JPH1044604A - Color thermal recording method and color thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of fixing irregularity even when the luminous intensity of a fixing lamp is changed. SOLUTION: The luminous intensity of a fixing lamp is measured by an illuminance sensor and the feed speed of recording paper is changed corresponding to a change in luminous intensity so as to make the integrated aquantlty of fixing light constant. Therefore, the relation between the luminous intensity and a feed speed making the integrated quantity of fixing light constant is preliminarily calculated to be stored. Corresponsing to a case changed in luminous intensity as shown by (A), the feed speed of recording paper is regulated as shown by (B). Therefore, when luminous intensity is lowered, the feed speed of the recording paper becomes low corresponding thereto and uniform integrated fixing light quantity distribution is obtained as shown by (C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color thermal recording method and a color thermal printer.

[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. In this color thermosensitive recording paper, a cyan thermosensitive coloring layer, a magenta thermosensitive coloring layer, and a yellow thermosensitive coloring layer are sequentially provided on a base. 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, a purple color of 420 nm is recorded after the yellow image is recorded so that uncolored components in the yellow thermosensitive coloring layer are not colored. It is fixed by irradiating eyes. Similarly, after recording the magenta thermosensitive coloring layer, 3
The magenta thermosensitive coloring layer is fixed by irradiating 65 nm ultraviolet rays.

[0003]

By the way, the illuminance of the lamp used for fixing may be reduced after starting to be turned on as shown in FIG. 5A depending on the use environment, use time and the like. This decrease x in the illuminance is unstable, and is 0 to 100%.
Has the potential to change. Also, the time at which this reduction occurs is unstable. Therefore, in a system in which fixing is performed during thermal recording with a thermal head, there is a problem that unevenness in fixing occurs due to the decrease in illuminance. This fixing unevenness,
In the case of insufficient fixation, this portion develops color at the time of the next thermal recording, and in the case of excessive fixation, the layer for next thermal recording is also excessively fixed, deteriorating the coloring characteristics of this thermosensitive coloring layer. Would. As a result, there is a problem that color unevenness occurs.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a color thermal recording method and a color thermal printer capable of performing an even fixing even when a decrease in illuminance occurs in a fixing lamp.

[0005]

According to a first aspect of the present invention, there is provided a color thermosensitive recording method according to the first aspect, wherein the color thermosensitive recording paper is fed in different directions during thermal recording and during fixing. The illuminance of the fixing lamp is detected, and the feed speed of the color thermosensitive recording paper is changed in accordance with the change in the illuminance so that the integrated fixing light amount becomes constant.

According to a second aspect of the present invention, in the color thermal recording method, fixing is performed during feeding of the color thermal recording paper during thermal recording and during returning of the color thermal recording paper after the thermal recording. During the later return, the illuminance of the fixing lamp is detected, and the feed speed of the color thermosensitive recording paper is changed in accordance with the change in the illuminance so that the integrated fixing light amount becomes constant. In addition, it is preferable that most of the integrated fixing light amount required during the return after the thermal recording is fixed, and the remaining fixing is performed during the feeding of the thermal recording. When the second color component image is fixed, it is preferable that overfixing is set so that a portion with insufficient fixing light amount due to a decrease in illuminance of the fixing lamp does not occur.

According to the color thermal recording method of the present invention, the length between the heating element of the thermal head and the irradiation area of the fixing lamp is set longer than the length of the recording area. The fixing of the color thermosensitive recording paper is continued by performing the fixing.At the time of this fixing, the illuminance of the fixing lamp is detected, and the feeding speed of the color thermosensitive recording paper is changed in accordance with the change in the illuminance, so that the integrated fixing light amount is increased. It is intended to be constant.

According to a sixth aspect of the present invention, there is provided a color thermal printer, wherein a pair of transport rollers for nipping the color thermosensitive recording paper and alternately sending and pulling back, and a first roller disposed downstream of the transport roller pair in the delivery direction. A thermal head that records a yellow image in the recording area of the color thermosensitive recording paper at the time of the second retraction, records a magenta image at the time of the second retraction, and records a cyan image at the time of the third retraction; A first wavelength range light beam is radiated to the color thermosensitive recording paper passing through the fixing light beam irradiation area at the time of the second delivery after the first retraction to fix the yellow image. A fixing device for fixing a magenta image by irradiating a light beam in the second wavelength range at the time of the third sending after the second retraction, a sensor for measuring the illuminance of a fixing lamp during fixing, and a sensor for fixing the magenta image. Of varying the feeding speed of the recording paper on the basis of the illuminance change is the integrated fixing quantity of light that a feed speed control means to ensure a constant. In the second retraction, a yellow image is fixed by a fixing device, and in the third retraction, a magenta image is fixed by a fixing device. These fixings are performed by feeding a color thermosensitive recording paper at a constant speed. preferable. Also, the fixing performed by changing the feeding speed of the color thermosensitive recording paper covers most of the required integrated fixing light amount, and the fixing performed by feeding the color thermosensitive recording paper at a constant speed covers the remainder of the required integrated fixing light amount. Is preferable. After the recording of the magenta image, it is preferable that the magenta image is fixed and bleached while the ultraviolet ray in the second wavelength range is kept irradiated. The fixing device includes: a yellow fixing lamp that emits light in a first wavelength range; a magenta fixing lamp that emits light in a second wavelength range; and one of these two types of fixing lamps. And a lamp switching mechanism facing the area.

