JP2005199611A - Thermal head and thermal printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To downsize a color thermal printer, reduce cost, lower power consumption and shorten a printing time. <P>SOLUTION: The thermal head 24 is formed by attaching a yellow print section 31, a magenta print section 32, and a cyan print section 33, and a yellow fixation section 34 and a magenta fixation section 35 to the underside of a board 30 formed of a high thermal conductivity material such as an aluminum and attaching a heat dissipation plate 36 to the top face of the board 30. The integration of the three print sections and two fixation sections allows the color thermal printer 2 to be reduced in size, and the reduction of the number of parts and assembly manpower makes cost reduction feasible. The heat of the yellow fixation section 34 and the magenta fixation section 35 is transmitted to the print sections 31 to 33 through the board 30 to use for printing, power consumption can be reduced and printing time can be shortened by shortening the time required for heating the heating element. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a thermal head and a thermal printer, and more particularly to a thermal head and a thermal printer used for printing on a thermal recording material having a plurality of thermal coloring layers that develop different colors.

  A color heat-sensitive recording paper in which a heat-sensitive color-developing layer that develops cyan, magenta, and yellow is formed on a support in this order is manufactured and sold by the present applicant. This color thermal recording paper is set so that the thermal sensitivity of the lowermost thermal coloring layer (cyan) is lower, and the uppermost (yellow) and intermediate (magenta) thermal coloring layers are fixed to ultraviolet rays. Sex has been granted. Therefore, by adjusting the thermal energy applied to the color thermal recording paper, and fixing the printed thermal coloring layer before printing on the next thermal coloring layer, each thermal coloring layer is formed in order from the upper layer. Can develop color. Further, a color thermal printer that can obtain a full color print using the color thermal recording paper is also manufactured and sold by the present applicant.

  The color thermal printer performs printing on a predetermined area of the color thermal recording paper by pressing the thermal head arranged along the main scanning direction while conveying the color thermal recording paper along the sub-scanning direction. The thermal head is provided with a plurality of heating elements corresponding to the respective pixels in the main scanning direction, and by generating heat in accordance with the image to be printed, these heat-sensitive coloring layers develop colors and prints. Done. After printing on the yellow thermosensitive coloring layer and after printing on the magenta thermosensitive coloring layer, the color thermosensitive recording paper is irradiated with ultraviolet rays using a fixing device so that no color develops during thermal recording on the next thermosensitive coloring layer. Has been established.

  In the fixing device, an ultraviolet lamp or LED is used as a light source (see, for example, Patent Documents 1 and 2). These ultraviolet lamps and LEDs generate a large amount of heat, and have a great influence on the environmental temperature in the housing of the color thermal printer. Therefore, a cooling mechanism such as a heat radiating fin or a heat radiating fan is required.

JP 2002-283653 A JP 2003-285456 A

  However, if the fixing device is provided with a cooling mechanism, the color thermal printer becomes larger and the cost increases. In addition, when a cooling fan or the like is used, the power consumption increases and the operation sound increases. Furthermore, from the viewpoint of energy saving, it has been considered whether the heat generated by the fixing device can be used for printing.

  SUMMARY OF THE INVENTION The present invention solves the above-described problems, and prevents an increase in size, cost, and power consumption of a color thermal printer by a fixing device cooling mechanism, and allows the heat generated by the fixing device to be used for printing. For the purpose.

  The thermal head of the present invention has a plurality of printing portions provided corresponding to a plurality of heat-sensitive color developing layers of a heat-sensitive recording material and a plurality of fixing portions that irradiate ultraviolet rays in a wavelength region corresponding to each heat-sensitive color developing layer. It is attached on the base plate.

  The base plate was made of aluminum. Further, an LED was used as a light source for the fixing unit. Further, a heat radiating plate for radiating heat from the printing unit and the fixing unit was attached to the base plate. Furthermore, the printing part was inclined and attached to the base plate.

  The thermal printer of the present invention comprises the above-described thermal head, a platen provided corresponding to each printing portion of the thermal head, and supporting the contact between each printing portion and the thermal recording material, and a thermal recording material. It comprised from the conveyance means to convey.

  In the thermal head and the thermal printer according to the present invention, since the printing unit and the fixing unit are mounted on a common base plate, for example, an aluminum base plate having high thermal conductivity, both can be cooled in common. Thus, space saving and cost reduction can be achieved. Further, the size can be reduced as compared with the case where the printing unit and the fixing unit are provided separately. Further, since heat generated from the fixing unit can be used for printing, power consumption can be reduced.

  In addition, since the printing portions are inclined and attached to the base plate, the thermal head can be further miniaturized by reducing the interval between the printing portions.

  FIG. 1 is a schematic diagram showing the configuration of a color thermal printer embodying the present invention. The color thermal printer 2 uses a long color thermal recording paper 3 as a recording material. The color thermal recording paper 3 is set in the color thermal printer 2 in the form of a recording paper roll 4 wound around the outer circumference of the core 4a.

  As shown in FIG. 2, the color thermosensitive recording paper 3 has a cyan thermosensitive coloring layer 7, a magenta thermosensitive coloring layer 8, a yellow thermosensitive coloring layer 9, and a protective layer 10 formed in this order on a support 6. The yellow thermosensitive coloring layer 9, which is the uppermost layer as the thermosensitive coloring layer, has the highest thermal sensitivity and develops yellow with a small amount of thermal energy. The cyan thermosensitive coloring layer 7 as the lowermost layer has the lowest thermal sensitivity and develops cyan with a large amount of heat energy. The yellow thermosensitive coloring layer 9 loses its coloring ability when irradiated with near ultraviolet rays of 420 nm. The magenta thermosensitive coloring layer 8 develops magenta with intermediate heat energy between the yellow thermosensitive coloring layer 9 and the cyan thermosensitive coloring layer 7, and loses the coloring ability when irradiated with 365 nm ultraviolet rays. For example, a color thermosensitive recording paper having a four-layer structure with a black thermosensitive coloring layer may be used.

  A paper feed roller 14 rotated by a transport motor 13 abuts on the outer peripheral surface of the recording paper roll 4 set in the color thermal printer 2. The carry motor 13 is a pulse motor and is driven by pulses input from the motor driver 15. When the paper feed roller 14 rotates counterclockwise in the figure, the recording paper roll 4 rotates clockwise in the figure, and the color thermal recording paper 3 is sent out from the recording paper roll 4. Conversely, when the paper feed roller 14 rotates clockwise in the figure, the recording paper roll 4 rotates counterclockwise in the figure to rewind the color thermal recording paper 3.

  The color thermal recording paper 3 sent out from the recording paper roll 4 is sent into a conveyance path arranged in the horizontal direction. In this conveyance path, a conveyance roller pair 18 is arranged to convey the color thermosensitive recording paper 3 in between. The conveyance roller pair 18 is composed of a capstan roller 18a rotated by the conveyance motor 13 and a pinch roller 18b in pressure contact with the capstan roller 18a. Reciprocating is carried in the A direction (paper feeding direction) and the B direction (rewinding direction) on the right side in the drawing. A discharge port 21 for discharging the printed color thermal recording paper 3 to the outside of the printer 2 is provided on the downstream side in the A direction of the pair of conveying rollers 18.

  Between the recording paper roll 4 and the transport roller pair 18, a thermal head 24 disposed above the transport path and platen rollers 25, 26 disposed below the transport path so as to face the thermal head 24. 27 are provided.

  The thermal head 24 includes, for example, a base plate 30 made of a metal having high thermal conductivity such as aluminum, and a yellow printing unit 31, a magenta printing unit 32, and a cyan printing unit 33 attached to the lower surface of the base plate 30. A yellow fixing unit 34 disposed between the yellow printing unit 31 and the magenta printing unit 32; a magenta fixing unit 35 disposed between the magenta printing unit 32 and the cyan printing unit 33; And a heat radiating plate 36 attached thereto. A temperature sensor 37 for measuring the temperature of the base plate 30 is incorporated in the base plate 30.

  As shown in FIG. 3, the yellow printing unit 31 includes a head substrate 31a formed of ceramic, alumina, alumina ceramic, or the like, a heating element array 31b provided on the lower surface of the head substrate 31a, and a heating element array 31b. It comprises a control IC 31c that individually controls a large number of heat generating elements. The heat generating element array 31b is formed by arranging a large number of heat generating elements in a line along the main scanning direction orthogonal to the conveyance direction of the color thermal recording paper 3. Since the magenta printing unit 32 and the cyan printing unit 33 have the same configuration as the yellow printing unit 31, detailed description thereof will be omitted.

  The yellow fixing unit 34 includes a large number of yellow light emitting diodes (Y-LEDs) 34a arranged in a plurality of rows along the main scanning direction on a substrate 34b. The yellow fixing unit 34 emits near-ultraviolet rays of 420 nm to generate a yellow thermosensitive coloring layer. Fixes so that no color develops even when 9 is heated. Further, in order to compensate for the shortage of light quantity between the Y-LEDs 34a in the sub-scanning direction, the columns in the main scanning direction are arranged by being shifted by a half pitch of the Y-LEDs 34a as shown in FIG. Are arranged in a zigzag pattern. The magenta fixing unit 35 has the same configuration as the yellow fixing unit 34 except that a magenta light emitting diode (M-LED) 35a that emits ultraviolet light of 365 nm is used as a light emitting diode. Description is omitted.

  The heat radiating plate 36 is made of a material having high thermal conductivity such as aluminum, and has a spread portion 36a attached to the upper surface of the base plate 30 and a number of fin portions erected vertically on the upper surface of the spread portion 36a. 36b. The heat radiating plate 36 radiates and cools the heat of the printing units 31 to 33 and the fixing units 34 and 35 transmitted to the base plate 30.

  The platen rollers 25 to 27 are rotatable. The platen rollers 25 to 27 are movable in the vertical direction, and are urged by a spring (not shown) in a direction in which they are pressed against the heating element arrays 31 b to 33 b of the printing units 31 to 33 of the thermal head 24. The platen rollers 25 to 27 are lowered by a shift mechanism including a cam and a solenoid during paper feeding and paper discharge, and form a gap with the thermal head 24.

  The color thermal recording paper 3 is sandwiched between the heating element arrays 31b to 33b and the platen rollers 25 to 27 when being transported in the A direction by the transport roller pair 18 during printing. Each heating element of each heating element array 31 b to 33 b generates heat based on the drive data input to the head driver 40, and causes each of the thermal coloring layers 7 to 9 of the color thermal recording paper 3 to color. The platen rollers 25 to 27 are driven to rotate in accordance with the conveyance of the color thermal recording paper 3 and stabilize the contact state between the color thermal recording paper 3 and the heating element arrays 31b to 33b. Further, the yellow fixing unit 34 and the magenta fixing unit 35 cause each LED to emit light by the LED driver 41 and fix each printed thermal coloring layer. The light emitted from the light emitting diode has high directivity and little divergence, so that the unrecorded thermosensitive coloring layer is not fixed.

  As described above, since the three print units 31 to 33 and the two fixing units 34 and 35 are attached to one base plate 30 and the thermal head 24 is integrated, the configuration of the color thermal printer 2 is simplified. be able to. In the conventional three-head type color thermal printer, it is necessary to alternately adjust the position of each thermal head and the platen roller and the position of each thermal head several times. In the head, since the position adjustment between the print sections can be performed when the thermal head 24 is assembled, it can be simplified. Furthermore, since the heat generated from the fixing units 34 and 35 is transmitted to the printing units 31 to 33 through the base plate 30, the heat of the fixing units 34 and 35 can be used for printing, thereby saving energy. be able to. Further, when a cooling fan or the like is installed in order to increase the cooling efficiency of the thermal head 34, the common heat radiating plate 36 may be cooled, so that the cooling can be efficiently performed with a small number of cooling fans.

  An optical sensor 44 that detects the leading edge of the color thermal recording paper 3 is incorporated on the downstream side of the conveying roller pair 18 in the A direction. A cutter 46 that cuts the color thermal recording paper 3 in the width direction is disposed downstream of the optical sensor 44 in the A direction. The cutter 46 includes a fixed blade 46a fixedly disposed below the conveyance path and a movable blade 46b disposed above the conveyance path and movable in the vertical direction by a cutter driving mechanism 47. The fixed blade 46a And the moving blade 46b, the color thermal recording paper 3 is sandwiched and cut.

  Each part of the color thermal printer 2 is controlled by the system controller 50. For example, the system controller 50 can perform various calculations based on a ROM in which a control program and control data are recorded, a RAM that is a work area in which the control program and control data read from the ROM are temporarily recorded, and a control program. It consists of CPU etc. which perform processing.

  Next, the operation of the above embodiment will be described. When the printing start operation is performed, the feeding roller 14 is rotated counterclockwise by the forward rotation of the conveyance motor 13, and the color thermal recording paper 3 is sent out from the recording paper roll 4 in the A direction. The leading end portion of the color thermal recording paper 3 moves in the conveyance path, is nipped by the conveyance roller pair 18, and is further conveyed downstream in the A direction. When the leading edge of the color thermal recording paper 3 is detected by the optical sensor 44, the rotation of the transport motor 13 is temporarily stopped. Thereafter, the pulses supplied to the transport motor 13 are counted, and the transport position of the color thermal recording paper 3 is specified by the system controller 50 based on the count value.

  The system controller 50 controls the shift mechanism to raise the platen rollers 25 to 27 and sandwich the color thermosensitive recording paper 3 between the heat generating element arrays 31 b to 33 b of the printing units 31 to 33. The yellow printing unit 31 of the thermal head 24 generates heat for each heating element based on the yellow image driving data input to the head driver 40, and one line of yellow image is formed on the yellow thermal coloring layer 9 of the color thermal recording paper 3. Make a print. Further, the conveyance motor 13 resumes normal rotation and conveys the color thermal recording paper 3 in the A direction by one line of the print. By repeating this, a yellow image is printed in the recording area for one screen of the color thermal recording paper 3.

  Simultaneously with the start of printing of the yellow image, the LED driver 41 causes the many Y-LEDs 34 a of the yellow fixing unit 34 to emit light, thereby fixing the yellow thermosensitive coloring layer 9. The light emitted from the light emitting diode has high directivity and little divergence, and therefore does not fix the unrecorded yellow thermosensitive coloring layer.

