Image reading device, and image forming apparatus

Abstract

To prevent a change in a bent state of an FFC connected to an image pick-up device when the image pick-up device is moved in a sub-scanning direction.SOLUTION: An image reading device 11 comprises: a CIS unit 43 that is moved in a sub-scanning direction X below a platen glass 41 and reads an image of a document placed on the platen glass 41 repeatedly in a main scanning direction Y; an FFC 51 that is connected to the CIS unit 43 and is folded and bent in the sub-scanning direction X below the CIS unit 43; a slider 53 that is engaged with the FFC 51 freely movably in a longitudinal direction of the FFC 51; a string-like member 54 that is connected to the slider 53; a roller 55 that takes up and feeds out the string-like member 54; and a motor 56 that rotates the roller 55 in a reciprocating manner.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an image reading device that reads an image on a document and an image forming apparatus equipped with the same, and more particularly to a technique for adjusting the bending state of a flexible flat cable connected to a scanner of the image reading device. [Background technology]

[0002] As shown in FIG. 13A, an image reading device includes a contact image sensor (CIS) 72 that moves in the sub-scanning direction X below a platen glass 71 and repeatedly reads an image of a document placed on the platen glass 71 in the main scanning direction, and a flexible flat cable (FFC) 73 that is connected to the CIS 72 and bent in the sub-scanning direction X below the CIS 72. However, as shown in FIG. 13B, as the CIS 72 moves in the sub-scanning direction X, the bending state of the FFC 73 changes significantly. If the CIS 72 comes into contact with the rear surface of the platen glass 71, static electricity may be generated on the rear surface of the platen glass 71, causing the rear surface of the platen glass 71 to become dirty. Furthermore, the change in the bending state of the FFC 73 may cause a change in the load on the CIS 72, resulting in unstable movement of the CIS 72 in the sub-scanning direction X. In particular, in a thin image reading device, the FFC 73 is more likely to bend and come into contact with the rear surface of the platen glass 72.

[0003] In the reader described in Patent Document 1, the FFC is connected to the CIS unit from the left side, and when the CIS unit is in the standby position, the FFC is bent back to the right from the part connected to the CIS unit. The bottom of the reader is provided with an upper base that is one step higher to the left of the curved part of the FFC, and the rear extension of the FFC is held in the space below this upper base. This allows the flat cable to move smoothly in response to the movement of the CIS unit while suppressing an increase in the height of the reader. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-017631 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, when the CIS unit is in the standby position, the FFC is bent back to the right from the part connected to the CIS unit, so that the FFC does not come into contact with the contact glass. However, there is no particular adjustment for the bent state of the FFC when the CIS unit moves away from the standby position, so there is a possibility that the FFC may come into contact with the contact glass.

[0006] The present invention has been made in consideration of the above circumstances, and aims to suppress changes in the bending state of a flexible flat cable connected to an imaging element when the imaging element is moved in the sub-scanning direction, thereby enabling smooth movement of the imaging element in the sub-scanning direction. [Means for solving the problem]

[0007] An image reading device according to one aspect of the present invention comprises an imaging element that is moved in the sub-scanning direction below a platen glass and repeatedly reads an image of a document placed on the platen glass in the main scanning direction; a flexible flat cable that is connected to the imaging element and is folded back and bent in the sub-scanning direction below the imaging element; a slider that is engaged with the flexible flat cable so as to be movable in the longitudinal direction of the flexible flat cable; a string-like member connected to the slider; a roller that winds up and feeds out the string-like member; and a first motor that rotates the roller back and forth.

