JPS61226622A - Deciding device for color with gloss - Google Patents

Abstract

PURPOSE:To execute easily the color decision of the glossy substance which can not be executed by the conventional method by connecting the arithmetic unit to operate the color wave length of the measured substance based upon the output of the sensor. CONSTITUTION:On a measured substance 1, a light source part 2, an irradiating part 3 and a photodetecting part 4 are arranged, installed so that the light between those respective parts can be projected respectively by a certain constant angle, and a cover 5 is provided so that a disturbance light can not be made incident on the measuring point of the measured substance. On the other hand, in the photodetecting part 4, a sensor 12 is provided, this is connected to an external arithmetic unit 13 and the sensor 12 is constituted by arranging three photodetecting sensors 21-23 on the straight line. Out of three sensors, the sensor 21 at the central part is a color sensor, the sensors 22 and 23 at both edges are a visual light sensor having the sensitivity at the visual light. A color wave length lambdan is obtained by the operation in the arithmetic unit 13 based upon the output of the sensor 12.

Description

[Detailed Description of the Invention] [Industrial Application Field] Generally, gloss refers to the amount of specular reflection of light incident on the surface of an object and the sharpness of the specular reflection image. The present invention relates to a color determination device that considers only the magnitude of the amount of specular reflection.

[Prior Art] Generally, a shiny object causes total internal reflection, and Figure 8A shows this mode.It is usually called specular reflection, and the incident light beam φ exhibits a reflection that creates an image. .

On the other hand, when the object loses its luster, diffuse reflection occurs as shown in FIG. 8B, and the reflected light flux φ, that is, the amount of light on the light-receiving surface on the light-receiving side decreases.

In the case of this diffuse reflection, the angle θ,′(
An image is not created in the direction of the reflection center line AP, which is at θ, ).Furthermore, the spectral reflectance of various target objects, including metals, changes depending on the wavelength of the incident light source.

Therefore, the incident light flux φ in the case of FIG. The emitted light flux φ5 is actually a value φ11 that changes depending on the wavelength.
．． The specular reflectance ρ, which is expressed as φ5 and is a general evaluation method of glossiness, is also exactly as shown in the following equation.

Furthermore, in equation (1), since there is a spectral sensitivity in the light-receiving element that is actually measured, by substituting that term, the following holds true. Here, S is the spectral sensitivity of the light receiving element. λl and λ2 indicate the wavelength range of the light receiving element.

Also, to explain the definition of gloss measurement, gloss measurement methods include specular gloss Gs and contrast gloss Gc, and the specular gloss Gs considered here has a refractive index of 1.58.
The specular reflectance from the glass surface (perfectly reflective surface) of No. 7 is φ
Then, it can be obtained by the following formula.

ρ-5 Furthermore, if Gs(θ) is found in relation to equation (2).

In equation (4), φoze has a refractive index of 1.58.
In the reflected light flux from the glass surface of No. 7, θ indicates the incident angle and the reflection angle.

When detecting the color of such a glossy surface, the amount of light entering the light receiving element changes due to the influence of the gloss, making it impossible to accurately determine the color.

For example, the degree of baking in the baking process of bread in a bread factory is generally judged by its color, but when looking at this color, it is important to note that the gloss that results from coating the bread with oil, etc. cannot be determined.To deal with this,
One possible method is to see the color through ground glass, but
With this method, it is not possible to judge the condition of Komakaiyaki.

A similar problem also exists in the inspection of glossy paints.

[Problems to be Solved by the Invention] The present invention can measure the gloss of a target object, detect the amount of light on the light receiving surface of a light receiving element due to the influence of the gloss, and determine the color of the object from this detected amount. The present invention aims to provide a simple color determination device as described above.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the color determination device of the present invention optically separates a light source section, an irradiation section, and a light receiving section arranged on an object to be measured. At the same time as isolating the measurement point of the object to be measured, the measuring point of the object to be measured is covered with a cover that prevents disturbance light from entering, and the light from the light source provided in the light source section is converted into parallel light through a slit and a projection section, and then projected onto the object to be measured. A color sensor and a visible light sensor are installed in parallel to the sensor, and these sensors are configured to detect the color of the object to be measured based on their outputs. It is constructed by connecting an arithmetic device that calculates the wavelength.

