JP2024011404A - Document reading device and image forming apparatus - Google Patents

Abstract

To prevent damage to a long-size document occurring when feeding it.SOLUTION: A document reading device comprises: a document placement tray; a first ejection tray and a second ejection tray; a first conveyance path that extends without being curved; a first reading unit; a second conveyance path that branches from the first conveyance path and extends while being curved; a switching unit that is provided at a branch point of the first conveyance path and switches a document conveyance direction; a conveying unit that conveys a document from the document placement tray to the first ejection tray through the first conveyance path or conveys the document from the document placement tray to the branch point through the first conveyance path, and conveys the document from the branch point to the second ejection tray through the second conveyance path; and a control unit that, when the length in the conveyance direction of the document is equal to or more than a predetermined length, causes the switching unit to switch the direction of conveying the document after the branch point to the first conveyance path, and when the length in the conveyance direction of the document is less than the predetermined length, causes the switching unit to switch the direction of conveying the document after the branch point to the second conveyance path.SELECTED DRAWING: Figure 4

Description

The present invention relates to a document reading device and an image forming device, and particularly to a technique for switching a conveyance path depending on the size of a document.

2. Description of the Related Art In a document reading device equipped with an automatic document feeder (ADF), a technique for switching the conveyance path depending on the type of document is known. For example, Patent Document 1 discloses that when sending a normal original, the original is ejected using a curved transport path, and when sending a small-sized hard original such as a business card or license, the original is ejected using an uncurved transport path. Discloses a technology for ejecting a document using a .

JP2011-86988A

By the way, if a long-sized original is sent using a curved conveyance path, there is a risk that the original will be damaged, such as the original being bent or pasted materials such as photographs coming off. The technique disclosed in Patent Document 1 is intended for transporting small-sized hard documents, and therefore cannot solve this problem.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to prevent damage to a document that occurs when sending a long-sized document.

A document reading device according to an aspect of the present invention includes a document placement tray on which a document is placed, a first ejection tray and a second ejection tray from which the document is ejected, and an ejection tray from the document placement tray to the first ejection tray. a first conveyance path that extends without curving; a first reading section that is provided on the first conveyance path and reads an image on one side of the document; and a first conveyance path that is located downstream of the first reading section in the document conveyance direction. a second conveyance path that branches off from the main body and extends in a curved manner toward the second ejection tray; and a second conveyance path that is provided at the branching point and switches the document conveyance direction beyond the branching point to the first conveyance path or the second conveyance path. When the document transport direction is switched to the first transport path by the switching unit and the switching unit, the original is transported from the document placement tray to the first output tray through the first transport path, and the original is transported by the switching unit. When the direction is switched to the second conveyance path, the document is conveyed from the document placement tray to the branch point through the first conveyance path, and from the branch point to the second output tray through the second conveyance path. When the length of the transport unit and the original in the transport direction is equal to or greater than a predetermined length, the switching unit sets the original transport direction beyond the branching point as the first transport path. A control unit is provided that causes the switching unit to cause the document transport direction beyond the branch point to be the second transport path when the length is less than a predetermined length.

An image forming apparatus according to another aspect of the present invention includes the document reading device described above and an image forming section that forms an image read by the document reading device on a recording medium.

According to the present invention, if the length of the document in the conveyance direction is equal to or greater than a predetermined length, the document is conveyed through the uncurved first conveyance path and is ejected to the first output tray. , it is possible to prevent damage to the original that occurs when sending a long-sized original.

1 is a front sectional view showing the structure of an image forming apparatus. FIG. 1 is a block diagram showing the configuration of an image forming apparatus. FIG. 3 is a cross-sectional view showing the configuration of a document transport section and an image reading section. It is a flowchart which shows conveyance direction change processing. FIG. 3 is a diagram illustrating a situation when a document is being fed diagonally.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A document reading device and an image forming device according to an embodiment of the present invention will be described below with reference to the drawings.

