JP2000111802A - Observation optical system and observation device provided with the system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an observation optical system and an observation device using the same capable of observing an excellent object image by correcting image blur caused by hand shake in binoculars and a telescope. SOLUTION: In this observation optical system where the object image formed by an objective lens 101 is formed as an erect normal image through an image inversion means 103 so as to be observed by an ocular; the lens 101 is provided with three lens groups, that is, a 1st lens group having positive refractive power, a 2nd lens group having negative refractive power and a 3rd lens group having the positive refractive power in order from an object side, and the observation optical system satisfies ΔS=(1-1/M)fobj.tan W assuming that the focal distance of the lens 101 is (fobj) and the magnification of the observation optical system is M when the variation ΔS of the position of the object image formed by the lens 101 caused when the observation optical system is tilted by W is corrected by moving at least one lens group constituting the lens 101 in a direction perpendicular to an optical axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an observation optical system and an observation apparatus using the same, and more particularly, to a function of optically correcting image blur caused by camera shake when using binoculars or a telescope. It is suitable for binoculars, telescopes, and the like having an anti-vibration function.

[0002]

2. Description of the Related Art When observing an object (object image) with an observation optical system such as a binocular or a telescope, camera shake (vibration) becomes a problem as the magnification of the binocular or the telescope increases. If camera shake occurs, the optical performance of the binoculars and the telescope is impaired, and it becomes difficult to perform detailed observation. In the past, when performing detailed observations and observations, the method of fixing binoculars and telescopes to a tripod to prevent camera shake was adopted, but considering the weight and size of the tripod, it is not portable. Hard to say.

A technique for eliminating camera shake by disposing a means for correcting camera shake in an optical system such as binoculars without using a tripod or the like is disclosed in, for example, JP-A-6-43365. FIG. 25 is a diagram for explaining the outline of the technology disclosed in the publication.

In FIG. 1, P101 denotes an objective lens, P102 denotes a variable apex prism, P103 denotes a prism for image inversion, and P104 denotes an eyepiece.

As shown in the figure, a variable apex angle prism P1
02 is located between the objective lens P101 and the prism P103.

This observation optical system has a shake detecting means. Based on a signal detected by the shake detecting means, the variable apex angle prism P102 is driven to change the apex angle of the prism to change the image blur. Is corrected to stabilize the observation image.

[0007] Camera shake is a serious problem not only in the observation optical system but also in taking photographs. Means for correcting such camera shake of a photographic lens are disclosed in, for example, JP-A-7-2797, JP-A-2-234115, JP-A-2-124521, and JP-A-1-16619. FIG.
FIG. 6 is a diagram showing an outline of the technology, taking up JP-A-7-2797.

This technology is an optical system which can correct a position where an image can be formed by moving a part of a photographic lens in parallel with an optical axis. In addition, by keeping the position of the image on the image plane constant, deterioration of image quality due to camera shake is reduced. The method of correcting the camera shake by moving the lens in the optical system in a plane perpendicular to the optical axis will be hereinafter referred to as shift image stabilization.

[0009] The optical action of this technique will be briefly described. FIG. 27 shows the configuration of the camera very simply, in which P201 is a lens, P202 is an image plane, and P20
Reference numeral 3 denotes an optical axis. A subject (not shown) is located on the opposite side of the image plane P202 with respect to the lens P201 in the figure, and light P204 from the subject passes through the lens P201 and passes through the image plane P2.
02 to the IP on 02.

Next, the case where camera shake occurs when taking a picture will be described. FIG. 27B is a diagram illustrating a case where camera shake occurs and the camera is tilted W. In FIG. 27B, the image point IP formed on the optical axis P203
Forms an image at a position ΔY off the optical axis.

Assuming now that the focal length of the lens P201 is flens, ΔY is expressed as ΔY = flens tan W with respect to the case of FIG.

FIG. 27C is a schematic diagram for explaining a case where the camera shake is corrected by shifting the lens P201 when the camera shake occurs. As shown in the figure, if the lens P201 is shifted in the direction perpendicular to the optical axis by Δs, the image point moves by Δs. Therefore, camera shake can be corrected by configuring the lens to shift according to the camera shake amount.

