JPH0454237B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in document scanning devices such as copying machines.

When the scanning means for scanning the document is moved forward and then moved back and stopped at the home position, the drive is stopped before the home position in order to alleviate the shock caused by braking at the home position. A method was used in which the scanning means was moved using inertial force.

However, if the frictional force between the scanning means and the rail that guides the scanning means increases over many years of use, and the sliding is not performed properly, there is a problem that the scanning means stops before reaching the home position. It was hot.

The present invention solves the above problems, and includes a scanning means for scanning a document, a driving means for reciprocating the scanning means starting from a home position position, and a detecting means for detecting the scanning means at the home position position. a first detection means; and a second detection means, which is provided upstream of the first detection means in the backward movement direction of the scanning means and detects the scanning means, during the backward movement of the scanning means. The document scanning device detects the scanning means by the second detection means and stops driving the driving means, further comprising a timer for measuring time from the detection of the scanning means by the second detection means; If the measurement result exceeds a preset first predetermined time, the driving means is operated again to drive the scanning means in the backward movement direction.

FIG. 1 is a sectional view of an example of a copying machine to which the present invention can be applied, and its structure and operation will be explained.

The surface of the drum 1 is made of a three-layer seamless photoconductor using a CdS photoconductor, is rotatably supported on a shaft, and is rotated in the direction of the arrow by a main motor 21 activated when the copy key is turned on. Start.

When the drum 1 completes a predetermined rotation and potential control processing (preprocessing) described later, the original placed on the original platen glass 36 is illuminated by the illumination lamp 23 integrated with the first scanning mirror 24, The reflected light is reflected by the first scanning mirror 24 and the second scanning mirror 25.
is scanned. The first scanning mirror 24 and the second scanning mirror 25 operate at a speed ratio of 1:1/2, so that the original is scanned while the optical path length in front of the lens 30 is always kept constant.

The above reflected light image shows the lens 30 and the third mirror 2.
6. After passing through the fourth mirror 27, an image is formed on the drum 1 at the exposure section.

The drum 1 includes a pre-exposure lamp 8 and a pre-neutralizing charger 2.
The charge is simultaneously removed by the charger 3, and then the charge is corona charged (for example, +) by the primary charger 3. Thereafter, the drum 1 is subjected to slit exposure with the image irradiated by the illumination lamp 23 at the exposure section.

At the same time, a secondary charger 4 performs AC or corona charge removal with a polarity opposite to that of the primary one (for example -), and then a high-contrast electrostatic latent image is formed on the drum 1 by uniform surface exposure using a full-surface exposure lamp 9. do. The electrostatic latent image on the photosensitive drum 1 is then developed by a developing roller of a developing device 7 and visualized as a toner image, and the toner image is transferred by a transfer charger 5.

Upper cassette 13 or lower cassette 14
The transfer paper inside is sent into the machine by a paper feed roller 11 or 12, and is sent in the direction of the photosensitive drum 1 by a register roller 15 with accurate timing.
The leading edge of the latent image and the leading edge of the paper can be aligned at the transfer section.

Next, while the transfer paper passes between the transfer charger 5 and the drum 1, the toner image on the drum 1 is transferred onto the transfer paper.

After the transfer is completed, the transfer paper is separated from the drum 1 by a separation belt, guided to a fixing roller 19 by a conveyor belt 17 via a paper detection sensor 16, and fixed by pressure and heat, and then transferred to a discharge roller 42.
The paper is discharged to the tray 34 via the paper detection sensor 18.

Further, 29 is a conveyance fan for reliably conveying the transfer paper. Further, after the fixing is completed, the fixing roller is cleaned by the web 20.

After the transfer, the drum 1 continues to rotate, and a cleaning device 6 consisting of a cleaning roller and an elastic blade cleans the surface of the drum 1. The recovered toner is collected in a discharge toner container 43 through a pipe 45, and the process proceeds to the next cycle. .

FIG. 2 is a plan view of the operating section.

In the figure, 55 is a key for selecting the upper and lower cassettes, 54 is a slide lever for setting copy density, and position 5 is the standard density.
53 is a numerical key for setting the number of copies; 7
1 is a clear key for canceling the numerical value; 51 is an interrupt key for copying another number before the copying of the set number by key 53 is completed;
52 is a copy key for commanding the start of copying;
50 is a stop key for stopping the copy operation during continuous copying of the set number; 57, 58,
59 is a key for selecting the same size copy, enlarged copy, and reduced copy; 60 to 62 are indicators for displaying the selected reduction ratio; and 60 is a key for displaying the selected reduction copy mode. 61 displays the enlarged copy mode, and 62 displays the same size copy mode. There are five modes for enlargement: a mode for converting A size to B size; and a mode for reduction, based on combinations of reduction ratios of 1:0.67 and 1:0.79 and appropriate cassette selection. 72 displays the upper and lower stages of the cassette selected by the cassette selection key, and 56 displays the type of cassette loaded in the selected stage. Also, when the reduction key 59 is turned on, cassettes whose reduced size and sheet size match are displayed blinking when the selected cassette does not. At the same time, the size of the previously selected cassette is also statically displayed.

63 to 67 are warning indicators from the main body, all of which are displayed as pictograms. 63 is a paper feed check indicator that lights up when copy paper is jammed inside the machine. Reference numeral 64 lights up when there is no cassette in the cassette stand selected on the paper/cassette replenishment indicator, or when there is no paper left in the cassette set in that cassette stand. Reference numeral 65 denotes a discharged toner full indicator, which lights up when the container 43 is full of toner that has been used once and collected in the copying machine. Reference numeral 66 indicates a developer replenishment display, which lights up when the amount of developer in the developing device falls below a specified amount. Reference numeral 67 is a key counter confirmation indicator, which lights up when the key counter is not inserted into the socket of the main body.

70 is a weight indicator. This display lights when the power switch is turned on and the temperature of the fixing heater is lower than the specified value, and when the temperature exceeds the specified value,
The light turns off when the wait UP process is completed.

Reference numeral 68 denotes a copy number display, and when the desired number of copies is set using the numeric keypad 53, the set number of copies is displayed in seven segments. It is possible to set 1 to 99 sheets at a time. Approximately 60 seconds have elapsed since the end of copying, or by pressing the clear key 71 or the interrupt key 51, the set number of sheets and number of copies will automatically return to 01. 68 is an interrupt indicator that lights up when the interrupt key is pressed and goes out after the interrupt key is pressed.

FIG. 3-1 is a control circuit diagram of the copying machine shown in _FIG .
Q 72 is a microcomputer (hereinafter referred to as a management computer) that controls display operations and the start of copying operations, etc. _Q101 is a microcomputer (hereinafter referred to as a sequence computer) that controls the drive of the main motor, high voltage transformer, etc. for executing the copying process. ). Q ₁₀₂ is a ROM memory that stores the programs shown in the flowcharts of Figures 6-1 to 6-4 in the form of command word code routines, process timing data for sequence control, the number of copy sets and copy counts by key 53, and key 57. 59, size data from the cassette sensor, count number at the time of interrupt emergency copying, cassette stage save data, etc., RAM memory, I port, O port and I/O port that control input and output.
The ROM program is read by the O port and the clock O of the clock generator 700, and the ROM,
CPU that processes I/O and processes programs
This is a one-chip microcomputer that has the following functions in one chip semiconductor. Q ₁₀₁ is also a one-chip microcomputer similar to Q ₁₀₂ , and the ROM memory stores programs shown in the flowcharts of FIGS. 7-1 to 7-6. Q ₁₀₃ to _{Q 105} are the five input/output ports of each computer as shown in the diagram.
This is a port for expanding to books, etc. Reference numeral 800 corresponds to the circuit of each display of the operation unit and is connected to the Q ₄ and Q ₅ ports of the management computer, and 801 corresponds to the input circuit of each key and is connected to the i ₅ port. 802
is the above key matrix 801, display system 8
Probe signal (digit) to scan 00
This is a clock pulse generator for generating a clock pulse, and the input is connected to the program interrupt port of _Q102 . This pulse is frequency-divided and a repeated signal is output from port _Q4 . Reference numeral 803 indicates two switches that detect the position of the lens system and operate according to the movement of the lens.
When it is -1, a signal for equal magnification is output, when it is 30-2, it is enlarged, when it is 30-3, it is reduced, and when it is 0.79, and 30-4, a signal for 0.67 is output for _Q105 . 80
Reference numeral 4 designates four switches in each of the upper and lower rows that are activated by the cams of the cassettes when the cassettes are turned on to detect the sizes of the cassettes 13 and 14.The display is activated by turning on and off three of the four switches. Eight types of size data indicated by 56 are output. 806 is a switch 4 that operates when a sheet is manually inserted from above the lid of the upper cassette 13.
1, the roller 11 is shared for this sheet.
Execute copying. The sequence for this corresponds to the hand pointing case in FIG. 4-2. 807 is a switch for detecting the absence of toner in the developing device 7;
8 is a switch that detects the presence or absence of a key counter (total counter for each operator) and detects contact failure, and drives the display device by a circuit not shown. 80
Reference numeral 5 denotes a lens motor circuit for setting the previous lens system to a desired position in accordance with input for changing magnification, etc., and is controlled in accordance with the selection key 59 and position detection switch 803.

