JPH0664281A - Ultraviolet lamp cooling device of color thermal printer - Google Patents

Abstract

PURPOSE:To prevent the turning-over of the rear end part of a color thermal recording material due to the cooling air of an ultraviolet lamp. CONSTITUTION:A reflector 25 for yellow has the first bottom wall 26 positioned on the upstream side in the feed direction of a color thermal recording material provided to the bottom surface opposed to the color thermal recording material thereof and the second bottom wall 27 positioned on the downstream side in the feed direction of the color thermal recording material and allowed to approach the color thermal recording material as compared with the first bottom wall 26. The cooling air flowing in the reflector 25 from the side surface thereof is blown out toward the rear end of the color thermal recording material from the opening between the first and second bottom walls 26, 27. At the time of light fixation, ultraviolet rays pass through the opening to irradiate the color thermal recording material. A reflector 31 for magenta is constituted in the same way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet lamp cooling device for a color thermal printer, and more particularly to an ultraviolet lamp cooling device for preventing the trailing edge of a color thermal recording material from being curled up.

[0002]

2. Description of the Related Art Thermal printers include thermal printers and thermal transfer printers. Among them, thermal printers are widely used because they can directly thermally record an image on a thermal recording material. Recently, for example, as described in JP-A-61-213169,
A color thermosensitive recording material has been proposed in which a cyan thermosensitive coloring layer, a magenta thermosensitive coloring layer, and a yellow thermosensitive coloring layer are sequentially laminated on a support to enable direct thermal recording of a full-color image. This color thermosensitive recording material
Thermal recording is performed in order from the thermosensitive coloring layer on the surface, but when recording to the next thermosensitive coloring layer, in order to prevent the thermosensitive coloring layer that has already been recorded on it from being heat-recorded again, individual thermal recording is performed after the thermal recording. The thermosensitive coloring layer is irradiated with ultraviolet rays in a wavelength range peculiar to the thermosensitive coloring layer to lose its coloring ability.

[0003]

Since the ultraviolet lamp generates heat when emitting light, the temperature of the tube wall rises. As the tube wall temperature increases, the amount of light emission decreases. Therefore, it is necessary to cool the ultraviolet lamp in order to keep the amount of light emission constant. As a method of cooling the UV lamp, a ventilation hole is provided in the outer case of the printer and a natural air cooling type that cools the UV lamp by taking the outside air into the printer, and a fan is installed in the outer case of the printer to directly turn the outside air into the UV lamp. There is a forced air cooling type that applies and cools. conventionally,
Natural air cooling type was the mainstream, but recently, forced air cooling type is also increasing.

On the other hand, there is a thermal printer in which an ultraviolet lamp is housed in an elliptic cylindrical reflector having an opening on the bottom side facing the color thermosensitive recording material in order to increase the irradiation amount of ultraviolet rays. When forced air cooling is performed on this type of thermal printer, the cooling air that has entered through the opening on the side surface of the reflector is discharged downward through the opening on the bottom surface. This downward exhaust causes the rear end of the color thermosensitive recording material passing through the ultraviolet lamp to be flipped up, so that the ultraviolet rays cannot be uniformly irradiated and fixing unevenness may occur.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ultraviolet lamp cooling device which prevents curling of a color thermosensitive recording material.

[0006]

In order to achieve the above object, the present invention provides an ultraviolet lamp which is housed in a cylindrical reflector having a first side face closed, and which faces the color thermosensitive recording material. The bottom surface of the color thermosensitive recording material is provided with a first bottom wall located on the upstream side in the feeding direction and a second bottom wall located on the downstream side. The second bottom wall is brought closer to the color thermosensitive recording material. The cooling air that has entered the inside through the opened second side surface of the reflector is blown toward the rear end direction of the color thermosensitive recording material from the irradiation opening between the first bottom wall and the second bottom wall. Ultraviolet rays are applied to the color thermosensitive recording material through the irradiation opening.

Further, in the ultraviolet lamp cooling device according to the second aspect, a flexible skirt is attached to the second bottom wall so as to contact the color thermosensitive recording material.

Further, in the ultraviolet lamp cooling device according to the third aspect of the present invention, the first bottom wall extends into the ultraviolet irradiation area, an opening is formed in this extended portion, and a plate of an ultraviolet transmitting material is attached. is there.

[0009]

1 and 2, at least one portion of a sheet-shaped color thermosensitive recording material 10 is pressed and fixed to a platen drum 12 by a clamp member 11. During thermal recording and optical fixing, the platen drum 12
It is rotated at a constant speed by the pulse motor 13. A conveyance roller pair 15 is arranged in the paper feed / discharge path 14,
The color thermosensitive recording material 10 is conveyed through this space.
In this embodiment, one passage is used as both the paper feed passage and the paper discharge passage, but they may be provided separately.

A thermal head 16 is provided at the thermal recording position on the outer periphery of the platen drum 12, and ultraviolet lamps 17 and 18 for optical fixing are provided downstream of the thermal recording position. As is well known, the thermal head 16 has a large number of heating elements arranged in a line, and is heated to a temperature according to the color to be thermally recorded and its color density. The yellow ultraviolet lamp 17 emits an ultraviolet ray of about 420 nm, and the magenta ultraviolet lamp 18 emits an ultraviolet ray of about 365 nm.

A fan 21 is provided on the outer case 20 so as to be located on the side surface of the ultraviolet lamps 17 and 18, and is driven when the power of the color thermal printer is turned on. The fan 21 blows the outside air toward the ultraviolet lamps 17 and 18.

As shown in FIGS. 3 and 4, the yellow ultraviolet lamp 17 is housed in a cylindrical reflector 25 having a closed first side surface 25a which does not face the fan 21. Color thermosensitive recording material 1 of this reflector 25
On the bottom surface facing 0, a first bottom wall 26 located upstream of the color thermosensitive recording material 10 in the feeding direction and a second bottom wall 27 located downstream thereof are provided so that they are stepped. In addition, the second bottom wall 27 is closer to the color thermosensitive recording material 10 than the first bottom wall 26. Further, the inside of the reflector 25 is a reflecting surface so that the color thermosensitive recording material 10 can be efficiently irradiated with ultraviolet rays. In addition,
Reflector 3 for storing magenta UV lamp 18
Since 1 also has the same configuration, only reference numerals are given.

Next, the operation of this embodiment will be described. When the color thermal printer is turned on, the fan 21 starts driving. The cooling air that has flowed into the printer by the fan 21 is supplied to the second side surface 2 of the reflector 25.
Enter the inside of the reflector 25 from 5b. Since the first side surface 25a of the reflector 25 is closed, the cooling air travels along the inner wall of the reflector 25 toward the opening 28 formed in the bottom surface. However, the cooling air is blocked by the first bottom wall 26 and the second bottom wall 27, and the reflector 2
It is not discharged directly below 5. Further, the first bottom wall 26 and the second bottom wall 27 are stepped, and the opening 28 formed by these is formed in the color thermosensitive recording material 10.
Since it faces the upstream side of the feeding direction of,
The color thermosensitive recording material 10 is discharged toward the upstream side in the feeding direction. The cooling air that has flowed into the reflector 31 that houses the magenta ultraviolet lamp 18 is also discharged toward the upstream side in the feeding direction of the color thermosensitive recording material 10.

At the time of paper feeding, the pair of transport rollers 15 are used to feed the color thermosensitive recording material 10 supplied from a cassette (not shown).
Are conveyed toward the platen drum 12. When the color thermosensitive recording material 10 is set at the clamp position, the clamp member 11 presses and fixes the tip of the color thermosensitive recording material 10 against the platen drum 12. After that, the platen drum 12 and the conveying roller pair 15 rotate, and the color thermosensitive recording material 10 is wound around the platen drum 10. At the same time as the feeding of paper, the yellow ultraviolet lamp 17 also starts emitting light.

As the platen drum 12 rotates, the leading end of the recording area of the color thermosensitive recording material 10 reaches the thermal head 1.
When the number reaches 6, the yellow image is thermally recorded line by line by the thermal head 16. The portion on which the yellow image is thermally recorded reaches the yellow ultraviolet lamp 17 and is irradiated with the ultraviolet light passing through the opening 28 to be fixed. When the end of the color thermosensitive recording material 10 passes the yellow ultraviolet lamp 17, the yellow ultraviolet lamp 17
Stops emitting light. Since the cooling air discharged from the reflectors 25 and 31 faces the upstream side in the feeding direction of the color thermosensitive recording material 10, it should be blown from the rear end side to the color thermosensitive recording material 10 that has passed through the ultraviolet lamps 17 and 18. There is no. Particularly, when the rear end side of the color thermosensitive recording material 10 is being fixed by the ultraviolet lamp 17, the reflector 3
The rear end does not turn up due to the wind blown from 1.

When the platen drum 12 makes one rotation and the leading edge of the recording area of the color thermosensitive recording material 10 reaches the position of the thermal head 16 again, a magenta image is thermally recorded line by line. At the same time, the magenta UV lamp 18
Starts emitting light, and the color thermosensitive recording material 10 on which a magenta image is recorded is irradiated with ultraviolet rays to be fixed. When the end of the color thermosensitive recording material 10 passes the magenta ultraviolet lamp 18, the magenta ultraviolet lamp 18 stops emitting light. Further, the platen drum 12 is rotated so that the color thermosensitive recording material 10 faces the thermal head 16, and the thermal head 16 thermally records a cyan image line by line.

After the end of the thermal recording and the optical fixing, when the rear end of the color thermosensitive recording material 10 reaches the entrance of the paper feeding / discharging passage 14, the platen drum 12 is reversed and the color thermosensitive recording material 10 is supplied / discharging passage. You will be guided to 14. Then, when the color thermosensitive recording material 10 is nipped by the conveying roller pair 15, the platen drum 12 stops, and the color thermosensitive recording material 1
The fixing by the clamp member 11 of No. 0 is released, and the thermally recorded color thermosensitive recording material 10 is ejected to a discharge tray (not shown).
Is discharged to.

Next, another embodiment will be described with reference to FIG. In this embodiment, the second bottom wall 37 of the reflector 35 is used.
Further, a skirt 38 made of a flexible film is attached so as to come into contact with the color thermosensitive recording material. According to this embodiment, the opening 39 of the reflector 35 is blocked by the skirt 38 on the downstream side in the feeding direction of the color thermosensitive recording material 10. Therefore, in addition to the step between the first bottom wall 36 and the second bottom wall 37, The effect of discharging the cooling air to the rear end side of the color thermosensitive recording material 10 is enhanced. The skirt 38
Since any material may be used as long as it is flexible and has a density enough to block the cooling air, a soft brush may be used in addition to the above film.

Next, another embodiment will be described with reference to FIG. In this embodiment, the first bottom wall 42 of the reflector 41 is extended into the irradiation area of ultraviolet rays, and the opening 4 is formed in this extended portion.
2a is formed and the opening 42a is closed by a plate 44 made of an ultraviolet light transmitting material. According to this embodiment, the opening 42a can be formed large while preventing the cooling air from flowing out to the lower side of the reflector 41, so that a sufficient amount of ultraviolet rays applied to the color thermosensitive recording material 10 can be secured. be able to. Further, since the discharge angle of the cooling air is nearly horizontal to the color thermosensitive recording material 10, the effect of discharging the cooling air to the rear end side of the color thermosensitive recording material 10 is enhanced. The plate 44 may be made of a material that transmits ultraviolet rays, and thus transparent glass or a plastic material may be used, for example.

Further, in the above embodiment, the shape of the reflector is a rectangular tube, but the cross section may be parabolic in order to enhance the irradiation efficiency of ultraviolet rays.

[0021]

As described above, according to the present invention, it is possible to make a step difference by inserting an opening in the bottom surface of the reflector.
Two bottom walls are provided so that the cooling air is blown toward the rear end of the color thermosensitive recording material, so that the rear end of the color thermosensitive recording material can be prevented from being curled up and the ultraviolet rays can be uniformly irradiated. .

[Brief description of drawings]

FIG. 1 is a perspective view showing a color thermal printer including an ultraviolet lamp cooling device of the present invention.

FIG. 2 is a schematic view showing a color thermal printer.

FIG. 3 is a perspective view of an ultraviolet lamp cooling device of the present invention.

FIG. 4 is a cross-sectional view of the ultraviolet lamp cooling device shown in FIG.

FIG. 5 is a sectional view showing a second embodiment of the ultraviolet lamp cooling device.

FIG. 6 is a sectional view showing a third embodiment of the ultraviolet lamp cooling device.

[Explanation of symbols]

 10 Color Thermal Recording Material 16 Thermal Head 17 UV Lamp for Yellow 18 UV Lamp for Magenta 25, 31, 35, 41 Reflector 26, 36, 42 First Bottom Wall 27, 37, 43 Second Bottom Wall 38 Skirt 44 Plate

Claims (3)

[Claims] 1. A color thermosensitive recording material in which a plurality of thermosensitive coloring layers are layered on a support is used, and the color thermosensitive recording material and the thermal head are moved relative to each other while heat is applied to each thermosensitive coloring layer. In a color thermal printer for recording and performing optical fixing by irradiating the heat-recorded portion with ultraviolet rays from an ultraviolet lamp, the ultraviolet lamp is housed in a cylindrical reflector whose first side face is closed, and The bottom surface of the reflector facing the color thermosensitive recording material is provided with a first bottom wall located upstream of the color thermosensitive recording material in the feeding direction and a second bottom wall located downstream of the color thermosensitive recording material. like,
The second bottom wall is brought closer to the color thermosensitive recording material with respect to the first bottom wall, and the cooling air that has entered the inside through the second side surface where the reflector is opened is passed between the first bottom wall and the second bottom wall. The ultraviolet lamp cooling device is characterized in that it is blown out toward the rear end of the color thermosensitive recording material from the opening. 2. The ultraviolet lamp cooling device according to claim 1, wherein a flexible skirt is attached to the second bottom wall so as to contact the color thermosensitive recording material. 3. The first bottom wall extends into the ultraviolet ray irradiation area, an opening is formed in this extended portion, and a plate of an ultraviolet ray transmitting material is attached.
The described ultraviolet lamp cooling device.