JPH08206079A - Ophthalmological device - Google Patents

Abstract

PURPOSE: To effectively lead a light flux from a light source to an eyeground through a columnar lens. CONSTITUTION: An infrared beam of light emitted by a laser diode 9 is image formed by a convex columnar lens 8 on an image formation surface P3 as a linear flux image stretching perpendicularly to the plane in which illustration is made, image formed in a dot form in the center of a slit provided in a mirror 4, reflected by a galvanometric mirror 2, and projected on the eyeground Er as a linear flux image upon dot-form image formation on the pupil Ep of the eye to be inspected. When the galvanometric mirror 2 is rotated, the eyeground Er is scanned in one direction by the linear flux image centering on the image formed position on the pupil Ep. The reflected beam of light returns following the same route, and is reflected by the mirror 4 to reach a unidimensional CCD 12. This light reception signal is fed to a TV monitor 14 via a signal processor 13 and displayed as a two-dimensional eyeground image Er'. Further the signal processor 13 extracts the image signal given on the rasters L1, L2 of the monitor 14 and determines the amount of eye E movement in the direction of the line of view through determination of the correlation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmologic apparatus for observing the fundus with a point-like or linear luminous flux, such as an ophthalmoscope, a fundus blood flow meter, a fundus perimeter, a coagulator, and an eye movement analyzer. It is a thing.

[0002]

[Prior art]

(B) In the conventional visual axis detection device, the visual axis is obtained by using the fundus image which is illuminated entirely.

(B) In the fundus visual field measuring device using the scanning optical system, the inspection light beam is projected through the scanning optical system.

(C) In the fundus blood flow meter, the fundus illuminating light is visible light that is entirely illuminated, and the measuring light is visible light having a specific wavelength.

[0005]

[Problems to be Solved by the Invention]

(1) In the conventional example (a), it is necessary to use infrared light in order to use it with a non-mydriatic pupil, but with full-face illumination, the contrast of the fundus vascular image is low and it is not possible to detect the line of sight accurately.

(2) The conventional example (b) has a problem that the inspection light beam is limited by the scanning optical system. Also,
The same problem occurs in photocoagulators. Furthermore, light irradiation becomes intermittent.

(3) In the prior art example (C), it was necessary to apply the mydriatic drug to the eye drop before using the device.

The object of the present invention is to solve the above-mentioned problems (1) and (3).
It is an object of the present invention to provide an ophthalmologic apparatus which can be used with non-mydriasis and can detect the line-of-sight direction with high accuracy.

Another object of the present invention is the above-mentioned problem (2).
It is an object of the present invention to provide an ophthalmologic apparatus which solves the above problem and has no influence on the movement of the eye because the light flux is not limited by the scanning optical system, and the illumination light flux is continuous, thus reducing the burden on the light source.

[0010]

An ophthalmologic apparatus according to a first aspect of the invention for achieving the above object is a scanning optical system for scanning a fundus of an eye to be inspected with an infrared light flux, and a reflected light from the fundus of the eye. A fundus image means for receiving a photoelectric sensor through a scanning optical system to obtain a fundus image, and a line of sight for recognizing the position of the fundus image based on a signal from the fundus image means and detecting a movement of the eye to be examined in the direction of the line of sight. Direction detecting means.

An ophthalmologic apparatus according to a second aspect of the present invention comprises a scanning optical system for scanning the fundus of the eye to be inspected, and reflected light from the fundus of the eye due to the scanning luminous flux received by a photoelectric sensor via the scanning optical system to form a fundus image. And a light beam projection optical system for projecting a light beam having a wavelength different from the light beam onto the eye to be examined via a light splitting member provided between the scanning optical system and the eye to be examined. .

An ophthalmologic apparatus according to a third aspect of the present invention comprises an illumination optical system for illuminating the fundus in a spot-like or linear manner with the first laser light in the infrared wavelength range, and a fundus portion illuminated by the illumination optical system. A light receiving optical system for receiving the reflected light flux and a second laser light in an infrared wavelength range different from the first laser light illuminate the measurement light flux on the fundus, and the photoelectric sensor receives the light flux on the fundus due to the measurement light. However, a fundus measuring means for obtaining ophthalmic measurement information is provided.

