JPS61114358A - Controller - Google Patents

Abstract

PURPOSE:To attain the control of plural subjects in a sure way with a simple procedure by providing plural control parts to give the independent control to each of plural control subjects. CONSTITUTION:Controllers 221-223 control the operations of each constitution of a copying machine under the control of a main control part 200. A monitor CPU201 of the part 200 performs the control of the entire part of a control system CPU300 as well as the schedule control for processing execution. The CPU300 carries out each task processing under the control of the CPU201. The periods of time for occupation of a system bus 204 are set successively and in time division for each CPU so that no conflict is produced when both CPU300 and 201 give accesses to a RAM202 and an input/output part 203. Thus the cyclic and clockwise operations are carried out in time division between a CPUa310 and a CPUh380.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a control device suitable for controlling a plurality of control objects.

[Prior art] Recent advances in semiconductor integrated circuit technology and the synergistic effect of computer technology have led to remarkable improvements in the functions of OA equipment.
As the functions of Type A equipment improve, the contents of the machines that need to be controlled have become more complex and sophisticated, the amount of control has become enormous, the overhead for inputting and outputting to each load has increased, and the CPU that performs control has become more efficient. There was no choice but to make it more advanced and with a larger bit capacity. Along with this, it was inevitable that the hardware configuration would become more complex and larger, and the software configuration would become more complex and sophisticated, resulting in an increase in product prices.

Furthermore, as the hardware configuration becomes more complex and larger, the number of signal lines within the device increases, and the wiring of the signal lines becomes complex and diverse.As the amount of control increases, the number of wiring increases.

If the number of such wire bundles (harnesses) is large and large, it will be more susceptible to the effects of induced noise from other signal lines, and this will lead to larger equipment.This is due to customer demand for smaller and lighter equipment. This is contradictory.

FIG. 1 shows an example of the configuration of a conventional copying machine, which is a medium-sized OA type device.

Here, we use inexpensive ROM and R for controlling each part of the copying machine.
AM, I10 control section, analog to digital two-
A total of 6 single-chip CPUs are used, including an integrated CPU. This one-chip CPU is manufactured by NEC.
I am using COM87AD.

The controlled objects of the copying machine are distributed and controlled by four one-chip CPUs, and the master CPU 110 controls operations, displays, and sequence control 111 using the slave CPUs.
Reference numeral 112 mainly controls the stepper motor and developer control @113.

In addition, the slave CPUB114 mainly controls the DC servo motor 115 using PLL control.
Reference numeral 14 mainly controls the potential control of the photoreceptor, erasing, and stabilization control 117 of the light amount of the exposure halogen lamp.

On the other hand, slave CPUD as a control for peripheral devices of the machine
120 controls an auto document feeder (automatic document feeder) 121, and a slave CPU 130 controls a sorter 131. Conventionally, a bus consisting of a large number of signal lines was used for control between these one-chip CPUs. are connected to each other by And ADF (auto document feeder) 121 as a peripheral device of the machine,
Just by adding the sorter 131, a total of six one-chip CPUs are used, including those to be controlled by the main body of the copying machine.

On the other hand, if the sorter 131 is connected in parallel (multiple sorters are connected in series) or if a paper deck (large urn copy cassette), charge counter, OMR, OCR, etc. are connected as accessories, As a result, the number of single-chip CPUs used increases. With this system configuration, communication between CPUs becomes complicated, and it is essential that signal connections between them become complicated. This tendency will increase as the number of external devices to be connected increases and the number of CPUs for control increases accordingly.

For this reason, when a certain protocol is determined for communication between CPUs and some information is to be sent from the master CPUll0 to a specified slave CPU, address information and data information are sent via the bus in a time-sharing manner, but depending on the program control. The overhead becomes very large. or,
Even when receiving data, program processing must be performed to decode the received data, which also takes a considerable amount of time. Since the overhead caused by transmission and reception increases in this way, it becomes impossible to respond to responses that require high speed.

Conventionally, the serial communication function built into a microcontroller generates an internal interrupt when transmitting or receiving, and each time this interrupt occurs, the CPU
interrupts the currently executing task and enters the interrupt handling routine. Therefore, if an external interrupt or multiple communication interrupts are input at the same time, the task currently being executed must be interrupted for a long time, and the impact of this cannot be ignored, so it is important to consider this when creating a program. Programming must take into account various situations, and great care must be taken when creating a program. In addition, such multiple interrupts often cause problems in processing, which may adversely affect the control performance.

In addition, the longer interconnection signal lines (connection cables) between CPUs and the resulting delay in signal transmission timing, as well as the effects of induced noise from other signal lines and the external environment, can cause malfunctions of the entire device, reducing device reliability. This resulted in a decrease in

[Objective] The present invention aims to eliminate the drawbacks of the above-mentioned prior art, and aims to provide a control device that reliably controls a plurality of control objects using a simple control procedure.

[Example] Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a schematic cross-sectional view of the mechanism of a vehicle-mounted automatic double-sided copying machine according to an embodiment of the present invention.

The functions of this embodiment can be roughly divided into four blocks: a paper feeding system, an exposure system, an image forming system, and a control system. The operation of this embodiment will be explained below based on FIG.

First, a user who wants to make a copy opens the document table cover 1 and sets an original (original). When reducing or enlarging the original, the scaling factor is set as necessary using the scaling key on the operation unit (not shown). Further, the number of copies, automatic or manual selection of density, and selection of single-sided or double-sided copy mode are performed using the respective keys on the operation unit.

To perform double-sided copying, select the copy mode to double-sided, and press the copy start key on the operation unit.

As a result, the halogen lamp 3 is turned on, and then the photoreceptor drum 20 starts rotating, the charging corona 13 is energized, and the photoreceptor drum 20 is charged. The halogen lamp (exposure lamp) 3 and the first mirror 4 have the same structure, and the zero image that scans the document surface in synchronization with the rotation of the photosensitive drum 20 is produced by the first mirror 4 and the second mirror. 51. Third
An optical axis is formed by the fourth mirror 7, the fifth mirror 8, and the sixth mirror 9 through the mirror 6 and the zoom lens 11, and an image is formed on the surface of the photosensitive drum 20, forming a latent image on the surface of the photosensitive drum 20. Form. Subsequently, the surface potential of the portion of the surface of the photosensitive drum 20 where no latent image is formed is removed by the erase lamp 15 in accordance with paper nizing, and then the surface of the photosensitive drum 20 reaches the developing section 17, and the surface potential of the surface of the photosensitive drum 20 is removed. Toner adheres depending on the surface potential, and the latent image is visualized.

On the other hand, the paper feed roller 2 of the selected cassette 22 or 24
The transfer paper fed by 1 and 23 is transferred to the registration roller 30.
I'm waiting. Then, the registration roller 30 rotates at a predetermined timing synchronized with the rotation of the photosensitive drum 20, aligning the image on the surface of the photosensitive drum 20, and then applying the force of the transfer corona 14 on the image on the surface of the photosensitive drum 20. The image is transferred to a transfer paper. The transfer paper is separated from the photosensitive drum 20 by a zero-order separation roller 31 and is transported to a fixing section 33 by a paper transport belt 32. The transfer paper is heated and pressurized by the fixing section 33, and the toner on the transfer paper is fused.

Here, since the copy mode is double-sided mode, the paper guide plate 34 guides the transfer paper to the paper discharge roller 37, and the paper guide plate 34 guides the transfer paper to the paper discharge roller 37.
It will be carried once at 8. The paper conveyed here is slid downward by gravity, is added to roller 39, and is stocked in intermediate cassette z6. Note that the transfer paper is not stocked on the double-sided paper discharge table 38, but slides down one by one.

