Patent ID: 7695139

Claim:
An alignment device for an ophthalmic measurement apparatus, comprising: an index projection optical system that forms a plurality of indices on a cornea of an eye to be examined by projecting a plurality of index lights onto said cornea; an imaging optical system that forms the images of said plurality of indices on an imaging device as index images; a three-dimensional driving device for driving said imaging optical system in a three-dimensional direction; and a controlling device for controlling to drive said three-dimensional driving device, said controlling device, based on the positions of the index images formed on said imaging device, controlling to drive said imaging optical system vertically and horizontally by said three-dimensional driving device such that a cornea vertex position of the image of said eye to be examined, which is formed on said imaging device, moves toward the center of the imaging device, wherein said imaging optical system allows said imaging device to detect reflected lights of said plurality of index lights reflected by said cornea, and said controlling device controls to drive said three-dimensional driving device such that average light quantity values become approximately equal in a plurality of photo-detecting sections of said imaging device where said reflected lights are detected, wherein said plurality of photo-detecting sections are arranged in a plurality of photo-detecting regions that said controlling device formed by dividing an image captured by said imaging device, and said controlling device calculates the average light quantity values of said reflected lights by each of said detecting regions, compares the calculated average light quantity values of each detecting region with each other, and controls to drive said three-dimensional driving device in a direction where an average light quantity value in a detecting region having a low average light quantity value becomes higher.