JP2002182125A - Binocular lens barrel - Google Patents

Abstract

(57) [Problem] To provide a binocular lens barrel for simultaneously moving lens groups in left and right objective optical systems without decentering. The zoom optical systems are housed in a common zoom lens barrel. This zoom lens barrel 2
Is a fixed ring 3 having a linear groove 3e formed therein and holding the first lens groups 221 and 231 and the fourth lens groups 224 and 234 of the zoom optical systems 220 and 230; Freely loaded and 2
A cam ring 4 having system cam grooves 4a and 4b formed therein;
The second lens frame 5 and the third lens frame 6 holding both the second lens groups 222 and 232 or the third lens groups 223 and 233 of the lenses 20 and 230 and the outer peripheral surfaces of the respective lens frames 5 and 6 And a cam follower 10 inserted into the intersection of the fixed ring 3 and one of the cam grooves 4a, 4b.
11 and a tension spring 14 that is hung obliquely with respect to the axis of the cam ring 4 between the two lens frames 5 and 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a binocular lens barrel for holding a moving lens group in a pair of objective optical systems arranged at a predetermined base line distance.

[0002]

2. Description of the Related Art An objective optical system of this kind is used as a part of a binocular optical system such as a binocular, a binocular microscope, and a stereo camera.

When a focusing lens for focus adjustment or a variable power lens for zooming is incorporated in these pair of objective optical systems, it is necessary to make these lenses movable along the optical axis. It becomes necessary to house the optical system in a lens barrel composed of a lens moving frame, a cam ring, and a fixed ring, respectively. For such a reason, the applicant of the present invention has previously disclosed an example in which a pair of objective optical systems (zoom optical systems) are housed in lens barrels (zoom barrels) having the same configuration.
No. 150832. This Japanese Patent Application No. 11-
FIGS. 22 and 23 show a configuration in which the invention according to No. 150832 is further embodied.

[0004] The configuration shown in these figures is basically
A pair of zoom lens barrels 401, 401 are fixed in a state penetrating a frame 400 fixed inside a casing (not shown), and a cam ring 40 inside each zoom lens barrel 401, 401 is fixed.
Gears 402a, 402a formed at the tips of
On the other hand, a common cam ring drive gear 404 rotatably supported by the frame 400 meshes with each other, and a pinion 405 rotationally driven by a motor 403 embedded in the frame 400 is attached to the cam ring drive gear 404. It has become meshed. With such a configuration, when the motor 403 rotates the pinion 405 in any rotational direction, the pinion 405 is rotated by the cam ring drive gear 404.
, Cam rings 402 of both zoom lens barrels 401, 401,
Since both the zoom lens barrels 402 are simultaneously driven to rotate,
In 1,401, moving lenses (magnifying lens and compensator lens) 407, 408 move synchronously on the left and right. As a result, the image stereoscopically viewed based on the left and right images finally formed via these objective optical systems is enlarged or reduced.

[0005]

However, as described above, according to the configuration in which the cam rings 402, 402 of the left and right zoom lens barrels 401, 401 are simultaneously engaged with the common cam ring drive gear 404, this cam ring drive Due to the rotation of the gear 404 in one direction, torques in opposite directions about the cam ring drive gear 404 are applied to one ends of the left and right zoom lens barrels 401, 401. As a result, as shown in FIG. 24, the left and right zoom lens barrels 401 and 401 are tilted in directions opposite to each other with the cam ring drive gear 404 as a center. Are relatively shifted up and down, and natural stereoscopic vision is hindered. Moreover, when the zooming direction is reversed (when the rotation direction of the cam ring drive gear 404 is reversed), the directions in which the zoom lens barrels 401 and 401 are tilted change to the opposite directions. Are reversed, and as a result, the left and right images relatively move by twice the amount of the displacement.

Each of the zoom lens barrels 401 and 401 has a cam ring 411 implanted on the outer peripheral surface of lens frames 409 and 410 for holding lenses 407 and 408, similarly to a general lens barrel. Straight groove and cam ring 4
02 is inserted into the intersection with the cam groove formed in the cam ring 402, and the cam ring 402 rotates with respect to the fixed ring 412,
A configuration is provided in which the lens frames 409 and 410 move in the optical axis direction as the intersection of both grooves moves. Therefore, a problem of backlash arises because the cam pin 411 is narrower than the width of both grooves. In this case, the lens frames 409, 410
Can be prevented in any direction in the optical axis direction to prevent backlash, but the cam groove is oriented in a direction perpendicular to the optical axis (that is, the circumferential direction of the cam ring 402). Since the position of the cam pin 411 cannot be unambiguously determined at a certain position, the lens frames 409 and 410 can rotate with respect to the fixed ring 412 within the range of the clearance between the straight groove and the cam pin 411. When the lens frames 409 and 410 rotate in this manner, the lenses 407 and 4 are rotated with respect to the rotation center of the lens frames 409 and 410.
If the optical axis 08 is decentered, the left and right images also move relatively.

[0007] These problems can also occur in a configuration in which the focusing lens in each objective optical system is moved by a pair of right and left lens barrels.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a configuration in which a part of lens groups constituting a pair of right and left objective optical systems is moved in synchronization with each other. Regardless, it is an object of the present invention to provide a binocular lens barrel in which the lens groups are not decentered during the movement, and therefore, the finally formed left and right images do not relatively move.