In FIG. 27, the entire lens is shifted, but camera shake can be corrected by moving a part of the lens as disclosed in Japanese Patent Laid-Open No. 7-2797. In this case, as described in Japanese Patent Application Laid-Open No. 7-2797, the lens shift with respect to the correction at the time of camera shake is performed by the lateral magnification of the image of the group for moving the lens and the lateral magnification of the lens group following the group for moving. The quantity Δs is determined.

[0014]

When a variable apex angle prism as disclosed in JP-A-6-43365 is used to correct camera shake, a larger variable apex is required for an objective lens system having a large aperture. A square prism is required.

In the technique disclosed in Japanese Patent Application Laid-Open No. 7-2797 or the like, it is possible to correct eccentric aberration that occurs at the time of camera shake correction by appropriately arranging the optical system.

However, if such an optical system is applied to an observation optical system such as a binocular or a telescope as it is, the size of the optical system increases and the weight increases. Also, no consideration is given to arranging means for inverting an image required for binoculars, telescopes and the like, for example, a prism and the like.

As described above, camera shake correction of a photographic lens is to correct an optical system so that its image point does not move on an image plane. The effect is difficult to obtain.

FIG. 28 is a view for explaining a state of camera shake in the observation optical system. In the figure, P301 denotes an objective lens system, P302 denotes an image plane of the objective lens system, P303 denotes an optical axis, and P304 denotes an object. P305 represents the eyepiece, and P306 represents the eye of the observer.

FIG. 28A shows a state in which camera shake does not occur. As shown in FIG. 1A, a light beam from an object passes through an objective lens, forms an image on an image plane, and exits through an eyepiece.

The following description is based on the assumption that the focal length of the objective lens is fobj and the focal length of the eyepiece is feye.

FIG. 28B shows a state in which camera shake has occurred. When the observation optical system is tilted W, an image is formed at a position of ΔY = fobj tan W in the figure. Therefore, the inclination at the time of exiting the eyepiece is W ′ = tan ⁻¹ (ΔY / feye). The magnification M of binoculars or the like is usually represented by M = fobj / feye. If W is very small, W '= MW. Therefore, the blur in the field of view is the magnification M of the binoculars or the like.
It will be enlarged by the minute.

FIG. 28C shows a case where the image is corrected so that the image does not move relative to the image plane due to the shift similarly to a photographic lens or the like. In this case, as shown in FIG. 28C, the light is emitted in parallel to the optical axis of the eyepiece, and the light is incident on the eye with an inclination, which is effective but not sufficient for correcting camera shake. .

US Pat. No. 3,964,817 and the like disclose a technique relating to such camera shake correction of an observation optical system. The camera shake correction of the observation optical system is the same as that described in US Pat. No. 3,964,817, and cannot be used as it is because it is not based on shift image stabilization.

According to the present invention, in an observation optical system for observing an object image formed by an objective lens as an erect image with an eyepiece using an image inverting means such as an erect prism, a part of the lens group of the objective lens is used. It is an object of the present invention to provide an observation optical system capable of properly correcting image shake due to camera shake by appropriately setting a shift image stabilizing mechanism that moves in a direction perpendicular to the optical axis, and an observation apparatus using the same.

[0025]

According to the present invention, there is provided an observation optical system comprising: (1-1) an observation optical system for observing an object image formed by an objective lens as an erect image via an image inverting means with an eyepiece. The objective lens includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. The amount of change ΔS in the position of the object image formed by the objective lens caused when the observation optical system is tilted by W is moved by moving at least one lens group constituting the objective lens in a direction perpendicular to the optical axis. When correcting, the focal length of the objective lens is fobj, and when the magnification of the observation optical system is M, ΔS = (1-1 / M) fobj · tan W ‥‥‥ (1) is satisfied. I have.

In particular, (1-1-1) the focal length of the first lens group of the objective lens is f
1. The distance between the first lens group and the second lens group is D12
0.5 <f1 / fobj <0.8 ‥‥‥ (2) 0.05 <D12 / fobj <0.5 ‥‥‥ (3)

(1-1-2) The image blur is corrected by moving the second lens group of the objective lens in a direction perpendicular to the optical axis, and the first lens group has a positive lens and a negative lens. And
When the Abbe number of the material of the positive lens is ν1p, 60 <ν1p ‥‥‥ (4) is satisfied.

