Abstract: The embodiments described herein provide scanning laser devices that include an output optic configured to reduce image distortion. Specifically, the output optic is configured to reduce the distortions that could otherwise occur at relatively short projection distances, while also providing good image quality at relatively long projection distances. In general, the output optic includes a prism having a first surface, a second surface, and a third surface. The prism is configured such that the laser light interacts with each of these three surfaces while being transmitted through the prism and outputted to the display surface. The first, second, and third surfaces are each formed to have a freeform rotationally asymmetric shape, and these freeform rotationally asymmetric shapes are configured to work together to correct distortion in projected images.

Abstract: A scanning projector includes one or more scanning mirrors that reflect a light beam to create an image. The beam is created by multiple laser light sources, at least two of which create light at substantially the same color. The multiple laser light sources are used alternately to illuminate successive pixels, lines, and/or frames. Speckle reduction is achieved because of spatial overlap of the light beams produced by the multiple laser light sources.

Abstract: Devices and methods are described herein that use a first solid figure element, a polarizing beam splitter, and a second solid figure element or array of mirrors to reduce speckle in projected images. Specifically, laser light is generated and split into two portions having orthogonal polarizations. The first portion of laser light is reflected in the second solid figure element or the array of mirrors and is then spatially recombined with the second portion of laser light in the first solid figure element. The difference in path length followed by the two portions generates a temporal incoherence in the recombined laser light beam, and that temporal incoherence reduces speckle in the projected image.

Abstract: A scanning projector and method is provided that generates a feedback signal from at least one photodetector. In the scanning projector, a scanning mirror is configured to reflect laser light into an image region and an over scanned region. The at least one photodetector is configured to receive a portion of the reflected laser light impacting the over scanned region, and provides the feedback signal responsive to the received portion of light. This feedback signal can then be used to provide precise control of the scanning mirror.

Abstract: A laser drive circuit compensates for laser diode dynamics. A compensation value is determined from a sum of weighted basis functions. The basis functions may be a function of current desired optical powers and/or past desired optical powers. The weights may be updated periodically based at least in part on accumulated basis function outputs and measured optical powers.

Abstract: A scanning projector and method is provided that that uses at least one multi-stripe laser to generate the laser light for the scanned image. Specifically, the multi-stripe laser includes at least a first laser element and a second laser element formed together on a semiconductor die. The first laser element is configured to output a first laser light beam, and the second laser element is configured to output a second laser light beam. At least one scanning mirror is configured to reflect the first laser light beam and the second laser light beam, and a drive circuit is configured to provide an excitation signal to excite motion of the at least one scanning mirror. Specifically, the motion is excited such that the at least one scanning mirror reflects the first laser light beam and the second laser light beam in a raster pattern of scan lines.

Abstract: A projection system emits light pulses in a field of view and measures properties of reflections. Properties may include time of flight and return amplitude. Foreground objects and background surfaces are distinguished, distances between foreground objects and background surfaces are determined based on reflections that are occluded by the foreground objects and other properties of the projection system.

Abstract: Briefly, in accordance with one or more embodiments, a MEMS scanned beam projector includes a light source to emit a light beam, a scanning platform to redirect the light beam impinging on the platform, and a display controller to control the light source and the scanning platform to cause the scanning platform to scan the light beam in a vertical direction and a horizontal direction in a scan pattern to project an image onto a projection surface. The display controller is configured to correct for image distortion in the projected image by providing a compensated drive signal to the scanning platform to compensate for the image distortion.

Abstract: Devices and methods are described herein that use a first solid figure element, a polarizing beam splitter, and a second solid figure element to reduce speckle in projected images. Specifically, laser light is generated and split into two portions having orthogonal polarizations. The first portion of laser light is internally reflected off at least three internal faces of the second solid figure element and is then spatially recombined with the second portion of laser light in the first solid figure element. The difference in path length followed by the two portions generates a temporal incoherence in the recombined laser light beam, and that temporal incoherence reduces speckle in the projected image.

Abstract: The embodiments described herein provide microelectromechanical system (MEMS) scanners with increased resistance to distortion in the mirror surface. Such MEMS scanners, when incorporated into laser scanning devices, are used to reflect laser light into a pattern of scan lines. Thus, by reducing distortion in the scanning surface these MEMS scanners can provide improved performance in scanning laser devices, including scanning laser projectors and laser depth scanners. In general, this is accomplished by providing a MEMS scanner where the connection to the scan plate is made at an intermediate support structure, and at a point on that intermediate support structure that is offset from the scanning surface. Providing the connection to the scan plate at points offset from the scanning surface can reduce the distortion that occurs in the scanning surface as a result of rotational forces in the MEMS scanner.

