JP2008036861A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of facilitating changing of a module due to change of a specification and reducing the number of processes in exchange of the modules. <P>SOLUTION: There are the plurality of modules each having an electric circuit and a control circuit. Each module itself operates by receiving a necessary control parameter. Communication between an upper manager 1 for giving the control parameter and a paper supply module 2, an image forming module 3, a conveyance module 4, a fixing module 5, or a paper discharge module 10 is carried out by means of an operation mode signal via a communication line 6. Communication between the modules except the upper manager 1 is carried out by means of a timing signal via timing signal transmission lines 7, 8, 9, 16, 20, 21, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus such as a copying machine or a printer that includes modules in which electric hardware, software, and mechanism are integrated into a module, and the module can be evaluated by the module alone.

  Conventionally, in the design of a copying machine or the like, a module division design for each accessory such as a reader, a printer, and an ADF has been performed for the entire copying machine. However, in the printer, the electrical hardware, software, and mechanism are designed independently, and there has been almost no module design that makes the mechanical, electrical hardware, and software sections the same.

  Actually, even in such a functional module, mechanical module division design has been proposed, but in terms of electric hardware and software, the module has not been divided (for example, see Patent Document 1).

Specifically, for example, considering the printer unit, the electrical hardware is configured so that one CPU controls all functions such as fixing, paper feeding, conveyance, and image formation, and the CPU is divided into the functional units. The printer operation was realized with software that switches control.
JP 2002-171372 A

  As described above, when the electrical hardware is designed to control all the printers with one CPU, the following problems occur.

  1: In a high-speed copying machine having many control circuits such as a motor, there is a problem that it is impossible to control at high speed with only one CPU, such as a low-cost low end.

  2: Even if a failure or the like occurs, it is difficult to estimate and determine the failure location, and it is difficult to repair only the failed portion.

  3: Regarding repair, the repair cost may be high and the repair time may increase.

  4: It is practically impossible to replace only the fixing device in consideration of the environment.

  5: If the in-machine wiring is also under centralized control, the bundled wires will crawl around, making it difficult to take measures such as noise, and increasing costs.

  6: Even if you want to make a small change in the specifications, you cannot easily replace the module, and there is a problem that it becomes difficult to develop a wide variety of products because of the heavy load of changing software and electrical hardware. .

  The present invention has been made paying attention to the above points, and it is an object of the present invention to provide an image forming apparatus that makes it easy to change modules by changing specifications and reduces the number of man-hours for module replacement.

  In order to achieve the above object, an image forming apparatus according to the present invention comprises the following arrangement.

  (1) The module is divided into a plurality of modules, and the module has at least an electric circuit for controlling the module and a control circuit for controlling the electric circuit that can be controlled by a program, and is necessary for the module alone. An image forming apparatus that receives a control parameter and is capable of executing the operation of the module in the image forming apparatus as a single unit, wherein at least one of the plurality of modules is an upper manager, and delivers the control parameter Communication between the upper manager and other modules excluding the upper manager is performed by an operation mode signal (signal that defines the operation mode), and communication between the other modules is performed by a timing signal (operation timing between modules). The image forming apparatus is performed by a signal defining

  (2) The image forming apparatus according to (1), wherein a communication line for the timing signal is provided exclusively between the other modules.

  (3) The image forming apparatus according to (1), wherein the upper manager controls a transmission direction of the timing signal.

  (4) The image formation according to (1), wherein a communication speed between the other modules is equal to or faster than a communication speed between the upper manager and the other modules. apparatus.

  (5) Between the other modules is between two adjacent modules that are driven in accordance with the transport order in which the print medium is transported, and includes a paper feed module, an image forming module, a transport module, and a fixing module. The image forming apparatus according to (1), wherein the combination is at least one of a combination of at least two modules among the two-sided sheet copy switching modules.

  (6) The image forming apparatus according to (1), wherein the module performs communication based on the timing signal only between adjacent modules.

  (7) The operation mode signal includes a signal for verifying that communication satisfying a regulation by the timing signal is performed between the other modules, and a signal of the verification result. The image forming apparatus according to (1), wherein communication is verified by the timing signal in response to an instruction from the upper manager, and the verification result is returned to the upper manager by the operation mode signal.

  (8) The image forming apparatus according to (1), wherein communication between the other modules is performed using two or less signal lines.

  (9) The image forming apparatus according to (1), wherein communication between the other modules is performed at an analog voltage level.

  (10) The operation start signal of the other module is detected by the module directly without passing through the upper manager, and is propagated and operated between the other modules. Image forming apparatus.

  (11) The image forming apparatus according to (1), wherein the timing signal includes at least a start signal and an operation start signal of another module.

