초록 ▼

A position determining system for providing electrical signals representative of the positions of a light source movable within a defined area. The system may be implemented for purposes of data entry or for purposes of object location or surveying. When embodied in a data entry tablet, the inventio

A position determining system for providing electrical signals representative of the positions of a light source movable within a defined area. The system may be implemented for purposes of data entry or for purposes of object location or surveying. When embodied in a data entry tablet, the invention provides signals representative of the positions of a stylus movable within the area of the tablet and comprising first and second photodetectors spaced along a base line by a predetermined distance, and means associated with each photodetector and operative to provide a movable narrow field of view for each photodetector. Means are provided for monitoring the angular position of each of the fields of view with respect to the base line and for providing a signal indication of the respective angular positions. A stylus having a light emitter at the tip thereof is movable within the area of the tablet and provides light detachable by each of the photodetectors. Each of the photodetectors provides a respective signal when the field of view of the corresponding photodetector receives light from the emitter. Means are provided which are operative in response to the signal indication of the angular position of each of the movable means at which light from the emitter is respectively detected to provide a signal representing the position of the emitter within the area of the tablet.

대표청구항 ▼

Apparatus for determining the position of at least one light source located and movable within a selected area comprising: light detecting means, for monitoring light means emitted by said at least one light source, at first and second locations, respectively, said first and second locations spaced

Apparatus for determining the position of at least one light source located and movable within a selected area comprising: light detecting means, for monitoring light means emitted by said at least one light source, at first and second locations, respectively, said first and second locations spaced a first predetermined distance apart along a base line; said light detecting means suitable for detecting said light means emitted by said at least one light source located within said selected area, and wherein said light detecting means operates independently of said at least one light source; means for determining a first line of detection between said at least one light source and a first light detecting means, said first line of detection occurring when said light means from said at least one light source is detected by said first light detecting means, and wherein said first line determining means operates independently of movement of said at least one light source; means for determining a second line of detection between said at least one light source and a second light detecting means, said second line of detection occurring when said light means from said at least one light source is detected by said second light detecting means, and wherein said second line determining means operates independently of movement of said at least one light source; means for ascertaining a first angle between said base line and said first line of detection, and for ascertaining a second angle between said base line and said second line of detection; and means responsive to said means for ascertaining for determining and providing signals representative of the position of said at least one light source within said selected area.