Ophthalmic apparatus, method of controlling same, and recording medium
An ophthalmic apparatus includes an illumination optical system that generates slit-shaped illumination light using a first light source; an optical scanner that deflects the illumination light to a fundus of a subject's eye; an imaging optical system that captures light from the fundus using a rolling shutter method; an acquisition unit that acquires a fundus image of the subject's eye using light from a second light source; a flare determination unit that determines whether or not flare occurs by analyzing the fundus image; a controller that performs flare optimization control by controlling at least one of the first light source, the illumination optical system, the optical scanner, the imaging optical system, and the image sensor based on a first determination result obtained by the flare determination unit; and an image forming unit that forms an image of the fundus when the flare does not occur.
1 . An ophthalmic apparatus, comprising:
a first light source;
an illumination optical system configured to generate slit-shaped illumination light using light from the first light source;
an optical scanner configured to deflect the illumination light to guide the illumination light to a fundus of a subject's eye;
an imaging optical system configured to guide returning light of the illumination light from the fundus to an image sensor, the image sensor being configured to capture light receiving result of the returning light using a rolling shutter method, the light receiving result corresponding to an irradiated position of the illumination on the fundus; and
processing circuitry configured
to acquire a fundus image of the subject's eye using light from a second light source, as an acquisition unit;
to determine whether or not flare occurs, by analyzing the fundus image of the subject's eye, as a flare determination unit;
to perform flare optimization control in which an imaging condition is changed so as to eliminate an occurrence of the flare, by controlling at least one of the first light source, the illumination optical system, the optical scanner, the imaging optical system, and the image sensor based on a first determination result obtained by the flare determination unit, as a controller; and
to form an image of the fundus based on the light receiving result captured by the image sensor, when it is determined that the flare does not occur, based on a second determination result obtained by the flare determination unit using the fundus image acquired by the acquisition unit under the imaging condition changed by performing the flare optimization control, as an image forming unit, wherein
the imaging optical system includes an imaging aperture in which a third aperture whose opening shape can be changed is formed, and capable of being arranged at the iris conjugate position substantially conjugate optically to the iris of the subject's eye, and
the controller is configured to control the imaging optical system so as to reduce a size of the opening shape of the third aperture, when it is determined, based on the first determination result, that the flare occurs.
2 . The ophthalmic apparatus of claim 1 , wherein
the illumination optical system includes:
a slit in which a slit-shaped first aperture whose opening shape can be changed is formed, and capable of being arranged at a fundus conjugate position substantially conjugate optically to the fundus; and
an iris aperture in which a second aperture whose opening shape can be changed is formed, and capable of being arranged at an iris conjugate position substantially conjugate optically to an iris of the subject's eye between the first light source and the slit, and
the controller is configured to control the illumination optical system so as to reduce a size of the opening shape of at least one of the first aperture and the second aperture, when it is determined, based on the first determination result, that the flare occurs.
3 . The ophthalmic apparatus of claim 1 , wherein
the imaging aperture includes a perforated mirror configured to couple an optical path of the illumination optical system with an optical path of the imaging optical system, the imaging optical system being arranged in an optical axis direction passing through the third aperture, and to guide the illumination light reflected on a peripheral region of the third aperture to the fundus.
4 . The ophthalmic apparatus of claim 1 , wherein
the controller is configured to repeatedly perform the flare optimization control until it is determined, based on the second determination result, that the flare does not occur.
5 . The ophthalmic apparatus of claim 1 , wherein:
the processing circuitry is further configured as an involuntary eye movement determination unit configured to determine a state of an involuntary eye movement of the subject's eye; and
the processing circuitry is further configured as a light amount determination unit configured to determine whether or not a light amount of light output from the first light source can be increased, wherein
the controller is configured to change the imaging condition based on a determination result obtained by the involuntary eye movement determination unit or a determination result obtained by the light amount determination unit.
6 . The ophthalmic apparatus of claim 5 , wherein
the controller is configured to control at least one of the illumination optical system, the optical scanner, and the image sensor so as to lengthen an imaging time for the fundus, when it is determined by the involuntary eye movement determination unit that the involuntary eye movement is small, or when it is determined by the light amount determination unit that the light amount cannot be increased.
7 . The ophthalmic apparatus of claim 5 , wherein
the controller is configured to control the first light source so as to increase the light amount, when it is determined by the involuntary eye movement determination unit that the involuntary eye movement is large and it is determined by the light amount determination unit that the light amount can be increased.
8 . The ophthalmic apparatus of claim 1 , wherein
the acquisition unit is configured to acquire the fundus image based on a light receiving result of returning light of light from the second light source captured by the image sensor.
9 . The ophthalmic apparatus of claim 1 , wherein
the controller is configured to perform the flare optimization control when it is determined, based on the first determination result, that the flare occurs, and to perform imaging time optimization control in which an imaging condition is changed so as to shorten an imaging time for the fundus, by controlling at least one of the illumination optical system, the optical scanner, the imaging optical system, and the image sensor when it is determined, based on the first determination result, that the flare does not occur.
10 . The ophthalmic apparatus of claim 1 , wherein
the image sensor includes a CMOS image sensor.
11 . An method of controlling an ophthalmic apparatus comprising:
a first light source; and
an illumination optical system configured to generate slit-shaped illumination light using light from the first light source;
an optical scanner configured to deflect the illumination light to guide the illumination light to a fundus of a subject's eye;
an imaging optical system configured to guide returning light of the illumination light from the fundus to an image sensor, the image sensor being configured to capture light receiving result of the returning light, the light receiving result corresponding to an irradiated position of the illumination on the fundus; and
processing circuitry configured as an acquisition unit configured to acquire a fundus image of the subject's eye using light from a second light source,
the method comprising:
a first flare determination step of determining whether or not flare occurs, by analyzing the fundus image of the subject's eye;
a control step of performing flare optimization control in which an imaging condition is changed so as to eliminate an occurrence of the flare, by controlling at least one of the first light source, the illumination optical system, the optical scanner, the imaging optical system, and the image sensor based on a first determination result obtained in the first flare determination step;
a second flare determination step of determining whether or not flare occurs, by analyzing the fundus image acquired by the acquisition unit under the imaging condition changed by performing the flare optimization control; and
an image forming step of forming an image of the fundus based on the light receiving result captured by the image sensor, when it is determined, based on a second determination result obtained in the second flare determination step, that the flare does not occur, wherein
the imaging optical system includes an imaging aperture in which a third aperture whose opening shape can be changed is formed, and capable of being arranged at the iris conjugate position substantially conjugate optically to the iris of the subject's eye, and
the control step is performed to control the imaging optical system so as to reduce a size of the opening shape of the third aperture, when it is determined, based on the first determination result, that the flare occurs.
12 . The method of controlling the ophthalmic apparatus of claim 11 , wherein
the illumination optical system includes:
a slit in which a slit-shaped first aperture whose opening shape can be changed is formed, and capable of being arranged at a fundus conjugate position substantially conjugate optically to the fundus; and
an iris aperture in which a second aperture whose opening shape can be changed is formed, and capable of being arranged at an iris conjugate position substantially conjugate optically to an iris of the subject's eye between the first light source and the slit, and
the control step is performed to control the illumination optical system so as to reduce a size of the opening shape of at least one of the first aperture and the second aperture, when it is determined, based on the first determination result, that the flare occurs.
13 . The method of controlling the ophthalmic apparatus of claim 11 , wherein
the control step is performed to repeatedly perform the flare optimization control until it is determined, based on the second determination result, that the flare does not occur.
14 . The method of controlling the ophthalmic apparatus of claim 11 , further comprising:
an involuntary eye movement determination step of determining a state of an involuntary eye movement of the subject's eye; and
a light amount determination step of determining whether or not light output from the first light source can be increased, wherein
the control step is performed to change the imaging condition based on a determination result obtained in the involuntary eye movement determination step or a determination result obtained in the light amount determination step.
15 . The method of controlling the ophthalmic apparatus of claim 14 , wherein
the control step is performed to control at least one of the illumination optical system, the optical scanner, and the image sensor so as to lengthen an imaging time for the fundus, when it is determined in the involuntary eye movement determination step that the involuntary eye movement is small, or when it is determined in the light amount determination step that the light amount cannot be increased.
16 . The method of controlling the ophthalmic apparatus of claim 14 , wherein
the control step is performed to control the first light source so as to increase the light amount, when it is determined in the involuntary eye movement determination step that the involuntary eye movement is large and it is determined in the light amount determination step that the light amount can be increased.
17 . The method of controlling the ophthalmic apparatus of claim 11 , wherein
the control step is performed to perform the flare optimization control when it is determined, based on the first determination result, that the flare occurs, and to perform imaging time optimization control in which an imaging condition is changed so as to shorten an imaging time for the fundus, by controlling at least one of the illumination optical system, the optical scanner, the imaging optical system, and the image sensor when it is determined, based on the first determination result, that the flare does not occur.
18 . The method of controlling the ophthalmic apparatus of claim 11 , wherein
the image sensor includes a CMOS image sensor.
19 . A non-transitory computer readable recording medium storing a program of causing a computer to execute each step of the method of controlling the ophthalmic apparatus of claim 11 .