JPS6334420B2 - - Google Patents

Description

Claim 1: The luminous flux emitted from the luminous flux generating device enters the objective reflector through the entrance hole of the case, the objective reflector is arranged to block the path of this emitted luminous flux, and then this luminous flux An optical structure in which the light source of the generator enters the intermediate image forming device, is reflected, returns to the objective reflector again, follows its final path and exits the device through an exit hole adjacent to the entrance hole of the case. In the target multi-path device, the light beam generating device 2
The intermediate image forming device for the light source includes two mirrors 16, 17 with different curvatures on which an intermediate image of the light source is formed;
29, 30, and 2 of the condenser
The mirrors are arranged so that the light beam reflected from the objective mirror is sequentially reflected by the two mirrors of the condenser, and then returns to the objective mirror again. An optical multipath device, characterized in that the angle of incidence of the beam 1 on the mirror 29 is smaller than the angle of incidence of the beam 1 on the mirrors 16, 30 with smaller curvature.

2. Optical multipath device according to claim 1, characterized in that in the condenser, the mirror 16 is a plane mirror, whereas the other mirror 17 is a concave mirror.

3. The optical multi-path device according to claim 1, wherein the mirrors 29 and 30 of the condenser 15 are both concave mirrors.

4. The luminous flux emitted from the luminous flux generator enters the objective mirror through the entrance hole of the diaphragm, the objective mirror is arranged to block the path of this radiated luminous flux, and then this luminous flux enters the optical flux of the luminous flux generator. Optical multiplexing of the structure in which the intermediate image of the light source enters the imaging device, reflects and returns again to the objective reflector, following its final path and exiting the device through the exit hole adjacent to the entrance hole of the diaphragm. In the route device,
The intermediate image forming device of the light source of the light flux generating device 2 consists of a light condenser having two mirrors 16, 17; 29, 30 with different curvatures on which an intermediate image of the light source is formed. The two mirrors are arranged so that the light beam reflected from the objective mirror is sequentially reflected by the two mirrors of the condenser, and then returns to the objective reflector again. Luminous flux 1 for 17,29
The incident angle of the light beam 1 is made smaller than the incident angle of the light beam 1 on the mirrors 16 and 30 with smaller curvature, and
In order to measure the reflectance of the plane 9, the sample 39 is mounted on a support 38 and arranged so as to block the path of the emitted light beam 1, and when measuring this, the objective reflector 31 is Rotating shaft 33 located at the sample position
is rotated around , the emitted light beam 1 is made to alternately enter the objective reflector 31 and the condenser 15 through reflection on the sample plane, and the emitted light beam 1 is directed directly to the exit hole 43 on its final path. Optical multipath device featuring features.

5 The objective reflector 31 is rotatable around a rotation axis 33 along the arc of an arm 32, and the arm 32 is rotatably and coaxially attached to the support 38 of the sample 39, and its end 5. The optical multipath device according to claim 4, further comprising an objective reflector 31 supported in the optical multipath device.

TECHNICAL FIELD This invention relates to the optical device manufacturing industry, and more particularly to optical multipath devices.

BACKGROUND ART Nowadays, optical multipath devices, which are characterized by a very long optical path for light, are used in infrared spectroscopy for testing gases with low concentrations or gases with extremely weak absorption bands. It has become an indispensable part of the meter. Such a device can be used for both qualitative and quantitative analysis.

Currently, one prior art for optical multipath devices is known, which involves directing the light beam emitted from a light source of a beam generator into an objective reflector through an inlet hole in a case, which The light beam is rotatably mounted to cross the path of the light beam, and the light beam is further incident on the intermediate image forming device of the light source of the light beam generator and then returned to the objective reflector.
This is an optical multi-path device configured to pass through a series of multi-paths before exiting the device through an exit hole in the case of the device. In this device, the intermediate imaging device of the light source of the beam generator has two plane mirrors, which are arranged at an angle to each other.

