JP2723543B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a plurality of switches each having a load to be controlled.
The present invention relates to an image forming apparatus including a CPU.

[Conventional technology]

2. Description of the Related Art In recent years, the multifunction of a copying apparatus has been advanced, and a plurality of CPUs for controlling the copying apparatus have been often used separately for, for example, controlling an optical system and controlling a copying sequence. By the way, if an error occurs in a program stored in the ROM in the CPU and the CPU runs away, the copying apparatus is in danger.

[Problems to be solved by the invention]

By the way, conventionally, for example, feedback control for maintaining a constant output with respect to a load variation of a copying machine (a light amount of a lamp, a temperature of a fixing heater, etc.) is used. However, since there is only one microcomputer (CPU) controlling it, if the CPU goes out of control, it does not know what the load will be like, and if the feedback signal is abnormal, It was impossible to judge this.

The present invention solves the above-mentioned drawbacks of the prior art, and provides an
It is an object of the present invention to provide an image forming apparatus capable of easily and accurately detecting an abnormality due to a runaway of a CPU and preventing a failure due to a malfunction before it occurs.

[Means for solving the problem]

An object of the present invention is to provide a first CPU that performs feedback control on a first load, a second CPU that operates in cooperation with the first CPU and controls a second load, and the first CPU. The data output from the load to the first and second CPUs
And a means for transmitting data input by the input means to the other CPU, wherein the first and second CPUs receive data input from the first load. Is determined to be a normal value, and whether data input from the first load matches data received from the other CPU or not is compared with each other. This is achieved by detecting

[Action]

In the present invention, a plurality of loads are monitored by a plurality of CPUs,
The motors are compared with each other, and when there is a difference between the data, it is determined that there is a load or CPU abnormality or a communication system between the CPUs has an abnormality, and the operation thereof is prohibited.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is an internal mechanism diagram of the copying apparatus according to one embodiment of the present invention. A contact glass 40 on which an original is placed is provided on the upper surface of the copying apparatus, and an optical scanning system is provided below the contact glass.

The optical scanning system includes an illumination 41, a first mirror 42, and a second mirror 4.
3, a third mirror 44, a zoom lens 45, a fourth mirror 46 and the like are provided. The optical scanning system is mechanically driven to scan in the sub-scanning direction, that is, the left and right direction in the drawing, while irradiating the photosensitive drum 47 with light corresponding to a document image. In this example, the magnification of the original image and the copy image in the main scanning direction, that is, the direction perpendicular to the drawing, is adjusted by adjusting the illumination distance of the zoom lens 45, and the sub-scanning direction is adjusted by adjusting the sub-scanning speed of the optical scanning system. The magnification of the original image and the copy image is adjusted. Around the photoconductor drum 47, a charging charger 48, an eraser 49, a developing device 50, a transfer charger 51, a separation charger 52, a cleaning unit 53, and the like are provided in the order of processes. Two paper feeding systems are provided, and copy sheets are supplied by paper feeding rollers 56 and 57 from one of cassettes 54 and 55 selected. Further, a double-sided tray 58 is provided, and when performing back side copying, a copy sheet is supplied from the double-sided tray 58. Reference numeral 59 denotes a two-sided paper feed roller. Reference numeral 60 denotes an operation board, 61 denotes a fixing unit, 62 denotes a path switching mechanism, and 63 denotes a transport mechanism.

Next, an outline of the copy process will be described. The photosensitive drum 47 rotates clockwise in FIG. 2, and the surface is uniformly charged to a predetermined high potential. When the charged surface is irradiated with light from the optical scanning system, the potential changes according to the intensity of the light. Since the light emitted from the optical scanning system corresponds to the original image, a potential distribution corresponding to the original image, that is, an electrostatic latent image is formed on the surface of the photosensitive drum 47. Photoconductor drum 47
When the portion on which the electrostatic latent image is formed passes through the developing device 50, the toner is attracted to the photosensitive drum 47 according to the potential distribution, whereby the toner image (visible image) corresponding to the electrostatic latent image is formed. ) Is formed. The copy sheet is fed from the selected paper feeding system at a predetermined timing to the photosensitive drum 47 on which the visible image is formed, and overlaps the visible image. Then, the visible image is transferred to a copy sheet by the transfer charger 51. The copy sheet on which the visible image has been transferred is separated from the photosensitive drum 47 by a separation charger 52 and sent out to a transport section. Then, the visible image is fixed on the copy sheet by the fixing unit 61 provided in the transport unit. In the case of the single-sided copy mode, the copy sheet having been fixed passes through the path switching mechanism 62 and is immediately discharged in the direction of arrow A.
The transport direction of the copy sheet is reversed by the path switching mechanism 62, and the copy sheet passes through the transport mechanism 63 and is stored in the double-sided tray 58.

An operation board 60 is arranged on the upper surface of the copying machine. Further, an automatic document feeder (not shown) is mounted above the contact glass 40 of the copying machine, and a sorter (not shown) is mounted near the discharge port.

FIG. 3 shows the appearance of the operation board 60 of the copying machine. Referring to the figure, the operation board 60 has a program key 70 for storing and recalling a program, a program display 71 indicating that the program is being used, and setting and setting of an interrupt copy.
Interrupt key 72 for canceling, interrupt display 73 indicating the interrupt copy status, confirmation of the number of copies being copied, confirmation of the number of copies to be used during size change / program, key 74 for setting the number of copies, size change of the size, and setting of the program Numeric keypad 75 to be used, display panel 76 for displaying various information, double-sided key 77 for double-sided copy, double-sided display 78 for displaying the status of double-sided copy, binding margin used when creating a binding margin (margin) for copying Adjustment key 79, binding margin display 80 to display binding margin dimensions, DF mode key 81 to use when performing unified paper size or automatic paper selection, unified size display 82 to show the unified size when using DF, when using DF Automatic paper selection display 83 indicating the automatic paper selection status, sort display 84 indicating the sort status when the sorter is used, stack display 85 indicating the stack status when the sorter is used 85, and setting of the sorter mode -Setting of release and stack mode-Sorter key 86 used for release, ADF display 87 showing ADF (fully automatic) mode, SADF display 88 showing SADF (semi-automatic) mode, ADF mode for document feeder, SADF mode DF key 89 used to set the size of the original, Dimension input display 90 illuminated when entering the dimensions of the original, Specified dimension display 91 illuminated when entering the specified dimensions, Used to select the copy magnification by dimension Key 92, a key 93 used to select the copy magnification in 1% increments, a continuous page display 94 indicating the continuous page copy status, and a button used to automatically copy a two-page spread original one by one. Page continuous key 95, original size selection key 96 used to determine the copy magnification based on the original size and paper size, reduced key 97 used for reduced copy, Large key 98, magnification key 99, paper selection key used when copying sheet selection to be used when returning the magnification copy
100, density adjustment key 101 used to adjust the density of the copy image, automatic density key 102 used to set and cancel the automatic density adjustment function, change the number of sets, interrupt repeat copying, cancel program protection, etc. Clear stop key 103, Start key 104 to start copy operation, Preheat mode / mode clear key 105 used to return each mode to the standard mode or to switch between the preheat state and the normal state, Preheat indicating the preheat state A display 106 is provided.

Original and paper (copy sheet) in unified size mode
The copy magnification is automatically set according to the size (for example, A4, B5, etc.). In the automatic paper selection mode, the paper feed system is automatically selected according to the document size and the copy magnification. The binding margin adjustment is a function that shifts the correspondence between the position of the document image and the position on the copy sheet in the sub-scanning direction.
One of five levels of 10, −5, 0, +5 and +10 (mm) can be specified. The binding margins for the front and back sides of the copy sheet can be independently performed.

To set the dimension scaling mode, press the dimension scaling key 93, specify the copy size using the numeric keypad 75, press the number confirmation key 74, press the dimension scaling key 93 again, and then press the numeric keypad 75. Specify the copy size with and press the number confirmation key 74.

With this operation, the copy magnification is automatically set by calculating the original and the copy size. In this example, the adjustment of the copy density is performed in seven steps.
The density can be adjusted step by step in a darker or lighter direction.

FIG. 4 shows a configuration diagram of a control circuit of the copying machine. As can be seen from the figure, in this example, (1) a CPU that performs display and key input processing of the operation board 2 and controls the heater control unit 3 and the lamp control unit 4
1, (2) CPU 7 for controlling the scanner motor 5 of the optical system and the stepping motor 6 for the lens / mirror, (3) ON / OFF of the solenoid control unit 8, the relay control unit 9, the motor control unit 12 of the clutch, etc. The copying operation is controlled by three microcomputers, a main control CPU 13 which controls the input processing of the sensor unit 10 and the sequence control of the high voltage power supply unit 11.

Next, FIG. 1 shows a connection diagram of each microcomputer for realizing the present invention.

In this figure, only the signals according to the present invention are shown, and the others are omitted.

Microcomputer 7810 (CPU1) for operation control board C
Are used for fixing heater control, lamp control, communication control, and operation unit control. PA ₀ and PA ₁ are output ports, PA ₀ is used as a lamp ON signal, and PA ₁ is used as a fixing ON signal. AN ₀ and AN ₁ are analog inputs for the A / D converter, which set the lamp voltage of the halogen lamp 16 to AN ₀ and the fixing thermistor 17
And Gyotsu a fed back control of the fixing temperature by connection to AN _1. T _x D serial communication data, R _x D is the serial received data, RESET denotes a CPU reset signal. Fixing ON signal,
The lamp ON signal is input to the AC drive plate 14, and the drive plate 14 turns the actual heater 15 and the lamp 16 on / off.

Main control board A is also micro computer 7810
(CPU 13), and performs copy sequence control and the like. AN ₀ and AN ₁ are used as inputs for the lamp voltage and the fixing temperature, similarly to the operation unit. T _x D, by switching the control signal R _x serial data D is also the same as the operation unit Te SEL Niyotsu are Gyotsu switching communication of the operation control board C and the optical control plate B. In this case, communication with the optical control board B is possible when SEL is “H”, and communication with the operation control board C when SEL is “L”.

