JPH05123298A - Stereoscopic fundus camera - Google Patents

Abstract

PURPOSE:To execute an observation so as to be focused extending over the whole of a surface layer and a deep part of an eyeground and a vitreous body of this side, etc., by providing an image forming optical system in each optical path, respectively in which a reflected luminous flux from the eyeground is divided, so that both focusing lenses arranged therein form images of different object surfaces on each surface. CONSTITUTION:A reflected light by an eyeground passes through an objective lens, and thereafter, forms an intermediate image in A. This eyeground image is an inverted image. Thereafter, the light passes through a perforated mirror 12, and a luminous flux is divided into two left and right luminous fluxes by a two-hole diaphragm 15. Subsequently, by a luminous flux separating prism 16 immediately behind the two-hole diaphragm 15, the left and the right luminous fluxes are replaced and separated. The separated luminous fluxes are reflected by prisms 17a, (b), respectively, and thereafter, images are formed in B and B' on visual field diaphragms 25a, (b) of an eyepiece by a pair of image forming lens systems, that is, relay lenses 18a, (b), focusing lenses 19a, (b), and observation optical system image forming lenses 24a, (b). This eyeground image is an erecting image. A photographer observes this image, and executes a stereoscopic observation of the eyeground.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereoscopic fundus camera, and more particularly to a focusing device suitable for each of stereoscopic left and right images.

[0002]

2. Description of the Related Art Conventionally, a reflected light beam from the fundus entering through an objective lens is divided by a two-hole diaphragm, and each divided light beam is guided to a pair of image forming optical systems to enable simultaneous stereoscopic vision. Simultaneous stereoscopic fundus cameras have long been known (for example, David D. Donaldson "A NEW CAMERA FOR STEREOSCOP
IC FUNDUS PHOTOGRAPHY '' TR. AM. OPHTH. SOC., Vol.621
964, P437 ~). In this simultaneous stereoscopic fundus camera, in order to photograph a desired part of the fundus, it becomes a mechanism for obtaining left and right images of the same focus surface by a pair of focusing lenses provided in a pair of imaging optical systems. There is.

[0003]

The stereo image of FIG. 4 is an image of the papilla of the fundus, and the recessed shape, the running state of blood vessels, color information, and the like are targets of diagnosis in the papilla. This part is composed of a so-called cup (C) and a part called a disc (D) and a concave part in the middle, and has a three-dimensional shape as compared with other fundus parts. There is a difference in diagnostic value depending on whether the photograph is taken by focusing on the surface or the bottom of the recess. However, in the conventional apparatus, when the focus surface is adjusted to a specific part, the other part is out of focus, so that it is necessary to perform stereo photography a plurality of times by changing the focus position.

An object of the present invention is to provide an observer with a stereoscopic fundus camera capable of observing the surface layer of the fundus of the eye to be examined and the entire deep part of the fundus, the vitreous body in the foreground, and the like so as to be in focus. And

[0005]

In order to achieve the above object, the stereoscopic fundus camera of the present invention has the following features. (1) A reflected light beam from the fundus is divided into two light beams, and an imaging optical system is provided in each of the divided optical paths, and a stereoscopic fundus camera for stereoscopic observation or stereoscopic photography of the fundus is focused on the fundus of the eye to be examined. To this end, there are provided focusing lenses arranged in the respective imaging optical systems, and focusing means for focusing images of different object planes on the respective focusing lenses on predetermined surfaces. There is.

(2) The different object planes of (1) are characterized in that one is the retinal plane and the other is the anterior and posterior planes thereof, such as the retinal endothelium layer, the papilla concave surface or the vitreous body.

(3) The focusing means of (1) is characterized in that both focusing lenses are individually operated in order to connect each object surface to the predetermined surface.

(4) The focusing means of (1) is different from the first focusing means that operates the both focusing lenses in synchronization with each other to form an image of the same object plane, and a different object plane. Second individually actuating said focusing lenses to form an image of
It is characterized in that it has a focusing means and a selecting means for selecting which of the first focusing means and the second focusing means is to be operated.

(5) The first focusing means of (4) is characterized in that the second focusing means is configured to be connectable by a clutch.

[0010]

[Advantage] According to the present invention, a pair of images of images of different object planes can be obtained by moving the focusing lens arranged in each optical path of the reflected light flux from the fundus divided into two light fluxes to different positions. can get. In one of the pair of images, an image in focus in the foreground and out of focus is obtained, and in the other, an image in focus in the back and out of focus is obtained. By the way, when paying attention to the physiological action of each eye, when focusing on the part in focus, the image side with bokeh leaves only the physiological recognition for stereoscopic vision, and the appearance of the image is focused. It looks like the bokeh is canceled by being pulled by the person who fits. Therefore, under stereoscopic vision with both images, the images from the front to the back are observed as a focused image as a whole.

In consideration of the small deviation between the focus planes of the two, the first focusing means for operating the focusing lenses in synchronization with each other and the both focusing means for forming images of different focus planes. By selectively using the second focusing means that the focusing lens operates individually, quick focusing can be performed and an image of the same object plane as that of the conventional apparatus can be obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. [Structure] FIG. 1 is a schematic layout view of an optical system according to an embodiment of the present invention when viewed from the side, and includes an illumination optical system, a photographing optical system, and an observation optical system. FIG. 2 is a view of the optical system of FIG. 1 seen from above.

(Illumination optical system) 1 is a halogen lamp which is a light source for observation, 2 is a condenser lens, and 3 is a xenon flash lamp which is a light source for photographing. The halogen lamp 1 and the xenon flash lamp 3 are in a position conjugate with the condenser lens 2. Reference numeral 4 is a beam splitter, 5 is a relay lens, and 6 is an aperture stop. Reference numeral 7 is a mirror for changing the optical path, 8 is an illumination relay lens, 9 is a standard plate having a black spot 10 at the center for removing harmful light,
Reference numeral 11 is an illumination system relay lens, and 12 is a perforated mirror. The aperture stop 6 is composed of a ring-shaped slit, forms an intermediate image of the slit in the vicinity of the opening of the perforated mirror 12, reflects it by the perforated mirror 12, and then forms a slit image in the vicinity of the cornea by the objective lens 13. An image is formed and the fundus of the subject's eye 14 is illuminated.

(Photographing optical system) 13 is an objective lens, and 15 is a two-hole diaphragm. The two-hole diaphragm 15 is arranged so as to be conjugate with the pupil of the eye to be inspected and the objective lens 13, and the diaphragm divides the light flux into two. Numerals 16 and 17 are light beam separating prisms, and the light beam separating prism 16 is for replacing the left and right of the divided light beam, and the light beam separating prism 17 sets the divided light beam in parallel at a predetermined interval.

The light beam reflected by the fundus of the eye to be examined forms an inverted intermediate image at the point A by the objective lens 13 and then passes through the opening of the perforated mirror 12, and the two-hole diaphragm 15 and the light beam separating prisms 16 and 17 are formed. After passing through, the fundus image is formed on the film surface 22 by the relay lens 18, the focusing lens 19, and the imaging lens 21. Focus Sync Lens 19
Is movable in the optical axis direction and adjusts the refractive power of the eye to be inspected to focus the fundus image on the film surface 22. Reference numeral 20 denotes a flip-up mirror, which switches the optical paths of the photographing optical system and the observation optical system, and is synchronized with the light emission of the xenon flash lamp 3, and at the same time as the flip-up mirror 20 is flipped up in the arrow direction, the lamp 3 emits light. The shooting light flux from the fundus is guided to the film surface.

(Observation Optical System) The observation optical system is the objective lens 1
It is also used as an optical system of the taking optical system of the flip-up mirror 20. The observation light flux from the fundus guided through the objective lens 13 to the focusing lens 19 is reflected by the flip-up mirror 20, and then the optical path is further changed by the mirror 23. Observation system imaging lens 24, eyepiece field stop 2
5. The photographer 27 observes the fundus image of the eye to be examined through the eyepiece lens 26.

(Focusing Lens Driving Mechanism) FIG. 5 is a diagram showing a driving mechanism for the focusing lenses 19a and 19b. Reference numerals 30a and 30b are lens barrel portions 19a and 19b.
Reference characters a and b are rack gears for moving the lens barrel portions 30a and 30b back and forth, and reference characters 32a and 32b are pinion gears for driving the rack gears 31a and 31b. Pinion gears 32a, 32b
Is rotatably supported by knobs 33a, b outside the fundus camera housing, and slides left and right while meshing with each other within a range of the length of the pinion gears 32a, b in the tooth width direction with respect to the rack gears 31a, b. It is possible. Further, the clutch portion 3 that engages (or freely disengages) at a predetermined position between the both.
4a and 4b are provided, and the clutch portion is provided with a spring 35.
They are pressed against each other by a and b. The position where the clutch is engaged means the focusing lens 19
It is a position in which a and b move in parallel in order to focus on the same object surface at the same time. An example of clutch engagement is shown in FIG.

[Operation] In the embodiment having the above configuration,
The operation will be described. The optical system main body housed in the casing is placed on the movable table, and the movable table moves relatively to the fixed table by the sliding mechanism. The subject is fixed to the jaw stand that is fixed to the fixed base, and the halogen lamp 1 that is the light source for observation is turned on.
Illuminate the eye to be examined. The joystick operates the sliding mechanism to move the optical system back and forth, left and right and up and down, and the photographer aligns the image of the aperture stop 6 of the illumination system on the cornea with the pupil of the eye to be examined in a predetermined positional relationship. . When almost aligned, the illumination light illuminates the fundus.

