JPH10264424A - Thermal coloring printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a luster property of a thermal recording paper and a density of an image by wiping dust such as a lubricant or the like from a recording surface. SOLUTION: A printed thermal recording piper 10 is passed between a cleaning roller 19 and a roller 20 to be discharged. A nonwoven fabric is attached to a circumference of the cleaning roller 19. When a protection layer 13 is pressed to be heated during the printing, a lubricant included therein comes out. Since the lubricant is stuck on the recording surface like a particle, a luster property and a density of the printed image are degraded. The lubricant stuck on the recording surface is wiped when passing through the cleaning roller 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive color printer, and more particularly to a heat-sensitive color printer for wiping a recording surface of a heat-sensitive recording paper and then discharging the paper.

[0002]

2. Description of the Related Art A thermosensitive color printer moves a thermosensitive recording paper relative to a thermal head and heats the thermosensitive recording paper with the thermal head during this movement to color-record an image. The thermal recording paper is classified into a monochrome type used for a facsimile and a monochrome thermal color printer, and a color type used for a color thermal color printer.

[0003] The monochrome thermosensitive recording paper has one type of thermosensitive coloring layer and at least one protective layer formed on a base. The thermal recording paper for color has at least three types of thermosensitive coloring layers of a cyan thermosensitive coloring layer, a magenta thermosensitive coloring layer, a yellow thermosensitive coloring layer, and at least one protective layer on a base. The yellow thermosensitive coloring layer on the front side has the highest thermal sensitivity and develops color with small heat energy. On the other hand, the cyan thermosensitive coloring layer, which is the lowermost layer,
Since it has the lowest thermal sensitivity, a large amount of heat energy is required for color development.

[0004] Each thermosensitive coloring layer is recorded sequentially from the uppermost layer. However, during recording of the magenta thermosensitive coloring layer, after the yellow image is printed, the uncolored components in the yellow thermosensitive coloring layer are not colored. Light is fixed by irradiating near ultraviolet rays of 420 nm. Similarly, after recording the magenta thermosensitive coloring layer,
The magenta thermosensitive coloring layer is light-fixed by irradiating 365 nm ultraviolet rays.

[0005]

At the time of printing, the thermal recording paper is heated by a thermal head to form a color on the thermal coloring layer. At this time, the lubricant contained in the protective layer is applied to the surface of the thermal recording paper. Emerges. Since this lubricant adheres to the recording surface like powder, the glossiness and the density are reduced, and the image quality is deteriorated. In addition, a large number of heating elements are arranged in a line on the thermal head, and each heating element generates heat in accordance with image data. Therefore, fine irregularities are formed on the protective layer. This unevenness also reduces the gloss and the density.

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermosensitive color printer capable of improving the image quality without reducing the gloss and the density.

[0007]

According to a first aspect of the present invention, there is provided a thermal color printer including a cleaning unit, which wipes a recording surface after recording an image, and wipes off dust such as a lubricant. It is something to do.

According to a second aspect of the present invention, in the thermal color printer, a rotatable cleaning roller having a nonwoven fabric attached to an outer periphery is used as the cleaning means.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG.
Is a thermosensitive coloring layer 1 that develops, for example, black on a support 11.
2, and a protective layer 13 are sequentially provided. This protective layer 1
Reference numeral 3 denotes a transparent resin layer, which prevents the heat-sensitive coloring layer from being damaged. This protective layer 13 may have a two-layer or three-layer configuration.

The thermal recording paper 10 is in the form of a sheet.
The sheet is nipped and transported by the transport roller pair 14. The upper side of the transport roller pair 14 is a capstan roller, and the lower side is a pinch roller. The capstan roller is rotated by a motor 15. The thermal recording paper 10 is fed one by one from a cassette (not shown). Note that a recording paper roll may be used, cut into sheets of a predetermined length after printing, and then discharged.

A platen roller 17 made of hard rubber is rotatably provided in front of the transport roller pair 14. A thermal head 18 is swingably provided to face the platen roller 17. This thermal head 18
The thermosensitive recording paper 10 on the platen roller 17 is pressed and heated so that the thermosensitive coloring layer 12 is colored. As is well known, on the lower surface of the thermal head 18, a heating element array 18a extending in the axial direction of the platen roller 17 is formed. The heating element array 18a includes a large number of heating elements arranged in a line.

A cleaning device is arranged downstream of the transport roller pair 14. The cleaning device includes a cleaning roller 19 and a freely rotating roller 20. The cleaning roller 19 has a nonwoven fabric attached to the outer periphery thereof, and wipes off dust such as a lubricant attached to the recording surface (the surface on the side of the thermosensitive coloring layer) of the printed thermosensitive recording paper 10. The nonwoven fabric is preferably replaceable.

Next, the operation of the above device will be described.
At the time of printing, the thermal recording paper 10 is sent out of the cassette and nipped by the transport roller pair 14. The thermal recording paper 10 is transported at a constant speed in the direction of the arrow by the transport roller pair 14. During this transport, the thermal head 18
Descends and presses the thermal recording paper 10. Each heating element of the thermal head 18 is energized according to image data. Each heating element heats the thermosensitive coloring layer 12 to develop a color.
An image is recorded on the thermal recording paper 10 line by line.

During printing, the protective layer 13 is heated by the thermal head 18, so that the lubricant contained in the protective layer 13 floats on the surface of the protective layer 13. With this lubricant, the glossiness and density of the image recorded on the thermal recording paper 10 are reduced. Further, fine irregularities are also formed on the protective layer 13.

During printing by the thermal head, the cleaning roller 19 is rotated by the motor 15 in the direction opposite to the direction in which the thermal recording paper 10 is conveyed. When the recorded thermosensitive recording paper 10 passes through the cleaning roller 19, the upper surface of the protective layer 13, that is, the recording surface is wiped.
As a result, dust such as lubricant attached to the recording surface is removed. In addition, when the pressure of the cleaning roller 19 is increased, the upper surface of the protective layer 13 is polished, so that irregularities formed during printing are removed. After this cleaning, the thermal recording paper 10 is discharged from the thermal printer.

When an experiment was conducted using a cleaning roller 19 in which Bencott (trade name, Asahi Kasei Kogyo Co., Ltd.) was attached to the outer periphery of a rubber roller, it was confirmed that the reflection density was improved by about 0.2.

In the cleaning device shown in FIG. 2, a fixedly disposed cleaning block 22 is used. The cleaning block 22 includes a block 23 having an arcuate lower surface, and a nonwoven fabric 24 attached to the lower surface of the block 23. During discharge, the roller 25 is driven by a motor, so that the thermal recording paper 10 passes between the cleaning block 22 and the roller 25. At this time, the recording surface is wiped by the cleaning block 22.

The present invention can also be applied to a color thermal printer that records a full-color image in three color planes sequentially using color thermal recording paper. When the color thermosensitive recording paper is discharged after recording the full-color image, dust adhered to the recording surface is wiped off by the cleaning device. Alternatively, immediately after recording of each color of yellow, magenta, and cyan,
The dust adhering to each of the cleaning devices may be wiped.

[0019]

According to the present invention having the above structure, the recording surface of the thermosensitive recording paper is wiped off after printing, so that dust such as a lubricant is removed, and the glossiness and density are increased. In addition, if the cleaning means is brought into strong contact with the recording surface to polish the recording surface, fine irregularities generated at the time of printing are scraped off, so that a decrease in glossiness due to the irregularities can be eliminated.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a thermal recording printer provided with a cleaning device.

FIG. 2 is a sectional view showing another example of the cleaning device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Thermal recording paper 18 Thermal head 19 Cleaning roller 20 Cleaning block

Claims (2)

[Claims] 1. A thermosensitive color printer which heats a thermosensitive recording paper with a thermal head to color-record an image on a recording surface, wherein a cleaning means for wiping the recording surface after recording the image is provided. Printer. 2. A thermosensitive color printer according to claim 1, wherein said cleaning means is a rotatable cleaning roller having a nonwoven fabric attached to an outer periphery thereof.