JPS623947B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an image-forming particle dispersing device for an electrophotographic apparatus, and in particular, image-forming particles are electrostatically attached to the surface of a photoreceptor containing a photoconductive substance, etc. The surface and the image forming particles are exposed imagewise to reduce or eliminate the charge in the light irradiated area of the photosensitive surface, and the image forming particles whose electrostatic attraction between the photosensitive surface has been reduced or eliminated are removed from the photosensitive member. An object of the present invention is to provide an electrophotographic apparatus that is particularly effective in an electrophotographic system in which an image is formed using residual particles.

In this type of electrophotographic device, in order to obtain a clear image with good resolution and no fog, it is necessary to scatter image forming particles in a single layer on the photosensitive surface before image exposure, and without any gaps between the particles. .

Conventionally, a method shown in FIG. 1 has been proposed as a scattering device for electrostatically depositing image forming particles onto the surface of a photoreceptor. In FIG. 1, when a photoreceptor b is charged by a charger a, a gate d of a hopper c opens and image forming particles e are scattered onto the photoreceptor b. However, in this case, if the image forming particles are to be densely adhered to the photoreceptor b, a large amount of image forming particles will be transferred to the gate d.
It is necessary to emit more particles and collect most of the particles into the collection housing f, which increases the amount of image forming particles consumed. Furthermore, when the photoreceptor is transported at high speed, the spraying ability is significantly reduced. In order to reduce the amount of image forming particles consumed, a method has also been proposed in which the image forming particles that have fallen into the collection housing f are returned to the hopper c using a circulation means, but in this case, the image forming particles are agitated by the circulation means. As a result, the image forming particles are damaged, resulting in poor light transmittance and electrical conductivity of the image forming particles, which causes fogging of images after development.

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, it is an object of the present invention to provide a spraying device that sprays image forming particles onto a photoreceptor in a single layer and densely without gaps between the particles.

Another object of the present invention is to provide a dispersion device that consumes less image forming particles. Still another object of the present invention is to provide a spraying device that can sufficiently follow the high-speed conveyance of photoreceptors.

Still another object of the present invention is to provide a spraying device that does not damage image forming particles.

Still another object of the present invention is to provide a spraying device capable of spraying image forming particles only onto the image forming area of a photoreceptor.

The details of the present invention will be explained below with reference to the drawings. FIG. 2 is a schematic diagram of a color electrophotographic apparatus showing an embodiment of the present invention, in which a photoreceptor 1 is supplied from a supply roll 2 and taken up by a take-up roll 3. The photoreceptor 1 supplied from the supply roll 2 is supported under tension by a drive roller 4 and driven rollers 5, 6, 7, and 8. Photoreceptor 1 is first uniformly charged by charger 9 . The image forming particle scattering device includes a multi-stylus electrode 1 as a discharge electrode.
0, image forming particle guide plate 11, image forming particle supply means 13 to the multi-stylus electrode 10,
and a layering means for layering the image forming particles scattered on the photoreceptor 1 by the multi-stylus electrode 10, and a collection housing 12 for receiving the image forming particles. The supply means, generally indicated at 13, includes a hopper 15 for storing imaging particles 14.
and a diaphragm 16 tilted at an angle such that the image forming particles are supplied to the multi-stylus electrode 10 when vibrated, and the image forming particles are normally stationary.
, a vibrator 17 that vibrates the diaphragm 16, and a gate 18 that is installed at a predetermined distance from the diaphragm 16 and adjusts the amount of image forming particles supplied to the multi-stylus electrode 10. .

The image-forming particles stored in the hopper 15 are microparticles with a diameter of about 5 to 50 μm, and are light-transmissive image-forming particles that contain a heat-sublimable dye that develops a yellow color and that transmit blue-violet light. , light-transmitting image forming particles containing a heat-sublimable dye that develops a magenta color and transmitting green light, and a light-transmitting image containing a heat-sublimable dye that develops a cyan color and transmitting red light. It is a mixture of three types of image forming particles.

The angle of inclination of the diaphragm 16 depends on the fluidity of the image forming particles, but is suitably between 5 degrees and 45 degrees. The layering means comprises a vibrating roller 19 and a suction box 20. The vibration roller 19 has a projection at at least one location on its outer periphery, is arranged so that at least the projection comes into contact with the back surface of the photoreceptor 1, and is rotated by a rotation means (not shown). The suction box 20 is arranged close to the photoreceptor 1 and sucks the image forming particles removed from the photoreceptor 1 by the vibrating roller 19 . The image forming particles scattered by the multi-stylus electrode 10 are attached to the photoreceptor 1 in a layered manner. Compared to the first layer of image forming particles that directly adhere to the photoreceptor 1 by electrostatic force, the image forming particles that do not directly adhere to the photoreceptor 1 but are stacked on top of other image forming particles have a weaker adhesion force. Therefore, when appropriate vibration is applied to the photoreceptor 1 by setting the rotational speed of the vibrating roller 19, the size of the protrusion, and the tension of the photoreceptor 1, the image forming particles of the first layer remain on the photoreceptor 1. , the image forming particles of the second and higher layers are removed from the photoreceptor 1.

The multi-stylus electrode 10 faces the photoreceptor 1 with a predetermined distance therebetween. Figure 3 shows details of the multi-stylus electrode. multi stylus 10
are bonded to an electrically insulating substrate 21, the tips of the electrodes are aligned in a line, and the other ends are combined into one and connected to a power source (not shown). In the example, the multi-stylus wire diameter is 60μ, and the electrode wire alignment density is 8dot/mm.
(pitch 125μ). A voltage having a polarity opposite to the charge applied to the photoreceptor 1 by the charger 9 is applied to the multi-stylus 10 . When a voltage is applied to the multi-stylus electrode 10, a corona ion flow is generated between the photoreceptor 1 and the tip of the multi-stylus electrode, and image forming particles are scattered onto the photoreceptor 1.
Since the image forming particles are charged with a polarity opposite to that charged on the photoreceptor 1 by the multi-stylus 10, they easily adhere to the photoreceptor 1 and can be sufficiently dispersed even when the photoreceptor 1 is conveyed at high speed. . Furthermore, since the multi-stylus electrode is formed with a minute pitch of 125μ between each stylus, even if the image forming particles have a diameter of 5μ to 50μ,
All the particles are immediately charged, and since the corona ion flow is uniform in the width direction of the photoreceptor 1, uneven distribution does not occur. Note that the electrode density of the multi-stylus does not necessarily need to be 8 dots/mm, but the higher the electrode density, the more uniform the corona ion flow will be.

The guide plate 11 is installed below the multi-stylus electrode 10 in close proximity to the photoreceptor 1 or in contact with a portion thereof, and stops or slows down the flow of image forming particles supplied from the diaphragm 16. , increasing the adhesion rate of image forming particles to the photoreceptor 1 and reducing the amount of image forming particles consumed;
This has the effect of lowering the voltage applied to the multi-stylus electrode. Although the guide plate 11 has the above-mentioned effect, it is not necessarily necessary, and the multi-stylus electrode 10 alone can perform a sufficiently good dispersion. The voltage applied to the multi-stylus electrode 10 depends on the gap between the multi-stylus electrode and the photoreceptor 1. If the gap is 1mm, without the guide plate 11
500V to 1KV is suitable, and if a guide plate is installed
100V~1KV is suitable.

A color original 22 is placed on a transparent support 23, and the support 23, a light source 24, and a reflecting mirror 2
Optical system 2 with 5, 26, lens 27, and slit 28
9, the light supplied by the light source 24 is reflected by the color original 22 and irradiates the photoreceptor 1 and image forming particles along the path indicated by the dotted line L, thereby performing image exposure. . At this time, photoreceptor 1
A guide 30 is placed in contact with the back surface of the photoreceptor 1 and facing the slit 28, which maintains the flatness of the photoreceptor 1 during exposure and prevents vibrations from being transmitted to the photoreceptor 1 in the exposure area during the next development process. Do it like this.

The photoreceptor 1, which has been transported in the direction of arrow N until the exposure step, is transported in the direction of arrow M when the exposure step is completed. The developing device includes a vibrating roller 31 that contacts the back surface of the photoreceptor 1 and a suction box 32.
The vibration roller 31 may have the same shape as the vibration roller 19 of the layer forming means.

Receiving sheets 34 are stacked on the paper feed cassette 33, and the uppermost receiving sheet is in contact with a feed-out roller 35. A paper feed guide 37 is arranged between the transfer roller 36 and the paper feed cassette 33, which are pressed against the photoreceptor 1 with a predetermined pressure.
The receiving sheet 34 is designed to be conveyed smoothly. Fuser 38 heats the imaging particles transferred onto the receiving sheet by transfer roller 36;
A colored image of the sublimable dye contained in the image forming particles is obtained on the surface of the receiving sheet. Image forming particles slightly remaining on the photoreceptor 1 after transfer are removed by a cleaning device 39.
The image forming particles after sublimation of the heat sublimable dye adhering to the receiving sheet are removed by a cleaning device 40 .

If a copy button (not shown) is now pressed, the photoreceptor 1 begins to move in the direction of arrow N and is charged by the charger 9. When the charged photoconductor 1 reaches the dispersion device 13, the multi-stylus electrode 1
0, the guide plate 11 moves in the direction of arrow P and approaches the photoreceptor 1. At the same time, the vibrator 17 is activated, the image forming particles on the diaphragm 16 are supplied to the multi-stylus electrode 10, and a voltage is applied to the multi-stylus electrode 10, so that the image forming particles are scattered onto the photoreceptor 1. Multi stylus electrode 1
Since the image forming particles dispersed in step 0 are attached to the photoreceptor 1 in a layered manner, they are layered by the layering means. Sensor light 1 with image forming particles uniformly scattered
When the optical system reaches the exposure position, the optical system moves at half the speed of the photoreceptor 1 and scans the color original 22, and the image forming particles and the photoreceptor 1 are irradiated with light, and the color original 22 is scanned.
Light is transmitted through the image forming particles according to the second color, and the electrostatic charge is reduced or removed in the area of the photoreceptor to which the image forming particles through which the light has passed are attached. When the image exposure is completed, the photoreceptor 1 is moved in the direction of the arrow M, and the vibration roller 31 vibrates the back surface of the photoreceptor 1 in the developing process, so that the electrostatic attraction between the photoreceptor 1 and the photoreceptor 1 is reduced or The removed image forming particles are removed from the photoreceptor 1, and an image is formed using the remaining particles.

Next, the image formed by the remaining particles is sent in the direction of the transfer roller, but at this time, the multi-stylus electrode 10
Since the guide plate 11 is located away from the photoreceptor 1, the image forming particles present on the guide plate 11 do not disturb the image on the photoreceptor 1. The residual particle image is transferred to a receiver sheet by transfer roller 36. After the transfer, the receiving sheet is conveyed to the fixing device 40, and a color image is developed by the heat sublimable dye contained in the image forming particles.

In the above embodiment, the vibrating roller 19 and the suction box 20 constitute the layering means, but the suction box 20 is not necessarily necessary, and the vibrating roller 19
The image forming particles removed from the photoreceptor 1 by the photoreceptor 1 are allowed to fall down the slope formed by the photoreceptor 1, and
You can store it above 1. Alternatively, a method may be applied in which image forming particles are layered by applying wind force to them.

As described above, according to the electrophotographic apparatus of the present invention, image forming particles can be more evenly distributed on the photoreceptor,
Moreover, even if the photoreceptor is transported at high speed, the dispersion can be sufficiently followed. Further, there are advantages in that the dispersion of the image forming particles can be easily started and stopped, and the amount of image forming particles consumed can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of the main parts of a conventional example, FIG. 2 is a diagram showing the construction of an embodiment of the electrophotographic apparatus of the present invention, and FIG. 3 is a perspective view of the main parts. DESCRIPTION OF SYMBOLS 1... Photoreceptor, 9... Charger, 10... Multi-stylus electrode, 11... Guide plate, 13... Supply means, 14... Image forming particles, 15... Hopper, 16... Vibration plate, 17 ...vibrator, 1
9... Vibration roller, 20... Suction box.

Claims (1)

[Scope of Claims] 1. In an electrophotographic apparatus that performs exposure and development after uniformly scattering image forming particles on a photoreceptor containing a photoconductive substance, a charging method that uniformly charges the photoreceptor. a multi-stylus-shaped discharge electrode provided near the photoconductor at a predetermined interval; a supply means for supplying the image forming particles to the discharge electrode; It is not sufficient to remove the image forming particles from the photoreceptor, but it is sufficient to remove the image forming particles that are stacked in two or more layers on top of the image forming particles directly adhered to the photoreceptor. An electrophotographic apparatus comprising a layering means for applying force to image forming particles, the charger, the discharge electrode, and the layering means being arranged in sequence in the direction of transport of the photoreceptor. 2. The layering means comprises a vibrating roller having a protrusion at at least one location on the outer periphery and disposed such that at least the protrusion comes into contact with the back surface of the photoreceptor. Electrophotographic equipment.