JP2860592B2 - Fundus camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a fundus camera provided with an observation and photographing system for observing and photographing the fundus of an eye to be inspected, and a focus detection system for detecting a focus state. Regarding improvement.

(Prior Art) As a conventional fundus camera, a focusing light beam is irradiated to an eye to be examined through a mirror obliquely arranged in an observation and photographing system for observing and photographing, and a focus state of the eye to be examined is detected. I was

(Problems to be solved by the present invention) However, in a conventional fundus camera, a mirror or the like provided to match the optical axis of the focusing light beam with the optical axis of the observation and photographing system in front of the eye to be examined. Due to the existence of the optical member, the distance from the eye to be examined to the film surface or the examiner to be observed becomes longer, the entire fundus camera becomes large, and occupies a considerable amount of space when placed in a treatment room such as a hospital. A problem had arisen.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and it has been proposed to observe and photograph a mirror for aligning an optical axis of a focusing light beam with an optical axis of an observation and imaging system in front of an eye to be examined. The lens is substantially integrated with a perforated mirror for reflecting the light source light beam, and the optical axis of the focusing light beam and the optical axis of the light source light beam for observation and photographing substantially coincide with each other, so that the fundus is compact as a whole. The purpose is to provide a camera.

(Constitution of the Invention) The present invention provides an illumination system for illuminating the fundus of the eye to be examined with light in a first wavelength range through a perforated mirror, and a reflected light from the fundus of the eye illuminated by the illumination system. An observation and photographing system for observing and photographing the formed fundus image through the hole of the perforated mirror; and a light for focusing on the fundus of the eye to be examined by light of a second wavelength range different from the first wavelength range. A fundus camera having a focus detection system for projecting an index light beam and receiving reflected light of the projected index light beam to detect a focus state, wherein the first wavelength band is provided in a hole of the perforated mirror; An optical member that transmits the light of the second wavelength range and reflects the light of the second wavelength range, the focus detection system projects the index light beam to the fundus through a wavelength division reflector, and reflects the reflected light from the fundus to the wavelength. It is configured so that it can receive light through a split reflector. A fundus camera according to claim.

(Function) According to the present invention, the observation and imaging light source light beam and the focusing light beam are incident on the perforated mirror coaxially, and the focusing light beam reflected by the fundus of the eye to be examined is substantially converted into the perforated mirror. And taken out coaxially with the optical axis of the light source for observation and photographing.

〔Example〕

Hereinafter, a mydriatic fundus camera which is an embodiment of the present invention will be described with reference to the drawings.

The mydriatic retinal camera of the embodiment, as shown in FIG.
It comprises an illumination system A, an observation and photography system B, a focus detection system C and a display system D.

The illumination system A illuminates the fundus oculi Eb of the eye E to be examined. The illumination system A reflector 1 is disposed in this order on the optical axis O _1, observation light source 2 such as a halogen lamp, a condenser lens 3, the photographing light source 4 such as a xenon lamp, a condenser lens 5, and a diaphragm ring opening 6, long pass filter 7, the optical axis O ₁ and oblique optical axis O ₂ relay lens 8 disposed in this order on the relay lens 9, and apertured mirror 10 having an aperture, the optical axis O ₂ and oblique It is disposed on the optical axis O ₃ consisting objective lens 11 opposed to the eye to be examined E.

The long-pass filter 7 applies λ ₁ (visible light) to light traveling along the optical axis O ₁ as shown in FIG.
It has the characteristics of reflection and transmission of λ ₂ (infrared light). Further, the hole of the perforated mirror 10, has the same reflecting surface and a peripheral portion in which the reflective surface except the hole portion of the apertured mirror 10, as shown in FIG. 3, lambda _{1 (visible} light) transmittance, A dichroic mirror 10a having the characteristic of λ ₂ (infrared light) reflection is arranged.

