JP2003174542A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader capable of obtaining satisfactory image quality without out-of-focus, fogging, striped image or the like by preventing deviation between a sheet guide rotator and a principal scanning read line. <P>SOLUTION: To solve the above problem, this image reader is typically configured to have an image read means for reading an original image, a sheet receiving member located between the image reading means and an original, the sheet guide rotator for guiding the original to the sheet receiving member, and an adjusting means for adjusting the position of the sheet guide rotator with respect to the sheet receiving member. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

The present invention relates to a scanner,
The present invention relates to an image reading apparatus that includes a document conveying device such as a copying machine or a facsimile device and that reads an image of the document.

[0002]

2. Description of the Related Art Conventionally, in an image reading apparatus, a document feeder such as a double-sided automatic document feeder (hereinafter referred to as ADF).
(Called Auto Document Feeder)).
When an image of an original is read while being conveyed in an image reading apparatus equipped with this type of ADF, a reading unit provided below the ADF is read by a motor at a reading position, that is, AD.
It moves to the position just below the platen roller in F and stops. Then, while irradiating light from the lamp unit, the original is conveyed between the platen roller and the platen glass,
The reflected light is detected by the reading means. Then, based on the read image data, an image is recorded on the sheet by the image forming unit, so that a copied image can be obtained.

[0003]

However, in the configuration of the above-mentioned conventional example, the mounting position of the ADF varies due to variations in ADF parts or assembly, etc.
An error may occur in the relative position between the reading position of the DF and the reading position of the reading means, which may lead to deterioration in image quality when reading the document. As a means for solving the problem, Japanese Patent Publication No. 2993810 proposes a configuration in which the reading means moves the platen roller in the sub-scanning direction (original conveying direction) to perform reading, and the position where the brightness is maximized is set as the reading position.

However, due to variations in ADF parts and assembly, and adjustment of the main scanning line of the reading means and the inclination of the ADF for vertically aligning the document feeding direction of the ADF, main scanning of the platen roller of the ADF and the reading means is performed. The lines may not be parallel, and good image quality cannot be obtained by the above method over the entire width in the main scanning direction. For example, when the position where the brightness near the center of the platen roller in the longitudinal direction is maximized is set to the reading position using the above method,
When the platen roller is tilted, a good image can be obtained near the center in the longitudinal direction, but images on both sides such as images with out-of-focus due to floating documents or fog images due to insufficient light amount A problem occurs.

Further, in the ADF, toner, ink, etc. adhering to the surface of the document being conveyed may be peeled off, and may be accumulated as dust on the platen glass. If these accumulated dusts are directly above the reading position, the reading unit may catch the dusts as an image and, as a result, may be erroneously recognized as a streak image. On the other hand, the gap between the platen roller and the platen glass is minimized, so there is an effect of self-cleaning by rubbing the originals that carry the accumulated dust, and it is remarkable as it gets closer to the position just below the platen roller. By setting the position immediately below the platen roller, it is possible to suppress the occurrence of the streak image. Therefore, if the platen roller is tilted with respect to the reading line in the main scanning direction, the image read in the part where the reading line is directly below the platen roller is not a problem, but if the platen roller is read in the part deviating from the reading line, A streak image may occur in the existing image.

Therefore, the present invention provides an image reading apparatus which can prevent the deviation between the sheet guide rotating body and the main scanning reading line and can obtain good image quality without defocusing, fog and streak images. Has an aim.

[0007]

In order to solve the above-mentioned problems, a typical structure of an image reading apparatus according to the present invention has an image reading unit for reading an image of an original document, and an image reading unit between the image reading unit and the original document. A sheet receiving member located at, a sheet guide rotating body that guides a document to the sheet receiving member, and an adjusting unit that adjusts the position of the sheet guide rotating body with respect to the sheet receiving member.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A first embodiment of the image reading apparatus according to the present invention will be described with reference to the drawings. In the present embodiment, the image reading apparatus will be described by using a copying machine including an image forming apparatus as an example. As shown in FIG. 2, the copying machine has an image reading unit 150 at the top and an image forming unit 3 at the bottom.
00, and an automatic document feeder (hereinafter referred to as A
DF2). The following will be described in order.

