JPH0872270A - Color thermal printer - Google Patents

Abstract

PURPOSE: To eliminate the increase in the margin of a color thermal printer of a reciprocating time by increasing an integrated fixing light quantity near the end of a color thermal recording material by decelerating the material before the feeding of the end of the material by conveying roller pair at the time of optical fixing. CONSTITUTION: When a rear end sensor detects the rear end of a recording material 12, the feeding speed of the material 12 is decelerated from a constant- speed feeding speed to 2/3 of the decelerated speed. The integrated fixing light quantity at the point P1 of the material of the rear end of a fixing area Al is '0' at this time point. At a point P2 of the same end, the light quantity is maximum by the deceleration. When the material 12 reaches this position B, a shutter plate 41 starts to move, thereby starting to close the plate 41. The closing speed of the plate is three times as large as the feeding speed when the decelerating speed of the material is 13.3mm/sec. Thus, at one second after the start to close the plate 41 of C, the area A1 is completely covered to cut the ultraviolet ray of an ultraviolet lamp, the feeding of the material 12 is stopped, and then the lamp during optically fixing is deenergized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating type color thermal printer, and more particularly to a color thermal printer which performs optical fixing to near the end of a color thermal recording material.

[0002]

2. Description of the Related Art At least three types of thermosensitive coloring layers such as a cyan thermosensitive coloring layer, a magenta thermosensitive coloring layer, and
A color thermal printer is known which prints a full-color image by using a color thermal recording material in which a yellow thermosensitive coloring layer is layered in order. In this color thermal printer,
At the time of printing, the thermal head is pressed against the color thermosensitive recording material, a yellow image is thermally recorded line by line on the yellow thermosensitive coloring layer having the highest thermal sensitivity, and immediately after that, the yellow thermosensitive coloring layer is optically fixed. Next, a magenta image is thermally recorded on the magenta thermosensitive coloring layer, and then the magenta image is optically fixed. Finally, a cyan image is thermally recorded on the cyan thermosensitive coloring layer to obtain a full-color image.

Such thermal recording and optical fixing are performed while the color thermal recording material is relatively moved with respect to the thermal head and the optical fixing device. With this moving system, the color thermal printer is mainly a platen drum system. And reciprocating method. In the platen drum system, the color thermosensitive recording material is wound around a platen drum having a peripheral length corresponding to the length of the color thermosensitive recording material and rotated, and the color thermosensitive recording material is fixed to the platen drum. The tip of the color thermosensitive recording material is clamped by a clamper. With this method,
In order to wind the color thermosensitive recording material, a platen drum having a peripheral length corresponding to the length of the recording material is required. Therefore, the platen drum method is suitable for printing about the size of postcards, and for printing of B5, A4 size or the like larger than that, a platen drum having a large diameter is required to correspond to this, and downsizing of the apparatus becomes difficult. Moreover, since the diameter increases, the friction load radius also increases,
Therefore, it is necessary to use a powerful drive motor. On the other hand, the color thermosensitive recording material is only slightly clamped at the tip, so that the recording surface can be effectively used in this platen drum system.

On the other hand, as shown in FIG. 8, in the reciprocating type color thermal printer, the leading end of the color thermal recording material 3 is nipped by a conveying roller pair 2 consisting of an upper nip roller 2a and a lower driving roller 2b. The platen roller 7 having a small diameter and the thermal head are alternately transported in the forward direction of transporting from the paper feed tray 4 side to the paper discharge passage 5 and in the reverse direction of transport from the paper discharge passage 5 side to the paper feed tray 4 side. 8 and the color thermosensitive recording material 3 is sandwiched between them, and yellow, magenta,
The three colors of cyan are sequentially recorded by heat.

Further, on the downstream side of the conveying roller pair 2 in the forward direction, an optical fixing device 9 including a yellow ultraviolet lamp 9a and a magenta ultraviolet lamp 9b and a lamp house 9c covering these lamps 9a and 9b is provided. The thermal recording layers are arranged so as to carry out thermal recording on each thermosensitive coloring layer while carrying them in the forward direction, and the optical fixing device 9 is turned on to carry out the optical fixing when carrying the paper in the forward or reverse direction. In this method, it is not necessary to use a platen drum having a peripheral length corresponding to the length of the heat-sensitive recording material 3, and a platen roller 7 having a small diameter can be used, which is advantageous for downsizing of the apparatus and small. A drive motor can be used.

[0006]

However, in the reciprocating color thermal printer, in order to prevent the displacement of the three color pixels, the thermal recording is always performed on the transport roller pair 2 in the transport system having a simple structure. It is necessary to hold the material 3 in between. Therefore, a holding margin L1 to be held between the pair of transport rollers 2 is required. This portion does not reach the optical fixing device and cannot be fixed.

Further, as shown in FIG. 8, it is necessary to arrange two kinds of ultraviolet lamps 9a and 9b side by side, so that in the lamp 9b on the side distant from the conveying roller pair 2, the area of insufficient fixing becomes wide. Further, when the end portion of the recording material 3 is positioned on the conveying roller pair 2 and the feeding of the recording material 3 is stopped, the ultraviolet irradiation area (fixing area) A1 is irradiated at the portion that has reached first and the portion that has reached afterwards. The amount of light is different, and the amount of optical fixing is uneven in this area A1. This allows
There is a problem that the portion that reaches the fixing area A1 later becomes insufficient in optical fixing.

Therefore, in the reciprocating type color thermal printer, the image quality is deteriorated due to insufficient optical fixing in the fixing area A1. If you want uniform quality on the printed screen,
It is necessary to make L2 including the length L4 of the area A1 and the above-mentioned L1 into a margin portion (length L3). in this way,
The reciprocating method requires a large margin length L3, which causes a problem that a printable portion becomes narrow. In particular, when the fixing light amount is increased by using a plurality of lamps and the conveyance speed during fixing is increased to shorten the printing time, the fixing area A1 is further expanded, and thus the margin length is further increased. There is a problem that it gets bigger.

In order to eliminate the insufficient fixing portion in the fixing area A1, it is necessary to give a sufficient amount of fixing light to this portion. As a method of additionally providing the fixing light amount, it is conceivable to turn on the ultraviolet lamp for a certain period of time even after the feeding of the recording material is stopped.
Since it is necessary to turn on the lamp for a certain period of time after stopping the feeding of the recording material, there is a problem that the fixing time becomes long.

The present invention is to solve the above-mentioned problems.
An object of the present invention is to provide a color thermal printer in which the margin of the reciprocating color thermal printer does not become long. Another object of the present invention is to provide a color thermal printer capable of shortening the printing time.

[0011]

In order to solve the above problems, in the color thermal printer according to claim 1, the end of the color thermal recording material approaches the conveying roller pair at the time of optical fixing to feed the same. Before stopping, the feeding of the color thermosensitive recording material is decelerated, and this deceleration increases the integrated fixing light amount near the edge of the color thermosensitive recording material.

Further, in the color thermal printer according to the second aspect of the invention, a shutter for moving to the optical fixing device in the same direction as the feeding direction of the color thermal recording material at the time of optical fixing to cover the optical fixing device and shield the fixing light is provided. Before the end of the color thermosensitive recording material comes close to the conveying roller pair and stops its feeding at the time of optical fixing, the feeding of the color thermosensitive recording material is decelerated, and the increase in the fixing light amount due to this deceleration is cut by the shutter. In this way, the integrated fixing light amount is made almost constant.

[0013]

The feeding of the color thermosensitive recording material is decelerated before the end portion of the color thermosensitive recording material is positioned on the pair of conveying rollers and the feeding thereof is stopped during optical fixing. As a result, the recording material moves slowly in the fixing area as compared with the feeding before deceleration, and the integrated fixing light amount increases. Therefore, the insufficient amount of fixing light is reduced, and the recording area is expanded by this amount. In addition, the shutter starts to be closed when a certain time has elapsed after the deceleration. The closing speed of the shutter is set faster than the feeding speed of the color thermosensitive recording material,
As a result, the excess amount of fixing light is cut, and the integrated amount of fixing light is made substantially constant.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 showing the outline of a color thermal printer, a color thermal recording material 12 sent from a paper feed tray 11 by a paper feed roller 10 passes through a paper feed passage 13 toward a first conveying roller pair 14. Be transported. The first conveying roller pair 14 sandwiches the color thermosensitive recording material 12 between the upper nip roller 15 and the lower driving roller 16 and sends it between the platen roller 17 and the thermal head 18.