The ring-shaped aperture stop 6 uniformly illuminated by the observation light source 2 and the photographing light source 4 is provided with a perforated mirror 10 with respect to an optical system including a reflecting mirror 7 and relay lenses 8 and 9.
Has a conjugate relationship with The perforated mirror 10 has a conjugate relationship with the anterior segment Ep of the eye E with respect to the objective lens 11. Therefore, the link-shaped aperture stop 6 and the anterior segment Ep of the eye E to be examined
And have an optically conjugate relationship.

Observation and photographing system B observed and photographed fundus Eb is the objective lens 11 are disposed in this order on the optical axis O _3, a focusing lens 1
3, including an imaging lens 12 and a flip-up mirror 14. Observation unit, in addition to the above flip-up mirror 14 is in a state which is not thrown up, field lens 15 disposed in sequence on the reflection optical axis O ₄ of the flip-up mirror 14, the reflecting prism 16, and the examiner P It has an opposing eyepiece 17. The shooting unit
Objective lens 11 are disposed in this order on the optical axis O _3, consists of a focusing lens 13, an imaging lens 12, the flip-up mirror 14 is in the splashed state, and the film 18.

The focus detection system C includes a focusing infrared light source 50 on the optical axis O ₆ , a condenser lens 52 arranged such that the infrared light source 50 is at the front focal point, an index mask 56 with a deflection prism 54, lens
58, the mirror 60, the two-aperture stop 62 on the reflecting optical axis O ₇ of the mirror 60,
And an infrared half mirror 64. The index mask 56
Regarding the lens 58, the relay lenses 8, 9 and the objective lens 11,
It is conjugate with the fundus of the eye to be examined. The two-hole stop 62 is conjugate to the anterior segment Ep of the subject's eye with respect to the relay lenses 8 and 9 and the objective lens 11. The optical axis O ₇ coincides with O ₂ after passing through the long-pass filter 7.

As shown in FIG. 4, the deflection prism 54 is formed by attaching a pair of wedge-shaped prisms 68 and 69 to the index mask 56 with the optical axis O ₆ as a point of symmetry. In the index mask 56, as shown in FIG.
Vertical slits 70 around the optical axis O ₆ is provided. Two-aperture stop 62, as shown in FIG. 5, a pair of circular-hole aperture 74 which is formed around the optical axis O ₆ is separated symmetrically in the horizontal direction is provided.

Focus detection system C is further on the reflection optical axis O ₈ of the infrared light half mirror 64, are disposed a lens 80 and detector 82.
The detector 82 is conjugated to the fundus Eb of the subject's eye with respect to the lens 80, the relay lenses 8, 9 and the objective lens 11.

Display system D is in-focus state, provided for the purpose of displaying on the image capturing conditions and the like presented to the examiner also film 18, the optical axis O ₃
The display half mirror 31 disposed between the focusing lens 13 and the imaging lens 12 above, and the reflection optical axis O ₅ of the display half mirror 31
Mirror 32, relay lens 33, and indicator placed above
Consists of 34.

The display surface i of the display 34 is
It has a conjugate relationship with the film 18. The display half mirror 31 is a half mirror related to visible light, for example,
It reflects 50% of the incident light beam and transmits 50%.

Next, the operation of the fundus camera configured as described above will be described. The index mask 56 is illuminated with a substantially parallel light beam by the infrared light source 50 and the condenser lens 52. The infrared focused light beam emitted from the index mask 56 is converted into a lens 58 and a two-hole aperture.
62, infrared half mirror 64, long pass filter 64,
The light reaches the fundus Eb of the subject's eye via the relay lenses 8 and 9, the periphery of the perforated mirror 10, and the objective lens 11.

At the time of focusing, the infrared focused light flux emitted from the index mask 56 is incident from an off-axis symmetric position about the optical axis O ₃ of the anterior segment Ep of the subject's eye due to the action of the deflection prism 54 and the two-hole aperture. Then, a coincident point image is formed at the fundus Eb of the subject's eye, and when out of focus, the infrared focused light beam is separated at the fundus Eb of the subject's eye 2
Form a point image.

