JP3069084B2 - Catadioptric system and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro-visual mechanism used in a micro-machine or the like (for example, a CCD camera used in a system which runs in a thin tube and recognizes an environment such as a situation of a wound generated in the tube). The mechanism used in the catadioptric system of (1), in which the deterioration of the image performance of a CCD camera or the like is prevented by flare (stray light) which is likely to occur when a catadioptric optical lens is used. About.

[0002]

2. Description of the Related Art Generally, a catadioptric optical system and a catadioptric optical lens of a micro vision mechanism used in a micromachine or the like have one surface formed as a concave surface as shown in FIG. Optical member 31 formed on a convex surface
(Meniscus lens) is used.

The convex surface of the optical member 31 has a first reflecting surface 3
2 are formed, and the second reflection surface 33 is formed on the concave surface. The remaining surface of the uneven surface where the reflection surface is not formed has the first refraction surface 34 formed on the concave surface side and the second refraction surface 35 formed on the convex surface side.

With such a configuration, the incident light 36 is
The light enters from the first refraction surface 31 and reaches the first reflection surface 32, is reflected by the first reflection surface 32 and the second reflection surface 33, and is emitted from the second refraction surface 35. And this outgoing light 37 is
For example, the light enters a sensor 38 such as a CCD camera. In addition,
The first refraction surface 34 and the second reflection surface 32 and the second refraction surface 33 and the first reflection surface 34 shown in FIG. 13 are formed with the same radius of curvature and aspheric coefficient, respectively.

Since the refraction surfaces 34, 35 and the reflection surfaces 32, 33 can be formed as spherical surfaces,
As the optical member, polished glass or the like can be used, and the entire length can be reduced. In particular, since the positional accuracy between the reflecting surfaces can be adjusted with the eccentricity of the spherical lens (about 2 seconds in transmission declination), the reflecting surfaces 32, 3
3 is often used because it has the advantage of less deterioration of the image due to the displacement.

[0006]

However, in the above-described catadioptric optical lens, when light passes through the second refraction surface 35, light off the optical axis is cut off at the edge of the second reflection surface 33. Sisters. Here, the light is reflected and becomes a stray light (flare) component, which lowers the contrast of the image.

As described above, when stray light is generated in the catadioptric micro-optical lens, white background noise appears in a captured camera image as shown in FIG.

In particular, in the field of development of micromachines and endoscopes, the technology of visual mechanisms using several microlenses having a diameter on the order of several mm has been carried out.
When a catadioptric optical lens with a diameter of φ3 mm is used, the possibility of observing a flaw of about 20 μm 10 mm ahead of the catadioptric optical lens is pursued. Stray light due to multiple reflections in the optical lens is the biggest obstacle.

The present invention has been made based on these circumstances, and has as its object to provide a catadioptric optical system using a catadioptric optical lens which is not affected by stray light components.

[0010]

According to the first aspect of the present invention, one surface is formed as a concave surface, the other side is formed as a convex surface, and the convex surface on these concave and convex surfaces is formed with a convex surface. 1 reflection surface is formed, a second reflection surface is formed on the concave surface, while a first refraction surface is formed on the concave surface side on the other surface where the reflection surface is not formed; A catadioptric optical lens having a second refraction surface formed on the convex surface side, a minute light shielding body provided at a distance on the optical axis on the concave surface side of the catadioptric optical lens; In a catadioptric optical system having a light-shielding cylinder provided in close contact with an outer diameter portion of the lens, the catadioptric optical lens includes a first refracting surface and a second refracting surface.
When the reflecting surface and the first reflecting surface and the second refracting surface are each commonly formed by one aspherical surface, the power of the first refracting surface is -Φ ₁ , and the power of the second refracting surface is + Φ ₂ . when the power of each reflection surface, the first reflecting surface [Phi ₃ is + 6Fai is _2, the second reflecting surface [Phi ₄ relationship -6Fai ₂ is established. However, .phi.2> is .phi.1, and the refractive index when the Ng using synthetic quartz glass, upon the refractive index of the surroundings _{Na, Φ 1 = (Ng-} Na) / R 1 = 0.5 / R ₁ , Φ ₂
= 2Ng / R ₂ = 3 / R ₂ , Φ ₃ = 2Ng / R ₁ = 3 /
R ₁ and Φ ₄ = (Na−Ng) / R ₂ = −0.5 /
R ₂ . A catadioptric optical system characterized in that:

According to the second aspect of the present invention, the light-shielding member is embedded in a hole at the center of the transparent disk, and the transparent disk is fixed to the light-shielding member cylinder so that the reflection of the light-shielding member is achieved. A catadioptric optical system is supported on the optical axis of a refractive optical lens.