[Image Reading Unit] The image reading unit 150 guides a lamp 152 for irradiating the document surface with light, and reflected light from the document P corresponding to the light emitted by the lamp 152 to the lens 157 and the CCD 158. The mirrors 153, 155, 156 are included in the image reading means. The lamp 152 and the mirror 153 are attached to the reading unit 160, and the mirrors 155 and 156 are attached to an optical stand (not shown). The reading unit 160 and the optical stand are not shown in the drawing, and a wire and a motor 314 (see FIG. 15).
Is controlled in parallel with the book platen 3.

The reflected light from the original is mirrors 153, 155, 156.
Is guided to the lens 157 via the
Focused on 158. The CCD 158 photoelectrically converts the reflected light reflecting the document information and outputs it as an electronic image signal.

With such a configuration, in the state where the reading unit 160 is stopped at the reading position 60, the ADF original reading mode in which the original information is read while the original is conveyed by the ADF 2 and the original is fixed on the book platen 3. Place it on
The original information can be read in two modes: a platen glass original reading mode in which the original information is read while moving the reading unit 160 in the sub-scanning direction.

FIG. 15 is a block diagram showing a schematic configuration of a control system of the image reading section 150. A lamp 152 for irradiating the surface of the document and a reading unit 160 are moved by a sub-scanning method and a motor for scanning the document. 314, CCD 158 for photoelectrically converting the reflected light from the document surface, A for A / D converting the output signal of CCD 158
Encoder 30 connected to D / D conversion circuit 301 and motor 314
2, lamp 152 for illuminating the original, reading unit
A position sensor 315 for positioning 160 at the home position, a backup RAM 303 for setting a regular document reading position in the ADF document reading mode,
And a scanner controller 304.

The position sensor 315 is a sensor for detecting the home position of the reading unit 160,
The reading unit 160 is moved by rotating the motor 314 forward and backward with the position of the position sensor 315 as a reference, and the document on the book platen 3 is optically scanned. Motor 31
Reference numeral 4 denotes a stepping motor, to which an encoder 302 is connected, and the output of the encoder 302 allows the reader unit 160 to recognize how many pulses the reading unit 160 has moved. That is, the position of the reading unit 160 can be grasped by the encoder pulses from the position sensor 315 and the encoder 302.

The scanner controller 304 is shown in FIG.
It includes a ROM 304a in which various programs such as a program corresponding to the flowchart of 6 are stored. Further, the scanner controller 304 grasps the position of the reading unit 160 based on the encoder output and the output signal from the position sensor 315, and the means to be described later based on the output signal of the CCD 158 digitized by the A / D conversion circuit 301. The read position is adjusted by and the set position is stored in the backup RAM 303.

(Determining Document Reading Position and Detecting Platen Roller Position) Next, the document reading position detection process and the platen roller 24 position detection process will be described with reference to the flowchart of FIG. The scanner controller 304 first sets the motor 314 according to the program stored in the ROM 304a.
By controlling the driving of the reading unit 160, the reading unit 160 is moved toward the platen roller 24 from the home position by a preset number of pulses and stopped (S1).
The amount of movement at this time is set so that the reading unit 160 is located near the center position of the platen roller 24.

Next, the scanner controller 304 uses the lamp 152.
Is turned on (S2), and while the reading unit 160 is moved in a predetermined range in the sub-scanning direction, the CCD 158 reads the data on the back side in the main scanning direction (position 80 in FIG. 5) (S2).
3). Then, the maximum value of the read digital signal values is stored, and the position showing the maximum value is determined as the reading position 60 (S
4).

Next, the reading unit 160 is temporarily returned to the home position (S5), and the reading unit 160 is again moved in the direction of the platen roller 24 by the set pulse (S).
6), data reading is performed on the front side (position 81 in FIG. 5) in the main scanning direction (S7). Then, the position showing the maximum value of the digital signal value in the range and the maximum value are stored (S8).

Next, the previously determined reading position is compared with the position showing the maximum value on the front side to calculate the difference (S9). The difference is compared with a predetermined amount (S10). If the difference is smaller than the predetermined amount, OK is displayed on the operation unit (S12), the lamp is turned off (S13), and the reading unit 160 is returned to the home position (S13). S14) End. On the other hand, when the difference is larger than the predetermined amount, that is, when it is determined that the platen roller 24 of the ADF 2 is inclined more than the predetermined amount, the adjustment amount is displayed as a numerical value on the operation unit (S11), and the platen roller 24 is parallel again. Warning to adjust to, then exit.

