JP2021043355A - Image forming apparatus, control method for image forming apparatus, and program - Google Patents

Abstract

To ensure an interval between sheets when temporarily stopping and then resuming conveyance of sheets.SOLUTION: An image forming apparatus comprises: a feeding unit that continuously feeds, from a sheet storage unit storing a plurality of sheets, each of the plurality of sheets at a predetermined sheet interval; a detection unit that detects presence or absence of the fed sheets on a conveyance path of the fed sheets; and an image forming unit that forms images on image carriers and transfers the images formed on the image carriers to the sheets. When the detection unit does not detect a fed first sheet within a predetermined time since when the images are formed on the image carriers, the feeding unit continues feeding of the first sheet and stops feeding of a second sheet subsequent to the first sheet, and when the detection unit detects the first sheet after the stop of feeding of the second sheet, the image forming unit forms the images to be formed on the first sheet on the image carriers again, and the feeding unit resumes feeding of the second sheet.SELECTED DRAWING: Figure 3

Description

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

Conventionally, there is an image forming apparatus configured to be able to stop the paper between the paper feeding unit and the image transfer unit. In such an image forming apparatus, even if it is determined that the paper is not in time for the transfer of the drawn image, it is not determined as a paper jam, the paper is conveyed to the resist position and then stopped, and then the image is redrawn. There is known a retry function (hereinafter, referred to as an "image retransmission function") that can restart the transfer by performing the transfer.

In Patent Document 1, the paper spacing is detected based on the sensor output for the purpose of preventing a paper jam due to the paper spacing approaching when the paper is paused and then restarted when the resist roller is abutted. A technique for delaying the start of feeding of subsequent paper according to the detected paper interval is disclosed.

However, if the space between the preceding paper and the succeeding paper is narrowed or the preceding paper and the succeeding paper overlap when the paper transport is temporarily stopped due to a paper transport delay or the like, the sensor is used. There is a problem that the paper spacing cannot be detected properly because the output does not change.

The present invention has been made in view of the above, and an object of the present invention is to secure a sheet interval when the sheet transport is paused and then restarted.

In order to solve the above-mentioned problems and achieve the object, the image forming apparatus according to the present invention continuously feeds each of the plurality of sheets from the sheet storage unit for storing the plurality of sheets at predetermined sheet intervals. An image is formed on the image carrier, the image carrier, the image carrier, the image carrier, the image carrier, the image carrier, the image carrier, the image carrier, the image carrier, the image carrier, the image carrier, the image carrier, the image carrier, and the image carrier. When the detection unit does not detect the first sheet fed within a predetermined time after the image is formed on the image carrier, the feeding unit is provided with an image forming unit that transfers an image to the sheet. 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 performs the first. When the sheet is detected, the image forming unit reshapes the image formed on the first sheet into the image carrier, and the feeding unit restarts the feeding of the second sheet. It is characterized by.

According to the present invention, there is an effect that the sheet spacing can be secured when the sheet transport is temporarily stopped and then restarted.

FIG. 1 is a diagram showing an example of a 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 of FIG. FIG. 3 is a block diagram showing an example of the functions of the printer of FIG. FIG. 4 is a flowchart showing an example of the flow of image formation executed in the printer according to the present embodiment. FIG. 5 is a flowchart showing an example of the flow of image formation regarding the subsequent paper of the image retransmission generation paper when the image retransmission occurs in the flow of FIG. FIG. 6 is for explaining a case where the image retransmission generation paper and the subsequent paper overlap each other due to the delay in transporting the image retransmission generation paper when the image retransmission occurs in the image retransmission flow of FIG. It is a figure. FIG. 7 is a diagram for explaining the paper feed interval after the occurrence of image retransmission in the flow of image retransmission in FIG.

Hereinafter, the image forming apparatus according to the present invention, the control method of the image forming apparatus, and the embodiment of the program will be described in detail with reference to the accompanying drawings.