  (12) The module has at least one sensor for detecting the print medium, and an activation signal or an operation start is started to an adjacent module to which the print medium is transported based on a timing at which the sensor detects the print medium. The image forming apparatus according to (1), wherein a signal is transmitted.

  According to the present invention, the mechanical, electrical hardware, and software sections are aligned, the interface is unified, and the module operation of the copying machine can be realized by a single module.

  1: The module can be easily changed by changing the specifications.

  2: Since it is not necessary to carry out the software change accompanying the module change in individual modules, the man-hours for module replacement can be reduced.

  3: Since failure diagnosis can be performed for each module, it is easy to specify a failure location, and repair can be realized easily and inexpensively by replacing the module.

  4: Since the control is handled by a distributed CPU, etc., even with a high-speed copying machine, even if an expensive CPU is not used and a common module using a low-speed CPU is used, performance can be secured and the design can be simplified. effective.

  5: The path for exchanging operation mode signals and the path for exchanging timing signals were separated. As a result, an effect that can be standardized by using a general-purpose interface such as an inexpensive CAN (Controller Area Network) is provided for a path for exchanging operation mode signals that does not require high-speed operation.

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

  As a module, a fixing device will be described as an example. The fixing device includes a heat fixing device using a normal halogen heater, an electromagnetic induction heating method fixing device, an on-demand (surf) fixing device, its fixing speed, FCOT (waiting time until the first printing), fixing There are fixing devices with different specifications such as temperature. We propose a module structure that can replace them with a copier.

  Conventionally, since the entire copying machine was designed, it is assumed that the printer operates with predetermined specifications. Information such as the fixing temperature range, fixing speed range, FCOT time, and compatible paper types is based on conventional fixing control. In the part, it did not have in the individual control circuit. However, when the fuser can be replaced, first, the upper manager grasps the overall operating conditions and determines the optimum conditions, so each module operates in each module to obtain the operating condition information for each module. It becomes necessary to request and extract condition information.

  Upon receiving the request, the fixing device as a module (hereinafter referred to as a fixing module) transmits data such as the fixing device type, temperature control temperature range, fixable paper type information, and fixing speed information to the upper module. To work.

  Of course, after the power is turned on, the controller dedicated to the module initializes the module, transmits the data, and receives the optimum operating condition information of the image forming apparatus determined by the upper manager from the upper module. Then, known start-up control of the fixing device is performed in accordance with the conditions. Then, when the preparation for fixing control is OK, the status information is transmitted to the upper manager, and a standby state is entered.

  Next, the upper manager receives copy start key pressing information from the key control module. Then, the copy conditions when the key is pressed (the number of copies, color or black and white, reduction, enlargement, special paper, double-sided, paper type, etc.) and common information on pressing the start key are transmitted as control parameters to all modules.

  Each module performs the following operations so that the control of each module can be executed perfectly when a print medium such as paper (hereinafter referred to as paper) is transported based on the information transmitted as control parameters. do. That is, based on the information, a status indicating that each module can be set in the operation start state and capable of actual copying is transmitted to the upper manager.

  Taking the fixing module as an example, for example, in the case of thick paper, the conveyance speed is set to be halved and the fixing temperature is increased as compared with the case of normal paper in accordance with necessary copying conditions.

  When the rotation speed of the motor and the fixing temperature reach the target values, the fixing module transmits ready status information to the upper manager. Even when different fixing controls are used in this way, by combining necessary interface information, it becomes possible to easily replace the modules and change the configuration of the copying machine.

  As described above, the conditions include the fixing device type, temperature control temperature range, fixable paper type information, and fixing speed information as specific to the fixing device. Also, information common to the entire copying machine and printer includes copy conditions (number of copies, color or black and white, reduction, enlargement, special paper, double-sided, paper type, etc.).

  Next, based on an actual configuration diagram, the operation will be described taking a copying machine using the module as an example. FIG. 1 is a block diagram illustrating a copier divided into a plurality of modules according to the first embodiment.

  Reference numeral 11 denotes a printer block (hereinafter referred to as a printer). The printer 11 includes modules of an upper manager 1, a paper feed module 2, an image forming module 3, a transport module 4, a fixing module 5, and a paper discharge duplex copy switching module (hereinafter referred to as a paper discharge module) 10. In each module, electrical hardware and software for operating the module are integrated, and connected to the upper manager 1 via a communication line 6, for example, a general-purpose communication line such as CAN.

  The printer 11, the image control module 12, the reader module 14, and the key control module 13 constitute the entire copying machine system. The upper manager 1 and the image control module 12 are connected by an independent signal line 17 for transferring control parameters. The reader module 14 and the image control module 12 are connected by a signal line 15, and the image control module 12 and the key control module 13 are connected by a signal line 18. It is also possible to connect the signal line 17 to the communication line 6 and handle it as a CAN bus.