In this process, the platen roller 24 is directly read and arithmetic processing is performed without a document.
The processing timing is not limited, such as when the DF is installed, when the power is turned on, and before the jam starts. Further, the data on the front side and the data on the back side can be processed by a single reading. Furthermore, since it is only necessary to detect the position and the inclination of the platen roller 24, it is possible to compare the data at two points that are apart from each other to some extent, and the position and the positional relationship on the front side and the back side are not particularly limited.

[Image Forming Section] The image forming section 300 is an image forming means using well-known electrostatic latent image formation. FIG. 2 is a diagram showing a schematic configuration of the image forming unit 300. In the figure, in order to supply sheets to the image forming unit 300, an upper cassette 100, a lower cassette 102, a manual feed guide 104, and a deck 108.
Is provided. The sheets in the upper cassette 100 and the lower cassette 102 are separated and fed one by one by the action of the separating claw and the feeding rollers 101 and 103, and are guided to the registration rollers 106. The sheet inserted into the manual feed guide 104 is guided to the registration roller 106 via the roller 105. deck
A middle plate 108a that is moved up and down by a motor or the like is provided inside the 108, and the sheets on the middle plate 108a are separated and fed one by one by the action of the feeding roller 109 and the separating claws and guided to the conveying roller 110.

A developing device 114, a transfer charging device 115, and a separation charging device 116 are provided around the photosensitive drum 112, which is an image carrier, and a toner image is formed by a known process and transferred to a sheet. It The image-formed sheet is conveyed by the conveying belt 117, fixed by the fixing device 118, guided by the conveying roller 119 and the diverter 120 to the discharge roller 121, and conveyed into the sorter 122. Sorter 122 includes non-sort tray 122a and sort bin tray 12
2b, a non-sort tray discharge roller 122c, and a sort bin tray discharge roller 122d. The non-sort tray 122a and the sort bin tray 122b move up and down to divide the sheets one by one. A discharge tray may be attached instead of the sorter 122.

In the case of double-sided copying or multiplex copying, the sheet after fixing is branched by the diverter 120 and conveyed by the conveying roller 201.
In the case of double-sided copying, it is reversed and stacked on the intermediate tray 200 via the belts 202 and 204, the path 206, and the discharge roller 205. In case of multiple copy, the sheet is diverter
It is loaded on the intermediate tray 200 as it is by 203. The intermediate tray 200 is provided with half-moon rollers 209 and 210 for sending out the sheet, and the sheet is re-fed to the registration roller 106 via the pair of separating rollers 211 and the conveying rollers 213, 214 and 215.

[Automatic Document Conveying Device] (Construction of Conveying Section) The ADF 2 which is an automatic document conveying device,
As shown in FIG. 1, a document tray 4 is provided above and a discharge tray 10 is provided below it. The document tray 4 is for stacking a document on which an image is to be read, and a pair of width direction regulating plates 43 are arranged so as to be slidable in the width direction of the document. The width-direction restriction plate 43 ensures the stability of document conveyance during feeding.

A feeding roller 5 is provided above the document tray 4, and the document P is fed by being driven by the rotation of the separation / conveyance roller 8. The feeding roller is normally retracted to the upper position (solid line position in the drawing) which is the home position so as not to interfere with the work of setting the original. When the feeding operation is started, the feeding roller 5 is processed at the position indicated by the dotted line in the drawing and abuts against the upper surface of the document P. The feeding roller 5 is axially supported by an arm (not shown), and is vertically moved by swinging the arm. A separation conveyance roller 8 and a separation pad 6 are arranged at the end of the document tray 4,
Pressed with a predetermined pressure. The separation pad 6 is formed of a rubber material or the like having a friction slightly smaller than that of the separation / conveyance roller 8, and separates the originals P fed by the feeding roller 5 one by one and feeds them by the separation / conveyance roller 8.

