SU1216799A1 - Device for scanning reproduction of photographic sound tracks - Google Patents

Abstract

The invention can be used in devices for the qualitative reproduction of sound information by scanning phonograms with a scanning frequency less than twice the maximum frequency of reproducing a given signal, and ncBiiiniaer quality is lost in the frequency range and reducing nonlinear distortions of the signal. For this, the signal from the output of converter 9 through the serially connected direct spectral transposition unit 10, transferring the spectrum of the signal of the second phonogram to the high-frequency region, band-pass filter 11, filter the lean output signal of the direct transposition unit 10, transferring the signal spectrum from the output of the filter 11 to the high frequency half of the spectrum of the original sound signal, and the low pass filter 13 goes to the second output of the device .. 1 il. and fTVw Kof to 05 "K1 X

Description

The invention relates to the optical reproduction of photo phonogram 1x (with two dry information carriers and can be used in devices for the qualitative reproduction of audio information by scanning phonograms with a scanning frequency less than the doubled maximum frequency of the reproduced signal.

The purpose of the invention is improved reproduction quality due to the expansion of the frequency range broadening while reducing nonlinear distortion of the CNG

In the drawing, a structural diagram of the proposed device is selected.

A photo playback device - phonogram Sf consists of a source of 1 mA, the image of which is perpendicularly projected by lens 2 onto the plane of a moving medium 3 photo phonograms, on the optical axis of which, 3 is located behind carrier 3 to a number of digital-to-analog converters 7 n to an additional number of chains 8c,

 from chains 8 with boldly included sequential digital-to-analog converter 9, unit 10 for direct transposition of the spectrum, band-pass filter 1, block 12 for inverse transposition of the spectrum and filter 13 for low frequencies. The control inputs of the switch 6 of the channels and the blocks 10 and 12 of the forward and reverse transposition of the spectra are connected respectively to the first 5 second and third outputs of the sensor 14 time intervals, the input of which is connected to the master oscillator 15,

The device works as follows.

On the moving carrier 3, only one audio channel is recorded in the form of two photo phonograms, one of which carries the worm on the low-frequency half of the spectrum of the audio signal, the other on its high-frequency half,

In the device, these photograms are reproduced by transverse scanning. The result of the playback is recorded by the photodetector 4, the electrical signal from the output of which is 4)

a two-level quantizer cut 5 enters the switch of 6 channels. The latter performs a time separation of digital signals of phonogram of carrier 3 and the supply of signals of phonograms both to a digital-to-analog converter 7, forming at its output an audio signal from the low-frequency sex of the npl spectrum and digital-to-analog converter 9, which forms the main analog signal of the second soundtrack. The signal from the output of the converter 9 through a series of direct transducer unit 10 and a spectrum that performs the nepeji oc of the second photo spectrum 1; lake no.-1Y to the high frequency region of the band-pass filter 11, the filter; the signal of the unit 10 and the transposition of the spectrum, the unit 12 of the reverse transposition of the spectrum, carrying out the transfer of the spectrum of the signal from the output of the filter 11, the region of the high frequency half of the spectrum of the source audio signal, and the filter) 3 n GBy frequency is fed to the second output of the proposed device.

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Claims (1)

Invention Formula A phonophone scanner, containing a light source on the optical axis of which a lens is located, a photo receiver, connected through a two-level quantizer connected in series and a channel switch to a series of digital-to-analog converters that control  the input of the channel switch is connected to the first input of the time interval sensor, the input of which is connected to the master oscillator, so as to  increasing the quality of reproduction due to the expansion of the frequency range during the removal of non-linear distortion of the signal, an additional row of chains has been introduced into it, 50 each row consists of the included sequentially a digital-to-analog converter, a forward trans- spectating unit, a band-pass filter, a flea of the reverse transponder spectrum and a low-pass filter, and the control inputs of the forward and reverse transposition units of the spectra are connected respectively 312167994 to the second and third outputs of the analog-to-analog converters there is a junction of time intervals, and the terminals with the switch are the information inputs of the entered digits. Compiled by V.Sergeev Editor 0.HTeader Tehred o.NeceKorrektor G. Reshetnik Order 1002/59 Circulation 544 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., d, 4/5 Branch PPP Patent, Uzhgorod, Proektna St., 4