JP7327021B2 - IMAGE FORMING APPARATUS, IMAGE FORMING APPARATUS CONTROL METHOD AND PROGRAM - Google Patents

Description

The present invention relates to an image forming apparatus, an image forming apparatus control method, and a program.

2. Description of the Related Art Conventionally, there is an image forming apparatus configured to stop a sheet between a sheet feeding section and an image transfer section. In such an image forming apparatus, even if it is judged that the paper cannot be transferred in time for the transfer of the drawn image, it is not judged as a paper jam. A retry function (hereinafter referred to as an "image resend function") is known that can restart the transport by doing so.

Japanese Patent Application Laid-Open No. 2002-200002 detects the sheet interval based on the output of a sensor for the purpose of preventing paper jams due to the approach of the sheet interval when resuming after pausing the sheet when it hits the registration roller. A technique is disclosed for delaying the start of feeding of subsequent sheets according to the detected sheet interval.

However, due to paper transport delays, etc., when the transport of paper is temporarily stopped, if the space between the preceding and succeeding sheets of paper is short, or if the preceding and succeeding sheets of paper overlap, sensor There was a problem that the paper interval could not be properly detected because the output did not change.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and it is an object of the present invention to ensure a sheet interval when sheet conveyance is resumed after being temporarily stopped.

In order to solve the above-described problems and achieve the object, an image forming apparatus according to the present invention continuously feeds each of the plurality of sheets from a sheet storage unit that stores the plurality of sheets at a predetermined sheet interval. a detection unit for detecting the presence or absence of the fed sheet on the conveying path of the fed sheet; and an image carrier for forming an image on the image carrier. an image forming section for transferring an image onto the sheet; and when the detecting section does not detect the fed first sheet within a predetermined time after the image is formed on the image carrier, the feeding section. continues the feeding of the first sheet and stops the feeding of the second sheet following the first sheet, and after the feeding of the second sheet is stopped, the detection unit detects the sheet is detected, the image forming section re-forms the image to be formed on the first sheet on the image carrier, and the feeding section resumes feeding the second sheet. characterized by

According to the present invention, it is possible to secure a sheet interval when resuming sheet conveyance after a temporary stop.

FIG. 1 is a diagram illustrating an example of the configuration of a printer (image forming apparatus) according to an embodiment. FIG. 2 is a block diagram showing an example of the hardware configuration of the control system of the printer shown in FIG. FIG. 3 is a block diagram showing an example of functions possessed by the printer in FIG. FIG. 4 is a flow chart showing an example of the flow of image formation executed by the printer according to this embodiment. FIG. 5 is a flow chart showing an example of the flow of image formation on a sheet subsequent to the sheet on which image resending occurs when image resending occurs in the flow of FIG. FIG. 6 is a diagram for explaining a case where, in the flow of image resending in FIG. 4, when an image is resent, transportation of the image resending paper is delayed and the image resending paper overlaps with the succeeding paper. It is a diagram. FIG. 7 is a diagram for explaining the sheet feed interval after image resending occurs in the image resending flow of FIG. 4 .

DETAILED DESCRIPTION OF THE INVENTION Embodiments of an image forming apparatus, an image forming apparatus control method, and a program according to the present invention will be described in detail below with reference to the accompanying drawings.

The technology according to the present embodiment includes a feeding unit that continuously feeds each of the plurality of sheets from a sheet storage unit that stores the plurality of sheets at a predetermined sheet interval, and a conveying path for the fed sheets. The above image forming comprising a detection unit for detecting the presence or absence of the fed sheet, and an image forming unit for forming an image on an image carrier and transferring the image formed on the image carrier to the sheet. In the apparatus, when the detection section does not detect the fed first sheet within a predetermined time after the image is formed on the image carrier, the feeding section stops feeding the first sheet. and stopping the feeding of the second sheet following the first sheet, and when the detecting section detects the first sheet after the feeding of the second sheet is stopped, the image forming section is characterized in that the image to be formed on the first sheet is re-formed on the image carrier, and the feeding section resumes feeding the second sheet. According to these configurations, it is possible to secure a sheet interval when resuming sheet conveyance after a temporary stop.

The image forming apparatus according to the present embodiment uses a medium such as paper, OHP sheet, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, or the like as a "recording medium". is attached to form an image. In the following description, "image formation" means not only giving a meaningful image such as characters and figures to a recording medium, but also giving a meaningless image such as a pattern to a recording medium. also applies. In addition, the term “sheet-like body” is not limited to paper (paper), but also includes OHP sheets, fabrics, etc., and means a medium to which a developer or ink can be adhered. It also includes what is called recording paper. Hereinafter, in the embodiments, the sheet-like body will be described as "paper P". Also, the dimensions, materials, shapes, relative positions, and the like in the description of each component are examples, and are not intended to limit the scope of the present invention unless otherwise specified.

