JPH08166542A - Catadioptric system and optical device using the same - Google Patents

Abstract

PURPOSE: To reduce the production cost by decreasing the number of parts of a catadioptric system used for binoculars, etc., and facilitating assembling and adjusting work. CONSTITUTION: Optical members 2 and 3 are arranged to be opposed to each other on an optical axis 1, and constitute the objective lens of the binoculars. Reflection layers 21 and 31 are formed at the parts of transparent bodies 20 and 30 in the optical members 2 and 3. Lens parts 23 and 33 and reflection parts 24 and 34 are formed to be planar and semicircular on the transparent bodies 20 and 30, and the lens parts 23 and 33 are opposed in reverse attitude so as to be opposed to the reflection parts 24 and 34. Light transmitted through the lens part 23 passes the reflection parts 34 and 24 and the lens part 33, and reaches an eye point through an ocular 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catadioptric optical system and an optical device using the same, and is particularly suitable as an objective lens for a telescope or binoculars configured to obtain an erect image using a reflecting mirror. Regarding the configuration of an optical system.

[0002]

2. Description of the Related Art Conventionally, in an afocal optical system used for binoculars or the like, it is necessary to invert an image in order to obtain an erect image, and normally an erect image is obtained by folding a light path using a reflecting prism. ing. It has been attempted to use a mirror instead of a prism, but various optical aberrations are large and few have realized it. However, Japanese Patent Publication No. 6-501569 discloses a reflection type optical system which has an optical path folded back by a pair of erecting mirrors, and the erecting mirror and the lens group each have a semi-circular optical aperture. Is proposed. According to this optical system, a compact optical system that suppresses various aberrations can be configured.

[0003]

However, in the above-mentioned conventional catadioptric optical system, it is necessary to accurately incorporate a pair of mirrors and a plurality of lenses for obtaining an erect image, which results in an increase in the number of parts and assembly. -There was a problem that the manufacturing cost increased due to the complicated adjustment work. Therefore, the present invention solves the above problems, and the problem is to realize the above-mentioned reflective optical system with high symmetry and a simple structure to reduce the number of parts and reduce the manufacturing cost. To do.

[0004]

In order to solve the above-mentioned problems, a catadioptric optical system according to the present invention has a reflecting surface formed on a part of a translucent member and another one of the translucent members. A pair of optical members each having a lens portion formed on the lens portion, the lens portion formed on one of the pair of optical members, the reflection surface formed on the other, the reflection surface formed on one side. ,
The lens portions formed on the other side are arranged so as to face each other so that the optical path passes therethrough.

Here, it is preferable that the pair of optical members are formed in the same shape with the same reflecting surface and the same lens portion.

Further, it is preferable that the reflecting surface of the optical member and one refracting surface of the lens portion are formed on a single curved surface.

In this case, it is desirable that the reflecting surface and the refracting surface have the same curvature.

Further, it is preferable that the translucent member is formed by resin molding.

An optical device using these catadioptric optical systems as an objective lens is constructed.

[0010]

According to the first aspect, a pair of optical members integrally provided with the reflecting portion and the lens portion are arranged so that an erect image can be obtained by both reflecting portions and desired optical characteristics can be obtained by both lens portions. Since it is configured so as to obtain the optical accuracy, it is possible to reduce the number of parts and simplify the assembling / adjusting work while ensuring the optical accuracy, and it is possible to reduce the manufacturing cost.

According to the second aspect, since the pair of optical members are formed in the same shape, the number of parts can be further reduced and the manufacturing cost can be reduced.

According to the third aspect, since the reflecting surface of the optical member and the one refracting surface of the lens portion are formed on a single curved surface, the optical member can be easily manufactured.

According to the fourth aspect, the optical member can be formed more easily by forming the reflecting surface and the one refracting surface formed on a single curved surface with the same curvature. it can.

According to the fifth aspect, since the translucent member is formed by resin molding, it is possible to easily realize a composite shape of the reflecting surface and the lens portion, so that mass production can be achieved at low cost.

According to the sixth aspect, by constructing an optical device using the catadioptric optical system as an objective lens, it is possible to realize an optical device which is inexpensive and can be downsized and which can obtain an erect image.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the structure of an embodiment according to the present invention will be described with reference to the drawings. In this embodiment, as shown in FIG. 1, a pair of optical members 2 and 3 are arranged to face each other on an optical axis 1 to form an objective lens, and an eyepiece lens 4 is arranged behind the objective lens. Inside the optical members 2 and 3, baffle plates 5 and 6 for light shielding are arranged, respectively.

