JP2022157210A - Illumination light source and ophthalmologic apparatus - Google Patents

Abstract

To provide an illumination light source and an ophthalmologic apparatus capable of illuminating a subject eye efficiently.SOLUTION: An illumination light source 22 in an ophthalmologic apparatus (a fundus camera 10) which irradiates a subject eye E with illumination light L comprises: a light emission part 100 for emitting the illumination light L; a cover 104 for covering the light emission part 100 therewith; and one or more translucent parts 106 provided at a position decentered from a center axis CA of the illumination light source 22 in the cover 104. The cover 104 emits the illumination light from only the translucent parts 106.SELECTED DRAWING: Figure 4

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination light source used in an ophthalmologic apparatus and an ophthalmic apparatus provided with this illumination light source.

BACKGROUND ART A fundus camera (ophthalmologic apparatus) for photographing the fundus of an eye to be examined is well known (see Patent Documents 1 and 2). This fundus camera includes an illumination system that irradiates the fundus of the subject's eye with various types of illumination light, and a light receiving system that captures (detects and receives) return light from the illumination area of the illumination light that has been applied to the fundus. The return light is light that returns from the illumination region of the fundus or a region near it, and includes reflected light of the illumination light, scattered light of the illumination light, fluorescence excited by the illumination light and its scattered light.

The illumination system of such a fundus camera is provided with an aperture (but not limited to this) that is optically conjugated or nearly conjugated to the cornea, iris, and posterior surface of the lens of the subject's eye. The diaphragm has, for example, a ring-shaped aperture, and prevents the reflected light of the illumination light reflected or scattered by the cornea and lens of the anterior segment of the subject's eye from entering the light receiving system (Patent Document 2 reference). This prevents noise light (flare, ghost, etc.) caused by reflection/scattering from the cornea, lens, etc. from being mixed into the captured image.

Japanese Patent No. 5735211 JP 2018-110691 A

FIG. 11 is an explanatory diagram for explaining a problem of a conventional illumination system. Note that FIG. 11 schematically illustrates an illumination system that includes an illumination light source 300, a diaphragm 302, and an optical system (not shown) and irradiates the fundus Ef with the illumination light L0 through the anterior segment Ea of the eye E to be examined. there is

As shown in FIG. 11, when the illumination light L0 emitted from the illumination light source 300 enters the diaphragm 302, part of the illumination light L0 passes through a ring-shaped opening 302a formed in the diaphragm 24. The illumination light L0 that does not pass through is shielded by the shielding portion 302b of the diaphragm 302. FIG. For this reason, part of the illumination light L0 emitted from the vicinity of the central axis CA (illumination optical axis) of the illumination light source 300 is blocked by the light blocking portion 302b, and is not used for illuminating the fundus oculi Ef. As a result, it is necessary to increase the amount of illumination light L0 emitted from the illumination light source 300 in order to ensure the necessary amount of illumination light L0 that irradiates the fundus oculi Ef, resulting in an increase in power consumption. Alternatively, if the illumination light source 300 does not have sufficient luminance, the effective amount of illumination light will be small. The photographing time becomes longer, the burden on the examinee increases, and the possibility of photographing failure due to the influence of the involuntary eye movement of the eye E to be examined increases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an illumination light source and an ophthalmic apparatus capable of efficiently illuminating an eye to be examined.

An illumination light source for achieving the object of the present invention is an illumination light source of an ophthalmologic apparatus that irradiates an eye to be inspected with illumination light. and one or a plurality of light-transmitting portions provided at positions decentered from the central axis of the illumination light source, and the cover emits illumination light only from the light-transmitting portions.

In the illumination light source according to another aspect of the present invention, at least a portion of the area different from the translucent portion in the outer surface or inner surface of the cover is a reflective surface.

In the illumination light source according to another aspect of the present invention, the translucent portion is formed in a pair of symmetrical slit-like shapes perpendicular to the central axis.

In the illumination light source according to another aspect of the present invention, the translucent portion is formed in a ring shape around the central axis.

An ophthalmic apparatus for achieving the objects of the present invention comprises the illumination light source described above.

An ophthalmologic apparatus according to another aspect of the present invention includes a diaphragm having a ring-shaped opening and through which illumination light emitted from an illumination light source passes.

The present invention can efficiently illuminate an eye to be examined.