As an example of an image forming apparatus to which the present invention is applied, a tandem color laser printer in which a plurality of image carriers are arranged in parallel will be described below. FIG. 1 is a diagram showing an example of the configuration of a printer 100 (image forming apparatus) according to this embodiment. As shown in FIG. 1, the printer 100 includes image forming units (image forming devices) for forming images of each color of cyan (C), magenta (M), yellow (Y), and black (K). , four process units 1C, 1M, 1Y, and 1K are arranged. The four process units 1C, 1M, 1Y, and 1K have substantially the same configuration except that the toner colors are different.

In the following description, for convenience, C (cyan), M (magenta), Y (yellow), and K (black) are added as suffixes corresponding to the toner colors of the image to be formed after the numbers indicating the constituent members. to decide. For general explanation, these subscripts will be omitted as appropriate. For example, four process units 1C, 1M, 1Y, 1K are described as four process units 1 (C, M, Y, K). Further, for example, when it is not distinguished which one of the four process units 1 (C, M, Y, K) it is, the process unit 1 may be described.

Each of the process units 1 (C, M, Y, K) includes four drum-shaped image carriers 2 (2C, 2M, 2Y, 2K). The image carriers 2 are arranged in parallel at regular intervals in the moving direction of the intermediate transfer belt 16 in the image forming section (image forming device). When the printer 100 operates, each of the image carriers 2 rotates its peripheral surface in the same direction as the conveying direction of the intermediate transfer belt 16 facing each other due to the driving force transmitted from the driving source.

A toner image is formed on the image carrier 2 by an image forming process using a laser beam inside the process unit 1 . A transfer device 15 is arranged below the image carrier 2 . The transfer device 15 has an endless intermediate transfer belt 16 . One end of the intermediate transfer belt 16 is wound around a driven roller 17 and the other end is wound around a transfer drive roller 18 . The intermediate transfer belt 16 runs in the direction of arrow A as a transfer drive roller 18 driven by a drive source rotates, and the surface of each image carrier 2 comes into contact with the upper surface of the intermediate transfer belt 16 . ing. Four primary transfer rollers 19 (Y, C, M, K) are provided on the inner peripheral portion of the intermediate transfer belt 16 so as to face each image carrier 2 .

A belt cleaning device 21 that constitutes an image removing section is provided on the outer periphery near the right end of the intermediate transfer belt 16 . Here, the vicinity of the right end portion of the intermediate transfer belt 16 is, for example, the downstream side position of the secondary transfer portion described later with respect to the intermediate transfer belt 16 running in the direction of the arrow A, and the upstream side of the process unit 1. is the position of The belt cleaning device 21 is a device that wipes away foreign matter such as unnecessary toner and paper dust remaining on the surface of the intermediate transfer belt 16 .

A secondary transfer roller 20 constituting a transfer portion is provided on the outer periphery of the intermediate transfer belt 16 at a position facing the transfer driving roller 18 with the intermediate transfer belt 16 interposed therebetween. The secondary transfer roller 20 contacts the intermediate transfer belt 16 at a position facing the transfer drive roller 18, forming a secondary transfer nip as a secondary transfer portion. In the secondary transfer nip, the toner formed and carried on the intermediate transfer belt 16 is transferred by applying a bias while passing the paper P, which is a recording medium, between the intermediate transfer belt 16 and the secondary transfer roller 20 . The image is electrostatically transferred onto the paper P.

The paper feed tray 30 stores a plurality of sheets of paper P stacked in its internal space. A bottom plate 46 on which sheets P are placed in a stacked state is arranged on the bottom surface of the internal space of the paper feed tray 30 . One longitudinal end of the bottom plate 46 is rotatably supported by a support shaft, and the other longitudinal end of the bottom plate 46 is vertically swingable. The bottom plate 46 is always biased upward by a biasing member such as a spring. Here, the paper feed tray 30 is an example of a sheet storage unit. Also, the plurality of sheets P is an example of a plurality of sheets.

A paper feed roller 47 as a rotating member is arranged in the paper feed tray 30 on the end side where the bottom plate 46 swings. The paper feed roller 47 abuts on the uppermost portion of the stack of paper sheets P stacked on the paper feed tray 30, and can feed out the uppermost paper sheet P. As shown in FIG. Since the paper feed roller 47 only needs to be able to feed the paper P in a predetermined direction, it does not necessarily have to be in the form of a roller. For example, instead of the paper feed roller 47, an endless rotating belt stretched between two rollers may be used.

