JPS6035757A - Method for maintaining adequately electrophotographically copied image - Google Patents

Abstract

PURPOSE:To maintain copying conditions in an initial state by detecting the potential of the electrostatic latent image formed by a prescribed base line original, controlling quantity of electrostatic charge and exposure and controlling cleaning of an optical system. CONSTITUTION:A fine line part 6 consisting of fine black lines different from a wide-area black part 3 of a reference original 2 is provided to either the black part 3 or white part 4, i.e., the white part 4, etc. The potential of the electrostatic latent image formed on a photosensitive body 15 by the original 2 is detected by a surface potential detector 18. The quantity of charge, exposure and cleaning of stains in the optical system are controlled respectively by the surface potential of the latent image in the part 3, the surface potential of the latent image in the part 4, and the surface potential of the latent image in the part 6 via a measuring circuit 19, a comparator circuit 20, a control circuit 21, etc. The three conditions for copying are thus maintained always in the initial state and the adequate copying is accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for properly maintaining electrophotographic images.

- In general, the electrophotographic copying method consists of 7 steps on a photoreceptor: forming an electrostatic latent image by electricity and exposure, a developing step, a transfer step, a fixing step, a tarnishing step, and a static elimination step. Then, the copied image changes over time, and one of various optimum conditions may deviate due to changes in the ring 3fi, etc., resulting in a copied image of poor quality. Each −
Among the conditions of the J process, the most relevant is the electrostatic latent image forming process.

The present invention has been made in view of these points, and provides an electrophotographic image that maintains the electrostatic latent image in the most appropriate state to obtain a high quality copy image. The purpose of this study is to obtain a proper maintenance method for

The present invention relates to an electrophotographic method in which an electrostatic latent image is created on a photoreceptor through a charging process and an exposure process, and in which different black or white stripes are formed in either a wide black area or a wide white area of +i(). An electrostatic latent image is formed on the photoconductor 1- by a reference original consisting of a thin strip portion on which a It is characterized by maintaining an appropriate electrostatic latent image and producing an appropriate copy image by correcting the initial setting conditions.Therefore, the electrostatic latent image formed by the reference original is By detecting the potential of the black part of the latent image, excess or deficiency in the amount of charge can be detected, by detecting the potential of the white part, excess or deficiency in the amount of exposure can be detected, and by detecting the potential of the striped part, the optical It detects the presence or absence of contamination in the system, and is constructed so that proper image copying can be performed by always maintaining the three-stripe pattern in the initial state.

An embodiment of the present invention will be described with reference to the drawings. First, a contact glass (2) having a predetermined width and a predetermined length is provided, and a reference original 2 is provided at the end of this contact glass (I). The reflective surface of the standard original 2 includes a black part 3 with low reflectance and a large area, a white part 4 with high reflectance and a large area, and a strip part 6 formed by black stripes 5 formed in this white background. Become. Further, the contact glass 1
Various types of copy originals 7 are placed on the ``Y''.

At the bottom of the contact glass 1, there is a lamp 8 having a length longer than the width of the contact glass 1, a plurality of reflecting mirrors 9, 10, 11° 12, and a lens 13.
An optical system 14 is formed, and the round part of this optical system 14 is formed in the shape of a ram.

An exposed portion 16 is formed reaching the surface of the photoreceptor 15. A charger 17 is provided on the +)if and +'- side of this exposure section 16, and a surface for detecting the potential of the electrostatic latent image formed on the surface of the photoreceptor I5 is provided on the rear side. A potential detector 18 is provided. This surface potential detector 18 includes a tracing circuit 19, a comparison circuit 20, and a control circuit 21.
are connected sequentially.

However, the photoreceptor 15 is exposed to light reflected from the C1 standard original 2, and an electrostatic latent image is formed on its surface. The appropriate conditions for the potential of this electrostatic latent image are as shown by the solid line in Figure 2. In other words, the potential of the part corresponding to the black part 3 is high;
The potential of the portion corresponding to the white portion 4 is low, and the potential of the strip portion 6 is high, although not as high as that of the black portion 3. Therefore,
If the amount of exposure is insufficient, the overall potential increases as shown by the dotted line in Figure 2, and if the amount of charge is insufficient, the potential of the body increases as shown by the dotted line. It gets lower. In such a state, the measurement circuit 19 detects a predetermined electrical (if %
The comparison circuit 20 compares the signal with a reference signal corresponding to the initial condition, and the control circuit 21 provides a necessary control signal based on the result. That is, if only the exposure amount has changed, a signal for changing the lamp voltage or slit opening width is output, and these are automatically corrected or corrected display is performed.

Further, if only the amount of charge is insufficient, the voltage of the charger 17 is automatically increased or a display is made. Further, if both the exposure amount and the charge amount are fluctuating, it becomes a little complicated, but both can be corrected to appropriate values by correcting one or the other and copying several times.

Further, regarding the potential of the strip portion 6, there is a relationship as shown in FIG. That is, when the horizontal axis represents the concentration, specifically the Kodak clay scale density, and the vertical axis represents the photoreceptor surface potential, the exposure slit opening widths are 0°, 5°, 10°, 1
Regarding 5°, there is a relationship as shown in the figure for the optical system 14 before and after cleaning. Of course, cleaning the optical system 14
; ■ means that 40,000 to 50,000 copies have been made, and there may be toner or dust (;).

Therefore, when the concentration is high, the irregular length of the light 1 occurs due to the lIi deviation, and the 4th part becomes the flange V-light, which is 211i.
The potential of tf+1n1f is low, and the potential after cleaning is high. Furthermore, when the 'a degree is low, the number of leading claws decreases due to dirt, so the potential is high before cleaning and becomes low after cleaning. therefore.

A reference potential is determined depending on whether black or white is used for the striped portion 6, and dirt on the optical system 14 is detected by fluctuations in the potential. Depending on the result, a message is displayed to automatically clean or clean the optical system 14.

In addition, when detecting the potential of each part using Standard Original 2, if the photoreceptor 15 material has a large residual potential change, such as zinc oxide or organic photoconductor (0111C), detection is performed once each time each copy is made. It is desirable to have automatic detection by growling. In addition, if the photoreceptor 15 is made of a material such as Ss, which has a small residual potential change, an electrostatic latent image due to the reference original 2 will not be formed under normal conditions, and a proper maintenance operation switch operated during regular maintenance by a service person can be used. It is also possible to provide the reference original 2 and perform the detection using the reference original 2 only in that case. In this case, the reference original 2 may be placed inside the main body or may be placed on the contact glass 1.

Further, when the reference original 2 is provided in one main body, the lamp 8 may have a large overall length, and the reference original 2 may be always placed on the side of the contactor 1 and the glass 1.

In addition, when using a photoreceptor 15 made of Se or the like with less fatigue phenomenon, the main purpose is to correct the initially set charge amount and exposure amount as described above, and to correct changes over time. By detecting the potential of the electrostatic latent image revealed on the reference original 2 each time copying is performed, the amount of light from the lamp 8 due to fluctuations in the input terminals is detected, and the amount of light from the lamp 8 due to fluctuations in the input terminals and the amount of charge by the charger 17 are determined. A function is added to correct fluctuations, such as fluctuations in charge groups due to environmental changes. Furthermore, in addition to the above-mentioned functions, in addition to the above-mentioned functions, when using photoreceptor I5 made of zinc oxide or an organic photoconductor, which has a large fatigue phenomenon, or when performing high-speed r-geation, the bright and dark charging potentials should be kept constant. By doing so, it has the function of preventing the phenomenon of Jt multiplied by 1-fatigue.

The present invention has a black part, a white part, ll(1
Electrostatic M f&t by reference original with single thread section
& is formed, and by setting the potential of this electrostatic m image Jll+, the exposure amount, charging light, and flare light state can be detected. This has the effect that a close-up image with an appropriate i1 value can be obtained by setting the initial setting conditions.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention. FIG. 11 is a side view, FIG. 2 is a characteristic diagram showing the relationship between the reference original and the latent image potential of the photoreceptor, and FIG. 3 is a diagram showing the optical system after Wll. This is a characteristic 181 showing the relationship between density and photoreceptor surface potential. , Kishikiso original, 3. Black part, 4 White part, 6
- Strip section, 14... Optical system, 15 Photoconductor procedural amendment (master) May 18, 1980 Director-General of the Patent Office Kazuo Wakasugi 2 Name of invention Address Nakamagome, U-ku, Tokyo 1-3-6-4, Agent 107 Address 5-9-15 Minami-Aoyama, Minato-ku, Tokyo None Patent Application No. 80708 Supplementary IR - Regarding this application, the statement in the specification is as above. Correct to. Note 1, page 1, line 3
2. 1st L'J: Claims from lines 4 to 14 are changed to 111. Correct it like paper. , 3. Correct the first line of the first line of CL [suitable 11-textile 1-1 method] to "suitable iE textile L!I'M device". 4. 2nd c (9th line r suitable i [2 maintenance method J &
r all:. Correct to maintenance device 1ffi J. 5, page 2, line 11 to page 1, page 8 'I'j
l] delete the sentence. 6. Add the following sentence to the 6th line of page 5. [That is, a lower stage for controlling the exposure amount and a stage for indicating whether or not to expose the light are provided. ” 7. Add the next sentence after “A demonstration will be made” in the 9th line of the 5th Q. "In other words, a charge amount control means and a charge amount display means are provided." 8. Add the following sentence to the 12th line of page 6. "In other words, a cleaning means and a cleaning display means are provided." 9. The sentence on page 8, lines 5 to 11 is corrected as follows. ``The present invention forms an electrostatic latent image on a photoreceptor using a reference original having a black part, a white part, and a striped part as described above, and measures the surface potential of this electrostatic latent using a surface potential detector. Detecting the surface potential corresponding to the black part, the white part, and the striped part, the charge amount control means, the exposure amount control means, the clear 1fi1 hair step, and the exposure amount are maintained appropriately; It is possible to eliminate the influence of dirt on the optical system, and it is also possible to know what needs to be adjusted using each display means.''10, page 8, line 19 [, 18. Add "Surface Potential Detector". Attachment 2, Particular; '1 Claims - Maki ----

Claims (1)

[Claims] In electrophotography, which creates an electrostatic latent image on a photoreceptor through a charging process and an exposure process, a strip in which different black or white stripes are formed in either a wide black area or a wide mountain area. An electrostatic latent image is formed on the photoreceptor using a reference original consisting of parts, and the potential of each part of this electrostatic latent image is detected to correct the charge amount, exposure amount, and flamer light to initial setting conditions. A method for properly maintaining an electrophotographic copy image, characterized in that a proper electrostatic latent image is maintained to obtain a proper copy image.