JPS6212994Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an apparatus for measuring optical properties such as spectral transmittance and spectral reflectance of a sample.

There is a method that uses an integrating sphere as a general-purpose measuring method for measuring the transmittance of a transparent sample or a light-scattering sample, the reflectance of a glossy surface sample, the reflectance of a rough surface sample, and the like. When performing the above-mentioned integrating sphere measurements using a spectrophotometer for spectroscopic analysis, the integrating sphere is set in the sample chamber of the spectrophotometer, which significantly reduces the space in which the sample can be set, and the size of the sample increases. Shape is limited. FIG. 1 shows a configuration for performing measurements using an integrating sphere using a normal spectrophotometer for spectroscopic analysis. M1 and M4 are sector mirrors, R is a reference beam, S is a sample beam, D1 is a photodetector, and SC is a sample chamber. In normal usage, the reference light beam R and the sample light beam S alternately enter the photodetector D1 via optical paths indicated by dotted lines. When performing measurements using an integrating sphere, the integrating sphere I and attached mirrors M5, M6,
A device consisting of M7 is installed, and a reference light beam R and a sample light beam S are made to enter the integrating sphere I, and the light inside the integrating sphere is extracted from a direction perpendicular to the plane of the drawing and is made to enter the photodetector D2. To measure the transmittance of a sample, place the sample cell cs on one side of the entrance window of the integrating sphere I, place the reference cell cr on the other side of the entrance window, and set the standard white plate at the positions Ws and Wr. Sample cell for reflectance measurements
Remove cs and control cell cr, place the measurement sample at Ws, and place the control sample at Wr. In this configuration, the measurement sample Ws is limited to a size that fits within a portion of the remaining space outside the integrating sphere in the sample chamber SC, and a photodetector D2 is required in addition to the photodetector D1. In order to alleviate such restrictions on the shape and size of the sample and to reduce the number of photodetectors to one, an apparatus configuration as shown in FIG. 2 is used. I is an integrating sphere in the shape of a broken sphere and is provided in contact with the sample chamber SC, so that the reference light beam R and the sample light beam S are made to enter the integrating sphere I in parallel with each other. A control sample Wr is placed on the rear wall of the integrating sphere I at a position where the control beam R and the sample beam S are incident.
and a window for setting the measurement sample Ws,
Light inside the integrating sphere I is extracted from a direction perpendicular to the plane of the drawing and is made to enter a photodetector D. cr is control cell, cs
is used in the sample cell when measuring the transmittance of a liquid sample. M1 is a sector mirror that divides the output light of the spectroscope into a reference beam and a sample beam. In this configuration, the space in which the sample Ws is set can be expanded freely because there is no optical system behind it, but the surface where the measurement sample Ws is set and the surface where the control sample Wr is set intersect at an acute angle θ. Therefore, if the measurement sample is too large, it will hit the control sample, and it is not possible to measure any sample. Interference in the shapes of both the control and measurement samples can be avoided by increasing the intersection angle of the planes on which both the control and measurement samples are set, but since both the control and sample light beams are incident on the integrating sphere I in parallel, the control and measurement samples are Also, the intersection angle of the planes on which each measurement sample is set cannot be too large.

The present invention was made with the aim of further expanding the degree of freedom regarding the shape and size of a sample compared to the conventional example described above, in order to further enhance the versatility of a spectrophotometer using an integrating sphere. The present invention will be explained below with reference to Examples.

FIG. 3 shows an embodiment of the present invention. L is the light source,
m is a spectrometer. M1 is a sector mirror that divides the emitted light beam from the spectrometer m into a sample light beam S and a reference light beam R. Sample chamber SC so that sample light flux S passes through
is placed, and an integrating sphere I is placed in contact with the rear surface of this sample chamber.
is arranged so that the sample light beam passing through the sample chamber SC is incident on the integrating sphere I. Contrast luminous flux R
is reflected by mirrors M2 and M3 and enters the sample chamber SC.
The integrating sphere I
incident on . In the integrating sphere I, a measurement sample installation window w1 is provided on the wall opposite to the entrance window for the sample light flux S, and a control sample installation window w2 is provided on the wall opposite to the entrance window for the reference light flux R. If necessary, a reflection sample chamber RC may be installed in contact with the outer surface of the integrating sphere I on the side opposite to the sample chamber SC. When the reflective sample chamber RC is not used or when the reflective sample chamber RC is detachable, a flat flange is installed around the window w1 to place the measurement sample in contact with the window w1 and prevent light from leaking or entering. F is installed. D is a photodetector.

FIG. 4 shows another embodiment of the invention. Components corresponding to those in the embodiment shown in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted. This embodiment differs from the embodiment shown in FIG. 3 in that an optical fiber Opf is used instead of mirrors M2 and M3 to guide the reference beam to the integrating sphere I by bypassing the sample chamber SC.

In each of the above embodiments, when measuring the transmittance of a sample, the measurement sample cs (cell for liquid sample in the figure) is placed in the sample chamber SC.
A reference sample (cell) cr is placed in contact with the entrance window of the integrating sphere I in the optical path of the reference beam R. In the sample chamber SC, the reference light flux R detours around the outside, so there is no need to place a reference sample, and there is no risk of the reference light flux being blocked by the measurement sample, so measurements can be taken even with a measurement sample that fills the sample chamber. , This is one of the features of the present invention. In the case of transmittance measurement, a white board is set at the reflectance measurement sample Ws and the control sample Wr.

In the case of measuring the reflectance of a sample in each of the above embodiments, cells for transmittance measurement, etc., such as CS and CR are removed, and a control sample is set at Wr, and a measurement sample is set at Ws. In this case, since there is nothing behind the measurement sample Ws, the measurement sample installation space has a semi-infinite extent. Furthermore, since the surfaces on which the control sample and the measurement sample are set are perpendicular to each other, there is no fear that the surface to be measured of the measurement sample Ws will come into contact with the control sample Wr even if the surface to be measured is arbitrarily wide. Therefore, there is a large degree of freedom in determining the shape and size of the sample to be measured. This is the main feature of the invention. The sample for reflectance measurement is the surface coating of the finished product itself, and its shape and size cannot be determined at all, but this invention allows us to evaluate its true value in measuring reflectance. Demonstrate. In addition, when measuring the reflectance of a mirror, if the sample is set in contact with the window w1 of the integrating sphere, the incident sample light flux will be reflected and exit directly from the entrance window of the integrating sphere, so it is necessary to set the sample at a slight angle. However, the reflected light must be trapped within the integrating sphere. In this case, there is no problem if it is a small mirror, but if it is a large mirror, even if you tilt it slightly, other parts of the mirror will hit various places, making measurement difficult.
According to the device of the present invention, the space in which the sample Ws is set is semi-infinite, so measurements can be made without any inconvenience.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are plan views of different conventional examples, respectively.
3 and 4 are plan views of different embodiments of the present invention, respectively. SC...Sample chamber (for transmission), I...Integrating sphere, RC
...Reflection sample chamber, D...Photodetector, S...Sample light flux, R...Reference light flux, Ws...Reflection measurement sample, Wr
...Reflection control sample.

Claims (1)

[Scope of utility model registration request] The sample chamber and the integrating sphere are placed adjacent to each other, so that the sample-side light flux passes through the sample chamber and enters the integrating sphere, and the control light flux bypasses the sample chamber in a direction perpendicular to the sample-side light flux. so that it is incident on the integrating sphere from
A sample optical property measuring device that has a measurement sample installation window on the wall opposite to the sample chamber of the integrating sphere, and a control sample installation window on the wall opposite to the reference beam incidence window of the integrating sphere.