Interactive graphics transmission system employing an adaptive stylus for reduced bandwidth
First Claim
1. Apparatus for communicating modifications to an image of a previously transmitted graphic, comprisingmeans responsive to locations of a tip of a stylus with respect to the graphic for specifying addresses of image portions which are to be changed,means for defining instructions for changing the image of the graphic,means responsive to said specified addresses and said defined instructions for forming a modification communication, andwherein said defining means includes means responsive to tilt of the stylus for controlling the production of at least a portion of the defined instructions.
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Accused Products
Abstract
An interactive graphics transmission system for use, illustratively, in video teleconferencing is described which advantageously reduces the amount of transmission bandwidth and user effort required to transmit changing graphical information. This is accomplished by first transmitting a full image of the graphic followed only by the changes which a conferee makes to that graphic. Those changes are determined by sensing the tilt of a light pen and the location of its tip, which is closest to the graphic, as a conferee manipulates the pen to change the graphic. The tilt of the pen primarily determines the mode in which the light pen is used. The mode information, in conjunction with the location of the pen'"'"'s tip, is used to generate an instruction which specifies the way in which the graphic is to be changed, e.g., whether information is to be added to, deleted from or emphasized in a graphic. In addition, the location of the pen'"'"'s tip specifies the address of that portion of the graphic that is to be changed. By transmitting just the instruction and address information while the user simultaneously manipulates the light pen to change a graphic, transmission bandwidth and user effort are both advantageously minimized.
154 Citations
31 Claims
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1. Apparatus for communicating modifications to an image of a previously transmitted graphic, comprising
means responsive to locations of a tip of a stylus with respect to the graphic for specifying addresses of image portions which are to be changed, means for defining instructions for changing the image of the graphic, means responsive to said specified addresses and said defined instructions for forming a modification communication, and wherein said defining means includes means responsive to tilt of the stylus for controlling the production of at least a portion of the defined instructions.
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12. In a system for changing a displayed image of a previously transmitted graphic comprising
means responsive to locations of a tip of a stylus with respect to the graphic for specifying addresses of image portions which are to be changed, means for defining instructions for changing the image of the graphic, means responsive to said specified addresses and said defined instructions for forming a modification communication, means for changing the displayed image in accordance with said modification communication, and wherein said defining means includes means responsive to tilt of said stylus for controlling the production of at least a portion of the defined instructions.
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25. In a stylus, capable of being used in a variety of modes to provide input information to an electrical system, an input signal generating system comprising
means for sensing whether an end of the stylus it tilted downward with respect to the other, means for determining whether an end of said stylus is depressed against a surface, and means responsive to said sensing and determining means for generating a plurality of signals indicative of which mode the stylus is being used.
Specification