JPH0748793B2 - 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. In general, the maximum size of the scanned document is limited to about A3 size, but in certain fields such as industrial drawings, the size of the target document is 841 mm wide (JIS A0 size) or 36 〃 (941 mm).
Some are larger (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 The scanning direction is positioned so as to be orthogonal to the optical axis, and the optical axis of the imaging lens is positioned so as to be orthogonal to the document image exposure surface, so that the document image and the photoelectric conversion element are relatively moved. However, it is impossible to photoelectrically read a document image. 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.

On the other hand, the lens balls and lens barrels that make up the imaging lens are also to be processed and assembled with high precision correspondingly, but the imaging lens is accurately positioned at the in-focus position, and It must be adjusted so as not to cause tilting or eccentricity of the optical axis when it is moved in the axial direction, and consideration must be given so as not to cause positional displacement when fixing after movement.

Conventionally, various support structures for CCDs and imaging lenses have been proposed in JP-A-51-51217 and the like, but in all of them, misalignment occurs during focusing of the imaging lens or fixation after positioning. It tends to occur, and it is no longer possible to favorably position the imaging lens.

The present invention, when positioning the imaging lens, adjusts the focus with high accuracy without causing radial deviation of the imaging lens, tilting or rotation of the optical axis, and supports the imaging lens without impairing the focused state. An object of the present invention is to provide a position adjusting mechanism of an image reading apparatus that can be easily and surely locked to a member.

[Means for Solving the Problem] In order to achieve the above object, the invention according to claim 1 projects an original image on a photoelectric conversion element by an imaging lens, and sub-images the original image and the photoelectric conversion element. In a position adjusting mechanism of an image reading device that photoelectrically reads the original image by moving the lens barrel in the scanning direction, a lens barrel support holder for housing the lens barrel of the imaging lens, and an axis of the lens barrel. A focus adjustment shaft held by the lens barrel support holder so as to be movable in the axial direction and rotatable about the axis, and the lens barrel is rotated based on the rotation operation of the focus adjustment shaft about the axis. A focus adjusting device having an eccentric cam mechanism that moves in the axial direction and a pressing unit that presses the focus adjusting shaft in the axial direction toward the imaging lens side and in a direction orthogonal to the axis is characterized. I am trying.

According to a second aspect of the invention, in the position adjusting mechanism of the image reading apparatus according to the first aspect, the focus adjusting device presses the lens barrel in the optical axis direction to move the lens barrel in the optical axis rotation direction. It is characterized by having a rotation locking means for regulating.

According to a third aspect of the invention, in the position adjusting mechanism of the image reading apparatus according to the first or second aspect, the pressing means applies a pressing force in one direction to an axial component force toward the imaging lens side and the axis. It is characterized in that it is provided with a means for decomposing into a component force in the direction orthogonal to the axis in the direction orthogonal to.

According to a fourth aspect of the invention, in the position adjusting mechanism of the image reading apparatus according to the second or third aspect, the pressing direction of the rotation locking means and the direction of the component force in the axial orthogonal direction by the pressing means are the same. It is characterized by the direction.

[Operation] In the means having such a configuration, the lens barrel of the imaging lens is moved and adjusted in the optical axis direction through the eccentric cam mechanism by the rotational movement of the focus adjustment shaft, and the pressing means and rotation are performed. The locking means keeps the focus adjustment axis and the imaging lens in a fixed position.

[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 (CCD)
It is designed so that it is projected on 1, 2, and 3 pixel columns.

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 (picxel) of 7 μm x 7 μm
Consisting of a linear sensor with a pixel row length of 35 mm
Is set to. Therefore, the length of the region l ₂ is 31
It will be 7.5mm. Here, if the width of the original 12 on the exposure line 13, that is, the maximum reading width l is 914.4 mm,
The overlap amount l ₁₂ −l ₂₃ on the exposure line 13 is 12.7 mm.
b, which is 1.4 mm (200 pixels) on the pixel row 2a of the CCD2.

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, as shown in FIG. 2, the position of CCD2 is X in the main scanning direction.
The fine adjustment is possible in parallel in the axial 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, and the X-axis direction, the Y-axis direction, and the Z Rotational fine adjustment movement is possible around each axis in the axial direction.

As shown in FIG. 3, FIG. 4 and FIG. 5, the reading unit 15 can be finely adjusted in parallel with the base 200 in the optical axis direction (Z-axis direction) of the imaging lens 5. Around a base plate 100 having a U-shaped cross section attached to the base plate 100, and a conical shaft 94 having an optical axis at the optical center of the imaging lens 5 with respect to the base plate 100 and having an axis in the sub-scanning direction. A rotary base plate 80 that is finely adjustable in rotation, and a shading correction plate 97 that is screwed to an upper side wall 80d of the rotary base plate 80 so as to be movable in a direction orthogonal to the optical axis. The optical axis of the imaging lens 5 is located approximately in the center of the front side wall 80c of the rotating base plate 80, and is a conical axis that is orthogonal 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
And a CCD base plate unit 30 mounted for fine adjustment of rotation and fine adjustment of sliding in the axial direction with respect to the support shaft 64. There is.

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

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. The rotation plane is set to a plane including the optical center of the imaging lens 5 and 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 21g above
3 support pieces are formed so as to project inward, and the main scanning direction reference edge 21a and the sub-scanning direction reference edge 21b, which are respectively formed at the tips of the respective support pieces, An end face in the main scanning direction and an end face in the sub scanning direction of the ceramic case of the CCD 2 are respectively brought into contact with and held by 21c. 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, whereby the pixel row 2a of the CCD 2 is positioned. The positioning is performed with a predetermined accuracy. At this time, cover glass 2b of CCD2,
The upper surface of the metal plate 21 is in the same plane. In addition, the CCD2 ceramic case and the above positioning holes
The two-part epoxy resin is injected and cured in the gap between the CCD2 and the 21g to make the CCD 2 immobile.

The CCD control board PCB-122 including an amplifier circuit for amplifying the image reading signal from the CCD2 is soldered to and held by the 22 connection pins 2c of the CCD2. Two connectors 23 are soldered to the CCD control board PCB-122, and flat cables 24 each composed of a plurality of lead wires are detachably attached. A thermistor 25 for detecting the temperature of the CCD2 is mounted in the mounting hole 22a provided in the CCD control plate PCB-122, and is bonded and held by an epoxy resin in a state of being in contact with the ceramic case of the CCD2. It is like this.

Further, a connector 23 is soldered to the CCD control board PCB-122, and one end of a flat cable 24 is inserted into the connector 23. The other end of the flat cable 24 is inserted and connected to a connector 401 soldered to a CCD control board PCB-2400 (see FIGS. 3 and 5). CCD control board PCB-2400 above
Which constitutes a drive control circuit of CCD2,
It is larger than the CCD control board PCB-122 and has more control electronic components mounted on it, which causes more heat generation. Therefore, it is desirable that the CCD control plate PCB-2400 is installed as far away from the CCD 2 as possible. In this embodiment, the base plate is
The right support leg 100d and the left support leg 100e extending downward from 100 are locked by screws 404 so that the heat generation of the CCD control board PCB-2400 does not affect the CCD2. .

The CCD control board PCB-122 thus separated from each other.
If the flat cable 24 and the CCD control plate PCB-2400 are connected to each other, it is possible that electrical noise is picked up through the flat cable 24 and an accurate signal corresponding to the original image cannot be output. Therefore, in the present embodiment, as described above, the CCD control board PCB-122 directly connected to the CCD2 is provided with a read signal amplifying function,
This minimizes the effect of electrical noise. As a result, the flat cable 24 can be lengthened to some extent, which allows the CCD control board PCB-2400.
The positional restrictions of the CCD are alleviated, and even if the CCD2 is adjusted in a relatively large range, the CCD2 is not subjected to an excessive force, and the flat cable 24 and the connector 23,401
It is possible to eliminate continuous defects with.

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 board PCB-122. That is, the socket 26 is soldered to the CCD control board PCB-122 via the connection pin 26a, and the connection pin 2c of the CCD 2 is inserted into the socket 26. This way, the CCD2 connection pins
By inserting 2c into the socket 26, it is possible to easily and inexpensively replace the CCD 2 or the CCD control board PCB-122.

Next, the lens unit 300 is shown in FIG. 13, FIG. 5 and FIG.
It will be described with reference to the drawings. The lens holder 301 serving as a lens barrel support holder is formed of an aluminum casting having a substantially L-shaped cross section, and the rear portion 301b of the lens holder 301 is formed with three convex portions 301e, and at the same time, Moving base plate 80
Mounting hole 303 is formed. The projecting tip flat surface portion of the convex portion 301e and the holder lower surface portion 301d are cut so as to have a relationship orthogonal to each other.
With reference to 301e and 301d, a fitting hole 304 for housing the imaging lens 5 is formed so as to penetrate in the optical axis direction.
That is, the axis of the fitting hole 304 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 cylindrical female screw 9 is attached to the rear portion 301b of the lens holder 301.
A fitting hole 302 to be fitted to the outer peripheral portion of 5 is formed. The cylindrical female screw 95 rotates the conical shaft 94 on the front wall 80c of the rotating base plate 80.
It is to be locked to. At this time, the formation position of the fitting hole 302 is accurately set on the optical center of the imaging lens 5 in a direction orthogonal to the lens optical axis and orthogonal to the protruding tip flat surface portion of the convex portion 301e. There is. On the other hand, the support shaft 64 has a movable base plate 50 for holding the CCD base plate unit 30.
Is rotatably and slidably supported, but the fitting hole 302
The lens unit 300 is rotationally adjusted about the center of the holder so that the lower surface 301d of the holder 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 has become. As a result, the optical axis of the imaging lens 5 and the support shaft 64
The right-angle accuracy required between and is guaranteed.

Further, the tip end portion of a leaf spring 325 as a rotation locking means screwed to the front portion 301a of the lens holder 301 is in pressure contact with the upper edge portion of the image forming lens 5, whereby the image forming lens 5 is exposed to light. It is adapted to be pressed downward in the axial direction. On the front part 301a of the lens holder 301,
A fitting hole 305 is formed in a direction orthogonal to the lens optical axis, and a focus for finely moving the imaging lens 5 in the optical axis direction to focus and lock the fitting lens 305. The adjustment shaft 306 is rotatably fitted. 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 306a is formed at the rear end of the focus adjusting shaft 306.
The 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 to 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 to the pressing 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 pressing means includes the pressure rod 307 and the set screw 308.
Composed of. The eccentric cam mechanism is composed of the eccentric cam 306a and the groove 322 of the lens barrel 321.

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 leaf spring 325 prevents the imaging lens 5 from rotating around the optical axis and maintains the state in which the groove side surface 322b of the groove 322 is pressed against the cam surface of the eccentric cam 306a. . 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,
Further increasing the axial component force P ₁ and the axial orthogonal component component P ₂ by further screwing the set screw 308 allows the imaging lens 5 to be reliably locked to the lens holder 301 without displacement. The rotation of the focus adjustment shaft 306 is stopped.

Next, regarding the position adjusting mechanism of the CCD 2, FIG. 3, FIG.
A description will be given with reference to FIGS. 5, 12, 18, and 19.

First, the inclination of the CCD 2 in the X-axis direction which is the main scanning direction, that is, Y
In the rotation fine adjustment mechanism about the axis α and the rotation fine adjustment mechanism about the Z axis γ which is the optical axis direction of the imaging lens 5, the CCD having the metal plate 21 for holding the CCD 2 at the constant reference position as described above. The unit 20 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 board PCB-122 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 substantially cylindrical horizontal shaft 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 and tightened and fixed by a flat head screw 34. ing. Further, in the central portion of the horizontal shaft 33, two conical portions 33a are formed so as to face each other, and these both conical portions 33a are formed in the channel-shaped rectangular cutout portion 31c. It is housed in. 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 is erected in the Z-axis direction (optical axis direction), and is formed at the upper end portion of the vertical axis 35. The lower outer peripheral edge of the cylindrical portion 35a is in contact with the conical inclined side surfaces of the two conical portions 33a formed on the horizontal shaft 33. As a result, the entire channel 31 including the CCD unit 20 can be rotated about the horizontal axis 33 and the vertical axis 35.