  Further, the image forming module 3 and the image control module 12 have a structure capable of exchanging image data through a signal line 19. A timing signal transmission line 16 is connected from the image control module 12 to the paper feed module 2.

  Further, a timing signal transmission line 7 is connected between the image forming module 3 and the paper feed module 2, and a timing signal transmission line 20 is connected between the image forming module 3 and the transport module 4.

  A timing signal transmission line 9 is connected between the transport module 4 and the fixing module 5, and a timing signal transmission line 21 is connected between the fixing module 5 and the paper discharge module 10. A timing signal transmission line 8 is connected between the paper feed module 2 and the transport module 4.

  Next, the operation will be described. When the power is turned on, the modules from the upper manager 1 to the fixing module 5 and the modules of the paper discharge module 10, the key control module 13, and the reader module 14 first perform a power-on reset. Thereafter, internal initialization is performed for each module (specifically, whether there is an IO short-circuit or the like), and operation is started for each module.

  As in the case of the fixing module 5, the specifications of each module are transmitted to the upper manager 1 in the order in which they are ready, and to the effect that they are in an operable state.

  For this protocol, the CAN protocol used for automobiles and the like is used. By providing a flag that can be received only by the upper manager 1 in the communication data, the upper manager 1 can easily receive the status information from each module. Upon receiving this, the upper manager 1 requests each module to transmit operating condition information.

  As a result, each module transmits information to the upper manager 1. For example, the paper feed module 2 uses an internal sensor to determine information such as the number of paper feed stages, the amount of paper that can be fed, the number of paper remaining, the speed of paper feed, the paper feed size, and the paper feed direction. Then, it transmits to the upper manager 1.

  Similarly, the image forming module 3 transmits information such as color / monochrome, 4 drums / 1 drum (hereinafter referred to as 4d / 1d), transfer development process speed, used toner type, and the like to the upper manager 1. Similarly, the transport module 4 sends information such as transport speed, transportable material, color / monochrome, double-sided copy transport with / without transport, transport distance, 4d / 1d, and transport control method to the upper manager 1. Similarly, the fixing module 5 transmits the fixing device type, temperature control temperature range, fixable paper type information, and fixing speed information to the upper module 1 as described above.

  Similarly, the paper discharge module 10 transmits the number of paper discharge trays, sorter option interface information, paper discharge speed information, and usable material information to the upper manager 1.

  The upper manager 1 determines the optimum specification of each module so as to fall within the specification based on the operating condition information of the module obtained from each module. At this time, the optimum operating condition information of the image forming apparatus and the target specifications of the copying machine registered in advance in the upper manager 1 are used as a reference. Then, the result is set from the upper manager 1 to each of the paper feed module 2, the image forming module 3, the transport module 4, the fixing module 5, and the paper discharge module 10 through the communication line 6.

  Specifically, the parameter that must be determined through all modules is the paper conveyance speed, and determining the timing of paper handling is a very important issue in the control of the copying machine. Each module calculates and sets other parameters that must be adjusted in accordance with the transport speed in each module. For example, in the fixing module 5, it is necessary to calculate and set the fixing temperature according to the conveyance speed and the paper type. Further, in the image forming module 3, it is necessary to change an algorithm, reset a process parameter such as a set voltage (tuning), and change a control timing sequence according to the conveyance speed.

  A part of the module operation condition information extracted by the upper manager 1 is transferred to the image control module 12 through the signal line 17 and set. Specifically, color / monochrome, 4d / 1d information, paper type, paper feed cassette type, number, type and number of paper discharge modules, and the like.

  Thereafter, when each module enters an operable state under the set transport speed condition, it transmits the status information to the upper manager 1 and enters a waiting state.

  Next, the actual operation will be described. The image control module 12 decodes and determines the command input to the key control module 13. For example, if the instruction is “read information on the reader and copy it on one side”, the image control module 12 instructs the reader module 14 to read the image information.

  Then, processing for fetching the read result into its own frame memory is executed, and information is transferred to the upper manager 1 of the printer 11 before issuing a print start command. Here, the information includes the type of job (copying), the number of sheets, the size of the medium (A3, A4), the type (plain paper, cardboard, OHP), single-sided printing, and the like.

  Next, the upper manager 1 sets the information in each module from the paper feed module 2 to the fixing module 5 and the paper discharge module 10, and sets the individual modules in an operable state under the conditions. When the setting is completed, each module transmits a setting end flag to the upper manager 1 and enters a waiting state. The upper manager 1 confirms that the modules from the paper feed module 2 to the fixing module 5 and the paper discharge module 10 are in a waiting state. Then, the upper manager 1 transmits information that can start the printing operation to the image control module 12 through the signal line 17.

  The image control module 12 is in a print start ready state for the first time in this state. Then, an image necessary for starting printing is read by the reader module 14 and stored in the frame memory. At this time, the image control module 12 transmits a print start signal to the paper feed module 2 and the image forming module 3 through the timing signal transmission line 16 and the signal line 19.

  Here, it is assumed that the currently set information is “monochrome, A4, one sheet, single side”, and the image forming module 3 is a 1d monochrome image forming module. In this case, since the printer 11 is a monochrome printer (hereinafter referred to as a monochrome printer), the image forming module 3 is mounted for monochrome. The monochrome printer needs to be able to transmit a timing signal to another module using the paper feed module 2 as a base point, which is called a normal paper standard. Therefore, the upper manager 1 sets an operation base point and a signal transmission direction for the paper feed module 2 and the image forming module 3.

  When a start timing signal is input from the image control module 12 to the paper feed module 2 through the timing signal transmission line 16, the paper feed module 2 starts paper feeding according to preset information. When the sensor in the paper feed input unit detects that the paper has started to be fed, the paper feed module 2 propagates the signal to the image forming module 3 via the timing signal transmission line 7.

  In response to the signal, the image forming module 3 starts operation preparation, and starts rotation of a motor such as a developing roller and a transfer roller. The development, transfer roller, and polygon motor of the image forming module 3 control the motor so that the rotation is stabilized so as to match the paper conveyance speed. When the leading edge of the paper is detected by the registration detection sensor unit of the output unit of the paper feed module 2, an image formation timing signal is transmitted from the paper feed module 2 to the image forming module 3. An image enable signal based on a BD (Beam Detect) signal synchronized with the rotational position of the polygon motor is generated by the image forming module 3 and transferred to the image control module 12 via the signal line 19. Then, the image signal synchronized therewith is read from the frame memory of the image control module 12 and transferred to the image forming module 3 as an image signal, and exposure of the photosensitive member by the exposure device 708 is started.

  At the same time, the controller of the image forming module 3 starts control of the image forming module 3 so that a high voltage is applied to the developing and transfer rollers and the image forming process of the image forming module 3 starts. The paper transferred and developed by the image forming module 3 is sent from the output end of the image forming module 3 to the transport system. In the transport module 4, the operation is started based on the information of the registration detection sensor, and a motor or the like is rotated in advance so that the paper is transported at a necessary transport speed. The transport module 4 transports the paper to the fixing module 5. In this case, a medium detection sensor is attached to the input unit of the conveyance module 4, and when the paper passes through the medium detection sensor, an operation start signal is transmitted to the fixing module 5 through the timing signal transmission line 9. The fixing module 5 is controlled so that the rotation speed of the fixing motor is adjusted to the paper conveyance speed, the heater temperature of the fixing device is raised to a necessary fixing temperature, and the paper is conveyed.

  There is a sensor at the entrance of the fixing module 5, and this sensor can detect that paper has been conveyed to the fixing module 5. When the sensor detects that the paper has been conveyed, the controller of the fixing module 5 sends a signal to the paper discharge module 10 through the timing signal transmission line 21 so that the paper discharge motor is set up in accordance with the fixing speed. Send.

  The paper discharge module 10 also has a sensor at its output end. When the paper discharge is completed, the controller of the paper discharge module 10 detects a completion signal output from the sensor, and when it matches the number of sheets to be printed, it is normally terminated to the upper manager 1 through the communication line 6. Send information. On the other hand, if it does not match the number of prints, the reader module 14 also enters a waiting state in preparation for the next paper feed.

  Next, the case where the printer 11 is a color printer will be described. A 4d printer using an intermediate transfer member is different from the first embodiment in which a latent image is created on a drum based on the leading edge of the paper conveyed from the paper supply module 2. That is, the exchange of signals between modules is different from that of the first embodiment, and will be described next.

  When the image forming module 3 uses an intermediate transfer member (hereinafter referred to as an intermediate transfer belt), the signal transmission direction changes, and will be described next. In this embodiment, the details of the operation timing of the printer unit of the color copying machine are omitted, but the outline will be described. FIG. 2 shows an actual color printer configuration corresponding to the module separation. The modules 12, 13, and 14 in FIG. 1 are not shown.

  In this case, when receiving a start signal from the image control module 12 (not shown), the image forming module 3 first performs a pre-rotation until the intermediate transfer belt 702 rotates at a predetermined stable speed. Then, the following operation is performed at the stage when the intermediate transfer belt 702 is rotated at a steady state. In other words, the reflection type sensor 736 that detects the reference position of the image formation timing between the backup roller 719 and the tension roller 720 reads the reference position mark of the image formation timing provided on the intermediate transfer belt 702. The signal is used as the exposure timing of the exposure device 708 to start image formation, and a full-color toner image is formed on the intermediate transfer belt 702. Thereafter, a start signal is transmitted to the paper feed module 2 through the timing signal transmission line 7.

