Conversational video phone

A conversational freeze-frame video phone for transmitting a voice signal and a single frame of a video gray scale source image over an ordinary telephone line, and receiving a remote voice signal and a remote video image from said telephone line, comprising:

• camera means for capturing said video source image;
• digitizing means for representing said captured video source image as a group of digital values;
• display memory means for storing said group of digital values;
• digital to analog converter means for converting digital values to analog values corresponding to from 2000 to 5,000 pixels representing one of said video source image and said remote video image;
• a modulator/demodulator operative to modulate a carrier signal with said digital values and demodulate such a modulated carrier signal such that transmission of said single frame of said video source image occurs in less than three seconds;
• a transmitter and receiver circuit coupled to said telephone line;
• a matrix of switches coupling said modulator/demodulator to said transmitter and receiver circuit;
• a microphone;
• a speaker;
• analog circuit means coupling said microphone and speaker to said matrix of switches for amplifying said voice signal;
• input keyboard means for inputting alphanumeric data;
• microprocessor means coupled to said input keyboard means for controlling the operation of said video phone;
• and
• display means for displaying images and data having a video source image display of approximately one square inch for displaying said pixels representing a real time mirror image of said video source image, a remote video image display of approximately one square inch for displaying from 2000 to 5,000 pixels representing said remote video image and an alphanumeric display area for displaying alphanumeric data from said microprocessor.

A method for transmitting a single frame of video gray scale source and remote images and audio signals over an ordinary telephone line using a video phone, comprising the steps of:

• capturing said video source image;
• storing a frame of said video source image in a memory;
• mapping the video source image onto a video source image field of from 2000 to 5,000 pixels;
• displaying said video source image field on a first display screen area having an area of approximately one square inch as a real time mirror image of said video source image;
• asynchronously transmitting over said telephone line a modulated signal representing said video source image field in a burst having an approximate duration of three seconds or less;
• asynchronously receiving from said telephone line a modulated signal representing a remote video image field;
• demodulating said receiving signal;
• displaying said remote video image field line-by-line as each line is received on a second display screen area immediately adjacent said first display screen area and having an area of approximately one square inch;
• transmitting a source audio signal over said telephone line;
• and
• receiving a remote audio signal from said telephone line.