JPS6013229A - Industrial colorimeter - Google Patents

Abstract

PURPOSE:To perform accurate colorimetry, by separately changing the lighting angles and lighting directions of a plurality of light source parts. CONSTITUTION:A plurality of, e.g., four light sources 1...1''' are connected to independent power sources, respectively. In comparison with the case where only one light source 2 is used in an optical system, illuminance four times larger than in said case is obtained. Since the effect of external light is hard to receive, a dark room is not required. Colorimetry can be performed accurately in the open state. Since the lighting angle can be changed depending on the state of the surface of a sample, the incident angles of the light beams from two facing light sources are made to be, e.g., 20 deg., and the angles of the other two are made to be, e.g., 45 deg. with respect to the highly glossy surface. Therefore, the effect of the texture of the surface of the sample and the effect of the state of the sample on a line are not received. Thus the accurate colorimetry can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method for continuously moving samples in an open environment under indoor lighting in a coloring process line such as coloring, painting, printing of colored steel plates, colored aluminum, etc. or dyeing of fibers. The present invention relates to a colorimeter that accurately measures color, detects even slight color differences, and manages the colors of products on the line.

The conventional color measurement method is to hold the sample at 45° or 0
The principle is to perform accurate color measurement by receiving the diffusely reflected light that is generated by irradiating the sample at an incident angle of 50°. However, accurate color measurement cannot be performed unless the light irradiating the sample is strictly constant, so it is recommended to measure color in a dark room. Alternatively, it is necessary to place the optical system in close contact with the sample to prevent external light from entering. Under such technical circumstances, there are still no examples of methods and devices for color measuring moving objects. However, in recent years, it has become necessary to control the color of objects flowing through a conveyance line during the coloring process, and color measurement techniques for moving objects have become important.

In view of the industrial trends described above, the inventor has repeatedly studied a method for measuring the color of a moving object on a coloring process line. Examples of coloring process lines that require color management include colored metal plates, painted or printed plates, and dyed fibers. The following factors are considered to have an adverse effect when measuring the color of these moving objects. That is, (1) directionality of the sample surface;
(2) texture of the sample surface, (3) condition of the sample on the line, (4) contact problem between the sample surface and the optical system,
(5) the influence of external light during colorimetry; and (6) the illumination and light reception conditions of the conventional optical system. Next, looking specifically at each of these factors, regarding (1), the surface of metal plates such as steel plates and aluminum plates has large vertical and horizontal directions due to the manufacturing process, and the surface is colored, painted, or printed. The sample also has strong directionality in the warp and width5, and the fabric has strong directionality due to the warp and weft relationships. When such a sample moves along a line, accurate color measurement is not possible due to variations in reflected light that occur depending on the direction. Regarding (2), there is a phenomenon in which a textured surface, a fiber layered surface, or a raised fabric surface looks different depending on the incident angle of illumination light and the viewing angle. This is a phenomenon that occurs because there are shadow areas due to the undulations of the surface structure, and the state in which the light from the light source is reflected regularly is complicated. If such a sample is illuminated at a fixed angle, color differences cannot be reproduced, resulting in color measurement results that do not match visual perception, making it impossible to perform correct color management. Regarding (3),
The sample on the coloring process line flows at various moving speeds from tens of meters to several meters per minute, and vertical movement (shaking) occurs because the back surface of the sample is open space. However, because of the colored layer that adheres to the sample surface, it is impossible to press down from above, and therefore it is impossible to stop the sample from moving up and down. Also, the line direction may be tilted due to factors such as the weight and sag of the sample.

In such a state, color management is impossible under conventional illumination and light reception optical conditions due to changes in the amount of light received due to changes in the distance to the sample. Regarding (4), for example, the sample surface on the line in processes such as anodic oxidation film treatment, painting treatment, printing, dyeing, etc. is in an unfinished state and is in an unstable state where it is easily damaged. Therefore, conventional colorimetric methods that require the optical system to be in close contact with the sample surface cannot be applied. Regarding (5), when using a conventional colorimeter, it is necessary to block any light other than the irradiated light, which has strict specified conditions, but when measuring the color of a sample on a line, it is not necessary to block any light other than the irradiated light. It's impossible. Regarding (6), the optical conditions of the conventional method are the reception of diffusely reflected light in the vertical direction with respect to illumination with an incident angle of 45°, or the reception of diffusely reflected light with respect to vertical illumination, but in this conventional method, (2) (3) (4
) Problem (5) cannot be solved.

