JP2002196258A - Video microscope - Google Patents

Abstract

(57) [Summary] [Problem] To shoot a subject having a smooth surface,
Provided is a video microscope capable of suppressing formation of a bright spot as a light source image in a captured image of a subject. A video microscope 101 converts a subject image for left and right eyes into a CCD 116 of a high-vision CCD camera 102.
A photographing optical system 200 for forming in the upper left and right regions, and an illumination optical system 3 for irradiating illumination light supplied from the light source device 106 via the light guide 105 toward the subject.
00, a first polarizing plate 1 disposed on the object side of the illumination optical system 300, and a second polarizing plate 2 disposed on the object side of the imaging optical system 200. Illumination light emitted from the illumination optical system 300 via the first polarizing plate 1 is polarized so that only components in a direction orthogonal to the base length direction pass. The light beam regularly reflected on the smooth surface of the subject is
Only the light flux having a polarization direction other than the direction orthogonal to the base length direction passes through the second polarizing plate and reaches the imaging optical system 200.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video microscope which magnifies an illuminated object and outputs the image to a monitor.

[0002]

2. Description of the Related Art An organ such as the brain is difficult to identify with the naked eye because the structure of the tissue constituting the organ is extremely fine. Therefore, when performing a surgical procedure on such an organ, a microscope is generally used.

In recent years, a video microscope has been proposed in which an image formed by a higher-magnification photographing optical system is picked up by an image pickup device and the image is output to a plurality of monitors. According to this video microscope, for example, an anesthesiologist, a resident, a nurse, etc. other than the person in charge of the operation (main operator) can observe the same enlarged image as the main operator via the monitor. Therefore, at the operation site, a quick and accurate sharing work can be performed.

In such a video-type microscope, when the magnification is increased for more detailed observation, the amount of light incident on the photographing optical system decreases in proportion to the magnification. The subject image becomes dark.
Therefore, a video microscope generally includes an illumination optical system for irradiating illumination light supplied from a light source device to a surface of a subject.

[0005]

When an organ having a relatively dry epithelial tissue surface, such as skin, is photographed by using the above-mentioned video microscope, a microscopic observation of the epithelial tissue surface is performed. Since the illumination light is diffusely reflected by the unevenness, a part of the light flux reflected in various directions at each part of the surface of the epithelial tissue is taken into the imaging optical system. At this time, since the luminous flux from each part of the surface enters the imaging optical system at a uniform level of intensity, a high-brightness part (bright spot) is formed in the captured image of the surface of the epithelial tissue. Not done.

[0006] However, when the above-mentioned video microscope is used to photograph an organ such as the brain in which the surface of epithelial tissue is wet with a body fluid or the like and whose macroscopic surface shape is a set of substantially spherical surfaces, Since the surface of the epithelial tissue becomes mirror-like by being covered with the body fluid, many portions of the irradiated illumination light are specularly reflected at each part of the surface of the epithelial tissue without being diffusely reflected. Therefore, only a part of the light flux slightly diffusely reflected at each part of the surface of the epithelial tissue is taken into the imaging optical system with its intensity being extremely low. Of course, since the macroscopic surface shape is a substantially spherical surface, among the light beams that are regularly reflected on the substantially spherical surface, there are light beams that are regularly reflected toward the imaging optical system.

As described above, when an organ such as the brain is photographed by a video microscope, the intensity of a light beam that is specularly reflected at any point on the substantially spherical surface and taken into the photographing optical system is diffusely reflected at each part of the surface. However, since the intensity of the luminous flux taken into the imaging optical system is extremely high, a high-luminance portion (bright spot) is formed in the captured image of the surface of the epithelial tissue. Was.

Further, as described above, since a plurality of such substantially spherical surfaces exist on the surface of the brain, a bright spot is generated for each substantially spherical portion in the photographed image of the surface of the epithelial tissue. There was also a problem. Note that the bright spot is an image of the light source reflected on the surface of the substantially spherical surface, and the image of the light source is defocused on the imaging surface because the surface acts as a convex mirror.

Further, the brightness of the bright spot often exceeds the allowable value (latency) of the exposure amount of the imaging device. As a result, the bright spots appear white in the image, and the amount of exposure at the bright spots on the imaging surface acts in a direction that lowers the gain for amplification of the image signal, so that the surface of an organ such as the brain can be observed. Would be difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and a problem thereof is that when a subject having a smooth surface is photographed, a light source image is included in the photographed image of the subject. An object of the present invention is to provide a video microscope capable of suppressing formation of a bright spot.

[0011]

SUMMARY OF THE INVENTION A video microscope according to the present invention configured to achieve the above object has a photographing optical system for forming an image of a subject, and an illumination optical system for irradiating the subject with illumination light. An illumination optical system, a first polarizing plate that transmits only a linearly polarized light component in a predetermined direction of the illumination light on an optical path of the illumination optical system, and an imaging optical system on an optical path of the imaging optical system. A second polarizing plate that transmits only a linearly polarized light component in a direction different from the direction of the linearly polarized light component transmitted by the first polarizing plate out of the subject light incident on the system, and is formed by the imaging optical system. An imaging device for imaging a subject image.

With this configuration, when photographing a subject having a smooth surface, the illumination light transmitted through the illumination optical system is polarized by the first polarizing plate as a light beam having only a linear polarization component in a predetermined direction. The luminous flux emitted to the subject and regularly reflected at any point on the surface of the subject is attenuated by the second polarizing plate before passing through the photographing optical system. On the other hand, of the light flux diffused and reflected at each part of the surface of the subject and reflected toward the photographing optical system, a polarized component in the same direction as the polarization direction of the second polarizer is the second polarizer. Through.

As described above, the light beam specularly reflected on the surface of the subject is reduced before entering the photographing optical system, and a predetermined ratio of the diffusely reflected light beam enters the photographing optical system. In an image of a subject formed by the photographing optical system and photographed by the imaging device, generation of a bright spot due to specular reflection at a predetermined position on the surface of the subject is suppressed. Therefore, it is possible to comfortably observe the surface of the subject.

In the video microscope according to the present invention, the photographing optical system may have one objective optical system for monocular observation, or a pair of objective optical systems separated by a predetermined base line length for binocular observation. May be provided.

In the video microscope according to the present invention,
The first and second polarizing plates may be arranged so that the polarizing direction of the first polarizing plate is at 90 ° to the polarizing direction of the second polarizing plate, or at an angle other than 90 °. The first and second polarizing plates may be arranged so as to intersect. In the case where the polarization directions cross each other at 90 ° as in the former case, a light beam that is specularly reflected on the surface of the subject and is going to enter the imaging optical system is completely blocked. Further, when the polarization directions intersect at angles other than 90 ° as in the latter case, the light flux that is specularly reflected on the surface of the subject and is about to enter the imaging optical system is attenuated according to the intersection angle. The light enters the imaging optical system. At this time, in order to observe the surface of the subject more comfortably, the angle at which the polarization directions intersect is from 70 ° to 90 °.
° is desirable.

Further, in the video microscope according to the present invention, one of the polarizing plates is rotatably held around a rotation axis parallel to the optical axis direction, and the crossing angle between the polarizing directions of the first and second polarizing plates is arbitrary. The angle may be selectable.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a video microscope according to the present invention will be described below with reference to the drawings.
In the embodiments described below, the video microscope of the present invention is a video microscope that generates an image that enables stereoscopic observation by capturing an image of a subject formed by a pair of left and right objective optical systems with an imaging device. It is implemented as a stereoscopic microscope. Such a video stereoscopic microscope (hereinafter, simply referred to as “stereoscopic microscope”) is used by being incorporated in, for example, a surgery support system used in neurosurgery. This surgery support system displays a stereoscopic image obtained by video-taking a patient's tissue with a stereoscopic microscope on a stereoscopic viewer dedicated to a main operator or a monitor for other staff, and simultaneously records the image on a recording device. .

<Overall Configuration of Surgery Support System> First, a schematic configuration of a surgery support system as an embodiment of the present invention will be described. 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 stereo microscope 101 and a stereo microscope 10.
HDTV CC mounted near the upper end of the back of 1
A light guide fiber bundle (hereinafter, referred to as a “light guide fiber bundle”) drawn from the upper surfaces of the D camera 102 and the stereo microscope 101
105, this light guide 1
The light source device 106 supplies illumination light to the stereoscopic microscope 101 through the camera 05, the distributor 111 connected to the high-vision CCD camera 102, and the stereoscopic viewer 113, the monitor 114, the recording device 115, and the like connected to the distributor 111. ,It is configured.

The above-mentioned stereo microscope 101 is connected to the first stand 1 via a mount 100b mounted on the back surface thereof.
The free arm 100a is detachably fixed to the distal end of the free arm 100a. Therefore, the stereoscopic microscope 101 is movable within a radius that can reach the tip of the free arm 100a of the first stand 100, and can be oriented in any direction.

