JP5868838B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and in particular, includes a main device and an accessory device detachably connected to the main device, and the accessory device is attached to the main device between the main device and the accessory device. The present invention relates to an image forming apparatus that performs communication at a sampling cycle specified in advance.

  2. Description of the Related Art Conventionally, image forming apparatuses such as printers, copiers, and multifunction machines that are used with optional devices (attached devices) such as paper feeding devices and post-processing devices are widely used. In an image forming apparatus in which such an optional device is mounted, a desired operation cannot be realized unless the image forming apparatus main body and the optional device operate in synchronization.

  For example, when the optional device is a paper feeder, it is necessary to drive the paper transport roller on the main body side in synchronization with the paper feeding from the paper feeder. Further, when the optional device is a post-processing device such as a punch or staple, it is necessary to drive the paper transport roller on the side of the post-processing device in synchronization with the discharge of the paper from the image forming apparatus main body. In either case, the paper can be transported by always driving the paper transport roller, but such an operation is contrary to the recent demand for energy saving and cannot be adopted.

  In order to realize the operation as described above, it is necessary to communicate information between the image forming apparatus main body and the optional device. That is, in the former case, it is necessary to provide a sensor that detects the passage of a sheet immediately before the sheet carry-out port of the sheet feeding device, and the image forming apparatus main body must always grasp the detection state of the sensor. In the latter case, it is necessary to provide a sensor for detecting the passage of the sheet immediately before the sheet carry-out port of the main body of the image forming apparatus, and the post-processing apparatus must always grasp the detection state of the sensor.

  In addition, in order for the image forming apparatus main body and the optional device to cooperate, not only the information for adjusting the conveyance timing as described above, but also the paper information such as the paper size and the paper orientation, For example, information indicating the device state such as the open / close state of the paper feed cassette and the open / close state of the device cover for the post-processing device needs to be communicated between the optional device and the image forming apparatus main body (for example, Patent Document 1). See ~ 4 etc.).

  As disclosed in Patent Documents 1 to 4, serial data is often used for data communication performed between the image forming apparatus main body and the optional device. By using serial data, regardless of the type of data to be communicated, one data input terminal and one data output terminal are arranged in each of the image forming apparatus main body and the optional device, and these are mutually connected. By connecting, data communication becomes possible.

  On the other hand, in such serial data communication, a communication abnormality (communication failure) in which data cannot be normally transmitted and received due to superposition of noise or the like may occur. When such a communication abnormality occurs, it becomes difficult for the devices using the serial data to cooperate. For this reason, various techniques relating to detection of whether or not a communication abnormality has occurred and data retransmission when a communication abnormality has occurred have been proposed (see, for example, Patent Documents 5 to 7).

JP 2006-039228 A JP 2004-240552 A JP 2001-106352 A Japanese Patent Laid-Open No. 08-224923 JP 2002-237863A JP 2007-034540 A JP 2005-061269 A

  However, as described above, in the control that starts driving the transport roller after a predetermined time has elapsed since the sensor state change from the paper non-detection state to the paper detection state is recognized, the sensor state change occurs when a communication abnormality occurs. If this occurs, the status change will be recognized when re-communication is successful. That is, the timing start point of the predetermined time is delayed from the time when the state change can be recognized if there is no communication abnormality to the time when the state change can be recognized in the re-communication. In this case, the driving start of the transport roller is also delayed. With the techniques disclosed in the above-mentioned Patent Documents 1 to 7, it is impossible to avoid such a delay in the driving start of the conveying roller.

  The present invention has been made in view of such a problem of the prior art, and provides an image forming apparatus capable of reducing an operation delay due to a communication abnormality without increasing a communication data amount. With the goal.

  In order to achieve the above object, the present invention employs the following technical means. First, an image forming apparatus according to the present invention includes a main device and an accessory device connected to the main device, and specifies in advance between the main device and the accessory device in a state where the accessory device is mounted on the main device. It is premised on an image forming apparatus that performs communication at a sampling cycle. In addition, the image forming apparatus performs the specific drive operation of the other device of the main device and the accessory device at a timing specified in advance based on the state change of one of the main device and the accessory device. It is assumed.

In the image forming apparatus according to the present invention, the one device includes a first free-run counter, a sensor, a counter value holding unit, a data generation unit, a transmission unit, and an abnormality notification reception unit. The sensor detects the above-described state change. The counter value holding unit holds the count value of the first free-run counter when the state change occurs when the state change indicating the state change occurs in the detection state of the sensor. In the communication described above, the data generation unit generates serial data having a predetermined length including information indicating the detection state of the sensor, which is notified to the other device, and other information regarding the one device. Further, when the serial data is not normally received by the other device, the data generation unit includes information indicating the detection state of the sensor corresponding to the subsequent communication timing, and the counter value held in the counter value holding unit. Generate serial data of default length including The transmission unit transmits the serial data generated by the data generation unit to the other device. Then, when the serial data is not normally received by the other device, the abnormality notification receiving unit receives a notification that the communication is abnormal from the other device.

  The other device includes a second free-run counter, a reception unit, a communication abnormality detection unit, a communication abnormality notification unit, a timing start point identification unit, and an operation control unit. The second free run counter outputs a count value associated with the count value of the first free run counter. The receiving unit receives serial data generated in the one device. The communication abnormality detection unit determines whether the serial data has been normally received by the reception unit. When the communication abnormality detection unit determines that the serial data has not been normally received at the reception unit, the communication abnormality notification unit notifies the one device. When the serial data received by the receiving unit does not include a counter value, the timing start point specifying unit specifies a timing start point corresponding to a change in the sensor state based on information indicating the detection state of the sensor included in the serial data. . In addition, when the counter value is included in the serial data received by the receiving unit, the timing start point specifying unit includes information indicating the detection state of the sensor included in the serial data, the counter value, the first free-run counter, and the second Based on the correspondence relationship of the free-run counters, the timing start point corresponding to the sensor state change is specified. Then, the operation control unit causes the specific drive operation to be executed when a predesignated time has elapsed from the timing start point specified by the timing start point specifying unit.

  For example, the other device is an image forming apparatus main body including an image forming unit that forms an image on a recording medium, and the one device is a paper feeding device that supplies the recording medium to the image forming apparatus main body. Can be adopted. In this case, the sensor is a sensor that detects that the recording medium has been normally fed, and a specific driving operation by the operation control unit is carried to the recording medium supplied from the paper feeding device to the image forming unit. The conveyance roller can be driven. Further, the one device is an image forming apparatus main body including an image forming unit that forms an image on a recording medium, and the other device is supplied with a recording medium on which an image is formed in the image forming apparatus main body. A configuration that is a post-processing device can also be adopted. In this case, the sensor is a sensor that detects that the recording medium is normally carried out from the image forming apparatus main body, and a specific driving operation by the operation control unit is applied to the recording medium carried out from the image forming apparatus main body. On the other hand, it is possible to drive a transport roller that transports the post-process to a post-processing execution unit that performs post-processing.

  In this image forming apparatus, when communication is normally performed, the data generation unit includes information indicating a detection state of a sensor that detects a state change that is a reference of timing of a specific driving operation, and the data generation unit. Generate serial data of a predetermined length including other information related to the equipment provided. For example, when the data generation unit is provided in a paper feeder as an accessory device, the paper size, paper orientation, paper remaining amount, paper cassette open / closed state, and the like can be adopted as the other information. On the other hand, when a communication abnormality occurs, the data generation unit calculates the information indicating the detection state of the sensor corresponding to the subsequent communication timing and the first free run counter when the state change occurs in the detection state of the sensor. Generate serial data of default length including numeric values. In this configuration, when a communication abnormality occurs, whether or not a state change has occurred in the detection state of the sensor at the communication timing that was not received due to the communication abnormality, and at what timing if a state change has occurred Information that can confirm whether or not the fluctuation has occurred is included in the serial data of the predetermined length. Therefore, after that, when normal communication can be performed, it is possible to specify at which timing during the communication abnormality the state change has occurred. Therefore, the reference point for the timing for executing the specific drive operation can be traced back when a communication abnormality occurs. As a result, it is possible to reduce the operation delay due to the communication abnormality without increasing the data communication data.

  According to the present invention, it is possible to reduce an operation delay due to a communication abnormality without increasing a communication data amount.

1 is a schematic configuration diagram showing the overall configuration of a multifunction machine according to an embodiment of the present invention. The figure which shows the hardware constitutions of the multifunctional device in one Embodiment of this invention. 1 is a functional block diagram showing a multifunction machine according to an embodiment of the present invention. 1 is a diagram illustrating an example of a configuration of serial data generated by a multifunction machine according to an embodiment of the present invention. The flowchart which shows an example of the communication procedure which the multifunctional machine in one Embodiment of this invention implements The figure which shows the principle of the communication which the multifunctional machine in one Embodiment of this invention implements

  Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. Hereinafter, the present invention is embodied as a digital multi-function peripheral in which a paper feed unit as an accessory device is mounted on a main body of a multi-function peripheral as a main device.

  FIG. 1 is a schematic configuration diagram illustrating an example of the overall configuration of a digital multifunction peripheral according to the present embodiment. As shown in FIG. 1, in the present embodiment, the multi-function device 100 includes a multi-function device main body 101 including an image reading unit 120 and an image forming unit 140, and a platen cover 102 attached above the multi-function device main body 101. . A document table 103 made of a transparent plate such as contact glass is provided on the upper surface of the multifunction machine main body 101, and the document table 103 is opened and closed by a platen cover 102. Further, the platen cover 102 includes a document conveying device 110. An operation panel 171 is provided on the front surface of the multi-function device 100 so that the user can give a copy start or other instruction to the multi-function device 100, and can check the status and settings of the multi-function device 100.

  An image reading unit 120 is provided below the document table 103. The image reading unit 120 reads an image of a document with the scanning optical system 121 and generates digital data (image data) of the image. The document can be placed on the document table 103 or the document transport device 110. The scanning optical system 121 includes a first carriage 122, a second carriage 123, and a condenser lens 124. The first carriage 122 is provided with a linear light source 131 and a mirror 132, and the second carriage 123 is provided with mirrors 133 and 134. The light source 131 illuminates the document. The mirrors 132, 133, and 134 guide reflected light from the document to the condenser lens 124, and the condenser lens 124 forms an optical image on the light receiving surface of the line image sensor 125. In the scanning optical system 121, the first carriage 122 and the second carriage 123 are provided so as to reciprocate in the sub-scanning direction 135. By moving the first carriage 122 and the second carriage 123 in the sub-scanning direction 135, the image of the document placed on the document table 103 can be read by the image sensor 125. When reading an image of a document set on the document conveying device 110, the image reading unit 120 temporarily fixes the first carriage 122 and the second carriage 123 according to the image reading position, and passes the image reading position. Are read by the image sensor 125. The image sensor 125 generates document image data from the light image incident on the light receiving surface. The generated image data can be printed on paper (recorded material) in the image forming unit 140. The generated image data can also be transmitted to other devices through a network via a network interface (not shown) or the like.

  The image forming unit 140 prints image data obtained by the image reading unit 120 or image data received from another device through the network on a sheet. The image forming unit 140 includes a photosensitive drum 141. The photosensitive drum 141 rotates in one direction at a constant speed. Around the photosensitive drum 141, a charger 142, an exposure unit 143, a developing unit 144, and a cleaning unit 145 are arranged in this order from the upstream side in the rotation direction. The charger 142 uniformly charges the surface of the photosensitive drum 141. The exposure device 143 irradiates the surface of the uniformly charged photoconductor drum 141 with light according to the image data, and forms an electrostatic latent image on the photoconductor drum 141. The developing device 144 attaches toner to the electrostatic latent image and forms a toner image on the photosensitive drum 141. The cleaning unit 145 cleans the surface of the photosensitive drum 141 by removing waste toner remaining on the surface of the photosensitive drum 141 after the transfer from the photosensitive drum 141. These processes are performed in series by the rotation of the photosensitive drum 141.

  The image forming unit 140 feeds paper from the paper feed tray 161 to the transfer unit between the photosensitive drum 141 and the transfer roller 146. Various sizes of paper can be placed on the paper feed tray 161. The image forming unit 140 feeds the paper placed on the paper feed tray 161 by the feed roller 162. The fed paper is conveyed to the transfer unit by the registration roller 163 at a predetermined timing. The sheet on which the toner image is transferred is conveyed to the fixing device 148 by the conveyance belt 147. The fixing device 148 has a fixing roller 151 and a pressure roller 152 with a built-in heater, and fixes the toner image on the sheet by heat and pressing force. The image forming unit 140 discharges the sheet that has passed through the fixing device 148 to the discharge tray 149.

  In addition, the multi-function device 100 is configured so that a paper feed unit 180 can be attached to the bottom of the multi-function device main body 101 as needed. That is, the multi-function device 100 includes a paper carry-in port 165 into which paper is carried from the paper feed unit 180 on the bottom surface of the multi-function device main body 101, and a carry roller that carries the paper carried through the paper carry-in port 165 to the registration roller 163. 164.

  The paper supply unit 180 includes a paper supply cassette 181 that stores paper, and sends out the paper stored in the paper supply cassette 181 to the outside of the paper supply unit 180 through the paper carry-out port 184. When the paper feed unit 180 is mounted on the multifunction peripheral 100, the paper carry-out port 184 and the paper carry-in port 165 are positioned to face each other. In this example, the paper feed unit 180 includes one paper feed cassette 181, but may include a plurality of paper feed cassettes.

  The paper feed cassette 181 can store paper of various sizes. When the user designates paper feeding from the paper feed cassette 181, the multifunction peripheral 100 feeds the paper in the paper feed cassette 181 by the feed roller 182. The fed paper is conveyed to the conveyance roller 164 through the paper carry-out port 184 and the paper carry-in port 165. The conveyance roller 164 conveys the sheet to the registration roller 163.

  In the present embodiment, the paper feed unit 180 includes a paper feed sensor 183 in a paper transport path (hereinafter referred to as a paper feed detection position) between the feed roller 182 and the paper carry-out port 184. The paper feed sensor 183 has a function of detecting whether or not the paper fed by the feed roller 182 has reached the feed paper detection position. Although any sensor that realizes the function can be used as the paper feed sensor 183, here, a transmissive optical sensor (photo interrupter) arranged in a state in which the paper passes between the light emitting unit and the light receiving unit. ) Is used as the paper feed sensor 183.

  The multi-function device 100 acquires the detection state of the paper feed sensor 183 at a predetermined sampling cycle, and a predetermined time has elapsed since the paper feed sensor 183 changed from the paper non-detection state to the paper detection state in the sampling cycle. After that (for example, after several tens of milliseconds), the conveyance roller 164 is driven to rotate. That is, the conveyance roller 164 is driven only when a sheet is carried in through the sheet carry-in entrance 165. Note that the paper feed unit 180 and the MFP main body 101 are connected via an interface 190 so that data can be exchanged.

  FIG. 2 is a hardware configuration diagram of a control system in the multifunction machine. The MFP main body 101 according to the present embodiment includes a CPU (Central Processing Unit) 201, a RAM (Random Access Memory) 202, a ROM (Read Only Memory) 203, an HDD (Hard Disk Drive) 204, an original transport device 110, and an image reading unit. 120, a driver 205 corresponding to each drive unit in the image forming unit 140 is connected via an internal bus 206. The ROM 203, the HDD 204, and the like store programs, and the CPU 201 controls the multifunction peripheral 100 in accordance with instructions from the control program. For example, the CPU 201 uses the RAM 202 as a work area, and controls the operation of each driving unit by exchanging data and commands with the driver 205. The HDD 204 is also used to store image data obtained by the image reading unit 120 and image data received from other devices via a network.

  An operation panel 171 and various sensors 207 are also connected to the internal bus 206. The operation panel 171 receives a user operation and supplies a signal based on the operation to the CPU 201. Further, the operation panel 171 displays an operation screen on a display provided in the operation panel 171 according to a control signal from the CPU 201. The sensor 207 includes various sensors such as an open / close detection sensor for the platen cover 102, a document detection sensor on the document table 103, a temperature sensor for the fixing device 148, and a detection sensor for the conveyed paper or document. The CPU 201 implements the following means (functional blocks) by executing a program stored in the ROM 203, for example.

  Similarly, in the sheet feeding unit 180 of this embodiment, a CPU 211, a RAM 212, a ROM 213, and a driver 215 corresponding to each drive unit in the sheet feeding unit 180 are connected via an internal bus 216. The ROM 213 and the like store a program, and the CPU 211 controls the sheet feeding device 180 in accordance with a command of the control program and a command of the CPU 201 of the multifunction machine main body 101. For example, the CPU 211 uses the RAM 212 as a work area, and controls the operation of each drive unit by exchanging data and commands with the driver 215. A sensor 217 including a paper feed sensor 183 and a paper remaining amount sensor is also connected to the internal bus 216. The CPU 211 implements the following means (functional blocks) by executing a program stored in the ROM 213, for example. The internal bus 206 and the internal bus 216 are connected via an interface 190 in a state where data can be exchanged.

  FIG. 3 is a functional block diagram of the MFP according to the present embodiment. As described above, in the MFP 100 of the present embodiment, the MFP main body 101 and the paper feeding unit 180 as an accessory device are connected via the interface 190 so as to be able to exchange data. As shown in FIG. 3, the paper supply unit 180 as an accessory device includes a data generation unit 301, a transmission unit 302, an abnormality notification reception unit 303, a free-run counter 304 (first free-run counter), and a counter value holding unit 305. Is provided.

  As is well known, the free-run counter 304 is a counter that keeps incrementing a count value in response to a signal input. For example, in the case of an 8-bit configuration, it is incremented one by one from 0 and returns to 0 after reaching 255. In the present embodiment, the input signal to the free-run counter 304 is a periodic signal defined based on a clock signal generated by a clock signal generator (not shown) included in the multi-function peripheral body 101. The clock signal generated by the clock signal generator is also used for defining the above-described sampling period. In this embodiment, the input cycle of the input signal of the free-run counter 304 is set to be shorter (for example, 1/5) than the above-described sampling cycle. Further, here, the free-run counter 304 is configured to start when power is supplied to the paper feeding unit 180 and to have a count value of 0 when started.

  The counter value holding unit 305 holds the count value of the free-run counter 304 when the state change occurs when the state change occurs in the detection state of the notification target sensor (here, the paper feed sensor 183). . Here, the counter value holding unit 305 constantly monitors the output of the paper feed sensor 183, and acquires the count value from the free-run counter 304 when the paper feed sensor 183 changes from the paper non-detection state to the paper detection state. And hold on to yourself. Although not particularly limited, in this embodiment, when the paper feed sensor 183 changes from the paper detection state to the paper detection state, the counter value holding unit 305 sets a specific value (here, the maximum value 127 of the free-run counter 304). ).

  The data generation unit 301 generates serial data having a predetermined length to be transmitted to the multi-function peripheral body 101 in accordance with the communication timing of the sampling cycle described above. In addition, the data generation unit 301 generates different serial data depending on whether the serial data generated earlier is normally received by the MFP main body 101 or not. In the former case, the serial data includes information indicating the detection state of the sensor to be notified (here, the paper feed sensor 183) and other information related to the paper feed unit 180. In the latter case, the serial data includes information indicating the detection state of the notification target sensor corresponding to the communication timing after the communication timing that has not been normally received, and the counter value held in the counter value holding unit 305. . Although not particularly limited here, the data generation unit 301 generates 8-bit serial data used for general serial data communication. The configuration of the serial data will be described later. In this embodiment, as will be described later, as other information related to the paper feed unit 180, the output value of the paper remaining amount sensor 321 provided in the paper feed unit 180 is used.

  The transmission unit 302 transmits the serial data generated by the data generation unit 301 to the MFP main body 101. The communication is performed via the interface 190, and the transmitted serial data is received by the receiving unit 311 of the multifunction machine main body 101 as described later.

  The abnormality notification receiving unit 303 receives a notification from the multifunction device main body 101 that there is a communication abnormality when serial data is not normally received by the multifunction device main body 101. The communication is also performed through the interface 190. Note that, as will be described later, the notification is transmitted from the communication abnormality notification unit 313 of the MFP main body 101.

  Further, the MFP main body 101 includes a receiving unit 311, a communication abnormality detecting unit 312, a communication abnormality notifying unit 313, a timing start point specifying unit 314, an operation control unit 315, a correspondence relationship holding unit 316, and a free run counter 317 (second free run counter 317). Run counter).

  Similar to the above-described free-run counter 304, the free-run counter 317 is a counter that continuously increments the count value in response to a signal input. However, the free run counter 317 is configured to output a count value associated with the count value of the free run counter 304. Here, “corresponding” means that at least the count value of the free-run counter 317 corresponding to the count value can be specified from the count value of the free-run counter 304. Here, the free-run counter 317 is configured by a counter having the same number of bits (here, 6 bits) as the free-run counter 304 to which a signal having the same cycle as the input signal to the free-run counter 304 is input. Further, here, the free-run counter 317 is configured to be activated when power is supplied to the multi-function peripheral body 101, and the count value is set to 0 when activated.

  The correspondence relationship holding unit 316 holds the correspondence relationship between the free run counter 304 and the free run counter 317. Here, the correspondence relationship means information for specifying the count value of the free-run counter 317 corresponding to the count value from the count value of the free-run counter 304. As described above, in this embodiment, the number of bits of the free-run counter 304 and the free-run counter 317 are the same, and the period of the input signal is also the same. Therefore, if the difference between the count value of the free run counter 304 and the count value of the free run counter 317 at a certain point in time is acquired, the count value of the free run counter 304 can be calculated using the difference value. The count value of the corresponding free-run counter 317 can be derived. Here, the correspondence holding unit 316 acquires the count values of the free-run counter 304 and the free-run counter 317 after a predetermined time has elapsed since the power was turned on to the MFP main body 101 and the paper feed unit 180, and holds the difference therebetween. It is configured to do.

  The reception unit 311 receives the serial data generated by the data generation unit 301 of the paper feed unit 180 and transmitted by the transmission unit 302. As described above, the communication is performed via the interface 190.

  The communication abnormality detection unit 312 determines whether the serial data has been normally received by the reception unit 311. Although not particularly limited, in this embodiment, a parity bit is provided in the serial data, and the communication abnormality detection unit 312 determines the presence or absence of a communication abnormality by a parity check using the parity bit. It should be noted that any known method can be employed as a method for detecting a communication abnormality. For example, the communication abnormality detection unit 312 may simply determine whether the data has been normally received based on the presence or absence of data that has reached the reception unit 311.

  When the communication abnormality detection unit 312 determines that the serial data has not been normally received by the reception unit 311, the communication abnormality notification unit 313 notifies the paper feeding unit 180 to that effect. As described above, the communication is performed via the interface 190, and the notification is received by the abnormality notification receiving unit 303 of the sheet feeding unit 180 as described above.

  When the serial data received by the receiving unit 311 does not include a counter value, the timing start point specifying unit 314 is based on information indicating the detection state of the notification target sensor (here, the paper feed sensor 183) included in the serial data. Thus, the timing start point corresponding to the state change of the sensor is specified. In addition, when the serial data received by the receiving unit 311 includes a counter value, the timing start point specifying unit 314 includes information indicating the detection state of the notification target sensor (here, the paper feed sensor 183) included in the serial data, Based on the counter value and the corresponding relationship between the free-run counter 304 and the free-run counter 317, the timing start point corresponding to the sensor state change is specified. As described above, whether or not the counter value is included in the serial data depends on whether or not the previous serial data is normally received by the multi-function peripheral body 101. Therefore, the time measurement start point specifying unit 314 specifies the time measurement start point after recognizing which configuration the serial data received by the reception unit 311 is based on the determination result of the communication abnormality detection unit 312. The correspondence relationship held in the correspondence relationship holding unit 316 is used as the correspondence relationship between the free run counter 304 and the free run counter 317.

  The operation control unit 315 is a drive unit (here, a conveyance roller) to be driven when a specific drive operation is performed after a predetermined time has elapsed from the change in the state of the sensor recognized by the timing start point specifying unit 314. 164) is driven.

  Here, the configuration of serial data generated by the data generation unit 301 will be described. 4A and 4B are diagrams illustrating an example of the configuration of serial data generated by the data generation unit 301. FIG. 4A corresponds to the serial data generated by the data generation unit 301 when the generated serial data is normally received by the MFP main body 101, and FIG. This corresponds to serial data generated by the data generation unit 301 when it is not normally received.

  When normal communication is performed, serial data generated by the data generation unit 301 (hereinafter referred to as normal serial data as appropriate) includes information indicating the detection state of the paper feed sensor 183 and the paper feed unit 180. And other information about. Here, the information indicating the detection state of the paper feed sensor 183 is 1-bit data indicating either the paper non-detection state or the paper detection state. Although not particularly limited, here, the paper non-detection state is “0”, and the paper detection state is “1”. The other information is information that is essential for the MFP main body 101 to acquire information but is not essential to be acquired at all the communication timings of the sampling period. Such information is, for example, information that varies depending on the user's work and the like, and includes opening / closing of the paper feed cassette, paper size, and paper orientation. Further, when the remaining amount of paper also increases, it is a variation according to the user's work, and thus is included in the other information. The serial data preferably includes a plurality of these pieces of information as other information, but here, for the sake of explanation, the data generation unit 301 uses only the output value of the paper remaining amount sensor 321 as the other information. Is included.

