JPH0743459B2 - Reflective optics - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coaxial reflection condensing optical system for condensing light rays emitted from an object or celestial body to measure the visual field of the object or celestial body and to project the object or celestial body. Regarding

[0002]

2. Description of the Related Art As a conventional coaxial reflection / focus optical system,
For example, there is known an optical system described on pages 231 to 233 of "Optics" (first edition) by Hiroshi Kubota, published by Iwanami Shoten, 1964.

This optical system is known as a coaxial Cassegrain reflection optical system. As shown in FIG. 3, a concave reflecting mirror 4 having a through hole 41 and having a positive power, and a negative power. And a convex reflecting mirror 5 having an incident light ray from an object or a celestial body are reflected by the concave reflecting mirror 4 and the convex reflecting mirror 5 to form an image at a condensing position 11. The incident pupil image 20 of the incident light ray 2 in this optical system has a shape in which the central portion of the incident light is shielded 21 by the convex reflecting mirror 5, as shown in FIG.

Further, as an optical system for projecting an astronomical image by a coaxial reflection optical system while measuring the visual field of a light ray incident on the reflection optical system, the "Infrared Technology" No. 16 published by the Japan Infrared Technology Research Group in 1989. The optical systems described in No. 1 and 2-18 are known.

This optical system, as shown in FIG.
A concave reflecting mirror 4 having a
In addition to the projection optical system, a second measurement optical system including a condenser lens 12 and a light receiving element 13 having a position measuring function is provided.

In the first projection optical system shown in FIG. 4, an incident ray 2 from an object or an celestial body is a concave reflecting mirror 4.
And, the incident pupil image 20 of the incident ray 2 is reflected by the convex reflecting mirror 5 and is focused on the condensing position 11. As shown in FIG. 5, the convex reflecting mirror 5 shields 21 the center of the incident light. It becomes a shape.

The second measuring optical system is arranged adjacent to the first projecting optical system, and the converging optical system optical axis b of the second measuring optical system is the first projecting optical system. The incident light beam 21 that is arranged parallel to the reflection optical system optical axis a of the optical system and enters the second measurement optical system is collected on the light receiving surface of the light receiving element 13 that is perpendicular to the light collection optical system optical axis b. Be illuminated. Since the light receiving surface of the light receiving element 13 has a position measuring function, the focal length of the condenser lens 12 and the incident angle of the incident light ray 21 are calculated.

[0008]

However, in such a conventional optical system, when the intensity of the incident light from the object or the celestial body is extremely strong, the amount of incident light absorbed by the back surface of the convex reflecting mirror 5 increases. Then, there is a problem that the temperature of the convex reflecting mirror 5 rises and the amount of deformation of the convex reflecting mirror 5 due to heat increases.

Therefore, the present invention reduces the amount of incident light absorbed by the convex reflecting mirror 5 even when the intensity of the incident light from the object or the celestial body is extremely high, and further, the incident light image forming function and the incident light are made with a small aperture. The objective is to obtain a reflective optical system having a function of measuring the position of a light beam.

[0010]

In order to achieve this object, a reflection optical system of the present invention comprises a concave reflecting mirror having a positive power for reflecting an incident light beam, and a focused light reflected by the concave reflecting mirror. A convex mirror having negative power to reflect
A reflecting mirror that is arranged on the incident side with respect to this convex reflecting mirror and that reflects the incident light beam to the side, a condensing optical system that condenses the light beam reflected by this reflecting mirror, and a condensing optical system And a light receiving element having a function of observing the position of the focused spot.

Further, the catoptric system of the present invention comprises a first concave reflecting mirror having a positive power for reflecting an incident light beam, and a negative power reflecting a focused light reflected by the first concave reflecting mirror. And a second concave reflector having a positive power, which is arranged on the incident side with respect to the convex reflector and has a positive power to reflect the incident light beam to the side, and a collection of the second concave reflector. It can also be configured by a light receiving element arranged at the light position and having a function of observing the position of the focused spot.

[0012]

As described above, by arranging the reflecting mirror on the incident side with respect to the convex reflecting mirror, light rays absorbed by the convex reflecting mirror can be reduced and deformation of the convex reflecting mirror due to heat can be prevented. In addition, the incident light beam to be shielded by the convex reflecting mirror is reflected laterally and can be used for measuring the position of the object or the celestial body.

[0013]

【Example】

(First Embodiment) As shown in the sectional view of the optical path in FIG. 1, a driving reflecting mirror 3 for changing the direction of an incident light beam 2 from a light emitting object 1.
A concave reflecting mirror 4 having a through hole 41, a convex reflecting mirror 5,
A first projection optical system including a light receiving element 9 for density detection having a spectroscope having a slit arranged on the incident side is provided, and further, a reflecting mirror 6 for reflecting a part of light rays in the lateral direction and the reflection mirror 6. A condenser lens 7 for condensing the light rays reflected by the mirror 6,
A second measuring optical system including a light receiving element 8 for position detection is provided. A bandpass filter for detecting the density in a desired wavelength region may be used instead of the slit arranged in the light receiving element 9 for density detection.

By the first projection optical system, the light-emitting object 1
The light ray 2 incident from is reflected by the driving reflecting mirror 3, and is reflected by the concave reflecting mirror 4 and the convex reflecting mirror 5,
An image is formed on the light receiving element 9 through the through hole 41. At the same time, the second
Part of the incident light reflected by the driving reflecting mirror 3 by the measuring optical system of 1 is laterally reflected by the reflecting mirror 6 arranged in front of the convex reflecting mirror 5, and is condensed by the condenser lens 7. An image is formed on the position detecting light receiving element 8.

