JP3605315B2 - Stereoscopic microscope - Google Patents

Description

【００５９】
【実施例２】
図１１は、実施例２にかかる顕微鏡光学系を展開して示すレンズ図である。実施例２の顕微鏡光学系の具体的な数値構成は表２に示されている。面番号と各光学素子との対応は実施例１におけるのと同様である。実施例２におけるリレー光学系２４０，２５０の結像倍率Ｍ_Ｒは、−１．５倍である。
【００６０】
【表２】

【００６１】
【実施例３】
図１２は、実施例３にかかる顕微鏡光学系を展開して示すレンズ図である。実施例３の顕微鏡光学系の具体的な数値構成は表３に示されている。面番号と各光学素子との対応は実施例１におけるのと同様である。実施例３におけるリレー光学系２４０，２５０の結像倍率Ｍ_Ｒは、−１．８７５倍である。
【００６２】
【表３】

【００６３】
【実施例４】
図１３は、実施例４にかかる顕微鏡光学系を展開して示すレンズ図である。実施例４の顕微鏡光学系の具体的な数値構成は表４に示されている。面番号と各光学素子との対応は実施例１におけるのと同様である。実施例４におけるリレー光学系２４０，２５０の結像倍率Ｍ_Ｒは、−２．０倍である。
【００６４】
【表４】

【００６５】
【発明の効果】
以上に説明したように、本発明の立体視顕微鏡によると、対物光学系により形成された一次像をリレーするリレー光学系の結像倍率Ｍ_Ｒを、−３＜Ｍ_Ｒ＜−１の範囲に設定することにより、対物光学系に含まれるズーム光学系の可変焦点距離の上限及び下限を短くすることができ、レンズ枚数が多いズーム光学系のサイズ、重量を軽減し、顕微鏡の小型、軽量化を図ることができる。
【図面の簡単な説明】
【図１】本発明の第１実施形態による立体視顕微鏡を組み込んだ手術支援システムの全体構成を示す概略図。
【図２】立体視顕微鏡内の光学構成の概略を示す光学構成図。
【図３】立体視ビューワの光学構成の概略を示す光学構成図。
【図４】ＬＣＤパネルの平面図。
【図５】立体視顕微鏡の外観斜視図。
【図６】顕微鏡光学系の全体構成を示す斜視図。
【図７】図６に示す顕微鏡光学系の側面図。
【図８】図６に示す顕微鏡光学系の正面図。
【図９】図６に示す顕微鏡光学系の平面図。
【図１０】実施例１の撮影光学系を展開して示すレンズ図。
【図１１】実施例２の撮影光学系を展開して示すレンズ図。
【図１２】実施例３の撮影光学系を展開して示すレンズ図。
【図１３】実施例４の撮影光学系を展開して示すレンズ図。
【符号の説明】
１０２ ＣＣＤカメラ
２００ 撮影光学系
２１０ クローズアップ光学系
２２０，２３０ ズーム光学系
２４０，２５０ リレー光学系
２６０ 輻輳寄せプリズム
２７０，２７１ 視野絞り
２７２，２７３ ペンタプリズム
３００ 照明光学系
３１０ 照明レンズ
３２０ 楔プリズム[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a stereoscopic microscope for magnifying and observing an observation target, and more particularly to a stereoscopic microscope of a type in which a microscope image is electrically photographed by an image sensor.
[0002]
[Prior art]
A stereoscopic microscope is used, for example, when treating fine tissue such as neurosurgery.
That is, it is difficult to visually discriminate the structural tissue of an organ composed of a fine tissue such as the brain, so that such an organ must be treated under a microscope. Moreover, since it is difficult to recognize the three-dimensional structure of the tissue with a monocular microscope, it is possible to perform an accurate treatment by observing the tissue three-dimensionally. Was used.
[0003]
However, conventional stereoscopic microscopes are designed so that the eyepiece of the microscope can be viewed directly with the naked eye, so that the main surgeon in charge of surgery (or an assistant in some cases) can see the microscope image, Others (eg, anesthesiologist, nurse, resident, advisor in a remote location) cannot view the same microscope image, so they can perform quick and accurate assignments or provide appropriate advice from a remote location. Can not do.
[0004]
Therefore, a method of outputting a microscope image as an electric signal using an image sensor has been conventionally proposed. According to this, the photographed images are displayed on a plurality of displays, and each of them is observed using the stereoscopic viewer, so that a plurality of persons can simultaneously stereoscopically view the microscope image. For example, Japanese Patent Laying-Open No. 7-104193 discloses a configuration in which a photographing system optical adapter is attached to a stage subsequent to an eyepiece of a binocular microscope and a microscope image is photographed by a high-vision camera. The imaging system optical adapter includes a relay optical system that relays subject light from an eyepiece to form an image on an image sensor, and a high-vision CCD as an image sensor.
[0005]
[Problems to be solved by the invention]
However, the stereoscopic microscope disclosed in the above publication has a configuration in which a binocular microscope for macroscopic observation is used and an adapter is added thereto, so that the observation optical system can obtain a sufficient magnification during macroscopic observation. Designed, there is a problem that the size of the entire system including the binocular microscope and the adapter increases due to an increase in the size of the optical system.
[0006]
The present invention has been made in view of the above-described problems of the related art, and the problem is not to divert a binocular microscope for macroscopic observation but to specialize as a stereoscopic microscope using an imaging element. Accordingly, an object of the present invention is to provide a stereoscopic microscope capable of reducing the size of the optical system of the entire system.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the stereoscopic microscope of the present invention has a single optical axis, a close-up optical system arranged opposite to a subject, and a close-up optical system, respectively. It has a parallel optical axis and is formed by a pair of zoom optical systems capable of zooming to form a primary image of a subject at a certain position by subject light passing through different places in the close-up optical system, and a zoom optical system. A pair of field stops that are respectively arranged at the positions of the primary images and define the edges of the primary image, a pair of relay optical systems that relay the primary image to form a secondary image of the subject, and a pair of secondary images. An imaging element for photographing, and an image forming magnification M of each relay optical system. _R However, the following conditions,
-3 <M _R <-1
Is satisfied.
[0008]
According to the above configuration, the subject light enters via the close-up optical system, and a pair of primary images having a predetermined parallax is formed at the position of the field stop by the pair of zoom optical systems. The close-up optical system is adjusted so that the subject is located at the focal position, and has a collimating function of converting divergent light from the subject into substantially parallel light. The primary image is relayed by a pair of relay optical systems to form a pair of secondary images on the imaging surface. The photographed image is displayed on a display device such as a liquid crystal display or a CRT. By observing the image with both eyes using a stereoscopic viewer, the subject can be enlarged and observed by stereoscopic vision.
[0009]
When capturing a color image, for example, a single color CCD may be provided as an image sensor, or a CCD may be provided for each color component via a color separation optical system.
[0010]
In the case where an inter-optical axis distance reducing element that brings the subject light from the relay optical system close to each other is provided between the relay optical system and the imaging element, the imaging element is formed in an adjacent area of a single imaging surface. A secondary image can be taken.
[0011]
Further, the relay optical system includes first, second, and third lens groups each having a positive power in order from the field stop side, and the divergent light transmitted through the field stop by the first and second lens groups is substantially reduced. It is desirable that the light be parallel and converged by the third lens group.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
The stereoscopic microscope according to the embodiment described below is used, for example, by incorporating it into a surgery support system used in neurosurgery. This surgery support system combines a stereoscopic image (stereo image) obtained by video-taking a tissue of a patient with a stereoscopic microscope with a CG (computer graphic) image created based on data of an affected part obtained in advance. Then, the system displays the image on a stereoscopic viewer dedicated to the main operator, a monitor for other staff, or the like, and records the image on a recording device.
[0014]
(Overall configuration of the surgery support system)
FIG. 1 is a system configuration diagram showing an outline of this surgery support system. As shown in FIG. 1, the surgery support system includes a stereoscopic microscope 101, a high-vision CCD camera 102 attached near the upper end of the back of the stereoscopic microscope 101, and a microscope position measurement also attached near the lower end. A device 103, a counterweight 104 attached to the upper surface of the stereoscopic microscope 101, a light guide fiber 105 penetrating through a through hole formed in the counterweight 104 and conducting to the inside of the stereoscopic microscope 101; A light source device 106 for introducing illumination light to the stereoscopic microscope 101 through a light guide fiber 105, a surgical planning computer 108 having a disk device 107, and real-time CG creation connected to the microscope position measuring device 103 and the surgical planning computer 108 The device 109 and this real An image synthesizing device 110 connected to the im CG creating device 109 and the high-vision CCD camera 102, a distributor 111 connected to the image synthesizing device 110, a recording device 115, a monitor 114, and a stereoscopic device connected to the distributor 111. It comprises a visual viewer 113 and the like.
[0015]
The above-mentioned disk device 107 stores images (CT scan images, MRI images, SPECT images, angiographic images, etc.) obtained by previously imaging the affected part of the patient P with various imaging devices, and the like. In addition, three-dimensional data of the diseased part and the surrounding tissue created in advance based on these various images are stored. Note that the three-dimensional data is based on three-dimensional local coordinates defined using a reference point (marking or the like) set at a specific part of the outer skin or internal tissue of the patient P as the origin and the shape and size of the affected part and surrounding tissue. And data specifying the position in a vector format or a map format.
[0016]
Further, the above-described stereoscopic microscope 101 is detachably fixed to the tip of the free arm 100a of the first stand 100 via a mount attached to the back surface. Accordingly, the stereoscopic microscope 101 is movable within a radius that the free arm 100a of the first stand 100 can reach, and can be oriented in any direction. However, here, for convenience, the direction of the subject with respect to the stereoscopic microscope 101 is defined as “down”, and the opposite direction is defined as “up”.
[0017]
The optical configuration in the stereoscopic microscope 101 will be described in detail later. The schematic configuration is described below. As shown in FIG. 2, the imaging optical system 200 has a large-diameter close-up having a single optical axis. An objective optical system including an optical system 210, a pair of left and right zoom optical systems 220 and 230 for forming a primary image of a subject by subject light transmitted through different portions of the close-up optical system 210, and zoom optical systems 220 and 230 A pair of left and right field stops 270, 271 arranged at the position of the primary image of the subject according to, and a pair of left and right relay optical systems 240, 250 for relaying the primary image. The subject light relayed by the relay optical systems 240 and 250 is introduced into the high-definition CCD camera 102, and the left and right imaging regions (vertical and horizontal directions) in the CCD 116 having an imaging surface of a high-definition size (vertical and horizontal aspect ratio = 9: 16). Each is re-imaged as a secondary image at an aspect ratio of 9: 8). In this optical system, the zoom optical system 220 and the relay optical system 240 constitute a right photographing optical system while the close-up optical system 210 is a common element, and the zoom optical system 230 and the relay optical system 250 constitute the left photographing optical system. And a pair of photographing optical systems arranged together with a predetermined baseline length therebetween.
[0018]
An image formed in each of the left and right imaging regions on the imaging surface of the CCD 116 by such a pair of imaging optical systems 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. It is. The output signal of the CCD 116 is generated as a Hi-Vision signal by the image processor 117 and output from the Hi-Vision CCD camera 102 to the image synthesizing device 110. The stereoscopic microscope 101 incorporates an illumination optical system 300 (see FIG. 6) for illuminating a subject existing near the focus position of the close-up optical system 210. Then, illumination light is introduced into the illumination optical system 300 from the light source device 106 via the light guide fiber bundle 105.
[0019]
Returning to FIG. 1, the microscope position measuring device 103 attached to the stereoscopic microscope 101 has a distance to a subject existing on the optical axis of the close-up optical system 210 and a three-dimensional orientation of the optical axis of the close-up optical system 210. , The position of the reference point is measured, and the position of the subject in the local coordinates is calculated based on the measured information. Then, the information of the direction of the optical axis and the position of the subject is notified to the real-time CG creation device 109.
[0020]
The real-time CG creation device 109 determines the direction of the optical axis based on the information of the direction of the optical axis and the position of the subject notified from the microscope position measuring device 103 and the three-dimensional data downloaded from the surgical planning computer 108. A CG image (for example, a wire frame image) equivalent to a stereoscopic view of an affected part (for example, a tumor) is generated in real time. This CG image is generated as a stereoscopic image (stereo image) at the same base line length and the same subject distance as the optical system in the stereoscopic microscope 101. Then, the real-time CG creation device 109 inputs a CG image signal indicating the CG image generated in this way to the image synthesis device 110 as needed.
[0021]
The image synthesizing device 110 superimposes the CG image signal obtained from the real-time CG creating device 109 on the scale of the actual high-definition signal of the subject input from the high-vision CCD camera 102 by adjusting the scale. In an image indicated by a high-definition signal obtained by superimposing such a CG image signal, the shape, size, and position of the affected part in an image obtained by actually photographing are represented as a CG image such as a wire frame. It is shown. The superimposed Hi-Vision signal is transmitted by the distributor 111 to a stereoscopic viewer 113 for the operator D, a monitor 114 for other surgical staff or an advisor at a remote location, and a recording device 115. Supplied respectively.
[0022]
The stereoscopic viewer 113 is attached so as to hang down from the tip of the free arm 112 a of the second stand 112. 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. FIG. 3 shows a schematic configuration of the stereoscopic viewer 113. As shown in FIG. 3, the stereoscopic viewer 113 has a built-in high-definition size LCD panel 120 as a monitor. When an image based on the HDTV signal from the distributor is displayed on the LCD panel 120, as shown in the plan view of FIG. 4, the left half 120 b of the LCD panel 120 is photographed in the left imaging area of the CCD 116. The right half 120a displays an image photographed in the right photographing area of the CCD 116.
