JP5787954B2 - Ophthalmic apparatus and control method thereof - Google Patents

Description

  The present invention relates to an ophthalmologic apparatus for photographing an eye to be examined using a plurality of white LED elements as a photographing light source and a control method thereof.

  Conventionally, in a non-mydriatic retinal camera used for group examinations or the like, the observation light is inserted into the halogen light source by inserting a visible light cut filter in front of the halogen light source in order to prevent the subject's miosis. The subject is irradiated with only the infrared component. At the time of shooting, the xenon light source is caused to emit light and shooting is performed with visible light.

  In addition, the illumination light for illuminating the fundus needs to separate the fundus illumination light and the imaging light from the fundus so that the reflected light generated by the cornea and the crystalline lens of the eye to be examined does not enter the imaging aperture. For this purpose, a stop having a ring-shaped opening is disposed in the illumination optical system at a position optically conjugate with the cornea and the crystalline lens. Similarly, a stop having a circular opening is disposed in the photographing optical system and a pupil stop having a ring-shaped opening is disposed in the illumination optical system at a position optically conjugate with the pupil.

  Conventionally, when photographing, the xenon tube is used to emit light. At this time, since it is a xenon tube, it is difficult to control the ring-shaped light amount distribution. In recent years, light sources other than halogen light sources have been studied from the viewpoints of downsizing of electrical parts, energy saving, cost reduction, and prevention of heat generation of the light source part. As a promising candidate, an LED (light-emitting diode) element that emits white light has high luminance, and it has been studied to use it as a photographing light source of a fundus camera.

  As a technique related to fundus illumination using this LED element, a fundus oculi which can change the diameter of the ring light when forming a ring light source in which a plurality of white LED elements are discretely arranged in a ring shape and illuminates the fundus A camera is disclosed in Patent Document 1. Thereby, it is possible to avoid the illumination scattered light from the anterior segment of the eye to be examined from being mixed into the photographed image, and to optimize the brightness and contrast of the photographed image.

  Further, Patent Document 2 discloses an ophthalmologic photographing apparatus that diffuses and reflects light emitted from a plurality of LED elements including white LED elements in order to uniformly illuminate the fundus.

JP 2007-29726 A JP 2006-174984 A

  Here, in the conventional ophthalmologic photographing apparatus having a visible light source including a plurality of white LED elements, the light emission amount of each of the white LED elements of the plurality of white LED elements is not independently changed.

In order to achieve the above object, an ophthalmic apparatus according to the present invention provides:
Illumination means for illuminating the fundus of the subject 's eye with visible light from a visible light source including a plurality of white LED elements arranged in a substantially ring shape along the opening through a diaphragm means having a substantially ring-shaped opening. When,
Changing means for independently changing the light emission amounts of the plurality of white LED elements.

  According to the present invention, it is possible to independently change the light emission amount of each white LED element of the plurality of white LED elements.

It is a block diagram of an Example. It is a front view of a black spot plate. It is an arrangement plan of a visible light LED element. It is explanatory drawing of the fundus part illuminated by the visible light LED element. It is explanatory drawing of the shadow part of a fundus image. It is explanatory drawing of the fundus image in which the shadow part was formed. It is a front view of a photography mode selection means.

  The present invention will be described in detail based on the embodiments shown in the drawings.

  FIG. 1 is a configuration diagram of a non-mydriatic fundus camera that is an example of an ophthalmologic apparatus according to the present embodiment. In the emission direction of the observation illumination light source 1, a pupil stop 2 having a substantially ring-shaped opening, a crystalline lens stop 3 having a substantially ring-shaped opening, a mirror 4, a relay lens 5, a black dot plate 6, and a relay lens. 7. A corneal diaphragm 8 having a substantially ring-shaped opening and a perforated mirror 9 are arranged.

  The observation illumination light source 1 has a plurality of LED elements arranged in a substantially ring shape and discretely. The black spot plate 6 is formed of a glass plate having a small shield 6a called a black spot at the center as shown in FIG.

  The mirror 4 reflects visible light and transmits near-infrared light, and is fixed in the optical path or has general total reflection characteristics, and is retracted from the optical path during observation. It may be a flip-up mirror that is sometimes inserted into the optical path. That is, the mirror 4 is an example of a wavelength separation unit having a characteristic of transmitting one of visible light from the photographing illumination light source 12 and infrared light from the observation illumination light source 1 and reflecting the other. .

  In the incident direction of the mirror 4, a lens diaphragm 10 having a substantially ring-shaped opening, a pupil diaphragm 11, and a photographing illumination light source 12 that is a visible light source are arranged. As shown in FIG. 3, the photographing illumination light source 12 includes a plurality of LED elements 12 a,... (A plurality of white LED elements) arranged in a substantially ring shape and discretely along the opening of the pupil stop 11. Yes.

  An objective lens 13 is disposed between the perforated mirror 9 and the eye E to be examined. An illumination optical system is configured by such an optical system from the observation illumination light source 1 and the imaging illumination light source 12 to the perforated mirror 9 and the objective lens 13.

  Arranged behind the perforated mirror 9 are an imaging aperture 14, a focus lens 15, an imaging lens 16, a flip-up mirror 17 that can be retracted from the optical path, and an imaging means 18. The imaging means 18 has sensitivity in the visible wavelength region, and receives a reflected light from the fundus of the eye E during imaging to capture a fundus image. The optical system from the objective lens 13 to the imaging means 18 constitutes a photographing optical system.

  In the reflection direction of the flip-up mirror 17, a reflection mirror 19, a field lens 20, a relay lens 21, and an image sensor 22 sensitive to near-infrared light are arranged to constitute an observation optical system.

  The photographing illumination light source 12 is connected to the output of the light quantity balance changing means 23. The light quantity balance changing means 23 is supplied with the output of the photographing mode selecting means 24 and the output of the left and right eye detecting means 25 for detecting the left and right eyes of the eye E. It is connected.

  By driving the light quantity balance changing means 23, it is possible to independently change the light quantity of each LED element 12a,... Of the photographing illumination light source 12 (selectively change the light emission quantity). For example, when the LED element 12a shown in FIG. 3 is caused to emit light, it becomes an eccentric position 12a ′ outside the optical axis on the pupil as shown in FIG. 4, and the luminous flux is substantially slit-like in the vertical direction as shown by the solid line. The luminous flux is illuminated. In addition, the light beam emitted from the LED element 12b on the opposite side of the LED element 12a is positioned at the position 12b 'on the pupil, and becomes a light beam that illuminates in a substantially slit shape indicated by a dotted line. The other LED elements 12x also have illumination light according to their respective angles, and irradiate the entire shooting angle of view.

  FIG. 5 is a sectional view formed by a line connecting the position 12a 'in FIG. 4 and the fundus R1-R2 shown in FIG. 4, and shows the nipple O having the most unevenness in the fundus. Since the illumination light emitted from the position 12a 'has an angle with respect to the nipple O, the two portions where the illumination light is shielded corresponding to the unevenness of the fundus occupy are shaded portions S indicated by dots.

  FIG. 6 shows a three-dimensional image having a shaded portion S of a fundus image taken on the basis of light reflected from the fundus. In FIG. 6, the blood vessel V on the retina is not as large as the papilla O but is a convex portion with respect to the retinal surface, so that a shadow portion S is similarly generated.

  When the examiner performs normal color photographing of the fundus of the eye E, the photographing mode selection unit 24 shown in FIG. 7 clicks a “color photographing” (color photographing mode) button. When “color photographing” is selected, the light quantity balance changing means 23 is driven so that all the LED elements 12a of the photographing illumination light source 12 have the same light quantity regardless of the result of the left and right eye detecting means 25. And control so that the fundus is irradiated almost uniformly. When the examiner presses a photographing switch (not shown), the light quantity balance changing unit 23 is driven in synchronization with the flip-up of the flip-up mirror 17 to emit all the LED elements 12a,. To do.

  When the examiner clicks the “color stereoscopic shooting” (stereoscopic shooting mode) button on the shooting mode selection unit 24, the light quantity balance changing unit 23 receives, for example, the left eye as a result of the left and right eye detection unit 25, and the shooting switch is pressed. Then, the LED element 12a is driven to form the shadow portion S on the opposite side of the macular portion m. That is, the LED element 12a of the photographing illumination light source 12 emits light more strongly than the other LED elements 12x, and thereby light is emitted from the position 12a ′ shown in FIG. 4, and a fundus image as shown in FIG. 6 can be obtained. .

  Next, the examiner moves the fundus camera to the right eye side to photograph the opposite eye, switches the left and right eyes, and clicks the “color stereoscopic photographing” button in the photographing mode selection means 24. Thereby, the light quantity balance changing means 23 receives the result (right eye) of the left and right eye detecting means 25, and when the photographing switch is pressed, the shadow portion S is formed on the macular portion m side. That is, when only the LED element 12b of the photographing illumination light source 12 emits light more strongly than the other LED elements 12x, the photographed image has a shadow portion formed on the macular portion m side in the same manner as the left eye, and the fundus An image can be taken. For this reason, a fundus image having a shadow portion on the macular portion m side can be obtained.

  In addition to these embodiments, only a part of the illuminating light source 12 for photographing, for example, only the LED element 12a, emits light, and the other LED elements 12x are extinguished and photographed with a slit-like light beam at the time of “color stereoscopic photographing”. Is also possible.

  As described above, according to the fundus camera according to the present embodiment, directional fundus illumination can be performed by the plurality of LED elements. Thereby, for example, the fundus can be shaded. In addition, for example, a fundus image with a more stereoscopic effect can be obtained. Further, if left and right eye detection means for detecting the left and right eye switching of the eye to be examined is further provided, for example, the same effect can be obtained in conjunction with the left and right eye switching by changing the light quantity balance.

DESCRIPTION OF SYMBOLS 1 Observation illumination light source 9 Perforated mirror 12 Imaging illumination light source 12a LED element 13 Objective lens 18 Imaging means 22 Imaging element 23 Light quantity balance changing means 24 Shooting mode selection means 25 Left-right eye detection means

Claims (17)

Illumination means for illuminating the fundus of the subject's eye with visible light from a visible light source including a plurality of white LED elements arranged in a substantially ring shape along the opening through a diaphragm means having a substantially ring-shaped opening. When,
Changing means for independently changing the light emission amount of the plurality of white LED elements;
An ophthalmologic apparatus comprising:   The changing means may independently change the light emission amounts of the plurality of white LED elements so that some of the plurality of white LED elements emit light more strongly than other white LED elements. The ophthalmic apparatus according to claim 1.   The ophthalmic apparatus according to claim 2, wherein the changing unit changes the white LED elements that emit light strongly in the plurality of white LED elements according to the left and right eyes of the eye to be examined. Further comprising left and right eye detection means for detecting the left and right eye switching of the eye to be examined,
4. The ophthalmic apparatus according to claim 2, wherein the changing unit changes the strongly emitting white LED element in the plurality of white LED elements based on an output of the left and right eye detecting unit. It further has imaging means that has sensitivity in the visible wavelength region, receives reflected light from the fundus and images the fundus,
The illumination means illuminates the fundus from the optical axis by emitting some white LED elements of the plurality of white LED elements more strongly than other white LED elements,
The imaging unit emits the white LED elements more strongly than the other white LED elements to illuminate the fundus from the optical axis, so that a shadow portion corresponding to the unevenness of the fundus is formed on the fundus. The ophthalmologic apparatus according to any one of claims 2 to 4, wherein the fundus is imaged in a state of being in contact.   A perforated mirror for reflecting the visible light from the visible light source and transmitting the reflected light from the fundus illuminating the reflected visible light through an objective lens and guiding the reflected light to the imaging means; The ophthalmologic apparatus according to claim 5. A shooting mode selection means for selecting one of a plurality of shooting modes including a stereoscopic shooting mode and a color shooting mode;
The changing means is
When the stereoscopic mode is selected, light is emitted from some of the plurality of white LED elements so that some of the white LED elements emit light more strongly than other white LED elements. Selectively change the amount,
When the color photographing mode is selected, the amount of light emitted from a part of the plurality of white LED elements is selectively changed so that the amount of light emitted by the plurality of white LED elements is substantially uniform. The ophthalmologic apparatus according to any one of claims 1 to 6. The diaphragm means includes a pupil diaphragm, a lens diaphragm, and a corneal diaphragm,
The illumination means illuminates the fundus with the visible light through the pupil diaphragm, the lens diaphragm, and the corneal diaphragm. An ophthalmic device according to claim 1.   The ophthalmologic apparatus according to any one of claims 1 to 8, wherein the plurality of white LED elements are discretely arranged along the opening.   The ophthalmologic apparatus according to claim 1, wherein the illumination unit includes an observation illumination light source that is different from the visible light source and includes a plurality of LED elements.   The illumination means includes wavelength separation means having a characteristic of transmitting one of visible light from the visible light source and infrared light from the observation illumination light source and reflecting the other. The ophthalmic apparatus according to claim 10.   The illumination means includes optical means that reflects visible light from the visible light source and is retracted from the optical path when observing the fundus and inserted into the optical path when photographing the fundus. The ophthalmic apparatus according to claim 10. A step of independently changing the light emission amount of the plurality of white LED elements;
Illuminating the fundus of the subject's eye with visible light from a visible light source including the plurality of white LED elements arranged in a substantially ring shape along the opening through a diaphragm unit having a substantially ring-shaped opening. When,
A method for controlling an ophthalmic apparatus, comprising: In the step of changing, the light emission amounts of the plurality of white LED elements are independently changed so that some of the plurality of white LED elements emit light more strongly than other white LED elements. control method for an ophthalmologic apparatus according to claim 1, wherein the.   15. The method of controlling an ophthalmologic apparatus according to claim 14, wherein in the changing step, the white LED elements that emit light strongly in the plurality of white LED elements are changed according to the left and right eyes of the eye to be examined.   A state in which some white LED elements among the plurality of white LED elements emit light more strongly than other white LED elements to illuminate the fundus from the optical axis, and a shadow portion corresponding to the unevenness of the fundus is formed. The method for controlling an ophthalmologic apparatus according to claim 14, further comprising: imaging the fundus. Further comprising selecting one of a plurality of shooting modes including a stereoscopic shooting mode and a color shooting mode;
In the changing step,
When the stereoscopic mode is selected, light is emitted from some of the plurality of white LED elements so that some of the white LED elements emit light more strongly than other white LED elements. Selectively change the amount,
When the color photographing mode is selected, the amount of light emitted from a part of the plurality of white LED elements is selectively changed so that the amount of light emitted by the plurality of white LED elements is substantially uniform. The method for controlling an ophthalmologic apparatus according to any one of claims 13 to 16.

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