JPH11147323A - Color head-sensitive printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a color head-sensitive printer of a three-head, one-path type energy-saving and compact. SOLUTION: A yellow thermal head 27 and a cyan thermal head 29 are coupled by a coupling member 31 formed of a material having good heat conductivity. A remaining heat generated at a thermal recording time with the cyan thermal head 29 of a highest heat generation temperature range is transmitted via the coupling member to the yellow thermal head 27 of a low heat generation temperature range, thereby raising the yellow thermal head 27 in temperature by the remaining heat. A heat generation energy of the yellow thermal head 27 can be reduced by the remaining of heat, so that power consumption is saved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-head one-pass color thermal printer using color thermal recording paper.

[0002]

2. Description of the Related Art A color thermal printer uses a color thermosensitive recording paper having a cyan thermosensitive coloring layer, a magenta thermosensitive coloring layer, and a yellow thermosensitive coloring layer sequentially formed on a support, and directly records a full-color image. I do. When performing the color recording, a thermal head in which a plurality of heating elements are arranged in a line is used, and while the color thermal recording paper and the thermal head are relatively moved, first, the yellow thermal sensitive layer on the uppermost layer is moved by the thermal head. The coloring layer is color-recorded with low heat energy. After the color recording of the yellow thermosensitive coloring layer, the yellow thermosensitive coloring layer is light-fixed by irradiating ultraviolet rays in a wavelength range that photodecomposes only the uncolored diazonium salt compound of the yellow thermosensitive coloring layer.

[0003] Next, the color of the magenta thermosensitive coloring layer is recorded using a higher thermal energy than the color recording of the yellow thermosensitive coloring layer, and then the wavelength at which only the uncolored diazonium salt compound of the magenta thermosensitive coloring layer is photodecomposed. The magenta thermosensitive coloring layer is light-fixed by irradiating ultraviolet rays in the region. Finally, the cyan thermosensitive coloring layer is color-recorded using the largest thermal energy.

A recording method of a color thermal printer is as follows.
There are a one-head three-pass system and a three-head one-pass system. 1
The head three-pass system uses one thermal head and passes color thermal recording paper through the thermal head three times to perform color recording. The three-head, one-pass system uses three thermal heads having different temperature ranges to generate heat and sends a color thermosensitive recording paper once in one direction to record a full-color image in color, and requires three thermal heads. However, there is an advantage that a plurality of images can be continuously printed at a high speed.

[0005]

However, the color thermal printer of the three-head one-pass system uses a large amount of power because three thermal heads are simultaneously driven when a plurality of images are continuously printed. For this reason, there is a problem that the size of the built-in power supply device is increased and the size and weight of the entire thermal printer are increased.

[0006] The thermal energy generated from the thermal head cannot be entirely used for recording, and a part of the thermal energy is surplus thermal energy not used for recording. This surplus heat energy becomes useless heat energy, and is stored in the thermal head or dissipated. In the three-head one-pass method, since the number of thermal heads is three, surplus thermal energy generated during color recording becomes very large,
There is also a problem that the color thermal printer becomes hot.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a color thermal printer capable of saving energy and reducing the size of a three-head one-pass type thermal printer.

[0008]

In order to achieve the above object, in the color thermal printer of the present invention, any two of the first to third thermal heads for selectively coloring each thermal coloring layer are provided. Place the thermal heads close to each other, or connect them with a material with good thermal conductivity, and use the thermal head with the higher heating temperature range to reduce the excess heat energy generated during color recording by the thermal head with the lower heating temperature range. Is used as heat energy during color recording of the thermal head. In the second aspect, the material having good thermal conductivity is made of iron having two thermal heads attached thereto,
An aluminum or copper head support was used.

[0009]

FIG. 1 schematically shows a color thermal printer according to the present invention. A roll magazine 3 is removably mounted on the color thermal printer 2, and a long color thermal recording paper 4 is contained in the roll magazine 3.
The thermosensitive recording paper roll 6 is wound around the core 5. A rotary shaft 7 that is inserted into the core 5 and holds the thermosensitive recording paper roll 6 is mounted on the roll magazine 3. When the roll magazine 3 is set, the rotating shaft 7 is connected to a motor 8 via a gear train (not shown). The drive of the motor 8 causes the thermal recording paper roll 6 to rotate, and the color thermal recording paper 4 is rotated. Roll out.

As shown in FIG. 4, the color thermosensitive recording paper 4 is provided with a cyan thermosensitive coloring layer 52, a magenta thermosensitive coloring layer 53, a yellow thermosensitive coloring layer 54, and a protective layer 55 in this order on a support 51. ing. Cyan thermosensitive coloring layer 52
Has the lowest thermal sensitivity and develops cyan when high thermal energy is applied. The magenta thermosensitive coloring layer 53 has a medium thermal sensitivity, and develops magenta color by heating. The magenta thermosensitive coloring layer 53 loses its coloring ability when irradiated with ultraviolet rays near 365 nm, and a recorded magenta image is fixed. Yellow thermosensitive coloring layer 5
No. 4 has the highest heat sensitivity and develops yellow by the smallest heat energy. This yellow thermosensitive coloring layer 54
When a near ultraviolet ray near 420 nm is irradiated, the color developing ability is lost and the recorded yellow image is fixed.

Three platen rollers 11, 12, and 13 are arranged in a substantially U-shaped conveyance path. A first cutter 14 and a second cutter 15 are provided at the uppermost stream and the lowermost stream of the transport path, respectively. In the transport path, there are five pairs of transport rollers 16 to transport the color thermal recording paper 4.
20 are provided. These transport roller pairs 16 to 20
Is composed of a capstan roller driven by a motor, and a pinch roller movable between a nip position for nipping the color thermal recording paper 4 and an open position. Further, guide rollers 21 and 22 are provided at the bent portion of the transport path.

The motor 24 rotates the pair of conveying rollers 16 and 17. The motor 25 rotates the transport roller pair 18, and the motor 26 rotates the transport roller pairs 19 and 20.

On the opposite side of each of the platen rollers 11 to 13, a thermal head 27 for yellow, a thermal head 28 for magenta, and a thermal head 29 for cyan are provided. Corresponding to the coloring energy (see FIG. 5) of each of the thermosensitive coloring layers 52 to 54, the yellow thermal head 27,
The heat generation temperature is higher in the order of the magenta thermal head 28 and the cyan thermal head 29. Each of the thermal heads 27 to 29 is mounted on a head support 27a to 29a, and is provided with a heating element array in which a plurality of heating elements are arranged in a line.

The thermal head 27 for yellow and the thermal head 29 for cyan are integrally connected by a connecting member 31 made of a material having good thermal conductivity for efficiently transmitting heat. A heat insulating material 32 for preventing heat radiation from the connecting member 31 is wound around the connecting member 31. As a result, surplus thermal energy (hereinafter referred to as surplus heat) generated during color recording with the cyan thermal head 29 having the highest heat generation temperature range and not used for color recording.
Is transmitted to the yellow thermal head 27 having a low heat generation temperature range via the thermally conductive connecting member 31. The temperature of the yellow thermal head 27, to which the residual heat from the cyan thermal head 29 has been transmitted, rises by the amount of the residual heat, and the power required to generate heat in the heating element array is saved.

The yellow thermal head 27 is provided with a temperature sensor 33 for detecting the temperature that has increased due to the residual heat from the cyan thermal head 29. The connecting member 31 may be made of any material having good thermal conductivity, and examples thereof include iron, aluminum, and copper. These metals are low-cost in the order of iron, aluminum and copper, and the thermal conductivity is higher in the order of copper, aluminum and iron, so aluminum is preferred. The connecting member 31
The thermal support may be formed integrally with each thermal head using the same material as the material constituting the head support table. Alternatively, the thermal support may be formed using a different material from the thermal head. May be attached.

A yellow fixing lamp 35 is disposed between the yellow thermal head 27 and the magenta thermal head 28, and a magenta fixing lamp is disposed between the magenta thermal head 28 and the cyan thermal head 29. 36 are provided. Yellow fixing lamp 3
Reference numeral 5 includes a rod-shaped ultraviolet lamp 35a having a light emission peak of approximately 420 nm and a reflector 35b, and the yellow thermosensitive coloring layer 54 loses its coloring ability. The magenta fixing lamp 36 includes an ultraviolet lamp 36a having a light emission peak of approximately 365 nm and a reflector 36b, and causes the magenta thermosensitive coloring layer 53 to lose its coloring ability.

Photo sensors 37 to 39 for detecting the leading end of the color thermosensitive recording paper 4 are provided in front of the thermal heads 27 to 29, respectively. The number of drive pulses of the pulse motor is counted from the time when the leading edge is detected, and it is determined whether or not the leading edge of the recording area of the color thermal recording paper 4 has reached the thermal heads 27 to 29 based on the count value. Can be. Similarly, each cutter 1
Photo sensors 41 and 42 are provided in front of 4 and 15, respectively. The controller 44 counts the number of drive pulses of the pulse motor based on signals from each sensor and the like, and, at an appropriate timing,
29, control the operation of the cutters 14, 15;

An electronic still camera, a color scanner, or the like is connected to the color thermal printer, and the input blue, green, and red video signals are converted into yellow, magenta, and cyan images by digital conversion and color conversion processing. It is converted into data and stored in a frame memory (not shown) for each color. The three-color image data sequentially read line by line from each of the frame memories is used for driving the thermal heads 27 to 29 for yellow,
The signals are sent to magenta and cyan drive signal generation circuits (not shown). Then, from the drive signal generation circuits for each color,
The driving pulses of the number corresponding to the density of the image data are generated to drive the heating elements of the thermal heads 27 to 29.

The color recording of one pixel of each color is shown in FIG.
As shown in FIG. 2A, the heating includes bias heating and gradation heating. In the bias heating, each heating element is driven by a bias drive pulse and gives bias thermal energy immediately before a color to be printed is developed. In this embodiment, one bias heating drive pulse having a long pulse width is used, but a fixed number of bias heating drive pulses may be used instead. In the gradation heating, a number of gradation heating drive pulses corresponding to the image data representing the gradation level are used, and the color to be printed is colored to a predetermined density.

The operation of the color thermal printer having the above configuration will be described with reference to an example in which a plurality of full-color images are continuously printed. First, yellow image data, magenta image data, and cyan image data of an image to be printed are written in a frame memory (not shown). The rotation of the rotating shaft 7 in the clockwise direction in FIG.
Is sent out into the transport path. When the leading end of the color thermal recording paper 4 reaches the photo sensor 41, the transport roller pair 16 starts rotating, and nips and transports the thermal color recording paper 4.

When the leading end of the color thermosensitive recording paper 4 passes through the first cutter 14 and reaches the photo sensor 37, the number of driving pulses of the pulse motor is counted. The leading end of the color thermal recording paper 4 is the thermal head 2 for yellow.
7 and is nipped by a pair of transport rollers 17. The transport roller pair 17 transports the color thermosensitive recording paper 4 at a predetermined speed. If it is determined from the number of drive pulses during this conveyance that the leading end of the recording area has reached the heating element array, color recording of a yellow image is started.

FIG. 3 is a flowchart simply showing color recording of one line of a yellow image. When generating a drive signal for driving the yellow thermal head 27 based on one line of yellow image data,
The temperature of the yellow thermal head 27 detected by the temperature sensor 33 is used. Then, the yellow driving signal is corrected in consideration of the temperature rise of the yellow thermal head 27 due to the residual heat transmitted from the cyan thermal head 29 via the connecting member 31.

However, since the cyan thermal head 29 is not driven before the leading end of the color thermal recording paper 4 reaches the cyan thermal head 29, the yellow thermal head 27 does not rise in temperature due to residual heat. . In this case, a yellow drive signal for driving the yellow thermal head 27 drives the heating element of the yellow thermal head 27 with a drive signal without correction by residual heat, for example, as shown in FIG. . Then, a yellow image is color-recorded one line at a time in the recording area of the color thermosensitive recording paper 4.

