JP2018110809A - Microscope for ophthalmology - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microscope for ophthalmology which is suitable for binocular vision and where another optical system can easily be installed.SOLUTION: Inside (6) a microscope for ophthalmology (1), the optical axis (O-400L) of a left-eye observation optical system and the optical axis (O-400R) of a right-eye observation optical system are generally parallel to each other, and the left-eye observation optical system (400L) and the right-eye observation optical system (400R) each comprise an objective lens (401). Each objective lens (401) is made of a lens group of at least a first lens (401a), an optical element (401b) which changes the orientation of an optical axis; and a second lens (401c). The objective lenses (401) change the orientations of the optical axis (O-400L) of the left-eye observation optical system and the optical axis (O-400R) of the right-eye observation optical system to cross each other on a subject-eye side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ophthalmic microscope. More specifically, the present invention relates to an ophthalmic microscope that is capable of correcting residual aberrations, and that the afterimage aberration of an image observed with the left and right eyes is close to the left and right, and is suitable for binocular vision. More specifically, the present invention relates to an ophthalmic microscope in which an objective lens can have a small diameter and another optical system such as an OCT apparatus can be easily installed.

  In the field of ophthalmology, various types of ophthalmic microscopes are used for magnifying and observing the eye. Examples of such an ophthalmic microscope include a fundus camera, a slit lamp microscope, and a surgical microscope. These ophthalmic microscopes have a binocular optical system that provides binocular parallax generated between the left eye and the right eye in order to stereoscopically observe the eye.

A typical conventional ophthalmic microscope is a Galileo stereo microscope. The technical feature of the Galileo stereo microscope is that it has an objective lens that transmits the optical axes of the left and right observation optical systems in common, and that the optical axes of the left and right observation optical systems are basically parallel. It is said. The Galileo stereo microscope has an advantage that it can be easily combined with other optical systems and optical elements.
On the other hand, in the Galileo-type actual microscopic environment, since the objective lens and the imaging optical system are decentered, the residual aberration is reversed in the left and right directions, and it is difficult to reduce the residual aberration.

The present inventors have previously developed an ophthalmic microscope that employs a Greenough-type stereomicroscope, which is a system different from the Galileo stereomicroscope (Patent Documents 1 and 2). The Greenough-type stereomicroscope is a microscope that has two independent observation optical systems on the left and right sides and is arranged so that the optical axes of the left and right observation optical systems intersect. The Greenough-type stereomicroscope does not use a common objective lens, and each of the left and right observation optical systems includes an objective lens.
According to the Greenough-type entity microscopic environment, it is possible to reduce the decentration of the objective lens and the coupling optical system, but there is a problem that the mechanism is complicated because two independent observation optical systems are obliquely crossed. It was.

  By the way, as an inspection apparatus that can be combined with an ophthalmic microscope, there is an OCT (Optical Coherence Tomography) apparatus. The OCT apparatus can be used for acquiring cross-sectional images and three-dimensional images of the eye, measuring the size of the eye tissue (such as retinal thickness), and acquiring functional information of the eye (such as blood flow information).

Many devices that incorporate an OCT device into an ophthalmic microscope have been developed, but most of them are devices in which the optical path of the OCT optical system passes through an objective lens in a Galileo stereomicroscope (Patent Documents 3 to 7). .
In addition, a method has been developed in which the optical path of the OCT optical system does not pass through the objective lens in the Galileo-type actual microscopic environment (Patent Document 8), but the OCT optical system is provided between the objective lens and the eye to be examined.

JP, 2006-185177, A JP, 2006-185178, A JP-A-8-66421 JP 2008-264488 A JP 2008-268852 A Special table 2010-522020 gazette JP 2008-264490 A US Pat. No. 8,366,271

  As schematically shown in FIG. 9A, a Galileo stereo microscope employed in a conventional ophthalmic microscope system includes an optical axis (O400L) of an observation optical system for the left eye and an observation optical system for the right eye. An objective lens (2) through which the optical axis (O400R) transmits in common is provided. The observation optical system for the left and right eyes includes, for example, a variable power lens (402), an eyepiece lens (408), and the like. However, as schematically shown in FIG. 9B, the optical axis (A402) of the variable power lens and the optical axis (A401) of the objective lens are decentered by about 10 to 15 mm. For this reason, it is difficult to correct the residual aberration generated in the left and right eyes. Further, since the residual aberration is generated on the outer peripheral side of the objective lens (2), when the subject (2) is observed with both eyes, as shown in FIG. The left-eye image (V400L) and the right-eye image (V400R) occur on opposite sides, and there is a problem that different images must be observed with the left and right eyes. There are two types of Galilean stereomicroscopes, which have a convergence angle of 0 ° and a non-convergence angle of 0 °, but it is difficult to reduce the residual aberration by correction in either type. It was.

Further, the Galileo stereomicroscope has a demerit that the degree of freedom in optical design and mechanism design is limited because it is necessary to use a large-diameter objective lens.
For example, as shown in Patent Documents 3 to 7, an ophthalmic microscope in which an OCT optical system is incorporated in a Galileo stereomicroscope is a system in which the optical path of the OCT optical system is transmitted through an objective lens in the Galileo stereomicroenvironment. The OCT optical system and the observation optical system could not be made independent.
As a system in which the optical path of the OCT optical system does not pass through the objective lens at the Galileo stereomicroscope, as shown in Patent Document 8, there is a system in which an OCT optical system is provided below the objective lens. There was a problem that sufficient work space could not be secured.