1 is a schematic diagram of a fundus camera; FIG. It is a front view of a diaphragm. It is the front view which looked at the illumination light source from the diaphragm side. FIG. 4 is a cross-sectional view along line 4-4 of the illumination light source in FIG. 3; FIG. 4 is a cross-sectional view along line 4-4 of the illumination light source in FIG. 3; It is explanatory drawing which showed the modification of the shape of a translucent part. It is explanatory drawing which showed the modification of the light emission part. 1 is a schematic diagram showing an example of a normal fundus camera (including a multi-function device) that does not perform slit scan imaging; FIG. FIG. 9 is a front view of the diaphragm of the fundus camera shown in FIG. 8; FIG. 9 is an explanatory diagram showing an example of an illumination light source of the fundus camera shown in FIG. 8; It is an explanatory view for explaining a problem of a conventional illumination system.

[Overall Configuration of Fundus Camera]
FIG. 1 is a schematic diagram of a fundus camera 10 corresponding to the ophthalmologic apparatus of the present invention. As shown in FIG. 1, the fundus camera 10 is for photographing the fundus oculi Ef of the subject's eye E by a slit scan method (hereinafter referred to as slit scan photographing). a system 40;

The illumination system 20 irradiates a part of the fundus oculi Ef with illumination light LS (slit light) via an optical scanner 30 which will be described later. The illumination system 20 includes an illumination light source 22 , a diaphragm 24 , a slit aperture diaphragm 26 , an illumination system lens 28 , a lens 31 , an optical path dividing member 34 and an objective lens 38 . The diaphragm 24, the optical scanner 30, the optical path dividing member 34, and the anterior ocular segment Ea of the subject's eye E are in an optically conjugate relationship.

The illumination light source 22 emits illumination light L. As shown in FIG. Visible light is used as the illumination light L, but infrared light, which is light in the infrared region (including the near-infrared region) to which the subject's eye E has low sensitivity, may be used. A laser light source, an LED (Light Emitting Diode) light source, a white LED light source, a laser-excited white light source, or the like is used as the illumination light source 22, but is not limited thereto.

FIG. 2 is a front view of the diaphragm 24. FIG. As shown in FIG. 2 and FIG. 1 described above, the diaphragm 24 is in an optically conjugate relationship, or substantially in an optical conjugate relationship, with the cornea, iris, or posterior surface of the lens of the eye E to be inspected (e.g., an iris diaphragm). , lens front aperture, etc.), but not limited to this. The diaphragm 24 is perpendicular to and symmetrical with an illumination optical axis OB (the central axis CA of the illumination light source 22 described later, see FIG. 4), which is the optical axis from the illumination light source 22 of the illumination system 20 to the illumination system lens 28. It is a light shielding member having a pair of openings 24 a and prevents the illumination light LS, which will be described later, reflected by the anterior segment Ea (the front surface of the crystalline lens) from entering the light receiving system 40 . The illumination light L that has passed through the diaphragm 24 is incident on the slit aperture diaphragm 26 . Reference numeral 24b denotes a light blocking portion located inside the opening 24a (illumination optical axis OB side). Although not shown in FIG. 2, depending on the width of the light shielding portion 24b, a holding member for holding the light shielding portion 24b may be provided in the opening 24a portion.

The slit aperture diaphragm 26 generates illumination light LS from the illumination light L incident from the diaphragm 24 and emits the illumination light LS toward the illumination system lens 28 . The illumination light LS becomes a slit shape (slit light) parallel to the X direction at the fundus position and the fundus conjugate position at the time of focusing. The illumination light LS (slit light) is not particularly limited as long as it is perpendicular to the optical axis of the objective lens 38 (illumination system 20). The slit aperture diaphragm 26 is provided to be movable along the optical path of the illumination light LS by an actuator (not shown). By moving the slit aperture diaphragm 26, the illumination system 20 can be focused on the fundus oculi Ef.

The illumination system lens 28 emits the illumination light LS incident from the slit aperture stop 26 toward the optical scanner 30 . The optical path dividing member 34 and the objective lens 38 will be described later. The lens 31 emits the illumination light LS reflected by the optical scanner 30 toward the optical path dividing member 34 . The lens 31 brings the optical scanner 30 and the optical path splitter 34 into an optically conjugate relationship. The optical path dividing member 34 and the objective lens 38 will be described later.

