Abstract: A coding apparatus for a moving object image input signal such as a television signal detects an uncovered background area appearing upon movement of a moving object in the moving object image input signal and encodes an image signal corresponding to the uncovered background area according to intraframe correlation instead of interframe correlation. The coding apparatus includes a noise reduction circuit for decreasing a noise reduction level for the signal corresponding to the uncovered background area.

Abstract: A video coding apparatus having a quantizer that is controlled by a quantization control signal. Stationary picture elements are coded such that quantization is coarse, which reduces the output information for the picture elements in the stationary image region and increases compression of the signal. The apparatus may include a calculation system for calculating a distance of a stationary picture element from the moving image region. The quantization is performed more coarsely as the calculated distance becomes longer. The quantizer may also be controlled such that coarse quantization is performed over a plurality of frames for the picture elements in the stationary region, and at a predetermined interval finer quantization is performed with respect to the same stationary picture elements, for further improving the picture.

Abstract: An inter-frame coding circuit for encoding a television video signal to reduce the quantity of data to be transmitted. The coding circuit includes a motion detection circuit which produces a motion vector representative of motion contained in the television signal and an inter-frame prediction coder which is responsive to the motion vector and to the input television signal to produce a prediction error signal which indicates frame-to-frame variations in the television signal. Also included is a refresh circuit for spatially correlating the input signal on an intra-frame basis. To reduce or eliminate the possibility that an error in the signal is magnified, the motion vector is set to zero for a predetermined period in relation to an area or a portion of the video signal for which a refresh operation has just been completed. A transmission circuit transmits the motion vector signal, the prediction error signal, and a refresh execution signal which are used for reproducing the original video signal.

Abstract: A power servo booster having front and rear shells coupled together to reciprocally provide a power piston therein. A flexible diaphragm has an inner peripheral surface secured to the power piston and an outer peripheral surface secured to the coupling portion between the front and rear shells. The diaphragm divides the shell into negative pressure chamber and an atmospheric pressure chamber. A portion of the diaphragm confronts the rear face of the power piston and extends therefrom toward the front shell and then is folded back to provide a folded portion defined from outer end portion of the power piston. The folded portion is continuous to a contacting portion of the diaphragm which contacts inner wall of the shell. At least one of the contacting portion and the portion contacting the outer end of the power piston provides a thick wall portion as an high rigidity member.