JPS59226830A - Measuring device of light sensitivity distribution - Google Patents

Abstract

PURPOSE:To measure a light sensitivity distribution with high precision by providing a single light source as an exposure light source, an optical waveguide arranged between the light source and the surface of a photosensitive body, and a means which projects light guided through the optical waveguide upon plural positions on the surface of the photosensitive body. CONSTITUTION:Light from the single light emission source 4 which is close to a spot light source is guided through the plural optical waveguides 5 to the photosensitive body 1 to be measured, which is exposed to it. Multicore optical fiber is used as the optical waveguides 5. An optical system 8 allows the light from the light source 4 to enter the optical waveguides 5, and an optical systems 9 diverges the output light beams from the optical waveguide 5 so as to obtain necessary spread on the photosensitive body. Consequently, plural objective points of measurement are exposed by using the single light emission source, and even if the optical waveguides 5 have variance in optical waveguide characteristics, adjustments are made once by the optical systems 9 to eliminate the change with lapse of time of the light source and the need for readjustment at light source replacement.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for measuring the photosensitivity distribution on the surface of a photoreceptor having a certain extent.

[Prior art and its problems]

For example, in order to evaluate the electrophotographic characteristics of an electrophotographic photoreceptor used in an electrostatic copying machine or printer, the sensitivity distribution and the like on the surface of one photoreceptor are measured. Specifically, the photoreceptor is charged with a corona discharger, etc., and then the surface potential of multiple parts of the photoreceptor is measured after or while being exposed to an appropriate amount of light, and the amount of change in surface potential due to exposure is measured. to detect light sensitivity. Conventionally, a plurality of exposure sources of such a photosensitivity measuring apparatus are arranged facing a photoreceptor 1 as shown in FIG. The exposure amount of each exposure source 2 is adjusted using an ND filter or the like so that the exposure amount at each exposure section is made uniform. However, since an independent light source is used, there is a limit in accuracy.

Furthermore, maintenance costs such as readjustment due to changes in the light source or replacement of the light source increase. FIG. 2 shows another apparatus in which the surface of the photoreceptor 1 is simultaneously exposed to one exposure source 3, and the amount of change in surface potential of each portion after exposure is measured while scanning in the length direction. As the exposure source 3, a light source having a length approximately equal to the distance between the photoreceptors 1 to be measured is used. The non-uniformity of the brightness of the light source itself is
The shape or N of the slit placed between the light source and the photoreceptor
It is adjusted using a D filter, etc. However, light source 3
There is a limit to accuracy when adjusting the entire length of the
This requires maintenance work such as readjustment due to changes in light distribution due to changes in the light source over time and readjustment when replacing the light source.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and provide a photosensitivity distribution measuring device having an exposure source that is more accurate and easier to maintain.

[Key points of the invention]

The present invention uses a single light source as an exposure source for a photosensitivity distribution measuring device, an optical waveguide disposed between the light source and the surface of a photoreceptor, and a plurality of light guides on the surface of the photoreceptor. The above object is achieved by comprising a means for projecting onto the site. As such means, it is effective to use a plurality of optical waveguides or to move the tip of the optical waveguide along the surface of the photoreceptor.

[Embodiments of the invention]

Embodiment 1: As shown in FIG. 3, light is guided from a single light emitting source 4 close to a point light source onto the photoreceptor 1 to be measured through a plurality of optical waveguides 5 for exposure. As the optical waveguide 5, it is preferable to use a multi-core optical fiber. The optical system 8 is used to make the light from the light source 4 enter the waveguide 5, and the optical system 9 is used to spread the output light from the waveguide 5 and provide necessary and sufficient spread on the photoreceptor. I'll go. It is also possible to provide a slit or the like inside the optical system 9 to arbitrarily change the shape of the exposed portion. With this method, multiple measurement points can be exposed using a single light emitting source, and even if there is a difference in the light guiding characteristics between the optical waveguides 5, the optical system 9 can adjust them once. Embodiment 2: As shown in FIG. 4, the optical waveguide 5 in FIG. 3 is replaced with one, and the optical waveguide 5 in FIG. The optical system 9 at the tip can be moved to expose the surface of the photoreceptor 1 while scanning it. In this case, there is no need for adjustment at all except for changing the exposure conditions, so handling is extremely simple. [Effects of the Invention] According to the present invention, as described above, since the exposure source is composed of a single light emitting source, By exposing multiple parts through multiple optical waveguides or by exposing multiple parts while moving the tip of the optical waveguide, the amount of exposure to multiple parts to be measured is made uniform, resulting in highly accurate photosensitivity. It becomes possible to measure the distribution. Furthermore, by using a single light source, exposure conditions can be easily changed, and there is no need to adjust or readjust the light distribution, reducing maintenance costs. Furthermore, by using a guiding waveguide, the light emitting source can be placed away from the photoreceptor to be measured, so even if the temperature of the light emitting source is high, the temperature of the photoreceptor does not rise, and unlike selenium photoreceptors, It can be used with confidence even when measuring photoreceptors whose photosensitivity changes depending on temperature.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing two examples of exposure sources of a conventional photosensitivity distribution measuring device. FIG. 3 is a cross-sectional view showing an exposure source of an embodiment of the present invention. FIG. 3 is a cross-sectional view showing an exposure source of the embodiment. 1... Photoreceptor to be measured, 4... Light emitting source, 5 - Optical waveguide, 8.9... Optical system.

Claims (1)

[Scope of Claims] 1) A device for measuring the amount of variation in the charged potential of a plurality of parts on the surface of a photoconductor due to exposure, which includes a single light source as an exposure source and a light guide disposed between the light source and the surface of the photoconductor. A photosensitivity distribution measuring device comprising a waveguide and means for projecting light guided by the optical waveguide onto a plurality of locations on the surface of a photoreceptor. 2. A photosensitivity distribution measuring device according to claim 1, wherein the means for projecting light onto a plurality of locations on the surface of the photoreceptor is a plurality of optical waveguides. 3) The device according to claim 1, characterized in that the means for projecting light onto a plurality of parts on the surface of the photoreceptor is a device that moves the tip of the optical waveguide along the surface of the photoreceptor. Light sensitivity distribution measuring device.