JPH07152160A - Photoconductor characteristic evaluation device - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention is capable of simultaneously measuring the light reflection intensity of a photoconductor when measuring the photosensitivity of the photoconductor, thereby reducing the photoconductor defect due to mishandling and shortening the photoconductor inspection time. The purpose is to measure. According to the present invention, in an apparatus for evaluating a characteristic of a photoconductor having a charging unit 12, an exposing unit 13, a discharging unit 16, and a surface potential measuring probe 14, the exposing unit 1 in a photoconductor 11 is
3, a light emitting / receiving element 15 for irradiating the position outside the exposure range by 3 to detect the intensity of the reflected light from the photosensitive element 11 in the rotation direction of the photosensitive element 11, and an output signal of the light receiving / emitting element 15 are calculated. The calculation display units 19 and 20 for displaying the above are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoreceptor characteristic evaluation apparatus for evaluating the characteristics of a photoreceptor used in an image forming apparatus such as an electrophotographic copying machine.

[0002]

2. Description of the Related Art Conventionally, as a photoconductor characteristic evaluation device, a photoconductor drum characteristic measurement device described in JP-A-4-26852 is known. This apparatus is equipped with a photosensitive drum of an image forming apparatus such as a copying machine, and has a rotating means for rotating the photosensitive drum. A charging device, an exposure device, a surface potential sensor, and a charge eliminating device are sequentially arranged around the photosensitive drum in the rotation direction. A laser light source is used for the exposure device, and the surface potential sensor is provided so as to be movable in the axial direction of the photosensitive drum.

This photosensitive drum is rotated by a rotating means and uniformly charged by a charging device, and the charging potential for one revolution (dark potential of the photosensitive drum) is measured by a surface potential sensor. After that, the photoconductor drum is destaticized by the destaticizing device and exposed to the laser beam by the exposure device, and the potential of the exposed portion for one revolution (bright potential of the photoconductor drum) is measured by the surface potential sensor.

Further, conventionally, in an image forming apparatus such as an electrophotographic copying machine, in order to detect occurrence of an accident (jam) in which transfer paper or the like is wrapped around the outer periphery of a photosensitive drum,
Alternatively, in order to always obtain a constant image density, a detection device that irradiates the photosensitive drum with light and receives the reflected light is provided, and the intensity of the reflected light that enters the detection device from the photosensitive drum is used as a reference. , Intensity of reflected light that enters the detector from a transfer paper wrapped around the outer periphery of the photosensitive drum, or intensity of reflected light that enters the detector from an image of a developed reference density document on the photosensitive drum The signal is compared by comparing with.

A reflection type photosensor is generally used as the detection device, and the peak oscillation wavelength of the light emitting element in this reflection type photosensor is at a level of 940 nm. This wavelength is not absorbed by the photoconductive layer (selenium layer) of the photosensitive drum, and most of it reaches the substrate (generally aluminum) of the photosensitive drum and is reflected by the surface thereof. The light reflected by the surface of the photoconductive layer of the photosensitive drum and the light reflected by the base of the photosensitive drum are detected by the light receiving element of the reflective photosensor.

In this case, the light reflected by the surface of the photoconductive layer of the photoconductor drum and the light reflected by the substrate of the photoconductor drum are detected by the light receiving element of the reflection type photo sensor, and the light is emitted from the photoconductor drum. Since the intensity of the reflected light incident on the reflection type photo sensor is used as a reference, in order to keep the light reflectance of the photoconductor drum constant, the unevenness of the unevenness of the substrate surface of the photoconductor drum and the unevenness of the photoconductive layer surface are uneven. Roughness variation is required to be constant.

Therefore, conventionally, in order to confirm that the intensity of the reflected light from the photosensitive drum is at a constant level, the photosensitive drum is mounted in an image forming apparatus and reflected from the photosensitive drum. The intensity of light was measured, and the intensity of light reflected from the photosensitive drum was measured with a dedicated measuring device.

[0008]

In the above image forming apparatus, the photoconductor drum is mounted on the image forming apparatus to measure the intensity of the reflected light from the photoconductor drum, or a dedicated measuring device is used to measure the intensity of the light from the photoconductor drum. Since the intensity of the reflected light was measured, the chances of taking the photosensitive drum in and out of the image forming apparatus increased, and the number of defective photosensitive drums increased due to mishandling.
Since light is applied to the photosensitive drum once, the dark adaptation time is required, and the inspection time of the photosensitive drum is increased.

The present invention solves the above-mentioned drawbacks, and at the same time when measuring the photosensitivity of the photoconductor, it is possible to measure the light reflection intensity of the photoconductor at the same time. It is an object of the present invention to provide a photoconductor characteristic evaluation device capable of shortening the above.

[0010]

In order to achieve the above object, the invention according to claim 1 is arranged such that a charging portion for charging the photosensitive member is provided around a position where the photosensitive member is attached and detached, and the photosensitive member. Having an exposure unit for performing exposure on the surface, a charge removal unit for removing charge from the photoconductor, and a surface potential measurement probe for measuring the surface potential of the photoconductor, and the measurement by the surface potential measurement probe by rotating the photoconductor. In a photoconductor characteristic evaluation device for evaluating the characteristic of the photoconductor by a value, the intensity of the reflected light from the photoconductor is measured by irradiating light to a position outside the exposure range of the exposure unit of the photoconductor. The light emitting / receiving element for detecting the rotation direction of the light emitting element and the calculation display section for calculating and displaying the output signal of the light receiving / emitting element are provided.

According to a second aspect of the present invention, the photoreceptor characteristic evaluation apparatus according to the first aspect is provided with a plurality of the light emitting / receiving elements.

[0012]

According to the first aspect of the invention, the photosensitive member is rotated and charged by the charging section, and the charging potential is measured by the surface potential measuring probe. Further, the photoconductor is decharged by the charge removing unit, then charged by the charging unit and exposed by the exposing unit, and the surface potential thereof is measured by the surface potential measuring probe. Further, the light emitting / receiving element emits light to a position outside the exposure range of the exposure section of the photoconductor to detect the intensity of the reflected light from the photoconductor in the rotation direction of the photoconductor, and the calculation display section displays Calculate and display the output signal.

According to a second aspect of the present invention, in the photoconductor characteristic evaluation apparatus according to the first aspect, the plurality of light receiving and emitting elements irradiate light to a position outside the exposure range of the exposure section of the photoconductor to remove the light from the photoconductor. The intensity of the reflected light is detected in the rotation direction of the photoconductor, and the calculation display unit calculates and displays the output signals of the plurality of light emitting / receiving elements.

[0014]

1 and 2 show an embodiment of the present invention. In this embodiment, a sensor for detecting the intensity of reflected light from the photosensitive drum in the circumferential direction of the photosensitive drum and a function for calculating and displaying an output signal of this sensor are provided in a photosensitive characteristic measuring device for the photosensitive drum. Is added. The photoconductor drum 11, which is used in an image forming apparatus such as an electrophotographic copying machine and whose photosensitive property and reflected light intensity are to be measured, is detachably mounted in this embodiment. Around the position where the photosensitive drum 11 is attached and detached, a charging unit 12, an exposure unit 13, a surface potential measuring probe 14 of a surface electrometer, a reflection type photo sensor 1 are provided.
5, the charge removing unit 16 is sequentially arranged along the rotation direction of the photosensitive drum 11. The charging unit 12 and the discharging unit 16 are provided corresponding to the entire length of the photosensitive drum 11, and charge and discharge the entire surface of the photosensitive drum 11, respectively.

The exposure unit 13 is composed of three exposure units 13a, 13b, 13c arranged in the axial direction of the photosensitive drum 11, and at the same time, it is possible to measure the photosensitive characteristics of the photosensitive drum 11 at three locations. These exposure parts 13a, 13b, 13
A laser light source is used for c, and shafts 17a and 17b are used.
Is supported so as to be freely movable in the axial direction of the photosensitive drum 11. The surface potential measuring probe 14 is the exposure unit 13.
Three surface potential measuring probes 14a arranged in the axial direction of the photoconductor drum 11 corresponding to a, 13b, 13c,
14b, 14c, and these surface potential measuring probes 14a, 14b, 14c are exposed portions 13a, 13b,
It is provided integrally with 13c.

