JPS60173571A - Fatigue degree display device of photosensitive body of electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To grasp exactly a replacement time of a photosensitive body by integrating and counting a quantity which increases cumulatively following an increase of the number of times of copying, and displaying it as a degree of fatigue of the photosensitive body. CONSTITUTION:Pulses of the number proportional to the number of copy sheets are supplied to a set terminal 2 of an integrating and counting circuit 1, and they are integrated by the integrating and counting circuit 1, but until its counting value reaches x1, a comparator 6 generates an output in an output terminal 11, and a voltage generator 7 supplies a voltage V1 to a developing electrode 8. Also, a light emitting diode L1 is lighted, and it is displayed that a life of a photodetecting body 4 is left enough. Until an integrating value of the number of copy sheets exceeds x1 and reaches x2, the voltage generator 7 supplies a voltage V2 of a larger value than said V1 to the developing electrode 8, as shown in the figure, and compensates deterioration of a performance caused by fatigue of the photosensitive body 4. Also, as the number of copy sheets increases, the voltage applied to the developing electrode 8 is increased as V3 and V4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for displaying the degree of fatigue of a photoreceptor in an electronic copying machine.

In electronic copying machines, one photoreceptor is repeatedly charged and exposed to light, which causes fatigue of the photoreceptor, and this fatigue is caused by an increase in the dark decay rate or an increase in the residual potential. This causes a decrease in the image density and contrast of the copy. Therefore, it is necessary to detect the degree of fatigue of the photoreceptor and, when it reaches a limit, to replace the photoreceptor. This fatigue level is a function of the number of copies, so
The degree of fatigue can be detected by counting the amount of change, but since it is also affected by the exposure meter, copy size, amount of charge, etc., the degree of fatigue must be determined by counting and integrating the amounts of change.

Furthermore, once the photoreceptor is replaced, the fatigue level of the next photoreceptor cannot be detected unless the cumulative count is reset.

The present invention aims to solve the above problems, and the figures show an embodiment thereof.

Reference numeral 1 denotes an integration counting circuit which integrates and counts the pulses applied to the set terminal 2, and has a built-in memory that is not reset even when the power is turned off. The memory is reset only when there is an input to the reset terminal 3. The pulse applied to the set terminal 2 is
Although it may be only proportional to the number of copies, which is the largest factor in fatigue, it is preferable that it be corrected by each of the above-mentioned variations.

The output of the integration counting circuit 1 is input to the comparison circuit 6 together with the output of the program circuit 5. This program circuit 5 is set with conditions obtained through experiments in advance.

The comparator circuit 6 compares the output of the integration counter circuit 1 and the output of the program circuit 5, and provides an output corresponding to the output to one of the plurality of output terminals 11 to 14. This output terminal 1
The fv voltage generator 7 connected to the terminals 1 to 14 supplies the developing electrode 8 with a voltage of a value corresponding to which output terminal 11 to 14 receives the input. L1 to L4 are light emitting diodes connected to each of the output terminals 11 to 14, respectively, and display the degree of fatigue of the photoreceptor 4 in stages.

An AND gate 9 is connected to the reset terminal 3 of the integration counting circuit 1.
The reset leg button switch 10 is connected through the reset leg button switch 10, and the other input terminal of the AND gate 9 is connected to the output terminal 14 of the comparison circuit 6.

Next, the operation of the device will be explained.

A number of pulses proportional to the number of copies are supplied to the set terminal 2 of the integrating counting circuit 10, and the pulses are integrated by the integrating counting circuit 1, but until the first count reaches xl, the comparator circuit 6 outputs An output is generated at the terminal 11, and the voltage generator 7 supplies the developing electrode 8 with a voltage of 1. The light emitting diode L1 is still lit, indicating that the photoreceptor 4 has a sufficient life remaining.

When the cumulative value of the number of copies exceeds xI, the comparator circuit 6 generates an output at the output terminal 12, and the cumulative counting circuit 1
This state continues until the count value reaches x2. Thereby, as shown in FIG. 2, the voltage generator 7 supplies the developing electrode 8 with a voltage of a value V2 which is smaller than the above-mentioned V, thereby compensating for performance deterioration due to fatigue of the photoreceptor 4. Also, output terminal 1
The light emitting diode L2 connected to the photoreceptor 2 lights up to indicate that the fatigue level of the photoreceptor 4 is at the second stage.

As described above, as the number of copies increases, the voltage applied to the developing electrode 8 is increased to V3. V.

However, when it reaches a stage where it is no longer possible to compensate for the deterioration in performance, the photoreceptor 4 must be replaced.

The fact that this stage has been reached can be known by the light emission of the light emitting diode L4, which indicates the final stage. That is,
When the number of copies exceeds x3, output terminal 1 of comparison circuit 6
4, the voltage applied to the developing electrode 8 is set to v4, and the light emitting diode L4 is turned on. The output of the output terminal 14 is also supplied to the AND gate 9, but since the reset leg button switch 10 is turned off, the integration counting circuit 1 is not reset.

Leg button switch 10 for resetting when photoconductor 4 is replaced
When is pressed, an input is given to the reset terminal 3 of the integrating counting circuit 1, so that the integrating counting circuit 1 is reset and starts counting the fatigue level of the next photoreceptor 4 again from zero.

If the reset leg button switch 1o is operated in conjunction with the attachment/detachment of the photoconductor 4, erroneous operation will not occur, and during repairs, etc., the photoconductor can be attached/detached before it reaches the end of its service life. Even if this is done, no malfunction will occur due to the action of the AND gate 9. In the case of a type in which the photoreceptor 4 is built in the drum and is fed out sequentially after use, a reset signal is issued in response to a photoreceptor feeding command.

Note that if the light emitting diodes L and L4 are of different colors, the fatigue stage of the photoreceptor 4 becomes clear.

Further, only the final stage may be displayed using one light emitting diode, or a lamp may be used instead of the light emitting diode.

As described above, the present invention cumulatively counts the amount that increases cumulatively as the number of copies increases and displays it as the fatigue level of the photoreceptor, so it is possible to accurately know when to replace the photoreceptor. Since the counting amount is reset by replacing the photoreceptor, there is no possibility of erroneously resetting it during use.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention, and FIG. 2 is a graph showing the relationship between the number of copies and the developing voltage. 1... Integration counting circuit, 2... Set terminal, 3...
Reset terminal, 4... Photoreceptor, 5... Program circuit, 6... Comparison circuit, 7... Voltage generator, 8...
Developing electrode, 10...Reset leg button switch, L
, ,L2. L3. L... Light emitting diode. Patent applicant Rico Co., Ltd. −

Claims (1)

[Claims] A counter that cumulatively counts the amount of change of one or more types that increases cumulatively as the number of copies increases, and the output of the counter is compared with a set value to change the control amount in the copying process. An electrostatic copying machine comprising a control device, wherein the degree of fatigue of the photoreceptor is displayed by the output of the counter, and the counter is reset by replacing the photoreceptor. Photoconductor fatigue level display device for photocopiers.