JPS6049985A - Cleaning method for thermal head - Google Patents

Abstract

PURPOSE:To naturally clean a thermal head surface with a predetermined cycle, by a method wherein either one or both of a leading end part and a trailing end part of a thermal recording paper are provided with a cleaner part by which a thermal head is cleaned. CONSTITUTION:Printing on a rolled thermal recording paper 1 is performed by a process in which heater lines 8 pressed against the paper 1 are heated in accordance with printing information, and simultaneously, a platen 7 is rotated in the direction of an arrow (a) to feed the paper 1 in the direction of an arrow (b). After printing, the paper 1 is discharged onto a paper-discharging tray provided in the exterior of the thermal recorder, and is cut by a cutter incorporated therein or the like. In order to smoothen or make uniform the surface of the paper 1, the leading end part 1a of the paper 1 is subjected to calendering to provide the cleaner part 1b indicated by a shaded part.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a method for cleaning thermals in printing devices such as printers, facsimile machines, and copying machines.

Note that the term "thermal head" as used herein refers to a shuttle type head or a solid state scanning type head that prints on thermal paper.

(Prior art) Thermal paper is printed using a thermal head.
This is paper in which a mixture of a coloring material and a thermally conductive material is coated on roll paper and cut paper (paper cut to a standard size of 1σ1). Printing on this thermal paper is 80° to 20°
By bringing thermal paper into contact with the head surface (heater line) of a thermal head that has been heated to a high temperature of about 0°, the heat conductive material applied thereto melts, the coloring material reacts, and color development occurs. It will be done.

When printing is repeatedly performed on this thermal paper, the coloring material and paper dust melted during printing adhere to the thermal head and the surface and accumulate. As a result, a gap is created between the head surface and the thermal paper, resulting in poor adhesion between them, and the conduction of heat to the thermal paper is hindered, resulting in a decrease in image density and unevenness in the printed image. Image quality is reduced.

Therefore, in the conventional printing apparatus of the above type, the thermal head unit is periodically removed and the head surface is cleaned with a cloth soaked in a solvent such as alcohol.

However, in recent years, as the printing speed of thermal heads has become faster and the sensitivity of thermal paper has become more sensitive, the frequency of paper debris adhering to the head surface has increased.
The maintenance cycle for cleaning also tends to become shorter year by year. As a means of solving these problems, it has been known to clean the top surface by conveying a special cleaning sheet in contact with the thermal head. By using a special cleaning seal that was previously cleaned by hand, the work efficiency has simply been increased, and the maintenance work remains the same as in the past. It also had the disadvantage of being expensive.

(Object of the Invention) The object of the present invention is to naturally purify the thermal head surface in a predetermined cycle while the printing device is in operation.
The object of the present invention is to provide a method for cleaning a thermal head that does not require special maintenance work.

That is, in the cleaning method according to the present invention, a cleaner part is formed in advance in the so-called margin parts such as the leading edge and trailing edge of the thermal paper, and the cleaning part is applied to the thermal of the thermal paper during the zero character process. The head surface is cleaned by the rubbing action.

(Structure of the Invention) FIG. 1 is a schematic diagram showing an example of a printing device in which the present invention is implemented.

In FIG. 1, a roll of thermal paper (hereinafter referred to as thermal roll paper 1) is rotatably supported on a roll shaft 2. As shown in FIG. The leading end portion 1a of the thermal roll paper 1 is guided through a guide roller 3 into a sheet path 5 formed by a pair of guide plates 4, and is brought into pressure contact with a thermal head 6 and its head surface 6a by a rotating platen. It is held between 7.

A heater line 8 as shown in FIG. 2, for example, is formed on the front surface 6a of the thermal head 6, and the platen 7 faces a portion where the heat-sensitive roll paper 1 is brought into pressure contact with the heater line 8.

As is well known, printing on the thermal roll paper 1 is performed by heating the heater line 8 in pressure contact with the paper in accordance with the printed information.
At the same time, the platen 7 rotates in the direction of the arrow a and conveys the thermal roll paper 1 in the direction of the arrow. After printing, the thermal roll paper 1 is delivered onto a paper discharge tray (not shown) outside the apparatus, and is cut by an operator or a built-in cutter. By the way, a leaner portion 1b is formed at the leading end portion 1a of the above-mentioned thermal roll paper 1, as shown by hatching in FIG. 3, for example.

This cleaner section 1b applies, for example, a clogging calendering process to only the leading edge of the roll paper, which is known as one of the manufacturing processes for conventional heat-sensitive roll paper, in order to smooth and make the surface of the roll paper uniform. It is formed by leaving the pigment in the tip portion unprocessed and in the form of coarse particles. In other words, there is usually a difference of several tens of seconds (measurement unit) in smoothness between paper whose surface is coated with pigment and calendered, and when it is untreated. This method takes advantage of the roughness of the surface of untreated paper.

Further, the cleaner portion 1b may be formed by attaching a separately processed cleaning sheet to the leading end of a conventional ordinary heat-sensitive roll paper.

The cleaning sheet may be made of pigments that are equivalent to or similar to conventional thermal paper pigments, such as titanium oxide or striped carbonate, or artificial corundum, silicon carbide, chromium carbide, or chromium oxide, which have higher cleaning effects. The pigment applied to the entire sheet is used.

Alternatively, the cleaner portion 1b may be formed by directly applying the pigment described above to the leading end portion 1a of the heat-sensitive roll paper 1.

As described above, since the cleaner portion 1b is formed at the leading end portion 1a of the thermal roll paper 1 in FIG. 1, when the platen 7 rotates and the leading end portion 1a is conveyed in FIG. The cleaner part 1b moves while rubbing against the head surface 6a of the thermal hemotor 6 and the heater line 8. Therefore, as the leading end portion 1a of the roll paper passes through, the coloring material, paper powder, dust, etc. adhering to the head, surface 6a, heater line 8, etc. of the thermal head 6 are removed by the polishing action of the cleaner section 1b, and the thermal head 6 cleaning is performed. As for this cleaning operation, the heater line 8 of the thermal head 6 may not be heated, and the cleaning may be performed only by the rubbing action against the head surface 6a by feeding the thermal roll paper 1. It is also possible to clean the heater line 8 by performing a Baber foot without heating it using the heater line 8. Here, when cleaning is performed with the heater line 8 heated as in the case of Ago-Nagisa, the coloring material and paper powder deposited on the head surface 6a are melted by the imprint heat, so that The cleaning effect is improved.

By the way, in the above-mentioned embodiment, an example was shown in which the cleaner part 1bi was formed on the leading end of the thermal roll paper 1, but the thermal paper to which this invention is applied is limited to roll paper, and cut paper cut into sizes. (hereinafter referred to as thermal cut paper).

Further, as the part forming the cleaner part of the thermal paper, for example, as shown in FIG. 4, only the rear end portion of the thermal roll paper 1, or as shown in FIG. A groove portion lb may also be formed.

In addition, as shown in FIGS. 6 to 8, thermal cut paper 1
A cleaner part], bk may be formed at the leading end, rear end, or both end parts of 0.

Furthermore, in the case of heat-sensitive cut-paper 10, all the laminated sheets may be formed with the above-described leaner portion 1b. For example, as shown in FIG. 9, the laminated sheet)
1.00, or the lowest sheet of the laminated sheet 100 as shown in FIG.
As shown in the figure, a heat-sensitive member having a cleaner portion 1b may be placed on each of the uppermost and lowermost sheets of the laminated sheet 100. In addition, in the case of heat-sensitive cut paper, a sheet with a cleaner section may be inserted in advance for each predetermined number of sheets so that the head is cleaned after a certain number of sheets have been printed. .

(Effects of the Invention) As described above, according to the present invention:C, the head surface is sequentially cleaned during the normal printing operation without removing the thermal head. This eliminates the need for maintenance and provides stable image quality throughout the use of the device.8 This also makes it possible to reduce the total cost of the device, including maintenance services.

In addition, in the printing apparatus shown in the drawing, the head surface adhesive IJ-ning is performed once every time the thermal roll paper is replaced, and the cleaning cycle is set depending on the length of the thermal roll paper. In other words, for normal thermal roll paper, the length is 530m, 100m or 2001m.
It will be cleaned every T1.

On the other hand, in the case of heat-sensitive cut paper (J-), the cleaning cycle can be freely selected depending on the arrangement of the sheet having the cleaner section.

In particular, in the case of sorting paper that has cleaner parts at both ends of a single sheet, such as the heat-sensitive paper shown in Figure 88, the print head surface is exposed twice, before the start of printing and once after the end of printing. Is this kind of sheet for each laminated sheet) to be cleaned? If you use it, you can get extremely stable image quality.

Note that since the cleaner portion is formed in a blank area of the thermal paper that does not contribute to printing, it does not interfere with the printed image.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of a printing device in which the present invention is implemented, FIG. 2 is a bottom view of a thermal head in the above device, and FIG. 3 is a perspective view of a thermal roll paper used in the above device. 4 and 5 are schematic side views showing other examples of heat-sensitive roll paper, FIGS. 6 to 8 are perspective views showing examples of heat-sensitive cut paper, and FIGS. 9 to 11 are examples of laminated sheets. FIG. 1...Thermal roll paper, 6...Thermal head, 1b.
・Cleaner part, 1o...Thermal cut paper, 1oo...
Laminated paper. %4 Ward] h %8Sen%D1 Illusion-1q

Claims (1)

[Claims] 1. Cleaning the thermal head by forming a cleaner part on one or both of the leading edge and trailing edge of the thermal paper on which data is written using the thermal head. A method for cleaning a thermal head characterized by: 2. The cleaning method according to claim 1, wherein the thermal paper is roll paper. 3. The cleaning method according to claim 1, wherein the thermal paper is cut paper. 4. The thermal paper is a laminated cut paper of a large number,
2. The cleaning method according to claim 1, wherein a portion of the cleaner is provided for each sheet. 5 The thermal paper is a laminated cut paper of a large number,
2. The cleaning method according to claim 1, wherein a part of the cleaner is formed only on one or both of the uppermost and lowermost sheets.