JPH06160189A - Color judging method for covered wire - Google Patents

Abstract

PURPOSE:To objectively and accurately judge the color of a fine-diameter covered wire. CONSTITUTION:The light having the spectrum distribution equal or approximate to the natural light is radiated to a covered wire 2 from a light source 6 at the constant illuminance on the surface, and a fixed region including the covered wire 2 radiated with the light is photographed by an image pickup means 8 to obtain R, G, B color signals. Histograms of their luminosity distributions are generated respectively on the R, G, B color signals by a histogram generating means 14. The maximum luminosities HR, HG, HB of the histograms of the R, G, B color signals are detected by a maximum luminosity detecting means 16, and the color of the covered wire 2 is judged by a color judging means 18 based on the combination of the maximum luminosities of R, G, B colors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color judging method for judging the color of a coating wire having a coating formed on its surface for insulation or protection.

[0002]

2. Description of the Related Art Generally, a core wire which constitutes an electric wire or an optical fiber cable has a coating formed on its surface for insulation or protection, and these coatings identify each core wire. There are various colors to make it easier.

That is, when connecting cables to each other, connecting cables to various devices, etc., it is essential to identify each core wire in order to prevent erroneous wiring. Therefore, the surface of the core wire must be identified. A colorant such as a pigment is mixed in the formed film for coloring.

By the way, when the colorant is mixed in the coating film in this way, the color is subtly changed depending on the mixing amount and the mixing ratio. Therefore, when manufacturing the cored wire with such a color, it is necessary to perform quality control so as to obtain a desired color.

Conventionally, in order to judge the color of the coating of the core wire, a standard color sample is referred to, and this color sample is compared with the color of the manufactured coating of the core wire to judge the quality. There is.

[0006]

As described above, the prior art is as follows.
Since the quality of the color was visually determined while comparing the color of the standard core with the color of the manufactured core wire, the objectivity was poor, and therefore individual differences occurred. Even when judged by the same person, the color may seem to have changed apparently depending on the surrounding brightness and the size of the outer diameter of the core wire to be handled, and these factors may cause variations in quality. There was a problem such as occurrence.

On the other hand, although the prior art provides a device for judging the color of a plate-shaped object having a considerably wide color area (around several cm), this method is extremely thin like a core wire. It is difficult to accurately judge the color added to the area (for example, the diameter is about 0.45 to 0.9 mm).

The present invention has been made in order to solve such a conventional problem, and it is possible to objectively and accurately determine the color attached to a thin coated wire such as a cable core wire. The task is to do.

[0009]

The present invention adopts the following constitution in order to solve the above problems.

That is, in the coated wire color determination method according to the present invention, the coated wire is irradiated with light having a spectral distribution identical to or close to natural light so that the illuminance on the surface is constant, An image of a certain area including the covered wire irradiated with the light is imaged, R, G, and B color signals are extracted, and based on these R, G, and B color signals, these R, G, and B color signals are extracted. After creating the histograms of the respective lightness distributions, the maximum brightness of each histogram is detected, and the color of the covered wire is determined based on the combination of the respective maximum brightnesses of R, G, and B.

[0011]

In the above arrangement, the R, G, B histograms are created based on the reflected light from the covered wire to determine the maximum brightness, and the color is determined from the combination of these maximum brightnesses. The color will be determined based on the converted data. Therefore, the color applied to the covered wire can be objectively and accurately determined.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of an apparatus used for a color judgment method of a covered wire according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes the entire color determination device, 2 is a coated wire having a colored coating formed on its surface, 4 is a sample stand, and 6 is a coated wire, and the illuminance on the surface is constant. Is a lamp as a light source that emits light having a spectral distribution identical to or close to that of natural light.

Numeral 8 captures an image of a certain area irradiated with the light from the lamp 6, and R, R based on the reflected light in the imaged area.
A video camera 10 as an image pickup means for extracting the G, B color signals, 10 is a data processing means for judging the color of the coating of the covered wire 2 based on the R, G, B color signals from the video camera. Input means for setting and inputting data to the data processing means 10, which is composed of, for example, a keyboard or a mouse. An output unit 12 outputs the result of the data processing unit 10, and is composed of, for example, a display or a printer.

