News Column

"Liquid Crystal Display Device Having Improved Cooling Efficiency" in Patent Application Approval Process

September 3, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- A patent application by the inventors Sung Ki, KIM (Yongin-si, KR); Won-nyun, KIM (Gwacheon-si, KR), filed on April 15, 2014, was made available online on August 21, 2014, according to news reporting originating from Washington, D.C., by VerticalNews correspondents.

This patent application is assigned to Samsung Electronics Co., Ltd.

The following quote was obtained by the news editors from the background information supplied by the inventors: "The present general inventive concept relates to a liquid crystal display, and more particularly, to a liquid crystal display having a light emitting diode (LED) as a light source.

"Recently, flat panel displays, such as a liquid crystal display (LCD), a plasma display panel (PDP), or an organic light emitting diode (OLED), have been widely developed to replace a conventional cathode ray tube (CRT).

"The LCD comprises a liquid crystal display panel, which has a thin film transistor substrate, a color filter substrate, and liquid crystal interposed between the thin film transistor substrate and the color filter substrate. Since the LCD is a non-light emitting apparatus, the LCD needs a backlight unit, which is disposed on a rear surface of the thin film transistor substrate, to supply light to the liquid crystal display panel. The amount of transmission of the light emitted from the backlight unit is controlled according to an array state of the liquid crystal. The LCD panel and the backlight unit are accommodated in a chassis.

"The backlight unit can be classified as one of an edge type backlight and a direct type backlight according to a position of a light source. The edge type backlight has a structure in which the light source is disposed on a lateral part of a light guide plate. The edge type backlight is applied to a relatively small liquid crystal display, which is generally used in laptop and desktop computers. The edge type backlight is advantageous for having high uniformity of luminance, long lifetime, and thin thickness.

"A light emitting diode (LED) has been widely used as the light source of the backlight unit due to its high brightness and excellent color realization. However, the LED generates much heat compared to other light sources, such as a cold cathode fluorescent lamp (CCFL) or an external electrode fluorescent lamp (EEFL). The heat from the LED may lower brightness and cause color shifts if it is not properly discharged.

"Conventional backlight units use a radiating fin, a heat pipe, and a cooling fan to remove heat generated by the LED, thereby making the LCD heavier and thicker."

In addition to the background information obtained for this patent application, VerticalNews journalists also obtained the inventors' summary information for this patent application: "The present general inventive concept provides a liquid crystal display (LCD) that has a thin thickness and an excellent LED cooling efficiency.

"Additional aspects and/or advantages of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present general inventive concept.

"The foregoing and/or other aspects and utilities of the present general inventive concept can be achieved by providing a liquid crystal display device, comprising a liquid crystal display panel, a light guide plate disposed on a lower part of the liquid crystal display panel, an LED circuit substrate disposed along at least one side of the light guide plate to accommodate an LED on a front surface of the LED circuit substrate, and a heat transmission member having a first part that faces a lower surface of the light guide plate and a second part which extendedly bends from the first part and faces the LED circuit substrate.

"The heat transmission member can comprise a first sub-layer formed across the first part and the second part of the heat transmission member, and a second sub-layer provided on at least a part of an external surface of the first sub-layer.

"The first sub-layer can be made of aluminum.

"A heat transmission of the second sub-layer can be larger than a heat transmission of the first sub-layer.

"The second sub-layer can be made of graphite.

"At least a part of the second sub-layer can be provided in the second part of the heat transmission member.

"The heat transmission of the second sub-layer can be greater than or equal to about 400 W/m.sup.2.

"The LED circuit substrate can be made of metal.

"The liquid crystal display can further comprise a gap pad disposed between the LED circuit substrate and the heat transmission member.

"The liquid crystal display can further comprise a reflection plate disposed at a rear side of the light guide plate, the reflection plate comprising a first surface disposed on a lower part of the light guide plate, a second surface extendedly bent from the first surface and disposed between the light guide plate and the LED, and comprising an LED accommodating hole to accommodate the LED, and a third surface extended from the second surface parallel to the liquid crystal display panel to cover a part of the light guide plate.

"The liquid crystal display can further comprise a reflection cover to reflect light from the LED toward the light guide plate and to accommodate the LED circuit substrate.

"The liquid crystal display can further comprise a first gap pad disposed between the LED circuit substrate and the reflection cover, and a second gap pad disposed between the reflection cover and the heat transmission member.

"The foregoing and/or other aspects and utilities of the present general inventive concept can also be achieved by providing a liquid crystal display unit, comprising a liquid crystal display panel, a first plate located on a bottom surface of the liquid crystal display panel to guide light to the liquid crystal display panel, a second plate located on a bottom surface of the first plate to reflect light to the first plate, a light source substrate having at least one light source to provide the light to the liquid crystal display panel through the first plate, and a first member located on a bottom surface of the second plate and contacting the light source substrate to transfer heat away from the at least one light source.

