JP2766579B2 - Thermal printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer for optically fixing a thermally recorded heat-sensitive recording material.

[0002]

2. Description of the Related Art In a thermal printer, a heat-sensitive recording material having a heat-sensitive coloring layer provided on a support is used, and a thermal head is pressed against the heat-sensitive coloring layer and heated to develop color. Portions that are not heated by the thermal head have color-forming ability, so if heat is applied during storage, they will develop color. Therefore, after the thermal recording of the thermosensitive recording material, by irradiating electromagnetic rays such as ultraviolet rays with an optical fixing device,
The coloring ability is lost.

In addition, a yellow thermosensitive coloring layer, a magenta thermosensitive coloring layer, and a cyan thermosensitive coloring layer are sequentially provided on a support, and
A color thermosensitive recording material which records a color image by multiple thermal recordings is also known (for example, JP-A-61-213169).
issue). In this color thermosensitive recording material, the second magenta thermosensitive coloring layer is thermally recorded after the first thermosensitive coloring layer provided on the surface side, for example, the yellow thermosensitive coloring layer. During the thermal recording of the magenta thermosensitive coloring layer, the yellow thermosensitive coloring layer is also heated, so that the unrecorded portion develops color. Thus, the yellow thermosensitive coloring layer contains a diazonium salt compound that decomposes with near-ultraviolet light of about 420 nm, and the magenta thermosensitive coloring layer contains a diazonium salt compound that decomposes with ultraviolet light of about 365 nm.

The ultraviolet lamp used in the above-mentioned optical fixing device is mounted at a position where the distance from the heat-sensitive recording material is made as small as possible in order to increase the effective amount of light applied to the heat-sensitive recording material and improve the fixing efficiency. For example, the distance from the heat-sensitive recording material wound around the platen drum is set to about 5 mm.

[0005]

However, since the heat-sensitive recording material has a front end fixed by a clamp member but a rear end free, the rear end is separated from the surface of the platen drum and the surface of the ultraviolet lamp is separated. May come into contact with. When the heat-sensitive recording material comes into contact with the ultraviolet lamp, there is a problem that a layer that has not been thermally recorded is recorded by the heat of the ultraviolet lamp. Further, it is necessary for the heat-sensitive recording material to be bleached by irradiating ultraviolet rays to a portion other than the recording surface on which an image is recorded, for example, an edge portion, etc., and this bleaching is performed at the time of feeding, discharging, or fixing. In this case, there is a problem that a portion that is not bleached by the paper guides provided in these transport paths occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to prevent a heat-sensitive recording material from being thermally recorded by contacting a lamp, and to prevent a portion which is not bleached by a paper guide. It is an object to provide a thermal printer as described above.

[0007]

SUMMARY OF THE INVENTION A thermal printer according to the present invention performs thermal recording on a thermosensitive coloring layer of a thermosensitive recording material, and
A thermal pre that fixes by irradiating ultraviolet rays from the wearing light source
Between the fixing light source and the heat-sensitive recording material.
In addition, the heat-sensitive recording material floats while collecting the ultraviolet light.
When this is done, the thermal recording material and the fixing light source
Is provided with a lens member for preventing contact with the lens. Ma
The paper is guided by a paper guide
After thermal recording on the thermal coloring layer of the thermal recording material sent,
A thermal pump that fixes by irradiating ultraviolet rays from a fixing light source
In the linter, at least one of the paper guides
A paper guide provided near the fixing light source,
It is made of a material that transmits ultraviolet light, and
In order to prevent the thermal recording material from contacting the fixing light source,
Guide both edges of the recording material away from the fixing light source
Is what you do. In addition, the paper guide provided in the conveyance path
Thermosensitive coloring layer of thermosensitive recording material guided and transported by guide
Heat recording, and then irradiate with ultraviolet rays from the fixing light source.
In a thermal printer for fixing, the paper guide
At least in the vicinity of the fixing light source.
The paper guide is provided between the fixing light source and the heat-sensitive recording material.
A flat plate made of a material that transmits ultraviolet light
The member has a plurality of holes .

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG.
A pulse motor (not shown) is connected to the rotation shaft 11, and rotates in the direction of the arrow with the color thermosensitive recording material 13, the tip of which is fixed by a clamp member 12, wound therearound. At the print position, a thermal head 15 and a light fixing device 16 for yellow and a light fixing device 17 for magenta are arranged below the platen drum 10 downstream thereof. As is well known, the thermal head 15 has a large number of heating elements arranged in a line in the main scanning direction, and each heating element generates heat energy according to the density of a pixel. The light fixing device 16 for yellow includes a rod-shaped ultraviolet lamp 18 having a light emission peak of approximately 420 nm and a reflector 19, and the light fixing device 17 for magenta includes an ultraviolet lamp 20 having a light emission peak of approximately 365 nm and a reflector 21.

