U.S. Philips Corporation

Hartmut S Harlos

Klaus G Juhnke

Peter Kelting

Jorg Wolber

Klaus G Kroner

Matthias Peters

Frank Volmari

Karl H Matthies

A method and arrangement for steepening the edges of a color signal, in which a control signal is generated which is obtained by differentiation, rectification and subsequent differentiation of the rectified first differentiation, and is temporarily assigned to the color signal, and in which, in dependence upon the control signal, chrominance values of reference pixels of the color signal are copied on edge pixels of the color signal in such a way that the chrominance values of reference pixels preceding the edge pixels are copied on the edge pixels in the case of a positive control signal and the chrominance values of reference pixels following the edge pixels are copied on the edge pixels in the case of a negative control signal, false chrominance values of pulses which are steepened are prevented in that a chrominance value of a reference pixel is copied on an edge pixel only when the values of the control signal in the assigned region between the reference pixel and the edge pixel do not have a zero crossing.

Method and arrangement for steepening color edges

A circuit arrangement for processing an input video signal (V) is described, which video signal has a fixed black level (SP), a given white peak value (WW) as well as a black peak value (SW) dependent on the picture contents (during tb), in which a correct display of the blackest and brightest parts of the picture contents of the video signal (V) is rendered possible without many components and without interference. To this end the circuit arrangement includes

Contrast and brightness control whereby both are based on the detected

A circuit arrangement for reducing noise when peaking the edges of a useful signal (S1) by combination with a peaking signal (S3) derived therefrom, which signal only influences the useful signal (S1) when a predetermined amplitude threshold is exceeded, which arrangement has a peaking signal stage (20) for supplying the peaking signal (S3) and a noise suppression stage (7) in which a noise suppression signal is generated and is superimposed on the peaking signal (S3), while the peaking signal stage (20) applies the peaking signal (S3) to two push-pull current outputs (21, 22) provides the possibility of a very simple circuit structure, particularly with a view to a space-saving integration on a semiconductor crystal in that each of the push-pull current outputs (21, 22) in the noise suppression stage (7) is connected to a series resistor (23, 24) and to the control terminal of one of two transistors (25, 26) whose main current paths at one end are connected together and to a supply current source (27) and at their other end are connected to the terminal of the associated series resistor (23, 24) remote from the push-pull current output (21, 22, respectively).

Circuit arrangement for reducing noise

Control circuit for calibrating a delay line for a television receiver. The delay line contains series-connected all-pass sections of at least 2nd-order, the inductances of which are replaced by gyrators to which capacitances are connected. During at least one line of the vertical blanking period, the delay line is included into a phase-lock loop for comparison with a line-frequency signal in order to control the delay time of the all-pass sections.

Control circuit for calibrating a delay line

A circuit arrangement for the control of at least one beam current in a picture tube (9) contains a cut-off point control which on the occurrence of a given reference level in the picture signal adjusts the beam current in one sampling interval to a preset value. A trigger circuit (19) and a logic network (22) are provided to prevent picture interference during start-up of the picture tube (9) due to the beam currents which slowly rise as the hot cathodes (8; 801, 802, 803) heat up and due to the cut-off point control which responds only after the build-up of these beam currents. The trigger circuiit (19) suppresses auxiliary pulses used to generate the beam current after the picture tube (9) is turned on and issues a switching signal to close the control loop during the sampling intervals and to release the control of the beam current by the picture signal when the beam current has built up, and the logic network (22) does not release the control of the beam currents by the picture signal until, after the switching signal, a change signal is issued from a change detector (25) indicating that the cut-off point control has responded.

Circuit arrangement for the control of a picture tube

A circuit arrangement includes a differential amplifier, which supplies a balanced alternating voltage having a d.c. component which is filtered by means of a low-pass filter and is used for negative feedback. In order to avoid the use of a second filter capacitor, the voltages are supplied through a low-pass circuit to a second differential amplifier, which supplies an unbalanced d.c. control signal, which is supplied through a further low-pass filter having only one capacitor to the first differential amplifier.

Differential amplifier circuit having improved control signal filtering

In a television receiver circuit arrangement for several standards, the identification circuits are switched on one after the other by a test cycle actuating signal which is maintained when the standard has been identified.

Television receiver circuit arrangement for identifying the standard

A circuit for generating an output pulse with a delayed edge includes a differential amplifier supplied with current by a current source transistor amplifier whose base drive current is delayed by connecting a small capacitor between its base and collector electrodes.

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Norderstedt, Germany

Hartmut S Harlos