JP2007314334A - Image forming system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform control causing no damage of sheets at appropriate speed increasing timing, even when sheet carrying speed is changed to high speed even in an image forming device having no reading scanning device in an image forming system comprising a paper feeding tray and the image forming device. <P>SOLUTION: This image forming system comprising the image forming device 101 and a plurality of sheet feeding devices 113, 125, 126 is provided with a communication means 301 exchanging communications between the image forming device 101 and the sheet feeding devices 113, 125, 126; a first detection means 108 detecting sheets carried by the image forming device 101; sheet carrying means 103, 104 for the sheet feeding devices 113, 125, 126; a drive means for the carrying means 103 104; and a control means 202 for the drive means. When a sheet which is being carried to inside of the image forming device 101 is detected by the first detection means 108 at the time of print processing, the image forming device 101 instructs the control means for the plurality of sheet feeding devices 113, 125, 126 connected via the communication means 301 to simultaneously change the drive speed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming system including an image forming apparatus and a sheet feeding apparatus.

  2. Description of the Related Art Conventionally, as a method for controlling sheet feeding timing in a multi-stage sheet feeding apparatus that feeds sheets to an image forming apparatus, there is a method of controlling by using a predetermined timing of image forming processing as a trigger. For example, in Patent Document 1, in a configuration in which a multi-stage sheet feeding tray is arranged in an electronic copying machine having a scanning device, a sheet is sent out early from a sheet feeding tray at a remote position in response to an operation start signal of the scanning device. It is operating.

  In addition, control is performed so that the sheet is conveyed at a speed higher than the normal speed after a predetermined time has elapsed since the sheet is sent out from the sheet feed tray, and the next sheet is fed according to a preset timing for the sheet feed tray. The operation timing of the apparatus is controlled.

By performing the control as described above, the number of copies per unit time can be maintained constant regardless of the paper feed tray.
JP-A-5-297657

  However, for example, the paper conveyance method described in Patent Document 1 is limited to an electronic copying machine having a scanning device. In recent years, the number of systems in which a user transmits data from a host computer and performs a printing operation also increases in a copying apparatus, and timing control in such a case has not been supported.

  In addition, when the feeding speed from a feeding tray at a distant position is increased in a multi-stage feeding device, the sheet is slackened when the timing for changing the sheet conveying speed to be different at each stage, or the sheet is Pulling force acts. Therefore, if the amount of deviation is large, the sheet may be damaged or jammed.

  In order to solve the above problems, in the present invention, in an image forming apparatus having a plurality of stages of paper feed trays, an image forming system that performs control that does not damage a sheet even when the sheet conveyance speed after feeding is changed to a high speed. The purpose is to provide. It is another object of the present invention to provide an image forming system that performs control at an optimal speed increase timing even in an image forming apparatus that does not have a reading scanning device.

  In order to achieve the above object, the present invention has the following configuration.

An image forming apparatus for performing a printing process for fixing a developer on a sheet;
In the image forming system comprising a plurality of sheet feeding devices that can be connected to the image forming device and feed sheets to the image forming device.
Communication means for communicating data between the image forming apparatus and the plurality of sheet feeding apparatuses;
First detection means for detecting a sheet that the image forming apparatus is conveying in the apparatus;
A sheet conveying means for conveying the sheet by the sheet feeding device;
A driving means capable of changing the speed for driving the sheet conveying means;
Comprising control means for controlling the drive means;
When the image forming apparatus detects a sheet being conveyed into the apparatus by the first detection unit during print processing, the control unit of the plurality of sheet feeding apparatuses connected via the communication unit An image forming system characterized in that instructions for changing the drive speed of the drive means are issued simultaneously.

  As described above, according to the present invention, an instruction for changing the sheet conveyance speed is supported in an image forming apparatus to which a plurality of sheet feeding devices can be connected. Therefore, when a sheet is fed from a sheet feeding device far from the image forming apparatus main body, or even when a job for switching the sheet feeding position is received, the sheet conveyance speed is increased to shorten the sheet interval. It becomes possible.

  In addition, since the sheet feeding timing is controlled using the sensor in the image forming apparatus main body, even in the configuration of the image forming apparatus that does not have the scanning device, it is possible to perform the speed-up process of the sheet that has been fed. For this reason, as soon as the transfer of the image to one sheet is completed, the transfer of the image to the next sheet becomes possible, and the number of prints per unit time is kept constant regardless of the position of the sheet feeding device that feeds the sheet. Can be maintained.

  Also, when accelerating the sheet conveyance, it is possible to prevent damage to the sheet by sending commands to multiple stages of paper feeding devices at the same time, or sending commands from the far side of the image forming device. Is possible.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

  An image forming system including an image forming apparatus and a sheet feeding apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of an image forming apparatus and a sheet feeding apparatus. 101 is a main body of the image forming apparatus, and 102 is a paper feeding cassette on which a user sets sheets.

  When the power of the image forming apparatus 101 is turned on, the driving unit M1 (not shown) is driven to raise the paper bundle set in the paper feed cassette. When the paper bundle upper limit detection sensor 107 that detects the upper limit of the paper bundle height detects the paper bundle, the driving unit stops the raising operation. The stop position of the ascending operation is a predetermined height position where the sheet feeding roller 105 contacts the uppermost surface of the sheet bundle and conveys the sheet to the conveyance path. Reference numerals 103 and 104 denote conveying rollers which are rotated in the same direction to prevent double feeding of sheets.

  The sheet feeding roller 105 has a structure that moves up and down. Normally, when the sheet feeding operation starts after waiting at the upper limit position, the sheet feeding roller 105 performs a lowering operation to send the sheet to the conveyance path. When the sheet reaches the conveying rollers 103 and 104, the sheet feeding roller is retracted to the upper limit standby position. Thereafter, the conveying roller conveys the sheet.

  When receiving data from a host computer (not shown) or the like, the image forming apparatus converts the data into data for print processing and starts an image forming operation. When the image forming operation is started, the sheet is carried to the conveyance path by the paper feed roller, and the developed toner image is transferred and fixed by the fixing device 109.

  A sheet detection sensor 108 (conveyance path detection sensor) is arranged in the middle of the conveyance path from the paper feed cassette to the fixing device. From the timing when the conveyance path detection sensor detects the sheet, image forming process processing and the next page are performed. Paper feeding or the like is performed. The sheet fixed by the fixing device is then discharged to the discharge tray 110 and the printing process is completed.

  A sensor 106 is a sensor that detects the presence / absence of a sheet in the sheet feed tray and constantly monitors the sheet presence / absence status of the sheet feed cassette. Reference numeral 111 denotes a second conveyance path, which is a conveyance path for conveying a sheet conveyed from an optionally connected sheet feeding apparatus. A connector 112 is connected to the sheet feeding device, performs communication processing with the sheet feeding device, and supplies power.

  A sheet feeding apparatus 113 has the same structure as each sheet feeding section of the image forming apparatus. 114 is a sheet feeding cassette, 115 and 116 are conveying rollers, 117 is a sheet presence / absence detection sensor, 118 is a sheet bundle upper limit detection sensor, 119 is a sheet feeding roller, and 120 is a lower sheet feeding apparatus and a higher sheet feeding apparatus. It is the 2nd conveyance path which conveys a sheet | seat to an apparatus.

  121 is a second conveyance roller for drawing a sheet conveyed from a lower apparatus into the apparatus and conveying it to the upper apparatus, and 122 is a sheet cassette 114 or detecting a sheet conveyed from the lower apparatus within the apparatus. It is a conveyance detection sensor for doing. Reference numeral 123 denotes a connector for performing communication and power supply to the lower sheet feeding apparatus, and 124 is a connector for connection to the image forming apparatus main body or the upper sheet feeding apparatus. Furthermore, 125 and 126 are the same option sheet feeding devices as 113.

  FIG. 2 is a configuration diagram illustrating an electric control unit of the sheet feeding apparatus. The sheet feeding device 113 will be described as an example.

  Reference numeral 201 denotes a control controller board on which various control circuit components are mounted. A CPU 202 performs signal control of various circuits to be connected. Reference numeral 203 denotes a communication control connector for the host apparatus 101, which performs communication processing in accordance with a predetermined communication specification via the control circuit 210. Reference numeral 204 denotes a connector for controlling communication with the lower level device 125, and performs communication processing with the lower level device via the control circuit 211.

  A motor drive circuit 205 controls the motor M1. The motor M1 used here performs the ascending operation of the paper bundle set in the paper feed cassette 114, but it can be constituted by a DC motor or a pulse motor regardless of the type of motor. 206 also drives a motor M2 by a motor drive circuit. The motor M2 is used as a driving source for various rollers (115, 116, 119, 121) in the sheet feeding apparatus.

  Reference numeral 207 denotes a drive circuit for the solenoid SL1. The solenoid plays a role of controlling the vertical movement switching of the paper feed roller 119, and when the solenoid is driven, the paper feed roller descends and comes into contact with the paper bundle. The paper feed mechanism may be configured using an electromagnetic clutch instead of a solenoid.

  Reference numeral 208 denotes an input circuit of the switch SW1, and SW1 is a switch for detecting the size of the sheet set by the user in the paper feed cassette 114. A reset circuit 209 monitors the voltage supplied to the circuit, and resets the CPU when a voltage below a certain level is detected. Reference numerals 212, 213, and 214 denote sensor input circuits of SNS1, SNS2, and SNS3, respectively, and optical sensors are often used as the sensors.

  FIG. 3 is a block diagram illustrating communication control of the image forming apparatus 101 and sheet feeding apparatuses 113, 125, and 126. Reference numeral 301 denotes a controller of the image forming apparatus main body, and reference numerals 302, 303, and 304 denote controllers of the sheet feeding apparatus. The controllers 301 to 304 are connected by communication control signal lines as shown in the figure.

  In the example shown in the figure, the configuration is a serial communication line for clock synchronization control that is generally used. A command signal (CMD) transmitted from the image forming apparatus in synchronization with the clock signal (CLK) and a response signal (STS) returned from the sheet feeding apparatus are used. In general communication processing specifications, the initial communication between the image forming apparatus main body and the sheet feeding apparatus performs a process of assigning an ID number to each connected sheet feeding apparatus. Thereafter, the image forming apparatus transmits a command assigned with an ID number to the sheet feeding apparatus.

  4 to 8 are flowcharts showing sequences of the image forming apparatus and the sheet feeding apparatus.

  FIG. 4 shows an initial sequence of the image forming apparatus. In step S401, the image forming apparatus performs initialization. First, the CPU 202 sets various registers of the internal program and initializes variables, and performs initial drive operations of motors, solenoids, sensors, and the like to check whether a failure has occurred. If no abnormality or the like has occurred in the initialization, the process proceeds to S402 to perform connection confirmation processing of optional devices including the sheet feeding device.

  A variety of detection methods have been devised for connection confirmation processing. For example, a connection confirmation code is sent to the optional device, and if there is no response for a predetermined time, it is determined that there is no connection device, and reply data is received. In this case, the connection device, number of units, and configuration are determined according to the content.

  In S403, in the initialization process completion confirmation process, when the completion is detected, the process proceeds to S404 and the standby process is performed. Standby processing monitors changes in the status of each unit, and performs output processing to the display panel and job reception check from the host computer. In S405, when job reception is detected in the job reception waiting process, the process jumps to the print processing routine.

  FIG. 5 is a speed increasing instruction routine to the print processing and sheet feeding apparatus. In step S501, job reception confirmation processing is performed. When job reception is detected, the process proceeds to step S502 to start an image forming processing sequence.

  The job data sent from the host computer is analyzed to specify the paper feed tray and sheet type, etc., and the received data is converted to electronic data (latent image), and the optical unit, transfer unit, and fixing unit Start signal processing. In step S503, a sheet feeding start instruction code is transmitted to the sheet feeding apparatus in accordance with the timing of the image forming process, and the process proceeds to step S504, where jump processing is performed to a speed increase instruction sequence to the sheet feeding apparatus.

