JPH07256915A - Recording head and recorder - Google Patents

Abstract

PURPOSE:To obtain a smooth gradation without lowering a resolution and perform high-quality recording without a rough feel while keeping advantages in a prior art, such as a low cost, a small size, and a light weight. CONSTITUTION:In a thermal head provided with a plurality of heating resistors, odd-numbered heating resistors 24a,... and even-numbered heating resistors 24a,... are shifted to each other in a direction vertical to the direction of arranging the heating resistors 24a,....

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording head such as a thermal head having a plurality of heating resistors and a recording device for driving the recording head.

[0002]

2. Description of the Related Art In recent years, melt-type and sublimation-type thermal transfer recording has no noise, is low in cost, can be easily reduced in size and weight, and is excellent in operability and maintainability. Is used for. This method uses a thermal transfer ink ribbon (hereinafter referred to as an ink ribbon) in which a heat-meltable or sublimable ink layer is provided on a sheet-shaped base film, and this ink ribbon is selectively used by a thermal head or the like. By heating, the ink layer is melted and sublimated, and the ink is transferred onto a recording medium to record an image according to the heating pattern. Also, with the colorization,
There is an increasing demand for high-quality full-color image forming apparatuses. In thermal transfer recording, in order to obtain a full-color image, a method is adopted in which area modulation or density modulation is performed for each image point according to gradation data to obtain gradation.

However, there are the following problems. In order to perform area modulation or density modulation for each image point according to gradation data, area modulation can obtain image points of uniform size corresponding to gradation data, and density modulation can similarly obtain density. It is necessary. 20 and 21 show a main part and a cross section of a conventional thermal head. That is, the vicinity of the heating resistor 102 of the thermal head 101 is shown. The heating resistors 102 were arranged in one row without shifting in the sub-scanning direction (direction perpendicular to the heating element arrangement direction). Therefore, when the adjacent heating resistors 102 are simultaneously driven,
In the case of image points that must be isolated from each other, thermal interference occurs in the main scanning direction, so that ink is transferred between the image points. Therefore, it is not possible to form an accurate image point according to the gradation data, and smooth gradation cannot be obtained.

As a means for improving these, Japanese Patent Laid-Open No. Sho 64-64
In Japanese Laid-Open Patent Publication No. 80556, in order to enhance gradation, printing is performed for each heating resistor in the main scanning direction, and a heating resistor for printing for each line is provided for each pixel. A print image of this system is shown in FIG. However, the resolution of the recording by this method is reduced to 1/2, and the recorded image is rough and rough.

[0005]

SUMMARY OF THE INVENTION According to the present invention, as described above, when an attempt is made to obtain smooth gradation, the resolution is lowered and the recorded image becomes rough and rough. It eliminates the disadvantage of causing a loss of quality, and while maintaining the advantages of conventional cost reduction, size reduction, and weight reduction, smooth gradation can be obtained without lowering resolution, and high-quality recording without graininess can be achieved. An object of the present invention is to provide a recording head and a recording device that can perform the recording.

[0006]

According to the recording head of the present invention, the odd-numbered heat generating resistor rows and the even-numbered heat generating resistor rows are displaced from each other in the direction perpendicular to the arrangement direction of the heat generating resistors. There is. The recording apparatus of the present invention has a plurality of heating resistors, and the odd-numbered heating resistor rows and the even-numbered heating resistor rows in the array direction of the heating resistors are perpendicular to the heating resistor array direction. And a driving means for driving the odd-numbered heat generating resistor rows and the even-numbered heat generating resistor rows of the recording head by changing the heat generation timing according to the respective shift amounts. It consists of

The recording apparatus of the present invention has a plurality of heat generating resistors, and the odd number heat generating resistor rows and the even number heat generating resistor rows in the arrangement direction of the heat generating resistors are arranged in the heat generating resistors. A recording head configured to be displaced in the direction perpendicular to the direction by a predetermined multiple of the interval in the arrangement direction of the heat generating resistors, image data generating means for generating recording image data to be recorded on this recording head, and this image data generation Data obtained by shifting the data recorded by the even-numbered heating resistors by the predetermined multiple from the data recorded by the odd-numbered heating resistors among the image data generated by the means. And a driving means for driving the recording head based on the data converted by the converting means.

