JPH04253054A - Image forming device - Google Patents

Abstract

PURPOSE:To offer an image forming device which can form an image having no defect on an image receiving sheet. CONSTITUTION:The surface of a pressure roller 55a is heated by a high frequency power source 58, and the image receiving sheet 22 is in contact with the pressure roller 55a, to carry out preliminary heating. On the other hand, toner as a color developing agent 37 and a microcapsule sheet 44 are heated by thermal conduction, as well. Thus, the temp. of the toner as the toner 37 is risen, and it is softened. The temp. of the image receiving sheet is higher than that of the microcapsule sheet 44, so that the toner 37 is infiltrated into the image receiving sheet. After that, the microcapsule sheet 44 and the image receiving sheet are separated. The toner 37 is infiltrated into the image receiving sheet, so that the toner 37 does not stick to the microcapsule sheet 44, but all developers are stuck to the image receiving sheet. Thus, the image is formed on the image receiving sheet without having the defect.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image forming apparatus. Specifically, the present invention relates to an image forming apparatus using microcapsule paper coated with microcapsules containing a dye precursor.

0002

2. Description of the Related Art Conventionally, as an image forming apparatus, the following color copying apparatus using microcapsule paper as a photosensitive and pressure sensitive medium has been devised. In this device, a latent image corresponding to a document is first formed on microcapsule paper. Next, particulate color developer is applied to image receiving paper, which may be microcapsule paper or plain paper. Then, the microcapsule paper and the image receiving paper are overlapped. At this time, the color developer is located between the microcapsule paper and the image receiving paper. This superimposed microcapsule paper and
The image receiving paper is pressed by a pressure roller or the like. Then, when the microcapsule paper and the image receiving paper are separated,
An image is formed on the receiver paper. Further, in order to more strongly fix the image on the image receiving paper and to promote color development, the image receiving paper is heated by a heat fixing machine. In this way,
The image is fixed on the receiving paper. In this apparatus, the method for applying a color developer to microcapsule paper or image-receiving paper is as follows. First, a developer toner containing a color developer as a main component is supported on a developer carrier such as a roller. At this time, the developer toner is charged. Further, an electric field is formed between this color developer carrier and the microcapsule paper or the image receiving paper. The charged color developer toner receives an electrostatic force from this electric field and flies toward the microcapsule paper or the image receiving paper. As a result, a color developer is applied.

0003

However, in the image forming apparatus described above, defects have occurred in the images formed on the image receiving paper. That is, in a part of the image portion of the image receiving paper, the image was missing and the fabric of the image receiving paper was exposed. This defect is caused by the fact that when the microcapsule paper and receiver paper are separated after pressure development, all of the developed color developer toner and dye do not adhere to the receiver paper, but some of them are deposited on the microcapsule paper. It was due to adhesion.

To solve this problem, a method has been devised in which the image-receiving paper is heated before and after pressure development in order to preferentially penetrate the molten color developer into the image-receiving paper. However, in order to heat the image receiving paper before and after pressure development, it is necessary to provide a heating mechanism, which is expensive and requires a large space.

The present invention has been made to solve the above-mentioned problems, and its purpose is to
An object of the present invention is to provide an image forming apparatus capable of forming images without defects.

[0006]

[Means for Solving the Problems] In order to achieve this object, the image forming apparatus of the present invention includes an exposing means for forming a latent image on a photosensitive pressure sensitive medium, and an exposing means for forming a latent image on a photosensitive pressure sensitive medium or an image receiving paper. An image forming apparatus having a means for applying a colorant toner, a developing means for superimposing a photosensitive pressure-sensitive medium, a color developer toner, and an image receiving paper and applying pressure, and a heat fixing means for fixing the image on the image receiving paper. Therefore, during development, a preheating means for the developing means is provided for heating the overlapping photosensitive pressure sensitive medium, developer toner, and image receiving paper at a temperature lower than the fixing temperature in the heat fixing means. Features.

[0007] Furthermore, the preheating means is characterized by using a high frequency current.

[0008]

[Operation] In the image forming apparatus of the present invention having the above-mentioned structure, the image receiving paper is heated by preheating in the developing machine, and its temperature rises. Heat conduction also increases the temperature of the developer toner and the microcapsule paper. The color developer toner softens as the temperature rises. Here, since the temperature of the image receiving paper is higher than the temperature of the microcapsule paper, the developer toner penetrates into the inside of the image receiving paper. Thereafter, when the microcapsule paper and the image-receiving paper are separated, since the developer toner has permeated into the image-receiving paper, the developer toner does not adhere to the microcapsule paper. That is, an image with no defects is formed on the image receiving paper.

Furthermore, since this preheating mechanism is provided within the developing machine, it is inexpensive and requires no installation space.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention will be described below with reference to the drawings. FIG. 1 shows an image forming apparatus 40 of a type that applies mixed developer toner to image receiving paper. Inside the casing 46 of the image forming apparatus 40, an exposure unit 41, a color developer application unit 1, a pressure development unit 47, and a heat fixing unit 49 are provided.

This exposure unit 41 includes a halogen lamp 5.
0, a color separation filter 51, and a document table 52. Here, the color separation filter 51 is provided below the halogen lamp 50 and is configured to rotate in accordance with the three primary colors. Further, below the color separation filter 51, a document table 52 for supporting a document is arranged. The color developer application unit 1 is provided for the purpose of applying color developer toner to the image receiving paper on which an image will finally be formed. This color developer application unit 1 includes a support roller 3
1, a conveyor belt 24, an electrode roller 21, and a power source E. The carrying roller 31 is provided to carry and convey the stored developer toner 37. Since the conveyance belt 24 is wrapped around the electrode roller 21 , the image receiving paper 22 is conveyed by the electrode roller 21 and the conveyance belt 24 . The electrode roller 21 is made of metal and is connected to a power source E. Further, the supporting roller 31 is grounded. Therefore, an electric field is generated in the space between the support roller 31 and the electrode roller 21, that is, in the transfer area 34. The power supply E is
Specifically, it is configured to generate a voltage of +1 kV.

The pressure developing unit 47 is provided to pressurize the microcapsule paper and the image receiving paper, and is composed of a pair of pressure rollers 55a and 55b. A high frequency power source 58 is connected to the pressure roller 55a.

The operation of this device will be explained.

First, the image receiving paper 22 is placed in the image receiving paper cassette 13.
is taken out by the feed roller 14 from the upper opening of the paper. Next, the image receiving paper 22 is inserted into the developer coating unit 1 through the insertion opening 11 . Electrode roller 21
The conveyance roller 23 rotates, and the conveyance belt 24 is driven. The image receiving paper 22 is conveyed to a transfer area 34 by a conveyor belt 24 . On the other hand, mixed color developer toner 37
is conveyed to the transfer area 34 by the carrying roller 31. As described above, an electric field is generated in the transfer region 34. In the transfer area 34, the developer toner 37 carried on the carrying roller 31 is subjected to electrostatic force by the electric field. In this embodiment, the developer toner is negatively charged. For this reason, developer toner is
It receives electrostatic attraction from the electrode roller 21. In this manner, the developer toner is applied to the receiver paper. The image receiving paper 22 coated with the developer toner is delivered to the outside of the developer coating unit 1 through the discharge port 12 . Furthermore, the receiving paper 22
is conveyed to the pressure developing unit 47 according to the guide roller 54.

On the other hand, the microcapsule paper 44 is configured to run between the paper feed roll 42 and the take-up roll 43. First, the microcapsule paper is unwound from the paper feed roll 42 and sent to the exposure unit 41. Next, the microcapsule paper 44 is conveyed to the lower part of the document table 52 according to the operation of the guide roller 53. Next, the halogen lamp 50 is turned on. The light from the halogen lamp passes through the color separation filter 51 and the original. The light that has passed through the original reaches the microcapsule paper located at the bottom of the original table. Microcapsule paper capsules have the property of curing in response to light. Therefore, a latent image corresponding to the original document 45 is formed on the microcapsule paper 44. The microcapsule paper 44 on which the latent image has been formed is conveyed by a guide roller 53 toward a pressure developing unit 47 . Inside the pressure developing unit 47, the microcapsule paper 44 and the image receiving paper 22 are superimposed. At this time, the surface of the microcapsule paper 44 on which the latent image was formed,
The developer coated surfaces of the image receiving paper 22 are in contact with each other. Next, the pair of pressure rollers 55a and 55b rotate, and the microcapsule paper 44 and the image receiving paper 22 are pressurized. As a result, uncured capsules are destroyed. In the destroyed capsule, the dye inside flows out. This dye reacts with the mixed developer toner on the image receiving paper to develop color.

At this time, the surface of the pressure roller 55a is generating heat due to the high frequency power source 58, and since the image receiving paper 22 is in contact with the pressure roller 55a, it is preheated. Further, the color developer toner and the microcapsule paper 44 are also heated by thermal conduction.

In the microcapsule paper 44, microcapsules are coated on a base sheet with a binder. Therefore, the temperature of this preheating must be set lower than the melting temperature of the binder. On the other hand, if the preheating temperature is too low, it will not be effective. Specifically, the heat fixing temperature of the color developer in this example is 140 to 1
80°C, and the melting temperature of the binder is about 120°C, so the temperature on the surface of the heating roller is 40-10°C.
The temperature is set to 0°C. In this way, the temperature of the developer toner increases and softens. Since the temperature of the image receiving paper is higher than the temperature of the microcapsule paper, the developer toner penetrates into the inside of the image receiving paper. After this, the microcapsule paper and the receiver paper are separated. As described above, since the developer toner has permeated the image receiving paper, the developer toner does not adhere to the microcapsule paper, and all the developer is attached to the image receiving paper. In this way, a defect-free image is formed on the receiving paper.

After pressure development, the receiver paper 22 and the microcapsule paper 44 are separated. The image receiving paper 22 is conveyed to the lower part of the thermal fixing unit 49 by a guide roller 56 . Since the image receiving paper is heated by the thermal fixing unit 49, the image is fixed on the image receiving paper 22.

The image receiving paper 22 on which the image has been thermally fixed is outputted to the outside of the image forming apparatus 40 according to the guide roller 57. On the other hand, the microcapsule paper 44 is wound up by a winding roll 43.

[0020]

[Effect of the invention] As is clear from the detailed description above,
According to the present invention, it is possible to provide an image forming apparatus that can form a defect-free image on image receiving paper.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment embodying the present invention.

[Explanation of symbols]

37 Color developer toner 22 Image receiving paper 44 Microcapsule paper 47 Pressure development unit 55a Pressure roller 58 High frequency power supply

Claims (2)

[Claims] 1. An exposure means for forming a latent image on a photosensitive pressure-sensitive medium; a means for applying developer toner to the photosensitive pressure-sensitive medium or image-receiving paper; and a photosensitive pressure-sensitive medium, developer toner, and image-receiving paper. In an image forming apparatus having a developing means for overlapping and applying pressure, and a heat fixing means for fixing the image to the image receiving paper, during development, the overlapping photosensitive pressure sensitive medium, developer toner and image receiving paper An image forming apparatus comprising a preheating means for a developing means for heating the image at a temperature lower than the fixing temperature in the thermal fixing means. 2. The image forming apparatus according to claim 1, wherein the preheating means is a high frequency current.