The optical configuration inside the stereo microscope 101 will be described in detail later.
The stereo microscope 101 includes an illumination optical system 300 (see FIG. 6) for illuminating a subject with illumination light supplied from a light source device 106 via a light guide 105, and a photographing optical system 200 for forming an image of the illuminated subject. (See FIGS. 6 to 8)
And FIG. 2 shows a schematic configuration of the photographing optical system 200. As shown in FIG. 2, the subject is a large-diameter close-up optical system 21 having a single optical axis.
0 and a pair of left and right zoom optical systems 220 and 230 that converge light transmitted through different portions of the close-up optical system 210, respectively. It is imaged as an image. These left and right primary images are relayed by a pair of left and right relay optical systems 240 and 250 and introduced into the high-definition CCD camera 102, and have a high-definition size (vertical and horizontal aspect ratio = 9: 1).
The image is re-imaged as a secondary image in each of the left and right imaging regions (vertical and horizontal aspect ratio = 9: 8) in the CCD 116 having the imaging surface of 6).

With such an imaging optical system 200, CC
The images formed in the left and right imaging regions on the imaging surface of D116 are equivalent to a stereo image in which images taken respectively from two locations separated by a predetermined base length at a position separated from the subject by a predetermined distance are arranged on the left and right. It is.

The output signal of the CCD 116 is
The image data is transmitted to an image processor 117 connected to the CCD 116, is generated as a high-definition signal by the image processor 117, and is output from the high-definition CCD camera 102 to the distributor 111 as indicated by an arrow in FIG.

The hi-vision signal of the subject image input from the hi-vision CCD camera 102 is distributed by a distributor 111 to a stereoscopic viewer 113 for a main operator, a monitor 114 for other surgical staff, and a recording device 11.
5, respectively.

The stereoscopic viewer 113 is attached so as to hang down from the tip of the free arm 112a of the second stand 112. Therefore, it is possible to arrange the stereoscopic viewer 113 according to a posture in which the main operator easily performs the treatment. This stereoscopic viewer 1
FIG. 3 shows a schematic configuration of the thirteenth embodiment. As shown in FIG.
The stereoscopic viewer 113 is a high-definition size LC
The D panel 120 is built in as a monitor. When an image based on the HDTV signal from the distributor 111 is displayed on the LCD panel 120, as shown in the plan view of FIG.
0a displays an image captured in the left imaging area of the CCD 116, and the right half 1 of the LCD panel 120.
On 20b, an image photographed in the right photographing area of the CCD 116 is displayed.

The optical path in the stereoscopic viewer 113 is LC
A partition wall 121 installed perpendicularly to the display screen along a boundary 120c between the left and right display areas of the D panel 120
Is divided into left and right. On both sides of the partition 121, a wedge prism 119 and an eyepiece 118 are arranged in this 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. Also,
The wedge prism 119 corrects the traveling direction of light so that the angle of convergence 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.

<Outer Shape of Stereo Microscope> Next, the overall shape of the stereo microscope 101 will be described. FIG. 5 is a perspective view of the stereo microscope 101 (including the high-vision CCD camera 102). As shown in FIG.
The housing 1 is formed in a prism shape. More specifically, this housing is formed by chamfering both side edges of a lower right side surface (which is defined as a front surface) in FIG. 5 and a bottom surface (each upper surface) in FIG. And lower surfaces) are formed with circular openings 101a and 101b. As described above, near the upper end of the rear surface of the housing, a high-vision CCD camera 1 is provided.
02 is attached.

An opening 101a on the upper surface of the housing
Has a concave shape, and at the center of the hollow, an insertion opening (not shown) for inserting a guide pipe 122 which is a cylindrical member into which the tip of the light guide 105 is inserted and fixed is formed. ing. The annular member (fiber guide insertion portion) 123 attached to the opening of the insertion opening (not shown) is a chuck for fixing the guide pipe 122 inserted into the insertion opening.

An opening 101b on the lower surface of the housing is provided.
Exposes the object-side surfaces of the close-up optical system 210 and the illumination optical system 300 described above, and passes illumination light guided through the illumination optical system 300 to the outside of the housing. The light passes through the photographing optical system 300 in the housing.

<Optical Configuration of Stereo Microscope> Next, the optical configuration of the stereo microscope 101 will be described in detail with reference to FIGS. FIG. 6 shows a photographing optical system 200 and an illumination optical system 30.
FIG. 7 is a side view showing the optical configuration of No. 0, FIG. 7 is a front view thereof, and FIG. 8 is a plan view thereof. FIG. 9 is a perspective view showing a state of a light beam transmitted through the photographing optical system 200 and the illumination optical system 300.