Between the outer peripheral surface of the platen drum 10 and the optical fixing device 16 for yellow and the optical fixing device 17 for magenta,
For example, each lens as a lens
A varnish lens type contact prevention member 32 , 33 is provided. The contact preventing members 32 and 33 are made of a UV-permeable material, for example, a thermosetting resin RAV7 (trade name, manufactured by Mitsui Petrochemical) in the form of a meniscus lens, and are emitted from the UV lamps 18 and 20. Collected ultraviolet light
And irradiate the color thermosensitive recording material 13 with light without waste.
When the color thermosensitive recording material 13 is loosely wound around the outer peripheral surface of the platen drum 10, the color thermosensitive recording material 13
Are the optical fixing unit 16 for yellow and the optical fixing unit 17 for magenta.
Avoid contact with

The contact preventing members 32 and 33 are provided with ultraviolet rays.
UV rays emitted from the pumps 18 and 20 are collected and
Since the color thermosensitive recording material 13 is irradiated,
It can contribute to shortening. Also, the diffusion of UV light is prevented.
As a result, the surrounding members will not be exposed to strong ultraviolet rays,
It is not necessary to consider light resistance. In addition, purple
There is also an advantage that outside line leakage is prevented. In addition,
The touch prevention members 32 and 33 are not limited to the meniscus lens type,
For example, a Fresnel lens type or the like may be used.

As shown in FIG. 2, a color thermosensitive recording material 1
In 3, a cyan thermosensitive coloring layer 26, a magenta thermosensitive coloring layer 27, and a yellow thermosensitive coloring layer 28 are sequentially provided on a support 25. These thermosensitive coloring layers 26 to 28 are arranged from the surface in the order of thermal recording. For example, in the case of thermal recording in the order of magenta, yellow, and cyan, the magenta thermosensitive coloring layer 27 and the yellow thermosensitive coloring are used. Layer 28
And the positions are swapped.

As the support 25, an opaque coated paper or a plastic film is used. When an OHP sheet is formed, a transparent plastic film is used. The cyan thermosensitive coloring layer 26 contains an electron-donating dye precursor and an electron-accepting compound as main components, and develops cyan when heated. Magenta thermosensitive coloring layer 2
No. 7 contains a diazonium salt compound having a maximum absorption wavelength of about 365 nm and a coupler which reacts with the diazonium salt compound and develops magenta. When the magenta thermosensitive coloring layer 27 is irradiated with ultraviolet light near 365 nm after thermal recording, the diazonium salt compound is photolyzed and loses its coloring ability. The yellow thermosensitive coloring layer 28 has a maximum absorption wavelength of about 42
It contains a diazonium salt compound having a thickness of 0 nm and a coupler which reacts with the diazonium salt compound to develop a yellow color. When the yellow thermosensitive coloring layer 28 is irradiated with near ultraviolet light (blue violet light) of about 420 nm, the yellow thermosensitive coloring layer 28 is light-fixed and loses its coloring ability.

FIG. 3 shows the coloring characteristics of each of the thermosensitive coloring layers 26 to 28. The thermal energy on the horizontal axis represents the thermal energy generated by the heating element. The thermal energy of the yellow thermosensitive coloring layer 28 is the lowest, and the thermal energy of the cyan thermosensitive coloring layer 26 is the highest. The main cause of this difference in thermal energy is that the cyan thermosensitive coloring layer 26 must be heated via the yellow thermosensitive coloring layer 28 and the magenta thermosensitive coloring layer 27.

Next, the operation of the above embodiment will be described. When the platen drum 10 is rotated in the direction of the arrow and the leading end of the recording area of the color thermosensitive recording material 13 reaches the thermal head 15, thermal recording of a yellow image is started.
The thermal head 15 generates thermal energy within a range of, for example, 20 to 35 mJ / mm ² according to the recording density of the pixel, and thermally records a yellow image line by line on the yellow thermosensitive coloring layer 28. Thermal recording by the thermal head 15 is performed while the platen drum 10 makes one rotation.

