JPS6210672A - Electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To prevent unnecessary toner consumption and reducing the burden of cleaning to avoid photographic fog thereafter by detecting misflashing to control a destaticizing means and destaticizing the part where an electrostatic latent image is formed if a photosensitive body is normal. CONSTITUTION:If a flash signal is in the low level at the fall time of a flash trigger signal, it means that a flash lamp 5 is not lit by some abnormality, and a destaticizing lamp 16 is lit for a prescribed time then. When a belt-shaped photosensitive body 7 is normal, the part where the electrostatic latent image is formed is destaticized, and the cycle of a machine is shortened, and an indicator lamp 19 of a console panel is lit to display the occurrence of misflashing. This work is performed if the flash lamp 5 is not lit. Thus, the occurrence of black copies is eliminated to prevent unnecessary toner consumption and the burden of a cleaning device is reduced not to cause photographic fog thereafter.

Description

[Detailed Description of the Invention] The present invention detects so-called mis-flash in which the flash lamp does not turn on even though a lighting instruction is given in a full-exposure type electrophotographic copying machine, and its subsequent detection. This is related to the processing of

[U.S.I. The second example is a general example of a full-exposure type electrophotographic copying machine.
As shown in the figure.

Reference numeral 1 denotes a copying machine casing, and a platen glass 2 serving as a document mounting table is stretched on the top surface of the casing 1, and a platen cover 3 is freely supported by 17f1m on top of the platen glass 2.

The interior of the copying machine is divided into two regions, upper and lower, by a bowl-shaped reflective member 4 with a reflective inner surface.The upper region is a space for fixed lighting with a flash lamp 5 inside, and the lower region is The area is equipped with various devices including a photoreceptor.

A lens 6 is attached to the center of the reflecting member 4, and below the lens 6, a belt-shaped photoreceptor 7 is suspended over a roll 8 so as to be movable counterclockwise.

Around the belt-shaped photoreceptor 7 are charged corotrons 9. Developing device 10. Transfer Corotron 11°Crim
: A swing device 12 and the like are arranged.

To explain the procedure of the copying operation based on the above configuration, the original 13 is placed at a predetermined position on the platen glass 2,
The platen cover 3 is closed to fix the original 13, prevent light leakage, and cause the flash lamp 5 to emit light.

The light from the flash lamp 5 is reflected by the reflecting member 4 and indirectly illuminates the surface of the original W&13 through the platen glass 2. The reflected light passes through the lens 6 and reaches the photoreceptor 7, and the surface of the photoreceptor At the periphery of the belt-like photoreceptor 7 where an electrostatic latent image is formed, a charge corotron 9 is first applied.
The surface of the photoreceptor is uniformly charged, and then an electrostatic latent image is formed by the exposure, toner is attached to the electrostatic latent image by a developing device 10, and the toner image is transferred to a sheet of paper by a transfer roller 11. The toner remaining on the surface of the photoreceptor is removed by a cleaning device 12, thereby completing the series of steps.

A series of copying steps is performed by timing-controlling the driving of each device by a control system.

(1) In this way, the drive of each device is integrated into a series of copying processes, and if there is any problem, perfect copying will not be possible.

If the flash lamp 5 does not emit light for some reason despite the control system instructing the flash lamp 5 to emit light at a predetermined evening time, the light-sensitive image that should originally form an electrostatic latent image will be removed. The surface part of the body is not fully irradiated with light and enters the developing area while the charges charged by the charge rollers 1 to 9 are retained as they are.

Therefore, the toner adheres to the entire surface of the photoreceptor by the developing device 10, and the toner is wasted.

In addition, the amount of toner remaining on the surface of the photoconductor after transfer is larger than usual, which places a heavy burden on the cleaning device 12, and if the capacity of the cleaning device 12 is exceeded, the toner may not be completely removed before the next step. This cycle will occur, causing image fog etc. in later copied images.

Furthermore, images caused by mis-flash will become black copies, and when using a sorter, etc.,
Later, it was necessary to make another copy and replace it with the copy paper, which was time-consuming.

The present invention has been made in view of the above, and an object of the present invention is to prevent the occurrence of black copies by removing static electricity from the relevant portion of the photoreceptor surface even if a misflash occurs.
It is possible to avoid wasteful consumption of -] -, reduce the burden on the cleaning device, etc., and furthermore, it is possible to indicate the occurrence of a mis-flash. The point is that it provides an electrophotographic copying machine.

.゛゛ruta　 The configuration of the present invention will be explained based on FIG.

In a full exposure type electrophotographic copying machine, A is a flash lamp for exposure.

B is an exposure control means for controlling the lighting of the flash lamp A.

C is a light detection means for detecting the light from the flash lamp A.

D is a mis-flash detection means, which inputs a flash lamp lighting instruction signal from the exposure control means B and a detection signal from the light detection means C, and detects a case where the flash lamp does not turn on despite a lighting instruction. It is something to detect.

Reference numeral E denotes a control means for inputting signals from the miss-flash detection means and controlling the driving of various internal devices.

Reference numeral F denotes a static eliminating means for eliminating static electricity from the surface of the photosensitive material under the control of the control means E.

G is a display means for displaying a mis-flash under the control of the control means E.

The present invention is configured as described above, and when a misflash is detected by the misflash detection means, a detection signal is output to the control means E, and the control means E drives the static elimination means F to eliminate static electricity. , can be displayed by display means G.

Further, the control means E can stop the operation of the entire copying machine after the static electricity is removed.

EMBODIMENT OF THE INVENTION Hereinafter, embodiments according to the present invention illustrated in FIG. 3 and subsequent figures will be described.

FIG. 3 is a simple explanatory diagram of the interior and control system of the copying machine of this embodiment, and the internal structure of the copying machine is substantially the same as the example shown in FIG. 2 above.

A light m-sensor 15 is provided in the upper indirect lighting area inside the copying machine casing 1.
Furthermore, a divided static elimination lamp 16 is provided at the periphery of the belt-shaped photoreceptor 7 adjacent to the exposure area.

The light amount sensor 15 outputs a signal indicating the light M value in the indirect lighting space to the flash lamp power supply 18, and
A light detection signal is output to CPU 17.

In addition, the divided static elimination lamp 16 has a plurality of lamps arranged in parallel oriented in the width direction of the belt-shaped photoconductor 7, and is capable of divided lighting. It is used to eliminate excess charges on both sides of the direction.

The flash lamp power supply 18 is feedback-controlled based on the signal from the light amount sensor 15 in order to match the light amount of the flash lamp 5 with the reference value of the light amount outputted from the CPU 17.

Further, the CPU 17 detects a mis-flash based on the signal 'instructing the lighting of the flash lamp 5' and the light detection signal from the light amount sensor 15, and turns on the divided static elimination lamp 16.
This gives instructions to turn on the light.

A schematic block diagram of the control system in this embodiment is shown in FIG. 4 and will be described in detail.

The light sensor 15 includes a light sensor 20 that detects the light inside the copying machine and converts it into an electrical signal, an integrating circuit 21 that integrates the electrical signal and determines the light value, a comparison circuit 22 that compares the light amount value with a reference value, It is comprised of a timer circuit 23 which operates at the rising edge of the photodetection signal and forms a high level signal (flash signal) for a certain period of time.

The flash lamp power supply 18 is an AC power supply 25. The flash lamp control circuit 26 includes a flash lamp control circuit 26 that controls the amount of light emitted from the flash lamp 5, and a trigger power source 27 that turns on the flash lamp 5.

