Image forming device

Abstract

To reduce non-paper feed while suppressing reduction in a life of a consumable item.SOLUTION: An image forming apparatus comprises: a paper feed cassette 21 and a paper feed tray 51 on which recording materials are loaded; feeding rollers 22, 52 that feed the recording materials 26, 56 loaded on the paper feed cassette 21 and the paper feed tray 51 to a transport path; process cartridges 5 that perform image formation on the recording materials; a registration sensor 27 that detects non-paper feed in which the recording materials 26, 56 are not fed from the paper feed cassette 21 and the paper feed tray 51; and an engine control unit 230 that controls the feeding of the recording materials 26, 56. When the registration sensor 27 detects non-paper feed (S102 NO), the engine control unit 230 determines whether to re-feed the recording materials on the basis of the re-feeding frequency that is the number of times the recording materials 26, 56 are re-fed, and any one of a prescribed threshold determined in advance, a threshold based on a remaining life of the process cartridges 5, and a threshold based on an amount of recording material 26 loaded on the paper feed cassette 21 (S103-S109).SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus such as a copying machine or a printer. [Background technology]

[0002] Image forming apparatuses such as copiers and printers include a stacking section for stacking recording materials and a feeding mechanism for feeding the recording materials stacked on the stacking section to a conveying path. The feeding mechanism generally uses a feeding roller to feed the recording materials stacked on the stacking section to the conveying path one by one. In addition, when the recording materials do not reach a recording material detection position provided downstream of the conveying path from the feeding start position of the stacking section within a predetermined time, conventional image forming apparatuses determine that a jam has occurred in which the recording materials are not fed from the stacking section (hereinafter, referred to as no-feed). In addition, the image forming apparatus includes a feeding retry function for retrying (retransmitting) the recording materials a predetermined number of times as a relief measure in the event of no-feed. In the image forming apparatus, the feeding retry function feeds the recording materials from the stacking section again to form an image, thereby reducing the occurrence of no-feed. For example, in regard to such feeding retry control, Patent Document 1 discloses a setting means for setting the number of feeding retries to an arbitrary number depending on the wear state of the feeding mechanism (for example, the feeding roller).

[0003] In addition, in a color image forming apparatus that forms a color image on a recording material, in order to increase the number of sheets of recording material on which images are formed per unit time (throughput), the image forming operation may be started before the feeding of the recording material is started. Therefore, when it is determined that a non-feed has occurred, a recovery process is performed in which the surface of the image carrier of the image forming unit for each color is cleaned to remove the toner image that has already been formed, and a feeding retry is prepared. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-334935 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned conventional technology, in order to recover from non-feeding as much as possible, it is considered to increase the number of times of feeding retry. However, if non-feeding occurs frequently and feeding retry is performed each time, the number of times of recovery processing for removing the toner image on the image carrier and cleaning the surface of the image carrier will also increase. As a result, there is a problem of shortening the life of consumables such as process cartridges due to increased toner consumption and wear of various rollers.

[0006] The present invention has been made under these circumstances, and has an object to reduce non-feeding while suppressing the shortening of the life span of consumables. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the present invention has the following configuration.

[0008] (1) The recording medium storing device has a first stacking section which is detachable, and a second stacking section on which the recording material can be manually inserted, The recording medium conveying device includes a stacking section on which recording materials are stacked, a feeding means for feeding the recording materials stacked on the stacking section to a conveying path, an image forming means for forming an image on the recording materials, a detection means for detecting a non-feed in which the recording materials are not fed from the stacking section, and a control means for controlling the feeding of the recording materials, and when the detection means detects the non-feed, the control means determines whether or not to re-feed the recording materials based on the number of re-feeds of the recording materials and any one of a predetermined threshold value, a threshold value based on the remaining life of the image forming means, and a threshold value based on the amount of the recording materials stacked on the stacking section. The predetermined threshold value is determined in accordance with the number of sheets of recording material that can be placed on the first stacking unit and the second stacking unit. 1. An image forming apparatus comprising: Effect of the Invention

[0009] According to the present invention, it is possible to reduce non-feeding while suppressing the shortening of the life span of consumables. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus according to first to third embodiments. [Diagram 2] FIG. 1 is a diagram showing the configuration of a recording material feeding mechanism according to the first embodiment; [Diagram 3] FIG. 1 is a functional block diagram of recording material feeding control according to a first embodiment of the present invention; [Figure 4] A flowchart showing a recording material feeding control sequence in the first embodiment. [Diagram 5] FIG. 1 is a diagram showing the configuration of a recording material feeding mechanism according to a second embodiment of the present invention; [Figure 6] FIG. 11 is a functional block diagram of recording material feeding control according to the second embodiment; [Figure 7] A flowchart showing a recording material feeding control sequence in the second embodiment. [Figure 8] FIG. 11 is a diagram showing the configuration of a recording material feeding mechanism according to the third embodiment. [Figure 9] FIG. 11 is a functional block diagram of recording material feeding control according to the third embodiment; [Figure 10] A flowchart showing a recording material feeding control sequence in the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. EXAMPLES

[0012] [Configuration of image forming device] An electrophotographic image forming apparatus to which the present invention is applicable will be described. FIG. 1 is a cross-sectional view showing the schematic configuration of a tandem-type color laser beam printer PR (hereinafter referred to as printer PR) in which a plurality of image forming units are arranged in parallel. The printer PR is configured to form a color image by superimposing on an intermediate transfer belt 11 toner images of four colors, yellow (Y), magenta (M), cyan (C), and black (K), which are generated in each process cartridge 5, which is an image forming unit. Each process cartridge 5 has the same configuration except for the different colors of toner. The suffixes Y, M, C, and K of the reference numbers of the members constituting the process cartridge 5 indicate that the members are process cartridges of the toner colors yellow, magenta, cyan, and black, respectively. In the following description, except for the case of referring to a member of a specific toner color, for the sake of convenience of explanation, the suffixes Y, M, C, and K of the reference numbers are omitted for members that do not need to distinguish the toner color.

[0013] Each process cartridge 5 has a photosensitive drum 1 as an image carrier, a charging roller 2 that charges the photosensitive drum 1 to a uniform potential, and a developing roller 3 that attaches toner contained in a toner container 6 to an electrostatic latent image generated on the photosensitive drum 1 to form a toner image. Each process cartridge 5 also has a drum cleaning blade 4 that removes toner from the photosensitive drum 1 (on the photosensitive drum), and a waste toner container 7 that accommodates the removed toner. Furthermore, below each process cartridge 5, a laser unit 8 is disposed that irradiates the photosensitive drum 1 with a laser beam based on an image signal to form an electrostatic latent image. The charging roller 2 charges the surface of the photosensitive drum 1, which rotates in the direction of the arrow (clockwise direction) in the figure, to a predetermined negative potential by applying a predetermined negative voltage. Then, an electrostatic latent image is formed on the surface of the photosensitive drum 1 by applying a laser beam according to the image signal from the laser unit 8. Then, a predetermined negative voltage is applied to the developing roller 3 (developing section), so that the negatively charged toner is attached to the electrostatic latent image on the photosensitive drum 1. As a result, toner images of yellow (Y), magenta (M), cyan (C) and black (K) are formed on the photosensitive drum 1 of each process cartridge 5.

