JP2010276930A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve usability by carrying out an automatic paper ejecting action while preventing an occurrence of jamming which is difficult to remove manually. <P>SOLUTION: The image forming apparatus includes: a jamming type determination section 302 for determining the type of jamming based on the information from a sensor input section 206 when the occurrence of jamming in sheet material is determined by an engine control section 202; a jamming type storing section 303 for storing the jamming type information which is decided by the jamming type determination section 302; and a jamming position determination means 301 for determining the position of the sheet material when the jamming occurs based on the information from the sensor input section 206. In this case, the engine control section 202 determines whether or not the automatic paper ejecting action is carried out according to the position of the sheet material that is determined by the jamming position determination means 301 and the jamming type information stored to the jamming type storing section 303 when the jamming occurs. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that processes and conveys a sheet material by an electrophotographic copying machine such as a printer, a copying machine, and a facsimile machine, and performs automatic sheet material discharge operation when a sheet material jam occurs. It is about control.

  Conventionally, in a copying machine or the like, due to the sheet material (paper) condition, the device condition, and the surrounding environment of the device, the sheet material is jammed on the path from sheet feeding to paper discharge (hereinafter referred to as “paper jam”). , Called jam). Once a jam occurs, after detecting the position where the jam has occurred, the user directly opens the door of the copying machine or the like to remove the jammed sheet material, and then returns to normal operation. As described above, in the conventional case, when a jam occurs, the user has to remove the jammed sheet material directly, and in that process, the user's hand may be stained with toner.

  Therefore, as a known technique, there is a technique for performing control so that an automatic paper discharge operation can be performed without manually removing a jammed sheet material depending on the type of jam. In Patent Document 1, the number of occurrences of a specific jam is counted, and an automatic paper discharge operation is performed until the number of times exceeds a certain threshold, after which the user manually removes the jammed sheet material. An invention for performing is also disclosed. Thus, by determining whether or not to perform the automatic paper discharge operation, it is possible to reduce the user's effort as much as possible.

Japanese Patent No. 0820626

  However, if an automatic paper discharge operation is always performed when a certain jam occurs, it may be difficult to remove the jammed sheet material. An example is shown in FIG. If the sheet material S1 of the preceding paper (the sheet material fed first) stops at the position shown in FIG. 4 due to a conveyance failure or the like, the following paper (sheet material fed later) The sheet material S2 is present at a position as shown in FIG. In a copying machine or the like, if the discharge sensor 115 cannot detect the leading edge of the sheet material S1 within a predetermined time, it is determined that a jam has occurred. Thus, a predetermined time is required to actually determine a jam. Therefore, there is a possibility that the sheet material S2 of the succeeding paper is conveyed for a predetermined time until it is determined to be jammed. May hit you. In such a case, as shown in FIG. 5, the sheet material S2 has, for example, an irregular crease at the tip.

  When stopping by jam after a predetermined time, it is conceivable that the user removes only the sheet material S1 stopped at a position where it can be easily seen. When the user removes only the sheet material S1 and closes the door, the copying machine or the like re-evaluates the presence or absence of the sheet material remaining in the machine and determines whether or not an automatic paper discharge operation is performed. As shown in FIG. 5, the sheet material S2 is detected by the pre-feed sensor 104, and it is determined that there is a sheet. . However, since the leading edge of the sheet material S2 has, for example, an irregular crease, when the sheet material S2 is automatically discharged, a bellows-like crease is formed in the sheet material S2 as shown in FIG. There is a possibility of forming a jam (hereinafter referred to as a bellows-like jam). Thus, once it becomes a bellows-shaped jam, it will become difficult for a user to remove this sheet material S2, and usability may fall.

  However, if only the special situation is considered and the automatic paper discharge operation is not performed, the user must manually remove the sheet material every time a jam occurs. Further, as in Patent Document 1, such a problem is caused by the method of separating the automatic paper discharge operation according to the result of counting the number of times a specific jam has occurred and the case where the user manually removes the jam. It cannot be solved.

