JPS6252308B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an image forming apparatus such as a copying machine. Conventionally, especially in liquid development copiers, if you stop the machine and leave it for a long time, the developer remaining on the photoreceptor surface dries and becomes difficult to wipe off, making it impossible to make the first copy when the machine is restarted. This often resulted in stains. On the other hand, it is inconvenient to perform sufficient preliminary cleaning at the time of restart, since this will reduce the copying speed. The present invention eliminates the above-mentioned drawbacks, speeds up the restart of copying when left unattended regardless of power cutoff, and enables the formation of high-quality images even after any condition occurs in the machine. Furthermore, if image quality is not an issue, copying can be started immediately. One feature of the present invention is that it has two cassette stands, upper and lower, so that two types of cassettes (or two of the same cassette) can be set at any time. Selection of the upper and lower cassette stands can be made with a single touch using the selection key on the operation panel, and the set cassette sizes are displayed on the operation panel for both the upper and lower cassettes. Another feature is that in consideration of ease of use, the information and operations necessary for copying operations are centrally located on the operation panel on the front right hand side. What's more, the panel uses a touch sensor, allowing you to operate it with just a light touch. In addition, the transfer copying machine uses a roller development method,
Ensures faithful reproducibility in both line copy and solid copy. In addition, a potential sensor detects the surface potential of the photosensitive drum, which is an important factor in the image forming process, and if it is outside the specified range, it is quickly restored.
An automatic control circuit is provided which ensures constant contrast at all times. Also, during standby, the rotation of the drive part is stopped,
A timing belt is also used for drive transmission to reduce noise generated from the machine. In addition, a one-chip microcomputer is used at the heart of the electrical control to integrate the circuit and improve reliability, as well as a self-diagnosis function and a fail-safe function in the event of trouble. FIG. 1 is a perspective view of a copying machine according to the present invention.
In the figure, 1 is the tray for storing copied paper, 2 is the top cover of the main unit, 3 is the rear cover of the main unit, 4 is the top left door that can be opened and closed, 5 is the original cover, 6 is the operation cover, 7 is the right cover, 8 is an operation panel, 9 is a power switch that supplies power to most of the main unit, 10, 11
12 is a carrying handle, 13 is a key counter socket, and 14 is a front door that can be opened and closed. FIG. 2 is a plan view of the operating section 8 of FIG. 1. In the figure, 28 and 29 are keys for selecting the lower and upper cassettes, 30 is a slide lever for setting the copy density, and position 5 is the standard density. 3
1 is a numerical key for setting the number of copies, 32
is the clear key to cancel the value,
33 is an interrupt key for executing copying of another number before the copying of the set number by key 31 is completed;
4 is a copy key for commanding the start of copying, 3
Numeral 5 is a stop key for stopping the copying operation during continuous copying of a set number, and since these keys use a flat type touch sensor, they are extremely easy to operate. The copy key is 90
±50gr, other keys will switch when pressed at 120±50gr, and will return when no longer pressed. 15 to 21 are warning indicators from the main unit, all of which are displayed as pictograms. Reference numeral 15 is a paper feed check indicator that lights up when copy paper jams inside the machine, when the original illumination lamp lights up abnormally, or when no signal is generated from the Hall IC under the optical mirror rail. 16 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 17 denotes a replenishment liquid replenishment indicator, which lights up when the amount of developer in the developing device falls below a specified amount. Reference numeral 18 denotes a toner replenishment indicator that starts to light up when toner is no longer replenished (when the toner bolt becomes empty) even though the toner concentration in the developer in the developing device is below a specified value. Numeral 19 is a key counter check indicator that lights up when the key counter is not inserted into the socket of the main body. 23 is the wait/copying indicator and this display is
(1) When you turn on the power switch, the fuser heater temperature will blink if it is lower than the specified value. (2) It will stay lit from the time you press the copy start key until the end of exposure for the final copy, so it is time to replace the original. is easily recognized. Reference numeral 20 is a copy number set display, and when the desired number of copies is set using the numeric keypad, the set number of copies is displayed in seven segments. You can set 1 to 99 sheets at a time. The number of sheets set will automatically return to 01 when 30 seconds have passed after copying is completed or when the clear key is turned on. Reference numeral 22 denotes a copy number display. When a copying operation starts, a count is displayed for each copy, and the count is added and displayed until it matches the set number of copies. 21 is an interrupt indicator that lights up when the interrupt key is pressed and goes out after the interrupt copy is completed. Upper and lower cassette size indicators 24 and 25 display the sizes of the cassettes set in both the upper and lower tiers. This display allows you to see the sizes of the upper and lower cassettes at the same time. 26 and 27 display whichever key 28 or 29 is turned on (cassette stage). FIG. 3 is a sectional view of the copying machine shown in FIG.
The structure and operation will be explained with reference to FIGS. The surface of the drum 47 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 71 activated when the copy key is turned on. Start. When the drum 47 rotates by a predetermined angle, the original placed on the original platen glass 54 is moved to the first scanning mirror 44.
illuminated by an illumination lamp 46 integrally configured with
The reflected light is scanned by the first scanning mirror 44 and the second scanning mirror 53. The first scanning mirror 44 and the second scanning mirror 53 move at a speed ratio of 1:1/2, so that the original is scanned while the optical path length in front of the lens 52 is always kept constant. The above reflected light image shows the lens 52 and the third mirror 21.
After passing through, an image is formed on a drum 47 at an exposure section. The drum 47 is simultaneously neutralized by a pre-exposure lamp 50 and a pre-AC charger 51, and then charged by a primary charger 51.
It is corona charged (for example, +). Thereafter, the drum 47 is the exposure section, and the image irradiated by the illumination lamp 46 is slit-exposed. At the same time, AC or corona charge removal with a polarity opposite to the primary one (for example -) is performed by a charge remover 69, and then a high-contrast electrostatic latent image is formed on the drum 47 by uniform surface exposure using a full-surface exposure lamp 68. The electrostatic latent image on the photosensitive drum 47 is then developed with liquid by the developing roller 65 of the developing device 62 and visualized as a toner image, and the toner image is easily transferred by the pre-transfer charger 61. Upper cassette 10 or lower cassette 11
The transfer paper inside is fed into the machine by a paper feed roller 59, and is sent toward the photosensitive drum 47 with accurate timing by a register roller 60, so that the leading edge of the latent image and the leading edge of the paper are aligned at the transfer section. Can be done. Next, while the transfer paper passes between the transfer charger 42 and the drum 47, the toner image on the drum 47 is transferred onto the transfer paper. After the transfer is completed, the transfer paper is separated from the drum 47 by the separation roller 43, sent to the conveyance roller 41, guided between the hot plate 38 and press rollers 40, 41, and fixed by pressure and heat. The paper is discharged to the tray 34 by the discharge roller 37 via the paper detection roller 36 . After the transfer, the drum 11 continues to rotate and its surface is cleaned by a cleaning device comprising a cleaning roller 48 and an elastic blade 49, and the process proceeds to the next cycle. As a cycle executed prior to the above copy cycle, there is a step of pouring a developer into the cleaning blade 49 while the drum 47 is stopped after the power switch 9 is turned on. Hereinafter referred to as Priwetsu.
This is to flush out the toner accumulated near the cleaning blade 49 and to provide lubrication to the contact surface between the blade 49 and the drum 47.
After the prewetting time (4 seconds), the drum 47 is rotated, the residual potential and memory of the drum 47 are erased by the pre-exposure lamp 50, the pre-AC static eliminator 51, etc., and the drum surface is cleaned by the cleaning roller 48 and cleaning blade 49. There are steps. Hereinafter, this will be referred to as forward rotation. This is to make the sensitivity of the drum 47 appropriate and to form an image on a clean surface. The pre-wet time and pre-rotation time (number) are automatically changed depending on various conditions (described later). Also, as a cycle after the number of copy cycles set by the number key 31 is completed, the drum 4
There is a step in which the drum 7 is rotated several times to remove residual charges and memory on the drum using an AC charger 69 or the like, and to clean the drum surface. Hereinafter, this will be referred to as post-rotation.
This is to leave the drum 47 electrostatically and physically clean. In the apparatus, reference numeral 45 denotes a standard white plate provided at the end of the glass 54, and the reflected light is involved in setting the bias voltage of the developing roller 65. Reference numeral 67 denotes a surface potential meter installed near the drum to measure the surface potential at the center of the drum.The potential is detected by an AC waveform obtained by rotating the cage-shaped rotating body, and compared with a predetermined value, the charger 51 , 69 and the bias voltage of the developing roller 65. It has a motor that rotates the rotating body. 56 is a blower for cooling the inside of the machine, and controls the process sequence. 57 and 58 are lamps and CdS for detecting the presence or absence of paper in each of the upper and lower cassettes. Although not shown, the upper left door 4 and front door 14 of the main body
A door switch is provided which is turned on when both are closed, and when the door switch is turned off, a part of the power supply that cannot be shut off even if the power switch 9 is turned off is also turned off.
Furthermore, a sub-switch is provided inside the main body to shut off all remaining power (central control unit). This sub-switch has the same function as when the copier power cord is unplugged from the office outlet. This machine has the feature that the operating status of the door switch and power switch is read into the control circuit as a signal and used as conditions for control processing. (Optical System) FIG. 4-1 is a partial sectional view of the optical system in FIG. 3, and the numbers are the same as in FIG. 3. In the figure, l ₁ is an approach area, l ₂ is an effective scanning area, and l ₃ is an overrun area. Normally, the forward movement ends at a maximum of l ₁ +l ₂ and the backward movement process begins (hereinafter referred to as reversal). HAL1 is a Hall element installed at a predetermined position corresponding to the first mirror stop position before starting, HAL2 and HAL3 are Hall elements installed in the middle of the first mirror forward path, and MS4 is installed at the end of the overrun area of the first mirror. It is a micro switch. HALs 1 to 3 operate when a magnet provided on the base approaches the first mirror as it moves, and outputs a high-level signal.