In this way, the preset number of sheets whose front surfaces have been copied are sequentially stored in the intermediate cassette 26, while the image on the surface of the photosensitive drum 20 that has been transferred is transferred to the cleaning section 26.
9 and cleaning on the drum surface is performed. At this point, the remaining toner adhering to the surface of the photosensitive drum 20 is removed. Further, the surface of the photosensitive drum 20 is irradiated with a static elimination lamp 18, and the residual potential on the drum surface 20 is removed.The surface of the photosensitive drum 20 is newly charged by the zero-order charging corona 13, and a predetermined surface potential is applied to the drum. This enables new image formation.

Next, when the specified number of copies of one side (front side) are completed, the operator changes the original on side 2 of the document and performs the next copy operation (back side copy).

When the original is set and a new copy start key is input on the operation unit (not shown), the copying operation for the back side starts. The intermediate paper feed roller 25 rotates at a predetermined timing synchronized with the rotation of the photosensitive drum 20, and the transfer paper is fed by the intermediate cassette 26. The paper is half-turned by the guide plate 29 and inserted into the registration rollers 30. Here, it waits until a start signal is received at a predetermined timing to align the leading edge with the image formed on the surface of the photosensitive drum 20.

The registration rollers 30 rotate at a predetermined timing to align the leading edges of the images, and the image formed on the photosensitive drum 20 is transferred. At this time, the transfer corona 14 is energized at a predetermined timing and the image is transferred to the back surface. Then, it is separated from the photosensitive drum 20 by a separation roller 31 and conveyed to a fixing section 33 by a conveyor belt 32. Here, the toner on the transfer paper is fused. The transfer paper is then added to the roller 40. Since the back side copying has now been completed, the guide plate 34 is guided to the paper discharge tray 30, and the transfer paper is stocked on the paper discharge tray 36 after copying on both sides. In this way, the double-sided copying process is completed.

During normal one-sided copying, the paper fed from the cassette 22 or 24 is transferred to the intermediate cassette 26 in a blank state with only the paper transport system energized. At this time, the image forming system does not operate at all, and only the system that feeds paper from the paper feed cassette 22 or 24 and conveys the paper to the intermediate cassette 26 operates.

On the other hand, this embodiment is provided with an automatic exposure function in order to improve the quality of copies. This is to control the surface potential on the photosensitive surface to a constant value so that a good density can always be obtained regardless of the original density.

Before starting copying, the surface potential is first monitored. This involves irradiating the photosensitive drum 20 with the voltage reflected by the standard reflector 10, monitoring it with the surface potential sensor 16, and first controlling the corona voltage of the band/sparkling corona 13 so that it becomes an appropriate value. During copying/editing, when the user sets the copy density to auto mode and places the plate, the optical system performs prestoyaning to monitor the original, monitors the density of the original, and sets the bias voltage and bias value. If the prescan operation is troublesome because it is monitored every time a copy is made, the value of the developing bias is controlled so that the appropriate density is achieved while sequentially monitoring the document density in real time.

In the case of continuous copying (when making multiple copies from the same original), the appropriate density can be achieved by controlling the corona voltage and lamp light intensity from the second copy.

Further, in this embodiment, an automatic document feeder (hereinafter referred to as ADF), a printer or collator, a vapor deck, a charge counter, etc. can be connected to the main body of the copying machine shown in FIG.

Next, FIG. 3 shows a control function block diagram of this embodiment.

In FIG. 3, 200 is a main control unit of the copying machine, and 221 to 223 are controllers n1 to n3 that control the operation of each component of the copying machine under the control of the main control unit 200. Three examples are shown here as an example. is shown, LA in the main control unit 200
An arbitrary number of devices can be added to the LAN bus 260 from the N interface section 210. In addition, 240 is the main control unit 20
250 represents an external input/output device connectable to the system bus 204;

