Optical micro-projection system and projection method

A projection method for optical micro-projection system comprising the steps of:

• a) providing at least one light source coupled to at least one movable MEMS micro-mirror for deviating light from said light source to allow generation of images on a projection surface;
• b) receiving light deviated by said MEMS micro-mirror and reflected by said projection surface with at least one photodiode;
• c) with a distance evaluation circuit, evaluating a distance between the projection source and a projection surface based on the output of said photodiode and for detecting a change in the evaluated distance, due to one or more variations on portions of the projection surface which is/are at different distances from the projection source;
• d) adjusting the at least one light source and the at least one movable MEMS mirror, according to the distance evaluated by the distance evaluation circuit, such that an image projected by the optical micro-projection system is modified to compensate for said variations on a projection surface so that an undistorted image can be projected on the projection surface, and such that a property of the image projected by the optical micro-projection system, other than the intensity of the image, is modified in response to a direct physical interaction of a user with a part of the projected image.

An optical micro-projection system comprising the following components:

• at least one light source;
• at least one movable MEMS mirror for deviating light from said light source to allow generation of images on a projection surface;
• at least one photodiode for receiving light reflected by said projection surface;
• a distance evaluation circuit for evaluating a distance between the projection source and a projection surface based on light deviated by said MEMS mirror and received by said photodiode, and for detecting a change in the evaluated distance, due to one or more variations on portions of the projection surface which is/are at different distances from the projection source, wherein the optical micro-projection system further comprises,
• a means to adjust the at least one light source and/or the at least one movable MEMS mirror, according to the distance evaluated by the distance evaluation circuit, such that an image projected by the optical micro-projection system can be modified to compensate for said variations on a projection surface so that an undistorted image can be projected on the projection surface, and such that a property of the image projected by the optical micro-projection system, other than the intensity of the image, can be modified in response to a direct physical interaction of a user with a part of the projected image,
• wherein said circuit comprises a self-mixing module and an optical power variation counter for counting optical power variations in light reflected from the projection surface, and wherein the self-mixing module is configured to adjust the light source to compensate for optical power variations.