Ophthalmic apparatus, method of controlling same, and recording medium

Patent metadata

Field	Value
Publication number	US-12303196-B2
Application number	US-202217692231-A
Country	US
Kind code	B2
Filing date	Mar 11, 2022
Priority date	Sep 11, 2019
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

An ophthalmic apparatus includes an illumination optical system, an imaging optical system, and a controller. The illumination optical system is configured to generate illumination light using light from a light source, and to illuminate a changeable illumination region on a predetermined site of a subject's eye with the illumination light having a light intensity corresponding to a size of the illumination region. The imaging optical system is configured to guide returning light of the illumination light from the subject's eye to a light receiving surface of an image sensor. The controller is configured to control the image sensor to set an opening range so as to overlap an illumination range of the returning light on the light receiving surface corresponding to the illumination region and to capture a light receiving result obtained by a light receiving element in the set opening range.

First claim

The invention claimed is:

1. An ophthalmic apparatus, comprising:
an illumination optical system configured to generate illumination light using light from a light source, and to illuminate a changeable illumination region on a predetermined site of a subject's eye with the illumination light having a light intensity corresponding to a size of the illumination region;
an imaging optical system configured to guide returning light of the illumination light from the subject's eye to a light receiving surface of an image sensor;
a controller configured to control the image sensor to set a readout range that is a range of light receiving elements to be read out so as to overlap an illumination range of the returning light on the light receiving surface corresponding to the illumination region and to capture a light receiving result obtained by a light receiving element in the set readout range; and
a perforated mirror arranged at a position substantially conjugate optically to an iris of the subject's eye and having a hole that an optical axis of one of the illumination optical system and the imaging optical system passes through, wherein
the other of the illumination optical system and the imaging optical system is placed in a reflection direction of the perforated mirror, and
the illumination optical system includes:
a light modulator capable of being placed at a position substantially conjugate optically to the predetermined site, and configured to modulate the illumination light and to guide the modulated illumination light to the subject's eye; and
an iris aperture placed between the light source and the light modulator, and capable of being placed at a position substantially conjugate optically to the iris of the subject's eye, wherein

the illumination optical system includes a first lens capable of being moved along an optical path of the illumination light modulated by the light modulator,
the controller is configured to control a movement of the first lens along the optical path in accordance with a dioptric power of the subject's eye,
the illumination optical system includes a second lens placed between the light modulator and the iris aperture, and capable of being moved along an optical path of the illumination light, and
the controller is configured to control a movement of the iris aperture along the optical path of the illumination light.

2. The ophthalmic apparatus of claim 1 , wherein
the illumination optical system is configured to generate the illumination light so that the light intensity increases when the size of the illumination region is switched to a smaller size and that the light intensity decreases when the size of the illumination area is switched to a larger size.

3. The ophthalmic apparatus of claim 1 , wherein
the illumination optical system is configured to change the light intensity of the illumination light so that an irradiance on an anterior segment of the subject's eye remains constant.

4. The ophthalmic apparatus of claim 1 , wherein
the controller is configured to control the light source to change the light intensity.

5. The ophthalmic apparatus of claim 1 , wherein
the illumination optical system includes a neutral density filter whose amount of light reduction is variable, the neutral density filter being placed in an optical path of the light from the light source, and the light intensity is changed by changing the amount of light reduction.

6. The ophthalmic apparatus of claim 1 , wherein
the controller is configured to control the illumination optical system so as to illuminate an illumination region with the illumination light, the illumination region corresponding to a designated imaging mode among two or more imaging modes that differ in the size of the illumination region at the predetermined site.

7. The ophthalmic apparatus of claim 6 , further comprising
an image forming unit configured to form an image of the predetermined site based on a light receiving result obtained by the image sensor, wherein
in a first imaging mode, the controller is configured to control the image forming unit to form a first image based on a light receiving result obtained by illuminating a first illumination region corresponding to the first imaging mode with the illumination light, and to perform tracking control that moves the illumination optical system and the imaging optical system so as to follow the subject's eye by controlling a relative distance between the subject's eye and the imaging optical system, and
in a second imaging mode, the controller is configured to control the image forming unit to form a second image based on a light receiving result obtained by illuminating a second illumination region wider than the first illumination region with the illumination light, the second illumination region corresponding to the second imaging mode.

8. The ophthalmic apparatus of claim 1 , wherein
the controller is configured to capture the light receiving result using a rolling shutter method.

9. The ophthalmic apparatus of claim 1 , further comprising
an optical path coupling member configured to couple an optical path of the illumination optical system with an optical path of the imaging optical systems, wherein
the illumination optical system includes a light modulator capable of being placed at a position substantially conjugate optically to the predetermined site, and configured to modulate the illumination light and to guide the modulated illumination light to the subject's eye.

10. The ophthalmic apparatus of claim 9 , wherein
the illumination optical system includes a first lens capable of being moved along an optical path of the illumination light modulated by the light modulator, and
the controller is configured to control a movement of the first lens along the optical path in accordance with a dioptric power of the subject's eye.

11. The ophthalmic apparatus of claim 1 , further comprising
a perforated mirror arranged at a position substantially conjugate optically to an iris of the subject's eye and having a hole that an optical axis of one of the illumination optical system and the imaging optical system passes through, wherein
the other of the illumination optical system and the imaging optical system is placed in a reflection direction of the perforated mirror, and
the illumination optical system includes:
an optical scanner capable of being placed at a position substantially conjugate optically to the iris of the subject's eye, and configured to deflect the illumination light and to guide the deflected illumination light to the subject's eye;
an iris aperture placed between the light source and the optical scanner and capable of being placed at a position substantially conjugate optically to the iris of the subject's eye; and
a slit placed between the optical scanner and the iris aperture, having an aperture, and capable of being placed at a position substantially conjugate optically to the predetermined site.

12. The ophthalmic apparatus of claim 11 , further comprising
the controller is configured to control a movement of the slit along an optical path of the illumination light in accordance with a dioptric power of the subject's eye.

13. A method of controlling an ophthalmic apparatus comprising:
an illumination optical system configured to generate illumination light using light from a light source, and to illuminate a subject's eye with the illumination light; and
an imaging optical system configured to guide returning light of the illumination light from the subject's eye to a light receiving surface of an image sensor,
the method comprising:
an illuminatio

Assignees

• Topcon Corp

Inventors

• Mino Toshihiro
• Kim Jongsik
• Li Dawei
• Wang Zhenguo
• Chan Kinpui

Classifications

• A61B3/12 Primary

  for looking at the eye fundus, e.g. ophthalmoscopes (A61B3/13 takes precedence) · CPC title

• H04N23/72

  Combination of two or more compensation controls · CPC title

• G03B9/28

  Roller blind or flexible plate · CPC title

• A61B3/14

  Arrangements specially adapted for eye photography · CPC title

• A61B3/1025

  for confocal scanning · CPC title