On the other hand, in the Greenough-type stereomicroscope, as shown in FIG. 10A, the optical axis (O400L) of the left-eye observation optical system and the optical axis (O400R) of the right-eye observation optical system are obliquely intersected. The objective lens through which these optical axes are transmitted in common is not provided, and each optical system has an objective lens (401). As shown in FIG. 10B, the optical axis (A402) of the variable power lens and the optical axis (A401) of the objective lens are not decentered, the residual aberration can be corrected, and also occurs in the left and right eyes. There is no technical problem that lateral chromatic aberration and coma occur on the opposite sides of the left and right eyes. Furthermore, since the Greenough type microscopic environment does not use a large-diameter objective lens, an OCT optical system can be provided independently in a space between the left and right observation optical systems.
However, as shown in FIG. 10A, the Greenough-type entity microscopic boundary does not overlap the focus position (Q400L) of the left-eye observation optical system with the focus position (Q400R) of the right-eye observation optical system. As shown in FIG. 10C, there is a problem in that the peripheral focus difference is reversed between the left and right eye images.
In addition, since the Greenough-type stereomicroscope obliquely crosses two independent observation optical systems, it has to be complicated in terms of mechanism, and it is difficult to assemble a variable magnification optical system. It was.

  Therefore, an object of the present invention is to eliminate the technical problems of conventional ophthalmic microscopes, to correct the residual aberration, and to make the residual aberration close to the left and right, so that it can be viewed in both eyes. It is to provide a suitable ophthalmic microscope. Another object of the present invention is to provide an ophthalmic microscope in which the objective lens can be made to have a small diameter and another optical system such as an OCT apparatus can be easily installed.

  As a result of intensive studies, the present inventors have abolished the large-diameter objective lens through which the left and right observation optical systems transmit in common, and provided the objective lens in each of the left and right observation optical systems, thereby decentering the lens. It has been found that the residual aberration can be corrected, and the objective lens can be reduced in diameter, so that another optical system can be easily installed. Furthermore, the present inventors set the objective lens as a lens group having at least a first lens, an optical element that changes the direction of the optical axis, and a second lens, thereby changing the left and right observation optical systems. The present inventors have found that the optical axes can be crossed by the objective lens without crossing, and have completed the present invention. Specifically, the present invention includes the following technical matters.

(1) The present invention provides an observation optical system that includes an illumination optical system that illuminates the eye to be examined, a left-eye observation optical system and a right-eye observation optical system for observing the subject eye illuminated by the illumination optical system. In an ophthalmic microscope equipped with a system,
In the ophthalmic microscope, the optical axis of the left-eye observation optical system and the optical axis of the right-eye observation optical system are substantially parallel,
The left-eye observation optical system and the right-eye observation optical system each have an objective lens,
The objective lens comprises a lens group having at least a first lens, an optical element that changes the direction of the optical axis, and a second lens;
The objective lens changes the direction of the optical axis of the left-eye observation optical system and the direction of the optical axis of the right-eye observation optical system in a direction intersecting with each other on the eye side to be examined.
The present invention relates to an ophthalmic microscope.
(2) In the ophthalmic microscope of the present invention, the optical element that changes the direction of the optical axis is preferably a wedge prism.
(3) In any one of the ophthalmic microscopes, it is preferable that the first lens is a concave lens having a negative power and the second lens is a convex lens having a positive power.
(4) In any one of the ophthalmic mirror microscopes, the first lens, the optical element that changes the direction of the optical axis, and the second lens are arranged in this order from the eye side. If you are
The optical axis of the first lens of the observation optical system for the left eye and the optical axis of the first lens of the observation optical system for the right eye are inclined in a direction intersecting each other on the eye side to be examined. Preferably it is.
(5) In any one of the ophthalmic microscopes, the first lens, the optical element that changes the direction of the optical axis, and the second lens are arranged in this order from the eye side. If you have
The optical axis of the second lens of the observation optical system for the left eye and the optical axis of the second lens of the observation optical system for the right eye are inclined in directions away from each other on the eye side to be examined. It is preferable.
(6) In any one of the ophthalmic microscopes, an optical system other than the observation optical system may be disposed in an intermediate region between the left-eye observation optical system and the right-eye observation optical system.
(7) In the case of (6), it is preferable that the optical system other than the observation optical system is an OCT optical system.

  According to the present invention, it is possible to provide an ophthalmic microscope suitable for binocular vision that can correct residual aberration and has residual aberrations that are nearly equal to the left and right. Further, according to the present invention, there is provided an ophthalmic microscope in which an objective lens, which is an optical component constituting the ophthalmic microscope, can have a small diameter, and another optical system such as an OCT apparatus can be easily installed. Is done.

