JPH02223965A - Continuous electric insulating electronic photographic device - Google Patents

Abstract

PURPOSE:To make the device compact and to give a margin to the layout on the outer periphery of a rotary drum by arranging a writing device and a support device in the rotary drum. CONSTITUTION:A thermal head 2 as the writing device and a platen roller 3 are arranged in the rotary drum 1 across a photosensitive sheet A on the side of one driving roller 10. The shaft of the platen roller 3 is supported on the end plate of the drum 1 so as to rotate and move at right angles to the axis, the platen roller 3 moves toward the thermal head 2 arranged fixedly on the rotary drum shaft to contact the thermal head, and the shaft of the roller 3 is coupled with a driving transmission member to rotate in the same direction which the drum 1. Those writing devices 2 and 3 and support device are installed in the rotary drum 1. Consequently, the device can be designed with the margin of the layout and made compact.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an electrophotographic apparatus using a photoreceptor sheet made of a continuously electrically insulating electrophotographic material.

This type of photoreceptor sheet itself has been known in the past, and as shown in FIG. A conversion layer 25 is formed in which a substance and a conductivity change imparting agent are blended. This photoreceptor sheet A has the property that when the conversion layer 25 is exposed to light, the electrical resistance of that part decreases and becomes conductive, and when heated, it returns to its original insulating property, and also remains in each state for a certain period of time. It is known that there is a memory function that persists.

Conventionally, an electrophotographic apparatus as shown in FIG. 5 is known as an electrophotographic apparatus that utilizes the properties of such a photoreceptor sheet. That is, a photoconductor sheet in the form of a sheet is fed along the photoconductor insertion path 61, and this photoconductor sheet passes through the photoconductor writing path 62a (no writing is done at this time) and is wound around the rotating drum 51. As the drum 51 rotates, the entire surface is exposed by the entire surface exposure device 59 to make the conversion layer conductive.

This entire exposed photoreceptor sheet is peeled off from the drum 51 and transferred to the photoreceptor writing paths 62b and 62c.

62a, the photoreceptor sheet is supported by a platen roller 53, which is a support device, and heated by a thermal head 52, which is a writing device, and image data is written by making the heated portion insulating.
Furthermore, it is tightly wound around the drum 51 again. As mentioned above, the photoreceptor sheet remains conductive or insulative for a certain period of time, so after data is written, as the drum 1 rotates, the insulating part, that is, the writing part, becomes a charging bag! 54 to form a latent image;
Developing this latent image by a developing device 55 to form a developed image, transferring this to plain paper conveyed along a paper feed path 60 by a transfer device 56, and separating device 57.
Each step of cleaning the photoreceptor sheet from which the plain paper has been separated by the cleaning device 58 is repeated in order, thereby producing a large number of copies.

After copying many copies.

The photoreceptor sheet has a writing path 62b and a discharge path 63.
It is then discharged.

Furthermore, since it is relatively difficult to tightly wrap the photoreceptor sheet around the drum in the above-mentioned apparatus, an electrophotographic apparatus as shown in FIG. 6 is known. In this device, a photoreceptor sheet is wound into a roll around a pair of drive rollers 81 and 82, and these drive rollers 81 and 82 are installed inside a drum 71. In addition, a thermal head 72 and a platen roller 73 are installed in an opening formed in the peripheral wall of the drum 71.
and is provided. The photoreceptor sheet wound around one of the drive rollers 81 is pulled out through a slit formed in the drum 71, wrapped around the circumferential surface of the drum 71, and then passed through the same slit as described above. It enters the interior and is wound up by the other drive roller 82.

In this state, as the drum 71 rotates, the entire surface is exposed by the exposure device 79, and then image data is written by the thermal head 72 as the drive rollers 81, 82 wind up and rewind. Thereafter, by repeating the copying process using the charging device 74, the developing device 75, the transfer device 76, the separating device 77, and the cleaning device 78 in the same manner as described above, the image is transferred onto the plain paper conveyed through the paper feed path 80, and a large number of sheets are A copy of is obtained.

However, the conventional apparatus shown in FIG. 5 has image writing paths 62a and 62b in addition to the paper feed path 60.

62c is required, and this path is complicated, which makes it impossible to make the device more compact.

Furthermore, in the conventional device shown in FIG. 6, an opening for installing the platen roller 73 must be formed in the drum 71 in order to obtain a delicate pressure contact force of the thermal head 72, which causes problems in processing and accuracy. In addition to this, there was a drawback that the strength was lowered. Furthermore, since the thermal head 72 is present on the outer periphery of the drum 71, there is less space on the outer periphery of the drum.

This invention solves the conventional problems as described above.

To provide an electrophotographic device which can be made compact, and which can provide a layout on the outer periphery of the drum without making the drum a complicated shape.

This invention aims to solve the above-mentioned problems and achieve the purpose of
It is characterized in that the writing device and the support device are arranged within the rotating drum.

(11) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall configuration of an electrophotographic apparatus according to the present invention, in which an image of an original placed on a contact glass 22 is emitted from a light source 16 for irradiating the original, and is directed to a reflecting plate 15, an original,
The light passing through the second and third mirrors 17, 18, and 19° lens 20 forms an image on a photoelectric conversion device 21, and the optical image is converted into an electrical signal.

The photoreceptor sheet A is applied to the outer periphery of the rotary drum 1 by a pair of drive rollers 10, 11 installed within the rotary drum 1, similar to the conventional apparatus shown in FIG. Although the shafts of the drive rollers 10 and 11 are not shown, they are rotatably supported by the end plates of the drum 1, and when the drum 1 rotates and stops at the first illustrated position, a drive transmission member is connected to the shafts of the drive rollers 11 and 12. The driving rollers 11 and 12 are rotated in forward and reverse directions to perform winding and rewinding operations of the photoreceptor sheet A.

A charging device 4, a full-surface exposure device 9, a developing device 5, a transfer device 6, a separating device 7, and a cleaning device 8 are arranged in order around the rotating drum 1 along its outer peripheral surface. A fixing device 112 is arranged adjacently. 14 is plain paper (transfer paper), and this plain paper 14
is transported to the transfer section by the paper feed group [13].

According to this invention, a thermal head 2, which is a writing device, and a platen roller 3 are arranged in a drum 1 so as to sandwich the photosensitive sheet A on one drive roller 10 side. Although the shaft of the platen roller 3 is not shown, it is rotatably supported by the end plate of the drum 1 and movable laterally in a direction perpendicular to the axis. The shaft of the roller 3 is connected to the drive transmission member and rotates in the same direction as the drum 1.

The operations of each of the above components are as shown in FIG.
It is controlled by a control circuit 26 having ROM, RAM, receiver, and driver.

Next, the operation of the electrophotographic apparatus will be explained.

The original on the contact glass 22 is read by the photoelectric conversion device 21 as described above, converted into an electrical signal, and data processed by the control circuit 26.

On the other hand, the photoreceptor sheet A attached to the drum 1 is exposed by the full surface exposure device 9 as the drum 1 rotates, so that the conversion layer 25 is made conductive. The film is wound onto the driving roller 10 by the winding operation and the unwinding operation of the driving roller 11 .

The photoreceptor sheet A is rewound from the drive roller 10 and taken up again by the drive roller 11. At this time, the platen roller 3 moves to the position indicated by the chain line in FIG. 1, and the photoreceptor sheet A is brought into close contact with the thermal head 2. Image data is written. That is, the image data-processed by the control circuit 26 is transferred to the thermal head 2, and the photoreceptor sheet A is heated by the heating element at the location corresponding to the black dot on the image, and the writing section, which is the heated section, becomes insulating. be done.

After one line of heating is completed, the image reading advances by one line, and the photoreceptor sheet is also moved by one line by being fed by the drive of the platen roller 3.

At this time, the roll paper-like photoreceptor sheet A is sent out by the drive roller 10 by a slightly larger feed amount than the feed amount by the platen roller drive, and the photoreceptor sheet A sent out by the platen roller 3 is wound by the drive roller 11. taken.

When the writing by the thermal head 2 is completed, the entire portion of the photoreceptor sheet on which the image is written is sent out onto the surface of the rotating drum 1, and then the platen roller 2 returns to the position shown by the solid line in FIG. The photoreceptor sheet A is fixed, and the slack of the photoreceptor sheet A is taken up by the winding of the drive roller 11, and the photoreceptor sheet A is brought into close contact with the drum surface for one rotation.

The series of plate-making processes as described above are performed at the stop position of the rotating drum 1 shown in the first figure.

Next, the process moves to a copying process, and in this process, the drum 1 around which the photoreceptor sheet A produced in the above-mentioned manner is wound is rotated. At this time, the drive rollers 10, 11 and the platen roller 3 rotate together with the drum 1 around the drum axis, and the thermal head 2 rotates together with the drum axis. As the drum 1 rotates, the portion of the photoreceptor sheet A heated by the corona discharge of the negatively charged bag [4, that is, the written portion, is negatively charged.

An electrostatic latent image is formed. Approximately -6K is applied to this negative charging device 4.
A voltage of V is applied.

Next, toner is attached to the electrostatic latent image by a developing device 5 to form a developed image, and this toner image is transferred onto plain paper 14 fed by a paper feeding device 13 by a transfer device 6 that performs negative corona discharge. transcribed. The plain paper 14 is further separated from the photoreceptor sheet A by the separating device 7, the image is fixed by the fixing device 12, and the paper is discharged.

On the other hand, the photoreceptor sheet A is cleaned by the cleaning device 8 by the rotation of the drum 1, and then charged again.
Development, transfer, and cleaning are repeated in this order, and along with this, plain paper 14 is supplied, and a large number of copies are continuously made.

After this copying process is completed, a new original is placed on the photoreceptor sheet A.
When writing on the photoreceptor sheet A, the photoreceptor sheet A is made conductive again by rotating the rotary drum 1 and irradiating light with the entire surface exposure device 9. Thereafter, the rotating drum is stopped at the position shown in FIG. 1, and the plate-making process is carried out in the same manner as described above.