  The present invention has been made under such circumstances, and an object of the present invention is to perform an automatic paper discharge operation while preventing jamming that is difficult to remove manually.

  In order to solve the above problems, the present invention comprises the following arrangement.

  (1) A detection unit that detects a position of the sheet material, and a control unit that determines whether or not a jam of the sheet material has occurred based on a detection result of the detection unit, wherein the control unit generates the jam. An image forming apparatus capable of performing an automatic paper discharge operation for discharging the sheet material in the image forming apparatus to the outside of the image forming apparatus when the control unit determines that the sheet material has jammed. A determination unit that determines the type of the jam based on a detection result of the detection unit, a storage unit that stores information on the type of the jam determined by the type determination unit, and the detection unit. Position determination means for determining the position of the sheet material when the jam occurs based on the detection result of the detection, and the control means is determined by the position determination means when the jam occurs Depending on the position and the type of information of the jam, which is stored in the storage means over preparative material, the image forming apparatus characterized by determining whether or not to perform the automatic sheet discharging operation.

  According to the present invention, an automatic paper discharge operation can be performed while preventing the occurrence of a jam that is difficult to remove manually, and usability is improved.

1 is a diagram illustrating an outline of an image forming apparatus according to first to third embodiments. The block diagram which shows the structure of the control system which concerns on Examples 1-3. The block diagram which shows the engine control which concerns on Examples 1-3. The figure which shows the positional relationship of a preceding sheet and a succeeding sheet when conveyance of a preceding sheet has stopped The figure showing the positional relationship between the preceding sheet and the succeeding sheet when the preceding sheet ejection delay jam is confirmed The figure which shows the succeeding paper at the time of performing automatic paper discharge operation with respect to the succeeding paper from the state of FIG. The figure which shows the positional relationship of a preceding sheet and a succeeding sheet when a preceding sheet stops by discharge delay jam. A diagram showing the positional relationship between the preceding sheet and the succeeding sheet when the preceding sheet is stopped due to a discharge jam. 1 is a flowchart illustrating control processing according to the first embodiment. Diagram showing the situation when paper feed delay jam occurs Diagram showing the situation when a refeed delay jam has occurred The figure which shows the paper feed delay jam where the tip does not reach the pre-feed sensor 7 is a flowchart illustrating control processing according to the second embodiment. 10 is a flowchart illustrating determination as to whether or not to perform an initial operation when the power is turned on according to the third embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. Here, an example in which the present invention is applied to an electrophotographic laser beam printer is shown as an example, but the present invention can also be applied to an image forming apparatus such as a copying machine or a laser facsimile, an ink jet type image forming apparatus, or the like. Further, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are intended to limit the technical scope of the present invention only to those unless otherwise specified. It is not a thing.

[Configuration of Image Forming Apparatus]
The image forming apparatus according to the first embodiment will be described with reference to FIGS. First, the overall configuration of the image forming apparatus will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view of a laser beam printer 100 that is an image forming apparatus according to this embodiment. A laser beam printer 100 (hereinafter simply referred to as a printer 100) includes a photosensitive drum 111 for forming an image. Around the photosensitive drum 111, a developing roller 109, a charging roller 110, and a transfer roller 108 are sequentially arranged. The developing roller 109 develops the electrostatic latent image formed on the photosensitive drum 111 by exposure with toner. The charging roller 110 charges the photosensitive drum 111 with electric charges. The transfer roller 108 transfers the toner image obtained by development onto the sheet material. The photosensitive drum 111, the developing roller 109, and the charging roller 110 are integrated to form a toner cartridge 112.

  In FIG. 1, reference numeral 114 denotes a laser, and 113 denotes a mirror that reflects the laser in order to irradiate the photosensitive drum 111 with the laser.