809 is a line for data exchange between the computers Q ₁₀₁ and Q ₁₀₂ , and arrows correspond to data requests and data directions. 810 is a clutch circuit for turning on the registration roller; 811 is a clutch circuit for inverting the mirror system to return after exposure; 812 is a developing device motor drive circuit; 814
815 is a high voltage transformer circuit such as a primary corona, and 815 is a switch installed at the mirror reversal position for the above reversal.
816 is a switch that generates a timing signal for register feeding; 817 is a home switch that is turned on when the mirror system is at the stop position; and 818 is a drum clock consisting of a photointerrupter that generates pulses by the rotation of a disk coaxial with the main motor. A pulse generator 819 is a main motor circuit for rotating the drum, to which the clutches described above and below are connected for power. Reference numeral 820 denotes a circuit for the lamp 10 which is controlled by the timing as shown in FIG. 4-2, and is turned on in a substantially opposite relationship to the exposure lamp 23. 821 is a clutch that moves the mirror system for exposure scanning; 822 is a circuit for the exposure lamp 23; 823 is a circuit that turns off the fixing heater when an abnormality is detected in the machine; 824 is a clutch that turns on the cassette roller 11 or 12;
25 is a circuit for increasing the key counter, and 826 is a circuit for detecting a jam in the sorter 46, which outputs a jam signal when a sheet presses the switch 47 provided at the entrance of the sorter in Fig. 1 for a longer time than specified. . 827 is a mechanical latch relay that is set when the main body or sorter is jammed, and the sequence computer _Q101 reads the status of this relay through the _i4 port of _Q104 . By releasing this relay, the copy blocking state is released, and the display of the number of jam losses on the display 68 is reset, and the number of losses is subtracted from the original number of copies and displayed.

This display 68 initially displays "01", displays the input number at key input, and when copying starts, displays the number subtracted by one from that number each time paper is fed. At the final scan reversal, the original input number is displayed again to facilitate re-copying the same number. After 60 seconds, it returns to “01” again.

During copying, abnormalities in the forward and reverse clutches (the mirror does not reach the specified position at the specified time even though control output is provided), abnormalities in the drum clock pulse generator 818 (pulse intervals are longer than specified), and fixing heater temperature. The control thermistor may cause problems such as disconnection.
When Q ₁₀₂ is detected, the number display 68 displays an error message "E1"..."E3" to identify the trouble. By repairing that part, the original number before switching is displayed.

Also, if a signal indicating that the sorter is ready is not obtained from the sorter 46, "EO" is similarly displayed. This display reset is also the same as above.

Also, when a jam occurs, the sequence computer
Sheet sensor 16 input to _i5 port of Q ₁₀₁ ,
18 sends jam data to Q ₁₀₂ via 809. Q ₁₀₂ determines the number of jam losses as 1 for the former and 2 for the latter, and displays them on the display 68 as "P1" and "P2". Similarly, “P0” is displayed during sortage jam.

In this example, reduction copying can be executed regardless of the cassette size, but it is not completely unrelated to the size detector 804, and is limited to only when reduction or equal size is selected.
Only when the size is not appropriate, the display 56 blinks to indicate the appropriate size. The sheet size that is being copied in parallel is also displayed. This has made it extremely safe to handle. The enlarged copy always scans B4 size strokes in consideration of the use of partial enlargement, so it is not displayed, but it is also possible to display whether or not it is appropriate.

In addition, in this example, in the case of enlarged copying, we would like to make the scan stroke correspond to the B4 size, which is one size before the maximum cassette size, rather than the A3 size, but if the enlargement ratio is higher, we would like to apply the scan stroke to the nth lower size from the maximum, such as A4 size. It can also be made to correspond to
Also, if the expansion is in multiple modes, the above nth, n+1
It is also possible to select a lower size such as the th. These can reduce wasteful scanning movements as much as possible and increase the speed of repeated copying of enlargements.

Next, the display circuit 800 will be explained using FIG. 3-2. This circuit is a circuit diagram corresponding to the operation section 501 shown in FIG.

This circuit is connected to the DC controller board equipped with the microcomputer Q102 shown in Figure 3-1, and the key scan probe signal
Digit1~6, key scan output signal KEY0~
3. Dynamic display digit signal JD-1,
2, 4, 5, and 6, and each terminal of the dynamic display segment signals SEG-a to SEG-g is connected to Q102.

Furthermore, regarding the relationship with FIG. 2, the light emitting diode LED801 for displaying two-digit seven-segment numbers is as follows.
Light emitting diode corresponding to copy number display 68
LED802~LED808 and LED818,81
9 correspond to the cassette size display 56 in FIG. 2 with the same names. light emitting diode led
809 to LED815 are scaled down in Fig. 2,
The same name corresponds to enlargement and same-size selection displays 60, 61, and 62. However, M in FIG. 3-2 represents enlargement, and 1:1 represents equal magnification. Further, the light emitting diodes LEDs 816 and 817 correspond to the upper and lower stages of the upper and lower stage selection display 72, respectively. These display elements LED801 to LED819 are JD-1 to JD-6.
As each digit signal up to this point, a +24V power supply is sequentially applied in a pulsed manner in the combinations shown in the figure, and as each segment signal from SEG-a to SEG-g, a 0V power supply is selectively applied in the same combinations shown in the figure. When applied, it lights up dynamically.

Operation time charts of Figures 4-1 to 4-2, Figures 6-1 to 6-4, and Figures 7-1 to 7
The control operation will be explained with reference to the control flowchart in Figure-6.

As a cycle executed prior to the above-mentioned copy cycle, there is a step of increasing the temperature of the fixing device while keeping the drum 1 and the fixing device 19 stopped after turning on the power switch SW1. (Figure 4-1,
Power switch on flow 70, 7 in Figure 7-1
1) This is to prevent the toner from solidifying in the fixing device until the temperature of the fixing device rises to a certain level, which could damage the fixing roller 19, and to raise the temperature more efficiently. It is.

Next, when the temperature of the fixing roller 19 exceeds the first set temperature, the main motor 21 is rotated at a low speed, and at the same time, the entire surface exposure lamp 9, the pre-exposure lamp 8,
The blank exposure lamp 10 is turned on to start irradiating the drum surface, and while the drum 1 rotates once, high voltage is applied to the secondary charger 4 and the light irradiation rotation continues until the second set temperature is reached. be. (Steps 72, 73). As a result, when the temperature of the fuser exceeds the first set temperature, the toner is melted and does not damage the fixing roller 19, so the temperature distribution of the fuser is made uniform, and the secondary charger 4 charges the drum 1. The residual charge on the drum 1 is removed, the optical memory of the drum 1 is reduced by light irradiation rotation, and the drum surface is cleaned by a cleaner 6. Figure 4-1, 4th
-2 In the figure, the dotted line in the main motor indicates low speed, and the solid line indicates high speed. It detects whether the rear door of the machine is opened or closed during a wait, turns off the wait lamp when it is opened, and waits for a copy start command to be input.

Further, until the temperature rises to the second set temperature, the lower fixing roller heater 32 is also turned on, contributing to the temperature rise.

Next, when the fixing roller reaches the second set temperature, the main motor 21 starts rotating at high speed and high voltage is applied to the pre-static eliminator 2, primary charger 3, secondary charger 4, and transfer charger 5. A value suitable for high-speed rotation is added and the drum makes one revolution. It is called forward rotation (74,
75). This is to apply high pressure to the entire surface of the drum 1 after various high pressures have been applied. When switching the drum speed, Q101 turns off the low speed signal to the main motor and outputs a high speed signal after 30 msec (73-2, 73-3). This prevents switching shocks.

At the same time, if the lens 30 is not at the same-magnification copying position (30-1), the lens 30 starts moving to the same-magnification position (76).

Next, when the drum 1 completes one revolution, the potential sensor 44 measures the drum surface potential (referred to as VSL) with the blank exposure lamp turned on, and then the drum surface potential (referred to as VSL) is measured with the blank exposure lamp 10 turned off. Measure the surface potential (referred to as VD). Based on the values of VSL and VD, the high voltage current flowing through the primary charger 3 and secondary charger 4 is controlled so that it approaches predetermined VD and VSL. Repeat this control several times (77).

Next, when the position of the lens 30 has reached the same magnification position (30-1 in Fig. 1), the original exposure lamp 23 is turned on, and the standard white plate 35 is illuminated with a reflectance corresponding to the white background of the original. , the potential on drum 1 (VL
) is measured by the potential sensor 44.
By measuring VL, the optimum image can be obtained at the "5" position of the density adjustment knob 54.
The lighting voltage of the original exposure lamp 23 is shifted.
This VL measurement control is repeated several times to optimally control the shift amount of the lighting voltage of the document exposure lamp 23. Finally, VL is measured and the developing bias of the developing device 7 is set to the optimum value.

As described above, by measuring VSL, VD, and VL (collectively referred to as potential control), the amount of charge on the high-voltage drum 1, the light amount of the exposure lamp 23, and the developing bias are controlled, and the optimal image is created. It is configured so that it can be done. Then, when the VL is measured and the control ends, the wait ends and copying becomes possible (78).

Further, as a cycle after the control rotation or after the copy rotation is completed, the drum 1 is rotated and the residual charge and memory on the drum are removed by the secondary charger 4,
There is a step of cleaning the drum surface (hereinafter referred to as post-rotation). This is about 1/5 rotation using only the secondary charger 4, and about 1/2 rotation with the voltage applied to the secondary charger 4 being weak. After the copy rotation is completed, the paper is rotated only by light irradiation until it is ejected.

The purpose of this post-rotation is to leave the drum 1 electrostatically and physically clean. After the post-rotation is completed, the drum stops and the fuser lower heater 3 is turned on again.
2 lights up, and the fixing roller is controlled by the thermistor 34 so that it is maintained at the third set temperature (steps 570 and 57 in Figure 7-5).
1).

After that, if it is left unused for 2 hours without doing anything, main SW2 will be automatically turned off by auto-shutoff.
be done (572).

Before auto-shutting, when each key is operated, the management computer sets each data.

The copy key is pressed and the data is transferred to sequence Q1.
If transferred to drum 1, depending on the time
The preprocessing before starting the copy operation described above changes depending on the stop time (leaving time) and variable magnification mode. (573, 574).

The differences in this preprocessing are listed below.

(1) Leaving time 60 seconds or less If the variable magnification mode is changed, the developing bias must be changed by measuring VL.

If there is no change in magnification mode, there is no potential control.

(2) Leaving time for 60 seconds or more Control the optimum value of image formation by measuring VSL, VD, and VL.

After the above preprocessing is completed, the copying operation shown in FIGS. 7-1 B and C begins.

That is, even if a variable size copy is to be made, if the start time is 60 seconds to 2 hours, the drum is operated at high speed in advance and then switched to low speed. Thereby, the above-described preparation process for the drum can be carried out sufficiently in a short period of time.

When the same size data and copy start command are sent from the management computer Q102, the sequence computer Q101 judges this (via 78 and 79 when in B mode, and via 77 when in C mode), and make it faster. When changing magnification (reducing or enlarging), the drum is delayed by 30ms to slow down (80). Next, as in step 81, the process is turned on and a lens movement permission signal is sent to the management controller Q102. Q102 receives this and sets the lens at a desired position according to the control operation shown in FIG. 6-4. In this way, since the lens is set only after copying is started, unnecessary lens operation due to zooming is avoided. Therefore, abnormal noise caused by lens movement can be reduced, and shocks can be prevented as much as possible. In this example, this is performed when an emergency copy is performed by interrupting copying, which will be described later, and also when returning to the original copy mode after the copy is completed.

Also, when changing the magnification, the drum is rotated one more time (83). This is for break-in operation when switching from high speed to low speed, and for potential stabilization and cleaning.

Management Q102 sets the position of the lens during the previous rotation. Only when the lens is moved, the potential is measured and a predetermined developing bias is set (171). Next, sequence Q101 to management Q102
requests variable magnification mode data, and if it determines that the data is an enlarged copy, sets in RAM data that will be inverted at the middle position among the three positions as mirror system scan inversion position data (172,
173). In other words, no matter what the cassette size is, medium
The B4 size position is the stroke length.

In the first reduction mode (1:0.79), (173),
The size data of the selected cassette is requested from the management Q102. And the cassette size is B5
It is determined whether this is the case (174), and if so, the short half-size position (A4) is set as reverse position data (175). If not, sequentially A4R,
It is determined whether they are A4, B5R, or n2, and if they are all different, the longest full size position (A3) is set as inverted data (176). In either case, the original middle position is set. Note that u2 is a small cassette that can store various small-sized sheets such as postcards.

When in the second reduction mode (1:67) (177), A4,
If it is not B5, u2, or B5R, the full size is used as the inverted data, and in any case, it is used as the middle position.

At the same size, only A3 is full size, A4, A5,
Half size for any u2, medium size for others.

In this way, an appropriate reversal position can be determined depending on the magnification mode and the cassette at that time. This can prevent unnecessary scanning operations.

The above combination is shown in FIG. A double mark indicates that the variable magnification mode and cassette size are appropriate. FIG. 9 shows the direction and position of setting the document on the platen glass. The sheets are arranged in the cassette in the same relationship as this direction.

Next, in Figure 7-3, the counter for the number of sheets remaining in the machine, the total counter, and the key counter are incremented by 1 (271), it is determined whether the manual feed switch is on, and the operation control of the upper cassette roller is performed. Do (272). The stage data of the selected cassette from the management Q102 is determined and one of the rollers 11 and 12 is turned on (273). Total, key counter +
1 turn off the solenoid. After a delay due to the count of the drum clock, a developing bias voltage is applied to the developing device, the blank lamp is turned off, and the document exposure lamp is turned on (274). The home position of the scanning optical system is confirmed (275), and a forward start signal for it is output (276).

At this time, one of the four advance clutches provided according to the variable magnification mode is selected, and the mirror and lamp are advanced at a scanning speed determined by the peripheral speed of the drum and the variable magnification ratio. 270mm/sec for actual magnification, 240mm/sec for 1:0.79 reduction, 284mm/sec for 1:0.67
seconds, 148mm/second when expanded. Outputs a signal to turn on the registration roller 15 during advancement (7-4
371) in the figure, it is determined whether or not the previously set inversion position has been reached by comparing it with the switch signal 815 in FIG. 3-1 (372). Then, turn on the blank lamp, turn off the forward motion of the mirror system, and turn on the reverse clutch (373). Then, the lamp is turned off or the exposure lamp is turned off with a delay only during reduction copying.
The optical system reaches the home position and stops (470).

Then, each process is turned off and the aforementioned post-rotation routine is entered (570). Next, it is confirmed that the transfer paper is discharged from the switch 18, and the drum is stopped (570). Thereafter, the above-mentioned routine processing is performed depending on whether the input timing of command data for restarting copying is within 60 seconds or other than that. If left unattended for more than 2 hours, the power of the microcomputer remains and everything else turns off.

Figure 7-6 is inserted into the closed loop of Figures 7-1 to 7-5, and the computer Q1
Data exchange between 01 and Q102, sensor 18
Detects sheet ejection from the machine and sets the in-machine counter to -1
control (I/O) to input and determine the thermistor disconnection signal and send abnormal data to the management Q102;
Further, a timer is used to determine troubles in the forward and reverse clutches, and a timer is used to determine troubles in the drum clock pulse generator, and data transmission is similarly controlled. If a problem occurs, the process returns to the power switch determination routine shown in Figure 7-1 and waits.

The management Q102 receives this data and displays identification such as EI, E2, etc. on the numerical display 68.

The main motor M1 is a motor that mainly drives the rotation of the photosensitive drum, fixing roller, etc. In this embodiment, the rotation direction of the motor is controlled so that the rotation speed of the drum is controlled in two stages. In the power transmission block diagram shown in Figure 5-1, one-way clutches CL1 and CL2 are provided on the output shaft of motor M1, and CL
2 is provided with a reduction gear. When the motor rotates clockwise (normal rotation), the power is directly outputted as clockwise rotational power via the one-way clutch CL1, that is, as shaft rotation along the normal rotation power transmission route LT1. Next, when the output shaft of motor M1 is rotated counterclockwise (reversely), at this time CL1
does not transmit power, and conversely, CL2 transmits power while the power is reversed, and is decelerated to a predetermined rotation speed by gear G1, and the output from G1 is again clockwise rotation, that is, the power at the time of reverse rotation. Along the transmission route LT2, the rotation is decelerated and output on the same axis as the above-mentioned axis.

In this way, in this embodiment, the rotational speed is changed by switching the rotation of the motor M1 between forward and reverse directions. Thereby, the rotational speed (copying process speed) of the photosensitive drum can be changed at low cost and by simple control, and stable rotation can be obtained.

FIG. 5-2 shows another embodiment of speed switching. The motor 1-1 is a motor that has two outputs in the same rotational direction but different only in rotational speed, and the transmission of each motor is switched using electromagnetic clutches CL3 and CL4.There are several ways to simply switch the rotational speed, but these are If the method described above is limited to two-speed switching, it is the cheapest and has the highest reliability.

In FIG. 3-3, in order to control speed switching mainly aimed at copying process speed, the common terminal J11-1 of the main motor M1 is connected to one power source, and the main coil terminal J11-2 and the auxiliary coil terminal J11- 3, and connect the terminals J11-2 and J11-3 to the other power supply via solid state relays Q304 and Q305, and turn on Q304 to turn on the M
1 is rotated in the forward direction, and Q305 is turned on to control M1 to be rotated in the reverse direction.

According to the switching timing of this drum speed, high voltage transformers for primary and secondary charging, transfer,
If the pre-static elimination transformer is on, its output is switched at a ratio of 1:0.7. The drum speed also has a 1:0.7 relationship. Experiments have shown that an output ratio approximately corresponding to the drum speed ratio is sufficient. Since the output of the processing means is weakened at low speeds, processing can be performed with an appropriate potential and a stable image can be obtained regardless of the variable magnification mode. The amount of light from the exposure lamp 23 is also changed in accordance with the movement of the lens due to the variable magnification set so as to always provide the same amount of image irradiation. In other words, it indirectly depends on the circumferential speed of the drum.

Incidentally, the voltage applied to the lamp can also be controlled in accordance with the drum circumferential speed switching control.

Further, in this example, the drum rotates at a low speed until the variable size (reduction/enlargement) copying is completed and the drum stops. Thereafter, during rotation, the same size key is input, and the management Q102 receives it and displays it, and even if the copy key is used to start, the drum does not speed up. After that, the main motor's reverse rotation output is turned off only after rotation is complete, and the output is switched to forward rotation after 30 milliseconds. Therefore, unevenness due to speed switching does not occur in equalizing the drum potential during post-rotation.

Further, the rotational speed switching system of this example can correct rotational changes due to differences in power supply frequency by detecting the change or automatically or manually switching the motor between forward and reverse directions depending on the frequency.

The operation of the management controller Q102 will be explained with reference to FIGS. 6-1 to 6-4. In Figure 6-1, when the computer power is applied, the I/O ports and RAM are cleared to the initial state (step 6).
0) Confirm that the reset of the sequence controller Q101 has been completed (61), and start operation. Then, an oscillator signal (1.2KHz) is applied to the interrupt terminal (iNT) to enable program interrupt processing (62), and this signal generates an interrupt.
Execute the routine in Figure 6-2 to scan each key and dynamically display each display 162.
It monitors data serial transfer requests exchanged between Q101 and Q101.

Incidentally, since the probe signal for this dynamic display is used to detect an abnormality in the management controller Q102, it is scanned and outputted regardless of whether the main switch is turned on or not, in preparation for display. However, when the main SW is not turned on, the power for display is turned off by the sequence controller Q101, so it does not actually light up.

By the way, when the main SW input signal is transmitted from the sequence controller Q101 by serial transfer, the management controller Q102
Allow key input, clear the 2-hour timer, and restart it (63-65).

During wait, sequence controller Q10
In order to control the current of the charger and the document exposure lamp by single potential control, the lens position must be at the same magnification position. Therefore, the management controller Q102 is the sequence controller Q10.
Since a signal requesting the "lens equal magnification position" is sent from 1, the lens is made equal to the same magnification by the lens movement subroutine shown in FIG. 6-4 (67).

When the wait end signal is transmitted from the sequence controller by serial transfer, the 60 second timer is cleared and restarted (68).

