Abstract: A presence sensing system provides one or more visible indicators useful for indicating a relative location of objects sensed within the scanning field of view. For example, the system may have an indicator array or an integrated display assembly in which individual indicators or indicator positions correspond to defined portions of the system's field of view. In this manner, the presence sensing system can indicate where one or more sensed objects lie within its field of view. The system may monitor or otherwise scan an angular field of view and may have an indicator array comprising a plurality of individual indicators, each one corresponding to a portion of the monitored area. With this configuration, the system selectively illuminates or otherwise activates those indicators in the array corresponding to the relative angles of detected objects within its field of view.

Abstract: A circuit generates a test signal useful in verifying the actual delay values of individual delay stages in a digital delay line. In general, the cumulative delay of the delay line defines a window in time having its zero point anchored to the beginning of the delay line. Successive delay stages correspond to successive time bins within the overall time window. The test signal shifts at a known, linear rate in time with respect to a reference signal, which is used to initiate a test cycle. The reference signal synchronizes sampling of the test signal to the beginning of the time window. Samples of the test signal are taken at sample points determined by the actual time delays in the successive delay stages. The observed distribution of test signal edges across the time window may be used to determine the actual delay intervals of the delay line.

Abstract: A clockless time-of-flight interval timer includes a tapped delay line register comprising N buffers that each contribute a substantially identical incremental time delay. A latched version of a START pulse associated with an output of transmitted energy from a laser is propagated through the tapped delay line. A DATA signal representing a detected pulse returned from a target is coupled to a block of four comparators each having a different signal threshold. The output of each comparator block is provided as input to one of four channel registers, each register comprising N D-type flipflops separately but synchronously triggerable by tapped incrementally delayed outputs from the N buffers. Channel register outputs are multiplexed and decoded and interfaced with a microprocessor. The microprocessor determines first signal time over threshold (FOT) information and total time over threshold (TOT) information from the channel registers.

Abstract: A circuit generates a test signal useful in verifying the actual delay values of individual delay stages in a digital delay line. In general, the cumulative delay of the delay line defines a window in time having its zero point anchored to the beginning of the delay line. Successive delay stages correspond to successive time bins within the overall time window. The test signal shifts at a known, linear rate in time with respect to a reference signal, which is used to initiate a test cycle. The reference signal synchronizes sampling of the test signal to the beginning of the time window. Samples of the test signal are taken at sample points determined by the actual time delays in the successive delay stages. The observed distribution of test signal edges across the time window may be used to determine the actual delay intervals of the delay line.

Abstract: A presence sensing system provides one or more visible indicators useful for indicating a relative location of objects sensed within the scanning field of view. For example, the system may have an indicator array or an integrated display assembly in which individual indicators or indicator positions correspond to defined portions of the system's field of view. In this manner, the presence sensing system can indicate where one or more sensed objects lie within its field of view. The system may monitor or otherwise scan an angular field of view and may have an indicator array comprising a plurality of individual indicators, each one corresponding to a portion of the monitored area. With this configuration, the system selectively illuminates or otherwise activates those indicators in the array corresponding to the relative angles of detected objects within its field of view.