As explained above, the present invention provides an industrial colorimeter that can perform accurate colorimetry by solving the problems that naturally occur when applying conventional colorimetry methods to colorimetry of objects on a moving line. provide. That is, the gist of the present invention is to enable the illumination angle and illumination direction of a plurality of illumination light source sections each having a light source connected to an independent power source to be changed separately, so that the illumination can be brightly illuminated so that the influence of other light can be ignored. In addition, by receiving diffuse reflected light in the vertical direction, it eliminates the influence of factors that make colorimetry inaccurate, such as blurring of the directional conveyance line on the sample surface. Eliminates the need for close contact.

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partially sectional side view of a colorimeter according to the present invention, and FIG. 2 is a plan view thereof. In Figures 1 and 2, the upper and lower circumferences formed by the variable illumination direction guide knoll (hereinafter simply referred to as guide rail 8.8') are both in a horizontal position, forming the upper and lower ends of the spherical belt, and Four variable illumination angle guide rails (hereinafter simply referred to as guide rails g, g/, g/) connect these circumferential guide rails.
/.

9#) is a curved line that is perpendicular to the guide rails 8, 81 and follows a spherical zone surface with the guide rails 8, 81 as the upper and lower circumferences, and the guide rails 8, 8/
It can slide freely along the line and can be fixed at a specific position.

This sliding movement allows the direction of illumination to be changed freely.

The illumination light source parts 1, 1', 1", 1/l are respectively attached to guide rails 9, 9', 9", y", and the upper end circumference (guide rail 8) and lower end circumference are arranged along each guide rail. It can slide between the peripheries (guide rails 81) and can be fixed at a specific position.This sliding allows you to freely change the illumination angle. Light receiving part 4 with vertical center line up
to be fixed. The center line t passes through the center C of the sphere, and the light receiving part 4
The center line of the integrating sphere 5 lens 6 and the lower inter-light receiver built in the lens shall be on the upper side. There is one light source 2 in each illumination light source section, and its light passes through a lens 3 and becomes parallel light.
pass through. The line sample 11 moves on the guide roller 10 in the direction of the arrow. Each of the four illumination light sources is connected to an independent power source.

Having described the present invention in detail above, the features of the present invention will now be described.

The colorimeter of the present invention is set so that the color measurement target position on the sample surface coincides with the center C. For example, if the line sample has a wrinkled surface or is a fabric with a lot of naps,
If one set of opposing light sources is illuminated with an incident angle of 45° and the other two opposing light sources are illuminated with an incident angle of 20°, there is no shadow when viewed from the aperture T of the light receiver that receives light in the vertical direction. In the coloring or dyeing process, it is possible to accurately control the color matching of the sample.

Each of the four lighting sources is connected to an independent power source, so
All conventional optical systems will have four times the illuminance compared to using a single light source. Since the illumination angle can still be changed depending on the condition of the sample surface, for example, for a high gloss surface, the incident angle of the opposing 2sl light source illumination should be set to 2.
It is possible to set the two light sources at 0° and the other two at 45°, and depending on the characteristics of the tissue on the sample surface, for example, the brightness of the two light sources in the horizontal direction can be set to be different from the brightness of the two light sources in the line direction. You can adjust the illuminance by making it brighter.

The optical system of the present invention differs from conventional optical systems in that it does not need to come into contact with the sample surface, and the aperture 1 at the tip of the light receiver in FIG. The width can be selected appropriately.

The four light sources that directly illuminate the sample surface from a close distance are connected to independent power supplies, so compared to the conventional method in which one light source is reflected by a mirror and illuminated from two directions, the brightness on the sample surface is 4. The illuminance is more than twice as high, and the sample is illuminated with an illuminance hundreds of times higher than the indoor lighting installed in the line example.

The device of this embodiment has four illumination light sources that can set the direction and angle freely with respect to the measurement target location on the line, and these light sources are connected to an independent power source, so it is possible to illuminate with three light sources. Individual or single illumination is also possible.

The advantages of using the present invention have been listed above, and the main effects are summarized as follows.

The illuminance on the sample surface is bright enough that it is not affected by indoor lighting, and unlike conventional methods it is not affected by external light, so a dark room is not required and color can be measured accurately in an open state.

Since the illumination direction and illumination angle can be freely set according to the type and condition of the measurement sample, there is no influence from the structure of the sample surface or the condition of the sample on the line, which are disadvantages of conventional methods.

Since the illumination angle, illumination direction, and light source illuminance can be changed according to the structure of the sample surface to illuminate the sample under the optimal conditions, the surface reflected light from the sample is uniform, and this light is received from the vertical direction. Even if the sample surface shakes within ±5 degrees in the vertical direction and the line has an inclination within ±1.5 degrees, accurate color measurement can be performed without affecting the measured value.

Since the sample surface is irradiated from four directions, there are no shadows caused by the directionality of the sample surface and the tissue, resulting in a uniform illumination state. Accurate color measurement is possible by receiving light from the vertical direction of the sample under uniform illumination.

If the sample on the line is paint, it can be measured just after it has been applied, or if it is dyed, even if it is still wet, the optical system does not come into contact with it, so it can be measured without affecting the sample surface.

The ability to freely select the number of illumination light sources to turn on can also expand the range of applications, such as detecting the state of the sample surface by emphasizing the directionality of the sample surface, depending on the purpose of use.

The results of comparing the performance of the industrial colorimeter according to the present invention with a conventional colorimeter will be explained. The measurement samples used were a colored steel plate produced on a factory line and a reflective sort with retroreflectivity used for road sign boards.

Measurement 1 (using a conventional colorimeter) Find the color difference between the value measured at the normal sample position (the position of the sample stage of the optical system) and the value measured with the sample 5 cm horizontally away from that position. Also, the color difference was calculated between the value measured by lifting one side of the sample so as to be inclined at 1.5 degrees with respect to the sample stage and the value measured at the normal sample position.

Measurement 2 (using the industrial colorimeter of the present invention) With respect to the measured value at the reference sample position (when placed horizontally at a specified distance from the optical system), as in Measurement 1, 5 rMl was added horizontally.
The color difference between the case when it was released and the case when it was tilted by 1.5 degrees was measured.

The above measurement results are shown in Figure 3 for the color steel plate and Figure 4 for the reflective sheet. With a conventional colorimeter, when 5 degrees are separated, 1.
In both cases when tilted by 5 degrees, the color difference is large and cannot be used for line colorimetry. On the other hand, according to the industrial colorimeter of the present invention, the maximum color difference was 0.34, which proved to be accurate enough for on-line color control.

[Brief explanation of drawings]

Fig. 1 is a partial cross-sectional side view of the colorimeter of the present invention, Fig. 2 is a top view of the colorimeter, Fig. 3 is the measurement results of a color steel plate sample, and Fig. 4 is a partial cross-sectional side view of the colorimeter of the present invention.
The figure shows the measurement results for a reflective sheet sample. 1.1'L1" 1///...Illumination light source section, 2
...Light source, 3...Lens, 4...
...Receiver section, 5...Integrating sphere, 6...Lens, 7...Receiver aperture, 8, 8'...
・Illumination direction variable is the idle rail, 9, 9', 9", 9"...Illumination angle suction uj you force guide rail, 10...Guide roller, 11
... Line sample, C ... Center of sphere, t
・・・・・・Perpendicular line passing through C. 1

Claims (1)

[Claims] a light-receiving unit that can move up and down along a perpendicular line passing through a colorimetric target point of a sample on a conveyance line and can be fixed to receive diffuse reflected light in the perpendicular direction of the colorimetric target point; The industrial metering device comprises a plurality of illumination light source sections whose illumination angles and directions can be independently changed and fixed, and the light sources of each illumination light source section are connected to independent power sources. Color meter.