JPS60155484A - Thermal transfer printer - Google Patents

Abstract

PURPOSE:To prevent slipping from occurring between an ink sheet and a paper, by a method wherein the width of an ink sheet is so set that the ink sheet protrude beyond side edges of a paper substantially evenly on both sides, and the sheet is driven to move through frictional forces by pressure-clamping the protruding parts of the sheet by driving rollers. CONSTITUTION:A paper 10 and an ink sheet 20 are pressure-clamped between a platen 30 and a thermal head 40 in a laminated condition, and are driven to move by pressure rollers 50 and an auxiliary driving roller 54 operated in conjunction with the platen 30. The pressure rollers 50 press the protruding parts 20a, 20a of the ink sheet 20 on both sides of the paper 10 against the auxiliary driving roller 54, and the ink sheet 20 is driven to move by the frictional forces generated by the clamping. Accordingly, the ink sheet and the paper are prevented from slipping relatively to each other, and favorable transfer free of exfoliation of printed dots can be performed.

Description

TECHNICAL FIELD This invention relates to a thermal transfer printer, which is used, for example, as a facsimile recording device or a combiator output device.

BACKGROUND TECHNOLOGY Conventionally, thermal transfer printers used as facsimile recording devices or output devices for convenience stores and word processors transport paper and an ink sheet in a stacked manner, and use a thermal head to absorb ink from the ink sheet. There is one that selectively heats and transfers onto the above-mentioned paper.

In this case, the ink sheet is conveyed while being held under pressure between the platen and the head while being overlapped with the paper.

However, in the conventional thermal transfer printer described above, the mutual relationship among the friction force Ml between the platen and the paper, the friction force M2 between the paper and the ink sheet, and the friction force M3 between the ink sheet and the head is as follows. If condition t-Ml>>M2>>M3 is not satisfied, slippage will occur between the paper and the ink sheet, which will cause the problem of peeling of the transfer dots and failure to obtain a good transferred image. . Furthermore, the frictional forces Ml, M2. The relationship between the size of M3 varies unstably depending on the type of paper used, the condition of the paper surface, the ink sheet load due to sticking in the heating section of the thermal head, etc. Therefore, the relationship between the ink sheet and the paper It is very difficult to prevent slippage between
Its purpose (work, ink sheets, paper and
- To provide a thermal transfer printer which prevents slippage between an ink sheet and paper when they are conveyed in layers, and thereby allows for the best transfer without dot peeling. The configuration of the thermal transfer printer according to the invention is such that a thermal transfer printer transports paper and an ink sheet in an overlapping manner, and selectively thermally transfers ink from the ink sheet to the paper using a thermal head. The ink sheet is characterized in that the width of the ink sheet is spread almost equally to both sides of the paper so that it protrudes, and the protruding portion is pressed and clamped by a drive roller to be moved and driven by frictional force.

Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

Note that the same or corresponding parts in the figures are indicated by the same reference numerals. FIGS. 1 and 2 show an embodiment of a thermal transfer printer according to the present invention.

First, Figure i@1 schematically shows the overall structure of a thermal transfer printer according to the present invention, which includes a platen 30 that presses and holds sheets 10 and ink sheets 20 stacked on top of each other, and a thermal head 40. It also has a motor 32 that drives the platen 30, a pressure means 42 that presses the thermal head 40 against the platen 3o, etc.
Furthermore, it has pressure rollers 50 which press and hold both sides of the ink sheet 20 and are moved and driven by frictional force.

The pressure roller father is provided with a spring 52 and an auxiliary drive roller 54 for applying pressure. The auxiliary drive row 254 is connected to the platen 30 via a belt.

In addition, 22 is the roll of the ink sheet before transfer, and 2
4 shows the rolls of ink sheets after transfer.

FIG. 2 shows the main parts of the thermal transfer printer according to the present invention, and particularly shows the vicinity of the auxiliary drive roller 54 and the pressure roller.

In FIG. 2, the pressure roller 50 is applied to both sides of the ink sheet 20 stacked on the paper 10, at the protruding portion 20m,
20B is pressed against the auxiliary drive roller 541m, the width of the ink sheet 20 is spread almost equally to both sides of the paper 10, and the ink sheet 20 is made to protrude from the paper 10, and the protruding portions 20a, 2
0a is clamped under pressure between a group of pressure rollers and a driving row 28, and is driven to move by the frictional force caused by this clamping. As a result, the ink sheet 2
It is possible to secure a sufficiently large frictional force for driving the ink sheet to move the ink sheet, thereby reliably preventing slippage between the sheath 10 and the ink sheet, and ensuring good transfer without dot peeling. FIG. 3 shows the main parts of a further preferred embodiment of the thermal transfer printer according to the present invention.

In the embodiment shown in the figure, the above-mentioned protruding portion 20a.

20at-The means for clamping under pressure operates in synchronization with the means for releasing the thermal head. That is, the pressure roller father is interlocked with the thermal head off via the arm 44, and the crank mechanism 4
5, when the thermal head rotates and releases the pressurized state of holding the paper 10 and the ink sheet 20, the lower part of the head pack pushes down the holding bin 46. ) is also released at the same time.

At this time, the axis becomes a rotational fulcrum for the arm 44 and the thermal head.

This embodiment is particularly effective for realizing color transfer. That is, during color transfer, color expression is performed by overlapping transfer of inks applied sequentially onto an ink sheet. Therefore, during the time period when the ink sheet moves in the forward direction and the next color is set, the paper is
The paper and ink sheet must be moved in the opposite direction and returned to the initial position of overlapping. At this point, the pressurized state by the thermal head is released to allow the paper and ink sheet to move freely relative to each other, and the pressure roller is If the complete release of the pressurized state is linked to each other, that is, if the configuration is configured as in the above embodiment, the above-described operation can be easily performed without using a dedicated electromagnetic plunger 4-, for example, to release the pressure roller. It will now be possible to achieve color transfers similar to those shown below.

Effects As described above, in the thermal transfer printer according to the present invention, it is possible to prevent slippage between the ink sheet and the paper when conveying the ink sheet and paper in layers, thereby preventing dots from peeling off. 1. Good transfer can be performed.

[Brief explanation of drawings]

FIG. 1 is a sectional view schematically showing the overall configuration of a printer according to an embodiment of the present invention, FIG. 2 is a front view showing the main parts of the printer shown in FIG. 1, and FIG. It is a figure which shows the principal part of another Example. 10... Paper 20... Ink sheet 22.24.
... Ink roll 30 ... Platen 32 ... Platen drive motor 40 ... Thermal head 42 ...
・Pressure means Material...Arm 45...Crank mechanism 4
6... Engagement pin 48... Shaft 50... Pressure roller 52... Pressure spring 54... Drive roller 20
a...Protruding part of the ink sheet Applicant Kiyoshi Torii Figure 1 Figure 2 ==Koku υ Ri υ Kuku

Claims (2)

[Claims] (1) In a thermal transfer printer that transports paper and an ink sheet in an overlapping manner and selectively heats and transfers the ink from the ink sheet to the paper using a thermal head, the width of the ink sheet that overlaps the paper is set on both sides of the paper. A thermal transfer printer characterized in that it is spread almost evenly to the sides and protrudes, and the protruding portion is pressed and clamped by a drive roller to be moved and driven by frictional force. (2) The thermal transfer printer according to item 1, wherein the means for pressurizing and clamping the protruding portion operates in a delayed manner relative to the releasing means for the thermal head.