In the main control unit 200, 201 is a control system CPU 300
202 is a random access memory (RAM), 203 is an input/output unit such as an operation input unit for operating the copying machine, 204 is a system bus, and 210 is an external Con)
A LAN interface section 211 and 212 is a control system CP that controls the interface between If-LANs n1 to nm.
These are a Tx address register and a Tx date register for U300 to send control information to an external controller via LAN interface section 210. Also 213,
214 is L A N /<S26 from an external controller.
These are an Rx address register and an Rx data register for the control system CPU 300 to receive data sent to the LAN interface section 210 via the Rx address register and the Rx data register. Also 3
00 is a control system CPU that executes each task process under the control of the Mokori CPU 201, and there are 8 in total from 310 to 380.
It consists of two CPUs. This control system CPU30
0 can be freely increased or decreased as needed. Each control system CPU also includes a dedicated reference register (REF register) 354, as shown in the CPUe350.
Timer/counter 352, comparator 353, control w4 circuit 3
It is equipped with 55. The constituent circuits in the system m section 200, the monitor CPU, the control system CPU 300, the LAN interface section 210, etc. are all constructed on one chip on the same semiconductor substrate.

This control system CPU 300 and monitor CPU 201 are RAM
202. In order to prevent contention when accessing the input/output unit 203, the time during which each CPU exclusively uses the system bus 204 is set in sequential time-sharing manner as shown in FIG.
The CPUs 310 to 380 operate clockwise cyclically in time division, and in this case, each CPU monopolizes the system bus 204 for 8 final seconds, making one revolution 80 seconds. During this time, the monitor CPUs 201 are operating in parallel. Therefore, in units of 80 seconds, CPUa
-h means they are running in parallel.

The LAN interface unit 210 includes a control register and a working register (not shown), and also has a function of controlling data communication with external controllers (221 to 223) etc. via the LAN bus 260 according to a predetermined protocol. There is. In this embodiment, in addition to the monitor CPU 201, there is also a small-scale control system CPU 300.
are assigned to each task processing execution level, and each CPU independently executes control processing. Monitor CPU20
1 performs start and stop control of task processing of each CPU group of the control system CPU 300, designates execution tasks, changes, etc., and executes processing according to the request only when there is a request from each CPU group. Execute.

Next, the relationship between each CPU group within the main control section 200 and the LAN interface section 210 will be described.

In FIG. 3, the CPU e 350 that executes the sequence control task will be described below as an example.

If the user inputs the copy start key and the conditions for copying are met at this time, a copy execution cycle begins.

In the case of a copying machine, a drum clock 206 generated by the rotation of the photosensitive drum 20 is counted, and various controls are executed in synchronization with this drum clock 206. This drum clock 206 is sequentially counted by a timer/counter 352 of the CPUe 350. A comparator 353 compares the counted value of the timer/counter 352 with a value read from the ROM 255 as necessary under the control of the control circuit 355 and set in the REF register 354, and if the two values match, Next control gl! ! ! + Execute the work.

Here, reading from the RAM 255 to the REF register 354 is performed by DMA.

FIG. 5 is a configuration diagram of each controlled object connected to the main control unit via the LAN bus 260 of this embodiment. Each controlled object of the copying machine is divided into 12 blocks, and the controller of each block is It is connected to the LAN bus 260. This L
The AN bus 260 is composed of two signal lines: an output signal line Tx 260a from the LAN interface 210 and an input signal line Tx 260b from the LAN interface section 210.

The main motor control 221 controls the main motor 221a of the copying machine. The main motor 221a drives the conveyance system of the photosensitive drum 20. In this example, a DC servo motor is used as the main motor. In addition, a timing clock pulse (drum clock) @206 is generated in synchronization with the rotation of the photosensitive drum 2o, and the LAN
The timer/counter (for example, 3
52). The optical system motor control 222 controls a document scan motor 222a, which is a servo motor, and a pulse motor 222b, which sets the magnification.The position control and speed control of these motors are controlled by the control system CPU 300 of the main control unit 200. Control is performed by this optical system motor control 222 based on the information. The setting of the variable magnification (reduction, enlargement, zoom) rate before the start of the copy operation by the pulse motor 222b is performed by the control system CP.
This is done based on instructions from U300.

