JPS62144975A - Color recorder - Google Patents

Abstract

PURPOSE:To enhance accuracy of feeding and reduce misregistration of colors, by rotating a pinch roller on the downstream side at a circumferential velocity higher than that of a pinch roller on the upstream side which is rotated following up a platen roller, at the time of a feeding-back operation. CONSTITUTION:A pinch roller pulley 27 and a timing belt 28 constitute a pinch roller driving means for rotating a pinch roller 16 at a circumferential velocity higher than that of a pinch roller 15 rotated following up a platen roller 14. A clutch mechanism 29 transmits a driving force of the pinch roller pulley 27 for the pinch roller 16 only at the time of a feeding-back operation. An image-receiving paper 11 is fed back by a length by which it is fed forward during recording, without slipping relative to the platen roller 14 at the pressing position of the pinch roller 15, and it does not sag on the platen roller 14. Accordingly, the same position of the paper 11 as that located at the pressing position of heat generating elements 13a before recording can be located again at the pressing position of the elements 13a with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a color recording device that is compact and capable of easily obtaining high-quality images, useful for hard copies of full-color images such as television images and captain systems. be.

2. Description of the Related Art In recent years, there has been a remarkable trend toward color display devices such as CRTs, and with this trend, there has been a demand for note copy devices capable of recording in color. Among these, the thermal transfer method is attracting attention as it plays a role in the colorization of many terminal printers, including office automation equipment, because it is quiet and easy to maintain.

Generally, when performing color recording using a thermal transfer method,
As shown in FIG. 2, while conveying the ink sheet 2 and the image receiving paper 1 on which each color surface is sequentially coated with ink in the direction of arrow a,
A thermal head 3 in which heat generating elements 3a are linearly arranged is connected to a platen roller 4 via this ink sheet 2 and image receiving paper 1.
is pressed to cause the heating elements to generate heat according to image information for one line of each color, thereby recording by thermal transfer. In this way, after recording one page with the ink of the - color, the receiver paper 1 is pulled back in the direction of the arrow so that the recording start position is at the thermal head section, and then one of the two-color inks is Recording for one page is performed, and in the same manner, recording for one page of the three-color mouth is performed to record a color image using the subtractive color mixing method. Conventionally, the image-receiving paper 1 is held between pinch rollers 6 and 6 in pressure contact with the platen roller 4, and is conveyed back and forth by driving the platen roller 4 to rotate with a drive means 7.

Problems to be Solved by the Invention However, with such a method, the image receiving paper 1 is conveyed at two pressure contact points, the pinch roller 6 and the platen roller 4, and the pressure contact conditions at these two locations cannot be accurately matched. The conveyance amount of the image receiving paper 1 at both pressure contact points is different. If the image-receiving paper 1 is loose because it is not wrapped around the platen roller 4, the image-receiving paper 1 may slip on the platen roller 4 at the pressure contact point of either pinch roller, and the recording means 3 and the platen roller 4 may come into pressure contact with each other. receiver paper 1 in position
This has the disadvantage that it is difficult to obtain accurate positional reproducibility, resulting in color shift.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a system in which the downstream pinch roller of the two pinch rollers is selected from the upstream pinch roller that rotates following the platen roller. A pinch roller driving means for rotating at a high circumferential speed and a clutch mechanism for making the pinch roller driving means effective only when pulling back are provided, and during recording, both of the pinch rollers are rotated following the platen roller, When pulling back, only the pinch roller on the upstream side rotates following the platen roller, and the pinch roller on the downstream side rotates at a faster peripheral speed than the pinch roller on the upstream side. This allows the deviation to be reduced.

According to the above-described structure, the present invention simplifies the image-receiving paper conveyance means by only the platen roller and a pair of pinch rollers that are in pressure contact with the platen roller. Since the 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 is rotated following the platen roller, and the downstream pinch roller is configured to rotate at a faster circumferential speed than the upstream pinch roller. It is possible to prevent the paper from loosening on the platen roller, improve conveyance accuracy, and reduce color misregistration.

Embodiment Hereinafter, the configuration of an embodiment of the present invention will be explained based on the accompanying drawings.

FIG. 1 is a basic configuration diagram of a color recording apparatus in an embodiment of the present invention. In Fig. 1, 11 is image receiving paper, 12
1 of each color is coated with ink that becomes fluid when heated on the surface facing the image receiving paper 11 on a support such as a PET film.
The ink sheet is colored sequentially in yellow, magenta, and cyan for each page, and 13 is the heating element 13! L to receiver paper 1
Line-type thermal heads arranged linearly in the width direction of 1; 14 is a platen roller around which a part of the image receiving paper 11 is wound; 16 and 16 are made of the same material and are in pressure contact with the platen roller 14 through the image receiving paper 11; This is a pinch roller with the same shape.

17 is a driving means such as a step motor that rotates the platen roller 14 in both directions; 18 is an intermediate pulley; 19 and 2o are timing belts; , constitutes a driving force transmitting means for transmitting to the chimney pulley 14&. Further, 21 and 22 are sheet guides that operate integrally with the thermal head 13 and guide the ink sheet 12; 23 is a pinch row 2 support member that rotatably supports the pinch roller shaft 162L and rotates around the fixed shaft 231L; 24 is a pinch roller support member that rotatably supports the pinch roller shaft 161L and rotates around the fixed intermediate pulley shaft 1B&; 26 is the pinch roller 16;
A tension coil spring 26 is stretched between the pinch roller support member 23 and the national body (not shown) so that the pinch roller 16 is in pressure contact with the platen roller 214.
A tensile coil panel is stretched between the pinch roller support member 24 and the national body (not shown) so as to be in pressure contact with the platen roller 4, and is configured so that the pressure of the pinch row 216 on the platen roller 14 is stronger than the pressure force of the pinch roller 16. It is. 2
7 is a pinch roller pulley, 2B is a timing belt that transmits the rotational force of the intermediate pulley 18 to the pinch roller pulley 27, and 29 is a timing belt that is fixed to the pinch roller pulley 27 and connects the pinch row 2 shaft 16a to the pinch roller pulley 27. This is a clutch mechanism such as a one-sided clutch that is rotatably supported only in the direction of arrow C.

Here, the pinch roller pulley 27 and the timing belt 28 constitute a pinch roller driving means that rotates the pinch row 216 at a peripheral speed faster than the peripheral speed of the pinch row 215 that rotates following the platen roller 14. Pinch roller 1 of pinch roller pulley 27
6 is transmitted only when pulling back.

Next, the operation of the color recording apparatus in this example will be explained in the first section.
Explain using diagrams. Before recording starts, the image receiving paper 11 is in close contact with the platen row 214 between the position where the pinch roller 16 presses against the platen roller 14 and the position where the pinch roller 16 presses against the platen roller 14, and the ink sheet 1
The recording start position of the negative color yellow ink is at the position facing the heating element 13& of the thermal head 13&. Ink sheet 12 and sheet guide 21.2
2 is in a state separated from the platen roller 14 (13',
12', and 21', 22').

At the start of recording, the thermal head 13 and sheet guides 19 and 20 are integrally moved in the direction of arrow d by means not shown, and the heating element 13 & is moved onto the ink sheet 12.
The image receiving paper 11 is then brought into pressure contact with the platen roller 14 . Next, the heating elements 13& are made to generate heat in accordance with the image information for each line of yellow, thereby selectively heating the yellow ink and transferring it onto the image receiving paper 11. 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 rotates the pinch roller pulley 27 in the direction indicated by the arrow in order to rotate the pinch roller 16 at a higher speed than the pinch roller 16, but in reality, the pinch roller shaft 161L is faster than the pinch roller pulley 2.
7, the pinch roller shaft 161L is relatively rotating in the direction of arrow C with respect to the pinch roller pulley 27, and the pinch roller shaft 16 is connected to the clutch mechanism. Therefore, it is released from the rotational driving force of the pinch roller pulley 27.

Therefore, the pinch roller 15 and the pin row 216 follow the rotation of the platen roller 14 and rotate in the direction of arrow g and the direction of arrow f, respectively. However, at this time, the image-receiving paper 11 is conveyed more forcefully and at a higher speed at the position where the pinch roller 16 is in pressure contact than at the position where the pinch roller 16 is in pressure contact.

This is because the two pinch rollers are made of the same material and have the same shape, and the pressure contact force of the pinch roller 16 is stronger than the pressure contact force of the pinch roller 16. Therefore, the rubber layer on the surface of the platen roller 14 at the pressure contact position of the pinch roller 16 is stronger than the pressure contact force of the pinch roller 16. This is because the image-receiving paper 11 is expanded due to the larger shear strain, and the apparent circumference becomes longer, thereby increasing the conveyance speed of the image-receiving paper 11. Furthermore, the platen roller 14 and the image receiving paper 1 have a larger pressure contact force.
Since the frictional force of the image receiving paper 11 is large, the conveyance force of the image receiving paper 11 is also strong. In this way, the image-receiving paper 11 is conveyed according to the rotational speed of the pinch roller 150, which has a sufficiently strong pressure contact force, and is subjected to a moderate load due to friction with the platen roller 14 due to the pressure contact force of the pinch row 216 on the upstream side. , the paper is conveyed along the normal length in the direction of the arrow without loosening on the platen roller 14. Further, the ink sheet 12 is conveyed in the main direction of the arrow by frictional force with the image-receiving paper 11 at a position where the thermal head 13 and the platen roller 14 are in pressure contact, and is wound up while applying tension by means not shown. When one page of recording is completed using the yellow ink in this way, the driving means 17 is temporarily stopped, the platen roller 14 is stopped, and the thermal head 13 is moved by means (not shown).
．． The thermal head 13 and the ink sheet 12 are separated from the platen row 214 by moving the sheet guides 21 and 22 in the direction of the arrow j. (13', 21' and 2
2' state) After this, the heating element 13 of the ink sheet 12
The ink sheet 12 is conveyed in the direction of arrow i by means not shown until the recording start position of the second color magenta ink comes to a position opposite to 1L. At this time, the driving means 17 is driven to rotate the platen roller 14 in the direction of the arrow. At this time, the timing belt 28 rotates the pinch roller pulley 27 in the direction of arrow m in order to rotate the pinch roller 16 at a higher speed than the pinch roller 16, so the pinch roller shaft 16& is rotated by the pinch roller pulley 27.
It is not possible to rotate at a higher speed in the direction of arrow C.

As the clutch mechanism 29 moves, the pinch roller shaft 162L is rotated integrally with the pinch roller pulley 27. Therefore, the image receiving paper 11 being conveyed in the direction of arrow 1 at the pressure contact position of the pinch roller 16 is always given an appropriate tension in the direction of arrow 1 due to the frictional force with the pinch row 216 which rotates at a peripheral speed faster than the conveyance speed.

It is conveyed without slack on the platen row 214.

The image-receiving paper 11 conveyed in this manner is pulled back and conveyed by the same length as during recording without slipping on the platen roller 214 at the position where it comes into pressure contact with the pinch roller 16, and moreover, because it does not always loosen on the platen roller 14, the heating element 131L Accurately reproduce the same pressure position as before recording. In this way, the image receiving paper 11 is pulled back to the recording start position,
The second color magenta ink starts recording. Thereafter, the thermal head 13 and the ink sheet 12 are pressed against the platen row 214 to record one page of magenta ink on the yellow ink record image. Thereafter, recording is performed using the third color cyan ink in the same manner, thereby completing the recording of a color image using the subtractive color mixing method.

As described above, according to the embodiment of the present invention, the image receiving paper 1
The conveying means of No. 1 is pressed against the platen roller 14.
It has a simple configuration with two pinch rollers 16 and 16, and at the same time, the pressure contact position of the platen roller and pinch roller, which is the position where the image-receiving paper is held, can be brought closer to the thermal head, so the non-recording area on the image-receiving paper can be shortened. Moreover, the amount of reciprocating transport of the image receiving paper 11 is kept the same,
A good color image with little color shift can be obtained.

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

Further, in this embodiment, a bearing-like clutch mechanism is used as the clutch mechanism for 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 drive system of the platen row 2 is used as the pinch roller drive means, but it goes without saying that other drive sources may be used.

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

In addition, in this embodiment, the ink recording 113 is made of yellow, magenta, and cyan, but a different order may be used, and although the types of ink are three colors, it goes without saying that colors other than the three colors may be used.

Effects of the Invention In the present invention, the image receiving paper conveyance means has a simple structure consisting of a platen roller and two pinch rollers that press against the platen roller.
In addition, the pressure contact position of the platen roller and pinch roller, which is the position where the image receiving paper is held, is moved closer to the recording means to shorten the non-recording area on the image receiving paper, and when pulling back, only the upstream pinch roller rotates to follow the platen roller. The pinch roller on the downstream side is configured to rotate at a faster peripheral speed than the pinch roller on the upstream side, which prevents the receiving paper from loosening on the platen roller and improves the conveyance accuracy of the receiving paper, resulting in good color with less color shift. You can get the image.

[Brief explanation of drawings]

FIG. 1 is a side view showing the basic configuration of a color recording apparatus according to an embodiment of the present invention, and FIG. 2 is a side view showing the basic configuration of a conventional color recording apparatus. 11... Receiving paper, 12... Ink sheet, 13... Thermal head %14...
・Platen roller, 15.18... Pinch roller, 17... Drive means, 19.2Q, 2B...
...Timing belt, 27...Pinch roller pulley, 29...Clutch mechanism. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 11
1

Claims (2)

[Claims] (1) A platen roller that wraps a part of the image-receiving paper around its circumference and drives it to rotate in forward and reverse directions during recording and when pulling back, and a platen roller that presses against the platen roller through the image-receiving paper during recording and when pulling back. a pair of pinch rollers that press against the platen roller through the image receiving paper at two locations on the image receiving paper conveyance path, upstream and downstream with respect to the recording means; a pinch roller driving means for rotating a downstream pinch roller at a faster circumferential speed than an upstream pinch roller that rotates following the platen roller when pulling back; and a clutch mechanism that makes the pinch roller driving means effective only when pulling back. During recording, both pinch rollers rotate following the platen roller, and when pulling back, only the upstream pinch roller rotates following the platen roller, and the downstream pinch roller rotates following the platen roller. A color recording device configured to rotate at a faster circumferential speed than a pinch roller. (2) The color recording apparatus according to claim 1, wherein the pinch roller driving means uses the rotational driving force of the platen roller.