JPH08262844A - Image forming device - Google Patents

Abstract

PURPOSE: To provide an image forming device excellent in durability and safety, without adversely affecting the environment in use. CONSTITUTION: In the image forming device constituted in such a manner that a photosensitive layer 14 is provided on the outside surface of a freely rotatable closed loop-like substrate drum 13 and an electrifying means 11, an exposure unit 2, a developing unit 3, a transfer unit 4, a fixing unit 5 and a cleaning means 12 are provided around the substrate drum 13, it is composed of lightweight elements and the electrifying means 11 is composed of an electrifying X-ray generator means which is provided in the drum 13 and passes X-rays through the drum 13 and the photosensitive layer 14, to irradiate them, so that the air on the surface of the layer 14 is ionized and an electric field applying means for leading a gas ion generated by the ionization to the surface of the layer 14 by an electric field. Further, the cleaning means 12 is composed of an erasing X-ray generator means which ionizes the air on the photosensitive layer on which coloring fine grains remain with the irradiation with the X-rays transmitting the drum 13 and the layer 14, from the inside of the drum 13 and generates carriers in the layer 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for forming a visible image on the surface of a flexible recording medium such as paper based on input information, such as a facsimile, a copier, The present invention relates to an image forming apparatus including a laser printer and the like.

[0002]

2. Description of the Related Art Conventionally, as this type of image forming apparatus,
There is an electronic copying machine using the Carlson method shown in FIG. In this electronic copying machine, an image is formed based on the input information as follows.

A drum 8 having a semiconductor layer called a photoconductor on its outer surface is rotated, and a corona charger 1 is used to
In the dark, this photoreceptor is charged using corona discharge. Next, the exposure device 2 irradiates the original document (input information) to be copied with light to form an electrostatic latent image having the same pattern as the original document on the photoconductor. Next, the developing device 3 sprinkles colored fine particles called toner, which are charged to the opposite polarity to the electrostatic latent image, onto the photoconductor. This toner is
Carbon black or the like is a resin fine powder having a particle size of several μm to 50 μm added to the surface or the whole thereof,
Magnetic powder of about 0.1 to 0.5 μm is dispersed in the resin. Next, the transfer device 4 transfers a copy image of the toner on the photoconductor onto a white recording paper by electrostatic force.
Next, the fixing device 5 heats and melts the toner, so that the toner permeates between the fibers of the recording paper and is fixed to the recording paper. Next, the photoconductor is destaticized by the static eliminator 6 constituting the cleaning device, the residual toner is cleaned by the cleaner 7 also constituting the cleaning device, and the photoconductor is returned to the initial state. This photoreceptor is repeatedly used. Such a series of processing is completed within a few seconds.

[0004]

However, in the above-mentioned conventional image forming apparatus, corona discharge is used in the charger 1 for charging the surface of the photoconductor and the static eliminator 6 for discharging the surface of the photoconductor. There was a problem. That is,
When corona discharge is used for charging and discharging the photoreceptor, ozone, NOx, and dust are generated during corona discharge, and the electrodes, which are the peripheral parts of the corona discharge part, are oxidized and the peripheral parts are deteriorated. It also causes a fire due to corona discharge. Further, the generation of ozone and NOx is not preferable in the global environment.

Therefore, the present invention has been made to solve the above problems, and does not adversely affect the surrounding environment at the time of use, has excellent use durability, and is excellent in safety. The purpose is to provide.

[0006]

That is, according to the present invention, a base body formed in a closed loop and moving along the closed loop, charging means for charging the surface of a photosensitive layer formed on the outer peripheral surface of the base body, and charging means Exposing means for exposing the surface of the photosensitive layer to form an electrostatic latent image corresponding to the image to be formed;
Developing means for attaching colored particles to the electrostatic latent image, transfer means for transferring the colored particles attached to the area of the electrostatic latent image to a recording medium, and fixing means for fixing the colored particles transferred to the recording medium. And a cleaning means for cleaning the colored fine particles remaining on the surface of the photosensitive layer, the above-mentioned substrate is formed of a light element, and the above-mentioned charging means transmits X through the substrate and the photosensitive layer. The X-ray generation means for charging is provided in a closed loop for ionizing the atmosphere on the surface of the photosensitive layer by the irradiation of rays and the electric field applying means for guiding the gas ions generated by this ionization to the surface of the photosensitive layer by an electric field. The cleaning means ionizes the atmosphere on the photosensitive layer where the colored fine particles remain by irradiation of X-rays that have passed through the substrate and the photosensitive layer, and also generates a carrier in the photosensitive layer. Characterized in that it consists erasing X-ray generating means provided within.

According to such an invention, the X-rays emitted from the charging X-ray generating means in the charging means pass through the substrate and generate gas ions on the photosensitive layer. The gas ions are guided to the surface of the photosensitive layer by the electric field generated by the electric field applying means, and the surface of the photosensitive layer is charged.

The X-rays emitted from the erasing X-ray generating means in the cleaning means also pass through the substrate and generate gas ions on the photosensitive layer. The colored ions remaining on the surface of the photosensitive layer are neutralized by the gas ions. The X-rays emitted from the erasing X-ray generating means generate carriers in the photosensitive layer. By this carrier, the electrostatic latent image formed on the photosensitive layer disappears.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of an image forming apparatus according to the present invention will be described below with reference to the accompanying drawings. In each figure, the same elements are designated by the same reference numerals and the description thereof will be omitted.

(First Embodiment) FIG. 1 shows a basic structure of an image forming apparatus according to the present embodiment. In FIG. 1, the same parts as those in FIG. 5 are designated by the same reference numerals. FIG. 2 is a perspective view showing the charging means 11 and the cleaning means 12, which are characteristic parts of this image forming apparatus. The image forming apparatus according to the present embodiment is characterized by a charging unit 11 and a cleaning unit 12, and each unit of the exposure unit 2, the developing unit 3, the transfer unit 4 and the fixing unit 5 is conventionally shown in FIG. The same one is used. A flexible recording medium such as paper is used for forming an image. Further, by changing the light irradiation control means as the exposure device 2, the image forming apparatus can be used as a copying machine, a facsimile, a laser printer, or the like. For example, the exposure device 2 includes a reading mechanism for reading an image from a document, and the reading mechanism allows irradiation of an optical signal through an optical system such as a lens and a mirror. Can be used as. Further, since the exposure device 2 is connected to a telephone line via a modem and is capable of emitting light corresponding to an electric signal from the modem, the image forming apparatus can be used as a facsimile. Furthermore,
Since the exposure device 2 is capable of irradiating a laser beam corresponding to an electric signal from the outside, the image forming apparatus can be used as a laser printer.

In FIG. 1, the substrate drum 13 is a light element,
For example, it is made of beryllium or carbon, and has a cylindrical shape to form a closed loop. This substrate drum 1
3 rotates about its cylindrical axis. This rotation causes the substrate drum 13 to move along this closed loop. Also,
A photosensitive layer 14 made of a semiconductor layer is formed on the outer surface of the closed loop of the substrate drum 13. The charging means 11 for charging the surface of the photosensitive layer 14 is composed of an X-ray tube 15 provided in the closed loop, an external fixed electrode 16 and a power supply 17. An X-ray shielding plate 20 is provided around the X-ray tube 15, and by this X-ray shielding means 20,
The X-rays emitted from the X-ray tube 15 are divided into X-rays 18a emitted toward the charging unit 11 and X-rays 18b emitted toward the cleaning unit 12. Substrate drum 1
Since 3 is formed of a light element, the X-rays 18a and 18b emitted from the X-ray tube 15 efficiently pass through the substrate drum 13 and the photosensitive layer 14. In addition, the fixed electrode 1 for charging
6 is made of a metal plate, and includes a substrate drum 13 and a photosensitive layer 14.
It is provided outside the closed loop on the surface of the photosensitive layer 14 so as to face the X-ray tube 15 via the. This charging fixed electrode 16
The voltage V ₀ is applied from the power source 17 to the. The fixed charging electrode 16 and the power supply 17 constitute an electric field applying means, and when a voltage is applied to the fixed charging electrode 16, an electric field is formed from the fixed charging electrode 16 toward the surface of the photosensitive layer 14.

Further, the X-ray tube 15 which constitutes the charging X-ray generating means also constitutes the erasing X-ray generating means of the charge eliminating portion which constitutes the cleaning means 12. In this cleaning means 12, a fixed erasing electrode 19 is provided outside the closed loop facing the X-ray tube 15 with the substrate drum 13 and the photosensitive layer 14 interposed therebetween. The fixed erasing electrode 19 is grounded. A brush cleaner 7 is provided at a position adjacent to the fixed electrode 19 for erasing in the direction in which the substrate drum 13 rotates.

The X-ray tube 15 constituting the charging and erasing X-ray generating means is provided along the central axis of the cylindrical substrate drum 13. In order to uniformly charge and remove the surface of the photosensitive layer 14, the X-ray tube 15 as described above
It is preferable to form the long type X-ray tube as in this embodiment, rather than arranging a plurality of short X-ray tubes along the central axis of the substrate drum 13. The X-ray tube 15 also generates X-rays in the energy range of 1 to 20 keV.

