Touch control system for controllable apparatus

• US RE33,151 E
• Filed: 04/17/1989
• Issued: 01/23/1990
• Est. Priority Date: 02/05/1985
• Status: Expired due to Term

• Current Assignee: Zenith Electronics Corporation (LG Corporation)
• Original Assignee: Zenith Electronics Corporation (LG Corporation)
• Inventors: Adler, Robert
• Primary Examiner(s): Brigance, Gerald
• Assistant Examiner(s): FATAHI YAR, MAHMOUD
• Application Number:
  US07/339,564
• Time in Patent Office: 281 Days
• Field of Search: 340/711, 340/712, 341/20, 341/5, 341/31, 341/23, 341/34, 178/18, 178/19, 250/221, 333/153, 310/313 B, 310/313 D, 310/313 R
• US Class Current: 345/177
• CPC Class Codes: G06F 3/0436 in which generating transducers and detecting transducers are attached to a single acoustic waves transmission substrate

Abstract

A system for recognizing touch positions along an axis on a surface associated with a touch control apparatus comprises a substrate having a surface capable of propagating surface acoustic waves and so characterized that a touch on that surface causes a perturbation of a surface wave passing through the region of touch. An input surface wave transducer coupled to the substrate surface launches a burst of surface waves on the surface. An output surface wave transducer coupled to the substrate detects received surface waves. Wave redirecting gratings derive wave components from the launched wave and redirect them across the substrate surface to the output transducer. The wave components are caused to traverse the axis along a progression of paths associated with different touch positions along the axis. Circuitry coupled to the input and output transducers initiates surface wave bursts across the substrate surface and detects tough-induced perturbations of the received waves indicative of the location of a touch along the axis.

Claims

1. For use with touch control apparatus, a system for recognizing touch positions along a predetermined axis on a surface associated with said apparatus comprising:

a substrate positioned at a location remote from said apparatus and having a surface capable of propagating surface acoustic waves and being so characterized that a touch on said substrate surface causes a perturbation, in the form of at least a partial absorption of energy, of a surface wave propagating through the region of the touch;

input surface wave transducer means coupled to said substrate surface for launching a burst of surface waves on said surface;

output surface wave transducer means coupled to said substrate for receiving said burst of surface waves;

surface wave redirecting means coupled to said substrate surface for redirecting surface wave burst components derived from said launched surface wave burst across said substrate surface to said output transducer means along a plurality of paths of different lengths which are respectively associated with different positions along said axis on said substrate surface; and

circuit means coupled to said input and output transducer means for initiating surface wave bursts on said substrate surface and for detecting touch-induced perturbations of received wave burst components, said circuit means including means for determining, by an analysis based on the transit time of the detected perturbed wave burst component, which of said plurality of paths was traversed by the touch-perturbed wave burst component and thus the location of the touch along said axis of said substrate surface.

2. For use with touch control apparatus, a system for recognizing touch positions along a predetermined coordinate axis on a surface associated with said apparatus comprising:

a substrate positioned at a location remote from said apparatus and having a surface capable of propagating surface acoustic waves and being so characterized that a touch on said surface causes a perturbation, in the form of at least a partial absorption of energy, of a surface wave propagating through the region of the touch;

combined input-output surface wave transducer means coupled to said substrate surface for launching a burst of surface waves on said surface and for receiving said burst and developing an output therefrom;

surface wave redirecting means coupled to said substrate surface including first means for redirecting surface wave burst components derived from said launched surface wave burst across said substrate surface and reflective means for reflecting them back to said input/output transducer means along a plurality of paths of different lengths which are respectively associated with different positions along said coordinate axis on said substrate surface; and

circuits means coupled to said input-output transducer means for initiating surface wave bursts on said substrate surface and for detecting touch-induced perturbations of received wave burst components, said circuit means including means for determining, by an analysis based on the transit time of the detected perturbed wave burst component, which of said plurality of paths was traversed by the touch-perturbed wave burst component and thus the locatioin of the touch along said coordinate axis of said substrate surface.

