JP2002300349A - Structure for light receiving section of image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for a light receiving section of an image reader that eliminates the need for adjustment at a site by integrating an image forming lens and a photoelectric conversion device in advance so as to build the light receiving section, adjusting the light receiving section in a state similar to that being incorporated in a test device so as to enhance the optical performance and substituting the adjusted light receiving section for a light receiving section of an image reader possessed by a user. SOLUTION: An image forming lens 6 and a photoelectric conversion device 7 are mounted on a base plate 21 to assemble the light receiving section 20. The light receiving section 20 is brought into a state similar to that of an image reader 1 to which the light receiving section 20 is assembled, fitted to the test device, and adjusted to enhance the prescribed optical performance. The adjustment on site is simplified by replacing the light receiving section 20 of the image reader 1 possessed by the user with the adjusted light receiving section 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stationary document type image reading apparatus which irradiates a document with light from a light source lamp and reads image information formed on the document from the reflected light. The present invention relates to a light receiving unit structure of an image reading apparatus to which a light receiving unit including a photoelectric conversion device for capturing data and converting data relating to an image into an electric signal is attached.

[0002]

2. Description of the Related Art An image reading apparatus, such as a copying machine or a scanner, which reads an image of a document shown on a sheet of paper and performs various processings, irradiates the document with light from a light source lamp such as a fluorescent lamp and reflects the reflected light. Is incident on a light receiving unit provided with a photoelectric conversion device such as a CCD. The light receiving unit includes the photoelectric conversion device and an imaging lens that forms an image on the photoelectric conversion device,
These imaging lenses and the photoelectric conversion device must be in a predetermined positional relationship.

[0003] On the other hand, a reflector or the like is used to guide the light reflected by the document to the light receiving section. In an original reading type image reading apparatus, it is necessary to keep the optical path length from the original to the light receiving section constant even when the irradiation position on the original changes, so that the reflecting mirror or the like is moved along the original. It is. The light reflected by the reflecting mirror must also appropriately enter the imaging lens. That is, the optical axes of the reflecting mirror, the imaging lens, and the photoelectric conversion device must match.

For example, as described in the image reading unit of Japanese Patent Application Laid-Open No. H8-110592, the photoelectric conversion device is formed into a unit together with an imaging lens. The magnification is adjusted by aligning the optical axis with the device and moving the unit in the optical axis direction.

[0005]

When the image reading apparatus has been used for a long period of time, a photoelectric conversion device such as a CCD may not exhibit desired performance due to deterioration or the like. In such a case, it is necessary to replace the photoelectric conversion device.

Conventionally, when replacing a photoelectric conversion device, a photoelectric conversion device whose position has been adjusted with respect to a reference reflecting mirror or imaging lens at a factory or the like is attached to an image reading apparatus. Then, in the mounted state, position adjustment such as matching the optical axis to the imaging lens of the unit attached to the image reading apparatus is performed. For this reason, two adjustments before and after the shipment are required, and a part for performing the adjustment is required, thereby increasing the number of parts for replacement. Moreover, the adjustment work becomes complicated, and the adjustment in the field, in particular, is performed while confirming the read image, so that a considerable time is required for the adjustment.

Further, even when the entire unit including the imaging lens and the photoelectric conversion device is replaced, it is necessary to adjust the magnification by moving the unit in the direction of the optical axis, which requires an on-site adjustment operation.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a light receiving unit structure of an image reading apparatus capable of exchanging a photoelectric conversion device without performing complicated adjustment on site at the time of mounting.

[0009]

As a technical means for achieving the above object, a light receiving portion structure of an image reading apparatus according to the present invention connects an image formed on a document via an appropriate optical system. In an image reading device that guides the image lens and captures an image by forming the image on a photoelectric conversion device with the imaging lens, a light receiving unit including the imaging lens and the photoelectric conversion device includes a light receiving unit including these imaging lenses. Attached to the substrate so that the positional relationship with the light source conversion device can be adjusted, on the substrate,
An installation position storage unit that stores an installation position of the light receiving unit in the image reading device is provided, and an installation position of the light receiving unit is adjusted in advance by a reference image reading device and stored in the installation position storage unit. When the light receiving unit is incorporated in an image reading apparatus to be mounted, the light receiving unit is installed together with the substrate with reference to the installation position storage unit.

When assembling the light receiving unit, the light receiving unit is assembled on the substrate so as to have a predetermined positional relationship in a state where the light receiving unit is assembled in a desired image reading apparatus, and the optical axis of the imaging lens and the photoelectric conversion device is adjusted. To complete the light receiving section. By exchanging the light receiving section with the existing one for each substrate, the imaging lens and the photoelectric conversion device are simultaneously exchanged.

