[54] SYSTEM FOR DETECTING THE PRESENCE OF AN OBSERVER
[76] Inventors: Ronald E. Blackburn, 43552
Southerland Way, Fremont, Calif.
94539; Barry M. Wannkessel, 767
Chopin Dr., Sunnyvale, Calif. 94087
[21] Appl. No.: 382,686
[22] Filed: Feb. 2,1995
[51] Int CI.6 G08B 13/18
[52] U.S. CI 340/555; 250/221; 340/556;
340/557; 348/152; 351/210; 364/516
[58] Field of Search 340/557, 556,
340/555, 541, 511, 426, 576; 250/221 128/745; 351/209, 210, 221; 348/152-155 356/375; 359/155; 367/93-94; 342/27-28: 364/516-517
[56] References Cited
U.S. PATENT DOCUMENTS
3,825,916 7/1974 Steele etal 340/557
3,986,030 10/1976 Teltscher 351/210 X
4,397,531 8/1983 Lees 351/210
4,684,929 8/1987 Edwards et al 340/541
5,194,847 3/1993 Taylor etal 340/557
5,305,390 4/1994 Frey et al 340/556 X
FOREIGN PATENT DOCUMENTS
240336 10/1987 European Pat. Off. 351/210
2324008 11/1974 Germany 340/557
2215040 9/1989 United Kingdom 340/575
Primary Examiner—Thomas Mullen
Attorney, Agent, or Firm—Chris Papageorge
[57] ABSTRACT
A system is disclosed for detecting the presence of a human who may be observing an artifact which is within his or her line of sight or field of view. The system includes a laser with a lens at the output thereof and which is triggered rapidly in order to produce a pulsed beam having divergent rays of visible or invisible infrared light which irradiates an area to be examined for the presence of an observer. The light reflected from individuals and objects in the area is reflected into a pair of vision devices or pair of vision device assemblies the outputs of which are fed into a computer. The computer has software programs which utilize vision device output data relating to the intensity and location of the light pixels in the image thereof to detect the presence and orientation of the eyes of an individual in the area based on the light pixel intensity and location data.
26 Claims, 12 Drawing Sheets
