Samsung Electro-mechanics Co., Ltd.

Hyoung Jun Jeon

Byoung Own Min

Hyun Jin Kim

Byung Woo Kang

Dong Kyun Lee

Jung Ho Ryu

Gui Youn Lee

The present invention provides a piezoelectric ultrasonic motor driver which can perform self-oscillation, adjust the rotational direction of the motor, and be easy to manufacture. The motor includes a metal body having a desired shape; a plurality of piezoelectric plates attached to surfaces of the metal body, contracted and expanded to rotate the metal body; a self-oscillation unit for oscillating at an electromechanical frequency of the piezoelectric plates an electrical signal; and a delay unit for delaying an oscillation signal of the self-oscillation unit in phase by 90 or &#x2212;90 degrees according to a desired rotational direction.

Piezoelectric ultrasonic motor driver

A variable square-wave drive device for controlling square waves using feedback- and bias-control methods. The variable square-wave drive device includes an oscillator for generating a clock pulse; a frequency-divider/duty controller for frequency-dividing the clock pulse received from the oscillator to generate a clock signal and a square-wave signal; a drive for amplifying the square-wave signal received from the frequency-divider/duty controller according to a bias voltage, generating first and second square-wave signals having opposite phases, and outputting the first and second square-wave signals as a square-wave drive signal; a feedback controller for comparing a predetermined voltage variable determined by a user with the bias voltage of the drive to generate a comparison result signal; a switching controller for generating a switching signal upon receiving the comparison result signal from the feedback controller; and a bias voltage regulator for charging/discharging the input voltage according to the switching signal received from the switching controller so that it can adjust the bias voltage of the drive.

Variable square-wave drive device

Disclosed herein is a piezoelectric actuator drive system for forward or backward driving a piezoelectric actuator for zooming and/or focusing in a camera module. The piezoelectric actuator drive system comprises a power supply for supplying an operating voltage, a drive controller for controlling generation of a forward/backward drive signal for a piezoelectric actuator in response to an operation ON select signal and a forward/backward driving select signal, a clock generator for generating a first clock signal in response to the operating voltage from the power supply, and a drive signal generator for generating and supplying the forward or backward drive signal to the piezoelectric actuator in response to the first clock signal from the clock generator and the operating voltage from the power supply under the forward/backward drive signal generation control of the drive controller.

Piezoelectric actuator drive system

Disclosed herein are a single-stage backlight inverter and a method for driving the same. The single-stage backlight inverter comprises a main oscillator for generating a predetermined triangle-wave oscillation signal, a predetermined clock signal and an inverted clock signal, and an output drive controller responsive to the triangle-wave oscillation signal, clock signal and inverted clock signal from the main oscillator and first and second reference voltages set therein. The second reference voltage has a level set to an intermediate level of the triangle-wave oscillation signal. The output drive controller is adapted to generate a first drive control signal and generate a second drive control signal. The inverter further comprises a first output unit for outputting a pair of first switching signals in response to the first drive control signal, and a second output unit for outputting a pair of second switching signals in response to the second drive control signal.

Single-stage backlight inverter and method for driving the same

A backlight inverter for an LCD panel of an asynchronous pulse width modulation (PWM) driving type which is capable of driving a plurality of cold cathode fluorescent lamps (CCFLs) in pairs and controlling a plurality of PWM drive signals for respective operations of the lamps to make the phases thereof different. The backlight inverter comprises a main driving integrated circuit (IC), at least one sub-driving IC, and a plurality of lamp operating circuits for operating the pairs of lamps in response to the first and second PWM drive signals and the third and fourth PWM drive signals, respectively. The lamps have different PWM on/off periods so that overshoot of a power supply circuit can be reduced so as to keep the entire system power stable.

Growing community of inventors

Kyungki-do, South Korea

Hyoung Jun Jeon