[0008] Furthermore, an image forming apparatus according to one aspect of the present invention includes the image reading device of the present invention described above, and an image forming unit that forms the image portion read and extracted by the image reading device on recording paper. [Effects of the Invention]

[0009] According to the present invention, when the imaging element is moved in the sub-scanning direction, changes in the bending state of the flexible flat cable connected to the imaging element are suppressed, enabling smooth movement of the imaging element in the sub-scanning direction. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing an image forming apparatus to which an image reading apparatus according to an embodiment of the present invention is applied. [Figure 2] 1 is a perspective view showing the appearance of an image reading device according to an embodiment of the present invention, with a document transport unit in an open state. [Figure 3] 1A is a plan view schematically showing a reading unit of an image reading device, and FIG. 1B is a cross-sectional view showing the reading unit. [Figure 4] FIG. 1A is a plan view showing an enlarged view of the CIS unit, FFC, slider, string-like member, roller, motor, and each guide part in the reading part of the image reading device, and FIG. 1B is a cross-sectional view showing an enlarged view of the CIS unit, FFC, slider, and platen glass. [Figure 5] FIG. 2 is an enlarged perspective view of a slider. [Figure 6] 1 is a perspective view showing a state in which a slider is engaged with an FFC so as to be movable in the longitudinal direction of the FFC. FIG. [Figure 7] FIG. [Figure 8] FIG. 2 is a perspective view showing a string-like member. [Figure 9] 1A is a plan view schematically showing the reading section of the image reading device when the CIS unit is moved to the vicinity of the center of the platen glass, and FIG. 1B is a cross-sectional view showing the bent state of the FFC at that time. [Figure 10] 10 is a plan view schematically showing the reading unit of the image reading device when the CIS unit is moved to the vicinity of the rear end of the platen glass. FIG. [Figure 11]1 is a block diagram showing a main internal configuration of an image forming apparatus; [Figure 12] 4 is a flowchart showing a control procedure of the image forming apparatus. [Figure 13] FIG. 1A is a cross-sectional view showing a schematic diagram of a conventional image reading device, and FIG. 1B is a cross-sectional view showing a state in which an FFC is in contact with a platen glass. DETAILED DESCRIPTION OF THE INVENTION

[0011] An image reading device according to one embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing an image forming apparatus to which an image reading device according to one embodiment of the present invention is applied. As shown in FIG. 1, the image forming apparatus 10 is an MFP (multi-function peripheral) that combines multiple functions such as a copy function and a printer function. The image forming apparatus 10 includes an image reading device 11 and an image forming unit 12.

[0012] The image reading device 11 has, for example, a contact image sensor (CIS) as an imaging element (scanner) that optically reads an image of a document. Image data representing the image of the document is output from the CIS as an imaging element.

[0013] The image forming unit 12 forms an image represented by the image data on recording paper. The image forming unit 12 includes a magenta image forming unit 3M, a cyan image forming unit 3C, a yellow image forming unit 3Y, and a black image forming unit 3Bk. Each of the image forming units 3M, 3C, 3Y, and 3Bk uniformly charges the surface of the photosensitive drum 4, exposes the surface of the photosensitive drum 4 to light, forms an electrostatic latent image on the surface of the photosensitive drum 4, develops the electrostatic latent image on the surface of the photosensitive drum 4 into a toner image, and primarily transfers the toner image on the surface of the photosensitive drum 4 to the intermediate transfer belt 5. This forms a color toner image on the intermediate transfer belt 5. This color toner image is then secondarily transferred to the recording paper P, which has been transported from the paper feed unit 14 through the transport path 8, in the nip region N between the intermediate transfer belt 5 and the secondary transfer roller 6.

[0014] Thereafter, the recording paper P is heated and pressed in the fixing device 15, the toner image on the recording paper P is fixed by heat and pressure, and the recording paper P is then discharged onto a discharge tray 17 via discharge rollers 16.

[0015] Next, the image reading device 11 will be described. FIG. 2 is a perspective view showing the appearance of the image reading device 11, illustrating a state in which the document transport unit 21 is open. As shown in FIG. 2, the image reading device 11 includes the document transport unit 21 and a reading unit 22. The document transport unit 21 is a so-called automatic document feeder (ADF), and is supported so as to be openable and closable by two hinges 23 provided at one end of the upper surface of the reading unit 22. When the document transport unit 21 is closed and stacked on the reading unit 22, the document transport unit 21 pulls out and transports multiple documents set in the document tray 24 one by one, and passes them over the leading edge of the platen glass 41 of the reading unit 22.

