JPH0289070A - Electrophotographic recorder - Google Patents

Abstract

PURPOSE:To prevent disturbance of a toner image to record an image of high quality by providing a fourth electrode kept at a fourth potential so that the toner image which is formed on a first supporting body and/or a photosensitive layer and is positively or negatively electrified at the time of movement of a recording medium is attracted to the recording medium. CONSTITUTION:When development is terminated, a positively or negatively electrified toner image 28b is electrically attracted to a recording medium 1 by a fourth electrode 29 kept at a fourth potential V4 though the recording medium 1 is moved by a moving means 5. When a second supporting body 22 and a third electrode 26 consist of a magnet roll, the fourth electrode 29 and the fourth potential V4 are so set that the toner image 28b is not pulled back to the magnet roll by the magnetic force. Since electric charge 3a which has the polarity opposite to that of electric charge of a toner image 28c positively or negatively electrified by an electrifying means 3 is formed on the rear face of the recording medium 1 which passed a developing means 2, the toner image 28c is attracted to the recording medium 1 by the Coulomb's force acting between both of these electric charge. Thus, the toner image is not disturbed to record the image of high quality.

Description

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

[Prior Art] As electrophotographic recording devices, those using the so-called Carlson process have been widely put into practical use, but in recent years, devices having recording principles different from the Carlson process have also been studied.

As a recording method using the non-Carlson process, for example, there is a method described in Japanese Patent Application No. 161307/1983.

This recording method will be explained below.

In FIG. 5, 21 is a first support having translucency;
22 is a second support placed opposite to this first support, 23 is a transparent first electrode formed on the first support, and 24 is this first electrode. 23 a photosensitive layer formed on the photosensitive layer 24; 25 a second electrode partially formed on the photosensitive layer 24; 26 a third electrode formed on the second support 22; 27 a light source. The above components constitute the developing means. 1 is the first support 21
and a recording medium 30 installed between the second support 22 and the second support 22.
toner 28 is a toner image formed on the recording medium 1 by the flying toner 30.

Note that the first electrode 23, the second electrode 25, and the third electrode 26 are maintained at a first potential vl1, a second potential v2, and a third potential v3, respectively.

Figure (a) shows the state when no light is irradiated (hereinafter referred to as dark time).

A portion of the photosensitive layer 24 where the second electrode 25 is not formed (
Hereinafter, it will be referred to as the surface of the photosensitive layer. ), if we consider the resistance of
As shown in the figure, the resistance component of the photosensitive layer 24 can be divided into resistance Rvd in the stacking direction and surface resistance Rsd. Photosensitive layer 2
4, the resistivity, film thickness, and distance of the portion where the second electrode 25 is not formed are appropriately selected to be Rvd) Rsd, then the surface potential of the surface of the photosensitive layer 24 is approximately that of the second electrode. It becomes equal to the potential v2 of 25. Therefore, by appropriately selecting the values of v2 and v3, the electric field generated by the potential difference (=lV3-V21) between the potential v3 of the third electrode 26 and the above-mentioned surface potential (=V2) is set to a predetermined electric field or less, and the above-mentioned electric field The Coulomb force acting on the toner 30 due to
If the adhesion force with the electrode 26 is made larger,
Toner 30 does not fly out.

Figure (b) shows when light is irradiated (hereinafter referred to as brightness).
This shows the state of

When light from the light source 27 is irradiated from the back side of the first support 21 to a portion of the photosensitive layer 24 where the second electrode 25 is not formed, photocarriers are generated in this portion of the photosensitive layer 24. Therefore, the resistance value in the stacking direction decreases to Rvp. −
The value Rsp of the blade surface resistance hardly changes. That is, it can be considered that Rvp (Rvd%R8p, = Rsd).If the resistivity of the photosensitive layer 24 at the time of light irradiation is an appropriate value, it can be set as Rvp (Rsp, and in this case, the surface of the photosensitive layer 24 The potential is approximately the potential v of the first electrode 23
becomes equal to 1. Therefore, by appropriately selecting the value of vl,
Potential v3 of the third electrode 26 and the above surface potential (, Vl)
If the electric field generated by the potential difference (zIV3-VL l) between , the toner 30 leaves the third electrode 26 and flies toward the recording medium 1, forming a toner image 28 on the recording medium 1.

A toner image is formed (developed) on a recording medium by the recording method described in Conventional Example 1 above.

