Tritech Microelectronics International Ltd.

Freesystems Pte Ltd

Chong Lim Neoh

Sang Kong Chan

Maisy Mun Ng

Described is a personal on-demand audio entertainment system with a base unit attached to a personal computer or other source, a headphone unit and a remote control unit. The base unit transmits digital audio content to the headphone unit using infrared, radio frequency, magnetic or electromagnetic coupling. These data are stored in solid-state memory within the headphone unit. In the headphone unit, the stored digital audio content is converted to analog audio signals, amplified and sent to transducers for conversion to audio signal for the listener during playback. The system is designed such that playback may occur during the downloading process. The remote control unit also uses infrared, radio frequency, magnetic or electromagnetic coupling for communication to the headphone unit. This communication is made using a different channel and does not interfere with the audio data downloading. The remote control unit has a display and allows for control of player functions and modification of audio characteristics such as volume, bass, treble, balance, etc.

Personal on-demand audio entertainment device that is untethered and allows wireless download of content

Described is a device and method using an interactive process to improve the listening experience for a user of headphones or hearing aids. The system uses a sound source such as a PC or similar device. Programming of the headphone or hearing aid is accomplished using a process delivered by the sound source. The user is prompted to listen to various signals thereby testing the frequency response of each ear and headphone combination. Once the user testing is completed, individualized compensation coefficients are created to optimize the listening experience for the user. The coefficients would be downloaded to and stored within the hearing aids. Downloading could accomplished by wire or by wireless means such as infrared, radio frequency, magnetic or electromagnetic coupling. In headphone units, the compensation factors could be stored either within the headphones or maintained at the sound source. In addition, headphone units could be operated with or without wires (using infrared, radio frequency, magnetic or electromagnetic coupling) for downloading or audio listening.

Biaural (2channel listening device that is equalized in-stu to compensate for differences between left and right earphone transducers and the ears themselves

A digitizing tablet has an improved operation for saving power. After an input device contacts the tablet surface, resistive sheets provide analog pen position signals to a sample/track and hold circuit. Once the signals are captured by the sample/track and hold, power is removed from the resistive sheets and digitization of the analog signals is performed. During an input waiting period, power is further conserved by removing power from the sample/track and hold and analog-to-digital converter, as a separate level detect circuit detects contact with the tablet surface by an input device.

Tablet with system power saving features including reactivation by

A tablet system has an improved operation for saving power. During a digitizing period, the tablet supplies power to resistive sheets that produce analog pen position signals and to the sample and hold circuit and the analog to digital converter that operate on these signals. During a wait state, power is removed from these components and a separate circuit detects contact with the tablet surface by a pen. A pen activity circuit that uses less power is also disclosed. The pen activity detecting circuit has a resistor in circuit with the two resistive sheets. This resistor and associated circuits are independent of the normal path for signals that denote pen position and thereby allow these components to be turned off. When the pen is positioned on the tablet surface, the two resistive sheets are brought into contact in the normal way for detecting the pen position. During a period of pen inactivity, this contact produces a current in the resistor. The associated voltage is detected and power is applied to the resistive sheets and to the sample and hold circuit and analog to digital converter for normal operation.

Tablet with system power saving features including reactivation by pen

A digital tablet of the type that multiplexes pen position signals has filtering and digitizing circuits arranged in separate channels for each of the signals that is to be multiplexed. The tablet pen is connected to receive an oscillator signal and the signal is picked up at each of the four corners of the tablet and applied to the corresponding channel. The separate channels permit the filters to be made sharper. The disclosure also includes improved circuits for processing the pen position signals.

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Singapore, Singapore

Chong Lim Neoh