  Thereafter, when a start signal is transmitted from the output end of the image forming module 3 to the transport system, an operation start signal is transmitted to the transport module 4 through the timing signal transmission line 20 based on the information of the reflective sensor 736. . Then, the paper is transported by the transport module 4 whose motor or the like has been rotated so that the paper is transported at a necessary transport speed in advance, and is transported to the fixing module 5. In that case, a medium detection sensor (not shown) is attached to the input section of the transport module 4, and when the paper passes through it, an operation start signal is transmitted to the fixing module 5 through the timing signal transmission line 9. The fixing module 5 is controlled so that the rotation speed of the fixing motor is adjusted to the paper conveyance speed, the heater temperature of the fixing device is raised to a necessary fixing temperature, and the paper is conveyed.

  A sensor (not shown) is provided at the entrance of the fixing module 5 and can detect that paper has entered the fixing module 5. When the sensor detects that paper has entered, the controller of the fixing module 5 transmits a signal to the paper discharge module 10 through the timing signal transmission line 21 so as to start up the paper discharge motor in accordance with the fixing speed. To do.

  Here, what is important is that if the upper manager 1 knows in advance a module that generates a reference signal for image formation and the module is changed, it is necessary to change the setting.

  That is, in the first embodiment, since the signal is generated based on the paper, the module that generates the image formation reference signal is the paper feed module 2. On the other hand, in the case of the color printer of this embodiment, the image forming module 3 is a module that generates a signal based on the latent image on the intermediate transfer belt 702 and performs a copying operation based on the reference. This case is referred to as an image-based operation. For this reason, the upper module 1 needs to set the information in the paper feed module 2 and the image forming module 3 in advance.

  Then, even if the start signal from the controller of the image control module 12 is simultaneously applied to the paper feed module 2 and the image forming module 3 through the timing signal transmission line 16 and the signal line 19, the following operation is performed. That is, in the case of paper-based control, in accordance with the information, after completion of the necessary preliminary operation, the signal is transmitted in such a procedure that the control signal is transmitted from the paper supply module 2 to the image forming module 3. The interface is adjusted. On the other hand, in the case of image-based control, in accordance with the above information, after completion of the necessary preliminary operation, the signal is transmitted in such a procedure that the control signal is transmitted from the image forming module 3 to the paper feed module 2. The interface is adjusted.

  Further, if necessary, it is possible to transmit the paper transport speed of the paper feed module 2 to the transport module 4 through the timing signal transmission line 8 so that the motor speed of the transport module 4 is matched.

  In FIG. 2, the paper feed module 2 includes a paper feed cassette 723, a pickup roller 724, and a roller pair 726. The image forming module 3 includes a photosensitive drum 701, a potential sensor 703, a primary charger 707, a cleaning device 712, and a developing unit 713. The image forming apparatus includes an intermediate transfer belt 702, a transfer charger 710, a driving roller 717, a roller 718, a backup roller 719, a tension roller 720, a cleaning device 722, a reflective sensor 736, and an exposure device 708. Here, the developing unit 713 includes developing units of black 613K, yellow 713Y, magenta 713M, and cyan 713C. The transport module 4 includes a registration roller pair 725 and a secondary transfer roller 721. The fixing module 5 includes a fixing device 705. The paper discharge module 10 includes a paper discharge roller (not shown) and a paper discharge tray (not shown).

  Next, FIG. 3 shows an internal configuration of a basic module (hereinafter referred to as a basic module). 3-1 is an example of the internal configuration of a basic module constituting the present invention. Reference numeral 3-2 denotes a CPU, which can communicate with upper modules through a communication control interface 3-12 through a bidirectional communication line 3-19.

  As a communication line suitable for this communication, a CAN bus that is inexpensive in a copying machine and standardized in an automobile can be used. This will be described in the fourth embodiment. Reference numeral 3-3 denotes a control circuit, which is a motor control circuit that requires precise control and a circuit that is configured by an ASIC for control such as a clutch, and is considered to be usable in all modules. Specifically, this is a device control circuit that controls the motors and motor drivers 3-5 and 3-6, and controls the device dedicated to the module, and is configured so that other devices of the control module 3-4 can be controlled. Has been.

  Reference numeral 3-7 denotes a power supply, which is not shown in the circuit, but supplies power to all internal structural blocks. Reference numeral 3-8 denotes an oscillation circuit which oscillates a reference frequency used for operation by a crystal resonator, and uses all of the high-precision modules that fall within ± 1%. In the upper module, a measurement circuit is configured in the control circuit 3-3 so that the oscillation frequency of the oscillation circuit 3-8 can be checked via the bidirectional communication line 3-19.