This value is specified by the user from the operation unit.

The paper feed control 223 includes a DC motor 223a for rotating the paper feed roller 21 or 23 at a predetermined timing.
. The registration control 224 controls the registration motor 224a that drives the registration roller 30, and controls the transfer paper and the photosensitive drum 2.
When the user specifies duplex mode as the copy mode, the 0 duplex mode control 225 controls the image edge registration of the 0 side image, controls the paper deflection (loop), and detects double feeding (double sheet feeding). As explained above, the paper on which single-sided copying has been completed is sent to the intermediate cassette 26, and when the specified number of single-sided copies have been completed, the intermediate cassette 26
A guide plate control solenoid controls the intermediate paper feed roller motor 225a that drives the paper feed roller 25 that feeds the paper, feeds the transfer paper, and controls the directionality of the guide plate 34 in the duplex mode control 225. 225b and whether or not the paper bus has arrived in duplex mode (
Detects paper jams and presence/absence of paper).

EXP lamp control 226 Ti This controls the stabilization and dimming of the light amount of the halogen lamp 3, and detects the light amount of the halogen lamp 3 with the photosensor 226a. This photosensor 226a is arranged on the side of the halogen lamp 3, and constantly monitors the brightness of the halogen lamp 3. The fixing heater control 227 controls the heat generation temperature of the fixing heater 33a of the fixing unit 33, and detects the temperature by the thermistor 227 disposed near the fixing heater 33a, and adjusts the driving power of the fixing heater 33a according to this detected temperature. control. High pressure I
The E source control 228 measures the detected potential of the surface potential sensor 16 disposed near the surface of the photoreceptor drum 20, and adjusts the charged corona 13 so that the surface potential of the photoreceptor drum 20 is constant in bright and dark areas. , transfer corona 14. Bias power supply BI
Static elimination lamp control 2 that controls the voltage of 228a
Reference numeral 29 controls the amount of irradiation from the static elimination lamp 18 that eliminates static electricity from the surface of the photoreceptor drum.If a paper feed jam occurs in the transfer section, the image on the surface of the photoreceptor drum 20 is not transferred to the transfer paper. Does it exclude cases such as? The amount of irradiation from the 45 pump 18 is increased, and the machine is controlled to apply strong light onto the surface of the photosensitive drum 20.

The auto erase control 230 also controls the erase lamp 1 according to the paper size of the transfer paper to be copied and the magnification ratio.
5, the area to be lit is controlled to eliminate static electricity outside the image transfer area on the surface of the photoreceptor drum 20, and prevent toner from adhering to the non-transfer area. Low voltage control 231 is DC 2
The operation and display control 232, which performs stabilization control of the 4V power supply voltage and monitoring of abnormal values such as excessive current, controls the Manken machine interface and is controlled by the control system CPU 300.
Input/output section 203 via LAN interface section 210
The audio output from the audio output section 232a is controlled using manual key control from the keyboard 203a, display control of the display section 203b, and a built-in speech synthesizer.

This embodiment further includes a LAN bus 26 as an option.
There are four units as nearby devices that can be connected to 0. This is the charge counter 234. OCR10M
There are four units: an R reader (OCR) 235, an auto document tweeter (ADF) 236, and a sorter 237. Among these units, if controlling using only the LAN bus 260 causes a problem in response time, the main control Part 20
A new LAN interface is installed in the control system CPU 3 as a LAN interface exclusively for peripheral devices.
00 should be provided with two sets of Rx and Tx registers that can control two LAN interfaces.

In the following, the LAN transmission control section of each control section will be explained using the main motor control 221 shown in FIG. 5 as an example.

Each other control section is also the main motor control 22
The configuration and control are exactly the same as in No. 1.

