JP3458013B2 - Binocular eyepieces - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eyepiece lens for binocular vision used for binocular vision or stereoscopic vision with binoculars or a microscope.

[0002]

2. Description of the Related Art When performing binocular vision or stereoscopic vision with binoculars or a microscope, fatigue during observation is reduced so that stereoscopic observation can be easily performed. Furthermore, Japanese Patent Publication Sho 5
The eyepiece disclosed in Japanese Patent Laid-Open No. 0-19936 has a large exit pupil diameter, eliminates the need for adjustment of the interpupillary distance, and avoids the disappearance of the image due to camera shake or head shake. However, in this optical system, as shown in FIG. 8, since the eyepiece lens is composed of one lens common to the left and right, it is difficult to increase the magnification. Therefore, the magnification of the objective lens must be increased, optical design is difficult, and it is necessary to process the lens parts and the like with high accuracy.

In addition, a binocular eyepiece which is composed of two commonly used eyepieces can have a high magnification but has a large exit pupil diameter, so that the eyepiece becomes large in size and is easy for an observer to observe. It is difficult to add congestion to do so.

[0004]

According to the present invention, the diameter of the pupil is 8
An eyepiece lens having a magnification of 5 times or more in mm or more and easy to observe with vergence is provided.

[0005]

The eyepiece of the present invention comprises:
The exit-eye diameter is 8 mm or more, the eye lens closest to the eye is a left-right common lens, the lenses other than the eye lens are a left-right pair of lenses, and the left and right optical axes before entering the eye lens are parallel to each other. In the lens system, D is the optical axis interval while the left and right optical axes are substantially parallel, and f is the focal length of the eye lens.
_When it is set to _e , it is characterized by satisfying the following condition (1).

(1) _fe <-3.83D In the present invention, in order to increase the magnification of the eyepiece, the lenses excluding the eye lens are installed in a pair on the left and right with their optical axes substantially parallel and To make the corners, only the eye lens is a single concave lens common to the left and right. Here, there is the following relationship between the focal length f _e of the eye lens, the substantially parallel optical axis interval, and the convergence angle θ.

[0007] sin (θ / 2) = - D / 2f e by the above formula, the convergence angle theta tends to observe it within 15 °, too attaches convergence angle exceeds the 15 ° stereoscopically Zuraku Become. Therefore, if the focal length _fe of the eye lens and the optical axis distance D are within the range satisfying the above condition (1), fusion can be achieved.

Further, in order that most people can reasonably and satisfactorily view stereoscopically, it is desirable that the convergence angle θ be in the following range.

3 ° <θ <8 ° Therefore, the focal length f _e of the eye lens must _satisfy the following condition (2)
It is desirable to be within the range.

(2) −19.1D < _fe <−7.16D Since this eye lens has weak power, it hardly affects aberrations. Therefore, the eye lens may be a single lens. However, particularly in order to correct chromatic aberration, it is preferable to use a glass material having a large Abbe number for this eye lens as in the following condition (3).

(3) ν _e > 60 Here, even if a glass material having a large Abbe number is used for the eye lens, it is difficult to carry out color correction so that the C line and the F line intersect each other. The contours may be colored when you try to observe it. In order to correct this chromatic aberration, it is preferable that the eye lens is a cemented lens.
Here, when the eye lens is a lens in which a concave lens and a convex lens are cemented, and the Abbe number of the convex lens is ν _1p and the Abbe number of the concave lens is ν _1n , by satisfying the following condition (4), the C line and F It is possible to cross the line.

(4) ν _1n > ν _1p Further, in order to facilitate the design in which the C line and the F line cross, ν _1n and ν satisfy the following condition (5):
It is desirable to make the difference of _1p large.

(5) ν _1n −ν _1p > 15 Further, if asymmetrical aberration occurs in the lens system, the image may appear dented when the images are fused with both eyes. In order to avoid this, it is effective to use an aspherical surface for the left and right lenses.

The structure of the eyepiece lens of the present invention comprises, in order from the eye side of the observer, a first group of eye lenses consisting of a concave lens common to the left and right, a convex lens, a meniscus lens having a concave surface facing the eye side, and a convex lens. Second composed of left and right pair
The third lens group includes a group and a negative meniscus lens having a concave surface facing the object side, and includes a pair of left and right lenses.

In the eyepiece having the above construction, the third lens group should have a negative power in order to lengthen the eye relief, and in order to correct the aberration, it is effective to use a cemented lens of a convex lens and a concave lens. Target. The refractive index and Abbe number of the convex lens of the cemented lens of the third group are n _3p and ν _3p , respectively, and the refractive index and Abbe number of the concave lens are n _3p and n ₃ , respectively.
_{When 3n} and ν _3n , it is preferable that the following conditions (6) and (7) are satisfied.

