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Researchers Submit Patent Application, "Led Device, Led Driving Circuit and Method", for Approval

March 5, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors YANG, Hsing-Chien (Hsinchu County, TW); Cheng, Wen-Hsin (Hsinchu City, TW); Hsu, Ying-Hao (Hsinchu City, TW); Hsu, Lan-Ting (Hsinchu City, TW); Chang, Tsung-Hau (Hsinchu City, TW), filed on October 21, 2013, was made available online on February 20, 2014.

The patent's assignee is Novatek Microelectronics Corp.

News editors obtained the following quote from the background information supplied by the inventors: "The invention relates to a light-emitting diode (LED) device and an LED driving circuit and method.

"At present, an LED tends to serve as a backlight module of a flat display panel. However, two polar plates of a capacitor of the LED driver tend to deform when the voltage and the current of the LED driver in the backlight module are always changing, and an inductor of the LED driver also generates the retractable deformation. The capacitor and the inductor generate audible noise in the deformation process."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "The invention is directed to an LED device, an LED driving circuit and an LED driving method, in which an LED driving signal is shifted toward a higher frequency direction so that the frequency of the LED driving signal after frequency shifting exceeds the human auditory sensitivity.

"According to a first aspect, an LED driving circuit including an LED control circuit and a power stage circuit is provided. The LED control circuit shifts an input pulse width modulation (PWM) signal toward a higher frequency direction in a frequency domain to generate an output PWM signal having a duty cycle substantially the same as a duty cycle of the input PWM signal. The power stage circuit outputs an LED driving current according to the output PWM signal.

"According to a second aspect, an LED device is provided. The LED device includes one to multiple strings of LEDs and the LED driving circuit. The LED driving circuit is coupled to the one to multiple strings of LEDs and drives the one to multiple strings of LEDs.

"According to a third aspect, an LED driving method is provided. The method includes the following steps. First, an LED control circuit is utilized to shift an input PWM signal toward a higher frequency direction in a frequency domain to generate an output PWM signal having a duty cycle substantially the same as a duty cycle of the input PWM signal. Next, a power stage circuit is utilized to output an LED driving current according to the output PWM signal.

"The above and other aspects of the invention will become better understood with regard to the following detailed description of the preferred but non-limiting embodiment(s). The following description is made with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

"FIG. 1A is a schematic illustration showing an LED device according to an embodiment.

"FIG. 1B is a block diagram showing an LED driving circuit according to an embodiment.

"FIG. 2 is a block diagram showing an LED control circuit according to an embodiment.

"FIG. 3A is a schematic illustration showing an example of a duty cycle detecting circuit according to an embodiment.

"FIG. 3B shows waveforms in an example of the duty cycle detecting circuit according to an embodiment.

"FIG. 4 is a schematic illustration showing another example of the duty cycle detecting circuit according to an embodiment."

For additional information on this patent application, see: YANG, Hsing-Chien; Cheng, Wen-Hsin; Hsu, Ying-Hao; Hsu, Lan-Ting; Chang, Tsung-Hau. Led Device, Led Driving Circuit and Method. Filed October 21, 2013 and posted February 20, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=4695&p=94&f=G&l=50&d=PG01&S1=20140213.PD.&OS=PD/20140213&RS=PD/20140213

Keywords for this news article include: Novatek Microelectronics Corp.

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Source: Electronics Newsweekly


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