  As shown in FIG. 2, the engine control unit 202 that has received the print information from the printer controller 201 instructs the sheet conveyance control unit 203 to convey the sheet material. The sheet material is started to be fed from the sheet feeding tray by the sheet feeding roller 102 (or 152, 162), and is conveyed to the conveying path 140 through the intermediate roller 103 (or 153, 163) and the pre-feed sensor 104. Next, the sheet material conveyed by the intermediate roller 103 is conveyed to the photosensitive drum 111 through the top sensor (TOP sensor) 106 and the paper width sensor 107. The top sensor 106 starts to measure the length of the sheet material being conveyed when the sensor is detected, and the paper width sensor 107 detects the width of the sheet material. The toner image is transferred when the sheet material passes between the photosensitive drum 111 and the transfer roller 108 (transfer nip portion). The sheet material to which the toner has been transferred passes through the fixing device 120. The fixing device 120 includes a heated heater 119, a thermistor 118 that detects the temperature of the heater 119, a fixing film 117 that applies heat, and a pressure roller 116 that applies pressure to the sheet material. As the sheet material passes between the fixing film 117 and the pressure roller 116 (fixing nip portion), the toner is fixed to the sheet material. Reference numeral 115 denotes a paper discharge sensor that detects the sheet material after fixing. The sheet material on which the toner is fixed is conveyed to the conveyance path 141 through the conveyance roller 121.

  In the case of single-sided printing, the paper is discharged by the paper discharge roller 123, and in the case of double-sided printing, the double-sided printing motor starts reverse rotation, and the sheet material in the conveyance path 141 prints on the second surface, Then, the sheet is conveyed to the duplex conveyance path 142 by the duplex conveyance roller 131. The sheet material is conveyed again to the conveyance path 140 via the conveyance roller 133, and the toner image is transferred to the second surface by the photosensitive drum 111 and the transfer roller 108. The sheet material carrying the toner image is fixed on the toner image by the fixing device 120 and is discharged by the paper discharge roller 123. Note that the printer 100 according to the present exemplary embodiment has a configuration including three paper feed trays. Reference numeral 105 denotes a conveyance roller, 132 denotes a refeed sensor, 122 denotes a face-up (FU) tray, and 130 denotes a duplex unit.

[Control system configuration]
FIG. 2 is a block diagram showing a configuration of a control system that controls each unit shown in FIG. In FIG. 2, a printer controller 201 develops an image code from an external device such as a host computer into bit data necessary for printing by a printer, reads internal information of the printer engine by communication, and displays it. The engine control unit 202 has a one-chip microcomputer with a built-in ROM and RAM, and similarly transmits and receives information to and from the printer controller 201 having the microcomputer by serial communication. The engine control unit 202 controls each unit of the printer engine so as to operate according to an instruction from the printer controller 201 and notifies the printer controller 201 of internal printer information.

  A sheet conveyance control unit 203 controls the driving of the sheet feeding roller 102 for feeding the sheet material and the rotation and stop conveyance control of the conveyance roller 105 for conveying the sheet material in accordance with an instruction from the engine control unit 202. . A high voltage control unit 204 performs output control of each of the high voltage power sources for charging, development, and transfer based on an instruction from the engine control unit 202. An optical system control unit 205 drives / stops the scanner motor and blinks the laser 114 in accordance with an instruction from the engine control unit 202. A sensor input unit 206 transmits information from the paper presence sensor, the top sensor 106, the paper width sensor 107, and the paper discharge sensor 115 to the engine control unit 202. A fixing temperature control unit 207 adjusts the temperature of the fixing device 120 to a temperature designated by the engine control unit 202. A duplex unit control unit 208 controls the duplex unit 130 in accordance with an instruction from the engine control unit 202.

[Configuration and control of engine control unit]
Next, this embodiment will be specifically described. FIG. 3 is a block diagram showing the configuration of engine control in this embodiment. FIG. 4 shows the positional relationship between the sheet material S1 which is the preceding sheet and the sheet material S2 which is the succeeding sheet (sheet material fed later) when the conveyance of the preceding sheet (sheet material fed first) is stopped. FIG.