By the way, the 2-hour timer and the 60-second timer are timers that are extended each time the operator operates the copying machine, such as by pressing a key. The 2-hour timer turns off the power switch to save energy when the operator forgets to turn off the copier when the copier is not operated for more than 2 hours.
Make it. Further, the 60 second timer is used to initialize the display when the operator does not operate the copying machine for 60 seconds or more. This 60 second timer selects the standard mode, that is, the same size selection and the lower cassette, and sets the set number of copies (display 68) to "1" (69). However, if there is not enough developer or if there is no paper or cassette, the 60 second timer will not work. This is done in consideration of the fact that the operator is recovering from a copy interruption state. Also, the 60 second timer does not operate during the wait.

The MCOM-Q101 and Q102 shown in FIG. 3-1 will be explained in detail.

(Serial Transfer) Data exchange between microcomputers in this example is performed by data serial transfer. In this example, data is not transferred to either one of the two MCOMs, but simultaneously in both directions. The process will be explained in detail below using the flowcharts shown in FIGS. 6-2 and 7-6.

First, the sequence controller MCOM-1
01 port Q ₁₁ of the management controller
Send serial transfer request signal RQ to input port i ₁₁ of MCOMQ 102 (step 60 in Figure 7-6).
0). This is done by setting the serial request line 112 from Q101 to the "L" level. When Q102 senses “L” on this line 112 (step 164 in Figure 6-2), Q1
It prepares serial data from 02 to Q101 (165), and sends a signal (ENABLE) indicating that serial transfer is possible via line 111 to Q101 (166). When Q101 receives this enable signal (602), it prepares for serial transfer data from Q101 (603), and then Q101 and Q102 simultaneously transfer data to each other through lines 114 and 115, respectively, in the form of data exchange. (Step 167 in Figure 6-2, Step 604 in Figure 7-6). In this step, it is determined whether the shift register has received 16 bits of data and the data is transferred.
Store in RAM and judge the contents. Note that the transfer is performed by shifting and storing data in each shift register in sequence using a shift clock pulse on line 113. As shown in FIG. 10, this data is set depending on which of the 16 bits is 1 or 0.
Pipe → shi means from Q102 to Q101, shi →
The "tube" is the data content sent from Q101 to Q102. For example, the data received by Q101 at address 1 of ST3 indicates that a trouble has occurred in the lens movement when the time variable magnification is set to 1. Sequence Q101 thereby prohibits the copy operation. When address 2 of ST1 is 1, it indicates input of an enlarged copy set. Q101 thereby performs enlargement control such as changing the speed of the main motor and optical system. Also, if Q102 is received and address 2 of ST0 is 1, it indicates that a trouble has occurred in the movement of the optical system, etc. Management Q1
02 thereby displays an error (such as EO) on the copy display 800 using the LED segment and controls the prohibition of key input. Also, SO0's address 1, 0 is 1
This indicates that the back door switch or main switch is open, and Q102 changes the weight display or stops the number display control, etc. accordingly.
Similarly, data written in the drawings corresponds to each bit.

The same holds true when a transfer request is issued from the port of the management Q 102 to the sequence.

Q101 is configured to perform periodic serial transfer at approximately 370 msec. This is done by the transfer timer t (an internal timer as described above) (600, 606).

Also, monitoring of the serial request from Q102 in Q101 is performed by port sensing, and is performed by a subroutine provided in the closed loop routine in the main flow of the sequence. This subroutine also constantly monitors the on/off status of the main switch (step 59 in Figure 7-6).
9).

Also, the monitoring of the serial request from Q101 in Q102 is performed in addition to the key input control and dynamic control routines for displaying the number of copies and the like. Therefore, it is monitored almost all the time.

By the way, the management controller Q102 has a timer t' that is initialized every time serial transfer is performed. Sequence controller Q
It is possible to recognize a case where serial transfer is stopped due to runaway of 101 or the like. That is, the steps in Figure 6-2
The internal timer is started by 169, and if the next transfer is not made within the timer time (170), the sequence controller recognizes that there is an abnormality and enters the closed loop program 172, stopping the key scan and segment scan probe signals. Put it away. This activates the abnormality detection circuit 900 connected to Q102. (Described later) The management controller abnormality detection circuit 900 is
Shown in Figure 2. This is for dynamic display of periodic signals output from the management controller Q102.
While monitoring the Digit signal, if the Digit signal does not change for a certain period of time, the microcontroller Q101,
Activate the reset circuit for Q102. Therefore, when the management controller Q102 is abnormal, the sequence controller Q101 uses a reset circuit to cause the two microcomputers to run from the initial state of the flow.

(Computer reset control) When performing sequence control of a copying machine using multiple microcontrollers, the time it takes for the microcontrollers to reset and start running when the power is turned on may vary depending on the chip, and there is a possibility of copying errors. be. In this example, when the reset of one microcomputer is completed (or after a certain period of time has passed after the completion of the reset), it is checked whether the other microcomputer has been reset. This can prevent the microcomputer from running and the copying operation becoming uncertain.

In this way, the microcomputers start each other's operations after each other's microcomputers have finished resetting and become operational.

Also, if one MCOM is in an abnormal state, the program will not run from that state, so both programs will not proceed. Therefore, the copier load does not operate unnecessarily.

6-1, 7-1 flow diagram, 11th, 12th
This will be explained using the circuit diagram shown in the figure.

When the line is connected to an AC outlet
The +5V power that operates the control center parts such as MCOM is turned on. Then, the reset circuit shown in FIG. 12 operates and MCOM-Q101 and Q102 are reset. Timer period being reset
All output ports of MCOM-Q101 and Q102 become "H" level. Next, when the reset signal disappears, MCOM-Q101 and Q102 will reset to ROM.
The program starts from address 0 in .
MCOM-Q101 and Q102 are each RAM
is cleared and the output port is set to the initial state (60 in Figure 6-1, 68 in Figure 7-1).
Next, in order to eliminate mistakes in initial state exchange between MCOM-Q101 and Q102, each
An amount of time is consumed by an internal timer by counting the microcomputer's clock. Next Q
102 is a serial transfer request to Q101
The RQ signal is output using the output port 110. This output port is at the "H" level at the time of reset and in the initial state of the output port, and is configured to be at the "Low" level when issuing a request.
MCOM-Q101 detects that a serial request has been issued from Q102 and starts serial transfer. When the serial transfer is finished, the MCOM
- Q101 and Q102 check whether the serially transferred data is the data at the end of a predetermined reset (61 and 7 in Figure 6-1).
69 in Figure 1), if there is an error in the transfer, retry the serial transfer. Then, when the serial transfer data matches the predetermined data (address 3 of ST3 in Figure 10), MCOM-Q101,Q
102 enters the next operation.

(Power on/off control) Q101 monitors the main switch signal (70), and when the main switch is turned on, Q102
Data is transferred by serial transfer to indicate that the main SW is turned on. Then, the 24V power supply used for loads such as the resist clutch and the 5V for display are turned on (70-1). While the main switch is not turned on, Q101 waits while clearing the RAM and I/O. This prevents malfunctions as much as possible.

In FIG. 10, the power-on signal is Q101.
The 24V power regulator VR1 and the 5V regulator VR2 output from port θ8 are turned on in the usual manner. Therefore, display regulator VR2,
Even if the microcomputer regulator VR3 is connected to the transformer T2 rectifier D2 without going through a common main switch, the display can be reliably inactivated.

Furthermore, when resetting the microcomputer, conventionally, a driving element such as a hammer driver connected to the output of the microcomputer is turned on, and a voltage is applied to the load, causing the load to be turned on.

But after the microcomputer determines the output port status of all loads, the load power supply 24V
etc., so there is no inconvenience during a power-on reset. In addition, when a plurality of microcomputers are used, the risk can be prevented to the maximum extent because the program is run with the reset confirmation operation as described above.

Note that the reset confirmation may be performed for only one microcomputer (for managing the sequence).

(Computer Reset Circuit) Next, the microcomputer reset circuit shown in FIG. 12 will be explained. Q108 is a comparator with two circuits, and its functions are divided into Q108-1 and Q108-2. First, power supply for microcomputer +5V (Vcc)
is started by turning on the power outlet or turning on the serviceman switch SW1 shown in Fig. 3-3, the comparators Q108-1 and Q10
A voltage divided by approximately 1/2 of Vcc by resistors RA133-2 and RA131-4 is applied as a threshold voltage to each side input terminal (No. 2) and side input terminal (No. 5) of 8-2. At this time, resistance RA133-
1 and a time constant circuit using a capacitor C110.
A delayed rise of Vcc is applied to the side input terminal (No. 3) of Q108-1 via resistor RA133-3. At this time, for about 30 msec after the power is turned on, the voltage at the side terminal is higher than the voltage at the side terminal.
0V is output from the output terminal (No. 1) of 108-1, and this becomes a reset signal for the microcomputer when the power is turned on. The diode D119 is a discharge diode when the power is turned off, and the resistor RA134-2 connected to the terminals 3 and 1 of Q108-1 is provided to provide hysteresis to prevent malfunction and chattering. Also, at this time, the output terminal (No. 7) of Q108-2 is in the OFF state.

Next, to explain the microcomputer stop detection circuit, when MCOM-Q101 and Q102 are operating normally, a digital signal for dynamic display on the operation panel is output from microcomputer Q102, and part of that signal is a repetitive pulse signal. It is applied to the trigger terminal (No. 8) of the timer ICQ135 via the buffer driver Q112 and further via the differential capacitor C106. At this time, a bias voltage of about 2.5V is applied to the No. 8 terminal by resistors RA131-2 and RA131-3, and the positive side clamp diode D121 is also connected as shown.

Time setting terminals 13 and 12 of this timer IC
The terminal No. 5 is connected by resistors RA131-1, RA134-1 and a capacitor C107 as shown in the figure to provide a time-up time constant longer than the interval of the minus trigger pulse input to the No. 5 terminal. When a trigger pulse is periodically input to this terminal No. 8, approximately 5V will be generated from output terminal No. 9.
Since the voltage is outputted and connected to the input terminal (No. 1) of the hammer driver Q119, the output terminal (No. 16) of the Q119 is in the ON (0V) state at this time.

On the other hand, the side terminal (No. 6) of the comparator Q108-2 is connected to a time constant circuit composed of resistors R134-4 and C115, and
9 output terminals are connected via R116. Naturally, when the power is turned on, no display digit signal is generated until the microcontroller completes resetting.Q
0V is output from the output terminal of Q135, and Q119
The output of Q108-2 is in the OFF state, and the voltage at the 6th terminal of Q108-2 gradually rises, but the voltage at the 6th terminal becomes higher than that at the 5th terminal after the power is turned on.
It is set as 330msec, and during this time, as mentioned above, Q
Output terminal No. 7 of 108-2 is in an OFF state. However, by the time 330 msec has elapsed since the power was turned on, the microcomputer has completed its reset and started operating, so a display digit signal is generated and the output terminal 16 of Q119 is turned on and becomes approximately 0V. The 6th terminal of Q108-2 has Vcc as R134-
By setting this divided voltage lower than the No. 5 terminal of Q108-2, the output No. 7 terminal of Q108-2 will eventually become
If it remains OFF, it will be in a steady state. If an abnormality occurs in the microcomputer and the display digit signal is no longer output, the 16th output terminal of Q116 turns OFF, and the voltage at the 6th terminal of Q108-2 increases, and after about 200 msec, the 7th output of Q108-2 The terminal turns ON (approximately 0V), and by instantly discharging the charge of C100, the voltage at the input terminal 3 of Q108-1 is lowered, and the output terminal 1 turns ON (approximately 0V), generating a reset signal for the microcomputer. .

At this time, this reset signal is applied as a "0" level to the trigger terminal (No. 8) of the timer ICQ135 via D120 as shown in the figure, and the output No. 9 terminal becomes 5V, and the output No. 7 terminal of Q108-2 becomes 5V. becomes OFF state with a slight delay due to the discharge time constant of C115 and R116, and then about
After 30msec, the microcomputer reset is canceled again.
At this time, as long as the microcomputer is not destroyed, the microcomputer can return to normal operation, so this function is useful as an automatic repair function when the microcomputer itself malfunctions due to extreme external noise.

(Sequence timing) In Figure 7-1, the above-mentioned MCOM-Q ₁₀₁
By resetting Q ₁₀₂ and starting the program after determining the main switch, the fixing heater and main motor are operated in sequence, and then the surface potential is measured and its optimal control is performed. After waiting for the weight to rise (78 ) The copy start input from _Q102 is determined (79), and the memory set for the optical system inversion position shown in FIG. 7-2 is performed. This is set by the desired magnification input (59 in FIG. 2) and the cassette size input (172-177), as described above. In addition to specifying the cassette using the key 59 in FIG. 2 as input for changing the magnification, it is also possible to input only the changing magnification using the keys.

After this, the sequence computer Q ₁₀₁ is the 7th-3rd
Start paper feed control as shown in the figure. A timer (internal timer) to check for abnormal operation of the optical system before
Clear and start.

In Figure 7-3, when a jam occurs, the counter for the number of sheets remaining in the machine for counter correction is incremented by 1, and the total counter and key counter 3 are added.
7, 38 are turned on (271), and if the manual feed mode is not set, the pick up roller 11 or 12 of the upper or lower selected cassette is turned on (273). As a result, the total counter operates simultaneously with paper feeding.
By the way, since the paper feeding paths are different for the upper and lower stages, the paper is fed by two rotations of the roller for upper stage paper feeding and one revolution for lower stage paper feeding. Steps 273-2 and 273-3 relate to clutch control for upper paper feeding only.

The pick-up roller is constructed so that when the clutch is turned on, it mechanically rotates half a turn and stops, and when the clutch is turned off, it mechanically rotates one more time and stops at the original position.

Therefore, in the case of upper paper feeding, the clutch is turned on and turned off before the roller has made half a revolution. Then, by turning on the clutch again after half a revolution or more and less than one revolution (273-8), it is stopped and held at one and a half revolutions. However, in the case of lower paper feeding, the clutch 12 is stopped and held in a half-rotated state by turning on the clutch once.

By the way, after paper feeding starts, the total counter and key counter 3 are counted at the off timing of the upper clutch.
7, 38 is turned off to complete the operation (273-4).

Then, the forward clutch 22 is turned on (276). However, since the halogen lamp for exposing the original does not rise to a sufficient amount of light until the optical system enters the image area, it is turned on in advance before the forward clutch 22 is turned on (274). At the same time, the blank exposure lamp 10 for black erasure is turned off according to the paper size. Then, the developing sleeve 7 for development is rotated, and a developing bias appropriate for developing is applied to the developing sleeve (274-0). Then, the forward clutch corresponding to the magnification change is turned on, and the optical system begins to move forward at a speed corresponding to the magnification change. Since it is the first card, it starts forward with a delay of 53 clocks (276-0).

FIG. 13 is a schematic cross-sectional view of the optical system scanning section and lens section of FIG. 1, and FIG. 14 is a perspective view of the scanning section. With reference to these, in this example, new scanning system control,
Registration control, blank control, pick-up control, etc. will be explained.

(Regist) In FIG. 14, reference numerals 306 and 307 are a registration control flag member (hereinafter referred to as a comb flag) and a scanning system control flag member that move in synchronization with the movement of the first mirror 24. It is fixed to the rail fixture as shown in the figure. 306 is provided with five light shielding parts 1 to 5 in a comb shape, and 307 is provided with two light shielding parts. Further, 304 is a photo interrupter which blocks light and generates a signal when the comb portions 1 to 5 of the flag 306 pass therethrough, and 302, 303, and 305 are photointerrupters which generate a signal when the light blocking portions 1 and 2 of the flag 307 pass therethrough. This is a photo interrupter that generates a signal when light is blocked. 302, 303 are electrically shot
The input is connected to the input port i ₃ (Figure 3-1) of Q ₁₀₁ in an OR relationship. 305 is input connected to i ₆ and 304 is connected to i ₇ .

Photo interrupter (hereinafter referred to as sensor) 30
2, 303 is mainly for stopping forward movement and starting backward movement. 305 stops the optical system,
A sensor 304 is used to control the registration timing.

First, the optical system starts moving forward according to the procedure described above, and when the first digit of the flag 306 passes the sensor 304, the optical system is at the exposure start position of the original image (276-1). At this time, stop the registration roller 15 and prepare to align the leading edge of the paper (276-
2). Then, after the sensor detects the drum pulse, the drum pulse is set 18 clocks after the sensor detects it, so that the paper that hits the stopped registration roller draws a loop of the appropriate length. Release the clutch, rotate the roller the remaining half turn, and stop (276-3). Thereafter, the paper hits the registration rollers 15 and stops.

In the case of the same magnification, the sensor 304 is connected to the flag 306.
When the third one is detected (370-3), the registration roller 11 starts rotating (371). Also, in case of reduction -1, set the 4th to (370-1), in case of reduction -2, set the 5th to (370-2), and in case of enlargement,
By detecting the second one (370), the registration roller 15 begins to rotate. This is because the paper conveyance speed and the scanning speed of the optical system differ depending on the magnification change, but even in response to these differences, the timing position at which the registration roller 15 starts rotating is changed so that the leading edge of the paper and the leading edge of the image on the drum match. This is what I did.

By the way, the procedure for confirming flag positions 2 to 5 is performed by counting pulses generated from the sensor 304 while the vehicle is moving forward. It determines the position by counting from the tip signal of the original flag 306. By providing a program for this count as an interrupt program to be executed with priority in the memory ROM and connecting the output of the sensor 304 to the interrupt port of the MCOM-Q ₁₀₁ , it is possible to avoid creating multiple step routine programs for counting. I'll try it.

(Reversal) Next, when the forward exposure of the optical system is completed, the flag 307
1 and 2 reach sensors 302 and 303. By the way, the optical system is A4 size, B4 size, A3 size,
Advances at three different reversal positions depending on each paper,
Reverse movement is controlled. On the other hand, sensors 303 and 302
The output of is wired OR and the flag 307 is the sensor 3
When passing 02 or 303, a pulse is output.

The distance between the first and second flags 307 is (A3 size - B4 size) = 44 mm, and the sensor 303 is at the A4 size inversion position on the optical system movement path, and the sensor 302 is at the B4 size inversion position. provided at the location.

And the A4 size inversion position is sensor 303
When the second flag of flag 307 passes, B4
The size is reversed when the first of the flags 307 passes through the sensor 302, and the A3 size is reversed when the second of the flags 307 passes through the sensor 302. In other words, the second signal of the wired-OR signal by the reversal sensors 302 and 303 controls the reversal of A4 size, the third signal can be detected as the reversal position of B4 size, and the fourth signal can be detected as the reversal position of A3 size. . The above is shown in step 372.

These second, third, and fourth determinations are made by the sensor 302,
This is done by counting the pulses of the OR signal from 303 as 2, 3, and 4 depending on the input signals from the cassettes A4, B4, and A3 (however, the cassette on the designated side).

I will explain why I installed two reversal sensors and wired or. If the number of reversal sensors is 1 and the small flags 307 are provided at three locations, the reversal positions can be determined at three locations. However, the distance between the small flags reaches a maximum of (A3-A4) = 210mm, and in the case of an A3 size scan, the range of movement and influence of the largest flag is (A3 + 210) = 430mm. The protrusion of the flag member in the scanning direction of the machine becomes large.

In this example, two sensors and two small flags are used to detect three positions, so the protrusion of the flag member is only 44 mm, contributing to miniaturization of the copying machine. Also, a large number of inversion controls can be performed with a small number of sensors. Furthermore, the sensor,
By increasing the number of small flags, even more reversal control can be performed. It is also possible to check whether the optical system has overrun beyond the specified limits. The above and the following can be applied not only to the moving optical system scanning type but also to the type in which the optical system is fixed and the document table moves back and forth.

(Blank lamp, exposure lamp) As described above, reversal control is performed regardless of magnification, but since the speeds are different, in the case of half-size copying due to reduction, the time required to complete copying can be shortened. You can substantially increase the speed of repeated copies.

After detecting the reversal position and before controlling it, the time operation of the optical system abnormality timer t mentioned above is canceled (372-1). Also, turn on the blank lamp in advance (372-2). This was done in consideration of the rise of the blank lamp, and at the same magnification, after turning on the blank lamp and counting three drum pulses, the forward clutch 22a is turned off and the reversing clutch 22b for reverse movement is turned on (373).

When reducing, after the desired reversal sensor is detected, the forward clutch 22a is turned off and the reversal clutch is turned on after counting 8 clocks and turning on the reversing clutch (372-3).Then, the document lamp 23 is counted for 5 more clocks and 13 clocks in total. Turn off (372-1). In other words, the exposure lamp 23 is turned on slightly even at the beginning of reverse movement.

This is to prevent parts outside the original image from appearing on the transfer paper during reduction, and to prevent black areas from appearing on the transfer paper by overlapping the blank exposure and the original exposure. If blackening is performed using only blank lamps, the blank lamps are often used in rows of small lamps, and in this case, the arrangement of the lamps will be uneven. Therefore, to prevent this, the exposure lamp is also kept on. It is also possible to reduce the light intensity of the exposure lamp to about 2/3 at the time of reversal or at the end of exposure before that, and to continue turning it off until the above-mentioned lamp off timing, thereby reducing lamp burnout due to reversal shock.

(Repeat paper feeding, home stop) By the way, when the second flag of the flag 307 passes the sensor 303 during reversal, preparations are made for feeding the next copy (373-3). Although the flowchart states that this is executed 13 clocks after inversion, it is executed at the same time as the inversion starts. In order to determine the paper feeding timing by the combination of the flag 307 and the sensor 303 regardless of the size, pulses of the OR signal are counted as described above as shown in the flowchart. In this way, even if the size is different, the loop amount is kept constant so that it can wait in front of the registration roller. Then, the copy start data (ST2-2 in FIG. 10) in the serial transfer from the management controller Q ₁₀₂ is checked to see if copying is to be continued (374). This data is output and set by the copy counter function of the management controller, and when the copy counter counts up to the preset number, it becomes 0, indicating that copying will not continue. This counter checks the serial data (1 in ST2) from the sequence controller Q ₁₀₁ to the management controller Q ₁₀₂ and increments it by 1, and this data is set to 1 when the aforementioned inversion is detected.

After counting up, the process shown in Figure 7-5 is executed, and when the optical system reaches the home position, the sensor 305 detects flag 3.
07-2 is sensed, the reverse clutch 22b is turned off, and the optical system is stopped (470).
In the case of magnification (468), when the magnification is the same, the first flag of the flags 306 detects the sensor 304, and the reversing clutch 2b is turned off in advance, after which the optical system is run by inertia to the home position. This detection is performed by counting five pulses from the sensor 304 during reversal (469).

This is because the process speed is changed when magnifying the image at the same magnification and when changing the magnification, so the speed of the optical system when reversing the image changes. Therefore, when changing the magnification, even if the reversing clutch 22b is disengaged after detecting the home position, there is little impact.However, when the magnification is the same, the reversing speed is fast, so if the reversing clutch 22b is disengaged after detecting the home position, it will not be possible to disengage the reversing clutch 22b after detecting the home position. The impulse that hits the stop increases. This can be prevented.

By the way, after copy repeat is confirmed in step 374 of FIG. 7-4, the process returns to FIGS. 7-2 and 7-3 and the same control as the above-described pickup operation from the first sheet is performed. However, as shown from step 274-4 onward in FIG. 7-3, a different routine is performed for the second and subsequent copies. 274-4 to 275-1
The routine up to this point is the same as the optical system reverse clutch-off routine shown in FIG. 7-5, and off control is performed in accordance with the same magnification or variable magnification.

After detecting the home position (275), forward clutch 2 is activated again.
2a is turned on (276), and the registration roller and pick-up roller are turned off as described above.

By the way, since one cycle of the optical system is about 4 seconds, timer A, which is cleared and started at the time of paper feeding, does not elapse for more than 4 seconds. If the timer has elapsed for more than 5 seconds, it means that some kind of abnormality has occurred in the optical system, and the copying operation must be stopped immediately (fusing heater, corona high pressure, main motor, etc. are turned off except for the display), and there is an optical system abnormality. Display.
This is accomplished by step 598 of Figure 7-6.

In this case, this stop and display routine will be repeated unless the main switch is turned off.

However, when the optical system is reversed at the same magnification, if approximately 1 second (more than 4 seconds after paper feeding) has elapsed after the reversing clutch is turned off, the inertia may be increased due to worsening of the rail on which the mirror runs. It is assumed that the force has decreased, and in this case, the reverse clutch 22b
Turn it on again and reach home (275-3).
However, if the home position is not reached even after the abnormality detection timer A operates for a total of 5 seconds or more, copying is stopped and an abnormality is displayed as described above. Incidentally, the abnormality timer A is cleared by detecting the home position.

When changing the magnification, abnormality determination is simply executed in the subroutine shown in FIG. 7-6 as described above.

In this way, a safe and highly accurate copying machine can be provided.

By the way, in each closed loop in Fig. 7 (not shown)
When one sheet of paper is discharged according to the subroutine of FIG. 7-6, the in-machine sheet number counter is decremented by 1 in response to a signal from the exit sensor 18 (FIG. 1) (607). Therefore, even if the machine stops due to a jam or the above-mentioned abnormality in the optical system, the number of sheets remaining in the machine can be known. This number is subtracted from the copy number display and displayed when copying is interrupted. This shows the aforementioned copy stop power,
This is because the subtraction number can be stored in the RAM in the MCOM because it is executed without turning off the SV of the computer power. If you turn off the main switch when copying is interrupted (608), the
Since the RAM clear step is executed and the process waits, the number and display are canceled. Note that even if the main switch is turned off during this interruption, it is also possible to continue storing and displaying for a predetermined timer period, and then automatically turn it off after that timer period. This can be achieved by providing an internal timer operation corresponding to the above timer between and 608. This timer is also the time of the autoshaft timer 572 in Fig. 7-5.

After the repeat copy is completed and the optical system stops at the home position shown in Figure 7-5 as described above, the drum pulse is counted for 64 clocks and the developing bias and each high voltage transformer are turned off (step 570), and then
Count 90 clocks to weaken the high-pressure secondary corona, then count 169 to turn it off.
Then, it is checked whether the trailing edge of the paper has been discharged from the exit sensor (570-1), the main motor and blank lamp are turned off, and a standby timer is started. At this time, serial data is sent to the management Q ₁₀₂ to start the 2-hour timer. If you do not turn on the copy key after that, the sequence Q ₁₀₁ will turn on the main switch 501 according to the 2-hour up data from the management.
is forcibly turned off by the plunger. Sequence Q ₁₀₁ determines whether the main switch is off, turns off the outputs of regulators VR ₁ and VR ₂ , and turns off all loads including the display.

If you turn on the copy key before 2 hours have elapsed, it will be determined whether it is within 60 seconds after the main motor was turned off and the 7th
-1 Enter routine B or C in Figure 1 and resume copying.

Incidentally, data such as abnormalities in the optical system are sent to the management controller by serial transfer, and the management can judge the data and cause the number display 68 to display different errors.

Also, the drum clock pulse is drum 1 in Figure 13.
It consists of a disk 206 and a photo interrupter 205, which rotate in synchronization with the routine I.
As shown in 2, it is determined whether the clock interval is normal or not by sequence _Q101 , and the same processing as for an abnormality in the optical system is performed.

However, if a break in the thermistor, which measures the temperature of the fusing roller and controls the power supply to the fusing heater, is detected, Sequence Q ₁₀₁ increases safety by taking a different action than in the case of problems with the optical system or drum. That is, as shown in routine I.0, after performing the same off control as described above, the NOP step is repeated to electrically lock the machine so that it will not return to the initial routine even if the main switch is turned off. Therefore, the initial step will not be returned unless the power connector is disconnected, so it can be determined that the problem is extremely dangerous even without any indication.

Figure 13 is a schematic cross-sectional view of the optical system and lens system.
Figure 5 is a plan view of the lens control element, No. 16-
1 and 16-2 are control time charts. Microcomputer shown in Figure 6-4 below
The operation will be explained according to the flowchart of lens movement control in MCOM, Q102.

In FIG. 13, 203 and 204 are disks for detecting the position of the lens 30, and the lens position 30-1
It rotates in response to the movement of ~30-4. 204,
203 is coaxial. 201 and 202 are photo interrupters that detect holes and notches in disks 203 and 204, respectively, and generate signals, and the 201 signal is counted by MCOM and Q102. Each counter sensor is called a same-size sensor. 207 is a lock plate that prevents the movement of the lens, 208 is a plunger that releases the lock plate by pulling it in the direction of the arrow, and 209 is a clutch that moves the lens and rotates the discs 203 and 204, and provides power to the main motor that drives the drum. Connecting. The notches 30-1 to 30-4 of 203 in FIG. 15 correspond to the lens positions in FIG.
Corresponds to 0-1.

Lens movement is 30-1 (same magnification) → 30-4 (reduction 2) → 30-3 (reduction 1) → 30-2 (enlargement)
Perform in this order.

The same magnification position of the lens is determined by placing the disk 20 on the sensor 201.
15, in which the notch 30-1 of FIG.

The operation when the lens is not at the same magnification position and is moved to the same magnification will be explained.

It is executed in step 74 of the control flowchart in the management computer in Fig. 6-1 and is executed in step 6-4
In the figure, the lens lock release plunger 2 is shown first.
08 is turned on (74-1), and the lens 30 is made movable. Then, the timer TB, which measures the time required to lower the lens lock plate 207, is cleared, 200 msec (T ₁ ) is set, and the process starts (7
4-2). Before setting TB, set and start the aforementioned lens movement abnormality timer TA (2 sec).
When _T1 has elapsed, the lens moving clutch 209 is turned on (FIG. 16-1), and the lens 30 begins to move (74-3). Since we are specifying the same size, sense the same size flag and execute the following (74-4),
When the lens approaches the 1x position, the 1x position sensor 2
Since the convex part of the disk 204 comes to 02, the sensor 202
outputs “H”. The rise of this H is Q102
is detected (74-5) and the lens counter (RAM
Set "7" in the count area (provided in the counter) and turn off the lock plunger 208. Thereby, the lens lock plate 207 is raised to position the lens so that it does not exceed the same magnification position (74-6). When this locking operation is completed, the signal of the sensor 201 is judged (74-7). When this locking operation is completed, the sensor 201 changes from the light-shielded state by the disc 203 to the light-shielded state. In other words, the lens is exactly at the same magnification position at the time of change. Note that the sensors 201 and 202 are the third
Since the input wiring is as shown in Figure -1, 74-5, 7
Step 4-7 is performed by checking the level change of the input port.

However, if the lens movement clutch 209 is turned off in this state, the sensor 201 is located at the end of the hole in the disk 203, so there is a possibility that the sensor 201 will be displaced due to reaction.

Therefore, the timer TB is set to about 90 msec (T ₂ ) (74-8), and after the delay time, the lens clutch is turned off (74-9). This allows the lens to be reliably fixed and set at the same magnification position. The above steps are performed regardless of the position of the lens before movement. Also, the lens counter has nothing to do with it. Thereafter, the process returns to the main flow shown in FIG. 6-1 and continues.

Next, a change from the same size to reduced size 2 will be explained.

As with the same magnification, the lock plunger 208 and lens clutch 209 are sequentially turned on to start lens movement. When the signal of the counter sensor 201 becomes L again when the next hole 30-4' of the disk 203 is reached, the reduction 2 occurs.
Since the lens is shown to be in front of the lens, the plunger 208 is turned off and preparations are made to stop the lens.

This is the output hole 30- of the counter sensor 201.
At the falling edge corresponding to 1, the counter is incremented by 1, changing the previously set 7 to 8 (74-10). Further, the counter is increased by +1 corresponding to the hole 30-4 from 8 to 1. This is done by determining this (74-11) and performing a lock operation (74-6).

Thereafter, by the time the next hole 30-4 is sensed, the lens has reached the reduction 2 position, so the lens lock operation is confirmed as in the case of 1x magnification, and the lens clutch 209 is turned off via the timer TB (74-9).

To move and fix from the same magnification to the reduction 1, the counter sensor 201 senses the third hole 30-3' to turn off the lock plunger 208, and senses the fourth hole 30-3 to turn off the lens clutch. This is done by turning it off. This can be done by incrementing the counter by 1 every time the sensor 201 operates and sensing that the counter has reached 3 (74-12).

The same goes for moving from normal size to enlarged, and the fifth hole 3
0-4', the sixth hole 30-4 corresponds to each control,
The 5 on the counter is the standard (74-13). This is shown in Figure 16-2.

However, in the case of reduction 2 to enlargement, hole 30-4',
Hole 30-4 corresponds to enlargement position control, but reduction 2
They are the 3rd and 4th positions, respectively. In this case, the lens counter is set to 2 in advance, so
When the count of 3 by the counter sensor reaches 5, preparations are made to stop.

The same applies to others.

In this example, not only can lens movement control and lens fixation control be executed with a simple configuration, but also direct switching from first reduction to second reduction and switching to enlargement can be performed without complicated manual operations such as going through the same magnification. Can be executed.

Although the disks 203 and 204 are used, it is also possible to provide a concentric portion on one disk 203 corresponding to the equal-magnification cam and detect it optically or magnetically to obtain a signal from the disk 202. The above description can also be applied to control of movement selection and fixation of color filters and developing devices in color copiers.

By the way, if the routine shown in FIG. 6-4 is still being executed even after 7 seconds have passed after the lock plunger 208 is turned on, that is, if the lens is not fixed in a predetermined position, the routine shifts to routine X (74-14). Set the lens abnormality data in the register as shown below and serially transfer the data to the sequence MCOM (74-
15). And display segment data a to g (3rd -
(Figure 2) is selectively output controlled. This state is then latched until the main switch is turned off. The sequence MCOM side receives the lens abnormality data and blocks the copy operation. When the main switch is turned off
After clearing the RAM and input/output ports, the program proceeds to the main switch on determination routine 63 shown in FIG. 6-1 and waits. Therefore, by turning on the main switch again and repeating the magnification change input, it is possible to restart the computer program in case of any temporary inconvenience during execution.

The start of the lens timer TA is a sequence.
It is also possible to perform this in synchronization with when a lens position same magnification request is input from the MCOM (step 67 in FIG. 6-1, etc.) and when a copy key is input.

Next, the drive control of the total counter that counts the total number of copies will be explained with reference to FIG. 17. The key counter CNT1 is a counter that can be inserted and removed by the user, and is used to process the number of copies for each user. Each copy counts as 1, regardless of the

In addition, the total counter (CNT2), L counter (CNT3), and S counter (CNT4) cannot be removed and are used to count copy fees, etc. The total counter (CNT2) has nothing to do with paper size. The L counter (CNT3) counts 1 for each copy of large size paper, such as B4 size and A3 size, and the S counter (CNT4) counts 1 for each copy of small size paper. Paper that is A4
It is counted by 1 when the copy is less than the size.

When a small size copy is made,
The SCNTD signal from MCOMQ102 goes high, turns on Q201 and Q202 through R206, and drives CNT1, CNT2, and CNT4.

Also, when a large size copy is made,
The LCNTD signal becomes 'H' from MCOMQ102, Q203 and Q204 are turned on through R208, and CNT1, CNT2, and CNT3 are driven. (Step 271 in Figure 7-3). And D205 is a diode to make the drive timing of CNT1 and CNT2 the same, and D20
7. D208 is a diode that forms an OR circuit with a small size drive signal and a large size drive signal, and is used to drive CNT1 and CNT2. D206 and D209 are diodes used to detect that the key counter is removed. It is.

If the key counter (CNT1) is removed before the copy key is turned on, the power is supplied through the counter (CNT1). CNT2, CNT3, CNT
Since the 24V power supply to 4 is turned off, the key counter presence/absence signal (CCNTi) goes to 'L' level, inputs the fact that the counter is removed to _i2 of MCOMQ 102, and prohibits the reception of copy keys.

Also, if the key counter is removed during the copy operation, it will be in the same state as when the preset copy operation has finished (6th
Figure-1, 76-1).

Power is also supplied to the paper feed solenoids SL1 and SL2 of the upper and lower pick-up rollers through the counter. Therefore, if the key counter is removed after the copy key is turned on to start a copy cycle, the paper feed solenoid will stop moving and normal paper feeding will not be possible. In other words, even if you try to use the key counter illegally, you will not be able to make a normal copy.

In addition, D201, D202, D210, D211
is a diode that absorbs the reverse voltage when driving the solenoid or counter and protects the driving element.

Also, in this example, the paper feed solenoid is activated after the copy key is turned on.
If the key counter is removed during operation of the SOL1 etc. after it has started operating, the solenoid current is similarly cut off and paper feeding is interrupted with the sheet held in the pick-up roller. Therefore, even if the key counter counts up after paper feeding is completed, unauthorized copying cannot be made.

In addition, if you set the key counter again after paper feeding is interrupted as described above, then turn on the copy key and restart, the interrupted sheet will continue to be fed at the predetermined timing without causing a jam, and the registration roller will It is regulated in the transport and contributes to transcription.

As shown in Figure 6-1, if the key counter input judgment (76-1) indicates that an interrupt copy is in progress, the interrupt is canceled (82), the original copy mode is returned, and each key input is enabled. (77) Further mentioned above
Start a 60 second, 2 hour timer.

As described above, this example is particularly effective for sequence control by inputting the key counter state detection signal to a microcomputer.

The temperature control circuit of the fixing heater shown in FIG. 8 will be explained.

Q106 is a one-chip comparator containing four circuits, and Q106-1 to Q106-4 are functionally independent from each other. The thermistor TH1 is placed in contact with or near the fixing roller, and is designed to detect the temperature of the fixing roller. Also, thermistor TH1
has the characteristic that the lower the temperature, the higher the resistance.

Comparator Q106-1 is thermistor TH
1, R127, R133, R132
A bridge circuit is formed and thermistor TH1 is approximately
When the temperature is below 50℃ or when the wire is disconnected, comparator Q1
The output of 06-1 is approximately 0V, which turns on LED 101 and is input to Q101 to inform MCOMQ101 that the current temperature is low or the thermistor is disconnected. This is determined in step 596 of Figure 7-6.

Also, comparator Q106-2 is a thermistor.
TH1, R127, R128, VR102, R1
29, R130, and R131 form a second bridge circuit, and when the thermistor reaches a temperature of 170°C or higher, the output of comparator Q106-2 becomes “H”, indicating that MCOMQ101 has a temperature of 170°C or higher (wait up). In order to convey the information, Q101
is input. That is step 73 in Figure 7-1.
-1 is determined.

Also, comparator Q106-4 is a thermistor.
A bridge circuit is formed by TH1, R127, R134, and R135, and when the thermistor is below 150°C, Q106-4 becomes "L" level,
The LED 102 turns on and displays. Then, it is input to Q101 to inform MCOMQ101 that the temperature of the fixing roller is 150° C. or lower. This is No. 7-1
The determination is made at 71 in the figure.

Also, comparator Q106-3 is a thermistor.
TH1, R127, R128, VR102, R1
29, R130, and R131 form a bridge circuit, and when the temperature of the fixing roller reaches 180°C or higher,
The output of comparator Q106-3 becomes "H". By the way, C126 in parallel with thermistor TH1
are noise absorption capacitors D113, D114,
D111 and D112 are similar protection diodes, and R123-1 is a comparator Q106.
This is a protective resistor. Also, R123-2, R12
3-4, R123-3 is a constant current source for supplying stable power to the thermistor TH1 and the bridge circuit.

When the fixing roller is below 180℃, comparator Q
The output of 106-3 is L, and the driver Q
The output of Q114 becomes H, and is charged to C111 through RA126-4, the output of Q109 becomes H, and the output of Q116 becomes L. Also, RA12
7-1 connects the output of Q116 to comparator Q10
It feeds back to the inverting input of No. 9 to form positive feedback.

When Q116-16 becomes “L”, LED103
is driven, and the fixing heater control SSR is also driven to turn on the fixing heater. When the temperature of the fixing roller exceeds 180℃, the comparator Q106-3
The output of C1 becomes “H”, Q114 turns on, and C1
14 is discharged and the non-inverting input 3 of Q109
voltage decreases, the output of Q109 becomes "L", Q116 is turned off, SSR is turned off, and the fixing heater is turned off. As mentioned above, turn on the heater.
It can be turned off to keep the temperature of the fixing roller constant at 180℃.

By the way, since the temperature is low when the power is turned on, comparator Q106-3 turns on the heater via Q109, but RA126-4 and RA12
7-2, due to the time constant circuit of C111, the output of the comparator Q109 does not become H immediately. Therefore, the rush current when the power is turned on can be suppressed.

Also, this time constant circuit RA127-4, RA12
7-2, C111 can prevent noise or rapid repetition of turning on and off in the heater around 180°.

By the way, when a jam is detected, relay K101 is driven by the output of O5 of the expansion port shown in FIG. 3-1, and the contact of K101 is fixed to the 1 side. This K101 is a latching relay, and has the characteristic of mechanically maintaining that state once it is driven. Then, by driving a coil other than the driven coil, the contact can be reset. Therefore, in the case of a jam, the contact of K101 is fixed to the 1 side until the jam is reset, so the charge of C111 is discharged through the diodes D133 and R126-4, and the output of Q109 becomes L, and the fixing heater is off. In this way, since the circuit does not suddenly turn off when jammed, no overcurrent occurs when it is turned off. Even when attempting to resume copying after a jam reset, inrush current can be similarly prevented by the action of C111.

Also, if any abnormality is detected in MCOMQ101 or Q102, Q11 will be sent through DA105.
4 and turn off the fixing heater in the same way as above.

As described above, the fixing heater control circuit of this example is
It stably controls the fuser at 180°C, and also has a function to automatically turn off the fuser heater in the event of a jam or abnormality in the control system with a simple configuration. In addition, a signal is input to the MCOM for each state depending on the temperature of the heater, and weight control as shown in FIG. 7-1 is performed based on the judgment, so that more detailed weight and optimum sequence control can be safely performed.

The AC drive control circuit shown in FIG. 3-3 will be explained in detail.
First, P1 is a power cord and a power plug, and commercial power is applied to the serviceman switch SW1 via P1 and the nozzle filter LF1.
The main purpose of SW1 is to turn off all power during maintenance of the copying machine.
First, one side is applied to the power transformer T2 via the circuit breaker CB-1, and the output of T2 is transmitted from the terminals J6-1 and 2 to the DC power supply circuit shown in Figure 11.
Applied as AC low voltage input to create DC5V output. Next, from SW1, there is a door switch MS.
1. First, connect the circuit breaker via MS2.
CB2, drum heater H1, and terminal J302-6 on AC driver circuit 300, photo SCRQ
309 and the terminal J302-10, a power supply route for the photosensitive drum heat retention function using the drum heater H1 is formed.

Heat exhaust fan that exhausts heat from the fixing device to the outside of the machine
FM1, power transformer T1, T3 are SW2 (501)
Power is applied only to T1 through the circuit breaker 3, and the secondary output from T1 is rectified by the diode bridge D1, and the DC power is supplied to the DC power supply circuit in Fig. 11. is applied as . Further, the secondary output from T3 is outputted as a power source for controlling a document feeder (not shown). Next, the webbing motor M2 is a motor that gradually winds up the webbing that is pressed against the roller in order to clean the developing material attached to the upper fixing roller.The blower motor FM2 whose main purpose is to cool the original glass, and the transfer motor A conveyor fan whose main purpose is to use wind pressure to keep the copy paper in close contact with the conveyor belt when conveying the copy paper to the fixing device after the process.
AC driver circuit 300 connected in parallel with FM3
is driven by solid state relay Q306 during copy execution. Furthermore, Q306 has a cleaning web 20 (first
(Fig.) is also driven.

Next, one terminal of the document exposure lamp LA1 is connected to one power source via the temperature fuse FU2 for preventing excessive temperature rise, and the other terminal is connected to the relay K301.
Connected to the normally closed contact terminal of the Also, one terminal of the lower heater H3, whose main purpose is to keep the fixing roller warm in the fixing unit, is connected to one power source via the temperature fuse FU1, and the other terminal is connected to the normally closed contact terminal of the relay K301. Connected. Also, the common terminal of K301 is the AC constant voltage control unit.
It is connected to the other power supply via triac Q-C1 in CVR1. The purpose of this circuit, in addition to preventing the total power from increasing due to both heater H3 and lamp LA1 being turned on, is to first switch the contact of K301 only when triac Q-C1 is turned off. protection of contacts and AC constant voltage control unit
The purpose is to stabilize the voltage applied to LA1 with 11 CVRs, and also stabilize the voltage applied to lower heater H3. The lower heater H3 is the upper heater H2
At the same time, the lower and upper rollers of the fixing roller are heated, and the rollers are equipped with a thermistor.
TH1 is brought into pressure contact and the temperature is detected thereby, and the temperature is controlled to be constant by switching the solid state relay Q1 using the output of Q109 as described above. Furthermore, by installing a temperature fuse FU1 near the upper roller and making the connections shown in Figure 3-3, excessive temperature rise is prevented.However, for the lower roller, this type of control and protection is expensive. It is not installed from above. Therefore, the lower heater H3 must be given a low power rating with enough margin to prevent the temperature from rising too much if the input voltage is simply applied due to fluctuations in the input power supply voltage and even variations in the rating of the heater itself. The aforementioned energizing circuit to H3 allows the power rating to be set as high as possible within a range that does not harm the roller material, resulting in extremely high efficiency and, as will be explained later, the voltage output from CVR1 itself can be controlled. Therefore, the circuit is designed to enable automatic power control that takes into account room temperature and other various influences.

The internal details of the AC constant voltage control unit CVR1 are omitted, but when +24V is applied to terminal 1 and OV is applied to terminal 2, and a voltage of 10V DC or less is applied to terminal 5, it is applied to the load by phase control by triac Q-C1. When the voltage is controlled to a constant effective value of 50V and a DC voltage of 16V or more is applied to terminal 5, the effective value
It is controlled at a constant 80V, and furthermore, it can be controlled to change linearly in response to the effective output value from 50V to 80V between 10V and 16V, and of course relay K3
The current flowing through the coils of the 1st and 2nd terminals of 01 to control the contacts has a correlation with the switching of the set voltage by CVR1, and is controlled as control switching between LA1 and H3. In addition, the thermistor TH1 mentioned above has two
contacts, namely J51-2, 3rd terminal and J51-
It is connected using terminals 5 and 6. In addition, the signal LHSRD is set to MCOMQ in accordance with the off timing of CVR.
101 is output to switch between the heater and the lamp.
The fixed time before and after switching relay K301 is the first
By turning off the CVR output as shown in Fig. 9, overcurrent can be prevented during switching by relay K301.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a copying apparatus to which the present invention can be applied, FIG. 2 is a plan view of the copying apparatus shown in FIG.
Figures 1, 3-2, and 3-3 are control circuit diagrams of the copying machine in Figure 1, Figures 4-1 and 4-2 are input/output operation time charts of Figure 4, and Figure 5 Figure-1 and Figure 5-2 are main motor drive block diagrams, Figure 6-
Figures 1 to 6-4 are control flowcharts by the management computer, Figures 7-1 to 7-6 are control flowcharts by the sequence computer, and Figure 8 is a flowchart of control by the sequence computer. 9 is a plan view of the document platen stand of the copying machine shown in FIG. 1; FIG. 10 is a diagram showing serial transfer data;
Fig. 11 is a power supply circuit diagram, Fig. 12 is a reset circuit diagram, Fig. 13 is a schematic diagram of the vicinity of the scanning section, Fig. 14 is a perspective view of the scanning section, Fig. 15 is a plan view of the lens control disk, and Fig. 16- 1 and 16-2 are time charts of lens control, FIGS. 17 and 18 are other control circuit diagrams, and FIG. 19 is a time chart of FIG. 18. In the figure, 30-1 is a lens at the same-size copying position, 1 is a photosensitive drum, 23 is an exposure lamp that scans, 24, 25 is a mirror system that scans, 13 is an upper paper feed cassette, and 14 is a lower paper feed cassette. , 46 is a sorter.

Claims (1)

[Scope of Claims] 1. A scanning means for scanning a document, a driving means for reciprocating the scanning means starting from a home position position, and a first detection means for detecting the scanning means at the home position position; a second detection means that is provided upstream of the first detection means in the backward movement direction of the scanning means and detects the scanning means; A document scanning device that detects the scanning means and stops driving the driving means, further comprising a timer for measuring time from the time when the second detection means detects the scanning means, during the backward movement of the scanning means; An original scanning device characterized in that when the measurement result from the timer becomes longer than a first predetermined time set in advance, the driving means is activated again to drive the scanning means in the backward movement direction. 2. If the measurement result from the timer exceeds a second preset time that is greater than the first predetermined time, stop driving the drive means and display that the device is abnormal. A document scanning device according to claim 1, characterized in that: