Touch control system and apparatus with multiple acoustic coupled substrates

• US 7,764,276 B2
• Filed: 04/18/2006
• Issued: 07/27/2010
• Est. Priority Date: 04/18/2006
• Status: Expired due to Fees

• Current Assignee: Jerry D. Schermerhorn
• Original Assignee: Jerry D. Schermerhorn
• Inventors: Schermerhorn, Jerry D.
• Primary Examiner(s): NGUYEN, KIMNHUNG T
• Application Number:
  US11/405,775
• Publication Number:
  US 20070240913A1
• Time in Patent Office: 1,561 Days
• Field of Search: 345173-179, 178 1801- 1804, 178/19.01, 178/19.02, 310/300, 310/311, 310/313.B, 310/313.D, 310/313.R, 310/314, 310/318
• 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

An apparatus and system for recognizing touch positions is comprised of multiple acoustically coupled substrates, said coupling functioning also as an environmental seal. At least one secondary substrate, with means to transmit and receive acoustic waves, is coupled to a primary substrate capable of propagating acoustic waves such that an intentional touch on the surface causes a perturbation of the waves passing through a desired region of touch detection. Said perturbation is analyzed by circuitry to determine corresponding physical position of the touch on surface.

Claims

1. A touch detection apparatus comprising:

a primary substrate having a surface capable of propagating acoustic waves and being so characterized that said surface is touch sensitive such that a touch on said surface causes a perturbation, in the form of at least a partial absorption of energy, of an acoustic wave propagating through a region of desired touch detection;

at least one transmitter secondary substrate mounted along an edge of said primary substrate;

at least one receiver secondary substrate mounted along another edge of said primary substrate opposite from said transmitter secondary substrate;

at least one input transducer, coupled to a said transmitter secondary substrate, which is operative to launch a burst of acoustic waves onto said transmitter secondary substrate;

at least one output acoustic wave transducer coupled to said receiver secondary substrate that detects received acoustic waves;

a first coupling means disposed between said transmitter secondary substrate and said primary substrate to transfer acoustic wave components to a first edge defining a first axis of the desired touch sensing area of said primary substrate surface;

a second coupling means disposed between said primary substrate and said receiver secondary substrate to transfer and redirect acoustic waves to the output transducer after propagating across the first surface at least once such that said wave components are caused to traverse said axis along a progression of paths differing in time and associated with different touch positions along the axis;

at least one wave redirecting means disposed upon at least one secondary substrate which derives wave components separated in time from a launched wave, said wave components substantially perpendicular to the launched wave; and

circuitry coupled to said input and output transducers which initiates acoustic wave bursts causing derived wave components separated in time across said primary substrate surface and detects touch-induced perturbations of said received waves indicative of the location of a touch along said axis, said circuit means also including means for determining, by an analysis based on the transit time of said detected perturbed wave burst component, which of a plurality of paths was traversed by said touch-perturbed wave burst component and thus determining the location of the touch along said axis of said substrate surface.

2. A touch detection apparatus as in claim 1 wherein said location of the touch is a function of the degree of absorbtion of acoustic energy.

3. A touch detection apparatus as in claim 1 wherein said acoustic waves travel across the surfaces of said primary and secondary substrates.

4. A touch detection apparatus as in claim 1 wherein said acoustic waves travel below the surfaces of said primary and secondary substrates.

5. A touch detection apparatus as in claim 3 wherein

said acoustic wave redirecting means includes a reflective array formed integral to said secondary substrate surface for deriving wave burst components from said launched wave burst and redirecting them along a plurality of paths of different lengths which are respectively associated with different positions along said coordinate axis on said first substrate surface, said reflective array having an increasing reflectivity along said paths greater in length to at least partially compensate for the fall-off in wave amplitude with increasing wave path length and attenuation.

6. A touch detection apparatus defined by claim 5 wherein said reflective array has, along said paths greater in length, the density of array elements increased progressively in proportion to effect said increasing reflectivity.

7. A touch detection apparatus defined by claim 5 wherein said reflective array has, along said paths greater in length, the reflectivity of the individual array elements increasing.

8. A touch detection apparatus as in claim 5 wherein said reflective array comprises individual reflectors elements created by steps oriented at an angle in the basic substrate material and formed from one the processes of etching, stamping, molding, plating and screening and firing.

9. A touch detection apparatus as in claim 5 wherein said reflective array comprises individual reflectors elements created by grooves oriented at an angle in the basic substrate material and formed from one the processes of etching, stamping, molding, plating and screening and firing.

10. A touch detection apparatus as in claim 5 wherein said reflective array comprises individual reflector elements oriented at an angle created by causing a different acoustic velocity of the waves between the reflector elements and basic secondary substrate, with reflector elements being formed by one of the processes of etching and filling in conjunction with photo resist, chemical surface treatments, physical surface treatments, plating, and screening and firing.

11. A touch detection apparatus as in claim 1 wherein the first substrate is the physical front surface of a visual display apparatus.

12. A touch detection apparatus as in claim 1 wherein the first substrate is transparent and serves as an optical filter, safety shield, or window in conjunction with a visual display apparatus.

13. A touch detection apparatus as in claim 1 wherein the secondary substrates have different physical properties than the first substrate.

14. A touch detection apparatus as in claim 13 wherein said acoustic waves experience less energy loss while propagating in said secondary substrates than when propagating in said primary substrate.

15. A touch detection apparatus as in claim 14 wherein said secondary substrates are formed from a metallic material selected from the group of aluminum, brass, steel, nickel, chrome, copper, and combinations and alloys thereof.

16. A touch detection apparatus as in claim 1 wherein

said transmitter secondary substrate associated with said output transducer is positioned near but above the said primary substrate, with said substrates substantially face to face, with the launched wave parallel to an axis along the edge of the desired touch detection region and derived wave components directed toward the desired touch detection surface, and

the acoustic coupling means said transmitter secondary substrate to said primary substrate is a coupling material with a width of only a few wavelengths of said acoustic wave, said acoustic coupling means extending along at least the entire length of the desired touch sensitive region and in contact with both the touch sensitive surface of the said primary substrate and surface conducting wave components on said transmitter secondary substrate, and further

said coupling material has the property that the bulk longitudinal acoustic wavelength is less than the wavelength of acoustic waves at or near the surface of both the first and secondary substrates, such that said acoustic wave components transverse said desired touch sensitive region of said first substrate at least once.

17. A touch detection apparatus as in claim 16 where said coupling material is selected as one of the group of an acrylic glass such as Plexiglass, an acrylic glass such as Lucite (Polymethyl methacrylate (PMMA), poly(methyl 2-methylpropenoate), an elastomer, rubber, latex, silicone, a grease, and combinations thereof.

18. A touch detection apparatus as in claim 16 wherein, at the coupling regions of a few wavelengths width, the surface of said secondary substrate is formed in said coupling region such that of the surface of said secondary and primary substrates are at a slight angle which facilitates the most efficient transfer of acoustic waves therebetween.

19. A touch detection apparatus as in claim 16 wherein

said coupling material is positioned to completely surrounding and enclosing said wave directing means located on said transmitter secondary substrate associated with an input transducer, and

said coupling material is further positioned to completely surround and enclose said wave directing means located on said receiver substrate associated with an output transducer.

20. A touch detection apparatus as in claim 19 wherein multiple wave directing means and associated coupled output and input transducers are combined into the same secondary substrate that also is formed as a bezel.

21. A touch detection apparatus as in claim 1 wherein

said receiver secondary substrate associated with said input transducer is positioned near but above the said primary substrate, with said substrates substantially face to face, with the received wave derived components parallel to an axis along the edge of the desired touch detection region and wave components received from the direction of the desired touch detection surface, and

the acoustic coupling means said receiver secondary substrate to said primary substrate is a coupling material with a width of only a few wavelengths of said acoustic wave, said acoustic coupling means extending along at least the entire length of the desired touch sensitive region and in contact with both the touch sensitive surface of the said primary substrate and surface conducting wave components on said receiver secondary substrate, and further

said coupling material has the property that the bulk longitudinal acoustic wavelength is less than the wavelength of acoustic waves at or near the surface of both the first and secondary substrates, such that said acoustic wave components transverse said desired touch sensitive region of said first substrate at least once.

22. A touch detection apparatus as in claim 21 where said coupling material is selected as one of the group of an acrylic glass such as Plexiglass, an acrylic glass such as Lucite (Polymethyl methacrylate (PMMA), poly(methyl 2-methylpropenoate), an elastomer, rubber, latex, silicone, a grease, and combinations thereof.

23. A touch detection apparatus as in claim 21 wherein, at the coupling regions of a few wavelengths width, the surface of said secondary substrate is formed in said coupling region such that of the surface of said secondary and primary substrates are at a slight angle which facilitates the most efficient transfer of acoustic waves therebetween.

24. A touch detection apparatus as in claim 21 wherein

said coupling material is positioned to completely surrounding and enclosing said wave directing means located on said transmitter secondary substrate associated with an input transducer, and

said coupling material is further positioned to completely surround and enclose said wave directing means located on said receiver substrate associated with an output transducer.

25. A touch detection apparatus as in claim 24 wherein multiple wave directing means and associated coupled output and input transducers are combined into the same secondary substrate that also is formed as a bezel.

26. A touch detection apparatus as in claim 1 comprising two axes substantially perpendicular to each other including circuitry and analysis for determining at least the location of a touch along the two axis and providing a co-ordinate location.

27. A touch detection apparatus as in claim 1 wherein a material is selected from the group of a ceramic and a glass with a thermal expansion close to that of said primary first substrate and is laminated to the back of said secondary arrays to balance stress forces between said primary and secondary substrates.

28. A system for use with a touch detection apparatus, the system recognizing intentionally touched positions along at least one predetermined axis of the apparatus by recognizing and locating a momentary intentional absorption of acoustic energy in a desired touch sensitive region, the system comprising:

a first substrate, its surface capable of propagating acoustic waves and being so characterized that it is touch sensitive such that a touch on said surface causes a perturbation, in the form of at least a partial absorption of energy, of an acoustic wave propagating through a region of desired touch detection;

at least one input transducer, coupled to a first secondary substrate, which launches a burst of acoustic waves upon that substrate;

at least one output acoustic wave transducer coupled to a secondary substrate that detects received acoustic waves;

at least one wave redirecting means on said secondary substrate which derive wave components separated in time from a launched wave;

a first coupling means disposed between said transmitter secondary substrate and said primary substrate to transfer said wave components to a first edge defining a first axis of the desired touch sensing area of said primary substrate surface; and

a second coupling means disposed between said primary substrate and said receiver secondary substrate to transfer and redirect acoustic waves to the output transducer after propagating across the first surface at least once such that said wave components are caused to traverse said axis along a progression of paths differing in time and associated with different touch positions along the axis; and

circuitry, including computation and communication means, coupled to the input and output transducers which initiates acoustic wave bursts causing derived wave components separated in time across the first substrate surface and detects touch-induced perturbations of the received waves indicative of the location of a touch along the axis, 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 determining the location of the touch along said axis of said substrate surface, and a degree of absorbtion of acoustic energy.

29. A system as in claim 28 wherein said input transducer launches said burst of acoustic waves onto the surface of said first secondary substrate.

30. A system as in claim 28 wherein said input transducer launches said burst of acoustic waves within said first secondary substrate.

31. A system as in claim 28 in which said substrate comprises an isotropic medium.

32. A system as in claim 31 in which said substrate comprises a tablet.

33. A system as in claim 32 in which said tablet is formed on a sheet of glass.

34. A system as in claim 28 in which said substrate comprises the first physically contactable surface of an image display device.

35. A system as in claim 28 for controlling images and associated functions on an image display device corresponding to detected intentional touched positions.

36. A system as in claim 28 for controlling images and associated functions on an image display device corresponding according to detected intentionally touched positions and the degree of absorbtion of acoustic energy during said intentional touch activation.

37. A touch detection apparatus comprising;

a primary substrate having a surface capable of propagating acoustic waves and being so characterized that said surface is touch sensitive such that a touch on said surface causes a perturbation, in the form of at least a partial absorption of energy, of an acoustic wave propagating through a region of desired touch detection;

at least one transmitter and receiver secondary substrate mounted along an edge of said primary substrate;

at least one transducer, coupled to said transmitter and receiver secondary substrate, said transducer operative to launch a burst of acoustic waves onto said transmitter secondary substrate, said transducer also operative to receive reflected acoustic waves;

a coupling means disposed between said transmitter and receiver secondary substrate and said primary substrate to transfer said wave components to and from a first edge defining a first axis of the desired touch sensing area of said primary substrate surface; and

at least one reflective means positioned opposite the desired touch sensitive area on the primary substrate opposite from said transmitter and receiver secondary substrate whereby wave components transit the touch sensing area twice; and

circuitry, including computation and communication means, coupled to the input and output transducer which initiates acoustic wave bursts causing derived wave components separated in time across the first substrate surface and detects touch-induced perturbations of the received waves indicative of the location of a touch along the axis, 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 determining the location of the touch along said axis of said substrate surface, and a degree of absorbtion of acoustic energy.