The technique 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 a plurality of sheets at predetermined sheet intervals, and a transport path for the fed sheets. Image formation including the detection unit for detecting the presence or absence of the fed sheet and the image forming unit for forming an image on the image carrier and transferring the image formed on the image carrier to the sheet. In the apparatus, when the detection unit does not detect the first sheet to which the image carrier has been fed within a predetermined time after the image is formed on the image carrier, the feeding unit feeds the first sheet. When the feeding of the second sheet following the first sheet is stopped and the detection unit detects the first sheet after the feeding of the second sheet is stopped, the image forming unit Is characterized in that the image formed on the first sheet is reformed on the image carrier, and the feeding unit restarts feeding of the second sheet. According to these configurations, it is possible to secure the sheet spacing when the sheet transfer is temporarily stopped and then restarted.

The image forming apparatus according to the present embodiment uses a medium such as paper, OHP sheet, thread, fiber, cloth, leather, metal, plastic, glass, wood, and ceramics as a "recording medium", and a developer or ink is used as the storage medium. It is a device that forms an image by adhering. In the following description, "image formation" not only imparts an image having meaning such as characters and figures to the recording medium, but also imparts an image having no meaning such as a pattern to the recording medium. That also applies. Further, the "sheet-like body" includes not only paper (paper) but also OHP sheets, fabrics, etc., and means a medium to which a developer or ink can be attached, and is a recording medium, a recording medium, a recording paper, etc. It also includes what is called recording paper. Hereinafter, in the embodiment, the sheet-like body will be described as "paper P". Further, the dimensions, materials, shapes, relative arrangements thereof, etc. in the description of each component are examples, and the scope of the present invention is not intended to be limited thereto unless otherwise specified.

Hereinafter, as an example of the image forming apparatus to which the present invention is applied, a tandem type color laser printer in which a plurality of image carriers are arranged in parallel will be described as an example. FIG. 1 is a diagram showing an example of the configuration of the printer 100 (image forming apparatus) according to the present embodiment. As shown in FIG. 1, an image forming unit (image forming apparatus) for forming images of each color of cyan (C), magenta (M), yellow (Y), and black (K) is inside the printer 100. As a result, four process units 1C, 1M, 1Y, and 1K are arranged. The four process units 1C, 1M, 1Y, and 1K all have almost 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 subscripts to correspond to the toner color of the image to be imaged after the number indicating the component. I will decide. In the case of general explanation, these subscripts are omitted as appropriate. For example, the 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 of the four process units 1 (C, M, Y, K) it is, it may be described as process unit 1.

Each process unit 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 equal intervals in the moving direction of the intermediate transfer belt 16 in the image forming portion (image forming apparatus). When the printer 100 is operating, the peripheral surfaces of each of the image carriers 2 rotate in the same direction as the transport direction of the intermediate transfer belts 16 that face each other because the drive is transmitted from the drive 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 the driven roller 17, and the other end is wound around the transfer drive roller 18. The intermediate transfer belt 16 travels in the direction of arrow A by rotating the transfer drive roller 18 driven by the drive source, 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 constituting an image removing portion is provided on the outer peripheral portion of the intermediate transfer belt 16 near the right end portion. Here, the vicinity of the right end portion of the intermediate transfer belt 16 is, for example, a position on the downstream side of the secondary transfer portion described later with respect to the intermediate transfer belt 16 traveling in the direction of the arrow A, and is on the upstream side of the process unit 1. The position of. The belt cleaning device 21 is a device for wiping off unnecessary foreign matter such as toner and paper dust remaining on the surface of the intermediate transfer belt 16.

On the outer circumference of the intermediate transfer belt 16, a secondary transfer roller 20 constituting a transfer portion is provided at a position facing the transfer drive roller 18 with the intermediate transfer belt 16 interposed therebetween. The secondary transfer roller 20 abuts on the intermediate transfer belt 16 at a position facing the transfer drive roller 18 to form a secondary transfer nip as a secondary transfer portion. In the secondary transfer nip, the toner formed and supported on the intermediate transfer belt 16 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 to the paper P.

