KR20060083616A - Back light assembly, method for driving the same and display device having the same - Google Patents

Abstract

Disclosed are a backlight assembly, a driving method thereof, and a display device having the same, wherein the display quality of an image is improved by heat radiation. The backlight assembly includes a light generating unit, a container, a photovoltaic unit, and a heat radiating fan. The light generating unit generates light. The storage container includes a bottom surface and a side wall extending from an edge of the bottom surface to receive the light generating unit. The photovoltaic unit is arranged on the sidewall and generates electricity using some of the light. The heat dissipation fan is disposed on the side wall, and receives electricity from the photovoltaic unit to release heat in the storage container. As described above, by driving the heat radiating fan through self-generation by the light generated by the light generating unit, heat in the storage container can be effectively discharged to the outside to improve the display quality of the image.

Description

BACK LIGHT ASSEMBLY, METHOD FOR DRIVING THE SAME AND DISPLAY DEVICE HAVING THE SAME}

1 is an exploded perspective view illustrating a backlight assembly according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the backlight assembly of FIG. 1 taken along line II ′. FIG.

3 is a block diagram illustrating a driving device of a heat radiating fan in the backlight assembly of FIG. 1.

4 is a flowchart illustrating a method of driving a backlight assembly according to an embodiment of the present invention.

5 is a perspective view illustrating a display device according to an exemplary embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: light generating unit 200: storage container

210: bottom surface 220: side wall

300: photovoltaic unit 350: charging unit

400: heat dissipation fan 500: fan drive unit

600: reflecting plate 650: light diffusing member

700: display panel 800: optical sheet                 

900: top chassis 950: fixed member

The present invention relates to a backlight assembly, a method of driving the same, and a display device having the same. More particularly, the present invention relates to a backlight assembly, a method of driving the same, and a display device having the same by improving heat dissipation.

In general, various electronic devices such as mobile communication terminals, digital cameras, notebook computers, and monitors include a display device for displaying an image. There are various types of display devices, such as cathode-ray tubes, liquid crystal displays, plasma display panels, field emission displays and electroluminescence. There is an electroluminescence device.

Among these, the liquid crystal display (LCD) displays an image by using the electrical and optical characteristics of the liquid crystal (Liquid Crystal). The liquid crystal display (LCD) is thinner and lighter than other display devices, has advantages of low power consumption and low driving voltage, and is widely used throughout the industry.

The liquid crystal display (LCD) includes a liquid crystal display panel for displaying an image using a light transmittance of liquid crystal and a backlight assembly for providing light to the display panel.

The backlight assembly employed in the liquid crystal display includes a light source for generating light, and is classified into an edge type backlight assembly and a direct type backlight assembly according to the position of the light source.

As a light source of the backlight assembly, a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp (EEFL), a flat fluorescent lamp (FFL), and the like are used. Recently, a light emitting diode (LED) having low power consumption and excellent color reproducibility and brightness has been used as the light source.

However, not only light is generated from all light sources including the light emitting diodes (LEDs) but also heat is generated. The heat increases the temperature in the liquid crystal display (LCD), and the elevated temperature deteriorates the liquid crystal in the liquid crystal display (LCD), thereby degrading the display quality of the image of the liquid crystal display (LCD).

Accordingly, the technical problem of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a backlight assembly for improving display quality of an image by driving and radiating a heat radiating fan by its own photovoltaic power generation.

Another object of the present invention is to provide a method of driving the backlight assembly.

Still another object of the present invention is to provide a display device including the backlight assembly.

In order to achieve the above object of the present invention, the backlight assembly includes a light generating unit, a receiving container, a photovoltaic unit, and a heat radiating fan, and may further include a charging unit and a fan driving control unit. . The light generating unit generates light. Preferably, the light generating unit may be a light emitting diode that generates light having a point-shaped optical distribution. The storage container includes a bottom surface and a side wall extending from an edge of the bottom surface to accommodate the light generating unit. The photovoltaic unit is disposed on the sidewall and generates electricity using a portion of the light. The heat dissipation fan is disposed on the side wall, and receives the electricity from the photovoltaic unit to release heat in the storage container. The charging unit is stored in the storage container to store electricity generated by the photovoltaic unit. The fan drive control unit is accommodated in the storage container to control the driving of the heat radiating fan.

In order to achieve the above object of the present invention, a method of driving a backlight assembly according to an embodiment first measures a temperature in a storage container accommodating a light generating unit. Subsequently, the driving of the heat radiating fan is controlled by comparing the temperature with a reference value.

In accordance with another aspect of the present invention, a display device includes a backlight assembly and a display panel. The backlight assembly may include a light generating unit for generating light, a storage container for accommodating the light generating unit including a bottom surface and a sidewall, a photovoltaic unit disposed on the sidewall and generating electricity using a portion of the light; And a heat dissipation fan disposed on the sidewall and receiving the electricity from the photovoltaic unit to release heat of the storage container. The display panel is disposed on the backlight assembly to display an image using light generated by the backlight assembly.

According to such a backlight assembly and a display device having the same, by using a part of the light generated in the light generating unit to generate electricity, and by driving the heat radiating fan by the electricity, it is possible to emit more heat in the storage container to the outside, and The display quality of the resultant image can be further improved.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Example of Backlight Assembly>

1 is an exploded perspective view illustrating a backlight assembly according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view of the backlight assembly of FIG. 1 taken along line II ′.

1 and 2, the backlight assembly includes a light generating unit 100, a storage container 200, a photovoltaic unit 300, a heat radiating fan 400, a fan driving control unit 500, and a reflecting plate 600. And a light diffusing member 650.

The light generating unit 100 is disposed in the storage container 200 to generate light having a point-shaped optical distribution. The light generating unit 100 includes a driving substrate 110, a light emitting diode 120, and a diffusion lens 130.

The driving substrate 110 has a plate shape extending in the Y-axis direction, and a plurality of the driving substrates 110 are disposed in parallel in the X-axis direction. Alternatively, a plurality of the driving substrate 110 may be arranged in parallel in the Y-axis direction. Wires for supplying power to the light emitting diodes 120 are formed on the driving substrate 110. The driving substrate 110 may include a metal material having excellent thermal conductivity. For example, the metal material may be aluminum (Al). In this case, the wiring is preferably protected with an insulating material such as synthetic resin to electrically insulate the metal material.

The plurality of light emitting diodes 120 is disposed on each of the driving substrates 110. The light emitting diode 120 receives power from the wiring of the driving substrate 110 to generate light having a point-shaped optical distribution.

The light emitting diode 120 includes a red light emitting diode for generating red light, a green light emitting diode for generating green light, and a blue light emitting diode for generating blue light. The red light, green light and blue light are mixed with each other to form white light. In this case, at least one of the red light emitting diode, the green light emitting diode, and the blue light emitting diode may be configured in plural. As another example, the light emitting diode 120 may include a white light emitting diode that generates white light.

A plurality of diffusion lenses 130 are disposed on each of the driving substrates 110 to surround each of the light emitting diodes 120. The diffusion lens 130 changes a path of light generated by each of the light emitting diodes 120. For example, the diffusion lens 130 changes the path of the light to be inclined with respect to the Z-axis direction, thereby increasing the mixing efficiency of the light.

The storage container 200 includes a storage space including the bottom surface 210 and a side wall 220 extending from an edge of the bottom surface 210. The light generating unit 100 is accommodated in the accommodation space. The side wall 220 of the storage container 200 has a '-' shape and includes a step 222 for supporting an edge of the light diffusing member 650.

The photovoltaic unit 300 is disposed on the sidewall 220, and generates electricity using a portion of the light generated by the light generating unit 100. The photovoltaic unit 300 includes a plurality of photo cells.

Each photovoltaic cell 310 generates photovoltaic power by a photoelectric effect. Types of the photovoltaic cell 310 include, for example, selenium (Se) photovoltaic cells and copper nitrous oxide (Cu 2 O) photovoltaic cells, which are made of a junction between a metal and a semiconductor, and silicon (Si) photovoltaic cells made of a pn junction of a semiconductor.

Although FIG. 1 illustrates that the photovoltaic unit 300 is disposed inside the sidewall 220, the photovoltaic unit 300 may be disposed outside the storage container 200. The photovoltaic unit 300 disposed outside generates electricity by external light. In addition, although not shown in FIG. 1, a charging unit that stores the electromotive force generated by the photovoltaic unit 300 may be further disposed in the storage container 200.

The heat radiating fan 400 is electrically connected to the photovoltaic unit 300 and is disposed on the sidewall 220. As the photovoltaic unit 300 supplies power to the heat dissipation fan 400, a propeller of the heat dissipation fan 400 is driven to discharge heat in the storage container 200 to the outside. At this time, in consideration of the photovoltaic power generated in the light generating unit 300 and the heat dissipation efficiency, etc., the power consumption of the heat dissipation fan 400 preferably has a range of 3W ~ 7W.

The fan drive control unit 500 is disposed in the storage container 200 to control the driving of the heat radiating fan 400. The fan drive control unit 500 is disposed between the photovoltaic unit 300 and the heat dissipation fan 400 to electrically connect the photovoltaic unit 300 to the heat dissipation fan 400. Or open. For example, the fan driving control unit 500 senses a temperature in the storage container and drives the heat radiating fan 400 only when the measured temperature has a value equal to or greater than a reference value.

The reflection plate 500 is disposed on the bottom surface 210 of the storage container 200 to reflect the light toward the bottom surface 210 of the light generated by the light generating unit 300 upward. A plurality of holes 510 are formed in the reflective plate 500 at positions corresponding to the diffusion lenses 130 of the light generating unit 200.

The light diffusing member 600 is disposed above the light generating unit 200, and diffuses the light generated in the light generating unit 200 to improve light mixing efficiency.

As described above, the photovoltaic unit 300 generates electricity by using a portion of the light generated by the light generating unit 100 disposed inside the storage container to drive the heat radiating fan 400. The heat in the storage container 200 can be effectively released to the outside.

In FIG. 1, the light generating unit 100 illustrates the light emitting diode for generating light having a point-shaped optical distribution. In another example, the light generating unit 100 has a tubular lamp having a rod shape or a U shape. Can be. The tubular lamp includes a Cold Cathode Fluorescent Lamp (CCFL) and an External Electrode Fluorescent Lamp (EEFL). As another example, the light generating unit 100 includes a flat fluorescent lamp (FFL) having an optical distribution in the form of a plane.

In FIG. 1, the photovoltaic unit 300 and the heat dissipation fan 400 are disposed on one side wall 220, but as another example, the photovoltaic unit 300 and the heat dissipation fan 400 are provided. It may be disposed on two or more of the side walls 220. In addition, in view of the fact that the backlight assembly is disposed upright in the X-axis direction, the heat dissipation fan 400 has the sidewalls corresponding to the upper surface in the X-axis in order to effectively dissipate heat using the convection of air. Preferably disposed at 220).

3 is a block diagram illustrating a driving device of a heat radiating fan in the backlight assembly of FIG. 1.

Referring to FIG. 3, the driving device of the heat radiating fan includes a photovoltaic unit 300, a charging unit 350, a fan driving control unit 500, and a heat radiating fan 400.

The photovoltaic unit 300 generates electromotive force using a portion of the light generated by the light generating unit 100, and provides the generated electromotive force to the charging unit 350. The photovoltaic unit has a positive terminal (+) and a negative terminal (−).

