JP2021070272A - Image forming device - Google Patents

Abstract

To suppress wrinkles caused on an ink ribbon in a wider range to prevent image defect such as pixel omission caused by wrinkles.SOLUTION: An image forming device, which transfers an image formed on a transfer medium to a recording medium using an ink ribbon, comprises: transfer means that has a platen and a thermal head comprising a heater element, which conveys the transfer medium and the ink ribbon overlapped with each other while guiding the medium and the ribbon, and transfers ink of the ink ribbon to the transfer medium to form an image, by heat generation by the heater element; and a peeling roller that peels the ink ribbon from the transfer medium, while guiding the transfer medium having the image formed thereon by the transfer means and the ink ribbon overlapped with each other with the medium and the ink ribbon wound around a surface thereof, where a plurality of groove-like concave parts are formed on the surface of the peeling roller.SELECTED DRAWING: Figure 12

Description

The present invention relates to an image forming apparatus that forms an image on a recording medium using an ink ribbon.

An image forming apparatus for forming an image on a card or the like is widely known. In such an image forming apparatus, when an indirect printing method (retransfer method) is used in which an image (mirror image) is formed on a transfer film using an ink ribbon and then the image formed on the transfer film is transferred to a card or the like. There is.

Such an image forming apparatus generally includes an image forming portion having a thermal head in which a plurality of heat generating elements are arranged and a platen roller arranged to face the thermal head. Then, while supporting the back side of the transfer film (the side opposite to the image forming surface) with a platen roller, the ink ribbon and the transfer film are conveyed at the same speed, and the heat generating element of the thermal head is pressed against the ink ribbon. An image is formed on the medium by selectively operating. After that, the ink ribbon is peeled from the transfer film by the peeling roller.

In such an image forming apparatus, color printing is often performed to generate a color image by superimposing each image with inks of a plurality of colors. In the case of color printing, a plurality of color inks (for example, Y, M, C inks) are applied to the transfer medium according to the print data (for example, print data for each Y (yellow), M (magenta), C (cyan)). ) Overlay and print each image. Therefore, in color printing, an ink ribbon having a plurality of colors of ink panels and, if necessary, a Bk (black) ink panel repeated in a surface-sequential manner is used. The Bk ink is used, for example, when clarifying the outline or when forming an image such as a logo or characters.

By the way, in an image forming apparatus using an ink ribbon, a phenomenon occurs in which the print quality on the transfer film is deteriorated due to the influence of wrinkles generated on the ink ribbon. This wrinkle is generated by the shrinkage difference between the portion heated by the thermal head and the portion not heated by the thermal head.

When the wrinkles generated on the ink ribbon reach the peeling roller, the wrinkles have no escape route and stay in place. If the ink ribbon is peeled from the transfer film on the upstream side in the transport direction from the peeling portion due to this wrinkle, the image will be peeled before the image is fixed on the transfer film, resulting in missing pixels (part of the pixels are printed). It becomes an image defect such as).

In order to suppress this wrinkle, in the image forming apparatus of Patent Document 1, when a printed image is formed on the transfer film, a heat generating element is actuated on the ink ribbon to act on the ink panel behind the transfer film of the printed image. A dummy image is formed at a position straddling the area to suppress wrinkles.

Japanese Unexamined Patent Publication No. 2016-190414

However, the image forming apparatus of Patent Document 1 does not exhibit the effect of suppressing wrinkles after the dummy image portion is peeled off, and there is a possibility that an image defect may occur particularly in the rear portion of the transfer medium. The present invention has been made to solve such a problem, and an object of the present invention is to provide an image forming apparatus capable of preventing image defects in a wider range due to wrinkles of an ink ribbon.

In order to achieve this object, the image forming apparatus of the present invention is an image forming apparatus that transfers an image formed on a transfer medium using an ink ribbon to a recording medium, and includes a platen, a thermal head including a heat generating element, and the like. The transfer medium and the ink ribbon in an overlapping state are conveyed while being guided, and the heat generating element generates heat, so that the ink of the ink ribbon is transferred to the transfer medium to produce an image. It has a transfer means to be formed, and a peeling roller for guiding the transfer medium on which an image is formed by the transfer means and the ink ribbon in an overlapping state and peeling the ink ribbon from the transfer medium. However, it is characterized in that a plurality of groove-shaped recesses are provided on the surface of the peeling roller.

When the ink ribbon is wound around the surface of the peeling roller and guided, the wrinkles generated on the ink ribbon are released to the groove-shaped recesses on the surface of the peeling roller, so that the wrinkles are suppressed and the pixels due to the wrinkles in a wider range. Image defects such as missing images can be prevented.

It is a figure which shows the structure of the printing system of embodiment of this invention. It is a figure which shows the structure of the printer of embodiment of this invention. It is a block diagram which shows the structure of the printing system of embodiment of this invention. It is a figure which shows the structure of the transfer film in embodiment of this invention. It is a figure which shows the structure of the ink ribbon in embodiment of this invention. 5 (a) is a perspective view of the entire ink ribbon, FIG. 5 (b) is a plan view of a part of the ink ribbon, and FIG. 5 (c) is a cross-sectional view of the ink ribbon. In the embodiment of the present invention, it is a figure which shows the structure of the transport mechanism of the printing part in the image formation standby state in which the pinch roller and the film transport roller are separated, and the platen roller and the thermal head are separated. It is a figure which shows the structure of the transport mechanism of the printing part in the image formation state in which the pinch roller and the film transport roller are in contact with each other, and the platen roller and the thermal head are in contact with each other in the embodiment of the present invention. It is a figure which shows the structure of the transfer mechanism of the printing part in the transfer film transfer state in which the pinch roller and the film transfer roller are in contact with each other, and the platen roller and the thermal head are separated from each other in the embodiment of the present invention. It is a figure which shows the image formation waiting state of the printing part of the embodiment of this invention. It is a figure which shows the image formation state of the printing part of the embodiment of this invention. It is a figure which shows the transfer film transport state of the printing part of the embodiment of this invention. It is a perspective view of the peeling roller of the embodiment of this invention. It is a figure which shows the periphery of the image forming part and the peeling roller of the printing part of the embodiment of this invention, and shows the state which the image is transferred to the transfer film. It is a figure which shows an example of the image formed in embodiment of this invention. It is a figure which shows the state which the wrinkle of the ink ribbon reached the peeling roller in embodiment of this invention. In the embodiment of the present invention, it is a figure which shows the state which the wrinkle of the ink ribbon is eliminated by the nip part between a peeling roller and a peeling roller. It is a perspective view which shows the peeling roller of another embodiment of this invention. It is a perspective view which shows the peeling roller of still another embodiment of this invention.

Hereinafter, an embodiment when the image forming apparatus of the present invention is applied to a printer that prints and records characters and images on a card and records magnetic or electrical information on the card will be described in detail with reference to the drawings. To do.

(System configuration)
FIG. 1 is a diagram showing a configuration of a printing system 200.

As shown in the figure, the printing system 200 has a host computer 201 and a printer 1 connected to the host computer 201. Then, the host computer 201 can transmit print data (or image data), magnetic or electrical recording data, or the like to the printer 1 to instruct the recording operation or the like. An image input device 204 such as a digital camera or a scanner, an input device 203 such as a keyboard or mouse for inputting commands or data, and a monitor 202 such as a liquid crystal display for displaying data are connected to the host computer 201. There is.

(Printer)
FIG. 2 is a diagram showing the configuration of the printer 1.

As shown in the figure, the printer 1 has a housing 2, and the information recording unit A, the printing unit B, the medium accommodating unit C, the medium accommodating unit D, and the reversing unit F are housed in the housing 2. I have.

(Information recording department)
The information recording unit A includes a magnetic recording unit 24, a non-contact IC recording unit 23, and a contact IC recording unit 27.

(Media storage)
The medium accommodating portion C can store a plurality of cards Ca (recording media) in an upright position, and is provided with a separation opening 7 at the tip thereof. Sequentially pay out and supply.

(Rotating unit)
The drawn blank card Ca is sent to the reversing unit F by the carry-in roller 22. The reversing unit F is composed of a rotating frame 80 rotatably supported by the housing 2 and two roller pairs 20 and 21 supported by the rotating frame 80. The roller pairs 20 and 21 are rotatably supported by the rotating frame 80.

The magnetic recording unit 24, the non-contact IC recording unit 23, and the contact IC recording unit 27 described above are arranged on the outer circumference around which the reversing unit F rotates. Then, the rollers 20 and 21 form a medium transport path 65 for transporting the card Ca toward any of the information recording units 23, 24, and 27, and the card Ca is magnetically formed in these recording units. Data is written either physically or electrically.

(Printing department)
The printing unit B forms an image such as a face photograph and character data on the front and back surfaces of the card Ca, and a medium transport path P1 for transporting the card Ca is provided on an extension of the medium transport path 65. Further, transport rollers 29 and 30 for transporting the card Ca are arranged in the medium transport path P1 and are connected to and driven by a transport motor (not shown).

The printing unit B has an image forming unit B1, and the image forming unit B1 forms an image with the thermal head 40 on the transfer film 46 (transfer medium) conveyed by the conveying mechanism. The printing unit B further has a transfer unit B2, and the transfer unit B2 transfers the image formed on the transfer film 46 by the image forming unit B1 to the surface of the card Ca on the medium transport path P1 by the heat roller 33. To do.

On the downstream side of the printing unit B, a medium transport path P2 for transporting the printed card Ca to the medium storage stacker 60 is provided. Transfer rollers 37, 38 for transporting the card Ca are arranged in the medium transport path P2, and are connected to and driven by a transport motor (not shown).

A decal mechanism 36 is arranged between the transfer roller 37 and the transfer roller 38, and by pressing the central portion of the card held between the transfer rollers 37 and 38, the curl generated by the thermal transfer by the heat roller 33 is corrected. Will be done. Therefore, the decal mechanism 36 is configured so that the position can be moved in the vertical direction of FIG. 2 by an elevating mechanism including a cam (not shown).

(Media storage)
The medium accommodating unit D is configured to accommodate the card Ca sent from the printing unit B in the medium accommodating stacker 60. The medium accommodating stacker 60 is configured to move downward in FIG. 2 by the elevating mechanism 61 as the card Ca is accommodating.

(Control unit)
Next, the control and electrical system of the printer 1 according to the embodiment of the present invention will be described.

FIG. 3 is a block diagram showing the configuration of the printing system 200.

As shown in the figure, the printer 1 includes a control unit 100 that controls the overall operation of the printer 1, and a power supply unit 120 that converts a commercial AC power supply into a DC power supply that can drive / operate each mechanism unit and control unit. And have.

The control unit 100 includes a microcomputer 102 (hereinafter, abbreviated as a microcomputer 102) that performs overall control processing of the printer 1. The microcomputer 102 is composed of a CPU that operates with a high-speed clock as a central processing unit, a ROM that stores a program of the printer 1 and pattern data described later, a RAM that works as a work area of the CPU, and an internal bus that connects them. ing.

An external bus 107 is connected to the microcomputer 102. The external bus 107 is connected to a buffer memory 101 that temporarily stores print data to be printed on the card Ca, magnetic stripes on the card Ca, recorded data to be recorded magnetically or electrically, and the like.

Further, the sensor control unit 103, the actuator control unit 104, the thermal head control unit 105, the operation display control unit 106, and the above-mentioned information recording unit A are connected to the external bus 107. The sensor control unit 103 controls signals from various sensors. The actuator control unit 104 supplies drive pulses and drive power to each motor. The thermal head control unit 105 controls the thermal energy to the heat generating elements constituting the thermal head 40. The operation display control unit 106 controls the operation display unit 5. The printer 1 can receive the recording operation instruction from the operation display unit 5 in addition to the recording operation instruction from the host computer 201.

(Power supply part)
The power supply unit 120 supplies operation / drive power to the control unit 100, the thermal head 40, the heat roller 33, the operation display unit 5, the information recording unit A, and the like.

(Detailed configuration of printing section)
Next, the printing unit B of the printer 1 will be described in more detail.

FIG. 4 is a diagram showing the configuration of the transfer film 46. 4A is a perspective view of the entire transfer film 46, FIG. 4B is a plan view of a part of the transfer film 46, and FIG. 4C is a cross-sectional view of the transfer film 46.

As shown in the figure, the transfer film 46 has a strip shape having a width slightly larger than the width direction of the card Ca.

The transfer film 46 is formed by laminating the ink receiving layer 461, the protective layer 462, the release layer 463, and the base film (base film) 464 in this order from the top. The ink receiving layer 461 is for receiving the ink of the ink ribbon 41. The protective layer 462 is transparent and protects the surface of the ink receiving layer 461. The peeling layer 463 is for accelerating the integral peeling of the ink receiving layer 461 and the protective layer 462 by heating.

As shown in FIG. 2, in the transfer film cassette, a take-up spool 47 is arranged at the center of the take-up roll, and a supply spool 48 is arranged at the center of the take-out roll. The rotational driving force of the motor Mr2 is transmitted to the take-up spool 47 via a gear (not shown), and the rotational driving force of the motor Mr4 is transmitted to the supply spool 48 via a gear (not shown). Then, the take-out roll and the take-up roll are rotated by driving the motors Mr2 and Mr4, and the transfer film 46 is unwound by the take-out roll and taken up by the take-up roll.

The film transfer roller 49 is a main drive roller for transferring the transfer film 46, and the transfer amount and transfer stop position of the transfer film 46 are determined by controlling the drive of the film transfer roller 49.

The film transfer roller 49 is connected to a stepping motor (not shown). By managing the number of pulses output to the stepping motor, the printing start position of the thermal head 40 in the image forming unit B1 on the transfer film 46 and the transfer position of the transfer film 46 with respect to the card Ca in the transfer unit B2 are controlled. ..

The motors Mr2 and Mr4 are also driven when the film transport roller 49 is driven, but this is a drive for feeding and winding the transfer film 46, and does not mainly transport the transfer film 46. A DC motor capable of forward and reverse rotation is used for the motor Mr2 and the motor Mr4.

A pinch roller 32a and a pinch roller 32b are arranged on the peripheral surface of the film transport roller 49. The pinch rollers 32a and 32b are configured to be movable so as to advance and retract with respect to the film conveying roller 49, and in the state of FIG. 2, the transfer film 46 is conveyed by advancing to the film conveying roller 49 and pressure-contacting. It is wrapped around a roller 49. As a result, the transfer film 46 is transported by an accurate distance according to the rotation speed of the film transport roller 49.

The ink ribbon 41, the supply spool 43 for supplying the ink ribbon 41, and the take-up spool 44 for winding the ink ribbon 41 are housed in the ink ribbon cassette 42 in a stretched state. The take-up spool 44 is rotated by the driving force of the motor Mr1, and the supply spool 43 is rotated by the driving force of the motor Mr3. A DC motor capable of forward and reverse rotation is used for the motor Mr1 and the motor Mr3.

FIG. 5 is a diagram showing the configuration of the ink ribbon 41. 5A is a perspective view of the entire ink ribbon 41, FIG. 5B is a plan view of a part of the ink ribbon 41, and FIG. 5C is a cross-sectional view of the ink ribbon 41.

The ink ribbon 41 is configured to repeat Y (yellow), M (magenta), C (cyan), and Bk (black) ink panels in a surface-sequential manner in the longitudinal direction. In this embodiment, pigment ink is used for the Y, M, and C ink panels.

That is, as shown in FIG. 5B, ink layers 411, 421, 413, and 414 corresponding to the Y, M, C, and Bk colors are repeatedly provided on the surface of the ink ribbon 41. Further, as shown in FIG. 5C, a peeling layer 415 that promotes ink peeling by controlling the heating of the thermal head 40 is provided between these ink layers and the base layer 416.

Some types of ink ribbons have Pr (primer layer) (not shown) after Bk. Further, an empty mark (not shown) indicating the usage limit of the ink ribbon 41 is attached to the end portion of the ink ribbon 41. As shown in FIG. 2, a transmissive sensor Se2 is provided to detect the empty mark.

The image forming unit B1 has a platen roller 45 and a thermal head 40, and the thermal head 40 is arranged at a position facing the platen roller 45.

The thermal head 40 has a plurality of heat generating elements arranged in a row in the main scanning direction, and these heat generating elements are selectively heated and controlled according to print data by a head control IC (not shown), and the ink ribbon 41. The ink is transferred to the transfer film 46 to form an image. At this time, the ink ribbon 41 and the transfer film 46 are conveyed at the same speed. The cooling fan 39 is for cooling the thermal head 40. The thermal head 40 and the platen roller 45 form a transfer means, and the transfer film 46 and the ink ribbon 41 in an overlapping state are guided and conveyed, and the heat generated by the heat generating element causes the ink ribbon to be transferred to the transfer film 46. The ink of the above is transferred to form an image.