  Reference numeral 3-9 denotes an EEPROM which stores a control program for the CPU 3-2 for controlling the module. 3-9 is more preferably a non-volatile RAM (such as FeRAM).

  Reference numerals 3-10 and 3-11 denote sensor modules which are used for detecting paper in the module. A DA converter 3-13 is connected to one input terminal of the analog switch switching circuit 3-15, and the other end is connected to the analog IO terminal 3-17.

  The other input terminal of the analog switch switching circuit 3-15 is connected to the analog data input terminal 3-23 of the AD converter 3-14. The control terminal of the analog switch switching circuit 3-15 is connected to the output port 3-24 of the CPU 3-2. When the output of the output port 3-24 is H, the analog output signal of the DA converter 3-13 is output to the analog IO terminal 3-17, and when it is L, the analog signal of the analog IO terminal 3-17 is output. The signal is input to the analog input terminal 3-23 of the CPU 3-2.

  Reference numeral 3-16 denotes a bidirectional buffer whose control terminal is connected to the control output port 3-20 of the CPU 3-2. The output terminal of the bidirectional buffer 3-16 is connected to the port 3-18, and the input terminal of the bidirectional buffer 3-16 for outputting a signal to the port 3-18 is connected to the output port 3-21 of the CPU 3-2. Connected. Then, the output terminal of the bidirectional buffer 3-16 whose input terminal is connected to the port 3-18 in order to capture the signal of the port 3-18 into the CPU 3-2 is connected to the input port 3-22 of the CPU 3-2. Has been. The clock output terminal of the oscillation circuit 3-8 is connected to the clock input terminals of the other control module 3-4, the control circuit 3-3, the motor and motor drivers 3-5 and 3-6, and the CPU 3-2 at 3-50. It is connected.

  Next, the operation will be described. A switch (hereinafter referred to as SW) 3-30 is a SW for testing the single module single unit operation and a SW that can be turned on by a remote signal from the outside. When the SW 3-30 is turned on, the + (minus is a common potential at GND) terminal 3-29 of the power source 3-7 is connected to the power input terminal of the power-on reset circuit 3-25, and the power source is powered on. Input to the reset circuit 3-25. As a result, this power is supplied to the 3-27 terminal and a + power supply terminal necessary for the basic module 3-1, although not explicitly shown. Also, an external AC power source is connected to 3-7 via 3-28, and a necessary DC voltage, for example, a voltage of 3.3V, is supplied to the DC output terminal 3-29.

  As a result, when the power-on reset circuit 3-25 detects that the 3-27 terminal has risen to a voltage at which the CPU 3-2 and the control circuit 3-3 can operate normally, the values of the reset terminals 3-26 and 3-31 Goes from L to H. Then, the reset state of the CPU 3-2 and the control circuit 3-3 is canceled (during the entire operation, the direct current voltage generated by the entire drive power source from the 3-27 terminal is directly 3 with the 3-30 being off. It is also possible to add to -25).

  At the same time as the power is turned on, the oscillation circuit 3-8 starts operating, and supplies a clock to the CPU 3-2, the control circuit 3-3, the other control module 3-4, the motor and the motor drivers 3-5 and 3-6. After the initialization of the CPU 3-2, the CPU 3-2 starts operation based on the program stored in the EEPROM 3-9. When this is the fixing module 5, for example, the other control module 3-4 can be a fixing heater, and the sensor module 3-10 can be configured to control its temperature control with a thermistor.

  Further, the control circuit 3-3 is a control circuit including a motor control circuit, and controls the motor and motor driver modules 3-5 and 3-6. The CPU 3-2 controls the motor and motor driver 3-5, 3-6 motor can be controlled. After performing initial control of these modules, the CPU 3-2 communicates the specifications and states of the modules to the upper module through the bidirectional communication line 3-19.

  Next, the upper module communicates the control condition of the module to the communication control interface 3-12 through the bidirectional communication line 3-19. The communication control interface 3-12 stores this information in a built-in memory, and sets control parameters based on the information. Specifically, the upper manager 1 sets the direction control of the analog switch switching circuit 3-15 and the bidirectional buffer 3-16 via the bidirectional communication line 3-19 and the CPU 3-2. The bidirectional buffer 3-16, the port 3-18, and the direction control circuit can have a bus structure, and the CPU 3-2 can control each bit.

  Next, consider the case where the basic module 3-1 is the paper feed module 2. In the case of a 1d monochrome printer, the timing signal transmission line 16 of FIG. 1 is set to 1 bit of the LSB of the port 3-18, and the CPU 3-2 controls 3-20 by a parameter setting register (not shown). The LSB of this bus is set as the input port. Further, the timing signal transmission line 7 is set to 1 bit of the MSB of the port 3-18, and 3-20 is controlled by a register (not shown) to set the MSB of the bus of the port 3-18 as an output port.

  Further, the CPU 3-2 uses the analog IO terminal 3-17 to detect the motor speed of the motor of the paper feed module 2 and the motor drivers 3-5 and 3-6 by the sensor module 3-10 or 3-11. To do. Then, the speed information can be analog-converted by the DA converter 3-13 and transmitted to the transport module 4 via the timing signal transmission line 8.

  On the other hand, in the case of a 4d color printer, the upper manager 1 sets the sheet feeding module 2 through the communication line 6 so that the transmission direction of the timing signal transmission line 7 is reversed. The CPU 3-2 recognizes the information, and controls the timing signal transmission line 7, that is, the 1 bit of the MSB of the port 3-18 by using a register (not shown) to make the input port 3-20.

  As described above, the other modules also use the analog IO terminals 3-17 and the ports 3-18 to set the direction control in advance so as to match the control. In this way, the CPU 3-2 controls the information set through the bidirectional communication line 3-19 and the timing signal exchanged via the analog IO terminal 3-17 and the port 3-18. Can start.

  At that time, what is important is that the upper manager 1 can check whether there is no problem in the connection between the modules. A description will be given of module connection between the paper feed module 2 and the image forming module 3 in which the connection direction is easily switched.

  Here, in the module 3-1 constituting the image forming module 3, the timing signal transmission line 7 is connected to a terminal corresponding to the MSB of the port 3-18, and the timing signal transmission line 20 is connected to the port 3-18. It is assumed that it is connected to a terminal corresponding to the LSB.

  In the case of a 1d monochrome printer, the upper manager 1 sets the MSB bit of the port 3-18 of the paper feed module 2 to the output mode, and sets the MSB bit of the port 3-18 of the image forming module 3 to the input mode. Set to.

  Then, the data of the port 3-18 of the paper feed module 2 is switched to 0 and 1, and the CPU 3-2 of the image forming module 3 reads the data of the port 3-18 by the image forming module 3 each time. Then, the CPU 3-2 sends information indicating that there is no problem in the setting to the upper manager 1 through the communication line 6 each time. The upper manager 1 can determine whether the displacement is correctly transmitted, and the upper manager 1 can check the connection between the modules.

  The same is possible with the analog IO terminal 3-17.

  In this case, the port receiving this signal is a direct input terminal to the AD converter 3-14 and an analog input terminal 3-51. In the case of an analog signal, the upper manager 1 sets digital data in the DA converter 3-13 on the sending side through the CPU 3-2 in advance, and the AD converter of the module on the receiving side receives the analog data converted by the DA converter 3-13. Read in 3-14. The CPU 3-2 receives the result and returns it to the upper manager 1 through the bidirectional communication line 3-19 to correlate the setting data with the received data. If necessary, the upper manager 1 can instruct the module to correct the received data with the correlation coefficient.

  In addition, the sensor modules 3-10 and 3-11 can be used as sensors for detecting whether or not there is a medium such as paper in the module. When the sensor may be binary, the sensor module 3-11 is used, and the CPU 3-2 can detect by reading on / off at the digital port.

  If the sensor is analog, the sensor module 3-10 is used and read by the AD converter 3-14 of the CPU 3-2 to determine whether a medium such as paper is in the module, whether it has entered, or has gone out. It is arranged and controlled in the module so that it can be detected.

  Next, a communication method in actual operation will be described. The upper manager 1 sets a start module for the timing signal. Then, the module that receives the signal finishes all the processing in advance, and the CPU 3-2 always reads the port 3-18, thereby speeding up the start timing of the module. is there.

  Here, consider a case where the clock of the CPU 3-2 is 20 MHz and a three-state operation is performed. In this case, the start signal is received at a maximum of 20/3 = 6 MHz or more, that is, every 200 nsec, and the operation of the module can be started.

  Normally, each module operates asynchronously, so that it is possible to receive a reliable start signal every two times, ie, every 400 nsec. On the other hand, general CAN communication is communication with a communication rate of 1 Mbps or less, and is multi-bit communication data including redundant bits such as error correction. For this reason, the time during which data can be set by a command including correction is 1 msec or less, and there is a difference of 3 orders if start information is sent by each communication method.

  Actually, in the image forming apparatus, if an error of 1 msec occurs as described above, the image is affected, so that it is difficult to use it as a timing signal.

  Next, the case of black and white double-sided copying will be described with reference to the block diagram of FIG. In the case of duplex copying, single-sided copying has no problem with the same processing as in the first embodiment. After copying on one side, the paper is once transported to the paper discharge module 10, and when the paper trailing edge detection sensor in the input section detects the paper trailing edge, the paper discharge motor of the paper discharge module 10 starts to reversely rotate. . At the same time, the paper discharge module 10 sends a command to the upper manager 1 to switch the direction of the timing signal transfer path between the fixing module 5 and the paper discharge module 10, specifically, in the bidirectional buffer 3-16 of the basic module 3-1. , Switch the direction of tri-state IO. Then, the bidirectional buffer 3-16 of the paper discharge module 10 is used as an output terminal, and the port 3-18 connected to the bidirectional buffer 3-16 of the fixing module 5 is switched to an input terminal. Then, the paper discharge module 10 sends a start signal for the fixing module 5 through the IO.

