported in the axial direction of the main scanning direction. And a lens holder for rotatably supporting the third support shaft and the lens unit around an axis that is orthogonal to the optical axis in the sub-scanning direction and supports the third support shaft. Board A base plate for supporting the rotary base plate so as to be rotatable around an axis orthogonal to the optical axis in the sub-scanning direction, and a position for holding the base plate and reading the original image. On the other hand, it is characterized by comprising a base arranged immovably in the main scanning direction and an optical axis direction moving mechanism for moving the base plate in the optical axis direction with respect to the base. .

[Operation] According to the present invention, the second holding member of the photoelectric conversion element is rotatable about the first support shaft, the second support shaft, and the third support shaft by the means having the above-described configuration. Therefore, fine adjustment is possible around the optical axis of the imaging lens, the axis in the sub-scanning direction, and the axis in the main scanning direction, which are orthogonal to each other. The rotation base plate supports the lens unit so as to be rotatable about an axis in the sub-scanning direction that is orthogonal to the optical axis, and is also capable of rotating the second holding member via the first holding member. And a third support shaft slidably supported in the main scanning direction. Further, the base plate supports the rotary base plate so as to be rotatable about an axis that is in the sub-scanning direction and that is orthogonal to the optical axis. Further, since the base, which is arranged immovably in the main scanning direction with respect to the reading position of the original image, holds the base plate, the position of the photoelectric conversion element can be slid and adjusted in the main scanning direction. However, when adjusting the rotational movement in the sub-scanning direction, the perpendicularity between the optical axis of the imaging lens and the pixel row of the photoelectric conversion element can be finely adjusted with high accuracy.

[Examples] Hereinafter, examples of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, the original 12 is illuminated by the elongated illumination lamp 11, so that the image on the original 12 is exposed by the three imaging lenses 4, 5 and 6 in the exposure line 13, respectively. One-dimensional photoelectric conversion element (hereinafter simply “CCD”)
It will be abbreviated as ").

The respective light fluxes 7, 8, 9 in the imaging lenses 4, 5, 6 have predetermined areas l ₁₂ -l ₂₃ overlapped in the exposure line 13, and the read signals by the CCDs 1, 2, 3 are shown in the figure. It is controlled so as not to cause omission, duplication, shift, etc. at a predetermined position in each overlapping area when the data is output to the omitted writing device.

The original 12 is conveyed in the direction of the arrow shown in the drawing from the front end to the rear end of the exposure line 13 on the transparent flat glass plate by a conveying means (not shown) at a speed corresponding to a predetermined reading speed. With this, the entire image of the original can be read.

Further, as shown in FIG. 2, the area l ₂ on the exposure line 13 of the original 12 is reduced to 0.1102 times by the imaging lens 5 and imaged on the pixel array of the CCD 2. There is. CCD2 has 5000 pixels of 7 μm x 7 μm (picx
el), and the length of the pixel array is
It is set to 35 mm. Therefore, the length of the region l ₂ is 317.5 mm.

In this way, in order to read the image of the document 12 by dividing it by the plurality of CCDs 1, 2, and 3, the read magnification, position, range, etc. of the read image in each CCD 1, 2, 3 are positioned with predetermined accuracy. There is a need. Therefore, in this embodiment, the second
As shown in the drawing, the position of the CCD 2 is finely adjusted in parallel with each of 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. In addition to being movable, the X-axis direction, Y-axis direction, Z
Rotational fine adjustment movement is possible around each axis in the axial direction.

As shown in FIGS. 3, 4 and 5,
The reading unit 15 is a base plate 100 having a U-shaped cross section, which is mounted on the base 200 so as to be capable of fine adjustment in parallel in the optical axis direction (Z-axis direction) of the imaging lens 5, and the base plate 100. With respect to the optical center of the imaging lens 5, a rotary base plate 80 mounted at a right angle to the optical axis about a conical shaft 94 having an axis in each sub-scanning direction so as to be finely adjustable, and A shading correction plate 97, which is screwed to an upper side wall 80d of the rotating base plate 80 so as to be movable in a direction orthogonal to the optical axis, and an image forming lens 5 at a substantially center of a front side wall 80c of the rotating base plate 80. Optical center, conical axis that is perpendicular to the optical axis and has an axis in the sub-scanning direction
A lens unit 300 screwed around 94 for fine adjustment of rotation, and a right side wall 80a and a left side wall 80 of the rotation base plate 80.
Right boss 81 and left boss 82 screwed to the bottom of b
A support shaft 64 as a third support shaft that is hung between
The CCD base plate unit 30 is mounted on the support shaft 64 so as to be finely rotatable and finely slidable in the axial direction.

The CCD base plate unit 30 holds the CCD unit 20, and between the CCD unit 20 and the lens unit 300, a seal body 310 having a light-shielding property, a dust-proof property, and a breathability is mounted. .

Further, as shown in FIGS. 14, 15 and 16, the base 200 is provided with a left support frame 230 and a right support frame which are provided as members immovable with respect to the exposure line 13 of the original image. It is rotatably supported by 231 via a left main shaft 215 and a right main shaft 217. This 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 the main scanning direction of the CCD, that is, the exposure. Line 13
It has an axis in a direction parallel to. Also above left spindle 215
Two stop shafts 214 are provided on both sides in the direction orthogonal to the axis of the base 200. By tightening or loosening each of the stop shafts 214 with the set screws 222 and 223, the base 200 can be finely adjusted for rotation. Has become.

As shown in FIGS. 7 and 8, the CCD 2 of the CCD unit 20 is fitted into a substantially rectangular positioning hole 21g provided in the metal plate 21. Positioning hole 2 above
At the edge of 1g, three support pieces are formed so as to project inward, and a main scanning direction reference edge 21a and a sub-scanning direction reference edge 21b formed at the tip of each of these support pieces. The end faces in the main scanning direction and the end faces in the sub scanning direction of the ceramic case of the CCD 2 are brought into contact with and held by 21 and 21c, respectively. Further, the main scanning direction reference edge 21a and the sub-scanning direction reference edges 21b, 21c are accurately positioned with respect to the two mounting holes 21e provided in the metal plate 21,
As a result, the pixel row 2a of the CCD 2 is positioned with a predetermined accuracy. At this time, cover glass 2b of CCD2
Then, the upper surface of the metal plate 21 is positioned in the same plane. Furthermore, a two-part epoxy resin is injected and cured in the gap between the ceramic case of the CCD 2 and the positioning hole 21g to make the CCD 2 immovable.

Further, the CCD control plate 22 including an amplifier circuit for amplifying the image reading signal by the CCD 2 is soldered and held to 22 connection pins 2c of the CCD 2. Two connectors 23 are soldered to the CCD control plate 22, and a flat cable 24 composed of a plurality of lead wires is detachably attached to each. In the mounting hole 22a provided in the CCD control plate 22, the CCD2
The thermistor 25 that detects the temperature of
It is designed to be adhered and held by epoxy resin while being in contact with the D2 ceramic case.

Furthermore, a connector 23 is soldered to the CCD control board 22, and a flat cable is connected to this connector 23.
One end of 24 is plugged. Above flat cable
The other end of 24 is inserted and connected to a connector 401 soldered to a CCD control plate 400 (see FIGS. 3 and 5). The CCD control plate 400 constitutes a drive control circuit of the CCD 2, and is larger than the CCD control plate 22 and has more control electronic components mounted thereon.
The fever is also large. Therefore, this CCD control board 400 is
It is desirable to install the CCD as far as possible from each other.In this embodiment, the CCD is locked by screws 403 and 404 to the right support leg 100d and the left support leg 100e extending downward from the base plate 100. The heat generated by the control plate 400 does not affect the CCD2.