In addition, since the light receiving section is pre-adjusted to the reference image reading apparatus and the installation position is stored in the installation position storage section, the image reading apparatus to which this installation position storage section is to be mounted at the time of mounting. If it is installed in accordance with a reference point provided on a housing or the like, it can be incorporated in a predetermined positional relationship with an optical member such as a reflecting mirror. This allows
The optical axis can be made coincident with the reflecting mirror or the like, the optical path can be set to a predetermined length, a predetermined magnification can be obtained, and almost no adjustment work is required at the mounting site.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a light receiving section of an image reading apparatus according to the present invention will be specifically described below based on a preferred embodiment shown in the drawings.

FIGS. 5 to 7 show a schematic structure of an original reading type image reading apparatus 1 suitable for providing the light receiving section structure. FIG. 5 is a perspective view, FIG. FIG.
Is a side view. Two guide plates 2b and 2e are provided in a shelf shape on the inner surface of the longitudinal wall 2a of the housing 2 of the image reading device 1.
The full-rate carriage 3 and the half-rate carriage 4 are mounted on the guide plates 2b and 2e, respectively.
To move in the longitudinal direction of the housing 2. A platen glass (not shown) is attached to the upper surface of the housing 2, and a document is placed on the platen glass. A light source lamp 5 such as a fluorescent lamp is mounted on the full rate carriage 3, and the light source lamp 5 irradiates a document. An imaging lens 6 and a photoelectric conversion device 7 such as a CCD (charge imaging element) are provided at appropriate positions on the bottom plate 2 c of the housing 2.
Is provided.

The full-rate carriage 3 is provided with a first reflecting mirror (not shown), and the half-rate carriage 4 is provided with second and third reflecting mirrors (not shown). The light emitted by the light source lamp 5 and reflected by the original is
The first reflecting mirror, the second reflecting mirror, and the third reflecting mirror sequentially reflect the light, pass through the imaging lens 6, and enter the photoelectric conversion device 7, and the first reflecting mirror and the second reflecting mirror. An optical path from the document to the photoelectric conversion device 7 is formed by the mirror and the third reflecting mirror. When obtaining image information of a document, the entire area of the document must be irradiated, so that the full rate carriage 3 is movable over the entire area of the platen glass. Due to the movement of the full-rate carriage 3, the length of the optical path to the photoelectric conversion device 7 must be constant. For this reason, the half-rate carriage 4 moves in synchronization with the full-rate carriage 3 by a movement amount of approximately half of the movement amount of the full-rate carriage 3 so that the optical path has a constant length.

FIG. 8 is a perspective view schematically showing a driving mechanism for moving the carriages 3 and 4 in synchronization. A drive shaft 8 having an axial direction perpendicular to the scanning direction of the carriages 3 and 4 is rotatably supported at one longitudinal end of the housing 2, and a driven pulley 8 a is provided at a central portion thereof. It is fitted. On the other hand, the motor 9 is mounted on the bottom plate 2c of the housing 2.
A drive pulley 9a is fitted on the output shaft of the motor 9. A first drive belt 11a is stretched over the drive side pulley 9a and the first intermediate pulley 10a, and a second intermediate pulley 10b formed integrally with the first intermediate pulley 10a and the driven side pulley 8a. The second drive belt 11b is stretched. That is,
The output rotation of the motor 9 is appropriately decelerated and the driven pulley 8
a, and the drive shaft 8 rotates at a low speed. For this reason, the rotation of the drive shaft 8 becomes smooth, and vibration when the carriages 3 and 4 driven by the drive shaft 8 move can be suppressed. In particular, the suppression of the vibration is advantageous in reducing the size of the image reading apparatus.

A take-up pulley 13 is provided at both ends of the drive shaft 8.
The central portion of the wire 14 is wound around the winding pulley 13 with an appropriate number of turns. On the side surface of the half-rate carriage 4, a pair of guide pulleys 15,
Reference numeral 16 is rotatably supported about an axis perpendicular to the scanning direction. A guide pulley 17 is rotatably supported at an end of the housing 2 opposite to the side on which the drive shaft 8 is provided, with a direction orthogonal to the scanning direction as an axis. A bracket 2d is provided at an appropriate position on the wall 2a of the housing 2. The take-up pulley 13, the wire 14, the guide pulleys 15, 16, 17, and the bracket 2d are provided inside the housing 2 and on both sides of the scanning area of the carriages 3, 4.

The wire 14 has one end fixed to the bracket 2d and the guide pulley 15 positioned on the side opposite to the full rate carriage 3 is wound.
It is connected to the full-rate carriage 3 by a connecting portion 18, the winding pulley 13 is wound, the guide pulley 17 and the guide pulley 16 are sequentially wound, and a tension spring 19 having a tension coil spring or the like at the other end. Through the side wall of the housing 2.