[0008]

According to the present invention, in the above-mentioned structure, the odd-numbered heating resistor rows and the even-numbered heating resistor rows are displaced in the direction perpendicular to the arrangement direction of the heating resistors.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG.
9 to FIG. 2 and 3 are views for explaining the outline of the recording apparatus according to the present invention.

That is, the platen drum 1 is arranged at the substantially central portion. The periphery of the platen drum 1 is made of an elastic material such as rubber, and has a function as a platen roller of the thermal head (recording head) 2.

The platen drum 1 is a sheet (transfer sheet, image receiving sheet, recording sheet) when it rotates clockwise.
The sheet P is wrapped around itself to prevent the sheet P from being displaced during overlay printing. Around the platen drum 1,
Pressure rollers 3, ... Are provided to prevent the paper P from floating above the platen drum 1 at predetermined intervals. The circumference of the platen drum 1 is slightly longer than the length of the maximum paper size in the longitudinal direction.

A thermal head 2 is arranged below the platen drum 1. Further, an ink ribbon 4 as a transfer medium is interposed between the platen drum 1 and the thermal head 2.

The ink ribbon 4 is wound around an ink ribbon supply reel 5 and an ink ribbon take-up reel 6 and is conveyed (moved) by drive rollers 7. The drive roller 7 is connected to a drive shaft of a pulse motor (not shown) through a drive force transmission mechanism (not shown), and is rotationally driven as necessary.

On the left side of the platen drum 1, there is provided a paper feed cassette 8 for accommodating paper P, ... As transfer paper. A paper feed roller 9 is provided above the paper feed cassette 8 so as to take out the paper P stored in the paper feed cassette 8 one by one.

The paper P is made of PP if the ink is fusible.
C paper, thermal transfer paper, or recording paper with high smoothness may be used, but synthetic paper having pores of 2 to 20 μm on the recording surface is desirable. Further, when the ink layer 4b is sublimable, it may be any recording paper provided with an image receiving layer for receiving sublimable ink on the recording surface.

The paper P taken out by the paper feed roller 9 is sent to the registration rollers 10 and 10 via the guides 11a and 11a, and the leading end of the paper P is aligned.
0 and 10 are transferred to the platen drum 1 via the guides 11b and 11b, and are wound around the platen drum 1 by the clips 12, the pressing rollers 3, ... Here, the paper feed cassette 8 is detachable from the side surface of the main body.

The paper P, the tip of which is fixed by the clip 12, is wound around the platen drum 1 by rotation in the counterclockwise direction, and after the tip passes through the recording area, the thermal head 2 is pressed against the platen drum 1. , Recording is done.

When the recording is completed and the sheet is discharged, the platen drum 1 is rotated counterclockwise until the trailing edge of the sheet P reaches the sheet discharge guide 13, and when it reaches the platen drum 1, the platen drum 1 is rotated. 1 is rotated in the clockwise direction, and the rear end of the paper P is separated from the platen drum 1 by a not-shown separation claw and guided to the paper discharge guide 13. Finally, the front end of the paper P is released from the gripper 12, and the recorded paper P conveyed by the paper discharge guide 13 is discharged onto the paper discharge tray 14.

A control circuit 15 for controlling the entire apparatus is provided below the discharge tray 14. As shown in FIGS. 1, 4, 5, and 6, the thermal head 2 has a support member 21 of aluminum as a support member, a ceramic substrate 22, a glaze layer 23, a heating resistor layer 24, an individual electrode 26, ..., the common electrode 25 and the protective layer 27 made of glass having excellent wear resistance are laminated, and the heating resistor 24 is formed.
.. are formed by sputtering and etching.

The thermal head 2 is obtained by attaching a ceramic substrate 22, a control IC (electrode control circuit) 32, ..., A drive substrate 31 on which external connection terminals 33 are mounted by adhering an aluminum support 21. Is.

