Light-based epilation device and method of cosmetic hair removal

1. A method of cosmetic hair growth manipulation, comprising the steps of

providing a light-based epilation device for at least temporal hair removal comprising:

a light emission unit having a regular pattern array having rows and columns of light emission elements realized as semiconductor light emitter elements comprising LEDs, having at least two sub-groups of light emission elements, each of the sub-groups of light emission elements comprising at least one distinct light emission element, wherein the sub-groups of light emission elements are arranged for separate energizing; and

a controller unit arranged for energizing the sub-groups of light emission elements in accordance with an energizing sequence so that the light emission unit quasi-continuously emits treatment light, the energizing sequence comprising consecutive sub-sequences and where at least one sub-group is not energized at any given time instant, and where the energizing sequence comprises at least one non-energizing gap;

at least one sensor arranged for measuring a skin parameter during the non- energizing gap, wherein the at least one sensor is not influenced by light emitted by the light emission elements;

wherein the sub-groups of light emission elements are arranged as consecutive N times M sub-arrays of the array of light emission elements; and

energizing in parallel at least two adjacent sub-groups of light emission elements for a first predefined time period while another sub-group of light emission elements adjacent to one of the energized sub-groups is not energized during a first subsequence of the energizing sequence, and then

energizing in parallel at least one of the adjacent sub-groups of light emission elements energized during the first sub-sequence with the another sub-group of light emission elements for a second predefined time period while one of the sub-groups of light emission elements energized during the first sub-sequence is not energized during a second sub-sequence of the energizing sequence;

bringing a light output window of the light-based epilation device into contact with the skin of a human subject;

moving the light output window over the skin while maintaining skin contact and controlling the light-based epilation device to quasi-continuously emit light.

2. The method in accordance with claim 1 , comprising the steps of

providing the array of light emission elements in an oblong pattern and providing the sub-groups of light emission elements such that they are consecutively arranged in the longer elongation direction;

energizing adjacent sub-groups of the sub-groups of light emission elements from one end of the oblong array to the other end; and

moving the output window perpendicular to the longer elongation direction at a speed at which a repeated energizing of the sub-groups leads to an essentially gap-free illumination on the skin.

3. The method in accordance with claim 1 , comprising the steps of

providing the array of light emission elements in an oblong pattern and providing the sub-groups of light emission elements such that they are consecutively arranged in the longer elongation direction;

energizing adjacent sub-groups of the sub-groups of light emission elements from one end of the oblong array to the other end;

measuring the speed of the movement;

controlling the energizing time periods in dependence on the determined speed in order to achieve an essentially gap-free illumination on the skin.