JPS6349130A - Subjective and objective refractometer - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an objective and subjective refractometer for subjectively or objectively determining the ultimate refractive power Δ11 in an eye clinic or the like.

[Prior Art] Conventionally, in this type of device, the subjective and objective test has been generally performed by projecting and presenting a visual target provided inside the device using an optical system. This method not only has a narrow viewing angle, but also the light flux at the pupil is small, so if the eye moves even slightly, it becomes impossible to see.
This has the disadvantage that the all-accuracy accuracy is relatively poor because the visual acuity differs from that seen when wearing glasses.

[Objective of the Invention] The object of the present invention is to improve the drawbacks of the conventional apparatus as described above, and to provide a subjective and objective refraction system with high W11 constant accuracy, which enables subjective and objective eye refraction measurements to be performed in a natural visual state. The aim is to provide a meter.

[Summary of the Invention] The gist of the present invention for achieving the above-mentioned object is to provide a variable focus optical member for fixing refraction Δ14 disposed immediately in front of the subject's eye, and a light beam disposed behind the variable focus optical member. A dividing member;
an objective refractometer having an optotype for subjective detection disposed in one optical path of the light dividing member, and a near-infrared television camera for observation disposed in the other optical path of the light dividing member; and the objective refractometer. and a movement mechanism for alignment that moves the light beam in a direction perpendicular to its optical axis, and performs subjective and objective refraction measurements via the light splitting member and the variable focus optical member. It is a total.

[Embodiments of the invention] The present invention will be explained in detail based on illustrated embodiments.

FIG. 1 shows an embodiment of the subjective and objective refractometer according to the present invention,
A variable focus optical member 1 is arranged facing the eye E to be examined, a light splitting member 2 and an optotype 3 for subjective detection are arranged on the optical axis 01 behind it, a variable focus optical member l, and a light splitting member 2. is supported by the housing 4. In the reflection direction of the light splitting member 2,
An objective refractometer 7 containing a measuring section 5 and a near-infrared observation camera 6 is arranged, and the objective refractometer 7 is mounted on the housing 4 via a moving mechanism 8. The variable focus optical member 1 is made of a transparent material such as silicon, and when its periphery is pressed with a metal ring 1a, the radius of the curve V changes and the focal length can be changed. For example, a guichroic mirror that reflects near-infrared light and transmits visible light is used.

By moving the objective refractometer 7 on the housing 4 using the moving mechanism 8, alignment can be performed and the distance can be kept unchanged. The eye E to be examined is a variable focus optical member 1
The visual target 3 in front is viewed through the light splitting member 2. In this case, the light splitting member 2 and the variable focus optical member 1 must be integrated with the five bodies 4, but the optotype 3 does not necessarily need to be installed within the apparatus.

Furthermore, a near-infrared illumination device such as a light emitting diode for the television camera 6 is provided at a suitable location between the eye E and the variable focus optical member 1, for example, on the metal ring 1a of the variable focus optical member 1 as shown. A light source 9 is provided. FIG. 2 shows a screen S captured by the television camera 6, where lb is the edge of the variable focus optical member 1, and EP is the pupil of the eye E to be examined.

In the case of a subjective test, alignment should be made so that the pupil Ep is approximately centered with respect to the edge 1b.
In the lateral direction perpendicular to the plane of the paper in FIG. Since it is large, there is no practical problem even if it is a little rough.

In an apparatus that performs a binocular subjective test, one variable focus optical member 1 is provided on each side, and the variable focus optical member 1 is configured to be moved laterally in order to match the pupil distance. Subjective refraction measurement is performed by changing the focal length of the variable focus optical member 1, and the distance between the eye E to be examined and the variable focus optical member 1 may be adjusted by looking at the gap from the side as in the past. The user may adjust the position of the forehead rest while looking at the screen S displayed by the camera 6.

Positioning for the objective test is carried out by moving the objective refractometer 7 over the body 4 using the moving mechanism 8 while looking at the screen S of the television camera 6, and placing a mark M at the center of the optical axis in the television camera 6.
Align it so that it reaches the center of the pupil EP. In objective measurement, since a small beam diameter is projected onto the eye E, alignment accuracy needs to be high. Therefore, if a sliding mechanism that moves on a guide rail is employed as the moving mechanism 8, alignment can be performed with considerably high accuracy.

Positioning in the optical axis 01 direction can be done by adjusting the forehead rest and moving the face relative to the device in the same way as in the case of the subjective test, so that the pupil Ep is aligned with the position on the screen S where it is not blurred. The near-infrared light is projected onto the fundus Er of the eye E through the light splitting member 2 and the variable focus optical member 1, and the reflected light is photoelectrically processed in the objective refractometer 7 to obtain an objective refraction value. can get.

In the case of FIG. 1, the optical axis 02 from the measurement unit 5 to the light splitting member 2 in the case of objective measurement is slightly inclined with respect to the optical axis 01 in order to remove the light reflected by the variable focus optical member 1. However, by matching these and replacing them with variable focus optical member 1.
Even if the variable focus optical member l is tilted, the reflected light from the variable focus optical member l can be removed.

Providing the near-infrared illumination light source 9 between the eye E to be examined and the variable focus optical member 1 is convenient because there is no reflection from the variable focus optical member 1, and since it is near-infrared light, it is not dazzling for the eye E to be examined. .

In the conventional case, the examiner confirms the center of the eye E by looking from the direction of the optical axis 01, which means that the examiner cannot confirm the center of the eye E during the measurement, but in the case of this embodiment, the examiner cannot confirm the center of the eye E during the measurement. For example, it is possible to monitor on the screen S of the television camera 6 whether the subject is squinting or not.

Note that the variable focus optical member 1 is shown as an example,
Alternatively, a structure in which lenses with different focal lengths are interchanged as usual may be used.

[Effects of the Invention] As explained above, the objective and objective refractometer according to the present invention can perform measurements in a natural visual state similar to when wearing glasses, and can perform alignment for objective measurements that require high precision. Because it can be carried out easily and reliably, it is possible to significantly improve measurement accuracy compared to conventional methods, and there is also the advantage that the condition of the eye to be examined can be monitored even during measurement.

[Brief explanation of the drawing]

The drawings show an embodiment of the subjective and objective refractometer according to the present invention, and FIG. 1 is an optical configuration diagram, and FIG. 2 is a front view of the screen of a television camera. 1 is a variable focus optical member, 2 is a light splitting member, 3 is an optotype, 4 is a rod body, 5 is a measurement unit, 6 is a television camera, 7 is an objective refractometer, 8 is a moving mechanism, and 9 is an illumination light source It is.

Claims (1)

[Claims] 1. A variable focus optical member for refractive measurement placed immediately in front of the subject's eye, a light splitting member placed behind the variable focus optical member, and a light splitting member placed in one optical path of the splitting member. an objective refractometer disposed in the other optical path of the light splitting member and having a near-infrared television camera for observation; and moving the objective refractometer in a direction perpendicular to its optical axis. What is claimed is: 1. A subjective and objective refractometer, comprising a moving mechanism for alignment, and performing subjective and objective refraction measurements via the light splitting member and the variable focus optical member. 2. The subjective and objective refractometer according to claim 1, wherein a near-infrared illumination light source is arranged in front of the variable focus optical member.