Two-dimensional motion sensor
AssigneeCypress Semiconductor Corporation
InventorsJahja I. Trisnadi, Clinton B. Carlisle, Robert J. Lang
Life of this patent
Estimating the term…
Abstract
An optical sensor and method of using the same is provided for sensing relative movement between the sensor and a surface by detecting changes in optical features of light reflected from the surface. In one embodiment, the sensor includes a two dimensional array of photosensitive elements, the array including at least a first plurality of photosensitive elements arranged and coupled to sense a first combined movement along a first set of at least two non-parallel axes, and a second plurality of photosensitive elements arranged and coupled to sense a second combined movement along a second set of a least two non-parallel axes.
Claims20
An optical sensor for sensing relative movement between the sensor and a surface by detecting changes in optical features in a pattern of light reflected from the surface, the sensor including a two dimensional (2D) array of photosensitive elements comprising at least:
- a first plurality of photosensitive elements arranged and coupled to select a 2D spatial frequency of the pattern created by light reflected from the surface and to generate in response thereto a first signal which is a function of movements along a first set of at least two non-parallel axes by algebraically combining outputs from each of the first plurality of photosensitive elements;
- and
- a second plurality of photosensitive elements arranged and coupled to select a 2D spatial frequency of the pattern created by light reflected from the surface and to generate in response thereto a second signal which is a function of movements along a second set of at least two non-parallel axes by algebraically combining outputs from each of the second plurality of photosensitive elements.
An optical sensor for sensing relative movement between the sensor and a surface by detecting changes in optical features of light reflected from the surface, the sensor including a two dimensional (2D) array of photosensitive elements, the array comprising at least:
- a first plurality of photosensitive elements arranged and coupled to generate a first analog signal in response to light reflected thereon from the surface which is a function of movements along a first set of at least two non-parallel axes by algebraically combining outputs from each of the first plurality of photosensitive elements;
- and
- a second plurality of photosensitive elements arranged and coupled to generate a second analog signal in response to light reflected thereon from the surface which is a function of movements along a second set of at least two non-parallel axes by algebraically combining outputs from each of the second plurality of photosensitive elements.
A method of sensing displacement of an optical sensor relative to a surface, the optical sensor comprising a two-dimensional (2D) array including at least a first plurality of photosensitive elements and a second plurality of photosensitive elements, the method comprising steps of:
- illuminating a portion of the surface;
- receiving light reflected from the illuminated portion of the surface on the 2D array;
- sensing with the first plurality of photosensitive elements movement in at least two directions and generating in response thereto a first signal which is a function of movements along a first set of at least two non-parallel axes by algebraically combining outputs from each of the first plurality of photosensitive elements;
- sensing with the second plurality of photosensitive elements movement in at least two directions and generating in response thereto a second signal which is a function of movements along a second set of at least two non-parallel axes by algebraically combining outputs from each of the second plurality of photosensitive elements;
- and
- combining the first and second signals to produce output signals representing relative movement between the sensor and the surface.
Dependencies are inferred from the claim text.