JPS5974566A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic receptor forming an image of high contrast and high density, and having superior humidity resistance and high durability, etc., by forming an Ni conductive layer on a substrate, and forming an Se type photoconductive layer and a transparent insulating layer in succession. CONSTITUTION:A conductive layer 2 is formed on a conductive substrate of aluminum or the like or an insulating substrate 1, such as polyester. On the layer 2, a photoconductive layer 3 contg. Se alone, or Se as a main component, and Te or the like, and on the layer 3 a tansparent insulating layer 4 made of polyester resin or the like. It is preferable that a laminate photoconductive layer 3' consisting of an Se type charge transfer layer 3a of Se doped with <=4,000 ppm halogen, and a charge generating layer 3b contg. 5-25% Te is used in place of the single layer 3. It is advantageous to keep the temp. of the substrate 1 at 55-65 deg.C at the time of forming the layers 3, 3', and to heat treat said substrate at 30-65 deg.C after forming the insulating layer. As a result, a photoreceptor forming a high-contrast and high-density image and having good durability is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photoreceptor that silently copies a latent image onto a dielectric film as a charge pattern.

Generally, electrophotographic photoreceptors have a conductive layer and a photoconductive d layer.

It is composed of an insulating layer, and during the latent image forming process, the primary phase current and the secondary band 'd (AC band formation or continuous band 'd) are simultaneously formed, as proposed in Japanese Patent Publication No. 42-23910 or No. 43-24748. An electrophotographic photoreceptor, in which an electrostatic latent image is formed by a process including exposure to a charged light image, is usually produced by forming a thin film on a conductive support on the side of the conductive material by vacuum deposition.

Conventionally, the conductive layer constituting the electrophotographic photoreceptor was made of aluminum (A/?), and the light guide iff and III# were made of selenium (Se).
There is one in which the insulating layer is made of PE'I'. This body has P-type characteristics, and in the latent image formation process, a negative primary corona zone '1. When applying positive secondary corona charging and photoimage exposure and full-scale exposure at the same time.

-The dark resistance of the selenium photoconductive layer increases due to the water charge.

In addition, carrier injection from the fourth layer side is reduced.

I couldn't. As a result, the photoconductivity [the effective photosensitivity 1 (-) of the main insulating layer is lost; Because it depends only on the process of
In the case of C, the contrast is almost 1", and in the case of the opposite polarity DC corona zone 'α, only a very low contrast is obtained.

Next, as an auxiliary means, it was devised to carry out full-surface exposure for the next phase, and then perform full-surface exposure after the second phase charge, and then carry out photoimage exposure at the same time as the secondary charge.

This made the contrast a little more enlightening.

On the other hand, to obtain enough contrast for practical use,
In addition to the above-mentioned Naruko photographic photoreceptor, a lead oxide film is known, which is formed by dispersing powder of the phosphor ZnCd5 and powder of the light guiding screw material ZnO in an @ fat binder, but it has problems in terms of moisture resistance. l:'+C3゜This invention was made to solve the above problems, and by providing a nickel conductive layer on one side of the selenium-based light guide 4H and providing an insulating layer on the other side, The object of the present invention is to provide an m-child photographic photoreceptor capable of obtaining images with high contrast and high density.

The present invention will be described in detail below with reference to the drawings.

Figure 1 shows the basic structure of this invention, where 1 is a conductive material such as nickel (Ni), '1' aluminum (A/'), copper (Cu), stainless steel (Sue), or PgT. The support layer is made of an insulating material such as. This support rests on the formation of length. At this time, the support 1 and the conductive layer 2 may be integrally formed of nickel. Thereafter, selenium (Se) or a selenium-based photoconductor 1-3 containing selenium as a main component is formed on the upper surface of the nickel conductive wt layer 2.

Furthermore, polyester (P13T) with high volume resistivity (more than lQl+Ω) that transmits visible light to RF5,
A transparent insulating layer 4 made of xylene and other resins such as acrylic, epoxy, urethane, fluorine, styrene, and carbonate is pasted. This transparent insulating layer 4 is 5~
It is formed to a thickness of 40μ.

The basic structure of this invention has been shown above, but preferably the first
As shown in FIG. 2, the photoconductive layer 3 is composed of selenium or a selenium-based selenium-based selenium doped with halogen (charge transport layer 3a and '1 charge generation f131 mainly composed of selenium and tellurium).
) is preferable. That is, in order to obtain high contrast, the charges injected from the conductive α layer 2 during temporary charging must move through the photoconductive layer 3' without being blocked. Moreover, it is known that when a selenium-based photoreceptor is doped with even a small amount of impurities other than halogen, the mobility decreases. however.

Simultaneous optical image of the secondary band It # At the time of full-scale exposure at the customer site and in the final process, the light sensitivity range of a pure selenium single layer is limited to the short wavelength range of visible light, resulting in poor efficiency.
It is necessary to expand the spectral sensitivity range and improve efficiency by doping with , As, or the like.

In order to satisfy the above two conditions at the same time, a charge generation layer 36 is formed under the transparent insulating layer to be thin enough not to reduce the mobility, as shown in Figure 1 and C2. Measures the expansion of light, increases light sensitivity, and simultaneously charges light 1#! This charge generation layer 3b (!: charge transport in which selenium is doped with 0 to 4000 ppm of halogen between the conductive layer 2) Hibiki 3a improves the efficiency during exposure and full-surface exposure.
It is necessary to increase the mobility of the charge injected from the conductive layer 2 by providing the -water charge 1 and to improve the -order sensitizing charging effect.

Further, this photoconductive layer 3' will be explained in detail. The charge generation layer 3b described above has a tellurium content of 5 to 25 5e-
The Te layer is formed with a thickness of 0.05 to 5μ, and is optionally used for the purpose of preventing crystallization, improving sensitivity, and removing residual potential (moreover, it contains arsenic (As), silicon (Si), antimony (Sb), etc.).
) May be doped with halogen. In addition, the '1 nitrogen transport layer 3a is made by doping selenium of high purity IW of 5 n (99,999%) or more with 0 to 4000 PPm of halogen, and depositing this on the upper surface of the α-conducting layer 2 to a thickness of 20 to 70 μm. Vacuum evaporate so that

At this time, the substrate temperature for vacuum deposition is set at 55 to 65°C. This is because when the substrate temperature is 55° C. or less, the residual number 1 increases, the response deteriorates, and contrast cannot be obtained. Moreover, if the temperature is higher than 65°C, the resistance of the light guide layer will drop significantly, and when a voltage is applied, the light guide layer 3
Since the electric potential is no longer distributed between the areas 1 and 2, charges are injected and moved from the 4-ring 712 without distinguishing between bright and dark areas in the secondary simultaneous charging light image exposure, resulting in a loss of contrast.

Next, the conductive layer 2, which is another key to high contrast, will be explained. The requirements for the conductive layer 2 are: firstly, it exhibits good injection properties during primary charging, and secondly, there is no injection from the 1ζ conductor 71 I storage 2 in order to obtain contrast between bright and dark areas during secondary charging and simultaneous light exposure. It becomes necessary. That is, a conductive material that is aligned with the photoconductive layer 3' is required for the latent image formation process. The characteristics of the nickel conductive layer in this invention and the conventional conductive layer will be clarified through the following experiments.

A conventional selenium-based photoreceptor with an aluminum conductive layer and a photoreceptor of the present invention with a nickel conductive layer each had -200
Examining the potential drop when strong full-plane exposure is performed after 0V corona charging in the dark, we find that in the case of aluminum (conventional example) there is a change in IF level of approximately xooov, while in the case of nickel (proposed) is about 150v, which is significantly smaller than that of aluminum. In this case of nickel −
It can be seen that during the dark charging of ZOOOV, curves corresponding to -1850V are already formed above and below the insulating layer. On the other hand, in the case of aluminum, a potential distribution of approximately -1000Y occurs in the photoconductive layer, and a charge equivalent to 1000V, which is about half of the dark charge of -2000V, is formed above and below the insulating layer, and f, 31 products < T 't [@ (7) Yuika 3□.

. I understand 6 o yoka 3.

Next, when the conventional photoreceptor and the photoreceptor of the present invention are each positively corona charged to +2000V assuming secondary charging, the potential changes are about 1150Y for both.

As a result, the photoreceptor of this invention has good injection properties during primary chargingζ
It was also found that the α charge was inhibited by 15u during secondary charging, and it was found that high contrast exhibited characteristics such as f. The physical mechanism governing the injection property at the interface between the nickel conductive layer and the photoconductive layer is shown below.
There are two possibilities.

1) Surface condition of the nickel conductive layer (e.g. contact surface roughness) 2)
Recombination center density in the photoconductive layer at the interface.

3) Difficulty in forming a barrier layer due to the difference in work function between selenium and nickel.

4) Easier barrier layer formation due to the difference in work function between the support layer and nickel.

Next, to demonstrate the physical mechanism of this invention.

I conducted several types of experiments, so I will explain them step by step.

■) Example 1 A conductive layer was formed by vacuum evaporating nickel with a purity of 50 to a jl of about 0.5μ on a drum-shaped aluminum support. A charge transport layer is formed by vacuum depositing selenium having a purity of 5n at 60° C. to a thickness of about 50 μm. Next, 1 layer is placed on the charge transport layer.
Approximately 0.5μ of Be-1”e alloy containing 0% tellurium
A charge generation layer is formed by vacuum evaporation to a thickness of
The photoreceptor of this invention was constructed by pasting a 0μ P[H'I' film to form an insulating layer.

As this photoreceptor-water charging, Scorotron charger Q2
000V charging sequence, next cycle 6.5KV O) A C
A corona zone formation and simultaneous light image are exposed, and then the entire surface is exposed to form an electrostatic latent image.

Also, after doing the same Iζ and jumping in one water belt, 1 + 6.5KV
A light image is simultaneously exposed on the positive corona charge, and then the gold surface is exposed to light to obtain an electrostatic latent image.

The above experimental results are as shown in the table, AC460V1)
It showed a high contrast potential of C555V. When the electrostatic latent image of Example 1 was developed with a magnetic brush and transferred onto a sheet of paper using a roller, a good image with high density was obtained. Thereafter, when the charge was removed, the image was cleaned, and the next image was repeated, a good image was obtained with no residual potential or afterimage.

Furthermore, when the photoreceptor of Example 1 was left under high humidity at a relative humidity of 85% 1LH for 3 days and an electrostatic latent image was again formed in the same manner as described above, the contrast potential hardly changed.

X) Example 2 Nickel was vacuum deposited on a PET support of 50F to a thickness of about 1μ.
A conductive layer is formed thereon, and selenium containing soppm of chlorine is vacuum-deposited thereon to a thickness of 40 μm at a substrate temperature of 55° C. to form a charge transport layer. Furthermore, 1
A layer of 5% tellurium is vacuum deposited to form a charge-generating layer (4), and then varaxylin is vapor-deposited onto a 20 μm layer (9) to form an insulating layer. When this sample was tested under the same conditions as in Example 1, AC455Y
1) It showed a high contrast potential of C585V.

■) Reference example 1゜ Se-'L'e alloy containing 10 layers of tellurium was placed on a drum-shaped aluminum support at a substrate temperature of 60°C.
A photoconductive layer is formed by vacuum deposition on a 50 μm jX, and a 20 μm round film is laminated thereon to form a conventional type photoreceptor. This sample was subjected to 11 actual tests under the same conditions as in Example 1.

As shown in Table r, only a low contrast potential of AC70V and J)C170V could be obtained.

vL) Example 3 AI formed into a drum shape! A conductive layer was formed by electroplating silver to a thickness of about 0.5μ on the support, and Se containing 10% tellurium was deposited on this conductive layer at a substrate temperature of 60'C.
-'l''e alloy is vacuum deposited to a thickness of 50μ to form one layer of light-guiding 'fJL skin, and on this photoconductive layer 20μ
A PET film of .mu. is attached to form an insulating layer to produce the photoreceptor shown in FIG. 1 of the present invention.

When this sample was tested under the same conditions as Example 1, it showed the contrast potential of AC300Y and DC391 as shown in Table 1. Although it is inferior to the data of Example 1, it is better than the reference example (conventional example). It can be seen that a high contrast potential is shown.

From the results shown in the table above, by using nickel as the interfacial conductive layer with the photoconductive layer, the injection property of negative charges is improved, and the injection prevention property during secondary charging simultaneous photoimage exposure is maintained well. It became a state.

Images with high contrast and high density can be obtained. In addition, the generation of photocarriers is performed by the kick generation layer, and the transport of photocarriers and the transport of injected carriers are performed by the charge transport layer. Indicates image characteristics. Furthermore, since the photoconductive layer is formed by vapor deposition of selenium, it has features such as extremely superior moisture resistance compared to binder-based photoreceptors.

Note that the present invention is not limited to the above-mentioned embodiments, and can be implemented with various modifications without changing the gist.

In the above embodiment, an image forming process using simultaneous charging and light image exposure of a photoreceptor was explained, but the present invention is not limited to this, and for example, Japanese Patent Application Laid-Open No. 48-89737
After adding a negative corona charge as a monohydric charge as shown in
It is also possible to use electrophotography in which a positive corona charge is applied and then a light image is exposed. In this case, JP-A-48-8
9737 performs monohydric formation while irradiating the entire surface, but in the present invention, which has good injection properties, it is possible to sufficiently form charge pairs above and below the insulating layer even without irradiating the entire surface during primary charging. can.

As described above, according to the present invention, images with high contrast and high density can be obtained by providing a nickel conductive layer on one side of a selenium-based photoconductive layer and an insulating layer on the other side. It is possible to provide an electrophotographic photoreceptor that can.

[Brief explanation of the drawing]

FIG. 1 is a basic structural diagram of the present invention, and FIG. 2 is a structural diagram showing one embodiment of the present invention. l... Support layer 2... Nickel conductive layer 3.
3'... Selenium-based photoconductive layer 3a... Charge transport layer 3b... Charge generation layer 4...
・Transparent insulating layer Figure 1 Figure 2 Kazuo Wakasugi, Commissioner of the Japan Patent Office 1, Indication of the case, Patent Application No. 183851/1982, 2, Name of the invention, electrophotographic photoreceptor 3, Person making the amendment Patents related to the case Applicant (037) Olympus Optical Industry Co., Ltd. 4, Agent 5, Contents of spontaneous amendment 1) The scope of the claims of the present application is corrected as shown in the attached sheet. (2) On page 2, line 12 of the specification of the present application, [the part of dielectric film J is corrected to read "insulating layer." (3) The word "copying" on page 2, line 13 of the same specification is corrected to "formation." (4) "In lines 19 to 16 of page 2 of the same specification"
In general, during the latent image formation process, the part ``is corrected to ``An electrophotographic photoreceptor composed of a conductive layer, a photoconductive layer, and an insulating layer''. (5) From the 19th line to the last line of page 2 of the same specification, ``Simultaneous charging light image exposure......The electrostatic latent image power month portion [including simultaneous charging light image exposure and full-surface exposure] 1 culm causes an electrostatic latent image in the layer.'' 6) From the bottom line of page 42 of the same specification to the second line of page #¥3, “
Usually, an electrophotographic photoreceptor is made by forming... Delete the J part. /7) "It becomes high" on page 3, line 9 of the same specification vJ
Correct the part with "high." 8) The part "Decreases." on page 3, line 10 of Specification 11' is corrected to "fewer." 0th floor The part of rsusJ in the second line of page 5 of the same specification is r
Correct it to susJ. αa The part of "other" on page 5, line 12 of the same specification is corrected to "other". (19 In the same specification, page 5, line 14, “A resin-formed
・・・・・・Paste it. ” part [transparent insulating layer 4 with resin]
form. ” he corrected. ae Same specification 1 page 6 @ line 2 “temporary J part [
-I will make the next correction. (17) Same statement 1! : In the 4th line of page 6, the "Selenium-based photoreceptor" is corrected to "Selenium-based photoconductive layer." aB "Irradiation J" on page 14, line 19 and page 15, line 1 of the same specification is corrected as "irradiation J." (1) A support layer and one surface of this support layer. A conductive layer made of nickel (Ni), a photoconductive layer made of a selenium (Se)-based photoconductive material provided on the conductive layer, and an insulating layer provided on the photoconductive layer. An electrophotographic photoreceptor characterized by The electrophotographic photoreceptor according to claim 8α1, characterized in that a transport layer is provided on the conductive layer side. (3) The photoconductor layer includes a selenium-based charge transport layer containing 4QOQPPMμ of halogen. At least 50% tellurium is deposited on the conductive layer to a thickness of 70μ.
The electrophotographic photoreceptor according to claim 2, wherein a charge generation layer containing ~25% O, O, S is deposited on the selenium-based charge transport layer to a thickness of ~5μ. . (4) The electrophotographic photoreceptor described in each of claims 1 to 3, wherein the photoconductive layer is deposited at a substrate temperature of 55 to 65°C.

Claims (5)

[Claims] (1) A support layer, a conductive layer made of nickel (Ni) provided on one surface of the support layer, and a conductive layer made of nickel (Ni) provided on one surface of the support layer;
! ? 1. An electrophotographic photoreceptor comprising: a photoconductive layer made of a selenium (Se)-based photoconductive material, and an insulating layer provided on the photoconductive layer. (2) The photoconductive layer is composed of a charge transport layer made of selenium or selenium doped with nitrogen, and a charge generation layer whose main elements are selenium and tellurium. The child photographic photoreceptor according to claim ii, characterized in that it is provided on the side. (3) The photoconductive layer contains halogen at 4000 PPM or less, contains 5 to 25 tellurium, and has charge generation 1@0.05
3. The electrophotographic photoreceptor according to claim 2, wherein the selenium-based centrifugal transport layer is deposited to a thickness of 5 μm. (4) The electrophotographic photoreceptor described in each of claims 1 to 3, wherein the photoconductive layer is deposited at a substrate temperature of 55 to 65°C. (5) The conductive layer and the photoconductive layer are heat-treated at a temperature of 30 to 65° C. after forming the photoconductive layer or the insulating layer. The electrophotographic photoreceptor described above.