Abstract: A circuit for implementing an ambient light sensing mode and a proximity sensing mode includes a light sensor, a light source, and a controller coupled to the light sensor and the light source. The controller is configured to process outputs from the light sensor before and after the light source is energized to obtain an ambient light level output and to compare the ambient light level output with an output from the light sensor when the light source is energized to implement the proximity sensing mode.

Abstract: A circuit for implementing an ambient light sensing mode and a proximity sensing mode includes a light sensor, a light source, and a controller coupled to the light sensor and the light source. The controller is configured to process outputs from the light sensor before and after the light source is energized to obtain an ambient light level output and to compare the ambient light level output with an output from the light sensor when the light source is energized to implement the proximity sensing mode.

Abstract: A circuit for implementing an ambient light sensing mode and a proximity sensing mode includes a first light sensor that is more sensitive to light in the infrared spectrum than to light in the visible spectrum and a light source that emits light in the infrared spectrum. The circuit further includes a second light sensor that is sensitive to light in the visible spectrum and a controller coupled to the first light sensor, the light source, and the second light sensor. The controller is configured to process an ambient light level output from the first light sensor without the light source energized with an output from the first light sensor with the light source energized to implement a proximity sensing mode. Further, the controller is configured to process an output from the second light sensor to implement an ambient light sensing mode.

Abstract: An optical touch panel assembly includes a touch panel that has photosensors and light sources, wherein each light source is energizable to produce a field of illumination that illuminates multiple photosensors at a time. The touch panel also includes control circuitry to energize and de-energize the light sources so that at least one but less than all of the light sources are turned on at a time in a sequence to illuminate an entire active area of the touch panel and to analyze output signals from the photosensors. The control circuitry is further configured to identify a low level output signal corresponding to a proximity event and to determine a location of the proximity event on the touch panel.

Abstract: A circuit for implementing an ambient light sensing mode and a proximity sensing mode includes a first light sensor that is more sensitive to light in the infrared spectrum than to light in the visible spectrum and a light source that emits light in the infrared spectrum. The circuit further includes a second light sensor that is sensitive to light in the visible spectrum and a controller coupled to the first light sensor, the light source, and the second light sensor. The controller is configured to process an ambient light level output from the first light sensor without the light source energized with an output from the first light sensor with the light source energized to implement a proximity sensing mode. Further, the controller is configured to process an output from the second light sensor to implement an ambient light sensing mode.