JPH02268735A - Ophthalmic stereoscopic measuring apparatus - Google Patents

Abstract

PURPOSE:To detect the position of an object regardless of the direction or size of a slit like index by rotating the slit like index projected on the eyeground on the eyeground. CONSTITUTION:The luminous flux from a light source 1 passes through a slit like index S to reach a perforated mirror 5 through a relay lens 4 and is reflected by the perforated mirror 5 to reach the cornea Ec of an eye E to be examined and reaches the eyeground Ef through the pupil Ep to form a slit like index image. The reflected light from the eyeground Ef is emitted from the eye E to be examined to pass through an objective lens 6 and passes through the perforation part of the mirror 5 while forms an aeral image F' to reach an image receiving means 9 through a focusing lens 7 and a projection lens 8. The image received by the image receiving means 9 is inputted to an image processor 10 to be subjected to image processing and measurement to be displayed on a television monitor 11. The trigger signal from a trigger signal generator 12 is emitted by the signal from the image processor 10 and a pulse motor is driven to rotate an index projection optical system 3 and an image is taken in the image processor 10 through an image receiving means 9.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is an ophthalmological stereoscopic measurement device that projects an index onto the fundus of an eye to be examined and performs three-dimensional measurement of the fundus based on the deformed state of the index projected onto the fundus. It is related to.

[Prior Art] Conventionally, a plurality of slit-shaped indicators having a length in a direction perpendicular to the eccentric direction of the opening as shown in FIG. An apparatus has been proposed that projects S from a predetermined direction and performs three-dimensional measurement of the fundus from the deformed state of the slit.

[Problems to be Solved by the Invention] However, according to this conventional method, it is impossible to measure an object that exists in a certain direction, that is, in a direction perpendicular to the slit-shaped index S. That is, as shown in FIG. 5, among the blood vessels A and B extending from the papilla, blood vessel A that is almost perpendicular to the slit-like mark S is measured as a deviation, but blood vessel B that is almost parallel to the slit-like mark S is measured as a deviation. In this case, it is impossible to measure the lateral shift unless it is applied to the slit-like index S.

An object of the present invention is to eliminate the above-mentioned drawbacks and provide an ophthalmological stereoscopic measurement device that can obtain depth information regardless of the shape and size of blood vessels in the fundus.

[Means for Solving the Problems] In order to achieve the above object, the ophthalmological stereoscopic measurement device according to the present invention includes a photographing optical system for photographing the fundus of the eye to be examined, and a slit-like structure in the fundus of the eye to be examined. An ophthalmology clinic comprising an index projection optical system for projecting an index, an image receiving means for receiving an index image projected onto the fundus of the eye via the photographing optical system, and a calculation means for taking in image information from the image receiving means and calculating unevenness. The target projection system is located at a position optically substantially conjugate with the pupil of the eye to be examined, and includes a mask means having an aperture eccentrically provided with respect to the center of the pupil, and a mask means perpendicular to the eccentric direction of the aperture. The present invention is characterized by comprising a rotating means for rotating an index plate provided with the slit-shaped index having a length in the direction approximately about the center of the pupil.

[Operation] The ophthalmological stereoscopic measurement device having the above configuration can detect the position of an object regardless of its direction or size by rotating the slit-shaped index projected onto the fundus of the eye to be examined on the fundus.

[Example] The present invention will be explained in detail based on the example illustrated in FIGS. 1 to 3.

FIG. 1 is a block diagram of the present invention, in which 1 is a light source, and along the light flux emitted from the light source 1, a condenser lens 2
．． Index projection optical system 3, relay lens 4, perforated mirror 5
is arranged, and the light beam is reflected to the left by the perforated mirror 5 and enters the eye E through the objective lens 6.

The target projection optical system 3 includes an aperture stop plate 3a in the optical axis direction.

It is composed of a relay lens 3b and a slit-shaped index plate 3C, forming an index projection optical system whose optical axes coincide with each other in the arrangement shown in FIG. 2, and which can rotate integrally around the optical axis. It looks like this. The reflected light from the subject's eye E travels to the right and passes through an objective lens 6 and a perforated mirror 5, and behind the perforated mirror 5 there is a focusing lens 7, a photographing lens 8, an image receiving device such as a two-dimensional COD, etc. Means 9 are arranged. Further, the output of the image receiving means 9 is integrated t1i to the image processor IO, and this image processor 10
is connected to a television monitor 11 and a trigger signal generator 12.

