| 摘要 |
A bar code reader includes a light emitting element, a movable mirror operative, by oscillation, to reflect outgoing light from the light emitting element to cause reflected light to scan an object to be illuminated and to further reflect the reflected light of the outgoing light having illuminated the object, and a light receiving element arranged to detect the reflected light reflected off the movable mirror and convert a detected beam into an electrical signal. The movable mirror comprises a glass substrate and a dielectric multilayer film laminated on the glass substrate. The dielectric multilayer film is formed by alternating layers of a high refractive index material and a low refractive index material at an optical thickness lambd/4, where lambd is the wavelength of the outgoing light.
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