JP2003222957A - Image reader and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve image reading accuracy by stabilizing the behavior of an original when the original rushes in a pair of resist rollers 22 or when it is drawn out from a pair of ejection rollers 28. <P>SOLUTION: The image reader 50 is provided with a pair of resist rollers 22 carrying the original, a pair of ejection rollers 28 positioned on the downstream side of a pair of resist rollers 22 and carrying the original, and image reading parts 25 and 27 reading the image of the original at an image reading position between a pair of resist rollers 22 and a pair of ejection rollers 28, and reads the image of the original while carrying the original to the reading parts 25 and 27. The reader 50 is provided with cams 34 and 35 for switching the holding force of at least either the 1st or the 2nd carrying means and a control means for controlling the action of the cams 34 and 35. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus and an image forming apparatus having a conveying means for conveying a document.

[0002]

2. Description of the Related Art Conventionally, the following two methods are well known as methods for reading an image on a document which are adopted in an image reading apparatus.

First, the first method is to set an original on the original table by a predetermined method and scan the original fixed on the original table glass with a movable optical carriage to form an image on the original. This is a fixed original reading method in which the document is read at the reading site.

The second method is an original flow reading method in which an original is conveyed at a predetermined conveying speed and is read at a predetermined reading portion where a fixed optical carriage unit is arranged.

In the latter original flow reading method, the optical carriage can be fixed as compared with the former fixed original reading method, and it is not necessary to reciprocate the optical carriage every time. Therefore, the apparatus configuration is not complicated, and it is superior to the former fixed document reading method in that the processing speed is increased.
Further, in a copying machine or the like, with the recent progress of digital processing technology, even if a plurality of copies are formed from the same original, it is only necessary to read the original once.
That is, by temporarily storing the image information once read as digital information in a storage medium such as a computer,
This makes it easy to re-create the required number of copy images based on the stored image information. Also in this respect, the advantage of the image reading by the flow reading method is further increased.

If the original includes images on its front and back sides,
From the viewpoint of convenience of operation and speedup when reading images on both sides of the document, along the document conveyance path,
There is also a reading device which is provided with two optical carriages and is configured to read an image included in each surface of a document by each optical carriage. According to such a device configuration,
Since images included on the front and back of a document conveyed along a predetermined path can be read and read almost simultaneously,
The reading process in double-sided copying of a document can be speeded up.

[0007]

However, in the image scanning apparatus of the original flow scanning method as described above, the disturbance of the behavior of the original document during reading adversely affects the reading accuracy. For example, the read image may expand or contract, or the image may suddenly be disturbed due to a change in the document conveying speed during reading or vertical movement in the conveying path.

Further, in the case of a color scanner, the reading elements for each color lined up in the document transport direction are read for each color at a timing that matches the document transport speed, and are electrically superimposed to form a color image again. Therefore, the disturbance in the behavior of the document that occurs during conveyance appears as a color shift in the read image. In particular, when the leading edge of the document enters the transport roller as the transport unit or the trailing edge of the document exits the transport roller, the behavior of the document is disturbed,
There is a problem that the speed of the document with respect to the reading portion is disturbed, and the image is disturbed and the color is misregistered.

Therefore, in order to solve the above problems, it is an object of the present invention to stabilize the behavior of a document when the document enters or exits the conveying means and improves the image reading accuracy.

[0010]

In order to achieve the above object, a typical structure of the present invention is a first conveying means for conveying an original, and an original located downstream of the first conveying means for conveying the original. And a reading section for reading an image of the document at an image reading position between the first and second conveying sections, and the document is conveyed to the reading section. In the image reading device for reading the image of the document, the image reading apparatus includes a switching unit that switches a clamping force of at least one of the first and second conveying units, and a control unit that controls an operation of the switching unit. Characterize.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) The first embodiment of the present invention will be described with reference to the drawings. In the description of the first embodiment, the schematic configuration of the image forming apparatus will be first described, and then the image reading apparatus will be described in detail. FIG. 6 is a schematic configuration diagram of the image forming apparatus of the present invention.

<Image Forming Apparatus> As shown in FIG. 6, the image forming apparatus includes an image reading unit 50A for reading an image of an original,
The image forming means 50B forms an image on the transfer material based on the read image information. Further, in the image forming apparatus, control of conveyance of a document, reading of an image on the document, formation of an image, and the like is performed by a control unit (not shown).