The light beam from the light source 1 passes through the condenser lens 2, and then passes through the aperture diaphragm plate 3a, which has an aperture P deviated from the optical axis.
leading to. The light passing through this aperture P passes through the relay lens 3b,
A slit-shaped indicator plate 3c having a slit-shaped indicator S having a length '' in a direction perpendicular to the direction of deviation of the aperture P is reached. The light that has passed through the slit-like index S passes through the relay lens 4 and reaches the perforated mirror 5, but the light reflected by the perforated mirror 5 passes through the objective lens 6, reaches the cornea Ec of the eye E, and passes through the pupil Ep. It reaches the fundus Ef and forms a slit-like index image. On the other hand, the reflected light from the slit-shaped index image on the fundus Ef passes through the objective lens 6 again after exiting the eye E to be examined.
- Once the aerial image F' is formed, it passes through the hole of the perforated mirror 5 and reaches the image receiving means 9 through the focusing lens 7 and photographing lens 8. The image received by the image receiving means 9 is input to an image processor 10, subjected to one-image processing and measurement, and then displayed on a television monitor 11.

Fig. 3 shows a state in which a slit-like index S is projected onto the fundus Ef, especially the fundus Ef including the papilla. Since the slit-shaped index image S'' is curved, the image processor 10 measures and calculates the amount of the curved displacement.

The depth of the concavity on this slit-shaped index image S can be known. Next, when the index projection optical system 3 is rotated by a predetermined amount, the slit image becomes S'''; The amount of depression on the image S'' can be measured by the same means as described above. Furthermore.

The same goes for the case of applying the next rotation, and eventually measurement in the meridian direction becomes possible.

In the above-mentioned specific configuration, a trigger signal is generated from the trigger signal generator 12 in response to a signal from the image processor 10, and a pulse motor (not shown) is driven to rotate the target projection optical system 3. An image is taken into an image processor 10 via an image receiving means 9. Note that it is also possible to capture images corresponding to each rotation into a frame memory or the like stored in the image processor 10, and to process them together later, including interpolation of information between the captured images.

[Effects of the Invention] As explained above, the ophthalmological stereoscopic measurement device according to the present invention can scan the fundus almost continuously, and can also perform noise correction by averaging, and can detect the shape and size of the object on the fundus. The advantage is that the depth position can be accurately measured regardless of the depth.

[Brief explanation of drawings]

Drawings 1 to 3 show an embodiment of the ophthalmological stereoscopic measuring device according to the present invention, in which Fig. 1 is a configuration diagram, Fig. 2 is a schematic diagram of the index projection optical system, and Fig. 3 is a fundus. It is an explanatory diagram of the above slit-shaped index, and FIG. 4 is a layout diagram of the conventional slit-shaped index,
FIG. 5 is an explanatory diagram of a slit-shaped index image on the fundus according to a conventional method. Symbol l is a light source, 2 is a condenser lens, 3 is an index projection optical system, 3a is an aperture stop plate, 3b is a relay lens, 3C is an index plate, 4 is a relay lens, 5 is a perforated mirror, 6 is an objective lens, 7 8 is a focusing lens, 8 is a photographic lens, 9 is an image receiving means, 10 is an image processor, 11 is a television monitor, and 12 is a trigger signal generator. Patent applicant Canon Co., Ltd. Figure 3 Figure 4 15m

Claims (1)

[Claims] 1. A photographing optical system for photographing the fundus of the eye to be examined, an index projection optical system for projecting a slit-shaped index onto the fundus of the eye to be examined, and an image receiving means for receiving the index image projected onto the fundus through the photographing optical system. and a calculation means for taking in image information from the image receiving means and calculating unevenness, wherein the index projection system is located at a position substantially optically conjugate with the pupil of the eye to be examined, and is located at the center of the pupil. mask means having an opening eccentrically provided with respect to the opening, and rotation means for rotating an index plate provided with the slit-shaped index having a length in a direction perpendicular to the eccentric direction of the opening approximately around the center of the pupil. An ophthalmological stereoscopic measurement device featuring: