JPH04253838A - Simultaneous stereoscopic fundus camera - Google Patents

Abstract

PURPOSE:To provide a simultaneous stereoscopic fundus camera by achieving an increase in amount of information necessary for analysis without significant enlargement of a construction even when a stereoscopic analysis is carried out by an image processing using a photoelectric image sensor for color. CONSTITUTION:A simultaneous stereoscopic fundus camera is provided with a fundus lighting system 10 to light the fundus R through an objective lens 23 and with a fundus simultaneous stereoscopic view optical system 11 to image the fundus R. The fundus simultaneous stereoscopic view optical system 11 has a pair of photoelectric type imaging optical systems 32A and 32B to form a fundus image corresponding to the fundus viewed from the left and an eyeground image corresponding to the fundus viewed from the right simultaneously in separate areas of an imaging surface 49a of one photoelectric type color image sensor 49. The photoelectric image sensor 49 is connected to one image processor 53.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention provides a method for simultaneously displaying a fundus image corresponding to the fundus viewed from the left side and a fundus image corresponding to the fundus viewed from the right side in separate regions of the imaging surface of a single color photoelectric image sensor. This invention relates to a simultaneous stereoscopic fundus camera.

0002

[Prior Art] Conventionally, a simultaneous stereoscopic fundus camera has a fundus simultaneous stereoscopic viewing optical system that uses a light beam that forms a fundus image corresponding to the fundus seen from the left side and a fundus image corresponding to the same fundus seen from the right side. A device is known that is provided with a pair of divided imaging optical systems that simultaneously guide the formed light beam onto the film and form an image. A quick return mirror is installed in front of the film in this pair of divided imaging optical systems, and during observation, this quick return mirror is inserted into the optical path of the fundus simultaneous stereoscopic vision optical system, and the left and right pair of finder optical systems are connected to each other. Through this system, a pair of fundus images can be viewed stereoscopically. In the conventional simultaneous stereoscopic fundus camera, a photoelectric photographing optical system is installed in the pair of divided imaging optical systems, and one fundus image is photographed by a monochrome TV camera serving as a photoelectric image sensor, and the fundus image is displayed on a TV monitor. It is designed to be displayed on the screen.

0003

[Problems to be Solved by the Invention] Nowadays, both of the pair of divided imaging optical systems are each provided with a photoelectric photographing optical system, and each photoelectric photographing optical system is provided with a monochrome TV camera. The output terminal of one TV camera is connected to one of two selected input terminals of an image processing device having a set of R, G, and B input terminals for color (for example, G
Connect the output terminal of the other TV camera to the other of the two selected input terminals of the image processing device (for example, the R(B) input terminal), and The light flux forming the corresponding fundus image is
The light flux that is guided to the V camera and forms a fundus image corresponding to the fundus seen from the right side is guided to the other TV camera to form fundus images on both TV cameras, and the output of this TV camera is transmitted to each R (B). , is input to the image processing device through the G input terminal, and the image processing device displays each fundus image as a 1/4 compressed image side by side on a TV monitor, and performs image processing using a photoelectric image sensor. It has been considered to perform stereoscopic analysis of fundus images.

[0004] However, when analyzing the unevenness of the optic disc, which is particularly important in stereoscopic analysis of fundus images through image processing using such a photoelectric image sensor, it is necessary to rely only on black-and-white gradation information in monochrome fundus images. Therefore, the amount of information necessary for analysis is insufficient, and it is difficult to determine the boundary between the optic disc and the retina.

[0005] Therefore, it may be possible to increase the amount of information required for analysis by providing a pair of photoelectric photographing optical systems with two color TV cameras to produce a color fundus image.

However, with such a configuration, each T
R for two sets of colors each corresponding to V camera
, G, , B input terminals must be provided, and there is a disadvantage that the structure of the simultaneous stereoscopic fundus camera including its image processing system becomes large.

The present invention has been made in view of the above circumstances, and its purpose is to significantly increase the size of the structure even when performing three-dimensional analysis by image processing using a color photoelectric image sensor. The object of the present invention is to provide a simultaneous stereoscopic fundus camera that can increase the amount of information required for analysis without compromising the amount of information required for analysis.

