JPH0675225B2 - Adhesive transfer method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an adhesive transfer method for transferring a toner image formed on a photosensitive drum by an electrophotographic method to a transfer sheet having an adhesive surface. The present invention relates to an adhesive transfer method that can improve accuracy and can simplify a transfer mechanism.

(Prior Art) Conventionally, an electrostatic latent image is formed on a uniformly charged photoconductor by projecting an original image or irradiating a light beam modulated based on an image signal. An electronic copying machine or an electrophotographic printer is known in which an electrostatic latent image is developed into a toner image and then the toner image is transferred onto a support such as paper.

On the other hand, various electrophotographic methods capable of recording a continuous tone image with good gradation reproducibility have been conventionally proposed. For example, Japanese Patent Publication No. 49-38172 by the applicant of the present invention discloses that after developing an electrostatic latent image formed on a photoconductor into a toner image with a developer,
An electrophotographic method is disclosed in which an adhesive (adhesive) tape is pressure-bonded to the toner image to peel off the toner image, and then the tape is adhered to a final support.

As a method of transferring a toner image formed on a photoconductor to a support such as paper, a method of electrostatically transferring using a corotron is widely used, but in this transfer method, It has been confirmed that the transfer efficiency of the high density portion and the low density portion is poor. On the other hand, as described above, the so-called adhesive transfer method of transferring the toner image to the adhesive layer has an extremely high transfer efficiency regardless of the image density, and is therefore advantageous for recording a continuous tone image. An example of an adhesive transfer device for carrying out such an adhesive transfer method is shown in FIG.

In the illustrated apparatus, a photosensitive drum 110 having a photoconductor 111 provided on its peripheral surface is rotated in the direction of an arrow and a toner image is formed on its peripheral surface by a toner image forming means 120 arranged around the photosensitive drum 110. . The toner image forming unit 120 includes a charger 121 and an exposure unit 12 along the rotation direction of the photosensitive drum 110.
2, a developing device 123, a drum drying means 124, a static eliminator 125, a cleaning roller 126, and the like are provided, and the photosensitive drum 110 is uniformly charged by a charger 121, and then, according to image information in an exposure section 122. An electrostatic latent image is formed by the modulated and modulated light beam, and the electrostatic latent image is developed as a toner image by the developing device 123. The toner image thus formed on the photosensitive drum 110 is dried by the drum drying means 124, and then adhered to the transparent belt-shaped transfer sheet 101 having an adhesive surface and suspended at the transfer roller 130 at the position P ₁ . Transcribed. The transfer sheet 101 is sent from the sheet supply roller 131 in a state of being attached to the strip-shaped release paper 102, and is held by the nip rollers 132A and 132B at a position where it is taken up by the release paper take-up roller 133 from the release paper 102. Stripped off. The peeled transfer sheet 101 is suspended on the transfer roller 130 with the adhesive surface facing outward, and is brought into contact with the photosensitive drum 110 and moved at the same speed as the photosensitive drum 110 as described above, and the toner image is transferred.

The transfer sheet 101 on which the toner image has been transferred is further passed between the pressure bonding rollers 140A and 140B, which are a pair of nip rollers. On the other hand, a support sheet 103 made of strip-shaped paper or the like is drawn out from the support sheet supply roller 141 toward the pressure rollers 140A and 140B, and the support sheet 103 passes between the pressure rollers 140A and 140B together with the transfer sheet 101. Then, it is attached to the transfer sheet 101. In this way, the transparent transfer sheet 101 and the support sheet 1 which are in a state of being adhered to each other.
03 is cut into each image forming area by the cutter 142.

(Problems to be Solved by the Invention) However, in the above-mentioned pressure-sensitive adhesive transfer method, the belt-shaped transfer sheet is suspended from the transfer roller while being pressed against the pressure roller.
Since it is designed to pass between 140A and 140B,
If there is a difference between the drive speed of the photosensitive drum and the drive speed of the pressure roller during transfer, the transfer sheet may be bent or pulled, and the image transferred at the position P ₁ may be cracked or distorted. Further, since the transfer sheet to which the toner image is transferred is handled in a state in which the release paper is adhered, the adhesive transfer device uses a means for peeling the release paper from the transfer sheet before the adhesive transfer or winding the peeled release paper. Means are required, and there is a problem that the structure of the device becomes complicated and increases in size.