The charging unit 350 stores the electromotive force provided by the photovoltaic unit 300. The charging unit 350 includes a positive terminal (+) and a negative terminal (−), and is electrically connected to the positive terminal (+) and the negative terminal (−) provided in the photovoltaic unit 300, respectively. Is connected.

The fan driving control unit 500 is disposed between the charging unit 350 and the heat dissipation fan 400 to electrically connect or close the charge unit 350 and the heat dissipation fan 400. (open) The fan drive control unit 500 includes a temperature sensor 510 and a fan drive switch 520.

The temperature sensor 510 measures the temperature in the storage container 200 and controls the fan driving switch 520 based on the measured temperature value. The temperature sensor 510 applies a close signal to the fan driving switch 520 when the measured temperature is greater than or equal to the reference value, and when the measured temperature is less than or equal to the reference value, the fan An open signal is applied to the driving switch 520.

The fan driving switch 520 provides the electromotive force stored in the charging unit 350 to the heat dissipation fan 500 in response to a signal provided from the temperature sensor 510. The fan driving switch 520 includes a pair of positive terminals (+) and a pair of negative terminals (−), and is provided in the charging unit 350 and the heat dissipation fan 400. It is electrically connected to the positive and negative terminals, respectively.

The fan driving switch 520 electrically connects the charging unit 350 and the heat dissipation fan 400 when the connection signal is applied from the temperature sensor 510. On the other hand, the fan driving switch 520 blocks the electrical connection between the charging unit 350 and the heat radiating fan 400 when the blocking signal is applied from the temperature sensor 510.                     

The heat radiating fan 400 is driven by receiving electromotive force from the charging unit 350 by the fan driving switch 520. When the heat dissipation fan 400 is electrically connected to the charging unit 350 by the fan driving switch 520 and driven, the heat dissipation fan 400 dissipates heat in the storage container 200 to the outside and the storage container 200. Decreases the temperature inside.

As such, when the temperature in the storage container 200 is checked and the checked temperature is higher than the reference value, the temperature of the storage container 200 is reduced by driving the heat radiating fan 400, while the checked temperature is reduced. Is lower than the value of the reference value, by stopping the driving of the heat radiating fan 400, it is possible to block the increase in noise or power consumption caused by the unnecessary operation of the heat radiating fan 400.

In FIG. 3, the driving device of the heat radiating fan includes the fan driving control unit 500 to control the start of the heat radiating fan based on the temperature in the storage container. However, the fan driving control unit 500 is described. May be omitted. In this case, the electromotive force stored in the charging unit 350 is provided to the heat dissipation fan 400 together with the start of the backlight assembly, and the electromotive force supplied to the heat dissipation fan 400 is cut off when the backlight assembly is stopped. By doing so, the driving of the heat radiating fan 400 can be easily controlled.

<Example of Driving Method of Backlight Assembly>

4 is a flowchart illustrating a method of driving a backlight assembly according to an embodiment of the present invention.                     

Referring to FIG. 4, in the method of driving a backlight assembly, first, a temperature T of the storage container 200 is measured (S110).

The light generating unit 100 accommodated in the storage container 200 not only generates light but also generates a large amount of heat. The heat raises the temperature T in the storage container 200, and the temperature T is measured by the temperature sensor 510 accommodated in the storage container 200. In this case, while the temperature T in the storage container 200 is measured by the temperature sensor 510, the photovoltaic unit 300 uses a part of the light generated by the light generating unit 100. Generates electricity, and the charging unit 350 charges electricity generated in the photovoltaic unit 300.

After measuring the temperature T in the storage space 200, the driving of the heat radiating fan 400 is controlled by comparing the temperature T with a reference value (S120 and S130).

When the temperature T has a low value compared with the value of the reference value, the temperature T in the storage container 200 is continuously measured. On the other hand, when the temperature (T) has a high value compared to the value of the reference value, by driving the heat radiating fan 400 to reduce the temperature (T) in the storage container (200). In this case, the reference value is preferably a value of a temperature low enough to prevent deterioration of the liquid crystal layer interposed in the liquid crystal display panel, for example, 35 ° C to 40 ° C.