(1-2) In an observation optical system for observing an object image formed by an objective lens as an erect image via an image inverting means and using an eyepiece lens, an object image formed by the objective lens is converted by the inverting means. A first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power. The objective lens includes three lens groups, and a change in the position of an object image formed by the objective lens, which occurs when the observation optical system is tilted, is changed by moving at least one lens group constituting the objective lens perpendicular to the optical axis. It is characterized in that the correction is made by moving in the direction.

In particular, (1-2-1) the focal length of the first lens group of the objective lens is f
1. The distance between the first lens group and the second lens group is D12
0.5 <f1 / fobj <0.8 ‥‥‥ (2) 0.05 <D12 / fobj <0.5 ‥‥‥ (3)

(1-2-2) The image blur is corrected by moving the second lens group of the objective lens in a direction perpendicular to the optical axis, and the first lens group has a positive lens and a negative lens. And
When the Abbe number of the material of the positive lens is ν1p, 60 <ν1p ‥‥‥ (4) is satisfied.

The observation apparatus of the present invention comprises: (2-1) an observation optical system for observing an object image formed by an objective lens as an erect image via an image inverting means with an eyepiece;
A blur detecting means for detecting a blur amount of the observation optical system, and an optical path deflecting means for deflecting an optical path in the objective lens based on a signal from the blur detecting means to correct image blur. In the above observation apparatus, the optical path changing means has a lens driving mechanism for moving some or all of the lenses in the objective lens in a direction perpendicular to the optical axis.

In particular, (2-1-1) the objective lens is characterized in that it has a first lens group having a fixed positive refractive power and a plurality of lens groups following the first lens group when correcting blur.

(2-1-2) The objective lens includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. It has three lens groups, and is characterized in that the second lens group is moved in a direction perpendicular to the optical axis to correct image blurring when the observation optical system is tilted.

(2-1-3) The focal length of the objective lens is fob
j, when the focal length of the first lens group of the objective lens is f1, and the distance between the first lens group and the second lens group is D12, 0.5 <f1 / fobj <0.8 ‥‥‥ (2 0.05 <D12 / fobj <0.5 (3)

(2-1-4) The first lens group has a positive lens and a negative lens. When the Abbe number of the material of the positive lens is ν1p, 60 <ν1pｐ (4) Is satisfied.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of the configuration of the optical system according to the present invention will be described.

FIG. 29 is a schematic diagram showing the configuration of an objective lens system and image reversing means of a very common telescope / binocular. P in the figure
Reference numeral 501 denotes an objective lens. In general, it is configured by joining a positive lens and a negative lens to correct chromatic aberration. p502 is the image plane, p503 is the optical axis, p5
Reference numeral 04 denotes an image reversing unit.

When performing shift stabilization in order to correct image blur in the objective lens system having such a configuration, the entire objective lens p501 is moved in a direction perpendicular to the optical axis p503.

When a large light-collecting power is required as used for astronomical observation or the like, the diameter of the objective lens becomes large. Therefore, in the case where shift anti-shake is added in such a configuration, the objective lens is large and heavy. Therefore, a large output is required for the driving means for driving the objective lens, and the size of the actuator is increased. Further, when the focal length of the objective lens is increased in order to increase the magnification as the observation optical system, there is a problem that the entire length of the lens of the optical system is increased.

In order to prevent the total length of the lens from becoming long,
The objective lens system is divided into a positive lens group and a negative lens group arranged apart from it, and the main point of the objective lens system is set closer to the object side than the positive lens, thereby shortening the overall length. There is an objective lens.

FIG. 30 shows a teletype objective lens p60.
0 shows an example of the configuration. In the figure, p601p indicates a positive lens group, p601n indicates a negative lens group, p602 indicates an image plane, p603 indicates an optical axis, and p604 indicates an image inverting unit. Assuming that the focal length of the positive lens group is f1p and the lateral magnification of the image of the negative lens group p601n is β2, the focal length fobj of the entire objective lens system p600 is fobj = β2 * f1p.

When performing camera shake correction, the second group p601n
The lens diameter is small, so it is easy to shift. Second group p6
When the 01n negative lens group is moved by Δs2 perpendicular to the optical axis p603, the moving distance Δy of the image point is Δy = (1−β2) Δs2 (β2> 1).

In order to increase the movement of the image position ΔY with respect to the movement of the second lens unit, it is necessary to increase the movement amount Δs2 and the magnification β2. Since the deflection amount of the optical path is determined by Δy / fobj, camera shake correction can be realized when the focal length of the objective lens is short. However, when the objective lens has a large aperture and a long focal length, the correction angle of the camera shake is small. It becomes too small to obtain a sufficient camera shake correction effect.

