JPS5840565A - image forming device - Google Patents

Abstract

PURPOSE:To obtain a powder picture of high quality with high speed using comparatively weak corona for image transfer, by rendering an endless belt-like screen photoreceptor opposite to an endlss belt-like insulating belt. CONSTITUTION:When the electrostatic latent image is formed on an endless belt- like screen photoreceptor 8, and a new latent image corresponding to said image is formed on an endless insulating belt in parallel to the photoreceptor 8 by means of modification corona discharger 21. This latent image is developed with a magnetic toner 27 over a comparatively long distance with a developing belt 33 hang with magnetic rollers 31, 32, transferred to transfer paper with transfer corona discharger 42, and fixed with fixing rollers 43, 44. Since the photoreceptor 8 and the belt 15 are arranged in parallel opposite to each other, modification distance can be extended, so a comparatively weak modification corona discharge can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming apparatus using means for modulating a uniform ion flow, such as a screen-like photoreceptor or an aperture board.

Means conventionally known as ion modulation means include:
There is a screen-shaped photoreceptor that uses a conductive layer, a photoconductive layer, and a surface insulating layer. Further, as a modulation means using an electric signal, there is an aperture board which is used by providing independent electrode layers on both sides of a row of openings in an insulating layer and applying a signal voltage to these electrodes.

Among the above-mentioned modulation means, some screen-like photoreceptors include a photoreceptor having a surface insulating layer, an underlying photoconductive layer, and a conductive substrate disclosed in Japanese Patent Publication No. 54-27144, which is a photoreceptor that is photosensitive on an insulating material. The l1iIi image due to modulation from the same latent image of the body is 1
Some are modulated up to 00 times. Therefore, in order to make multiple copies, one electrostatic latent image only needs to be created once on the screen-like photoreceptor, and thus J[I
It has the advantage that up to 100 copies can be made continuously by irradiating il only once. If more than 100 copies are required, the screen-like photoreceptor is subjected to a second exposure to re-engrav the latent image. Therefore, in the case of copies of 100 sheets or less, the time-consuming repeated scanning of the original by the copying optical system is omitted, which reduces the time required to make copies, making it suitable for making very high-speed continuous copies. ing.

However, the disadvantage of this conventional method is that in order to maintain a clear image on the insulated drum that is the image receptor, the width of the area that modulates the ion flow from the screen-like photoreceptor to the insulated drum that is the image receptor must be kept narrow. It was Bananaiko E. For faster modulation speeds, this means using a modulating corona with a very strong voltage applied. However, on the other hand, the modulating corona cannot be made so strong that sparks are to be feared. For this reason, modulating image quality and transfer tLVC limits are set.

The purpose of the present invention is to speed up image creation! The purpose of this method is to create high-quality copies with a relatively weak transfer corona without causing negative effects. Furthermore, the present invention provides an apparatus that can make multiple copies at high speed and form high-quality images.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of a device showing an embodiment of the present invention. The glass plate 1 serves as an original table and is moved back and forth in the direction of the arrow 2, and on the left side is moved to a position 1', on which the original 6 to be copied, in this case a book, is placed. Lighting device 4
A striped area 5 on the document surface is exposed. The original image is exposed onto a screen-like photoreceptor B in zone A by an optical system 6 using a short focus element array in which this striped area is placed behind a prism. The photoreceptor 8 rotates in the direction of the arrow 12 on this endless belt-like rotating shaft. The ZONEM screen-like photoreceptor 8 is uniformly electrostatically charged by a charged corona 13 before image exposure, and an electrostatic latent image corresponding to the original is formed on the photoreceptor 8 by subsequent exposure of the original image.

On the other hand, in area B, an insulating bell (15) made of an insulating material, which is an image receptor, is placed parallel to the screen-like photoreceptor B, and this endless bell (15) is I"-2-16°17.18,190
The rotor rotates in the direction of arrow 20 in synchronization with the photoreceptor 8E.

A new sI image is formed on the insulating belt by the modulating corona discharger 21 in correspondence with the electrostatic latent image on the screen-like photoreceptor. The insulating bell (15) passes along the development device, designated as a whole by 25, through the flywheels of the rollers 18,19.

The developer device 25 is provided as a hollow cylinder and consists of a storage container 26 in which an insulating magnetic toner 27 is placed. By the agitation member 28 rotating in the direction of the arrow 29, the toner 27 passes through the opening 6o and flows into the two rows. -51
, 52 and is transported near the tail 55. This one-51.52 can be a magnetic roller carrying alternating north and south poles. Bell) 65
are aligned in the direction of arrow 64, conveying toner to the insulating belt along a relatively long transfer distance. The toner on this belt 55 is rapidly rotated for sufficient time to be transferred onto the imagewise electrostatically charged surface portion of the insulating belt 15, so that the toner on the belt 15 is transferred to a high quality document. A powder image results.

55 of the developing device 25 is a magnetic pole piece disposed in the width direction of Bel>55, to which an alternating current voltage is applied or the toner with weak adhesion to the belt 15 is removed.
8g, and works to prevent toner from being deposited on areas of the belt 15 that are completely uncharged, thus ensuring a clear contrast on the finished copy and preventing the fogging phenomenon. Avoid making the background too dark.

For the developed toner image on the belt 15, the plastic paper is taken out from the storage case 40, and the insulating belt 15 is placed in the area C along the line 41 represented by a dashed line.
sent to. Then, by the transfer corona 42, Bell) 1
The toner image on 5 is transferred onto copy paper. Thereafter, the copy paper is pressed and fixed by the levers of two fixing rollers 45 and 44, and the completed copy is discharged onto the storage tray 45.

According to the present invention, when the above-described structure is delivered to the screen-like photoreceptor 8, ions are modulated onto the MB return insulating belt using a single electrostatic latent image corresponding to the original 6, and the number of sheets within 100 sheets is In the case of copying, continuous copies can be obtained an exponential number of times in L to be created.

Δ The above apparatus is provided with a neutralization (AC) corner 50 in addition to the charging corona 15 for removing residual charges on the photoreceptor 8 when a predetermined copying process is completed.

On the other hand, each time a copy is made, a new copy is placed on the insulating belt 15 from the screen-like photoreceptor 8 to the belt 1.
5, so that after the toner on this belt 15 is transferred, it is erased by the neutralizing (AC) corona 51, so that the length of the body 8 and the belt 15 is exactly Even if they do not match one after another and have a relative shift from each other, no double image is generated by the modulated ions on the insulating belt 15. Further, the above-mentioned device includes a cleaning device 52 for wiping off remaining toner before static elimination by the static eliminating corona 51.
〇By the way, the photoreceptor 8 and the belt 15
It is advantageous for the belt 66 supporting the toner to be seamless. That is, even if a shift occurs in the relative movement positions of the photoreceptor or the belt, an interfering seam position will not appear on the completed copy.

Reference numeral 60 in the figure indicates a blower that sucks air inside the device and pushes it out through the ozone filter 61. This air blower is used to cool the device and when the ozone concentration in the air inside the device becomes high during high-speed copying process, this filter 61 is used to cool the device.
It works to purify the air containing ozone.

According to the above example using the screen-like photoreceptor of the present invention,
In the modulation zone, the screen-like photoconductor and the insulating belt, which is the image receptor, are arranged plane-parallel to each other, making it possible to increase the distance of the modulation area. Therefore, by using a relatively weak modulation corona, It is possible to protect the latent image and prevent deterioration of the latent image.

Furthermore, in one transfer zone, the lines of force run in parallel, so a clear copy can be obtained, and the modulation area is long, so the modulation speed can be increased.

It should be noted that increasing the modulation speed alone is not sufficient to ensure rapid operation when making copies. Furthermore, consideration must be given to ensuring that the development of the latent image on the insulating bell F by modulation is rapid and sufficient.

To this end, the development device of the invention has belts for supporting the toner which convey the toner particles from the storage container to an insulating belt and which accompany the toner particles in parallel opposition on a portion of the length of this insulating belt. This provides sufficient time for the electrostatic insulating belt to be transferred to the position where it carries the four charges.

With the above-described arrangement of the present invention, it is possible to provide a copying device with a minimal structure that allows a plurality of high-quality copies to be made in succession very quickly.

As a modification of the present invention, in addition to exposing the original image on the original platen to the irradiation of optical information to the screen-like photoreceptor,
LED strings arranged in the width direction of the photoreceptor may also be used. Furthermore, the same effect as the screen-like photoreceptor can be obtained by arranging a plurality of rows of aperture boards in the width direction of the insulating belt instead of the screen-like photoreceptor.

[Brief explanation of drawings]

FIG. 1 shows a sectional view of essential parts of an image forming apparatus showing an embodiment of the present invention. In the figure, 8 is a screen-like photoreceptor, 15 is an insulating belt, 26 is a developing device, and 36 is a toner support bell F.

Claims (1)

[Claims] (1) A modulation means forming a plane at a modulation position, an endless image receptor receiving the ion flow modulated by the modulation means and forming a plane at the modulation position and the development position, and at the development position of the image receptor. An image forming apparatus that includes an endless toner conveying means that moves in parallel with an image receptor.