JP2000185418A - Thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal printer which can speed up printing and reduce a margin. SOLUTION: A heating element array 6a for thermally recording to a color heat-sensitive recording paper 3, a surface light source 11 for yellow and a surface light source 12 for magenta for irradiating ultraviolet rays thereby fixing the color heat-sensitive recording paper 3 are incorporated in a thermal head 6. A spacer 17 formed of a low thermal conductivity material is inserted between a heat-radiating plate 14 as a base member of the thermal head 6 and, the yellow surface light source 11 and magenta surface light source 12 so as to prevent heat from adversely influencing the heating element array 6a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer, and more particularly, to a thermal head and a fixing device of a thermal printer.

[0002]

2. Description of the Related Art At least first to first different colors to be developed.
A third thermosensitive coloring layer is laminated, the lower thermosensitive coloring layer has lower thermal sensitivity, and the uppermost first thermosensitive coloring layer on the surface side and the second thermosensitive coloring layer thereunder are: There is a color thermal printer which uses a color thermal recording paper provided with a fixing property by ultraviolet light of a specific wavelength range so as to obtain a full color print. In this color thermal printer, while the color thermal recording paper is reciprocatingly conveyed, the thermal head is pressed to perform thermal recording on each thermal coloring layer, and after the thermal recording on each thermal coloring layer, a rod-shaped ultraviolet lamp is used as a light source. Ultraviolet rays are radiated using the used fixing device to fix the upper thermosensitive coloring layer so that the upper thermosensitive coloring layer does not develop color during thermal recording on the lower thermosensitive coloring layer.

[0003] A rod-shaped ultraviolet lamp used for a fixing device is generally circular in cross section, and ultraviolet rays are radiated with uniform intensity over the entire circumference. For this reason, a reflector having a high reflection ability is arranged near the ultraviolet lamp in order to reflect the unnecessarily radiated ultraviolet light toward the color thermosensitive recording paper.

[0004]

However, in the fixing device using the ultraviolet lamp and the reflector, the ultraviolet lamp and the reflector are used in order to effectively reflect the ultraviolet light reflected by the reflector toward the color thermosensitive recording paper. An appropriate gap is required between them. Therefore, the size of the fixing device itself has been increased, which has hindered downsizing of the color thermal printer. In addition, there are problems such as a decrease in printing speed due to an increase in the transport distance of the color thermal recording paper, an increase in margins, and insufficient fixing due to an increase in the distance between the fixing device and the color thermal recording paper.

An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide a thermal printer capable of increasing printing speed and reducing margins.

[0006]

In order to solve the above problems, a thermal printer according to the present invention uses a surface light source as a light source, and the surface light source is provided integrally with a thermal head. Further, a plurality of surface light sources are used and are arranged so as to sandwich the heating element array. Further, the surface light source
It is designed to be attached to a guide member that is attached to the thermal head and guides the thermal recording paper.

When the surface light source is mounted on the heat radiating plate of the thermal head via a low thermal conductivity material, the thermal head is arranged below the heat-sensitive recording paper transport path, and the heat radiating plate is brought into contact with the heat-sensitive recording paper. Thus, a spacer for forming a gap between the light source and the surface light source is integrally formed. Further, the heat radiating plate is formed in a shape along the conveyance path of the thermal recording paper.

In addition, wiring between the thermal head and a drive circuit for driving the thermal head is performed with a surface light source interposed therebetween, and wiring is performed on the light emitting surface of the surface light source. It is designed to be inclined with respect to the direction.

[0009]

FIG. 1 schematically shows a color thermal printer embodying the present invention. In this color thermosensitive printer, a color thermosensitive recording paper 3 is inserted from an insertion port 2 provided on the right side of the drawing with the recording surface provided with the thermosensitive coloring layer facing downward. The color thermosensitive recording paper 3 is subjected to thermal recording and fixing of a full-color image while being reciprocated in a forward direction which is an insertion direction and in a reverse direction thereof in a transport path from the insertion port 2 to the discharge port 4. . The color thermosensitive recording paper 3 on which the thermal recording has been completed is placed in an outlet 4 provided on the left side in the figure.
Is discharged from In order to reduce the size of the printer, the distance from the insertion port 2 to the discharge port 4 is smaller than the length of the color thermosensitive recording paper 3 in the insertion direction. Portions always protrude from the mouth 2 and the outlet 4.