[0009]

In order to achieve the above-mentioned object, a binocular lens barrel according to the present invention comprises a pair of objective optical systems for forming images of the same object from positions separated by a predetermined base line length. A binocular lens barrel for holding a moving lens group therein, comprising a cylindrical member having a central axis parallel to the optical axis of each of the objective optical systems, and having a rectilinear groove parallel to the central axis. A cam groove having a stationary ring and a cylindrical member having a central axis parallel to the optical axis, the cam groove having a portion inclined only with respect to the central axis and being rotatably fitted to the stationary ring is formed. A cam ring, a lens frame held inside the fixed ring and the cam ring so as to be movable only in a direction parallel to the optical axis, and holding both moving lens groups in the two objective optical systems. Attached to the lens frame A cam follower that penetrates the intersection of the straight groove and the cam groove; and a biasing member that biases the lens frame in a direction oblique to the optical axes of the objective optical systems. And

With this configuration, the cam follower of the lens frame urged in the twisting direction in the fixed ring and the cam ring by the urging member always has one side of the cam groove regardless of the shape of the cam groove. And at the same time contact one inner edge of the fixing groove. Therefore, regardless of the rotational position of the cam ring and the rotational direction of the cam ring, the position of the lens frame, that is, the moving lens group is uniquely determined in accordance with the rotational position of the cam ring, so that the backlash Does not occur, and eccentricity due to the rotation of the moving lens does not occur. Further, since the moving lens groups of both objective optical systems are held by the same lens frame and driven by the rotation of the same cam ring, both objective optical systems are the same even if the cam ring is inclined by the driving torque. The eccentricity in the direction does not cause the relative movement of the left and right images.

In the present invention, the moving lens group may be a focusing lens, a variable power lens or a compensator lens, that is, a lens group which is simultaneously moved by the same amount on the left and right sides. Are all targeted. Either of the cam ring and the fixed ring may be inside as long as they fit each other. In this case, the groove formed on the inner side must be a through groove, but the groove formed on the outer side is a through groove even if it is a bottomed groove drilled from the inside. Is also good. The rectilinear groove, the cam groove and the cam follower may be only one set as long as the lens frame is guided in the optical axis direction without play. However, if a plurality of sets surround the center of the lens frame, eccentricity of the lens group is prevented. Preferred above. In particular, it is desirable to be provided at equal angular intervals in the circumferential direction of the fixed ring and the cam ring.

The urging member may be a spring or rubber. When the lens frame is urged by utilizing the contraction force of the member, the positions at which both ends are attached are adjusted. Thus, the biasing direction can be inclined with respect to the optical axis. For example, one end may be fixed to the lens frame and the other end may be fixed to the fixed frame. When there are a plurality of lens frames, the rotation of these lens frames is regulated by the rectilinear grooves. Further, the number of the urging members may be only one, or may be plural.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

[0014]

[Embodiment 1] A stereoscopic microscope according to a first embodiment described below is of a video type, and is used, for example, by being incorporated into an operation support system used in neurosurgery. This surgery support system combines a stereoscopic image (stereo image) obtained by video-taking a patient's tissue with a stereoscopic microscope with a CG (computer graphic) image created based on data of an affected part obtained in advance. This is a system for displaying on a stereoscopic viewer dedicated to a surgeon, a monitor for other staff, or the like, and recording on a recording device.

(Overall Configuration of Surgery Support System) FIG.
It is a system configuration diagram showing an outline of this surgery support system. As shown in FIG. 1, the surgery support system
A stereo microscope 101 and a high-vision CCD camera 10 attached near the upper end of the back of the stereo microscope 101
2, a counterweight 104 attached to the upper surface of the stereo microscope 101, and the counterweight 104
A light guide fiber bundle 105 penetrated through the through-hole opened in the stereoscopic microscope 101 and
A light source device 106 for introducing illumination light to the stereo microscope 101 through the light guide fiber bundle 105 and a distributor 11 connected to the high-vision CCD camera 102
1 and the recording devices 115 connected to the distributor 111,
It comprises a monitor 114, a stereoscopic viewer 113, and the like.

The above-mentioned stereo microscope 101 is detachably fixed to the tip of the free arm 100a of the first stand 100 via a mount mounted on the back surface. Therefore, the stereoscopic microscope 101 is provided with the first stand 1
The free arm 100a can move freely and can face any direction within the radius that the free arm 100a can reach. However, here, for convenience, the direction of the subject with respect to the stereo microscope 101 is defined as “down”, and the opposite direction is “up”.
Shall be defined as

The optical configuration of the stereo microscope 101 will be described in detail later.
The object to be observed is a CCD 11 in the high-vision CCD camera 102 by a pair of left and right zoom optical systems and a relay optical system that converge light transmitted through different portions in a large-diameter close-up optical system having a single optical axis.
6 is formed.

With such a pair of photographing optical systems, CC
Left and right imaging regions on the imaging surface of D116 (two regions divided in the direction of the base line length on the imaging surface)
Is equivalent to a stereo image in which images respectively taken from two locations separated by a predetermined base line length are arranged on the left and right. The output signal of the CCD 116 is generated as a Hi-Vision signal by the image processor 117, and is output from the Hi-Vision CCD camera 102 to the distributor 111.
Output to. Note that the stereoscopic microscope 101 has a built-in illumination optical system 300 (see FIG. 3) for illuminating the observation object. The illumination optical system 300
, Illumination light is introduced from the light source device 106 via the light guide fiber bundle 105.

