JPH01221265A - Image forming device - Google Patents

Abstract

PURPOSE:To output many sheets of the same copy at a high speed and to enable a photosensitive material to be stably used again, by a method wherein the photosensitive material contains a thermochromic layer, and a photoconductive layer, and erazing of an image is confirmed based on a reflection scattered amount of light of the photosensitive material. CONSTITUTION:A photosensitive material 1 is of an endless belt state, and forms an image moving in the arrow 2 direction. A thermal head 3 as a heat application means, a unit 5 emitting uniform light, an infrared heating lamp 1 as an image erazing means of a thermochromic layer 15, a light beam emission means 12, and a light receiving sensor 13 are arranged inside the belt. The thermochromic layer 15 is of resin in which organic low molecular material particle is dispersed, and is formed by coating on a transparent substrate 16 to be dried. A transparent conductive material layer 17 is formed on a surface contrary to the thermochromic layer 15 of the transparent substrate 16, and a photoconductive material layer 18 is established thereon. Since an initial state of the thermochromic layer 15 is transparent and is of a state wherein light is not scattered, by detecting return to the initial state by a scattering amount of light, the detection can be performed at high sensitivity by using intensive light.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an image forming apparatus using a novel image forming method using a novel photoreceptor applying electrophotographic technology.

[Prior Art] A conventional photoreceptor has a photoconductive layer formed on a conductive substrate such as A1. In addition, conventional image forming methods include a step of charging the surface of the photoconductive layer, irradiating the surface of the photoconductive layer with focused light such as a laser beam while modulating the intensity, or further scanning the surface of the photoconductive layer to charge the light irradiated area. It included a step of erasing the image and forming an electrostatic latent image.

[Problem M to be Solved by the Invention] However, in an image forming apparatus using such a conventional photoreceptor and image forming method, an electrostatic latent image must be formed using a laser beam or the like every time one sheet is printed. In this case, there is a limit to the intensity of the laser beam, and there is also a limit to the intensity modulation speed, so it is quite impossible to quickly output multiple copies of the same manuscript. In addition, Xerox Corporation has proposed an image forming device using xerolithography technology for processing a large number of sheets, but this method requires maintenance and increases running costs because the photoreceptor is disposable. .

Therefore, in order to solve these conventional problems, the present invention has developed a new photoreceptor that is reusable and can output multiple sheets of the same original in a simple and quick process once image formation is performed, and a new image forming method. An object of the present invention is to provide an image forming apparatus using a method.

[Means for Solving the Problems] In order to solve the above problems, the photoreceptor of the image forming apparatus of the present invention is characterized in that it includes a thermochromic layer and a photoconductive layer. Further, the image forming apparatus of the present invention includes the photoreceptor, a heat applying means for forming an opaque image on the entirely transparent thermochromic layer, a means for forming an electrostatic latent image using the thermochromic layer as a plate, and the electrostatic latent image. A means for visualizing an image, a means for heating the entire surface of the thermochromic layer for erasing the image on the thermochromic layer, and a means for confirming the erasure of the image by the amount of reflection and scattering of light from the photoreceptor. Features.

[Function] Once an image is formed on the thermochromic layer by heat, the photoreceptor configured as described above uses the image formed on the thermochromic layer by uniform overall exposure as a plate to form an image many times on the photoconductive layer. It is possible to perform development and quickly output multiple copies of the same original. Furthermore, since the initial state of the thermochromic layer is transparent and does not scatter light, high-sensitivity detection using strong light is possible by detecting the return to the initial state based on the amount of light scattering. Therefore, since the thermochromic layer can be completely reversible with minimal heat application to the photoreceptor, there is little deterioration of the photoreceptor and the photoreceptor can be reused any number of times. 1 Hereinafter, the details of the present invention will be illustrated by examples.

[Embodiment] FIG. 1 shows a schematic diagram of an embodiment of an image forming apparatus of the present invention. In this example, a photoreceptor 1 is in the shape of an endless belt, and arrow 2
A thermal head 3 is a means for applying heat to the inside of the belt, a unit 5 for generating uniform light, an infrared heating lamp 11 is a means for erasing an image of the thermochromic layer, and a light beam generating means forms an image while moving in the direction of the belt. 12. The light-receiving sensor 13 is arranged, so space is used efficiently and the device is compact.

