JP2008213974A - Printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of irregularity in paper feeding due to the deviation of carrying start positions of paper. <P>SOLUTION: A plurality of option feeders 12a to 12d are mounted on printing device body 11. A control portion 23 of the printing device body 11 transmits a paper-feeding command to a control portion 51 of the option feeders 12a, 12d. When receiving the paper-feeding command, the control portion 51 of the option feeders 12a to 12d starts carrying of the paper and counting by a timer. The paper is temporary stopped at a position of a carrying sensor 61, and the carrying of the paper is restarted when the timer reaches predetermined time. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printing apparatus and a printing method.

  A tandem type printing apparatus has a plurality of OPC (Organic Photo Conductor) drums corresponding to each color arranged side by side, forms a single color toner image on each drum, and transfers these single color toner images to an intermediate transfer belt. To a printing apparatus for secondary transfer onto a sheet. The tandem type printing apparatus has an advantage that the image forming time is shortened because the toner images of the respective colors are simultaneously formed using a plurality of OPC drums corresponding to the respective colors.

  In such a tandem type printing apparatus, the timing at which an image is formed on the intermediate transfer belt and the timing at which the paper is conveyed to the position of the intermediate transfer belt are synchronized, and the image formed on the intermediate transfer belt is It is necessary to control so that it is transferred to a predetermined position. For this reason, when an optional feeder (optional device) is provided in the tandem type printing apparatus, the timing at which the sheet is conveyed to the secondary transfer position and the timing at which the image is formed are synchronized.

  In such an option feeder, a plurality of sheets are stored as a stack of sheets. In some cases, the leading edge of the paper used for the next paper feed slightly protrudes from the paper bundle due to friction in the previous paper feed. In such a case, there is a difference between the paper transport start position in the previous paper feed and the paper transport start position in the next paper feed, and the paper feed timing varies. For this reason, when an optional feeder is installed in a tandem-type printing device, the timing at which paper is sent from the optional feeder to the main unit even if a paper feed command is sent from the main unit printing device to the optional feeder at the same timing In some cases, the sheet is not conveyed to the registration roller at a scheduled sheet feeding timing, and a retry may occur.

Therefore, in order to solve such a problem of variation in paper feed timing, for example, as disclosed in Patent Document 1, an intermediate sensor is provided in the paper transport path, and the paper is transported quickly at the check timing by the intermediate sensor. It has been proposed to determine whether it is slow or slow and to control whether or not to temporarily stop the conveying roller according to the result.
Japanese Patent Laid-Open No. 2001-213537

  However, in the technique disclosed in Patent Document 1, the feeding speed is controlled by controlling whether or not the conveyance roller is temporarily stopped depending on whether the conveyance state of the paper is early or late. This makes the control complicated because it is necessary to determine the supply timing of the paper.

  SUMMARY An advantage of some aspects of the invention is that it solves the problem of paper feed variation caused by a shift in the paper transport start position in a printing apparatus with simple control.

  In order to solve the above-described problem, a printing apparatus according to the present invention includes a main apparatus that prints on a sheet based on an image signal and an option apparatus that supplies the sheet to the main apparatus. The apparatus includes a transport unit that transports the paper, a transport sensor that detects that the paper has reached a predetermined position, and a control unit that controls the transport unit. Upon receipt of a paper feed command, the conveying means is driven and counting by a timer provided therein is started. Upon reception of a detection signal from the conveyance sensor, driving of the conveying means is stopped, and a predetermined time is set by the timer. The conveying means is driven again after counting.

  Further, in the present invention, the predetermined time includes a time during which the optional device transports the paper from the paper tray to the position of the transport sensor, and a paper feed delay time due to slipping when picking up the paper from the paper tray. A configuration is adopted that is set based on the above.

  In the present invention, a configuration is adopted in which the predetermined time is transferred from the main device to the optional device by communication.

  In the present invention, a configuration is adopted in which the predetermined time is stored in advance in the optional device.

According to the present invention, it is possible to solve the problem caused by the variation in the conveyance of the sheet only by the control for stopping the conveyance of the sheet by the detection signal from the conveyance sensor and the re-transport control of the sheet after the predetermined time is counted by the timer.
Therefore, according to the present invention, in the printing apparatus, it is possible to solve the problem of paper feed variation caused by the shift of the paper transport start position by simple control.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is applied to a printing apparatus represented by a printer apparatus, a copier apparatus, a facsimile apparatus, and the like. Here, a printer apparatus will be described as an example.

  FIG. 1 shows a configuration of a printer apparatus 1 according to the first embodiment of the present invention. In FIG. 1, 11 is a printing apparatus main body, and 12a to 12d are optional feeders.

  The printing apparatus main body 11 receives an image signal from an external personal computer or the like, and forms a color image from the image signal. The printing apparatus main body 11 includes an image processing unit 21, an image forming unit 22, a control unit 23, a paper tray 24, and a paper feed conveyance mechanism including a plurality of rollers and sensors. As the paper feed / conveying mechanism, there are a pickup roller 25 for taking out the paper stored in the paper tray 24, a retard roller 26 for separating and sending out one or more of the paper taken out by the pickup roller 25, It includes various rollers such as a conveyance roller 27 that conveys paper within the apparatus and a registration roller 28 that performs alignment correction, and a sensor for detecting the rotation of each roller and the paper being conveyed. The motor that rotates these rollers is driven under the control of the control unit 23. In addition, detection outputs of various sensors are supplied to the control unit 23. The control unit 23 is connected to an input unit 31 for performing input from various operation keys, a display unit 32 for displaying various states, and a storage unit 33 for storing various programs.

  The option feeders 12 a to 12 d are paper feeders of a type in which a plurality of feeders are stacked in multiple stages in the vertical direction, and are detachable from the printing apparatus main body 11. Here, four option feeders 12a to 12d are shown, but the number of option feeders is not limited to this.

  Each of the option feeders 12a to 12d includes a control unit 51, a paper tray 52, and a paper feeding / conveying mechanism (conveying means) including a plurality of rollers and sensors. The paper feed and transport mechanism includes various rollers such as a pickup roller 53, a retard roller 54, and a transport roller 55, and sensors for detecting rotation of each roller and transported paper. These rollers are driven under the control of the control unit 51, and thereby the paper is conveyed. Further, the detection output of each sensor is sent to the control unit 51.

  Furthermore, in the present embodiment, a conveyance sensor 61 is provided at a predetermined position of the option feeders 12a to 12d, for example, in the vicinity of the paper discharge port 70. The conveyance sensor 61 detects that the sheet has been conveyed to a predetermined position of the option feeders 12a to 12d. As will be described later, in this embodiment, the conveyance sensor 61 is used to prevent variations in the conveyance of the paper.

  The control unit 23 of the printing apparatus main body 11 is provided with a communication interface 34. The control interface 51 of the option feeders 12a to 12d is provided with a communication interface 59. When the option feeders 12a to 12d are attached to the printing apparatus main body 11, the communication interface 34 and the communication interface 59 are connected, and data communication is performed between the control unit 23 of the printing apparatus main body 11 and the control unit 51 of the option feeder 12. Is done.

  When printing is performed by the printer device 1 of the present embodiment, an image signal from an external device is input to the interface 35. This image signal is sent to the image processing unit 21 via the control unit 23. The image processing unit 21 forms Y (yellow), C (cyan), M (magenta), and B (black) color signals from the input image signal. Each color signal is supplied to the exposure devices 36a, 36b, 36c, and 36d of the image forming unit 22, respectively.

  The image forming unit 22 is a tandem image forming unit, and includes four OPC drums 37a, 37b, 37c, and 37d corresponding to colors of Y (yellow), M (magenta), C (cyan), and B (black). , Exposure devices 36a, 36b, 36c, 36d, an intermediate transfer belt 38, drive rollers 39a, 39b around which the intermediate transfer belt 38 is wound, and a fixing roller 40.

  When an image is formed by the image forming unit 22, first, the surfaces of the OPC drums 37a, 37b, 37c, and 37d are uniformly charged. The OPC drums 37a, 37b, 37c, and 37d are scanned and irradiated with laser light by the exposure devices 36a, 36b, 36c, and 36d based on the image signals of the respective colors. When the laser beam is irradiated, the electric charge in the portion irradiated with the laser beam is lost, and latent images are formed on the OPC drums 37a, 37b, 37c, and 37d. Then, the toner of each color is developed on the OPC drums 37a, 37b, 37c, and 37d of each color, and a toner image of each color is formed. This toner image is primarily transferred to the intermediate transfer belt 38.

  On the other hand, among the paper stored in the paper tray 24 of the printing apparatus main body 11 or the paper stored in the paper tray 52 of the option feeders 12a to 12d, the paper in the selected tray is fed as described above. The mechanism is transported to the secondary transfer position of the image forming unit 20 (for example, the position of the registration roller 28). The toner image transferred to the intermediate transfer belt 38 is secondarily transferred onto the fed paper. The toner image transferred onto the paper is fixed by the fixing roller 40 and discharged.

  As described above, in the present embodiment, the conveyance sensor 61 is provided in the vicinity of the sheet discharge port 70 in the option feeders 12a to 12d, and the conveyance sensor 61 is used to prevent variations in sheet conveyance. . FIG. 2 is a functional block diagram of the control unit 51 of the option feeders 12a to 12d when such control is performed.

  In FIG. 2, the control unit 51 includes a command receiving unit 62 that receives a command from the control unit 23 on the printing apparatus main body 11 side, and a paper feeding / conveying mechanism (pickup roller 53, retard roller 54, conveying roller 55, etc.). A transport control unit 63 that controls the sensor, a sensor detection unit 64 that receives a sensor output from the transport sensor 61, and a timer 65. The control unit 51 outputs drive signals for driving the pickup roller 53, the retard roller 54, and the transport roller 55, and this drive signal is sent through the drivers 57a to 57c to the pickup roller 53, the retard roller 54, and the transport roller. 55 is supplied. The conveyance sensor 61 is disposed in the vicinity of the sheet discharge port 70 of the option feeders 12a to 12d.

When the command receiving unit 62 receives a paper feed command, a conveyance command is given to the conveyance control unit 63, and a drive signal for driving the pickup roller 53, the retard roller 54 and the conveyance roller 55 is output. The retard roller 54 and the conveyance roller 55 are driven, and the paper 60 is conveyed. At the same time, when a paper feed command is received, the timer 65 is started, and the timer 65 starts counting for a predetermined time.
The predetermined time counted by the timer 65 differs for each option feeder 12a to 12d. This is because the transport path distances from the option feeders 12a to 12d to the intermediate transfer belt 38 are different. The predetermined time may be transmitted from the control unit 23 of the printing apparatus main body 11 by communication, or a storage unit that stores the predetermined time is installed in the option feeders 12a to 12d. You may acquire from.

  When the paper 60 reaches the position of the conveyance sensor 61, a sensor detection signal is output from the conveyance sensor 61. When the sensor detection unit 64 detects a sensor detection signal from the conveyance sensor 61, a conveyance stop command is given to the conveyance control unit 63. For this reason, the paper 60 is stopped at the position of the conveyance sensor 61.

  When the predetermined time is counted by the timer 65, a conveyance command is given to the conveyance control unit 63. Thereby, the paper 60 is conveyed again.

    For example, in the selected predetermined option feeders 12a to 12d, when the paper conveyance start position in the previous paper feeding is shifted from the paper conveyance start position in the next paper feeding, the paper is detected by the conveyance sensor 61. Deviation occurs in the time to reach On the other hand, in this embodiment, even when there is a deviation in the time for the paper to reach the transport sensor 61, the paper is temporarily stopped at the transport ship 61, and the paper is received at the same time from the reception of the paper feed command. Therefore, the sheet is always supplied to the printing apparatus main body 11 at the same timing. For this reason, it is possible to solve the problem caused by variations in the conveyance of the paper.

In the printing apparatus 1 according to the present embodiment, the sheet is controlled only by the control for stopping the conveyance of the sheet by the detection signal from the conveyance sensor 61 and the sheet re-feeding control after the predetermined time is counted by the timer 65. It is possible to solve the problem caused by the variation in transport.
Therefore, according to the printing apparatus 1 of the present embodiment, it is possible to solve the problem caused by variations in the conveyance of the paper without determining the timing of supplying the paper to the conveyance rollers or the like as in the conventional printing apparatus. That is, it is possible to solve the problem caused by variations in the conveyance of the paper with simple control.

  FIG. 3 is a flowchart showing processing of the control unit 51 of the option feeders 12a to 12d when printing is performed by the printing apparatus according to the first embodiment of the present invention.

  In FIG. 3, when a command for a predetermined time Ta is sent from the control unit 23 on the printing apparatus main body 11 side, the control unit 51 of the option feeders 12a to 12d receives the command for the predetermined time Ta (step S1). This predetermined time Ta is set in the timer (step S2). Then, it is determined whether or not a paper feed command is received (step S3). When the paper feed command is received, the paper feed mechanism (pickup roller 53, retard roller 54, transport roller 55, etc.) is driven to transport the paper (step S4). At the same time, counting by a timer is started (step S5).