However, in the above-mentioned device, when the intermediate image of the light source of the beam generator is formed, the peripheral light of the beam is not captured by the plane mirror, and therefore a considerable amount of the light in the emitted beam passes beyond the objective reflector. Scatter (this causes the light flux to become blurred).

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a device that can improve the luminous flux transmittance of an intermediate image forming device of a light source of a luminous flux generating device and can easily adjust the number of luminous flux paths.

The purpose of this is to make the luminous flux emitted from the luminous flux generator enter the objective reflector through the entrance hole of the case of the device, and this objective reflector is mounted so as to be rotatable around the axis of the radiated luminous flux, and the luminous flux is further transmitted to the luminous flux generator. The present invention is directed to an optical multipath device in which a light source is directed to an intermediate image forming device, from there back to an objective reflector, and repeatedly through multiple paths before exiting through an exit hole in a case. Based on
A composite light condenser is provided in the intermediate image forming device of the light source of the light flux generating device, and this condenser is composed of two mirrors with different curvatures, and these are appropriately arranged to form a mirror with a large curvature. This can be realized by making the angle of incidence of the emitted light beam on the mirror smaller than the angle of incidence of the emitted light beam on a mirror with a small curvature.

It is necessary to take care that one mirror of this condenser is flat and the other mirror is concave. It may be required that both mirrors of this concentrator be concave.

In order to improve the operating mode of the optical multipath device of the present invention, a sample held in a holder is placed across the path of the emitted light beam and the reflectance of the plane of this sample is measured, and the objective reflection At the time of measurement, the mirror is rotated along an arc around its axis to make the emitted light beam alternately incident on the objective reflector and the condenser, and after repeating this a predetermined number of times, this light beam is finally transferred to the device. It can be directed directly to the exit hole of the case.

In addition, an objective reflector is supported at one end of an arm coaxially and rotatably attached to the sample holder.
It is equally reasonable to use this arm to rotate the objective mirror around its own axis and along an arc.

The invention makes it possible to prevent the series of emitted light beams from becoming blurred, no matter how many light beam paths there are within the device. Another way to look at this is to improve the brightness transmission of the device and to make the device insensitive to the number of paths of the emitted light beam.

Furthermore, the invention simplifies the adjustment of the number of radiation beam paths, thereby allowing the device to be preset more precisely in the number of beam paths.

In addition, it should be noted that the present invention can be used as a means to more accurately measure the reflectance of flat samples with small dimensions.

[Brief explanation of the drawing]

1 is an overall vertical cross-sectional view of an optical multipath device according to the present invention, FIG. 2 is a cross-sectional view taken along the line - of FIG. 1, FIG. 4 is a front view of a condenser of an optical multipath device according to the present invention, FIG. 5 is a longitudinal cross-sectional structural view of an optical multipath device according to the present invention, and FIG. 6 is a front view of a condenser of an optical multipath device according to the present invention. FIG. 7 is a general perspective view of the adjustment stage when the path device is operated as a reflectometer; FIG. FIG.

BEST MODE FOR CARRYING OUT THE INVENTION As a preferred embodiment of the present invention, a case in which there are six emitted light flux paths will be described in detail below with reference to the drawings.

FIG. 1 shows an optical multi-path device. In this device, a light beam 1 emitted from a light beam generator 2 passes through an inlet hole 3 (a first and Fig. 2).
This entrance is for entering the objective reflector 6 (FIGS. 1 and 3).

The objective reflector 6 is fixed in a holder 7 at a position where it crosses the path of the radiant beam, and the number of paths of the radiant beam is adjusted by pushing this with a screw 11. passes through the cover 12 of the case of this device. To adjust this, screw 11
This is done by rotating the knob 13 connected to. The elongated member 10 is secured by a flat spring 14 secured to the cover 12.