(6) n _3n −n _3p > 0.15 (7) ν _3p −ν _3n > 40 If the above conditions (6) and (7) are not satisfied, peripheral coma and chromatic aberration are deteriorated.

Since the eyepiece of the present invention has the above-mentioned structure, the diameter of the second lens group becomes large due to the light beam expanded by the first lens group, and the left and right lenses interfere with each other. Further, in order to reduce the diameter of the lens , it is effective to use the second lens of the second group as a meniscus lens having a convex surface facing the object side. The focal length f _m of this meniscus lens is preferably set to satisfy the following condition (8).

(8) │f _m │> 500 Further, when the refractive index of this meniscus lens is 1.7 or more, the axial chromatic aberration (point image) can be suppressed. When the refractive index of this lens is 1.7 or less, the resolution deteriorates.

The meniscus lens of the second group can be thickened without deteriorating the optical performance.
By utilizing this fact, a reflecting surface can be provided in the second lens of the second group to bend the optical axis in a substantially vertical direction. Thereby, the object and the position of the observer's eye can be brought close to each other. In the eyepiece of the present invention having the above-described structure, the diameter of the lens is maximized near the object side surface of the meniscus lens which is the second lens of the second group, so that the left and right lenses easily interfere with each other. By bending the optical axis in the second lens, interference between the left and right lenses can be avoided.

[0020]

EXAMPLES Examples of the binocular eyepieces of the present invention are shown below. Example 1 r ₁ = -393.39352 d ₁ = 10.000000 n ₁ = 1.48749 ν ₁ = 70.2 r ₂ = 1065.13991 d ₂ = 3.000000 r ₃ = 53.43526 d ₃ = 8.364285 n ₂ = 1.72916 ν ₂ = 54.7 r ₄ = -188.98746 _{4 = 9.339455 r 5 = -30.81010 d} 5 = 4.000000 n 3 = 1.76182 ν 3 = 26.6 r 6 = 821.18509 d 6 = 18.908563 n 4 = 1.816 ν 4 = 46.6 r 7 = -44.36187 d 7 = 11.349575 r 8 = 96.37447 d _{8 = 9.255946 n 5 = 1.85026 ν} 5 = 32.3 r 9 = -123.37158 d 9 = 0.500000 r 10 = 29.92467 d 10 = 15.282176 n 6 = 1.48749 ν 6 = 70.2 r 11 = -38.30857 d 11 = 3.000000 n 7 = 1.84666 ν _{7 = 23.8 r 12 = 34.06918 d} 12 = 10.000000 r 13 = ∞ ( image plane) D = 61.5434 (mm), θ = 6 °, eye relief = 32 (mm), the exit pupil diameter = 15 (mm) f = 41.67 _{(mm), f e /D=-9.54,} f m = -1970.5 (mm)

Example 2 r ₁ = -1055.39704 d ₁ = 10.000000 n ₁ = 1.816 ν ₁ = 46.6 r ₂ = 229.15045 d ₂ = 7.540827 n ₂ = 1.72825 ν ₂ = 28.5 r ₃ = 1353.78759 d ₃ = 3.000000 r ₄ = _{50.13466 d 4 = 9.304981 n 3 =} 1.72916 ν 3 = 54.7 r 5 = -166.20843 d 5 = 9.018012 r 6 = -34.21157 d 6 = 6.000000 n 4 = 1.84666 ν 4 = 23.8 r 7 = 548.34579 d 7 = 15.049838 n 5 = 1.85026 v ₅ = 32.3 r ₈ = -43.71554 d ₈ = 2.148731 r ₉ = 124.81650 d ₉ = 5.741834 n ₆ = 1.816 v ₆ = 46.6 r ₁₀ = -161.04336 d ₁₀ = 0.500000 r ₁₁ = 36.97694 d ₁₁ = 16.736604 n ₇ = 1.43749 ν ₇ = 70.2 r ₁₂ = -34.07137 d ₁₂ = 4.500000 n ₈ = 1.84666 ν ₈ = 23.8 r ₁₃ = 60.81231 d ₁₃ = 9.999958 r ₁₄ = ∞ (image plane) D = 61.2772 (mm), θ = 6 °, eye relief = 32 (mm), the exit pupil diameter = 15 (mm) f = 41.67 (mm), f e /D=-9.6, f m = 5344.4 (mm)

Example 3 r ₁ = -998.78475 d ₁ = 6.000000 n ₁ = 1.816 ν ₁ = 46.6 r ₂ = 320.83665 d ₂ = 4.150449 n ₂ = 1.84666 ν ₂ = 23.8 r ₃ = 868.10816 d ₃ = 3.000000 r ₄ = 88.56845 d ₄ = 7.538481 n ₃ = 1.7495 v ₃ = 35.3 r ₅ = -48.63474 d ₅ = 3.097683 r ₆ = -37.08448 d ₆ = 6.000000 n ₄ = 1.84666 v ₄ = 23.8 r ₇ = ∞ d ₇ = 60.000000 n ₅ = 1.79952 ν ₅ = 42.2 r ₈ ＝ ∞ d ₈ ＝ 11.000000 n ₆ ＝ 1.72916 ν ₆ ＝ 54.7 r ₉ ＝ -63.87457 d ₉ ＝ 0.500000 r ₁₀ ＝ 58.80763 d ₁₀ ＝ 10.838736 n ₇ ＝ 1.62041 ν ₇ ＝ 60.3 r ₁₁ ＝- 498.24996 d ₁₁ = 0.500000 r ₁₂ = 33.10588 d ₁₂ = 16.542474 n ₈ = 1.6425 ν ₈ = 58.4 r ₁₃ = -79.65138 d ₁₃ = 8.237983 n ₉ = 1.84666 ν ₉ = 23.8 r ₁₄ = 18.22809 d ₁₄ = 7.096020 r ₁₅ (image surface) D = 61.2772 (mm), θ = 6 °, eye relief = 25 (mm), the exit pupil diameter = 15 (mm) f = 41.67 (mm), f e /D=-9.6, f m = -4531.39 (mm) _1, r _2, ··· is the radius of curvature of each lens surface, d
₁ , d ₂ , ... Are the wall thickness and air gap of each lens, n
₁ , n ₂ , ... Is the refractive index of each lens, ν ₁ , ν ₂ ,.
Is the Abbe number of each lens.

In the first embodiment, as shown in FIG. 1, a biconcave first group which is common to the left and right from the eye side, a biconvex lens, a cemented meniscus lens of a negative lens and a positive lens, and a biconvex lens.
And a third group of cemented meniscus lenses of a positive lens and a negative lens. The second group and the third group are composed of a pair of left and right lenses.

In the second embodiment, the first lens group is a cemented lens.
That is, as shown in FIG. 2, a first group of negative cemented lenses in which a negative lens and a positive lens common to the left and right are cemented from the eye side, a biconvex lens, a cemented meniscus lens of a negative lens and a positive lens, and a biconvex lens. It consists of two groups, and a third group of cemented meniscus lenses of a positive lens and a negative lens.

The third embodiment is as shown in FIG.
It has the same structure as the above, but the optical axis is bent by providing a reflecting surface in the second group. The aberrations of the above-mentioned respective examples are as shown in FIGS. These aberration diagrams are aberrations (coma aberration) when light is incident from the eye side, that is, the eye lens side to form an image on the image plane. Further, since the lens system of the present invention is a decentered optical system, the aberrations differ depending on the direction. Therefore, each aberration diagram {(A), (B), ... (H)} is an image as shown in FIG. The aberration diagram which passed through the position of a surface and the opening part of the arrow direction is shown. In FIG. 7, the left side is the image plane of the optical system for the left eye, the right side is the image plane of the optical system for the right eye, and the direction connecting the left and right optical axes is the x direction and the direction perpendicular thereto is the y direction. For example, (A) in the aberration diagram is an aberration diagram when passing through an opening in the x direction (direction connecting left and right optical axes) at the center of the image plane, and is indicated by reference characters A, B, ... In FIG. Aberration diagrams passing through the position on the image plane where the arrow is drawn and the opening in the arrow direction are aberration diagrams (A), (B), ...
The ordinate in the aberration diagram is the aperture ratio. The right side of FIG. 7 on the right eye side is the same as the left side, and since the vertical direction is symmetrical, the lower side aberration is omitted.

The present invention is an eyepiece for binocular vision as described above, and includes not only those described in the claims but also the inventions of the embodiments described in each of the following items.

(1) An eyepiece for binocular vision according to the claims, wherein the focal length _fe of the eye lens satisfies the following condition (2).

(2) -19.1D < _fe <-7.16D (2) What is described in the claims or the above (1), wherein the eye lens is a single lens and its Abbe number is An eyepiece for binocular vision in which ν _e satisfies the following condition (3).

(3) ν _e > 60 (3) In the claims or the above (1), the eye lens is composed of a cemented lens of a convex lens and a concave lens, and the Abbe number ν of the convex lens is An eyepiece for binocular vision in which _1p and the Abbe's number ν _{1n of the} concave lens satisfy the following condition (4).

(4) ν _1n > ν _1p (4) An eyepiece for binocular vision according to the item (3), which satisfies the following condition (5).

