JPS62162552A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent a heating element from becoming short lived and enable a sharp image to be formed for a long time by providing a dye settlement preventing member on the surface of a dye heating element stored in a container. CONSTITUTION:When an image is formed, a sublimating or evaporating dye 4 is heated and gasified by a heater 3 and then is injected from a nozzle 5. The injected dye does almost not settle by virtue of a dye settlement preventing member 2 and instead settles on the back of a gas permeable film 8. The film 11 is heated in accordance with an image signal transmitted from a thermal head and the part corresponding to the thermal head of the film 11 is gasified to allow the gas to penetrate through the gas permeable film 8 for formation of an image on a receptor paper 9. In this mean-time, the thermal head moves with a casing 7 and a container 1 to form a single line of image on the receptor paper over a platen roll 10. If the formation is terminated, the platen roll rotates to move the receptor paper by a single line, while the thermal head returns to its original position. Thus this process is repeated to end image formation.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a thermal transfer image forming apparatus such as a copying machine, printer, facsimile, etc., which does not require a base film.

Prior Art The applicant of this application proposed the following as shown in Japanese Patent Application No. 60-82007 as an alternative to the conventional image forming apparatus. This image forming apparatus sublimates or vaporizes a sublimable or vaporizable dye contained in a container using a heating member installed inside or outside the container, and forms a thin film of this on the back surface of a gas permeable membrane. The n-thermal element adjacent to this gas permeable membrane is heated in accordance with the image signal,
An image-forming dye gas is generated from the thin dye film and transmitted through the gas-permeable membrane to form an image on a receiving paper adjacent to the surface of the gas-permeable membrane. The drawbacks of conventional image forming apparatuses can be eliminated.

However, in such existing image forming apparatuses, the dye not only adheres to the gas permeable membrane, but also adheres to the surface of the heating element, which not only shortens the life of the heating element, but also Non-sublimable materials added to improve dye adhesion, sublimation or vaporization efficiency, such as metals, silica,
Due to the adhesion of glass powder, fibers, mesh, etc., heat transfer from the heating element directly to the dye that contributes to image formation is inhibited by the dye adhering to the heating element, and as the amount of N attached increases, image formation is hindered. This caused the inconvenience of not being able to do it correctly.

Purpose This invention solves the inconveniences of the previously proposed image forming apparatuses as described above, prevents dye from adhering to the surface of the heating element, prolongs its life, and improves the efficiency of the dye that contributes to image formation. It is an object of the present invention to provide an image forming apparatus that maintains good heat transfer and can form images accurately for a long time.

Structure In order to achieve the above-mentioned object, the present invention is characterized in that a sublimable or vaporizable dye contained in a container is heated or a dye adhesion prevention member is provided on the surface of a heating element. .

The present invention will be described with reference to embodiments shown in the drawings.

FIG. 1 shows a first embodiment of the invention. 1 is a container which has a built-in heater 3 and is filled with a sublimable or vaporizable dye 4. As the heater 3, a known type such as a nichrome wire heater can be used, and electricity is supplied through a lead wire 3'. The sublimable or vaporizable dye 4 is selected from among known dyes, such as dispersed monoazo dyes, dispersed anthraquinone dyes, cationic dyes, nitro dyes, quinophthalone dyes, etc.
A material that exhibits sublimation or vaporizability at temperatures between .degree. C. and 300.degree. C. is used.

Moreover, these dyes may be used alone.

For the purpose of increasing sublimation or vaporization efficiency, non-sublimable materials such as metal, silica, glass powder, fibers, mesh, etc. may be added.

The container 1 is further provided with an injection nozzle 5 from which the gasified dye is injected when the dye is heated. In this embodiment, the nozzle 5 has a width α2vss and a length λ5■.

A container 7 containing a thermal head 6 is attached to the container 1 in a separable or non-separable manner. The thermal head 6 is provided with a dye adhesion prevention member 2, which is made of fluorocarbon resin (for example, polytetrafluoroethylene), polyamide, silicone resin, etc., and has a film thickness of 3 μm to 30 μm. In this example, a polytetrafluoroethylene film with a thickness of 3 μm is formed.

A gas permeable membrane 8 is placed on the national polity 7, and the gasified dye adheres thereto. 9 is a receiving paper, and 10 is a platen roll.

When forming an image using the above-mentioned method, the dye 4 is heated by the heater 3.

This dye 4 is gasified and injected from the nozzle 5. This injected dye is prevented from adhering to the thermal head 6 by the dye adhesion prevention member 2 (the gas permeable film 8
A thin film 11 is formed by adhering to the back surface of the film. When the thermal head 6 is heated in accordance with the image signal sent thereto, the corresponding portion of the thin film 11 is gasified and transmitted through the permeable film 8, and an image is formed on the receiving paper 9.

During this time, the thermal head 6 moves together with the casing 7 and the container l to form one line of image on the receiving paper 9 on the platen roll Mio, and when that is finished, the platen roll 10 rotates to form the receiving paper 9 on the receiving paper 9 for one line. During this time, the thermal head 6 returns to its original position, and this process is repeated to complete the desired image formation.

A second embodiment of the present invention is shown in FIG. 2, and most of it has the same structure as the first embodiment, so
By assigning the same reference numerals to the parts as in the first embodiment, the explanation will be omitted, and the different parts will be mainly explained.

In this embodiment, a blower 12 for replenishing the dye is installed in the injection nozzle 5, and the dye adhesion prevention member 2' is different from the above-described one in that it covers the entire surface of the thermal head 6. There is.

As shown in FIG. 3, the blower 12 is used for image forming processes A and C.
is OFF, and is OFF during the return process B of the thermal head.
N, and set it to 5 to inject dye only in return process B (.

Effects This invention is as described above, and since the dye adhesion prevention member is provided on the surface of the heating element that heats the dye housed in the container, it prevents the dye from adhering to the surface of the heating element and prevents the dye from adhering to the surface of the heating element. It has the following five effects: it prevents the heating element from shortening due to heat transfer, maintains good heat transfer to the dye, and forms clear images over a long period of time.

[Brief explanation of drawings]

FIG. 1 is a cutaway plan view of essential parts of a first embodiment of the present invention, and a second embodiment of the present invention is shown in FIG.
The drawings are similar to the N1 drawing of the second embodiment of this invention, and the third
The figure is a table showing the action cycle of the same as above.

Claims (1)

[Claims] 1. Sublimating or vaporizing the sublimable or vaporizable dye contained in the container using a heating member installed inside or outside the container to form a thin film of this on the back surface of the gas permeable membrane;
A heating element adjacent to the gas permeable membrane is heated in response to an image signal to generate an image-like dye gas from the thin dye film to permeate the gas permeable membrane and onto the surface of the gas permeable membrane. An image forming apparatus that forms an image on a receiving sheet in close proximity to each other, wherein the image forming apparatus is characterized in that a dye adhesion prevention member is provided on the surface of the heating element.