[Configuration of image forming apparatus 1]
FIG. 1 is a front sectional view showing the structure of an image forming apparatus 1 including a document reading device 5 according to an embodiment of the present invention. FIG. 2 is a block diagram showing the internal configuration of the image forming apparatus 1. As shown in FIG.

As shown in FIGS. 1 and 2, the image forming apparatus 1 is a multifunction device having multiple functions such as a copy function, a transmission function, a printer function, and a facsimile function. The casing of the image forming apparatus 1 houses an image reading section 11, an image forming section 12, a fixing section 13, a paper feeding section 14, a conveyance section 17, and the like. A display section 15 and an operation section 16 are provided on the front of the housing.

The document transport unit 6 transports the document placed on the document tray 24. The image reading section 11 reads a document image using a document moving method that optically reads the document transported by the document transport section 6 or a document fixing method that optically reads the document placed on the contact glass 52. Generate the image data shown. Details of the configurations of the image reading section 11 and the document transport section 6 will be described later.

The image forming section 12 includes a photosensitive drum, a charging device, an exposure device, a developing device, and a transfer device. The image forming section 12 generates a record conveyed along the conveyance path T by the conveyance section 17 based on image data generated by the image reading section 11 or image data inputted via the communication section 22. An image composed of toner images is formed on paper P.

The fixing section 13 fixes the toner image onto the recording paper P by heating and pressurizing the recording paper P on which the toner image has been formed by the image forming section 12 . The recording paper P on which the toner image has been fixed by the fixing section 13 is transported by the transport section 17 and discharged onto the discharge tray 8 .

The paper feed section 14 includes a manual feed tray and a plurality of paper feed cassettes. The paper feed unit 14 uses a pickup roller to pull out the recording paper P stored in one of the plurality of paper feed cassettes or the recording paper placed on the manual feed tray one by one, and feeds the paper into the transport path T. do.

The display unit 15 is a liquid crystal display, an organic EL (Organic Light-Emitting Diode) display, or the like. The display unit 15 displays various screens regarding each process that can be executed by the image forming apparatus 1.

The operation unit 16 includes a plurality of hard keys such as a start key 16A for inputting instructions to start execution of each process executable by the image forming apparatus 1. The operation unit 16 also includes a touch panel 16B disposed overlapping the display unit 15. A user's instructions are input into the operation unit 16.

The transport unit 17 includes a transport roller pair 17A, a discharge roller pair 17B, and the like, and a transport motor connected to the transport roller pair 17A, the discharge roller pair 17B, and the like. As the transport roller pair 17A, ejection roller pair 17B, etc. rotate due to the drive of the transport motor, the recording paper P fed by the paper feed section 14 is transported along the transport path T toward the image forming section 12 and the ejection tray 8. transported along.

Image forming apparatus 1 also includes a control unit 100 . The control unit 100 includes a processor, a RAM (Random Access Memory), a ROM (Read Only Memory), and the like. The processor is, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or an ASIC (Application Specific Integrated Circuit).

The control unit 100 includes a document transport section 6, an image reading section 11, an image forming section 12, a fixing section 13, a paper feeding section 14, a display section 15, an operation section 16, a transport section 17, an HDD (Hard Disk Drive) 18, and an image forming section 12. It is electrically connected to a processing section 19, an image memory 20, a facsimile communication section 21, a communication section 22, and the like. The document transport section 6 , the image reading section 11 , the display section 15 , the operation section 16 , the HDD 18 , and the control unit 100 constitute the document reading device 5 .

The control unit 100 functions as the control section 10 by executing a control program stored in the ROM or HDD 18 by the processor. The control unit 10 is in charge of overall control of the image forming apparatus 1 . That is, the control section 10 controls the operation of each section of the image forming apparatus 1. Note that the control unit 10 may be configured by a logic circuit instead of operating based on the control program described above.

The HDD 18 is a large-capacity storage device for storing various data such as image data. The HDD 18 stores various control programs for realizing general operations of the image forming apparatus 1. The HDD 18 stores, as one of the various control programs described above, a change control program for executing a conveyance direction change process according to an embodiment of the present invention.

