KR101457479B1 - Ophthalmoscope - Google Patents

Abstract

The present invention provides an ophthalmoscope which includes the following: an eyepiece which is to observe the eye of an examinee; an object lens which is placed at the eye side of the examinee to be placed on the same axis with the eyepiece and makes an image to be formed on the eye of the examinee; a relay lens which is placed between the eye piece and the object lens and reverses the image reversed by the object lens; and a lighting unit which emits light to observe the eye-ground of the examinee. The eye-relief of the ophthalmoscope is between 25 and 27.5mm, and the ophthalmoscope meets the formula below. In the formula, fe is the focal distance of the eye piece, R the eye-relief, fr the focal distance of the relay lens, d1 the distance between the facing main points between the object lens and relay lens, and d2 the distance between the facing main points between the relay lens and eyepiece. According to the present invention, when an observer examines the eyes of the examinee, the observer can wear glasses so inconvenience of the observer can be removed. Also, by securing the distance between the eyes of the observer and the eyepiece, the eyepiece can be protected against external contact, and contamination of and damage to the eyepiece due to contact can be prevented.

Description

Ophthalmoscope

The present invention relates to an ophthalmoscope, and more particularly, to an ophthalmoscope that enables wearing of glasses when an observer inspects an eye of an examinee and protects the eyepiece from external contact.

In general, an ophthalmoscope includes instruments used for various examinations of an eye to be examined, including instruments used for observing and refracting an eye fundus, a vitreous body and a lens of a subject's eye, for examining nearsightedness or primordial state.

Prior art related to such an ophthalmoscope is disclosed in U.S. Patent No. 7784940, entitled " Eye Capture Optics ", which includes a portable housing having an observer end and a patient end; An illumination system including a light source disposed in the portable housing and an objective lens crossing the imaging axis; An image system at least partially disposed in the portable housing; An eyepiece for facilitating direct viewing of the retina; An electronic image sensor for generating an image signal; A display supported by the portable housing and connected to the electronic image sensor; An aperture diaphragm disposed in the imaging axis; And one of a pair of focal planes substantially coinciding with a position of the electronic image sensor and the other of the pair of focal planes is defined in front of an eyepiece lens And a beam splitter crossing the imaging axis of the apparatus.

Other prior arts include the " eye viewing device comprising eye cup "of U.S. Patent No. 6,830,347 and the" focusing mechanism "of U.S. Patent No. 6,390,625.

Since the conventional ophthalmoscope has an eye relief of 15 mm or less, it is impossible for the observer to examine the eyeglasses while wearing the glasses, and the observer's eye and the eyepiece are close to each other, The eyepiece can not be protected from contact. This problem causes the observer to remove the glasses from time to time whenever observing the fundus of the subject using the ophthalmoscope, which increases the inconvenience of the observer and causes the eyepiece to be contaminated or damaged by contact with the outside .

SUMMARY OF THE INVENTION In order to solve the problems of the prior art as described above, the present invention solves the inconvenience of the observer by making it possible for the observer to wear the glasses when inspecting the eye of the examinee, Thereby protecting the eyepiece from external contact.

Other objects of the present invention will become readily apparent from the following description of the embodiments.

According to an aspect of the present invention, there is provided an eyepiece comprising: an ocular lens positioned at an eye side of an observer for observing an eye of a subject; An objective lens positioned on the eye side of the subject so as to be located on the same axis as the eyepiece lens and forming an image on the eye side of the subject; A relay lens positioned between the eyepiece lens and the objective lens and reversing the image reversed by the objective lens; And an illumination unit for irradiating light for observing a fundus of a subject, wherein the eyelash (R) is 25 to 27.5 mm and satisfies the following equation (1).

[Equation 1]

Fr is the focal length of the relay lens, d1 is the distance between the opposing principal points between the objective lens and the relay lens, d2 is the distance between the relay lens and the eyepiece lens, It is the distance between the main points facing each other.

The ophthalmoscope can satisfy the following expression (2) while having a magnification (M) of 0.8 to 1.2x.