The signals serve as conditions for controlling the stop of the optical system, controlling the operation of the paper feed roller and lighting of the document illumination lamp, and controlling the operation of the registration rollers. MS4 is for forcibly and preferentially stopping the forward movement of the optical system at a predetermined position when the first mirror is not reversed at this position. This prevents the optical system from rushing toward the other end of the main body due to trouble with the optical system control section, and can prevent damage to the equipment. The optical system has three inversion positions in _l2 (corresponding to A4 size, B4 size, and A3 size), which means that the pulses generated by the rotation of the main motor 71 are
After passing through HAL2 of the mirror, a predetermined count is made for each size and corresponds to the position where the backward motion control is performed. (Exposure Section) FIG. 4-2 is a plan view of the vicinity of the blank lamp 70 in FIG. 3. The blank exposure lamps 70-1 to 70-5 are turned on while the drum is rotating, except during exposure, to erase charges on the drum surface and prevent excess toner from adhering to the drum. However, since the blank exposure lamp 70-1 illuminates the drum surface corresponding to the potential sensor 35, it is turned off momentarily when measuring the dark area potential with the potential sensor. Furthermore, in B-size copying, the image area is smaller than A4 or A3 size, so the blank exposure lamp 70-5 is turned on for the non-image area even when the optical system is moving forward. The lamp 70-0 is called a sharp cut lamp, and it irradiates light onto the portion of the drum that is in contact with the separation guide plate 43-1, completely erasing the charge on that portion and preventing toner from adhering to it. I try not to contaminate the width of the separation chip. This sharp cut lamp is always lit while the drum is rotating. (Developing Device) FIG. 5-1 is a sectional view of the developing device, FIG. 5-2 is a sectional view of the developing roller, and FIG. 5-3 is a perspective view of the era roller. In the figure, 100 is a conductive sponge containing the developer in the developing roller 65, 101 is a net-like insulating part covering the sponge 100, and 102 is a metal roller surrounded by the sponge 100, to which a bias voltage is applied by a DC power supply 103. . 105 is a refresh roller, and 107 is a developing electrode. The developing roller is immersed in developer during standby. When copying begins, it contacts the drum surface with constant pressure and begins to rotate counterclockwise in synchronization with the peripheral speed of the drum. First, edge development is performed using a developer accumulated between the auxiliary electrode plate 104 and the developing roller 65 (area a). Next, the developing roller 6
5 is in pressure contact with the drum surface, near field development is performed using the developer seeped out from the sponge 100 of the developing roller (region b). Furthermore, the restoring force of the sponge in the developing roller when the developing roller separates from the drum surface is used to absorb excess developer on the drum surface after development into the developing roller (region c). Furthermore, fogging is prevented as much as possible by adjusting the bias voltage of the developing roller 65. During copying, the developing roller is wedge-shaped between the refresh roller 105 and the drum, and is rotated in pressure contact with the drum. When the developing roller in the portion that is in pressure contact with the drum surface discharges the developer contained in the sponge and leaves the drum, the sponge expands and absorbs (squeezes out) excess liquid on the drum surface. Further, when the sponge 100 comes into pressure contact with the refresh roller 105, the old developer contained in the sponge 100 is expelled, and when the sponge 100 is separated from the refresh roller 105, it absorbs fresh developer again. Since it is necessary to fill the space between the refresh roller and the developing roller with sufficient developer, the developing electrode 10
7 is provided. In order to prevent dirt from adhering to the developing electrode 107, the same bias voltage as that of the developing roller 65 is applied. In this way, each time the developing roller rotates, the cycle of discharge → absorption → discharge → absorption is repeated. A cleaner blade 106 of the developing roller removes toner lumps adhering to the mesh of the developing roller to prevent clogging of the mesh. This improves the clarity of the copy image quality. A pump motor (not shown) pumps the developer in the container onto the auxiliary electrode 104 and onto the cleaning blade 49.
is pumped up at the same time. Further, the developing roller 65 is in the state shown in the figure only during development, and at other times it descends to separate from the drum surface. This prevents toner from being deposited on the drum surface unnecessarily and prevents the sponge from deforming. FIG. 6 is a transmission block diagram of the drive system in FIG. 3. The two-digit numbers in the figure are the same as those in FIG. 3, and 601 to 603 are synchronized belts that transmit power from the main motor, 604 is a gear that transmits power from the main motor to the drum 47, and 60
5 is a gear that transmits drive to the separation roller 43; 606;
- 608 are clutches, and 609 and 610 are solenoids that move the paper feed roller, which is constantly rotating after the power supply 9 is turned on, up and down on the paper. When the main motor 71 starts rotating, the drum,
The developing roller is rotated via a separation roller, a conveyance mechanism, and a refresh roller. Further, at the same time as the main motor starts operating, the developing roller is pulled up by the torque motor and brought into pressure contact with the drum surface. When the forward clutch CL-1 or the reverse clutch CL-2 is actuated, the optical system is driven by the main motor and moves forward or backward. Copy paper is fed into the machine by lowering a paper feed roller upon generation of a paper feed signal. Timing clutch CL-3 drives the timing roller. In this way, the driving necessary for the copying operation is performed by one main motor 71. In addition, there is a torque motor (described later) that moves the developing roller 65 up and down, and a motor that stirs the liquid in the developing device 62 and pumps the liquid to the blade 49 and the developing electrode. In addition to the aforementioned exhaust blower motor, there is also a first intake fan motor that cools the vicinity of the fixing device, and a second intake fan motor that cools the vicinity of the developer, which are synchronously controlled. FIG. 7 is a block diagram of the electrical control system in FIG. 3. In the figure, 701 is a plug that is inserted into an outlet, 702 is a power supply circuit for supplying stable DC voltage to the control unit, 703 is an alternating current (AC) load such as a main motor, and 704 is an amplifier etc. for driving the load 703. AC driver, 705 is direct current (DC) load such as clutch, solenoid, etc., 706 is
This is a DC control unit that controls timing operations of the AC load 703 and DC load 705, lighting of each indicator on the operation unit 8, operation of the automatic control system, operation of self-diagnosis, etc., and is controlled by the keys on the operation unit 8. Signal, state detection sensor (Hall element, micro switch, etc.)
The above control is performed by inputting a signal from the surface potential control section 708 and a specific signal from the surface potential control section 708. (Sequence) FIG. 8 is a time chart of each sequence step. When the sub switch SW1 is turned on and the power switch SW2 is turned on, the prewetting operation (PWET) is performed for approximately 4 seconds. Next, one rotation of the drum forward rotation (INTR) is performed. Next, after the control rotation (CONTR), if the copy key is not turned on, the fourth standby state (STBY4) is reached. The control rotation N is a drum rotation in which a potential sensor alternately measures the potential of a bright area and a dark area each time the drum rotates, and a surface potential control circuit brings the potential of the drum surface closer to a target value. Controlled rotations N are performed up to a maximum of three rotations. In control rotation 1, the drum rotates only 0.6 times, and during this period, both the bright and dark potentials are controlled only once. The control rotation 2 is for measuring the bright area potential with a standard amount of light from the original illumination lamp immediately before starting copying, and determining the bias value for the developing roller.
When copying is started, control rotation 2 is always executed. However, if there is no copy signal,
This controlled rotation 2 becomes a mere idle rotation. In post-rotation (LSTR), the drum is rotated an additional 1.12 times after copying is completed, and during this period, the AC charger, pre-exposure lamp, blank exposure lamp, and full-surface exposure lamp are operated to electrostatically clean the drum surface. During LSTR, the AC charger current is approximately 100 μA (usually
200μA) to prevent the drum surface from becoming too negative. The reason why the LSTR is rotated 1.12 times is because the positive potential between the positive charger and the AC charger is higher than other parts, so static electricity is removed twice to eliminate uneven static removal. STBY1 to STBY4 indicate that the drum is stopped and in a standby state after LSTR ends. control of microcomputers over time.
Standby changes from STBY1 to STBY4 (within 30 seconds each, then within 30 minutes, then 5
(within 5 hours, over 5 hours). The start sequence will differ depending on which state STBY is in when you press the next copy start key. When the copy start key is on (No. 8-2)
Figure) SCFW is in forward mode. Here, the document illumination lamp is turned on, and the document image is projected through the mirror and lens in synchronization with the circumferential speed of the photosensitive drum. Also, during SCFW, the movement of the copy paper is controlled as described above by the Hall IC on the optical rail.
The inverted signal is output from the microcomputer CPU according to the cassette size by adding the clock pulses after the generation of the transport timing signal. SCRV is in reverse mode, and the optical system returns to the stopped position at approximately twice the speed of forward movement. If you want to continue copying,
The document illumination lamp is re-lit by a signal from the Hall element for paper feeding control during reverse mode. For the final copy, a period of 16 clocks (40 mm) is provided between the time the optical mirror returns to the home position and the time it enters the LSTR. This is to ensure reliable transfer to the trailing edge of the copy paper.
After 16 clocks, the AC charger facing the LSTR is switched to weak AC, the other chargers are turned off, the developing roller descends, and the drum surface is electrostatically cleaned. Regarding the turning on of the copy start key in each of the above process modes, in FIG. 9, in the process mode, no matter when the copy start key is pressed, the optical system always starts after execution up to control rotation 2 (CR2). Surface potential control was performed 4 times for both V _L and V _D.
Then, the developing roller bias is determined by control rotation 2 (CR2). When the copy start key is pressed during control rotation 2 (CR2) in the mode, the mode immediately shifts to CR2, the developing roller bias is determined, and the optical system starts. If the copy start key is pressed during post-rotation (LSTR) mode, LSTR will be completed.
INTR is 192 clocks (1.13 revolutions). The reason for this is to increase the time during which the developing roller is brought into pressure contact with the drum surface and the stable lighting time of the full-surface exposure lamp. mode, immediately forward rotation (same as
INTR). Since it is within 30 seconds from the end of the previous copy, potential control is executed using the previous control value, and correction control is not performed particularly during this time. However, CR2
is executed. When in mode, it starts with 2 full rotations due to 1 clock INTR. Surface potential control is V _L ,
Both V _{and D} are executed once. When in mode, it rotates 3 times and starts. Since some time has passed since the last copy was completed, surface potential control is executed twice for both V _L and V _D. The mode is the same as the case. The following sequence occurs when the cover is opened due to a jam during copying, when the power switch is turned off during standby, and when the power switch is next turned on within 5 hours. If the copy start key is pressed before CR1, the copy operation will start; if it is not pressed, after CR2.
LSTR becomes STRY. The mode is the same as the case when more than 5 hours have passed. If you do not press the copy start key,
After CR2, LSTR becomes STBY. If you turn off power switch SW2 before CR2 in the case and turn it on again, PRE-WET
The sequence starts from. Also after LSTR
If SW2 is turned off and on, the sequence will be either case or case. Also, if the power switch is turned off during the copy cycle, the drum will immediately move to LSTR and stop after LSTR ends. Time measurements for 30 seconds, 30 minutes, and 5 hours are made from the drum rotation stop, regardless of standby or power switch off. This is done by a long timer function in the computer program unless the subswitch is turned off. The above control is performed according to the elapsed time of the timer when the start key and power switch are restarted. The mode is when the optical mirror of the final copy advances.
If the copy start key is pressed between PF and PF′ when the optical mirror is moving backward, the illumination lamp will turn on at PF′ (original illumination lamp lighting signal) while the optical mirror is moving backward, and the optical mirror will return to the stop position immediately. The next copy cycle begins. The situation is the same as continuous copying. Mode is final copy optical mirror moving backwards
If you press the copy start key after passing PF′ and before returning to the stop position, PF′ (original illumination lamp lighting signal) has already passed, so after the optical mirror returns to the stop position, 17 A clock is counted, the document illumination lamp is turned on during this period, and the next copy cycle begins. The mode is when the start key is turned on during 16 clocks, and the operation is the same as the immediate mode. Even if you turn on the start key before the mode (last copy), the CPU will not accept it. The same applies to numerical keys. Note that PF' of the final copy is not generated as a signal. 9-1 and 9-2 are operation timing diagrams of each operating load of the device. The former is a timing diagram when the copy key is not turned on after the main switch is turned on, and the latter is a timing diagram when the copy key is turned on. In the figure, DRMD is a signal to drive the main motor, HVDC is a signal to energize a high-voltage transformer that supplies voltage to each DC charger and front AC charger, and HVAC
is the signal to energize the transformer that simultaneously supplies voltage to the AC charger, BLWD is the signal to drive the blower F1, fan F2, and developer cooling fan F3 to cool the inside of the machine, and DVLD is the drive signal for the motor that pumps up and stirs the developer. , RLUD is a signal to raise and lower the developing roller, and TSE is a signal to activate ATR and turn on the liquid concentration detection lamp. DVLB is a signal for applying bias voltage to the developing roller and electrode,
PF is paper feed position signal, RG is registration position signal,
OHP is the optical system stop position signal, FWCD is the forward clutch on signal, RVCED is the reverse clutch on signal, PFSD is the paper feed solenoid activation signal, RGCD
is the register clutch activation signal, IEXP is the original exposure lamp on signal, SEXP is the signal to set the standard light intensity, BEXP is the blank lamp on signal, STBM
is a signal that turns off only the standard blank lamp. V _L1 , V _D , and V _L2 are the potential measurement signals that are necessary to detect the dark surface potential using this lamp. ISP is the initial reset pulse signal for potential measurement. SMD is the surface potential. This is the signal that rotates the meter. The numbers in the figure are the number of pulses CL generated by the rotation of the main motor. The operation on/off of each load is determined by the number of pulses from the operation change point to the change point.
Since it is stored in the ROM, it is counted by the CPU. Also, full exposure lamp FL1, front exposure lamp FL2,
The sharp cut lamp LA901 and the blank lamp LA906 (for B size) are operated in synchronization with the drive signal of the main motor. The output of the high voltage AC transformer is reduced to about half during the process during LSTR. Also blank clamp
LA906 (for A size) and the remaining blank lamps LA903 to LA905 correspond in operation timing to the BEXP signal. Since the operation of each part is clear from the time chart, the explanation will be omitted. Note that symbols such as R and D indicate that the signal is output from the corresponding port of the CPU. (Control Circuit) FIG. 10 is a circuit diagram of the DC control section. 1 in the diagram
11 is a central processing unit that reads input signals to input terminals I ₁ to _{I 6} , performs logical decoding and arithmetic processing, and outputs predetermined signals (timing operation signal, display signal) from output terminals O ₁ to _{O 36} A CPU, for example, consisting of a computer chip element. 112 is a matrix circuit for inputting signals from key operations of the operation unit, detection operations of Hall elements, etc. to the input ports I ₁ to I ₄ , and 115 is for inputting one of the input conditions in the matrix circuit 112 to the input ports. A decoder that outputs probe signals (scanning signals) for decoding and outputting signals from output ports _O13 to _O16 . A generator 113 generates a series of pulses in response to the rotation of the main motor (drum rotation), and inputs the pulses to the CPU in order to determine the drive timing of each operating load. A detection switch 114 is operated by a paper detection roller, and inputs an operation signal to the CPU 111 to detect a jam. 11
6 is a 7-segment numerical display;
The LEDs are connected to the display decoder 117 to activate each digit. 117 is connected to the output ports O ₁₇ to O ₂₀ and selects one of the segments of the display 116 to light up in response to one of the scanning signals a to d. Signals a to d dynamically light up the display with pulses that repeat the output from a to d. Furthermore, display unit 1
16 is reset, etc. by output ports _O31 to _O33 . Reference numeral 118 is an automatic recovery circuit that monitors the operation of the CPU 111 and turns off the power to the CPU in the event of an abnormality and then automatically turns it on again. Reference numeral 119 is a display device for displaying warning marks such as weights on the operating section, and is activated by outputs from output ports _O24 to _O29 . 120 is a circuit for dimming and correcting the rise of the document lamp; 121 is a fixing heater operation and temperature control circuit; 122 and 123 are a cassette size detection circuit and its decoder; 124 is a size display; 125 is a fan and blower operating circuit. , 126 is a main motor operating circuit, 127 is a document lamp lighting circuit, 128
129 is a developing roller lifting/lowering circuit; 130 is a paper feeding and resisting circuit; 131 is a cassette stage selection circuit;
are forward and reverse operating circuits, 132 is a front and full exposure lamp lighting circuit, 133 is a high voltage AC circuit, 134,
135 is a group of input and output buffers. In this machine, the display 116 displays the number and size according to the key input, and the display is changed or maintained depending on the process.
9 to alarm the machine status and release or maintain it;
In addition, the on/off timing operations as shown in FIGS. 10 and 11 are executed using key input data and basic timing pulses, and 118, 120, 121
etc., to execute various safety controls and compensation controls,
The circuit configuration is not limited to this example, and there are various variations. When a well-known microcomputer is used as the central processing unit 111, its interior generally includes ROM,
Has RAM, INPUT, OUTPRT, and ADA.
ROM is a memory in which the contents of key input reading, display sequence, and process operation sequence are assembled and stored in advance in code.For example, the program shown in the flowchart in Figure 18, which shows an example of execution, is stored in a binary code microphone program. I remember it by method. RAM is a data memory that stores the program memory's own data and input data such as the number of copy settings, number of copies, cassette stage, etc.
is a port for inputting key signals and detection signals,
OUTPUT is an output port that latches the output signal,
ADA is a processing unit that has an accumulator function that temporarily stores data from input ports and data to output ports, and an ALU function that performs calculations and logical judgments on data from ROM, RAM, and input/output ports. Here, the input data is processed according to the execution of the ROM program and is processed according to specific steps.
The information is taken into the ACC, logically determined, and proceeds to the next step to control the copying operation load. 11-1 to 11-6 are respective AC load control circuit diagrams of FIG. 7. (Environmental Heater) Figure 11-1 shows the environmental unit circuit. This prevents the properties of the photosensitive drum and developer from changing depending on the environment such as temperature and humidity, which would adversely affect copy image quality. Sub switch SW1, door switch MS1,
2. When all circuit breakers CB2 are on and power switch SW2 is off (all off in the above figure), and when the temperature is below 18℃, drum heater H is turned on.
A full-wave rectified wave is supplied to 2, and the developer heater is turned on. When the temperature is 18° C. or higher, a half-wave rectified wave is supplied to the drum heater H2, and the developer heater H3 is turned off.
It is clear from the drawing that the thermoswitch TS turns on when the temperature is below 18°C and turns off when the temperature is above 18°C. In this example, the two heaters can be controlled to be energized in different modes using an extremely simple circuit. NE1 is a neo lamp that lights up when the main switch SW is turned on. (Motor, High Voltage Transformer) Figure 11-2 is a drive circuit diagram of the motor, transformer, etc. In the figure, 131 is a triax that energizes the motor;
Reference numeral 132 is a photocoupler for triggering the triax, and reference numeral 133 is a Zena diode for supplying a constant voltage to the photocoupler, which is used only when the load is the main motor. DC controller output (main motor is DRMD
When the signal) is 1, the LED inside the photocoupler 132
When a current flows through the LED and the LED emits light, the resistance of the CdS in the photocoupler decreases, and a current flows through the gate of the triac 131. This makes the triac conductive and AC loads such as motors and transformers operate. Output from control unit is 0
The opposite is true when , the load does not operate. In-machine cooling fan FM1, heater exhaust heat fan FM
2.Developer cooling fan FM3, pump motor M80
2. Pre-AC/pre-transfer/transfer high voltage transformer HVT1
is a similar circuit. In the present invention, even if the power switch is turned off during the rear rotation of the drum, the rotation does not stop; instead, the drum rotates a predetermined amount, stops, and then turns off the power. Connect to a power supply that does not turn off even when turned off (voltage is not stabilized). Other loads are connected to a regulated 24V power supply. Therefore, in the case of a main motor, a Zena diode is inserted. (Torque Motor) FIG. 11-3 is a circuit diagram of a torque motor that controls the elevation and descent of the developing roller. In the figure, 134 is a triax that rotates the torque motor 66 clockwise, 135 is a photocoupler that triggers the triax 134, and 136 is a triax that rotates the torque motor 66 clockwise.
137 is a photocoupler that triggers the triax 136,
RLUD is a control signal for raising and lowering the developing roller, and is output from the CPU 111. MS is a switch provided at that position that turns off when the developing roller has descended to a predetermined position. Explain the operation. When the drum starts rotating forward
CPU111 sets RLUD to 1, photocoupler 13
5 is turned on, the triax 134 is turned on, and the torque motor is rotated clockwise. Therefore, each developing roller is raised until it hits the drum surface. The switch MS contact changes to NC midway up. When the developing roller hits the drum with constant pressure, it stops, but the torque motor remains on. In other words, the torque motor slips while the developing roller is pressed against the drum with a constant pressure. Thereby, the above-mentioned development and squeezing effects are maintained well. When copying is completed and post-rotation begins, RLUD becomes 0.
Therefore, thyristor 135 is turned off and thyristor 137 is turned on instead. Therefore, the torque motor rotates counterclockwise to lower the developing roller. When the developing roller is lowered to the specified position, the switch is turned on.
MS3 is turned off as shown in the figure, and thyristor 137 and triax 136 are turned off. As a result, the torque motor stops rotating. Therefore, the developing roller remains stopped at that position due to its own weight. By the way, if you turn off the main switch SW2 as shown in the diagram, even when the developing roller is rising, the developing roller will turn off switch MS3 due to its own weight.
It descends to the position and stops. This prevents the roller from deforming due to the pressure of the developing roller on the drum when copying is interrupted and the drum is left unattended, and also prevents the roller from staining the drum surface. (Front, full-face exposure lamp) In Fig. 11-4, 138 and 140 are ballasts for lighting the full-face exposure lamp and the front exposure lamp;
139 is a relay that operates the ballast. When power switch SW2 is on and control signal DRMD for driving the main motor is 1, relay 139
turns on and its contact switches to the NO side, ballast 1
38, 140 to turn on each lamp. signal
When DRMD is 0, the above lamp is turned off. (Fusing Heater) Figure 11-5 is a lighting circuit diagram of the fixing heater, in which TH1 is the thermistor located on the back side of the hot plate 38 (opposite to the fixing surface), H1 is the nichrome heater, FS1 is the temperature fuse, 141 is heater H1
Triax for switching energization of 142
143 is a photocoupler composed of a photothyristor b, and the thyristor b turns on when it receives the light from the LEDa. 1
44 is a transistor whose collector is connected to the gate G of photothyristor b, 145 is a diode for level shifting, 146 is a diode for backflow prevention, and FSRD is a transistor whose collector is connected to the gate G of photothyristor b.
The signal from the temperature control circuit is 1 when the temperature is below 175°C and 0 when it is above 175°C.The LED is a light emitting diode that displays the signal status. 1 of FSRD when heater surface temperature is below 175℃
The LED is lit by the photocoupler 143.
Turn on LEDa. This generates a gate signal for thyristor b, but if transistor 144 is on, the gate of thyristor b drops to 0V, so the thyristor does not turn on. However, when the transistor is off, the gate is disconnected from the 0V line, i.e.
