JPH0196676A - Adhesion transfer method - Google Patents

Abstract

PURPOSE:To make the device simple and small in size by forming an adhesive layer of a polymer which swells with a swelling agent and has stickiness. CONSTITUTION:The adhesive layer of a transfer sheet 32 is formed of the polymer which swells with the swelling agent and has the stickiness and when this transfer sheet 32 is pressed against a photoconductor 10, the swelling agent operates on the adhesive layer, which swells. Namely, the adhesive layer before swelling has no stickiness, so the transfer sheet 32 need not have peeling paper on it and is handled similarly to normal paper, etc. Consequently, the need for a means for peeling and winding the peeling paper is eliminated and the structure of an electrophotographic printer or electronic copying machine is simplified and reduced in size, weight, and cost.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for transferring a toner image formed on a photoconductor by electrophotography onto a support, and in particular, a transfer method having an adhesive layer. This invention relates to an adhesive transfer method using a sheet.

(Prior art) Conventionally, an electrostatic latent image is formed by projecting an image of an original onto a negatively charged photoconductor or by irradiating a light beam modulated based on an image signal. 2. Description of the Related Art Electronic copiers or electrophotographic printers are known that develop an electrostatic latent image into a toner image and then transfer the toner image to a support such as paper.

On the other hand, various electrophotographic methods have been proposed that allow continuous tone images to be recorded with good gradation reproducibility. For example, in Japanese Patent Publication No. 49-38172 by the present applicant, an electrostatic latent image formed on a photoconductor is developed into a toner image using a developer, and then an adhesive tape is pressed onto the toner image to form a toner image. An electrophotographic process is disclosed in which the image is peeled off and the tape is then adhered to the final support.

As a method of transferring the toner image formed on a photoconductor to a support such as paper, electrostatic transfer using a corotron is widely used. It has been recognized that there is a problem with poor transfer efficiency in high-density areas and low-density areas. On the other hand, the so-called adhesive transfer method in which a toner image is transferred to an adhesive layer as described above has an extremely high transfer efficiency regardless of the image density, and is therefore advantageous for recording continuous tone images.

(Problem to be solved by the invention) However, in the conventional adhesive transfer method, a sheet with an adhesive layer that is sticky at room temperature is generally used, and this sheet has a release paper attached to the adhesive layer. When using this transfer sheet, it is necessary to have means for peeling off the release paper from the transfer sheet before the adhesive transfer process, and means for winding up the release paper that has been peeled off. Naturally, when such various means are used, the apparatus becomes more complicated and larger than when a corotron is used for transfer, resulting in higher costs.

Furthermore, it is necessary to attach, for example, the aforementioned final support or transparent sheet to the adhesive layer of the transfer sheet after the toner image has been transferred, to prevent the adhesive layer from getting dirty or sticking to fingers, etc. Providing means for pasting the transparent sheet etc. makes the device even more complicated and larger.

Therefore, an object of the present invention is to provide an adhesive transfer method that does not cause the above-mentioned problems.

(Means for Solving the Problems) In the adhesive transfer method of the present invention, the adhesive layer of the transfer sheet is formed from a polymer that becomes sticky when swollen by a swelling agent, and this transfer sheet is used as a photoconductor. The adhesive layer is characterized by causing the swelling agent to act on the adhesive layer and causing it to swell when pressed against the adhesive layer.

(Function) Since the adhesive layer before being swollen as described above does not have adhesive properties, the transfer sheet can be handled in the same way as ordinary paper, etc., without the need to overlay release paper. When the adhesive transfer is completed and the swelling agent evaporates from the adhesive layer, the adhesive layer is cured, so there is no need to attach a transparent sheet or the like to it.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings. .

FIG. 1 shows an example of an electrophotographic printer that transfers toner images by the method of the present invention.

A photosensitive drum 11 having a photoconductor 10 disposed on its circumferential surface is rotated in the direction indicated by the arrow by a driving means (not shown).

Around the photosensitive drum 11, a charger 12, an exposure section 13, a wet developing device 14,
Squeeze corona discharger 15, drum drying fan 16
, adhesive transfer means 17, static eliminator 18, cleaning roller 19, cleaning blade 20, and erasing lamp 21
is located.

“The exposure unit 13 is made of, for example, a semiconductor laser, a He-Ne
Laser light [22] consisting of a laser etc. and this laser light source 2
an optical modulator 24 such as an AOM (acousto-optic modulator) that modulates the intensity of a light beam (laser beam) 23 emitted from the laser beam 2; and a modulation circuit 25 that drives the optical modulator 24.
an optical deflector 2B, such as a polygon mirror, which reflects and deflects the modulated light beam 23 and scans it on the photoconductor 10 in a direction substantially perpendicular to the direction of rotation of the photoconductor (direction in which the arrow enters); and a scanning lens 27 consisting of an fθ lens that focuses the beam to a uniform beam diameter on the photoconductor lO.

On the other hand, the adhesive transfer means 17 is moved by a known means in the direction of arrow B, and is a pressure roller that can take a position in pressure contact with the photoconductor IO on the circumferential surface of the photoconductor drum 11 and a position away from the photoconductor IO. 30, a transfer sheet supply roller 33 that winds and stores the transfer sheet 32, and a swelling agent tank 36 on the surface of the transfer sheet 32 just before it is applied to the press roller 30.
It consists of a swelling agent application roller 39 for applying the swelling agent E therein. The transfer sheet 32 is, for example, a sheet of white paper having a polymer layer serving as an adhesive layer on one surface thereof, and is wound around the pressure roller 30 with this polymer layer on the outside, and is wrapped around the conveyance roller 37 consisting of a pair of nip rollers. .3B. These conveyance rollers 37.8B are each driven to rotate in the direction of the arrow by a drive means (not shown).

During image recording, the photosensitive drum 11 is rotated as described above. Then, a digital image signal Sd representing a continuous tone image is passed from an image signal supply device 41 to a correction table 42
The image signal S is sent to the A converter 43 and converted into an analog signal by the D/A converter 43, and is sent to the modulation circuit 25 described above. Note that the image signal Sd is converted into an image signal Sd' in the correction table 42 for gradation correction. The modulation circuit 25 drives the light modulator 24 based on the image signal S, whereby the light beam 28 is intensity-modulated in accordance with the image signal S.

By rotating the photosensitive drum 11 as described above,
The photoconductor lO is moved relative to the charger 12 and is uniformly charged by the charger 12. The --like charged photoconductor IO is irradiated with the light beam 23 deflected by the optical deflector 2B as described above.

This light beam 23 passes over the photoconductor lO by the above deflection.
As the photosensitive drum 11 is rotated, the light beam 23 performs sub-scanning, and as a result, the photoconductor 10 is scanned two-dimensionally by the light beam 23. As mentioned earlier, this light beam 23 is modulated based on the image signal S, and therefore, the electrostatic potential of the image carried by the image signal S appears on the photoconductor lO irradiated with this light beam 23. An image is formed.

This electrostatic latent image is developed into a toner image by a wet developer 14. This wet type developer 14 brings a liquid developer F, which is made by dispersing fine charged toner particles in an insulating liquid, into contact with the photoconductor IO, and causes the toner particles to be attached to the photoconductor IO by electrostatic attraction. By adhering, the electrostatic latent image is developed with toner.

The toner image thus formed is produced by a high-intensity light beam 2.
The area irradiated in step 3 has a lower density than the other, and the image signal S
The gradation of the continuous tone image that d is responsible for will be reproduced. After this development, the photosensitive drum 11 is dried by the squeeze corona discharger 15 and the drum drying fan te.

When it is detected or determined by known means that the toner-developed portion of the photoconductor IO has been fed just before the position facing the pressure roller 30, it is separated from the photoconductor drum 11 until then. The pressing roller 30, which had been in use, is moved so as to press against the photosensitive drum 11, and at the same time, the conveying roller 37.3g is driven. Further, the swelling agent application roller 39 is rotated by a driving means (not shown), and the second
As shown in the figure, the swelling agent E in the swelling agent tank 3B is applied to the polymer layer 32a of the transfer sheet 32. The polymer layer 32a is made of a polymer that becomes sticky when swollen by the swelling agent E, and specific combinations of such a polymer and the swelling agent E include polystyrene, polyvinyl butyral, Examples include combinations of polyester, polyvinyl acetate, styrene-butadiene copolymer, ethylene-vinyl acetate copolymer, vinyltoluene-acrylic copolymer, etc., and isopers (E, G, H, etc.).

By moving the pressure roller 30 as described above, the transfer sheet 32 has a photoconductor on the polymer layer 32a side.
It is pressed against O. The pressure roller 30 is the photosensitive drum 1
1 and the conveyance rollers 37 and 38 are rotated, so that the transfer sheet 32 comes into pressure contact with the photoconductor 10 and moves at the same speed as the photoconductor 10. At this time, the transfer sheet 32
Since the polymer layer 32a has become sticky due to the action of the swelling agent E, as shown in detail in FIG. transferred to. The transfer sheet 32 on which the toner image on the photoconductor lO has been adhesively transferred is transferred to the conveyor roller 37.
．． 38, the swelling agent Ef) evaporates from the polymer layer 32a, and the polymer layer 32a hardens. The transfer sheet 32 that has passed between the conveyance rollers 87 and 38 is cut by the cutter 45 into image forming areas. As a result, as shown in FIG. 3, a print 50 in which a continuous tone image is recorded with toner T on a transfer sheet 32 as a support is obtained. In this print 50,
Since the above-mentioned polymer layer 32a to be passed through has already been hardened,
Even if you touch the printed surface with your fingers, the image will not get dirty, and the printed surface will not stick to your fingers.

After the adhesive transfer of the toner image, the photoconductor lO is transferred to a static eliminator 18.
The charge is removed by the cleaning roller 19 and the cleaning blade 20, and the charge is optically removed by the erasing lamp 21, so that it can be used for the next image recording.

The embodiments of the present invention applied to electrophotographic printers that record continuous tone images have been described above, but the adhesive transfer method of the present invention can be similarly applied to recording or copying black and white binary images. be.

(Effect of the invention) As explained in detail above, according to the adhesive transfer method of the present invention,
Since there is no need for a release paper that covers the adhesive layer, there is no need for a means to peel off or wind up the release paper, which simplifies the structure of electrophotographic printers and electronic copying machines, making them smaller and lighter and reducing costs. Realized. Furthermore, according to the method of the present invention, there is no need to attach a transparent sheet or the like to the surface of the transfer sheet after the toner image is transferred, so there is no need for means for handling this transparent sheet, and from this point of view, it is also possible to use an electrophotographic printer or an electronic copying machine. This will make the machine smaller and lighter, and reduce costs.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a schematic diagram showing an example of an apparatus for implementing the method of the present invention, Fig. 2 is a side view showing an enlarged part of the above-mentioned apparatus, and Fig. 3 is a schematic diagram showing an example of an apparatus for implementing the method of the present invention. FIG. 2 is a perspective view showing a print obtained by toner image transfer. lO... Photoconductor 11... Photosensitive drum 12... Charger 13... Exposure section 14.
・Wet type developer 17 ・Adhesive transfer means 22 ・
...Laser light source 23...Light beam 24...
Light modulator 25...Modulation circuit 26...Light deflector 30...Press roller 32...Transfer sheet 32a...Polymer layer 3B...Swelling agent tank 37.38...Conveyance roller 39 ... Swelling agent application roller 41 ... Image signal supply device 42 ...
Correction table E... Swelling agent F... Liquid developer T... Toner Figure 2 Figure 3

Claims (1)

[Scope of Claims] In an adhesive transfer method in which a transfer sheet having an adhesive layer is pressed against a photoconductor carrying a toner image on the surface of the photoconductor, the toner image is transferred to the adhesive layer, the adhesive layer comprising: An adhesive characterized in that it is formed from a polymer that becomes sticky when swollen by a swelling agent, and when the transfer sheet is pressed against the photoconductor, the swelling agent acts on the adhesive layer to cause it to swell. Transcription method.