The reflected luminous flux of the infrared focused luminous flux at the fundus Eb of the subject's eye is converted into an objective lens 11, a dichroic mirror 10a, relay lenses 9, 8, a long-pass filter 64, and an infrared half mirror.
The light reaches the detector 82 via the lens 64 and the lens 80, and forms an image of the focused infrared light beam on the fundus Eb of the subject's eye again on the detector 82. The detector 82 detects an image formation state in the fundus oculi Eb of the eye to be inspected, that is, a state of coincidence or separation of two infrared light focused light beams. The output of the detector 82 is input to the display 34.

The illumination of the fundus oculi Eb of the subject's eye is performed by turning on the observation light source 2 and arranging the flip-up mirror 14 at the solid line position in FIG. 1 during observation. The observation visible light beam emitted from the observation light source 2 passes through a condenser lens 3, a condenser lens 5, a ring-shaped aperture stop 6, a long-pass filter 7, relay lenses 8, 9, a peripheral portion of a perforated mirror 10, and an objective lens 11. The eye fundus Eb is illuminated through the eye. The visible light beam for observation is
By the action of the ring-shaped aperture stop 6, the light passes through the periphery of the anterior segment Ep of the subject's eye and reaches the fundus oculi Eb of the subject's eye.

At the time of imaging, the imaging light source 4 is turned on to illuminate the fundus Eb of the subject's eye in the same manner as during observation.

Observation of the fundus oculi Eb of the eye to be examined is based on the fact that the light beam reflected by the fundus Eb of the eye to be examined is focused on the central part of the anterior segment Ep of the eye to be examined, the objective lens 11, the dichroic mirror 10a (pass), the focusing lens 13, the half mirror 31, through an image lens 12, further flip-up mirror 14 on the optical axis O _3, a field lens 15, the reflecting prism 16,
This is performed by the examiner P via the eyepiece 17.

Imaging of the fundus Eb is the flip-up mirror 14 is made thrown up from the optical axis O _3.

At the time of the observation and photographing, the display indicating the in-focus state, the photographing condition, and the subject information displayed on the display device 34 are displayed so as to be superimposed on the fundus image of the eye to be examined.

(Effect of the Invention) According to the present invention, the focusing light beam enters the observation and photographing system along the same optical axis as the illumination light beam, and the fundus of the eye to be inspected.
Since the focusing light beam reflected by Eb is extracted from the observation and imaging system along the same optical axis as the illumination light beam, the observation and imaging system does not require any special space for focusing, and the fundus This has the advantage that the camera as a whole can be made compact.

[Brief description of the drawings]

FIG. 1 is an optical diagram of a fundus camera according to an embodiment of the present invention, FIG. 2 is a graph of spectral characteristics of a long-pass filter, FIG. 3 is a graph of spectral characteristics of a dichroic mirror, FIG. FIG. 5 is a plan view of a two-hole aperture. A: Illumination system B: Observation and photography system C: Focus detection system D: Display system E: Eye to be examined 2 ... Light source for observation 4 ... Light source for photography 6 ... Ring aperture stop 7 ... … Long-pass filter 10… Perforated mirror 10a… Dichroic mirror 11… Objective lens 50… Infrared light source 54… Deflection prism 56 …… Index mask 62… Two aperture stop 64… Infrared light half Mirror 70 …… Slit

Claims (2)

(57) [Claims] An illumination system for illuminating a fundus of a subject's eye with light in a first wavelength range through a perforated mirror, and a fundus formed by reflected light from the fundus of the subject's eye illuminated by the illumination system An observation and photographing system for observing and photographing an image through the hole of the perforated mirror, and projecting a target light beam for focusing on the fundus of the eye to be examined with light of a second wavelength range different from the first wavelength range. A fundus camera having a focus detection system for receiving the reflected light of the projected index light beam and detecting a focus state, wherein the light of the first wavelength band is transmitted through the hole of the perforated mirror. A wavelength division reflecting mirror for reflecting light in a second wavelength range; the focus detection system projects an index light beam onto the fundus via the wavelength division reflecting mirror; Configuration that can receive light through a reflector Fundus camera and features. 2. The fundus camera according to claim 1, wherein the light in the first wavelength range is visible light, and the light in the second wavelength range is infrared light.