"The second plate can comprise a first surface parallel to the bottom surface of the first plate, a second surface perpendicular to the first surface, and a third surface parallel to the first surface and separated from the first surface by the second surface. The light source substrate can be located on the second surface of the second plate. The third surface of the second plate can prevent light from the at least one light source from reaching the liquid crystal display panel without passing through the first plate. The second surface of the second plate can include at least one hole to accommodate the at least one light source of the light source substrate. The first member can comprise a first surface parallel to the bottom surface of the first plate, and a second surface perpendicular to the first surface and contacting the light source substrate. The first member can further comprise at least one additional surface perpendicular to the first surface. The liquid crystal display unit can further comprise a second member located on a surface of the first member and contacting the first member to transfer heat away from the at least one light source and the first member. The second member can comprise at least one of a first surface parallel to the bottom surface of the first plate, and a second surface perpendicular to the first surface and contacting the second surface of the first member.

"The liquid crystal display panel can comprise a thin film transistor substrate, a color filter substrate, a sealant connecting the thin film transistor substrate and the color filter substrate, a closed space having a boundary defined by the thin film transistor substrate, the color filter substrate, and the sealant, and a liquid crystal layer located in the closed space. The first member can indirectly contact the light source substrate. The first member can indirectly contact the light source substrate through a plurality of intervening parts. The plurality of intervening parts can comprise a reflection part to reflect the light from the at least one light source to the first plate, and a heat transfer part to transfer the heat from the at least one light source to the first member.

"The light source substrate can contact the first plate. The at least one light source can be located on a first surface of the light source substrate, and the first member can contact a second surface of the light source substrate. A heat transmission of the second member can be greater than a heat transmission of the first member. The heat transmission of the first member can be in a range of about 150 W/m.sup.2 to about 400 W/m.sup.2, and the heat transmission of the second member can be greater than or equal to about 400 W/m.sup.2.

"The foregoing and/or other aspects and utilities of the present general inventive concept can also be achieved by providing a display device, comprising a panel, a guide unit disposed at a rear side of the panel to guide light to the panel, a light source disposed on an outer portion of the guide unit to emit the light to the guide unit, and a heat transfer member to create a heat transfer path to transfer heat from the light source to outside of the display device at a rear side thereof.

"The heat transfer member can operate without a cooling fan. The heat transfer member can have a surface area that is greater than or equal to a surface area of the panel. The heat transfer member can be parallel to the panel and can be exposed at a rear portion of the display device. The light source can be disposed at an edge of the guide unit. The heat member can form the heat transfer path to transfer heat in a first direction from the light source to a side portion of the display device and in a second directed from the side portion of the display device toward a rear portion of the device.

"The foregoing and/or other aspects and utilities of the present general inventive concept can also be achieved by providing a display panel casing, comprising a cover, a guide unit disposed at a rear portion of the cover, a light source disposed at an edge portion of the guide unit, and a heat transmission member comprising a rear panel of the casing and forming a path to transfer heat from the light source to the rear panel. The heat transfer member can comprise a first portion that is the rear panel of the casing, and a second portion extending perpendicular to the first portion and extending between the cover and the guide unit to closely contact the light source.

"The foregoing and/or other aspects and utilities of the present general inventive concept can also be achieved by providing a method of cooling a liquid crystal display apparatus, comprising transferring heat generated by a light source to a heat transfer member having a heat transmission of greater than or equal to 150 W/m.sup.2, and transferring the heat from the heat transfer member to outside of the liquid crystal display apparatus. The method can further comprise transferring the heat from the heat transfer member to a secondary heat transfer member, and transferring the heat from the secondary heat transfer member to outside of the liquid crystal display apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

"The above and/or other aspects and advantages of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompany drawings of which:

"FIG. 1 is an exploded perspective view illustrating a liquid crystal display (LCD) device according to an embodiment of the present general inventive concept;

"FIG. 2 illustrates a sectional view of the LCD device of FIG. 1;

"FIG. 3 illustrates a cooling flow of the LCD device of FIG. 1;

"FIG. 4 is a sectional view illustrating main parts of a liquid crystal display (LCD) device according to another embodiment of the present general inventive concept; and

"FIG. 5 is a sectional view illustrating main parts of a liquid crystal display (LCD) device according to still another embodiment of the present general inventive concept."

URL and more information on this patent application, see: Sung Ki, KIM; Won-nyun, KIM. Liquid Crystal Display Device Having Improved Cooling Efficiency. Filed April 15, 2014 and posted August 21, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=4008&p=81&f=G&l=50&d=PG01&S1=20140814.PD.&OS=PD/20140814&RS=PD/20140814

Keywords for this news article include: Light-emitting Diode, Samsung Electronics Co. Ltd.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


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Source: Electronics Newsweekly


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