JP2008292513A - Variable power optical system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable an observer to directly view an observation object so as to easily perform work to the observation object in a variable power optical system for a stereomicroscope used in an observation device which takes and displays an electronic stereoscopic image so as to perform observation. <P>SOLUTION: The variable power optical system comprises, in order from an object side, an objective optical system, a once-imaging afocal relay optical system, an afocal zoom optical system, a split mirror splitting light into a plurality of luminous fluxes, and imaging optical systems provided respectively for the split luminous fluxes. By moving a lens existing nearer to an image side than an imaging point of the once-imaging afocal relay optical system in order to change an operation distance, a moving mechanism for moving the lens is separated from the observation object, whereby the observation object is directly viewed by the observer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

    The present invention relates to a variable magnification optical system suitable for a stereomicroscope of a stereoscopic image observation apparatus that stereoscopically observes an observation object.

    Stereomicroscopes have been used for microsurgery in a narrow area of an affected part of a patient in an industrial use or in a patient in an operation.

    Recently, in order to further grasp the state of an observation object, it is desired to observe using an invisible light ray such as ultraviolet rays or infrared rays, or to observe a change in faint light using fluorescence.

  For industrial use, to observe the state of dirt on the workpiece, perform fluorescence observation, and for medical use, to distinguish malignant tumors from others, to observe blood vessels that are visible in the back of the skin. Infrared observation is performed.

    In order to perform such observations, an observation object is photographed using an electronic photographing device, and when the observation image is superimposed, the device becomes large, and the observation object is directly viewed when working on the observation object. In addition, there is a problem that the position of looking through the microscope is away from the observation object, and the observer is forced to take an unreasonable posture, which increases the fatigue of the observer.

On the other hand, instead of observing with an optical microscope, an apparatus for taking an electronic image and displaying and observing the image as described in the following document 1 is known.
JP 11-258516 A Japanese Patent Laid-Open No. 4-76514 JP, 2005-49646, A Since the device indicated in the above-mentioned patent documents 1 can separate a photography part and a display part, since the restriction of the position where an observer views a display image is eased, an observer is easy. The display image can be observed in the posture.

    In this apparatus, when an operation such as processing of an observation object or removal of a tumor is added, it is possible to improve the efficiency of the operation of the observation object by minimizing a portion close to the object of the apparatus as much as possible. Furthermore, when performing advanced work, it is necessary for a plurality of people to work on the observation object from different directions at the same time. In such a case, each of the observers almost matches the orientation of the image when directly viewing the display image of the observation object, so that the appearance of the image of the processing tool on the screen matches the movement of the hand, and less fatigue Can observe.

    The apparatus of the above-mentioned Patent Document 1 only gives an image of an observer in one direction, and it is difficult to take an observation image in two or more directions because the routing of the optical path becomes complicated.

    Further, this stereoscopic observation apparatus is desired to be more optimal and have a good three-dimensional effect because the clues that a person can recognize stereoscopically are limited to binocular parallax and convergence.

    For this reason, when an afocal zoom optical system common to the left and right is used, the inward angle changes due to zooming, and the stereoscopic effect changes.

    In order to keep the stereoscopic effect constant, Patent Document 2 has been devised. However, the size of the vicinity of the observer is increased, and the configuration becomes complicated in order to cope with a plurality of observation directions.

    The present invention relates to a variable magnification optical system that is used in an observation apparatus by taking an electronic stereoscopic image, displaying the image, and a variable magnification optical system having a mechanism for changing a working distance with a small change in the working distance due to variable magnification. It is to provide.

    The present invention also provides a variable magnification optical system having a mechanism for keeping the inward angle constant during variable magnification.

    The variable magnification optical system for an electronic image apparatus according to the present invention includes, in order from the object side, one objective lens optical system, one once-imaging afocal relay optical system, one afocal zoom optical system, and at least two An optical system that includes an imaging optical system that captures images with parallax, and moves the lens closer to the image side than the imaging system of the one-time imaging afocal relay optical system in the optical axis direction. It is characterized by changing the working distance.

    By using the optical system configured as described above, it becomes easy to change the parallax direction and to capture a plurality of parallaxes.

    As described above, when performing a work using a stereomicroscope, it is important that it is easy to look directly at the observation object, and it is easy to bring the processing tool or treatment tool that operates on the observation object to the observation object. Therefore, it is desirable to make the part near the observation object of the observation apparatus small.

On the other hand, the performance of the electronic image device has been improved by improving the resolution of the image sensor and improving the color reproduction, and thus the practical application of stereoscopic vision by the electronic image device can be considered.
Humans perform stereoscopic recognition using binocular parallax, convergence, accommodation, and motion parallax.

    Many electronic images are stereoscopically observed by binocular parallax and convergence.

    On the other hand, a stereomicroscope, which is an optical microscope for observing an optical image, can reproduce binocular parallax and accommodation in addition to convergence, so the difference between stereoscopic viewing by an electronic image device is obvious.

    In the work by stereoscopic observation, even if an advanced work is impossible, it is a simple work and the electronic image apparatus can often be used for a work for a short time. However, an apparatus used for such an object must be inexpensive. For this purpose, the configuration must be simplified.