&Quot; (2) "

Here, M is the magnification, fo is the focal length of the objective lens, fe is the focal length of the eyepiece lens, and Mr is the magnification of the relay lens.

The eyepiece, the objective lens, and the relay lens may be arranged so as to satisfy the following equation (3).

&Quot; (3) "

100mm? (D1 + d2)? 200mm

Here, d1 is a distance between opposing principal points between the objective lens and the relay lens, and d2 is a distance between opposing principal points between the relay lens and the eyepiece lens.

The focal length of the eyepiece is 20 to 30 mm, the focal length of the relay lens is 15 to 25 mm, and the focal length of the objective lens is 20 to 30 mm.

The illumination unit includes: an LED for emitting light in a direction perpendicular to the axis; An LED lens positioned in front of the LED and focusing light of the LED; And a beam splitter positioned between the relay lens and the objective lens on the axis for partially reflecting the light focused by the LED lens and for transmitting the light to the examinee's fundus.

According to the ophthalmoscope according to the present invention, since the ophthalmoscope has an eyelid in a range of 25 to 27.5 mm, it is possible to wear the glasses when the observer inspects the eye of the subject, thereby solving the inconvenience of the observer , It is possible to secure the distance between the observer's eye and the eyepiece lens so as to protect the eyepiece lens from external contact, thereby preventing contamination or damage of the eyepiece lens due to the contact.

1 is a configuration diagram showing an ophthalmoscope according to an embodiment of the present invention.
Fig. 2 is a configuration diagram showing a main part of an ophthalmoscope according to one embodiment of the present invention.
3 and 4 are views for explaining the main points of the lens.
5 is a graph of MTF characteristics of an ophthalmoscope according to the prior art.
6 is a graph of MTF characteristics of an ophthalmoscope according to an embodiment of the present invention.

The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated and described in detail in the drawings. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but is to be understood to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention, And the scope of the present invention is not limited to the following examples.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings, wherein like or corresponding elements are denoted by the same reference numerals, and redundant explanations thereof will be omitted.

1 is a configuration diagram showing an ophthalmoscope according to an embodiment of the present invention.

1, an ophthalmoscope 100 according to one embodiment of the present invention includes an eyepiece 110, an objective lens 120, a relay lens 130, and an illumination unit 140 . The ophthalmologic apparatus 100 according to one embodiment of the present invention can be made portable and can be used as an ophthalmologic apparatus in which the eyes 1 of the observer and the eyes 2 of the examinee can be seen when observing the eyes 2 of the examinee with the eyes 1 of the observer. An eyepiece 110, a relay lens 130, and an objective lens 120 are arranged on the same axis in the longitudinal direction in the inner space so as to form a dark room inside the housing (not shown) And may be arranged so as to be sequentially arranged. At this time, the housing may be provided with a handle for an observer to grasp, and a space for installing the illumination unit 140 may be provided on the side.

The eyepiece 110 is located on the eye 1 side of the observer and observes the eye 2 of the examinee so as to be positioned close to the eye 1 of the observer and to observe the image of the eye 2 of the examinee .

The objective lens 120 is positioned close to the eye 2 side of the examinee so as to be positioned on the same axis as the eyepiece 110 and forms an image on the eye 2 side of the examinee.

The relay lens 130 is located between the eyepiece 110 and the objective lens 120 and reverses the image reversed by the objective lens 120 and forms another image from the image formed by the objective lens 120 .

Referring to FIG. 2, an ophthalmologic apparatus 100 (shown in FIG. 1) according to an embodiment of the present invention has an eyelash (R) of 25 to 27.5 mm and satisfies Equation 1 below. When the eye relief R is less than 25 mm, it is difficult for the observer to observe the eye 2 of the examinee in a state in which the observer wears the glasses. If the eye relief R exceeds 27.5 mm, It takes a long time to find it, which makes the test difficult.