[0014] The intermediate transfer belt unit is composed of an intermediate transfer belt 11, a drive roller 12, a tension roller 13, and an opposing roller 15. In addition, a primary transfer roller 10 is disposed inside the intermediate transfer belt 11 at a position facing each photosensitive drum 1. The photosensitive drum 1 of each process cartridge 5 and the intermediate transfer belt 11 rotate in the direction of the arrow in the figure, and the toner images formed on each photosensitive drum 1 are transferred to the intermediate transfer belt 11 in a superimposed manner in sequence by applying a positive polarity voltage to the primary transfer roller 10. That is, the toner images on the photosensitive drum 1 are transferred to the intermediate transfer belt 11 in the order of yellow (Y), magenta (M), cyan (C), and black (K) in a superimposed manner, and are transported to the secondary transfer roller 14 in a state in which the four color toner images are superimposed.

[0015] (Cassette feeding mechanism) The cassette feeding mechanism 20 includes a paper feed cassette 21 (first stacking section) that contains recording material 26 placed on a paper feed tray 29 and is detachable from the printer PR, and a feed roller 22 that feeds the recording material 26 from the paper feed cassette 21. The cassette feeding mechanism 20 also includes a conveying roller 23 that conveys the recording material 26 fed from the feed roller 22 to a conveying path, and a separation roller 24 that separates and conveys the recording materials 26 one by one so that the recording materials 26 are not fed in duplicate. The registration roller pair 25 conveys the recording material 26 conveyed from the cassette feeding mechanism 20 to the secondary transfer roller 14.

[0016] The cassette feeding mechanism 20 also has a paper cassette presence sensor 207 (see FIG. 2) and a paper surface sensor 28. The paper cassette presence sensor 207, which is a state detection means, detects whether the paper cassette 21 is attached to the printer PR. The paper surface sensor 28, which is a position detection unit, detects the uppermost recording material 26 placed on the paper feed tray 29 of the paper cassette 21. A registration sensor 27 is also disposed near the registration roller pair 25 on the conveying path between the registration roller pair 25 and the secondary transfer roller 14, and the registration sensor 27 detects the recording material 26 conveyed on the conveying path. The printer PR measures the time from when the recording material 26 in the paper cassette 21 is fed by the feed roller 22 to when it is detected by the registration sensor 27 using a system timer. If the registration sensor 27 does not detect the recording material 26 within a predetermined specified time from when the recording material 26 is fed, the printer PR determines that non-feed of the recording material 26 has occurred. Furthermore, the printer PR detects whether or not the paper feed cassette 21 is attached to the printer PR by the paper feed cassette presence / absence sensor 207. After a non-feed of the recording material 26 occurs, the printer FR determines, based on the detection result of the paper feed cassette presence / absence sensor 207, whether or not the paper feed cassette 21 has been attached or detached and the user has confirmed the state of the recording material 26 stored in the paper feed cassette 21.

[0017] When the fed recording material 26 is detected by the registration sensor 27 within a specified time and conveyed to the secondary transfer roller 14, the printer PR applies a positive voltage to the secondary transfer roller 14 to transfer the toner image on the intermediate transfer belt 11 to the recording material 26. As a result, the toner image on the intermediate transfer belt 11 is transferred to the conveyed recording material 26. The recording material 26 to which the toner image has been transferred is conveyed to the fixing device 30, where it is heated and pressed by the fixing film 31 and the pressure roller 32, so that the toner image is fixed to the recording material 26. The recording material 26 to which the toner image has been fixed is discharged to the outside of the printer PR by the discharge roller pair 33. Note that a toner image may remain on the intermediate transfer belt 11 (on the intermediate transfer belt) without being transferred to the recording material 26. The toner image remaining on the intermediate transfer belt 11 is conveyed to the cleaning blade 16a, where it is removed by the cleaning blade 16a, and the removed toner is collected in the waste toner container 16b.

[0018] (Manual feed mechanism) The printer FR of this embodiment also includes a manual feed mechanism 50 that feeds the recording material 26 that can be manually placed, in addition to the cassette feed mechanism 20 that feeds the recording material 26 from the paper feed cassette 21. The manual feed mechanism 50 has a paper feed tray 51 (second stacking section) on which the recording material 56 is placed, and a feed roller 52 that feeds the recording material 56 placed on the paper feed tray 51. The manual feed mechanism 50 also has a conveying roller 53 that conveys the recording material 56 fed from the feed roller 52 to a conveying path, and a separation roller 54 that separates and conveys the recording material 56 one by one so that the recording materials 56 are not fed in duplicate. The recording material 56 conveyed from the manual feed mechanism 50 is conveyed to the secondary transfer roller 14 by the registration roller pair 25, and the toner image on the intermediate transfer belt 11 is transferred onto the recording material 56. The operation after the toner image on the intermediate transfer belt 11 is transferred to the recording material 56 is the same as that in the case of the recording material 26 fed from the paper feed cassette 21 described above, and therefore a description thereof will be omitted.

[0019] The manual feed mechanism 50 also has a paper feed tray recording material presence / absence sensor 55, which is a recording material detection means, and the paper feed tray recording material presence / absence sensor 55 detects the presence / absence state of the recording material 56 on the paper feed tray 51. The printer PR uses a system timer to measure the time from when the recording material 56 on the paper feed tray 51 is fed by the feed roller 52, conveyed along the conveying path, and detected by the registration sensor 27. If the registration sensor 27 does not detect the recording material 56 within a predetermined specified time from when the recording material 56 is fed, the printer PR determines that a non-feed of the recording material 56 has occurred. The printer PR also detects the presence / absence state of the recording material 56 on the paper feed tray 51 using the paper feed tray recording material presence / absence sensor 55. After a non-feed of the recording material 56 has occurred, the printer PR determines whether the user has reloaded the recording material 56 to check the state of the recording material 56 on the paper feed tray 51, based on the detection result of the paper feed tray recording material presence / absence sensor 55. The printer PR detects that the recording material 56 has been reloaded when the paper feed tray recording material presence / absence sensor 55 detects that the recording material 56 has run out on the paper feed tray 51, and then detects that the recording material 56 is present (placed) on the paper feed tray 51, thereby detecting that the recording material 56 has been reloaded.

[0020] When the printer PR detects by the registration sensor 27 that a non-feed of the recording material 26 or the recording material 56 has occurred, the printer PR executes a retry of feeding the detected non-feed recording material in order to remedy the non-feed. When the printer PR determines that a non-feed has occurred again even after executing the feeding retry, the printer PR displays on the operation display unit (not shown) a message informing the user that a non-feed has occurred. When a non-feed of the recording material 26 has occurred, the printer PR displays on the operation display unit (not shown) instruction information for confirming whether the recording material 26 in the paper feed cassette 21 is correctly placed at a predetermined position. On the other hand, when a non-feed of the recording material 56 has occurred, the printer PR displays on the operation display unit (not shown) instruction information for confirming whether the recording material 56 on the paper feed tray 51 is correctly placed at a predetermined position.

[0021] In this embodiment, the occurrence of non-feeding is judged based on whether the registration sensor 27 detects the recording material 26 in the paper feed cassette 21 or the recording material 56 in the paper feed tray 51 within a predetermined specified time after the recording material 26 is fed. This embodiment is not limited to the above-mentioned method, and other methods capable of detecting non-feeding of the recording material may be used, such as a method of judging based on the travel distance of the transport roller from the start of feeding of the recording material until it is detected by the registration sensor 27.

[0022] [Configuration of the recording material transport mechanism] 2 is a diagram showing the configuration of hardware related to the recording material feeding mechanism of the printer PR of this embodiment. The configuration diagram of FIG. 2 is composed of a host computer 201, which is an external device that requests printing to the printer PR, a video controller 202 and an engine control unit 203 that the printer PR has, and hardware related to the recording material feeding mechanism. The video controller 202 receives print data and print instructions sent from the host computer 201 and sends them to the engine control unit 203. The engine control unit 203 is a control IC, and has a CPU 511 that executes various control operations inside, a RAM 512 that temporarily stores data necessary for the operation of the printer PR, and a ROM 513 that stores programs and control tables necessary for the operation of the printer PR. The engine control unit 203 also has a system timer 514 that generates timing and measures time required for various controls, a communication unit 510 that performs communication processing with the video controller 202, and an I / O port 516 that inputs and outputs control signals to various units. In the engine control unit 203 , the communication unit 510 , CPU 511 , RAM 512 , ROM 513 , system timer 514 , and I / O port 516 are connected via a system bus 515 .

[0023] Also, a registration sensor input circuit 520, a paper feed motor drive circuit 521, a paper feed solenoid drive circuit 522, and a paper feed tray recording material presence / absence sensor input circuit 523 are connected to the I / O port 516 of the engine control unit 203. Furthermore, a paper feed solenoid drive circuit 524 and a paper feed cassette presence / absence sensor input circuit 525 are connected to the I / O port 516 of the engine control unit 203. The registration sensor input circuit 520 receives a detection signal indicating that the recording material 26 or the recording material 56 is detected from the registration sensor 27, and outputs the detection signal to the CPU 511 via the I / O port 516. The paper feed motor drive circuit 521 receives a control signal from the CPU 511, and drives and stops the paper feed motor 204 in response to the control signal. The paper feed solenoid drive circuit 522 receives a control signal from the CPU 511, and drives and stops the paper feed solenoid 205 of the manual feed mechanism 50 in response to the control signal. A detection signal from the paper feed tray recording material presence sensor 55 of the manual feed mechanism 50 is input to the paper feed tray recording material presence sensor input circuit 523, and outputs the detection signal to the CPU 511 via the I / O port 516. The paper feed solenoid drive circuit 524 receives a control signal from the CPU 511, and drives or stops the paper feed solenoid 206 of the cassette feed mechanism 20 in response to the control signal. The paper feed cassette presence sensor input circuit 525 receives a signal from the paper feed cassette presence sensor 207, and outputs a detection signal to the CPU 511 via the I / O port 516. It should be noted that the devices connected to the engine control unit 203 via the I / O port 516 are not limited to the units shown in FIG. 2.

[0024] [Function block for controlling recording material transport] Next, the function of the engine control unit 203 regarding the recording material feeding control will be described. FIG. 3 is a block diagram for explaining the relationship between the functional blocks of the engine control unit 203 regarding the recording material feeding control and the above-mentioned recording material feeding mechanism. The recording material feeding control function of the engine control unit 203 is realized by the CPU 511 executing a program stored in the ROM 513 based on data stored in the RAM 512. The engine control unit 203 has, as functions regarding the recording material feeding control, a recording material feeding function, a non-feed detection function, a recording material feeding retry count (retransmission count) memory function for eliminating the non-feed, and a recording material feeding retry control function. As shown in FIG. 3, the engine control unit 203 has functional blocks of a feeding unit 310, a driving unit 311, a recording material detection unit 312, a non-feed detection unit 313, a feeding retry unit 314, a recording material presence / absence detection unit 315, and a feeding retry memory unit 316 in order to perform the above-mentioned control functions. The functions of each functional block are realized by the CPU 511 of the engine control unit 203 executing a program stored in the ROM 513. The control functions of each functional block will be described below in order.

[0025] (Feed control) The engine control unit 203 has a feeding unit 310 and a driving unit 311 to perform a feeding control function. When the engine control unit 203 receives a print instruction from the video controller 202, the feeding unit 310 instructs the driving unit 311 to feed the recording material. Furthermore, the feeding unit 310 resets and starts a system timer 514 to detect whether the fed recording material reaches the registration sensor 27 within a predetermined specified time. The driving unit 311 drives the paper feed motor 204 via a paper feed motor driving circuit 521 according to an instruction from the feeding unit 310. When the paper feed motor 204 is driven, the conveying roller 23 and the separation roller 24 of the cassette feeding mechanism 20, the conveying roller 53 and the separation roller 54 of the manual feeding mechanism 50, and the registration roller pair 25 rotate. Furthermore, when the recording material 26 is fed from the paper feed cassette 21 of the cassette feeding mechanism 20, the drive unit 311 rotates the feed roller 22 once by driving the paper feed solenoid 206 via the paper feed solenoid drive circuit 524 at the timing of starting feeding. By this operation, the recording material 26 placed on the paper feed cassette 21 is separated and fed one by one, and conveyed to the registration roller pair 25 and the registration sensor 27. On the other hand, when the recording material 56 on the paper feed tray 51 of the manual feed mechanism 50 is fed, the drive unit 311 rotates the feed roller 52 once by driving the paper feed solenoid 205 via the paper feed solenoid drive circuit 522 at the timing of starting feeding. By this operation, the recording material 56 on the paper feed tray 51 is separated and fed one by one, and conveyed to the registration roller pair 25 and the registration sensor 27.

[0026] (Detection of non-delivery) The engine control unit 203 has a recording material detection unit 312 and a non-feed detection unit 313 for detecting non-feeding. The recording material detection unit 312 receives a detection result of the recording material conveyed on the conveying path from the registration sensor 27 via a registration sensor input circuit 520. The recording material detection unit 312 detects whether the recording material 26 in the paper feed cassette 21 or the recording material 56 on the paper feed tray 51 has reached the registration sensor 27 after feeding the recording material based on the detection result from the registration sensor 27. When the recording material detection unit 312 receives a detection signal indicating that the recording material has been detected from the registration sensor 27, it notifies the non-feed detection unit 313. The non-feed detection unit 313 monitors the reception of a recording material detection signal of the registration sensor 27 from the recording material detection unit 312 within a predetermined specified time after the recording material is fed, while checking the elapsed time measured by the above-mentioned system timer 514 after the recording material is fed. The non-feed detection unit 313 determines that the recording material has been normally conveyed if it receives a detection signal from the recording material detection unit 312 within a specified time that detects the arrival of the recording material. On the other hand, if the non-feed detection unit 313 does not receive a detection signal from the recording material detection unit 312 within a predetermined specified time, it determines that a non-feed has occurred, and notifies a feeding retry unit 314 (described later) that a non-feed has occurred.

[0027] (Memory of number of retry attempts) The engine control unit 203 has a recording material presence / absence detection unit 315 and a feeding retry storage unit 316 for storing the number of feeding retries for re-feeding the recording material to resolve the non-feed. The feeding retry storage unit 316 updates the number of feeding retries when notified of the implementation of a feeding retry from a feeding retry unit 314, which will be described later. The number of feeding retries is updated for each paper feed tray, that is, for each paper feed cassette 21 or paper feed tray 51 that is the feeding source of the recording material where the non-feed occurred. The recording material presence / absence detection unit 315 detects whether the recording material 56 is placed on the paper feed tray 51 by the paper feed tray recording material presence / absence sensor 55 of the manual feed mechanism 50 via a paper feed tray recording material presence / absence sensor input circuit 523. Furthermore, the recording material presence / absence detection unit 315 detects the attachment / detachment state of the paper feed cassette 21 to the printer PR by the paper feed cassette presence / absence sensor 207 of the cassette feeding mechanism 20 via the paper feed cassette presence / absence sensor input circuit 525. When the recording material presence / absence detection unit 315 detects a change in state due to the recording material 56 being exhausted on the paper feed tray 51 or the paper feed cassette 21 being attached / detached, it notifies the feeding retry storage unit 316. When the feeding retry storage unit 316 is notified by the recording material presence / absence detection unit 315 that the recording material 56 being exhausted on the paper feed tray 51, it resets the number of feeding retries for the paper feed tray 51. When the feeding retry storage unit 316 is notified by the recording material presence / absence detection unit 315 that the paper feed cassette 21 has been attached / detached, it resets the number of feeding retries for the paper feed cassette 21.

[0028] (Feed retry control) The engine control unit 203 has a feeding retry unit 314 for controlling feeding retry. When the feeding retry unit 314 is notified of the occurrence of non-feeding from the non-feed detection unit 313, it acquires the number of feeding retries of the paper feed cassette 21 or paper feed tray 51 in which the non-feeding occurred from the feeding retry storage unit 316. Then, the feeding retry unit 314 judges whether to perform a feeding retry based on the acquired number of non-feeding occurrences. The feeding retry judgment conditions of the feeding retry unit 314 in this embodiment will be described later. Furthermore, when it is judged that a feeding retry is to be performed, the feeding retry unit 314 executes a cleaning operation to remove the toner images formed on the photosensitive drum 1 and the intermediate transfer belt 11. In the cleaning operation of the photosensitive drum 1, the toner image formed on the photosensitive drum 1 is scraped off by a drum cleaning blade, and the scraped off toner is collected in the waste toner container 7. Similarly, in the cleaning operation of the intermediate transfer belt 11, the toner image formed on the intermediate transfer belt 11 is scraped off by the cleaning blade 16a, and the scraped off toner is collected in the waste toner container 16b. When the cleaning operation is completed, the feeding retry unit 314 again issues a feeding instruction to the feeding unit 310, thereby performing a feeding retry.

[0029] In the above-mentioned cleaning operation, the photosensitive drum 1 and the intermediate transfer belt 11, etc., need to be driven in order to remove the toner image and collect it in the waste toner container 7, etc. The process cartridge 5 and the intermediate transfer belt 11, which are consumables that are replaced when they reach the end of their life, are driven, and thus their lifespans are shortened. Therefore, if non-feeding occurs frequently and a feed retry is performed each time, the cleaning operation will shorten the lifespans of the consumables, such as the process cartridge 5 and the intermediate transfer belt 11. Possible causes of non-feeding include the use of recording material with a large amount of paper dust attached to its surface, which is called poor quality paper, and the recording material in the paper feed tray 51 or the paper feed cassette 21 being placed at a position that is shifted from the specified position at which it should be set. In order to prevent non-feeding from occurring, it is necessary to improve the recording material or the loading state of the recording material in the feed mechanism, such as by replacing the poor quality paper with a good quality recording material or by placing the recording material correctly at the specified position. Therefore, the feeding retry memory unit 316 does not reset the number of feeding retries until it detects that the recording material 56 on the paper feed tray 51 has run out or that the paper feed cassette 21 has been removed or replaced, and that measures have been taken to eliminate the cause of the non-feeding.

[0030] [Recording material feed control sequence] FIG. 4 is a flowchart showing a control sequence of the recording material feeding control of this embodiment. As described above, in the printer PR, when the video controller 202 receives a print request from the host computer 201, it instructs the engine control unit 203 to print. When the engine control unit 203 receives a print instruction from the video controller 202, it starts an image forming operation. The process of FIG. 4 is started every time the engine control unit 203 feeds the recording material 26 from the paper feed cassette 21 or the recording material 56 from the paper feed tray 51 when performing the image forming operation, and is executed by each control unit of the engine control unit 203 shown in FIG. 3 described above. Note that the control sequence shown in FIG. 4 is a control sequence for the feeding control of the recording material, that is, the detection of the occurrence or non-feeding of the recording material and the feeding retry, and the control sequence for the image forming control executed in association with the feeding of the recording material is omitted. Also, it is assumed that the number of feeding retries x stored in the feeding retry storage unit 316 described later is reset when the printer PR is turned on.

[0031] In step (hereinafter, referred to as S) 101, the feeding section 310 of the engine control section 203 instructs the driving section 311 to perform a paper feeding operation, and starts feeding the recording material. The driving section 311 drives the paper feed motor 204 via the paper feed motor driving circuit 521 in accordance with the instruction from the feeding section 310. Then, the driving section 311 feeds the recording material 26 from the paper feed cassette 21 of the cassette feeding mechanism 20, or the recording material 56 from the paper feed tray 51 of the manual feed mechanism 50, based on the instruction from the feeding section 310. The fed recording material 26 or recording material 56 is transported to the registration roller pair 25 and the registration sensor 27.

[0032] In S102, the non-feed detection unit 313 judges whether or not a notification that the registration sensor 27 has detected the fed recording material has been received from the recording material detection unit 312 within a predetermined specified time. If the non-feed detection unit 313 receives a notification from the recording material detection unit 312 within the specified time that the registration sensor 27 has detected the fed recording material, the non-feed detection unit 313 judges that the feeding of the recording material has been performed normally, and ends the process. Thereafter, the engine control unit 203 continues the image forming operation on the fed recording material. On the other hand, if the non-feed detection unit 313 does not receive a notification from the recording material detection unit 312 within the specified time that the registration sensor 27 has detected the recording material, the non-feed detection unit 313 judges that a non-feed has occurred, notifies the feeding retry unit 314 of the occurrence of the non-feed, and proceeds to S103.

[0033] In S103, the feeding retry unit 314 judges whether the recording material for which no feeding has occurred is a recording material for which a feeding retry has occurred. The reason for judging whether the recording material is a recording material for which a feeding retry has occurred is that if the recording material cannot be fed normally even after one feeding retry has been performed, there is a high possibility that the recording material cannot be fed normally even if a feeding retry is performed again. For this reason, in this embodiment, the feeding retry is performed once. If the feeding retry unit 314 judges that the recording material for which no feeding has occurred is a recording material for which a feeding retry has been performed, the process proceeds to S104, and if the feeding retry unit 314 judges that the recording material for which no feeding has occurred is not a recording material for which a feeding retry has been performed, the process proceeds to S108.

[0034] In S104, the feeding retry unit 314 displays on the operation display unit (not shown) to inform the user that a non-feed has occurred. Furthermore, when a non-feed occurs with the recording material 26 fed from the cassette feeding mechanism 20, the feeding retry unit 314 displays on the operation display unit (not shown) instructions to prompt the user to check whether the recording material 26 in the paper feed cassette 21 is correctly placed in a predetermined position. Furthermore, when a non-feed occurs with the recording material 56 fed from the feeding mechanism 50, the feeding retry unit 314 displays on the operation display unit (not shown) instructions to prompt the user to check whether the recording material 56 on the paper feed tray 51 is correctly placed in a predetermined position.

[0035] In S105, the recording material presence / absence detection unit 315 determines whether the user has confirmed the state of the recording material 26 in the paper feed cassette 21 or the recording material 56 on the paper feed tray 51 in accordance with the instruction displayed on the operation display unit (not shown) in the process of S104. In detail, in this embodiment, the recording material presence / absence detection unit 315 detects that the paper feed cassette 21 has been pulled out from the printer PR using the paper feed cassette presence / absence sensor 207. Thereafter, the recording material presence / absence detection unit 315 determines that the state of the recording material 26 in the paper feed cassette 21 has been confirmed by the paper feed cassette presence / absence sensor 207 detecting that the paper feed cassette 21 is mounted on the printer PR. Meanwhile, with regard to the recording material 56 on the paper feed tray 51, the recording material presence / absence detection unit 315 detects that the paper feed tray recording material presence / absence sensor 55 detects that there is no recording material on the paper feed tray 51, and then detects that a recording material has been placed on the paper feed tray 51. In this case, recording material presence / absence detection unit 315 determines that the user has confirmed the state of recording material 56 on paper feed tray 51. If recording material presence / absence detection unit 315 determines that the state of recording material 26 in paper feed cassette 21 or recording material 56 on paper feed tray 51 has been confirmed, it notifies feed retry unit 314 and feed retry memory unit 316 to that effect, and proceeds to process S106. On the other hand, if recording material presence / absence detection unit 315 determines that the state of recording material 26 in paper feed cassette 21 or recording material 56 on paper feed tray 51 has not been confirmed, it returns the process to S105.

[0036] In S106, when the feeding retry memory unit 316 is notified by the recording material presence / absence detection unit 315 that the placement state of the recording material 56 on the paper feed tray 51 has been confirmed, the feeding retry memory unit 316 resets the number of feeding retries x for the paper feed tray 51 (x=0). Also, when the feeding retry memory unit 316 is notified by the recording material presence / absence detection unit 315 that the paper feed cassette 21 has been attached or detached, the feeding retry memory unit 316 resets the number of feeding retries x for the paper feed cassette 21 (x=0).

[0037] In S107, the feeding retry unit 314 executes a recovery process such as a cleaning operation to remove the toner images formed on the photosensitive drum 1 and the intermediate transfer belt 11. Then, when the recovery process ends, the feeding retry unit 314 returns the process to S101 to execute a retry of feeding the recording material.

[0038] In S108, the feeding retry unit 314 acquires the number of feeding retries x from the feeding retry memory unit 316, and determines whether the acquired number of feeding retries x is greater than a threshold A, which is a predetermined threshold value for the number of feeding retries. If the feeding retry unit 314 determines that the number of feeding retries x is greater than the threshold A, the process proceeds to S104, and if the feeding retry unit 314 determines that the number of feeding retries x is equal to or less than the threshold A (less than the threshold), the process proceeds to S109.

[0039] In S109, the feeding retry unit 314 instructs the feeding retry storage unit 316 to update the feeding retry count x. If the recording material for which no feeding has occurred is the recording material 26 fed from the paper feed cassette 21, the feeding retry storage unit 316 updates the feeding retry count x corresponding to the paper feed cassette 21 (x=x+1). On the other hand, if the recording material for which no feeding has occurred is the recording material 56 fed from the paper feed tray 51, the feeding retry storage unit 316 updates the feeding retry count x corresponding to the paper feed tray 51 (x=x+1). Then, the process proceeds to S107 to retry feeding the recording material.

[0040] In this embodiment, threshold A, which is the threshold for the number of feeding retries, is predefined for each paper feed tray, with threshold A being 20 for recording material 26 in paper feed cassette 21 and threshold A being 10 for recording material 56 in paper feed tray 51. The value of threshold A is defined based on the expected number of feeding retries when, for example, the maximum number of recording materials, known as poor quality paper, with a large amount of paper dust adhering to the surface, are loaded in the paper feed tray of each feeding mechanism and all of them are fed. This makes it possible to prevent the life of consumables such as cartridges, which are replacement parts, from being shortened by the cleaning operation even if more feeding retries than expected occur.

[0041] As described above, in this embodiment, before a retry of feeding the recording material is performed, it is determined whether or not to perform a retry of feeding based on the number of retry attempts. This makes it possible to reduce non-feeding due to the retry control while suppressing the shortening of the life of consumables such as the process cartridge 5.

[0042] In this embodiment, the feeding retry unit 314 judges whether or not to perform a feeding retry based on the number of feeding retries when a non-feed is detected by the non-feed detection unit 313 and the feeding retry storage unit 316, but this is not limited to the above. For example, the feeding retry storage unit 316 does not reset the number of feeding retries even if the recording material presence / absence detection unit 315 checks the state of the recording material (even if it detects that the recording material has run out). Then, the feeding retry unit 314 judges whether non-feeding occurs frequently based on the ratio between the most recent predetermined number of feedings in which the feeding unit 310 fed the recording material and the number of occurrences of non-feeding detected by the non-feed detection unit 313. Then, it may be arranged to judge whether or not to perform a feeding retry depending on the frequency of occurrence of non-feeding. Also, in this embodiment, the no-feed detection unit 313 stores the number of times no-feeding has occurred for each paper feed tray, but it may also be possible to store the number of no-feeding occurrences collectively regardless of the paper feed tray, and determine whether or not to perform a feed retry based on the number of feed retries in the printer PR.

[0043] As described above, according to this embodiment, it is possible to reduce non-feeding while suppressing the shortening of the life span of consumables. EXAMPLES

[0044] In the first embodiment, the threshold value for determining whether or not to perform a feed retry based on the number of feed retries was a fixed value. In the second embodiment, an embodiment will be described in which the threshold value for determining whether or not to perform a feed retry based on the number of feed retries is changed according to the remaining life of a consumable such as a process cartridge. Note that the image forming apparatus to which this embodiment is applied is similar to the printer PR in the first embodiment, and the same reference numerals are used for the same configurations, and the description here will be omitted.

[0045] [Configuration of the recording material transport mechanism] Fig. 5 is a diagram showing the configuration of hardware related to the recording material feeding mechanism of the printer PR of this embodiment. Fig. 5 differs from Fig. 2 of the first embodiment in that a main motor drive circuit 526 and a main motor 208 (drive unit) are added, but the other configurations are the same as those of Fig. 2, and therefore a description thereof will be omitted here. The main motor drive circuit 526 receives a control signal from the CPU 511 of the engine control unit 203, and drives or stops the main motor 208 in response to the received control signal. When the main motor 208 is driven, the photosensitive drum 1, charging roller 2, and developing roller 3 of each process cartridge 5 are driven to rotate.

[0046] [Function block for controlling recording material transport] 6 is a block diagram for explaining the relationship between the functional blocks of the engine control unit 203 related to the feeding control of the recording material and the above-mentioned feeding mechanism of the recording material. FIG. 6 is different from FIG. 3 of the first embodiment in that a life detection unit 317 is added as a function related to life detection, but the other functional blocks are the same as those of FIG. 3, and therefore the description here is omitted. The life detection unit 317 detects the remaining life of each process cartridge 5 based on the driving time of the main motor 208. In this embodiment, the remaining life of the process cartridge 5 is detected based on the driving time of the main motor 208, but other methods may be used, such as detecting the remaining life of the process cartridge 5 based on the travel distance of the photosensitive drum 1.

[0047] [Recording material feed control sequence] Fig. 7 is a flow chart showing a control sequence of the recording material feeding control of this embodiment. The process of Fig. 7 is started every time the recording material 26 is fed from the paper feed cassette 21 or the recording material 56 is fed from the paper feed tray 51, and is executed by each control unit of the engine control unit 203 shown in Fig. 6 described above. Note that the control sequence shown in Fig. 7 is a control sequence for the feeding control of the recording material, that is, the detection of the occurrence or non-feeding of the recording material and the feeding retry, and the control sequence for the image formation control executed in association with the feeding of the recording material is omitted. Also, the number of feeding retries x stored in the feeding retry storage unit 316 described later is reset when the printer PR is turned on.

[0048] 7 are the same as the processes of S101 to S107 and S109 shown in Fig. 4 of the first embodiment, and therefore will not be described here. In S103, the feeding retry unit 314 judges whether the recording material for which no feeding has occurred is a recording material for which a feeding retry has occurred, and if it is not a recording material for which a feeding retry has occurred, the process proceeds to S110, and if it is a recording material for which a feeding retry has occurred, the process proceeds to S104.

[0049] In S110, the feeding retry unit 314 acquires the number of feeding retries x from the feeding retry memory unit 316, and acquires threshold value B, which is a threshold value for the number of feeding retries based on the driving time of the main motor 208, from the life detection unit 317. The feeding retry unit 314 then determines whether the acquired number of feeding retries x is greater than threshold value B, which is a threshold value for the number of feeding retries. If the feeding retry unit 314 determines that the number of feeding retries x is greater than threshold value B, it advances the process to S104, and if it determines that the number of feeding retries x is equal to or less than threshold value B, it advances the process to S109.

[0050] In this embodiment, the threshold value B of the number of feeding retries is set by the life detection unit 317 according to the remaining life of each process cartridge 5. In this embodiment, the life detection unit 317 sets the threshold value B of the number of feeding retries according to the remaining life of the process cartridge 5 in Table 1 shown below. Table 1 is a table showing the threshold value of the number of feeding retries according to the remaining life of the process cartridge 5. Table 1 is composed of an item showing the remaining life of the process cartridge 5 and an item showing the threshold value B of the number of feeding retries corresponding to the remaining life. In Table 1, the values ​​of the threshold value B when the remaining life of the process cartridge 5 is 30% or more, 10% or more and less than 30%, and less than 10% are 20 times, 10 times, and 5 times, respectively. Note that the life detection unit 317 determines the threshold value B of the life of the process cartridge 5 based on the minimum remaining life among the remaining lives of the process cartridges 5 of four colors. [Table 1]

[0051] As shown in Table 1, the feeding retry unit 314 in this embodiment sets the threshold value B of the number of feeding retries to be smaller as the remaining life of the process cartridge 5 becomes shorter. If a non-feed occurs after the formation of a toner image has started in the process cartridge 5, a recovery process is executed to clean the toner image that has already been formed, which further reduces the life of the process cartridge 5. Therefore, when the remaining life of the process cartridge 5 becomes shorter, the number of feeding retries is reduced to prevent the process cartridge 5 from having to be replaced with a new one earlier. Note that in this embodiment, the threshold value of the number of feeding retries is set in table format as shown in Table 1, but the threshold value may be calculated, for example, by a formula.

[0052] As described above, in this embodiment, the feeding retry unit 314 judges whether to perform a feeding retry based on the number of feeding retries and the remaining life of the process cartridge 5 by the non-feed detection unit 313, the feeding retry storage unit 316, and the life detection unit 317. This makes it possible to reduce non-feeding by feeding retry control while preventing the process cartridge 5 from being replaced earlier. In this embodiment, the life detection of the process cartridge 5 is performed based on the driving time of the main motor. For example, the intermediate transfer belt 11 also needs to perform a recovery process for cleaning the toner image on the intermediate transfer belt 11 when retrying feeding. Therefore, if the life of parts consumed in the recovery process for feeding retry can be detected for the intermediate transfer belt 11, this embodiment can be applied in the same way as the process cartridge 5.

[0053] As described above, according to this embodiment, it is possible to reduce non-feeding while suppressing the shortening of the life span of consumables. EXAMPLES

[0054] The threshold value for determining whether or not to perform a feed retry based on the number of feed retries is a fixed value in the first embodiment, and is the remaining life of a consumable such as a process cartridge in the second embodiment. In the third embodiment, an embodiment will be described in which the threshold value for determining whether or not to perform a feed retry based on the number of feed retries is changed according to the amount of recording material loaded on the paper feed tray. Note that the image forming apparatus to which this embodiment is applied is similar to the printer PR in the first and second embodiments, and the same reference numerals are used for the same components, and the description here will be omitted.

[0055] [Configuration of the recording material transport mechanism] Fig. 8 is a diagram showing the configuration of hardware related to the recording material feeding mechanism of the printer PR of this embodiment. Fig. 8 differs from Fig. 2 of the first embodiment in that a lift-up motor drive circuit 527, a lift-up motor 209, a paper surface sensor input circuit 528, and a paper surface sensor 28 are added, but the other configurations are the same as those of Fig. 2, and their explanations are omitted here. A signal from a paper surface sensor 28 that detects the uppermost recording material 26 placed on the paper feed tray of the paper feed cassette 21 is input to the paper surface sensor input circuit 528, and is output to the CPU 511 of the engine control unit 203 via the I / O port 516. When the paper surface sensor 28 detects the uppermost recording material 26 placed on the paper feed tray of the paper feed cassette 21, it outputs a detection signal to the CPU 511 via the paper surface sensor input circuit 528.

[0056] Further, the lift-up motor drive circuit 527 receives a control signal from the CPU 511 of the engine control unit 203, and drives or stops the lift-up motor 209 in response to the input control signal. When the CPU 511 feeds the recording material 26 from the paper feed cassette 21, it outputs a control signal to the lift-up motor drive circuit 527 to instruct the lift-up motor 209 to be driven. This drives the lift-up motor 209, and the topmost recording material 26 placed on the paper feed tray 29 (the bottom plate of the paper feed cassette 21) in the paper feed cassette 21 comes into contact with the feed roller 22. In detail, by driving the lift-up motor 209, the paper feed tray of the paper feed cassette 21 is lifted toward the feed roller 22, and the topmost recording material 26 placed on the paper feed tray moves to a position where it comes into contact with the feed roller 22. When the topmost recording material 26 of the paper feed tray moves to a position where it abuts against the feed roller 22, the paper surface sensor 28 detects the topmost recording material 26 and outputs a detection signal to the CPU 511. When the CPU 511 receives the detection signal from the paper surface sensor 28, it determines that the topmost recording material 26 of the paper feed tray abuts against the feed roller 22 and has moved to a position where it can be fed. Then, the CPU 511 outputs a control signal to the lift-up motor drive circuit 527 to stop driving the lift-up motor 209, thereby stopping the driving of the lift-up motor 209.

[0057] [Function block for controlling recording material transport] FIG. 9 is a block diagram for explaining the relationship between the functional blocks of the engine control unit 203 related to the feeding control of the recording material and the above-mentioned feeding mechanism of the recording material. FIG. 9 is different from FIG. 3 of the first embodiment in that a recording material amount detection unit 318 is added as a function related to the detection of the loading amount of the recording material. However, the other functional blocks are the same as those of FIG. 3, and the description here will be omitted. The recording material amount detection unit 318 detects the loading amount of the recording material 26 loaded in the paper feed cassette 21 based on the driving time from when the lift-up motor 209 is driven until the paper surface sensor 28 detects the recording material 26 placed at the top of the paper feed tray of the paper feed cassette 21. In this embodiment, the loading amount of the recording material 26 in the paper feed cassette 21 is calculated based on the driving time of the lift-up motor 209. If the loading amount of the recording material 26 in the paper feed cassette 21 can be detected, it may be calculated using another method, such as detecting the pushing-up amount of the paper feed tray 29 with another sensor.

[0058] [Recording material feed control sequence] FIG. 10 is a flowchart showing a control sequence of the recording material feeding control of this embodiment. The process of FIG. 10 is started every time the recording material 26 is fed from the paper feed cassette 21, and is executed by each control unit of the engine control unit 203 shown in FIG. 9 described above. Note that this embodiment is an embodiment of a feeding retry based on a threshold value according to the loading amount of the recording material 26 placed on the paper feed tray 29 of the paper feed cassette 21 detected by the paper surface sensor 28. Therefore, the flowchart of FIG. 10 is applied when the recording material 26 is fed from the paper feed cassette 21, and is not applied when the recording material 56 is fed from the paper feed tray 51. Note that the control sequence shown in FIG. 7 is a control sequence for the feeding control of the recording material, that is, the detection of the occurrence or absence of non-feeding of the recording material, and the feeding retry, and the control sequence of the image formation control executed in association with the feeding of the recording material is omitted. Also, it is assumed that the number of feeding retries x stored in the feeding retry storage unit 316 described later is reset when the printer PR is turned on.

[0059] The processes of S101 to S107 and S109 shown in Fig. 10 are the same as the processes of S101 to S107 and S109 shown in Fig. 4 of the first embodiment, respectively, and therefore will not be described here. In S103, the feeding retry unit 314 judges whether the recording material for which no feeding has occurred is a recording material for which a feeding retry has occurred, and if it is not a recording material for which a feeding retry has occurred, the process proceeds to S110, and if it is a recording material for which a feeding retry has occurred, the process proceeds to S104.

[0060] In S111, the feeding retry unit 314 acquires the number of feeding retries x from the feeding retry memory unit 316, and acquires the threshold value C, which is a threshold value for the number of feeding retries, based on the amount of recording material 26 loaded in the paper feed cassette 21, from the recording material amount detection unit 318. The feeding retry unit 314 then determines whether the acquired number of feeding retries x is greater than the threshold value C, which is a threshold value for the number of feeding retries. If the feeding retry unit 314 determines that the number of feeding retries x is greater than the threshold value C, it proceeds to S104, and if it determines that the number of feeding retries x is equal to or less than the threshold value C, it proceeds to S109.

[0061] In this embodiment, the threshold C of the number of feeding retries is set by the recording material amount detection unit 318 according to the amount of recording material 26 loaded on the paper feed tray of the paper feed cassette 21. In this embodiment, the recording material amount detection unit 318 determines the threshold C of the number of feeding retries according to the amount of recording material 26 loaded on the paper feed tray 29 in Table 2 shown below. Table 2 is a table showing the thresholds of the number of feeding retries according to the amount of recording material 26 loaded. Table 2 is made up of an item showing the amount of recording material 26 loaded on the paper feed tray of the paper feed cassette 21 and an item showing the threshold C of the number of feeding retries corresponding to the amount of recording material loaded. Note that in this embodiment, the recording material amount detection unit 318 has a table that associates the driving time of the lift-up motor 209 with the amount of recording material 26 loaded on the paper feed tray 29. Then, the recording material amount detection unit 318 calculates the amount of recording material 26 placed on the paper feed tray 29 based on the driving time of the lift-up motor 209 and the detection signal from the paper surface sensor 28. In Table 2, the values ​​of threshold C when the recording material load amount on the paper feed tray 29 is 67% or more of the maximum load amount of the paper feed cassette 21, 34% or more but less than 67%, and less than 34% of the maximum load amount are 20, 13, and 6, respectively. [Table 2]

[0062] As shown in Table 2, the feeding retry unit 314 in this embodiment sets the threshold C of the number of feeding retries to be smaller as the remaining amount of recording material 26 placed on the paper feed tray 29 decreases. In this way, in this embodiment, it is possible to set the expected number of feeding retries according to the number of sheets of recording material with a large amount of paper dust attached to the surface, called poor quality paper. As a result, even if a user sets a small number of recording materials in the paper feed cassette 21, it is possible to determine whether or not feeding retries are occurring more frequently than expected. Note that in this embodiment, as in Table 2, the unit of the amount of recording material 26 placed on the paper feed tray 29 is "%", but the "number of sheets" of the recording material 26 may be used as the unit of the amount of loading. Also, in this embodiment, as in Table 2, the threshold of the number of feeding retries is set in a table format, but the threshold may be calculated, for example, by a formula.

[0063] As described above, in this embodiment, the feed retry unit 314 determines whether to perform a feed retry based on the number of feed retries and the amount of loaded recording material 26, using the no-feed detection unit 313, the feed retry memory unit 316, and the recording material amount detection unit 318. This makes it possible to reduce no-feeds due to feed retry control while suppressing shortening of the life span of consumables such as cartridges, even when the user sets a small number of recording materials 26 in the paper feed cassette 21.

[0064] As described above, according to this embodiment, it is possible to reduce non-feeding while suppressing the shortening of the life span of consumables. [Explanation of symbols]

[0065] 5 Process cartridge 21 Paper feed cassette 22 Feeding roller 27 Resist sensor 51 Paper feed tray 52 Feeding roller 230 Engine control unit

Claims

1. A recording medium recording device comprising: a removable first loading section; and a second loading section on which a recording material can be manually loaded, the loading section on which the recording material is loaded; a feeding means for feeding the recording material loaded on the loading section to a conveying path; an image forming means for forming an image on a recording material; a detection means for detecting a non-feed state in which the recording material is not fed from the stacking portion; A control means for controlling the feeding of the recording material; Equipped with when the detection means detects the non-feed, the control means determines whether or not to re-feed the recording material based on the number of re-feeds of the recording material and any one of a predetermined threshold, a threshold based on the remaining life of the image forming means, and a threshold based on the amount of recording material stacked on the stacking section; The image forming apparatus according to claim 1, wherein the predetermined threshold value is determined in accordance with the number of sheets of recording material that can be placed on the first stacking unit and the second stacking unit.

2. 2. The image forming apparatus according to claim 1, wherein the detection means has a detection unit disposed in a transport path between the stacking section and the image forming means, which detects the recording material being transported, and when the detection unit does not detect the recording material within a predetermined time after the recording material is fed from the stacking section, it determines that the non-feeding has occurred.

3. The image forming apparatus described in Claim 2, characterized in that the image forming means has a plurality of image forming units each having a photosensitive drum on which an electrostatic latent image is formed, and a developing unit which adheres toner to the electrostatic latent image formed on the photosensitive drum to form a toner image.

4. The image forming apparatus according to claim 3, characterized in that the control means does not resend the recording material when the number of resends is greater than the predetermined threshold value determined for the first stacking section or the second stacking section to which the recording material in the non-feeding event was fed, and resends the recording material when the number of resends is equal to or less than the predetermined threshold value determined for the first stacking section or the second stacking section to which the recording material in the non-feeding event was fed.

5. a life detection means for detecting a remaining life of the image forming means; A drive unit that drives the image forming means; Equipped with The image forming apparatus according to claim 3, characterized in that the life detection means calculates the remaining life of each of the image forming units based on the driving time of each of the image forming units driven by the driving unit, and determines the threshold value of the number of retransmissions based on the shortest remaining life among the calculated remaining lives of each of the image forming units.

6. The image forming apparatus according to claim 5, characterized in that the control means does not resend the recording material when the number of resends is greater than a threshold based on the remaining life of the image forming means detected by the life detection means, and resends the recording material when the number of resends is equal to or less than the threshold based on the remaining life of the image forming means detected by the life detection means.

7. a recording material amount detection unit for detecting an amount of recording material stacked on the first stacking unit, 4. The image forming apparatus according to claim 3, wherein the recording material amount detection means has a position detection unit that detects the position of the topmost recording material stacked on the first stacking unit, detects the amount of recording material stacked on the first stacking unit based on the position of the topmost recording material detected by the position detection unit, and determines the threshold value of the number of retransmissions based on the detected amount of recording material.

8. 8. The image forming apparatus according to claim 7, wherein the control means does not resend the recording material when the number of resends is greater than a threshold based on the amount of recording material stacked in the stacking section detected by the recording material amount detection means, and resends the recording material when the number of resends is equal to or less than a threshold based on the amount of recording material stacked in the stacking section detected by the recording material amount detection means.

9. the image forming means includes an intermediate transfer belt onto which a toner image formed on the photosensitive drum of each of the image forming units is transferred; a cleaning unit for removing the toner on each of the photosensitive drums and the toner on the intermediate transfer belt; 9. The image forming apparatus according to claim 4, wherein the control unit controls the cleaning unit to clean the photosensitive drum and the intermediate transfer belt before re-transmitting the recording material.

10. 10. The image forming apparatus according to claim 9, wherein the control unit retransmits the recording material once.

11. 11. The image forming apparatus according to claim 10, wherein the control means notifies the occurrence of the non-feed when the non-feed is detected during re-feeding of the recording material.

12. A display unit for displaying information is provided, 12. The image forming apparatus according to claim 11, wherein the control unit displays on the display unit a message indicating the occurrence of the non-feed and a message prompting a user to confirm a state of the stacking unit on which the recording material in the non-feed state is placed.

13. The image forming apparatus according to claim 12, wherein the control means resets the number of retransmissions corresponding to the stacking section when it detects that a check has been made on the state of the stacking section on which the recording material in the non-feeding state is placed.

14. a state detection means for detecting an attachment / detachment state of the first loading section, 14. The image forming apparatus according to claim 13, wherein the control unit determines that the state of the first stacking unit has been confirmed when the state detection unit detects a change in the attachment / detachment state of the first stacking unit.

15. a recording material detection unit that detects the presence or absence of a recording material placed on the second stacking unit, The image forming apparatus according to claim 13, wherein the control means determines that the state of the recording material placed on the second stacking section has been confirmed when the recording material detection means detects a change in the presence or absence of the recording material.

Images