  FIG. 6 shows a speed increase instruction sequence. S601 is a monitoring process of the conveyance path detection sensor 108, and waits for whether the conveyance path detection sensor detects a sheet after transmitting a paper feed instruction code. If a sheet is not detected for a predetermined time after a paper feed instruction, it is determined that a jam has occurred. When the sheet is detected in S601, the process proceeds to S602, where broadcast transmission (acceleration processing instruction transmission) is set, and the transmission code is set to be transmitted to all connected sheet feeding apparatuses.

  In step S603, a speed increase instruction code is transmitted. The sheet feeding apparatus that has received the speed increase instruction code performs signal processing for the CPU 202 to perform a speed increase process of the motor M2 to the drive circuit 206 in order to increase the speed of the sheet conveying means. Thereafter, the process proceeds to S604, where the conveyance detection sensor of the sheet feeding device is checked.

  FIG. 8 is a sequence for instructing a deceleration process and a stop process of the sheet conveying means of the sheet feeding apparatus which has issued the speed increase instruction in FIG. In step S <b> 801, a sequence for checking whether or not any of the connected sheet feeding apparatuses has completed sheet conveyance. The sheet conveyance completion timing is set at a timing when the conveyance detection sensor 122 detects the trailing edge of the sheet. In step S802, the apparatus that has completed the conveyance of the sheet is determined, and the apparatus that has completed the conveyance among a plurality of connected sheet feeding apparatuses is determined.

  After that, the process proceeds to S803, where the next page job reception history confirmation process is performed. If the next page job has been received, the process advances to step S804, and the CPU 202 performs a deceleration instruction process for the sheet conveying unit. If the next page job has not been received in step S803, the process advances to step S805 to stop the sheet conveying unit.

  As described above, according to the control of the image forming apparatus and the sheet feeding apparatus of the present invention, when the image forming process is started and the optional sheet feeding apparatus is designated to feed, the fed sheet is conveyed. Is done. When the conveyance detection sensor of the image forming apparatus detects the leading edge or the trailing edge of the sheet, the image forming apparatus simultaneously instructs the sheet feeding apparatus to increase the conveyance speed (transmit a broadcast command). Thereafter, all the connected sheet feeding devices simultaneously perform speed increase control, so that the next page sheet is conveyed to the image forming apparatus at a higher speed than usual and without damaging the sheet. This speed-up process instruction (broadcast command transmission) is an instruction for simultaneously accelerating a plurality of connected paper feeding apparatuses, and an instruction is issued from the image forming apparatus to a plurality of paper feeding apparatuses at the same timing. Do. The timing for increasing the speed of each sheet feeding device may be substantially the same timing.

  The image forming apparatus constantly monitors the sheet conveyance status of the option sheet feeding apparatus, and gives an instruction to perform a deceleration process from the apparatus that has completed the sheet conveyance. As a result, it is possible to shorten the sheet interval between the page and the previous page, and it is possible to prevent a decrease in the number of print processed sheets per unit time.

  A second embodiment will be described.

  In the image forming system having the configuration of the first embodiment, the sequence processing of FIG. 7 is performed as an alternative example of the speed increase instruction command transmission sequence of FIG.

  S701 is a routine for monitoring ON (sheet leading edge detection) of the conveyance sensor 122a of an optional sheet feeding apparatus connected to the image forming apparatus and closest to the image forming apparatus. When the conveyance sensor detects ON of the preceding page, the process proceeds to S702, and a monitoring routine for detecting conveyance sheet OFF (detection of the trailing edge of the sheet) of the preceding page is executed.

  When the conveyance sensor OFF is detected, the process proceeds to S703, where broadcast transmission setting is performed. Thereafter, a speed increase instruction command is transmitted in S704. In S705, in the conveyance sensor ON monitoring routine for the page, when the leading edge of the sheet on the page is detected, the process proceeds to S706, where a deceleration instruction command is transmitted with the broadcast setting.

  As described above, the image forming apparatus according to the present exemplary embodiment monitors a sensor installed in the conveyance path of the sheet feeding apparatus located closest to the sheet feeding apparatus connected to the image forming apparatus. When it is detected that the trailing edge of the sheet fed from the sheet feeding device has passed the sensor, an instruction to increase the speed is given to all the sheet feeding devices, so that the sheet is conveyed at a high speed and the preceding paper The paper interval can be reduced.

