JPS6120080A - Abnormality detecting device for electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To use the abnormality detecting device effectively for inspection of a photosensitive body, detection of abnormality occurrence during use, etc., and to improve the reliability of the electrophotographic sensitive body by providing a light emitting element and a photodetecting element which emit and detect light at a short-wavelength side and light at a long-wavelength side about the light absorption terminal of the photosensitive layer of the objective photosensitive body. CONSTITUTION:A light emitting and photodetecting photosensor 1 which emit and photodetect short-wavelength light and long-wavelength light below and above the 600nm light absorption terminal of an Se/Te photosensitive layer is fixed to a movable body 2 and faces the photosensitive body 3 to be detected. This photosensor 1 is supplied with electric power from a power source 4 to irradiate the surface of the photosensitive body 3 with light from the light emission part and its reflected light is converted by the photodetection part of the photosensor 1 into an electric signal, which is read by a recorder 6 through an amplifier 6. The photosensor 1 moves to irradiate the entire surface of the photosensitive body 3 and photodetects the reflected light, or to irradiate the periphery of a place corresponding to a defect part in a formed image and photodetect the reflected light. Thus, the photosensor 1 emits light of principally 400-600nm wavelength and photodetects light reflected by the surface of the photosensitive body, and an abnormal part and a normal part in the surface of the photosensitive body 3 are compared with each other.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention promptly detects abnormalities that cause image defects in the electrophotographic process, and detects abnormalities in electrophotographic photoreceptors that can be used as data for removing or replacing defective photoreceptors or improving the photoreceptor manufacturing process. Regarding equipment.

[Prior art and its problems]

The causes of image defects in the electrophotographic process are:
These abnormalities are caused by scratches on the surface of the photoreceptor, adhesion of foreign matter, or crystallization or abnormal composition on the surface of the photoreceptor and at the interface between the conductive substrate and the photosensitive layer during the long-term image forming process. Conventional methods for detecting failure of these photoreceptors include the following methods. (1) Form an image and determine whether it is normal or abnormal based on its quality. However, there are a wide variety of causes for defects on images, and there are often cases in which the determination of normality or abnormality is incorrect. (2) Crystal inspection is performed by X-ray diffraction; however, this method is a destructive inspection, and the equipment itself is large and very effective. (3) Analyze using an optical microscope. However, in this case as well, the photoreceptor must be destroyed in order to analyze the interface abnormality, and a skilled technician is required.

[Purpose of the invention]

The present invention provides an electrophotographic photoreceptor that can accurately detect defects on the surface and inside of the photoreceptor without destroying the photoreceptor, and is compact and can be used while attached to a copying machine, etc. The present invention relates to an abnormality detection device.

[Key points of the invention]

Among the abnormalities that cause image defects, the present invention eliminates scratches and foreign matter adhesion on the photoreceptor surface by reducing the diffuse reflection of short wavelength light below the light absorption edge of the photosensitive layer on the surface. Or abnormal parts such as crystallized parts existing at the interface with the substrate,
It detects by reducing the reflected light of long wavelength light above the light absorption edge of the photosensitive layer, and is equipped with a light-emitting element, a light-receiving element, and a means for detecting the output of the light-receiving element, which can be mounted opposite to the photoreceptor. The above purpose is achieved by an abnormality detection device in which each of the light receiving elements is capable of irradiating and sensing short wavelength light below the light absorption edge of the photosensitive layer of the photoconductor to be tested and long wavelength light above the light absorption edge. .

[Embodiments of the invention]

FIG. 1 shows an embodiment of the present invention, for example, Se/
Short wavelength light with a light absorption edge of 600 Ru or less of the Te-based photosensitive layer and 6
A commercially available light emitting/receiving photosensor 1 that emits and receives long wavelength light of 0.001%11 or more is fixed to a movable support 2 and is positioned facing a photoreceptor 3 to be tested. Electric power is supplied to the light emitting/receiving photosensor 1 from the electric fi4, and light is irradiated onto the surface of the photoreceptor 3 from the light emitting section. The reflected light is converted into an electrical signal by the light receiving section of the photosensor 1, and read by the recorder 6 via the amplifier 5. The photosensor 1 moves to irradiate and receive light over the entire surface of the photoreceptor 3, or to irradiate and receive light around a portion corresponding to a defective portion of the formed image. Figure 2 shows a comparison of the abnormal and normal areas on the surface of the photoreceptor 3 by irradiating light with a wavelength of 400 to 600 nm as a main component using the photosensor 1 and receiving the light reflected on the surface of the photoreceptor 3. The sensor output 21 in the abnormal area clearly shows a lower value than the sensor output 22 in the normal area. In FIG. When irradiating light with a wavelength of 800 nm as a main component and receiving light mainly reflected at the interface between the photosensitive layer of the photoreceptor 3 and the substrate, the abnormal area (interface crystal area) becomes a normal area 32 due to a decrease in reflected light. Lower electrical signal level 3
1 is shown. Figure 4 shows another example in which two types of photosensors that emit light with a wavelength lower than the absorption edge of the photosensitive layer and light with a wavelength higher than the absorption edge of the photosensitive layer are used for simultaneous irradiation, and the output is generated by the reflected light from the surface of the photosensitive member. This is an example in which both outputs 41 and 42 due to reflected light from the interface are detected, and an abnormality can be found in each.

【Effect of the invention】

According to the present invention, a light emitting element and a light receiving element capable of irradiating and detecting light on the short wavelength side and light on the long wavelength side with respect to the light absorption edge of the photosensitive layer of the photoreceptor to be tested are provided, and an abnormality in the output of the light receiving element is provided. This method detects defects such as scratches, foreign matter adhesion, crystallization 1 composition abnormalities, etc. that exist on the surface of the photosensitive layer and the interface with the substrate.It is non-destructive and can be performed at low cost, so it is used to inspect photoreceptors. It can be effectively used to detect the occurrence of abnormalities during use, and has a great effect on improving the reliability of electrophotographic photoreceptors.

[Brief explanation of drawings]

FIG. 1 is a layout diagram conceptually showing the usage state of an abnormality detection device according to an embodiment of the present invention, and FIGS. 2 to 4 are photosensors showing respective abnormal parts obtained by the abnormality detection device according to the present invention. It is an output recording diagram.

Claims (1)

[Claims] 1) Equipped with a light-emitting element, a light-receiving element, and a means for detecting the output of the light-receiving element, which can be mounted opposite to the photoreceptor to be tested;
For electrophotography, the light-emitting element and the light-receiving element are capable of respectively irradiating and sensing short-wavelength light below the light absorption edge of the photosensitive layer of the photoreceptor to be tested and long-wavelength light above the light absorption edge. Photoconductor abnormality detection device.