Line of sight measuring system

• US 4,823,170 A
• Filed: 02/22/1985
• Issued: 04/18/1989
• Est. Priority Date: 02/22/1985
• Status: Expired due to Fees

• Current Assignee: RICHARDS, III.,JAMES D. AND MARTINE RICHARDS
• Original Assignee: Position Orientation Systems Limited
• Inventors: Hansen, Per K.
• Primary Examiner(s): Rosenberger, Richard A.
• Application Number:
  US06/704,526
• Time in Patent Office: 1,516 Days
• Field of Search: 356/375, 250/205 R, 358/107
• US Class Current: 356/620
• CPC Class Codes: G01S 17/875 for determining attitude
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating
• CPC Class Codes: G06F 3/0304 Detection arrangements using opto-electronic means constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042

Abstract

The present invention relates to a line-of-sight measuring system. The system comprises a passive optical pointing device which measures the relative change in line-of-sight of a focusing reflector attached to a target such as the operator of the device, located within a prescribed three dimensional space. The system utilizes a source of light adjacent a position sensing detector which source of light causes light to be reflected off the focusing reflector amd back to the position sensing detector. In this way, the line-of-sight between the object within the prescribed space and a particular location on a two dimensional screen positioned adjacent the prescribed space may be determined with great accuracy. The present invention also includes the electronic circuitry which interfaces the present invention with a computer such as a personal computer including an input keyboard and a display screen. Other applications of the present invention are also disclosed herein.

Claims

1. A cursor control system for measuring movements including linear movements and rotational movements of object means placeable in a predetermined space in front of a display means, said system displaying said movements in the form of a display indicative of the line-of-sight between said object means and a prescribed target, comprising:

(a) light source means;

(b) position sensing detector means adjacent said light source means;

(c) focusing reflector means attached to said object means;

(d) control means for controlling activation of said light source means, for receiving signals from said position sensing detector means and for calculating said line-of-sight; and

(e) said display means connected to said control means for displaying information indicative of changes in said light-of-sight in the form of changes in the position of a display cursor.

2. The invention of claim 1 wherein said light source means comprises a plurality of light emitting diodes.

3. The invention of claim 2, wherein said diodes are connected to said control means in series therewith.

4. The invention of claim 2, wherein said diodes emit infrared light.

5. The invention of claim 1, wherein said light source means comprises a first light source of a first distinct wavelength and a second light source of a second distinct wavelength, said control means alternately activating and deactivating said light sources.

6. The invention of claim 5 wherein said object means comprises first and second separate objects, and said focusing reflector means comprises a first focusing reflector attached to said first object and a second focusing reflector attached to said second object.

7. The invention of claim 6, wherein said first focusing reflector has attached thereto a first optical filter allowing solely light at said first wavelength to pass therethrough, and said second focusing reflector has attached thereto a second optical filter allowing solely light at said second wavelength to pass therethrough.

8. The invention of claim 1, wherein said focusing reflector means comprises a parabolic-shaped reflector.

9. The invention of claim 1, wherein said control means comprises a microprocessor.

10. The invention of claim 9, further including an analog-to-digital converter connected between said position sensing detector means and said microprocessor.

11. The invention of claim 10, further including preamplifier means connected between said position sensing detector means and said analog-to-digital converter, said preamplifier means receiving currents from said position sensing detector means and converting the currents to voltages which are inputted into said analog-to-digital converter.

12. The invention of claim 9, wherein said microprocessor includes output port means connectable to a port in an associated host computer, said port being utilized to control said display cursor on said display means, said display means comprising a screen of said computer.

13. The invention of claim 1, further including audible feedback means controlled by said control means, said control means actuating said audible feedback means responsive to sensed time of movement of said line-of-sight.

14. The invention of claim 1, wherein said control means includes means for causing said display means to be split into a plurality of subdisplays.

15. The invention of claim 1, wherein said control means includes means sensing the intensity of light received by said position sensing detector means and, responsive thereto, said sensing means adjusts the intensity of said light source means by adjusting the current supplied thereto.

16. The invention of claim 15 wherein said intensity sensing means includes means sensing when said line-of-sight does not include said display.

17. The invention of claim 16, wherein said control means includes means for initially calibrating said system without cursor involvement or user involvement.

18. The invention of claim 17, wherein said control means includes means for automatically self-re-calibrating said system so that a user thereof can leave the work area and later return thereto without loss of system function.

19. The invention of claim 18, wherein said control means includes means for keeping track of the last instantaneous position of that cursor which translates the relative change in position between an old and new position of the cursor into electrical signals so as to simulate a mouse or other cursor movement input device.

20. The invention of claim 13 or 19, wherein said control means includes means for measuring a time period during which the user is holding the line-of-sight on a specific point of the computer display, said control means responding to said time period and in response thereto generating electrical signals in said computer corresponding to one of one click, two clicks, or hold down.

21. The invention of claim 20, wherein said focusing reflector means may be placed on any part of the user'"'"'s body, for operation when this pat of the body is moved.

22. The invention of claim 21, wherein said control means includes means compensating for ambient light by reading system voltages with and without said light sources being activated.

23. The invention of claim 22, further including preamplifier means interposed between said position sensing detector means and said control means, said control means compensating for preamplifier noise.

24. The invention of claim 1, wherein said position sensing detector means includes a lens for focusing light on an active area of said position sensing detector means.

25. A method for controlling a cursor for measuring linear and rotational movements of object means placeable in a predetermined space in front of a display means, the display of said display means being indicative of the line of sight between said object means and a prescribed target, including the steps of:

(a) locating a position sensing detector adjacent;

said space above said display means;

(b) locating a source of light adjacent said position sensing detector;

(c) attaching a focusing reflector to said object means;

(d) locating said object means in said space;

(e) activating said source of light, light from said source of light being focused by said focusing reflector and being reflected back toward said position sensing detector;

(f) receiving said light at said position sensing detector at a location thereon corresponding to said line-of-sight;

(g) calculating, with a control means, said line-of-sight from data received from said position sensing detector related to said location, said calculating step including the substep of measuring said linear and rotational movements; and

(h) displaying said line-of-sight in the form of movements of a display cursor of said display means.

26. The method of claim 25, further including the step of calibrating said control means.

27. The method of claim 25, further including the step of measuring a time period during which a particular line-of-sight is maintained and, responsive thereto, generating an electrical signal at said control means corresponding to one of one click, two clicks of hold down.

28. The method of claim 25, further including the step of compensating for ambient light by reading system voltages with and without said source of light being activated.

29. The method of claim 25, further including the step of compensating for electrical noise.