  In this example, the remaining paper amount sensor 321 converts an analog value indicating the height of the bottom plate disposed at the bottom of the paper feed cassette 181 into a 6-bit (64 divisions) digital value and outputs it. The bottom plate is configured to rise as the remaining amount of sheets stacked on the bottom plate decreases, and the amount of increase is detected by the remaining amount sensor 321. The amount of increase is divided into 64 levels from full paper (minimum increase) to no paper (maximum increase).

  The data generation unit 301 generates 8-bit normal serial data from 1-bit information indicating the detection state of the paper feed sensor 183, 6-bit information indicating the remaining amount of paper, and 1 parity bit. Although not particularly limited, in this embodiment, as shown in FIG. 4A, the most significant bit 401 of the serial data is a parity bit (in this case, an odd parity method), and the least significant bit 403 of the serial data is The information indicates the detection state of the paper feed sensor 183. The intermediate bit 402 is information indicating the remaining amount of paper.

  FIG. 4A shows serial data generated during the n-th communication, the (n + 1) -th communication, and the (n + 2) -th communication corresponding to the above-described sampling period. Here, it is assumed that the serial data is normally received by the MFP main body 101 even in the (n-1) th communication.

In the n-th communication, the data generation unit 301 generates the normal serial data described above because there is no abnormality in the previous communication. That is, the data A _n indicating detection status of the paper feed sensor 183 corresponding to the communication timing is arranged on the least significant bit 403, the data B _n indicating the remaining sheets corresponding to the communication timing to the intermediate bit 402 is arranged The Then, the parity bit P _n corresponding to these data is arranged in the most significant bit 401.

When the n-th communication is normally completed, the data generation unit 301 generates normal-time serial data during the (n + 1) -th communication. That is, data A _{n + 1} indicating the detection state of the paper feed sensor 183 corresponding to the communication timing is arranged in the least significant bit 403, and data B _{n + 1} indicating the remaining amount of paper corresponding to the communication timing is arranged in the intermediate bit 402. The Then, the most significant bit 401, the parity bit P _{n + 1} corresponding to these data are placed. Similarly, when the (n + 1) th communication is normally completed, the data generation unit 301 performs data A _{n + 2} indicating the detection state of the paper feed sensor 183 corresponding to the communication timing in the least significant bit 403 during the (n + 2) th communication. Serial data is generated with data B _{n + 2} indicating the remaining amount of paper corresponding to the communication timing in the intermediate bit 402 and parity bits P _{n + 2} corresponding to these data in the most significant bit 401.

  On the other hand, when the serial data is not normally received by the MFP main body 101, the serial data generated by the data generation unit 301 (hereinafter referred to as abnormal serial data as appropriate) is supplied corresponding to the subsequent communication timing. Information indicating the detection state of the paper sensor 183 and the counter value held in the counter value holding unit 305 are included. That is, the data generation unit 301 includes 1-bit information indicating the detection state of the paper feed sensor 183 corresponding to the communication timing, and the counter value held in the counter value holding unit 305, similar to the normal serial data. 8-bit abnormal serial data is generated from the bit information and one parity bit. Although not particularly limited, in this embodiment, as shown in FIG. 4B, the most significant bit 401 of the serial data is a parity bit (in this case, an odd parity method), and the least significant bit 403 of the serial data is The information indicates the detection state of the paper feed sensor 183. The intermediate bit 402 is information including the counter value held in the counter value holding unit 305.

  FIG. 4B shows serial data generated during the n-th communication, the (n + 1) th communication, the (n + 2) th communication, and the (n + 3) th communication corresponding to the above-described sampling period. Here, it is assumed that the serial data is normally received by the MFP main body 101 in the (n-1) th communication.

In the n-th communication, the data generation unit 301 generates the normal serial data described above because there is no abnormality in the previous communication. That is, the data A _n indicating detection status of the paper feed sensor 183 corresponding to the communication timing is arranged on the least significant bit 403, the data B _n indicating the remaining sheets corresponding to the communication timing to the intermediate bit 402 is arranged The Then, the parity bit P _n corresponding to these data is arranged in the most significant bit 401.

When the MFP main body 101 cannot receive the serial data normally in the n-th communication, the data generation unit 301 generates abnormal serial data in the (n + 1) th communication. In this case, the data A _{n + 1} indicating the detection state of the paper feed sensor 183 corresponding to the communication timing is arranged in the least significant bit 403, and the counter value C _{n + 1} held in the counter value holding unit 305 is arranged in the intermediate bit 402. The Then, the most significant bit 401, the parity bit P _{n + 1} corresponding to these data are placed.

When the MFP main body 101 cannot receive the serial data normally in the (n + 1) th communication, the data generation unit 301 generates the abnormal time serial data again in the (n + 2) th communication. In this case, data _{An + 2} indicating the detection state of the paper feed sensor 183 corresponding to the communication timing is arranged in the least significant bit 403, and the counter value Cn _{+ 2} held in the counter value holding unit 305 is arranged in the intermediate bit 402. The In the most significant bit 401, parity bits P _{n + 2} corresponding to these data are arranged.

When the n + 2th communication is normally completed, the data generation unit 301 generates the normal serial data. That is, data A _{n + 3} indicating the detection state of the paper feed sensor 183 corresponding to the communication timing is arranged in the least significant bit 403, and data B _{n + 3} indicating the remaining amount of paper corresponding to the communication timing is arranged in the intermediate bit 402. The Then, the parity bit P _{n + 3} corresponding to these data is arranged in the most significant bit 401.

Here, between the nth communication and the (n + 1) th communication, the paper feed sensor 183 changes from the paper non-detection state to the paper detection state, and after the n + 3th communication, the paper feed sensor 183 changes from the paper detection state to the paper. Assume that the state has changed to a non-detection state. In this case, the counter value holding unit 305 holds a specific value (127 in this case) at the n-th communication point, and the state of the free-run counter 304 at the time of state change at the n + 1-th, n + 2-th, and n + 3-th communication points. The count value is held. In this case, both C _{n + 1} and C _{n + 2} become count values of the free-run counter 304 at the time of state change. In this case, A _n = 0, A _{n + 1} = 1, A _{n + 2} = 1, and A _{n + 3} = 1.

Further, the paper feed sensor 183 changes from the paper non-detection state to the paper detection state between the (n + 1) th communication and the (n + 2) th communication, and the paper feed sensor 183 changes from the paper detection state to the paper non-detection after the n + 3th communication. Assume that the state has changed to the detection state. In this case, the counter value holding unit 305 holds a specific value (127 in this case) at the n-th and n + 1-th communication points, and the free-run counter 304 at the time of state change at the n + 2-th and n + 3-th communication points. The count value is held. In this case, C _{n + 1} is a specific value, and C _{n + 2} is a count value of the free-run counter 304 at the time of state change. In this case, A _n = 0, A _{n + 1} = 0, A _{n + 2} = 1, and A _{n + 3} = 1.

  By using the data configuration as described above, when a communication abnormality occurs, information on the time when the state change has occurred in the subsequent communication can be acquired on the MFP main body 101 side. In addition, as described above, the multifunction machine main unit 101 (timekeeping start point specifying unit 314) calculates the count value of the corresponding free-run counter 317 from the counter value acquired from the serial data (the count value of the free-run counter 304). Can be acquired. The signal cycle of the input signal to the free-run counter 317 is also fixed. Therefore, for example, a communication error occurs by comparing the count value of the free-run counter 317 at the time of acquiring the serial data with the count value of the free-run counter 317 corresponding to the counter value acquired from the serial data. It is possible to recognize at which communication timing the detection state of the paper feed sensor 183 has changed.

  In the case of abnormal serial data, information notified by the intermediate bit 402 of the normal serial data is lost. However, as described above, it is indispensable that the information arranged in the intermediate bit 402 is acquired in all the communication timings, although it is indispensable to acquire the information in the multifunction machine main body 101. Therefore, even if it is missing, there is no problem in the operation of the multifunction device 100. Temporary communication abnormalities (communication failures) due to noise superimposition, etc., will not be interrupted for a long period of time when the data is missing, and will be recovered in several communication cycles. It is possible to operate normally by acquiring the data.

  Next, communication processing executed by the multifunction machine 100 will be described. FIG. 5 is a flowchart illustrating an example of a communication procedure performed by the multifunction peripheral 100. As described above, the multifunction peripheral 100 acquires the detection state of the paper feed sensor 183 of the paper feed unit 180 by communication at a predetermined sampling cycle, and the paper feed sensor 183 detects the paper detection from the paper non-detection state in the sampling cycle. The conveyance roller 164 is driven to rotate after a predetermined time has elapsed (in this case, after Z milliseconds) from when the state is changed. As described above, the sampling period (communication period) is defined based on a clock signal generated by a clock signal generator (not shown). The communication cycle can be set to several milliseconds, for example. The procedure is started, for example, as a trigger when an image forming instruction using the paper feed unit 180 is input in the multifunction peripheral 100.

  When the procedure starts, the data generation unit 301 of the paper feeding unit 180 waits until the communication timing comes (step S501 Yes, S502 No). When the communication timing arrives, the data generation unit 301 generates serial data based on the outputs of the paper feed sensor 183 and the remaining paper amount sensor 321 (steps S502 Yes, S503). At the first communication timing at which the procedure starts, there is no communication with the previous MFP main body 101, and therefore the previous communication cannot be determined to be abnormal. Therefore, the data generation unit 301 generates the above-described normal serial data. The data generation unit 301 that has generated the serial data transmits the serial data generated through the transmission unit 302 to the MFP main body 101 (step S504). The serial data transmitted through the transmission unit 302 is received by the reception unit 311 of the multifunction machine main body 101.

  When the communication is completed, the communication abnormality detection unit 312 of the MFP main body 101 determines whether or not the communication has been normally performed (step S505). As described above, in the present embodiment, the determination is performed using the parity bit included in the serial data. When the communication is normal, the communication abnormality detection unit 312 notifies the timing start point specifying unit 314 to that effect. As described above, when the communication abnormality detection unit 312 determines that communication has been normally performed, the abnormality notification reception unit 303 of the paper feeding unit 180 does not receive a notification from the multifunction peripheral body 101 that a communication abnormality has occurred. In this case, the data generation unit 301 generates normal serial data at the next incoming communication timing (steps S505 Yes, S501 Yes, S502 Yes, S503). Further, by the notification from the communication abnormality detection unit 312, the timing start point specifying unit 314 can recognize that the serial data received by the receiving unit 311 next is serial data at normal time.

  On the other hand, when there is an abnormality in communication, the communication abnormality detection unit 312 notifies the time measurement start point specifying unit 314 and the communication abnormality notification unit 313 to that effect (No in step S505). The communication abnormality notifying unit 313 that has received the notification notifies the abnormality notification receiving unit 303 of the paper feeding unit 180 that the communication has been abnormal first (that serial data has not been normally received). The abnormality notification receiving unit 303 that has received the notification notifies the data generation unit 301 to that effect. In this case, the data generation unit 301 generates the above-described abnormal serial data at the next incoming communication timing (steps S506 Yes, S507 Yes, S508). Further, by the notification from the communication abnormality detection unit 312, the time measurement starting point identification unit 314 can recognize that the serial data received by the reception unit 311 next is serial data at the time of abnormality.

  The data generation unit 301 that has generated the serial data at the time of abnormality transmits the serial data at the time of abnormality to the MFP main body 101 through the transmission unit 302 (step S509). The serial data transmitted through the transmission unit 302 is received by the reception unit 311 of the multifunction machine main body 101. Also for the communication, the communication abnormality detection unit 312 of the MFP main body 101 determines whether the communication has been normally performed (step S505).

  In the above-described procedure, when the sheet feeding unit 180 feeds the MFP main body 101 and there is no need to continue feeding thereafter, the procedure ends (No in steps S501 and S506). .

  Here, the operation of the timing start point specifying unit 314 will be described. As described above, the timing start point specifying unit 314 recognizes whether the serial data received by the receiving unit 311 next is normal data or abnormal serial data based on the notification from the communication abnormality detection unit 312. can do.

  For normal serial data, the timing start point specifying unit 314 reads and holds the least significant bit of the serial data. Then, it is compared with the least significant bit of the serial data received immediately before that is held by itself, and if both values are different, it is determined that a state change has occurred, and the communication timing is specified as the timing start point. In this embodiment, if the least significant bit of serial data received immediately before is “0” (paper non-detection state) and the least significant bit of serial data recently received is “1” (paper detection state), The timing start point identifying unit 314 recognizes that a state change has occurred. Note that when normal serial data is received, the serial data received immediately before is also received normally.

