JP7002817B2 - Front lens device and ophthalmic microscope - Google Patents

Description

The present invention relates to an ophthalmic microscope for magnifying and observing an eye to be inspected, and a pre-lens device for inserting and removing a pre-lens between the objective lens of the ophthalmic microscope and the eye to be inspected.
The present invention particularly relates to a front lens device having a mechanism capable of exchanging two or more front lenses, and an ophthalmologic microscope having the front lens device.

An ophthalmic microscope is a medical or examination device capable of magnifying and observing a patient's eye to be inspected by an observation optical system including a lens or the like.
Some ophthalmic microscopes have a function of observing the anterior segment of the eye (eg, cornea, anterior capsule, sclera, etc.) and a function of observing the posterior segment of the eye (eg, retina). In this type of ophthalmic microscope, the anterior lens can be inserted and removed on the optical path of the observation optical system between the objective lens and the eye to be inspected to switch between anterior ocular segment observation and posterior ocular segment observation.

When observing the anterior segment of the eye, as shown in FIG. 12A, the anterior segment of the eye to be inspected 11 is located at the focal position (anterior focal position) U0 on the side of the object to be inspected 11 with respect to the objective lens 13 of the observation optical system. As such, the distance H2 between the objective lens 13 and the eye to be inspected 11 is set. Assuming that the focal length from the objective lens 13 of the observation optical system is F1, H2 = F1.
On the other hand, when observing the posterior eye portion, as shown in FIG. 12B, the distance H2'between the objective lens 13 and the eye to be inspected 11 is set longer, and the distance between the anterior focal position U0 and the eye to be inspected 11 is set longer. The front lens 6 is arranged. The front lens 6 is arranged so as to guide the light of the observation optical system as parallel light to the crystalline lens 11b of the eye to be inspected and to focus on the retina 11a via the crystalline lens 11b. Assuming that the focal length of the front lens 6 is F2, it is typically H2'≈F1 + 2 × F2.

Various types of front lens devices have been developed that support the front lens in a removable manner on the optical path.
For example, a front lens device capable of inserting and detaching a front lens into and out of the optical path of an observation optical system by holding the front lens by a holding arm and turning the holding arm around a swivel axis. It has been developed (Patent Documents 1 [0027] to [0032]). The holding arm can be further provided with a loupe holding mechanism, and the loupe can be inserted into and removed from the optical path of the observation optical system to adjust the focal position in the eye to be inspected (Patent Documents 1 [0071] to [0077]. ).
In addition, a revolver-type front-end lens with two front-end lenses attached to a lens receiving part that rotates about a rotation axis tilted with respect to the optical axis of the observation optical system of an ophthalmic microscope via a bent lens holder. Lens devices are being developed. In this front lens device, two front lenses can be exchanged on the optical path of the observation optical system (Patent Document 2 [0120]).

As described above, in the conventional front lens device, the number of front lenses held is usually one, and at most two, and in order to use front lenses having different refractive powers, the front lens is manually held. It was something that needed to be replaced.

Japanese Unexamined Patent Publication No. 2003-062003 Japanese Unexamined Patent Publication No. 2009-205156

Ophthalmic microscopes generally use at least two types of front lenses when used in surgery. Conventionally, since it is complicated to replace the two types of front lenses manually by an assistant or the like, it has been desired to develop a front lens device that can easily replace the front lenses.
However, when using an ophthalmic microscope for surgery, not only the surgeon but also the assistant and others jointly perform the surgery on the patient's eye to be inspected, so the surgeon and the assistant who work near the eye to be inspected come into contact with each other. There is a problem that two types of front lenses must be arranged so that they do not go into the observation field of the ophthalmologic microscope.
In particular, in a method of rotating the lens receiving portion around a rotation axis that is considerably inclined with respect to the optical axis of the observation optical system, such as the revolver type front lens device described in Patent Document 2, three or more. When the front lens of the above was attached, there was a risk that the unused front lens would also be within the observation field of the ophthalmologic microscope.
Further, in the revolver type front lens device described in Patent Document 2, it is necessary to manually replace all the front lenses, and it is easy to accurately align the front lens on the optical axis of the observation optical system. In particular, when it was desired to alternately see the anterior segment of the eye (eg, cornea, anterior capsule, strong membrane, etc.) and the posterior eye (eg, retina), time loss during surgery occurred.

Therefore, in view of the above-mentioned conventional situation, in the present invention, at least two types of front lenses can be exchanged, and the hands of a surgeon, an assistant, etc. do not come into contact with each other, and they do not enter the field of view of an ophthalmologic microscope. The purpose of the present invention is to develop a front lens device that makes it easy to accurately place the front lens on the optical axis of the observation optical system.

In order to solve the above-mentioned problems, the inventors of the present application have studied diligently, and as a result, the front lens support to which at least two front lenses are attached is substantially parallel to the optical axis of the observation optical system of the ophthalmologic microscope. By rotating the front lens around the axis of rotation by the drive unit, it is possible to prevent the front lens from coming into contact with the hands of a surgeon, assistant, etc., or entering the field of view of an ophthalmic microscope, and further, observation optics. We have found that it is easy to accurately arrange the front lens on the optical axis of the system, and have completed the present invention.

That is, the present invention provides the following first invention relating to a front lens device and the following second invention relating to an ophthalmic microscope.
(1) The first invention is a front lens device used for an ophthalmic microscope having an observation optical system for observing an eye to be inspected.
A front lens support that rotates around a rotation axis that is substantially parallel to the optical axis of the observation optical system, a drive unit that rotates the front lens support, and at least two attached to the front lens support. With a front lens,
The present invention relates to a front lens device, wherein the front lens inserted in the optical path of the observation optical system can be replaced by rotating the front lens support.
(2) In the front lens device of the first invention, it is preferable that three or four front lenses are mounted on the front lens support so as to be rotationally symmetric.
(3) In any of the front lens devices, it is preferable that the front lens is attached to the lens support so that the distance from the objective lens of the ophthalmologic microscope is different.
(4) In the case of (3), it is preferable that the front lens having a shorter focal length is attached to the side to be inspected.
(5) In the case of (4), the positions of at least two of the front lenses in the optical axis direction of the observation optical system are shifted by the difference in the length of the focal length of the front lenses. It is preferable to arrange the front lens.
(6) The second invention relates to an ophthalmic microscope comprising an observation optical system for observing an eye to be inspected, comprising any one of the above-mentioned pre-lens devices.
(7) In the ophthalmic microscope of the second invention, it is removable on the optical axis of the observation optical system and is used to adjust the focal position on the side of the eye to be inspected with respect to the objective lens of the observation optical system. It is preferable to have an objective auxiliary lens.
(8) In the ophthalmic microscope of the above (7), it is preferable that the objective auxiliary lens is a lens having a negative power.
(9) The ophthalmic microscope according to (7) or (8) preferably has a switching mechanism for inserting or removing the objective auxiliary lens in conjunction with the insertion or removal of the front lens.
(10) In any of the ophthalmic microscopes (7) to (9), when the number of the front lenses is n (n ≧ 2), at least n objective auxiliary lenses are provided. Is preferable.

According to the front lens device of the first invention and the ophthalmic microscope of the second invention, the front lens support rotates about a rotation axis substantially parallel to the optical axis of the observation optical system, so that the observation optical system The front lens separated from the optical path of the observation optical path can be separated from the optical path of the observation optical system with a sufficient distance. This effectively prevents the front lens from coming into contact with the working hand of the surgeon, assistant, etc., or entering the observation field of the ophthalmologic microscope, and at the same time, two or more front lenses. The lens can be arranged interchangeably. Further, since the front lens support is rotated by the driving unit instead of manually, it becomes easy to accurately arrange the front lens on the optical axis of the observation optical system.

It is a perspective view schematically showing the front lens apparatus and the ophthalmologic microscope of the 1st Embodiment of this invention. It is a top view which shows typically the front lens support used in 1st Embodiment. FIG. 2A shows a plan view of the same front lens support as the front lens support shown in FIG. 1, and FIG. 2B shows a front lens support that holds two front lenses. The plan view of the body is shown, (C) shows the plan view of the front lens support which holds four front lenses, and (D) shows the plane of the front lens support which holds six front lenses. The figure is shown. It is a perspective view schematically showing the front lens apparatus and the ophthalmologic microscope of the 2nd Embodiment of this invention. It is a schematic diagram showing the relationship between the distance between the objective lens and the eye to be inspected when the anterior eye portion observation and the posterior eye portion observation are switched by inserting and removing the anterior lens. FIG. 4A shows the positional relationship when observing the anterior eye portion, FIG. 4B shows the positional relationship when observing the posterior eye portion, and FIG. 4C shows the objective auxiliary lens. Shows the positional relationship when observing the anterior segment of the eye using. It is a schematic diagram which shows the relationship of the distance between an objective lens and an eye under test when the refractive power of a front lens is different. FIG. 5 (A) shows the positional relationship when a front lens having a refractive power of D is used, and FIG. 5 (B) shows the positional relationship when using a front lens having a refractive power of D ″. FIG. 5C shows the positional relationship between the front lens having a refractive power of D ″ and the objective auxiliary lens. It is a side view which shows typically the structure of the optical system at the time of observing the anterior eye portion in the ophthalmic microscope of the 3rd Embodiment of this invention. It is a front view schematically showing the structure of the optical system when observing the anterior segment of the eye in the ophthalmic microscope of the third embodiment of the present invention. It is a perspective view which shows typically the arrangement of the objective auxiliary lens when observing the anterior eye portion. FIG. 8A shows the arrangement of the objective auxiliary lens in the ophthalmologic microscope according to the third embodiment of the present invention, and FIG. 8B shows the objective auxiliary lens on the side opposite to the eye side of the objective lens. The arrangement when it is provided is shown. It is a side view which shows typically the structure of the optical system at the time of observing the posterior eye part in the ophthalmic microscope of the 3rd Embodiment of this invention. It is a front view which shows typically the structure of the optical system at the time of observing the posterior eye part in the ophthalmic microscope of the 3rd Embodiment of this invention. It is a perspective view which shows typically the arrangement of the objective auxiliary lens at the time of observing the posterior eye part. FIG. 11 (A) shows the arrangement of the objective auxiliary lens in the ophthalmologic microscope according to the third embodiment of the present invention, and FIG. 11 (B) shows the objective auxiliary lens on the side opposite to the eye surface side of the objective lens. The arrangement when it is provided is shown. It is a schematic diagram showing the relationship between the distance between the objective lens and the eye to be inspected when the anterior eye portion observation and the posterior eye portion observation are switched by inserting and removing the anterior lens.

1. 1. Front lens device The front lens device of the present invention relates to a front lens device used in an ophthalmic microscope having an observation optical system for observing an eye to be inspected.
It has a front lens support that rotates about a rotation axis substantially parallel to the optical axis of the observation optical system, and at least two front lenses attached to the front lens support.
By rotating the front lens support, the front lens inserted in the optical path of the observation optical system can be replaced.