[0023]
The boundary 120c between these left and right images shifts or tilts depending on the position of the field stops 270 and 271 described later. The optical path in the stereoscopic viewer 113 is divided into right and left by a partition wall 121 installed perpendicular to the boundary line 120c when the field stops 270 and 271 are accurately adjusted. On both sides of the partition 121, a wedge prism 119 and an eyepiece 118 are arranged in order from the LCD panel 120 side. The eyepiece 118 is a lens that enlarges and forms a virtual image of an image displayed on the LCD panel 120 at a position about 1 m (-1 diopter) in front of the observation eye I. The wedge prism 119 corrects the traveling direction of light so that the convergence angle of the observation eye I is equal to the angle at which an object existing 1 m ahead is observed, thereby enabling natural stereoscopic observation.
[0024]
As described above, in an image stereoscopically viewed by the stereoscopic viewer 113 or an image displayed on the monitor 114, as described above, a tumor or the like detected based on an image previously captured by various imaging devices is used. A CG such as a wire frame indicating the shape, size and position of the affected part is superimposed. Therefore, the main operator D or other surgical staff observing them can easily identify the affected part that is difficult to identify in the actual video. This enables accurate and quick treatment.
[0025]
(Configuration of stereoscopic observation device)
Next, a specific configuration of the above-described stereoscopic microscope 101 (including the high-vision CCD camera 102) will be described in detail. As shown in the perspective view of FIG. 5, the stereoscopic microscope 101 has a substantially prismatic shape with a flat back surface to which the high-definition CCD camera 102 is attached and chamfered on both sides of the front surface (opposite the back surface). Having. At the center of the upper surface, a concave portion 101a having a circular opening is formed. At the center of the concave portion 101a, an insertion opening (not shown) for inserting a guide pipe 122, which is a cylindrical member into which the tip of the light guide fiber bundle 105 is inserted and fixed, is formed. The annular member (fiber guide insertion portion) 123 attached to the opening of the insertion port is a chuck for fixing the guide pipe 122 inserted into the insertion port.
[0026]
<Optical configuration>
Next, an optical configuration in the stereoscopic microscope 101 will be described with reference to FIGS. 6 is a perspective view showing the entire configuration of the microscope optical system, FIG. 7 is a side view, FIG. 8 is a front view, and FIG. 9 is a plan view.
[0027]
As shown in FIG. 6, the microscope optical system includes a photographing optical system 200 for electronically photographing an image of a subject, and an illumination optical system for illuminating the subject with illumination light guided from a light source device 106 by a light guide fiber bundle 105. And a system 300.
[0028]
The photographing optical system 200 relays an objective optical system including the close-up optical system 210 and the pair of left and right zoom optical systems 220 and 230 as described above, and a primary image of a subject formed by the objective optical system. And a pair of left and right relay optical systems 240 and 250 for forming a secondary image of the subject, and a converging prism 260 as an optical axis distance reducing element for bringing subject light from these relay optical systems 240 and 250 close to each other. Have.
[0029]
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. A pentaprism as an optical path deflecting element that deflects the optical path at right angles is provided in the relay optical systems 240 and 250. 272, 273 are arranged respectively.
[0030]
With such a configuration, left and right object images having a predetermined parallax can be formed in two adjacent areas on the CCD 116 arranged in the CCD camera 102. In the description of the optical system, "left and right" are directions that match the longitudinal direction of the imaging surface when projected on the CCD 116, and "up and down" are directions that are orthogonal to the left and right directions on the CCD 116. Hereinafter, the configuration of each optical system will be described in order.
[0031]
As shown in FIGS. 6, 7, and 8, the close-up optical system 210 includes a negative first lens group 211 and a positive second lens group 212 arranged in order from the object side. The second lens group 212 is movable in the optical axis direction, and can adjust the movement to focus on objects at different distances. That is, the close-up optical system 210 is adjusted so that the subject is located at the focal position, and has a collimating function of converting divergent light from the subject into substantially parallel light.
[0032]
Each of the first and second lens groups 211 and 212 of the close-up optical system 210 has a substantially semicircular shape whose D-cut planar shape is viewed from the optical axis direction. Is arranged.
[0033]
The pair of zoom optical systems 220 and 230 focus the subject light from the close-up optical system 210 at infinity at the positions of the field stops 270 and 271, respectively.
As shown in FIGS. 6 to 8, one zoom optical system 220 includes first to fourth lens groups 221 and 222 having positive, negative, negative, and positive powers, respectively, from the close-up optical system 210 side. The first and fourth lens groups 221 and 224 are fixed, and zooming is performed by moving the second and third lens groups 222 and 223 in the optical axis direction. The magnification is changed mainly by moving the second lens group 222, and the focal position is kept constant by moving the third lens group 223.
[0034]
The other zoom optical system 230 has the same configuration as the above-described zoom optical system 220, and includes the first to fourth lens groups 231, 232, 233, and 234. These zoom optical systems 220 and 230 are linked by a drive mechanism (not shown), and can simultaneously change the photographing magnification of the left and right images.
The optical axes Ax2 and Ax3 of the zoom optical systems 220 and 230 are parallel to the optical axis Ax1 of the close-up optical system 210, and as shown in FIG. The plane including Ax3 is separated from the meridional plane of the close-up optical system 210 parallel to this plane by Δ on the opposite side of the D cut portion.
[0035]
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. By setting the optical axes Ax2 and Ax3 of the zoom optical systems 220 and 230 at positions away from the meridional surface of the close-up optical system 210 as described above, two circular spaces occupied by the pair of zoom optical systems 220 and 230. And the circular space occupied by the illumination optical system 300 can be efficiently arranged in the circular space occupied by the close-up optical system 210. Therefore, the D-cut portion can be enlarged while keeping the pupils of the zoom optical systems 220 and 230 large, so that the illumination optical system 300 can also be a close-up optical system. 210 Can be accommodated within the diameter occupied by, and the whole can be compactly assembled.
[0036]
Further, as described above, the objective optical system is divided into the close-up optical system 210 and the pair of zoom optical systems 220 and 230, so that a long working distance (the surface of the close-up optical system 210 closest to the subject from the subject to the close-up optical system 210) is obtained. ) And a high zoom ratio, and the adjustment mechanism and optical design can be simplified. That is, by sharing the close-up optical system 210 for the left and right images, the focus of the left and right images can be simultaneously adjusted by moving a single lens, so that the mechanism for focus adjustment can be simplified. In addition, the close-up optical system 210 only needs to realize the function of converting the subject light into parallel light, and the zoom optical systems 220 and 230 only need to realize the function of forming the primary image so that the primary image can be zoomed by the incident parallel light. Therefore, the optical design of each optical system can be simplified. Note that the four-group type zoom lens can secure a large zoom ratio and does not change the overall length, and therefore is used as a zoom optical system provided in the middle of a plurality of optical systems as in the embodiment. Desirable for.
[0037]
The field stops 270 and 271 are arranged at positions of primary images formed by the zoom optical systems 220 and 230. As shown in FIG. 6, the field stops 270 and 271 have a circular outer shape and have semicircular openings on the inside in the left and right directions, respectively. Each of the field stops 270 and 271 is arranged such that the straight edge of the opening coincides with the direction corresponding to the boundary between the left and right images on the CCD 116, and transmits only light beams inside the boundary.
[0038]
As described above, in the microscope of the embodiment, since the left and right secondary images are formed in adjacent regions on the single CCD 116, it is necessary to clarify the boundary between the left and right images on the CCD 116 and prevent the images from overlapping. is there. For this reason, field stops 270 and 271 are arranged at the position of the primary image. By making the straight edge of the semicircular aperture function as a so-called knife edge and transmitting only the light beam inside the edge, the boundary between the left and right images on the CCD 116 can be clarified.
[0039]
The field stop 270,271 The primary image formed thereon is re-imaged by the relay optical systems 240 and 250 to become a secondary image, and is reflected an even number of times in the optical path between the primary image and the secondary image both left and right and up and down. The top and bottom and the left and right are inverted between the primary image and the secondary image. Therefore, the knife edge that defines the outside in the left-right direction at the position of the primary image defines the inside in the left-right direction at the position of the secondary image, that is, the boundary between the left and right images.
[0040]
The relay optical systems 240 and 250 have the function of re-imaging the primary image formed by the zoom optical systems 220 and 230 as described above, and each is constituted by three positive lens groups.
As shown in FIGS. 6 and 7, one relay optical system 240 is composed of a first lens group 241 composed of a single positive meniscus lens, and a negative / positive cemented lens. And a third lens group 243 composed of a single biconvex lens. A pentaprism 272 as an optical path deflecting element that deflects the optical path at right angles is disposed between the first lens group 241 and the second lens group 242, and between the second lens group 242 and the third lens group 243. Is provided with a brightness stop 244 for adjusting the amount of light.
[0041]
The other relay optical system 250 also has the same configuration as the above-described relay optical system 240, and includes first, second, and third lens groups 251, 252, and 253, and includes a first lens group 251 and a second lens group 252. A pentaprism 273 as an optical path deflecting element is disposed between the second lens group 252 and the third lens group 253, and a brightness stop 254 is provided between the second lens group 252 and the third lens group 253.
[0042]
The divergent light that has passed through the field stops 270 and 271 is again converted into substantially parallel light by the first lens group 241, 251 and the second lens group 242, 252 of the relay optical system, and after passing through the brightness stop 244, 254. The image is formed again by the third lens groups 243 and 253 to form a secondary image. That is, the first lens groups 241 and 251 and the second lens groups 242 and 252 of the relay optical system constitute a collimating lens group that makes the subject light from the field stops 270 and 271 almost parallel light, and the third lens group 243. , 253 have a function as a converging lens group for converging subject light from the collimating lens group.
[0043]
By disposing the pentaprisms 272 and 273 in the relay optical systems 240 and 250, the overall length of the photographing optical system 200 along the optical axis direction of the close-up optical system 210 can be shortened. When a mirror is used as the optical path deflecting element, the direction of the reflected light is largely deviated due to an angular deviation. However, by using the pentaprisms 272 and 273, an axis perpendicular to a plane including both optical axes deflected at right angles is obtained. Even when the angle is deviated around, the reflection direction can be kept constant.
[0044]
In the relay optical systems 240 and 250, the second lens groups 242 and 252 and the third lens groups 243 and 253 can be adjusted in the optical axis direction and in the direction perpendicular to the optical axis. By moving these second and third lens groups 242, 252, 243, 253 in the optical axis direction to change the combined focal length of the first lens groups 241, 251 and the second lens groups 242, 252, the relay The magnification (the image height of the secondary image) of the entire optical systems 240 and 250 can be adjusted. Further, by moving only the third lens groups 243 and 253 in the optical axis direction, the back focus of the relay optical system is changed, and the focus of the CCD 116 can be adjusted. Further, by adjusting the second lens group 242, 252 and the third lens group 243, 253 integrally in the direction perpendicular to the optical axis, the position of the secondary image in the plane orthogonal to the optical axis is adjusted. be able to. For such adjustment, the second lens group 242, 252 and the third lens group 243, 253 are held by an integral outer lens barrel, and the third lens group 243, 253 further illuminates the outer lens barrel. It is held by an inner barrel that can move in the axial direction.
[0045]
As described above, since the second lens groups 242 and 252 and the third lens groups 243 and 253 move for adjustment, providing the pentaprisms 272 and 273 between these lens groups complicates the adjustment mechanism. Therefore, it is desirable to provide the pentaprisms 272 and 273 between the field stops 270 and 271 and the second lens groups 242 and 252. Furthermore, since the degree of divergence of the subject light is weakened by the first lens groups 241 and 251, in order to reduce the effective diameter of the pentaprism, the pentaprisms 272 and 273 are connected to the first lens groups 241 and 251 as in the embodiment. It is desirable to provide between the second lens groups 242 and 252.
[0046]
The 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, a predetermined base line length is required between the left and right zoom optical systems 220 and 230 and 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 convergence shifting prism 260 shifts the optical axes of the relay optical systems to the inside, respectively, so that an image can be formed on the same CCD while securing a predetermined base line length.
[0047]
As shown in FIGS. 6 and 9, the convergence shift prism 260 is configured by arranging pentagonal symmetrical optical axis shift prisms 261 and 262 facing each other with a gap of about 0.1 mm.
As shown in FIG. 9, the optical axis shift prisms 261 and 262 have an incident end face and an exit end face that are parallel to each other, and have first and second reflective surfaces that are parallel to each other inside and outside. In addition, 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 with. As the inter-optical axis distance reducing element, two reflecting surfaces parallel to each other are required. By configuring this as a prism as described above, the mutual positional relationship between the two reflecting surfaces is fixed, and the plane mirror is used. Adjustment is easier than using two sheets.
[0048]
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-right direction, and is incident again on the inner reflecting surface. The light is reflected in the same optical axis direction as that at the time, exits from the exit end face, and enters the CCD camera 102. As a result, the left and right object lights are narrowed only in the left and right intervals without changing their traveling directions, and a secondary image is formed on the same CCD 116.
[0049]
The illumination optical system 300 has a function of projecting illumination light onto a subject, and as shown in FIGS. 6 and 7, an illumination lens 310 for adjusting the degree of divergence of divergent light emitted from the light guide fiber bundle 105; And a wedge prism 320 for matching the range with the photographing range. The optical axis Ax4 of the illumination lens 310 is parallel to the optical axis Ax1 of the close-up optical system 210 and is decentered by a predetermined amount as shown in FIG. Do not match, and the amount of illumination light is wasted. By providing the wedge prism 310, the above mismatch can be eliminated, and the amount of illumination light can be used effectively.
[0050]
The above-described photographing optical system 200 is designed specifically for a stereoscopic microscope using an image sensor, and the zoom optical systems 220 and 230 are set to have a lower magnification than the objective optical system of the binocular microscope for visual observation. Imaging magnification M of minute relay optical systems 240 and 250 _R However, the following conditions,
-3 <M _R <-1
Is set to satisfy.
[0051]
In general, as the focal length of a zoom lens increases, the overall lens length, the lens diameter, and the weight increase. In particular, in a high-resolution zoom lens used for a microscope, the number of constituent lenses is large, so that the total focal length and the weight are significantly increased by increasing the focal length. Therefore, by setting the focal lengths of the zoom optical systems 220 and 230 to be short as described above, the size and weight of the entire stereoscopic microscope can be reduced.
[0052]
The comparison will be described below using specific numerical values as examples. In a system in which a conventional binocular microscope and an imaging system optical adapter are combined, the magnification of the zoom optical system must be set in consideration of the use of the binocular microscope alone. On the other hand, since the magnification on the binocular microscope side is sufficiently high, it is sufficient to use the same magnification imaging system as the relay optical system on the adapter side. For example, when a secondary image is formed in an area of 2 mm × 2 mm using a zoom optical system of F6 / 18 to 180 mm with a magnification ratio of 10 and a relay optical system of the same magnification, the zoom optical system and the relay optical system The size is as follows.
Zoom optical system: Total length 230mm, lens maximum effective diameter 58mm
Relay optical system: total length 222 mm, maximum lens effective diameter 18 mm
[0053]
On the other hand, in the system of the embodiment, for example, a zoom optical system having a zoom ratio of 10 times of F4 / 12-120 mm and a relay optical system having an image forming magnification of 1.5 times are arranged in the same area as above. When the next image is formed, since the focal length range of the zoom optical systems 220 and 230 is 2/3, the total length and the lens diameter are about 2/3 by simple calculation, and the volume and weight are about 8/27. Also, the magnification of the relay optical systems 240 and 250 is increased from the same magnification to 1.5 times, so that the focal length of the first lens groups 241 and 251 can be reduced to 2/3. Therefore, the sizes of the zoom optical systems 220 and 230 and the relay optical systems 240 and 250 are as follows.
Zoom optical system: Total length 120 mm, lens maximum effective diameter 30 mm
Relay optical system: total length 199mm, maximum lens effective diameter 14mm
[0054]
Note that the imaging magnification M of the relay optical system _R When -1 or more, the effect of miniaturizing the zoom optical system described above cannot be obtained. Further, the imaging magnification M _R When -3 or less, the focal length at the wide-angle end of the zoom optical system becomes too short to cover a fixed zoom range, and the angle of view becomes excessively large, making it difficult to correct aberrations. Also, in order to maintain the illuminance on the CCD surface at or above a certain value, it is necessary to reduce the F number of the first lens group of the zoom optical system and the relay optical system in proportion to the magnification of the relay optical system, It becomes difficult to correct aberration.
[0055]
Next, four specific examples of the imaging optical system 200 of the stereoscopic microscope according to the above embodiment will be described.
[0056]
Embodiment 1
FIG. 10 is a lens diagram showing the imaging optical system according to the first embodiment in a developed manner. Table 1 shows specific numerical configurations of the microscope optical system according to the first embodiment. The surface numbers 1 to 6 indicate the close-up optical system 210, the surface numbers 1 to 3 indicate the first lens group 211, and the surface numbers 4 to 6 indicate the second lens group 212. The surface numbers 7 to 23 are the zoom optical system 220, the surface numbers 7 to 11 are the first lens group 221, the surface numbers 12 to 14 are the second lens group 222, the surface numbers 15 and 16 are the third lens group 223, Numbers 17 to 23 indicate the fourth lens group. The surface numbers 24 to 32 are the relay optical system 240, the surface numbers 24 and 25 are the first lens group 241, the surface numbers 26 and 27 are the pentaprism 272, the surface numbers 28 to 30 are the second lens group 242, and the surface number 31. , 32 indicate the third lens group 243. Surface numbers 33 and 34 indicate an optical axis shift prism 261, and surface numbers 35 and 36 indicate a color separation prism 280 arranged in the CCD camera 102. Image magnification M of relay optical systems 240 and 250 in the first embodiment _R Is -1.5 times.
