JPS6318230B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control system for a copying machine using a plurality of microcomputers.

In recent years, due to rapid advances in semiconductor manufacturing technology, central processing units (CPUs) with arithmetic and judgment functions, random access memories (RAMs) for data storage,
Microcomputers, in which a read-only memory (ROM) for storing processing programs, an input/output control unit, etc. are built into a single LSI chip, are now available on the market at low cost. Therefore, it became possible to mount this one-chip microcomputer on a copying machine and efficiently perform its complex control.

However, in the past, a single microcomputer was used to fetch data, perform calculations and judgments, and control the copying machine, which made high-speed processing impossible and the programs complicated, especially for high-speed, multi-functional copying machines. It was difficult to control accurately.

Therefore, this invention uses two inexpensive one-chip microcomputers, one of which is responsible for data fetching and direct control and treatment of the copying machine, and the other is dedicated to arithmetic processing and judgment. The present invention provides a control system for a copying machine in which the microcomputer of the former is instructed to carry out necessary processing based on the result by an interrupt, and the microcomputer of the former is made to sequentially fetch various data by time division. , which enables high-speed and highly reliable control of copying machines.

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a configuration diagram showing an example of a control system for a copying machine according to the present invention, in which 1 is a copying machine to be controlled, and 2 is a block diagram for outputting signals to various devices that control the copying machine 1 to control and take measures. A first microcomputer (hereinafter referred to as μcomputer), which fetches various data and stores it in an external memory 3, accesses data stored in the external memory, performs arithmetic processing and judgment, and The second .mu.computer interrupts the first .mu.computer 2 and instructs the first .mu.computer 2 to perform processing on the copying machine 1 based on the result. 5 to 10 are various sensors, in this example, the toner concentration of the copying machine 1;
The internal temperature, humidity, photoreceptor surface potential, exposure illuminance, and photoreceptor bias potential are detected as analog signals and input to channels 0 to 5 of the modular multiplexer 11, respectively.

This modular multiplexer 11 sequentially switches one of the input signals from channel 0 to channel 5 in response to a timing signal a sent from μcomputer 2 and outputs the same. 12 is an AD converter which decomposes the analog signal b output from the modular multiplexer 11 into bit patterns, converts it into a digital signal, and inputs it to the μcomputer 2. The μ computer 2 fetches the data based on this digital signal and immediately stores it in the external memory 3.

The operations of the first .mu.computer 2 and the second .mu.computer 4 in the copying machine control system configured as described above will be explained with reference to the control flow diagram of FIG.

First, in step I, data converted into a digital signal by the AD converter 12 is fetched into the first μcomputer 2. In step, the μcomputer 2 stores this data in the external memory 3. In step, the μcomputer 2 issues an interrupt signal d to the μcomputer 4 to interrupt and instruct it to access. By this,
In step V, the second μcomputer 4 accesses data in the external memory 3 in the interrupt processing routine, and in step V performs arithmetic processing and judgment based on this data. As a result, the data is corrected depending on the temperature and humidity conditions inside the machine. For example, if it is necessary to replenish 2g of toner, an interrupt signal e is sent to the first μcomputer 2 in a step.
An interrupt is generated by μcomputer 2.
Processing is done in the interrupt handling routine of
An output signal is given to replenish 2g of Nato.

In order to perform several different processes in response to such interrupts, an interrupt reception register is provided on the interrupt line of the μcomputer 2, and a ROM containing a processing program corresponding to the assignment is installed.
By writing the interrupt into the microcomputer 4, different processing can be performed depending on which interrupt is generated by the μcomputer 4. For example, if the interrupt processing of the μ computer 2 is set as follows, six types of processing will be possible.

Interrupt processing 1 Nato density control 2 Temperature control 3 Photoconductor surface potential control 4 Photoconductor bias control 5 Humidity control 6 Photoconductor fatigue level detection control Note that the targets and types of data detected by the sensors 5 to 10 may be changed as appropriate. subject to change and increase;
A modular multiplexer 11 having an input channel corresponding to the type may be used. Furthermore, the types of interrupt processing performed by the μ computer 2 are not limited to the six types listed above.

As described above, according to the present invention, various controls necessary for a copying machine are performed by switching detection data from a large number of analog signals using a modular multiplexer, time-sharing the data, and inputting the data to an AD converter. This is done by using a μcomputer for data fetching, which fetches the data, and a μcomputer for calculations and judgments, so a wide variety of data can be input using an inexpensive, one-chip μcomputer, resulting in high speed and reliability. It is extremely effective as a control system for high-speed, multifunctional copying machines.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram showing an embodiment of the present invention, and FIG. 2 is a control flow diagram for explaining the operation of the embodiment of FIG. DESCRIPTION OF SYMBOLS 1... Copying machine, 2... First microcomputer, 3... External memory, 4... Second microcomputer, 5-10... Various sensors, 11... Modular multiplexer, 12... A-D converter.

Claims (1)

[Claims] 1 A sensor that detects various data from a copying machine as an analog signal, a first microcomputer that controls the copying machine, and a sensor that inputs the analog signals detected from each of the sensors and outputs the data from the first microcomputer. a modular multiplexer that sequentially switches and outputs one of the input signals according to a sent timing signal; an A-D converter that converts an analog signal output from the modular multiplexer into a digital signal; a memory for storing data converted into digital signals by the A-D converter fetched by the microcomputer 1; and a memory for accessing the data stored in the memory to perform calculation processing and judgment. When the first microcomputer fetches data and stores it in the memory, the second microcomputer fetches data and stores it in the memory.
The second microcomputer instructs the second microcomputer to access the copying machine by interrupting the first microcomputer, and the second microcomputer instructs the first microcomputer to perform the processing to be performed on the copying machine based on the result of the arithmetic processing and determination. A control system for a copying machine using multiple microcomputers.