Laser scanning devices and methods with touch detection
AssigneeMicrovision, Inc.
InventorChao Chen
Life of this patent
Estimating the term…
Abstract
Laser scanning devices and methods are described that provide for improved touch detection. The laser scanning devices and methods determine if an object is touching a touch surface by determining if a halo region having corresponding locally high amplitude signals is proximate to the object. The presence of such a halo region can confirm that the object is touching surface and not just hovering above the surface. Furthermore, the presence of the halo region can confirm object touching even for objects having significantly different sizes. As one example, the determined presence of the halo region can be used to reliably determine that a human finger is touching the surface even though human fingers can have significantly different sizes.
Claims20
A laser scanning device comprising:
- at least one source of laser light configured to generate a laser beam, the laser beam including detection pulses;
- at least one scanning mirror configured to reflect the laser beam;
- a drive circuit configured to provide an excitation signal to excite motion of the at least one scanning mirror to reflect the laser beam in a pattern of scan lines over a surface;
- and
- a touch detection device, the touch detection device configured to receive reflections of the detection pulses and generate amplitude signals from the received reflections, the touch detection device configured to determine if an object is touching the surface by determining if a halo region having corresponding locally high amplitude signals is proximate to the object.
A laser scanning device comprising:
- at least one source of laser light configured to generate a laser beam;
- at least one scanning mirror configured to reflect the laser beam;
- a drive circuit configured to provide an excitation signal to excite motion of the at least one scanning mirror to reflect the laser beam in a pattern of scan lines over a surface;
- a pixel drive generator, the pixel drive generator configured to control the at least one source of laser light to generate detection pulses in the pattern of scan lines;
- and
- a touch detection device, the touch detection device including:
- an optical sensor configured to receive reflections of the detection pulses and generate output signals proportional to the received reflections of the detection pulses,
- a signal detector and demodulator configured to generate a timing signal proportional to time of flight of received reflections of the detection pulses and an amplitude signal proportional to intensity of the received reflection;
- and
- a processor configured to generate a 3-dimensional point cloud based at least in part on the timing signal, the processor further configured to analyze the 3-dimensional point cloud to locate objects proximate to the surface, and wherein the processing device is further configured to determine if a located object is touching the surface determining if a halo region having corresponding locally high amplitude signals and having a width corresponding to a typical finger width is proximate to the object.
A method of detecting a touch on a surface, the method comprising:
- generating a laser beam, the laser beam including detection pulses;
- reflecting the laser beam with at least one scanning mirror;
- exciting motion of the at least one scanning mirror to reflect the laser beam in a pattern of scan lines on the surface;
- receiving reflections of the detection pulses from the surface;
- locating objects proximate to the surface based at least in part on the received reflections of the detection pulses;
- and determining if a located object is touching the surface by determining if a halo region having corresponding locally high amplitude signals is proximate to the located object.
Dependencies are inferred from the claim text.