JP2002209068A - Original reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a reference member from getting a taint damage and reads the reference member in the same state as that when an original image is read so as to accurately correct shading at all times. SOLUTION: A reference sheet 5 is wound and stored on a circumferential face of a winding roller 4 whose shaft is supported at a downstream side of a platen roller 3 in an original carrying direction and by turning the winding roller 4, the reference sheet 5 is made to feely move between an escape position and an exposed position with respect to an original read position P located between the platen roller 3 and a contact glass plate 21. In the case of reading an original image, the reference sheet 5 is wound on the circumferential face of the winding roller 4 to be located at an escape position and only at reading of shading correction data, the reference sheet 5 is exposed at the original read position P so that shading correction data are read from the reference sheet 5 in the same state as that as reading of the original image. Furthermore, the reference sheet 5 is not in contact with an original D so as to prevent the reference sheet 5 from getting dirt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document reading apparatus for performing shading correction for correcting a reading level of a document image based on a reading result of a reading sensor unit for a reference density.

[0002]

2. Description of the Related Art In a document reading apparatus which generates image data of a document based on a light receiving signal of a reading sensor which receives reflected light of light from a light source on a document image surface, an amount of light received by the reading sensor and an image density of the document are calculated. It is necessary to correct a reading level, which is a reference for determining the relationship, according to a change over time in the light source light amount or the like. For this reason, some document reading devices perform shading correction. This shading correction is a process in which a reference image having a predetermined density is read in advance by a reading sensor as correction data, and the density of image data read from a document image is corrected based on the correction data.

As an example, as shown in FIGS. 5A and 5B, a transparent contact glass 51, a light source 52, a light guide means (lens) 53, and a photoelectric conversion element 54 arranged in an array form. In the image forming apparatus using the contact type image sensor 50, a platen roller 55 or a guide plate 56 for conveying the document D onto the contact glass 51 is provided with the contact type image sensor 50 which is a reading sensor with the contact glass 51 interposed therebetween. opposite.

Therefore, in an image forming apparatus using such a contact image sensor 50, generally, the peripheral surface of the platen roller 55 or the lower surface of the guide plate 56 which is whitened is read by the contact image sensor 50 as a reference image. The shading correction is performed on the image data read in the subsequent document reading process using the light receiving signal at this time as correction data.

[0005]

However, the peripheral surface of the platen roller and the lower surface of the guide plate are liable to be soiled because they come into contact with the original conveyed on the contact glass, and the peripheral surface of the platen roller and the lower surface of the guide plate. If the image is contaminated, the correction data cannot be read properly using this as a reference density, and accurate shading correction cannot be performed. Therefore, there is a problem that the reading accuracy of the document image is reduced.

Further, in the case of a device having a guide plate, it is necessary to provide a predetermined gap between the guide plate and the contact glass in consideration of the document transportability. There is a difference between the position of the lower surface and the position of the original image surface on the contact glass, and the amount of light incident on the sensor does not match between the time of reading the shading correction data and the time of reading the original image. Accuracy decreases.

[0007] For this reason, Japanese Patent Application Laid-Open No. 2-37869 discloses a hard platen roller whose surface is surface-treated to a white color, and which is movable in a direction in which the platen roller comes into contact with or separates from a contact image sensor. Although the configuration provided is disclosed, even if the peripheral surface is surface-treated to a white color, contamination of the peripheral surface due to contact with a document cannot be completely avoided, and incorrect shading correction is performed. Therefore, it is not possible to reliably prevent the reading accuracy of the document image from being lowered. In this configuration, a gap is provided between the platen roller and the contact image sensor when the platen roller is closest to the contact image sensor. Also, it is not possible to eliminate a decrease in the reading accuracy of the original image due to the mismatch of the amounts of light incident on the sensor in the above.

