JPH085235B2 - Thermal transfer recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] The present invention relates to a thermal transfer recording apparatus for performing color transfer recording by a field sequential recording method in which a plurality of primary color inks are selectively overlapped and transferred for each page of a continuous recording sheet. An independent paper feed detection roller is provided between the recording paper roll and the platen roller, and the recording paper that reciprocates between the rolls is wound at a predetermined angle and is rotated with a constant tension applied to the paper transport. The amount of rotation of the detection roller during transfer recording is detected, and when the recording sheet is returned, the amount of rotation is returned by the same amount as the amount of rotation during transfer recording. The color misregistration that occurs during the overlapping transfer of the inks of the respective colors due to the difference of (3) is prevented, and high-quality color transfer recording is obtained.

[Industrial application field]

The present invention relates to an improvement in a thermal transfer recording device used as a print output device for a data processing terminal, and more particularly to a recording paper
The present invention relates to an apparatus configuration that prevents misregistration of color inks during color recording by a field sequential recording method in which a plurality of primary color inks are selectively superimposed and transferred for each page.

Thermal transfer recording is a non-impact recording method in which a heat-meltable ink layer formed on a sheet-shaped base material is selectively heated by a thermal head, and the melted ink is transferred to a recording sheet to print or record an image. Since it is used, the printing sound is quiet, the mechanism is simple, and the maintainability is excellent, thermal transfer color recording has been recently developed in accordance with diversification of recording information, and various types of apparatuses have been proposed.

As a method of performing color transfer recording by such a thermal transfer recording apparatus, a frame sequential recording method is mainly used in which a plurality of primary color inks are selectively overlapped and transferred for each page of a recording sheet. In color transfer recording by the method, color misregistration occurs when the return position accuracy of the recording paper for selectively overlapping and transferring the color inks is poor,
Since the recording quality deteriorates, there is a need for a structure that can accurately and stably realize superposition of inks of a plurality of colors.

[Conventional technology]

FIG. 3 shows a schematic structure of a conventional thermal transfer color recording apparatus of a frame-sequential recording type. In the figure, 1 is a recording paper roll around which a continuous recording paper 10 is wound, 2 is a platen roller, and 3 is a thermal head. Reference numeral 4 is a pinch roller, 5 is an ink sheet supply roll, 6 and 7 are idle rollers, 8 is an ink sheet winding roll, and 11 is an ink sheet.

The continuous recording paper fed from the recording paper roll 1
A step motor 10 is provided along the surface of the platen roller 2 by the pressure of the pinch roller 4 and between the ink sheet 11 fed from the ink sheet supply roll 5 and the thermal head 3 which is in pressure contact with the platen roller 2. 9
The platen roller 2 which is rotated by the driving of the sheet transports the sheet to the stacker side (not shown).

The ink sheet 11 has a resin sheet-like base material on which respective colorants such as yellow, magenta, cyan, and black are applied face-sequentially, and these colorants are melted by heating by the thermal head 3, It is transferred onto the recording paper 10 and then wound around the ink sheet winding roll 8.

At the time of color transfer recording, the recording sheet on the platen roller 2 with the thermal head 3 through the ink sheet 11 is used.
The recording sheet 10 is laterally scanned while being pressed against the sheet 10, and the recording sheet 10 is transported to perform thermal transfer recording of color information of the first color, for example, yellow on the surface of the recording sheet 10 for one page.

Next, when the recording of the first color is completed, the thermal head 3
Is separated from the platen roller 2, the recording sheet 10 is returned to the transfer recording start position of the first color by the reverse rotation of the platen roller 2, and the ink sheet 11 has the ink sheet winding roll with the colorant surface of the first color. The surface of the coloring material of the second color made of, for example, magenta, is wound up on the surface of the colored material.

Next, in this state, the thermal head 3 is continuously brought into pressure contact with the recording paper 10 on the platen roller 2 via the ink sheet 11, and a transfer process similar to the thermal transfer of the first color causes the first color information image of yellow. Transfer recording is performed by superposing a color information image of magenta of the second color on the surface of the recording paper 10 on which is recorded.

Hereinafter, by the same thermal transfer process, the color information images of the third color and the fourth color are sequentially superposed and the transfer recording is performed to obtain the recording of the full color information image for one page.

[Problems to be solved by the invention]

By the way, in the conventional thermal transfer color recording apparatus having the above-mentioned configuration, in the process of transferring and recording a plurality of coloring materials in sequence, one page of the recording paper 10
Alternatively, the transfer operation of reciprocating one screen a plurality of times is performed by the platen roller 2 which is rotated by the forward and reverse rotation drive of the step motor 9.

Therefore, the deformation of the surface of the platen roller 2 is different depending on the play (backlash) of the forward / reverse rotation drive system of the platen roller 2 and the presence / absence of pressure contact of the thermal head when the recording sheet 10 is fed and returned. Due to this, even when the step motor 9 is reversely rotated by the number of feeding drive pulses for one page at the time of returning the recording paper 10, the sheet returns to a position different from the original transfer recording start position for the one page, and Due to the displacement of the returning position, a color shift occurs between the superposed transfers of the respective color materials, and the recording image quality is deteriorated.

In view of the above-mentioned conventional drawbacks, the present invention eliminates the play of the forward and reverse rotation drive system of the platen roller by keeping the recording paper reciprocating between the recording paper roll and the platen roller in a state where a constant tension is always applied. Another object of the present invention is to provide a novel thermal transfer recording apparatus that eliminates color misregistration at the time of superposition transfer of each color material due to different deformation states of the platen roller surface portion during normal and reverse rotation.

[Means for solving problems]

In order to achieve the above object, the present invention provides a recording paper roll for feeding continuous recording paper onto a platen roller facing a thermal head, and attaches a torque applying mechanism that rotates in a direction opposite to the feeding direction of the paper, A paper feed detection roller is provided independently between the paper roll and the platen roller, the continuous recording paper being wound up being wound at a predetermined angle and rotated in a state in which tension is applied corresponding to the movement of the continuous recording paper. An encoder for detecting the rotation angle of the roller and a counter for counting output pulses from the encoder are attached to the detection roller.

[Action]

In the thermal transfer recording apparatus of the present invention, the recording paper roll is provided with a torque applying mechanism that rotates in a direction opposite to the feeding direction of the paper, and the continuous recording paper to be supplied is supplied to the platen roller surface between the recording paper roll and the platen roller. Since the paper feed detection roller is installed so as to be wound around the recording paper, the recording paper that reciprocates between the recording paper roll and the platen roller is always in a state where a constant tension is applied, for example, in the forward and reverse rotation drive system of the platen roller. Even if a play occurs, the detection roller is faithfully rotated without slipping or loosening with respect to the recording paper to be transported due to the arrangement position configuration.

Therefore, an encoder detects the rotation amount of the detection roller rotated by the recording paper fed during the transfer recording by the counter reset at the start of the transfer recording of one page or one screen, and the output pulse is up-counted. When the recording paper sheet is returned to its original position, the return amount is reversely counted down by the counter, and the driving of the platen roller is stopped at the time when the counter value becomes zero, so that it is fed out 1 The recording paper for one page or one screen is accurately returned to the original transfer recording start position.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a main part showing an embodiment of a thermal transfer recording apparatus according to the present invention.

In the figure, 1 is a recording paper roll around which a continuous recording paper 10 is wound, 2 is a platen roller provided with a step motor 9 for forward and reverse rotation drive, 3 is a thermal head, 4 is a pinch roller, and 5 is an ink sheet. Supply rolls 6, 6 and 7 are idle rollers, 8 is an ink sheet take-up roll, and 11 is an ink in which each color agent such as yellow, magenta, cyan and black is applied face-sequentially on a resin sheet-shaped substrate. It is a sheet.

A constant back tension is applied to the ink sheet 11 wound on the ink sheet winding roll 8 to prevent the displacement or slack from occurring due to scanning of the thermal head 3. The configuration up to this point is the same as the conventional one.

