Image forming system and information processing device

Abstract

The present invention provides an image forming apparatus (image forming system) that can detect when recording material is not being transported correctly. [Solution] The image forming apparatus includes a transport sensor positioned downstream of the sheet separation unit in the sheet (recording material) transport direction and capable of detecting the sheet being transported, and a sheet separation unit equipped with a separation contact unit that contacts the sheet fed by the paper feeding unit. The sheet separation unit separates the recording material into individual sheets and transports them. Based on the detection result from the transport sensor, the control unit determines whether there are multiple sheets in a predetermined section (notification section) upstream of the sheet separation unit in the sheet transport direction, where the separation position ends, and notifies information based on the determination result.

Description

Technical Field

[0001] The present invention relates to an image forming system and an information processing apparatus.

Background Art

[0002] The image forming apparatus described in Patent Document 1 detects a paperless jam in which a recording material does not reach a transport roller from a storage unit of the recording material.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide an image forming apparatus (image forming system) that detects a state in which a recording material is not normally conveyed.

Means for Solving the Problems

[0005] An image forming system according to one aspect of the present invention is an image forming system comprising an image forming apparatus, an information processing apparatus capable of communicating with the image forming apparatus, and a display device capable of displaying information, wherein the image forming apparatus comprises a storage section for storing recording material, a paper feeding section that contacts the recording material stored in the storage section, and a paper feeding section that feeds the recording material that has come into contact with the paper feeding section, and a separation section provided downstream of the paper feeding section in the transport direction in which the paper feeding section transports the recording material, and which contacts the recording material fed by the paper feeding section. The device comprises a separation unit that separates and transports the recording material into individual sheets, and a detection unit that detects the transported recording material, wherein when information based on the detection result of the detection unit indicates that multiple sheets of the recording material are simultaneously located in the notification section, the information processing device notifies the display device to display information that multiple sheets of the recording material are in the notification section, and the notification section is a section in the transport direction that is downstream of the midpoint of the line segment connecting the paper feed contact unit and the separation contact unit, and upstream of the separation contact unit.

[0006] An information processing apparatus according to another aspect of the present invention comprises: a storage section for storing recording material; a paper feeding section comprising a paper feeding contact section that contacts the recording material stored in the storage section, and for feeding the recording material that has come into contact with the paper feeding contact section; a separation section provided downstream of the paper feeding section in the transport direction in which the paper feeding section transports the recording material, and comprising a separation contact section that contacts the recording material fed by the paper feeding section, the separation section for separating and transporting the recording material into individual sheets; and a detection section for detecting the transported recording material. An information processing apparatus capable of communicating with an image forming apparatus, comprising a control unit that, when information received from the image forming apparatus based on the detection result of the detection unit indicates that multiple recording materials are simultaneously located in the notification section, notifies by displaying information on a display device that multiple recording materials are in the notification section, wherein the notification section is a section downstream of the midpoint of the line segment connecting the paper feed contact section and the separation contact section, and upstream of the separation contact section, in the transport direction. [Effects of the Invention]

[0007] According to the present invention, an image forming apparatus (image forming system) can be provided that can detect a state in which recording material is not being transported properly. [Brief explanation of the drawing]

[0008] [Figure 1] A cross-sectional view showing an example of the hardware configuration of an image forming apparatus. [Figure 2] A cross-sectional view showing an example of a configuration related to sheet feeding in an image forming apparatus. [Figure 3] A block diagram showing an example of the control configuration of an image forming apparatus. [Figure 4] This diagram shows an example of a paper cassette with sheets loaded. [Figure 5] This figure shows an example of feeding the top sheet S1 using a pick roller. [Figure 6] This diagram shows an example of a sheet bundle that has moved close to the separation point. [Figure 7] A diagram showing an example of the paper feed start position for the top sheet S1. [Figure 8] This diagram shows examples of sensor arrival times corresponding to each paper feed start position. [Figure 9] A diagram showing an example of the paper feed start position for the top sheet S1. [Figure 10] A scatter plot showing an example of the distribution of measurement results for sensor arrival time Ts. [Figure 11] A flowchart illustrating the procedure for determining whether multiple sheets are located near the separation point. [Figure 12] A diagram showing an example configuration of an image forming system including a server device. [Figure 13] A cross-sectional view (second embodiment) showing an example of a configuration related to sheet feeding in an image forming apparatus. [Figure 14] A diagram showing an example of the output signal state of the sheet sensor (second embodiment). [Figure 15] A cross-sectional view showing an example configuration related to sheet feeding in an image forming apparatus, and a schematic diagram showing an example configuration of the rotation detection unit (third embodiment). [Figure 16]Figure showing an example of the operation of the encoder when the sheet arrives (Example 4). [Figure 17] Figure showing an example of the state indicated by the output signal of the photo interrupter (Example 4). [Figure 18] Cross-sectional view showing a configuration example related to sheet feeding in an image forming apparatus (Example 5). [Figure 19] Figure showing an example of the operation of the rotation detection unit when the sheet arrives at the separation position (Example 5). [Figure 20] Cross-sectional view showing a configuration example related to sheet feeding in an image forming apparatus (Example 6). [Figure 21] Top view showing a configuration example related to sheet feeding in an image forming apparatus (Example 6). [Figure 22] Figure showing an example of the time change of the torque of the drive motor (Example 6). [Figure 23] Cross-sectional view showing a configuration example related to sheet feeding in an image forming apparatus (Modified example). [Figure 24] Figure showing an example of the screen displayed on the display unit 301 of the maintenance computer 300.

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, not all of these plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant descriptions are omitted.

[0010] [Example 1] FIG. 1 is a cross-sectional view showing a schematic configuration example of an image forming apparatus according to Example 1. Hereinafter, this example will be described by taking an image forming apparatus 100 configured as an electrophotographic color laser printer as an example.

[0011] The image forming apparatus 100 includes an image forming unit 100A that forms toner images of four colors: yellow (Y), magenta (M), cyan (C), and black (K). The image forming unit 100A includes four photosensitive drums (photoreceptors) 101Y, 101M, 101C, and 101K, and an intermediate transfer belt 102. The Y, M, C, and K at the end of the reference numerals indicate that the corresponding components are for yellow, magenta, cyan, and black developer (toner), respectively. The image forming unit 100A further includes primary transfer rollers 106Y, 106M, 106C, and 106K that transfer (primary transfer) the toner images formed on the photosensitive drums 101Y, 101M, 101C, and 101K onto the intermediate transfer belt 102. The primary transfer rollers 106Y, 106M, 106C, and 106K are subjected to a transfer voltage from a transfer power supply (not shown), which creates a potential difference between the photosensitive drums 101Y, 101M, 101C, and 101K and the intermediate transfer belt 102. This potential difference causes the toner image to be transferred from the photosensitive drums 101Y, 101M, 101C, and 101K to the intermediate transfer belt 102. The image forming unit 100A further includes a secondary transfer roller 50 that transfers the toner image transferred to the intermediate transfer belt 102 to the sheet S (secondary transfer).

[0012] When the image forming operation by the image forming unit 100A begins, the laser scanner 103 irradiates the uniformly charged photosensitive drums 101Y, 101M, 101C, and 101K with light corresponding to the image signal. This forms an electrostatic latent image on the photosensitive drums 101Y, 101M, 101C, and 101K. The image forming unit 100A develops the electrostatic latent image on the corresponding photosensitive drums 101Y, 101M, 101C, and 101K with toner stored in the developing cartridges 104Y, 104M, 104C, and 104K, thereby forming a toner image (visible image). The toner images of each color formed on the photosensitive drums 101Y, 101M, 101C, and 101K are transferred onto the intermediate transfer belt 102 as described above. This forms a multi-color toner image on the intermediate transfer belt 102. Subsequently, the toner image formed on the intermediate transfer belt 102 is transported to the secondary transfer section by the intermediate transfer belt 102. The secondary transfer section corresponds to the nip section formed between the intermediate transfer belt 102 and the secondary transfer roller 50.

[0013] In accordance with the timing of this image formation operation, the sheets S are fed from the paper feed cassette 10 to the transport path and transported through the transport path to the image formation unit 100A (secondary transfer unit). Specifically, the pick roller 20, feed roller 21, and separation roller 22 feed and transport the sheets S one by one from the paper feed cassette 10. They are then transported to the secondary transfer unit by the transport roller pair 23 and the registration roller pair 40. The registration roller pair 40 corrects the skew of the sheets S. The paper feed cassette 10 is an example of a storage unit that houses the recording material (sheets) used for image formation.

[0014] The sheet S is transported to the secondary transfer section at the same time that the toner image on the intermediate transfer belt 102 is transported to the secondary transfer section. A secondary transfer voltage is applied to the secondary transfer roller 50, transferring the toner image from the intermediate transfer belt 102 to the sheet S. The sheet S, on which the toner image has been transferred, is then transported to the fixing section 60, where it is heated and pressurized to fix the toner image to the sheet S. After this fixing process is completed, the sheet S is discharged to the discharge section 111 at the top of the device by the discharge roller 110.

[0015] <Sheet paper feeding configuration> Figure 2 is a cross-sectional view showing an example of the configuration related to sheet feeding in the image forming apparatus 100. The paper feed cassette 10 houses the sheets S (sheet bundle S0). The paper feed cassette 10 includes an intermediate plate (lift-up plate) 11 that is pivotally supported within the paper feed cassette 10 and configured to rotate. Sheet S1 is the uppermost sheet from the sheet bundle S0 that is next fed from the paper feed cassette 10 to the transport path.

[0016] The pick roller 20 is positioned to press the sheet bundle S0, which has been lifted up by the middle plate 11 as described later, downward in the figure by means of a spring (not shown). The feed roller 21 and the separation roller 22 constitute a separation section (sheet separation section) that separates sheets one by one from the sheet bundle S0 (separating the top sheet S1) and sends them to the transport path. The feed roller 21 and the separation roller 22 are pressed together by a spring (not shown) from the separation roller 22 side toward the feed roller 21 side. The contact section between the feed roller 21 and the separation roller 22 corresponds to the separation position 22A (separation contact section) where sheet separation (separation of the top sheet S1 from the other sheets) takes place. The pick roller 20, feed roller 21 and separation roller 22 are each made of rubber rollers. The transport roller pair 23 is made of a rubber roller and a roller, and is pressed together by a spring (not shown) from the roller side toward the rubber roller side.

[0017] The transport path for the sheet S1 is provided with a pre-separation guide 24, a post-separation guide 25, and a transport guide 26, which guide the sheet S1 being transported by the pick roller 20, the feed roller 21, and the transport roller pair 23. The pick roller 20, the feed roller 21, and the transport roller pair 23 are driven by a motor (not shown) used as the same drive source. The transmission of driving force from the motor to the pick roller 20 and the feed roller 21 is controlled by turning the paper feed clutch 29 (Figure 3), which will be described later, ON / OFF.

[0018] In this embodiment, a transport sensor 27 is further positioned downstream of the transport roller pair 23 in the transport path of the sheet S1. The transport sensor 27 consists of a photointerrupter and a flag (not shown) and is used to detect the leading edge of the sheet S1. When it is detected that the leading edge of the sheet S1 has come into contact with the flag and the optical axis of the photointerrupter has been blocked, it is determined that the leading edge of the sheet S1 has reached the transport sensor 27.

[0019] Next, the feeding and transporting of sheets from the paper feed cassette 10 will be described. When the sheet bundle S0 is placed in the paper feed cassette 10, the bottom surface of the sheet bundle S0 is placed on the middle plate 11 of the paper feed cassette 10. When the paper feed cassette 10 is mounted on the image forming apparatus 100, the middle plate 11 is driven by a drive motor (not shown) and rotates around a pivot point, thereby lifting up the sheet bundle S0. As a result, the pick roller 20 comes into contact with the sheet bundle S0. When the pick roller 20 presses the uppermost sheet S1 with a predetermined pressure, the lifting by the middle plate 11 stops, and the position of the sheet S1 is maintained.

[0020] Subsequently, the paper feed clutch 29 (Figure 3) is turned ON by instruction from the control unit 70 (Figure 3), causing the pick roller 20 to start rotating. This initiates the feeding of the top sheet S1 of the sheet bundle S0 in the paper feed cassette 10, which is then transported to the contact area (separation position 22A) formed between the feed roller 21 and the separation roller 22, guided by the pre-separation guide 24.

[0021] The separation roller 22 has a built-in torque limiter (not shown). The rotational torque of the torque limiter is preset so that the separation roller 22 rotates when sheets are conveyed one by one, but does not rotate when multiple sheets are conveyed. In this way, the sheets S1 that are separated and conveyed one by one by the separation roller 22 are conveyed to the conveying roller pair 23 while being guided by the post-separation guide 25. The sheets S1 that are conveyed by the conveying roller pair 23 are conveyed to the register roller pair 40 while being guided by the conveying guide 26.

[0022] In this embodiment, the pick roller 20 is an example of a paper feeding unit that has a paper feeding contact portion that contacts the recording material (sheet) stored in the storage unit (paper feed cassette 10) and feeds the recording material that has come into contact with the paper feeding contact portion to the transport path. The feed roller 21 and the separation roller 22 are separation units provided downstream of the paper feeding unit (pick roller 20) in the transport direction in which the paper feeding unit (pick roller 20) transports the recording material, and have a separation contact portion that contacts the recording material (sheet) fed by the paper feeding unit, and are an example of a separation unit (sheet separation unit) that separates the recording material into individual sheets for transport. The transport sensor 27 is an example of a detection unit that detects the transported recording material (sheet). In this embodiment, the detection unit (transport sensor 27) is located downstream of the sheet separation unit (feed roller 21 and separation roller 22) in the sheet transport direction. In this specification, the detection of a recording material by the detection unit includes not only the direct detection of the recording material by the detection unit, but also indirect detection, such as detecting the movement of a specific component in conjunction with the movement of the recording material.

[0023] <Control configuration of image forming apparatus> Figure 3 is a block diagram showing an example of the control configuration of the image forming apparatus 100. As shown in the figure, the image forming apparatus 100 can communicate with external devices such as a host computer 90 via a network. The host computer 90 comprises a main unit 91 and an operation unit 92. The main unit 91 is configured to instruct the image forming apparatus 100 to perform printing (image forming operation) via the network. The operation unit 92 has a display device (e.g., liquid crystal display) that outputs information to the user and an input device (e.g., touch panel sensor, keyboard, pointing device) that receives instructions from the user.

[0024] The image forming apparatus 100 comprises a printer engine 80, a video controller 81, and an operation unit 82. The operation unit 82 has a display device (e.g., a liquid crystal display) that outputs information to the user and an input device (e.g., a touch panel sensor, operation keys) that receives instructions from the user. The video controller 81 transmits print data and print instructions received from the host computer 90 to the printer engine 80.

[0025] The printer engine 80 comprises a control unit (engine control unit) 70, a system bus 74, and input / output (IO) ports 75. The control unit 70 includes a CPU 71, ROM 72, and RAM 73, and controls the operation of the entire image forming apparatus 100. The CPU 71 loads the program and various data stored in the ROM 72 into the RAM 73 and executes the program using the RAM 73 as a workspace. The control unit 70 (CPU 71) can access the IO ports 75 via the bidirectional system bus 74. A paper feed clutch 29 and a transport sensor 27 are connected to the IO ports 75. The CPU 71 controls these devices via the IO ports 75. Other devices besides the paper feed clutch 29 and the transport sensor 27 may also be connected to the IO ports 75. The control unit 70 (CPU 71) starts the rotation of the pick roller 20 and starts the paper feeding operation of the uppermost sheet S1 by switching the paper feed clutch 29 from the OFF state to the ON state.

[0026] <Measurement of paper feeding operation and sensor arrival time> Using Figures 4 and 5, we will explain the sheet feeding operation and the measurement of the sensor arrival time Ts, which is the time from the start of sheet feeding to the timing of sheet detection by the transport sensor 27.

[0027] Figure 4 shows an example of the state in which the sheet bundle S0 is set in the paper feed cassette 10, and shows the state just before the lift-up of the sheet bundle S0 by the intermediate plate 11 begins. Figure 5 shows an example of feeding the top sheet S1 by the pick roller 20. Figure 5(A) shows the state after the lift-up of the sheet bundle S0 is complete and before the feeding of the top sheet S1 begins. In the following description, the position of the leading edge of the top sheet S1 when the lift-up of the sheet bundle S0 in the paper feed cassette 10 is complete, as shown in Figure 5(A), will be referred to as the "cassette position" (cassette position 10B in Figure 7). Figure 5(B) shows the state in which the top sheet S1 has been fed from the paper feed cassette 10 and the leading edge of the top sheet S1 has reached the separation position 22A.

[0028] In the image forming apparatus 100 of this embodiment, it is recommended to set the sheet bundle S0 so that it abuts against the leading edge 10A of the paper feed cassette 10, as shown in Figure 4. When the paper feed cassette 10 is mounted in the image forming apparatus 100 with the sheet bundle S0 set in this manner, the control unit 70 instructs the intermediate plate 11 to start lifting up the sheet bundle S0. The lifting up of the sheet bundle S0 is completed in the state shown in Figure 5(A).

[0029] The operation of the image forming apparatus 100 from the state shown in Figure 5(A), when the feeding (transportation) of the top sheet S1 is started until the leading edge of the sheet reaches the position of the transport sensor 27, will be further explained. In this embodiment, from the start of the paper feeding operation by the pick roller 20 until the leading edge of the sheet S1 reaches the position of the transport sensor 27, the rotational speeds of the pick roller 20, the feed roller 21, and the transport roller pair 23 are all controlled to be constant.

[0030] First, the CPU 71 switches the paper feed clutch 29 from the OFF state to the ON state by sending a control signal to start the paper feeding operation to the paper feed clutch 29 via the system bus 74 and IO port 75. This starts the rotation of the pick roller 20 and starts the feeding (transportation) of the top sheet S1. The CPU 71 also stores the timing of sending the control signal to start the paper feeding as the paper feeding start timing T1 in the RAM 73.

[0031] Subsequently, the top sheet S1, transported by the paper feed roller 20, is transported to the transport sensor 27 by the feed roller 21 and the transport roller pair 23. When the leading edge of the top sheet S1 is detected by the transport sensor 27, the output signal of the transport sensor 27 switches from the OFF state to the ON state. The CPU 71 monitors the output signal of the transport sensor 27 via the IO port 75 and the system bus 74. Based on the output signal of the transport sensor 27, the CPU 71 stores the timing at which the leading edge of the top sheet S1 is detected by the transport sensor 27 as the sheet detection timing T2 in the RAM 73. The CPU 71 measures the time from the paper feed start timing T1 to the sheet detection timing T2 as the sensor arrival time Ts and stores it in the RAM 73. Thus, in this embodiment, the CPU 71 functions as an example of a measuring unit that measures the time from the paper feed start timing of the recording material to the timing at which the detection unit detects the recording material (sensor arrival time Ts).

[0032] In the image forming apparatus 100, after several sheets have been fed from the paper feed cassette 10, the leading edge of the top sheet S1 may move from the cassette position shown in Figure 5(A) to the separation position 22A shown in Figure 5(B). In this case, the feeding (transportation) of the top sheet S1 begins from the separation position 22A. In this embodiment, the pick roller 20 and the feed roller 21 are driven by the same drive system. Therefore, when the paper feed clutch 29 is turned ON and the pick roller 20 starts rotating, the feed roller 21 also starts rotating. That is, at the paper feeding start timing T1, the feed roller 21 also starts rotating, and the top sheet S1 is transported to the transport sensor 27 by the feed roller 21 and the transport roller pair 23. The CPU 71 measures the sensor arrival time Ts for the top sheet S1 that has been fed from the separation position 22A and transported to the position of the transport sensor 27, similar to the case when the feeding of the top sheet S1 begins from the cassette position shown in Figure 5(A).

[0033] Here, let Ta be the measured value of the sensor arrival time Ts when feeding of the top sheet S1 starts from the cassette position shown in Figure 5(A). Also, let Tb be the measured value of the sensor arrival time Ts when feeding of the top sheet S1 starts from the separation position 22A shown in Figure 5(B). In this case, the sensor arrival times Ta and Tb have the relationship Ta > Tb. This is because the separation position 22A shown in Figure 5(B) is downstream in the sheet transport direction from the cassette position shown in Figure 5(A). In other words, the sheet transport distance from the separation position 22A shown in Figure 5(B) to the position of the transport sensor 27 is shorter than the sheet transport distance from the cassette position shown in Figure 5(A) to the position of the transport sensor 27.

[0034] <Causes of transport delay or paper jam in the sheet separation section> If multiple sheets are placed together in the area near the separation position 22A, a delay may occur in the transport of the top sheet S1, or a paper jam may eventually occur. This phenomenon can occur, for example, when a user pulls out the paper feed cassette 10 and adds multiple sheets to it while a sheet bundle S0 remains in the paper feed cassette 10.

[0035] Here, Figure 6 shows an example where the leading edge of a sheet bundle S2, consisting of multiple sheets, has entered the vicinity of the separation position 22A. In this example, sheet bundle S2 is a sheet bundle that the user added to the paper feed cassette 10 by pulling it out while sheet bundle S0 remained in the paper feed cassette 10.

[0036] As shown in Figure 6, when a sheet bundle S2 is added on top of a sheet bundle S0 that remains in the paper feed cassette 10, the coefficient of friction between the top sheet of sheet bundle S0 and the bottom sheet of sheet bundle S2 may decrease. In this case, when the paper feeding operation is started by instruction from the control unit 70 and the pick roller 20 starts to rotate, not only the top sheet S1 (of the sheet bundles consisting of sheet bundles S0 and S2) but also the added sheet bundle S2 may all enter the vicinity of the separation position 22A. For example, if 10 or more sheets are added to the sheet bundle S2, and these sheets enter the vicinity of the separation position 22A, the sheets will be caught between the feed roller 21 and the pre-separation guide 24, increasing the transport resistance. As a result, although the pick roller 20 and feed roller 21 rotate to transport the sheets, the transport of the top sheet S1 becomes difficult due to this increase in transport resistance. This may lead to a delay in the transport of sheet S1 or the occurrence of a paper jam.

[0037] <Processing for determining multiple sheets> In the image forming apparatus 100 of this embodiment, the control unit 70 (CPU 71) performs a process to determine (detect) if multiple sheets are in the vicinity (area) of the separation position 22A at the start of the sheet feeding operation. This makes it possible to determine sheet transport delay or paper jam caused by multiple sheets being in the vicinity of the separation position 22A.

[0038] Figure 7 shows an example of the paper feeding start position for the top sheet S1, including the pick roller position 20A, cassette position 10B, separation position 22A, and midpoint position 28. The paper feeding start position corresponds to the leading edge position of the sheet (top sheet S1) at the timing when the paper feeding operation of the sheet (top sheet S1) is started by instruction from the control unit 70 (paper feeding start timing). In Figure 7, the pick roller position 20A is the position where the pick roller 20 contacts the top sheet S1, and corresponds to the paper feeding contact point. The cassette position 10B is the leading edge position of the top sheet S1 when the sheet bundle S0 in the paper feeding cassette 10 has finished being lifted up. The separation position 22A corresponds to the separation contact point where the feed roller 21 and the separation roller 22 contact, and is the position where the top sheet S1 is separated from the other sheets. The midpoint position 28 is the midpoint of the line segment connecting the pick roller position 20A (paper feed contact point) and the separation position 22A (separation contact point).