When the CCD control plate 22 and the CCD control plate 400 which are separated from each other in this way are connected by the flat cable 24, electrical noise is picked up through the flat cable 24 and an accurate signal corresponding to the original image is output. Therefore, in the present embodiment, as described above, the CCD control plate 22 directly connected to the CCD 2 is provided with the read signal amplifying function, which causes the influence of electrical noise. I try to minimize it. As a result, the flat cable 24 can be lengthened to some extent, which alleviates the positional restriction of the CCD control plate 400, and even if the CCD2 is adjusted in a relatively large range, the CC
The connection failure between the flat cable 24 and the connectors 23, 401 can be eliminated without applying an excessive force to D2.

9 and 10 show another mounting structure of the CCD2. That is, at the edge of the positioning hole 21g, in addition to the main scanning direction reference edge 21a and the sub scanning direction reference edges 21b and 21c, three optical axis direction reference edges 21f are provided, and these optical axis direction reference edges 21f are provided. The cover glass 2b of the CCD 2 is positioned in contact with the 21f. Then, a two-part epoxy resin is injected and hardened in a gap portion 21d between the ceramic case of the CCD2 and the positioning hole 21g so that the CCD2 is made immobile. By doing so, the positioning of the CCD 2 with respect to the metal plate 21 in the optical axis direction can be facilitated.

Further, FIG. 11 shows another mounting structure of the CCD control plate 22. That is, the socket 26 is soldered to the CCD control plate 22 via the connection pin 26a,
The connection pin 2c of the CCD 2 is inserted into the socket 26. In this way, the CCD2 can be replaced by inserting the connection pin 2c of the CCD2 into the socket 26, or
The CCD control plate 22 can be replaced easily and inexpensively.

Next, the lens unit 300 will be described with reference to FIG. 13, FIG. 5 and FIG. The lens holder 301 has a substantially L-shaped cross section.
The lens holder 301 is formed of an upright aluminum casting, and three convex portions 301e are formed on the rear portion 301b of the lens holder 301, and mounting holes 303 are formed in the rotary base plate 80. . The projecting tip flat surface portion of the convex portion 301e and the holder lower surface portion 301d are cut so as to have an orthogonal relationship, and further, with the both surfaces 301e and 301d as a reference, a fitting for accommodating the imaging lens 5 is performed. The hole 304 is formed so as to penetrate in the optical axis direction. That is, the fitting hole 304
The axis of is accurately positioned with respect to the perpendicularity to the holder lower surface portion 301d of the lens holder 301 and the parallelism with the protruding tip flat surface portion of the convex portion 301e. The imaging lens 5 is fitted and inserted in the fitting hole 304 so as to reciprocally slide in the optical axis direction.

A fitting hole 302 is formed in the rear part 301b of the lens holder 301 so as to be fitted to the outer peripheral part of the cylindrical female screw 95. The cylindrical female screw 95 locks the conical shaft 94 to the front wall 80c of the rotary base plate 80. At this time, the fitting hole 302
Is formed on the optical center of the imaging lens 5 and is accurately set in a direction orthogonal to the lens optical axis and orthogonal to the protruding tip flat surface portion of the convex portion 301e. On the other hand, a movable base plate 50 that holds the CCD base plate unit 30 is rotatably and slidably supported on the support shaft 64, but has a fitting hole.
The lens unit 300 is rotationally adjusted about 302, and the holder lower surface 301d is set to be parallel to the support shaft 64, and then locked to the rotary base plate 80 by the three screws 309. It is like this. As a result, the optical axis and the support axis of the imaging lens 5
The required right angle accuracy between 64 and 64 will be guaranteed.

Further, the tip end portion of the leaf spring 325 screwed to the front portion 301a of the lens holder 301 is in pressure contact with the upper edge portion of the imaging lens 5, whereby the imaging lens 5 moves downward in the optical axis direction. It is designed to be pressed. A fitting hole 305 is formed in the front portion 301a of the lens holder 301 in a direction orthogonal to the lens optical axis, and the imaging lens 5 is finely adjusted and moved in the fitting hole 305 in the optical axis direction. The focus adjusting shaft 306 for focusing and locking is rotatably dried. Further, a screw hole 301f is formed in the front portion 301a of the lens holder 301 so as to be orthogonal to the axis of the fitting hole 305, and the pressure rod 307 loosely fitted in the screw hole 301f is a set screw. By being pressed by 308, the focus adjusting shaft 306 is pressed in the direction perpendicular to the axis, whereby the focus adjusting shaft 306 is locked at a predetermined position as described later. The pressure bar 307 is made of a flexible hard resin.

On the other hand, a groove 322 having a predetermined depth is formed in an annular shape on the outer peripheral portion of the lens barrel 321 of the imaging lens 5, and a cylindrical eccentric cam 306 is formed on the rear end of the focus adjusting shaft 306.
a is formed, and this eccentric cam 306a is engaged in the groove 322. The eccentric cam 306a is formed with a diameter of 8 mm, is eccentric to the axis of the main shaft 306c of the focus adjusting shaft 306 by 1.5 mm, and has an axial length longer than the depth of the groove 322. The main shaft 306c of the focus adjustment shaft 306 has a diameter of 1
It is formed in a cylindrical shape of 2 mm, and a conical portion 306d with an apex angle of 90 ° is formed on the opposite side of the eccentric cam 306a, and this conical portion 306d is integrated with the auxiliary shaft 306f via the small diameter shaft 306e. Are linked to. The auxiliary shaft 306f is formed to have the same diameter as the main shaft 306c, and a slit portion 306g that allows a driver to be fitted is formed on an end surface portion of the auxiliary shaft 306f. The conical portion 307a formed at the tip portion of the pressure rod 307 described above is pressed against the conical inclined side surface of the conical portion 306d. The component forces P ₁ and P ₂ of the pressing force of the pressure rod 307 at these pressure contacts are directed in the axial direction of the focus adjustment shaft 306 and the direction orthogonal to the axis, respectively, and the axial component force P ₁
Therefore, the tip surface 306b of the eccentric cam 306a becomes the groove bottom surface 322 of the groove 322.
The lens barrel 321 is pressed against a and is pressed against the wall surface of the fitting hole 304, so that the lens barrel 321 is maintained in a play-free state. The focal adjustment shaft by a shaft perpendicular direction component force P ₂ 30
The six main shafts 306c and the auxiliary shafts 306f are pressed against the wall surface of the fitting hole 305 to maintain a play-free state, and the rotation of the focus adjustment shaft 306 is braked by frictional force. At this time, the pressing force on the groove bottom surface 322a by the tip 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. But at least depending on the imaging lens 5
When focusing the projected image on the CCD2, the lens barrel 321
The frictional force between the fitting hole 304 and the fitting hole 304 causes the leaf spring against the lens barrel 321.
Pressurizing rod 307 does not exceed the pressing force of 325.
The pressing force from the set screw 308 to the is adjusted.

As described above, the lens barrel moving mechanism that moves the image forming lens 5 in the optical axis direction includes the fitting holes 304 and 305 and the focus adjusting shaft 30.
6, the eccentric cam 306a, and the groove 322 of the lens barrel 321 are mainly configured.

To adjust the focus of the imaging lens 5, first, a driver is engaged with the slot portion 306g to rotate the focus adjusting shaft 306. 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 focus of the projected image on the CCD 2 is adjusted. At this time, the pressing force of the plate spring 325 prevents the imaging lens 5 from rotating around the optical axis, and the groove side surface 322b of the groove 322 is also prevented.
The state in which is pressed against the cam surface of the eccentric cam 306a is maintained. As a result, the imaging lens 5 is always movable in the finest direction for reading the original image, that is, in the main scanning direction to eliminate the defocusing in the main scanning direction. It is designed to be kept play-free. After the focus adjustment is completed, the set screw 308 is further screwed in to increase the axial component force P ₁ and the axial orthogonal component component P ₂ so that the imaging lens 5 is not displaced with respect to the lens holder 301. The focus adjustment shaft 306 is reliably locked and the rotation of the focus adjustment shaft 306 is stopped.