[0009]

As shown in FIG. 2, during printing, a color thermosensitive recording paper is pulled out from, for example, a recording paper roll, and sent out to the thermal head and the fixing device side by, for example, forward rotation of a pair of conveying rollers. After the leading end of the recording area of the color thermosensitive recording paper has passed the heating element of the thermal head, the feeding of the recording paper is stopped. Thereafter, the transport roller pair is reversed, and the first pullback of the color thermosensitive recording paper is started. During the first pullback, the thermal recording paper is pressed and heated by the thermal head, and a yellow image is recorded line by line in the recording area. After the yellow image is recorded, the pair of conveying rollers is rotated forward, and the color thermosensitive recording paper is fed again by a predetermined amount.

When the recording area passes through the fixing light beam irradiation area of the fixing area at the time of the sending, the yellow image is fixed by the yellow fixing lamp. In this fixing, as shown in FIG. 1, first, the illuminance of the yellow fixing lamp is measured by an illuminance sensor. The recording paper feed speed is determined based on the illuminance of the yellow fixing lamp. Then, the rotation speed of the pair of conveying rollers is changed based on the feed speed, and the speed is controlled so that the integrated fixing light amount becomes constant irrespective of the change in illuminance. That is, when the illuminance decreases, the rotation speed of the pair of conveying rollers decreases accordingly, and as a result, the integrated fixing light amount in this portion is made constant.

When the fixing of the yellow image is completed, a second retraction is performed, and the thermal recording paper is pressed and heated by the thermal head, so that the magenta image is recorded line by line in the recording area where the yellow image is fixed. Is done. Second
When the second retraction is completed, the conveying roller pair is rotated forward and the color thermosensitive recording paper is sent out. When sending this,
The magenta fixing lamp emits light and the magenta image is fixed. Also during this fixing, the illuminance of the magenta fixing lamp is measured, and the feeding speed of the recording paper is adjusted based on the illuminance so that the integrated fixing light amount becomes constant.

When the fixing of the magenta image is completed, the third pullback is performed, and the cyan image is recorded line by line in the recording area by the thermal head. After this recording, the transport roller pair rotates forward, and the color thermosensitive recording paper is fed. During the feeding, the magenta fixing lamp emits light, and the unrecorded portion is bleached. When the planned cutting line comes to the cutter position, the cutter operates to cut the recording paper on the planned cutting line, cut the recording paper into sheets, and discharge the sheets.

The fixing of the yellow image by the light beam in the first wavelength range and the magenta image by the light beam in the second wavelength range can be performed not only at the time of sending out but also at the time of the next pullback. Good. In this case, since the thermal recording is performed by the thermal head, the fixing at this time is not a variable speed fixing corresponding to a change in illuminance as at the time of sending out, but a constant speed fixing. In this case, variable speed fixing may cover most of the necessary integrated fixing light amount, for example, 70%, and the remaining 30% may be covered by constant speed fixing.
In this way, by obtaining most of the necessary integrated fixing light amount by the variable speed fixing, it is possible to reduce the degree of fixing unevenness due to the influence of the illuminance change. In addition, the printing time is shortened as a whole because the recording paper feed speed is faster than when fixing is performed only at the time of pullback. Also,
In the case of magenta fixing, since the next cyan heat-sensitive recording layer is not affected by overfixing, it is preferable to perform overfixing so that shortage of the integrated fixing light amount does not occur even if the illuminance is reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG.
Is rotatably housed in the magazine 11. A shutter 13 is provided inside the magazine near the exit 12 of the magazine 11.
And a paper feed roller pair 14 are provided. Shutter 13
The shutter 13 opens and closes the outlet 12, and in a storage state, the shutter 13 is urged by a spring material or the like to close the outlet 12, so that moisture is prevented and light is shielded. Magazine 11
When a paper feed instruction is issued after the printer is set in the thermal printer, the shutter 13 is displaced upward by the shutter opening mechanism 9 on the printer side, and the outlet 12 is opened. Instead of using the recording paper roll 10 stored in the magazine 11, a simple recording paper roll may be used. In this case, a paper feeding roller pair is separately provided instead of the paper feeding roller pair in the magazine. Can be

The feed roller pair 14 is rotated after the shutter 13 is set to the open state, and feeds the leading end of the recording paper 16 toward the transport roller pair 15. The feed roller pair 14 has a capstan roller on the upper side of the pair of rollers and a nip roller on the lower side.
The recording paper 16 is fed at the same feed speed. The roller shift mechanism 14a sets the paper feed roller pair 14 to a nip state in which the recording paper 16 is nipped when feeding the leading end of the recording paper 16 toward the transport roller pair 15, and thereafter ends the print sequence for one frame. Until the nip roller is separated from the capstan roller, the nip is released.