The image processing section 19 performs image processing on the image data generated by the image reading section 11 as necessary. The image memory 20 includes an area for temporarily storing image data generated by the image reading section 11. The facsimile communication unit 21 connects to a public line and sends and receives image data via the public line.

The communication unit 22 includes a communication module such as a LAN (Local Area Network) board. The communication unit 22 performs data communication with an external device such as a PC (Personal Computer) 23 via a network.

A power supply is connected to each part of the image forming apparatus 1, and each part of the image forming apparatus 1 operates by being supplied with power from the power supply.

Here, the configurations of the document transport section 6 and the image reading section 11 will be explained in detail. FIG. 3 is a cross-sectional view showing the configuration of the document transport section 6 and the image reading section 11. As shown in FIG. 3, the image reading section 11 includes a first reading section 40 and a second reading section 50 built into the document transport section 6.

[Configuration of document transport section 6]
The document conveyance section 6 includes a document placement tray 24, a first discharge tray 25, a second discharge tray 26, a first conveyance path F1, a second conveyance path F2, a switching section 27, a conveyance section 28, It includes a first sensor 29A and a second sensor 29B. The document transport section 6 is provided on the upper surface of the second reading section 50 so that it can be opened and closed by a hinge or the like. The document transport section 6 functions as a document holding cover for holding down the document MS placed on the contact glass 52.

The original MS is placed on the original placing tray 24 with the leading edge of the original MS in the conveyance direction being located at a predetermined first position. The original MS is ejected to the first ejection tray 25 and the second ejection tray 26 . The first conveyance path F1 is a straight path that extends from the document placement tray 24 to the first discharge tray 25 without curving. The second conveyance path F2 is branched from the first conveyance path F1 on the downstream side of the first reading unit 40 in the document conveyance direction, and is formed to curve downward and extend toward the second discharge tray 26. It is a character path.

The switching section 27 is a claw member provided at a branch point between the first conveyance path F1 and the second conveyance path F2. The switching unit 27 switches the document transport direction beyond the branch point to the first transport path F1 or the second transport path F2. The conveyance section 28 includes a pickup roller 31, a paper feed roller pair 32, a shading roller 33, a plurality of conveyance roller pairs 34, a first ejection roller pair 35, and a second ejection roller pair 36.

The pickup roller 31 pulls out the documents MS placed on the document tray 24 one by one and sends them out toward the pair of paper feed rollers 32 . The paper feeding roller pair 32 feeds the original MS sent from the pickup roller 31 to the original transport path F1. The shading roller 33 is arranged to face the first reading section 40 . The plurality of conveyance roller pairs 34 are arranged along the first conveyance path F1 and the second conveyance path F2.

The shading roller 33 and the plurality of transport roller pairs 34 transport the document MS fed by the paper feed roller pair 32 along the first transport path F1 and the second transport path F2. The first ejection roller pair 35 ejects the document MS transported along the first transport path F1 onto the first ejection tray 25. The second discharge roller pair 36 discharges the document MS conveyed along the second conveyance path F2 onto the second discharge tray 26.

When the document conveyance direction is switched to the first conveyance path F1 by the switching section 27, the conveyance section 28 horizontally transports the document MS from the document placement tray 24 to the first discharge tray 25 through the first conveyance path F1. transport. When the document conveyance direction is switched to the second conveyance path F2 by the switching section 27, the conveyance section 28 conveys the document MS from the document placement tray 24 through the first conveyance path F1 to the above-mentioned branch point. , and is transported from the branch point to the second discharge tray 26 through the second transport path F2.

The first sensor 29A and the second sensor 29B are not particularly limited as long as they are sensors that can detect the document MS, but here, reflective optical sensors including a light emitting element and a light receiving element are used. The first sensor 29A and the second sensor 29B output an OFF signal when the original MS is not detected, and output an ON signal when the original MS is detected. The first sensor 29A is provided at the first position on the document tray 24. The first sensor 29A detects the presence or absence of the document MS on the document tray 24.