When the image forming start signal is input to the image forming means 50B, the photosensitive drum 51 as an image carrier is charged by the charging means 53 so as to have a predetermined potential. On the other hand, an image reading device as an image reading unit 50A described later acquires image information from a document and uses the image information as image forming unit 50A.
Communicate to B.

In the image forming means 50B, an exposing means such as an LED which emits ON / OFF light upon receiving the image information.
An electrostatic latent image corresponding to the original image is formed on the surface of the photosensitive drum 51 by 52. Next, this electrostatic latent image is developed by a developing device 54 as a developing means containing toner particles, and a toner image is obtained on the photosensitive drum 51. The toner image formed on the photosensitive drum 51 is electrostatically transferred onto the transfer material by the transfer unit 57. After that, the transfer material is electrostatically separated and fixed by the fixing device 56.
Then, the image is output after being fixed by heat.

On the other hand, on the surface of the photosensitive drum 51 after the toner image transfer, a cleaner 55 removes adhered contaminants such as transfer residual toner, and if necessary, an optical memory (ghost) for image exposure.
Is repeatedly used for image formation by being exposed by the pre-exposure means 58 for removing the.

<Outline of Image Reading Apparatus> FIG. 1 is a side sectional view showing a structure of the image reading apparatus, and FIG. 2 is an enlarged side sectional view showing a document feeding portion of the image reading apparatus of the first embodiment.
As shown in the figure, the image reading device as the image reading means 50A includes a flatbed image reading unit (FB unit) 1 for placing and fixing a document and reading a surface image thereof, and an automatic device mounted on the upper surface of the FB unit 1. The feeding section (ADF section) 2 is provided, and a part of the FB section 1 and a part of the ADF section 2 are combined to form a flow reading section.

The FB section 1 is a mechanism for reading a front surface image of a document which is placed and fixed, and is provided with a reference document table glass 3 which is a translucent plate material on which the document is placed, and the document. A first optical carriage A for reading a document is provided below the base glass.

The first optical carriage A is connected to an endless drive belt 5, and this drive belt 5 is further connected to a drive motor 6. The power of the drive motor 6 is transmitted to the first optical carriage A via the drive belt 5, so that the first optical carriage A can move in parallel with the platen glass 3. The first optical carriage has a function of reading an image on a document placed and fixed on the platen glass and a function of reading an image on a document being conveyed by keeping it at a fixed position (a flow reading function). Have both.

The lamp 7 arranged on the upper surface of the first optical carriage A is a light source for irradiating the original with light.
The reflected light reflected from the document is reflected by the reflection mirror 8 and the condenser lens.
It is guided to the CCD 9 by 10 and. The CCD 9 is a well-known photoelectric conversion element that converts incident light into an electric signal.
Further, a document abutting reference plate 11 is provided on the document table glass 3.

On the other hand, the ADF unit 2 is provided with a document stacking tray 13 for mounting and stacking documents on the upper part thereof. The documents on the document stack tray 13 are regulated by the document side regulation plates 12 on both sides in the carrying (feeding) direction. Further, the known document presence / absence sensor 15 recognizes the presence of the document by detecting the leading edge of the document by the lever mountain. Further, the well-known document length detection lever 14 detects the length of the document. Further, a weight 16 for pressing the leading edge of the original sent from the original stack tray 13 from above and an original shutter 17 for preventing the leading edge of the original from entering the separating / feeding unit are provided.

The pickup roller 18 has a function of sequentially feeding the stacked original document from the lowest one. The document fed out by the pickup roller 18 is conveyed to the flow reading section by the downstream feeding roller 20.
Further, the separation belt 19 provided at a position facing the feeding roller 20 with the original feeding path sandwiched therebetween is rotationally driven in a direction opposite to the rotation direction of the feeding roller 20 to reliably feed the originals one by one. Separate the overlapped documents so that

The pre-registration sensor lever 21 detects the leading edge of the document and measures the timing of loop formation of the document. The pair of registration rollers 22 as the first conveying means sends out the conveyed original document to the reading section at a predetermined timing. The document leading edge detection lever 23 detects the leading edge of the document fed by the registration roller pair 22. The document transport upper guide 24, which is a guide unit, is provided so as to face the document table glass 3 and guides the document to the first reading portion 25. The first reading portion 25 is a predetermined gap provided between the document table glass 3 and the document transport upper guide 24.

