Abstract: R, G and B outputs from the corresponding preamplifiers of a television camera are supplied to a non-additive mixer (NAM) circuit for continuous selection of the greatest of the three outputs and the selected output is continuously supplied to a set of 9 electronic switches each selecting out a subdivision of the picture field (a, b . . . i). The switched outputs for each of the subfields are then provided to respective subfield measurement detectors which each produce an average value output and a peak value output. These are stored into subfield buffer units and then read out through a multiplexer and an analog to digital converter to a microprocessor. The various values are compared with corresponding past values for selecting between various measurement schemes for obtaining a camera diaphragm control signal, namely spot measurement, center-emphasized integral measurement and selective field measurement.

Abstract: Before the camera is used to transmit a scene, a key or button (21) is actuated which causes a measurement field generator (23) to define a small portion of the picture field, where the video signal level of the greatest of the three color components will be compared with a reference level in an aperture control circuit (6) for setting the camera lens aperture. If this should result in a lens aperture above an upper limit or below a lower limit, an amplification step control (26) for an amplifier (8) is shifted one step so as to bring the lens aperture between the aforesaid limits. The comparison of the video signal level with the reference level is repeated until the amplification is sufficient to bring the lens aperture into the desired range. The measurement field is shown in the camera finder (14) and likewise any off-limits setting of the lens aperture and whether the manual control (28) is on a setting that permits the automatic amplification control to operate.

Abstract: To eliminate or suppress amplifier noise in amplifiers (6, 7) connected to a semiconductor light sensor, for example of a charge coupled type, in which the noise introduced by the amplifiers has a frequency spectrum which is low with respect to the clock frequency of operation of the sensor, the minimum value signal from the light sensor, as amplified, is determined; the maximum value of the signal, as amplified, is determined; and a reference is derived based on the minimum value, for example by clamping the minimum value, or utilizing the minimum value as a dynamic reference for subtraction from the maximum value, to thereby eliminate the effect of low-frequency shift of signals due to low-frequency noise of the amplifiers; various circuits may be used, such as clamping circuits (FIG. 3), threshold or non-additive mixing circuits (FIGS. 4, 5) coupled to a subtraction stage (24), band-pass filtering and envelope demodulation (FIG. 6: 28, 29, 30) or synchronous demodulation (FIG.

Abstract: A method and circuitry for reading out data from a TV pickup (image sensor) designed for the 525-line television standard, and operated in accordance with a line interlace process by once-repeated read-out of each line. In order to adapt the TV pickup (image sensor) to a 625-line television standard, every third line scan is repeated twice, i.e., every third line is read out three times.Both analog and digital circuits are presented.