Abstract: A touch screen including a display, at least two touch units and a control unit is provided. The display has a displaying surface. The touch units are disposed beside the displaying surface. Each of the touch units includes a light source and an image sensor. The light source is adapted to emit a light beam toward a sensible space in front of the displaying surface. The image sensor is adapted to capture the bright spot in the sensible space, and generate an image signal. The control unit is electrically connected to the light sources and the image sensors. The control unit is adapted to receive the image signals from the image sensors, and determine the position of the bright spot relative to the displaying surface according to the image signals. A touch module and a control method are also provided.

Abstract: An image encoder and subcarrier signal generator. The present invention uses a system clock signal to generate a first subcarrier signal and a second subcarrier signal with a phase-delay of 90.degree. behind the first subcarrier signal.

Abstract: A video image signal processing and recording system provides for operation in a first mode in which real time display of video is provided and in a second mode in which the video image signals are digitized and stored in a memory and being read out and displayed in response to selection of a display mode for the system. In an enhanced mode operation for the system, increasing of the low light intensity value of the displayed real time images or displayed memory images to compensate for low light conditions or for the effects of back lighting. The video image signal processing and recording system is described with reference to an application in a door entry system for a residential building.

Abstract: This invention provides a digital television camera processing system and method for feature processing quantized image signals. A single frame memory is required since the frame memory is located prior to the luminance signal processing circuit and the chroma signal processing circuit. The signal processor provides full screen zoom, partial screen zoom, still picture function, mosaic function, and a combination of these functions. Selection of the function is accomplished with inputs to a memory timing control which controls the output sequencing of the frame memory.