Television camera comprising a television pick-up tube and an anti-microphonics circuit
AssigneeU.S. Philips Corporation
InventorsPeter C. Schmale, Hendrik Blom
Life of this patent
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AssigneeU.S. Philips Corporation
InventorsPeter C. Schmale, Hendrik Blom
Estimating the term…
A television camera comprising a television pick-up tube and an anti-microphonics circuit provided with a microphonics detection circuit (17) having a voltage-controlled oscillator included in a phase-locked loop circuit. The detection circuit (17) is not only used for switching on or off (15) the microphonics correction (14) but, as the circuit comprises a phase-locked loop resulting in a proper detection it is also possible to generate a test signal (24) by means of which the microphonics correction signal can be given the optimum phase via an automatic phase adjusting circuit (27). The microphonics correction circuit (14) comprises a low-pass filter (47-52) and a phase shifting network (53-60) for an independent adjustment of the amplitude and the phase.
A television camera having a camera signal channel including a television pick-up tube and an output terminal, and having an anti-microphonics circuit which includes a microphonics detection circuit, a microphonics correction circuit and an on-off switch for microphonics correction depending on whether or not microphonics noise is detected, characterized in that said microphonics detection circuit comprising a signal sample-and-hold circuit, coupled to said camera signal channel at a first connecting point, for processing a video signal which possibly contains a microphonics noise signal, and a phase-locked loop circuit having a voltage controlled oscillator therein coupled to said sample-and-hold circuit, a first output of said phase-locked loop circuit being connected to a switching signal input of said on-off switch, whereby, on the occurrence of a microphonics noise signal, said microphonics detection circuit produces a switching signal on the first output of said phase-locked loop circuit causing said on-off switch to close.
Dependencies are inferred from the claim text.