JPS5981660A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To prevent deterioration of a picture during transfer and to improve transfer efficiency by providing an endless inductive belt which rotates and moves so that a part thereof contacts an about half circumference of a photosensitive drum and the remainder is separated from the photosensitive drum. CONSTITUTION:The inductive belt 2 rotates and moves while holding proper tension so that part of it contacts the about half crcumference of the photosensitive drum 1 and the other is separated from the drum. An electrostatic latent image formed on the drum 1 by the exposure of an optical system 5 through the transparent inductive belt 2 is developed by a developing device 6 and charged toner 7 is attracted to the electrostatic latent image through the inductive belt 2 to stick thereto. The toner 7 sticking to the inductive belt 2 is sent to a transfer position and attracted electrostatically from the reverse surface of a transfer material 8 and at the same time, the inductive belt 2 is separated from the photosensitive drum 1, so that force which attrats the toner 7 to the photosensitive drum 1 through the inductive belt 2 is weakened, so that the toner 7 sticks to the transfer material 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic apparatus used as a photographic camera or a printer.

Since Vt, in electrophotographic apparatuses, six processes of charging, exposure, transfer, and zero/neutralization are performed on a photosensitive drum rotating at a constant speed.

Among the processes of Koori et al., the transfer JJ process has problems such as deterioration of image quality and transfer efficiency of 11'l at a rate of 1°C. This is noticeable on platforms that use magnetic toner.In the transfer process, the toner on the photosensitive drum is electrostatically attracted from the back side of the transfer material such as plain paper using corona ions or an electric field roller. If the electric field is made too strong, the toner will scatter, deteriorating the transferred image, and conversely, the transfer efficiency will decrease.

The present invention 1 was created to solve these drawbacks, and aims to prevent the deterioration of the image during transfer and improve the transfer efficiency. A part of the dielectric belt is tightly attached to about half the circumference of the photosensitive drum, and the other part is stretched so that it rotates by friction with the photosensitive drum.
After forming an electrostatic latent image on the photosensitive drum or old belt, development is performed at a position where the photosensitive drum and dielectric belt are in close contact to attract and adhere the toner onto the dielectric belt, and It is characterized in that the toner on the dielectric belt is transferred to a transfer material such as paper at a position where the photosensitive drum and the dielectric belt are separated.

To explain the following with reference to the drawings, Fig. 1 is a side view showing one embodiment of the present invention. It has a structure coated with an optical semiconductor such as Se or CdS.

Reference numeral 2 denotes a dielectric belt, which is formed into an end shape using a transparent polyester film or the like having a thickness of about 10μ771 to 200μ+1L as a composite material, and has a width almost equal to the length of the photosensitive drum 1 in the direction of the heel. ing. A portion of this dielectric belt 2 tightly covers approximately half the circumference of the photosensitive drum 1,
The other parts are wound around the photosensitive drum 1 and rollers 3a, 3b, etc., which are arranged near the photosensitive drum 1 so as to be separated from the photosensitive drum 1, and maintain appropriate tension, and the photosensitive drum 1 is When rotating in direction a, friction causes it to move one turn at the same speed.

4 is a charger such as a corona radiator, 5 is an optical system for dew zero,
6 is a developing device, 1 is a toner, 8 is a transfer material such as plain paper, 9 is a transfer rj such as a corona discharger or an electric field roller, 10 is a light source for static elimination, and 11 is a cleaning unit, where the charging The yC source 10 for FMI is disposed between the photosensitive drum 1 and the dielectric belt 2, and the exposure optical system 5 and the developing device 6 are disposed between the photosensitive drum 1 and the dielectric belt 2. Placed so as to face the surface of the sex belt 2
I'm here. The transfer d9 is arranged so as to face the surface of the 6δ torturous belt 2 at a position where the photosensitive drum 1 and the dielectric belt 2 are in front of each other. , 3b, C 12 is provided so as to be in contact with the surface of the dielectric belt 20 at a position between 3b and 3b.
, l:'s belt, 13 is -4 of this conveyor belt 12
1111IK is a fixing device equipped with fl.

A little bit about the action of A4'4 mentioned above.
Then, the photosensitive drum 1 first rotates at a constant speed in the direction of the arrow a, and after being uniformly charged by the charger 4, the photosensitive drum 1 is turned on by the optical system 5.
An electrostatic latent image is formed on the photosensitive drum 1. Exposure at this time is performed via a transparent dielectric belt 2, and the electrostatic latent image is formed on the photosensitive drum 1. Since the ♂l sleepability belt 2 allows electric lines of force to pass through it, when the developing device 6 performs further development in the next step, the toner 7 that has retained the electric charge will be statically transferred through the ♂l sleepability belt 2. Attracted and attached to the crystal image. However, in the case of reversal development, the usability of the charge held by the toner 1 is different from that shown in the figure, and the toner 1 is electrostatically attracted to the charge generated on the conductive substrate of the photosensitive drum 1.

