JPH08276634A - Thermal transfer printing machine - Google Patents

Abstract

PURPOSE: To simplify the mechanism of a thermal transfer printer and make it small with a spring unit. CONSTITUTION: The base end part of an arm 17 is pivoted by an arm support shaft 18 freely rotatably to a main body frame 11, and the heat radiation plate 24 of a head part 22 is supported freely swingably by a head part support shaft 21 at the end of the arm 17. A spring unit 15 is installed between the actuation shaft 14 of a cam 13 and the connection shaft 16 of the arm 17. By rotating the arm 17 by the cam 13 through the spring unit 15, the thermal head 25 of the head part 22 is made freely contactable/separable with/from a platen 27. The spring unit 15 presses the thermal head 25 to the platen 27 by a spring 44 which can be compressed in the range of a long hole 43. An ink sheet 31 and a recording medium 32 are sandwiched between the thermal head 25 and the platen 27 to perform printing etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printer, and more particularly, to a thermal transfer printer having a mechanism effective for cuing color ink sheets.

[0002]

2. Description of the Related Art Generally, a thermal transfer printer using an ink sheet holds a recording medium (paper) and an ink sheet between a thermal head and a platen at the time of printing, and also moves the recording medium and the ink sheet. It is necessary to lift up the thermal head from the platen when the sheet is cueed or when the ink sheet cassette is attached or detached.

For this reason, as disclosed in Japanese Utility Model Publication No. 5-47654, a cam lever actuated by a cam is disengageable on a head arm that supports a head portion such as a heat dissipation plate integrated with a thermal head. Providing an engagement mechanism and a spring to press the thermal head against the platen,
Then, by rotating the head arm by the cam via the cam lever, the head portion is moved toward or away from the platen, or the engagement between the cam lever and the engagement mechanism is released, so that the head is released. The part is largely open from the platen.

As described above, in the thermal transfer printer, a pressure mechanism for closely contacting the recording medium and the ink sheet in order to improve the fixability of the ink necessary for performing the thermal transfer color printing, the ink sheet cueing, and the ink sheet. Although a head-up mechanism necessary for replacing the sheet cassette etc. is provided,
In the conventional thermal transfer printer, the respective mechanisms are concentrated in the head portion or the vicinity thereof.

[0005]

As described above, the conventional thermal transfer printer has a complicated and large-sized mechanism mounted on the head portion, which is expensive and the apparatus itself is large. Further, basically, the above-mentioned mechanism has a structure that is difficult to be downsized and simplified.

The present invention has been made in view of the above circumstances, and an object thereof is to simplify and downsize a mechanism for moving a head portion in a thermal transfer printer.

[0007]

According to a first aspect of the present invention, a thermal head is provided so as to be capable of contacting and separating from a platen, and an ink sheet and a recording medium are sandwiched between the thermal head and the platen to perform thermal transfer. In a thermal transfer printer that performs the above, a head portion formed by integrating the thermal head with a heat dissipation plate is supported at the tip end portion, and an arm pivotally supported at a fixed position at the base end portion and an intermediate portion of the arm. Unit for connecting the head to the platen with a spring that expands and contracts within a certain range, and a cam that rotates the arm through the spring unit so that the head part can move toward and away from the platen. And a thermal transfer printer having a configuration including.

According to a second aspect of the present invention, as a spring unit in the thermal transfer printer according to the first aspect, one end of a spring mounting plate is rotatably fitted to an operating shaft of a disk type cam to mount the spring. A long hole is provided in the other end of the plate, the connecting shaft inserted in the middle part of the arm is loosely fitted in this long hole, the head pressing coil spring is fitted in the spring mounting plate, and one end of this coil spring is attached. The spring mounting plate abuts on a locking member provided on one end side and the other end abuts on the connecting shaft.

According to a third aspect of the present invention, in the thermal transfer printer according to the first aspect, the center of the head portion is swingably supported at the center of the arm tip end through a head portion support shaft. Is.

[0010]

According to the invention described in claim 1, only when the ink sheet cassette is exchanged, the head portion is sufficiently separated from the platen when the ink sheet cassette is exchanged, and the recording medium is fed. When cueing the ink sheet, make a small head-up state with a certain distance between the thermal head and the platen, and when printing, press the head part against the platen with the pressure required for printing by the spring unit. .

According to the second aspect of the present invention, when the arm is pulled through the spring mounting plate of the spring unit by the rotation of the cam, the separation distance between the thermal head and the platen is determined by the rotation stop position of the cam. Further, when the arm is pressed by the rotation of the cam via the spring of the spring unit, the spring is compressed within the long hole even after the head and the platen are engaged, so that the head necessary for printing can be obtained. Obtain a pressurized condition.

According to the third aspect of the present invention, the head portion swings about the head portion supporting shaft, whereby the thermal head and the platen are kept parallel to each other.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in FIGS.

As shown in FIG. 1, a disc type cam 13 is rotatably supported by a body frame 11 via a cam shaft 12.
The cam shaft 12 is rotationally driven by a motor (not shown) via a gear train (not shown).

An operating shaft 14 is inserted into the eccentric position of the disc type cam 13, one end of a spring unit 15 is connected through the operating shaft 14, and a connecting shaft 16 is connected to the other end of the spring unit 15. The middle part of the L-shaped arm 17 is connected via. The L-shaped arm 17 has a base end rotatably supported on the body frame 11 by an arm support shaft 18.

The L-shaped arm 17 is formed by forming a pair of arm plates 17a in a U shape through a head supporting portion 17b on the tip side when viewed in plan in FIG. A head support shaft 21 is inserted in the center of the head support shaft 21, and the mounting bracket 23 of the head 22 is pivotally supported by the head support shaft 21 at the center thereof. This allows the head portion 22 to freely swing and follow the platen described later in parallel.

The head portion 22 has the head supporting portion 17b.
A heat radiating plate 24 axially supported by the mounting bracket 23, and a thermal head 25 integrated on the lower surface of the heat radiating plate 24. The thermal head 25 is rotated around the main body frame 11 by a platen shaft 26. The platen 27, which is rotatably supported, is opposed to the platen 27 so that the platen 27 can freely come and go.

An ink sheet cue detection photosensor (reflective sensor) 28 necessary for cueing each color of the three color ink sheets is provided on the mounting member 23 of the heat dissipation plate 24.

Between the thermal head 25 and the platen 27, a three-color ink sheet 31 and a recording medium (paper) are provided.
Clamp 32. 33 is a cassette formed by winding the color ink sheet 31 inside.

In the spring unit 15, as shown in FIG. 4, a U-shaped spring pressing plate 42 as a locking member is integrally provided on the right end side of a U-shaped spring mounting plate 41. The mounting plate 41 and the spring pressing plate 42 are rotatably fitted on the actuating shaft 14 of the disc-shaped cam 13.

On the other hand, a rectangular elongated hole 43 is provided on the left end side of the spring mounting plate 41 as shown in FIG. 1, and the connecting shaft 16 of the L-shaped arm 17 is formed in the elongated hole 43 in the elongated hole direction. It loosely fits within the range of play.

A pair of head pressurizing coil springs 44 are fitted to the spring mounting plate 41 in a compressed state, and one end of the coil spring 44 abuts on the spring pressing plate 42 and the other end abuts on the connecting shaft 16.

Next, the operation of this embodiment will be described.

This mechanism transmits the power from a motor (not shown) to a disc type cam 13 via a gear train (not shown), and the rotation of the disc type cam 13 causes a spring unit 15 connected to its operating shaft 14 to move. The L-shaped arm 17 is rotated via the arm support shaft 18 as a fulcrum, and the head portion 22 supported by the tip of the L-shaped arm 17 is moved in the contact direction or the separation direction with respect to the platen 27. By controlling the rotation direction and rotation amount of the disk-shaped cam 13, the position of the head portion 22,
Control as follows.

(1) During cassette replacement As shown in FIG. 1, when the disc cam 13 is rotated clockwise and the operating shaft 14 thereof is moved rightward, the spring unit 15 is also moved rightward. At this time, the spring mounting plate 41 also moves to the right, the plate portion 41a at the left end thereof engages with the connecting shaft 16 of the L-shaped arm 17, the L-shaped arm 17 is rotated clockwise, and the head portion 22 is moved. Separated sufficiently from the platen 27. The cassette 33 of the ink sheet 31 is replaced with the head portion open.

(2) Feeding of Recording Medium and Cueing of Ink Sheet As shown in FIG. 2, when the cue detecting photosensor 28 of the three color ink sheet 31 is moved to the position of the reflecting plate (not shown), Stop the rotation of the disk type cam 13,
The movement of the head portion 22 via the spring unit 15 is stopped. At this time, a small head-up state in which a certain distance, which is not so large, is provided between the thermal head 25 and the platen 27 is set. In this state, the ink sheet 31
And the recording medium (paper) 32 are moved to the print start position.
That is, the cue of the ink sheet 31 and the recording medium (paper)
32 paper feeds.

In such a head-up state, generally, the cueing position of the ink sheet 31 is likely to shift, but in the present embodiment, the brake mechanism in the cassette 33 causes the ink sheet 31 to have a resistance in the pulling direction. The spring 44 is slightly actuated to apply a constant tension to the ink sheet 31, so that the thermal head 25 and the ink sheet 31 are kept in close contact with each other.

(3) At the time of printing As shown in FIG. 3, when the cam 13 is further rotated while the ink sheet 31 and the recording medium 32 stand by at the print start position, the thermal head 25 contacts the platen 27. Contact
In the meantime, the ink sheet 31 and the recording medium 32 are pressed. This stops the movement of the thermal head 25.

From this point, when the disc cam 13 is further rotated and the spring unit 15 is moved to the left, the spring pressing plate 42 moves to the left with respect to the connecting shaft 16 locked at a fixed position. The spring pressing plate 42 compresses the head pressing coil spring 44, and the repulsive force of the compression is applied to the thermal head 25 via the connecting shaft 16 and the arm 17.
And the head portion is pressed to obtain the pressure required for printing.

When the spring 44 is compressed to a position where the pressure required for this printing can be secured, the state is detected by a cam sensor (not shown) and drive transmission is stopped. In the present embodiment, the cam sensor may detect the rotation angle of the cam, and the head stop position, the pressurizing position, and the like may be detected and controlled.

With the structure as described above, each of the mechanical portions for holding, pressurizing the head portion 22, and following the platen 27 can be simplified as a small unit. In addition, assembling into a unit leads to improvement in assemblability and maintainability.

Although the example of the three-color ink sheet has been described in the embodiment, the present invention is also applicable to a thermal transfer printer using an ink sheet of one color or non-color, and an ink ribbon.

[0033]

According to the first aspect of the present invention, the head of the thermal head is simply provided between the cam and the arm by providing the spring unit for pressing the thermal head against the platen by the spring that expands and contracts within a certain range. Since the up and pressing of the platen can be performed, the mechanism can be simplified and downsized, and particularly, the mechanism in the head section can be simplified and downsized.

According to the second aspect of the present invention, the mechanism for supporting the thermal head when the thermal head is moved up and the pressure mechanism for elastically pressing the thermal head against the platen are combined into one block. It can be realized by a spring unit, which improves the assemblability and the maintainability.

According to the third aspect of the invention, the followability of the thermal head with respect to the platen can be ensured by the swingable structure of the head section around the head section support shaft.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a thermal transfer printer according to the present invention, showing a state in which a head portion is opened when a cassette is replaced.

FIG. 2 is a cross-sectional view showing a small head-up state when the recording medium is fed and the ink sheet is cued in the same printer.

FIG. 3 is a cross-sectional view showing a head portion pressurizing state at the time of printing in the printer.

FIG. 4 is a plan view of the same printer.

[Explanation of symbols]

 13 cam 14 actuating shaft 15 spring unit 16 connecting shaft 17 arm 21 head supporting shaft 22 head 24 heat sink 25 thermal head 27 platen 31 ink sheet 32 recording medium 41 spring mounting plate 42 spring pressing plate 43 as a locking member 43 long Hole 44 spring

Claims (3)

[Claims] 1. A thermal transfer printer, wherein a thermal head is provided so as to be movable toward and away from a platen, and an ink sheet and a recording medium are sandwiched between the thermal head and the platen to perform thermal transfer, the thermal head being integrated with a radiator plate. An arm that supports the head part that is made into a solid state and that is pivotally supported at a fixed position at the base end and a spring that is connected to the middle part of this arm and expands and contracts within a certain range A thermal transfer printer comprising: a spring unit for pressing a thermal head against a platen; and a cam for rotating the arm through the spring unit so that the head unit can be brought into and out of contact with the platen. 2. A spring unit, wherein one end of a spring mounting plate is rotatably fitted to an operating shaft of a disk type cam,
A long hole is provided in the other end of the spring mounting plate, the connecting shaft inserted in the middle part of the arm is loosely fitted in this long hole, and the head pressing coil spring is fitted in the spring mounting plate. The thermal transfer printer according to claim 1, wherein one end abuts on a locking member provided on one end side of the spring mounting plate and the other end abuts on the connecting shaft. 3. The thermal transfer printer according to claim 1, wherein the center of the head portion is swingably supported at the center of the arm tip portion through a head portion support shaft.