FIG. 6 is a block diagram mainly consisting of the main motor control 221 (7) transmission control section. In the figure, 410 is a called detection section, and the called detection section 410 is connected to the LANz<S 260
TX life 260 & top (') Buffer register 411 that constantly receives communication data, address code register 4 that sets and holds address values specific to own control
12. Address code value in communication data stored in buffer register 411 and address code register 412
It consists of two registers 413 that compare the address code value set in
PLL control unit 2 outputs an interrupt request to buffer register 411, receives data of the transmission frame in which the address code addressed to the own control is set, and controls the drive of the main motor according to the received data.
21-2.

If there is data to be transmitted to the control system CPU 300 in response to the received data, the data to be transmitted is set in the transmission register 420, and the Rx of the LAN bus 260 is set.
The contents of transmit register 420 are transmitted on line 260b. This data to be transmitted is, for example, sent to the control system CPU 300.
When there is a request to send certain information, it sends the requested information (for example, control system status information), and when some kind of accident occurs, it notifies you of this abnormal state. There are cases. In this way, only when the called detection unit 410 (equipped in all controls) sends a transmission frame addressed to the own control, requests the control controller unit to receive communication data addressed to the own device. Therefore, the controller 5 does not need to monitor communication data addressed to other controls during that time, and can concentrate on its own control processing.

The control system CPU 300 also uses the Tx address register 211.
You only need to set the specified controller to be the control target, and you can concentrate on your own task processing without having to take into account interrupt request processing from other controllers, and the processing program procedure is simple and easy. It becomes highly reliable.

In FIG. 6, the control controller 221-1 is a PLL
The control unit 221-2 starts the main motor 221a.
The PLL control unit 221-2 outputs a stop signal and controls the rotation time of the main motor 221a, and the PLL control unit 221-2 controls this start/stop signal.
A speed control encoder 2 that rotates the motor according to a stop signal and outputs a pulse signal in response to the rotation of the motor.
A clock pulse signal for speed and position control is inputted from the controller 21b, and the rotational speed is kept constant and also output as position control data to the controller 221-1.

On the other hand, a drum clock pulse 206 generated in synchronization with the rotation of the photosensitive drum 20 is generated from an encoder 221C at the other end of the main motor 221a, and is connected to a separate signal line separate from the LAN bus 260. The signal is input to the main control unit 200, and is input to the timer/counter 352 and the like.

In the above explanation, the LAN bus 260 is used for transmission (
We have described an example using two communication media, one for Tx) and one for receiving (Rx), but even if one line is connected in a loop using the digit chain method, the same effect can be obtained as long as the protocol is defined. I can do things. An example of connection using this digit chain method is shown in FIG.

In this system, mutual communication is possible through one line instead of two lines for transmission and reception.

LAN interface section 210. The control via the LAN bus 260 will be explained using the flowchart of FIG. 8 showing the control operation for the EXP lamp control 226 as an example.

When the power of this embodiment is turned on, first the main control unit 20 is turned on at 31.
The monitor CPU 201 of No. 0 starts a predetermined control. Then, the monitor program shown in S2 is executed. In this state, for example, when a copy start key is input from the keyboard 203a, it becomes necessary to control the lighting of the halogen lamp (exposure lamp) 3, and the monitor CPU 20
1 controls the lighting of this halogen lamp 3 by the CPU 5350.
As shown in S3,
Start up 350.

At the same time, the other control system CPU 300 starts the main motor control 221, and starts the main motor 221a.
The drum clock 206 is sent accordingly. Then, the CPUe 350 uses the drum clock 20 sent by the timer/counter 352 in S4.
6 starts counting, and in S5, code data indicating the lighting timing of the halogen lamp 3 is read from the ROM 255 and set in the REF register 254. And continuation<S6. In S7, the comparator 353 reads this REF register 35.
4 and the count value of the drum clock pulse 206 of the timer/counter 352 and monitor whether the two values match. If the two values match, the process advances from S7 to 88, where E is sent to the Tx address register 211 to instruct the EXP lamp control 226 to turn on the halogen lamp 3.
The address code of the XP lamp control 226 is set, and control data (in this case, lighting control data and dimming data for the halogen lamp 3) is set in the Tx date register 212 when M<S9.