In contrast to these configurations, in the present invention, the driving DC motor 21 and the continuous recording paper are attached to the rotary shaft of the recording paper roll 1.
10 A torque applying mechanism including a constant current triber 22 that applies a torque that rotates in a direction opposite to the feeding direction is additionally provided.

A paper feed detection metal roller 23 is disposed between the recording paper roll 1 and the platen roller 2 so as to wind the continuous recording paper 10 to be supplied around the platen roller 2, and the detection metal roller 23 rotates. An encoder 24 that detects the rotation angle of the shaft and a counter 25 that counts the output pulse from the encoder 24 are attached to the shaft.

The diameter of the detection metal roller 23 and the angle division number of the encoder 24 are set so that one pulse is output every time the recording paper 10 is transferred, for example, 1/16 line.

Further, reference numeral 26 is a control unit for outputting a paper feed pulse to a step motor 9 attached to the platen roller 2 via a motor drive 27.

The recording paper roll 1 during transfer recording is a constant current triber 22.
And the driving DC motor 21 drive the platen roller 2 at a constant torque in a direction opposite to the feeding direction of the continuous recording paper 10.
The recording paper 10 rotates in the feeding direction due to the rotational driving force of the recording paper 10. However, when the radius of the recording paper roll 1 is r and the constant torque is Te, the back tension is expressed by the following equation. F _B is granted.

F _B = Te / r On the other hand, when the recording paper 10 is returned, the recording paper roll rotates in the original rotation direction (opposite to the paper feeding direction).
However, since the torque is controlled to a constant torque Te, it is driven by the reverse rotation speed of the platen roller 2 and the recording paper 10 is wound with the back tension F _{B applied.} The action taken is taken.

Further, the paper feed detection metal roller 23 provided between the recording paper roll 1 and the platen roller 2 has a shape in which the recording paper 10 to which tension is applied is wound around an angle of about 90 degrees in this embodiment. When the recording paper 10 is rotated, slippage between the recording papers 10 is prevented, and the recording papers 10 are faithfully driven to rotate without sagging when the recording papers 10 are transported in the forward and reverse directions.

Next, the operation of performing thermal transfer color recording by the apparatus configuration of this embodiment will be described.

As shown in FIG. 1, during transfer recording, the thermal head 3 is brought into a state of being pressed against the recording paper 10 on the platen roller 2 via the ink sheet 11. Then, during this period, the ink sheet 11 is transferred, and on the one-page surface of the recording paper 10 which is fed by the rotational driving of the platen roller 2,
The thermal head 3 is selectively heated and driven in the width direction to thermally transfer the color information image of the first color, for example, yellow.

At this time, the rotation of the platen roller 2 is controlled by the control unit.
The stepping motor 9 is driven at a predetermined speed by a sheet feeding pulse output from the stepping motor 26, and the stepping motor 9 makes micro-step driving of 16 pulses for one line, thereby highly accurately transferring the recording sheet by the rotation of the platen roller 2. It has become.

On the other hand, at the same time when the thermal transfer of the color information image of the first color is started on the first page surface of the recording sheet 10, the counter 25 is reset to zero by a signal from the control section 26, and the recording sheet is fed out during the transfer of the first sheet surface. Encoder that outputs according to the rotation amount of the paper feed detection metal roller 23 that rotates by 10
The output pulse from 24 is up-counted by counter 25.

Next, when the thermal transfer of the color information image of the first color is completed, the thermal head 3 is separated from the platen roller 2, and the ink sheet 11 has the color material surface of the first color wound up on the ink sheet winding roll 8 side. Then, the recording material 10 is returned to the transfer recording start position of the first color by the reverse rotation of the platen roller 2 while the cue of the color material surface of, for example, magenta is performed.

When returning the paper, the counter 25 down-counts the return output pulse from the encoder 24, and when the count value of the counter 25 reaches the subtraction zero, the control signal from the control unit drives the step motor 9 to drive. Since the pulse is cut off and the reverse rotation of the platen roller 2 is stopped, the page surface of the first color of the recording paper 10 is accurately returned to the transfer recording start position of the first color.

