JPH01133077A - Electrostatic recorder - Google Patents

Abstract

PURPOSE:To destaticize only the electrostatic charge region of a photosensitive body and to prevent generation of an optical memory by intermittently operating an erasing means in association to a charging means. CONSTITUTION:This recorder is equipped with the means for intermittently and electrostatically charging the continuously moving photosensitive body 20 by the charging means 22 and the means for intermittently operating the erasing means 11 in association to the operation of the charging means 22. The problem that the so-called optical memory is formed by irradiation of erasing light 11 even to the non-charging region of the photosensitive body 20 and that the uniform charging is not attained is thus prevented by destaticizing substantially only the charging region of the photosensitive body 20 by the erasing means 20.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to electrostatic recording devices such as quadruple copiers and printers, and is particularly characterized by erasing means.

[Conventional technology] In the conventional Iko copying machine, Yoneku used selenium, cadmium sulfide, etc. as a photoreceptor, but recently amorphous silicon (hereinafter referred to as a) has been used as a substitute for these photoreceptors. -31 for short.] has been attracting a lot of attention.

This A-8I photoreceptor is harmless to the human body and surpasses conventional photoreceptors in terms of photosensitivity, lifespan, heat resistance, etc.
When used with an L-length light source, it takes multiple charging currents to obtain the necessary surface potential for long periods of time on the exposed part (this phenomenon is called the pre-exposure effect). ].

The second (2) is the change in surface potential at the development position when selenium (Se) and A-8II are used as photoconductors in a conventional electronic copying machine, the voltage applied to the charger, and the static elimination light source (
3 is a graph showing the timing of lighting of the erase unit (erasing means).

If the diameter of the photosensitive drum is 906 mm, the circumference in one rotation will be approximately 283 mm, so when making a B4 copy (B4
The longitudinal direction is 364ffi) 1.3 rotations are required.

Therefore, conventionally, the static elimination light source starts lighting before the high voltage is turned on, and when copying several copies in a row.

The light went out a while after the last copy was completed.

-The high 4 voltage for charging is applied only when necessary when making multiple copies.9.

This is to prevent the adverse effects of Vc on the surrounding environment, as if the application time is long, the photoreceptor will become fatigued due to corona discharge and ozone will be generated. In such a sequence, when a Se drum is used as a photoreceptor, a stable surface potential can be obtained for a period equivalent to a B4 copy length. However, when an A-3I drum is used as the photoreceptor in this sequence, V unevenness occurs at the 14th position on the surface (see Figure 2).

The reason for this is thought to be that the IJ&-81 drum is more closely related to the light consideration of the static elimination light source and the surface position than the Se drum.

To clarify the previous 6 self phenomenon, a-81 drum 104
2 on the circumference of When examining changes in the surface potentials of gA and B, the results are shown in FIG.

The surface kt is measured after 1 rotation after planting.
See Figure 4]. Ideally, the surface leakage will be zero, and then it will be charged again.

△ The value at measurement point 103 of the surface temperature and the temperature immediately after the 1st test are shown in Table 1 above.

Margin table below 1 Here, A point d, A1, 400V is 6, A2 = A3 =
A4=500VK c, 8 points [B1=B3-400V
The reason for this is that when the charging corotron 101 is ON, the same current is always applied to the photoreceptor 104, but there are cases where it is OFF.

In other words, if the surface potential is 400 to 500V, it will be erased and become Ov, and the next time it will be charged, it will be 500VK.
However, in the case of Ov at first, even if it is erased again and then charged, the surface potential becomes a little lower.

This is thought to be because carriers generated by light are trapped in the film of the A-81 drum, canceling out the intense electric charge of the A-81 drum. As mentioned above, the conventional technology
Since the erase source is also irradiated to the non-i-electronic area of the photoreceptor,
This method has the problem that a so-called optical memory is not formed and is not uniformly charged.

The present invention has been developed in view of the drawbacks of the prior art, and is intended to prevent the generation of excess memory by erasing only substantially the charged area of the photoreceptor.

B) Means for Solving the Problems The invention is based on a photoreceptor that moves in one direction, a charging means that uniformly magnetizes the photoreceptor, and an exposure device that selectively exposes the charged photoreceptor to light. a developing means for developing an electrostatic latent image formed on the photoreceptor by the charging means and the exposure means with toner; a transfer means for transferring the toner image W=photographic paper; 2. A photoreceptor that is continuously moved by the band 1 means in an electrostatic recording apparatus equipped with an erasing means for erasing the image. This electrostatic recording device is characterized by comprising means for intermittently charging, and means for intermittently operating in conjunction with the operation of the MU write erase means and the charging means.

(Force action) In the present invention, since the erase means r and the charging means are operated intermittently in conjunction with each other, only the charged area of the photoreceptor is neutralized, and no one-dimensional memory occurs.