Therefore, it is necessary to increase the absolute value of (1−β2), and the size of the actuator and the like increases.

Therefore, in the present invention, the objective lens system is provided with three lens groups, a first group having a positive refractive power, a second group having a negative refractive power, and a third group having a positive refractive power. Make up. The lateral magnifications of the second and third groups are β2 and β, respectively.
In the case of 3, when the second lens unit is translated by Δs2, the image point shift Δy is Δy = (1−β2) β3Δs2. The total focal length fobj is fobj = β2 × β3 × f1p. Further, even if the focal length of the first group is set to be enlarged by the product of the magnifications β2 and β3, and the entire system is configured as a teletype optical system, by appropriately setting the magnifications β2 and β3, the image The movement can be increased.

Further, regarding the conditional expression ΔS = (1-1 / M) fobj · tan W ‥‥‥ (1), in FIG. When the light exits from the lens at an angle, the rays entering the eye become parallel. In such a case, when the position of the eyes is fixed, complete image stabilization is performed on an image formed on the retina.

At this time, the moving amount Δya of the image is Δya = feye tan W. Therefore, when the correction amount is determined by taking this amount into account, the correction amount Δs is obtained by subtracting this movement amount from the image point, and Δs = fobjtanW−feyetanW = fobj (1-1 / M) tanW.

In the present invention, the following conditional expression is satisfied in order to perform image blur more favorably.

0.5 <f1 / fobj <0.8 ‥‥‥ (2) 0.05 <D12 / fobj <0.5 ‥‥‥ (3) f1: focal length of the first lens group fobj: objective lens The focal length of the entire system D12: Distance between the first and second lens groups If the lower limit of conditional expression (2) is exceeded, the first lens group becomes bright and spherical aberration and the like increase. If the upper limit is exceeded, the overall length will increase.

If the lower limit of conditional expression (3) is exceeded, the first group and the second group are too close to each other, so that the second group becomes large. If the upper limit is exceeded, it becomes difficult to dispose the prism.

In the present invention, the powers of the first, second, and third groups and the paraxial refractive power arrangement are appropriately set by satisfying the respective conditional expressions.

The second group is a lens group movable in a direction perpendicular to the optical axis for image blur correction, and the first group is
It consists of a combination of a positive lens and a negative lens, and satisfies the following conditional expression.

60 <ν1p ‥‥‥ (4) Where, ν1p is the Abbe number of the material of the positive lens in the first group. In order to correct image blur due to camera shake, when the second group is moved, the second group is moved. Even in this case, it is desirable that the aberration be corrected. Therefore, the first group is composed of a positive lens and a negative lens, so that spherical aberration, chromatic aberration, and the like can be corrected well.

In addition, if the distance between the second unit and the third unit is widened, the overall length of the lens is increased and portability is lost, so that D23 <0.1 is set.

Here, D23 is the distance between the second lens group and the third lens group.

[Embodiment 1] Next, specific embodiments of an observation optical system and an observation apparatus according to the present invention will be described below.

FIG. 1 is a schematic diagram of a cross-sectional shape near the objective lens system (objective lens) of the observation optical system according to the first embodiment of the present invention.

In the drawing, reference numeral 101 denotes an objective lens, which is a first group 101a having a positive refractive power, a second group 101b having a negative lens and a positive lens and having a negative refractive power as a whole, and having a positive refractive power. The third lens group 101c has three lens groups. Reference numeral 102 denotes an image plane, and 103 denotes an image reversing means such as a Porro prism or a penta prism. Reference numeral 103 denotes a prism or the like. 104 is an optical axis.

In this embodiment, the second group 101b is moved in the direction orthogonal to the optical axis to correct image blur due to camera shake or the like. Table 1 shows a numerical example of the optical system of the present embodiment.

FIG. 2 shows aberration diagrams of the present embodiment. In FIG. 2, (a), (b), (c), and (d) represent spherical aberration, astigmatism, distortion, and chromatic aberration of magnification, respectively. D, F, and C shown in FIG.
Line F and line C are shown. M and S represent meridional and sagittal image planes. This description is the same in the following embodiments, and the description is omitted.

