Optical position location apparatus

• US 4,420,261 A
• Filed: 09/02/1980
• Issued: 12/13/1983
• Est. Priority Date: 09/02/1980
• Status: Expired due to Term

• Current Assignee: Lowbar Incorporated An IL Corporation 60077 An IL Limited Partnership
• Original Assignee: Lowbar Incorporated
• Inventors: Krutsch, John R., Karlin, Richard A., Tutt, Timothy T., Barlow, Gordon A.
• Primary Examiner(s): Punter, William H.
• Application Number:
  US06/183,357
• Time in Patent Office: 1,197 Days
• Field of Search: 356/51, 356/372, 356/375-376, 356/380, 356/386-387, 356/398, 250/561, 250/221-222, 250/224, 250/578, 178/18, 340/555-557, 350/171, 350/319
• US Class Current: 356/621
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G06F 3/0423 using sweeping light beams, e.g. using rotating or vibrating mirror

Abstract

An optical position location apparatus for locating the position of an object in one or more dimensions, which relies upon one or more sources of radiant energy and distributor devices to disburse such radiant energy over a location region or window. Integrated collector assemblies positioned opposite to the distributors receive and collect the transmission of the distributed radiant energy and through reflection or refraction, transfer radiant energy to a minimum of detection locations to monitor the absence or alteration thereof. A rotating optical scanner and a detector are utilized with a continuous stationary light source to successively monitor specific location-coordinate-related portions of transmitted radiant energy and through electronic circuitry, a signal is developed to disclose, with accuracy, the location of objects within the location region "window", as well as other parameters including object size. In other embodiments, an apparatus with elements cooperating along two dimensions is capable of yielding three-dimensional object parameter information.

Claims

1. An optical position location and size determining apparatus for locating the positions of one or more objects along one or more coordinate axes of a defined sensing area, as well as for determining other measurable parameters of said one or more objects such as the sizes thereof relative to said one or more coordinate axes, said apparatus comprising:

radiant energy emission means;

radiant energy detection means;

means for distributing said radiant energy emitted by said radiant energy emission means over a location region from a position proximate to a first side of said region;

one or more integrated collector means proximate to a second side of said location region, said integrated collector means cooperating with said distributor means to receive said radiant energy distributed by said distributor means and to transmit said radiant energy to said radiant energy detection means;

signal output means operably connected to said radiant energy detection means;

shield means, said shield means to prevent ambient or stray radiant energy not transmitted from said integrated collector means from impinging said radiant energy detection means;

scanner means;

said scanner means including optical element means, said optical element means operating to direct said radiant energy received from said integrated collector means to said radiant energy detection means;

said scanner means further including motor means, said motor means being operably connected to said optical element means whereby said optical element means is made to rotate with respect to said integrated collector means;

said scanner means further including apertured mask means, said apertured mask means having a dimensioned aperture therein;

said apertured mask means cooperating with said optical element means and located in optical alignment with said optical element means and said radiant energy detection means;

said shield means and said scanner means cooperating to restrict the radiant energy received by said radiant energy detection means to that portion of said distributed radiant energy received by the portion of said integrated collector means which is instantaneously in optical alignment with the combination of said rotating optical element means, said dimensioned aperture of said apertured mask means, and said radiant energy detection means, whereby the radiant energy received by said integrated collector means may be sequentially and selectively monitored by said radiant energy detection means.

2. The invention according to claim 1 wherein said radiant energy emission means, said distributor means, said integrated collector means, and said radiant energy detection means are operably positioned within an enclosed housing member,

said location region comprising a substantially apertured area enclosed by said housing member.

3. The invention according to claim 1 wherein the apparatus includes one said radiant energy emission means, one said distributor means, one said integrated collector means, and radiant energy detection means for determining the location and/or other parameters of one or more objects along one coordinate axis.

4. The invention according to claim 1 wherein said apparatus includes two substantially separate distributor means, two substantially separate integrated collector means respectively aligned with said two distributor means, and radiant energy detection means for determining the location and/or other parameters of one or more objects along two coordinate axes.

5. The invention according to claim 1 wherein said radiant energy comprises unpolarized electromagnetic light.

6. The invention according to claim 1 wherein said radiant energy emission means comprises substantially stationary continuously emitting light source means.

7. The invention according to claim 1 wherein said optical element means comprises a sphere having fabricated therein a substantially diagonal-cut plane portion for refraction of radiant energy into and through said dimensioned aperture of said apertured mask means.

8. The invention according to claim 1 wherein said radiant energy detection means comprises photocell means.

9. The invention according to claim 1 wherein said radiant energy emission means includes blockage means to intercept and absorb radiation directed to locations other than those occupied by said distributor means.

10. The invention according to claim 1 wherein said motor means is coupled to said radiant energy emission means, to said radiant energy detection means, and to amplifier means in an electrical circuit,

said motor means further including electrical filter means in parallel connection therewith to reduce commutator noise from said motor means;

said motor means further including speed control means to produce a desired rotational speed in said motor means,

said motor means further being connection in parallel connection to said amplifier means which is, in turn, operably connected to said radiant energy detection means to receive signals therefrom.

11. The invention according to claim 1 wherein said radiant energy detection means is operably coupled via signal processing means to visual display means for visual interpretation of the radiant energy being scanned and detected by said radiant energy detection means cooperating with said scanner means.

12. The invention according to claim 1 wherein said apparatus further comprises radiation filter means interposed between said distributor means and said integrated collector means for the purpose of precluding interference from light and other radiant energies of wavelengths other than those of the intended radiant energy being emitted, distributed and collected for detection.

13. The invention according to claim 12 wherein said filter means comprises a red-and-infrared passage filter interposed between said distributor means and said integrated collector means.

14. The invention according to claim 1 wherein said distributor means distributes radiant energy at positions outside of said location region so as to describe radiant energy routes which cannot be altered or broken by objects located within said location region, the radiant energy traversing the resulting unalterable radiant energy transmission routes and detected by said radiant energy detection means thereby creating reference signals defining fixed and known positions relative to said location region.

15. The invention according to claim 1 wherein one or more of said one or more distributor means comprises a stepped echelon mirror assembly,

said stepped echelon mirror assembly comprising a plurality of faceted mirror elements;

said faceted mirror elements being individually oriented with respect to said radiant energy emission means and said location region to receive a portion of the radiant energy emitted by said radiant energy emission means and thereafter transmit it across a select portion of said location region.

16. The invention according to claim 1 wherein said radiant energy detection means comprises solid state photo detector means.

17. The invention according to claim 15 wherein said faceted mirror elements are oriented with respect to said radiant energy emission means and said location region such that the radiant energy emitted by said radiant energy emission means is transmitted across said location region in substantially parallel beams spaced substantially evenly across said location region.

18. The invention according to claim 17 wherein each of said faceted mirror elements receives a substantially equal portion of radiant energy from said radiant energy emission means.

19. The invention according to claim 1 wherein or or more of said one or more integrated collector means comprises a stepped echelon mirror assembly;

said stepped echelon mirror assembly comprising a plurality of faceted mirror elements;

said faceted mirror elements being individually oriented with respect to said location region and said radiant energy detection means to receive radiant energy from a select portion of said location region and thereafter transmit it to said radiant energy detection means.

20. The invention according to claim 15 wherein one or more of said faceted mirror elements include curved mirror surfaces for providing reflective focusing of the radiant energy.

21. The invention according to claim 19 wherein said faceted mirror elements are oriented with respect to said location region and said radiant energy detection means such that said faceted mirror elements individually receive radiant energy from portions of said location region which are substantially parallel to one another and which are spaced substantially evenly across said location region.

22. The invention according to claim 21 wherein each of said faceted mirror elements is within optical alignment with said optical element means of said scanner means for substantially equal portions of the rotation of said rotating scanner means, and wherein the incremental angular separation between the peaks of each of each said faceted mirror elements corresponds to substantially equal angular portions of the rotation of said rotating scanner means, whereby a substantially linear relationship exists between the instantaneous angular position of the optical elements means of the rotating scanner means, and the transverse location of that select portion of said location region from which radiant energy is being instantaneously received by said radiant energy detection means via said stepped echelon mirror assembly.

23. The invention according to claim 22 wherein said stepped echelon mirror assembly comprises 29 substantially individual faceted mirror elements;

each of said 29 faceted mirror elements being 0.2 inches wide with respect to a datum line defining a linear axis; and

said faceted mirror elements ranging in depth relative to a datum line parallel to said linear axis and contiguous to the outermost edge of the outermost extending faceted mirror element a distance ranging from 1.617 inches to 0.171 inches, in substantially curvilinear fashion.

24. The invention according to claim 1 wherein said signal output means comprises:

detector buffer means, said detector buffer means responding to the electrical output signal of said radiant energy detection means and generating a corresponding buffer output signal;

output discriminator means, said output discriminator means connected to the output of said detector buffer means whereby said buffer output signal maybe analyzed to determine whether said buffer output signal corresponds to the presence or absence of an object within that relevant portion of said location region which corresponds to that portion of said integrated collector means which is instantaneously in optical alignment with said scanner means and said radiant energy detection means;

said output discriminator means generating a first given output signal when said buffer output signal corresponds to the absence of an object within said relevant portion of said location region; and

said output discriminator means generating a second given output substantially distinct from said first given output signal when said buffer output signal corresponds to the presence of an object within said relevant portion of said location region.

25. The invention according to claim 24 wherein said detector buffer means comprises:

amplifier means;

said amplifier means generating said buffer output signal, said buffer output signal thereby generated comprising a first variable voltage output signal;

said amplifier means including gain determining means;

said amplifier means further including electrical filter means for supressing input signals of undesired extraneous frequencies;

said output discriminator means comprising d.c. restorer means, said d.c. restorer means designed to add or subtract a given voltage to said first variable voltage output signal;

said output discriminator means further comprising Schmitt trigger means for outputting a first logic one level output when said d.c. variable voltage second output signal rises above a first predetermined voltage level, and outputting a second logic zero level output when said second variable output signal falls below a second predetermined voltage level.