JPS59229585A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To obtain a simple, compact, and inexpensive device by allowing a conductive brush impressed with a voltage to contact a photosensitive body simultaneously with an insulating endless belt which is driven to rotate, and using one of support rolls for the belt as a pressure roll. CONSTITUTION:The electrostatic charging brush 3 contacts the photosensitive body 1 and conveyor belt 15 which rotate. The photosensitive body 1 is exposed at an exposure part E and then developed by a developing device 4. On the other hand, a form P conveyed by the conveyor belt 15 is separated from the conveyor belt 15 at the part of a belt support roll 12 with a separation plate 16 to enter in between the photosensitive part 1 and electrostatic charging brush 3 at a transfer part X, and transfer operation is performed. Then, the form is attracted to the conveyor belt 15 by a belt support roll 13 and passed through the fixing device consisting of a heat fixing roll 18 and a belt support roll 14 to be fixed. Then, the form is separated from the conveyor belt 15 with a separation plate 17 and discharged into a paper discharge tray 20. Consequently, the device is made simple, compact, and inexpensive.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to electrophotographic devices such as electrophotographic copying machines, facsimile machines, and printers.In particular, the present invention relates to paper conveyance, transfer, and fixing in electrophotographic devices. It's about technology.

In a copying method using an electrophotographic process, a uniform charge line is first applied to the surface of a photoreceptor formed of a photoconductive insulating film in a dark place. Next, the original image to be copied is projected onto the surface of the photoreceptor through a lens system to form an electrostatic image. There are various methods for developing this electrostatic image, but cascade development and magnetic brush development are common. Through development, the electrostatic image becomes visible as a toner image211
% After transferring this toner image to paper, permanent fixing is performed to complete the process.

Therefore, in a conventional electrophotographic copying machine, a charging device, an exposure mechanism, a developing device, a transfer device, a fixing device, a paper peeling means in a transfer section, a plurality of paper conveyance rolls, a conveyance belt, etc. are all independent. It has multiple members, has a complicated mechanism, and has a large number of parts.
It required a large space and was expensive to manufacture.

Furthermore, the complexity of the paper supply and conveyance system causes problems such as paper jams, and mechanical problems such as inserting a peeling claw between the photoreceptor and the paper in the transfer section to peel the paper. When a target peeling method is used, there are problems in that the surface of the photoreceptor is easily damaged and it is difficult to make full-scale copies (copies without margins).

The present invention was devised against this technical background, and includes a paper conveying means, a charging device, a transfer device, a paper peeling means 1 of a transfer section, a fixing device, and a single device. The aim is to simplify, make it more compact, and reduce production costs.

The imm two-unit invention is used in electrophotography, in which an insulating endless belt belt driven and rotated is provided, and a conductive brush to which a voltage is applied is brought into contact with the belt, and at the same time, the conductive brush is exposed to light. It also makes contact with the body, and one of the support rolls for the belt is also used as a pressure roll paired with a heat fixing roll, thereby forming a device that performs paper feeding, conveyance, charging, transfer, peeling, and fixing. This is characterized by the fact that the belt electrostatically attracts the river +lt, transports the paper from the paper supply section, and supplies the paper between the photoreceptor and the conductive brush σ to form a toner image. The transferred paper is transferred and removed from the photoreceptor by the electrostatic attraction of the belt.The transferred paper is separated between the belt support roll, which functions as a pressure roll, and the heat fixing roll. It is possible to perform fixing by supplying.

Embodiment Embodiment 7 An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 schematically shows the main parts of an electrophotographic apparatus such as an electrophotographic copying machine and a facsimile machine. In the figure, 1 is a belt-shaped photoreceptor made of an organic semiconductor (for example, polyvinyl carbazole). The photoreceptor 1 is stretched between a pair of belt support rolls 2. At least one of the pair of belt support rolls 2 is connected to a drive source (not shown) and rotates, and the photoreceptor 1 and the other support roll 2 also rotate accordingly.