It is a front view which shows typically the structure of the optical system of the ophthalmic microscope of the 1st Embodiment of this invention. It is a side view which shows typically the structure of the optical system of the ophthalmic microscope of the 1st Embodiment of this invention. It is drawing which shows typically the optical structure of the OCT unit used with the ophthalmic microscope of the 1st Embodiment of this invention. It is sectional drawing which shows typically arrangement | positioning of the optical path in the periphery of the objective lens in the ophthalmic microscope of the 1st Embodiment of this invention. It is a front view which shows typically the optical structure of the objective lens in the ophthalmic microscope of the 1st Embodiment of this invention. FIG. 5A shows the configuration of the objective lens used in the ophthalmic microscope of the first embodiment, and FIG. 5B shows the direction of the optical axis of each lens constituting the objective lens. It is sectional drawing which shows typically arrangement | positioning of the optical path in the periphery of an objective lens in the ophthalmic microscope of 2nd Embodiment of the ophthalmic microscope of this invention, and the ophthalmic microscope of 3rd Embodiment. 6A shows the arrangement of the optical path around the objective lens of the ophthalmic microscope according to the second embodiment, and FIG. 6B shows the optical path around the objective lens of the ophthalmic microscope according to the third embodiment. The arrangement of It is a front view which shows typically the optical structure of the objective lens in the ophthalmic microscope of the 4th Embodiment of this invention. FIG. 7A shows the configuration of the objective lens used in the ophthalmic microscope of the fourth embodiment, and FIG. 7B shows the direction of the optical axis of each lens constituting the objective lens. It is a front view which shows typically the optical structure of the objective lens in the ophthalmic microscope of 5th Embodiment of the ophthalmic microscope of this invention. FIG. 8A shows the configuration of the objective lens used in the ophthalmic microscope of the fifth embodiment, and FIG. 8B shows the direction of the optical axis of each lens constituting the objective lens. It is the schematic diagram which showed the image observed with a right-and-left eye by the Galileo type stereomicroscope which is a prior art, and the said stereomicroscope. FIG. 9A is a schematic diagram showing the configuration of the optical system of the observation optical system for the left and right eyes in the Galileo stereomicroscopic environment, and FIG. 9B shows the light of each lens in the Galileo stereomicroenvironment. FIG. 9C is a schematic diagram illustrating an image observed by the left and right eyes. It is the schematic which showed the image observed with a right-and-left eye with the Greeneau type | mold stereomicroscope which is a prior art, and the said stereomicroscope. FIG. 10A is a schematic diagram showing the configuration of the optical system of the observation optical system for the left and right eyes in the Glee's formula entity micro-environment, and FIG. 10B is a diagram of each lens in the Greenough-type entity micro environment. It is a schematic diagram which shows an optical axis, and FIG.10 (C) is a schematic diagram which shows the elephant observed by the left and right eyes.

1. 1. Ophthalmic microscope 1-1. Overview of the Ophthalmic Microscope of the Present Invention An ophthalmic microscope of the present invention includes an illumination optical system that illuminates a subject eye, a left-eye observation optical system for observing the subject eye illuminated by the illumination optical system, and a right eye The present invention relates to an ophthalmic microscope provided with an observation optical system having an observation optical system.
Since the ophthalmic microscope of the present invention has the objective lens with a small aperture in each of the left-eye observation optical system and the right-eye observation optical system, the left-eye observation optical system and the right-eye observation optical system However, it is not necessary to use a large-diameter objective lens that transmits in common. For this reason, the decentration between the optical axis of the objective lens and the optical axis of the lens in front of it becomes small, and the residual aberration can be corrected. Further, the ophthalmic microscope of the present invention does not require the use of a large-diameter objective lens, and the objective lens can be reduced in diameter, so that another optical system such as an OCT optical system can be easily installed.
The ophthalmic microscope of the present invention uses, as an objective lens, a lens group having at least a first lens, an optical element that changes the direction of the optical axis, and a second lens. With such an objective lens, the orientations of the optical axis of the left-eye observation optical system and the optical axis of the right-eye observation optical system are changed to intersect each other on the eye side. Therefore, the ophthalmic microscope according to the present invention has an optical axis of the left eye observation optical system and the optical axis of the right eye observation optical system which are substantially parallel to each other on the eye side with respect to the objective lens. Two optical axes can be crossed, and it is not necessary to use a complicated mechanism in which the left and right observation optical systems are arranged obliquely as in the case of a Greenough-type stereomicroscope.

In the present invention, the term “ophthalmic microscope” refers to a medical or examination device that can enlarge and observe an eye to be examined, and includes not only humans but also animals. “Ophthalmic microscope” includes, but is not limited to, a fundus camera, a slit lamp, an ophthalmic surgical microscope, and the like.
The ophthalmic microscope of the present invention is used for observing (taking) an enlarged image of an eye to be examined in medical treatment or surgery in the ophthalmic field. The observation target part may be an arbitrary part of the patient's eye. For example, the anterior segment may be a cornea, a corner, a vitreous body, a crystalline lens, a ciliary body, or the like, and the retinal segment may be a retina or choroid. Or a vitreous body. Further, the observation target part may be a peripheral part of the eye such as a eyelid or an eye socket.

The ophthalmic microscope of the present invention can have a function as another ophthalmic apparatus in addition to a function as a microscope for magnifying and observing an eye to be examined. Examples of functions as other ophthalmologic apparatuses include OCT, laser treatment, axial length measurement, refractive power measurement, and higher-order aberration measurement. Other ophthalmologic apparatuses have an arbitrary configuration capable of performing examination, measurement, and imaging of an eye to be examined by an optical method.
The ophthalmic microscope of the present invention can include a control unit for controlling the position and inclination of each lens and a light source, a display unit for displaying a captured image, and the like. These control units and display units may be different from the ophthalmic microscope.

  In the present invention, the “illumination optical system” includes an optical element for illuminating the eye to be examined. The illumination optical system can further include a light source, but it may be one that guides natural light to the eye to be examined.

In the present invention, the “observation optical system” is configured to include an optical element that makes it possible to observe the subject's eye with the return light reflected / scattered by the subject's eye illuminated by the illumination optical system. It is. In the present invention, the observation optical system has a left-eye observation optical system and a right-eye observation optical system. When parallax is generated in an image obtained by the left and right observation optical systems, binocular vision is used. It is also possible to observe three-dimensionally.
In addition, the “observation optical system” of the present invention may be one capable of observing the subject's eye with the naked eye of an observer through an eyepiece, an eyepiece, or the like. It may be possible, or it may have both functions.

  In the present invention, optical elements used in the “illumination optical system” or “observation optical system” are not limited to these, but examples include lenses, prisms, mirrors, optical filters, diaphragms, and diffraction gratings. A polarizing element or the like can be used.

  In the present invention, the optical axis of the observation optical system for the left eye and the optical axis of the observation optical system for the right eye are “substantially parallel” in the ophthalmic microscope. This means that the main path in the microscope is parallel and part of the optical axis may be non-parallel, and if the main path is parallel within a range of 5 ° or less. Good. However, in order to make it easier to arrange the lenses of the optical system, it is preferable to make them as close to 0 ° as possible and to make them parallel, and it is preferable to make them parallel within a range of 3 ° or less.