3. For use with touch control apparatus, a system for recognizing touch positions along a predetermined coordinate axis on a surface associated with said apparatus comprising:

a substrate positioned at a location remote from said apparatus and having a surface capable of propagating surface acoustic waves and being so characterized that a touch on said surface causes a perturbation, in the form of at least a partial absorption of energy, of a surface wave propagating through the region of the touch;

input surface wave transducer means coupled to said substrate surface for launching a burst of surface waves on said surface;

output surface wave transducer means coupled to said substrate for receiving said burst of surface waves;

surface wave redirecting means coupled to said substrate surface for redirecting surface wave burst components derived from said launched surface wave burst across said substrate surface to said output transducer means along a plurality of paths of different lengths which are respectively associated with different positions along said coordinate axis on said substrate surface, said output transducer means extending in the direction of said coordinate axis and being of such length as to intercept each of said plurality of paths; and

circuit means coupled to said input and output transducer means for initiating surface wave bursts on said substrate surface and for detecting touch-induced perturbations of received wave burst components, said circuit means including means for determining, by an analysis based on the transit time of the detected perturbed wave burst component, which of said plurality of paths was traversed by the touch-perturbed wave burst component and thus the location of the touch along said coordinate axis of said substrate surface.

4. For use with touch control apparatus, a system for recognizing touch positions along a predetermined coordinate axis on a surface associated with said apparatus comprising:

a substrate positioned at a location remote from said apparatus and having a surface capable of propagating surface acoustic waves and being so characterized that a touch on said substrate surface causes an amplitude reduction, in the form of at least a partial absorption of energy, of a surface wave propagating through the region of the touch;

input surface wave transducer means coupled to said substrate surface for launching a burst of surface waves on said surface;

output surface wave transducer means coupled to said substrate for receiving said burst of surface waves;

surface wave redirecting means including a reflective array coupled to said substrate surface for deriving surface wave burst components from said launched surface wave burst and redirecting them across said substrate surface to said output transducer means along a plurality of paths of different lengths which are respectively associated with different positions along said coordinate axis on said substrate surface, said reflective array having an increasing reflectivity in a direction away from said input transducer means, to at least partially compensate for the fall-off in wave amplitude with increasing wave path length;

circuit means coupled to said input and output transducer means for initiating surface wave bursts on said substrate surface and for .[.detocting.]. .Iadd.detecting .Iaddend.the touch-induced amplitude damping of received wave burst components;

said circuit means including means for determining, by an analysis based on the transit time of the detected amplitude-damped wave burst component, which of said plurality of paths was traversed by the touch-damped wave burst component and thus the location of the touch along said coordinate axis of said substrate surface.

5. The system defined by claim 4 wherein said reflective array has, in said direction away from said input transducer means, selected array elements eliminated in progressively decreasing proportion to effect said increasing reflectivity.

6. The system defined by claim 4 wherein said reflective array has, in said direction away from said input transducer means, the reflectivity of the individual array elements increasing.

7. For use in a controllable touch panel apparatus, a system for recognizing touch positions along a predetermined coordinate axis on a surface associated with said apparatus comprising:

a substrate positioned at a location remote from said apparatus and having a surface capable of propagating surface acoustic waves and being so characterized that a touch on said surface causes a perturbation, in the form of at least a partial absorption of energy, of a surface wave propagating through the region of the touch;

input surface wave transducer means coupled to said substrate surface for launching a burst of surface waves on said surface;

output surface wave transducer means coupled to said substrate surface for receiving said burst of surface waves;

surface wave redirecting means for redirecting surface wave burst components derived from said launched surface wave burst across said substrate surface to said output tranducer means along a plurality of paths of different lengths which are respectively associated with different positions along said coordinate axis on said substrate surface, said surface wave redirecting means comprising discrete groups of wave-reflective elements spaced in the direction of said coordinate axis such that said paths are non-overlapping and the output of said output transducer means consists of pulses whose respective transit times are directly proportional to the lengths of the paths traversed by the pulses over said substrate surface; and

circuit means coupled to said input and output transducer means for initiating surface wave bursts on said substrate surface and for detecting touch-induced perturbations of received wave burst components, said circuit means including means for determining, by an analysis based on the timing of the pulse or pulse void associated with a perturbed wave burst component, which of said plurality of paths was traversed by the touch-perturbed wave burst component and thus the location of the touch along said coordinate axis of said substrate surface.

