Optical tomographic imaging apparatus, control method therefor, and program therefor

Patent metadata

Field	Value
Publication number	US-10165942-B2
Application number	US-201615534559-A
Country	US
Kind code	B2
Filing date	Jan 7, 2016
Priority date	Jan 9, 2015
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

Focus adjustment is enabled with respect to an object to be inspected even when an optical member for changing a field angle is inserted in order to change the field angle of an acquiring area of a tomographic image, and a clear tomographic image with a focus on the object to be inspected is acquired. In an optical tomographic imaging apparatus, an optical system includes a focus lens configured to focus a measuring light on the object to be inspected. The optical tomographic imaging apparatus includes a unit configured to compensate, when an optical member for changing a field angle is inserted between a scanning unit and the object to be inspected in order to change the field angle of an acquiring area of a tomographic image, a change in a focus position of the focus lens in association with the inserting.

First claim

The invention claimed is:

1. An optical tomographic imaging apparatus, comprising:
a light source;
an optical splitter configured to split a light emitted from the light source into a measuring light and a reference light;
a scanning unit configured to scan a fundus of an eye to be inspected with the measuring light;
an optical system configured to irradiate the fundus with the measuring light through the scanning unit;
a detector configured to receive an interference light between (1) a return light of the measuring light from the fundus and (2) the reference light; and
a calculation processing portion configured to process an output signal from the detector, to thereby acquire a tomographic image of the fundus,
wherein the optical system comprises a focus lens configured to focus the measuring light on the fundus, and
wherein the optical tomographic imaging apparatus further comprises a unit configured to compensate, when an optical member for changing a field angle is inserted between the scanning unit and the fundus in order to change the field angle of an acquiring area of the tomographic image of the fundus, a change in a focus position of the focus lens with respect to the fundus, in association with the inserting.

2. An optical tomographic imaging apparatus according to claim 1 , wherein the unit configured to compensate the change comprises a unit configured to offset a movable center of a movable range for the focus lens so as to correspond to the change in the focus position.

3. An optical tomographic imaging apparatus according to claim 2 , wherein the unit configured to offset the movable center is further configured to set an offset amount based on a diopter of the inserted optical member for changing a field angle.

4. An optical tomographic imaging apparatus according to claim 1 , wherein the unit configured to compensate the change comprises a removable optical member to be inserted into the optical system in order to cancel the change in the focus position.

5. An optical tomographic imaging apparatus according to claim 1 , further comprising a dispersion compensation unit to be inserted into an optical path of the reference light in order to cancel dispersion of a light that occurs in the optical system due to insertion of the optical member for changing a field angle.

6. An optical tomographic imaging apparatus according to claim 1 , further comprising a unit configured to correct the output signal from the detector so as to reduce influence of dispersion of a light that occurs in the optical system due to insertion of the optical member for changing a field angle.

7. An optical tomographic imaging apparatus according to claim 1 , wherein the optical member for changing a field angle comprises an eyeglass-type optical member to be attached to a subject.

8. An optical tomographic imaging apparatus according to claim 7 , wherein the unit configured to compensate the change is further configured to calculate, when offsetting a movable center of a movable range for the focus lens so as to correspond to the change in the focus position, an offset amount for the offsetting based on the attached eyeglass-type optical member, and offset the movable center of the movable range for the focus lens by the calculated offset amount.

9. An optical tomographic imaging apparatus according to claim 1 , further comprising a unit configured to insert and remove the optical member for changing a field angle into and from the optical system.

10. An optical tomographic imaging apparatus according to claim 1 , wherein the optical member for changing a field angle comprises any one of a convex lens, a meniscus lens, an eyeglass-type lens, and a contact-type lens.

11. An optical tomographic imaging apparatus according to claim 1 , wherein the optical tomographic imaging apparatus further comprises a correction unit configured to correct a distortion of the tomographic image based on an optical characteristic of the optical member for changing a field angle and an optical characteristic of a cornea of the eye to be inspected.

12. An optical tomographic imaging apparatus according to claim 1 , wherein the scanning unit is arranged at a position conjugate with an anterior ocular segment of the eye to be inspected, and is further configured to scan the fundus with the measuring light.

13. A method of controlling an optical tomographic imaging apparatus, the optical tomographic imaging apparatus comprising: (a) a light source; (b) an optical splitter configured to split a light emitted from the light source into a measuring light and a reference light; (c) a scanning unit configured to scan a fundus of an eye to be inspected with the measuring light; (d) an optical system configured to irradiate the fundus with the measuring light through the scanning unit; (e) a detector configured to receive an interference light between (1)a return light of the measuring light from the fundus and (2) the reference light; and (f) a calculation processing portion configured to process an output signal from the detector, to thereby acquire a tomographic image of the fundus, wherein the optical system comprises a focus lens configured to focus the measuring light on the fundus, the method comprising:
compensating, when an optical member for changing a field angle is inserted between the scanning unit and the fundus in order to change the field angle of an acquiring area of the tomographic image of the fundus, a change in a focus position of the focus lens with respect to the fundus, in association with the inserting.

14. A non-transitory tangible medium having recorded thereon a program for causing a computer to execute the control method for an optical tomographic imaging apparatus of claim 13 .

Assignees

• Canon Kk

Inventors

• Uji Akihito
• Yoshimura Nagahisa
• Yoshida Hirofumi
• Makihira Tomoyuki

Classifications

• A61B3/102 Primary

  for optical coherence tomography [OCT] · CPC title

• A61B3/14

  Arrangements specially adapted for eye photography · CPC title

• A61B3/0041

  characterised by display arrangements · CPC title

• A61B3/12

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