| 摘要 |
The invention provides a hair treatment device (40) comprising a light-based detector (10) for detecting a hair (22) near a skin surface (21) and a method for detecting a hair (22) near a skin surface (21). The detector (10) comprises a light source (11), optical elements (14, 16, 17, 18) and a polarization-sensitive light sensor (12, 13). The light source (11) generates a light beam (31) and the optical elements (14, 16, 17, 18) focus the light beam (31) at a hair (22) near the skin surface (21). The polarization-sensitive light sensor (12, 13) is provided for detecting light interacted with the hair (22) or the skin surface (21) and having a predefined linear polarization. The light source (11) and/or the optical elements (14, 16, 17, 8) are arranged to cause the light beam (31), when reaching the skin surface (21), to have a polarization direction which is time-invariant and spatially variant in cross-sections of the 10 light beam. |
| 主权项 |
1. A hair treatment device comprising a light-based detector for detecting a hair near a skin surface, the detector comprising:
a light source for generating a light beam, optical elements for focusing the light beam at the hair near the skin surface, and a polarization-sensitive light sensor for detecting light interacted with the hair or the skin surface and having a predefined linear polarization,wherein the light source and/or the optical elements are arranged to cause the light beam, when reaching the hair or the skin surface, to have a polarization direction which is time-invariant and spatially variant in cross-sections of the light beam.
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