At this time, the incident angle of the light beam 2 incident on the reflection optical system can be calculated based on the focal length of the condenser lens 7 and the amount of movement of the center of gravity of the condensed spot on the position detecting light receiving element 8. Further, based on the density distribution obtained from the output signal of the light receiving element 9 for density detection, the light emitting object 1
It is possible to detect the concentration of the component in the atmosphere existing between the driving reflection mirror 3 and the driving reflection mirror 3.

Furthermore, since the light beam at the center of the optical axis in the first projection optical system is used in the second measurement optical system, the optical axes of both optical systems can be made to coincide with each other. Whether the light emitting object 1 is at infinity or at a finite distance, the incident angle in the first projection optical system and the incident angle in the second measurement optical system can be regarded as equal.

Therefore, the incident angle of the incident light beam 2 calculated from the position of the center of gravity of the focused spot on the position detecting light receiving element 8 corresponds to the incident angle in the first projection optical system.

The incident light shielded by the convex reflecting mirror 5 is reflected by the reflecting mirror 6 to the second measuring optical system in front of the convex reflecting mirror 5, so that the incident light is absorbed by the convex reflecting mirror 5. It is possible to reduce the amount of light and prevent the convex reflecting mirror 5 from being deformed by heat.

(Second Embodiment) As shown in the sectional view of the optical path in FIG. 2, a driving reflecting mirror 3 for changing the direction of an incident ray 2 from a light emitting object 1, a concave reflecting mirror 4 having a through hole 41, The convex reflecting mirror 5 and the first projection optical system including the light receiving element 9 are provided, and further, a concave reflecting mirror 10 for reflecting a part of light rays in the lateral direction and having a positive power, and a position detecting mirror. A second measuring optical system including the light receiving element 8 is provided.

As described above, by using the concave reflecting mirror 10 having a positive power, the condenser lens 7 in the first embodiment is eliminated.

By the first projection optical system, the light emitting object 1
Similarly to the first embodiment, the light ray 2 incident from the mirror is reflected by the driving reflecting mirror 3, is reflected by the concave reflecting mirror 4 and the convex reflecting mirror 5, and is imaged on the light receiving element 9 through the through hole 41. It At the same time, the second measurement optical system
A part of the incident light reflected by the driving reflecting mirror 3 is disposed in front of the convex reflecting mirror 5 and has a concave power reflecting mirror 10 having a positive power.
Then, the light is reflected in the lateral direction to form an image on the position detection light receiving element 8.

Then, the incident angle of the light ray 2 incident on the reflection optical system can be calculated based on the focal length of the concave reflecting mirror 10 and the amount of movement of the center of gravity of the focused spot on the position detecting light receiving element 8.

In each of the above embodiments, the light receiving element 9 for density detection is a two-dimensional video camera or CCD.
It can be used as a tracking camera for the light-emitting object 1 by substituting the same.

[0024]

As is apparent from the description based on the above embodiments, according to the reflection optical system of the present invention, the convex surface is formed by arranging the reflecting mirror or the concave reflecting mirror on the incident side. The rays absorbed by the reflecting mirror can be reduced to prevent deformation of the convex reflecting mirror due to heat, and the incident rays that should be shielded by the convex reflecting mirror are reflected sideways to measure the object or astronomical position. Used.

Further, since the light beam at the center of the optical axis in the projection optical system is used in the measurement optical system, the optical axes of both optical systems can be made to coincide with each other, so that the light emitting object is placed at infinity. The incident angle in the projection optical system and the incident angle in the measurement optical system can be regarded as equal regardless of the existence or the finite distance.

Therefore, the incident angle of the incident light beam calculated from the position of the center of gravity of the focused spot on the position detecting light receiving element corresponds to the incident angle in the projection optical system.

[Brief description of drawings]

FIG. 1 is an optical path sectional view showing an embodiment of a reflective optical system of the present invention,

FIG. 2 is an optical path sectional view showing another embodiment of the reflective optical system of the present invention,

FIG. 3 is a sectional view of an optical path showing an example of a conventional reflection optical system,

FIG. 4 is an optical path sectional view showing another example of a conventional reflective optical system,

FIG. 5 is a diagram showing an entrance pupil image in the present invention and a conventional catoptric system.

[Explanation of symbols]

 1 Light-emitting object 2, 21 Incident light beam 3 Driving reflecting mirror 4 Concave reflecting mirror 41 Through hole 5 Convex reflecting mirror 6 Reflecting mirror 7 Condensing lens 8 Position detecting light receiving element 9 Light receiving element 10 Concave reflecting mirror

Claims (4)

[Claims] 1. A concave reflecting mirror having a positive power for reflecting incident light rays, a convex reflecting mirror having a negative power for reflecting focused light reflected by the concave reflecting mirror, and the convex reflecting mirror. A reflecting mirror that is arranged on the incident side and that reflects the incident light beam to the side, a condensing optical system that condenses the light beam reflected by the reflecting mirror, and a condensing position of the condensing optical system A reflective optical system comprising: a light receiving element having a function of observing the position of a spot. 2. The catoptric system according to claim 1, wherein the diameter of the reflecting mirror is smaller than that of the concave reflecting mirror. 3. A first concave reflecting mirror having a positive power for reflecting an incident light beam, a convex reflecting mirror having a negative power for reflecting the focused light reflected by the first concave reflecting mirror, and A second concave reflecting mirror, which is arranged on the incident side with respect to the convex reflecting mirror and has a positive power to reflect the incident light beam to the side, and a light collecting position of the second concave reflecting mirror, A reflective optical system comprising: a light receiving element having a function of observing the position of a spot. 4. The catoptric system according to claim 3, wherein the diameter of the reflecting mirror is smaller than that of the concave reflecting mirror.