The second sensor 29B is provided at a predetermined second position on the document tray 24. The second position is not particularly limited as long as it is possible to specify that the length of the document MS in the transport direction is equal to or larger than a predetermined length (long size). Here, the second position is a position that is separated from the first position in the document transport direction by a distance corresponding to 1.2 times the longitudinal length (297 mm) of A4 size, which is a standard size. It is assumed that this has been set. The first sensor 29A and the second sensor 29B are an example of a "document length detection section" in the claims.

The document transport section 6 further includes a document guide 37 and a third sensor 38. The document guide 37 is provided on the document tray 24 so as to be slidable in a direction perpendicular to the document conveyance direction (that is, in the width direction of the document MS). The document guide 37 regulates the position of the document MS from both sides in the width direction of the document MS by sliding movement.

The third sensor 38 is not particularly limited as long as it is a sensor capable of detecting a state in which the original MS is fed diagonally (hereinafter referred to as "skew feeding"), but here, as shown in FIG. , a transmission type optical sensor including a light emitting element 38A and a light receiving element 38B is used. The light-emitting element 38A and the light-receiving element 38B are provided above the document tray 24, one each at positions on both sides in the width direction of the document MS placed on the document tray 24. For example, the light emitting element 38A is provided at the upstream end of the main body frame of the original transport section 6 in the transporting direction of the original MS, at one side end in the width direction, and the light receiving element 38A is provided at the other side end. 38B is provided. The light emitting element 38A and the light receiving element 38B are provided at a position where the light emitted from the light emitting element 38A is received by the light receiving element 38B. The third sensor 38 detects the skew of the original MS by detecting the original MS floating on the original guide 37.

Specifically, in a state where the original MS does not ride on the original guide 37 and the emitted light from the light emitting element 38A is not blocked, the light receiving element 38B receives the emitted light and outputs an ON signal. On the other hand, in a state where the emitted light from the light emitting element 38A is blocked by the overturned original MS riding on the original guide 37, the light receiving element 38B outputs an OFF signal without receiving the emitted light. The third sensor 38 is an example of a "skew detection section" in the claims.

[Configuration of image reading unit 11]
The first reading unit 40 is a contact image sensor (CIS) provided on the first conveyance path F1. The first reading unit 40 reads an image on one side (in this case, the bottom side) of the document MS. Specifically, the first reading unit 40 transmits light from, for example, an LED (Light Emitting Diode) through a contact glass to one side of the original MS transported along the first transport path F1 using the original moving method. The light reflected from the one surface is received by a CMOS (Complementary Metal Oxide Semiconductor) image sensor, and an image of the one surface is read.

The second reading unit 50 includes a contact glass 51, a contact glass 52, a white reference plate 53, a carriage 54, an optical system unit 55, a condenser lens 56, a CCD (Charge Coupled Device) sensor 57, and the like. The carriage 54 includes a linear LED (Light Emitting Diode) array 54A for irradiating light onto the original MS, and a mirror 54B for receiving reflected light from the original MS and reflecting it toward the optical system unit 55. Equipped with.

The optical system unit 55 includes mirrors 55A and 55B. Mirror 55A reflects the light guided from mirror 54B and guides it to mirror 55B. Mirror 55B reflects the light guided from mirror 55A and guides it to CCD sensor 57 through condenser lens 56. The carriage 54 and the optical system unit 55 are configured to be able to reciprocate in the sub-scanning direction by a moving mechanism.

The second reading unit 50 reads an image on the other surface (in this case, the top surface) of the document MS that is conveyed along the second conveyance path F2 using the document movement method. Specifically, with the carriage 54 and the optical system unit 55 stationary at the home position shown in FIG. The array 54A is irradiated with light, and the CCD sensor 57 reads an image of the other surface.

In the case of the document fixing method, the second reading section 50 reads an image of one side of the document MS placed on the contact glass 52. Specifically, the second reading section 50 moves the carriage 54 and the optical system unit 55 at a constant speed in the sub-scanning direction, and scans one side of the document MS placed on the contact glass 52. The surface is irradiated with light from the LED array 54A, and an image of the one surface is read by the CCD sensor 57.

In the present embodiment, by operating according to the change control program, the control unit 10 instructs the switching unit 27 to switch to a branch point when the length of the document MS in the transport direction is equal to or greater than a predetermined length. If the original transport direction ahead of the branch point is set to the first transport path F1, and the length of the original MS in the transport direction is less than a predetermined length, the switching unit 27 selects the original transport direction ahead of the branch point. A conveyance direction change process is executed to change the conveyance direction to the second conveyance path F2.

[motion]
FIG. 4 is a flowchart showing the conveyance direction changing process. FIG. 5 is a diagram illustrating the situation when the original MS is being fed obliquely. Hereinafter, with reference to FIGS. 4, 5, etc., the operation of the document reading device 5 during execution of the conveyance direction changing process will be described.

In the following description, it is assumed that in the initial state, the control section 10 sets the position of the switching section 27 at a position where the document conveyance direction from the above-mentioned branch point is the second conveyance path F2. Further, it is assumed that one document MS is placed on the document placement tray 24.

It is assumed that the user places a single document MS face down on the document tray 24 and uses the operation unit 16 to input an instruction to read one side or both sides of the document. When the control unit 10 receives a one-sided reading instruction or a two-sided reading instruction via the operation unit 16, it starts executing the conveyance direction changing process shown in FIG.

When execution of the conveyance direction changing process is started, the control unit 10 determines whether the document MS is of long size based on the detection results of the first sensor 29A and the second sensor 29B (step S10). Specifically, if ON signals are input from both the first sensor 29A and the second sensor 29B, the control unit 10 determines that the document MS is of long size. On the other hand, if the ON signal is input from the first sensor 29A and the OFF signal is input from the second sensor 29B, the control unit 10 determines that the document MS is not of long size.

(1) When the manuscript MS is a long size Here, it is assumed that the manuscript MS is a long size with a length of 900 mm in the longitudinal direction. In this case, both the first sensor 29A and the second sensor 29B output an ON signal. Therefore, the control unit 10 determines that the document MS is of long size (YES in step S10), and the position of the switching unit 27 is determined regardless of whether the instruction to read one side of the document or the instruction to read both sides of the document is accepted. is moved to switch the document conveyance direction beyond the above-mentioned branch point to the first conveyance path F1 (step S11).

After the process in step S11, the control unit 10 causes the transport unit 28 to start transporting the original MS (step S12). After the process in step S12, the control unit 10 determines whether the third sensor 38 detects skew feeding of the original MS or completes feeding of the original MS without detecting skew feeding of the original MS by the third sensor 38. Until this happens, the process of determining that the document MS is not skewed (NO in step S13) and the process of determining that feeding of the document MS is not completed (NO in step S14) are repeated.

(1-1) When the original MS is not skewed Here, the pickup roller 31 and the pair of paper feed rollers 32 prevent the original MS from shifting along the original transport path with respect to the width direction perpendicular to the original transport direction. It is assumed that the document MS is normally fed to F1 and the trailing edge of the document MS passes the first sensor 29A.

In this case, the original MS does not ride on the original guide 37 and the emitted light from the light emitting element 38A of the third sensor 38 is not blocked, so the light receiving element 38B receives the emitted light and outputs an ON signal. Furthermore, as the rear end passes, the first sensor 29A outputs an OFF signal.

Therefore, the control unit 10 determines that the document MS is not skewed based on the ON signal input from the light emitting element 38A (NO in step S13), and also determines that the document MS is not skewed based on the OFF signal input from the first sensor 29A. Based on this, it is determined that the feeding of the original MS has been completed (YES in step S14), and the conveyance direction changing process is ended.

As described above, when the switching unit 27 sets the document transport direction beyond the branching point to the first transport path F1, the control unit 10 controls the shading roller 33 and the transport roller pair 34 to The document MS fed by the paper roller pair 32 or the like is horizontally transported toward the first discharge tray 25 along the first transport path F1. The control unit 10 causes the first reading unit 40 to read an image on one side (in this case, the bottom side) of the document MS transported along the first transport path F1. The control section 10 causes the first ejection roller pair 35 to eject the document MS that has passed through the first reading section 40 onto the first ejection tray 25 .