(f) Embodiment FIG. 5 shows a copying machine as an example of an electrostatic recording device to which this invention can be applied. FIG. In addition to such electronic copying machines, the present invention also applies to printers,
This method can be applied to all electrostatic recording devices, such as facsimile machines and other devices in which a photoconductive layer is charged and then exposed to light to form an electrostatic latent image on the photoconductive layer. I would like to point out in advance that this is the case.

First, this electronic copying machine will be briefly explained to the extent necessary for understanding the present invention. The four-child copying machine 1O is included in a machine body 12, and on the top surface of this machine body 12, a document table 14 on which a document (not shown) is placed is mounted.
1 or slidably provided. A slit is formed on the upper surface of the fuselage 12.

In connection with the slit, an original MW source light source 16, such as a halogen lamp, is permanently installed in the fuselage 12. A reflecting mirror having an elliptical cross section is provided in association with the light source 16, and the light from the light source 16 is reflected by this reflecting arm and placed on the document table 14. is irradiated. Therefore, as the document table 14 is moved in the direction of the arrow, the document receives and reflects the light r from the light source through the above-mentioned liner. The reflected light from the original, that is, the first stage of the original, is projected onto the photoreceptor drum 20 through the short focus lens array 18 fixedly provided on the lower blade of the slit. ! An image. This short focus lens array 18ilc is made of a focusing photoconductor in which a large number of Rondo lenses are closely arranged. It goes without saying that this short-focus lens array 18H may be used instead of other plastic lens arrays or ordinary convex lenses.

The photosensitive drum 20 is connected to the body 1 of this copying machine 10.
An n1 drive source (not shown) K arranged approximately in the center of the two circles rotates the document platen 14 in the clockwise direction Vc in synchronization with the movement of the document table 14.
Ru. Around the photoreceptor drum 20, there is a charging corotron 22, a developing device 24, and a paper feeding device 26.
, a transfer corotron 30, a separation corotron 32, a cleaning device 40, and an erase light source 11 as an erase means are arranged.

The FJ4 corotron 22 has an original fi on the photoreceptor drum 20.
1! Before the image is formed, the photoreceptor drum 20 is uniformly injected with a charge of positive polarity, and is connected to a DC high voltage power source (not shown). Sanru. When a document image is irradiated onto the photoreceptor drum 20 charged by the charging corotron 22 through the short focus lens array 18, a magnetostatic latent image is formed on the photoreceptor drum 20.

The developing device @ 24 is for developing such an electrostatic latent image formed on the photoreceptor drum 20 into a visible image using toner that is magnetized to a negative polarity, for example, and is a well-known method. This includes items such as toner boxes and magnetic brushes.

The paper feed device 26 has paper stacked in a paper feed cassette (not shown).
This is for bringing each of the nine sheets of paper 28 onto the surface of the photosensitive drum 20 one by one. For that purpose, paper feed ff? ! 12
6 includes a paper feed row 227 and a register roller 29. The paper feed roller 27 is rotated clockwise by a drive device (not shown).

It touches the surface and takes it in the direction of the nine paper 287 and the registration roller 29. The register roller 29 is a precise roller that feeds the paper that has been erected by the paper feed roller 27 toward the photosensitive drum 20 at an appropriate timing.

With this method, paper feeder n! The n paper fed from 26 is
While in contact with the surface of the photosensitive drum 200, the position of the transfer corotron 30 is reduced according to the rotation X of the photosensitive drum 20. The transfer corotron 30 generates a charge t having a polarity opposite to that of the toner in the developing device 24. Therefore, the toner forming a toner image r on the photosensitive drum 20 is transferred onto the paper 28 due to the illumination of the transfer corotron 30.

The separation corotron 32 separates the paper to be transferred onto the photoreceptor drum 20 during the above-mentioned transfer, and the photoreceptor drum 20.
For example, it consists of an AC corona discharger. The paper separated by the separation corotron 32 is transferred to a conveyor 3 provided on the downstream side in the conveyance direction.
It is further conveyed by 4.

This conveyor 34 includes a mesh-like endless belt driven by a drive (not shown) and a vacuum unit provided below the endless belt.Therefore, the paper is brought onto the mesh belt. It is sucked up by a vacuum unit, and as a result of the conveyance of the belt, it is conveyed to 360,000 feet.

Above the conveyor 34, there is a cleaning device f! related to the photoreceptor drum 20! 40 are provided.

This cleaning device 40 is provided to remove the toner image remaining on the photosensitive drum 20 after the toner image on the photosensitive drum 20 is transferred to paper. For that purpose, this cleaning device 40 cleans the photoreceptor drum 20.
0 Residual toner in contact with the surface? A blade for scraping off and a box to store the scraped toner? include. The erase light source 11 is the photosensitive drum 2
This reduces the residual position of 0.

