JPS581163A - Image stabilizing method - Google Patents

Abstract

PURPOSE:To obtan invariably excellent and constant images even when images are formed continuously and repeatedly on a photoreceptor, by increasing the width of variation in light intensity or charging intensity according to image- formation halting time, and decreasing it a prescribed time later. CONSTITUTION:A pre-exposing means 11 performs exposure of a photoreceptor uniformly. A +7.0kV voltage is applied to a primary corona discharger 13 to charge the surface of the photoreceptor uniformly. Then, while the photoreceptor surface is exposed to an original optical image, a 6.5kV AC voltage is applied to a secondary corona discharger 15 to perform corona discharging. The photoreceptor surface is irradiated uniformly with light from an entire-surface exposing light source 16 to complete the image formation. An electromagnetic latent image is developed by, for example, sleep development. Then, a transferring material is superposed upon the developed image and said transfer corona discharger performs transfer corona discharging from the back surface. Then, the transferring material is separated after the transfer and then fixed by a fixing device which is not shown in the figure, thus taking a copy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention company, in charge of image stabilization, has discovered that it is possible to obtain a very good and constant jii image even when forming a #1 image on a photoreceptor. Image Carlson method, which allows
In electrophotographic methods such as the NP method, which performs image formation using -second charge, secondary charge at the same time as image exposure, and current@0 process, when the photosensitive plate is used repeatedly, the photosensitive plate becomes wJFIiAO. When image formation, subsequent image erasure, and pause dark battle O are performed, if an 0vjA image is not obtained at exactly the same level as the previous no#A image, that is, when image formation is repeated at a rapid rate, the conventional Nyogame Even if an image is formed in the process, the unsteadiness of the material is visible.%K, -As a failure of the quality, the memory phenomenon occurs when the first image is repeatedly formed and the m-formed image overlaps with the image copy. It was observed·
In addition, a phenomenon was observed in which the image quality between the two images was different, and the image quality was higher than that of the nine copies formed first and the large copies formed later.The latter point O is the surface potential. The value O indicates that the surface potential is low at the first copy and is in a region where it gradually increases. In the NP process, 11 cases were sometimes found when repeating within 3 seconds.

This difference in image quality becomes smaller as the machine is continuously rotated, but when the machine is stopped and then restarted, the difference in image quality becomes noticeable again.

The reason for this is that when the photoreceptor is used for high-speed printing, the photoreceptor has good photosensitivity, especially when the photoreceptor is 4.0. This is considered to be the result of the rapid accumulation of the charge exposure Mk of -f11 formation, which substantially increases the dark resistance of the photoreceptor.

If the continuous copy density gradually becomes lighter, use
On the other hand, the case where the 11th order becomes fainter is called ``Standing 1 attack''. Conventionally, as a method to correct the change in O potential during use of a ζO gun, it increases exponentially according to the rest time. With a correction amount, j! A document exposure regulator (hereinafter referred to as light adjustment) or a charging current adjustment means (hereinafter referred to as adjustment) which changes exponentially with respect to the number of copies is known.

However, with this method, only a constant 011 correction can be added; however, it is not possible to deal with fluctuations in the photoconductor O usage history and usage atmosphere, and if the correction amount does not match perfectly, the i5 phenomenon will occur. In other words, as the rest time of the photoreceptor increases, the rise width becomes larger, and after a certain time it becomes smaller. Therefore, in the simple '&-optical method,
Electrophotographic device OII! This resulted in a situation where it was difficult to maintain a constant continuous copying density because it was not possible to fully respond to the usage situation.

The reason why the rise-up phenomenon decreases at high temperatures is thought to be due to characteristic changes due to weak moisture absorption during long periods of rest of the photoconductor. Therefore, as a preventive measure, the photoconductor should be made to have a strong sound and a hazy shape. That is, applying electricity to the photoreceptor is considered, but heating tlL rice bran is not preferable since it increases the rise 9 phenomenon and accelerates the deterioration of the photoreceptor.

The present invention is based on the above-mentioned 0 points, and provides an image stabilization method that makes it possible to form continuous images in a good and constant manner.

The method of the present invention includes a lid for repeatedly forming images on a photoreceptor;
In the 100 million stabilization method in which the potential of the formed latent image is set to a predetermined value by changing the exposure intensity and/or the #i charging intensity that contribute to the electrostatic S image formation, the exposure intensity change is determined during the change in the charging intensity. 1- It is characterized in that it increases in accordance with the image forming body dwell time and decreases after a predetermined time has elapsed.