The reflection type photo sensor 15 is provided with a light emitting / receiving element having a peak light emission wavelength of 940 nm, and is exposed in the conductive layer of the photoconductor drum 11 by exposing portions 13a, 13b, 1b.
The exposure unit 1 of the photosensitive drum 11 is provided corresponding to a position where light is emitted from 3c and a position outside the exposure width.
Light is irradiated to positions outside the exposure range of 3a, 13b, and 13c. This is from the photo sensor 15 to the photosensitive drum 1.
This is because the irradiation of light on No. 1 does not affect the characteristic evaluation of the photosensitive drum 11. The photosensitive drum 11 is rotationally driven by a photosensitive drum rotation driving motor 18. The photo sensor 15 has a peak emission wavelength 940 as shown in FIG.
The light emitting element 15a and the light receiving element 15b each have a wavelength of 0.1 nm and are combined with the resistors R ₁ and R ₂ and the variable resistor VR to form a detection circuit.

When measuring the photosensitivity of the photoconductor drum 11, the control unit 19 operates the motor 18, the charging unit 12 and the charge eliminating unit 16, and the photoconductor drum 11 is rotationally driven by the motor 18 to charge the charging unit 12. Are uniformly charged by. At this time, the exposure units 13a, 13b, 13c are not operating. The charging potential (dark potential) of the photoconductor drum 11 is measured at three points, that is, the central portion and both end sides, by the surface potential measuring probes 14a,
Measured by the surface electrometer via 4b and 14c, the control unit 19 fetches the measured values for one rotation (one rotation) of the photosensitive drum 11 and stores them in the memory.
The photoconductor drum 11 includes the surface potential measuring probes 14a, 1
After passing 4b and 14c, the charge is removed by the charge removing unit 16.

Next, the control circuit 19 operates the motor 18, the charging unit 12, the exposure units 13a, 13b, 13c, and the charge eliminating unit 16, and the photosensitive drum 11 is rotationally driven by the motor 18 so that the charging unit 12 can make it uniform. After being charged, the laser light is exposed by the exposure parts 13a, 13b, 13c, and the charging potential is lowered. The surface potential (bright potential) of the exposed portion of the photosensitive drum 11 is measured by the surface potential meter at the central portion and at three locations on both ends via the surface potential measuring probes 14a, 14b, 14c, and the control unit 19 controls them. The measured value of 1 is taken in for one rotation (one rotation) of the photosensitive drum 11 and stored in the memory. The photoconductor drum 11 is neutralized by the neutralization unit 16 after passing through the surface potential measuring probes 14a, 14b, 14c.

The control unit 19 graphs the dark potential and the bright potential of the three locations of the photosensitive drum 11 stored in the memory and displays them on the display unit 20, and displays the difference between the dark potential and the bright potential at each location. It is calculated, and it is judged whether or not these differences are within a predetermined range. If they are within a predetermined range, the display section 20 displays that the photosensitive characteristics of the photosensitive drum 11 are appropriate, and If the difference is not within the predetermined range at some point, the display section 20 displays that the photosensitive characteristic of the photosensitive drum 11 is not appropriate.

When measuring the photosensitivity of the photoconductor drum 11, the light emitting element 15a of the photosensor 15 emits a laser beam to the photoconductor drum 1 by a command LED from the controller 19.
Irradiate 1. The photoconductor drum 11 is provided with a photoconductive layer on a support, and the reflected light from the support and the reflected light from the photoconductive layer are received by the light receiving element 15b of the photosensor 15 and are received by the light receiving element 15b. The intensity of the flowing current changes depending on the intensity of the reflected light.

The current flowing through the light receiving element 15b is the resistance R
_The voltage of the resistance R ₂ is taken out by the control unit 19 for one rotation (one rotation) of the photosensitive drum 11 and stored in the memory.
The average value of the voltage for one cycle is calculated and displayed on the display unit 20. The output voltage of the photosensor 15 (voltage of the resistor R ₂ ) changes for one rotation of the photosensitive drum 11 as shown in FIG.
For example, the control unit 19 divides the output voltage of the photo sensor 15 into 30 equal parts for one rotation of the photosensitive drum 11, adds them, and then obtains an average value thereof to display on the display unit 20.

Light receiving / emitting elements 15a, 1 of the photo sensor 15
5b can be used as long as it is an element used for toner density control or jam detection of a copying machine. In this embodiment, ON2153GL manufactured by Matsushita was used. As the photosensor 15, a plurality of photosensors are arranged in the axial direction of the photoconductor drum 11 in order to measure variations in the intensity of the reflected light in the photoconductor drum 11 in the axial direction. Is measured at a plurality of different positions in the axial direction of the photoconductor drum 11, and the control unit 19 calculates the output signals of the plurality of photosensors in the same manner as described above and displays them on the display unit 20. Good. Further, not only the charging characteristic and the light attenuation characteristic of the photosensitive drum 11 but also the residual potential characteristic may be measured by the photosensitive characteristic measuring device of the photosensitive drum.

In this embodiment, when measuring the photosensitive characteristic of the photosensitive drum with the photosensitive characteristic measuring device of the photosensitive drum, the light reflection intensity of the photosensitive drum can be measured at the same time. Can be reduced and the inspection time of the photoconductor drum can be shortened.

[0024]

As described above, according to the first aspect of the present invention, the charging section for charging the photosensitive member, which is arranged around the position where the photosensitive member is attached and detached, and the exposure for exposing the photosensitive member Section, a charge removing section for removing charge from the photoconductor, and a surface potential measuring probe for measuring the surface potential of the photoconductor,
In a photoconductor characteristic evaluation device that rotates the photoconductor and evaluates the characteristic of the photoconductor by the measurement value by the surface potential measurement probe, irradiates light to a position outside the exposure range of the exposure unit of the photoconductor. Since a photoreceptive element for detecting the intensity of light reflected from the photoconductor in the rotational direction of the photoconductor and a calculation display section for computing and displaying an output signal of the photoreceptive element are provided, The light reflection intensity of the photoconductor can be measured at the same time when the photosensitivity is measured, and the photoconductor defect due to a handling error can be reduced and the photoconductor inspection time can be shortened.

According to the invention described in claim 2, in the photoconductor characteristic evaluation device according to claim 1, since a plurality of the light emitting and receiving elements are provided, the variation in the reflected light intensity in the axial direction of the photoconductor is measured. It becomes possible to do.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view of the same embodiment.

FIG. 3 is a circuit diagram showing a detection circuit of the same embodiment.

FIG. 4 is a waveform diagram showing an output waveform of the photo sensor in the example.

[Explanation of symbols]

 11 Photoreceptor Drum 12 Charging Section 13, 13a, 13b, 13c Exposure Section 14 Surface Potential Measuring Probe 15 Photosensor 16 Static Elimination Section 19 Control Section 20 Display Section

Claims (2)

[Claims] 1. A charging unit for charging the photosensitive member, a charging unit for exposing the photosensitive member, a charge removing unit for discharging the photosensitive member, and a photosensitive member arranged around a position where the photosensitive member is attached and detached. A photoconductor characteristic evaluation device having a surface potential measuring probe for measuring the surface potential of a body, wherein the photoconductor is rotated to evaluate the characteristic of the photoconductor by the value measured by the surface potential measuring probe, A light emitting / receiving element that irradiates light to a position outside the exposure range of the exposure unit on the body to detect the intensity of reflected light from the photoconductor in the rotation direction of the photoconductor, and an output signal of the light receiving / emitting element. A photoconductor characteristic evaluation device, comprising: a calculation display unit that calculates and displays. 2. A photoconductor characteristic evaluation apparatus according to claim 1, wherein the photoconductor characteristic evaluation apparatus is provided with a plurality of the light emitting and receiving elements.