The CPU 17 is a timer circuit 23 for the light amount sensor 15.
A flash signal is inputted from the flash lamp power source 18, and a light m command signal, which is a reference value for the light emission of the flash lamp 5, and a flash trigger signal for causing the flash lamp 5 to emit light at a predetermined timing are sent to the Franc 21521111111 circuit 26 of the flash lamp power supply 18. At the same time, the IIJm signal is output to the divided static elimination lamp 160 indicator lamp 19 and other units.

The display lamp 19 is arranged on the console panel on the front of the copying machine, and is used to display information to the operator.

The details of the flash lamp control circuit 26 will be explained based on FIG.
1 is connected to a rectifier circuit 32, and the rectifier circuit 32 is connected to a resistor 33.
．． 34. Diode 35. A smoothing circuit consisting of a capacitor 36 and a coil 37 and a bypass resistor 38. It is connected to both poles of the flash lamp 5 via a thyristor 39.

The connection point between the resistors 33 and 34 is connected to one input terminal of a comparator 40, and the output terminal of the comparator 40 is connected to the relay switch 30.
The light amount command No. 13 from the CP LJ 17 is input to the other input terminal of the comparator 40.

Further, the gate terminal of the thyristor 39 is connected to the output terminal of the comparator 41, and one of the input terminals of the comparator 41 is connected to the CP
The light m command signal from LJ 17 is input, and the other input terminal is connected to the integration circuit 2 of the light sensor 15.
The optical m monitor signal which is the output signal from 1 is input.

Note that the flash lamp 5 causes discharge and emits light by applying a pulse voltage from the trigger power source 27, and the pulse voltage of the trigger power source 27 is outputted after a flash trigger signal is input from the CPU 17.

In the flash lamp control circuit 26, the AC power supply 2
The alternating current voltage from the flash lamp 5 is boosted by a booster circuit 31, rectified by a rectifier circuit 32, smoothed by a smoothing circuit, and applied to both poles of the flash lamp 5 as a direct current voltage.

At that time, the voltage charged in the capacitor 36 is detected by the comparator 4.
0 is compared with a reference value of the light δ command signal, and a predetermined voltage is applied to the flash lamp 5 by controlling the relay switch 30.

The amount of light emitted from the flash lamp 5 is determined by the light amount sensor 15.
The light amount value and the reference value of the light amount command signal are compared by the comparator 41, and the applied voltage is bypass-controlled by controlling the thyristor 39.
152,150 luminescence is set to a predetermined value.

In this way, the amount of light emitted by the flash lamp 5 is always adjusted to the reference value of the light amount command signal output from CPU.

When the flash trigger signal from the CPU 17 is output, a pulse voltage is applied from the trigger power supply 27 to the flash lamp 5, the flash lamp 5 emits light, the light emission is detected by the optical sensor 20, and the timer circuit 23
It is possible to confirm whether or not the light has been turned on by feeding it back to CplJ17 as a flash signal.

The flash trigger signal output from the CPU 17 and the flash signal input from the timer circuit 23 are shown in FIG.

When operating normally, the flash signal rises with a slight delay after the flash trigger signal rises, and falls later than the fall of the flash trigger signal, but for some reason the flash lamp 5
In the case where the flash signal does not emit light, there is no rise in the flash signal and it remains at a low level.

Therefore, when the flash trigger signal falls, if the flash signal is at a high level, it means that the flash lamp 5 is lit normally, and if it is at a low level, it means that the flash lamp 5 is not lit.

Therefore, the CPU 17 determines whether the flash lamp 5 is lit or not and controls the static elimination run 1162 indicator lamp 19, etc., and the operating procedure thereof is shown in flowchart 1- of FIG. 7 and will be explained.

First, a flash trigger signal is output to the flash lamp control circuit 26 (step 2), and then, at the falling edge of the flash trigger signal, it is determined whether the flash signal is at a high level or a low level.

Detect (step ■).

If the level is high, it is normal, and it is determined whether the number of copies has reached the preset number (step ■). If it has not reached the preset number, the process returns to step ■, and again steps ■, ■, ■
repeat.