The image included on the front surface (first surface) of the document is read by the optical carriage A that remains in the fixed position when the document passes through the first reading portion 25. Here, the pickup roller 18, the feeding roller 20,
The registration roller pair 22 is driven by one motor (not shown). That is, the pickup roller 18 and the feeding roller 20 are driven by the normal rotation operation of the motor. At this time, the registration roller pair 22 is not rotating due to the one-way clutch. The registration roller pair 22 is rotated by the reverse rotation of the motor at a predetermined timing, and the document is sent to the reading portion.

The second of the second image reading means
The optical carriage B is provided in a position facing the first optical carriage A with the original platen glass 3 interposed therebetween in the ADF unit 2 which is a holding unit that holds the second optical carriage B. In the second optical carriage B, the same reflection mirror and CCD 9 as in the carriage A are arranged.

In this way, the second carriage B, which has substantially the same structure as the first carriage A, displays the image included in the other surface (second surface) of the document at the second reading portion 27. Read. The second reading portion 27 is set on the downstream side of the first reading portion 25 on the document conveyance path along the platen glass 3. Further, the second carriage B can rotate about the fulcrum 26 in the case of jamming an original.

The original after passing through the first and second reading portions 25 and 27 is a pair of discharge rollers 28 as a second conveying means.
Thus, the FB portion 1 is discharged to the outside of the machine. On the side surface of the FB unit 1, a discharge stack tray 29 for stacking the documents discharged by the discharge roller pair 28 is provided. The discharge roller pair 28 is driven by a motor (not shown) different from the registration roller driving motor described above. Therefore, the conveyance speeds of the registration roller pair 22 and the discharge roller pair 28 can be set arbitrarily.

As shown in FIG. 3, the registration roller pair 22 and the discharge roller pair 28 are held by holding members 30 and 31. FIG. 3 shows the registration roller pair 22 and the discharge roller pair 28.
3 is an explanatory diagram of a configuration of FIG. The pair of discharge rollers 28 and the pair of registration rollers 22 are biased by springs 32 and 33 in holding members 30 and 31, respectively, to obtain a pressure for pinching a document. The holding members 30 and 31 are moved up and down by cams 34 and 35 serving as switching means, respectively, to move between a conveyance position for nipping and conveying a document shown by a solid line and a separation position for separating a document shown by a broken line. Is possible. As a switching means for switching the holding member up and down, a solenoid may be used instead of the cam. The operation of the above configuration will be described below.

<Document Fixed Reading Method> When the image is read by the FB unit 1, the ADF 2 is opened, the document is placed on the document table glass 3, and the document position is abutted against the document abutting reference plate 11 to read the document. set. Next, by closing the ADF 2, the original is pressed and fixed to the original table glass 3 by the pressure plate 4. As a result, the curl of the original is corrected and the original is brought into close contact with the original table glass 3. afterwards,
When the operator presses a document reading start button provided on an operation panel (not shown), the reading of the document is started.

First, the drive belt 5 starts operating by the supply of power from the drive motor 6, and the carriage A moves to a predetermined initial position accordingly, and moves from the initial position to the image reading position at a predetermined speed. Accelerate until it reaches.
After reaching the predetermined speed, the carriage A reaches the leading end position of the document abutted against the document abutting reference plate 11 while maintaining that speed. After that, the carriage A moves while keeping a predetermined speed to read the original. After reading the entire surface of the original, the carriage A is reversed in the direction opposite to the reading direction by the reverse driving of the drive motor 6 and returns to the predetermined standby position.

<Document Flow Reading Method> Next, the case of the flow reading method will be described. In the case of the flow-reading, the document is loaded on the document loading tray 13 of the ADF 2. The ADF 2 can know that a document is placed on the document stacking tray 13 by a sensor attached to the document length detection lever 14 and a document presence / absence sensor 15. In addition, the operator can
By setting the width of the manuscript, the size of the manuscript can be known by a combination of detection with a sensor attached to the manuscript length detection lever 14. When the operator presses the original reading start button (not shown) in the above state,
The document shutter 17 that regulated the leading edge of the document is released,
The weight 16 and the feed pickup roller 18 convey the document bundle to the document separating portion.

