JPH07108581B2 - Color recording device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color recording apparatus, such as a television image or a captain system, which is useful for a hard copy of a full-color image and which can easily obtain a high-quality image in a small size. is there.

2. Description of the Related Art In recent years, there has been a remarkable tendency toward colorization of display devices such as CRTs, and accordingly, hard copy devices capable of recording in color have been demanded. Above all, the thermal transfer method is attracting attention as a part of colorization of many terminal printers such as office automation equipment because of its excellent quietness and maintainability.

Generally, when performing color recording using the thermal transfer method,
As shown in FIG. 2, while the ink sheet 2 and the image receiving paper 1 on which the inks are separately applied in the respective color planes are conveyed in the direction of arrow a,
The thermal head 3 in which the heating elements 3a are linearly arranged is pressed against the platen roller 4 via the ink sheet 2 and the image receiving paper 1 to heat the heating elements according to the image information for each line of each color, Recording is performed by thermal transfer. In this way, after printing one page with the ink of the first color, the image receiving paper 1 is pulled back in the direction of the arrow b so that the recording start position comes to the thermal head portion, and then one page of the second color is printed. Make a recording and repeat the first one
A page image is recorded and a color image is recorded by the subtractive color mixing method. Conventionally, the image receiving paper 1 is sandwiched at the position where the pinch rollers 5 and 6 are pressed against the platen roller 4, and is reciprocally conveyed by rotating the platen roller 4 by the driving means 7.

Problems to be Solved by the Invention However, with such a method, the image receiving paper 1 is conveyed at the two pressure contact points of the platen roller 4 and the pinch rollers 6 and 7, and the pressure contact conditions at these two points are accurately measured. If they do not match, the amount of conveyance of the image receiving paper 1 at both pressure contact points is different. As a result, the image receiving paper 1 is slackened without being wound around the platen roller 4, or the image receiving paper 1 slides on the platen roller 4 at the pressure contacting position of either pinch roller, and at the pressure contacting position of the recording means 3 and the platen roller 4. Receiving paper 1
However, it is difficult to obtain accurate position reproducibility and color shift occurs.

Means for Solving the Problems In order to solve the above problems, the present invention provides a pinch roller on the downstream side of two pinch rollers at the time of pulling back from an upstream pinch roller that rotates following the platen roller. A pinch roller driving unit that rotates at a high peripheral speed and a clutch mechanism that makes the pinch roller driving unit effective only when the pinch roller is pulled back are provided, and at the time of recording, both of the pinch rollers rotate following the platen roller, When pulling back, only the upstream pinch roller rotates following the platen roller, and the downstream pinch roller rotates at a higher peripheral speed than the upstream pinch roller. The deviation can be reduced.

Operation The present invention has the above-mentioned configuration, and the image receiving sheet conveying means is simplified by only the platen roller and the pair of pinch rollers which are in pressure contact with the platen roller. Since the pressure contact position can be brought closer to the recording means, the non-recording portion on the image receiving paper can be shortened. Furthermore, when pulling back, only the upstream pinch roller of the pair of pinch rollers rotates following the platen roller, and the downstream pinch roller rotates at a faster peripheral speed than the upstream pinch roller. By preventing the paper from slacking on the platen roller, it is possible to improve conveyance accuracy and reduce color misregistration.

Example Hereinafter, the configuration of an example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a basic configuration diagram of a color recording apparatus according to an embodiment of the present invention. In FIG. 1, 11 is an image receiving paper and 12 is PE.
An ink sheet in which ink that has fluidity due to heating is applied separately on the surface facing the image receiving paper 11 on a support such as T film by one page for each color, yellow, magenta, and cyan, and 13 receives the heating element 13a Line type thermal heads arranged linearly in the width direction of the paper 11, 14 is the image receiving paper 11
A platen roller wound around a part of the
It is a pinch roller of the same material and shape that is pressed against the platen roller 14 via 11. Reference numeral 17 is a driving means such as a step motor for rotationally driving the platen roller 14 bidirectionally, 18 is an intermediate pulley, 19 and 20 are timing belts, and the intermediate pulley 18 and the timing belts 19 and 20 apply the rotational force of the drive pulley 17a to the platen roller. It constitutes a driving force transmitting means for transmitting to the pulley 14a. Further, 21 and 22 are sheet guides that operate integrally with the thermal head 13 to guide the ink sheet 12, and 23 is a fixed shaft 2 that rotatably supports a pinch roller shaft 15a.
A pinch roller support member that rotates around 3a, a pinch roller support member that rotates around an intermediate pulley shaft 18a that rotatably supports and fixes the pinch roller shaft 16a, and 25.
Is a tension coil spring stretched between the pinch roller supporting member 23 and a casing (not shown) so that the pinch roller 15 is pressed against the platen roller 14, and 26 is a pinch roller support so that the pinch roller 16 is pressed against the platen roller 14. A tension coil spring stretched between a member 24 and a casing (not shown) is configured so that the pressure contact force of the pinch roller 15 against the platen roller 14 is stronger than the pressure contact force of the pinch roller 16. 27 is a pinch roller pulley, 28 is a timing belt that transmits the rotational force of the intermediate pulley 18 to the pinch roller pulley 27, 29 is fixed to the pinch roller pulley 27, and the pinch roller shaft 16a is attached to the pinch roller pulley 27. It is a clutch mechanism such as a one-way clutch that rotatably supports only in the direction of arrow c. Here, the pinch roller pulley 27 and the timing belt 28 constitute a pinch roller driving means for rotating the pinch roller 16 at a peripheral speed higher than the peripheral speed of the pinch roller 15 rotating following the platen roller 14, and a clutch mechanism. Reference numeral 28 transmits the driving force of the pinch roller pulley 27 to the pinch roller 16 only when pulling back.

Next, the operation of the color recording apparatus in this embodiment will be first described.
It will be described with reference to the drawings. Before the start of recording, the image receiving paper 11 is in close contact with the platen roller 14 between the position where the pinch roller 15 is pressed against the platen roller 14 and the position where the pinch roller 16 is pressed against the platen roller 14, and the heating element of the ink sheet 12 is 13
The recording start position of the first color yellow ink comes at the position facing a, and the thermal head 13 and the ink sheet 1
2, and the sheet guides 21 and 22 are separated from the platen roller 14 (13 ', 12', and 21 ', 22'). When recording is started, the thermal head is
13 and the sheet guides 19 and 20 are integrally moved in the direction of the arrow d so that the heating element 13a is attached to the ink sheet 12 and the image receiving paper 11.
It is pressed against the platen roller 14 via. Next, the heating element 13a corresponding to the image information for each line of yellow is heated to selectively heat the yellow ink to receive the image receiving paper 11.
Make a transcription on top. At the same time, the driving means 17 is driven in synchronization with the image information to rotate the platen roller 14 line by line in the direction of arrow e. At this time, the timing belt 28 drives the pinch roller pulley 27 to rotate in the direction of arrow f in order to rotate the pinch roller 16 at a higher speed than the pinch roller 15. However, in reality, the pinch roller shaft 16a is better than the pinch roller pulley 27. Since the pinch roller shaft 16a is rotating at a low speed in the arrow f direction, the pinch roller shaft 16a is relatively rotating in the arrow c direction with respect to the pinch roller pulley 27, and the pinch roller shaft 16a is rotated by the clutch mechanism. It is released from the rotational driving force of the pulley 27. Therefore, the pinch roller 15 and the focus roller 16 are the platen rollers 14
Following the rotation of, the rotation is performed in the arrow g direction and the arrow f direction, respectively. However, at this time, the image receiving paper 11 is conveyed at the pressure contact position of the pinch roller 15 more strongly and at a higher speed than the pressure contact position of the pinch roller 16. This is because the two pinch rollers have the same material and shape and the pressure contact force of the pinch roller 15 is stronger than the pressure contact force of the pinch roller 16.
This is because the rubber layer on the surface of the platen roller 14 at the pressing position of 15 receives a larger shear strain and expands, the apparent peripheral length becomes longer, and the conveying speed of the image receiving paper 11 becomes faster. Furthermore, the larger the pressure contact force, the greater the frictional force between the platen roller 14 and the image receiving paper 11, and the stronger the conveying force of the image receiving paper 11. In this way, the image receiving paper 11 is conveyed in accordance with the rotation speed of the pinch roller 15 having a sufficiently strong pressure contact force,
On the upstream side, the platen roller 14 is pressed by the pressure contact force of the pinch roller 16.
As a result, the platen roller 14 receives a proper load due to friction between the platen roller 14 and the platen roller 14 and is conveyed in the direction of the regular length arrow h without slack. Further, the ink sheet 12 is conveyed in the direction of arrow i by the frictional force between the thermal head 13 and the platen roller 14 due to the frictional force with the image receiving paper 11, and is wound while applying tension by means not shown. When the recording for one page is completed with the yellow ink in this way, the driving means 17 is once stopped and the platen roller 14 is stopped, and the thermal head 13, the sheet guides 21 and 22 and the arrow guide j are moved by means not shown. Then, the thermal head 13 and the ink sheet 12 are separated from the platen roller 14. (States of 13 ', 21', and 22 ') After that, until the recording start position of the magenta ink of the second color comes to a position facing the heat generating element 13a of the ink sheet 12, the ink sheet 12 is moved by the arrow i by means not shown. Transport in the direction.
At this time, the driving means 17 is driven to rotate the platen roller 14 in the direction of arrow k. At this time, the timing belt 28 drives the pinch roller pulley 27 to rotate in the direction of arrow m in order to rotate the pinch roller 16 at a higher speed than the pinch roller 15.
It cannot rotate in the direction of arrow c at a higher speed, and the clutch mechanism 29 moves to rotate the pinch roller shaft 16a integrally with the pinch roller pulley 27. Therefore pinch rollers
The image receiving paper 11 conveyed in the arrow 1 direction at the pressing position of 15 is always given an appropriate tension in the arrow 1 direction by the frictional force with the pinch roller 16 rotating at a peripheral speed higher than the conveying speed, and the platen roller 14 Conveyed without slacking up. The image receiving paper 11 conveyed in this way is pulled back and conveyed by the same length as at the time of recording without sliding on the platen roller 14 at the position where the pinch roller 15 is pressed, and the platen roller 14 is always
Since it does not slacken up, the same position as before recording is accurately reproduced at the pressure contact position of the heating element 13a. In this way, the image receiving paper 11 is pulled back to the recording start position, and the recording start state of the magenta ink of the second color is set. Thereafter, the thermal head 13 and the ink sheet 12 are pressed against the platen roller 14 to record one page of magenta ink on the recorded image of yellow ink. In the same manner, recording with the third color cyan ink is performed, and recording of the color image by the subtractive color mixing method is completed.