According to the third aspect of the present invention,
The light-shielding body is formed by laminating a plurality of thin transparent light-shielding bodies having a light-shielded central portion, and is supported on the optical axis of the catadioptric optical lens by being fixed to the light-shielding body cylinder. Is a catadioptric optical system.

According to the fourth aspect of the present invention,
The light-shielding body is formed by providing a micro column having at least a tip portion that is black-treated in a protruding shape on the optical axis from the center of the lens, and supported on the optical axis of the catadioptric optical lens. It is a catadioptric optical system.

[0014] According to the means of claim 5,
The light shield is formed by inserting and fixing a transparent structure having a light shield at the tip from the front of the light shield cylinder, and being fixed to the light shield cylinder, the optical axis of the catadioptric optical lens. A catadioptric optical system characterized by being supported above.

According to the means of the invention of claim 6,
One surface is formed as a concave surface, and the opposite side is formed as a convex surface, and a first reflective surface is formed on the convex surface of the catadioptric lens on these uneven surfaces, and a second reflective surface is formed on the concave surface. A second refraction surface is formed on the concave surface side, and a second refraction surface is formed on the convex surface side on the other surface where the reflection surface is not formed. In the catadioptric optical lens, the first refractive surface and the second reflective surface, and the first reflective surface and the second refractive surface are each one.
When the power of the first refraction surface is -Φ ₁ and the power of the second refraction surface is + Φ ₂ , the power of each reflection surface is equal to the first reflection surface. Φ ₃ is +
A 6Fai _2, the second reflecting surface [Phi ₄ is the relationship -6Φ _2, Φ
2> Φ1, and when Ng is the refractive index when using synthetic quartz glass and Na is the surrounding refractive index, Φ ₁ =
(Ng-Na) / R ₁ = 0.5 / R ₁ , Φ ₂ = 2Ng /
A catadioptric optical lens that satisfies the conditions of R ₂ = 3 / R ₂ , Φ ₃ = ₂ Ng / R ₁ = 3 / R ₁ and Φ ₄ = (Na−Ng) / R ₂ = −0.5 / R ₂ A lens fixing step of closely fixing the inner surface to the inner diameter of the black light-shielding body cylinder, and a light-shielding body fixing step of fixing the light-shielding body separately on the concave optical axis of the catadioptric lens. This is a method for manufacturing a catadioptric optical system.

Further, according to the means of the invention of claim 7,
The light shielding body fixing step is a method for manufacturing a catadioptric optical system, wherein the light shielding body is provided on a structure supported by the light shielding body cylinder.

Further, according to the means of the present invention,
7. The method of manufacturing a catadioptric optical system according to claim 6, wherein the light-shielding body fixing step includes providing the light-shielding body on a structure supported by the catadioptric optical lens.

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a structural view of a catadioptric optical lens 1 which is a lens used in a catadioptric optical system.

The catadioptric optical lens 1 uses a meniscus lens (optical member) 2 having one surface formed as a concave surface and the other surface formed as a convex surface.

A first reflecting surface 3 is formed on the convex surface of the optical member 2, and a second reflecting surface 4 is formed on the concave surface. A first refraction surface 5 is formed on the concave side and a second refraction surface 6 is formed on the convex side on the remaining surface of the uneven surface where the reflection surface is not formed.

Here, when the first refraction surface 5 and the second reflection surface 4 and the first reflection surface 3 and the second refraction surface 6 are commonly formed by one aspherical surface, respectively, the first refraction surface is formed. Assuming that the power of No. 5 is −Φ ₁ and the power of the second refraction surface 6 is + Φ ₂ , the power of each surface is represented as shown in FIG. That is, the first refractive surface: - [Phi] ₁ first reflecting surface: + 6Φ ₂ second reflecting surface: -6Fai ₂ second refractive surface: + [Phi ₂ become.

Where Φ ₁ = (Ng−Na) / R ₁ = 0.5 / R ₁ (1) Φ ₂ = ₂ Ng / R ₂ = 3 / R ₂ (2) Φ ₃ = 2 Ng / R ₁ = 3 / R ₁ (3) Φ ₄ = (Na-Ng) / R ₂ = −0.5 / R ₂ (4) Ng is a refractive index (for example, 1.5 or less) when synthetic quartz glass is used as the optical member.
Is the surrounding refractive index (for example, 1.0 or less).

Since it is necessary to have the power of the convex lens as a whole, the power Φ of the entire catadioptric optical lens 1 is Φ = 7 (Φ ₂ − Φ ₁ ) = 6 (Φ ₂ −Φ ₁ ) + (Φ ₂ −Φ ₁ ) (5) As can be seen from the expression (5) representing this power Φ, Φ ₂ > Φ ₁ as a convex lens action for imaging. The condition of (6) is required.

As shown in FIG. 3, the catadioptric optical system according to the embodiment of the present invention is arranged such that the catadioptric optical lens 1 and the optical system are arranged in front of the catadioptric optical lens 1 shown in FIG. A light-shielding cylinder 7a whose inner surface is blackened so as to attenuate the reflected light of the light so as to be in contact with the outer diameter of the catadioptric optical lens 1 concentrically with respect to the axis, and A light-shielding cylinder 7b whose inner surface is painted black is arranged concentrically with the catadioptric optical lens 1 so as to be in contact with the outer diameter of the catadioptric optical lens 1.

In addition, a black cylindrical light shield 8 is disposed in front of the catadioptric optical lens 1 on the optical axis. Further, a black coating process is performed on the side surface portion and the vicinity of the side surface portion of the catadioptric optical lens 1. The light-shielding cylinder 7a and the light-shielding cylinder 7b need not be separately provided, and the light-shielding cylinder 7 formed integrally may be used. In this case, since the side wall of the catadioptric optical lens 1 is also in contact with the light-shielding body cylinder 7 whose inner surface is painted black, the catadioptric optical lens 1 itself does not need to be blackened.

Flares to be noted when using the catadioptric optical lens 1 can be roughly classified into light passing through between the reflecting surfaces of the catadioptric optical lens 1 and passing through the lens surface, and inside the catadioptric optical lens 1. Since there are two types of multi-reflected light generated by multi-reflection, it is necessary to take measures to prevent the light of both flares from being incident on the CCD element.

First, the principle of the reduction of the passing light (flare) will be described with reference to FIG.
This is achieved by shading the light with the light-shielding cylinder 7. The length of the light-shielding cylinder 7 for shading is adjusted to an appropriate length, and the light passing through the catadioptric lens 1 is reduced. 9
Prevention. That is, the catadioptric optical lens 1
The object is placed at a position 10 mm away from the optical axis of the concave surface, and the length of the light-shielding cylinder 7 (7a) extending rearward on the optical axis from the position of the concave surface of the catadioptric lens 1 on the optical axis. To
As a result of confirming by changing to 5 mm, 4 mm and 3 mm respectively, assuming that the flare amount of the through light 9 when the tube length is 5 mm (flare amount = background noise / signal) is a reference value, Is 9 times as large as the reference value when the cylinder length is 4 mm, and the cylinder length is 3 mm.
In this case, the passing light 9 was 2.8 times the reference value.

The reason why the side surface of the catadioptric optical lens 1 is painted black is to prevent external light from entering from the side surface of the lens. A light-shielding cylinder 7b whose inner surface is blackened so as to be in contact with the outer diameter of the catadioptric optical lens 1 concentrically with respect to the optical axis.
The reason for disposing is to prevent external light from directly entering the CCD.

Next, the reduction of multiple reflected light in the catadioptric optical lens 1 will be described with reference to FIG. 5. A light-shielding body, which is a minute columnar object on the optical axis of the catadioptric optical lens 1, is described. 8 is installed to cut light incident on the catadioptric optical lens 1 at a wide angle, so that multiple reflected light 10 that is multi-reflected beyond the specification limit in the catadioptric optical lens 1
The occurrence of is prevented. While the light shield 8 cuts the light incident at a wide angle, the light from the object must not prevent the light from entering the catadioptric lens 1. Therefore, the size and the installation position on the optical axis should be carefully considered. Need to be placed. For example, when an object of 1 mm is set at a position 10 mm forward on the optical axis of the reflection surface of the catadioptric lens 1,
The diameter of the cylindrical light shield is φ0.28 mm and the length is
0.5 mm.

Regarding this, the following three cases were confirmed by experiments. (A) When the light-shielding cylinder 8a is not provided and the light-shielding body 8 is not arranged on the optical axis, (b) When the light-shielding cylinder 7a has a cylinder length of 5 mm and the light-shielding body 8 is not arranged on the optical axis,
(C) A case where the light-shielding body cylinder 7a has a cylinder length of 5 mm and the light-shielding body 8 is arranged on the optical axis. As a result, it was confirmed that the flare was smallest in the case of (c). In particular, the flare at the outline of the image was greatly reduced.

Next, various arranging means for arranging the minute light shield 8 at a predetermined position on the optical axis at the rear will be described with reference to the drawings.

The means shown in FIG.
In FIG. 6A, an annular step 11 is provided for installing the catadioptric optical lens 1 and the light shielding body 8 as a minute columnar object, and the step 11 has three thin supporting members as shown in FIG. Beam 12
After inserting the annular body 13 in which the minute light-shielding body 8 is supported at the center, the sleeve 11a is inserted into the annular body 13 to fix the annular body 13. The sleeve 11a has the same inner diameter as the small diameter portion of the step portion, the same outer diameter as the large diameter portion, and has its inner surface subjected to black coating. That is, the annular body 13 has a structure similar to that in which an annular groove is provided on the inner wall side of the light-shielding body cylinder 7a and inserted and fixed in the groove. Therefore, it is possible to arbitrarily select a structure that can achieve the same operation without using the sleeve 11a, for example, separating the light shielding body cylinder 7a at the insertion portion of the annular body 13. FIG. 6C is a cross-sectional view of the ring 13 taken along the line AA ′ in FIG. 6B.

The number of the support beams 12 does not need to be particularly limited to three, but is preferably plural in consideration of the stability of the holding position. In addition, it is sufficient if a stable position can be maintained even with one beam.
It is necessary to avoid an object having an optically adverse effect such as blocking the light from the object due to the thickness of 2 being too large. Also,
As the black body for forming the light shielding body 8, a black rod obtained by cutting a graphite rod or a black rod obtained by cutting a stainless steel round rod is used.

The means shown in FIG.
7A is provided with an annular step 11 for installing the catadioptric optical lens 1 and the minute light shield 8.
As shown in (b), a structure 16 in which a minute light shielding body 8 is embedded is inserted into a hole 15 provided at the center of a transparent body 14 such as a disc-shaped glass or the like, and then fixed with the above-mentioned sleeve 11a. FIG. 7C shows the structure 16 taken along line A- in FIG.
It is sectional drawing of A 'cross section.

The means shown in FIG.
8A is provided with an annular step 11 for installing the catadioptric optical lens 1 and the minute light shield 8.
A structure 18 in which a thin glass plate having a blackened portion 20 having a small area for light shielding is attached to the central portion as shown in FIG.
After the structure 18 is inserted, the above-described sleeve 1 is inserted.
Fix at 1a. FIG. 8C shows the structure 18 shown in FIG.
3 is a cross-sectional view taken along line AA ′ in FIG. . FIG.
As shown in the side view shown in FIG. 3D, a thick glass 19 provided with a blackened portion 20 having a small area for light shielding on both sides can be used.

In the means shown in FIG. 9 (a), a columnar structure 21 having a front end portion of a catadioptric optical lens 1 subjected to black processing is used.
Is provided. The black processing may be performed not only at the tip but also at the entire length of the columnar structure 21 or at any length from the tip. Further, instead of making the columnar structure 21 cantilever from the catadioptric lens 1, as shown in FIG.
Is provided to form a double-sided structure, the position of the distal end of the columnar structure 21 is more stable.

In the means shown in FIG.
A transparent structure 23 having a cylindrical light shield 8 protruding concentrically at the center of one side of a transparent material such as glass, polycarbonate or epoxy as shown in FIG. From the front of the light shielding body cylinder 7a. FIG. 11C is a side view of the transparent structure 23.

In each of the above embodiments, the light shielding member 8 is used.
Although a micro-column is used as the light-emitting element, not only a micro-circle but also a conical shape shown in FIG. 12A, a spherical shape shown in FIG. Various shapes can be arbitrarily selected and used.

With the above-described configuration, the light (scattered) incident on the catadioptric optical lens 1 from other than the object light is transmitted to the light-shielding body cylinder 7 disposed in front and rear of the catadioptric optical lens 1 and to the front of the catadioptric optical lens 1. The stray light can be geometrically removed by the arranged light shield 8.

The light-shielding cylinder 7a in front of the catadioptric optical lens 1 mainly prevents light (stray light) that enters the catadioptric optical lens 1 from a point far away from the object to be observed and passes through. Further, the light-shielding body cylinder 7b behind the catadioptric lens 1 functions to remove light (stray light) directly incident on the CCD camera from the outside.

The minute light shield 8 disposed in front of the catadioptric lens 1 is incident on the catadioptric lens 1 at a wide angle (for example, 10.2 degrees), and is light (stray light) that is multiply reflected within the lens. Can be prevented.

In each of the above embodiments, both the reflection and refraction of the incident light are performed by the catadioptric optical lens 1.
Even when only refraction is performed, a light-shielding cylinder is effective as a measure against stray light that passes through the lens. Further, by processing the wedge-shaped groove into the lens, it is possible to prevent flare of the light 9 passing therethrough.

[0049]

According to the present invention, when a catadioptric optical lens is used in a catadioptric optical system, the occurrence of flare due to scattered light other than light emitted from an object can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a catadioptric optical lens used in a catadioptric optical system.

FIG. 2 is an explanatory diagram of the power of each surface of a catadioptric optical lens.

FIG. 3 is a schematic diagram of a catadioptric optical system showing an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a principle of reducing light passing through (flare).

FIG. 5 is an explanatory diagram of a principle of reducing multiple reflection light (flare).

FIG. 6A is an explanatory view of a light-shielding member arranging means showing an example of an embodiment of the present invention, FIG. 6B is a front view showing a light-shielding member support portion, and FIG. 6C shows a light-shielding member support portion. AA in b)
Sectional view of the 'section.

FIG. 7A is an explanatory view of a light-shielding member arranging means showing an example of an embodiment of the present invention, FIG. 7B is a front view showing a light-shielding member support portion, and FIG. AA in b)
Sectional view of the 'section.

8A is an explanatory view of a light-shielding member arranging means showing an example of an embodiment of the present invention, FIG. 8B is a front view showing a light-shielding member support portion, and FIG. 8C is a light-shielding member support portion. AA in b)
Sectional view of the 'section. (D) The side view which shows the example of a support part modification of a light shielding body.

FIG. 9A is an explanatory view of a light-shielding member arranging means showing an example of an embodiment of the present invention, and FIG. 9B is a perspective view showing a support part of the light-shielding member.

FIG. 10 is a side view showing a modification of the supporting portion of the light shielding body.

11A is an explanatory view of a light-shielding member arranging means showing an example of an embodiment of the present invention, FIG. 11B is a front view showing a light-shielding member support portion, and FIG. 11C is a side view showing a light-shielding member support portion. FIG.

12A is a perspective view of a modified example of the light shielding body, and FIG. 12B is a perspective view of another modified example of the light shielding body.

FIG. 13 is a schematic diagram of a conventional catadioptric optical system.

FIG. 14 is an explanatory diagram of background noise.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... catadioptric optical lens, 3 ... 1st reflection surface, 4 ... 2nd reflection surface, 5 ... 1st refraction surface, 6 ... 2nd refraction surface, 7, 7a, 7
b: light shielding cylinder, 8: light shielding, 9: light passing through, 10: multiple reflection light,

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiichiro Murai 33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa Pref. Toshiba Corporation (56) References JP-A-9-68604 (JP, A) JP-A-8-122641 (JP, A) JP-A-6-214154 (JP, A) JP-A-10-206986 (JP, A) JP-A-63-141013 (JP, A) JP-A-10-39218 (JP , A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 9/00-17/08 G02B 21/02-21/04 G02B 25/00-25/04

Claims (8)