A registration sensor 31 capable of detecting the edge of the paper P is arranged downstream of the paper feed roller 47 in the feeding direction. Here, the edge of the paper P includes the leading edge and/or the trailing edge of the paper P. The registration sensor 31 is configured, for example, to output ON when the paper P is detected and to output OFF when the paper P is not detected. That is, the registration sensor 31 is configured to be able to detect the presence or absence of the fed paper P on the transport path of the fed paper P. As shown in FIG. Further, a pair of registration rollers 32, which is a medium waiting section for temporarily stopping the paper P, is arranged downstream of the registration sensor 31 in the feeding direction. The registration roller pair 32 is positioned immediately upstream of the intermediate transfer belt 16, and temporarily stops the paper P in order to accurately align the toner image carried on the intermediate transfer belt 16 with the leading edge position of the paper at the transfer portion. to temporarily relax. The registration roller pair 32 moves the sheet P, which has been temporarily stopped, at a predetermined timing immediately before the toner image formed and borne on the intermediate transfer belt 16 is transferred onto the sheet P at the secondary transfer nip portion. Send out to the secondary transfer nip.

A fixing device 34 is arranged downstream of the secondary transfer nip portion formed by the secondary transfer roller 20 and the transfer driving roller 18 in the feeding direction. The fixing device 34 includes a fixing roller 34a containing a heat source such as a halogen lamp, and a pressure roller 34b rotating while contacting the fixing roller 34a with a predetermined pressure. The fixing device 34 may employ an endless rotating belt, an IH heating system, or other configuration.

FIG. 2 is a block diagram showing an example of the hardware configuration of the control system of the printer 100 (image forming apparatus) shown in FIG. As shown in FIG. 2, the printer 100 includes a UART (Universal Asynchronous Receiver Transmitter) 57, a CPU (Central Processing Unit) 58, a ROM (Read Only Memory) 59, a RAM (Random Access Memory) 60, an NVRAM (NonVolatie Random Access Memory). ) 61 , operation panel I/F 62 , I/O 65 and image processing IC (Integrated Circuit) 66 . UART 57 , CPU 58 , ROM 59 , RAM 60 , NVRAM 61 , operation panel I/F 62 , I/O 65 and image processing IC 66 are interconnected via system bus 64 . The ROM 59, RAM 60 and NVRAM 61 constitute a storage unit of the printer 100 according to this embodiment.

UART 57 is an integrated circuit for converting serial signals and parallel signals. Instead of the UART 57, a USART (Universal Synchronous Asynchronous Receiver Transmitter) compatible with synchronous serial communication may be used.

An operation panel 63 is connected to the CPU 58 via an operation panel I/F 62 . The operation panel 63 has a display section and an input section, functions as a user interface, and is used to set the printer mode and the like. The operation panel I/F 62 exchanges data between the CPU 58 and the operation panel 63 via the UART 57, for example. A controller 67 is connected to the CPU 58 via an image processing IC 66 . The CPU 58 acquires printing conditions such as the thickness of the paper to be printed from the controller 67 via the UART 57, for example.

The CPU 58 is a control unit that controls the entire printer 100 (image forming apparatus). The CPU 58 comprehensively controls access to various devices connected to the system bus 64 based on control programs and the like stored in the ROM 59 . The CPU 58 controls input/output of the registration sensor 31, the feed motor 69, the transfer motor 70, the photoreceptor motor 71, and the temperature/humidity sensor 72 which are connected via the UART 57 and I/O 65, for example. In other words, the CPU 58 executes the printer 100 control program stored in the ROM 59 .

The ROM 59 is a read-only non-volatile memory and stores control programs and control data used by the CPU 58 .

The RAM 60 is a volatile memory capable of high-speed reading and writing of information, and is used as a work frame memory used for expanding recording data and storing environmental data.

The NVRAM 61 is a readable/writable non-volatile memory, and stores information about the printer 100 used by the control program.

An operation panel 63 operated by a user is connected to the operation panel I/F 62 . A controller 67 is connected to the image processing IC 66 . The I/O 65 includes a registration sensor 31 that detects that the paper P is being fed, a feed motor 69 that drives the feed roller 47 to rotate, a transfer motor 70 that drives the transfer drive roller 18 to rotate, A photoreceptor motor 71 for rotating the image carrier 2 and a temperature/humidity sensor 72 for selecting the temperature and humidity of the paper P are connected.

FIG. 3 is a block diagram showing an example of functions of the printer 100 (image forming apparatus) in FIG. The CPU 58 measures the feeding time of the paper P, detects a delay in the feeding time, re-forms the image, and restarts registration (re-feeding) in accordance with commands composed of control programs and control data stored in the ROM 59. Each function related to image forming processing such as is realized. As shown in FIG. 3 , the printer 100 has functions as an acquisition unit 101 , a feeding unit 102 , a detection unit 103 , an image forming unit 104 and a notification unit 105 .

Although FIG. 3 mainly illustrates the functions according to the present embodiment for the sake of simplification of explanation, the functions of the printer 100 are not limited to these.

The acquisition unit 101 has a function of acquiring control signals and measured values from the registration sensor 31 , the operation panel 63 , the controller 67 and the temperature/humidity sensor 72 . The acquisition unit 101 has a function of acquiring a print request and image data from a terminal device that issues a print request to the printer 100 .

The feeding unit 102 continuously feeds each of a plurality of sheets P from a sheet feeding tray 30 (sheet storage unit) that stores a plurality of sheets P (a plurality of sheets) at a predetermined sheet interval (sheet feeding interval). It is a function to More specifically, the feeding unit 102 has a function of controlling the feeding of the paper P by controlling the driving of the registration roller pair 32 and the paper feeding roller 47 .

The detection unit 103 has a function of detecting the presence or absence of the paper P on the transport path of the paper P fed under the control of the feeding unit 102 . More specifically, the detection unit 103 has a function of detecting the edge (leading edge/trailing edge) of the paper P based on ON/OFF switching of the registration sensor 31 . In other words, the detection unit 103 can be expressed as a function of monitoring the state of the registration sensor 31 and determining the drawing timing. Further, the detection unit 103 obtains the amount of slippage of the paper P from the arrival time of the paper P to the registration sensor 31 .

The image forming unit 104 has a function of forming an image on the image carrier 2 and transferring the image formed on the image carrier 2 to the paper P. FIG. More specifically, the image forming unit 104 has a function of converting the image data supplied from the acquiring unit into control signals for each color provided in the process unit 1, and controlling writing of a latent image on the image carrier 2; A function to electrophotographically create a toner image from the image data supplied from the acquisition unit and transfer it to the paper P, and a function to apply heat and pressure to the paper P on which the toner image has been transferred to fix the toner image on the paper. including. The image forming unit 104 also includes a function of correcting misalignment when it detects misalignment during printing. Further, the image forming unit 104 includes a function of executing retry processing, which controls the timing of forming an image and the like, and also controls the execution of the image forming process again.

The notification unit 105 has a function of generating display information for notifying the user of occurrence of non-feed jam. The notification unit 105 further includes a function of generating display information for notifying the user that image resending has occurred again after the image resending has occurred and the paper feed interval has been changed.

Next, the operation of the printer 100 according to this embodiment will be described.

First, the basic operation of the printer 100 will be described with reference to FIG. 1 again.

(About feeding operation)
When the paper feed roller 47 of the paper feed tray 30 rotates in response to a paper feed start signal from the printer control section, only the topmost paper P of the paper P stacked on the bottom plate 46 of the paper feed tray 30 is replaced with the lower paper. Separated from P and sent out.

When the leading edge of the paper P is detected by the registration sensor 31, the feeding timing is used as a trigger to feed the paper P until a predetermined slack is formed at the nip portion of the pair of registration rollers 32, thereby correcting the skew of the leading edge of the paper P. do.

(About image creation)
The visible image formed on the image carrier 2K is subjected to the transfer action of the positively charged primary transfer roller 19K onto the surface of the intermediate transfer belt 16 which moves in synchronism with the image carrier 2K, and is primary-transferred. be done. Such operations of latent image formation, development, and primary transfer are successively performed in all the process units 1 (C, M, Y, K) in accordance with the image data. A four-color toner image in which color toner images of cyan C, magenta M, yellow Y, and black K are sequentially superimposed is carried on the surface. This four-color toner image is conveyed together with the intermediate transfer belt 16 that moves in the direction of arrow A on its surface.

When the toner image of each color is transferred to the intermediate transfer belt 16, the registration roller pair 32 and the paper feed roller 47 start driving, and the paper P is transferred so that the timing with the toner image transferred to the intermediate transfer belt 16 is matched. It is fed to the secondary transfer roller 20 which is the position. It should be noted that the driving of the registration roller pair 32 and the paper feeding roller 47 does not necessarily have to start at the same time. In addition to the registration roller pair 32 and the paper feed roller 47, a paper feed roller for feeding the paper P may be provided. The secondary transfer roller 20 is positively charged, and the toner image on the intermediate transfer belt 16 is transferred to the fed sheet P by the secondary transfer nip portion of the secondary transfer roller 20 . Residual toner and foreign matter on the surface of the intermediate transfer belt 16 are removed by the belt cleaning device 21 for the next image forming/transfer process.

The paper P onto which the toner image has been transferred is sent to the fixing device 34 after the transfer. The paper P sent to the fixing device 34 is sandwiched between the fixing roller 34a and the pressure roller 34b, and the unfixed toner image is heated/pressurized to be fixed on the paper P. FIG.