[0008]

[Means for Solving the Problems] In order to achieve the above object, a simultaneous stereoscopic fundus camera according to the present invention includes a fundus illumination system that illuminates the fundus through an objective lens, and a fundus illumination system that illuminates the fundus through the objective lens. In a simultaneous stereoscopic fundus camera equipped with a fundus simultaneous stereoscopic vision optical system, the fundus simultaneous stereoscopic vision optical system has a fundus image corresponding to the fundus seen from the left side and a fundus image corresponding to the fundus seen from the right side. It has a pair of photoelectric photographing optical systems that simultaneously form images on different areas of the imaging surface of one color photoelectric image sensor, and the photoelectric image sensor has a pair of color R, G, It is characterized in that it is connected to an image processing device having a B input terminal.

[0009]

[Function] According to the fundus camera according to the present invention, when the fundus is illuminated by the fundus illumination system, the fundus reflected light is guided to a pair of photoelectric photographing optical systems of the fundus simultaneous stereoscopic vision optical system, and the fundus is seen from the left side. A fundus image corresponding to the fundus image viewed from the right side and a fundus image corresponding to the fundus image viewed from the right side are simultaneously formed in separate areas of the imaging surface. Therefore, by displaying a pair of fundus images simultaneously formed in different areas of the imaging surface side by side on a TV monitor, it is possible to perform stereoscopic analysis using a color image with a larger amount of information than a monochrome image. Also,
Since the color image processing device has only one set of R, G, and B input terminals, it is possible to increase the amount of information without increasing the structure of the simultaneous stereoscopic fundus camera. According to the present invention, since a pair of fundus images are formed simultaneously when images are formed on the imaging surface of the photoelectric image sensor, the resolution is lower than when a single fundus image is formed on the imaging surface. However, conventionally, when analyzing the fundus of the eye, the images were compressed and displayed side by side, so three-dimensional analysis can be performed without reducing the resolution.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, 10 is a fundus illumination system, and 11 is a simultaneous stereoscopic viewing optical system. The fundus illumination system 10 includes an observation light source 1
2. It has a photographing light source 13. Observation light source 12 and photography light source 1
3 is conjugate with respect to the half mirror 14. A condenser lens 15 is provided between the observation light source 12 and the half mirror 14, and a condenser lens 16 is provided between the photographing light source 13 and the half mirror 14. A concave mirror 17 is provided on the optical axis of the condenser lens 16 on the opposite side of the condenser lens 16 with the photographing light source 13 in between.

Illumination light from observation light source 12, photographing light source 13
Illumination light is guided to a perforated mirror 22 via a half mirror 14, a light shielding plate 18, a relay lens 19, a reflecting mirror 20, and a relay lens 21. The perforated mirror 22 is shown in Figure 3.
It has a hole 22a as shown in FIG. The illumination light is reflected by the perforated mirror 22 toward the objective lens 23,
It passes through the cornea C and crystalline lens 4 of the eye E to be examined, and illuminates the fundus R. As shown in FIG. 4, the light shielding plate 18 has a light shielding area 18a at the center and a transmitting area 18b at the periphery, which will be described later.

As shown in FIG. 2, the fundus simultaneous stereoscopic viewing optical system 11 has a two-hole aperture 24, a Porro prism 25 for erecting an image which also serves as a beam splitter, and a pair of imaging optical systems 26 and 27. The two-hole diaphragm 24 has a pair of circular openings 24 as shown in FIG.
a, 24b. This pair of circular openings 24a, 24
b is symmetrical with respect to the optical axis N of the objective lens 23 in the left-right direction of the eye E to be examined. The two-hole diaphragm 24 is provided on the opposite side of the objective lens 23 with the perforated mirror 22 as a boundary. The light beam P reflected by the fundus R passes through the crystalline lens 4, the objective lens 23, and the hole 22a of the perforated mirror 22, and then passes through the two-hole diaphragm 2.
4. The circular opening 2 of this two-hole diaphragm 24
4a and 24b, respectively. The circular opening 24a
The circular aperture 24b plays a role of passing a light flux forming a fundus image corresponding to the fundus viewed from the left side, and the circular aperture 24b plays a role of passing a light flux forming a fundus image corresponding to the fundus viewed from the right side.

