KR20070065079A - Led lamp unit, backlight assembly having the same and display deive having the same - Google Patents

Abstract

A LED(light emitting diode) lamp unit, a backlight assembly including the same, and a display device including the same are provided to improve an adhesive force between a lower structure and an LCD(Liquid Crystal Display) lamp unit by applying a white adhesive member on a flexible circuit board including an LED lamp. An LED lamp(710) is mounted on a flexible printed circuit board(720). A white adhesive member is provided on the flexible printed circuit board. The LED lamp is a white LED of a side emission type. The white adhesive member is a white both-sided tape, or a white opaque adhesive agent. The flexible circuit board includes a base film having flexibility, a metal line applied on the base film, and a protection film provided on the base film to protect the metal line. A portion of the protection film is cut for mounting of the LED lamp, and the white adhesive member is applied on the cut protection film.

Description

LED lamp unit, backlight assembly including the same and display device having same {LED LAMP UNIT, BACKLIGHT ASSEMBLY HAVING THE SAME AND DISPLAY DEIVE HAVING THE SAME}

1 is an exploded perspective view of a display device using a conventional LED lamp unit as a backlight assembly light source.

2 is a cross-sectional view of the LED lamp unit taken along line A-A.

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

4 is a cross-sectional view of the LED lamp unit of this embodiment taken along line B-B.

5 is a cross-sectional view of a display device according to the present embodiment.

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

100, 1000: display assembly 20, 2000: backlight assembly

50, 700: LED lamp unit 51, 710: LED lamp

55: white film 730: white adhesive member

The present invention relates to an LED lamp unit, a backlight assembly including the same, and a display device having the same, and more particularly, to include a LED lamp unit that can simplify the manufacturing method of the LED lamp unit of the backlight assembly having the LED lamp unit. It relates to a backlight assembly and a display device having the same.

In today's information society, the role of electronic display devices becomes more and more important, and various electronic display devices are widely used in various industrial fields.

In general, an electronic display device refers to a device that transmits various information to a human through vision. In other words, an electronic display device may be defined as an electronic device that converts electrical information signals output from various electronic devices into optical information signals that can be recognized by human eyes, and serves as a bridge that connects humans and electronic devices. It may be defined as.

In such an electronic display device, when an optical information signal is displayed by a light emitting phenomenon, it is called an emissive display device, and when a light modulation is displayed by reflection, scattering, or interference phenomenon, a light receiving display ( It is called a non-emissive display device. The light emitting display device, also called an active display device, includes a cathode ray tube (CRT), a plasma display panel (PDP), a light emitting diode (LED), and an electroluminescent display (electroluminescence display). luminescent display; ELD). In addition, the light receiving display device, which is a passive display device, includes a liquid crystal display (LCD), an electrochemical display (ECD), and an electro phoretic image display (EPID). .

Cathode ray tubes (CRTs) used in image display devices such as televisions and computer monitors occupy the highest share in terms of display quality and economy, but have many disadvantages such as heavy weight, large volume and high power consumption. .

However, due to the rapid progress of semiconductor technology, the electronic display device suitable for the new environment, that is, the thin and light, the low driving voltage and the low power consumption, according to the solidification, low voltage and low power of various electronic devices, and the small size and light weight of electronic devices The demand for flat panel display devices with features is rapidly increasing.

Among the various flat panel display devices currently developed, liquid crystal displays are thinner and lighter than other display devices, have low power consumption and low driving voltage, and are widely used in various electronic devices because they are capable of displaying images close to cathode ray tubes. Is being used.

However, the liquid crystal display device does not have a structure that emits light itself, and thus, unless light is irradiated from the outside, the image cannot be visualized. Therefore, a backlight assembly, which is a separate light source, is disposed under the liquid crystal display panel to display an image.

Conventionally, a cold cathode fluorescent lamp (CCFL) was used as a light source of a backlight assembly. However, nowadays, researches are being actively conducted to use LEDs having advantages of high lifespan, low power consumption, light weight, and thickness as a light source.