[0016] The reading unit 22 includes a platen glass 41, a CIS unit 43 that includes a CIS, and the like.

[0017] FIG. 3A is a plan view that schematically shows the reading unit 22 of the image reading device 11, and FIG. 3B is a cross-sectional view that shows the reading unit 22. As shown in FIG.

[0018] The CIS and CIS unit 43 extend in the main scanning direction Y. The CIS unit 43 moves in a sub-scanning direction X perpendicular to the main scanning direction Y below the platen glass 41, and repeatedly reads the image of the document placed on the platen glass 41 at each position in the sub-scanning direction.

[0019] 3(A) and 3(B), the reading unit 22 includes a CIS unit 43, a guide rail 44 that guides the CIS unit 43 in the sub-scanning direction X, an endless belt 47 that is stretched over a pair of pulleys 45, 46 and connected to the CIS unit 43, a motor (second motor) 48 that rotates one of the pulleys 46 to move the endless belt 47 in a circular motion, and a biasing unit 49 that biases the other pulley 45 in a direction away from the one pulley 46 to apply tension to the endless belt 47. When the pulley 46 is rotated by the motor 48, the endless belt 47 moves in a circular motion, and the CIS unit 43 is moved in the sub-scanning direction X and guided by the guide rail 44.

[0020] A platen glass 41 is provided on the top plate of the housing 22A of the reading unit 22. As described above, when the document set in the document tray 24 is pulled out and transported by the document transport unit 21 and the document passes over the platen glass of the reading unit 22, the CIS unit 43 is moved below the leading edge of the platen glass 41. The CIS of the CIS unit 43 repeatedly reads the image of the document transported in the sub-scanning direction X in the main scanning direction Y via the leading edge of the platen glass 41, and outputs image data representing the image of the document.

[0021] Furthermore, when a document is placed on the platen glass 41 of the reading unit 22, the CIS unit 43 is moved in the sub-scanning direction X below the platen glass 41. While being moved in the sub-scanning direction X, the CIS of the CIS unit 43 repeatedly reads the image of the document in the main scanning direction Y through the platen glass 41, and outputs image data representing the image of the document.

[0022] A flexible flat cable (FFC) 51 for transmitting signals and power is connected to the CIS of the CIS unit 43. One end of the FFC 51 is connected to the CIS, is folded back and bent in the sub-scanning direction below the CIS, and the other end is attached to the bottom (bottom plate) 22B inside the housing 22A. In FIGS. 3A and 3B, one end of the FFC 51 is connected to the CIS, extends to the left, and is folded back and bent to the right below. In this embodiment, the FFC 51 is connected to a connector 52 fixed to the bottom 22B of the housing 22A.

[0023] The FFC 51 has a length that allows it to bend and deform as the CIS unit 43 moves in the sub-scanning direction X, and to maintain the connection between the CIS and the connector 52 .

[0024] If the FFC 51 is bent and deformed and comes into contact with the rear surface of the platen glass 41, static electricity may be generated on the rear surface of the platen glass 41, which may contaminate the rear surface of the platen glass 41. Furthermore, if the bending state of the FFC 51 changes significantly, the load on the CIS unit 43 may fluctuate, making the movement of the CIS unit 43 in the sub-scanning direction X unstable.

[0025] Therefore, the image reading device 11 of this embodiment is provided with a slider 53 engaged with the FFC 51 so as to be movable in the longitudinal direction of the FFC 51, a string-like member 54 connected to the slider 53, guide sections 57 that guide the string-like member 54, rollers 55 that wind and feed the string-like member 54, and a motor (first motor) 56 that reciprocates the rollers 55. The rollers 55 adjust the amount of winding and feeding of the string-like member 54, and the slider 53 constantly pulls the FFC 51, suppressing changes in the bending state of the FFC 51.

[0026] Fig. 4(A) is an enlarged plan view showing the CIS unit 43, the FFC 51, the slider 53, the string-like member 54, the roller 55, the motor 56, and the guide parts 57. Fig. 4(B) is an enlarged cross-sectional view showing the CIS unit 43, the FFC 51, the slider 53, and the platen glass 41.

[0027] 4(A) and (B), one end 51A of the FFC 51 is folded inward at a right angle and then folded again at a right angle toward the CIS unit 43 and connected to the CIS. A slider 53 is engaged with the FFC 51. A ring 54A at the end of a string-like member 54 is connected to the slider 53, and the string-like member 54 is guided by each guide portion 57 and wound around a roller 55. When the roller 55 is rotated back and forth by a motor 56, the string-like member 54 is wound around the roller 55 or fed out from the roller 55.

[0028] Fig. 5 is an enlarged perspective view of slider 53. As shown in Fig. 5, slider 53 includes frame portion 53A that is open at the top, protrusion 53B that protrudes rearward from the center of frame portion 53A, hook 53C that protrudes upward from protrusion 53B, and guide piece 53D that protrudes downward from the center of frame portion 53A.

[0029] Fig. 6 is a perspective view showing a state in which the slider 53 is engaged with the FFC 51 so as to be freely movable in the longitudinal direction of the FFC 51. As shown in Fig. 6, a guide groove 22C extending in the sub-scanning direction X is formed in the bottom 22B of the housing 22A of the reading unit 22, and a guide piece 53D of the slider 53 is fitted into the guide groove 22C, so that the slider 53 is supported so as to be freely movable along the guide groove 22C. The FFC 51 is bent downward and to the right, abuts against the upper end of the hook 53C, and is supported by being freely movably passed inside the frame portion 53A of the slider 53.

[0030] Fig. 7 is a perspective view showing roller 55. As shown in Fig. 7, a hole 55A is formed in the center of roller 55, and the shaft of motor 56 is passed through this hole 55A to connect the shaft of motor 56 to roller 55. The upper half of roller 55 is a cylindrical portion 55B, and a plurality of flanges 55C protruding outward are provided on the upper edge of cylindrical portion 55B.

[0031] Fig. 8 is a perspective view showing string-like member 54. As shown in Fig. 8, string-like member 54 is, for example, a thin belt-like member that is wound around cylindrical portion 55B of roller 55 and guided by two guide portions 57, with ring 54A provided at the tip of string-like member 54 being led to slider 53. As shown in Fig. 6, ring 54A is attached by being fitted into hook 53C of slider 53.

[0032] In the reading unit 22 of the image reading device 11 configured as described above, the motor 56 rotates the roller 55 back and forth, the roller 55 adjusts the amount of winding and feeding of the string-like member 54, and the slider 53 constantly pulls the FFC 51, thereby suppressing changes in the bending state of the FFC 51.

[0033] 4A and 4B, when the CIS unit 43 is moving near the leading edge of the platen glass 41, the bent portion of the FFC 51 also moves near the leading edge of the platen glass 41, so that the motor 56 rotates the roller 55 in the forward direction, increasing the amount of string-like member 54 wound around the roller 55 and shortening the distance in the sub-scanning direction X from each guide portion 57 to the ring 54A of the string-like member 54. As a result, the ring 54A of the string-like member 54 pulls the slider 53, causing the slider 53 to move along the FFC 51 toward the CIS unit 43, and the slider 53 pulls the FFC 51, bending it in a small arc and elastically deforming it. As a result, the FFC 51 does not come close to the rear surface of the platen glass 41.

[0034] 3A and 3B, as the CIS unit 43 moves in the sub-scanning direction and begins to move away from the leading edge of the platen glass 41, the bent portion of the FFC 51 moves. At this time, the motor 56 rotates the roller 55 in the reverse direction, and while the string-like member 54 is fed from the roller 55, the amount of string-like member 54 fed is limited. As a result, the ring 54A of the string-like member 54 pulls the slider 53, causing it to move along the FFC 51. The slider 53 moves away from the CIS unit 43, and the portion of the FFC 51 from the slider 53 to the CIS unit 43 becomes longer. However, at the same time, the slider 53 pulls the bent portion of the FFC 51, so the arc described by the FFC 51 remains substantially unchanged, and the FFC 51 does not approach the rear surface of the platen glass 41. Furthermore, the load on the CIS unit 43 does not fluctuate, stabilizing the movement of the CIS unit 43 in the sub-scanning direction X.

[0035] 9(A) and 9(B), when the CIS unit 43 moves to near the center of the platen glass 41 in the sub-scanning direction, the bent portion of the FFC 51 also moves. At this time, the motor 56 rotates the roller 55 in the reverse direction, and while the string-like member 54 is further fed from the roller 55, the amount of feed of the string-like member 54 is limited. As a result, the ring 54A of the string-like member 54 pulls the slider 53 and moves it along the FFC 51, moving the slider 53 further away from the CIS unit 43 and further lengthening the portion of the FFC 51 from the slider 53 to the CIS unit 43. However, at the same time, the slider 53 pulls the bent portion of the FFC 51, so the arc described by the FFC 51 remains substantially unchanged, and the FFC 51 does not approach the rear surface of the platen glass 41. Furthermore, the load on the CIS unit 43 does not fluctuate, stabilizing the movement of the CIS unit 43 in the sub-scanning direction X.

[0036] 10 , when the CIS unit 43 moves near the rear end of the platen glass 41, the bent portion of the FFC 51 also moves. At this time, the motor 56 rotates the roller 55 in the reverse direction, causing the string-like member 54 to be further fed out from the roller 55. However, the amount of string-like member 54 fed out from the roller 55 is limited. Therefore, the ring 54A of the string-like member 54 pulls the slider 53, causing it to move along the FFC 51. The slider 53 moves further away from the CIS unit 43, and the portion of the FFC 51 from the slider 53 to the CIS unit 43 becomes longer. However, because the slider 53 still pulls the bent portion of the FFC 51, the arc described by the FFC 51 remains substantially unchanged, and the FFC 51 does not approach the rear surface of the platen glass 41. Furthermore, the load on the CIS unit 43 remains constant, stabilizing the movement of the CIS unit 43 in the sub-scanning direction X.

[0037] Conversely, when the CIS unit 43 is moved from near the rear end of the platen glass 41 to near the front end, the bent portion of the slider 53 also moves from near the rear end to near the front end of the platen glass 41. Furthermore, the motor 56 rotates the roller 55 in the forward direction, the roller 55 gradually winds up the string-like member 54 while adjusting the amount of string-like member 54 wound up by the roller 55, the ring 54A of the string-like member 54 pulls the slider 53 and moves it in the reverse direction along the FFC 51, the slider 53 gradually approaches the CIS unit 43, the portion of the FFC 51 from the slider 53 to the CIS unit 43 gradually shortens, the slider 53 continues to pull the bent portion of the FFC 51, change in the bent state of the FFC 51 is suppressed, the FFC 51 does not approach the rear surface of the platen glass 41, and the load on the CIS unit 43 does not fluctuate.

[0038] Fig. 11 is a block diagram showing the internal configuration of the image reading device 11. As shown in Fig. 11, the image reading device 11 includes a CIS unit 43, a motor 48 that moves the CIS unit 43 in the sub-scanning direction X, a motor 56 that rotates a roller 55, a sensor 61 that detects the home position of the CIS unit 43 near the leading edge of the platen glass 41, a display unit 62, and a control unit 63 that drives and controls the motors 48 and 56.

[0039] The control unit 63 includes a processor, a RAM (Random Access Memory), a ROM (Read Only Memory), and a dedicated hardware circuit. The processor is, for example, a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or an MPU (Micro Processing Unit). The control unit 63 may also function as a control device that controls the overall operation of the image forming apparatus 1.

[0040] Each of the motors 48, 56 is, for example, a stepping motor. The control unit 63 controls the rotation direction and rotation angle of the motor 48 to rotate the pulley 46 and move the endless belt 47 in a circular motion, thereby adjusting the movement position of the CIS unit 43 in the sub-scanning direction X. The control unit 63 also controls the rotation direction and rotation angle of the motor 56 to rotate the roller 55 forward or reverse, adjusting the amount of the string-like member 54 taken up and fed by the roller 55, and causing the ring 54A of the string-like member 54 to pull the slider 53, changing the engagement position of the slider 53 with respect to the FFC 51 and suppressing changes in the bending state of the FFC 51.

[0041] That is, when the CIS unit 43 moves in a first direction in the sub-scanning direction in which the portion of the FFC 51 from the slider 53 to the CIS unit 43 (CIS) is extended, the control unit 63 rotates the motor 56 in a direction in which the roller 55 feeds out the string-like member 54. Furthermore, when the CIS unit 43 moves in a second direction in the sub-scanning direction in which the portion of the FFC 51 from the slider 53 to the CIS unit 43 (CIS) is shortened, the control unit 63 rotates the motor 56 in a direction in which the roller 55 winds up the string-like member 54.

[0042] The amount of winding and feeding of the string-like member 54 by the roller 55 is set according to the movement position of the CIS unit 43 in the sub-scanning direction X, and the relationship between the amount of winding and feeding of the string-like member 54 and the movement position of the CIS unit 43 is set in advance. The control unit 63 controls the rotation direction and rotation angle of the motor 48 to adjust the movement position of the CIS unit 43 in the sub-scanning direction X and controls the rotation direction and rotation angle of the motor 56 to set the amount of winding and feeding of the string-like member 54 according to this movement position. That is, when the control unit 63 controls the rotation direction and rotation angle of the motor 48 to move the CIS unit 43 in the first direction in the sub-scanning direction, the string-like member 54 applies tension to the FFC 51, and the engagement position of the slider 53 with respect to the FFC 51 changes due to this tension. As a result, the bent portion of the FFC 51 is constantly pulled by the slider 53, suppressing changes in the bent state of the FFC 51.

[0043] 12 is a flowchart showing a control procedure of the image reading device 11 by the control unit 63. In the flowchart shown in FIG. 12, the control unit 63 aligns the phases of the motors 48, 56 (S101). For example, sensors are provided to detect the rotation angles of the motors 48, 56. The control unit 63 controls the rotation angles of the motors 48, 56, compares the rotation angles obtained by this control with the rotation angles detected by the sensors, and aligns the phases of the motors 48, 56.

[0044] The control unit 63 determines whether the phases of the motors 48, 56 have been aligned (S102), and if it determines that the phases have not been aligned (S102 "No"), it displays an error message on the display unit 62 (S103). In this case, maintenance of the image reading device 11 by a service technician or the like is required.

[0045] Furthermore, when the control unit 63 determines that phase alignment has been achieved (S102 "Yes"), it controls the drive of each motor 48, 56 while synchronizing them, and causes the motor 48 to move the CIS unit 43 to the home position (e.g., the position of the shading correction plate) based on the detection output of the sensor 61 (S104).

[0046] The control unit 63 synchronizes and controls the drive of the motors 48 and 56, causing the motor 48 to move the CIS unit 43 from the home position to a reading start position near the leading edge of the platen glass 41 (S105), and simultaneously causes the motor 56 to rotate the roller 55 in the forward direction, increasing the amount of string-like member 54 wound around the roller 55 and causing the slider 53 to pull the FFC 51 (S106). As a result, as shown in Figures 4(A) and 4(B), the slider 53 moves along the FFC 51 toward the CIS unit 43, causing the FFC 51 to bend in a small arc and undergo elastic deformation.

[0047] The control unit 63 synchronizes and controls the drive of the motors 48 and 56, causes the motor 48 to move the CIS unit 43 from the reading start position to near the rear end of the platen glass 41, and causes the CIS unit 43 to read the image of the document on the platen glass 41 (S107). At the same time, the control unit 63 causes the motor 56 to rotate the roller 55 in the reverse direction, gradually feeding the string-like member 54 from the roller 55 while restricting the amount of string-like member 54 fed from the roller 55, and causes the slider 53 to pull the FFC 51 (S108). At this time, as shown in Figures 3(A), (B), 9(A), (B), and 10, the slider 53 moves along the FFC 51 and separates from the CIS unit 43, and the portion of the FFC 51 from the slider 53 to the CIS unit 43 becomes longer, but because the FFC 51 is always pulled by the slider 53, changes in the bending state of the FFC 51 are suppressed.

[0048] The control unit 63 controls the drive of the motors 48, 56 while synchronizing them, and causes the motor 48 to move the CIS unit 43 near the rear end of the platen glass 41, thereby completing the reading of the image of the original by the CIS unit 43 (S109). Then, the control unit 63 controls the drive of the motors 48, 56 while synchronizing them, and causes the motor 48 to move the CIS unit 43 to the home position (S110). At the same time, the control unit 63 causes the motor 56 to rotate the roller 55 in the forward direction, causing the roller 55 to gradually wind up the string-like member 54, while adjusting the amount of string-like member 54 wound up by the roller 55, and moves the slider 53 in the reverse direction along the FFC 51 to approach the CIS unit 43. The slider 53 constantly pulls the FFC 51, thereby suppressing changes in the bending state of the FFC 51 (S111).

[0049] As described above, in this embodiment, as the CIS unit 43 moves in the sub-scanning direction X, the motor 56 rotates the roller 55 back and forth, causing the roller 55 to wind up and feed out the string-like member 54, and the string-like member 54 constantly pulls the slider 53. This suppresses changes in the bending state of the FFC 51, making it possible to prevent the FFC 51 from coming into contact with the rear surface of the platen glass 41, and also suppresses fluctuations in the load on the CIS unit 43, stabilizing the movement of the CIS unit 43 in the sub-scanning direction X.

[0050] Therefore, according to this embodiment, when the CIS is moved in the sub-scanning direction, changes in the bending state of the FFC 51 connected to the CIS are suppressed, and the CIS can be moved smoothly in the sub-scanning direction.

[0051] The configurations and processes of the above-described embodiment explained with reference to FIGS. 1 to 12 are merely examples of the present invention, and the present invention is not limited to these configurations and processes. [Explanation of symbols]

[0052] 10 Image forming device 11 Image reading device 12 Image forming unit 41 Platen Glass 43 CIS Unit 48 Motor 51 FFC 53 Slider 54 String-like member 55 Roller 56 Motor 57 Guide section 61 Sensors 62 Display section 63 Control Unit

Claims

1. An image reading device, an image pickup element that extends in a main scanning direction and moves in a sub-scanning direction perpendicular to the main scanning direction below the platen glass to repeatedly read an image of an original placed on the platen glass at each position in the sub-scanning direction; a flexible flat cable having one end connected to the image sensor, folded back and bent in the sub-scanning direction below the image sensor, and the other end attached to the bottom of a housing of the image reading device; a slider engaged with the flexible flat cable so as to be movable in the longitudinal direction of the flexible flat cable; a string-like member connected to the slider; a roller for winding and feeding the string-like member; a first motor that rotates the roller.

2. when the imaging element moves in a sub-scanning direction in a first direction in which the portion of the flexible flat cable from the slider to the imaging element is extended, the first motor is rotated in a direction in which the roller feeds out the string-like member; 2. The image reading device of claim 1, further comprising a control unit that rotates the first motor in a direction in which the roller winds up the string-like member when the imaging element moves in a second direction in the sub-scanning direction to shorten the portion of the flexible flat cable from the slider to the imaging element.

3. a second motor that moves the imaging element in a sub-scanning direction; The image reading device according to claim 2 , wherein the control unit controls a rotation direction and a rotation angle of the second motor to move the imaging element in the first direction and the second direction in a sub-scanning direction.

4. 3. The image reading device of claim 2, wherein when the control unit controls the direction and angle of rotation of the second motor to move the imaging element in the first direction in the sub-scanning direction, the string-like member applies tension to the flexible flat cable, and the tension changes the engagement position of the slider with respect to the flexible flat cable.

5. 2. The image reading device according to claim 1, further comprising a guide portion that supports the slider so that the slider is movable along the sub-scanning direction.

6. An image reading device according to any one of claims 1 to 5; an image forming unit that forms the image read and extracted by the image reading device on a recording sheet;

Images