JP2000271088A - Fundus photographic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve operability by enabling an inspector to carry out fundus photography while observing moving images with visible light by a display means. SOLUTION: The hemoglobin included in the blood reflects near IR light but absorbs the substantial part of the visible light and, therefore, an IR cut filter 4, which allows the transmission of much of the visible light and shuts off part of the near IR light and red light, is inserted into the apparatus, by which the contrast of the blood vessel of the fundus image E' is enhanced, focusing is facilitated and further the flare from the anterior segment of the eye having dependence on wavelengths is made easily visible to allow exact alignment. If the focusing is executed by the video of a black and white image pickup means 18, the focusing is not affected by a change in the inspector's diopter unlike from an optical finder and, therefore, the easy and exact focusing is made possible and the inspector is able to easily carry out fundus photography while viewing a television monitor 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fundus photographing apparatus used in ophthalmic hospitals and the like.

[0002]

2. Description of the Related Art Conventionally, in a fundus camera for photographing a fundus with visible light, the fundus photographing is performed by observing with an optical viewfinder and performing positioning and focusing.

[0003]

However, in the above-mentioned conventional example, the optical finder is inferior in operability, such as requiring skill, to focus on an aerial image, and because it is observed by a color imaging means, sufficient sensitivity is obtained. There is a problem that it cannot be obtained.

An object of the present invention is to solve the above-mentioned problems,
It is an object of the present invention to provide a fundus photographing apparatus in which operability is improved by enabling photographing of a fundus while observing a moving image with visible light by a display unit.

[0005]

According to the present invention, there is provided a fundus photographing apparatus according to the present invention, comprising: a black-and-white image pickup means for picking up an image of a fundus; a display means for displaying a moving picture image by the black-and-white image pickup means; It has a color image pickup means for picking up a color fundus image different from the image pickup means, and an infrared cut filter for blocking at least near-infrared light is provided detachably in the illumination optical path.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 is a configuration diagram of a fundus imaging apparatus according to a first embodiment, in which non-mydriatic imaging without using a mydriatic agent and mydriatic imaging using a mydriatic agent can be performed. On the illumination optical path O1 from the observation halogen lamp light source 1 to the objective lens 2 facing the eye E, as shown in FIG. 2, an infrared filter 3 having a spectral characteristic A for blocking visible light or blocking infrared rays. An infrared cut filter 4 having a spectral characteristic B, a lens 5, a strobe light source 6 for photographing, a small mirror 8, a lens 9, and a perforated mirror 10 for guiding focus light and retracting out of the optical path by a solenoid 7 at the time of photographing. The split light S is arranged on the fundus in the reflection direction of the small mirror 8.
Is arranged. The infrared filter 3 is formed integrally with the infrared cut filter 4, and when one is inserted into the optical path, the other is retracted from the optical path and inserted and removed alternately.

In the optical path O2 facing the eye E, an objective lens 2, a perforated mirror 10, a focus lens 12, an image forming lens 13, an optical path switching mirror 14, a relay lens 1
5. Color imaging means 16 are sequentially arranged. In addition, a relay lens 17 and a black-and-white imaging unit 18 having sensitivity to visible light and near-infrared light are arranged on the optical path O3 in the reflection direction of the switching mirror 14. The color imaging means 16 is connected via a frame memory 19, and the monochrome imaging means 18 is directly connected to a signal processing means 20. The output of the signal processing means 20 is connected to a television monitor 21.

At the time of observation, a light beam from the halogen lamp light source 1 passes through the infrared filter 3, the lenses 5 and 9, is reflected by the perforated mirror 10, and is projected on the fundus of the eye E through the objective lens 2. The reflected light from the fundus is
The light passes through the aperture of the perforated mirror 10, the focus lens 12, and the imaging lens 13, is reflected by the switching mirror 14, and forms an image on the monochrome imaging means 18 via the lens 17. The video fundus image E ′ captured by the monochrome image capturing means 18 is displayed on the television monitor 21 via the signal processing means 20.

In non-mydriatic photography, the infrared filter 3
Is inserted into the optical path O1 and does not transmit visible light. At the time of alignment, the small mirror 8 is inserted into the optical path by the solenoid 7 and the light beam from the focusing optical system 11 is
Then, infrared split light for focusing is projected on the fundus through the lens 9, the perforated mirror 10, and the objective lens 2. The reflected light from the fundus passes through the optical paths O2 and O3 similarly to the observation light flux, and forms an image on the monochrome image pickup means 18. The examiner looks at the split image S together with the fundus image E ′ picked up by the image pickup means 18, and moves the focus lens 12 to perform alignment so that the fundus image E ′ on the television monitor 21 is in focus. Note that the image signal may be calculated to detect the blur, and the focus lens 12 may be driven to perform automatic focusing.