[0013]

The ophthalmologic apparatus of the first invention having the above-described structure scans the fundus of the eye to be inspected with the infrared light flux, receives the reflected light from the fundus into the photoelectric sensor through the scanning optical system, and two-dimensionally A typical fundus image is obtained, the position of this fundus image is analyzed, and the movement of the line of sight of the subject's eye is recognized.

In the ophthalmologic apparatus of the second invention, the light beam splitting member splits the optical path of the scanning optical system for observing the fundus from the optical path of the projection optical system for measurement, and is used for observing the fundus without passing through the scanning optical system. A light beam having a wavelength different from that of the light beam is projected on the eye to be examined.

The ophthalmologic apparatus of the third invention is the first in the infrared wavelength range.
The fundus of the eye is illuminated by the laser light of (1) to obtain an image of the fundus of the eye, and a measurement light beam is projected onto the fundus of the eye by the second laser light having an infrared wavelength region different from that of the first laser light to obtain ophthalmic measurement information.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiments. FIG. 1 is a configuration diagram of the first embodiment, and is an example applied to a fundus mirror for observing a fundus and a line-of-sight tracking device for analyzing eye movements. A galvanometric mirror 2 is arranged on an optical path O1 behind the objective lens 1 facing the eye E to be inspected, and a lens 3 and a slit aperture as shown in FIG. 2 are provided on the optical path O2 in the reflection direction of the galvanometric mirror 2. A perforated mirror 4 and a mirror 5 which have a conjugate with the pupil Ep of the eye E to be inspected
Are arranged.

Further, on the optical path O3 in the incident direction of the mirror 5, a lens 6, a lens 7, a convex cylindrical lens 8 having a refracting power only in the plane of the drawing, and a laser diode 9 emitting infrared light.
Are arranged to form a projection optical system. Further, on the optical path O4 in the reflection direction of the perforated mirror 4, the mirror 10, the lens 11, and the one-dimensional C in which the light receiving elements are arranged in the direction perpendicular to the paper surface.
The CDs 12 are arranged to form a light receiving optical system, and the output of the one-dimensional CCD 12 is sequentially connected to the signal processor 13 and the television monitor 14. The lens 6 of the projection optical system and the lens 11 of the light receiving optical system are connected by a connecting member 15 and move along the direction of the arrow so as to match the diopter of the eye to be inspected.

Further, broken lines on the optical paths O1 to O3 are fundus image forming planes P1 to P3 formed by the lenses, and the image forming plane P1 is the objective lens 1.
The rear focal plane, and the image plane P2 is the rear focal plane of the lenses 6 and 11. The image plane P3 is a focal plane of the convex cylindrical lens 8 and is also a conjugate plane with the one-dimensional CCD 12.

The infrared light emitted from the laser diode 9 is
The convex cylindrical lens 8 diverges in the direction perpendicular to the paper surface without the refracting power of the convex cylindrical lens 8, and is imaged on the image forming plane P3 as a linear light beam image whose longitudinal direction is along the direction perpendicular to the paper surface. The image is again imaged by the lens 6 via the mirror 5 and the perforated mirror 4 on both imaging planes P2. At this time, the light emitting point of the laser diode 9 is imaged as a spot light beam image by the lens 7 at the center of the slit aperture 4a of the perforated mirror 4, and the light flux emitted from the slit aperture 4a as the second point light source is , The image plane formed by the lens 6 as described above
It is imaged as a linear light beam image on P2, is formed as a spot light beam image on the galvanometric mirror 2 by the lens 3, and is formed as a linear light beam image on the image forming surface P1. After being formed as a spot light flux image on the pupil Ep of the eye E, it is projected on the fundus Er as a linear light flux image.

By rotating the galvanometric mirror 2, the fundus Er is scanned in a line-to-line direction with a linear luminous flux image centered on the spot luminous flux image on the pupil Ep. Accordingly, the reflected light from the fundus Er returns through the same optical path, is reflected by the perforated mirror 4 and the mirror 10, respectively, passes through the lens 11, and is received by the one-dimensional CCD 12.

