Solid-state optical position determining apparatus

• US 4,820,050 A
• Filed: 04/28/1987
• Issued: 04/11/1989
• Est. Priority Date: 04/28/1987
• Status: Expired due to Fees

• Current Assignee: Wells-Gardner Electronics Corporation
• Original Assignee: Wells-Gardner Electronics Corporation
• Inventors: Griffin, James L.
• Primary Examiner(s): EVANS, FANNIE L
• Application Number:
  US07/043,503
• Time in Patent Office: 714 Days
• Field of Search: 356/375, 250/221, 250/236, 178/18, 340/365 P
• US Class Current: 356/621
• CPC Class Codes: G06F 3/0423 using sweeping light beams, e.g. using rotating or vibrating mirror

Abstract

An optical position determining apparatus for detecting radiant energy reflected from a target zone includes an emission device for generation and emission of radiant energy, a device for redirecting radiant energy across the target zone, a reflecting device for reflecting the radiant energy back from the target zone, and a detector device for sensing the presence of radiant energy reflected from the target zone. The emission device is stationary and emits a beam of radiant energy toward the redirecting device, which redirects the radiant energy along a primary beam path. The redirecting device also is configured for permitting a return beam of light from the target zone to impinge upon the detector device, which is located therebehind with respect to the direction of travel of the return beam. The detector device includes a CCD (charge coupled device) linear sensor formed of a plurality of sensor elements. The sensor elements are pulsed in successive order for scanning the target zone for the presence of the reflected radiant energy and for producing an electrical signal in response to the presence of such reflected radiant energy.

Claims

1. An optical position determining apparatus for detecting radiant energy reflected from a target zone comprising:

emission means for generating and for emitting of radiant energy;

means for redirecting the radiant energy across the target zone;

means for reflecting the radiant energy back from the target zone;

detector means for sensing the presence of radiant energy;

said emission means being stationary and emitting a beam of radiant energy toward said redirecting means to be directed therefrom along a primary beam path in a first direction to the target zone;

said detector means being located along said primary beam path for detecting the radiant energy reflected from the target zone back along the primary beam path in a second direction substantially opposite to said first direction;

said redirecting means being configured for permitting at least a portion of an incident beam traveling in said second direction along said primary beam path to pass therethrough for detection by said detector means;

said detector means including a CCD (charge coupled device) linear image sensor formed of a plurality of sensor elements, said sensor elements being pulsed in successive order for scanning the target zone for the presence of the reflected radiant energy and for producing an electrical signal which is proportional to the intensity of the radiant energy reflected from the target zone in response to the presence of such reflected radiant energy; and

electronic processing circuit means connected to said linear image sensor for processing of said electrical signal, said electronic processing circuit means including interface circuit means for indicating angular displacements from a reference so that when an obstruction is located within the target zone a first notch having a secondary angle and a second notch having a primary angle will appear in said electrical signal.

2. An optical position determining apparatus as claimed in claim 1, wherein said electronic processing circuit means further includes microprocessor means for calculating the vertical and horizontal coordinates of the obstruction based upon said primary and secondary angles.

3. An optical position determining apparatus as claimed in claim 1, wherein said redirecting means comprises a split mirror formed of a first portion and a second portion spaced apart from the first portion and forming a gap therebetween, each of said first and second portions having a substantially flat reflective surface facing away from said linear image sensor, said gap extending through said reflective surfaces and being substantially centered with respect to said linear image sensor and said primary beam path.

4. An optical position determining apparatus as claimed in claim 3, wherein said gap between said first and second mirror portions diverge from one end thereof to the other end thereof.

5. An optical position determining apparatus as claimed in claim 4, wherein said mirror portions have edges adjacent the opening which are chamfered at approximately 50°

so as to reduce the amount of light transmitted from the emission means that can be passed directly through the mirror portions.

6. An optical position determining apparatus as claimed in claim 3, further comprising a transmitter lens interposed between said emission means and said split mirror for focusing the beam of radiant energy produced by said emission means upon an area of said mirror portions substantially surrounding said gap therein.

7. An optical position determining apparatus as claimed in claim 6, further comprising a receiver lens interposed between said split mirror and said linear image sensor for focusing of the reflected radiant energy from said target zone received through said gap upon said linear image sensor.

8. An optical position determining apparatus as claimed in claim 3, wherein said reflective surfaces of said first and second mirror portions are disposed for redirecting the beam of radiant energy from said emission means substantially at a right angle, said emission means being located above said primary beam path.

9. An optical position determining apparatus as claimed in claim 1, wherein said emission means comprises a light-emitting diode.

10. An optical position determining apparatus as claimed in claim 1, wherein said redirecting means comprises a single-piece mirror.

11. An optical position determining apparatus for detecting radiant energy reflected from a target zone comprising:

emission means for generating and for emitting of radiant energy;

means for redirecting the radiant energy across the target zone;

means for reflecting the radiant energy back from the target zone;

detector means for sensing the presence of radiant energy and for producing an electrical signal in response thereto;

said emission means being stationary and emitting a beam of radiant energy toward said redirecting means to be directed therefrom along a primary beam path in a first direction to the target zone;

said detector means being located along said primary beam path for detecting the radiant energy reflected from the target zone back along the primary beam path in a second direction substantially opposite to said first direction;

said redirecting means being configured for permitting at least a portion of an incident beam traveling in said second direction along said primary beam path to pass therethrough for detection by said detector means; and

said redirecting means including a split mirror formed of a first portion and a second portion spaced apart from the first portion and forming a gap therebetween, each of said first and second portions having a substantially flat relative surface facing away from said detector means, said gap extending through said reflective surfaces and being substantially centered with respect to said detector means and said primary beam path.

12. An optical position determining apparatus as claimed in claim 11, wherein said gap between said first and second mirror portions diverge from one end thereof to the other end thereof.

13. An optical position determining apparatus as claimed in claim 12, wherein said mirror portions have edges adjacent the opening which are chamfered at approximately 50°

so as to reduce the amount of light transmitted from the emission means that can be passed directly through the mirror portions.

14. An optical position determining apparatus as claimed in claim 11, wherein said reflective surfaces of said first and second mirror portions are disposed for redirecting the beam of radiant energy from said emission means substantially at a right angle, said emission means being located above said primary beam path.

15. An optical position determining apparatus as claimed in claim 11, further comprising electronic processing circuit means connected to said detector means for processing of said electrical signal, said electronic processing circuit means including interface circuit means for indicating angular displacements from a reference so that when an obstruction is located within the target zone a first notch having a secondary angle and a second notch having a primary angle will appear in said electrical signal.

16. An optical position determining apparatus as claimed in claim 15, wherein said electronic processing circuit means further includes microprocessor means for calculating the vertical and horizontal coordinates of the obstruction based upon said primary and secondary angles.

17. An optical position determining apparatus for detecting radiant energy reflected from a target zone comprising:

emission means for generating and for emitting of radiant energy;

means for redirecting the radiant energy across the target zone;

means for reflecting the radiant energy back from the target zone;

detector means for sensing the presence of radiant energy and for producing an electrical signal in response thereto;

said emission means being stationary and emitting a beam of radiant energy toward said redirecting means to be directed therefrom along a primary beam path in a first direction to the target zone;

said detector means being located along said primary beam path for detecting the radiant energy reflected from the target zone back along the primary beam path in a second direction substantially opposite to said first direction;

said redirecting means including a single-piece mirror having a substantially flat reflective surface facing away from said detector means, said single-piece mirror being configured for permitting

at least a portion of an incident beam traveling in said second direction along said primary beam path to pass through an opening adjacent to said single-piece mirror for detection by said detector means.

18. An optical position determining apparatus as claimed in claim 17, further comprising electronic processing circuit means connected to said detector means for processing of said electrical signal, said electronic processing circuit means including interface circuit means for indicating angular displacements from a reference so that when an obstruction is located within the target zone a first notch having a secondary angle and a second notch having a primary angle will appear in said electrical signal.

19. An optical position determining apparatus as claimed in claim 18, wherein said electronic processing circuit means further includes microprocessor means for calculating the vertical and horizontal coordinates of the obstruction based upon said primary and secondary angles.