A remote-controlled retriever for collecting a ball on a sports playing surface and for controllably releasing the ball includes a front end ball collector having two spaced-apart blades defining a ball collection space. Each blade includes a passive or an active detent for retaining the collected ball in the collection space until a programmed or manually-directed release toward a target location such as a tennis baseline. The retriever includes a processor-controller for controlling and directing the retriever during a retrieval session.

A variable-color region (106) extends to an exposed surface (102) at a zone (112) and normally appears along it as a principal color. The region responds to an object (104) impacting the zone sufficiently hard at an object-contact area (116) by providing an impact signal identifying a criteria-meeting area (1626) where threshold impact criteria are met. Responsive to the impact signal and possibly to supplemental impact criteria being met, a controller (1622) produces a representation of a print area (118) from a representation of the criteria-meeting area by smoothening its perimeter and provides an initiation signal designating a location in the zone for the print area such that it closely matches the object-contact area. An impact-dependent portion (138) of the region responds to the initiation signal and possibly to a tracking condition being met by temporarily appearing along the print area as changed color materially different from the principal color.

A method and system are disclosed for generating a dynamic and responsive color media. The method includes encapsulating nanomaterials within a capsule to form encapsulated photonic crystals; and dispersing the encapsulated photonic crystals within a film or substrate, wherein the encapsulated nanomaterials retain a liquid dispersion state and can move freely within the capsule and the capsules containing photonic crystals remain stationary within the film or substrate.

A let detection system includes a sensor including an accelerometer attached to a tennis net. The sensor is in wireless communication with an umpire device able to send a message to the sensor, wherein the message causes the sensor to calibrate and begin monitoring for a let. The sensor determines a three-dimensional (3D) vector representing the gravity acting on the sensor as a baseline. When the sensor detects vertical acceleration of the net relative to the baseline and the vertical motion is above a preset threshold, the sensor automatically transmits a let notification message to the umpire device.

A variable-color region (886) extending to an exposed surface (102) at a surface zone (892) having a boundary (1212 or 1214) responds to an object (104) impacting the zone sufficiently hard to meet threshold impact criteria at an object-contact area (896) by changing color at a corresponding print area (898) or by providing an impact signal that causes color change at the print area if supplemental impact criteria are also met. In either case, a smoothened image of the print area is produced by determining a portion of the boundary where the print area is nearest the boundary, approximating at least that boundary portion as a smooth boundary vicinity curve, approximating the print area's perimeter, or a portion thereof nearest the boundary, as a smooth perimeter vicinity curve, and comparing the vicinity curves to determine if they meet or overlap.

We generally describe an audio-based line fault detection system for a sports game. The audio-based line fault detection system comprises one or more audio sensors (102) for sensing an audio signal generated by a sports gaming device bouncing off a sports field. The sports field comprises surface modifications applied to a line and/or an area adjacent to the line on the sports field such that the generated audio signal is dependent on whether or not the sports gaming device bounces off the sports field where the surface modifications are applied. The detection system is configured to generate a sound profile from the audio signal sensed by the one or more audio sensors (102). The detection system is further configured to identify a bounce type based on the sound profile, wherein the bounce type is defined by whether or not the sports gaming device has bounced off the sports field where the surface modifications are applied.

A method and system for determining whether a spherical element impacts with a component of a playing field, or arranged on or proximate thereto. The method includes acquiring images of a surveillance area of a field that covers at least part of said component, such as a delimiting perimeter line of a game area or a target, performing an approximate detection of an impact of a spherical element relative to that component or proximate thereto, with an object detection and recognition system that can discern when the detected object is indeed a spherical element, automatically selecting one of the images acquired for the same point in time and that includes the area where said impact has occurred, and analyzing the selected image to check if the spherical element has impacted or not with the component.

A let detection system includes a sensor including an accelerometer attached to a tennis net. The sensor is in wireless communication with an umpire device able to send a message to the sensor, wherein the message causes the sensor to calibrate and begin monitoring for a let. The sensor determines a three-dimensional (3D) vector representing the gravity acting on the sensor as a baseline. When the sensor detects vertical acceleration of the net relative to the baseline and the vertical motion is above a preset threshold, the sensor automatically transmits a let notification message to the umpire device.

A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112) and normally appears along it as a principal color. An impact-dependent portion (138) of the variable-color region responds to an object (104) impacting the zone at an object-contact area (116) by temporarily emitting light suitable for forming color different from the principal color if the impact meets threshold impact criteria such that the impact-dependent portion temporarily appears along a print area (118) of the zone as changed color materially different from the principal color. The print area closely matches the object-contact area in size, shape, and location. Use of light emission to produce the temporary color change is advantageous because the changed color can be virtually any possible visible color.

A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112), normally appears along it as a principal color, and includes impact-sensitive and color-change components (182 and (184). A segment (192) of the impact-sensitive component responds to an object (104) impacting the zone at an object-contact area (116) by providing an impact effect if the impact meets threshold impact criteria. A segment (194) of the color-change component responds to the effect by causing an impact-dependent portion (138) of the variable-color region to temporarily appear along a print area (118) of the zone as changed color materially different from the principal color. The print area closely matches the object-contact area. The object subsequently leaves the object-contact area. The impact-dependent portion first appears as the changed color no more than 0.2 s after the object leaves the object-contact area.