8. For use in a controllable touch panel display apparatus, a system for recognizing touch positions along a predetermined coordinate axis on a surface of said apparatus comprising:

a display substrate positioned at a .[.local.]. .Iadd.location .Iaddend.remote from said apparatus and having a surface capable of propagating surface acoustic waves and being so characterized that a touch on said surface causes an amplitude damping, in the form of at least a partial absorption of energy, of a surface wave propagating through the region of the touch;

input surface wave transducer means coupled to said substrate surface for launching a burst of surface waves on said surface in a first direction parallel to said coordinate axis;

output surface wave transducer means coupled to said substrate surface for receiving said burst of surface waves;

first surface wave reflecting means coupled to said substrate surface for deriving surface wave burst components from said surface wave burst and reflecting said burst components across said display surface, and second surface wave reflecting means coupled to said substrate surface for redirecting said surface wave burst components reflected across said display surface to said output transducer means in a second direction opposite to said first direction, said first and second reflecting means causing said wave burst components to traverse said display surface substantially orthogonally to said coordinate axis along a progression of paths which are respectively associated with different positions along said coordinate axis on said display surface;

circuit means coupled to said input and output transducer means for initiating surface wave bursts across said surface and for detecting touch-induced dampings of the received waves, said circuit means including means for determining by an analysis based on the transit time of the detected damped wave, which of said plurality of paths was traversed by the touch-damped wave and thus the location of the touch along said coordinate axis of said display surface.

9. For use in a controllable touch panel display apparatus, a system for recognizing touch positions along a predetermined coordinate axis on a surface of said apparatus comprising:

a display substrate positioned at a location remote from said apparatus and having a surface capable of propagating surface acoustic waves and being so characterized that a touch on said surface causes an amplitude damping, in the form of at least a partial absorption of energy, of a surface wave propagating .[.thorugh.]. .Iadd.through .Iaddend.the region of the touch;

input surface wave transducer means coupled to said substrate surface for launching a burst of surface wave on said surface in a first direction parallel to said coordinate axis;

output surface wave transducer means coupled to said substrate surface for receiving said burst of surface waves;

first surface wave reflecting means for deriving surface wave burst components from said surface wave burst and reflecting said burst components across said display surface, and second surface wave reflecting means for redirecting said surface wave burst components reflected across said display surface to said output transducer means in a second direction opposite to said first direction, said first and second reflecting means causing said wave burst components to traverse said display surface substantially orthogonally to said coordinate axis along a progression of paths which are respectively associated with different positions along said coordinate axis on said display surface, said first reflecting means having an increasing reflectivity, and said second reflecting means having a corresponding decreasing reflectivity, in the direction of wave propagation to at least partially compensate for the fall-off in wave amplitude with increasing path length; and

circuit means coupled to said input and output transducer means for initiating surface wave bursts across said surface and for detecting touch-induced damping of the received waves, said circuit means including means for detecting the output from said output transducer means to develop an electrical amplitude characterization of said perturbation and for developing an output signal representing the timing of said characterization of said perturbation, and thus an indication of which of said plurality of paths was traversed by the touch-damping wave and thereby the location of the touch along said coordinate axis of said display surface.