The separated and fed document P is sent to a registration roller 12 and a registration driven roller 11 which are registration means. The registration roller 12 and the registration driven roller 11 are initially stationary, and the skew of the leading edge of the document is corrected by abutting the leading edge of the separated document on the nip portion to form a loop. Then, the lead roller 22 and the lead driven roller 14 convey the document toward the platen roller 24 and the platen glass 161. The original that has passed through the platen glass 161 is picked up by the jump table 162, conveyed by the lead discharge roller 23 and the lead discharge driven roller 16, and discharged to the discharge tray 10 by the discharge roller 18. In the double-sided mode, the discharging roller 18 does not discharge the sheet, but switches back, guides it to the upper path, and feeds it again to the registration roller 12. As a result, the back side of the document is read.

(Description of Sensor) The original document P is detected on the original tray 4 by detecting the positions of the original set detection sensor 40, which is a transmissive optical sensor for detecting the setting of the original P, and the width direction regulating plate 43. A document width detection sensor 44 for detecting the length in the width direction of the document is provided. A registration sensor 7, which is a transmissive optical sensor for detecting a document, is provided between the separation / conveyance roller 8 and the registration roller 12, and detects the leading edge of the separated and fed document and abuts it on the registration roller 12. The timing to control the amount (loop amount) is detected. Further, a read sensor 13 which is a reflection type optical sensor for detecting a document is provided immediately after the read roller 22 and serves as a reference signal for the read start timing at the read position 60. Further, immediately before the discharge roller 18, a discharge sensor 17 which is a transmissive optical sensor for detecting a document is provided to detect a document discharge timing and the like.

(Description of Drive System) FIG. 3 is a view showing a drive system showing a motor and solenoids for driving each roller and the like. The separation solenoid 57 drives the feeding roller 5 to swing. The separation solenoid 57 is a keep solenoid that holds and holds the feeding roller 5 above the home position (the solid line position in the figure) and holds it in a position where it does not interfere with setting the original. Separation solenoid 57 during feeding operation
The holding force is turned off to descend, and the feeding roller 5 is pressed against the uppermost sheet of the sheet original on the original tray 4. Separation motor 51
Is a stepping motor, which rotationally drives the separating and conveying roller 8 and the feeding roller 5 in the conveying direction. The lead motor 53 includes the registration roller 12, the lead roller 22, and the platen roller 2
4, a stepping motor that drives the lead discharge roller 23. Each roller is driven at a speed at which the image of the conveyed document is read. The discharge motor 50 is a stepping motor that drives the discharge roller 18.

(Structure of Control Circuit) FIG. 14 is a block diagram showing the structure of the control circuit of the ADF 2 of this embodiment. The control circuit is mainly composed of a CPU 54 (microprocessor), and drive circuits for various loads and sensor signals are connected to the input / output ports of the CPU 54. The control circuit is a RAM backed up by a battery (not shown).
And a ROM storing control sequence software. A communication IC 55 for controlling data communication with the copying machine main body 56 is connected to the CPU 54.

The separation motor 51, the lead motor 53, and the discharge motor 50 are driven by each stepping motor driver. A phase excitation signal and a motor current control signal are input from the CPU 54 to each driver. Separation solenoid 57
Is driven by a driver and its operation is controlled by a signal connected to the input / output port of the CPU 54. Registration sensor 7, document set detection sensor 40,
Various sensors such as the lead sensor 13, the discharge sensor 17, and the document width detection sensor 44 are connected to the input port of the CPU 54,
It is used to monitor the behavior of the original document in the apparatus and the behavior of the movable load.

(Structure of Reading Unit) As shown in FIG. 4, a platen glass 161 serving as a sheet receiving member for reading.
On the opposite side of the platen roller 24
Are arranged. The platen roller 24 is rotated at the same peripheral speed as the lead roller 22. The platen roller 24 is formed of a rubber roller whose surface is white, and is configured so that even a thin transparent document is not affected by the roller surface during image reading.

The platen roller 24 is arranged with a slight gap (about 0.2 mm to 0.5 mm) with respect to the platen glass 161. As shown in FIG. 5, the platen roller 24 is pivotally supported at both ends by a swingable front arm 66 and a rear arm 67, and is urged against the platen glass 161 by a spring (not shown). As a result, the platen roller 24 is configured to softly escape when a thick document enters. Note that the above-mentioned gap is ensured by contacting part of the front arm 66 and the rear arm 67 with the platen glass 161.