Therefore, an object of the present invention is to provide an adhesive transfer method capable of performing good transfer without causing cracks or distortions in a toner image and simplifying the configuration of the apparatus. .

(Means for Solving Problems) The adhesive transfer method of the present invention is a transfer drum having a transfer sheet supply roller formed by winding a belt-shaped transfer sheet having an adhesive surface and having a transfer sheet outlet on the peripheral surface. To a predetermined direction to wind and hold the transfer sheet on the peripheral surface with the adhesive surface facing outward, and hold the transfer drum relative to the photosensitive drum carrying the toner image on the surface. Move it and press it against the photosensitive drum,
While rotating the transfer drum together with the photosensitive drum, the toner image on the photosensitive drum is transferred onto the adhesive surface of the transfer sheet, and the transfer drum is moved relative to the photosensitive drum to separate from the photosensitive drum. The transfer sheet is moved relative to the pressing roller and brought into pressure contact with the pressing roller, the transfer drum is reversed, and the transfer sheet is peeled from the transfer roller at a position where the transfer roller is pressed against the pressing roller. These sheets are attached to each other by passing the belt-shaped support sheet together with the transfer sheet, and the both attached sheets are passed between the transfer drum and the sheet conveying and holding means provided on the downstream side of the pressing roller to transfer the transfer sheet. After all the transfer sheets wound on the peripheral surface of the drum are peeled off, the transfer sheet and the support sheet attached to each other are moved forward. The transfer drum is cut at a position on the downstream side of the sheet conveying / holding means, the transfer drum is moved relative to the pressing drum and separated from the pressing drum, and the transfer sheet is held while being held by the sheet conveying / holding means. To rotate the transfer sheet in the normal direction to wind the transfer sheet around the peripheral surface of the transfer drum, cut the transfer sheet at a position between the transfer drum and the sheet conveying and holding means, and hold the end of the cut transfer sheet on the transfer drum. It is characterized by that.

The sheet conveying / holding means may be one that can convey and hold the adhered transfer sheet and supporting sheet, for example, a nip roller, a combination of a guide plate and a roller, a small endless belt, etc. Is applicable. Further, the reason why the stuck transfer sheet and support sheet are cut at a position on the downstream side of the sheet conveying and holding means is to keep the ends of the transfer sheet and the supporting sheet after being cut by the sheet conveying and holding means. This cutting may be performed in the vicinity like the sheet conveying and holding means, and the transfer sheet may be appropriately conveyed so that the portion on which the toner image is formed is located downstream of the cutting position prior to this cutting. Good.

(Operation) By incorporating the transfer sheet supply roller inside the transfer drum as described above and feeding the transfer sheet from the transfer sheet supply roller and directly winding the transfer sheet around the transfer drum, the release paper is attached to the transfer drum. Since it is no longer necessary to handle the transfer paper, there is no need for means for peeling off the release paper or winding means, and there is no need for transferring the transfer sheet outside the transfer drum, so that the adhesive transfer device can be simplified and made compact. Further, the transfer drum on which the transfer sheet is wound is selectively brought into pressure contact with one of the photosensitive drum and the pressure roller at the time of transfer and at the time of adhering to the support sheet. As a result, the disadvantage that the toner image transferred to the transfer sheet is cracked does not occur.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view showing an example of an adhesive transfer device for carrying out the adhesive transfer method of the present invention.

The photosensitive drum 10 having the photoconductor 11 on its peripheral surface is rotated in the direction of arrow A by a driving unit (not shown). Around the photosensitive drum 10, along the rotation direction of the drum 10, a charger 21, an exposure unit 22, a wet developing unit 23, a drum drying unit 2
4, a toner image forming unit 20 including a static eliminator 25, a cleaning roller 26, and a cleaning blade 27 is arranged.