  When the leading end of the recording area of the color thermal recording paper reaches the magenta printing unit 32, the magenta printing unit 32 prints a magenta image by causing each heating element of the heating element array 32b to generate heat. At the same time, the M-LED 35a of the magenta fixing unit 35 is turned on, and the magenta thermosensitive coloring layer 8 is fixed.

  When the leading end of the recording area of the color thermal recording paper reaches the cyan printing section 33, the cyan printing section 33 generates heat by causing each heating element of the heating element array 33b to print a cyan image. The cyan thermosensitive coloring layer 7 is not provided with fixability because it is set to a thermal sensitivity that does not cause color development in the normal storage state because printing is performed last.

  Heat generated from the printing units 31 to 33 and the fixing units 34 and 35 of the thermal head 24 is transmitted to the aluminum base plate 30 and radiated from the heat radiating plate 36. Further, the system controller 50 measures the temperature of the base plate 30 to which the heat of each of the printing units 31 to 33 and the fixing units 34 and 35 has been transmitted by the temperature sensor 37, and based on this temperature, the printing units 31 to 31 are measured. The drive data for driving the 33 heating elements is corrected. For example, when the temperature of the base plate 30 is high, correction is made so as to reduce the energy of bias heating that raises the temperature of each heating element to the temperature for gradation recording that actually colors each thermosensitive coloring layer. As a result, the heat of the fixing unit, which has conventionally only been radiated, can be used for printing, which can contribute to power saving of the color thermal printer 2. In addition, since the time required for bias heating is shortened, it is possible to contribute to shortening the printing time.

  On the leading edge side of the top recording area of the color thermosensitive recording paper 3, there is a blank portion to be sandwiched and conveyed by the conveying roller pair 18. This blank portion is cut by the cutter 46 and discharged from the discharge port 21. Discharged from the printer. In addition, the trailing edge of the recording area is also cut by the cutter 46, configured as a single sheet-like color print, and discharged from the discharge port 21.

  In the above embodiment, the head substrates 31a to 33a of the printing units 31 to 33 are horizontally attached to the lower surface of the base plate 30, but the thickness of the base plate 56 of the thermal head 55 is increased as shown in FIG. In addition, the head substrates 57a, 58a, 59a of the yellow printing unit 57, the magenta printing unit 58, and the cyan printing unit 59 may be inclined thereto, and the yellow fixing unit 60 and the magenta fixing unit 61 may be attached therebetween. According to this, since the pitch between the printing units 57 to 59 can be narrowed, the printer can be downsized and the printing time can be shortened.

  In the above embodiment, the fixing unit using LEDs has been described as an example. However, a fixing unit using an ultraviolet lamp or a strobe lamp may be incorporated in the thermal head. Furthermore, although aluminum is used as the material of the base plate, the base plate may be formed of other materials having high thermal conductivity.

1 is a schematic diagram illustrating a configuration of a color thermal printer embodying the present invention. It is principal part sectional drawing which shows the layer structure of a color thermal recording paper. FIG. 2 is a schematic diagram illustrating a configuration of a yellow printing portion and a yellow fixing portion of a thermal head. It is explanatory drawing which shows the arrangement state of Y-LED of a yellow fixing part. It is the schematic which shows the structure of the thermal head of another embodiment of this invention.

Explanation of symbols

2 Color thermal printer 3 Color thermal recording paper 24,55 Thermal head 25-27 Platen roller 30 Base plate 31,57 Yellow printing part 32,58 Magenta printing part 33,59 Cyan printing part 34,60 Yellow fixing part 35,61 Magenta Fixing part 36 Heat sink 37 Temperature sensor

Claims (6)

  The thermal coloring layer that is colored by heating and fixed by ultraviolet rays in a specific wavelength range is a thermal head that prints on a thermal recording material formed corresponding to a plurality of different colors. A thermal head comprising: a plurality of printing sections that generate heat and print correspondingly; and a plurality of fixing sections that irradiate ultraviolet rays in a wavelength region corresponding to each thermal coloring layer on a common base plate.   The thermal head according to claim 1, wherein the base plate is made of aluminum.   The thermal head according to claim 1, wherein an LED is used as a light source of the fixing unit.   4. The thermal head according to claim 1, wherein a heat radiating plate for radiating heat from the printing unit and the fixing unit is attached to the base plate.   The thermal head according to claim 1, wherein the printing portion is inclined and attached to a base plate.   A thermal head according to any one of claims 1 to 5, a plurality of platens provided corresponding to each printing portion of the thermal head and receiving contact with the thermal recording material by each printing portion, and conveying the thermal recording material A thermal printer characterized by comprising a conveying means.

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