Next, the CCD2 position adjusting mechanism will be described with reference to FIGS.
This will be described with reference to FIGS. 5, 5, 12, 17 and 18.

First, in the inclination of the CCD 2 in the X-axis direction which is the main scanning direction, that is, the rotation fine adjustment mechanism of α around the Y axis and the rotation fine adjustment mechanism of γ around the Z axis which is the optical axis direction of the imaging lens 5,
As mentioned above, a metal plate that holds the CCD 2 at a fixed reference position.
The CCD unit 20 having 21 is fixed by screwing a flat head screw pin 32 on two circular pedestals 31d formed on the upper surface of the channel 31 corresponding to the two reference mounting holes 21e. As a result, the CCD 2 can be easily replaced within the displacement range of 200 to 300 μm. The CCD control plate 22 described above is positioned so as to project downward from the rectangular mounting hole 31a formed in the channel 31.

On the lower surface side of the right end portion of FIG. 12 in the X-axis direction of the channel 31, a horizontal axis as a second support shaft having a substantially columnar shape.
33 is attached so as to extend in the Y-axis direction. Both ends of the horizontal shaft 33 are cut out in a substantially semi-cylindrical shape, and the flat surface portion of the semi-cylindrical cutout portion 33c is brought into contact with the lower surface side of the channel 31 so that the semi-cylindrical cutouts on both sides are formed. part
It is fastened and fixed by a countersunk screw 34 through a pair of female screws 33c formed on 33d. Further, two conical portions 33a are formed in the central portion of the horizontal shaft 33 so as to face each other, and both conical portions 33a are formed in the channel 31 to form a rectangular notch 31c. It is housed inside. On the other hand, on the upper surface side of the right end portion of the movable base plate 50 in FIG. 12 in the X-axis direction, a vertical axis 35 as a first support shaft is erected in the Z-axis direction (optical axis direction). A male screw 35b is formed on the lower portion of the vertical axis 35, and this male screw 35b is formed so as to penetrate the upper surface 50a of the movable base plate 50. It is fastened to the upper surface 50a of the plate 50. On the upper end portion of the vertical axis 35, a lower outer peripheral edge portion 35a of a cylindrical portion having a diameter larger than that of the middle portion is formed. The lower outer peripheral edge portion 35a is in contact with the conical inclined side surfaces of the two conical portions 33a of the horizontal shaft 33. As a result, the entire channel 31 including the CCD unit 20 can be rotated about the horizontal axis 33 and the vertical axis 35.

A square bar 38 is fastened and fixed by two countersunk screws 41 to the left end portion of the channel 31 in the X-axis direction in FIG. 12, and an adjusting screw 3 is inserted into a screw hole 38a provided in the square bar 38.
9 is screwed. This adjusting screw 39 is
It protrudes downward through a large-diameter hole (not shown) formed in, and its spherical tip portion 39a is in contact with the upper surface 50i of the movable base plate 50 having the U-shaped cross section described above.

On the other hand, stepped pins 36a and 36b are provided on the front side wall 31e and the rear side wall 31f of the channel 31 in the Y-axis direction.
8 stepped pins 3 each screwed into the vicinity
The upper ends of tension springs 37a and 37b are hooked on 6a and 36b, respectively. The lower ends of the tension springs 37a and 37b are hooked on the stepped pins 54a and 54b screwed to the front side wall 50g and the rear side wall 50h of the movable base plate 50, respectively. These tension springs 37a and 3
7b extends obliquely so as to form an angle of about 45 ° with respect to the Z axis (optical axis), and its pulling force causes the channel 31 to move downward and rightward in FIG. 12 inside the vicinity of the square rod 38. The component force of pressing is generated. Then, the lower outer peripheral edge portion 35a of the columnar portion of the vertical axis 35 is formed into a conical shape of the two conical portions 33a formed on the horizontal axis 33 by the rightward component force of the pulling springs 37a and 37b. While being pressed against the inclined side surfaces, the lower side surfaces of the cylindrical portions 33b at both ends of the horizontal shaft 33 are pressed against the upper surface 50a of the movable base plate 50 by the downward pressure component force of the extension springs 37a and 37b. ing. As a result, the entire channel 31 including the CCD unit 20 is held in a three-point supported state by the vertical axis 35 and the movable base plate 50 via the horizontal axis 33.
Further, the adjusting screw 39 screwed to the square rod 38 is provided by the downward force component of the tension springs 37a and 37b.
The spherical tip portion 39a of this is pressed against the upper surface 50i of the movable base plate 50. Therefore, by rotating the adjusting screw 39, the channel 31 is rotated around the Y axis about the horizontal axis 33, that is, in the α direction and positioned.

At this time, since the stepped pins 36a and 36b are arranged between the horizontal shaft 33 and the adjusting screw 39 and in the vicinity of the adjusting screw 39, the stepped pins 36a and 36b are provided under the cylindrical portions 33b on both end sides of the horizontal shaft 33. The side surface is biased so as to be pressed against the upper surface 50a of the movable base plate 50 more strongly, and the two are brought into close contact with each other without being separated from each other. The biasing force applied to the stepped pins 36a and 36b by the tension spring 37a and the tension spring 37b is set so as not to prevent the channel 31 from rotating around the vertical axis 35.

Further, a spring hook portion 31g is formed so as to project from the left end portion of the channel 31 in the X-axis direction in FIG. 12, and a tension spring is pulled in a hole 31h provided in the spring hook portion 31g.
One end of 40 is hung. On the other hand, a square bar 51 is fixed to the side surface of the movable base plate 50 with screws.
The other end of the tension spring 40 is hooked on the stepped pin 52 standing upright. Due to the biasing force of the tension spring 40, the entire channel 31 is rotated toward the front side about the vertical axis 35. An adjusting screw 53 is screwed into a screw hole 51a provided in the square rod 51, and a spherical tip portion 53a of the adjusting screw 53 abuts on the front side wall surface 31e of the channel 31 in the Y-axis direction. Has been done. Therefore, by rotating the adjusting screw 53, the channel 31 is rotated about the Z-axis, that is, in the γ direction about the vertical axis 35 to be positioned.

With the fine adjustment mechanism having such a configuration, inclination in the X-axis direction that is the main scanning direction, that is, fine adjustment of rotation in the α direction about the Y axis and fine rotation in the γ direction around the Z axis, which is the optical axis direction of the imaging lens 5. The adjustment is accurate. That is, first, by rotating the adjusting screw 39, the tension springs 37a, 37a
The channel 31 is rotated about the horizontal axis 33 in opposition to b, whereby the CCD 2 is positioned in the α inclination direction. At this time, since the rotation center position and the adjustment action position are separated from each other, fine adjustment can be performed without using a complicated mechanism such as a differential screw. When adjusting the tilt with this adjusting screw 39,
Adjusting screw 5 on the side wall surface 31e on the front side of the channel 31 in the Y-axis direction
Although the spherical tip end portion 53a of 3 is slid while being in contact, since the squareness of the front side wall surface 31e of the channel 31 with respect to the horizontal axis 33 is maintained at a required accuracy, the sliding movement described above is performed. Due to this, the channel 31 is hardly rotated around the vertical axis 35, and there is no trouble in adjustment. The horizontal axis 33 is
Since the CCD 2 is provided at a position sufficiently separated from the CCD 2, the CCD 2 is hardly displaced in the X-axis direction which is the main scanning direction when the CCD 2 is adjusted in the α inclination direction.

