JPH06143630A - Thermal color printer - Google Patents

Abstract

PURPOSE:To reduce the capacity of power supply while shortening the recording time by optically fixing first and second thermal coloring layers thermally recorded through first and second thermal heads respectively and then thermally recording a third thermal coloring layer through the first and/or second thermal head. CONSTITUTION:The thermal color printer is constituted to thermally record each of first to third thermal, coloring layers of different colors in a thermal color recording material 11 by means of thermal heads 21, 23. The thermal color printer comprises the first and second thermal heads 21, 23 spaced apart from each other and first and second optical fixing lamps 22, 24 disposed, respectively, in the downstream of the thermal heads 21, 23. The first thermal coloring layer is thermally recorded through the first thermal head 21 and then optically fixed by mean of the first fixing lamp 22 whereas the second thermal coloring layer is thermally recorded through the second thermal head 23 and then optically fixed by means of the second optical fixing lamp 24. The third thermal coloring layer is then thermally recorded through the first and/or the second thermal head 21, 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color thermal printer using a color thermal recording material which develops color by heat energy.

[0002]

As a color thermosensitive recording material, as described in, for example, JP-A-3-288688, a cyan thermosensitive coloring layer, a magenta thermosensitive coloring layer, and a yellow thermosensitive coloring layer are sequentially formed on a support. Things are known. In this color thermosensitive recording material, the lower thermosensitive coloring layer has lower thermal recording sensitivity, and each thermosensitive coloring layer has a property of being photo-fixed by a specific electromagnetic ray.

In the case of thermally recording a multicolor image on the color thermosensitive recording material, a thermal head having a plurality of heating elements arranged in a line is used, and the color thermosensitive recording material and the thermal head are moved relatively to each other. First, the uppermost yellow thermosensitive coloring layer (third layer) is thermally recorded with a thermal head. After the thermal recording of the yellow image, light in the wavelength range in which only the uncolored diazonium salt compound in the yellow thermosensitive coloring layer is photolyzed is irradiated to photofix the yellow thermosensitive coloring layer. Next, the magenta thermosensitive coloring layer (second layer) is subjected to thermal recording by using heat energy higher than that of the yellow thermosensitive coloring layer, and then only the uncolored diazonium salt compound of the magenta thermosensitive coloring layer is recorded. The light is fixed by irradiating it with light in the wavelength range where it is photolyzed. After that, the cyan thermosensitive coloring layer (first layer) is thermally recorded using the largest thermal energy.

[0004]

In the color thermal recording method, one thermal head is used to thermally record each layer by passing the recording paper three times (three-pass method), and three thermal heads. There is a method (1 pass method) in which the recording paper is passed through using the above method and each layer is subjected to sequential thermal recording in one pass. The 3-pass method requires only one thermal head, which simplifies the configuration, but requires the recording paper to pass through three times.
There is a problem that the recording time becomes long. Further, in the 1-pass method, color recording can be performed by one pass and the recording time can be shortened, but since three thermal heads perform recording at substantially the same time, the instantaneous power becomes large. Therefore, it is necessary to increase the power supply capacity, and there is a problem that the manufacturing cost increases correspondingly.

The present invention is intended to solve the above problems, and it is an object of the present invention to provide a color thermal printer capable of reducing the instantaneous maximum power and further shortening the recording time as compared with the 3-pass system. To aim.

[0006]

In order to achieve the above object, the color thermal printer of the present invention is provided with a first separated color printer.
And a second thermal head, and first and second optical fixing devices provided on the downstream side of each thermal head. The first thermosensitive coloring layer is thermally recorded by the first thermal head, and then the first thermal coloring layer is recorded.
The second thermosensitive coloring layer is thermally fixed by the second thermal head, and then the second thermosensitive coloring layer is photofixed, and the third thermosensitive coloring layer is the first and / or the third thermosensitive coloring layer. The thermal recording is performed by the second thermal head.

[0007]

EXAMPLE In FIG. 2, a platen drum 10 holds a color thermosensitive recording material 11 on its outer periphery and is rotated by a pulse motor 9 during thermal recording and optical fixing. The color heat-sensitive recording material 11 is fixed by pressing the tip portion 11a of the color heat-sensitive recording material 11 against the peripheral surface of the platen drum 10 by the clamp member 13.

Mounting arms 15 are provided at both ends of the clamp member 13. The mounting arm 15 has a long hole 15
a is formed, and the attachment arm 15 is attached to the shaft 16 of the platen drum 10 through the elongated hole 15a. Further, the mounting arm 15 is provided with a spring 17 and a solenoid 18. The spring 17
The clamp member 13 is urged in a direction of pressing it against the peripheral surface of the platen drum 10. Further, the solenoid 18 is driven when the color thermosensitive recording material 11 is clamped and released, whereby the clamp member 13 is moved in a direction away from the peripheral surface of the platen drum 10.

On the outer periphery of the platen drum 10, a first thermal head 21 is located at the thermal recording position of the color thermal recording material 11, a yellow fixing lamp 22 is located downstream thereof, and a second thermal head 23 is located downstream thereof. The magenta fixing lamp 24 is sequentially arranged on the downstream side. The first and second thermal heads 21 and 23 are of a vertical type, and a heating element array 25 is provided at the lower ends of the thermal heads 21 and 23. The heating element array 25 is formed long in the direction orthogonal to the recording material 10 conveyance direction, and as shown in FIG. 4, a plurality of heating elements 46a and 46a.
b, ... Are arranged in a line.

The magenta fixing lamp 22 is composed of a rod-shaped ultraviolet lamp having an emission peak of about 365 nm. The yellow fixing lamp 25 has an emission peak of about 42.
It is composed of a 0 nm ultraviolet lamp.

As shown in FIG.
A pair of conveying rollers 27 is arranged, through which the color thermosensitive recording material 11 is conveyed. Also, the paper feed / discharge path 2
A separation claw 28 for guiding the rear end of the color thermosensitive recording material 11 to the sheet feeding / discharging passage 26 at the time of discharging the sheet is formed on the platen drum 10 side of No. 6. In this embodiment, one passage is used as both the paper feed passage and the paper discharge passage, but they may be provided separately.

FIG. 3 shows an example of the color thermosensitive recording material 11. The cyan thermosensitive coloring layer 3 is provided on the support 30.
1, magenta thermosensitive coloring layer 32, yellow thermosensitive coloring layer 3
3 and the protective layer 34 are sequentially provided in layers. These thermosensitive coloring layers 31 to 33 are layered from the surface in the order of thermal recording. For example, in the case of thermal recording in the order of magenta, yellow, and cyan, the yellow thermosensitive coloring layer and the magenta thermosensitive coloring layer. And are interchanged. These thermosensitive coloring layers 31 to 33 have higher coloring thermal energy as they are deeper, so that the thermosensitive coloring layers 31 to 33 of three colors can be selectively recorded by changing the coloring thermal energy.

Since the cyan thermosensitive coloring layer 31 is a deep layer and has the lowest thermal recording sensitivity, it is necessary to give a large amount of thermal energy. On the other hand, the magenta thermosensitive coloring layer 32, and further the yellow thermosensitive coloring layer 33 need only a small amount of heat energy close to the surface. Therefore, in the present invention, as shown in FIG.
For the yellow thermosensitive coloring layer 33 having the highest heat recording sensitivity and the magenta thermosensitive coloring layer 32 having the next highest sensitivity, the first and second
Thermal recording is performed by the thermal heads 21 and 23. After the thermal recording of yellow and magenta is completed, the platen drum 10 is further rotated once to perform thermal recording on the cyan thermosensitive coloring layer 31 by the second thermal head 23. Generally, the average printing power per line is Py <P
m <Pc, and the ratio is Py: Pm: Pc = 1:
It is 1.5: 2.25 (2-2.5). When this is subjected to thermal recording by the 1-pass 3-head method, the instantaneous maximum power is 4.5 to 5 in total. On the other hand, in the present embodiment, since recording of yellow and magenta and recording of cyan are separately performed by dividing into two times, the instantaneous maximum power is almost equal each time (2.5≈2.25). As a result, the instantaneous maximum power can be halved as compared with the case of the 1-pass 3-head system.

FIG. 4 shows an electric circuit of the color thermal printer. The image data input unit 40 is composed of a color scanner, a color TV camera, etc.
The image data of the three colors of blue are sent to the data processing unit 41. The data processing unit 41 performs color correction, gradation correction, etc. on the image data of each color. The image-processed image data of each color is sent to the frame memory 42 and is stored in a separated state for each color. During thermal recording, the frame memory 42
From, the image data of the color to be printed is read line by line and written in the line memory 43.