Further, around the photoreceptor l, there are provided a charging brush 3 which is driven and rotated in the direction in which the photoreceptor l moves, a well-known developing device 4, a well-known cleaning device 5, and a paper transport holding device 10. (See Figure 1 above).

The charging brush 3 functions not only as a charger and a transfer device, but also as a charging means in the paper conveyance belt device 1 (H). The kit is made of 111J synthetic fiber, its resistivity is 103-108Ω, and the voltage of 1-5xV is
0 (see Figure 2).

Thus, the paper conveyance belt device 10 includes: a plurality of belt support rolls 11, 12, 13, 14, and a plurality of strips of insulating material (for example, polyester resin, polycarbonate, etc.) stretched between these support rolls; (resin) conveyor belt 15;
Belt support roll h 12.13rttl M At the same time, the charging brush 3 is in sliding contact with the upper surface of the conveyor belt 15 and also lightly in sliding contact with the lower surface of the photoreceptor l, and the peeling plate 16 is in sliding contact with the belt support roll 12.14. It is sufficient to drive at least one of the belt support rolls 11 to 154 (see FIGS. 1 to 3), and if necessary, The conveyor belt 15 may be a toothed belt, and correspondingly, each belt support roll may be provided with a pinion (=J'L).

Furthermore, a heat fixing roll 18 is disposed adjacent to and above the belt support roll 14, and the heald support roll 11
A paper feed tray 19 is disposed below the paper feed tray 19, and sheet-like papers P are stacked and stored inside the paper feed tray 19. A paper output tray 20 is disposed outside the belt support roll 14 and the heat fixing roll 18 (see Figure 1).
.

The belt support roll 11 is provided with a large diameter rubber feed roll 1 in a portion not in contact with each conveyance heald 15.
When the belt support roll 11 is displaced downward in response to the rotation of the photoreceptor l, the feed roll 11 CL comes into contact with the upper surface of the paper P, and the top layer paper P is carried out. It is keyed so that it will be done (Fig. 1, 3)
(see figure). Note that the downward displacement of the belt support roll 11 and the movement of the belt supporting roll 11 such as swinging in the direction of the arrow in FIG. 1 while maintaining the tension constant However, by placing a tension roll biased by a spring at a suitable position on the conveyor belt 15 (for example, between the belt support rolls 11 and 12) and engaging the belt support roll 11. It is possible to lower it straight down.

Furthermore, the stripping plate 16 has a plurality of stripping claws 16 that slide into contact with the belt support roll 12 between each conveyor belt 15.
ct (see FIG. 4) The shape of the peeling plate 17 and its relationship to the belt support roll 14 are also different from that of the peeling plate 16.
Since it is the same as that, detailed explanation thereof will be omitted.

In addition, the charging brush 3 has a
Base roll Wl! , 3α are fitted with a plurality of guide collars 3h, and the height of this guide collar 3b is
The length (r) of the brush fibers is also shortened by about -0.5 to 3 tnm, and is formed so as to be inclined with respect to the rotational direction of the conveyor belt 15 (see FIG. 2).

By the way, the reason for providing the guide collar 3h is to prevent the brush fibers from being damaged by the contact pressure of the conveyor belt 15.
For example, the reason why the N guide collar 3b is formed in an inclined shape is to prevent σ] when the charging brush 3 functions as a charger or a transfer machine. If the guide collar 3h is formed in a plane perpendicular to the rotation axis of the charging brush 3, charging and transfer will not take place at the location where the guide collar 31) is located, resulting in a white striped image. This is because omissions occur.

In this embodiment, the charging brush 3 is brought into rotational contact with the rotating photoreceptor I, the photoreceptor 1 is charged, and the photoreceptor 1 is exposed at one exposure time. This exposure can be performed using a laser, a light emitting diode (LKD), an optical fiber, a liquid crystal, etc., in addition to exposure using an optical lens. The image potential after exposure is 500 to 100 OV, and the static latent image on the photoreceptor IJ:f/l that has reached the fourth part of the developer is visualized by development. As this cursed image method, various methods can be adopted, such as component-based development, magnetic brush development, cascade development, liquid development, etc.