On the other hand, by rotating the adjusting screw 53, the tension spring
The channel 31 is rotated about the vertical axis 35 in the γ direction around the Z axis in opposition to 40 for positioning, and the parallelism of the pixel row of the CCD 2 with respect to the exposure line 13 shown in FIG. 2 is adjusted. It is supposed to be done. Also in this case, since the rotation center position and the adjustment action position are separated from each other, fine adjustment can be performed without using a complicated mechanism such as a differential screw. During the rotation adjustment by the adjusting screw 53, the spherical tip portion 53a of the adjusting screw 39 is slid while being in contact with the upper surface 50i of the movable base plate 50, and the horizontal shaft 3
The cylindrical portion 33b of 3 is slid while being in contact with the upper surface 50a of the movable base plate 50, but the perpendicularity of the upper surfaces 50i and 50a of the movable base plate 50 to the vertical axis 35 is the required accuracy. Since it is maintained at
It is hardly rotated around 33, and there is no obstacle in adjustment. Further, since the vertical axis 35 is provided at a position sufficiently separated from the CCD2, the CCD2 is almost always displaced in the X-axis direction which is the main scanning direction when adjusting the CCD2 around the Z-axis in the γ direction. Absent.

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 described.

Square bars 55 and 57 are attached to a rear side wall 50h of the movable base plate 50 in the Y-axis direction, and adjustment screws 56 and 58 are screwed to the square bars 55 and 57. Adjusting screw 56 above,
The tip end portion of 58 is formed in a spherical shape, and the spherical tip end portions 56a, 58a are in contact with the front wall 80c of the rotating base plate 80.

On the other hand, fitting holes 50f are respectively formed through the right side wall 50d and the left side wall 50e of the movable base plate 50 in the X-axis direction, and these fitting holes 50f respectively include a right boss 81 and a left boss described later. A support shaft 64, which has been scorched between it and 82, is fitted in such a manner that it can slide and rotate freely. Further, as shown in FIG. 4 in particular, L-shaped plates 59 and 60 are screwed to the upper sides of the right side wall 50d and the left side wall 50e, respectively. In addition,
In addition to the structure around the right lever 62, the structure around the left lever 63 is shown in FIG. 4 with appropriate parentheses. One ends of tension springs 61a and 61b are attached to holes 59a and 60a formed at the tip ends of the L-shaped plates 59 and 60, respectively. Further, as shown in FIGS. 3 and 4, the support shaft 64 includes a right lever 62 and a left lever 63.
Is rotatably mounted. Fitting holes 62a and 63a are formed in the right lever 62 and the left lever 63, and a support shaft 64 is mounted in these fitting holes 62a and 63a. The right lever 62 and the left lever 63 are movable base plates.
By engaging the locking screws 68 and 69 in the long holes 62e and 63e formed in the upper arm portions 62d and 63d, which are arranged outside the right side wall 50d and the left side wall 50e, respectively. The rotations of the right lever 62 and the left lever 63 with respect to the support shaft 64 are each stopped. The locking screws 68 and 69 are provided on the right side wall 80 of the rotary base plate 80.
They are respectively screwed so as to penetrate the a and the left side wall 80b in the X-axis direction.

Further, the middle arm portion 62b extending in the direction orthogonal to the upper arm portions 62d and 63d, that is, toward the front wall 80c of the rotating base plate 80.
And 63b have holes 62c and 63c formed therein, and the tension springs 61a and 6c described above are formed in these holes 62c and 63c.
The other end of 1b is hung. In the state shown in FIG. 4, the tension springs 61a and 61b are urged. The movable base plate 50 is about to be rotated clockwise in FIG. 4 due to the urging force of the tension springs 61a and 61b, but the spherical tip portions 56a and 58a of the adjusting screws 56 and 58 are the front wall 80c of the rotation base plate 80. It is supposed to be stopped by being pressed against it. In FIG. 4, the tension spring 61a
The hole 59a to which one end is hooked is the point of urging force of the tension spring 61a, and the support shaft 64 is the fulcrum. Then, the tension spring 61a applies the tension force in the diagonally right downward direction in the figure at the force point, and the force point and the fulcrum are perpendicular to the upper surfaces 50a, 50i of the movable base plate 50 in the figure. is there. Therefore, the tension spring 61a is extended so that its urging force produces a component force in the tangential direction and the normal direction about the support shaft 64, which causes the movable base plate to move.
The 50 is pressed and urged by the support shaft 64 to be held at a fixed position.

Next, a configuration relating to maintenance and replacement of the CCD unit 20 will be described with reference to FIG. In addition, in the same drawing, in addition to the configuration around the right lever 62, the configuration around the left lever 63 is added with parentheses as appropriate. As described above, normally, the right lever 62 cannot rotate around the movable base plate 50 via the support shaft 64, but when the CCD unit 20 is replaced for maintenance, the right lever 62 is for locking. Rotating base plate with screws 68
It can be rotated by removing it from the right side wall 80a of 80. A lower arm portion 62f is integrally formed at a lower portion of the right lever 62, and a bent portion provided on the lower arm portion 62f abuts a lower edge portion of the right side wall 50d of the movable base plate 50. Has been done.
Then, the CCD unit 20 is used for maintenance replacement, etc.
The tension spring 61a is in a predetermined deenergized state when it is rotated to the front side to the state shown in FIG.
It is designed to be held so that it will not fall off. 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 so as to face each other. An adjusting screw 83 is pierced through 62g in a non-contact state, and locking screws 73, 74 are loosely fitted in the other arcuate holes 62h and 63h.

The position adjustment fine adjustment in the Y-axis direction which is the sub-scanning direction is accurately performed by the fine adjustment mechanism having such a configuration. That is, by rotating the adjusting screws 56 and 58, the movable base plate 50 is rotated around the support shaft 64 against the tension springs 61a and 61b, so that the CCD 2 is positioned in the Y-axis direction. Has become. At this time, since the rotation center position and the adjustment action position are separated from each other compared to the distance between the rotation center position and CCD2, fine adjustment can be performed without using a complicated mechanism such as a differential screw. be able to. The movement adjustment operation in the sub-scanning direction by the adjustment screws 56, 58 is performed by a rotation operation about the support shaft 64. However, the CCD 2 is arranged apart from the support shaft 64, and the position adjustment Since the amount of movement is 1 to 2 mm, there is no problem because the displacement of the CCD 2 in the sub-scanning direction in the inclination β direction is extremely small. Further, the pixel size is extremely small as in this embodiment (7 μm × 7 μm).
When a linear sensor is used, the slight inclination β of the pixel row in the sub-scanning direction does not hinder the reading of the projected image. Rather, it is preferable to slightly tilt the CCD 2 in the sub-scanning direction with respect to the optical axis, because re-projection of the reflection image of the projection image of the CCD 2 by the cover glass 2b on the pixel column is avoided.