[Operation] When light is irradiated from the light source onto the object to be measured and the reflected light is received by the visible light sensor and color sensor, calculations based on the outputs of each sensor can be performed by calibrating them in advance. It is possible to determine the color of the object to be measured through calculations performed by the device. In this case, since the cover prevents disturbance light from entering the measurement point on the object to be measured, color determination can be performed using a simple and inexpensive device without using a particularly bright light source.

[Embodiment] FIG. 1 shows an embodiment of the color determination device of the present invention. In this color determination device, a light source section 2 is placed on an object to be measured 1;
An irradiating section 3 and a light receiving section 4 are provided, and the light between these sections is installed so as to project at a certain angle, and a cover 5 is provided to prevent disturbance light from entering the measuring point of the object to be measured l. is provided.

Each of the above parts 2, 3.4 has a slit 7 and a shelter 8, respectively.
optically isolated by The position of the slit 7 is set to be at the focal point of the lens 9 provided in the irradiation section 3, and the slit itself has a vertically long slit shape. Further, the lens 8 has the role of collimating the light beam incident on the object 1, but an anti-polarization filter 10 is further provided to prevent polarization. On the other hand, in the light receiving section 4.

A sensor 12 is provided and connected to an external arithmetic device 113.

Note that the accuracy of the sensor 12 can be improved by designing the lens diameter to be as small as possible in accordance with the size ratio of the sensor 12. The anti-polarization filter 10 has the function of irradiating light energy in a straight line onto the irradiation surface of the object, although it is not always necessary.Furthermore, a cushion 14 is provided between the cover 5 and the object 1 to prevent damage to the object. At the same time, measures are being taken to block external light.

When the object l is irradiated with light from the light source 15 in this state,
Light is emitted onto the object 1 in a vertically elongated manner in proportion to the shape of the slit. Assuming that the shelter 8 is installed perpendicularly to the object surface between the irradiating section 3 and the light receiving section 4,
When the object is a perfectly reflective surface, the optical path is θ, = θ
,', and the radiant energy is concentrated in the direction of θ,'.

Next, the configuration of the sensor 12 will be explained.

The sensor 12 shown in FIG. 2A is constructed by arranging three light receiving sensors 21, 22, and 23 on a straight line. Among these three sensors, the sensor 21 located at the center is a color sensor, and the sensors 22 and 23 at both ends are visible light sensors sensitive to visible light.

If the color sensor 21 is an R, B, G separation type color sensor, rather than arranging it in a straight line like this, red, red, and red lights are placed around the visible light sensor 24 in the center as shown in Figure 2B.
It is preferable to arrange blue and green color sensors 25, 28, and 27, and naturally the shape of the slit in FIG. 1 will change accordingly.

The major difference between the sensors shown in FIGS. 2A and 2B is that they include one or two visible light sensors. Both measure the amount of light, but in FIG. 2A, the average value of the outputs of a pair of visible light sensors is taken as the amount of light. If a rough measurement is acceptable, it is natural that the visible light sensor shown in FIG. 2A can be used as a single visible light sensor as shown in FIG. 2B. Hereinafter, only the case where the sensor shown in FIG. 2A is used will be described.

During measurement, glass with a refractive index of 1.587 is used as the object in order to calibrate the sensor. Generally, it is difficult to keep such glass on hand due to maintenance issues, so it is better to use a white surface with a known 1-spectral reflectance as a substitute.Hereinafter, this will be referred to as the standard white surface. When a standard white surface is displayed using the apparatus shown in FIG. 1, the outputs of the visible light sensors 22 and 23 of the outputs of the sensor 12 output energy related to . Assuming that the spectral characteristics of this visible light sensor have ideal characteristics that form a rectangular shape as shown in Figure 3, the outputs of the two visible light sensors can be considered to be approximately the amount of light on the color sensor. I can do it. Furthermore, the reference voltage value is determined so that the color sensor 21 becomes white. In the case of FIG. 2B, adjustments are made so that all R, B, and G color sensor outputs are made equal. After performing these calibrations, the measurement described below begins.

