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Patent Issued for Multiple Mode Driving Circuit and Display Device Including the Same

February 19, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- From Alexandria, Virginia, VerticalNews journalists report that a patent by the inventors Bae, Jong-Kon (Seoul, KR); Park, Hae-Woon (Seoul, KR); Jang, Min-Hwa (Yongin-si, KR); Cho, Han-Min (Seoul, KR); Moon, Young-Bae (Suwon-si, KR), filed on December 17, 2009, was published online on February 4, 2014.

The patent's assignee for patent number 8643638 is Samsung Electronics Co., Ltd. (Gyeonggi-Do, KR).

News editors obtained the following quote from the background information supplied by the inventors: "Example embodiments relate to a display device, for example, to a driving circuit of the display device.

"Recently, liquid crystal display (LCD) devices have been widely used because LCD devices are thinner and lighter-weight than cathode ray tube (CRT) display devices and because the quality of LCD devices is generally better than that of CRT display devices.

"An active-matrix LCD device includes a plurality of active elements respectively connected to a plurality of pixel electrodes arranged in a matrix. The contrast ratio of the active-matrix LCD device is higher than the contrast ratio of the simple-matrix LCD device. Therefore, most color LCD devices adopt an active-matrix type. Thin film transistor (TFT) is widely used as the active element connected to the pixel electrode of the active-matrix LCD device.

"A driving circuit which drives a liquid crystal panel of the LCD device may be constituted to operate in a cascade mode or in a dual gate mode. In the cascade mode, a source driving circuit includes at least two source driving integrated circuits (ICs) that are arranged in the upper side or in the lower side of the liquid crystal panel, and a gate driving circuit includes one gate driving IC that is arranged in the left side or in the right side of the liquid crystal panel. In the dual gate mode, a gate driving circuit includes at least two gate driving ICs that are arranged in the left side or in the right side of the liquid crystal panel, and a source driving circuit includes one source driving IC that is arranged in the upper side or in the lower side of the liquid crystal panel. A conventional LCD device requires a data register having a distinct structure depending on the cascade mode or the dual gate mode, respectively, for generating source driving signals corresponding to the same number of channels. For example, in the dual gate mode, the conventional source driving circuit drives source driving signals twice during one horizontal scanning period using a multiplexer for generating the same number of the source driving signals as the number of the source driving signals generated in the cascade mode including two source driving ICs. Therefore, for operating the conventional LCD device in the dual gate mode, the size of a layout on a chip for a multiplexer and a routing circuit increases. Therefore, the chip size of the driving circuit of the conventional LCD device also increases."

As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventors' summary information for this patent: "Example embodiments are directed to provide a driving circuit including a source driving IC capable of operating both in the cascade mode and in the dual gate mode.

"Example embodiments are directed to provide a display device including the driving circuit.

"According to example embodiments, a display device includes a driving circuit and a panel. The driving circuit is configured to generate a source output enable signal having at least one pulse during one horizontal scanning period in response to a mode signal and configured to generate a source driving signal by latching an image data in response to the source output enable signal. The driving circuit is further configured to generate an internal horizontal synchronization signal in response to the source output enable signal and configured to generate a gate driving signal in response to the internal horizontal synchronization signal. The panel is configured to display the image data in response to the gate driving signal and the source driving signal.

"In example embodiments, the driving circuit is configured to drive the panel in one of a cascade mode and a dual gate mode based on the mode signal.

"In example embodiments, the driving circuit further includes a plurality of source driving circuits, where one of the plurality of source driving circuits is configured to operate as a master and a remainder of the plurality of source driving circuits are configured to operate as a slave when the display device operates in the cascade mode.

"In example embodiments, the driving circuit is configured to generate at least two gate driving signals during the one horizontal scanning period when the display device operates in the dual gate mode.

"In example embodiments, the driving circuit is configured to generate the source output enable signal to have two or more pulses during the one horizontal scanning period when the display device operates in the dual gate mode.

"In example embodiments, the driving circuit further includes a control circuit, a source driving circuit, and a gate driving circuit. The control circuit is configured to generate a first image data by processing the image data, configured to generate the source output enable signal to have at least one pulse during one horizontal scanning period in response to the mode signal, and configured to generate the internal horizontal synchronization signal in response to the source output enable signal. The source driving circuit is configured to generate the source driving signal based on a grayscale voltage, the first image data and the source output enable signal. The gate driving circuit is configured to generate the gate driving signal based on the internal horizontal synchronization signal.

"In example embodiments, the control circuit is disposed in the source driving circuit.

"In example embodiments, the source driving circuit includes a shift register, a data register, and a data latch circuit. The shift register is configured to generate a sampling signal by shifting a source sampling clock signal. The data register is configured to generate the first image data in synchronization with a first clock signal. The data latch circuit is configured to sample and latch the first image data in response to the sampling signal and configured to output the first image data when the source output enable signal is activated.

"In example embodiments, the source driving circuit further includes a digital-to-analogy converter and an output buffer. The digital-to-analog converter is configured to generate an analog signal corresponding to the first image data received from the data latch circuit using the grayscale voltage. The output buffer is configured to generate the source driving signal by buffering the analog signal.

"In example embodiments, the driving circuit further includes a grayscale voltage generating circuit configured to generate the grayscale voltages related to a brightness of the panel.

"According to example embodiments, a driving circuit of a display device includes a control circuit, one or more source driving circuits, and a gate driving circuit. The control circuit is configured to generate a first image data by processing an input image data, configured to generate a source output enable signal having at least one pulse during one horizontal scanning period in response to a mode signal, and configured to generate an internal horizontal synchronization signal in response to the source output enable signal. The one or more source driving circuits are configured to generate a source driving signal based on a grayscale voltage, the first image data and the source output enable signal. The gate driving circuit is configured to generate a gate driving signal based on the internal horizontal synchronization signal."

For additional information on this patent, see: Bae, Jong-Kon; Park, Hae-Woon; Jang, Min-Hwa; Cho, Han-Min; Moon, Young-Bae. Multiple Mode Driving Circuit and Display Device Including the Same. U.S. Patent Number 8643638, filed December 17, 2009, and published online on February 4, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=60&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=2977&f=G&l=50&co1=AND&d=PTXT&s1=20140204.PD.&OS=ISD/20140204&RS=ISD/20140204

Keywords for this news article include: Samsung Electronics Co. Ltd.

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Source: Electronics Newsweekly


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