JPS63183477A - Image forming device - Google Patents

Abstract

PURPOSE:To form excellent images over a long period by abutting a conductive member on a conductor layer exposed in the moving direction of a recording body on the outside of a recording image area and arranging other abutting members on the outside from a part of the abutting area. CONSTITUTION:A gap roller 5 for setting and maintaining a gap between the roller 5 itself and a developing sleeve 4 in a developing means 22 and a conductive brush 7a for obtaining conductivity are abutted upon the surface of a belt- like photosensitive body 1 at the vicinity of a peripheral edge part. The brush 7a is always abutted upon the body 1 in the exposing area 3 of the conductive layer 31 also in the rotation of the photosensitive body 1 and one end of the brush 7a is electrically earthed. The roller 5 is abutted upon the photosensitive body 1 under pressure on the outside from a part of the abutting peripheral area of the brush 7 in an area 3, i.e. on the peripheral end part of the photosensitive body. Thus, excellent images can be obtained even if recording operation is repeated over a long period.

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a conduction mechanism for a recording medium, etc. in an image forming apparatus, particularly an electrostatic recording electrophotographic apparatus, a printer, or the like. (Prior Art) Conventionally, in an image forming apparatus using an endless belt-like recording medium or a drum-like recording medium in which a conductive layer is sandwiched between an insulating support and a dielectric layer or a photoconductive layer, the above-mentioned recording A method has been used in which the conductive layer is exposed at the circumferential end of the body and a conductive brush, conductive roller, etc. is brought into contact with the conductive layer to establish electrical continuity with the recording medium. However, in recent years, in order to maintain the gap between the image forming process equipment installed around the recording medium, especially the corona removal/charging device, the developing device, etc. and the recording medium with a small uniformity and high precision, some of the above-mentioned devices are required. A method is used in which the recording medium and the outside of the recorded image area of the recording medium are brought into contact with each other via a gap member, a gap roller, or the like. The recording media used in these image forming devices are
A dielectric layer, a photoconductor layer, etc. is provided on a conductive support such as aluminum, and conduction with the recording medium is established by placing a conductive member on the back side of the conductive support. It is possible to easily remove the dielectric layer or optical I dummy layer, which is the surface layer of the recording medium, or the conductive Even if the surface layer of the support was 111% J, the conductivity in the recorded image 6n region could be maintained reliably since conduction was provided on the back side. (Problem to be solved by the invention) However, an endless heddle-like recording medium or an L-ram sandwiched between a conductor layer, an insulating support, and a dielectric layer or a photoconductor layer as described above. The shaped recording material is used in an image forming apparatus using an image forming process device in which the above-mentioned Iil 1 part O A, inter 1 brick roller, etc. are brought into contact, and the exposed conductor layer is coated with
Even if the contact member is brought into contact to establish continuity, there may be no problem initially, or as the number of recording operations increases due to repeated rubbing due to the contact of the gap member, gap rollers, etc., the surface layer of the recording medium The dielectric layer or photoconductor layer will wear out. Furthermore, the electrocardiogram layer may also be abraded, and the conductor layer of the recorder disappears in the direction of movement of the recorder, dividing it into areas with no electrical continuity, and in some cases, the recorded image area. There was a problem in that the conductive contact member and the conductive contact member could not be electrically connected at all. In addition, the conductive layer used in the recording medium is often a metal thin film layer or 170 layer vacuum-deposited on an insulating support, a laminated metal foil layer, a coated conductive paint film, etc. These have a problem that they have poor abrasion resistance and are easily worn away by the rubbing of the gap members and gap rollers, making it difficult to obtain durability as a recording medium. Also, is it possible to provide a protective EKBE, a protective ring, etc. in the circumferential direction on the surface of the recording medium at the gap area and the contact area of the gap roller? There were some failures and fortune-telling, such as poor accuracy and increased costs. (Means for Solving the Problems) The present invention eliminates the drawbacks of the above-mentioned conventional example and also improves the gap gap and the sliding contact member such as the gap roller.