At this time, the eye E to be inspected by the perforated mirror 4.
The projected light beam and the received light beam are separated on the pupil Ep of
The light flux is projected from the center of the pupil Ep onto the fundus Er, and the fundus reflected light flux is extracted from around the pupil Ep. Further, by forming the opening 4a of the perforated mirror 4 into a slit shape, harmful scattered light generated in the anterior segment of the eye E is prevented from entering the light receiving optical system. Instead of the perforated mirror 4, a half mirror may be arranged on one side of the optical path O2. In this case, the light flux is projected onto the fundus Er from one side of the optical path O1 on the pupil Ep plane, and the reflected light flux from the fundus Er is extracted from the other side.

In the signal processor 13, the one-dimensional CCD 1
A video signal is created by adding a synchronizing signal for synchronizing with the scanning by the galvanometric mirror 2 to the light receiving signal from 2, and this video signal is displayed on the television monitor 14 as a two-dimensional fundus image Er '. .

When this embodiment is used as a fundus mirror, for example, fundus observation by the television monitor 14 may be performed.
In order to focus the fundus image Er ', the connecting member 15 is driven and the lenses 6 and 11 are moved in the direction of the arrow in conjunction with each other, so that focusing for diopter correction and zooming operation are performed at the same time. The focus lens system and the variable power lens system may be moved independently.

When the fundus image Er 'is in focus, the image plane P1 ...
The P3 and the one-dimensional CCD 12 are simultaneously conjugated with the fundus Er of the eye E to be examined. Since the light receiving aperture of the one-dimensional CCD 12 has substantially the same shape as the linear light flux image on the image plane P3 formed by the convex cylindrical lens 8, a one-dimensional conjugate focus optical system is configured. become. Therefore, the luminous flux from the laser diode 9 which is a light source can be efficiently used, and a clear fundus image Er 'can be obtained without using a photoelectric sensor having a particularly high sensitivity. Further, since it is a one-dimensional scanning system, the structure is simple and it is possible to obtain a high-contrast fundus image. Further, since the projected light flux is condensed in a spot shape on the pupil Ep and then projected on the fundus Er, the eye E to be examined having a small pupil E
It becomes possible to observe the fundus.

Alternatively, this embodiment can be used as an eye tracking device, and the displacement of the fundus image Er 'of the television monitor 14 can be detected to detect the movement of the eye E to be examined in the line-of-sight direction. In this embodiment, in the signal processor 13, the video signal S on the lines L1 and L2 orthogonal to each other at the center of the screen of the television monitor 14
1 and S2 are extracted for each screen, AD-converted, stored in an internal memory, and correlations of the video signals S1 and S2 are obtained.

FIGS. 3 and 4 show video signals S1 and S2 extracted from lines L1 and L2 on the screen of the television monitor 14 shown in FIG. 1, respectively. Since infrared light is used in this embodiment, the fundus Er
The upper blood vessel Ev becomes darkest as compared with the surroundings. Therefore, FIG.
The signal level of the teat ML is highest as shown in
The signal level of Cp is slightly lower than the surroundings. On the other hand, the signal level of the blood vessel Ev is the smallest and is represented by a deep and sharp groove Ev on the video signal S2 as shown in FIG.

To obtain the correlation, the current TV monitor 1
When the video signals S1 and S2 on the lines L1 and L2 of the screen of 4 and the video signals S1 'and S2' on the lines L1 and L2 of the screen one screen before,
Subtract between video signals S1 and S1 'and video signals S2 and S2',
The position to be subtracted is gradually shifted, the total sum of the subtraction results is calculated, and a correlation diagram is obtained. Find the amount of deviation between the video signals S1 and S1 'and the image signals S2 and S2' for which the total sum is the minimum, and convert these deviations into the amount of movement and the direction of movement of the line of sight based on the fundus image magnification, etc. .

When the eye E to be inspected does not move, the lines L1 and L2
In both directions, the shift amount between the video signals S1 and S2 is zero, which is the minimum value. For example, when a video signal of 30 screens is obtained per second, the above calculation is performed every 30 mS. In addition, in order to obtain the correlation, 1 from the horizontal and vertical lines
Although the video signals S1 and S2 are extracted one by one, the video signals on a plurality of lines may be extracted and the correlation may be obtained by balancing the calculation time and the accuracy. Further, since it is confocal, there is no wraparound from other parts even with infrared light, and the contrast of blood vessels is high. Therefore, accurate measurement becomes possible.

FIG. 5 is a configuration diagram of a second embodiment applied to a fundus blood flow meter, and an objective lens 2 facing the eye E to be examined.
A rotator prism 22 and a movable mirror 23 are arranged on the optical path O5 behind 1 and the movable mirror 23 is a motor 24.
Is rotated about an axis in the paper. Further, on the optical path O6 in the reflection direction of the movable mirror 23, there is a lens 25, a half mirror 26 which is in a conjugate relationship with the pupil Ep of the eye E to be inspected and is provided on one side of the optical path O6, a dichroic mirror 27, and an element in the direction perpendicular to the plane of the drawing. One-dimensional CCDs 28 in which are arranged are arranged.

A dichroic mirror 29, a cylindrical lens 30 having a refractive power in the direction perpendicular to the plane of the drawing, and a blood vessel observing laser diode 31 emitting infrared light are arranged on the optical path O7 in the incident direction of the half mirror 26. A light splitting member 32 and a photoelectric sensor 33 are arranged on the optical path of the dichroic mirror 27 in the reflection direction. The dichroic mirror 29 and the light splitting member 32 are sequentially arranged on the same optical path O8 in the emission direction of the measuring laser diode 34, and the blood vessel observing laser diode 31 and the measuring laser diode 34 are different from each other. Laser diode 3 that emits light in the infrared region, especially for blood vessel observation
1 emits light having a wavelength in the vicinity of 850 μm.

Further, the one-dimensional CCD 28 and the photoelectric sensor 33.
Are connected to the signal processor 35, and the output of the signal processor 35 is connected to the motor 24.

The measurement light beam emitted from the measurement laser diode 34 is reflected by the dichroic mirror 29 and the half mirror 26, projected onto the fundus Er of the eye E as a spot light beam, and flows in the blood vessel Ev on the fundus Er. Received a Doppler shift. The reflected light beam from the fundus Er returns through the same optical path, is reflected by the dichroic mirror 27, is transmitted through the light splitting member 32, and is received by the photoelectric sensor 33. At this time, part of the measurement light flux emitted from the measurement laser diode 34 passes through the dichroic mirror 29, interferes with the fundus reflected light flux that is reflected by the light splitting member 32 and is Doppler-shifted, and is received by the photoelectric sensor 33. . Therefore, the received light signal includes a beat signal, and the signal processor 35 frequency-analyzes the beat signal to obtain the blood flow velocity in the blood vessel Ev on the fundus Er.

The near-infrared light flux emitted from the blood vessel observing laser diode 31 is converted into a slit light flux S extending in the direction perpendicular to the paper surface by the cylindrical lens 30, reflected by the dichroic mirror 29 and the half mirror 26, and the lens 38.
Is reflected by the movable mirror 23, passes through the rotator prism 22, the objective lens 21, and is reflected by the half mirror 26.
From one side of the optical path O5 of the pupil Ep plane of the eye E to be inspected, the slit light beam S
Is projected on the fundus Er as. The light reflected by the fundus Er is the pupil Ep.
The light is extracted from the other side of the optical path O5 of the surface, transmitted through the dichroic mirror 27, and received by the one-dimensional CCD 28 as a blood vessel image. The light reception signal of the one-dimensional CCD 28 is output to the signal processor 35, the amount of movement of the blood vessel image in the arrangement direction of the elements of the one-dimensional CCD 28 is calculated, and the involuntary eye movement of the eye E to be examined in this direction is monitored.

FIG. 6 shows the relationship between the slit light beam S and the spot light beam P on the fundus Er of the eye E to be inspected. The spot light beam P is always focused on the center of the slit light beam S. When the rotator prism 22 is rotated around the optical path O5, the slit light flux S is rotated around the spot light flux P, and the movable mirror 23 is rotated.
When is rotated, the slit light beam S and the spot light beam P move along the longitudinal direction of the slit light beam S while maintaining the above relative positional relationship.

At the time of measurement, the examiner rotates the rotator prism 22 so that the slit luminous flux S becomes the blood vessel Ev to be measured.
Set the measurement direction so that it is orthogonal to. The signal processor 35 analyzes the position of the blood vessel Ev based on the light receiving signal of the one-dimensional CCD 28 and creates a control signal for the movable mirror 23 so that the blood vessel Ev is received at the center of the one-dimensional CCD 28.
During this period, the one-dimensional CCD 28 images only the area on the fundus Er illuminated by the slit light flux S.

Therefore, since the light-receiving area of the one-dimensional CCD 28 is limited, the light flux does not wrap around, and the reflectance of the slit light flux S is different between the blood vessel Ev and the portion other than the blood vessel Ev. Therefore, the computer in the signal processor 35 can recognize the position of the blood vessel Ev. The signal processor 35 rotates the movable mirror 23 by controlling the motor 24 based on the position of the blood vessel Ev so that the spot light flux P matches the blood vessel Ev. During the measurement, the signal processor 35 repeatedly performs this calculation to compensate for the movement of the subject's eye E so that the spot light flux P always matches the blood vessel Ev.

When the measurement site is selected, the measurement light beam is applied to the blood vessel Ev from the inclined direction, and the fundus reflected light by this is received within the plane.

In this embodiment, since the measuring light and the blood vessel observing light are both infrared light, blood flow can be measured with a non-mydriatic pupil.
An infrared fundus mirror as shown in FIG. 1 can be combined as the fundus observing means. In this case, the laser diode for observing the fundus emits light having a different wavelength from the laser diode 31 for blood vessel observation and the laser diode 34 for measurement, and the dichroic mirror may divide the three light beams. Although the slit irradiation is used for blood vessel observation, a confocal optical system that scans with a point beam may be used.

FIG. 7 shows the configuration of the third embodiment, which is an example of a fundus perimeter. A dichroic mirror 42 that reflects visible light is arranged in the optical path O9 behind the objective lens 41 facing the eye E to be inspected.
A liquid crystal display plate 44 provided near the rear focal point of the objective lens 41 is disposed in the reflection direction of, and the output of the controller 45 is connected to the liquid crystal display plate 44.

When observing the fundus Er, the fundus observation system 43
The illuminating light flux emitted from is transmitted through the dichroic mirror 42, passes through the objective lens 41, and is projected onto the fundus Er of the eye E to be examined. The reflected light flux here returns through the same optical path, is imaged in the fundus oculi observation system 43, and is displayed as a fundus image on an external television monitor.

As the fundus observation system 43, a one-dimensional scanning confocal optical system as shown in FIG. 1 can be used. Alternatively, a confocal optical system that two-dimensionally scans the fundus Er with a point-like light beam may be used as in the related art.

When measuring the visual field, the symbol generating circuit in the controller 45 displays the fixation target Sa and the measurement target Sb on the display surface of the liquid crystal display panel 44 as shown in FIG. Further illuminated by background light. The illuminance of the background light can be set arbitrarily by the controller 45.

The light flux from the liquid crystal display plate 44 is reflected by the dichroic mirror 42, passes through the objective lens 41, and is projected onto the fundus Er of the eye E to be inspected. Mark Sa is presented. The examiner makes the examinee fixate on the fixation target Sa, and instructs the response target means to respond when the measurement target Sb is visible. The controller 45 moves the measurement target Sb on the liquid crystal display plate 44, and the subject visually recognizes and responds to the measurement target Sb. A computer in the controller 45 determines the visual recognition response of the subject and measures the visual field.

In this embodiment, since the light flux from each element on the display surface of the liquid crystal display plate 44 spreads over the entire aperture of the objective lens 41, the liquid crystal display plate 4 will be moved even if the eye E to be inspected moves a little.
Since the screen of 4 does not disappear, fatigue of the subject is reduced. In addition, instead of the objective lens 41, 4
It is also possible to use a surface mirror.