Further, fitting holes 81a and 82a are respectively formed through the center portions of the right boss 81 and the left boss 82 screwed to the right side wall 80a and the left side wall 80b of the rotating base plate 80, respectively. Both ends of the support shaft 64 are fitted into the fitting holes 81a and 82a, and the set screws 81b and 8
Locked by 2b. Further, a compression spring 65 is fitted to the outside of the support shaft 64. One end portion of the compression spring 65 is supported on the inner surface of the right side wall 50d of the movable base plate 50, and the other end portion of the compression spring 65 is fixed so as to penetrate the support shaft 64. The pin 67 is pressed against the pin 67 via a washer 66 and locked, so that the movable base plate 50 is pressed and biased toward the right direction in FIG. On the other hand, the right boss 81 has an adjustment screw
The adjusting screw 83 is screwed so as to penetrate therethrough, and the spherical tip portion 83a of the adjusting screw 83 is brought into 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 pressed against the spherical tip portion 83a of the adjusting screw 83 by the moving force of the movable base plate 50 by the compression spring 65. Therefore, by rotating the adjusting screw 83, the movable base plate 50 is moved in the main scanning direction. The screw pitch of the adjusting screw 83 is set to 0.5 mm so that the adjusting operation can be performed extremely easily. In the main scanning direction (X-axis direction) adjusting operation of the CCD 2 by the adjusting screw 83,
The position of the CCD 2 does not shift in the sub-scanning direction (Y-axis direction), the main-scanning tilt direction (α direction), the optical axis rotation direction (γ direction), or the Z-axis direction. this is,
The perpendicularity between the support shaft 64 and the optical axis of the imaging lens 5 is adjustable with an accuracy of ± 1 ′, and the parallelism of the support shaft 64 with respect to the exposure line 13 of the original image is also ± 1 ′. The accuracy is maintained and the movable base plate 50 has a tension spring 61.
This is because the urging force of a and 61b presses the support shaft 64 in the radial direction, and at the same time, the position of the movable base plate 50 is maintained by the front wall 80c of the rotary base plate 80 via the adjusting screws 56 and 58. . Further, as in this embodiment, since the support shaft 64 is arranged with a sufficient space (180 mm) with respect to the size (35 mm) of the pixel row 2a of the CCD 2, the right boss that supports the support shaft 64 is provided. Even if the positional accuracy of the 81 and the left boss 82 in the sub-scanning direction (Y-axis direction) is normal processing accuracy (for example, about ± 0.1 mm), when the position adjustment amount of the CCD 2 in the main-scanning direction X is 2 mm, the sub-scanning direction (Y-axis direction). There is no adjustment bearing.

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 described.

As shown in FIGS. 3, 4 and 5,
A hole 96 is formed in the central portion of the front wall 80c of the rotating base plate 80 so as to be the optical center of the imaging lens 5 and orthogonal to the optical axis of the imaging lens 5. The conical shaft 94 is fitted and inserted, and the conical shaft 94 is fastened by a female internal thread 95 and fixed at a right angle to the front wall 80c. Further, the rotating base plate 80 is arranged so as to face the front wall 100a of the base plate 100 formed in a U-shaped cross section, and the front wall 100a of the base plate 100 is arranged.
The large diameter side of the conical shaft 94 penetrates through the arcuate hole portion 120a of the engaging hole 120 (see FIG. 5B) provided in the base plate 100 and projects inside. At this time, the engaging hole 120
The arcuate hole portion 120a is formed to be smaller than the maximum diameter of the conical portion of the conical shaft 94 and larger than the minimum diameter,
The conical inclined surface 94a of the conical shaft 94 is the arcuate hole portion 120a of the engaging hole 120.
Is engaged. As a result, the front wall 100 of the base plate 100 is
The rotation base plate 80 is configured to be rotatable around the conical shaft 94 with respect to a.

On the other hand, a pedestal 101 is welded to the right side portion of the front wall 100a of the pedestal 100 in FIG. 3, and the adjustment screw 102 is screwed into the screw hole formed in the pedestal 101 so as to penetrate therethrough. There is. The spherical tip portion 102a of the adjusting screw 102
Is a square bar 9 welded to the right side wall 80a of the rotating base plate 80.
It is in contact with the upper surface 90a of 0. Further, a stepped pin 93 is erected on the left side portion of the front wall 100a of the base plate 100 in FIG. 3, and a stepped pin 91 is erected on the left side wall 80b of the rotating base plate 80. Cage, these stepped pins 93
A tension spring 92 is hung between the step pin 91 and the stepped pin 91. As a result, the rotating base plate 80 is urged to rotate counterclockwise in FIG. 3 about the conical shaft 94 with respect to the front wall 100a of the base plate 100, and the right side wall 80a of the rotating base plate 80 is rotated. The upper surface 90a of the square bar 90 welded to the base plate 80 is pressed against the spherical tip portion 102a of the adjusting screw 102, and the rotation base plate 80 is stopped.

At this time, the conical shaft 94 is pressed and urged in a downward direction orthogonal to the conical shaft 94, but as described above, the conical inclined surface 94a of the conical shaft 94 has the arc hole 120a of the engaging hole 120. When the conical shaft 94 is engaged with the conical shaft 94, the conical shaft 94 receives a component force to the left in FIG. 5, and the rotating base plate 80 is pressed against the base plate 100 side by this component force. Further, on the front wall 100a of the base plate 100,
Three circular pedestals 100f are formed on the circumference centered on the conical shaft 94 at equal pitches of approximately 120 °, and on the circular pedestals 100f, the outer surface of the front wall 80c of the rotary base plate 80 is formed. Are brought into contact with each other to support the rotary base plate 80 at three points, whereby the rotary base plate 80 can be stably rotated. Further, on the front wall 80c of the rotary base plate 80, three elongated holes 84, 85, 8 are formed on the circumference centered on the conical shaft 94 at an equal pitch of about 120 °.
6 is formed, and set screws 87, 88, 89 penetrating these elongated holes 84, 85, 86 are screwed to the front wall 100a of the base plate 100 so that the rotating base plate is fixed. Has become.

Therefore, if the adjusting screw 102 is rotated while the set screws 87, 88, 89 are loosened, the rotating base plate 80 is rotated around the conical shaft 94, and the original on the optical axis of the imaging lens 5 is rotated. Exposure line
The squareness in the main scanning direction with respect to 13 is adjusted. In the operation of adjusting the perpendicularity of the optical axis by the adjusting screw 102, the position of the CCD 2 with respect to the optical axis of the imaging lens 5 is the main scanning direction (X axis direction), the sub scanning direction (Y axis direction), and the main scanning tilt direction. (Α direction), optical axis rotation direction (γ direction) or Z
No deviation occurs in any of the axial directions. Further, the three-point support structure of the rotary base plate 80 prevents the rotary base plate 80 from being deformed.

In the perpendicularity adjusting 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 a base plate. Stand 2
Although it is screwed to the front side wall 200a of 00, three circular pedestals 203 are welded to the front side wall 200a, and the left side plate 21 is welded to the left and right ends of FIG.
The left main shaft 215 and the right main shaft 217 are attached to the 3 and right side plates 216 so as to be coaxially arranged. Left side plate 21 above
Two shafts 214 are provided at positions symmetrical to the left main shaft 215 in 3 such that the shafts are parallel to the left main shaft 215 and the axes are arranged on the same plane. A left support frame 230 and a right support frame 231 provided as members immovable with respect to the original exposure line 13 support the base 200 so as to be rotatable around a left main shaft 215 and a right main shaft 217. The support plate 218 and the right support plate 225 are welded to each other.

A recess 218a is formed in the center of the left support plate 218, and a bearing 218b having an arcuate cross section is recessed in the center of the bottom 218f of the recess 218a. The left main shaft 215 is fitted in the bearing portion 218b. A square bar 219 for positioning the left main shaft 215 is fixed to the bottom surface 218f of the recess 218a by two setscrews 220. On the other hand, a groove 215a is formed in an annular shape on the left main shaft 215, and the left main shaft 215 is fitted in the annular groove 215a so that the left main shaft 215 moves in the left-right main shaft direction, that is, the main scanning direction (X
The position is regulated in the immobile state in the axial direction). In addition, a set screw 221 screwed to the square bar 219.
The tip end of is pressed against the groove bottom 215b of the groove 215a.