The high-vision signal output from the high-vision CCD camera 102 is distributed by a distributor 111 to a stereoscopic viewer 113 for the main operator D, a monitor 114 for other operation staff or an advisor at a remote location,
Then, they are supplied to the recording device 115, respectively.

The stereoscopic viewer 113 includes the second stand 1
Twelve free arms 112a are attached by hanging from the tips. Therefore, it is possible to arrange the stereoscopic viewer 113 according to a posture in which the main operator D can easily perform the treatment. As shown in FIG. 2, the stereoscopic viewer 113 includes a high-definition LCD panel 120.
Is built in as a monitor. This LCD panel 1
When an image based on a high-definition signal from the distributor is displayed on the area 20, the CCD 1 is located in the left area 120b.
The video captured in the left capturing area in 16 is displayed, and the video captured in the right capturing area in the CCD 116 is displayed in the right area 120a. Therefore, through a pair of left and right loupes provided for each of the left and right regions 120a and 120b, the main operator D can display the left and right images displayed in the left and right regions 120a and 120b with both eyes. , It is possible to stereoscopically view an enlarged image of the observation target.

(Configuration of Stereo Microscope) Next, the specific configuration of the above-described stereo microscope 101 (including the high-vision CCD camera 102) will be described in detail.

<Optical Configuration> FIG. 3 is a perspective view showing the optical system of the stereo microscope 101.

As shown in FIG. 3, an optical system in the stereo microscope 101 is a photographing optical system 2 for electronically photographing an image of a subject.
The illumination optical system 300 illuminates a subject with illumination light guided from the light source device 106 by the light guide fiber bundle 105.

As described above, the photographing optical system 200 has a single close-up optical system 210 shared by the left and right, and a pair of left and right objective optical systems composed of a pair of left and right zoom optical systems 220 and 230 as described above. And a pair of left and right relay optical systems 240 and 25 for relaying a primary image of the subject formed by the objective optical system and forming a secondary image of the subject.
0, and a converging prism 260 as an inter-optical axis distance reducing element for bringing the subject light from these relay optical systems 240 and 250 closer to each other.

Field stops 270 and 271 are arranged at positions where the primary optical images are formed by the zoom optical systems 220 and 230, respectively.
Inside, a pentaprism 272 that deflects the optical path at right angles,
273 are respectively arranged.

With such a configuration, the CCD camera 10
The left and right subject images having a predetermined parallax can be formed in two adjacent regions on the CCD 116 arranged in the second CCD 2. In the description of the optical system, “left and right” is C
When projected onto the CD 116, the direction coincides with the longitudinal direction of the imaging surface, and “up / down” refers to the direction orthogonal to the left / right direction on the CCD 116. Hereinafter, the configuration of each optical system will be described in order.

The close-up optical system 210 is configured by arranging a first negative lens 211 and a second positive lens 212 in order from the object side. Second lens 21
Reference numeral 2 is movable in the optical axis direction, and can adjust the movement to focus on objects at different distances. That is, since the close-up optical system 210 adjusts the second lens 212 so that the main subject (observation target) is located at the object side focal position, the divergent light from the main subject (observation target) is substantially reduced. It has a collimating function for converting into parallel light.

The first and second lenses 211 and 212 constituting the close-up optical system 210 themselves extend along a plane passing through a position slightly deviated outward from the optical axis in parallel with the optical axis, and The outer edge is cut off. Therefore, when viewed from the direction of the optical axis, each of the planar shapes has a D-cut shape, so that there is a space beside the cutout surface. In this space, the illumination optical system 300 is arranged with its optical axis Ax4 parallel to the optical axis Ax1 of the close-up optical system 210.

The pair of zoom optical systems 220 and 230 function as image forming optical systems for forming subject light from the close-up optical system 210 at infinity at the positions of the field stops 270 and 271 respectively.

One zoom optical system 220 has first to fourth lens groups 221, 222, 222 having positive, negative, negative, and positive power, respectively, in order from the close-up optical system 210.
223, 224, and the first and fourth lens groups 2
21 and 224 are fixed, and the second and third lens groups 222 and 2 are fixed.
23 is moved in the optical axis direction to perform zooming. mainly,
The magnification is changed by moving the second lens group 222 that is a variable power lens, and the focal position is kept constant by moving the third lens group 223 that is a compensator lens.

The other zoom optical system 230 has the same configuration as the above-described zoom optical system 220, and includes first to fourth lens groups 231, 232, 233, and 234. These zoom optical systems 220 and 230 are linked by a zoom lens barrel 2 described later, and can simultaneously change the photographing magnification of the left and right images.

Optical axes Ax of zoom optical systems 220 and 230
2, Ax3 is the optical axis Ax of the close-up optical system 210
1 and are offset in parallel to 1. However, the optical axes Ax2 and Ax3 of the zoom optical systems 220 and 230
Are offset from each other with respect to the optical axis Ax1 of the close-up optical system 210 at positions where they are equidistant from each other and equal in distance from the notch plane. When viewed from the direction of the optical axis Ax1 of the close-up optical system 210, the optical axis Ax1 of the close-up optical system 210 and the optical axes Ax2 and Ax3 of both zoom optical systems 220 and 230 form an obtuse angle at the position of the optical axis Ax1. They are arranged to form an isosceles triangle with vertices.

The diameter of the close-up optical system 210 is set to be larger than the diameter of a circle containing the maximum effective diameter of the zoom optical systems 220 and 230 and the maximum effective diameter of the illumination optical system 300. Therefore, both zoom optical systems 220 and 23
The 0 optical axes are deflected by the close-up optical system 210 and cross each other at the object-side focal position of the close-up optical system 210. As a result, both zoom optical systems 2
At the image-side focal positions 20 and 230, images equivalent to those obtained by imaging the same object from two positions separated by a predetermined base line length are respectively formed.

The field stops 270 and 271 are arranged at positions that are planned as image forming positions of the primary images by the zoom optical systems 220 and 230 created according to the design values. The field stop 270, 271 has a circular outer shape and a semicircular opening inside each of the left and right directions. Each field stop 27
0,271 indicates that the linear edge of this opening is the CCD 11
6 are arranged so as to correspond to the direction corresponding to the boundary line between the left and right images and transmit only the light flux inside the same.

The relay optical systems 240 and 250 have the function of re-forming the primary image formed by the zoom optical systems 220 and 230 as described above, and each is constituted by three positive lens groups.

One relay optical system 240 includes a first lens group 241 composed of a single positive meniscus lens,
The second lens group 242 is composed of negative and positive lenses and has a positive power as a whole, and the third lens group 243 includes a single biconvex lens. The first lens group 241 and the second lens group 242 have the object-side focal point as a whole fixed at the image forming plane of the primary image by the zoom optical system 220 (the same plane as the field stop 271). The third lens group 243 causes the parallel light emitted from the second lens group 242 to converge on the imaging surface of the CCD 116. A pentaprism 272 for deflecting the optical path at right angles is disposed between the first lens group 241 and the second lens group 242, and a light amount adjustment is provided between the second lens group 242 and the third lens group 243. Aperture 244 for
Is provided.

The other relay optical system 250 has the same configuration as the above-mentioned relay optical system 240, and is composed of first, second, and third lens groups 251, 252, and 253. A pentaprism 273 is disposed between the second lens group 252 and the lens group 252, and a brightness stop 254 is provided between the second lens group 252 and the third lens group 253.

The divergent light that has passed through the field stops 270 and 271 is again converted into substantially parallel light by the first lens groups 241 and 251 and the second lens groups 242 and 252 of the relay optical system. After passing through, the light is converged again by the third lens groups 243 and 253 to form a secondary image.

A convergence shifting prism 260 disposed between the relay optical systems 240 and 250 and the CCD camera 102
Has a function of narrowing the left and right intervals of subject light from the respective relay optical systems 240 and 250. In order to obtain a stereoscopic effect by stereoscopic vision, left and right zoom optical systems 220 and 23 are used.
0, a predetermined base line length is required between the relay optical systems 240 and 250. On the other hand, in order to form a secondary image in an adjacent area on the CCD 116, the distance between the optical axes needs to be smaller than the base length. Therefore, the congestion approaching prism 260
By shifting the optical axis of the relay optical system inward, the same CCD can be maintained while maintaining a predetermined base line length.
It is possible to form an image on the image 116.

The convergence shifting prism 260 is configured by joining symmetrical optical axis shift prisms 261 and 262 of a pentagonal prism (with a predetermined gap).
Each of the optical axis shift prisms 261 and 262 has an incident end face and an exit end face that are parallel to each other, and has first and second reflective surfaces that are parallel to each other inside and outside. When viewed in a plane perpendicular to the entrance and exit end faces and the reflection surface, these optical axis shift prisms 261 and 262 form one of the acute apex angles of the parallelogram as a line perpendicular to the exit end face. It is a pentagonal shape formed by cutting out the surface, and the surface formed by cutting out is a joining surface.

The subject light from the relay optical systems 240 and 250 enters from the incident end faces of the optical axis shift prisms 261 and 262, is reflected by the outer reflecting surface, is directed inward in the left and right direction, and is directed to the inner reflecting surface. Is reflected again in the same optical axis direction as at the time of incidence, exits from the exit end face, and is
Incident on. As a result, the left and right object lights are narrowed only in the left and right intervals without changing their traveling directions, and the same CCD 1
16 to form a secondary image.

The illumination optical system 300 has a function of irradiating the object with illumination light.
5 includes an illumination lens 310 for adjusting the degree of divergence of the divergent light emitted from the lens 5 and a wedge prism 320 for matching the illumination range and the photographing range. Lighting lens 3
Since the optical axis Ax4 of No. 10 is parallel to the optical axis Ax1 of the close-up optical system 210 and is decentered by a predetermined amount, the center of the illumination range does not coincide with the center of the photographing range as it is, and the illumination light amount To waste. By providing the wedge prism 310, the above mismatch can be eliminated, and the amount of illumination light can be used effectively.

<Optical System Holding Mechanism> Next, a pair of left and right zoom optical systems 220 and 23 of the above-described photographing optical system 200 are described.
The mechanical configuration of a mechanism that holds the “0” in the housing 1 of the stereoscopic microscope 101 will be described. FIG. 5 shows each of the zoom optical systems 220 and 2.
FIG. 2 is a schematic longitudinal sectional view (part) of the stereoscopic microscope 101 along a plane including both the 30 optical axes Ax2 and Ax3. 4 is a schematic cross-sectional view along IV-IV in FIG. 5, and FIG. 6 is a schematic vertical cross-sectional view along line VI-VI in FIG. As shown in these figures, both zoom optical systems 220 and 230 are held by a common zoom lens barrel 2. The zoom lens barrel 2 includes a cylindrical fixed ring 3 fixed inside the housing 1, a cam ring 4 fitted into the fixed ring 3 so as to be rotatable only, and a straight running inside the cam ring 4. The two lens frames (the second lens frame 5 and the third lens frame 6) that are fitted as possible are the main components.