[0013] The Porro prism 25 is disposed in front in the direction of passage of the light beam P that has passed through the circular apertures 24a, 24b of the two-hole diaphragm 24. Here, the light-shielding plate 18 is arranged at a position conjugate with the pupil of the eye E, and the reflected image of the light-shielding region 18a on the cornea C covers the pair of circular apertures 24a and 24b at the position of the two-hole diaphragm 24. has been made into
The light shielding plate 18 serves to prevent the passage of reflected illumination light that is harmful to the cornea C when photographing.

The pair of divided imaging optical systems 26 and 27 have focusing lenses 28 and 29 and imaging lens systems 30 and 31. The imaging lens systems 30 and 31 here include lenses 30a and 3
0b, 31a, 31b, quick return mirror 32,
It has 33. Quick return mirrors 32 and 33 are provided between lenses 30a and 31a and lenses 31b and 31b. This quick return mirror 32, 33
has a function of guiding the divided luminous flux to a pair of photoelectric photographing optical systems 32A and 32B. Note that the photoelectric imaging systems 32A and 32B
The structure and operation of will be described later.

The divided light beams that have passed through the quick return mirrors 32 and 33 are guided to reflecting prisms 35 and 36 via lenses 30b and 31b. The reflecting prism 35, 3
A half mirror 37 is provided in front of the mirror 6 in the reflection direction. The observation system 3 is located in front of the half mirror 37 in the direction of reflection.
8, and the front in the transmission direction is a film photographing system 39. The observation system 38 includes a reflector 40 and an eyepiece 41
has. As a result, fundus images are simultaneously observed stereoscopically. The film photographing system 39 has a film 42. As a result, a fundus image corresponding to the fundus R viewed from the left side and a fundus image corresponding to the fundus R viewed from the right side are simultaneously formed in separate areas on both the left and right sides of the film 42.

The pair of photoelectric photographing optical systems 32A and 32B are comprised of quick return mirrors 32 and 33, relay lenses 43 and 44, and reflecting prisms 45 and 46, as shown in FIG. The pair of photoelectric photographing optical systems 32A, 3
2B, an aperture mask 47 is provided at a position optically conjugate with the film 42 with respect to the quick return mirrors 32 and 33. This opening mask 47 has rectangular openings 47a and 47b as shown in FIG. The fundus image forming light flux guided via one photoelectric photographing optical system 32A and the fundus image forming light flux guided via the other photoelectric photographing optical system 32B are once imaged at this aperture mask position. The fundus image forming light beam guided through one photoelectric photographing optical system 32A passes through the aperture 47a and is guided to the filter 51. The fundus image forming light beam guided via the other photoelectric photographing optical system 32B passes through the aperture 47b and is guided to the filter 51. A plurality of types of filters 51 are prepared and are selectively inserted into the optical path of a pair of photoelectric photographing optical systems 32A and 32B according to the optical characteristics of the photoelectric image sensor, which will be described later. Although it is automatically inserted here in conjunction, it may also be inserted manually. The fundus image forming light flux that has passed through the filter 51 is reflected by the reflection mirror 4.
8 leads to an imaging lens which will be described later.

