JP2636836B2 - Image recording method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary of the Invention] In the present image recording method, an image is exposed from the back surface of a photoconductor on which a transparent substrate, a transparent conductive layer and a photoconductive layer are laminated, and an insulating toner is developed at the same time. The toner is removed and then transferred to a recording sheet to obtain a toner image. This prevents so-called fogging and provides a good image density.

[Technical Field of the Invention]

The present invention relates to an image recording method, and more particularly, to an image recording method in which an image is exposed from the rear side of a transparent base photoconductor, an insulating toner is developed, and then a non-exposed portion toner is removed and transferred to a recording paper.

[Conventional technology and problems]

Conventionally, as a method for forming a toner image simultaneously with image exposure, there is an image forming method as proposed in Japanese Patent Application Laid-Open No. 57-119375. An image forming apparatus using this method is shown in FIG. 5A.

As shown in FIG. 5A, a transparent conductive layer 1b was provided on a transparent substrate 1a, and a sufficiently thick photoconductive layer 1c and a surface layer 1d were further laminated on the photoreceptor 1 and charged with a conductive magnetic toner 3. The magnetic brush developing machine 2 is arranged to face. A power supply 4 applies a developing bias between the developing device 2 and the conductive layer 1b. In the transparent state, the image exposure means 5 arranged on the back surface of the photoreceptor 1
Is used to perform image exposure. Then, as shown in FIG. 5A, photocarriers are generated in the photoconductive layer 1c and move to the toner side. As a result, the toner adheres to the photoreceptor 1 by electrostatic attraction with the opposite charge induced in the toner.

On the other hand, in the non-exposed area, the photoconductive layer 1c is thick, so that the electrostatic attraction is weak and the toner adhering to the photoconductor 1 is small. As a result, a toner image 6 corresponding to the image exposure is formed on the photoconductor 1.

In the above method, an image is formed by utilizing a difference in electrostatic attraction acting on toner in an exposed portion and a non-exposed portion. Therefore, in order to reduce fogging, the photoconductive layer 1c needs to be considerably thick. However, it is difficult to manufacture a photoconductor having a large thickness with a uniform thickness, and it is necessary to increase the recording voltage as the thickness increases.

Further, in addition to the fogging problem described above, if this method is applied to an image recording apparatus that performs image transfer by electrostatic transfer to recording paper,
There is a problem that plain paper cannot be provided as recording paper. This is because when using plain paper (10 ¹¹ to 10 ¹² Ω · cm) with a small surface resistance in the electrostatic transfer process to use conductive magnetic toner, the charge of the toner leaks through the recording paper, Transfer efficiency drops to around 50%.
Therefore, it is necessary to use expensive special paper having a high resistance treatment on the surface of the recording paper as the recording paper.

Therefore, in the present invention, in the image recording process using the transparent base photoreceptor, the photoconductive layer constituting the photoreceptor is about 10 μm
It is an object of the present invention to provide an image recording method capable of obtaining a good image with little fogging even if the recording paper is thin and in which inexpensive plain paper can be used as recording paper.

[Means for solving the problem]

According to the present invention, there is provided a photosensitive member comprising a transparent conductive layer and a photoconductive layer sequentially laminated on a transparent substrate, an image exposing means on the transparent substrate side, and an insulating toner on the photoconductive layer side. A first developing machine filled with is exposed to an image, and a voltage is applied between the first developing machine and the transparent conductive layer, and image exposure is performed using the image exposing means, and a latent image is formed near the surface of the photoconductive layer. Forming an image charge image, performing insulating toner development, and then using a second developing device to remove toner adhered to the non-exposed area and transferring the toner image on the photoconductor to recording paper Further, after the transfer, in order to eliminate the charge of the residual toner and the latent image charge on the photoreceptor, the corona discharge from the photoconductive layer side and the light discharge from the transparent substrate side are carried out by the photosensitive exposure. The image recording method is characterized by including a static elimination step performed simultaneously on the same part of the body. It is solved.

1A, 1B and 1C show the principle of image recording. In particular, FIG. 1A shows an exposure and development step, FIG. 1B shows a contrast development step, and FIG. 1C shows an electrostatic transfer step.

In the image exposure step of FIG. 1A, the insulating toner development is performed simultaneously with the image exposure. First, a transparent substrate 11a such as glass, acrylic, or polyethylene terephthalate, a transparent conductive layer 11b such as an indium oxide vapor-deposited film, and a transparent conductive layer 11c such as a Se-based / cds-based / a-Si / organic photoconductor. A base photoconductor 11 is provided. An insulating toner 13 is placed on the photoconductor 11.
A first magnetic brush developing machine 12 filled with
A power source 14 applies a developing bias between the transparent conductive film 11b and the transparent conductive film 11b. In this state, image exposure is performed using image exposure means 15 such as a laser optical system and an LED optical system.

Then, photocarriers are generated in the photoconductive layer 11c, move to the surface of the photoconductive layer 11c, and become latent image charges 16 (negative charges in the figure). At the same time, the positively charged insulating toner 13 adheres to the exposed portion to form a toner image 17. On the other hand, even in the non-exposed area, the electric field acts between the developing device 12 and the transparent conductive film 11b, so that the toner 18 adheres.

In FIG. 1B, in a contrast developing step, a magnetic brush developing machine 19 filled with the same toner 20 as the first developing machine is connected to a transparent conductive film.
By setting the same potential as 11b, the toner 18 attached to the non-exposed portion is collected by electrostatic attraction and magnetic force. At this time,
Although the image portion toner 17 is also slightly recovered, most of the toner remains on the photoconductor 11 and the toner image 17 is formed because the latent image charge 16 and the attached toner 17 have strong electrostatic attraction.

In the electrostatic transfer step shown in FIG. 1C, the toner image 17 is transferred to the recording paper 21. As a transfer method, electrostatic transfer such as roller transfer and corona transfer is generally used. Here, the roller transfer will be described. The recording paper 21 is superimposed on the toner image 11 on the photoconductor 1,
A conductive rubber roller 22 for transfer is provided thereon, and a constant pressure is applied. Further, a transfer voltage is applied by the power supply 23 to
The toner image 17 on 11 is electrostatically transferred to the recording paper 21. In the method of the present invention, since an insulating toner is used, even if plain paper having low resistance is used as recording paper, no electric charge leaks. Therefore, transfer of the toner image to plain paper is possible.

After the electrostatic transfer, the toner image 24 on the recording paper 21 is fixed to the recording paper 21 by a method such as heat fixing, pressure, fixing, or flash fixing, and becomes a semi-permanent recording image.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a schematic diagram for explaining one embodiment of the present invention when an insulating magnetic toner is used as the insulating toner.

In FIG. 2, reference numeral 31 denotes a transparent base photoreceptor, 100 μm
It is composed of a transparent substrate 31a of polyethylene terephthalate, a transparent conductive layer 31b of an indium oxide deposited film, and an organic photoconductive layer 31c having a thickness of 10 μm. Then, the photoconductor 31 rotates in an endless belt shape in the direction of the arrow in the figure, and the transparent conductive layer 31b is connected to the ground.

Reference numeral 32 denotes a first magnetic brush developing machine, the structure of which is shown in FIG. The developing device 32 includes a magnet roller 32a having a plurality of magnetic poles, a sleeve 32b for holding the toner, and a blade 32c for adjusting the height of the toner. This developing machine 32
Is filled with the insulating magnetic toner 32d, and the toner is conveyed by rotating the magnet roller 32a. The toner 32d is frictionally charged with the sleeve 32b and the blade 32c during transportation. In the case of this embodiment, a positive charging toner is used. Further, a developing bias (+200 to +300 V) is applied to the developing machine 32 by a power supply 33.

Reference numeral 34 denotes an image exposure device, which comprises an LED array optical system. 35
Is a toner image attached to the exposed portion, 36 is a latent image charge, and 37 is a toner attached to the non-exposed portion.

Numeral 38 denotes a second magnetic brush developing machine for removing the non-exposed portion toner 37, which has the same configuration as the first developing machine 32, is filled with the same toner, and the sleeve is connected to the ground. Reference numeral 39 denotes a toner image after removing the non-exposed portion toner 37.

40 is a recording paper, which uses inexpensive plain paper. Reference numeral 41 denotes a transfer conductive rubber roller which is pressed against the photoreceptor 31 at a constant pressure. 42 is a transfer voltage of the transfer roller 41 (−200 to
-600V). Reference numeral 43 denotes a toner image electrostatically transferred onto the recording paper 40, which is fixed by a pressure fixing device 44. Reference numeral 45 denotes a semi-permanent image record obtained on the recording paper 40. Reference numeral 46 denotes a residual toner image remaining on the photoconductor 31 after transfer. 47 is the latent image charge
This is a static elimination light source that releases 36. Reference numeral 48 denotes an AC corona discharger for removing charges from the toner 46, and reference numeral 49 denotes a power supply thereof. Numeral 50 denotes a toner image that has lost electrostatic attraction due to static elimination.

 Next, an image recording procedure will be described.

First, the photoconductor 31 is rotated in the direction of the arrow. In the exposure and development process, the image is exposed according to the image pattern using the image exposure device 34 in a state in which the toner is carried by rotating the magnet roller 32a of the first developing device 32 and the developing bias is applied to the sleeve 32b. . Then, in the exposed portion, negative charges are injected into the photoconductive layer 31c from the transparent conductive film 31b. At the same time, the toner charged to the opposite polarity to the injected charge adheres to the photoconductor 31, and a toner image 35 is formed. Then, at the end of the exposure, the injected charges cannot move, and become latent image charges 36 near the surface of the photoconductive layer 31c. On the other hand, the electric field acts between the developing device 32 and the transparent conductive layer 31b even in the non-exposed portion, so that the toner 37 adheres.

Next, in the contrast development step, the toner is conveyed by the second developing device 38 connected to the ground, and the non-exposed portion toner 37 is collected by electrostatic attraction and magnetic force. At this time, the image portion toner 35 is also slightly recovered, but the electrostatic attraction with the trapped charge 36 is strong.
A remaining toner image 39 is formed on 31.

Thereafter, the toner image 39 is electrostatically transferred to the recording paper 40 using the transfer roller 41, and the toner image 43 copied by the fixing device 44.
Is fixed on the recording paper 40. As a result, a semi-permanent recorded image 45 is obtained.

On the other hand, after the transfer, the residual toner 46 remaining on the photoconductor 31 is
The electric charge of the toner 46 and the trapped electric charge of the electric charge are eliminated by the neutralizing light source 47 and the corona discharger 48, so that the toner 46 is collected by the developing device 32 which does not lose the electrostatic attraction. The next image formation is performed simultaneously with toner collection. Performing the recovery of the residual toner 50 and the exposure and development at the same time does not cause any problem since the image exposure device 34 is on the back surface of the photoconductor 31.

In the present embodiment, the use of the insulating magnetic toner enables the electrostatic transfer to inexpensive plain paper. further,
Despite the use of a thin and inexpensive organic photoconductor for the photoconductive layer, image recording with little fog on plain paper and sufficient contrast was obtained.

The present invention is described in the claims "after the transfer,
In order to eliminate residual toner and latent image charges on the photoreceptor, a charge removal step of simultaneously performing a corona discharge from the photoconductive layer side and a light discharge from the transparent substrate side to the same portion of the photoreceptor. In addition to the effect of (A) that the residual toner after the transfer can be easily collected in the first developing device and the occurrence of an afterimage is prevented, (B) the image recording apparatus can be downsized. In addition to the effect described above, (C) the effect of preventing early deterioration of the photoreceptor can be prevented as described below.

With reference to FIGS. 4 (1) to (4), the charge removal step after transfer will be described in comparison with various charge removal modes other than the present invention.

[1] First, as shown in FIG. 4A, the residual toner is held on the photoreceptor after transfer by electrostatically attracting the latent image charge.

[2] Even if only light removal is performed in this state, the latent image charge cannot be erased because it is electrostatically attracted to the charge of the residual toner.

[3] On the other hand, when only corona discharge is performed from the photoconductive layer side (the upper side in the figure) as shown in FIG. 4 (2),
The charge of the residual toner can be erased. Then, the toner with no charge can be collected in the developing step of the next recording cycle. However, the latent image charge cannot be substantially erased for the following reasons. That is, when the charge of the residual toner is erased as described above, a charge of the opposite polarity corresponding to the latent image charge left behind is induced in the transparent conductive layer, and the latent image charge attracts the charge of the opposite polarity. . However, due to the high dark resistance of the photoconductive layer,
The speed at which the latent image charge moves in the photoconductive layer toward the transparent conductive layer is low, and cannot move far from the surface (the upper surface in the figure) of the photoconductive layer by the next recording cycle. Therefore, in the next recording cycle, the toner adheres again and an afterimage is formed.

[4] As shown in FIG. 4 (3), when corona discharging and photo discharging are simultaneously performed from the photoconductive layer side (upper side in the drawing), the latent image charges as well as the residual toner charges can be erased. This is because the photoconductive layer is made conductive, so that the latent image charge can immediately move to the opposite polarity charge in the transparent conductive layer. However, in this case, since the toner has an effect of blocking light, it is necessary to remove static electricity with strong light, and there is a problem that the photoconductor deteriorates early.

[5] In addition, as shown in FIG. 4 (2), when the corona discharge is performed from the photoconductive layer side and then the light is removed from the transparent substrate side (not at the same time), the photoconductive layer surface and the transparent conductive Since no external electric field is applied between the layers, the speed at which the latent image charges move in the photoconductive layer toward the transparent conductive layer is low,
It cannot move too far from the surface of the photoconductive layer by the next recording cycle. Therefore, in the next recording cycle, the toner adheres again and an afterimage is formed.

[6] In the present invention, as shown in FIG. 4 (4), the corona is removed from the photoconductive layer side with the photoconductor interposed therebetween.
From the transparent substrate side, photo-static elimination is performed simultaneously. By performing the light removal from the transparent substrate side, the shielding effect due to the residual toner is not received, so that the photoconductive layer can be made conductive without intense light. In addition, by performing corona discharge from the photoconductive layer side, an electric field is applied between the corona wire and the transparent conductive layer due to the high voltage applied to the corona wire, and an external electric field is formed. In other words, the photoconductive layer is made conductive and an external electric field is formed by performing the photostatic discharging from the transparent substrate simultaneously with the corona discharging from the photoconductive layer side, so that the latent image charges can be immediately erased and the next recording cycle can be performed. No residual image is formed, and no early deterioration of the photoconductor occurs as in the case where both the corona charge removal and the light charge removal are performed from the photoconductive layer side as shown in FIG. 4 (3).

The above-mentioned effect is obtained for the first time by the configuration of the present invention in which corona discharge from the photoconductive layer side and light discharge from the transparent substrate side are simultaneously performed on the same location.

〔The invention's effect〕

According to the present invention, since an image is formed by an exposure development step, a contrast development step, and a transfer step, even if a photoconductive layer having a small thickness is used, sufficient image density can be obtained with almost no fog. Furthermore, by using an insulating toner, it is possible to perform electrostatic transfer to plain paper at low running cost.

[Brief description of the drawings]

FIGS. 1A, 1B, and 1C are schematic views for explaining the principle of image recording according to the present invention, and FIG. 2 shows one embodiment of the present invention when an insulating magnetic toner is used as the insulating toner. FIG. 3 is a schematic diagram for explaining the embodiment, and FIG.
FIG. 4 is a schematic view of the first magnetic brush developing machine shown in FIG. 4, and FIGS. 4 (1) to (4) compare and explain various static elimination modes other than the present invention and the static elimination mode of the present invention. 5A and 5B are schematic diagrams for explaining a conventional technique. 1,11,31 ... Photoconductor, 1a, 11a, 31a ... Transparent substrate, 1b, 11b, 31b ... Transparent conductive layer, 1c, 11c, 31c ... Photoconductive layer, 1d ... Surface layer, 2 ... ... Magnetic brush developing machine, 3 ... Magnetic toner, 4,14,23,33,42 ... Power supply, 5,15,34 ... Image exposure means (apparatus), 6,17,35 ... Toner image, 12 , 32... First magnetic brush developing machine, 13,20... Insulating toner, 16, 36... Latent image charge, 18, 37. 40 ... Recording paper, 32b ... Sleeve, 32c ... Blade, 32d ... Insulating magnetic toner, 38 ... Second magnetic brush developing machine 22,41 ... Transfer roller, 45 ... Image recording, 46 ... residual toner image, 47 ... static elimination light source, 48 ... AC corona discharger.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Junzo Nakajima 1015 Kamikodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (56) References JP-A-55-32051 (JP, A) JP-A-58-98747 (JP, A) JP-A-60-22146 (JP, A) JP-A-60-55376 (JP, A) JP-A-60-55375 (JP, A) JP-A-60-136785 (JP, A) JP-A-60-149051 (JP, A) JP-A-56-64359 (JP, A) JP-A-57-23964 (JP, A) JP-A-58-83862 (JP, A) JP-A-58-102255 (JP, A) JP, A) JP-A-60-43679 (JP, A) JP-A-59-123873 (JP, U) JP-A-55-103650 (JP, U)

Claims (1)

(57) [Claims] An image exposure means is provided on a transparent substrate side of a photoreceptor comprising a transparent conductive layer and a photoconductive layer sequentially laminated on a transparent substrate.
On the other hand, a first developing device in which an insulating toner is filled on the photoconductive layer side is disposed opposite to the first developing device, and an image is exposed using the image exposing means in a state where a voltage is applied between the first developing device and the transparent conductive layer. Forming a latent image charge image in the vicinity of the surface of the photoconductive layer and performing insulating toner development, and then removing the adhered toner in the non-exposed area using a second developing device; Transferring the toner image to recording paper, and after the transfer,
In order to eliminate residual toner charge and latent image charge on the photoreceptor, corona discharge from the photoconductive layer side and light discharge from the transparent substrate side are simultaneously performed on the same portion of the photoreceptor. An image recording method comprising a charge eliminating step.