Abstract: A system for focusing a zoom lens objective of a color television camera. A luminance or green video signal derived from a portion of the picture is full-wave rectified and then averaged. The sharpest focus corresponds to the highest value of that average. The signal is converted to digital form and processed by a microcomputer for automatic focusing control by finding the signal maximum with shifting of the lens focus setting. The video signal is stripped of its d.c. component before rectification, but is used with its full bandwidth.

Abstract: A pulse generator for generating pulses having pulse edges at instants at which a varying amplitude input voltage is equal to one of at least two threshold values produced by a voltage source. The pulse generator has at least two voltage comparison circuits each having first and second outputs, first and second inputs for receiving voltages to be compared and third and fourth inputs for receiving blocking voltages applied thereto. The blocking voltages block the transmission of signals to the first and second comparison outputs of each voltage comparison circuit. One of the first or second inputs of each voltage comparison circuit is coupled to the pulse generator, while the other is coupled to the voltage source. The outputs of the voltage comparison circuits are coupled to each other and to the output of the pulse generator by diodes. The diodes connected to the first voltage comparison circuit are biased separately from those connected to the second voltage comparison circuit.

Abstract: A television line deflection circuit for recording or display, comprising a main and an auxiliary deflection signal generator. The main deflection signal generator applies a line-periodic, pulse-shaped voltage to a series arrangement of a deflection coil and a transformer winding. Of a further transformer winding a first terminal is connected to an auxiliary deflection signal generator terminal carrying a varying voltage and a second terminal is connected via a diode to a terminal carrying a reference voltage. A capacitor may be provided in parallel with the diode. An auxiliary deflection voltage which varies in a desired manner results in the desired scan, it being possible to employ for linearity correction a voltage which varies step-wise at intervals during line scanning periods and is, for example, generated by a microprocessor.

Abstract: A system for setting up a video camera. A signal processing circuit provides a plurality of signal channels which may be selectively connected to receive the camera output signal. A microcomputer is provided which stores digital correction values corresponding to minimum error values of distinct sub areas of the video signal. An error measuring circuit determines error values between the average value of a video signal taken over distinct sub areas of a television picture and a reference value. Each of the channels are selectively connected to the digital error measuring circuit to detect an error in the video signal passing through a connected channel.

Abstract: A signal analyzing circuit for a periodically occurring signal such as from a video signal source (VSS). The circuit comprises a store (m) having separate store locations m associated with corresponding regions defined as rows and columns of a picture display of the periodically occurring video signal. In addition, a time signal generator (TG) is provided for the synchronous control of the video signal source (VSS) and the store (m). For filling in a simple manner, without disturbance, the store locations (m) with the mean value of the video signal taken per accurately determined region, the output of the signal source (VSS) is coupled via an analog-to-digital converter (A/D) to counting inputs of a number of counters (BC1 to BC7) equal to the number of regions per row. The counters are operative sequentially and periodically.

Abstract: A filter circuit which operates as a substantially optimum integrating circuit comprises input and output terminals and a differential amplifier, the amplifier having an inverting input connected to the output via a series circuit including a first capacitor and a first resistor. The amplifier output is coupled via a series circuit of a second resistor and a second capacitor to a terminal carrying a reference voltage. The non-inverting input to the amplifier has a DC connection to the reference voltage terminal. One input to the filter circuit connects to the reference voltage terminal, the other filter circuit input being in circuit with the inverting input to the amplifier. The junction between the second resistor and the second capacitor connects to the filter circuit output terminal. The RC time constant of the first capacitor and the first resistor is substantially equal to the RC time constant of the second capacitor and the second resistor.

Abstract: Method for automatically setting up a television camera by means of a microcomputer. The setup is effected in two separate steps, a test pattern being used in each step. An external test pattern is present on a test chart in front of the camera and an internal test pattern is present in the camera in the optical path between a camera lens system and a camera pickup arrangement. During the setup with the internal test pattern, the lens system is optically blocked and correction information is stored in a memory. During or after the setup with the external test pattern, the correction information associated with the internal test pattern is subtracted from the correction information associated with the external test pattern. The resulting correction difference information is lens correction information and is stored in a memory associated with the lens system.

Abstract: A demodulation circuit comprising a high-frequency amplifier (2) and a subsequent demodulator (3) the output of which is fedback to a control input of the amplifier (2) via a keyed automatic gain control circuit (5). In addition, the output is fedback to a carrier input of the demodulator (3) via a phase control circuit (11) and a phase shifter (8) to which a reference carrier (CS) is applied. The phase control circuit (11) is supplied with a pulse-shaped signal (VBS) having periodic pulses. The pulses are directly conveyed to the phase shifter (8) and they further switch a gate circuit (19-23) by means of which the demodulator output is connected to an integrating differential amplifier (26) the output of which is coupled to the phase shifter (8).

Abstract: A deflection circuit has a switching transistor to switch current from a supply transistor through deflection coils. Both the base and collector current of the supply transistor are sensed to eliminate temperature variations in a linearity correction circuit. The deflection coils have series transformers coupled to them for individual linearity correction. This enables higher values of variable resistors to be used, thus eliminating contact potential problems.