JP3451533B2 - Color identification sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color identification sensor for identifying the color of an object based on the difference in the optical characteristics of the detected object, and more particularly to a technique for speeding up the same color determination process and improving the detection performance. .

[0002]

2. Description of the Related Art A color identification sensor has been known as a sensor for identifying the color of a detection object. The color identification sensor
In general, light of different wavelengths is time-divisionally projected to a detection object, and the reflected light from this detection object is received, and the reference color obtained from the reflected light of the reference color. From the value and the detected color value obtained from the reflected light of the detected object, an approximate value indicating the approximate value of the reference color and the color of the detected object is calculated, and the approximate value is preset. By comparing with the threshold value, it is identified whether the reference color and the color of the detection object are the same color.

[0003]

However, in the same-color determination method for the conventional color identification sensor as described above, complicated arithmetic processing is required to obtain the approximate value.
Since this calculation process takes a lot of time, there is a problem that it is difficult to increase the speed of the same color determination process. The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a color identification sensor that simplifies the same-color determination process and can speed up the determination process. Another object of the present invention is to provide a color identification sensor capable of improving detection performance without increasing processing time.

[0004]

To achieve the above object, the present invention provides a color identification sensor for identifying the color of a detection object, wherein at least two light beams having different wavelengths are projected.
One or more light sources, projecting means for projecting light of each wavelength component, light receiving means for receiving reflected light or transmitted light by a detection object of the projected light from the projecting means, and a reference color Reference color value setting means for setting a reference color value serving as a reference based on a light receiving signal from the light receiving means, detected color value acquiring means for acquiring a detected color value based on a light receiving signal based on the light receiving signal of the detection object, The difference between the reference color value and the detected color value of each wavelength component projected from the light means is obtained, and only the wavelength component having the maximum value is determined as the determination wavelength component for performing the same color determination, and the reference A determination wavelength component determination unit that determines the difference between the color value and the detected color value as a determination amount, and a determination unit that performs the same color determination by comparing the determination amount for the determination wavelength component with a set threshold value. It is a thing.

In this structure, the reference color value and the detected color value in each wavelength component projected from the light projecting means are
Of the difference , the wavelength component having the maximum value is determined as the determination wavelength component, the value is determined as the determination amount, and the determination amount for this determination wavelength component is compared with the set threshold value, Same color judgment is performed. In this way, among the projected wavelength components, the one having the maximum difference between the reference color value and the detected color value is determined as the determination wavelength component, and the same color determination is performed based on the determination amount of the determination wavelength component. The same color determination process is simplified, and the determination process can be speeded up.

According to the present invention, the light projecting means projects the wavelength component light determined as the determination wavelength component once onto the detection object, and the determination means is obtained by projecting the determination wavelength component. The same color determination process may be performed by comparing one detected color value with a set threshold value. In this configuration, the light projecting unit projects only the determination wavelength component used for the same color determination process and does not project the wavelength component not used for the same color determination, so that the same color determination process can be further speeded up.

According to the present invention, the light projecting means projects the wavelength component light determined as the determination wavelength component onto the detection object a plurality of times, and the determination means is obtained by projecting the determination wavelength component. The same color determination process may be performed by adding or integrating a plurality of detected color values and comparing the added value or the integrated value with a set threshold value. In this configuration, the determination means adds or integrates a plurality of detected color values for the determination wavelength component, and performs the same color determination using the added value or the integrated value. The difference in optical characteristics can be clarified, and the detection performance can be improved. Further, since the number of times the determination wavelength component is projected is increased and the number of times the other wavelength components are projected is reduced, the detection performance can be improved without increasing the processing time.