Further, at the upper end portion and the lower end portion of the left support plate 218, grooves 218c and 218 for accommodating the shaft 214 in a loosely fitted state are provided.
d is recessed, and adjusting screws 222 and 223 are respectively screwed to the upper end portion and the lower end portion of the left support plate 218 so as to press the shaft 214. Then, by rotating the adjusting screws 222 and 223, the left side plate 213 and the right side plate 216 are moved to the left spindle 2
15, The right main shaft 217 is adapted to be rotated about both support shafts.

A bearing portion 225a having an arcuate cross section is recessed in the central portion of the right support plate 225, and a right main shaft 217 is fitted in the bearing portion 225a. On the surface of the right support plate 225, a square rod 226 for positioning the right main shaft 217 is provided with two setscrews 227.
The tip end of the push screw 228 screwed to the square rod 226 is pressed against the surface of the right main shaft 217.

In FIG. 15, the optical axis of the imaging lens 5 is set parallel to a straight line connecting the axis of the shaft 214 and the axis of the left main shaft 215, and passes through the left main shaft 215 and the right main shaft 217. The optical center of the imaging lens 5 is arranged in a plane extending in the sub-scanning direction, and the optical axis position of the imaging lens 5 is arranged in the vicinity of both left and right main axis lines. In such a configuration, the adjusting screws 222, 22
If 3 is rotated, the optical axis of the imaging lens 5 is rotated integrally with the base 200, and the tilt in the sub scanning direction (Y axis direction) is finely adjusted. By this, the perpendicularity of the optical axis of the imaging lens 5 and the original exposure surface in the sub-scanning direction is finely adjusted. In such an adjusting operation, the imaging lens 5 does not shift in the main scanning direction (X-axis direction) or 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 screws 221, 228 and the adjusting screws 222, 223 are set.
The base 200 is fixed in position, and thus the position of the imaging lens 5 is fixed.

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

In FIGS. 1, 2, 3, 4, and 14, as described above, the left support frame 230 and the right support frame 230, which are provided as members immovable with respect to the exposure line 13 of the original image, are provided. With respect to the frame 231, the base 200 is rotatably supported by a left main shaft 215 and a right main shaft 217 that are parallel to the exposure line 13 and have a coaxial center. The base 200 has an upper side wall 200b and a lower side wall. Fitting holes 201 and 202 are formed in the 200c so as to face each other. The mating holes 201 and 202 have spindles that are perpendicular to both the left spindle 215 and the right spindle 217.
113 is inserted. On the other hand, on the upper side wall 100b and the lower side wall 100c of the base plate 100, elongated holes 111, 112 extending in the sub-scanning direction are formed at positions corresponding to the fitting holes 201, 202, respectively. The upper and lower ends of the support shaft 113 are fitted together. Also the above spindle 1
Retaining rings 114 are respectively engaged with the upper and lower sides of the upper side wall 100b and the lower side wall 100c of the base plate 100 of 13 so that the support shaft 113 together with the base plate 100 causes the support shaft 113 to move in the optical axis direction of the imaging lens 5. It will be slidably supported by. At this time, the base plate 100 is movable in the sub-scanning direction (Y-axis direction),
In addition, it is immovable in the main scanning direction (X-axis direction).

Of the three circular pedestals 203 welded to the front side wall 200a of the base 200, the two circular pedestals 203 are the same as the support shaft 113.
Are arranged on a line parallel to the axis line of the above, separated by a predetermined distance, and the remaining one circular pedestal 203 is arranged on a line parallel to the axis lines of the left main shaft 215 and the 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
A female screw portion 203b for screwing a screw 104 described later is formed on each of them. On the other hand, on the front wall 100a of the base plate 100, three vertically elongated long holes 103 are formed at positions corresponding to the three circular pedestals 203, and the screws 104 are inserted in the respective long holes 103. Penetrates. A compression spring 106 is attached to the outside of the screw 104, and a pipe 105 is attached to the outside of the compression spring 106. One end of the compression spring 106 is pressed against the screw head of the screw 104 via a washer 108, and the other end of the compression spring 106 is a washer 107.
It is pressed against the base plate 100 via. This allows the base plate 100
Is pressed against the circular pedestal 203 side, and the base plate 100
Is slidable in the direction of the lens optical axis along the support shaft 113 while being pressed against the circular pedestal 203 side by the urging force of the compression springs 106 at three positions. At this time, the base plate 100 is kept stationary in the sub-scanning direction.

Further, a square bar 109 is screwed and fixed near the spindle 113 at the right end of the upper side wall 100b of the base plate 100.
The adjusting screw 110 is screwed onto the 09 so as to pass therethrough. The spherical tip portion 110a of the adjusting screw 110 passes through a large-diameter hole (not shown) formed in the upper side wall 100a of the base plate 100 and contacts the upper side wall 200b of the base 200.

As described above, the optical axis direction moving mechanism that slides the base plate 100 with respect to the base 200 in the Z axis direction, that is, the optical axis direction of the imaging lens 5 includes the support shaft 113, the adjusting screw 110, and the corner. Stick 109,
From a pair of retaining rings 114, fitting holes 201, 202, screws 104 on which elongated holes 111, 112 and compression springs 106 are wound, elongated holes 103 formed on the base plate 100, a circular pedestal 203 welded to the base 200, etc. Mainly composed.

In the present embodiment, the base plate 100 and the rotary base plate 80 mounted on the base plate 100, the lens unit 300 mounted on the rotary base plate 80, the CCD unit 20, the CCD base plate unit 30, the support shaft. The force of pressing the base plate 100 downward along the support shaft 113 by its own weight such as 64 causes the three compression springs 106 to move.
The front wall 100a of the base plate 100 and the front surface of the circular base 203 by pressing
Since it is configured to have a frictional resistance larger than that of 203a, a spring for pressing the base plate 100 downward is not used. However, if necessary, for example, a compression spring may be arranged so as to be fitted into the support shaft 113 between the lower side wall 100c of the base plate 100 and the lower side wall 200c of the base 200.

In such a configuration, by rotating the adjusting screw 110, the base plate 100 is finely adjusted and moved along the support shaft 113 while being in contact with the circular base 203. Therefore, the lens unit 300 and the CCD unit 20 can be finely adjusted and moved in the direction of the lens optical axis without displacement of each other due to the movement of the adjusting screw 110. Then, by this, the distance between the exposure line 13 and the CCD 2, that is, the conjugate length at a predetermined projection magnification (L in FIG. 2).
The fine adjustment of is made easy and accurate. Moreover, during such adjustment, the imaging lens 5
And CCD2 are the main scanning direction (X axis direction), the sub scanning direction (Y axis direction), the rotation direction around the lens optical axis (γ direction),
No deviation occurs in the inclination direction (α direction) in the main scanning direction and the inclination direction (β direction) in the sub scanning direction.

 Next, the light-shielding and dust-proof seal structure of the CCD2 will be described.

In FIGS. 3 and 5, an upper plate 311 that is adhesively fixed to the seal body 310 is fitted to the lower portion 301d of the lens holder 301 of the lens unit 300. 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 attached to the lower plate 312, and this lower plate 312 has
A notch 312a that engages with two countersunk screw pins 32 that screw the CCD unit 20 to the channel 31 is formed. The seal body 310 is mounted and positioned so as to shield the peripheral region outside the image forming optical path by the image forming lens 5 between the lens holder 301 and the metal plate 21 that holds the CCD 2 adhered.

The seal body 310 is formed by forming a soft foamed resin having fine eyes and light-shielding properties and air permeability into a rectangular tube shape, and its resilience causes the upper plate 311 against the lens holder 301 and the metal plate 21. And is abutted against the elastic force through the lower plate 312. No gap is formed between the upper plate 311 and the lens holder 301 and between the lower plate 312 and the metal plate 21. Such a seal body 310 blocks external light that deteriorates the image reading signal of the CCD 2, and
This will prevent dust and other dust from adhering to the CCD2.

Further, the seal body 310 is formed of a material and a shape dimension that does not impair the air permeability, which impedes the image reading function of the CCD2.
The drop is sufficiently prevented. Further, the hardness and size of the seal body 310 are such that the lens holder 301 or the metal plate 21 is not deformed or displaced from each other due to the elastic force of the seal body 310, and the lens holder 301 and the metal plate are not displaced. It is set so that it is possible to leave from between 21 and 21. Therefore, the upper plate 311 and the lower plate 312
The seal body 310 in which is adhered to the upper and lower sides is easily removable between the lens holder 301 and the metal plate 21, and is surely secured by the positioning means formed on the upper plate 311 and the lower plate 312. The metal plate 21 is positioned, and the mounting position does not shift when the position of the metal plate 21 is adjusted with respect to the lens holder 301, and the flexibility of the seal body 310 does not apply an unreasonable force to the lens holder 301 and the metal plate 21. It is like this.

In the cooling device shown in FIG. 5 (a), the air blown by the blower 206 has the dust-proof filter 208 attached to the duct 207 to remove dust, dust, and the like. It flows into the base 200, and from the square hole 205 of the base 200 to the square hole 100g of the base plate 100 and the square hole of the rotating base plate 80.
It is adapted to be sprayed toward the seal body 310, the lower part of the CCD 2 and the CCD control plate 22 through 80e. The blowing action of the blower 206 can also be controlled based on the temperature detection signal of the CCD 2 emitted from the thermistor 25 that is in contact with and bonded to the back surface of the CCD 2.

With such a cooling device of the CCD unit 20, the CCD2
CCD control board 2 soldered to itself or to the CCD 2
Expansion and deformation of the CCD 2 due to heat generation from 2 are prevented, which prevents the occurrence of abnormal image reading and also prevents malfunction of the electronic components on the CCD control plate 22 due to heat generation.

The CCD2 installed in the document reader is a cover glass
The surface of 2b is designed to prevent dirt and dust from adhering to it, but during long-term use, dirt and dust that may interfere with normal reading may adhere to it. Therefore, it is desirable to perform cleaning as necessary. It is also desirable that the CCD 2 be configured so that it can be easily replaced if the CCD 2 fails or its performance is degraded for some reason.

Therefore, in the present embodiment, the mounting member of the CCD 2 is rotatable in the sub-scanning direction, and the CCD 2 is formed integrally with the metal plate 21 that is the holding member of the CCD unit 20 to form the imaging optical path. A structure for retracting to the outside is adopted, which facilitates attachment / detachment to / from the mounting member. If you want to clean CCD2 without replacing it,
The unit 20 has a structure in which the front surface is obliquely exposed, and the cleaning operation is extremely easy. Moreover, the position of the CCD2 mounting member is configured to be accurately restored to the original position by the biasing of the adjusting screw and the spring even when the CCD unit 20 is replaced during cleaning, and the dimensions of the CCD unit 20 are also included. It is configured so that fine adjustment due to the above variations can be made extremely easily.

That is, as shown in FIG. 3, FIG. 4 and FIG. 6, the screw 6 screwed to the right side wall 80a of the rotating base plate 80.
When the tip portion of 8 is retracted to a position where it is separated from the long hole 62e provided in the upper arm portion 62d of the right lever 62, the right lever 62 is moved around the support shaft 64 by the urging force of the tension spring 61a. 6 As it is rotated counterclockwise in FIG. 6, the bent portion of the lower arm portion 62f of the right lever 62 is the right side wall 50d of the movable base plate 50.
Is contacted with the lower edge of the. As a result, the relative position between the movable base plate 50 and the right lever 62 around the support shaft 64 becomes stable. Similarly, the screw 69 screwed to the left side wall 80b is disengaged from the long hole 63e of the upper arm portion 63d of the left lever 63, so that the bent portion of the lower arm portion 63f of the left lever 63 is moved to the movable base plate 50.
Since the movable base plate 50 and the left lever 63 are brought into contact with the lower edge portion of the left side wall 50e, the relative positions of the movable base plate 50 and the left lever 63 around the support shaft 64 are in a stable state.

In this state, as shown in Fig. 6, CC
The movable base plate 50 on which the D unit 20 is mounted is rotatable together with the right lever 62 and the left lever 63 to the outside of the projection optical path of the imaging lens 5, but the rotation range is the right boss. Screws 73 and 74 threaded onto 81 and left boss 82, respectively
On the other hand, one end of each of the arc hole 62h of the right lever 62 and the arc hole 63h of the left lever 63 is regulated by being brought into contact with each other. In this state, the CCD unit 20 is exposed to the front surface of the apparatus, and cleaning of the CCD 2 and replacement and attachment / detachment of the CCD unit 20 are extremely easy. In this state, the movable base plate 5 with the CCD unit 20 attached
The position and size of the circular arc hole 62g are set so that the circular arc hole 62g of the right lever 62 does not come into contact with the adjusting screw 83 that positions 0 in the main scanning direction in cooperation with the compression spring 65. As a result, the adjusting screw 83 is prevented from being subjected to an unreasonable force so as to be displaced or deformed. At this time, the holding member (channel 31 in FIG. 3) of the CCD unit 20, which is held so that its position can be adjusted with respect to the movable base plate 50, is maintained in a completely unchanged state with respect to the movable base plate 50.

When necessary work such as cleaning and replacement of the CCD 2 and the CCD unit 20 is completed, the movable base plate 50 is pivotally returned to its original position. That is, if the right lever 62 and the left lever 63 are locked at predetermined positions by screws 68 and 69, respectively, the movable base plate 50 is rotated around the support shaft 64 by the urging force of the tension springs 61a and 61b. At this time, the tip ends of the adjusting screws 56, 58 are brought into contact with the front wall 80c of the rotating base plate 80, so that the movable base plate 50 is returned to the original position in a state of being accurately positioned. Has become. At this time, the right side wall 50d of the movable base plate 50 is also brought into contact with the adjusting screw 83 at the original position, and the position in the main scanning direction is also accurately returned to the original position.

In the image reading apparatus according to the embodiment of the present invention, a position adjusting mechanism using a step of a screw is adopted for adjusting the position of the CCD with respect to the image forming lens, adjusting the position of the image forming lens 5 with respect to the original image exposure surface, and the CCD 2. There is. That is, in the present embodiment, a means for pressing the male screw and the female screw in the radial direction is used in order to prevent a problem of fine adjustment due to play in the axial direction and the radial direction of the screw.

As shown in FIGS. 17 and 18, the square bar 38 and the movable base plate 50 are biased by a tension spring or gravity in a direction in which they approach each other, and An adjusting screw 39 is screwed into the formed female screw 38a, and a hemispherical tip portion 39a of the adjusting screw 39 is in contact with the upper surface 50i of the movable base plate 50. And square bar 38
The movable base plate 50 and the movable base plate 50 are positioned relative to each other by the cooperation of a tension spring or gravity. Further, a female screw 73 is formed in the direction orthogonal to the screw axis of the female screw 38a formed on the square rod 38, and this female screw 73 is formed.
A cylindrical damper 71 made of nylon having a diameter equal to or slightly smaller than the root diameter of 73 and a length substantially equal to the root diameter of the female screw 73 is fitted into the female screw 73. Further, in the female screw 73, the set screw 72 is
Is screwed onto the flat end 72a of the set screw 72.
Is configured to press the brake shoe 71.

