JPS62204223A - Spatially light separating photometer - Google Patents

Abstract

PURPOSE:To make it possible to supply equal light beams to two photometric optical systems through different courses without using a semitransparent mirror by irradiating light to be measured to two adjacent faces of a rotary polygon mirror and reflecting equal beams in two direction. CONSTITUTION:Noticing that an inclined angle formed by two adjacent faces of the rotary polygon mirror 20 having N faces in 3604o/N and an angle (light guiding angle) formed by two reflected light beams of incident light made incident from the same direction on the two adjacent faces in 720 deg./N, equal spatially separated scanning light beams are simultaneously led into two optical systems. A light beam 15 radiated from a light emitting point is made incident upon an incident slit 41 at first in accordance with the rotation 26 of the rotary polygon mirror 20, and finally a light beam 16 radiated from a light emitting point 12 is made incident upon an incident slit 41 along a circular arc 19 passing the center of a light emitting source. Light is similarly made incident also to an incident slit 46. Consequently, the quantity of light to be used can be increased twice without increasing the size of the rotary polygon mirror 20 and a semi-transparent mirror or a light dividing means which may generate the loss of light can be omitted because equal light can be supplied to the two photometric means through different courses.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a photometric device, and more particularly to a spatially resolved photometric device using two surfaces of a polygonal rotating mirror.

[Background of the invention]

Conventional spatially resolved photometry devices either arrange multiple photometric optical systems in parallel according to their spatial resolution, or use a multifaceted rotating mirror to spatially scan light and introduce it into a single photometric optical system. . However, in the former case, the spatial resolution is, for example, 10
As the price increases, the number of photometric optical systems increases, making them complicated and expensive, and there are disadvantages in that differences in detection sensitivity of the photometric systems occur. In addition, since the latter method does not perform simultaneous photometry, it is in principle suitable for measuring weak energy light.
In particular, when the scanning light was simultaneously introduced into different photometric means, for example, two spectrometers with different wavelength ranges, the brightness was further halved if the scanning light was divided into two by a half-transparent mirror.

[Purpose of the invention]

An object of the present invention is to eliminate the drawbacks of the prior art, by irradiating measurement light onto two adjacent surfaces of a multifaceted rotating mirror and reflecting an equal amount of light in two directions, using a semi-transparent mirror. The object of the present invention is to provide a bright spatially resolving photometer that can be introduced into two photometering optical systems.

[Summary of the invention]

In the present invention, the inclination angle between two adjacent surfaces of the N-plane rotating mirror is 3.
60°/N, and the angle formed by the two reflected lights on the two surfaces of the light incident from the same direction (light guiding angle) is 720°/N. It is designed to introduce spatially resolved scanning light.

[Embodiments of the invention]

FIG. 1 is an explanatory diagram of one embodiment of the present invention.
The light from 0 passes through a polygonal rotating mirror 20 driven by a motor 25.
The light is incident on two surfaces 21.22 and is split into optical axes 23.24 facing a condenser lens 30.35. Condensing lens 30.35
The light 31.degree. 36 focused by the spectrometer 40.45 enters the entrance slit 41.degree. 46 of the spectrometer 40.45, and is photometered within the spectrometer 40.45.

According to the rotation 26 of the rotating mirror 20, the light ray 15 emitted from the light emitting point 11 initially enters the entrance slit 41, follows the arc 19 passing through the center of the light emitting source, and finally the light ray 1 from the light emitting point 12 enters the entrance slit 41.
6 enters the entrance slit 41. The same applies to the entrance slit 46.

Figure 2 shows the number of angles N of the polygon forming the polygon, the division angle θ at the center of the polygon, the single light angle formed by two reflected lights from two adjacent surfaces, and the angle of incidence on the mirror surface θ/2. This is a table showing the decrease in efficiency that occurs because the angle of incidence is not 0°, that is, the incidence is not normal.

If N is small, the light guide angle can be large, but the efficiency is low, and the number of times the space is scanned per rotation of the rotating mirror is small. On the other hand, if N is large, the efficiency and number of scans will increase, but the light guide angle will decrease, making it difficult to design the optical direction of the light to the rotating mirror.

On the other hand, the maximum dimension of the multifaceted rotating mirror 20 is limited by the precision of the mirror grinding machine, and the larger the number of faces, the lower the effective area (corresponding to the opening area) of one image.

Considering these conditions, the light guide angle is 90° and the efficiency is 0.
It is concluded that an eight-sided rotating mirror (N-8) with a diameter of 9 or more is advantageous.

According to the present invention, instead of using a multi-faceted rotating mirror with an area of 2, which is almost impossible due to processing constraints, the brightness can be effectively doubled by simultaneously using two sides of the original-sized rotating mirror. can be obtained.

Furthermore, as shown in this example, since the optical paths guided to the two spectrometers are different, it is possible to use condensing lenses made of different materials even when the wavelength ranges of the light passing through the two optical paths are different. be.

Chromatic aberration can also be reduced compared to conventional semi-transparent mirror systems that share both wavelength ranges.

Although a dispersive spectrometer is used as the photometric means in FIG. 1, a combination of a filter spectrometer and a photoelectric detector may also be used.

〔Effect of the invention〕

According to the present invention, the amount of light used can be doubled without increasing the dimensions of the polygonal rotating mirror. Furthermore, since the same amount of light can be supplied to the two photometric means through separate paths, there is no need for a semi-transparent mirror or light splitting means that would cause a loss in the amount of light.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention, and FIG. 2 is a table of light guiding angle and efficiency with respect to the number of surfaces N of a rotating mirror. DESCRIPTION OF SYMBOLS 10... Light source, 20... Polygonal rotating mirror, 19... Scanning arc, 25... Drive motor, 30, 35... Condensing lens, 40.45... Spectrometer.

Claims (1)

[Claims] 1. A photometric device that scans space by rotating a polygonal rotating mirror, which has at least two condensing optical systems, and has light that is simultaneously incident on two adjacent surfaces of the polygonal rotating mirror. A spatially resolved photometry device characterized in that light to be measured is introduced into at least two photometry optical systems. 2. In the spatially resolved photometry device according to claim 1, the polygonal rotating mirror is an octagonal cylindrical (8-sided) rotating mirror,
A spatially resolved photometry device characterized in that two light guide directions differ by approximately 90 degrees. 3. A photometric device that scans space by rotating a polygonal rotating mirror, which has at least two condensing optical systems, and collects at least two light beams to be measured that are simultaneously incident on two adjacent surfaces of the polygonal rotating mirror. A spatially resolved photometry device characterized by being introduced into a spectroscopic optical system. 4. The spatially resolved photometric device according to claim 3, wherein the two spectroscopic optical systems are a visible polychromatic spectrometer and an ultraviolet polychromatic spectrometer.