| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an automatic adjustment method of an opposite plane parallelism measuring device, which allows automatic adjustment of an oscillation wavelength of a laser diode LD and prevents human errors and deviations due to personal differences.SOLUTION: An opposite plane parallelism measuring device 1 comprises: a light source 12 using an LD; an interference optical system 18 guiding, from the light source, parallel light respectively to a pair of measured surfaces 41, 42 arranged facing each other, and guiding interference images formed by irradiating the measured surfaces with the parallel light from respective measured surface directions through optical paths different from each other; and imaging means 19, 20 imaging the interference images guided through the optical paths. An LD driving current generating an interference fringe at the clearest contrast is acquired from the obtained interference images. The LD driving current is saved as the LD driving current of a first image, and an LD driving current acquired by shifting the interference fringe by one fringe is saved as the LD driving current of the last image. A portion between the LD driving current of the first image and the LD driving current of the last image is equally divided to acquire an LD driving current of an intermediate image.</p> |