Further, according to the present invention, the margin is set with a certain width with respect to the threshold value, the detected color value is compared with the margin, and if the detected color value is less than or equal to the margin, It may further include warning information output means for outputting warning information. In this configuration, when the detected color value approaches the threshold value and becomes less than or equal to the margin, warning information indicating that the detection is being performed in an unstable manner is output, so that the user can stably obtain the same color. It is possible to know whether or not the judgment is made.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a color identification sensor according to an embodiment of the present invention.
This color identification sensor 1 has red (R), green (G), and blue (B).
The light of the three primary colors is projected in a time-division manner, and the detected object 2
It is a device for identifying the color of. In the figure, a light projecting unit (1) 3a and a light projecting unit (2) 3 using a light emitting diode or the like.
b and the light projecting unit (3) 3c (light source, light projecting means) have different wavelengths of light (R: λ = 680 nm, G: λ = 565 nm,
B: λ = 450 nm), and those lights are emitted to the detection object 2 in a time division manner. The light reflected by the detection object 2 is received by the light receiving unit 4 including a photodiode, converted into a light receiving signal, and sent to the control unit 5.

The control unit 5 sets and acquires a color value on the basis of a light reception signal from the light receiving unit 4 and a color value acquisition processing unit 6
(Reference color value setting means, detected color value acquisition means), memory 7 for storing color values, light projecting sections (1) 3a, (2) 3b,
(3) Each wavelength component (R,
In G and B), an approximation value (hereinafter referred to as a difference) between the reference color value and the detected color value is obtained, and the wavelength component having the maximum difference is determined as the determination wavelength component for performing the same color determination. A determination amount determination processing unit 8 (determination wavelength component determination means) that determines the difference between the reference color value and the detected color value as a determination amount,
In order to display on the display output unit 12 the measurement processing unit 9 (determination unit) that performs the color determination of the detected object 2 and outputs the determination result to the external output unit 10, the same chromaticity of the detected object color with respect to the reference color,
The display processing unit 11 (display output unit) that converts the determination amount into a display value is configured. The display output unit 12 includes a coincidence degree indicating lamp 15 (see FIG. 3), a threshold indicating lamp 16 (the same), and an output indicating lamp 17 (the same). Further, the control unit 5 includes an operation mode changeover switch for switching operation modes such as a registration mode and a measurement mode, a color value acquisition timing input switch, a threshold value change switch for changing a threshold value, and a light projecting method. An external input unit 13 including a light projecting method changeover switch for changing over is connected.

Next, details of the same color determination method by the control unit 5 and the same color degree display method by the display output unit 12 will be described with reference to FIGS. 2 and 3. When the operation mode of the sensor 1 is the registration mode, the reference color value is acquired by the color value acquisition processing unit 6 based on the light reception signal of the light reception unit 4 for the reference color, and the reference color value is stored in the memory unit 7. Is stored. The reference color value may be set by the sensor user operating the sensitivity volume or the like.
Further, when the operation mode is the measurement mode, the color value acquisition processing unit 6 acquires the detected color value based on the light receiving signal of the light receiving unit 4 for the detected object 2, and the detected color value is also stored in the memory unit 7. Is stored. Judgment amount determination processing unit 8
Determines the difference between the two color values stored in the memory unit 7, selects the wavelength component having the maximum difference among the projected wavelength components as the determination wavelength component for performing the same color determination, and determines the reference color The difference between the value and the detected color value is determined as the determination amount. In addition,
The determination amount is not limited to this, and a relative approximation degree obtained by a predetermined arithmetic expression, (reference value-K) / (reference value-detection value), or the like can be used.

For example, if the reference color value and the detected color value for the light of each wavelength component of R, G, B obtained in the color value acquisition processing unit 6 are as shown in FIG. 8 selects the wavelength component of G that maximizes the difference between the reference color value and the detected color value as the determination wavelength component, and determines the difference between the reference color value and the detected color value of the G wavelength component as the determination amount. To do. The measurement processing unit 9 compares a preset threshold value for determining the same color range for the reference color with the determination amount for the determination wavelength component, and determines whether the detection object 2 is within the same color range for the reference color. It is determined whether the result is the external output unit 1
It is output to an external device via 0. As described above, the wavelength component having the maximum difference between the reference color value and the detected color value among the wavelength components emitted from the light projecting units (1) 3a, (2) 3b, and (3) 3c is determined as the determination wavelength component. Since the same color determination is performed based on the determination amount for this determination wavelength component, the determination process is performed in comparison with the same color determination using the approximate value property value obtained by the conventional complicated calculation. It is simple, and the determination process can be speeded up.

The display processing unit 11 converts the determination amount into a display value and outputs this display value to the display output unit 12. As shown in FIG. 3, the display output unit 12 includes a matching degree display lamp 15 that displays the matching degree between the reference color value and the detected color value, a threshold value display lamp 16 that displays the threshold level, and a measurement processing unit. 9 and the output indicator lamp 17 that is turned on when it is determined that they have the same color. For example, as shown in FIG. 3A, the reference color value and the detected color value have different values. In this case, in the display output unit 12, the matching degree indicating lamp 15 of the portion 20 corresponding to the detected color value is turned on, the matching degree indicating lamps of the portions 21 corresponding to other determination amounts are not turned on, and Since the detected color value is outside the same color range shown by the threshold value indicating lamp 16, the output indicating lamp 17 is not turned on. Also,
As shown in FIG. 3B, when the reference color value and the detected color value match, all the matching degree indicating lamps 15 are turned on and the detected color value is indicated on the threshold value indicating lamp 16. Since it is within the same color range, the output indicator lamp 17 is turned on. In this way, since the determination amount is displayed on the coincidence degree indicator lamp 15 with the reference color value as a reference, the user can recognize the same chromaticity of the detected object with respect to the reference color. Further, since the threshold level is displayed on the threshold indicator lamp 16, the user can confirm the determination state. Further, the threshold level is configured to be changed by operating a threshold change switch provided on the external input unit 13, whereby the user can see the same color determination state. Can be changed to a desired state.

The control unit 5 can be replaced by a microcomputer. The operation of the microcomputer in this case will be described with reference to the flowchart of FIG. First, when the mode changeover switch (not shown) of the external input unit 13 is operated to enter the measurement mode (S
1), initial setting is performed (S2), and a threshold value is further set (S3). The mode switch is operated,
When the mode is changed (YES in S4) and the registration mode is set (YES in S16), the process proceeds to S17, the reference color value is acquired, and this value is stored. When the registration mode ends (NO in S16), the process returns to S3 to set the threshold value. If the mode is not changed (NO in S4), the light projecting units (1) 3a, (2) 3b, (3) 3c are sequentially driven to project light (S5, S7, S9), R, G, The detected color value for each projected wavelength component of B is acquired, and this value is stored (S
6, S8, S10). Next, the difference between the reference color value and the detected color value in the projected wavelength component is obtained, and the maximum amount thereof is set as the determination amount (S11). The operation for obtaining the maximum value of the difference between the reference color value and the detected color value is performed for all the projected wavelength components, and if this operation is completed for all the projected wavelength components (S12).
YES), the wavelength component having the largest difference between the reference color value and the detected color value is determined as the determination wavelength component for performing the same color determination, and the difference between them is determined as the determination amount (S1).
1). Next, the same color determination process is performed by comparing the determination amount for the determination wavelength component with the threshold value set in S3 (S13). Next, a margin determination process for checking whether or not the same color determination process is being performed stably is performed (S14), and the same color determination result and the margin determination result are displayed by the display output unit 12 ( S1
5) Further, output processing is performed by the external output unit 10 (S
16). The details of the margin determination processing performed in S14 will be described later.

Next, a light projecting method using the light projecting units (1) 3a, (2) 3b, (3) 3c for improving the detection performance,
The color value acquisition method by the color value acquisition processing unit 6 and the same color determination processing method by the measurement processing unit 9 will be described with reference to FIG. By counting the number of times used as the judgment amount for each wavelength component, the wavelength component used most for color judgment can be known, and the number of times the wavelength component often used for this judgment is projected can be used for judgment. The detection performance can be improved by reducing the number of times of projecting the wavelength components that cannot be detected. For example, as shown in FIG. 2 above, R, B
If there is no difference in the color value with the light of G, and there is a difference in the color value with the light of G, the light projecting unit is switched according to the operation of the light projecting method changeover switch (not shown) of the external input unit 13 by the user. (1) 3a,
(2) 3b and (3) 3c are shown in FIG. 5 (b) from the projection method for evenly projecting R, G, B lights onto the detection object 2 as shown in FIG. 5 (a). The projection method is switched to the projection method in which the projection (2) by the wavelength component (G) determined as the determination wavelength component is projected a plurality of times as shown. Further, the color value acquisition unit 6 adds or integrates a plurality of G detected color values obtained by this light projecting method, and the measurement processing unit 9 sets the added value or the integrated value to a preset threshold. The same color determination processing is performed by comparing with the value. As a result, the difference in optical characteristics between the reference color and the detection object 2 can be clarified, and the detection performance can be improved. Moreover, since the number of times the determination wavelength component is projected is increased and the number of times the other wavelength components are projected is reduced, the detection performance can be improved without increasing the processing time. In addition, the judgment amount is added or integrated,
The same color determination may be performed based on the added value or the integrated value.

Further, as shown in FIG. 5C, only the light projection (2) by the G light having the largest color value difference is projected once onto the detection object 2, and the measurement processing section 9 By performing the same-color determination processing by comparing one detected color value obtained by projecting the G light with a preset threshold value, the same-color determination processing becomes even simpler. Further, it is possible to further speed up the determination of the same color. It should be noted that the switching of the light projecting methods shown in FIGS. 5B and 5C can be switched by the user operating the light projecting method changeover switch provided on the external input unit 13. Is configured.

Next, the margin determination processing will be described with reference to FIGS. 6 and 7. The allowance determination process is to compare the set allowance with the determination amount, and output the warning information to the outside when the determination amount becomes smaller than this allowance, as shown in FIG. As shown in c), this is a function for checking the stability of the same-color determination state when the light projecting method is switched in order to improve the detection performance and increase the speed. For example, the R, G, and
When the reference color value and the detected color value for the light of each wavelength component of B are as shown in FIG. 6A, the difference between the reference color value and the detected color value for the wavelength component of G is determined as the determination amount. Is
Further, the margin is set with a certain width with respect to the threshold value of G.

When the surface color of the detection object 2 is such that the reference color and the detection color (colors outside the same color range) are alternately and continuously provided as shown in FIG. Based on the same color judgment by the measurement processing unit 6, as shown in FIG.
The control output from the measurement processing unit 6 is repeatedly turned on and off alternately. Here, if the determination amount is larger than the margin, it is determined that the same-color determination is performed with a margin, so that the sensor 1 does not output a warning output as shown in FIG. 7C. . On the other hand, when the determination amount is smaller than the margin, it is determined that the same-color determination is performed with a value extremely close to the threshold value, and it is determined that the determination is not performed with a margin. As described above, when the control output is OFF, the sensor 1 outputs warning information. This allows the user to
It is possible to know that the same color determination is performed in an unstable state, and it is possible to take measures such as switching the light projecting method.

The present invention is not limited to the above embodiment, and various modifications can be made. For example, in the same-color determination method described above, detection is performed by the reflected light from the detection object 2, but the detection object 2 is formed of a transparent material such as transparent glass, a transparent PET bottle or a transparent bottle. Alternatively, the detection may be performed using these transmitted lights. In the above embodiment, the color value is acquired based on the light reception signal from the light receiving unit 4 and the same color determination is performed based on the color value. However, R / (R + G +
B), G / (R + G + B), B / (R + G + B), and other evaluation values (the ratio of the received light signal value for each wavelength component to the total signal value) are calculated, and the same color determination is performed using this evaluation value. May be As a result, even if the distance fluctuates or the power supply voltage fluctuates, the fluctuation is canceled, so that the same color determination can be stably performed.

[0020]

As described above, according to the present invention, the difference between the reference color value and the detected color value is obtained from the projected wavelength component, and the wavelength component having the maximum value is determined for the same color determination. Along with determining as the wavelength component, the closeness value between the reference color value and the detected color value is determined as the determination amount, and the same color determination process is performed based on the determination amount for the determination wavelength component. The determination process can be simplified and the determination process can be speeded up.