As the rotation of the platen drum 10 advances, the ultraviolet lamp 18 is turned on immediately before the clamp member 12 reaches the position of the yellow light fixing device 16. As a result, approximately 420 nm emitted from the ultraviolet lamp 18 is emitted.
Near-ultraviolet light is collected by the contact prevention member 32 and is wasted.
The recording is performed by the thermal head 15, and the yellow thermosensitive coloring layer 28 is optically fixed. At this time, the vicinity of the tip fixed by the clamp member 12 is near the ultraviolet lamp 1.
8 is stable, but as the rotation of the platen drum 10 advances, the end 13a of the color thermosensitive recording material 13
Hangs down from the outer peripheral surface of the platen drum 10 and approaches the ultraviolet lamp 18. However, the contact prevention member
By 32 , the color thermosensitive recording material 13 is received. Therefore, the color thermosensitive recording material 13 does not approach the ultraviolet lamp 18 too much, and the recording of the next magenta thermosensitive coloring layer 27 by the heat of the ultraviolet lamp 18 is avoided.

When the platen drum 10 enters the second rotation,
The thermal head 15 thermally records a magenta image line by line on the magenta thermosensitive coloring layer 27. During recording of this magenta image, the yellow thermosensitive coloring layer 28 is also heated,
Since the coloring ability has already been lost, the yellow thermosensitive coloring layer 28 does not develop color. As the rotation of the platen drum 10 proceeds, the clamp member 12
Immediately before reaching the position 6, the ultraviolet lamp 18 is turned off, and the ultraviolet lamp 20 of the magenta light fixing device 17 is turned on instead. As a result, approximately 365 nm is applied to the color thermosensitive recording material 13 via the contact prevention member 33.
Of ultraviolet rays is condensed and irradiated, and the magenta thermosensitive coloring layer 27
Light fixing is performed. At this time, the color thermosensitive recording material 13 does not come too close to the ultraviolet lamp 20 by the contact preventing member 33 , and the recording of the next cyan thermosensitive coloring layer 26 by the heat of the ultraviolet lamp 20 is prevented.

When the platen drum 10 further rotates and reaches the third rotation, the thermal head 15 thermally records the cyan image on the cyan thermosensitive coloring layer 26 line by line. Immediately before the rotation of the platen drum 10 and the clamp member 12 reaches the position of the magenta optical fixing device 17, the ultraviolet lamp 20
Is turned off. Then, just before the platen drum 10 enters the fourth rotation, the thermal recording of the cyan image is completed. In addition,
The cyan thermosensitive coloring layer 26 has a considerably high thermal energy required for thermosensitive coloring and does not develop a color in a normal storage state. Therefore, light fixing to the cyan thermosensitive coloring layer 26 is omitted.

In each of the embodiments described above, a thermal printer using a platen drum is used . However, as shown in FIG. 4 , in the present invention, the color thermosensitive recording material 13 is horizontally moved by a pair of conveying rollers 51 and 52. The invention can also be applied to a reciprocating type thermal printer. A platen drum 53 is provided between the pair of transport rollers 51 and 52, and a thermal head 54 is provided below the platen drum 53. On the right side of the platen drum 53, there is a light fixing device 56 for yellow.
A magenta optical fixing device 57 is disposed on the left side, and paper guides 58 and 59 are provided below each. The paper guide 58 and 59, for example, FIG.
As shown in FIG. 5 (A), the groove type guides both edges of the color thermosensitive recording material 13 and is formed of a material that transmits ultraviolet light.

In the thermal printer constructed as described above, first, in a state where the magenta optical fixing device 57 is turned off,
The color thermosensitive recording material 13 is guided by a paper guide 58 and is conveyed toward a recording position. When the leading end of the recording area of the color thermosensitive recording material 13 reaches the recording position, thermal recording of a yellow image is started by the thermal head 54 and the yellow optical fixing device 56 is turned on.
Color thermal recording material 13 that has entered paper guide 59
Is approximately 4 including the edge covered with the paper guide 59.
Irradiation with ultraviolet rays of 20 nm is performed, and the yellow thermosensitive coloring layer is optically fixed .

The thermal recording and light fixing of the yellow image are completed.
Then, the platen drum 53 is reversed and color thermal recording
The material 13 starts to be conveyed to the left in the drawing. This is a
Is turned off erotic over a fixer 56, a magenta instead
The optical fixing device 57 is turned on. Covered with paper guide 58
UV light is also applied to the edge of the recording material, and the color thermosensitive recording material 1
The magenta thermosensitive coloring layer No. 3 is light-fixed. After this, again
The platen drum 53 is rotated, and the color thermosensitive recording material 1
3 is paper guide while thermal recording of cyan image is performed
The paper is discharged through 59. At the time of this paper ejection, the light for yellow
Lights both the fixing unit 56 and the magenta optical fixing unit 57
And the edges covered with paper guides 58 and 59
The entire surface of the thermal recording material 13 may be further bleached.

