JPS62156673A - Electrophotographic recording method - Google Patents

Abstract

PURPOSE:To improve the quality of printing without using a photosensitive body of high optical responsiveness by moving a photosensitive body and a recording medium with the same phase in the direction of deflection of a transfer roll electrode at the light irradiation time and the transfer time. CONSTITUTION:When a light beam 5 corresponding to picture/character information is projected to a photoconductive layer 1c from the side of a transparent supporting body 1a of a photosensitive body 1, an irradiated light part of the photoconductive layer 1c has conductivity partially, and an electric charge having the polarity opposite to that of a toner in a dark part, which is not irradiated, is charged to the toner in the light part from a transparent electrode 1b through the light part of the photoconductive layer 1c. An electrostatic force acts upon this toner 4, to which the electric charge having the opposite polarity is charged, from a transfer roll electrode 3 to transfer the toner to a recording paper 2. At this time, the center position of the transfer roll electrode 3 is deflected by a length (d) by which the recording paper 2 and the photosensitive body 1 are moved with the same phase. Thus, the toner is transferred to a correct position of the recording medium 2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrophotographic recording method used in copying machines, facsimile machines, optical printers, and the like.

(Prior Art) The applicant of the present application has previously proposed an electrophotographic recording method in which the number of steps is significantly reduced in Japanese Patent Application No. 1988-99369 (filed on May 10, 1985). In this method, charged toner is uniformly attached to the surface of the photoconductive layer of a photoconductor, which consists of a transparent support, a transparent electrode, and a photoconductive layer, and the photoconductor is irradiated with light from the transparent support side. The toner on the light irradiation part is transferred to the recording medium through a transfer electrode that faces the toner on the surface of the recording medium with the recording medium in between.

(Problems to be Solved by the Invention) In the electrophotographic recording method described above, the light irradiation position on the photoreceptor and the toner transfer position are opposite, and if the photoresponsiveness of the photoreceptor is poor, for example, the photoreceptor Photoresponse time is several dozen ~
If it takes several hundred milliseconds, it will take time for the toner to fly toward the recording paper after the photoreceptor is irradiated with light, resulting in the problem of image misalignment.

Therefore, an object of the present invention is to improve printing quality without using a highly photoresponsive photoreceptor.

(Means for Solving the Problems) A feature of the present invention is that the center of rotation of the transfer roller electrode is offset by a predetermined amount with respect to the light irradiation position on the photoreceptor, so that the rotation center of the transfer roller electrode is shifted by a predetermined amount with respect to the light irradiation position on the photoreceptor, and the photoreceptor and the recording The purpose is to move the medium and the transfer roller in the same phase in the direction of deflection of the transfer roller electrode.

(Function) By moving the photoreceptor and the recording medium in the same phase in the direction of deflection of the transfer roller electrode during light irradiation and transfer, the light irradiation part of the photoreceptor changes its relative position with the recording medium. Never. After a period of time corresponding to the photoresponsiveness of the photoconductor has elapsed, the light irradiation part of the photoreceptor reaches a position facing the transfer roller electrode, and the toner on the light irradiation part is transferred to the recording medium via the transfer roller electrode. Ru.

(Example) FIG. 1 shows a principle diagram of the electrophotographic recording method of the present invention. The photoreceptor 1 has a three-layer structure, in which a transparent electrode 1b is formed on the upper surface of a transparent support 1a such as glass, and a photoconductive layer 1c is formed on the upper surface of this transparent electrode. The transparent electrode 1b is biased to a negative potential by a power source E1, and light is irradiated from the transparent support 1a side. A recording paper, which is a recording medium 2, is conveyed facing the photoconductive layer IC. The charged toner 4 is deposited on the surface of the photoconductive layer 1c. A transfer roller electrode 3 is disposed on the back side of the recording paper 2, and is biased to a positive potential by a power source E1. The rotation center of the transfer roller electrode 3 is set at a predetermined ff with respect to the light irradiation position on the photoreceptor l.
It is biased by 1d. The photoreceptor 1 is designed to move in the direction of this deviation (in the direction of the arrow) in the same phase as the recording paper 2.

For example, when the photoconductive layer 1c is irradiated with a light beam 5 corresponding to image character information from the transparent support 1a side of the photoreceptor 1,
The bright part of the photoconductive layer IC that is irradiated with light partially exhibits conductivity, and the toner in this bright part is charged with the opposite polarity to that of the toner in the dark part that is not irradiated with light.
It is injected through the bright part of the photoconductive layer IC. An electrostatic force acts from the transfer roller electrode 3 on the toner 4 into which charges of opposite polarity are injected, and the toner 4 is transferred onto the recording paper 2. However, after the light beam 5 is irradiated onto the photoreceptor 1, the toner 4 is recorded. It takes time for the image to be transferred to the paper 2, depending on the photoresponsiveness of the photoreceptor. Therefore, the distance that recording paper 2 and photoreceptor 1 move in the same phase during this time! By shifting the center position of the transfer roller electrode 3 by d, even if the photoresponsiveness of the photoreceptor 1 is relatively poor, the toner is transferred to the correct position on the recording medium 2, and no image shift occurs.

FIG. 2 shows an example of an electrophotographic recording device based on the above principle. The first magnetic roller 6a and the second magnetic roller 6b, which are toner conveying means, have a large number of N and S magnetic poles alternately magnetized in the circumferential direction, and are rotatably provided.
Sleeves 7a and 7b are rotatably fitted to a and 6b, respectively.

A gap is provided between the sleeves 7a and 7b through which the light beam 5 can enter. A flexible photoreceptor 1 having a structure similar to that shown in FIG. 1 is attached to both sleeves.
In this example, both ends thereof are hooked around both sleeves 7a and 7b, and both ends are fixed to both sleeves. This photoreceptor 1 is provided upside down from that shown in FIG. 1, with an upper portion serving as a transparent support 1a facing both sleeves 7a and 7b, and a lower portion serving as a photoconductive layer IC. A toner container 8 is placed outside the photoreceptor 1.
is arranged. A toner charging electrode 9 is provided as a means for charging the toner 4. This toner charging electrode 9 is arranged below and in parallel with the photoconductive layer IC with a predetermined gap corresponding to the layer thickness of the toner, and both ends thereof are connected to the toner container 8. A slit 9a is provided in the toner charging electrode 9 at a position offset by a predetermined amount d from the position where the photoreceptor 1 is irradiated with the light beam 5, and the width of this slit 9a allows the transfer of toner onto the recording medium 2. Set the width to be as narrow as possible within the range you want.

A transfer roller electrode 3 is provided behind the recording paper 2, facing the slit 9a, and its rotation center is offset by a predetermined distance ff1d from the light irradiation position. The recording paper 2 is pressed against the transfer roller electrode 3 by the paper pressing plate 10 immediately before reaching the position facing the sleeve 1-9a. Paper press plate 1
0 is flexible in this example, and the recording paper 2 is brought into close contact with the transfer roller electrode 3 by applying tension. 1
1 is a pinch roller.

The third illustration shows another example of how the photoreceptor 1 is attached, in which the transparent support 1a is extended and the sleeves 7a and 7b are wound around it. The light 5 passes through the transparent support 1a located above and irradiates the photoreceptor 1 located below from the transparent support 1a side. In this way, there is no need to fix both ends of the photoreceptor 10 to both sleeves, making the installation easier.

The front beam 5 emitted from a light source (not shown) is reflected by optical scanning means such as a rotating polygon mirror 12a and an f.0 reflecting mirror 12b, passes through the gap between both sleeves 7a and 7b, and is exposed to light. The body 1 is optically scanned from the side of the transparent support 1a in a direction perpendicular to the conveyance direction of the recording paper 2.

During light irradiation and transfer, the first and second magnetic rollers 6
a, 6b are rotated clockwise, and both sleeves 7a,
7b is rotated counterclockwise. The photoreceptor 1 is moved from left to right in conjunction with both sleeves. Both magnetic rollers 6
Since the magnetic flux generated from a and 6b extends to the surface of the photoconductive layer 1c, as the magnetic field moves due to the rotation of both magnetic rollers, the toner 4 in the toner container 8 is transferred to the moving leading conductive layer lc. The surface is transported from left to right. The toner 4 is conveyed through the gap between the photoconductive layer IC and the toner charging electrode 9, so that its layer thickness is adjusted, and at the same time, charge is injected from the toner charging electrode 9. When the photoreceptor 1 is irradiated with light 5 from the side of the transparent support 1a at the light irradiation position, charges of opposite polarity are injected into the toner in the bright area according to the principle explained in FIG. 1, and the photoresponse of the photoreceptor 1 is increased. After a certain time delay depending on the color, an electrostatic force is applied from the transfer roller electrode 3 to the toner 4 charged to the opposite polarity in the bright area, and the toner 4 passes through the slit 9a.
The image passes through and is transferred onto the recording paper 2. During this transfer, since the photoreceptor 1 is moving in the same direction as the recording paper 2 as described above, the relative positional relationship between the two does not change and the image is transferred to the correct position. The untransferred toner 4 is subjected to sufficient magnetic force by the clockwise rotation of the magnetic roller 6b, and is sent from left to right as the magnetic field moves. In this way, the toner is supplied to the light irradiation section, and while the operation of transferring the toner continues and the recording of exactly one page is completed on the recording paper, the right end of the photoconductor 1 is connected to the right sleeve 7b. It moves from a position directly below to a position where its left end is directly below the left sleeve 7a.

Therefore, both magnetic rollers 6a, 6b and both sleeves 7a,
The direction of rotation of 7b is reversed, and now both magnetic rollers are rotated counterclockwise, both sleeves are rotated clockwise, and photoreceptor 1 is moved from right to left.

As a result, the toner 4 that has not been transferred is transported from right to left on the surface of the photoreceptor 1 that moves leftward, and returns to the toner container 8 . During this return operation, neither light irradiation nor toner transfer is performed.

(Effect of the invention) As described above, according to the present invention, the toner transfer position is deviated from the light irradiation position by the distance that the recording medium and the photoreceptor are transported during the time corresponding to the photoresponsiveness of the photoreceptor. Since the photoreceptor and the recording medium move in the same phase in this direction of deviation, no deviation of the toner images occurs. Further, even if the photoresponsiveness of the photoreceptor is somewhat inferior, an inexpensive and harmless photoreceptor can be used, which has the advantage of widening the range of selection.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view explaining the present invention in detail, FIG. 2 is a sectional view of a main part of an electrophotographic recording apparatus embodying the invention,
The figure is a sectional view showing another example of how the photoreceptor is attached. Technique: Photoreceptor, Ia: Transparent support, 1b.
...Transparent electrode, 1c...Photoconductive layer, 2...Recording medium, 3...Transfer roller electrode, 4...Toner, 5...Light. that's all

Claims (1)

[Scope of Claims] Charged toner is uniformly adhered to the surface of the photoconductive layer of a photoconductor consisting of a transparent support, a transparent electrode, and a photoconductive layer, and light is applied to the photoconductor from the side of the transparent support. In an electrophotographic recording method in which the toner on the light irradiation portion is transferred to the recording medium via a transfer roller electrode that faces the toner on the surface of the photoconductive layer with the recording medium interposed therebetween, the transfer roller The center of rotation of the electrode is shifted by a predetermined amount with respect to the light irradiation position on the photoreceptor, and the photoreceptor and the recording medium are kept in the same phase in the direction of deviation of the transfer roller electrode during the light irradiation and the transfer. An electronic photographic recording method characterized by moving the image.