[0039] Figure 8 shows an example of the sensor arrival time Ts when the top sheet S1 is fed with its leading edge positioned at each paper starting position shown in Figure 7. The sensor arrival time Ts is the time from the timing when the paper feeding operation of the sheet (top sheet S1) is started by instruction from the control unit 70 (paper feeding start timing T1) to the timing when the sheet is detected by the transport sensor 27 (sheet detection timing T2).

[0040] Figure 8 shows the sensor arrival times T0, Ta, Tc, and Tb corresponding to the pick roller position 20A, cassette position 10B, midpoint position 28, and separation position 22A, respectively, as measurement results of the sensor arrival time Ts. Sensor arrival time T0 is the sensor arrival time measured when the feeding of the top sheet S1 starts with the leading edge of the top sheet S1 positioned at the pick roller position 20A. Sensor arrival time Ta is the sensor arrival time measured when the feeding of the top sheet S1 starts with the leading edge of the top sheet S1 positioned at the cassette position 10B. Sensor arrival time Tc is the sensor arrival time measured when the feeding of the top sheet S1 starts with the leading edge of the top sheet S1 positioned at the midpoint position 28. Sensor arrival time Tb is the sensor arrival time measured when the feeding of the top sheet S1 starts with the leading edge of the top sheet S1 positioned at the separation position 22A.

[0041] Along the sheet transport direction, the position of the transport sensor 27 is approached in the order of pick roller position 20A, cassette position 10B, midpoint position 28, and separation position 22A. That is, the transport distance from each paper feed start position to the position of the transport sensor 27 becomes shorter. Therefore, as shown in Figure 8, the sensor arrival times T0, Ta, Tc, and Tb corresponding to the pick roller position 20A, cassette position 10B, midpoint position 28, and separation position 22A become shorter in the order of T0, Ta, Tc, and Tb (i.e., T0 > Ta > Tc > Tb).

[0042] In this embodiment, a predetermined section that is upstream of the sheet separation section (separation position 22A) in the sheet conveyance direction and has the separation position 22A as its end point in the sheet conveyance direction is preset as a detection section TD (notification section) for detecting that there are (sheets entering) a plurality of sheets in the vicinity (area) of the separation position 22A at the start timing of the sheet feeding operation. The control unit 70 measures the time (sensor arrival time Ts) from the start timing T1 of the sheet feeding operation of the uppermost sheet S1 to the timing T2 when the sheet S1 is detected by the conveyance sensor 27. Each time the uppermost sheet S1 is fed by the sheet feeding operation, the control unit 70 measures the sensor arrival time Ts, and based on the measurement result, determines whether or not a plurality of sheets are in the detection section TD (area near the separation position 22A).

[0043] In this embodiment, as an example, a section from the midpoint position 28 to the separation position 22A in the sheet conveyance direction is set as the detection section TD. The detection section TD is defined, for example, as a time section based on the sensor arrival time. Specifically, a time section shorter than the sensor arrival time Tc corresponding to the midpoint position 28 is defined as the time section corresponding to the detection section TD. Thereby, when the sensor arrival time Ts measured for the uppermost sheet S1 fed by the sheet feeding operation is shorter than Tc (Ts < Tc), it can be detected that the sheet feeding start position of the sheet was within the detection section TD. In this embodiment, when the measured sensor arrival time Ts is shorter than Tc (Ts < Tc) for a plurality of sheets, the control unit 70 determines that a plurality of sheets are in (entering) the detection section TD.

[0044] In this embodiment, the detection interval TD is determined based on the sensor arrival time Ts (i.e., time information), but the detection interval TD may also be determined based on distance information. For example, if the drive systems of the pick roller 20 and the feed roller 21 are equipped with encoders that detect rotational speed, and distance information (sheet transport distance) can be obtained using these encoders, the detection interval TD may be determined using distance information. Also, in this embodiment, the section from the midpoint position 28 to the separation position 22A is defined as the detection interval TD, but a different section (for example, the section from the midpoint position 28 to the position of the transport sensor 27) may also be defined as the detection interval TD.

[0045] <Decision processing based on sensor arrival time> The determination process based on the sensor arrival time Ts measured as described above will be explained in more detail using Figures 9 and 10.

[0046] Figure 9 shows an example of the starting position for feeding the top sheet S1 in a sheet stack set in the paper cassette 10. Figure 9(A) shows the state where the leading edge of the extended sheet stack S2 is at cassette position 10B (Figure 7). Figure 9(B) shows the state where the leading edge of the extended sheet stack S2 is at separation position 22A. Figure 9(C) shows the state where the leading edge of the sheet stack S3 that remained in the paper cassette 10 after the feeding of sheet stack S2 is at cassette position 10B (Figure 7). Sheet stack S3 is the remaining sheet stack that remained in the paper cassette 10 before sheet stack S2 was replenished (extended) in the paper cassette 10. Figure 10 is a scatter plot showing an example of the distribution of measurement results of the sensor arrival time Ts in each state of Figure 9, with the horizontal axis showing the page count and the vertical axis showing the sensor arrival time Ts.

[0047] In the example shown in Figure 9(A), multiple sheets (for example, 30 sheets) are added on top of the remaining sheet bundle S3 as a sheet bundle S2. When the paper feeding operation is performed with the leading edge of the sheet bundle S2 at the cassette position 10B, the measured values ​​of the sensor arrival time Ts are distributed around the sensor arrival time Ta corresponding to the cassette position 10B, as shown in Figure 10.

[0048] Subsequently, once a certain number of sheets (for example, 15 sheets) of the added sheet bundle S2 have been transported, the remaining sheets of the added sheet bundle S2 are transported together to the vicinity of the separation position 22A, as shown in Figure 9(B), due to the aforementioned decrease in the coefficient of friction between the added sheets and the original remaining sheets. As a result, the feeding of the top sheet S1 begins from a position downstream in the transport direction from the midpoint position 28 (Figure 7). Consequently, as shown in Figure 10, the measured sensor arrival time Ts becomes shorter than the sensor arrival time Tc corresponding to the midpoint position 28 and is distributed around the sensor arrival time Tb corresponding to the separation position 22A.

[0049] After the feeding of the added sheet bundle S2 is complete, the remaining sheet bundle S3 is fed. Since the leading edge of the remaining sheet bundle S3 is at cassette position 10B (Figure 7), the starting position for feeding the top sheet S1 returns from (near) separation position 22A back to cassette position 10B. As a result, as shown in Figure 10, the measured sensor arrival time Ts of the top sheet S1 is once again distributed around the sensor arrival time Ta corresponding to cassette position 10B.

[0050] The control unit 70 (CPU 71) performs a process to determine, as shown in Figure 9(B), that multiple sheets are near (entered) the separation position 22A, based on the measurement result of the sensor arrival time Ts of the top sheet S1. For this determination process, the control unit 70 has a sheet counter for counting sheets that are within the detection section TD (sheets whose paper feed start position is within the detection section TD). Each time the top sheet S1 is fed, the control unit 70 measures the sensor arrival time Ts, and if it determines that the measured sensor arrival time Ts is within the detection section TD, it increments the count value of the sheet counter by 1. On the other hand, if the control unit 70 determines that the measured sensor arrival time Ts is outside the detection section TD, it decrements the count value of the sheet counter by 1 (if the count value is 0, it remains 0). This count value is stored in the RAM 73.

[0051] The control unit 70 determines, for example, that multiple sheets are near (entered into) the separation position 22A when the count value held in the RAM 73 exceeds a predetermined threshold. The control unit 70 notifies the user of the determination result as necessary (for example, by displaying it on the operation unit 82).

[0052] <Processing Procedure> Figure 11 is a flowchart showing an example of a processing procedure executed by the control unit 70 (CPU 71) in the image forming apparatus 100. This procedure is for determining whether multiple sheets are near (entangled in) the separation position 22A. The control unit 70 (CPU 71) executes this procedure each time it feeds one sheet at a time from the paper feed cassette 10.

[0053] In S101, the CPU 71 (control unit 70) sends a control signal to the paper feed clutch 29 to start paper feeding, and acquires the timing of the transmission of the control signal as the start timing of the paper feeding operation (paper feeding start timing) T1. Then, in S102, the CPU 71 acquires the timing (sheet detection timing) T2 when the fed sheet (top sheet S1) is detected by the transport sensor 27, based on the output signal of the transport sensor 27. In S103, the CPU 71 acquires the sensor arrival time Ts by calculating the sensor arrival time Ts based on the paper feeding start timing T1 and the sheet detection timing T2.

[0054] In S104, the CPU 71 determines whether the measured sensor arrival time Ts is within the detection interval TD. This determination is equivalent to determining whether the paper feed start position of the fed sheet is within the detection interval TD. If the sensor arrival time Ts is within the detection interval TD (Ts ≤ Tc in this example) (i.e., the paper feed start position of the fed sheet is within the detection interval TD), the CPU 71 increments the count value of the sheet counter held in RAM 73 by 1 in S105 and proceeds to S107. On the other hand, if the sensor arrival time Ts is not within the detection interval TD (Ts > Tc in this example) (i.e., the paper feed start position of the fed sheet is outside the detection interval TD), the CPU 71 decrements the count value of the sheet counter held in RAM 73 by 1 in S106 and proceeds to S107.

[0055] In S107, the CPU 71 determines whether the count value of the sheet counter is equal to or greater than a predetermined threshold (threshold number of sheets). This threshold is set to, for example, 10. If the count value is equal to or greater than the threshold, in S108 the CPU 71 generates a determination result indicating that multiple sheets are located near the separation position 22A (multiple sheets are in the detection section TD), and proceeds to S109. In S109, the CPU 71 performs a notification process to notify the determination result from S108 (for example, displaying the determination result on the operation unit 82), and terminates the process.

[0056] Furthermore, if the count value is less than a predetermined threshold, the CPU 71 proceeds from S107 to S110, generates a determination result indicating that there are no multiple sheets in the vicinity of separation position 22A (i.e., there are no multiple sheets in detection section TD), and terminates processing.

[0057] As shown in Figure 9(B), if multiple sheets added to the paper feed cassette 10 are near (entered) the separation position 22A, the count value of the sheet counter in S105 increases each time a sheet is fed. When the number of sheets (count value) determined to be within the detection section TD finally exceeds the threshold number (10 sheets in this example), the CPU 71 performs a process to determine that multiple sheets are near the separation position 22A.

[0058] The sheet counter's count value may be reset at predetermined intervals of sheets. For example, a predetermined interval of 15 sheets may be set, and the count value may be reset when the number of fed sheets exceeds 15. Furthermore, for each predetermined interval, the number of times it has been determined that multiple sheets are near the separation position 22A may be maintained, for example, for each user. This makes it possible to determine, for example, that a user with a high number of such occurrences tends to have multiple sheets enter the separation position 22A at the start of feeding when a sheet (sheet bundle) is set in the paper cassette 10. The control unit 70 (CPU 71) may also perform a process to notify the result of this determination. Alternatively, without setting the above-mentioned intervals of sheets, the sheet counter's count value may be reset each time the paper cassette 10 is opened or closed.

[0059] <Example of notification processing> The control unit 70 may be configured to notify the user of the determination result using the operation unit 82 when it determines that multiple sheets have entered the sheet separation section (near the separation position 22A). For example, the control unit 70 may display a message on the operation unit 82 indicating that multiple sheets have entered the vicinity of the sheet separation section.

[0060] The control unit 70 may issue the above-mentioned notification in response to its determination that multiple sheets have entered the sheet separation section. Alternatively, the control unit 70 may issue such notification after it has determined multiple times that multiple sheets have entered the sheet separation section (i.e., it may issue a notification that there is a tendency for multiple sheets to enter the sheet separation section).

[0061] Normally, when the image forming apparatus 100 starts the paper feeding operation to feed sheets from the paper cassette 10, if the transport sensor 27 does not detect a sheet even after a predetermined time has elapsed, it determines that a jam has occurred in the sheet (topmost sheet S1) and stops the printing operation. In addition, in the image forming apparatus 100, if multiple sheets get stuck in the sheet separation section (near the separation position 22A) (Figure 6), the transport of the sheets may be hindered by the increase in transport resistance mentioned above (the transport sensor 27 does not detect a sheet even after a predetermined time has elapsed since the start of the paper feeding operation), and a jam may occur.

[0062] As described above, in the case of a jam caused by multiple sheets getting stuck in the sheet separation section (near the separation position 22A), the CPU 71 (control unit 70) may perform a process to notify (display) candidate causes of the jam based on the above determination result. If the control unit 70 has determined multiple times that multiple sheets are stuck in the sheet separation section before the jam occurs, it may notify that multiple sheets have gotten stuck in the sheet separation section (near the separation position 22A) as a candidate cause of the jam. For example, the CPU 71 may display a message on the operation unit 82 such as, "There is a possibility that a paper jam has occurred because multiple sheets are stuck in the sheet separation section."

[0063] Furthermore, the CPU 71 may notify users who are identified as having a tendency to insert multiple sheets into the separation position 22A of a message to guide them on how to handle the sheets to be set in the image forming apparatus 100, in order to prevent jams from occurring. For example, the CPU 71 may display a message on the operation unit 82 regarding the recommended method for setting the sheets, such as the following: - "Please separate the sheets and set them up." - "Please rotate the sheet 180 degrees, or flip the sheet over and set it in place." - "Rotate the sheet 90 degrees before setting it, and feed the paper using either the horizontal or vertical feed setting." - "When loading new sheets into the paper cassette, please do not separate the sheets into small bundles before loading." - "Please use up all the sheets in the cassette before inserting a new one."

[0064] Furthermore, the CPU 71 may display the following message on the operation unit 82 in order to prevent jams (paper jams) related to the characteristics of the sheet. - "Check the sheets for any damage or burrs / folds at the edges, and remove any affected sheets." - "Please avoid using paper that has come into contact with the wrapping paper." - "If you are using recycled paper, please refrain from using this." - "Please change the type of seat."

[0065] Furthermore, if the image forming apparatus 100 has multiple paper feeding units (paper cassettes or trays), the CPU 71 may display a message on the operation unit 82 guiding the user to set sheets into a manual feed tray that can hold sheets one at a time (for example, a message such as "Please change the tray that stores the sheets to the manual feed tray.").

[0066] The notification process described above is just one example, and the CPU 71 operates to notify the user of a message regarding sheet handling to prevent multiple sheets from getting stuck near the separation position 22A as much as possible. Furthermore, if multiple sheets get stuck near the separation position 22A at the start of paper feeding, it can lead not only to jamming (paper jamming) but also to paper dust adhering to the feed roller 21 or separation roller 22, and accelerated wear of the separation roller 22 due to the adhesion of paper dust. For this reason, the notification process described above is also effective in preventing such phenomena from occurring.

[0067] Furthermore, in addition to notification processing using the operation unit 82 of the image forming apparatus 100, the CPU 71 may also perform notification processing using the operation unit 92 of the host computer 90. For example, in S109, the CPU 71 may notify the host computer 90 via the network of a message indicating the notification content from the operation unit 92.

[0068] <Other examples of announcements> In this embodiment, we have described an example in which, when a sheet bundle S2 is added on top of the sheet bundle S3 remaining in the paper feed cassette 10, multiple sheets may end up near the separation position 22A. However, when the number of sheets in the paper feed cassette 10 decreases and the last multiple sheets remain in the paper feed cassette 10, these multiple sheets may end up near the separation position 22A.

[0069] To prevent this, the paper feed cassette 10 may be equipped with a final paper separation sheet (not shown) made of rubber or nonwoven fabric as a double-feed prevention member. However, the friction coefficient of the separation sheet may decrease due to the adhesion or wear of paper dust. As a result, when the number of sheets in the paper feed cassette 10 decreases and the time for feeding the final sheet approaches, multiple sheets may enter the vicinity of the separation position 22A, which may lead to jams (paper jams). For this reason, when the CPU 71 (control unit 70) detects that the number of sheets in the paper feed cassette 10 has decreased using a sensor or the like provided in the paper feed cassette 10, and determines that there is a tendency for multiple sheets to enter the separation position 22A, it may notify a message prompting the replacement or cleaning of the final paper separation sheet (double-feed prevention member) in the paper feed cassette 10.

[0070] <Summary> As described above, the image forming apparatus 100 of this embodiment is equipped with a transport sensor 27 that is positioned downstream of the sheet separation section (feed roller 21 and separation roller 22) in the sheet transport direction and is capable of detecting sheets. The control unit 70 (CPU 71) acquires the detection result from the transport sensor 27 each time the pick roller 20 performs a paper feeding operation, and based on the acquired detection result, determines whether or not there are multiple sheets in the detection section TD, and notifies information based on the determination result. In this way, if the information based on the detection result from the detection section indicates that multiple recording materials (sheets) are simultaneously located in the notification section (detection section TD), the control unit 70 (CPU 71) notifies information that multiple recording materials are in the notification section.

[0071] According to this embodiment, the image forming apparatus 100 can determine if a paper feeding operation is being performed with multiple sheets near the sheet separation section and can notify information based on the determination result. This makes it possible to appropriately identify the cause of a malfunction in the image forming apparatus when a malfunction occurs due to multiple sheets entering the vicinity of the sheet separation section. For example, it becomes possible to determine whether the malfunction is due to the user's usage (such as how the sheets are set) or the characteristics of the sheets (and thus determine that it is a malfunction caused by a device failure). Thus, according to this embodiment, an image forming apparatus can be provided that can detect when recording material is not being transported properly.

[0072] Through such judgment and notification processes, for example, IT administrators can appropriately address malfunctions occurring in the image forming apparatus 100. Furthermore, for example, a company responsible for the maintenance of the image forming apparatus can appropriately determine whether or not service dispatch is necessary, thereby reducing unnecessary dispatches and improving the efficiency of resolving malfunctions.

[0073] Furthermore, according to this embodiment, it becomes possible to recognize that multiple sheets tend to get stuck in the sheet separation area (or nearby) when image formation is performed. This makes it possible to appropriately inform the user of information to prevent defects such as jams before they occur.

[0074] <Variations using server equipment> In this embodiment, an example has been described in which the above-described determination process and notification process are performed in the image forming apparatus 100, but these processes may also be performed by an external device. Figure 12 shows an example of the configuration of an image forming system in which a server device 200 capable of communicating with the image forming apparatus 100 via a network and a maintenance computer 300 connected to the server device 200 are further provided. In this example, the server device 200 is an example of an information processing device capable of communicating with the image forming apparatus, and the maintenance computer 300 is an example of a display device capable of displaying information.

[0075] In the image forming system shown in Figure 12, the server device 200 includes a control unit 201, which includes a CPU 202 and a storage device 203. The maintenance computer 300 includes a display unit 301. The maintenance computer 300 may be, for example, a terminal device of an IT administrator in an office, or a terminal device of a maintenance contractor (such as a PC capable of running monitoring tools). The maintenance computer 300 is configured to receive information based on the judgment results stored in the server device 200 as needed and display it on the display unit 301.

[0076] In the image forming apparatus 100, the control unit 70 (CPU 71) acquires the measurement result of the sensor arrival time Ts each time a sheet is fed, following the procedure shown in Figure 11 above (S103). The CPU 71 stores the measured value of the sensor arrival time Ts for each fed sheet in the RAM 73. Subsequently, the CPU 71 transmits the information stored in the RAM 73 to the server device 200 when the number of fed sheets (the number of sheets for which the measurement results of the sensor arrival time Ts are stored) reaches a predetermined number, or when a predetermined time has elapsed.

[0077] The server device 200 stores the information received from the image forming apparatus 100 in the storage device 203. The CPU 202 analyzes the information stored in the storage device 203. The CPU 202 uses the information stored in the storage device 203 to execute the processing from S104 onwards, for example, in the processing procedure shown in Figure 11. As a result, the server device 200 performs the judgment processing described above to generate a judgment result and performs a judgment result notification process (S107-S109). The judgment result notification process may be performed, for example, by transmitting the judgment result or information based on the judgment result to the maintenance computer 300, using the display unit 301 of the maintenance computer 300. As shown in Figure 24, the maintenance computer 300 notifies the information by displaying a screen on the display unit 301 that contains information that multiple recording materials are in the notification section (detection section TD).

[0078] The notification content on the maintenance computer 300 may be as described above, or it may be directed at the IT administrator or the maintenance company, for example, as shown in the following message. - "Multiple sheets tend to get stuck in the sheet separator. This increases the likelihood of jams, so please instruct users on the correct paper loading method." - "A jam has occurred due to multiple sheets becoming lodged in the sheet separator. Please instruct the user on the correct paper loading method."

[0079] The notification process described above is just one example. Based on the identified user tendencies, the notification may also communicate actions to prevent jams, or it may prompt appropriate action based on the cause of the jam. Alternatively, the server device 200 may perform the above-described assessment process once a day, combining the data from the current day with previous data, and the notification content may be determined based on the identified user tendencies.

[0080] Thus, the image processing system comprises an image forming apparatus 100, an information processing device (server device 200) capable of communicating with the image forming apparatus 100, and a display device (maintenance computer 300) capable of displaying information. The image forming apparatus 100 comprises a storage section (paper feed cassette 10) for storing recording material, a paper feeding section (pick roller 20), a separation section (feed roller 21 and separation roller 22), and a detection section (transport sensor 27) for detecting the transported recording material. The paper feeding section includes a paper feeding contact section that contacts the recording material stored in the storage section, and feeds the recording material that comes into contact with the paper feeding contact section. The separation section is provided downstream of the paper feeding section in the transport direction in which the paper feeding section transports the recording material, and includes a separation contact section that contacts the recording material fed to the paper feeding section, separating the recording material into individual sheets for transport. The information processing device (server device 200) notifies the system (server device 200) by displaying information on the display device (maintenance computer 300) that multiple recording materials are in the notification section (detection section TD) at the same time, based on the detection results from the detection unit. The notification section is defined as the section downstream from the midpoint of the line segment connecting the paper feed contact section and the separation contact section, and upstream from the separation contact section, in the direction of transport of the recording materials.

[0081] Thus, according to this embodiment, an image forming system can be provided that detects a state in which the recording material is not being transported normally and appropriately notifies information regarding the detection result. Although an example of applying the configuration of the first embodiment to an image forming system has been described here, it is also possible to apply the configurations of the second to sixth embodiments described below to the above-mentioned image forming system in a similar manner.

[0082] [Second Example] In the second embodiment, we will describe an example in which a sheet sensor located upstream of the sheet separation section (separation position 22A) in the sheet transport direction is used to determine that a paper feeding operation is being performed while multiple sheets are near the sheet separation section. In the following, we will omit explanations of parts that are common to the first embodiment.

[0083] Figure 13 is a cross-sectional view showing an example of the configuration related to sheet feeding in the image forming apparatus 100 of this embodiment. The image forming apparatus 100 of this embodiment includes a sheet sensor 150 located upstream of the sheet separation section (feed roller 21 and separation roller 22) instead of a transport sensor 27 (Figure 2) located downstream of the sheet separation section (feed roller 21 and separation roller 22) in the sheet transport direction. Figure 14 shows an example of the output signal state of the sheet sensor 150, with the horizontal axis representing time and the vertical axis representing the output signal state (ON state or OFF state).

[0084] The sheet sensor 150 consists of a photointerrupter and a flag (not shown), and is used to detect the sheet S1. The sheet sensor 150 outputs an ON signal indicating that the sheet is detected when the sheet S1 is in contact with the flag and the optical axis of the photointerrupter is blocked. The sheet sensor 150 also outputs an OFF signal indicating that the sheet is not detected when the sheet S1 is not in contact with the flag and the optical axis of the photointerrupter is not blocked.

