JP2898485B2 - Thermal transfer printer - Google Patents

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,
In particular, the present invention relates to a thermal transfer printer in which an up-down operation of a thermal head and a winding operation of an ink ribbon are controlled by one driving source.

[0002]

2. Description of the Related Art In general, in a thermal transfer printer in which an ink ribbon cassette containing a thermal transfer ink ribbon is mounted on a carriage and the carriage is reciprocated along a platen to perform printing, the ink ribbon is wound in accordance with the movement of the carriage. The ink ribbon needs to be taken up and down in conjunction with the up and down movement of the thermal head.

A conventional thermal transfer printer will be described below with reference to the drawings.

FIGS. 3 and 4 are configuration diagrams showing an example of a conventional thermal transfer printer. In the figure, 1 is a carriage,
2 is a thermal head mounted on the carriage 1, 3 is an ink ribbon cassette containing an ink ribbon, 4 is a shaft arranged parallel to the platen 5 and slidably holds the carriage 1, and 6 is parallel to the shaft 4. Is a rack member having rack teeth formed thereon, which is engaged with the rack teeth of the rack member 7 when the head is down, and transmits the ink ribbon to the reel in the ink ribbon cassette 3 with the movement of the carriage 1. Gear. Reference numeral 8 denotes a paper feed roller for feeding paper, and reference numerals 9 and 10 denote small rollers pressed against the paper feed roller 8.

The carriage 1 is configured to be rotatable about a shaft 4 and is driven by a solenoid (not shown) to bring the thermal head 2 into pressure contact with the platen 5, that is, a so-called head-down state (FIG. 3). . At this time, since the transmission gear 7 meshes with the rack teeth of the rack member 6, the transmission gear 7 rotates with the movement of the carriage 1, and further, the ink ribbon take-up reel of the ink ribbon cassette 3 rotates via a transmission mechanism (not shown). The ink ribbon is wound.

FIG. 4 shows a head-up state, that is, a state in which the thermal head 2 is separated from the platen 5, but as shown, the transmission gear 7 is separated from the rack teeth of the rack member 6 in this state. Since the transmission gear 7 is not rotated by the movement of the carriage 1, the ink ribbon is not wound up.

As described above, by rotating the carriage 1, the head is moved up and down to control the printing and the winding of the ink ribbon.

[0008]

In the conventional thermal transfer printer as described above, the head up / down operation is controlled by rotating the carriage 1, so that a driving source (solenoid or the like) for this purpose is driven by a driving force. A large device is required, and there has been a problem that the device becomes large and power consumption increases.

Further, when the transmission gear 7 engages with the rack teeth of the rack member 6 during the head-down operation, backlash occurs between the teeth of the transmission gear 7 and the rack teeth, so that the initial movement of the carriage 1 at the time of movement is performed. However, there is also a problem that the ink ribbon is not wound up, and a blank printing area for winding up the slack of the ink ribbon caused by printing becomes long.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a thermal head mounted thereon.
And a reciprocating carriage along the platen
Moving the thermal head toward and away from the platen
The head press-contact lever and the ink ribbon
Transmission gear that selectively transmits torque to the winding bobbin.
And a rocking plate with
A cam for driving the contact lever and the swing plate is provided, and the head down
In the printer state, the ink
While the head is in the up position.
Heat transfer not to take up the ink ribbon
In the copying printer, the transmission gear is moved down by a head.
The winding gear that drives the winding bobbin during operation
The take-up gear is provided so as to mesh with the direction in which the take- up gear rotates in the ink ribbon take-up direction.

[0011]

The above means operates as follows. When the transmission gear meshes with the take-up gear in conjunction with the head-down operation, the take-up gear is slightly rotated in the direction in which the ink ribbon is taken up, so that backlash between the gears is absorbed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A thermal transfer printer according to the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are diagrams showing the configuration of an embodiment of the present invention. FIG. 1 shows a head down state and FIG. 2 shows a head up state. As shown in the figure, a carriage 4 reciprocally movable along the platen 1 is provided with a motor 4 for controlling the operation of moving the thermal head 3 to and from the platen 1 and controlling the winding of the ink ribbon. A transmission gear 6 is meshed with the output pinion gear 5 of the motor 4. A gear portion 8 formed on the outer peripheral surface of a cam 7 is meshed with the transmission gear 6, and a cam groove 9 for head contact / separation and a cam groove 10 for ribbon winding are formed on the upper surface of the cam 7.
Are formed respectively.

Reference numeral 11 denotes a substantially L-shaped head pressure lever.
A pin 13 is formed at one end of the head pressure contact lever 11 so as to be swingable about a shaft 12.
The cam 7 is engaged with the head contact / separation cam groove 9.
The other end of the head pressure lever 11 is connected to the thermal head 3
The platen 1 of the thermal head 3 is brought into contact with the back surface of the head mounting base 3a via a spring (not shown) by the rotation of the head press-contact lever 11 accompanying the rotation of the cam 7.
Is performed. Further, a lever 14 is connected to the other end of the head press-contact lever 11, and this lever 14 is interlocked with the head press-contact lever 11.

The carriage 2 has a drive gear 16 which always meshes with a rack 15 formed on the printer.
The swinging plate 18 that constitutes a transmission mechanism of the winding force of the ink ribbon is attached to the support shaft 17 so as to be swingable about the support shaft 17. A pin 19 is formed at one end of the rocking plate 18 to be engaged with the cam groove 10 for winding the ribbon of the cam 7. A transmission gear 20 meshed with the drive gear 16 is rotatably attached to the other end of the swing plate 18.

A carriage bobbin 21 and a delivery bobbin (not shown) for the ink ribbon are provided on the carriage 2, and can be engaged with the transmission gear 20 below the take-up bobbin 21. The take-up gear 23 is coaxially mounted via a friction mechanism (not shown).

Further, in the present embodiment, the carriage 2 is provided with a second take-up bobbin 24 and a second delivery bobbin 25, respectively.
A second take-up gear 27 that meshes with the take-up gear 23 of the take-up bobbin 21 via a transmission gear 26 is coaxially attached to the bottom of the take-up bobbin 21 via a friction mechanism (not shown). The winding bobbin 21 and the second winding bobbin 24
The transmission gear 20 is rotated by the rotation of the cam 7 and the transmission gear 20 meshing with the winding gear 23 in conjunction with the down operation of the thermal head 3.

Further, a take-up spring 28 composed of a leaf spring is attached to the tip of the lever 14 connected to the head pressure contact lever 11, and the tip 27a is
When the thermal head 3 is in the down state, the transmission gear 2
6 is engaged with the teeth of the transmission gear 26 when the thermal head 3 is in the up state.

Next, the operation of this embodiment will be described.

First, as shown in FIG. 1, since the pin 13 of the head pressure contact lever 11 is located at the innermost periphery of the head contact / separation cam groove 9 of the cam 7, the head pressure contact lever 11 is moved to the leftmost position. The head mounting base operates together with the head pressure contact lever 11 because of the swinging state.
Is held in a state of being pressed against the platen 1, a so-called head-down state. In this state, the pin 19 of the swing plate 18
Is located at the outermost periphery of the cam groove 10 for winding the ribbon,
The swing plate 18 is in a state of being swung to the left most, and the transmission gear 20 is in a state of being meshed with the winding gear 23. In this state, when the carriage 2 moves along the platen 1 to rotate the drive gear 20 meshed with the rack, the take-up gear 23 is transmitted via the transmission gears 20 and 26.
Then, the second winding gear 27 rotates, and the operation of winding the ink ribbon is performed. As described above, in this state, the take-up spring 28 is held at a position away from the transmission gear 26.

Next, as shown in FIG. 2, the motor 4 is driven from the state shown in FIG.
When the cam 7 is rotated such that the pin 13 is located at the outermost periphery of the cam groove 9 for head contact / separation, the head pressure contact lever 11 swings rightward, and the thermal head 3 is detached from the platen 1 accordingly. (Head-up state). Further, since the pin 19 of the swinging plate 18 is located at the innermost circumference of the cam groove 10 for winding the ribbon, the swinging plate 18 also swings rightward, and the engagement between the transmission gear 20 and the winding gear 23 is released. The transmission gear 20 is held at a position separated from the winding gear 23. In the operation from the state shown in FIG. 1 to FIG. 2, that is, in the up operation, the lever 14 moves in conjunction with the movement of the head pressure lever 11, so that the winding spring 28 attached to the lever 14 performs the up operation. The transmission gear 26 is rotated in the direction in which the ink ribbon is wound by a further up operation. The rotation of the transmission gear 26 is controlled by the winding gear 23.
Is transmitted to the second take-up gear 27, and the slack of the ink ribbon caused by the thermal head 3 being separated from the platen 1 is taken up.

Therefore, even if new paper is inserted in this state, the ink ribbon does not slack, so that the leading end of the paper does not catch the ink ribbon. In the head-up state shown in FIG. 2, since the transmission gear 20 is separated from the winding gear 23, even if the carriage 2 is moved along the platen 1 in this state, winding of the ink ribbon is performed. Not.

When the next printing is performed from the state shown in FIG. 2, the motor 4 is driven to select a predetermined position of the cam 7 so that the state shown in FIG. 1 is obtained. The transmission gear 20 meshes with the take-up gear 23 due to the swinging motion of the moving plate 18, but the direction of this meshing is the direction of rotating the take-up gear 23 in the direction of winding the ink ribbon. Slightly rotate in the ink ribbon winding direction and mesh with each other. Therefore, backlash between these gears does not occur in the ink ribbon winding direction.

Next, carriage movement and printing are performed.
At this time, since the slack of the ink ribbon has not already occurred, it is not necessary to transfer the carriage in a blank printing state to remove the slack and absorb the backlash between the gears. At the same time, it is necessary to carry out empty printing only in the through-up area for keeping the speed of the carriage constant.

[0025]

As described above, in the present invention,
Equipped with a thermal head, it can reciprocate freely along the platen
The thermal head on the carriage
Head pressure contact lever and ink that move to and away from the ten
Selectively apply rotational force to the winding bobbin that winds the ribbon
A rocking plate with a transmission gear for transmitting
In addition, the power for driving these head pressure levers and the rocking plate
A driving force of the carriage in the head down state.
To take up the ink ribbon using
In the head-up state, take up the ink ribbon.
In the thermal transfer printer, the transmission gear
Drive the take-up bobbin during head-down operation.
This winding gear is used for winding the ink ribbon.
Since the gears are arranged so as to mesh with each other from the direction of rotation, backlash does not occur between the transmission gear and the take-up gear at the time of head down operation. Do we, for idle feeding operation for absorbing the backlash is not required, bring down the head it is possible to shorten the distance until the start of printing from, can reduce the width of the printer as a result, that It has excellent effects.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a main part showing an embodiment of a thermal transfer printer of the present invention, showing a head down state.

FIG. 2 is a configuration diagram of a main part showing one embodiment of the thermal transfer printer of the present invention, showing a head-up state.

FIG. 3 is a configuration diagram of a main part of a conventional thermal transfer printer, showing a head down state.

FIG. 4 is a configuration diagram of a main part of a conventional thermal transfer printer, showing a head-up state.

[Explanation of symbols]

 Reference Signs List 2 carriage 3 thermal head 4 motor 7 cam 11 head pressure contact lever 14 lever 18 rocking plate 20 transmission gear 23 winding gear 26 transmission gear 27 second winding gear 28 winding spring

Claims (1)

(57) [Claims] 1. A thermal head mounted on a platen,
The above-mentioned thermal head
Pressure contact for moving the pad to and away from the platen
Select the take-up bobbin that takes up the lever and ink ribbon.
And a rocking plate having a transmission gear for selectively transmitting rotational force.
The head press-contact lever and swing plate
A cam for driving the provided winding operation of the ink ribbon in together when performing the winding operation of the ink ribbon by using a driving force of the carry <br/> Tsu di in the head-down state in F Tsu door-up state In the thermal transfer printer in which the transfer gear is not performed, the transfer gear is wound during the head-down operation.
Ink The winding gear to the take-up gear for driving the bobbin
A thermal transfer printer, wherein the thermal transfer printer is provided so as to be engaged with a direction rotating in a ribbon winding direction.