(1-2) Case where the original MS is skewed As shown in FIG. do. As a result of the paper feeding, the degree of displacement of the original MS increases as it approaches the rear end in the original transport direction, and the rear end of the original MS in the original transport direction rides on the original guide 37 and is turned over. In this case, since the emitted light from the light emitting element 38A is blocked by the turning of the document MS, the light receiving element 38B outputs an OFF signal without receiving the emitted light.

Therefore, the control unit 10 determines that the original MS is traveling diagonally based on the OFF signal input from the light emitting element 38A (YES in step S13), and instructs the transport unit 28 to transport the original MS. It is stopped (step S15). The control unit 10 also causes the display unit 15 to display a message indicating that a feeding error has occurred in the document MS (step S16). After the process of step S16, the control unit 10 ends the conveyance direction changing process.

(2) When the manuscript MS is a standard size Here, it is assumed that the manuscript MS is A4 size with a longitudinal length of 297 mm. In this case, the first sensor 29A outputs an ON signal, and the second sensor 29B outputs an OFF signal. Therefore, the control unit 10 determines that the original MS is not of long size (NO in step S10), and causes the transport unit 28 to start transporting the original MS without moving the position of the switching unit 27. (Step S17). As a result, the document transport direction beyond the branch point remains in the second transport path F2. After the process in step S17, the control unit 10 ends the conveyance direction changing process.

As described above, when the switching unit 27 sets the document transport direction beyond the branch point to the second transport path F2, the control unit 10 controls the shading roller 33 and the transport roller pair 34 to The document MS fed by the pair of paper rollers 32 and the like is horizontally transported along the first transport path F1 to the above-mentioned branch point. The control unit 10 causes the first reading unit 40 to read an image on one side (in this case, the bottom side) of the document MS transported along the first transport path F1.

The control unit 10 causes the pair of transport rollers 34 to transport the document MS that has passed through the branch point toward the second discharge tray 26 along the second transport path F2. When the control unit 10 receives a double-sided reading instruction via the operation unit 16, the control unit 10 instructs the second reading unit 50 to scan the other side of the document MS conveyed along the second conveyance path F2 (in this case, The image on the top) is read. The control unit 10 causes the second discharge roller pair 35 to discharge the document MS that has passed through the second reading unit 50 onto the second discharge tray 26 .

According to the embodiment described above, when the length of the document MS in the conveyance direction is equal to or greater than a predetermined length, the control section 10 causes the switching section 27 to set the document conveyance direction to the first conveyance path F1. , when the length of the original MS in the transport direction is less than a predetermined length, the switching unit 27 causes the original transport direction to be set to the second transport path F2.

As a result, if the length of the document MS in the conveyance direction is equal to or greater than a predetermined length, the document MS is conveyed through the uncurved first conveyance path F1 and is discharged onto the first discharge tray 25. Therefore, it is possible to prevent the document MS from being damaged when sending the long size document MS.

Further, according to the embodiment described above, when the third sensor 38 detects the skewed feeding of the original MS, the control unit 10 causes the transport unit 28 to stop transporting the original MS. Thereby, it is possible to prevent the original MS from being fed to the first transport path F1 in a skewed and turned-over state, so that the original MS can be appropriately protected.

Further, according to the embodiment described above, even when the control unit 10 receives an instruction to read both sides of the original MS via the operation unit 16, the length of the original MS in the transport direction is set to the predetermined length. If it is more than 1, the switching unit 27 causes the document transport direction beyond the branch point to be the first transport path F1.

This can prevent the image on the other side of the document MS from being read by the second reading section 50 in a state where the document MS is damaged. Therefore, unnecessary reading operations can be avoided, and damage to the original MS can be more reliably prevented.