In the front lens device of the present invention, the front lens support rotates about a rotation axis substantially parallel to the optical axis of the observation optical system. Therefore, the front lens separated from the optical path of the observation optical system can be separated from the optical path of the observation optical system with a sufficient distance. This makes it possible to effectively prevent the front lens from coming into contact with a working hand such as a surgeon and an assistant, or from entering the observation field of an ophthalmologic microscope.
Then, in the front lens device of the present invention, two or more front lenses can be interchangeably arranged by attaching at least two front lenses to the front lens support.
Further, in the front lens device of the present invention, since the front lens support is rotated by the drive unit instead of manually, it becomes easy to accurately arrange the front lens on the optical axis of the observation optical system. ..

On the other hand, there are three methods in which the front lens is rotated around a rotation axis that is considerably inclined with respect to the optical axis of the observation optical system, as in the conventional front lens device described in Patent Document 2. When the above front lenses are attached, at least two unused front lenses cannot be separated from the optical path of the observation optical system with a sufficient distance, so that they are within the observation field of the ophthalmologic microscope. There was a risk of getting in. In addition, if the connecting member between the axis of rotation and the front lens is lengthened so that the unused front lens does not enter the observation field of view, the front lens device occupies a large space around the eye to be inspected. As a result, there is a high risk that the hands of the surgeon and his assistant, who are working near the eye to be inspected, will come into contact with the front lens. Further, in the revolver type front lens device described in Patent Document 2, it is necessary to manually replace all the front lenses, and it is easy to accurately align the front lens on the optical axis of the observation optical system. There wasn't.

In the present invention, the rotation axis of the front lens support is "substantially parallel to the optical axis of the observation optical system" when it is completely parallel to the optical axis of the observation optical system or the tilt angle is in the range of 15 °. It means that they are almost parallel within. Preferably, the rotation axis of the front lens support is completely parallel to the rotation axis of the observation optical system, or is substantially parallel to the tilt angle within a range of 5 °.
In the present invention, the "rotational shaft" may include a shaft-shaped member that serves as a rotation shaft, but even if there is actually no shaft-shaped member, there is an ideological shaft that is the center of rotation. do it.
Hereinafter, one example of the embodiment of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
1 and 2 are drawings schematically showing a first embodiment of the present invention.
FIG. 1 shows a perspective view of a front lens device and an ophthalmic microscope according to the first embodiment of the present invention.
FIG. 2 shows a plan view of a front lens support used in the front lens device according to the first embodiment of the present invention.
As shown in FIG. 1, the front lens device 1 is attached to the rotation arm 4, the front lens support 5 that rotates about the rotation arm 4, and the front lens support 5 so as to be rotationally symmetric. It has three front lenses 601, 602, 603.
In the first embodiment, the rotation arm 4 coincides with the rotation axis of the front lens support 5.
The front lens 601 is a convex lens having a refractive power of 40D (diopter), the front lens 602 is a convex lens having a refractive power of 80D, and the front lens 603 is a convex lens having a refractive power of 120D.

The rotary arm 4 can be rotated by the drive motor 1001, and the front lens inserted in the optical path of the observation optical system can be replaced. FIG. 1 shows a state in which the front lens 601 is inserted in the optical path of the observation optical system. In FIG. 1, the optical axis O-300 of the observation optical system passing through the center of the optical path of the observation optical system is shown by a dotted line. The optical path of the observation optical system passes through the front lens and is incident on the eye to be inspected 11.
The front lens support 5 rotates about a rotating arm 4 substantially parallel to the optical axis O-300 of the observation optical system. That is, the rotation axis of the front lens support 5 is substantially parallel to the optical axis O-300 of the observation optical system. Therefore, as shown in FIG. 1, since the unused front lenses 602 and 603 are sufficiently separated from the optical axis O-300 of the observation optical system, there is no possibility that they will enter the observation field of view of the ophthalmologic microscope. Further, since the front lens support 5 can have a compact shape, there is little risk of contact with the hands of a surgeon, an assistant, or the like working near the eye to be inspected.
Further, since the front lens support 5 is rotated by the drive motor 1001, it is easy to accurately arrange the front lenses 601, 602, 603 on the optical axis O-300 of the observation optical system.
Further, since the rotation axis of the front lens support 5 is substantially parallel to the optical axis O-300 of the observation optical system, as shown in FIG. 1, the rotation arm 4 serving as the rotation axis is lengthened. The drive motor 1001 serving as a drive unit for rotating the rotation axis can be arranged near the lens barrel 14 away from the work space.

As shown in FIG. 1, the rotary arm 4 is rotatably held by the support arm 1002. The support arm 1002 is rotatably connected to the support bracket 1004 about the swivel shaft 1003. Therefore, the support arm 1002 can be swiveled by manually operating the swivel lever 1005. By this turning operation, the front lens support 5 can be retracted from the optical path of the observation optical system. Further, the retracted front lens support 5 can be reinserted into the optical path of the observation optical system by operating the swivel lever 1005.
The support bracket 1004 is connected to the front lens position adjusting device 1007 via the connecting arm 1006. The front lens position adjusting device 1007 controls the vertical position of the front lens by driving the connecting arm 1006 up and down in the optical axis direction of the observation optical system.

As described above, the front lens device 1 includes the rotary arm 4, the front lens support 5, the front lens 601, 602, 603, the drive motor 1001, the support arm 1002, the swivel shaft 1003, the support bracket 1004, and the swivel lever. It comprises 1005, a connecting arm 1006, and a front lens position adjusting device 1007.
The front lens device 1 is attached to the main body 12 of an ophthalmic microscope. The front lens device 1 can also be attached to the ophthalmic microscope main body 12 via an attachment portion (not shown) so that it can be easily attached to and detached from the main body 12.
The ophthalmic microscope 2 includes an ophthalmic microscope main body 12 and a front lens device 1.
The main body 12 of the ophthalmologic microscope has a lens barrel 14 for accommodating an optical element such as a lens of an observation optical system, and an objective lens 13 is installed on the most side of the lens barrel 14 on the eye to be inspected 11.
The front lens position adjusting device 1007 can be used to adjust the distance between the front lens and the objective lens 13 according to the focal length of the front lens inserted in the optical path of the observation optical system. ..

