JP2002059576A - Color thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color thermal printer which can irradiate a fixing light having a large quantity of light without making a power supply device large in size. SOLUTION: A counter 58 monitors a transfer position of a color thermal recording paper by counting driving pulses of a transfer motor 16. Ultraviolet lamps 31-33 for yellow are turned on by lamp illuminance adjustment circuits 51-53 in an order whereby the color thermal recording paper reaches an ultraviolet illumination region, thereby fixing a recorded yellow image. Since the three ultraviolet lamps 31-33 are shifted in an illumination start timing, a rush current is prevented from being too large and the three lamp illuminance adjustment circuits 51-53 can be driven by the power supply device 60 of a small capacity. Three ultraviolet lamps 41-43 for magenta are also turned on by lamp drivers 54-56 in an order whereby the color thermal recording paper reaches an ultraviolet illumination region, fixing a recorded magenta image. The ultraviolet lamps 31-33 and 41-43 are sequentially turned off as the color thermal recording paper passes.

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 which irradiates light from a lamp to optically fix color thermal recording paper.

[0002]

2. Description of the Related Art In a color thermal printer, a color thermal recording paper is used, and a full-color image is recorded sequentially in three color planes. This color thermosensitive recording paper is provided with a cyan thermosensitive coloring layer, a magenta thermosensitive coloring layer, and a yellow thermosensitive coloring layer in this order on a support. The yellow thermosensitive coloring layer, which is the uppermost layer, has the highest thermal sensitivity, and the lowermost layer. Is the lowest heat sensitivity of the cyan thermosensitive coloring layer. Each thermosensitive coloring layer is recorded in order from the uppermost layer. However, when recording the magenta thermosensitive coloring layer, near-ultraviolet light of 420 nm after the yellow image is recorded so that uncolored components in the yellow thermosensitive coloring layer do not develop color. To fix the light. Similarly, after recording of the magenta thermosensitive coloring layer, 36
The magenta heat-sensitive coloring layer is light-fixed by irradiating ultraviolet rays of 5 nm.

In order to generate ultraviolet light for light fixing, an ultraviolet lamp having a center wavelength of 420 to 450 nm for yellow fixing and a center wavelength of 365 for magenta fixing are used.
nm ultraviolet lamp is used. Further, generally, for yellow fixing and magenta fixing, respectively, 1 to 2
A book ultraviolet lamp is arranged.

[0004] In color thermal printers, there is a demand for higher printing speed. One of the methods for increasing the printing speed is to shorten the light fixing time. In order to shorten the light fixing time, the fixing energy may be increased, and it is conceivable to increase the number of ultraviolet lamps and the amount of ultraviolet irradiation.

[0005]

However, in the conventional color thermal printer, the ultraviolet lamps of the same wavelength range are simultaneously turned on or off by one lamp driving circuit. It is difficult to drive multiple UV lamps due to voltage limitations. Therefore, if a plurality of lamp driving circuits are provided, the number of ultraviolet lamps can be increased. However, when the ultraviolet lamp is turned on, the current value increases instantaneously due to the occurrence of an inrush current, so that driving a plurality of lamp driving circuits at the same time requires a large driving power, without using a large power supply device. Must not be.

The present invention has been made in consideration of the above circumstances, and has as its object to provide a color thermal printer capable of irradiating a large amount of fixing light without increasing the size of a power supply device.

[0007]

In order to achieve the above object, a color thermal printer according to the present invention is arranged side by side on a moving path of a color thermal recording paper, and includes at least two color thermal recording papers grouped by one or two. A plurality of rod-shaped lamps, a plurality of lamp driving circuits provided corresponding to each of the groups, for turning on or off the lamps in the group, and a power supply for supplying lamp driving power to each of the plurality of lamp driving circuits The apparatus includes a device and a lamp drive control unit that controls each lamp drive circuit in accordance with the position of the moving color thermal recording paper and turns on the color thermal recording paper sequentially from the group that has reached the light irradiation area. .

According to a second aspect of the present invention, in the color thermal printer, the lamp drive control section turns off the color thermal recording paper in order from the group that has passed through the light irradiation area.

[0009]

FIG. 1 shows the configuration of a color thermal printer embodying the present invention. The sheet-like color thermal recording paper 10 is stacked in a paper feed tray 11. A paper feed roller 12 is provided above the paper feed tray 11, rotates at the start of printing, and sends out the color thermal recording paper 10 at the top from the paper feed path 13.
Color thermal recording paper 10 sent out from paper feed path 13
Is nipped by a conveying roller pair 14 composed of a nip roller 14a and a driving roller 14b,
From the paper discharge passage 15 to the paper discharge passage 15 side.
The paper is alternately conveyed in the opposite direction from the paper feed tray 11 side. The drive roller 14b is rotated by the transport motor 16.

