JPH01161370A - Electrostatic latent image forming method - Google Patents

Abstract

PURPOSE:To require no high voltage for forming an electrostatic latent image and to accomplish miniaturization, weight-saving and cost reduction by closely contacting a multi-stylus electrode on the side of a semiconductive supporting body and selectively energizing the electrode stylus of said electrode. CONSTITUTION:The multi-stylus electrode is brought tightly into contact with the side of the semiconductive supporting body 1a for an electrostatic latent image carrier equipped with a conductive layer 1b and a pyroelectric layer 1c in that order on the sheet like said body 1a. By selectively energizing the electrode stylus of the multi-stylus electrode, a current path is formed from the semiconductive layer to the conductive layer 1b. A pyroelectric layer 1c on the multi-stylus electrode is partially heated to form an electrostatic latent image on the pyroelectric layer 1c. Thus an image of halftone can be reproduced in an extremely simple process, and its density or contrast can be adjusted by a simple operation. In addition, an electrostatic image with stable density, stable contrast and satisfactory reproducibility can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention 1 (Industrial Field of Application) The present invention is directed to an electrostatic material comprising a conductor layer and a pyroelectric layer sequentially provided on a sheet-like semiconductor or conductive support. The present invention relates to a method of forming an electrostatic latent image on a pyroelectric layer of an electrom image carrier.

(Prior Art) As electrostatic latent image carriers in electrophotographic copying machines and printers, electrophotographic photoreceptors consisting of a conductive substrate and a photoconductor layer, or vJ conductive substrate dielectrics have conventionally been used. A dielectric drum consisting of layers is used.

The method of forming an electrostatic latent image on a normal electrophotographic photoreceptor according to the density of the original is to first uniformly charge the photoreceptor by corona discharge in the dark, and then irradiate the photoreceptor with a light image. This is common.

Figure 5 shows the source of electrostatic latent @potential obtained by this method.
This is a typical example of the relationship to 1 degree.

The electrostatic latent image thus formed on the photoconductor is developed using a well-known two-component magnetic developer, and the resulting tonneau image is transferred and fixed onto plain paper.The density of the copy image obtained is , the relationship is generally as shown in FIG. 6 for the original at 21 degrees, and extremely clear black and white copies can be made.

Therefore, this method is suitable for office copying machines and printers that mainly handle character images.

In addition, the method of forming Wp voltage tPj'IQ on the dielectric drum is to apply a high voltage on the dielectric drum using a multi-stylus to obtain the desired fi? Since it forms an electric Wi image, and it is difficult to modulate the high voltage application time, the electrostatic latent image becomes a binary image, and is used in output devices mainly for character images.

However, the demands on copying machines and printers have been increasing in recent years, and in particular, there is a strong demand for copying machines and printers that can faithfully reproduce halftones. Especially when expressing color images that require faithful color reproduction,
Reproduction of halftones is very important. Several methods have been proposed in the past that enable reproduction of such halftones.

For example, Lloyd F., Bean and Inan Ch.
It has been reported that by devising the structure and materials of the photoreceptor, the relationship between the latent potential and the exposure value can be adjusted, making it possible to reproduce halftones (IEEL I^S 1977
Annual Heating). This method is an excellent method from a conceptual perspective, but from a practical standpoint, there are still points that need to be improved, such as improving the reliability of the photoreceptor.

Another method is a halftone screening method. This method converts the density of the original into the size of halftone dots by, for example, placing the screen in close contact with the surface of the original or placing the screen close to the surface of the photoreceptor where the light image is focused ( R, N, Goran “lli
gh-Quality Pictorial Xer
graphic reproduction b
y Halftone Screening”
J, Appl, Photoora, Ena, 823
3-238 [1982T et al.). This method is the same as the halftone image on printed matter, and is an excellent method for reproducing medium-nl tones, but if the original to be copied is formed with a halftone image, a so-called moiré phenomenon will occur. It is not possible to handle all types of manuscripts.

Another method is limited to the case of a photoreceptor with a three-layer structure consisting of a conductive substrate, a photoconductor layer, and a transparent insulator layer, but is a uniform primary method? 1) If the second light is emitted at the same time as the light image irradiation? ! i! A method for forming an electrostatic latent image whose basic process is a series of steps of (polarity opposite to the primary charging) and uniform light irradiation is disclosed in, for example, Japanese Patent Laid-Open No. 59-30560. This method is considered to be one of the best methods for forming electrostatic latent images that can reproduce halftones, but it is extremely complicated, requires large equipment, and is expensive. The problem is that it cannot be avoided.

