The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 28, 2012
Filed:
Mar. 31, 2009
Taiki Sawabe, Tokyo, JP;
Keiji Nomaru, Tokyo, JP;
Taiki Sawabe, Tokyo, JP;
Keiji Nomaru, Tokyo, JP;
Disco Corporation, Tokyo, JP;
Abstract
A laser processing apparatus including a height detecting device for detecting the height of a workpiece held on a chuck table. The height detecting device includes an annular spot forming unit for forming the spot shape of a detecting laser beam into an annular spot shape, a pinhole mask for passing the reflected light reflected on the upper surface of the workpiece held on the chuck table, but blocking the reflected light reflected on the lower surface of the workpiece, and a reflected light analyzing unit for analyzing the reflected light passed through the pinhole mask and transmitting the result of analyzation to a control unit. The laser processing apparatus further includes a focusing unit having an objective lens for focusing a processing laser beam having a circular spot shape and the detecting laser beam having the annular spot shape and a window lens for focusing the detecting laser beam focused by the objective lens without focusing the processing laser beam.