JPH03178472A - Thermal transfer color printer - Google Patents

Abstract

PURPOSE:To miniaturize the device and reduce the cost by providing a consitution in which one of ink layers is identified to allow a heading action using a signal from a photosensor which outputs a detection signal when a light of specified wavelength originating from a light source passes through each ink layer. CONSTITUTION:An insulating or a yellow light emitting LED 10 which emits a light with wavelengths of 540 to 590 nm and a phototransistor 11 which is a light-receiving element are arranged near a platen 1 through an ink sheet 6. This phototransistor 11 outputs a detection signal when a green(or a yellow) light(having peak wavelengths of 540 to 590 nm) emitted from a green(or a yellow) light emitting LED 10 to an ink sheet 6, transmits an ink layer and then is received by the phototransistor 11. This detection signal is amplified using emplifiers 12,13 and an ink identification device 14 identifies one of the ink layers to allow its heading.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention is directed to heating an ink sheet in which a plurality of ink layers are provided in a predetermined color order as a set in a thermal/decoder to obtain a desired color. The present invention relates to a thermal transfer color printer applied to a video printer or the like that records (prints) images, characters, etc. on recording paper.

(b) Prior Art This type of color printer device has a structure in which an attached ink sheet is continuously run between a platen and a thermal head. On the other hand, on the ink sheet, for example,
As shown in Figure 'i57, a yellow ink layer Y, a magenta ink layer M, and a cyan ink layer C are set as one set, and these ink layers are provided in this color order. Therefore, when seven portions of the yellow ink layer of the ink sheet are pressed against the recording paper and the ink sheet is heated by the thermal head, the yellow ink is first printed on the recording paper.

Next, the magenta ink layer X1 portion and the cyan ink layer C portion of the ink sheet are sequentially pressed and heated by a thermal head each time they are pressed, so that magenta ink and cyan ink are superimposed and printed on the recording paper.

By the way, in order to perform the above-mentioned overlapping printing, etc., it is necessary to discriminate each ink layer in order to position (cue) each ink layer at the printing position. Therefore, conventionally, Japanese Patent Application Laid-Open No. 63-231976
As shown in FIG. 7, a barcode 14 for cueing is provided corresponding to the end of the yellow ink layer Y, which is the tip of the set of ink sheets, and an optical sensor detects the barcode 1.
(c) Problems to be Solved by the Invention However, as in the past, barcodes 14 and 14 were used to detect the printing position in order to cue up the printing position in correspondence with the yellow ink layer Y. If the barcode 14 is provided, the width of the ink sheet must be increased by the amount of the barcode 14, and a coloring and coating process for providing the barcode 1 is required. Therefore, the manufacturing cost of the ink sheet increases and the ink sheet becomes expensive.

[2) Means for Solving the Problems The color printer according to the present invention includes an ink sheet in which ink layers of a plurality of colors are provided as a set in a predetermined color order, and heating the ink sheet with a thermal head. In a thermal transfer color printer that performs color printing on recording paper through the ink layers of each color, the light source irradiates each ink layer with light with a wavelength of 540 to 590 nm, and the light from the light source is transmitted through each ink layer. The apparatus is comprised of an optical sensor that outputs a detection signal when the optical sensor is turned on, and an ink layer discriminating means that discriminates one of the ink layers and locates the beginning of the ink layer based on the detection signal of the optical sensor.

(E) Function According to the present invention, a light source that irradiates each ink layer with light having a wavelength of 540 to 590 nm, a light sensor that outputs a detection signal when the light from the light source passes through the ink layer, and a light sensor that outputs a detection signal when the light from the light source passes through the ink layer; Since the apparatus includes an ink layer discriminating means for discriminating and locating one of the ink layers based on the detection signal of the sensor, the ink sheet can be made smaller and furthermore inexpensive.

(F) Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The thermal transfer color printer device according to the present invention includes a platen 1, as shown in FIG.

A clamper 2 for clamping the recording paper 3 is disposed on a part of the outer peripheral surface of the platen l, and when the recording paper 3 arrives at a predetermined position, the clamper 2 clamps the recording paper 3.

A thermal head 5 is arranged above the platen 1 and is controlled by an energization control section 4 as described later. The thermal head 5 is fixed to a mounting base (not shown), and is pressed against the outer circumferential surface of the platen 1 via the ink sheet 6 by the swinging of the mounting base. The used portion of the ink sheet 6 is taken up by a take-up reroller 7. The take-up reroller 7 is rotated by a motor 8 via a speed reduction mechanism (not shown).The unused roll-shaped ink sheet 6 is attached to a supply roller 9, and the supply roller 9 is driven by the rotation of the take-up roller 7. The ink sheet 6 is supplied by driven rotation.

Now, near the platen l, there is a green or yellow light emitting LED 10 that emits light with a wavelength of 540 to 590 nm, and a phototransistor 1 that is a light receiving element through an ink sheet 6.
1 (or photodiodes) are arranged in pairs. This phototransistor 11 emits green (or yellow) light irradiated onto the ink sheet 6 from a green (or yellow) light emitting LEDIO (as can be seen from the spectrum distribution diagram in FIG. 5, the peak wavelength has a wavelength of 540 to 590 nm).
When the light passes through the ink layer of the ink sheet 6 and is received by the phototransistor 11, a detection signal is output. This detection signal is amplified by amplifiers 12 and 13, and the ink layer discriminating means 14 discriminates one of the ink layers and cues the ink layer.

Here, the spectral sensitivity characteristic of the phototransistor 11 is the third
It will look like the figure. The Si phototransistor lla used in this example has a peak at approximately 900 nm, and
GaAsP phototransistor llb has a peak at approximately 600 nm.

In addition, the phototransistors lla and llb described above each change from the long wavelength side to the short wavelength f in the visible range up to the peak value.
This is a phototransistor that increases approximately linearly with respect to f111.

On the other hand, as shown in FIG. 2, the ink sheet 6 is provided with a large number of ink layers, each consisting of a yellow ink layer Y, a magenta ink layer M, and a cyan ink layer C, in this order. Further, the length l from one ink layer to the next ink layer is approximately the same length.

Further, the barcode 14 that was conventionally provided is not provided at the end of the ink sheet 6, and therefore the width of the ink sheet 6 is small.

Further, the length of the ink sheet 6 in the running direction can be the same as the conventional one, and the number of ink layers can be increased.

Incidentally, when the yellow ink layer Y, the magenta ink layer M, and the cyan ink layer C transmit equal spectrum white light, each of them has transmittance spectral characteristics as shown in FIG. 4.

Therefore, when green (or yellow) light from a green (or yellow) emitting LEDIO with a peak wavelength of 540 to 590 nm is transmitted through each ink layer, the yellow ink layer Y will be approximately 80%
In contrast, only about several percent of the light passes through the magenta ink layer M and the cyan ink layer C. this is,
In the wavelength range of 540 to 590 nm, magenta ink layer Y
This is because the curve of the cyan ink layer C corresponds to the valley part.

When the transmitted light is received by the phototransistor 11, a different detection signal (voltage) is output for each ink layer, and is amplified by the amplifiers 12 and 13. According to experiments and measurements, the voltage at Tpl in Figure 1 is the voltage obtained by light transmitted through the transparent ink sheet. (mV) 10
If 0, yellow ink layer Y, magenta ink layer M
, VM, V, which are obtained by the light transmitted through the cyan ink layer C, are shown in Table 1.

Table 1 As can be seen from Table 1, there is a sensitivity difference of more than 10 times between the output voltages of VY vs. V, V, and VC, respectively, so it can be seen that sufficient detection ability is provided.

Next, the operation of the thermal transfer type color printer device of the present invention will be explained together with the operation of the ink layer discriminating means 14.

First, the ink layer discriminating means 14 outputs a drive signal to the motor 8 and rotates the take-up roller 7, so that the ink sheet 6 is fed out from the supply roller 9 and runs. On the other hand, the edge color (or yellow) light emitting LEDIO emits green (or yellow) light toward the ink layer of the ink sheet 6. Therefore, as shown in FIG. 1, when the green (or yellow) emitting LED is moved from the end of the cyan ink layer C of the ink sheet 6 to the tip of the yellow ink layer Y, the cyan ink layer Since the light that was almost opaque to the yellow ink layer Y passes through the yellow ink layer Y, the phototransistor 11 outputs a detection output. This output changes from the 7 mV state to the 74 mV state via the amplifier 12.13 as shown in Table 1. This change is detected by the ink layer discriminating means 14, and as a result, it is determined that it is a yellow ink layer Y, and a stop signal is output to the motor 8 to position (cue) the yellow ink layer Y at the printing start position, and the winding is carried out. The rotation of the reroller 7 is temporarily stopped. Next, the thermal head 5 is pressed against the platen and a drive signal is output to the energization control section 4. As a result, the energization control unit 4 receives a yellow signal from a memory (not shown), and the thermal head 5
energize the heating element. As a result, the yellow ink layer Y of the ink sheet 6 is heated and yellow ink is printed on the recording paper 3.

