JPH04372963A - Image forming device and image formaiton - Google Patents

Abstract

PURPOSE:To allow reuse and simply copy the same image on multiple sheets by providing a memory layer with a layer (thermo-chromic layer) mainly made of an organic low-molecular material and reversibly changed with transparency by temperature. CONSTITUTION:A thermo-chromic layer 1 is dispersed with organic low- molecular material grains in resin, and a resin protective film is generally formed on the surface. It is coated and dried on a transparent base 2 such as PET and aramide to form the thermo-chromic layer 1. The thermo-chromic layer 1 can be reversibly set to the transparent state and nontransparent state, and a visible image can be obtained on the layer 1 with a heat applying means such as a thermal head 5. An image is formed by heat on the thermo-chromic layer 1, and the image is exposed on an electrified photoreceptor 3 to form an electrostatic latent image. The visible image thus formed is utilized as a mask and exposed from the back side of the image formation of the thermo- chromic layer 1, and the same image can be exposed many times on the photoreceptor 3.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to image forming, and particularly to an image forming apparatus and an image forming method provided with a recording medium having a memory function.

0002

[Prior Art] In a conventional image forming method, the surface of the photoconductive layer of a photoreceptor is charged, and a laser beam or the like is focused to print an original on this surface. This is accomplished by irradiating light while modulating its intensity, or by scanning the surface of the photoconductive layer to erase the charge on the light irradiated area and form an electrostatic latent image on the photoreceptor.

0003

In the above-mentioned conventional image forming method, it is necessary to form an electrostatic latent image on the photoreceptor using a laser beam or the like for each printing on the photoreceptor. In this case, there is a limit to the intensity of the laser beam, and it is quite impossible to rapidly form images on multiple sheets of the same document.

[0004] Further, an image forming apparatus using xerography technology has been proposed for processing a large number of sheets, but this method has the disadvantage of high running costs because the photoreceptor is disposable.

[0005] In order to solve the above-mentioned conventional problems, the present invention provides a new image forming method and apparatus that can be reused and that can easily and quickly make multiple copies of the same image once an image is formed. The purpose is to provide

[0006]

[Means for Solving the Problems] In order to solve the above problems, the inventors of the present invention, as a result of intensive research, formed an image of document read data on a recording medium having a thermochromic recording layer by heat, and exposed this formed image to a recording medium having a thermochromic recording layer. By forming an electrostatic latent image on the body surface, the image of this thermochromic layer acts as a plate, and when copying the same original, it is possible to make multiple copies with a single reading operation. They discovered that this recording medium can be reused because the thermochromic layer is reversible, and completed the present invention.

A first invention of the present application is an image forming apparatus characterized in that a recording medium having a thermochromic layer is provided.

The second invention of the present application is a step of forming an image by heat on the surface of the thermochromic layer of a recording medium having a thermochromic layer, a step of uniformly charging the surface of a photoreceptor, and a step of uniformly exposing the photoreceptor to light from the recording medium side. This image forming method includes the step of forming an electrostatic latent image. In addition, in this method, when the copy original size is A4 (vertical) or less and the number of copies set is plural, a plurality of original images are formed on the recording medium.

The image forming apparatus according to the first aspect of the present invention is an image forming apparatus for forming an electrostatic image on a photoreceptor, and includes a recording member having a thermochromic layer and a photoreceptor. More specifically, it consists of a part that forms an image of external information such as a document on a recording medium, and a part that forms this formed image as an electrostatic latent image on a photoreceptor. The part that forms an image of external information on a recording body consists of a means for applying heat to an image of external information and a recording body having a thermochromic layer, and the part that forms an electrostatic latent image on a photoconductor consists of a photoconductor, a photoconductor, and a recording body that has a thermochromic layer. It consists of means for uniformly charging the body and means for uniformly exposing the photoreceptor. The recording medium and the photoreceptor are arranged to face each other directly.

[0010] The recording medium having a thermochromic layer of the present invention has the structure shown in [Fig. 1], and the thermochromic layer 1 in [Fig. The one shown on the page is one in which organic low-molecular substance particles of about 1 μm are dispersed in resin.
The thickness is approximately 10 to 20 μm, and a resin protective film is generally formed on the surface. This is coated and dried on a transparent substrate 2 of about 100 to 200 μm such as PET or aramid. This thermochromic layer has the property of being able to reversibly take on a transparent state and an opaque state,
A visible image can be obtained on this layer by using heat application means such as a thermal head. Regarding the reversible characteristics of the transparent state and opaque state in this thermochromic layer [Figure 2]
This is explained by: The initial state at room temperature (T1) is assumed to be completely opaque, and when the temperature is raised to T2 by heat application, it becomes transparent, and even after it is returned to room temperature, it remains transparent and a visible image can be obtained. (solid line). The entire thermochromic layer is heated to T3 and then to room temperature (T1)
By returning it to the initial opaque state, the whole becomes opaque (dotted line). By repeating this cycle, images can be formed on the thermochromic layer any number of times. By using the visible image thus formed as a mask and exposing the thermochromic layer from the back side where the image is formed, the same image can be exposed on the photoreceptor any number of times. Therefore, once an image is written on a recording medium, the recording medium stores this image, and multiple sheets of the same image can be output. The first aspect of the present invention is characterized in that the recording medium having the above thermochromic layer is used in an image forming apparatus. As the means for applying heat to the external information image, a commonly used means such as a thermal head can be used.

The portion where the formed image formed on the thermochromic layer is formed as an electrostatic latent image on the photoreceptor is provided with a means for uniformly charging the photoreceptor, such as a corona ion generator (scorotron), or a means for uniformly charging the photoreceptor. It consists of a full-surface exposure lamp that exposes the formed image onto the photoreceptor from the back side. In addition, when visualizing by charged particles using the image forming apparatus of the first invention of the present application, an ordinary electrophotographic apparatus can be added to form an electrophotographic apparatus. As the photoreceptor, a photoreceptor in which a photoconductor layer is provided on a transparent conductor layer, which is used in general electrophotographic devices, can be used.

[0012] The image forming method of the second invention of the present application includes forming an external information image on the surface of the thermochromic layer of the recording medium having the above-mentioned thermochromic layer by heat application means;
In this method, the image formed on the recording medium is uniformly exposed to light from the back side of the thermochromic layer of the recording medium on a photoreceptor whose surface is uniformly charged to form an electrostatic latent image. Note that by taking into consideration the length of the recording medium and the size of the external information source (original), it is possible to form a plurality of images of external information on the recording medium. Furthermore, when an image is formed using a document or the like that is smaller than the effective surface of the recording medium, a margin is created on the surface of the recording medium, resulting in a wasted area. Therefore, by forming an image on the original in this blank area and forming a plurality of images on the belt of the recording medium, several copies can be obtained in one rotation of the recording medium. Therefore, high-speed copying becomes possible. In order to create multiple images on the belt of the recording body 12, the length of the recording body is known in advance, so by managing the feed time for one revolution of the belt, the length of the recording body can be determined in advance. , and then forms multiple images on the belt depending on the size of the document and the remaining amount of the recording medium on the belt. In this case, the plurality of images may not be the same image. For example, when copying two types of A4 portrait originals, images of the two types of A4 portrait originals are formed on the belt of the recording medium. As a result, during a copying operation, two types of A4 portrait documents can be copied for each rotation of the photoreceptor. Furthermore, if the same document is used, two identical images of the A4 portrait document will be formed on the belt of the recording medium. When copying with this, two copies of an A4 portrait original can be made for each rotation of the recording belt. This method allows for faster copying than usual.

[0013]

EXAMPLES The image forming apparatus and method of the present invention will be explained by way of examples. Example 1 (Image Forming Apparatus) [FIG. 3] is a schematic diagram showing an example of an image forming apparatus according to the first invention of the present application. The recording medium 12 having a thermochromic layer is shaped like an endless belt, and various units such as a writing device 5, a full exposure lamp 13, and an erasing heater 17 are arranged around the belt inside the belt. Note that the writing device 5 used here is a line-type thermal head, has no moving parts, is highly reliable, and is compact. Erase heater 1
7 uses an infrared lamp heater. Infrared lamp heaters are suitable because they have a quick response and high controllability, and do not overheat the photoreceptor. Other units generally used in image forming apparatuses for electrophotographic processes are used. The recording body 12 is in the form of an endless belt, and the maximum original size for copying is A3.
Therefore, it is A3 (420 mm) or more. A photoconductor 3 is provided directly facing the recording medium 12, and various units such as a corona ion generator (scorotron) 7, a static elimination lamp 16, a cleaner 15, a developer 14 are arranged around the photoconductor.
is located. A corotron 11 for transferring a visualized electrostatic latent image on the photoreceptor 3 to a recording paper 10 placed in contact with the lower part of the photoreceptor 3 is provided on the back side of the recording paper 10, and a fixing device 4 for visualizing toner is provided on the back side of the recording paper 10. It is provided.

