Optics: eye examining – vision testing and correcting – Eye examining or testing instrument – Objective type
Reexamination Certificate
2001-03-30
2004-03-16
Ruhl, Dennis W. (Department: 3737)
Optics: eye examining, vision testing and correcting
Eye examining or testing instrument
Objective type
Reexamination Certificate
active
06705728
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ophthalmologic apparatus such as a slit lamp microscope with a binocular stereomicroscope used in such as an observation or a photographing with respect to an eye to be examined, of a person to be examined.
2. Description of the Related Art
Generally, a stereomicroscope is applied to a wide area such as a medical field, an industrial field and the like. An object of its use is in an ophthalmologic field to finely perform an observation and an examination with respect to an eye of a person to be examined as well as to observe an eye and the like of a person to be examined, which is an observation object, with magnification. Thus, a stereomicroscope by which an examiner can observe and examine an eye of a person to be examined, in a comfortable position, is desired.
For example, a conventional binocular stereomicroscope used in a slit lamp microscope is constructed by, an objective lens unit, a variable power optical system unit for making variable power with respect to an observation light flux passed through the objective lens unit, an imaging lens for obtaining an observation image by imaging the observation light flux for which the variable power is made in a predetermined position, an erecting prism for erecting the observation image obtained by the imaging lens, and an eyepiece unit having an eyepiece.
Such a stereomicroscope has, for example, a fixed stereo angle of 13° approximately. By using the stereomicroscope, it is possible to perform a stereo view with the above fixed stereo angle for cornea, conjunctiva and front vitreous body (hereinafter refereed to as “front eye portion”) of a person to be examined. On the other hand, when retina and back vitrous body (hereinafter referred to as “eye fundus portion” of a person to be examined are examined, a lens is further provided. However, when a binocular field of view with a a stereo angle of 13° and such becomes is extremely narrow.
Also, according to a binocular stereomicroscope described in Japanese Patent Publication No. Hei 7-111507, a stereo angle converter with a rotatable optical main body is provided between an objective lens and a variable power converter corresponding to the above variable power optical system unit. A relative position of an optical axis of a partial light beam is shifted by the rotatable optical main body of the stereo angle converter to convert a stereo angle into other stereo angles, so that an eye front portion and an eye fundus portion of a person to be examined can be observed. That is, when the rotatable optical main body is rotated by, for example, 90°, the distance between the right and left optical paths (axes) of a partial light beam is short in a region between the optical main body and the objective lens. Thus, a stereo angle is made small by the rotation of the optical main body.
However, when an eye fundus of a person to be examined is observed, conventionally, an ophthalmoscope such as an erected microscope or an inverted microscope, an eye fundus camera, a slit lamp, a scan type laser apparatus or the like is used. The slit lamp is indispensable in an ophthalmic field, and is a commonly used instrument which may be referred to even as a stethoscope in ophthalmology. In particular, when a slit lamp microscope with a non-contact front lens is used, an observation of an eye fundus portion is extremely simplified. Also, a non-contact observation does not make a person to be examined uncomfortable. Thus, such an eye fundus observation is widely performed in a daily ophthalmic examination. Also, an optical property of the objective lens is extremely improved, and a following eye fundus portion observation of a person to be examined is performed by a slit lamp microscope with the front lens.
(1) The eye funds portion observation is carried out by operating the slit lamp microscope in such a manner as the front focus of the front lens is focused with the back focus of the objective lens of the slit lamp microscope while holding the front lens by the examiners hands.
(2) In stead of holding the front lens by hand, the front lens is held by a holding device for holding the front lens to perform the eye fundus portion observation.
However, in a conventional stereomicroscope, a microscope portion having, an objective lens unit, a variable power optical system unit, an imaging lens, an erecting lens and an eyepiece unit with an eyepiece, and a microscope arm portion for supporting the microscope portion are combined with each other, so that a stereo angle is fixed. When carrying out a stereoscopic observation of the eye funds portion, the field of view become narrow necessarily for observing either a front eye portion or an eye fundus portion of a person to be examined.
Also, in the above stereomicroscope described in Japanese Patent Publication No. Hei 7-111507, the rotatable optical main body of the stereo angle converter is rotated to convert a stereo angle into other stereo angle, so that an eye front portion and an eye fundus portion in a person to be examined can be observed. However, when the eye front portion and the eye fundus portion in the person to be examined are observed using this stereomicroscope, in order to obtain a stereo angle required in respective portions, it is necessary to rotate the optical main body by respective accurate rotation angles and then to hold it. If the optical main body cannot be accurately held with a rotation angle required to obtain a predetermined stereo angle for observing, for example, the front eye portion, of an eye of a person to be examined, a center of the field of view is shifted for observing the front eye portion of the person to be examined, so that inconvenience in observation of the front eye portion of the eye to be examined occurs. Also, since a slight shift in the rotation angle of the optical main body influences accuracy of an optical axis, it is difficult to adjust a rotation angle of the optical main body.
Furthermore, in the eye fundus portion observation with the above objective lens, this operation is complicated and is largely dependent on an experience of an examiner, so that the eye fundus portion observation takes a long time and a burden is imposed on an examiner and a person to be examined.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above circumstance, and an object of the present invention is to provide a binocular stereomicroscope in which a stereo angle converting unit having a stereo angle converting portion for performing a stereo angle conversion is provided, and which easily selects a predetermined stereo angle and can easily observe and examine a front eye portion and an eye fundus portion in a person to be examined by inserting or removing the stereo angle converting portion of the stereo angle converting unit onto or from the right and left optical axes if necessary.
By the way, when an ophthalmologic apparatus such as a slit lamp microscope having such a stereomicroscope is used, an arrangement position of the stereomicroscope in the case where the front eye portion of the eye to be examined is observed is different from that of the stereomicroscope in the case wherein the eye fundus portion is observed. Thus, when the stereo angle conversion is performed by the above stereo angle converting portion, it is necessary to move a frame in which the stereomicroscope is provided in a predetermined position. Here, an examiner observes an eye to be examined with respect to fifty persons or more per day in many cases. Thus, even if an adjustment operation time per person is short, a burden imposed on the examiner is increased in total.
Also, in the above ophthalmologic apparatus, for example, a halogen lamp is used as an illuminating light source for illuminating the eye to be examined. A color temperature of the reflection light (observation light) from the eye to be examined, illuminated by the halogen lamp, is suitable in the case where the front eye portion of the eye to be examined is observ
Kato Takeyuki
Ohno Masaki
Okamoto Tadashi
Wada Mitsuaki
Armstrong Kratz Quintos Hanson & Brooks, LLP
Kabushiki Kaisha Topcon
Ruhl Dennis W.
Sanders John R.
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