JPS61277479A - Thermal printer - Google Patents

Abstract

PURPOSE:To avoid wasting a thermal transfer film, by a method wherein a thermal transfer film is taken up in synchronism with the moving velocity of a carriage at the time of printing by a thermal head, and is taken up at a slower speed when returning the carriage in a non-printing condition. CONSTITUTION:When printing, the carriage 1 is moved in the direction of arrow A, a printing head 5 is pressed against a platen 6, and generates heat according to a printing signal. In this case, a gear 18 is rotated in the direction of arrow C, while a gear 19 is rotated in the direction of arrow D, and a take-up reel 9 is rotated, whereby the thermal transfer film 7 is taken up in synchronism with the moving velocity of the carriage 1 under a slip clutch action due to friction with a printing paper. When returning to a starting end, a timing belt 11 is moved in the direction of arrow F, an arm 15 is moved rightward by friction, gears 18, 20 are engaged with each other, and rotation is transmitted to the reel 9 through a gear 23, pulleys 25, 26 and a belt 27. Since the diameter of the gear 23 is larger than that of a gear 21, the transfer film is taken up by only a little amount. Accordingly, the thermal transfer film once used is not reused, and waste thereof is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thermal printer that is used in word processors, computers, etc. and uses a thermal transfer film.

BACKGROUND OF THE INVENTION Conventionally, a thermal printer using a thermal transfer film has a thermal transfer film mounted on a carriage in which a thermal head is provided.

When printing, the thermal head is pressed against the paper to be printed via the thermal transfer film, and the thermal transfer film is wound up at a speed faster than the moving speed of the carriage, and the friction between the thermal transfer film and the paper causes the thermal transfer film and the carriage to was in sync with.

Problems to be Solved by the Invention In the conventional thermal printer as described above, the thermal transfer film is kept taut while the thermal head is printing, but when the carriage is returned to the starting position of printing, the thermal transfer film remains taut. Because the head is separated from the printing paper, the thermal transfer film has some slack. If the thermal transfer film is even slightly reversed due to vibration, etc., the part that was once used for printing will be used again for printing, resulting in poor printing quality. It was getting worse.

Means for Solving the Problems The technical means for solving the above-mentioned conventional problems is to mount a thermal head on a carriage with a thermal transfer film, and when the thermal head is printing, it is synchronized with the moving speed of the carriage. The thermal transfer film is wound up at a speed slower than the moving speed when the thermal head is in a non-printing state and the carriage is being returned.

Effect With the above configuration, even if the thermal transfer film of the present invention becomes somewhat loosened when the print head returns from the printing position to the non-printing position, the thermal transfer film is wound up when the carriage is returned to the printing start edge, so that the thermal printer of the present invention can be used once. Thermal transfer film is never used again. Further, since the thermal transfer film is wound up at a slow speed at this time, the thermal transfer film is not wasted much.

Example An embodiment of the present invention will be described below.

1 is a carriage, and a pair of carriage shafts 3.
It is slidably attached to the top of 4.

Reference numeral 5 denotes a thermal head, which is attached to the carriage 1 and is provided so as to be able to come into contact with and detach from the platen 6.

A thermal transfer film 7 is unwound from a supply reel 8, passes through the surface of the thermal head 5, and is wound onto a take-up reel 9. The thermal transfer film 7, supply reel 8, and take-up reel 9 are housed in a cartridge 10 and mounted on the carriage 1.

Reference numeral 11 denotes a timing belt formed in an annular shape and having teeth on the inner surface, suspended between a pair of drive gears 12 and 13, and fixed to the carriage 1 by a fixing member 14.

Reference numeral 15 denotes an arm rotatably attached to the carriage around a shaft 16. A roller 17 is rotatably attached to the arm 15, and a gear 18 is rotatably attached to the arm 15. installed. Furthermore, the gear 18 meshes with the timing belt 11.

A gear 19 is attached to a common shaft with the take-up reel 9, and the take-up reel 9 is connected to the gear 19 via a slip clutch (not shown). moreover,
Gear 19 is provided to mesh with gear 18.