The optical members 2 and 3 are made of acrylic resin by injection molding and are integrally formed into a transparent body 20 and 30 having a plane circular shape, and a reflective layer 21 formed on the surface of the transparent body 20 and 30. , 31 and. Transparent body 20, 30
Has lens portions 23 and 33 and reflecting portions 24 and 34, respectively, which are semicircular in a plane, and the reflecting layers 21 and 31 are formed on the convex surfaces of the reflecting portions 24 and 34. Reflective layers 21, 31
Is formed in a region B in the drawing, and is composed of a metal reflection film such as aluminum formed by vapor deposition or plating, and a protective film formed on the surface of the reflection film.

Acrylic resin (PMMA) is most preferable as the material of the transparent bodies 20 and 30 in that it is easy to manufacture and has good optical characteristics, but resins other than acrylic, such as polystyrene, may be used, and various materials are also usable. It may be formed of glass. The reflective layers 21 and 31 may be metal layers or resin layers formed by various known methods other than the above. The baffle plates 5 and 6 are made of a material that is difficult to transmit at least visible light.

In the above optical system, the optical members 2 and 3 are formed in the completely same shape so as to take the inverted posture with respect to the optical axis 1 with a certain interval therebetween (the lens portion of the optical member 2). 23 is disposed so as to face the reflecting portion 34 of the optical member 3 and the reflecting portion 24 of the optical member 2 faces the lens portion 33 of the optical member 3). In addition, the lens units 23 and 33
The boundary surface between the reflectors 24 and 34 is located on the optical axis 1. Light entering from the area A in the figure of the optical member 2 passes through the lens portion 23 and enters the reflecting portion 34,
The light is reflected by the reflective layer 31 and reaches the reflective portion 24. The light that has entered the reflecting portion 24 is reflected by the reflecting layer 21 and is reflected by the lens portion 33.
After being incident on and refracted, the light is converged by the eyepiece lens 4 and reaches the eye point. Here, the dotted line C in the figure indicates the optical path of the light emitted from the object point.

The baffle plate 5 blocks the light leaking from the lens parts 23 and 33 to the reflecting parts 24 and 34, and the baffle plate 6 blocks the light leaking directly from the lens part 23 to the lens part 33. The baffle plates 6 and 6 are 2 in the figure.
As shown by the chain line D, the lens portion 23 to the lens portion 33
It is configured to limit the light directly incident on the outside of the focusing range of the eyepiece lens 4. The light-shielding range of the baffle plate 6 is designed so as to minimize the light-shielding according to the presence of an aperture stop or the like.

Lens parts 23 and 33 and reflecting parts 24 and 34
Of the refracting surface and the reflecting surface of S1, S2, S3, S4, S5, S6, S7, S8, S respectively along the optical path.
9, S10, and these curvatures are R1, R2, R3,
If R4, R5, R6, R7, R8, R9, and R10, the thickness of the center point of the optical member 2 is t2, and the thickness of the center point of the optical member 3 is t3, then R1 = -R10, R2 = -R9. ，
R3 = R5 = -R6 = -R8, R4 = -R7, t2 = t
3 is established. By doing so, the optical members 2 and 3 can be formed into completely identical parts, so that the number of parts can be reduced and the manufacturing cost can be reduced.

In this embodiment, in addition to the above conditions,
Furthermore, the lens unit 2 is set with R1 = R7 and R4 = R10.
By making the curvatures of the refracting surfaces 3 and 33 equal to the curvatures of the reflecting surfaces of the reflecting portions 24 and 34, the outer shape of the optical members 2 and 3 is a single curved surface and is formed with the same curvature. As a result, the molding itself becomes easy, and it is not necessary to align the molding dies for molding the optical member, so that the mold for the molding is easily manufactured. Moreover, when the optical system is incorporated in the apparatus, Since it is not necessary to form a step on the lens receiving frame that fixes the optical members 2 and 3, the manufacturing cost can be further reduced.

Next, the following tables show examples (design examples 1 to 3) in the case where a plurality of types of optical designs are made based on the above embodiment. In each table, CR is the radius of curvature of the refracting surface or the reflecting surface (the reference sign is based on the direction from the object point to the image point), R is the opening radius, and T is the distance between the refracting surface or the reflecting surface (the reference sign is Based on the direction from the object point to the image point), N1 is the refractive index for the light of wavelength 587.56 nm, N2 is the refractive index for the light of wavelength 435.84 nm,
N3 is a refractive index for light of 656.28 nm. Note that S11 and S12 represent the two refracting surfaces of the eyepiece lens 4. Further, the aspherical surfaces of the refracting surface and the reflecting surface are represented by the following expressions, and the shape of the aspherical surface is defined by the coefficient therein. Here, X represents a coordinate along the optical axis, and Y represents a height (distance) from the optical axis.