The stereo microscope 101 is a high-vision CCD.
A photographing optical system 200 for forming a subject image on the CCD 116 of the camera 102, an illumination optical system 300 for irradiating the subject with illumination light supplied from the light source device 106 via the light guide 105, and Illumination optical system 3
The first polarizing plate 1 disposed on the object side of the imaging optical system 200 and the second polarizing plate 2 disposed on the object side of the photographing optical system 200.

As described above, the imaging optical system 200 includes an objective optical system including one close-up optical system 210 and a pair of left and right zoom optical systems 220 and 230 shared by the left and right, and the objective optical system. A pair of left and right relay optical systems 240 and 250 for relaying the formed primary image of the subject to form a secondary image of the subject, and a converging prism 260 for bringing subject light from these relay optical systems 240 and 250 close to each other. And

Field stops 270 and 271 are arranged at positions where the primary images are formed by the zoom optical systems 220 and 230, respectively. A pentaprism 272 and a relay optical system 240 and 250 deflect the optical path at right angles. 273 are respectively arranged.

The optical axes Ax2 and Ax3 of the pair of left and right zoom optical systems 220 and 230 constituting the objective optical system and the optical axis Ax4 of the illumination optical system 300 described later are arranged in the housing of the stereoscopic microscope 101 in the vertical direction of the housing. (Longitudinal direction)
And are provided in parallel. Further, each of the pentaprisms 272 and 27 is
The optical axes of the relay optical systems 240 and 250 and the second lens groups 242 and 252 after the second lens group 252, which are coaxial with each other, are directed in the front-rear direction of the housing of the stereoscopic microscope 101. The optical axes of the two relay optical systems 240 and 250 are shifted in parallel in a direction approaching each other by a convergence approaching prism 260 disposed immediately before the CCD camera 102, so that the inside of the CCD 102 camera (left and right on the imaging surface of the CCD 116). (The center of the imaging area).

With such a configuration, the CCD camera 10
2, two subject images having a predetermined parallax can be formed in each of the left and right imaging regions on the CCD 116 disposed in the CCD 2. In the description of the optical system, “left and right” are directions that match the longitudinal direction of the imaging surface when projected onto 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.

As shown in FIGS. 6 and 7, the close-up optical system 210 includes a negative first lens 21 in order from the object side.
1 and the positive second lens 212 are arranged. The second lens 212 is movable in the optical axis direction, and can focus on objects at different distances by adjusting the movement. That is, the close-up optical system 210
Is adjusted so that the main subject (observation target) is positioned at the object-side focal point, and has a collimating function of converting divergent light from the subject into substantially parallel light.

The first and second lenses 211 and 212 of the close-up optical system 210 have a shape (D-cut shape) in which a part of the edge is cut out along a plane parallel to the optical axis. ing. An illumination optical system 300 having its own optical axis oriented parallel to the optical axis of the close-up optical system 210 is arranged at a position adjacent to the planar cut surface generated by the notch.

The pair of zoom optical systems 220 and 230 image the 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 positive, negative,
First to fourth lens groups 22 each having negative and positive power
6 and 7, and are arranged in the order of first, second, third, and fourth from the close-up optical system 210 side, as shown in FIGS. The first and fourth lens groups 221 and 224 are fixed at the above positions, and the second and third lens groups 222 and 223 are movably held in the optical axis direction. The zooming can be performed by appropriately moving. At this time, the magnification is changed mainly by the movement of the second lens group 222, and the focal position is kept constant by the movement of the third lens group 223.

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 to 234. The second and third lens groups 222, 22 of these zoom optical systems 220, 230
3, 322, 323 are synchronously moved by a drive mechanism (not shown), and can simultaneously change the photographing magnification of the left and right images.

The optical axes of these zoom optical systems 220 and 230
Ax2 and Ax3 are the optical axes Ax1 of the close-up optical system 210.
And a plane including both the optical axes Ax2 and Ax3 sandwiches the optical axis Ax1 of the close-up optical system 210 with a plane including the notch of the D cut.
It is separated from the optical axis Ax1 by Δ.

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. As described above, the zoom optical systems 220 and 2
By setting the optical axes Ax2 and Ax3 of 30 to a position farther from the notch than the optical axis Ax1 of the close-up optical system 210, the illumination optical system 300 can also be accommodated within the diameter occupied by the close-up optical system. , The whole can be compacted.

