KR20180028821A - Borderless-type liquid crystal display device - Google Patents

Abstract

A borderless-type liquid crystal display device according to the present invention can eliminate a structure for covering a pad part and a flexible film by reversely coupling a liquid crystal panel so that a thin film transistor array substrate is located on the upper side of a color filter substrate. According to the present invention, the quality of an outer appearance can be improved by easily implementing a four-sided borderless-type liquid crystal display device to minimize a width of a bezel area. The borderless-type liquid crystal display device according to the present invention can improve brightness by reusing light by reflecting the light which is absorbed by adding a reflecting layer to the lower side of the black matrix of the color filter substrate.

Description

[0001] BORDERLESS-TYPE LIQUID CRYSTAL DISPLAY DEVICE [0002]

The present invention relates to a borderless type liquid crystal display device.

Recently, interest in information display has increased, and a demand for using portable information media has increased, and a light-weight flat panel display (FPD) that replaces a cathode ray tube (CRT) And research and commercialization are being carried out. Particularly, among such flat panel display devices, a liquid crystal display (LCD) is an apparatus for displaying an image using the optical anisotropy of a liquid crystal, and is excellent in resolution, color display and picture quality and is actively applied to a notebook or a desktop monitor have.

Hereinafter, the structure of a general liquid crystal display device will be described in detail with reference to the drawings.

1 is a cross-sectional view schematically showing a part of a structure of a general liquid crystal display device.

1, a typical liquid crystal display device includes a liquid crystal panel 10, a driving circuit (not shown), a backlight unit, a liquid crystal panel 10, and a plurality of guide parts for supporting the backlight unit.

The liquid crystal panel 10 is composed of an upper substrate and a lower substrate which are arranged in a matrix shape to output an image and are bonded together with a liquid crystal layer interposed therebetween to control light transmittance.

The upper substrate is composed of a color filter substrate 5 and the lower substrate is composed of a thin film transistor array substrate 15 (hereinafter referred to as an array substrate).

Although not shown, the color filter substrate 5 includes a color filter composed of a plurality of sub-color filters implementing colors of red (R), green (G) and blue (B) A black matrix (BM) for separating the color filters from each other and blocking light transmitted through the liquid crystal layer, and a transparent common electrode for applying a voltage to the liquid crystal layer.

The array substrate 15 includes a plurality of gate lines and data lines arranged vertically and horizontally to define a plurality of pixel regions, a thin film transistor as a switching element formed in a crossing region between the gate line and the data line, and a pixel electrode formed in the pixel region consist of.

The color filter substrate 5 and the array substrate 15 constructed as described above are adhered to each other by a sealant (not shown) formed on the periphery of the image display area to constitute the liquid crystal panel 10. [

At this time, in the general liquid crystal display device, the lower array substrate 15 of the liquid crystal panel 10 is larger than the upper color filter substrate 5. Therefore, the liquid crystal panel 10 is exposed to the outside when viewed from the top, and the exposed portion of the array substrate 15 constitutes a pad portion.

The driver circuit portion drives the pixels and includes a gate driver, a data driver, a timing controller, and a backlight driver.

The data driver is integrated into a number of source driver integrated circuits (ICs). Each of the source driver ICs is mounted on the flexible film 60. The flexible film 60 is attached to the source printed circuit board 65 to which one side is attached to the pad portion of the array substrate 15 of the liquid crystal panel 10 and the other side is attached to the back side of the lower cover 50.

The upper and lower polarizers 1 and 11 are attached to the outside of the liquid crystal panel 10 and the lower polarizer 11 polarizes the light passing through the backlight unit and the upper polarizer 1 is attached to the liquid crystal panel 10 Polarized light.

A light emitting diode (LED) assembly 30 for emitting light is provided at one side of a light guide plate 42. A light emitting diode (41).

The LED assembly 30 includes an LED array 31 and an LED array printed circuit board (PCB) 32 for driving the LED array 31.

The light emitted from the LED array 31 is incident on the side surface of the light guide plate 42 of transparent material and the reflection plate 41 disposed on the back surface of the light guide plate 42 reflects light transmitted through the back surface of the light guide plate 42 to the light guide plate 42 To the optical sheets 43 on the upper surface, thereby reducing the loss of light and improving the uniformity.

The liquid crystal panel 10 including the color filter substrate 5 and the array substrate 15 is mounted on the upper part of the backlight unit thus configured through the guide panel 45 and the lower cover 50 is coupled to the lower part thereof, Thereby constituting a device.

The guide part includes an outer cover (or a top case) 54, a back cover 55, etc. in addition to the guide panel 45 and the lower cover 50.

The lower cover 50 is made of a metal of a rectangular frame and covers the side and bottom of the backlight unit.

The guide panel 45 guides the liquid crystal panel 10 by supporting the array substrate 15 of the liquid crystal panel 10. The array substrate 15 of the liquid crystal panel 10 can be attached to the guide panel 45 using the double-faced tape 46. [

The outer cover 54 may be attached to the liquid crystal panel 10 so as to cover a part of the edge of the upper polarizer 1 and a pad portion of the array substrate 15. [ The outer cover 54 may be formed in the same color as the liquid crystal panel 10. For example, when power is not applied to the liquid crystal panel 10, since the liquid crystal panel 10 is displayed in black, the cover 54 may be formed in black.

