JPS6021289A - Thermal transfer printer - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer printer enabled in the common-use of both ribbon cassettes and capable of always obtaining optimum printing quality, by detecting an one-time ribbon cassette and a multi-time ribbon cassette in a discriminating part, and selecting a feed pitch corresponding to the detected cassette. CONSTITUTION:When a one-time ribbon cassette 22 is mounted to a cassette holder, the drive shaft 26 of a pitch change-over mechanism is held under a state upwardly moved by a spring because no discriminating part 200 protruded from a cassette case is provided to said cassette 22. As a result, a first change-over whell 46 is meshed with a first change-over pinion 50 and feed driving is performed at a relatively large pitch and overlap printing is prevented. On the other hand, when a multi-time ribbon cassette is mounted to a cassette holder, the drive shaft 36 is downwardly pushed by the discriminating part 200 and, as a result, a second change-over pinion 48 is meshed with a second change-over wheel 52 and feed driving is performed at a relatively small pitch.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to improvements in ribbon feeding systems in thermal transfer printers, particularly printers using ribbon cassettes.

Background technology A thermal transfer ribbon is inserted between the paper and the thermal head,
Thermal transfer printers are well known, which apply printing commands to a thermal head to fuse ink on a thermal transfer ribbon to paper, and combine these welded dots to form desired characters. Because it can perform printing functions, it is used as a printer for various information devices and other devices.

In this type of thermal transfer printer, in order to facilitate replacement of the thermal transfer ribbon, which is a consumable item, the ribbon is usually assembled in a cassette. The printer is provided with a cassette holder mechanism that mounts the ribbon cassette in a predetermined position, and a feed mechanism that drives the thermal transfer ribbon to be fed by a predetermined amount in conjunction with a printing operation.

As is well known, ribbon quality is extremely important in thermal transfer printers, and with conventional ribbons, most of the ink on the base paper is eluted during one thermal transfer, making it difficult to double print at the same location. Met. Therefore, in conventional ribbon cassettes, the feeding pitch is set so that the ribbon positions do not overlap for each thermal transfer printing.

As a result, with conventional ribbon cassettes, thermal transfer is always carried out in unused positions, resulting in high-quality printing. However, on the other hand, ribbon usage efficiency is reduced because the feed pitch must be set relatively large. Evil (, it had the drawback of being extremely consuming.

In contrast to the one-time ribbon cassettes mentioned above, in recent years improvements in ink have led to the development of cassettes with built-in multi-time ribbons that can withstand multiple uses, making it possible to overprint thermal transfer ribbons. It has become. Therefore, using such a multi-time ribbon can improve the efficiency of ribbon use and significantly reduce its wear. However, it is undeniable that the print quality due to multi-time ribbon printing is lower than the one-time ribbon quality described above, and both types of ribbon cassettes can be commonly installed in printers. It is possible to use both depending on the need.

As a conventional common shared mechanism, the feed pitch is constant for both force sets, but in the case of multi-time ribbons, a mechanism has been proposed that allows the ribbon to be used multiple times by reversing the feeding direction of the ribbon. However, this reversing mechanism actually has the disadvantage that its structure is complicated, and depending on the reversal timing, the ribbons may not overlap each other, resulting in a significant drop in printing quality.

Purpose of the Invention The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to enable both one-time ribbon cassettes and multi-time ribbon cassettes to be used in common, and to provide a system that is optimal for both ribbon cassettes. An object of the present invention is to provide an improved thermal transfer printer that can maintain high printing quality.

Structure of the Invention In order to achieve the above object, the present invention makes it possible to set different feed pitches for both ribbon cassettes, and selects the optimum feed pitch by detecting the identification part of both force sets. Features.

Description of examples Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows the main parts of a preferred embodiment of the thermal transfer printer according to the present invention.
is rotatably supported, and a predetermined paper feeding action can be applied to the paper 14 by a drive mechanism (not shown).

A head assembly 16 is provided opposite the platen 12, and the head assembly 16 in the embodiment can reciprocate in the axial direction of the platen 12, and the entire head assembly 16 is moved by a belt or the like by a head motor (not shown). Driven. The head assembly 16 includes a thermal head, a cassette holder, and a ribbon feeding mechanism.

As is well known, the thermal head 18 incorporates a plurality of microfilaments, and heating current is supplied to the selected filaments by applying a predetermined printing command, and the ribbon 20 guided between the thermal head 18 and the paper 14 is heated to a predetermined value. The points can be welded to the paper 14.

Although only the take-up shaft 28 and guide shaft 30 of the cassette holder of the head assembly 16 in the embodiment are shown that engage the take-up spool 24 and unwind spool 26 of the cassette 22, as is well known, the cassette holder is provided with a positioning guide for holding the cassette 22 in a predetermined position.

The cassette 22 in FIG. 1 is a one-time ribbon cassette, and by simply aligning its spools 24 and 26 with the shafts 28 and 30 on the cassette holder side and installing it, the ribbon 20 can be transferred to the paper 14 and the thermal head 18.
It can be installed between the two.

As described above, the head assembly 16 is provided with a ribbon feeding mechanism, and in this embodiment, the ribbon is fed using the reciprocating driving force of the head assembly 16.

That is, the upper plate 32 and lower plate 34 of the head assembly 16
A drive shaft 36 is pivotally supported at @, and a drive wheel 38 is fixed to the drive shaft 36. and said drive ll3
Rack teeth 40 are formed on the opposite surface of the device base 10 when the drive shaft 8 reciprocates, and a transmission wheel 44 is pivotally supported on a receiving plate 42 supported on the drive shaft 36. , when the head assembly 16 is moved, the transmission wheel 44 is moved by the rack teeth 4.
4 and the drive wheel 38, so that as the head assembly 16 moves, the drive shaft 36 is rotated by a predetermined pitch.

Although not shown in detail, the transmission lI 44 engages the rack teeth 40 and the drive wheel 38 only when the head assembly 16 is moved in one direction, and another transmission wheel is used when the head assembly 16 is moved in the opposite direction. , the drive shaft 36 can always rotate in one direction with respect to the reciprocating movement of the head assembly 16.

As described above, the drive shaft 36 is connected to the head assembly 16.
The ribbon is rotationally driven when it moves, and by transmitting this driving force to the take-up shaft 28, desired ribbon feeding becomes possible. The feed pitch switching mechanism in the features and embodiments includes a first switching wheel 46 and a second switching pinion 48 fixed to the drive shaft 36, and a first switching pinion 50 and a second switching pinion fixed to the aforementioned winding shaft 28. Includes car 52. Then, any one of the pair of the first moss wheel 46 and the first switching wheel A 50 and the pair of the second switching wheel 48 and the second switching wheel 52 are selectively engaged, and the transmission and feeding of these By switching the pair, it is possible to switch the feed pitch.

In the embodiment, the drive shaft 36 is always pressed upward in FIG.
The pair with 0 is in an engaged state, and this engaged state indicates a state in which the one-time ribbon cassette is used.

One-time ribbon cassettes and multi-time ribbon cassettes have almost the same shape, but in order to simply identify both types, one of the cassettes is provided with an identification section, and FIG. 3 shows an identification section 200. A multi-time ribbon cassette 122 is shown having an identification section 20.
0 is formed as a protrusion from the cassette case.

The embodiment of the present invention consists of the above-mentioned configuration, and its operation will be explained below.

As shown in FIG. 1, when the one-time ribbon current 22 is attached to the cassette holder, this cassette 22
Since there is no identification part 200 protruding from the cassette case, the driving shaft 36 of the pitch cutting front fII structure is moved upward by the biasing spring 54, and as a result, the first switching middle 46 and the first switching The support pinion 50 meshes with the one-time ribbon 20, and the one-time ribbon 20 is driven to be fed by a relatively large pitch.As a result, the ribbon 20 is not overstruck.

Meanwhile, multi-time ribbon cassette 1 is placed in the cassette holder.
22 is attached, the identification part 200 protrudes from the cassette case.
00 pushes down the drive shaft 36 as shown by arrow A, and as a result, the second switching pinion 48 and the second switching wheel 52
As a result, the multi-time ribbon 120 is fed and driven at a relatively small pitch to achieve the desired overprinting.

Therefore, according to this embodiment, the ribbon feeding pitch can be switched to a different ω corresponding to each cassette simply by installing a cassette of either type in the cassette holder, and the multi-time ribbon current can be installed. When a multi-time ribbon cassette is installed, the feed pitch is increased to enable high-quality printing without overprinting, and when a multi-time ribbon cassette is installed, the feed pitch is decreased to perform overprinting to reduce ribbon wear. becomes possible.

In the embodiment, the multi-time ribbon cassette is provided with an identification part that protrudes from the cassette case, but such an identification part is formed from a cutout or other part of the cassette case, and is also provided on the one-time ribbon cassette side. Of course, it is also possible to provide the same.

Furthermore, in the embodiment, the feed pitch corresponding to the dual force set is switched by moving the drive shaft in the axial direction, but such a switching mechanism can be implemented using any other arbitrary structure, such as a switching type selective meshing mechanism. In the embodiment, the identification part of the cassette is detected mechanically, but in the present invention, such detection is performed electrically, and the identification part of the cassette is detected using an electromagnetic solenoid. It is also possible to switch the pitch.

As described in detail, according to the present invention, since the ribbon feeding pitch is switched by detecting the identification portion of ribbon cassettes of different types, it is possible to perform an optimal printing operation corresponding to each cassette. It is possible to provide a ribbon feeding mechanism that is extremely useful for small-sized thermal transfer printers that do not require complicated structures such as conventional reversing machines.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts showing a preferred embodiment of the thermal transfer printer according to the present invention, FIG. 2 is a sectional view of essential parts showing the inside of the cassette of FIG. 1, and FIG. 3 is a multi-time ribbon in this embodiment. FIG. 3 is a cross-sectional view of the main part with the cassette attached. 14...Paper, 16...Head assembly, 18...Thermal head, 20...One-time ribbon, 22...One-time ribbon cassette, 28...
- Winding shaft, 36... Drive shaft, 46... First switching wheel, 48... Second pinion, 50... First pinion, 52... Second switching wheel, 120... Multi-time ribbon, 122,...
- Multi-time ribbon cassette, 200... Identification section. Agent: Patent Attorney Kenji Yoshida Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In a thermal transfer printer that guides a thermal transfer ribbon in a ribbon cassette between a paper and a thermal head and feeds the ribbon in conjunction with printing, the ribbon feed is performed by detecting the distinction between a one-time ribbon cassette and a multi-time ribbon cassette. A thermal transfer printer characterized by automatically changing the pitch according to each cassette.