The fixed ring 3 has a substantially cylindrical shape with a bottom. The bottom 3a has a circular through-hole 3b centered on the passing position of the optical axes Ax1 and Ax2 of the zoom optical systems 220 and 230. , 3c are formed. Further, an illumination hole 3d is formed which substantially overlaps the D-cut portion (substantially half-moon-shaped portion) of each of the lenses 211 and 212 constituting the close-up optical system 210. And both through holes 3b,
At the lower edge of 3c, first lens frames 7, 7 each having a cylindrical shape having substantially the same inner diameter and holding the first lens groups 221 and 231 are fixed, respectively.

Further, three places at equal angular intervals in the circumferential direction of the fixed ring 3 (a plane including both optical axes Ax2 and Ax3 are equally divided into two parts, and a plane orthogonal to the fixed ring 3 is located on the side distant from the illumination hole 3d). 3
, And two locations which are shifted from each other by 120 degrees in the circumferential direction), linear through grooves (straight grooves) 3e, 3e, 3e parallel to the central axis of the fixed ring 3 are formed, respectively. ing.

The upper side of the stationary ring 3 (relay optical system side)
A disk-shaped lid 8 is fitted into the open end of the disk. Each of the through holes 3 b and 3 c of the fixed ring 3 and the illumination
Corresponding to d respectively, there are formed through holes 8b and 8c centered on the passing position of both optical axes Ax2 and Ax3 and an illumination hole 8d having the same shape and the same position as the illumination hole 3d. Each of the zoom optical systems 220 and 230 is provided in each of the through holes 8b and 8c.
The fourth lens frames 9, 9 holding the fourth lens groups 224, 234 therein are fixed in a penetrating state.

The cam ring 4 has the same length in the axial direction as the distance from the bottom 3a of the fixed ring 3 to the lid 8. Therefore, the cam ring 4 is held in the fixed ring 3 without play. This fixed ring 3 is provided at equal angular intervals of 120 degrees,
A pair of cam grooves for driving the two lens frames 5 and 6 (a first cam groove 4a for driving the second lens frame 5 and a second cam groove 4b for driving the third lens frame 6) ) Is formed through. The positions of the respective ends of the two cam grooves 4a and 4b coincide with each other in the circumferential direction. The area occupied by the cam grooves 4a and 4b coincides with the area occupied by the straight groove 3e in the axial direction.

Each of the lens frames 5 and 6 has a flat bottomed cylindrical shape having an outer diameter substantially equal to the inner diameter of the cam ring 4. The second lens frame 5 is fitted into the cam ring 4 with its open end facing upward (toward the relay optical system), and the third lens frame 6 has its open end facing downward (closed). (To the up optical system side). On the outer peripheral surface of the second lens frame 5, each of the rectilinear grooves 3 e and each of the first cam grooves 4
Three cam followers 10 penetrating the three intersections with a are planted. Each cam follower 10 includes a cam pin fixed to the lens frame 5 and a cylindrical collar that rotates around the cam pin. Similarly, on the outer peripheral surface of the third lens frame 6, three cam followers penetrating through three intersections of each straight groove 3 e and each second cam groove 4 b in a state of being fitted into the cam ring 4. 11 are planted. Each cam follower 11 is a cam follower 10
It has the same configuration as. Therefore, these two lens frames 5, 6
Are restricted from rotating with respect to the fixed ring 3 and are positioned at an axial position corresponding to the rotational position of the cam ring 4.

The illumination holes 5d and 6d overlapping with the illumination hole 3d of the stationary ring 3 and the illumination hole 8d of the lid 8 are opened in the two lens frames 5 and 6 in such a state that the rotation is restricted as described above. I have. The second lens frame 5 has both optical axes Ax2 and Ax2.
Coaxially with x3, cylindrical lens fixing cylinder parts 5b and 5c
It is integrally formed so as to protrude downward. The second lens groups 222 and 232 are held at substantially the centers of the insides of the two lens fixing cylinder portions 5b and 5c, respectively. Further, the third lens frame 6 is also formed integrally with the cylindrical lens fixing tube portions 6b and 6c so as to protrude downward coaxially with both optical axes Ax2 and Ax3. The third lens group 2 is provided inside each of the distal ends of the two lens fixing cylinders 6b and 6c.
23 and 233 are held. The inner diameters of the two lens fixing cylinders 6b, 6c are such that the lower ends of the fourth lens frames 9, 9 enter the inside thereof, and the fourth lens groups 224, 234
The third lens groups 223 and 233 are formed larger than the outer diameter of the lower ends of the fourth lens frames 9 and 9 so that the third lens groups 223 and 233 can approach each other.

As shown in FIG. 7 which is a perspective view,
3 on the inner peripheral surface of the lens frame 5 at equal angular intervals
At the locations (positions slightly shifted clockwise from the cam followers 10 as viewed from above), hooks 1 for spring hooking are provided, respectively.
2, 12, 12 are fixed. Similarly, spring-hook hooks are also provided at three locations on the inner peripheral surface of the third lens frame 6 that are equiangularly spaced from each other (positions slightly offset in a counterclockwise direction from the cam followers 11 when viewed from above). 1
3, 13, 13 are fixed. Then, each of the hooks 12, 12, 12 of the second lens frame 5 whose rotation is regulated by each of the cam followers 10, 11, and each of the hooks 13, 13, 13 of the third lens frame 6 corresponding thereto. Between the rectilinear grooves 3e, 3
e, 3e so as to cross diagonally from lower left to upper right,
Three tension springs 14, 14, 14 are respectively hung. 5 and 6, the extension spring 14 and the hooks 12 and 13 existing on the near side of the cross section are also illustrated in an overlapping manner.

Each of these tension springs 14, 14, 14
As shown in FIG. 8, the cam followers 10, 10, 10, 10, 10, 10, 10, 10, 10, An urging force (an obliquely upper rightward direction in FIG. 8) that combines a vector in the counterclockwise direction (right side in FIG. 8) and a vector in the third lens frame 6 side (upper side in FIG. 8) when viewed from above. Force) is applied to each of the cam followers 11, 11, 11 of the third lens frame 6 in a clockwise direction (left side in FIG. 8) as viewed from above and on the second lens frame 5 side (lower side in FIG. 8). (The biasing force in the diagonally downward left direction in FIG. 8)
Is added. As a result, each of the cam followers 10, 10, 10 of the second lens frame 5 has an inner edge (right edge in FIG. 8) of the rectilinear groove 3e on the counterclockwise side when viewed from above and the first cam groove 4
a is always in contact with the upper inner edge.
Similarly, each of the cam followers 11, 11, and
Numeral 11 is always in contact with the clockwise inner edge (left edge in FIG. 8) of the rectilinear groove 3e and the lower inner edge of the second cam groove 4b.

At the lower end of the inner peripheral surface of the cam ring 4 described above, an annular gear 15 having teeth formed on the inner periphery is fitted and fixed. A pinion 17 attached to a drive shaft of a motor 16 fixed to the bottom of the fixed ring 3 meshes with the annular gear 15. Therefore, when the motor 16 rotates the pinion 17 by an appropriate amount in an appropriate direction, the cam ring 4 rotates by an arbitrary angle in an arbitrary direction. As a result, the second lens groups 222 and 232 and the third lens groups 223 and 2 held by the respective lens frames 5 and 6
33 is moved to a position uniquely determined by the shapes of both cam grooves 4a and 4b, and the photographing magnification by the photographing optical system 200 changes.

During this movement, each cam follower 10 of the second lens frame 5 is always in contact with one of the inner edges of the straight groove 3e and the first cam groove 4a, regardless of the shape of the first cam groove 4a. Each cam follower 11 of the third lens frame 6
Is a linear groove 3e regardless of the shape of the second cam groove 4b.
And one end of each of the inner edges of the second cam groove 4b. For example, when the zoom optical systems 220 and 230 are at the telephoto end shown in FIGS. 5 and 6, the cam followers 10 and 11 are at the positions shown in FIG.
6 are close to each other, the inclination angle of each tension spring 14 with respect to the circumferential direction is small, so that each cam follower 10, 11
Are directed in the directions indicated by the arrows. When each of the zoom optical systems 220 and 230 is at the wide-angle end shown in the partial longitudinal sectional view of FIG. 10 and the perspective view of FIG.
Each of the cam followers 10, 11 is at the position shown in FIG.
Since the two lens frames 5 and 6 are separated from each other, the inclination angle of each tension spring 14 with respect to the circumferential direction is large, so that the urging force applied to each of the cam followers 10 and 11 is directed in the direction indicated by the arrow. In each case, each cam follower 10,
Reference numeral 11 denotes one inner edge of the straight groove 3e and the cam groove 4
a, 4b is always in contact with one inner edge,
Regardless of how the cam ring 4 rotates, backlash does not occur.

Therefore, regardless of the rotation direction of the cam ring 4, the second lens group 2 of both zoom optical systems 220 and 230
22 and 232 and the positions of the third lens groups 223 and 233 are shifted in the circumferential direction of the zoom lens barrel 2.
2,232,223,233 do not rotate around the optical axis. Even if the cam ring 4 is tilted when the motor 16 drives the cam ring 4, both zoom optical systems 22
0, 230 are tilted in the same direction.
The left and right images picked up by 1 do not relatively shift. Therefore, even if the direction of rotation of the cam ring 4 is reversed, the left and right images do not relatively move.

The fixed ring 3, the second lens frame 5, the third lens frame 6, and the illumination holes 3d, 5d, 6d, 8d of the lid 8 are
Both have the same shape, and do not shift in the circumferential direction regardless of the rotational position of the cam ring 4. And the illumination optical system 3
The light guide fiber bundle 105 for introducing illumination light into the illumination windows 3d, 5d, 6d, 8
It is inserted into d and fixed. Therefore, regardless of the existence of the light guide fiber bundle 105, both zoom optical systems 220 and 230 can be accommodated in the common zoom lens barrel 2.

[0056]

Embodiment 2 The second embodiment of the present invention differs from the above-described first embodiment only in the manner in which the tension springs 14 are applied to the second lens frame 5 and the third lens frame 6, and the other embodiments are the same. The configurations are all the same. Therefore, only the differences between the second embodiment and the first embodiment will be described below.

FIG. 14 shows the zoom optical systems 220 and 230.
FIG. 3 is a schematic longitudinal sectional view (part) of the stereoscopic microscope 101 along a plane including both the optical axes Ax2 and Ax3 of FIG. FIG.
14 is a schematic cross-sectional view along the line XIII-XIII in FIG. 14, and FIG. 15 is a schematic vertical cross-sectional view along the line XV-XV in FIG. As shown in each of these figures, the second
Each hook 12, 12, 12 fixed to the lens frame 5,
Each hook 13, 13, 13 fixed to the third lens frame 6
Includes separate tension springs (second group tension springs 18, 18, 18 for urging the second lens frame 5 and third tension springs).
Third group tension springs 19, 1 for urging the lens frame 6
9, 19). The other ends of the second group tension springs 18, 18, 18 are displaced clockwise when viewed from above the ends hooked on the hooks 12, 12, 12 fixed to the second lens frame 5. In position, it is hung on the bottom of the stationary ring 3. The other ends of the third group tension springs 19, 19, 19 are displaced in a counterclockwise direction as viewed from above the ends hooked on the hooks 13, 13, 13 fixed to the third lens frame 6. In the closed position.

Each of the second group tension springs 18, 18, 1
As shown in FIG. 16, the second lens frame 8 receives the contraction force applied to the hooks 12, 12, 12 of the second lens frame 5 as shown in FIG.
Each of the cam followers 10, 10, 10 has a vector in the clockwise direction (left side in FIG.
An urging force obtained by combining vectors toward the lens groups 221 and 231 (downward in FIG. 16) (urging force obliquely downward in FIG. 16) is applied. At the same time, each third group tension spring 1
Reference numerals 9, 19, and 19 denote hooks 13, 1 of the third lens frame 6, respectively.
Due to the contraction force applied to 3, 13 as shown in FIG.
Each of the cam followers 11, 11, 11 of the third lens frame 6 has a vector in a counterclockwise direction (the right side in FIG. 16) as viewed from above, and the fourth lens group 224, 234 side (FIG. 16).
16 (FIG. 16)
In the upper right direction). As a result, each of the cam followers 10, 10, 10 of the second lens frame 5 has a clockwise inner edge (left edge in FIG. 16) in the straight groove 3e and a lower inner edge of the first cam groove 4a. They are always in contact. Similarly, each of the cam followers 11, 11, 11 of the third lens frame 6 has an inner edge on the counterclockwise side (right edge in FIG. 8) as viewed from above in the straight groove 3e and an upper inner edge in the second cam groove 4b. Always in contact.

At the lower end of the inner peripheral surface of the cam ring 4 described above, an annular gear 15 having teeth formed on the inner periphery is fitted and fixed. A pinion 17 attached to a drive shaft of a motor 16 fixed to the bottom of the fixed ring 3 meshes with the annular gear 15. Therefore, when the motor 16 rotates the pinion 17 by an appropriate amount in an appropriate direction, the cam ring 4 rotates by an arbitrary angle in an arbitrary direction. As a result, the second lens groups 222 and 232 and the third lens groups 223 and 2 held by the respective lens frames 5 and 6
33 is moved to a position uniquely determined by the shapes of both cam grooves 4a and 4b, and the photographing magnification by the photographing optical system 200 changes.

During this movement, each cam follower 10 of the second lens frame 5 is always in contact with one of the inner edges of the linear groove 3e and the first cam groove 4a regardless of the shape of the first cam groove 4a. Each cam follower 11 of the third lens frame 6
Is a linear groove 3e regardless of the shape of the second cam groove 4b.
And one end of each of the inner edges of the second cam groove 4b. For example, each of the zoom optical systems 220 and 230 corresponds to FIG.
15 and at the telephoto end shown in FIG. 15, the cam followers 10 and 11 are at the positions shown in FIG. 17, and since the second lens frame 5 is separated from the bottom of the fixed ring 3, each of the tension springs 18 , 18, and 18 have a large inclination angle with respect to the circumferential direction, while the third lens frame 6 has a small inclination angle with respect to the circumferential direction of the tension springs 19, 19, and 19 because the third lens frame 6 is close to the lid 8. , 11 are directed in the directions indicated by the arrows. In addition, each zoom optical system 2
When the cam followers 20 and 230 are at the wide-angle ends shown in the partial longitudinal sectional views of FIGS. 18 and 19, the cam followers 10 and 11 are at the positions shown in FIG. , The inclination angles of the tension springs 18, 18, 18 with respect to the circumferential direction are small, whereas the tension springs 19, 19, 1 are located because the third lens frame 6 is separated from the lid 8.
Since the inclination angle of the cam follower 9 with respect to the circumferential direction is large, the urging force applied to each of the cam followers 10 and 11 is directed in the direction indicated by each arrow. In any case, each cam follower 11,
Reference numeral 12 denotes one inner edge of the straight groove 3e and the cam groove 4
a, 4b is always in contact with one inner edge,
Regardless of how the cam ring 4 rotates, backlash does not occur.

Therefore, regardless of the rotation direction of the cam ring 4, the second lens group 2 of both zoom optical systems 220 and 230
22 and 232 and the positions of the third lens groups 223 and 233 are shifted in the circumferential direction of the zoom lens barrel 2.
2,232,223,233 do not rotate around the optical axis. Even if the cam ring 4 is tilted when the motor 16 drives the cam ring 4, both zoom optical systems 22
0, 230 are tilted in the same direction.
The left and right images picked up by 1 do not relatively shift. Therefore, even if the direction of rotation of the cam ring 4 is reversed, the left and right images do not relatively move.