When the front lens is inserted into the optical path of the observation optical system, the image of the eye to be inspected is inverted and becomes an inverted image. Therefore, a lens unit for returning this to a normal image is provided in the inverter unit 15. As the optical system of the lens unit provided in the inverter unit 15, for example, the one disclosed in Japanese Patent Publication No. 7-48091 can be used. The lens unit can be inserted and removed on the optical path in the lens barrel by manually operating the switching lever 16 in conjunction with the insertion and removal of the front lens support 5 by the operation of the swivel lever 1005. Further, the lens unit can be automatically inserted and removed on the optical path in the lens barrel by operating an actuator (not shown) in conjunction with the insertion and removal of the front lens support 5 by the swivel lever 1005.

If the front lens device of the first embodiment is used, for example, when the surgeon observes the inside of the eye to be inspected by the ophthalmologic microscope 2 using the front lens 601 having a refractive power of 40D, the focus is reached. The front lens can be replaced when the image inside the eye to be inspected is blurred. The surgeon drives the drive motor 1001 using a foot switch (not shown) to rotate the rotary arm 4 and the front lens support 5, and inserts the front lens into the optical path of the observation optical system by the refractive power. Can be replaced with an 80D front lens 602. As a result, the surgeon can easily and quickly replace the anterior lens without the help of an assistant or the like, and can improve the workability of the surgery.

Since the front lens support 5 can be attached to and detached from the tip of the rotating arm 4, a plurality of types of front lens supports and a set of front lenses attached to the front lens support are used properly according to the type of surgery or procedure. be able to.

FIG. 2 is a plan view schematically showing the front lens support used in the first embodiment. The front lens supports of FIGS. 2 (A) to 2 (D) are used by being attached to the front lens device according to the type of surgery or procedure, respectively.
FIG. 2A shows a plan view of the same front lens support as the front lens support shown in FIG.
As shown in FIG. 2A, the front lens support 5 holds three front lenses 601, 602, 603 so as to be rotationally symmetric (three-fold symmetric) with respect to the axis of rotation 4. The front lens support 5 and the three front lenses are integrated. The front lens support 5 can be connected to the rotating arm by screwing or the like at the portion of the rotating shaft 4.
By rotating the front lens support 5 around the rotation axis 4, the front lens that transmits the optical path of the observation optical system can be replaced.

FIG. 2B shows a plan view of another front lens support. The front lens support is composed of a front lens support frame 511, 512 and a joint portion 521.
The front lens support frames 511, 512 each have an annular frame body portion for holding the front lens 601, 602 and a rod-shaped shaft body portion. The joint portion 521 has two joints into which the shaft body portion of the front lens support frame can be inserted, and connects the two front lens support frames so as to be rotationally symmetric (twice symmetric). It is possible. Therefore, any two front lenses having different refractive powers can be connected to the joint portion 521 to obtain a front lens support having an arbitrary set of front lenses. In FIG. 2B, the portion indicated by reference numeral 4 is a portion that serves as a rotation axis of the front lens support, and in this portion, it can be connected to the rotation arm by screwing or the like.
By rotating the front lens support around the rotation axis 4, the front lens that transmits the optical path of the observation optical system can be replaced. Further, by rotating the optical path of the observation optical system so as to be located between the two front lenses, it is possible to easily separate the front lens from the optical path of the observation optical system.

FIG. 2C shows a plan view of another front lens support. The front lens support includes a front lens support frame 511, 512, 513, 514 and a joint portion 522.
The front lens support frame 511, 512, 513, 514 has an annular frame body portion for holding the front lens 601, 602, 603, 604, and a rod-shaped shaft body portion, respectively. The joint portion 522 has four joints into which the shaft body portion of the front lens support frame can be inserted, and the four front lens support frames can be connected to each other.
By rotating the front lens support around the rotation axis 4, the front lens that transmits the optical path of the observation optical system can be replaced.
Since the front lens support frame is connected to the joint so that it is rotationally symmetric (four-fold symmetric), work on the left and right of the front lens regardless of which front lens is on the optical path of the observation optical system. Space can be secured.

FIG. 2D shows a plan view of another front lens support. The front lens support 5 has a shape based on a regular hexagon, and has a frame for holding the front lenses 601 to 606 at each side portion of the regular hexagon. As a result, the six front lenses can be arranged so as to be rotationally symmetric (six-fold symmetric) with respect to the rotation axis 4. The front lens support 5 can be connected to the rotating arm by screwing or the like at the portion of the rotating shaft 4.
By rotating the front lens support 5 around the rotation axis 4, the front lens that transmits the optical path of the observation optical system can be replaced.

In the present invention, the "front lens support" has any shape as long as it holds two or more front lenses and the distances from the rotation axis to each front lens are substantially equidistant. You may use the thing. The front lens support is not limited to a two-dimensional shape, but can also have a three-dimensional shape.