Figure 4 shows a standard white surface (solid line) and an arbitrary measured object (
The more glossy the object to be measured, the closer the height B of the dashed line is to A. Conversely, when the object is no longer shiny, the object irradiation Diffuse reflection occurs on the wearing surface, the amount of light on the light receiving surface decreases, and the height B of the broken line becomes smaller. This ratio is (4)
It has almost the same value as Eq. That is, 4. Therefore, using the output value of the visible light sensor, the arithmetic unit 13 of FIG. 1 calculates the equation (6), and from the result, the rough glossiness of the object to be measured can be determined.

Next, a method for determining colors using the ratio in equation (6) above will be described.

When determining a color, it is assumed that the output of the color sensor 21 is known in advance by a monochromatic light spectral characteristic measuring device (FIG. 5), and the output of the sensor is corrected from that value. Furthermore, since the spectral characteristics of the visible light sensors 22 and 23 can be calculated by the spectral characteristics measurement device for monochromatic light at the same time, the values are also stored in the calculation device 13.

In Figure 6, the solid line shows the spectral characteristics (at height α) measured by a monochromatic light spectral characteristic measuring device, and the broken line shows the measured value when an arbitrary object to be measured is shown.The color when an arbitrary object is shown. Let the output of the sensor 21 be X, and let Xn be the value obtained by multiplying this output In the graph of FIG. 5, the wavelength λn corresponding to Xn at that time becomes the desired color wavelength.

This color wavelength ^n is determined by calculation in the calculation device 13 based on the output of the sensor 2.

Next, the case of the three-color separable color sensor shown in FIG. 2B will be described. In this case, there is no need to perform calibration using a monochromatic light spectral characteristic measuring device.

That is, when the standard white surface is shown, the output ratio is red, blue,
Assume that the green sensors are R, B, and G, respectively.

R+B+G ”°(7) y= □
Fist ・ ・ (8) R+B+G R+B+G ”° (9) This is because the R, B, and G outputs can be converted into xy chromaticity coordinates by calculating. When calculating equation (6), A standard white surface makes the above values equal (0.
One calibration can be completed by adjusting the output of the sensor as shown in 3).

After the calibration is completed, the output characteristics of each color sensor when an arbitrary object is shown are shown by broken lines R and B in FIG.

It becomes like G. In this output, Gs obtained by method (6)
When multiplied by the reciprocal of , the values become R', B', and G', and by substituting these values into the formula below, the true x, y chromaticity coordinates can be found.

R'R"+B'+ G・ ---(10) G' y=--...(11) R'+ B"+ G'B'2"R・10B・10G・ --- -(12) The above devices are not designed to accurately measure luminous flux, but were developed for the purpose of simply measuring the color of glossy objects.

[Effect of the invention] According to the color determination device of the present invention detailed above.

Using a simple device, it is possible to easily determine the color of a shiny object, which was impossible using conventional methods.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the color determination device of the present invention, FIGS. 2A and B are front views of a senna used in the color determination device,
3 to 7 are diagrams for explaining the operation of the arithmetic device according to the present invention, and FIGS. 8A and 8B are diagrams for explaining general light reflection. 1Φ・Object to be measured, 2@・Light source section, 3.. Irradiation section, 4.. Light receiving section, 5.. Cover, 7. Fist slit. 12...Sensor, 13...Arithmetic device, 15...Light source, 21, 25-27...Color sensor, 22.23.24 Fist/Visible light sensor. Figure 2A Figure 2B Figure 3Figure 5Figure 6Figure 7Figure 8A Figure 8B

Claims (1)

[Claims] 1. Optically isolate the light source section, irradiation section, and light receiving section placed on the object to be measured, and at the same time cover the measurement point of the object to be measured with a cover that prevents disturbance light from entering. The light from the provided light source is made into parallel light through the slit and the projection section, and then projected onto the object to be measured, and the light can be received by a sensor in the light receiving section provided in the direction of reflection, and the sensor includes a color sensor. 1. A color determination device with gloss, characterized in that a visible light sensor and a visible light sensor are arranged in parallel, and a calculation device that calculates the color wavelength of an object to be measured based on the output of the sensor is connected to these sensors.