44 results about "Time of flight imaging" patented technology

An improved solution for generating depth maps using time-of-flight measurements is described, more specifically a time-of-flight imager and a time-of-flight imaging method with an improved accuracy. A depth correction profile is applied to the measured depth maps, which takes into account propagation delays within an array of pixels of a sensor of the time-of-flight imager.

A high-speed, high-sensitivity demodulation sensor usable for e.g. time-of-flight application uses a back side illuminated (BSI) image sensor chip, in which the photo-generated charges are first transferred to a demodulation area, from which the charges are then sampled and stored on at least one specific storage node. The storage node is electrically isolated from the sensitive area. Such a pixel might find its use specifically in 3D time-of-flight imaging given its improvements in sensitivity because the presented invention allows to design pixel with up to 100% fill factor and enables charge detection even if the charge generation by the photon occurs deep in the silicon substrate.

A time-of-flight (TOF) imaging system includes illumination circuitry, such as a laser, one or more sensors, such as SPAD arrays, and image processing circuitry. The illumination circuitry illuminates one or more objects in an environment around the TOF imaging system. The sensors generate an image data stream based on reflections from the one or more illuminated objects, and possibly based on reflections from one or more reflectors. The image processing circuitry generates counts associated with distances based on the image data stream and possibly a reflection data stream and stores the generated counts in a histogram using a plurality of bins. Each of the plurality of bins stores counts associated with a respective distance range. A size of a bin in the plurality of bins is a function of the respective distance range, and may be based on a logarithmic function of the distance associated with the bin.

An autonomous mobile system comprising: a means of achieving mobility, a means of navigating, a means of providing autonomous power, and a means of providing general purpose computing. In some embodiments, the system comprises a base unit capable of sensing its environment and computing navigation instructions to direct the system to move to particular locations and execute functions as directed by a set of programmed instructions. In some embodiments, two or more time-of-flight (TOF) imaging systems are attached to measure distance to objects in the environment, which may in turn be used by the means of navigating. In some embodiments, a coupling exists on the base unit to attach additional structures and mechanisms. These structures may comprise a means for carrying packages or other items, robotic manipulators that can grab and move objects, interactive audio and video displays for telepresence applications, a means for serving food and drink, etc.

The application relates to a calibration circuitry and method for a time of flight imaging system. The time of flight imaging system includes a light source coupled to emit light pulses to an object in response a light source modulation signal generated in response to a reference modulation signal. Each pixel cell of a time of flight pixel cell array is coupled to sense light pulses reflected from the object in response a pixel modulation signal. A programmable pixel delay line circuit is coupled to generate the pixel modulation signal with a variable pixel delay programmed in response to a pixel programming signal. A control circuit is coupled to receive pixel information from the time of flight pixel array representative of the sensed reflected light pulses. The control circuit is coupled to vary the pixel programming signal during a calibration mode to synchronize the light pulses emitted from the light source with the pulses of the pixel modulation signal.

A time of flight sensor includes control circuitry and a time of flight pixel array. The control circuitry is coupled to synchronously send a sync signal. The time of flight pixel array includes a plurality of time of flight pixel cells. Each one of the time of flight pixel cells includes a photosensor and a delay circuit. The photosensor is configured to generate an image signal in response to receiving photons from a light pulse reflected from an object. The delay circuit is coupled to generate a delayed sync signal in response to the sync signal. The delay circuit includes a delay transistor. The time of flight pixel array includes a transistor gradient where a transistor gate length of the delay transistor varies so that each of the time of flight pixel cells receive their respective delayed sync signal at a same time.

A depth of field imaging apparatus includes a light field imager and a time of flight imager combined in a single on-chip architecture. This hybrid device enables simultaneous capture of a light field image and a time of flight image of an object scene. Algorithms are described, which enable the simultaneous acquisition of light field images and a time of flight images. Associated hybrid pixel structures, device arrays (hybrid imaging systems), and device applications are disclosed.

A demodulation pixel architecture allows for demodulating an incoming modulated electromagnetic wave, normally visible or infrared light. It is based on a charge coupled device (CCD) line connected to a drift field structure. The drift field is exposed to the incoming light. It collects the generated charge and forces it to move to the pick-up point. At this pick-up point, the CCD element samples the charge for a given time and then shifts the charge packets further on in the daisy chain. After a certain amount of shifts, the multiple charge packets are stored in so-called integration gates, in a preferred embodiment. The number of integration gates gives the number of simultaneously available taps. When the cycle is repeated several times, the charge is accumulated in the integration gates and thus the signal-to-noise ratio increases. The architecture is flexible in the number of taps. A dump node can be attached to the CCD line for dumping charge with the same speed as the samples are taken. Different implementations are described herein, which allow for smaller design or faster speed. The pixel structure can be exploited for e.g. 3D time-of-flight imaging. Both heterodyne and homodyne measurements are possible. Due to the highly-efficient charge transport enabled by static drift fields in the photo-sensitive region and small-sized gates in the CCD chain, high frequency bandwidth from just a few Hertz (Hz) up to greater GHz is supported. Thus, the pixel allows for highly-accurate optical distance measurements. Another possible application of this pixel architecture is fluorescence lifetime imaging microscopy (FLIM), where short laser pulses for triggering the fluorescence have to be suppressed.

A driver assistance system (12) comprises an optical detector (14) with active scene illumination. The optical detector includes at least one of a stereoscopic imager, a time-of-flight imager, a structured-light imager and a night vision system. The optical detector includes a light source (16) for converting electrical energy into light, projection optics (18) for illuminating a scene with light generated by the light source and one or more optical sensors (20) for detecting light returned from the scene in response to the scene being illuminated. The light source is thermally connected to a heat sink (30) for evacuating heat produced by the light source and the projection optics are optically connected to the light source with one or more optical fibers (22) for transport of light generated by the light source to the projection optics.

A pulse sequence for time-of-flight (TOF) magnetic resonance angiography (MRA) includes a fatsat segment, a magnetization transfer segment, and a spatial saturation segment that are applied by an MR apparatus to acquire MR data for image reconstruction with improved image quality. The pulse sequence is constructed such that at the beginning of each iteration of the inner loop of a 3D acquisition, a fatsat pulse is applied. After the fatsat pulse, MR data is acquired in a series of imaging segments with well-suppressed fat signal. Effective fat suppression is achieved by sampling central k-space data first, before signal from fat relaxes back to a pre-saturation level. Each imaging segment is immediately preceded by one of a MT pulse or a spatial saturation pulse and immediately followed by the other one of the MT pulse or the spatial saturation pulse.

The imaging apparatus includes an image sensor circuit comprising a time of flight sensor pixel. The imaging apparatus further includes a first light emitter having a first spatial offset relative to the time of flight sensor pixel. The imaging apparatus further includes a second light emitter having a second spatial offset relative to the time of flight sensor pixel. The imaging apparatus further includes an image processing circuit configured to produce an image of a region of an object based on first sensor pixel image data and second sensor pixel image data generated by the time of flight sensor pixel. The first sensor pixel image data is based on received light emitted by the first light emitter and reflected at the object's region and wherein the second sensor pixel image data is based on received light emitted by the second light emitter and reflected at the object's region.

Energy-efficient epipolar imaging is applied to the ToF domain to significantly expand the versatility of ToF sensors. The described system exhibits 15+ m range outdoors in bright sunlight; robustness to global transport effects such as specular and diffuse inter-reflections; interference-free 3D imaging in the presence of many ToF sensors, even when they are all operating at the same optical wavelength and modulation frequency; and blur- and distortion-free 3D video in the presence of severe camera shake. The described embodiments are broadly applicable in consumer and robotics domains.

A time-of-flight imager pixel has a light-sensitive region, a first and a second integration gate associated with the light-sensitive region, a first and a second sense node, a first output gate arranged between the first integration gate and the first sense node and a second output gate arranged between the second integration gate and the second sense node, a method for operating such a pixel includes

exposing the light-sensitive region to light so as to optically generate charge carriers;

collecting the charge carriers alternatively under the first and second integration gates;

adjusting voltages of the first and second output gates and the first and second integration gates, thereby transferring a first portion of the charge carriers from the first integration gate into the first sense node and a second portion from the second integration gate into the second sense node;

calculating time-of-flight information based on the first and second portions of charge carriers.

adjusting at least one voltage so as to transfer, if respectively the first and/or second integration gate is close to or in saturation, an amount of charge carriers form the first and/or second integration gate into the first and/or second sense node; and

testing whether a voltage change exceeding a given threshold was thereby provoked in the first and/or second sense node.

Time of Flight (ToF) depth image processing methods are disclosed for resolving corruption of ToF depth images. In ToF depth imaging, the light can travel paths of different lengths before returning to the pixel. Thus, the light hitting the pixel can have travelled different distances, and the distance obtained from an estimation procedure assuming a single distance may be spurious. Systems and methods are disclosed for including a time-of-flight imager and processor which resolves the multiple paths, and outputs the multiple depths at each pixel.

Aspects of the embodiments are directed to time-of-flight (ToF) imaging systems and method for image processing. The ToF imaging system can include a depth sensor; a light steering device; a photodetector; and an image processor. The ToF imaging system can be configured to acquiring a first image of a scene by the photodetector; identifying one or more regions of interest of the scene from the first image; and capturing a depth map of at least one of the one or more regions of interest.

The present disclosure generally pertains to a time-of-flight imaging apparatus having circuitry configured to: demodulate, in a normal operation mode for determining a distance to a scene, at a predetermined number of phase locations a modulated light sensing signal representing modulated light reflected from the scene, thereby generating imaging frames for determining the distance to the scene, and apply, during the normal operation mode, a phase sweep by shifting the predetermined number of phase locations, thereby generating phase sweep frames for determining a cyclic error.