JPH0667398A - Image forming device - Google Patents

Abstract

PURPOSE:To easily reduce the size of a device adopting a noncontact developing method and to easily prevent uneven color development at the time of development as well as image stain and noise. CONSTITUTION:A microencapsulated toner 1 contg. a magnetic substance in the wall material is distorted by a magnetic filed and destructed in a noncontact state in a magnetic developing device 50 to release the contents including a coloring material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly to a microcapsule which contains at least a coloring material such as a leuco dye, a colored dye or a pigment as an encapsulation, and whose mechanical strength changes in response to light. It relates to the copying machines and printers used.

[0002]

2. Description of the Related Art Conventionally, a photosensitive medium coated with microcapsules containing a dye precursor and a photocurable substance is exposed on the basis of image information, and the microcapsules are cured to form a chemical latent image on the photosensitive medium. Then, the image receiving paper on which the color developing agent which reacts with the dye precursor and develops color in advance and the photosensitive medium are superposed and pressed, and the chemical latent image is developed by pressure to form an image receiving paper. An image forming apparatus of a type that fixes an image is known.

As a type of photo-curing, there is a method of obtaining a chemical latent image by photo-polymerizing and curing the microcapsules by using a photo-polymerization initiator and a polymerizable compound and irradiating light according to image information. It is disclosed in Japanese Laid-Open Patent Publication No. 63-316038. The progress of the photoreaction is determined by an initiator that generates a reactive species such as a radical upon irradiation with light, and a wavelength that is added for advancing the photoreaction by absorbing light of a predetermined wavelength and transmitting the energy to the initiator. It is carried by a sensitizer.

Further, as a method for improving the sensitivity of photopolymerization and curing by improving the above-mentioned constitution, a photosensitive silver halide, a reducing agent and a polymerizable compound are used, and the photosensitive halogen is irradiated by irradiation of light according to image information. There is a method in which a latent image nucleus is formed on silver halide and then heat-polymerized and cured by heating to obtain a chemical latent image, for example, JP-A-61-278849 and JP-A-62-1326.
No. 52, etc.

In any of the above image forming apparatuses,
Image formation was possible only on a special paper having a developer layer on the surface.

As a different example of the image forming apparatus using the above-mentioned photosensitive medium, the present applicant has overlaid the photosensitive medium on which the above-mentioned chemical latent image is formed and the image receiving paper which is plain paper with the developer layer in the middle. We have devised a device that pressurizes together and forms an image on plain paper. Further, an image forming apparatus using a photosensitive medium carrying microcapsules containing a colored dye instead of the dye precursor is disclosed in JP-A-62-232652.

However, in any of the above-mentioned image forming apparatuses, the photosensitive medium used is a plastic film such as PET as a support, and a binder such as PVA is dissolved in an appropriate solvent on the surface of the support. A photosensitive medium was prepared by coating a microcapsule slurry in which photosensitive microcapsules were dispersed in a binder aqueous solution, and drying this to fix the photosensitive microcapsules on a support.

This photosensitive medium is collected after use and discarded in a lump, or only the used portion is cut and discarded each time an image is formed. Therefore, the support, which is not necessary for forming an image, which is a plastic film, is consumed, resulting in a high cost of consumables and a high image forming cost.

In order to solve the above-mentioned problems, the applicant of the present invention converts a photosensitive microcapsule into a toner, and coats it on a support by an image forming process such as a well-known electrophotographic method. An image forming apparatus having such a structure that only one 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 using a DC electric field.

Next, the microcapsule toner coated on the support is irradiated with light according to the image information to photopolymerize and cure the microcapsule toner according to the image information.

Then, the dye / pigment of the inclusion is transferred to the image receiving paper or the transfer medium side by superposing the image receiving paper or the transfer medium on which the inclusion is temporarily held and applying pressure with a pressure roller or the like. The process is referred to as pressure development, which is abbreviated as genre), and the microcapsule toner that has not contributed to the color development due to the capsule wall and the microcapsule toner remains on the support, and these are removed later with a cleaner or the like.

When the above-mentioned transfer medium is used, the image-receiving papers are subsequently stacked, and the inclusions carried on this transfer medium are re-transferred to the image-receiving paper side by the action of pressure or heating. As described above, the desired image is formed on the image receiving paper.

[0015]

However, the conventional image forming apparatus as described above has the following problems.

The first problem is that when performing pressure development, a very high pressure is required to press the hardened capsule together with the hardened capsule in order to destroy the uncured capsule, resulting in uneven coloring. It is necessary to apply a uniform pressure over the entire surface of the paper so that it does not occur, so a very large and complicated pressurizing device is required, which causes an increase in size and cost of the image forming apparatus. This is a particularly serious problem in the case of forming an image on a large paper size of B4 or more.

The second problem is that, during pressure development, inclusions such as coloring materials and unnecessary substances such as hardened capsules and broken capsule walls adhere to the pressure device side, which complicates cleaning and maintenance. It is to end up. Further, in the case of an image forming system in which an inclusion is transferred to one member (hereinafter, referred to as a pressure transfer member) of the pressurizing device and further transferred to an image receiving paper, an unnecessary material is added to the pressure transfer member. Since the unwanted substances and the inclusions cannot be separated well because of the adherence of the capsules, the broken capsule wall that should remain on the support and the microcapsule toner that has hardened and did not contribute to color development There arises a problem that an unnecessary object is erroneously transferred to the transfer medium or the image receiving paper side, causing stains or noise on the formed image.

With respect to the second problem, a microcapsule toner having a magnetic material contained in a wall member or in an inclusion is used, and the microcapsule toner is constrained to the support side by a magnetic force at the time of compression, so that a pressing device is used. Japanese Patent Application No. 3-18786 relating to the present applicant describes a method of preventing the transfer of the unwanted matter to the side.
Attempts have been made to solve the problems by the image forming apparatus disclosed in Japanese Patent No. 3 specification and drawings, but in order to destroy the microcapsule toner, at least 20 kgf / cm ² or more, usually about 100
Since a very large pressing force of kgf / cm ² is required, unnecessary substances will adhere to the pressurizing device side due to this large pressing force, and the effectiveness of using the magnetic substance-containing capsule will be improved. I couldn't show it to the full.

These problems occur because the pressure development is performed by the direct contact of the pressure member, and the non-contact development method which can be carried out with a simple structure for both the capsule and the apparatus. Development was awaited.

The present invention has been made to solve the above-mentioned problems, and uses a non-contact developing method to downsize the apparatus, prevent uneven coloring during development, and include coloring materials. An object of the present invention is to provide an image forming apparatus capable of improving defective separation between an object and an unnecessary object such as a hardened capsule or a broken capsule wall and preventing image stain and noise with a simple configuration.

[0021]

In order to achieve this object, an image forming apparatus of the present invention comprises an inclusion material containing at least a coloring material such as a leuco dye, a colored dye or a pigment, and a polymerizable substance, a polymer, etc. By leaking the inclusions from a microcapsule toner composed of a resin or inorganic substance as a main component and a wall member containing a magnetic fine powder, and transferring the leaked inclusions onto an image receiving material. An image forming apparatus for forming an image is characterized by including magnetic force developing means using magnetic force as means for leaking the inclusions.

[0022]

In the image forming apparatus of the present invention having the above-mentioned structure, the magnetic force developing means applies a magnetic field to the microcapsule toner and deforms the wall member by the magnetic force acting on the magnetic fine powder to distort it. By destroying the microcapsule toner, the inclusions containing the coloring material and the like are leaked, and the leaked inclusions are transferred onto the image receiving material to form an image on the image receiving material.

[0023]

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 diagram of a configuration showing an embodiment of an image forming apparatus embodying the present invention.

As the microcapsule toner 1 used in the image forming apparatus 10 of the embodiment, the microcapsules disclosed in the specification of Japanese Patent Application No. 3-187863 related to the present applicant and the drawings can be used. The outline will be described below.

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 which is an encapsulation thereof, and in the wall material portion, fine powder of magnetic material such as magnetite is contained. It is compounded. Further, as the liquid component, at least a photocurable substance that cures in response to a predetermined wavelength and a pigment that is a coloring material are included.

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 thereof include erythritol triacrylate and methacrylate, dipentaerythritol hexaacrylate and methacrylate, trimethylolpropane triacrylate and methacrylate, oligoester acrylate and methacrylate and the like. Further, 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.

As the material for forming the wall material, gelatin, gum arabic, starch, sodium alginate, polyvinyl alcohol, polyethylene, polyamide, polyester, polyurethane, polyurea, polyurethane,
Polystyrene, nitrocellulose, ethyl cellulose,
Methyl cellulose, melamine-formaldehyde resin,
A urea-formaldehyde resin or the like is used, but a material that allows sufficient light transmission is more preferable.

The microcapsule toner 1 having the above structure is
It can be produced by a method already known in the art. For example, US Pat. No. 2,800
No. 457, No. 2800458, etc., a method for phase separation from an aqueous solution, Japanese Patent Publication No. 38-1974,
Japanese Patent Publication No. 42-446, Japanese Patent Publication No. 42-771, etc., interfacial polymerization method, Japanese Patent Publication No. 36-9168,
In-situ method by polymerization of monomers as disclosed in JP-A-51-9079, British Patent No. 952807.
No. 965074 and the melting dispersion cooling method and the like, but not limited thereto.

Further, according to the above-mentioned manufacturing method, the particle size of the microcapsule toner 1 having the above-mentioned structure is several to 100 μm.
It can be arbitrarily adjusted within the range of m.

The image forming apparatus 10 of the embodiment is the image forming apparatus 1 described in the following embodiment according to the 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 controls the movable part and the like by sending a command to a driver, a switch and the like connected to the movable part and the like while monitoring the operating conditions of the movable part and the like with a sensor and 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 support 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 a reflected light from the document on the solid-state image pickup device. A scanner unit 28 having an optical system 24 for forming an image and an arithmetic element 26 for converting an electric signal generated by forming an image of light according to image information on the solid-state image pickup device into an image information signal. Is equipped with.

When a copy start button (not shown) is pressed, the scanner unit 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 to move 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 a plate material made of nylon resin having a thickness of about 1 to 2 mm, and the carrying roller 36 is a metal core rod having a diameter of about 25 mm coated with 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 in the counterclockwise direction in FIG. 1 in response to a command from the control unit 12, and the carrying 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 silicon sponge having excellent releasability. The intermediate belt 38 is wound around a metallic intermediate belt drive roller 40 and a high pressure roller 42, and is controlled by the control unit 12. Drive roller 4
It is driven in the direction of arrow 44 by 0. 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
Is always in friction, and this friction causes
The microcapsule toner 1 frictionally charged by the charging blade 35 is electrostatically adsorbed and carried on the surface of the carrying roller 36 that is charged with the opposite polarity to the microcapsule toner 1.

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

As described above, the microcapsule toner 1 applied on the intermediate belt 38 is exposed by the exposure source 58 controlled by the control unit 12 according to the image information read by the scanner section 28, Then, the uncured microcapsule toner 1 is destroyed by the magnetic force developing device 50, and the inclusions containing the color material and the like leak out.

FIG. 2 is a diagram showing a state of development by the magnetic force developing device 50. The magnetic force developing device 50 includes a rod-shaped developing magnet 51, and a shield case 52.
Is covered by. The developing magnet 51 may use either an electromagnet or a permanent magnet. The shield case 52 is made of a magnetic material such as iron, and its material, size, etc. are selected so that the magnetic field generated by the developing magnet 51 does not leak to the outside of the magnetic force developing device 50.

One magnetic pole of the developing magnet 51 is an intermediate belt 38 carrying the microcapsule toner 1 after exposure.
The other magnetic pole is in contact with a part of the shield case 52 and is attracted by a magnetic force.