As such, the conventional liquid crystal display device has a problem that the image display area where the image is displayed is relatively reduced as the cover 54 covers the bezel, which is the upper edge of the liquid crystal panel 10.

Therefore, in order to widen the image display area, researches for minimizing the width of the bezel area have been continued.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a four-sided borderless type liquid crystal display device in which the width of a bezel region is minimized.

Another object of the present invention is to provide a borderless type liquid crystal display device which reflects light absorbed in a black matrix of a lower color filter substrate and recycles the same.

Other objects and features of the present invention will be described in the following description of the invention and the claims.

According to an aspect of the present invention, there is provided a borderless type liquid crystal display device including a lower substrate and an upper substrate having a larger area than the lower substrate, A backlight unit positioned below the lower substrate, and a lower cover for receiving and fixing the backlight unit.

At this time, the lower substrate includes a reflective layer under the black matrix, and the light emitted from the backlight unit is reflected and recycled.

And a source printed circuit board attached to a back surface of the lower cover, on which a power supply for driving the liquid crystal panel and a control circuit are mounted.

The flexible printed circuit board may further include a flexible film having one end bonded to the pad portion of the liquid crystal panel and the other end bent to the source printed circuit board.

The lower substrate may be a color filter substrate, and the upper substrate may be a thin film transistor array substrate.

The reflective layer may be made of a reflective metal of aluminum, copper, silver, nickel, or an alloy thereof.

The reflective layer may be made of a white ink or a reflective material of a white pigment.

At this time, the white pigment may include at least one material selected from titanium oxide, aluminum paste, aluminum powder, silicon oxide, aluminum oxide, zirconium oxide, magnesium fluoride, barium sulfate and calcium carbonate.

An antioxidant layer disposed under the reflective layer may be further included.

The reflective layer may have a lattice shape under the black matrix and surround the edge of the pixel region like the black matrix.

The reflective layer may have a width equal to or smaller than that of the black matrix.

The black matrix may be configured to surround not only the upper surface of the reflective layer but also the side surface.

As described above, in the borderless type liquid crystal display device according to the embodiment of the present invention, the liquid crystal panel is turned upside down and the array substrate is positioned on the color filter substrate, thereby making it possible to eliminate the pad portion and the mechanism for shielding the flexible film . Therefore, the present invention provides a four-sided borderless type liquid crystal display device that can be easily implemented, thereby improving appearance quality.

In addition, a borderless type liquid crystal display device according to an embodiment of the present invention adds a reflective layer to the lower portion of the black matrix of the color filter substrate to reflect the absorbed light, thereby providing an effect of increasing brightness by recycling the absorbed light.

1 is a cross-sectional view schematically showing a part of a structure of a general liquid crystal display device.
2 is a diagram illustrating an exemplary structure of a liquid crystal display device according to the present invention.
3 is a cross-sectional view schematically showing a part of a structure of a borderless type liquid crystal display device according to a first embodiment of the present invention.
FIG. 4 is a cross-sectional view schematically showing a part of a structure of a liquid crystal panel in a borderless type liquid crystal display device according to the first embodiment of the present invention shown in FIG. 3;
5 is a plan view schematically showing a pixel structure of a liquid crystal panel according to a first embodiment of the present invention.
6 is a cross-sectional view schematically showing a part of a structure of a liquid crystal panel according to a second embodiment of the present invention.

Hereinafter, preferred embodiments of the borderless type liquid crystal display according to the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification. The dimensions and relative sizes of the layers and regions in the figures may be exaggerated for clarity of illustration.

It will be understood that when an element or layer is referred to as being another element or "on" or "on ", it includes both intervening layers or other elements in the middle, do. On the other hand, when a device is referred to as "directly on" or "directly above ", it does not intervene another device or layer in the middle.

The terms spatially relative, "below," "lower," "above," "upper," and the like, And may be used to easily describe the correlation with other elements or components. Spatially relative terms should be understood to include, in addition to the directions shown in the drawings, terms that include the different directions of the elements in use, or in operation. For example, when inverting an element shown in the figures, an element described as "below" or "beneath" of another element may be placed "above" another element. Thus, the exemplary term "below" can include both downward and upward directions.

The terminology used herein is for the purpose of describing embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. &Quot; comprise "and / or" comprising ", as used in the specification, means that the presence of stated elements, Or additions.

2 is a view illustrating an exemplary structure of a liquid crystal display device according to the present invention. However, the present invention is not limited to the structure shown in Fig.

2, the liquid crystal display device according to the present invention may include a liquid crystal panel 110 in which pixels are arranged in a matrix form to output an image, and a driving circuit unit for driving pixels of the liquid crystal panel 110 have.

The driving circuit includes a gate driver 111 for driving the gate lines GL of the liquid crystal panel 110, a data driver 112 for driving the data lines DL of the liquid crystal panel 110, A timing controller 113 for controlling the driving timings of the data drivers 112 and 111 and the data driver 112 and a power supply 114 for supplying the driving voltages VDD, VGH, VGL, have.

The liquid crystal panel 110 has a pixel matrix composed of pixels formed in regions defined by the intersections of the gate lines GL and the data lines DL. Each of the pixels includes a liquid crystal cell (LC) for adjusting the light transmittance according to the pixel signal and a thin film transistor (TFT) for driving the liquid crystal cell (LC).

The thin film transistor TFT is turned on when a gate-on voltage VGH from the gate line GL is supplied to supply a pixel signal from the data line DL to the liquid crystal cell LC . The thin film transistor TFT is turned off when the gate-off voltage VGL is supplied from the gate line GL so that the pixel signal charged in the liquid crystal cell LC is maintained.

The liquid crystal cell LC is equivalently represented by a capacitor, and is composed of a common electrode facing the liquid crystal layer and a pixel electrode connected to the thin film transistor (TFT). The liquid crystal cell LC further includes a storage capacitor (not shown) so that the charged pixel signal stably remains until the next pixel signal is charged. In such a liquid crystal cell LC, the alignment state of the liquid crystal having dielectric anisotropy varies according to the pixel signal charged through the thin film transistor (TFT), and the light transmittance is adjusted to realize the gray level.

The gate driver 111 shifts a gate start pulse (GSP) from the timing controller 113 according to a gate shift clock (GSC) to sequentially supply power to the gate lines GL On voltage (VGH) from a scan driver (not shown). The gate driver 111 supplies the gate-off voltage VGL from the power supply unit 114 during the remaining period when the scan pulse of the gate-on voltage VGH is not supplied to the gate lines GL. The gate driver 111 controls the pulse width of the scan pulse in accordance with a gate output enable (GOE) signal from the timing controller 113.

The data driver 112 generates a sampling signal by shifting a source start pulse (SSP) from the timing controller 113 according to a source shift clock (SSC). The data driver 112 latches pixel data (RGB) input according to the SSC according to a sampling signal, and supplies the pixel data in units of lines in response to a source output enable (SOE) signal. Then, the data driver 112 converts the gamma voltage from the gamma voltage unit (not shown) into an analog pixel signal according to the pixel data RGB supplied in units of a line, and supplies the analog pixel signal to the data lines DL. Here, the data driver 112 determines the polarity of the pixel signal in response to the polarity control (POL) signal from the timing controller 113 when converting the pixel data into the pixel signal.

Then, the data driver 112 determines the period of time in which the pixel signal is supplied to the data lines DL in response to the source output enable (SOE) signal.

The timing controller 113 generates a GSP, a GSC and a GOE signal for controlling the gate driver 111 and generates SSP, SSC, SOE, and POL signals for controlling the data driver 112. In this case, the timing controller 113 transmits a data enable (DE) signal, a horizontal synchronizing signal (Hsync), a vertical synchronizing signal (Vsync), and pixel data (RGB) Control signals such as GSP, GSC, GOE, SSP, SSC, SOE, and POL are generated using a dot clock (DCLK) for determining the timing.

The power supply unit 114 generates an IC digital driving voltage, an IC analog driving voltage VDD, a gate-on voltage VGH, a gate-off voltage VGL, and the like using the input driving voltage VCC. The power supply unit 114 supplies the IC digital driving voltage to the timing controller 113 and the data driver 112 and the IC analog driving voltage VDD to the data driver 112 and the gate- Off voltage VGL to the gate driver 111. [ The power supply unit 114 generates a common voltage that is a reference for driving the liquid crystal cell LC of the liquid crystal panel 110 and supplies the common voltage to the common electrode.

In the liquid crystal display device constructed as described above, the gate driver 111 and the data driver 112 are integrated into a plurality of ICs (not shown).

The integrated gate driver IC and the data driver IC are mounted on a Tape Carrier Package (TCP) or a Chip On Film (COF) and are mounted on a liquid crystal panel 110 Or may be mounted on the liquid crystal panel 110 in a chip on glass (COG) type.

3 is a cross-sectional view schematically showing a part of a structure of a borderless type liquid crystal display device according to a first embodiment of the present invention.

FIG. 4 is a cross-sectional view schematically showing a part of a structure of a liquid crystal display of a borderless type liquid crystal display according to a first embodiment of the present invention shown in FIG. 4, a fringe field formed between the pixel electrode and the common electrode passes through the slit, and fringe field switching (FFS), which realizes an image by driving liquid crystal molecules located on the pixel region and the common electrode, A part of the liquid crystal panel of the type shown in FIG. However, the present invention is not limited to this, and is applicable to an in-plane switching (IPS) type liquid crystal display device using a transverse electric field as well as an FFS method.

5 is a plan view schematically illustrating a pixel structure of a liquid crystal panel according to the first embodiment of the present invention, and shows a part of a pixel structure in a matrix form as an example.

3 to 5, a borderless type liquid crystal display device according to the first embodiment of the present invention includes a liquid crystal panel 110, a driving circuit unit (not shown), a backlight unit and a liquid crystal panel 110, And a plurality of guide parts for supporting the guide part.

The borderless type liquid crystal display device according to the first embodiment of the present invention includes a printed circuit board 165 on which a power supply unit and a control circuit for driving the liquid crystal panel 110 are mounted, And a flexible film 160 connecting the printed circuit board 165 to the printed circuit board 165. [

The liquid crystal panel 110 is composed of an upper substrate and a lower substrate which are arranged in a matrix shape to output images and are bonded together with a liquid crystal layer interposed therebetween to control light transmittance.

