Abstract: A noise reduction apparatus for reducing noises contained in a television picture signal is realized by comprising a low pass filter for filtering out noise components together with higher frequency components of the picture signal, the latter being compensated thereafter in response to detection of edge portions of the picture, as well as realized by utilizing interframe correlation of the television picture signal for reducing random noise components together with interframe varying components caused by motion of the picture, the latter being compensated thereafter in response to detection of the motion of the picture, which motion is discriminated by interframe variation of a group of picture elements. As a result, the noise reduction of the picture signal can be efficiently attained without any deterioration of picture quality, which is conventionally accompanied therewith.

Abstract: An interframe coding system provided for highly efficient transmission of coded television picture signal is improved by compensating prediction error of predicted picture motion in response to interframe correlation detected by shifting moving blocks in a direction opposite to a motion vector detected for predicting interframe picture motion in order to reduce an amount of coded signals to be transmitted, and further improved regarding the detection of motion vector by examining interframe correlation referred to accumulated logarithms of absolute values of interframe differential picture element signals, and still further improved regarding the compensation of predicted picture motion by changing a coding threshold level in response to picture motion and further by effecting more exact secondary prediction of picture motion. According to these improvements, an extremely high efficiency of transmission of precisely and correctly coded interframe picture signal can be attained.

Abstract: In an analog to digital converting device having plural converting stages provided for converting an analog signal to a multi-bit digital signal, the lowest or just preceding converting stages, wherein analog signals to be converted are quantized by minute steps and can be regarded as similar to Gaussian noises, are arranged to form equivalent digital signals. The analog signals are compared with reference levels based on the average level of the analog signals, for instance, alternating components of analog signals are compared with a zero level, hereby improving accuracy of the conversion by minimizing the effect of DC and gain drift.

Abstract: A serial parallel type A-D converting device having high accuracy and a simplified multi-stage configuration for correcting errors caused by d.c. drift or gain drift in a preceding stage, so as to obviate overloading in a succeeding stage, by means of offering previously a unidirectional level offset to a digital signal converted in the preceding stage, and correspondingly in the succeeding stage, expanding unidirectionally the dynamic range of an A-D converter, and shifting the level of a digital signal converted from an input analog signal deviating out of a normal range by an amount corresponding to the lowest bit of the digital signal converted in the preceding stage, wherein the level offset offered previously is removed later by adding a carry or by subtracting a borrow formed by the A-D converter in the succeeding stage.

Abstract: An analog to digital converter used for converting such an analog signal having dc parts of a constant level periodically as a television picture signal, comprising a plurality of comparators comparing the analog signal with several reference voltage levels, and at least one dc clamper clamping the reference voltage levels in relation to the constant dc level contained in the analog signal. Consequently, the influence affected by dc drifts occuring in the signals and circuit elements may be avoided, so that, high exactness of conversion can be obtained. Besides, in a cascade connection of such converters converting respectively differential analog signals delayed successively to successive bits, high bit rate conversion can be performed without use of high speed circuit elements.

Abstract: A charge-coupled amplifier having a transistor used for transferring an electric charge between capacitors is provided with a charging means for charging the capacitor connected to an emitter of the transistor at a level of a sample-held signal voltage, and a differential signal voltage between the sample-held signal voltage and another sample-held signal voltage applied to a base is derived from a collector of the transistor with a delay of one sampling interval. So that, the charge-coupled amplifier has faculties of a differential amplifier and an analog shift register. Accordingly, a serial-parallel type A-D converting device having a high exactness can be formed simply by using the charge-coupled amplifier.