  For abnormal serial data, the timing start point specifying unit 314 reads and holds the least significant bit of the serial data as in the normal serial data. Then, it is compared with the least significant bit of the serial data received immediately before held in itself. If both are the same value, the time-measurement start point specifying unit 314 determines that no state change has occurred, and does not perform any other processing. On the other hand, if the values are different from each other, the timing start point specifying unit 314 reads the intermediate bit (the count value of the free-run counter 304) of the serial data. Then, the count value of the corresponding free-run counter 317 is derived from the intermediate bit data based on the correspondence held in the correspondence holding unit 316. The timing start point specifying unit 314 measures the communication timing (first communication timing after the occurrence of the state change of the paper feed sensor 183) from among the communication timings at which the communication abnormality has occurred based on the derived count value. Specify as the starting point. Such identification can be easily performed based on, for example, the derived count value, the signal period of the input signal to the free-run counter 317, and the count value of the free-run counter 317 at that time.

  As described above, the timing start point specifying unit 314 that specified the timing start point notifies the operation control unit 315 of the specified communication timing. Receiving the notification, the operation control unit 315 drives the transport roller 164 when a pre-designated Z millisecond has elapsed from the notified communication timing.

  FIG. 6A to FIG. 6C are diagrams illustrating the effects of the communication procedure described above. 6A corresponds to a state in which normal communication is continuously performed, and FIGS. 6B and 6C illustrate a case where communication abnormality continues when the state of the paper feed sensor 183 changes. Corresponds to the state that occurred. FIG. 6B corresponds to the operation of this embodiment, and FIG. 6C corresponds to the conventional retry operation. 6A to 6C, the detection state of the paper feed sensor 183, the communication timing (communication interval) between the MFP main body 101 and the paper feed unit 180, and the paper feed sensor recognized by the MFP main body 101. A detection state 183 (main body recognition state change) and a driving state of the conveying roller 164 are shown. In FIG. 6A to FIG. 6C, the horizontal axis corresponds to time. In the detection state of the paper feed sensor 183, the Low level corresponds to the paper non-detection state, and the High level corresponds to the paper detection state. The communication interval indicates that communication is performed at the timing when a pulse is generated. In the main body recognition state change, the Low level corresponds to the paper non-detection state, and the High level corresponds to the paper detection state. In the conveyance roller driving state, the Low level corresponds to stop and the High level corresponds to driving.

  In this example, the paper feed sensor 183 of the paper feed unit 180 changes from the paper non-detection state to the paper detection state immediately before the timing pulse P (T milliseconds). In this case, when normal communication is continuously performed, as shown in FIG. 6A, in the communication at the timing pulse P, the timing start point identifying unit 314 recognizes that a state change has occurred, The communication control unit 315 is notified of the communication timing. As a result, the transport roller 164 starts to be driven by the operation control unit 315 when a predetermined Z millisecond has elapsed from the timing pulse P.

  On the other hand, when an abnormality occurs in the communication at the timing pulse P after the timing pulse P and the timing pulse P, and the communication at the timing pulse R after the timing pulse Q is normal, the MFP 100 according to the present embodiment can be used. Then, as described above, based on the serial data in the communication of the timing pulse R, the timing start point specifying unit 314 can specify the communication timing of the timing pulse P as the timing start point, and the communication timing is determined as the operation control unit 315. Notify As a result, as shown in FIG. 6B, the transport roller 164 is started to be driven by the operation control unit 315 when a predetermined Z millisecond has elapsed from the timing pulse P. That is, there is no difference in the drive start timing of the transport roller 164 between when a communication error occurs and when no communication error occurs.

  On the other hand, in the conventional method of simply repeating communication retries, an abnormality occurs in communication at timing pulse P and timing pulse Q, and normal communication can be performed in communication at timing pulse R. The machine body 101 recognizes that a state change has occurred due to serial data in the communication of the timing pulse R. Therefore, as shown in FIG. 6C, the conveyance roller 164 starts to be driven when a predetermined Z millisecond elapses from the timing pulse R. Therefore, when a communication abnormality occurs, the driving start timing of the transport roller 164 is delayed compared to a case where no communication abnormality occurs.

  Even in the MFP 100 according to the present embodiment, if the product of the communication interval and the number of consecutive occurrences of communication abnormality is greater than Z milliseconds, the conveyance is performed at the same drive start timing as when no communication abnormality has occurred. The roller 164 cannot be driven. However, since the time starting point of Z milliseconds can be traced back, the delay of the drive start timing can be reduced as compared with the conventional method. In addition, when normal communication is possible after the occurrence of a communication error and Z milliseconds have already elapsed from the communication timing at which the state change occurred (when the time measurement start point is before Z milliseconds), Z milliseconds Therefore, the operation control unit 315 may drive the transport roller 164 immediately.

  In the above embodiment, the counts of the free-run counter 304 and the free-run counter 317 and the cycle of the input signal are the same. However, from the count value of the free-run counter 304, the free-run counter 317 corresponding to the count value If it is possible to specify the count values, it is not essential that they are the same, but they are arbitrary. For example, as long as the condition is satisfied, the count number of the free-run counter 304 and the count number of the free-run counter 317 may be in a multiplying relationship with respect to the other. Further, in this case, one of the input signal cycle of the free-run counter 304 and the input signal cycle of the free-run counter 317 may have a multiplication relationship with respect to the other. However, it is necessary to satisfy the condition that the input signal period of the free-run counter 304 and the input signal period of the free-run counter 317 are at least shorter than the above-described sampling period.

  As described above, in the multifunction device 100, the data generation unit 301, when the serial data generated earlier is not normally received by the multifunction device main body 101, the communication timing after the communication timing that has not been normally received. And serial data including information indicating the detection state of the paper feed sensor 183 corresponding to, and the count value of the free-run counter 304 when a state change occurs in the detection state of the paper feed sensor 183. That is, when a communication abnormality occurs, whether or not a state change has occurred in the detection state of the paper feed sensor 183 at a communication timing that has not been received due to the communication abnormality, and at what timing if a state change has occurred Since the serial data includes information for confirming whether or not the fluctuation has occurred, it is possible to specify at which timing during the abnormal communication when the normal communication is possible. For this reason, even if communication fails, the reference point for starting driving of the transport roller driven after a predetermined time can be accurately recognized based on the change in the detection state of the paper feed sensor 183, and communication abnormalities can be detected. The resulting operation delay can be reduced.