SUMMARY OF THE INVENTION It is an object of the present invention to reliably prevent a reference image used for reading shading correction data from being stained by contact with a document and to change the reading state of the reference image when reading shading correction data. An object of the present invention is to provide a document reading apparatus that can always accurately perform shading correction by maintaining the same reading state as that of a normal document image, and maintain high reading accuracy.

[0009]

The present invention has the following arrangement to solve the above-mentioned problems.

(1) In a document reading apparatus for reading an image of a document passing between a reading sensor unit and a document pressing member,
A reference member moving mechanism for selectively moving the reference member between an exposure position and a retreat position between the reading sensor unit and the document pressing member, and a reference member moving mechanism via the reference member moving mechanism when reading shading correction data. And control means for moving the retracted position to the exposed position and reading the reference member.

In this configuration, the reference member for correcting the reading level is exposed between the reading sensor section and the document pressing member when reading the shading correction data.
When reading a document, the document is retracted from between the reading sensor unit and the document pressing member. Therefore, the reading sensor unit reads the reference member when reading the shading correction data,
When reading the document, the reference member is not stained by contact with the document.

(2) The reference member moving mechanism includes a winding roller having one end fixed to a peripheral surface of a sheet-like reference member and rotatably supported in both forward and reverse directions. When the reading is started, the take-up roller is rotated forward to feed the reference member to the exposed position, and after the reading of the shading correction data is completed, the take-up roller is rotated reversely to take up the reference member.

In this configuration, the reference member is fed out between the reading sensor unit and the document pressing member by the take-up roller that rotates forward when reading the shading correction data,
When the shading correction data is not read, it is taken up by a take-up roller that rotates in the reverse direction and stored at the retracted position. Therefore, the reading sensor unit reads the reference member when reading the shading correction data, and the reference member does not become dirty due to contact with the document when reading the document. Further, the reference member is easily and smoothly moved between the exposure position and the retracted position by the forward or reverse rotation of the winding roller.

(3) In the configuration of (2), the reference member moving mechanism may include an attachment portion for detachably fixing one end of a sheet-like reference member to a peripheral surface of a take-up roller.

According to this configuration, since one end of the reference member is detachable at the mounting portion on the peripheral surface of the winding roller, it can be easily replaced with a new reference member when the reference member is soiled or damaged. it can.

(4) In the configuration of (3), the winding roller may wind a sheet-like reference member around the peripheral surface within a range not overlapping with the mounting portion.

According to this configuration, since the reference member does not contact the mounting portion on the peripheral surface of the winding roller, even if the mounting portion protrudes from the peripheral surface of the winding roller, the reference member contacts the mounting portion. Therefore, the reference member is not damaged.

(5) The reference member moving mechanism includes a rotation transmitting mechanism for transmitting the rotation of the document pressing member, which is a rotating body, in the document conveying direction to the winding roller in the reverse direction.

In this configuration, when the document holding member, which is a rotating body, is rotated in the document conveying direction, the take-up roller rotates in the reverse direction. Therefore, at the start of reading the document image after the reading of the shading correction data, the document is conveyed between the reading sensor unit and the document pressing member, and at the same time, the reference member is taken up from the exposed position to the retracted position by the take-up roller. In addition, it is not necessary to provide separate driving sources for the document pressing member and the take-up roller.

(6) In the configuration of (5), the reference member moving mechanism includes a first pulley attached to the rotating shaft of the document pressing member, a second pulley attached to the take-up roller, and a first pulley. Between the first pulley and the second pulley based on the outer diameter ratio of the document pressing member and the take-up roller. May be set.

According to this configuration, the structure for moving the reference member by rotating the take-up roller in accordance with the state of conveyance of the document by the rotation of the document pressing member by the rotation force supplied from a single driving source is simplified. Can be

(7) The take-up roller is disposed downstream of the document pressing member in the document conveying direction.

In this configuration, the take-up roller is disposed downstream of the document pressing member in the document conveying direction. Therefore, at the start of reading of the document image after the reading of the shading correction data is completed, the direction in which the reference member is wound from the exposure position between the reading sensor unit and the document pressing member to the retracted position is a document holding member that is a rotating body. No extra load acts on the reference member from the document pressing member.

