SU417920A1 - - Google Patents

Description

The device relates to television technology.

A device for determining the chromaticity coordinates of a color kinescope screen is known, which contains a photoelectric transducer with a rotating light filter, an analog-code converter, a switch with two outputs, indicators, and a block for calculating chromaticity coordinates.

The purpose of the invention is to improve the accuracy of determining the chromaticity coordinates. This is achieved by the fact that in the proposed device, number-pulse converters — a time interval — are connected to the switch outputs, the outputs of which are connected to the inputs of the coincidence circuits, the output signal of which is fed to the indicators. The second inputs of the number of pulses converters are the time interval connected via a frequency divider to the pulse generator, and the second inputs of the coincidence circuits are connected to a pulse shaper consisting of a write pulse counter, a matching circuit and a comparison pulse counter whose input is connected to a pulse generator, and to the input The write pulse counter received a signal from the analog-code converter output.

The drawing shows a block diagram of the described device.

The device contains a photoelectric converter 1, an analog-code converter 2, a pulse shaper 3, a switch 4, converters 5, 6 pulses – time interval, 7, 8 coincidence circuits, indicators 9, 10. The pulse generator 11 is included in the pulse shaper 3 , frequency divider 12, comparison pulse counter 13, comparison circuit 14, write pulse counter 15.

The device works as follows. The light flux from converter 1 is converted to direct current voltage and fed to converter 2. At the output of the latter, a signal is generated in digital form that determines the value of the corresponding x, y or z color coordinates. The number corresponding to the x coordinate is written to converter 5, the number corresponding to the Y coordinate is in converter 6. In the counter 13, as a result of its successive filling with the numbers x, y and z, they are summed up.

The chromaticity coordinates are determined by the following formulas:

XX-y-1 - g

YX + y-2 The device calculates the chromaticity coordinates X and Y. The value of the chromaticity coordinate Z is easy to determine using the formula Z: 1 - X - The principle of dividing one frequency by another consists in converting numbers and g / into a time interval, the sum of x + - in a sequence of pulses and subsequent comparison of the time interval with a sequence of pulses. For this purpose, the analog-code converter 2 is turned off, and from the generator AND the comparison pulses start to flow to the comparison pulse counter, which is connected to the write counter by the comparison circuit 14. As soon as the states of the comparison pulse counter coincide with the recording counter, the output of the comparison circuit 14 is a pulse that arrives at the inputs of the matching circuits 7 and 8 and simultaneously resets the comparison pulse counter so that when the next comparison pulse arrives is in its original state. Then the next cycle is repeated: filling the comparison counter, comparing, resetting, and so on. Thus, at the output of the comparison circuit 14, a sequence of pulses is obtained. At the same time, the signal from oscillator II through the frequency divider arrives at the input of the countdown of converters 5 and 6, the previously written numbers to or y 1 are read. E. These numbers are converted into a time interval. The duration of the pulse of the time interval is directly proportional to the value of the number x or y. The division factor of the frequency divider determines the number of quotients of the division of one number by. another. From converters 5 and 6, the signal goes to the corresponding matching circuit 7 or 8. The second inputs of these matching circuits are pulsed from the generator 3. From the output of the matching circuit, the signal goes to indicators 9 and 10, where the decoding of the signal from the binary code to the decimal occurs. The number of pulses at the output of the coincidence circuit 8 corresponds to the quotient from the division, which determines the value of x + Y + g chromaticity coordinates X, and the number of pulses at the output of the conjunction circuit 7 - to the quotient from Y which determines the values X -} - y + z Have chroma. Object of Invention A device for determining the chromaticity coordinates of a color kinescope screen, comprising a photoelectric converter with a rotating filter, an analog-code converter, a switch with two outputs, indicators, and a chromaticity coordinate calculation unit, characterized in that, to improve the determination accuracy, to the outputs of the switch Converters are connected to the number of pulses - a time interval, the outputs of which are connected to the inputs of the coincidence circuits, the output signal from which is fed to the indicators, the second inputs of the converters are the number of pulses — the time interval is connected via a frequency divider to the pulse generator, and the second inputs of the matching circuits are connected to a pulse shaper consisting of a write pulse counter, a matching pulse counter circuit whose input is connected to a pulse generator, The input of the pulse counter recording signal from the output of the converter analog-code.