In particular, an LED lamp unit in which LEDs are mounted on a flexible printed circuit board is used as a light source of a backlight assembly for light weight and thinness.

1 is an exploded perspective view of a display device using a conventional LED lamp unit as a backlight assembly light source. 2 is a cross-sectional view of the LED lamp unit taken along line A-A.

1 and 2, a conventional display device includes a display assembly 100 displaying an image and a backlight assembly 200 irradiating light to the display assembly 100.

The display assembly 100 includes a liquid crystal display panel including a color filter substrate 10 and a thin firm transistor (TFT) substrate 20. The backlight assembly 200 includes a plurality of optical sheets 30, a lower accommodating member 40 including a light guide plate, and an LED lamp unit 50. When the display device is coupled, the LED lamp unit 50 is rotated 180 degrees in the direction of the arrow shown in FIG. 1 to be fixed to the lower accommodating member 40.

The LED lamp unit 50 includes the LED lamp 51, the flexible circuit boards 52, 53, and 54 on which the LED lamp 51 is mounted, and the flexible circuit board in the light emission direction of the LED lamp 51. A white film 55 coated on the 52, 53, and 54, and a transparent adhesive member 56 coated on the flexible circuit boards 52, 53, and 54 coated with the white film 55. do.

The LED lamp 51 uses an LED that emits white light, and uses an LED that emits side light. The flexible circuit boards 52, 53, and 54 may be provided on the base film 52, a plurality of metal wirings 53 patterned thereon, and a protection provided on the base film 52 including the metal wirings. Film 54. In this case, a part of the protective film 233 is provided with a cutout for mounting the LED lamp 51, and the metal wiring 53 for driving the LED lamp 51 is exposed inside the cutout. The LED lamp 51 is mounted on the exposed metal wiring 53.

However, as described above, since the LED lamp 51 mounted on the flexible circuit boards 52, 53, 54 emits side light, the white light emitted from the LED lamp 51 is not the flexible circuit boards 52, 53,. The light guide plate is irradiated horizontally with respect to the surface thereof. In this case, part of the white light is reflected by the flexible circuit boards 52, 53 and 54 and irradiated onto the light guide plate. In general, since the films of the flexible circuit boards 52, 53 and 54 are yellowish brown, the flexible printed circuit board The white light reflected by (52, 53, 54) is yellow in color instead of white. As a result, part of the light irradiated onto the light guide plate becomes yellow, causing problems such as deterioration of the backlight efficiency and deterioration of color reproduction of the display device.

Therefore, in the related art, the white film 55 is coated on the flexible circuit boards 52, 53, and 54 corresponding to the light emitting direction of the LED lamp 51, and thus the white light reflected by the flexible circuit boards 52, 53, and 54 is applied. The phenomenon that the color changes is prevented.

However, in the related art, the LED lamp 51 is mounted on the flexible circuit boards 52, 53, and 54, and the white film (the film is formed on the flexible circuit boards 52, 53, 54 corresponding to the light emitting direction of the LED lamp 51). 55), the curing process is complicated, and then the manufacturing process is complicated, such as the adhesive member 56 to be applied on the flexible circuit board (52, 53, 54) including the white film 55, thereby producing There is a problem of rising costs. In addition, in order to apply the white film only to a region corresponding to the light emitting direction of the LED lamp, there is a problem in that the precision of the white film printing process needs to be improved.

Accordingly, the present invention is derived to solve the above problems, LED lamp unit that can reduce the cost of components and manufacturing process by applying a white adhesive member on the flexible circuit board mounted LED lamp, including the same An object of the present invention is to provide a backlight assembly and a display device having the same.

Provided is an LED lamp unit comprising an LED lamp according to the present invention, a flexible printed circuit board on which the LED lamp is mounted, and a white adhesive member provided on the flexible circuit board.

At this time, the LED lamp is preferably a white LED emitting side.

In addition, the white adhesive member is preferably a white double-sided tape or a white opaque adhesive.