FIG. 2 shows an example of the layer structure of the color thermosensitive recording paper 10. The color thermosensitive recording paper 10 is formed by layering a cyan thermosensitive coloring layer 21, a magenta thermosensitive coloring layer 22, a yellow thermosensitive coloring layer 23, and a protective layer 24 in this order on a support 20. Each of the thermosensitive coloring layers 21 to 23 is provided from the surface side in the order of thermal recording. For example, when thermal recording is performed in the order of magenta, yellow, and cyan, the yellow thermosensitive coloring layer 23 and the magenta thermosensitive coloring are used. Layer 22
And the positions are swapped. An intermediate layer (not shown) is provided between the layers.

The yellow thermosensitive coloring layer 23 loses its coloring ability when irradiated with near ultraviolet rays near 420 nm.
Further, the magenta thermosensitive coloring layer 22 loses its coloring ability when irradiated with 365 nm ultraviolet rays.

In FIG. 1, a platen roller 17 and a thermal head for recording an image by pressing and heating the color thermosensitive recording paper 10 supported on the platen roller 17 are provided between a paper feeding path 13 and a conveying roller pair 14. 18 are provided. As is well known, the thermal head 18 has a large number of heating elements arranged in a line, and generates thermal energy according to a color to be thermally recorded and its color density.

A yellow light fixing device 30 and a magenta light fixing device 40 are provided between the conveying roller pair 14 and the paper discharge path 15.
Is arranged. The yellow light fixing device 30 includes three rod-shaped ultraviolet lamps 31, 32, and 33 arranged in parallel.
And a reflector 34 that covers the back.
The reflector 34 has a substantially U-shaped cross section. The inner wall of the reflector 34 is a reflection surface, and reflects the light emitted to the back side of the ultraviolet lamps 31, 32, 33 toward the color thermosensitive recording paper 10 side. Since the magenta optical fixing device 40 has the same configuration as the yellow optical fixing device 30, only reference numerals are given.

The reflector 34 of the optical fixing unit 30 for yellow
Holes are formed in the upper wall at positions opposing the ultraviolet lamps 31, 32, and 33, and illuminance sensors 35, 36, and 37 are provided in these holes, respectively. The illuminance sensors 35, 36, 37 are provided with ultraviolet lamps 31, 32,
Measure the illuminance of ultraviolet light emitted from each of the 33,
Outputs the measured illuminance signal.

UV lamps 31, 32, 33 for yellow
Is approximately 420 nm, and ultraviolet lamps 41 and 4 for magenta.
2, 43 emit ultraviolet light having an emission peak at about 365 nm and irradiate the color thermosensitive recording paper 10.

In the color thermal printer having the above configuration, when printing a yellow image and a magenta image, thermal recording and optical fixing are simultaneously performed while the color thermal recording paper 10 is transported in the forward direction, respectively. The color thermosensitive recording paper 10 is conveyed in the reverse direction to prepare for printing of the next image.
When printing a cyan image, the color thermosensitive recording paper 10
Is transported in the forward direction, and thermal recording is not performed in the reverse direction. The transport speed of the color thermosensitive recording paper 10 in the forward direction depends on the thermosensitive coloring layer 21 to be thermally recorded.
Are determined in advance in accordance with the thermal sensitivities of No. to No. 23. At the start of printing, the thermal head 18 is set at a position away from the platen roller 17. Also,
The yellow UV lamps 31, 32, and 33 are turned on during printing of the yellow image, and the magenta UV lamps 41, 4 are turned on.
Reference numerals 2 and 43 light during printing of a magenta image and printing of a cyan image.

At the time of light fixing of the yellow thermosensitive coloring layer 23,
If the irradiation amount of the ultraviolet rays is too large, the magenta heat-sensitive coloring layer 22 is also partially fixed and its coloring characteristics are changed. Therefore, the light emission amounts of the yellow ultraviolet lamps 31, 32, and 33 are controlled, and the total irradiation of the ultraviolet rays is performed. The light amount is adjusted so as to be constant. In the light fixing of the magenta heat-sensitive coloring layer 22, only the insufficient fixing becomes a problem. Therefore, the magenta ultraviolet lamps 41, 42, and 43 do not control the light emission amount and use a drive pulse having a duty ratio of 100%. Fully lit.

FIG. 3 shows an electrical configuration of the color thermal printer. The CPU 50 for controlling the operation of the color thermal printer includes three lamp illuminance adjustment circuits 51 and 5.
2, 53 and three lamp drivers 54, 55, 56
And the motor driver 57 are connected. Lamp illuminance adjustment circuits 51, 52, 53 and lamp driver 5
4, 55, and 56 are supplied with driving power from a power supply device 60.

The lamp illuminance adjustment circuits 51, 52, 53
The drive circuit turns on or off the yellow ultraviolet lamps 31, 32, and 33, and adjusts the amount of light emitted by the ultraviolet lamps 31, 32, and 33 being turned on. Each of the lamp illuminance adjustment circuits 51, 52, and 53 includes an illuminance sensor 3
Measurement illuminance signals from 5, 36 and 37 are input.

The lamp illuminance adjustment circuit 51 includes a sensor amplifier 61, a comparator 62, a ROM 63, an integrator 64, and an inverter 65. The illuminance signal measured by the illuminance sensor 35 is input to a sensor amplifier 61, where the illuminance signal is converted into illuminance data by voltage conversion.
Is input to The comparator 62 calculates a difference between the illuminance value measured by the illuminance sensor 35 and the target illuminance value written in the ROM 63, and sends the difference signal to the integrator 64. The integrator 64 determines the light emission amount of the ultraviolet lamp 31 based on the difference signal, and outputs a drive signal corresponding to the light emission amount to the inverter 65. The inverter 65 adjusts the duty ratio of the drive pulse of the ultraviolet lamp 31 according to the drive signal. The lamp illuminance adjustment circuits 52 and 53 have the same configuration as the lamp illuminance adjustment circuit 51, and the illuminance sensors 36 and 37
UV lamps 32, 3 based on the measured illuminance signal from
The light emission amount of No. 3 is adjusted. The ultraviolet lamps 31 and 3
The target illuminance values of 2, 33 are the conveying speed of the color thermosensitive recording paper 10 during the thermal recording and light fixing of the yellow image, the length of the ultraviolet irradiation area in the entire yellow light fixing device 30, and the ultraviolet lamps 31 to 33. Is determined so that the total irradiation amount of ultraviolet light to the color thermosensitive recording paper 10 becomes a constant amount necessary for fixing the yellow thermosensitive coloring layer 23.

UV lamps 41, 42, 43 for magenta
Are the lamp drivers 54, 5 without controlling the illuminance.
Lighting is performed by a driving pulse having a duty ratio of 100% by 5,56.

As the transport motor 16, a pulse motor is used. The motor driver 57 sends a signal indicating the rotation direction and a drive pulse to the transport motor 16 to adjust the rotation direction and the rotation speed. The drive pulse and the signal in the rotation direction are sent to the counter 58, and the drive pulse is added or subtracted according to the rotation direction. The counter 58 measures the position of the color thermosensitive recording paper 10.

The ROM 59 stores the ultraviolet lamp 3 from the point in time when the color thermosensitive recording paper 10 is conveyed in the forward direction.
The number of pulses until the recording area of the color thermosensitive recording paper 10 passes through each ultraviolet irradiation area and the number of pulses until the recording area of the color thermosensitive recording paper 10 passes each ultraviolet irradiation area are written. The CPU 50 monitors the content of the counter 58, and generates a detection signal every time the count value reaches the number of pulses stored in the ROM 59.

The CPU 50 controls the lamp illuminance adjusting circuits 51 to 53 or the lamp drivers 54 to 5 based on each signal.
6 is controlled, and the ultraviolet lamps 31 to 3 for yellow are controlled.
3, or the magenta ultraviolet lamps 41 to 43 are turned on and off. Each ultraviolet lamp 31-33, 41-43,
The color thermosensitive recording paper 10 is turned on in the order in which it reaches each ultraviolet irradiation area, and is turned off in the order in which the color thermosensitive recording paper 10 passes through the ultraviolet irradiation area.

Next, the operation of the present embodiment will be described.
When print is instructed, a print preparation operation is performed. First, the paper feed roller 12 rotates, and the paper feed tray 11 is rotated.
The color thermosensitive recording paper 10 stacked on the uppermost portion is sent out from the paper feed path 13. When the leading end of the color thermosensitive recording paper 10 passes between the thermal head 18 and the platen roller 17 and enters the transport roller pair 14, the rotation of the paper feed roller 12 is stopped. During the feeding of the color thermosensitive recording paper 10, the thermal head 18 is set at a position away from the platen roller 17.

After the completion of the printing preparation operation, the thermal head 18 is moved to a position where the thermal head 18 presses the color thermal paper 10. The color thermosensitive recording paper 10 is nipped by the nip roller 14a and the driving roller 14b, and thereafter, the driving roller 14b is rotated by the transport motor 16 to determine the color thermosensitive recording paper 10 according to the thermal sensitivity of the yellow thermosensitive coloring layer 23. Is transported in the forward direction at the given constant speed. While the transport motor 16 is rotating, the drive pulse is
Counted by.

The color thermal recording paper 10 is the thermal head 1
8, the yellow image is recorded line by line. In the thermal recording of the yellow image, each heating element of the thermal head 18 generates thermal energy according to the coloring characteristics and coloring density of the yellow thermosensitive coloring layer 23.

As shown in FIG. 4, the color thermosensitive recording paper 10
The CPU 50 reaches the UV irradiation area of the ultraviolet lamp 31 when the count value of the counter 58 reaches C1.
Generates the detection signal SS1 by referring to the ROM 59. At this timing, the CPU 50 drives the lamp illuminance adjustment circuit 51 to turn on the ultraviolet lamp 31.

Subsequently, when the color thermosensitive recording paper 10 is conveyed and its leading end reaches the ultraviolet irradiation area of the ultraviolet lamp 32 and the count value reaches C2, a detection signal SS2 is generated. As a result, the lamp illuminance adjustment circuit 52 is driven, and the ultraviolet lamp 32 is turned on. When the leading end of the color thermosensitive recording paper 10 reaches the ultraviolet irradiation area of the ultraviolet lamp 33 and the count value reaches C3, a detection signal SS3 is generated, and the ultraviolet lamp 33 is turned on by the lamp illuminance adjustment circuit 53.

During the operation of the ultraviolet lamp 31, the illuminance sensor 35 measures the illuminance of the ultraviolet lamp 31. The measured illuminance signal from the illuminance sensor 35 is input to the comparator 62 after being converted into illuminance data by voltage conversion in the sensor amplifier 61. The comparator 62 calculates a difference between the measured illuminance value and the target illuminance value, and sends the difference signal to the integrator 64. The integrator 64 determines the light emission amount of the ultraviolet lamp 31 based on the difference signal, and outputs a drive signal corresponding to the light emission amount to the inverter 65. The inverter 65 adjusts the duty ratio of the drive pulse of the ultraviolet lamp 31 according to the drive signal. As a result, the illuminance of the ultraviolet lamp 31 is adjusted near the target illuminance.

Similarly, the illuminances of the ultraviolet lamps 32 and 33 are adjusted to near the target illuminance based on the illuminance values measured by the illuminance sensors 36 and 37.

The color thermosensitive recording paper 10 on which the yellow image is recorded is fixed while passing through the ultraviolet irradiation area of the ultraviolet lamps 31 to 33 for yellow. UV lamps 31 to
Numeral 33 emits ultraviolet light having a wavelength of approximately 420 nm, and causes the coloring ability of the yellow thermosensitive coloring layer 23 to disappear. At this time, the illuminance of the ultraviolet rays radiated from the ultraviolet lamps 31 to 33 is
Since the respective illuminances are adjusted in the vicinity of the target illuminance, the entire surface of the color thermosensitive recording paper 10 is uniformly light-fixed without causing irradiation unevenness of ultraviolet rays.

In printing the yellow image, three ultraviolet lamps 31, 32, and 33 for yellow are turned on.
Since the lighting start timings of these ultraviolet lamps 31 to 33 are shifted, the driving timings of the three lamp illuminance adjustment circuits 51 to 53 are also shifted, and the rush current does not become too large. As a result, the three lamp illuminance adjustment circuits 51 to 53 can be driven without using a large power supply device.
33, it is possible to irradiate the color thermosensitive recording paper 10 with a large amount of ultraviolet rays. Therefore, the amount of ultraviolet light necessary for fixing the yellow image can be irradiated in a short time, and in this embodiment, the light can be sufficiently fixed during the forward conveyance.

When the rear end of the color thermosensitive recording paper 10 passes through the thermal head 18, the recording of the yellow image is completed.
The thermal head 18 moves to a position away from the color thermosensitive recording paper 10.

When the end of the recording area of the color thermosensitive recording paper 10 passes through the ultraviolet irradiation area of the ultraviolet lamp 31 and the count value of the counter 58 becomes C4, the CPU 50 generates a detection signal SE1 (see FIG. 4). with this timing,
The CPU 50 stops driving the lamp illuminance adjustment circuit 51 and turns off the ultraviolet lamp 31.

Subsequently, the color thermosensitive recording paper 10 is conveyed, and when the end of the recording area passes through the ultraviolet irradiation area of the ultraviolet lamp 32 and the count value becomes C5, the detection signal SE is output.
2 occurs. As a result, the driving of the lamp illuminance adjustment circuit 52 is stopped, and the ultraviolet lamp 32 is turned off. Also,
When the end of the recording area passes through the ultraviolet irradiation region of the ultraviolet lamp 33 and the count value becomes C6, a detection signal SE3 is generated, the driving of the lamp illuminance adjustment circuit 53 is stopped, and the ultraviolet lamp 33 is turned off.

When the rear end of the color thermosensitive recording paper 10 reaches the position of the pair of conveying rollers 14, the conveyance of the color thermosensitive recording paper 10 is stopped.

Next, the drive roller 14b is rotated in the reverse direction by the transport motor 16, and the color thermosensitive recording paper 10 is transported at a high speed in the reverse direction. When the leading end of the color thermosensitive recording paper 10 reaches the position of the pair of conveying rollers 14, the conveyance of the color thermosensitive recording paper 10 is stopped, and the printing of the yellow image is completed. At the time of this return, the counter 58 counts down.

Next, a magenta image is printed. The thermal head 18 is moved to a position where the thermal head 18 presses on the color thermal paper 10. Then, the driving roller 14 b is rotated by the conveying motor 16, and the color thermosensitive recording paper 10 is conveyed in the forward direction at a constant speed determined according to the thermal sensitivity of the magenta thermosensitive coloring layer 22.

The color thermal recording paper 10 is the thermal head 1
8, the magenta image is recorded line by line. In the thermal recording of the magenta image, each heating element of the thermal head 18 generates thermal energy according to the coloring characteristics and coloring density of the magenta thermosensitive coloring layer 22.

During the printing of the magenta image, the transport position of the color thermosensitive recording paper 10 is monitored based on the count number of the counter 58, as in the printing of the yellow image. When the leading end of the color thermosensitive recording paper 10 reaches the ultraviolet irradiation area of the ultraviolet lamp 41, the CPU 50 generates a detection signal. At this timing, the CPU 50 drives the lamp driver 54 to turn on the ultraviolet lamp 41 with a drive pulse having a duty ratio of 100%. Subsequently, the color thermosensitive recording paper 10 is conveyed, and each time the leading edge reaches each ultraviolet irradiation area of the ultraviolet lamps 42 and 43, the ultraviolet lamps 42 and 43 are sequentially turned on by a drive pulse having a duty ratio of 100%.

The color thermosensitive recording paper 10 on which the magenta image is recorded is optically fixed while passing through the magenta ultraviolet lamps 41 to 43. The ultraviolet lamps 41 to 43
It emits ultraviolet light having a wavelength of about 365 nm, so that the magenta thermosensitive coloring layer 22 loses its coloring ability.

Three magenta ultraviolet lamps 41 to 43
Also, since the respective lighting start timings are shifted, the rush current does not become too large.

When the rear end of the color thermosensitive recording paper 10 passes through the thermal head 18, the recording of the magenta image is completed.
The thermal head 18 moves to a position away from the color thermosensitive recording paper 10.

When the end of the recording area of the color thermosensitive recording paper 10 passes through the ultraviolet irradiation area of the ultraviolet lamp 41, the CPU 50 stops driving the lamp driver 54 based on the count value of the counter 58 and the position information of the ROM 59. Then, the ultraviolet lamp 41 is turned off. Subsequently, the color thermosensitive recording paper 10 is conveyed, and each time the end of the recording area passes through the ultraviolet irradiation area of the ultraviolet lamps 42 and 43, the driving of the lamp drivers 55 and 56 is stopped in order, and the ultraviolet lamps 42 and 43 are sequentially turned on. Turns off.

When the rear end of the color thermosensitive recording paper 10 reaches the position of the pair of conveying rollers 14, the conveyance of the color thermosensitive recording paper 10 is stopped.

Next, the drive roller 14b is rotated in the reverse direction, and the color thermosensitive recording paper 10 is conveyed at a high speed in the reverse direction. The leading end of the color thermal recording paper 10 is
Is reached, the conveyance of the color thermosensitive recording paper 10 is stopped, and the printing of the magenta image is completed.

Next, printing of a cyan image is started. The thermal head 18 moves to a position where the thermal head 18 presses on the color thermal paper 10. The color thermosensitive recording paper 10 is conveyed in the forward direction at a speed determined according to the thermal sensitivity of the cyan thermosensitive coloring layer 21, and a cyan image is recorded line by line by the thermal head 18. Although the cyan thermosensitive coloring layer 21 does not have light fixing property, the magenta ultraviolet lamps 41 to 43 are sequentially turned on and then turned off in order to bleach the color thermosensitive recording paper 10.

When the recording of the cyan image is completed, the color thermosensitive recording paper 10 on which the thermal recording has been performed is conveyed to the paper discharge passage 15 side and discharged to a paper discharge tray (not shown).

In the above-described embodiment, the method of counting the driving pulses of the transport motor is used to detect the transport position of the color thermal recording paper. May be provided.

Further, a lamp illuminance adjustment circuit or a lamp driver as a lamp driving circuit is provided for each of the six ultraviolet lamps, and the ultraviolet lamps are turned on or off one by one. May be simultaneously turned on or off by one lamp driving circuit.

Also, an example has been described in which three yellow ultraviolet lamps and three magenta ultraviolet lamps are provided. However, if the total driving power of the ultraviolet lamps is within the capacity of the power supply device, the number of lamps is further increased. It is also possible.

Further, when two lamps are provided for one color, the present invention is applied to turn on each lamp in order.
If the light is turned off, waste of power can be saved. Also, 1
When three lamps are provided for each color, they may be divided into two groups, one and two, and each group may be turned on and off in order.

The illuminance of the ultraviolet rays changes according to the temperature of the lamp tube wall. Therefore, the illuminance of the ultraviolet lamp is low immediately after lighting. Therefore, it is preferable to preheat by turning on the ultraviolet lamp during preparation for printing. In the case of an ultraviolet lamp that requires preheating of the filament, a necessary period is secured before the lighting timing to preheat.

[0055]

As described above, according to the present invention, the fixing lamps are respectively turned on when the color thermosensitive recording paper is conveyed, and the lighting start timing is shifted accordingly. , The rush current does not occur.
As a result, it is possible to drive a plurality of lamp driving circuits without using a large power supply device, and to irradiate a large amount of fixing light to the color thermosensitive recording paper with a plurality of lamps to increase a printing speed. Can be. Further, the lamps are sequentially turned off every time the color thermosensitive recording paper passes, so that there is no waste of power.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram showing a layer structure of a color thermosensitive recording paper.

FIG. 3 is a schematic diagram showing an electrical configuration of a color thermal printer embodying the present invention.

FIG. 4 is a timing chart showing output of a detection signal and lighting timing of an ultraviolet lamp.

[Explanation of symbols]

 Reference Signs List 10 color thermal recording paper 16 transport motor 18 thermal head 30 light fixing device for yellow 31, 32, 33 ultraviolet lamp for yellow 40 light fixing device for magenta 41, 42, 43 ultraviolet lamp for magenta 50 CPU 51, 52, 53 Lamp illuminance Adjustment circuit 54, 55, 56 Lamp driver 58 Counter 60 Power supply

Claims (2)

[Claims] 1. Using a color thermosensitive recording paper having a plurality of thermosensitive coloring layers formed on a support, and moving the color thermosensitive recording paper along a moving path, using a thermal head in order from the thermosensitive coloring layer on the front surface side. In a color thermal printer that performs thermal recording and irradiates a fixing light to a portion where an image is recorded to perform optical fixing, the color thermal printer is arranged side by side on a moving path of a color thermal recording paper, and is grouped by one or two. At least two rod-shaped lamps, a plurality of lamp driving circuits provided corresponding to each of the groups, for turning on or off the lamps in the group, and a driving power of the lamps for each of the plurality of lamp driving circuits. Controls each lamp drive circuit according to the power supply device to be supplied and the position of the color thermal recording paper being moved, from the group where the color thermal recording paper reaches the light irradiation area. Color thermal printer, characterized in that it comprises a lamp drive control unit for lighting the. 2. The color thermal printer according to claim 1, wherein the lamp drive control unit turns off the color thermal recording paper in order from the group in which the color thermal recording paper has passed the light irradiation area.