[0085] The sheet sensor 150 is positioned upstream of the sheet separation unit (separation position 22A) in the sheet transport direction, and is positioned to detect the presence or absence of a sheet near the separation position 22A. Thus, the sheet sensor 150 is an example of a detection unit that detects the transported recording material (sheet). In this embodiment, the detection unit (sheet sensor 150) is positioned upstream of the sheet separation unit (feed roller 21 and separation roller 22) in the sheet transport direction. The control unit 70 (CPU 71) monitors the output signal of the sheet sensor 150 via the IO port 75 and the system bus 74. When the output signal of the sheet sensor 150 is ON, the control unit 70 can determine that the top sheet S1 is near the separation position 22A. When the output signal is OFF, the control unit 70 can determine that the top sheet S1 is not near the separation position 22A.

[0086] More specifically, the sheet sensor 150 may be placed within the detection section TD described in the first embodiment. For example, as in the first embodiment, the section from the midpoint position 28 to the separation position 22A in the sheet transport direction is set as the detection section TD. In this case, the control unit 70 can count the sheets detected by the sheet sensor 150 at the start timing of sheet feeding as sheets whose paper feeding start position is within the detection section TD (within the notification section). As in the first embodiment, the control unit 70 has a sheet counter for counting sheets within the detection section TD (sheets whose paper feeding start position is within the detection section TD).

[0087] Next, the process performed by the control unit 70 (CPU 71) to determine whether multiple sheets are located near (entered by) the separation position 22A will be explained using the example in Figure 14. In this embodiment, the process described below is performed as the process in S102 to S104 of the processing procedure shown in Figure 11.

[0088] In the example in Figure 14, P1 to P5 indicate the timing (paper feed start timing) when the CPU 71 sends (outputs) a control signal to the paper feed clutch 29 to start paper feeding. For example, P1 corresponds to the first sheet, and P5 corresponds to the fifth sheet. When the top sheet S1 is in the position shown in Figure 13 (cassette position 10B in Figure 7), as shown in Figure 14, the output signal of the sheet sensor 150 is OFF at the paper feed start timing P1. Subsequently, when the top sheet S1 is fed, the sheet sensor 150 outputs an ON signal from the time it detects the leading edge of the sheet S1 until the trailing edge passes the position of the sheet sensor 150. When the trailing edge of the sheet S1 passes the position of the sheet sensor 150, the output signal of the sheet sensor 150 switches from ON to OFF.

[0089] In this embodiment, the CPU 71 determines whether the paper feed start position of the fed sheet is within the detection interval TD based on the output signal of the sheet sensor 150 at the paper feed start timing (P1 to P5) of the sheet. If the output signal of the sheet sensor 150 is ON at each paper feed start timing (the sheet is detected), the CPU 71 determines that the paper feed start position of the fed sheet is within the detection interval TD. In this case, the CPU 71 performs a process to increase the count value of the sheet counter by 1 (S105). On the other hand, if the output signal of the sheet sensor 150 is OFF at each paper feed start timing (the sheet is not detected), the CPU 71 determines that the paper feed start position of the fed sheet is outside the detection interval TD. In this case, the CPU 71 performs a process to decrease the count value of the sheet counter by 1 (if the count value is 0, it remains 0) (S106).

[0090] In the example shown in Figure 14, the output signal of the sheet sensor 150 is OFF at each of the paper feed start timings P1 to P3. Therefore, the CPU 71 determines that the paper feed start position for the first to third sheets that have been fed is outside the detection interval TD, and decreases the count value of the sheet counter by 1 (S106).

[0091] Next, consider the case where, when the third sheet is fed, multiple sheets enter the paper feed cassette 10 near separation position A. In this case, even if the trailing edge of the third sheet (topmost sheet S1) passes the position of the sheet sensor 150, the next, fourth sheet is already present at the position of the sheet sensor 150. In this case, as shown in Figure 14, the output signal of the sheet sensor 150 at the paper feed start timing P4 is ON. Therefore, the CPU 71 determines that the paper feed start position of the fed fourth sheet is within the detection section TD and increases the count value of the sheet counter by 1 (S105).

[0092] In this example, even after the trailing edge of the fourth sheet (topmost sheet S1) has passed the position of the sheet sensor 150, the next fifth sheet is already located at the position of the sheet sensor 150. In this case, as shown in Figure 14, the output signal of the sheet sensor 150 at the paper feed start timing P5 is ON. Therefore, the CPU 71 determines that the paper feed start position of the fed fifth sheet is within the detection section TD and increases the count value of the sheet counter by 1 (S105).

[0093] Subsequently, the CPU 71, similar to the first embodiment, determines whether multiple sheets are near the separation position 22A (in the detection section TD) based on the count value of the sheet counter, and performs processing to report information based on the determination result (S107~S109).

[0094] As described above, in this embodiment, each time the pick roller 20 performs a paper feeding operation, the control unit 70 (CPU 71) counts the sheets whose paper feeding start position is within the detection section TD based on the detection result from the sheet sensor 150, and determines whether or not there are multiple sheets in the detection section TD based on the obtained count value. According to this embodiment, with a simple configuration similar to the first embodiment, it becomes possible to determine whether multiple sheets have entered the vicinity of the separation position 22A (that the paper feeding operation is being performed with multiple sheets near the sheet separation section) and to notify information based on the determination result.

[0095] [Third Embodiment] As a third embodiment, a modification of the second embodiment will be described. The following description will omit explanations of parts common to the first and second embodiments.

[0096] The image forming apparatus 100 of this embodiment has the same configuration as in the second embodiment, as shown in Figure 13, for the sheet feeding configuration. However, in this embodiment, a thickness sensor capable of detecting the thickness of a sheet is used as the sheet sensor 150. The sheet sensor 150 is configured to detect the thickness of a sheet using ultrasound. Similar to the second embodiment, the sheet sensor 150 is placed within the detection section TD (within a predetermined section) and is configured to output information indicating the thickness of the sheet at the detection position within the detection section TD as detection information. If there is no sheet at the detection position within the detection section TD, the sheet sensor 150 outputs detection information indicating that the thickness is 0. Based on the detection information output by the sheet sensor 150, it is possible to determine the thickness of the sheet at the detection position and also determine how many sheets are at the detection position.

[0097] The control unit 70 (CPU 71) monitors the output signal of the sheet sensor 150 via the I / O port 75 and the system bus 74. Based on the detection information contained in the output signal from the sheet sensor 150 at the start timing of sheet feeding, the control unit 70 determines whether there are multiple sheets within the detection section TD. For example, the control unit 70 may compare the sheet thickness indicated by the detection information with a threshold value for determination, and if the thickness is greater than or equal to the threshold value, it may determine that there are multiple sheets within the detection section TD.

[0098] Thus, in this embodiment, without using the sheet counter count value described in the first and second embodiments, a determination result of whether or not there are multiple sheets within the detection section TD can be obtained based on the detection information of the sheet sensor 150. The control unit 70 (CPU 71) performs processing to broadcast information based on the determination result, similar to the first and second embodiments.

[0099] According to this embodiment, similar to the first and second embodiments, it becomes possible to determine whether the image forming apparatus 100 is performing a paper feeding operation with multiple sheets near the sheet separation section and to notify information based on the determination result. This makes it possible to appropriately identify the cause of any malfunctions that occur in the image forming apparatus due to multiple sheets entering the vicinity of the sheet separation section.

[0100] In this embodiment, the above determination is made using detection information from the sheet sensor 150 at the start of paper feeding, but it is not limited to this, and for example, the same determination may be made using detection information from the sheet sensor 150 when a jam occurs. This makes it possible to quickly notify the user or administrator that multiple sheets have entered the separation section as the cause of the jam.

[0101] [Fourth embodiment] In the fourth embodiment, a rotation detection unit including an encoder is placed within the detection section TD, and an example is described in which it is determined whether or not multiple sheets are near the separation position 22A based on the detection result from the rotation detection unit. In the following, the explanation of parts common to the first embodiment will be omitted. In the following, the explanation of parts common to the first embodiment will be omitted.

[0102] Figure 15(A) is a cross-sectional view showing an example of the configuration related to sheet feeding in the image forming apparatus 100 of this embodiment. The image forming apparatus 100 of this embodiment includes a rotation detection unit 151 located upstream of the separation unit, instead of a transport sensor 27 (Figure 2) located downstream of the separation unit, which includes the feed roller 21 and the separation roller 22, in the sheet transport direction. Figure 15(B) is a schematic diagram showing an example of the configuration of the rotation detection unit 151. The rotation detection unit 151 includes an encoder 152 and a photointerrupter 153.

[0103] The encoder 152 has a closed portion 152A and a slit portion (opening) 152B. When the closed portion 152A of the encoder 152 aligns with the optical axis of the photointerrupter 153 as the encoder 152 rotates, the photointerrupter 153 outputs a signal indicating a light-blocking state. Also, when the slit portion 152B of the encoder 152 aligns with the optical axis of the photointerrupter 153, the photointerrupter 153 outputs a signal indicating a light-transmitting state.

[0104] The rotation detection unit 151 is positioned upstream of the separation unit (separation position 22A) in the sheet transport direction, and is positioned to detect the sheet near the separation position 22A. More specifically, the rotation detection unit 151 may be positioned within the detection section TD described in the first embodiment. For example, as in the first embodiment, the section from the midpoint position 28 to the separation position 22A in the sheet transport direction is set as the detection section TD. In this embodiment, the rotation detection unit 151 is an example of a detection unit that is positioned within the notification section (within the detection section TD), includes an encoder 152 that is in contact with the lower surface of the recording material (sheet), and is configured to rotate in accordance with the transport of the recording material it is in contact with, and outputs a signal indicating whether or not the encoder is rotating.

[0105] Figure 16 shows an example of the operation of the encoder 152 when a sheet is reached. Figure 16(A) shows the state when only one sheet (the top sheet S1) is fed by the sheet feeding operation and reaches the position of the encoder 152 within the detection section TD. In this case, the encoder 152 rotates as the sheet moves. As a result of the rotation of the encoder 152, the closed portion 152A and the slit portion 152B alternately align with the optical axis of the photointerrupter 153, causing the photointerrupter 153 to output a signal that alternately switches between a light-transmitting state and a light-blocking state.

[0106] On the other hand, Figure 16(B) shows the state in which multiple sheets (the top sheet S1 and the other sheets S4 and S5) have reached the position of the encoder 152 within the detection section TD. Sheet S4 is the sheet in contact with the encoder 152. Sheet S5 is the sheet directly above sheet S4. In this case, the separation roller 22 (Figure 15) is stopped, so the transport of sheets S4 and S5 is stopped, and only the top sheet S1 is being transported by the feed roller 21 (Figure 15). This is because, as described above, the rotational torque of the torque limiter built into the separation roller 22 is set so that the separation roller 22 rotates when sheets are transported one by one, but does not rotate when multiple sheets are transported.

[0107] In this way, because the transport (movement) of the sheet S4 in contact with the encoder 152 has stopped, the encoder 152 has stopped without rotating. As a result, the photointerrupter 153 does not output a signal that alternates between a light-transmitting state and a light-blocking state, but instead outputs a constant signal indicating either a light-transmitting state or a light-blocking state.

[0108] Figure 17 shows an example of the state indicated by the output signal of the rotation detection unit 151 (photo interrupter 153), with the horizontal axis representing time and the vertical axis representing the state indicated by the output signal (light-shielding state or light-transmitting state). Below, using Figure 17, an example of the operation of the rotation detection unit 151 when a sheet is actually fed will be described.

[0109] In Figure 17, the paper feed start timings P1 to P4, as in Figure 14, indicate the timing when the CPU 71 sends (outputs) a control signal to the paper feed clutch 29 to start paper feeding. The periods int1 to int4 are predetermined periods starting from each paper feed timing P1 to P4, and are set as rotation detection periods to detect whether or not the encoder 152 is rotating. As an example, each rotation detection period is set as the time from each paper feed start timing until a region of 1 / 3 of the length in the transport direction on the uppermost sheet S1 passes the position of the encoder 152.

[0110] In this embodiment, the control unit 70 (CPU 71) determines whether the encoder 152 is rotating based on the output signal of the rotation detection unit 151 (photo interrupter 153) during each rotation detection period. That is, the CPU 71 determines whether multiple sheets have entered the detection section TD based on the output signal of the rotation detection unit 151 during each rotation detection period.

[0111] In the example shown in Figure 17, the first to third sheets are fed starting as the top sheet S1 at the position shown in Figure 15 (cassette position 10B in Figure 7). First, feeding of the top sheet S1 begins at the feeding start timing P1, and when the top sheet S1 (its leading edge) reaches the rotation detection unit 151, the encoder 152 starts to rotate. Subsequently, while the top sheet S1 is transported in the detection section TD, the rotation detection unit 151 (photo interrupter 153) outputs a signal that alternates between a light-transmitting state and a light-blocking state, in accordance with the rotation of the encoder 152 in contact with the sheet S1. In this way, the rotation detection unit 151 outputs a signal indicating that the encoder 152 is rotating. For example, if the output signal of the rotation detection unit 151 in the rotation detection period int1 repeats between a light-transmitting state and a light-blocking state a predetermined number of times, the CPU 71 determines that the feeding start position for the first sheet is outside the detection section TD. Furthermore, the CPU 71 decrements the count value of the sheet counter mentioned above by 1 (S106 in Figure 11). In the example in Figure 17, the same process is followed for the second and third sheets.

[0112] Next, consider the case where, when the third sheet is fed, multiple sheets enter the vicinity of separation position A from the paper feed cassette 10. In this case, after the third sheet (top sheet S1) is transported, at the paper feed start timing P4, multiple sheets, including the next fourth sheet (top sheet S1), are within the detection section TD (entered), and the leading edge of the top sheet S1 has reached the separation position 22A. In this case, as described above, even if the top sheet S1 is transported by the feed roller 21, the transport of the other sheets is stopped, so the encoder 152 does not rotate in the rotation detection section int4. For this reason, the rotation detection unit 151 (photo interrupter 153) outputs a constant signal indicating a light-transmitting or light-blocking state. Thus, the rotation detection unit 151 outputs a signal indicating that the encoder 152 is not rotating. For example, if the output signal of the rotation detection unit 151 during the rotation detection period int4 is constant, the CPU 71 determines that the paper feed start position for the fourth sheet is within the detection section TD. Furthermore, the CPU 71 increments the count value of the sheet counter mentioned above by 1 (S105 in Figure 11).

[0113] Subsequently, the CPU 71, similar to the first embodiment, determines whether multiple sheets are near the separation position 22A (in the detection section TD) based on the count value of the sheet counter, and performs processing to report information based on the determination result (S107~S109 in Figure 11).

[0114] Thus, according to this embodiment, it is possible to determine, with a simple configuration using an encoder, that multiple sheets are positioned near the separation position 22A (i.e., that the paper feeding operation is being performed with multiple sheets positioned near the sheet separation section). Furthermore, it becomes possible to notify information based on the determination result. As a result, similar to the first embodiment, if a malfunction occurs in the image forming apparatus 100 due to multiple sheets being positioned near the sheet separation section, it becomes possible to appropriately identify the cause.

[0115] [Fifth Example] In the fifth embodiment, a rotation detection unit is provided on the separation roller 22 to detect the rotation of the separation roller 22, and an example is described in which it is determined whether or not multiple sheets are positioned near the separation position 22A based on the detection result by the rotation detection unit. In the following, the explanation of parts common to the first embodiment will be omitted.

[0116] Figure 18 is a cross-sectional view showing an example of the configuration related to sheet feeding in the image forming apparatus 100 of this embodiment. As shown in Figure 18, the rotation detection unit 151 is provided on the separation roller 22 and is configured to detect the sheet based on the rotation (or absence of rotation) of the separation roller 22. The rotation detection unit 151 has the same configuration as the rotation detection unit 151 of the fourth embodiment, that is, it includes an encoder 152 and a photointerrupter 153. As described in the first embodiment, the separation roller 22 has a built-in torque limiter. The rotation torque of the torque limiter is preset so that the separation roller 22 rotates when sheets are conveyed one at a time, but does not rotate when multiple sheets are conveyed.

[0117] Figure 19 shows an example of the operation of the rotation detection unit 151 when the sheet reaches the separation position 22A. In this embodiment, the change in the output signal of the rotation detection unit 151 (photo interrupter 153) accompanying the sheet feeding and transport operations in the image forming apparatus 100 is the same as in Figure 17 of the third embodiment.

[0118] Figure 19(A) shows the case where one sheet (the top sheet S1) is fed by the sheet feeding operation and enters the separation position 22A. This corresponds to the case where the first to third sheets enter the separation position 22A in the example in Figure 17. Figure 19(B) shows the case where the top sheet S1 enters the separation position 22A, and several other sheets (sheets S4 and S5) have entered the vicinity of the separation position 22A (within the detection section TD). This corresponds to the case where the fourth sheet enters the separation position 22A in the example in Figure 17.

[0119] In the example in Figure 17, feeding of one sheet (top sheet S1) begins at the paper feed start timing P1. When the sheet reaches the separation position 22A, the separation roller 22 rotates while the sheet is transported by the feed roller 21, as shown in Figure 19(A). During this time, the rotation detection unit 151 (photo interrupter 153) outputs a signal that alternates between a light-transmitting state and a light-blocking state. For example, if the output signal of the rotation detection unit 151 during the rotation detection period int1 repeats between the light-transmitting state and the light-blocking state a predetermined number of times, the CPU 71 determines that the paper feed start position for the first sheet is outside the detection section TD. Furthermore, the CPU 71 decreases the count value of the sheet counter by 1 (S106 in Figure 11). In the example in Figure 17, the same applies to the second and third sheets.

[0120] Subsequently, when the third sheet is fed, we assume a scenario where multiple sheets enter the paper feed cassette 10 near separation position A. In this case, with the leading edge of the next fourth sheet (top sheet S1) reaching separation position 22A, the feeding of that sheet begins at the paper feed start timing P4. At this time, as described above, while the top sheet S1 is being transported by the feed roller 21, the rotation of the separation roller 22 stops, thereby stopping the transport of the other sheets. With the rotation of the separation roller 22 stopped in this way, the rotation detection unit 151 (photo interrupter 153) outputs a constant signal indicating a light-transmitting or light-blocking state. For example, if the output signal of the rotation detection unit 151 during the rotation detection period int4 is constant, the CPU 71 determines that the paper feed start position for the fourth sheet is within the detection section TD. Furthermore, the CPU 71 increments the count value of the sheet counter by 1 (S105 in Figure 11).

[0121] Subsequently, the CPU 71, similar to the first embodiment, determines whether multiple sheets are near the separation position 22A (in the detection section TD) based on the count value of the sheet counter, and performs processing to report information based on the determination result (S107~S109 in Figure 11).

[0122] Thus, according to this embodiment, similar to the fourth embodiment, it is possible to determine that multiple sheets are positioned near the separation position 22A using a simple configuration that utilizes an encoder.

[0123] [Sixth Example] In the sixth embodiment, we will describe an example in which the torque of the drive motor that rotates the pick roller 20 and the feed roller 21 (separation section) is measured, and based on the measurement results, it is determined whether or not multiple sheets are positioned near the separation position 22A. In the following, we will omit the explanation of parts that are common with the first embodiment.

[0124] Figures 20 and 21 are a cross-sectional view and a top view, respectively, showing an example configuration related to sheet feeding in the image forming apparatus 100 of this embodiment. As shown in Figure 20, the image forming apparatus 100 of this embodiment does not include the transport sensor 27 of the first embodiment, nor the rotation detection unit 151 of the fourth and fifth embodiments. The drive motor 32 shown in Figure 21 rotates the pick roller 20 and the feed roller 21 via a drive train 31 including a paper feed clutch 29. The drive motor 32 is equipped with a torque sensor (not shown) capable of measuring the torque on the motor shaft of the drive motor 32. The control unit 70 (CPU 71) can acquire the measurement result from the torque sensor via the IO port 75 and the system bus 74. In this embodiment, the torque sensor is an example of a detection unit configured to detect the recording material (sheet) by detecting the torque required to rotate the drive motor that rotates the separation unit.

[0125] Figure 22 shows an example of the time variation of the torque of the drive motor 32, with the horizontal axis representing the page count and the vertical axis representing the measured torque of the drive motor 32. In this figure, the maximum torque measured during the rotation detection period int1, starting from the paper feed start timing P1 shown in Figure 17, is shown for each page count.

[0126] As shown in Figure 19(A), when one sheet has entered the separation position 22A, the feed roller 21 will rotate the separation roller 22. For this reason, the torque of the drive motor 32 needs to be greater than the torque of the torque limiter built into the separation roller 22. In this case, as shown in Figure 22, the torque of the drive motor 32 will be a relatively large value.

[0127] As shown in Figure 19(B), when the top sheet S1 enters the separation position 22A and several other sheets (sheets S4 and S5) have entered the vicinity of the separation position 22A (within the detection section TD), the feed roller 21 does not rotate the separation roller 22. For this reason, the torque of the drive motor 32 does not need to be greater than the torque of the torque limiter built into the separation roller 22. In this case, as shown in Figure 22, the torque of the drive motor 32 becomes a relatively small value.

[0128] In this embodiment, the control unit 70 (CPU 71) acquires measurement results from the torque sensor of the drive motor 32 each time a sheet feeding operation is performed, and determines whether the starting position of the fed sheet is within the detection interval TD based on the acquired measurement results. For example, the determination is made based on the comparison result of the measured torque with a predetermined threshold. This threshold can be set in advance as a value between the measured torque of the drive motor 32 when the separation roller 22 is rotating and the measured torque of the drive motor 32 when the separation roller 22 is not rotating.

[0129] Specifically, if the measured torque is below the threshold, the CPU 71 determines that the starting position of the fed sheet is within the detection interval TD. In this case, the CPU 71 performs a process to increase the count value of the sheet counter by 1 (S105 in Figure 11). On the other hand, if the measured torque is above the threshold, the CPU 71 determines that the starting position of the fed sheet is outside the detection interval TD. In this case, the CPU 71 performs a process to decrease the count value of the sheet counter by 1 (if the count value is 0, it remains 0) (S106 in Figure 11).

[0130] Subsequently, the CPU 71, similar to the first embodiment, determines whether multiple sheets are near the separation position 22A (in the detection section TD) based on the count value of the sheet counter, and performs processing to report information based on the determination result (S107~S109 in Figure 11).

[0131] Thus, in this embodiment, by having a configuration that allows the torque of the drive motor 32 to be measured, it becomes possible to determine whether the paper feeding operation is being performed with multiple sheets near the sheet separation section without using the transport sensor 27, and to notify information based on the determination result.

[0132] [Other examples] Each of the embodiments described above can be modified in various ways. Figure 23 is a cross-sectional view showing an example of the configuration related to sheet feeding in an modified image forming apparatus 100. In this example, the pick roller 20 and feed roller 21 in the first to fifth embodiments are provided as a single roller (pick-feed roller 33). The pick-feed roller 33 is configured to contact the uppermost sheet S1 of the sheet bundle S0 housed in the paper feed cassette 10, and also to contact the separation roller 22. The pick roller position 33A shown in Figure 23 is the position where the pick-feed roller 33 contacts the uppermost sheet S1. The separation position 22A corresponds to the contact area where the pick-feed roller 33 and the separation roller 22 contact, and is the position where the uppermost sheet S1 is separated from the other sheets.

[0133] In the configuration example shown in Figure 23, the detection section TD is set to be the section upstream of the sheet separation section (separation position 22A) in the sheet transport direction, with the separation position 22A as the endpoint, similar to the embodiments described above. As an example, similar to the embodiments described above, the section from the midpoint of the line segment connecting the pick roller position 33A and the separation position 22A to the separation position 22A is set as the detection section TD. By setting the detection section TD in this way, the same judgment processing and notification processing as in the embodiments described above can be achieved even in a configuration using the pick feed roller 33, and the same effects can be obtained.

[0134] Furthermore, although the above embodiments illustrate an image forming apparatus 100 configured as an electrophotographic laser beam printer, the embodiments can also be applied to image forming apparatuses such as printers or copiers employing other printing methods (e.g., inkjet methods).

[0135] The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0136] The disclosures herein include the following image forming systems and information processing devices. (Item 1) An image forming system comprising an image forming apparatus, an information processing apparatus capable of communicating with the image forming apparatus, and a display device capable of displaying information, The image forming apparatus is A storage section for storing recording materials, A paper feeding section is provided which has a paper feeding contact section that contacts the recording material housed in the storage section, and which feeds the recording material that has come into contact with the paper feeding contact section, A separation unit provided downstream of the paper feeding unit in the transport direction in which the paper feeding unit transports the recording material, and comprising a separation contact portion that contacts the recording material fed by the paper feeding unit, the separation unit separates the recording material into individual sheets for transport, A detection unit for detecting the recording material being transported, Equipped with, If the information based on the detection result of the detection unit indicates that multiple recording materials are simultaneously located in the notification section, the information processing device shall notify the display device to display information indicating that multiple recording materials are in the notification section. The notification section is the section in the transport direction that is downstream from the midpoint of the line segment connecting the paper feed contact section and the separation contact section, and upstream from the separation contact section. An image forming system characterized by the following: (Item 2) The detection unit is positioned downstream of the separation unit in the transport direction. The image forming apparatus further includes a measuring unit that measures the time from the start timing of paper feeding of the recording material to the timing of detection of the recording material by the detection unit. When the measurement result of the measurement unit indicates that multiple recording materials are simultaneously located within the notification section, the information processing device notifies the user by displaying information on the display device indicating that multiple recording materials are within the notification section. The image forming system according to item 1, characterized by the features described above. (Item 3) The information processing device counts the recording materials whose paper feed start position is within the notification section based on the measurement results of the measurement unit, and determines whether multiple sheets of the recording materials are within the notification section based on the obtained count value. The image forming system according to item 2, characterized in that it is a system that forms images as described in item 2. (Item 4) The information processing device determines that multiple recording materials are in the notification section when the count value is equal to or greater than a threshold. The image forming system according to item 3, characterized by the features described above. (Item 5) The detection unit is positioned upstream of the separation unit in the transport direction. The information processing device counts the recording materials whose paper feed start position is within the notification section based on the detection result of the detection unit, and determines whether multiple sheets of the recording materials are within the notification section based on the obtained count value. The image forming system according to item 1, characterized by the features described above. (Item 6) The detection unit is located within the notification section. The information processing device counts the recording material detected by the detection unit at the timing of the start of paper feeding of the recording material as recording material whose paper feeding start position is within the notification section. The image forming system described in item 5, characterized by the features described herein. (Item 7) The detection unit is a sensor located within the notification section and capable of detecting the thickness of the recording material. The information processing device determines whether multiple sheets of the recording material are in the notification section based on the detection information from the sensor at the timing of the start of paper feeding of the recording material. The image forming system according to item 1, characterized by the features described above. (Item 8) The detection unit includes an encoder positioned within the notification section, in contact with the lower surface of the recording material, and configured to rotate in accordance with the transport of the recording material it is in contact with, and outputs a signal indicating whether or not the encoder is rotating. The information processing device counts the number of recording materials whose paper feed start position is within the notification section based on the output signal of the detection unit during a predetermined detection period, and determines whether or not multiple sheets of the recording material are within the notification section based on the obtained count value. The image forming system according to item 1, characterized by the features described above. (Item 9) The separation unit has a separation roller configured to rotate when one recording material arrives and to stop rotating when multiple recording materials arrive. The aforementioned information processing device is If the output signal during the predetermined detection period indicates that the encoder is not rotating, the count value is incremented by 1. If the output signal during the predetermined detection period indicates that the encoder is rotating, the count value is decreased by 1. The image forming system according to item 8, characterized by the features described above. (Item 10) The separation unit comprises a separation roller configured to rotate when one recording material arrives and to stop rotating when multiple recording materials arrive, and the detection unit. The detection unit is configured to detect the recording material based on whether or not the separation roller is rotating. The image forming system according to item 1, characterized by the features described above. (Item 11) The detection unit outputs a signal indicating whether or not the separation roller is rotating. The information processing device counts the number of recording materials whose paper feed start position is within the notification section based on the output signal of the detection unit during a predetermined detection period, and determines whether or not multiple sheets of the recording material are within the notification section based on the obtained count value. The image forming system according to item 10, characterized by the features described above. (Item 12) The aforementioned information processing device is If the output signal during the predetermined detection period indicates that the separation roller is not rotating, the count value is increased by 1. If the output signal during the predetermined detection period indicates that the separation roller is rotating, the count value is decreased by 1. The image forming system according to item 11, characterized by the features described herein. (Item 13) The separation unit has a separation roller configured to rotate when one recording material arrives and to stop rotating when multiple recording materials arrive. The detection unit is configured to detect the recording material by detecting the torque required to rotate the drive motor that rotates the separation unit. The image forming system according to item 1, characterized by the features described above. (Item 14) The information processing device counts the recording material whose paper feed start position is within the notification section based on the torque detected by the detection unit, and determines whether multiple sheets of the recording material are within the notification section based on the obtained count value. The image forming system according to item 13, characterized by the features described herein. (Item 15) When the information processing device, based on the detection result of the detection unit, indicates that multiple recording materials are simultaneously located in the notification section, and a jam occurs in which the recording materials are not transported downstream from the separation unit in the transport direction, the device notifies that multiple recording materials are in the notification section as the cause of the jam. An image forming system according to any one of items 1 to 14, characterized by the features described above. (Item 16) The information processing device provides information for handling the recording material stored in the storage unit. An image forming system according to any one of items 1 to 15, characterized by the features described herein. (Item 17) The information processing device broadcasts a message prompting the replacement or cleaning of the double-feed prevention member provided in the housing section. The image forming system according to item 16, characterized by the features described herein. (Item 18) When the number of times the information processing device has determined that multiple recording materials are in the notification section reaches a predetermined number of times, it notifies that there is a tendency for multiple recording materials to be in the notification section at the timing when the paper feeding of the recording materials begins. An image forming system according to any one of items 1 to 17, characterized by the features described herein. (Item 19) An information processing apparatus capable of communicating with an image forming apparatus, comprising: a storage section for storing recording material; a paper feeding section that contacts the recording material stored in the storage section and feeds the recording material that has come into contact with the paper feeding section; a separation section provided downstream of the paper feeding section in the transport direction in which the paper feeding section transports the recording material and having a separation contact section that contacts the recording material fed by the paper feeding section, the separation section for separating and transporting the recording material into individual sheets; and a detection section for detecting the transported recording material. The system includes a control unit that, when information received from the image forming apparatus based on the detection result of the detection unit indicates that multiple recording materials are simultaneously located in the notification section, notifies the system by displaying information on a display device indicating that multiple recording materials are in the notification section. The notification section is the section in the transport direction that is downstream from the midpoint of the line segment connecting the paper feed contact section and the separation contact section, and upstream from the separation contact section. An information processing device characterized by the following: (Item 20) The detection unit is positioned downstream of the separation unit in the transport direction. The image forming apparatus further includes a measuring unit that measures the time from the start timing of paper feeding of the recording material to the timing of detection of the recording material by the detection unit. When the measurement result from the measurement unit indicates that multiple recording materials are simultaneously located within the notification section, the control unit notifies the system by displaying information on the display device indicating that multiple recording materials are within the notification section. The information processing device described in item 19, characterized by the features described herein. (Item 21) The control unit counts the recording materials whose paper feed start position is within the notification section based on the measurement results of the measurement unit, and determines whether multiple sheets of the recording materials are within the notification section based on the obtained count value. The information processing device described in item 20, characterized by the features described herein. (Item 22) The control unit determines that multiple recording materials are in the notification section when the count value is equal to or greater than a threshold. The information processing device described in item 21, characterized by the features described herein. (Item 23) The detection unit is positioned upstream of the separation unit in the transport direction. The control unit counts the recording materials whose paper feed start position is within the notification section based on the detection result of the detection unit, and determines whether multiple sheets of the recording materials are within the notification section based on the obtained count value. The information processing device described in item 19, characterized by the features described herein. (Item 24) The detection unit is located within the notification section. The control unit counts the recording material detected by the detection unit at the timing of the start of paper feeding of the recording material as recording material whose paper feeding start position is within the notification section. The information processing device described in item 23, characterized by the features described herein. (Item 25) The detection unit is a sensor located within the notification section and capable of detecting the thickness of the recording material. The control unit determines whether multiple sheets of the recording material are in the notification section based on the detection information from the sensor at the timing of the start of paper feeding of the recording material. The information processing device described in item 19, characterized by the features described herein. (Item 26) The detection unit includes an encoder positioned within the notification section, in contact with the lower surface of the recording material, and configured to rotate in accordance with the transport of the recording material it is in contact with, and outputs a signal indicating whether or not the encoder is rotating. The control unit counts the number of recording materials whose paper feed start position is within the notification section based on the output signal of the detection unit during a predetermined detection period, and determines whether multiple sheets of the recording material are within the notification section based on the obtained count value. The information processing device described in item 19, characterized by the features described herein. (Item 27) The separation unit has a separation roller configured to rotate when one recording material arrives and to stop rotating when multiple recording materials arrive. The control unit, If the output signal during the predetermined detection period indicates that the encoder is not rotating, the count value is incremented by 1. If the output signal during the predetermined detection period indicates that the encoder is rotating, the count value is decreased by 1. The information processing device described in item 26, characterized by the features described herein. (Item 28) The separation unit comprises a separation roller configured to rotate when one recording material arrives and to stop rotating when multiple recording materials arrive, and the detection unit. The detection unit is configured to detect the recording material based on whether or not the separation roller is rotating. The information processing device described in item 19, characterized by the features described herein. (Item 29) The detection unit outputs a signal indicating whether or not the separation roller is rotating. The control unit counts the number of recording materials whose paper feed start position is within the notification section based on the output signal of the detection unit during a predetermined detection period, and determines whether multiple sheets of the recording material are within the notification section based on the obtained count value. The information processing device described in item 28, characterized by the features described herein. (Item 30) The control unit, If the output signal during the predetermined detection period indicates that the separation roller is not rotating, the count value is increased by 1. If the output signal during the predetermined detection period indicates that the separation roller is rotating, the count value is decreased by 1. The information processing device described in item 29, characterized by the features described herein. (Item 31) The separation unit has a separation roller configured to rotate when one recording material arrives and to stop rotating when multiple recording materials arrive. The detection unit is configured to detect the recording material by detecting the torque required to rotate the drive motor that rotates the separation unit. The information processing device described in item 19, characterized by the features described herein. (Item 32) The control unit counts the recording materials whose paper feed start position is within the notification section based on the torque detected by the detection unit, and determines whether multiple sheets of the recording materials are within the notification section based on the obtained count value. The information processing device described in item 31, characterized by the features described herein. (Item 33) When the information based on the detection result of the detection unit indicates that multiple recording materials are simultaneously located in the notification section, and a jam occurs in which the recording materials are not transported downstream from the separation unit in the transport direction, the control unit notifies that the presence of multiple recording materials in the notification section is the cause of the jam. An information processing device according to any one of items 19 to 32, characterized in that it is an information processing device. (Item 34) The control unit provides information for handling the recording material stored in the storage unit. An information processing device according to any one of items 19 to 33, characterized by the features described herein. (Item 35) The control unit broadcasts a message prompting the replacement or cleaning of the double-feed prevention member provided in the housing section. The information processing device described in item 34, characterized by the features described herein. (Item 36) When the control unit determines that multiple recording materials are in the notification section for a predetermined number of times, it notifies that there is a tendency for multiple recording materials to be in the notification section at the timing of the start of paper feeding of the recording materials. An information processing device according to any one of items 19 to 35, characterized by the features described herein.

[0137] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention. [Explanation of symbols]

[0138] 100: Image forming apparatus, 10: Paper feed cassette, 20: Pick roller, 21: Feed roller, 22: Separation roller, 70: Control unit, 71: CPU

Claims

1. An image forming system comprising an image forming apparatus, an information processing apparatus capable of communicating with the image forming apparatus, and a display device capable of displaying information, The image forming apparatus is A storage section for storing recording materials, A paper feeding section is provided which has a paper feeding contact section that contacts the recording material housed in the storage section, and which feeds the recording material that has come into contact with the paper feeding contact section, A separation unit provided downstream of the paper feeding unit in the transport direction in which the paper feeding unit transports the recording material, and comprising a separation contact unit that contacts the recording material fed by the paper feeding unit, the separation unit separates the recording material into individual sheets for transport, A detection unit for detecting the recording material being transported, Equipped with, If the information based on the detection result of the detection unit indicates that multiple recording materials are simultaneously located in the notification section, the information processing device shall notify the display device to display information indicating that multiple recording materials are in the notification section. The notification section is the section in the transport direction that is downstream from the midpoint of the line segment connecting the paper feed contact section and the separation contact section, and upstream from the separation contact section. An image forming system characterized by the following features.

2. The detection unit is positioned downstream of the separation unit in the transport direction. The image forming apparatus further includes a measuring unit that measures the time from the start timing of paper feeding of the recording material to the timing of detection of the recording material by the detection unit. When the measurement result of the measurement unit indicates that multiple recording materials are simultaneously located within the notification section, the information processing device notifies the user by displaying information on the display device indicating that multiple recording materials are within the notification section. The image forming system according to claim 1.

3. The information processing device counts the recording materials whose paper feed start position is within the notification section based on the measurement results of the measurement unit, and determines whether multiple sheets of the recording materials are within the notification section based on the obtained count value. The image forming system according to claim 2, characterized in that it is as described above.

4. The information processing device determines that multiple recording materials are in the notification section when the count value is equal to or greater than a threshold. The image forming system according to claim 3, characterized in that it is as described above.

5. The detection unit is positioned upstream of the separation unit in the transport direction. The information processing device counts the recording materials whose paper feed start position is within the notification section based on the detection result of the detection unit, and determines whether multiple sheets of the recording materials are within the notification section based on the obtained count value. The image forming system according to claim 1.

6. The detection unit is located within the notification section. The information processing device counts the recording material detected by the detection unit at the timing of the start of paper feeding of the recording material as recording material whose paper feeding start position is within the notification section. The image forming system according to claim 5, characterized in that it is as described above.

7. The detection unit is a sensor located within the notification section and capable of detecting the thickness of the recording material. The information processing device determines whether multiple sheets of the recording material are in the notification section based on the detection information from the sensor at the timing of the start of paper feeding of the recording material. The image forming system according to claim 1.

8. The detection unit includes an encoder positioned within the notification section, in contact with the lower surface of the recording material, and configured to rotate in accordance with the transport of the recording material it is in contact with, and outputs a signal indicating whether or not the encoder is rotating. The information processing device counts the number of recording materials whose paper feed start position is within the notification section based on the output signal of the detection unit during a predetermined detection period, and determines whether or not multiple sheets of the recording material are within the notification section based on the obtained count value. The image forming system according to claim 1.

9. The separation unit has a separation roller configured to rotate when one recording material arrives and to stop rotating when multiple recording materials arrive. The aforementioned information processing device is If the output signal during the predetermined detection period indicates that the encoder is not rotating, the count value is incremented by 1. If the output signal during the predetermined detection period indicates that the encoder is rotating, the count value is decreased by 1. The image forming system according to claim 8.

10. The separation unit comprises a separation roller configured to rotate when one recording material arrives and to stop rotating when multiple recording materials arrive, and the detection unit. The detection unit is configured to detect the recording material based on whether or not the separation roller is rotating. The image forming system according to claim 1.

11. The detection unit outputs a signal indicating whether or not the separation roller is rotating. The information processing device counts the number of recording materials whose paper feed start position is within the notification section based on the output signal of the detection unit during a predetermined detection period, and determines whether or not multiple sheets of the recording material are within the notification section based on the obtained count value. The image forming system according to feature 10.

12. The aforementioned information processing device is If the output signal during the predetermined detection period indicates that the separation roller is not rotating, the count value is increased by 1. If the output signal during the predetermined detection period indicates that the separation roller is rotating, the count value is decreased by 1. The image forming system according to feature 11.

13. The separation unit has a separation roller configured to rotate when one recording material arrives and to stop rotating when multiple recording materials arrive. The detection unit is configured to detect the recording material by detecting the torque required to rotate the drive motor that rotates the separation unit. The image forming system according to claim 1.

14. The information processing device counts the recording material whose paper feed start position is within the notification section based on the torque detected by the detection unit, and determines whether multiple sheets of the recording material are within the notification section based on the obtained count value. The image forming system according to claim 13, characterized in that it is as described above.

15. When the information processing device, based on the detection result of the detection unit, indicates that multiple recording materials are simultaneously located in the notification section, and a jam occurs in which the recording materials are not transported downstream from the separation unit in the transport direction, the device notifies that multiple recording materials are in the notification section as the cause of the jam. The image forming system according to any one of claims 1 to 14.

16. The information processing device provides information for handling the recording material stored in the storage unit. The image forming system according to any one of claims 1 to 14.

17. The information processing device broadcasts a message prompting the replacement or cleaning of the double-feed prevention member provided in the housing section. The image forming system according to claim 16.

18. When the number of times the information processing device has determined that multiple recording materials are in the notification section reaches a predetermined number of times, it notifies that there is a tendency for multiple recording materials to be in the notification section at the timing when the paper feeding of the recording materials begins. The image forming system according to any one of claims 1 to 14.

19. An information processing apparatus capable of communicating with an image forming apparatus, comprising: a storage section for storing recording material; a paper feeding section that contacts the recording material stored in the storage section and feeds the recording material that has come into contact with the paper feeding section; a separation section provided downstream of the paper feeding section in the transport direction in which the paper feeding section transports the recording material and having a separation contact section that contacts the recording material fed by the paper feeding section, the separation section for separating and transporting the recording material into individual sheets; and a detection section for detecting the transported recording material, The system includes a control unit that, when information received from the image forming apparatus based on the detection result of the detection unit indicates that multiple recording materials are simultaneously located in the notification section, notifies by displaying information on a display device indicating that multiple recording materials are in the notification section. The notification section is the section in the transport direction that is downstream from the midpoint of the line segment connecting the paper feed contact section and the separation contact section, and upstream from the separation contact section. An information processing device characterized by the following:

20. The detection unit is positioned downstream of the separation unit in the transport direction. The image forming apparatus further includes a measuring unit that measures the time from the start timing of paper feeding of the recording material to the timing of detection of the recording material by the detection unit. When the measurement result from the measurement unit indicates that multiple recording materials are simultaneously located within the notification section, the control unit notifies the system by displaying information on the display device indicating that multiple recording materials are within the notification section. The information processing apparatus according to feature 19.

21. The control unit counts the recording materials whose paper feed start position is within the notification section based on the measurement results of the measurement unit, and determines whether multiple sheets of the recording materials are within the notification section based on the obtained count value. The information processing apparatus according to claim 20.

22. The control unit determines that multiple recording materials are in the notification section when the count value is equal to or greater than a threshold. The information processing apparatus according to feature 21.

23. The detection unit is positioned upstream of the separation unit in the transport direction. The control unit counts the recording materials whose paper feed start position is within the notification section based on the detection result of the detection unit, and determines whether multiple sheets of the recording materials are within the notification section based on the obtained count value. The information processing apparatus according to feature 19.

24. The detection unit is located within the notification section. The control unit counts the recording material detected by the detection unit at the timing of the start of paper feeding of the recording material as recording material whose paper feeding start position is within the notification section. The information processing apparatus according to feature 23.

25. The detection unit is a sensor located within the notification section and capable of detecting the thickness of the recording material. The control unit determines whether multiple sheets of the recording material are in the notification section based on the detection information from the sensor at the timing of the start of paper feeding of the recording material. The information processing apparatus according to feature 19.

26. The detection unit includes an encoder positioned within the notification section, in contact with the lower surface of the recording material, and configured to rotate in accordance with the transport of the recording material it is in contact with, and outputs a signal indicating whether or not the encoder is rotating. The control unit counts the number of recording materials whose paper feed start position is within the notification section based on the output signal of the detection unit during a predetermined detection period, and determines whether multiple sheets of the recording material are within the notification section based on the obtained count value. The information processing apparatus according to feature 19.

27. The separation unit has a separation roller configured to rotate when one recording material arrives and to stop rotating when multiple recording materials arrive. The control unit, If the output signal during the predetermined detection period indicates that the encoder is not rotating, the count value is incremented by 1. If the output signal during the predetermined detection period indicates that the encoder is rotating, the count value is decreased by 1. The information processing apparatus according to claim 26.

28. The separation unit comprises a separation roller configured to rotate when one recording material arrives and to stop rotating when multiple recording materials arrive, and the detection unit. The detection unit is configured to detect the recording material based on whether or not the separation roller is rotating. The information processing apparatus according to feature 19.

29. The detection unit outputs a signal indicating whether or not the separation roller is rotating. The control unit counts the number of recording materials whose paper feed start position is within the notification section based on the output signal of the detection unit during a predetermined detection period, and determines whether multiple sheets of the recording material are within the notification section based on the obtained count value. The information processing apparatus according to feature 28.

30. The control unit, If the output signal during the predetermined detection period indicates that the separation roller is not rotating, the count value is increased by 1. If the output signal during the predetermined detection period indicates that the separation roller is rotating, the count value is decreased by 1. The information processing apparatus according to feature 29.

31. The separation unit has a separation roller configured to rotate when one recording material arrives and to stop rotating when multiple recording materials arrive. The detection unit is configured to detect the recording material by detecting the torque required to rotate the drive motor that rotates the separation unit. The information processing apparatus according to feature 19.

32. The control unit counts the recording materials whose paper feed start position is within the notification section based on the torque detected by the detection unit, and determines whether multiple sheets of the recording materials are within the notification section based on the obtained count value. The information processing apparatus according to feature 31.

33. When the information based on the detection result of the detection unit indicates that multiple recording materials are simultaneously located in the notification section, and a jam occurs in which the recording materials are not transported downstream from the separation unit in the transport direction, the control unit notifies that the presence of multiple recording materials in the notification section is the cause of the jam. The information processing apparatus according to any one of claims 19 to 32.

34. The control unit provides information for handling the recording material stored in the storage unit. The information processing apparatus according to any one of claims 19 to 32.

35. The control unit broadcasts a message prompting the replacement or cleaning of the double-feed prevention member provided in the housing section. The information processing apparatus according to feature 34.

36. When the control unit determines that multiple recording materials are in the notification section for a predetermined number of times, it notifies that there is a tendency for multiple recording materials to be in the notification section at the timing of the start of paper feeding of the recording materials. The information processing apparatus according to any one of claims 19 to 32.

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