The above-described flexible circuit board preferably includes a flexible base film, a metal wiring applied on the base film, and a protective film provided on the base film to protect the metal wiring. Here, it is effective to partially cut the protective film for mounting the LED lamp, and to apply the white adhesive member on the cut protective film.

In addition, a flexible printed circuit board on which a white LED lamp according to the present invention is mounted, an LED lamp unit including a white adhesive member provided on the flexible circuit board, an accommodating member for accommodating the LED lamp unit, and the accommodating member It includes a backlight assembly provided on the inside and including a light guide plate disposed adjacent to the LED lamp unit.

Here, the accommodating member may include an LED lamp coupling unit connected to the LED lamp unit through the white adhesive member, and the LED lamp coupling unit may include a plurality of through holes through which the white LED lamp is inserted.

In addition, the flexible circuit board may effectively include a connection area connected to the LED lamp coupling part and an extension area extending outside the storage member. It is preferable that a white adhesive member is provided on the said connection area | region.

Of course, it is effective that the white adhesive member is a white double-sided tape or a white opaque adhesive.

In addition, a flexible printed circuit board on which a white LED lamp for generating light according to the present invention is mounted, an LED lamp unit including a white adhesive member provided on the flexible circuit board, and a housing member accommodating the LED lamp unit And a backlight assembly provided inside the accommodating member, the light guide plate disposed adjacent to the LED lamp unit, and a liquid crystal display panel displaying an image using light supplied from the backlight assembly.

Here, the white adhesive member is preferably a white double-sided tape or a white opaque adhesive.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention in more detail. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention, and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you.

In the drawings, the thickness of layers, films, panels, regions, etc., may be exaggerated for clarity, and like reference numerals designate like elements. In addition, when a part such as a layer, a film, an area, or a plate is expressed as being on or above another part, not only when each part is directly above or directly above the other part but also another part between each part and another part This includes cases.

3 is an exploded perspective view of a display device according to an exemplary embodiment.

4 is a cross-sectional view taken along line B-B of the LED lamp unit according to the present embodiment, and FIG. 5 is a cross-sectional view of the display device according to the present embodiment.

3 to 5, the liquid crystal display according to the present exemplary embodiment includes a display assembly 1000 disposed above and a backlight assembly 2000 disposed below.

The display assembly 1000 includes a liquid crystal display panel including a color filter substrate 310, a thin film transistor substrate 320, and a liquid crystal layer (not shown) provided therebetween. Although not shown, the driving circuit unit and the upper accommodating member may be further included.

At this time, the color filter substrate 310 is a substrate in which RGB pixels, which are color pixels in which a predetermined color is expressed while light passes, are formed by a thin film process. A common electrode made of a transparent conductor such as indium tin oxide (ITO) or indium zinc oxide (IZO) is coated on the front surface of the color filter substrate 310.

The TFT substrate 320 is a transparent glass substrate on which TFTs in matrix form are formed. The data line is connected to the source terminal of the TFTs, and the gate line is connected to the gate terminal. In addition, a pixel electrode made of a transparent electrode made of a transparent conductive material is formed in the drain terminal. When an electrical signal is input to the data line and the gate line, each TFT is turned on or turned off to apply an electrical signal necessary for pixel formation of the drain terminal. When the TFT is turned on by applying power to the gate terminal and the source terminal of the TFT substrate 320, an electric field is formed between the pixel electrode and the common electrode of the color filter substrate 310, thereby forming the TFT substrate 320 and the color. The arrangement of the liquid crystal layer injected between the filter substrates 310 is changed, and the light transmittance is changed according to the changed arrangement to obtain a desired image.

In addition, the driving circuit unit connected to the TFT substrate 320 includes a printed circuit board (not shown) for applying a gate signal and a data signal to the gate line and the data line of the TFT substrate 320, respectively. Of course, it may further include a flexible printed circuit board connecting the printed circuit board and the TFT substrate 320. In addition, the liquid crystal display panel may include a driving IC, which may be mounted on the TFT substrate 320 or may be mounted on a flexible printed circuit board or a printed circuit board.