The image data for one line read from the line memory 43 is sent to the drive data generator 44 and converted into drive data for each pixel. This drive data is composed of bias drive data for generating bias heat energy and gradation drive data for generating gradation expression heat energy. The drive data for one line is sent to the head drive unit 45 and converted into a bias pulse for each pixel and a number of gradation pulses corresponding to the gradation level, and each heating element 46a of the heating element array 20. ~ 46
n. These heating elements 46a to 46n are
They are arranged in a line in the main scanning direction and move relative to the color thermosensitive recording material 11 in the sub scanning direction. In addition to the sequence control of each unit, the controller 47 controls the pulse motor 9 via the driver 48 to rotate the platen drum 10 and the conveying roller pair 27 to feed the thermosensitive recording material at a constant speed.

FIG. 5 shows an example of the head drive section 45. Serial drive data for one line is sent to the shift register 50 by a clock signal and converted into a parallel signal. The drive data converted into the parallel signal by the shift register 50 is latched in the latch circuit 51 by the latch signal. The AND gate 52 outputs the signal of "H" when the latched signal is "H" when the strobe signal is input. This AND
Each of the output terminals of the gate 52 has transistors 53a-5
3n are connected to each other, and when the output terminal of the AND gate 52 is "H", the corresponding transistor 53a
~ 53n turns on. These transistors 53a-5
3n is connected to the voltage control circuit 54 via the heating elements 46a to 46n.

The drive data for one line is created as follows. First, for bias heating, drive data of "H" is given to all pixels for one line to obtain serial drive data. When this drive data is "H", the corresponding heating element generates heat. Next, the data indicating the first gradation is compared with the image data, and it is determined whether or not the pixel is driven. If the pixel is driven, it is set to "H", and if it is not driven, it is set to "L". This comparison is performed for all the pixels in one line, and the image data is converted into serial drive data. The heating elements 46a to 46n are selectively driven by the serial drive data.
Similarly, the data indicating the second gradation is compared with the image data of each pixel, and the drive data is converted as described above.
For example, in the case of 64 gradations, including bias heating,
The drive data for one line is read out 65 times,
By the 65th strobe signal, each heating element 46a-
46n is selectively driven to display an image of 64 gradations.

Next, the operation of this embodiment will be described. At the time of thermal recording, the image data of each color input from the image data input unit 40 is subjected to image processing by the image processing unit 41 and then written in the frame memory 42 in a separated state for each color. The heat-sensitive recording material 11 is rotated by the pair of conveying rollers 27 and the platen drum 10 so that the thermal heads 21,
Sent to 23.

When the platen drum 10 rotates intermittently by a constant step and the leading end of the recording area of the color thermosensitive recording material 11 reaches the first thermal head 21, thermal recording of a yellow image is started. The image data of the yellow image is read from the frame memory 42 for one line and is once written in the line memory 43. Next, the line memory 43
Image data is read from the drive data generator 4
Send to 4. The head drive unit 45 drives each of the heating elements 46a to 46n based on the drive data, and supplies the bias heat energy and the gradation expression heat energy corresponding to the image data to the color thermosensitive recording material 11 to obtain a desired density. Color it. When the first line of the yellow image is recorded, the platen drum 10 is step-rotated by one pixel by the pulse motor 9, and at the same time, the image data of the second line of the yellow image is read from the frame memory 42. Thereafter, in the same manner, the second and subsequent lines of the yellow image are thermally recorded on the color thermosensitive recording material 11. When the portion on which the yellow image is thermally recorded reaches the optical fixing lamp 22, the yellow thermosensitive coloring layer 33 is optically fixed here.

Next, the second thermal head 23 similarly records a magenta image line by line. In the thermal recording of the magenta image, the printing power is set to about 1.5 times the printing power in the yellow thermal recording. This magenta image is also optically fixed by the optical fixing lamp 26. At the time of recording the magenta image, the first thermal head 21 simultaneously performs thermal recording of the yellow image, and the total instantaneous maximum power is the sum of these, which is about 2.5 times that at the time of recording the yellow image. .