  In the present invention, the “objective lens” refers to a lens or a lens group provided on the eye side in an ophthalmic microscope. For example, when the objective lens is composed of three lens groups, the third lens from the eye side is the objective lens. When the objective lens is composed of four lens groups, the fourth lens from the eye side is the objective lens. However, the front lens (loupe) that is temporarily inserted between the objective lens and the eye to be examined is not included in the “objective lens” in the present invention.

  In the present invention, the “optical element that changes the direction of the optical axis” may be an optical element that can change the direction of the optical path, and is not limited to these, but the optical path is changed by refraction and reflection. And a wedge prism, or a rhomboid prism that can change the position of the optical axis.

1-2. First Embodiment Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.
1 to 4 are drawings schematically showing a first embodiment which is an example of an ophthalmic microscope of the present invention. FIG. 1 is a front view schematically showing the configuration of the optical system of the ophthalmic microscope according to the first embodiment, and FIG. 2 is a side view of the configuration of the optical system. FIG. 3 is a diagram schematically showing the optical configuration of the OCT unit, and FIG. 4 is a cross-sectional view schematically showing the arrangement of optical paths around the objective lens.

As shown in the front view of FIG. 1, the optical system of the ophthalmic microscope (1) is an observation optical system including an observation optical system (400L) for the left eye of the observer and an observation optical system (400R) for the right eye. And an OCT optical system (500).
Further, as shown in the side view of FIG. 2, the optical system of the ophthalmic microscope (1) further includes an illumination optical system (300). The observation optical system (400) is used for magnifying and observing the eye to be examined (8) illuminated by the illumination optical system (300).
As shown in FIGS. 1 and 2, the observation optical system (400), the OCT optical system (500), and the illumination optical system (300) are housed in an ophthalmic microscope main body (6) indicated by a one-dot chain line. ing.

  In FIG. 1, the optical axis of the observation optical system for the left eye (400L) is indicated by a dotted line (O-400L), and the optical axis of the observation optical system for the right eye (400R) is indicated by a dotted line (O-400R). The optical axis of the OCT optical system is indicated by a dotted line (O-500).

As shown in FIG. 1, the optical axis (O-400L) of the observation optical system for the left eye and the optical axis (O-400R) of the observation optical system for the right eye are within the ophthalmic microscope main body (6). It is parallel.
Therefore, the ophthalmic microscope (1) of the first embodiment does not need to be a complicated mechanism in which the left and right observation optical systems are arranged so as to cross like the Greenough-type stereomicroscope.

As shown in FIG. 1, the left and right observation optical systems (400L, 400R) each have an objective lens (401). The objective lens (401) is an objective lens including a lens group, and includes a first lens (401a), an optical element (401b) that changes the direction of the optical axis, and a second lens (401c). ing.
In the first embodiment, a wedge prism is used as the optical element (401b) that changes the direction of the optical axis, and the base direction is the inside (base-in). The wedge prism changes the directions of the optical axes (O-400L, O-400R) of the left and right observation optical systems in a direction that intersects each other on the eye side.

In the first embodiment, the first lens (401a) is a concave lens having negative power. The optical axes of the left and right first lenses are inclined inward (in a direction intersecting each other on the side of the eye to be examined).
The second lens (401c) is a convex lens having a positive power.

The objective lens (401) used in the ophthalmic microscope according to the first embodiment has a large aperture that allows the optical axes of the left and right observation optical systems to pass through in common, as in the conventional Galileo stereomicroscope. It is not a lens but an objective lens that the left and right observation optical systems have independently. Therefore, as shown in FIG. 1, the objective lens (401) can have a small diameter, and the OCT optical system (500) can be easily installed in the space between the left and right observation optical systems (400L, 400R). can do.
Further, as shown in FIG. 1, the left and right objective lenses (401) change their orientation so that the optical axes (O-400L, O-400R) of the left and right observation optical systems intersect on the eye side to be examined. Therefore, the same part of the eye to be examined can be observed with both eyes with the left and right eyes.

Hereinafter, the ophthalmic microscope according to the first embodiment will be described in more detail.
As shown in FIG. 2, the illumination optical system (300) illuminates the eye to be examined (8), and includes an illumination light source (9), an optical fiber (301), an exit aperture stop (302), a condenser lens ( 303), an illumination field stop (304), a collimating lens (305), and a reflection mirror (306). The optical axes of these illumination optical systems (300) are indicated by dotted lines (O-300) in FIG.

The illumination light source (9) is provided outside the ophthalmic microscope body (6). One end of an optical fiber (301) is connected to the illumination light source (9). The other end of the optical fiber is disposed at a position facing the condenser lens (303) inside the ophthalmic microscope main body (6). The illumination light output from the illumination light source (9) is guided by the optical fiber (301) and enters the condenser lens (303).
An exit aperture stop (302) is provided at a position facing the exit port (fiber end on the condenser lens (303) side) of the optical fiber (301). The exit aperture stop (302) acts to block a partial region of the exit aperture of the optical fiber (301). When the blocking area by the exit aperture stop (302) is changed, the emission area of the illumination light is changed. Thereby, the irradiation angle by the illumination light, that is, the angle formed by the incident direction of the illumination light with respect to the eye to be examined (8) and the optical axis of the objective lens (2) can be changed.