[0021] Incidentally, paper guide shape, in addition to the groove type, for example, as shown in FIG. (B), holes of several 63
It may be to open to increased the amount of transmission of ultraviolet paper guide 62a, 62 b. Further, the ultraviolet-transparent material may be used only for the paper guide on the optical fixing device side.

Although the above embodiment is directed to a line printer for recording by moving a thermal head or recording paper relatively in the sub-scanning direction, the present invention is also applicable to a serial printer for recording by moving relative to two dimensions. be able to. In this serial printer, heating elements are arranged in the main scanning direction,
A thermal head that moves in the sub-scanning direction during thermal recording is used, and the recording paper moves in the main scanning direction.

[0023]

As described above in detail, according to the thermal printer of the present invention, the ultraviolet ray is focused between the fixing light source and the thermal recording material, and the thermal recording material floats.
When this occurs, the thermal recording material and the fixing light source
Is provided with the lens member to prevent contact, it is possible to prevent the heat-sensitive recording material can be prevented from heat-sensitive recording material even if floating contacts the fixing light source, the heat-sensitive recording material is excessively fixing, fixing The ultraviolet light emitted from the light source
Prevents the loss and unevenness of ultraviolet rays by shining ,
High efficiency and uniform light fixing can be performed , and the fixing time is short.
Can contribute to shrinkage. In addition, the paper guide provided in the conveyance path
Of the guide at least in the vicinity of the fixing light source.
The paper guide is formed from an ultraviolet-transparent material, and heat-sensitive recording
Guided both edges of the material away from the fixing light source
Since, Rutotomoni can be kept substantially constant distance between the heat-sensitive recording material and the fixing light source was covered with paper guide
Ultraviolet rays can be applied to the edges, and uniform light fixing can be performed. Also, a flat plate made of UV-permeable material
A paper guide with multiple holes in the member is used as a fixing light source.
The distance between the heat-sensitive recording material and the fixing light source is almost constant, for example , even in a thermal printer in which the heat-sensitive recording material is reciprocated in the horizontal direction because it is provided between the heat-sensitive recording material.
And increase the amount of UV radiation
And can contribute to shortening of the fixing time.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing a thermal printer.

FIG. 2 is an explanatory diagram showing a layer structure of a color thermosensitive recording material.

FIG. 3 is a graph showing the color development characteristics of a color thermosensitive recording material.

FIG. 4 is a schematic view showing a horizontal reciprocating thermal printer.
FIG.

FIG. 5 is an explanatory view showing various shapes of a paper guide.
You.

[Explanation of symbols]

1 0 platen drum 13 color thermosensitive recording material 15,54 thermal head 16, 5 6 yellow fixer 17, 5 7 magenta fixer 18, 20 ultraviolet lamp 3 2,3 3 contact prevention members 58 and 59, 6 2 Paper Guide

Claims (3)

(57) [Claims] 1. A thermal printer for performing thermal recording on a heat-sensitive coloring layer of a heat-sensitive recording material and then irradiating ultraviolet light from a fixing light source to fix the heat-sensitive recording material, wherein the ultraviolet light is interposed between the fixing light source and the heat-sensitive recording material. To
When the heat-sensitive recording material floats while receiving light,
To prevent contact between the thermal recording material and the fixing light source
A thermal printer comprising a lens member . 2. A paper guide provided in a conveying path.
Thermal recording on the thermosensitive coloring layer of the thermosensitive recording material transported inside
And then irradiate with ultraviolet light from the fixing light source to fix
In the thermal printer, at least the fixing light source of the paper guide is used.
The paper guide provided in the vicinity is made of UV-permeable material
And the heat-sensitive recording material is fixed.
So that it does not come into contact with the light source for
The feature is that it is guided at a position away from the fixing light source.
Thermal printer to be. 3. A paper guide provided in a conveying path.
Thermal recording on the thermosensitive coloring layer of the thermosensitive recording material transported inside
And then irradiate with ultraviolet light from the fixing light source to fix
In the thermal printer, at least the fixing light source of the paper guide is used.
The paper guide provided in the vicinity is the same as the fixing light source.
Provided between the thermosensitive recording material and the
The formed flat member is provided with a plurality of holes.
And a thermal printer.