The field stops 270 and 271 are arranged at the position of the primary image formed by the zoom optical systems 220 and 230 (image-side focal position). This field stop 270, 27
1 has a disk-shaped overall shape, and inside the disk,
A semicircular opening that opens only the right half or the left half is formed. Each of the field stops 270 and 271 is arranged such that the straight edge of the opening is directed to the side corresponding to the boundary line side in the left and right imaging areas on the CCD 116 and transmits only the light flux inside the same. (Fig. 2
, Apertures inside the field stops 270 and 271 are shown in white.) The straight edge of this opening functions as a so-called knife edge, and a single CCD
The secondary images respectively formed in the adjacent areas on the line 116 have boundary lines 120 with the boundaries on the sides adjacent to each other being clear.
Images are captured in the corresponding areas while sandwiching c. Therefore, in the images for the left and right eyes generated by the CCD 116, there is no occurrence of image overlap due to one or both secondary images protruding near the boundary.

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.

As shown in FIGS. 6 and 8, one relay optical system 240 has a first lens group 241 composed of a single positive meniscus lens and a second lens group 242 having a positive power as a whole. And a third lens group 243 composed of a single biconvex lens. The first and second lens groups 241 and 242 have the object-side focal plane as a whole coincident with the image plane of the primary image formed by the zoom optical system 220 (the same plane as the field stop 270). 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 the second lens group 242 and the third
Between the lens group 243 and the lens unit 243, there is a brightness stop 2 for adjusting the amount of light.
44 are arranged.

The other relay optical system 250 also has the same configuration as the above-mentioned relay optical system 240, and is composed of first to third lens groups 251 to 253, and is composed of the first lens group 251 and the second lens group 252. Between them, a pentaprism 273
Are disposed, and the second lens group 252 and the third lens group 253 are provided.
, An aperture stop 254 is arranged.

The divergent light passing through the field stops 270 and 271 is transmitted to the first lens groups 241 and 25 of the relay optical system.
The light is converted into substantially parallel light again by the first and second lens groups 242 and 252, passes through the aperture stop 244 and 254, and is formed again by the third lens group 243 and 253 to form a secondary image. .

Since the pentaprisms 272 and 273 are arranged in the relay optical systems 240 and 250, the optical axes Ax2 and Ax3 of the zoom optical systems 220 and 230 and the optical axes of the relay optical systems 240 and 250 are bent. be able to. Thereby, the optical axis Ax of the close-up optical system 210
The overall length of the imaging optical system 200 in one direction can be configured to be short.

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 240 and 250 to the inside, respectively, so that a predetermined base line length is secured and the same CCD 1 is used.
16 is possible. Relay optical system 24
0, 250 and the CCD camera 102, the convergence approaching prism 260
It has the function of narrowing the interval between the left and right of the subject light from 0,250.

The converging prism 260 is shown in FIGS.
As shown in FIG. 5, the optical axis shift prisms 261 and 262, which are symmetrical with a pentagonal prism, are arranged facing each other with a gap of about 0.1 mm.

As shown in FIG. 8, the optical axis shift prisms 261 and 262 have an entrance end face and an exit end face parallel to each other, and have a first reflection face and a second reflection face parallel to each other inside and outside. Have. Further, these optical axis shift prisms 261 and 262 are provided at the entrance end face, the exit end face, and the first end face.
When a plane perpendicular to the reflecting surface and the second reflecting surface is viewed in a plan view (see FIG. 8), a pentagon formed by cutting one of the acute apex angles of the parallelogram by a line perpendicular to the exit end surface. Shape.

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 first reflecting surface, is directed inward in the left-right direction, and is directed inward. Is reflected again in the same optical axis direction as that at the time of incidence, exits from the exit end face, and enters the high-vision CCD camera 102. As a result, the left and right subject lights are narrowed only in the left and right intervals without changing their traveling directions, and form a secondary image on the same imaging surface of the CCD.

The illumination optical system 300 has a function of irradiating the object with illumination light, and as shown in FIG.
The illumination lens 310 includes an illumination lens 310 for adjusting the degree of divergence of the divergent light emitted from the lens 05 and a wedge prism 320 for matching the center of the illumination range with the center of the imaging range.

As described above, since the optical axis Ax4 of the illumination lens 310 is decentered by a predetermined amount in a state parallel to the optical axis Ax1 of the close-up optical system 210, the center of the illumination range and the center of the photographing range remain unchanged. Do not match, and the amount of illumination light is wasted. However, since the wedge prism 320 is disposed on the exit side, as shown in FIG. 9, the optical axis of the illumination lens 310 is directed to the intersection of the optical axis Ax1 of the close-up optical system 210 and the subject or in the vicinity thereof. be able to. Therefore, the mismatch between the center of the illumination range and the center of the shooting range can be resolved, and the illumination light amount can be used effectively.

As shown in FIGS. 6, 7 and 9, only the component of the incident light beam that vibrates in a predetermined direction is transmitted to the object side of the illumination optical system 300 and the photographing optical system 200. First and second polarizers 1 and 2 as polarizers are provided. The first and second polarizing plates 1 and 2
Is shown in a perspective view of FIG.

As shown in FIGS. 9 and 10, the first polarizing plate 1 provided on the object side of the illumination optical system 300 is formed in a disk shape, and is refracted by the wedge prism 320 toward the optical axis Ax1. It is arranged so as to be orthogonal to the optical axis Ax4 after the operation. The polarization direction is the optical axis Ax2 and the optical axis
It is directed in a direction orthogonal to the plane including Ax3.

On the other hand, the second polarizing plate 2 provided on the object side of the photographing optical system 200 is formed in a rectangular flat plate shape, and extends in a base line length direction orthogonal to both the optical axes Ax2 and Ax3. On the other hand, in a state where the long sides are parallel to each other, the optical axis Ax2 and the optical axis Ax3 (that is, the optical axis Ax of the close-up optical system 210)
It is arranged so as to be orthogonal to 1). Also,
The polarization direction is directed to the above-mentioned base line length direction.
Therefore, the polarization direction of the second polarizing plate 2 is the same as that of the first polarizing plate 1.
90 ° with respect to the polarization direction.

<Operation of Embodiment> Next, the operation of the stereoscopic microscope 101 of the present embodiment having the above-described optical configuration will be described. FIG. 11 is an explanatory diagram illustrating a polarization state of the illumination light IL transmitted through the first polarizing plate 1. The illumination light supplied from the light source device 106 to the illumination optical system 300 via the light guide 105 substantially uniformly includes all the polarization direction components, and is emitted from the illumination optical system 300 to the first polarizing plate 1. Is emitted outside the housing of the stereoscopic microscope 101 as a light flux (illumination light IL) having only a polarization direction component orthogonal to the base line length direction.

When the illumination light IL having only such a polarization direction component is irradiated onto the epithelial tissue of the brain, which is substantially mirror-finished due to the surface being wetted by a body fluid or the like, each part of the surface of the brain becomes , Most of the light flux of the illumination light IL is specularly reflected in a direction symmetric with respect to a normal at the incident position, and the remaining light flux is diffusely reflected in a uniform direction at the position. At this time, a part of the light beam diffusely reflected at each part on the surface of the brain travels toward the entrance pupil of the close-up optical system 210 as subject light OL.

Further, since the brain has a surface shape in which substantially spherical surfaces are macroscopically aggregated, the illumination light can be applied to any substantially spherical surface.
There is a portion inclined in such a direction that the specular reflection direction with respect to the IL is directed toward the entrance pupil of the close-up optical system 210. Therefore, the close-up optical system 2 is used as the subject light OL.
Among the light beams traveling toward the entrance pupil of 10, the light beam emitted from each part of the surface of the brain as a part of the light beam diffusely reflected is extremely high at any point in the substantially spherical portion. The light beam regularly reflected at the reflectance will be included. FIG. 12 shows a state in which the subject light OL enters the photographing optical system 200.

As shown in FIG. 12, the subject light OL is
Before the light enters the close-up optical system 210, the light enters the second polarizing plate 2 disposed on the object side of the close-up optical system 210. At this time, of the subject light OL, only the polarization direction component DR parallel to the base line length direction passes through the second polarizing plate 2 and is captured by the photographing optical system 200 by the CCD 116.
The polarization direction component SR that forms an image on the upper side and is orthogonal to the base line length direction in the subject light OL is blocked by the second polarizing plate 2 and does not reach the close-up optical system 210.

Here, the light beam blocked by the second polarizing plate 2 includes a light beam that is specularly reflected at an extremely high reflectance at any point on the substantially spherical portion of the brain surface. This is because both the optical axes Ax
This is because the light beam traveling along the plane including 1, Ax4 maintains the polarization direction of the first polarizing plate 1 before and after its reflection, and does not include a polarization direction component parallel to the base line length direction.

