JP3350905B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer roller in an image forming apparatus for transferring an image written on an intermediate transfer medium to a transfer object by heating and pressing the image onto the transfer object.
More specifically, when transferring the image of the intermediate transfer medium to the transfer receiving body, to prevent wrinkles from being formed on the intermediate transfer medium,
Regarding a transfer roller that enables clear transfer of images,
Further, the present invention relates to a transfer roller capable of selectively transferring only a portion to be transferred of an image on an intermediate transfer medium to a transfer target.

[0002]

2. Description of the Related Art A method of using a transfer ribbon coated with a sublimable dye uniformly over the entire surface, selectively heating a local portion by a thermal head based on image data, and transferring and forming a desired image on a transfer object is known. is there. However, the material that can be dyed with the sublimable material is limited, and is applicable only to a transfer target of a limited material such as, for example, polyester, acrylic resin, and polyvinyl chloride. However, in addition to the above synthetic resin,
In general, synthetic resins, paper,
There are various materials such as metal and glass.

Therefore, as disclosed in JP-A-63-81093, a film-like intermediate transfer medium having an adhesive layer is first used in an image writing section using a transfer ribbon of a sublimable dye and a thermal head. A method of transferring an image onto an object to be transferred by heating and pressing the image on the intermediate transfer medium with the adhesive layer on the object to be transferred together with the adhesive layer using a transfer roller in a transfer unit. I have. According to this method, by selecting the adhesive layer, it is possible to transfer and form an image regardless of the material of the transfer target.

[0004]

However, in this method, since a thin film-like intermediate transfer medium having a predetermined width is used, an image on the intermediate transfer medium is heated and pressed by a transfer roller onto a transfer-receiving body. In this case, there is a problem that wrinkles are easily formed on the intermediate transfer medium, and the quality of the image transferred to the transfer receiving body is deteriorated. Then, once the wrinkles are formed in the transfer unit, the intermediate transfer medium is continuously stretched from the image writing unit to the transfer unit, so that the wrinkles extend not only to the transfer unit but also to the image writing unit on the upstream side, Thereafter, continuous image transfer cannot be performed.

The present invention has been devised in view of the above circumstances, and an object of the present invention is to generate wrinkles in an intermediate transfer medium when an image formed on the intermediate transfer medium is transferred to a medium to be transferred. An object of the present invention is to provide a transfer roller in an image forming apparatus capable of preventing the occurrence of an image and clearly transferring an image. It is another object of the present invention to provide a transfer roller capable of selectively transferring only a portion to be transferred of an image on an intermediate transfer medium to a transfer target.

[0006]

According to the present invention, an image is written on one side of a film-like intermediate transfer medium on the basis of image information, and the surface of the intermediate transfer medium on which the image is written is provided. Wherein the image is transferred from the intermediate transfer medium to the transfer target by heating and pressing with a transfer roller from a surface opposite to the surface on which the image is written, with the transfer facing the transfer target. As a roller, an outer peripheral surface portion that heats and presses the intermediate transfer medium,
It is characterized in that a transfer roller whose central part in the axial direction is formed by a concave surface having a diameter smaller than both ends thereof, and the concave surface is coated with a fluoropolymer compound is used.

Further, the present invention comprises a roller main body in which the transfer roller has a cylindrical shape, and a halogen lamp heater disposed inside the roller main body, wherein an inner peripheral surface of the roller main body is blackened. It is characterized by having. Further, the present invention is characterized in that the fluorine-based polymer compound is polytetrafluoroethylene. Also, the present invention
The fluoropolymer compound is a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether. Further, the present invention is characterized in that the fluorine-based polymer compound is provided with conductivity by mixing a conductive filler. Also, the present invention provides an image forming apparatus, wherein the outer peripheral surface of the transfer roller is depressed from the contact surface at a position different from the contact surface in a circumferential direction, the contact surface being heated and pressurized in contact with the intermediate transfer medium. And a non-contact surface that does not contact the surface. Further, the present invention writes an image on one side of a film-like intermediate transfer medium based on image information, and directs the surface of the intermediate transfer medium on which the image is written to a transfer target body on the surface on which the image is written. In an image forming apparatus in which the image is transferred from the intermediate transfer medium to the transfer target by applying heat and pressure with a transfer roller from the opposite surface, an outer peripheral surface of the transfer roller contacts the intermediate transfer medium. A transfer roller having a non-contact surface which is depressed from the contact surface at a position different from the contact surface in the circumferential direction and does not contact the intermediate transfer medium.

