JPH11208005A - Image recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for recording images which causes no shift of recording faces and copes with ink films of different color counts. SOLUTION: An ink of a plurality of colors is applied in parallel to a longitudinal direction of an ink film 2 and pressed in touch with a recording paper by a thermal head 1 having a plurality of heat-generating resistance bodies H, S of a nearly equal length in a breadthwise direction of the ink film 2 and arranged in a row. Electricity is supplied according to color data corresponding to the color of the ink film 2 in touch with the heat-generating resistance body H. When the recording paper is transferred in the breadthwise direction of the ink film 2 every time the thermal head 1 scans, a transfer pitch of the recording paper is set to be an integral multiple of a pitch of the heat-generating resistance bodies H, S.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording method for transferring and recording ink applied to an ink film on recording paper by a thermal head, and more particularly to an image recording method for obtaining a color image.

[0002]

2. Description of the Related Art In recent years, a thermal head using an ink film coated with three color inks of yellow (Y), magenta (M), and cyan (C), or four colors of ink with black (K) added thereto. An image recording method has been widely used in which a heating resistor is selectively energized to sequentially transfer ink of each color onto recording paper to obtain a color image.

FIG. 4 is a diagram showing a conventional image recording method, in which reference numeral 11 denotes a thermal head which is selectively heated and driven by an image signal, and reference numeral 12 denotes a film width in the order of (Y), (M) and (C). Ink film applied one by one face by face,
Reference numeral 3 denotes a recording paper, and 4 denotes a platen roller. An ink film 12 between the thermal head 11 and the platen roller 4
And the recording paper 3 are movably overlapped and pressed against each other, and the color material on the ink film 12 is thermally melted or sublimated on the recording paper 3 for printing.

As shown in FIG. 5, a thermal head 11 scans the recording paper in the width direction, and the recording paper 3 is conveyed in the longitudinal direction for each scan, and the ink film is applied one color at a time in a face-sequential manner. The packaged ink cartridge (not shown) is replaced every time printing of one color is completed.
In some cases, printing is performed by reciprocating the recording paper 3 in the longitudinal direction while scanning at the same time.

In the conventional example shown in FIG. 4, a thermal head 1 having a length equal to the width of the recording paper 3 to be used is used.
1 is required, and there is a problem that the thermal head 11 becomes larger and more expensive as the size of the recording paper 3 increases. In addition, as shown in FIG. 6, a cueing mark 6 for cueing is required for each color of the ink film 2, and there is a problem that control is complicated.

Further, the conventional example shown in FIG. 5 has a problem that it is difficult to reduce the printing time because the ink film 2 needs to be replaced for each color.

Further, both of the above-mentioned conventional examples require reciprocation of the recording paper 3 for the number of colors to be used, and require high recording paper conveyance accuracy to obtain good registration. Since misregistration degrades image quality, it is a very important point in this type of image recording method. In order to eliminate the deviation of the registration, for example, there has been proposed an apparatus in which a recording paper is transported using a roller having a fine unevenness formed on a metal surface.

[0008] In order to solve such problems,
There is an invention described in JP-A-5-345467. According to FIG. 7 showing the outline of the invention of the publication, three colors (red 7, blue 8, yellow 9) are formed in parallel on one ink film 2, and the thermal head 2
When the recording paper 1 makes one reciprocation, the recording paper 3 is fed by an amount corresponding to the width of the portion 10 where the transfer is performed.

[0009]

By the way, in the conventional example shown in FIG. 7, the transfer portion of the thermal head is colored 3
It is divided into three places corresponding to the primary colors, and the width of feeding the recording paper is determined to be the same as the width of the part where the thermal head transfers, so for example, the ink increases to four colors that add black to the three primary colors, There has been a problem that the thermal head and the recording paper transport mechanism itself must be modified when a plurality of colors including the three primary colors and the intermediate colors are added.
Also, when recording a monochrome image or text, an ink film coated with only black ink cannot be used, and black is reproduced with a mixture of three primary colors, which makes it difficult to improve quality and reduce costs. Even when an ink film coated with only black ink is used, it is difficult to increase the speed of printing because the portion where the thermal head is transferred is narrow.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide an image recording method capable of obtaining a high-speed, inexpensive and high-quality image and capable of coping with a change in the number of colors of an ink film. And

[0011]

In order to solve the above-mentioned problems, the present invention provides an ink film 2 in which a plurality of color inks are applied in parallel to the longitudinal direction of a tape-like film. Color data corresponding to the color of the ink film 2 in contact with the recording paper 3 by a thermal head 1 having a plurality of heating resistors H arranged in a line by substantially the same length as An image recording method for recording and forming a color image by energizing the heating resistor H and conveying the recording paper 3 in the width direction of the ink film 2 every time the thermal head 1 scans the recording paper 3 , The pitch at which the recording paper 3 is conveyed is set to the pitch P of the heating resistors H.
And an image recording method characterized by being an integer multiple of

2. The image recording method according to claim 1, wherein no current is supplied to the heating resistor in contact with the vicinity of the color boundary of the ink film.

Further, the number of colors of the ink applied to the ink film 2 is detected, and the number Hy, Hm, Hc of the heating resistors H to be energized per one color according to the detected number of colors and the recording paper 3 are determined. The image recording method according to claim 1, wherein a conveying pitch is changed.

Further, the number of colors of the ink applied to the ink film 2 is detected, and the number Hy, Hm, H of the heating resistors H to be energized per color is detected in accordance with the detected number of colors.
c, the number T of the non-energized heating resistors S and the recording paper 3
3. The method according to claim 2, wherein a pitch at which the paper is transported is changed.
And an image recording method described in (1).

Further, the number of scans of the thermal head 1 is N, and the maximum number of the heating resistors H per color is Hma.
x, the number of non-energized heating resistors S near one boundary of the color of the ink film 2 is represented by T, and the number of applied ink colors counted in the order of scanning by the thermal head 1 is represented by Z. Number h of heating resistors to be energized for each color
Is defined as h = {N− (Z−1)} Hmax− (Z−1) T (however, when h is a negative value, 0 is assumed, and the value of h does not exceed Hmax). An image recording method according to claims 2 and 4 is provided.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an image recording method according to the present invention will be described below with reference to FIG. The same components as those in the conventional example described above are denoted by the same reference numerals,
Description is partially omitted. As shown in FIG. 2, three color inks of yellow (Y), magenta (M), and cyan (C) are applied to the ink film 2 in three regions parallel to the transport direction of the ink film 2, and the ink is applied to a cartridge (not shown). Load it. Outside the cartridge, there is provided an identification means (not shown) for identifying the number of colors of the ink applied to the ink film 2 and the order in which the inks are arranged by the image recording apparatus main body. This can be achieved by providing a reflection plate, unevenness, or the like outside the cartridge, and detecting it with an optical sensor or switch on the main body side.
Note that the type of the ink cartridge may be manually set by a switch provided on the image recording apparatus main body side.

Then, as shown in FIG. 1, (Y),
The ink film 2 coated with the three color inks (M) and (C) is pressed against the recording paper (not shown) by the thermal head 1, and electricity is supplied to the heating resistor forming the thermal head 1, and the thermal head 1 is turned on. Each color is printed by scanning in the left-right direction of the drawing (referred to as main scanning). Thereafter, the thermal head 1 returns to the initial position before scanning, and the recording paper (not shown) is scanned upward by a predetermined width (called sub-scanning). At this time, the thermal head 1 (Y)
(M) and (C) are provided with energizing heating resistors H in a number corresponding to the width of each color. In addition, a predetermined number of non-energized heating resistors S are arranged at the boundary of each color.

Next, the printing operation will be described with reference to FIG. In order to form a color image using the ink film 2 coated with the three color inks of (Y), (M) and (C), it is necessary to switch the identification means (not shown) or the switch of the apparatus body (not shown). Based on the information indicating that the number of colors of the ink is three and the information indicating the order in which the inks are arranged, it is possible to know the color that comes into contact with each of the heating resistors H constituting the thermal head 1. The color data of (Y) is assigned to the energized heating resistor H that contacts the area (Y) (the number of energized heating resistors H = Hy). The color data of (M) is allocated to the heating resistor H (the number of the heating resistors H is Hm), and the color data of (C) is assigned to the heating resistor H in contact with the area (C). (This energizing heating resistor Be the number = Hc body H).

Since color unevenness is likely to occur near the application boundary of each color ink, the heating resistor in the vicinity is not used (referred to as a non-energized heating resistor S). The scanning direction of the thermal head 1 (horizontal direction in the drawing) is the main scanning, and the feeding direction of the recording paper 3 (upward in the drawing) is the sub-scanning. The recording method is described below, where Hmax is 5, and the number T of the non-energized heating resistors is 3, respectively.

First, sub-scanning is performed so that the recording surface of the recording paper 3 overlaps (Y) of the ink film 2, and the first main scanning of the thermal head 1 is performed. By this main scanning, the recording by (Y) is performed on the recording paper 3 for the maximum number of the current-carrying heating resistors H, that is, five. The ink film 2 is fed by the amount used for recording after the main scanning of the thermal head 1, and the thermal head 1 returns to the initial position. Hereinafter, the conveyance of the ink film 2 and the movement of the thermal head 1 to the initial position are the same, and thus will not be described.

The width of the energized heating resistor H and the energized heating resistor H
The sum of the distances between them is referred to as the pitch P of the current-carrying heating resistors. After the recording by (Y) is completed on the recording paper 3, 5P
The recording paper 3 is sub-scanned upward by the amount corresponding to the thermal head 1.
2 is performed for the second time. By this scanning, 3 out of the five (Y) already recorded on the recording paper 3
The book comes into contact with the non-energized heating resistor S, and the recording of (M) on the ink film 2 is performed for the remaining two books. Further, five new recordings by (Y) are performed.

Subsequently, the recording paper 3 is sub-scanned upward by 5P, and a third main scan is performed. With this scan,
The recording by (M) and (Y) is performed five each.

Further, the recording paper 3 is sub-scanned upward by 5P, and a fourth main scan is performed. As a result of this scanning, three of the fifteen (Y) recorded on the recording paper 3 are formed by the energized heating resistor H in contact with (Y) and the energized heating resistor H in contact with (M). The non-energized heating resistors S located at the boundary are brought into contact with each other, and the recording of five of them is performed by (M). Then, since three contact the non-energizing heating resistors S located at the boundary between the energizing heating resistors H contacting (M) and the energizing heating resistors H contacting (C), the recording by (C) is performed. Is (1
5-3-5-3 = 4) Four lines are performed. Further, five new recordings by (Y) are performed.

In the fifth and subsequent main scans, the recording paper 3 is sub-scanned upward by 5P, and (Y),
Five recordings are performed for each of (M) and (C).

The printing ends sequentially from the first color (Y) where print data is lost, contrary to the start. A color image is formed by the above steps.

Here, the numbers Hy, Hm, and Hc of the energized heating resistors in the main scanning of the thermal head 1 from the first time to the fifth time for each color are shown below. At this time, the number of the non-energizing heating resistors S contacting the vicinity of the boundary of each color is set to T = 3, and the maximum value Hmax of the number of energizing heating resistors Hy, Hm, Hc is set to five each.

In the first to fifth main scans, the number Hy of energized heating resistors for the first color (Y) is always five.

The number Hm of the energized heating resistors for the second color (M) is 0 at the end of the first main scan, and at the end of the second main scan, it depends on the heating resistor H for (Y). The number T (three) of the non-energizing heating resistors S is subtracted from the recorded five, and the number is two. The number of energized heating resistors Hm at the end of the third to fifth main scans is five each time.

The number Hc of current-carrying resistors for the third color (C) is zero at the end of the first and second main scans. Further, at the end of the third main scan, the number of heating resistors H corresponding to (M) from (10) recorded by heating resistors H for (Y) (5)
) And the number 2T (six) of the non-energized heating resistors S are reduced to −1, so that the value is 0 as in the first and second times.
It becomes a book. Further, at the end of the fourth main scan, (Y)
The number (5) of the heating resistors H and the number 2T (six) of the non-energizing heating resistors S for (M) are reduced from fifteen recorded by the heating resistors H for (M) to four.
Further, the number Hc of energized heating resistors at the end of the fifth main scan is five.

As described above, the following equation holds when the number of heating resistors that are energized for each color is viewed. The number of scans of the thermal head is N, and the maximum number of heating resistors per color is H.
When T is the number of non-energizing heating elements near the color boundary of the ink film and Z is the number of colors of the applied ink in order, the number H of heating elements to be energized is H = {N- (Z-1)} Hmax- (Z-1) T. However, when the value of H becomes negative, it is set to 0, and H
Shall not exceed Hmax.

Even when the number of ink colors increases, the identification means determines the number of ink colors, calculates color data corresponding to each color ink, and controls the energized position of each heating resistor. It is possible to use ink cartridges of a different number of colors than those of the present embodiment.

For example, in the case where an ink film coated with four color inks in which black (K) ink is added in addition to the three color inks described above is used, the number of energized heating resistors H is set to four, and Assuming that the number of the non-energized heating resistors is one, the number of the heating resistors in contact with the ink film is 4 × 4.
+ 1 × 3 = 19. At this time, it can be dealt with by turning off the two heating resistors at the upper and lower ends or by turning off one heating resistor at the upper and lower ends. It becomes a dot.

When recording a monochrome image or text, an ink cartridge loaded with an ink film coated with black ink on one side is used, and all the heating resistors (21 in the above embodiment) are energized. However, by transporting the recording paper 3 by 21 dots, the recording time can be reduced.

[0034]

As described above in detail, according to the image recording method of the present invention, it is not necessary to reciprocate the recording paper, so that a high-quality color image with no registration deviation can be obtained, and a high-precision color image can be obtained. The need for a recording paper transport mechanism is eliminated, and costs can be reduced. In addition, since an ink film applied in a sequential manner is not used, there is no need to search for the ink color, so that control is simplified. Further, since the heating resistor to be energized can be changed according to the number of colors, ink films having different numbers of colors can be easily used. In addition, when recording monochrome images or single-color text, an ink film coated with single-color black ink is used to energize and heat all the heating elements of the thermal head to increase the conveyance width of the recording paper. The effect that it can measure is produced.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of an image recording method according to the present invention.

FIG. 2 is a diagram showing an ink cartridge used in the image recording method according to the present invention.

FIG. 3 is a diagram showing an operation according to an embodiment of an image recording method according to the present invention.

FIG. 4 is a diagram showing a conventional example of an image recording method.

FIG. 5 is a diagram showing another conventional example of an image recording method.

FIG. 6 is a diagram illustrating an ink cartridge used in a conventional example of an image recording method.

FIG. 7 is a diagram showing still another conventional example of the image recording method.

[Explanation of symbols]

 1,11,21 Thermal head 2,12 Ink film 3 Recording paper 4 Platen roller 6 Cue mark 7 Red ink 8 Blue ink 9 Yellow ink 10 Transfer part

Claims (5)

[Claims] 1. A plurality of heating resistors in which a plurality of color inks are applied in parallel with the longitudinal direction of a tape-shaped film, and a plurality of heating resistors are arranged in a line in the width direction of the ink film by the same length as the ink film. A thermal head having pressure contact with the recording paper, energizing the heating resistor with color data corresponding to the color of the ink film in contact with the heating resistor, and each time the thermal head scans the recording paper, An image recording method for recording and forming a color image by conveying a recording sheet in the width direction of the ink film, wherein a pitch at which the recording sheet is conveyed is set to an integral multiple of a pitch of the heating resistor. Method. 2. The image recording method according to claim 1, wherein no current is supplied to the heating resistor that comes into contact with the vicinity of a color boundary of the ink film. 3. The method according to claim 1, wherein the number of colors of the ink applied to the ink film is detected, and the number of the heating resistors to be energized per color and the pitch for conveying the recording paper are changed according to the detected number of colors. The image recording method according to claim 1, wherein: 4. A method for detecting the number of colors of ink applied to the ink film, the number of heating resistors to be energized, the number of heating resistors not to be energized, and the number of recording papers per color in accordance with the detected number of colors. 3. The image recording method according to claim 2, wherein a pitch at which the image is conveyed is changed. 5. The number of scans of the thermal head is N, the maximum number of heating resistors per color is Hmax, the number of heating resistors not energized near one boundary of the color of the ink film is T, and the number of applied inks is T. When the number of colors is counted in the order of scanning with the thermal head, Z is the number H of heating resistors to be energized for each color, H = ｛N− (Z−
1) Hmax- (Z-1) T (where H is a negative value is 0, and the value of H does not exceed Hmax). The image recording method described in 1.