JPH1189798A - Ophthalmic observation device - Google Patents

Abstract

(57) [Problem] To provide an in-focus and oblique illumination type ophthalmic observation device capable of changing a light guide angle and reducing flare. I do. An observation optical system having an observation unit for observing an eye to be inspected through an objective lens, a focusing lens for focusing an image of the eye to be inspected on the observation unit, and illumination light. An illumination light source 11 that emits light and a reflection mirror 14 that reflects illumination light from the illumination light source 11 and guides the illumination light to the eye 1 through an objective lens 21 at an angle different from the optical axis of the observation optical system 20. By moving the reflection mirror 14 in the ophthalmic observation apparatus provided with the illumination optical system 10 having
An angle changing unit 30 that changes the position of the reflection mirror 14 so as to change the light guide angle θ of the illumination light to the subject's eye 1 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmic observation apparatus for observing an eye to be examined, and more particularly to an ophthalmic observation apparatus having a structure for illuminating the eye to be examined.

[0002]

2. Description of the Related Art There are various ophthalmologic observation apparatuses for observing the fundus of an eye to be examined, such as an indirect mirror and a direct image mirror. Among such ophthalmic observation devices, the focusing method is an inner focus method in which a focusing lens inside the device is moved in the optical axis direction,
In addition, an illumination method for an eye to be inspected is provided which is an oblique illumination type in which illumination light is guided to an eye to be inspected at an angle different from the optical axis of an observation optical system, and this is generally called a large ophthalmoscope. I have. As shown in FIG. 18, the large ophthalmoscope has an objective lens 100 and an eyepiece 1 for observing the eye 1 to be examined through the objective lens 100 and the focusing lens 102.
01, an observation optical system having a focusing mirror 106, and an illumination optical system having an illumination light source 103 that emits illumination light, and a reflection mirror 104 that reflects illumination light of the illumination light source 103 toward the subject's eye 1. Have been. The reflection mirror 104 of the illumination optical system guides the illumination light from the illumination light source 103 to the eye 1 at an angle different from the optical axis 105 of the observation optical system.

[0003]

In general, when the angle between the optical axis 105 of the observation optical system and the optical axis 107 of the illumination optical system (hereinafter, simply referred to as “light guide angle”) becomes small, the illumination light flux becomes smaller. The overlapping range of the observation light beam becomes large, and the flare generated when this overlapping range overlaps with the lens surface of the eye 1 to be examined also becomes large. When the flare becomes large in this way, the observation light becomes turbid due to the flare, and observation becomes difficult.
It is desirable to make the light guide angle as large as possible so as not to cause flare.

[0004] When observing the fundus of the eye 1 to be examined, mydriasis observation in which the pupil of the eye 1 to be examined is widened by administering to the subject, and mydriasis observation in which the medication is not performed. And non-mydriatic observation in which observation is performed in a state where the pupil has a normal size. In mydriatic pupil observation, the pupil of the subject's eye 1 is wide open, so that the illumination light reaches the fundus of the subject's eye 1 without being blocked by the iris even if the light guide angle is increased. However, in non-mydriatic observation, since the pupil of the eye 1 to be examined is small, if the light guide angle is increased as in the case of mydriatic observation, the illumination light is blocked by the iris and does not reach the fundus of the eye 1 to be inspected.

[0005] From these facts, in order to make the illumination light reach the fundus of the eye 1 to be examined and to minimize the flare, it is necessary to guide the illumination light at a light guide angle suitable for each observation. For this purpose, it is necessary to change the light guide angle between mydriatic observation and non-mydriatic observation.

However, in an ophthalmic observation apparatus such as a large ophthalmoscope shown in FIG. 18, a reflection mirror 10 of an illumination optical system is used.
Since No. 4 was fixed at a position away from the optical axis 105 of the observation optical system, the light guide angle could not be changed between the case of mydriatic observation and the case of non-mydriatic observation. Therefore, the user needs to have both a large ophthalmoscope having a light guide angle suitable for mydriatic observation and a large ophthalmoscope having a light guide angle suitable for non-mydriatic observation. Alternatively, if both large ophthalmoscopes cannot be held, it is necessary to perform mydriatic observation with, for example, a large ophthalmoscope suitable for non-mydriatic observation. In this case, flare occurs because the light guide angle cannot be large. And the observation becomes difficult.

As described above, in non-mydriatic pupil observation, it is necessary to make the light guide angle small. However, when the light guide angle is made small, the flare becomes large as described above, and the observation light becomes turbid. Sometimes it was difficult. However, in the conventional large ophthalmoscope, a means for reducing the flare is not particularly provided, and the user has requested an improvement.

