Patent ID: 11945214
Assignee: SEIKO EPSON CORPORATION
Field: Measurement (Instruments)
Classification: CPC B  G | IPC B  G

Claim 3:
4. The processing device according to claim 1, comprising:
a second light shielding portion configured to block light emitted from the second light source, wherein
light emitted from the second light source advances through a second detection optical path, along which the light is incident on the second light receiving portion by being reflected by the medium supported by the support portion, or a second reference optical path, along which the light is incident on the second light receiving portion without being reflected by the medium supported by the support portion, and
the second light shielding portion is configured to be switched between:
a third state of shielding the second reference optical path without shielding the second detection optical path; and
a fourth state of shielding the second detection optical path without shielding the second reference optical path.