JPH032781A - Image fixing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an image fixing method, and more particularly to a method for fixing images by simply forming a transparent protective film.

[Prior Art] Conventionally, an electrophotographic image is obtained by performing imagewise exposure on a photosensitive material whose surface is uniformly charged by corona discharge to form an electrostatic latent image, and then performing wet development using a liquid developer. Although the liquid developer contained a fixing resin, the amount thereof was not sufficient, and as a result, the formed images were easily scratched and smudged. Furthermore, in photosensitive materials formed by dispersing photoconductive fine particles such as zinc oxide and titanium oxide in a resin binder,
Because the surface needs to be porous, the image surface formed on the surface is not flat, and the reflected light from the surface has an increased diffuse reflection component, making it difficult to express particularly high-density areas of the image. was insufficient.

Therefore, a method of forming a protective film of a resin binder on the obtained electrophotographic image is generally known. For example, a method in which a resin solution prepared by dissolving a resin binder in an organic solvent is applied to the image surface and dried to form a transparent protective film, or a method in which a heat-melting transparent resin layer is formed on a base sheet and this is applied to the image surface There is a method of forming a protective film by peeling off the base sheet after heat-sealing the image to the surface, leaving a transparent resin film on the image surface.

[Problems to be Solved by the Invention] However, in the former method, in order to obtain a resin solution that can be applied without affecting the formed image, the solvent for dissolving the resin for forming the protective film must be used in a photosensitive manner. It is necessary not to dissolve the material or image fixing resin. Therefore, the range of solvents that can be used is limited, and resin selection is difficult because both transparency and solubility must be considered.

In particular, when forming a protective film on an electrophotographic image obtained by wet development, a two-time solvent drying process is required, which is undesirable from the standpoint of energy and environmental pollution caused by solvent vapor emissions. do not have.

On the other hand, in the latter method, in order to create a protective film on one electrophotographic image, a protective film forming sheet of the same area is required, so it is necessary to have a large amount of protective film forming sheets stocked in the equipment. Moreover, since the base sheets of these protective film forming sheets are disposable, the cost for image output increases.

The present invention has been made to solve the above-mentioned problems, and its object is to inexpensively and efficiently form a transparent protective film on various images such as electrophotographic images.

[Means for Solving the Problems] In order to achieve this object, the image fixing method of the present invention is characterized in that transparent resin fine powder is electrostatically applied onto an image and then heated and fixed.

[Function] According to the present invention having the above configuration, the transparent resin fine powder adhering to the image is heated and melted to form a uniform transparent resin layer, thereby protecting the image.

[Example] Hereinafter, an example embodying the present invention will be described with reference to the drawings.

FIG. 2 shows an example of an image copying apparatus equipped with a resin powder coating device. A storage case 11 in which the photoreceptor sheet 1 is wound in a roll is installed inside the apparatus main body 10 . As the photosensitive sheet 1, a known one in which zinc oxide or titanium oxide is dispersed in a resin binder together with various sensitizers is used. When the copying process begins, photoreceptor sheet 1
is pulled out from the storage case 11 and carried along the guide, and its leading end is fixed onto the stage drum 13 by a fixing means (not shown). As the stage drum 13 rotates clockwise, the photoreceptor sheet 1 is pulled out and brought into close contact with the stage drum 13. At this time, the surface of the photoreceptor sheet 1 is uniformly charged by the scorotron 14. The stage drum 13 continues to rotate,
Exposure of the photoreceptor sheet 1 is then performed. That is, the lamp 15 is turned on and the mirror 20 and lamp 15 are scanned in the direction of arrow A in the figure in synchronization with the rotational speed of the stage drum 13. Mirror 19M119M is scanned in the same direction at half the speed of mirror 20 and lamp 15, and the distance between the document on document table 16 and stage drum 13 is kept constant.

The light reflected by the original is reflected by mirrors 20.19M and 19M.

An image is formed on the photoreceptor sheet 1 on the stage drum 13 by the actions of the lenses 19S and 19S and the lens shape 17. At this time, a blue filter 18B is inserted into the optical path, and only the blue component of the light reflected from the original is formed on the photoreceptor sheet 1, and an electrostatic latent image formed by the blue light is formed on the photoreceptor sheet 1. is formed.

Note that when the photoreceptor sheet 1 is pulled out from the cartridge 11 by the required amount, the vapor cutter 12 rotates to cut the photoreceptor sheet 1, and the rear end of the photoreceptor sheet 1 is also fixed on the stage drum 13 by the fixing means. The entire photoreceptor sheet 1 is tightly attached and fixed onto the stage drum 13.

The photosensitive sheet 1 on which the electrostatic latent image has been formed is then sealed with a solvent used for toner liquid by a bri-wet mechanism 27, and is then passed through a wet developing device 21Y.
Yellow development is performed.

As the stage drum 13 rotates, the photosensitive sheet 1 carrying the yellow image is neutralized by the action of the corona static eliminator 26, in preparation for the next and subsequent drawings.

Thereafter, a two-color image is formed by being similarly charged by the scorotron 14, exposed to green light, and developed with magenta toner.

Further, after being uniformly charged, the photoreceptor sheet 1 is exposed to red light and then developed in cyan to form a full color image on the photoreceptor sheet 1.

When a full color image is formed in this way, the photoreceptor sheet 1 is removed from the stage drum 1 by the action of the peeling blade 24.
3 and fixed on the drying drum 22 by fixing means (not shown).

Warm air is blown from the dryer 23 onto the photoreceptor sheet 1 fixed on the drying drum 22 to dry the photoreceptor sheet 1.
The solvent remaining on top is removed.

When drying is completed, the photoreceptor sheet 1 is peeled off from the drying drum 22 by the peeling blade 29, and then fixed on the conveying drum 2.

FIG. 1 is a diagram showing an extracted portion of a transparent resin powder coating apparatus according to an embodiment of the image fixing method of the present invention.

A photoreceptor sheet 1 carrying an electrophotographic image is held on a conveyance roller 2 by suction means or fixing means (not shown).

3 is transparent resin powder. This powder is 1 to 30μ
More preferably, it has a diameter of 8 to 15 μm, and its material is polystyrene, polymethyl methacrylate,
The main component is a transparent resin such as a styrene n-butyl methacrylate copolymer, a polyester resin, or an epoxy resin, to which a charge control agent and additives are added as necessary.

Transparent resin powder 3 is stored in case 7.

At the top of the case 7, there is a donor roller 4 and a conveyor roller 2.
It is arranged so as to have an interval of 0.05 to 5 mm, more preferably 0.5 to 3 mm, from the upper photoreceptor sheet 1.

A feed roller 6 faces the donor roller 4 at a small distance.

A blade 5 keeps the thickness of the transparent resin powder on the donor roller 4 constant.

In such a configuration, transparent resin powder 3 is applied onto photoreceptor sheet 1 . First, as the donor roller 4 and the donor roller 6 rotate, the transparent resin powder 3 is charged by contact and friction and adheres to the surface of the donor roller 4 . Then, the thickness of the layer of transparent resin powder 3 on donor roller 4 is regulated by the action of blade 5 and the action of transparent resin powder 35 on donor roller 4 . In this embodiment, it is assumed that the material of the transparent resin powder 3 is selected so as to be positively charged, and a voltage is applied between the donor roller 4 and the conveyance roller 2 as shown in FIG. Then, the transparent resin powder 3 on the donor roller 4 is
It moves onto the photoreceptor sheet 1 due to electrostatic force.

The thickness of the layer of transparent resin powder 3 formed on the photoreceptor sheet 1 is determined by the distance between the conveyance roller 4 and the donor roller 2, the relative speed of rotation, the applied voltage, etc. A thickness of about 30 μm is desirable.

After forming the layer of transparent resin powder 3 on the photoreceptor sheet 1 in this way, the photoreceptor sheet 1 is passed through a heat fixing roll or the like, so that the transparent resin powder 3 is melted and integrated. , resulting in a transparent resin layer.

In this embodiment, after the transparent resin powder layer is formed on the photoreceptor sheet 1, the conveyance roller is reversed, the photoreceptor sheet is peeled off from the conveyance roller 2 by the peeling blade 24, and the heat fixing roller 25 .25, the transparent resin powder is dissolved to form a uniform transparent film, which strongly protects the formed color image.

Next, other embodiments will be described.

FIG. 3 is an example of an image output device equipped with a resin powder coating device. Since there are many parts in common with the first embodiment,
Common parts are numbered the same and explanations are omitted.

In this embodiment, exposure is performed using laser light. This laser light is in a wavelength range to which the photoreceptor sheet 1 is sensitive.

The exposure device 40 is a known device equipped with a laser light source 41, a polygon mirror 42 rotated at high speed by a motor 43, and a lens system 44. A control device (not shown) applies laser light to the photoreceptor sheet 1, which has been uniformly charged in advance. to form an electrostatic latent image.

As in the first embodiment, the electrostatic latent image is developed, but in this embodiment, the order of development is particularly limited by selecting a laser light source in a wavelength range that is less absorbed by the toner. Never. When a full-color image is formed on the photoreceptor sheet 1 by repeating the process of uniform charging, laser exposure, and development (-static discharge), as in the first embodiment,
After the drying process, transparent resin powder is applied.

In this embodiment, the photoreceptor sheet 1 is
When the photoreceptor sheet 1 is fixed thereon, the corotron 8 causes the photoreceptor sheet 1 to be uniformly charged again. Subsequently, as the conveying roller 2 rotates, the donor roller 4, on which the transparent resin powder 3 charged to the opposite polarity to that of the photoreceptor sheet 1 is attached, approaches the photoreceptor sheet 1, so that the transparent resin powder 3 moves onto the photoreceptor sheet 1 due to electrostatic force. After this, as in the first embodiment, the conveyance roller 2 holding the photoreceptor sheet 1 rotates in the opposite direction, and the peeling blade 2
4, the photosensitive sheet 1 is peeled off from the conveying roller 2. The transparent resin powder is melted by the heat fixing rollers 25 and 25 to form a uniform transparent film, and the color image formed on the photoreceptor sheet 1 is strongly protected and is ejected to the ejection tray 30 with the image side facing up. be done.

Although an example of fixing an electrophotographic image has been described above, the present invention can also be used for fixing an image obtained by, for example, a photosensitive pressure-sensitive medium.

[Effects of the Invention] As is clear from the detailed description above, according to the fixing method of the present invention, a transparent resin film can be formed on an image easily and at low cost, and the scattered light components of the obtained image can be As a result, image quality is improved and dirt and scratches can be prevented.

[Brief explanation of the drawing]

1 to 3 show embodiments embodying the present invention, and FIG. 1 is a diagram showing the principle of a transparent resin powder coating device, and FIG. 2 is a diagram showing the principle of a transparent resin powder coating device. FIG. 3 is a schematic sectional view of an image output device equipped with a transparent resin powder coating device. In the figure, 1 is a photoreceptor sheet, 2 is a transport roller 3 is transparent resin powder, 4 is a donor roller, 5 is a blade, 6 is a feed roller, 7 is a case, and 25 is a heat fixing roller.

Claims (1)

[Scope of Claims] 1. An image fixing method characterized by electrostatically applying transparent resin fine powder onto an image and fixing it by heating. 2. The image fixing method according to claim 1, wherein the transparent resin fine powder is supplied onto the image in a dry state.