Abstract: Devices and methods are described that provide for scanning surfaces and generating 3-dimensional point clouds that describe the depth of the measured surface at each point. In general, the devices and methods utilize scanning mirror(s) that reflect a laser beam into a pattern of scan lines. When the raster pattern of scan lines is directed at a surface, reflections of the laser beam from the surface are received and used to the generate 3-dimensional point clouds that describe the measured surface depth at each point. The motion of the scanning mirror(s) can be dynamically adjusted to modify the characteristics of the resulting 3-dimensional point cloud of the surface. For example, the adjustment of the scanning mirror motion can modify the resolution or data density of the resulting 3-dimensional point cloud that describes the measured depths of the surface.

Abstract: A multi-beam apparatus for observing a sample with high resolution and high throughput and in flexibly varying observing conditions is proposed. The apparatus uses a movable collimating lens to flexibly vary the currents of the plural probe spots without influencing the intervals thereof, a new source-conversion unit to form the plural images of the single electron source and compensate off-axis aberrations of the plural probe spots with respect to observing conditions, and a pre-beamlet-forming means to reduce the strong Coulomb effect due to the primary-electron beam.

Abstract: A scanning display system includes hybrid data acquisition. Data can be acquired in a time-of-flight mode, or in a non-time-of-flight mode. Infrared light pulses may be used in both modes. The infrared light pulses may have different characteristics. Time-of-flight data acquisition and non-time-of-flight data acquisition may be used sequentially or simultaneously.

Abstract: Devices and methods are described herein to measure optical power in scanning laser projectors. In general, the devices and methods utilize a filter component and photodiode to measure optical power being generated by at least one laser light source, with the filter component configured to at least partially compensate for the non-uniform electric current response of the photodiode. Such a configuration facilitates accurate optical power measurement using only one photodiode, and thus can facilitate accurate optical power measurement in a relatively compact device and with relatively low cost.

Abstract: Devices and methods are described that provide for scanning surfaces and generating 3-dimensional point clouds that describe the depth of the measured surface at each point. In general, the devices and methods utilize scanning mirror(s) that reflect a laser beam into a pattern of scan lines. When the raster pattern of scan lines is directed at a surface, reflections of the laser beam from the surface are received and used to the generate 3-dimensional point clouds that describe the measured surface depth at each point. The motion of the scanning mirror(s) can be dynamically adjusted to modify the characteristics of the resulting 3-dimensional point cloud of the surface. For example, the adjustment of the scanning mirror motion can modify the resolution or data density of the resulting 3-dimensional point cloud that describes the measured depths of the surface.

Abstract: A scanning projector includes a MEMS device with a scanning mirror that sweeps a beam in two dimensions. Actuating circuits receive scan angle information and provide signal stimulus to the MEMS device to control the amount of mirror deflection on two axes. The scan angle information may be modified to maintain a constant image size, a constant image brightness, and/or to correct for keystone distortion.

Abstract: Scanning platforms for use in scanning laser devices are described herein. These scanning platforms are particularly applicable to scanning laser devices that use microelectromechanical system (MEMS) structures to facilitate mirror motion. The scanning platforms include a centrally located stationary mount portion and a movable portion that surrounds the stationary portion. The movable portion is configured to be coupled to a mirror and to facilitate motion of that mirror. Such a scanning platform can facilitate reduced size in scanning mirror assembly, and thus can facilitate a more compact scanning laser device.

Abstract: A scanning projector includes a programmable voltage source to provide a programmable voltage to a laser light source. A look-ahead circuit determines future voltage requirements by finding peaks in future pixel data. The programmable voltage may change for each frame of video, for each line of video, or multiple times within each line of video.

Abstract: A scanning projector and method is provided that generates a feedback signal from at least one photodetector. In the scanning projector, a scanning mirror is configured to reflect laser light into an image region and an over scanned region. The at least one photodetector is configured to receive a portion of the reflected laser light impacting the over scanned region, and provides the feedback signal responsive to the received portion of light. This feedback signal can then be used to provide precise control of the scanning mirror.

Abstract: Laser light pulses are reflected off a scanning mirror. A time-of-flight distance measurement device receives reflected light pulses and determines distances. The light pulses have abrupt changes in amplitude. Reflected pulses are differentiated to reduce sensitivity to amplitude variations. Differentiated pulses may be compressed to keep the receiver from saturating. Distance measurements are combined with location information to produce a 3D image of a surface.