The illumination field stop (304) is provided at a position (x position) optically conjugate with the front focal position (U0) of the objective lens (401). The collimating lens (305) converts the illumination light that has passed through the illumination field stop (304) into a parallel light flux. The reflection mirror (306) reflects the illumination light converted into a parallel light beam by the collimator lens (305) toward the objective lens (2). The reflected light is applied to the eye (8) to be examined.
Illumination light (a part) irradiated to the eye to be examined (8) is reflected and scattered by the tissue of the eye to be examined such as cornea and retina. The reflected / scattered return light (also referred to as “observation light”) enters the observation optical system (400).

As shown in FIG. 1, the left and right observation optical systems (400L, 400R) include an objective lens (401), a variable power lens (402), a beam splitter (403), an imaging lens (404), an image corrector, respectively. It includes an upright prism (405), an eye width adjustment prism (406), a field stop (407), and an eyepiece lens (408). The beam splitter (403) has only the observation optical system (400R) for the right eye.
The variable magnification lens (402) is a lens group including a plurality of zoom lenses (402a, 402b, 402c). Each zoom lens (402a, 402b, 402c) can be moved along the optical axes (O-400L, O-400R) of the left and right observation optical systems by a zoom mechanism (not shown). Thereby, the magnification at the time of observing or photographing the eye to be examined (8) is changed.

As shown in FIG. 1, the beam splitter (403) of the right-eye observation optical system (400R) transmits a part of the observation light guided along the right-eye observation optical path from the eye to be examined (8). Separate and guide to the photographic optical system. The photographing optical system includes an imaging lens (1101) and a television camera (1102).
The television camera (1102) includes an image sensor (1102a). The imaging element (1102a) is configured by, for example, a charge coupled device (CCD) image sensor, a complementary metal oxide semiconductor (CMOS) image sensor, or the like. An image sensor (1102a) having a two-dimensional light receiving surface (area sensor) is used.
When the ophthalmic microscope (1) is used, the light receiving surface of the imaging element (1102a) is disposed at a position optically conjugate with the cornea or retina surface of the eye to be examined (8), for example.

The image erecting prism (405) converts the inverted image into an erect image. The eye width adjustment prism (406) is an optical element for adjusting the distance between the left and right observation optical paths in accordance with the eye width of the observer (the distance between the left eye and the right eye). The field stop (407) is for limiting the observer's field of view by blocking the peripheral region in the cross section of the observation light. The field stop (407) is provided at a position conjugate to the front focal position (U0) (X position) of the objective lens (401).
The observation optical system (400L, 400R) may include a stereo variator configured to be detachable from the optical path of the observation optical system. The stereo variator is an optical axis position changing element for changing the relative position of the optical axes (O-400L, O-400R) of the left and right observation optical systems respectively guided by the left and right variable magnification lens systems (402). is there. For example, the stereo variator is retracted to a retracted position provided on the observer side with respect to the optical path of the observation optical system.

As shown in FIG. 1, when observing the retina of the fundus, the front lens (14) is placed on the optical axes O-400L, O-400R, and O-500 in front of the eye of the eye to be inspected by moving means (not shown). Inserted. In this case, the front focal position (U0) of the objective lens (401) is conjugate with the retina of the fundus.
When observing the anterior segment of the cornea, iris, etc., observation is performed with the front lens detached from the front of the subject's eye.

  As shown in FIG. 1, the OCT optical system (500) includes an OCT unit (10), an optical fiber (501), a collimating lens (502), an illumination field stop (503), a scanner (504a, 504b), and relay optics. A system (505), a first lens group (506), a second lens group (507), and a reflection mirror (508) are included.

  The OCT unit (10) divides light from an OCT light source having low coherence (short coherence distance) into measurement light and reference light. The measurement light is guided by the OCT optical system (500) and applied to the eye to be examined (8), and is reflected / scattered in the tissue of the eye to be examined, which is returned to the OCT unit (10). The OCT unit (10) detects interference between the return light of the measurement light and the reference light. Thereby, a tomographic image of the tissue of the eye to be examined can be obtained.

  As shown in FIG. 1, the OCT unit (10) is provided outside the ophthalmic microscope main body (6), but one end of the optical fiber (501) is connected, whereby the ophthalmic microscope main body is connected. Linked with (6). The measurement light generated by the OCT unit (10) is emitted from the other end of the optical fiber (501). The emitted measurement light is collimated lens (502), illumination field stop (503), scanner (504a, 504b), relay optical system (505), first lens group (506), second lens group (507), reflection. The return light of the measurement light irradiated to the eye to be examined (8) via the mirror (508) and reflected / scattered by the tissue of the eye to be examined (8) travels in the reverse direction in the same path, and the optical fiber (501). Is incident on the other end.

As shown in FIG. 1, the collimating lens (502) converts the measurement light emitted from the other end of the optical fiber (501) into a parallel light flux. The collimating lens (502) and the other end of the optical fiber (501) are configured to be relatively movable along the optical axis of the measurement light. In the first embodiment, the collimator lens (502) is configured to be movable, but the other end of the optical fiber (501) may be configured to be movable along the optical axis of the measurement light.
The illumination field stop (503) is conjugate with the front focal position (U0) of the objective lens (401).

Scanners (504a, 504b) in the OCT optical system two-dimensionally change the direction of the measurement light that has been converted into a parallel light beam by the collimator lens (502). In the scanner (504a, 504b), a reflecting member configured to be rotatable about two axes intersecting each other is used. Examples of the reflecting member include a galvanometer mirror, a polygon mirror, a rotating mirror, and a MEMS (Micro Electro Mechanical Systems) mirror. In the first embodiment, the scanner (504a, 504b) includes a galvanometer mirror. In other words, the scanner includes a first scanner (504a) having a reflective surface that can be rotated about a first axis, and a second scanner having a reflective surface that can be rotated about a second axis orthogonal to the first axis. (504b). A relay optical system (505) is provided between the first scanner (504a) and the second scanner (504b).
The first lens group (506) includes one or more lenses, and the second lens group (507) also includes one or more lenses.
The objective lens of the OCT optical system may be in an optically conjugate relationship with a member such as a galvanometer mirror. In that case, the objective lens of the OCT optical system can be made small.
Visible light for observation can also be added to the scanner in the OCT optical system.

