Micro-electro-mechanical device having a tiltable structure, with detection of the position of the tiltable structure
AssigneeSTMicroelectronics S.r.l.
InventorsRoberto Carminati, Enri Duqi, Sebastiano Conti
Life of this patent
Estimating the term…
Abstract
A micro-electro-mechanical device, wherein a platform is formed in a top substrate and is configured to turn through a rotation angle. The platform has a slit and faces a cavity. A plurality of integrated photodetectors is formed in a bottom substrate so as to detect the light through the slit and generate signals correlated to the light through the slit. The area of the slit varies with the rotation angle of the platform and causes diffraction, more or less marked as a function of the angle. The difference between the signals of two photodetectors arranged at different positions with respect to the slit yields the angle.
Claims20
A micro-electro-mechanical device, comprising:
- a platform configured to rotate by a rotation angle (θ);
- a slit in the platform;
- a support structure supporting the platform and including a cavity facing a first side of the platform;
- and
- a plurality of integrated photodetectors facing the cavity and the first side of the platform.
A picoprojector, comprising:
- a micro-electro-mechanical device that includes:
- a platform configured to rotate by a rotation angle (θ);
- a slit in the platform;
- a support structure supporting the platform and including a cavity facing a first side of the platform;
- and
- a plurality of integrated photodetectors facing the cavity and the first side of the platform, and configured to generate light-intensity signals;
- a light source facing a second side of the platform and configured to generate a light beam;
- and
- a processing unit configured to receive the light-intensity signals from the plurality of photodetectors and calculate the rotation angle of the platform based on the light-intensity signals.
A method, comprising:
- detecting rotation of a rotatable platform of a micro-electro-mechanical device that includes a platform configured to rotate by a rotation angle (θ), a slit in the platform, a support structure supporting the platform and including a cavity facing a first side of the platform, and a plurality of integrated photodetectors facing the cavity and the first side of the platform, the detecting including:
- sending a light beam onto a second side of the platform;
- detecting, by the photodetectors, a portion of the light beam passing through the slit in the platform;
- producing, by the photodetectors, electrical signals correlated to a light intensity of the portion of the light beam detected by the photodetectors;
- and
- processing the electrical signals to obtain the rotation angle of the platform.
Dependencies are inferred from the claim text.