US 7,443,516 B2Granted

Optical-distortion correcting apparatus and optical-distortion correcting method

AssigneeFujitsu Limited

InventorsFumiyuki Takahashi, Takashi Fuse, Hiroyuki Tsukahara

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Abstract

A reference-height calculating unit calculates an original height of a distortion detecting mirror when a distortion detecting mirror and a reference mirror are set in parallel to each other. A height measuring unit measures mirror heights when the distortion detecting mirror is tilted in directions of an X axis and a Y axis. A contour-line calculating unit calculates a pair of contour lines based on the mirror heights. An intersection calculating unit calculates an intersection of the contour lines. A storing unit stores coordinates to which height of predetermined coordinates are moved by distortion in a correction table. A distortion correcting unit corrects the distortion based on the correction table.

Claims9

Dependent claims

An apparatus for correcting optical distortion, in an optical image that is caused due to distortion in an optical system imaging the optical image comprising:

a distortion detecting mirror;
a reference mirror that generates an interfering light interfering with light reflected from the distortion detecting mirror by reflecting the light from the light source;
a mirror control unit that controls a relative angle between an imaginary plane substantially perpendicular to a surface of the reference mirror and a surface of the distortion detecting mirror;
a reference surface determining unit that determines a reference surface corresponding to a height of the distortion detecting mirror when the mirror control unit sets the relative angle to zero in substance;
a distortion detecting unit that detects the optical distortion corresponding to a measurement height of the surface of the distortion detecting mirror by measuring relative heights of respective lattice points on the surface of the distortion detecting mirror from the reference surface determined by the reference surface determining unit, based on interference between the light reflected from the distortion detecting mirror and the interfering light generated by the reference mirror when the mirror control unit sets the relative angle to an angle other than zero;
and
a correcting unit that corrects the optical distortion detected by the distortion detecting unit.

4 more elements

A method of correcting optical distortion, in an optical image that is caused due to distortion in an optical system imaging the optical image comprising:

controlling a relative angle between an imaginary plane substantially perpendicular to a surface of a reference mirror and a surface of a distortion detecting mirror, the distortion detecting mirror reflecting light from a light source and the reference mirror generating an interfering light interfering with light reflected from the distortion detecting mirror by reflecting the light from the light source mirror;
determining a reference surface corresponding to a height of the distortion detecting mirror when the relative angle is substantially zero;
setting the relative angle to an angle other than zero;
detecting the optical distortion corresponding to a measurement height of the surface of the distortion detecting mirror by measuring relative heights of respective lattice points on the surface of the distortion detecting mirror from the reference surface based on interference between the light reflected from the distortion detecting mirror and the interfering light generated by the reference mirror;
and
correcting the optical distortion detected.

3 more elements

A computer-readable recording medium that stores therein a computer program for correcting optical distortion in an optical image that is caused due to distortion in an optical system imaging the optical image, the computer program making a computer execute:

controlling a relative angle between an imaginary plane substantially perpendicular to a surface of a reference mirror and a surface of a distortion detecting mirror, the distortion detecting mirror reflecting light from a light source and the reference mirror generating an interfering light interfering with light reflected from the distortion detecting mirror by reflecting the light from the light source mirror;
determining a reference surface corresponding to a height of the distortion detecting mirror when the relative angle is substantially zero;
setting the relative angle to an angle other than zero;
detecting the optical distortion corresponding to a measurement height of the surface of the distortion detecting mirror by measuring relative heights of respective lattice points on the surface of the distortion detecting mirror from the reference surface based on interference between the light reflected from the distortion detecting mirror and the interfering light generated by the reference mirror;
and
correcting the optical distortion detected.

3 more elements

Dependencies are inferred from the claim text.