The data processing means 10 described above uses the R, G, and B color signals obtained by the video camera 8 in accordance with the R, G, and B color signals.
Histogram creating means 14 for creating a histogram of lightness distributions of G and B, and this histogram creating means 1
The color of the covered wire 2 is determined based on the combination of the maximum brightness detecting means 16 for detecting the maximum brightness of each histogram created in 4 and the maximum brightness of each of R, G and B detected by the maximum brightness detecting means 16. The color determining means 18 for determining is provided.

Next, a method for determining the color of the covered wire using the device 1 having the above-mentioned configuration will be described.

First, prior to determining the color of the coating of the coated wire 2, data on a standard color sample is collected in advance, and a threshold for color determination is set based on the data.

First, the samples of each color are individually placed on the sample table 4, and light is emitted from the lamp 6 so that the illuminance of each color sample and its surroundings becomes constant. Then, the video camera 8 captures the reflected light in a certain area including the color sample irradiated with this light.

In response to this image pickup, R, G, and B color signals are obtained as the output of the video camera 8.
Each color signal of G and B is taken into the data processing means 10.

The histogram creating means 14 of the data processing means 10 creates a histogram of the lightness distribution for each of the R, G and B color signals. The histogram created in this way is as shown in FIGS. 2 to 4, for example.

That is, assuming that the standard color sample is "black", the respective histograms for the R, G, B color signals are as shown in FIG. If the standard color sample is "white", the histograms for the R, G, B color signals are as shown in FIG. Furthermore, if the standard color sample is "brown",
The respective histograms relating to the R, G, B color signals are as shown in FIG.

Since the histogram data for these color samples are sent to the maximum brightness detecting means 16 in the next stage, the maximum brightness detecting means 16 detects the maximum brightness of the histogram for the R, G, B color signals. To do.

For example, when the standard color sample is "black", the maximum brightness in each histogram relating to the R, G, B color signals (hereinafter, this will be represented by HR, HG, HB).
Is 50 for HR, 80 for HG, and 80 for HB (Fig. 2
R) when the standard color sample is “white”,
The maximum brightness in each histogram for the G and B color signals is 220 for HR, 250 for HG, and 255 for HB (see FIG. 3). Furthermore, when the standard color sample is “brown”, R, G, B The maximum brightness in each histogram for the color signal of HR is 152 for HR, 52 for HG, and 135 for HB.
(See FIG. 4).

The maximum brightness HR, HG, of each color signal of R, G, B relating to each standard color sample detected in this way
The HB is, for example, as shown in FIG. As can be seen from FIG. 5, the range of HB ≦ 90 is only when the color sample is “black”, and the range of 90 <HB ≦ 120 is only “red”. Also, 120 <HB ≦ 15
Only "green" is in the range of 0 and HR≤120. Therefore, each color can be determined by predetermining such conditions. Therefore, threshold values for color determination are set based on respective values of HR, HG, and HB for standard color samples as shown in FIG. 5, and these threshold values are input from the input means 11. Then, the color determination means 18 is registered in advance. H obtained by measurement
Considering that each value of R, HG, and HB has some variation, each threshold value for color determination is ± 10.
Leave a margin of about ± 20. In this example, the threshold values of HR, HG, and HB for color determination are set to the conditions shown in FIG.

After the above-mentioned pretreatment is completed, the process proceeds to the color judgment of the covered wire 2.

For this, as in the case described above, the sample table 4
Natural light is emitted by the lamp 6 so that the illuminance on and around the surface of the covered wire 2 placed on is constant. Then, the reflected light in a certain area including the covered wire 2 irradiated with natural light is captured by the video camera 8.

In response to this image pickup, R, G, and B color signals are obtained as the output of the video camera 8. Therefore, these color signals are taken into the data processing means 10.

The histogram creating means 14 of the data processing means 10 creates a histogram of the lightness distribution for each of these R, G and B color signals. The histogram created in this way is as shown in FIG. 7, for example.