The reflected light from the fundus passes through the objective lens and then A
To form an intermediate image. This fundus image is an inverted image. After that, the light beam passes through the perforated mirror 12, and the two-hole diaphragm 15 splits the light beam into two right and left light beams. Next, the light beam separating prism 16 immediately after the two-hole diaphragm 15 interchanges and separates the left and right light beams. The separated light fluxes are reflected by the prisms 17a and 17b, respectively, and then the pair of imaging lens systems, that is, the relay lens 18
a, b, focusing lenses 19a, b, observation optical system imaging lenses 24a, b, and a field diaphragm 25 of an eyepiece.
An image is formed on B and B'on a and b. This fundus image is an erect image. The photographer can observe the fundus three-dimensionally by observing this image.

In normal stereoscopic photography, the same object plane is focused. This achieves a general shooting purpose. In this case, the focus knob 33a (or 33b) is rotated with the clutches 34a, b engaged (the clutch is engaged unless the focus knob is pulled in the axial direction) to rotate the focusing lens 19a,
b is moved synchronously. While observing the left and right images, the photographer adjusts the focus to the best focus position and at the same time finely adjusts the alignment so that there is no flare.
When alignment and focusing are completed and the shooting button is pressed, the flip-up mirror 20 in the shooting system is flipped up in synchronization with it and the xenon flash lamp 3 emits light.
The captured images on the left and right of the film surface are images that focus on the same object surface. The fundus images thus photographed are a pair of stereo images as shown in FIG.

Next, the case where the right and left object surfaces are focused will be described. Here, an example will be described in which one of the left and right images is focused on the surface layer and the other is focused on the bottom of the recess to perform simultaneous stereoscopic photography. First,
Focus knob 3 without pulling the focus knob in the axial direction
3a (or 33b) is rotated to move the focusing lenses 19a and 19b in synchronization. At this time, both of them focus on the same object surface, so they are focused on the surface layer.
Next, the focus knob 33a (or 33b) is pulled in the axial direction to release the clutch, and one of the focus knobs is further rotated to focus on the bottom of the recess. at this point,
The left and right images are two images with one on the surface and the other on the recess, so if you press the shooting button according to the operation of the fundus camera in this state, the film will focus on different object planes. A pair of stereo images connecting the two are obtained. When the knobs 33a (or b) are rotated so that the clutches 34a and 34b are brought into a meshing position, the original meshed state can be automatically restored by the pressure contact of the spring.

The above embodiment can be variously modified,
In this embodiment, the focusing lens is driven by a mechanical mechanism, but the focusing lens may be driven (interlocked or independently moved) by electrical control. Further, in order to obtain a pair of stereo images of different object planes in advance, the two focusing lenses may be moved to a position that is out of focus by a predetermined amount (average shift amount). Obviously, changes such as replacement of the observation system with a monitor observation system are possible, and it goes without saying that these changes are also included in the present invention as long as the technical idea is the same.

[0023]

According to the present invention, since the left and right focusing lenses can be moved to different positions, a stereoscopic image in focus can be obtained from the front side to the back side of the fundus if necessary. Also, since it is only necessary to correct and move the focus slightly, quick focusing is possible, and since an image of the same object plane and a different object plane image can be freely selected,
The range of use of the device is expanded.

[Brief description of drawings]

FIG. 1 is a layout view of an optical system of an apparatus according to an embodiment when viewed from the side.

FIG. 2 is a layout view of the optical system of the apparatus of the embodiment as seen from above.

FIG. 3 is a diagram showing a photographed fundus image.

FIG. 4 is an image of the papilla of the fundus.

FIG. 5 is a diagram showing a drive mechanism of a focusing lens.

FIG. 6 is a view showing meshing of clutches.

[Explanation of symbols]

 15 Two-hole diaphragm 16,17 Light beam separating prism 19a, b Focusing lens 34a, b Clutch

Claims (5)

[Claims] 1. A light beam reflected from the fundus is divided into two light beams,
An imaging optical system is provided in each of the divided optical paths, and in a stereoscopic fundus camera for performing stereoscopic observation or stereoscopic photography of the fundus, a focusing arranged in each of the imaging optical systems for focusing on the fundus of the eye to be examined. A stereoscopic fundus camera, comprising: a lens; and focusing means for forming images of different object planes on the respective predetermined planes on the respective focusing lenses. 2. The stereoscopic fundus camera according to claim 1, wherein one of the different object surfaces is a retinal surface and the other is anterior and posterior surfaces thereof, for example, a retinal endothelium layer, a nipple depression surface or a vitreous body. 3. The stereoscopic fundus camera according to claim 1, wherein the focusing means individually actuates both focusing lenses in order to connect each object surface to the predetermined surface. 4. The focusing means according to claim 1, wherein the first focusing means for operating the both focusing lenses in synchronization to form an image of the same object plane is different from the first focusing means. It has a second focusing means for individually operating the both focusing lenses to form an image, and a selection means for selecting which of the first focusing means and the second focusing means is operated. A stereoscopic fundus camera that is characterized. 5. The first focusing means of claim 4 is the second focusing means.
A stereoscopic fundus camera characterized in that the focusing means is connectable with a clutch.