A projector capable of emitting the illumination light LS may be used as the illumination system 20 . Examples of this projector include an LCD type projector, an LCOS (Liquid crystal on silicon) type projector using a reflective liquid crystal panel, and a projector using a DMD (Digital Mirror Device). In this case, instead of using a fixed mirror, the optical scanner 30 may mimic the optical scanning performed by the optical scanner 30 by changing the pattern of the projector.

The optical scanner 30 is a deflection mechanism capable of one-dimensional deflection (scanning) of the illumination light LS such as a galvanomirror, a resonant mirror, a polygon mirror, and MEMS (Micro Electro Mechanical Systems). It is arranged at the intersection with the optical axis of the lens 31 . The optical scanner 30 reflects the illumination light LS incident from the illumination system lens 28 toward the lens 31, and deflects the illumination light LS during slit scan imaging.

The optical path dividing member 34 reflects the illumination light LS incident from the lens 31 and emits it toward the objective lens 38, and also allows the return light LB (described later) incident from the objective lens 38 to pass through and toward the focusing optical system 36. emit. If the optical path splitting member 34 can split the illumination light LS and the return light LB, reflect the illumination light LS toward the objective lens 38, and emit the return light LB toward the focus optical system 36, Various splitters can be used.

The objective lens 38 irradiates the illumination light LS reflected by the optical path dividing member 34 through the anterior segment Ea (pupil) of the eye E to be examined and onto a part of the fundus oculi Ef. At this time, the illumination light LS is deflected by the optical scanner 30 described above, so that the inside of the fundus oculi Ef is scanned with the illumination light LS. While the illumination light LS is being deflected, the return light LB from the fundus Ef of the eye E irradiated with the illumination light LS enters the focusing optical system 36 through the objective lens 38 and the optical path dividing member 34. .

The light receiving system 40 includes an objective lens 38 , an optical path dividing member 34 , a focusing optical system 36 , a light receiving system lens 42 , and a CMOS type image sensor 44 .

The focus optical system 36 includes one or more lenses (focus lenses) movable along the optical path of the return light LB, and performs focus adjustment of the fundus camera 10 (light receiving system 40) under the control of the control device 18. . The focusing of the light receiving system 40 by the focusing optical system 36 and the focusing of the illumination system 20 by the slit aperture diaphragm 26 move in conjunction with each other according to the diopter (visibility) of the eye E to be examined. The return light LB that has entered the focus optical system 36 from the optical path dividing member 34 enters the light receiving system lens 42 . Note that instead of movably providing one or more focus lenses in the focus optical system 36, one or more variable focus lenses may be provided, and the method of focus adjustment is not particularly limited.

The light-receiving system lens 42 is composed of one or a plurality of lenses, and converges the return light LB incident from the focus optical system 36 onto the imaging device 44 .

The imaging element 44 has a light receiving surface 44a on which the return light LB from the light receiving system lens 42 is incident. It has a rolling shutter function that picks up (receives) the return light LB while shifting (see Patent Document 1). During slit scan imaging, the imaging element 44 is driven by a rolling shutter to pick up an image of the return light LB of the illumination light LS that moves within the fundus oculi Ef according to the deflection of the illumination light LS by the optical scanner 30 .

[Configuration of illumination light source]
FIG. 3 is a front view of the illumination light source 22 viewed from the diaphragm 24 side. FIG. 4 is a cross-sectional view along line 4-4 of the illumination light source 22 in FIG. FIG. 5 is a cross-sectional view of the illumination light source 22 along line 4-4 in FIG. 3, omitting illustration of the cover 104 in FIG. 4 to prevent complication of the drawing. As shown in FIGS. 3 to 5, the illumination light source 22 includes a central axis CA that coincides with the illumination optical axis OB, a light emitting section 100, lead wires 102, and a cover 104. As shown in FIG.

The light emitting unit 100 is a white LED, and includes an excitation light source 100a configured by the LED, a base 100b provided with the excitation light source 100a, and a light conversion material 100c containing phosphor. The excitation light source 100a is connected to the lead wire 102 via the bond wire BW, receives power from the lead wire 102, and emits excitation light (eg, blue light).

The base 100b has a holding hole for holding the excitation light source 100a. The excitation light source 100a is covered by a light conversion material 100c within the holding hole. The light conversion material 100c emits illumination light L, which is white light, by the phosphor emitting light (emitting red and green light) upon receiving excitation light from the excitation light source 100a.