  As a result, the motor of the fixing module 5 is rotated in the reverse direction, and the paper is fed back into the fixing module 5. When the trailing edge of the paper is detected by the sensor at the output portion of the fixing device 705, the fixing module 5 switches the branching unit provided upstream of the fixing device 705 and switches back the sheet on which the image is formed on one side. Introduce into the circulation path. When copying both sides of the sheet, as described above, it is necessary to switch the transmission direction of the timing signals of the fixing module 5 and the paper discharge module 10 in real time. Even in such a case, the upper manager 1 controls it. Is possible.

  When the timing is not in time, it is possible to add one signal line so that both can transmit and receive at the same time.

  Next, FIG. 4 shows a CAN bus and units connected to the CAN bus. The CAN is basically an asynchronous communication system, and as shown in FIG. 4, transmission is possible only with two twisted pairs. Each module is connected by CAN, and is identified by a number such as unit 1 to unit 4, for example.

  Both ends are connected by a terminating resistor, and basically, real-time asynchronous transmission in units of 10 msec is possible.

  The CAN data frame is composed of the following information. That is, SOF (Start Of Frame) indicating the head of the frame, identifier ID, control code, data, CRC (Cyclic Redundant Check), ACK (ACKnowledge), and EOF (End Of Frame). Asynchronous transmission is possible from any module. The information transmitted by the upper manager 1 is received by all modules, and if it is intended for a specific module, it is possible to provide the communication partner unit number in the 8-bit data.

1 is a block diagram showing a copying machine divided into a plurality of modules according to an embodiment of the present invention. 1 is a schematic cross-sectional view showing correspondence between components and components of a copying machine according to an embodiment of the present invention. The block diagram which shows the internal structure of the basic module which concerns on one Example of this invention. The figure which shows the unit connected to the CAN bus and CAN bus which concerns on one Example of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper manager 2 Paper feed module 3 Image formation module 4 Conveyance module 5 Fixing module 6 Communication line 7, 8, 9, 16, 20, 21 Timing signal transmission line 10 Paper discharge module 11 Printer block 12 Image control module 13 Key control module 14 Reader module 15, 18, 19 Signal line 17 Signal line

Claims (12)

The module is divided into a plurality of modules, and the module has at least an electric circuit for controlling the module and a control circuit for controlling the electric circuit that can be controlled by a program. An image forming apparatus capable of executing the operation of the module in the image forming apparatus in a single unit,
At least one of the plurality of modules is an upper manager;
Communication between the upper manager passing the control parameters and other modules excluding the upper manager is performed by an operation mode signal,
An image forming apparatus, wherein communication between the other modules is performed by a timing signal.   The image forming apparatus according to claim 1, wherein the timing signal communication line is provided exclusively between the other modules.   The image forming apparatus according to claim 1, wherein the upper manager controls a transmission direction of the timing signal.   The image forming apparatus according to claim 1, wherein a communication speed between the other modules is equal to or faster than a communication speed between the upper manager and the other modules.   Between the other modules is between two adjacent modules that are driven in accordance with the transport order in which the print medium is transported, and includes a paper feed module, an image forming module, a transport module, a fixing module, and a paper discharge. 2. The image forming apparatus according to claim 1, wherein the combination is at least one of combinations of at least two modules of the duplex copy switching module.   The image forming apparatus according to claim 1, wherein the module performs communication based on the timing signal only between adjacent modules.   The operation mode signal includes a signal for verifying that communication satisfying a regulation by the timing signal is performed between the other modules, and a signal of the verification result. The image forming apparatus according to claim 1, wherein communication is verified by the timing signal in response to a manager command, and the verification result is returned to the upper manager by the operation mode signal.   The image forming apparatus according to claim 1, wherein communication between the other modules is performed using two or less signal lines.   The image forming apparatus according to claim 1, wherein communication between the other modules is performed at an analog voltage level.   The image forming apparatus according to claim 1, wherein the operation start signal of the other module is detected directly by the module without passing through the upper manager, and is propagated and operated between the other modules.   The image forming apparatus according to claim 1, wherein the timing signal includes at least a start signal and an operation start signal of the other module.   The module has at least one sensor for detecting a print medium, and transmits a start signal or an operation start signal to an adjacent module to which the print medium is transported based on a timing at which the sensor detects the print medium. The image forming apparatus according to claim 1.

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