After development is completed, the recording medium is moved to perform the next recording.
A toner image will be formed at a new location on the recording medium. That is, development and movement of the recording medium are alternately repeated, and a desired recording pattern is formed on the recording medium.

[Problems to be Solved] In conventional electrophotographic recording devices, toner is held on the recording medium only by the adhesive force acting between the toner and the recording medium.

Therefore, the toner image separates from the recording medium or moves around on the recording medium due to vibrations caused by the movement of the recording medium, and the toner image is disturbed, making it impossible to perform high-quality recording.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide an electrophotographic recording apparatus that can perform high-quality recording without disturbing toner images.

[Means for Solving the Problems] The present invention includes a first support having translucency, a second support disposed opposite to the first support, and the first support.
a translucent first electrode formed on the surface of the support facing the second support and held at a first potential; and on the first support including the first electrode. a second electrode partially formed on the photosensitive layer and held at a second potential; and a surface of the second support facing the first support. a third electrode formed at a third potential and held at a third potential;
a light source that irradiates light to a portion of the photosensitive layer where no electrode is formed to change the surface potential of the photosensitive layer in the irradiated portion; and the changed surface potential of the photosensitive layer and the third electrode. A recording medium to which the charged toner flying from the charging electrode is attached due to a Coulomb force generated by a potential difference between the electric potential of The above object is achieved by an electrophotographic recording apparatus having a fourth electrode held at a fourth potential so as to attract the adhered toner to the recording medium.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

Embodiment 1 FIG. 1 shows a first embodiment of the present invention.

In the figure, 1 is a movable recording medium made of insulating plastic (polyester, polyimide, mylar, etc.). 2 is a developing means, which consists of a first support 21 having a light-transmitting property, a second support 22 placed opposite to the first support 21, and the first support 21. 21
A transparent first electrode 23 formed above, a photosensitive layer 24 formed on this first electrode 23, a second electrode 25 partially formed on this photosensitive layer 24, and a second electrode 25 formed partially on this photosensitive layer 24. In this example, as the second support 22 and the third electrode 26, a mag roller having conductivity and magnetism is used. is used. A fourth electrode 29 is formed on the photosensitive layer 24, but it may also be formed on the first support 21 and/or the photosensitive layer 24.

3o is toner (magnetic toner in this example) deposited on the magnetic roller. 28a, 28b, and 28c are toner images that are positively or negatively charged (positively charged in this example) formed on the surface of the recording medium 1 by the flying toner 30. Charging means 3 charges the back surface of the recording medium 1 to a polarity opposite to that of the pressure or negatively charged toner image, and is constituted by a corona charging device, a frictional charging device, or the like.

Note that the first electrode 23, the second electrode 25, and the third electrode 2
6 and the fourth electrode 29 are maintained at a first potential v11, a second potential v2, a third potential v8, and a fourth potential v4, respectively.

As can be seen from the figure, the method of forming (developing) a toner image is the same as that of Conventional Example 2 described above.

When the development is completed, the recording medium 1 is moved by the moving means 5, but at this time the toner images 28b and 28c are held on the recording medium 1 as shown below.

First, the toner image 28b above the fourth electrode 29 will be described.

Toner image 2 that is positively or negatively charged (positively charged in this example)
8b has a fourth electrode 29 maintained at a fourth potential v4 so as to electrically attract the toner image 28b, so that the image is not disturbed.

At this time, it is important to set the fourth electrode 29 and the fourth potential v4 so as to prevent the toner from flying during development or from flying during non-development. Further, when the second support body 22 and the third electrode 26 are composed of magnetic rollers as in this example, the toner image 2
It is important to set the fourth electrode 29 and the fourth potential v4 so that the magnet 8b is not pulled back to the mag roller by magnetic force.

Next, the toner image 2JIC after passing through the developing means 2 will be explained.

On the back surface of the recording medium 1, a charge 3a having a polarity opposite to that of the toner image 28c (positively charged in this example) that is positively or negatively charged (positively charged in this example) by the charging means 3 is formed. Toner image 2 is created by the Coulomb force acting between these two charges.
8c is attracted to the recording medium 1, and the image is not disturbed.

As described above, the toner images 28b and 28c held on the recording medium by the fourth electrode 29 and the charging means 3 are
The image is conveyed without being disturbed, and the transferred toner image 28d is transferred onto the transfer object 7 (recording paper, etc.) by the transfer means 6.

Embodiment 2 FIG. 2 shows a second embodiment of the present invention.

In this example, in order to hold the toner image 28c after passing through the developing means 2 on the recording medium 1, a holding electrode 4 kept at the fifth potential is provided, and other matters are the same as in the first above. This is similar to the example. Therefore, the same parts as in the first embodiment are indicated by the same symbols and numbers.

The holding electrode 4 is installed on the back side of the recording medium 1, in contact with the recording medium 1, or with a slight gap from the recording medium 1. Further, the holding electrode 4 is held at a predetermined potential V5 (negative potential in this example) that attracts the toner image 28c that is positively or negatively charged (positively charged in this example).

Therefore, the toner image 28c is attracted to the recording medium 1 by the Coulomb force acting on the positively or negatively charged toner image 28c, and the image is not disturbed even if the recording medium 1 moves or vibrates. In this example, a counter electrode 8 facing the holding electrode 4d is provided on the surface side of the recording medium 1, and the potential v3 of the counter electrode 8 is maintained at a higher potential than the fifth potential v5. . Therefore, an electric field is generated from the counter electrode 8 toward the holding electrode 4, and this electric field causes the toner image 28
C will be more strongly attracted to the recording medium 1.

In this example as well, the fourth electrode 29
The toner images 28b and 28c held on the recording medium by the holding means 4 are transported without image disturbance.
The transfer toner image 28d is transferred to the transfer object 7 (recording paper, etc.) by the transfer means 6.

Next, the fourth electrode 29 described in the first and second embodiments will be explained.

3 and 4 show the first support and each element formed on the first support.

In these figures, 21 is the first support and 23 is the first support.
24 is a photosensitive layer, 25 is a second electrode, 29 is a fourth electrode.
These electrodes are the same as those shown by the numbers in the first and second embodiments.

In the device shown in FIG. 3, the second electrode 25 is formed in a comb-like shape so that the surface potential of the photosensitive layer 24, which is involved in the formation of a toner image, is not affected by the potential of the fourth electrode 29. This is what I did.

In the case shown in FIG. 4, the second electrodes 25 are formed facing each other, and the photosensitive layer 24 is also involved in the formation of a toner image.
The surface potential of the fourth electrode 29 is not affected by the potential of the fourth electrode 29.

Note that what is shown in FIGS. 3 and 4 is only an example showing the relationship between the second electrode 25 and the fourth electrode 29. That is, if the relationship between the second electrode 25 and the fourth electrode 29 is maintained so that the surface potential of the photosensitive layer 24 involved in the formation of a toner image is not affected by the potential of the fourth electrode. good.

Further, the fourth electrode 29 is arranged on the first support 21 and/or
Alternatively, it may be formed on the photosensitive layer 24.

Furthermore, when the second electrode 25 and the fourth electrode 29 are formed by photolithography, it is preferable to form them by the same photolithography process because this can simplify the manufacturing process.

Although one embodiment of the present invention has been described above, it is not necessary to provide a charging means or a holding electrode.

[Effect] According to the present invention, the toner image formed on the first support and/or the photosensitive layer is maintained at a fourth potential so as to attract a positively or negatively charged toner image when the recording medium is moved. To obtain an electrophotographic recording device capable of performing high-quality recording by attracting a toner image to a recording medium and not disturbing the toner image even if the recording medium moves or vibrates because of the provision of the fourth electrode. Can be done.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing one embodiment of the present invention, Fig. 2 is an explanatory diagram showing another embodiment of the invention, and Figs. 3 and 4 are the same diagrams as Figs. FIG. 5 is an explanatory diagram showing a conventional example. 1...Recording medium 1...First support 2...Second support 3...First electrode 4...・Photosensitive layer 5...Second electrode 6...Third electrode 7...Light source 9...Fourth electrode 112

Claims (1)

[Scope of Claims] A first support having translucency, a second support disposed opposite to the first support, and the second support of the first support. a light-transmitting first electrode formed on a surface facing the body and held at a first potential; a photosensitive layer formed on the first support including the first electrode; a second electrode partially formed on the photosensitive layer and held at a second potential; and a second electrode formed on the surface of the second support facing the first support and held at a third potential. and the surface of the photosensitive layer in the irradiated portion by irradiating light onto the photosensitive layer in the portion where the second electrode is not formed from the back side of the first support. a recording medium to which charged toner flying from the charging electrode is attached by a Coulomb force generated by a potential difference between the changed surface potential of the photosensitive layer and the potential of the third electrode; The toner formed on the first support and/or the photosensitive layer and attached when the recording medium is moved,
and a fourth electrode held at a fourth potential so as to attract the recording medium.