JPH07137393A - Thermal head driving mechanism in thermal transfer printer - Google Patents

Abstract

PURPOSE:To compact a device and smooth the replacing work of a thermal transfer ribbon by a method wherein respective multistage operations, such as the waiting of a thermal head, pressing upon printing, opening upon replacing the thermal transfer ribbon and the like in a thermal printer, are permitted to be operated by one set of rotary driving source. CONSTITUTION:A thermal head driving mechanism is provided with one set of rotary driving source PM, an eccentric roller 26, provided at a position eccentric to the rotary shaft 16 of the rotary driving source PM and rotated into the same direction as the rotary shaft 16, and a connecting lever 28, having a long hole 30, with which a roller 26 is engaged so as to be slidable. Further, the mechanism is provided with an up-and-down moving lever 32, having a thermal head 12 at the lower surface of the tip end connected to the lever 28 and moving the thermal head 12 about a supporting shaft 36, a rotary disc 18, having a detecting unit attached to a rotary shaft 16, and a plurality of detecting means PH1, PH2, arranged at predetermined positions and detecting the detecting unit. The thermal head 12 can be operated up-and-down in multiple stages by the rotating operation of the rotary driving source PM.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving mechanism for performing multi-step operations such as a standby state, a pressure state, and an open state of a thermal head in a thermal transfer printing apparatus.

[0002]

2. Description of the Related Art Thermal heads for thermal transfer printing are
From the platen to the normal position where it stands by slightly separated from the platen until there is a print instruction signal, the pressure position where it presses against the platen when there is a print instruction signal, and the platen when replacing the thermal transfer ribbon. There is an open position that keeps them apart.

The conventional drive means for operating the thermal head in the normal position and the pressurizing position is operated by using one drive source, for example, a motor or a solenoid, while the drive means in the open position is operated by another drive source. Drive means, for example, a solenoid is used, or it is manually operated via a lever.

[0004]

That is, since the drive means for the standby position and the pressurizing position of the thermal head and the drive means for the open position are separate drive sources,
As a result, the size of the entire device increases, and the cost increases. Also, since the open state when the thermal transfer ribbon was replaced was manually performed, it is possible to forget to change the thermal head from the open state to the set state, which is the standby state.In this case, set the thermal head again. It has a problem that it has to be done.

The present invention has been made in view of the above-mentioned problems, and it is cheap and inexpensive because each operation of the thermal head in the thermal transfer printing apparatus can be operated by a drive source such as one motor. It is an object of the present invention to provide a thermal head drive mechanism in a thermal transfer printing apparatus that is compact as a whole and that can smoothly replace a thermal transfer ribbon.

[0006]

According to the present invention, the above-mentioned problem is solved by one rotary drive source (PM) and the rotary drive source (P).
M) has an eccentric roller (26) provided at a position eccentric to the rotary shaft (16) and rotating in the same direction as the rotary shaft direction, and an elongated hole (30) into which the eccentric roller (26) is slidably fitted. Vertical movement in which the thermal head (12) moves up and down around the support shaft (36) having the connecting lever (28) and the thermal head (12) connected to the connecting lever (28) on the lower surface of the tip end. A lever (32), a rotary plate to be detected (18) attached to the rotary shaft (16) and having a detection part, and a plurality of detection means (PH1, PH2) arranged at predetermined positions for detecting the detection part. And the rotary drive source (P
The thermal head driving mechanism in the thermal transfer printing apparatus is configured such that the thermal head (12) is moved up and down in multiple stages from the rotating operation of M).

A pulse motor is preferably used as the rotary drive source (PM), but the present invention is not limited to this, and any motor may be used as long as it is a rotary motor.

As the detection part of the detected rotary plate (18), a notch (20) cut out at a predetermined distance in the circumferential part, a slit (22) elongated and cut out, etc. are formed. If it is, manufacturing is simple and preferable, but
In addition to this, for example, a magnetic material may be provided in that portion, or other means may be used.

The plurality of detecting means (PH1, PH2)
For the detection of slits and the like, a transmissive photosensor may be used, and when the detection unit is a magnetic material, a magnetic detector may be used.

[0010]

The eccentric roller (26) is slidably fitted by the rotation of the eccentric roller (26) provided at a position eccentric to the rotation axis of the pulse motor (PM) which is the rotational drive source. Connecting lever (2) having a long hole (30)
8) and a vertical movement lever (32) having a support shaft (36) so that the thermal head (12) attached to the lower surface of the tip of the vertical movement lever (32) is moved up and down in multiple steps. , The open state of the thermal head (12) is also automated by one of the pulse motors (PM),
The ribbon cassette (38) can be replaced smoothly.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to an embodiment shown in the drawings. FIG. 1 is a schematic view of a thermal head drive mechanism (10) in a thermal transfer printing apparatus, showing a standby position in which a thermal head (12) is slightly separated from a platen (14).

(PM) is a rotary drive source, and a pulse motor is shown in this embodiment, but the present invention is not limited to the pulse motor. As shown in FIG. 2, a rotating plate (18) to be detected is connected to the rotating shaft (16) of the pulse motor (PM) so as to rotate with the rotating shaft (16).

The rotary plate to be detected (18) has a disk shape as shown in detail in FIG. 3, and a notch (20) is cut out at a predetermined distance on the circumference thereof. And a slit (22) which is cut out in a long and thin shape is formed at a predetermined position.

Further, a split plate (24) is attached to the rotary shaft (16) of the pulse motor (PM), and an eccentric roller (26) is rotatably provided at one end of the split plate (24).
Is installed. That is, the eccentric roller (26)
Is arranged at a position eccentric with respect to the rotating shaft (16), and rotates around the rotating shaft (16) via a split plate (24) as the rotating shaft (16) rotates. It is supposed to do.

Reference numeral (28) is a plate-like connecting lever, and as shown in detail in FIG. 4, an elongated hole (30) is formed from one side toward the central portion side. The eccentric roller (26) is slidably fitted in the elongated hole (30). Also, the connecting lever (28) on the side opposite to the long hole (30)
An up-and-down moving lever (32) is fixed to the shaft by a screw (34).

The vertical movement lever (32) has a support shaft (36) at substantially the center thereof and is rotatable about the support shaft (36), and a connecting lever (28). The end on the opposite side moves up and down. The thermal head (12) is attached to the lower part of the end of the vertical movement lever (32).

(PH1) and (PH2) are notches (20) or slits (22) of the detected rotary plate (18).
These are a first detection means and a second detection means for detecting the like. Both of these detecting means use a transmissive photosensor in this embodiment.

(38) is a ribbon for thermal transfer, and (4)
0) is the printing tape. (42, 42) are pinch rollers for guiding the printing tape (40).

Next, the operation of the thermal head (12) shown in FIG. 1 from the standby position state to the pressurizing state during printing will be described with reference to FIGS. 5 and 7.

First, in the standby position shown in FIG. 1, the slit (22) of the rotary plate (18) to be detected is in the upper position, and the first detecting means (PH1) has the slit (22).
Is detected and the state is turned ON, and the cutout portion (20) of the detected rotary plate (18) is detected by the second detecting means (PH2), and the second detecting means (PH2).
Is also ON.

In this state, when a print signal is input, a positive drive pulse (P) is applied to the pulse motor (PM).
1) is input, the pulse motor (PM) is rotated clockwise (clockwise) from the state of FIG. 1, the eccentric roller (26) also rotates clockwise, and the eccentric roller (26) rotates the connecting lever (28). The rear end side is lifted and the vertical movement lever (3
The tip end side of 2) is lowered by rotating around the support shaft (36), and the surface of the thermal head (12) contacts the platen (14) and is pressed. At this time, the rotary plate to be detected (18) also rotates clockwise, the first detecting means (PH1) is shielded (closed) and brought into the OFF state, and the second detecting means (PH2) is notched as described above. Department (2
It is in the ON state when 0) is detected (open). This is the pressurized state of the thermal head (12),
In this pressurizing state, the eccentric roller (26) is in a state right above, which is the top dead center.

When a print end signal is input from this pressurizing state, a reverse pulse (P2) is input to the pulse motor (PM) as shown in FIG. 7, and the pulse motor (PM) is input.
Is in reverse rotation, and the thermal head (12) is in a stand-by state with the head up as shown in FIG. Then, the standby state and the pressurizing state are repeated.

Next, the thermal head (12) shown in FIG.
The operation from the standby position to the open position when replacing the thermal transfer ribbon (38) will be described with reference to FIGS. 6 and 8.

From the standby position in FIG. 1, the cassette ribbon (3
When a signal for opening the thermal head (12) is input to replace 8), the pulse motor (PM)
8 is applied, the detected rotary plate (18) rotates clockwise (clockwise) by a predetermined angle.

Then, the first detecting means (PH1) is temporarily closed (closed) by the detected rotary plate (18), and thereafter the first detecting means (PH1) is notched as shown in FIG. When the section (20) is detected, it becomes an open state (energized state) and is turned on. This first detection means (PH1)
The pulse motor (PM) stops its rotation upon detection of the ON state of. During this rotation, the second detection means (PH
Although 2) detects the slit (22), it is shielded (closed) by the detected rotary plate (18) after that, and is turned off.

The movement of the thermal head (12) is as follows.
With the rotation of the pulse motor (PM), the eccentric roller (26) rotates clockwise from the state shown in FIG. 1, and once the eccentric roller (26) rises to the thermal head (12).
Is pressed by the platen (14), but after that, the rear end side of the connecting lever (28) is pushed down, so that the tip end side of the vertical movement lever (32) rises around the support shaft (36). Then, as shown in FIG. 6, the thermal head (1
2) is in the open position away from the platen (14). In this state, the thermal transfer ribbon (38) is replaced.

As described above, when the thermal transfer ribbon (38) is exchanged by opening the thermal head (12) shown in FIG. 6 and then a thermal headset signal is input by a push button switch or the like, as shown in FIG. (P
M) receives an input signal, the pulse motor (PM) is rotated clockwise (clockwise) by a predetermined angle, the first detection means (PH1) shown in FIG. 1 detects the slit (22), and
The second detection means (PH2) stops the rotation of the pulse motor (PM) by detecting the cutout portion (20).

In this embodiment, the operation of the thermal head (12) has three stages as the standby position, the pressurizing position and the open position. However, the thermal head (12) is further released from the open position and the platens (14) to (14). May make it easier to clean the thermal head (12).
Needless to say, the operation may be performed in multiple stages. In that case, the number of photosensors may be increased appropriately.

[0029]

As described above, according to the present invention, 1
The position of the thermal head for thermal transfer printing can be automatically adjusted with respect to the platen in multiple stages with two rotary drive sources, so it can be easily opened and replacement of the thermal transfer ribbon is difficult. It can be done smoothly and work efficiency is improved. Further, since there is only one rotary drive source, the device itself becomes compact and the cost is low.

[Brief description of drawings]

FIG. 1 is a schematic view of a drive mechanism showing a standby state of a thermal head.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a front view showing a detected rotary plate.

FIG. 4 is a front view showing a connecting lever.

FIG. 5 is a schematic view of a drive mechanism showing a pressed state of a thermal head.

FIG. 6 is a schematic view of a drive mechanism showing an open state of a thermal head.

FIG. 7 is a diagram showing a timing chart of the operation of the thermal head from the standby state to the pressurizing state and from the pressurizing state to the standby state.

FIG. 8: From the standby state of the thermal head to the open state,
FIG. 9 is a diagram showing a timing chart of the operation from the open state to the standby state.

[Explanation of symbols]

 10 Thermal Head Driving Mechanism 12 Thermal Head 14 Platen 16 Rotating Shaft 18 Rotating Plate to be Detected 20 Notch 22 Slit 26 Eccentric Roller 28 Connecting Lever 30 Long Hole 32 Vertical Lever 36 Spindle PM Pulse Motor PH1 First Detection Means PH2 No. 2 detection means

Claims (4)

[Claims] 1. A rotary drive source (PM), and an eccentric roller (26) provided at a position eccentric to a rotary shaft (16) of the rotary drive source (PM) and rotating in the same direction as the rotary shaft direction. An elongated hole (30) into which the eccentric roller (26) is slidably fitted
And a connecting lever (28) having the
And a thermal head (12) on the lower surface of the tip end of the thermal head (12) centered on the spindle (36).
A vertical movement lever (32) that moves up and down, and the rotary shaft (1
Detected rotary plate (18) attached to 6) and having a detection unit
And a plurality of detecting means (PH1, PH2) for detecting the detecting portion and arranged at a predetermined position, and the thermal head (12) is moved up and down in multiple stages from the rotation operation of the rotary drive source (PM). A thermal head drive mechanism in a thermal transfer printing apparatus, which is characterized in that 2. The thermal head drive mechanism in the thermal transfer printing apparatus according to claim 1, wherein the rotary drive source (PM) is a pulse motor. 3. A notch portion (2) in which the detecting portion of the detected rotary plate (18) is notched at a predetermined distance in its circumferential portion.
0) and a slit (22) which is elongated and cut out, and the thermal head drive mechanism in the thermal transfer printing apparatus according to claim 1. 4. The plurality of detection means (PH1, PH2)
2. The thermal head drive mechanism in the thermal transfer printing apparatus according to claim 1, wherein each of them comprises a transmissive photo sensor.