  Further, since the bit length of the serial data at the time of occurrence of the abnormality is the same as the bit length of the serial data at the time of normal communication, the data communication data is not increased. Further, since the data replaced in the serial data at the time of occurrence of the abnormality is data that is not allowed to be notified to the MFP main body 101 in each communication, the data replacement does not hinder the operation of the MFP. .

  The above-described embodiments do not limit the technical scope of the present invention, and various modifications and applications other than those already described are possible within the scope of the present invention. For example, the configuration of the serial data described in the above embodiment is an example, and the number of bits, the bit arrangement, and the like can be arbitrarily changed.

  Further, in the above embodiment, the paper feed unit is exemplified as the accessory device, and the multifunction device main body performs a specific drive operation at a predetermined timing based on a change in the detection state of the paper feed sensor included in the paper feed unit. The transport roller is driven. However, the present invention can be applied to any configuration in which the MFP main body performs a specific driving operation at a timing specified in advance with reference to a state change of the sensor detection state of the accessory device. The target sensor and the target driving operation are arbitrary.

  Furthermore, in the above embodiment, the detection state of the sensor included in the accessory device is notified to the multifunction device main body. However, the detection state of the sensor included in the multifunction device main body, such as the multifunction device main body and the post-processing device, is attached. It is also possible to apply to a configuration in which a device is notified and an attached device performs a specific driving operation in response to the notification. For example, the sensor included in the MFP main body is a sensor that detects that the MFP main body has been normally carried out normally, and the specific driving operation performs post-processing on the paper carried out from the MFP main body. The present invention can be applied to the case of driving a conveyance roller that conveys to a post-processing execution unit. In this case, the multifunction device main body includes a first free run counter, a sensor that detects a change in state, a counter value holding unit, a data generation unit, a transmission unit, and an abnormality notification reception unit, and the attached device has a second free run counter. A counter, a reception unit, a communication abnormality detection unit, a communication abnormality notification unit, a timing start point identification unit, and an operation control unit may be provided.

  Further, the flowchart shown in FIG. 5 is an example, and the order of the steps and the like can be changed as appropriate within a range in which equivalent actions are achieved. For example, in the flowchart shown in FIG. 5, the data generation unit is configured to generate serial data when the communication timing arrives. However, the serial data may be transmitted corresponding to the communication timing, and the data generation The timing is not limited to the communication timing. For example, even if the data generation unit generates serial data at a predetermined data generation timing after the previous communication is completed and before the next communication timing arrives, the serial data is transmitted when the communication timing arrives. Good.

  In addition, in the above-described embodiment, the present invention is embodied as a digital multifunction peripheral. However, the present invention can be applied not only to a digital multifunction peripheral but also to an arbitrary image forming apparatus such as a printer or a copying machine. .

  According to the present invention, it is possible to reduce an operation delay due to a communication abnormality without increasing the amount of communication data, which is useful as an image forming apparatus.

100 MFP (image forming device)
101 MFP main body (main device: other device)
164 Conveying roller 180 Paper feeding unit (Attached equipment: One equipment)
183 Paper feed sensor 190 Interface 301 Data generation unit 302 Transmission unit 303 Abnormality notification reception unit 304 Free run counter (first free run counter)
305 Counter value holding unit 311 Receiving unit 312 Communication abnormality detecting unit 313 Communication abnormality notifying unit 314 Timing start point specifying unit 315 Operation control unit 316 Correspondence holding unit 317 Free run counter (second free run counter)

Claims (3)

A main device and an accessory device connected to the main device, and the accessory device is connected to the main device, and communicates with the main device and the accessory device at a sampling period specified in advance. And an image forming apparatus in which the other device of the main device and the accessory device performs a specific driving operation at a timing designated in advance with reference to a state change of one of the main device and the accessory device. Because
The one device is
A first free-run counter;
A sensor for detecting the state change;
A counter value holding unit that holds a count value of the first free-run counter when the state change occurs when the state change indicating the state change occurs in the detection state of the sensor;
Generating a predetermined length of serial data including information indicating a detection state of the sensor and other information related to the one device, which is notified to the other device in the communication; Data that generates serial data of a predetermined length including information indicating the detection state of the sensor corresponding to the subsequent communication timing and the counter value held in the counter value holding unit when the device does not receive normally A generator,
A transmission unit for transmitting the serial data generated by the data generation unit to the other device;
When the serial data is not normally received in the other device, an abnormality notification receiving unit that receives a notification that the communication is abnormal from the other device;
With
The other device is
A second free-run counter that outputs a count value associated with the count value of the first free-run counter;
A receiving unit for receiving the serial data generated in the one device;
A communication abnormality detection unit for determining whether or not the serial data has been normally received by the reception unit;
When the communication abnormality detection unit determines that the serial data is not normally received in the reception unit, a communication abnormality notification unit that notifies the one device to that effect,
When the serial value received by the receiving unit does not include the counter value, the timing point corresponding to the sensor state change is specified based on the information indicating the detection state of the sensor included in the serial data, When the serial value received by the receiving unit includes the counter value, information indicating the detection state of the sensor included in the serial data, the counter value, the first free-run counter, and the second free-run counter Based on the correspondence relationship of the run counter, a timing start point identifying unit that identifies a timing start point corresponding to the state change of the sensor,
An operation control unit that executes the specific drive operation when a pre-designated time has elapsed from the timing start point specified by the timing start point specifying unit;
An image forming apparatus.
  The other device is an image forming apparatus main body including an image forming unit that forms an image on a recording medium, and the one device is a paper feeding device that supplies the recording medium to the image forming apparatus main body, The sensor is a sensor that detects that the recording medium has been normally fed, and a specific driving operation by the operation control unit causes the recording medium supplied from the paper feeding device to the image forming unit. The image forming apparatus according to claim 1, wherein the image forming apparatus is a drive of a conveying roller for conveying.   The one apparatus is an image forming apparatus main body including an image forming unit that forms an image on a recording medium, and the other apparatus is supplied with the recording medium on which an image is formed in the image forming apparatus main body. A post-processing device, wherein the sensor is a sensor that detects that the recording medium has been normally carried out of the image forming apparatus main body, and a specific driving operation by the operation control unit is performed by the image forming apparatus main body. The image forming apparatus according to claim 1, wherein the image forming apparatus is a drive of a conveyance roller that conveys the recording medium unloaded from the recording medium to a post-processing execution unit that performs post-processing.

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