For example, the temperature sensor 510 measures the temperature (T) and compares it with a value of a reference value, and the temperature sensor 510 is the charging unit 350 and the The fan drive switch 520 that electrically connects and disconnects the heat radiating fan 400 is turned on / off, and as a result, driving of the heat radiating fan 400 is controlled.

After driving the heat radiating fan 400 to reduce the temperature T in the storage container 200, the temperature T in the storage space is measured again (S140).

Subsequently, the driving of the heat radiating fan 400 is again controlled by comparing the measured temperature T again with a reference value (S150 and S160).

When the measured temperature T again has a high value compared with the reference value, the heat dissipation fan 400 is continuously driven to reduce the temperature T in the storage container 200. On the other hand, when the temperature (T) has a low value compared to the value of the reference value, the driving of the heat radiating fan 400 is stopped. At this time, regardless of the driving of the heat radiating fan 400, the electricity generated in the photovoltaic unit 300 is continuously charged by the charging unit 350.

Finally, it is checked whether the power applied to the backlight assembly is cut off (S170).

When the power applied to the backlight assembly is cut off, the driving of the heat radiating fan 400 is completely stopped. On the other hand, if power is continuously applied to the backlight assembly, the temperature in the storage container 200 is continuously measured to continuously control the driving of the heat radiating fan 400.

As such, when the temperature in the storage container 200 is checked and the checked temperature is higher than the reference value, the temperature of the storage container 200 is reduced by driving the heat radiating fan 400, while the checked temperature is reduced. Is lower than the value of the reference value by stopping the driving of the heat radiating fan 400, it is possible to block the noise generated as the heat radiating fan 400 is unnecessarily operated. In addition, when the heat radiating fan 400 is not driven, the charging unit 350 stores electricity generated in the photovoltaic unit 300, thereby efficiently utilizing the electromotive force stored in the charging unit 350. have.

<Example of Display Device>

5 is a perspective view illustrating a display device according to an exemplary embodiment of the present invention. Since the backlight assembly of the display device according to the exemplary embodiment has the same configuration as the backlight assembly according to the above-described embodiment, duplicate description thereof will be omitted, and the same reference numerals and names are used for the same components. I will use it.

Referring to FIG. 5, the display device includes a backlight assembly generating light and a display panel 700 displaying an image using light.

The display panel 700 is disposed above the backlight assembly and changes the light generated by the backlight assembly into image light including information. The display panel 700 includes a first substrate 710, a second substrate 720, and a liquid crystal layer 730.

The first substrate 710 includes a plurality of pixel electrodes arranged in a matrix, thin film transistors (TFTs) for applying a driving voltage to the pixel electrodes, and the thin film transistors. Signal lines for operating the respective TFTs.

The pixel electrode includes a transparent and conductive indium tin oxide film (ITO), an indium zinc oxide film (IZO), and an amorphous indium tin oxide film (a-ITO). ) And the like are patterned and formed by a photo-etching process.

The second substrate 720 is disposed to face the first substrate 710. The second substrate 720 includes a common electrode which is disposed on the front surface of the second substrate 720 and is transparent and conductive, and color filters disposed to face the pixel electrodes. .

The color filters include a red color filter selectively passing red light of white light, a green color filter selectively passing green light of white light, and blue color filters selectively passing blue light of white light.

The liquid crystal layer 730 is interposed between the first substrate 710 and the second substrate 720 and is rearranged by an electric field formed between the pixel electrode and the common electrode. The rearranged liquid crystal layer 730 adjusts the light transmittance of the light generated by the backlight assembly, and the light whose light transmittance is adjusted passes through the color filters to display an image.

The display panel 700 may further include a printed circuit board 740 and a flexible printed circuit board 750.