FIG. 3 is a drawing schematically showing an optical configuration of the OCT unit (10) used in the ophthalmic microscope according to the first embodiment.
As shown in FIG. 3, the OCT unit (10) divides the light emitted from the OCT light source unit (1001) into measurement light (LS) and reference light (LR), and passes through another optical path (measurement light ( LS) and reference light (LR) constitute an interferometer that detects interference.
The OCT light source unit (1001) includes a wavelength scanning type (wavelength sweep type) light source capable of scanning (sweeping) the wavelength of emitted light, as in a general swept source type OCT apparatus. The OCT light source unit (1001) temporally changes the output wavelength at a near infrared wavelength that cannot be visually recognized by human eyes. The light output from the OCT light source unit (1001) is indicated by a symbol L0.

The light L0 output from the OCT light source unit (1001) is guided to the polarization controller (1003) by the optical fiber (1002) and its polarization state is adjusted. The polarization controller (1003) adjusts the polarization state of the light L0 guided in the optical fiber (1002), for example, by applying external stress to the looped optical fiber (1002).
The light L0 whose polarization state is adjusted by the polarization controller (1003) is guided to the fiber coupler (1005) by the optical fiber (1004), and is divided into measurement light (LS) and reference light (LR).

As shown in FIG. 3, the reference light (LR) is guided to the collimator (1007) by the optical fiber (1006) to become a parallel light beam. The reference light LR that has become a parallel light beam is guided to the corner cube (1010) via the optical path length correction member (1008) and the dispersion compensation member (1009). The optical path length correction member (1008) acts as a delay unit for matching the optical path lengths (optical distances) of the reference light (LR) and the measurement light (LS). The dispersion compensation member (1009) acts as a dispersion compensation means for matching the dispersion characteristics of the reference light (LR) and the measurement light (LS).
The corner cube (1010) folds the traveling direction of the reference light (LR) that has become a parallel light beam by the collimator (1007) in the reverse direction. The optical path of the reference light (LR) incident on the corner cube (1010) and the optical path of the reference light (LR) emitted from the corner cube (1010) are parallel. The corner cube (1010) is movable in a direction along the incident optical path and the outgoing optical path of the reference light (LR). By this movement, the length of the optical path (reference optical path) of the reference light (LR) is changed.

As shown in FIG. 3, the reference light (LR) passing through the corner cube (1010) is converged from the parallel light flux by the collimator (1011) via the dispersion compensation member (1009) and the optical path length correction member (1008). It is converted into a light beam, enters the optical fiber (1012), is guided to the polarization controller (1013), and the polarization state of the reference light (LR) is adjusted.
The polarization controller (1013) has the same configuration as the polarization controller (1003), for example. The reference light LR whose polarization state is adjusted by the polarization controller (1013) is guided to the attenuator (1015) by the optical fiber (1014), and the light quantity is adjusted under the control of the arithmetic control unit (12). The reference light (LR) whose light quantity is adjusted by the attenuator (1015) is guided to the fiber coupler (1017) by the optical fiber (1016).

  As shown in FIG. 3, the measurement light (LS) generated by the fiber coupler (1005) is guided to the optical fiber (501). The measurement light emitted from the optical fiber (501) is shown in FIG. To the collimating lens (502). As shown in FIG. 1, the measurement light incident on the collimating lens (502) includes an illumination field stop (503), a scanner (504a, 504b), a relay optical system (505), and a first lens group (506). The eye (8) is irradiated through the second lens group (507) and the reflection mirror (508). The measurement light is reflected and scattered at various depth positions of the eye to be examined (8). The backscattered light of the measurement light by the eye to be inspected (8) travels in the same direction as the forward path in the reverse direction, and is guided to the fiber coupler (1005) and passes through the optical fiber (1018) as shown in FIG. Then, the fiber coupler (1017) is reached.

  The fiber coupler (1017) combines (interferes) the measurement light (LS) incident through the optical fiber (1018) and the reference light (LR) incident through the optical fiber (1016). ) Generate interference light. The fiber coupler (1017) generates a pair of interference light (LC) by branching the interference light between the measurement light (LS) and the reference light (LR) at a predetermined branching ratio (for example, 50:50). . A pair of interference light (LC) emitted from the fiber coupler (1017) is guided to the detector (1021) by two optical fibers (1019, 1020), respectively.

  The detector (1021) has, for example, a pair of photodetectors that respectively detect a pair of interference lights (LC), and outputs a difference between detection results, thereby providing a balanced photodiode (hereinafter referred to as “BPD”). ). The detector (1021) sends the detection result (detection signal) to the arithmetic control unit (12). The arithmetic control unit (12), for example, forms a cross-sectional image by performing Fourier transform or the like on the spectrum distribution based on the detection result obtained by the detector (1021) for each series of wavelength scans (for each A line). To do. The arithmetic control unit (12) displays the formed image on the display unit (13).

  In this embodiment, a Michelson interferometer is used. However, for example, any type of interferometer such as a Mach-Zehnder type can be appropriately used.

FIG. 4 is a cross-sectional view schematically showing the arrangement of optical paths around the objective lens in the ophthalmic microscope according to the first embodiment.
As shown in FIG. 4, the optical path (P-400L) of the observation optical system for the left eye, the optical path (P-400R) of the observation optical system for the right eye, and illumination in the barrel of the ophthalmic microscope body (6) An optical path (P-300) of the optical system and an optical path (P-500) of the OCT optical system are arranged.
Since the ophthalmic microscope of the present invention does not use a large-diameter objective lens, the optical paths of the respective optical systems can be made independent and controlled independently.

