JP2000023916A - Eye examination instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine the range and part of the fundus oculi to be photographed, without observing the fundus oculi on the basis of an image of the anterior part of the eye. SOLUTION: Light beams from a fixation target 10 are reflected by an optical-path selecting double-sided mirror 6, transmitted through an optical path switching mirror 3, and projected via an objective lens 1 onto the eye E to be examined. An anterior eye light beam illuminated by an infrared light source 2 is reflected by the optical path switching mirror 3 after passing through the objective lens 1, then passes through a mirror 11, a lens 12, and a mirror 13, is reflected by the optical-path switching double-sided mirror 6, and picked up as an image of the anterior part of the eye by an image pickup means 7. Signals from the image pickup means 7 are inputted to a computing means 8 and the center position of a pupil image and the position of a corneal reflex image formed by the infrared light source 2 are computed. A diagram K of the fundus oculi is displayed on a television monitor 9 according to the direction of the visual axis calculated. The position of the fixation target 10 is also displayed on the television monitor 9 as a mark M. When the subject views the fixation target 10, the macula B coincides with the mark M. The subject moves the fixation target 10 while watching the television monitor 9 to adjust the photographic range of the fundus oculi that enters a photographic frame S.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optometry apparatus such as a fundus camera and an auto-refractometer having a photoelectric detection technique.

[0002]

2. Description of the Related Art For example, Japanese Patent Application Laid-Open Nos. 2-185228 and 4-341078 disclose a technique for detecting a line-of-sight direction based on a relative positional relationship between a corneal reflection and a pupil.

[0003] In a fundus camera, the photographing range of the fundus is determined by observing the fundus, and in an optometric measurement device such as an auto-refractometer or an auto-keratometer, measurement is performed by instructing to look at a fixation target. I have.

[0004]

However, at the time of optometry,
There is a problem that the examiner does not know which direction the eye to be examined actually looks.

An object of the present invention is to enable a fundus camera to determine a photographing range or a part of the fundus without observing the fundus, and to allow a subject to measure in a predetermined direction in an optometric measurement with high accuracy. Or an optometry apparatus that allows the user to know later in which direction the measurement has been made.

[0006]

The optometry apparatus according to the present invention for achieving the above object has an anterior segment imaging means for imaging the anterior segment of the eye to be examined and an optometry unit for examining the subject eye. The optometry part of the optometry part is detected based on a signal from the anterior eye part imaging part.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 shows a first embodiment, which shows a non-mydriatic retinal camera. On an optical path O1, which is a fundus imaging optical path, an objective lens 1, an infrared light source 2 provided on both sides of the objective lens 1, an optical path switching mirror 3 that transmits visible light, a fundus illumination light and a photographing light from the eye E side. Mirror 4, a fundus photographing optical system 5, an optical path switching double-sided mirror 6,
An imaging means 7 having sensitivity to infrared light and visible light is sequentially provided. The output of the imaging means 7 is connected to a television monitor 9 via a calculation means 8, and a signal is transmitted from the calculation means 8 to the fixation target 10.

An anterior segment imaging optical path is provided by an optical path O2 in the reflection direction of the optical path switching mirror 3, and a mirror 11, a lens 1
2. The optical path is switched to the double-sided mirror 6 via the mirror 13. In the direction of incidence of the half mirror 4, a lens 14 and a light source 15 composed of a strobe for illuminating the fundus at the time of photographing are arranged.

A photographing position is determined prior to fundus photographing. In this case, the optical path switching mirrors 3 and 6 are lowered to the position shown in FIG. The light beam from the fixation target 10 is reflected by the optical path switching double-sided mirror 6, passes through the optical path switching mirror 3, and is projected onto the eye E through the objective lens 1. The position of the fixation target 10 can be adjusted by the examiner within the imaging range, and adjusts the imaging position of the fundus of the eye E to be inspected.

The anterior segment light beam illuminated by the infrared light source 2 is reflected by the optical path switching mirror 3 after passing through the objective lens 1, passes through the mirror 11, the lens 12, and the mirror 13 and is reflected by the optical path switching double-sided mirror 6. FIG.
Are taken as an anterior segment image E ′ as shown in FIG. The signal from the imaging means 7 is input to the calculating means 8 and the center position of the pupil image P 'and the position of the corneal reflection image C' of the infrared light source 2 are calculated.

A method of obtaining the line-of-sight direction based on the positional relationship between the pupil image P 'and the corneal reflection image C' is disclosed in, for example, Japanese Patent Laid-Open No. 4-341.
No. 078. The fundus graphic K such that the macular portion comes in the calculated line of sight is displayed on the television monitor 9. On the other hand, the position of the fixation target 10 is also displayed as a mark M on the television monitor 9. If the subject is looking at the fixation target 10, the macula B matches the mark M. As shown in FIG. 1, if the user is away from the camera, it can be understood that the user is not watching, and the user is instructed to watch. The examiner moves the fixation target 10 while watching the television monitor 9 and adjusts so that a desired fundus range is included in the photographing frame S.

