Still/moving picture selection control circuit for video phone system

• US 5,063,440 A
• Filed: 07/30/1990
• Issued: 11/05/1991
• Est. Priority Date: 07/31/1989
• Status: Expired due to Term

• Current Assignee: Goldstar Jewellery LLC
• Original Assignee: Goldstar Jewellery LLC
• Inventors: Hong, Sam P.
• Primary Examiner(s): Kostak, Victor R.
• Application Number:
  US07/559,165
• Time in Patent Office: 463 Days
• Field of Search: 358/85, 358/83, 358/105, 358/133, 358/134, 379/53, 379/54
• US Class Current: 348/14.14
• CPC Class Codes: H04N 7/141 between two video terminals, e.g. videophone telephonic communication systems combined with television receiver for reception of entertainment or information matter H04M11/085

Abstract

A still/moving picture selection control circuit for selecting a still picture or a moving picture in a video phone system by the operation of a switch. The circuit including a still selection unit for outputting pulse signals, a single-frame signal generating unit for generating single-frame signal, a movie signal generating unit for generating or stopping movie control signals, a still/movie control unit for applying a subcarrier frequency signal to an A/D converter when single-frame signal is output from the single-frame signal generating unit or when movie control signal is output from the movie signal generating unit, a memory section for storing the output signals of the A/D converter to a RAM when the single-frame signal is output and for applying the signals stored in the RAM to a D/A converter when the single-frame signal is not output.

Claims

1. A still/moving picture selection control circuit for a video phone system comprising:

an analog/digital converter for converting input video signals to digital signals synchronized with a subcarrier frequency signal;

a digital/analog converter for converting and outputting the output signals of the analog/digital converter to analog signals synchronized with the subcarrier frequency signal;

a still selection unit for outputting pulse signals in response to the closing of a still switch;

a single-frame signal generating unit for generating single-frame signals synchronized with a vertical synchronizing signal when pulse signals are output from the still selection unit;

a moving picture signal generating unit for continuously outputting moving picture control signals in response to the closing of a moving picture switch and for stopping the output of moving picture control signals by the single-frame signals of the single-frame signal generating unit;

a still/moving picture control unit for applying the subcarrier frequency signal to the analog/digital converter only when the single-frame signals are output from the single-frame signal generating unit or the moving picture control signals are output from the moving picture signal generating unit; and

a memory section for storing the output signals of the analog/digital converter in a RAM when the single-frame signals are output from the single-frame signal generating unit and for applying the signals stored in the RAM to the digital/analog converter when the single-frame signals are not output from the single-frame signal generating unit and the moving picture control signals are not output from the moving picture signal generating unit.

2. A system for enabling the selective display of a single frame or a moving picture, comprising

a source of video signals;

single frame selecting means comprising means for producing an enabling signal that is of a single frame duration of said video signals,

a random access memory;

a source of a subcarrier;

first means responsive to said enabling signal for converting said video signals to first digital signals in synchronism with the frequency of the subcarrier, for a first single frame duration, and storing them in said random access memory;

second means responsive to said enabling signal for reading said random access memory during a second single frame duration following said first single frame duration;

means for converting said converted digital signal in synchronism with the subcarrier frequency during said first frame duration and for converting the output of said random access memory during said second single frame duration, to product output analog signals; and

a moving picture selecting means for controlling said first means responsive to said enabling signal to continuously convert said video signals to first digital signals and for controlling said second means responsive to said enabling signal to continuously selectively convert only the output of said first means to output analog signals.

3. The system of claim 2 wherein said first means comprises an analog to digital converter for converting said video signals at said subcarrier frequency, means responsive to said enable signal for gating said subcarrier to said analog to digital converter, and switch means for applying the output of said analog to digital converter to said random access memory.

4. The system of claim 2 wherein said second means comprises switch means responsive to said enable signal for reading out said random access memory to said digital to analog converter.

5. The system of claim 2 wherein said means for producing said enable signal comprises a switch, and means responsive to operation of said switch for generating said enable signal

6. The system of claim 2 wherein said moving picture selecting means comprises a switch, and means responsive to the operation of said switch for inhibiting reading data from and writing data to said random access memory.