The condenser 15 (FIGS. 1 and 2) is arranged so as to cross the path of the light beam reflected by the objective reflector.
This condenser 15 has two mirrors with different curvatures, one of which is a plane mirror 16 and the other is a concave mirror 17. Since the mirrors 16, 17 are properly positioned, the angle of incidence of the emitted light beam on the concave mirror 17 is smaller than the angle of incidence on the plane mirror 16. The angles of incidence of the light beam 1 on the mirrors 16, 17 of the composite condenser are chosen to be different from each other. The reason is that the optical multipath device of the invention is operated in the infrared range of the spectrum, where the angle of incidence of the light beam 1 on the mirror 17 of the complex concentrator with a relatively large curvature is It is set to be smaller than that of 16. However, if this condition is not met,
Distortion appears in the image from the exit hole.

In particular, the image will be defocused and distorted at the output point from the device. The angle of incidence is less important as far as the composite concentrator mirror 16 with a flat surface or small curvature is concerned, having a relatively large angle of incidence compared to that of the mirror 17. Both mirrors 16 and 17 are fixed to the lid 4 by a holder 18. The outlet hole 19 is the inlet hole 3 of the lid 4.
The emitted light beam, which is provided in a higher position and has passed the final path in the device, exits the device through this exit hole 19. The window 20 fits into the hole 3, 19, which is transparent for a given radiation beam.

The objective reflecting mirror 6 forms intermediate images 21 and 22 of the light source (not shown) of the light flux generating device 2 on the surface of the concave mirror 17, and these intermediate images 21 and 22 are relative to the center of curvature 23 of the objective reflecting mirror 6. Occupy a symmetrical position.

If the number of paths of the emitted light flux is 10 (10 times the length), then
The objective reflector 6 converts four intermediate images 24, 25, 26, 27 of the light source of the light beam generating device into a condenser 15 (first
(Fig. 4). The center of curvature 28 of the objective reflector 6 lies between these intermediate images 25,26.

In another embodiment of the optical multipath device of the invention, the light concentrator 15 (FIG. 5) has two different curvatures.
It has concave mirrors 29 and 30, and these concave mirrors 29,
30 is attached to a holder 31, and this holder 31 is fixed to the lid 4. Since the mirrors 29 and 30 are appropriately positioned with respect to the emitted light beam 1, the angle of incidence of the emitted light beam on the concave mirror 29, which has a large curvature, is smaller than the angle of incidence of the emitted light beam on the concave mirror 30, which has a small curvature.

Yet another embodiment is an optical multipath device (FIGS. 6 and 7) that operates as a reflectometer with six paths for the emitted light beam. In this device, the objective reflector 31 is connected to the arm 32 is movably mounted on one end, while the other end is mounted on a pivot shaft 33;
is fixed to the base 34 so as not to move. The holder 18 of the condenser 15 is fixed to a bed 35, and this bed 35 is fixed to the rotation axis 33 of the arm 32 so as not to move. A rotating support 38 is installed so as to cross the radiation beam passing through the orifice of a diaphragm 37 (not shown in this case), and the support is attached to the rotation shaft 33 and supports the specimen 39 (FIG. 7). The flat side of this specimen (not shown)
The reflectance of is measured. Diaphragm 37 (6th
7) is provided on the bed 35.

An angle scale 40 is engraved on the end of the bed 35 on the objective reflector 31 side.
A pointer 41 for reading 0 is fixed. When the sample 39 (FIG. 7) is set on the support 38 and the objective reflector 31 is rotated along an arc by the arm device 32, the emitted light beam 1 is reflected by the sample 39 and then passes through the objective reflector 31. and the light condenser 15 alternately, and directly reach the exit orifice 43 (FIGS. 6 and 7) of the diaphragm 37 in the final path. The concave mirror 17 shows an intermediate image 44, 45 of the light source of the beam generator 2 (FIG. 1).

When this optical multipath device is adjusted so that the paths of the emitted light beam are six paths and is used for spectrum analysis of gas, it operates as follows.

The case 5 (FIG. 1) of this device is filled with the gas under test. Luminous flux 1 emitted from the luminous flux generator 2
enters the objective reflector 6 through the window 20 of the entrance hole 3, and this luminous flux forms an intermediate image 2 of the light source of the luminous flux generating device 2.
1 (FIG. 2) is imaged on the upper part of the concave mirror 17 of the condenser 15, and then reflected by the plane mirror 16. Mirror 16,
The emitted light beam 1 reflected at 17 and thickened is again directed to the objective reflector 16 and reflected there, and is then reflected by the concave mirror similarly to the intermediate image 22 (FIG. 2) of the light source of the light beam generator 2 (FIG. 1). The image is tied to the bottom of 17. The emitted light beam is further reflected by a plane mirror 16 and sent to an objective reflector 6.
, where it is reflected and finally exits the device through the exit hole 19.

If two concave mirrors 29 and 30 are used as the condenser, it is possible to compensate for the distortion of the image of the light source of the light beam generating device 2 due to aberration. This optical device is similar to that described above.

According to the invention, the condenser 15 is itself provided with optical multiple paths, thereby preventing image blurring in this device.

The objective reflector 6 is connected to its rotation axis 8 (Figs. 1 and 5).
When rotated around the center of curvature 23
(Fig. 2) and 28 (Fig. 4) are the condenser 15
It moves along the surfaces of concave mirrors 17 and 29 (FIGS. 1 and 5). When the center of curvature of the objective reflector 6 (FIGS. 1 and 5) relative to the direction of the junction of the mirrors 16, 17 and 30, 29 of the condenser 15 moves, the number of paths in this device increases. . Second
When the center of curvature 23 of the objective reflector 6 shown in the figure is at this position, the number of paths of the light beam is six, and the fourth
When the center of curvature 28 of the objective reflector 6 shown in the figure is at this position, the number of paths of the light beam in the multipath device is 10, and the intermediate images 24, 25, 26, 27 of the light source of the light beam generator 2 are formed continuously.

When this optical multi-path device has six paths and is used as a reflectometer, the objective reflector 3
1 (FIGS. 6 and 7) is different in its operating position with respect to the condenser 15.

The objective reflector 31 (Fig. 6) of this reflectometer is
The measuring operation is carried out in the same manner as described above without placing the sample, and the signal of the emitted light beam 1 is taken out at the exit hole 43 of this optical device.

The sample 39 (FIG. 7) is then aligned with the support 38 in order to measure its plane reflectance, while the arm 32 is used to move the objective reflector 31
is moved along an arc surrounding the center of the rotation axis 33, and the emitted light flux reflected by the sample 39 is made to enter the objective reflector 31. The positions of this objective reflector 31 and sample 39 are determined by the angle scale 40 on the base 35 of this device.
This is indicated by the guideline 41. The emitted light beam reflected by the objective reflector advances toward the sample 39 again, is reflected by this sample 39, and heads toward the condenser 15, whereupon an intermediate image 4 of the light source of the beam generator is placed on the condenser 15.
4,45 is imaged. The operation of each component of the multipath optical device with the paths configured in this manner is exactly the same as in the case without a sample described above, except that the emitted light beam 1 is reflected by the sample 39. When the intensity I ₁ of the signal I is determined by measuring the amount of transmission at the exit of this device, it is proportional to the reflectance of the sample and decreases according to the number K of paths taken by the light beam. The reflectance R of sample 39 is given by the following formula: Find it by.

Industrial Applicability The present invention is most useful in increasing the sensitivity of a spectroscopic measuring device for infrared absorption spectra.

Furthermore, the present invention can be applied to a fast-acting, high-precision optical-acoustic gas analyzer, especially for quantitative measurement of air pollution, without using a spectrometer, which is important in the context of environmental conservation. It is.

Furthermore, the invention can be applied to measure the reflectance of flat samples with high precision by reducing the reflection angle, which has great benefits for laser technology and high-energy equipment.