JPH06122262A - Ink sheet drive system - Google Patents

Abstract

(57) [Summary] [Object] With regard to an ink sheet driving method in a transfer recording apparatus, an object thereof is to provide a low cost ink sheet driving method that stabilizes the tension of the ink sheet at the time of transfer regardless of the winding diameter. To do. A spool is constituted by time information obtained by detecting the discrimination marks 15, 16 and 17 provided on the starting end portion of each color divided into a plurality of colors on an ink sheet 10 by a detection means 20 and distance information obtained from a print signal. An ink sheet driving method in which a winding diameter of 40 is calculated, and an appropriate driving torque is applied to the driving unit 30 that conveys the ink sheet 10 by the control unit 50.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink sheet driving system in a transfer recording system for forming characters and images on paper.

[0002]

2. Description of the Related Art Generally, a transfer recording apparatus superimposes an ink application surface of an ink sheet on a sheet at a transfer section and selectively transfers the ink applied on the ink sheet to the sheet by heat or electric energy for recording. To do. At this time, the ink sheet is taken up from one spool via the transfer section to the other spool at a constant speed. However, when the winding diameter of the spool on the take-up side becomes large, the winding speed of the ink sheet increases with the increase of the winding diameter of the spool, even though the speed of the ink sheet sent from the transfer unit is constant, and There is a problem that the tension of the ink sheet becomes unstable due to the deviation between the sheet winding speed and the sheet conveying speed.

A solution to this problem is shown in FIG.
As described in Japanese Unexamined Patent Publication No. 0-58363, a slip mechanism composed of a spring 3 or the like that constantly presses the slip ring 1 and the flange 2 is provided, and the rotation speed of the ink sheet 4 and the rotation speed of the drive pulley 5 are The one that absorbs the difference was adopted.

[0004]

Since the conventional ink sheet driving device described above is provided with the slip mechanism, there is a drawback that the cost is increased by increasing the number of parts. There is also known a method in which a DC motor is used to wind an ink sheet on a spool without providing a slip mechanism, but in this case, the torque of the motor fluctuates in response to a change in the winding diameter, resulting in stable operation. There is a drawback that the tension of the ink sheet cannot be obtained and the print quality is adversely affected.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks and to provide a low cost ink sheet driving system which stabilizes the tension of the ink sheet during transfer regardless of the winding diameter.

[0006]

The above object is to detect the time from the completion of printing of each color of an ink sheet of at least two colors to the detection of the discrimination mark of the next color, and to correspond to the time from the print signal. The distance of the moved ink sheet, calculate the ink sheet feed speed and the winding diameter of the spool on the take-up side from these values, and control to give a torque to the motor according to the winding diameter. It is achieved by the ink sheet driving method.

[0007]

According to the above-mentioned ink sheet driving method, the time from the end of printing of each color of the ink sheet to the detection of the discrimination mark of the next color, that is, the time from the end of printing to the heading of the ribbon of the next color is detected, The distance from the end of printing to the head of the next color ribbon is obtained from the print signal, the feed speed of the ink sheet and the winding diameter are calculated from these information, and the control unit applies a torque adjusted to the winding diameter to the motor. By feeding the ink sheet, an appropriate torque is applied to the motor, and the tension of the ink sheet is kept constant regardless of the winding diameter of the spool.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a side view showing an embodiment of the present invention, 10 is an ink sheet, 20 is a detection means for detecting the discrimination marks 15, 16, 17 for discriminating the color of the ink sheet 10,
Reference numeral 30 is a DC motor for winding the ink sheet 10 on the winding side spool 40, and 50 is a DC motor 30 based on data calculated from time information and distance information output from the detection means 20 and a print signal or the like. Is a control unit for applying a torque according to the winding diameter of the winding-side spool 40. The ink sheet 10 wound in a roll shape is conveyed in the D direction via a transfer unit 80 including a line type thermal head 60 and a platen 70, and is wound on the winding side spool 40. When transferring the ink to the paper 90, the ink selected corresponding to the reciprocating motion of the paper 90 is cued and transferred to the paper by the heat generated by the heating resistor portion 61 of the thermal head 60. It is well known that the process is repeated for desired plural colors.

Next, the operation of this embodiment will be described in detail with reference to the time chart of FIG. The ink sheet 10 is coated with three primary colors (Y color 12, M color 13, C color 14) in a predetermined area, pitch, and order in the feeding direction (D direction),
A black mark 1 is provided at the beginning of each divided color.
It has 5, 16, and 17. Further, the detection means 20 is installed at the position where the discrimination marks 15, 16 and 17 pass, and the signal is turned on when the Y color 12, M color 13 and C color 14 are detected, and turned off when the discrimination marks 15, 16 and 17 are detected. Is set.

For example, when printing the specified length A,
First, the print signal is turned on while the thermal head 60 is in pressure contact with the platen 70, and the first Y-color 12 is printed. Next, the thermal head 60 is released from the platen 70 at the same time when the print signal of the Y color 12 is turned off, and the DC motor 30 is used to locate the second color of the M color 13.
Thus, the ink sheet 10 is conveyed. At this time, paper 9
As described above, 0 is also inverted and positioned at the same position as the print start position for the first color.

Here, the length from the printing end portion of the Y color 12 on the ribbon 10 to the discrimination mark 16 of the M color 13 is L _1, and the time when the detecting means 20 detects the length of L ₁ is t.
_When the value is ₁ , the value obtained by dividing L ₁ by t ₁ is the ink sheet feed speed. Since the distance L ₀ from the start end of the Y color 12 to the print start part does not change from print to print and is constant,
L ₁ is obtained by subtracting L ₀ and the printing distance A from the Y color 12 distance. The same applies to other colors. The measurement of t ₁ is obtained from the value counted by the reference clock in the control unit 50. From the print end of the second M color 13 to C color 14
The distance L ₂ to the discrimination mark 17 and the detection time t ₂ by the detection means 20, and the distance L ₃ from the printing end portion of the third C color 14 to the discrimination mark 15 of the Y color 12 and the detection time t ₃ The feeding speed of the ink sheet 10 is obtained from each of the above.

From these information, the spool 40 on the take-up side
The winding diameter is calculated by the control unit 50, but it goes without saying that the torque characteristics of the DC motor 30 to be used, the load force of the transport system for the ink sheet 10 and the like are taken into consideration at this time. Further, the three values of the feed speed of the ink sheet 10 obtained from the detection times t ₁ , t ₂ , and t ₃ may vary due to differences in the load force of the transport system of the ink sheet 10, but By using the average value, the winding diameter of the winding side spool 40 can be accurately obtained. In this way, the proper torque of the DC motor 30 at the time of printing can be set from the value of the winding diameter of the spool 40 calculated when the thermal head 60 is released. The method of changing the torque for controlling the DC motor 30 is performed by providing a pulse generation circuit in the control unit 50 and changing the energization time of the voltage applied to the DC motor 30.

Next, the circuit of the control unit 50 will be described.
51 is a CPU, 52 is a reference clock oscillator, 53 is a pulse generation circuit, 54 is an AND circuit, and 55 is a DC motor 3
0 ON / OFF circuit. The output pulse width in the pulse generation circuit 53 is determined by the reference clock oscillator 52.
And the setting value is input from the CPU 51. The output pulse from the pulse generation circuit 53 is input to the AND circuit 54 together with the ON / OFF circuit 55 of the DC motor 30, and the energization time of the DC motor 30 can be determined. Further, the torque of the DC motor 30 when the thermal head 60 is released from the platen 70 and the ink sheet 10 is conveyed (when the above-described detection times t ₁ , t ₂ , and t ₃ are detected) is determined by the winding side spool 40 winding diameter. It goes without saying that it is constant regardless of

The operation of measuring the time from the end of printing of each color of the ink sheet to the detection of the discrimination mark of the next color and controlling the torque of the ink sheet spool on the take-up side is carried out for each sheet of paper to be printed. can do. However, there is no problem even if it is carried out for every specified number of sheets counted from the time the power of the apparatus is turned on.

[0015]

According to the present invention, the detection means detects the discrimination mark which is divided into a plurality of colors in the feeding direction of the ink sheet and is provided at the starting end portion of each color, and the time information output by the detection means and the print signal. Also, since a control unit for applying an appropriate drive torque to the motor that conveys the ink sheet based on the distance information is provided, the tension of the ink sheet at the time of printing is simple regardless of the winding diameter of the spool with a simple configuration and at low cost. Can be kept constant.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of an ink sheet driving system according to the present invention.

FIG. 2 is a time chart showing the operation of the embodiment shown in FIG.

FIG. 3 is a block diagram showing a circuit of a control unit of the embodiment shown in FIG.

FIG. 4 is a diagram showing a conventional ink sheet drive system.

[Explanation of symbols]

10 is an ink sheet, 15, 16 and 17 are discrimination marks,
20 is a detector, 30 is a DC motor, 40 is a spool, 5
Reference numeral 0 is a control unit, 80 is a transfer unit, and 90 is a sheet.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keiji Kunimi 1060 Takeda, Katsuta City, Ibaraki Prefecture Hitachi Koki Co., Ltd.

Claims (1)

[Claims] 1. An ink sheet wound in a roll shape, which has at least two colors and has a discrimination mark for each color, is wound by a drive means from one spool to a spool on a winding side via a transfer section. In a transfer color printer that records multiple colors on paper, it is obtained from the time information and print signal obtained by detecting the time from the end of printing each color of the ink sheet to the detection of the next color discrimination mark. An ink sheet driving method in which the winding diameter of the spool on the winding side is calculated from the distance information, and control is performed so that a torque corresponding to the winding diameter is applied to the driving means.