JPH06100503B2 - Probes such as colorimeters - Google Patents

Description

The present invention relates to a probe such as a colorimeter, and more specifically,
An attempt is made to obtain a probe such as a colorimeter that projects diffused light onto a sample and can extract reflected light from the sample, which enables easy and accurate measurement.

Conventionally, various types of probes such as colorimeters and surface roughness measuring instruments have been provided, but they can be roughly classified into the following three types.

As shown in FIG. 3, the light is projected from the light projecting portion (2) into the integrating sphere (1) through the light projecting opening (3a) and diffused by the inner wall, and the sample measuring opening of the integrating sphere (1). The sample (S) exposed to the integrating sphere (1) from the portion (3b) is irradiated with the diffused light, and the reflected light from the sample is provided on the outside of the light receiving opening (3c). ) Is an integrating sphere type that receives light.

As shown in FIG. 4, the sample (S) is irradiated with light from the light projecting portion (2) through the lens (5), and the reflected light is an optical system by the half mirror (6) and the condenser lens (4). Built-in detector that leads to the detector (7).

As shown in FIG. 5, the light emitting portion (2) formed by an optical fiber and the light receiving portion (8) also formed by an optical fiber are provided at a fixed angle so as to face the sample (S), respectively. Type.

Among these probes, the integrating sphere type has at least a projection opening (3a), a measurement opening (3b), and a reception opening (3).
Since the three openings of c) are required, there is a problem that the loss of the diffused light amount increases and highly accurate measurement cannot be expected. In addition, the projection opening (3a) and the measurement opening (3b) are arranged 90 ° apart so that the sample (S) is not directly exposed to the projection light, and both openings (3a) (3b) Since the light-shielding plate (A) is provided between them, the irradiation of the sample becomes asymmetric and the irradiation uniformity is poor, and it is difficult to measure with higher accuracy.

Furthermore, a reflective layer is formed on the inner surface of the integrating sphere (1) by coating barium sulfate or the like, but it is necessary to repeat the reflection several times in order for light to reach the sample side from the light projecting side. In order to secure a high irradiation amount, the lamp of the light projecting section needs to have a large capacity, which consumes a large amount of power and has a problem that the device easily breaks down due to heat generation. Moreover, the size of the integrating sphere (1) needs to be about 150 mm in diameter, and since it is heavy, it is difficult to freely scan the sample and it must be used as a fixed type.

Therefore, the sample must be set in the measurement opening (3b), and there is no degree of freedom in the setting direction, and in the case of a sample with a large area, a part of it must be cut out and set. The measurement was also troublesome. Further, the projection light has to pass through a complicated optical path from the light projecting section (2) to the condenser lens (4), and there is a problem that the measurement stability is poor.

In addition, since the reflection loss on the surface of the lenses (4) and (5) is large in the detector built-in type, the final light reception amount by the detector (7) is small and the measurement performance is inferior. There is a drawback in that the defocusing of the image or chromatic aberration as a coloring phenomenon occurs due to the dispersion action. Although it is possible to use an achromatic lens in order to eliminate this chromatic aberration, there are problems that the cost becomes high and the optical system becomes complicated.

Further, the light emitting section / light receiving section separation type has a limit in the light projecting angle of the fiber of the light projecting section (2) and can project only a narrow range, and the light receiving angle of the fiber in the light receiving section (8) is also limited. Therefore, there is a problem that only reflected light in a specific range can be received, the light collection efficiency is poor as a whole, accurate measurement cannot be performed, and the measurement sensitivity is poor. In addition, since the projection direction and the light receiving direction are deviated from each other, there is a problem that when measuring a sample having uneven surface such as a sample having uneven reflection, a shadow is generated and the measurement becomes more inaccurate.

The present invention is intended to solve the above-mentioned conventional problems. As its configuration, a light projecting portion is provided on one opening side of a cylindrical light reflecting portion, and the other opening side is close to a sample. As a measurement opening, on the side of the opening where the light projecting section is provided, there is provided a transmission type diffusion plate that is in contact with the opening and diffuses the projected light to introduce it into the light reflecting section. Is characterized in that an optical fiber for receiving the reflected light from the sample is inserted through the transmission type diffusion plate.

Next, embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a sectional view of the probe (P).

(10) is a tubular case, which is composed of a large diameter portion (11) in the upper portion and a small diameter portion (12) in the lower portion, and the boundary portion (13) is continuous in an inclined manner. The upper end surface of the large diameter portion (11) is closed by a lid (14), and the lid (14) is formed with a large number of heat radiation vent holes (14a). The small diameter part (12) is
The tip is formed with an opening, and a cylindrical light reflecting portion (50) is inserted therein. Reference numeral (15) is a hood fitted to the outer periphery of the tip of the small diameter portion (12), and protrudes from the tip of the small diameter portion (12) and contacts the sample (S).

The small diameter portion (12) and the large diameter portion (11) are screwed so as to be separable.

A light projecting portion (20) including a lamp (21) and a reflecting mirror (22) is provided in the large diameter portion (11) on the upper opening (X) side of the light reflecting portion (50). The light of the lamp (21) can be projected to the light reflecting portion (50) side. Further, the lamp (21) is arranged at the center of the axis of the light projecting portion (10) and is connected to a metal outlet (23) mounted on the outer circumference of the large diameter portion (11) so that it can be energized. (24) is the lamp (21)
The back plate is provided on the back surface, and (25) is a partition plate provided at the tip of the reflecting mirror (22).

On the upper opening (X) side of the light reflection part (50), a transmission type diffuser plate (which is in contact with the opening and can diffuse the light from the light projection part (20) and introduce it into the light reflection part (50) ( 30) is provided. The transmissive diffuser plate (30) is ground glass or opal glass in which minute irregularities are formed on one surface of quartz glass, and the projection light from the light projecting part (20) can be efficiently transmitted and diffused. There is. And transmission type diffuser plate (30)
An insertion hole (31) for an optical fiber (60) described later is formed in the central portion of the. It should be noted that it is preferable to provide a color complement conversion filter (40) or an interference filter below the transmission type diffusion plate (30) with a predetermined gap (about 1.5 mm), because more accurate measurement is possible. .

As the above-mentioned light reflection part (50), a transmission type diffusion plate (30)
This is for symmetrically and efficiently reflecting the diffused light diffused toward the sample (S), and a metal tube, a plastic tube, or a glass tube having a reflective surface formed by depositing chromium, aluminum, or the like on the inner or outer circumference. It is composed of a cylinder and the like. The lower opening (Y) side of the light reflecting portion (50) is configured as a measurement opening close to the sample (S).

Further, an optical fiber (60) is inserted through the insertion hole (31) of the upper transmission type diffusion plate (30) at the axial center position in the light reflection section (50).

The optical fiber (60) receives the reflected light from the sample (S) close to the measurement aperture and takes it out to the outside, and the end portion on the outside side is a detector (not shown) as a color discrimination means. ) Is connected to. The optical fiber (60) is made of a material such as quartz, glass or plastic.

Further, an auxiliary transmission type diffusion plate (30 ') is inserted into the tip of the optical fiber (60) so as to face the transmission type diffusion plate (30), and the insertion hole (31) of the transmission type diffusion plate (30) is inserted. At the same time as it is possible to diffuse the incoming light directly through the gap between the optical fiber (60) and the optical fiber (60), a part of the diffused light by the transmissive diffuser plate (30) is re-diffused. The auxiliary transmission type diffusion plate (30 ') is fixed with an adhesive or the like in a state where a through hole formed in the central portion is fitted and inserted into the outer periphery of the tip of the optical fiber (60). This transparent diffuser (3
0 ') is composed of, for example, so-called opal glass or frosted glass in which a milky white surface layer having a thickness of about 0.2 mm is formed on the upper surface of quartz glass, and the transmission type diffuser plate (30) on the upper side.
It is preferable that the diameter is ½ or less of that for uniform diffusion.