FIG. 4 is a flow chart showing an example of the flow of image formation executed by the printer 100 according to this embodiment. In the flow of FIG. 4, print processing (image forming processing) is started, for example, when the acquisition unit 101 acquires a print request from a terminal device. When the print process is started, the acquiring unit 101 supplies the image forming unit 104 with the image data received together with the print request from the terminal device.

In step S101, the image forming unit 104 starts an image forming process. More specifically, the image forming section 104 converts the image data from the acquiring section 101 into control signals for the respective colors of the process unit 1 . The image forming section 104 supplies the converted control signal to the process unit 1 . The image forming section 104 activates each motor to start the image forming process in the process unit 1 .

In step S102, the detection unit 103 starts measuring the registration restart time.

In step S103, the feeding unit 102 starts the paper feeding process. More specifically, the feeding unit 102 drives the feeding motor 69 to rotate the feeding roller 47 to which the feeding motor 69 is coupled via an electromagnetic clutch, thereby stacking the sheets stacked on the feeding tray 30 . A paper feed process is started to feed the paper P at predetermined paper intervals.

In step S104, the detection unit 103 starts measuring the jam detection time.

In step S105, the detection unit 103 determines whether or not the registration sensor 31 is turned on. It is assumed that the registration sensor 31 is turned on when the paper P is detected. That is, the detection unit 103 determines whether or not the leading edge of the paper P fed from the paper feed tray 30 has reached the registration sensor 31 in the paper feed process started in step S103. The flow of FIG. 4 proceeds to step S107 when it is determined that the leading edge of the paper P has reached the registration sensor 31, and proceeds to step S106 when it is not determined.

In this embodiment, the case where the detection unit 103 makes a determination based on the output of the registration sensor 31 will be described as an example, but the present invention is not limited to this. The sensor output used for the determination by the detection unit 103 may be any sensor output that can confirm normal conveyance of the paper, regardless of the sensor position.

In step S106, the detection unit 103 determines whether or not a predetermined registration restart time has elapsed. It is assumed that the predetermined registration restart time is set in advance and stored in a storage unit or the like, for example. That is, in this step, it is determined whether or not the predetermined registration restart time has elapsed while the leading edge of the paper P has not reached the registration sensor 31 . The flow in FIG. 4 proceeds to step S111 if it is determined that the predetermined registration restart time has elapsed, and returns to step S105 if not determined.

(Regarding normal print processing)
First, the flow when the leading edge of the paper P reaches the registration sensor 31 before the predetermined jam detection time and registration restart time elapse will be described. That is, the flow of steps S107 to S110 below is the flow when the paper P is fed in time for image formation.

In step S107, the feeding unit 102 restarts registration when, for example, a predetermined registration restart time has elapsed. More specifically, the feeding section 102 drives the registration roller pair 32 to feed the preceding sheet P to the secondary transfer roller 20 . Further, the feeding unit 102 resumes driving the paper feeding roller 47 and starts the feeding process for the succeeding paper P. FIG.

Before reaching this step, the leading edge of the paper P should be slackened by the pair of registration rollers 32 to a predetermined degree during the time from when the paper feed clutch is connected until the predetermined registration restart time elapses. being shipped. In other words, it is assumed that this step is started in a state in which the paper feed clutch is disconnected and the paper P is waiting to stop the rotation of the paper feed roller 47 .

In step S<b>108 , the feeding unit 102 transfers the registration rollers 20 to the registration rollers 20 at the timing when the positions of the toner image borne on the intermediate transfer belt 16 and the sheet P waiting on the registration roller pair 32 are aligned. A feed motor 69 is drivingly connected to the pair 32 via a resist clutch to feed the paper P to the secondary transfer nip portion of the secondary transfer roller 20 . The image forming section 104 transfers the toner image onto the paper P with the secondary transfer roller 20 .

Before reaching this step, the toner image is transferred to the intermediate transfer belt 16 by the primary transfer roller 19 and transferred to the secondary transfer roller 20 by the intermediate transfer belt 16 in the image forming process started in step S101. It is assumed that the

In step S<b>109 , the feeding section 102 feeds the paper P onto which the toner image has been transferred to the fixing device 34 . The image forming section 104 also performs a fixing process in the fixing device 34 .

In step S<b>110 , the feeding unit 102 discharges the paper P on which the toner image has been fixed by the fixing device 34 to the outside of the printer 100 . After that, the printing process ends.

(Regarding print processing when images are resent)
Next, a description will be given of the flow when the predetermined registration restart time has elapsed while the leading edge of the paper P has not reached the registration sensor 31 .

In step S111, the image forming unit 104 stops image formation. The feeding unit 102 continues to transport the paper P. On the other hand, the feeding unit 102 interrupts the feeding of the succeeding paper P.

In step S<b>112 , the detection unit 103 determines whether or not the leading edge of the fed sheet P has reached the registration sensor 31 in the same manner as in step S<b>105 . The flow in FIG. 4 proceeds to step S114 if it is determined that the leading edge of the paper P has reached the registration sensor 31, and proceeds to step S113 if not determined.

In step S113, the detection unit 103 determines whether or not a predetermined jam detection time has elapsed. For example, it is assumed that the predetermined jam detection time is set in advance and stored in a storage unit or the like. In other words, in this step, it is determined whether or not a predetermined jam detection time has elapsed while the leading edge of the paper P has not reached the registration sensor 31 . The flow in FIG. 4 proceeds to step S116 if it is determined that the predetermined jam detection time has elapsed, and returns to step S112 if not determined.

In step S114, the image forming unit 104 restarts the image forming process. More specifically, the image forming unit 104 re-forms the image in the same manner as in step S101. Further, the detection unit 103 starts measuring the registration restart time.

In step S115, the feeding unit 102 resumes registration in the same manner as in step S107. However, unlike step S107, the feeding unit 102 does not start the feeding process for the succeeding sheet P in this step. After that, the flow in FIG. 4 proceeds to step S108, and secondary transfer, fixing, and paper ejection are performed for the paper P whose feeding is restarted.

After it is determined in step S106 that the predetermined registration elapsed time has elapsed, image re-formation (redrawing) and ejection are performed in the flow of steps S111, S114, S115, S108, S109 and S110. The operation is called image resend.

(Regarding print processing when a jam occurs)
Here, a case where a predetermined jam detection time has elapsed while the leading edge of the paper P has not reached the registration sensor 31 (step S113/Yes) will be described.

In step S116, the detection unit 103 determines that a jam has occurred. That is, in this step, it is determined that there is a non-feed jam. When it is determined that a non-feed jam has occurred, the notification unit 105 generates display information for notifying the user that a non-feed jam has occurred. The generated display information is supplied to the operation panel 63 . The operation panel 63 displays that a non-feed jam has occurred based on the supplied display information. As the display information, a character string such as an error code, a preset figure, or the like can be used. Note that the user may be notified by blinking the display screen or changing the color of the display screen.

In step S117, printing is interrupted. The flow of FIG. 4 then ends.

Here, an example of the flow of image formation on a sheet P subsequent to the sheet P on which image resending has occurred (hereinafter referred to as an image resending sheet) (hereinafter referred to as subsequent sheet) will be described. FIG. 5 is a flow chart showing an example of the flow of image formation on a sheet subsequent to the sheet on which image resending occurs when image resending occurs in the flow of FIG.

In step S201, the feeding unit 102 stops feeding the succeeding paper. The flow of this step corresponds to the flow of step S111 in FIG. That is, when the feeding of the succeeding paper is stopped in this step, the feeding of the image resending paper is not stopped.

In step S<b>202 , the detection unit 103 starts measuring time by the paper interval securing timer. Here, the paper interval securing timer is set by, for example, the time required to transport the maximum length of paper that can be transported.

In step S203, the detection unit 103 determines whether or not the paper interval ensuring timer has timed out. In other words, this step can be expressed as a step of determining whether or not there is a sufficient gap between the sheet P on which image resending has occurred (image resending sheet) and the succeeding sheet P (following sheet). . In the flow of FIG. 5, the process is repeated until it is determined that the paper space ensuring timer has timed out, and when it is determined that the paper space ensuring timer has timed out, the process proceeds to step S204.

In step S204, the feeding unit 102 resumes transporting the succeeding sheet.

The flow of steps S205 to S207 is the same as the flow of steps S108 to S110 in FIG. 4, and secondary transfer, fixing, and paper discharge are performed for the succeeding paper whose feeding is restarted. After the paper discharge operation is performed in step S207, the flow of FIG. 5 ends.

FIG. 6 is a diagram for explaining a case in which, in the flow of image resending in FIG. 4, when image resending occurs, transportation of the image resending paper is delayed and the image resending paper overlaps with the succeeding paper. It is a diagram. As described with reference to FIG. 4, the printing process when the image is resent is the printing process when the predetermined registration restart time has passed while the leading edge of the paper P has not reached the registration sensor 31. When the transportation of the image resending paper is delayed in this manner, the image resending paper and the succeeding paper may overlap as shown in the upper part of FIG. If the image resending paper and the succeeding paper overlap and are conveyed, the registration sensor 31 will not be turned off forever, so it will be judged as a jam. Further, when the registration roller pair 32 and the paper feed roller 47 are driven in a state where the image resending paper and the succeeding paper are overlapped, paper jam may occur.

