Tritech Microelectronics International Ltd.

Tritech Microelectronics, Ltd

Maisy Mun Ng

Swee Hock Lim

Eng Yue Ong

Xia Geng

Chow Fong Chan

Sang Kong Chan

Chong Lim Neoh

Jie Liang

Kheng Boon Peh

A method and system for issuing pen-input commands from a computer system to a controller for a touchpad to initialize the controller to the desired operating mode for the touchpad. The touchpad may emulate the function of a mouse pointing device or provide absolute coordinates of a pointed object such as human finger, a stylus, or a pen upon the touchpad. The pen-input commands will set the autocursor mode and boundaries for the edgezone and the deadzone upon the touchpad, the times for the presence detect signal to create the stroke signal, the threshold of movement of the pointed object upon the touchpad necessary to send the mouse protocols to the computer system, the mode of the pen-input mouse controller is to operate, whether the pen-input mouse controller is to send the mouse protocol or the pen-input computer interface protocol to the computer system, the averaging algorithm to used by the absolute coordinate calculator, the minimum pressure required to activate the touchpad, the parameters for the autocursor mode operation, and the time parameters for the autopower save circuit.

Command set for touchpad pen-input mouse

Systems and methods for the detection of motions of a pointed object upon a writing surface such as a touchpad is disclosed. The motions will be detected and converted in a multiplexing analog-to-digital converter to digital codes representing the location of the pointed object and the pressure of the pointed object upon the touchpad. The location and the pressure will be translated into a pen detect signal indicating the presence of the pointed object upon the touchpad. The pen detect signal will be translated into a stroke signal to interpret a single tap, a double tap, and a tap and drag of the pointed object on the touchpad. The digital codes will be averaged to minimize noise and formed into an absolute coordinates digital code. The absolute coordinate digital code, the pressure digital code, and the pen detect signal will be converted to a touchpad-computer interface protocol. Further, multiple sets absolute coordinates will translated into a relative motion code. The absolute coordinates will be interpreted by an autocursor controller to determine if the pointed object has transited between a workzone and an edgezone of the touchpad to generate an autocursor code. The relative motion code, the stroke signal, and the autocursor code will converted to an industry standard computer input mouse protocol. An autopower control circuit and a battery gauge circuit will determine and control the battery condition.

Touchpad pen-input and mouse controller

Systems and methods for the detection of motions of a pointed object upon a writing surface such as a touchpad is disclosed. The motions will be detected and converted in a multiplexing analog-to-digital converter to digital codes representing the location of the pointed object and the pressure of the pointed object upon the touchpad. The location and the pressure will be translated into a pen detect signal indicating the presence of the pointed object upon the touchpad. The digital codes will be averaged to minimize noise created by vibrations and variations in the motions of the pointed object held by the human hand and formed into an absolute coordinate digital code. The absolute coordinate digital code, the pressure digital code, and the pen detect signal will be converted to a touchpad-computer interface protocol for transmission to a computer system for further processing. The pen detect signal will be sense to determine if the pointed object has not been in contact with the touchpad for a long period of time and remove power from the circuitry controlling the touchpad. For battery power operations, a battery sense line will be connected to the multiplexing analog-to-digital converter to create a battery power set of digital codes which are manipulated in a battery gauge circuit to create a battery condition set of digital codes which are transmitted to the computer system.

Touchpad pen-input controller

The present invention provides a voltage controlled oscillator with improved noise immunity and minimized variation due to manufacturing process, power supply and operating temperature changes. The voltage controlled oscillator consists of fully differential connected ring oscillator that includes a plurality of differentially connected delay elements. The ring oscillator responds to a control current signal for controlling the frequency of oscillation. A voltage to current converter converts the input tuning voltage to an output current for the controlling of the ring oscillator. The delay element consists of two source coupled P-channel transistors connected to a current source. The drains of the P-channel transistors are each connected to a voltage controlled impedance that changes the delay characteristics of the delay element in response to the input tuning voltage. A voltage reference generator provides the reference voltage necessary to determine the amplitude out of the delay element and is insensitive to variations due to manufacturing process, power supply, and operating temperature. A fully differential comparator provides symmetrical loading for the ring oscillator and the high gain necessary to provide the output drive capability.

Embedded voltage controlled oscillator with minimum sensitivity to

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.

Growing community of inventors

Singapore, Singapore

Maisy Mun Ng