Image reading device and abnormality detection method

Abstract

To provide an image reading device and an abnormality detection method, capable of detecting an abnormal state including a change in the shape of an FFC.SOLUTION: In the image reading part (11) of the image reading device, the change processing part (41) of a control part (4) changes the logic of a driving signal transmitted by a light source line at a change timing when the position of an image reading object by an imaging part becomes a preset specific position in a second direction perpendicular to a first direction on a document placing surface, in such a state that a reading unit (22) is stopped. A detection processing part (42) detects the presence or absence of the abnormality of a flexible flat cable (30) on the basis of the change timing of the logic of the driving signal by the change processing part (41) and a reading signal output from the imaging part (222) at the change timing.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an image reading device having a reading unit connected to a flat cable. [Background technology]

[0002] In some image reading devices, a reading unit including an imaging unit such as a CIS moves back and forth along the rear surface of a contact member. A flexible flat cable (hereinafter abbreviated as "FFC") is connected to the reading unit, and data communication is performed between the reading unit and a control unit via the FFC (see, for example, Patent Document 1).

[0003] Incidentally, FFCs include not only data lines that transmit signals of scanned data from the imaging unit but also light source lines that transmit drive signals for the light sources of the scanning unit. For example, the light source lines may transmit signals with higher voltages than the data lines. Therefore, crosstalk noise caused by the proximity or parallel running of the data lines and the light source lines may affect the signals transmitted through the data lines. To address this issue, the order of the data lines and the light source lines in the FFC or the curved shape of the FFC may be designed to avoid the proximity or parallel running of the data lines and the light source lines. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-161538 Summary of the Invention [Problem to be solved by the invention]

[0005] In an image reading device, the shape of the FFC may change due to aging or friction caused by movement of the reading unit, etc. If the shape of the FFC changes, the data line and the light source line may come close to each other or run parallel to each other, which may continue to affect data communication on the data line.

[0006] An object of the present invention is to provide an image reading device and an abnormality detection method that are capable of detecting abnormal conditions including changes in the shape of an FFC. [Means for solving the problem]

[0007] According to one aspect of the present invention, an image reading device includes a reading unit, a control unit, a flexible flat cable, a change processing unit, and a detection processing unit. The reading unit includes an imaging unit and a light source, and is movable in a first direction on a document placement surface on which a document to be read is placed. The control unit acquires a read signal output from the imaging unit of the reading unit. The flexible flat cable connects the reading unit and the control unit, and includes at least a data line transmitting the read signal output from the imaging unit and a light source line transmitting a drive signal for the light source. The flexible flat cable is accommodated in a curved state within the housing. The change processing unit, when the reading unit is stopped, changes the logic of the drive signal transmitted through the light source line at a change timing at which the position of the image reading target by the imaging unit reaches a predetermined specific position in a second direction perpendicular to the first direction on the document placement surface. The detection processing unit detects whether or not there is an abnormality in the flexible flat cable based on the change timing and the read signal output from the imaging unit at the change timing.

[0008] According to another aspect of the present invention, an abnormality detection method is a method in which the control unit of an image reading device executes a first step and a second step. The image reading device includes a reading unit, a control unit, and a flexible flat cable. The reading unit includes an imaging unit and a light source, and is movable in a first direction on a document placement surface on which a document to be read is placed. The control unit acquires a read signal output from the imaging unit of the reading unit. The flexible flat cable connects the reading unit and the control unit, includes at least a data line for transmitting the read signal output from the imaging unit and a light source line for transmitting a drive signal for the light source, and is accommodated in a curved state within the housing. The first step changes logic of the drive signal transmitted through the light source line at a change timing when, while the reading unit is stopped, the position of the image reading target by the imaging unit reaches a predetermined specific position in a second direction perpendicular to the first direction on the document placement surface. The second step detects the presence or absence of an abnormality in the flexible flat cable based on the change timing and the read signal output from the imaging unit at the change timing. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an image reading device and an abnormality detection method that are capable of detecting abnormal conditions including changes in the shape of an FFC. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view showing an image reading apparatus including an image reading device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing the configuration of the image reading device. [Figure 3] FIG. 3 is a flowchart showing an example of an abnormality detection control process executed in the image reading device. [Figure 4] FIG. 4 is a diagram for explaining the contents of the abnormality detection control process executed in the image reading device. [Figure 5]FIG. 5 is a diagram for explaining the contents of the abnormality detection control process executed in the image reading device. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is merely an example of the present invention and does not limit the technical scope of the present invention.

[0012] The schematic configuration of an image reading device 10 according to an embodiment of the present invention will be described with reference to FIGS.

[0013] The image reading device 10 is a multifunction peripheral having an image reading function, a facsimile function, an image forming function, and the like. As shown in FIG. 1, the image reading device 10 includes an image reading unit 11, an automatic document feeder (hereinafter referred to as an ADF) 13, an image forming unit 15, an operation display unit 16, a paper feed cassette 17, a paper discharge unit 18, and a control unit 4 (see FIG. 2). Note that, in this embodiment, the image reading device 10 including the image reading unit 11 is described as an example, but the present invention is not limited thereto. For example, the present invention may also be applicable to an image reading unit 11 independent from the image reading device 10, or to a facsimile machine or a copier including the image reading unit 11.

[0014] The control unit 4 includes processing elements such as a CPU, a ROM, and a RAM. In the control unit 4, the CPU executes various processes in accordance with programs stored in the ROM, thereby providing overall control of the image reading device 10. For example, the control unit 4 acquires a read signal read from a document to be read by the image reading unit 11, and performs an image reading process that generates image data based on the read signal. In another embodiment, the image reading device 10 may include a main control unit that performs overall control of the image reading device 10, and a control unit 4 that controls the image reading unit 11, separately.

[0015] Image forming unit 15 performs color or monochrome image formation (printing) according to an electrophotographic method based on image data read by image reading unit 11 or image data input from an external information processing device such as a personal computer. Image forming unit 15 includes an image forming unit, an exposure device, an intermediate transfer belt, a secondary transfer roller, a fixing device, etc. The image forming unit includes a photosensitive drum, a charging device, a developing device, a primary transfer roller, a cleaning device (none of which are shown), etc. These components are provided in a housing that forms the frame of image forming unit 15. Note that, although the present embodiment will be described using an electrophotographic image forming unit 15 as an example, image forming unit 15 is not limited to an electrophotographic type and may be an inkjet recording type or any other recording or printing type.

[0016] The ADF 13 is provided in the image reading unit 11. The ADF 13 picks up documents placed in the document setting unit 13A one by one and transports them continuously to a predetermined reading position. Here, the reading position is a position where the image of the document can be read by the image reading unit 11 and is a position where light is irradiated by a reading unit 22, which will be described later. The ADF 13 is also provided with a pressing member 14 that is biased toward a contact member 28, which will be described later, and presses the document being transported against the contact member 28. The surface of the pressing member 14 facing the contact member 28 is a white portion that is used to read a white reference value in the reading gradation correction process of the image reading unit 11, etc.

[0017] The image reading unit 11 is mounted on the top of the image reading device 10. The image reading unit 11 reads image data from a document. As shown in FIG. 2, the image reading unit 11 includes a reading unit 22, a contact member 27, a contact member 28, a document presser 29, and a housing 21. These components are housed inside the housing 21 of the image reading unit 11. The surface of the presser 29 facing the contact member 27 may be a white portion used to read a white reference value in the reading gradation correction process of the image reading unit 11, etc.

[0018] Both contact member 27 and contact member 28 are attached to the upper part of housing 21. Contact member 27 is a portion on which a document to be read from is placed, and is a document placement surface held horizontally by housing 21. Contact member 28 is a portion that transmits light irradiated from reading unit 22 onto a document transported by ADF 13, and is held horizontally by housing 21. Contact members 27 and 28 are formed in a flat plate shape from a transparent material (such as glass or transparent resin).

[0019] The contact members 28 are transparent, plate-shaped members that are long in the main scanning direction (the front-rear direction in FIG. 1, an example of the second direction). The contact members 28 are also formed in a narrow shape in the sub-scanning direction (a direction perpendicular to the main scanning direction, an example of the first direction).

[0020] 2, the reading unit 22 is a device that reads an image of a document transported by the ADF 13 or an image of a document placed on the contact member 27. The reading unit 22 includes a light source 221, an imaging unit 222, a carriage 23, and the like. These optical members are housed in the carriage 23 that constitutes the housing of the reading unit 22. The imaging unit 222 is a CIS (Contact Image Sensor) that includes a plurality of imaging elements aligned in the main scanning direction.

[0021] The carriage 23 of the reading unit 22 is configured to be reciprocally movable in the left-right direction (first direction) of the contact member 27 by a conventionally known movement mechanism using a drive device such as a stepping motor. In this embodiment, the carriage 23 is configured to be reciprocally movable from a start position P1 to an end position P2 of the operation of reading an image of a document placed on the contact member 27. This allows the reading unit 22 to reciprocate between the start position P1 and the end position P2. Here, the start position P1 is a position below the left edge of the document placed on the contact member 27. The end position P2 is a position (indicated by a dashed line in FIG. 2) separated to the right from the start position P1 by the maximum reading range. In this embodiment, the end position P2 is determined near the right side wall 21B of the housing 21.

[0022] The movement mechanism may be a belt transmission mechanism or a gear transmission mechanism that transmits driving force from a motor to the carriage 23. In the image reading section 11, an original is placed on the contact member 27, and with the original presser foot 29 closed, the reading unit 22 is moved back and forth in the left-right direction by the drive device within the housing 21 relative to the original. Then, while the reading unit 22 is moving rightward, light irradiated from a light source 221 such as an LED onto the contact member 27 is scanned, and the reflected light is received by the imaging section 222, thereby reading the image of the original.

[0023] A flexible flat cable (hereinafter abbreviated as "FFC") 30 is provided inside the housing 21. The FFC 30 electrically connects the reading unit 22 and the control unit 4, and its internal conductors are covered with insulating resin. One end of the FFC 30 is electrically connected to the reading unit 22, and the other end is connected to the fixing part 24. The fixing part 24 is provided on the bottom surface 21A of the housing 21, and fixes the other end of the FFC 30 to the bottom surface 21A. The fixing part 24 also electrically connects the other end of the FFC 30 to the control unit 4 directly or via another cable.

[0024] In this embodiment, the fixing part 24 fixes the FFC 30 to the bottom surface 21A in a curved state from the fixing part 24 to the reading unit 22. That is, one end of the FFC 30 is connected to the reading unit 22 via the connector 32, and a predetermined portion from the one end to the other end is fixed to the bottom surface 21A by the fixing part 24. The other end of the FFC 30 is connected to the control unit 4 via the connector 33. As a result, the FFC 30 from the fixing part 24 to the reading unit 22 is accommodated inside the housing 21 in a curved state so that the FFC 30 follows the reciprocating movement of the carriage 23.

[0025] The FFC 30 includes a data line transmitting a read signal output from the imaging unit 222, a power line, a light source line, and the like. The power line is used to supply power to the reading unit 22. The light source line is used to transmit a drive signal for controlling the driving (illumination) of the light source 221. The light source line may transmit a drive signal with a higher voltage than the data line. For example, even if the read signal transmitted through the data line is approximately 1 V peak-to-peak, the drive signal transmitted through the light source line may be 10 V peak-to-peak or higher. Therefore, crosstalk noise caused by the proximity or parallel running of the data line and the light source line may affect the read signal transmitted through the data line. To address this issue, the arrangement or curved shape of the data line and the light source line in the FFC 30 may be designed to avoid the proximity or parallel running of the data line and the light source line.

[0026] In the image reading unit 11, the shape of the FFC 30 may change due to aging or friction caused by movement of the reading unit 22. If the shape of the FFC 30 changes, the data line and the light source line may come close to each other or run parallel to each other, which may continue to affect data communication on the data line. In response to this, the image reading unit 11 according to this embodiment is capable of detecting the shape change of the FFC 30.

[0027] Specifically, the control unit 4 includes a change processing unit 41 and a detection processing unit 42. The control unit 4 executes processing in accordance with the program to function as the change processing unit 41 and the detection processing unit 42. Note that either or both of the change processing unit 41 and the detection processing unit 42 may be an electric circuit such as an ASIC.

[0028] When the reading unit 22 is stopped, the change processing unit 41 changes the logic of the drive signal transmitted through the light source line at a change timing when the position of the image reading target by the imaging unit 222 becomes a predetermined specific position in the front-to-back direction (second direction) perpendicular to the left-to-right direction (first direction) on the contact member 27, which is the document placement surface.

[0029] In this embodiment, when the logic of the drive signal is "L," current flows through the light source 211, turning the light source 211 on, and when the logic of the drive signal is "L," no current is supplied to the light source 211, turning the light source 211 off. Note that in this embodiment, the drive signal is a digital signal that is "H" when it is 10 V and "L" when it is 0 V. The change processing unit 41 changes the logic of the drive signal transmitted from the reading unit 22 through the light source line between "H" and "L." As a result, the voltage of the drive signal transmitted through the light source line of the FFC 30 changes between 10 V and 0 V.

[0030] The detection processing unit 42 detects whether or not there is an abnormality in the FFC 30 based on the timing at which the logic of the drive signal is changed by the change processing unit 41 and the read signal output from the imaging unit 222 at the change timing. In particular, the detection processing unit 42 detects whether or not there is an abnormality in the FFC 30 by using one or both of two different detection methods.

[0031] Specifically, the detection processing unit 42 detects that there is an abnormality in the FFC 30 when a change of a predetermined specific value or more occurs in the voltage value of the read signal, and the specific timing at which the change of the predetermined specific value or more occurs and the change timing satisfy a predetermined first detection condition.

[0032] [Anomaly detection control processing] 3, the abnormality detection control process executed by the control unit 4 in the image reading device 10 will be described. Note that the present invention may also be understood as an invention of an abnormality detection method that detects an abnormality in the FFC 30 by executing various processes in the abnormality detection control process.

[0033] <Step S11> In step S11, the control unit 4 determines whether or not it is necessary to detect the presence or absence of an abnormality in the FFC 30. For example, the control unit 4 determines that it is necessary to detect the presence or absence of an abnormality in the FFC 30 every time a preset period of time has elapsed. The control unit 4 may also determine that it is necessary to detect the presence or absence of an abnormality in the FFC 30 in response to a user operation. Furthermore, the control unit 4 may also determine that it is necessary to detect the presence or absence of an abnormality in the FFC 30 when the image reading process by the image reading unit 11 starts.

[0034] If it is determined that it is necessary to detect whether or not there is an abnormality in the FFC 30 (S11: Yes), the process proceeds to step S12, and while it is determined that it is not necessary to detect whether or not there is an abnormality in the FFC 30 (S11: No), the process waits in step S11.

[0035] <Step S12> In step S12, the control unit 4 controls the image reading unit 11 to start a predetermined anomaly detection scan. Specifically, in the anomaly detection scan, the reading unit 22 performs an image reading process while the reading unit 22 is stopped at a predetermined detection position. In the image reading process, the light source 221 is turned on, and the imaging unit 222 sequentially outputs a read signal corresponding to each pixel position in the main scanning direction. The detection position may be a predetermined home position of the reading unit 22, or a predetermined position below the contact member 27 or the contact member 28. In this embodiment, the detection position is a position where the reading position of the reading unit 22 is the presser member 14. Therefore, the value of the read signal output from the imaging unit 222 is 255, which corresponds to the white color from the white portion of the presser member 14. In the anomaly detection scan, the image reading process is performed for one or more predetermined lines in the sub-scanning direction.

[0036] <Step S13> In step S13, the control unit 4 determines whether the abnormality detection scan started in step S12 has ended. If it is determined that the abnormality detection scan has ended (S13: Yes), the process proceeds to step S18, and if it is determined that the abnormality detection scan has not ended (S13: No), the process proceeds to step S14.

[0037] <Step S14> In step S14, the change processing unit 41 of the control unit 4 determines whether the position to be read in the main scanning direction by the imaging unit 222 of the reading unit 22 has reached a preset first change timing t1 (see FIG. 4). FIG. 4 is a diagram showing an example of the read signal for one line by the imaging unit 222 and the drive signal when the read signal is read. If it is determined that the position to be read has reached the first change timing t1 (S14: Yes), the process proceeds to step S15. If it is determined that the position to be read has not reached the first change timing t1 (S14: No), the process proceeds to step S16.

[0038] <Step S15> In step S15, the change processing unit 41 of the control unit 4 changes the logic of the drive signal output from the light source 221 provided in the imaging unit 222 of the reading unit 22 and transmitted through the light source line, and the process returns to step S13. Specifically, since the drive signal is "H" when the image reading process is executed, in step S15, as shown in FIG. 4, the change processing unit 41 of the control unit 4 changes the logic of the drive signal from "H" of 10V to "L" of 0V. That is, the change processing unit 41 of the control unit 4 turns on the light source 221 at a first change timing t1. Note that the first change timing t1 may be the same as or different from the timing at which the light source 221 is turned on in a normal image reading process in which an image is read from a document in the image reading device 10.