In this embodiment, since the second unit is moved in the direction perpendicular to the optical axis to perform camera shake correction, the optical performance at the time of camera shake correction is shown in FIGS. In the figure, d is the transverse aberration of the d-line, and the display of other wavelengths is the same as that of FIG.

FIGS. 3A and 3B show lateral aberrations when camera shake correction is not performed. FIG. 3A shows an image height Y = 0, and FIG.
(B) is a case where the image height Y = 3.5.

FIG. 4 is a lateral aberration diagram when the second lens unit is shifted by 0.5 mm. FIGS. 4A, 4B and 4C show image heights Y = 0, 3.5 and -3. 5 is shown.

In the present embodiment, since the image height is up to 7 mm, Y = 3.5-3.5 indicates an image height up to 50%. A description of this point will be omitted.

FIG. 4 shows that the performance is good even at the time of camera shake correction. In particular, in an observation optical system such as a telescope, the resolving power near the center is important, but FIG. 4 also shows that the deterioration of aberration is small.

FIG. 5 is a cross-sectional view in the case where an eyepiece lens 105 is attached to the objective lens system of this embodiment to form an observation optical system.
Through 05, observation is made from the eye point 106.

In this embodiment, the eyepiece lens 105 has a lens structure of four groups and five lenses. However, the present invention is not limited to this, and a Kellner type lens or the like may be used. The focus adjustment in the present embodiment is performed by the objective lens 10.
A part or all of 1 or the eyepiece 102
May be moved, or may be performed by the prism 103, and the method is not particularly limited.

[0068]

[Table 1] Second Embodiment FIG. 6 is a schematic diagram of a cross-sectional shape near an objective lens system of an observation optical system according to a second embodiment of the present invention. In the figure, reference numeral 201 denotes an objective lens, which includes a first group 201a having a positive refractive power and a second group 201 having a negative refractive power.
b, three lens groups of a third group 201c having a positive refractive power. Reference numeral 202 denotes an image plane, and 203 denotes an image reversing unit. Reference numeral 203 denotes a porro prism, a penta prism, or the like. 204 is an optical axis.

In the present embodiment, the second group 201b is moved in a direction orthogonal to the optical axis to correct image blur due to camera shake or the like.

Table 2 shows numerical values of the optical system according to the present embodiment. In the present embodiment, a cover glass PG is employed before the positive lens group 201a.

FIG. 7 shows aberration diagrams of the present embodiment.

In this embodiment, since the second group is moved in the direction perpendicular to the optical axis to perform camera shake correction, the optical performance at the time of camera shake correction is shown in FIGS. FIG. 8 shows lateral aberration when camera shake correction is not performed.
(A) shows the case where the image height Y = 0, and (b) shows the case where the image height Y = 3.5.

FIG. 9 is a lateral aberration diagram when the second lens unit is shifted by 0.5 mm. FIGS. 9A, 9B, and 9C show Y = 0, 3.5, and -3.5, respectively. Shows the case. From the above, it can be seen that the performance is good even at the time of camera shake correction.

FIG. 10 shows the objective lens system 201 of this embodiment.
FIG. 2 is a cross-sectional view when an eyepiece lens 205 is attached to an observation optical system.

[0075]

[Table 2] Third Embodiment FIG. 11 is a schematic diagram of a cross-sectional shape near an objective lens system of an observation optical system according to a third embodiment of the present invention.

In the figure, reference numeral 301 denotes an objective lens, which includes three lens groups, a first group 301a having a positive refractive power, a second group 301b having a negative refractive power, and a third group 301c having a positive refractive power. Have. Reference numeral 302 denotes an image plane, and 303 denotes an image inversion unit. Reference numeral 303 denotes a prism or the like. In the drawing, the optical path is developed and described by a glass block. 304 is an optical axis.

In this embodiment, the second group 301b is moved in a direction perpendicular to the optical axis to correct image blur due to camera shake or the like.

Table 3 shows numerical values of the optical system according to the present embodiment. FIG. 12 shows an aberration diagram of the present embodiment.

In this embodiment, since the second group is moved in the direction perpendicular to the optical axis to perform camera shake correction, the optical performance at the time of camera shake correction is shown in FIGS. FIGS. 13A and 13B show lateral aberrations when camera shake correction is not performed. FIG. 13A shows a case where the image height Y = 0, and FIG. 13B shows a case where the image height Y = 3.5.

