JP2925572B2 - Ophthalmic equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmologic apparatus that projects a light beam onto an eye to be inspected and inspects the eye from information on the reflected light.

[Prior art] Conventionally, in an ophthalmologic apparatus such as an automatic ocular refractometer or a non-mydriatic retinal camera, an anterior eye image of an eye to be inspected taken by a television camera is projected on a television monitor, and this is used for communication between the eye to be inspected and the apparatus. It is often used as a means for checking the quality of the alignment state or the suitability of the pupil diameter of the eye to be examined.

[Problems to be Solved by the Invention] However, conventionally, the alignment state, the pupil diameter, and the like are measured and measured by, for example, comparing the position and size of the projected pupil image with the index provided on the television monitor. The examiner must determine whether or not the imaging is appropriate. If the pupil diameter is smaller than the predetermined minimum diameter of the apparatus, measurement and imaging become difficult.

An object of the present invention is to easily adjust the pupil diameter of the subject's eye,
An object of the present invention is to provide an ophthalmologic apparatus capable of performing good measurement and imaging.

Means for Solving the Problems In order to achieve the above object, in an ophthalmologic apparatus according to the present invention, a fixation target for fixing the eye to be examined and an anterior segment image of the eye to be examined are photographed. An imaging optical system, a detecting unit for detecting a luminance distribution of an anterior eye image obtained by the imaging optical system, and an extracting unit for extracting a pupil image from the anterior eye image based on the luminance distribution obtained by the detecting unit Calculating means for calculating at least one of an area and a diameter of a pupil from a pupil image obtained by the extracting means; comparing means for comparing a calculation result of the calculating means with a predetermined value; Control means for controlling the amount of light reaching the subject's eye from the fixation target in response to the request.

[Operation] The ophthalmologic apparatus having the above configuration calculates the degree of the mydriasis and the position of the subject's eye based on the pupil image extracted from the anterior segment image. A signal for controlling the amount of light reaching the eye to be examined is reduced.

[Example] The present invention will be described in detail based on an illustrated example.

1 and 2 show the configuration of an automatic eye refractometer implemented in the present invention, FIG. 1 is a configuration diagram of an optical system, and FIG. 2 is a configuration diagram of an electric system. On the optical axis 01 along the axis of the eye E, a beam splitter 1, an objective lens 2, and a light from the left that divide the light from the left into straight light and downward polarized light from the eye E side. A measuring light source 7 including a perforated mirror 3 for reflecting downward, a relay lens 4, a chart 5, a condenser lens 6, an infrared light emitting diode, and the like is sequentially arranged. On the optical axis 02 deflected downward by the beam splitter 1, a beam splitter 8, a relay lens 9, a fixation chart 10, a fixation light source, which divides light from above into straight light and right-polarized light. The imaging lens 1 is arranged on an optical axis 03 which is arranged and further deflected by the beam splitter 8.
2. A beam splitter 13 having a division surface for reflecting light from above to the right, and an image sensor 14 composed of a CCD or the like are sequentially arranged. Further, on the optical axis 04 reflected downward by the perforated mirror 3, a multi-hole aperture 15, an imaging lens 1
6, a wedge prism 17 and a beam splitter 13 are provided.

In the above optical system, the measurement light source 7, the fixation chart 10
Is substantially conjugate with the fundus of the eye E, the chart 5, the multi-hole aperture 15 is substantially conjugate with the pupil, and the image plane of the image sensor 14 is an optical system of an optical path reflected by the objective lens 2 and the beam splitter 13. Is substantially conjugate with the fundus, and the optical system of the optical path reflected by the beam splitter 1 and the beam splitter 8 is configured to be located substantially conjugate with the pupil.
Note that the beam splitter 1 has a property of transmitting infrared light from the measurement light source 7 and reflecting visible light from the light source 11 for fixation, and the beam splitter 8 transmits light from the light source 11 for fixation. The beam splitter 13 has a characteristic.
It has the property of reflecting infrared light from The anterior segment of the subject's eye E is illuminated by a light source (not shown) or an extraneous light having an emission wavelength range different from that of the light source 11 for fixation, and the light having the wavelength by the illumination light is split by the beam splitter 1 and the beam splitter 8. And is transmitted through the beam splitter 13.

FIG. 2 is a configuration diagram of an electric system. The output of the image pickup device 14 is input to an image pickup device
The output of 21 is connected to one of the inputs of a comparator 22, and the output of the comparator 22 is connected to a common bus 23. The common bus 23 is an MPU 2 for controlling and calculating the entire device.
4, ROM25 and RAM26 where the control program is stored
Are connected to the D / A converter 27, the motor driver 28, the D / A converter 29, the input of the printer driver 30, and the measurement switch 31 which is turned on when the measurement is started.
Is connected. Further, the output of the D / A converter 27 is connected to the other side of the comparator 22, the output of the motor driver 28 is connected to the motor 32, and a power transmission device (not shown) is added to the motor 32. Ten
The fixation light source 11 is movable. On the other hand, the D / A converter 29 is connected to the fixation light source 11 via the light source driving circuit 33, and the printer driver 30 is connected to the printer.

In the above configuration, when the fixation light source 11 is turned on, the fixation chart 10 is illuminated. Since the fixation chart 10 is located at a position conjugate with the fundus, the light beam emitted from the fixation chart 10 forms an image on the fundus of the eye E through the relay lens 10, the beam splitter 8, and the beam splitter 1, so that the The examiner can fixate the image of the fixation chart 10.
The reflected light from the anterior segment image illuminated by a light source (not shown) is reflected by the beam splitter 1 and further by the beam splitter 8 and passes through an optical path passing through the beam splitter 13.
An image is formed on the image sensor 14 by the operation of the imaging lens 12. This image is converted into a television signal by the image sensor driving circuit 21, binarized by the comparator 22 by comparison with a value given from the MPU 24 via the D / A converter 29, and then converted to a RAM 26 via the common bus 23. Is stored in Here, if the comparison value given from the D / A converter 27 to the comparator 22 is appropriately selected, the pupil is darker than its surroundings, so the pupil image shown by oblique lines from the anterior eye image as shown in FIG. I will be extracted. In order to store the binarized data in the RAM 26, the output of the comparator 22 is stored in the corresponding memory address as it is, or the output of the comparator 22 is changed from 1 to 0 from the output of one frame of the comparator 22. A method of determining a changing position and a position changing from 0 to 1 and storing them may be used. The MPU 24 calculates the center position of the pupil based on the data stored in the RAM 26, and gives an examiner an instruction signal indicating in which direction the apparatus should be moved with respect to the eye E in accordance with the calculated position. MPU24 is RAM
The area of the pupil or the maximum diameter of the pupil is also calculated from the 26 data,
If this value is less than the preset value, D /
A signal is given to the light source driving circuit 33 via the A converter 29,
The light source driving circuit 33 lowers the luminance of the fixation light source 11 based on this signal. As a result, the fixation chart 10 becomes darker, mydriasis is promoted, and measurement can be performed. In addition, since the eye refractive power needs to be measured when the eye E is not performing adjustment, the pupil diameter or the area is continuously changed in time by utilizing the characteristic that the eye E undergoes miosis at the time of adjustment. If the measurement is performed automatically and the measurement is automatically performed when the mydriatic state is better, the measurement can be performed with less adjustment.

When the measurement light source 7 is turned on in the state where the adjustment of the apparatus has been completed by the above operation, a fundus reflection image is formed on the image sensor 14. That is, the infrared light beam emitted from the measurement light source 7 and passed through the chart 5 is projected onto the fundus of the eye E by the action of the objective lens 2, and the reflected light is once imaged by the objective lens 2 and reflected by the perforated mirror 3. 15 holes, wedge prism
The light beam is separated by 17 and re-images on the image sensor 14 by the operation of the imaging lens 16. The MPU 24 determines that the measurement has been started by the measurement switch 31 turned on at the same time as the lighting of the measurement light source 7, calculates the eye refractive power from the image obtained on the image sensor 14, and outputs the result via the printer driver 30. Printer
Output to 34.

In the above-described embodiment, when the pupil image I is extracted from the anterior segment image obtained on the image sensor 14, in addition to the method using the comparator 22, the A / D converter 27 uses a plurality of gradations. Alternatively, a method of obtaining an image having the following expression and recognizing the image based on the gradation level may be used. Further, in addition to instructing the examiner as described above, the device movement instruction signal transmitted in accordance with the calculated pupil position is input to a separately provided electric movement means and automatically performed, so that the examiner's The burden can be reduced, and accurate positioning can be performed in a short time.

