JPH0347771A - Thermal transfer color line printer - Google Patents

Abstract

PURPOSE:To prevent a misregistration of colors even if a color printing is conducted using recording paper of different material, to simplify a paper feed mechanism part, and to lower a production cost by a method wherein a detection part for measuring a frictional force of recording paper is provided in a paper feed path, and the rotational speed of a motor for feeding recording paper forward and backward is controlled by an output signal from the detection part. CONSTITUTION:Recording paper 18 payed out from a hopper 7 by a pick roller 1 is applied with a frictional force by a friction plate 3, whereby a piece of the recording paper 18 is supplied into a device. The deflection of a detection needle of a pressure plate 2 caused by the frictional force at this time is detected by a detector 6. The detection signal is transmitted to a control part 17. In accordance with the coefficient of friction of the recording paper 18, a slip amount when the recording paper 18 is fed forward and backward while being clamped between a platen 10 and a platen pinch roller 11 and a platen pinch roller 12 is experimentally found. Next, the rotating speed of a platen motor 13 for driving the plate 10 is controlled in accordance with an output signal from the detector 6. In this manner, a feed amount can be kept constant even if the material of the recording paper 18 is changed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal transfer color line printer, and more particularly to a thermal transfer color line printer having a recording paper feed control mechanism.

[Conventional technology]

Conventionally, this type of line-type color printer transfers each color of ink applied to an ink ribbon in a field-sequential manner.
Multicolor printing is performed by pressing the recording paper against the thermal head with a platen and moving it back and forth for each color so that they overlap.

FIG. 2 is a sectional view of a mechanical part of a printer showing an example of such a conventional printer.

As shown in FIG. 2, the conventional thermal transfer color line printer feeds recording paper 18 from a hopper 7 using a big roller 1, a friction plate 3 pressed by a pressure roller 1, a pressure plate 2, and a spring 4. Paper. On the other hand, the printing section has paper feed rollers 8 and 9.
The recording paper 18 that has been fed as a sheet is pressed against the thermal head 14 together with the ink ribbon 15 by the platen 1o, and the ink of each color is transferred onto the recording paper 18. At this time, the recording paper 18 is reciprocated by the platen motor 13, cabstan rollers 21, 22, pinch rollers 23, 24, and paper guide 16 to print in each color.

[Problem to be solved by the invention]

In the conventional printer described above, the recording paper 18 is fed back and forth using the platen roller 10, but if the material of the recording paper 18 changes, the coefficient of friction with the platen roller 10 changes.
There is a drawback that slip occurs between the recording paper 18 and the platen roller 10, making the printing position unstable, resulting in color shift and deterioration of printing quality. In addition, in order to prevent this, if a paper feeding mechanism consisting of capstan rollers 21, 22 and pinch rollers 23, 24 for feeding the paper is arranged before and after the thermal head 14,
This method has disadvantages in that the mechanism becomes complicated and the cost of the device increases, and the distance between the thermal head 14 and the paper feed mechanism is longer than that in the platen drive, which greatly limits the printing range on the recording paper.

An object of the present invention is to provide a thermal transfer color line printer that does not cause color misregistration depending on the type of recording paper, and that simplifies the paper feeding mechanism and reduces manufacturing costs.

[Means to solve the problem]

The thermal transfer color line printer of the present invention has a big roller that feeds recording paper one by one into the device from a hopper unit, and a big roller that prevents feeding more than two sheets of recording paper at a time and tilts the recording paper according to the friction coefficient of the recording paper. A pressure plate that has an actuator section that changes the amount of pressure, a detector that detects the position of the actuator section, a platen roller that sends recording paper based on the output signal of the detector, a platen motor that drives the platen roller, and a detector that detects the position of the actuator section; and a control section that controls the amount of rotation.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a mechanical part of a thermal transfer color printer showing an embodiment of the present invention.

As shown in FIG. 1, in this embodiment, a big roller 1 and a friction plate 3 held by a pressure plate 2 are in pressure contact with each other by a spring 4, and recording sheets 18 are fed into the apparatus one by one from a hopper 7. do. This pressure plate 2
is pivotally supported so as to be swingable, and is tensioned by a spring 5, and a portion thereof serves as a detection needle that indicates inclination. Further, a detector 6 capable of detecting the amount of inclination is provided at a position facing the detection needle, and a control section 17 controls the platen motor 13. Further, the paper feed mechanism includes a paper suction roller 8 and a paper suction roller 9 that feed the recording paper 18 supplied into the apparatus between the thermal head 14 and the platen roller 12, and a paper guide 16 to guide the recording paper 18 into the printing operation. The platen pinch roller 11 and the platen pinch roller 12 press the recorded paper 18 against the platen 10 and reciprocate. Further, the ink ribbon 15 is arranged to cover the thermal head 14.

Next, the operation of such a printer will be explained.

First, the recording paper 18 fed out from the hopper 7 by the big roller 1 is rubbed by the friction plate 3, and only the -sheet is fed into the apparatus. Due to the frictional force at this time, the inclination of the detection needle of the pressure plate 2 is detected by the detector 6, and the signal is sent to the control section 17. The amount of slip when the recording paper 18 is fed back and forth while being pinched between the platen 10, the platen pinch roller 11, and the platen pinch roller 12 is determined experimentally based on the friction coefficient of the recording paper 18.

Next, by controlling the rotation speed of the platen motor 13 that drives the platen 10 according to the output signal of the detector 6, the feed amount is kept constant even if the material of the recording paper 18 changes.

〔Effect of the invention〕

As explained above, the thermal transfer color printer of the present invention is provided with a detection unit that measures the frictional force of the recording paper in the paper feeding path, and uses the output signal to control the amount of rotation of the motor that reciprocates the recording paper. As a result, even if color printing is performed using recording paper made of different materials, no color shift occurs, the paper feeding mechanism can be simplified, and manufacturing costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a mechanical part of a thermal transfer color line printer showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a mechanical part of a printer showing a conventional example. 1...Pick roller, 2...Pressure plate,
3... Friction plate, 6... Detector, 7... Hopper, 10... Platen, 13... Platen motor, 1
4... Thermal head, 15... Ink ribbon, 1
7...Control unit, 18...Recording paper.

Claims (1)

[Claims] In a thermal transfer color line printer, an ink ribbon coated with multiple colors of ink is pressed against a thermal head via a recording paper by a platen in a field sequential manner, and color printing is performed while the recording paper is fed back and forth for each color. A thermal transfer color line printer, characterized in that a detection section for measuring the frictional force of the recording paper is provided in the path, and the amount of rotation of a motor for reciprocating the recording paper is changed in accordance with the output signal of the detection section. .