Abstract: A user interface is configured to detect an attempt to touch a virtual button. The interface includes a first concave mirror facing a second concave mirror. The second concave mirror includes an aperture. A physical control button is arranged proximate to the first mirror and aligned such that an image of the control button in a form of a virtual button appears at the aperture. An attempt to touch the virtual button is detected, and feedback is generated at the virtual button in response to detecting the attempt to touch the virtual button by a user.

Abstract: An interactive display system includes a pixel-based display surface and a light pen. A sequence of patterns is projected onto the display surface. The sequence of patterns has a unique sequence of light intensities for each location of the display surface. Intensities of light at an arbitrary location are sensed by the light pen while projecting the sequence of patterns. The intensifies of light are decoded to determine coordinates of the arbitrary location.

Abstract: An appliance control panel detects on ON gesture by a user approximately near a set of electrodes in a surface of the appliance, in which the electrodes sense a capacitive coupling to the user. The appliance is turned on in ON in response to the detecting of the ON gesture by the user. A capacitive coupling substantially near a particular one of the set of electrodes by the user is detected to perform a control action.

Abstract: A method calibrates a stylus to a display interface by first resetting a calibration pattern and calibration parameters. The calibration pattern is displayed on the display interface at a location corresponding to an estimated position of a stylus tip. The position of the stylus tip is measured while sensing the calibration pattern with a photosensor arranged on the stylus tip. If coordinates of the location are equal to coordinates of the position, then the resetting, displaying, measuring and determining steps are repeated periodically, and otherwise a size of the calibration pattern is increased and the displaying, measuring and determining steps are repeated.

Abstract: A method determines an amount of time consumers are viewing an advertising display. A sequence of images is acquired by a camera of a scene in front of an advertising display. Faces are detected in the sequence of images. For each detected face, determine an orientation of the face with respect to the advertising display and a preference for a particular advertisement can be determined.

Abstract: An apparatus measures a fluid level in a container. A light source emits a light beam. A light sensor can sense the light beam. An optical conduit is arranged in a container for holding fluid. The optical conduit is arranged between the light source and the light sensor along a path of the light beam, such that at least one part of the light beam passes through the optical conduit, and at least an other part of the light beam passes through the fluid when the container holds the fluid. The sensor senses the light beam when a level of the fluid coincides with the one part of the light beam passing through the optical conduit, and the sensor does not sense the light beam when the level of the fluid coincides with the other part of the light beam passing through the fluid due to internal reflection at the fluid level.

Abstract: A system measures reflectance in a scene. A first optical sensor is configured to measure incident energy at a location in a scene. A second optical sensor is configured to measure reflected energy from the location in the scene. The incident energy and the reflected energy are analyzed to determine a photometric property at the location of the scene.

Abstract: An optical receiver is arranged at a location in a scene. The optical receiver includes a photo sensor configured to detect spatio-temporal modulated optical signals directed at the scene from a set of spatially dispersed optical transmitters, and to convert the optical signals from each of the optical transmitters to a corresponding electronic signal. The electronic signals can be analyzed to determine geometric properties of the location in the scene.

Abstract: A projector that illuminates a scene with multiplexed light patterns includes a passive physical mask, and a set of spatially dispersed optical emitters arranged behind the physical mask. The optical emitters are modulated to project a set of unique optical light patterns.

Abstract: In a rear projection television, cathode ray tubes are mounted inside an enclosure so that each cathode ray tube projects output images onto a rear projection screen using a corresponding electron beam. Calibration images are generated for each cathode ray tube. A camera, also mounted inside the enclosure, acquires an input image of each calibration image. A distortion in each input image is measured, and the output images of the cathode ray tubes are corrected by adjusting the signals controlling the corresponding electron beams according to the distortion.

Abstract: A wireless location and identification system includes a controller and a tag. The controller has a projector configured to generate a unique temporal sequence of light intensities for each pixel in an output image of the projector and a wireless transceiver configured to emit an output signal and receive an input signal. The tag includes a photo-sensor configured to sense the unique temporal sequence of light intensities of a particular pixel, a transducer configured to receive the output signal from the transceiver, and a means for modulating, according to the unique temporal sequence of light intensities, the input signal for the transceiver in response to receiving the output signal and sensing the unique temporal sequence of light intensities of the particular pixel to indicate a location of the tag to the controller.

Abstract: An optical communications transceiver includes an LED coupled in series with a resistor. A microprocessor has one I/O pin connected to the LED. In a first mode or transmit mode, the LED is periodically driving in forward bias to emit light to transmit data. In a second or receive mode, the LED is periodically not driven in reverse bias, e.g., reverse bias or zero bias. Then, the LED is allowed to change charge of the capacitance of the LED's junction using a photo-current. The change in charge is measured using a timer. When the change in charge exceeds a predetermined threshold, input light is sensed. Thus, the LED can be used to receive data in the second mode.

Abstract: A chemochromic sensor includes multiple bi-directional LEDs, each optically aligned with one or more test areas. Each LED is used as both a light emitter when driven in forward bias, and as a light detector when driven in reverse bias. By alternating the bias on the LEDs, multi-way light measurements of the test area can be obtained.

Abstract: A system determines correspondence between locations on a display surface and pixels in an output image of a projector. The display surface can have an arbitrary shape and pose. Locations of known coordinates are identified on the display surface. Each location is optically coupled to a photo sensor by an optical fiber installed in a throughhole in the surface. Known calibration patterns are projected, while sensing directly an intensity of light at each location for each calibration pattern. The intensities are used to determine correspondences between the locations and pixels in an output image of the projector so that projected images can be warped to conform to the display surface.

Abstract: A system records a sequence of frames of a video in circular buffers. Each buffer is configured to store the frames in a sequential order. Disjoint sets of frames are selected from the video. There is one set of frames for each buffer such that a first set selects a first fraction of the frames, each subsequent set of frames is a smaller fraction then a previous set of frames, and a last set of selected frames includes remaining frames. The sets of frames are stored sequentially in the corresponding buffers.

Abstract: A method and apparatus determining an intensity of light flux. First, a photodiode or LED is charged by reverse-biasing to a fixed voltage. The fixed voltage is a sum of a threshold voltage and a predetermined offset voltage. Then, a time to discharge the photodiode to the threshold voltage by a photo current is measured to determine an intensity of light producing the photocurrent.

Abstract: A location sensitive display device, and method therefor utilized in an entertainment environment. The display device includes a receiver, control circuit, and indication units. Infrared (IR) transmitters are positioned within the entertainment environment and emit a code which is detected and decoded by the receiver or IR photodiode. The receiver generates a control signal in response to the transmitted IR signal, and a control circuit processes the control signal to generate output signals which illuminate Light Emitting Diode (LED) indication units in a sequence determined by the output signals to provide a predetermined visual display. The display can be used in an activity related to the entertainment environment and can be controlled by a user or a central control system. Further, the display device can include a Liquid Crystal Display (LCD) screen to provide various types of games including games of skill and trivia games with questions and answers.

Abstract: An optical communications transceiver includes an LED coupled in series with a resistor. A microprocessor has one I/O pin connected to the LED. In a first mode or transmit mode, the LED is periodically driving in forward bias to emit light to transmit data. In a second or receive mode, the LED is periodically not driven in reverse bias, e.g., reverse bias or zero bias. Then, the LED is allowed to change charge of the capacitance of the LED's junction using a photo-current. The change in charge is measured using a timer. When the change in charge exceeds a predetermined threshold, input light is sensed. Thus, the LED can be used to receive data in the second mode.

Abstract: A telephone handset dynamically buffers a real-time audio signal. The handset includes a microphone and a speaker connected to a telephone network interface. A proximity sensor is located near the speaker of the handset. The proximity sensor is connected to a circuit for measuring a coupling between the handset and an ear of a user. A buffer continuously records the real-time audio signal. The recorded signal can than be played back after the handset is first removed from the ear of the user, and second re-applied with the ear of the user using a time-compressed audio signal, until the playback signal is resynchronized with the real-time audio signal.

Abstract: A chemochromic sensor includes multiple bi-directional LEDs, each optically aligned with one or more test areas. Each LED is used as both a light emitter when driven in forward bias, and as a light detector when driven in reverse bias. By alternating the bias on the LEDs, multi-way light measurements of the test area can be obtained.