JPH06236090A - Device for measuring characteristic of photo drum - Google Patents

Abstract

PURPOSE:To provide a device for measuring the characteristic of a photoreceptor drum capable of accurately measuring exposure without previously measuring light quantity at a position equivalent to an exposed surface or applying the measured value of an illuminance measuring sensor by putting the sensor around the exposed surface. CONSTITUTION:The characteristic measuring device measuring electric characteristic by performing at least charging and exposure to the photoreceptor drum is constituted of a charging means 2 for charging the photoreceptor drum 1, an exposure means 3, a half mirror 4 branching part of exposing light in the case of changing the exposure and measuring potential damping amount, a light quantity sensor 5 measuring the quantity of branched light, and a potential measuring means 6. A light source, the half mirror and the light quantity sensor can be set outside an environment chamber in which the photoreceptor drum is housed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a characteristic measuring device for measuring the electric characteristic of a photosensitive drum used in copying machines, printers and the like.

[0002]

2. Description of the Related Art In a photoconductor drum, characteristics such as charging property and sensitivity are very important. To obtain the physical properties, charging is performed while rotating the photoconductor drum, and then exposure is carried out. Electrical potential is being measured.
At that time, the exposure amount is an important value for determining the sensitivity,
You need to know the exact value. However, since the photosensitive drum is usually present on the exposed surface, the exposure amount cannot be accurately known. Therefore, conventionally, the amount of light is measured in advance at a position corresponding to the exposed surface, or, for example, the actual flatness 4-
As described in Japanese Patent No. 18849, an illuminance measuring sensor is placed around the exposed surface and the measured value is used. However, in the former case, even if the exposure amount changes due to deterioration of the light source, fluctuation of voltage, etc., it cannot be detected. In the latter case, the exposure amount changes due to the deviation of the optical system. I was afraid to do it.

[0003]

SUMMARY OF THE INVENTION According to the present invention, the amount of light is previously measured at a position corresponding to the exposed surface, or an illuminance measuring sensor is placed around the exposed surface and the measured value is used. It is an object of the present invention to provide a device for measuring characteristics of a photoconductor drum that can accurately measure an exposure amount without performing the above.

[0004]

A characteristic measuring device for measuring characteristics of a photosensitive drum according to the present invention comprises a charging means for charging the photosensitive drum, an exposing means, and a potential attenuation by changing an exposure amount. When measuring the quantity, a half mirror for partially branching the light to be exposed, a light quantity sensor for measuring the quantity of the branched light, and a potential measuring means are provided. In the characteristic measuring device of the present invention, the light source, the half mirror, and the light amount sensor may be installed outside the environment chamber that houses the photosensitive drum.

[0005]

In the characteristic measuring apparatus of the present invention, after the photosensitive drum is charged, when the exposure amount is changed and the potential attenuation amount is measured, the light to be exposed is partially branched by the half mirror, and the light amount thereof is divided. While measuring, the photosensitive drum is exposed. Then, the light quantity of the light branched by the half mirror is converted into the exposure quantity on the drum surface and used. In that case, since the illuminance measuring sensor is not placed and the measured value is not diverted, the exposure amount can be accurately known. Further, according to the characteristic measuring device of the present invention, since a part of the light amount is constantly monitored, even if the exposure amount changes due to deterioration of the lamp, fluctuation of voltage, etc., it can be detected. When using the characteristic measuring device of the present invention, the illuminance is measured in advance at a position corresponding to the exposed surface of the photosensitive drum, and the relationship between the amount of light on the exposed surface and the amount of light branched by the half mirror is grasped in advance. It is necessary to leave. Sensitivity measurement of the photoconductor drum is performed by applying a constant charge to the photoconductor drum, changing the exposure amount, measuring the light amount value branched by the half mirror, and converting it to the light amount on the photoconductor drum surface. Can be performed by measuring the amount of potential attenuation of the photosensitive drum.

[0006]

Embodiments of the present invention will now be described with reference to the drawings. The drawings show a schematic configuration of an example of the characteristic measuring apparatus of the present invention. FIG. 1 is a schematic plan view and FIG. 2 is a schematic sectional view. The characteristic measuring device includes a charger 2 for charging the photosensitive drum 1, a lamp 3 for exposing the photosensitive drum, a half mirror 4 for partially branching the light to be exposed,
It has a light quantity sensor 5 for measuring the light quantity of the branched light, and a potential measuring probe 6 for measuring the charging potential,
Then, the lamp 3, the half mirror 4, and the light amount sensor 5
Is arranged outside the environmental chamber 7 that houses the photosensitive drum 1. A filter 8 is provided in the light path of the light from the lamp 3.
And a shutter 9 is provided. In addition, 10 is a control device for controlling the light amount, and 11 is a static elimination lamp.

First, in using this characteristic measuring device, before mounting the photosensitive drum 1, an illuminance measuring sensor is placed at the exposure position of the photosensitive drum, and the lamp 3 is turned on to measure the light amount at the exposure position. And half mirror 4
The amount of light branched at is measured by the light amount sensor 5, and the relationship between both measured values is grasped in advance. The measured value may be stored in the computer. Next, the photosensitive drum 1 to be measured is
It is installed in the environment room 7 of the characteristic measuring device. Control device 10
The photoconductor drum 1 is rotated and the static elimination lamp 11 is turned on by the control from. After that, a constant charge is applied to the photoconductor drum 1 from the charger 2, and then the filter 8 is controlled by the controller 10 in an arbitrary combination.
The exposure amount applied to the photosensitive drum 1 is changed, the exposure is performed by the shutter 9 with appropriate timing, and the potential is measured by the potential measuring probe 6. After the measurement is completed, the voltage application by the charger 2 is stopped, and the photosensitive drum 1
The static elimination lamp 11 is turned on while rotating to eliminate static electricity. Finally, the measured photosensitive drum 1 is removed from the characteristic measuring device. The environment room 7 is kept in a dark place.

In the above case, since the charger, the lamp, the half mirror and the light quantity sensor are arranged outside the environment chamber containing the photosensitive drum, malfunctions and errors due to changes in the environment can be prevented. .

[0009]

According to the characteristic measuring device for a photosensitive drum of the present invention, the characteristic is measured while constantly monitoring the exposure amount to the photosensitive drum, so that the potential can be accurately measured. As a result, even if there is deterioration of the lamp, fluctuation of the voltage of the lamp, etc., it is possible to evaluate the characteristics of the photoconductor drum without including an error in the exposure amount data. It is also possible to predict lamp burnout by lighting the lamp at a constant current and constantly monitoring the amount of change in the voltage. For example, it is possible to set the voltage value near the lamp burnout to 20% higher than the normal voltage value and issue a warning to the measurer. Further, in the characteristic measuring device of the present invention,
When the light source, the half mirror, and the light amount sensor are installed outside the environment chamber that houses the photosensitive drum, it is possible to accurately measure the characteristics of the photosensitive drum by changing the environment. That is, in this case, since the exposure amount can be monitored under a constant condition, the light amount value becomes reliable data and accurate measurement becomes possible.

[Brief description of drawings]

FIG. 1 is a schematic plan view of an embodiment of a characteristic measuring device of the present invention.

FIG. 2 is a schematic cross-sectional view of an embodiment of the characteristic measuring device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photosensitive drum, 2 ... Charger, 3 ... Lamp, 4 ... Half mirror, 5 ... Light amount sensor, 6 ... Potential measuring probe,
7 ... Environmental room, 8 ... Filter, 9 ... Shutter, 10 ...
Control device, 11 ... Static elimination lamp.

Claims (2)

[Claims] 1. A characteristic measuring apparatus for measuring electrical characteristics by at least charging and exposing a photosensitive drum, wherein a charging unit for exposing the photosensitive drum, an exposing unit, and an exposure amount are varied to reduce a potential. A characteristic measuring device comprising: a half mirror for partially branching the light to be exposed, a light amount sensor for measuring the light amount of the branched light, and an electric potential measuring means when the measurement is performed. 2. The characteristic measuring device according to claim 1, wherein the light source, the half mirror, and the light amount sensor are installed outside an environment chamber accommodating the photosensitive drum.