(8) The reference member moving mechanism includes a clutch for selectively disconnecting or connecting a part of the rotation transmitting mechanism, and the control means causes the clutch to perform a disconnecting operation during reading of the document image. .

In this configuration, a part of the rotation transmitting mechanism for transmitting the rotation of the document pressing member to the take-up roller in the reference member moving mechanism is cut during reading of the document image. Therefore, during the reading of the document image, the rotation of the document pressing member is not transmitted to the take-up roller, and the take-up roller that has taken up the reference member on the peripheral surface does not rotate. Will not occur.

(9) The reference member moving mechanism includes detection means for detecting the other end of the sheet-like reference member at the retracted position, and the control means controls the rotation of the winding roller based on the detection result of the detection means. It is characterized by controlling.

In this configuration, the other end of the reference member located at the retracted position is detected by the detecting means while one end is fixed to the peripheral surface of the winding roller, and the winding is performed based on the detection result of the detecting means. The rotation operation of the roller is controlled. Therefore, the timing for stopping the rotation of the winding roller when the reference member is moved from the exposure position to the retracted position is accurately determined based on the detection result of the detection means, and the reference member due to excessive rotation of the winding roller is determined. And the surrounding parts are prevented from being damaged.

(10) The reference member moving mechanism includes a guide member for guiding the other end of the reference member between the reading sensor unit and the document pressing member. A document guide for guiding the document is provided on the downstream side of the document.

In this configuration, the other end of the reference member is guided between the reading sensor unit and the document pressing member by the guide member, and the document is guided downstream by the document guide in the document conveying direction. Therefore, the reference member smoothly moves between the exposed position and the retracted position between the reading sensor unit and the document pressing member, and the document passes between the reading sensor unit and the document pressing member and moves in the document conveying direction. Is reliably guided to the downstream side.

In the constitutions (11) and (10), the document guide can be constituted by a flexible sheet material having a lower elasticity than the reference member.

According to this configuration, the reference member is moved from the retracted position to the exposed position while being in contact with the document guide.
In addition, the document can be smoothly transported to the downstream side in the document transport direction.

[0032]

FIG. 1 is a diagram showing a state when a document image is read by a document reading apparatus 1 according to an embodiment of the present invention, and FIG. 2 is a diagram showing a state when reading shading correction data. FIG. The original reading apparatus 1 includes a contact glass 21, a light source 22, a lens 23, and a reading sensor 24.
, A platen roller 3 having a part of the peripheral surface in contact with the upper surface of the contact glass 21 at the document reading position P, and a winding disposed downstream of the platen roller 3 in the document conveying direction in the direction of arrow A. One end is fixed to the take-up roller 4 and a peripheral surface of the take-up roller 4 via a screw 10 (corresponding to an attachment portion of the present invention), and has flexibility so that the take-up roller 4 can be wound around the take-up roller 4. White reference sheet 5 and guide member 6 for guiding the other end of reference sheet 5 to document reading position P
A flexible sheet 7 attached to the end of the guide member 6 on the document reading position P side to guide the document D to the downstream side in the document conveying direction; and a reference sheet near the end of the guide member 6 on the document reading position P side. Photosensor 11 for detecting the other end of 5
And

The platen roller 3, which is a document pressing member according to the present invention, comprises a mandrel and an elastic member such as rubber.
It is rotatably supported via a bearing (not shown). Further, the platen roller 3 is vertically movable with respect to the contact glass 21, and uniformly presses the original 50 and the white reference sheet 18 against the contact glass 21 by using its own weight.

The take-up roller 4 winds a reference sheet 5 sandwiched between the sensor unit 2 and the platen roller 3 around the peripheral surface. One end of the reference sheet 5 is fixed to a part of the peripheral surface of the winding roller 4 via a screw 10, and the other end is a free end. The reference sheet 5 is configured so as not to overlap with the screw 10 in a state where the reference sheet 5 is wound by the winding roller 4. In the present embodiment, the reference sheet 5 is fixed using the screws 10, but one end of the reference sheet 5 may be fixed to the winding roller 4 with a double-sided tape or the like. However, in consideration of the workability at the time of replacing the reference sheet 5, it is preferable to fix the reference sheet 5 using the screws 10.

The retracted position, which is the home position of the reference sheet 5 as the reference member of the present invention, is
Is changed to a state where the signal of the reference sheet 5 does not detect the other end of the reference sheet 5, or a position moved in any direction by a predetermined number of steps after the change. The photo sensor 11 is a reflection type photo sensor, and detects the other end of the reference sheet 5 located at the retreat position by detecting a difference in the amount of reflected light between the reference sheet 5 and the guide member 6.

The guide member 6 is made of sheet metal or resin. When a sheet metal is used, the reference sheet 5 and the original D are formed by bending one end to form an inclined portion.
To guide the reference sheet 5 so as not to damage the reference sheet 5 at the tip end of the guide member 6 when guiding the reference sheet 5. The guide member 6 made of resin guides the reference sheet 5 and the document D by providing an inclined portion at the tip. The flexible sheet 7 to be attached to the inclined portion of the guide member 6 is made of a sheet material which is weaker than the reference sheet 5, for example, a polyester film having a thickness of 80 to 100 μm.

The original reading apparatus 1 includes a stepping motor 8 which is a driving source for supplying the platen roller 3 with rotation in the directions of arrows B and C, a first pulley 9 a fixed to a rotation shaft of the platen roller 3, A second pulley 9b fixed to the rotating shaft of the winding roller 4 via a clutch 9c; and a rotation transmission mechanism 9 including a belt 9d stretched between the pulley 9a and the pulley 9b. . The rotation transmission mechanism 9 constitutes the reference member moving mechanism of the present invention together with the winding roller 4 and the stepping motor 8, and rotates the winding roller 4 in the same direction as the platen roller 3 while the clutch 9c is connected. Let it.

When reading the original image shown in FIG. 1, the clutch 9c is disengaged, during which only the platen roller 3 rotates in the direction of arrow B, and the winding roller 4 does not rotate. At the time of reading the shading correction data shown in FIG. 2, the clutch 9c is connected, and during this time, the winding roller 4 and the platen roller 3
And C direction.

In this embodiment, the clutch 9c is provided on the rotating shaft of the winding roller 4, and the winding roller 4 and the pulley 9b
The connection / disconnection of rotation is performed between the pulley 9a and the rotation shaft of the platen roller 3, and the connection / disconnection of rotation between the pulley 9a and the rotation shaft of the platen roller 3 is provided.
Cutting may be performed.

The operation of the clutch 9c is controlled by the control unit 31 together with the stepping motor 8. Control unit 3
1 outputs a signal for controlling the rotation of the platen roller 3 to the stepping motor 8 based on the detection result of the photo sensor 11 for detecting the free end (the other end) of the reference sheet 5, so that the winding roller 4 and the pulley 9 b A signal for controlling the connection / disconnection state is output to the clutch 9c. Thus, the rotation of the platen roller 3 and the take-up roller 4 is controlled.

In the sensor section 2, the light source 22 uses a tubular cathode ray lamp (xenon lamp) as an example, but an LED array can also be used. The lens 23 as a light guide means uses a selfoc lens array as an example, and guides reflected light from the document D to a reading sensor 24 which is an array of photoelectric conversion elements to form a document image. An optical fiber or the like can be used for the lens 23. The sensor unit 2 supplies a reading signal of the document image of the reading sensor 24 to the image processing unit 40.

The image processing section 40 converts a read signal output from the read sensor 24 into image data which is digital data, performs predetermined image processing, and outputs the image data to an image forming apparatus (not shown). For this reason, the image processing unit 40 includes a shading correction circuit 41 that corrects the density level of the image data, an MTF correction unit 42 that corrects the change in the signal of each pixel so as to have a sharp edge, and A gamma correction unit 43 is provided for correcting the visibility by performing correction.

FIGS. 3 and 4 are flowcharts showing the processing procedure of the control section of the document reading apparatus. The control unit 31
When the document reading key of the operation section 2 is operated (101), the stepping motor 8 is rotated forward so that the platen roller 3 rotates in the direction of arrow C (102), and the clutch 9c is connected (103). . As a result, the take-up roller 4 starts rotating in the direction of arrow C together with the platen roller 3, and the reference sheet 5 wound by the take-up roller 4 is moved along the guide member 6 into contact with the platen roller 3 and the contact glass 21. Are fed out toward the original reading position P.

At this time, the control unit 31
1 counts the amount of rotation of the stepping motor 8 from the timing when the open end of the reference sheet 5 is detected (104, 10).
5) After the stepping motor 8 rotates by the predetermined number of steps Sa, the stepping motor 8 is stopped (1).
06,107). The number of steps Sa counted by the control unit 31 is the rotation amount of the stepping motor 8 required until the reference sheet 5 completely passes the document reading position P after the open end of the reference sheet 5 faces the photosensor 11. Thereby, as shown in FIG. 2, the reference sheet 5 stops in a state where the intermediate portion is located at the exposure position with respect to the document reading position P.

The controller 31 turns on the light source 22 from this state (108), reads correction data (shading correction data) used for shading correction from the image on the reference sheet 5, and sends the read correction data to the shading correction circuit 41. It is stored (109). The light source 22
If it takes time to stabilize the light amount, the light source 22 should be turned on before the reference sheet 5 reaches the exposure position with respect to the document reading position P.

When the reading of the correction data is completed, the control section 31 determines whether or not to continue the original reading process (110). When the document reading process is not performed, the control unit 31 turns off the light source 22 (111), and then reversely rotates the stepping motor 8 so that the platen roller 3 rotates in the direction of arrow B (112). Thereby, the take-up roller 4 rotates in the arrow B direction together with the platen roller 3, and
The reference sheet 5 is taken up by the take-up roller 4.

The controller 31 waits for the stepping motor 8 to rotate by a predetermined number of steps Sb from the timing when the photo sensor 11 detects the open end of the reference sheet 5 (113 to 115). After rotating by the number of steps Sb, the clutch 9c is disconnected and the stepping motor 8 is stopped (1).
16, 117). Number of steps Sb counted by control unit 31
After the open end of the reference sheet 5 reaches the position facing the photosensor 11, the reference sheet 5 completely passes through this position, and is required to rotate the winding roller 4 to a range where the screw 10 does not contact the reference sheet 5. Number of steps. by this,
The reference sheet 5 stops at the retracted position shown in FIG.

When the original image reading process is to be executed after the correction data is stored in the shading correction circuit 41, the control unit 31 keeps the light source 22 on and the clutch 9c connected. The stepping motor 8 is reversed (121). As a result, the take-up roller 4 rotates in the arrow B direction together with the platen roller 3, and the reference sheet 5 exposed at the document reading position P is taken up by the take-up roller 4. The document D conveyed in the direction of the arrow A is moved by the platen roller 3 in the direction indicated by the arrow A after the front end reaches the document reading position P.
Transported downstream in the direction.

The controller 31 waits for the stepping motor 8 to rotate by a predetermined number of steps Sb from the timing when the photo sensor 11 detects the open end of the reference sheet 5 (122 to 124). After the rotation by the number of steps Sb, the clutch 9c is disconnected (125). Number of steps Sb counted by control unit 31
After the open end of the reference sheet 5 reaches the position facing the photosensor 11, the reference sheet 5 completely passes through this position, and is required to rotate the winding roller 4 to a range where the screw 10 does not contact the reference sheet 5. Number of steps. by this,
The take-up roller 4 stops rotating, and the reference sheet 5 stops at the retracted position shown in FIG.

On the other hand, since the stepping motor 8 continues to rotate in the reverse direction, the platen roller 3 continues to rotate in the direction of the arrow B, and the control unit 31 reads the image of the document D passing through the document reading position P by the reading sensor. (126), and converts the read signal output from the read sensor 24 into image data, and then converts the read signal into image data.
In step (127), shading correction is performed. In the shading correction processing, the correction data stored in the above processing 109 is used. Thereafter, the control unit 31
Is M in the MTF correction circuit 42 for the image data.
The TF correction processing and the γ correction processing in the γ correction circuit 43 are performed (128), and the image data after the predetermined image processing is output to the outside (129).

The control section 31 performs a document image reading process, a shading correction process, an MTF correction process, a γ correction process, and an image data output process.
(130 → 126). As a result, image data obtained by performing predetermined image processing on the entire image surface of the document D is output. When the rear end of the document D passes the document reading position P, the control unit 31
Is turned off, the stepping motor 8 is stopped, and the process is terminated (131, 132).

When only the reading process of the original image is performed without performing the reading process of the shading correction data, the control unit 31 first determines whether or not the photo sensor 11 detects the reference sheet 5. I do. Photo sensor 1
1 does not detect the reference sheet 5 and if the reference sheet 5 is located at the retracted position, the control unit 31
2 with the clutch 9c disconnected,
The steps 125 to 132 are executed by rotating the stepping motor 8 in the reverse direction and rotating the platen roller 3 in the direction of arrow B. On the other hand, when the operation of the document reading apparatus 1 is stopped while the reference sheet 5 is in the exposed position,
When the photo sensor 11 detects the reference sheet 5 at the start of the document reading process, for example, when the reference sheet 5 is pulled out during the standby time, the control unit 31
2 are turned on and the processes of 121 to 132 are executed with the clutch 9c connected.

[0053]

According to the present invention, the following effects can be obtained.

(1) The reference member for correcting the reading level is exposed between the reading sensor unit and the document pressing member when reading shading correction data, and is exposed between the reading sensor unit and the document pressing member when reading a document. When reading the shading correction data, the reading sensor unit can read the reference member in the same state as when reading the document image when reading the shading correction data. Can be prevented.
Thus, shading correction can always be performed accurately based on the shading correction data appropriately read from the reference member.

(2) The reference member is fed out between the reading sensor unit and the document pressing member by a take-up roller that rotates forward when reading shading correction data, and reversely rotates except when reading shading correction data. By winding the roller around the take-up roller and storing it in the retracted position, the reference member can be easily and smoothly moved between the exposed position and the retracted position by the forward or reverse rotation of the take-up roller.

(3) By rotating the document holding member, which is a rotator, in the document conveying direction, the take-up roller is rotated in the reverse direction. When the reading of the document image after the completion of the reading of the shading correction data is started, The document can be conveyed between the reading sensor unit and the document pressing member, and at the same time, the reference member can be taken up from the exposed position to the retracted position by the take-up roller. It is not necessary, and the size and cost of the device can be reduced.

(4) By arranging the take-up roller on the downstream side of the document pressing member in the document conveying direction, the reading of the reference member and the document can be started at the start of reading the document image after the completion of reading the shading correction data. The direction of winding from the exposure position to the retracting position with the pressing member can be made to coincide with the rotation direction of the document pressing direction of the document pressing member, so that no extra load acts on the reference member from the document pressing member. Thus, it is possible to prevent the reference member from being damaged.

(5) A part of the rotation transmitting mechanism for transmitting the rotation of the document pressing member to the take-up roller in the reference member moving mechanism is cut during reading of the document image, so that the document pressing is performed during reading of the document image. It is possible to prevent the rotation of the member from being transmitted to the take-up roller, to prevent the take-up roller having taken up the reference member on the peripheral surface from further rotating, and to prevent damage to the reference member and the peripheral portion. it can.

(6) The other end of the reference member located at the retracted position is detected by the detecting means with one end fixed to the peripheral surface of the winding roller, and the winding roller is detected based on the detection result of the detecting means. By controlling the rotation of the winding member, the timing for stopping the rotation of the winding roller when the reference member is moved from the exposed position to the retracted position can be accurately determined based on the detection result of the detecting means, and It is possible to prevent the reference member and the peripheral portion from being damaged due to excessive rotation of the roller.

(7) The other end of the reference member is guided between the reading sensor portion and the document pressing member by the guide member, and the document is guided to the downstream side in the document conveying direction by the document guide. The document can be smoothly moved between the exposure position and the retreat position with respect to the portion between the document and the document holding member, and the document passes between the reading sensor portion and the document holding member to the downstream side in the document conveying direction. It can be surely guided.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a state when a document image is read by a document reading apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a state of the document reading apparatus when reading shading correction data.

FIG. 3 is a flowchart showing a processing procedure at the time of reading shading correction data in a control unit of the document reading apparatus.

FIG. 4 is a flowchart showing a processing procedure when reading a document image in a control unit of the document reading apparatus.

FIG. 5 is a diagram showing a configuration of a main part of a conventional document reading apparatus.

[Explanation of symbols]

 1-Document Scanning Device 2-Sensor Unit 3-Platen Roller 4-Winding Roller 5-Reference Sheet 8-Stepping Motor 9-Rotation Transmission Mechanism 9c-Clutch 10-Screw (Mounting Part) 11-Photo Sensor 21-Contact Glass D -Original P-Original reading position

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kyosuke Taka 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside (72) Inventor Hidekazu Sakagami 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside (72) Inventor Mitsuharu Yoshimoto 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Shoichi Fukudome 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Sharp Corporation F term (reference) 5B047 AA01 BA01 BB02 BC20 CA30 DA04 DC06 5C072 AA01 BA04 BA08 DA25 EA05 FB12 LA07 RA16 UA02 XA01

Claims (7)

[Claims] An original reading apparatus for reading an image of an original passing between a reading sensor and an original pressing member, wherein a reference member is selected between an exposure position and a retracted position between the reading sensor and the original pressing member. A reference member moving mechanism that moves the reference member from the retracted position to the exposed position via the reference member moving mechanism when reading the shading correction data, and a control unit that reads the reference member. An original reading apparatus, comprising: 2. The reference member moving mechanism includes a take-up roller fixed to one end of a sheet-like reference member on a peripheral surface and rotatably supported in both forward and reverse directions. 2. The reference member according to claim 1, wherein, at the start of reading, the take-up roller is rotated forward to feed the reference member to the exposed position, and after the reading of the shading correction data is completed, the take-up roller is reversed to take up the reference member. Original reading device. 3. The reference member moving mechanism according to claim 2, wherein said reference member moving mechanism includes a rotation transmitting mechanism for transmitting a rotation of a document pressing member, which is a rotating body, in a document conveying direction to a take-up roller in a reverse direction. Original reading device. 4. The document reading apparatus according to claim 3, wherein the take-up roller is disposed downstream of the document pressing member in the document conveying direction. 5. The apparatus according to claim 1, wherein said reference member moving mechanism includes a clutch for selectively disconnecting or connecting a part of a rotation transmitting mechanism, and said control means performs a disconnecting operation of the clutch during reading of a document image. Item 5. The document reading device according to Item 3 or 4. 6. The reference member moving mechanism includes detection means for detecting the other end of the sheet-like reference member at the retracted position, and the control means controls the rotation of the winding roller based on a detection result of the detection means. 3. The document reading apparatus according to claim 2, wherein the reading is performed. 7. The reference member moving mechanism includes a guide member for guiding the other end of the reference member between the reading sensor unit and the document pressing member. 4. The document reading device according to claim 3, further comprising a document guide for guiding the document on a downstream side.