When the number of copies reaches the set number, instruct the machine to cycle down (step ■) and end.

If the flash signal is at a low level at the time the flash trigger signal falls in step (3), it means that the flash lamp 5 did not light up due to some abnormality. In step (2), the static electricity is removed from the part of the belt-shaped photoreceptor 7 where an electrostatic latent image would normally be formed, the machine is cycled down (in step), and the indicator lamp 19 on the console panel is turned on. Turn it on (step ■) to indicate that a misflash has occurred.

In this way, in this embodiment, when the flash lamp 5 does not light up, the above-mentioned work is performed, so that black copies are not generated (to prevent wasteful consumption of toner, and to reduce the burden on the cleaning device). This also reduces the risk of image fogging later on.

In addition, after a misflash occurs, the copying machine can be stopped before transfer to copy paper, so when using a sorter, etc., it is possible to restart copying and continue work without having to replace the copy later. .

Furthermore, if a mis-flash occurs, a message will be displayed, so if the malfunction does not recover, measures can be taken such as requesting repair at the 9th period.

The present invention prevents wasteful consumption of toner by detecting a misflash and controlling the static eliminating means to eliminate static from the portion of the photoreceptor that would normally form an electrostatic latent image. In addition, the burden of cleaning can be reduced and subsequent image fogging can be avoided.

Further, since no black copy is generated and a mis-flash is displayed, it is convenient and facilitates the operator's subsequent work or measures.

[Brief explanation of drawings]

Fig. 1 is a diagram corresponding to the claims of the present invention, Fig. 2 is a schematic diagram of the interior of a full exposure type electrophotographic copying machine, and Fig. 3 is a brief explanation of the interior and control system of the copying machine according to an embodiment of the present invention. Figure 4 is a schematic block diagram of the control system in this embodiment, and Figure 5 is a schematic block diagram of the control system in this embodiment.
This figure shows the flash lamp control circuit of this embodiment, the sixth factor is a waveform diagram showing input/output signals to the CPU, and FIG. 7 is a chart 70 showing the operating procedure in this control system. 1... Copy machine casing, 2... Platen glass,
3...Platen cover, 4...Reflection member, 5...
Flash lamp, 6... Lens, 7... Belt-shaped photoreceptor, 8... Roll, 9... Charge corotron, 10... Developer, 11... Transfer corotron, 12
... Crim: Sung device, 13... Manuscript, 15...
Light amount sensor, 16... Division static elimination lamp, 11...
CPU, 18...Flash lamp power supply, 19...
- Display lamp, 20... Optical sensor, 21... Integrating circuit, 22... Comparing circuit, 23... Timer circuit, 25... AC power supply, 2G... Flash lamp control circuit, 27... Trigger power supply, 30... Relay switch, 31... Boost circuit, 32... Rectifier circuit, 3
3.34...Resistor, 35...Diode, 36...
・Capacitor, 31... Coil, 38... Resistor, 3
9... Thyristor, 40.41... Comparator.

Claims (1)

[Claims] In a full exposure type electrophotographic copying machine, a flash lamp for exposure, an exposure control means for controlling lighting of the flash lamp, a light detection means for detecting light from the flash lamp, and a light detection means for detecting light from the exposure control means are provided. Misflash detection means inputs a flash lamp lighting instruction signal and a detection signal from the light detection means and detects a case where the flash lamp does not turn on despite a lighting instruction;
A control means for controlling the drive of various internal devices based on the signal from the misflash detection means, a static elimination means for removing static electricity from the surface of the photosensitive material under the control of the control means, and a static elimination means that is controlled by the control means. display means for displaying a misflash when the misflash is detected by the misflash detection means, outputs a detection signal to the control means, and the control means drives the static eliminator to remove the static electricity. An electrophotographic copying machine characterized in that the display means performs the following operations, displays information using the display means, and further stops the driving of certain devices.