OPHTHALMOLOGIC APPARATUS, CONTROL METHOD

• US 20140132930A1
• Filed: 11/08/2013
• Published: 05/15/2014
• Est. Priority Date: 11/09/2012
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ogura, Hiraku
• Granted Patent: US 9,314,158 B2
• Time in Patent Office: Days
• US Class Current: 351/211
• CPC Class Codes: A61B 3/102 for optical coherence tomography [OCT]
• CPC Class Codes: A61B 3/12 for looking at the eye fundus, e.g. ophthalmoscopes A61B3/13 takes precedence
• CPC Class Codes: A61B 3/14 Arrangements specially adapted for eye photography apparatus or arrangements for taking photographs per se G03B

Abstract

An ophthalmologic apparatus includes a focusing lens provided in an optical path connecting a subject'"'"'s eye and an imaging unit, a diopter correction lens provided in the optical path to be insertable and removable, and a position determination unit configured to determine a position of the focusing lens on the optical path in a state where the diopter correction lens is inserted, based on an in-focus state where the diopter correction lens is not inserted.

Claims

1. An ophthalmologic apparatus comprising:

a focusing lens provided in an optical path connecting a subject'"'"'s eye and an imaging unit;

a diopter correction lens provided in the optical path to be insertable and removable; and

a position determination unit configured to determine a position of the focusing lens on the optical path in a state where the diopter correction lens is inserted, based on an in-focus state where the diopter correction lens is not inserted.

2. The ophthalmologic apparatus according to claim 1, further comprising:

a control unit configured to control insertion and removal of the diopter correction lens into and from the optical path, and

a driving unit configured to drive the focusing lens,

wherein the control unit inserts the diopter correction lens into the optical path after the driving unit drives the focusing lens to the position determined by the position determination unit.

3. The ophthalmologic apparatus according to claim 2, further comprising a determination unit configured to determine whether the diopter correction lens is to be inserted into the optical path based on the in-focus state where the diopter correction lens is not inserted,

wherein the position determination unit determines the position of the focusing lens on the optical path when the determination unit determines that the diopter correction lens is to be inserted.

4. The ophthalmologic apparatus according to claim 3, wherein

the driving unit drives the focusing lens to a predetermined position on the optical path when the determination unit determines that the diopter correction lens is to be inserted, and

the position determination unit determines the position of the focusing lens on the optical path in a state where the diopter correction lens is inserted, based on an in-focus state where the focusing lens is arranged in the predetermined position.

5. The ophthalmologic apparatus according to claim 3, wherein the determination unit determines whether the diopter correction lens is to be inserted into the optical path in response to the driving of the focusing lens to a predetermined position by the driving unit.

6. The ophthalmologic apparatus according to claim 4, wherein the predetermined position is a limit position in a range in which the driving unit can drive the focusing lens.

7. The ophthalmologic apparatus according to claim 1, further comprising:

a projection unit configured to project divided indexes onto the subject'"'"'s eye, and

an acquisition unit configured to acquire a plurality of index images based on return light of the divided indexes obtained via the focusing lens from the subject'"'"'s eye,

wherein the position determination unit determines a position of the focusing lens on the optical path in a state where the diopter correction lens is inserted, based on the in-focus state where the diopter correction lens is not inserted, which is obtained from the plurality of index images.

8. The ophthalmologic apparatus according to claim 7, wherein the position determination unit determines the position of the focusing lens on the optical path in a state where the diopter correction lens is inserted, based on the in-focus state where the diopter correction lens is not inserted, which is obtained from an amount of shift between the plurality of target images.

9. The ophthalmologic apparatus according to claim 1, wherein the position determination unit determines the position of the focusing lens on the optical path in a state where the diopter correction lens is inserted, based on the in-focus state where the diopter correction lens is not inserted and the position of the focusing lens in the optical path.

10. The ophthalmologic apparatus according to claim 3, wherein the determination unit acquires an amount of driving of the focusing lens required for focusing based on the in-focus state where the diopter correction lens is not inserted, and determines that the diopter correction lens is to be inserted into the optical path if the focusing lens is beyond a drivable range when driven by the amount of driving.

11. The ophthalmologic apparatus according to claim 3, wherein the determination unit acquires the diopter of the subject'"'"'s eye based on the in-focus state where the diopter correction lens is not inserted, and determines whether the diopter correction lens is to be inserted into the optical path based on the diopter.

12. The ophthalmologic apparatus according to claim 11, wherein

the diopter correction lens includes a diopter correction lens for hyperopia and a diopter correction lens for miopia, and

the determination unit determines which of the diopter correction lens for hyperopia and the diopter correction lens for miopia is to be inserted, based on the in-focus state where the diopter correction lens is not inserted.

13. The ophthalmologic apparatus according to claim 1, wherein the position determination unit determines the position of the focusing lens on the optical path in a state where the diopter correction lens is inserted based on the diopter of the subject'"'"'s eye obtained based on the in-focus state where the diopter correction lens is not inserted and refractive power of the diopter correction lens.

14. The ophthalmologic apparatus according to claim 13, wherein the position determination unit determines the position of the focusing lens on the optical path in a state where the diopter correction lens is inserted, based on a difference between the diopter of the subject'"'"'s eye and the refractive power of the diopter correction lens.

15. The ophthalmologic apparatus according to claim 1, wherein the position of the focusing lens on the optical path in a state where the diopter correction lens is inserted is an in-focus position in a state where the diopter correction lens is inserted.

16. A control method comprising:

detecting an in-focus state where a diopter correction lens is not inserted into an optical path connecting a subject'"'"'s eye and an imaging unit; and

determining a position of a focusing lens on the optical path provided in the optical path in a state where the diopter correction lens is inserted into the optical path, based on the detected in-focus state.