The uncured microcapsule toner 1 is flatly deformed by the action of the magnetic field generated by the developing magnet 51, and the portion far from the magnetic poles of the wall material portion is deformed flat, resulting in destruction.

Also, the cured microcapsule toner 1
Since the inclusions become hard and the entire microcapsule toner 1 becomes hard, the microcapsule toner 1 is not deformed even when receiving the magnetic field generated by the developing magnet 51. Therefore, only the uncured microcapsule toner 1 is selectively selected. Can be destroyed.

The intermediate belt 38 carrying the microcapsule toner 1 subjected to the developing action by the magnetic force in the magnetic force developing device 50 is composed of the magnetic roller 61 and the transfer roller 62 which are rotating in the direction of arrow 60. In the meantime, unnecessary substances are pressed very weakly so that they are not transferred onto the transfer roller 62, the inclusions are transferred onto the transfer roller 62, and unnecessary substances such as the wall material of the microcapsule toner 1 and the cured product are magnetic. It remains on the intermediate belt 38 due to the action of the magnetic field of the roller 61. At this time, the efficiency of transferring the inclusions onto the transfer roller 62 can be increased by heating the magnetic roller 61 with a heater or the like (not shown).

Here, the magnetic roller 61 is a well-known magnetic roller.
It is constructed like a magnet roller in a component electrophotographic copying machine.

Further, the transfer roller 62 is made of a resin or the like, and a material and a surface state having good wettability with the inclusion can be selected.

As described above, at the time of development, only the microcapsule toner 1 that has not been photopolymerized and cured is destroyed, and the inclusions containing the coloring material are carried on the transfer roller 62.

Further, unnecessary materials such as the wall material and the cured material of the microcapsule toner 1 remaining on the intermediate belt 38 after the pressure development are removed by sliding with the cleaning blade 64, and are discarded in the dust box 66. To be

The image receiving paper 70 stored in the image receiving paper cassette 68 is fed by the paper feeding roller 72, and is transferred by the paper guide 74 and the paper guide roller 76 to the nip roller 80 rotating in the direction of arrow 78 and the transfer. Roller 6
2 is guided to a gap between the nip roller 80 and the transfer roller 62, and is pressed to transfer the inclusion containing the color material carried on the transfer roller 62 onto the image receiving paper 70. , An image is formed on the image receiving paper 70.

The image receiving paper 70 having the formed image.
Is guided by the paper discharge roller 82 and discharged to the exit tray 84.

As described above, the non-contact development using the magnetic development means allows the very simple and small device to selectively destroy only the uncured capsules, and the development means and the image receiving device. Prevents image stains and deterioration of maintainability due to adhesion of capsule walls and hardened capsules on paper, and enables stable formation of a uniform magnetic field over a wide range, resulting in good image formation without uneven coloring. be able to.

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 present invention.

For example, although static electricity and gravity were used as the application means of the microcapsule toner, other mechanical / chemical actions such as magnetism and physical adsorption may be used.

[0058]

As is apparent from the above description, in the image forming apparatus of the present invention, the wall member of the microcapsule toner contains the fine powder having magnetism, and the inclusion of the microcapsule toner leaks out. As a non-contact developing method, it is possible to downsize the apparatus by preventing the development of color unevenness at the time of development by including a magnetic force developing means using a magnetic force. It is possible to improve the separation failure from unnecessary materials such as a broken capsule wall and prevent image stains and noise.

[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 a diagram showing an outline of a magnetic force developing device used in the image forming apparatus of the present invention.

[Explanation of symbols]

 1 Microcapsule Toner 50 Magnetic Development Device 51 Development Magnet

Claims (1)

[Claims] 1. A wall containing inclusions containing at least a coloring material such as a leuco dye, a colored dye or a pigment and a polymerizable substance, and a resin containing a polymer or an inorganic material as a main component and containing a magnetic fine powder. In an image forming apparatus for forming an image by leaking the inclusions from a microcapsule toner composed of a member and transferring the leaked inclusions onto an image receiving material, the inclusions of the microcapsule toner are An image forming apparatus comprising magnetic force developing means using magnetic force as means for leaking.