The thyristor turns on only at around 0V (depending on the threshold voltage of the transistor) in the AC sine wave. This makes it possible to minimize electrical noise when the power to the heater is turned on or off. By turning on the thyristor 143, the power supply AC→
R321→D307-A→Q311→D307-
A current flows through the route C→R322→FS1→H1→current AC, and since the triax 141 is turned on, the fixing heater H1 is also turned on. Further, when the heater temperature is 175° C. or higher, the signal FSRD becomes 0, and the heater H1 is also turned off, operating in the opposite manner to the above. Its operation diagram is shown in Fig. 17-1. The surface temperature of the fixing heater H1 is normally controlled by the thermistor TH1 and the DC controller to maintain it at 175°C, but during standby or when a jam occurs, the temperature of the surface temperature of the fixing heater H1 is controlled by the DC controller. The control temperature is switched to 140°C by relay K102 in Figure 12-1. Therefore, in that case, the FSDR becomes 0 when the temperature is 140 to 175°C. Note that when the main switch SW2 is turned off (see the figure), the power supply to the heater H1 is cut off. (Temperature control, protection circuit) Figure 12-1 shows the fixing heater temperature control and disconnection alarm circuit. In the figure, K102 is a relay for changing the set temperature of the heater, and VR101 is a relay for changing the set temperature of the heater to 175℃.
VR102 is a variable resistor for setting the temperature to 140°C, and forms a bridge with TH1, R112, and 113. Q103 is an operational amplifier that outputs a signal FSRD, Q104 is an operational amplifier that outputs an output when a disconnection of the thermistor TH1 is detected, and LEDs 103 and 104 are indicators that indicate when each FSRD is disconnected. When drum rotation signal DRMD is 1, relay K102
shows the state as shown in the figure, and the operation of the operational amplifier Q103 is turned on and off based on 175°C, and the heater H1 is turned on and off.
Adjust the temperature to maintain it at 175℃. TH1 signal DRMD
When the temperature becomes 0, the contact of relay K102 is switched and the set temperature is set to 140°C. operational amplifier Q10
Step 3: From then on, adjust the temperature to maintain it at 140°C. This characteristic diagram is shown in Fig. 17-2. Also, if thermistor TH1 is disconnected, R114,1
The balance of the bridge having 19 elements is lost, turning on the operational amplifier Q104, turning on the transistor Q105, and setting FSRD to 0. Therefore, heater H1
can be turned off to prevent overheating. (Original Lamp Lighting Circuit) FIG. 11-6 shows a lighting circuit for the original illumination lamp. In the figure, K301 is a relay in the normal state as shown in the figure, which turns off the power to the lamp LA1 in the event of an abnormality. The lamp is lit by activating the triac by the timing output IEXP signal from the DC controller. Please refer to the above time chart for the timing. This device adjusts the copy density by changing the amount of light emitted from the lamp LA. For this purpose, a dimming circuit is provided to change the phase of the amount of current applied to the triax according to the amount of displacement (VR 106) of the density lever 30, thereby changing the amount of light. As a safety measure, the document illumination lamp is controlled to be turned off in the following conditions. (1) If the document illumination lamp is on when the drum is not rotating. (2) If the optical system advance clutch does not operate properly after the document illumination lamp is turned on. (3) If the optical system advancement clutch continues to operate,
When the optical system does not reverse (detected by overrun micro switch MS4). (4) In the unlikely event that the above condition cannot be detected and the temperature near the document exposure lamp rises abnormally (detected by the temperature fuse FS2 which melts at 169℃). Relay K103 has lever resistance VR1 in the state shown in the figure.
06 to perform the dimming operation, and in the opposite state, turn lever 5.
It dims the light by the same amount as when it is set to .
A standard white plate was irradiated with 5 amounts of light according to the standard light amount signal SEXP, and its bright area potential (on the photoreceptor) was measured, and the value was determined accordingly. This determines the bias voltage of the developing roller. (Electrical Circuit) FIG. 14 shows the power supply circuit in FIG. 7. 15VAC outputs 15V AC which is only transformed by transformer T1. This power is converted to 10VDC in the DC controller and used to power the microcomputer, and is constantly supplied unless the sub-switch SW1 is turned off or the power plug P1 is unplugged. +24VDC is fully stabilized 24V DC after transformation and rectification, and the supply is cut off when power switch SW2 is turned off. +5VDC is a fully stabilized 5V DC after transformation and rectification, and since the Q704 input signal is received from +24VDC, the supply is cut off when power switch SW2 is turned off. U32V is a high-ripple 32V DC that is only transformed and rectified without passing through a stabilization circuit, so the supply will not be cut off just by turning off the power switch. UH24V is 24V DC that has been transformed and rectified through a simple stabilization circuit, and there is some ripple (voltage fluctuation of about +5%). + when power switch is turned off
Even if the 24VDC supply is cut off, if PHLD is 1, the supply continues, and the supply is cut off only when PHLD becomes 0. 13VAC is an AC 13V that is only transformed by transformer T2, and will not be turned off just by turning off the power switch. D701-704 are full wave rectifiers C701-70
3 is a smoothing capacitor, Q701-708 are elements constituting a well-known stabilization circuit, LEDs 701-70
3 is a light emitting diode that monitors the output state and PHLD. PHLD signal is drum drive signal DRMD
This is a signal that is generated in synchronization with , and when DRMD is 1, PHLD is also 1. This is because even if the power switch SW2 is turned off during post-rotation, the drum is rotated by the UH24V power supply until post-rotation is completely completed. (Self-diagnostic circuit) Figure 12-2 shows a diagnostic circuit that checks the operating status of the CPU. In the figure, Q133 is a timer that starts a timed operation with input 1 to port 2 and outputs level 1 from port 1 during that time period, Q130 is a transistor that is turned on by the timer output, Q131 is a transistor that turns off the +10V computer power supply, Q134 is +
This is a thyristor that shoots a 10V input line. Normally, since the pulse signal OSC is repeatedly output from the CPU, the transistor Q129 is turned on and the timer is not activated. When the pulse stops, Q129 turns off and starts timed operation, causing Q1
31 turns off the +10V line. When time is up after this turning off, Q131 is turned on again.
Thyristor Q134 turns on via Zena diode ZD109 to cut off the output when +10V becomes excessive. 12th for sequence and CPU self-diagnosis
This will be explained in detail with reference to Figure-2 and Figure 18-3. At the end of subroutine A, a step is provided to generate a self-diagnosis pulse. In the figure, the bypass flag is set and reset at the beginning of routine A. After being reset, this flag operates a bypass timer and is set after the timer time (abnormality detection), thereby outputting an abnormality detection signal from the output port O36. The bypass timer is a timer for a time corresponding to executing the branching step (discrimination routine) of the main flowchart having routine A more than the scheduled number of times. The switching flag is set and reset repeatedly every time routine A is executed, and is used to output pulses from the output port O36 in an oscillating manner.
Pulses from D15 are 1 and 0 once every 10 to 100 msec.
Invert. When passing through the discrimination routine in normal time, the bypass flag remains reset, so the oscillation pulse does not stop. When that time is exceeded, the pulse stops and timer Q133 of the circuit in Figure 12-2
to cut off the power line +10V. The normal passage of the routine is, for example, when the paper feed signal PF and the registration signal RG can be detected within a predetermined time after the optical system starts moving forward. In Fig. 12-2, Q129 turns off when the pulse oscillates from port 15, turns on when it stops, and outputs a negative trigger to timer Q133.Therefore, the timer is set for a time T determined by the time constants of R190 and C113 for ₁ minute from port 3 to 1. Output. Q131 is approximately the voltage rectified by full wave rectifier 126 and smoothed by C116.
16V is applied via breaker CB101.
The operation timing of the circuit is shown in Fig. 16-3. Q
The base of 131 is connected to the Zener diode ZD106 and has a voltage of about 10.5V. Therefore, Q131
outputs a stable DC voltage of +10V. Since Q130 is connected in parallel with ZD106, when 1 is output from the 3 terminals of Q133, Q130 turns on, Q131 turns off, and the +10V current becomes 0V (Figure 16-3). That is, when the oscillation output from the output terminal O36 of the microcomputer stops oscillating, the power to the microcomputer is turned off for the time _T1 , and the microcomputer is reset. Note that the microcomputer executes the program from the initial address when the power is turned on. This resets the RAM contents. Furthermore, even if the program sequence of the microcomputer CPU or the sequence of the copying machine itself is reset as described above due to destruction etc.
If no oscillation pulse is output from the oscillator, +10V will be turned on and off at approximately 2×T ₁ time intervals. Therefore
Various displays lit by the CPU repeatedly flash at the same cycle to notify the copier user of an abnormal condition. The microcomputer power supply circuit shown in the figure also has the following functions. First, when the voltage at the emitter of Q131, that is, the +10V output increases for some reason, the zener voltage of ZD109 exceeds about 11V, causing SCR and Q134 to become conductive, and D126
The direct current from the breaker CB101 increases through CB101 and R192, and the breaker CB101 is opened, thus performing a protection function against overvoltage application. Also, the rectified voltage from the bridge diode is C
When the power is turned on, C11 is smoothed by C116.
Since the voltage applied to Q131 has a slow rise,
The rise time of the emitter voltage (+10V) is usually slow, which can lead to malfunction of the microcomputer. In order to speed up this rise time, first, the voltage coming through R192 is applied to the base of the emitter-grounded NPN transistor Q132 through the Zener diode ZD107 and R187.
It is designed so that it will not turn on unless the voltage rises to 8V. When Q132 is off, the base of the transistor Q130 is connected to R185 and R1.
By connecting to R192 via 86, R
When a voltage of about 2V is applied through Q192, the Q131 turns on and Q131 turns off. This state continues until Q132 is turned on.Therefore, after the rectified voltage rises to about 8V, the +10V power supply rapidly rises to about 8V. In addition, in the present invention, it is also possible to turn on oscillation or set the level to 1 to trigger the timer Q133 in the event of an abnormality. (Input circuit) Figure 15-1 shows touch keys, input signals to CPU
This is a matrix circuit (multiplexer) for incorporating into In the figure, 0 to 9 are the contact points of the numerical keys, C, STOP,
I/R, COPY, UP, and LOW are the contacts of each clear key, stop key, interrupt key, copy key, cassette upper row designation key, and cassette lower row designation key, and close when the key is turned on. By grounding CP1 to CP4, the jam detection operation for delayed accumulation is disabled (CP1), the wait time is canceled (CP2), the drum rotation for measuring the surface potential is set to multiple times (CP3), and the multi-copy ( (infinite times)
(CP4) port. SC, SL, SR
is the signal from the micro switch that is activated when a cassette is inserted, PCEM is the out-of-paper detection signal for that cassette, PWSA, PWSB are the signals from each main switch, door switch turned on, TEMP, FLW,
KCT is the detection signal for each fixing temperature, no liquid, key counter off, EXP, JAM, TN is each document illumination lamp on, jam detection, toner low density detection signal, RG, PF, OHP is the register signal, paper feed signal,
This is the stop position signal of the optical system. ~corresponds to the blob output terminal from the probe decoder (Figure 7). I ₁ to _{I 4} correspond to the input ports of the CPU. 151 to 160 are AND gates. Several kilohertz oscillation signals are output from ~ of the DC controller without overlapping timing. For example, when 1 is output from I ₄ , 1
When is sent, it means that □3 on the numeric keypad was pressed. In this manner, the microcomputer reads, calculates, stores, and controls input signals. (Segment Display) Figures 13-1 and 13-2 are 7-segment LED displays that display the number of copy sets and the number of copies completed. LEDs 603, 604, 601, 6 in the diagram
02 is a 7-segment display for the second and first digits of the copy number, and the second and first digits of the set number, which has segments a to g as shown in Figure 13-2, and signals of ~. connected to the source. A to D are connected to a probe signal source that selects each digit. For example, in the case of the LED 602 (1's digit) that displays the number of sheets set, when 1 is output from a,
, , becomes 0, the 7-segment
LEDa, b, and c light up and display the number 7. From a to d, oscillation signals of several kilohertz are transmitted from a to d.
Output without overlapping pulse timing. From a to d, oscillation signals of several kilohertz are transmitted from a to d.
Output without overlapping pulse timing.
A ~ signal is output in synchronization with this. Therefore, each digit blinks for a very long time, so it appears to be constantly lit. This display performs display operations in response to numerical keys, start keys, interrupt keys, etc. For example, when copying 23 sheets, switch the power switch SW2.
When turned on, the set number display 20 and copy number display 22 will display 01 and 00 respectively, and key 2 and key 3 will be displayed.
By turning on sequentially, 02, 00 is displayed, and then 23, 00 is displayed. 23,00 with copy start key on
When one sheet is fed, 23, 01 is displayed.
Thereafter, 23 and n are displayed every n sheets fed, and when 23 sheets are fed, 23 and 23 are displayed. The copy operation is stopped when the copy key is not turned on again before the copy ends. Then display 01, 00. However, when the copy key is on, 23,00 is displayed at the moment it is on. If the interrupt key 23 is turned on at the 10th copy while copying, the display changes from 23, 10 to 01, 00.
When the number key 5 is turned on again, 05 and 00 are displayed, and the start key starts copying 5 sheets. When one sheet is fed, 05, 01 is displayed, when five sheets are fed, 05, 05 is displayed, and then 23, 10 is displayed again. After that, press the start key to display 23, 11...23, 23. Also, stop key 35 while interrupt copying of 5 sheets is in progress.
When turned on, the execution is interrupted, the numbers 23 and 10 before the interrupt are displayed on the display, and the remaining copies are executed when the start key is pressed after that. However, if you turn on the stop key twice, the next time the start key is 23,
Copy from 00. (Input operation) Turn on power switch 9. At this time, if the temperature of the fixing heater is below the specified value (175°C), the wait/copying display blinks. Raise the document table cover 5, place the document face down on the glass, and align it with the size index. Using the cassette selection keys 28 and 29, select the stand (upper or lower) containing the cassette to be used. When the original switch 9 is turned off and then turned on, the lower cassette table is automatically selected. It is convenient to place the cassettes you use most frequently on the lower shelf. Adjust the copy density lever according to the original (standard is 5, if you want to make it darker or lighter, set it to 9 or 1). Set the required number of copies (1 to 99 copies) using the numeric keypad 31, check it on the cassette number display 20, and turn on the start key. If you cannot set the number by pressing the numeric keypad, or if you set the wrong number of sheets, press the clear key and set again. 01,
Display 00. After copying starts, no changes can be made by pressing the clear key, numeric keypad, or upper/lower cassette selection keys from the time the original illumination lamp turns on until the optical system for final copying is reversed. If the paper out indicator in the cassette lights up during copying and the copying operation stops, set the copy paper, set the cassette in the main unit again, and then press the copy start key to automatically calculate the number of remaining sheets. Copied. If you want to stop copying during continuous copying,
When the copy stop key is pressed, the copy operation at that point is completed and then stopped. The number of copies displayed is
It then shows the number of copies and stops. Next, press the copy start key and the number of copies will be displayed as 00.
The set number of copies will be automatically copied starting from . If you press the numeric keypad to set the desired number of copies and then leave it for about 30 seconds, or copying ends (drum stops)
If you leave it for about 30 seconds after doing so, the set copy number display will be cleared to 01 and 00, respectively. In the case of interrupt copying, the operations and displays described above are performed. By interrupt copying, the current copy number, set number, and cassette stage are stored in the memory RAM in the CPU. While copying is interrupted, open the document table cover, replace the document, set the number of interrupt sets, and also select the cassette size (column) (display the selected column and the cassette size in that column). When a predetermined number of interruptions have been copied, the content displayed on the display is automatically changed to the content saved in the memory as described above. The cassette size indicator also displays the original tray size. If you want to stop the copying operation during continuous copying, press the copy stop key to stop the copying operation at that point and instantly display the set number of copies when the optical system is reversed or after it is reversed. ,
The size display and row display return to the display before the interrupt. It doesn't matter if you press the interrupt key during interrupt copying. After the set copy number display has returned, press the ●Interrupt key to perform interrupt copying again. ●Press the clear key to clear to 01 and 00. ●If you press the copy stop key, the set copy number display will not change, but if you press the copy start key, the copy number display will start from 00. (DC load) Figure 13-3 shows the paper feed drive circuit.
SL1 and SL2 are solenoids for lowering the paper feed rollers of each upper and lower cassette to feed paper;
UPUS and LPUS are signals in which the output to be lowered by the upper and lower paper feed rollers is 1, and as described above, they are output from the CPU in response to the paper feed timing detection signal PF and the cassette selection key signal. Note that if the total counter is off for some reason (signal is 0), no output is made. FIG. 13-4 is a drive circuit for the forward clutch of the optical system. In the figure, CL2 is an electromagnetic clutch, SCOV is a signal set to 1 by micro switch MS4 for detecting optical system overrun, and SCFW is a forward signal. When the optical system advance signal is generated (is 0) when is 1, electricity is applied and the optical system advance clutch CL2 is operated. However, if the optical system remains at 0 and the optical system does not invert at the predetermined position, MS4 will operate and become 0 (24V is cut off), so 0
Despite this, CL2 is turned off. The reverse clutch drive circuit is the same as the one that changed CL2 to CL3 and set it to +24V. The operating principle of resist clutches corresponds to the latter. Figure 15-2 is a basic clock generator, which generates the signal CL. When the power switch is on, +24V is supplied, so the LED is always lit. At this time, the phototransistor PTr is turned on, the transistor Tr is turned on, and the output OUTPUT becomes 0. Also, when the light shielding plate comes to the slit in the middle of the figure, the LED will light up.
Since the light is blocked, the output becomes 1. Output 1 and 0 are repeated by rotating the light shielding plate in synchronization with the rotation of the main motor (88 clocks/second). FIG. 15-3 shows a paper detector at the paper discharge section, which generates a signal JAMP. 153 is a light shielding arm, 15
4 is a light receiver having the same shape as in FIG. 15-2, and 155 is a piece of paper. When the paper hits the roller 36, the arm 153 is pushed in the direction of the arrow, and the light hits the light receiver 154, which outputs a signal 1. Figure 15-4 shows the cassette size detector, and the cassette base has an upper stage 155 and a lower stage 15 as shown in the figure below.
Four microswitches are installed in each of the 6 microswitches, which send signals for determining cassette size, etc. to the DC controller. Each switch was turned on (it shows 0, contrary to the diagram)
The resulting size will be as shown in FIG. In addition
MS902 and 906 are for checking the presence or absence of a cassette (1 in the figure). FIG. 12-3 is a diagram showing the relationship between the cassette and the display section. If you press the upper cassette selection key on the operation panel,
The CSS1 signal is output from the DC controller, and the LED
629 is turned on (upper row selection display), and when the lower row cassette selection key is pressed, LED 630 is turned on by CSS0 (lower row selection display). At this time, if no cassette is inserted, the micro switch on the cassette stand will not be activated, so if it is on the upper stage, MS901 1, MS903 1, MS
904 1, so from the DC controller
PCEL 1 signal is output and LED634 lights up (paper/
cassette supply display). MS902 does not operate when the cassette is not complete, so it lights up the same way. Also, when there is no paper in the specified cassette, CdS
PCEL becomes 1 from the circuit No. 58 and the LED 634 lights up. If a B4 cassette is inserted, MS9
Since 01 and MS903 are activated,
MS901 0, MS903 0, MS904 1
becomes. At this time, 1 is output to the B4 port of the DC controller, so LED607 and LED608
lights up. Figure 15-5 shows the power switch on signal PWSA,
This circuit inputs the door switch on signal PWSB to the CPU, and is connected to each +24V line and U32V line. This signal holds the display. Figure 18-1 is a schematic diagram showing the flow for performing the above control. When the sub switch and power switch are turned on, a timer for prewetting is executed, a switch for killing a jam etc. is read, and an entry flowchart for inputting numerical keys is shown. After that, it is determined whether the copy key is on, and the pre-rotation step and copy cycle step are executed. Figure 18-2 is a flowchart after the subswitch is turned on, and the CPU starts operating when the subswitch is turned on. When the sub switch is turned on, the computer CPU
starts programming the ROM. First, the CPU
Disables interrupt port input and internal timer interrupt execution, resets output ports and input ports, and clears RAM (1). and the output port,
Set the data to display 01 and 00 on the display (2), but since the display power supply of 24V is not turned on at this point, it will not be displayed. Next, input port I
4. Set I3 and input data PWSA, PWSB
and determines whether the main switch or door switch is turned on (3). Repeat the above operation when not on. When on, the timer flag and time flag are set, and the lower cassette flag is set and displayed (4). Turn on the developing motor, blower motor, and sensor motor, clear the register that stores the number of papers in the machine, and set the copy display flag.
Set the key acceptance flag (6). Next, the input port I2 is set and the signal CP2 is taken in to determine whether or not to kill the wait (7). If so, a flag for omitting rotation is set, and if not, a kill flag is reset, and it is determined whether or not the 5-hour timer puff 3 is 1 (8). If not, it is determined whether the 30 second timer flag is 1 or not, and if so, a timer set flag 2 is set for prewetting execution, a 4 second timer is set, and the timer operation for prewetting is executed. After 4 seconds, the number of clocks for the previous rotation, 170, is set in a predetermined area of the RAM (10). The main motor then turns on to rotate forward. Figure 18-3 is a subroutine for key entry and signal entry, which is provided in the routine to be executed at the judgment step in the main flowcharts of Figures 18-1 and 18-2.