The paper feed tray 30 stacks and stores a plurality of sheets of paper P in its internal space. On the bottom surface of the internal space of the paper feed tray 30, a bottom plate 46 for loading the paper P in a laminated state is arranged. One end of the bottom plate 46 in the longitudinal direction is rotatably supported by a support shaft, and the other end can swing in the vertical direction. The bottom plate 46 is always urged upward by an urging member such as a spring. Here, the paper feed tray 30 is an example of a sheet storage unit. Further, the plurality of sheets P is an example of a plurality of sheets.

A paper feed roller 47 as a rotating member is arranged on the paper feed tray 30 on the end side where the bottom plate 46 swings. The paper feed roller 47 comes into contact with the uppermost portion of the bundle of paper P placed on the paper feed tray 30 in a stacked state, and can feed out the uppermost paper P. The paper feed roller 47 does not necessarily have to be in the form of a roller, as long as the paper P can be fed in a predetermined direction. For example, instead of the paper feed roller 47, an endless rotating belt spanned between the two rollers may be used.

A resist 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 end portion of the paper P includes the front end and / or the rear end of the paper P. The resist sensor 31 is configured to output ON (ON) when the paper P is detected and OFF (OFF) when the paper P is not detected, for example. That is, the resist sensor 31 is configured to be able to detect the presence or absence of the fed paper P on the transport path of the paper P to be fed. Further, a resist roller pair 32, which is a medium standby unit for temporarily stopping the paper P, is arranged downstream of the resist sensor 31 in the feeding direction. The resist roller pair 32 is located on the immediate upstream side of the intermediate transfer belt 16, and temporarily stops the paper P in order to accurately align the toner image supported on the intermediate transfer belt 16 with the position of the paper tip in the transfer portion. Temporarily loosen. The resist roller pair 32 is formed at a predetermined timing on the paper P which has been temporarily stopped immediately before the toner image formed and supported on the intermediate transfer belt 16 is transferred to the paper P at the secondary transfer nip portion. Send to the secondary transfer nip.

A fixing device 34 is arranged further downstream in the feeding direction than the secondary transfer nip portion by the secondary transfer roller 20 and the transfer drive roller 18. The fixing device 34 includes a fixing roller 34a including a heat generating source such as a halogen lamp, and a pressurizing roller 34b that rotates while abutting on the fixing roller 34a at a predetermined pressure. The fixing device 34 may have an endless rotating belt or another configuration such as an IH heating method.

FIG. 2 is a block diagram showing an example of the hardware configuration of the control system of the printer 100 (image forming apparatus) of 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, and an NVRAM (NonVolatie Random Access Memory). ) 61, an operation panel I / F62, I / O65, and an image processing IC (Integrated Circuit) 66. The UART 57, CPU 58, ROM 59, RAM 60, NVRAM 61, operation panels I / F 62, I / O 65 and the image processing IC 66 are connected to each other via the system bus 64. The ROM 59, the RAM 60, and the NVRAM 61 constitute a storage unit of the printer 100 according to the present embodiment.

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

The operation panel 63 is connected to the CPU 58 via the operation panel I / F 62. The operation panel 63 includes a display unit and an input unit, functions as a user interface, and is used for setting a printer mode and the like. The operation panel I / F 62 exchanges data between the CPU 58 and the operation panel 63, for example, via the UART 57. Further, the controller 67 is connected to the CPU 58 via the 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, for example, the UART 57.

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 a control program or the like stored in the ROM 59. The CPU 58 controls the input / output of the resist sensor 31, the feed motor 69, the transfer motor 70, the photoconductor motor 71, and the temperature / humidity sensor 72, which are connected via, for example, the UART 57 and the I / O 65. In other words, the CPU 58 executes the control program of the printer 100 stored in the ROM 59.

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

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

The NVRAM 61 is a non-volatile memory that can be read and written, and stores information about the printer 100 used by the control program.