The present invention has been made in order to solve the problems of the conventional ophthalmic observation apparatus, and provides an ophthalmic observation apparatus capable of changing a light guide angle and reducing flare. The purpose is to:

[0009]

In order to solve the problems in such a conventional ophthalmic observation apparatus, the present invention according to the first aspect of the present invention provides an observation section for observing an eye to be inspected through an objective lens, An observation optical system having a focusing lens that focuses the image of the eye to be inspected on the unit, an illumination light source that emits illumination light, and an illumination light from the illumination light source having an angle different from the optical axis of the observation optical system. And an illumination optical system having a light guide means for guiding the eye to the subject's eye via the objective lens, wherein the light guide means is moved, and a light guide angle of the illumination light with respect to the subject's eye. And angle changing means for changing the angle.

According to a second aspect of the present invention, in the first aspect of the present invention, the angle changing means sets the light guide angle to an angle suitable for illuminating the fundus of the eye to be examined in a mydriatic state. Or an angle suitable for illuminating the fundus of the subject's eye in a non-mydriatic state.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the illumination range of the illumination light is narrowed to a position substantially conjugate with the fundus of the eye to be examined in the illumination optical system. And an illumination field stop having first and second openings having different shapes from each other.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the light guide angle is set to an angle suitable for illuminating a fundus of the eye to be examined in a mydriatic state by the angle changing means. When being changed, the illumination range of the illumination light is narrowed through the first opening of the illumination field stop, and the light guide angle is adjusted by the angle changing means to the fundus of the eye to be examined in the non-mydriatic state. When the angle is changed to an angle suitable for illuminating the illumination field stop, the angle changing means and the illumination field stop are interlocked so that the illumination range of the illumination light is reduced through the second opening of the illumination field stop. This is characterized in that it is provided with an interlocking means for causing it to operate.

According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, there is provided a pupil diameter measuring means for measuring a pupil diameter of an eye to be inspected, and a measurement result of the pupil diameter measuring means. And a control unit that controls the angle changing unit based on the light guide angle calculated by the calculation unit.

According to a sixth aspect of the present invention, there is provided an observation optical system having an observation unit for observing an eye to be inspected via an objective lens, and a focusing lens for focusing the image of the eye to be inspected on the observation unit. An illumination light source that emits illumination light; and a light guide unit that guides the illumination light from the illumination light source to the eye to be inspected at an angle different from the optical axis of the observation optical system and through the objective lens. In an ophthalmologic observation apparatus including an optical system, the optical axis of the illumination light by the light guide means and the optical axis of the observation optical system so as to be suitable for illuminating the fundus of the subject eye in a non-mydriatic state The illumination light by the light guide means is set in a second plane substantially perpendicular to a first plane including the vertical angle so as to be suitable for illuminating a fundus of the eye to be examined in a mydriatic state. Horizontal angle between the optical axis of the optical system and the optical axis of the observation optical system It is configured as characterized in that a constant possible angle changing means.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of an ophthalmologic observation apparatus according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view showing the overall configuration of the ophthalmologic observation apparatus according to the present embodiment, FIG. 2 is a side view of the ophthalmologic observation apparatus shown in FIG. 1, and FIG. 3 is a plan view showing a mydriatic eye observation state. 6 is a plan view showing an observation state of a non-mydriatic eye, FIG. 6 is a view showing an angle changing unit of the ophthalmologic observation apparatus of FIG. 1, and FIGS. 7 and 8 are views mainly showing an illuminated diaphragm.

In FIG. 1, the present ophthalmologic observation apparatus includes an eye 1 to be examined.
The illumination optical system 10 and the observation optical system 20 are configured as a large ophthalmoscope for observing the fundus of the subject.
As shown in FIG. 2, the illumination optical system 10 includes an illumination light source 11 that emits illumination light, and an illumination field stop 1 that narrows the illumination light to a predetermined range.
2, a relay lens 13, and a reflection mirror 14 as light guide means for reflecting illumination light. The illumination light emitted from the illumination light source 11 is narrowed down to a predetermined range by passing through apertures 12 a to 12 c, which will be described later, of the illumination field stop 12, and is received via the relay lens 13, the reflection mirror 14, and the objective lens 21. The light is guided toward the optometry 1. These illumination light source 11, illumination field stop 12, relay lens 13,
The reflection mirror 14 and the objective lens 21 are housed integrally in the housing 15.

The observation optical system 20 includes an objective lens 21
, A focusing lens 23, and an eyepiece 22 as an observation unit for observing the subject's eye 1 via the objective lens 21 and the focusing lens 23. Light guided to the eye 1 by the illumination optical system 10 and reflected by the fundus of the eye 1 (hereinafter, “reflected light”) passes through the objective lens 21 and travels in the optical axis direction of the focusing lens 23. The movement focuses on the examiner's eye via the eyepiece 22. These objective lenses 21,
The housing 15 in which the focusing lens 23, the eyepiece 22, and the illumination optical system 10 are housed is integrally housed in the housing 24.

Here, the optical axis of the illumination light reflected toward the subject's eye 1 by the reflection mirror 14 shown in FIG.
As shown in FIG. 1, an observation optical system 20
The light guide angle θ is formed in a horizontal plane (in the same plane as the plane of FIG. 1) including the optical axis of FIG. Therefore, the illumination light reflected by the reflection mirror 14 and guided to the eye 1 through the objective lens 21 enters the fundus of the eye 1 at an angle θ ′ different from the optical axis of the observation optical system 20 ( Hereinafter, the light guide angle of the illumination light inside the subject's eye 1 will be distinguished from the light guide angle of the illumination light before being reflected by the reflection mirror 14 by indicating “′”.

In the present ophthalmic observation apparatus, the light guide angle θ
To change the light guide angle θ ′ by changing
An angle changing unit 30 as an angle changing unit is provided (details of the angle changing unit 30 will be described later). Specifically, the light guide angle θ ′ is the light guide angle θ′1 when observing the eye 1 in the mydriatic state, and the light guide angle θ ′ when observing the eye 1 in the non-mydriatic state. 2 (θ′1> θ′2). FIG.
Shows the observation state of the mydriatic eye. In FIG. 3, the subject's eye 1 is in a mydriatic state, the pupil surrounded by its iris 1a has a large diameter, and guides the illumination light to the subject's eye 1 at a light guide angle θ′1. Illumination light guided at the light guide angle θ′1 (FIGS.
In FIG. 5, the illumination light is indicated by reference numeral S1).
And reaches the outside of the subject's eye 1 as observation light (the observation light is indicated by reference numeral S2 in FIGS. 3 to 5).

FIG. 4 shows an observation state of a non-mydriatic eye.
In FIG. 4, the subject's eye 1 is in a non-mydriatic state, the diameter of the pupil surrounded by the iris 1a is small, and the light guide angle θ '
Cannot be made so large. Therefore, the illumination light has a light guide angle θ ′ smaller than the light guide angle θ′1.
2 is guided.

Thus, from the light guiding angle θ′1 to θ′2,
Alternatively, the change from θ′2 to θ′1 is performed by changing the angle
Is performed by changing the light guide angle θ from θ1 to θ2 or from θ2 to θ1. The angle changing unit 30 is disposed between the housings 15 and 24 as shown in FIG. FIG. 6A is a vertical sectional view of a main part of the angle changing unit 30, and FIG. 6B is a plan view of the angle changing unit 30.
In FIG. 6A, the angle changing unit 30 includes a rotating shaft 31 as a rotating unit and an operation lever 32. The rotating shaft 31 penetrates the housings 15 and 24, and rotatably engages the housing 15 with the housing 24. Rotary axis 3
Reference numeral 1 denotes a focal position of the objective lens 21, that is, a point P in FIG. The operation lever 32 is moved from the housing 15 to the housing 2
4, the tip of which is exposed to the outside via a groove 33 provided in the housing 24, and can be operated from the outside. As shown in FIG. 6B, the groove 33 is formed in an arc shape centering on the rotation center of the rotation shaft. By moving the operation lever 32 along the groove 33, the reflection mirror in the housing 15 is formed. The angle of 14 with respect to the eye 1 to be examined, that is, the light guide angle θ can be changed.

In particular, in the present ophthalmic observation apparatus, it is sufficient that the light guide angle θ can be changed between θ1 and θ2, and it is desirable that the light guide angle θ can be easily positioned at these two angles. Is provided. As shown in FIG. 6A, the click portion 40 includes one hole 41 provided in the housing 15, a spring 42 provided in the hole 41, and a housing 24 formed by the spring 42.
As shown in FIG. 6B, the sphere 43 is always pressed to the side, and four locking holes 44 to 47 provided in the housing 24.

The spherical body 43 pressed by the spring 42 has its end locked in one of the locking holes 44 to 47,
By this locking, the rotation of the housing 15 with respect to the housing 24 is regulated, and positioning is performed. Here, the four locking holes 44 to 47 have the light guide angles θ1, θ2, −θ2, and −θ1 respectively (the angles of minus “−” indicate the observation optical system 2).
A positive angle with respect to the optical axis of 0 indicates an angle that is symmetrical). For example, FIG.
As shown in (2), when the sphere is locked in the locking hole 44, the light guide angle is θ1, and when locked in the locking hole 45, the light guide angle is θ2.

The feature of the ophthalmologic observation apparatus according to the present embodiment is that a configuration for reducing flare is provided. Hereinafter, this configuration will be described. First, in the observation of the mydriatic eye shown in FIG. 3, since the light guide angle θ ′ can be made sufficiently large as described above, a good observation image can be obtained. On the other hand, in observing a non-mydriatic eye shown in FIG. 4, it is necessary to enter illumination light from a small pupil diameter, and it is necessary to reduce the light guide angle θ ′. as a result,
The overlapping area between the observation light and the illumination light and the portion where the lens surface overlaps become large, and flare occurs due to reflection on the lens surface (the overlapping area between the observation light and the illumination light causing the flare and the lens surface The overlapped portion is denoted by reference numeral F2 in FIG. 4). This flare makes observation light white and turbid, making observation difficult.

Here, in the ophthalmologic observation apparatus according to the present embodiment, as shown in FIG. 2, an illumination field stop 12 is provided between an illumination light source 11 and a reflection mirror 14. This illumination field stop 12 is shown in FIG. In FIG. 7A, the illumination field stop 12 is formed in a circular plate shape, and two circular openings 12a and 12b and one semicircular opening 12c are formed by cutting out a part thereof. The infrared transmission filter 12d is fitted into the opening 12b. The illumination field stop 12 is rotatable about its central rotation axis, so that any one of the openings 12a to 12c can be selectively arranged below the illumination light source 11 by this rotation.

As shown in FIG. 7A, when the opening 12a is disposed below the illumination light source 11, the center position of the opening 12a and the center position of the illumination light from the illumination light source 11 are different. Correspondingly, as shown in FIG. 7 (b), almost all of the illumination light emitted from the illumination light source 11 passes through the illumination field stop 12 and reaches the reflection mirror 14, where the light is guided toward the eye 1 to be inspected. Is done. This state is the state shown in FIGS.

Also, when the opening 12b is disposed below the illumination light source 11, the center position of the opening 12b corresponds to the center position of the illumination light from the illumination light source 11, and almost all of the illumination light is reflected by the reflection mirror. It reaches 14. However, since the infrared transmission filter 12d is fitted into the opening 12b, the illumination light becomes infrared light, passes through the illumination field stop 12, and is guided to the eye 1 to be inspected. This infrared light does not cause the subject to feel glare compared to normal illumination light, and therefore has a large pupil diameter even in a non-mydriatic eye by using an imaging device sensitive to infrared light for observation. Observation can be performed in a state.

On the other hand, as shown in FIG.
In a state where 2c is arranged below the illumination light source 11,
The center position of the straight side of the opening 12c corresponds to the center position of the illumination light from the illumination light source 11, and therefore, FIG.
As shown in FIG. 5, almost half of the illumination light emitted from the illumination light source 11 is blocked by the illumination field stop 12 and cannot pass therethrough, and only approximately half of the illumination light passes through the illumination field stop 12 to reach the reflection mirror 14, The light is guided toward the subject's eye 1. This state is shown in FIG.

In FIG. 5, the eye to be examined 1 is the same as in FIG.
Is a non-mydriatic eye and the light guide angle is θ′2. However, unlike FIG. 4, as described above, the aperture 12
Since c is used, the width of the illumination light S1 is approximately half (width in the paper direction of FIG. 4). Specifically, the width of the illumination light S1 reaching the fundus of the subject's eye 1 with respect to the fundus center is L1 + L1 = 2L1 in FIG.
It is one. For this reason, as shown in FIG. 5, flare caused by overlapping of the illumination light S1, the observation light S2, and the lens surface does not occur. Therefore, the observation light S2 is not turbid by the flare, and good observation is possible. However, when the illumination light S1 has a half width as described above, the observation area also becomes half.

Although the angle changing section 30 and the illumination field stop 12 which are the features of the present embodiment have been described above, these functions are not separate but correspond to each other, so that the effects can be further exhibited. is there. That is, at the time of mydriatic eye observation, the light guide angle is set to θ′1 and observation at a high angle of view is possible. In this case, the illumination light is reduced to half by the illumination field stop 12 or the infrared light is reduced. Therefore, the aperture 12a of the apertures 12a to 12c of the illumination field stop 12 is used. On the other hand, at the time of non-mydriatic eye observation, when the light guide angle is set to θ′2, the aperture 12 of the illumination field stop 12 is used in order to reduce the flare by reducing the illumination light to half.
c is used. However, even when observing a non-mydriatic eye, if the illumination light is infrared light through the opening 12b of the illumination field stop 12, the pupil diameter of the eye 1 to be examined is large, and observation at a high angle of view is possible. Therefore, the light guiding angle is θ ′ by the angle changing unit 30.
It is set to 1.

Although not shown, the angle changing section 30 and the illumination field stop 12 are linked by a well-known link mechanism. For example, when the angle changing unit 30 is operated by the operation lever, the operation of the angle changing unit 30 is sensed by a position sensor, and the illumination field diaphragm 12 is automatically rotated by a motor drive according to the sensed content. You may. To explain this interlocking operation more specifically, for example, the present apparatus is provided with a switch for switching between two modes, a “general observation mode” and an “infrared observation mode”, and the “general observation mode” is selected by this switch. The light guide angle is θ '
When it is set to 1, the opening 12a of the illumination field stop 12 is automatically set to the use state by interlocking, and when set to θ'2, the opening 12c is automatically set to the use state by interlocking. When the “infrared observation mode” is selected, the light guide angle is automatically set to θ′1, and the opening of the illumination field stop 12 is automatically set to 12b.

Next, a second embodiment of the ophthalmic observation apparatus according to the present invention will be described. However, parts that are not particularly described are the same as in the first embodiment described above, and the same components as those in the first embodiment are denoted by the same reference numerals. FIG. 9 is a side view showing the overall configuration of the present embodiment. In FIG. 9, the illumination light emitted from the illumination light source 11 of the illumination optical system 10 is stopped down by the illumination field stop 12, reflected by the reflection mirror 14 a or the reflection mirror 14 b, and reflected by the optical axis of the observation optical system 20. Are guided to the subject's eye 1 at different angles.