The above-described process and display are controlled by detecting key-on and input signals as shown in FIG. 15-1. In the figure, sub EXC is an interrupt release routine, sub COPY is a copy key entry routine, and sub CP is a cassette key entry routine. In the sub-CP, the cassette stage reading routine is as shown in Figure 18-4. First of all, when the key enable flag is not 1, it means that there is no response even if the cassette selection key is pressed, when the main and door switches are off, when the jam occurs,
This is during copying, etc. At this time, the upper and lower cassette flags remain unchanged, and reading is performed only when the key enable flag is 1. This program routine is passed once every 10 to 100 msec, and each flag is set and stored almost instantaneously when the selection key is pressed. Then proceed to another reading routine. This flag is also changed by the program as follows even when the selection key is not pressed. First, when the main switch is turned off, the following happens. When either the door switch or the main switch is turned off, the program loop shown in the figure is rotated, and this loop continues until both the door switch and the main switch are turned on and forward rotation begins. In this loop, if the door switch is determined to be off even though the main switch is on, this embodiment considers the copy to be interrupted, so if the various resets shown in the figure are not performed, the cassette flag will also remain unchanged. . Conversely, when the main switch is off, the lower cassette flag is set and when the main switch is turned on again, the lower cassette is selected first. Reading and canceling the interrupt copy is performed in 18-6,
As shown in Figure 18-7. Here, the information on the conditions (number, cassette stages) for interrupt copying is held even when the door switch is turned off, making it convenient for the next operation. Even if it is an interrupt copy, pressing the stop key twice will completely cancel the number of copies. Furthermore, during interrupt copying, the cassette stage can also be evacuated or recalled from the display. In other words, when the power is turned off by opening the door switch, the interrupt state and interrupt display remain in memory without being cleared, and when the power is turned on again (door switch is turned on), the state before the door switch is opened is displayed, and when the copy key is turned on, the interrupted state is restored. It will be canceled. If the interrupt state is to be canceled manually, it will be canceled when the stop key is pressed according to the program shown in the figure. That is, in the flowchart of Figure 18-6,
If the interrupt flag is 1 (during interrupt copying), when the stop key is pressed, the interrupt flag display is reset, and at this time, the state of the number of copies before the interrupt is displayed, but whether or not to continue copying from that state is determined. ``Temporary stop flag 2'' is set to continue. Also, since this part of the routine is repeated at intervals of 10 to 100 msec, if the stop key is released once and then pressed again, the "temporary stop flag 2" will be reset and the continuous copy state will be released. That is, both interrupt copy cancellation and copy stop can be accomplished by pressing one stop button, and the distinction is made automatically. Next, when an interrupt occurs and when an interrupt is canceled, the program is as follows. That is, at the time of an interrupt and when the interrupt is canceled, whether or not the number of copies has been counted up, other conditions, and the selected cassette are temporarily stored in the evacuation memory from the memory section that serves as a copy execution status diagnosis for display. The data in the save memory section is transferred to the memory section for display judgment and is immediately replaced. Therefore, when the interrupt is canceled, the state before the interrupt is restored including the cassette stage. However, at the time of an interrupt, the cassette remains unchanged and copying starts from 0 unless the cassette is reselected by the next program (details are omitted). In the CPU 111, the input terminals I ₅ and I ₆ interrupt the program progress up to that point by input signals thereto.
A port for executing (interrupting) a specific program; the former is interrupted by the drum clock signal (CP), and the latter by the rise of the paper detection signal (JAMP). Cl is a pulse oscillator with a pulse width of 1 μsec for running the CPU 111, +10V is a port for applying the output voltage of the power supply shown in FIG. 12-3 to the CPU 111, and G is a port for grounding the CPU 111 to Gnd. A program according to the flowchart shown in FIG. 18 is stored in the ROM, and the flags shown in Table 1 are provided at each address in the RAM. This flag is set to 1 when set and set to 0 when reset, and program progress is controlled by determining its state.

【table】

【table】

[Table] Checking the reverse clutch will be explained with reference to Fig. 18-4. In the figure, SUB DETCT is a routine for this purpose, and when the optical system is not at the stop position after copy key-on detection and before exposure scanning (1), the reverse clutch is turned on (1 at port 06) (2), and then until the specified clutch count is reached. When the optical system reaches the stop position, the reverse clutch is turned off (3) and the process proceeds to the step of turning on the document lamp. However, once a predetermined count has been reached, it is assumed that the reverse clutch is damaged and the program proceeds to the jam routine, where relay K101 is turned on and the jam is set. Since the OHP position determination routine includes the routine shown in FIGS. 18-11, it is possible to generate a self-diagnosis pulse to check whether the position determination routine has been completed. The lamp check will be explained with reference to FIG. 18-7. In the figure, SUB EXP is a routine for checking abnormal lighting of the lamp, and is executed before exposure scanning.
Determine the start key (copy flag) (1), set the copy number display to 00 when it is on, and then determine whether the lamp is lit (3). The lighting signal LA1 from the lamp lighting detection circuit shown in Figure 11-6 is
The data is read into the CPU and checked using the timing signal via the matrix circuit shown in Figure 1. If it is lit (LA1 is 1), execute the jam alarm routine shown in Figure 18-10. When the lamp is not lit, level 1 is output from the output port to turn on the halogen lamp, and the forward clutch is turned on to start re-exposure (Figure 18-4). This lamp check routine is also provided in the routine shown in FIG. 18-6 that starts scanning after the completion of copying and in the middle of continuous copying of a set number. The jam detection operation will be explained. No. 18-17
In the figure, the paper is normally exited from the paper feed by the detection roller 3.
In order to count the number of drum pulses CL that is slightly larger than the number corresponding to the time required to reach 6, execute step (1) and subsequent steps. The delay jam flag and the above pulse number are set at the time of paper feeding (No. 18-5).
figure). From the set time, the number is decremented by 1 every time the pulse CL is generated (FIG. 15-2), and when it reaches 0, it is determined whether the jam has been killed or not, and the thread of the exit roller 36 is checked (3). When there is no paper, the process proceeds to the jam routine (Fig. 18-9) and becomes standby. If there is paper, the paper number counter in the machine is decremented by 1 and the process moves to the retention jam check routine. This is done by checking whether the paper passes through the roller 36 normally or not using a similar clock count. This time varies depending on the paper size, so
Set the clock number as shown in the figure (4), then -1 as described above (5) After counting the set number, check the paper again, and this time if there is paper, add 1 to the in-machine number counter. Proceed to jam routine. Performs counting operations for other purposes when there is no paper. The jam routine is shown in Figure 18-10, through which the standby 1 routine (Figure 18-8) is executed.
Proceed to Figure). First, set and reset each flag in the figure, make the wait up mark blink, and turn off the copy display (1). Then, reduce the number displayed on the copy number display by the number on the machine (2). Then, a jam signal is output from the execution report of the SUB OFF routine (Fig. 18-7) (3) such as turning off the halogen lamp. This turns on relay K101 (15-5
), display the jam mark 15 (4). This relay K101 remains on until the reset switch _SW3 is manually released. Also this relay K101
Output 1 is input to the input port of the CPU as JAMR. After counting 5 clock pulses CL, the main motor signal is set to 0, which is stopped and drum rotation is shifted to standby. The standby routine is shown in Figure 18-8,
Measure the idle time while the start key is not turned on. First, set TMSET flags 1, 2, and 3,
Distinguish weight killing and further set each display timer time and idle timer time to determine the shortest pre-rotation time (1). and the CPU for measuring this time
Starts the internal timer of (2). If the start key is turned on (3) before each timer counts up, the process moves to the pre-rotation step. However, if jammed (determine whether input port signal JAMR is 1 or not), key reading is prohibited (5), and the time measurement routine is executed at least until relay K101 is released.
Repeat SUBSET. SUBSET is a routine that measures 5 hours, 30 minutes, and 30 seconds using an idle timer and sets each flag. During these 30 seconds, set the specified output port to 0 and turn off the fan (floor) (6). If there is no jam, when the interrupt copying has finished (stopped) and there is paper, measure the display timer for 30 seconds (7), turn off the interrupt display, set the set number and copy number display to 01 and 00, and turn off the halogen Turn off the lamp and proceed to SUBSET. The door switch and main switch operation determination will be explained in detail. Conventionally, when the power is turned off, copying is immediately interrupted, but the only idea was to hold the power for a necessary period of time to delay the interruption. This device actively captures the operating status of each power switch as signals PWSA and PWSB, and changes control conditions and maintains memory according to the status of each switch. This is clearly shown in various parts of the flowchart in FIG. Figure 14, 15-5
This will be explained with reference to the figures. In Fig. 14, the input AC power is on the one hand the power supply voltage for the microcomputer (+
10V), and on the other hand the door switch MS ₁ ,
It is supplied to the power transformer T2 via _MS2 , and approximately +32V is output from the secondary side after being rectified and smoothed by D701 and C701. Furthermore, +32V goes through the main switch and the transistor Q703.
Stabilized to 24V. U32V and +24V each ZD1
11, ZD110, and is inputted to the base of each transistor Q135, Q136 via a dividing resistor. Therefore, depending on whether the door switch or the main switch is turned on or off, the collector outputs of Q135 and Q136 become as shown in FIG. 16-4. U32V, +
24V causes similar rise and fall times due to C701 when each switch is turned on and off. In this example, ZD1
10 and ZD111 are turned on by applying 4V and 22V, respectively, to make the responses of Q135 and Q136 different. T1, T2, and T3 are 100 msec. By the way, when the collector signals of Q135 and Q136 are OV, the door switch, the door switch, and the main switch are both treated as on, and when they are 1, the door switch is turned off, and at least one of the door switch and the main switch is treated as off, so the switch After detecting the state, the state of each switch is determined as shown in the flowchart. CB1-3, CB701-7 in Figure 14
03 is a breaker, and LF1 is a low-pass filter. The control when the main switch SW2 is turned off during the copy cycle will be explained with reference to FIG. 18-9. In this case, it completes rotation after a predetermined period of time and then stops, or it completes a jam check of the already fed paper and then stops. This allows the surface of the photoreceptor to be in the proper state for waiting, so the lifespan of the photoreceptor is not impaired, and the machine is not left with jammed paper left behind, so the machine can be restarted smoothly after it has stopped. be able to. If a power-off signal is detected by turning off the main switch or door switch during execution of the copy cycle (after turning on the copy start key and before completing the rear rotation) (Figures 18-15), the flag shown in the figure is reset (1). , check the on/off status of the door switch (2). In the case of a door switch, it is determined whether the current state is in backward rotation (3) and whether backward rotation has finished (4), and if the backward rotation is not started, the 190 clock is turned on. Set the rear rotation timer and rotate the rear rotation, and if it is before the end of the rotation, rotate the remaining rotation of the rear rotation and stop the rotation only after this is completed.
(5), Set the idle timer (6). If you have killed the weight, set it to 5 seconds, otherwise set it to 30 seconds. Then set the sheet count display to 01 (set) and 00 (completed).
