JP2712294B2 - Thermal transfer recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a surface-sequential thermal transfer recording apparatus that reciprocates a recording sheet along the outer periphery of a platen, such as a color printer.

As a conventional thermal transfer recording apparatus, for example, JP-A-60-3268
The thing disclosed in No. 7 gazette is known.

In this apparatus, a thermal head is provided near a platen. A thermal transfer ribbon is interposed between these platens and the thermal head. The thermal head presses the paper against the platen via the ribbon.
The ink on the ribbon is heated and melted and transferred to paper.

The thermal transfer ribbon is approximately the same size as the paper,
The ink portions of magenta, cyan, and the like are sequentially arranged and provided, and each ink is transferred one by one on a sheet. Therefore, at the end of printing of one color, the paper needs to be moved back along the outer periphery of the platen in the direction opposite to the conveyance direction at the time of printing before the ink of the next color is overprinted. When returning, the thermal head is located at a position separated from the platen.

That is, at the time of printing, the thermal head is pressed against the platen while the paper is conveyed in a predetermined direction, and printing is performed. After printing of one color is completed, the thermal head is separated from the platen, and the paper is moved back in the direction opposite to the conveying direction at the time of printing, whereby the leading end of the printing portion of the paper is returned to the position facing the thermal head. Further, the thermal transfer ribbon is wound up by a predetermined amount so that the ink portion of the next color reaches the position facing the thermal head. Thereafter, the thermal head is pressed again to perform printing of the second color. Further, this operation is repeated to print three colors and four colors.

Here, in the conventional apparatus, even when the thermal head is separated from the platen, the paper is wrapped around the platen even at the end of printing for the purpose of ensuring that the paper moves back. Is maintained at the rear end of the sheet by a pressing roller against the outer periphery of the platen.

<Problems to be Solved by the Invention> However, in such a conventional thermal transfer recording apparatus, as described above, even at the end of printing, the rear end of the paper needs to be pressed against the outer periphery of the platen by the pressing roller. Therefore, there has been a problem that the range of paper to be printed by the thermal head has been narrowed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a thermal transfer recording apparatus capable of reliably transporting a recording sheet and printing on the entire area.

<Means for Solving the Problems> As a specific means for achieving the above object, the present invention relates to a recording paper that reciprocates along the outer periphery of a platen roller, and the recording head is moved by an ink film when the recording paper moves forward. In the thermal transfer recording apparatus in which the recording head is retracted when the recording paper is moved back, the recording head approaches the outer periphery of the platen roller when the recording head is retracted, and the recording paper transport path is moved. A guide member to be formed is provided.

<Operation> According to the thermal transfer recording apparatus of the present invention, the recording paper is reciprocated along the outer periphery of the platen roller, and the recording head is pressed against the recording paper via the ink film when the recording paper moves forward to perform recording. At the same time, when the recording paper is moved back, the recording head is retracted, and the guide member approaches the outer periphery of the platen roller to form a recording paper conveyance path.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings.

1 and 2 are schematic side views showing a main part of a thermal transfer recording apparatus (color printer) according to a first embodiment of the present invention.

In these figures, reference numeral 11 denotes a driving roller (hereinafter, platen), and a belt 13 for the platen is stretched.

Paper transport belts 15 and 17 are disposed above and below the belt 13, respectively. 19 and 21 are paper transport belts 15, respectively.
17 drive rollers.

The sheet-shaped recording paper 23 is conveyed from a paper feed unit (not shown) between the belts 13 and 17. Then, the recording paper after printing on the platen 11 is carried out with being sandwiched between the belts 13 and 15.

Reference numeral 25 denotes a thermal head as a recording head. The thermal head 25 is swingably provided about a shaft 27 as a fulcrum. Thermal head 25 is platen 11
, The pressure contact position (the position shown in FIG. 1) and the retreat position (the position shown in FIG. 2).

In the figure, an ink film 31 is provided so as to run between the outer periphery of the platen 11 and the thermal head 25. When the thermal head 25 is at the pressure contact position, the ink film 31 is pressed against the outer surface of the recording paper 23.