Example 2 (Image Forming Method) An example of implementing the image forming method of the second invention of the present application will be explained with reference to FIG. 3. An image of a document is formed on a thermochromic layer of an endless recording medium 12 which is rotated in a direction 19 by a thermal head 5. The image formed on the recording body 12 is formed as an electrostatic latent image on the photoreceptor 3 whose surface is uniformly charged by the scorotron 7 and rotates in the direction 18 and faces the recording body by irradiation with the entire surface exposure lamp 13. The developing device 14 performs reversal development using negative toner, the corotron 11 transfers the toner to the surface of the recording paper 10, and the fixing device 4 fixes the copied image on the recording paper. Incidentally, after the photoconductor 3 transfers the copy image onto the recording paper 10, the cleaner 15 and the static elimination lamp 16 return to the initial state again, and the above operation is repeated for the desired number of copies. After copying is completed as described above, if the formed image is to be erased from the recording medium, the thermochromic layer is heated by the erasing heater 17 to erase the formed image. As above,
After returning to the starting state again, copy the image of the next document using the same operation.

[0015]

[Operation] The operation of the present invention will be explained step by step with reference to FIG. 4. As shown in [Figure 4-A], the thermochromic layer 1
When writing is performed on the surface of the thermochromic layer 1 by the thermal head 5, the corresponding portion of the thermochromic layer becomes transparent 6 by heating, and a visible image is formed on the thermochromic layer 1. As shown in FIG. 4-B, the recording medium 3 having this formed image is placed directly in front of the photoreceptor 3 whose entire surface is uniformly charged by a corona ion generator (scorotron) 7, and the entire surface is exposed from the thermochromic layer 1 side. When uniform light 8 is irradiated by the lamp 13, an image formed on the recording medium is exposed onto the photoreceptor 3. In other words,
The charge on the photoreceptor portion corresponding to the opaque portion that was not heated by the thermal head 5 is eliminated [Fig. 4-C
). The electrostatic latent image thus formed on the photoreceptor 3 is visualized by reversing development with negative toner 9 [FIG. 4-D]. After that, the recording paper 10 is brought into contact with the photoreceptor 3, and the corotron 1 is placed on the back side of the recording paper 10.
Toner 9 on the photoreceptor is irradiated with positive ions by 1
is transferred to the recording paper 10 [FIG. 4-E].

[0016]

As described above, the present invention enables the number of copies to be easily, uniformly, and quickly produced by forming an original image once when obtaining the same copy, and also makes it possible to copy multiple original images at the same time. can be formed and copied in the same way. Furthermore, in the case of the next copy, by heating the recording medium, another original image can be successively formed and copied, making this an extremely useful invention.

[Brief explanation of the drawing]

FIG. 1 is an enlarged longitudinal cross-sectional view of a recording medium used in the present invention.

FIG. 2 is a drawing showing changes in transparency due to heat of a thermochromic layer that is a structure of a recording medium.

FIG. 3 is an overall view of the image forming apparatus of the present invention.

FIG. 4 is a schematic diagram illustrating the operation of the invention;

[Explanation of symbols]

1 Thermochromic layer
2 Transparent substrate 3 Photoreceptor
4 Fusing device 5 Writing device 6
Transparent part 7 Corona ion generator
8 Uniform light 9 Toner
10 Recording paper 11 Corotron
12 Recording body 13 Full exposure lamp
14 Developing device 1
5 Cleaner
16 Static elimination lamp 17 Erasing heater 18 Photoconductor moving direction 19 Recording body moving direction

Claims (3)

[Claims] 1. An image forming apparatus, comprising a resin matrix and a recording layer (hereinafter referred to as a thermochromic layer) whose main component is an organic low-molecular substance dispersed in the resin matrix and whose transparency changes reversibly depending on temperature. An image forming apparatus characterized by being provided with a recording medium. 2. A step of thermally forming an image on the surface of the thermochromic layer of the recording medium according to claim 1, a step of uniformly charging the surface of the photoreceptor, and a step of uniformly exposing the photoreceptor to light from the recording body side to charge the electrostatic latent. An image forming method comprising the step of forming an image. 3. The image forming method according to claim 2, wherein when the copy original size is A4 (vertical) or less and the number of copies set is plural, a plurality of original images are formed on the recording medium according to claim 1.