Touch detection
First Claim
1. A touch detection device comprising:
- a substrate for providing a base for the device;
plurality of sensors for detecting acoustic waves and converting acoustic energy to electrical energy;
an analog to digital converter for converting analog signal to digital signal, a controller and an algorithm for processing the digital signal and finding the touch location by means of calculating the ratio of time of arrival differences of acoustic waves from the touch point to plurality of sensors and comparing these ratios with those stored in the storage unit.
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Accused Products
Abstract
A touch detection device for detecting touches on a given surface. The inventive device includes a surface where a touch generates acoustic waves, transducers that detect these waves, a controller that calculate the location of the touch and a host device where the touch position is used to communicate with the application program. The screen is formed from any material that is capable of propagating acoustic waves. Plurality transducers are placed on the screen. These transducers detect acoustic waves generated on the screen. The screen is calibrated by touching it once and a map of arrival time ratios are generated and saved in the storage unit. During the real time operation, a touch on the screen generates acoustic waves that are detected by transducers. The output of each transducer is sent to a controller unit where the time differences and their ratios are calculated and compared to time ratios in the storage unit to detect the touch location.
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Citations
17 Claims
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1. A touch detection device comprising:
- a substrate for providing a base for the device;
plurality of sensors for detecting acoustic waves and converting acoustic energy to electrical energy;
an analog to digital converter for converting analog signal to digital signal, a controller and an algorithm for processing the digital signal and finding the touch location by means of calculating the ratio of time of arrival differences of acoustic waves from the touch point to plurality of sensors and comparing these ratios with those stored in the storage unit. - View Dependent Claims (2, 3, 4)
- a substrate for providing a base for the device;
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5. A touch detection device comprising:
- a substrate for providing a base for the device;
plurality of sensors for detecting acoustic waves and converting acoustic energy to electrical energy;
an analog to digital converter for converting analog signal to digital signal, a controller for processing digital signal and for detecting the touch position and communicating the location to a host computer;
an algorithm for calculating the touch location comprising steps;Finding the arrival time differences of acoustic waves between several sensor pairs; Finding the ratio of time differences; Correlating the ratio of time differences with the ratio of time differences in the storage unit; Finding the touch location based on the correlation results. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13)
- a substrate for providing a base for the device;
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14. A touch detection device comprising:
- a substrate for providing a base for the device;
plurality of sensors for detecting acoustic waves and converting acoustic energy to electrical energy;
an analog to digital converter for converting analog signal to digital signal, a controller for processing the digital signal and for detecting the touch position and communicating the location to a host computer;
an algorithm for calculating the location of sensors and calculating arrival time ratios based on a single touch on the screen, the algorithm comprising the following steps;Touching one or more predetermined locations on the screen; Measuring the arrival times of acoustic waves to a sensor where its location is known; Calculating the ratio of arrival time differences; Finding the locations of other sensors by using time difference ratios; Calculating ratios for different points on the screen therefore generating a map for the screen; Storing the generated map in a storage device. - View Dependent Claims (15, 16, 17)
- a substrate for providing a base for the device;
Specification