JPH03107873A - Photoconductor deterioration detection device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photoreceptor deterioration detection device that automatically detects deterioration of a photoreceptor installed in an electrophotographic apparatus or the like.

[Conventional technology]

Photoreceptors such as photoreceptor drums and photoreceptor healds installed in electrophotographic apparatuses tend to have an exposed portion potential vL that increases due to deterioration over time when they are used for boat fishing. As a result, the exposed part potential ■
When , increases, negative/positive development method (reversal development method)
In this case, the density of one image decreases, and eventually the photoreceptor itself must be replaced.

Therefore, in order to always maintain a proper image, the potential vL of the exposed portion of the photoconductor must be raised quickly and.

It becomes necessary to accurately detect and replace the photoreceptor.

Conventionally, as methods for detecting the above-mentioned exposed part potential (1), firstly, the surface potential (VL) of the photoreceptor is directly measured, and secondly, a reference pattern is developed on the photoreceptor, and the developed reference pattern is There is a method of detecting an increase in the exposed part potential VL as a change in the density of the reference pattern by detecting reflected light of the pattern using an optical sensor or the like.

[Problems to be Solved by the Invention] However, in the above conventional method of directly measuring the surface potential of a photoreceptor, a measuring device, a so-called detector, is required to measure the potential on the surface of the photoreceptor. Since the detector itself is very expensive, there is a problem in that if this method is adopted, the price of the device itself will be high.

In addition, in the method of creating a second reference pattern and detecting the exposed part potential (2) as a change in the density of the pattern, it is possible to continuously develop images with many black areas, or when the toner is used up. It is difficult to distinguish between a decrease in toner density when the toner is stored, and there is a risk of erroneous judgment.

The present invention has been made in view of the above.

It is an object of the present invention to accurately suggest the time to replace a photoreceptor by detecting an increase in the exposed part potential (1) due to deterioration of the photoreceptor itself at a relatively low cost and with high accuracy.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an image density detection means for detecting the amount of toner adhesion in a reference pattern formed on a photoreceptor as image density.

a comparison means for comparing the image density detected by the image density detection means with a control reference value as a minimum image density value required to ensure a proper image density; and a toner in a developing device for the photoreceptor. a remaining toner amount detection means for detecting the remaining amount; the remaining toner amount detection means detects the presence of toner; and the comparison means determines that the image density detected by the density detection means is less than or equal to the control reference value. When I did,
The present invention provides a photoreceptor deterioration detection device comprising a control means for determining deterioration of the photoreceptor and a display means for displaying deterioration of the photoreceptor.

[Effect]

In the photoreceptor deterioration detection device according to the present invention.

Create a reference pattern on the photoreceptor, detect the amount of toner adhesion in the reference pattern as image density, and control as the minimum image density value required to ensure a preset appropriate image density. When the image density in the reference pattern is determined to be lower than the control reference value by comparison with the reference value, and the remaining toner amount detection sensor in the developing means still detects the presence of toner, it is determined that the photoreceptor has deteriorated. death,
Display that fact.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A photoconductor deterioration detection device according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an explanatory diagram showing the overall configuration of a photoconductor deterioration detection device according to the present invention, including charging processing, exposure processing, development processing,
A photoreceptor drum 101 that performs a transfer process, etc., and a developing device 1 that performs the development process on the photoreceptor drum 101.
00, the developing device 100 includes a removable toner cartridge 108 that supplies toner to the inside of the developing device 100.
and.

an agitator 109 that stirs the toner in the toner cartridge 108 and pushes it toward the photoreceptor 101; a toner replenishment roller 106 that replenishes the toner pushed out by the agitator 109 to the developing tank 105 via a toner hopper 107; and the toner replenishment roller A drive circuit 116 that drives the toner hopper 106 and a drive circuit 116 installed in the toner hopper 107.

A toner remaining amount sensor 110 detects the remaining amount of toner by the oscillation output of a piezoelectric element, and a stirring roller 10 is provided in the developing tank 105 to stir the toner replenished by the toner replenishing roller 106 and convey it toward the developing roller 103.
4, a developing roller 103 that performs development processing on the photoreceptor drum 101, a doctor 113 that regulates the toner on the surface of the developing roller 103 to a constant amount, and 1 a stirring roller that reuses the toner scraped off by the doctor 113. 104, and a stirring separator 111 for stirring processing.

Further, in the vicinity of the photoreceptor drum 101, an optical sensor (for example, a A combination of a light emitting diode and a phototransistor) 102 is installed.

Further, a control unit (for example, a microcomputer) 11 inputs sensor signals from the optical sensor 102 and the remaining toner amount sensor 110 to determine the deterioration state of the photosensitive drum 101.
4, and a display section 115 for externally displaying various information output based on predetermined arithmetic processing within the control section 114.

The operation of the above configuration will be explained based on the flowchart shown in FIG.

As a premise for the control in the flowchart, specific numerical examples are set as follows.

In normal toner replenishment, the optical sensor 102 detects the background part (the part on the photoreceptor where no toner is attached).

At the time of 4■, toner replenishment is executed when the output of the reference pattern is 0.5V or more, and on the other hand, when it becomes 0.5V or less, toner replenishment is stopped.

In addition, the output from one reference pattern is 0.9V or more 5 times (
For example, when a reference pattern is created once for copying 10 originals, the toner end message is displayed when the toner pattern is output continuously.

On the other hand, the remaining toner amount sensor 110 determines that there is toner when the value is 0.5V or more, and outputs a toner end signal when the output value is 0.5V or less.

Based on the above premise, the control unit 114 secondly determines whether the output of the remaining toner amount sensor 110 is 0.5 V or more (201). Here, if the control unit 114 determines that the output of the remaining toner amount sensor 110 is 0.5 V or less, the control unit 114 outputs a toner end signal to the display unit 115 (202). 115 indicates that the amount of toner remaining in the toner hopper 107 is low (2
03).

On the other hand, when the control unit 114 determines that the output of the remaining toner amount sensor 110 is 0.5V or more, the following control is executed.

- When fishing on a boat, the toner supplied into the developing tank 105 by the toner cartridge 108 is stirred by the stirring roller 104, conveyed to the developing roller 103, and subjected to charging processing.
Toner is supplied to the electrostatic latent image formed on the photoreceptor drum 101 through exposure processing, and development processing is executed. At this time, a reference pattern for image density detection is created on the photosensitive drum 101 (204). The toner density (toner adhesion amount) of the created reference pattern is detected by the optical sensor 102 (205), and the detected image density information is output to the control unit 114.

The control unit 114 compares the image density information value of the reference pattern with a control reference value meaning the minimum image density value required to obtain an appropriate image density, which is stored in advance (206). Therefore, the control unit 114 determines whether the image density value (optical sensor output) of the reference pattern is 0.9 V or less (207).

If the control unit 114 determines that the optical sensor output is 0.9V or less, a toner replenishment signal is output from the control unit 114 to the toner replenishment roller 106 via the drive circuit 116 (208), and normal toner replenishment is performed. The process is executed (2
09). On the contrary, the control unit 114 has a light sensor output of 0.9.
If it is determined that the photoreceptor is V or more, the control unit 114 outputs a photoreceptor deterioration signal to the display unit 115 (210), and the display unit 115 displays that the photoreceptor has deteriorated and needs to be replaced. (211), the series of controls ends.

As described above, the second invention creates a reference pattern.

By installing a means to control the image density on the photoconductor and a means to detect the amount of toner remaining in the device, it is possible to
It maintains a proper image density on the photoconductor, displays the end of toner before the image density decreases when toner is finished, and furthermore, when the image density value decreases due to deterioration of the photoconductor, not based on the end of toner, Displays deterioration of the photoreceptor itself,
It is possible to instruct replacement of the photoreceptor based on deterioration of the photoreceptor.

In the above embodiment, the toner remaining amount sensor is provided in a part of the toner hopper, but it may be provided in the toner cartridge. Further, although a piezoelectric sensor is used as the toner remaining amount sensor, a tuning fork type sensor, a transmitted light detection sensor, or a mechanical sensor may also be used.

〔Effect of the invention〕

As explained above, in the photoconductor deterioration detection device according to the present invention, a reference pattern is created for the photoconductor-L, and the amount of toner adhesion in the reference pattern is detected as the image density, and a preset appropriate It is determined that the image density in the reference pattern is lower than the control reference value by comparing it with the control reference value as the minimum image density value required to ensure the image density, and the amount of toner remaining in the developing means is determined to be lower than the control reference value. When the detection sensor is still detecting the presence of toner, it is determined that the photoreceptor has deteriorated, and a message to that effect is displayed, so that the increase in the exposed part potential due to the deterioration of the photoreceptor itself can be suppressed relatively inexpensively and By detecting this with high accuracy, it is possible to accurately suggest when to replace the photoreceptor.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the overall configuration of a photoreceptor deterioration detection device according to the present invention, and FIG. 2 is a flowchart showing the operation of the photoreceptor deterioration detection device according to the present invention. Description of symbols 100 - Developing device 101 - Photosensitive drum 102 - Optical sensor 103 - Developing roller 105...-Developing tank 106...Toner supply roller 107--Toner hopper 108...Toner cartridge

Claims (1)

[Scope of Claims] Image density detection means for detecting the amount of toner adhesion in a reference pattern formed on a photoreceptor as image density; and ensuring an appropriate image density for the image density detected by the image density detection means. a comparison means for comparing with a control reference value as a minimum required image density value; a remaining toner amount detecting means for detecting the amount of toner remaining in the developing device with respect to the photoreceptor; and the remaining toner amount detecting means. detects the presence of toner, and when the comparison means determines that the image density detected by the density detection means is equal to or less than the control reference value, a control means for determining deterioration of the photoreceptor; 1. A photoconductor deterioration detection device comprising: display means for displaying deterioration of a photoreceptor.