The cover 104 is made of a transparent resin material or the like and has a substantially dome shape and is solid, and covers the front side of the light emitting section 100 (the emission side of the illumination light L). The inside of the cover 104 is filled with a transparent resin material 105 (see FIG. 4). Note that the cover 104 may be formed in a hollow shape. An opening window 108a of a reflecting surface 108, which will be described later, is formed at the tip (upper end in FIG. 4) of the outer peripheral surface of the cover 104, and the illumination light L is directed to the front side of the illumination light source 22 (the diaphragm 24 side). A pair of slit-shaped translucent portions 106 are provided so that the light can be emitted through them. Each translucent portion 106 is formed at the tip of the cover 104 at a position offset from the central axis CA with respect to the central axis CA. Specifically, each translucent portion 106 extends in a direction perpendicular to the central axis CA and is formed in a symmetrical slit shape with the central axis CA interposed therebetween.

A reflecting surface 108 capable of reflecting the illumination light L is formed on the outer surface of the cover 104 . In addition, when the cover 104 is formed in a hollow shape, the reflecting surface 108 may be formed on the inner surface of the cover 104 . In addition, in FIG. 4, the thickness of the layer having the reflective surface 108 is exaggerated to clarify the reflective surface 108. As shown in FIG. The reflecting surface 108 is, for example, a mirror surface, and is formed on substantially the entire surface of the outer surface of the cover 104 in a region different from the light transmitting portion 106, and totally reflects light in the wavelength range of the illumination light L. FIG. An opening window 108 a that exposes the translucent portion 106 is formed in the reflecting surface 108 . Therefore, of the illumination light L emitted from the light-emitting portion 100, the illumination light L that does not enter the light-transmitting portion 106 is reflected by the reflecting surface 108 and reflected/scattered by the surfaces of the light conversion material 100c and the excitation light source 100a. is repeated, the light is emitted from the area where the reflecting surface 108 is not formed, that is, the translucent portion 106 . Therefore, in the present embodiment, the illumination light L that does not directly enter the translucent portion 106 from the light emitting portion 100 can also be reused. As a result, the brightness of the illumination light source 22 is increased without increasing power consumption.

As described above, the illumination light source 22 of the present embodiment can collect the illumination light L emitted from the light emitting portion 100 to the light transmitting portion 106 by the reflecting surface 108 and emit the illumination light L only from the light transmitting portion 106. . As a result, it is possible to reduce the amount of the illumination light L blocked by the light blocking portion 24b of the diaphragm 24 positioned on the central axis CA (illumination optical axis OB). This makes it possible to increase the amount of the illumination light L that passes through the diaphragm 24 in the illumination light L emitted from the light emitting unit 100, that is, the amount of the illumination light L that is used to illuminate the fundus oculi Ef. lighting can be performed efficiently.

[others]
FIG. 6 is an explanatory diagram showing a modification of the shape of the translucent portion 106. As shown in FIG. In the above-described embodiment (see FIG. 3), when the illumination light source 22 is viewed from the diaphragm 24 side, a portion of the light transmitting portion 106 is curved. , and may also be changed to shapes other than those shown in FIGS. Also, the number of translucent portions 106 formed on the cover 104 may be changed to one or three or more.

FIG. 7 is an explanatory diagram showing a modification of the light emitting section 100. As shown in FIG. In the above embodiment, a white LED was used as an example of the light emitting unit 100, but any single color LED 100d may be used. In this case, instead of the excitation light source 100a and the light conversion material 100c, a monochromatic LED 100d is provided in the light emitting section 100, and the light emitted from this monochromatic LED 100d becomes the illumination light L.

FIG. 8 is a schematic diagram showing an example of a normal fundus camera 10A (including a multifunction device) that does not perform slit scan photography. Note that the configuration of the fundus camera 10A is not limited to the configuration shown in FIG.

The fundus camera 10A is provided with an illumination system 200 for illuminating the fundus oculi Ef and a light receiving system 220 for observing and photographing the fundus oculi Ef.

The illumination system 200 includes an illumination light source 201, a condenser lens 202, a xenon lamp 203, a condenser lens 204, exciter filters 205 and 206, an aperture 207, a mirror 208, a liquid crystal display 209, an aperture 210, It comprises a relay lens 211 , a perforated mirror 212 and an objective lens 213 .

The light receiving system 220 includes an objective lens 213, a perforated mirror 212 (a hole portion 212a), a diaphragm 221, barrier filters 222 and 223, a focusing lens 224, a fixed lens 225, a photographing lens 226, and a quick return. Mirror 227 (rotational axis 227a), field lens 228, switching mirror 229 (rotational axis 229a), eyepiece lens 230, relay lens 231, mirror 232, relay lens 233, and still image capturing of fundus oculi Ef and an imaging device 235 for capturing moving images of the fundus oculi Ef.

FIG. 9 is a front view of the diaphragm 207 of the fundus camera 10A shown in FIG. FIG. 10 is an explanatory diagram showing an example of the illumination light source 201 of the fundus camera 10A shown in FIG. As shown in FIG. 9, the diaphragm 207 has a ring-shaped opening 207a and a light blocking portion 207b surrounded by the opening 207a, and has the same function as the diaphragm 24 of the above embodiment. Although not shown in FIG. 9, a holding member may be provided inside the opening 207a to hold the light shielding portion 207b.

As shown in FIG. 10, the illumination light source 201 has basically the same configuration as the illumination light source 22 of the above embodiment, except that the translucent portion 106 is formed in a ring shape centering on the central axis CA. is. In the retinal camera 10A having such an illumination light source 201, the diaphragm 207 may be omitted (the diaphragm 24 of the retinal camera 10 of the above embodiment is also the same).

In the above embodiment, the translucent portion 106 is made of a transparent resin material, but the translucent portion 106 may be an opening (through hole). Moreover, although the cover 104 and the reflecting surface 108 are formed separately in the above embodiment, they may be integrated. Furthermore, in the above-described embodiment, the reflective surface 108 is formed on substantially the entire surface of the outer surface of the cover 104 (or the inner surface if the cover 104 is hollow), except for the translucent portion 106 . may be formed in at least part of this region. Furthermore, the reflecting surface 108 may be formed on the front surface of the light emitting section 100 at a position that does not interfere with the emission of the illumination light L from the excitation light source 100a.

In the above embodiment, an example of the arrangement of the illumination system 20, the optical scanner 30, and the light receiving system 40 of the fundus camera 10 is shown in FIG. 1, but the arrangement of these parts can be changed as appropriate.

In each of the above embodiments, the illumination light sources 22 and 201 of the retinal cameras 10 and 10A have been described as examples, but the ophthalmologic apparatus for observing other observed parts of the eye E to be examined (for example, the anterior segment Ea) The present invention may be applied to the illumination light source 22 used.

10 fundus camera 20, 200 illumination system 22, 201 illumination light source 24, 207 diaphragm 24a, 207a aperture 24b, 207b light shielding part 26 slit aperture diaphragm 28 illumination system lens 30 optical scanner 31 lens 34 optical path dividing member 36 focus optical system 38 objective lens 40, 220 light receiving system 42 light receiving system lens 44 image sensor 44a light receiving surface 100 light emitting unit 100a excitation light source 100b base 100c transparent resin 100d single color LED
102 Lead wire 104 Cover 106 Translucent portion 108 Reflective surface 108a Opening window BW Bond wire CA Central axis E Eye to be examined Ea Anterior segment Ef Fundus L Illumination light L0 Illumination light LB Return light LS Illumination light OB Illumination optical axis

Claims (6)

In an illumination light source of an ophthalmologic apparatus that irradiates an eye to be inspected with illumination light,
a light emitting unit that emits the illumination light;
a cover that covers the light emitting unit;
one or a plurality of translucent portions provided in the cover at a position eccentric from the central axis of the illumination light source;
with
The illumination light source in which the cover emits the illumination light only from the translucent portion. 2. The illumination light source according to claim 1, wherein at least part of the area different from the translucent portion in the outer surface or the inner surface of the cover is a reflective surface. 3. The illumination light source according to claim 1, wherein the translucent portion is formed in a pair of slit-like shapes perpendicular to and symmetrical with respect to the central axis. 3. The illumination light source according to claim 1, wherein the translucent portion is formed in a ring shape around the central axis. An ophthalmic apparatus comprising the illumination light source according to any one of claims 1 to 4. 6. The ophthalmologic apparatus according to claim 5, further comprising a diaphragm having a ring-shaped aperture and through which the illumination light emitted from the illumination light source passes.

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