The exposure unit 22 is a laser light source 22a made of, for example, a semiconductor laser or a He-Ne laser, and an AOM (acousto-optical modulator) that intensity-modulates a light beam (laser beam) 22b emitted from the laser light source 22a. Optical modulator 22c, a modulation circuit 22d for driving the optical modulator 22c, and the modulated light beam 22b are reflected and deflected to a direction substantially perpendicular to the rotation direction (direction of arrow A) on the photosensitive drum 10. An optical deflector 22e such as a polygon mirror for scanning and a light beam 22b for the photosensitive drum
The scanning lens 22f is composed of an fθ lens that focuses the light beam on the optical fiber 10 to have a uniform beam diameter.

When recording an image on the photosensitive drum 10, the drum is rotated in the direction of arrow A, and a digital image signal Sd that carries a continuous tone image is sent from the image signal supplier 61 through the correction table 62 to the D / A converter. The image signal S sent to the D / A converter 63 and sent to the D / A converter 63 is sent to the modulation circuit 22d. The modulation circuit 22d is based on the image signal S and is based on the optical modulator 2
2c is driven, whereby the light beam 22b is intensity-modulated corresponding to the image signal S.

By rotating the photosensitive drum 10 as described above, the photoconductor 11 moves relative to the charger 21, and at that time, the charger.
21 is uniformly charged. Uniformly charged photoconductor 11
The light beam 22b deflected by the light deflector 22e as described above is applied to the beam. The light beam 22b one-dimensionally scans the photoconductor 11 by the above deflection (main scanning), and the photosensitive drum 10 is rotated to perform subscanning of the light beam 22b. It is scanned two-dimensionally by the light beam 22b. As mentioned earlier, this light beam
22b is modulated based on the image signal S, so that on the photoconductor 11 irradiated with this light beam 22b,
An electrostatic latent image of the image carried by the image signal S is formed.

This electrostatic latent image is developed into a toner image by the wet type developing device 23. In this wet type developing device 23, a liquid developer F made by dispersing fine toner particles having a charge in an insulating liquid is brought into contact with the photoconductor 11, and the toner particles are made to contact the photoconductor 11 by electrostatic attraction. By attaching the toner, the electrostatic latent image is developed with toner. The toner image thus formed has a lower density in a portion irradiated with the light beam 22b having a higher intensity, and the gradation of the continuous tone image carried by the image signal Sd is reproduced. After this development, the photosensitive drum 10 is dried by the drum drying means 24.

On the other hand, in the vicinity of the photosensitive drum 10, a first position apart from both the photosensitive drum 10 and a heat roller 40 described later, a second position in which only the photosensitive drum 10 is in pressure contact, and only the heat roller 40 is in pressure contact. The transfer drum 30 is arranged so as to be movable in the third position. The transfer drum 30 is rotatable in the directions of arrow B and B '. Here, for convenience, the rotation in the direction of arrow B is referred to as forward rotation, and the rotation in the direction of arrow B'is referred to as reverse rotation.

The transfer drum 30 is a transfer sheet supply roller formed by winding a transparent belt-shaped transfer sheet 1 having an adhesive surface 1a therein.
Equipped with 31, the transfer sheet take-out port provided on the peripheral surface
The transfer sheet 1 taken out from the support member 34 has a substantially cylindrical support 32.
On the surface of. The transfer sheet supply roller 31 winds the transfer sheet 1 with its adhesive surface 1a facing outward, and the transfer sheet 1 drawn onto the transfer drum 30 is wound up with the adhesive surface 1a facing outward. Transfer sheet outlet at the tip
It is attached to the succeeding transfer sheet in the vicinity of 34 and held on the peripheral surface of the transfer drum for a predetermined length. Further, in this embodiment, the pin 33 is used to pierce the overlapped portion of the transfer sheet 1 in order to further secure the attachment. The support 32 of the transfer drum 30 has an aluminum layer 32a, as shown in FIG.
A silicon rubber layer 32b which is provided on the transfer rubber and prevents transfer of heat into the drum when the transfer drum is in pressure contact with the heat roller 40, and a Teflon layer 33c provided on the silicon rubber layer 32b. . Teflon layer 33c is a support
The surface of 32 is made slippery so that the transfer sheet 1 can be smoothly wound around the transfer drum 30.