  The jam type determination unit 302, which is a type determination unit, cannot detect the front end of the sheet material S1 by the paper discharge sensor 115 from the sensor input unit 206 after a predetermined time from when the top sensor 106 detects the front end of the sheet material S1. When the information is transmitted, it is determined as a paper discharge delay jam. Further, during continuous printing, as shown in FIG. 4, the sheet material S2, which is a subsequent sheet, has already started feeding, and when a jam of the sheet material S1 is actually determined after a predetermined time, it is shown in FIG. The positional relationship is as follows. As described above, if an automatic paper discharge operation for automatically discharging the sheet material to the outside of the image forming apparatus is performed in this state, the sheet material S2 jammed as shown in FIG. 6 (hereinafter also referred to as jammed paper). May be difficult to remove.

  First, when the jam type determination unit 302 determines that the paper discharge delay jam has occurred, the jam type storage unit 303 stores the jam type. Specifically, information indicating that “paper discharge delay jam has occurred” is stored in, for example, a RAM which is a volatile memory of the CPU. Further, since there is the sheet material S1 conveyed to the fixing nip portion of the fixing device 120, the user is prompted to remove the jammed paper. At this time, the user may open the door of the printer 100 to remove the sheet material S1 and close the door without noticing the presence of the sheet material S2. Therefore, in order to determine whether or not there is a possibility that the leading edge of the sheet material S2 that is the succeeding paper has hit the trailing edge of the removed sheet material S1 that is the preceding paper, the jam position determination unit 301 includes a prefeed sensor. It is determined whether or not the sheet material S2 is conveyed to the position 104. That is, even if the sheet material S1 is removed, if the pre-feed sensor 104 detects the sheet material S2, the sheet material S2, which is a subsequent sheet, during a predetermined time until the jam of the sheet material S1 is determined. It is judged that it has also been transported. For this reason, the sheet material S2 may have, for example, an irregular fold formed at the tip (see FIG. 5). In this case, if the automatic sheet discharge operation is performed as it is, the sheet material S2 may be jammed with a bellows-like fold (hereinafter also referred to as a bellows-like jam) (see FIG. 6). In such a case, even if the user closes the door, the engine control unit 202 does not perform an automatic paper discharge operation or an initial operation for the next printing (hereinafter referred to as an initial operation), and a jam occurs. The user is notified that the sheet material S2 exists.

  After that, the engine control unit 202 performs an initial operation only after the user removes the sheet material S2. In addition, when both the sheet materials S1 and S2 are removed when the user first opens the door, the engine control unit 202 performs the initial operation.

  In addition, when a paper discharge delay jam occurs and stops at the position shown in FIG. 7, if the user removes only the sheet material S1 and closes the door, the jam position determination unit 301 performs prefeed. It is determined that the sensor 104 does not have the sheet material S2. In this case, there is no possibility of occurrence of a bellows-like jam as shown in FIG. 6, so the engine control unit 202 performs an initial operation.

  Further, consider a case where the user has removed the sheet material S1 of the preceding paper when a paper discharge jam occurs such that the trailing edge of the sheet material S1 cannot be detected by the paper discharge sensor 115 as shown in FIG. When it is determined that a paper discharge retention jam has occurred, the jam type determination unit 302 stores in the jam type storage unit 303 that the jam type is a paper discharge retention jam. As shown in FIG. 8, in the paper discharge stay jam, a situation in which the rear end of the sheet material S1 and the front end of the sheet material S2 do not occur does not occur. The jam position determination unit 301 determines that the pre-feed sensor 104 has the sheet material S2. However, since the jam type stored in the jam type storage unit 303 is a paper discharge retention jam, the engine control unit 202 performs an automatic paper discharge operation when the user closes the door in the case of this jam and performs an initial. Perform the action.

[Control of automatic paper discharge after jam removal processing]
The processing of this embodiment will be described with reference to FIG. FIG. 9 is a flowchart showing the control for determining whether or not to perform the initial operation after the jam processing is performed by the user after the jam has occurred. The jam processing performed by the user is processing in which the user manually removes a sheet material that has become jammed on the conveyance path from the conveyance path.

