US Patent No. 9,277,858

ABERRATION CORRECTING METHOD AND ABERRATION CORRECTING APPARATUS


Patent No. 9,277,858
Issue Date March 08, 2016
Title Aberration Correcting Method And Aberration Correcting Apparatus
Inventorship Koji Nozato, Rochester, NY (US)
Kohei Takeno, Yokohama (JP)
Assignee Canon Kabushiki Kaisha, Tokyo (JP)

Claim of US Patent No. 9,277,858

1. An aberration correcting method comprising:
measuring, using an aberration measuring unit, a wavefront aberration of reflected light acquired by irradiating measurement
light on a subject, the wavefront aberration being measured as phase information at each of a plurality of aberration measurement
points of the aberration measuring unit;

measuring, using the aberration measuring unit, wavefront gradient information at each of the aberration measurement points;
and

driving an aberration correction unit having a number of pixels greater than the number of the plurality of aberration measurement
points, wherein driving the aberration correction unit comprises:

driving first pixels of the aberration correction unit positionally corresponding to the aberration measurement points based
on the phase information being measured, and

driving second pixels of the aberration correction unit not positionally corresponding to the aberration measurement points
based on (i) the phase information being measured at the aberration measurement points corresponding to each of the first
pixels in the vicinity of each of the second pixels, (ii) the gradient information being measured at aberration measurement
points corresponding to each of the first pixels in the vicinity of each of the second pixels, and (iii) a distance between
each of the first pixels in the vicinity of each of the second pixels and each of the second pixels.