The reading position 60 is set just below the platen roller 24. The document P being conveyed is guided by the platen roller 24, but the document P takes a curved locus with the position immediately below the platen roller 24 as the lowest position. The locus of the curved original P is influenced by the position of the platen roller 24. Immediately below the platen roller 24, there is almost no document floating, and there are no image defects such as out-of-focus images and fog. Platen roller 24
The farther away from directly below the document, the more it floats from the platen glass 161. Therefore, if the readable area, that is, the reading position 60 is within a predetermined range centering on the platen roller center 63, that is, a range from reference numeral 61 to reference numeral 65 in FIG.

Further, the toner, ink, etc. adhering to the surface of the document being conveyed may be peeled off, and the platen glass 16
May accumulate above 1. If these accumulated dusts are right above the original reading position, the original reading unit
The dust may be captured as an image and, as a result, may be erroneously recognized as a streak image and read. However, since the gap between the platen roller 24 and the platen glass 161 is minimized, the document P carrying the accumulated dust is conveyed. There is an effect of self-cleaning by the rubbing of the sheet, and it becomes more noticeable as the gap is narrower and immediately below the platen roller. This range is narrower than the readable area, and if the reading position 60 is between the reference numerals 62 to 64 in FIG. 4, there is almost no possibility that a streak image will occur. For these reasons, by disposing the reading position 60 in the range of reference numerals 62 to 64, it is possible to prevent out-of-focus images, fog, and general defects of images including streak images from occurring.

(Adjustment of Platen Roller Position) There are cases where the main scanning line of the image reading unit 150 and the platen roller 24 of the ADF 2 are not parallel due to parts of the ADF 2, such as a hinge mechanism, a platen roller supporting mechanism, etc. and variations in assembly. . Also, by adjusting the inclination of the ADF 2 to adjust the document feeding direction of the ADF 2 to be vertical, which will be described later,
The main scanning line of the image reading unit 150 and the platen roller 24 of the ADF 2 may not be parallel. Even in such a case, in order to obtain a good image quality in the entire width in the main scanning direction, the present embodiment is provided with a platen roller position adjusting mechanism.

FIG. 5 is a plan view showing the periphery of the platen roller 24, and FIG. 6 is a front view showing the periphery of the platen roller 24.
Rotational drive is transmitted to the platen roller 24 from the back side, and is transmitted from the drive shaft 41 via the pulley 42, the belt 68, and the pulley 69. The platen roller 24 is pivotally supported by a rear arm 67 and a front arm 66.

The fulcrum side of the front arm 66 is held by an adjusting plate 58 and a shaft 48 fixed to the adjusting plate 58.
It is fixed to the fixed frame 47 with. The adjustment plate 58 can be fixed by adjusting it to the left and right, and can be aligned with the index 45 of the frame 47. That is, these adjusting plate 58, the shaft
48 and the index 45 constitute an adjusting means for adjusting the position of the platen roller 24 with respect to the platen glass 161. Therefore, since the platen roller 24 can be fixed by changing the position on the front side around the back side as indicated by the two-dot broken line in the figure, the main scanning reading line of the image reading unit 150 and the platen roller 24 can be made parallel. .

The position of the platen roller is adjusted by the image reading unit.
Platen roller 2 as described in Reading position detection of 150
When it is recognized that 4 is parallel, it is OK, and when it is judged that the readable range code 62 to code 64 is out of the full width, the adjustment amount is displayed on the operation unit. Based on this, the position of the adjusting plate 58 is moved to match the instructed index, so that the reading line in the main scanning direction and the platen roller 24 become parallel, and the reading position 60 is from the readable area 62 to 64. The platen roller 24 can be aligned so that it lies between. The position of the platen roller 24 is adjusted after the ADF position adjustment (squareness adjustment) described later.

(Hinge mechanism) Referring to FIGS. 9 to 12, A
The hinge mechanism of DF2 will be described. The ADF 2 is provided with hinge mechanisms 95 and 96 in the image reading unit 150 in order to open and close the platen glass 161 and the book platen 3 (see FIG. 2). Figure 9 shows the ADF from the back of the device.
The figure which looked at 2 is shown. Inside the casing 52 of the ADF 2, hinge mechanisms 95 and 96 are installed on the left and right.