The transfer drum 30 formed by winding the transfer sheet 1 on the peripheral surface as described above is located immediately before the position where the portion of the photosensitive drum 10 that has been toner-developed by the toner image forming means 20 faces the transfer drum 30 as described above. When it is detected or discriminated by a known means that it has been sent up to, it moves in the direction of arrow C as shown in FIG. 3 to take the second position, and comes into pressure contact with the photosensitive drum 10. The transfer sheet 11 on the transfer drum 30 is pressed against the photoconductor 11 in order from the leading end thereof, and the transfer drum 30 is driven by the photosensitive drum 10 rotating in the direction of arrow A to reversely rotate in the direction of arrow B ′. The toner image T on the conductor 11 is transferred to the adhesive surface 1a of the transparent transfer sheet 1.

On the other hand, as shown in FIG. 1, the heat roller 40, which is a pressing roller, is arranged at a position substantially facing the photosensitive drum 10 via the transfer drum 30, and a support provided above the heat roller 40. From the sheet supply roller 41, the roller 41
The belt-shaped support sheet 3 made of paper or the like is fed toward the heat roller 40 by rotating in the direction of the arrow E, and the support sheet 3 contacts the heat roller 40 and
The heat roller 40 is passed between a pair of nip rollers 50A and 50B which are sheet conveying and holding means provided below the heat roller 40.

Almost the entire circumference of the transfer drum 30 contacts the photoconductor 11.
When the transfer of the toner image to the transfer sheet 1 is completed, the transfer drum is moved in the direction of arrow D as shown in FIG. 4 and is arranged at the third position, and is separated from the photosensitive drum 10 and the heat roller 40 is moved. And press. The transfer drum 30 arranged in the third position is driven by the heat roller 40 rotating in the direction of arrow F to reversely rotate in the direction of arrow B ', and the transfer sheet 1 carrying the toner image is sequentially transferred from the front end of the heat roller 40.
It is peeled off at a pressure contact position with and is attached to the support sheet 3. Prior to the peeling of the transfer sheet 1, the pins 33 retract backward and release the transfer sheet. Further, at the time of this attachment, the toner image is fixed by the heat generated from the heat roller 40. The fixing by such heat does not necessarily have to be performed by the heat roller 40, and the heat roller may be an ordinary pressing roller and a heating unit may be separately provided.

In this way, the transfer sheet 1 and the support sheet 3 are adhered by the transfer drum 30 and the heat roller 40, and the both adhered sheets pass through the nip rollers 50A and 50B, and as shown in FIG. When all of the transfer sheet 1 wound around the peripheral surface of 30 is peeled off, the transfer sheet and the support sheet to which the cutters 51A and 51B provided on the downstream side of the nip rollers 50A and 50B are attached are cut. In addition, this cutter 51A, 51
Prior to this cutting, B also cuts the leading end portion 3'of the supporting sheet to which the transfer sheet 1 is not attached, as shown in FIG. The rear portion of the transfer sheet 1 wound around the transfer drum 30 is a blank portion that does not carry a toner image. Although it is not shredded, if the toner image is transferred to almost the entire surface of the transfer sheet wound around the transfer drum, after peeling off the entire transfer sheet, the transfer sheet is moved to the required length by the nip roller. The transfer sheet 1 on which the toner image is formed by pulling out 1 is transferred to the downstream side of the cutters 51A and 51B, and then cut. After the support sheet 3 is attached to the transfer sheet 1 as described above, the transparent transfer sheet 1 is formed on the support sheet 3 as shown in FIG. 6 by cutting these sheets for each image area as described above. Is adhered, and a print 6 in which a continuous tone image is recorded by the toner T is obtained between the sheets 1 and 3.

After the transfer of the toner image, the photoconductor 11 is neutralized by the static eliminator 25, cleaned by the cleaning roller 26 and the cleaning blade 27, and is ready for the next image recording.

On the other hand, as shown in FIG. 7, the transfer roller 30 moves in the direction of arrow G while holding the front end of the transfer sheet 1 by the nip rollers 50A and 50B and returns to the first position. At the first position, the transfer drum 30 rotates in the normal direction of arrow B. When the transfer drum 30 rotates in the normal direction, the transfer sheet supply roller 31 in the transfer drum 30 is rotated in the direction of arrow H to send out the transfer sheet 1, and the transfer sheet 1 is rewound on the transfer drum 30. As shown in FIG. 8, when the transfer sheet 1 is wound around the entire circumference of the transfer drum 30, a cutter 52 provided between the nip roller 50 and the transfer drum 30.
Moves in the direction of the arrow to cut the transfer sheet 1. The cut end of the transfer sheet 1 moves in the direction of arrow I by itself and adheres onto the transfer drum 30. If the cut end does not adhere well to the transfer drum 30, a means for adhering the end may be provided separately.

When the transfer sheet 1 is cut by the cutter 52 and attached onto the transfer drum as described above, the bin 33 again projects to fix the end portion of the transfer sheet. The transfer drum 30 having the transfer sheet wound around the peripheral surface again moves to the second position and can transfer a new toner image.

As described above, according to the method of the present embodiment, by storing the transfer sheet wound around the transfer sheet supply roller in the transfer drum and directly winding the transfer sheet by the transfer drum,
There is no need to attach release paper to the transfer sheet,
The structure of the transfer device is simplified. In addition, since the transfer sheet is selectively pressed against the photosensitive drum and the pressing roller while being wound around the transfer drum, there is no problem that the toner image is cracked even when the driving speeds of the photosensitive drum and the pressing roller are different.

In the above embodiment, only the transfer drum is moved with respect to the photosensitive drum and the heat roller, but the above movement may be performed relatively. The transfer drum may be moved relative to the photosensitive drum and / or the heat roller. It is also possible to move.

Further, if the rotation for winding the transfer sheet around the peripheral surface of the transfer drum is forward, the rotation at the time of attaching the transfer sheet to the support sheet needs to be reverse, but the rotation at the time of transfer is It may be forward or reverse. Further, any means may be used for holding the transfer sheet on the transfer drum. Another embodiment of the present invention will be described below with reference to FIG. The same parts as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, the transfer drum 30 'rotates in the direction of arrow J and rotates in the direction of arrow J'. As shown in the figure, the transfer drum 30 'is pressed against the photosensitive drum 10 rotating in the direction of arrow A while the transfer sheet 1 is wound around the peripheral surface, and is transferred while being rotated forward. The transfer sheet 1 wound around the transfer drum 30 'has its front end adsorbed and fixed by the vacuum suction means 33', and the transfer is performed from the rear end portion of the wound transfer sheet by a predetermined length. After the margin is formed, the process is sequentially performed. Further, a pair of nip rollers 35A 'and 35B' are provided in the transfer sheet take-out port 34 'so that the transfer sheet 1 is not fed out from the transfer sheet supply roller 31' in the transfer drum 30 'during transfer.

When the transfer is completed, the transfer drum 30 moves to a position where it comes into pressure contact with the heat roller 40, and is rotated in the direction of arrow J ′ following the heat roller 40 that rotates in the direction of arrow K to support the transfer sheet 1 in order from the leading end thereof. Stick on sheet 3. Both the adhered sheets further pass between the nip rollers 50A and 50B.

When the transfer sheet 1 wound around the transfer drum 30 'is completely peeled off, the transfer sheet 1 and the support sheet 3 attached to each other are cut by the cutters 51A and 51B. Then, the transfer drum 30 'is arranged so that the end of the transfer sheet 1 is moved to the nip roller 50A,
Move the heat roller 40 away from the heat roller 40 while holding it by 50B
In the normal direction, and the transfer sheet 1 is newly wound around the peripheral surface. At that time, the nip roller 35 in the transfer drum 30 'is
A ′ and 35B ′ rotate in the direction in which the transfer sheet 1 is sent out.
When the transfer sheet 1 is wound around substantially the entire circumference of the transfer drum 30 ', the transfer sheet 1 is cut by the cutter 52 provided between the nip rollers 50A and 50B and the transfer drum 30', and the end portion of the transfer sheet on the cutting side is cut. Is sucked by the vacuum suction means 33 'and held on the transfer drum 30'.

In any of the above-described embodiments, when it is desired to display a plurality of images side by side on the final film, the plurality of images may be transferred at once to the transfer sheet wound on the transfer drum. Further, instead of making the transfer sheet transparent, the support sheet may be made transparent, and at least one of the transfer sheet and the support sheet may be transparent. Further, although the embodiment of the present invention applied to the electrophotographic printer for recording a continuous tone image has been described above, the adhesive transfer method of the present invention is similarly applied when recording or copying a black and white binary image. It is possible.

(Effects of the Invention) As described in detail above, according to the adhesive transfer method of the present invention, the transfer sheet is wound around the transfer drum during transfer,
Since it can be transferred only by rotating the photosensitive drum,
The transfer sheet is not stretched or distorted, and a good toner image can be transferred without cracks or the like. Further, since the transfer sheet is pulled out from the transfer sheet supply roller provided in the transfer drum and immediately taken up by the transfer drum, there is no need to attach it to the release paper for handling, and no release paper peeling means or winding means is required. Therefore, the configuration of the device can be simplified.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an adhesive transfer device for carrying out an adhesive transfer method according to an embodiment of the present invention, and FIG. 2 is an enlarged view showing the structure of a transfer drum support of the above device, FIG. 3, and FIG. 5, FIG. 7, FIG. 8, FIG. 8 and FIG. 9 are schematic views of the main part of the adhesive transfer device showing the steps of the above-mentioned embodiment, and FIG. 6 is a perspective view of a print obtained by the device. FIG. 10 is a schematic view showing a conventional adhesive transfer device. DESCRIPTION OF SYMBOLS 1 ... Transfer sheet, 1a ... Adhesive surface 3 ... Support sheet, 10 ... Photosensitive drum 11 ... Photoconductor 20 ... Toner image forming means 30,30 '... Transfer drum 31,31' ... Transfer sheet supply roller 34, 34 ' … Transfer sheet outlet 40… Heat rollers 50A, 50B… Nip rollers 51A, 51B, 52… Cutter

Claims (1)

[Claims] 1. A transfer drum having a transfer sheet supply roller formed by winding a band-shaped transfer sheet having an adhesive surface and having a transfer sheet outlet on the peripheral surface is rotated forward in a predetermined direction to form a transfer drum on the peripheral surface. The transfer sheet is wound and held with the adhesive surface facing outward, and the transfer drum is relatively moved with respect to the photosensitive drum carrying a toner image on the surface to press the photosensitive drum.
While rotating the transfer drum together with the photosensitive drum, the toner image on the photosensitive drum is transferred onto the adhesive surface of the transfer sheet, and the transfer drum is moved relative to the photosensitive drum to separate from the photosensitive drum. The transfer sheet is moved relative to the pressing roller and brought into pressure contact with the pressing roller, the transfer drum is reversed, and the transfer sheet is peeled from the transfer roller at a position where the transfer roller is pressed against the pressing roller. These sheets are attached to each other by passing the belt-shaped support sheet together with the transfer sheet, and the both attached sheets are passed between the transfer drum and the sheet conveying and holding means provided on the downstream side of the pressing roller to transfer the transfer sheet. After all the transfer sheets wound on the peripheral surface of the drum are peeled off, the transfer sheet and the support sheet attached to each other are moved forward. The transfer drum is cut at a position on the downstream side of the sheet conveying / holding means, the transfer drum is moved relative to the pressing drum and separated from the pressing drum, and the transfer sheet is held while being held by the sheet conveying / holding means. To rotate the transfer sheet in the normal direction to wind the transfer sheet around the peripheral surface of the transfer drum, cut the transfer sheet at a position between the transfer drum and the sheet conveying and holding means, and hold the end of the cut transfer sheet on the transfer drum. An adhesive transfer method characterized by: