JPH1128191A - Ophthalmic equipment - Google Patents

Abstract

(57) [Problem] To provide an ophthalmologic apparatus capable of removing flare with a simple configuration. A fundus of an eye to be examined is illuminated via a linear polarizing plate 16 of an illumination optical system, and a fundus image of the fundus image is taken.
Is taken through. The imaging optical system includes a linear polarizing plate 16.
A linear polarizing plate 31 whose polarization direction is substantially orthogonal is disposed. The linearly polarized reflected light from the objective lens 20 or the cornea or the crystalline lens of the eye to be examined is effectively cut by the polarizing plate 31 of the imaging optical system, and is not formed as a flare on the image plane 40. On the other hand, the linearly polarized light incident on the fundus is irregularly reflected on the fundus, and the polarized light is also random polarized light, so that it can pass through the polarizing plate 31 of the imaging optical system, and a good fundus image without flare is formed on the image plane 40. As a result, good observation or imaging becomes possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmologic apparatus, and more particularly, to an ophthalmic apparatus for imaging a fundus of a subject's eye.

[0002]

2. Description of the Related Art Conventionally, a fundus camera is known as a device for performing a fundus examination by illuminating a fundus and photographing or observing the area. The fundus camera mainly performs wide-angle photographing. In this manner, when a wide-angle illumination is performed, an illumination lamp for irradiating the fundus, an objective lens of light emitted from a strobe, a cornea of an eye to be examined, and the like are used. Flare is generated from the image, and there is a difficulty that the flare easily enters the shooting surface.

[0003]

Heretofore, in order to remove the flare, an illuminating optical system has a black spot, an objective lens has an aspherical surface, or an optical system having an objective lens having a special curve is used. I have been. The illumination optical system having such a black spot and an aspherical lens has a disadvantage that the cost is high.

Accordingly, the present invention has been made to solve such a problem, and an object of the present invention is to provide an ophthalmologic apparatus capable of removing flare with a simple configuration.

[0005]

According to the present invention, there is provided an ophthalmologic apparatus having an illumination optical system for illuminating a fundus of an eye to be examined and a photographing optical system for photographing the illuminated fundus. A configuration is adopted in which linear polarizing plates whose polarization directions are substantially orthogonal to each other are arranged in the illumination optical system and the photographing optical system, respectively, and flare is removed.

In such a configuration, linearly polarized light in a predetermined direction is projected on the fundus by the polarizing plate of the illumination optical system. The linearly polarized reflected light from the objective lens or the cornea or the crystalline lens of the eye to be examined is effectively cut by the orthogonal polarizing plate of the imaging optical system, and is not formed as a flare on the image plane. On the other hand, the linearly polarized light that has entered the fundus is irregularly reflected by the fundus, and the polarized light is also randomly polarized, so that it can pass through the polarizing plate of the photographing optical system, and a fundus image can be formed on the image plane.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. Hereinafter, the ophthalmologic apparatus will be described as an example of a fundus camera.

In FIG. 1, E denotes an eye to be inspected, 10 denotes an illumination optical system for illuminating the eye to be inspected, and a light source 11 and a mirror 1 are provided.
2. It comprises a lens 13, a mirror 14, a lens 15 and a linear polarizer 16. The light from the light source 11 is
Lens 13 and mirror 1 together with the light partially reflected by 2
4. The light enters the polarizing plate 16 through the lens 15 and is converted into linearly polarized light by the polarizing plate 16. The light beam from the polarizing plate is reflected by the perforated mirror 21 and illuminates the fundus of the eye E through the objective lens 20.

The reflected light from the fundus passes through the hole of the perforated mirror 21 through the objective lens 20 and forms an image on the image plane 40 by the photographing optical system 30 composed of the polarizing plate 31, lenses 32 and 33. Is done. As is well known, the fundus image formed on this image plane is observed by an examiner via an observation system 41 such as an optical finder, or a CCD.
An image is captured via an imaging system 42 such as a camera and displayed on a monitor or the like. In this case, the linear polarizing plate 31 of the imaging optical system is
The direction of the linearly polarized light is set so as to be substantially orthogonal to the direction of the linearly polarized light by the polarizing plate 16.

In such a configuration, when observing the fundus, the light source 11 is turned on. The light beam from the light source 11 is linearly polarized by the polarizing plate 16 of the illumination optical system 10, reflected by the perforated mirror 21, and reflected by the objective lens 20.
To illuminate the fundus of the eye E to be examined. The light reflected from the fundus passes through the hole of the perforated mirror 21 through the objective lens 20 and is imaged on the image plane 40 by the imaging optical system 30.
The fundus image formed on the image forming surface is observed through the observation system 41 or is displayed on a monitor or the like captured through the imaging system 42 and is similarly observed.

In this case, a part of the light emitted from the illumination optical system 10 is reflected by the objective lens 20 and the cornea and the crystalline lens of the eye E to be inspected, passes through the hole of the perforated mirror 21, and is formed by the photographing optical system 3.
It is led to 0. These lights are irrelevant to the fundus image and are unnecessary or obstructive rays for photographing, and are called so-called flare rays.

Conventionally, the flare is removed by using a black spot in the illumination optical system 10 to remove these flare, or by forming the objective lens surface into a specific curve to process the reflection from the objective lens 20. I've been.

On the other hand, in the embodiment shown in FIG. 1, reflected light from the cornea and the lens of the objective lens 20 and the eye E is
The direction of polarization is the same as the direction of linearly polarized light of the polarizing plate 16 of the illumination optical system 10.
The direction of the linearly polarized light 1 is selected so as to be substantially orthogonal to this direction, so that these harmful rays are
And the flare is not formed on the image plane 40.

On the other hand, the linearly polarized light incident on the fundus is irregularly reflected on the fundus and the polarized light is also random polarized light, so that it can pass through the perforated mirror 21 and the polarizing plate 31 in the photographing optical system. It becomes possible to form a fundus image. In this way, a good fundus image without flare is formed on the imaging surface 40, and good observation or imaging can be performed.

[0015]

As described above, according to the present invention, since the linearly polarizing plate whose polarization direction is substantially orthogonal to the illumination optical system and the photographing optical system is arranged, the straight line from the cornea or the lens of the objective lens or the eye to be examined can be obtained. The polarized light beam is effectively cut by the polarizing plate of the photographing optical system, and is not formed as a flare on the image forming surface. On the other hand, linearly polarized light incident on the fundus is irregularly reflected on the fundus and the polarized light is also random polarized light, so it can pass through the polarizing plate of the imaging optical system, enabling the formation of a fundus image without flare on the image plane. Thus, good observation or imaging can be performed.

[Brief description of the drawings]

FIG. 1 is an optical diagram showing an overall configuration of an ophthalmologic apparatus according to the present invention.

[Explanation of symbols]

 Reference Signs List 10 illumination optical system 16 polarizing plate 20 objective lens 21 perforated mirror 30 photographing optical system 31 polarizing plate 40 imaging surface

Claims (1)

[Claims] An illumination optical system for illuminating a fundus of an eye to be inspected;
An ophthalmologic apparatus including a photographing optical system for photographing the illuminated fundus, wherein a linear polarizer having a polarization direction substantially orthogonal to each of the illumination optical system and the photographing optical system is disposed to remove flare. Ophthalmic equipment.