The heating resistors 24a, ... And the individual electrodes 26,
628 are formed, and the width of the ceramic substrate 22 is set to 100 mm so that the column length of the heating resistors 24 a can be formed to be 78.5 mm. .. on the side opposite to the common electrode 25 are connected to the output terminal of the control IC 32 by wire bonding.

One of the control ICs 32 has 64 constant voltage drive circuits, and therefore 10 control ICs 3 are provided.
2, the heating resistors 24a, ... Are driven. The output terminal of the control IC 32 for each electrode is connected to the external connection terminal 33 by a conductive pattern wiring provided on the plane of the drive substrate 31.

As shown in FIGS. 1 and 4, the heating resistors 24a, ... Are arranged in a plurality of columns in the main scanning direction (arrangement direction of the heating resistors 24a, ...) And are adjacent in the main scanning direction. The heating resistors 24a, ... Are in the sub-scanning direction (the heating resistors 24a,
Are arranged so that they are not in the same column (direction perpendicular to the arrangement direction of ...).

Further, the heating resistors 24a, ... Have a pitch X1 in the sub-scanning direction of the heating resistor row rather than a pitch X1 in the main scanning direction.
2 are arranged so as to be equal to or larger than each other, and the length L2 of the heating resistors 24a, ... In the sub-scanning direction is formed shorter than the pitch X2 of the heating resistor rows. The heating resistor rows in FIGS. 1 and 4 are two rows (odd-numbered rows and even-numbered rows), and the pitch X2 of the heating resistor rows in the sub-scanning direction is 1 time the pitch X1 in the main scanning direction. That is the case.

In the heating resistor row, the distance between the most upstream row and the most downstream row in the paper P transport direction (sub-scanning direction) is 1.
It is desirable that the thickness is about mm or less. This is because if it is more than this value, it becomes difficult to bring all the heating resistor arrays into stable contact with the paper P at one time.

In this embodiment, the heating resistors 24a, ... Have a pitch X1 in the main scanning direction of 125 μm and a width of 100 μm.
The pitch X2 in the sub-scanning direction is P = 1 times 125 μm, the width is 100 μm, and the heating resistor rows of the even-numbered heating resistors 24a, ... Are separated from the odd-numbered heating resistors 24a ,. , Are arranged on the downstream side.

As shown in FIG. 7, the ink ribbon 4 comprises a base film 4a of polyethylene terephthalate having a thickness of 4.5 μm and a dye and a heat-meltable binder of 3 μm.
This is a configuration in which a thick ink layer 4b is provided.

The base film 4a has a thickness of 3.5 .mu.m.
It is preferable that the ink layer 4b has a thickness of about 6 μm and a thickness of about 1 μm to 4 μm. This is because if the base film 4a is too thin, the handling will be poor, and if it is too thick, the recording sensitivity will decrease. This is because if the ink layer 4b is thin, the density will decrease, and if it is thick, the transfer of ink will deteriorate and the image will deteriorate.

In this embodiment, an intermediate value is used. In the ink layer 4b, the yellow ink layer 4Y containing a yellow dye, the magenta ink layer 4M containing a magenta dye, and the cyan ink layer 4C containing a cyan dye are sequentially arranged in the flow direction of the ink ribbon 4 (opposite the transport direction). The length of the ink layer 4b of one color that has been applied corresponds to the length of the recording screen, and is 145 mm in this embodiment. The width of each dye of the ink layer 4b is set to 84 mm so as to sufficiently cover the row length of the heating resistors 24a, ....

Further, as the ink layer 4b, a sublimable ink composed of a sublimable dye and a binder may be used. The thickness of the ink layer 4b is preferably about 1 μm to 4 μm as described above. Next, the control circuit 15 will be described with reference to FIG.

That is, a CPU 41 is provided as a control unit for controlling the entire recording apparatus. This CPU41
The ROM 42, the RAM 43, the drivers 44, 45, 46, 47, the color division processing unit 48, the heat generation data generation unit 55, and the interfaces 49, 50 are connected to the via a bus 51. A control program is stored in the ROM 42. The RAM 43 is used for storing image data to be recorded and used for working, and has counting units 43a and 43b for counting the number of pulses of the conveyance state of each pulse motor.

The driver 44 drives the thermal head 2, and the driver 45 drives the solenoid 52 for transmitting the rotational force of the pulse motor 53 to the sheet feeding roller 9,
The platen drum 1 that conveys the paper P and the ink ribbon 4 by the driver 46, the drive roller pair 7, and the registration roller 1
A pulse motor 53 that rotates 0, 10 and the like is driven, and a driver 47 drives a pulse motor 54 that drives a mechanism (not shown) that moves the thermal head 2 (or the platen drum 1) up and down.

An external personal computer (personal computer) 56 is selectively connected to the interface 49,
The recording code from the external personal computer 56 is accepted. A scanner 57 is selectively connected to the interface 50 to receive image data from the scanner 57.

The color division processing section 48 uses the interface 4
R (red), G (green), which was captured at 9, 50,
The image data of B (blue) is converted for each of yellow, magenta, and cyan.

The heat generation data generating section 55 is for generating heat generation data from the image data, and the heat generation data is supplied to the driver 44. This heat generation data generation unit 55
Is composed of, for example, a RAM or a circuit shown in FIG. 16 described later.

The driver 44 generates heat data from the heat data generator 55, a latch signal LAT, and a clock signal CL.
K is for controlling the thermal head 2 based on the enable signal ENL and the like, and has a buffer 44a for storing and holding heat generation data from the heat generation data generation unit 55.

Next, the operation of the recording apparatus using the thermal head 2 of the present invention will be described with reference to FIG. First, the paper P is taken out from the cassette 13, wound around the platen drum 1, and the tip of the paper P is fixed and held by the platen drum 1 by the clip 12. The ink ribbon 4 is pulled out from the ink ribbon supply reel 5 by the drive roller pair 7 that conveys the ink ribbon 4, and the yellow ink layer 4Y is first cued.

During this series of operation of the paper P and the ink ribbon 4, the thermal head 2 is separated from the platen drum 1, but after the ink ribbon 4 and the paper P are set to the fixed positions, the thermal head 2 is moved. Is urged by the platen drum 1.

Then, the recording signal of the yellow component is controlled by the control I of the thermal head 2 from the color image signal (not shown).
, And the recording current is selectively supplied to the individual electrodes 26, ....

The paper P is sent in accordance with the rotation of the platen drum 1, and the recording of the yellow screen is completed. Next, the thermal head 2 is separated from the platen drum 1, and the paper P
Recording screen and magenta ink layer 4 of ink ribbon 4
Then, the thermal head 2 is energized again to the platen drum 1, a recording current is supplied according to the recording signal of the magenta component of the recording electrode 6, and the magenta image is recorded by superimposing it on the yellow image. Is done.

Then, a cyan image is recorded by the same operation. After the recording of the cyan image, the thermal head 2 is separated from the platen drum 1 and the conveyance of the ink ribbon 4 is stopped, but the paper P is sent out according to the rotation of the platen drum 1, and the paper discharge guides 13 and 13 are used. The clip 12 is removed, the leading edge of the paper P is released, and the paper P is discharged onto the paper discharge tray 14.

Next, the recording start and recording operation in the above configuration will be described. First, image data supplied from an external device such as the external personal computer 56 and the scanner 57 is input via the interfaces 49 and 50 and stored in the RAM 43. After that, for the R, G, and B image data input by the color conversion processing unit 48, Y (yellow),
Each heating resistor 24 for each of M (magenta) and C (cyan)
are converted into image data corresponding to a, .... Further, it is necessary to convert the Y, M, and C image data to correct the pitch X2 of the heating resistors 24a, ... In the sub-scanning direction so that a correct image can be obtained. The conversion means will be described.

First, an example in which the pitch X2 in the sub-scanning direction is a positive integer multiple of the pitch X1 in the main scanning direction will be shown. The arrangement of the heating resistors 24a, ... Of the thermal head 2 is the case of X1 = X2 in FIG.

In order to print the image data of the same line so as to form a straight line in the sub-scanning direction on the image, considering the columns of the odd-numbered heating resistors 24a, ... As a reference, the even-numbered heating resistors 24a are used. The rows of, ... Are on the front side in the sub-scanning direction, so it is necessary to print with a delay of one pitch. Since one pitch X2 is just one pixel here, the image data corresponding to the even-numbered heat generating resistors 24a, ... May be shifted backward by one line on the heat generating data generating unit 55 configured by the RAM. 9 shows the original image data, and FIG. 10 shows the converted image data. FIG. 11 shows a flowchart for performing this processing.

The odd-numbered heating resistors 24a in the first line, ...
, And the image data corresponding to the even-numbered heating resistors 24a, ... Are set to '0'. In the second line, the image data corresponding to the even-numbered heating resistors 24a, ...
The image data corresponding to a, ... Is left unchanged. This 2
The image data of the first row is obtained by taking the logical sum of the image data to the heating resistors 24a, ... Of the columns. If this process is performed up to the last line, converted image data (heat generation data) can be obtained.

Since there is no next line in the last line,
The calculation is performed using a column in which all the image data is "0". Similarly, the pitch X2 in the sub scanning direction is the pitch X in the main scanning direction.
In case of the integer multiples such as 1, 2, 3, ..., The number of rows of the image data corresponding to the even-numbered heating resistors 24a ,.

Next, when the pitch X2 in the sub-scanning direction is not an integral multiple of the pitch X1 in the main scanning direction, an example of 1.5 times is shown. The heating resistor 24a of the thermal head 2, ...
The arrangement is for the case of X2 = 1.5 * X1 with respect to FIG.

Since X2 is 1.5 pixels, 1 of them
As shown in FIGS. 9 and 10, the pixel portion is corrected using the flowchart of FIG. A method of correcting the remaining 0.5 pixels will be described. 12A to 12F show a signal HSYNC which determines one sub-scanning line cycle of this recording apparatus.
And a timing chart of signals transferred to the thermal head 2. One sub-scanning line cycle is a time for forming one dot, and the DATA signal can be rewritten up to 20 times during that period. That is, dots having densities in 21 levels from 0 to 20 can be obtained, but in order to prevent the heat generating resistors 24a, ... I am trying. When the period in which DATA (image data) can be rewritten is the sub-line period, this is the time obtained by dividing the sub-scanning line period into 20.

Here, considering the dot formation in a certain row,
The image data corresponding to the odd-numbered heat generating resistors 24a, ... Are transferred by forming the dots from the first to fifteenth DATA of DATA within one scanning line cycle. The image data corresponding to the even-numbered heat generating resistors 24a, ... Is transferred from No. 11 of DATA in one scanning cycle, and if transferred to No. 5 of DATA in the next one sub-scanning line cycle, odd-numbered heat generation is performed. The dots corresponding to the even-numbered heat generating resistors 24a, ... Are displaced by 0.5 pixel in time with respect to the dots corresponding to the resistors 24a ,. line up.

If the pitch X2 of the heating resistors 24a, ... In the sub-scanning direction is 1.4 times the pitch X1 in the main scanning direction, the image data corresponding to the even-numbered heating resistors 24a ,. You can transfer it from No. 8 of
It can be adjusted at the position of DATA at which the transfer of image data is started.

13A to 13C show image data of a certain column corresponding to the even-numbered heat generating resistors 24a, .... Although FIG. 13A shows 16-valued image data of the n-1, n, and n + 1 lines, it is actually necessary to shift the image backward by 0.5 pixel as shown in FIG. 13B. There is. In the sub-line, multi-value density information of 1 pixel is printed.
It is expanded to '0' which is not printed. For example, in the nth sub-scanning line A of FIG. 13C, sub-lines 1 to 20 are determined as shown in the figure.

14A and 14B show image data of the nth row of a certain column corresponding to the odd-numbered heating resistors 24a, .... 14A shows 16-valued image data, which is shown in FIG.
4 (b) is developed into sub-lines.

That is, if (1) the heating resistors 24a, ... Are odd-numbered or even-numbered, or (2) even-numbered, the image data of the previous row of the same column and the image data of that row are odd-numbered. If there is, the print pattern is determined by the image data of that row and (3) the number of sub-lines, and this pattern is called heat generation data.

FIG. 15 shows the address of the memory (memory 67 of FIG. 16 described later) in which this heating data is stored and its meaning. The upper 2 bits are the heating resistor 24.
a, ..., Odd number, even number, the next 4 bits are the image data of the previous row, the next 4 bits are the image data of the row, and the next 6 bits are the number of sub-lines. This is an example of sub-line 1 of sub-scan line A. Data "1" is stored for this address.

FIG. 16 is a block diagram of the heat generation data generator 55. The image data supplied from the RAM 43 and the image data from the line buffer 61 one row before this image data are written into and read from the buffers a63 and 64. However, when writing to one side, the writing control circuit 62 and the reading control circuit 65 are controlled so that the other side is read.

Depending on the image data read from the buffer 63 or the buffer 64 and the image data of the previous row, the number of sub-lines generated from the sub-line counter 66, the even number or the odd number of the heating resistors 24a ,. Predetermined heat generation data is output from the memory 67 according to the designated address. Such processing is performed on the image data of the first row to the image data of the last row of a certain row, here the image data up to the 628th column because the number of heating resistors 24a, ... , Are stored in the buffer 44a in the driver 44. Buffer 44
Two a are also prepared like buffers 63 and 64,
It is used as a buffer for writing the heat data of a certain row and a buffer for reading to the thermal head 2.

The heat data of each row written in the buffer 44a is then converted into DATA for each sub-line, as shown in the timing charts (a) to (f) of FIG. 12, as shown in the timing chart of FIG. It is transferred to the thermal head 2 together with the enable signal ENL.
The paper P and the ink ribbon are conveyed by the rotation of the pulse motor 53 in synchronization with the heat generation operation of the thermal head 1.
An image of the row is formed. An image of one color can be formed by performing this operation up to the last line, and further, a single screen of a color image can be recorded by repeating the fractions of yellow, magenta, and cyan.

DATA in sub-line units for the respective heating resistors 24a, ... Is as shown in FIG. 17, for example. FIG. 18 shows a conventional thermal head 101,
The temperature distribution and the shape of the image points on the heating resistors 24a, ..., 102, ... When recorded by the thermal head 2 of the present invention, FIG.
9 shows a graph of gradation characteristics of reflection density. The recording conditions are as follows: Heat generating resistors 24 of Nos. 1, 2 and 3
, 102, ... are used to form a total of six image points with two image points each. The temperature distribution and the image points change depending on the number of energizing pulses (P1, P2, P3, P4) by the enable signal ENL according to the gradation data.

Further, regarding the temperature distribution, the heating resistors Nos. 1 and 2 of the conventional thermal head 101 driven simultaneously, and the heating resistors No. 1 of the thermal head 2 of the present invention driven simultaneously were used.
, 102, and so on on the line passing through the centers of the heating resistors 24a, ..., 102 ,.

As shown in FIG. 18, in the case of the conventional thermal head 101, since the heating resistors 102, ... Are adjacently arranged in one row, the influence of thermal interference is large, and particularly the intermediate image points. The influence appears at the time of formation. The temperature between the adjacent image points (hereinafter referred to as "between adjacent image points") that are driven at the same time is the number of pulses of (2) near the ink melting temperature t when the image points are formed.
With the number of pulses, the temperature exceeds the melting temperature t of the ink when forming the image point.

Therefore, in (2), the ink is transferred between bridged image points by bridging, or is not transferred or becomes unstable, resulting in a distorted image point shape.
Predetermined image points cannot be formed. In the case of (3), the ink is completely bridged and transferred between the adjacent image points, and the intermediate image point is formed into an image point larger than a predetermined image point shape. For this reason, the conventional thermal head 101 cannot be formed to have a predetermined size of an image point, and the gradation characteristic becomes a binary characteristic as shown in FIG.

In the thermal head 2 of the present invention, as shown in FIG.
As shown in FIG. 5, the column of the heating resistors 24a, ... Arranged in the main scanning direction is arranged in the main scanning direction so that the adjacent heating resistors 24a ,. Since they are arranged so as to be displaced from each other in the sub-scanning direction so that the pitch X2 in the sub-scanning direction is larger than the pitch X1 in the sub-scanning direction, the influence of thermal interference is small, and the influence of thermal interference does not affect the formation of image points.

With the pulse numbers of (2) and (3) in FIG. 18, the ink melting temperature t does not exceed the ink melting temperature t due to thermal interference between adjacent image points even when the image points are formed. It does not bridge and transfer. Therefore, compared with the conventional thermal head, it is possible to form a predetermined image point according to the gradation data (application time). As for gradation characteristics, as shown in FIG. 19, a smooth gradation can be obtained in the medium density range as compared with the conventional case.

Further, in the apparatus of the present invention, since each of the heating resistors 24a, ... Forming an image point in accordance with the gradation data, the recording determined by the pitch of the heating resistors 24a ,. The resolution can be maintained, and a recorded image with no roughness can be obtained.

As described above, in the thermal head having a plurality of heating resistors, since the heating resistors are arranged in a plurality of rows in the main scanning direction, the thermal interference due to the influence of the adjacent heating resistors when forming the image points. Stable image formation can be performed without being affected by. Therefore, smooth gradation can be obtained,
High quality recording is possible.

Further, since the adjacent heating resistors are not in the same row, the distance between the heating resistors is increased, the thermal interference from the adjacent heating resistors is eliminated, and a smoother gradation can be obtained in the medium density range. be able to.

Further, when the length of the heating resistors in the sub-scanning direction is L2 and the pitch of the rows of the heating resistors in the sub-scanning direction is X2, if L2 ≦ X2, the adjacent heating resistors are sub-scanned. Since there is no overlap in the direction, thermal interference is eliminated, and a smoother gradation can be obtained in the medium density range.

Further, an ink ribbon having an ink layer for thermal transfer and a base film, and a thermal head having a heating resistor for heating the ink ribbon from the base film side are used and each pixel is adjusted in accordance with the image density. In the copying and recording in which the recording energy is changed to perform the gradation recording, the heating resistors of the thermal head are arranged in a plurality of rows in the main scanning direction, and when the rows of the heating resistors have a pitch X2 in the sub scanning direction,
Since there is a means for correcting the heat generation timing of the row of heating resistors which is displaced from the reference row of heating resistors by the pitch X2 in the sub-scanning direction, the pitch X2 of the rows of heating resistors in the sub-scanning direction is provided. Even if is not an integral multiple of the pitch X1 of the heating resistors in the main scanning direction, the heating timing of the heating resistors in the row of heating resistors is shifted according to the shift amount (X2) with respect to the reference heating resistor row. By shifting, dots can be formed at correct positions and a good image can be obtained. Further, since this correction is possible, it is not necessary to accurately set the pitch X2 of the heating resistor array in the sub-scanning direction to an integer multiple of the pitch X1 of the heating resistors in the main scanning direction. To do.

Further, the heating resistor arrays are simultaneously driven for recording, but the pitch in the sub-scanning direction is exactly P (P is an integer of 1 or more) times the pitch in the main scanning direction. When the image point formed by the heating resistor on the side is conveyed and reaches the same position as the next heating resistor row, this is driven to record the image point. Therefore, the position of the image point does not deviate. Therefore, by making the pitch in the sub-scanning direction P times the pitch in the main-scanning direction (P is an integer of 1 or more), image points that are continuous in the main-scanning direction, that is, straight lines and characters are compared to the case where it is not. In, you can make clear recording without any deviation.

[0070]

As described above in detail, according to the present invention,
It is possible to provide a recording head and a recording device capable of performing high-quality recording without rough feeling, while maintaining the advantages of conventional cost reduction, size reduction, and weight reduction, while achieving smooth gradation without lowering resolution. .

[Brief description of drawings]

FIG. 1 is a perspective view showing the configuration of a thermal head in a recording apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a schematic configuration of a recording device.

FIG. 3 is a diagram for explaining a schematic configuration of a recording device.

FIG. 4 is a plan view showing a configuration near a heating resistor of a thermal head.

FIG. 5 is a cross-sectional view showing a configuration near a heating resistor of a thermal head.

FIG. 6 is a cross-sectional view showing a configuration near a heating resistor of a thermal head.

FIG. 7 is a diagram showing a configuration example of an ink ribbon.

FIG. 8 is a block diagram showing a configuration of a control circuit of the recording apparatus.

FIG. 9 is a diagram for explaining original image data before conversion in a heat generation data generation unit.

FIG. 10 is a diagram for explaining image data after conversion in a heat generation data generation unit.

FIG. 11 is a flowchart for explaining a conversion process of image data in a heat generation data generation unit.

FIG. 12 is a timing chart showing the timing of signals to the thermal head during one scanning line.

FIG. 13 is a column n corresponding to an even-numbered heating resistor.
The figure for demonstrating the image data of a line.

FIG. 14 is a column of n corresponding to odd-numbered heating resistors.
The figure for demonstrating the image data of a line.

FIG. 15 is a diagram showing addresses of a memory in which a table for converting image data into heat generation data is stored and its meaning.

FIG. 16 is a block diagram of a heat generation data generation unit.

FIG. 17: DA in sub-line units for each heating resistor
The figure for demonstrating TA.

FIG. 18 is a diagram showing dot shapes for respective recording energies in the thermal head of the related art and the present invention.

FIG. 19 is a diagram showing gradation characteristics in the conventional and the thermal heads of the present invention.

FIG. 20 is a plan view showing a configuration near a heating resistor of a conventional thermal head.

FIG. 21 is a cross-sectional view showing a configuration near a heating resistor of a conventional thermal head.

FIG. 22 is a diagram showing an image in which gradation characteristics are improved by using a conventional thermal head.

[Explanation of symbols]

 2 ... Thermal head 24a, ... Heating resistor

Claims (4)

[Claims] 1. A recording head having a plurality of heating resistors, wherein odd-numbered heating-resistor rows and even-numbered heating-resistor rows are arranged so as to be displaced in a direction perpendicular to the arrangement direction of the heating resistors. A recording head characterized by being 2. A plurality of heating resistors are provided, and an odd-numbered heating resistor array and an even-numbered heating resistor array in the array direction of the heating resistors are in a direction perpendicular to the array direction of the heating resistors. And a driving means for driving the odd-numbered heat generating resistor rows and the even-numbered heat generating resistor rows of the recording head by changing the heat generation timing according to the respective shift amounts. A recording device characterized by being provided. 3. A plurality of heating resistors are provided, and an odd-numbered heating resistor array and an even-numbered heating resistor array in the array direction of the heating resistors are in a direction perpendicular to the array direction of the heating resistors. A recording head that is displaced by a predetermined multiple of the interval of the heating resistors in the arrangement direction, image data generating means for generating recording image data to be recorded on this recording head, and generation by this image data generating means. A conversion for converting the data recorded by the odd-numbered heat generating resistors from the data recorded by the odd-numbered heat generating resistors into the data that is shifted by the predetermined multiple A recording apparatus comprising: a recording medium, and a driving unit that drives the recording head based on the data converted by the converting unit. 4. The first conversion means for converting the data recorded by the even-numbered heating resistors by an integer multiple of the data recorded by the odd-numbered heating resistors. A second data conversion means for shifting the data recorded by the even-numbered heating resistors with the data recorded by the odd-numbered heating resistors by a non-integer multiple. Item 5. The recording device according to item 3.