The backlight assembly 2000 may include an LED lamp unit 700, a light guide plate 500 coupled to the LED lamp unit 700, a plurality of optical sheets 400 installed on the light guide plate 500, and a light guide plate ( And a lower accommodating member 600 accommodating the optical sheet 400 and the LED lamp unit 700. Here, the light guide plate 500 may further include a reflecting plate 510 provided on the bottom surface of the lower accommodating member 600.

The LED lamp unit 700 includes a white LED lamp 710, a flexible circuit board 720 on which the white LED lamp 710 is mounted, and a white adhesive member 730 provided on the flexible circuit board 720. do.

The white LED lamp 710 uses an LED lamp that emits white light, but preferably uses an LED lamp that emits side light. At this time, the white light is coupled to the light emitting chip emitting R, G, B inside the white LED lamp 710 to emit white light, or emit light of any one of R, G and B and the corresponding phosphor It can emit white light using. In addition, it is preferable that a region other than the region where white light is emitted for side emission is provided as a shielding region. In this embodiment, four white LED lamps 710 are used as shown in the figure. The four white LED lamps 710 may be spaced at uniform intervals to supply uniform white light to the light guide plate 500. However, the present embodiment is not limited to this number, it is preferable to use at least one white LED lamp 710.

The flexible printed circuit board 720 mounted with the white LED lamp 710 described above is flexible as shown in FIG. 4, and a conductive material is patterned on the base film 721 and the base film 721. Metal wires 722 for transmitting an electrical signal and a protective film 723 formed on the base film 721 to protect the metal wires 722.

The flexible circuit board 720 includes a first extension part extending in one direction and a second extension part extending in a direction perpendicular thereto as shown in FIG. 3. A plurality of white LED lamps 710 are mounted on the first extension part, and a white adhesive member 730 is provided on an upper portion thereof to bond the lower accommodating member 600 and the flexible circuit board 720 to each other. In this case, the first and second extensions may be manufactured integrally, and may be separately manufactured and then combined.

As shown in FIG. 3, the base film 721 is fabricated into an L shape, and the metal wiring 722 is patterned thereon.

In this case, the metal wires 722 include a ground wire and a voltage wire for applying power to the white LED lamp 710. Of course, although four metal wires 722 are illustrated in FIG. 4, a plurality of metal wires 722 are not limited thereto.

A part of the protective film 723 is provided with a mounting groove 711 in which a white LED lamp 710 is mounted, and a part of the metal wiring 722 is exposed through the mounting groove 711. Accordingly, when the white LED lamp 710 is mounted in the mounting groove 711, each of the anode terminal and the cathode terminal of the white LED lamp 710 is connected to the metal wiring 722.

In the present embodiment, a white adhesive member 730 is coated on the protective film 723. As the white adhesive member 730, a white double-sided tape may be used, and a white adhesive may be used. At this time, the white adhesive member 730 is preferably applied to the entire first extension. By applying the white adhesive member 730 on the flexible circuit board 720, a phenomenon in which the light refracted by the direction irradiated toward the flexible circuit board 720 becomes yellow may be prevented. That is, the white light irradiated in the direction of the flexible circuit board 720 may be reflected by the white adhesive member 730 provided on the surface thereof and may be irradiated onto the light guide plate 500 without changing the color of the light. Then, the white LED lamp 710 is mounted on the flexible circuit board 720, and then the white adhesive member 730 is directly applied without the conventional white film coating process. In this way, a single film (white adhesive member) having both the conventional white film and the adhesive member properties can be formed, thereby simplifying the manufacturing process and reducing the raw materials for manufacturing the LED lamp unit 700, thereby reducing the manufacturing cost. Can save. Of course, the present embodiment is not limited thereto, and the white adhesive member 730 is coated on the protective film 723 of the flexible circuit board 720, and then the white LED lamp 710 is attached to the flexible circuit board 720. Can also be mounted on.

The light guide plate 500 is disposed in the lower accommodating member 600 so as to be adjacent to the LED lamp unit 700 to distribute light having a light distribution in the form of a line light source generated by the plurality of LED lamps 710. Change to light having As the light guide plate 500, a wedge type plate or a parallel flat plate may be used. In addition, the light guide plate 500 is generally formed of polymethylmethacrylate (PMMA) having high strength and not easily being deformed or broken and having good transmittance. As shown in FIG. 5, a reflecting plate 510 is provided under the light guide plate. At this time, by using a plate having a high light reflectance as a reflecting plate to reflect the light incident to itself through the back of the light guide plate 500 to the light guide plate 500 serves to reduce the light loss. The reflection plate 510 is installed to contact the bottom surface of the lower housing member 600. In addition, when a material having excellent reflection efficiency is formed on the bottom surface of the lower accommodating member 600, a separate reflecting plate 510 may be omitted, or the lower accommodating member 600 and the reflecting plate 510 may be integrally formed. .

The plurality of optical sheets 400 include a diffusion sheet, a polarizing sheet, and a brightness enhancing sheet, which are disposed on the light guide plate 500 to uniform the luminance distribution of the light emitted from the light guide plate 500. The diffusion sheet directs the light incident from the lower light guide plate toward the front of the liquid crystal display panel, and diffuses the light to have a uniform distribution in a wide range so that the liquid crystal display panel is irradiated. As the diffusion sheet, it is preferable to use a film composed of a transparent resin coated with a predetermined light diffusion member on both surfaces. The polarizing sheet serves to change the light incident obliquely among the light incident on the polarizing sheet to be emitted vertically. This is because the light efficiency increases when the light incident on the liquid crystal display panel is perpendicular to the liquid crystal display panel. Therefore, at least one polarizing sheet may be disposed under the liquid crystal display panel in order to vertically convert light emitted from the polarizing sheet. In this embodiment, two polarizing sheets are used, but a first polarizing sheet for polarizing light of the diffusion sheet in one direction and a second polarizing sheet for polarizing light in a direction perpendicular to the first polarizing sheet. The brightness enhancing sheet transmits light parallel to its transmission axis and reflects light perpendicular to the transmission axis. It is preferable that the transmission axis of such a brightness improving sheet is the same as the polarization axis and direction of a polarizing sheet in order to raise transmission efficiency.

The lower accommodating member 600 is formed in a box shape of a rectangular parallelepiped with an open upper surface, and an accommodating space having a predetermined depth is formed therein. The lower accommodating member 800 includes a bottom surface, sidewalls extending vertically from three edges of the bottom surface, and an LED lamp unit coupling part 610 provided at one edge of the bottom surface. The LED lamp unit coupling part 610 is manufactured in a rectangular pillar shape with an empty inside, and a through hole 620 through which the white LED lamp 710 is inserted is provided at an upper side thereof, and an inner side thereof is opened to emit side light. The light of the white LED lamp 710 can be directed to the light guide plate 500 area. At this time, the inner surface of the LED lamp unit coupling unit 610 is preferably coated with a film having excellent light reflectance. In addition, the LED lamp unit coupling unit 610 may be made of a white material to prevent distortion of white light of the white LED lamp 710 of the LED lamp unit 700 as described above.

In this case, the width of the upper surface of the LED lamp coupling portion 610 is preferably equal to or smaller than the width of the flexible circuit board 720 on which the white LED lamp 710 is mounted. In addition, the LED lamp coupling unit 610 may be manufactured to a thickness in which the amount of light emitted from the white LED lamp 710 due to the LED lamp coupling unit 610 is not reduced. In the present embodiment, a white adhesive member 730 is applied on the flexible circuit board 720 of the LED lamp unit 700 coupled with the LED lamp coupling part 610 to reinforce the bonding force therebetween. In this case, an adhesive member (not shown) may also be provided on the upper surface of the LED lamp coupling part 610. The LED lamp coupling part 610 may be manufactured integrally with the bottom surface and the sidewall of the lower accommodating member 600, or may be manufactured through a separate process and then coupled to the bottom surface and the sidewall.

