JPH01238959A - Thermal transfer circuit - Google Patents

Abstract

PURPOSE:To decrease influence to be given to a thermal condition of a heating element of a head by a method wherein a thermal condition regulation means performs heating by application of power of specified intensity by which thermal transfer is not carried out even to a heating element corresponding to a pigment not to be thermally trans ferred. CONSTITUTION:When a heating element electrocontrol means 2 reads a data of a pigment and judges it as a pigment to be thermally transferred, the means 2 performs thermal transfer of said pigment. Further, when the means 2 judges it as a pigment not to be thermally transferred, heating is performed by application of power of speci fied intensity by which thermal transfer is not carried out by a thermal condition regulation means 3. By decreasing thus difference in a thermal condition between a case where thermal transfer is performed and a case where thermal transfer is not performed, variation in a printing condition according to the number of pigments to be thermally transferred is decreased. Further, for pigments not to be thermally transferred, whether a pigment exists in a specified area near the pigment to be ther mally transfer or not is judged by a near thermal condition regulation means 4. When it exists in the area, heating is performed by application of power of specific intensity by which thermal transfer is not carried out. When it is judged not to exist in the area, heating is not performed.

Description

[Detailed Description of the Invention] [Summary] Regarding a thermal transfer circuit that displays an image on a heat sensitive body based on image data, the effect of the number of thermal transfer pixels on the thermal conditions of a heating element of a thermal transfer head of a thermal printer is reduced. A heating element that is provided for each pixel and generates heat when energized, and a heating element energization control that controls energization to each of the heating elements based on image data to display an image on a heat sensitive body. In the thermal transfer circuit having means, the heating element corresponding to the pixel that is not thermally transferred is also provided with a thermal condition adjusting means that heats the heating element by energizing it with a predetermined intensity that does not cause thermal transfer.

[Industrial application field]

The present invention relates to a thermal transfer circuit that displays an image on a heat sensitive body based on image data.

Arranging heating elements that form prints in dots (by passing a pulse current through the heating elements in accordance with the image data, an image is printed on a heat-sensitive material such as thermal paper, which is notorious for coloring due to heat) thermal printer
Conventionally, there has been a tendency for the density of a printed image to fluctuate depending on the number of adjacent pixels subjected to thermal transfer, and there has been a need for a technique to solve this problem.

[Prior art and problems to be solved by the invention]

In a thermal transfer head of a thermal printer, heating elements are arranged one-dimensionally so as to form dots with a predetermined print width. In accordance with the image data to be printed, a pulse current is applied to each of the one-dimensionally arranged heating elements, and the thermal transfer head is scanned in a direction perpendicular to the direction in which the heating elements are arranged on the thermal paper. By doing so, an image is printed on the thermal paper F.

However, in the conventional Unetsu 2 printer, for example,
When printing with a small number of pixels to be thermally transferred, such as a straight line, there is a problem in that as the ambient temperature decreases, the amount of wax melted on the thermal paper decreases, resulting in blurred printing.

To prevent such blurring, if you set a large amount of current to each heating element, when printing an area with a large number of pixels to be thermally transferred, the temperature will rise and the molten wax on the thermal paper will increase. Is the amount of the total too large? There was a problem that the 4 degree angle became too much, making it difficult to print with gradation.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a thermal transfer circuit that reduces the influence of the number of thermal transfer pixels on the thermal conditions of the heating elements of the thermal transfer head of a thermal printer. .

[Means to solve the problem]

FIG. 1 is a basic configuration diagram of the present invention. In this figure, ■
2 is a heating element, 2 is a heating element energization control means, and 3 is a thermal condition adjustment means.

The heating element 1 is provided for each pixel, and generates heat when energized.

The heating element energization control means 2 applies 1ffi 74. to each of the heating elements 1 based on the image data. is controlled to display an image on the heat sensitive body.

The thermal condition adjusting means 3 heats the heat generating elements corresponding to the pixels that do not undergo thermal transfer by energizing them with a predetermined intensity that does not cause thermal transfer.

[Operation] FIG. 3 is a diagram showing the operation procedure in the first embodiment of the present invention. In step St, read the pixel data,
If it is determined in step S2 that the pixel should undergo thermal transfer, thermal transfer is performed on the pixel in step S3. For pixels that do not undergo thermal transfer, step S
In step 4, the thermal condition adjustment means 3 provided according to the present invention conducts electricity with a predetermined intensity that does not cause thermal transfer to heat the substrate.

In this way, the difference in thermal conditions between when thermal transfer is performed and when thermal transfer is not performed is reduced, so that fluctuations in printing conditions due to the number of pixels subjected to thermal transfer can be reduced.

FIG. 4 is a diagram showing the operating procedure in the second embodiment of the present invention. In step S1, read the pixel data,
If it is determined in step S2 that the pixel is to be thermally transferred, then step S3 is performed: thermal transfer is performed on the pixel. For pixels that are not to be thermally transferred, in step S5, the nearby thermal condition adjusting means 4 provided according to the second embodiment of the present invention determines whether the pixel exists in a predetermined area near the pixel to be thermally transferred. is determined, and if it exists in the area, it is heated by performing 1ill electricity of a predetermined intensity without thermal transfer in step S3. Further, if it is determined in step S5 that the predetermined area ζ near the pixel to which the pixel is to be thermally transferred does not exist, no heating is performed.

Therefore, according to the second aspect of the present invention, since heating is performed to adjust the thermal conditions only in a predetermined area in the vicinity that affects the thermal conditions of the pixel to which thermal transfer is performed, the power consumption for the heating is reduced. can be reduced.

〔Example〕

FIG. 7 shows the arrangement of heating elements on a thermal transfer head of a thermal printer.

FIG. 7 shows heating elements 111+ 1zl+ ""1+++t+ 1+ arranged in a total printing width of 4096 dots.
z+ ltz.

...1@t, ...1111+ 1211+ ...
・1.7 is 64 partial widths each consisting of 64 points (11r, 1z1°...1.,), (1,□,
1□2. ...1@t) ...(1,,.

1 th+ . . . 1 , , ).

Here, m=64. n=64.

The above division is performed in order to control these 4096 dot heating elements by arranging them in a matrix in order to control them using fewer drivers. This matrix arrangement is shown in FIG.

FIG. 5 is a schematic diagram of an embodiment of the present invention.

In FIG. 5, 111+1 IIM...1.
,． 1st eye.

1 zt+...11+1! ,”・1111+I
Rn+ ``' 1 was each a heating element arranged on the thermal transfer head of the thermal printer.

Furthermore, 21 is a row control register, 22. ．． 22g...
- 22 and 24 are respectively control signal lines of the row control register 21, 25 are column control registers, and 24. ．． 24□,...2
4. are column drivers 23□, each controlled by a corresponding control signal from the column control register 25.

23□,...23. ,,23°,23°,...23
-x,...23. ,.

231, . . . 231111 are row drivers controlled by the row control register 21, respectively. These structures correspond to the heating element energization control means 2 of the structure shown in FIG. 1 described above.

And 311+3! l+...31,3□,3
゜,...31,...31M, 3□7. ...3. ,
I is a current supply circuit for realizing the thermal condition adjustment means 3 according to the first embodiment of the present invention, and each of the heating elements 1□, 1□, . . . 1 ml+
11! + I Zt+ ...1.2. ...11a
+1! an...Supplies current to 1□.

In the configuration of FIG. 3, the output of the column control register 25 is
Column drivers 241, 241. ...247 is driven cyclically at a predetermined period. That is, each partial width of the thermal transfer head shown in FIG. 7 is scanned periodically.

The row control register 21 is connected to the column driver 24 . .

24□, . .

22□,...22. Output on top. This causes the row driver 23. ,,232. , ...23□, 231
□, 23□2. ...231. ...23,,,23.
,,,...23. ．． 1, those connected to the control signal lines 22□22□, . . . 22.1 to which valid signals are output are driven.

At this time, the heating elements connected to the column driver and row driver are simultaneously driven and are energized to generate heat and color the thermal paper. That is, thermal transfer is performed.

By the way, as mentioned above, each heating element 1, 1゜1□1.
...1. ,． 1. □、1□2. ...1st+...
・IIM.

127, . . . bow, n, respectively, are provided with current supply circuits 311+ 32I+ . . . 3□* 31 according to the present invention
1,3°,...3,! ,...31M+ 3za+
...3. ．． 1 is connected, and the column driver 2
41,24! ,...24. Each current supply circuit 31++ 32++...
30.3□, 3°,...3,2. ...31111
3 Zn* ... 3, the heating element L connected from
t, 1□,...1! l+ Lz+ 1tt+ ・
...11. ”・1111+ 1 !+%+ ”・・1
．． 1 is supplied with current. This current causes the heating element to generate heat to an extent that does not cause the thermal paper to develop color, that is, to the extent that thermal transfer is not performed, and also to minimize fluctuations in the thermal conditions of the heating element depending on the number of pixels to be thermally transferred. is set to

Here, if there is a partial width of the thermal transfer head in which there is no pixel to be thermally transferred in the image data to be printed, the column driver 24□2 corresponding to such partial width
4□, . . . , 24 are not driven even at the above-mentioned timing when they should be driven.

Thereby, it is possible to heat only the heating elements in the partial width of the thermal transfer head where the pixels to be thermally transferred exist, and to adjust only the thermal conditions of the heating elements in the vicinity of the pixels to be thermally transferred.

In other words, unnecessary power consumption can be avoided.

FIG. 6 shows a more specific configuration example of the current supply circuit, column driver, and row driver in the configuration of FIG. 5.

That is, in the configuration of FIG. 6, the row drivers 23□, 23□, . . . , 23 . ,,23□,23□2
．． ...231, ...231-, 23t-, ...2
311, and column drivers 241, 24g, . . . 2
4.1 receives a control signal at the base terminal and outputs O.
N, OFF transistor 26,,,26! ,,...
・26□, 26°, '26°, ... 26-z, ...
261.1.26t-,...26. , , and 27
．． ．． 27. ,...27. realized by Also,
Current supply circuit 311+ 3z+, ...”3 in Fig. 5
@l+ 3+z, 3zzt...' 3az,
""31R+ 3gm+...3. ．． 1 connects one end of the corresponding heating element and the high voltage source +■ to the resistor 3.
0. ,,30□.

...30. ,,30. ,,30°,...30-t,
...30. ,,30□7. ...It is realized by connecting by 30□.

In this way, the thermal transfer circuits of the first and second embodiments of the present invention are realized.

〔Effect of the invention〕

According to the first aspect of the present invention, it is possible to reduce the influence of the number of thermal transfer pixels on the thermal conditions of the heating elements of the thermal transfer head of a thermal printer.

Furthermore, according to the second embodiment of the present invention, the above effects can be achieved by
This can be achieved with less power consumption.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram of the first embodiment of the present invention, FIG. 2 is a basic configuration diagram of the second embodiment of the invention, and FIG. 3 is a basic configuration diagram of the first embodiment of the invention.
FIG. 4 is a diagram showing the operation procedure in the second embodiment of the present invention, FIG. 5 is a schematic configuration diagram of an embodiment of the present invention, and FIG. 6 is an embodiment of the present invention. and FIG. 7 is a diagram showing the arrangement of heating elements on the thermal transfer head. [Explanation of symbols] 1, lz, lxl, ~l-1.1. ! , 1°, ~11°~1. Yes, 10. ~l, 7...Heating element, 2...Heating element energization control means, 3...Heat condition adjustment means, 3. ,
．． 3□1゜～3m11+ 31! , 31! t~3.
z, ~31111+3! 11+ ~3.7...
Current supply circuit, 4... Neighborhood thermal condition adjustment means, 21...
- Row control register, 22. ．． 22! , ~22. . . . row control register 210 control signal line, 23. ,,23□,~
231°23, -, 232! , ~230. ~23I, 1
,23! , 1. ~23.1... row driver, 241,
24χ, ~24,1... Column driver, 25-... Column control register, 26.1.26□1. ~26. ．． ．． 26°. 26t, ~261. ~26. R, 26□1. ~26.
．． ．． 27. ．． 27□. ~277...transistor, 30□, 30□, ~3
00°3o+z, ao□2. ~30.2. ~30. f
i, aoza, ~30-...resistance. Image data Basic configuration diagram of the first embodiment of the present invention Fig. 1 Basic configuration of the second embodiment of the invention Fig. 2 Showing the operating procedure in the first embodiment of the invention Fig. 3 Diagram showing the operation procedure in the second embodiment Configuration diagram of the embodiment of the present invention FIG. 6

Claims (1)

[Scope of Claims] 1. A heating element (1) that is provided for each pixel and generates heat when energized; and a heating element (1) that is provided for each pixel and that generates heat by controlling the energization to each of the heating elements (1) based on image data to generate heat on the heat sensitive body. In the thermal transfer circuit, the thermal transfer circuit includes heating element energization control means (2) for displaying an image, the thermal condition adjustment means heating the heating element corresponding to the pixel that is not thermally transferred by energizing it at a predetermined intensity that does not cause thermal transfer. A thermal transfer circuit characterized by providing (3). 2. A heating element (1) that is provided for each pixel and generates heat when energized, and a heat generating element that controls energization of each of the heating elements (1) based on image data to display an image on the heat sensitive body. In a thermal transfer circuit comprising an element energization control means (2), a nearby heat transfer circuit that heats only a predetermined region near a region where a pixel to be thermally transferred exists in image data by energizing a predetermined intensity without thermal transfer. A thermal transfer circuit characterized by being provided with a condition adjustment means (4).