Itt Industries, Inc.

Deutsche Itt Industries Gmbh

Thomas Fischer

Ljubomir Micic

Soenke Mehrgardt

Peter M Flamm

Burkhard Giebel

Heinrich Pfeifer

Ulrich Langenkamp

Rolf D Burth

Liubomir Micic

Rainer Schweer

A semiconductor read only memory (ROM) serves to store digitized audio signals in a redundancy free form. The output of the memory is coupled to the input of a data expander in the playback circuit. The memory may also store an algorithm which serves to control operation of the data expander before the signals are further processed via a digital-to-analog converter and where the output of the digital/analog converter is then coupled to the input of an analog amplifier and then to a loud speaker arrangement. In this manner, digitized audio signals can be operated on by either error correcting modules or data expansion modules, both of which modules may include microprocessors where the algorithms for control of the microprocessors are also stored within the read only memory. In this manner, all mechanical movements between the storage medium and the pick up devices, which are typical of the prior art, is eliminated as the main storage medium consists of a read only memory or a plurality of such devices.

Apparatus for the digital storage of audio signals employing read only

To raise the integration level of a video recorder, and to provide a uniform circuit concept suitable for all three color-television standard (PAL, NTSC, SECAM) which, in particular, requires only slight modifications for adaptation to the respective standard, signal processing is performed by fast digital circuits whose signals are stored on the recording medium not in digital form, but after digital-to-analog conversion. The composite color signal is converted into digital form by a fast analog-to-digital converter (aw) whose sampling signal (fc) has a fixed frequency (Fc) for all three color-television standards. Digital signal processing in the chroma channel is performed at a fixed subcarrier frequency (zt) for all three color-television standards which is an integral subharmonic of the sampling frequency (Fc).

Video recorder with a magnetic recording medium in the form of a tape

In an integrated matrix of nonvolatile, reprogrammable storage cells, additional memory is provided to replace defective rows of storage cells. The addresses of the defective rows are stored in a region of the matrix. A correction register can be loaded with the addresses of the defective rows from the region of the matrix when power is first applied to the matrix or whenever the applied power deviates from the expected, nominal value.

Integrated matrix of nonvolatile, reprogrammable storage cells

With this correcting method, errors in bytes are corrected successively. To this end, the signal resulting from the parity check is stored into a page memory, along with the character bits of each byte. The parity check signal replaces the parity bit of each byte. Two successively received identical pages are stored together with their parity check bits into first and second segments of the page memory. The two pages are compared for equality of the character bits and parity check bits. The result of the comparison is evaluated as follows. In case of equality and correct parity, the byte stored in the first segment will remain unchanged; in case of inequality of the two bytes and correct parity of one of the two bytes, the byte having correct parity will be stored into or remain stored in the first segment; in case of inequality and incorrect parity of the two bytes, no change will be made in the first segment; in case inequality and correct parity of the two bytes, the byte in the first segment will be replaced by a blank byte. The next received identical page but one is stored into the second segment by overwriting, and the correction is repeated with this byte. By this method, single errors are detected and corrected and double errors are detected and replaced by a blank character. In a preferred embodiment with a third segment of the page memory, storage of the third received identical page, and corresponding comparisons of the bytes in the three segments, the method is extended so that double errors are corrected as well.

Method of correcting errors in bytes of teletext signals

A sensor system is adapted for use in automatically adjusting the deflection system of a television picture tube so as to compensate for pincushion distortion including a rectangular frame disposed along the edge of the screen within the sweep range of the electron beam. The frame comprises a striplike, regular arrangement of alternately transparent and opaque segments. In a first embodiment, a conductive path having an external terminal and shielded from the cathode of the television picture tube at regular intervals by equally large metal areas runs along the edge of the screen. This arrangement is on the inside of the screen. In a second embodiment, an optical-fiber array with at least one light-sensitive detector mounted at at least one corner is used.

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Umkirch, Germany

Thomas Fischer