FIG. 4 shows an embodiment in which the present invention is applied to a known fundus camera. The objective lens 41 is inserted into and removed from the eye E side along the optical axis 05 along the axis of the eye E. Flexible auxiliary lens 42, perforated mirror 43, relay lens 44, rotating optical axis
A movable mirror 45 and a photographic film 46 which can be inserted and removed in 05 are sequentially arranged. A field lens 47, a beam splitter 48, and a fixation lamp 49 are provided on the optical axis 06, which is deflected when the movable mirror 45 is inserted into the optical axis 05, and further deflected by the beam splitter 48. Optical axis 07
Above, an imaging relay lens 50 and an imaging element 51 are arranged. An illumination system (not shown) is provided on the optical axis reflected by the perforated mirror 43. The illumination system is configured so that the illumination light L is reflected by the perforated mirror 43 and travels toward the eye E to be inspected.

In the above-described optical system, when the relay lens 44 is adjusted in a state where the auxiliary lens 42 is inserted into the optical axis 05, the pupil of the eye E to be examined, the photographic film 46, and the imaging device 51 become conjugate, and the fixation lamp 49 The image forms on the fundus. Further, when the auxiliary lens 42 is retreated from the optical axis 05 while the relay lens 44 is kept in this state, the fundus of the eye E to be examined becomes a photographic film 46 and an image sensor 51.
And conjugate.

In the above configuration, the auxiliary lens 42 and the movable mirror 45 are inserted into the optical axis 05, and the subject is caused to fixate the fixation lamp 49. At this time, an anterior ocular segment image including a pupil is obtained on the image plane of the image sensor 51, and if this is processed in the same manner as in the previous embodiment, the alignment state and the pupil diameter can be adjusted. When the adjustment is completed, the shooting light source of the illumination optical system
By retreating the auxiliary lens 42 and the movable mirror 45 from the optical axis 05, a good fundus photograph can be obtained on the photographic film 46.

When the light source for illuminating the fixation target in each of the above embodiments is the fixation light source itself, that is, the fixation lamp itself, instead of changing the light amount of the fixation lamp according to the pupil diameter, fixation is performed. A filter, a diaphragm, or the like may be provided in an optical path from the viewing light source or the fixation lamp to the eye to be inspected, and the amount of light reaching the eye to be inspected E may be variable.

[Effects of the Invention] As described above, the ophthalmologic apparatus according to the present invention extracts a pupil image from an anterior ocular segment image, calculates the center position, area, and diameter of the pupil image, and gradually assembles them to predetermined values. Since the control signal is issued, the pupil diameter of the eye to be inspected can be easily adjusted, and accurate measurement and good ophthalmologic imaging can be performed.

[Brief description of the drawings]

FIG. 1 shows an embodiment of an ophthalmologic apparatus according to the present invention. FIG. 1 is a configuration diagram of an optical system of an automatic eye refractometer to which the present invention is applied.
FIG. 3 is a block diagram of an electric system, FIG. 3 is an explanatory diagram of an anterior segment image to be observed, and FIG. 4 is an optical block diagram of a fundus camera to which the present invention is applied. Reference numerals 1, 8, 13, and 48 are beam splitters, 3 is a perforated mirror, 5 is a chart, 7 is a measurement light source, 10 is a fixation chart, 11 is a fixation light source, 14 and 51 are imaging elements, and 15 is a large number. The aperture stop, 22 is a comparator, 23 is a common bath, 42 is an auxiliary lens, 46 is a photographic film, and 49 is a fixation light.

Claims (1)

(57) [Claims] 1. A fixation target for fixing an eye to be examined, an imaging optical system for photographing an anterior eye image of the eye to be inspected, and a luminance distribution of an anterior eye image obtained by the imaging optical system are detected. Detecting means, extracting means for extracting a pupil image from an anterior eye image based on the luminance distribution obtained by the detecting means, and calculating at least one of the area and diameter of the pupil from the pupil image obtained by the extracting means. Computing means, comparing means for comparing the computation result of the computing means with a predetermined value, and control means for controlling the amount of light reaching the subject's eye from the fixation target according to the comparison result by the comparing means. An ophthalmologic apparatus, characterized in that: