JP2005238668A - Intermediate transfer type thermal transfer printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intermediate transfer type thermal transfer printer capable of realizing a long life of a component in a simple structure and sufficiently suppressing occurrence of flicker. <P>SOLUTION: In this intermediate transfer type thermal transfer printer 1, a film F having an image transferred thereon is heated to be pressed against a card S by means of a heat roller 23, and then the image on the film F is retransferred to the card S. The intermediate transfer type thermal transfer printer 1 comprises a heating element 25 which is provided in the heat roller 23 and has a filament 26 to be energized by being electrically connected to an external power source 28, a switching means 32 for turning on or off the current to the heating element 25 from the external power source 28, and a thermally sensitive resistor element 30 which is serially connected across a terminal 34 of the heating element 25 and a terminal 35 of the external power source 28 and has a characteristic that the electric resistance is decreased as the rising of the temperature due to the self current. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an intermediate transfer type thermal transfer printing apparatus for transferring a printed image once onto a film and then transferring the image on the film onto the surface of a recording medium.

Conventionally, as a technique in such a field, there is a card recording device for printing a desired image on the surface of a card with a magnetic stripe, an IC card or the like. In this card recording apparatus, after the film onto which the image has been transferred and the recording medium such as a card are simultaneously conveyed, both are pressed and heated between the heat roller and the pressing roller, whereby the image on the film is Re-transferred onto the card.
Japanese Patent Laid-Open No. 7-114990

  The heat roller in such an apparatus incorporates a heat generating element such as a halogen lamp, and the surface of the heat roller is heated by connecting the heat generating element to an external power source. Furthermore, in order to keep the surface temperature of the heat roller in a range suitable for transfer, the connection between the heating element and the power supply terminal is repeatedly turned on / off.

  However, in the configuration described above, an inrush current is generated when the halogen lamp is turned on, and this inrush current shortens the life of the halogen lamp or has an adverse effect such as flicker on indoor lighting equipment connected to the same power distribution system. There is a tendency. This flicker is caused by a sudden change in current due to an inrush current. In order to prevent such an effect, there is a method of selecting a halogen lamp having an electric strength capable of withstanding an inrush current. However, it is difficult to efficiently cope with a power supply voltage which varies depending on a use region, and flicker. It is also impossible to suppress the occurrence of.

  On the other hand, there is a halogen lamp dimmer described in Patent Document 1 as a technique for dealing with a power supply voltage that varies depending on the area of use. This halogen lamp dimming device operates to apply a power supply voltage in a predetermined electrical angle range to a halogen lamp by an FET connected to the AC power supply side and a control circuit for the FET. However, the control circuit has a complicated configuration including many kinds of elements such as a diode and an operational amplifier, which leads to an increase in the cost of the apparatus.

  Accordingly, the present invention has been made in view of the above problems, and provides an intermediate transfer type thermal transfer printing apparatus that can realize a long service life of components with a simple configuration and can sufficiently suppress the occurrence of flicker. The purpose is to do.

  The intermediate transfer type thermal transfer printing apparatus of the present invention is an intermediate transfer type thermal transfer printer that re-transfers an image on a film to the surface of the recording medium by pressing the film onto which the image has been transferred against the recording medium while being heated by a heat roller. In the printing apparatus, a heating element installed in the heat roller and having a filament that is energized by being electrically connected to an external power source, and a switching unit that alternately turns on and off the energization of the heating element from the external power source, A temperature-sensitive resistance element connected in series between one end of the heat generating element and a connection terminal of an external power source, and having a characteristic that electric resistance decreases as the temperature rises due to self-energization. And

  In such an intermediate transfer type thermal transfer printing apparatus, the heat roller is heated to a desired temperature by alternately energizing the heat generating element from an external power source. Immediately after switching the energization to the heating element, the resistance value of the heating element is relatively small due to the low temperature state of the filament. At the same time, the resistance value of the temperature sensitive resistance element connected in series with the heating element is sufficiently large due to its own low temperature state. This effectively prevents inrush current from occurring in the heating element immediately after energization is turned on.

  In addition, it is preferable to further include a conductive portion that is connected in parallel to the temperature-sensitive resistance element and is configured to bypass the temperature-sensitive resistance element to energize the heating element, and a switch portion that opens and closes the conductive portion. When such a conductive part and a switch part are provided, when the voltage of the external power supply to be used is relatively small, both ends of the temperature-sensitive resistance element are electrically short-circuited by the conductive part to ensure a voltage applied to the heating element. Therefore, insufficient heating of the heat roller can be avoided.

  Furthermore, it is preferable that the temperature-sensitive resistance element is a power thermistor and the heating element is a halogen lamp. If a power thermistor is used, the temperature sensitivity is high and the occurrence of inrush current is more reliably prevented. Furthermore, since the halogen lamp has high responsiveness, the temperature control of the heat roller can be easily realized.

  According to the intermediate transfer type thermal transfer printing apparatus of the present invention, the life of parts can be extended with a simple configuration, and the occurrence of flicker can be sufficiently suppressed.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of an intermediate transfer type thermal transfer printing apparatus according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the intermediate transfer type thermal transfer printing apparatus 1 is also called a card printer, and once a printed image is transferred to a transparent film F having a thickness of about 20 μm, the recording medium (for example, plastic) is transferred from the film F. (Transfer cash card, credit card, prepaid card, IC card, etc.). Such a thermal transfer printing apparatus 1 is used when issuing the card S, and can print a high-quality image on the surface of the card S. Therefore, it is possible to issue a card S containing a face photo for the purpose of improving security.

  Such an intermediate transfer type thermal transfer printing apparatus 1 has a stock unit 2 for setting a plastic card S to be printed in a stacked state. The cards S are fed out one by one from the bottom of the stock unit 2 by the forward and backward movement of the delivery claw 3, and the cards S fed out from the stock unit 2 are once loaded into the reversing unit 4. After the reversing unit 4 is rotated 90 degrees from the horizontal state, when the card S is raised by the feed roller 6, the card S is fed into the magnetic reading / writing unit 7. The magnetic reading / writing unit 7 writes predetermined information in the magnetic stripe of the card S or reads predetermined information in the magnetic stripe.

  On the other hand, when the card S is lowered by the feed roller 6, the card S is fed into the non-contact IC reading / writing unit 8. Then, the non-contact IC reading / writing unit 8 writes predetermined information in the IC of the card S or reads predetermined information in the IC. After that, the card S sent out from the reversing unit 4 passes through the detachable cleaning roller 10, and then the card S is moved by the conveying roller 11 until just before image printing while being supported on both sides by the guide groove 12.

  In addition, when magnetic detection or non-contact IC detection is not necessary, the reversing unit 4 is maintained horizontally. The card S determined to be inappropriate by the magnetic reading / writing unit 7 or the non-contact IC reading / writing unit 8 is discharged into the eject box 9 by the feed roller 6 after the reversing unit 4 rotates.

  Next, in order to enable image transfer to the card S, the thermal transfer printing apparatus 1 includes a recording unit (primary transfer unit) A that thermally transfers an image to the film F, an image transferred to the film F, and the card S. And a re-transfer portion (secondary transfer portion) B that thermally transfers the image to the card S, and a warp correction portion C that corrects the warp of the card S after the image transfer.

  Further, the thermal transfer printing apparatus 1 includes a film cartridge 13 and a ribbon cartridge 14 that can be exchanged by inserting and removing. In the film cartridge 13, the film F is wound around a pair of upper and lower bobbins 15 and 16, and in the ribbon cartridge 14, the color ink ribbon R is wound around a pair of upper and lower bobbins 17 and 18. The color ink ribbon R in the ribbon cartridge 14 is periodically coated with ink of three colors (or four colors including black) of meltable or sublimable yellow, magenta, and cyan as one frame. ing.

  Here, in the recording unit A described above, the film F is wound around a substantially half circumference of the platen roller (commonly called “platen”) 20, and the color ink ribbon R is pressed against the film F on the platen roller 20 by the thermal head 21. . Then, the film F and the color ink ribbon R are sent downward while being synchronized, whereby the first color (yellow) of the color ink ribbon R is thermally transferred onto the film F by the heated thermal head 21.

  Next, the thermal head 21 is moved backward by the rack and pinion drive mechanism 22 so that the film F and the color ink ribbon R are separated from each other, while the platen roller 20 is reversed and the film F is raised to the original position. Return. Thereafter, while repeating the above-described transfer operation, colors are superimposed on the film F in the order of magenta, cyan, and black to create a desired color image on the film F.

  Thereafter, the recorded image on the film F is moved to the front of the heat roller 23 by the rotation of the bobbin 16 or the like. At this time, the leading edge of the card S is aligned with the leading edge of the recorded image on the film F, and the card S and the film F are sent to the retransfer section B in a state of being superimposed.

  In the re-transfer section B, the aligned card S and film F are sandwiched between the heat roller 23 and the pressure roller 24 in a superimposed state, and pressed with the heat roller 23 heated to 160 to 200 ° C. The recorded image on the film F is gradually transferred onto the surface of the card S while the card S and the film F are conveyed under pressure in cooperation with the roller 24. At this time, the film F is wound around the bobbin 16 while being peeled from the card S. Further, since the card S heated by the heat roller 23 is warped, the card S is sent to the warp correction unit C, subjected to pressure treatment, and then discharged out of the apparatus 1 in a straight state.

  Next, the heat roller 23 arranged in the apparatus 1 described above will be described in detail. FIG. 2 is a diagram illustrating a power circuit of the heat roller. As shown in the figure, a heating element 25 having a filament 26 is installed inside the heat roller 23. A power supply circuit 27 for energizing the heat generating element 25 is connected to both ends of the heat generating element 25. The power supply circuit 27 includes a fuse 29 for preventing an overcurrent in the power supply circuit 27, a temperature sensitive resistance element 30, a relay 31, a switching means 32, and a bypass circuit 33. In addition, an external power supply 28 is connected to a terminal of the power supply circuit 27 opposite to the heating element 25.

  The external power supply 28 is a commercial AC power supply for supplying power to the heat generating element 25 to generate heat, and there are various voltages, for example, 100V, 200V, 240V, 280V, etc. depending on the region of use.

  The heating element 25 is energized by being electrically connected to the external power source 28, and radiates heat from the inside of the heat roller 23 toward the surface by this energization. As such a heat generating element, a lamp element having a filament 26 is used, and a halogen lamp is preferable in terms of excellent response to supplied power. A halogen lamp is an incandescent lamp in which an inert gas such as nitrogen or argon and a trace amount of halide are enclosed in a glass container, and has a tungsten filament inside.

  The temperature sensitive resistance element 30 is an element connected in series between one terminal (one end) 34 of the heating element 25 and a terminal (connection terminal) 35 of the external power supply 28. The temperature-sensitive resistance element 30 has a characteristic that the electrical resistance decreases as the temperature rises due to self-energization. As such a temperature-sensitive resistance element 30, a thermistor made of a ceramic semiconductor obtained by sintering a metal oxide as a main raw material at a high temperature is preferably used because it has high sensitivity to temperature. Of these, a power thermistor is preferably used in that it can withstand the application of a high voltage.

  The relay 31 is a relay connected in series to one terminal 34 of the heating element 25 in the power supply circuit 27. The relay 31 receives an on / off control signal from a switching unit 32 described later, and is electrically opened and closed based on the on / off control signal. As an element used as the relay 31, it is preferable to use an SSR (Solid State Relay) which is a non-contact device by using a semiconductor element because of its high responsiveness to open / close control and low noise generation. .

  The switching means 32 is for controlling the relay 31 to alternately turn on and off the energization from the external power source 28 to the heating element 25. The switching means 32 is fixed in pressure contact with the surface of the heat roller 23, and includes a temperature measuring device 36 such as a thermistor for measuring the surface temperature of the heat roller 23, and measured surface temperature data of the heat roller 23. And a control unit 37 that controls opening and closing of the relay 31. Here, when the relay 31 is to be turned on, the control unit 37 transmits a DC voltage having a predetermined value to the relay 31 as an on / off control signal. When the relay 31 is to be turned off, the control unit 37 transmits a signal having a voltage value of 0 toward the relay 31 as an on / off control signal.

  In the above configuration, the control unit 37 controls the relay 31 as follows in order to keep the surface temperature of the heat roller 23 at about 200 ° C. or higher. First, after the main power supply of the intermediate transfer type thermal transfer printing apparatus 1 is turned on, the heating element 25 is energized to raise the surface temperature of the heat roller 23 to 200 ° C. After the surface temperature of the heat roller 23 reaches 200 ° C., the control unit 37 is used to maintain the relay 31 on for 6 seconds, and then the relay 31 is switched to the off state. Thereafter, the controller 37 is used to monitor the surface temperature of the heat roller 23, and when the temperature drops to 200 ° C., the relay 31 is turned on again. In this way, the relay 31 is repeatedly turned on and off for a predetermined time alternately and intermittently, whereby the energization of the heat generating element 25 is turned on / off in synchronism with the heat roller 23. The surface temperature is maintained at about 200 ° C.

  The bypass circuit 33 is connected in parallel to the temperature-sensitive resistance element 30, and includes a conductive portion 38 that bypasses the temperature-sensitive resistance element 30 and energizes the heating element 25, and a switch portion 39 that opens and closes the conductive portion 38. It consists of and. The conductive portion 38 may be formed of a conductive wire such as a lead wire, or may be formed of a metal pattern on the substrate. By such a detour circuit 33, both ends of the temperature-sensitive resistance element 30 are short-circuited as necessary.

  Then, the effect of the intermediate transfer type thermal transfer printing apparatus 1 concerning embodiment of this invention is demonstrated.

  In the intermediate transfer type thermal transfer printing apparatus 1, the heat roller 23 is heated to a certain range of temperature by controlling the energization of the heating element 25 from the external power supply 28, and the recorded image on the film F is transferred to the surface of the card S. Uneven transfer during printing is prevented. At this time, energization of the heat generating element 25 is alternately turned on / off in order to keep the heat roller 23 within a certain range of temperature. Immediately after the energization is turned on, since the filament 26 in the heating element 25 is in a low temperature state, the resistance value of the heating element 25 is relatively small. However, in this case, the temperature-sensitive resistance element 30 connected in series to the heating element 25 is also in a low temperature state, and the resistance value of the temperature-sensitive resistance element 30 is sufficiently large. As a result, the occurrence of an inrush current in the heating element 25 immediately after the energization is turned on is effectively prevented, and the occurrence of flicker is appropriately suppressed.

  Here, FIG. 3A shows a temporal state of the operating state of the relay 31 when a 100V external power supply 28, an AC 115V / 330W halogen lamp as the heating element 25, and a power thermistor as the temperature sensitive resistance element 30 are used. Showing change. As shown in FIG. 3A, the control of the switching means 32 causes the relay 31 to alternately repeat the on state for 6 seconds and the off state for about 40 seconds, so that the surface temperature of the heat roller 23 is in a substantially constant range. Maintained. FIG. 3B shows a temporal change in the surface temperature of the heat roller 23 based on on / off. Thus, by intermittent switching of the relay 31, the surface temperature of the heat roller 23 is maintained within a certain range near 200 ° C.

  When the power supply circuit 27 does not include the temperature sensitive resistance element 30, the current flowing through the heating element 25 in the steady state is approximately 2.9A in calculation, and the inrush current generated in the heating element 25 when the external power supply 28 is initially turned on. Reaches a maximum of about 50 A in actual measurement. On the other hand, since the temperature-sensitive resistance element 30 is provided in the power supply circuit 27, the temperature of the temperature-sensitive resistance element 30 is substantially equal to room temperature when the external power supply 28 is initially turned on. / 10.

  Thereafter, in the control as shown in FIG. 3A, the resistance value of the temperature-sensitive resistance element 30 has recovered to about 50% at room temperature when 40 seconds have elapsed since the relay 31 was switched off. . At this time, since the temperature of the filament 26 of the heat generating element 25 is also kept high compared to room temperature, the filament resistance is relatively large compared to when the power is initially turned on. Therefore, the resistance value of the entire circuit composed of the power supply circuit 27 and the heating element 25 is sufficiently secured, and the inrush current and flicker generated in the heating element 25 are surely generated when the relay 31 is switched to the ON state. To be suppressed. In particular, when the external power supply 28 is about 200V, large inrush current and flicker phenomenon are likely to occur. Therefore, the temperature-sensitive resistance element 30 is particularly useful when the external power supply 28 is 100V, not to mention when the external power supply 28 is 100V. In order to effectively suppress the occurrence of the inrush current in the heating element 25, it is preferable to control the relay 31 to be kept in the off state for 1 second or longer.

  Further, by providing the bypass circuit 33 connected in parallel to the temperature sensitive resistance element 30, when the voltage of the external power supply 28 to be used is relatively small such as 100V or less, the conductive portion 38 is closed by closing the switch portion 39. Thus, both ends of the temperature sensitive resistance element 30 can be electrically short-circuited. Thereby, the voltage applied to the heat generating element 25 is ensured, and insufficient heating of the heat roller 23 is avoided. Therefore, even if the voltage of the external power supply 28 to be used is not sufficient, the recorded image on the film F is uniformly and sufficiently thermally transferred to the surface of the card S in the intermediate transfer type thermal transfer printing apparatus 1.

  Note that the present invention is not limited to the above-described embodiments. For example, in the intermediate transfer thermal transfer printing apparatus 1 according to the present embodiment, a DC power supply may be used as the external power supply 28.

  Further, the switching means 32 has been operated so as to switch the relay 31 to the OFF state after maintaining the ON state for a certain period of time. However, the duration of the ON state may be variable, and the surface temperature of the heat roller may be changed. It may operate to switch to the off state accordingly.

1 is a front view showing an embodiment of an intermediate transfer type thermal transfer printing apparatus according to the present invention. It is a figure which shows schematically the power supply circuit of a heat roller. (A) is a figure which shows an example of the time change of the relay operation state in FIG. 2, (b) is a figure which shows an example of the time change of the heat roller surface temperature.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Intermediate transfer type thermal transfer printing apparatus, 23 ... Heat roller, 25 ... Heat generating element, 26 ... Filament, 27 ... Power supply circuit, 28 ... External power supply, 30 ... Temperature sensitive resistance element, 31 ... Relay, 32 ... Switching means, 34 ... terminal (one end), 35 ... terminal (connection terminal), 38 ... conductive part, 39 ... switch part, F ... film, S ... card (recording medium).

Claims (3)

In the intermediate transfer type thermal transfer printing apparatus that re-transfers the image on the film to the surface of the recording medium by pressing the film on which the image has been transferred to the recording medium while being heated by a heat roller.
A heating element having a filament installed in the heat roller and energized by being electrically connected to an external power source;
Switching means for alternately turning on and off energization from the external power source to the heating element;
A temperature-sensitive resistance element connected in series between one end of the heat generating element and the connection terminal of the external power source, and having a characteristic that electric resistance decreases with a temperature rise caused by self-energization,
An intermediate transfer type thermal transfer printing apparatus comprising: A conductive portion connected in parallel to the temperature-sensitive resistance element, for energizing the heating element by bypassing the temperature-sensitive resistance element;
A switch part for opening and closing the conductive part;
The intermediate transfer type thermal transfer printing apparatus according to claim 1, further comprising: The temperature sensitive resistance element is a power thermistor,
The heating element is a halogen lamp.
The intermediate transfer type thermal transfer printing apparatus according to claim 1 or 2.

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