JP2934147B2 - Paper cassette and 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 paper feed cassette for storing thermal recording paper and a thermal printer using the same.

[0002]

2. Description of the Related Art A thermosensitive thermal printer uses a thermosensitive recording paper having at least one thermosensitive coloring layer formed on one side. After performing thermal recording on the thermosensitive coloring layer with a thermal head, the thermochromic layer is irradiated with ultraviolet rays having a wavelength range peculiar to the thermosensitive coloring layer by a fluorescent lamp for light fixing to lose the coloring ability. Such thermal recording papers are stored in a stacked state in a paper cassette, and the paper cassette is loaded into a cassette loading chamber of the thermal printer.

[0003]

In the case of continuous printing with the above-described thermal printer, the fluorescent lamp for light fixing is continuously turned on, so that the temperature inside the printer increases due to the heat of the fluorescent lamp. This heat propagates through the frame and other parts of the printer body and raises the temperature inside the cassette loading chamber.
The temperature of the sheet cassette loaded in the cassette loading chamber is raised. As a result, the heat-sensitive recording paper housed in the paper feed cassette is warmed, and the moisture content of the heat-sensitive coloring layer of the heat-sensitive recording paper decreases. Since the heat-sensitive coloring layer changes its coloring characteristics depending on the water content, the heat-sensitive recording paper having a reduced water content of the heat-sensitive coloring layer cannot be colored to a desired density even when heat energy corresponding to image data is applied. .

SUMMARY OF THE INVENTION It is an object of the present invention to provide a paper cassette and a thermal printer in which the temperature of thermal recording paper is prevented from rising.

[0005]

In order to achieve the above object, a paper feed cassette according to the present invention is inserted into and removed from a cassette loading chamber.
The cassette body of the paper feed cassette to be used has a double structure. Also, attach a cooling fan to the cassette body,
Cooling air is blown to the cassette body.

According to the thermal printer of the present invention, a cooling fan is mounted in a cassette loading chamber for loading a paper feed cassette.
The cooling air is blown to the sheet cassette in the cassette loading chamber.

[0007]

According to the present invention, since the cassette body of the paper feed cassette has a double structure, heat from the printer body is cut off, and the temperature of the thermal recording paper stored in the cassette body is prevented from rising. Therefore, the water content of the thermosensitive coloring layer does not decrease and the coloring properties do not change.

In addition, since a cooling fan is attached to the cassette main body and a cooling air is blown to the cassette main body, the temperature rise of the thermal recording paper stored in the cassette main body is prevented. Therefore, the water content of the thermosensitive coloring layer does not decrease and the coloring properties do not change.

In addition, since a cooling fan is mounted in the cassette loading chamber and cooling air is blown to the sheet cassette loaded in the cassette loading chamber, the temperature rise of the thermal recording paper stored in the cassette body is prevented. You. Therefore, the water content of the thermosensitive coloring layer does not decrease and the coloring properties do not change.

[0010]

1, a paper feed cassette 10 has a double structure of an inner cassette body 12 for storing laminated thermal recording paper 11 and an outer cassette body 13 for rotatably storing the inner cassette body 12. Has become. Protrusions 13a to 13e are formed on the inner wall of the outer cassette body 13, and a gap 1 is formed between the inner cassette body 12 and the outer cassette body 13.
5 are formed. Heat from the outside can be blocked by the air layer in the gap 15. The thermosensitive recording paper 11 is, for example, a monochrome thermosensitive recording paper in which a thermosensitive coloring layer of one color and a protective layer are provided on a PET support.

The cassette loading chamber 18 for loading the paper cassette 10 is provided with a lift lever 21 for pushing up the inner cassette body 12 and pressing the thermal recording paper 11 against the paper feed roller 19 during paper feeding. When the paper cassette 10 is inserted into the cassette loading chamber 18, the lift lever 21 is inserted between the outer surface of the bottom plate of the inner cassette body 12 and the inner surface of the bottom plate of the outer cassette body 13 through a hole formed in the outer cassette body 13. Is done. The lift lever 21 is driven by a pushing portion 22.

When the paper is fed, the heat-sensitive recording paper 11 is
, The first thermal recording paper 11 from the top is pushed out toward the paper feed passage 24. The heat-sensitive recording paper 11 is sent to a print unit 25 through a paper feed path 24. The printing unit 25 is, for example, a monochrome line printer that performs recording by relatively moving the thermal recording paper 11 in the sub-scanning direction. The printer unit 25 is provided with, for example, a platen drum. A thermal head is arranged on the outer periphery of the platen drum at a thermal recording position of the thermal recording paper 11, and an optical fixing device is arranged downstream of the thermal head. The thermal head 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 heat-sensitive recording paper 11 has its leading end fixed to the peripheral surface of the platen drum via a clamper. As the platen drum rotates, the heat-sensitive recording paper 11 is wound around the peripheral surface of the platen drum, and upon reaching the recording position, a thermal image is used to thermally record a video image or the like. Thereafter, the heat-sensitive recording paper 11 is irradiated with ultraviolet rays by an optical fixing device, and the heat-sensitive coloring layer is optically fixed. The fixing of the leading end of the heat-sensitive recording paper 11 on which light has been fixed is released, and the recording paper 11 is discharged.

When printing is continuously performed by the thermal printer configured as described above, the lighting time of the optical fixing device becomes longer, and the temperature of the printing section 25 rises. The heat from the printing unit 25 is also transmitted to the cassette loading chamber 18 via a frame or the like of the printer main body, and the temperature of the cassette loading chamber 18 increases. Although the outer cassette 13 is heated as the temperature of the cassette loading chamber 18 rises, the temperature of the inner cassette body 12 hardly rises due to the air layer in the gap 15. Therefore, the thermosensitive recording paper 11 stored in the inner cassette main body 12 is not heated, so that the coloring characteristics of the thermosensitive coloring layer do not change.

In FIG. 2, the sheet feed cassette 30 has a cooling fan 33 attached to the outer surface of the bottom plate 32 of the cassette main body 31 to cool the sheet feed cassette 30. At the position of the cassette loading chamber 34 facing the cooling fan 33, a number of ventilation holes 34a for taking outside air into the cassette loading chamber 34 are provided. Further, a temperature sensor 35 is attached to the bottom plate 32 of the cassette main body 31, whereby the temperature inside the cassette main body 31 is detected. Based on this temperature information, the cooling fan 3 is controlled so that the temperature inside the cassette main body 31 is kept constant.
3 is controlled.

The driving control of the cooling fan 33 is performed on the printer main body side of the thermal printer. For this purpose, a connector 37 for the cooling fan 33 and the temperature sensor 35 is provided on the front plate 36 of the cassette main body 31, and a connector 38 corresponding to these is provided in the cassette loading chamber 34. When the sheet cassette 30 is inserted into the cassette loading chamber 34, the connectors 37 and 38 are connected, and the cooling fan 33 and the temperature sensor 35 of the sheet cassette 30 are connected to the control unit 39 in the printer main body via these connectors. The control unit 39 processes the temperature information of the temperature sensor 35 and controls power supply to the cooling fan 33. Even if the use of the thermal printer is interrupted for a while, the temperature in the cassette main body 31 is kept constant unless the paper cassette 30 is inserted into the cassette loading chamber 34 and the printer main body is turned off. As a result, the coloring characteristics of the thermosensitive coloring layer of the thermosensitive recording paper 11 do not change, and there is no need to readjust the print density.

In FIG. 3, the thermal printer 40 is
A cooling fan 42 is attached to the lower part of the cassette loading chamber 41 so that the sheet cassette 43 loaded in the cassette loading chamber 41 is cooled from the bottom side. In order to efficiently take in the cooling air from the cooling fan 42 into the cassette main body 44 of the paper feed cassette 43, a large number of ventilation holes 45a are formed in the bottom plate 45 of the cassette main body 44. Note that, behind the cooling fan 42, a number of ventilation holes 46 for taking in outside air are formed.

A temperature sensor 47 is mounted on the upper part of the cassette loading chamber 41, and the driving of the cooling fan 42 is controlled based on temperature information output from the temperature sensor 47. As a result, the temperature of the thermal recording paper 11 stored in the cassette body 44 is kept constant, and the coloring characteristics of the thermal coloring layer of the thermal recording paper 11 do not change even during continuous printing. Further, even if the use of the thermal printer is interrupted for a while, the temperature in the cassette body 44 is kept constant unless the power supply of the printer body is turned off, so that it is not necessary to readjust the print density.

The temperature sensors 35 and 47 may be humidity sensors, and the cooling fan may be controlled based on the humidity information to keep the humidity in the cassette body constant.

In the embodiment described above, the present invention is applied to a monochrome thermal printer. However, it goes without saying that the present invention may be applied to a color thermal printer. In this case, a color thermosensitive recording material in which three thermosensitive coloring layers are sequentially formed is used, and two kinds of lamps having different wavelengths of ultraviolet rays are arranged in the printing section.
The two heat-sensitive coloring layers are optically fixed after the thermal recording. Further, the printing unit is an example of a line printer that records by thermally moving the thermosensitive recording paper in the sub-scanning direction. However, the present invention is not limited to this. The present invention can also be applied to a serial printer for recording.

[0021]

As described above, according to the paper feed cassette of the present invention, since the cassette main body which is inserted into and removed from the cassette loading chamber has a double structure, the heat of the optical fixing device is cut off and continuous printing is performed. At times, the temperature rise of the thermal recording paper is prevented.
Therefore, since the moisture content of the thermosensitive coloring layer of the thermosensitive recording paper does not decrease, the coloring properties of the thermosensitive coloring layer do not change. Further, since the cooling fan is provided in the cassette body, the temperature of the thermal recording paper is prevented from rising even during continuous printing, and the same effect can be obtained. Further, according to the thermal printer of the present invention, since the cooling fan is provided in the cassette loading chamber, it is possible to prevent the temperature of the sheet cassette loaded in the cassette loading chamber from rising, and to reduce the temperature of the thermal recording paper even during continuous printing. The coloring characteristics of the thermosensitive coloring layer can be kept constant. Further, even if the use of the thermal printer is interrupted for a while, the temperature in the cassette main body is kept constant unless the power supply of the printer main body is turned off, so that it is not necessary to readjust the print density.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a state in which a paper feed cassette having a double main body is loaded into a cassette loading chamber of a thermal printer.

FIG. 2 is an explanatory view showing a state in which a sheet cassette provided with a cooling fan in a cassette body is loaded into a cassette loading chamber of a thermal printer.

FIG. 3 is a schematic explanatory view of a main part of the thermal printer showing a state in which a sheet feeding cassette is loaded in a cassette loading chamber provided with a cooling fan.

[Explanation of symbols]

 10, 30, 43 Paper cassette 11 Thermal recording paper 12 Inner cassette body 13 Outer cassette body 18, 34, 41 Cassette loading chamber 31, 44 Cassette body 33, 42 Cooling fan 34a, 45a Vent hole 35, 47 Temperature sensor 39 Control Part 40 Thermal printer

Claims (3)

(57) [Claims] 1. A paper feed cassette for storing thermal recording paper, wherein a cassette body inserted into and removed from a cassette loading chamber has a double structure. 2. A paper feed cassette for storing thermal recording paper, wherein a cooling fan is attached to the cassette main body and cooling air is blown onto the cassette main body. 3. A thermal printer, wherein a cooling fan is attached to a cassette loading chamber for loading a paper cassette, and cooling air is blown to the paper cassette in the cassette loading chamber.