JPH06262779A - Delivery apparatus of thermal printer - Google Patents

Abstract

PURPOSE:To increase the delivery speed of a thermal printer and to reduce the damage of recording paper. CONSTITUTION:A thermal head 24 comes into contact with the color thermal recording paper 10 wound around the outer periphery of a platen drum 15 under pressure to record an image on the recording paper 10. During delivery, a clamper 20 is raised to a delivery position and the thermal head 24 is separated from the color thermal recording paper 10. However, since a paper pressing member 38 presses the color thermal recording paper 10 to the platen drum when the platen drum 15 is rotated, the color thermal recording paper 10 is rotated together with the platen drum 15 and the leading end part 10a of the color thermal recording paper 10 passes under the stopped clamper 20 to enter a delivery passage 45.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper discharge device for a thermal printer, and more particularly to a paper discharge device for rotating a platen drum to discharge recording paper.

[0002]

2. Description of the Related Art Thermal printers are roughly classified into a thermal recording type and a thermal transfer type. In both cases, when thermal recording is performed on a recording paper, the edge of the recording paper is fixed with a clamper to reduce the friction coefficient. Recording paper is wrapped around a platen drum made of high rubber. Then, the thermal printer directly presses the recording paper, and the thermal transfer printer sandwiches the ink sheet between the thermal paper and the recording paper and presses the thermal head on which the heating elements are formed in a line shape to apply thermal energy according to the image data. The thermal recording is done by.

When ejecting a recorded recording sheet, the thermal head is strongly pressed against the recording sheet to release the clamper from the fixed state, and then the platen drum is rotated. At this time, the recording paper is held by the platen drum having a larger frictional resistance than the thermal head, so that the recording paper rotates together with the platen drum and is fed into the paper discharge passage.

[0004]

However, in the above-mentioned head pressing and discharging method, a large load is applied to the platen drum, so that the discharging speed cannot be made high. Further, since the print surface of the recording paper moves while being strongly pressed against the thermal head, scratches or scratches due to friction may occur, which may impair print quality.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a paper discharge device for a thermal printer that improves the paper discharge speed and reduces the occurrence of scratches on recording paper. Is.

[0006]

In order to achieve the above-mentioned object, the invention according to claim 1 is a thermal printer in which recording paper is wound around a platen drum, and a thermal head is pressure-bonded to the recording paper to perform recording. Thermal head moving means for moving the thermal head between the recording position where the thermal head is pressed against the paper and the discharge position away from the recording paper, and the recording paper is pressed against the platen drum when the thermal head is at the discharge position. And a paper pressing means for rotating the recording paper together with the platen drum during discharging.

According to a second aspect of the present invention, the paper pressing means is composed of a main body portion having a spring property and a roller portion rotatably supported by the main body portion and rotating in contact with the platen drum. Is.

According to the third aspect of the present invention, a clamper for pressing the front end of the recording paper is provided, and when the paper is discharged, the paper presser is released and kept in a stopped state, and the recording paper is passed under the clamper to discharge the paper. It was sent to.

Further, in the invention of claim 4, the thermal head moving means can further move the thermal head to the retracted position, and at the retracted position, the thermal head and the paper pressing member are sufficiently retracted so as not to collide with the clamper. This is what you are doing.

Upon discharging the paper, the thermal head moving means moves the thermal head to a paper discharging position apart from the recording paper. At this time, the paper pressing member presses the recording paper, but presses the recording paper with a pressure force weaker than the pressure force of the thermal head. Also, the clamper lifts from the recording paper and releases the fixing of the leading end. When the platen drum rotates to eject the paper, the recording paper is pressed by the paper pressing member and rotates together with the platen drum. This recording paper separates from the platen drum due to the rigidity of the paper and enters the paper discharge passage.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 showing an outline of a color thermal printer, a plurality of sheet-shaped color thermal recording papers 10 are stacked in a cassette 11, and the uppermost one is formed by a paper feed roller 12. Pushed out, paper feed path 13
Sent to. A conveyance roller pair 14 is provided in the paper feed path 13 and feeds the color thermosensitive recording paper 10 fed from the cassette 11 toward the platen drum 15. The platen drum 15 is rotationally driven by a stepping motor 17 via a platen shaft 16.

On the platen drum 15, the front end portion 10a of the color thermosensitive recording paper 10 is attached to the outer peripheral surface 1 of the platen drum 15.
A clamper 20 is provided to press and fix to 5a. The clamper 20 is shifted by a shift mechanism 22 in three stages of a clamp position, a paper feed position, and a paper discharge position.
Further, the clamper 20 has a wide portion 21a and a narrow portion 21b.
A groove 21 composed of and is formed, and a platen shaft 16 having an end surface of a substantially D shape is fitted therein. During discharging, the clamp mechanism 20 resists the spring 23 by the shift mechanism 22.
Since the platen shaft 16 is pushed up, the platen shaft 16 has the wide portion 21a.
Enter and spin freely in this. At this paper discharge position, the distance between the tip of the claw 20c and the outer peripheral surface 15a of the platen drum 15 is sufficiently large, the color thermosensitive recording paper 10 can pass through the clamper 20, and the normal paper discharge can be performed.

During printing, the platen shaft 16 moves the narrow portion 2
1b, and the clamper 20 rotates together with the platen shaft 16 when the platen shaft 16 rotates. At this time, as shown in FIG. 3, the claws 20c of the clamper 20 enter the grooves 15b formed in the outer peripheral surface 15a of the platen drum 15. During feeding, as shown in FIG. 2, the platen shaft 1
6 is located between the wide portion 21a and the narrow portion 21b. At this paper feeding position, the tip portion 10a of the color thermosensitive recording paper 10 is not fixed, but the claw 20c of the clamper 20 is not completely pulled out from the groove 15b, and the tip portion 10a abuts on the claw 20c. The thermal recording paper 10 is prevented from passing through.

A thermal head 24 is disposed on the outer periphery of the platen drum 15 at the thermal recording position of the color thermal recording paper 10, and a magenta light fixing lamp 25 is provided at a position close to the thermal head 24 on the downstream side thereof. Light fixing lamps 26 for yellow are arranged downstream of the lamps. The optical fixing lamp 25 for magenta has a light emission peak of about 3
The 65 nm yellow light fixing lamp 26 has an emission peak of approximately 420 nm, and both are made up of rod-shaped ultraviolet lamps.

The thermal head 24 comprises a head body 29 and a head holder 30. This head body 2
As is well known, a large number of heating elements 31 are arranged in a line shape in the main scanning direction at 9 and each heating element 31 generates thermal energy according to the density of the pixel. Further, the head main body 29 is arranged in the head holder 30, and is connected via a spring 32 that adjusts the pressing force of the head main body 29 against the color thermosensitive recording paper 10. This head body 2
9 and the head holder 30 are rotatably attached to a shaft 33. Further, a roller 34 and a spring 35 are provided on the upper surface of the head holder 30.
The head body 29 is urged in the clockwise direction in the figure by the urging force of 5 through the head holder 30.

A head cam 36 is provided above the head holder 30 so as to be rotatable around a shaft 37, and a roller 34 is in contact with an outer peripheral surface thereof by a bias of a spring 35. On the outer peripheral surface of the head cam 36, a cam surface 36a for setting the head holder 30 to the retracted position shown in FIG. 2, a cam surface 36b for setting the paper ejection position shown in FIG. 1, and a recording position shown in FIG. A cam surface 36c for setting is formed.

Further, the thermal head 24 is provided with a paper pressing member 38 for pressing the color thermosensitive recording paper 10 against the platen drum 15 during paper ejection. As shown in FIG. 4, the paper pressing member 38 is U-shaped, has a spring property as a whole, and is composed of a main body 39 and roller portions 40 whose both ends are wound springs. The roller portion 40 has 4
The 0a portion has a large stepped outer diameter, and the 40a portion is arranged so that it is located outside the image and the inside of the width of the recording paper.

In the main body 39, a winding spring portion 39a is inserted through a shaft 41, and an end portion 39b thereof is locked by a pin 42 provided on the head holder 30. Roller section 40
Is molded of resin and presses the paper while rotating together with the platen drum 15. Due to the springiness of the main body portion 39, the color thermosensitive recording paper 10 is lightly pressed with a constant pressing force, and the roller portion 40 rotates together with the platen drum 15, whereby the rotational load of the platen drum 15 can be reduced. Reference numeral 43 is a pin for lifting the main body 39.

A stopper 44 is provided between the thermal head 24 and the magenta optical fixing lamp 25 at a position closer to the magenta optical fixing lamp. This stopper 44
After the clamper 20 is moved to the paper discharge position (see FIG. 1) to release the fixing of the color thermosensitive recording paper 10,
The clamper 20 is prevented from rotating so that the clamper 20 does not rotate together with the platen drum 15.

Between the magenta optical fixing lamp 25 and the yellow optical fixing lamp 26, there is provided a paper discharge passage 45 for discharging the color thermosensitive recording paper 10 on which all thermal recording has been completed. The paper discharge path 45 is provided with a pair of transport rollers 47 for gripping the color thermosensitive recording paper 10 and transporting it toward a paper discharge tray 46.

FIG. 5 shows an example of the color thermosensitive recording paper 10. The cyan thermosensitive coloring layer 5 is provided on the support 50.
1, a magenta thermosensitive coloring layer 52 having a photo-fixing property with an ultraviolet ray of about 365 nm, a yellow thermo-sensitive coloring layer 53 having a photo-fixing property with an ultraviolet ray of about 420 nm, and a protective layer 54 are sequentially formed. In this embodiment, the yellow thermosensitive coloring layer 53 has the lowest coloring thermal energy and the cyan thermosensitive coloring layer 51 has the highest coloring thermal energy.

Next, the operation of the above embodiment will be briefly described. At the time of sheet feeding, the platen drum 15 is stopped at the set position shown in FIG. The thermal head 24 is in the retracted position, and the heat generating portion 31 and the paper pressing member 38 are provided so that the clamper 20 can pass under the thermal head 24.
Are largely separated from the platen drum 15. Also,
The clamper 20 is moved to the sheet feeding position by the shift mechanism 22. The conveying roller pair 14 holds the color thermosensitive recording paper 10 supplied from the cassette 11 by the paper feeding roller 12 and conveys it toward the platen drum 15.

At the same time when the front end portion 10a of the color thermosensitive recording paper 10 comes into contact with the claw 20c of the clamper 20, the conveying roller pair 14 is temporarily stopped. Next, since the shift mechanism 22 retracts, the spring 23 pulls the clamper 20 back to the clamp position, and the front end portion 10 of the color thermosensitive recording paper 10 is pulled back.
a is fixed by the clamper 20. After this fixing, the stepping motor 17 is driven to rotate the platen drum 15 and the conveying roller pair 14, so that the color thermosensitive recording paper 10 is wound around the outer peripheral surface 15 a of the platen drum 15.

When the platen drum 15 rotates and the clamper 20 passes the head main body 29, the head cam 36 is rotated by the motor and the roller 34 contacts the cam surface 36c. As a result, the thermal head 24 rotates counterclockwise against the spring 35 with the shaft 33 as a fulcrum, and is set to the recording position shown in FIG. At this recording position, the roller portion 40 of the paper pressing member 38 and the heating element 31 come into contact with the color thermosensitive recording paper 10. The thermal head 24 presses the color thermosensitive recording paper 10 with a constant pressing force by the spring 32. Similarly, the roller portion 40 of the paper pressing member 38 presses the color thermosensitive recording paper 10 with a constant pressing force by the spring property of the main body 39.

When the platen drum 15 further rotates and the leading end of the recording area of the color thermosensitive recording paper 10 reaches the heat generating element 31, the heat generating element 31 is turned into the yellow heat sensitive coloring layer 5.
Heat is generated according to the thermal sensitivity of 3, and the yellow image is thermally recorded line by line. This heat-recorded yellow thermosensitive coloring layer 5
When 3 reaches the light fixing lamp 26 for yellow, almost 42
Near-ultraviolet rays near 0 nm are applied to the color thermosensitive recording paper 10 and are fixed to the extent that the yellow thermosensitive coloring layer 53 does not develop color at the time of the next thermal recording of the magenta thermosensitive coloring layer 52.

When all the thermal recording on the yellow thermosensitive coloring layer 53 is completed, the head cam 36 rotates counterclockwise and the cam surface 36a contacts the roller 34. Thermal head 2
4 rotates clockwise about the shaft 33 and moves to the retracted position shown in FIG. 2 again.

When the platen drum 15 further rotates and the clamper 20 again passes under the retracted thermal head 24, the thermal head 24 is set to the recording position. Then, when the tip of the recording area reaches the heating element 31, the magenta image is thermally recorded line by line on the magenta thermosensitive coloring layer 52, and when the portion on which the magenta image is thermally recorded reaches the magenta optical fixing lamp 25, the magenta image is printed. The light fixing lamp 25 irradiates the color thermosensitive recording paper 10 with ultraviolet rays in the vicinity of 365 nm to fix the magenta thermosensitive coloring layer 52. During the fixing of the magenta thermosensitive coloring layer 52, the yellow light fixing lamp 26 is turned off. When the thermal recording of the magenta image on the magenta thermosensitive coloring layer 52 is completed, the thermal head 24 moves to the retracted position.

Next, when the color thermosensitive recording paper 10 faces the thermal head 24, the thermal head 24 is heated by the heat generating portion 31 as in the case of the yellow image and the magenta image described above.
And press the paper pressing member 38 against the color thermosensitive recording paper 10,
A cyan image is thermally recorded line by line on the cyan thermosensitive coloring layer 51. When all the thermal recording of the cyan image on the cyan thermosensitive coloring layer 51 is completed, the thermal head 24 moves to the retracted position with respect to the platen drum 15 as in the case of the yellow image and the magenta image. The cyan thermosensitive coloring layer 51 has such a value that the coloring heat energy does not develop in a normal storage state, so that the cyan thermosensitive coloring layer 51 is not provided with optical fixing property. Therefore, in the thermal recording of the cyan thermosensitive coloring layer 51, both the yellow optical fixing lamp 26 and the magenta optical fixing lamp 25 are in the OFF state.

After the thermal recording of the cyan image is completed, when the clamper 20 passes under the thermal head 24 in the retracted state, the platen drum 15 stops. Head cam 36
Is rotated clockwise, and the thermal head 24 is moved to the discharge position where the roller 34 contacts the cam surface 36b as shown in FIG.
Is set. At this paper discharge position, the paper pressing member 38
Only the roller portion 40 of the abutting contact with the color thermosensitive recording paper 10,
The heating element 31 is separated. At the same time, the shift mechanism 22 pushes up the clamper 20, and the color thermosensitive recording paper 1
The leading end portion 10a of 0 is set to the paper discharge position where the fixation is released.

Next, the platen drum 15 and the paper discharge passage 45
And the pair of transport rollers 47 of No. 1 starts to rotate. When the platen drum 15 rotates, the clamper 20 moves the platen shaft 1
6 is in the wide portion 21a, but rotates together. Then, when the clamper 20 hits the stopper 44, it is stopped by this and only the platen drum 15 rotates.
At this time, the platen shaft 16 idles in the wide portion 21a.

Since the color thermosensitive recording paper 10 is pressed by the roller portion 40 during the paper discharge, it is held on the platen drum 15 and rotates together with it due to the difference in frictional resistance between the platen drum 15 and the roller portion 40. Due to the rotation of the platen drum 15, the front end portion 10a of the color thermosensitive recording paper 10 that has passed through the clamper 20 separates from the platen drum 15 into the paper discharge passage 45 and is gripped by the conveying roller pair 47 due to its own rigidity. Be done. The color thermosensitive recording paper 10 is discharged to the tray 46 via the paper discharge passage 45. Since the roller portion 40 has the stepped shape as described above, it does not press the image print surface, so that the print surface is not scratched. When the paper discharge is completed, the thermal head 24 moves to the retracted position in preparation for the next thermal recording, and the platen drum 15 also rotates to the paper feed position.