When the platen drum 10 makes one rotation to complete the thermal recording of the yellow and magenta images, the platen drum 10 further rotates and the second thermal head 23 thermally records the cyan image line by line. In the thermal recording of this cyan image, the instantaneous maximum power is set to about 2.25 times that in the yellow thermal recording. This is because the cyan thermosensitive coloring layer has a considerably high thermal energy required for thermosensitive coloring. Therefore, since no color is developed in a normal storage state, optical fixing is omitted for this cyan thermosensitive coloring layer. Thus, in color thermal recording, as shown in FIG. 1, cyan thermal recording with large instantaneous maximum power is performed separately from other yellow and magenta thermal recording, so that the instantaneous maximum power is almost half that of the 1-pass 3-head method. It can be kept low.

When the thermal recording of each layer is completed by each thermal head, the platen drum 10 and the conveying roller pair 27 are reversed. By the reverse rotation of the platen drum 10, the rear end of the color thermosensitive recording material 11 is guided to the paper feeding / discharging path 26 by the separating claw 28 and is nipped by the conveying roller pair 27.
Thereafter, the solenoid 18 is energized and the platen drum 10 is stopped. Since the solenoid 18 moves the clamp member 13 against the spring 17, the clamp of the tip portion 11a of the color thermosensitive recording material 11 is released. After releasing the clamp, pair of transport rollers 2
The rotation of 7 restarts the discharge of the color thermosensitive recording material 11. As a result, the thermally recorded color thermosensitive recording material 1
1 is discharged to a tray (not shown) through the paper supply / discharge path 26.

In the above embodiment, the cyan thermal recording is performed once by the second thermal head, but instead of this, the first and second thermal heads are used as shown in FIG. Alternatively, the heat recording may be performed twice. In this case, since the instantaneous maximum power of each is halved, the power supply capacity can be reduced accordingly.

Although the recording material is intermittently fed in the above embodiment, it may be continuously fed. The above embodiment is a line printer in which a large number of heating elements are arranged in the main scanning direction and the color thermosensitive recording material is moved in the subscanning direction for thermal recording. However, the present invention is a thermal head and a color thermosensitive recording material. Can also be used for serial printers that perform two-dimensional relative movement to perform thermal recording. Further, in the above-described embodiment, the platen drum 10 was rotated twice to perform heat-sensitive recording, but in addition to this, the platen drum may be reversed during cyan heat-sensitive recording. Further, in the above embodiment, one platen drum 10 is used, but in addition to this, a platen roller may be provided for each thermal head.

[0025]

As described above, according to the present invention,
1st with high thermal recording sensitivity using 2 thermal heads
And the second thermosensitive coloring layer are recorded at almost the same time, and the third thermosensitive coloring layer of the lowest layer, which has low thermal recording sensitivity, is separately recorded, and the recording is performed twice. It can be halved compared to the head type. As a result, the power supply capacity can be reduced. Moreover, 3
Compared to the case of performing thermal recording by passing the recording material through the thermal head three times as in the pass 1 head system, the recording time is reduced because the recording material is passed only twice.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing heat energy supplied to each thermal head in a color thermal printer of the present invention.

FIG. 2 is a schematic view showing a main part of a color thermal printer embodying the present invention.

FIG. 3 is an explanatory diagram showing an example of a layer structure of a color thermosensitive recording material.

FIG. 4 is a block diagram showing an electrical configuration of a color thermal printer.

FIG. 5 is a circuit diagram showing a head drive unit and a heating unit.

FIG. 6 is an explanatory diagram showing heat energy supplied to each thermal head in another embodiment.

[Explanation of symbols]

 10 Platen Drum 11 Color Thermal Recording Material 21,23 Thermal Head 22,24 Optical Fixing Lamp 25 Heating Element Array 46a-46n Heating Element

Claims (1)

[Claims] 1. A color thermosensitive recording material comprising first to third thermosensitive coloring layers different in color to be developed, each thermosensitive coloring layer being provided separately in a color thermal printer for thermal recording by a thermal head. The first and second thermal heads and the first and second optical fixing devices provided on the downstream side of each thermal head are provided, and after the first thermosensitive coloring layer is thermally recorded by the first thermal head, First, the second thermosensitive coloring layer is thermally fixed by the second thermal head, and then the second thermosensitive coloring layer is thermally fixed by the second photofixing device, and the third thermosensitive coloring layer is first and / or A color thermal printer, which records heat with a second thermal head.