[0008]

When transferring an image, the transfer roller smoothly rotates on the intermediate transfer medium to heat and press the intermediate transfer medium. At this time, a force is applied to the intermediate transfer medium so as to spread in the width direction.
Wrinkles are less likely to occur on the intermediate transfer medium, and the image is clearly transferred from the intermediate transfer medium to the subject. Further, only the portion of the image on the intermediate transfer medium that is desired to be transferred is selectively transferred to the transfer target by the contact surface and the non-contact surface.

[0009]

An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an external perspective view of the image forming apparatus. In FIG. 1, reference numeral 1 denotes an image forming apparatus, 3 denotes an apparatus main body, 5 denotes a pull-out transfer stage, and the transfer stage 5 is slidably provided on the apparatus main body 3. Transfer stage 5
In the illustrated example, a card 7 mainly composed of a synthetic resin material and a booklet 9 mainly composed of paper are installed. More specifically, the recesses 11 and 1 are provided so that the card 7 and the booklet 9 are almost half filled according to the shape and thickness of the card 7 and the booklet 9.
3 is formed on the transfer stage 5. Although the thicknesses of the card 7 and the booklet 9 are different from each other, the height of the transfer surface can be appropriately set by adjusting the depths of the concave portions 11 and 13. In the booklet 9, fixing devices 15 may be provided at four corners in order to keep a page corresponding to the transfer surface open. Switches 17 such as an ON / OFF switch, a card switch C, and a booklet switch S are provided on an operation unit of the apparatus body.
Is provided.

FIG. 2 is a front view of the image forming apparatus. The apparatus main body 3 includes an image writing unit 29 that forms a color image on the intermediate transfer medium 27 on the rotating drum 25 by the thermal head 21 and the transfer ribbon 23, and transfers the color image written on the intermediate transfer medium 27 to the card 7 by the transfer roller 31. And a transfer unit 33 for transferring the image to a transfer target such as a booklet 9 by heating and pressing.

The transfer ribbon 23 is composed of a substrate tape and a thermal transfer material layer formed on the substrate tape. As the thermal transfer material, in addition to sublimable dyes such as anthraquinone, azo and naphthoquinone dyes, A wax-based thermal transfer material containing a binder such as paraffin wax and carnauba wax and a pigment and / or a dye can be used. Such pigments and dyes are not particularly limited, and examples thereof include carbon black, crystal violet, Kayaset Blue, and methylene blue. In the embodiment, the transfer ribbon 23 is individually coated with magenta, yellow, cyan, and black paints for each predetermined area, and is passed from the supply reel 2301 to the take-up reel 23 through the head of the thermal head 21.
It is wound around 03.

The intermediate transfer medium 27 is formed of a transparent film, and an adhesive layer is formed on a surface on which an image is written by the thermal head 21 and the transfer ribbon 23. The intermediate transfer medium 27 is wound around the take-up reel 2703 after being wound around the image writing unit 29 and the transfer unit 33 from the supply reel 2701.

The intermediate transfer medium 27 fed from the supply reel 2701 receives an upstream guide roller group 2705, an upstream tension roller 2707, and an upstream contact roller 2709.
Is wound around the rotating drum 25. The intermediate transfer medium 27 wound around the rotating drum 25 is connected to a downstream contact roller 27.
11, downstream guide roller group 2713, downstream tension roller 2715, upper roller 2717, lower roller 2719
Is transferred to the transfer unit 33 via the lower roller 2721 from the transfer unit 33, and is taken up by the take-up reel 2703.

In the image writing section 29, the rotating drum 25
With the intermediate transfer medium 27 wound and fixed around
The rotary drum 25 is reciprocated four times, and a single-color image of each of magenta, yellow, cyan, and black paints is sequentially formed on the intermediate transfer medium 27 by the thermal head 21 to form a color image.

The transfer section 33 is provided on a moving frame 35 which reciprocates linearly with respect to the frame 301 of the apparatus main body 3. The transfer section 33 is provided on the card 7 corresponding to the two transfer objects of the card 7 and the booklet 9. Transfer section 33A and a booklet transfer section 33B. Further, a transfer roller 31 is provided corresponding to each transfer unit 33,
That is, the card transfer section 33A is provided with a card transfer roller 31A, and the booklet transfer section 33B is provided with a booklet transfer roller 31B. Further, pressing rollers 36 are disposed before and after each transfer roller 31, respectively, and a guide roller 37 is disposed in front of the pressing roller 36 in front of each transfer roller 31, and a pressing roller behind each transfer roller 31 is provided. A peeling roller 39 is provided behind 36. Each of the transfer rollers 31 is arranged so as to be able to swing up and down between an upper retreat position and a lower transfer position, and is configured to rotate via a gear mechanism 40 when the moving frame 35 moves. Have been.

The color image formed by the image writing unit 29 is transferred to the transfer unit 33, and the transfer of the intermediate transfer medium 27 is stopped at a position where the color image faces a predetermined position on the transfer object. Then, in response to the operation of the card switch C or the booklet switch S, one or both of the card transfer roller 31A and the booklet transfer roller 31B are swung from the retracted position to the transfer position and swung to the transfer position. Transfer roller 3
The first and second pressing rollers 36 press the intermediate transfer medium 27 on the transfer stage 5. Then, the transfer roller 31 linearly moves while rotating by the movement of the moving frame 35, and the color image of the intermediate transfer medium 27 is heated and pressed by the transfer roller 31 to the transfer receiving body, and the color image is transferred to the card 7, the booklet 9 or the like. The image is transferred to the transfer target.

The card transfer roller 31A has a tubular card roller main body 41 as shown in a sectional side view in FIG. 3 and a front view in FIG.
1B is provided with a cylindrical roller body 43 in the same manner as described above, as shown in a sectional side view in FIG. 5 and a front view in FIG. 6, and inside each roller body 41, 43 is indicated by a virtual line. In addition, a halogen lamp heater 45 for heating the intermediate transfer medium is provided, and each of the roller main bodies 41 and 43 is rotatably supported at both ends by a cylindrical support member. The halogen lamp heater 45 is mounted on the support member. It is worn and arranged.

The material of the roller bodies 41 and 43 is not particularly limited as long as it has appropriate rigidity. For example, metals such as stainless steel, aluminum and brass, resins such as polycarbonate, polyacetal and polyamide, alumina and the like. Ceramics and the like can be mentioned.

In the present embodiment, the entire inner surface of the roller main bodies 41 and 43 is blackened.
This is performed by a method of applying a black paint on the inner peripheral surface or the like. Since heat resistance is required as such a paint, for example, a silicone resin-based paint is used. The inner peripheral surfaces of the roller main bodies 41 and 43 are blackened so that the roller main bodies 41 and 43 heated by the halogen lamp heater 45 are processed.
43 prevents the halogen lamp heater 45 from being reheated and damaged due to the heat radiation of the roller body 43.
Heat unevenness in 1, 43 can be eliminated. Therefore, the image quality of the image can be improved by uniformly heating the image area of the intermediate transfer medium 27 over the whole by the roller main bodies 41 and 43. In addition, uneven heating may cause wrinkles of the intermediate transfer medium 27. Therefore, eliminating uneven heating is advantageous in preventing wrinkles from being generated in the intermediate transfer medium 27.