Reference numeral 33 denotes a peeling roller for peeling the ink film 31 from the recording paper 23. The peeling roller 33 swings integrally with the thermal head 25.

A guide plate 41 is provided above and in the vicinity of the platen 11 such that the guide plate 41 can swing about the swing shaft 43 as a fulcrum. Guide plate
41 is curved to form a quarter of an arc.

As shown in FIG. 2, the guide plate 41 forms a conveyance path for the recording paper 23 by approaching the outer periphery of the platen 11. At this time, the guide plate 41 is positioned by the stopper 45. When the thermal head 25 swings to the retreat position via a mechanism (not shown), the guide plate 41 swings in conjunction therewith to form a transport path.

A sensor 47 detects whether or not the recording paper 23 is conveyed.

Therefore, in the color printer having the above configuration, at the time of starting printing, the recording paper 23 is conveyed toward the platen 11 while being sandwiched between the belts 13 and 17. This is detected by the sensor 47, and the thermal head 25 is swung to the pressure contact position. At this time, it is assumed that the ink film 31 has a predetermined color, for example, a yellow portion is located at a position facing the thermal head 25. Then, first, as the first printing, the ink film 31 is pressed against the outer surface of the recording paper 23 by the thermal head 25 to perform yellow printing.

At this time, the guide plate 41 swings upward and does not interfere with the pressing of the thermal head 25 against the platen 11.

After the end of the yellow printing, the recording paper 23 is carried out to a predetermined stock position by the belts 13 and 15, and the thermal head 25 swings to the retracted position. At the same time, the ink film 31 is also separated from the platen 11.

The guide plate 41 swings in the clockwise direction in the figure in conjunction with the swing and is positioned by the stopper 45.
A transport path is formed between the outer circumference of the platen 11 and the transport path. FIG. 2 shows this state.

Thereafter, the belts 13 and 15 are driven in the opposite direction. Accordingly, the recording paper 23 travels in the reverse direction on the transport path formed by the guide plate 41 as described above, and returns to the predetermined position.

At this time, after the next color, for example, the magenta portion of the ink film 31, reaches the position facing the thermal head 25, printing is performed by swinging the thermal head 25 to the press-contact position again as described above. The thermal head
When the lever 25 swings from the retracted position to the pressure contact position, the guide plate 41 swings from the transport path forming position to the separated position in conjunction with the swing movement.

Such an operation is repeated for three or four colors. By repeating this, desired color printing is performed on the recording paper 23.

3 and 4 show an example of an interlocking mechanism between the guide plate 41 and the thermal head 25 in the embodiment of the present invention.

In this example, the thermal head 25 and the guide plate 41 are interlocked via a cam mechanism 51.

The thermal head 25 is swung by a drive lever 53. The drive lever 53 drives (oscillates) the thermal head 25 by means of a cam plate 55 that is rotationally driven with a timing based on the time when the leading and trailing ends of the recording paper 23 are detected by the sensor 47.

That is, the circular cam plate 55 is rotatably supported around the shaft 57 as a center axis. In addition, a cam groove 59 arranged in a predetermined shape is formed in the cam plate 55. Cam groove
59 is an arc-shaped portion 59A that is short in the radial direction, and a longest portion 5 that extends radially outward from the arc-shaped portion (shortest portion) 59A.
9B.

A pin 61 is inserted into and engaged with the cam groove 59. The pin 61 protrudes from a swing link 65 that is swingably provided about a swing shaft 63 as a fulcrum.

Therefore, the swing link 65 is connected to the cam groove 59 via the pin 61.
At a distance in the radial direction from the shaft 57 of the
Accordingly, it swings around the swing shaft 63 as a fulcrum.

The tip of the swing link 65 is connected to the drive lever via a pin 67.
It is rotatably connected to one end of 53. The drive lever 53 is supported so as to be swingable about a shaft 69 provided at the center in the longitudinal direction. A long hole 71 is formed at the other end of the drive lever 53.