FIG. 2 shows the structure of the photoreceptor 1 shown in FIG. 1 according to the present invention. 15
The thermochromic layer is the one shown in the 4th Non-Impact Printing Technology Papers, p. 57-60, and has a thickness of 1μ.
It is made by dispersing organic low-molecular substance particles of about 100 µm in size in a resin, and has a thickness of about 10-20 µm, with a resin protective layer provided on its surface. 10- like PET, aramid
It is formed by coating and drying on a transparent substrate 16 of about 50 μm. A transparent conductor layer 17 is formed on the surface of the transparent substrate 16 opposite to the thermochromic layer 15 . Transparent conductor layer 1
The layer 7 is formed by forming a TO layer or a semi-transparent Cr or Au metal layer by sputtering or vacuum evaporation. A photoconductor layer 18 is provided on the transparent conductor layer 17. The photoconductor layer 18 is preferably an organic photoreceptor layer, and the entire layer must be transparent. General organic photoreceptors satisfy this condition. As an organic photoreceptor, a functionally separated type consisting of two layers, a charge generation layer and a charge transfer layer, exhibits good characteristics.

The charge generation layer is a film in which phthalocyanine or azo pigment particles are dispersed in a resin. The charge transfer layer is a film made by dissolving hydrazone-based, stilbene-based, benzidine-based, or other materials in a resin. The total film thickness is 1
It is about 0-20 μm.

In the case of the photoreceptor having this configuration, the thermochromic layer can reversibly take on a transparent state and an opaque state, and a visible image can be formed on the thermochromic layer using heat application means such as a thermal head. This point will be explained using FIG. The initial state of room temperature is completely transparent. When heated with a thermal head or the like to raise the temperature to T3, only the heated portion becomes slightly opaque, and when the temperature is then returned to room temperature, it becomes completely opaque and a visible image can be obtained. By heating the entire thermochromic layer to T2 and then returning it to room temperature, the entire surface becomes transparent and can be returned to its initial state. This cycle can be repeated and the thermochromic layer can be shaped over and over again. By using this visible image as an exposure mask, it is possible to pattern-expose the photoconductor any number of times by exposing the entire surface of the photoconductor to light from the thermochromic layer side. Therefore, once an image is written, the photoreceptor stores the image, and the same electrostatic latent image can be easily formed, making it possible to output a plurality of images.

The operation of the image forming apparatus shown in FIG. 1 will be explained based on the image forming process diagram shown in FIG. A circumchromic layer 15 is provided inside the photoreceptor belt 1. First, the thermochromic layer 15 is made transparent. The thermal head 3 is brought into contact with the thermochromic layer in this state, and electricity is applied to the thermal head 3 to generate heat according to the image desired to be formed. This heat makes the thermochromic layer 15 partially opaque. Part 19
is formed and an image is written (FIG. 4(A)). Next, the entire surface of the photoconductive layer 18 is uniformly charged by a corona ion generator 4 of a corotron or scorotron (FIG. 4(B)).
), in this example it is negatively charged. Furthermore, in this state, uniform light is generated from the thermochromic layer side onto the photoreceptor by the entire surface exposure lamp 5. Uniform light 20 generated
When irradiated with , the photoconductive JW 18 is exposed in a pattern. In other words, the electrical charge in the portion of the photoconductive layer corresponding to the portion heated by the thermal head is eliminated (FIG. 4(C)).
In this case, the entire surface is uniformly exposed, there is no need to form a beam, etc., the amount of light can be sufficiently secured and maintained with a small output light source, and the electrostatic latent image obtained at order 0 is transferred to the developer 6. The image is visualized by normal development with the positive toner 21 (FIG. 4(D)). Developer device 6 may be a one-component or two-component developer used in conventional electrophotographic processes. After that, the recording paper 7 is brought into contact with the photoreceptor, and negative ions are irradiated from the back side of the recording paper by the corotron 8 to transfer the toner 21 on the photoreceptor to the recording paper 7 (FIG. 4(E)), and between the heat rollers 9. The image formation is completed by performing fixing processing. When outputting multiple sheets, return to step (B) and repeat the process to output the required number of sheets. When the zero image output is finished, the entire thermochromic layer is heated to T2 with the infrared heating lamp 11 to return the entire surface to transparency, and the next step is performed. Prepare for image formation. Infrared heat lamps have a small heat capacity and a quick response, making heating control very easy.

At this time, the thermochromic layer returns to its initial state where the entire surface is transparent. If this is not done, the next image formation will not be possible. Taking into account changes in the photoreceptor over time, it is not possible to reliably return it to its initial state just by controlling the surface temperature of the photoreceptor. Therefore, in the present invention, the amount of light reflected and scattered by the photoreceptor is detected and the amount of light reflected and scattered is reduced to zero. The light output of the infrared heating lamp is controlled in this manner.For this purpose, a light beam generating means 12 consisting of a laser or a tungsten lamp, and a light receiving sensor 13 are mounted on the thermochromic layer side of the photoreceptor 1.
I'm doing t. The light emitted from the light beam generating means 12 is made to be parallel light. Since the photoreceptor is transparent in its initial state, the light emitted from the light beam generating means either passes through the photoreceptor without being scattered by the photoreceptor, or is reflected at a predetermined angle.

If the light receiving sensor 13 is placed at a position where the above reflected light is not detected, the amount of light detected by the light receiving sensor becomes zero in the initial state. By sufficiently increasing the light beam output intensity, the detection accuracy of the transparent state can be increased even if the light beam output varies, so that the initial state can be reliably set. Further, by adopting this detection method, it is not necessary to heat the photoreceptor more than necessary, so that performance deterioration due to heating can be minimized to zero, and reliability of the photoreceptor can be ensured. The light beam generating means 12 and the light receiving sensor 13 are arranged after the infrared heating lamp 11 in the example shown in FIG. Thereafter, the charge is removed from the entire surface of the photoreceptor using the charge removal lamp 14, and the image forming process is completed.

[Effects of the Invention] As described above, the image forming apparatus of the present invention is particularly capable of outputting multiple sheets of the same original at high speed, and furthermore, since the photoreceptor can be reused stably, running costs are low and maintenance is not required. We can provide printing machines.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of an image forming apparatus according to the present invention. FIG. 2 is a sectional view showing the structure of a photoreceptor according to an embodiment of the present invention. FIG. 3 is a characteristic diagram showing the state of phase change of the thermochromic layer of the photoreceptor of the present invention. FIG. 4 is an image forming process diagram showing the operation of the image forming apparatus of the present invention. 1...Photoconductor 2...Movement direction of photoconductor 3...Thermal head 4...Corona ion generator 5...Full surface exposure lamp 6...Developer 7...Recording paper 8... ... Corotron 9 ... Fixing device 10 ... Cleaner 11 ... Infrared heating lamp 12 ... Light beam generating means 13 ... Light receiving sensor 14 ... Static elimination lamp 15 ... Thermochromic layer 16 ... Transparent substrate 17 ... Transparent conductor layer 18... Photoconductive layer 19... Opaque portion 20... Uniform light 21... Toner and above Applicant Seiko Epson Co., Ltd. Agent Patent attorney Tsutomu Mogami (1 person) 4.) hj finished Raw number y Figure 1 Figure 3

Claims (1)

[Claims] 1. A photoreceptor including a thermochromic layer and a photoconductive layer that reversibly change between a transparent state and an opaque state, a heat application means for forming an opaque image on the entirely transparent thermochromic layer, and the thermochromic layer used as a plate. means for forming an electrostatic latent image; means for visualizing the electrostatic latent image; means for heating the entire surface of the thermochromic layer for erasing the image on the thermochromic layer; An image forming apparatus characterized by comprising: means for determining the amount of reflection and scattering.