A gear 20 is rotatably attached to a shaft 21 provided on the carriage 1 and can mesh with the gear 18. Further, a gear 22 having a smaller diameter than the gear 20 and connected to the gear 20 is attached to the shaft 21.

A gear 23 is rotatably attached to a shaft 24 provided on the carriage 1 and meshes with the gear 20. Further, a pulley 25 having a smaller diameter than the gear 23 and connected to the gear 23 is attached to the shaft 24 .

The pulley 25 is the pulley 2 connected to the gear 19.
6 via a belt 27.

The above embodiment of the present invention operates as follows.

First, when printing, as shown in Figure 1, the carriage 1 is
moves in the direction of arrow A. At this time, the print head 5 is pressed against the platen 6 by a head drive device (not shown), and the print head 5 generates heat according to the print signal current.

Since the timing belt 11 moves in the direction of arrow B and the arm 15 is pushed leftward by friction, the gears 18 and 19 mesh with each other.

At this time, the gear 18 rotates in the direction of arrow C, and the gear 19 rotates in the direction of arrow C, so that the take-up reel 9 winds up the thermal transfer film 7.

Since the ink layer of the thermal transfer film 7 is transferred to the printing paper by the print head 5, there is a large friction with the printing paper (not shown) on the platen 6, and the winding speed of the thermal transfer film 7 is reduced by the action of the slip clutch. is synchronized with the moving speed of the carriage 1.

Next, when returning the carriage 1 to the printing start end, the print head 5 is separated from the platen 6 and the carriage 1 is moved in the direction of arrow E, as shown in FIG.

Then, the timing belt 11 moves in the direction of arrow F, and the arm 15 is pushed to the right by friction, so that the gears 18 and 20 mesh with each other.

Since the gears 21 and 23 are in mesh with each other, and the pulley 26 is connected to the pulley 25 via the belt 27, the rotational force of the gear 18 is transmitted to the reel 9.

Focusing on the direction of rotation at this time, gear 18 rotates in the direction of arrow G, gear 20 rotates in the direction of arrow H, gear 23 rotates in the direction of arrow ■, and gear 19 rotates in the direction of arrow R.

Since the diameter of the gear 23 is larger than the diameter of the gear 21, the take-up reel 9 rotates slowly and the thermal transfer film 7 is wound only a little.

The thermal transfer film 7 is vibrated by the above winding.
Even if the temperature returns to some extent, the thermal transfer film 7 that has been used will not be used again, and the printing quality will not deteriorate.

Effects of the Invention As has become clear from the above explanation, the thermal printer of the present invention includes a thermal head on the carriage that carries the thermal transfer film, and when the thermal head is printing, the thermal transfer is performed in synchronization with the moving speed of the carriage. When the film is wound and the thermal head is in a non-printing state and the carriage is returned, the thermal transfer film is wound at a speed slower than the moving speed, so when the print head returns from the printing position to the non-printing position, the thermal transfer Even if the film becomes somewhat loose, the thermal transfer film is wound up when the carriage is returned to the printing start edge, so the thermal transfer film that has been used once will not be used again. Further, since the thermal transfer film is wound up at a slow speed at this time, the thermal transfer film is not wasted much.

[Brief explanation of the drawing]

FIG. 1 is a top view of the main parts of a thermal printer according to an embodiment of the present invention in one operating state, FIG. 2 is a top view of the main parts in the same operating state, and FIG. 3 is a top view of the same. be. 1... Carriage 5... Thermal head 7...
・Thermal transfer film 11...Timing belt 18.
19.20.21.22.23...Gear 25.26.
...Pulley 27...Name of belt agent: Patent attorney Toshio Nakao and one other personIllustration 1

Claims (1)

[Claims] (1) A thermal head is provided on a carriage on which a thermal transfer film is mounted, and when the thermal head is printing, the thermal transfer film is wound in synchronization with the moving speed of the carriage, and when the thermal head is in a non-printing state. The thermal printer is characterized in that the thermal transfer film is wound up at a speed slower than the movement speed when the carriage is returned.