JPS61278874A - Image forming device - Google Patents

Abstract

PURPOSE:To attain image formation with low voltage and high sensitivity by irradiating image light by an image exposing means from the transparent substrate side of a recording medium such as a recording film obtained by forming a transparent conductive film and a transparent photosensitive layer on a transparent substrate. CONSTITUTION:The tilted device is provided with the recording medium 1 obtained by forming the transparent conductive film 3 and the transparent photo sensitive layer 4 on the transparent substrate 2, a conductive substrate 5 to which electrically charged photoconductive toner 6 is uniformly adhered and the image exposing means 8, voltage is applied between the film 3 of the recording medium 1 and the substrate 5 by a power supply 9 or the like, the substrate 5 adhering the toner 6 is arranged adjacently to the layer 4 of the medium 1, and image light is irradiated by the exposing means 8 from the substrate 2 side of the medium 1 oppositely to the substrate 5. Consequently, trapped electric charge is formed on the layer 4 by the image light, the image light transmitted through the substrate 2, the film 3 and the layer 4 is made incident upon the toner 6 adhered to the substrate 5 and the resistance of the toner 6 is reduced.

Description

[Detailed Description of the Invention] [Summary] A charged photoconductive toner is attached to the transparent photoconductor layer side of a recording medium having a three-layer structure of a transparent substrate, a transparent conductive film, and a transparent photoconductor layer, and a transparent conductive film is also attached to the recording medium. A conductive substrate to which a voltage is applied is placed between the recording medium and image light is irradiated from the transparent substrate side of the recording medium to form trapped charges in the transparent photoreceptor layer, and the image light transmitted through the recording medium is The photoconductive toner is irradiated to reduce its resistance, and the photoconductive toner with reduced resistance is injected with charge from the conductive substrate side to be charged to the opposite polarity, thereby causing the inside of the transparent photoreceptor layer to be charged. An electrostatic force is generated between the photoconductive toner and the trapped charges, and an image is formed on the recording medium by photoconductive toner corresponding to the image light.

[Industrial application field]

The present invention uses a photoconductive toner and a transparent recording medium,
The present invention relates to an image forming apparatus that forms an image using photoconductive toner corresponding to image light on a transparent window light layer of a recording medium, and displays or transfers the image.

Current copying machines generally use an electrophotographic recording system, and copying is performed through steps such as charging, exposure, development, and transfer. In this recording method, charging is performed by corona discharge, but a method for recording and displaying without using corona discharge has also been proposed.

[Conventional technology]

In the conventional electrophotographic recording method, for example, as shown in FIG. 3, a recording drum 31 having a photoconductive layer 32 made of selenium or the like is rotated in the direction of the arrow, and recording is performed by a corona discharger 33 to which a high DC voltage is applied. The surface of the drum 31 is uniformly charged, and then image light is irradiated by the image exposure means 34 consisting of a laser or the like to form an electrostatic latent image corresponding to the image light on the recording drum 31, and then black fine particles are toner is applied by the developing device 35 to visualize the electrostatic latent image. in this case,
The toner is charged to the same polarity as the charge charged by the corona discharger 33, a voltage is applied between the developing device 35 and the recording drum 31, and the toner is electrostatically attached to the recording drum 31 by the electric field. The image is then developed.

Next, the toner image is transferred to a recording paper 40 by a corona discharger 36.
By charging the recording paper 4 with a polarity opposite to that of the toner,
0 and the transferred toner image on the recording paper 40 is
The image is thermally fixed by the fixing device 37.

Further, the toner remaining on the recording drum 31 is removed from the recording drum 31 by a static eliminating corona discharger 38 to which an AC high voltage is applied.
The fur brush 39 neutralizes the charge on the top and the charge on the toner.
At the same time, the surface potential of the recording drum 31 is reduced to almost zero, and a series of image forming and transfer steps are completed, and this step is repeated as the recording drum 31 rotates.

As a method that does not use a corona discharger, for example, a recording means disclosed in Japanese Patent Application Laid-open No. 119375/1983 is known. For example, as shown in FIG.
1, a transparent conductive layer 42 made of ITO or the like is provided, and a photoreceptor layer 42 made of CdS or the like having a thickness of 65 μm is provided thereon.
3, and a white insulating layer 4 having a resistance value of a certain degree.
A conductive magnetic toner developer 46 is disposed opposite to the recording film 45 provided with the transparent conductive layer 42.
While applying a voltage from the DC power supply 51 between the
Image exposure is performed from the transparent substrate 41 side using a θ lens 49 or the like.

By this image exposure, the developing device 46 and the recording film 45
Since a voltage is applied between the transparent conductive layer 42 of
Toner is electrostatically adhered to the portion of the photoreceptor layer 43 whose resistance value has decreased due to the irradiation with light. On the other hand, since the thickness of the insulating layer 44 is sufficiently large in the areas that are not irradiated with light, the electrostatic adhesion between the toner and the toner is weak, and the toner is not deposited on the recording film 45. It will not stick. Therefore, a toner image 50 corresponding to image exposure is formed.

After image formation, the charges induced by light irradiation and the charges induced in the toner are discharged through the surface layer within one cycle of image display, and during the next image formation, they are discharged by the action of the magnet in the developing device 46. It is magnetically attracted and collected into the developing device 46. In this case, since the image exposure is performed from the transparent substrate 41 side of the recording film 45, toner collection, image exposure, and development can be performed simultaneously.

[Problem that the invention seeks to solve]

The conventional electrophotographic recording method described above uses corona dischargers 33, 36, 38 for charging and neutralizing, and the corona dischargers 33, 36, 38 are configured to apply a high voltage of several KV to the corona wire. Therefore, it requires a high voltage source and is easily affected by humidity, dust, etc., so it has the disadvantage of low reliability. Further, ozone generated by the corona discharger generates odor, and the large amount of ozone has an adverse effect on the human body. Furthermore, six processes are required: charging, exposure, development, transfer, static elimination, and cleaning.
This has the disadvantage that the device becomes complicated and large.

The conventional image forming apparatus shown in FIG. 4 has the advantage of not using a corona discharger, but it forms images by utilizing the difference in Coulomb force acting on toner between exposed and non-exposed areas. Therefore, the photoreceptor layer 43 must be formed thick. However, it is difficult to form the thick photoreceptor layer 43 to have a uniform thickness. Furthermore, by increasing the thickness of the photoreceptor N43, the amount of material used increases, resulting in an increase in cost. Further, as the photoreceptor layer 43 becomes thicker, it is necessary to increase the voltage applied between the transparent conductive film 42 of the recording film 45 and the developing device 46, and there is a drawback that the photosensitivity decreases. Furthermore, since it uses conductive toner, it has the disadvantage that it is difficult to transfer onto plain paper.

The present invention aims to improve the above-mentioned conventional drawbacks and perform image formation at low voltage and with high sensitivity without using a corona discharger.

[Means for solving problems]

The image forming apparatus of the present invention will be described with reference to FIG. 1. The image forming apparatus of the present invention includes a recording medium 1 having a transparent conductive film 3 and a transparent photoreceptor layer 4 formed on a transparent substrate 2, and a charged photoconductive toner 6. It is equipped with a conductive substrate 5 uniformly attached to the surface and an image exposure means 8, and a voltage is applied by a power source 9 or the like between the transparent conductive film 3 of the recording medium weight and the conductive substrate 5, and the recording medium 1 A conductive substrate 5 to which a charged photoconductive toner 6 is attached is arranged in close proximity to the transparent photoreceptor layer 4, and an image exposing means is applied from the side of the transparent substrate 2 of the recording medium 1 to face the conductive substrate 5. 8 to irradiate image light.

[Effect]

By the image light irradiated from the transparent substrate 2 side of the recording medium 1, trapped charges are formed on the transparent photoreceptor layer 4, and the transparent substrate 2. Transparent conductive film 3. The image light transmitted through the transparent photoreceptor layer 4 is incident on the photoconductive toner 6 attached to the conductive substrate 5, and the resistance of the photoconductive toner 6 is reduced. Charge is injected from the power source 9 into the photoconductive toner 6 whose resistance has been reduced, and the initial charge polarity is reversed. This photoconductive toner 7 with reversed charge polarity is electrostatically attracted to the trapped charges in the transparent photoreceptor layer 4, so that a toner image is formed on the transparent photoreceptor layer 4 in the area irradiated with the image light. is formed.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a detailed explanatory diagram of the present invention, in which 1° is a recording film, 11 is a transparent substrate, 12 is a transparent conductive film, 13 is a transparent photoreceptor layer, 14 is a magnetic brush developer, 15 is a metal roller, 16 is a bias power supply, I7 is a peeling blade, 18 is an exposure light source such as a warm body light source or a light emitting diode array, 19 is an optical system such as a lens, 20 is a recording paper, 21 is a conductive rubber roller, and 22 is a transfer unit. 23 is a cleaning brush, 24 is a static elimination lamp, and 25, 26, and 27 are photoconductive toners.