When the magazine 11 is set in the thermal printer, the paper feed roller pair 14 is driven to rotate by the motor on the printer side, whereby the leading end of the recording paper 16 is pulled out of the recording paper roll 10 and is fed to the transport roller pair 15. Sent to. As is well known, the recording paper 16 is provided with a cyan thermosensitive coloring layer, a magenta thermosensitive coloring layer, and a yellow thermosensitive coloring layer sequentially, and the uppermost yellow thermosensitive coloring layer has the highest thermal sensitivity. The yellow thermosensitive coloring layer loses its coloring ability by a violet visible light of 420 nm, and the magenta thermosensitive coloring layer loses its coloring ability by an ultraviolet ray of 365 nm.

The magazine 11 is made larger than the maximum winding diameter of the recording paper roll 10.
A gap is provided between the inner wall surface and the recording paper roll 10. In this gap, the recording paper 1 by the conveying roller pair 15 is provided.
At the time of retraction of 6, the returned portion is wound and loosened and stored.

The transport roller pair 15 includes a capstan roller 20, a nip roller 21, and an auxiliary nip roller 22. The nip roller 21 and the auxiliary nip roller 22 are configured to be displaced by a roller shift mechanism 23 between a nip position pressed against the peripheral surface of the capstan roller 20 and a retracted position away from the capstan roller 20.
The roller shift mechanism 23 is constituted by a solenoid. Alternatively, the nip rollers 21 and 22 may be shifted using a cam rotated by a motor. The transport roller pair 15 is brought into the nip release state by the shift mechanism 23 when the leading end of the recording paper 16 is transported from the paper feed roller pair 14, and is kept in the nip state after this paper supply until the print sequence is completed.

The transport roller pair 15 is connected to the exit 1 of the magazine 11
2 and a pair of transport rollers
5, the thermosensitive recording paper 16 is wound around the capstan roller 20, whereby the recording paper 16 is curved in a direction opposite to the curl due to being stored in a roll form.
The curl is corrected. Guide plates 24 and 25 are provided between the outlet 12 and the transport roller pair 15. When the paper feed roller pair 14 feeds paper, the leading end of the recording paper 16 is guided by the transport roller pair 15, When the paper 16 is pulled back, the recording paper 16 is returned into the magazine 11, and the recording paper 16 is stored in a loosened state as shown by a two-dot chain line in FIG.

A platen roller 30 and a thermal head 31 are arranged downstream of the transport roller pair 15. In this embodiment, the thermal head 31 is mounted in a fixed state. Further, the platen roller 30 is made of hard rubber and is rotatable. The platen roller 30 is mounted so as to be able to move up and down by an up-down mechanism 32, and is displaced upward to press the recording paper 16 against the heating element array 31 a of the thermal head 31 during thermal recording.

The heating element array 3 is provided on the thermal head 31.
1a is formed. This heating element array 31a
A large number of heating elements are formed in a line shape in the axial direction of the platen roller 30. At the time of thermal recording, each heating element is driven according to image data, thereby recording a full-color image in three color planes sequentially.

The cutter 3 is located downstream of the thermal head 31.
3 are arranged. The cutter 33 has a movable upper blade and a fixed lower blade. After recording the full-color image, the cutter 33 operates to cut the recorded portion into sheets. Further, a leading end sensor 34 for detecting the leading end of the recording paper 13 is provided near the transport roller pair 15 and downstream.

A fixing device 35 is arranged downstream of the cutter 33. The fixing device 35 includes a yellow fixing lamp 36 that emits violet visible light in a wavelength range of 420 nm,
A magenta fixing lamp 37 that emits ultraviolet light in a wavelength range of 65 nm and a lamp house 38 are provided. The lamp house 38 is rotated 180 degrees about a mounting shaft 38a by a motor 39, and one of the lamps 36 and 37 is selectively set at a fixing position facing the recording paper 16.

A discharge roller pair 40 is disposed downstream of the fixing device 35, and nips a print cut in a sheet shape and discharges the print from a discharge port. Although illustration is omitted,
A guide plate is disposed between the pair of transport rollers 15 and the paper discharge port, and the guide plate forms a transport path for the recording paper 16. Of course, cutter 3
3. There is no guide plate at the platen roller 30. An irradiation opening is formed in the guide plate at the irradiation position of the fixing device 35.

FIG. 4 is a block diagram showing the electrical configuration of the color thermal printer. The operation unit 42 includes a print start key and the like, and various commands are sent to the controller 43.
Send to The controller 43 includes a shutter opening mechanism 9, drivers 44 and 45, a cutter driving unit 46, an up-down mechanism 32, a print control unit 48, and a lamp control unit 4.
9. Control the roller shift mechanisms 14a, 23, 40a.

The controller 43 sends a rotation direction signal and a driving pulse to the driver 44. This driver 44
By rotating the pulse motor 52 forward or reverse, the feed roller pair 1
4. The capstan rollers of the transport roller pair 15 and the paper discharge roller pair 40 are rotated forward or backward. The counter 53 starts counting when the tip detection signal of the tip sensor 34 is input, and counts up when the pulse motor 52 rotates forward and counts down when it rotates reversely.
The driver 45 controls the rotation of the motor 39 to rotate the lamp house 38.

The cutter driving section 46 moves the movable blade of the cutter 33 up and down, cuts from the planned cutting line, and separates the printed portion into sheets. Up-down mechanism 3
Reference numeral 2 denotes a motor and a cam. At the pressing position, the platen roller 30 is raised to press the recording paper 16 against the heating element array 31a of the thermal head 31. In the retracted position, the platen roller 30 is lowered to a position where the recording paper 16 is separated from the heating element array 31a. The print control unit 48 includes a memory storing one frame of three-color image data and a head driver, and drives each heating element of the thermal head 31 according to the image data of each color. These heating elements generate heat in accordance with the image data and the color to be recorded, and cause the recording paper 16 to develop a desired density.

The lamp controller 49 controls light emission of the yellow fixing lamp 36 and the magenta fixing lamp 37.
The roller shift mechanisms 14a, 23, and 40a are constituted by solenoids and the like, and include a paper feed roller pair 14, a transport roller pair 15,
Each nip roller of the discharge roller pair 40 is moved.

The illuminance sensor 55 measures the illuminance of the yellow or magenta fixing lamps 36 and 37 set at the fixing position. This illuminance signal is sent to the controller 43. The controller 43 determines the pulse rate of the pulse motor 52 based on the illuminance signal, and rotates the pulse motor 52 via the driver 44 based on the pulse rate. For this reason, the relationship between the illuminance signal and the pulse rate is
The values are obtained in advance for each of 6, 37, and are stored in the look-up table memory 56. Although the relationship between the illuminance signal and the pulse rate is stored in the present embodiment,
In addition to this, any parameter may be used as long as it controls the speed, and is not limited to the pulse rate.

FIG. 5A shows an example of a change in the illuminance of the fixing lamp. In a state where such an illuminance change has occurred, as shown in FIG. 5B, the recording paper feed speed is similarly changed in accordance with the illuminance change. As a result, as shown in FIG. 6C, a substantially constant integrated fixing light amount can be obtained even when the illuminance changes during fixing.

Next, the operation of the above embodiment will be described. As shown in FIG. 3, when replacing the recording paper roll 10, a new magazine 11 is set in the storage position. After the image data to be printed is captured, if the operation unit 42 is operated to instruct printing, the controller 43 first controls the shutter opening mechanism 9 to open the shutter 13 of the magazine 11. The leading end of the recording paper 16 is housed in the magazine 11 in a state of being nipped by the pair of paper feed rollers 14. When the shutter 13 is opened, the leading end of the recording paper 16 faces the entrances of the guide plates 24 and 25. . Next, the controller 43 rotates the pulse motor 52 via the driver 44. The pulse motor 52 rotates the paper feed roller pair 14 in addition to the transport roller pair 15, pulls out the recording paper 16 from the recording paper roll 10, and sends out the recording paper 16 to the transport roller pair 15 in the nip released state. Recording paper 16
When the tip of the sensor reaches the sensor 34, a tip detection signal from the sensor 34 is sent to the controller 43.

When the controller 43 receives the leading edge detection signal, the controller 43 sends the nip roller 2 through the roller shift mechanism 23.
1 and 22 are moved to bring the pair of transport rollers 15 into a nip state. Since the capstan roller 20 is rotated by the pulse motor 52, the capstan roller 20 conveys the recording paper 16 in the nip state. In addition, the counter 5
The counting operation of No. 3 is started, and the number of drive pulses to the pulse motor 52 is counted to measure the amount of recording paper 16 to be sent.

While the recording paper 16 is being sent out, the platen roller 30 is separated from the thermal head 31 and is conveyed to the fixing device 35 through the space therebetween. The output amount of the recording paper 16 is measured by a counter 53, and when the count value reaches a predetermined set value, the driver 44
Stops the pulse motor 52. By sending the recording paper 16, the recording area is positioned on the downstream side of the heating element array 31a.

Next, the controller 43 includes a driver 44
, The pulse motor 52 is reversed to start the first pull-back of the recording paper 16. The returned recording paper 16 is returned into the magazine 11 via the guide plates 24 and 25, and is stored in a state where the recording paper roll 10 is wound and loosened.

The counter 53 counts down while the recording paper 16 is being pulled back. From the contents of the counter 53, the position of the rear end of the recording area can be known. In the present embodiment, the end of the recording area located on the leading end side of the recording paper is set as the leading end, and the end of the recording area located on the side of the recording paper roll 10 is set as the trailing end. Will be started. When the rear end of the recording area approaches the thermal head 31, the controller 43 raises the platen roller 30 via the up-down mechanism 32 and presses the recording paper 16 against the heating element array 31 a of the thermal head 31.

When the heating element array 31a faces the rear end of the recording area, the print controller 48 drives the thermal head 31 according to the yellow image data, and records the yellow image line by line. The pull-back speed of the recording paper 16 may be the same for all three colors, but may be changed for each color for high-speed printing. In this case, since the yellow image is colored with the smallest thermal energy, the pull-back speed is set to be the fastest, and the recording speed of the cyan image is set to be the slowest.

When a yellow image is recorded in the recording area, the up / down mechanism 32 retracts the platen roller 30 downward, and releases the pressing of the recording paper 16 against the thermal head 31. Thereafter, the leading end of the recording paper 16 is
, The reverse rotation of the pulse motor 52 is stopped and the counter 53 is reset.

When the pulse motor 52 rotates forward again for the second delivery of the recording paper 16, the recording paper 16 stored in the magazine 11 in a loosened state is delivered by a predetermined amount. During the second delivery, the yellow fixing lamp 36 is turned on to emit 420 nm purple visible light,
Fix the yellow image in the recording area.

The illuminance of the yellow fixing lamp 36 is detected by an illuminance sensor 55, and this illuminance signal is
Sent to The controller 43 measures the illuminance change of the yellow fixing lamp 36 from the illuminance signal, and obtains the pulse rate at the corresponding illuminance from the look-up table memory 56 in accordance with the illuminance change. Then, a motor drive pulse is sent to the driver 44 based on the pulse rate, and the rotation of the pulse motor 52 is controlled in accordance with the change in illuminance. As a result, as shown in FIG. 5, when the illuminance decreases, the feed speed of the recording paper 16 correspondingly decreases,
The fixing time becomes longer as the illuminance decreases, and the integrated fixing light amount becomes constant.

When the end of fixing to the recording area is detected based on the count value of the counter 53, the recording paper 1
6 is stopped. Also, the fixing lamp 3 for yellow
6 goes out. Thereafter, the pulse motor 52 rotates in the reverse direction and the recording paper 16 is pulled back. After the yellow fixing lamp 36 is turned off, the motor 3 is fixed for the next magenta fixing.
The rotation of 9 rotates the lamp house 38 by 180 degrees.

The rear end of the recording area is a heating element array 31a.
As described above, the platen roller 30 rises and presses the recording paper 16 against the heating element array 31a as described above. When the heating element array 31a reaches the rear end of the recording area, the thermal head 31 according to the magenta image data is used.
Is driven to record a magenta image on the recording paper 16 line by line. In the printing of the magenta image, the thermal head 31 generates larger thermal energy than the printing of the yellow image.

After the recording of the magenta image, the recording paper 16 is fed out by a predetermined amount as described above, and during this feeding, the magenta fixing lamp 37 is turned on and the magenta image in the recording area is fixed by irradiation of 365 nm ultraviolet rays. . Also during this magenta fixing, the illuminance of the magenta fixing lamp 37 is detected by the illuminance sensor 55, and based on this, the rotation speed of the pulse motor 52 is controlled, and the integrated fixing light amount becomes constant as shown in FIG. To be. After the magenta image is fixed, the feeding of the recording paper 16 is stopped, and the recording paper is pulled back.

During the third pull-back, the thermal head 31 generates the largest thermal energy according to the cyan image data, and records the cyan image line by line in the recording area. When the recording of the cyan image is completed, a full-color image is formed in the recording area. After recording the cyan image, the platen roller 30 is moved to the thermal head 31.
Move away from Then, when the leading end of the recording paper 16 is detected by the sensor 34, the reverse rotation of the pulse motor 52 is stopped and the third rotation is stopped.
The second retraction is completed, and at the same time, the counter 53 is reset.

Next, the pulse motor 52 rotates forward to feed the recording paper 16. Also at this time, the counter 53 counts the driving pulses and checks the position of the planned cutting line. When the scheduled cutting line comes to the position of the cutter 33, the pulse motor 52 temporarily stops. Next, the cutter driving section 46 operates the cutter 33 to cut the recording paper 16 at the scheduled cutting line, and cuts the recording paper 16 into sheet-like prints.
The magenta fixing lamp also emits light when the recording paper 16 is sent and discharged, and the unrecorded portion is bleached. After the bleaching is completed, the magenta fixing lamp 36 is turned off, and the lamp house 38 is rotated 180 degrees by the rotation of the motor 39 for the next yellow fixing.

The cut end of the print reaches the pair of discharge rollers 40 at the time of cutting. After the sheet is cut, the nip roller moves and the paper discharge roller pair 40 enters a nip state. Then, only the discharge roller pair 40 rotates,
The sheet-shaped print is discharged from a discharge port to a tray or the like.
The new leading end of the recording paper 16 is stopped at the cutting position.

When printing is again instructed by the operation unit 42, the conveying roller pair 15 sends out the leading end of the recording paper 16. While the recording paper 16 is being sent out, the platen roller 30 is separated from the thermal head 31 and is conveyed toward the fixing device 35 through the space therebetween. The output amount of the recording paper 16 is continuously measured by the counter 53, and when the content matches the set value, the driver 44 stops the pulse motor 52. As a result, the recording paper 16 is sent out until the rear end of the recording area is located on the downstream side of the heating element array.

Next, the controller 43 includes a driver 44
, The pulse motor 52 is reversed to start the first pull-back of the recording paper 16. Thereafter, the full-color image is recorded by pulling back three times by the above-described procedure, and finally, the sheet is cut off and discharged.

In the above-described embodiment, the fixing is performed when the recording paper is sent out. Alternatively, as shown in FIG. 6, the fixing may be performed when the recording paper is pulled back. In this case, the illuminance of the fixing lamps 36 and 37 is measured by the illuminance sensor 55 at the time of feeding, and the rotation speed of the pulse motor 52 is controlled based on the illuminance, as in the above-described embodiment. By changing the feed speed of No. 15, the variable speed fixing is performed. In the case of pulling back, the thermal head 31
, The variable speed fixing based on the change in illuminance as in the case of sending out cannot be performed, so that the feeding is performed at a constant speed. Therefore, in order to reduce the influence of the change in the illuminance at the time of constant speed feeding, most of the necessary integrated fixing light amount, for example, 70%
About 30% of the remaining 30
% Should be covered by this constant speed fixing.

Incidentally, at the time of pulling back, variable speed fixing may be performed in the same manner as sending out. In this case,
As shown in FIG. 7, the heating element 31a of the thermal head 31
The length L1 between the recording area and the irradiation area of the fixing unit 35 is set longer than the length LPA of the recording area, and after the thermal recording is completed, the feed of the color thermal recording paper 16 is continued to fix the recording area. The light is sent to the fixing beam irradiation area of the lamp 36 to perform fixing. At the time of this fixing, the illuminance of the fixing lamp 36 is measured by the illuminance sensor 55, and the feeding speed of the color thermosensitive recording paper 16 is changed in accordance with the change in the illuminance so that the integrated fixing light amount becomes constant. .

Although the unrecorded portion of the color thermosensitive recording paper 16 is light yellow, it is bleached when irradiated with ultraviolet rays from a magenta fixing lamp. In the case of fixing a yellow image, if the irradiation amount of the fixing light beam is too large, overfixing occurs,
It is necessary to pay attention to over-fixing because the color-developing characteristics of magenta deteriorate. However, since the cyan thermosensitive coloring layer is not provided with the light fixing property, the problem of overfixing does not occur in the magenta image. Therefore, the magenta fixing lamp may be kept on from the recording of the magenta image to the completion of paper discharge. Further, in magenta fixing, unlike yellow fixing, there is no problem of over-fixing as described above.
It may be set so that the integrated fixing light amount at the time of magenta fixing is excessively fixed.

In the case where the width of the irradiation area of the fixing unit 35 (length in the recording paper feed direction) is large, the leading and trailing ends of the recording area stop without passing through the fixing light beam irradiation area. When fixing unevenness occurs in this portion, as shown in FIG. 8, a shutter 70 that moves to the fixing light beam irradiation area in the recording paper feed direction at the same speed as the recording paper feed speed to open and close the irradiation area. May be provided. This allows the shutter 70 to be opened and closed at the same speed as the feed speed of the recording paper 16 immediately before the start of feeding of the recording paper 16 or immediately after the stop of the feeding, and is similar to the case where the recording paper passes through the fixing light beam irradiation area. The integrated fixing light amount can be set, and the integrated fixing light amount distribution in the fixing area becomes uniform. In FIG. 8, the same components as those shown in FIG. 3 are denoted by the same reference numerals. Further, in addition to preventing the fixing unevenness due to the stop of the recording area in the irradiation area by the shutter 70, the portion where the uneven fixing occurs may not be used for the recording. Further, when the margin becomes large, this portion may be cut off by a cutter.

In the above embodiment, the recording paper roll 1
However, the present invention may be applied to a case where the recording paper is reciprocated by a pair of conveying rollers using a cut sheet type recording paper to perform the same thermal recording.

In place of the platen roller 30, a fixed plastic template may be used. When the recording paper roll 10 is used and the recording paper 16 is pulled back, the recording paper roll 10 is simply wound and loosened. In addition, the recording paper 16 is stored in a loop by a loop forming unit (not shown). You may. In addition to winding and loosening, the recording paper may be wound around a recording paper roll 10. Further, the paper feed roller pair 14, the transport roller pair 15, and the paper discharge roller pair 40 may be always in a nip state and fed at the same feed speed in the same direction as the transport roller pair 15. Further, the positions of the cutter 33, the fixing device 35, and the like may be appropriately changed.

[0054]

According to the first or sixth aspect of the invention, the feeding direction of the color thermosensitive recording paper is made different between the time of thermal recording and the time of fixing, and the illuminance of the fixing lamp is detected at the time of fixing. The feed speed of the color thermosensitive recording paper was changed in response to the change, and the integrated fixing light amount was kept constant.Therefore, even if the illuminance of the fixing lamp changed, the occurrence of color unevenness due to this change in illuminance would not occur. Can be suppressed.

According to the second or seventh aspect of the present invention, fixing is performed during return of the color thermal recording paper after thermal recording and during feeding of the color thermal recording paper in thermal recording of the next color. For fixing during the return after the thermal recording, the illuminance of the fixing lamp is detected, and the feeding speed of the color thermosensitive recording paper is changed in accordance with the illuminance change so that the integrated fixing light amount becomes constant. Is fixed by feeding the color thermosensitive recording paper at a constant speed, so that even if the illuminance changes, the occurrence of color unevenness can be suppressed. The feed speed at the time of fixing can be increased by an amount corresponding to the increase in the light amount, and the print processing time can be shortened as a whole.

According to the third or eighth aspect of the present invention, the variable speed fixing during the feeding after the thermal recording, which is performed separately from the thermal recording, covers most of the necessary integrated fixing light amount. Since the remaining amount of the necessary integrated fixing light is covered by fixing, the color unevenness based on the decrease in illuminance does not occur in the variable speed fixing, but only occurs in the constant speed fixing where the ratio of the integrated fixing light amount is small. As a result, the degree of fixing unevenness can be reduced, and color unevenness due to a decrease in illuminance can be made inconspicuous.

According to the fourth aspect of the present invention, when the second color component image is fixed, the feed speed of the heat-sensitive recording paper is set so that overfixing is performed, and the amount of fixing light is insufficient due to a decrease in illuminance of the fixing lamp. Since no portion is generated, it is possible to eliminate color unevenness due to insufficient fixing due to a decrease in illuminance.

According to the fifth aspect of the present invention, the length between the heating element of the thermal head and the irradiation area of the fixing lamp is set to be longer than the length of the recording area. The thermal recording paper continues to be fed and the recording area is sent to the fixing beam irradiation area of the fixing lamp to perform fixing.
At the time of this fixing, the illuminance of the fixing lamp is detected, and the feeding speed of the color thermosensitive recording paper is changed in accordance with the change in the illuminance so that the integrated fixing light amount becomes constant. Can be eliminated.

[Brief description of the drawings]

FIG. 1 is a flowchart showing the outline of variable speed fixing in the color thermal recording method of the present invention.

FIG. 2 is a flowchart showing a processing procedure in the color thermal printer of the present invention.

FIG. 3 is a schematic view showing a color thermal printer.

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

5A is a diagram illustrating an example of a change in illuminance of a fixing lamp, FIG. 5B is a diagram illustrating an example of a feed speed with respect to the change in illuminance, and FIG. FIG. 3 is a diagram illustrating an example of a fixing light amount.

FIG. 6 is a flowchart illustrating a processing procedure in another embodiment in which fixing is performed even when the recording paper is pulled back.

FIG. 7 is a schematic diagram showing another embodiment in which variable speed fixing is performed when pulling back a recording sheet.

FIG. 8 is a schematic diagram showing another embodiment in which a shutter is provided between a fixing device and a recording sheet.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 recording paper roll 11 magazine 14 paper feed roller pair 15 transport roller pair 16 color thermal recording paper 20 capstan roller 21, 22 nip roller 31 thermal head 35 fixing device 36 yellow fixing lamp 37 magenta fixing lamp 40 discharge roller 55 illuminance Sensor 70 Shutter

Claims (8)

[Claims] 1. A first to third thermosensitive coloring layers having different coloring colors are sequentially provided on a support, and at least the uppermost third thermosensitive coloring layer and the second thermosensitive coloring layer are formed on the support. Using a color thermosensitive recording paper that has a fixing property with light rays of a specific wavelength range and the thermal recording sensitivity is lower at the deeper layer, each thermal coloring layer is sequentially thermal-recorded with a thermal head, and the thermal recording is performed using this thermal recording. At least a third color component image by a fixing lamp that irradiates light rays in a wavelength range specific to the layer,
In a color thermal recording method for sequentially fixing a second color component image to record a full-color image, the feeding direction of the color thermal recording paper is made different between thermal recording and fixing, and the illuminance of a fixing lamp is detected during fixing. A color thermal recording method characterized in that the feeding speed of the color thermal recording paper is changed in accordance with the change in illuminance so that the integrated fixing light amount becomes constant. 2. A thermosensitive coloring layer comprising first to third thermosensitive coloring layers having different colors to be formed is sequentially formed on a support, and at least the uppermost third thermosensitive coloring layer and the second thermosensitive coloring layer are formed on the support. Using a color thermosensitive recording paper that has a fixing property with light rays of a specific wavelength range and the thermal recording sensitivity is lower at the deeper layer, each thermal coloring layer is sequentially thermal-recorded with a thermal head, and the thermal recording is performed using this thermal recording. At least a third color component image by a fixing lamp that irradiates light rays in a wavelength range specific to the layer,
A color thermal recording method for sequentially fixing a second color component image to record a full-color image, comprising: returning a color thermal recording sheet after thermal recording; and feeding a color thermal recording sheet in the next color thermal recording. The fixing during return after the thermal recording detects the illuminance of the fixing lamp, and changes the feed speed of the color thermosensitive recording paper in accordance with the change in the illuminance so that the integrated fixing light amount becomes constant. Wherein the fixing in the thermal recording is performed by feeding the color thermal recording paper at a constant speed. 3. The method according to claim 1, wherein the fixing during the return after the thermal recording covers most of the necessary integrated fixing light quantity, and the fixing during the feeding of the thermal recording covers the rest of the necessary integrated fixing light quantity. Item 4. A color thermal recording method according to Item 2. 4. The fixing device according to claim 1, wherein the fixing of the second color component image is performed so that overfixing is performed so that a portion of insufficient fixing light amount due to a decrease in illuminance of a fixing lamp does not occur. Item 4. A color thermosensitive recording method according to any one of Items 1 to 3. 5. A first to third thermosensitive coloring layers having different coloring colors are sequentially provided on a support, and at least the uppermost third thermosensitive coloring layer and the second thermosensitive coloring layer are formed on the support. Using a color thermosensitive recording paper that has a fixing property with light rays of a specific wavelength range and the thermal recording sensitivity is lower at the deeper layer, each thermal coloring layer is sequentially thermal-recorded with a thermal head, and the thermal recording is performed using this thermal recording. At least a third color component image by a fixing lamp that irradiates light rays in a wavelength range specific to the layer,
In a color thermal recording method of sequentially fixing a second color component image to record a full color image, a length between a heating element of the thermal head and an irradiation area of a fixing lamp is set to be longer than a length of a recording area. After the completion of the thermal recording, the color thermosensitive recording paper is continuously fed and the recording area is fed to the fixing light beam irradiating area of the fixing lamp to perform fixing.At the time of this fixing, the illuminance of the fixing lamp is detected. A color thermosensitive recording method, characterized in that the feeding speed of the color thermosensitive recording paper is changed in accordance with the change in illuminance so that the integrated fixing light amount becomes constant. 6. A conveying roller pair for nipping and sending and pulling back the color thermosensitive recording paper alternately, and a color thermosensitive recording paper arranged downstream of the conveying roller pair in the feeding direction at the time of the first pullback. A thermal head that records a yellow image in the recording area of the above, records a magenta image at the time of the second retraction, and records a cyan image at the time of the third retraction, and is disposed on the downstream side in the sending direction of the thermal head. At the time of the second delivery after the first retraction, the color thermosensitive recording paper passing through the fixing light beam irradiation area is irradiated with light of the first wavelength range to fix a yellow image, and after the second retraction. Third
A fixing device for fixing a magenta image by irradiating a light beam of a second wavelength range at the time of the second transmission, a sensor for measuring the illuminance of a fixing lamp during fixing, and a color thermosensitive recording paper based on the illuminance change of the sensor. A color thermal printer comprising: a feed speed control unit that changes a feed speed so that an integrated fixing light amount becomes constant. 7. A yellow image is fixed by a fixing device in the second pullback, and a magenta image is fixed by a fixing device in the third pullback. The fixing is performed by feeding a color thermosensitive recording paper at a constant speed. 7. The color thermal printer according to claim 6, wherein the thermal printing is performed. 8. The variable-speed fixing performed by changing the feed speed of the color thermosensitive recording paper covers most of the required integrated fixing light amount, and the necessary integration is performed by constant-speed fixing performed by feeding the color thermosensitive recording paper at a constant speed. 8. The color thermal printer according to claim 7, wherein the remaining amount of fixing light is covered.