Compatible high-resolution video recording format

Abstract

A new VCR recording format, the augmented or 'A-' format, such as A-VHS, is described which is fully compatible with the existing standard recording formats, such as VHS. In the new format, the high-frequencies of the luminance component of the television video signal, which are needed for maintaining sharp pictures but which are missing in standard (VHS) recording systems, are recorded on the video tape in an additional luminance channel, or so-called augmentation channel, which utilizes a portion of the recording spectrum which is above the bandwidth occupied by the luminance component in the standard (VHS) system. A new AM-modulated augmentation signal carrier is used to locate and carry the additional luminance spectrum above the standard VHS luminance FM-spectrum. In the preferred embodiment, the luminance high-frequencies are compressed in bandwidth in order to make efficient use of the bandwidth available in the augmentation channel. The bandwidth compression can be provided by the use of one or more known techniques, such as quadrature modulation of the carrier or multi-dimensional pre-processing of the luminance high-frequencies. The bandwidth for this augmentation channel can be obtained by making A-VHS recordings on higher quality tape material, such as that used for the S-VHS format, and by utilizing better recording/playback heads with smaller gaps and higher coercivity, such as also used in the S-VHS system.