Abstract: The invention relates to a device (1) for hair-growth control of hairs (3), in particular hairs growing from human skin (5). The device (1) has a laser source (7) for generating a laser beam (9) during a pulse time, an optical system (15) for focusing the laser beam into a focal spot (25), and a laser beam manipulator (17) for positioning the focal spot in a target position. According to the invention, a dimension of the focal spot (25) and a power of the generated laser beam (9) are such that, in the focal spot (25), the laser beam has a power density which is above a characteristic threshold value for hair-growth related skin tissue above which, for the pulse time, a laser induced optical breakdown (LIOB) phenomenon occurs in the hair-growth related skin tissue. The LIOB phenomenon results in a number of mechanical effects, such as cavitation and the generation of shock waves, which damage the hair-growth related skin tissue in positions surrounding the LIOB phenomenon.

Abstract: The invention relates to a system and method for removing hair The system comprises a hair detection device and a hair-removing device (20). Since 3D information on hairs (32) is required, but due to the very dispersed presence of, e.g., human hairs (32) on skin (30), known detection devices are too slow, the invention provides a combination of two image sensors. A first image sensor (12) produces a first image, based on which a selected part is imaged with a second image sensor (14) that provides the required 3D position information with which the hair-removing device (20) can remove the hair Thus, optimum use may be made of both fast but less accurate image sensors, such as (2D) CCDs or CMOS sensors, and accurate but slow sensors such as 3D scanning sensors.

Abstract: The invention relates to a device (1) for treating human skin by means of radiation. The device has a housing (5) with a radiation exit opening (13), a radiation source (9) which is accommodated in the housing, and a radiation path (15) between the radiation source and the radiation exit opening. A radiation filter (17) is provided in the radiation path. According to the invention the radiation filter (17) comprises water (23) which is in solid state at least during an initial phase of operation of the device (1). The water in solid state has an optical transmission spectrum which corresponds to the optical transmission spectrum of water in liquid state as present in the skin. As a result the water in solid state acts as an ideal filter for the IR light and near IR light, which would otherwise be absorbed by the water in the skin and cause unwanted heating of the skin.