1 to 4 are views showing the structure of the light receiving section 20. FIG. The light receiving unit 20 is configured by assembling the imaging lens 6, the photoelectric conversion device 7, and the like on a base plate 21, which is a substrate, to form a unit. As shown in FIG. 3, the base plate 21 is appropriately bent and formed, and leg portions 22 are formed at both ends in a direction orthogonal to the optical axis direction of the imaging lens 6. A substantially horizontal support base 23 is formed from the upper end of the leg 22, and an adjustment leg 24 as an installation position storage unit is fixed to one support base 23 by an adjustment screw 24 a. An elongated hole 24b having a longitudinal direction extending along the optical axis direction of the imaging lens 6 is formed in a portion of the adjusting leg portion 24 overlapping the support base portion 23, while the adjusting screw is formed in the support base portion 23. A through hole through which the through hole 24a can be formed is formed. By changing the position of the elongated hole 24b with respect to the adjusting screw 24a through which the through hole is inserted, the position of the adjusting leg 24 with respect to the base plate 21 can be adjusted. It is like that. The adjusting leg 24 has a fixing hole 24c and a fixing long hole 24d. Image reading device 1
A pair of positioning pins 2 are provided at predetermined positions on the bottom plate 2c of the housing 2.
01 and 202 (see FIG. 6) are implanted, and these positioning pins 201 and 202 are fitted into the fixing holes 24c and the fixing long holes 24d, respectively.

The leg 22 on the side opposite to the side on which the adjusting leg 24 is attached is formed with an elongated hole 22a whose longitudinal direction is the optical axis direction of the imaging lens 6. The leg 22 on the side to which the adjustment leg 24 is attached has a pair of elongated holes 22 with the optical axis direction of the imaging lens 6 as the longitudinal direction.
b, 22c are formed. Then, the image reading device 1
The bottom plate 2c is formed with through holes at positions corresponding to the long holes 22a, 22b, 22c.
a, 22b, 22c and the fixing holes 31
Thereby, the base plate 21 is fixed to the housing 2.

A lens support bracket 25 is attached to the center of the support base 23, and the imaging lens 6 is attached to the lens support bracket 25. In order to allow the mounting position of the lens support bracket 25 to be adjusted slightly with respect to the support base 23, the support base 23 and the lens support bracket 25 must be connected to each other by a fixing screw 26 for fixing them. The formed through-hole is slightly larger than the outer diameter of the fixing screw 26.

A board bracket 27 is attached to the end of the support plate 23.
A device substrate 28 on which the photoelectric conversion device 7 is mounted is attached. In order to allow the mounting position of the board bracket 27 to be adjusted slightly with respect to the support base 23, a transparent screw formed between the support base 23 and the board bracket 27 for inserting a fixing screw 29 for fixing them is inserted. The hole is slightly larger than the outer diameter of the fixing screw 29. Also, the device board 2 with respect to the board bracket 27
The through holes formed in the board bracket 27 and the device board 28 for allowing the fixing screws 30 for fixing them to be inserted so that the mounting positions of the fixing screws 8 can be adjusted slightly. Is also slightly larger.

The operation of the light receiving unit structure of the image reading apparatus according to the embodiment of the present invention will be described below.

A lens support bracket 25 on which the imaging lens 6 is mounted on the base plate 21 and a device substrate 28 on which the photoelectric conversion device 7 such as a CCD is mounted are mounted. At this time, these lens support brackets 2
By attaching the device 5 and the device substrate 28, the positional relationship between the imaging lens 6 and the photoelectric conversion device 7 is maintained in a constant state. The positional relationship can be adjusted by slightly moving the lens support bracket 25 and the device substrate 28 as needed.

The adjusting leg 24 is attached to the base plate 21 on which the imaging lens 6 and the photoelectric conversion device 7 are attached, and the light receiving section 20 is assembled. The assembled light receiving unit 20 is connected to the image reading apparatus 1 in which the light receiving unit 20 is incorporated.
Adjust according to the conditions. For example, a tester of the same type as the image reading device 1 is used as a reference image reading device, and the light receiving unit 20 is incorporated in the tester, and the tester is set in such a manner that a desired image can be obtained. The positional relationship of the light receiving unit 20 is adjusted. At this time, the fixing holes 24c and the fixing long holes 24d of the adjusting leg portions 24 are aligned with the positioning pins 20.
1, 202. The adjusting screw 24a is appropriately loosened to make the base plate 21 slidable with respect to the adjusting leg 24, and the base plate 21 is moved in the optical axis direction of the light receiving unit 20 to adjust the positional relationship. I do. When the adjustment screw 24a is tightened in the state where the adjustment is completed and the adjustment leg 24 and the base plate 21 are fixed, the light receiving unit 2 can be connected to the tester.
0 is a state where the positional relationship is set such that a predetermined optical performance can be exhibited.

As described above, the light receiving unit 20 of the image reading apparatus 1 owned by the user has the light receiving unit 20 adjusted at a factory or the like.
Replace with 0. In the image reading apparatus 1 owned by the user, the positioning pins 201 and 202 are implanted on the bottom plate 2 c of the housing 2.
2, the fixing hole 24 c and the fixing long hole 24 of the adjusting leg 24.
The light receiving portion 20 is positioned together with the base plate 21 by fitting d. And the long holes 22a, 22 of the base plate 21
The light receiving unit 20 is fixed to the housing 2 together with the base plate 21 by fastening the fixing screws 31 to the holes 22 b and 22 c and the through holes of the bottom plate 2 c. In this state, since the light receiving unit 20 is adjusted in the tester corresponding to the image reading device 1 owned by the user, the light receiving unit 20 is already appropriately adjusted for the image reading device 1 of the user, and Little adjustment is needed.

[0026]

As described above, according to the light receiving portion structure of the image reading apparatus according to the present invention, the light receiving portion including at least the imaging lens and the photoelectric conversion device is integrated with the existing light receiving portion. Since the optical performance of the light receiving unit is adjusted in advance, the optical receiver can be replaced on site. In addition, since the substrate provided with the light receiving unit may be replaced with reference to the installation position storage unit, the replacement operation is simplified. In addition, since the light receiving unit is replaced with a light receiving unit whose optical relationship has been adjusted by the reference image reading device, adjustment work on site is hardly required, and components for adjustment are unnecessary, and the number of components can be reduced. it can.

[Brief description of the drawings]

FIG. 1 is a plan view of a light receiving unit having a light receiving unit structure of an image reading apparatus according to the present invention.

FIG. 2 is a front view of a light receiving unit shown in FIG.

FIG. 3 is a rear view of the light receiving unit shown in FIG.

FIG. 4 is a side view of the light receiving section shown in FIG.

FIG. 5 is a perspective view illustrating the outline of the structure of an image reading apparatus suitable for providing the light receiving unit structure.

FIG. 6 is a plan view schematically illustrating the structure of an image reading apparatus suitable for providing the light receiving unit structure.

FIG. 7 is a side view illustrating the outline of the structure of an image reading apparatus suitable for providing the light receiving unit structure.

FIG. 8 is a schematic perspective view for explaining a drive mechanism of a carriage of an image reading apparatus of a stationary original type suitable for providing a light receiving unit structure according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image reading apparatus 2 Housing 2a Wall 2d Bracket 201 Positioning pin 202 Positioning pin 3 Full rate carriage 4 Half rate carriage 8 Drive shaft 8a Driven pulley 9 Motor 9a Drive side pulley 10 Intermediate pulley 13 Winding pulley 14 Wire 15 Guide pulley 16 Guide pulley 17 Guide pulley 18 Connecting portion 19 Tension spring 20 Light receiving portion 21 Base plate 22 Leg 24 Adjusting leg 24a Adjusting screw 24c Fixing hole 24d Fixed long hole 25 Lens support bracket 27 Board bracket 28 Device board

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tetsuo Obata 1-324 Uetake-cho, Omiya-shi, Saitama Fuji Photonics Co., Ltd. (72) Inventor Hideshi Sekiguchi 2--20-15 Shimbashi, Minato-ku, Tokyo Ideal Inside the Science Industry Co., Ltd. (72) Inventor Akira Yasuda 2-20-15 Shimbashi, Minato-ku, Tokyo R-Science Industry Co., Ltd. F-term (reference) DB28 DC02 DC04 DC07 DE21 FA01 5C072 AA01 BA02 CA02 DA02 DA04 DA23 EA05 FB06 XA01

Claims (1)

[Claims] 1. An image reading apparatus for guiding an image formed on a document to an imaging lens via an appropriate optical system, and capturing the image by forming the image on a photoelectric conversion device with the imaging lens. A light receiving unit including the imaging lens and the photoelectric conversion device is mounted on a substrate so that the positional relationship between the imaging lens and the light source conversion device can be adjusted. When an installation position storage unit for storing is provided, the installation position of the light receiving unit is adjusted in advance by an image reading device serving as a reference and stored in the installation position storage unit. A light receiving unit for the image reading apparatus, wherein the light receiving unit is installed together with the substrate with reference to the installation position storage unit.