FIG. 5 is a front view schematically showing the optical configuration of the objective lens in the ophthalmic microscope according to the first embodiment.
FIG. 5A shows the configuration of the objective lens used in the ophthalmic microscope of the first embodiment, and FIG. 5B shows the direction of the optical axis of each lens constituting the objective lens.

As shown in FIG. 5 (A), the objective lens (401) used in the ophthalmic microscope of the first embodiment is the first lens (401a) and an optical element (401b) that changes the direction of the optical axis. ) And the second lens (401c). The first lens (401a) is a concave lens having negative power, the optical element (401b) for changing the direction of the optical axis is a wedge prism, and the second lens (401c) is a positive lens. It is a convex lens having power.
As shown in FIG. 5B, the optical axis (Q-401a) of the first lens is inclined inward (a direction intersecting with each other on the eye side to be examined).

1-3. Second and Third Embodiments Next, examples of other embodiments of the present invention will be described with reference to the drawings.
FIG. 6 schematically shows the arrangement of optical paths around the objective lens in the ophthalmic microscope of the second embodiment and the ophthalmic microscope of the third embodiment, which are other examples of the ophthalmic microscope of the present invention. It is sectional drawing.
6A shows the arrangement of the optical path around the objective lens of the ophthalmic microscope according to the second embodiment, and FIG. 6B shows the optical path around the objective lens of the ophthalmic microscope according to the third embodiment. The arrangement of

As shown in FIG. 6 (A), in the ophthalmic microscope of the second embodiment, the optical path (P-400L) of the left-eye observation optical system is placed in the lens barrel of the ophthalmic microscope main body (6). In addition to the optical path (P-400R) of the observation optical system for the right eye, the optical path (P-300) of the illumination optical system, and the optical path (P-500) of the OCT optical system, the optical path for the left eye of the sub-observation optical system (P-400SL) and the optical path for the right eye (P-400SR) are arranged.
The sub-observation optical system is used by an observer who is an assistant other than the main observer (operator) to observe the eye to be examined.
Since the ophthalmic microscope of the present invention does not use a large-diameter objective lens, it is possible to arrange the optical paths of many optical systems independently as described above.

  As shown in FIG. 6B, in the ophthalmic microscope of the third embodiment, the optical path (P-400L) of the left-eye observation optical system is located near the center of the barrel of the ophthalmic microscope main body (6). The optical path (P-400R) of the right-eye observation optical system and the optical path (P-300) of the illumination optical system are arranged so as to be concentrated. This makes it possible to reduce the angle formed by the optical paths without overlapping the optical paths of the observation optical system and the OCT optical system, thereby expanding the range in which the shape observation by the microscope and the tomographic observation by the OCT can be performed simultaneously. be able to.

1-4. Configuration of Objective Lens The objective lens used in the ophthalmic microscope of the present invention is an objective consisting of a lens group including at least a first lens, an optical element that changes the direction of the optical axis, and a second lens. It is a lens.
Here, the first lens, the optical element that changes the direction of the optical axis, and the second lens may be arranged in any order.
Further, other lenses and optical elements can be added to these lenses to form a lens group used as an objective lens.

  Moreover, any lens can be used for the first lens and the second lens, and the first lens and the second lens can be appropriately designed so that the eye to be examined can be enlarged while being focused. Preferably, one of the first lens and the second lens is a convex lens having a positive power, and the other is a concave lens having a negative power.

  Any optical element that can change the direction of the optical path can be used as the optical element that changes the direction of the optical axis, and is not limited to these. A prism that changes the optical path can be used. As such a prism, for example, a wedge prism or a rhomboid prism capable of changing the position of the optical axis to the orientation can be used.

  When the first lens, the optical element that changes the direction of the optical axis, and the second lens are arranged in this order from the eye side, the optical element that changes the direction of the optical axis The direction of the optical axis of the observation optical system is changed so as to intersect on the eye side. For this reason, the optical axis of the first lens of the observation optical system for the left eye and the optical axis of the first lens of the observation optical system for the right eye are tilted in a direction that intersects with the eye to be examined. It is preferable. Here, the “lens optical axis” is different from the “optical axis of the optical system” and means the optical axis of a single lens.

When the first lens, the optical element that changes the direction of the optical axis, and the second lens are arranged in this order from the eye side, the second lens of the left-eye observation optical system is arranged. It is preferable that the optical axis of the lens and the optical axis of the second lens of the right-eye observation optical system are inclined in a direction away from each other on the eye side.
With such a configuration, it is possible to greatly improve the problem that the peripheral focus difference is reversed between the left and right eye images as shown in FIG.

1-5. Fourth Embodiment FIG. 7 is a front view schematically showing an optical configuration of an objective lens in an ophthalmic microscope according to a fourth embodiment which is another example of the ophthalmic microscope of the present invention.
FIG. 7A shows the configuration of the objective lens used in the ophthalmic microscope of the fourth embodiment, and FIG. 7B shows the direction of the optical axis of each lens constituting the objective lens.

  As shown in FIG. 7A, the objective lens (401) used in the ophthalmic microscope according to the fourth embodiment includes a first lens (401a) and an optical element (401b) that changes the direction of the optical axis. ) And the second lens (401c). The first lens (401a) is a concave lens having negative power, the optical element (401b) for changing the direction of the optical axis is a wedge prism, and the second lens (401c) is a positive lens. It is a convex lens having power.

As shown in FIG. 7B, the optical axes (Q-401c) of the second lens are inclined in directions away from each other on the eye side.
With such a configuration, it is possible to greatly improve the problem that the peripheral focus difference is reversed between the left and right eye images as shown in FIG.

