JPH0476625B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a three-dimensional photometry device that measures the three-dimensional distribution state of reflected light or transmitted light from a sample.

[Prior Art] Conventionally, a variable angle photometer shown in FIG. 8, for example, is known as a device for measuring the three-dimensional distribution state of reflected light or transmitted light from a sample.

The variable angle photometer projects parallel light beams (2 to 25 mm in diameter) from a light source 3 onto a sample 2 placed on a sample stage 1, and detects the reflection from the sample 2 by a light receiver 4 rotating around an incident point O. Continuously captures light or transmitted light,
The sample 2 is tilted and reflected light or transmitted light from a number of surfaces having different angles from the incident surface is continuously captured to measure the three-dimensional distribution state of the reflected light or transmitted light from the sample.

[Problems to be Solved by the Invention] However, according to the above-mentioned conventional apparatus, due to the mechanical scanning of the light receiver 4 and the tilting of the sample 2, reflected light or transmitted light from the incident plane and a number of planes having different angles from the incident plane There is a problem in that it requires a long time to measure.

Therefore, the present invention aims to provide a three-dimensional photometry device that enables short-time measurement.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a screen on which reflected light or transmitted light from a sample is projected, and a distribution state of the reflected light or transmitted light passing through the screen. The two-dimensional area sensor to be photographed, the position error due to the screen of the image photographed by the two-dimensional area sensor, and the collimation error due to the two-dimensional area sensor are determined by the known three-dimensional distribution of reflected light or transmitted light from the standard plate. A computing unit that calculates the three-dimensional distribution state of reflected light or transmitted light from the sample by correcting it based on the difference between the state and the distribution state photographed by the two-dimensional area sensor, and records the calculation results of the computing unit. It is equipped with a recorder for recording.

[Operation] According to the above means, the three-dimensional distribution state of reflected light or transmitted light from the sample is measured by electrical scanning using the two-dimensional area sensor.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 7.

FIG. 1 is a schematic diagram of a three-dimensional photometry device that measures the three-dimensional distribution of reflected light from a sample.

In the figure, reference numeral 10 denotes a sample placed on a sample stage 12 inside a casing 11, and a parallel beam of variable luminous flux (diameter 2 to 25 mm) is projected onto the sample 10 from a light source 13. The sample stage 12 is rotatable about a vertical axis in order to change the direction of parallel light rays projected onto the sample 10, and the light source 13 is rotatable around the incident point O in order to change the incident angle of the parallel light rays onto the sample 10. It is rotatably provided.

Reference numeral 14 denotes a screen onto which the reflected light from the sample 10 is projected, and a two-dimensional area sensor 15 is arranged behind the screen 14 to photograph the distribution state of the reflected light passing through the screen 14. Then, the signal from the two-dimensional area sensor 15 is input to a computing unit (not shown), and the computing unit calculates the position error due to the screen 14 of the image photographed by the two-dimensional area sensor 15 and the two-dimensional area sensor 1
5 is corrected, the three-dimensional distribution state of the reflected light from the sample 10 is calculated, and the calculation result is recorded by a recorder (not shown).

Here, the position error caused by the screen 14 and the collimation error caused by the two-dimensional area sensor 15 are corrected as follows.

That is, as shown in FIG. 2, if the reflected light emitted from the light source L and reflected by the sample S is measured on the spherical surface A centered on the incident point O, then
Although it does not cause any error, in reality plane B
In order to project upward, the spherical surface A is used as shown in Figure 3.
A deviation between the upper position and the position on the plane B, that is, a positional error due to the screen 14 occurs.

In addition, since the reflected light passing through the screen B shown in FIG. A deviation from the distribution state, that is, a collimation error caused by the two-dimensional area sensor 15 occurs. This collimation error includes one due to a difference in the material of the screen 14. That is, when the light passing through the screen 14 is completely scattered, the transmitted light flux is normally smaller than the reflected light flux, as shown in Figure 4a, but in reality, it is as shown in Figure 4b. This is because the transmitted light flux is often relatively larger than the reflected light flux, as shown in FIG.

The position error due to the screen 14 of the image photographed by the two-dimensional area sensor 15 and the collimation error due to the two-dimensional area sensor 15 are caused by the reflected light from a standard plate such as a compressed MgO powder plate or a BaSO ₄ plate. Correction is made based on the difference between the known three-dimensional distribution state and the distribution state photographed by the two-dimensional area sensor 15 similarly to the sample 10.

A compressed material used as a standard plate for reflected light.
As shown in Figure 5, the reflected light from the rough surface of the MgO powder exhibits an ideal diffuse reflection distribution state, with the reflected light flux dlr from the micro-rough surface da and the direction perpendicular to the rough surface in the observation direction. There is a proportional relationship between the inclination θ and the solid angle of observation dw: dlr/da = B・cosb・dw (B is the proportionality coefficient indicating the brightness of the rough surface) (this can be expressed as
Lambert's cosine law. ) holds true.

Further, the compressed MgO powder surface used as a standard plate for the luminous intensity distribution of reflected light exhibits a reflected luminous intensity distribution state as shown in FIG.

Furthermore, compressed MgO powder used as a standard plate for the luminance distribution of reflected light exhibits a luminance distribution state as shown in FIG.

Therefore, by using a standard plate with known luminous intensity distribution, brightness distribution, or relative reflectance (specular reflection is set to 100%) distribution of reflected light, it is possible to determine the three-dimensional luminous intensity distribution of reflected light from a sample. The state and brightness distribution state can be measured in real time.

In addition, in the above embodiment, a case was described in which the three-dimensional distribution state of the reflected light from the sample was measured, but the present invention is not limited to this, and a screen and a two-dimensional area sensor may be placed behind the sample. It is also possible to measure the three-dimensional distribution of transmitted light.

[Effects of the Invention] As described above, according to the present invention, the three-dimensional distribution state of reflected light or transmitted light from a sample is measured by electrical scanning using a two-dimensional area sensor.
Measurement time can be significantly reduced compared to conventional devices.

[Brief explanation of drawings]

Figures 1 to 7 show one embodiment of the present invention. Figure 1 is a schematic diagram of a three-dimensional photometer for reflected light, and Figure 2 shows the positional error due to the screen and the observation by the two-dimensional area sensor. Fig. 3 is an explanatory diagram of the quasi-error, Fig. 3 is an explanatory diagram of the position error, Figs. FIG. 7 is a diffuse reflection distribution diagram, a reflection luminous intensity distribution diagram, and a brightness distribution diagram of compressed MgO powder, respectively, and FIG. 8 is a schematic configuration diagram of a conventional apparatus. 10...Sample, 12...Sample stand, 13...Light source, 14...Screen, 15...Two-dimensional area sensor.

Claims (1)

[Claims] 1. A screen on which the reflected light or transmitted light from the sample is projected, and a two-dimensional area sensor that photographs the distribution state of the reflected light or transmitted light passing through the screen.
The position error due to the screen of the image taken by the two-dimensional area sensor and the collimation error due to the two-dimensional area sensor are calculated using the known three-dimensional distribution state of the reflected light or transmitted light from the standard plate and the two-dimensional area sensor. The apparatus is equipped with an arithmetic unit that corrects the three-dimensional distribution state of reflected light or transmitted light from the sample based on the difference from the distribution state photographed by the sample, and a recorder that records the calculation results of the arithmetic unit. A three-dimensional photometric device featuring: