Lite-on Technology Corporation

Silitek Corporation Corporation

Ching-Chung Chang

Ho-Min Chung

A warm-up circuit adjusts the brightness of a CCFL through using PWM technique for a scanner. The warm-up circuit has an inverter connected to the CCFL for supplying power, and a PWM controller connected to the inverter for outputting a first control signal to the inverter in a warm-up time and outputting a second control signal to the inverter to control the inverter supplying power to the CCFL in a scan time.

Warm-up circuit for CCFLs

A driving device is provided for a cathode fluorescent lamp (CCFL) circuit, comprising a voltage generator outputting a driving voltage and a controller coupled thereto. The controller directs the voltage generator to output a first voltage exceeding a working voltage of the CCFL to initialize the CCFL. When brightness of the cold cathode lamp tube exceeds a working brightness of the CCFL, the controller directs the voltage generator to decrease the driving voltage gradually so that the brightness of the CCFL equals the working brightness. The controller stops decreasing the driving voltage when the driving voltage equals the working voltage.

Method and apparatus for a CCFL driving device

A driving device for a CCFL circuit comprising at least one CCFL is provided. The driving device comprising at least one heating device controlling the temperature of the at least one CCFL, a power supply outputting a first voltage, and a switching device having a first input terminal receiving the first voltage and a first and second output terminal; wherein the first output terminal is coupled to the CCFL circuit outputting a second voltage when the first voltage is higher than a first level, and the second output terminal is coupled to the at least one heating device outputting a third voltage when the first voltage is lower than the first level. The driving device further comprises a controller controlling the power supply to output the first voltage higher than the first level to lighting up the at least one CCFL, and lower than the first level to control the temperature of the at least one CCFL.

Method and device for driving CCFL circuit

A rapid warmup light actuator is disclosed to solve the problems that the light actuator cannot rapidly warm up the lighting load in the prior art and that unstable light sources result from the rapid temperature drop if the light is instantaneously disconnected and restarted. The device consists of an energy storage circuit, an oscillatory circuit, and a transformer. In the beginning of power supply, the energy storage circuit is charged. When starting the lighting load, the energy stored in the energy storage circuit rapidly warms up the lighting load in order to illuminate stable light. Using the energy stored in the energy storage circuit, the lighting load can continue its stable status even it is instantaneously disconnected and restarted.

Rapid warmup light actuator

A piezoelectric ceramic light starter, which includes a power switch, a piezoelectric transformer, and a frequency tracking unit, is disclosed. The power switch connected to a pulse width modulated (PWM) harmonic signal output terminal closes when the PWM harmonic signal is in its positive period, and opens when which signal is in negative period. The piezoelectric transformer has the input terminal of its first-level coil connected to the power switch. The output terminal of the first-level coil generates a high-frequency AC signal to drive a cold cathode fluorescent light (CCFL). The frequency tracking unit is coupled to the output terminal of the CCFL. When the light starter starts, a first frequency is obtained when the CCFL is lighted and a second frequency is obtained when the CCFL is turned off. The PWM harmonic signal uses the average of the first frequency and the second frequency as the basis for output.

Piezoelectric ceramic light starter

A method for activating an illuminator and an illuminating device. The invention uses pins on an application specific integrated circuit (ASIC) in a scanner to output pulses of different frequencies. The illuminator has different efficiencies at different frequencies, so the heat generated by the illuminator at the frequencies of inferior efficiency is used to achieve fast warm-up, and the voltage output frequency of the highest light efficiency is provided to the illuminator after warm-up. The illumination device can be designed according to the activation method. It comprises an illuminator, a pulse output unit, a driving unit and a power supply unit. The power supply unit outputs the frequency needed for the warm-up period and the frequency needed for the working period. The driving unit activates the pulse output of the pulse output unit.

Method for activating illuminator and illumination device

A securing device for a scanner is provided which comprises a scanner main body and a relay mechanism. The scanner main body houses an image scanning mechanism driven by a motor unit which is connected to a driving circuit. The relay mechanism is connected between the driving circuit and an external DC power source for supplying electrical power to the image scanning mechanism. The relay mechanism includes an electromagnetic coil and two switches. The electromagnetic coil is connected to the DC power source fed through an insertion hole formed on the scanner main body. The two switches are electrically connected to the driving circuit. The securing device automatically locks the image scanning mechanism when the DC power source does not send electrical power to the relay mechanism. The securing device is operated automatically to secure or unlock the image scanning mechanism of the scanner. Therefore, the securing device for a scanner overcomes such problems as those due to position deviation and motor idling.

Growing community of inventors

Taipei, Taiwan

Ching-Chung Chang