1-6. Fifth Embodiment FIG. 8 is a front view schematically showing an optical configuration of an objective lens in an ophthalmic microscope according to a fifth embodiment which is another example of the ophthalmic microscope of the present invention.
FIG. 8A shows the configuration of the objective lens used in the ophthalmic microscope of the fifth embodiment, and FIG. 8B shows the direction of the optical axis of each lens constituting the objective lens.

  As shown in FIGS. 8A and 8B, the objective lens (401) used in the ophthalmic microscope according to the fifth embodiment has a wedge prism (401b) and negative power from the eye side. A concave lens (401a) having a positive power and a convex lens (401c) having a positive power are arranged in this order.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to above-described embodiment, The change of the conditions etc. which do not deviate from a summary are all the application scopes of this invention.

  The ophthalmic microscope of the present invention is an ophthalmic microscope that enables correction of residual aberrations, has aberrations that are close to left and right, and a focus difference, and is suitable for binocular vision, and has a small aperture objective lens Since another optical system such as an OCT apparatus can be easily installed, it can be used in the optical equipment industry and the medical equipment related industry.

DESCRIPTION OF SYMBOLS 1 Ophthalmic microscope 2 Subject 300 Illumination optical system 301 Optical fiber 302 Emission light stop 303 Condenser lens 304 Illumination field stop 305 Collimate lens 306 Reflection mirror 400 Observation optical system 400L Left-eye observation optical system 400R Right-eye observation optical System 401 Objective lens 401a First lens 401b Optical element 401c for changing the direction of the optical axis Second lens 402 Zoom lens 402a, 402b, 402c Zoom lens 403 Beam splitter 404 Imaging lens 405 Image erecting prism 406 Eye width Adjustment prism 407 Field stop 408 Eyepiece 500 OCT optical system 501 Optical fiber 502 Collimate lens 503 Illumination field stop 504a, 504b Scanner 505 Relay optical system 506 First lens group 507 Second lens group 508 Reflective mirror 6 Eye Medical microscope main body 8 Eye to be examined 9 Illumination light source 10 OCT unit 1001 OCT light source unit 1002 Optical fiber 1003 Polarization controller 1004 Optical fiber 1005 Fiber coupler 1006 Optical fiber 1007 Collimator 1008 Optical path length correction member 1009 Dispersion compensation member 1010 Corner cube 1011 Collimator 1012 Optical fiber 1013 Polarization controller 1014 Optical fiber 1015 Attenuator 1016 Optical fiber 1017 Fiber coupler 1018 Optical fiber 1019 Optical fiber 1020 Optical fiber 1021 Detector 1101 Imaging lens 1102 Reflecting mirror 1103 Television camera 1103a Image sensor 12 Arithmetic control unit 13 Display unit 14 Pre-lens A-401 Objective lens optical axis A-402 Variable magnification lens optical axis A-40 a Optical axis A-401c of the first lens O-300 of the second lens Optical axis O-400 of the illumination optical system Optical axis O-400L of the observation optical system Optical axis O- of the observation optical system for the left eye 400R Optical axis of the observation optical system for the right eye O-500 Optical axis of the OCT optical system P-300 Optical path of the illumination optical system P-400L Optical path of the observation optical system for the left eye P-400R Optical path P of the observation optical system for the right eye -400SL Optical path for the left eye of the sub-observation optical system P-400SR Optical path for the right eye of the sub-observation optical system P-500 Optical path of the OCT optical system Q400L Focus position Q400R of the left-eye observation optical system Observation optical system for the right eye Focus position V400L Image for left eye V400R Image for right eye L0 Light output from OCT light source unit Interference light LS Measurement light LR Reference light U0 Front focal position

Claims (7)

An ophthalmic microscope comprising: an illumination optical system that illuminates the eye to be examined; and an observation optical system having a left-eye observation optical system and a right-eye observation optical system for observing the subject eye illuminated by the illumination optical system In
In the ophthalmic microscope, the optical axis of the left-eye observation optical system and the optical axis of the right-eye observation optical system are substantially parallel,
The left-eye observation optical system and the right-eye observation optical system each have an objective lens,
The objective lens comprises a lens group having at least a first lens, an optical element that changes the direction of the optical axis, and a second lens;
The objective lens changes the direction of the optical axis of the left-eye observation optical system and the direction of the optical axis of the right-eye observation optical system in a direction intersecting with each other on the eye side to be examined.
An ophthalmic microscope characterized by that.   The ophthalmic microscope according to claim 1, wherein the optical element that changes the direction of the optical axis is a wedge prism.   The ophthalmic microscope according to claim 1 or 2, wherein the first lens is a concave lens having a negative power, and the second lens is a convex lens having a positive power. In the objective lens, the first lens, the optical element that changes the orientation of the optical axis, and the second lens are arranged in this order from the eye side to be examined.
The optical axis of the first lens of the observation optical system for the left eye and the optical axis of the first lens of the observation optical system for the right eye are inclined in a direction intersecting each other on the eye side to be examined. The ophthalmic microscope according to claim 1, wherein the ophthalmic microscope is provided. In the objective lens, the first lens, the optical element that changes the orientation of the optical axis, and the second lens are arranged in this order from the eye side to be examined.
The optical axis of the second lens of the observation optical system for the left eye and the optical axis of the second lens of the observation optical system for the right eye are inclined in directions away from each other on the eye side to be examined. The ophthalmic microscope according to any one of claims 1 to 3, wherein the ophthalmic microscope is characterized.   6. The optical system according to claim 1, wherein an optical system other than the observation optical system is disposed in an intermediate region between the left-eye observation optical system and the right-eye observation optical system. The ophthalmic microscope described. The ophthalmic microscope according to claim 6, wherein an optical system other than the observation optical system is an OCT optical system.