[0062]

Modification In each of the embodiments described above, the method of applying the tension springs 14 to the respective lens frames 5 and 6 has been specifically shown.
In addition, since it is only necessary to urge the cam ring 4 in an oblique direction (twist direction) with respect to the axial direction, various other methods can be adopted. For example, as shown in FIGS. 21A and 21B, the second embodiment is modified so that the two lens frames 5, 6 are moved in the same direction by the tension springs 18, 19 dedicated to the respective lens frames 5, 6. You may pull it. FIG.
As shown in (c), the first embodiment is modified,
The inclination direction of the tension spring 14 hung between the lens frames 5 and 6 may be reversed.

[0063]

As described above, according to the binocular lens barrel of the present invention, despite the structure in which a part of the lens groups constituting the pair of right and left objective optical systems are moved in synchronization with each other, During the movement, the respective lens groups are not decentered, so that the finally formed left and right images do not relatively move. As a result, an enlarged image of the observation target can be always stereoscopically viewed naturally.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the overall configuration of a surgery support system incorporating a video stereo microscope according to a first embodiment of the present invention;

FIG. 2 is a plan view of an LCD panel built in the stereoscopic viewer.

FIG. 3 is a perspective view showing an optical system of a video stereo microscope.

FIG. 4 is a schematic cross-sectional view of a video stereo microscope.

FIG. 5 is a schematic longitudinal sectional view taken along line VV in FIG. 4;

FIG. 6 is a schematic longitudinal sectional view taken along the line VI-VI in FIG. 4;

FIG. 7 is a perspective view showing an assembled state of both lens frames and a tension spring.

FIG. 8 is a development view showing the shapes of the rectilinear grooves and the respective cam grooves, and the directions of the urging forces applied to the respective cam followers.

FIG. 9 is a developed view showing the position of each cam follower at the telephoto end.

FIG. 10 is a partial longitudinal sectional view showing a state of both lens frames and a tension spring at a wide angle end.

FIG. 11 is a perspective view showing a state of both lens frames and a tension spring at a wide-angle end.

FIG. 12 is a development view showing the position of each cam follower at the wide-angle end.

FIG. 13 is a schematic cross-sectional view of a video stereo microscope according to a second embodiment of the present invention.

14 is a schematic longitudinal sectional view taken along the line XIV-XIV in FIG.

15 is a schematic longitudinal sectional view taken along the line XV-XV in FIG.

FIG. 16 is an exploded view showing the shapes of the rectilinear grooves and the respective cam grooves and the directions of the urging forces applied to the respective cam followers.

FIG. 17 is a developed view showing the position of each cam follower at the telephoto end.

FIG. 18 is a partial longitudinal sectional view showing a state of both lens frames and a tension spring at a wide angle end.

FIG. 19 is a partial longitudinal sectional view showing a state of both lens frames and a tension spring at a wide-angle end.

FIG. 20 is a developed view showing the position of each cam follower at the wide-angle end.

FIG. 21 is an explanatory view of a modification of the present invention.

FIG. 22 is a longitudinal sectional view of a zoom lens barrel showing a conventional example.

FIG. 23 is a perspective perspective view showing a conventional example.

FIG. 24 is an explanatory view of the inclination of each zoom lens barrel in the conventional example.

[Explanation of symbols]

 Reference Signs List 1 housing 2 zoom lens barrel 3 fixed ring 4 cam ring 4a first cam groove 4b second cam groove 5 second lens frame 6 third lens frame 10 cam follower 11 cam follower 12 hook 13 hook 14 tension spring 18 tension spring 19 tension spring 220 zoom optical system 222 second lens group 223 third lens group 230 zoom optical system 232 second lens group 233 third lens group

Claims (8)

[Claims] 1. A binocular lens barrel for holding a moving lens group in a pair of objective optical systems for forming images of the same object from positions separated by a predetermined base line length, respectively. A fixed ring formed of a cylindrical member having a central axis parallel to the optical axis of the optical system, a straight groove formed parallel to the central axis, and a cylindrical member having a central axis parallel to the optical axis; A cam ring, which is rotatably fitted only to the fixed ring and has a cam groove having a portion inclined with respect to the center axis thereof, and the optical axis inside the fixed ring and the cam ring. A lens frame that is movably held only in a parallel direction and that holds the moving lens groups in both the objective optical systems; and a lens frame that is attached to the lens frame and that has the linear groove and the cam groove. Camfo penetrating the intersection A binocular lens barrel comprising: a lower member; and a biasing member that biases the lens frame in a direction oblique to an optical axis of each of the objective optical systems. 2. Each of the objective optical systems includes two moving lens groups, and the cam groove, the lens frame, and the cam follower are provided corresponding to each of the moving lens groups. The binocular lens barrel according to claim 1, wherein: 3. The binocular lens barrel according to claim 2, wherein said biasing member is provided for each lens frame. 4. The binocular lens barrel according to claim 2, wherein said urging member urges both lens frames simultaneously. 5. The binocular lens barrel according to claim 1, wherein said biasing member is a spring. 6. The binocular according to claim 3, wherein each of the biasing members is a tension spring that is obliquely attached to the optical axis between each of the lens frames and the fixed frame. Lens barrel. 7. The binocular lens barrel according to claim 4, wherein said urging member is a tension spring that is hung obliquely with respect to said optical axis between said two lens frames. 8. The apparatus according to claim 1, wherein a plurality of said rectilinear grooves, said cam grooves, said cam followers and said biasing members are provided at equal angular intervals around the central axis of said fixed ring and said cam ring. The binocular lens barrel according to any one of 1 to 7.