In photographing, when the end of the alignment is detected and the solenoid 7 is driven, the small mirror 8 is moved to the optical path O1.
The switching mirror 14 jumps up, and the strobe light source 6 emits light. The infrared filter 3 is retracted and the infrared cut filter 4 is inserted, and the light beam from the strobe light source 6 is projected on the fundus through the optical path O1 like the observation light beam.
The light reflected from the fundus passes through the optical path O2, the fundus image E 'is captured by the color imaging means 16 via the relay lens 15 by the imaging lens 13, and stored in the frame memory 22. Switching from the moving image from the imaging unit 18 by the signal control unit 20, the photographed still image is displayed on the television monitor 21.

In the case of mydriatic photography, the infrared filter 3 goes out of the optical path O1 and the infrared cut filter 4 moves out of the optical path O1.
Get in. The fundus is illuminated with the visible light of the halogen lamp light source 1, alignment is performed based on the image captured by the black and white imaging unit 18, and imaging is performed by the color imaging unit 16 illuminated by the strobe light source 6.

Hemoclobin contained in blood reflects near-infrared light but absorbs a considerable portion of visible light, and therefore red that transmits much of visible light and blocks a part of near-infrared light and red light. By providing the outer cut filter 4, the contrast of blood vessels in the fundus oculi image E 'is increased, and focusing is facilitated. In addition, the flare from the anterior segment having wavelength dependency becomes easy to see, and positioning can be performed accurately. Further, when focusing is performed by the image of the black-and-white imaging means 18, unlike the optical viewfinder, it is not affected by a change in the diopter of the examiner, so that accurate focusing can be performed. It can be performed.

FIG. 3 is a block diagram of a fluorescent fundus camera according to a second embodiment, in which a strobe light source 6 and a mirror 9 in an illumination optical path O1 are shown.
In between, the excitation filter 30 for fluorescence imaging is disposed so as to be freely inserted and removed, and behind the perforated mirror 10 in the observation imaging optical path O2,
Similarly, a fluorescence photographing filter 31 is disposed so as to be freely inserted and removed. Other components are the same as those in FIG. 1, and members having the same functions are denoted by the same reference numerals.

At the time of photographing a color still image, the infrared cut filter 4 is inserted into the optical path O1, and a moving image photographed by the black-and-white photographing means 18 is observed on a television monitor 21. The mirror 14 is moved up and the image is taken by the color imaging means 16. The sensitivity of the black-and-white image pickup means 18 is sufficiently higher than that of the color image pickup means 16, so that the subject does not feel so dazzling even when illuminating with the halogen lamp light source 1 and observing a moving image. In the case of color moving image shooting, the color deteriorates. Therefore, the infrared cut filter 4 is detached from the optical path O1, the switching mirror 14 is raised, and the fundus illuminated by the halogen lamp light source 1 is imaged by the image pickup means 16, and a moving image is taken. The video is displayed on the monitor 21 and the video is video-recorded.

At the time of visible fluorescence imaging, the fluorescence excitation filter 3
0 is inserted into the optical path O1 and observed by the black-and-white image capturing means 18. At the time of photographing, the fluorescent filter 31 is inserted into the optical path O2, the strobe light source 6 emits light, and the image is captured by the image capturing means 16 or 18.

At the time of infrared fluorescence photographing excited by light having a wavelength of 700 to 800 nm, the infrared cut filter 4 is retracted from the optical path O1, the fluorescence excitation filter 30 is inserted and observed by the black-and-white image pickup means 18, and the photographing is performed by fluorescence filtration. The filter 31 is inserted, the strobe light source 6 emits light, and the image is photographed by the monochrome image pickup means 18.

In addition, as shown in FIG. 1, the infrared filter 3 is set so as to enter when the infrared cut filter 4 comes out.
Illumination via the infrared filter 3 may be performed, and color imaging or fluorescence imaging may be performed by observing with infrared light. At that time, the fluorescent filters 31 and 32 are inserted at the time of photographing.

[0018]

As described above, the fundus photographing apparatus according to the present invention has an infrared cut filter that blocks near-infrared light, which is detachably provided in the illumination optical path. Positioning can be performed, and fundus photography can be performed in a comfortable posture with a light amount that is not dazzling to the subject.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment.

FIG. 2 is a graph showing spectral characteristics of an infrared filter and an infrared cut filter.

FIG. 3 is a configuration diagram of a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Halogen lamp light source 3 Infrared filter 4 Infrared cut filter 6 Strobe light source 7 Solenoid 8 Small mirror 10 Perforated mirror 11 Focus optical system 14 Switching mirror 16 Color imaging means 18 Monochrome imaging means 19 Frame memory 20 Signal processing means 21 TV monitor 30 Fluorescence excitation filter 31 Fluorescence filtration filter

Claims (2)

[Claims] 1. A monochrome imaging means for imaging a fundus, a display means for displaying a moving image by the monochrome imaging means, and a color imaging means for imaging a color fundus image different from the monochrome imaging means. A fundus photographing apparatus characterized in that an infrared cut filter that blocks infrared light is detachably provided in an illumination optical path. 2. The fundus imaging apparatus according to claim 1, wherein the infrared cut filter displays a display that deviates from the optical path or deviates from the optical path when the infrared fluorescent filter is inserted.