  When a jam occurs during printing (step 901, hereinafter referred to as “S901”), the jam type determination unit 302 determines the type (jam type) of the generated jam (S902). After the determination by the jam type determination unit 302, the determined jam type is stored in the jam type storage unit 303 (for example, CPU RAM) (S903). The engine control unit 202 notifies the user that a jam has occurred (S904). After the engine control unit 202 notifies the user of the occurrence of the jam, the jam processing by the user is performed (S905). The information that the detection means such as a door opening / closing detection sensor (not shown) detects that the user has opened / closed the door is sent from the sensor input unit 206 to the engine control unit 202, so that the engine control unit 202 is controlled by the user. Determine the status of jam handling.

  When it is detected that the jam processing by the user is finished and the door is closed, the engine control unit 202 determines whether or not the sheet material remains in the printer 100 (hereinafter referred to as “inside”) in the image forming apparatus. It judges from the information of 206 (S906). If the engine control unit 202 determines that no sheet material remains in the machine, the engine control unit 202 starts an initial operation (S911). Further, when the engine control unit 202 determines that the sheet material remains in the apparatus, the paper discharge sensor 115 determines whether or not the sheet material remains around the fixing device 120 by the jam position determination unit 301 ( S907). If the engine control unit 202 determines in S907 that the sheet material remains around the fixing device 120, the process returns to S904 to perform jam processing by the user. Note that the jam position determination unit 301 determines that the sheet material is around the fixing device 120 when the paper discharge sensor 115 cannot detect the trailing edge of the sheet material after a predetermined time since the paper discharge sensor 115 detects the leading edge of the sheet material. It is determined that it remains in.

  If the engine control unit 202 determines in S907 that no sheet material remains around the fixing device 120, the jam position determination unit 301 determines whether there is a sheet material in the pre-feed sensor 104 (S908). If the jam position determination unit 301 determines that no sheet material remains in the pre-feed sensor 104 (FIG. 7), the engine control unit 202 performs an automatic paper discharge operation (S910). When the jam position determination unit 301 determines that the sheet material remains in the pre-feed sensor 104, the engine control unit 202 determines whether the jam type stored in the jam type storage unit 303 is a paper discharge delay jam. (S909). If the stored jam type is not a paper discharge delay jam (FIG. 8), the engine control unit 202 performs an automatic paper discharge operation (S910) and performs an initial operation (S911). If the engine control unit 202 determines in step S909 that the paper discharge delay jam has occurred (FIG. 5), the process returns to step S904, and the user performs jam processing.

  The engine control unit 202 starts an initial operation in S911, and stores jam type information (for example, information such as “paper discharge delay jam” and “paper discharge accumulated jam”) stored in the jam type storage unit 303 in S912. to erase. When the jam type storage unit 303 is, for example, a CPU RAM, the stored jam information is not erased unless the printer 100 is turned off or an initial operation is performed.

  As described above, in this embodiment, when a paper discharge delay jam occurs, it is determined whether or not the automatic paper discharge operation is performed using the detection result of the pre-feed sensor 104. According to the present embodiment, it is possible to perform an automatic paper discharge operation while preventing a jam that is difficult for the user to remove, and usability is improved.

  In the first embodiment, the configuration in which it is determined whether or not the automatic paper discharge operation is performed for a jam that occurs during continuous printing has been described. In the second embodiment, not only continuous printing but also single-sheet printing will be described. The configuration of the printer 100, the configuration of the control system, and the configuration of the engine control unit according to the present embodiment are the same as those illustrated in FIGS. 1 to 3 described in the first embodiment, and a description thereof will be omitted. To do.

[Jam that occurs when printing one sheet]
The vicinity of the conveyance path 140 between the pre-feed sensor 104 and the top sensor 106 has a complicated mechanical configuration, and it is not easy for the user to perform jam processing, and the above-described bellows-like jam is likely to occur. Therefore, it is necessary not to consider only that the leading edge of the succeeding sheet hits the trailing edge of the preceding sheet shown in the first embodiment, but to pay attention to the jam in this section.

  As a case where the sheet material is likely to stop near the conveyance path 140 and a bellows-like jam is likely to occur, the following jam can be considered. For example, as shown in FIG. 10, there may be a case where a paper feed delay jam has occurred in which the top sensor 106 cannot detect the leading edge of the sheet material even after a predetermined time has elapsed. In addition, as shown in FIG. 11, when refeeding from the duplex unit 130, a refeed delay jam may occur in which the top sensor 106 cannot detect the leading edge of the sheet material even after a predetermined time. . However, if all of the paper feed delay jams in which the top sensor 106 cannot detect the leading edge of the sheet material even after a predetermined time has elapsed are jams that do not perform the automatic paper discharge operation, the usability may be reduced. Therefore, as shown in FIG. 12, the pre-feed sensor 104 does not detect the leading edge of the sheet material, that is, a sheet-feed delay jam in which the sheet material has not reached the pre-feed sensor 104 is automatically detected without being manually removed. Paper to be discharged. This prevents jamming that is difficult to remove without reducing usability.

[Control of automatic paper discharge after jam removal processing]
The processing of this embodiment will be described with reference to FIG. FIG. 13 is a flowchart showing control for determining whether or not to perform an initial operation after the user performs jam processing after a jam has occurred. FIG. 13 is obtained by further adding processing to the processing of FIG. 9 described in the first embodiment. The same process is given the same step number.

  When a jam occurs during printing (S901), the jam type determination unit 302 determines the jam type (S902). After the determination in S902, the jam type determination unit 302 stores the jam type in the jam type storage unit 303 (for example, the RAM of the CPU) (S903). The engine control unit 202 notifies the user that a jam has occurred (S904). After the notification by the engine control unit 202, manual jam processing by the user is performed (S905). As described in the first embodiment, the engine control unit 202 determines the jam processing status by opening and closing the door of the user.

  When the jam processing by the user is completed and the door of the printer 100 is closed, the engine control unit 202 determines from the information in the sensor input unit 206 whether or not sheet material remains in the apparatus (S906). If the engine control unit 202 determines that no sheet material remains in the machine, the engine control unit 202 starts an initial operation (S911). If the engine control unit 202 determines that no sheet material remains in the apparatus, the engine control unit 202 determines whether no sheet material remains around the fixing device 120 (S907). If it is determined that the sheet material remains, S904 is performed. Returning to the process, the jam processing by the user is performed.

  If the engine control unit 202 determines that no sheet material remains around the fixing device 120, the jam position determination unit 301 determines whether or not there is a sheet material in the pre-feed sensor 104 (S908). If the jam position determination unit 301 determines in S908 that no sheet material remains, the engine control unit 202 performs an automatic paper discharge operation (S910).

  If the jam position determination unit 301 determines that the sheet material remains in the pre-feed sensor 104, the engine control unit 202 determines whether the jam type stored in the jam type storage unit 303 is a paper discharge delay jam (S909). ). If the engine control unit 202 determines that the paper discharge delay jam has occurred, the process returns to step S904 and the user performs jam processing. If the engine control unit 202 determines in step S909 that the jam is not a paper discharge delay jam, the engine control unit 202 determines whether the jam type stored in the jam type storage unit 303 is a paper feed delay jam (S1301). If the engine control unit 202 determines in step S1301 that a paper feed delay jam has occurred (FIG. 10), the process returns to the processing in step S904 to perform jam processing by the user. If the engine control unit 202 determines in S1301 that the jam is not a paper feed delay jam, it determines whether the jam type stored in the jam type storage unit 303 is a refeed delay jam (S1302). If the engine control unit 202 determines in step S1302 that the paper refeed delay jam has occurred (FIG. 11), the process returns to step S904 to perform jam processing by the user. If the engine control unit 202 determines in step S1302 that it is not a paper refeed delay jam (FIG. 12), an automatic paper discharge operation is performed (S910), and an initial operation is performed (S911).

