JPH08224933A - Head-up mechanism of thermal transfer printer - Google Patents

Abstract

PURPOSE: To provide the head-up mechanism of a thermal transfer printer suppressing the consumption of a thermal transfer ribbon by lifting up a thermal head from a platen roller without using a motor or other drive source other than a drive motor, having a simple mechanism reduced in the number of parts and reducible in cost. CONSTITUTION: The head-up mechanism of a thermal transfer printer is constituted noticing that an eccentric cam 43 is allowed to act on a thermal head 17 and has the eccentric cam 43 provided to the rotary shaft of a platen roller 16 and brought into contact with the thermal head 17 to move the thermal head in the direction separated from the platen roller 16 and the one-way clutch 44 loosely rotating the eccentric cam 43 when the platen roller 16 is rotated in a forward direction and rotating the same in the same direction when the platen roller 16 is rotated in the reverse direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head-up mechanism of a thermal transfer printer, and more particularly to a head-up mechanism of a thermal transfer printer for saving consumption of a thermal transfer ribbon.

[0002]

2. Description of the Related Art A conventional thermal transfer printer will be outlined with reference to FIGS. FIG. 6 is a schematic explanatory view of the thermal transfer printer 1. The thermal transfer printer 1 includes a print medium supply shaft 3 for a strip-shaped print medium 2 such as a label or a hanging tag, a main transfer mechanism 4, and a printing mechanism. 5, a ribbon supply shaft 7 of the thermal transfer ribbon 6, a ribbon winding shaft 8 of the thermal transfer ribbon 6, a head-up mechanism 9, and a control mechanism 10.
And.

The main transfer mechanism 4 has a drive motor 11 and a transfer roller 13 rotated by the drive motor 11 via a roller belt 12.

The printing mechanism 5 includes the drive motor 11 and the platen roller 1 rotated by the drive motor 11 via the platen belt 14 and the platen pulley 15.
6 and a thermal head 17. The printing mechanism 5 includes a platen roller 16 and a thermal head 17.
The medium to be printed 2 and the thermal transfer ribbon 6 can be sandwiched between and to be transferred, and also functions as a sub-transfer mechanism in synchronization with the main transfer mechanism 4.

By driving the drive motor 11, the print medium 2 is fed from the print medium supply shaft 3 and the thermal transfer ribbon 6 is supplied from the ribbon supply shaft 7, and the main transfer mechanism 4 and the print mechanism 5 synchronize them. It is supplied between the platen roller 16 and the thermal head 17.

Detection signals from the medium sensor 18 of the print medium 2 and the ribbon sensor 19 of the thermal transfer ribbon 6 are input to the control mechanism 10, and predetermined information is printed based on the predetermined print signal.

The head-up mechanism 9 includes a return spring 2
The thermal head 17 is opened and rotated around the head fulcrum shaft 21 against the biasing force of 0 to allow only the print medium 2 to pass therethrough, and the supply of the thermal transfer ribbon 6 is temporarily stopped. This is for suppressing the consumption of 6.

That is, FIG. 7 is a plan view of the print-receiving medium 2, in which the print-receiving medium 2 is located at the forefront of the first blank area in order from the transport direction of the arrow toward the upstream side of the print-receiving medium supply shaft 3. Section 22, first print area section 23, second blank area section 2
4, a second print area portion 25, a third blank area portion 26, a third print area portion 27, and a rearmost fourth blank area portion 28.

The first print area portion 23, the second print area portion 25 and the third print area portion 27 are used to print, for example, the price of goods, the classification number and other information. Blank area part 22, second blank area part 24,
The thermal transfer ribbon 6 that comes into contact with the third blank area portion 26 and the fourth blank area portion 28 is useless because it is not used for printing.

Therefore, the heating element 17 for printing of the thermal head 17 is provided in the first blank area portion 22, the second blank area portion 24, the third blank area portion 26 and the fourth blank area portion 28.
When the portion A is reached, the head-up mechanism 9 is driven to separate the thermal head 17 from the platen roller 16 so that only the print medium 2 is transported by the main transport mechanism 4 and the thermal transfer ribbon 6 is made to stand by at that portion. It is considered to be set.

FIG. 8 is a front view showing a specific structure of the head-up mechanism 9 as viewed from the transfer direction side, and the head-up mechanism 9 has a motor 29 for opening and closing.
And an eccentric cam 32 which is rotationally driven by the opening / closing motor 29 via the gear mechanism 30 and the cam rod 31,
The eccentric cam 32 disengages from the bracket 33 of the thermal head 17.

That is, the eccentric cam 32 lifts up the bracket 33, that is, the thermal head 17 by driving the opening / closing motor 29.

FIG. 9 is a front view of another head-up mechanism 34, showing the printing mechanism 5 from the transport direction side.
The head-up mechanism 34 includes an opening / closing solenoid 35.
A plunger 36 and an arm 37 connecting the thermal head 17 to the plunger 36.

