JPS6248595B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal transfer printing device, and more particularly to a thermal transfer printing device in which the drive system of the carriage, thermal head, and ink ribbon of the thermal transfer printing device is improved.

The principle of a thermal transfer printing device is shown in FIG. 1. A printing paper 3 is placed between a thermal head 1 and a platen 2, and a thermal transfer ink ribbon 4 is placed between the printing paper 3 and the thermal head 1. place,
Printing is performed by sending a print signal to the thermal head 1 at a predetermined printing position while moving the thermal head 1 in the direction indicated by arrow A in FIG.

As shown in FIG. 2, the thermal head 1 has a plurality of heating resistors 6, for example seven in a vertical line, mounted on a substrate 5 made of ceramic or the like, and these heating resistors 6 are energized according to a predetermined printing program. By making a predetermined heating resistor 6 generate heat, the heat-melting ink 4b coded on the printing paper 3 side of the base 4a of the thermal transfer ink ribbon (hereinafter simply referred to as ink ribbon) 4 is combed, and the printing paper 3 is melted. Desired characters or symbols are transferred onto it in a dot pattern.

In a thermal transfer printing device having such a structure, the thermal head 1 and the ink ribbon 4 are mounted on a carriage (not shown), and are pressed against the printing paper 3 with a constant pressure via the ink ribbon 4. It has a structure that moves from side to side. Therefore, a relative speed is generated between the printing paper 3 and the ink ribbon, resulting in the ink ribbon moving while rubbing against the printing paper. of course,
It is possible to consider a method in which the ink ribbon is removed from the printing paper until a printing command is received, but if such a method is adopted, the ink ribbon is pressed and then the heating resistor of the thermal head is energized, which reduces the printing speed. is significantly reduced, making it impractical.

As described above, when the ink ribbon 4 is rubbed and moved along the printing paper 3, the heat-melting ink 4
In b, since the ink contains fine particles in the binder that dissolves when heated, these particles adhere to the printing paper 3, staining the printing paper and significantly reducing the print quality.

The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and an object of the present invention is to provide a thermal transfer printing device configured so that the head and carriage can be moved without staining the printing paper.

In the present invention, in order to achieve the above object, the ink ribbon is moved in the opposite direction to the movement direction at the same speed as the movement and speed of the thermal head and the carriage, and in the case of carriage return, the ink ribbon is printed. We adopted a method in which it is released from paper.

Hereinafter, details of the present invention will be explained based on embodiments shown in the drawings.

Figure 3 and subsequent figures show an embodiment of the present invention.
In the figure, the symbol 10 is a carriage.
One end of the carriage 10 is slidably fitted through an arm 10a to a guide shaft 11 horizontally suspended on the printer side, and the lower surface of the carriage 10 is slidably guided by a guide rail 12. Carriage 1
An arm 14 is connected to a part of the arm 10a of 0 through the shaft 13.
The lower end of is rotatably supported. A thermal head 15 is attached to the upper end of the arm 14 on the side facing a platen, which will be described later.

For example, a stepping motor 16 for driving the ink ribbon is attached to the lower surface of the carriage 10, and a shaft 19 for driving the ink ribbon is connected via a gear 17 fixed to the output shaft of the stepping motor 16 and a gear 18 meshing with the gear 17. Rotate the ink ribbon to run freely. This stepping motor 16 naturally acts together with the carriage 10.

On the other hand, a drive motor 21 for the carriage 10 is fixed on the printer side via a bracket 20, and a pinion gear 22 is fixed to the output shaft of the motor 21 for driving the carriage 10.
meshes with a gear 23, and a pulley 24 is fixed to this gear 23. Corresponding to this pulley 24, another pulley (not shown) is provided on the printer side, and a drive belt 25 is stretched between these pulleys. This drive belt 25 is formed endlessly, and a part of the arm 10a of the carriage 10 is fixed to a part of it via a connector 26, and when the belt 25 is operated by the motor 21, Therefore, the carriage 10 is configured to move.

Ink ribbon cassette 2 is placed on the carriage 10.
7 can be detachably attached. The details of this ink ribbon cassette 27 will be described later.

A platen 28 is horizontally suspended opposite the carriage 10, a paper guide 29 is provided surrounding the platen 28, and a printing paper 30 is inserted between the paper guide 29 and the platen 28. The paper guide 29 is attached to a rotating arm 31, which is rotatably supported on a shaft 32, and supported by a spring 33 stretched between one end thereof and the bracket 20 side. Therefore, in FIG. 3, a counterclockwise rotational habit is given. A pinch roller 34 is attached to the rotating arm 31, and the printing paper 30 is guided to a position facing the thermal head 15 by the pinch roller 34.

Further, as shown in FIG. 4, a solenoid 35 is attached near the arm 14, and when the solenoid 35 is energized during printing operation, its plunger moves forward, causing the arm 14 to move clockwise in FIG. direction, and press the thermal head 15 against the platen 28 side.

Figure 5 shows a plan view of the printer, and in Figure 5, the carriage 10 is shown moving to the left end and right end at the same time, but in reality there is only one carriage. . Further, in FIG. 5, the ink ribbon cassette 27 is not attached to the carriage 10 that has moved to the left end, but the ink ribbon cassette 27 is attached to the carriage that has moved to the right end.

During printing, the carriage 10 holds the thermal head 15, the ink ribbon cassette 27, and their driving members while pressing against the thermal head 15 and the platen 28, and moves in parallel with the platen 28 as directed by the guide shaft 11 and guide rail 12. Move in direction B.

FIG. 6 shows a cross-sectional view of the ink ribbon cassette, and in the figure, reference numeral 27a is a cassette case;
An ink ribbon take-up reel 36 and a supply reel 37 are attached to this cassette case, and the ink ribbon 38 unwound from the supply reel is attached to guide rollers 39 to 42 and guided to the take-up reel 36. There is. Cassette case 27
An opening 27b is formed at the tip of a.
The ink ribbon 38 is guided to pass through the open end side of the opening 27b, and the ink ribbon cassette 27
When mounted on the carriage 10, the thermal head 15 is fitted into this opening 27b.
The cassette case 27a also has two reels 36,
A drive roller 43 is provided near the cassette case 37, and guide rollers 44, 45 are provided at both ends of the cassette case 27a, and a drive belt 46 for the ink ribbon is stretched around these rollers. The drive belt 46 is elastically in contact with the ink ribbon 38 wound around the take-up reel 36 and the supply reel 37. This drive roller 4
3 is rotated by a shaft 19 to which the driving force from the stepping motor 16 is transmitted, and as the drive belt 44 runs, the ink ribbon 38 is sent out.

Next, the operation of this embodiment configured as above will be explained with reference to the timing chart shown in FIG.

First, when print data is input from a control device (not shown) to the drive device on the printer side and printing preparation is completed, the carriage 10 starts to be driven in the direction of arrow B from the left end shown in FIG. The head 15 is pressed through the ink ribbon 38 against the platen 28 and the printing paper 30 located on its outer periphery.

By the way, the motor 21 for driving the carriage 10
As shown in FIG. 3, an encoder 47 is attached to the printer, and this encoder 47 generates a timing pulse shown by reference numeral 100 in FIG. 16 drive pulses and a speed control signal for the carriage drive motor 21.

Therefore, after the movement of the carriage 10 is started and accelerated as described above, the ink ribbon 38 is started to be driven and the thermal head is pressed at the same time at the timings 120 and 130 shown in FIG. 38 is moved at the same speed as the carriage moving direction in the opposite direction, that is, in the direction shown by arrow C in FIG. 38 drive is code 120
As shown in , since the speed is not instantaneously stable, a relative speed occurs between the ink ribbon 38 and the printing paper 30, and the printing paper becomes smudged.

Therefore, in the present invention, as shown in FIG. 8, when a print command is issued, the timing signal of the encoder 47 is sent to the drive circuit CD of the carriage 10 via the AND gate AG1.
is applied to drive the carriage 10, and the timing signal of the AND gate AG is delayed by a delay circuit D1 for a predetermined time and is applied to the drive circuit ID of the ink ribbon feed motor to drive the ink ribbon. After the drive of the ink ribbon is started and the ink ribbon feed is stabilized, the thermal head is pressed against the printing paper, as shown by reference numeral 131 in FIG. The head drive circuit HD is driven with a delay of _T1 by the delay circuit D1 to press the head.

On the other hand, in order to increase the printing speed, when the carriage drive motor 21 is rapidly accelerated, the rotation of the motor is reduced as shown by reference numeral 110 in FIG.
Overshoot by O ₁ . Here, as shown by reference numeral 121 in FIG. 7, the stepping motor 16 for driving the ink ribbon is started at the same time as the motor 21 for driving the carriage.
If the overshoot amount of is higher than _O2 , it will exceed the response speed of the stepping motor 16,
The ink ribbon 38 ends up stopping.

Therefore, if the pressing operation of the thermal head 15 is started as indicated by reference numeral 132 at the same time as the drive of the carriage 10 is started, the head will be pressed while the ink ribbon feeding is stopped and the printing paper will be smeared.

In order to solve this problem, even if the ink ribbon 38 is started to be driven at the same time as the carriage 10 as shown by reference numeral 131 in FIG. A method is adopted in which the speed is delayed by the delay circuit D4 by the time _T2 required to reach a constant speed.
Even if the ink ribbon is started to be driven at the same time as the carriage starts to be driven, the ink ribbon feeding speed corresponding to the carriage speed will not be stabilized. As shown, the ink ribbon drive start timing is shifted by _T3 , which is the difference between _T2 and _T1 , by a delay circuit D3.

FIG. 9 is a block diagram for carrying out the above-mentioned control. In the figure, AG1 is an AND gate which is opened in response to a print command and gates the timing pulse from the encoder 47. This pulse is applied to the carriage drive circuit CD1 to drive the carriage drive motor 21. The head has a delay circuit D4 to delay its drive by _T2 hours from when the carriage is driven.
It receives a signal via the drive circuit HD1 and is driven by the drive circuit HD1. On the other hand, the ink ribbon is caused by delay circuit D3.
It receives a signal after a delay of T ₃ hours and is driven by the drive circuit ID1. If the time relationship T ₂ -T ₃ =T1 is established here, the embodiment shown in FIG. 8 can also be included.

In this way, a thermal transfer printing device is obtained in which the printing paper is not stained by the ink ribbon.

In the case of carriage return, the carriage returns in the direction of arrow D in FIG. Does not stain printing paper.

By the way, in the above embodiment, the carriage 1
In this example, a DC servo motor is used to drive the ink ribbon, and a stepping motor is used to drive the ink ribbon. Exactly the same configuration can be adopted since utes and disturbances occur.

Furthermore, even if another motor such as a servo motor is used to drive the ink ribbon, the system will have at least a first-order delay with respect to the start-up of the carriage, and there will be a delay between the ink ribbon and the printing paper after the ink ribbon starts driving. Since relative speed occurs during a certain period of time, the inconvenience can be solved by adopting exactly the same configuration.

As is clear from the above description, according to the present invention, the printing operation is performed while feeding the ink ribbon at the same speed as the moving speed of the carriage equipped with the thermal head, and in the opposite direction to the moving direction of the carriage, and the carriage return In some cases, the ink ribbon moves with the thermal head releasing its pressure on the print paper, so the ink ribbon does not rub against the print paper, resulting in extremely high print quality and thermal transfer printing that does not stain the print paper at all. equipment can be provided.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the basic structure of a thermal transfer printing device, Fig. 2 is an explanatory diagram showing an example of a thermal head, and Figs. 3 to 7 are explanatory diagrams showing an embodiment of the present invention. Figure 3 is a left side view of the printer; Figure 4 is a left side view of the printer;
The figure is a right side view of the printer, FIG. 5 is a plan view of the printer, FIG. 6 is a cross-sectional plan view of the ink ribbon cassette, FIG. 7 is a timing chart, and FIGS. 8 and 9 are blocks explaining the drive circuit. It is a diagram. 10... Carriage, 11... Guide shaft, 15... Thermal head, 16... Stepping motor, 21
...carriage drive motor, 25...drive belt,
28...platen, 30...print paper, 38...ink ribbon.

Claims (1)

[Scope of Claims] 1. A thermal head and a thermal transfer ink ribbon cassette are provided on a carriage driven by a motor, and during printing, the thermal head is attached to a platen facing the thermal head and the thermal transfer ink ribbon is guided to the printing paper. In a thermal transfer printing device that thermally transfers the heat-melting ink on the thermal transfer ribbon in a desired printing pattern by pressing the thermal transfer ribbon through The present invention is characterized in that it is provided with a motor that is driven so that the ink ribbon does not move, and a means for pressing the thermal head against the printing paper during printing, and configured to press the thermal head against the printing paper after a predetermined time delay from the start of driving of the ink ribbon. Thermal transfer printing equipment. 2. The thermal transfer printing device according to claim 1, wherein the thermal head is pressed against the printing paper after a predetermined time delay from the start of driving of the carriage. 3. The thermal transfer printing device according to claim 1, wherein driving of the ink ribbon is started a predetermined time after the start of driving of the carriage.