With the above configuration, the projection light from the light projecting section (20) is uniformly diffused by the transmissive diffuser plate (30) and the auxiliary transmissive diffuser plate (30 '), and the efficiency is improved by the inner reflection section (50). Since it is well reflected, it is possible to uniformly irradiate the sample (S) from any direction, such as the vertical direction, the horizontal direction, or the oblique direction, and the reflected light from the sample (S) is symmetrical at the center on the irradiation side. Since the light is received at, extremely accurate measurement is possible.

The partition plate (25) of the light projecting section (20) may be replaced with the partition plate (25) and a light quantity adjuster having a diaphragm function may be provided to perform the test. A wide variety of measurements can be performed according to the brightness of S). Further, if a light quantity monitor is provided in the light projecting section (20), it is possible to easily deal with the light quantity fluctuation due to the voltage fluctuation and the deterioration of the lamp (21), and more accurate measurement can be performed.

Further, the light reflecting portion (50) may be formed by directly vapor-depositing chromium, aluminum or the like on the inner peripheral surface of the small diameter portion (12).

In addition to this, various design changes can be made within a range that does not change the gist of the present invention, such as forming two or more transmission type diffusion plates (30).

According to the probe of the colorimeter or the like according to the present invention configured as described above, on one opening side of the cylindrical light reflecting portion, the projection light is diffused in contact with the opening portion and introduced into the light reflecting portion. Since the diffused light introduced through the transmissive diffuser from the above-mentioned opening is efficiently reflected by the light reflecting part, the projected light from the light projecting part is used as the diffused light on the sample. It is possible to irradiate efficiently, and moreover, it is possible to irradiate the sample evenly and uniformly, and it is possible to perform very accurate measurement. Further, since the optical fiber for receiving the reflected light from the sample is provided at the axial center in the light reflecting portion, the reflected light from the sample can be received symmetrically and uniformly, which enables more accurate measurement.

Moreover, since the optical path is linear, the number of reflections is small, and there is no extra aperture, the loss of projection light is very small, good measurement sensitivity and measurement stability can be secured, and the lamp output of the light projecting unit is also small. Therefore, the amount of power consumption can be reduced, the amount of heat generated is small, and the occurrence of device failure is unlikely to occur.

Also, because the probe itself can be made smaller and lighter, the probe can be pressed against the sample side for measurement, and it is easy to scan the sample. It becomes possible to measure. Furthermore, it is possible to perform measurement while moving the sample or probe, which facilitates automation.

Therefore, it is possible to solve all the problems of the probe such as the conventional colorimeter described above.

[Brief description of drawings]

FIG. 1 is a sectional view of a probe according to the present invention, FIG. 2 is a side view of the same, and FIGS. 3 to 5 are schematic views of a conventional probe. (10) …… Cylindrical case, (20) …… Projector, (21) ……
Lamp, (22) …… Reflector, (30) …… Transmissive diffuser,
(30 ′) …… Auxiliary transmission type diffuser, (50) …… Light reflecting part,
(60) …… Optical fiber, (P) …… Probe, (S) …… Sample, (X) (Y) …… Light reflector opening.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-50-81582 (JP, A) JP-A-53-46074 (JP, A) JP-A-53-52183 (JP, A)

Claims (4)

[Claims] 1. A cylindrical light reflecting portion is provided with a light projecting portion on one opening side, and the other opening side is used as a measurement opening close to a sample, and the light projecting portion is provided on the opening side. A transmission diffuser plate that contacts the aperture and diffuses the projected light and introduces it into the light reflection part is provided, and an optical fiber that receives the reflected light from the sample is located at the axial center position in the light reflection part. A probe such as a colorimeter, which is characterized by being inserted through a plate. 2. The probe for a colorimeter according to claim 1, wherein a light quantity adjuster is formed in the light projecting section. 3. A probe for a colorimeter or the like according to claim 1, wherein an auxiliary transmission type diffusion plate is fitted on the outer circumference of the optical fiber. 4. A probe for a colorimeter or the like according to claim 1, wherein the light projecting section is provided with a light quantity monitor for detecting fluctuations in the light quantity of the lamp.