During this time, each belt support roll 11 to 14, the conveyor belt 1
5 also rotates in synchronization with the photoconductor 1 and the charging brush 3, and in synchronization with the charging and exposure accompanying the 10 rotations of the photoconductor, the belt support roll 11 descends and its feed roll 11 (L is , paper feed) The upper surface of the paper P in the tray 19 is probed. The conveyor belt) 15c'i is charged to several KV by contact with the charging brush 3, and the feed roll 11
(The uppermost layer of paper P, which has been carried out in contact with L, is electrostatically attracted to the conveyor belt 15 from its tip side, and is conveyed as the conveyor belt rotates 150 times.The belt support roll 11 Before it is completely unloaded 211. from the paper feed tray 19, it rises and returns to its original position.

The paper conveyed by the conveyor belt 15 reaches the belt support roll 12 section, is peeled off from the conveyor belt 15 by the peeling plate 16, and is transferred to the transfer section x1, that is, while in contact with the photoreceptor 1. The paper enters between the photoconductor 1 and the charging brush 3σ].The paper that comes into contact with the charging brush 3 is charged to a high potential,
The toner image attached to the photoreceptor 1 charged with the same polarity as the toner image is strongly attracted to the paper side. Incidentally, if exposure is performed before the photoconductor 1 advances to the transfer section X, the toner C/] transfer E will be the same as above.

Thereafter, the paper reaches the heald support roll 13, where it is attracted to the conveyor belt 15, and is peeled off from the g light body 1. The paper carrying the transferred toner image reaches the heald support roll 14. Ru. When the leading edge of the paper approaches the belt support roll 14, in the same way as the belt support roll 11 descends,
Conveyor Belt 15σ] While keeping the tension constant, the belt support roll 14 rises and contacts the heat fixing roll 18 with a predetermined pressure via the conveyor belt 15. Note that the release plate 17 is
It is constructed so that it can cooperate with the belt support roll 14 while always being in contact with the belt support roll 14, or it is constructed so that it can work together with the belt support roll 14 when the belt support roll 14 is raised.

In this way, the transferred moon JA attached to the conveyor belt 15 is...
The sheet passes through the fixing device composed of a thermal constant layer roll 18 and a belt support roll 14, and after fixing, is continuously peeled off from the conveyor belt 15 by a peeling plate 17, and then transferred to a paper output tray 20.
1st. By applying a bias voltage of the same polarity as the voltage applied to the charging brush 5 to the heald support roll 13, the effect of separating the paper from the photoreceptor 1 is improved.

On the other hand, the photoconductor 1 that has passed through the transfer section
Further, the photoreceptor 1 of the charger passes through the exposure section E, but no exposure is performed at this time, and the next exposure is performed on the photoreceptor 1 of the charger that has passed through the charging section 9S.

In this embodiment, in addition to the above-described paper feeding, conveyance, transfer, and post-transfer peeling performed by the charging brush 3 and the paper conveyance belt device IO, the +, li paper conveyance belt device 10 is As the charging brush also serves as a charging device and a transfer device, the structure of the device is extremely simplified; (t) The number of parts is small, the overall structure is compact, and the manufacturing cost of the device is low. .

Further, the paper that has been unloaded from the paper feed tray 19 is electrostatically absorbed by the conveyor belt 15, reaches the transfer section σ] which is absorbed by N and fed to 18 parts of the heat fixing roll.
It also has the advantage of not causing paper jams even when using thin ml and paper, ensuring reliable conveyance, and generating extremely little paper dust.

Furthermore, since the paper that has passed through the transfer section The device structure is simple, peeling errors are less likely to occur, and the photoreceptor 1 is not damaged and its durability is improved. 7-1 Since the peeling means does not touch the transfer aU of the paper at If''+ as in the conventional case, it is possible to apply toner to the entire width of the paper.