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

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.
These stepped pins 36 are each screwed in the vicinity.
The upper ends of tension springs 37a and 37b are hooked on a and 36b, respectively. The lower ends of the tension springs 37a and 37b are provided on the front side wall 50g and the rear side wall of the movable base plate 50.
It is hung on stepped pins 54a and 54b, which are screwed to 50h, respectively. These tension springs 37a and 37b
Are obliquely extended to form an angle of about 45 ° with respect to the Z axis (optical axis), and the pulling force causes the channel 31 to move downward and rightward in FIG. 12 inside the vicinity of the square rod 38. A component force of pressing is generated. Then, the lower outer peripheral edge portion 35a of the cylindrical portion of the vertical axis 35 is formed into the conical shape of the two conical portions 33a formed on the horizontal axis 33 by the force component to the right of the tension 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 force 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 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, 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 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 of the stepped pins 36a and 36b is set to such an extent that it does not prevent the channel 31 from being rotated around the vertical axis 35.

Further, a spring hooking 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 40g is provided in a hole 31h provided in the spring hooking portion 31g.
One end of is hung. On the other hand, a square bar 51 is screwed and fixed to the side surface of the movable base plate 50, and the tension spring is attached to the stepped pin 52 erected on the square bar 51.
The other end of 40 is hung. 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 rotation adjustment in the α direction around the Y axis and Z-axis rotation γ that is the optical axis direction of the imaging lens 5
Rotational fine adjustment of direction is accurately performed. That is, first, by rotating the adjusting screw 39, the tension springs 37a, 37b
The channel 31 is rotated about the horizontal axis 33 in opposition to, and thereby 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. Further, since the horizontal axis 33 is provided at a position sufficiently separated from the CCD2, the CCD2 is hardly displaced in the X-axis direction which is the main scanning direction when the CCD2 is adjusted in the α inclination direction. .

On the other hand, by rotating the adjusting screw 53, the tension spring 40
The channel 31 is rotated about the vertical axis 35 in the γ direction about the Z axis to perform 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 has become so. 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 on the upper surface 50i of the movable base plate 50 while being in contact with the horizontal axis 33.
The cylindrical portion 33b of the movable base plate 50 is slid while being in contact with the upper surface 50a of the movable base plate 50, but the squareness of the upper surfaces 50i and 50a of the movable base plate 50 with respect to the vertical axis 35 has the required accuracy. Since it is maintained, the sliding movement causes the channel 31 to move to the horizontal axis 33.
There is almost no turning around and there is no problem 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.

A square bar 5 is provided on the rear side wall 50h of the movable base plate 50 in the Y-axis direction.
5, 57 are attached, and adjusting screws 56, 58 are screwed to these square bars 55, 57. Adjusting screw 56,58 above
The tip end portion of is formed in a spherical shape, and the spherical tip end portion is in contact with the front wall 80c of the rotation 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. It is slidably and rotatably fitted to a support shaft 64 that is hung between 82 and the shaft. 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. Holes formed in the tips of these L-shaped plates 59 and 60
One ends of tension springs 61a and 61b are attached to 59a and 60a. 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 the left lever 63, and these fitting holes 62a and 63a are attached to the support shaft 64. The right lever 62 and the left lever 63 are arranged outside the right side wall 50d and the left side wall 50e of the movable base plate 50, respectively, and are locked in the long holes 62e and 63e formed in the upper arm portions 62d and 63d of the movable base plate 50, respectively. The engagement of the screws 68 and 69 stops the rotation of the right lever 62 and the left lever 63 with respect to the support shaft 64, respectively. The locking screws 68 and 69 are respectively screwed so as to penetrate the right side wall 80a and the left side wall 80b of the rotary base plate 80 in the X-axis direction.

Also, holes 62c and 63c are formed in the middle arm parts 62b and 63b extending in the direction orthogonal to the upper arm parts 62d and 63d, that is, toward the front wall 80c of the rotating base plate 80, and these holes 62c and 63c are formed. Extension springs 61a and 61b previously described in 63c
The other end of 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. The tension spring 61a is extended so that its urging force causes a component of force in the tangential direction and the normal direction about the support shaft 64, whereby the movable base plate
The 50 is pressed and urged by the support shaft 64 to be held at 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 is formed on the right side wall 50d of the movable base plate 50. It is in contact with the lower edge. And for maintenance replacement, etc.
When the CCD unit 20 is rotated to the front side to the state shown in FIG. 6, the tension spring 61a in a predetermined deenergized state is held so as not to 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 penetrated through the 62g in a non-contact state, and a locking screw 73 is 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 formed through the center portions of the right boss 81 and the left boss 82, which are 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
It is 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, which satisfies the position adjustment accuracy of 55.1 μm of the pixel row 2a of the CCD 2 for adjusting the overlap amount 12.7 mm on the original exposure line 13 in 0.5 mm units. In order to do so, the adjustment screw 83 may be rotationally adjusted with an accuracy of about 40 °, and the adjustment operation can be performed extremely easily. In the adjusting operation of the CCD 2 in the main scanning direction (X axis direction) by the adjusting screw 83, the position of the CCD 2 is the sub scanning direction (Y axis direction), the main scanning inclination direction (α direction), the optical axis rotation direction (γ direction). Alternatively, there is no deviation in each Z-axis direction. This is configured such that the perpendicularity of the support shaft 64 to the optical axis of the imaging lens 5 can be adjusted with an accuracy of ± 1 ', and the parallelism of the support shaft 64 to the exposure line 13 of the original image is also ±. Being kept within 1'accuracy,
And the movable base plate 50 is pressed in the radial direction of the support shaft 64 by the urging force of the tension springs 61a, 61b, and at the same time, the adjusting screws 56, 58
This is because the position of the movable base plate 50 is maintained by the front wall 80c of the rotary base plate 80 via the. Also, 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 CCD2, the sub-scanning of the right boss 81 and the left boss 82 supporting the support shaft 64 is performed. Positioning accuracy in the direction (Y-axis direction) is normal processing accuracy (for example ± 0.
1 mm), the positional deviation in the sub-scanning direction (Y-axis direction) is about 2 μm with respect to the position adjustment amount 2 mm of the CCD 2 in the main scanning direction X, and there is no problem in adjustment.

Next, the image forming 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 is formed.
The perpendicularity adjusting mechanism of the optical axis will be described.

As shown in FIGS. 3, 4 and 5, the central portion of the front wall 80c of the rotating base plate 80 is the optical center of the imaging lens 5 and the light of the imaging lens 5 A hole 96 is formed so as to be orthogonal to the axis, and the conical shaft 94 is fitted and inserted into the hole 96, and the conical shaft 94 is tightened by a cylindrical female screw 95 with respect to the front wall 80c. It is fixed at a right angle. The rotating base plate 80 is arranged so as to face the front wall 100a of the base plate 100 having a U-shaped cross section, and is provided on the front wall 100a of the base plate 100. The large diameter side of the conical shaft 94 penetrates the arc hole 120a of the dowel hole 120 (see FIG. 5 (b)) to penetrate the base plate.
It is projected inside 100. At this time, the arcuate hole portion 120a of the engaging hole 120 is formed to be smaller than the maximum diameter and larger than the minimum diameter of the conical portion of the conical shaft 94, and the conical inclined surface 94a of the conical shaft 94 is engaged. It is engaged with the arcuate hole portion 120a of the dowel hole 120. Thereby, the front wall 100a of the base plate 100
On the other hand, the rotation base plate 80 is configured to be rotatable around the conical shaft 94.