The thermal head 18 has a large number of heating elements 1.
8a are arranged in a line in the width direction of the recording material 12, and each heating element 18a generates heat energy according to the color to be recorded and the density of the pixel. Thermal head 18
Is rotatably mounted on the mounting shaft 20, and is rotated clockwise about the mounting shaft 20 to generate the heat generating element 18a.
And the color recording material 12 between the platen roller 17 and the platen roller 17.
Sandwich.

The color thermosensitive recording material 12 passes between the thermal head 18 and the platen roller 17 and is conveyed toward the second conveying roller pair 22. The second conveying roller pair 22 is composed of a nip roller 23 arranged above and a driving roller 24 arranged below, and the color thermosensitive recording material 12 is sandwiched between them. The heating element 18a generates heat energy corresponding to, for example, a yellow image in synchronism with the feeding of the second conveying roller pair 22, whereby the yellow image is thermally recorded on the color thermosensitive recording material 12.
The rotation of the drive roller 16 of the first transport roller pair 14, the drive roller 24 of the second transport roller pair 22, and the paper feed roller 10 is controlled by a transport motor 56. The transport motor 56 is rotationally controlled by the controller 40 described later via the driver 57. Further, the paper feed roller 10 is provided with an electromagnetic clutch (not shown), and after the rotation of the paper feed roller 10 pulls out the color thermosensitive recording material 12 from the tray 11 and nips it to the first conveying roller pair 14, The electromagnetic clutch is activated so that the rotation of the carry motor 56 is not transmitted to the paper feed roller 10.

As shown in FIG. 2, the color thermosensitive recording material 12 has a cyan thermosensitive coloring layer 26, a magenta thermosensitive coloring layer 27, a yellow thermosensitive coloring layer 28, and a protective layer 29 which are sequentially formed on a support 25. ing. Each of these thermosensitive coloring layers 26
Nos. To 28 are layered from the surface in the order of thermal recording. For example, when thermal recording is performed in the order of magenta, yellow, and cyan, the positions of the yellow thermosensitive coloring layer 28 and the magenta thermosensitive coloring layer 27 are Can be replaced. The support 25
For opaque coated paper or plastic film, and when making OHP sheets,
A transparent plastic film is used.

The cyan thermosensitive coloring layer 26 contains an electron-donating dye precursor and an electron-accepting compound as main components, and develops a cyan color when heated. Magenta thermosensitive coloring layer 2
No. 7 contains a diazonium salt compound having a maximum absorption wavelength of about 365 nm, and a coupler which thermally reacts with this compound to develop magenta color. When the magenta thermosensitive coloring layer 27 is irradiated with ultraviolet rays in the vicinity of 365 nm after thermal recording, the diazonium salt compound is photodecomposed and the coloring ability is lost. The yellow thermosensitive coloring layer 28 has a maximum absorption wavelength of about 42.
It contains a diazonium salt compound having a thickness of 0 nm and a coupler which thermally reacts with the compound to develop a yellow color. When the yellow thermosensitive coloring layer 28 is irradiated with ultraviolet rays in the vicinity of 420 nm, the yellow thermosensitive coloring layer 28 is optically fixed and loses its coloring ability.

As shown in FIG. 1, the second conveying roller pair 22
A reversing frame 35 is rotatably attached to a machine frame (not shown) via a mounting shaft 36 on the downstream side of the forward feed (feeding to the right in FIG. 1). Optical fixing devices 30 and 31 are attached to the reversing frame 35 at point-symmetrical positions around the mounting shaft 36. The fixing devices 35 and 31 are fixed by rotating the reversing frame 35 by 180 °. It is designed to be alternately set to the position. The reversing frame 35 is rotated by a reversing motor 38, and the rotation of the reversing motor 38 is controlled by a controller 40 via a driver 39.

The reversing frame 35 is arranged so that the optical fixing devices 30 and 31 at the fixing position are close to the nip roller 23, and the length L3 of the margin portion shown in FIG. 8 is reduced. . The first optical fixing device 30 is composed of two yellow ultraviolet lamps 30 a and a lamp house 32. The lamp house 32 reflects the ultraviolet rays emitted from the ultraviolet lamp 30a and irradiates the color thermosensitive recording material 12 with the ultraviolet rays. Similarly, the second optical fixing device 31 includes two magenta ultraviolet lamps 31 a and a lamp house 3.
And 4. UV lamp 30 for yellow
a emits ultraviolet rays having an emission peak of approximately 420 nm to optically fix the yellow thermosensitive coloring layer 28, and the magenta ultraviolet lamp 31a emits ultraviolet rays having an emission peak of approximately 365 nm to optically fix the magenta thermosensitive coloring layer 27. To do.

A shutter plate 41 is arranged between the optical fixing devices 30 and 31 at the fixing position and the recording material 12. The shutter plate 41 moves in the same direction as the feeding direction of the recording material at the time of fixing from the retracted position shown in FIG. 3, and as shown in FIG. 4, the fixing area A1 of each optical fixing device 30, 31 at the fixing position. Cover. When the shutter plate 41 covers the entire fixing area A1, the movement of the shutter plate 41 is stopped.

As shown in FIG. 3, the shutter plate 41 is rotatably attached to the attachment shaft 36 of the reversing frame 35 via the attachment plate 42, and is curved in an arc shape having the same curvature as the movement locus thereof. There is. As described above, the shutter plate 41 is formed by being curved, and the shutter plate 41 is rotatably attached to the attachment shaft 36 via the attachment plate 42. Therefore, even if the optical fixing devices 30 and 31 are brought close to the nip roller 23, the shutter plate 41 is provided. Can be moved, and the margin portion can be reduced.

The shutter plate 41 is biased clockwise by a coil spring 43. A rotary gear 44 is fixed to the mounting plate 42, and a shutter motor 45 is linked to the rotary gear 44. As shown in FIG. 1, the rotation of the shutter motor 45 is controlled by the controller 40 via the driver 46. Then, the shutter motor 4
When the switch 5 is turned on, the rotary gear 44 rotates counterclockwise, and as shown in FIG.
Move to cover. In addition, the shutter motor 45
The shutter motor 4 is an electromagnetic clutch (not shown) that is set to FF.
When the connection between the gear 5 and the rotary gear 44 is broken, the shutter plate 41 is returned from the closed position to the retracted position by the bias of the coil spring 43, as shown in FIG. Instead of using such a shutter motor 45, a solenoid may be used to open and close the shutter.

As shown in FIG. 1, a trailing edge sensor 51 for detecting the trailing edge of the recording material 12 is provided between the thermal head 18 and the second conveying roller pair 22. The rear end sensor 51 is composed of a projector 51a and a light receiver 51b, and a detection signal from the light receiver 51b is sent to the controller 40.
Sent to

The controller 40 is composed of a well-known microcomputer. In addition to the sequence control of each part of the color thermal printer, the controller 40 controls the feeding of the recording material 12 based on the trailing edge detection signal from the trailing edge sensor 51 and the shutter. The closing control of the plate 41 is performed.

FIG. 5 is an explanatory view showing the feeding position of the color thermosensitive recording material 12 and the cumulative light amount distribution at that position in the order of operation. FIG. 5A shows a color thermosensitive recording material 12
The feeding position of the recording material just before decelerating the feeding of
The integrated light amount distribution at that position is shown. In the present embodiment, when the trailing edge sensor 51 detects the trailing edge of the recording material 12, the feeding speed of the recording material 12 is reduced from the constant feeding speed (for example, 20 mm / sec) to a deceleration feeding speed (2/3) thereof. 13.3 mm / sec). At the time of FIG. 5 (A),
Up to the point P0 of the recording material located at the tip of the fixing area A1, the cumulative fixing light amount C1 is set at a constant feed rate of 20 mm / sec.
Has been obtained. Further, the integrated fixing light amount at the point P1 of the recording material located at the rear end of the fixing area A1 is "0" at this point.

FIG. 5B shows the position of the recording material 12 when the recording material 12 is fed for 2 seconds and advanced 26.6 mm by the decelerating feed of the recording material 12 and the integrated fixing light amount at this position. Shows. At the point P2 of the recording material located at the leading end of the fixing area A1, the accumulated fixing light amount shows the maximum due to the decelerated feeding. When the recording material 12 reaches the position shown in (B), the shutter plate 41 starts moving to close the shutter plate 41.

The closing speed of the shutter plate is 3 times the feeding speed when the deceleration speed of the recording material is 13.3 mm / sec.
It is doubled to 40 mm / sec. As a result, FIG.
As shown in (C), the shutter plate 41 starts to close and
After a lapse of seconds, the shutter plate 41 completely covers the fixing area A1 and cuts off the ultraviolet rays from the ultraviolet lamp 30a. Further, when the shutter plate 41 completely covers the recording area A1 and is in a closed state, the feeding of the recording material 12 is stopped, and then the ultraviolet lamp 30a during the optical fixing is turned off. Therefore, after one second elapses from the state of FIG. 5B, the point P3 of the recording material advances by 13.3 mm, and the integrated fixing light amount in this state is the point P1 of the recording material.
Indicates the maximum value, and this integrated fixing light amount is 1.5 times the integrated fixing light amount C1 in constant speed feeding.

The cut amount of the integrated fixing light amount due to the closing operation of the shutter plate 41 is shown by hatching H1 in FIG. Therefore, this cut is excluded from the integrated fixing light amount. Further, since the shutter plate 41 enters the fixing area A1, the rear end side of the point P3 is completely shielded from light, and the integrated fixing light amount is "0". As described above, by reducing the feeding speed of the recording material 12, the integrated fixing light amount increases, and the fixing area A1 shows the same integrated fixing light amount as in FIG. Although there is a distribution and the amount of fixing light is insufficient in the fixing area A1, as shown in FIG. 5C, this insufficient amount of fixing light can be reduced by L5. Therefore, the length of this L5 becomes the recordable area PA, and the blank space can be reduced.

Next, the operation of the above embodiment will be described.
As shown in FIG. 1, when the print start switch is operated, the carry motor 56 rotates to rotate the paper feed roller 10. As a result, the color thermosensitive recording material 12 on the uppermost part of the tray 11 is sent out, and is conveyed toward the first conveying roller pair 14 through the sheet feeding passage 13. When the front end of the color thermosensitive recording material 12 is fed between the nip roller 15 and the driving roller 16 of the first conveying roller pair 14, the color thermosensitive recording material 12 is sandwiched between these and directed toward the thermal head 18. To transport. After the nip of the color thermosensitive recording material 12 of the first conveying roller pair 14, the rotation of the paper feeding roller 10 is made free.

Thermal head 18 and platen roller 17
The color thermosensitive recording material 12 that has passed through the space between and is conveyed toward the second conveying roller pair 22. Second transport roller pair 2
2 sandwiches the color thermosensitive recording material 12 between the nip roller 23 and the driving roller 24. At the same time, the thermal head 18 rotates clockwise around the mounting shaft 20,
The heating element 18a presses the color thermosensitive recording material 12 on the platen roller 17. Then, the first conveying roller pair 14
The sandwiching of the color thermosensitive recording material 12 is released.

In this state, the color thermosensitive recording material 12 is conveyed in the forward direction by the second conveying roller pair 22, and when the leading end of the recording area of the color thermosensitive recording material 12 reaches the heat generating element 18a during the conveyance, each heat is generated. The element 18a generates heat energy corresponding to the pixel to generate the yellow thermosensitive coloring layer 28.
The yellow image is thermally recorded line by line. When recording one pixel, each heating element 18a supplies bias thermal energy for bringing the yellow thermosensitive coloring layer 28 into a state immediately before coloring, and gradation expression thermal energy corresponding to the coloring density, in the color thermosensitive recording material 12. Give to. Further, the ultraviolet lamp 30a of the yellow light fixing device 30 is turned on in synchronization with the yellow thermal recording. With this UV lamp 30a, almost 420
The near-ultraviolet light having a wavelength of about nm is applied to the color thermosensitive recording material 12 to fix the magenta thermosensitive coloring layer 27 so that yellow color does not develop during thermal recording.

As shown in FIG. 1, color thermosensitive recording material 1
When thermal recording and fixing of the yellow image are performed up to near the rear end of the forward direction 2 and the rear end of the color thermal recording material 12 is detected by the rear end sensor 51, as shown in FIG. The feed speed of the color thermosensitive recording material 12 is reduced to 2/3,
It becomes 13.3 mm / sec. Due to this deceleration, the fixing area A
Within 1, the integrated fixing light amount is 1.5 at maximum compared to the constant speed feeding.
Double. Then, as shown in FIG. 5B, when the point P1 of the recording material located at the rear end of the fixing area A1 at the start of deceleration reaches 2/3 of the fixing area A1, the shutter plate 41 is closed. To start. The shutter speed is 40 mm / sec, which is almost three times the deceleration speed of the recording material.
As shown in (1), 1 second after the shutter plate 41 starts to be closed, the tip of the shutter plate 41 reaches the point P1 of the recording material 12, and the feeding of the recording material 12 is stopped at this point. Therefore, as shown in FIG. 5C, the accumulated fixing light amount in the vicinity of the end of the recording material 12 at this time is reduced by the amount of fixing light amount L5 even in the fixing area A1, and the recording is performed by this amount. The possible area PA becomes wider.

After the shutter plate 41 is completely closed,
The ultraviolet lamp 30a of the optical fixing device 30 is turned off.
Further, since the shutter motor 45 is turned off, the shutter plate 41 moves from the closed position to the original retracted position and the coil spring 4 is moved.
It is returned by the bias of 3. After that, the reversing motor 38 rotates to start reversing the reversing frame 35. And
When the reversing frame 35 rotates 180 °, the reversing motor 3
The rotation of 8 ends. As a result, the magenta optical fixing device 31 is set at the fixing position.

Next, referring to FIG. 1, the controller 40
Turns the thermal head 18 counterclockwise about the mounting shaft 20 and sets it in the upper retracted position to release the pressure on the color thermosensitive recording material 12. After that, the conveyance motor 38 is rotated in the reverse direction so that the second conveyance roller pair 22 rotates in the opposite direction, and the color thermosensitive recording material 12 is conveyed in the opposite direction.

When the forward end of the recording area of the color thermosensitive recording material 12 is conveyed to the position of the heating element 18a,
The second transport roller pair 22 is once stopped. Then, the thermal head 18 returns to the thermal recording position again, and the second transport roller pair 22 rotates forward to transport the color thermal recording material 12 in the forward direction. The thermal head 18 applies thermal energy according to a magenta image to the magenta thermosensitive coloring layer 27 to perform thermal recording. Further, the magenta ultraviolet lamp 30b is turned on during the thermal recording. This magenta UV lamp 30b irradiates the color thermosensitive recording material 12 with near-ultraviolet rays in the vicinity of 365 nm, and the next cyan thermosensitive coloring layer 2 is irradiated.
It is fixed so that magenta does not develop color during thermal recording of No. 6.

The magenta image is thermally recorded up to the trailing end of the color thermosensitive recording material 12 in the forward direction.
When the passage of the trailing edge of the recording material 12 is detected based on the signal of, the feeding of the recording material 12 is decelerated in the same manner as the thermal recording of the yellow image as shown in FIG. Further, when a certain time has elapsed after deceleration, the shutter motor 45 is turned on, and the shutter plate 41 enters the fixing area A1. Then, after the shutter plate 41 completely covers the fixing area A1, the feeding of the recording material 12 is stopped. After this stop, the magenta ultraviolet lamp 30b is turned off. Thereafter, the reversing frame 35 is rotated by 180 ° and the yellow light fixing device 30 is set at the light fixing position.

Next, the controller 40 sets the thermal head 18 to the upper retracted position, and the pressing of the color thermosensitive recording material 12 is released. Immediately after this, similarly to the case of yellow recording, the transport motor 56 is rotated in the reverse direction to rotate the first and second transport roller pairs 14 and 22 in the opposite directions.

Next, when the forward end of the recording area of the color thermosensitive recording material 12 is conveyed to the position of the heating element 18a, the thermal head 18 returns to the thermal recording position as described above. Then, the first and second conveying roller pairs 14, 2
2 rotates to convey the color thermosensitive recording material 12 in the forward direction. During this conveyance, the thermal head 28 thermally records a cyan image on the cyan thermosensitive coloring layer 26. The cyan thermosensitive coloring layer 26 is not provided with photofixability because the coloring heat energy has a value that does not produce color in a normal storage state, and the photofix device 30 does not light. Therefore, even if the rear end portion of the recording material 12 is positioned on the pair of transport rollers 22, the speed is not reduced and the closing control of the shutter plate 41 is not performed.
Further, since the yellow fixing device 30 has already been set to the fixing position in preparation for the next yellow recording, the reversing frame 35 is not reversed after the cyan thermal recording.

When thermal recording is performed on all the thermosensitive coloring layers,
The second conveying roller pair 22 continues to rotate as it is, and the color thermosensitive recording material 12 is fed into the paper discharge passage 55. The color thermosensitive recording material 12 sent to the paper discharge passage 55 is discharged to the paper discharge tray by the paper discharge rollers.

In the above embodiment, the speed is reduced to a constant speed, the predetermined amount is fed, and then stopped. However, in addition to this, the constant speed feeding speed may be continuously reduced to "0". In this case, the shutter speed is changed according to the deceleration. Thereby, the integrated fixing light amount in the fixing area A1 can be made more constant. Further, by reducing the deceleration speed, it is possible to further increase the integrated fixing light amount, and correspondingly, the increase L of the recordable area PA is increased.
4 can be made larger, and the recordable area PA can be further expanded.

Further, in the above embodiment, the shutter plate 41 is rotated about the mounting shaft 36 of the reversing frame 35 to open and close the shutter, but in addition to this, as shown in FIG. 60 slide mechanism 6
Alternatively, the slide movement may be performed simply by 1. The slide mechanism 61 can be configured by a reciprocating mechanism by a rack and pinion or a link mechanism.

Further, as shown in FIG. 7, when the shutter plate 65 slides by the slide mechanism 64 and the shutter plate 65 interferes with the nip roller 66,
The shutter plate 65 is made of a flexible plate such as plastic, and is guided by the guide member 67.
The shutter plate 65 may be retracted above the nip roller 66 when the shutter plate 65 is opened.

Further, in the above embodiment, each fixing device 30, 3
Although 1 is configured by using two ultraviolet lamps 30a and 31a, one ultraviolet lamp or three or more ultraviolet lamps may be used. When one ultraviolet lamp is used, it may be arranged side by side in one lamp holder as shown in FIG. 8, or may be arranged at point symmetric positions in the reversing frame. Further, each fixing device 30, 31 is connected to a pair of transport rollers
The length L2 of the margin portion (see FIG. 8) can be shortened by bringing the optical fixing devices 30 and 31 and the nip roller 23 of the conveying roller pair 22 closer to each other.
When the lamp holders 32 and 34 of the fixing devices 30 and 31 interfere with the nip rollers 23 when the reversing frame 35 rotates due to the proximity of the reversing frame 35, the reversing frame 35 is rotatably attached to a swing frame (not shown). The reversing frame 35 may be rotated with the swing frame being lifted upward.