  Further, when the sensor detects the leading edge of the sheet that has been accelerated and conveyed at a high speed, the sensor decelerates and returns to the normal speed, so that it is possible to prevent a jam that occurs due to excessively narrowing of the sheet interval.

1 is an overall view of an image forming system according to an embodiment of the present invention. FIG. 6 is a block diagram illustrating an electrical control unit of the sheet feeding apparatus. It is a block diagram which shows the communication structure of an image forming system. 5 is a flowchart illustrating initialization processing of the image forming apparatus. 6 is a flowchart illustrating a printing process of the image forming apparatus and a speed increase instruction sequence to the sheet feeding apparatus. 6 is a flowchart illustrating an acceleration instruction sequence and a deceleration instruction sequence to the sheet feeding device. 10 is a flowchart illustrating a speed increase instruction and a speed decrease instruction sequence to a sheet feeding apparatus according to a second embodiment. 6 is a flowchart illustrating a deceleration instruction sequence and a stop instruction sequence to a sheet feeding apparatus.

Explanation of symbols

90 Process cartridge 91 Photosensitive drum 92 Transfer roller 93 Conveying roller pair 101 Image forming apparatus 102 Paper feed cassette 103, 104 Conveying roller (corresponding to sheet conveying means)
108 Conveyance path detection sensor (corresponding to the first detection means)
111 Second conveyance path 113, 125, 126 Sheet feeding device 120 Second conveyance path 121 Second conveyance roller 122 Conveyance detection sensor (corresponding to second detection means)
201 Sheet feeding device controller 202 CPU (corresponding to control means)
301 Image forming apparatus controller (corresponding to communication means)
302, 303, 304 Sheet feeding device controller (corresponding to communication means)
M1 paper bundle raising motor M2 transport path driving motor (corresponding to driving means)
SL1 Solenoid SNS1, SNS2, SNS3 Optical sensor

Claims (4)

An image forming apparatus for performing a printing process for fixing a developer on a sheet;
In the image forming system comprising a plurality of sheet feeding devices that can be connected to the image forming device and feed sheets to the image forming device.
Communication means for communicating data between the image forming apparatus and the plurality of sheet feeding apparatuses;
First detection means for detecting a sheet that the image forming apparatus is conveying in the apparatus;
A sheet conveying means for conveying the sheet by the sheet feeding device;
A driving means capable of changing the speed for driving the sheet conveying means;
Comprising control means for controlling the drive means;
When the image forming apparatus detects a sheet being conveyed into the apparatus by the first detection unit during print processing, the control unit of the plurality of sheet feeding apparatuses connected via the communication unit An image forming system characterized in that instructions for changing the drive speed of the drive means are issued simultaneously.   The communication means has a common bus line for connecting the image forming apparatus and the plurality of sheet feeding apparatuses, and is capable of receiving signals transmitted from the image forming apparatus by all the sheet feeding apparatuses. 2. The image according to claim 1, wherein the image forming apparatus is a unit capable of transmitting data to all the sheet feeding apparatuses simultaneously by a code of data transmitted from the image forming apparatus to the sheet feeding apparatus. Forming system. A different ID is assigned to each of the plurality of sheet feeding apparatuses, and a sheet feeding apparatus that receives data transmitted by the image forming apparatus is designated by the ID assigned to data transmitted by the image forming apparatus.
The image forming apparatus issues a drive instruction to the plurality of sheet feeding apparatuses while shifting the time, and issues a drive instruction for the sheet conveying unit in the order of the sheet feeding apparatuses to which the sheet is conveyed. Item 3. The image forming system according to Item 2. Among the plurality of sheet feeding apparatuses, comprising a second detection means for detecting a sheet conveyed from a lower-level sheet feeding apparatus or from the image forming apparatus,
The lower sheet feeding apparatus transmits detection information of the second detection unit to the image forming apparatus through the communication unit, and the image forming apparatus transmits control information to the plurality of sheet feeding apparatuses. The image forming system according to any one of claims 1 to 3, wherein an instruction to change the driving speed of the driving unit is issued simultaneously or at different times.

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