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.
The conical inclined surface 94a of 94 engages with the arcuate hole portion 120a of the engaging hole 120, so that the conical shaft 94 receives a component force to the left in FIG. It is pressed against the board 100 side. 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 °. Further, the rotating base plate 80 is brought into contact with the outer surface of the front wall 80c of the rotating base plate 80 to support the rotating base plate 80 at three points, whereby the rotating base plate 80 can be stably rotated. Further, on the front wall 80c of the rotary base plate 8, three elongated holes 84, 85, 86 are arranged on the circumference centered on the conical shaft 94 at equal intervals of 120 °.
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 to fix the rotating base plate. ing.

Therefore, if the adjusting screw 102 is rotated while the set screws 87, 88, 89 are loosened, the rotation base plate 8 is rotated about the conical shaft 94.
0 is rotated and the original exposure line 13 on the optical axis of the imaging lens 5 is rotated.
The squareness in the main scanning direction with respect to 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. No deviation occurs in any of the (α direction), the direction around the optical axis (γ direction), or the Z axis direction. Further, the three-point support structure of the rotary base plate 80 prevents the rotary base plate 80 from being deformed.

In the mechanism for adjusting the perpendicularity of the optical axis of the imaging lens 5 to the original image exposure surface in the sub-scanning direction, as shown in FIGS. 14, 15 and 16, the base plate 100 is a base plate. Stand 200
The front side wall 200a is screwed to the front side wall 200a, and three circular pedestals 203 are welded to the front side wall 200a.
The left main shaft 215 and the right main shaft 217 are coaxially arranged on the left side plate 213 and the right side plate 216, which are welded to the left and right ends of FIG. 4, respectively. Left side plate 213
At two symmetrical positions of the left main shaft 215, two shafts 214 are provided so as to be in parallel with the left main shaft 215 and the axes thereof 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 portion 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. The bearing portion 225a has a right main shaft.
217 is fitted. Further, a square rod 226 for positioning the right main shaft 217 is fixed to the surface portion of the right support plate 225 by two set screws 226, and a tip portion of the set 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, 223
If the optical axis of the imaging lens 5 is to be rotated,
It is rotated integrally with 200, and the inclination 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. These mating holes 201 and 202 should have a spindle that is perpendicular to both ends of the left spindle 231 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 arranged on a line parallel to the axis of the support shaft 113 with a predetermined separation. And the remaining one circular pedestal 203 is
It is arranged on a line parallel to the axes of 15 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 female thread portions 203b to which the screws 104 described later are screwed are formed respectively. 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 pass through the respective long holes 103. A compression spring on the outside of the screw 104
A tube 105 is mounted on the outer side of the compression spring 106 while the 106 is mounted. One end of the compression spring 106 is pressed against the screw head portion of the screw 104 via a washer 108, and the other end of the compression spring 106 is pressed against the base plate 100 via a washer 107. This causes the base plate 100 to be pressed toward the circular pedestal 203 side, and the base plate 100 is
It 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 locations. At this time, the base plate 100 is kept stationary in the sub-scanning direction.

Further, at the right end of the upper side wall 100b of the base plate 100, a square bar 109 is screwed and fixed near the support shaft 113.
The adjusting screw 110 is screwed so as to penetrate 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.

In the present embodiment, the base plate 100, the rotary base plate 80 mounted on the base plate 100, and the lens unit 300, the CCD unit 20, the CCD base plate unit 3 mounted on the rotary base plate 80.
The force of pressing and sliding the base plate 100 downward along the support shaft 113 due to its own weight such as 0 and the support shaft 64 causes the front wall 100a of the base plate 100 and the circular base 203 to be pressed by the three compression springs 106. Front 20
Since it is configured to be larger than the frictional resistance force with respect to 3a, a spring for pressing the base plate 100 downward is not used. However, if necessary, a compression spring may be arranged so as to be inserted into the support 113 between the lower side wall 100c of the base plate 100 and the lower side wall 200c of the base 200, for example.

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, by moving the adjusting screw 110 back and forth, the lens unit 3
The 00 and the CCD unit 20 are finely adjusted and moved in the direction of the lens optical axis without any positional deviation therebetween. 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 dustproof sealing 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 adhered 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 elastically abutted via the lower plate 312. Between the upper plate 311 and the lens holder 301, and the lower plate
No gap is created between the 312 and the metal plate 21. Such a seal body 310 blocks external light that deteriorates the image reading signal of the CCD2, and at the same time, CC
This will prevent dust and dirt from adhering to D2.

Further, the seal body 310 is formed of a material and a shape dimension that does not impair the air permeability, and is designed to sufficiently prevent the image reading function of the CCD 2 from being hindered or deteriorated. 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 seal body 310 in which the upper plate 311 and the lower plate 312 are vertically adhered is used as the lens holder 3
01 and the metal plate 21 are easily removable, and are reliably positioned by the positioning means formed on the upper plate 311 and the lower plate 312. At the time of position adjustment, the mounting position does not shift, and the flexibility of the seal body 310 prevents an unreasonable force from being applied to the lens holder 301 and the metal plate 21.

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 80 of the rotary base plate 80.
Pass through e, above seal 310, lower part of CCD2 and PCB-122
It is designed to be sprayed toward. This blower
The air blowing action of 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.

Such a cooling device of the CCD unit 20 prevents expansion and deformation of the CCD2 due to heat generation from the CCD2 itself or the PCB-122 soldered to the CCD2, thereby preventing the occurrence of abnormal image reading. Is also a PC
Malfunction due to heat generation of electronic components on B-122 is also prevented.

The CCD 2 mounted on the document reader is the cover glass 2b.
The surface of the device is protected from dust and dirt, but dust and dirt that may interfere with normal reading may be stuck during long-term use. It is advisable to perform cleaning if 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. Further, when the CCD 2 is simply cleaned without replacement, the CCD unit 20 is exposed to the front with a tilt, so that the cleaning operation can be performed very easily. Moreover, even when the CCD unit 20 is replaced during cleaning, the device of the CCD2 mounting member is configured to be accurately returned to its original position by the biasing of the adjusting screw and the spring, and the size of the CCD unit 20. It is configured so that fine adjustment due to the above variations can be made extremely easily.

That is, as shown in FIGS. 3, 4, and 6, the screw 68 screwed to the right side wall 80a of the rotary base plate 80.
When the tip portion of the right lever 62 is retracted to a position where it is disengaged from the elongated 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. As it is rotated counterclockwise in the figure, the bent portion of the lower arm portion 62f of the right lever 62 becomes 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, the CCD
The movable base plate 50 on which the 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 81. It is regulated by abutting one ends of the arc hole 62h of the right lever 62 and the arc hole 63h of the left lever 63, respectively, with respect to the screws 73 and 74 screwed to the left boss 82. In this state, the CCD unit 20 is exposed to the front surface of the apparatus, and the CCD 2 is cleaned and the CCD unit 2
Replacement and removal of 0 is extremely easy. In this state, the movable base plate 50 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 cooperates with the compression spring 65 to position in the main scanning direction. This prevents an unreasonable force from being applied to the adjusting screw 83, resulting in displacement of the adjusting screw 83 or deformation thereof. 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, screw the right lever 62 and the left lever 63
If the movable base plate 50 is locked at predetermined positions by 68 and 69, the movable base plate 50 is rotated around the support shaft 64 by the urging force of the tension springs 61a and 61b.
The movable base plate 50 is returned in a state of being accurately positioned to the original position by abutting the front end portions of the 56 and 58 against the front wall 80c of the rotary base plate 80. 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. The mutual positions of the square rod 38 and the movable base plate 50 are positioned by the cooperation of a tension spring or gravity. Further, a female screw 73 is formed in a direction orthogonal to the screw axis of the female screw 38a formed on the square rod 38, and this female screw 73
A nylon cylindrical brake shoe 71 having a diameter slightly smaller than the root diameter of the female thread 73 and a length substantially equal to the root diameter of the female thread 73 is fitted into the female thread 73. A set screw 72 is screwed into the female screw 73 from the rear of the brake element 71, and a flat tip portion 72a of the set screw 72 presses the brake element 71.

When the flat tip portion 72a of the set screw 72 is abutted on the brake shoe 71, the set screw 72 is further strongly screwed in. Pressed, the tip portion 71a of the brake element 71 bites into the threads and valleys of the adjusting screw 39,
The peripheral surface 71b of the brake shoe 71, which is in contact with the female screw 73, is also
Plastic deformation will occur as if it goes into the threads and valleys of. In this state, the male screw of the adjusting screw 39 is pressed against the female screw 38a in the radial direction,
The shaft center of the adjusting screw 39 is kept slightly displaced from the shaft center of the female screw 38a, and the shaft center position is rotated by the rotation of the adjusting screw 39 itself. Therefore, the adjusting screw 39
The tip portion 39a of the is not moved in the radial direction of the screw. The relative position between the square rod 38 and the movable base plate 50 is adjusted by the step of the adjusting screw 39 when the adjusting screw 39 having the male screw that meshes with the female screw 38a is rotated. The adjustment screw 39 with respect to the upper surface 50i of the movable base plate 50 is provided by the play in the engagement with the female screw 38a.
The contact position of the tip portion 39a of the is not displaced.

Further, when the nylon brake shoe 71 is plastically deformed as described above, elastic stress is generated in itself, so that the brake shoe 71 and the set screw 72 are prevented from being unintentionally loosened. 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 in a state in which its axial center position is maintained at a predetermined position by a required pressing force, and the screw portion of the adjusting screw 39 has some scratches and No indentation is produced, and thus smooth rotation of the adjusting screw 39 is not 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.

EFFECTS OF THE INVENTION As described above, according to the present invention, when focusing and positioning the imaging lens, the imaging lens and the imaging lens are positioned without tilting or rotating the optical axis thereof. Adjustment locking can be performed without moving the focus adjustment axis to be performed in the radial direction, and fine adjustment of focus of the imaging lens can be performed with high accuracy and easily.

[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 a hole provided in the base plate, and FIG. 6 is a side sectional view showing a state in which the CCD reading unit is opened. The figure 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. 1,2,3 …… Photoelectric conversion element (CCD), 4,5,6 …… Imaging lens, 12 …… Original, 13 …… Exposure line, 15 …… Reading unit, 20 …… CCD unit, 300… … Lens unit, 301
...... Lens holder as a lens barrel support holder, 306…
... Focus adjusting shaft, 306a ... Eccentric cam which constitutes eccentric cam mechanism, 307 ... Pressure rod which constitutes pressing means, 308 ... Set screw which constitutes pressing means, 321 ... Lens barrel, 322 ... Grooves that make up the eccentric cam mechanism, 325 ... Leaf springs as rotation locking means.

Claims (4)

[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 device, a lens barrel support holder for accommodating a lens barrel of the imaging lens and a lens barrel support holder are movable in an axial direction orthogonal to an axis of the lens barrel and rotatable about the axis. The focus adjustment shaft held by the lens barrel support holder, an eccentric cam mechanism for moving the lens barrel in the optical axis direction based on the rotational movement of the focus adjustment shaft around the axis, and the focus adjustment shaft are imaged. A position adjusting mechanism for an image reading apparatus, comprising: a focus adjusting device having an axial direction toward the lens side and a pressing means for pressing in a direction orthogonal to the axis. 2. A position adjusting mechanism for an image reading apparatus according to claim 1, wherein the focus adjusting device presses the lens barrel in an optical axis direction to regulate the lens barrel in a direction around the optical axis. A position adjusting mechanism for an image reading apparatus, which has a locking means. 3. A position adjusting mechanism for an image reading apparatus according to claim 1 or 2, wherein the pressing means applies a pressing force directed in one direction to an axial component force directed to the imaging lens side and the axis. A position adjusting mechanism for an image reading apparatus, characterized in that the position adjusting mechanism includes means for decomposing into a component force in a direction orthogonal to the direction of the axis. 4. The position adjusting mechanism of the image reading apparatus according to claim 2 or 3, wherein the pressing direction of the rotation locking means and the direction of the axially orthogonal component force by the pressing means are the same direction. A position adjusting mechanism of an image reading device characterized by the above.