A guide rod member 73 is movably inserted into the elongated hole 71. The guide bar member 73 is fixed to one end of the leaf spring 75.
The other end of the leaf spring 75 is fixed or locked to a part of the thermal head 25.

Therefore, when the drive lever 53 is swung from the state shown in FIG. 4 to the state shown in FIG. 3 through the swing link 65 by the rotation of the cam plate 55, the plate spring 75 causes the thermal head 25 to move the platen 11
Is pressed by the elastic force toward the outer periphery of the.

On the other hand, the cam plate 77 arranged coaxially with the cam plate 55 rotates integrally with the cam plate 55 about the shaft 57.

The cam plate 77 has the longest position 59 in the radial direction of the cam groove 59.
A pin 79 protrudes from B by a predetermined angle in the circumferential direction. The pin 79 can be engaged with a protruding portion 85 which is one end of a rotating plate 83 rotatably supported on the shaft 81.

One end of a wire 87 is connected to the other end of the rotating plate 83. The other end of the wire 87 is connected to one end of the guide plate 41. Reference numerals 89 and 91 are pulleys around which the wire 87 is wound.

The guide plate 41 is provided so as to be swingable about a swing shaft 43 as a fulcrum. One end of the guide plate 41 is connected to a release spring 93 which urges the wire 87 in a direction opposite to the urging direction (clockwise direction in the figure), that is, in a counterclockwise direction in these figures. ing.

The operation of the thermal head 25 and the guide plate 41 via the cam mechanism 51 having the above configuration will be described.

FIG. 3 shows a case where the thermal head 25 is at the pressure contact position. FIG. 4 shows the case where the robot is at the retreat position.

In order to drive the thermal head 25 from FIG. 4 to FIG. 3, the cam plate 55 is rotated clockwise by a predetermined angle.
The pin 61 located at the shortest portion 59A of the cam groove 59 is guided by the cam groove 59 and moves to the longest portion 59B.

That is, the swing link 65 swings counterclockwise by a predetermined angle. As a result, the drive lever 53 swings about the shaft 69 by a predetermined angle in the counterclockwise direction.

Therefore, when the drive lever 53 is swung from the state shown in FIG. 4 to the state shown in FIG. 3, the leaf spring 75 presses the thermal head 25 toward the outer periphery of the platen 11 by its elastic force.

At the same time, the pin 79 also rotates by a predetermined angle, and the engagement of the rotating plate 83 engaged with the protrusion 85 is released. as a result,
The guide plate 41 is rotated by a predetermined angle counterclockwise by being urged by the release spring 93. That is, as shown in FIG. 3, the guide plate 41 is separated from the platen 11 and does not form a transport path. At this time, the rotating plate 83 is pulled in the clockwise direction via the wire 87 by the urging of the release spring 93.

In this pressed state, predetermined printing is performed, and in the retracted state, the recording paper is conveyed in the opposite direction.

In this example, even if there is not enough space around the platen in the arrangement of the cam mechanism, the configuration using the wire 87 has a high degree of freedom in design and is advantageous.

5 and 6 show another example of the interlocking mechanism between the guide plate 41 and the thermal head 25 in the embodiment of the present invention. This example uses a spring mechanism 101 instead of the cam mechanism of the previous example.
Thus, the thermal head 25 and the guide plate 41 are linked. The swing mechanism of the thermal head 25 is the same as that of the previous example, and the description thereof will be omitted below.

 Hereinafter, the spring mechanism 101 will be described.

One end of a leaf spring 75 for urging the thermal head 25 toward the platen 11 has the same shaft as that of the above-described example.
It is fixed on the 27 side. The guide bar member 73 fixed to the other end of the leaf spring 75 is loosely inserted into the one end slot 105 of the timing plate 103.

One end of a restraining spring 107 is locked to the other end of the timing plate 103. The other end of the restraining spring 107 is fixed to the guide plate 41.

That is, the guide plate 41, which forms the recording paper conveyance path along the outer periphery of the platen 11, may be urged in the clockwise direction about the swing shaft 43 by the restraining spring 107 and the plate spring 75 in the drawing. . At the same time, the guide plate 41 is urged by the release spring 93 in the counterclockwise direction opposite thereto. FIG. 5 shows a case where the urging force of the release spring 93 is large.

When the sensor detects the recording paper, as shown in FIG.
At a certain time, the thermal head 25 is pressed against the platen belt 13 via the recording paper and the ink film. For example, yellow printing is performed.

After yellow printing, the recording paper returns to a predetermined position in preparation for the next magenta printing.

In this case, the thermal head 25 is released from the pressure contact position and swings to the retreat position.

With this swing, the guide plate 41 swings clockwise via the leaf spring 75 and the restraining spring 107. That is, the leaf spring 75 rotates clockwise about the shaft 27 by a predetermined angle. The guide bar member 73 pulls down the timing plate 103 through the long hole 105 as shown in FIG. Therefore, the restraining spring 107 expands and exerts an elastic force. That is, the guide plate 41 is swung to the state where the transport path is formed (FIG. 6). When the elastic force of the restraining spring 107 is small, the initial tension of the restraining spring 107 may be set to be large.

The guide plate 41 contacts the stopper 45 to form a conveyance path along the outer periphery of the platen 11. This is to guide the recording paper when returning.

Then, after the recording paper returns, when the recording paper is conveyed again and positioned at a predetermined position for magenta printing, the sensor detects this and swings the thermal head 25 to the pressure contact position in the same manner as described above. is there. Hereinafter, this operation is repeated.

When the thermal head 25 swings upward to take the pressure contact position, the guide bar member 73 moves up via the leaf spring 75. The timing plate 103 releases the guide plate 41 from the transport path position by the reaction force of the restraining spring 107 and the spring force of the release spring 93. Then, the guide rod member 73 is positioned in the state shown in FIG.

The slot 105 of the timing plate 103 provides a predetermined time difference between the movement of the thermal head 25 and the movement of the guide plate 41. Interference between the thermal head 25 and the guide plate 41,
This is to prevent contact.

According to this example, the configuration of the spring mechanism 101 can be simplified as compared with the cam mechanism of the previous example.

<Effects> As described above, according to the present invention, at the end of printing, it is not necessary to press the trailing end of the sheet by the pressing roller in order to maintain the state in which the sheet is wound around the platen. In this thermal transfer recording apparatus, the recording paper can be reliably transported many times, and printing can be performed over the entire area of the recording paper.

Further, according to the present invention, even when the diameter of the platen roller is reduced, occurrence of paper jam can be reliably prevented. That is, there is an effect that the size of the apparatus can be reduced as the platen diameter decreases.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing a main part of a thermal transfer recording apparatus according to a first embodiment of the present invention, and FIG. 2 is a schematic side view showing an operation of a main part of the thermal transfer recording apparatus according to the first embodiment. FIG. 3 is a schematic side view showing an example of an interlocking mechanism between the guide plate and the thermal head according to the embodiment of the present invention, FIG. 4 is a schematic side view showing the operation of the interlocking mechanism according to an example, FIG. FIG. 6 is a schematic side view showing another example of the interlocking mechanism between the guide plate and the thermal head according to the embodiment of the present invention. FIG. 6 is a schematic side view showing the operation of the interlocking mechanism according to another example. . 11 ... Platen, 23 ... Recording paper, 25 ... Thermal head, 41 ... Guide plate, 51 ... Cam mechanism.

Continuation of the front page (56) References JP-A-1-152082 (JP, A) JP-A-63-67171 (JP, A) JP-A-62-294572 (JP, A) Real opening 58-45061 (JP, A) , U)

Claims (1)

(57) [Claims] The recording paper is reciprocated along the outer periphery of a platen roller, and the recording head is pressed against the recording paper via an ink film when the recording paper moves forward, and the recording head is moved when the recording paper is moved back. A thermal transfer recording apparatus, wherein a retreating thermal transfer recording apparatus is provided with a guide member that forms a recording paper conveyance path by approaching an outer periphery of the platen roller when the recording head is retracted.