| 摘要 |
The invention relates to a light source (1) comprising one or more light-emissive elements (4) and photosensitive means (P) for detecting light from one or more of said light-emissive elements and first polarization means (30) with a first polarization direction, wherein said first polarization means is provided on or over said photo-sensitive means. The first polarization means may be interposed substantially between said light-emissive element and said photo-sensitive means. Preferably, the light source further comprises second polarization means (32) with a second polarization direction perpendicular to said first polarization direction. In this arrangement, the light-emissive element (4) is interposed substantially between the first polarization means (30) and the second polarization means (32). Accordingly, the environmental light will not hit the photosensitive means and accurate optical feedback can be accomplished.
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