Here, as shown in FIG.
The illumination light reflected at a is incident on the objective lens 21 at the light guide angle θ1, and then is incident on the subject's eye 1 to be guided at the light guide angle θ ′.
1 reaches the fundus of the eye 1 to be examined. Also, the reflection mirror 14b
The illumination light reflected by the objective lens 2 at the light guide angle θ2
1 and then to the subject's eye 1 and the light guide angle θ′2
To reach the fundus of the eye 1 to be examined. In the present embodiment,
By thus switching and using the reflection mirrors 14a and 14b, the light guide angle θ is changed, and as a result, the light guide angle θ ′ is changed.

FIG. 10 shows the angle changing unit 5 in this embodiment.
FIG. 7A is a conceptual diagram illustrating a state where the reflection mirror 14b is used, and FIG. 7B is a state where the reflection mirror 14a is used. First, FIG. 11 shows the angle changing unit 30 as a perspective view. As shown in FIG. 11, the angle changing unit 30
The two reflection mirrors 14a and 14b are fixed to a substrate 51, and the substrate 51 is supported rotatably about a rotation axis 52. By rotating the substrate 51, one of the two reflection mirrors 14a and 14b can be selectively arranged on the optical axis of the illumination light source 11.

As shown in FIG. 10A, the reflection mirror 1
The arrangement position and angle of the reflection mirror 14b are determined so that the illumination light is guided by the reflection mirror 14b at the light guiding angle θ1 when the illumination light source 4b is arranged on the optical axis of the illumination light source 11. As shown in FIG. 10B, when the reflection mirror 14a is arranged on the optical axis of the illumination light source 11, the reflection mirror 14a guides the illumination light at the light guide angle θ2 by the reflection mirror 14a. Are determined. The angle changing unit 50 is provided on the rotation axis 5 of the substrate 51.
2, driven by a drive motor (not shown) engaged with
One of the reflection mirrors 14 a and 14 b is arranged on the optical axis of the illumination light source 11.

Next, a third embodiment of the ophthalmic observation apparatus according to the present invention will be described. However, parts that are not particularly described are the same as in the first embodiment described above, and the same components as those in the first embodiment are denoted by the same reference numerals. FIG. 12 is a plan view showing the overall configuration of the ophthalmic observation apparatus according to the present embodiment,
FIG. 13 is a side view of the ophthalmologic observation apparatus of FIG. 12, and FIG. 14 is a view for explaining a relationship among light guide angles Hθ ′, Vθ ′, and Gθ ′, which will be described later.

In the present embodiment, the light guide angle Hθ (horizontal angle) formed in a horizontal plane including the optical axis of the observation optical system 20 (within the plane of FIG. 12) and the optical axis of the observation optical system are included. A light guide angle G synthesized from a light guide angle (vertical angle) Vθ formed in a vertical plane (in a plane perpendicular to the plane of FIG. 12).
The illumination light can be guided by θ. Specifically, an angle changing unit 30 is provided similarly to the first embodiment, and thereby, as shown in FIG. 12, a light guide angle Hθ is formed in a horizontal plane including the optical axis of the observation optical system 20. Considering only the horizontal plane, the illumination light enters the fundus of the subject's eye 1 at the light guide angle Hθ ′. Further, in the present ophthalmic observation apparatus, as shown in FIG. 13, the reflection mirror 14 of the illumination optical system 10 is disposed above the optical axis of the observation optical system 20 in the figure, so that the optical axis of the observation optical system 20 is Is formed in the vertical plane including the following. If only the vertical plane is considered, the illumination light enters the fundus of the eye 1 at the light guide angle Vθ ′. Therefore, the illumination light is actually guided at the light guide angle Gθ obtained by combining the light guide angle Hθ and the light guide angle Vθ, and is incident on the fundus of the eye 1 at Gθ ′.

The relationship between Vθ ′, Hθ ′, and Gθ ′ will be described with reference to FIG. In FIG. 14, the optical axis of the observation optical system is represented by the X axis, the horizontal plane is represented by the XY plane, the vertical plane is represented by the XZ plane, and the fundus of the eye 1 is represented by the coordinate origin. The light guide angle Vθ ′ is X-Z plane, and the light guide angle Hθ ′ is X
Expressed on the −Y plane, the light guide angle Gθ ′ is as illustrated. Here, these Vθ ′, Hθ ′, and Gθ ′ are mutually shown in FIG.

(Equation 1) The relationship of

As shown in FIG. 13, in this embodiment, the light guide angle Vθ is a light guide angle θ2 suitable for non-mydriatic observation.
And only the light guide angle Hθ in FIG. 12 can be changed by the angle changing unit 30. Therefore,
First, if the angle changing unit 30 sets the light guide angle Hθ = 0, the light guide angle Gθ = Vθ = θ2, that is, the light guide angle Gθ ′ = Vθ ′ = θ′2, and the light guide suitable for non-mydriatic pupil observation The illumination light can be made incident on the fundus of the subject's eye 1 at the angle θ′2. Further, the light guide angle H is set by the angle changing unit 30.
If θ is an angle that satisfies the following equation 2, the light guide angle is θ1, and therefore, the illumination light can be made incident on the fundus of the eye 1 at a light guide angle θ′1 suitable for mydriasis observation. .

(Equation 2)

As described above, in this embodiment, the light guide angle V
θ is fixed to the light guide angle θ2, while the light guide angle Hθ is set to 0.
By changing the angle so as to satisfy Equation 2, it is possible to switch between a light guide angle suitable for non-mydriatic observation and a light guide angle suitable for mydriatic observation.

Here, since the light guide angle θ2 is set as a light guide angle suitable for non-mydriatic pupil observation, illumination light can enter the non-mydriatic pupil and a light flux of the observation optical system, that is, reflected light. It is desirable that the angle does not obstruct the light. Specifically, the light guide angle θ2 is set to about 6 degrees with respect to the optical axis of the observation optical system 20. On the other hand, since the light guide angle θ1 is set as a light guide angle suitable for mydriatic observation, it is desirable that the angle be such that illumination light can enter the mydriatic pupil and generate as little flare as possible. That is, the angle is set to the maximum angle among angles at which the illumination light can enter the mydriatic pupil. More specifically, the light guide angle synthesized when the light guide angle θ2 is about 6 degrees with respect to the optical axis of the observation optical system 20 and the light guide angle Hθ is about 13 degrees with respect to the optical axis of the observation optical system 20. The light angle θ1 is most suitable for mydriatic observation. Suitable for mydriatic observation

A specific basis for setting the light guide angle θ2 = about 6 degrees and the light guide angle Hθ = about 13 degrees will be described.
FIG. 17 is a diagram for explaining the relationship between the light guide angle and the pupil diameter. In FIG. 17, the optical axes of the objective lens and the subject's eye are indicated by chain lines, and the light guide path is indicated by solid lines. The pupil angle is represented by θ, the focal length of the objective lens is represented by L, and the radius of the pupil of the eye to be examined is represented by H. Here, when an objective lens having a lens power of 90D is used, the focal length L is L = 1000/90.
= About 11.1 mm. First, θ2 = about 6 degrees, light guide angle H
Assuming that θ = about 13 degrees, Equation 1 results in θ1 = 14.3 degrees. Here, in FIG. 17, H = Ltan θ, and when L = 11.1 and θ = 6 degrees are substituted into this equation, the pupil radius H = approximately
1.2mm. Since the value of the pupil radius H corresponds to a pupil radius of about 1 to 1.5 mm at the time of non-mydriasis obtained empirically, illumination light pupilized at θ2 = about 6 degrees enters the non-mydriatic eye. We can see that we can do it. L = 1 in the equation of H = Ltan θ.
Substituting 1.1, θ = 14.3 degrees, pupil radius H = about 2.8 mm
Becomes Since the value of the pupil radius H corresponds to a pupil radius of 2.5 to 4 mm at the time of mydriasis obtained empirically, it is understood that the illumination light can enter the mydriatic eye when Hθ = about 13 degrees.

Next, a fourth embodiment of the ophthalmic observation apparatus according to the present invention will be described. However, parts that are not particularly described are the same as in the first embodiment described above, and the same components as those in the first embodiment are denoted by the same reference numerals. FIG. 15 is a side view of the pupil diameter measuring unit 60. In this embodiment, the same illumination optical system 10, observation optical system 20, and angle changing unit 30 as those in the first embodiment are provided, but are omitted in FIG. As shown in FIG. 15, in the present embodiment, the pupil diameter measuring unit 6 for measuring the pupil diameter of the subject's eye 1
0 is provided. The pupil diameter measurement unit 60 includes a measurement light source 61, a lens 62, and a line sensor 63. The measurement light projected by the measurement light source 61 is reflected on the surface of the eye 1, and passes through the lens 62. Line sensor 63
Is received. Note that infrared light is used as the measurement light in the present embodiment. Therefore, even if the illumination light reflected by the fundus of the subject's eye 1 enters the line sensor 63, it can be removed as a noise component. Can be.

FIG. 16 is an explanatory diagram showing the mutual relationship among the eye to be examined, the line sensor, the amount of light received by the line sensor, etc. in the measurement of the pupil diameter. The line sensor 63 receives the measurement light reflected on the surface of the subject's eye 1, and based on the amount of received light, the subject's eye 1
For measuring the pupil diameter of a plurality of imaging devices, and is configured by juxtaposing a plurality of image sensors in a width substantially corresponding to the iris 1a of the subject's eye 1,
As shown in the upper part of FIG. 16, the center position in the width direction is arranged so as to correspond to the substantially center position of the pupil 1b. The relationship between the amount of light received by the line sensor 63 and the position of the subject's eye 1 is shown in the lower part of FIG. As shown in FIG. 16, the measurement light reflected by the pupil 1b of the subject's eye 1 is smaller than the measurement light reflected by the iris 1a. 1b
Since the light receiving amount of the portion corresponding to the light receiving amount becomes small, the pupil diameter of the eye to be inspected 1 can be measured by detecting the width W of the portion having the small light receiving amount.

In the present embodiment, based on the pupil diameter of the subject's eye 1 measured by the pupil diameter measuring unit 60 as described above, the light guide angle optimal for observation, that is, the light enters from the pupil and the flare is generated as much as possible The light guide angle not to be calculated is calculated by a light guide angle calculation means (not shown) provided in the apparatus, and the angle changing unit is provided by control means (not shown) provided in the apparatus so that the illumination light is guided at the light guide angle. 30 is controlled. Therefore, even when the pupil diameter of the subject's eye 1 fluctuates due to individual differences or the like, it is possible to always illuminate at the optimal light guide angle, and to always perform optimal observation automatically.

Although the first to fourth embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and may be implemented in various forms within the scope of the technical idea. These different modes will be described below. In the above embodiment, the case where the ophthalmic observation apparatus is a large ophthalmoscope has been described, but the present invention may be applied to all ophthalmic observation apparatuses. Further, the angle changing unit 30 is not limited to the above, and may be embodied using any known mechanism such as a servomotor.

The light guide angle is defined as a light guide angle θ ′ for mydriatic observation.
The case where the light guide angle is set to 1 or the light guide angle θ′2 for non-mydriatic observation has been described, but the present invention is not limited to these two angles, and for example, an angle from 0 to 45 degrees may be continuously taken. . Further, the illumination field stop 12 is not always necessary, and even when the illumination field aperture 12 is provided, the illumination field aperture 12 may be operated independently without being linked with the angle changing unit 30.

In the fourth embodiment, the line sensor 63 is used to measure the pupil diameter of the subject's eye 1. In addition, an image of the subject's eye 1 is taken by a general CCD camera.
The pupil diameter may be measured by image processing this image.

[0049]

As described above, the present invention according to the first and sixth aspects has an angle changing means for moving the light guide means and changing the light guide angle of the illumination light to the eye to be examined.
The illumination light can be guided at the most appropriate angle according to the state of the mydriasis, non-mydriasis, and the like of the subject's eye, and observation can be performed in an optimal state.

According to a second aspect of the present invention, the angle changing means sets the light guide angle to an angle suitable for illuminating the fundus of the subject eye in a mydriatic state or the fundus of the subject eye in a non-mydriatic state. Can be changed to any angle suitable for illuminating the illuminating light, so that the illuminating light can be guided at the most appropriate angle in accordance with the state of the mydriasis, non-mydriasis and the like of the eye to be inspected.

Further, the present invention according to claim 3 is for narrowing the illumination range of illumination light to a position substantially conjugate with the fundus of the eye to be examined in the illumination optical system, and has first and second shapes different from each other. By providing the illumination field stop having the above aperture, even when the light guide angle is small, the occurrence of flare can be suppressed by passing through the illumination field stop, and more favorable observation can be performed.

Further, according to the present invention, when the light guide angle is changed to an angle suitable for illuminating the fundus of the eye to be examined in the mydriatic state by the angle changing means, the illuminated field stop is adjusted. The illumination range of the illumination light is narrowed through the first opening, and
When the light guide angle is changed to an angle suitable for illuminating the fundus of the subject eye in the non-mydriatic state by the angle changing means, the illumination range of the illumination light through the second opening of the illumination field stop By providing the angle changing means and the interlocking means for interlocking the illumination field aperture, the light guide angle and the opening of the illumination field aperture are interlocked with each other, thereby saving the trouble of manually interlocking. Therefore, observation can be performed more easily.

According to a fifth aspect of the present invention, there is provided a pupil diameter measuring means for measuring a pupil diameter of an eye to be examined, and a calculating means for calculating a light guide angle based on a measurement result of the pupil diameter measuring means. And, by including a control means for controlling the angle changing means based on the light guide angle calculated by the calculation means, the optimal light guide angle for the eye to be examined is automatically calculated, the observation conditions automatically Can be optimized.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating a configuration of an ophthalmologic observation apparatus according to a first embodiment of the present invention.

FIG. 2 is a side view showing the overall configuration of the ophthalmologic observation apparatus of FIG.

FIG. 3 is a plan view showing an observation state of a mydriatic eye.

FIG. 4 is a plan view showing a state in which illumination light is not stopped in an observation state of a non-mydriatic eye.

FIG. 5 is a plan view showing a state in which illumination light is narrowed in a non-mydriatic eye observation state.

6A and 6B are diagrams showing an angle changing unit 30 of the ophthalmologic observation apparatus of FIG. 1, wherein FIG. 6A is a longitudinal sectional view of a main part, and FIG. 6B is a plan view of a main part.

