SU1601777A1 - Device for correcting aperture distortion of tv signals - Google Patents

Abstract

The invention relates to television and can be used in video paths of television systems. The goal is to compensate for aperture distortion across the field of a television image introduced by the optics-tube system. The device for correction of television signal aperture distortions comprises a two-dimensional aperture corrector 1, multipliers 2 and 3, an adder 4, a delay unit 5, a generator 6 of control functions for the field, a generator 7 of control functions for the row, a control block 8, an aperture sensor 9 and the switch 10. The original video signal is subjected to a two-dimensional aperture correction. The horizontal and vertical components of the correction signal are multiplied by the weighting factor of the zone in which the original video signal was read. The change in the frequency response of the optical system during a diaphragm is corrected by introducing data from sensor 9 into a correction function, taking into account the irregularity of the aperture characteristic of the transmitting television tube introduced at a given aperture value. 1 il.

Description

The invention relates to the field of television and can be used in video paths of television systems.

The aim of the invention is to compensate for aperture distortions in the field of a television image introduced by an optics-tube system.

The drawing shows a block diagram of a device for correcting aperture distortion of television signals.

The device contains a two-dimensional aperture corrector 1, multipliers 2 and 3, adder 4, delay unit 5, frame correction signal generator b, row correction signal generator 7, control unit 8, aperture value sensor, switch.

The device works as follows.

The original video signal is subjected to a two-dimensional aperture correction in a two-dimensional aperture equalizer 1, which can be used with any two-dimensional aperture corrector having separate outputs of the vertical and horizontal components of the correction signal. The multipliers 2 and 3, to the inputs of which the vertical and horizontal components of the correction signal arrive, perform the role of amplifiers with an adjustable gain factor — using the signal supplied to the control input of the multipliers 2 and 3, and a component of the correction signal is formed at its output, multiplied by the weighting factor of the zone in which the original video signal is read. From the outputs of multipliers 2 and 3, the vertical and horizontal components of the correction signals, overloaded by zone weights, are fed to the adder 4, where the program combines them with the original video signal previously delayed in block 5 to ensure the correct phase relationship between the video signals when summing them up. The signal to the control input of the multiplier 2 or 3 comes from the generator output 7 or 6.

To extract information from generators 6 and 7, the control inputs of the generators receive a sequence of addresses formed in control unit 8, and the diaphragm value sensor signal is converted into a digital code controlling the operation of the switch. The control unit is reset to its initial state at the beginning of each field by means of a sequence of frequency pulses of the rows and fields at the input of the control unit. Outputs

the latter, via a bus, addresses are connected to the inputs of the generators 6 and 7 of the control functions.

During a diaphragm during the operation of the transmitting chamber, the MTF of the optical system changes, as a result, the irregularity corrected for a certain position of the diaphragm with a change appears again.

The whole range of diaphragm values of the transmitting camera is divided into n sections, information on the degree of aperture correction necessary to compensate for the unevenness of the MTF of the optics and the aperture characteristic of the transmitting television tube, taking into account the unevenness of the MTF introduced at this aperture value, is recorded in each of the pairs of correction signal generator pairs. . Depending on the position in which the diaphragm of the camera's optical system is located, from the aperture value sensor to the input of the control unit 8 an analog signal is received, which is converted to. control unit 8 into a digital code. The digital position code of the diaphragm is fed to the input of the switch, which connects to the input of multipliers 2 and 3, one of n pairs of corrective function generators. As a result, correction of the unevenness of the definition in the field introduced by the camera’s optical system is carried out, taking into account its changes during

O diaphragm.

Claims (1)

Invention Formula A device for correcting aperture distortion of television signals, containing a two-dimensional aperture equalizer and a delay unit whose inputs are the device input, the output of the delay unit is connected to the first input of the adder, the output of which is the device output, and the second input of the adder is connected to the output of the multiplier that differs By the fact that, in order to compensate for aperture distortions across the TejieBn3HOHHoro field of the image introduced by the optics-tube system, a control unit and corrective signal generators were introduced for the line and frame , the sensor value of the diaphragm, the output of which is connected to the fourth input of the control unit, the switch () -th input of which is connected to the output of the control unit, and the number of pairs of corrective signal generators is 0 n, where, 2,3 ..., the outputs of the generators of the correction signals are connected to the first inputs of the first and second multipliers through the switch. 0