When the LAN interface unit 210 receives the transmission data in both the Tx address register 211 and the Tx date register 212, it executes transmission control to transmit both data from the SIO LAN bus 260.

The control data sent to this LAN bus 260 is
The called detection section of the lamp control 226 identifies the transmitted data as being addressed to its own control, and the halogen lamp 3 is lit according to the control data stored in the Tx day register 212, and the predetermined lighting is performed according to the dimming data. The brightness will be maintained. This brightness detection is performed by the photosensor 226a, and this brightness is detected by the photosensor 226a.
26a, the received light is converted into an electrical signal proportional to the intensity of the light, and this analog value electrical signal is converted from analog to digital, and this digitally converted value is compared with the sent dimming data. Control is performed to ensure that they match.

The CPUe 350, which has set the control data in the Tx data register 212 in S9, checks whether the task processing being executed in the Sll, that is, the control for the EXP lamp control 226 has been completely completed.

If it has not finished, return to S4 again and start drum clock 2.
06 continues, and the next timing code to be controlled is read out from the ROM 255 in step S5. Here, for example, code data indicating the extinguishing timing of the halogen lamp 3 is read out.

In this way, the task processing instructed by the monitor CPU 201 to the CPUυe 350 is executed sequentially, and when all processing is completed, the SLL proceeds to 312, and the CPUe 350 stops the operation by notifying the monitor CPU 201 of the end of the task processing. Then, it waits for activation from the monitor CPU 201.

As explained above, connection between the main control unit 200 and other controls can be made using only one or two communication media.

Furthermore, in this embodiment, the peripheral devices (234 to 237) can obtain an exclusive use of the LAN bus 260 by issuing an interrupt request to the LAN interface unit 210, in addition to other control controls. This interrupt request is made via the interrupt request signal line 265 shown in FIG.

In addition, each control unit and peripheral device can independently control the controlled system on a unit-by-unit basis, and standard control (photo sensor) is possible even if communication from the main control unit 200 is interrupted for a short time. It has become.

Along with this, the error between the two becomes large in devices with very high processing speeds, but in medium-speed a (for example, copying capacity of 40 sheets per minute or less), the effect can be almost ignored.

[Effects] As explained above, according to the present invention, a plurality of control units that independently control each of a plurality of control targets execute their control operations in a time-sharing manner. Since it is only necessary to concentrate on its own control, the processing program procedure becomes simple and highly reliable. Furthermore, since the processing is performed on a time-sharing basis, no processing conflicts occur.

Additionally, various optional expansion devices can be easily added to the standard device, and configuration changes can be easily accommodated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a control system in a conventional copying machine, FIG. 2 is a schematic sectional view of a mechanical part of a copying machine according to an embodiment of the present invention, and FIG. Fig. 4 is a diagram showing the operating procedure of each CPU of the main control section of this embodiment, Fig. 5 is a block diagram of each control system of this embodiment, Fig. 6 is a block diagram of the main motor control, and Fig. 7 is a block diagram of the main motor control. This figure is another LAN bus configuration diagram according to the present invention, and FIG. 8 is a control flowchart of EXP lamp control in this embodiment. In the figure, 20...photosensitive drum, 200...main control unit,
201.300...CPU, 210...LAN interface! , 221-237... each control section, 260... LAN bus.

Claims (3)

[Claims] (1) Consisting of a plurality of control units that independently control each of the plurality of control targets, and a monitor control unit that monitors the plurality of control units, and the plurality of control units control the control in a time-sharing manner. A control device characterized in that it executes operations in sequence. (2) The control device according to claim 1, wherein the plurality of control units periodically repeat their control operations. (3) The control device according to claim 1 or 2, wherein the plurality of control units and the monitor control unit are formed on the same semiconductor substrate.