Pixart Imaging (penang) Sdn. Bhd.

Pixart Imaging Incorporated

Poh-Weng Yem

Wai-Lian Teo

A lighting control method of an optical pointing device is provided. An electric current is applied to a light emitting element within a predetermined turned-on period of an image sampling cycle, so that the light emitting element generates a light beam projected on a work surface where the optical pointing device is placed. A surface image of the work surface is captured by an image sensor within the predetermined turned-on period of the image sampling cycle. The surface image is analyzed to obtain a brightness of the surface image within the image sampling cycle. A current value of the electric current applied to the light emitting element according to the brightness of the surface image is determined before a starting point of a next image sampling cycle, such that a brightness of another surface image captured during the next image sampling cycle is maintained within a predetermined range.

Lighting control method of optical pointing device

Disclosed are a power on reset circuit, a power on reset method and an electric device using the same. In the power on reset circuit and method, a first voltage detecting circuit and a second voltage detecting circuit detect the voltage of a power supply and output a first voltage signal and a second voltage signal respectively. A logic circuit receives the first voltage signal and the second voltage signal to turn no or off the first voltage detecting circuit for detecting the voltage of the power supply. Specifically, merely when the voltage value of the power supply is less than a rising threshold voltage value of the first voltage detecting circuit or a falling threshold voltage value of the second voltage detecting circuit, the first voltage detecting circuit is turned on to detect the voltage value of the power supply.

Power on reset circuit, power on reset method and electric device using the same

The present invention discloses a voltage conversion apparatus and a power-ON reset (POR) circuit and a control method thereof. The voltage conversion apparatus includes: a conversion circuit, an input status detection circuit, an output status detection circuit, a status feedback circuit, and a POR circuit. The POR circuit generates a POR signal according to an input status signal, an output status signal, and a feedback signal, to indicate whether a POR procedure is completed. The POR circuit includes: a logic circuit, for generating a reset signal indicating whether both the input and output voltages are ready; and a delay circuit, for generating the POR signal by delaying a predetermined time period according to the reset signal and a feedback signal related to the POR signal.

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Penang, Malaysia

Poh-Weng Yem