JPS6317454Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a binocular ophthalmoscope equipped with a fundus photographing device, and particularly to an ophthalmoscope equipped with a photographing index.

Binocular ophthalmoscopes equipped with a fundus photographing device for examining and photographing the fundus include the one disclosed in Japanese Utility Model Application No. 59-55503, which was previously proposed by the present applicant. In other words, the reflected light of the illumination light irradiated into the eye to be examined is divided into photographing light and observation light by a half mirror, and the fundus is diagnosed using the observation light, and the photographing light is used to take pictures as necessary. It is.

In an ophthalmoscope with such a configuration, the optical axes of the photographing light and observation light separated by the half mirror 3 are configured to coincide with the center of the photographic film or the eyepiece, respectively. If the person's eye deviates from the center of the eyepiece, the center of the visual field observed through the eyepiece will no longer coincide with the center of the image formed on the photographic film. Therefore, when photographing, it is essential to capture the retinal image at the center of the observation field, but since this is done by visual measurement, it is difficult to ensure accuracy and it is difficult to accurately capture the photographic range.

In view of the above circumstances, the present invention aims to provide a binocular ophthalmoscope equipped with a fundus photographing device that can easily align the centers of an observed image using an observation light and a photographed image using a photographing light. At the center of the optical path of the separated observation light, a target with photographic indices formed on the left and right sides and a finder lens are installed on the observer's side of the target, and the index image on the left side of the target is observed through the finder lens. The system is configured such that the index image on the left side of the visual field of the observer's right eye side and the right index image are seen on the right side of the visual field of the observer's left eye side, overlapping with the retinal image, respectively, and these index images indicate the imaging range and its center. This is what I did.

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

The illustrated ophthalmoscope uses an aspherical lens 2 to reflect light reflected from the retina 1a of irradiated light from a light source A to the eye 1 to be examined.
The transmitted light is used as observation light to pass through a pair of tilted mirrors 4.
a, 4a, 4b, 4b, and the eyepiece lens 5
a and 5b, and the light reflected by the half mirror 3 is introduced into the photographing mechanism as photographing light for photographing. In other words, after passing through the photographing lens group 6, it is reflected by the mirror 7 and the light is reflected on the film surface. 8.

A target 9 and a finder lens 10 are installed at the center (on the optical axis) of the optical path of the observation light between the half mirror 3 and the mirrors 4a and 4b. The target 9 and the finder lens 10 are fixed to the front and rear ends of one lens barrel, respectively, and are integrated, and are installed by fixing the lens barrel to the inner wall that forms the observation light path of the apparatus. It is.

As shown in FIG. 3, the target 9 has substantially isosceles triangular indicators 9a and 9b that can transmit light, arranged on the left and right with their apex angles (tips) facing the center of the optical axis, respectively, and the indicators 9a and 9b portions. Other than that, light cannot pass through. The indicators 9a and 9b are arranged on the horizontal center line of the photographing range by the photographing mechanism, and the interval between their apex angles is the interval that approximately represents the photographing range when viewed from the observer side through a finder lens 10, which will be described later. It's summery.

The finder lens 10 is a convex lens having a predetermined focal length, and is placed on the eyepiece lens 5a, 5b side at a distance equal to the focal length of the target 9. Therefore, when the target 9 is illuminated by the observation light that has passed through the half mirror 3, the light is transmitted only through the indicators 9a and 9b, and from the observer's side, the light is seen from the finder lens 1 overlapping the retinal image.
Bright images of the indices 9a and 9b are now observed through 0.

Further, the light transmitted through the index 9a on the left side of the target 9 is directed to the mirror 4 by the finder lens 10.
The parallel light beam is configured to become parallel light that travels from the left direction of the right eyepiece lens 5b to the right direction via the eyepiece lens 5b. Note that the index 9b on the right side of the target 9 is vignetted due to the relationship between the diameter of the finder lens 10 and the mirror 4a, and cannot be seen through the eyepiece lens 5a on the left side.

Similarly, the light transmitted through the index 9b on the right side of the target 9 is configured to become parallel light directed from the right direction to the left direction of the left eyepiece lens 5a via the mirrors 4a by the finder lens 10. There is. As mentioned above, if the left index 9a is not visible from the eyepiece 5a side, the target 9
The indicator 9b on the right side is not visible through the eyepiece lens 5b.

The ophthalmoscope constructed as described above operates as follows during observation and photographing.

Retina 1a of irradiated light from light source A to subject's eye 1
The reflected light passes through the aspherical lens 2 and reaches the half mirror 3, where it is separated into photographing light and observation light.

The observation light is divided into left and right halves by mirrors 4a, 4a and 4b, 4b. The observer observes the observation light passing through the eyepieces 5a and 5b as a retinal image with both eyes.

Further, part of the observation light illuminates the target 9, thereby causing bright images of the indicators 9a and 9b to overlap with the retinal image and appear within the observer's visual field as described above.

That is, as shown in Figure 5, the right eyepiece 5b
(to the observer's right eye), target 9
The image of the index 9a on the left side of the target 9 appears on the left side of the field of view (R in the figure), and the image of the index 9b on the right side of the target 9 appears on the right side of the field of view through the left eyepiece 5a (to the observer's left eye). (L in the figure).

At this time, the indicator 9 recognized by both eyes of the observer
The tips of images a and 9b point to the optical axis position O (that is, the center of the photographing range), and the distance between the tips indicates approximately the photographing range S (B in the figure).

In this way, the pattern of the photographing index is observed together with the retinal image, and the width between the left and right sides indicated by the tips of the indexes 9a and 9b and the vertical position within the observation field are determined on the film surface 8, respectively. Since it indicates the horizontal width and the vertical center of the range of the retinal image to be photographed, the photographing range can be accurately selected and understood from the position of the photographing index in these observation systems. Note that the indicators 9a and 9b can be seen as bright images, so visibility is good.

Furthermore, since the left index 9a of the target 9 is configured to be checked only through the right eyepiece 5b, and the right index 9b is checked only through the left eyepiece 5a, the target 9 can be made smaller (the index (The distance between the tips of 9a and 9b can be made smaller)
In addition, the diameter of the finder lens 10 may be small, so that the amount of attenuation of the observation light due to being blocked by the target 9 and the finder lens 10 can be minimized, and the observation of the retinal image is not obstructed. It is.

Furthermore, a target 9 and a finder lens 10
are installed in the observation optical system after passing through the half mirror 3, so the reflected light from the half mirror 3 (i.e., photographing light) forms an image on the film surface 8 without being affected by them at all. Therefore, the indicators 9a and 9b are not imprinted on the photographed image, and a clear retinal photographed image can be obtained.

As described above, according to the binocular ophthalmoscope with a fundus photographing device according to the present invention, the center position of the photographed image by the photographing light, that is, the center of the optical axis, can be grasped in the observed image by the observation light, and it coincides with the observed image. It is possible to obtain a captured image. That is, it is possible to accurately grasp the photographing range within the observed image.

It should be noted that the shapes of the indicators 9a and 9b of the target 9 are not limited to the above embodiments, but can be changed as appropriate.

[Brief explanation of the drawing]

Fig. 1 is a side view of the optical system arrangement showing an embodiment of a binocular ophthalmoscope with a fundus photographing device according to the present invention, Fig. 2 is a top view thereof, and Fig. 3 is a photographic index of a target viewed from the eyepiece side. FIG. 4 is an optical path diagram of a photographic index, and FIG. 5 is a diagram showing an observation field of view. 1... Non-optometry, 1a... Retina, 2... Aspherical lens, 3... Half mirror, 5a/5b... Eyepiece, 8... Film surface, 9... Target,
9a, 9b...index (photographing index), 10...finder lens.

Claims (1)

[Scope of utility model registration request] Light is irradiated into the subject's eye, the reflected light from the retina of the irradiated light is separated into observation light and photographing light, and a retinal image is taken by the photographing light, and the retinal image is obtained by dividing the observation light into left and right parts. The object is observed by an observer with both the left and right eyes, and in the center of the optical path of the observation light after being separated into the observation light and the photographing light, there is a target with photographing indicators formed on the left and right sides indicating the photographing range and its center, and a viewfinder. A lens is installed, and through the finder lens, the left index image of the target is displayed on the left side of the visual field of the observer's right eye, and the right index image is displayed on the right side of the visual field of the observer's left eye, respectively, as a retinal image. A binocular ophthalmoscope with a fundus photographing device, characterized in that it is configured so that overlap can be recognized.