JPH11180016A - Color detecting sensor for ink ribbon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a color of an ink ribbon of a low cost without providing a mark for detecting the color of the ribbon. SOLUTION: An LED 11 of a wavelength for maximizing a light absorption of a first color of a four-color ink ribbon 10 is used, and an LED 12 of a wavelength for maximizing a light absorption of a third color is used. And, the LEDs 11, 12 are respectively driven in different lighting sequences. Thus, the four colors of the ribbon 10 can be detected without providing a mark for detecting the color of the ribbon. And, since it is not necessary to provide the mark on the ribbon, an area of the ribbon can be reduced that much. As a result, its cost can be reduced, and resources can be saved. And, two light sources are driven different lighting sequences, and hence only one light receiving sensor is sufficient, and its cost can be reduced that much.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermal transfer printer,
The present invention relates to a color detection sensor for an ink ribbon suitable for use in a printing apparatus such as a laser thermal transfer printer that uses an application ribbon that uses a step-by-step process.

[0002]

2. Description of the Related Art Conventionally, for detecting the color of an ink ring,
As shown in FIG. 7, a black mark 2 is provided at the boundary of each color of the ink ribbon 1, and this mark 2 is detected by two light receiving sensors 3, 4 such as photodiodes, and the color is determined based on each detection signal. judge. In this case, a light source (not shown) such as one LED (light emitting diode) is disposed at a position facing the light receiving sensors 3 and 4 with the ink ribbon 1 interposed therebetween.
Further, as shown in this figure, of the marks 2, the mark 2 between the yellow ink-coated surface and the black ink-coated surface.
Are arranged closer to the center than the other marks 2 by one light receiving sensor.

When the mark 2 blocks the light from the light source, the output signals of the light receiving sensors 3 and 4 change. The time chart shown below the ink ribbon 1 in this figure shows the output change of each of the light receiving sensors 3 and 4, and the ink ribbon 1
Is transported in the direction of arrow A from the position shown in FIG.
The output of the light receiving sensor 4 is the mark 2 arranged near the center.
Becomes "L" level from the point of time of arrival, and continues until the state passes through the black ink application surface. It is at the “H” level immediately after the black ink-coated surface has passed until the next mark 2 near the center comes. On the other hand, the output of the light receiving sensor 3 becomes “L” level when the black ink-coated surface comes, and becomes “H” level after the first mark 2 passes. Then, each of the two marks 2 following the first mark 2 becomes the “L” level.

FIG. 8 is a truth table in the above case. As can be seen from the table, when the output of the light receiving sensor 3 is "H" and the output of the light receiving sensor 4 is "L", the head of the ribbon on the black (K) ink applied surface can be detected. Also, the light receiving sensor 3
Is "L" and the output of the light receiving sensor 4 is "H", the black ink-coated surface can be detected. When the output of the light receiving sensor 3 is “L” and the output of the light receiving sensor 4 is “H”, cyan (C), magenta (M), and yellow (Y)
Can be detected in the transport direction of each ink-coated surface. When the output of the light receiving sensor 3 is “H” and the output of the light receiving sensor 4 is “H”, each of the cyan (C), magenta (M), and yellow (Y) ink applied surfaces can be detected.

In the prior art, it is necessary to discriminate between the head of the first color (in this example, black (K)) ink application surface and the head of the other color ink application surface. However, it is unnecessary to distinguish the other colors, that is, cyan (C), magenta (M), and yellow (Y), since it is sufficient to count the number of colors from black (K).

[0006]

By the way, the above-described conventional detection of the color of the ink ring has the following problems. That is, although the mark 2 is added to detect the color of the ink ribbon 1, the area of the ribbon is increased by the addition of the mark 2, which leads to an increase in cost and waste of resources. Mark 2
There is a risk of failure due to failure of the device. In addition, mark 2
If it is attempted to detect a color without adding a mark, a light receiving sensor of three wavelengths is required, which increases the cost.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink ribbon color detection sensor which can detect the color of an ink ribbon at low cost without providing a mark for detecting the color of the ink ribbon. I do.