That is, the LED lamp unit 700 is rotated 180 degrees in the direction of the arrow of FIG. 3 to be coupled to the LED lamp coupling part 610 of the lower accommodating member 600. In this case, a reflective plate 510 and a light guide plate 500 are provided on the bottom surface of the lower accommodating member 600, as shown in FIG. 5. In this case, as described above, since the width of the flexible circuit board 720 of the LED lamp unit 700 is wider than that of the LED lamp coupling 610 of the lower accommodating member 600, a part of the light guide plate 500 is part of the light guide plate 500. Can be adhered to. In addition, in the present embodiment, the white LED lamp 710 of the LED lamp unit 700 is introduced into the LED lamp coupling portion 610 and the through hole 620, the flexible circuit board 720 of the LED lamp unit 700 White adhesive member 730 is coated on the) to enhance the bonding force of the LED lamp unit 700 and the lower housing member 600. In addition, a white white adhesive member 730 is provided on the flexible circuit board 720 on which the white LED lamp 710 which emits side light is distorted so that white light due to the flexible circuit board 720 is distorted. Can be prevented to improve the color reproducibility of the liquid crystal display.

Although not shown in the drawing, the present embodiment further includes an upper accommodating member to prevent the components of the display assembly 1000 from being separated and at the same time, the liquid crystal display panel and the backlight assembly 200 which are easily broken by an externally applied shock. ) Is desirable.

As described above, the present invention can mount the LED lamp on the flexible circuit board to thin the backlight assembly.

In addition, by applying a white adhesive member on the flexible circuit board on which the LED lamp is mounted can improve the adhesive force between the lower structure and the LED lamp unit, it is possible to prevent the distortion of the white light emitted by the LED lamp.

In addition, by applying a white adhesive member in a single process it is possible to simplify the process and reduce the manufacturing cost.

Although the invention has been described with reference to the accompanying drawings and the preferred embodiments described above, the invention is not limited thereto, but is defined by the claims that follow. Accordingly, one of ordinary skill in the art may variously modify and modify the present invention without departing from the spirit of the following claims.

Claims (12)

LED lamps; A flexible printed circuit board on which the LED lamp is mounted; LED lamp unit comprising a white adhesive member provided on the flexible circuit board. The method according to claim 1, The LED lamp unit is a LED lamp unit which is a white LED emitting side light. The method according to claim 1, The white adhesive member is a white double-sided tape or a white opaque adhesive LED lamp unit. The method according to claim 1, The flexible circuit board includes a flexible base film, a metal wiring applied on the base film, and a protective film provided on the base film to protect the metal wiring. The method according to claim 4, The protection film is partially cut in order to mount the LED lamp, the LED lamp unit is coated with the white adhesive member on the cut protective film. An LED lamp unit including a flexible printed circuit board on which a white LED lamp is mounted and a white adhesive member provided on the flexible circuit board; An accommodation member accommodating the LED lamp unit; And a light guide plate provided inside the accommodating member and disposed adjacent to the LED lamp unit. The method according to claim 6, The accommodation member includes a LED lamp coupling portion connected to the LED lamp unit through the white adhesive member, the LED lamp coupling portion includes a plurality of through holes through which the white LED lamp is drawn. The method according to claim 7, The flexible circuit board may include a connection area connected to the LED lamp coupling part and an extension area extending outside the accommodation member. The method according to claim 8, And a white adhesive member on the connection area. The method according to claim 6, The white adhesive member is a white double sided tape or a white opaque adhesive. A flexible printed circuit board on which a white LED lamp for generating light is mounted, an LED lamp unit including a white adhesive member provided on the flexible circuit board, an accommodating member for accommodating the LED lamp unit, and an inside of the accommodating member. A backlight assembly including a light guide plate disposed adjacent to the LED lamp unit; And a liquid crystal display panel configured to display an image by using light supplied from the backlight assembly. The method according to claim 11, The white adhesive member is a white double-sided tape or a white opaque adhesive.

Images