As shown in FIG. 10, the hinge mechanisms 95 and 96 support the ADF 2 with respect to the image reading section 150 so as to be openable and closable about the hinge shaft 71. The hinge mechanisms 95 and 96 include a lift arm 74, a lift shaft 75, a lower spring shaft 76, and a hinge arm 7.
7, height adjusting screw 78, hinge shaft 71, hinge base 84, lower spring holder 85, compression spring 86, upper spring holder 87, upper spring shaft 88 and the like. The hinge shaft 71 is supported by the hinge base 84. The hinge base 84 is an image reading unit.
It is fixed to the body of 150. In addition, the hinge shaft 71,
A hinge arm 77 is provided so as to be rotatable with respect to the hinge base 84. Further, the hinge arm 77 supports the lift arm 74 via the lift shaft 75. Therefore, the lift arm 74 is rotatable with respect to the hinge arm 77. The height adjusting screw 78 is screwed into the lift arm 74. The tip of the height adjustment screw 78 has a hinge arm.
ADF for Book Platen 3 by touching part of 77
The height of 2 can be adjusted.

The lift arm 74 is fixed to the casing 52 and supports the upper spring shaft 88. The upper spring shaft 88 is provided on the upper spring holder 87. The upper spring holder 87 holds one end of the compression spring 86. The lower spring holder 85 is provided on the lower spring shaft 76 and holds the other end of the compression spring 86. Since the lower spring shaft 76 is fixed to the hinge base 84, the upper spring shaft 88 is opened and closed with the opening / closing operation of the ADF 2.
The distance between the lower spring shaft 76 and the lower spring shaft 76 changes, and the compression spring 86 expands and contracts.

Casing with built-in hinge mechanisms 95, 96
As shown in FIG. 12, an opening 93 formed by cutting out the casing 52 is provided in each of both sides of the casing 52 as a relief when the ADF 2 is completely opened as shown in FIG. The outside of the opening 93 is covered with a hinge mechanism protection cover 89 as shown in FIG. 10 to 12
Although only the left side opening is described in the above, the same applies to the configuration of the right side opening. Hinge mechanism protective cover
A part of the upper end of the 89 is fixed to the casing 52, and covers the inside of the hinge to prevent foreign matter and the like from entering. EPDM (ethylenepyropyrene rubber) type rubber sheet is used for the hinge mechanism protection cover 89, and it can be easily molded, is elastic and bends freely, and it can return to its original shape by its own weight. Has become. Guard plate 9
0, 91 and 92 are molded of ABS (acrylonitrile / butadiene / styrene terpolymer) and fixed to the hinge mechanism protection cover 89. Therefore, even if the hinge mechanism protection cover 89 is deformed, the guard plates 90, 91,
The 92 does not easily deform or come off. The guard plates 90, 91, 92 guard against damage to the hinge mechanisms 95, 96 even when they are brought into contact with a wall, a protrusion, or the like during transportation and an external force acts.

FIG. 10 shows a case where a thick manuscript having a height h, such as a dictionary, is placed on the book platen 3.
The lift arm 74 is rotated with respect to the hinge arm 77, and the white pressure plate and the ADF 2 are equalized in parallel with the book platen 3. At this time, the compression spring 86 is compressed and assists the opening operation of the ADF 2. FIG. 11 shows the ADF 2 half opened. At this time, the ADF 2 can be opened and closed in the arrow B direction with respect to the image reading unit 150. FIG. 12 shows the state in which the ADF 2 is completely opened. At this time, the compression spring 86 is expanding. Therefore, when the ADF 2 is closed, it can be closed with a small force. In this way, the hinge mechanism 95, 96
Causes the compression spring 86 to expand and contract as the ADF2 opens and closes.
It is designed to help open and close the ADF2.