Next, the maximum brightness detecting means 16 determines the maximum brightness in each histogram for each of the R, G, B color signals. In the example of FIG. 7, HR = 190, H
G = 200 and HB = 200.

Then, these maximum brightness HR, HG, H
Since each data of B is sent to the color determination means 18 in the next stage, the color determination means 18 receives the maximum brightness HR, HG,
Based on the HB value, the color of the covered wire 2 is determined according to the flowchart shown in FIG. For example, in the case of the histogram shown in FIG. 7, according to the flowchart of FIG. 6, there is no one corresponding to each color sample, so it is determined that the color is defective. Also, for example, if HB = 79, "black" means HR
= 180 and HB = 140, it is determined to be "yellow".
Then, these determination results are output to the output means 12.

In this way, it can be accurately determined whether the color of the coating of the coated wire 2 is proper with respect to the standard color sample.

[0032]

According to the present invention, since the color is always determined based on the digitized data, there is no individual difference as compared with the conventional visual determination.
Further, it is not affected by the brightness of the surroundings and the size of the outer diameter of the covered wire to be handled. Therefore, even if the diameter is small, such as a core wire forming a cable, which has a coating for insulation or protection, the color of the coating can be objectively and accurately determined. Therefore, stable color determination can be performed in terms of quality control as well, and a product without variations can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an apparatus used in a color determination method according to an embodiment of the present invention.

FIG. 2 is a histogram of R, G, B color signals relating to black, which is created by a histogram creating unit of the apparatus.

FIG. 3 is a histogram of R, G, and B color signals regarding white color created by a histogram creating unit of the same apparatus.

FIG. 4 is a histogram of R, G, and B color signals related to brown created by a histogram creating unit of the apparatus.

FIG. 5 is an explanatory diagram showing values of maximum brightness HR, HG, HB regarding a standard color sample created by a histogram creating unit of the apparatus.

FIG. 6 is a flowchart of a color determination process in the color determination method according to the present invention.

FIG. 7 is an example of a histogram obtained by measuring a covered wire.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Color determination device, 2 ... Covered wire, 6 light sources (lamp), 8 ... Imaging means (video camera), 14 ... Histogram creating means,
16 ... Maximum brightness detection means, 18 ... Color determination means.

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[Procedure amendment]

[Submission date] December 2, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

On the other hand, although the prior art has provided a device for judging the color of a plate-shaped object having a considerably wide color area (around several cm ² ), in this method, it is extremely difficult to detect the color like a core wire. It is difficult to accurately judge a color applied to a thin area (for example, a diameter is about 0.45 to 0.9 mm).

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of means used for a method for determining a color of a covered wire according to an embodiment of the present invention.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

In the figure, reference numeral 1 denotes the entire structure of the color judging means , 2 is a covered wire having a colored coating formed on its surface, 4 is a sample stage, and 6 is a covered wire. It is a lamp as a light source that irradiates light having a spectrum distribution identical to or close to natural light so that the illuminance on the surface becomes constant.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

Next, a method of determining the color of the covered wire using the configuration 1 of the color determining means will be described.

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

FIG. 1 is a diagram illustrating a hand used in a color determination method according to an embodiment of the present invention.
It is a block diagram of a stage .

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] Explanation of code

[Correction method] Change

[Correction content]

[Explanation of Codes] 1 ... Configuration of color determination means , 2 ... Covered wire, 6 light sources (lamps),
8 ... Imaging means (video camera), 14 ... Histogram creating means, 16 ... Maximum brightness detecting means, 18 ... Color judging means.

[Procedure Amendment 8]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

Claims (1)

[Claims] 1. A coated wire is irradiated with light having a spectral distribution that is the same as or close to natural light so that the illuminance on the surface is constant, and the light is irradiated with a fixed light. After imaging the inside of the area, taking out each color signal of R, G, B, and creating a histogram of the lightness distribution of these R, G, B based on each color signal of these R, G, B, respectively. Find the maximum brightness of the histogram,
A method for determining the color of a covered wire, characterized in that the color of the covered wire is determined based on a combination of the respective maximum brightness values of R, G, and B.