As described above, according to the embodiment of the present invention, the image receiving paper 11
The platen roller 14 and the two pinch rollers 15 and 16 that press the platen roller 14 can be used as a simple conveying means. At the same time, the pressure contact position between the platen roller and the pinch roller, which is the pinching position of the image receiving paper, is set to the thermal head. Since they can be brought close to each other, the non-recording portion on the image receiving paper can be shortened, and moreover, the reciprocating amount of the image receiving paper 11 can be made the same to obtain a good color image with little color shift.

In this embodiment, the pinch rollers 15 and 16 are made of the same material and have the same shape, but if the conveying speed and the conveying force of the image receiving paper 11 at the pressure contact position of the pinch roller 15 are sufficiently larger than the pinch roller 16, different materials are used. ， It may be shaped.

Further, in this embodiment, a bearing mechanism is used as the clutch mechanism of the pinch roller 16, but the same effect can be obtained by using a ratchet mechanism or the like instead.

Further, in this embodiment, the platen roller drive system was used as the pinch roller drive means, but it goes without saying that another drive source may be used.

Further, although the thermal head 13 is of the line type in this embodiment, a serial type may be used.

In addition, in this embodiment, the ink recording order is yellow, magenta, and cyan, but it may be another order, and the ink type is three colors, but needless to say, it may be other than three colors.

EFFECTS OF THE INVENTION According to the present invention, the image receiving sheet conveying means has a simple structure including a platen roller and two pinch rollers pressed against the platen roller.
In addition, the pressure contact position between the platen roller and the pinch roller, which is the nipping position of the image receiving paper, is brought closer to the recording means to shorten the non-recording portion on the image receiving paper, and when pulling back, only the pinch roller on the upstream side follows the platen roller and rotates. , The downstream pinch roller is rotated at a higher peripheral speed than the upstream pinch roller to prevent the image receiving paper from slacking on the platen roller and improve the transfer accuracy of the image receiving paper. Images can be obtained.

[Brief description of drawings]

FIG. 1 is a side view showing the basic structure of a color recording apparatus according to an embodiment of the present invention, and FIG. 2 is a side view showing the basic structure of a conventional color recording apparatus. 11 ... Image receiving paper, 12 ... Ink sheet, 13 ... Thermal head, 14 ... Platen roller, 15, 16 ... Pinch roller, 17 ... Driving means, 19, 20, 28 ... Timing belt,
27 …… Pinch roller pulley, 29 …… Clutch mechanism.

Claims (1)

[Claims] 1. A platen roller which winds a part of an image receiving paper around the circumference and is driven to rotate in forward and reverse directions at the time of recording and pulling back, respectively, and at the time of recording, it is pressed against the platen roller through the image receiving paper and pulled back. And a pair of pinch rollers that are in pressure contact with the platen roller via the image receiving paper at two locations on the upstream side and the downstream side of the recording means on the image receiving paper conveyance path. After the pinch roller, the pressure contact force of the downstream pinch roller at the time of recording is always stronger than the pressure contact force of the upstream pinch roller at the time of recording. A pinch roller driving unit that rotates at a peripheral speed higher than that of the upstream pinch roller that rotates following the platen roller, and a club that is effective only when the pinch roller driving unit is pulled back. A pinch mechanism, both of the pinch rollers rotate following the platen roller during recording, but the downstream pinch roller conveys the image receiving paper faster than the upstream pinch roller due to the difference in pressure contact force. Color recording in which only the upstream pinch roller that drives and feeds the image receiving paper when it is pulled back rotates following the platen roller, and the downstream pinch roller rotates at a faster peripheral speed than the upstream pinch roller. apparatus.