JPS62128275A - Thermosensitive recording and controlling method - Google Patents

Abstract

PURPOSE:To prevent the deterioration of a resolution according to a combined pattern of recording data by examining the presence absence of the recording data in a picture element adjacent to a main scanning direction of a noted picture element and controlling the number of energizations of a heating element for recording the recording data in the noted picture element according to the result. CONSTITUTION:A comparison circuit 1, only when both side recording data HD(m-1), HD(m+1) of the noted picture element (m) are not 'black', outputs adjacent picture element referring data HDD of '1' and outputs the referring data HDD of '0' when both the side picture elements are 'black'. The recording data DH and the referring data HDD of one line stored in the respective memory areas ME0, ME1 of a memory 4 are successively read serially for the picture element unit and transferred to the heating element. In this case, on the noted picture element, in which both the side adjacent picture elements are 'black', the recording is performed only by the recording data HD and the adjacent picture elements are prevented from being large in a coloring formation due to heating.

Description

[Detailed Description of the Invention] Technical Field of the Invention] The present invention relates to a thermal recording control method for a thermal recording device,
Specifically, the present invention relates to a method for improving image quality when the density of heating elements is increased.

[Technical Background of the Invention] As is well known, a thermal recording device generates heat in each heating element corresponding to a pixel in the main scanning direction of a recording medium according to recording data for each pixel, and the thermal recording device slides into contact with the heating element. Characters and images are recorded by coloring a recording medium such as paper or an ink donor sheet.

In such @thermal recording devices, the resolution of the image is determined by the size of each heating element.

[Problems with the unscrupulous technology] However, when the shape of the heating element is made smaller and the density is increased in order to further improve the resolution, pixels 5 adjacent to each other in the main scanning direction are exposed to thermal effects from the heating element. The degree of exposure to W increases, and the resolution changes depending on the pattern of the recorded image.
Although there is a problem of deterioration of image quality, for example, when pixels at positions n+5 to n+7 are colored as indicated by diagonal lines as shown in FIG. 4(a), the pixels at position n+2 are adjacent to each other. Since the heating element of the pixel does not generate heat, the pixel develops color depending only on its own heat generation. However, n+5~n
Regarding the pixel at the +7 position, since the heating elements of each pixel mutually receive thermal influence, the coloring shape is the fourth one.
As shown by diagonal lines in Figure (b), the amount of heat generated is larger than when each heating element is made to generate heat individually, and the resolution is lowered. As a result, the resolution differs between parts where the colored pixels are continuous and parts where the colored pixels are not continuous, resulting in a significant deterioration of the overall image quality.

[Object of the Invention] An object of the present invention is to provide a thermal recording control method capable of eliminating the above-mentioned drawbacks, preventing a decrease in resolution due to combination patterns of recorded data, and recording high-quality images. shall be.

[Summary of the Invention 1 The present invention checks the presence or absence of recording data in pixels adjacent to the pixel of interest in the main scanning direction, and controls the number of times of energization of a heating element for recording the recording data in the pixel of interest according to the result. This achieves the above objective.

[Embodiment of the Invention] FIG. 1 is a circuit diagram showing an embodiment of the present invention, in which recording data HD that is serially input corresponding to each pixel in the main scanning direction is input to a comparator circuit 1, and , are sequentially input to first and second delay circuits 2 and 3 having a delay time equal to the transfer time of one pixel.

Here, if the recording data HD input at the current time is the recording data regarding the pixel m+1 next to the pixel of interest m, then the recording data output from the first delay circuit 2 is the recording data of the plane of interest l?
4m, and the second delay circuit 3
The recording data outputted from is recording data regarding pixel m+1, which is one pixel before the target plane in.

Therefore, the comparison circuit 1 records data HD of pixels m-1 and m+1 on both sides of the pixel of interest m which has been removed in this way.
(m-1), HD (m+1) and the recording data HD (m) of the pixel of interest m are compared with each other, and for example, it is set to "1" only when both pixels on both sides of the pixel of interest m are not 'black'.
If both adjacent pixels on both sides are "black", reference data HDD of "0" is output.

This adjacent pixel reference data)-IDC is created for each pixel in the main scanning direction, and is stored in the recording data storage area MEO and the reference data storage area ME1 of the memory 4 together with the recording data HD (m) of each pixel.

1 stored in each storage area MEO and MEL of memory 4
The recording data HD and reference data HDD for the line are stored in the second
As shown in Figure (a), the recording data H of the new recording line
In synchronization with the start of input of D, the data is serially read out pixel by pixel and transferred to a heating element (not shown). Then, when the transfer of the recording data HD is completed, the reference data HD
Similarly, D is serially read out pixel by pixel and transferred to the heating element.

At this time, when the transfer of one line of recording data 1-(D is completed, the recording enable signal EN for energizing the photothermal element is turned on for a time T1 as shown in FIG. 2(b). Recording is performed using the recording data HD.Furthermore, even when the transfer of one line of the reference data HDD is completed, the recording enable signal EN is kept on for 12 hours, and recording using the reference data HDD is performed.

That is, the recording of the current recording line is completed by recording both the recording data HD and the reference data HDD.

However, in this case, when the pixels m-1 and m+1 on both sides of the pixel of interest m are both "black", the reference data HDD is )-1[)D='''0''. For this reason,
For a pixel of interest whose neighboring pixels are both "black", recording is performed for time T1 using only the recording data HD.

Therefore, compared to when one of the adjacent pixels is "black" or when both adjacent pixels are "white", the heat generation energy is substantially reduced by the equivalent of T2 time. This suppresses the colored shape from increasing due to heat generation of adjacent pixels.

This eliminates variations in resolution due to combination patterns of recording data, making it possible to record images of high quality.

6. Reference data 1-IO[)+ as above, 3rd
As shown in the figure, it can be easily made by combining Noah games 1 to 1o and an AND gate 11.

In this case, only when both adjacent pixels are 'white',
The reference data HDD is set to "'1", and the recording of the pixel of interest is T.
Try to do it twice at 1 hour and 12 hours, and in other cases T1
It may be done only once in an hour.

[Effects of the Invention] As explained above, according to the present invention, the front right of recorded data in pixels adjacent to the pixel of interest in the main scanning direction is checked,
Since the number of times of energization of the heating element for recording the print data in the pixel of interest is controlled according to the result, it is possible to prevent a decrease in resolution due to the combination pattern of the print data. As a result, it becomes possible to further increase the density of the heating elements of each pixel.

In addition, since one recording operation is completed by generating heat multiple times, the heat generated energy per time can be reduced, so there is less thermal influence on adjacent pixels, which not only improves resolution but also shortens heat dissipation time. It is also possible to promote the improvement of the speed described in 9 above.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, FIG. 2 is a time chart for explaining the recording operation of the embodiment, FIG. 3 is a diagram showing an example of a comparison circuit for forming reference data, and FIG. 4
The figure is a combination pattern diagram of recorded data for explaining the problems of the prior art. 1... Comparison circuit, 2, 3... Delay circuit, 4... Memory, 10... NOR gate, 11... AND gate.

Claims (1)

[Claims] In a recording control method for a thermal recording device having heating elements corresponding to the number of pixels in the main scanning direction of a thermal recording medium, the presence or absence of recording data in pixels adjacent to a pixel of interest in the main scanning direction is checked, A thermal recording control method characterized by controlling the number of times of energization of a heating element for recording recording data in a pixel of interest according to the result.