JPS6129503B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an apparatus for accurately correcting fatigue of a photoreceptor of an electronic copying machine having a plurality of copying modes, such as an electronic color photocopying machine or an electronic copying machine that also serves as a printer. The characteristics of the photoconductor in an electronic copying machine gradually deteriorate due to repeated exposure, charging, and neutralization, and even if the same amount of light is irradiated under the same charging conditions, the residual potential changes, which causes the photoconductor that corresponds to the image background to deteriorate. As the potential of the area increases and the number of copies increases, the background area is also developed, causing so-called background staining on the copies, and the electrostatic potential due to the charger decreases, resulting in a decrease in copy density. In order to correct such fatigue of the photoreceptor, it has been considered to correct the developing bias voltage according to the total number of copies, as shown in Japanese Patent Application Laid-open No. 32333/1982, but with this method, the fatigue of the photoreceptor is Even if the fatigue value can be corrected to some extent, there is a drawback that as the number of copies increases, the fatigue value deviates from the actual fatigue value and cannot be completely corrected. The present invention focuses on the fact that in an electronic copying machine having multiple copying modes, there is a difference in the degree of fatigue of the photoreceptor during the electrophotographic copying process in each mode, and counts the number of times the electrophotographic copying process is performed in a certain mode. It has a counter, and a control signal generating device that is proportional to the sum of the value counted by the counter and the multiplicative value of the photoconductor fatigue coefficient of this mode, and uses this control signal to control the amount of exposure, amount of charge, At least one of the developing bias voltages is controlled to perform a complete correction that matches the actual fatigue value, thereby eliminating the drawbacks of the conventional method. Next, the method of the present invention will be explained in detail with respect to each embodiment shown in the accompanying drawings. FIG. 1 shows an electronic color photocopying apparatus, where 1 is a photosensitive drum and 2 is a rotary filter in the optical system, which can convert images into green, blue, and red, for example. 3, 4, and 5 correspond to the colors of filter 2, such as magenta, yellow,
A developing device containing cyan toner, 6 a transfer drum, and 7 transfer paper. When performing color copying, the filter 2 is changed to green, blue, or red for each scan of the optical system, and the image is developed on the photoreceptor drum 1 using the developing devices 3, 4, and 5 corresponding to the color.
The toner images of each color are transferred to the transfer paper 7 clamped on the transfer drum 6, and the transfer paper 7 has completed the transfer process.
is peeled off from the transfer drum 6 and fixed by a fixing device. In the case of monochrome copying, a filter is generally not used and the desired color is developed, and the transfer paper 7 is guided on the surface of the transfer drum 6 to transfer and fix. In such a color copying apparatus, since the effects of the charging and exposure process on the photoreceptor are different between color copying and monochrome copying, large errors will occur if fatigue of the photoreceptor is corrected simply by the number of copies. In color copying, the photoreceptor is used about three to four times as much as in monochrome copying.
Furthermore, in the case of color copying and single-color copying, the degree of fatigue caused by exposure differs depending on the wavelength of each color's light, and the amount of exposure varies depending on the color.Furthermore, in order to improve color reproducibility, charging is done by changing the charge input, etc. The amount may change. The present invention focuses on the difference in the degree of fatigue of the photoreceptor according to each color mode, and as shown in Table 1, the fatigue coefficient in each color mode is determined in advance, and the number of electrophotographic copying steps in each color mode is counted. The sum of the synergistic values of this value and the fatigue coefficient αa+βb+
γc+δd is determined, and a control signal proportional to this is obtained.

[Table] Fig. 2 shows a printer/copying device, in which 10 is a photoreceptor drum, 11 is an original copying light source, 12 is a cathode tube that converts signals from a computer into light and irradiates it onto the photoreceptor drum 10, and 13 is a toner developer. The device 14 is a transfer paper. General originals can be copied by scanning the original copying light source 11,
In addition, signals from a computer can be printed by the cathode tray tube 12, and by using these two functions simultaneously, it is also possible to have the computer write on top of an ordinary copy, and conversely, when performing data processing. For example, by using the mode of use as a copying machine (copy mode) to copy a fixed frame of printing paper, etc., and at the same time writing data or calculation results etc. using the cathode tray tube 12 (print mode), This eliminates the need for additional devices such as memory. In such a device, the properties of the irradiated light are different in the copy mode and the print mode, so there is a difference in the fatigue state of the photoreceptor, and the total number of copies or prints as output, that is, the electrophotographic copying process. Correcting the fatigue of the photoreceptor based on the total number of repetitions results in a large error. As shown in Table 2, the present invention determines the fatigue coefficient in each mode in advance, counts the number of repetitions in each mode, and calculates the sum of αa + βb of the synergistic value of this value with the fatigue coefficient. , a control signal proportional to this is obtained.

[Table] FIG. 3 shows an embodiment of a control signal generating device using mechanical means. That is, when solenoids B, C, and D are activated by signals from each mode, each of the cams A', B', C', and D' rotates once. cam
The shapes of A', B', C', and D' are formed according to the fatigue coefficient of each mode.
The swing range of 0, 21, 22, and 23 is restricted. Each cam follower is connected at one end to a one-way clutch 25, 26, 27, 28 attached to the rotating shaft 24, and each rotation of each cam A', B', C', D' is rotated through an angle commensurate with its fatigue coefficient. Therefore, the rotating shaft 24 rotates in proportion to the sum value αa+βb+γc+δd or αa+βb in Table 1 or Table 2 mentioned above. A gear 29 is provided at the end of the rotating shaft 24.
is attached and meshes with the large gear 30, and the gear 2
A contact 31 for the resistor R is attached to 9 so that a control signal can be obtained. This control signal controls at least one of the exposure amount, charging voltage, and developing bias voltage, and also changes the input of the pilot lamp 32 to display the usable number of photoconductors, a photoconductor replacement instruction display, or a photoconductor replacement instruction. It can also be used as a command to operate an automatic exchange device or as a signal to stop a machine. FIG. 4 shows an embodiment of a control signal generating device using electrical means. A signal corresponding to the number of copying steps in each mode enters each input interface A'', B'', C'', D'', and this signal is processed in each mode by a well-known arithmetic circuit 30 according to instructions from a predetermined program circuit. Fatigue coefficient α, β, γ, δ
is multiplied by , and its output is stored in the non-luminescent memory 31. The accumulated output from the non-luminescent memory 32 is returned to the arithmetic circuit CPU, and via the output interface 31 becomes a control signal or a signal indicating the life status of the photoreceptor. According to the present invention, in an electronic copying machine having multiple copying modes, the degree of fatigue of the photoconductor is measured based on the fatigue coefficient corresponding to each mode, and the fatigue of the photoconductor is corrected using a control signal based on the fatigue coefficient. This method has the advantage of being able to perform extremely accurate corrections.

[Brief explanation of the drawing]

FIG. 1 is a front view of a first embodiment of the apparatus for carrying out the method of the present invention, FIG. 2 is a front view of the second embodiment of the apparatus,
FIG. 3 is a perspective view of a first embodiment of a control signal generating device according to the method of the present invention, and FIG. 4 is an electric circuit diagram of a second embodiment of the same. 1...Photosensitive drum, 2...Rotating filter,
3, 4, 5...Developing device, 6...Transfer drum, 7
... Transfer paper, 10 ... Photosensitive drum, 11 ... Original copying light source, 12 ... Cathode tray tube, 1
3...Developing device, 14...Transfer paper, A, B, C,
D... Solenoid, A', B', C', D'... Cam,
20, 21, 22, 23...cam follower, 24
... Rotating shaft, 25, 26, 27, 28 ... One-way clutch, 29, 30 ... Gear, 31 ... Contactor, 32 ... Pilot lamp, R ... Resistance,
A″, B″, C″, D″……Input interface, 3
0... Arithmetic circuit, 31... Non-luminous memory, 32
...Output interface.

Claims (1)

[Scope of Claims] 1. A transfer type that repeatedly uses the same photoreceptor, which has a plurality of copying modes that differ in the degree of fatigue of the photoreceptor, and any one mode or multiple modes can be performed simultaneously. An electronic copying machine has a counter that counts a numerical value corresponding to the electrophotographic copying process of each mode, and is proportional to the sum of the fatigue coefficient of the photoreceptor corresponding to each mode and the synergistic value of the above numerical value. A fatigue correction device for a photoreceptor, comprising a control signal generating device, and controlling at least one of an exposure amount, a charging amount, and a developing bias voltage using the control signal. 2. An electronic color photocopying device has a counter that counts a numerical value corresponding to the electrophotographic copying process of each color mode, and the sum of the fatigue coefficient of the photoreceptor corresponding to each color mode and the synergistic value of the above numerical value 2. Device according to claim 1, comprising a proportional control signal generator. 3. An electronic copying device that also serves as a printer has a counter that counts numerical values corresponding to the electrophotographic copying process in copy mode and print mode,
2. The apparatus according to claim 1, further comprising a control signal generating device proportional to the sum of the multiplicative value of the fatigue coefficient of the photoreceptor corresponding to the copy mode and the print mode, respectively, and the numerical value. 4 having a counter for counting a numerical value corresponding to the electrophotographic copying process in each mode, and having a control signal generating device proportional to the sum of the synergistic value of the fatigue coefficient of the photoreceptor corresponding to each mode and the numerical value; Claims 1 to 3, wherein the control signal is linked to a photoconductor life status display device such as the remaining number of usable copies of the photoconductor, a photoconductor usage stop signal, and a photoconductor replacement command signal. Apparatus described in section.