Patent ID: 11924938
Assignee: MITUTOYO CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. An illuminator comprising:
a light emitter comprising a light-emitting diode;
a temperature sensor configured to detect a current temperature of the light emitter;
and an illumination controller configured to adjust a drive voltage being supplied to the light emitter in accordance with the current temperature such that a brightness of the light emitter is constant, wherein
the illumination controller is further configured to adjust the drive voltage being supplied to the light emitter by a predetermined ratio,
the illumination controller has a reference temperature stored therein in advance, the illumination controller being configured to compare the current temperature and the reference temperature to adjust the drive voltage, and
the reference temperature is updated with a new current temperature every time the drive voltage is adjusted.