[0024]

[Table 1] (Design example 1) Optical system configuration data CR R T N1 N2 N3 AIR 0.00000 1.00000 1.00000 1.00000 S1 45.00000 18.000 PMMA20 5.00000 1.49091 1.50158 1.48838 S2 500.00000 18.000 AIR 46.50000 1.00000 1.00000 1.00000 S3 -31.00000 18.000 PMMA20 2.00000 1.49091 1.50158 1.48 1.48158 1.48 -45.00000 18.000 -PMMA20 -2.00000 -1.49091 -1.50158 -1.48838 S5 -31.00000 18.000 -AIR -49.50000 -1.00000 -1.00000 -1.00000 S6 31.00000 18.000 -PMMA20 -2.00000 -1.49091 -1.50158 -1.48838 S7 45.00000 18.000 PMMA20 2.00000 1.49091 1.50158 1.48838 S8 18.000 AIR 46.50000 1.00000 1.00000 1.00000 S9 -500.00000 18.000 PMMA20 5.00000 1.49091 1.50158 1.48838 S10 -45.00000 18.000 AIR 56.55243 1.00000 1.00000 1.00000 S11 9.58300 10.000 PMMA20 8.00000 1.49091 1.50158 1.48838 S12 -23.05700 10.000 AIR 10.00000 1.00000 1.00000 1.00000 Non-refractive surface or reflective surface S1 ε = 0.75 S4 ε = 0.75 S7 ε = 0.75 S10 ε = 0.75 S11 ε = -0.3077800 A4 = 0.921225 × 10 ^-5 A6 = -0.30 × 10 ^-7 S12 ε = -10.1195

[0025]

[Table 2] (Design Example 2) Optical system configuration data CRRT N1 N2 N3 AIR 0.00000 1.00000 1.00000 1.00000 S1 45.00000 18.000 PMMA20 5.00000 1.49091 1.50158 1.48838 S2 165.00000 18.000 AIR 47.00000 1.00000 1.00000 1.00000 S3 -33.00000 18.000 PMMA20 2.00000 1.49091 1.50158 1.48 -45.00000 18.000 -PMMA20 -2.00000 -1.49091 -1.50158 -1.48838 S5 -33.00000 18.000 -AIR -50.00000 -1.00000 -1.00000 -1.00000 S6 33.00000 18.000 -PMMA20 -2.00000 -1.49091 -1.50158 -1.48838 S7 45.00000 18.000 PMMA20 2.00000 1.49091 1.50158 1.48838 S8 18.000 AIR 47.00000 1.00000 1.00000 1.00000 S9 -165.00000 18.000 PMMA20 5.00000 1.49091 1.50158 1.48838 S10 -45.00000 18.000 AIR 55.13685 1.00000 1.00000 1.00000 S11 9.58300 10.000 PMMA20 8.00000 1.49091 1.50158 1.48838 S12 -23.05700 10.000 AIR 10.00000 1.00000 1.00000 1.00000 non-spherical surface or reflective surface S1 ε = 0.75 S4 ε = 0.75 S7 ε = 0.75 S10 ε = 0.75 S11 ε = -0.3077800 A4 = 0.921225 × 10 ^-5 A6 = -0.30 × 10 ^-7 S12 ε = -10.1195

[0026]

[Table 3] (Design Example 3) Optical system configuration data CR R T N1 N2 N3 AIR 0.00000 1.00000 1.00000 1.00000 S1 60.00000 22.000 PMMA20 5.00000 1.49091 1.50158 1.48838 S2 183.50000 22.000 AIR 69.00000 1.00000 1.00000 1.00000 S3 -43.00000 22.000 PMMA20 3.00000 1.49091 1.50 -60.00000 22.000 -PMMA20 -3.00000 -1.49091 -1.50158 -1.48838 S5 -43.00000 22.000 -AIR -71.00000 -1.00000 -1.00000 -1.00000 S6 43.00000 22.000 -PMMA20 -3.00000 -1.49091 -1.50158 -1.48838 S7 60.00000 22.000 PMMA20 3.00000 1.49091 1.50158158. 22.000 AIR 69.00000 1.00000 1.00000 1.00000 S9 -183.00000 22.000 PMMA20 5.00000 1.49091 1.50158 1.48838 S10 -60.00000 22.000 AIR 54.18900 1.00000 1.00000 1.00000 S11 11.21800 13.000 PMMA20 11.00000 1.49091 1.50158 1.48838 S12 -28.18700 13.000 AIR 13.00000 1.00000 1.00000 1.00000 1.00000 1.00000 1.00000 S1 ε = 0.845 S4 ε = 0.845 S7 ε = 0.845 S10 ε = 0.845 S11 ε = -0.1000000 A4 = 0.150000 × 10 ^-4 A6 = -0.45 × 10 ^-7 S12 ε = -22.300 0