Next, the originals are separated and fed one by one by the separating belt 19 and the feeding roller 20. At this time, the registration roller pair 22 is in the transport position shown by the solid line in FIG. 3, and the upper and lower rollers are in contact with each other. The leading edge of the document is 22 pairs of registration rollers.
When the pre-registration sensor lever 21 forms a predetermined loop, the rotation of the feeding roller 20 is stopped.
After a predetermined timing, the registration roller pair 22 starts rotating to convey the original.

The leading edge of the conveyed document is detected by the document leading edge detection lever 23 and determines the time for the document to reach the image reading position. The document is guided to the first reading portion 25 by the document transport upper guide 24. In the first reading portion 25, an image is sequentially read on one side of the document while the document is being transported at a predetermined transport speed. Also, the manuscript is second
The image is read on the other surface of the document in sequence by the reading section of the carriage B while being conveyed at a predetermined conveyance speed.

At this time, the discharge roller pair 28 is at the separated position shown by the broken line in FIG. 3, and the leading edge of the document is at the second reading portion 27.
After passing through, it enters the gap between the pair of upper and lower discharge rollers 28. After the leading edge of the original has passed the nip position of the discharge roller pair 28, the cam 34 rotates to hold the holding member.
30 and the discharge roller pair 28 move to the transport position shown by the solid line in FIG. As a result, the document is in a state of being conveyed by both the discharge roller pair 28 and the registration roller pair 22.

Next, before the trailing edge of the document comes out of the registration roller pair 22 from this state, the registration roller pair 22 is moved to the separated position shown by the broken line in FIG. 3 by the rotation of the cam 35. After that, the document is conveyed only by the discharge roller pair 28, and after all the images of the document are read, the document is discharged onto the discharge stack tray 29.

The registration roller pair 22 and the discharge roller pair 28
Are driven by different motors,
The transport speed of these roller pairs can be set arbitrarily. During the document conveyance, the conveyance speed of the discharge roller pair 28 is set to a predetermined speed higher than the conveyance speed of the registration roller pair 22. As a result, the document is conveyed while being pulled by the pair of discharge rollers 28, and it is possible to prevent deterioration of the conveyance accuracy due to the bending of the document.

Further, by controlling the respective motors, it is possible to arbitrarily change the conveyance speed of the registration roller pair 22 and the discharge roller pair 28 during the conveyance of the document. After the trailing edge of the document passes through the registration roller pair 22,
Only the discharge roller pair 28 that is transported at a speed faster than 22 is used to transport the document.However, because the transport speed is high, the document passes through the image reading position before the predetermined time, and the scanned image is The image of the original is read as a contracted image in the conveying direction of the original.

Therefore, when the original is conveyed only by the pair of discharge rollers 28, the conveying speed of the pair of discharge rollers 28 is decelerated with respect to the conveying speed of the pair of discharge rollers 28 until then, and the pair of registration rollers 22 collect the original. By carrying at the same carrying speed as the carrying speed, it is possible to reduce the adverse effect on the image reading magnification. The above is both carriages A,
9 is a series of operation modes related to double-sided reading of a document by B.

(Second Embodiment) A second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is an enlarged side cross-sectional view showing a document feeding section of the image reading apparatus of the second embodiment. The same components as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted.

Registration roller pair 22 and discharge roller pair 28
Is movably attached to the frame of the image reading apparatus, and holding members 36 and 37, a spring 38 as a second urging means and a spring 39 as a first urging means attached to the holding members. , Are urged by the opposing rollers.
The holding members 36 and 37 are moved up and down by the cams 40 and 41 as switching means, whereby the springs 38 and 39 change the urging force of the registration roller pair 22 and the discharge roller pair 28. That is, the position indicated by the solid line in FIG. 4 has a stronger biasing force than the position indicated by the broken line.

Until the original reaches the discharge roller pair 28, the registration roller pair 22 is in the position shown by the solid line in FIG. 4, and the original is conveyed by a predetermined urging pressure. At this time, in the discharge roller pair 28, the holding member 36 is at the position shown by the broken line, and the document is passed through the second reading portion 27, and then the leading end is nipped by the discharge roller pair 28. The leading edge of the document is 28
After passing through the nip position of 1, the holding member 36 moves to the position shown by the solid line (first urging position) by the rotation of the cam 40, and the urging pressure is increased to a predetermined value. Next, before the trailing edge of the document comes out of the registration roller pair 22, the holding member 37 moves to the position indicated by the broken line (second biasing position) by the rotation of the cam 41. After reading all the images of the document, the document is discharged onto the discharge stack tray 29.