[0010] A thermal head 6 is arranged at the back of the insertion port 2 below the conveyance path, and a platen roller 7 is arranged to face the thermal head. Further behind,
A reflective photosensor 8 for detecting the leading edge 3a of the color thermosensitive recording paper 3 and a pair of transport rollers 9 are arranged.
The platen roller 7 is freely movable between a recording position where the color thermosensitive recording paper 3 is sandwiched by being pressed against the thermal head 6 and a retreat position where a gap is formed apart from the thermal head 6.

As is well known, the color thermosensitive recording paper 3 is provided with a cyan thermosensitive coloring layer, a magenta thermosensitive coloring layer, and a yellow thermosensitive coloring layer in this order on a support. The yellow thermosensitive coloring layer serving as the uppermost first thermosensitive coloring layer has the highest thermal sensitivity, and develops yellow with small heat energy. The cyan thermosensitive coloring layer, which is the lowermost third thermosensitive coloring layer, has the lowest thermal sensitivity and develops cyan with a large thermal energy. The yellow thermosensitive coloring layer loses its coloring ability when irradiated with near-ultraviolet light of 420 nm. The magenta heat-sensitive coloring layer, which is the second heat-sensitive color-forming layer, develops magenta color with a thermal energy intermediate between the yellow heat-sensitive coloring layer and the cyan heat-sensitive coloring layer, and loses its coloring ability when irradiated with 365 nm ultraviolet rays. The color thermosensitive recording paper 3 may be provided with, for example, a black thermosensitive coloring layer to form a four-layer structure. Further, the positions of the thermosensitive coloring layers may be exchanged.

The thermal head 6 is a color thermal recording paper 3
A heating element array 6a in which a large number of heating elements are arranged in a line in a direction orthogonal to the transport direction of the sheet, a yellow surface light source 11 and a magenta surface light source 12 for fixing a yellow thermosensitive coloring layer and a magenta thermosensitive coloring layer. It has. The heating element array 6a is provided on a substrate 13 made of alumina, and the alumina substrate 13 is attached to a heat radiating plate 14 serving as a base member of the thermal head 6. The radiator plate 14 radiates heat generated by the heating element array,
It is formed of a metal having good thermal conductivity, for example, aluminum. A driver IC 15 for controlling the heating element array 6a is attached to the side surface of the heat radiating plate 14, and wiring is provided between the heating element array 6a and the driver IC 15.

The surface light source 11 for yellow and the surface light source 12 for magenta are incorporated in a concave portion 16 formed in the heat sink 14 via a spacer 17 formed of a low thermal conductivity material, for example, rubber. . In front of the light emitting surfaces of the yellow surface light source 11 and the magenta surface light source 12, filters are mounted to modulate the center wavelength of the emitted ultraviolet light to 420 nm and 365 nm, respectively. Instead of using a filter, a dedicated phosphor may be used for each of the surface light sources 11 and 12 to shift the center wavelength.

As the surface light source 11 for yellow and the surface light source 12 for magenta, a thin and space-saving panel light emitting display, for example, a plasma display panel is used. This plasma display panel is a He-X
A mixed gas such as e or He-Kr is sealed, and discharge light emission is performed. Also, the plasma display panel is
The luminous intensity is stable, and ultraviolet light having a constant luminous intensity can be irradiated over the entire region. However, when the surface of the color thermosensitive recording paper 3 is irradiated with ultraviolet rays by the surface light source having such light distribution characteristics, the illuminance on the color thermosensitive recording element 3 becomes almost 1 at both ends as shown by a two-dot chain line in FIG.
/ 2). This is because the light emitting areas of the surface light sources 11 and 12 facing both ends of the color thermosensitive recording paper 3 are halved with respect to the center. Such a decrease in illuminance at both ends causes uneven fixing and insufficient fixing in a color thermal printer.

