JP2003126044A - Ophthalmologic measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means for measuring the test eyes using an ultrashort light pulse whose color from its tip to an end continuously changes along the passage of time. SOLUTION: The ultrashort light pulse reflected from a test object S is different in its ongoing position depending on the height of the test object S, for the light pulse P1 reflected from a higher position is in a progressed position than that of the light pulse P2 reflected from a lower position. A tip of the wave length of a chirp light pulse is longer than that of an end of the pulse. The frequencies f on a cut-out position A common to the light pulse P1 reflected from a higher position at a cut-out timing T on the cut-out timing axis L and the light pulse P2 reflected from a lower position are different, and a colored image Pb close to blue and a colored image Pr close to red are obtained from the cut-out two-dimensional image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmologic measuring apparatus using ultra-short pulsed light that is chirped so that the color of one pulsed light continuously changes from time to time.

[0002]

2. Description of the Related Art In conventional ophthalmologic measurement, an index is projected on an eye to be examined, and the size and shape of the eye to be examined are obtained from blurring or deviation of the index image reflected from the eye to be examined.

[0003]

However, in order to obtain three-dimensional information by such a method, there is a labor and time delay due to optical scanning or the like, variations in the intensity of reflected light from the eye to be examined, and the limit of the roughness of the index. There is a limit in accuracy due to the above.

An object of the present invention is to solve the above problems and to provide an ophthalmologic measuring apparatus which can obtain three-dimensional information of an eye to be inspected by using ultrashort pulsed light without time delay.

[0005]

In order to achieve the above object, an ophthalmologic measuring apparatus according to the present invention is an ultrashort chirp that is such that the color of one pulsed light changes continuously from time to time. Pulsed light generating means, a projection optical system for projecting the pulsed light toward the eye to be examined, a light receiving optical system for receiving the ultrashort pulsed light reflected at a predetermined part of the eye to be examined, and arranged in the light receiving optical system An ultra-high-speed optical shutter that cuts out the ultra-short pulsed light reflected at the predetermined portion at a predetermined timing, and a conjugate position with the predetermined portion with respect to the light-receiving optical system for receiving the light beam cut out by the ultra-high-speed optical shutter. The arranged light receiving means, a calculating means for calculating the shape characteristic of the predetermined portion from the spectral distribution information obtained by the light receiving means, and the spectral distribution characteristic or the shape characteristic obtained by the calculating means. And an outputting means for outputting

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail based on the illustrated embodiments. FIG. 1 is a configuration diagram of a fundus measuring apparatus using ultrashort pulsed light according to the first embodiment, in which an objective lens 1, a beam splitter 2, and an illumination side pinhole are provided in front of an eye E to be inspected. 1 aperture stop 3, relay lens 4, chirped ultra-short pulsed light generator 5,
Mode-locked titanium sapphire laser light sources 6 are sequentially arranged. Further, in the reflecting direction of the beam splitter 2, a second aperture stop 7 which is a light receiving side pinhole, a projection lens 8, an ultrafast nonlinear optical shutter 9 made of carbon disulfide molecular liquid, and a two-dimensional color image pickup device 10 are arranged. To do. Also,
A timing device 11 for cutting out an image is connected between the ultra-high speed nonlinear optical shutter 9 and the mode-locked titanium sapphire laser light source 6.

The light emitted from the mode-locked titanium sapphire laser light source 6 is converted by the chirped ultrashort pulse light generator 5 into an optical pulse whose color changes regularly with time. This chirp light is a light that confines light in a fiber having an extremely thin core with a high refractive index and guides it to cause a nonlinear optical effect and frequency modulation of an optical pulse. The light is focused on the first aperture stop 3 by the lens 4. The light from the first aperture stop 3 passes through the beam splitter 2 and
After the light is focused near the iris of the eye E through the objective lens 1, the fundus Er is irradiated.

Next, the light reflected by the fundus Er exits the iris again and enters the objective lens 1, and the beam splitter 2
After being reflected by the beam splitter 2, the light enters the projection lens 8 via the second aperture stop 7 which is placed conjugate with the first aperture stop 3 with respect to the beam splitter 2. The projection lens 8 is arranged such that the second aperture stop 7 is at the front focal position, and collects the light from the fundus Er that has passed through the projection lens 8.

The light that has passed through the projection lens 8 is projected onto the two-dimensional color image pickup device 10 through the ultra-high speed nonlinear optical shutter 9, and the reflected light from the fundus Er is converted into the timing device 1.
By cutting out at a certain timing with 1, the fundus E
Since a two-dimensional color image having a color distribution according to the depth shape of r is obtained, this is converted into shape characteristics and output to a color monitor, a color printer, or the like (not shown).

FIG. 2 is an explanatory view of the principle of cutting out a color image. The pulsed light reflected by the object S to be inspected differs in the traveling position of the optical pulse due to the unevenness of the object S to be inspected at the reflection position, and the high position. The light pulse P1 reflected at the position is at a position more advanced than the light pulse P2 reflected at the low position.

The chirped pulsed light has a longer wavelength at the front end of the pulse than at the end of the pulsed light, and is a light pulse P1 reflected at a high position.
And the light pulse P2 reflected at a low position has a different frequency f at the cut-out position A at the cut-out timing T on the cut-out timing axis L, and the cut-out two-dimensional image is a blue-colored image Pb. A red-colored image Pr is obtained.

FIG. 3 shows the color image distribution on the light receiving surface 10a of the two-dimensional color image pickup device 10 in isopter display. The red area R, the orange area O, the yellow area Y, and the green area G are shown according to the height of the reflecting surface. It becomes the blue region B and the like.

FIG. 4 shows an image picked up by the two-dimensional color image pickup device 10 on a color monitor screen, and a plurality of color distributions C1, C2 and the like are displayed in the image pickup area X. These color distributions C1 and C2 are converted into height information, and the detailed relationship between color and height is displayed by the color scale 21. A plurality of color distributions and color scales are displayed in a continuous spectrum or step form.

The height information can be displayed as values at various cross sections, and the height at the cross section Y is indicated by the scale 21 and the elevation line H, for example. In addition,
The cross section can be freely rotated and moved, and if the second cross section Y ′ is taken, the corresponding elevation line is shown.

FIG. 5 is a block diagram of the ophthalmologic measuring apparatus according to the second embodiment, which has an afocal light receiving system. The fundus illumination system is common to that of the first embodiment and is not shown. In the present embodiment, the adapter lens 31 is provided between the eye E to be examined and the objective lens 1. The anterior segment Ef of the eye E to be examined is conjugated with the two-dimensional color imaging device 10 with respect to the adapter lens 31, the objective lens 1, the beam splitter 2, the second aperture stop 7, the projection lens 8, and the ultra-high-speed nonlinear optical shutter 9. It is in the position.

The light emitted from the laser light source through the first aperture stop 3 passes through the beam splitter 2 and is once condensed by the objective lens 1 and then by the adapter lens 31 arranged at the rear focal point. It becomes parallel light and is reflected by the anterior segment Ef toward the eye E to be examined.

Next, the light reflected by the anterior segment Ef again enters the objective lens 1 through the adapter lens 31, is reflected by the beam splitter 2, and then passes through the second aperture stop 7 and its front focal point. The light enters the projection lens 8 arranged so that its position is the position of the second aperture stop 7.

The light that has passed through the projection lens 8 is projected onto the two-dimensional color image pickup device 10 through the ultra-high speed nonlinear optical shutter 9. When the reflected light is cut out at a certain timing by the timing device 11, the anterior segment Ef of the anterior segment Ef. A two-dimensional image having a color distribution according to the shape is obtained. The handling of this image is the same as the handling of the reflected light from the fundus.

[0019]

As described above, the ophthalmologic measuring apparatus according to the present invention projects ultrashort pulsed light whose color continuously changes with time from the tip to the end of one pulsed light onto the eye to be examined. By cutting out the ultrashort pulsed light reflected from the eyepiece at a predetermined timing with an ultrafast optical shutter, it is possible to obtain three-dimensional information of the eye to be inspected without a time delay such as optical scanning.

Further, the ophthalmologic measuring apparatus according to the present invention does not require a special operation such as optical scanning, and the three-dimensional shape of the eye to be inspected even in the case of fluctuating in an extremely short time, that is, at a high speed. It is possible to measure.

Further, the ophthalmologic measuring apparatus according to the present invention can accurately correspond the measured value and the measured position by keeping the object to be inspected and the two-dimensional color image pickup device optically substantially conjugate.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an ophthalmologic measuring apparatus according to a first embodiment.

FIG. 2 is an explanatory diagram of a principle of cutting out a color image.

FIG. 3 is an explanatory diagram of a clipped image on a two-dimensional color image sensor.

FIG. 4 is an explanatory diagram of a display screen of measurement data obtained from a two-dimensional color image sensor.

FIG. 5 is a configuration diagram of an ophthalmologic measuring apparatus according to a second embodiment.

[Explanation of symbols]

1 Objective lens 2 beam splitter 3 First aperture stop 4 relay lens 5 Ultrashort pulse light generator 6 mode-locked titanium sapphire laser light source 7 Second aperture stop 8 Projection lens 9 Ultra-high speed nonlinear optical shutter 10 Two-dimensional color image sensor 11 Timing device 31 Adapter lens

Claims (9)

[Claims] 1. An ultra-short pulsed light generation means that is chirped so that the color of one pulsed light continuously changes from time to time, and a projection optical system that projects the pulsed light toward an eye to be examined. And a light receiving optical system that receives the ultrashort pulsed light reflected at a predetermined portion of the eye to be inspected, and an ultra-high speed that cuts out the ultrashort pulsed light that is placed in the light receiving optical system and reflected at the predetermined portion. An optical shutter,
A light receiving unit disposed at a conjugate position with the predetermined region with respect to the light receiving optical system for receiving the light beam cut out by the ultra-high-speed optical shutter, and a shape characteristic of the predetermined region is calculated from spectral distribution information obtained by the light receiving unit. An ophthalmologic measuring apparatus, comprising: a calculating unit that outputs the spectral distribution characteristic or an output unit that outputs the shape characteristic obtained by the calculating unit. 2. The projection optical system includes an objective lens, a beam splitter, and a first aperture stop arranged substantially conjugate with the anterior ocular segment of the subject's eye with respect to the objective lens, and the light receiving optical system includes the objective. A lens, a second aperture stop arranged substantially conjugate with the anterior ocular segment of the eye to be examined with respect to the objective lens, and the second aperture stop.
2. The ophthalmology according to claim 1, further comprising: a projection lens arranged so that the aperture stop of the lens is located at a front focal position, and the projection optical system and the light receiving optical system divide an optical path by the beam splitter. Measuring device. 3. The ophthalmologic measuring apparatus according to claim 1, wherein the predetermined portion of the eye to be inspected is a fundus, and the light receiving unit is arranged substantially conjugate with the fundus with respect to the light receiving optical system. 4. The ophthalmologic measuring apparatus according to claim 1, wherein the shape characteristic is a two-dimensional contour line and scale converted into a distance. 5. The ophthalmologic measuring apparatus according to claim 1, wherein the shape characteristic is a bird's-eye view and a scale converted into a distance. 6. The ophthalmologic measuring apparatus according to claim 1, wherein the shape characteristic is a two-dimensional contour line converted into a distance and a predetermined cross section. 7. The ophthalmologic measuring apparatus according to claim 6, wherein the two-dimensional contour line is displayed so as to be superimposed on the fundus image of the eye to be inspected. 8. The projection optical system sequentially comprises an objective auxiliary lens, the objective lens, a beam splitter, and a pinhole, and the light receiving optical system relates to the objective auxiliary lens, the objective lens, and the beam splitter. A second aperture stop arranged substantially conjugate, and a projection lens arranged so that the second aperture stop is located at a front focal position, and the light receiving optical system is an afocal optical system. The ophthalmic measurement device according to claim 1. 9. The predetermined part of the subject's eye is an anterior segment,
The projection optical system sequentially includes an objective auxiliary lens, the objective lens, a beam splitter, and an aperture stop, and the light receiving optical system is arranged in a substantially conjugate manner with respect to the objective auxiliary lens, the objective lens, and the beam splitter. Aperture stop and a projection lens arranged so that the second aperture stop is located at the front focal position, the light receiving optical system is an afocal optical system, and the objective lens of the objective auxiliary lens is The ophthalmologic measuring apparatus according to claim 1, wherein the side focal plane and the light receiving unit are substantially conjugate with each other.