JPS63225279A - Method and device for forming image - Google Patents

Abstract

PURPOSE:To permit formation of an image at high resolution by electrically charging a toner in such a manner that the charge potential of the toner adhering on a photosensitive body is reversed and removing said toner from the photosensitive body, then destaticizing the photosensitive body. CONSTITUTION:The toner T in the part except the image to be transferred which is not transferred in the part of a transfer device 39 is progressed in the form of the residual toner held adhered to the surface of an OPC belt 21 and is reverse charged from negative to positive potential by the corona charge effect of a charger 25. The residual toner on the belt 21 charged to the positive potential in such a manner is attracted to a magnetic brush impressed with a negative bias in the part of a next developing device 26 and is recovered into the device 26. The residual toner is, therefore, completely removed from the surface of the belt 21. The belt 21 cleaned in such a manner is exposed over the entire surface during the passage through an exposing device 24 and is partially removed of the residual potential. The belt is then progressed so as to be used for fresh printing. The image having the extremely high resolution is thereby formed on paper 40.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention is carried out by electrophotographic deposition. ? 1iTii & forming method for forming images on 111 bodies, and equipment.

[Conventional technology]

A conventional image forming apparatus for this scale is formed as shown in FIG. 4, which shows a typical example thereof.

This conventional example uses an endless OPC belt 1 as the photoreceptor. This OPC belt 1 is
, 2, supported by the large roller 3 and the drive roller 4, and is moved by the drive roller 4 in the direction of the arrow in the figure. A +M posthumous section is arranged around this OPC bell l-1 to form an image on a recording medium such as paper. ! First, 9:) The surface of the OPC bell 1-1 is charged to a uniform positive potential by the Corop charging action of the electric device 5. Next, an electrostatic latent image according to the printing pattern etc. is written on the OPC belt 1 by the optical writing unit 6, and then on the OPC belt [・1,! ) Included static PL
By development=7, a dove electrically charged to a negative potential is selectively attached to the latent image portion to form an image of 1 to no. Then, this double-first strategy ended up turning into the progress of oPC belt 1? When reaching the part 7 and 8, the image on the OPC belt 1 is transferred onto the paper 9 by the electrostatic attraction between the transfer device 3 and an image is formed. (After that, the paper 9 is peeled off from the OPC bell 1 and conveyed to the fixing device 10.
The toner image is fixed onto the paper 9 using heat or 11 force, and the toner image is fixed on the paper 9 (not shown).
Put IJ paper on top. On the other hand, transcription: 58 portions were passed through 3 ITJ. The static eliminator 11 on the PCC belt 1 eliminates residual toner on the oPC belt 1, and then the cleaner 12 cleans the residual toner adhering to the oPC belt 1.

[Problems that the invention attempts to solve]

However, in the conventional example (by the optical unit O), 1! is sent to the OPC belt 1! :Although the electrostatic latent image to be inserted is formed at an extremely high resolution of 73M, it is still
When applying toner to the electrostatic latent image on the belt 1,
ii'i' There is a tendency for toner to disappear in areas other than the latent image, resulting in so-called fogging. This results in the formation of a toner image with low resolution, and the i@ image formed on the paper 9 also has a low resolution rQ ICf, b, and there is a fear that the print quality will deteriorate.

Also, 'T! In order to increase the resolution of A image Z7 image upper 7 development, the bias voltage of the developer F4I device 7, the charging condition of the toner, and the gap between the developer device 7 and the OPC belt 1 must be controlled very strictly. However, there were problems such as the equipment becoming damaged and maintenance becoming troublesome.

Also, around the OPC belt 1, there is a charger 5, an optical X-containing unit 6, and a current 1! ! It is necessary to arrange many components such as the container 7, the transfer member 8, the static eliminator 11, and the cleaner 12, resulting in the inconvenience that the entire device becomes complicated and large.

The water valve was developed in consideration of these points, and it is possible to form a high-quality image and a high-quality seal, and it is also suitable for It is an object of the present invention to provide an image forming method and apparatus that has a simple and compact configuration and that provides a low cost I-b storage.

[Failure to solve the problem]

The image forming method, which is the first invention of the present invention, first charges the entire surface of the photoreceptor's recording area during one rotation of the flame-shaped photoreceptor, and then charges the photoreceptor, Next, the charged portion is reversely charged by Coulomb force, which reduces the Coulomb force between the toner at the position of the transferred image corresponding to the image to be formed and the photoreceptor. , the dove with the reduced ink is transferred to a recording carrier to form an image, and then it adheres to the photoreceptor during the next revolution of the photoreceptor. The method is characterized in that the toner is charged so as to reverse the Ti potential of the 1-toner, and then the toner whose charged potential has been reversed is removed from the photoreceptor, and after that, the photoreceptor is discharged.

The image forming apparatus, which is the second invention of the present invention, includes a photoreceptor in the shape of a sharp edge, and when the photoreceptor is charged to one potential.
A charger that charges the residual toner with a negative potential on the photoconductor to a positive potential, and shields the photoconductor charged with a positive potential from 1 to 1 of the electric charge. a developing device for removing the residual t) charged to a positive potential from the photoreceptor, and a position of the image on the photoreceptor corresponding to the image to be formed on the plate 77 being neutralized by exposing the photoreceptor to light; A special feature characterized in that it has an exposure device that eliminates residual potential on the photoconductor, and a transfer device that transfers an edge located at the position of the transferred image on the photoconductor to the recording ID body. Effect] By operating the both r9 forming device γ, which is the second invention of the present invention, according to the both 1 < Q forming method, which is the first invention, high quality printing etc. can be achieved with high Ma + sad Otsu. will be applied.

1J, the following steps are performed during one rotation of the endless photoreceptor. First, the rotation of the photoreceptor '7 rQ
The entire formation area is charged to a positive potential by a charger, and while the charged portion of the photoreceptor passes through the developing plate, the dove that is charged to a negative potential is charged to the charged portion of the photoreceptor. Therefore, adhesion is avoided by an anchor on the surface. Next, the position of the transferred image corresponding to the image to be formed on the photoreceptor is exposed using the exposure device H3, and the charge on the photoreceptor at the same position is removed. The 112@ copying device transfers the dove at the position of the transferred image whose Coulomb force has been reduced to the record carrier, thereby forming an image with high M resolution on the record 11.

During the next rotation of the photoreceptor, each of the following rotations occurs.
The process will take place. In other words, the residual toner with a negative potential adhering to the photoconductor at the transfer stage is charged to a positive potential by a charging unit, and then charged to a positive potential by a current Q device. The residual toner is removed from the photoreceptor and collected. (The residual potential on the photoreceptor 1- is eliminated by exposing the photoreceptor to light using an exposure device.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3.

FIGS. 1 and 2 show an embodiment of an image forming apparatus according to a second aspect of the present invention.

FIG. 1 shows the rest of this embodiment, in which an ME-shaped OPC belt 21 is used as the photoreceptor. This OPC
The belt 21 is supported from the wafer side by a small []-ra 22, 22, a drive roller 23, and an exposure Z24 to be described later, and is moved by the drive roller 23 in the direction of the arrow in the figure. Other components are arranged around this OPC belt 21. In other words, OPC belt 21
On the upstream side of the exposure device 24 with respect to the traveling direction of the OPC belt 21, there is an o
A charger 25 is provided which corona-charges the residual toner with a negative potential adhering to the surface of the PC bell 1-21 to a positive potential during the next rotation of the PC bell 1-21. A current f& device 2G is provided between the charger 25 and the exposure device 24.

During the first rotation of the oPC belt 21, the present S unit 26 applies toner T of a negative potential to the surface portion of the oPC bells I to 21 which are charged to a positive potential. OPC belt 2 is attached to
During the next rotation, the charger 25 is charged to a positive potential, and the residual toner adhering to the oPC belt 21 is removed by a magnetic brush to which a negative bias is applied to the developer 26. ○Clean the surface of PC bell 1-21. Then, the exposure device 24 is connected to the OPC belt 2.
During the first rotation of 1, by exposing the OPC belt 21 to light, the developing device 26 forms 1.S-T, which is uniformly spread over the surface of the OPC belt 21. Scatter 7 corresponding to the image to be; 'is in the position of the elephant!・Reducing the adhesion force of the inner T to the OPC belt 21, the OPC belt 2 is removed during the next rotation of the OPC belt 21.
The residual charge fb on the surface of 1 is removed. This OPC belt 2
GJ 1 is provided in close contact with the back surface of the OPC belt 21 as shown in FIG. The exposure unit 24 of this embodiment has an LED 28 that emits light in response to a print command.
I) The light emitting part 29 is transparent (☆ (composed of fiber plays 1 and 31 connected through the resin 30, and the fiber plays 1 and 31 are LEI) 28 is OPC
Directly to the 1.1 side of the belt 21 1g 3? ′! Bikkoufu J
Iba l! T32 and housing glasses 33 and 33 that protect the optical fiber nT32 from both sides, and the surfaces of the optical fiber group 32 and the protective glass 33 are protected from friction with the back surface of the oPC belt 21. ! 2.It is a curved surface with a mirror finish to reduce resistance. On the other hand, the Ol) C belt 21 has 15 transparent base films 34 as shown in FIG. A wear layer 35 is formed on the surface side of the base film 34 to prevent charges from escaping to the ground side, and a transparent Ti electrode 36 and a negative fU key 11 are formed on the portion exposed by the light from the exposure device 24. The carry V generation layer 37 that generates the rear C and the T
i'l FM is applied to J3, and this carrier generation layer 3
When the surface side of 7 is charged with a positive potential by J: in the charger 25, the -1-Yarya C generated in the Kitriya generation layer 37 is moved toward the surface part. Uru kit
・V38 before transportation is FulliFj. Also, Honji f! ! In example 113, the transfer device 39 is placed opposite the exposure section 271 from the front side of the OPC belt 21, and
A predetermined distance from the surface of the C belt 21 is several tons. The paper 40 is prevented from passing between the transfer device 39 and the PC belt 21. And this transfer device 39
1- is located at the position of the transferred image where the fj adhesion force to the OPC belt 21 is reduced by the exposure n of the exposure device 24.
Only the Boo T is electrostatically attracted and transferred to the paper 40, forming a toner image on the U1 paper 40. Further, in the reverse direction of the paper 40, a fixing device 41 is provided for fixing the toner image formed on the paper 40.

Next, the operation of the image forming nail shown in FIGS. 1 to 2 will be explained in accordance with the first aspect of the present invention.

When a print command is issued, the first drive 1]-ra 23 is activated.
It rotates in the direction of the arrow in the figure and moves the oPC belt 21 in the direction of the arrow in the figure.

Therefore, the following operation is performed during the first rotation of the OPC belt 21.

First f1 charging: OPC due to the corona charging action of S25
The entire area of the transferred image forming area on the surface of the belt 21 is charged to a positive potential, and then this charged portion is transferred to the next developing device 26.
ml passing through the section is charged to a negative potential.
is applied uniformly.

To further explain the adhesion state of the toner T with reference to FIG. 2, the surface portion of the main 11 rear transport layer 38, which is the surface layer of the OPC bell 21, is charged to a positive potential by the corona charging action of the charger 25. , between this surface 1llJ1min and the negative potential toner T, the toner T is attracted to the carrier transporting FJ38 side, and the toner T is attracted to the carrier transporting layer 3.
The toner T° deposited uniformly on the surface of 8. The toner T° deposited on the surface of this 4-yaya transportation 1i! Ru.

Next, when the toner T portion spread on the surface by the advancement of the OPC bell 1-21 reaches the exposure device 24, the exposure device 24 selectively emits light toward the OPC belt 21. That is, the light generated by the LED 28 of the exposure device 24 is transmitted through the transparent resin 30 and the optical fiber FJ 32.
The light enters the inside from the wear-resistant layer 35 of the OPC belt 21 through the lens, passes through the base film 34 and the electrode 36 in order as shown by the arrow a in FIG. 1 of the position forming the . Yariya generation layer 37
to expose. In this 1゛1νsu1a generation layer 37,
A negative potential 4-tyr C is generated from the part exposed to light, and in the next 4-nary transport F138, the negative potential 4-tyr A=C and the positive potential charge on the surface are mutually generated. They attract each other and move in opposite directions, 1FjJ L/, and are electrically neutralized. When the positive potential charge on the surface of this J, 138, which was used to transport carriers, is eliminated, the area becomes
This means that the Coulomb force that causes the dove-T to attach is lost, and the dove-T in this area becomes a transferred image that can be transferred. - horn, still -1 in unexposed parts
Toner T is returned to F1 by -L1 linker.
41 pieces are placed on 30 surfaces. By exposing the toner 24 times in this manner, a formed plate 't7 image consisting of note T'-T is formed in the toner T portion of the surface of the OPC belt 21 by reducing the fJ valley force applied to the OPC belt 21. Ru. Furthermore, this transferred image has extremely high resolution.

And Kimi IJI! In the example, since the transfer device 39 is provided opposite to the exposure device 24, a transferable image is formed on the surface of the rear transport layer 38 at the same time as described above. , φλ copying: By the bias voltage of positive potential in S39, the negative potential hner T of the transferred image portion attached to the surface of the carrier transport layer 38 is attracted toward the transfer device 39, and the paper on the way is ηt4 is copied onto the surface of 40 to form a toner image. The image formed on this paper 40 is a scattered image 77 formed at high resolution on the surface of the carrier transport layer 38 of the OPC belt 21, and is thus transferred as is. , the G degree of the solution is also extremely high.

Thereafter, the paper 40 is peeled off from the OPC bell 1-21 and sent to a fixing device 41, where the fixing device 41 fixes the [] and [ner] images, and then transfers it onto a paper tray (not shown) of 1M.
It is papered.

-OPC belt 21 that passed through 1st turn 75' Kaoru 39 part
As it makes its next revolution, the next 11 "O" movements are made.

The toner T in the area other than the image on the plate ``rj'' that was not transferred by the transfer TJ' unit 39 remains on the surface of the OPC belt 21 as a residual gutter and is allowed to float. It is reversely charged from a negative potential to a positive potential by the Korop charging n of the charging device 25. The residual toner on the OPC belt 21, which has been charged to a positive potential in this way, is attracted to a magnetic brush to which a negative bias is applied in the next developing unit 26 and is collected into the developing roller 26. As a result, the remaining (iy1 toner) is completely removed from the surface of the 0r)C belt 21.
The entire surface of the PC belt 21 is exposed to light while passing through the exposure unit 24, residual potential is partially removed in the same way as in the case of forming a transferred image, and the PC belt 21 is moved forward in order to be used for the next new printing. It will be done.

In this way, in this embodiment, it is possible to form an image with an extremely high degree of yI?IfII on the yK((40).

Furthermore, since the electrophotographic process is performed while the oPC belt 21 rotates twice, the conventional static eliminator 11 and cleaner 12 can be omitted, resulting in a more compact configuration and a more compact system. becomes possible.

Furthermore, since this is performed for the rest of the fJ μ-wave transfer loop formation range of the toner on the surface of the OPC belt 21 in the developing device 26, each child that needs to be closed in development: S26. The viscosity is greatly reduced compared to that of the conventional example.

Note that in this embodiment, the exposure device 24 and the transfer device 39 are
The transfer device 39 is arranged so as to be separated from the exposure device 24 toward the downstream side in the traveling direction of the OPC belt 21, so that the formation and transfer of the transferred image are performed almost simultaneously. It is also possible to provide a temporal gap between the formation of the image and the transfer.

FIG. 3 shows another embodiment of the exposure device 24. The exposure device 24 of the present embodiment has a liquid crystal shutter array head and an L
44 (referred to as a CS head) is used to optically write onto the OPC belt 21. That is, light emitted from a light source 45 made of a normal lamp or the like enters the inside of the LCS head 44 through a light guide 46. After that, the incident light passes through the protective glass 47, and then the LC
To control the energization to the transparent conductors (49, +49) on both sides of the S hill 48, the light passes through a liquid crystal segment that is selectively made into a light-guiding state, and then passes through a transparent retainer made of a contact agent. ,
The light passes sequentially through the sR 50 and the optical fiber fermenters 52 of the fiber plays 1 and 51, enters the oPC belt 21, and is used to form a transferred image in response to a printing command. At the fiber plate 51, the optical fiber l'! T52 is held in a housing 4 by protective glasses 53゜53 from both sides, and the optical
The C-belt 21 contacts with an Eftft finished Iζ curved surface.

The exposure devices 24 shown in FIGS. 2 and 3 each contact the 94 parts of the OPC belt 21 and emit light! ) The surface of the d1-containing side of the exposure device 24 is exposed to the back surface of the OPC belt 21. In addition, although both examples use transparent electrodes 36.49,
These may be replaced by translucent electrodes made of an aluminum bucket thin film or the like having a thickness of 0.1 .mu.7 nm or less through which the exposure light passes in -1 minute.

In addition, the exposure device 24 can be used as an oPC bell!・Kitorya transport layer 38 is provided on the surface side of 21 to pass through the toner T.
The surface of the transfer material may be exposed to light to eliminate the charge, thereby forming a transferred image. In this case, the transfer device 39 is OP from the exposure device 24.
It will be provided on the downstream side in the traveling direction of the C belt 21. Furthermore, in this case, oPC bells 1 to 1 are used as toner carriers.
21, a normal photosensitive drum can be used.

Further, the present invention is not limited to the above embodiments, and can be modified as necessary.

〔Effect of the invention〕

Since the image forming method and apparatus of the present invention are constructed and operated in this way, images can be formed with high resolution, and l) quality printing can also be performed. However, the overall structure of the hat can be made simple and compact, and the cost can be reduced.

[Brief explanation of drawings]

1 and 2 show an embodiment of the image forming apparatus of the present invention, FIG. 1 is an overall configuration diagram, FIG. 2 is a front view showing exposure 8, and FIG. 3 is a diagram showing other parts of the exposure core. Embodiment: front view, 4th
The figure shows a conventional example and is a diagram of a body 43. 21... OPC belt, 24... Exposure source, 25...
- Charged thoughts, 26...now! & vessel, 28...LED. 32.52...Optical fiber group, 37...Carrier 1a generation, 38...Ki1r pulling/transport layer, 09...
・Transfer device, 40...Paper, 41...Constant '0:'J
% 44... LCS head, 45... Light source, 48
...LCS Hill. −” Applicant’s Representative Medium
R Shun ４jll Figure q Figure 3 $4wJ

Claims (1)

[Claims] 1) During one rotation of an endless photoreceptor, the entire surface of the photoreceptor where an image is to be formed is first charged, and then the oppositely charged toner is charged by Coulomb force. attached by;
Thereafter, the Coulomb force between the toner at the position of the transferred image corresponding to the image to be formed and the photoreceptor is reduced, and then the toner whose Coulomb force has been reduced is transferred to the recording carrier to form the image. After that, during the next rotation of the photoreceptor, the toner is charged so as to reverse the charging potential of the toner adhering to the photoreceptor, and then the toner with the charged potential reversed is transferred to the photoreceptor. An image forming method characterized by removing static electricity from a photoreceptor, and then eliminating static electricity from a photoreceptor. 2) An endless photoconductor, a charger that charges the photoconductor to a positive potential and also charges the residual toner with a negative potential attached to the photoconductor to a positive potential, and a photoconductor charged to a positive potential. a developing device that attaches toner with a negative potential to the photoreceptor and removes the residual toner charged with a positive potential from the photoreceptor; and a developer that exposes the photoreceptor to light to form an image on the photoreceptor. An image forming apparatus comprising: an exposure device that eliminates static electricity at the position of a transferred image and residual potential on a photoreceptor; and a transfer device that transfers toner at the position of the transferred image on the photoreceptor to a recording carrier.