JPH07191263A - Finder optical system with visual field rate correcting function - Google Patents

Abstract

PURPOSE:To suppress a visual variation rate small while holding a diopter and a parallax correcting function by correcting the visual field rate by moving at least one lens element according to variation in field angle due to the focusing of a photographic optical system. CONSTITUTION:This system is equipped with an objective system l which has a positive refractive index, an ocular system 2 composed of a four-time reflecting prism 3 and a positive lens 4, and a visual field frame (intermediate image formation plane) 5. The objective system 1 constitutes a zoom system formed of four negative, positive, negative, and positive lens groups G1, G2, G3, and G4. When the field angle of the photographic reflection system becomes narrow (wide) as a result of focusing, the lens group G2 (G1 or G4) which becomes large (small) in finder power is moved in the direction of an optical axis Lc to correct the diopter. Consequently, the incidence half field angle of the finder becomes narrow (wide) and variation in visual field rate is reduced. For parallax correction, one of the lens groups constituting the objective system 1 is made eccentric.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finder optical system used in a photographic camera, a video camera or the like.

[0002]

2. Description of the Related Art In general, a finder optical system which is separate from a conventional photographic optical system has a lens that does not move according to a photographing distance, that is, does not have a focusing function. With such a conventional viewfinder optical system, the photographer unknowingly corrects the position shift of the aerial image formed by the viewfinder objective optical system when he looks into the viewfinder, using the focus adjustment function of his eye. It was At this time, the apparent shooting distance L ′ when looking into the viewfinder, that is, the diopter D is determined by the viewfinder angular magnification γ and the shooting distance L, and the following relationship is established. D = 1 / L '= 1 / L × γ ² [1 / m] (1) Since the viewfinder angle magnification γ of the camera is normally γ <1, the diopter change with the shooting distance is in the real field of view. It was smaller than the change in diopter, and there was no problem that the aerial image was out of focus.

However, in recent years, with increasing zooming ratios of zoom compact cameras and the like, the finder optical system angular magnification may become γ> 1 on the telephoto side. In this case, the change in diopter with respect to the shooting distance is larger than the change in diopter in the actual visual field, and the ability to adjust the focus of the eye cannot be fully dealt with, causing a problem that the subject is out of focus and difficult to see.
Also, in a camera with a separate viewfinder optical system, parallax between the viewfinder optical system and the shooting optical system occurs,
It is well known that it is difficult to accurately display the shooting range on the finder screen over the entire shooting distance.

As a means for solving the above two problems, Japanese Patent Laid-Open No. 1-197727 discloses that some of the lenses constituting the finder optical system are set in the optical axis direction and the optical axis according to the photographing distance data and the like. A method is known in which the diopter and the parallax are simultaneously corrected by moving in the vertical direction.

[0005]

However, according to the above method, when a part of the lenses constituting the finder optical system is moved in the optical axis direction, the finder magnification changes and the incident angle of view changes. I will end up. Also in the photographic optical system, the angle of view changes due to focusing, and if the respective amounts of change in the angle of view are not uniform, the field ratio, which is the tangent ratio between the photographic optical system and the incident half angle of view of the finder, greatly deviates. Therefore, even if the shooting optical system is aligned with the center of the viewfinder screen by parallax correction, unnecessary objects outside the viewfinder field may be captured, or conversely, objects within the viewfinder field may not be captured. There was a problem.

In view of the above-mentioned problems of the prior art, the present invention provides a viewfinder optical system which is constructed separately from the photographing optical system, while changing the visual field ratio while maintaining the diopter and parallax correction functions. It is an object of the present invention to provide a finder optical system having a field-of-view correction function that can reduce the number of pixels.

[0007]

In order to achieve the above object, a finder optical system having a visual field correction function according to the present invention has the following features. (1) In a finder optical system having a diopter and parallax correction function, which is configured separately from the photographic optical system, at least one lens component of the finder optical system is set in accordance with a change in angle of view due to focusing of the photographic optical system. It was moved to correct the field of view. (2) The diopter and the field of view are corrected by moving at least one lens component on the object side from the intermediate image plane of the finder optical system.

(3) In a finder optical system having a parallax correction function, which is formed separately from the photographing optical system, a lens component which is disposed closer to the object side than the intermediate image plane and which satisfies the following conditional expression: At least it should be moved in the optical axis direction to correct the diopter. 0.7 ≦ P / Δω _T × γ / γ ′ ≦ 1.0 (2) where Δω _T = tan ω _T ′ / tan ω _T ω _T : half angle of view ω of the shooting lens at normal time ω _T ': Half-field angle of incidence of the photographing lens during diopter correction γ: Normal viewfinder magnification γ': Viewfinder magnification during diopter correction P: Normal view ratio

(4) In the finder optical system having a parallax correction function, which is formed separately from the photographing optical system, a lens component which is disposed closer to the object side than the intermediate image plane and which satisfies the following conditional expression: At least it should be moved in the optical axis direction to correct the diopter. 0.9 ≦ 1 / Δω _T × γ / γ ′ ≦ 1.1 (3) (5) Parallax by decentering at least one lens component on the object side of the intermediate image plane of the finder optical system. I tried to correct it. (6) The parallax is corrected by changing the display range of the viewfinder optical system.

[0010]

The function of the present invention will be described below. When a part of the lenses constituting the finder objective system is moved in the optical axis direction for focusing, that is, diopter correction, the following relationship is established between the movement of the correction lens and diopter change. ^{_{α F = M F 2 -M C}} 2 ···· (4) Δs = αF × Δd ···· (5) ΔD = 1000 × Δs / f R 2 ···· (6) ΔD C = -ΔD ··· (7) That is, Δd = ΔD _C / 1000 × f _R ² / α _F ··· (8) where α _{F is} the vertical magnification of the focus lens M _{F is} the horizontal distance from the correction lens to the intermediate image Magnification M _C : Lateral magnification from the rear of the correction lens to the intermediate image f _R : Eyepiece focal length [mm] Δd: Correction lens movement amount [mm] Δs: Image formation position shift at intermediate image position [mm] ΔD: Diopter deviation [1 / m] ΔD _C : Diopter correction amount [1 / m].

When Δd is a negative value, the lens is extended, and when it is a positive value, the lens is extended. For example, when the object distance changes from infinity to the closest distance, the diopter deviation amount ΔD becomes a negative value, and the diopter correction amount ΔD _C becomes a positive value. Therefore, if the vertical magnification α _F of the diopter correction lens component is a negative value, the lens is extended,
If it is a positive value, the lens will be retracted. When the lens is moved in the optical axis direction to correct the diopter, the paraxial relation of the objective system changes and the objective focal length changes. At this time,
Since the focal length of the eyepiece system does not change, the viewfinder magnification γ also changes by the change of the objective system.

Further, when a part of the lens units constituting the viewfinder objective system is decentered, the viewfinder optical axis tilts,
The parallax with the shooting optical system can be corrected. In this case, a lens group different from the lens group for diopter correction may be decentered, or the diopter correction lens group may be decentered at the same time as the movement in the optical axis direction.

From the intermediate image height I and the objective focal length f _OB , the incident half angle of view ω _F of the finder is ω _F ≈tan ^-1 (I /
f _OB ). Therefore, angle omega _F when f _OB longer becomes narrow, angle omega _F when f _OB is shorter becomes wider. Therefore, when the angle of view of the photographic optical system is narrowed (widened) due to focusing, if the diopter correction is performed with a lens group that increases the viewfinder magnification (smaller), the angle of view ω _F becomes narrower (wider) and the change in the field of view is reduced. it can.

The field ratio after the diopter correction can be approximately calculated according to the conditional expression (2), and it is preferable that the following condition is satisfied. 0.7 ≦ P / Δω _T × γ / γ ′ ≦ 1.0 (2) where Δω _T = tan ω _T ′ / tan ω _T ω _T : half angle of view ω of the shooting lens at normal time ω _T ': Half-field angle of incidence of the photographing lens during diopter correction γ: Normal viewfinder magnification γ': Viewfinder magnification during diopter correction P: Normal view ratio

However, when the value of the conditional expression (2) is below the lower limit of the range of possible values, the field of view becomes small,
It even shoots extra objects outside the viewfinder.
If the value of the conditional expression (2) exceeds the upper limit of the range of possible values, the field of view may exceed 100%, and even an object in the finder field may not be photographed. Further, it is more preferable that the visual field ratio after the diopter correction satisfies the conditional expression (3). 0.9 ≦ 1 / Δω _T × γ / γ ′ ≦ 1.1 (3) However, when the value of conditional expression (3) exceeds the upper limit or the lower limit of the range of possible values, the object distance is reduced. The change in the field of view due to the change becomes large, which is not preferable.

[0016]

The present invention will be described in detail below with reference to the illustrated embodiments. First Embodiment FIG. 1 is a sectional view taken along the optical axis of a finder optical system having a correction function according to the present embodiment, in which (a) is a low magnification end state and (b) is a high magnification end state. It is the figure shown respectively.
As shown in the figure, the optical system of this embodiment includes an objective system 1 having a positive refractive power, an eyepiece system 2 including a four-reflection prism 3 and a positive lens 4, and a field frame (intermediate image plane). 5 is arranged between the objective system 1 and the eyepiece system 2. Further, the objective system 1 constitutes a zoom including four lens groups of negative (G ₁ ), positive (G ₂ ), negative (G ₃ ), and positive (G ₄ ), and any one of the lens groups is used as an optical axis. The diopter can be corrected even if it is moved in the L _C direction. The parallax correction can be performed by decentering any of the lens groups forming the objective system 1.

The numerical data of the finder optical system in this embodiment will be shown below. r ₁ = -16.4440 _{(aspherical) d 1 = 1.000 n 1 =} 1.58362 ν 1 = 30.37 r 2 = 128.2560 d 2 = 9.1300 ( Teibaitan), 1.679 _{(Kobaitan) r 3 = 7.6560 d 3 =} 5.220 n 3 = 1.49260 ν ₃ = 58.02 r ₄ = -13.8000 (aspherical surface) d ₄ = 5.6710 (low magnification end), 1.049 (high magnification end) r ₅ = -36.5900 d ₅ = 1.000 n ₅ = 1.58362 ν ₅ = 30.37

[0018] r ₆ = 71.2090 (aspherical) d ₆ = 5.0910 (Teibaitan), 17.164 _{(Kobaitan) r 7 = 13.6360 d 7 =} 2.900 n 7 = 1.49260 ν 7 = 58.02 r 8 = ∞ d 8 = 1.000 _{r 9 = 33.4050 d 9 = 39.500} n 9 = 1.49260 ν 9 = 58.02 r 10 = ∞ d 10 = 1.000

R ₁₁ = 17.5090 d ₁₁ = 2.500 n ₁₁ = 1.49260 ν ₁₁ = 58.02 r ₁₂ = -64.3960 (aspherical surface) d ₁₂ = 13.500 r ₁₃ (eye point)

Aspheric surface coefficient First surface P = 1.0000 E = 0.30788 × 10 ^-4 , F = -0.40427 × 10 ^-4 G = 0.62311 × 10 ^-5 Fourth surface P = 1.0000 E = 0.65521 × 10 ^-3 , F = 0.58398 × 10 ^-5 G = 0.10530 × 10 ^-6 6th surface P = 1.0000 E = 0.86696 × 10 ^-5 , F = -0.19119 × 10 ^-6 G = 0.35113 × 10 ^-6 12th surface P = 1.0000 E = 0.49100 x 10 ^-4 , F = -0.17743 x 10 ^-5 G = 0.42481 x 10 ^-7

Parallax correction in this embodiment will be described with reference to FIG. The figure (a) has shown the normal state, and the figure (b) has shown the state after correction, respectively. As shown in the figure, the parallax correction in this embodiment is performed by decentering a part of the lens that constitutes the objective system of the finder optical system. That is, the negative first group G ₁ which is a component of the objective system 1 is set to the optical axis L.
_By moving in the direction perpendicular to _C (the direction of the arrow in the figure), the optical axis L _C is tilted in the direction opposite to the moving direction of the first group G ₁ , and parallax correction is performed.

Next, the diopter correction will be described. Implementation
The photographic optical system of the camera in the example is as shown in FIG.
And the negative first group G _FiveAnd the positive second group G₆Zoom with and
Use the one configured as a lens. Same figure
(A) shows the state at the low-magnification end, and (b) shows the state at the high-magnification end.
are doing. This photographing optical system is the first group G_FiveTo feed
Therefore, when focusing is performed, the angle of view will change from infinity to close range.
Is becoming wider.

The numerical data of the photographing optical system used in this embodiment are shown below. r ₁ = 215.0200 d ₁ = 1.830 n ₁ = 1.80400 ν ₁ ＝ 46.57 r ₂ = 17.1590 (aspherical surface) d ₂ ＝ 6.7700 r ₃ ＝ 27.0920 d ₃ ＝ 3.000 n ₃ ＝ 1.76182 ν ₃ ＝ 26.52 r ₄ ＝ 58.3920 d ₄ = 20.917 (Teibaitan), 4.148 (Kobaitan) r ₅ = ∞ (aperture) d ₅ = 1.000

R ₆ = 13.4650 (aspherical surface) d ₆ = 7.520 n ₆ = 1.56873 ν ₆ = 63.16 r ₇ = -17.6940 d ₇ = 1.500 n ₇ = 1.63636 ν ₇ = 35.37 r ₈ = 114.7790 d ₈ = 4.710 r ₉ = -45.6040 _{(aspherical) d 9 = 1.880 n 9 =} 1.77250 ν 9 = 49.66 r 10 = -127.6830 d 10 = 0.000

Aspheric coefficient 2nd surface P = 1.2761 E = -0.19169 × 10 ^-4 , F = -0.12866 × 10 ^-7 G = -0.52470 × 10 ^-9 6th surface P = 0.9460 E = 0.57808 × 10 ^-5 , F = 0.10384 × 10 ^-6 G = 0.49381 × 10 ^-9 , H = 0.80171 × 10 ^-11 9th surface P = 1.6587 E = -0.91883 × 10 ^-4 , F = -0.44647 × 10 ^-6 G = -0.14988 × 10 ^-7

Therefore, the focusing of the photographing optical system is performed.
In the case of performing finder diopter correction according to
First group G of the finder optical system of₁Or the fourth group G_FourThe light
Axis L _CDiopter correction by moving in the direction
And the viewfinder magnification becomes smaller, and as a result, the field of view
The change in can be suppressed to a small level.

At this time, the angle of view of the photographing optical system, the finder magnification, and the values of the conditional expressions (2) and (3) are shown in the following Table 1-1.
It is shown in Table 1-2.

Further, focusing of the photographing optical system may be performed by moving the first group G ₅ and the second group G ₆ together. In this case, the photographing optical system has a narrow angle of view from infinity to a close distance. Therefore, when the second group G ₂ of the finder optical system of this embodiment is moved in the direction of the optical axis L _C to correct the diopter, the finder magnification becomes large, and as a result, the change in the field of view can be suppressed small.

At this time, the angle of view of the photographing optical system, the finder magnification, and the values of conditional expressions (2) and (3) are shown in Table 2-1 below.
It is shown in Table 2-2.

Second Embodiment FIGS. 4A and 4B are sectional views of the finder optical system according to the present embodiment taken along the optical axis. FIG. 4A shows a low magnification end state, and FIG. 4B shows a high magnification end state. It is the figure shown. As shown in the figure, the optical system of this embodiment includes an objective system 1 having a positive refractive power, an eyepiece system 2 including a four-reflection prism 3 and a positive lens 4, and a field frame 5 as the objective system 1. It is arranged between the eyepiece system 2 and the eyepiece system 2. Further, the objective system 1 constitutes a zoom lens composed of three lens groups of negative (G ₁ ), positive (G ₂ ), and positive (G ₃ ), and any one of the lens groups is moved in the optical axis L _C direction. Even if it is done, the diopter can be corrected. or,
The parallax correction can be performed by decentering any of the lens groups forming the objective system 1.

Numerical data of the finder optical system in this embodiment will be shown below. r ₁ = -5.474 (aspherical surface) d ₁ = 1.0 n ₁ = 1.5842 ν ₁ = 30.5 r ₂ = -469.147 d ₂ = 3.714 (low magnification end), 0.950 (high magnification end) r ₃ = 18.744 d ₃ = 3.0 n ₃ = 1.4924 ν ₃ = 57.7 r ₄ = -5.592 (aspherical surface) d ₄ = 17.100 (low magnification end), 27.250 (high magnification end) r ₅ = 14.255 d ₅ = 3.0 n ₅ = 1.492 ν ₅ = 57.7

R ₆ = ∞ d ₆ = 2.0 r ₇ = ∞ d ₇ = 39.5 n ₇ = 1.4924 ν ₇ = 57.7 r ₈ = -60.000 d ₈ = 1.0 r ₉ = 24.248 (aspherical surface) d ₉ = 2.5 n ₉ = 1.4924 ν ₉ = 57.7 r ₁₀ = -63.120 d ₁₀ = 13.5 r ₁₁ (eyepoint)

Aspheric surface coefficient First surface P = 1.0 E = -0.43262 × 10 ^-3 , F = -0.74538 × 10 ^-4 G = 0.12197 × 10 ^-4 Fourth surface P = 1.0 E = 0.45952 × 10 ^-3 , F = 0.69408 × 10 ^-5 G = 0.94103 × 10 ^-6 9th surface P = 1.0 E = 0.57843 × 10 ^-4 , F = -0.47032 × 10 ^-5 G = 0.79080 × 10 ^-7

Also in this embodiment, focusing is performed using the photographing optical system of the camera used in the first embodiment. When focusing is performed by moving out the first group G ₅ of this photographing optical system, the angle of view becomes wide from infinity to a close distance. Therefore, when the finder diopter correction is performed in accordance with the focusing of the photographing optical system, the diopter correction is performed by moving the second group G ₂ of the optical system of the present embodiment in the optical axis L _C direction. The magnification is reduced, and the change in field of view can be suppressed.

At this time, the angle of view of the photographing optical system, the finder magnification, and the values of the conditional expressions (2) and (3) are shown in Table 3-1 below.
It is shown in Table 3-2.

Third Embodiment FIG. 5 is a cross-sectional view of the finder optical system according to the present embodiment taken along the optical axis. FIG. 5A shows a low magnification end state, and FIG. 5B shows a high magnification end state. It is the figure shown. As shown in the figure, the optical system of this embodiment includes an objective system 1 including a single-reflection prism and having a positive refractive power, a triple-reflection prism 3 and a positive lens 4.
And the field frame 5 is arranged between the objective system 1 and the eyepiece system 2. Further, the objective system 1 constitutes a zoom lens composed of four lens groups of negative (G ₁ ), positive (G ₂ ), positive (G ₃ ), and positive (G ₄ ), and the first (G ₁ ) The diopter can be corrected by moving any one of the third to third (G ₃ ) lens groups in the optical axis L _C direction. Further, parallax correction can be performed by decentering any of the lens groups forming the objective system 1.

The numerical data of the finder optical system in this embodiment are shown below. r ₁ = 427.621 d ₁ = 1.0 n ₁ = 1.5842 ν ₁ = 30.5 r ₂ = 21.907 (aspherical surface) d ₂ = 4.83 r ₃ = -26.983 d ₃ = 1.0 n ₃ = 1.5842 ν ₃ = 30.5 r ₄ = 97.412 d ₄ = 13.381 (Teibaitan), 3.795 (Kobaitan) r ₅ = 5.250 _{(aspherical) d 5 = 3.7 n 5 =} 1.4924 ν 5 = 57.7

R ₆ = -25.997 d ₆ = 0.2 r ₇ = 1.548 d ₇ = 2.41 n ₇ = 1.5842 ν ₇ = 30.5 r ₈ = 3.900 d ₈ = 1.500 (low magnification end), 6.181 (high magnification end) r ₉ = 9.536 _{(aspherical) d 9 = 1.75 n 9 =} 1.4924 ν 9 = 57.7 r 10 = 108.900 d 10 = 1.000 ( Teibaitan), 5.906 (Kobaitan)

R ₁₁ = ∞ d ₁₁ = 12.0 n ₁₁ = 1.4924 ν ₁₁ = 57.7 r ₁₂ = -11.590 d ₁₂ = 0.7 r ₁₃ = ∞ d ₁₃ = 29.0 n ₁₃ = 1.4924 ν ₁₃ = 57.7 r ₁₄ = ∞ d ₁₄ = 0.7 r ₁₅ = 17.326 (aspherical surface) d ₁₅ = 2.3 n ₁₅ = 1.4924 ν ₁₅ = 57.7 r ₁₆ = -24.527 d ₁₆ = 15.0 r ₁₇ (eye point)

The aspherical coefficients second surface P = 1.0 E = 0.11783 × 10 -3, F = -0.11803 × 10 -4 G = 0.20704 × 10 -6 fifth surface P = 1.0 E = -0.86055 × 10 -3, F = -0.51448 × 10 ^-5 G = -0.10653 × 10 ^-5 9th surface P = 1.0 E = 0.39471 × 10 ^-3 , F = -0.36821 × 10 ^-4 G = 0.14630 × 10 ^-5 15th surface P = 1.0 E = -0.11542 x 10 ^-3 , F = 0.34242 x 10 ^-5 G = -0.69852 x 10 ^-7

Also in this embodiment, focusing is performed by using the photographing optical system of the camera used in the first embodiment. When focusing is performed by moving out the first group G ₅ of this photographing optical system, the angle of view becomes wide from infinity to a close distance. Therefore, when the finder diopter correction is performed in accordance with the focusing of the photographing optical system, the diopter correction is performed by moving the first lens of the first group G ₁ of the optical system of this embodiment in the optical axis L _C direction. If this is done, the viewfinder magnification will be reduced, and changes in the field of view can be suppressed.

At this time, the angle of view of the photographing optical system, the finder magnification, and the values of the conditional expressions (2) and (3) are shown in Table 4-1 below.
It is shown in Table 4-2.

However, in each of the above embodiments, r ₁ ,
r ₂ , ..., Radius of curvature of each lens surface, d ₁ , d ₂ ,
... is the thickness of each lens or the lens spacing, n ₁ ,
n ₂ , ..., Refractive index of each lens, ν ₁ , ν ₂ ,
・ ・ Is the Abbe number of each lens. The aspherical surface shape in each of the above embodiments is expressed by the following equation using the aspherical surface coefficient. However, x is a coordinate in the optical axis direction, y is a coordinate in a direction perpendicular to the optical axis, r is a paraxial radius of curvature, and E, F, G, and H are aspherical coefficients, respectively.

Fourth Embodiment A parallax correction method according to this embodiment will be described with reference to FIG. The figure (a) has shown the normal state, and the figure (b) has shown the state after correction, respectively. The parallax correction according to this embodiment is performed by moving the field frame. In this case, the field frame 5 is provided with positioning pins 6 in the long groove portions 5a and 5b provided therein.
By inserting a and 6b, the direction perpendicular to the optical axis L _C (direction perpendicular to the drawing) (direction of arrow in the drawing)
It is configured to be slidable. Therefore, parallax correction can be performed by shifting the viewfinder field range. The structure of the finder optical system, the diopter correction method thereof, and the structure of the photographing optical system in this embodiment are the same as those shown in the first to third embodiments.

Fifth Embodiment A parallax correction method according to this embodiment will be described with reference to FIG. The figure (a) has shown the normal state, and the figure (b) has shown the state after correction, respectively. The parallax correction in this embodiment is performed by changing the display of the visual field range. The field frame 5 has a double structure of a plate portion 5c (outside) and a liquid crystal portion 5d (inside), and the liquid crystal portion 5d is composed of a liquid crystal lower portion 5d ₁ and a liquid crystal upper portion 5d ₂ . And the lower part of the liquid crystal 5d
By switching the liquid crystal display between ₁ and the liquid crystal upper part 5d ₂ , the display of the visual field range can be changed. That is, the normal state and light shielding portions of the liquid crystal lower 5d ₁ is set to transmit the portion of the liquid crystal upper 5d _2, by the shielding liquid crystal upper 5d ₂ and transmitted through the liquid crystal lower 5d _1, shown in the second embodiment The same effect as the method can be obtained. The structure of the finder optical system, the diopter correction method thereof, and the structure of the photographing optical system in this embodiment are the same as those shown in the first to third embodiments.

[0046]

As described above, the finder optical system having the visual field correction function according to the present invention has a visual field even if the diopter and parallax are corrected in the finder optical system provided separately from the photographing optical system. It has an advantage in practical use that the rate change can be suppressed to a small level.

[Brief description of drawings]

FIG. 1 is a cross-sectional view taken along the optical axis direction of a finder optical system having a visual field correction function according to a first embodiment of the present invention, in which (a) is a low magnification end state and (b) is a high magnification end. It is the figure which showed each state of.

2A and 2B are explanatory diagrams of parallax correction by eccentricity of an objective system according to the first embodiment of the present invention, FIG. 2A is a normal state and FIG. 2B is a diagram after correction.

FIG. 3 is a cross-sectional view taken along the optical axis direction of a photographing optical system used in the first embodiment of the present invention, in which (a) is a low magnification end state and (b) is a high magnification end state. It is the figure shown.

4A and 4B are cross-sectional views of an optical system according to a second embodiment of the present invention taken along the optical axis direction, in which FIG.
[Fig. 3] is a diagram showing states of high magnification end.

5A and 5B are cross-sectional views of an optical system according to a third embodiment of the present invention taken along the optical axis direction, where FIG.
[Fig. 3] is a diagram showing states of high magnification end.

6A and 6B are explanatory diagrams of parallax correction by moving a field frame according to a fourth embodiment of the present invention, where FIG. 6A is a normal state and FIG.
[Fig. 4] is a diagram showing the respective states after correction.

FIG. 7 is an explanatory diagram of parallax correction by changing the visual field range display according to the fifth embodiment of the present invention, FIG.
(B) is the figure which respectively showed the state after correction.

[Explanation of symbols]

1 Objective System 2 Eyepiece System 3 Prism 4 Positive Lens 5 Field Frame 5a, 5b Long Groove 5c Plate 5d Liquid Crystal 5d ₁ Liquid Crystal Lower 5d ₂ Liquid Crystal Upper 6a, 6b Positioning Pin G ₁ Objective 1st Group G ₂ Objective the second group G ₃ objective third group G ₄ objective fourth group G ₅ photographing optical system first group G ₆ photographing optical system second group of the of the

Claims (6)

[Claims] 1. A diopter constructed separately from the photographing optical system,
In the viewfinder optical system with parallax correction function, according to the change of the angle of view due to the focusing of the shooting optical system,
A finder optical system having a field-of-view correction function, characterized in that at least one lens component of the finder optical system is moved to correct the field-of-view. 2. The diopter and the field of view are corrected by moving at least one lens component on the object side of the intermediate image plane of the finder optical system. A viewfinder optical system with a field of view correction function. 3. A finder optical system having a parallax correction function, which is formed separately from a photographing optical system, wherein at least a lens component which is disposed closer to the object side than an intermediate image plane and which satisfies the following conditional expression: A finder optical system having a visual field correction function, characterized in that the diopter is corrected by moving the optical axis direction. 0.7 ≦ P / Δω _T × γ / γ '≦ 1.0 where Δω _T = tan ω _T ' / tan ω _T ω _T : half angle of view of the shooting lens incident at normal time ω _T ': when diopter correction Half angle of view of the taking lens γ: Viewfinder magnification during normal operation γ ′: Viewfinder magnification during diopter correction P: Normal viewing area ratio. 4. A finder optical system having a parallax correction function, which is configured separately from a photographing optical system, wherein at least a lens component which is disposed closer to the object side than the intermediate image plane and which satisfies the following conditional expression is satisfied. A finder optical system having a visual field correction function, characterized in that the diopter is corrected by moving the optical axis direction. 0.9 ≦ 1 / Δω _T × γ / γ ′ ≦ 1.1 5. The visual field correction function according to claim 2, wherein at least one lens component on the subject side of the intermediate image plane of the finder optical system is decentered to perform parallax correction. Viewfinder optical system. 6. A finder optical system having a field-of-view correction function according to claim 2, wherein parallax correction is performed by a change in a field-of-view range display of the finder optical system.