A structured light projector and a method for structured light projection are disclosed. The structured light projector includes a projection module, a processor. The projection module is configured to project an optical pattern onto a region of space, and includes a light source, a diffractive optical element and a liquid crystal lens. The light source is configured to generate a light beam. The diffractive optical element is configured to convert the light beam into the optical pattern. The liquid crystal lens is interposed between the light source and the diffractive optical element, and is configured to collimate the light beam. The processor is configured to generate a control signal depending on an environment temperature of the projection module for controlling the liquid crystal lens.

A depth measurement assembly (DMA) includes a pulsed illuminator assembly, a depth camera assembly, and a controller. The pulsed illuminator assembly has a structured light projector that projects pulses of structured light at a pulse rate into a local area. The depth camera assembly captures images data of an object in the local area illuminated with the pulses of structured light. An exposure interval of the depth camera assembly is pulsed and synchronized to the pulses projected by the pulsed illuminator assembly. The controller controls the pulsed illuminator assembly and the depth camera assembly so that they are synchronized. The controller also determine depth and/or tracking information of the object based on the captured image data. In some embodiments, the pulsed illuminator assembly have a plurality of structured light projectors that projects pulses of structured light at different times.

Thermal variations on an optical scanning device can affect measurements made by that device. Various ways are presented here to control the temperature of a device and compensate for temperature variations of the device.

To perform a high-accuracy three-dimensional measurement by performing an appropriate calibration in accordance with various temperature changes, an information processing apparatus that decides a temperature-dependent parameter of a projection apparatus configured to project a pattern onto a measurement target object to perform a three-dimensional measurement includes a holding unit configured to hold a relationship in which the temperature-dependent parameter of the projection apparatus is set as a temperature function, a temperature input unit configured to input a temperature of the projection apparatus, and a temperature-dependent parameter decision unit configured to decide the temperature-dependent parameter of the projection apparatus based on the temperature of the projection apparatus which is input by the temperature input unit and the relationship.

A system and method of determining three-dimensional coordinates is provided. The method includes, with a projector, projecting onto an object a projection pattern that includes collection of object spots. With a first camera, a first image is captured that includes first-image spots. With a second camera, a second image is captured that includes second-image spots. Each first-image spot is divided into first-image spot rows. Each second-image spot is divided into second-image spot rows. Central values are determined for each first-image and second-image spot row. A correspondence is determined among first-image and second-image spot rows, the corresponding first-image and second-image spot rows being a spot-row image pair. Tach spot-row image pair having a corresponding object spot row on the object. Three-dimensional (3D) coordinates of each object spot row are determined on the central values of the corresponding spot-row image pairs. The 3D coordinates of the object spot rows are stored.

An apparatus for three-dimensional shape measurement is provided, including a projection device, an image capture device, and an image processing device. The projection device sequentially projects a plurality of structured light beams on a scene during a first projection period and a second projection period. The mean level of the structured light beams during the first projection period is the same as the mean level of the structured light beams during the second projection period, and the frequency of the structured light beams during the first projection period is different from the frequency of the structured light beams during the second projection period. The image capture device captures an image of the scene within the projection time of each of the structured light beams. The image processing device obtains a three-dimensional shape of a to-be-measured object in the scene according to the images.

A coordinate measurement machine (CMM) includes a manually-positionable articulated arm. The articulated arm includes arm segments and rotary joints. At least one of the rotary joints includes a bearing assembly that comprises first and second bearings, a shaft that engages an inner race of the first bearing and an inner race of the second bearing, a housing that engages an outer race of the first bearing and an outer race of the second bearing, and a transducer configured to output an angle signal corresponding to an angle of rotation of the shaft relative to the housing. The shaft and the housing may be fabricated from materials having coefficients of thermal expansion selected to minimize change in moment rigidity and/or radial rigidity of the bearing assembly as the ambient temperature changes from the lower limit to the upper limit of the CMM operating ambient temperature range.

An optical dimensioning system includes one or more light emitting assemblies configured to project one or more predetermined patterns on an object; an imaging assembly configured to sense light scattered and/or reflected off the object, and to capture an image of the object while the patterns are projected; and a processing assembly configured to analyze the image of the object to determine one or more dimension parameters of the object. The light emitting assembly may include a single piece optical component configured for producing a first pattern and second pattern. The patterns may be distinguishable based on directional filtering, feature detection, feature shift detection, or the like. A method for optical dimensioning includes illuminating an object with at least two detectable patterns; and calculating dimensions of the object by analyzing pattern separate of the elements comprising the projected patterns. One or more pattern generators may produce the patterns.

A power transfer configuration is disclosed for providing power to a stored coordinate measurement machine (CMM) probe. A storage rack comprising at least one CMM probe receptacle is mounted proximate to a CMM. The CMM may automatically attach and detach from the CMM probe and insert and remove it from the storage rack probe receptacle. The power transfer configuration comprises a primary electromagnetic winding mounted to the storage rack proximate to the probe receptacle, and a secondary electromagnetic winding located internal to and proximate to the CMM probe housing. When the CMM probe is in the probe receptacle, the primary electromagnetic winding receives alternating current and generates a changing electromagnetic field proximate to the CMM probe housing. The secondary electromagnetic winding generates power in the CMM probe in response to receiving the changing electromagnetic field. The CMM probe may be internally heated while stored, using the generated power.

The techniques described herein relate to methods, apparatus, and computer readable media configured to determine parameters for image acquisition. One or more image sensors are each arranged to capture a set of images of a scene, and each image sensor comprises a set of adjustable imaging parameters. A projector is configured to project a moving pattern on the scene, wherein the projector comprises a set of adjustable projector parameters. The set of adjustable projector parameters and the set of adjustable imaging parameters are determined, based on a set of one or more constraints, to reduce noise in 3D data generated based on the set of images.