FIG. 14 is a lateral aberration diagram when the second lens unit is shifted by 0.5 mm, and (a), (b), and (c) show Y = 0, 3.5, and -3.5, respectively. Shows the case.

As described above, even when camera shake correction is not performed,
It can be seen that the performance is good even when the second group is not moved.

The case where an eyepiece is attached to the objective lens system of the present embodiment to form an observation optical system is the same as that of the second embodiment, so that the illustration is omitted.

[0083]

[Table 3] Fourth Embodiment FIG. 15 is a schematic diagram of a cross-sectional shape near an objective lens system of an observation optical system according to a fourth embodiment of the present invention. In the figure, reference numeral 401 denotes an objective lens, a first group 401a having a positive refractive power, and a second group 401 having a negative refractive power.
b, three lens groups of a third group 401c having a positive refractive power. Reference numeral 402 denotes an image plane, and 403 denotes an image inversion unit. Reference numeral 403 denotes a prism or the like. In the figure, the optical path is developed and described by a glass block. 404 is an optical axis. Table 4 shows numerical values of the optical system of the present embodiment.

FIG. 16 is an aberration diagram for this embodiment. In the present embodiment, since the second group is moved in the direction perpendicular to the optical axis to perform camera shake correction, the optical performance at the time of camera shake correction is shown in FIGS. FIG. 17 shows lateral aberrations when camera shake correction is not performed.
Represents the case where the image height Y = 0, and (b) represents the case where the image height Y = 3.5.

FIG. 18 is a lateral aberration diagram when the second lens unit is shifted by 0.5 mm, and (a), (b), and (c) show Y = 0, 3.5, and -3.5, respectively. Shows the case.

From the above, it can be seen that the performance is good even at the time of camera shake correction. FIG. 19 shows the objective lens system 4 of this embodiment.
FIG. 3 is a cross-sectional view when an eyepiece lens 405 is attached to an observation optical system 01, and an image formed on an image plane 402 in the figure is observed through an eyepiece 405 from an eye point 406.

In the present embodiment, the fourth group and the fifth group are used as eyepieces.
Although a lens structure having a single lens is shown, the present invention is not limited to this, and a lens having a Kellner type or the like may be used.

[0088]

[Table 4] Fifth Embodiment FIG. 20 is a schematic diagram of a cross-sectional shape near an objective lens system of an observation optical system according to a fifth embodiment of the present invention. In the figure, reference numeral 501 denotes an objective lens, which includes a first group 501a having a positive refractive power and a second group 501 having a negative refractive power.
b, a third lens unit 501c having a positive refractive power. Reference numeral 502 denotes an image plane, and 503 denotes an image inversion unit. Reference numeral 503 denotes a prism or the like. In the drawing, the optical path is developed and described by a glass block. 504 is an optical axis. Table 5 shows numerical values of the optical system of the present embodiment.

FIG. 21 shows aberration diagrams of the present embodiment. In the present embodiment, since the second group is moved in the direction perpendicular to the optical axis to perform camera shake correction, the optical performance at the time of camera shake correction is shown in FIGS. FIG. 22 shows lateral aberrations when camera shake correction is not performed.
(A) shows the case where the image height Y = 0, and (b) shows the case where the image height Y = 3.5.

FIG. 23 is a lateral aberration diagram when the second lens unit is shifted by 0.5 mm, and (a), (b), and (c) show the case where Y = 0, 3.5, and -3.5, respectively. Shows the case. From the above, it can be seen that the performance is good even at the time of camera shake correction.

The case where the observation optical system is configured in the present embodiment is the same as in the fourth embodiment, and a description thereof will be omitted.

[0092]

[Table 5] In the first to fifth embodiments of the invention, the optical path of the image reversing means is shown in a developed form, but is actually constituted by a Porro prism, a roof prism and the like. The shape and material of the prism are not particularly limited.

In the first to fifth embodiments, if the camera shake is corrected so as to satisfy the conditional expression (1), the camera shake is corrected for the eyes. If the conditional expression (1) is not completely satisfied, the camera shake correction will be left uncorrected by that amount. However, it is possible to reduce the deterioration of the optical performance due to the camera shake, so that the conditional expression (1) may be approximately satisfied. .

In the present embodiment, the second group is shifted to perform the shift stabilization. However, the first group and the third group can also perform the shift stabilization in principle. By shifting the second group, the amount of deflection with respect to the amount of movement can be increased.

FIG. 24 is a schematic view of a main part of an observation apparatus using the observation optical system of FIG. 5 of the present invention. FIG. 24 is Embodiment 1
The observation optical system in 5 can be applied. 24 deflects the optical path in the objective lens. The optical path deflecting means has a lens driving circuit for driving the second lens group and a lens driving mechanism therefor.

The observation device has a shake detecting means for detecting the shake, a control means for controlling the shake and the like. In this case, known configurations can be applied to the configuration of the driving circuit, the driving mechanism, the control circuit, and the like, and there is no particular limitation.

[0097]

As described above, according to the present invention, in an observation optical system for observing an object image formed by an objective lens as an erect image with an eyepiece using an image inverting means such as an erect prism, An observation optical system and an observation apparatus using the same that can appropriately correct image blur due to camera shake by appropriately setting a shift image stabilizing mechanism that moves a part of the lens group in a direction perpendicular to the optical axis. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an objective lens system of an observation optical system according to a first embodiment of the present invention.

FIG. 2 is an aberration diagram according to the first embodiment of the present invention.

FIG. 3 is a lateral aberration diagram of Embodiment 1 of the present invention in a state without camera shake.

FIG. 4 is a lateral aberration diagram at the time of camera shake correction according to the first embodiment of the present invention.

FIG. 5 is a sectional view of an observation optical system according to the first embodiment of the present invention.

FIG. 6 is a sectional view of an objective lens system of an observation optical system according to a second embodiment of the present invention.

FIG. 7 is an aberration diagram according to the second embodiment of the present invention.

FIG. 8 is a lateral aberration diagram in the state without camera shake according to the second embodiment of the present invention.

FIG. 9 is a lateral aberration diagram at the time of camera shake correction according to the second embodiment of the present invention.

FIG. 10 is a sectional view of an observation optical system according to a second embodiment of the present invention.

FIG. 11 is a sectional view of an objective lens system of an observation optical system according to a third embodiment of the present invention.

FIG. 12 is an aberration diagram according to Embodiment 3 of the present invention.

FIG. 13 is a lateral aberration diagram of Embodiment 3 of the present invention in a state without camera shake.

FIG. 14 is a lateral aberration diagram at the time of camera shake correction according to the third embodiment of the present invention.

FIG. 15 is a sectional view of an objective lens system of an observation optical system according to a fourth embodiment of the present invention.

FIG. 16 is an aberration diagram according to the fourth embodiment of the present invention.

FIG. 17 is a lateral aberration diagram of Embodiment 4 of the present invention in a state without camera shake.

FIG. 18 is a lateral aberration diagram at the time of camera shake correction according to the fourth embodiment of the present invention.

FIG. 19 is a sectional view of an observation optical system according to a fourth embodiment of the present invention.

FIG. 20 is a sectional view of an objective lens system of an observation optical system according to a fifth embodiment of the present invention.

FIG. 21 is an aberration diagram according to the fifth embodiment of the present invention.

FIG. 22 is a lateral aberration diagram of Embodiment 5 of the present invention in a state without camera shake.

FIG. 23 is a lateral aberration diagram at the time of camera shake correction according to the fifth embodiment of the present invention.

FIG. 24 is a schematic view of a main part of the observation device of the present invention.

FIG. 25 is a schematic view of a main part of an observation optical system having a conventional image blur correction mechanism.

FIG. 26 is a schematic view of a main part of an observation optical system having a conventional image blur correction mechanism.

FIG. 27 is an explanatory diagram of an image blur correction mechanism.

FIG. 28 is an explanatory diagram of an image blur correction mechanism.

FIG. 29 is an explanatory diagram of an objective lens system according to the present invention.

FIG. 30 is an explanatory diagram of an objective lens system according to the present invention.