A recording film 10 as a recording medium has a transparent conductive film 12 formed on a transparent substrate 11, and a transparent photoreceptor layer 1 on top of the transparent conductive film 12.
It has a three-layer structure in which numeral 3 is formed, and is driven in the direction of the arrow with the transparent conductive film 12 being grounded. Further, the transparent substrate 11 is, for example, 100I! The transparent conductive film 12 is made of a polyethylene terephthalate (PET) film with a thickness of
For example, indium oxide (InzOs) with a thickness of 8 μm can be used as the photoreceptor layer 13, and an organic photosensitive material with a thickness of 8 μm can be used as the photoreceptor layer 13.

The metal roller 15 constituting the conductive substrate has a bias voltage
A negative voltage is applied by 16, and the magnetic brush developer 14 is grounded. The photoconductive toner is mixed with a carrier made of iron powder and is positively charged. This photoconductive toner is brought into contact with the metal roller 15 by the magnetic brush developer 14, and since a negative voltage is applied to the metal roller 15, the photoconductive toner 25 is positively charged.
is uniformly adhered to the surface of the metal roller 15.

The magnetic brush developer I4 in this embodiment is a means for uniformly adhering the photoconductive toner 25 to the metal roller 15, and the charged photoconductive toner 25 is applied to the metal roller 15 by other configurations. It is also possible to do so.

Further, the image exposure means is shown as being constituted by an exposure light source 18 and an optical system 19, but the exposure light source 18 may be a light emitting diode array and the optical system 19 may be constituted by a light converging fiber lens. Alternatively, the exposure light source 18 may be a semiconductor laser, and the optical system 19 may be configured with a polygon scanner, an fθ lens, or the like. Image light from this image exposure means is irradiated from the transparent substrate 11 side of the recording film 10.

When the recording film IO is irradiated with image light from the exposure light source 18 via the optical system 19, the resistance of the transparent photoreceptor layer 13 is reduced, and positive trapped charges are generated within the transparent photoreceptor layer 13. This charge results in the formation of an electrostatic latent image.

Further, the image light transmitted through the transparent substrate 11, the transparent conductive film 12, and the transparent photoreceptor layer side 3 of the recording film 10 is transmitted to the metal roller 1.
The positively charged photoconductive toner 25 on the surface of 5 is irradiated. As a result, the resistance of the photoconductive toner 25 is reduced, the positive charge is discharged through the metal roller 15, and the charge from the power source 16 is further injected to make the photoconductive toner 25 negatively charged.

Therefore, the negatively charged photoconductive toner 26 is attracted to the transparent photoreceptor layer 13 due to the electrostatic force between it and the positive trapped charges in the transparent photoreceptor layer 13 .

In addition, the transparent photoreceptor layer 13 in the part not irradiated with light maintains a high resistance state, and the photoconductive toner 2 in the part facing it maintains a high resistance state.
5 is also not irradiated with light, so it maintains a high resistance state and holds a positive charge, so it is attracted to the metal roller 15 by electrostatic force and is not attracted to the transparent photoreceptor layer 13. Therefore, an image is formed on the transparent photoreceptor layer 13 using the negatively charged photoconductive toner 26 .

The positively charged photoconductive toner 25 remaining on the metal roller 15 is then peeled off by the peeling blade 17 and returned to the magnetic brush developer 14 side.

The image formed by the photoconductive toner 26 can also be displayed with the recording film 10 stopped. Further, a conductive rubber roller 21 is pressed against the recording film 10 via the recording paper 20, and a positive voltage having a polarity opposite to that of the negatively charged photoconductive toner 26 is applied to the conductive rubber roller 21 from a power source 22.
The photoconductive toner 26 is attracted to the recording paper 20 by electrostatic force, and the image is transferred by the photoconductive toner 26.
The image transferred to the recording paper 2o is fixed by a fixing device (not shown).

The photoconductive toner 27 remaining on the recording film 10 without being transferred is removed by the cleaning brush 23, and the recording film 1o runs in the direction of the arrow, and the entire surface is irradiated with light by the static elimination lamp 24, making it transparent. Photoreceptor layer 1
The trapped charges within 3 are removed and the state returns to the initial state.

In the above embodiment, the print density is 0. D=1.0 or more,
Fog density 0. A fog-free copy density of D=0.02 or less was obtained.

Further, as the transfer means, it is possible to adopt various configurations other than the above-mentioned embodiments, for example, the recording film 10
It is also possible to have a configuration in which the above photoconductive toner 26 is once transferred to an adhesive intermediate transfer roller, and a heating roller is pressed into contact with this intermediate transfer roller via a recording paper, so that the photoconductive toner 26 is transferred and fixed onto the recording paper at the same time. It is.

〔Effect of the invention〕

As explained above, the present invention provides image exposure from the transparent substrate side of the recording medium 1, such as the recording film 10, in which the transparent conductive films 3, 12 and the transparent photoreceptor II 4゜13 are formed on the transparent substrate 2゜11. The means 8 irradiates the image light onto the recording medium I.
Charged photoconductive toner 6.26 is placed on the transparent photoreceptor layer side of the
A conductive substrate 5 such as a metal roller 15 to which a toner image is uniformly adhered is arranged, and a toner image corresponding to image light is formed on a recording medium. (1) Since a corona discharger is not used, high voltage No power supply is required and there is no negative effect from ozone. (2) As a power source, it is sufficient to use only the power source 16 for uniformly adhering the photoconductive toner and the power source 22 for transfer, and a low voltage source of about 100 V is sufficient. (3) Transparent photosensitive Since the thickness of the body layer 4.13 can be reduced, manufacturing costs can be reduced. (4) By reducing the thickness of the transparent photoreceptor layer 4.13, the recording voltage can be lowered and the photosensitivity can also be increased. (5
) By reversing the charge polarity of the photoconductive toner during development, it is possible to form a fog-free image.

(6) Since the photoconductive toner is in a high resistance state during transfer, it has various effects such as facilitating electrostatic transfer to plain paper.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the principle of the present invention, FIG. 2 is a detailed explanatory diagram of the present invention, and FIGS. 3 and 4 are explanatory diagrams of a conventional example. 1 is a recording medium, 2 is a transparent substrate, 3 is a transparent conductive film, 4 is a transparent photoreceptor layer, 5 is a conductive substrate, 6.7 is a photoconductive toner, 8 is an image exposure means, 9 is a power source, and 10 is recording film,
11 is a transparent substrate, 12 is a transparent conductive film, 13 is a transparent photoreceptor layer, 14 is a magnetic brush developer, 15 is a metal roller, 16
17 is a bias power source, 17 is a peeling blade, 18 is an exposure light source, 19 is an optical system, 20 is a recording paper, 21 is a conductive rubber roller, 22 is a transfer power source, 23 is a cleaning brush, 2
4 is a lamp for static elimination, and 25, 26, and 27 are photoconductive toners.

Claims (1)

[Claims] A recording medium (1) in which a transparent conductive film (3) is provided on a transparent substrate (2), and a transparent photoreceptor layer (4) is formed on the transparent conductive film (3); The photoconductive toner (6) is uniformly adhered to the surface and placed close to the transparent photoreceptor layer (4) of the recording medium (1), and the transparent conductive toner (6) of the recording medium (1) is
A conductive substrate (5) with a predetermined voltage applied between the conductive substrate (5) and the transparent substrate (2) at a position facing the conductive substrate (5) with the recording medium (1) in between. is irradiated to form trapped charges in the transparent photoreceptor layer (4), and the image light transmitted through the transparent photoreceptor layer (4) lowers the resistance of the photoconductive toner (6). A charge is injected into the resistive photoconductive toner (6) from the conductive substrate (5) side to reverse the charging polarity, and the photoconductive toner (7) with the reversed charging polarity is transferred to the transparent photoreceptor. An image forming apparatus comprising: an image exposure means (8) that electrostatically attracts trapped charges in the layer (4).