Handheld device having ultrasonic transducer for axial transmission of acoustic signals

• US 20060273696A1
• Filed: 08/15/2006
• Published: 12/07/2006
• Est. Priority Date: 07/22/2002
• Status: Active Grant

• Current Assignee: Minoru Toda
• Original Assignee: Minoru Toda
• Inventors: Toda, Minoru
• Granted Patent: US 7,342,350 B2
• Time in Patent Office: Days
• US Class Current: 310/348
• CPC Class Codes: A61B 8/4209 by using holders, e.g. positioning frames
• CPC Class Codes: B06B 1/0655 of cylindrical shape
• CPC Class Codes: B06B 1/0688 with foil-type piezoelectric elements, e.g. PVDF
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: Y10S 310/80 Piezoelectric polymers, e.g. PVDF

Abstract

A handheld stylus having an elongated housing, a writing and drawing implement disposed within the housing and including a tip extending through an opening at an end of the housing where ultrasonic waves radiate therefrom and are used for determining a position of the stylus; and at least one ultrasonic transducer disposed within the housing. The transducer may be a cylindrical piezoelectric transducer having a holder and a cylindrical piezoelectric film spanning between at least two spaced apart cylindrical surfaces of the holder, or a flat transducer having a diaphragm, and a piezoelectric material disposed on a surface of the diaphragm.

Claims

1-8. -8. (canceled)

9. A stylus comprising:

an elongated housing defining an internal bore and having an opening at an end thereof that communicates with the internal bore;

a writing and drawing implement disposed within the bore of the housing, the implement having a tip extending through the opening at the end of the housing; and

a transducer disposed within the bore, the transducer comprising;

a holder having at least two spaced apart cylindrical surfaces;

a cylindrical piezoelectric film spanning between the at least two spaced apart cylindrical surfaces of the holder;

an outer electrode segment disposed on an outer surface of the film; and

an inner electrode segment disposed on an inner surface of the film;

wherein the transducer radiating acoustic energy substantially along a longitudinal axis of the stylus in response to an excitation voltage applied to the film via the electrode segments such that the radiating acoustic energy propagates along the bore toward the end and exits at the opening.

10. The stylus of claim 9, further comprising a conical reflector disposed external to the opening, the tip of the implement extending through the conical reflector, the conical reflector responsive to the radiating acoustic energy for redirecting the radiating acoustic energy at an angle substantially perpendicular to the longitudinal axis of the stylus.

11. The stylus of claim 9, further comprising a cover spaced from the outer surface of the film, the cover including a flange restricting propagation of the radiating acoustic energy along a propagation path defined along an exterior of the film.

12. The stylus of claim 11, further comprising a reflector disposed at an end of the transducer for redirecting the radiating acoustic energy toward the opening of the housing.

13. The stylus of claim 10, further comprising a reflector disposed at an end of the transducer for redirecting the radiating acoustic energy toward the opening of the housing.

14. The stylus of claim 9, further comprising a reflector disposed at an end of the transducer for redirecting the radiating acoustic energy toward the opening of the housing.

15. The stylus of claim 9, wherein:

the at least two spaced apart cylindrical surfaces comprising a plurality of spaced apart cylindrical surfaces;

the film spanning between at least two pairs of the plurality of spaced apart cylindrical surfaces of the holder;

the outer electrode segment comprising a plurality of outer electrode segments; and

the inner electrode segment comprising a plurality of inner electrode segments.

16. The stylus of claim 15, further comprising a conical reflector disposed external to the opening, the tip of the implement extending through the conical reflector, the conical reflector responsive to the radiating acoustic energy for redirecting the radiating acoustic energy at an angle substantially perpendicular to the longitudinal axis of the stylus.

17. The stylus of claim 15, further comprising a cover spaced from the outer surface of the film, the cover including a flange restricting propagation of the radiating acoustic energy along a propagation path defined along an exterior of the film.

18. The stylus of claim 17, further comprising a reflector disposed at an end of the transducer for redirecting the radiating acoustic energy toward the opening of the housing.

19. The stylus of claim 16, further comprising a reflector disposed at an end of the transducer for redirecting the radiating acoustic energy toward the opening of the housing.

20. The stylus of claim 15, further comprising a reflector disposed at an end of the transducer for redirecting the radiating acoustic energy toward the opening of the housing.

27. The stylus of claim 9, wherein the excitation voltage has a frequency which has a wavelength in a propagation medium, wherein about half of the wavelength is more than a width of each of the electrode segments.

28. The stylus of claim 27, further comprising a drive circuit for sequentially applying the excitation voltage to the electrode segments of the transducer.

29. The stylus of claim 9, further comprising a drive circuit for sequentially applying the excitation voltage to the electrode segments of the transducer.

30. The stylus of claim 15, wherein the excitation voltage has a frequency which has a wavelength in a propagation medium, wherein about half of the wavelength is more than a width of each of the electrode segments.

31. The stylus of claim 30, further comprising a drive circuit for sequentially applying the excitation voltage to the electrode segments of the transducer.

32. The stylus of claim 15, further comprising a drive circuit for sequentially applying the excitation voltage to the electrode segments of the transducer.

33. The stylus of claim 9, wherein the holder is a defined by a section of the implement which is disposed within the bore.

34. The stylus of claim 10, wherein the holder is a defined by a section of the implement which is disposed within the bore.

35. The stylus of claim 13, wherein the holder is a defined by a section of the implement which is disposed within the bore.

36. The stylus of claim 14, wherein the holder is a defined by a section of the implement which is disposed within the bore.

63. The stylus of claim 9, wherein the holder restricts propagation of the radiating acoustic energy along a propagation path defined within an interior of the film.

64. The stylus of claim 15, wherein the holder restricts propagation of the radiating acoustic energy along a propagation path defined within an interior of the film.

21-26. -26. (canceled)

37-62. -62. (canceled)

65-68. -68. (canceled)