JPH0140982B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for controlling a copying machine that advances a sequence by counting pulses generated as a photoreceptor is driven.

[Conventional technology]

2. Description of the Related Art Conventionally, copying apparatuses have been controlled by counting pulses generated as a photoreceptor is driven to advance a copying sequence.

Incidentally, in the case of such a device, if there is an abnormality in the pulse, it will affect the sequence control, so it is important to determine whether the pulse is normal or not. Moreover, most pulse abnormalities are caused by some kind of abnormality in the operation of the photoreceptor, so if these pulse abnormalities are not dealt with appropriately, even more serious problems will occur in the entire device. It turns out. For example, if the generated pulse is abnormally short compared to normal, there is a possibility that the photoreceptor is being driven at a faster speed than usual, and if the sequence continues as it is, jams in the transfer paper will occur. If the pulse does not arrive or is abnormally long, there is a possibility that the photoreceptor has stopped for some reason, and if power is still being supplied to the drive motor, the motor may be damaged.

In order to detect this pulse abnormality, in the conventional copying apparatus described above, it is necessary to separately create a reference pulse and compare it with the pulse to be determined. There are drawbacks such as the circuitry for making it is complicated and expensive, two circuits are required to determine the length of the pulse width, and it is difficult to adjust the reference value of the pulse width.

Furthermore, if there is a deviation in this reference pulse, there is a drawback that even if the pulse is normal, that is, the copying machine itself is normal, the determination will be abnormal.

Further, if the pulse to be determined is immediately determined to be abnormal if it is not in the reference state, it will also be determined to be abnormal even if the rotational speed slightly changes from the reference state due to deterioration of the photoreceptor drive motor or the like. However, if the copying sequence is advanced by counting pulses, even if the pulses are slightly out of order, the deviation can be compensated for by adjusting the copying sequence accordingly.

[Purpose of the invention]

This invention was made to solve the above-mentioned drawbacks, and a copying machine equipped with a microcomputer is provided with a pulse generator that generates pulses synchronized with a drive motor for rotationally driving a photoreceptor. The copying sequence is controlled by counting with a microcomputer, and the photoconductor drive status can be determined with a simple configuration by checking whether the pulse status is within the permissible range of copying operation control and counting the pulses. It is an object of the present invention to provide a pulse counting method for sequence control of a copying machine that can quickly detect and respond to an abnormality and can also respond to a certain degree of change in the rotational speed of a photoreceptor.

〔composition〕

FIG. 1 shows the general architecture of a microcomputer used in this invention. A central processing unit (CPU) 1 is composed of an arithmetic unit (ALU) 5, an index register and an accumulator 6, a program counter and a stack pointer 7, an instruction register and a decoding control unit 8. 2 is a read-only memory (ROM), 3 is a random access memory (RAM), and 4 is an input/output control unit (IOC). Note that the ROM2, RAM3, and IOC4 are also integrated with the CPU1 and are called a single-chip microprocessor. The program is stored in ROM 2, and its address is specified by the program counter 7. The instruction read from the ROM 2 is set in the instruction register No. 8, and the instruction code is decoded by the decoding control section. All operations are performed using an accumulator of 6 as one operand. In other words, when an arithmetic instruction is set in the instruction register 8, the operand is read from the RAM 3 by the address field of the instruction, the operation between this and the contents of the accumulator 6 is executed in the arithmetic unit 5, and the result is stored in the accumulator. be done. In the case of an input/output command, an external device is selected by the input/output port through the input/output control unit 4, and the contents of the accumulator 6 are transferred to the external device, and the data flag is transferred from the external device to the accumulator. Index register 6 is used for address modification, and index register 7 is used for address modification.
The stack pointer is also used for subroutine nesting.

FIG. 2 specifically shows the pulse generator portion of the copying machine. Engagement gear device 1 by drive motor 9
Rotate the pulse generator 11 through 0.
The pulse generator 11, as shown in FIG.
A large number of slit-like through holes are formed and a light emitting diode 12 is formed.
A pulse is generated by the combination of the phototransistor 13 and the phototransistor 13 (INP1). The period of this pulse is normally 10 milliseconds, and one pulse is generated per 1 degree of rotation of the photosensitive drum 14. Figure 4 is a side view of Figure 2, where INP0 is the copy start switch, INP2 is the paper discharge detection switch, INP3 is the home position switch for the document table 15, INP4 is the paper out detection switch, 16 is the paper feed cassette, 17 18 indicates a fixing heater, and 18 indicates a copy stocker.

FIG. 5 is a general flowchart showing the steps of the copying machine. First, when you turn on the power, it enters the initial check routine. Here, it is checked whether the copying machine is in the initial state as follows. For example, if the document table 15 is stopped midway, it is returned to the home position. If there is previously copied paper in the machine, the motor 9 is rotated to eject it out of the machine. It checks whether there is paper in the paper feed cassette 16, whether there is toner, whether the temperature of the fixing heater 17 has reached a predetermined level, whether there is any abnormality with the exposure lamp, etc. If there is no abnormality, the operator inputs data such as the number of copies, and the copy start state is entered. When copying is started, copying is completed through a predetermined copying process, but after copying one sheet, it is checked whether it is a repeat or not, and if it is a repeat, a condition check is entered. At this point, the presence or absence of supplies is mainly checked in order to enter the re-copy cycle. In other words, is there paper or toner?
Check whether the photoconductor has reached the end of its life.
Prepare for the next copy. If there is an abnormality in these, a predetermined abnormality display will be displayed and the machine will be stopped.

FIG. 6 is a flowchart of the copying operation of the present invention. However, the initial check routine and condition check routine are omitted.
Check whether the copy start switch of INP0 was pressed in STEP1. Specifically, as shown in Figure 1.
Data is transferred from the input port (INP) of IOC4 to accumulator 6, and whether the copy start switch is pressed or not depends on whether the bit corresponding to INP0 among the multiple bits of accumulator 6 is 1 or 0. I am deciding whether

The same applies to INP1, INP2, etc. that appear in the following explanation, and the CPU 1 detects the external state depending on whether the corresponding bit of the accumulator is 1 or 0. In the following explanation, each piece of data is referred to as a flag, and a state in which the corresponding bit is 1 means that a flag is set (or on).
A state in which the corresponding bit is 0 is said to be not set (or off).

If the copy start switch is pressed in STEP 1, set each load in STEP 2 to STEP 6, and in STEP 7 put 10 into PGCTR (pulse generator counter register, for example, C register) of CPU 1.

This PGCTR is subtracted by 1 each time one pulse is generated from the pulse generator 11. The command “PGCTR:0” in Figure 6 is PGCTR
Subtract 1 from , and if the result is 0, proceed to the next step (the step indicated by "=").
If it is not 0, this is a command to return to the previous step (the step indicated by "≠").

As described above, the pulse period from the pulse generator 11 is normally 10 milliseconds, and the photosensitive drum 14 rotates 1° per pulse.

STEP8 is a subroutine for checking the pulse status whose details are shown in Fig. 7, and STEP13,
The same goes for 17, 21, 25, 29, 33, 37, 42, 51, 55, and 62.

This pulse state check will be explained in detail later.

After counting 10 pulses in STEP9,
In STEP 10, the exposure lamp (halogen lamp) is turned on, and in STEP 11, the start solenoid is turned on, and scanning of the document table 15 begins.

45 pulses are counted in STEP12 to STEP14, and when the process proceeds to STEP15, the photoreceptor 14 has advanced by 55 degrees.

In STEP 15, the out-of-paper detection switch INP4 checks whether there is any paper in the paper feed cassette 16, and if the out-of-paper flag is set, out-of-paper processing is performed.

10 pulses are counted in STEP16-18.

In STEP 19, it is checked by INP3 whether the document table 15 is away from the home position, and if the flag is on, it is not far away, so an abnormality is determined and the machine is stopped.

If it is off, it is normal, so next step 20~
Count 35 pulses at step 22 and turn off the start solenoid at step 23.

Next, count 150 pulses in STEP 24 to 26, and turn on the transfer corona in STEP 27.

Count 50 pulses again in STEP28-30, and turn on the 500-sheet counter in STEP31. this
Although the 500-sheet count is not shown in Figure 4, it counts the total number of copies made by the photoconductor installed in the copier every time an on signal is received. A flag indicating this is turned on and output to the IOC 4. At the time of STEP 31, the copying operation has not yet been completed, but the photoconductor has already been copied once.

In STEP32 to 34, count 60 pulses,
Turn off the charged corona in STEP35. Up to this point, the photoreceptor 14 has rotated 360 degrees, that is, one rotation.

Next, count 25 pulses in STEP36-38, turn off the halogen lamp in STEP39, and then turn off the halogen lamp in STEP40.
The return solenoid is turned on to reverse the moving direction of the document table 15.

Count 125 pulses in STEP41-43,
When the photoreceptor 14 has rotated 510 degrees, the paper discharge detection switch INP2 performs paper discharge detection STEP44. This means that the copied paper is naturally on the verge of paper discharge detection at this timing, and therefore, if the paper discharge flag is not set at this time, it will be determined that there is a jam and JAM processing will be performed.

Furthermore, in STEP45, the COPYCTR (copy counter, eg, E register) of CPU1 is incremented by +1.

In STEP 46, the data on the number of copies (repeat number) entered before copying starts and
The count number of COPYCTR is compared, and if they match, it means that copying has finished, so in STEP 47, the green lamp is lit to prepare for restarting. If they do not match, that is, if the input data is larger, this STEP 47 is not executed.

In STEP 48, check the 500 sheets detection flag explained in STEP 31, and if it is on, proceed to STEP 49.
The photosensitive drum 14 is displayed to prompt the operator to replace the photosensitive drum 14.

In STEP50-52, count 100 pulses,
Turn off the transfer corona in STEP53.

Next, in STEPs 54 to 56, 120 pulses are counted, and when the photoreceptor drum 14 has rotated 730 degrees,
In STEP 57, it is detected by INP3 whether the document table 15 is at the home position. If the flag is not raised at this time, it means that the document table 15 has not returned to the home position, and the machine is stopped as an abnormality has occurred in the machine. If the flag is set, turn off the return solenoid in STEP58.

Next, in STEP 57, paper out detection is performed in the same manner as in STEP 15, and in STEP 60, it is checked whether the END flag is set. This END flag is set if the input data and COPYCTR match in STEP46, indicating the end of copying. This END flag is not input via the IOC4 like INP0, INP1, etc., but is a software flag inside the microcomputer.

If the END flag is not set, return to STEP 2, but if it is, while counting 350 pulses in STEP 61 to 63, clean the photoreceptor drum 15 using the static elimination corona and the static elimination lamp for approximately one rotation of the photoreceptor drum 15. Then, in STEP 64, the static eliminating corona and static eliminating lamp are turned off, and in STEP 65, the photosensitive drum drive motor is stopped, and the series of copying operations is completed.

Next, FIG. 7 mentioned above will be explained.

In STEP101, the rising edge of the INP1 pulse is detected. The rising edge of the pulse means that the flag of INP1 changes from off to on. Therefore,
In STEP 101, the state of the flag at that moment is compared with the state of the flag one time before to see if the flag has changed from off to on. In FIG. 7, this operation is representatively shown by CLP:1, that is, an instruction to check whether the flag is 1 (on).

If the rising edge of the pulse cannot be detected in STEP101, set a 1 millisecond timer in STEP102, load the value 20 into the A register in STEP103, increment the B register by +1 in STEP104, and compare both AB registers in STEP105. conduct.

If A=B, stop the machine; if not, return to STEP101 and detect the rise of the INP1 pulse again.

That is, in this example, STEP101 to STEP105
Repeat the above loop 20 times, and if the pulse does not rise within 20 milliseconds, it is determined that there is an abnormality and the machine is stopped.

It goes without saying that the contents of the B register must be set to 0 before entering this loop.

If the rising edge of the INP1 pulse is detected in STEP101, set a 2 millisecond timer in STEP106, and when this timer times up,
Check the INP1 flag again in STEP107.

If the flag is off at this time, it means that the pulse whose rise was detected in STEP 101 fell within 2 milliseconds, so it is determined that the pulse width is abnormally short and the machine is stopped.

If the flag is on in STEP107, STEP108
Set a 5 millisecond timer with
Look at flag 1.

In STEP109, if the flag is off, it is assumed to be normal and the process moves to the next step (for example, STEP9), but if the flag is on, the value 4 is loaded into the A register in STEP110, and the B register is incremented by +1 in STEP111. , AB in STEP112
Compare both registers.

If A=B, stop the machine; if not, return to STEP 108 and check the INP1 pulse status again.

That is, in this example, STEP108 to STEP112
By repeating the loop up to 4 times, the pulse is 20 milliseconds, and the time from detecting the rising edge in STEP101 is 22 milliseconds in total, including the 2 milliseconds in STEP106.
If it does not come down after milliseconds, it is determined that there is an abnormality and the machine is stopped.

Note that the content of the B register must be set to 0 before entering this loop, as in the loop from STEP101 to STEP105.

In this way, the pulse status check routine shown in Fig. 7 detects when a pulse does not arrive (does not rise) for a predetermined period of time, when a pulse that has risen falls in a short period of time, or when a pulse does not fall even after a predetermined period of time has elapsed. When there is no pulse, it is determined that the pulse is abnormal, that is, the machine is abnormal, and the machine is stopped.

The abnormal state of the pulse determined in the pulse state check routine of FIG. 7 will be explained with reference to FIG.

FIG. 8a shows the state of the pulse during normal operation, the period of which is 10 milliseconds, and the period when the flag is on is 5 milliseconds. However, this value is not strict, and there is a certain tolerance range. This is because, as shown in Figure 6, the copy operation is controlled by counting the pulses from the pulse generator 11, so even if there is a slight deviation in the pulses, the overall control is maintained. This is because it can be adjusted accordingly.

However, even if there is a permissible range, if the deviation is too extreme, copy sequence control cannot be performed normally, and the photoreceptor drive motor may stop.

Figure 8b shows a state where the pulse flag is set for a short time, which corresponds to steps 106 and 107 in Figure 7.
detected.

In this example, the on time of the flag is originally 5 milliseconds, but a 2 millisecond timer is set in STEP 106 because it is possible to continue controlling the copy sequence if the flag is on for at least 2 milliseconds.

Figure 8c shows a state in which the pulse flag remains on for too long, which is caused by STEP 108 in Figure 7.
Detected at ~112.

In this case, contrary to FIG. 8b, the present invention sets a 5 millisecond timer in STEP 108, assuming that even if the flag ON time, which is 5 milliseconds, continues longer than that, control is possible up to 22 milliseconds. Then, the loop from STEP108 to STEP112 is repeated four times, waiting for the flag to turn off.

This 22 milliseconds is the total time of four 5 milliseconds in STEP108 and 2 milliseconds in STEP106.

FIG. 8d shows a state in which the pulse does not rise for a long time, and this is detected in steps 101 to 105 in FIG.

That is, in this example, if the pulse rises within 20 milliseconds after the start of detection of the rise of the pulse, it is possible to continue copy sequence control.

〔effect〕

As explained above, according to the present invention, in order to control the sequence of a copying machine, the sequence is advanced by counting pulses generated by a pulse generator interlocked with a photoreceptor drive motor using a microcomputer. Each time the pulse is counted, if the pulse does not come, is abnormally long, or is abnormally short, it is determined that there is an abnormality and the copying machine is stopped, so the configuration is simpler than the conventional one. However, any abnormality in the drive of the photoreceptor that may occur can be detected in the form of pulse abnormality, and countermeasures can be taken promptly.

Furthermore, when checking for pulse abnormalities, each of the three abnormalities mentioned above has its own tolerance range, so even if slight fluctuations in the rotational speed of the photoreceptor occur, the copying will not become impossible. You can take it.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a configuration diagram of a microcomputer used in this device, FIGS. 2 to 4 are explanatory diagrams showing particularly the pulse generator part of this device, and FIG. 6 is a general flowchart showing the steps of the copying machine, FIG. 6 is a flowchart of a copying operation, FIG. 7 is a flowchart of a pulse state check routine, and FIG. 8 is a diagram showing each pulse state. 1...Central processing unit, 2...Read-only memory,
3... Random access memory, 4... Input/output control unit, 9... Motor, 11... Pulse generator, 1
4...Photosensitive drum, 15...Original table.

Claims (1)

[Claims] 1. A pulse generator generates a pulse consisting of an on/off signal synchronized with the rotation of a drive motor for rotationally driving a photoreceptor of a copying machine, inputs the pulse to a microcomputer, In a pulse counting method for sequence control in a copying machine, in which a microcomputer counts the pulses by a predetermined number for each copying process such as charging, exposure, etc., and moves to the next copying process when the counting ends. , a first step of detecting a rising edge of the pulse from an OFF state to an ON state; and, when the rising edge of the pulse is not detected in the first step, controlling a copying sequence with the microcomputer; A first timer is set to measure the time during which the rising edge of the pulse is allowed to continue, and the first step is repeated a plurality of times, and the rising edge of the pulse is detected by the time-up of the first timer. a second step in which it is determined that the apparatus is abnormal and stops the copying sequence when the pulse is not detected; and a second step in which the microcomputer starts the copying sequence when the rising edge of the pulse is detected in the first step. A second timer is set to measure the shortest on-state time of the pulse allowed for control, and if the pulse is off when the second timer times up, it is determined that the device is abnormal. a third step of determining and stopping the copying sequence; and controlling the copying sequence with the microcomputer when the pulse is on when the second timer times up in the third step. A third timer is set to measure the longest allowed on-state time of the pulse, and detection of the on/off state of the pulse is repeated multiple times, and the pulse is in the off-state until the time of the third timer expires. and a fourth step in which it is determined that the apparatus is abnormal and the copying sequence is stopped when the copying sequence is not detected. 1. A pulse counting method for sequence control of a copying machine, characterized in that one pulse is counted when the pulse is turned off.