In order to solve the above problem, the present invention provides:
As shown in FIG. 2A and FIG. 3 which is a view taken in the direction of arrow A in FIG. The width is increased in the transport direction. As a result, as shown by the solid line in FIG. 2B, the integrated illuminance of the ultraviolet light applied to both ends of the color thermosensitive recording paper 3 is improved, so that the same fixing performance as that at the center can be obtained.

Further, by incorporating the surface light source 11 for yellow and the surface light source 12 for magenta into the thermal head 6, the distance between the heating element array 6a and the surface light sources 11 and 12 is shortened. The path length can be shortened, the printing time can be shortened, and the margin of the color thermosensitive recording paper 3 can be reduced. Further, since the distance between the surface light source 11 for yellow and the surface light source 12 for magenta and the color thermosensitive recording paper 3 can be shortened, the illuminance of ultraviolet light is reduced, and the occurrence of fixing unevenness and fixing defects is reduced. Can be.

A guide ridge 19 projecting toward the conveying path of the color thermosensitive recording paper 3 is formed integrally with the edge of the heat radiating plate 14. The guide ridge 19 abuts against the color thermosensitive recording paper 3 to form a gap between the yellow surface light source 11 and the magenta surface light source 12 and the color thermosensitive recording paper 3. Prevents contact with 11 and 12.

The transport roller pair 9 includes a capstan roller 22 which is rotated in both directions by a motor, and a pinch roller 21 which is pressed against the capstan roller 22 and is rotatable. The transport roller pair 9 sandwiches the color thermosensitive recording paper 3 inserted from the insertion opening 2 and transports the recording paper 3 in the forward direction and the reverse direction.

Next, the operation of the above embodiment will be described. The color thermal printer shown in FIG. 1 is connected to, for example, a personal computer. If you have an image you want to print while using a personal computer,
A print start is instructed by operating a keyboard or the like of a personal computer. As a result, the print data is sent from the personal computer to the color thermal printer. The color thermal printer temporarily stores print data sent from a personal computer in a built-in memory.

After the print start operation, for example, a message that the print preparation is completed and a message that the color thermal recording paper 3 is to be inserted into the insertion slot 2 of the color thermal printer are displayed on the monitor of the personal computer, for example.

According to the message, the color thermosensitive recording paper 3
Into the insertion slot 2. When not in use, the platen roller 7 has been moved to a retreat position where the platen roller 7 is not pressed against the thermal head 6, so that the color thermosensitive recording paper 3 inserted from the insertion slot 2 passes between the thermal head 6 and the platen roller 7. Then, the leading end abuts on the conveying roller pair 9. On the way, the leading edge 3a of the color thermosensitive recording paper 3 is detected by the reflection type photo sensor 8.

When the reflection type photosensor 8 detects the leading edge 3a of the color thermosensitive recording paper 3, the motor for the conveying roller pair 9 starts to drive in response to the detection signal, and the capstan roller 22 is turned in the opposite direction in the figure. Rotate clockwise. Since the pinch roller 21 is urged downward by a spring (not shown) and pressed against the capstan roller 22, the pinch roller 21 is driven to rotate clockwise following the capstan roller 22, and the leading edge 3 a of the color thermosensitive recording paper 3 is rotated. Nip.

Color thermosensitive recording paper 3 by transport roller pair 9
Simultaneously with the nip, the platen roller 7 moves to the recording position and presses the color thermosensitive recording paper 3 to press the recording surface against the heating element array 6a.

The color thermosensitive recording paper 3 is transported in the forward direction by the forward rotation of the transport roller pair 9. Platen roller 7
Rotates counterclockwise following the transfer of the color thermosensitive recording paper 3. When the leading edge of the recording area reaches the heating element array 6a while the color thermosensitive recording paper 3 is being conveyed, each heating element generates heat energy corresponding to each pixel of the yellow image, and the yellow image is formed on the yellow thermosensitive coloring layer. Is thermally recorded line by line. The color thermosensitive recording paper 3 on which the yellow image has been thermally recorded has a leading end portion 3a protruding from the discharge port 4.

