JPS6310509Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement of an integrating sphere type reflected light measuring device used for measuring spectral reflectance, color, etc. of a sample.

Generally, white light is produced using a prism or a diffraction grating.
It is used in conjunction with a spectrophotometer that separates the light in steps of 10 nm in the ultraviolet and visible wavelength range from 250' to 800 nm, irradiates the sample with the above-mentioned light beam, detects the intensity of the diffuse reflection spectrum as an electrical signal, and calculates the ratio of the sample. A device called an integrating sphere type reflected light measuring device is used to obtain reflectance curves and the like. This integrating sphere has an inner wall with a uniform reflectance and a completely diffuse reflection surface.It measures the reflection spectra of opaque samples such as paint, plastic, fibers, etc. under 7° incident/diffuse light, which is also the measurement condition of the JIS standard. It can be measured using the integrating sphere method. For this incident light with an incident angle of 7° (±5°) on the sample surface, the specularly reflected light that is reflected at a reflection angle of 7° (±5°) is generated when the sample has a high surface area, such as a metal plated surface or a vapor-deposited film. Not only in cases where the sample has a reflectance, but also in the case of a sample such as a paint or plastic which has a high reflectance, the specularly reflected light component in the total reflected light is large, reducing measurement accuracy. In such cases, it has traditionally been possible to freely switch between two types of measurements: measurement of diffuse reflected light excluding specular reflected light from the sample, and measurement of total reflected light including specular reflected light. is necessary. For this purpose, the optical trap shown in Figs. 1 and 2 is removably installed on a part of the integrating sphere, that is, on the inner wall where the specularly reflected light from the sample surface is irradiated.
It is necessary to switch between excluding and including specular reflection light with the trap. Figure 1 is a cross-sectional view showing a commonly used method, where 1 is a cross section (part) of an integrating sphere, 2 is an incident light window, 3 is an incident light, and 4 is a cross-sectional view showing a commonly used method.
is specularly reflected light that is irradiated from a sample (not shown) onto the inner wall of the integrating sphere at a reflection angle of 7°. 5 is a trap hole of the integrating sphere drilled at the irradiation position in 4 above, 5W is a female thread of the hole, 6 is a light trap/white plate mounting tube that is screwed into this female thread 5W, and 7 is a conical light trap. The inner surface is coated with matte black paint or covered with light-absorbing material such as lace cloth. 8 is a reflective white plate, which is diffusive and has almost the same reflectance as the inner wall of the integrating sphere.After measuring the specularly reflected light on the optical trap 7 side as described above, unscrew 6 from 5W. When the reflective white plate 8 is screwed in, it becomes part of the inner wall 1 of the integrating sphere, and total reflection light can be measured. FIG. 2 is a cross-sectional view showing the conventional method of screwing and sliding, in which a flat plate part 10 is joined to a cylindrical body 9, and a cylindrical light trap 11 and a reflective white plate 8 are moved in different positions in the same direction. It is set up. An operating handle 12 is slid in the direction of arrow a via a support mechanism (not shown), and the trap hole 5 of the integrating sphere is selectively blocked by the trap 11 and the reflective white plate 8. However, these optical traps 7 and 11 have a sufficient inner diameter d and depth (l≧100 mm) to completely eliminate the specularly reflected light 4.
However, the sliding type shown in FIG. 2 has the disadvantage that a sufficient size cannot be obtained due to restrictions on the arrangement of other parts of the device when moving the trap section. Furthermore, the screw-in type shown in FIG. 1 has a conical optical trap 7, which not only does not provide a sufficient trapping effect, but also has the drawback that the operation of replacing the optical trap and the white plate is more troublesome and less efficient than the sliding type. In either method, this trap mechanism occupies a large amount of space on the device.
At present, it is not possible to attach other additional devices to this part, and this is an obstacle to downsizing the device.

This idea was made in view of the above-mentioned current situation, and it eliminates the drawbacks of the specular reflection light removal trap of the conventional integrating sphere type reflected light measuring device, and achieves a complete optical trapping effect with a simple mechanism in a small space. The present invention aims to provide a device equipped with an optical trap that is easy to operate. In other words, light is irradiated onto a sample placed as part of the inner wall of an integrating sphere, and the diffuse reflected light excluding specular reflected light from the sample and the total reflected light including specular reflected light are measured alternately. The apparatus includes a light hole provided at a position of the integrating sphere corresponding to the specularly reflected light from the sample, a case whose inner wall is made of a light absorbing material and always covers the outside of the light hole, and an inner wall formed from an integrating sphere. A light passage hole cover made of a diffuse reflection member having the same reflectance as the inner wall of the sphere is provided, and the light passage cover is movably provided in the case so as to freely open and close the light passage hole. This is related to a spherical reflected light measuring device.

Embodiments of this invention will be described below with reference to the drawings. FIG. 3 is a plan view illustrating the first embodiment of the apparatus, and FIG. 4 is a side sectional view taken from FIG. 3. 1
is an integrating sphere, and is a hollow sphere with an inner diameter of, for example, 200 mm, whose inner surface is coated with magnesium oxide, etc., 2 is an incident light window, 3 is incident light, 4 is specularly reflected light, 5 is a trap hole of the integrating sphere, and 8 is a reflective white plate. This is the same as that explained in FIGS. 1 and 2. C is the spherical center point of the integrating sphere, 13 is the sample, and 14 is the measurement window of the integrating sphere. In most cases, the above-mentioned incident light 3 is monochromatic light separated by a spectrometer (not shown), and the center point O of the sample 13 and It is incident on the normal line OC connecting the center point C of the sphere at a projection angle θ. This projection angle θ is set to, for example, 7° as described above. Of the reflected light from the sample 13, the reflected light with a reflection angle equal to the above projection angle (θ=7°) is the specular reflected light 4, and the reflected light with other reflection angles (indicated by the dotted line in the figure) is the diffuse reflected light. It is 15. Another window 16 of the integrating sphere is the reflected light exit window of the sample 13.
7 is a photodetector that converts the energy intensity of the emitted reflected light (spectrum) into an electrical signal, and a photomultiplier tube is usually used. The above configuration is the same as the conventional device, and the trap hole 5 is provided at the position where the specularly reflected light 4 irradiates the inner wall of the integrating sphere, as explained in FIGS. 1 and 2. The essential parts of this invention are a trap hole closing mechanism that supports the above-mentioned reflective white plate 8 in the trap hole 5 and makes it movable, and an optical trap mechanism that does not provide the trap hole 5 with an optical trap mechanism unlike the conventional device. , the following optical trap was used. That is, as shown in FIG. 4, when the trap hole 5 is opened, the specularly reflected light 4 (indicated by the dotted line) emitted from the trap hole 5 is absorbed by applying a light absorbing material, such as black rasher cloth 22, to the inner surface of the case of the integrating sphere or the outer case 21 of the device. By pasting or applying matte black paint, the specularly reflected light 4 is completely absorbed. In this configuration, the distance l from the hole 5 to the case 21 can not only be easily set to the above-mentioned 100 mm or more, but also the cylindrical trap 4 (second
As shown in 11) in the figure, there is no restriction on the inner diameter d, and the above l does not necessarily need to be 100 mm or more. Next, we will discuss the hole closure mechanism.
The trap hole blocking plate 23 is a plate-like member that supports the reflective white plate 8, and its material and shape are not limited to those shown in the drawings. 24 is an operation stick that engages with the above 23, and 25
The bearing is slidably supported in the direction of arrow b. 26 is the block operation handle and integrating sphere case 2
The trap hole is opened and closed from the outside of the trap. With this configuration, the blocking plate 23 is switched between the position shown by the solid line and the position shown by the dotted line, making it possible to measure reflected light excluding the specularly reflected light 4 and to measure total reflected light including the specularly reflected light 4.

Next, another embodiment of this invention will be explained with reference to FIG. In the figure, the description of the same reference numerals as in FIGS. 3 and 4 will be omitted. However, the case 21 is shown as a small case with l≈100 mm that covers only the trap hole of the integrating sphere, but it may also be used as the same case as in Figs. 2 and 3. This embodiment is similar to the above-mentioned point in that the trap hole blocking plate 31 supporting the reflective white plate 8 is configured to be able to be opened and closed from the outside of the device to the position indicated by the dotted line 31' using a hinge 32 as a fulcrum by an operation mechanism (not shown). The difference is that the effect is exactly the same.

The above is an explanation of the structure and operation of the two embodiments of this invention, but this invention is not limited to the contents shown in the drawings and explanations. For example, if the inner wall of the integrating sphere is white, the reflective white plate may be used as a white plate. Therefore, if it is silver, it should be made into a silver plate as well.

Further, in the above embodiment, the case where the incident light is monochromatic light has been described, but the light passage cover of this invention can also be used when the incident light is an undivided luminous flux such as white light. In that case, in the apparatus shown in FIG. 4, a white light source is placed in place of the photodetector 17, and the reflected light exit window 16 is used as the incident light window to pass the white light through the window and integrate the white light as shown in the figure. The reflected light is made to enter the sphere 1, and the reflected light is emitted through the incident light window 2 shown in the figure as a reflected light output window, and is transmitted through a spectrometer not shown in the figure.
A detector may be placed in place of the light source in the apparatus shown in the figure.

This idea is structured as above, so
We have solved the drawbacks of the optical trap mechanism used in conventional integrating sphere reflected light measuring devices to selectively measure diffuse reflected light, which removes specular reflected light, and total reflected light, which does not remove specular reflected light.We have developed a simple mechanism that takes up little space. The present invention provides a convenient device which has a trapping effect comparable to that of extremely large optical traps, is easy to operate, and can be miniaturized.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a screw-in trap mechanism of a conventional integrating sphere type reflected light measuring device, FIG. 2 is an explanatory diagram of a conventional sliding optical trap mechanism, and FIG. 3 is a plan view of an embodiment of the device of this invention. FIG. 4 is a sectional side view of FIG. 3, and FIG. 5 is a structural explanatory diagram of another embodiment of the device. 1... Integrating sphere, 2... Incident light window, 3... Incident light (incident angle to sample surface 7° ± 5°), 4... Specular reflection light from sample (reflection angle 7° ± 5°) , 5... Specular reflection light extraction hole (light hole), 8... Diffuse reflecting plate (for example, reflective white plate) having the same reflectance as the inner wall of the integrating sphere, 1
3...Sample, 14...Measurement window of integrating sphere, 15...
Diffuse reflected light other than specularly reflected light, 16...Reflected light exit window, 17... Photodetector, 21... Integrating sphere case or device case, 22... Light absorbing material on the inner wall of the case (for example, black lace fabric) , 23... Specular reflection light extraction hole blocking plate (diffuse reflection plate support part of 8 above), 24, 25, 26... The above blocking plate sliding operation mechanism, 31... Specular reflection light extraction hole blocking plate (door type ), 32...the above hinge.

Claims (1)

[Scope of utility model registration request] A device that irradiates light onto a sample placed as part of the inner wall of an integrating sphere and selectively measures diffuse reflected light excluding specular reflected light from the sample and total reflected light including specular reflected light. , a light hole provided at a position of the integrating sphere corresponding to the specularly reflected light from the sample, a case whose inner wall is formed of a light absorbing material and always covers the outside of the light hole, and an inner surface of the integrating sphere. A light passing hole cover made of a diffuse reflection member having almost the same reflection as a wall is provided, and the light passing hole cover is provided movably within the case so as to freely open and close the light passing hole. Spherical reflected light measuring device.