Further, the conveyance speeds of the registration roller pair 22 and the discharge roller pair 28 may be changed in synchronization with the urging pressure of each roller by controlling each drive motor. By setting the conveyance speed to the optimum value with respect to the biasing pressure, it is possible to stabilize the conveyance accuracy of the document and improve the image reading accuracy.

(Third Embodiment) The third embodiment of the present invention will be described with reference to the drawings. FIG. 5 is an enlarged side cross-sectional view showing a document feeding section of the image reading apparatus of the third embodiment. The same components as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 5, a document guide portion 43 is formed on the upstream side of the first rotation holding member 42 of the registration roller pair 22, and the guide portion 43 projects to the document conveying surface. The rotation holding member 42 is fixed so as to be rotatable around a fulcrum 44, and when the leading end of the document enters the guide portion 43 on the upstream side of the rotation holding member 42, the rotation holding member 42 depends on the thickness of the document. Rotates,
An urging pressure of the document is applied to the registration roller pair 22. When the document passes through the guide portion 43, the rotation holding member 42 rotates, and the urging pressure of the registration roller pair 22 is released before the rear end of the document passes through the registration roller pair 22.

In the discharge roller pair 28, the second rotation holding member 45
A guide portion 46 and a fulcrum 47 having the same structure are provided downstream of, and the leading end of the document passes the nip position of the discharge roller pair 28 and the guide portion.
At the time point of approaching 46, the rotation holding member 45 rotates around the fulcrum 47, and biasing pressure is applied to the discharge roller pair 28. By forming the guide portion at a smooth angle with respect to the document transport path, it is possible to suppress a shock to the document when the guide portion rushes into the guide portion.

(Other Embodiments) In the above-described third embodiment, the rotation holding members 42 and 45 directly hold the registration roller pair 22 and the discharge roller pair 28, but the present invention is not limited to this. The springs 32, 33, 38, 39 shown in the embodiment or the second embodiment may be held.

Further, in the above-described embodiment, the copying machine is exemplified as the image forming apparatus, but the present invention is not limited to this, and the present invention can be applied to other image forming apparatuses such as a facsimile machine. .

[0047]

As described above, in the present invention, the switching means for switching the clamping force of at least one of the first and second conveying means, and the control means for controlling the operation of the switching means. Since the document has the feature, it is possible to stabilize the behavior of the document when the document rushes into the first transport unit and when the document comes out of the second transport unit, and it is possible to improve the image reading accuracy.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a structure of an image reading apparatus.

FIG. 2 is an enlarged side cross-sectional view showing a document feeding unit of the image reading apparatus according to the first embodiment.

FIG. 3 is an explanatory diagram of a configuration of a registration roller pair 22 and a discharge roller pair 28.

FIG. 4 is an enlarged side cross-sectional view showing a document feeding unit of the image reading apparatus of the second embodiment.

FIG. 5 is an enlarged side cross-sectional view showing a document feeding unit of the image reading apparatus of the third embodiment.

FIG. 6 is a schematic configuration diagram of an image forming apparatus of the present invention.

[Explanation of symbols]

A ... First optical carriage B: second optical carriage 1… FB section 2 ... ADF section 3 ... Reference platen glass 4 ... Pressure plate 5 ... Drive belt 6 ... Drive motor 7 ... Lamp 8 ... Reflective mirror 9 ... CCD 10… Condenser lens 11… Document reference plate 12… Original side plate 13… Original loading tray 14… Original length detection lever 15… Document presence sensor 16… Weight 17… Original shutter 18… Pickup roller 19… Separation belt 20… Feeding roller 21… Sensor lever before registration 22… Registration roller pair 23… Document edge detection lever 24… Document transport upper guide 25… First reading part 26… fulcrum 27… Second reading part 28… Ejection roller pair 29… Discharge stack tray 30 ... Holding member 31… Holding member 32… Spring 33 ... Spring 34 ... Cam 35 ... Cam 36 ... Holding member 37… Holding member 38… Spring 39… Spring 40 ... cam 41 ... Cam 42 ... Holding member 43… Guide section 44… Support point 45… Holding member 46… Guide section 47… fulcrum 50… Image reading device 50A ... Image reading means 50B ... Image forming means 51 ... Photosensitive drum 52 ... Exposure means 53 ... Charging means 54 ... Developer 55… Cleaner 56… Fixer 57… Transfer means 58… Pre-exposure means

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 1/04 H04N 1/12 Z F term (reference) 2H076 BA15 BA33 BA47 BA48 BA49 2H108 AA05 FA01 3F049 AA01 DA12 DA14 DA19 DB04 DB06 LA05 LA11 LB02 5C062 AA05 AB02 AB17 AB32 AB33 AC11 AC15 AD01 AD06 5C072 AA01 BA17 CA02 DA02 DA04 EA05 NA01 NA04 XA01

Claims (6)

[Claims] 1. A first transport means for transporting a document, and the first transport means.
A second transport unit located downstream of the transport unit for transporting the original document; and a reading portion for reading an image of the original document at an image reading position between the first transport unit and the second transport unit. In an image reading apparatus that reads an image of the original while conveying the original to a reading portion, a switching unit that switches a clamping force of at least one of the first and second conveying units, and an operation of the switching unit. An image reading apparatus comprising: a control unit that controls the image reading apparatus. 2. The image reading apparatus according to claim 1, wherein the first and second transporting units have a transporting position for sandwiching and transporting a document, and a separating position for releasing the sandwiching of the document, The control unit moves the first transport unit to the transport position and the second transport unit to the separated position when the document is transported by only the first transport unit before reaching the second transport unit. Then, after the leading edge of the document has passed the second transport means, the second transport means is moved to the transport position, and after the second transport means holds the document, the trailing edge of the document is transported by the first transport. An image reading apparatus, characterized in that the switching means is controlled so as to move the first conveying means to a separated position before passing through the means. 3. The image reading apparatus according to claim 1, wherein the first and second conveying means have first and second urging means, respectively, and these urging means hold the original document. A first biasing position for transporting the document by a small amount, and a second biasing position that exerts a biasing force smaller than the first biasing position on the document.
When the original is conveyed by only the first conveying means before reaching the second conveying means, the control means sets the first conveying means to the first urging position, 2 moving means is moved to a second urging position, the second conveying means is moved to a first urging position after the leading edge of the original has passed the second conveying means, and the second conveying means is the original. The first biasing position before the trailing edge of the document passes the first transporting means.
An image reading apparatus, characterized in that the switching means is controlled so as to move the conveying means to the second biasing position. 4. A first transport means for transporting a document, and the first transport means.
A second transport unit located downstream of the transport unit for transporting the original document; and a reading unit for reading an image of the original document at an image reading position between the first transport unit and the second transport unit. While carrying the original document to the reading portion,
An image reading apparatus for reading an image of an original includes first and second rotation holding members for holding the first and second conveying means, and the rotation holding member is rotatably fixed about a fulcrum. A guide portion is formed on the opposite side of the conveying means with respect to the fulcrum of the rotation holding member, and the guide portion protrudes on a document conveying surface, and when the document passes through the guide portion, An image reading apparatus, wherein a rotation holding member rotates around the fulcrum, and the position of the conveying unit moves. 5. A first transport means for transporting a document, and the first transport means.
A second transport unit located downstream of the transport unit for transporting the original document; and a reading unit for reading an image of the original document at an image reading position between the first transport unit and the second transport unit. While carrying the original document to the reading portion,
In an image reading apparatus for reading an image of the document, a first biasing position for gripping and transporting the document and a biasing position smaller than the first biasing position for each of the first and second transporting means. A first and a second biasing means having a second biasing position for exerting a biasing force on the original, and a first and a second rotation holding member for holding the first and second biasing means. The rotation holding member is rotatably fixed about a fulcrum, and a side opposite to the conveying means with respect to the fulcrum of the rotation holding member forms a guide portion, and the guide portion is on a document conveying surface. The image reading apparatus is characterized in that it is protruding, and when the document passes through the guide portion, the rotation holding member rotates around the fulcrum, and the position of the biasing unit moves. 6. An image forming apparatus comprising: an image reading unit; and an image forming unit that forms an image on a transfer material based on the image information acquired from the image reading unit. An image forming apparatus, which is the image reading apparatus according to claim 5.