Under such circumstances, the printer 100 according to the present embodiment can stop the transport of only the succeeding paper when the image is resent as described above. In other words, according to the technique according to the present embodiment, as shown in the lower part of FIG. 6, there is an effect that it is possible to secure the interval between the image resending paper and the succeeding paper. Further, according to the control for ensuring the sheet interval according to the present embodiment, there is an effect that the overlapping of the sheets can be eliminated. In other words, there is an effect that it becomes possible to discharge without jamming.

FIG. 7 is a diagram for explaining the paper feed interval (paper interval) after image resending occurs in the image resending flow of FIG. In the example shown in FIG. 7, image retransmission occurs for sheet 2 .

Since the image of the paper 1 is not resent, the feeding of the subsequent paper 2 is started in the normal printing process for the paper 1 . The sheet interval at this time is the interval A.

After that, the image resending of the paper 2 occurs, so the paper feeding of the paper 3 is temporarily interrupted. As described above, the paper 3 resumes being conveyed after the paper interval timer times out. The paper interval between the paper 2 and the paper 3 when the feeding of the paper 3 is restarted is the interval B. FIG.

After the image is resent in this manner, the feeding unit 102 sets the interval B as the sheet interval for the sheet 4 subsequent to the sheet 3 . That is, when image resending occurs, the feeding unit 102 sets the sheet interval (interval B) between the image resending paper and the succeeding paper as the subsequent paper interval.

If a slippery sheet is set, there is a possibility that the transport of subsequent sheets will also be delayed. However, according to this configuration, it is possible to secure a feeding interval corresponding to the degree of slippage of the subsequent sheets. In other words, according to the technique of the present embodiment, it is possible to prevent paper jams due to narrowing of the feeding interval after image resending occurs.

It should be noted that after the paper interval is changed (for example, enlarged) due to the occurrence of image resending, image resending may occur. In this case, the notification unit 105 generates display information for notifying the user that an image has been resent due to a delay in sheet transportation with the sheet feeding interval extended, for example, in the same manner as in step S117. According to this configuration, it is possible to notify the user that many slips have occurred, so that there is an effect that the user can be given an opportunity to review the paper.

In the above-described embodiment, the case where the feeding of subsequent sheets is resumed when the timer between sheets times out has been described as an example, but the present invention is not limited to this. For example, feeding of the succeeding paper may be restarted at the timing when the trailing edge of the paper causing image resending passes the registration sensor 31 arranged downstream from the leading edge of the succeeding paper on the transport path. The timing at which the trailing edge of the image resending paper passes the registration sensor 31 is the timing at which the registration sensor 31 turns off after the leading edge of the image resending paper reaches the registration sensor 31 and the registration sensor 31 turns on. is. According to the technology according to the above-described embodiments, when image resending occurs, the feeding of the image resending paper is continued while the subsequent paper is interrupted. can be prevented from being conveyed while overlapping each other. That is, according to the technique according to the above-described embodiment, it is possible to avoid a situation in which the registration sensor 31 is never turned off. can also By restarting the transport of the succeeding paper at the timing when the sensor on the transport path is detected to be OFF, it is possible to prevent the occurrence of paper jams and suppress the decrease in productivity.

In the above-described embodiment, a case in which a sheet-shaped object is conveyed by the printer 100 (image forming apparatus) has been described as an example, but the present invention is not limited to this. The technology according to the above-described embodiments can also be applied to conveyed objects having other sheet-like shapes and apparatuses performing other operations such as image formation. For example, according to the technology according to the above-described embodiments, it is possible to secure a transport interval in an apparatus in which a predetermined operation such as labeling is performed on a non-sheet-shaped transported object such as a cardboard box.

Note that an image forming program executed by the printer 100 (image forming apparatus) according to the present embodiment is preinstalled in a ROM or the like and provided.

The image forming program executed by the printer 100 (image forming apparatus) of the present embodiment is a file in an installable format or an executable format and can be stored on a CD-ROM, flexible disk (FD), CD-R, DVD (Digital Versatile). It may be configured to be recorded in a computer-readable recording medium such as a disk) and provided.

Furthermore, the image forming program executed by the printer 100 (image forming apparatus) of this embodiment is stored on a computer connected to a network such as the Internet, and is configured to be provided by being downloaded via the network. Also good. Further, the image forming program executed by the printer 100 (image forming apparatus) of this embodiment may be provided or distributed via a network such as the Internet.

The image forming program executed by the printer 100 (image forming apparatus) of this embodiment has a module configuration including the above-described units (acquisition unit 101, feeding unit 102, detection unit 103, image forming unit 104, and notification unit 105). As actual hardware, a CPU (processor) reads out an image forming program from the ROM and executes it, thereby loading each of the above sections onto the main storage device, and obtaining section 101, feeding section 102, detection A unit 103, an image forming unit 104, and a notification unit 105 are generated on the main storage device.

In the above embodiments, an example in which the image forming apparatus of the present invention is applied to a multifunction machine having at least two functions out of a copy function, a printer function, a scanner function, and a facsimile function will be described. Any image forming apparatus such as a printer, a scanner, a facsimile, etc. can be used.

1 (1C, 1M, 1Y, 1K) process unit 2 (2C, 2M, 2Y, 2K) image carrier 15 transfer device 16 intermediate transfer belt 17 driven roller 18 transfer drive roller 19 (19C, 19M, 19Y, 19K) primary Transfer roller 20 Secondary transfer roller 21 Belt cleaning device 30 Paper feed tray (sheet storage unit)
31 registration sensor 32 registration roller pair 34 fixing device 34a fixing roller 34b pressure roller 46 bottom plate 47 paper feeding roller 57 UART
58 CPUs
59 ROMs
60 RAM
61 NVRAM
62 Operation panel I/F
63 Operation panel 64 System bus 65 I/O
66 Image processing IC
67 controller 69 feeding motor 70 transfer motor 71 photoreceptor motor 72 temperature and humidity sensor 100 printer (image forming apparatus)
101 Acquisition Unit 102 Feeding Unit 103 Detection Unit 104 Image Forming Unit 105 Notification Unit P Paper

JP 2003-306254 A

Claims (6)

a feeding unit that continuously feeds each of the plurality of sheets at a predetermined sheet interval from a sheet storage unit that stores the plurality of sheets;
a detection unit that detects the presence or absence of the fed sheet on the conveying path of the fed sheet;
an image forming unit that forms an image on an image carrier and transfers the image formed on the image carrier to the sheet;
When the detection unit does not detect the fed first sheet within a predetermined time after the image is formed on the image carrier,
the feeding unit continues feeding the first sheet and stops feeding a second sheet following the first sheet;
when the detection unit detects the first sheet after the feeding of the second sheet is stopped;
The image forming unit re-forms the image to be formed on the first sheet on the image carrier,
the feeding unit restarts feeding the second sheet;
Image forming device. When the feeding of the second sheet is restarted, the feeding section sets the predetermined sheet interval in subsequent feeding to the sheet interval between the first sheet and the second sheet. 2. The image forming apparatus of claim 1, wherein the image forming apparatus is modified. The image forming section re-forms the image to be formed on the first sheet on the image carrier when the detection section detects the leading edge of the first sheet after the feeding of the second sheet is stopped. ,
The feeding unit resumes feeding the second sheet when the detecting unit detects the trailing edge of the first sheet after stopping the feeding of the second sheet.
The image forming apparatus according to claim 1 or 2. When the third sheet fed after restarting the feeding of the second sheet is not detected by the detection unit within a predetermined time after the image is formed on the image carrier, the predetermined sheet interval is increased. 4. The image forming apparatus according to any one of claims 1 to 3 , further comprising a notification unit that generates display information for presenting to a user that image retransmission has occurred in a state where the image has been resent. a step of continuously feeding each of the plurality of sheets from a sheet storage unit storing the plurality of sheets at a predetermined sheet interval;
detecting the presence or absence of the fed sheet on the conveying path of the fed sheet;
forming an image on an image carrier and transferring the image formed on the image carrier to the sheet;
when the fed first sheet is not detected within a predetermined time after the image is formed on the image carrier;
the step of feeding includes continuing feeding of the first sheet and stopping feeding of a second sheet following the first sheet;
When the first sheet is detected after the feeding of the second sheet is stopped,
forming the image includes re-forming the image to be formed on the first sheet on the image carrier;
the step of feeding includes resuming feeding of the second sheet;
A control method for an image forming apparatus. a step of continuously feeding each of the plurality of sheets from a sheet storage unit storing the plurality of sheets at a predetermined sheet interval;
detecting the presence or absence of the fed sheet on the conveying path of the fed sheet;
A program for causing a computer installed in an image forming apparatus to execute a step of forming an image on an image carrier and transferring the image formed on the image carrier to the sheet,
when the fed first sheet is not detected within a predetermined time after the image is formed on the image carrier;
the step of feeding includes continuing feeding of the first sheet and stopping feeding of a second sheet following the first sheet;
When the first sheet is detected after the feeding of the second sheet is stopped,
forming the image includes re-forming the image to be formed on the first sheet on the image carrier;
the step of feeding includes resuming feeding of the second sheet;
program.

Images