SU652732A1 - Television transmitter - Google Patents

Description

(54) TELEVISION TRANSMISSION DEVICE

In the drawing there is a structural electrical circuit of the device.

The television transmitting device contains a transmitting television tube 1, the first 2 and second 3 amplifiers connected respectively to the first and second outputs of the transmitting television tube 1, the inverter 4, Kotbjabro connected to the output of the first amplifier 2, in series with soy; inertial unit 5 for analyzing the components of the video signal 3, respectively, and the first and second outputs of the block 7 are connected to the first inputs of the first 8 and second 9 adjustable amplifiers, respectively, the second input of the first adjustable amplifier 8 is connected to the output of the inverter 4, and the output of the first regulator th amplifier 8 is connected to the first input of the adder 10, the second input of the second controlled amplifier 9 is connected to the output of the second amplifier 3 and the output of the second adjustable amplifier 9 is connected to the second input of the adder 10.

The device works as follows.

An optical image of the object is projected onto the photocathode of the transmitting television tube 1. In accordance with the light distribution on the photocathode on the collectors of each of the secondary electron multipliers, currents IK are generated, and. The components of these tokbvs 1c and 1 are due to the difference in illumination between the background and the object.

Signal-to-noise ratio at the output of a Television Transmitter with equal gain factors of adjustable amplifiers 8 and 9 K s

lei-psa

Ka in 1 is 4

(one)

U1ShRT

t

Values of noise currents 1 ,, and L

proportional to the square root of the respective collector currents.

From the output of the transmitting television tube 1, a video signal containing components corresponding to the scattered and reflected components of the current beam current, after amplification in each,

652732

from the channels and inverted polarities, one of the components of the video signal, is fed to the inputs of block 5, in which the magnitude of the noise and signal currents for each of the two components of the video signal is determined; This information enters the decision block 6, in which the values of the gain factors K and Ka of adjustable amplifiers 8 and 9 are calculated, which provide the maximum value of the signal-to-noise ratio at the output of the entire device for a given level of illumination by the ratio

KjItM + Kfllca

four

VI (KauH) (K2l "a) ft

(2)

From the decision block 6, commands about the coefficients Kc and Kg come to block 7, which ensures the issuance of the corresponding signals to the control inputs of adjustable amplifiers 8 to 9; At the same time, their signal size (on

UBX and Ufibix.2 Kg UBX.2

From the output of adjustable amplifiers 8 and 9, the signals are fed to an adder 1O, the output of which is p &. The resulting signal-to-noise ratio, defined by relation (2).

The use of the proposed device significantly improves the efficiency of television systems in comparison with the known devices due to a significant increase in the signal-to-noise ratio.

Formula

A television transmitting device comprising a transmitting television tube, first and second amplifiers connected respectively to the first and second outputs of the transmitting television tube, an inverter whose input is connected to the output of the first amplifier, an adder, characterized in that, in order to increase the signal-to-noise ratio, serially connected unit for analyzing the video signal components (ala, decision unit, and unit for generating control signals, first and second adjustable amplifiers, the first and second the inputs of the unit for analyzing the components of the video signal are from & dieny respectively with the output of the inverter and with the output of the second amplifier, and the first and second outputs of the control signal generation unit are connected to the first inputs of the first and second adjustable amplifiers, respectively, the second input of the first adjustable amplifier is connected output of the inverter, and the output of the first regulated usi. itel is connected to the first input of the adder, the second input of the second adjustable

the amplifier is connected to the output of the second amplifier, and the output of the second regupfum amplifier is connected to the second input of the adder.

Sources of information taken into account in the examination

1, USSR Author's Certificate No. 281533, cl. H O4N 9/07, 1969.