Even if a part of the conductive layer of the recording body disappears in the moving direction of the recording body, the recorded image area of the recording body and the conductive contact member reliably maintain electrical conduction with each other. This makes it possible to use the recording medium for a long period of time.
, one nogo. (Embodiment 1) The present invention will be explained in detail based on an example in which the present invention is applied to an electrophotographic device 2♀ as shown in FIG. In Fig. 5, the endless hel]-shaped photoreceptor 1 or the direction in the figure 1)
17 Rotated by a moving roller 8, charging means 20, image exposure means 21, developing means 22, transfer means 2 to transfer paper 25
3. A copy image is obtained by sequentially operating the static eliminating means 24. Held shape 1: A developing means 22 is provided on the surface of the y-light body 1.
A gap roller 5 for setting and maintaining the gap with the developing sleeve 4 and a 4N brush 7a, which is a 4N conductive contact member for obtaining electrical conduction, are located near the peripheral end of the belt-shaped photoreceptor 1. It is in contact. FIG. 1 is an explanatory diagram of the present invention, and FIG. 5 is a schematic top view of the apparatus. FIG. 2 is an enlarged cutaway sectional view for further explaining the contact situation between the gap roller 5 and the belt-shaped photoreceptor 1. FIG. The belt-shaped photoreceptor 1 used here has a PET (polyethylene terephthalate) film 3 which is an insulating support.
A conductive layer 31 on which aluminum was vapor-deposited over the entire surface and an organic photoconductor layer 32 were sequentially laminated on top of the photoconductor. This organic photoconductor layer 3
2 is provided in the recording image area 2 in FIG.
At least at one circumferential edge of the heald-like photoreceptor 1, the conductive layer 31 is exposed in the circumferential direction, forming an exposed region 3. The belt-shaped photoreceptor 1 is suspended by a drive roller 8 and a tension roller 9 that are pivotally supported by a side plate 10, and is rotated by a drive source (not shown). In the exposed area 3 of the conductive layer 31, the conductive brush 7a
・\r)・While the photoreceptor 1 rotates, it is constantly in contact with the photoreceptor 1, and one end thereof is electrically grounded. Then, the gap roller 5 is brought into pressure contact with the exposed area 3 at a position outside a part of the contact peripheral area of the conductive blank 7a, that is, at a position located at the further peripheral end of the heald-like photoreceptor 1. The developing sleeve 4 is driven around the axis of the developing sleeve 4 and the photoreceptor 1. In addition, the gap roller 5 is made of a non-elastic material such as engineering plastics or metal in order to accurately maintain the 1111 gap between the developing sleeve 4 and the belt-shaped photoreceptor 1. Now, in this device, when a recording operation is performed, the conductive layer 3
1 and the conductive brush 7a were able to maintain electrical continuity with each other, and a good image could be obtained. If the operation is repeated in history, the aluminum vapor deposited layer, which is the conductor layer 31, will wear out in the contact peripheral area 6 of the gap roller 5 after approximately 1000 operations, and the aluminum vapor deposited layer, which is the conductor layer 31, will wear out and become conductive as shown in Fig. 2. The body layers 31 are conductive layers 31a and 3 that are not electrically conductive to each other.
] b. However, since the conductive brush 7a is organically photosensitive, it has been possible to obtain images as good as the initial image. Further, when the recording operation was repeated, the organic photoreceptor layer 32 operated satisfactorily until the end of its photosensitive characteristic life. (Example 2) As shown in FIG. 3, the conductive brush 7 is placed at a different position from the present invention.
When the conductor layer 31 is disposed, the conductor layer 31 is broken and divided in the contact peripheral area 6 of the gap roller 5 after approximately 1000 recording operations as in Example 1, and the four-conductor brush 7a and the organic photoreceptor layer are separated. The state of contact with the conductive layer 31b on the 32 side could no longer be maintained, making it difficult to form images later. (Example 3) Using the same device as in Example 1, a fourth conductive brush was used instead of the conductive brush.
As shown in the figure, a conductive rubber roller 7b rotating around a metal shaft 11 fixed to a side plate was used. As in the first embodiment, this conductive rubber roller 7b is constantly in contact with the exposed area 3 of the conductive layer 31 during the rotation of the heald-like photoreceptor 1, and is electrically grounded through the metal shaft 1. There is. The gap roller 5 is a conductive rubber roller 7 in the exposed area 3.
The belt-shaped photoreceptor 1 is pressurized at a position located outside a part of the contact circumferential area b, that is, at a further circumferential end of the belt-shaped photoreceptor 1 . Now, when a recording operation is performed in this device, the conductive layer 31
The conductive rubber roller 7b and the conductive rubber roller 7b have maintained electrical conductivity with each other, and good images have been obtained. When the recording operation is repeated further, the contact peripheral area 6 of the gap roller 5 is recorded after about 1000 operations. - The aluminum vapor deposited layer, which is the electric conductor layer 31, has thinned out, and as shown in FIG. 2, the electric conductor layer 31 has been broken and divided into conductor layers 3+a and 31b which are not electrically conductive to each other. However, since the conductive rubber roller 7b was maintained in contact with the conductive layer 31b on the organic photoreceptor layer 32 side, it was possible to obtain an image as good as the initial image. When the recording operation was further repeated, it worked well until the photosensitive characteristic life of the organic photoreceptor layer 32 was reached. In this example, an endless heddle-shaped photoreceptor was described.
Not limited to this, a conductor layer,
The present invention can similarly be applied to various image forming apparatuses using a drum-shaped photoreceptor formed by sequentially forming photoconductor layers. In addition, a transparent conductor layer and a photoconductor layer are sequentially formed on a transparent endless heald or clast drum support, and a light source and a liquid crystal shutter are combined on the side of the support (inside the enclosed space) of the endless heald or clast drum. The present invention can also be applied to a recording device such as a printer that includes an exposure device that performs exposure according to an image signal such as an LED or an LED. In particular, materials for the transparent conductor layer are limited, and vapor-deposited thin films such as ITO are used due to transmittance considerations, and these have very low wear resistance, so it is extremely difficult to apply the present invention to them. It is effective for In addition, in this example, the abutting parts of the gap rollers, etc. were bare conductive layers, or it is possible to provide a protective layer except for the abutting parts of the conductive abutting members, or it is possible to provide a protective layer with a length that will extend the life of the conductive abutting member. Eventually it will wear out. Furthermore, the conductive contact member is not shaped like the brush or roller of this embodiment, but is instead a roller. Naturally, springs, elastic bodies, etc. can also be used. (Effects) As described above, with a simple configuration in which the contact position of the conductive contact member is placed closer to the recording image area than the contact position of the other contact members, it is possible to This has the effect of making it possible to completely ignore the flame effects caused by the abrasion of the recording medium.

[Brief explanation of the drawing]

FIG. 1 is a schematic top view of a device for explaining the present invention, and FIG.
The figure is an enlarged cutaway sectional view illustrating the contact situation between the gap member and the photoreceptor, FIG. 3 is a schematic top view of a device not using the present invention, and FIG. 4 is a top view showing another embodiment according to the present invention. FIG. 5 is a schematic plan view of a recording apparatus to which the present invention is applied. 1-m=photoreceptor 2-m=recorded image area 3-m-bare area 5-m-gap roller 6-m-contact peripheral area 7a/7b-m-conductive brush and roller 30---
Insulating supports 31.31a, 31b--one conductor layer 32--organic photoconductor layer

Claims (4)

[Claims] (1) In a recording medium in which a conductive layer is sandwiched between an insulating support and a dielectric layer or a photoconductive layer, at least the conductive layer is located outside the recorded image area of the recording medium in the direction of movement of the recording medium. A conductive member is brought into contact with the exposed conductor layer, and another member which comes into contact with the recording medium outside the recorded image area is placed at least outside of a part of the conductive member contact circumferential area. An image forming apparatus characterized in that the image forming apparatus is disposed in. (2) The image forming apparatus according to claim 1, wherein the conductive member is a brush-like contact member made of conductive fibers. (3) The image forming apparatus according to claim 1, wherein the conductive member is a roller-like or roller-like contact member. (4) The image forming apparatus according to claims 1 and 3, wherein the conductive member is an elastic member.