U.S. Philips Corporation

Theodoor M Kremers

Sing L Tan

Leendert J Van De Polder

Marinus C Van Buul

A compatible television system for high-definition and for standardized low-definition television. In a transmitter (1) in the system, a high-definition video signal (VS1) is generated which is split into a contour signal (HVC2) which on display shows details in the horizontal and vertical directions, and a low-definition video signal (VS6). The low-definition video signal (VS6) is converted into a low-definition video signal (VS7) in conformity with the standard. The contour signal (HVC2) is also converted, but is transmitted periodically over several picture periods (HVC3). Both these converted signals are transmitted or stored, respectively, in two separate signal channels (3,4), each suitable for standard low-definition television. In a receiver (2) the standard video signal (VS7) can be utilized directly for low-definition display by a standard display device (8). In addition, a receiver (2) comprises a high-definition display device (7) in which the converted signals are reconverted and, after having been combined (48) result in a high definition video signal suitable for high-definition display by a picture display apparatus (49 ). As high-definition in the region of movement in the picture may disturb the picture quality, the contour signal may be locally suppressed on display.

Television system for high-definition television and a television

A hybrid D-PCM transmission system includes a transmitter in which an information signal x(n) is converted into a DPCM signal d(n) and an error reduction circuit in which this information signal x(n), or an estimated version thereof, is quantized and encoded to provide an error reduction signal y(n) which is added to the DPCM signal d(n), resulting in a sum signal s(n). In an associated receiver, a locally obtained error reduction signal y'(n) is subtracted from this sum signal s'(n) and the difference signal d'(n) thus produced is converted into a local version x'(n) of the information signal. This last-mentioned information signal is quantized in a local error reduction circuit and encoded to produce the local error reduction signal y'(n). In the transmitter, means are also provided for producing a quantization error signal component q(n) which is added to the sum signal s(n) for transmission. Equivalent means are provided in the receiver for producing a local quantization error signal component q'(n) which is subtracted from the received signal z'(n).

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Eindhoven, Netherlands

Theodoor M Kremers