[Equation 1]

Where fr is the focal length of the relay lens 130 and d1 is the distance between the objective lens 120 and the relay lens 130, D2 is the distance between the main points of the relay lens 130 and the eyepiece 110 facing each other. From Equation (1), it can be seen that the longer the focal length fe of the eyepiece 110, the longer the eye relief R becomes. The focal length of the objective lens 120 may have the same value when measured with respect to both sides, as well as the focal length of the eyepiece 110 and the focal length of the relay lens 130. The eye relief R is a distance from the main point on the observer's side to the cornea of the observer's eye 1 in the eyepiece 110. [

Referring to FIGS. 3 and 4, the main points will be described in detail. The lens has first and second principal points H1 and H2 on the object side and an image side respectively, wherein the first principal point H1 The intersection of the first main surface PP1 and the optical axis and the second main point H2 is the intersection of the second main surface PP2 and the optical axis. Here, the first main surface PP1 means a hypothetical surface which appears to be refracted from the image side, and the second main surface PP2 means a hypothetical surface which is viewed from the object side Means a hypothetical surface that appears to be refracted when viewed from the image side. The lens also has first and second focuses F1 and F2 where the first focus F1 is an axial object point at which an image is made at infinity and the second focus F2 is a store of an axial object point at infinity.

3 and 4, a first main point H1 is arranged on the left side of the lens and a second main point H1 is arranged on the right side of the lens, as shown in Fig. 3 and Fig. 4, The eye relief R is the distance from the second principal point H2 of the eyepiece 110 to the cornea of the observer's eye. D1 is the distance from the second main point H2 of the objective lens 120 to the first principal point H1 of the relay lens 130 and d2 is the distance between the second principal point H2 of the relay lens 130, To the first major surface (H1) of the eyepiece (130).

The ophthalmoscope 100 according to one embodiment of the present invention can satisfy the following equation (2) while having a magnification (M) of 0.8 to 1.2x, for example. If the magnification M deviates from the above range, it is difficult for an observer to observe the eye 2 of the examinee accurately, and designing of a housing or the like as a portable is not easy.

&Quot; (2) "

Here, M is the magnification, fo is the focal length of the objective lens 120, fe is the focal length of the eyepiece 110, and Mr is the magnification of the relay lens 130. When the focal distance fo of the objective lens 120 is 23.62 mm and the focal length fe of the eyepiece 110 is 25 mm and the magnification Mr of the relay lens 130 is 1.1 x, The magnification of the objective lens 100 becomes 1x.

The eyepiece 110, the objective lens 120, and the relay lens 130 may be arranged so as to satisfy the following equation (3).

&Quot; (3) "

100mm? (D1 + d2)? 200mm

Here, d1 is a distance between opposing principal points between the objective lens 120 and the relay lens 130, and d2 is a distance between opposing principal points between the relay lens 130 and the eyepiece lens 110. [ Here, d1 and d2 are as described above. By satisfying Equation (3), the ophthalmologic apparatus 100 according to the present invention not only can be used as a portable apparatus, but also easily satisfies a product standard for inspecting an eye 2 of a subject.

The focal distance fe of the eyepiece 110 is 20 to 30 mm and the focal distance fr of the relay lens 130 is 15 to 25 mm and the focal distance fo of the objective lens 120 is 15 to 25 mm. A space for the beam splitter 143 that enters between the objective lens 120 and the relay lens 130, the brightness of the appropriate light reaching the fundus of the subject, And height.

Referring to FIG. 1, the illumination unit 140 irradiates light for observing a fundus of a subject. For this purpose, the eyepiece 110, the relay lens 130, and the objective lens 120 An LED 141 for emitting light in a direction orthogonal to an axis passing through the center of the LED 141, an LED lens 142 positioned in front of the LED 141 for focusing the light of the LED 141, And a beam splitter 143 positioned between the relay lens 130 and the objective lens 120 on the axis in order to partially reflect the light focused by the objective lens 120 and to transmit the light to the fundus of the examinee. And can be installed in the interior space of the housing as described.

The LED 141 is operated by receiving power from an external power supply unit or a battery provided in the housing. The LED 141 may be turned on / off by an operation signal of an operation unit provided in the housing or the exterior thereof. Also, the LED lens 142 minimizes the loss of light by focusing the light emitted from the LED 141, for example, so that the height h of the retina in the eye 2 of the subject can reach 5.5 mm.

The operation of the ophthalmoscope according to the present invention will now be described.

FIG. 5 is a graph showing a modulation transfer function (MTF) characteristic of a panoptic of welch allyn, a US medical device specialist, and FIG. 6 is a graph showing the modulation transfer function (MTF) of an ophthalmoscope according to an embodiment of the present invention. function) characteristic. Here, the object height of the observer is 4.8 mm in the case of the prior art, whereas it is 5.5 mm in the case of the present invention. As described above, since the retina range of the observer is 4.8 mm, the chief ray deviates greatly from the optical system when the field height is higher than that of the optical system. Therefore, when observing the retina of the subject, At a height of 5.5 mm, the observation of the phase becomes very difficult. On the other hand, the present invention makes it possible to observe a sufficient image even when the retina range of the observable subject is 5.5 mm.

As shown in FIGS. 5 and 6, when the on-axis is 50 lp / mm, the present invention is 36.7%, whereas the prior art is 17.9%. In the off-axis 20 lp / mm, the present invention has 28.7% (field height: 4.8 mm) and 22% (field height: 5.5 mm), which is superior to the prior art 11.7% (field height: 4.8 mm) I have.

According to the present invention as described above, since the ophthalmoscope has an eyelier in a range of 25 to 27.5 mm, it is possible to wear the glasses when the observer inspects the eye of the examinee, thereby eliminating the inconvenience of the observer By securing a distance between the observer's eye and the eyepiece lens, the eyepiece lens is protected from external contact, thereby preventing contamination or damage of the eyepiece lens due to the contact.

Although the present invention has been described with reference to the accompanying drawings, it is to be understood that various changes and modifications may be made without departing from the spirit of the invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

1: Eye of the observer 2: Eye of the examinee
110: eyepiece lens 120: objective lens
130: relay lens 140: illuminator
141: LED 142: LED lens
143: beam splitter

Claims (5)

An eyepiece for observing the eye of the examinee, the eyepiece being located on the eye side of the observer;
An objective lens positioned on the eye side of the subject so as to be located on the same axis as the eyepiece lens and forming an image on the eye side of the subject;
A relay lens positioned between the eyepiece lens and the objective lens and reversing the image reversed by the objective lens; And
And an illumination unit for irradiating light for observing a fundus of a subject,
An eyepiece having an eyelash (R) of 25 to 27.5 mm and satisfying the following formula (1).
[Equation 1]

Fr is the focal length of the relay lens, d1 is the distance between the opposing principal points between the objective lens and the relay lens, d2 is the distance between the relay lens and the eyepiece lens, It is the distance between the main points facing each other. The method according to claim 1,
The ophthalmoscope comprises:
An ophthalmoscope having a magnification (M) of 0.8 to 1.2x and satisfying the following expression (2).
&Quot; (2) "

Here, M is the magnification, fo is the focal length of the objective lens, fe is the focal length of the eyepiece lens, and Mr is the magnification of the relay lens. The method according to claim 1,
Wherein the eyepiece lens, the objective lens,
(3): " (3) "
&Quot; (3) "
100mm? (D1 + d2)? 200mm
Here, d1 is a distance between opposing principal points between the objective lens and the relay lens, and d2 is a distance between opposing principal points between the relay lens and the eyepiece lens. The method according to any one of claims 1 to 3,
Wherein the focal length of the eyepiece is 20 to 30 mm, the focal length of the relay lens is 15 to 25 mm, and the focal length of the objective lens is 20 to 30 mm. The method according to claim 1,
The illumination unit includes:
An LED for emitting light in a direction orthogonal to the axis;
An LED lens positioned in front of the LED and focusing light of the LED; And
A beam splitter positioned between the relay lens and the objective lens on the axis for partially reflecting the light focused by the LED lens to the fundus of the examinee;
.

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