Optical system evaluation apparatus, optical system evaluation method and program thereof

Abstract

An apparatus (100) is for evaluating optical characteristics of an optical system (7a) based on an image forming position of a point image formed through the optical system (7a). The apparatus (100) includes a point image producing unit (1 to 4; 4b) that forms a point image through the optical system (7a) in each point light source; an imaging unit (10) that images the point images to produce a point image distribution image; and a moving unit (5) that changes relative distance between the optical system (7a) and the point light source or the imaging unit (10) in an optical axis direction (9).; The apparatus (100) also performs processing of detecting an image forming position in each different relative distance of the point image based on image information of the point image distribution images, the processing including calculating a regression expression for the detected image forming positions to obtain a shape parameter of the image axis in each of the point images.

Description

[0001] References to related applications [0002] This application claims priority from Japanese Patent Application No. 2007-124682 filed on May 9, 2007 and incorporates the entire contents thereof. technical field [0003] The present invention relates to an optical system evaluation device, an optical system evaluation method, and an optical system evaluation program for evaluating optical characteristics of an evaluation object optical system based on an imaging position of a point image formed through the evaluation object optical system. Background technique [0004] In general, when an image captured using an optical system is used for length measurement, a high degree of telecentricity (telecentricity) is required in the optical system. The so-called telecentricity means that the chief ray on the object side or the image side is parallel to the optical axis regardless of the distance from the optical axis. For example, in a length measuring microscope, an object-sid...

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Problems solved by technology

[0010] However, like the above-mentioned conventional optical system evaluation device, there is the following problem: the imaging position of the point image corresponding to one hole is obtained and the image plane In this method that is repeated at multiple positions in the interior, it is necessary to use some length measuring machine to monitor the position of the hole and the position of the magnifying optical system for point image observation, corresponding to the measurement accuracy of the length measuring machine, and the optical characteristics Decrease in evaluation accuracy

In addition, there is also the following problem: in order to measure while moving one hole, it takes a lot of time to measure the entire range of the field of view, and it is difficult to ensure the stability of the optical system of the evaluation object and the optical system evaluation device during the period. , the evaluation accuracy decreases

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