  Then, it is determined from the detection output of the conveyance sensor 61 whether or not the sheet has reached the position of the conveyance sensor 61 (step S6). When it is detected that the paper has reached the position of the transport sensor 61, the paper feed transport mechanism is stopped (step S7), and it is determined whether or not the set predetermined time Ta has elapsed (step S8). When the predetermined time Ta has elapsed, the paper feeding / conveying mechanism is re-driven (step S9) and the process returns.

  Thus, in this embodiment, the conveyance sensor 61 is provided in the vicinity of the discharge portions of the option feeders 12a to 12d. At the time of printing, control is performed such that the time from when a paper feed command is sent to the option feeders 12a to 12d until the paper is sent from the paper discharge ports of the option feeders 12a to 12d is controlled.

  Due to such control, the control unit 23 on the printing apparatus main body 11 side has variations in the time from when the paper feed command is transmitted until the paper is sent from the option feeders 12a to 12d to the printing apparatus main body 11 side. Disappear. For this reason, the timing at which the sheet is conveyed to the secondary transfer position of the printing apparatus main body 11 and the timing at which the image is formed by the image forming unit 22 are synchronized, and the image is transferred to the intermediate transfer belt 38 at an appropriate timing. Secondary transfer is possible.

The predetermined time Ta set in the timer is set based on the time during which the paper is transported from the paper tray 52 to the position of the transport sensor 61 in the option feeders 12a to 12d, and further, the pickup roller 53 at the time of picking up the paper. It is preferable to set in consideration of a paper feed delay time due to pick-up failure due to sliding.
By adopting such a configuration, it is possible to suppress poor control due to the predetermined time Ta being too short, and prolonged standby time due to the predetermined time Ta being too long.

  In the above example, in step S1, the predetermined time command Ta sent by communication from the control unit 23 on the printing apparatus main body 11 side is received. This predetermined time is determined for each of the option feeders 12a to 12d. Alternatively, it may be determined in advance and stored in a memory. The predetermined time command Ta may be sent only when the power is turned on or reset, or may be sent every time a paper feed command is issued. Further, the predetermined time Ta may be set according to this time by measuring the waiting time of the sheet when the sheet is picked up from the sheet tray 52 and obtaining the optimum waiting time.

  The embodiment of the present invention has been described above. However, the printing apparatus of the present invention is not limited to the illustrated example described above, and various modifications can be made without departing from the scope of the present invention. It is.

1 is a block diagram illustrating a configuration of a printing apparatus according to an embodiment of the present invention. FIG. 3 is a detailed functional block diagram of an option feeder provided in the printing apparatus according to the embodiment of the present invention. 3 is a flowchart used to describe a printing apparatus according to an embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printer apparatus, 11 ... Printing apparatus main body, 12a-12d ... Option feeder, 21 ... Image processing part, 22 ... Image forming part, 23 ... Control part, 24 ... Paper tray, 25 ... Pickup roller, 26 ... retard roller, 27 ... conveying roller, 28 ... registration roller, 31 ... input unit, 32 ... display unit, 34 ... communication interface, 35 ... interface, 36a to 36d ... exposure Device 38. Intermediate transfer belt 39 a to 39 d Drive roller 40 Fixing roller 51 Control section 52 Paper tray 53 Pick-up roller 54 Retard roller 55 Conveyance roller, 59 ... Communication interface, 60 ... Paper, 61 ... Conveyance sensor, 62 ... Command receiving unit, 63 ... Conveyance control unit, 64 ... Capacitors detection unit, 65 ...... timer, 70 ...... paper discharge port

Claims (4)

In a printing apparatus comprising a main body device that prints on paper based on an image signal and an optional device that supplies the paper to the main body device,
The optional device includes a transport unit that transports the paper, a transport sensor that detects that the paper has reached a predetermined position, and a control unit that controls the transport unit.
The control means includes
Upon receipt of a paper feed command from the main unit, the transport unit is driven and counting by a timer provided by itself is started.
Upon receipt of a detection signal from the transport sensor, the drive of the transport means is stopped,
The printing apparatus, wherein the conveying unit is driven again after a predetermined time is counted by the timer.   The predetermined time is set based on a time during which the optional device transports the paper from the paper tray to the position of the transport sensor and a paper feed delay time due to a pick-up failure due to slipping when picking up the paper from the paper tray. The printing apparatus according to claim 1, wherein the printing apparatus is configured as described above.   The printing apparatus according to claim 1, wherein the predetermined time is transferred from the main body apparatus to the option apparatus by communication. The printing apparatus according to claim 1, wherein the predetermined time is stored in advance in the option device.

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