Abstract: The disclosure provides different time of flight, ToF, methods and systems for using two or more non-sinusoidal control signals to achieve modulated output light and/or image sensor control with reduced harmonic content. In particular, the two or more non-sinusoidal control signals have different relative phase offsets or duty cycle ratios such that a combined signal resulting from combing the two or more control signals has reduced harmonic content. By utilising non-sinusoidal signals and effectively making using of the combined signal for the output light and/or image sensor control, the system is more straightforward and lower cost to implement compared with systems that use sinusoidal control signals, whilst still maintaining accuracy of the system by minimising the harmonic noise normally associated with non-sinusoidal signals.

Abstract: A time-of-flight (ToF) transmitter with self-stabilized optical output phase with minimal overhead is described, where the transmitter may either function as a slave in that the laser pulse phase and width can be controlled by the master ToF receiver, or it can function as a master where the laser control pulse is generated on the same chip or a companion chip. When the ToF transmitter functions as a slave and receives the laser pulse control signal, the techniques of this disclosure can transform the receive path and the pre-driver circuit into part of a delay locked loop (DLL).

Abstract: Monitoring temperature of a laser diode and adjusting usage of the laser diode based on the monitoring information. The method of monitoring includes using a laser driver circuit to drive the laser diode to deliver multiple test current stimuli at different times related to the laser driver issuing one or a burst of illumination pulses. A differential measurement can be made between at least two of the test current stimuli. The differential measurement can be used to determine an indication of the heating or health of the laser diode in the system or of the laser system as a whole.

Abstract: The present disclosure provides numerous applications for the use of liquid crystal polarization gratings (LCPGs) to controllably steer light. When combined with an image sensor, light generated or reflected from different fields of view (FOV) can be steered, allowing an increase in the FOV or the resolution of the image. Further, the LCPG can stabilize the resulting image, counteracting any movement of the image sensor. The combination of LCPGs and liquid crystal waveguides (LCWGs) allows fine deflection control of light (from the LCWG) over a wild field of view (from the LCPG). Further applications of LCPGs include object tracking and the production of depth images using multiple imaging units and independently steered LCPGs. The LCPG may be used in controlling both the projection and reception of light.

Abstract: Time of Flight (ToF) image processing methods include collecting correlation samples to calculate a phase estimate. Systems and methods are provided for collecting correlation samples from multiple pixels. An image processing system for continuous waves includes a light source configured to emit light, an image sensor having a plurality of pixels, and a processor configured to collect correlation samples from a subset of the plurality of pixels in the image sensor.

Abstract: An image processing system for time-of-flight depth imaging includes a processor for determining depth measurements using different modes of operation. The processor determines depth measurements in a first set of frames using a second set of frames. The first mode is a continuous wave modulation mode without depth linearization and the second mode is a continuous wave modulation mode with depth linearization. The depth estimates collected in the second mode using depth linearization are used to correct the depth estimates collected in the first mode.

Abstract: Time of Flight (ToF) image processing systems and methods for proximity detection are disclosed. In particular, use of a separate proximity detector can be eliminated by using the time of flight image processing system as disclosed herein. In particular, the time of flight image processing system has two modes: a low resolution proximity detection mode and a high resolution imaging mode.

Abstract: Depth imagers can implement time-of-flight operations to measure depth or distance of objects. A depth imager can emit light onto a scene and sense light reflected back from the objects in the scene using an array of sensors. Timing of the reflected light hitting the array of sensors gives information about the depth or distance of objects in the scene. In some cases, corrupting light that is outside of a field of view of a pixel in the array of sensors can hit the pixel due to internal scattering or internal reflections occurring in the depth imager. The corrupting light can corrupt the depth or distance measurement. To address this problem, an improved depth imager can isolate and measure the corrupting light due to internal scattering or internal reflections occurring in the depth imager, and systematically remove the measured corrupting light from the depth or distance measurement.

Abstract: Optical systems can emit train(s) of light pulses onto objects to derive a distance between the light source and the object. Achieving meter or centimeter resolution may require very short light pulses. It is not trivial to design a circuit that can generate narrow current pulses for driving a diode that emits the light pulses. An improved driver circuit has a pre-charge path comprising one or more inductive elements and a fire path comprising the diode. Switches in the driver circuit are controlled with predefined states during different intervals to pre-charge current in the one or more inductive elements prior to flowing current through the fire path to pulse the diode.

Abstract: A time-of-flight (ToF) transmitter with self-stabilized optical output phase with minimal overhead is described, where the transmitter may either function as a slave in that the laser pulse phase and width can be controlled by the master ToF receiver, or it can function as a master where the laser control pulse is generated on the same chip or a companion chip. When the ToF transmitter functions as a slave and receives the laser pulse control signal, the techniques of this disclosure can transform the receive path and the pre-driver circuit into part of a delay locked loop (DLL).

Abstract: The present disclosure provides numerous applications for the use of liquid crystal polarization gratings (LCPGs) to controllably steer light. When combined with an image sensor, light generated or reflected from different fields of view (FOV) can be steered, allowing an increase in the FOV or the resolution of the image. Further, the LCPG can stabilize the resulting image, counteracting any movement of the image sensor. The combination of LCPGs and liquid crystal waveguides (LCWGs) allows fine deflection control of light (from the LCWG) over a wild field of view (from the LCPG). Further applications of LCPGs include object tracking and the production of depth images using multiple imaging units and independently steered LCPGs. The LCPG may be used in controlling both the projection and reception of light.

Abstract: An image processing system for time-of-flight depth imaging includes a processor for determining depth measurements using different modes of operation. The processor determines depth measurements in a first set of frames using a second set of frames. The first mode is a continuous wave modulation mode without depth linearization and the second mode is a continuous wave modulation mode with depth linearization. The depth estimates collected in the second mode using depth linearization are used to correct the depth estimates collected in the first mode.

Abstract: Time of Flight (ToF) image processing methods include collecting correlation samples to calculate a phase estimate. Systems and methods are provided for collecting correlation samples from multiple pixels. An image processing system for continuous waves includes a light source configured to emit light, an image sensor having a plurality of pixels, and a processor configured to collect correlation samples from a subset of the plurality of pixels in the image sensor.

Abstract: Time of Flight (ToF) image processing systems and methods for proximity detection are disclosed. In particular, use of a separate proximity detector can be eliminated by using the time of flight image processing system as disclosed herein. In particular, the time of flight image processing system has two modes: a low resolution proximity detection mode and a high resolution imaging mode.

Abstract: Depth imagers can implement time-of-flight operations to measure depth or distance of objects. A depth imager can emit light onto a scene and sense light reflected back from the objects in the scene using an array of sensors. Timing of the reflected light hitting the array of sensors gives information about the depth or distance of objects in the scene. In some cases, corrupting light that is outside of a field of view of a pixel in the array of sensors can hit the pixel due to internal scattering or internal reflections occurring in the depth imager. The corrupting light can corrupt the depth or distance measurement. To address this problem, an improved depth imager can isolate and measure the corrupting light due to internal scattering or internal reflections occurring in the depth imager, and systematically remove the measured corrupting light from the depth or distance measurement.

Abstract: Optical systems can emit train(s) of light pulses onto objects to derive a distance between the light source and the object. Achieving meter or centimeter resolution may require very short light pulses. It is not trivial to design a circuit that can generate narrow current pulses for driving a diode that emits the light pulses. An improved driver circuit has a pre-charge path comprising one or more inductive elements and a fire path comprising the diode. Switches in the driver circuit are controlled with predefined states during different intervals to pre-charge current in the one or more inductive elements prior to flowing current through the fire path to pulse the diode.

Abstract: An optical emitter package is disclosed. The optical emitter package can include a carrier, a switching die, and an optical emitter die mounted to the carrier. The optical emitter die can be directly electrically and mechanically connected to the carrier with a conductive adhesive. An energy storage device can be mounted to the carrier. The energy storage device can be directly electrically and mechanically connected to the carrier with a second conductive adhesive. The carrier can provide electrical communication between the switching die, the optical emitter die, and the energy storage device.

Abstract: Optical systems can emit train(s) of light pulses onto objects to derive a distance between the light source and the object. Achieving meter or centimeter resolution may require very short light pulses. It is not trivial to design a circuit that can generate narrow current pulses for driving a diode that emits the light pulses. An improved driver circuit has a pre-charge path comprising one or more inductive elements and a fire path comprising the diode. Switches in the driver circuit are controlled with predefined states during different intervals to pre-charge current in the one or more inductive elements prior to flowing current through the fire path to pulse the diode.

Abstract: Methods, apparatuses, and systems can be provided to implement active feedback to electrically sense or monitor the illumination and shutter pulses and adjust them actively to maintain the desired phase relationship/difference between the pulses. By maintaining the desired phase difference, the distance calculation can be made more accurate, even when conditions of the time-of-flight camera varies (e.g., temperature, aging, etc.). Advantageously, active compensation can correct for errors ‘on-the-fly’, eliminating detailed characterization and manual adjustment during operation.

Abstract: An optical emitter package is disclosed. The optical emitter package can include a carrier, a switching die, and an optical emitter die mounted to the carrier. The optical emitter die can be directly electrically and mechanically connected to the carrier with a conductive adhesive. An energy storage device can be mounted to the carrier. The energy storage device can be directly electrically and mechanically connected to the carrier with a second conductive adhesive. The carrier can provide electrical communication between the switching die, the optical emitter die, and the energy storage device.