When the thermal recording on the yellow thermosensitive coloring layer of the color thermosensitive recording paper 3 is completed, the driving of the thermal head 6 is stopped, and the platen roller 7 moves to the retracted position. Immediately after this, the yellow surface light source 11 incorporated in the thermal head 6 is turned on, and the transport roller pair 9 starts to rotate in the reverse direction, and transports the color thermosensitive recording paper 3 from the rear edge toward the insertion slot 2. I do.

When the color thermosensitive recording paper 3 is transported in the reverse direction, ultraviolet light having a central wavelength of 420 nm is irradiated from the surface light source 11 for yellow toward the color thermosensitive recording paper 3. The yellow surface light source 11 fixes the yellow thermosensitive coloring layer so that yellow does not develop at the time of thermal recording on the next magenta thermosensitive coloring layer. The yellow surface light source 11
As shown in FIG. 3, since the width of the light emitting surface at both ends is wider than the central portion in the transport direction of the color thermosensitive recording paper 3 as shown in FIG. The integrated illuminance of the ultraviolet light applied to both ends of the heat-sensitive recording paper 3 is improved, and the same fixing performance as that at the center can be obtained.

Since the distance between the surface light source 11 for yellow and the heating element array 6a is short, the printing time is shortened.
The margin of the color thermosensitive recording paper 3 is reduced. Further, since the distance between the surface light source 11 for yellow and the color thermosensitive recording paper 3 is short, the illuminance of the ultraviolet light is less attenuated, and the fixing unevenness and the fixing failure do not occur.

When the leading edge of the recording area of the color thermosensitive recording paper 3 is transported again to the position of the heating element array 6a,
The transport roller pair 9 stops once, and the surface light source 1 for yellow
1 goes out. Then, the platen roller 7 returns to the recording position again, and the conveying roller pair 9 rotates forward to convey the color thermosensitive recording paper 3 in the forward direction. The thermal head 6 performs thermal recording by applying thermal energy according to the magenta image to the magenta thermosensitive coloring layer.

When the thermal recording of the magenta image is performed up to the rear end of the color thermal recording paper 3 in the forward direction, the platen roller 7 moves to the retreat position again to release the pressure on the thermal color recording paper 3 and the transport roller Pair 9 is stopped once. As in the case of yellow, immediately after this, the conveying roller pair 9 starts rotating in the reverse direction, and at the same time, the magenta surface light source 12 is turned on. The center wavelength 36 from the magenta surface light source 12
Ultraviolet light of 5 nm is applied to the color thermosensitive recording paper 3. The magenta light source 12 fixes the magenta thermosensitive coloring layer so that magenta does not develop color during the next thermal recording of the cyan thermosensitive coloring layer. Even when the magenta thermosensitive coloring layer is light-fixed, the integrated illuminance of ultraviolet light is constant in the width direction, so that the magenta thermosensitive coloring layer can be fixed without unevenness.

When the leading edge of the recording area of the color thermosensitive recording paper 3 is conveyed to the position of the heating element array 6a, the platen roller 7 returns to the thermal recording position as described above. At the same time, the transport roller pair 9 rotates forward to transport the color thermosensitive recording paper 3 in the forward direction. During this transport, the thermal head 6 thermally records a cyan image on the cyan thermosensitive coloring layer.

When the thermal recording on all the thermosensitive coloring layers is completed, the conveying roller pair 9 discharges the color thermosensitive recording paper 3 from the discharge port 4 as it is. The cyan thermosensitive coloring layer has no fixing property because the coloring heat energy has a value that does not cause coloring in a normal storage state.

As described above, the color thermal printer can be downsized by incorporating the surface light source for fixing into the thermal head. Further, since the distance between the heating element array and the surface light source is reduced, the margin of the color thermosensitive recording paper can be reduced, and the recording surface can be used effectively.
Further, the length of the color thermosensitive recording paper transport path is shortened, and the attenuation of ultraviolet rays is reduced, so that the printing time can be reduced. Further, since the integrated illuminance of the emitted ultraviolet light can be made uniform in the width direction of the color thermosensitive recording paper, a high-quality full-color print can be created without occurrence of fixing failure, fixing unevenness, and the like.

In the above embodiment, when the color thermosensitive recording paper is conveyed in the reverse direction, the surface light source is turned on to fix the thermosensitive coloring layer. However, the heating element array is also used as a light shielding plate. The fixing may be performed simultaneously with the thermal recording.
According to this, the printing speed can be further improved.

In the above-described embodiment, the thermal recording is performed by sandwiching the color thermosensitive recording paper between the small-diameter platen roller and the thermal head. However, as shown in FIG. The present invention is also applicable to a color thermal printer that performs thermal recording by winding the thermal recording paper 3. In this case, the heating element array 26
The heat radiating plate 30 of the thermal head 29 in which the surface light source 27 for yellow and the surface light source 28 for magenta are incorporated is bent into a shape along the outer periphery of the platen drum 25. Thereby, the color thermosensitive recording paper 3 and the yellow surface light source 27
In addition, the distance from the surface light source for magenta 28 can be reduced, and the same operation and effect as in the first embodiment can be obtained.

Further, as shown in FIG. 5, when a guide member 34 for guiding the color thermosensitive recording paper 3 is attached to the thermal head 35 while protecting a driver IC 33 for controlling the heating element array 32, Alternatively, a yellow surface light source 36 and a magenta surface light source 37 may be attached to the guide member 34. When the yellow surface light source 36 and the magenta surface light source 37 are attached to the guide member 34, an opening 34a for exposing the yellow surface light source 36 and the magenta surface light source 37 is formed in the guide member 34, 34 itself may be formed of a transparent acrylic plate or the like.

As shown in FIG. 6, a thermal head 43 may be constructed by disposing a yellow surface light source 40 and a magenta surface light source 41 on a heat sink 42 so as to sandwich the heating element array 39. Good. The yellow surface light source 41 and the magenta surface light source 4 sandwich the heating element array 39 therebetween.
2, the heating element array 39 and the driver IC
It becomes difficult to connect the wiring to the gate 44. Therefore, in this embodiment, the heating element array 39 and the driver IC are disposed between the heat sink 42 and one surface light source, for example, the yellow surface light source 40.
And a substrate 45 to which is attached.

As shown in FIG. 7, a substrate 50 on which a heating element array 49 is mounted is disposed between the yellow surface light source 47 and the magenta surface light source 48, and is disposed on the side of the yellow surface light source 47. The thermal head 53 may be configured by disposing a substrate 52 to which the driver IC 51 is attached. In the present embodiment, the wiring between the heating element array 49 and the driver IC 51 is performed on the light emitting surface of the yellow surface light source 47. Since the wiring between the heating element array 49 and the driver IC 51 is thin, fixing failure does not occur due to a decrease in the amount of ultraviolet light. FIG.
As shown in FIG. 8, which is a view from arrow B, the wiring on the yellow surface light source 47 is oblique to the transport direction of the color thermosensitive recording paper 3 to prevent the occurrence of fixing unevenness. can do.

As shown in FIG. 9, when the rotation of the platen roller 55 is not hindered, the heating element array 56
The thermal head 61 may be configured by mounting the driver IC 57 and the driver IC 57 on one substrate 58 and disposing the driver IC 57 between the yellow surface light source 59 and the magenta surface light source 60.

In each of the above embodiments, the illuminance of ultraviolet light on the color thermosensitive recording paper is made constant by changing the distribution of the light emitting area of the surface light source. The length of the recording paper may be made longer so that the portion where the light emission intensity decreases does not face the color thermosensitive recording paper. Further, the thickness of the phosphor layer inside the panel-shaped light emitting display used for the surface light source may be made thicker toward both ends. In a light emitting display, since the emission intensity is improved as the thickness of the phosphor layer is increased, the illuminance of the ultraviolet light applied to the color thermosensitive recording paper can be made constant.

Although the surface light source is composed of a single panel light emitting display, a plurality of surface light source elements composed of a small panel light emitting display are arranged to irradiate the entire area in the width direction of the color thermosensitive recording paper with ultraviolet rays. May be configured. Further, the illuminance distribution when the surface light source elements are used can be improved by controlling the light emission intensity of each surface light source element, switching between light emission and non-light emission of each surface light source element, and the like. In addition, a plasma display panel has been described as an example of a light emitting display used as a surface light source, but various panel-shaped light emitting displays such as a light emitting diode display, a field emission display, an inorganic electroluminescence display, and an organic electroluminescence display. Can be used. Further, a plurality of light emitting diodes may be arranged to form a surface light source.

Further, in the above embodiment, the low thermal conductivity material is used for the spacer, but the spacer may be formed of a material having a high reflectance and a low thermal conductivity. According to this, the spacer not only prevents the heat of the surface light source from being transmitted to the heating element array, but also functions as a reflector that reflects the ultraviolet light emitted from the surface light source toward the color thermosensitive recording paper. Can be.

In the above-described embodiment, a color thermal printer for performing thermal recording on a sheet of color thermal recording paper has been described as an example. Can also be applied. Furthermore, although a color thermal printer has been described as an example, the present invention can also be applied to a monochrome thermal printer.

[0043]

As described above, in the thermal printer of the present invention, since the surface light source and the thermal head are provided integrally, the thermal printer can be downsized. Further, since the distance between the heating element array and the surface light source is reduced, the margin of the thermosensitive recording paper can be reduced and the recording surface can be used effectively. Further, the length of the heat-sensitive recording paper transport path is reduced, and the attenuation of ultraviolet light is reduced, so that the printing time can be reduced. In addition, since the illuminance of the ultraviolet light can be easily made uniform in the width direction of the thermal recording paper, a high-quality full-color print can be created without occurrence of fixing failure, fixing unevenness, and the like.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a color thermal printer embodying the present invention.

FIG. 2 is a graph showing an illuminance distribution of a surface light source.

FIG. 3 is a view as viewed in the direction of arrow A in FIG. 1;

FIG. 4 is an explanatory diagram illustrating a thermal head according to a second embodiment.

FIG. 5 is an explanatory diagram illustrating a thermal head according to a third embodiment.

FIG. 6 is an explanatory diagram illustrating a thermal head according to a fourth embodiment.

FIG. 7 is an explanatory diagram illustrating a thermal head according to a fifth embodiment.

8 is a view as viewed in the direction of the arrow B in FIG. 7;

FIG. 9 is an explanatory diagram illustrating a thermal head according to a sixth embodiment.

[Explanation of symbols]

3 Color thermal recording paper 6, 29, 35, 43, 53, 61 Thermal head 6a, 26, 32, 39, 49, 56 Heating element array 11, 27, 36, 40, 47, 59 Yellow surface light source 12, 28 , 37, 41, 48, 60 Surface light source for magenta 14, 30, 42 Heat sink 17 Spacer

Continuation of the front page (72) Inventor Miyao Satoo 3-13-45 Izumi, Asaka-shi, Saitama Fuji Photo Film Co., Ltd. F-term (reference) 2C065 AA01 AB01 AC01 CJ02 CJ05

Claims (8)

[Claims] 1. A thermal head having a heating element array for performing thermal recording on a thermosensitive coloring layer by pressing against a thermosensitive recording paper, and a light source for fixing a recorded image by irradiating ultraviolet rays to the thermosensitive coloring layer. A thermal printer, wherein a surface light source is used as the light source, and the surface light source is provided integrally with a thermal head. 2. A thermal printer according to claim 1, wherein a plurality of said surface light sources are used and arranged so as to sandwich a heating element array. 3. The thermal printer according to claim 1, wherein the surface light source is attached to a guide member that is attached to a thermal head and guides the thermal recording paper. 4. The thermal printer according to claim 1, wherein the surface light source is attached to a heat radiating plate of a thermal head via a low thermal conductivity material. 5. The thermal head according to claim 1, wherein the thermal head is disposed below a heat-sensitive recording paper conveyance path, and a spacer that is in contact with the heat-sensitive recording paper and forms a gap between the thermal head and a surface light source is integrally formed. The thermal printer according to claim 4, wherein 6. The thermal printer according to claim 4, wherein the heat radiating plate is formed along a conveying path of the thermal recording paper. 7. The thermal printer according to claim 1, wherein wiring between the thermal head and a driving circuit for driving the thermal head is performed with a surface light source interposed therebetween. 8. The thermal printer according to claim 7, wherein the wiring is formed on the light emitting surface of the surface light source, and the wiring is inclined with respect to a conveying direction of the thermal recording paper.