By driving the opening / closing solenoid 35, the plunger 36 is projected upward in the drawing to lift and separate the thermal head 17 from the platen roller 16.

In the head-up mechanism 9 and the head-up mechanism 34, in addition to the drive motor 11 for the printing mechanism 5, a drive source such as the opening / closing motor 29 or the opening / closing solenoid 35 is required, and there are many mechanical parts and the mechanism is large. There is the problem of complexity.

[0016]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is possible to lift up a thermal head from a platen roller without using a motor or other drive source other than a drive motor. An object of the present invention is to provide a head-up mechanism of a thermal transfer printer that can perform the above.

Another object of the present invention is to provide a head-up mechanism for a thermal transfer printer, which has a simple mechanism with a reduced number of parts and which can reduce the cost.

A further object of the present invention is to provide a head-up mechanism for a thermal transfer printer which can suppress the consumption of the thermal transfer ribbon by lifting up the thermal head from the platen roller.

[0019]

That is, the present invention focuses on direct application of an eccentric cam to a thermal head, and includes a supply shaft for a print medium, a supply shaft for a thermal transfer ribbon and a take-up shaft, and a thermal shaft. A head and a platen roller are provided, and the print medium and the thermal transfer ribbon are sandwiched and transferred between the thermal head and the platen roller, and along with this transfer, predetermined information is transferred to the print area of the print medium. A head-up mechanism of a thermal transfer printer having a printing mechanism for printing, the eccentric cam being provided on the rotary shaft of the platen roller and abutting against the thermal head to move the thermal head in a direction away from the platen roller. , The eccentric cam is allowed to rotate when the platen roller rotates in the positive direction, and the platen roller is rotated. During reverse rotation of a head-up mechanism of the thermal transfer printer characterized by having a one-way clutch to rotate in the same direction.

The thermal head can be separated from the platen roller when the thermal head is located in a blank area located between the print areas of the print medium in the transport direction of the print medium. .

The thermal head can be separated from the platen roller by rotating the eccentric cam a half turn when the platen roller rotates in the opposite direction.

It is possible to transfer only the print medium while the thermal head is separated from the platen roller.

A transfer mechanism capable of transferring the print medium may be provided in synchronization with the print mechanism.

A single drive motor may be provided to drive the printing mechanism and the transfer mechanism.

The thermal head can be brought into contact with the platen roller by rotating the eccentric cam a half turn while the thermal head is separated from the platen roller.

The eccentric cam allows the thermal head to be opened and rotated about the head fulcrum shaft.

A return spring for urging the thermal head toward the platen roller is provided, and
The thermal head can be separated from the platen roller by the eccentric cam against the biasing force of the return spring.

[0028]

In the head-up mechanism of the thermal transfer printer according to the present invention, the eccentric cam acts directly on the thermal head in accordance with the rotation (reverse rotation) of the platen roller, so that the eccentric cam can be operated only by the drive motor for driving the platen roller. Since it can rotate, it is not necessary to separately provide a drive source such as a conventional open / close motor or open / close solenoid for driving the eccentric cam.

Therefore, in addition to the drive motor for the printing mechanism, only the eccentric cam and the one-way clutch are required as the head-up mechanism, and the cost can be reduced by a simple mechanism with a reduced number of parts.

Further, since the eccentric cam can directly act on the thermal head as the platen roller rotates in the reverse direction, the responsiveness is good and the head can be moved up with a smaller driving force.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a head-up mechanism 41 of a thermal transfer printer 40 according to an embodiment of the present invention will be described with reference to FIGS. However, the same parts as those in FIGS. 6 to 9 are designated by the same reference numerals, and the detailed description thereof will be omitted. FIG.
2 is a schematic explanatory view of the thermal transfer printer 40, and FIG. 2 is a front view of the head-up mechanism 41 as seen from the transfer direction side of the print medium 2, and the thermal transfer printer 40 is basically shown in FIG.
The print medium supply shaft 3, the main transfer mechanism 4, the printing mechanism 5, the ribbon supply shaft 7, the ribbon take-up shaft 8, and the control mechanism 10, which are similar to those of the thermal transfer printer 1 of FIG. A head-up mechanism 41 is provided instead of the mechanism 9 or the head-up mechanism 34.

The head-up mechanism 41 has an eccentric cam 43 coaxial with the rotary shaft 42 of the platen roller 16 and the platen pulley 15, and a one-way clutch 44 provided between the rotary shaft 42 and the eccentric cam 43.

The one-way clutch 44 idles the eccentric cam 43 when the platen roller 16 rotates in the positive direction, and allows the eccentric cam 43 to rotate in the same direction when the platen roller 16 rotates in the opposite direction.

FIG. 3 is an enlarged side view of the main part of the head-up mechanism 41 when the eccentric cam 43 is in the normal position, and FIG. 4 is an enlarged side view of the main part when the thermal head 17 is lifted up. When the eccentric cam 43 rotates 180 degrees from its normal position, its eccentric tip portion 43A contacts the bracket 45 of the thermal head 17 from below to open the thermal head 17 upward with the head fulcrum shaft 21 as a fulcrum. It is rotated to separate it from the platen roller 16.

Head-up mechanism 4 having such a configuration
1, the operation of lifting the thermal head 17 by the eccentric cam 43 will be described with reference to FIG. FIG. 5 shows steps (1) to (4) in order of lifting the thermal head 17 by the head-up mechanism 41 from the time when the printing of the first printing area portion 23 is completed and bringing the thermal head 17 into contact with the platen roller 16 again. In the first step (1), printing on the first printing area 23 is completed and the platen roller 16
Axis 16A (printing heating element 1 of the thermal head 17)
7A), the tail end of the first print area portion 23 is located.

In the first step (1), the main transfer mechanism 4
The print medium 5 and the thermal transfer ribbon 6 are transferred in the forward direction by rotating the printing mechanism 5 in the normal direction (indicated by the solid line arrow in the figure). At this time, the one-way clutch 44 acts to prevent the platen roller 16 from rotating in the normal direction. Eccentric cam 43
Is not transmitted to the eccentric cam 43, and the eccentric cam 43 is in a fixed position with the eccentric tip portion 43A facing downward.

In the second step (2), the drive motor 1
When the platen roller 16 is reversed in the opposite direction (dotted line arrow in the figure) by reversing 1, the eccentric cam 43 moves the platen roller 1 by the action of the one-way clutch 44.
6, the eccentric tip portion 43A lifts up the thermal head 17 against the biasing force of the return spring 20 and separates it from the platen roller 16.

At the time of reverse rotation of the platen roller 16, the drive motor 11 also reverses the transfer roller 13 of the main transfer mechanism 4 in the same manner as the platen roller 16, so that the print medium 2 is half of the platen roller 16 (or the eccentric cam 43). It retreats by the length of rotation (2 / L), but the thermal head 17
Is separated from the platen roller 16, the thermal transfer ribbon 6 transferred by the platen roller 16 and the thermal head 17 is not transferred and is in a stopped state. In the steps (1) to (4) of FIG. 5, the leading edge movement state of the second print area portion 25 is indicated by an imaginary line arrow.

In the third step (3), the main transfer mechanism 4 is driven while the thermal head 17 is in the lifted state to advance only the print medium 2. That is, the thermal transfer ribbon 6 is stopped and is not transferred when the print-receiving medium 2 advances.

The length of the forward movement is determined by the first print area 2
Second blank area portion 2 between the third print area portion 3 and the second print area portion 25.
If the length of 4 is P, then it is (P + L).

In the final fourth step (4), the platen roller 16 is further rotated by a half rotation by the drive motor 11 so that the main transfer mechanism 4 prints until the thermal head 17 contacts the platen roller 16. Only the medium 2 is retracted, and the platen roller 16
(Or the eccentric cam 43) is retracted by a half rotation length (2 / L).

Therefore, the transfer length (-2 / L) in the second step (2), the transfer length (P + L) in the third step (3), and the transfer length in the fourth step (4). The total length of (−2 / L) is the length (P) of the print-receiving medium 2.
The front end of the second print area 25 is positioned on the axis 16A of the platen roller 16, and the print medium 2 and the thermal transfer ribbon 6 are sandwiched between the thermal head 17 and the platen roller 16. Then, the preparation for starting the printing on the next second printing area portion 25 is completed.

Thereafter, the platen roller 16 is similarly rotated in the forward and reverse directions to rotate the eccentric cam 43 of the head-up mechanism 41 counterclockwise in the figure and lift up the thermal head 17 and platen roller 16.
Abut.

Therefore, the blank areas 22, 24, 2
When 6 and 28 reach the thermal head 17 or the heating element 17A for printing thereof, the thermal head 17 is separated from the platen roller 16 so that only the print medium 2 is advanced and the thermal transfer ribbon 6 is moved to that position. Since it can be stopped, the consumption of the thermal transfer ribbon 6 can be suppressed as much as possible.

In the above embodiment, the eccentric cam 4 is used.
Although the case where the thermal head 17 is lifted up by the half rotation of 3 has been described, the present invention can also be configured to lift up at any rotation angle other than a quarter rotation.

[0046]

As described above, according to the present invention, since the thermal head is lifted up by the eccentric cam synchronized with the platen roller, not only the thermal transfer ribbon can be effectively prevented from being consumed but also the component parts can be effectively prevented. The number of points can be reduced, and the cost can be reduced with a simple configuration.

[0047]

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of a head-up mechanism 41 of a thermal transfer printer according to an embodiment of the present invention.

FIG. 2 is a front view of the head-up mechanism 41 as seen from the side in which the print medium 2 is transported.

[FIG. 3] Similarly, in the head-up mechanism 41, an eccentric cam 4
FIG. 3 is an enlarged side view of an essential part when 3 is in a normal position.

FIG. 4 is an enlarged side view of an essential part of the thermal head 17 during lift-up.

FIG. 5 is a view showing the thermal head 1 driven by the head-up mechanism 41 from the time when printing on the first print area 23 is completed.
7 is an explanatory view showing a process of lifting up 7 and bringing it into contact with the platen roller 16 again, divided into processes (1) to (4) in order.

FIG. 6 is a schematic explanatory view of a conventional thermal transfer printer 1.

FIG. 7 is a plan view of the print medium 2 of the same.

FIG. 8 is a front view showing the specific structure of the head-up mechanism 9 as viewed from the transfer direction side, showing the printing mechanism 5.

FIG. 9 is a front view of another head-up mechanism 34 as viewed from the transfer direction side, where the printing mechanism 5 is viewed.

[Explanation of symbols] 1 thermal transfer printer 2 belt-shaped print medium such as label or hanging tag 3 print medium supply shaft 4 main transfer mechanism 5 print mechanism (sub transfer mechanism) 6 heat transfer ribbon 7 ribbon supply shaft 8 ribbon take-up shaft 9 Head-up mechanism 10 Control mechanism 11 Drive motor 12 Roller belt 13 Transfer roller 14 Platen belt 15 Platen pulley 16 Platen roller 16A Platen roller 16 axis 17 Thermal head 17A Thermal head 17 printing heating element 18 Printed medium 2 Of the medium sensor 19 Ribbon sensor of the thermal transfer ribbon 6 20 Return spring 21 Head fulcrum shaft 22 First blank area portion 23 First print area portion 24 Second blank area portion 25 Second print area portion 26 Third blank area Area part 27 Third print area part 28 Fourth blank area part 29 Motor for opening / closing 30 Gear mechanism 31 Cam rod 32 Eccentric cam 33 Bracket 34 Head up mechanism 35 Opening / closing solenoid 36 Plunger 37 Arm 40 Thermal transfer printer 41 Head up mechanism of thermal transfer printer 40 42 Rotating shaft of platen roller 16 Eccentric cam 43A Eccentric cam 43 eccentric tip portion 44 one-way clutch 45 bracket L length of one rotation of platen roller 16 (eccentric cam 43) P length of second blank area portion 24

Claims (9)

[Claims] 1. A print medium supply shaft, a thermal transfer ribbon supply shaft and a take-up shaft, a thermal head and a platen roller, and the print medium and the thermal transfer ribbon between the thermal head and the platen roller. Is a head-up mechanism of a thermal transfer printer having a printing mechanism that nips and transfers a predetermined information in the printing area portion of the print medium with the transfer, and a rotary shaft of the platen roller. An eccentric cam that is provided and that abuts against the thermal head and moves it in a direction away from the platen roller; and an eccentric cam that idles when the platen roller rotates in the forward direction and reverses the platen roller. A heat transfer characterized by having a one-way clutch that rotates in the same direction when rotating. Head-up mechanism of the printer. 2. The thermal head is separated from the platen roller when the thermal head is located in a blank area portion located between the print area portions of the print medium in the transport direction of the print medium. A head-up mechanism for a thermal transfer printer according to claim 1, wherein: 3. The head-up mechanism for a thermal transfer printer according to claim 1, wherein the thermal head is separated from the platen roller by rotating the eccentric cam a half turn when the platen roller rotates in a reverse direction. 4. The head-up mechanism for a thermal transfer printer according to claim 1, wherein only the print medium can be transferred in a state where the thermal head is separated from the platen roller. 5. A head-up mechanism for a thermal transfer printer according to claim 1, further comprising a transfer mechanism capable of transferring the print medium in synchronization with the print mechanism. 6. The head-up mechanism of the thermal transfer printer according to claim 5, further comprising a single drive motor for driving the printing mechanism and the transfer mechanism. 7. The thermal transfer according to claim 1, wherein the thermal head is brought into contact with the platen roller by rotating the eccentric cam a half turn in a state where the thermal head is separated from the platen roller. Printer head-up mechanism. 8. A head-up mechanism for a thermal transfer printer according to claim 1, wherein the thermal head is opened and rotated around a head fulcrum shaft by the eccentric cam. 9. A return spring for urging the thermal head toward the platen roller is provided, and the eccentric cam separates the thermal head from the platen roller against the urging force of the return spring. The head-up mechanism for a thermal transfer printer according to claim 1, wherein the head-up mechanism is a thermal transfer printer.