JPS60180860A - Thermal transfer recording system with tone - Google Patents

Abstract

PURPOSE:To represent many tones and color tones in one picture element by a method in which one picture element is made up of plural dots, a tonal ink sheet with plural colors is superposed on the same picture element, and energy to be applied to each dot is differentiated in three stages or more. CONSTITUTION:One picture element M is divided into 4 dots by each dot of M1-M4. Using a tonal ink sheet in which 4 kinds of colors yellow, Magenta, cyanin, and black are formed in a striped shape, density values more than 3 values are displayed by differences in energy to be applied to each dot. The arranging pattern of the energy values of dots in one picture element when representing the same tonal degree of plural color ink sheet is differentiated, and each dot is alloted from low density values to high density values.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a thermal transfer recording method using a thermal head to express 11 ill, and in particular, to express a large number of gradations and tones by using a gradable ink sheet. The present invention relates to a thermal transfer recording method using Nv14.

(Prior Art) In recent years, it has become desirable to use printers (hard copy devices) for computer terminals to print, for example, color monitor image information with intermediate II (shades) such as computer graphics in high quality. ing.

As the above-mentioned printers, six-pole printing devices such as wire tod type, inkjet type, shuttle type, and thermal transfer type have been developed.

It is well known that thermal transfer printing devices are widely used because they have a simpler mechanism, faster recording speed, and are easier to handle than the other printing devices mentioned above.

The principle of this transfer is as shown in FIG.
is caused to travel in the direction of force indicated by arrow A'.

The ink sheet 3 is an ink sheet that enables gradation expression, and is made of, for example, a polyester film with a thickness of 10 μl,
A heat-melting ink layer 6 having a two-layer structure with a stepped wax layer on top is formed by coating a base material 5 made of a polymer film such as a polycarbonate film.

In the transfer printing process, when a predetermined amount of current is passed through the thermal head 2 to generate heat, the ink layer 6 on the ink sheet 3 at the position corresponding to the thermal head 2 is dissolved in response to the generated heat, and the recording paper is Transferred to 4.

Further, the thermal head 2 is, for example, a line type, that is, it is configured with heating elements arranged in a line in the width direction of the rotating roller 1 and the recording paper 4, and the current flowing through each heating element is controlled to form one line. After printing dots, the rotary roller 1 is rotated to print the next line, and this process is repeated one after another to print color monitor image information, etc. consisting of desired characters and figures on the recording paper 4. It is.

7 shows ink transferred from the ink sheet 3 to the recording paper 4.

As means for expressing halftones of image information on a color monitor or the like using this thermal transfer recording device, for example, a halftone method and a dither matrix method have been proposed.

Taking the dither matrix method as an example, this method uses 11iT11 elements as shown in Figure 2.
xn (for example, 2x2) matrix, and use coordinate information normalized within that matrix, and set the ma range of the image signal from O to 1, for example, the density of the image information is 1/8 - O dot in case of 3, 3
For /8 to 5/8, use O and 1 dot, etc.
It attempts to express halftones by sequentially filling in each dot corresponding to the density of the image signal.

Therefore, this method not only cannot obtain a large number of gradations unless n is large, but also, if n is large, the resolution of the recorded image information will be poor, so the details and contours of the image will be lost. The image becomes blurred and unclear, the naturalness of the entire image is impaired, and furthermore, the minimum dot is subject to the IIJ limit.
There are various drawbacks such as poor linearity of IIIJI.

There are various problems involved in performing high-quality printing using such a thermal transfer recording device, and for this reason, an overlapping method such as a pit plane method has been conventionally used. Attempts have been made to achieve high-quality printing using this method, but conventional methods including these have drawbacks such as difficulty in feasibility and reproducibility, and the impossibility of mass production on an industrial scale.

(Object of the Invention) The present invention has been made in view of the above-mentioned drawbacks of the conventional art, and its purpose is to solve the problem that when image information such as combinational graphics is transferred and recorded, a large number of images are included in the image information. In addition to expressing stable gradation and color tones, the details and contours of the image are clear, the resolution is high, and linearity can be reproduced with good I.Furthermore, it is easy to realize and reproduce, and can be mass-produced. It is an object of the present invention to provide a thermal transfer recording method with possible gradations.

(Structure of the Invention) In order to achieve the above object, the present invention provides a thermal transfer recording method in which one pixel is composed of a plurality of dots, and ink sheets of a plurality of colors are superimposed on the same pixel to perform transfer recording. Using a gradation ink sheet that can display three or more density values depending on the difference in applied energy to each dot,
The density value of each dot is displayed in 3 or more values, and 1 is used when expressing the same gradation scale of the ink sheet of multiple colors.
By making the one-energy one-value array patterns of dots in each pixel different and assigning each dot from a low density value to a high density value, it was possible to express a large number of gradations and tones in one pixel. The present invention provides a thermal transfer recording method characterized by the following.

(Embodiment) FIG. 3 is a dot matrix diagram constituting a pixel, which is an embodiment of the thermal transfer recording method for controlling gradation according to the present invention.
Figure 4 shows the gradation level (16m> vs. applied energy diagram, Figure 5)
The figure is an m-degree representation diagram for each color in J3 in FIG.

This dot matrix is as shown in Figure 3.
For example, one pixel M is Ml, M2 . The M3 and M4 dots are divided into four dots of 2.times.2, which are normalized and arranged in a square shape within a 71-rix, and the following explanation will be made using this matrix.

Further, the number of gradations of the gradation ink sheet is the same as that of the one using the j value (0 to 4), as shown in the energy diagram of application of gradation ink sheet in FIG. That is, the applied energy values shown in the figure are El, E2. The densities can be expressed in this order from E3 to E4, and the density values assigned to each dot in the matrix are shown as 0961 in order from lightest to darkest in the figure.

The gradation ink sheet used here is, for example, one in which four types of colors, yellow (Y), magenta (M), cyan (C), and black (B) are formed in a random pattern.

Therefore, when the energy value applied to each dot is set as described above and transfer recording is performed, the gradation level of one pixel is the fifth
(Y)(
For M), (C), and (B), each of the 16 gradations is sharpened.

The above transcription recording order is Y-+M→C→B1 or B4Y
-) It is repeated four times in the order of M→C.

Here, the method of expressing gradation will be explained with reference to each of the above figures.

First, the first time is assumed to be Y, and Y will be described below.

As shown in the figure (a), when the energy value applied to the dot M1 is El and the energy value applied to the other dots is zero, a gradation level of 1 is obtained, as shown in the figure (b). As shown in FIG.
As shown in , if the energy values applied to the drums M1 and M2 are E2 and El, respectively, the floor Wli
3 is obtained, and if the energy value applied to each dot is El as shown in the figure (d), a gradation level of 4 is obtained; If the energy value applied to the dot is E2 and the second energy value applied to the other dots is El, then 1lPi
Gradation level 5 is obtained, and if the energy value applied to dots M1 and M2 is E2 and the energy value applied to the other dots is El, as shown in the same figure (f), gradation level 6 is obtained. dot M1 as shown in the same figure (9).
．． M2. When the energy value applied to M3 is E2 and the energy value applied to other dots is El, a gradation level of 7 is obtained, and as shown in (h) in the same figure, the energy value applied to the square dots is When all the energy values are E2, a gradation level of 8 is obtained.

In this way, as shown in FIG. Each gradation is expressed by an energy value arrangement pattern set in such a way that different energy values are uniformly arranged within the matrix.

In the case of gradation 11111-2, the number of dots that cannot be filled in the matrix is minimized, and in the case of gradation 3, two dots adjacent to each other in the horizontal direction are selected as in gradation 2 to improve transferability. Prevents peeling during transfer.

After gradation level 4, fill in all the dots, maintain a relationship in which the energy values applied to each dot are as equal as possible, and create a relationship in which the same energy values are placed adjacent to each other in the matrix. Each gradation (16
gradations).

The second time is M. M is shown in Figure 5 (a) (b) ~ (o) (
The energy value array pattern of Y is set to 90 as shown in p).
By rotating clockwise by °, 1 of the above Y!
! The 161@ key is obtained in the same way as the i key expression.

The third time is C. C is shown in Figure 5 (a) (b) ~ (o) (
The energy value arrangement pattern of Y is 18 as shown in p).
Obtained by rotating clockwise by 0°.

The fourth time is B"'CB5. B is from Figure 5 (a) (b)
As shown in (o) and (p), the Y energy value array pattern is obtained by rotating the Y energy value array pattern clockwise by 2700 degrees.

As a result, the probability is that the number of dots remaining without being filled in is almost zero due to a set of four color transfer recordings, so when color image information with shading is transferred and recorded, many gradations and color tones are recorded. In addition, the naturalness of the entire image is emphasized without image adjustment or outlines becoming blurred or blurred, and furthermore, the restriction on the minimum dot is alleviated by matrix division, so the gradation can be improved. It has advantages such as good linearity.

FIG. 6 is an 8IIIJI expression diagram for explaining the second embodiment of the thermal transfer recording method having N tone according to the present invention.
, 2Similar to the first embodiment, 16 filji is used in each transfer process.
To change the tone, we layered this one again and doubled the number to 32111 for each color! It is configured to obtain the i key.

The above transcription record is Y(I)→Y(II)4M(1)4M
(TI)→C(I)→C(II)→B(I)→B(■)
, or B(I) → B(■) → Y(I) → Y (II
') 4M(I) 4M(II)→C(I)→C(ff) is repeated 8 times.

Gradation levels 1 to 16 are performed in the same manner as in the first embodiment in the step (1) for each color, and no energy is applied in the step (2). This is because the density created in one time is reproduced in one time in order to avoid density loss as much as possible when the image is transferred twice and transferred overlappingly. lli'5 furniture 17~
32 is shown in Figure 6 (17) (32') (However, the figure (22')
) to (31) are omitted and the first step ■
and the second step (2) is carried out in minutes G. Y will be described below.

As shown in the same figure (11), the energy value applied to dot M1 in the first process is E3, the energy value applied to other dots is zero, and the energy value applied to dot M1 in the second process is E3. When the energy value is E2 and the other energy value is E4, a gradation level of 17 is obtained, and as shown in (18) in the same figure, the dot M1 is
And the energy value applied to M2 is E2 and the energy value applied to the others is zero, and in the second step ■, the dot M
When the energy value applied to 1 and M2 is E2, and the energy value applied to the others is E4, a gradation level of 18 is obtained, and as shown in 6J in the same figure (19), in the first step ■ Dot M1. The energy value applied to M2 and M4 is E3, and the energy value applied to the others is zero, and the dot M1. When the energy value applied to M2 and M4 is E2, and the energy value applied to the others is E4, a gradation level of 19 is obtained, and the same figure (
As shown in 20), dots M1 and M2 are formed in the first process.
is applied to The energy value is E3, the energy value applied to other dots is E2, the energy value applied to dots M1 and M2 in the second step is E2,
When the energy value applied to the other dots is E3, the floor tJ corner 20 is obtained, and as shown in the same figure (21), the energy value applied to the dot M1 in the first step is E3, If the energy value applied to the other dots is E2, and the energy value applied to each dot in the second step (2) is E3, a floor FJ of 4 degrees 21 is obtained.

In this way, as shown in the figure (32), the energy value E4 is applied to each dot in the first J: step
Pi! At If, the energy value E4 is applied to each dot to obtain the floor wArg,32.

In this way, Y is divided into two steps, and similarly, M, C,
Regarding B, as in the first embodiment, FIG. 6 (11)
As shown in ~(32), the energy value array pattern of each color is 90% of the energy value array pattern of Y.
obtained by rotating clockwise by 180°, 2700°. As a result, by performing a set of 8 color transfer recordings, in addition to the advantages of the first embodiment, there is an advantage that the gradation level is doubled and the number of colors that can be expressed is increased by 23-8 times.

In this case, for example, 10%
Correction of the 81 degree loss can be performed at a stage before gradation conversion using these energy value array patterns. That is, it is not necessary to make the applied energy values different by, for example, 10% between the first step and the second step. As a result, the gradation level is 17
The linearity of optical reflection density at ~32 is ±1st order J
For example, a good optical reflection fiI1 degree vs. tone curve as shown in FIG. 7 can be obtained.

In addition, in the above embodiment, if peeling is likely to occur during the transfer of 11 degrees 1 (a), the steps shown in FIG. 5-(b), (d), and (e)
, (f), (l instead of Figure 8(b), (d), (0
), (f), <Q> (D like km fjl 11(a)
It is also possible to use an energy value array pattern that avoids the use of . Although this replacement increases the number of dots that cannot be filled in the matrix, since these are rotated 4 to 8 times and overlapped,
The probability of the dots remaining without being filled in is extremely low. In addition, in the above example, 11 degrees 1 (
When using an ink sheet that is extremely susceptible to peeling during transfer as shown in a), it is possible to use the ink sheet shown in Figure 9 (C) instead of Figure 5 (C).
It goes without saying that the energy value array pattern shown in ) may be used, and that other energy value array patterns can also be replaced.

Also, for the dot matrix that constitutes one pixel, n is 2
Although the explanation has been made using 4 dots of 2 x 2, it goes without saying that this dot matrix may generally be composed of a plurality of nm dots (n x m, where n and m are 3 or more). Although the ink sheet has been described using an ink sheet having five gradations, it goes without saying that the number is not limited to five and any number and density step may be set.

Furthermore, the types of colors are Y, M, and C.

Although the description has been made assuming that each of the four colors of B is transferred once or twice, the colors are not limited to this, and the type may also be four YVO colors, etc., and the number of transfers is also limited to these examples. It's not something you can do.

(Effects) As described above, according to the thermal transfer recording method having tone III according to the present invention, when performing transfer recording of image information having halftones such as computer graphics, the image information has a large number of stable F! ! In addition to expressing iH and color tone, the details and contours of the image are clear, the resolution is high, and linearity can be reproduced well.Furthermore, it is easy to realize and reproduce, and can be produced easily. It has the following features.

[Brief explanation of the drawing]

Figure 1 shows the principle of the thermal transfer recording device.
The figure is a matrix pattern diagram showing an example of a dither matrix pattern, and Figure 3 is a dot matrix diagram configuring a pixel, which is an example of the thermal transfer recording method for controlling gradation according to the present invention. , Figure 4 shows the gradation flI (1m
Fig. 5 is a graph showing the density of the first embodiment of djG applied to Fig. 4.
Fig. 7 is a density representation diagram showing the second embodiment of the thermal transfer recording method with we, Fig. 7 is an optical reflection 1m1a vs.
9 and 9 are other density expression diagrams in the first and second embodiments. 1... Rotating roller, 2... Thermal head, 3... Ink sheet, 4... Recording paper, M... Pixel. Patent Applicant: Victor Japan Co., Ltd. f 17 yen I Wholesale tJnKara J Direct 5E5 tb> (C) tl) (e> tf) tys tf
r>lc th l/J npti l#J tθ)
rp) 76 days-" (21) (32) 77 days 9 days rc> 78 mouths

Claims (1)

[Claims] In a thermal transfer recording method in which one stroke system is composed of a plurality of dots and transfer recording is performed by superimposing ink sheets of multiple colors on the same pixel, it is possible to achieve a dark color value of 3hfm or more by applying an energy value to each dot. Using a gradation ink sheet that can be displayed, the II value of each dot is displayed in three or more values, and the energy of a dot in one pixel when expressing the same gradation level of the ink sheet of multiple colors. The gradation is characterized in that it is configured to express a large number of gradations and color tones in one pixel by making each dot have a different value array pattern and assigning each of the dots from a low 11-degree value to a high 1-degree value. A thermal transfer recording method.