In each of the above-mentioned design examples 1, 2, and 3, the magnification value of the optical system is 6 × 50 times, and the Seidel's 5 aberrations can be kept within a predetermined range necessary for use in small binoculars. Have been successful. In this embodiment, the pair of optical members 2 and 3 constitute two reflecting surfaces and two lens portions, so that the number of parts can be reduced and assembly / adjustment can be facilitated to reduce the manufacturing cost. However, as described above, the same effect and high symmetry of the optical members 2 and 3 have a great effect.
The premise of this effect is that the above configuration can be reliably realized while maintaining the conventional optical performance as demonstrated by the above design example. The pair of optical members of the above embodiment,
It can be used as various objective lenses mounted on camera lenses, panoramic projectors, surveillance sensors, game machines and the like.

As described above, in each of the above-mentioned embodiments, the number of parts constituting the optical system can be reduced and the labor for assembling and adjusting is not required, so that the manufacturing cost can be reduced.
In particular, since parts having a small number of points can be manufactured by molding a synthetic resin, mass production is possible and a lightweight structure can be achieved. Furthermore, since the number of parts is reduced, the parts are integrally formed, and the assembly and adjustment are easy, the optical system can be configured with high accuracy and the durability of the optical system is improved.

[0029]

As described above, the present invention has the following effects. According to the first aspect, a pair of optical members integrally provided with the reflecting portion and the lens portion are arranged so that an erect image can be obtained by both reflecting portions and desired optical characteristics can be obtained by both lens portions. Since it is configured, it is possible to reduce the number of parts and simplify the assembling / adjusting work while ensuring the optical accuracy, and it is possible to reduce the manufacturing cost.

According to the second aspect, since the pair of optical members are formed in the same shape, the number of parts can be further reduced and the manufacturing cost can be reduced.

According to the third aspect, since the reflecting surface of the optical member and one refracting surface of the lens portion are formed on a single curved surface, the optical member can be easily manufactured.

According to the fourth aspect, the optical member can be formed more easily by forming the reflecting surface and the one refracting surface formed on a single curved surface with the same curvature. it can.

According to the fifth aspect, since the translucent member is formed by resin molding, it is possible to easily realize a composite shape of the reflecting surface and the lens portion, so that mass production can be achieved at low cost.

According to a sixth aspect of the present invention, by constructing an optical device using the catadioptric optical system as an objective lens, it is possible to realize an optical device which has few aberrations, can be miniaturized, and can obtain an erect image. .

[Brief description of drawings]

FIG. 1 is a configuration diagram of an optical system showing a configuration of a first embodiment according to the present invention.

[Explanation of symbols]

 1 Optical Axis 2,3 Optical Member 4 Eyepiece 5,6 Baffle Plate 20,30 Transparent Body 21,31 Reflective Layer 23,33 Lens Part 24,34 Reflector

Claims (6)

[Claims] 1. A pair of optical members, each of which includes a reflecting surface formed on a part of the translucent member and a lens portion formed on another part of the translucent member. The lens portion formed on one side of the optical member, the reflection surface formed on the other side, the reflection surface formed on one side, and the lens portion formed on the other side are arranged so as to face each other so that the optical path passes therethrough. A catadioptric optical system characterized by the above. 2. The catadioptric optical system according to claim 1, wherein the pair of optical members are formed in the same shape with the same reflecting surface and the same lens portion. 3. The catadioptric optical system according to claim 1, wherein the reflecting surface of the optical member and one refracting surface of the lens portion are formed on a single curved surface. 4. The catadioptric optical system according to claim 3, wherein the reflecting surface and the refracting surface have the same curvature. 5. The catadioptric optical system according to claim 1, wherein the translucent member is formed by resin molding. 6. An optical device using the catadioptric optical system according to any one of claims 1 to 5 as an objective lens.