Furthermore, as an electrophotographic method that can express halftones, equity [1
As described in Japanese Patent No. 57-56070, by simultaneously irradiating a light image and irradiating corona zones 111i & 3 and bias light onto an electrophotographic photoreceptor having a photoconductor layer, and adjusting the amount of bias light. A method of adjusting the contrast and density of a halftone image has also been proposed. However, with this method, it is difficult to maintain the light e of the bias light stably due to problems such as the stability of the light source, which causes poor reproducibility of image contrast, last, and density. .

Moreover, in this method, it is important that the light image illumination DJ position and the bias light illumination A4 position on the photoreceptor completely match in order to produce a good image without unevenness in contrast or density. The disadvantage is that position adjustment is difficult.

(Problems to be Solved by the Invention) The present invention has been made to solve the above-mentioned problems, and it is possible to reproduce halftones with an extremely simple process, and to reproduce images by in-process operations. One object of the present invention is to provide a method for forming an electrostatic latent image in which the density and contrast of the electrostatic latent image can be adjusted and the density and contrast are stable and reproducible.

[Structures of the Invention] (Means for Solving the Problems) According to the method for forming an electrostatic latent image of the present invention, the above object is achieved by forming a conductive layer and a pyroelectric layer on a sheet-like semiconductive support. +141a for electrostatic latent images provided in this order. A multi-needle electrode is brought into close contact with the semiconductive support. (1) Many! 1 electrode electrode S
1 is selectively energized to form a current path from the semiconductive layer to the conductive layer, partially heating the pyroelectric layer on the multi-needle electrode, and creating an electrostatic latent on the pyroelectric layer. Achieved by forming an image.

Hereinafter, the method for forming an electrostatic latent image of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a conceptual diagram showing an example of the basic configuration of an apparatus to which the electrostatic latent image forming method of the present invention is applied.

This device includes an electrostatic latent image recording section consisting of an electrostatic latent image carrier 1 in the form of an endless tape, a multi-needle electrode 2 for writing a latent image on the electrostatic latent image carrier, and A common electrode 3 receives a current flowing into the latent image carrier 1.

The electrostatic latent image carrier is, for example, as shown in FIG.
A conductive layer 1b is provided on the outside of an endless semiconductive support 1a, and a pyroelectric layer 1C is provided thereon. Note that, if necessary, a thin layer of silicone having good electrical resistance and wear resistance may be further formed on the pyroelectric layer 1C.

The semiconductive support layer of the electrostatic latent image carrier is a resin selected from the group consisting of thermoplastic resins or thermosetting resins, and IJ conductive fine powder selected from the group consisting of carbon black and graphite. The surface resistance becomes 10' at room temperature.
It is possible to use a semi-conductive bamboo material which is 108Ω and generates heat without being destroyed by discharge when energized.

Further, the conductor layer 1b of the electrostatic latent image carrier is made of a metal layer or a metal oxide film, and has a surface resistance of 10 at room temperature.
A conductive material having a resistance of -2 to 10'Ω can be used.

Furthermore, as the pyroelectric layer 1c of the r# electroelectric 2M carrier,
Polyvinylidene fluoride, copolymers of vinylidene fluoride and ethylene trifluoride, copolymers of vinylidene fluoride and ethylene tetrafluoride, copolymers of vinylidene cyanide and other heptamers, etc. Electrically conductive resin or PZT (Pb2
Zr03, PbTi01) Ceramics, PLZT
(PI)2 zro 3 , PbTi03 , La20
3) Pyroelectric ceramics such as Ceramilas and BaTi0
3. Pyroelectric crystal fine powder selected from the group consisting of inorganic pyroelectric crystal fine powder such as LiTa03, LiNb03, quartz, organic pyroelectric crystal fine powder such as Rochelle salt, triglycine sulfate, etc., is added to thermoplastic resin. Alternatively, a material dispersed in a resin selected from the group consisting of thermosetting resins can be used. An electrostatic latent image carrier made of these materials is used by converting the pyroelectric layer into an electret or aligning the direction of spontaneous polarization by a polarization operation such as poling.

As shown in FIG. 1, in this embodiment, an electrostatic latent image carrier 1 is stretched over the outside of a multi-needle electrode 2 and a common electrode 3 with a semiconductive support 1a inside, The image carrier 1 has many! It moves continuously from the l electrode 2 to the common electrode 3 and then roughly back to the multi-needle electrode 2. At this time, the common electrode 3 also functions as a heat sink for the electrostatic latent image carrier.

That is, first, the multi-needle electrode 2 is brought into close contact with the semiconductive support 1a side of the electrostatic latent image carrier 1, and a semi-conductor is formed between the multi-needle electrode 2 and the conductive layer 1b in response to an external recording signal. sexual support 1
A current is selectively passed through the semi-conductive support 1a, and the semi-conductive support 1a generates heat due to the electrical resistance of the semi-conductive support 1a. Therefore, the pyroelectric layer 1C on the semiconductive support 1a
is heated in response to a recording icon from the outside, and an electrostatic latent image is formed on the pyroelectric layer 1C by this heat. At this time, the current flowing into the conductor layer 1b of the electrostatic latent image carrier 1 is
The liquid flows again into the common electrode 3 in close contact with the electrostatic latent image carrier 1 through the semiconductive support 1a. However, since the common electrode 3 has a much larger area than the multi-needle electrode 2, no heat is generated in this common electrode 3 portion.

The electrostatic il image formed in this way is developed, transferred, fixed, and
After a process such as cleaning, it is visualized and recorded. Then, the electrostatic groove@carrier 1 is cooled 11 through the common electrode 143, and is continuously transferred to the electrostatic latent image recording section again, and the above steps are repeated.

Another configuration of the present invention is to configure the semiconductive support portion and the conductive layer portion of the electrostatic latent image carrier to be wider than the pyroelectric layer portion, thereby exposing the conductive layer portion and forming a multi-needle electrode. Current flowing into the electrostatic latent image carrier.

It is also possible to flow directly from the conductor layer to the common electrode. Conversely, by configuring the pyroelectric layer portion and the conductive layer portion to be wider than the semiconductive support portion, the conductive layer can be similarly exposed and flowed into the electrostatic latent image carrier from the multi-needle electrode. It is also possible to flow the current directly from the 5ttt body layer to the common electrode.

The method for forming an electrostatic latent image of the present invention provides an electrostatic latent image carrier comprising an isoelectric layer provided on a sheet-like semiconductive support, and a pyroelectric layer further provided on the conductive layer. Using a multi-needle electrode, the multi-needle electrode is brought into close contact with the semi-conductive support, and a current path is formed from the semi-conductive layer to the conductor layer by applying electricity to the multi-needle electrode, thereby forming a focal layer near the multi-needle electrode. It is sufficient that the process of heating and forming an electrostatic latent image on the pyroelectric body is an essential process, so the specific structure of the process is as shown in Figure 1 above. There are no restrictions whatsoever.

(Function) In the present invention, many! The llt electrode is brought into close contact with the semiconductive support side of the electrostatic S image carrier, and a current is selectively applied between the multi-needle electrode and the conductive layer through the semiconductive support in response to an external recording signal. , the semiconductive support is configured to generate heat due to the electrical resistance of the semiconductive support. Therefore, the pyroelectric layer of the semiconductive support is heated in response to an external recording signal, and this heat forms an electrostatic latent image on the pyroelectric layer.

The electrostatic latent image thus formed is visualized and recorded through processes such as development, transfer, qualitative, and cleaning. Then, the electrostatic latent image bearing member is cooled through the common electrode portion, and is continuously transferred again to the static and f5 latent image recording sections, and the above steps are repeated.

(Example) Example 1 FIG. 3 is a diagram conceptually showing the configuration of a recording apparatus to which this example is applied. In this figure, the same parts as in FIG. 1 are given the same reference numerals as in FIG. 1. In this device, an electrode in which 8/+U wires each having a wire diameter of 60 μm are arranged in a straight line is used as the multi-21 electrode. Then, in response to an external signal, the control circuit 10 applies a voltage of +20 V from the power source 11 to the multineedle electrode 2 as a pulsed recording signal. The common electrode 3 is grounded using a stainless steel rod having a diameter of 3011 mm, and receives current from the multi-needle electrode through the electrostatic latent image carrier 1. At this time, the electrostatic latent image formed on the heated pyroelectric layer uses a two-component magnetic developer.

The image is developed by a developing device 4. The transfer device 5 statically transfers the developed toner on the image carrier 1 onto a transfer paper.

The fixing device fixes the developed toner transferred in step 6 onto the transfer paper. On the other hand, the electrostatic latent image carrier is cleaned in the cleaning section 7, the temperature of the electrostatic latent image carrier is equalized at the common electrode 3, and the above process is repeated again.

The electrostatic S image carrier 1 is formed on a semiconductive support (Toshi Co., Ltd., conductive TX-1 film, thickness 50 μm, surface resistivity 800 Ω) in which carbon black is dispersed in a para-based wholly aromatic polyamide resin. Aluminum was deposited to an average thickness of 1,000 mm, and a polyvinylidene fluoride layer containing 10 volume percent of Pl ceramic particles was applied thereon as a pyroelectric layer to a thickness of 10 μ-. C is used as an electrostatic latent image carrier by polarizing it under an electric field at 100°C for 1 hour.

Under the above conditions, the electrostatic latent image carrier 1 has a large amount of ! Electricity was applied from the electrode 2 to heat the pyroelectric layer in response to an external recording signal.

At this time, by controlling the voltage pulse width of the recording signal applied to the multi-needle electrode 2 by the control device 10, the temperature of the electrostatic latent image carrier 1 is controlled to be between room temperature and 50°C. Then, a halftone electrostatic latent image was formed on the electrostatic latent image carrier. By developing this electrostatic latent image and transferring and fixing it onto transfer paper, an image with good halftone reproducibility is created! We were able to.

Embodiment 2 FIG. 4 is a diagram conceptually showing the configuration of a recording apparatus to which this embodiment is applied. In the figure, FIG. 1 and Example 1
815 minutes, which is the same as in FIG. 3, are given the same reference numerals. In this device, the multi-needle electrode 2 has a wire diameter of 30
An array type electrode in which 16 μpus wires were arranged in a staggered manner was used. and control circuit 1 according to external signals.
0, a voltage of +30 V from the power source 11 is applied to the multiple electrodes 2 as a pulsed recording signal. The common electrode 3 is made of a stainless steel rod with a diameter of 3 mm, and is in close contact with the exposed conductor layer at both ends of the electrostatic latent image carrier, and the conductor layer is grounded. At this time, the electrostatic latent image formed on the heated pyroelectric layer is developed by a developing device 8 using a liquid developer. The transfer device 5 is an electrostatic latent image carrier 1
Transfer the upper liquid developer onto the transfer paper.

The developer transferred by the fixing device 6 is fixed onto the transfer paper. On the other hand, the electrostatic latent image carrier is cleaned by the cleaning device 7, the temperature of the electrostatic latent image carrier is equalized at the common electrode 3, and the above process is repeated again.

The electrostatic latent image carrier 1 is made by depositing a thick β-type crystal of a copolymer of vinylidene fluoride and ethylene trifluoride (80:2G) on a semiconductive support and a conductive layer similar to those in Example 1. A material formed to a thickness of 10 μm and polarized at 100° C. and 308 V/m for 1 hour was used.

The electrostatic latent image carrier 1 was prepared in the same manner as in Example 1 under the above conditions.
Electricity was applied through the multi-needle electrode 2 to heat the pyroelectric layer in response to external recording signals. At this time, by controlling the voltage pulse width of the recording signal applied to the multi-needle electrode 2 by the control device 10, the temperature of the electrostatic WI@carrier 1 is adjusted to 50°C from room temperature to room temperature.
The temperature was controlled to be between 0.degree. By developing this electrostatic latent image and transferring and fixing it onto transfer paper, it was possible to obtain ti[1fIA with good halftone reproducibility.

[Effects of the Invention] As is clear from the explanation of F, the method for forming an electrostatic latent image of the present invention differs from conventional electrophotographic methods and electrostatic recording methods in that a high voltage is used to form an electrostatic latent image. Not only is it safe, easy to reduce size, weight, and cost, but it is also possible to form an electrostatic latent image with halftones that matches the development characteristics of the developing device, and can be used with any developing method. (-component magnetic development method, two-component magnetic development method, -component non-magnetic development method, and development method using a liquid developer). As a result, the reliability of the obtained device is extremely high, and its industrial value is extremely high.

[Brief explanation of the drawing]

Fig. 1 is a conceptual block diagram showing the basic structure of the method of the present invention, Fig. 2 is a front view of an example of an electrostatic latent image carrier, and Figs. 3 and 4 are examples of the present invention. FIG. 5 is a diagram showing the relationship between image density and electrostatic latent image potential in J3 according to the conventional method, and FIG. 6 is a diagram showing the relationship between image density and copy image wetness. 1... Electrostatic latent image carrier 1a... Semiconductive support 1b... Conductor layer 1C... Pyroelectric layer 2 ......Multi-needle electrode 3...Common electrode 4...S device for two-component magnetism 5...
...Transfer device 6...Fixing device 7...Cleaning device 8...
. . . Liquid developer developing device 10 . . . Control circuit 11 . . . Power source No. 1 Figure 2

Claims (3)

[Claims] (1) A multi-needle electrode is brought into close contact with the semiconductive support side of an electrostatic latent image carrier comprising a conductive layer and a pyroelectric layer provided in this order on a sheet-like semiconductive support. By selectively applying electricity to the electrode needles of the multi-needle electrode, a current path is formed from the semiconductive layer to the conductive layer to partially heat the pyroelectric layer on the multi-needle electrode. 1. A method for forming an electrostatic latent image, the method comprising forming an electrostatic latent image thereon. (2) A patent characterized in that the temperature of the pyroelectric layer is controlled by modulating the electrical energy applied to the multi-needle electrode, and the amount of charge generated on the pyroelectric layer is modulated. A method for forming an electrostatic latent image according to claim 1. (3) An electrostatic latent image according to claim 1 or 2, wherein the sheet-like semiconductive support is endless and has a conductive layer formed inside thereof. How to form.