Next, the charging mechanism of the image forming apparatus having such a structure will be described with reference to FIG. In the figure, the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 3A, the atmosphere between the fixed charging electrode 16 and the photosensitive layer 14 in the charging means 11 is ionized by the irradiation of the X-ray 18a from the X-ray tube 15, and gas ions are emitted. Occurs. Positive polarity (+) of this gas ion
The charged gas ions are guided to the surface of the photosensitive layer 14 by the electric field generated by the electric field applying means. Therefore, the surface of the photosensitive layer 14 is charged with the positive charge 31. In the present embodiment, since the long type X-ray tube is used as the X-ray tube 15 as described above, the atmosphere on the surface of the photosensitive layer 14 is uniformly irradiated with X-rays and is sandwiched between the charging fixed electrodes 16. Gas ions are uniformly generated in the atmosphere. Therefore, the surface of the photosensitive layer 14 is uniformly charged with positive charge (+).

Further, the polarity of the charges charged on the surface of the photosensitive layer 14 can be set to a desired polarity by the polarity of the voltage applied to the fixed charging electrode 16. Therefore,
Depending on the polarities (+) and (-) of the toner used, the photosensitive layer 1
The polarity of the charges charged on the surface of No. 4 can be arbitrarily selected. Further, the surface potential of the photosensitive layer 14 can be set to a desired charging potential by selecting the voltage value applied to the fixed charging electrode 16. Therefore, by selecting this voltage value, it is possible to freely control the charge amount Q of the gas ions charged on the surface of the photosensitive layer 14. In addition, the photosensitive layer 1
Since the charging potential of No. 4 can be strictly controlled, the quality of the image formed is improved. The surface of the photosensitive layer 14 is charged by such a charging mechanism.

Next, the latent image charge erasing mechanism in the image forming apparatus will be described with reference to FIG.

The cleaning means 1 rotates from the fixing device 5
2 to the atmosphere on the photosensitive layer 14 moved to the substrate drum 13
And X-ray 18 from X-ray tube 15 transmitted through photosensitive layer 14
b is irradiated. The atmosphere on the photosensitive layer 14 is ionized by the irradiation of the X-rays 18b, and gas ions are generated. The positively charged gas ions of the generated gas ions are the negatively charged toner 32 remaining on the surface of the photosensitive layer 14.
Neutralize the electric charge of. At the same time, the X-ray tube 15
The X-rays 18b radiated from generate a carrier inside the photosensitive layer 14 to neutralize and erase the electrostatic latent image formed on the photosensitive layer 14. The neutralized residual toner on the photosensitive layer 14 is removed by the brush cleaner 7, and the surface of the photosensitive layer 14 is cleaned. By such an erasing mechanism, the surface of the photosensitive layer 14 is discharged and cleaned.

Next, the operation of the image forming apparatus according to this embodiment will be described.

In FIG. 1, first, while rotating the substrate drum 13, the charging means 11 is operated to uniformly charge the surface of the photosensitive layer 14 disposed on the outer surface of the substrate drum 13 by the above-described charging mechanism. It When the charged photosensitive layer 14 moves to the position of the exposure device 2 with the rotation of the substrate drum 13, an electrostatic latent image corresponding to the image to be formed upon receiving the light irradiation from the exposure device 2 is formed on the surface thereof. It is formed sequentially. Then, when the photosensitive layer 14 is moved to the developing device 3, toner, which is colored fine particles charged to a polarity different from that of the electrostatic latent image, is attached to the area of the electrostatic latent image. Black toner is usually used, but toners of other colors may be used. Further, when the photosensitive layer 14 moves to the transfer device 4, the recording medium is supplied between the substrate drum 13 and the transfer device 4 in synchronization with the movement, and the toner on the surface of the photosensitive layer 14 transfers to the recording medium 4. It is transferred by the electrostatic force from. After the transfer, the recording medium is transferred to the position of the fixing device 5, and the toner is fixed by heating in the fixing device 5, so that a desired image is formed on the recording medium. On the other hand, although the residual toner remains on the photosensitive layer 14 after the toner transfer, as described above, the cleaning unit 12 surely removes and cleans the charge, and the photosensitive layer 14 is returned to the initial state. Then, after the photosensitive layer 14 is charged again by the charging means 11,
The process of exposure, development, transfer and cleaning is repeated,
An image is formed.

(Second Embodiment) In the image forming apparatus according to the first embodiment, the case where the cylindrical substrate drum 13 is used as the substrate for moving the photosensitive layer 14 has been described.
The substrate is not limited to this. For example, as shown in FIG. 4, a sheet film belt 41 made of a light element formed in a closed loop shape may be used for this substrate. In this case, the photoreceptor 42 made of an organic optical semiconductor is formed on the surface of the sheet film belt 41 outside the closed loop, and the belt 41 is moved by the drive roller 43 along the closed loop. Then, the X-ray tube 15 constituting the X-ray generating means and the X-ray erasing means is provided in the closed loop as in the above embodiment. In addition, X via the belt 41 and the photoconductor 42
A charging fixed electrode 16 and an erasing fixed electrode 19 are provided outside the closed loop facing the wire tube 15 to configure the charging means 11 and the cleaning means 12, respectively. Even in such a configuration, the X-ray 18a emitted from the X-ray tube 15 charges the surface of the photoconductor 42 with electric charges 44. Also,
The X-ray 18b emitted from the X-ray tube 15 causes the photoconductor 4
2 The electric charge of the toner remaining on the surface is neutralized, and the electrostatic latent image remaining on the photoconductor 42 is erased. Therefore, even in such a configuration, the same effect as that of the first embodiment can be obtained.

The flash lamps 45a, 45b constitute an exposure device, and toner is sprinkled by the developing device 46 on the electrostatic latent image formed by the exposure device.
The accompanying image is transferred to the recording medium by the transfer device 47.

[0023]

As described above, according to the present invention, the X-rays emitted from the charging X-ray generating means in the non-contact charging means pass through the substrate to generate gas ions on the photosensitive layer. The gas ions are guided to the surface of the photosensitive layer by the electric field generated by the electric field applying means, and charge the surface of the photosensitive layer. Further, the X-rays emitted from the erasing X-ray generating means in the cleaning means also pass through the substrate and generate gas ions on the photosensitive layer. The gas ions neutralize the colored fine particles remaining on the surface of the photosensitive layer. Further, the X-rays emitted from the erasing X-ray generating means generate carriers in the photosensitive layer,
The carrier non-contact erases the electrostatic latent image formed on the photosensitive layer.

Therefore, the photosensitive layer can be charged and discharged without using conventional corona discharge, and therefore, the image forming apparatus according to the present invention does not generate ozone, NOx, or dust. Therefore, the problem that the electrodes, which are the peripheral components of the charging unit and the static eliminator, are oxidized and the peripheral components are deteriorated as in the conventional case is solved. In addition, there is no risk of fire due to corona discharge. Furthermore, an image forming apparatus that is favorable in terms of the global environment is realized.

Further, since the X-ray generating means is provided inside the closed loop of the base body, it is not necessary to provide a corona discharge portion which has to be installed outside the closed loop as in the conventional case. Therefore, a small image forming apparatus can be realized.

[Brief description of drawings]

FIG. 1 is a sectional view showing an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an outline of a charging unit and a cleaning unit of the image forming apparatus according to this embodiment.

FIG. 3 is a partially enlarged cross-sectional view showing a charging mechanism and an erasing mechanism of the image forming apparatus according to this embodiment.

FIG. 4 is a sectional view showing an image forming apparatus according to a modified example of this embodiment.

FIG. 5 is a diagram showing a basic configuration of a conventional image forming apparatus.

[Explanation of symbols]

11 ... Charging means, 12 ... Cleaning means, 13 ... Substrate drum, 14 ... Photosensitive layer, 15 ... X-ray tube, 16 ... Charging fixed electrode, 17 ... Power supply, 18a, b ... X-ray, 19 ... Erase fixed electrode , 20 ... X-ray shield.

Claims (5)

[Claims] 1. A substrate formed in a closed loop and moving along the closed loop, charging means for charging a photosensitive layer surface formed on an outer peripheral surface of the substrate, and exposing the charged photosensitive layer surface. An exposure unit that forms an electrostatic latent image corresponding to the image to be formed, a developing unit that adheres colored particles to the electrostatic latent image, and a colored particle that has adhered to the region of this electrostatic latent image is transferred to a recording medium. An image forming apparatus comprising: a transfer unit for fixing the colored fine particles transferred to the recording medium; a fixing unit for cleaning the colored fine particles remaining on the surface of the photosensitive layer; Is formed of a light element, and the charging means is provided with an X-ray generator for charging provided inside the closed loop that ionizes the atmosphere on the surface of the photosensitive layer by irradiation of X-rays that have passed through the substrate and the photosensitive layer. And an electric field applying unit that guides gas ions generated by this ionization to the surface of the photosensitive layer by an electric field. The cleaning unit causes the colored fine particles to remain by irradiation of X-rays that have passed through the base and the photosensitive layer. An erasing X provided in the closed loop for ionizing the atmosphere on the photosensitive layer and generating carriers in the photosensitive layer.
An image forming apparatus comprising a line generating means. 2. The image forming apparatus according to claim 1, wherein the charging X-ray generating unit and the erasing X-ray generating unit are constituted by the same X-ray generating unit. 3. The electric field applying means applies an electric voltage to the electrode provided outside the closed loop on the surface of the photosensitive layer facing the X-ray generating means through the base and the photosensitive layer. The image forming apparatus according to claim 1, further comprising a power supply. 4. The image forming apparatus according to claim 1, wherein the substrate is a cylindrical drum. 5. The image forming apparatus according to claim 1, wherein the substrate is a closed loop belt.