The front lens support is preferably shaped to hold each front lens so as to be rotationally symmetric. By arranging the front lenses in rotational symmetry, it is possible to secure the same work space regardless of which front lens is on the optical path of the observation optical system.
In order to arrange the front lens so as to be rotationally symmetric, for example, as in the front lens support shown in FIG. 2D, a regular n-sided lens is used as the base of the shape of the front lens support. By providing a frame for holding the front lens on the side, the front lens can be arranged rotationally symmetrically. In this case, if a frame for holding the front lens is provided on all sides of the regular n-sided polygon, the front lens can be arranged so as to be symmetrical n times with respect to the axis of rotation. Rotational symmetry can also be achieved by providing a frame for holding the front lens on a part of the sides of the regular n-sided polygon. For example, every other of the six sides of the regular hexagon has three sides. By providing a frame for holding the front lens, the three front lenses can be arranged so as to be symmetrical with respect to the rotation axis three times.

The front lens support holds at least two front lenses and usually holds three to six front lenses. In order to make the front lens support compact and secure a large working space, it is preferable that the front lens support holds three or four front lenses so as to be rotationally symmetric.

The front lens support can hold each front lens so that each front lens has a different distance from the objective lens of the ophthalmologic microscope.
Each front lens has a different refractive power and a different focal length. The focal length can be obtained as the inverse of the refractive power (diopter). For example, the refractive power of a front lens having a refractive power of 40D is 1/40 = 0.025 m, and that of a front lens having a refractive power of 80D. The refractive power is 1/80 = 0.0125 m, and the larger the refractive power, the shorter the focal length.
Therefore, it is preferable to arrange the front lens so that the distance from the objective lens when inserted into the optical path of the observation optical system differs depending on the focal length of the front lens.
In particular, for at least two front lenses, it is preferable to arrange the front lenses by shifting the positions of the observation optical system in the optical axis direction by the difference in the length of the focal length of the front lenses.
Hereinafter, an example of an embodiment in which each front lens is arranged so that the distance from the objective lens is different will be described in detail with reference to the drawings.

<Second embodiment>
FIG. 3 is a perspective view schematically showing the front lens device and the ophthalmologic microscope according to the second embodiment of the present invention.
As shown in FIG. 3, the front lens device 1 includes a rotation arm 4, a front lens support 5 that rotates about the rotation arm 4, and a front lens so as to be rotationally symmetric with respect to the rotation axis. It has three front lenses 601, 602, 603 attached to the support 5.
The three front lenses 601, 602, 603 are held by the front lens support 5 so that the distances from the objective lens 13 are different from each other.

The rotary arm 4 can be rotated by the drive motor 1001, and the front lens inserted in the optical path of the observation optical system can be replaced. In the second embodiment, the rotation arm 4 coincides with the rotation axis of the front lens support 5.

The front lens 601 is a convex lens having a refractive power of 40D, the front lens 602 is a convex lens having a refractive power of 80D, and the front lens 603 is a convex lens having a refractive power of 120D.
Among these front lenses, the front lens 601 has the longest focal length because it has the smallest refractive power. Therefore, the front lens 601 is held closest to the objective lens 13 so that the distance from the eye to be inspected 11 is close to the focal length of the front lens 601. On the other hand, the front lens 603 has the shortest focal length because it has the largest refractive power. Therefore, the front lens 603 is held closest to the eye to be inspected 11 so that the distance to the eye to be inspected 11 is close to the focal length of the front lens 603. The front lens 602 is held at a position between the front lens 601 and the front lens 603.
Therefore, even when the front lens support 5 is rotated and the front lens is replaced, the distance between the front lens and the eye to be inspected can be maintained close to the focal length of the front lens. , The position of the front lens can be adjusted only by fine adjustment.
The position of the front lens can be finely adjusted by the front lens position adjustment device 1007.

2. 2. Ophthalmic microscope The ophthalmic microscope of the present invention is an ophthalmic microscope having an observation optical system for observing the eye to be inspected, and in addition to the main body of the ophthalmic microscope, the above 1. It is characterized by having the front lens device described in the above.
In the present invention, the "ophthalmic microscope" refers to a medical or inspection device having an observation optical system including an optical element capable of magnifying and observing the eye to be inspected, and is used not only for humans but also for animals. Including those. The “ophthalmic microscope” includes, but is not limited to, a fundus camera, a slit lamp, a microscope for ophthalmic surgery, and the like.

The ophthalmic microscope preferably further has an illumination optical system, and the return light reflected / scattered from the subject's eye illuminated by the illumination optical system can be magnified and observed by the observation optical system. The illumination optical system includes an optical element for illuminating the eye to be inspected. The illumination optical system may further include a light source, but may be one that guides natural light to the eye to be inspected.
The "observation optical system" in the present invention can be divided into an observation optical system for the left eye and an observation optical system for the right eye, and when parallax is generated in the images obtained by the left and right observation optical systems. Can also be observed three-dimensionally by binocular vision.
The "observation optical system" in the present invention may be one that allows the observer to directly observe the eye to be inspected through an eyepiece or the like, or one that can be observed by receiving light from an image pickup element or the like and forming an image. It may or may have both functions.

An objective lens is provided on the side of the eye to be inspected most of the observation optical system. The front lens device of the present invention is a device capable of interchangeably inserting and removing at least two front lenses between the objective lens and the eye to be inspected.
The main body of the ophthalmic microscope and the front lens device may be integrated, or the front lens device may be easily attached to and detached from the main body of the ophthalmic microscope via an attachment portion.