Furthermore, the voltage applied to the charging brush 3G is 11 to 5 KV.
This is advantageous in that it is lower than the 7 KV required for a corona discharger.

Note that in the above embodiment, instead of the belt-shaped photoreceptor 1, a drum-shaped photoreceptor 7 can be used.

Moreover, as shown in FIG.
? By installing developing devices 4A and 4Bji that can
A two-color image can be obtained on paper. That is, 1. In the first developing process, all the developing units 4A1/') stopped working,
In response to the first color development, two transfers, and the subsequent 10 rotations of the photoreceptor, release plate 17 and belt support roll 14 are released and placed, without peeling off the transferred paper after fixing. On the other hand, the photoreceptor 1 is cleaned, the photoconductor 1 is exposed to light after being charged, and the second color is developed by the operation G of the developer 4B, and the transferred paper is again processed. Perform transcription. Note that after the first color image is transferred, the photoreceptor must be 1σ before the next transfer.
] The time required for the rotation and the time required for the edge-rolled paper transported by the first transport belt 15 to enter the transfer section X must be exactly equal to each other, and If the length of the conveyor belt 15 is not long enough, it is necessary to align the image on the conveyor belt with the toner image on the paper after transferring the image of the first color.The transfer of the second color is completed. After that, as in the previous explanation, the conveyor belt 15 is fixed by constant inspection using the heat fixing roller 18 and the belt support roll 14, and by the peeling action by the peeling plate 17.
The paper is peeled off from the paper and discharged onto the paper discharge tray 20 at ℃.

Effects of the Invention As is clear from the above explanation, in one electrophotographic apparatus, a first non-insulating belt is provided for one drive rotation, and a conductive belt is applied with this pressure. brush? At the same time, the conductive brush is also brought into contact with the photoreceptor, and the support roll for the belt is also used as a pressure roll opposite to the heating and fixing roll.
The conductive brush is used as a charging device, a transfer device, and a charging means for the insulating endless belt. It is used as part of the supply/conveyance, post-transfer peeling means, and fixing device, and the device structure is simple, the number of parts is small, the overall structure is compact, and the manufacturing cost of the device is low. In addition, by electrostatically attracting paper to an insulating endless belt and transporting the paper without using a transport roll or the like as a transport means, reliable transport without paper jams is guaranteed, and the generation of paper dust is significantly reduced. . Furthermore, by electrostatically peeling off the paper using an insulating endless tape (+I/), it is possible to prevent damage to the photoreceptor and always obtain a good reproduced image.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the main parts of an electrophotographic apparatus according to an embodiment of the present invention, and FIGS. , FIG. 5 is a schematic diagram of main parts of an electrophotographic apparatus according to another embodiment. 1... Photoreceptor, 2... Belt support roll, 3...
Charging brush, 4... Developing device, 5... Cleaning device, 10... Paper conveyance belt % [, 11... Belt support roll, 11 (L... Feed roll, 12.
13.14... Belt support roll, 15... Conveyance heald, 16.17... Peeling [1ts... Heat fixing roll, 19... Paper feed tray, Add... Paper output tray, E・
・・M original part・X...Transfer part. Agent Patent Attorney Nozomi Ehara I

Claims (1)

[Claims] Electrostatically absorbed N on the surface of the rotating photoreceptor tl,'r-
In an electrophotographic device that electrostatically transfers a toner image to paper and fixes the transferred toner image with a heat fixing roll, it corresponds to the support roll and heat fixing roll located in the paper supply section. An insulating endless bell (Y) is stretched between multiple support rolls, including support rolls arranged in
At least one of the plurality of supporting rolls is used as a driving roll, and a conductive plastic sheet to which a voltage is applied is brought into contact with the insulating endless belt to form a sheet conveying means.1. It is brought into contact with the surface to form a charging rod/rotator, and the heat fixing roll G and the corresponding supporting roll form a pressure roll, and the insulating endless belt (TCR) is used to transport the paper and An electronic ′α true device characterized by peeling off paper after transfer.