JPH1075932A - Eyeground photographing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically and easily photograph two eyeground images while changing a viewpoint in one shot without necessity to photograph an eyebottom twice while setting a camera at positions having the parallax in order to provide the three- dimensional observed image of the eyebottom and also without reducing the view while keeping exposure equal as well. SOLUTION: The light of an illumination lamp 11 is passed through a visible light cut filter 13, and the eyeground-is irradiated with infrared light from an objective lens 5 of an eyeground photographing optical system. On an optical axis 4 of the eyeground photographing optical system, a photographic iris 20 is provided so as to divide a pupil diameter into two at positions conjugate with a pupil in respect to the objective lens 5 and to be switched by a photographic iris switching means 21. After an eye to be examined is aligned/focused by the infrared light, a stroboscope 14 is emitted corresponding to a first photographic position detecting signal by scanning the photographic iris 20, the 1st image (right half, for example,) is photographed and recorded by a color television camera 20, continuously, the 2nd image (left half, for example,) is photographed and recorded at the next photographic position, and these images are displayed for stereoscopic observation on a monitor 35 (alternately side by side for liquid crystal spectacles, for example).

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 for photographing a fundus retina of an eyeball of a subject, and more particularly, to a fundus photographing apparatus having a parallax for obtaining a stereoscopic observation image of the fundus.
The present invention relates to a fundus photographing apparatus capable of photographing a single fundus image.

[0002]

2. Description of the Related Art In recent years, fundus photography has been widely used in health examinations because many useful medical findings such as arteriosclerosis and hypertension are obtained. In this case, by observing the optic disc recession three-dimensionally, glaucoma can be detected early by an adult disease test, so conventionally, in order to stereoscopically observe the fundus image, an ordinary fundus camera is operated, or the binocular fundus is operated. 2. Description of the Related Art Using a camera, two fundus images having parallax are taken, and stereoscopic observation of the fundus image is performed.

[0003]

As described above, in order to operate two ordinary fundus cameras and take two fundus images with parallax, the fundus of the subject's eye and the subject's eye whose viewpoint has been changed have to be taken. Since the camera is set in the positional relationship to take two images, it is necessary to take two images, it is difficult to take the same fundus position, and the pupil is narrowed in the first image taking There was a problem that it was not possible to obtain two fundus images with uniform exposure. Further, when photographing is performed using a binocular retinal camera, since one screen is photographed as if it were divided into two, the disadvantage that the angle of view is small and the field of view is small even if the same fundus position is photographed.

The present invention has been made in view of such a situation, and it is not necessary to set a camera at a position having parallax in order to obtain a stereoscopic observation image of a fundus, and perform a shooting operation twice. Exposure is even and the field of view is not reduced.
An object of the present invention is to provide a fundus photographing apparatus capable of automatically and easily photographing two fundus images whose viewpoints are changed by a shot.

[0005]

To achieve the above object, a fundus photographing apparatus according to the present invention comprises: an illumination optical system for illuminating the fundus of an eye to be inspected; and a fundus using a television camera based on illumination light illuminating the fundus. A fundus photographing optical system for photographing an image of a subject; a photographing diaphragm provided on the optical axis of the fundus photographing optical system so as to divide the pupil diameter into two at a conjugate position with the pupil of the eye to be examined with respect to the objective lens; Switching means, and two fundus images are obtained using the switched apertures.

Accordingly, an image of the pupil of the eye to be inspected is formed by the illumination light of the illumination optical system at the position of the photographing stop on the optical axis of the fundus photographing optical system. The pupil of the eye to be examined (without mydriasis and about 4 mm in diameter)
It is possible to easily obtain two fundus images having parallax on a television screen by using an optical path using half (for example, left and right halves) of the image.

As a means for switching the photographing aperture, for an observation aperture of a predetermined shape provided at a position conjugate with the pupil of the eye to be examined on the optical axis of the fundus imaging optical system, the aperture having a smaller aperture than the aperture of the observation aperture crosses the optical axis. Direction, and detecting that the photographic aperture being scanned has reached two predetermined positions and enabling continuous recording of two images on the left and right while the photographic aperture is passing, allows one shot to be taken. It is possible to easily obtain two fundus images for a stereoscopic observation image in which the viewpoint is changed by two optical paths.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a configuration diagram of a fundus photographing apparatus according to the embodiment, and FIG. 2 is an explanatory diagram showing a switching state of a photographing aperture provided on an optical axis of a fundus photographing optical system of the apparatus.

In FIG. 1, an illuminating optical system for illuminating the fundus of the eye 1 to be examined and a fundus for observing and recording the fundus with a color television camera 10 based on the illumination light illuminating the fundus. The photographing system 30 includes a photographing optical system and a built-in monitor optical system that allows the infrared television camera 25 to visually recognize the alignment and focus state of the photographing system 30 that is a fundus camera.
By switching the photographing diaphragm 20 provided immediately after the perforated mirror 6 on the optical axis 4 of the fundus photographing optical system, it is possible to switch the diaphragm in which the pupil diameter is divided into two right and left.
Numeral 0 is movable in three directions, that is, the direction of the optical axis 4 of the fundus imaging optical system and the horizontal and vertical directions orthogonal to the optical axis 4 by manual operation of the joystick 32 provided on the top of the gantry 31. together they are, so that it is capturing and recording of the fundus image after the positioning of the imaging system 3 by the upper portion of the shooting button 32 _first pressing operation of the joystick 32.

As an illumination light source for the fundus of the eyeball 1, a strobe discharge tube 14 used for photographing the retina of the fundus and an illumination lamp 11 used for positioning and focusing of the fundus photographing optical system are located at conjugate positions with respect to the condenser lens 12. The visible light emitted from the strobe discharge tube 14 is
5 converges in the direction of the circular slit 16, while the visible light emitted by the illumination lamp 11 passes through the condenser lens 12 and is cut by a visible light cut filter 13 so that the visible light is cut off by infrared light or near red light which does not shrink the pupil. It is arranged so that outside light is taken out and converged by the condenser lens 15 in the direction of the circular slit 16.

The focused visible light or infrared light passes through the circular slit 16 and is reflected by the mirror 17, the optical path is bent, and the light passes through the condenser lens 19 on the illumination optical axis 18 near the perforated mirror 6. The image of the circular slit is formed on the perforated mirror 6 and reflected by the mirror 6, passes through the objective lens 5 on the optical axis 4 of the fundus photographing optical system, passes through the objective lens 5, and the position of the pupil of the eyeball 1 (iris) (Center position 3) and irradiates the fundus retinal surface of the eyeball 1. The strobe discharge tube 1
4 or the illumination lamp 11 and the positions of the circular slit 16, the perforated mirror 6, and the pupil of the eyeball 1 (the center of the iris 3) are in a conjugate relationship. That is, illumination light enters the eye to be examined only from the ring-shaped passage of the circular slit 16 and irradiates the fundus through the pupil. At this time, the reflected light from the center of the cornea 2 is cut and does not directly enter the objective lens.

In the fundus photographing optical system, an optical pupil is formed on the fundus photographing optical system optical axis 4 to be located on the eye axis, at the pupil portion of the eye to be examined (the center of the iris 3) facing the eye to be examined 1. To this end, an objective lens 5 is provided. On the optical axis 4, a perforated mirror 6 is provided at a predetermined position. Immediately after that, an aperture stop 20 'for fundus observation and an aperture control means 2 for dividing and photographing two images are provided.
The photographic stop 20 driven by 1 is disposed so that the observation stop position is located at a position conjugate with the pupil of the eye to be examined, and the focus lens 7, the field stop 7 ', and the infrared light reflection /
A visible light transmitting mirror 8 and an image forming lens 9 are provided, and the position of a focus lens 7 movable in the optical axis direction is adjusted so that a CCD light receiving surface (a color TV camera for fundus imaging) 10 on the front of a rear color TV camera 10 is formed. (Not shown), a fundus image is formed in a focused state.

The fundus photographing optical system is positioned laterally of the optical axis 4 via the infrared light reflecting / visible light transmitting mirror 8 disposed at an angle of 45 ° with respect to the optical axis 4. A built-in monitor optical system including a built-in monitor 26 for visually checking the focus state is provided. That is,
The optical axis 2 is located at a predetermined position on the optical axis 22 bent by the infrared light reflecting / visible light transmitting mirror 8 in a direction orthogonal to the optical axis 4.
The optical axis 22 is bent in parallel with the optical axis 4 of the fundus photographing optical system by a mirror 23 disposed at an angle of 45 ° with respect to 2.
An imaging lens 24 sequentially at a predetermined position on the bent optical axis,
An infrared television camera 25 is provided, and an image output from the infrared television camera 25 is displayed on a screen of a built-in monitor 26 provided on the rear surface of the housing of the photographing system 30. Thus, while looking at the screen of the built-in monitor 26, the joystick 32 on the gantry 31 is operated to align the subject's eye with the imaging system 30, and the focus knob (not shown) attached to the imaging system 30 is operated. Focus.

[0014] driving the photographic stop 20 to obtain the two fundus images having different viewpoint, by pressing the shooting button 32 ₁ of the joystick 32 top of pedestal 31 upper surface, receives the signal from the control circuit 33 Drive control is performed by the aperture control unit 21. FIGS. 2A and 2B show a switching state of the photographing aperture 20 at the time of photographing the fundus by pressing the photographing button. Photographic stop 20, when pressing the shooting button 32 _1, by one shot from the state of being driven by the diaphragm control means 21 20-1 2
It moves to the state of 0-4 by, for example, a rotary solenoid or the like. FIG. 2A shows a state when positioning the eye 1 and the photographing system 30 as a fundus camera while looking at the built-in monitor 26, that is, a state from the time of positioning the eye to be inspected to the time of photographing the first image. ing. In the figure, reference numeral 20-1 denotes the position of the photographing stop 20 when observing the subject's eye, and reference numeral 20-2 denotes the position of the photographing stop 20 when photographing the first image. In this case, the optical axis 4
The observation aperture 20 'is provided with a slightly smaller diameter than the pupil 3' (pupil in the non-mydriatic state) formed above. At the time of observation, the entire shape of the observation aperture 20 ′ is formed on the optical axis 4, so that the subject's eye can be observed well, but at the time of the first image capturing, the imaging aperture 20 moves to the position of 20-2, 20 '
Is shielded, only the left half is open, and the fundus is photographed by the optical path using the left half of the observation aperture 20 '. 21 _A shooting aperture by the position detection sensor diaphragm 20 -
Detects this when a state of turning to 20-2 from the state being adapted allowed to emit flash light emitting tube 14, the movement of the photographic stop in the sensor 21 _A and described below sensor 21 _B One that detects magnetic fluctuations due to the above can be used.

FIG. 2B shows that the photographing diaphragm 20 is further rotated from the state shown in FIG. 2A to cover the left half of the observation diaphragm 20 'and open only the right half. This shows a state in which the fundus is photographed by the optical path using the right half. That is, when the photographic stop 20 is ready to 20-3 from the state of the 20-2, by detecting this by the diaphragm position detecting sensor 21 _B made to emit flash light emitting tube 14, the second sheet photographing is performed . After that, the photographing aperture continues to rotate, and the photographing is completed in the state of 20-4. And after the shooting,
The photographing aperture 20 is automatically restored to the photographing aperture position 20-1 at the time of initial fundus observation.

At the time of photographing the fundus with the photographing button ON, the states shown in FIGS. 2 (A) and 2 (B) are continuously performed in one shot. Are detected by the aperture position detection sensors 21 _A and 21 _B at the respective predetermined positions. By this detection signal, the photographic diaphragm 20 moves left and right while passing through the surface of the observation diaphragm 20 ′.
A plurality of images can be continuously photographed by the color television camera 10, and photographing signals of two fundus images from the color television camera 10 are input to the control circuit 33 and sequentially recorded in the image memory 34. it can. Then, the two fundus images of the object to be examined whose viewpoints have been changed are displayed on the screen of the monitor 35 by a conventional method for stereoscopic observation (for example, the left and right images are alternately displayed) by operating a button on an operation panel (not shown). It can be displayed as if it were flashing and looking through a liquid crystal mirror. Thus, the fundus of the eye to be examined can be three-dimensionally observed, and glaucoma can be detected early in an adult disease test by stereoscopically viewing the optic disc depression at the center of the fundus.