  Further, when the engine control unit 202 starts the initial operation in S911, the engine control unit 202 deletes the jam type information stored in the jam type storage unit 303 (S912). As in the first embodiment, the jam type information is not erased unless the printer 100 is turned off or an initial operation is performed when the jam type storage unit 303 is a RAM of a CPU, for example.

  As described above, in this embodiment, not only when a paper discharge delay jam occurs, but also when a paper feed delay jam or a paper refeed delay jam occurs even with a single print, an automatic paper discharge operation using the pre-feed sensor 104 is performed. It is configured to determine whether or not to perform. According to the present embodiment, it is possible to perform an automatic paper discharge operation while preventing a jam that is difficult for the user to remove, and usability is improved.

  In the first and second embodiments, the configuration has been described in which it is determined whether or not an automatic paper discharge operation is performed for a jam that has occurred during printing. In the third embodiment, a case where the power is turned off (turned off) after a jam has occurred will be described. The configuration of the printer 100 used in this embodiment, the configuration of the control system that controls each unit, and the configuration of the engine control are the same as those in FIGS. .

[If the power is turned off after jam processing]
In the first and second embodiments, if the user turns off the printer 100 when performing jam processing after a jam has occurred, the information stored in the CPU RAM, which is the jam type storage unit 303, is also deleted. For example, let us consider a case where a paper feed delay jam occurs as in the second embodiment and the power is turned off with the sheet material remaining in the pre-feed sensor 104 (see FIG. 10). Consider processing shown in FIG. 14 when checking whether or not the initial operation by the engine control unit 202 is performed when the printer 100 is turned on (turned on).

  When the user turns on the printer 100, the engine control unit 202 first checks in step S1401 whether sheet material remains in the apparatus. In the case of the paper feed delay jam shown in FIG. 10, the engine control unit 202 determines in S1401 that the sheet material remains, and in S1402, determines whether there is no sheet material remaining around the fixing device 120.

  In the case of FIG. 10, the engine control unit 202 determines that the sheet material does not remain around the fixing device 120 in S1402, and determines that the sheet material remains in the pre-feed sensor 104 in S1403. Since the user has turned off the printer 100 once during the jam processing, there is no jam information stored in the jam type storage unit 303 used for the determination in S1404, S1405, and S1406. As a result, the engine control unit 202 performs an automatic paper discharge operation in step S1409, which may cause a bellows-like jam that is difficult for the user to remove as shown in FIG.

  Therefore, in this embodiment, NVRAM (nonvolatile random access memory) which is a nonvolatile memory is used as the jam type storage unit 303 instead of the CPU RAM, and the jam type determination unit 302 uses the jam type as the jam type storage unit 303. Store in NVRAM. As a result, even when the user turns off the printer 100 during jam processing, the engine control unit 202 can make the determinations of S1404 to S1406 using the information stored in the NVRAM.

[Control of automatic paper discharge operation after power is turned on]
The processing of this embodiment will be described with reference to FIG. FIG. 14 is a flowchart showing control for determining whether or not the engine control unit 202 performs the initial operation when the user turns on the printer 100.

  When the user turns on the printer 100, the engine control unit 202 determines from the information in the sensor input unit 206 whether sheet material remains in the apparatus (S1401). If it is determined in S1401 that no sheet material remains in the machine, the engine control unit 202 starts an initial operation (S1411). If the engine control unit 202 determines in S1401 that the sheet material remains in the apparatus, the engine control unit 202 checks whether or not the sheet material remains around the fixing device 120 (S1402). If the engine control unit 202 determines that the sheet material remains in S1402, the engine control unit 202 notifies the user that the sheet is jammed (S1407), and performs jam processing by the user (S1408). After the jam processing in S1408, the engine control unit 202 starts an initial operation when determining that there is no sheet material in the machine (S1411). The status of the jam processing by the user is determined by the user's door opening / closing described in the first embodiment.

  If the engine control unit 202 determines in S1410 that there is a sheet material in the machine after the jam processing in S1408, the process returns to S1402.

  If the engine control unit 202 determines in S1402 that no sheet material remains around the fixing device 120, the engine control unit 202 determines whether there is no sheet material remaining in the pre-feed sensor 104 (S1403). If it is determined in S1403 that no sheet material remains in the pre-feed sensor 104, the engine control unit 202 performs an automatic paper discharge operation (S1409). If it is determined in S1410 that there is no sheet material in the apparatus, an initial operation is performed. Is started (S1411). If the engine control unit 202 determines in S1410 that there is a sheet material in the machine, the process returns to S1402.

  If the engine control unit 202 determines in S1403 that the sheet material remains in the pre-feed sensor 104, it performs the following processing. That is, the engine control unit 202 determines whether the jam type stored in the NVRAM as the jam type storage unit 303 is a paper discharge delay jam, a paper feed delay jam, or a refeed delay jam in S1404, S1405, and S1406, respectively. to decide. If the engine control unit 202 determines in S1404, S1405, and S1406 that the stored jam types are not a paper discharge delay jam, a paper feed delay jam, and a refeed delay jam, respectively, an automatic paper discharge operation is performed (S1409). . If it is determined in S1410 that there is no sheet material in the machine, the engine control unit 202 starts an initial operation (S1411). If the engine control unit 202 determines in S1410 that there is a sheet material in the machine, the process returns to S1402.

  If the engine control unit 202 determines in S1404, S1405, and S1406 that the stored jam types are a paper discharge delay jam, a paper feed delay jam, and a refeed delay jam, the following processing is performed. That is, the engine control unit 202 notifies the user of a jam (S1407), and the user performs jam processing (S1407). After the jam processing by the user in S1408, the engine control unit 202 starts an initial operation when determining that there is no sheet material in the machine (S1411). After the jam processing by the user in S1408, if the engine control unit 202 determines that there is a sheet material in the machine, the process returns to S1402.

  Further, when starting the initial operation in S1411, the engine control unit 202 deletes the jam type information stored in the jam type storage unit 303 from the NVRAM (S1412). The timing at which the jam type determination unit 302 stores the jam type information in the NVRAM is the same as in the first and second embodiments, and is after the jam type determination unit 302 determines the jam type after the occurrence of the jam.

  As described above, in the third embodiment, the jam type is stored using the NVRAM instead of the CPU RAM as the jam type storage unit 303. As a result, even if the user turns off the power of the image forming apparatus at the time of jam processing, it can be determined whether or not to perform the automatic paper discharge operation from the information in the NVRAM when the power is turned on next time. According to the present embodiment, it is possible to perform an automatic paper discharge operation while preventing a jam that is difficult for the user to remove, and usability is improved.

202 Engine control unit 206 Sensor input unit 301 Jam position determination unit 302 Jam type determination unit 303 Jam type storage unit

Claims (4)

Detection means for detecting the position of the sheet material, and control means for determining whether or not a jam of the sheet material has occurred based on a detection result of the detection means, wherein the control means determines that the jam has occurred. An image forming apparatus capable of performing an automatic paper discharge operation for discharging the sheet material in the image forming apparatus to the outside of the image forming apparatus when
Type determining means for determining the type of the jam based on a detection result by the detecting means when the control means determines that a jam of the sheet material has occurred,
Storage means for storing information on the type of jam determined by the type determination means;
Position determination means for determining the position of the sheet material when the jam occurs based on the detection result of the detection means;
With
When the jam occurs, the control means performs the automatic paper discharge operation according to the position of the sheet material determined by the position determination means and the information on the jam type stored in the storage means. An image forming apparatus that determines whether or not to perform. The image forming apparatus according to claim 1,
The image forming apparatus according to claim 1, wherein when the control unit determines not to perform the automatic sheet discharge operation, the control unit notifies the user to remove the sheet material. The image forming apparatus according to claim 1, wherein
The image forming apparatus, wherein the storage unit is a volatile memory. The image forming apparatus according to claim 1, wherein
The image forming apparatus, wherein the storage unit is a nonvolatile memory.

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