The printed circuit board 740 includes a driving circuit unit for processing an image signal, and the driving circuit unit converts an image signal input from the outside into a driving signal for controlling the thin film transistor TFT.

The flexible printed circuit board 750 electrically connects the printed circuit board 740 and the first substrate 710 to drive signals generated from the printed circuit board 740 to the first substrate 710. to provide.

The display device further includes an optical sheet 800, a top chassis 900, and a fixing member 950.

The optical sheet 800 is disposed between the backlight assembly and the display panel 700. The optical sheet 800 improves the optical characteristics of the light generated by the backlight assembly.

The optical sheet 800 may include, for example, a diffusion sheet 810 for diffusing light to improve uniformity of brightness and mixing efficiency of light, and at least one prism sheet for improving front brightness of light through reflection and refraction. 820. For example, the prism sheet 820 includes a first prism sheet having a first prism pattern formed in the X-axis direction and a second prism sheet having a second prism pattern formed in the Y-axis direction.

The top chassis 900 surrounds the edge of the display panel 700 and is coupled to the side wall 220 of the storage container 200 to fix the display panel 700 to an upper portion of the backlight assembly.

The top chassis 900 prevents the display panel 700 from being damaged or damaged by brittleness due to external shocks and vibrations, and the display panel 700 is separated from the storage container 200. Prevent it.

The fixing member 950 is disposed between the backlight assembly and the optical sheets 800 and supports edges of the display panel 700 and the optical sheets 800.

As described above, according to the present invention, the photovoltaic unit disposed on the side wall of the storage container generates electricity by using a part of the light generated in the light generating unit, and heats the fan in the storage container by driving the heat radiating fan. Can be effectively emitted to the outside, and as a result, the display quality of the image of the display device can be further improved.

In addition, by measuring the temperature in the storage container to drive the heat radiating fan only when a predetermined reference value or more, it is possible to more efficiently utilize the electricity charged in the charging unit.

Although described above with reference to the embodiments, those skilled in the art can be variously modified and changed within the scope of the present invention without departing from the spirit and scope of the invention described in the claims below. I can understand.

Claims (11)

A light generating unit for generating light; A storage container including a bottom surface and a side wall extending from an edge of the bottom surface, to accommodate the light generating unit; A photovoltaic unit disposed on the sidewall and generating electricity by using a portion of the light; And And a heat dissipation fan disposed on the sidewall and receiving the electricity from the photovoltaic unit to release heat in the storage container. The backlight assembly of claim 1, wherein the light generating unit is a light emitting diode for generating light having a point-shaped optical distribution. The backlight assembly of claim 1, wherein the light generating unit is a tubular lamp having a rod shape. The backlight assembly of claim 1, wherein the light generating unit is a surface light source for generating light having an optical distribution in the form of a plane. The backlight assembly of claim 1, wherein the heat dissipation fan has a power consumption in the range of 3W to 7W. The backlight assembly of claim 1, further comprising a charging unit accommodated in the storage container to charge electricity generated by the photovoltaic unit. The backlight assembly of claim 1, further comprising a fan driving control unit accommodated in the storage container to control driving of the heat radiating fan. The fan drive control unit of claim 1, wherein A temperature sensor for measuring a temperature in the storage container; And And a fan driving switch controlling the driving of the heat radiating fan by the temperature sensing sensor. Measuring a temperature in the housing containing the light generating unit; And Controlling the driving of the radiating fan by comparing the temperature with a reference value. The method of claim 9, wherein the heat radiating fan is driven by electricity generated by using a part of the light generated by the light generating unit. A light generating unit for generating light, a storage container for accommodating the light generating unit including a bottom surface and a sidewall, a photovoltaic unit disposed on the sidewall and generating electricity using a portion of the light, A backlight assembly having a heat dissipation fan disposed to receive the electricity from the photovoltaic unit and release heat of the storage container; And And a display panel disposed on the backlight assembly and configured to display an image by using light generated by the backlight assembly.

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