Computer graphics processing and selective visual display system – Display peripheral interface input device – Touch panel
Patent
1995-01-23
1998-02-10
Powell, Mark R.
Computer graphics processing and selective visual display system
Display peripheral interface input device
Touch panel
G06F 303
Patent
active
057174342
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ultrasonic touch system, having a substrate and an ultrasonic transducing system on one end surface thereof, for sensing a touch on the end surface of the substrate with a finger or other things, the ultrasonic transducing system comprising ultrasonic input and output devices, composed of at least one interdigital transducer, respectively.
2. Description of the Prior Art
Conventional touch panels arc classified into two types, resistance film-type and ultrasonic type. The resistance film-type touch panel has an electrically conductive transparent film, the magnitude of the resistance of the transparent film changing when the transparent film is touched. The resistance film-type touch panel operating under low power consumption has some problems with response time, sensitivity, durability and others. The ultrasonic type touch panel has an acoustically vibrating nonpiezoelectric plate in which the vibration decreases when the nonpiezoelectric plate is touched. Conventional methods and devices for generating the acoustic vibration on a nonpiezoelectric plate include vibrating the plate indirectly with a wedge-shaped transducer with a bulk wave vibrator, vibrating the plate directly by a piezoelectric thin film transducer, and other means. The wedge-shaped transducer is used for non-destructive evaluation by ultrasound and for others and uses a comparatively low frequency because of the difficulty with the manufacturing accuracy of the wedge angle and so on. The piezoelectric thin film transducer, in which a piezoelectric thin film made from ZnO and others is mounted on a nonpiezoelectric plate with interdigital transducers generating acoustic vibration thereon, is used as a high frequency device for the reason that the interdigital transducer shows various transmission characteristics according to the structure thereof. However, the piezoelectric thin film transducer has operation frequencies limited to the UHF and VHF bands, and has some problems with fabrication and mass-production. Thus, there are some problems with response time, sensitivity, durability, manufacture, mass-production and others in conventional touch panels having limited operating frequencies.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a touch system capable of generating an acoustic vibration on a substrate with high efficiency.
Another object of the present invention is to provide a touch system capable of sensing a touch on the substrate with a high sensitivity and a quick response time.
Another object of the present invention is to provide a touch system excellent in durability, manufacture, mass-production and others.
A still other object of the present invention is to provide a touch system operating under low power consumption with low voltage.
A still further object of the present invention is to provide a touch system with a small size which is very light in weight and has a simple structure.
According to one aspect of the present invention there is provided a touch system comprising a substrate and at least an ultrasonic transducing system on one surface Z1 of the substrate, the ultrasonic transducing system comprising at least one interdigital transducer P and at least one interdigital transducer Q corresponding to the interdigital transducer P.
According to another aspect of the present invention there is provided a means for applying the interdigital transducer P with an electric signal having a frequency approximately corresponding to the interdigital periodicity of the interdigital transducer P, and then generating an acoustic wave, having a wavelength approximately equal to the interdigital periodicity on the surface Z1.
According to another aspect of the present invention there is provided a means for delivering an electric signal, having a frequency approximately corresponding to the wavelength of the acoustic wave on the end surface Z1, from the interdigital transducer Q, the interdigital transduce
REFERENCES:
patent: 3807831 (1974-04-01), Soref
patent: 3975085 (1976-08-01), Yamada et al.
patent: 4173009 (1979-10-01), Toda
patent: 4236156 (1980-11-01), Eden
patent: 4296348 (1981-10-01), Toda
patent: 4636786 (1987-01-01), Haertling
patent: 4908542 (1990-03-01), Solie
patent: 5017913 (1991-05-01), Kaneko et al.
patent: 5095215 (1992-03-01), Shorrocks et al.
patent: 5117270 (1992-05-01), Toda
patent: 5135295 (1992-08-01), Jen et al.
LandOfFree
Ultrasonic touch system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ultrasonic touch system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ultrasonic touch system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2080707