(Adjustment of ADF position) ADF2 is used as an image reading unit.
By adjusting the tilt with respect to 150, you can adjust the squareness of the image. FIG. 13 is a diagram showing the periphery of the upper surface of the image reading unit 150. ADF2 is attached by the hinge mechanism of ADF
The hinge base 84, which is the base of 95 and 96, is the image reading unit 150.
Connected to the upper surface of. Hinge mechanism 96 Hinge base 84
Is fixed with screws 97 to determine its position. On the other hand, in the hinge base 84 of the hinge mechanism 95, the mounting holes for the screws 98 and 99 are elongated holes, and the image reading unit 150 can be moved and adjusted in the vertical direction as indicated by an arrow 72 in FIG. As a result, the ADF 2 can be tilted about the mounting screw 97 of the left hinge.
Adjust so that the document feed direction of DF2 is vertical and AD
It is possible to fix F2. By adjusting at right angles,
Since the original is not read diagonally, a distorted image is never read.

[Other Embodiments] Other embodiments of the image reading apparatus according to the present invention will be described with reference to FIGS. FIG. 7 is a plan view showing the periphery of the platen roller 424,
FIG. 8 is a front view showing the periphery of the platen roller 424,
The same parts as those in the first embodiment will be designated by the same reference numerals and the description thereof will be omitted.

Rotational drive is transmitted to the platen roller 424 from the back side, and the platen roller 424 is pivotally supported by the back side arm 467 and the front side arm 466. A back side index 402 and a front side index 401 are arranged on the platen glass 161, and each of the front and back indexes is the image reading unit 150.
It is shown parallel to the side main scan line. For example, the back side index 40
The line connecting the rightmost index of 2 and the rightmost index of the front side index 401 is parallel to the main scanning line.

The fulcrum side of the front arm 466 is held by an adjusting plate 443 and a shaft 448 fixed to the adjusting plate 443.
Fixed to frame 447 with 6. The screw 446 is fitted in the long hole, and the adjustment plate 443 can be fixed by adjusting the position to the left and right. A pointer 400 is formed on a part of the front arm 466, a pointer 403 is arranged on a part of the back arm 467, and the pointers 400 and 403 point to the indexes 401 and 402, respectively.

In the structure according to the present embodiment, the reading position detection of the image reading section 150 described in the first embodiment is not necessary. That is, based on the index pointed by the back side pointer 403 to the back side index 402, by adjusting the position of the platen roller 424 so that the front side index 401 points to the same index as the front side pointer 401, a reading line in the main scanning direction is obtained. The platen roller 424 becomes parallel. Therefore, as in the first embodiment, the reading position 60 is a readable area 62
The platen roller 424 can be aligned so that it is between the number and 64 (see FIG. 4). As a result, good image quality can be obtained over the entire width in the main scanning direction.

[0048]

As described above, in the image reading apparatus according to the present invention, by having the adjusting means for adjusting the position of the sheet guide rotating member with respect to the sheet receiving member, the main scanning reading line and the sheet guiding rotation are provided. The body and the body can be adjusted substantially parallel to each other, and the body can be placed at the optimum reading position. This makes it possible to obtain good image quality without out-of-focus blur, fog, and streak images.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration of an image reading unit and an automatic document feeder.

FIG. 2 is a diagram illustrating a configuration of an image forming unit.

FIG. 3 is a diagram illustrating a drive system of an automatic document feeder.

FIG. 4 is an enlarged view of a main part of an image reading unit.

FIG. 5 is a plan view showing the periphery of a sheet guide rotating body.

FIG. 6 is a front view showing the periphery of a sheet guide rotating body.

FIG. 7 is a plan view showing the periphery of a sheet guide rotating body according to another embodiment.

FIG. 8 is a front view showing the periphery of a sheet guide rotating body according to another embodiment.

FIG. 9 is a view of the automatic document feeder viewed from the rear side of the apparatus.

FIG. 10 is a diagram illustrating a state of the hinge mechanism when a thick document is placed.

FIG. 11 is a diagram illustrating a state of the hinge mechanism when the automatic document feeder is half opened.

FIG. 12 is a diagram illustrating a state of the hinge mechanism when the automatic document feeder is completely opened.

FIG. 13 is a diagram showing the periphery of the upper surface of the image reading unit.

FIG. 14 is a block diagram showing a configuration of a control circuit of the automatic document feeder.

FIG. 15 is a block diagram showing a schematic configuration of a control system of an image reading unit.