, specify the lower cassette, cancel the interrupt copy, and wait. In the case of door switch off, the post-rotation is not executed, but the above-mentioned idle timer is set and the timer completion is checked (7), and the pre-rotation speed setting routine is exited to wait. Start by turning on the door switch and main switch (8) and move to the next standby (when jammed) or forward rotation (when not jammed) step (9). Here, since the clock pulse CL caused by the drum rotation is generated even during the post-rotation, an interrupt trigger is applied to port I5 even after the main switch is turned off during the copy cycle. Therefore, the clock count subroutine CNT of FIGS. 18-17 is executed and the delay hold check routine therein continues. In case of a jam, the jam routine shown in FIG. 18-10 is executed to latch the jam relay K101. Further, after the delay/retention jam flag becomes 1 (check start), the jam detection operation continues even if the main switch is turned off unless this flag is reset. By the way, this jam flag is held without being reset even when no clock pulse is input (such as when a door switch is turned off). Therefore, when the door switch is turned on from off and the drum starts rotating, the jam detection operation is performed again by the clock pulse, and it is determined whether or not the transfer paper remaining in the machine has been discharged (9). The operation of the lamp check will be explained with reference to FIG. 11-6. When IEXP is 0, +24V is grounded and the trigger signal to the triac transistor is turned off and the lamp is turned off.
Turn off LA1. Therefore, photocoupler Q
Turn off the power to 303, turn off Q302, and turn off Q30.
Turn on 0' to set the lighting signal EXP to 0. At this time, relay K301 does not operate. But the lamp
If LA1 remains lit, EXP is set to 1, Q301 is turned off, and 1 is output to 9 of Q305. On the other hand, when DRMD becomes 0 and the drum motor stops, 8 of Q305 becomes 1, and therefore 13 of Q305 becomes 0, charging C302. 2
After a second, Q306 is turned on and Q306 is turned off. Then, the 1 of the flip-flop Q305 is changed to 0, and 1 is output from 3. This turns on Q304, turns on relay K301, and turns off lamp LA1. In this way, when the drum is stopped, the lamp LA1
When the lamp is lit, the lamp line is forcibly cut. Also, since the optical system starts moving forward approximately one second after the lamp starts lighting, the lamp line is cut in the same way even if there is no forward signal after waiting two seconds. In other words, even when SCFW is 0, 8 of Q305 becomes 1, so the lamp lighting signal causes C30 to change as above.
2 and turn on relay K301 after 2 seconds.
If SCFW becomes 1 within 2 seconds, Q326 is turned on, C302 is discharged, and relay K301 is not activated. After the relay K301 is activated, the circuit can be reset by turning off the power switch SW2 (as shown in the figure). When the power is turned on again, Q305-5 becomes 0 until charging of C303 is completed, and the flip-flop is reset (Q305-3
is set to 0), Q304 and K301 are turned off, allowing the light to be lit again. Also, if the optical system continues to move forward and the optical system turns on the micro switch MS4 for overrun detection, MS4 operates contrary to the diagram and cuts off the power line of the lamp's dimmer circuit. At the same time, cut the power line for forward clutch CL2. (No. 13-4
figure). Note that it is preferable that the MS4 be attached to the end of the optical rail outside the overrun area. About 1 second after the lamp starts lighting up, this dimmer circuit
Triack regardless of phase by VR106
If a circuit is provided that turns on the Tr for the full wave and then returns to the phase set by VR106, the lamp LA
It is possible to improve the rise in illuminance of 1. Furthermore, when MS4 is turned on, the level 1 signal stabilized at 154 in Figure 15-5 is output to gate 15.
5, the driver 156 is turned on, thereby activating the relay K101 and lighting the jam indicator 15. Then, when main switch SW2 is turned off and reset switch SW3 is turned on by hand, relay K1 is activated.
01 is reset. Therefore, when SW2 is turned on again, the reverse clutch is turned on until the optical system reaches the stop position (OHP signal), so the optical system can be returned to its original position. Detection control related to developer will be explained. A magnet is provided on a float floating in the liquid in the developer container, and a reed switch MS802 is provided on the container side that responds when the liquid decreases below the current amount and the float goes down. When the magnet moves away from the reed switch, it outputs a liquid-free signal LEP to the input port. As a result, the replenisher indicator on the panel section lights up and stops the start of the next copy after repeated copying. They are provided to detect the concentration of the liquid flowing between the CdS submerged in the developer container liquid and the lamp, and the replenishment timing TSE is determined when the amount of received light is above a first predetermined level.
(Figure 9-2), replenish the toner liquid and turn on the check LED installed inside the machine. When the amount of light received is less than the second level, it is assumed that the replenishment toner liquid is empty, and the toner replenishment indicator on the panel is turned on, and the check LED provided inside the machine is turned on. The lighting of CdS is controlled in synchronization with the DVLD signal of the developer motor. The bias voltage for the developing roller (metal 102) is changed in three ways. When the drum is not rotating, connect it to ground (GND) to prevent toner from adhering to the developing roller. This is effective because it corresponds to when the roller is lowered. When the drum is rotating but there is no developing operation, apply -75V to prevent the first image from being too dark. During developing operation (Figure 9-2)
DVLB) applies +50V to the drum surface potential to prevent fogging. The BVLB operation timing changes the number of count clocks according to the copy size and always corresponds to the developing operation. This surface potential is detected during pre-rotation as described above. V _L1 , V _D , and V _L2 in FIG. 9 are surface potential measurement timing signals, which are output from the output port _O10 .
The sensor motor in the potential measuring device rotates during the pre-rotation to step the detected potential. V _L1 and V _D measure the drum surface potential formed by turning standard blank lamps on and off (other blank lamps are lit). V _L2 automatically sets the exposure lamp LA1, which lights up when the copy key is turned on, to a brightness of 5 (SEXP signal) and creates a standard white pattern of 25.
(FIG. 3) was exposed to light and the formed drum surface potential was measured. Thereafter, the brightness is automatically returned to the level set by the lever 30 (FIG. 30), and document scanning is started. The bright potential and dark potential due to V _L1 and V _D are compared with their respective predetermined values, and the difference is multiplied by a coefficient determined by the characteristics of the photoreceptor, etc., to generate signals Vp and VAC (the third Figure 11-7) is output. In Figure 11-7, Tc ₁ is the primary charger 51
ACS is a DC-DC inverter that applies high DC voltage to
DC-AC that applies high voltage AC to the secondary charger 69
The inverter, Tc ₂ , converts DC to the current of this charger 69.
The DC-DC inverter REC is a circuit that detects the DC component of the corona current, and AMP1 and AMP2 are the circuits that detect the DC component of the corona current. This is an amplifier that is controlled by the outputs of TC1 and TC2. When HVDC occurs, the corona charger 51 is discharged by the output voltage of TC1, which is determined according to the control signal Vp that sets the primary corona to a predetermined value. or
After the HVAC is generated, the corona charger 69 is discharged by the output voltage of the inverter ACS superimposed with the output of the TC2, which is determined according to the control signal VAC that makes the DC component of the secondary corona predetermined. Also, the corona current detected by the resistor _R12 in TC2 is converted to DC by the difference device REC.
It is fed back to AMP ₂ via Q ₇ so that only the component is controlled and compared with a predetermined value so that it remains constant. Similarly, the current in the primary corona is detected by the resistor R ₁₁ in TC1, and the current in TC is kept constant through _Q5 .
1 is feedback controlled. That is, both the surface potential and the discharge current are controlled at a constant level. Note that the ISP signal in FIG. 9-1 sets VP and VAC in order to initially discharge the primary and secondary chargers with each constant voltage before detecting the potential. The reason why the surface potential is repeatedly detected and controlled by performing pre-rotation several times is to bring the surface potential closer to a desired surface potential. In this example, the pre-wet and pre-rotation times are controlled according to the standby time or SW ₂ off time, but when sub switch SW ₁ is turned off due to mechanical adjustment, etc., the self-diagnosis function mentioned above is activated and the 10V power supply to the CPU is repeatedly turned off. If so, execute a constant prewet and multiple rotations before entering the copy cycle. That is, in FIG. 18-2, the sub-switch SW ₁ ,
When the 10 or 15V power is turned on from off, the program will always proceed from power on, so set the installation timer flags 1, 2, and 3 (3'). Setting all these flags is the same as leaving it alone for more than 5 hours. Therefore, in step (8), which determines whether the standing time is 5 hours or more, prewetting is set and executed, and in step (11), the maximum number of revolutions is set to 4 (12), and its execution is executed (2-0). In addition, when proceeding from standby to forward rotation, steps (8) and (11) are reached via step 5, but it is determined that it has been left unused for more than 30 minutes (step 13).
to set forward rotations 1 and 2, and execute the corresponding forward rotations. Also, if it has been left unused for more than 30 minutes, the ISP flag (set before starting copying) is checked, and if the timer is running continuously (copying for a long time), rotation 2 is set. If it is not uploaded, operate (15), perform the preparation rotation, and proceed to the copy cycle. The flowchart shown in FIG. 18 will be explained below. In Figure 18-3, ISP on is port (13)
Set O ₃ and output the initial potential from high voltage DC or AC. Note that in FIG. 18, on/off means outputting 1 and 0 from the corresponding output port, so the port names are omitted. The main motor is turned on and the forward rotation shown in FIG. 1 is executed (1), and its completion is checked by checking whether the clock (using a sequence counter described later) has counted up. During this rotation, the optical system is returned to the stop position (11). Further, the drum surface potential is detected and controlled by the subsequent rotation. First, the bright area potential is measured using a standard blank lamp and high voltage control is performed (2). After that, if the kill signal CP ₃ of the input port is on, the rotation continues and the bright area detection control is repeated (12).
If not, turn off that blank lamp.
(3) When the turned-off drum surface reaches the sensor position, (4) the bright area potential is measured and controlled. Incidentally, potential control is performed by an external circuit shown in FIG. 11-7. Repeat the previous rotation in this way and check if you have reached the preset number of times.
(7) When reached, set the ISP flag and continuous timer, and set the idle timer (8). At (9), the copy flag (set by the copy key entry) is checked, key entry is prohibited (10), and the process proceeds to the copy preparation cycle. After passing the copy key waiting period, the process advances to post-rotation mode. In Figure 18-4, first perform the position check DETCT of the optical system as described above, turn on the original lamp, set SEXP to 1 for standard exposure (4), and detect the potential of the exposed surface (5). Determine the bias potential. After this second controlled rotation, the forward clutch is turned on to move the optical system forward (6). The paper feed signal PF is checked in the middle of forward movement (7), and if it is not checked even after a long time, it is treated as a jam. Then, turn on the paper feed solenoid (8) and lower the paper feed roller to feed paper. At this time, the in-machine copy number counter (register) and the copy number counter are incremented by 1, and the contents of the latter are displayed on the copy number display 22 (SVBDISP). In Figure 18-5, in (1) the input port
Check CP ₄ on. By turning on CP ₄ , copies are made repeatedly regardless of the number of copy sets. Note that turning on CPs _{1 to 4} means turning on a switch to input level 1. When CP ₄ is on, or when the set number and copy count number are not equal, count 24 CL and apply the previously determined developing bias voltage to the developing roller (2). At the same time, it activates the ATR counter (described later) that determines the timing of liquid replenishment. Then register signal
Check RG and turn on the resist clutch. Here too, if RG cannot be checked for a long time, treat it as a jam. By the way, if CP ₄ is off, when the number of copy counters is the same as the set number, and there is no interrupt copy instruction, the copy flag is reset, and if there is an instruction, the interrupt flag is also reset to prepare for post-rotation. Then run the bias and resist. After turning on the registration roller, set the number of clocks for delay jam check (8), and input the signal from the cassette switch to the input port (9). Then, determine the size and set the reversal timing of the optical system in three ways.