The details of the present invention will be explained below using specific examples with reference to the drawings. 1 is an electrophotographic apparatus based on the NP process described above, which has a surface insulating layer to form an image, and is supported in a rotational manner.A tungsten lamp serving as the preceding means is mounted on its circumferential surface. Static elimination @1 to eliminate O residual charges on the photoreceptor of light sources such as IIS
2 is first placed [with] then a primary coronal discharger 13 which applies a primary corona discharge for the formation of IIIgII, and a photoimage exposure 14, at the same time - next; Mu0ko4su discharge or -next and reverse polarity DO corona discharge or both combined 9-0 etc. secondary: 1osu discharger 1
5 and a full-surface exposure source 16 are arranged, and an aSS device 7 for developing the electrostatic latent image formed on the photoreceptor drum;
An O corona transfer discharge 818 is provided to transfer the OII particles to the transfer material 20, and a cleaning means 19 for removing the OII particles remaining on the photoreceptor after transfer is provided.

The original exposure means 14 is connected to a pongee 11 original exposure control means 30, which will be described in detail later.e The photoreceptor is made of aluminum and aluminum cylinder doped with -M, round cadmium sulfide, and #1*ri. The steps for obtaining an image using the above-mentioned apparatus are as follows:
It is.

First, the photoreceptor is exposed to light by the pre-exposure means 11.7.
OKV is applied to the primary corona discharge 913 to charge the narrow surface of the photoreceptor to -111 with the ψ-th μ, and the photoreceptor surface 1iIKjf
After the lightning image is exposed, a VO alternating voltage is applied to 45, and the discharger 15 performs co-off static elimination. Formation of the latent image is completed by emitting -am from iei.
For example, a sleeve II image is visualized. Then, a photographic material is superimposed on this filler image, and the transfer corona is applied from the back side with the transfer corona discharger.After the transfer is completed, the transfer # is separated and fixed with a fixing device (not shown) to provide a copy.Meanwhile, After the transfer is completed, the remaining image agent on the surface of the photoreceptor is removed by the cleaning means 19.

And ll on the photoreceptor! -The image shape is so powerful! By the way, the photoconductor'a Wio potential tends to rise when high-speed image reproduction is performed (Klj), and the performance rate increases as the number of copies increases, as mentioned above. It is. This tendency cannot be resolved by conventional single M# constant 0 light illumination or training.

This situation is shown in the jIz diagram! It shows the number of copies on the horizontal axis and the surface potential on the vertical axis @ dimming at opening,
30,000 sheets OII with a device that doesn't have 10 pieces! 20'0301 for shoes and shoes! When used in an environment of
As shown in Figure 3 (1), a large rise is caused by continuous copying in Sm with low humidity and low humidity. Differences in sand conditions are also important.Moreover, the length of the change, the amount of time it takes to start up, and the width of the start-up vary greatly depending on the downtime of the equipment and the body WOS vs. temperature.This is shown by I.
I3wA (-, if the temperature is low (one-point chain) K
During the start-up, Kt1ponm increases intermittently with the rest time, and in the case of a large wall saturation (as shown), it increases exponentially until the time, or after the O# point. On the contrary, it begins to decrease, and the long-time extraction K11l sums up. - In the case of high llO (indicated by the double-dashed line), the decreasing tendency becomes stronger on the long-term side. - Figure 3 C shows continuous copying after a 15-minute pause. The next type of dimming, IIIm method, consists of a single capacitor with a capacitance of 0 and a resistor. The lighting voltage and charging current of the exposure light source are changed by applying a DC voltage to the capacitor voltage and using the change in the capacitor voltage as a signal source.As the pause time increases, the amount of change changes exponentially. It is not possible to account for the decrease after a long time 114 and the decrease by direct control of the fl, and in continuous copying, the changes in the rockyness cannot be completely corrected. Even if there is a sudden attack indicating an attack, it will be corrected as described above.

Below, we will discuss the dimming/II4#1 means that uses the l1lO correction of the present invention.Specifically, the dimming/controlling #1 circuit, which exponentially increases and controls the conventional 10 The circuit that reduces the number of lights (hereinafter referred to as the dimming and dimming #1 circuit) will be used to achieve the desired result.

FIG. 4 (Ml is an f-diagram explaining the above-mentioned specific configuration. When the electrophotographic apparatus enters hibernation from time to, the hiatus timer TI starts operating, and the amount of light adjustment is determined by the voltage difference determining circuit 41. .Then, the voltage difference ΔVfo
(t) Kt! The photoreceptor covers the lighting voltage and is controlled! 1ljA
After the arrest of 91 people on Road 44, several electronic photographs were taken;
The exposure light 545m voltage is controlled during the beam.

Figure 114 (b) shows the differential voltage (magnetic layer) depending on the pause time.
and corrected dimming amount (與*) 0 characteristic diagram. When the pause threshold is longer than p% t1, the pause time timer T is activated. Voltage decrement is also 711V f, determined by nine-body stop time check.
(Customer) is multiplied by the correction number o) II number based on this 0*Km1 degree, and the value that becomes l/a・ΔVf, (t) is subtracted from the voltage difference mentioned above after time fl. become·
That is, the lighting voltage control circuit 44Wc receives a dimming amount signal of g-aVf, (t) first -ΔV fl(t).

1s4 (C) is a light control amount O characteristic diagram when it is 18 or more.

According to the above method, the amount of Omukai light increases with the rest time according to pIl&, and the lower the humidity, the larger the amount of O can be.Then, after a certain period of time, the amount of light control decreases, and the degree of decrease depends on the temperature. l
If j is high, it will be difficult to make Oshima large.This makes it possible to eliminate the potential change according to humidity shown in Figure 3.

In the above explanation, the timer T for the voltage difference determining circuit during the rest time, 0@tsumugi time t, and the timer T for voltage decrement determining circuit 1, 1011 time tl, are separate, but for practical purposes, they are different. -1 is relatively short < After 11, O is the double time and O changes, and both timers O - Tsumugi time are stopped at j1
Even if the salary is adjusted to 4i1, there is no problem with Oshima.

In the above sputum example, the case of dimming was explained, but it is of course possible to control to 4PJ411 in the case of regulating voltage I11 to control the electrostatic voltage.Also, it is possible to control dimming and flow regulation at the same time. It is also effective even if the configuration is as follows.As described above in detail with specific examples, the truth #1 is - Refreshing uniformity regardless of the image forming apparatus O standstill time and environmental changes -
An excellent companion that enables suitable a-image formation.

[Brief explanation of drawings]

Figure 1 is an example of an electrophotographic device O1 to which Honjitsu@ can be applied, 1
m2 diagram Hiro Characteristic diagram of changes in O receptor surface potential during continuous copying,
lKs diagram (a) II is O photoreceptor 1M during continuous copying! Nine characteristic diagrams that express the relative concentration as a parameter by changing the image potential O,
3(b) The dependence of the potential difference O body time during continuous copying is expressed as a relative degree of curvature parameter and expressed as 'C'.
(c) The figure is a analogy diagram showing the continuous copy potential difference O @ vs. temperature dependence after a 15-minute pause, lIi4wJ (aJU Book J [7j
iO# image stabilization method prick diagnosis 2m 01@@%li
J Figure 1b> shows that the pause time is a turtle.
Figure (c) shows a light control amount of 41I with a pause time of 11 or more. In the figure, 1: Photoreceptor 2^, 11: Pre-exposure means, 12: Static eliminator, 13 2nd stage electric device, 14: Photoimage exposure, 15
:Secondary corona discharge-116 two full surface exposure sources, 17 :ll
l-image scissors device

Claims (1)

[Scope of Claims] (1) The potential of the formed latent image is set by changing the liK of repeatedly forming an image on the photoreceptor, the exposure intensity contributing to electrostatic image formation, and/or the bud electric contrast t. In the image stabilization method, the exposure intensity or charging intensity is increased in accordance with the image forming body dwell time, and is decreased after a predetermined time has elapsed. method. (2341) In the invention described in claim 1, controlling the amount of increase in accordance with the signal of the temperature detection means is defined as 41 - Image stabilization method (3) Request for permission Kyoto III
! 1ts In the invention described in item 1, *41111 is that the amount of rise and decrease is controlled according to the signal of the humidity detection means.
1jfIA stabilization method. (4) An image stabilization method in which the 11 degree detection means is coated with a photoconductive substance in the 411 permission request 0m1lll item 2 or 0 shots described in item 3. .