Next, in this state, the thermal head 3 is continuously brought into pressure contact with the recording paper 10 on the platen roller 2 via the ink sheet 11, and a transfer process similar to the thermal transfer of the first color causes the first color information image of yellow. Transfer recording is performed by superposing a color information image of magenta of the second color on the surface of the recording paper 10 on which is recorded.

Thereafter, by the same thermal transfer process, the color information images of the third color and the fourth color are sequentially superposed and transfer recording is performed to obtain a full-color information image for one page.

As described above, in the apparatus configuration of the present embodiment, in any situation when the recording paper 10 is fed out or returned to the original transfer recording start position when transfer recording is performed by superposing color information images of a plurality of colors in order. Also, since tension is always applied and slack does not occur, there is no misalignment of the return position of the recording paper 10 due to backlash of the platen roller 2 in the forward / reverse rotation drive system, and when the recording paper 10 is returned, the same amount as the feeding amount It is possible to accurately return the recording paper 10 to the original transfer recording start position with the returning amount.

Therefore, the superimposed transfer recording of a plurality of colors can always be started from the same transfer recording start position, so that the color shift at the time of the superimposed transfer can be prevented.

In the above embodiment, the paper feed detection metal roller 23 provided between the recording paper roll 1 and the platen roller 2 is
An example of the case where the recording sheet 10 is placed in direct contact with the transfer recording surface of the recording sheet 10 has been described, but the present invention is not limited to this example. For example, as shown in the schematic configuration diagram of FIG. It may be installed so as to come into contact with the non-transfer back surface of the recording paper 10, and the same effect is obtained.

〔The invention's effect〕

As is clear from the above description, according to the thermal transfer recording apparatus according to the present invention, the misalignment of the returning position of the recording paper at the time of the superimposed transfer of the color inks by the frame sequential recording method is eliminated, and the overlapping accuracy of the color inks Since it is well stabilized, it has an excellent advantage that clear color and high quality full color transfer recording without color shift is possible, and it is extremely advantageous when applied to this type of thermal transfer recording apparatus.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of essential parts showing an embodiment of a thermal transfer recording device according to the present invention, and FIG. 2 is a schematic configuration diagram of essential parts for explaining another embodiment of a thermal transfer recording device according to the present invention, FIG. 3 is a schematic configuration diagram of a main part for explaining a conventional thermal transfer recording device. 1 and 2, 1 is a recording paper roll, 2 is a platen roller, 3 is a thermal head, 4 is a pinch roller, 5 is an ink sheet supply roll, 8 is an ink sheet take-up roll, 9 is a step motor, 10 is a continuous recording paper, 11 is an ink sheet, 21 is a DC motor, 22 is a constant current driver, 23 is a metal roller for paper feed detection, 24 is an encoder, 25 is a counter, 26 is a control unit, and 27 is a motor driver. .

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B41J 15/16

Claims (1)

[Claims] 1. A thermal recording head is driven by an ink sheet having a plurality of color ink surfaces sequentially provided on a continuous recording paper which is fed from a recording paper roll and guided on a platen roller, by a frame sequential recording system. In an apparatus configuration for performing thermal transfer color recording, a torque applying mechanism that rotates in a direction opposite to the paper feeding direction is attached to the recording paper roll, and continuous feeding is independently performed between the recording paper roll and the platen roller. A paper feed detection roller is provided which rotates the recording paper at a predetermined angle and rotates in a state where tension is applied corresponding to the movement of the continuous recording paper, and further, an encoder for detecting the rotation angle of the roller is provided on the detection roller, and A counter that counts the output pulses from the encoder is attached, and the counter that is set to a predetermined value at the start of transfer recording of one screen The output pulse of the encoder that outputs according to the rotation amount of the detection roller that is rotated by the recording sheet that is fed out during recording is up-counted, and the output pulse of the encoder when returning the recording sheet to the original position. On the contrary, the thermal transfer recording apparatus is characterized in that the driving of the platen roller is stopped when the counted value reaches a predetermined value which is initially set.