KR20250058296A - pin hole article for scanning laser ophthalmoscope - Google Patents

Abstract

A pinhole body for a scanning laser ophthalmoscope that eliminates unnecessary scattered light from the eye and optical system is disclosed.
The present invention comprises a scanning laser ophthalmoscope comprising a diopter lens (34) for focusing laser light by correcting the diopter according to the subject's eye, a relay lens (36) for transmitting the focused laser light, and an objective lens (38) for forming a focus of the transmitted laser light on the retina of the subject's eye, wherein a conical pinhole body (40) having a conical wall surface (44) converging toward a pinhole (42) is installed between the relay lens (36) and the diopter lens (34) to remove laser reflection light generated from the objective lens (38).

Description

Pin hole article for scanning laser ophthalmoscope

The present invention relates to a pinhole body for a scanning laser ophthalmoscope, and more particularly, to a pinhole body for a scanning laser ophthalmoscope that eliminates unnecessary scattered light from an eye to be examined and an optical system.

A scanning laser ophthalmoscope (SLO) is an examination device that projects laser light emitted from a light source onto an object of examination, such as the fundus of the eye, and detects the reflected light reflected from the fundus to obtain an image of the fundus. Fundus examination is useful not only in ophthalmology but also in internal medicine for diagnosing hypertension, diabetes, and neurological diseases. It is widely known to image the retina of a subject with a scanning laser ophthalmoscope (SLO) to obtain retinal images at multiple wavelengths, where a specific wavelength represents a specific layer of the retina.

Fig. 1 is a drawing showing the overall configuration of a conventional scanning laser ophthalmoscope. As shown in Fig. 1, in a conventional scanning laser ophthalmoscope, laser light is generated from a laser light source (10), and the generated laser light passes through a beam splitter (14) and is reflected by a reflective mirror (16a, 16b) and incident on the retina of the subject's eye (5). At this time, a reflective mirror (16a, 16b) that is rotationally driven by a galvanometer changes the reflection angle of the laser light so that the laser light is irradiated to a desired measurement position on the retina, thereby scanning the observation area of the retina.

The reflected light reflected from the retina of the eye to be examined (5) travels in the opposite direction of the incident light, is reflected from the reflecting mirror (16a, 16b) and the beam splitter (14), passes through a pinhole (18) that functions as a confocal slit, and is then detected by the light detection unit (20). In the optical system of the scanning laser ophthalmoscope, a plurality of lenses (12a, 12b, 12c) are used to transmit the laser light generated from the laser light source (10) to the retina and transmit the laser light reflected from the retina to the light detection unit (20).

In addition, for example, a hole mirror having a hole (14a) formed in the center is used as the beam splitter (14). Therefore, very strong reflected light reflected from the apex of the lens (12a) does not pass through the hole (14a) in the center of the beam splitter (14) and does not proceed to the light detection unit (20), and only weak retinal image reflected light passing through the edge of the lens (12a) is reflected from the edge of the beam splitter (14), i.e., the hole mirror, and proceeds to the light detection unit (20).

FIG. 2 is a drawing showing an example of a conventional scanning laser optometry optical system. As illustrated in FIG. 2, a conventional scanning laser optometry optical system includes a laser light source (10) that generates laser light, one or more optical elements that transmit laser reflected light formed by reflecting off a retina (7, retina) of an eye to be examined (5) to a light detection unit (not illustrated in FIG. 2), and a pinhole (18) mounted in front of the light detection unit to suppress noise such as unnecessary scattered light generated from the eye to be examined (5) and the optical elements from entering the light detection unit.

For example, the optical element may include a collimation lens (32) that converts laser light into parallel light, a diopter lens (34) that focuses the laser light by correcting the diopter according to the subject eye, a relay lens (36) that transmits the focused laser light, an objective lens (38) that forms a focus of the transmitted laser light on the retina (7) of the subject eye (5), a beam splitter (14) that transmits the laser reflected light formed by reflecting off the retina (7) of the subject eye (5) to a light detection unit, etc. The beam splitter (14) is for separating the laser light incident on the retina (7) and the laser light reflected off the retina (7), and a conventional light separation means such as a dichroic mirror and a hole (perforated) mirror having a hole formed in the center may be used.

However, since it is difficult to sufficiently remove noise using only the conventional confocal pinhole (18), there is a problem in which the laser reflected light generated from the objective lens (38) overlaps with the retinal signal to be measured and affects the measurement.

In addition, there is a problem that additional noise occurs depending on the diopter change of the diopter lens.

Korean Patent Publication No. 10-2023-0087018 Japanese Patent Publication JP2016123477A Japanese Patent Publication JP2019118652A European Patent Publication EP3235421A1

An object of the present invention is to provide a pinhole body for a scanning laser ophthalmoscope that removes laser reflection light generated from an objective lens of the scanning laser ophthalmoscope.

Another object of the present invention is to provide a pinhole body for a scanning laser ophthalmoscope capable of removing noise without affecting a retinal signal to be measured even when the diopter of the eye to be examined changes in the scanning laser ophthalmoscope.

The present invention relates to a scanning laser ophthalmoscope comprising a diopter lens for focusing laser light by correcting diopter according to an eye to be examined, a relay lens for transmitting the focused laser light, and an objective lens for forming a focus of the transmitted laser light on the retina of the eye to be examined, wherein a conical pinhole body having a conical wall surface converging toward a pinhole is installed between the relay lens and the diopter lens to remove laser reflection light generated from the objective lens.

According to the present invention, by additionally installing a conical pinhole between a diopter lens and a relay lens, the laser reflection light generated from the objective lens of a scanning laser ophthalmoscope can be removed, thereby improving the accuracy of measurement.

In addition, it can effectively remove additional noise that occurs as the diopter changes.

Figure 1 is a drawing showing the overall configuration of a conventional scanning laser ophthalmoscope.
Figure 2 is a drawing showing an example of a conventional scanning laser ophthalmology optical system.
FIGS. 3a and 3b are drawings and enlarged drawings thereof, respectively, for explaining the installation position and function of a pinhole body for a scanning laser ophthalmoscope of the present invention.
FIGS. 4A and 4B are drawings showing examples of pinhole bodies for scanning laser ophthalmoscopy according to the present invention, respectively.
FIG. 5 is a drawing for exemplarily explaining a pinhole body and diopter lens structure for a scanning laser ophthalmoscope of the present invention.
Figures 6a and 6b are drawings and enlarged drawings thereof, respectively, for explaining the state of positional movement of the pinhole body and diopter lens structure according to changes in diopter.
FIG. 7 is a drawing for explaining a formula for determining the diagonal angle of a conical wall surface in a pinhole body for a scanning laser ophthalmoscope of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings, and elements that perform the same or similar functions as those in the prior art are given the same drawing reference numerals.

FIG. 3a and FIG. 3b are drawings and enlarged drawings thereof, respectively, for explaining the installation position and function of the pinhole body for the scanning laser ophthalmoscope of the present invention. As shown in FIG. 3, the pinhole body (40) of the present invention is installed between the diopter lens (34) and the relay lens (36) in addition to the existing confocal pinhole (18) arranged in front of the light detection unit (20).

The pinhole body (40) of the present invention removes unnecessary laser reflection light generated from the objective lens (38) and transmitted to the relay lens (36) and allows only the retinal signal to be measured to pass through.

FIG. 4A and FIG. 4B are drawings showing examples of pinhole bodies for scanning laser ophthalmoscopy according to the present invention, respectively. First, as shown in FIG. 4A, the present invention adopts a conical pinhole body (40) having a conical wall surface (44) converging toward a pinhole (42) instead of a conventional vertical flat pinhole (18) in order to efficiently remove laser reflection light generated from an objective lens (38) so that the focus of the measuring laser light is formed on the retina (7) of the subject's eye (5).

In the case of a vertical flat pinhole, the laser reflection light generated from the objective lens (38) is reflected from the flat surface by the mirror effect and returns to the light detection unit again, whereas in the case of the conical pinhole body (40) of the present invention, as can be seen in FIG. 3b, the laser reflection light is completely removed from the conical wall surface (44) and only the retinal signal to be measured passes through the pinhole (42).

Reference number 46 indicates a vertical wall surface facing the diopter lens (34) in the conical pinhole body (40). As shown in FIG. 4b, if even the wall surface facing the diopter lens (34) is formed as a conical wall surface (48) that converges toward the pinhole (42), even the laser reflection light returning through the diopter lens (34) can be removed. The conical pinhole body (40) can be made of a metal material, for example, aluminum material or plastic material.

The diameter of the pinhole is within 1 mm, preferably 0.1 mm to 0.3 mm.

FIG. 5 is a drawing for exemplarily explaining a pinhole body and a diopter lens structure for a scanning laser ophthalmoscope of the present invention. As illustrated in FIG. 5, the pinhole body and diopter lens structure of the present invention may be composed of a barrel (50), a diopter lens (34) fixedly installed on one side of the barrel (50), and a conical pinhole body (40) fixedly installed at a focal length on the other side of the barrel (50).

FIG. 6A and FIG. 6B are drawings and enlarged drawings thereof, respectively, for explaining the state of positional movement of a pinhole body and a diopter lens structure according to a change in diopter. As illustrated in FIG. 6, the conical pinhole body (40) and the diopter lens (34) of the present invention are fixed to a barrel (50) with the focal lengths adjusted and move together. For example, when 0D (diopter) is a reference position, they move to the left in the case of +D, and when -D, they move to the right. By doing so, even if the diopter changes depending on the eye to be examined, the laser reflection light can be effectively removed without affecting the original signal.

Meanwhile, the position movement of the shaft (50) can be performed via a motor that is not shown.

FIG. 7 is a drawing for explaining a formula for determining the oblique angle of a conical wall surface in a pinhole body for a scanning laser ophthalmoscope of the present invention. As shown in FIG. 7, the oblique angle (θ) of the conical wall surface (44) follows the numerical aperture (NA) of the diopter lens (34) as in the following mathematical formula 1 so that only the retinal signal to be measured passes through the conical pinhole body (40).

f: focal length of the diopter lens,

D; diameter of beam,

n: refractive index (air) = 1,

θ: angle of light

According to the present invention, by additionally installing a conical pinhole body (40) between the diopter lens (34) and the relay lens (36), the laser reflection light generated from the objective lens (38) of the scanning laser ophthalmoscope can be removed, thereby improving the accuracy of measurement.

In addition, it can effectively remove additional noise that occurs as the diopter changes.

Although the present invention has been described with reference to the above exemplary embodiments, the present invention is not limited to the above-described embodiments.

The scope of the following claims should be interpreted to encompass all modifications, equivalent structures, and functions of the exemplary embodiments.

Claims (5)

In a scanning laser ophthalmoscope, which includes a diopter lens (34) that focuses laser light by correcting the diopter according to the subject's eye, a relay lens (36) that transmits the focused laser light, and an objective lens (38) that causes the focus of the transmitted laser light to be formed on the retina of the subject's eye,
A pinhole body for a scanning laser ophthalmoscope, which is composed of a conical pinhole body (40) having a conical wall surface (44) converging toward a pinhole (42) to remove laser reflection light generated from an objective lens (38), and is installed between a relay lens (36) and a diopter lens (34). In claim 1,
A pinhole body for a scanning laser ophthalmoscope, having a conical pinhole (42) and conical walls (44) and (48) on both sides thereof. In claim 1,
A pinhole body for a scanning laser ophthalmoscope, wherein the conical pinhole body is fixedly installed at a focal length of the other side of a diopter lens (34) fixedly installed on one side of a barrel (50) and moves together with the diopter lens (34). In claim 1,
A pinhole body for a scanning laser ophthalmoscope, wherein the diameter of the pinhole (42) of the conical pinhole body is 0.1 mm to 0.3 mm. In any one of claims 1 to 4,
The oblique angle (θ) of the conical wall surface (44) of the conical pinhole body is
NA = n * sin θ = f / D, where,
f: focal length of the diopter lens,
D; diameter of beam,
n: refractive index (air) = 1,
θ: Pinhole body for a scanning laser ophthalmoscope, where θ is the angle of light.

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