Further, according to the present invention, the wavelength component light determined as the determination wavelength is projected onto the detection object once, and the determination means obtains one detected color value obtained by projecting the determination wavelength component. Since the same-color determination processing is performed based on the above, the wavelength component that is not used for the same-color determination is not projected, and the same-color determination processing can be further speeded up.

Further, according to the present invention, a plurality of detected color values for the determination wavelength component are added or integrated, and the same color determination is performed using the added value or the integrated value. And the optical characteristic difference between the detected color value can be clarified, and the detection performance can be improved.
Moreover, since the number of times the determination wavelength component is projected is increased and the number of times the other wavelength components are projected is reduced, the detection performance can be improved without increasing the processing time.

Further, according to the present invention, when the detected color value approaches the threshold value and becomes less than or equal to the margin, warning information indicating that the detection is unstable is output. Therefore, the user can know whether or not the same color determination is being performed stably, and when receiving the warning information that the same color determination is being performed in an unstable manner, the light emitting method is switched. Such actions can be taken.

[Brief description of drawings]

FIG. 1 is a block diagram showing a processing system of a color identification sensor according to an embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining a detected color value and a determination amount with respect to a reference color value.

3A and 3B are diagrams for explaining a method of displaying the same chromaticity by a display output unit.

FIG. 4 is a flowchart showing a process of the same color determination operation of the color identification sensor.

5A, 5B, and 5C are diagrams for explaining a light projecting method and a color value acquiring method for improving detection performance and processing speed.

6 (a) and 6 (b) are schematic diagrams for explaining the relationship among the reference amount, the determination amount, the margin, and the threshold value.

FIG. 7 is a time chart for explaining a margin determination operation by a color identification sensor.

[Explanation of symbols]

1 Color Identification Sensor 2 Detecting Objects 3a, 3b, 3c Light Emitting Section (Light Source, Light Emitting Means) 4 Light Receiving Section (Light Receiving Means) 6 Color Value Acquisition Processing Section (Reference Color Value Acquisition Means, Detected Color Value Acquisition Means) 8 Judgment Quantity determination processing section (determination wavelength component determination means) 9 Measurement processing section (determination means) 12 Display output section (display output means)

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Claims (4)

(57) [Claims] 1. A color identification sensor for identifying the color of a detection object, comprising: at least two or more light sources for projecting lights having different wavelengths, and projecting means for projecting light of each wavelength component, Light receiving means for receiving reflected light or transmitted light from an object detected by the light emitting means, and a reference color value for setting a reference color value as a reference based on a light receiving signal by the light receiving means for a reference color. Setting means; detection color value acquisition means for acquiring a detection color value based on a light reception signal by the light reception signal for a detection object; and the reference color value and the reference color value in each wavelength component projected from the light projection means. The difference between the detected color value is determined, and only the wavelength component having the maximum value is determined as the determination wavelength component for performing the same color determination, and the difference between the reference color value and the detected color value is determined as the determination amount. Format Color identification sensor, wherein a wavelength component determining means, further comprising a determining means for performing a same color determined by comparing the determined determination amount was set threshold for wavelength components. 2. The light projecting unit projects the wavelength component light determined as the determination wavelength component once on a detection object, and the determination unit is obtained by projecting the determination wavelength component. The color identification sensor according to claim 1, wherein the same color determination process is performed by comparing one detected color value with a set threshold value. 3. The light projecting means projects the wavelength component light determined as the determination wavelength component onto a detection object a plurality of times, and the determination means is obtained by projecting the determination wavelength component. 2. The same color determination process is performed by adding or integrating a plurality of detected color values and comparing the added value or the integrated value with a set threshold value. Color identification sensor. 4. A margin is set with a certain width with respect to the threshold value, the detected color value is compared with the margin, and a warning is issued when the detected color value is equal to or less than the margin. The color identification sensor according to any one of claims 1 to 3, further comprising warning information output means for outputting information.