When the color-recorded portion of the yellow image reaches the yellow fixing lamp 35, the ultraviolet lamp 35a
The near ultraviolet light having an emission peak of about 420 nm emitted from the recording paper of the color thermosensitive recording paper 4 is irradiated. This 4
The diazonium salt remaining in the yellow thermosensitive coloring layer 54 is decomposed by the ultraviolet light of 20 nm, the coloring ability is lost, and the yellow image recorded with the coloring is fixed.

The color thermosensitive recording paper 4 is guided by guide rollers 21
Is sent to the magenta thermal head 28. Then, when the leading end of the color thermosensitive recording paper 4 reaches the photo sensor 38, the counting of the driving pulses of the pulse motor is started as in the case of the yellow image recording. The leading end of the recording area is the magenta thermal head 28.
Is determined, the heating element of the magenta thermal head 28 is driven by the drive signal of the magenta image, and the magenta image is color-recorded line by line in the recording area.

While the color thermosensitive recording paper 4 is being conveyed at a constant speed by the conveying roller 18, the leading end of the color thermosensitive recording paper 4 on which the magenta image is color-developed is guided by the guide roller 22 based on the count value of the driving pulse. When it is determined that the light reaches the magenta fixing lamp 36 after that, near-ultraviolet light having an emission peak of approximately 365 nm is applied, and the magenta heat-sensitive coloring layer 53 loses its coloring ability and the magenta image is fixed.

After the magenta image is fixed, when the leading end of the color thermosensitive recording paper 4 reaches the photo sensor 39, counting of the number of drive pulses is started. The leading end of the recording area of the color thermal recording paper 4 is the thermal head 28 for cyan.
Is reached, the heating element of the cyan thermal head 29 is driven by the drive signal of the cyan image, and the cyan image is color-recorded on the color thermosensitive recording paper 4 line by line.

When a plurality of full-color images are continuously printed as in this embodiment, even when the cyan thermal head 29 is performing color recording, the yellow thermal head 27 is also positioned at the rear. Color recording of the recording area is performed simultaneously.

Since the thermal head 27 for yellow and the thermal head 29 for cyan are connected by the connecting member 31 having good thermal conductivity, the thermal head 29 for cyan generates more residual heat due to the high heat generation temperature. As shown by a broken arrow T in FIG. 1, the residual heat is transmitted toward the yellow thermal head 27 having a low heat generation temperature.

The temperature of the thermal head 27 for yellow did not rise due to residual heat until the leading end of the color thermal recording paper 4 did not reach the thermal head 29 for cyan.
When the cyan thermal head 29 starts driving, the temperature of the yellow thermal head 27 rises by the amount of residual heat transmitted via the connecting member 31. A bias signal for yellow in which the thermal energy of bias heating is reduced as a residual heat correction by this temperature rise is created (FIG. 2).
(B)).

The heating element of the thermal head 27 is driven by the corrected yellow bias signal, and a yellow image is recorded for each line. in this way,
Since the bias thermal energy for yellow can be reduced by utilizing the residual heat of the cyan thermal head 29, the power consumption of the color thermal printer 2 can be reduced. Further, the amount of generated heat of the entire color thermal printer 2 is also reduced. Since the residual heat correction is performed by reducing the leading portion of the bias heating pulse, even after performing the residual heat correction, the bias heating and the gradation heating are separated, and the bias heating becomes insufficient. Never.

When the leading end of the color thermosensitive recording paper 4 on which the recording of the full-color image has been completed in the above steps reaches the photosensor 42, the counting of the motor drive pulses is started. When the count value reaches a value corresponding to the length of one sheet of recording paper, the second cutter 15 operates to cut the color thermosensitive recording paper 4 into the length of one sheet. The one cut recording paper sheet is discharged from the paper discharge port 49.

