Patent ID: 11935765
Assignee: DISCO CORPORATION
Field: Machine tools (Mechanical engineering)
Classification: CPC H  B | IPC B  H

Claim 0:
1. A laser processing apparatus comprising:
a chuck table configured to hold a wafer;
a laser irradiating unit configured to perform laser processing by irradiating the wafer held on the chuck table with a laser beam;
a feed mechanism configured to processing-feed the chuck table and the laser irradiating unit relative to each other;
a main imaging unit configured to image a region to be laser-processed;
an auxiliary imaging unit; and
a display unit, wherein
the auxiliary imaging unit includes
an objective lens,
a camera configured to generate an image via the objective lens,
a half-silvered mirror disposed between the camera and the objective lens,
a light source configured to illuminate the wafer held on the chuck table via the half-silvered mirror and the objective lens,
a first polarizing plate disposed between the camera and the half-silvered mirror, and
a second polarizing plate disposed between the light source and the half-silvered mirror, and

the second polarizing plate is disposed such that a polarization plane of light applied from the light source, passed through the second polarizing plate, and reflected by the half-silvered mirror is rotated by a required angle with respect to a polarization axis of the first polarizing plate.