Instead of displaying the measurement target Sb on the liquid crystal display plate 44 or the CRT, the measurement target Sb may be projected by using a light source to optically move the presentation position of the measurement target Sb. . Also in this case, it is possible to thicken the target projection light flux.

If the liquid crystal display plate 44 is capable of color display, it is possible to freely present a target with white or colored light. Alternatively, if a laser light source is provided instead of the liquid crystal display plate 44, a laser coagulator that fixes the fundus Er can be configured. In this case, if an argon laser is used, it is necessary to increase the diameter of the irradiation light beam depending on the size of the spot light beam on the fundus Er, but in this embodiment, the laser light is emitted through the fundus Er without passing through the scanning optical system. Since it irradiates the eye, a light beam with a high degree of convergence is emitted to the fundus Er.
It becomes possible to irradiate. Further, continuous light can be used to irradiate a desired position on the fundus Er with laser light.

[0047]

As described above, in the ophthalmologic apparatus according to the first aspect of the invention, the fundus observation means is composed of the confocal optical system.
Since a high-contrast fundus image can be obtained even with infrared light, the position of the fundus image can be electronically recognized, and the movement of the line of sight can be accurately known.

In the ophthalmologic apparatus according to the second aspect of the present invention, since the measuring light beam is projected without passing through the scanning optical system, the diameter of this light beam can be increased and continuous light can be emitted.

The ophthalmologic apparatus according to the third invention comprises an observation light beam,
Since the measurement light fluxes are infrared rays having different wavelengths, it is possible to observe and measure the fundus of the eye to be inspected without a non-mydriasis.

[Brief description of drawings]

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

FIG. 2 is a front view of a perforated mirror.

FIG. 3 is an explanatory diagram of a video signal extracted from a horizontal line on the screen of the television monitor.

FIG. 4 is an explanatory diagram of a video signal extracted from a vertical line on a screen of a television monitor.

FIG. 5 is a configuration diagram of a second embodiment.

FIG. 6 is an explanatory diagram showing a relationship between a slit light beam and a spot light beam on the fundus of the eye to be inspected.

FIG. 7 is a configuration diagram of a third embodiment.

FIG. 8 is a front view of a liquid crystal display panel.

[Explanation of symbols]

 2 Galvanometric mirror 8 Convex cylindrical lens 9 Laser diode 12, 28 One-dimensional CCD 30 Cylindrical lens 31 Laser diode for blood vessel observation 33 Photoelectric sensor 34 Laser diode for measurement 43 Eye fundus observation system 44 Liquid crystal display plate

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area A61B 3/12 E

Claims (3)

[Claims] 1. A scanning optical system that scans the fundus of the eye to be inspected with an infrared light beam, and a fundus imaging unit that receives reflected light from the fundus of the eye to a photoelectric sensor via the scanning optical system to obtain a fundus image. An ophthalmologic apparatus comprising: a line-of-sight direction detection unit that recognizes the position of the fundus image based on a signal from the fundus imaging unit and detects movement of the eye to be examined in the line-of-sight direction. 2. A scanning optical system for scanning the fundus of the eye to be inspected, and a fundus imaging means for receiving reflected light from the fundus of the eye due to the scanning light flux to a photoelectric sensor via the scanning optical system to obtain a fundus image, An ophthalmologic apparatus comprising: a light beam projection optical system for projecting a light beam having a wavelength different from the light beam onto the eye to be examined through a light splitting member provided between the scanning optical system and the eye to be examined. 3. An illumination optical system for illuminating the fundus in a spot or line shape with a first laser beam in the infrared wavelength range, and a light receiving optic for receiving a reflected light beam from a fundus portion illuminated by the illumination optical system. A system and a second laser light in an infrared wavelength region different from the first laser light illuminate the fundus with a measurement light beam,
Receive the luminous flux at the fundus due to the measurement light to the photoelectric sensor,
An ophthalmologic apparatus comprising: a fundus measuring unit that obtains ophthalmic measurement information.