When the color thermosensitive recording paper 4 having a length corresponding to the number of sheets designated in advance is fed out from the thermosensitive recording paper roll 6, the first cutter 14 operates to cut the color thermosensitive recording paper 4. Thereafter, when a full-color image is recorded in the last recording area of the cut color thermosensitive recording paper 4 and then discharged from the paper discharge port 49, color recording of a plurality of continuous full-color images is completed.

In the above-described embodiment, the thermal head 27 for yellow and the thermal head 29 for cyan are connected using the connecting member 31, but other than this, for example, as shown in FIG. Thus, the cyan thermal head 62 is disposed close to the side of the yellow thermal head 61, and as shown by the thick arrow in the drawing, the residual heat generated by the cyan thermal head 62 having a high recording temperature is removed by air. The light may be transmitted to the yellow thermal head 61 having a low recording temperature via the inside.

As shown in FIG. 6B, the thermal head 63 for magenta and the thermal head 64 for cyan are connected by a connecting member 65, and the thermal head 64 for cyan is connected.
May be transmitted to the magenta thermal head 63 for use as indicated by the thick arrow in the drawing. In addition, any combination may be used as long as the residual heat is transmitted from the thermal head having the high recording temperature to the thermal head having the low recording temperature. Arrangement may be used. Further, the heat insulating material does not have to be particularly provided.

[0036]

As described above, according to the color thermal printer of the present invention, any two of the first to third thermal heads are arranged close to each other, The thermal head with the higher heat-generating temperature range is used as the thermal energy for color-recording recording of the thermal head with the lower heat-generating temperature range. Therefore, power consumption for driving the thermal head is reduced. In addition, by this energy saving,
Since the power supply device can be small, it is possible to reduce the size and weight of the entire color thermal printer.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a color thermal printer of the present invention.

FIG. 2 is a waveform diagram showing an example of a drive signal for one line.

FIG. 3 is a flowchart illustrating color recording of one line of a yellow image.

FIG. 4 is an explanatory diagram showing an example of a layer structure of a color thermosensitive recording paper.

FIG. 5 is a graph showing the relationship between the heat energy of each thermosensitive coloring layer and the coloring density.

FIG. 6 is an explanatory diagram showing another embodiment.

[Explanation of symbols]

 2 Color Thermal Printer 4 Color Thermal Recording Paper 27 Thermal Head for Yellow 29 Thermal Head for Cyan 31 Connecting Member 32 Insulation Material

Claims (2)

[Claims] 1. A color thermosensitive recording paper provided with first to third thermosensitive coloring layers having different thermal sensitivities and colors to be formed, and first to third selective coloring recording of each thermosensitive coloring layer. A first thermal head having the lowest heat generation temperature range while moving the color thermosensitive recording paper in a fixed direction, comprising a thermal head and first and second ultraviolet lamps provided between the thermal heads; The uppermost first heat-sensitive coloring layer having the highest thermal sensitivity is color-recorded, and after this color-recording recording, ultraviolet light having a wavelength specific to the first heat-sensitive coloring layer is applied to the first heat-sensitive coloring layer.
The light is fixed by irradiating with an ultraviolet lamp, and then the second heat-sensitive coloring layer having a medium heat sensitivity is color-recorded by a second thermal head having a medium heating temperature range. UV light having a wavelength specific to the heat-sensitive coloring layer is irradiated with a second UV lamp and fixed by light. Finally, the third thermal head having the highest heat generation temperature range has the lowest thermal sensitivity in the lowermost layer. In a three-head one-pass type color thermal printer for color-recording a low third thermal color-forming layer, any two of the first to third thermal heads are arranged close to each other, or The excess thermal energy generated during color recording by a thermal head with a higher heat generation temperature range, which is linked by a material with good thermal conductivity, is used as the heat energy for color recording of a thermal head with a lower heat generation temperature range. A color thermal printer characterized by being used. 2. A color thermal printer according to claim 1, wherein said material having good thermal conductivity is an iron, aluminum, or copper head support on which two thermal heads are mounted.