Thereafter, the pulse motor (not shown) of the platen 1 and the motor 8 of the take-up roller 7 are rotated to continue the printing operation. Although not shown in this embodiment, the number of pulses corresponding to the length of the unexpected ink layer is set in the ink layer determining means 11, and the number of pulses corresponding to the length of the pulse motor of the platen 1 is counted to determine this number. Compare the count value and set value. When the count value and the set value match, it is determined that the second magenta ink layer M has moved to the printing start position, and a stop signal is output to the motor 8. next,
The thermal head 5 is separated, the pulse motor of the platen 1 is rotated to align the recording paper 3 to a predetermined printing start position, and the thermal head 5 is pressed against the platen 1. Also,
The count value is noset. Therefore, after that, the pulse motor of the platen L and the motor 8 are rotated, and magenta ink is superimposed and printed on the recording paper 3 via the magenta ink layer M.

The number of driving pulses for the platen 1 is supplied to the ink discriminating means 14 as the overlapping printing of the magenta ink layer M progresses. When the drive pulse count value and the set value match again, the ink layer determining means 14 determines that the third cyan ink layer C has moved to the printing start position, and outputs a stop signal to the motor 8. Furthermore, at this time, the thermal head 5 is separated, the pulse motor of the platen 1 is rotated to align the recording paper 3 to a predetermined printing start position, and the thermal head 5 is pressed against the platen 1.

Therefore, after that, the pulse motor of the platen 1 and the motor 8 of the take-up reroller 7 are rotated, and cyan ink is superimposed and printed on the recording paper 3 via the cyan ink layer C.

Here, the ink layer discrimination means 14 may be tilted by a microcomputer or a comparator, and as shown in Table 1, the ink layer discrimination means 14 is a circuit FfI that can distinguish between 7 mV and 74 mV.
! Anything is fine as long as it's true.

FIG. 6 shows another embodiment to which this embodiment is applied. As shown in the figure, a phototransistor 11 and a green (or yellow) light emitting LED are arranged on the same side, and the light is reflected to the opposite side through an ink sheet 6. This configuration includes a plate 22.

Note that a shielding plate 23 is provided between the green (or yellow) light emitting LEDIO and the phototransistor 11 to prevent reception of direct green (or yellow) light from the green (or yellow) light emitting LEDIO.

As a result, each voltage received is lower than that shown in Table 1, but since the phototransistor 11 and the green (or yellow) light emitting LED 10 can be placed on the same side, the height of the device can be reduced.

Furthermore, although the phototransistor 11 is used in this embodiment, a photodiode may also be used.

(G) Effects of the Invention According to the present invention, a light source that irradiates each ink layer with light having a wavelength of 540 to 590 nm, and an optical sensor that outputs a detection signal when the light from the light source passes through each ink layer; Since the bottom of the groove is separated from the ink layer discriminating means that discriminates one of each ink layer based on the detection signal of the optical sensor and starts the printing, the desired ink layer can be positioned at the printing start position without providing a bar code on the ink sheet. I can cue it. Therefore, the process of coloring and coating the barcode becomes unnecessary, and the width of the ink sheet can be reduced, so the ink sheet can be made smaller and the ink sheet can be manufactured at a lower cost.

Furthermore, the number of ink layers can be increased with the same length as before.

Near (2, phototransistor 11 and green (or yellow)
Since the light-emitting LEDIO is arranged on the same side and the reflection plate 22 is provided on the opposite side with the ink sheet 6 interposed therebetween, the height of the entire apparatus can be lowered and miniaturization can be achieved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a plan view of an ink ribbon according to the present invention, FIG. 3 is a diagram showing spectral sensitivity characteristics of a phototransistor, and FIG. 4 is a diagram showing ink layers of each color. FIG. 5 is a diagram showing the spectral characteristics of a red light emitting LED, FIG. 6 is a diagram showing another embodiment of the present invention, and FIG. 7 is a plan view showing a conventional ink sheet. It is. DESCRIPTION OF SYMBOLS 1...Platen 6...Ink sheet 8...Motor 10...Red light emitting LED 11...Phototransistor 14...Ink layer discrimination means

Claims (1)

[Claims] (1) An ink sheet in which ink layers of multiple colors are provided as a set in a predetermined color order, the ink sheet is heated by a thermal head, and color printing is performed on recording paper via the ink layers of each color. The thermal transfer color printer includes a light source that irradiates each ink layer with light with a wavelength of 540 to 590 nm, an optical sensor that outputs a detection signal when the light from the light source passes through each ink layer, and a light sensor that outputs a detection signal when the light from the light source passes through each ink layer. A thermal transfer type color printer characterized by comprising an ink layer discriminating means for discriminating one of the ink layers and locating the cue based on a detection signal.