The pair of photoelectric photographing optical systems 32A and 32B are connected to one color photoelectric image sensor (for example, a color TV).
camera) 49. A plurality of types of photoelectric image pickup devices 49 are prepared, and for example, one having sensitivity in the visible region and one having sensitivity in the infrared region are used. color aperture mask 4
An imaging lens 52 is provided between the photoelectric imaging device 7 and the photoelectric imaging device 49, and the aperture mask 47 and the imaging surface 49a of the photoelectric imaging device 49 are optically conjugate with respect to the imaging lens 52. As shown in FIG. 8, the imaging surface 49a has rectangular contours 47c and 47d corresponding to the apertures 47a and 47b of the aperture mask 47.
is formed. The fundus image forming light beam guided via one photoelectric photographing optical system 32A passes through an aperture 47a, for example, and is imaged within a rectangular outline 47c of an imaging surface 49a, and passes through the other photoelectric photographing optical system 32b. For example, the fundus image forming light flux guided by
imaged simultaneously within the Therefore, on the imaging surface 49a, a fundus image R' corresponding to the fundus viewed from the left side and a fundus image R' corresponding to the fundus viewed from the right side are simultaneously formed in separate areas.

The photoelectric image sensor 49 has R, G, and B output terminals, and the R, G, and B output terminals are connected to the R, G, and B input terminals of one color image processing device 53. ing. The R, G, and B signals as the photoelectric output of the photoelectric image sensor 49 are input to the image processing device 53, which assembles the photoelectric output into a video signal and outputs it to the TV monitor 54. Two stereoscopic fundus images R' and R' are displayed in color on the TV monitor 54, either separately or simultaneously.

[0019] With the fundus images displayed simultaneously and superimposed, it is possible to three-dimensionally analyze the fundus image using color information, which has a richer amount of information than monochrome.

[0020]

[Effect] Since the simultaneous stereoscopic fundus camera according to the present invention is configured as described above, the structure can be significantly enlarged even when performing stereoscopic analysis by image processing using a color photoelectric image sensor. This has the effect of increasing the amount of information required for analysis without any problems.

[Brief explanation of the drawing]

FIG. 1 is a front view of an optical system of a simultaneous stereoscopic fundus camera according to the present invention.

FIG. 2 is an optical diagram of the optical system viewed from the direction of arrow X in FIG. 1;

FIG. 3 is a plan view of the perforated mirror of FIG. 1;

FIG. 4 is a plan view of the light shielding plate in FIG. 1;

FIG. 5 is a plan view of the two-hole aperture shown in FIG. 1;

6 is an optical diagram of a pair of photoelectric photographing optical systems viewed from the direction of arrow Y in FIG. 1; FIG.

FIG. 7 is a plan view of the aperture mask shown in FIG. 1;

8 is an explanatory diagram of a fundus image formed on the imaging surface of FIG. 1. FIG.

[Explanation of symbols]

10 Fundus illumination system 11 Simultaneous stereoscopic vision optical system 23 Objective lenses 32A, 32B Pair of photoelectric imaging optical systems 47 Aperture diaphragm 49 Photoelectric imaging device 49a Imaging surface 51 Filter 53 Image processing device R Fundus

Claims (3)

[Claims] 1. A simultaneous stereoscopic fundus camera comprising: a fundus illumination system that illuminates the fundus through an objective lens; and a fundus simultaneous stereoscopic vision optical system that images the fundus through the objective lens; The stereoscopic optical system includes a pair of optical systems that simultaneously form a fundus image corresponding to the fundus seen from the left side and a fundus image corresponding to the fundus seen from the right side in different regions of the imaging surface of one color photoelectric image sensor. A simultaneous stereoscopic fundus camera comprising a photoelectric imaging optical system, wherein the photoelectric imaging device is connected to an image processing device having a set of R, G, and B input terminals. 2. A plurality of types of the photoelectric imaging devices are prepared, a filter corresponding to the characteristics of each of the photoelectric imaging devices is prepared in the pair of photoelectric imaging optical systems, and the pair of photoelectric imaging optical systems 2. The simultaneous stereoscopic fundus camera according to claim 1, wherein a filter corresponding to a photoelectric imaging device set in the photoelectric imaging optical system is selectively inserted into the optical path of the camera. 3. The pair of photoelectric photographing optical systems includes an imaging lens for a photoelectric imaging device, and the photoelectric photographing optical system includes a lens that is optically conjugate with the imaging surface with respect to the imaging lens. 2. The simultaneous stereoscopic fundus camera according to claim 1, further comprising an aperture mask having respective apertures at positions through which respective light beams forming the two fundus images are transmitted.