The ink ribbon 41 that has been printed on the transfer film 46 is peeled off from the transfer film 46 by the peeling roller 25 and the peeling roller 28. The peeling roller 28 is fixed to the ink ribbon cassette 42, and the peeling roller 25 comes into contact with the peeling roller 28 at the time of printing and sandwiches the transfer film 46 and the ink ribbon 41 between them. The ink ribbon 41 is wound on the take-up spool 44 by the driving force of the motor Mr1, and the transfer film 46 is conveyed by the film transfer roller 49 to the transfer portion B2 having the platen roller 31 and the heat roller 33. The transfer film 46 and the ink ribbon 41 are sandwiched by the peeling roller 25 and the peeling roller 28, and then conveyed in different directions. As a result, the ink ribbon 41 is peeled off from the transfer film 46. That is, the peeling roller 28 winds the transfer film 46 and the ink ribbon 41 on which the image is formed and guides them around the surface in an overlapping state, and peels the ink ribbon 41 from the transfer film 46.

In the transfer unit B2, the transfer film 46 is sandwiched between the heat roller 33 and the platen roller 31 together with the card Ca, and the image on the transfer film 46 is transferred to the card surface. At this time, the transfer film 46 and the card Ca are conveyed at the same speed. The heat roller 33 is attached to an elevating mechanism (not shown) so as to press contact with and separate from the platen roller 31 via a transfer film 46.

(Construction of transport mechanism)
FIG. 6 shows a configuration diagram of a transport mechanism of the printing unit B in an image formation standby state in which the pinch rollers 32a and 32b, the film transport roller and 49 are separated from each other, and the platen roller 45 and the thermal head 40 are separated from each other. FIG. 7 shows a configuration diagram of a transport mechanism of the printing unit B in an image forming state in which the pinch rollers 32a and 32b and the film transport roller 49 are in contact with each other and the platen roller 45 and the thermal head 40 are in contact with each other. FIG. 8 shows a configuration diagram of a transfer mechanism of the printing unit B in a transfer film transfer state in which the pinch rollers 32a and 32b are in contact with the film transfer roller 49 and the platen roller 45 and the thermal head 40 are separated from each other.

As shown in these figures, the pinch rollers 32a and 32b are supported by the upper end and the lower end of the pinch roller support member 57, respectively, and the pinch roller support member 57 rotates to the support shaft 58 that inserts the central portion thereof. It is supported freely.

A spring member 51 is mounted on the support shaft 58, and the ends of the pinch roller support member 57 on the side where the pinch rollers 32a and 32b are mounted are in contact with the spring member 51, respectively, due to the spring force of the spring member 51. Is being urged in the direction of.

The bracket 50 is configured to be rotatable around a shaft 95 that serves as a rotation fulcrum.

The bracket 50 is in contact with the cam operating surface of the cam 53 at the cam receiver 81, and is in the direction of the arrow in FIG. 6 of the cam 53 with the cam shaft 82 rotating by the driving force of a drive motor (not shown) as a fulcrum. It is configured to move in the left-right direction in FIG. 6 in response to the rotation of the. Therefore, as shown in FIGS. 7 and 8, when the bracket 50 advances toward the film transfer roller 49, the pinch rollers 32a and 32b press against the film transfer roller 49 with the transfer film 46 sandwiched against the spring member 51. To do. As a result, the transfer film 46 is wound around the film transport roller 49.

Further, the pressure contact force when the pinch rollers 32a and 32b are pressed against the film transport roller 49 is made uniform with respect to the width direction of the transfer film 46 by the spring member 51. Further, the bracket 50 is provided with a tension receiving member 52 that comes into contact with a portion of the transfer film 46 that is not wound around the film transport roller 49 when the bracket 50 advances toward the film transport roller 49.

The tension receiving member 52 prevents the pinch rollers 32a and 32b from retracting from the film transfer roller 49 due to the tension of the transfer film 46 generated when the pinch rollers 32a and 32b press the transfer film 46 against the film transfer roller 49. It is provided for this purpose.

The bracket 50A has a substrate 87 and a cam receiving support portion 85 formed by bending in the direction of the platen support member 72 from the substrate 87, and the cam receiving supporting portion 85 holds the cam receiving portion 84. There is. A cam 53A that rotates around a cam shaft 83 driven by a drive motor (not shown) is disposed between the substrate 87 and the cam receiving support portion 85, and is provided between the cam operating surface and the cam receiving 84. Is configured to come into contact with. The platen support member 72 is rotatably configured with the shaft 71 as a fulcrum. Therefore, when the bracket 50A advances in the direction of the thermal head 40 due to the rotation of the cam 53A, the platen support member 72 also moves and the platen roller 45 presses against the thermal head 40. The platen roller 45 is rotatably provided around the platen roller shaft 96.

When the platen roller 45 is pressed against the thermal head 40, the spring member 99 connected to the platen support member 72 acts so that the pressure contact force in the width direction of the transfer film 46 becomes uniform. Therefore, skew is prevented when the transfer film 46 is conveyed by the film conveying roller 49.

A pair of release roller support members 88 that support both ends of the release roller 25 are provided on the substrate 87 of the bracket 50A via a spring member 97. When the bracket 50A advances to the thermal head 40 by the rotation of the cam 53A, the peeling roller 25 comes into contact with the peeling roller 28 and peels the transfer film 46 and the ink ribbon 41 sandwiched between the two. The peeling roller support members 88 are provided at both ends of the peeling roller 25, respectively, and are configured so that the pressure contact force in the width direction with respect to the peeling roller 28 becomes uniform.

A tension receiving member 52A is provided at an end of the bracket 50A opposite to the end on the shaft 71 side. The tension receiving member 52A is provided so as to absorb the tension of the transfer film 46 generated when the platen roller 45 and the peeling roller 25 are pressed against the thermal head 40 and the peeling roller 28, respectively. The spring member 99 and the spring member 97 are provided to make the pressure contact force of the transfer film 46 in the width direction uniform. However, on the contrary, the tension receiving member 52A receives the tension from the transfer film 46 so that the spring members 99 and 97 do not lose the tension of the transfer film 46 and the pressure contact force with the transfer film 46 is weakened.

Since the tension receiving member 52A is also fixed to the bracket 50A like the above-mentioned tension receiving member 52, the tension of the transfer film 46 is received by the cam 53A via the bracket 50A, so that the tension of the transfer film 46 is received. I will not lose to. As a result, the pressure contact force between the thermal head 40 and the platen roller 45 and the pressure contact force between the peeling roller 28 and the peeling roller 25 are maintained, so that good image formation and peeling can be performed. Further, when the film transport roller 49 is driven, the transfer amount of the transfer film 46 does not cause an error, and the length of the image forming region is accurately transferred to the thermal head 40 with high accuracy (without causing color shift). Images can be formed.

A belt 98 is stretched between the cam 53 and the cam 53A, and they are driven by the same drive motor (not shown).

The thermal head 40 is arranged at a position facing the platen roller 45 with the transfer path of the transfer film 46 and the ink ribbon 41 interposed therebetween.

9 is a diagram showing an image formation standby state of the printing unit B, FIG. 10 is a diagram showing an image forming state of the printing unit B, and FIG. 11 is a diagram showing a transfer film conveying state of the printing unit B.

When the printing unit B is in the standby position shown in FIG. 9, the cam 53 and the cam 53A are in the state shown in FIG. 6, the pinch rollers 32a and 32b are not pressed against the film transport roller 49, and the platen roller 45 is the thermal head 40. Not pressed against. That is, when in the standby position, the platen roller 45 and the thermal head 40 are located at separate positions where they are separated from each other.

Then, when the cam 53 and the cam 53A rotate in conjunction with each other to reach the state shown in FIG. 7, the printing unit B shifts to the image forming position shown in FIG. At that time, first, the pinch rollers 32a and 32b wind the transfer film 46 around the film transport roller 49, and the tension receiving member 52 comes into contact with the transfer film 46. After that, the platen roller 45 is pressed against the thermal head 40. In this printing position, the platen roller 45 moves toward the thermal head 40 to sandwich and press-contact the transfer film 46 and the ink ribbon 41, and the peeling roller 25 is in contact with the peeling roller 28.

In this state, when the transfer film 46 is started by the rotation of the film transfer roller 49, the ink ribbon 41 is also wound by the take-up spool 44 by the operation of the motor Mr1 and conveyed in the same direction. During this transfer, the mark formed on the transfer film 46 passes through the sensor Se1 and moves a predetermined distance, and when the transfer film 46 reaches the image formation start position, the thermal head 40 reaches the image formation region of the transfer film 46. Image formation is performed by. In particular, the tension of the transfer film 46 increases during image formation. Therefore, the tension of the transfer film 46 acts in the direction of separating the pinch rollers 32a and 32b from the film transport roller 49 and in the direction of separating the release roller 25 and the platen roller 45 from the release roller 28 and the thermal head 40. However, as described above, since the tension of the transfer film 46 is received by the tension receiving members 52 and 52A, the pressure contact force of the pinch rollers 32a and 32b is not weakened, and accurate film transfer can be performed. Since the pressure contact force between the thermal head 40 and the platen roller 45 and the pressure contact force between the peeling roller 28 and the peeling roller 25 are not weakened, accurate image formation (printing) and peeling can be performed.

Next, when the cam 53 and the cam 53A are further rotated in conjunction with each other to reach the state shown in FIG. 8, the printing unit B shifts to the transport position shown in FIG. 11, and the platen roller 45 returns to the direction of retracting from the thermal head 40. .. In this state, the pinch rollers 32a and 32b still wind the transfer film 46 around the film transport roller 49, and the tension receiving member 52 is in contact with the transfer film 46. Then, the transfer film 46 is reverse-transported to the initial position by the reverse rotation of the film transport roller 49. At this time as well, the amount of movement of the transfer film 46 is controlled by the rotation of the film transport roller 49, but the length of the image forming region in which the image is formed by the one-color ink panel (for example, Y) is reversely transported. Will be done. The ink ribbon 41 is also rewound by a predetermined amount by the motor Mr3, and then the ink panel of the ink for forming an image is made to stand by at the initial position (cueing position).

Then, the cams 53 and 53A are in the state shown in FIG. 7 again, and the printing unit B is in the image forming position shown in FIG. Then, the platen roller 45 is pressed against the thermal head 40, the film transport roller 49 rotates in the positive direction again to move the transfer film 46 by the length of the image forming region, and the thermal head 40 causes the next ink panel. Image formation is performed with the ink of.

In this way, the operations at the image forming position and the conveying position are repeated until all or the image formation by the ink of the predetermined ink panel is completed. Then, when the image formation by the thermal head 40 is completed, the image forming region of the transfer film 46 is conveyed to the heat roller 33. At this time, the cams 53 and 53A move to the state shown in FIG. 6 and are pressed against the transfer film 46. To cancel. After that, the transfer film 46 is transferred to the card Ca while being driven by the film transfer motor (not shown), the motor Mr2, and the motor Mr4.

(Detailed configuration of peeling roller)
FIG. 12 is a perspective view of the peeling roller 28.

As shown in the figure, a plurality of recesses 281 are provided on the surface of the peeling roller 28 in a direction parallel to the axial direction of the central axis 285 of the peeling roller 28.

FIG. 13 is a diagram showing the periphery of the image forming unit B1 of the printing unit B and the peeling roller 28, and shows a state in which the image is transferred to the transfer film 46.

As shown in the figure, in the image forming portion B1, the platen roller 45 moves toward the thermal head 40, sandwiches and press-contacts the transfer film 46 and the ink ribbon 41, and the peeling roller 25 is in contact with the peeling roller 28. .. In this state, when the transfer film 46 is started by the rotation of the film transfer roller 49, the ink ribbon 41 is also wound while being guided by the ribbon guide roller 155 by the take-up spool 44 by the rotation of the motor Mr1 at the same time. Transported in the direction. Then, the image transfer is started by energizing the heat generating element of the thermal head 40.

At this time, as shown in FIG. 13, wrinkles Wr may occur on the ink ribbon 41.

FIG. 14 is a diagram showing an example of the formed image.

In the image shown in the figure, as shown in FIG. 13, wrinkles Wr are generated in the non-printing portion 902 on the ink ribbon 41 by heating the printing portion 900 and the printing portion 901 by the thermal head 40. there is a possibility. That is, wrinkles Wr are generated due to the shrinkage difference between the portion heated by the thermal head 40 and the portion not heated, and generally tend to occur near the boundary between the imprinted portion and the non-printed portion. In particular, in an image having a shape as shown in FIG. 14, when wrinkles Wr are generated in the non-printing portion 902, the wrinkle Wr by the printing portion 900 and the wrinkle Wr by the printing portion 901 may be aggregated and become large. ..

FIG. 15 is a diagram showing a state in which the wrinkle Wr of the ink ribbon 41 reaches the peeling roller 28.

As shown in the figure, when the wrinkle Wr of the ink ribbon 41 reaches the nip portion between the peeling roller 25 and the peeling roller 28, the wrinkle Wr is conventionally pressed against the peeling roller having a flat surface, and the wrinkle Wr is formed. There was a possibility that there would be no escape. Conventionally, while the wrinkle Wr is large, the wrinkle Wr is folded and fixed, and the ink ribbon 41 is peeled off by the fixed wrinkle Wr. There was a possibility that the image would be peeled off before it was fixed. This peeling of the image has been a cause of image defects such as missing pixels (a part of the pixels is not printed).

FIG. 16 is a diagram showing a state in which the wrinkles Wr of the ink ribbon 41 are eliminated at the nip portion between the peeling roller 25 and the peeling roller 28.

In the present embodiment, when the wrinkle Wr reaches the peeling roller 28, the wrinkle Wr is released by the recess 281 provided in the peeling roller 28, so that the wrinkle Wr disappears or becomes smaller from the ink ribbon 41. Peeling can be prevented or suppressed.

FIG. 17 is a perspective view showing a peeling roller 28a of another embodiment.

Unlike the embodiment shown in FIG. 12, the peeling roller 28a has a recess 281a along the circumferential direction (along the circumference where the plane orthogonal to the central axis 285a of the peeling roller 28a and the peripheral surface of the peeling roller 28a intersect). Is provided.

FIG. 18 is a perspective view showing a peeling roller 28b of still another embodiment.

Unlike the embodiment shown in FIG. 12, the peeling roller 28b is provided with a spiral recess 281b on the surface of the peeling roller 28b. That is, the recess 281b is formed in a groove shape, and has a groove-shaped portion along the direction of the central axis 285b of the peeling roller 28b or the direction inclined from the circumferential direction of the peeling roller 28b.

By configuring the recess 281b in this way, the wrinkles Wr that escaped to the recess 281b as the peeling roller 28b rotates are gradually removed by the peripheral surface portion 282b between the recess 281b and the recess 281b in the direction parallel to the central axis 285b. It is possible to extrude to. With such a configuration, the wrinkle Wr can be further reduced.

The plurality of groove-shaped recesses 281a of the peeling roller 28a shown in FIG. 17 were tilted from the axial direction of the peeling roller 28a or the circumferential direction of the peeling roller 28a, instead of forming the recesses into one spiral groove. It may be provided along the direction.

Further, the concave portion on the surface of the peeling roller 28 may be provided by secondary processing, or may be processed into a knurled shape (fine uneven shape).

1 ... Printer 25 ... Peeling roller 28, 28a, 28b ... Peeling roller 31 ... Secondary transfer platen roller 33 ... Heat roller 41 ... Ink ribbon 45 ... Primary transfer platen roller 46 ... Transfer film 49 ... Conveying roller 281, 281a, 281b ... Groove 282b ... Peripheral surface Ca ... Card

Claims (5)

An image forming apparatus that retransfers an image formed on a transfer medium using an ink ribbon to a recording medium.
It has a platen and a thermal head provided with a heat generating element, and conveys the transfer medium and the ink ribbon in an overlapping state while guiding them, and the heat generating element generates heat to the transfer medium. A transfer means for forming an image by transferring the ink of the ink ribbon,
A peeling roller that winds the transfer medium on which an image is formed by the transfer means and the ink ribbon on a surface to guide the ink ribbon and peels the ink ribbon from the transfer medium.
Have,
An image forming apparatus characterized in that a plurality of groove-shaped recesses are provided on the surface of the peeling roller. The image forming apparatus according to claim 1, wherein each of the groove-shaped recesses is provided along the direction of the central axis of the peeling roller. The image forming apparatus according to claim 1, wherein each of the groove-shaped recesses is provided along the circumferential direction of the peeling roller. The image forming apparatus according to claim 1, wherein the recess has a groove-like portion along the direction of the central axis of the peeling roller or the direction inclined from the circumferential direction of the peeling roller. The image forming apparatus according to claim 4, wherein the recess is spirally provided on the surface of the peeling roller.

Images