[0039] <Step S16> In step S16, the change processing unit 41 of the control unit 4 determines whether the position to be read in the main scanning direction by the imaging unit 222 of the reading unit 22 has reached a preset second change timing t2 (see FIG. 4). If it is determined that the position to be read has reached the second change timing t2 (S16: Yes), the process proceeds to step S17, and if it is determined that the position to be read has not reached the second change timing t2 (S16: No), the process returns to step S13.

[0040] <Step S17> In step S17, the change processing unit 41 of the control unit 4 restores the logic of the drive signal changed in step S15, and the process returns to step S13. Specifically, if the drive signal is changed to "L" in step S15, in step S17, the control unit 4 changes the logic of the drive signal from "L" of 0V to "H" of 10V, as shown in FIG. 4. That is, the change processing unit 41 of the control unit 4 turns off the light source 221 at the second change timing t2. Note that the second change timing t2 may be the same as or different from the timing at which the light source 221 is turned off in a normal image reading process in which the image reading device 10 reads an image from a document.

[0041] <Step S18> On the other hand, if it is determined that the abnormality detection scan has ended, then in step S18, the detection processing section 42 of the control section 4 determines whether or not there is an abnormality in the FFC 30 based on the reading result of the abnormality detection scan.

[0042] In this embodiment, the detection processing unit 42 compares the read signals of the multiple lines read by the abnormality detection scan to determine whether there is a specific timing at which the voltage value of the read signal changes by more than a predetermined specific value. If the detection processing unit 42 determines that there is no specific timing at which the voltage value of the read signal changes by more than the specific value, it determines that no abnormality has occurred in the FFC 30.

[0043] On the other hand, if an abnormality occurs in the FFC 30, as shown in FIG. 4, noises P1 and P2 appear in the read signal at the first change timing t1 and the second change timing t2, indicating that the voltage value of the read signal changes by the specific value or more. Therefore, when the detection processing unit 42 determines that there is a specific timing at which the voltage value changes by the specific value or more, it determines whether the specific timing satisfies a predetermined detection condition in relation to the first change timing t1 or the second change timing t2. Specifically, the detection condition is that the specific timing and the first change timing t1 or the second change timing t2 exist within a predetermined specific period. The specific period is a period that is preset to determine that the voltage value has changed by the specific value or more due to a change in the logic of the drive signal. Specifically, the specific period is determined to be a period in which it can be determined that the specific timing and the first change timing t1 or the second change timing t2 are approximately the same timing. The detection processor 42 then determines that an abnormality has occurred in the FFC 30 if it determines that the specific timing and the first change timing t1 or the second change timing t2 are within the specific period. That is, the detection processor 42 detects an abnormality in the FFC 30 when a detection condition is met: the voltage value of the read signal changes by a predetermined value or more, and the specific timing and the change timing are within the specific period. The detection processor 42 may also detect an abnormality in the FFC 30 based on the relationship between the specific timing at which the voltage value of the read signal changes by the specified value or more within one line of the read signal and the first change timing t1 or the second change timing t1. Furthermore, the detection processor 42 changes the logic of the drive signal (first change timing t1) and restores it (second change timing t2). However, the change in the logic of the drive signal may be performed only once.

[0044] <Step S19> In step S19, the control unit 4 notifies the result of the determination in step S18. For example, if the control unit 4 determines in step S18 that an abnormality has occurred in the FFC 30, it causes a message or an error code corresponding to the abnormality to be displayed on the operation / display unit 16. Furthermore, if the control unit 4 determines in step S18 that an abnormality has occurred in the FFC 30, it may transmit information indicating that an abnormality has occurred in the FFC 30 to a preset notification destination.

[0045] As described above, in the image reading device 10, the abnormality detection control process is executed, and thus it is possible to detect an abnormal state, including a change in the shape of the FFC 30, based on the timing of the change in the logic of the drive signal and the read signal. This allows the user to, for example, recognize the abnormal state of the FFC 30 and attempt to recover from the abnormal state, thereby preventing a deterioration in the quality of the image read by the image reading unit 11.

[0046] [Other embodiments] In the above embodiment, a method for detecting an abnormality in the FFC 30 based on a change in the voltage value of the read signal has been described. Meanwhile, in another embodiment, an abnormality in the FFC 30 may be detected based on a read image represented by image data generated based on the read signals for a predetermined number of lines, such as one page or multiple pages. In this case, in the abnormality detection control process, the control unit 4 repeatedly executes steps S13 to S17 until the read signals corresponding to the predetermined number of lines are read. Furthermore, reading of the read signals corresponding to the plurality of lines may be executed while the carriage 23 on the contact member 27 moves left and right (first direction), similar to a normal image reading process in which the image reading device 10 reads an image from a document. Note that FIG. 5 is a diagram illustrating an example of the read signals for one page by the imaging unit 222 and the read image represented by image data generated based on the read signals.

[0047] The detection processing unit 42 then detects an abnormality in the FFC 30 when the scanned image represented by the image data generated based on the scanning signal includes a line image in the sub-scanning direction corresponding to the movement direction of the scanning unit, and when the position of the line image in the main scanning direction perpendicular to the sub-scanning direction and the position in the main scanning direction corresponding to the change timing satisfy a second detection condition that is set in advance. The second detection condition is that the position of the line image in the main scanning direction and the position corresponding to the change timing are within a specific range.

[0048] Specifically, in step S18, the detection processing unit 42 generates image data based on the read signals of the multiple lines read by the abnormality detection scan. The detection processing unit 42 then determines whether or not a line image, such as a black streak in the sub-scanning direction, exists in the read image represented by the image data. If the detection processing unit 42 determines that no line image exists in the read image, it determines that no abnormality has occurred in the FFC 30.

[0049] On the other hand, if an abnormality occurs in the FFC 30, line images such as line images BL1 and BL2 appear in the scanned image at the scanning target positions corresponding to the first change timing t1 and the second change timing t2, as shown in FIG. 5. Therefore, when the detection processing unit 42 determines that the line images exist in the scanned image, it first determines whether the positions of the line images BL1 and BL2 in the sub-scanning direction satisfy a predetermined detection condition in relation to the scanning target positions in the sub-scanning direction corresponding to the first change timing t1 and the second change timing t2. Specifically, the detection condition is that the positions of the line images BL1 and BL2 in the sub-scanning direction and the scanning target positions in the sub-scanning direction corresponding to the first change timing t1 and the second change timing t2 are within a predetermined specific range. The specific range is a range that is preset to identify that a line image has appeared in the scanned image due to a change in the logic of the drive signal. Specifically, the specific range is defined as a range in which it is possible to determine that the position of the line image in the sub-scanning direction and the read target positions corresponding to the first change timing t1 and the second change timing t2 are approximately the same. The detection processing unit 42 determines that an abnormality has occurred in the FFC 30 when it determines that the position of the line image in the sub-scanning direction and the positions corresponding to the first change timing t1 and the second change timing t2 are within the specific range. That is, the detection processing unit 42 detects an abnormality in the flexible flat cable when the read image represented by the image data generated based on the read signal includes a line image in the sub-scanning direction corresponding to the movement direction of the reading unit, and the position of the line image in the main scanning direction perpendicular to the sub-scanning direction and the read target positions corresponding to the change timings in the main scanning direction satisfy a predetermined second detection condition.

[0050] [Notes on the Invention] The following will provide an outline of the invention extracted from the above-described embodiment. Note that the configurations and processing functions described in the following supplementary notes can be selected and combined as desired.

[0051] <Appendix 1> a reading unit including an imaging unit and a light source, and arranged to be movable in a first direction on a document placement surface on which a document to be read is placed; a control unit that acquires a read signal output from the imaging unit of the reading unit; a flexible flat cable that connects the reading unit and the control unit, includes at least a data line that transmits a reading signal output from the imaging unit and a light source line that transmits a drive signal for the light source, and is accommodated in a curved state within the housing; a change processing unit that changes the logic of the drive signal transmitted through the light source line at a change timing when a position of an image reading target by the imaging unit becomes a predetermined specific position in a second direction perpendicular to the first direction on the document placement surface while the reading unit is stopped; a detection processing unit that detects whether or not there is an abnormality in the flexible flat cable based on the change timing and the read signal output from the imaging unit at the change timing; An image reading device comprising:

[0052] <Appendix 2> the detection processing unit detects that there is an abnormality in the flexible flat cable when a change of a predetermined specific value or more occurs in the voltage value of the read signal, and the specific timing at which the change of the predetermined value or more occurs and the change timing satisfy a predetermined first detection condition. 2. An image reading device according to claim 1.

[0053] <Appendix 3> the first detection condition is that the specific timing and the change timing are within a specific period of time; 2. An image reading device according to claim 1.

[0054] <Appendix 4> the detection processing unit detects that there is an abnormality in the flexible flat cable when a read image indicated by image data generated based on the read signal includes a line image in a sub-scanning direction corresponding to the movement direction of the reading unit, and when a position of the line image in a main scanning direction perpendicular to the sub-scanning direction and a position in the main scanning direction corresponding to the change timing satisfy a second detection condition set in advance. 4. The image reading device according to any one of claims 1 to 3.

[0055] <Appendix 5> the second detection condition is that the position of the line image in the main scanning direction and the position corresponding to the change timing are within a specific range. 5. The image reading device according to claim 4.

[0056] <Appendix 6> a control unit that acquires a read signal output from the imaging unit of the reading unit; and a flexible flat cable that connects the reading unit and the control unit and includes at least a data line that transmits the read signal output from the imaging unit and a light source line that transmits a drive signal for the light source, the control unit of an image reading device being accommodated in a curved state within the housing. a first step of changing the logic of the drive signal transmitted through the light source line at a change timing when a position of an image reading target by the imaging unit becomes a predetermined specific position in a second direction perpendicular to the first direction on the document placement surface while the reading unit is stopped; a second step of detecting whether or not there is an abnormality in the flexible flat cable based on the timing of the change in logic of the drive signal in the first step and the read signal output from the imaging unit at the change timing; Anomaly detection methods that perform. [Explanation of symbols]

[0057] 10 Image reader 11 Image reading device 21. Cabinet 22 Reading unit 221 Light source 222 Imaging unit 27 Contact material 30 FFC 4. Control section 41 Change processing section 42 Detection processing section

Claims

1. a reading unit including an imaging unit and a light source, and disposed so as to be movable in a first direction on a document placement surface on which a document to be read is placed; a control unit that acquires a read signal output from the imaging unit of the reading unit; a flexible flat cable that connects the reading unit and the control unit, includes at least a data line that transmits a reading signal output from the imaging unit and a light source line that transmits a drive signal for the light source, and is accommodated in a curved state within the housing; a change processing unit that changes the logic of the drive signal transmitted through the light source line at a change timing when a position of an image reading target by the imaging unit reaches a predetermined specific position in a second direction perpendicular to the first direction on the document placement surface while the reading unit is stopped; a detection processing unit that detects whether or not there is an abnormality in the flexible flat cable based on the change timing and the read signal output from the imaging unit at the change timing; An image reading device comprising:

2. the detection processing unit detects that there is an abnormality in the flexible flat cable when a change of a predetermined specific value or more occurs in the voltage value of the read signal, and the specific timing at which the change of the predetermined value or more occurs and the change timing satisfy a predetermined first detection condition.

2. The image reading device according to claim 1.

3. the first detection condition is that the specific timing and the change timing are within a specific period of time; 3. The image reading device according to claim 2.

4. the detection processing unit detects that there is an abnormality in the flexible flat cable when a read image indicated by image data generated based on the read signal includes a line image in a sub-scanning direction corresponding to the movement direction of the reading unit, and when a position of the line image in a main scanning direction perpendicular to the sub-scanning direction and a position in the main scanning direction corresponding to the change timing satisfy a second detection condition set in advance.

4. The image reading device according to claim 1.

5. the second detection condition is that a position of the line image in the main scanning direction and a position corresponding to the change timing are within a specific range.

5. The image reading device according to claim 4.

6. a control unit that acquires a read signal output from the imaging unit of the reading unit; and a flexible flat cable that connects the reading unit and the control unit and includes at least a data line that transmits the read signal output from the imaging unit and a light source line that transmits a drive signal for the light source, the control unit of an image reading device being accommodated in a curved state within the housing. a first step of changing logic of the drive signal transmitted through the light source line at a change timing when a position of an image reading target by the imaging unit becomes a predetermined specific position in a second direction perpendicular to the first direction on the document placement surface while the reading unit is stopped; a second step of detecting whether or not there is an abnormality in the flexible flat cable based on the change timing and the read signal output from the imaging unit at the change timing; Anomaly detection methods that perform.

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