JPH05281694A - Image forming device - Google Patents

Abstract

PURPOSE:To speed up image formation and to reduce electric power consumption by using a low-sensitivity photopolymerizable microcapsule toner by impressing at least alternating magnetic fields or alternating electric fields to the photosensitive microcapsule toner at the time of subjecting the microcapsule toner to curing by exposing in accordance with image formation. CONSTITUTION:An electromagnetic sensitizing device 49 is constituted of at least >=1 pieces of coils or a pair of flat plate electrodes facing each other by holding an intermediate belt 38 deposited with the microcapsule toner 1 and generates at least the alternating magnetic fields or alternating electric fields. The particulates in the toner 1 are vibrated by such alternating magnetic fields and the liquid component in the toner is heated and stirred by such vibration, by which the molecular vibration in the liquid component is activated and simultaneously the collision frequencies of the polymerizable compd. and a photopolymn. initiator are increased. Since the speed of the polymn. curing reaction is thereby increased, the curing speed is made exceedingly higher than in the exposing method where the electromagnetic sensitizing device 49 is not used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive microcapsule toner, and more specifically, a microcapsule containing at least a coloring material such as a leuco dye, a colored dye or a pigment as an inclusion, and having a mechanical strength which changes in response to light. The present invention relates to an image forming apparatus such as a copying machine or a printer that uses capsule toner.

[0002]

2. Description of the Related Art Conventionally, a photosensitive medium coated with a microcapsule toner containing a dye precursor and a photocurable substance is exposed based on image information, and the microcapsule is cured to chemically expose the photosensitive medium to a chemical latent image. An image is formed, and then a developing agent that reacts with the dye precursor to develop a color is pre-coated with the image-receiving paper and the photosensitive medium is superposed and pressed to develop a chemical latent image by pressure. There is an image forming apparatus of a type that fixes an image on an image receiving paper.

As a kind of photo-curing, there is a method of obtaining a chemical latent image by photo-polymerizing and curing the microcapsules by irradiating image light with a photo-polymerization initiator and a polymerizable compound. For example, JP-A-57-179836. , JP-A-62-150238. Further, a method of forming a latent image nucleus on the photosensitive silver halide by irradiating image light with a photosensitive silver halide, a reducing agent and a polymerizable compound, and then thermally polymerizing and curing the latent image nucleus to obtain a chemical latent image. And is disclosed in, for example, JP-A-61-278849 and JP-A-62-232652.

As a different example of an image forming apparatus using the above-mentioned photosensitive medium, the present applicants have a photosensitive medium on which the above-mentioned chemical latent image is formed and an image-receiving paper which is plain paper, with a developer layer in between. We have proposed a device that forms an image on plain paper by stacking and pressing. Further, an image forming apparatus using a photosensitive medium carrying microcapsules containing a colored dye instead of the above dye precursor is disclosed in JP-A-62-232652.
It is disclosed in the publication.

The photosensitive medium is collected after use and discarded in a lump, or is cut and discarded every time an image is formed. As a result, the support, which is not necessary for forming an image, which is a plastic film, is consumed, so that the cost of consumables becomes high and the image forming cost becomes high.

In order to solve the above-mentioned problems, the present applicants made a photosensitive microcapsule into a toner, and applied it on a support by a known image forming process such as electrophotography,
An image forming apparatus having a structure in which only necessary microcapsule toner is consumed is disclosed in Japanese Patent Application No. 3-124919.

In the above image forming apparatus, image formation is performed as follows.

First, triboelectrically charged photosensitive microcapsule toner is applied onto a support by flying by using a direct current electric field, and when this is exposed to image light, the microcapsule toner is photopolymerized according to image information. Cured,
Dyeing of inclusions by applying pressure on the image receiving paper
The pigment is transferred to the receiving paper side (this process is pressure development,
The remaining capsule wall and the microcapsule toner that has hardened and did not contribute to color development remain on the support and are removed by a cleaner or the like. Thereby,
The desired image is formed on the image receiving paper.

[0009]

However, in the image forming apparatus disclosed in the above-mentioned Japanese Patent Application No. 3-124919, or in, for example, JP-A-57-1798.
In the image forming apparatus using photopolymerization disclosed in Japanese Patent Laid-Open No. 36-150230, No. 36, the exposure sensitivity is low and very high exposure energy is required, resulting in large power consumption of the entire apparatus. Further, generally, it takes an exposure time of 10 seconds or more to obtain a color image of A4 size, which causes a slowdown of image formation.

On the other hand, for example, Japanese Patent Laid-Open No. 61-278.
In an image forming apparatus using microcapsules containing high-sensitivity photosensitive silver halide as disclosed in JP-A No. 849 and JP-A-62-232652, after the microcapsules are exposed, Since heat development must be carried out, and the polymerization and curing speed during this heat development is slow, it caused a slowdown of image formation rather than a high sensitivity, and at the same time, the exposure means and the pressure development means were used. A heating and developing means must be provided between them, which causes increase in power consumption and complication of the apparatus.

The present invention has been made in order to solve the above-mentioned problems, and uses a photopolymerizable microcapsule toner, which has conventionally been low in sensitivity, realizes a high image forming speed and consumes less power. An object of the present invention is to provide an image forming apparatus capable of reducing the above.

[0012]

To achieve this object, an image forming apparatus of the present invention contains at least a coloring material such as a leuco dye, a colored dye or a pigment, a polymerizable substance, and a photopolymerization initiator. A photosensitive microcapsule toner composed of an inclusion and a wall member containing a resin such as a polymer as a main component is applied on a support, and the support is exposed based on image information. An electromagnetic sensitizing means for applying an alternating magnetic field or an alternating electric field to the photosensitive microcapsule toner is carried out.

[0013]

In the image forming apparatus of the present invention having the above-mentioned structure, the electromagnetic sensitizing means, when the photosensitive microcapsule toner is exposed and cured based on image information, at least an alternating magnetic field is applied to the photosensitive microcapsule toner. Alternatively, an alternating electric field is applied.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view of a constitution showing an embodiment of an image forming apparatus embodying the present invention, and FIG. 2 is a sectional view of a microcapsule toner.

The microcapsule toner 1 used in the image forming apparatus 10 of the embodiment is composed of a wall material portion and a liquid component contained therein, and the liquid component is light that cures in response to at least a predetermined wavelength. It contains a curable substance and a pigment that is a coloring material. Further, the liquid component contains fine particles 2 which can freely move in the liquid component by applying an electric field or a magnetic field. As the fine particles 2, magnetic powder such as magnetite having a diameter of about 1 μm can be used,
When the liquid component is water-soluble, an ionic substance such as sodium chloride or potassium chloride may be dissolved in the liquid component, and the pigment is dispersed in the liquid component to form a colloidal form. Is charged positively or negatively,
The action of the fine particles 2 may be caused in the pigment itself.

Examples of the photo-curable substance include polymerizable compounds such as N-vinyl-2-pyrrolidone, bisphenol A diacrylate and methacrylate, tripropylene glycol diacrylate and methacrylate, polyethylene glycol diacrylate and methacrylate, penta. Examples include erythritol triacrylate and methacrylate, dipentaerythritol hexaacrylate and methacrylate, trimethylolpropane triacrylate and methacrylate, oligoester acrylate and methacrylate, and the like. In addition, these polymerizable compounds may be used alone or as a mixture of two or more kinds. Usually, these polymerizable compounds and a photopolymerization initiator are used in combination.

The photopolymerization initiator is one which is sensitive to light and initiates the polymerization of the resin. For example, benzoyl alkyl ethers such as benzophenone and benzoyl isopropyl ether, Michler's ketone, metal arene compounds,
2,4-diethylthioxanthone and the like can be mentioned.

The image forming apparatus 10 of the embodiment is an image forming apparatus 1 described in the following embodiment according to an image information signal.
A control unit 12 is provided to control all movable parts and light emitting parts (hereinafter abbreviated as movable parts) in 0 so as to operate properly for image formation.

The control unit 12 sends a command to a driver, a switch or the like connected to the movable part or the like while monitoring the operating conditions of the movable part or the like with a sensor or the like to control the movable part or the like. is doing.

A document supporting glass 16 is attached to the upper surface of a casing 14 of the image forming apparatus 10. The document is sandwiched between the document supporting glass 16 and the document retainer 18 and held so that the image surface faces downward.

Below the document supporting glass 16, a light source lamp 20 for illuminating the document, a solid-state image pickup device 22 for reading the reflected light from the document, and reflected light from the document on the solid-state image pickup device. An optical system 24 for forming an image and an arithmetic element 26 for converting an electric signal generated by the image light being formed on the solid-state image sensor into an image information signal.
A scanner unit 28 having a and is provided.

When a copy start button (not shown) is pressed, the scanner section 28 moves in the direction of arrow 30 by a motor (not shown) or the like in accordance with an instruction from the control unit 12 while moving the original document. The reading operation is performed, and the read image information signal is transferred to the control unit 12.

The microcapsule toner 1 is stored in the toner case 32 while being shielded from light. The supply roller 34 has a cylindrical shape with a diameter of about 10 mm and is made of urethane sponge. The charging blade 35 is
The carrying roller 36 is a nylon resin plate material having a thickness of about 1 to 2 mm, and a metal core rod having a diameter of about 25 mm is coated with a nylon resin having a thickness of about 200 to 1000 μm. The metal core rod of the carrying roller 36 is grounded.

The supply roller 34 rotates counterclockwise in FIG. 1 in response to a command from the control unit 12, and the carrier roller 36 also rotates in the direction of arrow 37.

By rotating the supply roller 34, the microcapsule toner 1 is pulled out from the toner case 32, and at this time, the charging blade 35 and the microcapsule toner 1 rub, and the microcapsule toner 1 is charged.

The intermediate belt 38 is made of a silicone sponge having excellent releasability and is wound around a metal intermediate belt driving roller 40 and a high pressure roller 42, and the intermediate belt controlled by the control unit 12 is used. It is driven in the direction of arrow 44 by the drive roller 40. The high-pressure roller 42 has a polarity opposite to the charging polarity of the microcapsule toner 1 and is 1 kV in order to fly the triboelectrically charged microcapsule toner 1 from the carrying roller 36 and coat it on the intermediate belt 38. Apply a high DC voltage.

The supply roller 34 and the carrying roller 36 are always in friction with each other, and due to this friction, the charging blade 35 is placed on the surface of the carrying roller 36 charged to the opposite polarity to the microcapsule toner 1. The microcapsule toner 1 frictionally charged by is electrostatically adsorbed and carried.

The microcapsule toner 1 carried on the carrying roller 36 is acted upon by an electric field generated between the core bar of the carrying roller 36 and the high-pressure roller 42, which are grounded, and thereby the intermediate belt. 38 is electrostatically applied.

The microcapsule toner 1 electrostatically applied on the intermediate belt 38 is made of metal and has a thickness of about 5 mm.
The coating thickness is made uniform by the layer regulation blade 46 of 0 μm. The layer-regulating blade 46 is slightly bent, and is pressed against the intermediate belt 38 with a weak pressure due to the elasticity of the bending, so that the coating thickness of the microcapsule toner 1 is not broken and the coating thickness is uneven. However, since a DC voltage having the same polarity as that of the microcapsule toner 1 is applied,
Can make the coating thickness uniform without adhering to the layer regulating blade 46.

The microcapsule toner 1 whose coating thickness is made uniform by the layer regulating blade 46 is exposed by the exposure source 48 controlled by the control unit 12 according to the image information read by the scanner section 28. At the same time, at least an alternating electric field or an alternating magnetic field is applied by the electromagnetic sensitizer 49 controlled by the control unit 12.

The electromagnetic sensitizer 49 is composed of at least one coil or a pair of opposed flat plate electrodes sandwiching the intermediate belt 38 carrying the microcapsule toner 1 and at least an alternating electric field or an alternating electric field. Generates a magnetic field. The alternating electromagnetic field causes the fine particles 2 to vibrate, and the vibration causes the liquid component to heat,
At the same time when the liquid components are stirred and the molecular vibrations in the liquid component become active, the frequency of collision between the polymerizable compound and the photopolymerization initiator increases and the speed of the polymerization curing reaction increases, so that the electromagnetic sensitizer 49 is used. The curing sensitivity is dramatically increased as compared with the conventional exposure method which is not used.

The exposure source 48 and the electromagnetic sensitizer 49.
The microcapsule toner 1 in which the liquid component is selectively photopolymerized and hardened according to the image information is pressed by the pressure transfer roller 52 rotating in the direction of the arrow 50, and the microcapsule which is not photopolymerized and hardened is pressed. Only the capsule toner 1 is destroyed, and the liquid component containing the coloring material is carried on the pressure transfer roller 52.

The debris of the microcapsule toner 1 remaining on the intermediate belt 38 after pressing and the microcapsule toner 1 photopolymerized and cured are cleaned by the cleaning brush 5.
It is removed by being slid by 4 and is discarded in the dust box 56.

The image receiving paper 60 stored in the image receiving paper cassette 58 is fed out by the paper feeding roller 62, and the arrow 68 is drawn by the paper guide 64 and the paper guide roller 66.
Is guided in the gap between the nip roller 70 rotating in the direction of and the compression transfer roller 52, is nipped by the nip roller 70 and the compression transfer roller 52, and is pressed,
The liquid component containing the color material carried on the pressure transfer roller 52 is transferred onto the image receiving paper 60 to form an image on the image receiving paper 60.

The image receiving paper 60 having the formed image.
Is guided by the paper discharge roller 72 and discharged to the exit tray 74.

The present invention is not limited to the embodiments described in detail above, and various changes can be made without departing from the spirit of the invention.

For example, in the above embodiment, static electricity was used as the application means of the microcapsule toner.
A mechanical / chemical action other than static electricity, such as magnetism or physical adsorption, may be used.

[0039]

As is apparent from the above description, according to the image forming apparatus of the present invention, the electromagnetic sensitizer activates the molecular vibration of the liquid component in the microcapsule toner by the alternating electric field or magnetic field. By increasing the frequency of collision between the polymerizable compound and the photopolymerization initiator contained in the liquid component, and increasing the photocuring reaction rate, by using a photopolymerizable microcapsule toner having a conventionally low sensitivity,
It is possible to perform image formation at high speed and reduce power consumption.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an image forming apparatus of the present invention.

FIG. 2 is an enlarged cross-sectional view of a microcapsule toner used in the image forming apparatus.

[Explanation of symbols]

 1 Microcapsule Toner 2 Fine Particles 36 Supporting Roller 48 Exposure Source 49 Electromagnetic Sensitizer

Claims (1)

[Claims] 1. A structure comprising at least a coloring material such as a leuco dye, a colored dye or a pigment, an enclosure containing a polymerizable substance and a photopolymerization initiator, and a wall member containing a polymer such as a polymer as a main component. In an image forming apparatus that applies a photosensitive microcapsule toner onto a support and exposes it based on image information, when performing the exposure, an alternating magnetic field, or Is an image forming apparatus comprising an electromagnetic sensitizing means for applying an alternating electric field.