(Other variations)
In the embodiment described above, the control unit 10 determines whether the length of the document MS in the conveyance direction is equal to or greater than a predetermined length (long size) based on the signals input from the first sensor 29A and the second sensor 29B. Although it has been determined that there are some embodiments, the present invention is not limited to such embodiments. For example, the control unit 10 may determine whether the length of the document MS in the transport direction is equal to or greater than a predetermined length based on the document size input by the user via the operation unit 16. good. In this case, the operation section 16 functions as a "document length detection section" in the claims.

Further, in the embodiment described above, the control unit 10 determines whether or not the document MS is skewed based on the signal input from the light receiving element 38B of the third sensor 38. Not limited to form. For example, instead of the third sensor 38, a sensor for detecting the original MS riding on the original guide 37 is directly provided on the original guide 37, and the control unit 10, based on the signal output from the sensor, It may also be determined whether the document MS is skewed.

Further, in the embodiment described above, the image forming section 12 and the like record an image on the recording paper P, but the present invention is not limited to such an embodiment. The image forming unit 12 and the like may record images not only on the recording paper P but also on other recording media. As another recording medium, for example, an OHP (Overhead Projector) sheet can be exemplified.

Note that the present invention is not limited to the configuration of the above embodiment, and various modifications are possible. For example, in the embodiment described above, a color multifunction device is used as an image forming device equipped with a document reading device, but this is only an example, and other image forming devices such as a monochrome multifunction device, a copy machine, or a facsimile device are used. may be used.

The configuration and processing of the embodiment described above using FIGS. 1 to 5 are merely one embodiment of the present invention, and the present invention is not intended to be limited to the configuration and processing.

1 Image forming device 5 Document reading device 10 Control section 12 Image forming section 16 Operation section 24 Document placement tray 25 First ejection tray 26 Second ejection tray 27 Switching section 28 Conveyance section 37 Document guide 38 Third sensor 40 First reading Part F1 First conveyance path F2 Second conveyance path

Claims (4)

a document tray on which the document is placed;
a first ejection tray and a second ejection tray from which the original is ejected;
a first conveyance path extending from the document placement tray to the first output tray without curving;
a first reading unit provided on the first conveyance path and reading an image on one side of the document;
a second conveyance path that branches from the first conveyance path on the downstream side of the first reading unit in the document conveyance direction and extends in a curved manner toward the second discharge tray;
a switching unit that is provided at the branch point and switches the document conveyance direction beyond the branch point to the first conveyance path or the second conveyance path;
When the document conveyance direction is switched to the first conveyance path by the switching unit, the document is conveyed from the document placement tray to the first ejection tray through the first conveyance path, and When the document conveyance direction is switched to the second conveyance path by the section, the document is conveyed from the document placement tray to the branch point through the first conveyance path, and the document is conveyed through the second conveyance path. a conveyance unit that conveys the material from the branch point to the second discharge tray through the
a document length detection unit that detects the length of the document in the transport direction;
When the length of the document in the conveyance direction detected by the document length detection section is equal to or greater than a predetermined length, the switching section changes the document conveyance direction beyond the branch point to the first direction. If the length of the document in the conveyance direction is less than the predetermined length, the switching unit causes the document conveyance direction beyond the branch point to be set to the second conveyance path. A document reading device, comprising: a control unit that performs the following operations. a document guide provided on the document placement tray and regulating the position of the document in a width direction perpendicular to the document conveyance direction from both sides of the document in the width direction;
a skew detection unit that detects skew of the document by detecting the document riding on the document guide;
The document reading device according to claim 1, wherein the control section causes the transport section to stop transporting the document when the skew detection section detects the skew of the document. a second reading unit provided on the second conveyance path and reading an image on the other side of the document;
further comprising: an operation section into which a user's instructions are input;
Even when the control unit receives an instruction to read both sides of the document via the operation unit, if the length of the document in the transport direction is equal to or greater than the predetermined length, The document reading device according to claim 1 , wherein the switching unit causes the document conveyance direction beyond the branch point to be the first conveyance path. A document reading device according to claim 1 or claim 2;
An image forming apparatus, comprising: an image forming section that forms an image read by the document reading device on a recording medium.