Optical reading device for reading an information carrier with motion effect facilities

DETAILED DESCRIPTION The invention can be used for obtaining an automatic stop at the desired frame irrespective of the method of analyzing the frames.
The system for generating a track jump pulse according to the invention makes use of the fact that the frame numbers are recorded at the beginning of each field (in certain systems of recording) to find out whether the reproduced field has or has not come from the same frame as the previously reproduced field.
Accordingly, the system comprises means for comparing the recorded numbers read on two successive fields and for generating a pulse in the case where the two numbers are found to coincide.
When the frame numbers are not recorded, it is sufficient to record a bit which changes value at each new frame.
According to the invention, there is provided an optical reading device for reading signal recorded on an information substrate along a track forming turns, each of said turns comprising two fields of video signal belonging alternately to a same frame and to two adjacent frames, each of said fields comprising an frame identification signal recorded at the top of each field, said identification signal comprising at least one test bit changing value at each successive frame, said optical reading device comprising an optical reader head, driving means for moving said reader head, and a device for generating track jump pulses for controlling said driving means, said device comprising means for detecting said frame identification signals and comparing means for comparing two successive of said identification signals read in two adjacent fields and for delivering at least one of said track jump pulses when said two adjacent fields belong to a same frame.