PC3 is used as a soft reset signal at the output port. This signal is ORed with the negative logic of the output of the reset IC 17 and connected to the resets of the CPUs 13, 7, 1 of the control boards A, B, C.

Description of the optical control plate B is omitted because it is not directly related to the present invention.

Next, the procedure of each control board A, B, C data communication will be described with reference to FIG. The control board A starts communication. First, the SEL signal is set to “H” to transmit data to the control board B. Then, a reception interrupt INTSR is generated in the control board B, the received data is fetched in the interrupt processing routine, and then the data is transmitted to the control board A. In the control board A, a reception interrupt INTSR occurs upon reception of the data, and the received data is fetched in the same processing routine, the SEL signal is set to “L”, and the data is transmitted to the control board C. Then, a reception interruption occurs in the control board C, and the data is transmitted to the control board A as in the case of the control board B. The control board A again generates a reception interrupt, and then sets the SEL signal to “H” to transmit data to the control board B. Hereinafter, this is always repeated.

Next, a program for realizing the present invention will be described based on a flowchart.

FIG. 6 shows a main routine of the main control board A.
After the power is turned on, the memory, each port, etc. are initialized (1-1), and then the SEL signal is set to "H" (1-2).
Data is transmitted from the optical system control plate B to the optical system (1-
3). Next, a reception interrupt is permitted (1-4) and a main processing routine (copy sequence control and the like) is executed (1-4).
5) After that, the fixing abnormality check and the lamp abnormality check are performed (1-6, 1-7), the interruption is permitted again (14), and the procedure of the main processing routine (1-5) is repeated.

FIG. 7 is a reception interrupt processing routine of the main control board A. This interrupt is generated when the reception of data from the optical control board B or the operation control board C is completed. First, reception processing (data storage, etc.) is performed (2-
1) Then, from the determination of the SEL signal (2-2), if "H", it is set to "L" (2-3), if it is "L", it is set to "H" (2-4). C or transmit data to the optical control board B (2
−5, 2−6), return.

FIG. 8 is a fixing check routine of the main control plate A. First, the A / D conversion data by the fixing thermistor 17 is read, and the temperature is measured (3-1). If the temperature is abnormal (Y in 3-2), abnormal processing is performed (3-3), and PC3 is set to "L" (3-4). This signal is applied to C of each control board A, B, C
It is used for resetting PU13,71, and each CPU13,7,1 is restarted. If there is no temperature abnormality (N in 3-2), it is determined whether the heater 15 is ON (3-5). If the temperature is ON, the heater 15 is sent in advance from the operation unit control plate C. A comparison is made between the existing fixing temperature data and the temperature read by itself (3-6). If they are different (N in 3-7), one of the CPUs is determined to be abnormal, and the same error processing is performed to set PC3 to "L".

FIG. 9 shows a lamp abnormality check routine of the main control plate A. This routine measures and checks the lamp voltage, and is the same as the heater temperature check in FIG. That is, “fixing” is replaced by “lamp” and “temperature”
Is replaced with "voltage", steps 4-1 to 4-7 correspond to all steps 3-1 to 3-7.

FIG. 10 shows a main routine of the operation control plate C. After the initialization (5-1), the operation control (5-2) and the AC control (5) are performed.
-3) and the like, and a fixing abnormality check (5-4) and a lamp abnormality check (5-5) are performed. These checks are exactly the same as the checks (FIGS. 8 and 9) of the main control plate A except that the operation of the PC 3 is eliminated, and therefore the description thereof is omitted.

FIG. 11 shows a reception interrupt processing routine, and the reception processing (6
-1) After that, the data is transmitted to the main control board A (6-2), and the process returns.

The normal operation can be returned by resetting each of the CPUs 1, 7, and 13 by judging the lamp abnormality and the fixing heater abnormality by the operation as described above.

Further, by adding latch means to the reset circuit, it is possible to keep the copying operation prohibited.

〔The invention's effect〕

As described above, according to the present invention, it is possible to easily and accurately detect an abnormality in a load or a CPU or an abnormality in a communication system between CPUs, and prevent a failure or a disaster due to a malfunction from occurring.

[Brief description of the drawings]

FIG. 1 is a diagram showing a connection relationship between CPUs, which are main parts of the present invention, FIG. 2 is an internal mechanism diagram of a copying apparatus according to an embodiment of the present invention, FIG. FIG. 4 is a control block diagram of the copying machine, FIG. 5 is an explanatory diagram for explaining a procedure of data communication between CPUs, FIG. 6, FIG. 7, FIG.
FIG. 10, FIG. 10 and FIG. 11 are flowcharts of the main routine and the interrupt routine according to the control of the present invention. 1,7,13 …… CPU.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location G06F 15/16 460 G06F 15/16 460D

Claims (1)

(57) [Claims] A first CPU that performs feedback control on a first load; a second CPU that cooperates with the first CPU and controls a second load; Means for inputting data output from the load of the first and second CPUs in parallel to the first and second CPUs;
And the first and second CPUs determine whether the data input from the first load is a normal value,
An image forming apparatus comprising: comparing whether data input from the first load matches data received from the other CPU; and detecting an abnormality in a communication system based on the comparison result.