[0008]

According to the present invention, there is provided a color detection sensor for an ink ribbon, which is arranged on an ink ribbon having four ink application surfaces continuously provided in a longitudinal direction.
A first light source and a second light source that output light having a wavelength at which light absorption at the two-color ink-coated surfaces on both sides separated by one color of the arranged four-color ink-coated surfaces is maximized; The first light source and the second light source are disposed at positions opposed to the first light source and the second light source with the ink ribbon interposed therebetween, or the first light source and the second light source can be detected. The first light source and the second light source are disposed on the same side as the second light source, and are reflected by a reflector disposed at a position facing the first light source and the second light source with the ink ribbon interposed therebetween. A light receiving sensor capable of detecting each light of the light source; and control means for driving the first light source and the second light source in different lighting sequences and outputting a detection signal of the light receiving sensor. .

According to this configuration, the light source has a wavelength at which light absorption is greatest for the first color ink-coated surface of the four-color ink ribbon, and the light absorption is greatest for the third color ink-coated surface. By using a light source having a wavelength, it is possible to identify colors without providing a mark for indicating a boundary between ink-coated surfaces. As a result, the adjacent ink application surfaces can be provided continuously, so that the area of the ribbon can be reduced. As a result, costs can be reduced and resources can be saved.

[0010] The two sides of the ink ribbon separated from each other by one color.
If one of the colors is black and the other is cyan, one light source may output infrared light and the other light source may output red light. If one of the two colors on both sides of the ink ribbon separated by one color is black and the other is magenta, one light source outputs infrared light and the other light source outputs green light. good.

Further, if the timing for turning on the two light sources is shifted, only one light receiving sensor is required, and the cost can be reduced. As a way to shift the timing,
There is a method of alternately lighting, or a method of setting one to a lighting state and blinking the other.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an embodiment of a color detection sensor for an ink ribbon according to the present invention. FIG. 2 is a diagram for explaining color detection by the color detection sensor shown in FIG. FIG. 4 is a diagram showing a truth table for color detection.

The ink ribbon color detection sensor of this embodiment has LEDs (light sources) 11 having different emission wavelengths from each other.
12, a phototransistor (light receiving sensor) 13 having frequency characteristics capable of detecting light of both the LEDs 11 and 12, and driving the LEDs 11 and 12 in different lighting sequences, respectively.
And a controller 14 for outputting the detection signal of

The LEDs 11 and 12 output light having a wavelength at which the light absorption of the first and third colors of the four-color ink ribbon 10 is maximized. In this embodiment, the first color is black (K) and the third color is magenta (M). L
The ED 11 outputs the most attenuated light in black, and the LED 12 outputs the most attenuated light in green. In this case, since the black absorbs all the light, the light from the LED 12 is attenuated even in the black. Therefore, both light of the LEDs 11 and 12 is attenuated with respect to the black (K) ink applied surface of the ink ribbon 10,
Only the light of the LED 12 is attenuated with respect to the magenta (M) ribbon. As is well known, magenta is an intermediate color between red and blue, so that green light is absorbed and hardly transmitted.

The phototransistor 13 has a frequency characteristic of receiving light of the LEDs 11 and 12 having different emission wavelengths. Since the controller 14 captures the output signals of the two LEDs 11 and 12 with one phototransistor 13, the two colors are separated by changing the lighting sequence of each of the LEDs 11 and 12. As this lighting sequence, for example, the LEDs 11 and 12 are alternately turned on. One is always lit and the other is blinking. When the lighting is performed alternately, sampling is performed in synchronization with the emission signal.

FIG. 4 shows a sequence in which the LEDs 11 and 12 are alternately turned on. The LEDs 11 and 12 are turned on alternately, and the phase is set to 90 from the start of each lighting.
The output signals of the LEDs 11 and 12 are sampled at positions delayed by degrees. The frequency at which each of the LEDs 11 and 12 blinks may be determined in accordance with the transport speed of the ink ribbon 10, but is preferably about 10 Hz to 10 kHz.

On the other hand, FIG. 5 shows a sequence in which one of the LEDs 11 and 12 is constantly turned on and the other is blinked. In this case, as shown in (a), the LED 11 is turned on and off, and the LED 12 is constantly turned on. In this sequence, the color can be identified by reading both the amplitude and the output level of the phototransistor 13. in this case,
(B), when both the amplitude and the level are large, (c), when the amplitude is small and the level is large, (d) when the amplitude is large and the level is small, (e) when the amplitude and the level are small Are both small.

As described above, one of the ink ribbons 10 of four colors is used.
By using the LED 11 of the wavelength at which the light absorption of the color is the largest, and using the LED 12 of the wavelength at which the light absorption of the third color is the largest, and driving each of these LEDs 11 and 12 in a different lighting sequence, When the ink ribbon 10 is transported in the direction of arrow A from the position shown in FIG. 2 and the top of the black (K) ink application surface is applied on the phototransistor 13, the light from the LED 11 and the LED 12 are both absorbed. Phototransistor 13
Are output from “H” to “L” for LED11 (a) and LED12 (b).

This state continues until the black (K) ink-coated surface passes, and when the top of the black (K) -cyan (C) ink-coated surface is applied, both the light of the LED 11 and the LED 12 are transmitted. The output of the phototransistor 13 changes from “L” to “H” for the LEDs 11 and 12. This state continues until the cyan (C) ink-coated surface passes, and when the cyan (C) ink-coated surface passes and the top of the magenta (M) ink-coated surface is applied, the light of the LED 11 is not absorbed. The output of the phototransistor 13 for the LED 11 keeps the state of “H”. This state is the same even when the yellow (Y) ink application surface comes, and changes from “H” to “L” when the next black (K) comes.

On the other hand, when the front surface of the magenta (M) ink application surface passes through the cyan (C) ink application surface, the light of the LED 12 is absorbed.
The output of the phototransistor 13 with respect to 12 changes from “H” to “L”. This state continues until the ink application surface of magenta (M) passes. Thereafter, when the head of the yellow (Y) ink application surface is applied, the light of the LED 12 is not absorbed, and the output of the phototransistor 13 for this LED 12 changes from “L” to “H”. Thereafter, the above operation is repeated.

Here, the phototransistor 1 shown in FIG.
In the method of reading both the amplitude and the output level of No. 3, both the amplitude and the level become small on the black (K) ink applied surface as shown in FIG. Then, when the cyan (C) ink applied surface comes from the black (K) ink applied surface,
As shown in (b), both the amplitude and the level become large. Further, when the magenta (M) ink applied surface comes from the cyan (C) ink applied surface, the amplitude becomes large and the level becomes small as shown in (d). When the yellow (Y) ink applied surface comes from the magenta (M) ink applied surface,
As shown in (b), both the amplitude and the level become large.

As described above, in this embodiment, the LED 11 having a wavelength near the light absorption of the first color of the ink ribbon 10 of the four colors is used, and the LED 11 near the light absorption of the third color is the largest. Since the LEDs 11 and 12 are driven in different lighting sequences using the LED 12 of the wavelength, the four colors of the ink ribbon 10 can be detected without providing a mark for detecting the color of the ink ribbon. be able to. Since there is no need to provide a mark on the ink ribbon, the area of the ribbon can be reduced accordingly, and as a result, costs can be reduced and resources can be saved. Further, by driving each of the two light sources in a different lighting sequence, only one phototransistor 13 is required, and the cost can be reduced accordingly. In addition, since no mark is required, there is naturally no risk of failure due to mark failure. Further, since the phototransistor 13 may have a frequency characteristic capable of receiving light of two wavelengths, the cost can be reduced as compared with the case where a phototransistor of three wavelengths must be used.

In the above embodiment, the LEDs (light sources) 11 and 12 and the phototransistor (light receiving sensor) 1
3 are arranged at positions facing each other with the ink ribbon 10 interposed therebetween, but as shown in FIG.
D (light sources) 11 and 12 and a phototransistor (light receiving sensor) 13 are arranged on the same side, and are arranged at positions facing LEDs (light sources) 11 and 12 and a phototransistor (light receiving sensor) 13 with the ink ribbon 10 interposed therebetween. Each light of the LEDs (light sources) 11 and 12 reflected by the reflected reflector 15 may be detected by a phototransistor (light receiving sensor) 13. In FIGS. 1 and 6, one light receiving sensor is provided for two light sources, but one light receiving sensor may be provided for one light source.

In the above embodiment, the four colors of the ink ribbon 10 are identified by the first color and the third color of the ink ribbon 10, but may be identified by the second color and the fourth color. good. In addition, the ink ribbon is not limited to those of four colors, and it goes without saying that the present invention can be applied to any ink ribbon of four colors or more. In this case, it is necessary to appropriately prepare the number of phototransistors as light receiving sensors and the number of LEDs as light sources as necessary.

In the above embodiment, black, cyan,
Although the ink ribbon 10 composed of four colors of magenta and yellow is used, the ink ribbon 10 composed of four colors of black, magenta, cyan, and yellow may be used. In this case, LE
D11 that outputs infrared light is used.
It is preferable to use a device that outputs red light as 2. Even in this manner, the color of the ink ribbon can be identified. In particular, since an LED that outputs light with a long wavelength is inexpensive, the cost of the color detection sensor itself can be reduced. In the above embodiment, the LED is used as the light source.
A light source that emits light at a required wavelength, such as a (laser diode), EL (electroluminescence), plasma, CRT (cathode ray tube), and incandescent lamp with a filter, can be used as appropriate. In addition, a phototransistor was used as a light receiving sensor.
A sensor corresponding to a required wavelength can be used as appropriate.

[0026]

As described above, according to the present invention,
The four colors of the ink ribbon can be detected without providing a mark for detecting the color of the ink ribbon. Further, since there is no need to provide a mark, the area of the ribbon can be reduced accordingly, so that cost can be reduced and resources can be saved.

Further, since each of the two light sources is driven in a different lighting sequence, only one light receiving sensor is required, and the cost can be reduced accordingly.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a color detection sensor for an ink ribbon according to the present invention.

FIG. 2 is a diagram for explaining an operation of the ink ribbon color detection sensor of the embodiment.

FIG. 3 is a diagram for explaining an operation of the ink ribbon color detection sensor of the embodiment.

FIG. 4 is a diagram for explaining the operation of the ink ribbon color detection sensor of the embodiment.

FIG. 5 is a diagram for explaining an operation of the ink ribbon color detection sensor of the embodiment.

FIG. 6 is a block diagram showing a configuration of another embodiment of the ink ribbon color detection sensor according to the present invention.

FIG. 7 is a diagram for explaining a conventional ink ribbon color detection method.

FIG. 8 is a diagram for explaining a conventional ink ribbon color detection method.

[Explanation of symbols]

 Reference Signs List 10 Ink ribbon 11, 12 LED (light source) 13 Phototransistor (light receiving sensor) 14 Controller (control means) 15 Reflector

Claims (6)

[Claims] 1. An ink ribbon having four ink-coated surfaces continuously arranged in the longitudinal direction, and two colors on both sides of one of the four-color ink-coated surfaces which are arranged on the ink ribbon. A first light source and a second light source that output light having a wavelength at which light absorption at the ink-coated surface is the largest, and a position facing the first light source and the second light source with the ink ribbon interposed therebetween. The first light source and the second light source can be detected, or the first light source and the second light source are disposed on the same side as the first light source and the second light source, and the first light source and the second light source are interposed between the first light source and the second light source. A light receiving sensor capable of detecting respective light of the first light source and the second light source reflected by a reflector disposed at a position facing the light source and the second light source; Are driven in different lighting sequences, and Color detection sensor of the ink ribbon, characterized in that a control means for outputting a detection signal of the sensor. 2. The ink ribbon according to claim 1, wherein said ink ribbon comprises two ink ribbons on both sides thereof separated by one color.
The ink ribbon according to claim 1, wherein if one of the colors is black and the other is cyan, the first light source outputs infrared light, and the second light source outputs red light. Color detection sensor. 3. The ink ribbon according to claim 1, wherein said ink ribbon is provided on both sides of said ink ribbon.
If one of the colors is black and the other is magenta, the first
2. The color detection sensor according to claim 1, wherein the light source outputs infrared light, and the second light source outputs green light. 4. The color detection of an ink ribbon according to claim 1, wherein the controller turns on the first light source and the second light source at different timings. Sensor. 5. The ink ribbon color detection sensor according to claim 1, wherein the controller turns on the first light source and the second light source alternately. 6. The controller according to claim 1, wherein the controller turns on one of the first light source and the second light source and blinks the other light source. Ink ribbon color detection sensor.