(57) [Claims] 1. One surface is formed as a concave surface, the opposite side is formed as a convex surface, and a first reflective surface is formed on the convex surface on these uneven surfaces, and a second reflective surface is formed on the concave surface. A reflection surface is formed, while the other surface where the reflection surface is not formed has a first refraction surface formed on the concave surface side and a second refraction surface formed on the convex surface side. A refractive optical lens, a minute light shield provided at a spaced position on the concave-side optical axis of the catadioptric optical lens, and a light shield provided in close contact with an outer diameter portion of the catadioptric optical lens In a catadioptric optical system having a cylinder, the catadioptric lens has a first refracting surface and a second reflecting surface.
Surface, and the first reflecting surface and the second refracting surface are each aspheric.
In the case of a common surface type, the power of the first refraction surface
Is -Φ ₁ , and the power of the second refraction surface is + Φ ₂ ,
Power of each reflection surface, the first reflecting surface [Phi ₃ is + 6Φ ₂ der
Therefore , when the second reflecting surface Φ ₄ satisfies the relationship of −6 Φ ₂ , where Φ ₂ > Φ 1 and Ng is the refractive index when using synthetic quartz glass, and Na is the surrounding refractive index. , Φ ₁ = (Ng−Na) / R ₁ = 0.5 / R ₁ , Φ ₂
= 2Ng / R ₂ = 3 / R ₂ , Φ ₃ = 2Ng / R ₁ = 3 /
R ₁ and Φ ₄ = (Na−Ng) / R ₂ = −0.5 /
R ₂ . A catadioptric optical system characterized in that: 2. The light-shielding body has a hole at the center of a transparent disk.
This transparent disk is embedded in the light shield cylinder
The optical axis of the catadioptric lens
2. The reflection bending member according to claim 1, wherein the reflection bending member is supported.
Folding optical system. 3. The light-shielding body has a light- transmitting thin film whose central part is shielded from light.
A plurality of light-shielding members are formed by superposing a plurality of light-shielding members,
The catadioptric optical lens is fixed to the cylinder.
2. The device according to claim 1, which is supported on an optical axis.
Catadioptric system. 4. The light-shielding body has a black end at least.
The processed micro cylinder is projected on the optical axis from the center of the lens
Provided on the optical axis of the catadioptric lens.
2. The catadioptric according to claim 1, wherein
Optical system. 5. The light-shielding body has a light-shielding body at a tip portion.
Transparent structure is inserted and fixed from the front of the light shield cylinder
Is fixed to the light-shielding body cylinder,
It is supported on the optical axis of the refraction optical lens
2. The catadioptric optical system according to claim 1, wherein: 6. One surface is formed as a concave surface, and the opposite surface is formed.
Side is formed as a convex surface, and the above-mentioned counter surface on these uneven surfaces is formed.
A first reflecting surface is formed on the convex surface of the projection lens,
A second reflecting surface is formed on the concave surface, while a second reflecting surface is formed on the concave surface;
On the remaining surface where the projection surface is not formed, the concave surface side
To form a first refraction surface, and on the convex surface side
The catadioptric optical lens having the second refraction surface formed thereon is
The first refraction surface and the second reflection surface, and the first reflection surface and the second refraction
When the surfaces are commonly formed by one aspheric surface
In this case, the power of the first refracting surface is -Φ ₁ and the power of the second refracting surface is
In the case where the word + [Phi ₂ and, the power of the reflecting surfaces, the first
Reflecting surface [Phi ₃ is + 6Fai is _2, the second reflecting surface [Phi ₄ is -6Φ
₂ is Φ2> Φ1 and Ng is synthetic quartz
The refractive index when glass is used, and Na is the refractive index around
Φ ₁ = (Ng−Na) / R ₁ = 0.5 / R ₁ ,
Φ ₂ = 2Ng / R ₂ = 3 / R ₂ , Φ ₃ = 2Ng / R ₁ =
3 / R ₁ and Φ ₄ = (Na-Ng) / R ₂ = -0.
The inner surface of the catadioptric optical lens that is satisfied under the condition of 5 / R ₂
Lens fixing process to fix tightly to the inner diameter of the black light shielding cylinder
A distance on the optical axis on the concave side of the catadioptric optical lens.
And a light-shielding body fixing step of fixing the light-shielding body by
A method of manufacturing a catadioptric optical system. 7. The light-shielding body fixing step, wherein the light-shielding body cylinder is provided.
That the light-shielding body is provided on a structure supported by
7. The method of manufacturing a catadioptric optical system according to claim 6, wherein
Law. 8. The light-shielding body fixing step includes the step of:
The light-shielding body is provided on a structure supported by a scientific lens.
The catadioptric optical system according to claim 6,
Production method.