JP3073510B2 - Ophthalmic imaging equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention has a television image receiving system that guides a light beam from an eye to be inspected to an image pickup device via a television relay lens, and performs infrared fluorescence imaging. The present invention relates to an improvement in an ophthalmologic imaging apparatus capable of performing imaging other than infrared fluorescence imaging.

(Prior Art) Conventionally, a light flux from an eye to be examined, for example, a fundus, is imaged through an imaging device (for example, a relay lens for television).
2. Description of the Related Art An ophthalmologic photographing apparatus that has a television image receiving system that guides an image to a receiving surface of a CCD camera and that can perform visible light imaging (for example, visible color imaging and visible fluorescence imaging) is known.

Recently, an ophthalmologic imaging apparatus capable of performing infrared fluorescence imaging in addition to visible fluorescence imaging has been proposed.

(Problems to be Solved by the Invention) In the fluorescence imaging, the amount of light received on the image receiving surface based on the luminance of the excitation light from the fundus changes as time elapses from the time of the initial imaging in FIG. In particular, the luminance of the excitation light from the fundus during infrared fluorescence imaging is lower than the luminance of the excitation light from the fundus during imaging other than infrared fluorescence imaging. For this reason, the amount of light received by each light receiving element on the image receiving surface decreases, and the amount of light becomes insufficient. Therefore, the photoelectric conversion output becomes smaller than that in the case of photographing other than the infrared fluorescent photographing. When the image is displayed on a television screen, the contrast or the like becomes low, and the fundus image may be deteriorated.

Therefore, an object of the present invention is to provide an ophthalmologic imaging apparatus capable of obtaining a good eye image of an examinee even when performing infrared fluorescent imaging in which the luminance of excitation light is particularly low.

(Means for Achieving the Object) In the ophthalmologic imaging apparatus according to claim 1 of the present invention, in order to achieve the above object, the imaging area of the image sensor on the image receiving surface during infrared fluorescence imaging is reduced. It is configured to be smaller than the imaging area at the time other than the infrared fluorescence imaging.

4. The ophthalmologic photographing apparatus according to claim 3, wherein the eye image to be inspected on the television screen is enlarged in accordance with a change in a direction in which the imaging area of the image sensor on the image receiving surface decreases. It is characterized by having an enlarging means.

(Operation) According to the ophthalmologic imaging apparatus according to claim 1 of the present invention, when the amount of light received on the image receiving surface of the image sensor decreases in the infrared fluorescent imaging mode, the imaging area on the image receiving surface is reduced. It can be made smaller than the imaging area at the time of imaging other than infrared fluorescence imaging. Therefore, even when the light flux from the eye to be inspected is insufficient, a bright image of the eye to be inspected can be formed on the image receiving surface of the image sensor. On the other hand, in cases other than infrared fluorescence imaging, the imaging area on the image receiving surface of the image sensor can be made larger than that in infrared fluorescence imaging. Therefore, when the luminous flux from the eye to be inspected is sufficient, the image of the eye to be inspected can be received in a wide range of the image receiving surface of the image sensor, and deterioration in resolution can be prevented.

According to this configuration, since the image is received within a narrow range of the image receiving surface of the image sensor, the state of the eye image to be inspected is changed from a large displayed state to a small displayed state, and the inspection is performed. However, in the ophthalmologic photographing apparatus according to claim 3, the examinee's eye image enlarging means enlarges the examinee's eye image corresponding to the reduction of the imaging area and displays the image on the television screen. , The discomfort due to the change in the scale of the eye image to be examined can be eliminated.

(Embodiment) Hereinafter, an embodiment of an ophthalmologic photographing apparatus according to the present invention will be described with reference to the drawings.

In FIG. 1, 1 is an illumination optical system, and 2 is a photographing optical system. The illumination optical system 1 generally includes a halogen lamp 3 as an observation light source, a condenser lens 4, a xenon tube 5, a condenser lens 6, a ring-shaped aperture 7, a relay lens 8, a mirror 9, and a relay lens 10 as an imaging light source.

The photographing optical system 2 includes an objective lens 11, a perforated mirror 12, a focusing lens 13, an imaging lens 14, a quick return mirror 15,
16, consisting of film 17. The objective lens 11 faces the subject's eye 18. The ring-shaped aperture 7 is provided at a position substantially conjugate with the pupil 19 of the eye 18 with respect to the relay lenses 8 and 10 and the objective lens 11.

At the time of observation, illumination light of the halogen lamp 3 emits condenser lenses 4 and 6, a ring-shaped aperture 7, a relay lens 8, a mirror 9, a relay lens 10, a perforated mirror 12, and an objective lens.
It is guided to the eye to be examined 18 through 11 and illuminates the fundus 20 of the eye to be examined 18. The illumination light becomes ring-shaped illumination light when passing through the pupil 19 of the subject's eye 18. At the time of photographing the subject's eye, the xenon tube 5 emits light by operating a photographing switch (not shown), and the fundus 20 is similarly illuminated.

The luminous flux from the fundus 20 is guided to the perforated mirror 12 through the objective lens 11, and is transmitted through the hole 12 a of the perforated mirror 12, the focusing lens 13, and the imaging lens 14 to the quick return mirror 15.
Leads to. Here, the quick return mirror 15 is retracted from the optical path of the imaging optical system 2 during visible light observation imaging, and inserted into the optical path of the imaging optical system 2 during infrared fluorescence observation imaging. The quick return mirror 15 forms a part of the television image receiving system 21, and the television image receiving system 21 will be described later.

The quick return mirror 16 is inserted into the optical path of the photographing optical system 2 during observation during visible light photographing, and the light flux from the fundus 20 is reflected by the quick return mirror 16, and the mirror 23 of the eyepiece optical system 22 and the eyepiece 24 through the examiner's eye
Enter 25. As a result, the fundus 20 of the subject's eye 18 is observed.

A visible fluorescent exciter filter 26 and an infrared fluorescent exciter filter 27 can be inserted into the optical path between the mirror 9 and the relay lens 8 of the illumination optical system 1. In addition, a barrier filter 28 for visible fluorescence and a barrier filter 29 for infrared fluorescence can be inserted between the perforated mirror 12 of the photographing optical system 2 and the focusing lens 13.

At the time of visible color photographing, the visible fluorescent exciter filter 26 and the infrared fluorescent exciter filter 27 are retracted from the optical path of the illumination optical system 1, and the visible fluorescent barrier filter 28 and the infrared fluorescent barrier filter 29 are Has been evacuated from the light path. At the time of visible fluorescent imaging, the visible fluorescent exciter filter 26 is used for the illumination optical system 1.
Is inserted in the optical path. Similarly, a visible fluorescence barrier filter 28 is inserted into the optical path of the imaging optical system 2. At the time of infrared fluorescent imaging (wavelength 800 nm to 950 nm), an infrared fluorescent exciter filter 27 is inserted into the optical path of the illumination optical system 1. Similarly, a visible fluorescence barrier filter 29 is inserted into the optical path of the imaging optical system 2.

The television receiving system 21 includes a deflecting mirror 30, a television relay lens 31, and a CCD camera 32 as an image sensor.
Is provided. Television relay lens 31 is 2
Are prepared individually. On the other hand, a television relay lens (a lens for a half inch) 31a has an image formation area on the image receiving surface 36 of the CCD camera 32 during infrared fluorescent imaging other than infrared fluorescent imaging. With a relay magnification that is smaller than The other television relay lens (two-thirds)
Lens for inch) 31b is a CCD other than infrared fluorescent photography
The relay magnification is such that the imaging area on the image receiving surface of the camera 32 is larger than the imaging area for infrared fluorescence imaging. The two television relay lenses 31a and 31b are alternatively inserted into the optical path of the television image receiving system 21.

Here, the television relay lenses 31a and 31b are switched by the drive circuit 33. The drive circuit 33 is
When an infrared fluorescent imaging mode signal is input from a mode designation circuit (not shown), the television relay lens 31b is retracted from the optical path of the television image receiving system 21, and the television relay lens 31a is moved to the television image receiving system 21. In the optical path.

The photoelectric conversion output of the CCD camera 32 is input to a processing circuit 35. The processing circuit 35 outputs a video signal based on the photoelectric conversion signal, and also functions as a function of recording and reproducing an eye image to be inspected and a function of enlarging an eye image to be inspected. The details of the function of the eye image enlarging means will be described later. The video signal is input to the television monitor 37.

When a photographing switch (not shown) is operated during visible color photography or visible fluorescence photography, the xenon tube 5 emits light,
Quick return mirror 16 at the same time that the fundus 20 is illuminated
Is retracted from the optical path of the photographing optical system 2 and the light flux from the fundus 20 is guided to the film 17 to perform film recording. When the quick return mirror 15 is inserted, electronic video recording is performed, and the television relay lens 31 is used.
As shown in FIG. 2, substantially the entire area of the image receiving surface 36 (the entire area inside the broken line) is used as the image forming surface based on b. In FIG. 2, reference numeral 38 denotes a fundus image, and the fundus image 38 is displayed on a screen of a television monitor 37.

In the infrared fluorescent photographing mode, the television relay lens 31a is inserted into the optical path of the television image receiving system 21, so that as shown in FIG. ) Is used as an image plane. Therefore, during infrared fluorescent imaging, the light beam from the fundus 20 is received by a light receiving element that is approximately half of the image receiving surface 36, and the light beam from the fundus 20 is focused on a narrow area of the image receiving surface 36 to form an image. Therefore, even if the luminous flux from the fundus 20 is insufficient, it is possible to obtain a photoelectric conversion output large enough for image processing. Therefore, it is possible to prevent image deterioration due to a decrease in contrast or the like. On the other hand, the signal processing circuit 35 controls the fundus image 38 so that the subject's eye image magnifying means based on the infrared fluorescent imaging mode signal increases the fundus image 38 on the television screen.
To enlarge. As a result, as shown in FIG. 3, even when the fundus image 38 is reduced and formed on the image receiving surface 36, the size of the screen of the television monitor 37 is the same as the original size before the reduction. Can be displayed.

As described above, in the embodiment, the television relay lenses 31a and 31b are switched based on the infrared fluorescent imaging mode signal. However, either button operation or manual switching may be performed. When the button operation or manual switching is performed, the television relay lens 31b may be switched to the television relay lens 31a when the fundus image 38 on the screen of the television monitor 37 becomes difficult to see.

(Effect of the Invention) Since the ophthalmologic imaging apparatus according to the present invention is configured as described above, it is possible to obtain a good image of the eye to be inspected even when performing infrared fluorescent imaging in which the luminance of the excitation light is particularly low. To play.

[Brief description of the drawings]

FIG. 1 is an optical diagram showing the entire configuration of an embodiment of an ophthalmologic photographing apparatus according to the present invention, and FIGS. 2 and 3 are views for explaining an image forming plane on an image receiving surface of the CCD camera shown in FIG. FIG. 4 is a graph showing the relationship between the amount of light received on the image receiving surface of the CCD camera and time. 18 Eye 21 to be examined 21 Television image receiving system 31 Television relay lens 32 CCD camera (image sensor) 36 Image receiving surface

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61B 3/14

Claims (3)

(57) [Claims] An ophthalmologic photographing system having a television image receiving system for guiding a light beam from an eye to be examined to an image pickup device via a television relay lens, and capable of performing infrared fluorescence photography and photography other than infrared fluorescence photography. An ophthalmologic imaging apparatus, wherein the imaging area of the image sensor on the image receiving surface during infrared fluorescence imaging is configured to be smaller than the imaging area during non-infrared fluorescence imaging. . 2. An ophthalmologic photographing system having a television image receiving system for guiding a light beam from an eye to be examined to an image pickup device via a television relay lens, and capable of performing infrared fluorescent photographing and photographing other than infrared fluorescent photographing. In the apparatus, at least two television relay lenses are prepared, and one of the television relay lenses has an imaging area on an image receiving surface of the imaging device other than the infrared fluorescent imaging when performing infrared fluorescent imaging. The other relay lens for television has an imaging area on the image receiving surface of the image pickup element other than the infrared fluorescent imaging when the infrared fluorescent imaging is performed. An ophthalmologic photographing apparatus, having a relay magnification larger than an image area, wherein the two television relay lenses are alternatively inserted into an optical path of the television image receiving system. 3. An eye image enlarging means for enlarging an eye image on a television screen in accordance with a change in a direction in which an image forming area on the image receiving surface of the image sensor becomes smaller. The ophthalmologic photographing apparatus according to claim 1.