On the other hand, the luminous flux diffusely reflected on each part of the surface of the subject is twisted by the first polarizing plate 1 when diffusely reflected, so that the polarization direction other than the polarization direction of the first polarizing plate 1 is changed. Will have components. Therefore, when the light beam diffusely reflected by each part of the surface of the subject enters the second polarizing plate 2, only the polarization direction component orthogonal to the polarization direction of the first polarizing plate 1 is extracted and enters the imaging optical system 200. Then, an image is formed by the photographing optical system 200.

As described above, the light beam specularly reflected on the surface of the brain is shielded, and the light beam from each part of the surface enters the photographic optical system 200. In the image generated by the camera 102, a high-brightness portion (bright point) caused by the specularly reflected light flux is not formed.

As a modification of the stereo microscope 101 of the present embodiment described above, the first and second polarizers 1 and 2 are replaced with the first and second polarizers 1 ′ as shown in FIG. , 2 '. The first and second polarizers 1 ′ and 2 ′ as modified examples include first and second polarizers 1 ′ and 2 ′.
Of each polarization direction is 90 °
It is rotated.

More specifically, the polarizing plate 1 ′ is formed in a disk shape, and the optical axis Ax 4 after being bent toward the optical axis Ax 1 by the wedge prism 320 at the rear end of the illumination optical system 300.
Are arranged on the object side of the illumination optical system 300 in a state perpendicular to the object. The polarization direction is directed in a direction parallel to the base length direction orthogonal to the optical axes Ax2 and Ax3.

The polarizing plate 2 ′ is formed in a rectangular shape, and is disposed on the object side of the photographing optical system 200 such that the longer side is parallel to the above-mentioned base line length direction. The polarization direction is directed to a direction orthogonal to a plane including the optical axis Ax2 and the optical axis Ax3. Therefore, the polarization direction of the second polarizing plate 2 forms 90 ° with respect to the polarization direction of the first polarizing plate 1.

Even when the polarization directions of the first and second polarizers 1 ′ and 2 ′ are rotated by 90 ° as in this modification, the illumination light emitted from the illumination optical system 300 is not changed. The light flux transmitted by the first polarizing plate 1 'as a light flux having only a polarization direction component parallel to the base line length direction and traveling to the entrance pupil of the close-up optical system 210 out of the light flux diffusely reflected at each part of the brain surface Of these, only the polarization direction component orthogonal to the base line length direction is transmitted through the second polarizing plate 2 ′, so that the CCD 116 is
Statue on top. Further, a light beam regularly reflected at a high reflectance at any point on the substantially spherical surface on the surface of the brain is blocked by the second polarizing plate 2 '.

As another modified example of the stereoscopic microscope 101 of the present embodiment, the first and second polarizing plates 1 and 2 are
4, the first and second polarizers 1 ″ and 2 ″ are replaced. The first and second polarizers 1 ″ and 2 ″ shown in FIG. 14 correspond to the first and second polarizers 1 and 2 shown in FIG. 10 and the first and second polarizers 1 ′ shown in FIG. , 2 '
As in the above, any polarization direction is not made parallel to the base length direction, but the relative angle of each polarization direction is set to 90 ° with each polarization direction inclined with respect to the base length direction. is there.

As in this modification, even if any polarization direction is not parallel to the base length direction, the illumination optical system 3
The illumination light emitted from 00 is transmitted as linearly polarized light in a predetermined direction by the first polarizing plate 1 ″ and proceeds to the entrance pupil of the close-up optical system 210 of the light flux diffusely reflected at each part of the brain surface. Out of the light flux, only the polarization direction component orthogonal to the polarization direction of the first polarizing plate
Through the polarizing plate 2 ″ of the photographic optical system 200.
Forms an image on the CCD 116. In addition, a light beam regularly reflected at a high reflectance at any point on the substantially spherical surface on the surface of the brain is blocked by the second polarizing plate 2 ″.

In the stereoscopic microscope 101 of the present embodiment, the first and second polarizers 1 and 2 use the illumination optical system 300.
Although it is arranged on the object side of the photographing optical system 200, it can be arranged in the illumination optical system 200 and the photographing optical system 300. For example, as shown in FIG. 15, the first polarizing plate 1 is connected to the entrance side of the illumination optical system 300 and the light guide 105.
15 (position B in FIG. 15), or the second polarizing plate 2 may be disposed in the close-up optical system 210.
15 (position C in FIG. 15) and between the zoom optical systems 220 and 230 and the field stop 27.
0 (position D in FIG. 15) or between the relay optical systems 240 and 250 and the convergence approaching prism 260 (position E in FIG. 15).

As described above, according to the stereoscopic microscope 101 of the present embodiment, the first polarizing plate 1 in the illumination optical system 300 allows only the linearly polarized light component of the illumination light in a predetermined direction to pass therethrough. In the second polarizing plate 2 in the photographing optical system 300, only the linearly polarized light component of the subject light that is different from the polarization direction of the first polarizing plate 1 is transmitted. Therefore, when photographing a subject whose macroscopic surface shape is a set of substantially spherical surfaces such as the brain and the surface of the epithelial tissue becomes mirror-like by being wetted by a body fluid or the like, any one of the substantially spherical surfaces is photographed. At this point, the light beam that is regularly reflected at an extremely high reflectance does not enter the imaging optical system 200. Therefore, it is possible to suppress the occurrence of a bright spot in the image due to the light beam regularly reflected at any point on the substantially spherical surface.

[0072]

As described above, according to the video microscope of the present invention, when a subject having a smooth surface is photographed, a bright spot as a light source image is formed in the photographed subject image. Can be suppressed.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing an outline of a surgery support system including a video stereo microscope which is an embodiment of a video microscope according to the present invention.

FIG. 2 is a schematic diagram showing an optical configuration of a photographing optical system in the video stereo microscope of FIG.

FIG. 3 is a schematic diagram showing an optical configuration of a stereoscopic viewer in the surgery support system of FIG. 1;

FIG. 4 is a plan view of an LCD panel of the stereoscopic viewer of FIG. 3;

FIG. 5 is a perspective view of a video stereo microscope.

FIG. 6 is a side view showing an optical configuration of a photographing optical system and an illumination optical system of the video stereo microscope.

FIG. 7 is a front view of a photographing optical system of the video stereo microscope.

FIG. 8 is a plan view of a photographing optical system of a video stereo microscope.

FIG. 9 is a perspective view showing a state of a light beam transmitted through an imaging optical system and an illumination optical system of a video stereo microscope.

FIG. 10 is a perspective view of first and second polarizing plates of a video stereo microscope.

FIG. 11 is an explanatory diagram showing a state of illumination light emitted from an illumination optical system via a first polarizing plate in a video stereo microscope.

FIG. 12 is an explanatory diagram showing a state of subject light incident on a photographic optical system via a second polarizing plate in a video stereo microscope.

FIG. 13 is a perspective view showing a modification of the first and second polarizers of the video stereo microscope.

FIG. 14 is a perspective view showing another modified example of the first and second polarizing plates of the video stereo microscope.

FIG. 15 is an explanatory diagram showing an example of the arrangement of first and second polarizing plates in an imaging optical system and an illumination optical system of a video stereo microscope.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 first polarizing plate 2 second polarizing plate 101 video stereo microscope 102 high-definition CCD camera 105 light guide fiber bundle 106 light source device 200 shooting optical system 210 close-up optical system 220, 230 zoom optical system 240, 250 relay optical system 260 Convergence shift prism 270, 271 Field stop 272, 273 Penta prism 300 Illumination optical system 310 Illumination lens 320 Wedge prism

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/225 H04N 5/225 C 13/00 13/00

Claims (5)

[Claims] 1. An imaging optical system for forming an image of a subject, an illumination optical system for irradiating the subject with illumination light, and a predetermined direction of the illumination light on an optical path of the illumination optical system. A first polarizing plate that transmits only the linearly polarized light component, and a direction of the linearly polarized light component that is transmitted by the first polarizing plate in the subject light incident on the imaging optical system on the optical path of the imaging optical system. A video microscope comprising: a second polarizing plate that transmits only a linearly polarized light component in a direction different from that of a second polarizing plate; and an imaging device that captures a subject image formed by the imaging optical system. 2. The imaging optical system according to claim 1, further comprising a pair of objective optical systems separated by a predetermined base line length to form left and right images having parallax for binocular observation. Video-type microscope as described. 3. The polarization direction of the first polarizing plate is equal to the second polarization direction.
The video microscope according to claim 1, wherein the microscope is oriented at 90 ° to the polarization direction of the polarizing plate. 4. The apparatus according to claim 1, wherein the first polarizing plate is arranged on the object side of the illumination optical system, and the second polarizing plate is arranged on the object side of the photographing optical system. A video microscope according to claim 1, 2 or 3. 5. The first polarizing plate is disposed so as to be orthogonal to the optical axis of the illumination optical system, and the second polarizing plate is positioned relative to the optical axis of the photographing optical system. The video microscope according to any one of claims 1 to 4, wherein the video microscope is arranged so as to be orthogonal.