The foot removal device 36 includes a heat roller having a built-in nausea heater, and a pressure roller for pressing the paper on which the toner image has been previously transferred against the /70 heat roller. Then, when the paper passes between these two rollers, the toner transferred onto the paper is melted by a separate heated roller.
The toner image is pushed into the tissue of the paper by the blade pressure roller, and the toner image is visible on the paper Vc. Thereafter, the paper 28 is ejected onto a paper ejection tray 38 by a paper ejection roller.

A control box 42 is provided within the aircraft body 12.

This control box 42 houses a printed circuit board (not shown) that houses the entire 4-air circuit for controlling the overall operation of the above-mentioned L system.

Further, a, *m unit 44 is housed in the lower part of the fuselage 12. This power source unit 44 includes electric power for a saw power source (not shown), for example, a motor. A ninth driving source is used to apply direct current pressure to the charging corotron 222L and the transfer corotron 30, and to a friend direct current high voltage source and separate corotron 32 to print high voltage τ. The AC high voltage source etc.

@5 In the L-shaped electronic copying device lO shown in Figure 5, the manuscript metalwork 4
When a document is placed on top of the machine spiral, the start button (not shown) is pressed, the document table 14 moves in the direction of the arrow, and the light image formed by the light source 16 passes through the short focal length lens array L8t'' to the photoreceptor. The photoreceptor drum 20 is irradiated onto the drum 20.
After the rotation of the photoreceptor drum 20 starts, at the timing to, an emission 4 from the corotron '2'Hc is started at the machine 9 shown in FIG. Therefore, by the time the corresponding portion of the photoreceptor drum 20 reaches directly below the short focus lens array 18, that portion has been charged with a predetermined weight by the charging corotron 22. After that, the above-mentioned process is started. 3, when the exposure is performed, an electrostatic latent image is formed on the exposed portion of the conductive layer 20b;
Therefore, as shown in FIG. 1(C), the timing t1
The developing device 24 is activated, and then the transfer corotron 30 and the separation corotron 32 begin to operate at timing tz, as shown in FIG.

In this embodiment, the erase light source 11 is a bright orange light emitting diode. I am using it.

Charging FJur:xslux''1 amount, band y after a band z
The part is 501ux and the unmagnetized part is 5/uX,
The light goes out immediately after the final charging is completed.

This formed realized image Q table rfJ center position is V
A uniform surface potential of 500 Vk could be obtained over the entire cB4.

As another example, the light intensity of the erase light source can change the egg pressure of the magnetic high pressure. That is,
Is it usually applied at a voltage of 6KV? If you apply 6.2 KV only when the surface 1 hits the part where the viewing position decreases,
The surface potential increases and surface potential unevenness disappears.

In addition, as the erase means, it is possible to use not only an erase source but also a corotron for weight removal or a conductive static eliminator 1227.

(Advantages and Effects of the Invention In the invention, since the erase means tg! is operated intermittently in conjunction with the erase means, only the charged area of the photoreceptor is neutralized, and n-source memory does not occur.

Therefore, even if a plurality of +1i1 silent latent images are formed on a photoreceptor that moves continuously by 1c, uneven magnetization will not occur, and a high quality document image can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a time chart showing the surface potential, etc. of the photoreceptor in an embodiment of the present invention, and FIGS. 2 and 3 are tables of the conventional example. FIG. 4 is a schematic diagram of the development of the display magnetic potential 11Qlj foot device, and FIG. 5 is a schematic four-fold diagram of an electronic copying machine in which the present invention is implemented. IO...Magnetic copying machine, 11...Erase source (erase means), 16...Document exposure light source, 18...Short focus lens array, 20...Photosensitive drum, 24...
Developing device, 30...transfer corotron.

Claims (1)

[Scope of Claims] 1. A photoconductor that moves in one direction, a charging device that uniformly charges the photoconductor, an exposure device that selectively exposes the charged photoconductor, and the charging device and the exposure device. A developing means for developing an electrostatic latent image formed on the photoreceptor by the means with toner, a transfer means for transferring the toner image onto a transfer paper, and an erase means for reducing the residual charge on the photoreceptor. The electrostatic recording device includes: means for intermittently charging a continuously moving photoreceptor by the charging means; and means for intermittently operating the erase means in conjunction with the operation of the charging means. An electrostatic recording device comprising: 2. The electrostatic recording device according to claim 1, wherein the erasing means is a light source selected from the group consisting of a tungsten lamp, a light emitting diode, a semiconductor laser, and a fluorescent glow tube. 3. The electrostatic recording device according to claim 1 or 2, wherein the photoreceptor is made of amorphous silicon or selenium arsenic.