Further, the magenta optical fixing lamp 25 is turned on at the time of discharging the sheet, whereby the tip end portion 10a covered with the clamper 20 and having a yellow color is irradiated with ultraviolet rays to be bleached. As described above, the bleaching of the clamped portion is performed during the paper discharge, so that the printing time can be shortened as compared with the case where the bleaching is performed separately.

The paper pressing member 38 of the above embodiment is composed of a wire spring in order to have a spring property, but as shown in FIG. 6, a U-shaped plate spring 60 with a rounded tip may be used. Good. Further, as shown in FIG. 7, the paper pressing member 61 may be provided on the upstream side in the rotation direction of the platen drum. Although the paper pressing member 38 is attached to the head 24 in the above embodiment, the paper pressing member 70 is attached to the end portion 70a as shown in FIG.
It is fixed to a part 71 of the thermal printer body. The head cam 72 has a convex portion 70 b provided on the paper pressing member 70.
A pin 72a for pushing is provided, and the paper pressing member 70 is pressed against the recording paper 10 only at the paper discharge position corresponding to FIG. This enables the platen drum 15 being printed.
The load on the recording paper 10 is further reduced, and scratches on the recording paper 10 are further eliminated.

Further, although the above-described embodiment is a color thermal printer using cut paper, it can also be applied to a color thermal printer using roll paper and a thermal transfer printer using cut paper or roll paper.

[0035]

According to the present invention having the above-described structure, since the paper pressing member is provided and the recording paper is pressed against the platen drum at the time of paper discharge, the load on the platen drum is reduced as compared with the conventional paper discharge system. High-speed paper ejection is possible. Further, by attaching a roller to the portion of the paper pressing member that comes into contact with the recording paper, it is possible to reliably prevent the recording paper from being scratched or scratched due to friction.

[Brief description of drawings]

FIG. 1 is a schematic view of a thermal printer showing a discharged state of color thermal recording paper.

FIG. 2 is a schematic view of a main part showing a feeding state of color thermosensitive recording paper.

FIG. 3 is a schematic view similar to FIG. 2 showing a thermal recording state of color thermal recording paper.

FIG. 4 is a perspective view showing an appearance of a paper pressing member.

FIG. 5 is an explanatory diagram showing a layer structure of color thermosensitive recording paper.

FIG. 6 is a perspective view showing an appearance of a paper pressing member using a leaf spring.

FIG. 7 is a schematic view showing an embodiment in which a paper pressing member is provided on the downstream side of a thermal head.

FIG. 8 is a schematic view showing an embodiment in which a paper pressing member is attached to a portion other than a thermal head.

[Explanation of symbols]

 10 Color thermal recording paper 15 Platen drum 20 Clamper 24 Thermal head 25 Optical fixing lamp for magenta 26 Optical fixing lamp for yellow 34 Roller 36,72 Head cam 38,60,61,70 Paper pressing member 40 Roller

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B41J 25/304 9305-2C B41J 3/20 117 A 25/30 L

Claims (4)

[Claims] 1. A thermal printer in which recording paper is wound around a platen drum, and a thermal head is pressed against the recording paper for recording, wherein a recording position where the thermal head is pressed against the recording paper and a discharge position apart from the recording paper. And a thermal head moving means for moving the thermal head, and a paper presser for pressing the recording paper against the platen drum when the thermal head is at the paper ejection position and rotating the recording paper together with the platen drum during paper ejection. A sheet discharge device for a thermal printer, which is provided with a means. 2. The paper pressing means comprises a main body having a spring property and a roller portion rotatably supported by the main body and rotating in contact with a platen drum. Discharge device for the thermal printer described. 3. A clamper for pressing the front end of the recording paper is provided, and when the paper is ejected, the paper presser is released and kept in a stopped state, and the recording paper is fed under the clamper into the paper ejection passage. The paper discharge device for a thermal printer according to claim 1 or 2. 4. The thermal head moving means further moves the thermal head to a retracted position, and at this retracted position, the thermal head and the paper pressing member are sufficiently retracted so as not to collide with the clamper. The paper discharge device of the thermal printer according to claim 1.