In this way, the toner 7r attached to the dielectric belt 2,
As the photosensitive drum 1 and the dielectric belt 2 rotate, the transfer material 8 is sent to the transfer device if as shown in FIG. and t411dj. Note that the electric field and charge from the transfer device 9 at this time have a polarity different from the charge held by the toner 7. At the same time as the electrostatic attraction by the transfer device 9, the dielectric belt 2 is separated from the photosensitive drum 1, so that the toner I is transferred through the conductive belt 2.
When the force being attracted to the photosensitive drum 1 becomes weaker, the l.ner 7 adheres to the transfer material 8. At this time, the dielectric belt 2 and the transfer material 8 are mechanically in close contact with each other (~), so the transfer suction force remains unchanged, and the number of toner γ ponds is reduced. The particles are peeled off from the belt 2 and transferred to the conveyor belt 121, and then transferred to the conveyor belt 12 by this general conveyor belt 12.
Although the transfer materials 8 and 9j are fed in the direction of the arrow, the attraction force between the transfer belt 2 and the conveyor belt 2 is weak, and since the transfer materials 8 and 9j are electrostatically attracted to the conveyor belt 12, separation is performed reliably. , since the toner T is also electrostatically attracted to the transfer material 8 and is deposited on the transfer material 8, '
L5 The amount of toner 1 remaining on the ftj belt 2 is very small.
Ru.

If it is sent in the direction of the arrow by the bush feeding belt 12, the shift j I (
After the toner 7 is fixed by the fixing device 13, the 'J' material 8 is outputted 2〇 On the other hand, the photosensitive drum 1 separated from the Mi4 belt 2 is illuminated with static eliminating light by the static eliminating light source 10. Then, the dielectric belt 2 peels off the transfer material 8 1ηj#v:
, the residual toner is removed by the cleaning unit 11.

Note that the present invention is not limited to the above-mentioned embodiments,
For example, the electrostatic latent image may be formed on a dielectric film covering the photosensitive drum, or it may also be effectively formed on a dielectric belt.

In addition, since the exposure optical system uses a recently developed LED array or laser scanning device and n is small, it is also possible to place it between the photosensitive drum and the dielectric belt. The ability to form an electrostatic latent image on the drum allows the dielectric belt to be used even if it is opaque.

As explained above, this method attracts and adheres toner to a dielectric belt that is in close contact with a photosensitive drum, and at the same time attracts the toner on the dielectric belt from the back side of the transfer material during transfer. Because it is separated from the photosensitive drum, it is possible to suppress the toner scattering that occurs during transfer when toner is directly attached to the conventional photosensitive drum, and as a result, even when using magnetic toner, it is possible to reduce the It has the effect of increasing transfer efficiency and improving image quality.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an embodiment of an electrophotographic apparatus according to the present invention, and FIG. 2 is an enlarged cross-sectional view of the vicinity of the transfer position in FIG. 1.0 1...Photosensitive drum 2...Dielectric bell ) 3a. 3b...Roller 4...Charger 5...Exposure optical system 6...Developer 7...Toner 8...Transfer material 9...Transfer device patent applicant Oki Neki Kogyo Co., Ltd. Agent: Patent attorney Kanakura Written amendment to commercial and industrial procedures (spontaneous) September 1, 1980 Director of the Patent Office Kazuo Wakasugi 1, Indication of case 1981 Patent Application No. 191766 2,
Title of the invention Electrophotographic device 3, relationship to the case of the person making the amendment Patent applicant address 1-7-12 Toranomon, Minato-ku, Tokyo Name (029) Oki Electric Industry Co., Ltd. Representative Nankai Hashimoto 4, Representative Attorney 5, weight 6 of the amendment order, description subject to amendment “t・;°C in the scope of claims”
, Contents of the amendment (2) The scope of the claims is amended as follows. 1. A photosensitive drum and an endless dog dielectric stretched around half of the photosensitive drum so that part of it is in close contact with the photosensitive drum, and the pond part is separated from the photosensitive drum and rotates due to friction with the photosensitive drum. an electrostatic latent image is formed on the photosensitive drum or the dielectric belt by the exposure optical system, and the gelopalum and the dielectric belt are formed on the photosensitive drum or the dielectric belt. The toner is then layered onto the dielectric belt by developing it with a developing device.
An electrophotographic apparatus characterized in that a transfer device transfers toner on a dielectric belt to a transfer material at a position where a photosensitive drum and a dielectric belt are separated. 2. In the 9th line of page 5 of the specification, the phrase ``J〆fog light, transfer and'' is corrected to ``exposure, phenomenon, transfer, cleaning and''.

Claims (1)

[Claims] 1. A photosensitive drum, and an endless dielectric belt stretched around half the circumference of the photosensitive drum so that a part is in close contact with the photosensitive drum and the other part is separated from the photosensitive drum and rotates due to friction with the photosensitive drum. and an exposure optical system, a developing device, and a transfer device, an electrostatic layer image is formed on the photosensitive drum or the dielectric belt by the exposure optical system, and the photosensitive drum and the dielectric belt are in close contact with each other. At a position where the photosensitive drum and the dielectric belt are separated, the toner is developed by a developing device and deposited on the dielectric belt, and at a point where the photosensitive drum and the dielectric belt are separated, a transfer device is used to transfer the toner from the dielectric belt to the transfer material. An electrophotographic device whose special feature is transfer.