Elo Touchsystems, Inc.

Touch Panel Systems Corporation

Daicel Chemical Industries, Ltd.

Hiroshi Kaneda

Joel Christopher Kent

Shigeki Kambara

Shigeki Kanbara

Robert J Adler

Arie Ravid

Paulo Irulegui Gomes

Masao Takeuchi

Bruce W Maxfield

Masaki Takebe

Keiichi Kamon

An auto distinction system images an assembled fiber band which continuously moves on the front side of a background plate applies sync-separating to a video signal by a sync-separating circuit, and clamps the video signal by a clamping circuit. Based on the clamped image signal, the characteristic information containing the defect information of the assembled fiber band is detected, and the defect information is extracted from the detected characteristic information. The clamped image signal is supplied to a noise-eliminating circuitand a defect signal concerning the thickness of the assembled fiber band is extracted. Based on the extracted signal and a reference signal with respect to the information, suitability of the defect information is discriminated by a distinction circuit. When the results of distinction are defective, the results are announced. The characteristic information can be used for process control by being supplied to an external computer.

Auto distinction system

An object of the present invention is to provide a coordinate input device of touch-type capable of giving an electric signal to a transducer, even if a piezoelectric vibrator having electrodes on both surfaces thereof is employed. A device according to the present invention comprises: acoustic wave transducers (piezoelectric vibrators)and, each functioning for oscillating a bulk wave (a first wave) toward a top surfaceof a substrate; a planar wiringformed on a back surface of the substrateby the method such as transfer printing with conductive paste, for supplying said piezoelectric vibrator with electric power; a connecting devicefor connecting said planar wiring with an electrode of each of said acoustic wave transducersand; diffractive acoustic wave mode couplers, each functioning for converting said bulk wave into a surface acoustic wave (a second wave) and vice versa; and a means for detecting a scatter in the surface acoustic wave (the second wave) on the top surface of said substrate. Employing the combination of the planar wiring and the connecting device can resolve the problem of fragility associated with a cable wiring even in the piezoelectric vibrator having the electrodes on both surfaces thereof.

Acoustic contact detecting device

A coordinate input device of touch-type capable of giving an electric signal to a transducer, even if said transducer is disposed on a back surface of a substrate. The device contains acoustic wave transducers (piezoelectric vibrators), each functioning for oscillating a bulk wave (a first wave) toward a top surface of a substrate; a planar wiring formed on a back surface of the substrate by, e.g., transfer printing with conductive paste, for supplying the piezoelectric vibrator with electric power; diffractive acoustic wave mode couplers, each functioning for converting said bulk wave into a surface acoustic wave (a second wave) and vice versa; and a detector to detect scatter in the surface acoustic wave on the top surface of the substrate. Employing the planar wiring allows the wiring to be disposed even on the back surface of the substrate and also it may resolve the problem of fragility associated with a cable wiring.

Acoustic touch sensor

A method and apparatus for adapting an acoustic touchscreen controller to the operating frequency requirements of a specific touchscreen are provided. The adaptive controller can either utilize look-up tables to achieve the desired output frequency or the it can use a multi-step process in which it first determines the frequency requirements of the touchscreen, and then adjusts the burst frequency characteristics, the receiver circuit center frequency, or both in accordance with the touchscreen requirements. In one embodiment, the adaptive controller compensates for global frequency mismatch errors. In this embodiment a digital multiplier is used to modify the output of a crystal reference oscillator. The reference oscillator output is used to control the frequency of the signal from the receiving transducers and/or to generate the desired frequency of the tone burst sent to the transmitting transducers. In another embodiment that is intended to compensate for both global and local frequency variations, the adaptive controller uses a digital signal processor. The digital signal processor, based on correction values contained in memory, defines a specific center frequency which preferably varies according to the signal delay, thus taking into account variations caused by localized variations in the acoustic wave reflective array. In yet another embodiment, a non-crystal local oscillator is used to provide the reference signal in the adaptive controller. The use of such an oscillator allows the controller to be miniaturized to a sufficient extent that it can be mounted directly to a touchscreen substrate. A feedback loop is used to compensate for oscillator drift. A discriminator circuit determines the degree of deviation from the desired frequency. The output from the discriminator is used to adjust the frequency of the local oscillator such that it tracks the frequency of the touchscreen.

Adaptive frequency touchscreen controller employing digital signal processing

An acoustic touch sensing device, comprising a substrate, having a surface; and an acoustic wave transducer, transducing a bulk wave in said substrate propagating through said substrate along an axis intersecting said surface, wherein energy of said bulk wave is coupled to a wave having a converted wave mode with appreciable energy at said surface and propagating along said surface. The device may include a set of scattering centers to couple the bulk wave to a Rayleigh wave or plate wave. The Rayleigh wave or plate wave may be dispersed over a region of the substrate, and analyzed to detect a perturbation indicative of a position of touch.

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Himeji, Japan

Hiroshi Kaneda