Small-diameter surfaces 41A and 43A (corresponding to non-contact surfaces) formed in a cylindrical shape with a small radius so as not to contact the intermediate transfer medium 27 are provided on the outer peripheral portions of the roller bodies 41 and 43, respectively. Pressing surfaces 41B and 43B formed in a cylindrical shape with a large radius corresponding to the area of the image to be transferred
(Corresponding to a contact surface), and the small-diameter surface 41A and the pressing surface 41B are formed at different positions in the circumferential direction of the outer peripheral portion of the roller body 41 as shown in FIG. As shown in FIG. 6, the pressing surface 43 </ b> B and the pressing surface 43 </ b> B are formed at different positions in the circumferential direction of the outer peripheral portion of the roller main body 43. The pressing surfaces 41B and 43B are portions for heating and pressing the intermediate transfer medium 27, and include the width W1 and the length L1 of the pressing surfaces 41B and 43B of the card transfer roller 31A, and the pressing surfaces 41B and 43B of the booklet transfer roller 31B. The width W2 and length L2 of 43B are formed so as to match the width and length of the color image to be transferred, respectively.

The pressing surfaces 41B and 43B are provided in
As shown in the figure, the central portion C in the axial direction of the roller main bodies 41 and 43 is formed with an outer diameter smaller than both ends E, and the central portion C
To the two ends E, the outer diameter gradually increases.

Further, in order to improve the sliding with respect to the intermediate transfer medium 27, the surfaces of the pressing surfaces 41B and 43B are formed as shown in FIG.
As shown in (1), it is covered with a coating layer 47, and this coating layer 47 is made of a fluorine-based polymer compound. Specific examples of the fluorine-based polymer compound include polytetrafluoroethylene (PTFE) and a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether.

The coating layer 47 may be made conductive by adding a conductive filler to the resin material. The conductive filler may be made of a nonmetallic conductive material such as carbon. Examples of the filler include metal conductive fillers such as Sn-based and Ag-based fillers. When the coating layer 47 is made conductive, the intermediate transfer medium 27 is prevented from adhering to the transfer roller 31 due to static electricity. Such a coating layer 47 is usually 2 to 100 μm, preferably 3 to 2 μm.
It has a thickness of 5 μm. The coating layer 47 is formed by powder coating, molding, electroless plating, tube coating, or the like.

According to the transfer roller 31 according to the present embodiment,
The pressing surfaces 41B and 43B are formed such that the central portion C in the axial direction of the transfer roller 31 is a concave surface having an outer diameter smaller than both ends E, and the pressing surfaces 41B and 43B are made of a fluoropolymer compound. Because it is covered with the covering layer 47,
The pressing surfaces 41B and 43B smoothly rotate on the intermediate transfer medium 27 to heat and press the image area, and the concave surface applies a force to expand the intermediate transfer medium 27 in the width direction.
The generation of wrinkles on the intermediate transfer medium 27 is effectively prevented, and the color image is clearly transferred from the intermediate transfer medium 27 to the subject.

Further, since the coating layer 47 is excellent in heat resistance and has a small coefficient of friction, it can press the intermediate transfer medium 27 with good adhesion by the pressing surfaces 41B and 43B. An air gap does not occur between the intermediate transfer medium 27 and the surfaces of the pressing surfaces 41B and 43B due to dirt attached to the surface, which is more advantageous in clearly transferring an image.

Further, pressing surfaces 41B and 43B for heating and pressing the intermediate transfer medium 27 and small-diameter surfaces 41A and 43A not in contact with the intermediate transfer medium 27 are formed on the outer peripheral surface of the transfer roller 31, so that the intermediate transfer medium 27 is formed. Of the above image information, only the portion to be transferred can be selectively transferred to the transfer target, and at this time, particularly, the edge of the image transferred to the transfer target can be sharpened clearly.

In the embodiment, the case where the inner peripheral surfaces of the roller main bodies 41 and 43 are subjected to the blackening processing has been described, but the material of the roller main bodies 41 and 43 or the roller main bodies 41 and 43 is used.
Depending on the ratio of the inner peripheral surface area to the outer peripheral surface area of the halogen lamp heater 45, the blackening process may be omitted.

[0028]

As is apparent from the above description, according to the present invention, at the time of image transfer, the transfer roller smoothly rotates on the intermediate transfer medium to heat and press the intermediate transfer medium. Is applied with a force that spreads in the width direction, so that wrinkles are prevented from being generated on the intermediate transfer medium, and clear transfer of an image from the intermediate transfer medium to a subject becomes possible. Also,
According to the present invention, since the contact surface and the non-contact surface are provided on the outer peripheral surface of the transfer roller, only the portion of the image information on the intermediate transfer medium that is desired to be transferred can be selectively transferred to the transfer target.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an image forming apparatus.

FIG. 2 is a front view of the image forming apparatus.

FIG. 3 is a cross-sectional side view of a card roller main body.

FIG. 4 is a front view of a card roller main body.

FIG. 5 is a sectional side view of a booklet roller main body.

FIG. 6 is a front view of a booklet roller main body.

FIG. 7 is an explanatory diagram of a pressing surface.

FIG. 8 is an enlarged sectional view of a main part of a pressing surface.

[Explanation of symbols]

 Reference Signs List 21 thermal head 27 intermediate transfer medium 29 writing unit 31A card transfer roller 31B booklet transfer roller 33 transfer unit 41B, 43B pressing surface 47 coating layer

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-34336 (JP, A) JP-A-1-195479 (JP, A) JP-A-59-113470 (JP, A) JP-A-60-1985 263979 (JP, A) Japanese Utility Model sho 59-166936 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41F 16/00

Claims (7)

(57) [Claims] An image is written on one side of a film-like intermediate transfer medium based on image information, and the surface of the intermediate transfer medium on which the image is written is directed toward a transfer object, and the opposite side of the surface on which the image is written. An image forming apparatus in which the image is transferred from the intermediate transfer medium to the transfer target by heating and pressing with a transfer roller from the side surface, wherein as the transfer roller, an outer peripheral surface portion for heating and pressing the intermediate transfer medium is provided. Using a transfer roller whose central portion in the axial direction is formed with a concave surface having a diameter smaller than both ends thereof, and further, the concave surface is coated with a fluorine-based polymer compound. apparatus. 2. The transfer roller according to claim 1, further comprising: a cylindrical roller body; and a halogen lamp heater disposed inside the roller body, wherein an inner peripheral surface of the roller body is blackened. The image forming apparatus according to claim 1, wherein: 3. The image forming apparatus according to claim 1, wherein said fluorine-based polymer compound is polytetrafluoroethylene. 4. The fluoropolymer compound according to claim 1, wherein the fluoropolymer compound is a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether.
The image forming apparatus as described in the above. 5. The image forming apparatus according to claim 1, wherein the fluorine-based polymer compound is provided with conductivity by mixing a conductive filler. . 6. An outer peripheral surface of the transfer roller, which is in contact with the intermediate transfer medium and is heated and pressurized, and is depressed from the contact surface at a position different from the contact surface in a circumferential direction to the intermediate transfer medium. The image forming apparatus according to claim 1, further comprising a non-contact surface that does not make contact. 7. An image is written on one side of a film-like intermediate transfer medium on the basis of image information, and the surface of the intermediate transfer medium on which the image is written is directed toward an object to be transferred and opposite to the surface on which the image is written. An image forming apparatus that transfers the image from the intermediate transfer medium to the transfer target by heating and pressing with a transfer roller from the side surface, wherein the outer peripheral surface of the transfer roller contacts the intermediate transfer medium. Using a transfer roller having a contact surface to be heated and pressurized, and a non-contact surface that is recessed from the contact surface at a location different from the contact surface in a circumferential direction and does not contact the intermediate transfer medium. apparatus.