(Ten). The size is determined by reading the 1 and 0 states in FIG. After counting the number of pulses CL corresponding to that period, the document lamp and forward clutch are turned off to complete the exposure scan, and the reverse clutch is turned on (11). After that, count 42 clocks and switch the bias to -. The pulse count in Fig. 18 is 18-1.
This is done using the SVB CNT interrupt program shown in Figure 7. In Figure 18-6, check the copy flag that is reset by the stop key etc. (1), turn off the copy display 23 at stop (2), and
Leave 0 and 22 as they are to enable key entry. Even if it is not a stop, the copy number display 22 is displayed by the previous count-up flag check.
00 and check the fake paper feed signal PF' (3). The long-term check is also performed. Thereafter, the copy flag is checked, and the original lamp is turned on and checked (4) again. Furthermore, check the stop position of the optical system and check it for a long time.
(5) Check the toner (when the liquid concentration is below the second level) and (6) turn on the display 18. Then perform a post-rotation. However, if the number of copies is not counted up and the copy flag is not 1, check the position of the optical system with key input prohibited (5)
Then, as shown in Figure 18-4, the optical system is moved forward again and copies are made repeatedly. In Fig. 18-7, when entering the rear rotation, the copy flag is checked again (1), when the copy key is on, the stop key is pressed twice at the time of interrupt, and when the copy number is counted up, the copy number display is set to 00 (2), Check whether the lamp is overlit, turn on the lamp, and start exposure again. However, when the copy key does not turn on, the high-voltage DC etc. are turned off, the developing roller is lowered, and a subsequent rotation of 190 clocks is executed from there.
After that, the copy flag is checked, and if the copy key has been turned on by then, the copy number display is cleared, the previous rotation is executed, and the copy is started. However, if the copy key is still not turned on, 0 is output to a predetermined output port to turn off loads such as the original lamp (6). Since the energization level of the fixing heater is changed here, there is a possibility that the wait-up flag will be reset, so this flag is checked and the copy display is flickered when the flag is reset. Then, turn off the main motor and go to standby. In FIG. 18-8, the determination of C after waiting is performed by checking the flag set by the input of CP ₂ at the input port. This shortens the time of the installation measurement timer. When the copy is not started and there is no jam (3) When the internal timer enters standby and counts 30 seconds, the number displays 20 and 22 are set to 01 and 00, and the interrupt flag is set.
Turn off the interrupt indicator (7). However, if the stop key or interrupt key is turned on and there is no paper or liquid, the above display control will not be performed. Then, if TM flag 1 is not set, that flag is set, and the remaining time until 30 minutes is set to 29 minutes and 30 seconds.Then, the idle timer is counted and checked repeatedly (8) After the set time, TM flags 2 and 3 are set.
Set. Also, even if you leave it for 30 seconds after making a numerical key entry, the above display clearing and other controls will be performed. The power-off routine and jam processing routine shown in FIGS. 18-9 and 18-10 have been described above.
Note that the load is turned off at the same time as step (1) in Fig. 18-9. Subroutine A in Figure 18-11 is a routine SUBEXC for exchanging data related to interrupts, and a routine for determining copy conditions related to the start key.
SUBCOPY, operation key input reading routine
SUBKEY, paper cassette check routine
This is a step for sequentially executing SUBPC, and is also a step for outputting a self-judgment pulse. A quaternary counter is provided internally, and each time routine A is executed, it is incremented by 1, and each subroutine is executed sequentially, and after the fourth time, it is repeated from the beginning. In FIG. 18-12, it is checked whether key entry is possible (1), and the interrupt flag and 1 o'clock stop flag 2 are determined (2) and (8). The key enable flag is 1 except during copying, jamming, etc. When it is neither an interrupt copy nor an interrupt cancellation, the lower cassette flag is determined, the cassette stage is displayed, the signal CSS is set to 0 (3), and the number display routine is executed.
Run SUBDISP. During interrupt copying, set number memory contents and copy number counter contents are
When evacuating to a different location in BAM and canceling the interrupt,
Or reverse it (5). Then select the cassette
(3) Set the interrupt time displays 20 and 22 to 01 and 00. The numeric display routine executes switching of lighting digits to provide a so-called dynamic display. Indicators 20 and 2 are output from the output port in synchronization with the switching.
Output each digit data of 2 in order (7). In FIGS. 18-13, it is checked whether the key entry is possible (1), and the input of the cassette key is determined (1). Then, the display and flags related to the cassette keys are controlled (2). Input the signal for no paper and no cassette (3),
Setting the predetermined flag and lighting the display 16
(Four). Also read the switch signal from the cassette and
Set the street size flag(5). At SUBKEY in Fig. 18-14, check whether key input is possible or not, and check whether clear key is on (1). Set the display to 01, 00 using the clear key. If it is not a clear key, first press probe port 1 No. 15-
Set figure 1 and read number keys 0 to 3, then set port 2 and read numbers 4 to 7, set port 3 and read numbers 8 and 9 (3). The signals from the input ports _I1 to _I4 are input in 4 bits at a time and each bit is determined to be 1 or 0, and the following determinations (checks) are made. It does not read even if the key is turned on three or more times (2). If the data from the first key-on is not 0, it is displayed in the first digit of the set display 20. The data from the second key-on is transferred to the register and display corresponding to the second digit, and then stored and displayed in the empty space. At SUBCOPY in Figures 18-15, when both the door switch and the main switch are on (1), the copy key is turned on (2). Under the condition that there is no input signal such as interrupt key, stop key, no liquid, jam, etc., a copy flag is set by the copy key and a copy display is performed (Figures 18-16). However, when the interrupt key is on, the interrupt indicator 21
and set the flag (4). When the stop key is on during normal copying, the operation due to key chattering is avoided (6) and the copy flag is reset. The stop key during interrupt copying has been described above. Also, the stop key that kills the weight, the key counter is missing (10), paper, cassette, no liquid,
In the case of a jam, the copy flag is reset in the same way. The liquid timer operates as a counter using SUBTMR. SUBCNT in Figures 18-17 is pulsed to execute a program interrupt by input on port _Q5 .
At the rising edge of CL, the registers in the CPU are saved to an empty space in RAM (7), and the timing for operating loads such as lamps is determined. The sequence flag is set at each step at the start of counting. This flag is determined and the counter set several times in that step is decremented by 1 for each CL (8), the bias counter (9) determines the timing of bias voltage application, and the counter (9) determines the replenishment timing at low concentration. 10) is decremented by 1, and at each count-up, 1 and 0 are output from a predetermined output port of the CPU to make it inactive. The jam counter has been described above. SUBTMR in FIGS. 18-19 is an internal timer routine that operates as a timer by counting pulses that cause the computer to run. This is done using a program interrupt method, so save the data (1), set the interval for blinking the display 25 during wait, and execute (2).
30-second operation for automatic reset of the seconds display (3), operation of the idle timer (4), continuous timer operation (several 10 minutes) (5), and operation of the liquid timer (6) to output a delayed signal when there is no liquid. . In the following subroutine, RETURN is routine A.
Indicates a return to the determination routine in the main flow that executed. The ISP flag shown in Figure 18-2 also contributes to setting the rotation speed when the main switch and door switch are turned off and then turned on. Also, in Figure 18-7
SUBCLR1 sets the number display to 0 when the stop key is pressed twice during an interrupt and when the copy number is counted up.
In FIG. 18-9, (9) is for setting the holding time after setting the number, and checking and clearing the display (display memory clearing) is performed in (7). Also, to shorten the time of the idle timer, the set time in (10) and (11) is corrected to 5 seconds in (12), and the TM flag is set when the 5 seconds set in (1) elapses and this time further elapses. Set 1, 2, and 3. To summarize the features related to the number display, etc., when the door switch is turned off, the drum stops immediately, but the RAM retains the display, and if you turn it on and leave it for 30 seconds, the display clears (auto clear). When the main switch is turned off, the drum stops after rotation, but part of the RAM and display are immediately cleared.What is not cleared is the memory and registers related to the idle timer, clock counter, and jam counter. When a jam occurs, the display is corrected and the display is held; when the stop key is turned on, the display that was before the normal turn on is held and auto-cleared; when the copy count is up, the display 22 is auto-cleared to 0 and 20; when there is no liquid, etc., the display is held at that time, and the interrupt key Now clear the display. In each of the above modes during an interrupt, the above applies except for the stop key.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a copying machine according to the present invention, and FIG.
The figures are a plan view of the operation section of the copying machine shown in Fig. 1, Fig. 3 is a sectional view of the copying machine shown in Fig. 1, Figs. 4-1 and 4-2 are a plan view and a sectional view of the exposure section, and Figure 5-1, 5-
Figure 2 is a sectional view of the developing device, Figures 5-3 is a perspective view of the developing roller, Figure 6 is a block diagram of the drive system, Figure 7 is a block diagram of the electrical control system, Figures 8-1 and 8. −
Figure 2 is the process mode time chart, No. 9
Figures 1 and 9-2 are chart diagrams showing the operation timing of each part of the copying machine, Figure 10 is a circuit block diagram of the DC control section in Figure 7, and Figures 11-1 to 11-
Figure 7 is the circuit diagram of the AC load section in Figure 7.
Figures 2-1 to 12-3 are the DC control circuit diagrams in Figure 10, and Figures 13-1 to 13-4 are the DC control circuit diagrams in Figure 7.
DC load circuit diagram, Figure 14 is the power supply circuit diagram, 1st
Figures 5-1 to 15-6 are circuit diagrams of the input section in Figure 7, Figures 16-1, 16-2, and 16-3.
Figures 16-4 and 11-5 and 12-1 respectively
12-2 and 15-5,
Figure 17 is a combination table of cassette switches.
Figures 8-1 to 18-19 are flowcharts, and in Figures 2 and 3, 28 and 29 are cassette selection keys, 30 is a copy density setting lever, and 31 is a number key for setting the number of copies. , 33 is an interrupt copy key, 34 is a copy start key, 35 is a stop key, 56 is a fan motor, 66 is a torque motor, 71 is a main motor, and 67 is a surface electrometer with a built-in sensor motor.

Claims (1)

[Scope of Claims] 1. A means for forming a latent image on a rotating body, a means for developing the latent image, and a means for rotating to clean the surface of the rotating body before starting to form a latent image on the rotating body. An image forming apparatus characterized in that the rotational cleaning time by the rotating means is controlled in accordance with the time during which the apparatus is left after forming a latent image, and when the apparatus is in a specific state, the rotational cleaning is performed for a specific time regardless of the time when the apparatus is left unused. . 2. The image forming apparatus according to claim 1, wherein the specific state of the apparatus is a state in which power to a control circuit for controlling image formation is cut off.