Method and apparatus for aligning target object
AssigneeOlympus Optical Co., Ltd.
InventorsYasutada Miura, Shunsuke Kurata
Life of this patent
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Abstract
In an optical device having an objective lens for magnifying an image of a target object and a focusing unit including a laser source for irradiating the target object through the objective lens and a focus detecting light-receiving section for receiving light reflected from the target object, positions in the periphery of the target object are detected by using the laser beam emitted from the laser source of the focusing unit while changing a relative positional relationship between the target object and the objective lens.
Claims18
An apparatus for aligning a target object, comprising:
- an objective lens for magnifying an image of the target object;
- focusing means including a laser source for irradiating the target object through the objective lens and a focus detecting light-receiving section for receiving light reflected from the target object, the focusing means being used for detecting a defocus from a detection result of the focus detecting light-receiving section to execute focusing;
- displacing means for changing a relative positional relationship between the target object and the objective lens such that a laser beam is emitted from the laser source of the focusing means to at least three points of a periphery of the target object;
- a rotary table for holding the target object;
- edge detecting means for detecting edge positions corresponding to at least three points excluding an orientation flat or a notch in the periphery of the target object, using the laser beam emitted from the laser source of the focusing means;
- and
- operating means for calculating a displacement of a central position of the target object from an axis-of-rotation position of the rotary table based on the edge positions detected by the edge detecting means.
A method of aligning a target object applied to an optical device having an objective lens for magnifying an image of the target object, the method comprising the steps of:
- stopping a focusing function of an autofocus unit;
- irradiating the target object with a laser beam from a laser source provided in the autofocus unit through the objective lens while varying a relative positional relationship between the target object and the objective lens;
- detecting edge positions corresponding to at least three points excluding an orientation flat or a notch in a periphery of the target object, based on a variation of amounts of light reflected from the target object in a focus detecting light-receiving section provided in the autofocus unit;
- calculating a central position of the target object based on the detected edge portions;
- and
- positioning the target object based on the calculated central position.
Dependencies are inferred from the claim text.