The conversion layer 25 is formed by blending a charge transport substance and a conductivity change imparting agent as described above, and the charge transport substance may be any of the following.

(1) Polymer photoconductors, such as polyvinyl carbazole, polyN-ethylenically unsaturated group-substituted carbazoles, polyN-ethylenically unsaturated group-substituted phenothiazines, polyvinylpyrene, and the like.

(2) Low-molecular photoconductors, such as oxodiazoles and hydrazones substituted with alkylaminophenyl groups.

Combinations of pyrazolines and triphenylmethane derivatives with binder resins (silicone resins, polycarbonate resins, polyvinyl acetal resins), (3) Polymer conductors such as polyacetylene, polydiacetylene, etc.

(4) The low-molecular charge transfer complex conductivity change agent consists of a substance that reversibly undergoes a structural change between nonionic and ionic properties in response to light or thermal energy. Specifically, a spiropyran compound or
Derivatives thereof are preferred.

The blending ratio of the charge transporting substance and the conductivity imparting agent can be selected depending on the desired function and application, but usually 0.00% of the conductivity imparting agent is added to 1 mole of the charge transporting substance. Blend 1 to 1 mole of O.

AM, which is commonly used as a conductive support, is disadvantageous because it forms an oxide film on the surface and acts as a barrier layer against hole injection.

Therefore, Zn, Ti, Ag, and Fa are preferred.

Metal or semiconductor elements such as Sn, Cu, In, or SnO, In, O, ZnO, Tie.

These are oxide semiconductors such as NiO, WO, V, and O.

Next, in the photographic photoreceptor material described above, changes in conductivity upon application of thermal energy and exposure will be explained.

FIG. 4 is a conceptual diagram showing the process of increasing the insulation properties of the conversion layer 25 by causing a structural change from non-ionic to ionic when thermal energy is applied to a conductivity-imparting agent with memory properties. be.

The charge transport material contained in the conversion layer 25 is a so-called P-type semiconductor with high hole mobility. When the conversion layer 25 in which a conductivity change imparting agent (A, A+-) is added is irradiated with light in the absorption wavelength range, a nonionic structure (stable upon ring closure) is formed due to a photochemical reaction of the conductivity change imparting agent. Change. The conductivity change imparting agent that has changed to a nonionic structure no longer acts as a hole trapping agent, and becomes so-called conductive [FIG. 2(a)].

Next, by heating a predetermined position with a thermal head or the like, the conductivity change imparting agent changes from a nonionic structure (stable upon ring closure) to an ionic structure (stable upon ring closure) and acts as a hole trapping agent. Holes injected from the conductive support 24 (electrode material) are trapped by the conductivity change agent.
As detrapping is repeated, the mobility of holes substantially decreases, resulting in insulating properties [FIG. 6(b)].

Next, when the surface of the conversion layer 25 is uniformly negatively corona charged by the charging device 4, only the insulating portion is charged. As a result, a charge distribution corresponding to the image, a so-called latent image, is formed [see figure (
c)) Moreover, this conductive and insulating state exists stably for a long time in a dark place, resulting in a photosensitive material with memory properties.

As described above, according to the present invention, since the writing device and the support device are installed inside the rotating drum, it is not necessary to provide a photoreceptor writing path around the rotating drum as in the conventional case. This eliminates the need for this, and therefore allows for a design with more room in terms of layout, making it more compact and reducing manufacturing costs. Further, there is no need to provide the rotary drum 2 with an opening for a platen roller as in the prior art, and the processing is easy, and a drum that is stable in terms of accuracy and strength can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an overall front view showing one embodiment of the present invention, FIG. 2 is a block diagram of a control system, FIG. 3 is a sectional view of a photoreceptor sheet, FIG. 4 is an explanatory diagram of conductivity changes, and FIG. Figure 6 is a front view showing a conventional example. 1... Rotating drum 2... Thermal head 3.
...Platen roller 4...Charging device 5...Developing device 6...Transfer device 7...Separation device
8...Cleaning device 9...Full surface exposure device 1
0.11... Drive roller 12... Fixing device
13...Paper feeding device 14...Plain paper 16.
...Light source 21...Photoelectric conversion device patent applicant Tohoku Ricoh Co., Ltd. Figure 2

Claims (1)

[Scope of Claims] 1. A full-surface exposure device that exposes the entire surface of a photoreceptor sheet, which is formed by providing a conductive support on a base film and further providing a conversion layer thereon, to make the conversion layer conductive; A device that writes image data by heating the photoreceptor sheet after full-surface exposure and making the conversion layer in the heated part insulating, a device that supports the photoreceptor sheet when writing image data, and a device that writes image data. Persistent electrical insulation photographic device comprising a rotating drum around which a photoreceptor sheet is wound, characterized in that the writing device and the support device are disposed within the rotating drum. Electrophotographic equipment.