[Explanation of symbols]

 P101 Objective lens P102 Variable vertex prism P103 Image inverting means P104 Eyepiece P201 Lens P202 Image plane P203 Optical axis P204 Light ray from object P301 Objective lens P302 Image plane P303 Optical axis P304 Light ray from object P305 Eyepiece P306 Eye of observer P401 Anti-vibration system P402 Image plane L Optical axis P501 Objective lens P502 Image plane P503 Optical axis P504 Image reversing means P601 Objective lens P602 Image plane P603 Optical axis P604 Image reversing means i01 Objective lens i01a First lens group i01b Second lens group i01c Third lens group i02 Image plane i04 Optical axis i05 Eyepiece i06 Eye point

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Kenji Miyauchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Haruhiko Yamauchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon F term in the company (reference) 2H039 AA01 AA05 AB14 AB22 AB32 2H087 KA15 KA16 LA02 LA12 NA07 PA03 PA04 PA05 PA18 PA19 PA20 PB05 PB06 PB07 QA02 QA03 QA06 QA07 QA14 QA19 QA21 QA22 QA26 QA32 QA42 QA41 QA32

Claims (11)

[Claims] 1. An observation optical system for observing an object image formed by an objective lens as an erect image via an image inverting means and using an eyepiece lens, wherein the objective lens has a first refractive power having a positive refractive power in order from the object side. A second lens group having a negative refractive power
It has three lens groups, a lens group and a third lens group having a positive refracting power. The amount of change ΔS in the position of an object image formed by the objective lens when the observation optical system is tilted by W is represented by When correcting by moving at least one lens group constituting the objective lens in a direction perpendicular to the optical axis, when the focal length of the objective lens is fobj and the magnification of the observation optical system is M, ΔS = (1− 1 / M) An observation optical system satisfying fobj · tan W. 2. When the focal length of the first lens group of the objective lens is f1, and the distance between the first lens group and the second lens group is D12, 0.5 <f1 / fobj <0.8. 2. The observation optical system according to claim 1, wherein the following condition is satisfied: 05 <D12 / fobj <0.5. 3. The method according to claim 1, wherein the second lens group of the objective lens is moved in a direction perpendicular to an optical axis to correct image blur.
3. The observation optical system according to claim 2, wherein the lens group has a positive lens and a negative lens, and satisfies 60 <ν1p when the Abbe number of the material of the positive lens is ν1p. 4. In an observation optical system for observing an object image formed by an objective lens as an erect image via an image inverting means and using an eyepiece, an object image formed by the objective lens is located on an exit surface side of the inverting means. , And the objective lens includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power.
The objective lens has three lens groups, and a change in the position of an object image formed by the objective lens that occurs when the observation optical system is tilted is determined by using at least one lens group that constitutes the objective lens as an optical axis. An observation optical system characterized in that correction is performed by moving in a vertical direction. 5. When the focal length of the first lens group of the objective lens is f1, and the distance between the first lens group and the second lens group is D12, 0.5 <f1 / fobj <0.8. 5. The observation optical system according to claim 4, wherein the following condition is satisfied: 05 <D12 / fobj <0.5. 6. The method according to claim 1, wherein the second lens group of the objective lens is moved in a direction perpendicular to an optical axis to correct image blur.
6. The observation optical system according to claim 5, wherein the lens group has a positive lens and a negative lens, and satisfies 60 <ν1p when the Abbe number of the material of the positive lens is ν1p. 7. An observation optical system for observing an object image formed by an objective lens as an erect erect image via an image inverting unit with an eyepiece, a blur detection unit for detecting a blur amount of the observation optical system, and An optical path deflecting unit for deflecting an optical path in the objective lens based on a signal from the shake detecting unit and correcting image blur, wherein the optical path changing unit is a part of the objective lens. An observation apparatus comprising a lens driving mechanism for moving one or all of the lenses in a direction perpendicular to the optical axis. 8. The observation apparatus according to claim 7, wherein the objective lens has a first lens group having a fixed positive refractive power and a plurality of lens groups following the first lens group when correcting blur. 9. The objective lens includes a first lens unit having a positive refractive power and a second lens unit having a negative refractive power in order from the object side.
It has three lens groups, a lens group and a third lens group having a positive refractive power. By moving the second lens group in a direction perpendicular to the optical axis, image blur when the observation optical system is tilted can be reduced. 9. The observation device according to claim 8, wherein the correction is performed. 10. The focal length of the objective lens is fobj,
The focal length of the first lens group of the objective lens is f1, the first lens group is
10. The observation according to claim 9, wherein when the distance between the lens group and the second lens group is D12, the following condition is satisfied: 0.5 <f1 / fobj <0.8 0.05 <D12 / fobj <0.5. apparatus. 11. The first lens group has a positive lens and a negative lens, and the Abbe number of the material of the positive lens is ν1.
The observation device according to claim 10, wherein 60 <ν1p is satisfied when p is satisfied.