Next, a procedure for photographing two fundus images with different viewpoints in one shot will be described with reference to a flowchart shown in FIG. First, the subject's face is positioned by the chin rest and the forehead (step 101). Next, the illumination lamp 11 is turned on to irradiate the subject's eye with infrared illumination light in order to align the fundus camera, which is a photographing system, with the subject's eye and focus the subject's fundus (step 10).
2). A built-in monitor 2 is attached to the eye to be inspected irradiated with the infrared illumination light by using existing means (such as the joystick 32).
While viewing the image of the subject's eye irradiated with the infrared light in Step 6, the position of the fundus camera (photographing system 30) is operated to adjust the positional relationship between the subject's eye and the fundus camera (photographing system 30) (Step 10).
3). Then, the user operates the focus knob attached to the fundus camera (photographing system 30) to move the focus lens 7 to focus on the fundus (step 104). Check whether sufficient image can not be obtained on the internal Momonita 26 This (step 105), if sufficient image can not be obtained, pressing the shooting button 32 ₁ (step 106). By this button pressing operation, the photographing aperture 20 starts scanning (step 107). When the photographic stop 20 is a position detection sensor 21 _A diaphragm that came first imaging position (20-2) is detected (step 108), the strobe 14 emits light through the control circuit 33 in the detection signal, the color television camera 10 Captures a fundus image of the subject, and records the first (for example, right) fundus image in the image memory 34 via the control circuit 33 (step 109). Thereafter the photographic stop 20 continues running, when the position detecting sensor 21 _B diaphragm that came to the next photographing position (20-3) for detecting (Step 1
10), the strobe 1
4 emits light, the color television camera 10 captures a fundus image at the same position, and the second (for example, left position) fundus image is recorded in the image memory 34 via the control circuit 33 (step 111). The two fundus images with different viewpoints recorded are displayed by an existing method such as alternately blinking the left and right images for a liquid crystal eye mirror in order to perform stereoscopic observation on the screen of the monitor 35. can do.

In the preferred embodiment, the observation aperture 20 'provided on the optical axis 4 of the fundus photographing optical system at the position conjugate with the pupil 3 of the eye to be examined has a circular shape slightly smaller in diameter than the imaged pupil 3'. The observation aperture 20 having another shape, for example, a horizontally long shape.
₁ '(see FIG. 4), even better, of two-eye shape observation aperture 20 _2'
(See FIG. 5). The point is that an observation aperture of any shape can be used as long as it can capture two images whose viewpoints are sequentially changed in accordance with the movement of the imaging aperture 20. such as 2-screen position detecting sensor 21 _a, 21 _B diaphragm for photographing also possible to use any, of capable of various modifications without departing from the scope and spirit of the invention.

[0019]

According to the fundus photographing apparatus of the present invention, the pupil diameter is divided into two by switching the photographing aperture, and two fundus images whose viewpoints are changed are photographed. Therefore, there is no need to change the viewpoint and take two shots. Even if the exposure is uniform, the field of view is not reduced, and two fundus images with parallax for stereoscopic observation images can be easily shot and recorded by a TV camera. By viewing the optic nerve depression in the fundus three-dimensionally, it can be used for an adult disease test and contribute to early detection of glaucoma.

According to the second aspect of the present invention, two fundus images for stereoscopic observation images having parallax can be automatically and easily captured with one shot.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a preferred embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a switching state of a photographing aperture.

FIG. 3 is a flowchart illustrating a procedure for capturing and recording two fundus images whose viewpoints are changed in one shot.

FIG. 4 is a front view showing another shape of the observation stop.

FIG. 5 is a front view showing still another shape of the observation stop.

[Explanation of symbols]

1 ... eye to be examined, 3 ... pupil, 3 '... pupil formed image, 4
… Optical axis of photographing optical system, 8… infrared reflective visible light transmitting mirror,
10 ... Cararo TV camera 11 ... Lighting lamp
13: visible light cut filter, 14: strobe discharge tube, 20: shooting aperture, 20 ': observation aperture, 21 ...
Aperture control means, 21 _A , 21 _B ... aperture position detection sensor, 25 ... infrared television camera, 26 ... built-in monitor,
30: shooting system, 32: joystick, 32 ₁
... Shooting button.

Claims (2)

[Claims] An illumination optical system for illuminating a fundus of an eye to be examined, a fundus imaging optical system for photographing the fundus by a television camera based on illumination light illuminating the fundus, and an optical axis of the fundus imaging optical system. A photographic aperture provided at the conjugate position with the pupil of the eye to be examined with respect to the objective lens so as to divide the pupil diameter into two, and switching means for the photographic aperture; two fundus images using the switched apertures A fundus photographing apparatus characterized in that a fundus is obtained. 2. An iris diaphragm switching means, wherein an iris having a smaller aperture than the aperture of the iris is formed on the optical axis of the fundus imaging optical system. It scans in the transverse direction, detects that the shooting aperture during scanning has reached two predetermined positions, and enables continuous recording of two left and right images while the shooting aperture passes. The fundus photographing apparatus according to claim 1.