    When a plurality of variable magnification optical systems are used as in a general stereomicroscope, the difference between the left and right images is recognized as three-dimensional information, so the focus position, magnification, and image center must be precisely matched. For that purpose, adjustment work by highly skilled technicians is inevitably required, and the price increases and it does not meet the purpose of making it inexpensively. Therefore, in order to simplify the adjustment, it is preferable to use a single zoom system. When a single zoom system is used, if the distance between the optical axes of the left and right imaging systems is constant, the distance between the optical axes on the incident side changes in proportion to the zoom magnification, and the stereoscopic effect changes.

    In order to compensate for this, a mechanism for correcting the stereoscopic effect to be constant is required. Further, if the left and right apertures are separated from the objective lens, the diameter of the objective lens becomes large and a relay lens is necessary. Therefore, the mechanical mechanism that supports the optical system becomes large, and it is preferable to dispose the optical system as a moving part at a position away from the object.

    Considering this point, the variable magnification optical system for an electronic image stereomicroscope according to the present invention is configured as described above.

    In addition, in the variable magnification optical system used in the stereoscopic image observation apparatus having such a configuration, in order to make the apparatus having a good field of view, it is effective to reduce the diameter of the lens and move the moving part of the optical system to the image side. It is.

    In the optical system described above, in order to reduce the diameter of the lens, it is desirable that the conjugate position of the left and right openings divided into the right and left light beams is in the vicinity of the objective lens. For this purpose, it is necessary to arrange an afocal relay optical system that forms a single image.

    Further, in order to move the lens, a mechanical movement mechanism is required, and the apparatus becomes large.

    Further, in the optical system, zooming and a change in working distance are necessary as the lens or the like needs to be moved.

    Among these, zooming can reduce the size of the objective optical system by disposing the zoom optical system after the afocal relay optical system that forms a single image (on the image side).

    On the other hand, when the lens is moved to change the working distance, in order to avoid an increase in the size of the apparatus, the lens located on the image side from the image forming point of the afocal relay optical system that forms an image once is moved. Good.

    For the above reasons, the optical system of the present invention changes the working distance by moving the lens on the image side from the imaging point of the afocal relay optical system that forms an image once.

    Therefore, the working distance is changed by moving the lens on the image side from the imaging point of the afocal relay optical system of the variable magnification optical system having the above-described configuration of the present invention, or the zoom group on the most object side of the afocal relay optical system is moved. If the working distance is changed by the above, it is possible to reduce the fluctuation of the working distance due to zoom magnification.

    The variable magnification optical system for photographing a three-dimensional electronic image according to the present invention includes at least two connections, one objective lens optical system, one once-imaging afocal relay optical system, and one afocal zoom optical system. And an optical system for adjusting an optical axis distance between the afocal zoom optical system and the imaging optical system (each imaging optical system of the imaging optical system). The mechanism for adjusting the distance between the optical axes is arranged to prevent the change of the inward angle due to the change of the zoom magnification, and the inward angle is kept constant.

    As described above, the optical system of the present invention keeps the change of the inward angle accompanying the change of the zoom magnification constant by the optical axis interval adjusting mechanism. Here, it is desirable that the optical axis interval adjustment mechanism is a movement of the afocal zoom lens in the optical axis direction because the zooming due to the movement of the afocal zoom lens and the movement mechanism of the optical axis interval adjustment mechanism are easily linked.

    Further, when the optical axis interval adjusting mechanism is moved in the optical axis direction of the afocal zoom lens as described above to perform adjustment, the lens on the image side is moved from the imaging point of the afocal relay optical system once. It is desirable because it is easy to work with a mechanism that changes the working distance. As a result, the optical system on the object side can be downsized as described above.

Here, the optical axis interval adjusting mechanism is a light beam splitting mirror that splits the light beam emitted from the afocal zoom optical system into left and right light beams, and the light beam emitted from the afocal zoom optical system for the optical axes of both the divided light beams. When the afocal relay optical system has a magnification of 1 and the afocal zoom optical system has a magnification of βaz, with a configuration including at least a light deflecting member that is parallel to the axial direction. If the movement amount of the light beam splitting mirror is Δx, it is preferable that the inward angle on the object side can be kept constant by satisfying the following condition (1), and there is no change in stereoscopic effect.
(1) Δx = a (βaz−1) / 2βaz
However, Δx is positive in the direction away from the afocal zoom optical system.

    Further, the variable magnification optical system for photographing a three-dimensional electronic image of the present invention includes, in order from the object side, one objective lens optical system, one single-imaging afocal relay optical system, one afocal zoom optical system, and at least An optical system that includes two imaging optical systems and includes an imaging optical system that captures an image with parallax, and includes at least two directions in an afocal light beam between the afocal zoom optical system and the imaging optical system. It is characterized in that a light beam splitting element that splits a light beam that forms an image with parallax is arranged.

    As a result, it was possible to take an image with the line of sight by a plurality of observers.

    In addition, the optical system according to the present invention has an afocal zoom lens that interlocks with zooming so that the inward angle that changes due to zooming is kept constant so that the stereoscopic effect is kept constant. It moves in the direction of the optical axis. In addition, by moving the lens located on the image side from the imaging point of the once-imaging afocal relay optical system in the optical axis direction, the working distance can be changed, so that images of appropriate parallax by a plurality of observers can be obtained. Thus, the object side can be reduced in size, and an observation apparatus with a good field of view can be obtained.

    According to the present invention, by providing a plurality of images having a small object side and different parallax, it is easy for a plurality of observers to add work or treatment to the observed object, and suitable for stereoscopic image shooting that does not change the stereoscopic effect. This has the effect that a variable magnification optical system can be realized.

    Next, embodiments of the variable power optical system for photographing a three-dimensional electronic image of the present invention will be described based on the respective examples shown in the drawings.

    Example 1 of the variable magnification optical system of the present invention has a configuration as shown in FIG.

    In other words, the variable magnification optical system of Example 1 is a zoom optical system including an objective lens optical system 1, an afocal relay optical system including lenses 2, 4, and 6, and three zoom groups of positive, negative, and positive. The system 7 and a photographic optical system constituted by two imaging lenses each consisting of lenses 11L and 11R.

    The prism S bends the optical axis from the objective lens optical system 1 by 45 °, and the prism 8 and the reflecting mirrors 9L and 9R are optical systems that divide the optical path and have an optical axis interval adjusting mechanism.

    In the variable power optical system for photographing a three-dimensional electronic image shown in FIG. 1 according to the first embodiment of the present invention, a light beam from the objective lens optical system 1 is incident on an image forming afocal relay optical system once, and then coupled. An image is formed once at the image point 5 and then emitted as an afocal light beam. The light beam is incident on the afocal zoom optical system 7, and the light beam emitted from the afocal zoom optical system 7 is converted into left and right light beams by a light beam dividing mirror 8. Divide. The left and right light beams are directed in the direction parallel to the extension of the optical axis of the afocal zoom optical system 7 by the left and right mirrors 9L and 9R, pass through the left and right stops 10L and 10R, and the left and right imaging lenses 11L and An image is formed on the imaging surfaces of the imaging elements 12L and 12R such as a CCD, a CMOS, and an imaging tube by 11R, and is photographed by these imaging elements 12L and 12R.

    In the variable magnification optical system for photographing a three-dimensional electronic image of the first embodiment, the objective lens optical system 1 may be a fixed focus, but it is preferable to move a part or the whole of the objective lens because the working distance changes. However, an increase in size due to a mechanical mechanism that moves the objective lens is a problem.

    The objective lens of Example 1 is composed of a concave lens and a convex lens, and the diameter of the concave lens can be reduced. Therefore, by moving the concave lens, a mechanism for movement is utilized using the difference in diameter between the convex lens and the concave lens. Accordingly, the concave lens can be moved without increasing the size of the lens barrel of the objective lens.

    As described above, the variable power optical system of Embodiment 1 can change the working distance by moving one lens of the objective lens optical system. In addition, an objective lens system that can reduce the diameter of the moving lens as described above is possible, and therefore it is possible to realize a stereoscopic image capturing apparatus that allows an observer to easily view an observation object. Can be achieved.

    However, in the variable power optical system of the first embodiment, the working distance can be changed by the lens on the image side from the imaging point of the one-time imaging afocal relay optical system, that is, the lens 6.

    Next, an afocal relay optical system that forms a single image is composed of a lens 2, a lens 4, and a lens 6. In order to reduce the size of the photographing variable power optical system, it is preferable to reduce the diameter of the one-time imaging afocal relay optical system. For this purpose, it is desirable to set the afocal magnification to a value close to 1.

    In the first embodiment (in the present invention), the afocal magnification β is set within the following range.

0.9 ≦ β ≦ 1.1
If β is within the above range, the difference is not so great and there is no practical problem.

    When the afocal magnification β is smaller than the lower limit value 0.9 of the above condition, the image side lens becomes larger, and when the afocal magnification β is larger than the upper limit value 1.1, the object side lens becomes larger. Therefore, the apparatus becomes large in any case. In particular, if β = 1, the maximum diameter of the lenses of the objective lens optical system 1 to the afocal zoom optical system can be reduced.

    Further, by arranging the lens 4 of the once-imaging afocal relay optical system near the imaging point 5, it is easy to correct off-axis aberrations.

    The reflecting member 3 is for reflecting the light beam in a direction of 45 ° with respect to the observation object plane. The observer can use the stereoscopic image to the stereoscopic viewer, head mounted display (HMD), stereoscopic monitor, etc. This is for facilitating the observation. It is preferable that the distance between the observer's peeking position and the observation object is closer to the observation object because the workability is better. In addition, it is desirable that tools and treatment tools do not collide with the imaging device. Therefore, in Example 1, the optical axis of the objective lens optical system and the optical axis of the one-time imaging afocal relay optical system are inclined by 45 °.

    FIG. 2 is a view seen by an observer. A stereoscopic image is displayed on one display surface, and separate display elements are used on the left and right sides due to interference between the stereoscopic monitor 14 and the stereoscopic observation device 13 due to an image change depending on the viewing direction. However, compared with the stereoscopic viewer 15 that looks into the image with the left and right lenses, it is easier to block the observation image.