Here, the borderless type liquid crystal display device according to the first embodiment of the present invention is characterized in that the upper substrate is composed of the array substrate 115 and the lower substrate is formed of the color filter substrate 105. That is, in the borderless type liquid crystal display device according to the first embodiment of the present invention, the liquid crystal panel 110 is turned over and the array substrate 115 having a relatively large area is placed on the color filter substrate 105 . Accordingly, since the pads formed on the upper array substrate 115 are disposed to face the back side of the liquid crystal panel 110, it is possible to remove the components such as an external cover (or a top case) for covering the pads, You can implement a lease type.

At this time, a thin film transistor as a switching element and various wirings and electrodes are formed on the array substrate 115 to define a pixel region AA. The color filter substrate 105 is provided with a color filter 107 for displaying three primary colors of red (R), green (G) and blue (B) A black matrix (BM) 106 may be formed.

That is, on the array substrate 115, a plurality of gate lines (not shown) and data lines (not shown) are arranged vertically and horizontally and define a plurality of pixel regions AA, And a pixel electrode 118 formed in the pixel region may be formed.

The color filter substrate 105 is provided with a color filter 107 composed of a plurality of sub-color filters that implement the colors of red (R), green (G) and blue (B) A black matrix 106 for blocking light transmitted through the layer may be formed. A lower polarizer 111 is formed on the outer surface of the color filter substrate 105.

When the liquid crystal panel 110 is a vertical electric field system such as a twisted nematic (TN) system, a common electrode is formed on the color filter substrate 105, and the liquid crystal panel 110 is formed using IPS or FFS The common electrode 108 may be formed on the array substrate 115 together with the pixel electrode 118. In this case,

The thin film transistor may include a gate electrode 121 connected to the gate line, a source electrode 122 connected to the data line, and a drain electrode 123 electrically connected to the pixel electrode 118 through the contact hole. The thin film transistor is connected to the source electrode 122 and the drain electrode by a gate voltage supplied to the gate insulating film 112a and the gate electrode 121 for insulation between the gate electrode 121 and the source / And an active layer 124 between the electrodes 123 to form a conductive channel.

At this time, when the amorphous silicon thin film is used as the active layer 124, the source / drain regions of the active layer 124 form ohmic contacts with the source / drain electrodes 122 and 123 through the ohmic-contact layer 125n . However, the present invention is not limited thereto, and a polycrystalline silicon thin film or an oxide semiconductor may be used for the active layer 124.

This thin film transistor supplies the data voltage supplied from the data line to the pixel electrode 118 in response to the gate signal provided from the gate line. The upper polarizer 101 is formed on the outer surface of the array substrate 115.

As described above, the common electrode 108 and the pixel electrode 118 are formed in the pixel region AA to generate a fringe field. At this time, the common electrode 108 is formed on the interlayer insulating layer 112b and the planarization layer 112c, and may be formed in a single pattern over the entire pixel except for the contact hole. The pixel electrode 118 may be formed in a box shape within each pixel region AA while having a plurality of slits 118s on the protective film 112d. However, the present invention is not limited thereto. Instead of the pixel electrode 118, the common electrode 108 may have a plurality of slits.

The array substrate 115 thus configured is bonded to the color filter substrate 105 in a state where the cell gap is maintained through the column spacer 119 to constitute the liquid crystal panel 110.

Next, the driver circuit portion drives the pixels and may include a gate driver, a data driver, a timing controller, and a backlight driver.

The gate driver and the data driver may be integrated into a plurality of driver integrated circuits (ICs) Each of the driver ICs 161 may be mounted on the flexible film 160. The flexible film 160 may be implemented as a COF (chip on film) or a flexible printed circuit board (FPCB). One side of the flexible film 160 may be attached to the pad portion of the array substrate 115 of the liquid crystal panel 110 and the other side may be attached to the back surface of the lower cover 150. However, the present invention is not limited thereto, and the other side of the flexible film 160 may be attached to the source printed circuit board 165 attached to the back surface of the lower cover 150.

That is, the source printed circuit board 165 may be attached to the back surface of the lower cover 150. On the source printed circuit board 165, a control circuit such as a system or a timing controller, and a power supply for generating power for driving the liquid crystal panel 110 and the backlight unit may be mounted. The control circuit of the source printed circuit board 165 and the power supply unit can supply various control signals and power to the pad portion of the liquid crystal panel 110 through the flexible film 160.

At least one flexible film 160 is provided to connect the liquid crystal panel 110 and the source printed circuit board 165 to each other. Specifically, one end of the flexible film 160 is bonded to the pad portion of the array substrate 115, and the other end of the flexible film 160 is bent from one end and connected to the source printed circuit board 165. The flexible film 160 may be composed of COF or TCP (Tape Carrier Package) on which the driver ICs 161 are mounted. The driver IC 161 may be a gate driver IC for driving the gate line of the liquid crystal panel 110 or a source driver IC for driving the data line of the liquid crystal panel 110.

At this time, the guide panel 145 may further protrude from the end of the color filter substrate 105 to form a predetermined space together with the pad portion of the upper array substrate 115. In this case, one end of the flexible film 160 bonded to the pad portion of the array substrate 115 can be fitted into the space between the array substrate 115 and the guide panel 145. In this case, the curvature formed on the flexible film 160 can be kept constant, thereby fixing the flexible film 160 to the pad portion of the array substrate 115.

The lower cover 150 is made of metal of a square frame and covers the side and bottom of the backlight unit.

The borderless type liquid crystal display device according to the first embodiment of the present invention may further include a cover member (not shown) and a casing member such as a back cover 155.

The cover shield may be joined to the back surface of the lower cover 150 while covering the back surface of the source printed circuit board 165 and the outer surface (side surface) of the flexible film 160 and the side surface of the liquid crystal panel 110.

The back cover 155 may include a bottom portion covering the bottom surface of the cover shield and the bottom surface of the cover 150 and a side portion surrounding the side surface of the flexible film 160 bent upward from the bottom portion.

The cover shield or the back cover 155 does not cover the upper edge of the liquid crystal panel 110 because the pad portion of the liquid crystal panel 110 faces the back side as described above. In addition, since the pad portion is not exposed to the outside, the outer cover can be removed, and the four-sided borderless design can be realized, and a more clean display design can be achieved, thereby improving the appearance quality.

Recently, a narrow bezel type and a borderless type liquid crystal display device in which the edge portion of the outer frame portion is removed according to market demand have been researched and developed.

The borderless type liquid crystal display device according to the embodiment of the present invention is characterized in that the image display area is made wider by omitting the outer cover that covers the front surface of the liquid crystal panel 110 to enhance the aesthetic appearance.

For reference, the liquid crystal display device in which the outer cover does not cover the front surface of the liquid crystal panel 110, or the outer cover that covers the front surface of the liquid crystal panel 110 is omitted, is generally referred to as a borderless type liquid crystal display device. Also, a liquid crystal display device implemented as an omission of an external cover covering the front surface of the liquid crystal panel 110 is generally referred to as a borderless-like liquid crystal display device.

At this time, black ink (not shown) may be applied along the edge where the upper polarizer 101 is not positioned on the back surface of the array substrate 115 exposed to the outside, that is, the surface of the array substrate 115 opposite to the pad portion. In this case, the backlight that leaks from the bottom to the edge of the liquid crystal panel 110 can be completely blocked, thereby improving the display quality.

Next, the backlight unit is a light source that can be selected by using any one of CCFL (Cold Cathode Fluorescence Lamp), HCFL (Hot Cathode Fluorescence Lamp), EEFL (External Electrode Fluorescence Lamp) or LED (Light Emitting Diode) But is not limited thereto. Hereinafter, for convenience of explanation, a case where an LED is used as a light source is taken as an example.

The backlight unit is divided into an edge type and a direct type according to the arrangement of the light sources. The edge type backlight unit has a structure in which a light guide plate 142 is disposed below the liquid crystal panel 110 and a light source is disposed on at least one side surface of the light guide plate 142. The direct-type backlight unit has a structure in which a diffusion plate is disposed under the liquid crystal panel 110 and a light source is disposed under the diffusion plate. Hereinafter, an edge type backlight unit will be described as an example for convenience of explanation.

The backlight unit according to the first embodiment of the present invention will be described in detail. For example, an LED assembly 130 including a light source for generating light is installed on one side of a light guide plate 142, And a reflection plate 141 is provided on the back surface of the reflection plate 142.

A plurality of optical sheets 143 may be disposed on the upper surface of the light guide plate 142 to improve the efficiency of light emitted from the light guide plate 142 and illuminate the liquid crystal panel 110.

However, the present invention is not limited to the structure of the above-described backlight unit, and any backlight unit of any structure can be applied to a borderless type liquid crystal display device according to the present invention.

The light guide plate 142 receives light from the light source and guides the light to the liquid crystal panel 110 side. At this time, the light provided from the light source is provided to the incident surface of the light guide plate 142. This incidence surface faces one of the side portions of the lower cover 150. That is, the light source is located on one side of the lower cover 150, and the incident surface of the light guide plate 142 faces the light emitting surface of the light source.

The light guide plate 142 may be made of plastic of PMMA.

The reflection plate 141 is positioned between the upper surface of the lower cover 150 and the back surface of the light guide plate 142. The reflection plate 141 reflects light from the light source and light from the light guide plate 142 toward the liquid crystal panel 110 side.

The LED assembly 130 may include an LED array 131, an LED array printed circuit board 133 for driving the LED array 131, and a housing (not shown).

The LED array 131 may comprise a light emitting package having at least one LED. The light emitting package may be a light emitting package having different colors, for example, a red light emitting diode, a green light emitting diode, and a blue light emitting diode.

The LED array 131 may be installed on the LED array printed circuit board 133 such that the light exit surface faces the incident surface of the light guide plate 142.

The LED array printed circuit board 133 may be positioned between the incident surface of the light guide plate 142 and the side surface of the lower cover 150. The LED array printed circuit board 133 may be formed with a plurality of power lines (not shown) and electrical components (not shown) for transmitting power to the light sources.

The LED array printed circuit board 133 may be a general printed circuit board (PCB) or a metal printed circuit board (M-PCB). Although not shown, the metal printed circuit board may be formed of a base layer made of aluminum or a copper alloy, and a conductor pattern formed on the thermally conductive resin layer and the thermally conductive resin layer formed on the base layer. These conductor patterns include the power supply lines described above.

