JPS61191161A - Picture recording method - Google Patents

Abstract

PURPOSE:To prevent the generation of a whitening between scanning lines of the magnetic head and to prevent the recorded picture is compressed by making the heating element in the edge part of the heating element row longer than other heating element in the row direction. CONSTITUTION:A thermal head TH, which arranges plural heating elements HE in a row in the upward and forward directions, is shifted and scanned in the right and left directions. At such a case, the width of the element HE of the edge part is a+alpha/2, the width of other intermediate element HE is (a), and the length of the whole of the heating element column l'=na+alpha [(n) is the number of heating elements.]. The symbol alpha is equivalent to the sending unevenness of paper due to the variance of the driving part, and the symbol alphais set to the maximum value of the sending unevenness or above. Thus, picture data for one line can be recorded on the recording paper in a state that the edge part in the line direction and the right-angled direction is expanded. Since the heating element at the external side is large in the thermal diffusion and easy to cool, the length of the heating element at the external side is made larger, the thermal capacity is made larger and the temperature of respective heating elements is made average.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image recording method in which an image is recorded by moving a recording head having an array of recording elements in a main scanning direction and moving a recording paper in a sub-scanning direction.

2. Description of the Related Art Thermal heads have been widely used as recording means for facsimile machines and the like.

Figure 1 shows the configuration (front view) of a conventional thermal head, in which a thermal head TH in which a plurality of heating elements HE are arranged in a vertical (vertical) row is moved horizontally (horizontally) to scan (
scan).

The heating element HE is configured to record image emotion on a thermal recording paper (not shown).

When the horizontal scan is completed, the head is moved to the original starting position and a new record of the thermal record, paper record, etc.
The recording paper is moved in the vertical direction so that its surface faces the thermal head, and then the recording operation is performed again.

゛However, with such a conventional thermal head:
As shown in FIG. 2, if the movement width of the recording paper 1 in the direction of the arrow 2 is not always constant, the recording width scanned vertically will be 3.4 mm.
There is a drawback that a gap 5 between the scanning lines is formed in the area sandwiched between the two.

Possible causes of this include pitch unevenness and eccentricity of the drive transmission member (not shown) that moves the recording paper 1, such as gears, eccentricity of the roller section, vibration of the belt, etc., but it is difficult to eliminate these causes. In the past, in order to eliminate this gap 5, the recording widths of the upper and lower scans overlapped slightly, but even so, if a white gap 5 sometimes occurs, the force may overlap. -99, OK, KA, □. :6°. Yo,
.

Since image quality with white areas is particularly noticeable, countermeasures against white areas were needed. Furthermore, if the recording widths of the upper and lower scans overlap, there is a drawback that the recorded image data is compressed in the vertical direction.

The present invention eliminates the above-mentioned drawbacks, and aims to provide an image recording method that does not produce blank areas between the scanning lines of the recording head and does not cause the recorded image to be compressed. .

In the conventional type thermal head shown in FIG. 1, the recording width in one scan is Jlt=na (where n is the number of elements), where a is the dimension of the plurality of heating elements HE. However, FIGS. 3(A) and 3(B) show a different embodiment of the present invention, in which the recording width sentence' is lengthened by α (that is, r=na+α), and the recording paper feed width is not changed in the sentence. .

This α corresponds to paper feeding unevenness due to variations in the drive unit, and it is desirable to set this α to a value equal to or greater than the maximum value of the feeding unevenness. In addition, in FIG. 3(A), the correction value width α is determined by the two heating elements HE located outside.
This is a case where the dimensions are lengthened by α/2 for each. Further, in FIG. 3(B), one of the upper and lower sides (the upper side in this embodiment) of the outer heating element HE is lengthened by the correction value width α.

In this way, by making the heating element in the i section of the heating element row longer than the other heating elements in the row direction, one line of image data can be printed onto the recording paper with the end portion expanded in the direction perpendicular to the line direction. Can be recorded.

In general, the outermost heating element in a row of elements has a large amount of heat diffusion and is easily cooled down, so to prevent this, increasing the heat capacity by increasing the length or area of the outer heating element is an effective way to prevent this. This is effective in making the heating element temperature uniform. This effect is particularly great in the embodiment shown in FIG. 3(A).

As described above, according to the present invention, no white areas are generated between the scanning lines of the recording head, and the recorded image is not compressed.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the configuration of a heating element of a conventional thermal head, FIG. 2 is an explanatory diagram showing a recording state by the conventional thermal head, and FIG. 3(A). (B) is a front view showing different embodiments of the thermal head of the present invention. T H---Thermal head HE---1 Heat generating element 3 diagram (A) (B)

Claims (1)

[Claims] The recording head, which records one line of image data with its end expanded in the direction perpendicular to the line direction, is moved in the main scanning direction with respect to the recording paper to record one line. An image recording method characterized in that the next line is recorded by moving the paper in the sub-scanning direction by an amount equal to the recording width when recording without expanding the edge of the image data.