    Here, if the angle formed by the optical axis of the objective lens optical system and the optical axis of the one-time imaging relay optical system is θ, an observation image on the stereoscopic viewer 15 indicates that θ is within the following range. It is easy to see and can improve workability.

20 ° ≦ θ ≦ 70 °
In the case of observation on the stereoscopic monitor 14, θ is preferably within the following range.

20 ° ≦ θ ≦ 50 °
In any case, when the angle θ is smaller than the lower limit value of 20 °, the tool or the treatment instrument easily interferes with the imaging apparatus. If θ is larger than the upper limit of 70 ° or 50 °, interference with the stereoscopic display device is likely to occur or the display image is likely to be blocked.

    Next, the afocal light beam emitted from the one-time imaging afocal relay optical system enters the afocal zoom optical system 7. The afocal zoom optical system 7 changes the incident light flux and emits an afocal light flux. This light beam is split into left and right light beams by the light beam splitting prism 8. The divided light flux becomes a light flux parallel to the extension of the optical axis of the afocal zoom optical system 7 by the mirrors 9L and 9R. Of the light beams divided into left and right, the optical system and optical element for the image for the left eye are indicated by L after the reference numeral, and the optical system and optical element for the image for the right eye are indicated by R after the reference numeral.

    The light beams reflected by the mirrors 9L and 9R are decentered from the optical axis of the afocal zoom optical system 7, and aperture stops 10L and 10R whose conjugate positions are targeted with respect to the optical axis are arranged. Imaging lenses 11L and 11R for forming an afocal beam after passing through the aperture stops 10L and 10R are arranged. Images formed by the imaging lenses 11L and 11R are picked up by image pickup devices 12L and 12R such as a CCD, a CMOS, and a pickup tube.

    FIG. 3 shows a configuration from the afocal zoom optical system 7 to the image sensors 12L and 12R. By projecting the aperture stop in the vicinity of the objective lens optical system by the afocal zoom optical system 7, the maximum diameters of all the lens systems can be reduced. However, in the zoom optical system, the pupil position varies due to zooming. In order to reduce the fluctuation of the pupil position of the zoom lens system, a lens may be disposed near the pupil position. Therefore, it is desirable that the optical system of the first embodiment is configured by a three-group zoom, and the third zoom group 7C close to the aperture stops 10L and 10R is fixed during zooming.

    In addition, when the light beam splitting mirror 8 is fixed, the stereoscopic effect changes due to the magnification of the afocal zoom optical system. For this reason, it is conceivable to limit the zoom magnification to a range where the change in stereoscopic effect does not become a problem. On the other hand, when more advanced work is applied to the observation object, it is necessary to increase the zoom magnification. Therefore, it is necessary to move the light splitting mirror 8 with the magnification of the afocal zoom optical system 7. In that case, when the magnification of the afocal zoom optical system is 1, the left and right light beams pass through the left and right apertures 10L and 10R, respectively, and the observation optical axis passing through the center of the image formed on the image sensors 11L and 11R is the afocal zoom optical system. When the distance between the optical axes of the light beam entering or exiting the system 7 is a, and the afocal zoom magnification of the afocal zoom optical system is βaz, the movement amount Δx of the light splitting mirror 8 at that time is the following condition (1) It is desirable that However, Δx is positive in the direction in which the light splitting mirror moves away from the afocal zoom optical system 7.

(1) Δx = a (βaz−1) / 2βaz
In this case, the movement curves for the first group 7a and the second group 7b of the afocal zoom optical system and the movement curve for making the object-side inward angle constant by the movement of the beam splitting mirror at that time are as shown in FIG. Moving. That is, when the first group 7a and the second group 7b move as indicated by the movement curves 16 and 17 in FIG. 3, the light splitting mirror 8 moves as indicated by the movement curve 18. As a result, the inward angle during zooming is kept constant.

    In Example 1, the afocal zoom optical system 7 and the light splitting mirror 8 are arranged close to each other, and the moving direction of the lens group of the afocal zoom optical system and the moving direction of the light splitting mirror at the time of zooming are the same. Therefore, the movement of the light splitting mirror 8 is the same as when the number of movable groups in the afocal zoom optical system is increased by one. The movement of the mechanism for integrating the feeling is integrated, and the mechanical mechanism is not increased in size and can be a simple mechanism.

    Further, as shown in FIG. 4, the arrangement of the imaging device 20 differs depending on the difference of the observer's arm. Thus, even if the arrangement position of the imaging device 20 is different, when the observation object 21 is viewed on the display device 22, the left and right images 23L and 23R need to appear as illustrated.

In general, a stereoscopic apparatus that captures two images has two optical systems on the image side of the objective lens optical system. Therefore, when the shooting direction is changed, the entire rear side of the objective lens is moved or the image side of the objective lens is moved to the image side. Insert an image rotator and rotate it.
In any case, in a general stereoscopic apparatus that captures two images, the tip becomes large, and further, the rotating part becomes large, which causes a problem in strength.

    The variable magnification optical system for photographing a three-dimensional electronic image according to the first embodiment integrates the light beam splitting mirror 8 to the imaging elements 12L and 12R, and rotates the optical axis of the afocal zoom optical system 7 as the rotation axis, thereby obtaining an image 23L. , 23R. In this case, since the light splitting mirror 8 that moves in conjunction with the afocal zoom optical system 7 is also moved, there is a problem that it is difficult to configure.

    In consideration of this point, the afocal zoom optical system 7 to the optical elements 12L and 12R are integrated, and the optical axis of the afocal zoom optical system 7 is rotated about the rotation axis so as to match the image. desirable.

    In this case, the moving part becomes large, but since this part is farthest from the object surface, even if the part becomes slightly larger, the workability to the observation part is not significantly affected.

    In this embodiment, the working distance is changed by moving the lens of the objective lens optical system by reducing the lens diameter of the objective lens optical system of the variable magnification optical system of the first embodiment. This is an embodiment characterized in that the inward angle is kept constant by moving the beam splitting mirror of the optical axis interval adjusting mechanism based on conditions in conjunction with zooming by the optical system.

    As described above, the first embodiment is a variable power optical system that can change the working distance in the means that can achieve the object of the present invention by moving one lens of the objective lens optical system. The above configuration and means have been described.

    However, as described above, the first embodiment is an embodiment in which the working distance can be changed by moving the lens 6 of the one-time imaging afocal relay optical system, and has the above-described features of the present invention. It is.

    The variable power optical system for photographing a three-dimensional electronic image according to the second embodiment of the present invention has a configuration as shown in FIG. In the second embodiment, as shown in FIG. 5, in order from the object side, a fixed objective lens optical system 24 that converts a light beam from an observation object into an afocal light beam, and an afocal light beam emitted from the objective lens optical system 24. An afocal relay optical system (25, 27, 29) that emits as an afocal light beam after imaging 28 once, and an afocal zoom optical system 7 disposed after the afocal relay optical system (25, 27, 29) A splitting prism 30 that splits the light beam emitted from the afocal zoom optical system into four light beams, an aperture stop 31 mL, 31 mR, 31 sL, 31 sR arranged in each of the split light beams, and an imaging lens 33 mL, 33 mR , 33 sL, 33 sR and imaging devices 34 mL, 34 mR, 34 sL, 34 sR.

    A prism 26 is disposed between the lens 25 and the lens 27 of the afocal relay optical system to deflect the optical path by 45 ° with respect to the optical axis direction of the objective lens optical system 24.

    In the second embodiment, the basic configuration of the optical system from the objective lens optical system 24 to the zoom relay optical system 7 is composed of a single lens 24 having a fixed objective lens optical system. This is the same as the first embodiment except that the working distance is changed by moving the lens 29 along the optical axis.

    However, the second embodiment is different from the first embodiment in that the light beam emitted from the afocal zoom optical system 7 is divided into four light beams by the light beam splitting prism 30 as shown in FIG. Accordingly, the light beams after passing through the aperture stop are reflected by the reflecting mirrors 32 mL, 32 mR, 32 sL, and 32 sR, respectively, and become four light beams parallel to the optical axis of the afocal zoom optical system, respectively. , 33 mR, 33 sL, and 33 sR, images are formed on the imaging surfaces of the imaging devices 34 mL, 34 mR, 34 sL, and 34 sR, and are imaged.

    Here, a line connecting the aperture stop and the center of the imaging surface becomes the imaging optical axis, and this imaging optical axis intersects in the object plane. The angle formed is parallax, and stereoscopic observation is performed. Note that m and s such as mirrors 32 mL, 32 mR, 32 sL, 32 sR, imaging lenses 33 mL, 33 mR, 33 sL, 33 sR, and image sensors 34 mL, 34 mR, 34 sL, 34 sR indicate a main observer and a sub-observer, respectively.

    In FIG. 5, only the main observer side is shown and the secondary observer side is omitted, but the secondary observer optical system is the light of the afocal zoom optical system. A similar structure is obtained by rotating the shaft by 90 °. In FIG. 6, when the aperture stop is entered, elements and the like overlap and it is difficult to recognize the arrangement, so the aperture stop is omitted.

    FIG. 7 shows an observation state by the variable magnification optical system of Example 2. As shown in FIG. 7, when the observation object 36 is photographed by the photographing apparatus including the variable magnification optical system according to the second embodiment, an image is formed on the image sensor as shown in the figure. That is, the main observer 37 observes the left and right images (39L, 39R) on the stereoscopic display device 38 for the main observer. On the other hand, the sub-observer 40 observes the left and right images (42L, 42R) displayed on the sub-observer stereoscopic display device 41.

    Also in the second embodiment, when the light beam splitting mirror 30 is fixed, the stereoscopic effect changes due to the magnification of the afocal zoom optical system. Therefore, it is necessary to move the light splitting mirror 30 with the magnification of the afocal zoom optical system 7. In this case, when the magnification of the afocal zoom optical system is 1, the left and right light beams pass through the left and right apertures 31 mL and 31 mR, respectively, and the observation optical axis passing through the center of the image formed on the imaging devices 34 mL and 34 mR is the afocal zoom optical system. When the distance between the optical axes of the light beam entering or exiting the system 7 is a, and the afocal zoom magnification of the afocal zoom optical system is βaz, the movement amount Δx of the light splitting mirror 30 at that time is the following condition (1) It is desirable that However, Δx is positive in the direction in which the light splitting mirror moves away from the afocal zoom optical system 7.

(1) Δx = a (βaz−1) / 2βaz
Thus, the orientation of the object 36 when the observers 37 and 40 directly observe the observation object 36, and the images 39L and 39R displayed on the stereoscopic display device and the images 42L and 42R observed by the sub-observer are almost the same. Work easily.

    Further, like the variable magnification optical system of the first embodiment, the afocal zoom optical system 7 to the imaging elements 34mL, 34mR, 34sL, and 34sR are integrated, and the optical axis of the afocal zoom optical system is rotated as the rotation axis. The image of the main observer is aligned. In this case, the sub-observer does not coincide with the ideal image orientation, but if the work content is such that the main observation work is assisted or simple assistance is performed without performing fine work, the sub-viewer is viewed from a right angle direction. It can be said that the orientation of the image is sufficiently practical even in observation.

    In the second embodiment, focusing is performed by moving the lens 29 closer to the image side than the image forming point 28 of the image forming afocal relay optical system in the optical axis direction. In this case, since it is not necessary to move the optical system at the tip, the mechanical structure is simplified, and the size on the object side can be reduced even when the spread of the light flux due to the movement of the lens 29 due to the focusing is taken into consideration. It is difficult for tools or the like to collide with the observation apparatus, and it is easy to look directly at the observation object.

    The third embodiment of the present invention has a configuration as shown in FIG.

    Example 3 is an optical system including an illumination system in the variable magnification optical system of the present invention. Therefore, first, the configuration of the illumination system will be briefly described.

    In this illumination system, as shown in FIG. 8, the illumination light emitted from the exit surface of the light guide 43 is caused by the illumination lens 44 in the direction perpendicular to the exit end surface of the light guide 43 near the center of the focus range of the imaging device. It is condensed as light. That is, the illumination light transmitted through the illumination lens 44 is deflected by the mirror 45 and reflected by the half mirror 46 so as to overlap the light flux range of the photographing optical system (variable magnification optical system) to illuminate the observation object.

    Next, a variable magnification optical system according to Example 3 of the present invention will be described.

    The zoom optical system for photographing a three-dimensional electronic image according to the third embodiment forms an objective lens optical system 47 that emits a light beam from the object side as an afocal light beam, and an afocal light beam emitted from the objective lens optical system (50). ) A relay imaging optical system 48 and a relay collimating lens 51 that emits a once-imaged light beam as an afocal light beam, and a three-image group (zoom group). The afocal zoom optical system 52, the light beam 8-dividing mirror 53 that divides the light beam emitted from the afocal zoom optical system 52, and the aperture stops 54 mL and 54 mR arranged in each of the divided light beams are divided. Reflective mirror 55 mL that directs each light beam parallel to the optical axis of the afocal zoom optical system, and an imaging lens 57 mL that forms an image of each light beam divided with 55 mR, 7mR become more.

    The variable power optical system of the third embodiment has the above-described configuration, and as shown in FIG. 8, the afocal light beam after exiting the objective lens forms a single imaging afocal relay optical system. An image is formed at the image point 50 by the system 48, and the image forming afocal optical system is emitted once as an afocal light beam by the relay system collimator optical system 51. In this third embodiment as well, in order to make it difficult for the observer to block the observation of the display image of the display device that displays the photographed image, the relay system imaging optics of the one-time imaging afocal relay optical system as in the first and second embodiments. A prism 49 is arranged between the system 48 and the imaging point 50 to angle the light beam.

    Next, the light beam emitted from the once-imaging afocal optical system is incident on an afocal zoom optical system 52 including three zoom groups 52a, 52b, and 52c, and afocal magnification is performed to emit an afocal light beam. To do. The emitted afocal light beam is divided into eight directions by the light beam eight-dividing mirror 53, and becomes eight light beams symmetrical to the optical axis of the afocal zoom optical system. Each of the divided light beams forms an image on the image sensors 57 mL and 57 mR by the imaging lenses 56 mL and 56 mR.

    The third embodiment is a variable magnification optical system for photographing a three-dimensional electronic image having the above basic configuration, and the basic configuration is substantially the same as the first and second embodiments.

    In addition, the stereoscopic effect can be prevented from changing by moving the light beam dividing mirror 53 so as to satisfy the expression (1) in conjunction with zooming (movement of the zoom group) by the afocal zoom optical system. The point is the same as in the first and second embodiments.

    Note that the movement of the zoom group and the movement of the beam splitting mirror for zooming at this time are as shown in FIG.

    However, in Example 3, the light beam splitting prism is a light beam splitting eight beam prism, and thus the afocal light beam emitted from the afocal zoom optical system has eight directions symmetrical with respect to the optical axis of the afocal zoom optical system. This is different from the first and second embodiments in that it is divided into two.

Here, the light beams split in eight directions by the light beam splitting mirror 53 form four combinations by two light beams symmetrical to the optical axis of the afocal zoom optical system. One combination of light beams symmetric with respect to the optical axis forms a parallax image in one direction. In this way, four-direction parallax images are formed by four combinations of symmetrical light beams.
FIG. 8 shows only the configuration for the main observer in one direction.

    In the third embodiment, the light beam that has been divided into eight by the light beam eight-dividing mirror will be described with reference to FIG.

    Of the light beams divided into eight by the light beam eight-divided mirror, one set forms a captured image for observing the observation object by the main observer, and the other set is a plurality of sub-observers (in this embodiment 3). The three sub-observers) form a captured image for observing the observation object. Therefore, the third embodiment is different from the first and second embodiments in that the observation object can be observed and manipulated by the three other observers in addition to the main observer.

    Therefore, the divided light flux, the optical system, the optical element, and the like are shown with m on the main observer side and s1, s2, and s3 on the sub-observer side, respectively.

    In the variable magnification optical system according to the third embodiment, the light beams divided by the light beam 8-dividing mirror 53 are, as shown in FIGS. 9 and 10, aperture stops 54 mL, 54 mR, 54 s 1 L, and 54 s 1 R arranged in each light beam. , 54s2L, 54s2R, 54s3L, 54s3R, reflected by mirrors 55mL, 55mR, 55s1L, 55s1R, 55s2L, 55s2R, 55s3L, and 55s3R, and reflected in the direction of a specific angle with respect to the optical axis direction of the afocal zoom optical system. The In the third embodiment, the angle is 0 °, and each light beam travels parallel (symmetric) to the optical axis so that the apparatus can be downsized.

    Further, in FIG. 9, the aperture stops 54 mL, 54 mR, 54 s 1 L, 54 s 1 R, 54 s 2 L, 54 s 2 R, 54 s 3 L, and 54 s 3 R are not shown in order to avoid obfuscation of the configuration.

    As described above, the afocal zoom optical system 52 includes the first zoom group 52a, the second zoom group 52b, and the third zoom group 52c, and the first zoom group 52a and the second zoom group 52b are indicated by arrows. The zoom is moved and zoomed, and at the same time, the 8-divided mirror is moved as shown by the arrow and so as to satisfy the above formula (1). As a result, the inward angle is kept constant and the stereoscopic effect is kept constant.

    Here, the aperture stops 54 mL, 54 mR, 54 s 1 L, 54 s 1 R, 54 s 2 L, 54 s 2 R, 54 s 3 L, and 54 s 3 R viewed from the afocal relay optical system side are as shown in FIG. Here, the solid line indicates the low magnification, and the broken line indicates the high magnification. The conjugate position of these aperture stops 54 mL, 54 mR, 54 s 1 L, 54 s 1 R, 54 s 2 L, 54 s 2 R, 54 s 3 L, and 54 s 3 R is set near the objective lens by a one-time imaging afocal relay optical system.

    Next, the light beams reflected by the mirrors 55 mL, 55 mR, 55 s 1 L, 55 s 1 R, 55 s 2 L, 55 s 2 R, 55 s 3 L, 55 s 3 R are respectively reflected by the imaging lenses 56 mL, 56 mR, 56 s 1 L, 56 s 1 R, 56 s 2 L, 56 s 2 R, 56 s 3 L, and 56 s 3 R. An image is formed on the imaging surface.

    That is, an image for the subject is formed on the imaging surface of the imaging elements 57 mL and 57 mR for the main observer by the imaging lenses 56 mL and 56 mR. On the other hand, each image sensor for sub-observation may be arranged, and the image sensor may be arranged at the image position for the sub-observer formed by each imaging lens 56s1L, 56s2R, 56s3L, 56s3R. The number of devices increases, the cost increases, the weight of the device increases, and the operability also deteriorates.

    Therefore, in the third embodiment, as shown in FIG. 11, imaging elements 57sL and 57sR that capture images for two left and right sub-observers are arranged, and these image elements 57sL and 57sR are integrated into an afocal zoom optical system. The observation direction of the sub-observer is changed by rotating the optical axis as a rotation axis. Alternatively, the left and right imaging lenses for sub-observation and the left and right imaging elements may be arranged at the image position of the imaging lens, and the observation direction may be switched as a unit. In this case, since the moving part is large, considering the strength, the size and weight are increased, and the operability is likely to deteriorate.

    In Example 3, when the objective lens optical system and the optical axis of the illumination system are coaxial, even if a deep part such as a hole is observed, there is no shadow and good observation is possible.

    In this apparatus, by shortening the distance from the object to the prism 49 the most, the workability on the object side and the stereoscopic display device are easy to see and effective.

    In order to shorten this portion, it is desirable to fix the objective lens optical system 47 and the relay imaging optical system 48 in the one-time imaging afocal relay optical system and reduce the thickness of these lenses. Therefore, it can be considered that each of these lenses is a doublet. In this case, in order to maintain the performance of the once-imaging afocal relay optical system, it is desirable that the relay collimator optical system 51 corrects aberrations including the aberrations of the objective lens optical system 47 and the relay imaging optical system 48. . In this case, the number of lenses of the relay collimator optical system 51 increases. In that case, as in the second embodiment, when focusing is performed by the relay collimator moving the optical system, the optical system having a large number of lenses is moved, the moving part becomes large, and the size of the apparatus is increased. Problems such as an increase in weight occur.

    In order to solve this problem, it is desirable to perform focusing by moving the first zoom group 52a of the afocal zoom optical system in the optical axis direction. Since the first zoom group 52a can have a relatively small number of lenses and is located away from the observation object, a slight increase in size is not a problem.

    As for focusing in the variable magnification optical system of the present invention, as described in Patent Document 3, a light beam is divided by a half mirror, and an image sensor is arranged at a different focus position in each light beam. It is possible to apply a display method. As a result, since the human eye adjustment function can be used, it is easy to obtain three-dimensional information on a smooth surface, and fatigue during observation can be reduced. In this case, the difference between the imaging positions is preferably not so large and is preferably about the depth of focus.

    The variable magnification optical system of the present invention is an optical system used in a stereoscopic image observation apparatus capable of observing an observation object three-dimensionally with an electronic image, and is changed by moving an image side lens to change the working distance. Along with the movement of the group of afocal zoom optical systems for magnification, the moving mechanism is moved away from the observation object, making it easier for the main observer and the sub-observer to see the observation object directly, and stereoscopic observation and direct observation with stereoscopic images Made it easier to work on objects.

The figure which shows the structure of Example 1 of this invention. The figure of the observation image seen from the observer in Example 1 FIG. 10 is a diagram illustrating a change in the optical axis interval due to the movement of the group and the movement of the beam splitting mirror during zooming of the afocal zoom optical system in the first embodiment. The figure which shows the appearance state etc. of the observation object and left and right observation image in Example 1 The figure which shows the structure of Example 2 of this invention. The figure which shows the light beam after the division | segmentation by the light beam splitting mirror in Example 2 The figure which shows the observation object by the observation object in Example 2, a main observer, and a sub-observer The figure which shows the structure of Example 3 of this invention. The figure shown about the light beam divided | segmented by the light beam 8 division | segmentation mirror in Example 3 The figure which shows the aperture stop of the divided | segmented light beam on the light beam 8 division | segmentation mirror in Example 3 In Example 3, it is a figure which shows the example which formed only the left-right image of the main observer and the sub-observer, and enabled the left-right image of the sub-observer to move.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Objective lens optical system 2, 4, 6 1 time imaging afocal relay optical system 3 Reflecting member for light beam deflection 7 Afocal zoom optical system 8 Light beam splitting mirror 9L, 9R Reflecting mirror 10L, 11R Aperture 11L, 11R Imaging lens 12L, 12R image sensor

Claims (10)

In order from the object side, an objective lens optical system, a single imaging afocal relay optical system, a single afocal zoom optical system, and at least two imaging optical systems are used to generate an image with parallax. An optical system including a photographing optical system for photographing, and the working distance is changed by moving a lens located on the image side from the imaging point of the one-time imaging afocal relay optical system in the direction of the optical system. A variable magnification optical system characterized by 2. The variable magnification optical system according to claim 1, wherein the working distance is changed by moving a lens in the one-time imaging afocal optical system in the optical axis direction. 2. The variable magnification optical system according to claim 1, wherein the working distance is changed by moving a lens unit closest to the object side of the afocal zoom optical system in the optical axis direction. In order from the object side, one objective lens optical system, one one-time imaging afocal relay optical system, one afocal zoom optical system, an optical axis interval adjustment mechanism, and at least two imaging optical systems, And a photographing optical system for photographing an image with parallax, wherein the optical axis interval adjusting mechanism moves so as to keep the inward angle constant in conjunction with a change in magnification of the afocal zoom optical system. Variable magnification optical system. The optical axis interval adjusting mechanism includes at least a light beam splitting mirror for splitting the light beam emitted from the afocal zoom optical system into at least two light beams, and image formation when the afocal magnification of the afocal zoom optical system is 1 5. The following condition is satisfied, where a is an optical axis interval of the optical system and a movement amount of the beam splitting mirror is Δx when the afocal magnification of the afocal zoom optical system is βaz. Variable magnification optical system.
Δx = a (βaz−1) / 2βaz
However, Δx is positive in the direction away from the afocal zoom optical system. 6. The variable magnification optical system according to claim 4, wherein the movement of the optical axis interval adjusting mechanism is a movement in the optical axis direction of the afocal zoom optical system. 6. The variable magnification optical system according to claim 4, wherein the working distance is changed by moving a lens located on the image side from an image forming point of the one-time image forming afocal relay optical system. In order from the object side, an objective lens optical system, a single imaging afocal relay optical system, a single afocal zoom optical system, and at least two imaging optical systems are used to generate an image with parallax. A variable power optical system comprising: a photographing optical system for photographing; and a light splitting element for separating a light beam in at least two directions in an afocal light beam between the afocal zoom optical system and the photographing optical system . 9. The variable power optical system according to claim 8, wherein the light splitting element moves in the optical axis direction of the afocal zoom optical system in conjunction with zooming so that an inward angle changed by zooming is kept constant. system. 10. The variable magnification optical system according to claim 9, wherein the working distance is changed by moving a lens located on the image side from the image forming point of the one-time image forming afocal relay optical system in the optical axis direction.

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