An operation panel 63 operated by the 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 rotationally drives the paper feed roller 47, and a transfer motor 70 that rotationally drives the transfer drive roller 18. A photoconductor motor 71 that rotationally drives the image carrier 2 and a temperature / humidity sensor 72 that selects the temperature and humidity of the paper P are connected to each other.

FIG. 3 is a block diagram showing an example of the functions of the printer 100 (image forming apparatus) of FIG. The CPU 58 measures the feeding time of the paper P, detects a delay in the feeding time, reshapes the image, and restarts the resist (refeeding) according to an instruction composed of the control program and control data stored in the ROM 59. Each function related to image formation 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.

Note that FIG. 3 mainly illustrates the functions according to the present embodiment for the sake of simplicity, but the functions of the printer 100 are not limited to these.

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

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

The detection unit 103 is 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 is a function of detecting the end portion (front end / rear end) of the paper P based on the on / off switching of the resist sensor 31. That is, it can be expressed that the detection unit 103 is a function of monitoring the state of the resist sensor 31 and determining the drawing timing. Further, the detection unit 103 obtains the slip amount of the paper P from the arrival time of the paper P to the resist sensor 31.

The image forming unit 104 is 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. More specifically, the image forming unit 104 has a function of converting the image data supplied from the acquisition unit into control signals for each color included in the process unit 1 and controlling the writing of the latent image on the image carrier 2. A function to create a toner image from the image data supplied from the acquisition unit by an electrophotographic method and transfer it to paper P, and a function to apply heat and pressure to the paper P to which the toner image has been transferred to fix the toner image on the paper. including. Further, the image forming unit 104 includes a function of correcting the misalignment when it is detected during printing. Further, the image forming unit 104 includes a function of executing a retry process that controls the image forming timing and the like and also controls such as executing the image forming process again.

The notification unit 105 is a function of generating display information for notifying the user of the occurrence of non-paper feed jam. The notification unit 105 further includes a function of generating display information for notifying the user that the image retransmission has occurred again after the image retransmission 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 is rotated by the feed start signal from the printer control unit, only the top paper P of the paper P loaded on the bottom plate 46 of the paper feed tray 30 is the lower paper. It is separated from P and sent out.

When the tip of the paper P is detected by the resist sensor 31, the paper P is fed until a predetermined slack is formed in the nip portion of the resist roller pair 32 triggered by the feeding timing, and the tip skew of the paper P is corrected. To do.

(About image formation)
The visible image imaged on the image carrier 2K undergoes a transfer action by a positively charged primary transfer roller 19K on the surface of the intermediate transfer belt 16 that moves in synchronization with the image carrier 2K to perform primary transfer. Will be done. Such operations of latent image formation, development, and primary transfer are sequentially performed in all process units 1 (C, M, Y, K) in a timely manner corresponding to the image data, and the intermediate transfer belt 16 is used. A four-color toner image in which cyan C, magenta M, yellow Y, and black K color toner images are sequentially overlapped is supported on the surface. The four-color toner image is conveyed together with the intermediate transfer belt 16 that moves on the surface in the direction of arrow A.

When each color toner image is transferred to the intermediate transfer belt 16, the resist roller pair 32 and the paper feed roller 47 start driving, and the paper P is transferred so as to match the timing with the toner image transferred to the intermediate transfer belt 16. It is fed to the secondary transfer roller 20 at the position. It should be noted that the drive start of the resist roller pair 32 and the paper feed roller 47 does not necessarily have to be started at the same time. Further, in addition to the resist roller pair 32 and the paper feed roller 47, there may be a paper feed roller that feeds the paper P. The secondary transfer roller 20 is positively charged, and the toner image on the intermediate transfer belt 16 is transferred to the paper P sent 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 formation / transfer step.

The paper P on which the toner image is transferred is transferred to the fixing device 34 after the transfer. The paper P fed 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 and fixed to the paper P.