FIGS. 7A and 7B are diagrams mainly showing an illumination field stop 12 of the ophthalmologic observation apparatus of FIG. 1, wherein FIG. 7A is a perspective view and FIG. 7B is a side view.

FIGS. 8A and 8B are diagrams mainly showing an illumination field stop 12 of the ophthalmologic observation apparatus of FIG. 1, wherein FIG. 8A is a perspective view and FIG. 8B is a side view.

FIG. 9 is a plan view illustrating a configuration of an ophthalmologic observation apparatus according to a second embodiment of the present invention.

10A and 10B are diagrams illustrating an angle changing unit 30 of the ophthalmologic observation apparatus in FIG. 9, wherein FIG. 10A is a side view of a main part when a light guide angle θ′2 is set, and FIG. It is a principal part side view in the case of setting.

11 is a perspective view of an angle changing unit 30 of the ophthalmologic observation apparatus of FIG.

FIG. 12 is a plan view illustrating a configuration of an ophthalmologic observation apparatus according to a third embodiment of the present invention.

FIG. 13 is a side view of the ophthalmologic observation apparatus of FIG.

FIG. 14 is an explanatory diagram showing the relationship among the light guide angles Hθ ′, Vθ ′, and Gθ ′.

FIG. 15 is a side view of a pupil diameter measuring unit.

FIG. 16 shows a subject's eye, a line sensor,
It is explanatory drawing which shows mutual relationship of a line sensor light-receiving amount etc.

FIG. 17 is a diagram for explaining a relationship between a light guide angle and a pupil diameter.

FIG. 18 is a configuration diagram of a conventional large ophthalmoscope.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Examinee eye 10 Illumination optical system 11 Illumination light source 12 Illumination field stop 13 Relay lens 14 Reflection mirror 20 Observation optical system 21 Objective lens 22 Eyepiece 23 Focusing lens 30 Angle changing part 40 Click part 60 Pupil diameter measuring part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiromasa Kato 3-2-2-3 Marunouchi, Chiyoda-ku, Tokyo Nikon Corporation

Claims (6)

[Claims] 1. An observation optical system having an observation unit for observing an eye to be inspected via an objective lens, a focusing lens for focusing the image of the eye to be inspected on the observation unit, and an illumination light source for emitting illumination light An illumination optical system comprising: an illumination optical system having illumination light from the illumination light source at an angle different from the optical axis of the observation optical system and guiding the illumination light to the subject's eye via the objective lens. An observation apparatus, comprising: an angle changing unit that moves the light guide unit and changes a light guide angle of illumination light with respect to the eye to be inspected. 2. The method according to claim 1, wherein the angle changing unit sets the light guide angle to an angle suitable for illuminating a fundus of the eye in a mydriatic state.
2. The ophthalmologic observation apparatus according to claim 1, wherein the angle can be changed to any one of angles suitable for illuminating the fundus of the eye in a non-mydriatic state. 3. An illuminator having first and second openings having different shapes for narrowing an illumination range of the illumination light at a position substantially conjugate with a fundus of the eye to be examined in the illumination optical system. The ophthalmologic observation device according to claim 1, further comprising a field stop. 4. When the angle changing means changes the light guide angle to an angle suitable for illuminating the fundus of the eye to be examined in a mydriatic state, the first opening of the illumination field stop is changed. When the illumination range of the illumination light is narrowed through and the angle guiding unit changes the light guide angle to an angle suitable for illuminating the fundus of the subject's eye in the non-mydriatic state, Interlocking means for interlocking the angle changing means and the illumination field stop so that the illumination range of the illumination light is narrowed through the second opening of the field stop,
The ophthalmic observation apparatus according to claim 3, further comprising: 5. A pupil diameter measuring means for measuring a pupil diameter of an eye to be examined, a calculating means for calculating the light guide angle based on a measurement result of the pupil diameter measuring means, and a calculating means for calculating the light guiding angle. The ophthalmologic observation apparatus according to any one of claims 1 to 4, further comprising: a control unit configured to control the angle changing unit based on the obtained light guide angle. 6. An observation optical system having an observation unit for observing an eye to be inspected via an objective lens, a focusing lens for focusing the image of the eye to be inspected on the observation unit, and an illumination light source for emitting illumination light An illumination optical system comprising: an illumination optical system having illumination light from the illumination light source at an angle different from the optical axis of the observation optical system, and light guiding means for guiding the illumination light to the subject's eye via the objective lens. In the observation device, a vertical angle between the optical axis of the illumination light by the light guide means and the optical axis of the observation optical system is set so as to be suitable for illuminating the fundus of the subject's eye in the non-mydriatic state, The optical axis of the illumination light by the light guide unit and the observation optics in a second plane substantially perpendicular to the first plane including the vertical angle so as to be suitable for illuminating the fundus of the eye to be examined in a mydriatic state. Angle change means that can set the horizontal angle with the optical axis of the system Girder that, ophthalmic observation apparatus according to claim.