Voice-operated switching circuit for a video communications system

• US 3,944,736 A
• Filed: 06/05/1974
• Issued: 03/16/1976
• Est. Priority Date: 06/05/1974
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Shepard, Wayland L.
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Popek, Joseph
• Application Number:
  US05/476,431
• Time in Patent Office: 650 Days
• Field of Search: 179/1 VC, 179/1 CN, 179/16 B, 179/1 HF, 179/1 SW, 179/1 VL, 179/2 TV, 179/18 BC, 179/1 H, 179/100.1 VC, 178/5.8 R, 178/5.6, 200/61.01, 340/148
• US Class Current: 348/722
• CPC Class Codes: H03K 17/94 characterised by the way in which the control signals are generated
• CPC Class Codes: H04N 7/15 Conference systems

Abstract

In a video communications system for remotely located conference rooms, a voice-operated switching (VOX) circuit comprising:

1. an audio level discriminator (ALD) circuit for eliminating input audio signals below a predetermined magnitude and for locking out access to the VOX circuit when another VOX circuit is activated;

2. an audio duration control (ADC) circuit for controlling the activation of the VOX circuit and the possible loss of access to and preemption by another conferee during pauses between audio signals from any conferee presently having activated the VOX circuit and associated video system;

3. an attack time control (ATC) circuit for preventing short duration audio signals above the threshold level of the ALD circuit from activating the VOX circuit; and

4. an activation circuit for coordinating the output signals of the ALD, ADC, and ATC circuits and operating a video switcher in response to the aforesaid output signals.

Claims

1. In a video communications system for remotely located conferees, a plurality of VOX circuits for controlling respective television cameras responsive to audio signals from respective speaking locations, each said VOX circuit including:

a. input audio level discriminator means for generating an output signal coincident with an input audio signal of equal or greater level than a selected threshold level;

b. attack time control means responsive to the output of the audio level discriminator means for generating a set signal when the duration of the output of the audio level discriminator means exceeds a predetermined amount;

c. audio duration control means responsive to the termination of the output of the audio level discriminator means for generating a clear signal delayed a selected time after said termination; and

d. activation circuit means responsive to the set signal and the clear signal for activating a respective camera control means throughout the interval between the set signal and the clear signal.

2. The video communications system of claim 1 wherein each said VOX circuit includes a self-disabling means responsive to a lock-out signal from any of the other VOX circuits, and further includes means for generating a lock-out signal for disabling the other VOX circuits during said interval.

3. The video communication system of claim 1 wherein each said VOX circuit includes in the audio level discriminator means thereof a self-disabling means responsive to a lock-out signal from any of the other VOX circuits, and wherein each said VOX circuit includes in the activation circuit means thereof lock-out signal generating means for generating a lock-out signal adapted to disable the other VOX circuits during said interval.