In the above embodiment, as shown in FIG. 1, the paper feed tray 11 is provided on the left side of the thermal head 18, but instead of this, a paper feed tray may be provided on the right side of the thermal head 18. Good. Further, in the above embodiment, the deceleration control of the recording material and the shutter closing control are performed at the end of the magenta fixing. However, when the magenta optical fixing device 31 is used for bleaching, the deceleration control of the recording material and the shutter are performed. The closing control may be omitted. Further, although the rear end sensor 51 is provided in the above embodiment, it may be omitted.
In this case, a stepping motor is used as the carry motor 56, and the feed amount of the recording material is detected by managing the number of steps. A shutter driving control may be performed by using a stepping motor as the shutter motor 45 and managing the number of steps of the stepping motor.

[0046]

According to the present invention, the feed of the color thermosensitive recording material is decelerated before the end of the color thermosensitive recording material approaches the conveying roller pair at the time of optical fixing and the feeding is stopped. It is possible to increase the integrated fixing light amount. As a result, the insufficient amount of light in the fixing area can be reduced, and the recordable area can be expanded accordingly.

Further, the optical fixing device is provided with a shutter which moves in the same direction as the feeding direction of the color thermosensitive recording material at the time of optical fixing to cover the optical fixing device and shields the fixing light so as to adjust the deceleration of the feeding of the recording material. By cutting off the increase in the fixing light amount due to the deceleration by the shutter, the increase in the fixing light amount is suppressed and the integrated fixing light amount is made substantially uniform.

[Brief description of drawings]

FIG. 1 is a schematic view showing a main part of a color thermal printer embodying the present invention.

FIG. 2 is a schematic view showing an example of a layer structure of a color thermal recording material used in a color thermal printer.

FIG. 3 is a side view showing an open state of a shutter plate.

FIG. 4 is a side view showing a closed state of a shutter plate.

FIG. 5 is a diagram showing each feed position of a color thermosensitive recording material and an integrated light amount distribution at this feed position.

FIG. 6 is a schematic view showing a shutter plate in another embodiment.

FIG. 7 is a schematic view showing a shutter plate in another embodiment.

FIG. 8 is a schematic diagram showing a conventional example of a color thermal printer.

[Explanation of symbols]

 12 Color thermal recording material 17 Platen roller 18 Thermal head 14,22 Conveying roller pair 30,31 Optical fixing device 30a, 30b UV lamp 35 Inversion frame 40 Controller 41, 60, 61 Shutter plate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B41M 5/18 S

Claims (2)

[Claims] 1. At least first to color different colors
A color thermosensitive recording material on which a third thermosensitive coloring layer is laminated is used, and one type of thermosensitive coloring layer is selectively colored by a thermal head while reciprocating by nipping the color thermosensitive recording material with a conveying roller pair. Before the next thermosensitive coloring layer is colored, a color thermosensitive printer that records a full-color image in a frame-sequential manner by irradiating and fixing the electromagnetic radiation peculiar to the colored thermosensitive coloring layer from the optical fixing device is used. Before the end of the color thermosensitive recording material approaches the conveying roller pair and stops its feeding, the feeding of the color thermosensitive recording material is decelerated, and this deceleration increases the integrated fixing light amount near the end of the color thermosensitive recording material. A color thermal printer that is characterized by: 2. At least first to color different colors
A color thermosensitive recording material on which a third thermosensitive coloring layer is laminated is used, and one type of thermosensitive coloring layer is selectively colored by a thermal head while reciprocating by nipping the color thermosensitive recording material with a conveying roller pair. In the color thermal printer which records a full-color image in a frame sequential manner by irradiating and fixing an electromagnetic ray peculiar to the colored thermosensitive coloring layer from the optical fixing device before coloring the next thermosensitive coloring layer. The device is equipped with a shutter that moves in the same direction as the feeding direction of the color thermosensitive recording material at the time of optical fixing and covers the optical fixing device to block the fixing light, and the edge of the color thermosensitive recording material approaches the conveying roller pair during optical fixing. And before stopping the feed,
A color thermal printer characterized by decelerating the feeding of a color thermosensitive recording material and cutting the increase in the amount of fixing light due to the deceleration by a shutter to make the integrated amount of fixing light substantially constant.