Note that a fundus still image stored in the calculating means 8 may be displayed in accordance with the line of sight, instead of the fundus graphic K by computer graphics. The range of the fundus graphic K displayed in the photographing frame S is determined by the viewing direction and the photographing angle of view. If the line of sight is in the optical path O1 direction, the macular B
Is displayed.

If the line of sight is inclined to the nose side by 15 degrees, a fundus figure K centering on the nipple is displayed. Since the fundus graphic differs depending on the left and right eyes E, it is detected in advance, or the examiner inputs the fundus graphic K so that the left and right of the fundus graphic K are determined and displayed. The examiner can see the fundus figure K on the television monitor 9 to know the photographing position and range, and can confirm the photographing range without a fundus observation system. The photographing range can be determined without observing the fundus, the configuration is simplified, and the position of the fixation index 10 can be adjusted with a fundus camera that photographs while looking at the anterior ocular segment.

After the fixation of the fixation target 10, the anterior eye image E 'picked up by the image pickup means 7 is displayed on the television monitor 9, the position is focused, and the photographing shutter is pressed. At the time of photographing, the optical path switching mirrors 3 and 6 are raised in the direction of the arrow, the strobe 9 is emitted, and the fundus image is photographed by the photographing means 7. The fixation target 10 may be shown to the other eye instead of the eye E to be examined as in a mydriatic retinal camera.
In that case, the position of the mark M is not known, so that it is not displayed. The examiner can understand the imaging region without looking at the fundus image, and can adjust the position of the external fixation lamp by looking at the fundus graphic K.

FIG. 3 shows a second embodiment, which is an optometry apparatus such as an auto-refractometer or an auto-keratometer. An objective lens 21 is provided on the optical path O3 in front of the subject's eye E,
An infrared light source 2, a light splitting member 22 that reflects infrared light, a light splitting member 23 that reflects visible light, and an optometry measurement system 24 are sequentially arranged. A lens 25 and an imaging unit 26 are arranged in the reflection direction of the light splitting member 22, and an output of the imaging unit 26 is connected to an arithmetic unit 27, and an output of the arithmetic unit 27 is connected to a microphone 28. . Further, the light splitting member 2
A lens 29 and a fixation target 30 are provided in the direction of incidence 3.

A light beam is projected from the optometry measurement system 24 to the eye E, and the reflected light is photoelectrically detected for measurement. The luminous flux from the fixation target 30 is reflected by the light splitting member 23 that reflects visible light via the lens 29 and is projected to the eye E. The luminous flux from the anterior segment is formed on the image pickup means 26 via the objective lens 21, the light splitting member 22 for reflecting the wavelength light of the light source 2, and the lens 25 as shown in FIG. 'And the corneal reflection image C' of the light source 2 are shown.

The anterior segment image signal of the imaging means 26 is calculated by the arithmetic means 2
7, and the relative position between the center position of the pupil image P ′ and the intermediate position of the corneal reflection image C ′ is calculated. From this positional relationship, it is determined whether the eye E is looking at the fixation target 30 at the center of the optical path O1. When the eye E is looking in the optical path O3 direction, an intermediate position of the corneal reflection image C 'is generated on the nose side of the pupil image P' by 0.5 mm. If the line of sight is not directed in that direction, the position is shifted, and if the amount of the shift affects the measured value, a synthesized voice is issued from the microphone 28 saying “look at the target”. The measurement can be performed accurately even with an automatic device that does not require a user.

In a device operated by the examiner while looking at the anterior eye display monitor, a warning is displayed on the monitor to notify the monitor that the visual line is deviated by a certain amount or more, instead of the sound from the microphone 28. Note that the direction of the line of sight corresponds to the position on the fundus, and if the line of sight is in the direction of the optical path O3, the measurement will be performed at the center of the macula B of the fundus, and accurate measurement can be performed.

In a measuring device or a photographing device for the cornea C, the line of sight corresponds to a measuring position or a photographing position on the cornea. Therefore, at the time of measurement or photographing, the corneal position is calculated from the anterior eye image at that time.
The position on the cornea is recorded in correspondence with the measured value or the photographed image. If the measured values and the captured images correspond to the fundus and cornea position of the eye E, better diagnostic information can be provided.

[0020]

As described above, the optometry apparatus according to the present invention can detect an optometry site based on an anterior segment image obtained by anterior segment imaging means.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a fundus camera according to a first embodiment.

FIG. 2 is an explanatory diagram of an image on an imaging unit.

FIG. 3 is a configuration diagram of an optometry apparatus according to a second embodiment;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Objective lens 2 Infrared ray 3 Optical path switching mirror 6 Optical path switching double-sided mirror 7, 26 Imaging means 8, 27 Calculation means 9 TV monitor 10, 30 Fixation target 24 Optometry measuring system 28 Microphone

Claims (3)

[Claims] 1. An optometry unit for imaging an anterior segment of an eye to be examined, and an optometry unit for examining the eye to be examined, and an optometry unit of the optometry unit based on a signal from the anterior segment imaging unit. An optometry apparatus for detecting an eye. 2. The optometry apparatus according to claim 1, wherein the optometry unit is a fundus photographing unit, and the optometry site is a fundus. 3. The optometry apparatus according to claim 1, wherein the optometry unit is an optometry unit, and the optometry site is a fundus or a cornea.