(5) ν _1n −ν _1p > 15 (5) The one described in the above item (2), (3) or (4), which is an eye lens consisting of a lens common to the left and right in order from the eye side. It is composed of a first group, a second group having a positive refracting power as a whole, and a third group of negative meniscus lenses having a concave surface facing the object side, and the second and third groups are a left-right pair. Binocular eyepieces.

(6) In the above item (5), the third group is composed of a cemented lens of a convex lens and a concave lens, and the refractive index and the Abbe number of the convex lens of the third group are n.
An eyepiece for binocular vision which satisfies the following conditions (6) and (7), where _3p and ν _3p are the refractive index and Abbe number of the concave lens of the third group are n _3n and ν _3n , respectively.

(6) n _3n −n _3p > 0.15 (7) ν _3p −ν _3n > 40 (7) The second group includes a convex lens and a meniscus lens. An eyepiece for binocular vision comprising a convex lens, wherein the meniscus lens is a lens having a low power with a concave surface facing the eye side.

(8) In the above item (7), the glass material forming the negative meniscus lens of the second group has a refractive index of 1.7 or more, and the meniscus lens of the second group. the focal length f _m eyepiece for binocular vision that satisfies the following condition (8) of the.

(9) The binocular eyepiece according to the item (5), wherein a reflecting surface is provided inside the negative meniscus lens of the second group.

[0036]

The eyepiece of the present invention is a lens system having a pupil diameter of 8 mm or more and a magnification of 5 times or more, which makes it easy to perform observation with vergence.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a second embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a third embodiment of the present invention.

FIG. 4 is an aberration curve diagram of Example 1 of the present invention.

FIG. 5 is an aberration curve diagram of Example 2 of the present invention.

FIG. 6 is an aberration curve diagram of Example 3 of the present invention.

FIG. 7 is an explanatory diagram related to the above-mentioned aberration diagram.

FIG. 8 is a diagram showing a configuration of a conventional binocular eyepiece lens.

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-5-107481 (JP, A) JP-A-8-122666 (JP, A) JP-A-63-313116 (JP, A) JP-A-57- 22219 (JP, A) JP-A-7-140419 (JP, A) JP-A-8-21958 (JP, A) JP-A-3-141314 (JP, A) Actual development Sho-59-94321 (JP, U) (58) Fields studied (Int.Cl. ⁷ , DB name) G02B 9/00-17/08 G02B 21/00-21/36 G02B 23/00-23/22 G02B 25/00-25/04

Claims (9)

(57) [Claims] 1. An eyepiece comprising, in order from the eye side, an eye lens consisting of a common left and right lens and a pair of left and right lenses, the left and right optical axes of which are parallel to each other before entering the eye lens. A binocular eyepiece for a lens system having a diameter of 8 mm or more, wherein the optical axis interval D and the focal length _{fe of the} eye lens while the left and right optical axes are substantially parallel satisfy the following relationship. _fe <-3.83D 2. The binocular eyepiece according to claim 1, which satisfies the following condition (2). (2) -19.1D < _fe <-7.16D 3. The eye lens is a single lens, and its Abbe number ν _e satisfies the following condition (3):
Binocular eyepieces. (3) ν _e > 60 4. The binocular according to claim 1 or 2, wherein the eye lens is composed of a cemented lens of a convex lens and a concave lens, and the Abbe number ν _1p of the convex lens and the Abbe number ν _{1n of the} concave lens satisfy the following condition (4). Eyepiece for vision. (4) ν _1n ＞ ν _1p 5. The binocular eyepiece according to claim 4, which satisfies the following condition (5). (5) ν _1n −ν _1p > 15 6. A first group of eye lenses consisting of a lens common to the left and right in order from the eye side, a second group having a positive refracting power as a whole, and a third group of negative meniscus lenses having a concave surface facing the object side. The binocular eyepiece according to claim 3, 4 or 5, wherein the second and third groups are a left-right pair. 7. The third lens group is composed of a cemented lens of a convex lens and a concave lens, the refractive index and Abbe number of the convex lens of the third group are n _3p and ν _3p , and the refractive index and Abbe number of the concave lens of the third group are When n _3n and ν _3n respectively, the following condition (6),
The eyepiece for binocular vision according to claim 6, which satisfies (7). (6) n _3n −n _3p > 0.15 (7) ν _3p −ν _3n > 40 8. The second group is composed of a convex lens, a meniscus lens and a convex lens, the meniscus lens is a lens having a concave surface facing the eye side, and the refractive index of a glass material forming the meniscus lens is 1.7 or more. The binocular eyepiece according to claim 6, wherein the focal length f _{m of the} meniscus lens satisfies the following condition (8). (8) | f _m |> 500 9. The binocular eyepiece according to claim 6, wherein a reflecting surface is provided inside the negative meniscus lens of the second group.