FIG. 16 is a flowchart illustrating a process of detecting a document reading position and a position of a sheet guide rotating body.

[Explanation of symbols]

P ... manuscript 2 ... ADF 3… Book Platen 4… Original tray 5 ... Feeding roller 6 ... Separation pad 7 ... Registration sensor 8 ... Separation / conveyance roller 10… Ejection tray 11… Regist driven roller 12… Registration roller 13… Lead sensor 14-Lead driven roller 16… Lead discharge driven roller 17… Emission sensor 18… Ejection roller 22… Lead roller 23… Lead discharge roller 24… Platen roller 40… Original set detection sensor 41… Drive shaft 42 ... pulley 43… Width direction control plate 44… Original width detection sensor 45… Indicator 46… screws 47… Frame 48… Axis 50… Discharge motor 51… Separation motor 52… Casing 53… Lead motor 54 ... CPU 55… Communication IC 56… Copier body 57… Separation solenoid 58… Adjusting plate 60… Reading position 63… Platen Roller Center 66… Front arm 67… Back arm 68… Belt 69… pulley 71… Hinge axis 72… Arrow 74… Lift arm 75… Lift shaft 76… Lower spring shaft 77… Hinge arm 78… Height adjustment screw 84… Hinge base 85… Lower spring holder 86… Compression spring 87… Upper spring holder 88… Upper spring shaft 89… Hinge mechanism protection cover 90, 91, 92… Guard plate 93… Opening 95, 96 ... Hinge mechanism 97, 98, 99… Screw 100… Upper cassette 101 ... Feeding roller 102 ... Lower cassette 103… Feeding roller 104… Manual feed guide 105 ... Laura 106… Registration roller 108… Deck 108a ... Middle plate 109… Feeding roller 110… Conveyor roller 112 ... Photosensitive drum 114 ... Developer 115… Transfer charger 116… Separation charger 117… Conveyor belt 118… Fixing device 119 ... Conveyor roller 120… diverter 121… Ejection roller 122… Sorter 122a… Non-sort tray 122b ... Sort bin tray 122c… Non-sort tray discharge roller 122d ... sort bin tray discharge roller 150… Image reading section 152… Lamp 153, 155, 156… Mirror 157… Lens 158… CCD 159… Daiichi Optical Platform 160… Reading unit 161… Platen glass 162… Jump platform 200… Intermediate tray 201… Conveyor roller 202… Belt 203… Diverter 204… Belt 205… Ejection roller 206 ... pass 209, 210 ... Half moon Laura 211… Separation roller pair 213, 214, 215 ... Conveying rollers 300 ... Image forming section 301… A / D conversion circuit 302… Encoder 303… Backup RAM 304… Scanner controller 304a ... ROM 314… Motor 315… Position sensor 400… Guidelines 401… Front index 402… Inner index 403… Guidelines 424 ... Platen roller 443… Adjustment plate 446… Screw 447… Frame 448… Axis 466… Front arm 467… Rear arm

Continued front page    F term (reference) 2H027 DA23 DB03 DB10 DE02 GA50                       GB05 HA02 HA12 HB05 HB16                 2H076 BA24 BA41                 3F049 AA03 AA10 DA14 LA01 LA05                       LA07 LB02                 5C062 AA02 AA05 AB02 AB17 AB32                       AB33 AB41 AB42 AC11 AC58                       AD06                 5C072 AA01 BA17 CA02 DA02 DA04                       EA05 NA01 XA01

Claims (3)

[Claims] 1. An image reading unit for reading an image of a document, a sheet receiving member located between the image reading unit and the document, a sheet guide rotating body for guiding the document to the sheet receiving member, and the sheet guide. An image reading apparatus comprising: an adjusting unit that adjusts a position of a rotating body with respect to a sheet receiving member. 2. The apparatus according to claim 1, further comprising an index indicating a position of the sheet guide rotating body, wherein the adjusting unit can adjust the position of the sheet guide rotating body based on the index. Image reading device. 3. A detecting means for detecting the position of the sheet guide rotating body, wherein the adjusting means is capable of adjusting the position of the sheet guide rotating body based on the output of the detecting means. The image reading apparatus according to claim 1.