10. For use in a controllable touch panel angular coordinate display apparatus, a system for recognizing touch positions at different angles on a display surface of said apparatus, comprising:

a substrate positioned at a location remote from said apparatus and having a surface capable of propagating surface acoustic waves and being so characterized that a touch on said surface causes a perturbation, in the form of at least a partial absorption of energy, of a surface wave propagating through the region of the touch;

input surface wave transducer means coupled to said substrate surface for launching a burst of circular surface waves which radiate outwardly across the display surface from the apparent center point of the coordinate system;

output surace wave transucer means coupled to said substrate surface for receiving said burst of surface waves;

surface wave redirecting means coupled to said substrate surface and located beyond the display surface for redirecting surface wave burst components derived from said surface wave burst to said output transducer means along a plurality of paths of different lengths which are respectively associated with different angular positions on said display surface; and

circuit means coupled to said input and output transducer means .[.or.]. .Iadd.for .Iaddend.initiating surface wave bursts on said surface and for detecting touch-induced perturbations of received wave burst components, said circuit means including means for determining, by an analysis based on the transit time of the detected perturbed wave burst component, which of said plurality of paths was traversed by the touch-perturbed wave burst component and thus the angular location of the touch on said display surface.

11. For use with controllable graphics display apparatus, an arrangement for recognizing and locating a momentary, intentional absorption of acoustic .[.ave.]. .Iadd.wave .Iaddend.energy propagating along at least one of a multiplicity of paths, said arrangement comprising:

a substrate positioned at a location remote from said apparatus and having a surface capable of propagating surface acoustic waves;

an input transducer coupled to said substrate surface and responsive to an input signal for launching acoustic surface waves along a first path on said surface;

a first reflective grating comprising an array of reflective elements disposed along said first path, with said elements effectively arranged at like angles of incidence to the longitudinal axis of said first path, for extracting from said surface wave a multiplicity of wave components and for directing said wave components across said substrate surface along a like multiplicity of paths each disposed at an angle to said axis of said first path;

an output transducer, for developing an electrical output signal upon receipt of surface acoustic wave energy, also coupled to said substrate surface at the terminus of a second path on said surface;

a second reflective grating comprising an array of reflective elements disposed along said second path and effectively arranged at like angles of incidence to the longitudinal axis of said second path for intercepting said wave components and for redirecting said intercepted wave components along said second path toward said output transducer; and

means coupled to said output transducer for utilizing a change in amplitude of said ouput signal, attributable to an intentioanl absorption of energy from at least one of said extracted wave components, to identify a coordinate for the location of said intentional absorption.

12. An arrangement of the type set forth in claim 11 in which said substrate comprises an isotropic medium.

13. An arrangement of the type set forth in claim 12 in which said substrate comprises a tablet.

14. An arrangement of the type set forth in claim 13 in which said tablet is formed of a sheet of glass.

15. An arrangement of the type set forth in claim 12 in which said substrate comprises the faceplate of an image display device.

16. An arrangement of the type set forth in claim 11 in which said second path is disposed parallel to said first path.

17. An arrangement of the type set forth in claim 14 in which said angles of incidence of said reflective elements to their respective paths are approximately 45 degrees.

18. An arrangement of the type set forth in claim 11 in which said multiplicity of paths are disposed at approximately 90 degrees to said axis of said first path.

19. An arrangement of the type set forth in claim 11 in which the configuration of said second reflective grating is a mirror image of the configuration of said first reflective grating.

20. An arrangement of the type set forth in claim 17 in which the spacing between adjacent ones of said elements of said gratings is a multiple of one wavelength of the frequency of said acoustic surface waves.

21. Apparatus for use with a touch controllable system capable of analyzing touch-induced perturbations of surface acoustic waves to identify touched positions along a predetermined coordinate axis on a touch surface of said apparatus, said apparatus comprising:

a substrate positioned at a location remote from said apparatus having a touch surface capable of propagating surface acoustic waves such that a touch on said surface causes a perturbation, in the form of at least a partial absorption of energy, of a surface wave propagating through the region of the touch;

input surface wave transducer means mechanically and acoustically coupled to said touch surface of said substrate and useful when excited for launching a burst of surface acoustic waves on said surface along a first path;

output surface wave transducer means, for developing an electrical output signal upon receipt of surface acoustic wave energy, also mechanically and acoustically coupled to said substrate surface at the terminus of a second path on said surface; and

means including an array of wave reflective elements disposed in or on said touch surface of said substrate along said first path, said array of elements being so configured as to direct surface wave components derived from said burst across said touch surface of said substrate in a multitude of transverse paths disposed substantially perpendicular to said coordinate axis.