As described above, the ophthalmologic microscope inserts and removes the anterior lens on the optical path of the observation optical system between the objective lens and the eye to be inspected to observe the anterior segment of the eye (for example, the cornea, anterior capsule, strong membrane, etc.). It is possible to switch between observation of the posterior eye (for example, the retina).
FIG. 4 is a schematic diagram showing the relationship between the distance between the objective lens and the eye to be inspected when the anterior lens is inserted and removed to switch between anterior eye observation and posterior eye observation.
When observing the anterior segment of the eye, as shown in FIG. 4A, the anterior segment of the eye to be inspected 11 is located at the focal position (anterior focal position) U0 on the side of the object to be inspected 11 with respect to the objective lens 13 of the observation optical system. The distance H2 between the objective lens 13 and the eye to be inspected 11 is set so as to be positioned. Assuming that the focal length from the objective lens 13 of the observation optical system is F1, H2 = F1.
On the other hand, when observing the posterior eye portion, as shown in FIG. 4B, the distance H2'between the objective lens 13 and the eye to be inspected 11 is set longer, and the distance between the anterior focal position U0 and the eye to be inspected 11 is set longer. The front lens 6 is arranged. The front lens 6 is arranged so as to guide the light of the observation optical system as parallel light to the crystalline lens 11b of the eye to be inspected and to focus on the retina 11a via the crystalline lens 11b. Assuming that the focal length of the front lens 6 is F2, it is typically H2'≈F1 + 2 × F2.

As is clear from comparing the distance H2 between the objective lens 13 and the eye to be inspected 11 in FIG. 4 (A) and the distance H2'between the objective lens 13 and the eye to be inspected 11 in FIG. 4 (B), the front lens. When inserting 6, it is necessary to increase the distance between the objective lens 13 and the eye to be inspected 11, and each time the front lens is inserted or removed, the ophthalmic microscope body is moved up and down along the optical axis. I need to let you. The vertical movement of the main body of the ophthalmic microscope can be performed manually or automatically, but it is complicated to move the front lens for insertion / removal.
Therefore, when observing the anterior eye portion, as shown in FIG. 4C, the focal length is obtained by separating the front lens from the optical path and inserting the objective auxiliary lens 17 made of a concave lens into the optical path. Is lengthened to match H2'. Then, when observing the posterior eye portion, as shown in FIG. 4B, the objective auxiliary lens 17 is separated from the optical path, and the anterior lens 6 is inserted into the optical path. By using the objective auxiliary lens 17 in this way, the distance between the objective lens 13 and the eye to be inspected 11 becomes H2'whether to observe the anterior eye or the posterior eye, and the main body of the ophthalmic microscope is moved up and down. No need to move to.

Therefore, in the ophthalmic microscope of the present invention, it is preferable to have an objective auxiliary lens used for adjusting the focal position on the side of the eye to be inspected rather than the objective lens of the observation optical system.
Here, the objective auxiliary lens is preferably a lens having a negative power capable of increasing the focal length. A lens with negative power is usually a lens also called a concave lens.
Further, it is preferable that the ophthalmic microscope of the present invention has a switching mechanism capable of automatically inserting or removing the objective auxiliary lens in conjunction with the insertion or removal of the front lens.

FIG. 5 is a schematic diagram showing the relationship between the distance between the objective lens and the eye to be inspected when the refractive powers of the front lenses are different.
FIG. 5A is a diagram showing a state in which the anterior lens 6 is inserted on the optical path when observing the posterior eye portion, and has the same positional relationship as FIG. 4B. In FIG. 5A, the distance between the objective lens 13 and the front lens 6 is indicated by H1'. Further, the refractive power of the front lens 6 is D.
On the other hand, FIG. 5B shows a state in which the front lens 6 is replaced with a front lens 6 ″ having a larger refractive power in the same rear eye observation. The refractive power of the front lens 6 ″ is D ″.

Since the focal lengths of the front lenses 6 and 6 ″ are lengths that can be obtained from the inverse of the refractive power of the lens, FIG. 5 (A) is larger than the focal length F2 of the front lens 6 in FIG. 5 (A). The focal length F2 ″ of the front lens 6 ″ in B) is shorter. As is clear from comparing FIGS. 5 (A) and 5 (B), the distances H1 ′ and H1 ″ between the objective lens 13 and the front lenses 6 and 6 ″ have a short focal length (refraction). It is necessary to make the case of FIG. 5 (B) using the front lens 6 ″ (which has a large force) shorter than that of FIG. 5 (A). Further, the distances H2 ′ and H2 ″ between the objective lens 13 and the eye to be inspected 11 are also in the case of FIG. 5 (B) using the front lens 6 ″ with a short focal length (large refractive power). , It is necessary to make it shorter than the case of FIG. 5 (A).
Therefore, when the front lens is replaced, it is necessary to adjust the distance between the objective lens and the front lens, and at the same time, the main body of the ophthalmologic microscope is moved up and down to be between the objective lens and the eye to be inspected. It is also necessary to adjust the distance of.

Therefore, when the front lens is replaced, as shown in FIG. 5C, the focal length is lengthened by inserting the objective auxiliary lens 17 made of a concave lens into the optical path, and F1 ″ ″ ＝. Make it H2 ″ -2 × F2 ″. Then, the distance between the objective lens 13 and the eye to be inspected 11 coincides with H2'. As a result, even when the front lens is replaced, the distance between the objective lens 13 and the eye to be inspected 11 can remain H2', and it is not necessary to move the microscope body up and down.
However, the distance between the objective lens 13 and the front lens is adjusted to be H1 ′ when the front lens 6 is used, and H1 ″ when the front lens 6 ″ is used. There is a need. Here, as described above, by attaching the front lens to the front lens support so that the distance from each of the objective lenses is different, it is not necessary to adjust the position of the front lens due to the replacement of the front lens. It is possible.

Further, when the front lens is replaced with a third front lens having a larger refractive power, the distance between the objective lens and the eye to be inspected is made constant by using the corresponding third objective auxiliary lens. can do.
Therefore, in the ophthalmic microscope of the present invention, it is preferable to have at least three objective auxiliary lenses for adjusting the focal length when using at least three front lenses in an interchangeable manner. When having n front lenses (n ≧ 3), it is preferable to have n or more objective auxiliary lenses.
Then, in the front lens device, it is preferable to arrange each front lens by shifting the position of the observation optical system in the optical axis direction by the difference in the length of the focal length of the front lens.
Hereinafter, one example of the embodiment of the ophthalmologic microscope of the present invention using the front lens device and the objective auxiliary lens will be described in detail with reference to the drawings.

<Third embodiment>
6 to 11 are drawings schematically showing a third embodiment of the present invention.
FIG. 6 is a side schematic view of the ophthalmic microscope 2, and FIG. 7 is a front schematic view, respectively, showing how to observe the anterior segment of the eye 11 to be inspected (for example, cornea, anterior capsule, sclera, etc.). ing. Further, FIG. 8A shows a schematic diagram of the observation optical system 300 (observation optical system in which the objective auxiliary lens is provided on the side to be inspected of the objective lens) of the ophthalmologic microscopes of FIGS. 6 and 7.
As shown in FIG. 6, the ophthalmic microscope 2 includes an illumination optical system 1800 (not shown in FIG. 7) in addition to the observation optical system 300.
The observation optical system 300 can observe the observation target (the eye to be inspected 11 in FIGS. 6 and 7). As referred to in FIG. 6, the illumination optical system 1800 can illuminate the portion of the eye to be inspected 11 to be observed.
In FIGS. 6 and 7, the observation optical system has an anterior focal position U0 in front of the eye to be inspected 11.

As is shown in FIG. 7, the observation optical system 300 includes an observation optical system 300R for the right eye and an observation optical system 300L for the left eye. Note that FIG. 6 shows the entire configuration of the observation optical system 300R for the right eye, and only the objective lens 13 shared with the observation optical system 300R for the right eye is shown for the observation optical system 300L for the left eye. ..
In FIG. 7, only one front lens 6 is shown, but in reality, at least three front lenses are interchangeably held by the front lens device.
Further, as is clearly shown in FIG. 7, the optical axis O-300R of the observation optical system for the right eye 300R and the optical axis O-300L of the observation optical system 300L for the left eye each pass through the objective lens 13.
In the present embodiment, the illumination optical system 1800 and the observation optical system 300 are housed in the ophthalmic microscope main body 12. In FIGS. 6 and 7, the main body 12 of the ophthalmic microscope is shown by a alternate long and short dash line.

The illumination optical system 1800 shown in FIG. 6 includes an illumination light source 19, an optical fiber 1801, an emission light aperture 1802, a condenser lens 1803, an illumination field aperture 1804, a collimating lens 1805, and a reflection mirror 1806. The optical axis of the illumination optical system 1800 is indicated by O-1800.
As shown in FIG. 6, the illumination light source 19 is provided outside the ophthalmic microscope main body 12 in the present embodiment. One end of the optical fiber 1801 is connected to the illumination light source 19. The other end of the optical fiber 1801 is arranged at a position facing the emitted light diaphragm 1802 of the ophthalmic microscope main body 12. The illumination light emitted from the illumination light source 19 is guided by the optical fiber 1801 and incident on the condenser lens 1803 via the emission light diaphragm 1802.
The emission light diaphragm 1802 acts to block a part of the emission port of the optical fiber 1801. When the cutoff region by the emitted light diaphragm 1802 is changed, the emitted region 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 inspected 11 and the optical axis of the objective lens 13 can be changed.

The illumination field diaphragm 1804 is provided at a position (position of ×) optically conjugate with the front focal position U0 of the objective lens 13. The collimating lens 1805 converts the illumination light that has passed through the illumination field diaphragm 1804 into a parallel light flux. The reflection mirror 1806 reflects the illumination light converted into a parallel light flux by the collimated lens 1805 toward the objective lens 13. The light reflected by the reflection mirror 1806 passes through the objective lens 13 and irradiates the eye 11 to be inspected.
The illumination light applied to the eye 11 to be inspected is reflected and scattered by the tissue of the retina. The reflected / scattered return light (also referred to as “observation light”) passes through the objective lens 13 and is incident on the observation optical system 300.

The observation optical system 300 is used for observing the eye 11 illuminated by the illumination optical system 1800 via the objective lens 13.
As shown in FIGS. 6 and 7, the variable magnification lens system 301 (lenses 301a, 301b, 301c), the beam splitter 302 (beam splitter for acquiring image information for displaying a TV camera), the imaging lens 303, It includes an image erecting prism 304, an eye width adjusting prism 305, a field aperture 306, and an eyepiece lens 307. The optical axis of the observation optical system 300 is indicated by O-300.

As shown in FIG. 7, the beam splitter 302 of the observation optical system for the right eye 300R separates a part of the observation light guided along the observation optical system for the right eye from the eye 11 to be photographed. Lead to 2000. The photographing optical system 2000 includes an imaging lens 2001, a reflection mirror 2002, and a television camera 2003. The image information acquired by the TV camera 2003 is sent to a monitor (not shown) and displayed.

As shown in FIGS. 6 and 7, the image erecting prism 304 converts an inverted image into an erect image. The eye width adjusting prism 305 is an optical element for adjusting the distance between the left and right observation optical paths according to the eye width (distance between the left eye and the right eye) of the observer. The visual field diaphragm 306 limits the observer's visual field by blocking the peripheral region in the cross section of the observation light. The field diaphragm 306 is provided at a position (position ×) conjugate with the front focal position U0 of the objective lens 13.
The observation optical system 300R for the right eye and the observation optical system 300L for the left eye may be configured to include a stereo variator configured to be removable from the optical path. The stereo variator is an optical axis position changing element for changing the relative positions of the optical axes O-300L and O-300R of the left and right observation optical systems guided by the left and right variable magnification lens systems 301, respectively. The stereo variator is retracted to, for example, a retracted position provided on the observer side with respect to the observation optical path.

In the ophthalmic microscope 2 of FIGS. 6 and 7, the observation optical system has an anterior focal position (indicated by U0) in front of the inspected eye 11 when the lens is not present between the objective lens 13 and the inspected eye 11. )have. In the ophthalmic microscope 2, the objective auxiliary lens 17 is provided on the side of the objective lens 13 to be inspected.
The objective auxiliary lens 17 is set at a position closer to the objective lens 13 between the front focal position U0 and the objective lens 13, or can be released from that position. The objective auxiliary lens 17 is selected so that the focal point when set is the first focal point (U1), which is the position of the anterior segment of the eye to be inspected.
Note that FIG. 8A shows a case where the objective auxiliary lens 17 is provided on the side of the objective lens 13 on the side of the eye to be inspected 11 in the observation optical system when observing the anterior eye portion of the eye to be inspected 11. In the present invention, as shown in FIG. 8B, the objective auxiliary lens 17 can be provided on the side of the objective lens 13 opposite to the side of the objective lens 13 to be inspected, and the anterior eye portion of the inspected eye 11 can be observed.

FIG. 9 is a side view corresponding to FIG. 6 showing a state of observing the posterior eye portion (for example, the retina) of the eye to be inspected 11 in the apparatus described with reference to FIGS. 6 and 7. Further, FIG. 10 is a front view corresponding to FIG. 7, and FIG. 11A is a schematic view corresponding to FIG. 8A.
In FIGS. 9 and 10, the anterior lens 6 is set at a position closer to the eye to be inspected 11 than the anterior focal position U0, and the focal point (second focal point) of the eye to be inspected 11 when set is via the crystalline lens. U2) is set at the position of the retina (position of the posterior eye portion) of the eye 11 to be inspected. Further, the objective auxiliary lens 17 is released from the optical path of the observation optical system.
Even when the objective auxiliary lens 17 is provided on the side opposite to the eye 11 side of the objective lens 13 (see FIG. 8B), when observing the rear eye portion of the eye 11 to be inspected, FIG. 11 (B). ), It is necessary to release the objective auxiliary lens 17.

1: Front lens device 2: Ophthalmic microscope 300: Observation optical system 300R: Right eye observation optical system 300L: Left eye observation optical system 301: Variable magnification lens system 302: Beam splitter 303: Imaging lens system 304: Image upright prism 305: Eye width adjustment prism 306: Field aperture 307: Eyepiece lens 4: Rotation arm, rotation axis 5: Front lens support 511 to 514: Front lens support frame 521, 522: Joint portion 601 to 606 : Front lens 1001: Drive motor 1002: Support arm 1003: Swing shaft 1004: Support bracket 1005: Swing lever 1006: Connecting arm 1007: Front lens position adjustment mechanism 11: Front lens position adjustment mechanism 11: Eye to be inspected 11a: Retina 11b: Crystal body 12: For ophthalmology Microscope body 13: Objective lens 14: Lens tube 15: Inverter unit 16: Switching lever 17, 17 ″ ″: Objective auxiliary lens 1800: Illumination optical system 1801: Optical fiber 1802: Emission light aperture 1803: Condenser lens 1804: Illumination field Aperture 1805: Collimating lens 1806: Reflection mirror 19: Illumination light source 2000: Imaging optical system 2001: Imaging lens 2002: Reflection mirror 2003: TV cameras F1, F1', F1'": Focus distance from objective lens F2, F2 ‘ : Optical axis of observation optical system O-300R: Optical axis of observation optical system for right eye O-300L: Optical axis of observation optical system for left eye O-1800: Optical axis of illumination optical system U0: Front focal position U1: First focus U2: Second focus

Claims (10)

In a front lens device used for an ophthalmic microscope having an observation optical system for observing an eye to be inspected.
A front lens support that rotates around a rotation axis that is substantially parallel to the optical axis of the observation optical system, a drive unit that rotates the front lens support, and at least two attached to the front lens support. With a front lens,
The front lens is inserted and removed between the objective lens of the ophthalmologic microscope and the eye to be inspected.
A front lens device, characterized in that the front lens inserted in the optical path of the observation optical system can be replaced by rotating the front lens support. The front lens device according to claim 1, wherein three or four front lenses are mounted on the front lens support so as to be rotationally symmetric. The front lens according to claim 1 or 2, wherein the front lens is attached to the front lens support so that the distance from the objective lens of the ophthalmologic microscope is different from each other. Device. The front lens device according to claim 3, wherein the front lens is attached to the side to be inspected as the focal length is shorter. The front lens is arranged by shifting the position of at least two of the front lenses in the optical axis direction of the observation optical system by the difference in the length of the focal length of the front lens. , The front lens device according to claim 4. In an ophthalmic microscope having an observation optical system for observing the eye to be inspected,
An ophthalmic microscope comprising the front lens device according to any one of claims 1 to 5. The present invention is characterized by having an objective auxiliary lens that is removable on the optical axis of the observation optical system and is used for adjusting the focal position on the side to be examined with respect to the objective lens of the observation optical system. 6. The ophthalmic microscope according to 6. The ophthalmologic microscope according to claim 7, wherein the objective auxiliary lens is a lens having a negative power. The ophthalmologic microscope according to claim 7 or 8, further comprising a switching mechanism for inserting or detaching the objective auxiliary lens in conjunction with the insertion or detachment of the front lens. The ophthalmologic microscope according to any one of claims 7 to 9, wherein the number of the front lenses is n (n ≧ 2), and the microscope has at least n objective auxiliary lenses.

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