When the flat tip portion 72a of the set screw 72 is brought into contact with the brake shoe 71, the set screw 72 is further strongly screwed in,
The nylon brake element 71 is pressed by the adjusting screw 39 while being compressed and deformed, and the brake element 71 has a tip portion 71a.
Goes into the threads and valleys of the adjusting screw 39, and the peripheral surface 71b of the brake element 71, which contacts the female threads 73, also plastically deforms into the threads and the valleys of the female threads 73. It will be. In this state, the male screw of the adjusting screw 39 is pressed in the radial direction with respect to the female screw 38a, the axial center of the adjusting screw 39 is kept slightly displaced from the axial center of the female screw 38a, and the adjusting screw 39 itself. Is rotated without shifting the axial center position. Therefore, the tip 39a of the adjusting screw 39 is not moved in the radial direction of the screw. Adjustment screw 39 having a male screw that meshes with the female screw 38a
When the adjustment screw 39 is rotated when rotating the
And the relative position of the movable base plate 50 will be adjusted,
At that time, due to the play in the engagement between the adjusting screw 39 and the female screw 38a, the adjusting screw 3 with respect to the upper surface 50i of the movable base plate 50 is
The abutting position of the tip portion 39a of 9 is designed not to be displaced.

Further, when the nylon brake shoe 71 is plastically deformed as described above, elastic stress is generated in the brake shoe 71 itself.
And the set screw 72 is prevented from being loosened carelessly. 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 retracts, and can be adjusted according to need.

In such a structure, the set screw 72 is further screwed in after the relative position of the movable base plate 50 and the square rod 38 is adjusted by the forward / backward movement of the adjusting screw 39, whereby the brake shoe 71 is further pressed and deformed. The adjusting screw 39 is fixedly locked to the female screw 38a. In this case, the adjusting screw 39 is not displaced with respect to the female screw 38a by screwing the set screw 72. Therefore, no other fastening means for locking the adjusting screw 39 to the female screw 38a is required.

If for some reason the adjusting screw 39 is rotated and it becomes necessary to readjust the mutual position of the movable base plate 50 and the square rod 38, loosen the set screw 72 slightly and release the brake element.
The pressing force of 71 on the adjusting screw 39 is reduced. By doing so, the adjusting screw 39 is rotated by the required pressing force with its axial center position maintained at a predetermined position, and the screw part of the adjusting screw 39 is not damaged. And no indentation,
Therefore, smooth rotation of the adjusting screw 39 will not be hindered.

Such an adjusting screw 39, a square rod 38, and an upper surface 50 of the movable base plate 50.
The position adjusting device constituted by i, the brake shoe 71 and the set screw 72 is the other position adjusting device, that is, the adjusting screws 53, 5
The same is applied to the position adjusting device using the 6,58,102,110,83.

As described above, according to the present invention, when the position of the photoelectric conversion element is slidably adjusted in the main scanning direction and the position of the photoelectric conversion element is rotationally adjusted in the sub scanning direction, the main scanning of the photoelectric conversion element is performed. About the direction
It is possible to prevent the deviation of the magnification and the defocusing of a single focal point from occurring without causing the deviation of the squareness of the photoelectric conversion element with respect to the optical axis of the imaging lens.

[Brief description of drawings]

FIG. 1 is an external perspective view showing an essential part of an optical system of an apparatus according to an embodiment of the present invention, and FIG. 2 is a set of imaging lenses and a CC.
An external perspective view showing the positional relationship with D, Fig. 3 shows a set of C
FIG. 4 is a front explanatory view showing the CD reading unit, and FIGS. 4 and 5 (a) are side views when the CCD reading unit shown in FIG. 3 is viewed from the arrow R direction and the arrow L direction, respectively. A sectional view, FIG. 5 (b) is a front explanatory view showing the shape of the hole provided in the base plate, and FIG. 6 is a side partial sectional view showing a state in which the CCD base plate unit is opened. Fig. 7 is an explanatory plan view showing the positioning and fixing structure of the CCD.
8 is a sectional explanatory view taken along the line AA 'in FIG. 7, FIG. 9 is a plan explanatory view showing another embodiment of the positioning and fixing structure of the CCD, and FIG. 10 is a sectional view in FIG. FIG. 11 is a sectional explanatory view taken along the line BB ', FIG. 11 is a sectional explanatory view equivalent to FIG. 10 showing another embodiment of the CCD connecting structure, and FIG. 12 is an exploded perspective view showing the fine adjustment structure of the CCD. 13 and 14 are longitudinal cross-sectional explanatory views showing the focus adjustment mounting structure of the imaging lens, and FIG.
FIG. 15 is a front explanatory view showing a state in which the reading unit shown in the figure is removed from the base, and FIG. 15 is AA ′ in FIG.
Explanatory drawing in section taken along the line, FIG. 16 shows B- in FIG.
FIGS. 17 and 18 are sectional explanatory views taken along the line B ', and FIG. 17 and FIG. 18 are sectional explanatory views showing the locking structure of the adjusting screw. CCD as photoelectric conversion element, 4,5,6 ... Imaging lens, 12 ... Original, 13 ... Exposure line, 15 ... Read unit, 20 ... CCD unit, 30 ... … CCD bedplate unit, 31
...... Channel as second holding member, 33 ...... Horizontal axis as second supporting shaft, 35 ・ ・ ・ Vertical axis as first supporting shaft, 50
...... Movable base plate as first holding member, 64 ...... Third support shaft, 80 ...... Rotation base plate, 94 ...... Conical shaft as axis in sub-scanning direction and orthogonal to optical axis, 100 ... Base plate, 110 ... Adjusting screw that constitutes the optical axis direction moving mechanism, 113 ... Support shaft that constitutes the optical axis direction moving mechanism, 200 ... Base, 215 ... Left spindle,
217 …… Right spindle, 230 Left support frame, 231 …… Right support frame, 300…
... Lens unit, 306 ... Focus adjusting shaft that constitutes the lens barrel moving mechanism, 306a ... Eccentric cam that constitutes the lens barrel moving mechanism,
321 ...... The lens barrel forming the lens barrel moving mechanism, 322 ...... The groove forming the lens barrel moving mechanism.

Claims (1)

(57) [Claims] 1. An original image is projected on a photoelectric conversion element by an imaging lens, and the original image and the photoelectric conversion element are relatively moved in the sub-scanning direction to photoelectrically read the original image. In a position adjusting mechanism of an image reading apparatus, a lens unit having a lens barrel moving mechanism that moves the imaging lens in the optical axis direction thereof, a first support shaft arranged in parallel with the optical axis, and a sub-scanning direction. A second support shaft extending in the direction, orthogonal to the first support shaft, and rotatable about an axis orthogonal to the first support shaft and around the first support shaft, A first end having a base end portion provided on the first support shaft, a free end portion extending in the main scanning direction orthogonal to the sub-scanning direction, and having a surface substantially orthogonal to the optical axis is provided. The holding member and the base end of the holding member sandwich the crossing portion of the first support shaft and the second support shaft, and then the second support shaft. A second holding member for holding the photoelectric conversion element, the free end portion of which is extended to face the first holding member, and which extends in the main scanning direction and has an axis in the main scanning direction. A third support shaft that rotatably supports the second holding member via the first holding member and is slidable in the axial direction of the main scanning direction; and the lens unit, The sub-scanning direction, which is rotatably supported about an axis orthogonal to the optical axis and which supports the third supporting shaft, and the above-mentioned rotary base plate are provided in the sub-scanning direction. A base plate that is rotatably supported about an axis orthogonal to the optical axis, a base plate that holds the base plate, and is arranged immovably in the main scanning direction with respect to the reading position of the original image. An optical axis direction moving mechanism for moving the base plate in the optical axis direction with respect to the base plate. Image reading device position adjustment mechanism.