A laser shaving device having an improved hair detector
Publication Date: 2005-Mar-02
The IP.com Prior Art Database
Titel: A laser shaving device having an improved hair detector
In a laser shaving device a focused laser beam is used to cut a hair. An advantage of a laser shaving device is that hairs can be cut below skin level, so that a very smooth shaving result is obtained. A laser shaving device comprises a hair detecting system to detect the positions of the hairs in and/or on the skin, a processor to determine the target position of the focus of the laser beam based upon the output of the hair detecting system, and a laser beam manipulator to position the focus of the laser beam in the desired target position.
To detect the positions of the hairs alternative systems can be used. An example is an image detector, such as a CCDor a CMOS image sensor that detects a n image of a portion of the skin. From said image the processor determines the positions of the hairs using for example an image recognition algorithm. Another example is a 3D scanning system, such as is known for example from a confocal laser scanning microscope.
In order to improve the efficiency and reliability of the hair detecting system a technical measure is taken to improve the contrast between hairs and skin. In particular the light emitted by the hair detecting system to illuminate or scan the skin is polarized in a first direction, and the light which returns from the skin is polarized in a second direction orthogonal to the first direction before being detected. In this way, the portion of the light...