FIG. 4 is a flowchart showing an example of the flow of image formation executed in the printer 100 according to the present embodiment. In the flow of FIG. 4, the printing process (image forming process) is started in response to, for example, the acquisition unit 101 acquiring a print request from the terminal device. When the printing process is started, the acquisition unit 101 supplies the image data received from the terminal device together with the print request to the image forming unit 104.

In step S101, the image forming unit 104 starts the image forming process. More specifically, the image forming unit 104 converts the image data from the acquisition unit 101 into control signals for each color included in the process unit 1. The image forming unit 104 supplies the converted control signal to the process unit 1. The image forming unit 104 starts each motor and starts the image forming process in the process unit 1.

In step S102, the detection unit 103 starts measuring the resist 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 paper feeding roller 47 to which the feeding motor 69 is connected via an electromagnetic clutch, and is laminated on the paper feeding tray 30. The paper feeding process of feeding the paper P at predetermined paper intervals is started.

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 resist sensor 31 is turned on. It is assumed that the resist sensor 31 is turned on when the paper P is detected. That is, the detection unit 103 determines whether or not the tip of the paper P fed from the paper feed tray 30 has reached the resist 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 tip of the paper P has reached the resist sensor 31, and proceeds to step S106 when it is not determined.

In the present embodiment, the case where the detection unit 103 determines based on the output of the resist sensor 31 will be described as an example, but the present invention is not limited to this. The sensor output used by the detection unit 103 for determination may be the output of a sensor that can confirm the normal transfer of paper, and the sensor position does not matter.

In step S106, the detection unit 103 determines whether or not a predetermined resist restart time has elapsed. It is assumed that the predetermined resist restart time is set in advance and stored in a storage unit or the like. That is, in this step, it is determined whether or not the predetermined resist restart time has elapsed without the tip of the paper P reaching the resist sensor 31. The flow of FIG. 4 proceeds to step S111 when it is determined that the predetermined resist restart time has elapsed, and returns to step S105 when it is not determined.

(About normal printing process)
First, the flow when the tip of the paper P reaches the resist sensor 31 before the predetermined jam detection time and the resist restart time have elapsed will be described. That is, the following flow of steps S107 to S110 is a flow when the feeding of the paper P is in time for image formation.

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

By the time this step is reached, a predetermined slack is formed at the tip of the paper P by the resist roller pair 32 in the time from when the paper feed clutch is engaged until the predetermined resist restart time elapses. It has been sent. That is, it is assumed that this step is started in a state where the connection drive of the paper feed clutch is released in order to stop the rotation of the paper feed roller 47 and the paper P is on standby.

In step S108, the feeding unit 102 uses the secondary transfer roller 20 at a timing at which the toner image carried on the intermediate transfer belt 16 and the paper P waiting on the resist roller pair 32 are aligned with each other. The feed motor 69 is driven and connected to the pair 32 via a resist clutch, and the paper P is fed to the secondary transfer nip portion of the secondary transfer roller 20. The image forming unit 104 transfers the toner image to the paper P by the secondary transfer roller 20.

By the time this step is reached, in the image forming process started in step S101, the toner image is transferred to the intermediate transfer belt 16 by the primary transfer roller 19, and is transferred to the secondary transfer roller 20 by the intermediate transfer belt 16. It is assumed that it is being sent to.

In step S109, the feeding unit 102 feeds the paper P on which the toner image is transferred to the fixing device 34. In addition, the image forming unit 104 executes the fixing process in the fixing device 34.

In step S110, the feeding unit 102 discharges the paper P on which the toner image is fixed in the fixing device 34 to the outside of the printer 100. After that, the printing process ends.

(About printing process when image retransmission occurs)
Next, a flow when a predetermined resist restart time elapses in a state where the tip of the paper P does not reach the resist sensor 31 will be described.

In step S111, the image forming unit 104 stops image drawing. The feeding unit 102 continues to convey the paper P. On the other hand, the feeding unit 102 interrupts the subsequent feeding of the paper P.

In step S112, the detection unit 103 determines whether or not the tip of the paper P to be fed has reached the resist sensor 31 in the same manner as in step S105. The flow of FIG. 4 proceeds to step S114 when it is determined that the tip of the paper P has reached the resist sensor 31, and proceeds to step S113 when it is not determined.

In step S113, the detection unit 103 determines whether or not a predetermined jam detection time has elapsed. It is assumed that the predetermined jam detection time is set in advance and stored in a storage unit or the like. That is, in this step, it is determined whether or not the predetermined jam detection time has elapsed without the tip of the paper P reaching the resist sensor 31. The flow of FIG. 4 proceeds to step S116 when it is determined that the predetermined jam detection time has elapsed, and returns to step S112 when it is not determined.

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

In step S115, the feeding unit 102 restarts the resist in the same manner as in step S107. However, unlike step S107, the feeding unit 102 does not start the subsequent feeding process for the paper P in this step. After that, the flow of FIG. 4 proceeds to step S108, and secondary transfer, fixing, and ejection of the paper P for which the feeding has been resumed are performed.

After it is determined in step S106 that the predetermined resist elapsed time has elapsed, image reshaping (redrawing) and ejection are performed in the flow of step S111, step S114, step S115, step S108, step S109, and step S110. The operation is called image retransmission.

(About printing process when jam occurs)
Here, a case where a predetermined jam detection time has elapsed without the tip of the paper P reaching the resist 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 the jam is not fed. When it is determined that the non-paper feed jam has occurred, the notification unit 105 generates display information for notifying the user that the non-paper feed jam has occurred. The generated display information is supplied to the operation panel 63. The operation panel 63 displays that a non-paper 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. The user may be notified by blinking the display screen or changing the color of the display screen.

In step S117, printing is interrupted. After that, the flow of FIG. 4 ends.

Here, an example of the flow of image formation relating to the subsequent paper P (hereinafter referred to as the succeeding paper) of the paper P in which the image retransmission has occurred (hereinafter referred to as the image retransmission generating paper) will be described. FIG. 5 is a flowchart showing an example of the flow of image formation regarding the subsequent paper of the image retransmission generation paper when the image retransmission occurs in the flow of FIG.

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

In step S202, the detection unit 103 starts measuring the time by the paper spacing timer. Here, the paper spacing timer is set, for example, at the time required to convey the maximum paper length that can be conveyed.

In step S203, the detection unit 103 determines whether or not the paper spacing timer has timed out. That is, this step can be expressed as a step of determining whether or not there is a sufficient gap between the paper P on which the image retransmission has occurred (the paper on which the image retransmission has occurred) and the subsequent paper P (subsequent paper). .. The flow of FIG. 5 repeats the process until it is determined that the paper spacing timer has timed out, and proceeds to step S204 when it is determined that the paper spacing timer has timed out.

In step S204, the feeding unit 102 restarts the conveying of the succeeding paper.

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

FIG. 6 is for explaining a case where the image retransmission generation paper and the subsequent paper overlap each other due to the delay in transporting the image retransmission generation paper when the image retransmission occurs in the image retransmission flow of FIG. It is a figure. As described with reference to FIG. 4, the printing process when image retransmission occurs is a printing process when a predetermined resist restart time elapses without the tip of the paper P reaching the resist sensor 31. When the transfer of the image retransmission generation paper is delayed in this way, as shown in the upper part of FIG. 6, the image retransmission generation paper and the subsequent paper may overlap. If the image retransmission generation paper and the succeeding paper are conveyed in an overlapping manner, the resist sensor 31 will not be turned off indefinitely, and thus it will be determined as a jam. Further, if the resist roller pair 32 and the paper feed roller 47 are driven in a state where the image retransmission generation paper and the subsequent paper are overlapped with each other, a paper jam may occur.

Under such circumstances, as described above, the printer 100 according to the present embodiment can stop the transport of only the succeeding paper when the image retransmission occurs. That is, according to the technique according to the present embodiment, as shown in the lower part of FIG. 6, there is an effect that the space between the image retransmission generation paper and the succeeding paper can be secured. Further, according to the control for securing the paper spacing according to the present embodiment, there is an effect that the paper overlap can be eliminated. In other words, it has the effect of being able to discharge without jam.

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

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

After that, since the image is retransmitted with respect to the paper 2, the paper feeding of the paper 3 is temporarily suspended. As described above, the paper 3 is re-conveyed after the inter-paper timer times out. The paper spacing between the paper 2 and the paper 3 when the feeding of the paper 3 is resumed is the gap B.

After the image retransmission occurs in this way, the feeding unit 102 sets the interval B as the paper interval for the subsequent paper 4 of the paper 3. That is, when the image retransmission occurs, the feeding unit 102 sets the paper interval (interval B) between the image retransmission generating paper and the subsequent paper as the subsequent paper spacing.

If paper with a large slippage is loaded, the transfer of subsequent paper may be delayed. However, according to this configuration, it is possible to secure a paper feed interval according to the degree of slippage of the paper even for the succeeding paper. That is, according to the technique according to the present embodiment, there is an effect that it is possible to prevent jam due to the narrowing of the paper feed interval after the occurrence of image retransmission.

In addition, after the paper spacing is changed (for example, enlarged) due to the occurrence of image retransmission, further image retransmission may occur. In this case, the notification unit 105 generates display information for notifying the user that image retransmission has occurred due to a delay in transporting the paper in a state where the paper feeding interval is extended, for example, in the same manner as in step S117. According to this configuration, since it is possible to notify the user that a lot of slippage has occurred, 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 subsequent paper feeding is restarted when the paper-to-paper timer times out has been described as an example, but the present invention is not limited to this. For example, the feeding of the succeeding paper may be restarted at the timing when the rear end of the image retransmission generation paper passes through the resist sensor 31 arranged on the transport path on the downstream side of the front end of the succeeding paper. The timing at which the rear end of the image retransmission generating paper passes through the resist sensor 31 is the timing at which the resist sensor 31 is turned off after the front end of the image retransmission generating paper reaches the resist sensor 31 and the resist sensor 31 is turned on. Is. According to the technique according to the above-described embodiment, when the image retransmission occurs, the feeding of the image retransmission generating paper is continued, while the feeding of the succeeding paper is interrupted, so that the image retransmission generating paper and the succeeding paper are interrupted. It is possible to prevent the paper from being transported in an overlapping manner. That is, according to the technique according to the above-described embodiment, it is possible to avoid a situation in which the resist sensor 31 is not turned off indefinitely. Therefore, the feed start timing of the succeeding paper is determined based on the on / off of the resist sensor 31. You can also. By restarting the transfer of the succeeding paper at the timing when the sensor OFF on the transfer path is detected, there is an effect that the occurrence of jam can be prevented and the decrease in productivity can be suppressed.

In the above-described embodiment, the case where the sheet-shaped object to be transported 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 technique according to the above-described embodiment can also be applied to an object to be transported having another shape in the form of a sheet and an apparatus for performing other operations of image formation. For example, according to the technique according to the above-described embodiment, it is possible to secure a transport interval in a device such as a corrugated cardboard box in which a predetermined operation such as labeling is performed on a non-sheet-shaped object to be transported.

The image forming program executed by the printer 100 (image forming apparatus) of the present embodiment is provided by being incorporated in a ROM or the like in advance.

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 is a CD-ROM, a flexible disk (FD), a CD-R, or a DVD (Digital Versaille). It may be configured to be recorded and provided on a recording medium that can be read by a computer such as a Disc).

Further, the image forming program executed by the printer 100 (image forming apparatus) of the present embodiment is stored on a computer connected to a network such as the Internet, and is configured to be provided by downloading via the network. Is also good. Further, the image forming program executed by the printer 100 (image forming apparatus) of the present 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 the present embodiment has a module configuration including the above-mentioned parts (acquisition unit 101, feeding unit 102, detection unit 103, image forming unit 104, and notification unit 105). As the actual hardware, when the CPU (processor) reads the image forming program from the ROM and executes it, each of the above parts is loaded on the main memory, and the acquisition unit 101, the feeding unit 102, and the detection unit are detected. A unit 103, an image forming unit 104, and a notification unit 105 are generated on the main storage device.

In the above embodiment, the image forming apparatus of the present invention will be described with reference to an example in which the image forming apparatus of the present invention is applied to a multifunction device having at least two functions of a copy function, a printer function, a scanner function and a facsimile function. It can be applied to any image forming apparatus such as a printer, a scanner apparatus, and a facsimile apparatus.

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)
31 Resist sensor 32 Resist roller vs. 34 Fixing device 34a Fixing roller 34b Pressurizing roller 46 Bottom plate 47 Paper feed roller 57 UART
58 CPU
59 ROM
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 / humidity sensor 100 Printer (image forming device)
101 Acquisition unit 102 Feeding unit 103 Detection unit 104 Image forming unit 105 Notification unit P paper

Japanese Unexamined Patent Publication No. 2003-306254

Claims (7)

A feeding unit that continuously feeds each of the plurality of sheets at predetermined sheet intervals from a sheet storage unit that stores a plurality of sheets, and a feeding unit.
A detection unit that detects the presence or absence of the fed sheet on the transport path of the fed sheet, and
An image forming portion for forming an image on the image carrier and transferring the image formed on the image carrier to the sheet is provided.
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 the feeding of the first sheet and stops the feeding of the 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 reshapes the image formed on the first sheet into the image carrier, and then reshapes the image.
The feeding unit resumes feeding the second sheet.
Image forming device. When the feeding of the second sheet is resumed, the feeding unit sets the predetermined sheet spacing in the subsequent feeding to the sheet spacing between the first sheet and the second sheet. The image forming apparatus according to claim 1, wherein the image forming apparatus is modified. When the detection unit detects the tip of the first sheet after the feeding of the second sheet is stopped, the image forming unit reshapes the image formed on the first sheet into the image carrier. ,
When the detection unit detects the rear end of the first sheet after the feeding of the second sheet is stopped, the feeding unit restarts the feeding of the second sheet.
The image forming apparatus according to claim 1 or 2. The detection unit measures the elapsed time from the stop of feeding of the second sheet, and measures the elapsed time.
When the rear end of the first sheet is detected, the elapsed time exceeds the time required to convey the maximum paper length that can be conveyed by the image forming apparatus.
The image forming apparatus according to claim 3. With respect to the third sheet fed after resuming the feeding of the second sheet, when the detection unit does not detect within a predetermined time after the image is formed on the image carrier, the predetermined sheet interval is expanded. The image forming apparatus according to any one of claims 1 to 4, further comprising a notification unit for generating display information for presenting to the user that an image retransmission has occurred in the state of being. A step of continuously feeding each of the plurality of sheets from a sheet storage unit for storing a plurality of sheets at predetermined sheet intervals, and a step of continuously feeding the plurality of sheets.
A step of detecting the presence or absence of the fed sheet on the transport path of the fed sheet, and
Including the step of forming an image on the 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 feeding step includes a step of 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,
The step of forming the image includes a step of reforming the image formed on the first sheet into the image carrier.
The feeding step includes a step of restarting 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 for storing a plurality of sheets at predetermined sheet intervals, and a step of continuously feeding the plurality of sheets.
A step of detecting the presence or absence of the fed sheet on the transport path of the fed sheet, and
In a program in which a computer mounted on an image forming apparatus executes a step of forming an image on an image carrier and transferring the image formed on the image carrier onto the sheet.
When the fed first sheet is not detected within a predetermined time after the image is formed on the image carrier.
The feeding step includes a step of 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,
The step of forming the image includes a step of reforming the image formed on the first sheet into the image carrier.
The feeding step includes a step of restarting feeding of the second sheet.
program.

Images