[0057]
In the table, r is the radius of curvature (unit: mm) of each lens surface, d is the lens thickness or lens interval (unit: mm), n is the refractive index of each lens at a wavelength of 588 nm, and νd is the Abbe number of each lens. .
[0058]
[Table 1]

[0059]
Embodiment 2
FIG. 11 is a lens diagram showing an expanded view of the microscope optical system according to the second embodiment. Table 2 shows specific numerical configurations of the microscope optical system according to the second embodiment. The correspondence between the surface number and each optical element is the same as in the first embodiment. Imaging magnification M of relay optical systems 240 and 250 in the second embodiment _R Is -1.5 times.
[0060]
[Table 2]

[0061]
Embodiment 3
FIG. 12 is a lens diagram showing an expanded view of the microscope optical system according to the third embodiment. Table 3 shows specific numerical configurations of the microscope optical system according to the third embodiment. The correspondence between the surface number and each optical element is the same as in the first embodiment. Imaging magnification M of relay optical systems 240 and 250 in Embodiment 3. _R Is -1.875 times.
[0062]
[Table 3]

[0063]
Embodiment 4
FIG. 13 is a lens diagram showing an expanded view of the microscope optical system according to the fourth embodiment. Table 4 shows specific numerical configurations of the microscope optical system according to the fourth embodiment. The correspondence between the surface number and each optical element is the same as in the first embodiment. Imaging magnification M of relay optical systems 240 and 250 in Embodiment 4. _R Is -2.0 times.
[0064]
[Table 4]

[0065]
【The invention's effect】
As described above, according to the stereoscopic microscope of the present invention, the imaging magnification M of the relay optical system that relays the primary image formed by the objective optical system _R And -3 <M _R By setting the range to <-1, the upper and lower limits of the variable focal length of the zoom optical system included in the objective optical system can be shortened, and the size and weight of the zoom optical system having a large number of lenses can be reduced. The size and weight of the microscope can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing the overall configuration of a surgery support system incorporating a stereoscopic microscope according to a first embodiment of the present invention.
FIG. 2 is an optical configuration diagram schematically showing an optical configuration in a stereoscopic microscope.
FIG. 3 is an optical configuration diagram schematically showing an optical configuration of a stereoscopic viewer.
FIG. 4 is a plan view of an LCD panel.
FIG. 5 is an external perspective view of a stereoscopic microscope.
FIG. 6 is a perspective view showing the entire configuration of a microscope optical system.
FIG. 7 is a side view of the microscope optical system shown in FIG. 6;
FIG. 8 is a front view of the microscope optical system shown in FIG. 6;
9 is a plan view of the microscope optical system shown in FIG.
FIG. 10 is a lens diagram showing the imaging optical system of Example 1 in a developed manner.
FIG. 11 is a lens diagram showing a developed imaging optical system according to a second embodiment.
FIG. 12 is a lens diagram showing a developing optical system according to a third embodiment in a developed manner.
FIG. 13 is a lens diagram showing the imaging optical system of Example 4 in a developed manner.
[Explanation of symbols]
102 CCD camera
200 shooting optical system
210 Close-up optical system
220, 230 zoom optical system
240, 250 relay optical system
260 Convergence Approach Prism
270,271 Field stop
272,273 Penta prism
300 illumination optical system
310 illumination lens
320 wedge prism

Claims (3)

A close-up optical system having a single optical axis and arranged opposite to the subject,
It has an optical axis that is parallel to the optical axis of the close-up optical system, and is variable in magnification to form a primary image of the subject at a certain position by subject light that has passed through different places in the close-up optical system. A pair of zoom optics,
A pair of field stops respectively arranged at positions of the primary image formed by the zoom optical system and defining edges of the primary image,
A pair of relay optical systems that relay the primary image to form a secondary image of the subject,
An image sensor that captures a pair of the secondary images,
The imaging magnification M _R of the relay optical system, the following conditions,
-3 _<M R _<-1
A stereoscopic microscope characterized by satisfying the following. An inter-optical axis distance reducing element that brings the subject light from the relay optical system closer to each other between the relay optical system and the image sensor, wherein the image sensor is formed in an adjacent area of a single imaging surface. The stereoscopic microscope according to claim 1, wherein the secondary image is captured. The relay optical system includes, in order from the field stop side, first, second, and third lens groups each having a positive power, and divergent light transmitted through the field stop by the first and second lens groups. 2. The stereoscopic microscope according to claim 1, wherein the light is substantially parallel light, and is converged by the third lens group.

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