The light source is connected to an inverter (not shown) to receive power and emit light.

The light emitted from the light source is incident on the side surface of the light guide plate 142 of the transparent material and the reflective sheet 141 disposed on the back surface of the light guide plate 142 reflects the light transmitted through the back surface of the light guide plate 142, And is reflected toward the optical sheets 143 to reduce light loss and improve uniformity.

At this time, the optical sheets 143 include a diffuser sheet and an upper and a lower prism sheet, and a protective sheet may be added.

The optical sheets 143 are provided between the upper surface of the light guide plate 142 and the rear surface of the liquid crystal panel 110. The edges of the optical sheets 143 are covered by the guide panel 145. The prism sheet condenses light from the light guide plate 142, and the diffusion sheet diffuses the light from the prism sheet, and the protective sheet serves to protect the prism sheet and the diffusion sheet. Light passing through the protective sheet is provided to the liquid crystal panel 110 side.

The guide panel 145 guides the liquid crystal panel 110 by supporting the color filter substrate 105 of the liquid crystal panel 110. The color filter substrate 105 of the liquid crystal panel 110 may be attached to the guide panel 145 using an adhesive means (not shown) such as a double-sided tape.

In the borderless type liquid crystal display device according to the first embodiment of the present invention configured as described above, the reflective layer 104 is added to the lower portion of the black matrix 106 of the color filter substrate 105 to reflect the absorbed light to be recycled So that the effect of increasing the luminance can be provided.

If the area of the pixel is assumed that K ^2, the area of the sub-pixel is K ^2/3, assuming a CD (Critical Dimension) of a data line in one-tenth the area of the data line is seen as K ^2/30 have.

Further, assuming the CD of the gate line area with one-tenth of the gate line can be seen as a K ^2/30. Thus, when located in the lower portion of the array substrate the liquid crystal panel, as shown in the past, reflecting the area ratio of the metal wiring such as the data line and the gate line ^{(K 2/30 + K 2} /30) / (K 2/3) × 100 = 20%.

On the other hand, in the flip type TFT in which the positions of the color filter substrate 105 and the array substrate 115 are reversed, since the color filter substrate 105 is positioned below the liquid crystal panel 110, a black matrix 106, the effect of recycling the backlight due to reflection of the metal can not be expected. However, since the color filter 107 and the black matrix 106 are located on the back surface of the liquid crystal panel 110 to absorb all the light directed toward the black matrix 106, A reduction of about 20% compared to the conventional liquid crystal display device occurs.

However, if the reflective layer 104 is present under the black matrix 106 as in the first embodiment of the present invention, assuming that the CD of the black matrix 106 is 3/20, the horizontal and vertical black matrices 106, the area can be seen as a K ^2/20 respectively. Therefore, when equal design a reflective layer 104 and the size of the black matrix 106, the reflection area ratio of the reflection layer 104 ^{(K 2/20 + K 2} /20) / (K 2/3) × 100 = 30%.

As described above, the transmittance by the recycling of light can be expected by adding a reflective layer 104 made of a metal or a reflective material below the black matrix 106. The reflective layer 104 can be formed by using a half-tone mask or a black matrix 106) itself can be formed without adding a mask.

The black matrix 106 may be formed of an organic film of a resin material. For example, the black matrix 106 may be made of an acrylic resin, an epoxy resin, a polyimide resin, or the like containing any one of carbon black and black pigment. Colored organic resin and the like can be applied.

The reflective layer 104 may be formed of a reflective metal such as aluminum, copper, silver, nickel, or an alloy thereof. The reflective layer 104 may be formed by coating a resin layer containing the metal powder or by vapor-depositing or coating a metal thin film.

An antioxidant layer (not shown) may be additionally formed under the metallic reflective layer 104 to prevent oxidation of the metal component.

The reflective layer 104 may be formed of a reflective material such as a white ink or a white pigment. The white pigment may include at least one material selected from titanium oxide, aluminum paste, aluminum powder, silicon oxide, aluminum oxide, zirconium oxide, magnesium fluoride, barium sulfate, and calcium carbonate.

The reflective layer 104 may be formed in a lattice shape surrounding the edge of the pixel region AA substantially under the black matrix 106 and under the black matrix 106.

The reflective layer 104 may have the same width as the black matrix 106 or may have a smaller width so as not to affect the transmittance.

In the first embodiment of the present invention, the reflective layer 104 is formed by overetching using the black matrix 106 as a mask, but the present invention is not limited thereto. A black matrix may be formed to cover the reflective layer after the reflective layer is deposited and patterned, which will be described in detail in the following second embodiment of the present invention.

6 is a cross-sectional view schematically showing a part of a structure of a liquid crystal panel according to a second embodiment of the present invention.

Here, the liquid crystal panel according to the second embodiment of the present invention shown in FIG. 6 has substantially the same configuration as the liquid crystal panel according to the first embodiment of the present invention except for the form of a black matrix.

As shown in FIG. 4, FIG. 6 schematically shows a part of an FFS type liquid crystal panel. However, the present invention is not limited thereto, and is applicable to an IPS or TN liquid crystal display device as well as an FFS method.

The borderless type liquid crystal display device according to the second embodiment of the present invention substantially includes the liquid crystal panel, the driving circuit portion, the backlight unit, the liquid crystal panel, and a plurality of backlight units Guide parts, and the like.

The borderless type liquid crystal display device according to the second embodiment of the present invention includes a printed circuit board on which a power supply unit and a control circuit for driving the liquid crystal panel are mounted, a flexible circuit board for connecting the pad unit of the liquid crystal panel and the printed circuit board, Film.

Referring to FIG. 6, the liquid crystal panel 210 is composed of an upper substrate and a lower substrate, in which pixels are arranged in a matrix form to output images, and a liquid crystal layer is interposed therebetween to control light transmittance.

In the borderless type liquid crystal display device according to the second embodiment of the present invention, the upper substrate is configured as an array substrate 215, and the lower substrate is configured as a color filter substrate 205. That is, in the borderless type liquid crystal display device according to the second embodiment of the present invention, the liquid crystal panel 210 is turned over and the array substrate 215 having a relatively large area is placed on the color filter substrate 205 . Accordingly, since the pad portion formed on the upper array substrate 215 is disposed to face the back side of the liquid crystal panel 210, it is possible to delete the structure such as an external cover (or a top case) for covering the pad portion, You can implement a lease type.

At this time, the array substrate 215 is provided with a plurality of gate lines (not shown) and data lines (not shown) arranged vertically and horizontally to define a plurality of pixel regions, a thin film transistor And a pixel electrode 218 formed in the pixel region may be formed.

The color filter substrate 205 is provided with a color filter 207 constituted by a plurality of sub-color filters for realizing colors of red, green and blue and a color filter 207 for separating the sub- A black matrix 206 may be formed. A lower polarizer (not shown) may be formed on the outer surface of the color filter substrate 205.

In the case where the liquid crystal panel 210 is a vertical electric field system such as a TN system, a common electrode is formed on the color filter substrate 205. When the liquid crystal panel 210 is a horizontal electric field system such as an IPS or FFS system, The common electrode 208 may be formed on the substrate 215 together with the pixel electrode 218. [

The thin film transistor may include a gate electrode 221 connected to a gate line, a source electrode 222 connected to a data line, and a drain electrode 223 electrically connected to the pixel electrode 218 through a contact hole. The thin film transistor is connected to the source electrode 222 and the drain electrode 222 by a gate voltage supplied to the gate insulating film 212a and the gate electrode 221 for insulation between the gate electrode 221 and the source / And an active layer 224 that forms a conducting channel between the electrodes 223.

At this time, when the amorphous silicon thin film is used as the active layer 224, the source / drain regions of the active layer 224 form ohmic contacts with the source / drain electrodes 222 and 223 through the ohmic-contact layer 225n . However, the present invention is not limited thereto, and a polycrystalline silicon thin film or an oxide semiconductor may be used for the active layer 224.

This thin film transistor supplies the data voltage supplied from the data line to the pixel electrode 218 in response to the gate signal provided from the gate line. An upper polarizer (not shown) may be formed on the outer surface of the array substrate 215.

As described above, the common electrode 208 and the pixel electrode 218 are formed in the pixel region to generate a fringe field. At this time, the common electrode 208 is formed on the interlayer insulating film 212b and the planarization film 212c, and may be formed in a single pattern over the entire pixel except for the contact hole. In addition, the pixel electrode 218 may be formed in a box shape within each pixel region, and may have a plurality of slits 218s on the protective film 212d. However, the present invention is not limited thereto. Instead of the pixel electrode 218, the common electrode 208 may have a plurality of slits.

The array substrate 215 thus configured is bonded to the color filter substrate 205 while maintaining the cell gap through the column spacer 219 to constitute the liquid crystal panel 210.

Next, although not shown, the driving circuit portion drives the pixels and may include a gate driver, a data driver, a timing controller, and a backlight driving portion.

The gate driver and the data driver can be integrated into a plurality of driver ICs. Each of the driver ICs may be mounted on a flexible film. The flexible film may be implemented with COF or FPCB. One side of the flexible film may be attached to the pad portion of the array substrate 215 of the liquid crystal panel 210, and the other side may be attached to the back surface of the lower cover. However, the present invention is not limited thereto.

The lower cover is made of metal of a rectangular frame, and covers the side and bottom of the backlight unit.

The borderless type liquid crystal display device according to the second embodiment of the present invention may further include a cover member and a casing member such as a back cover.

The cover shield may be joined to the back surface of the lower cover while covering the back surface of the source printed circuit board and the outer surface (side surface) of the flexible film and the side surface of the liquid crystal panel 210.

The back cover may have a bottom portion covering the bottom surface of the cover shield and the bottom surface of the cover, and a side portion folded upward from the bottom portion to surround the side surface of the flexible film.

The cover shield or the back cover does not cover the upper edge of the liquid crystal panel 210 because the pad portion of the liquid crystal panel 210 faces the back side as described above. In addition, since the pad portion is not exposed to the outside, the outer cover can be removed, and the four-sided borderless design can be realized, and a more clean display design can be achieved, thereby improving the appearance quality.

Next, a backlight unit according to a second embodiment of the present invention will be described in detail. For example, an LED assembly including a light source for generating light is installed on one side of a light guide plate, and a reflection plate is installed on the back side of the light guide plate .

Further, on the upper surface of the light guide plate, a plurality of optical sheets for irradiating the liquid crystal panel 210 can be arranged by improving the efficiency of light emitted from the light guide plate.

However, the present invention is not limited to the structure of the above-described backlight unit, and any backlight unit of any structure can be applied to a borderless type liquid crystal display device according to the present invention.

The LED assembly may comprise an LED array, an LED array printed circuit board and a housing for driving the LED array.

The light emitted from the light source is incident on the side surface of the light guide plate of a transparent material. The reflective sheet disposed on the back surface of the light guide plate reflects light transmitted through the back surface of the light guide plate toward the optical sheets on the upper surface of the light guide plate to reduce light loss and improve uniformity do.

At this time, the optical sheets include a diffusion sheet and upper and lower prism sheets, and a protective sheet may be added.

In the borderless type liquid crystal display device according to the second embodiment of the present invention configured as described above, the reflection layer 204 is added to the lower portion of the black matrix 206 of the color filter substrate 205 to reflect the absorbed light to be recycled So that the effect of increasing the luminance can be provided.

That is, the second embodiment of the present invention is similar to the first embodiment of the present invention in that a reflective layer 204 made of a metal or its equivalent reflective material is added to the lower portion of the black matrix 206, It is possible to expect an increase in transmittance.

As the black matrix 206, an organic film of the above-mentioned resin material can be applied. For example, a colored organic resin such as acrylic, epoxy or polyimide resin including any one of carbon black and black pigment can be applied.

The reflective layer 204 may be formed of a reflective metal such as aluminum, copper, silver, nickel, or an alloy thereof. The reflective layer 204 may be formed by coating a resin layer containing the metal powder or by vapor-depositing or coating a metal thin film.

An antioxidant layer (not shown) may be further formed under the metallic reflection layer 204 to prevent oxidation of the metal component.

The reflective layer 204 may be formed of a reflective material such as a white ink or a white pigment. The white pigment may include at least one material selected from titanium oxide, aluminum paste, aluminum powder, silicon oxide, aluminum oxide, zirconium oxide, magnesium fluoride, barium sulfate, and calcium carbonate.

The reflective layer 204 may be formed in a lattice shape surrounding the edge of the pixel region substantially under the black matrix 206 and substantially the same as the black matrix 206.

In particular, the reflective layer 204 according to the second embodiment of the present invention can be formed to have a smaller width than the black matrix 206 so as not to affect the transmittance. After the reflective layer 204 is first deposited and patterned And a black matrix 206 is formed so as to surround the reflective layer 204. That is, the black matrix 206 is formed so as to cover not only the upper surface of the reflective layer 204 but also the side surfaces thereof with the black matrix 206.

In this case, the influence of the electric field on the liquid crystal layer due to the metal of the reflective layer 204 can be minimized. Therefore, it is possible to prevent an image quality deterioration due to electric field distortion.

While a great many are described in the foregoing description, it should be construed as an example of preferred embodiments rather than limiting the scope of the invention. Therefore, the invention should not be construed as limited to the embodiments described, but should be determined by equivalents to the appended claims and the claims.

104, 204: reflective layer 105, 205: color filter substrate
106,206: Black matrix 107,207: Color filter
110, 210: array substrate 119, 219: column spacer
150: lower cover 160: flexible film

Claims (11)

A liquid crystal panel including a lower substrate and an upper substrate having a larger area than the lower substrate, wherein a pad portion is disposed on a back surface of the upper substrate;
A backlight unit positioned below the lower substrate; And
And a lower cover for receiving and fixing the backlight unit,
Wherein the lower substrate includes a reflective layer under the black matrix, and reflects the light emitted from the backlight unit to recycle the liquid crystal display. The borderless type liquid crystal display according to claim 1, further comprising a source printed circuit board attached to a back surface of the lower cover, on which a power source for driving the liquid crystal panel and a control circuit are mounted. The liquid crystal display device of claim 2, further comprising a flexible film having one end bonded to the pad portion of the liquid crystal panel and the other end bent to the source printed circuit board, . The liquid crystal display of claim 1, wherein the lower substrate is a color filter substrate and the upper substrate is a thin film transistor array substrate. The liquid crystal display of claim 1, wherein the reflective layer is a reflective metal of aluminum, copper, silver, nickel, or an alloy thereof. The liquid crystal display of claim 1, wherein the reflective layer comprises a white ink or a reflective material of a white pigment. The white pigment according to claim 6, wherein the white pigment is at least one selected from the group consisting of a borderless liquid crystal material including at least one material selected from titanium oxide, aluminum paste, aluminum powder, silicon oxide, aluminum oxide, zirconium oxide, magnesium fluoride, barium sulfate, Display device. The Borderless type liquid crystal display of claim 1, further comprising an oxidation prevention layer provided under the reflective layer. The liquid crystal display of claim 1, wherein the reflective layer has a lattice shape under the black matrix and surrounds the edge of the pixel area like the black matrix. The liquid crystal display of claim 1, wherein the reflective layer has a width equal to or smaller than that of the black matrix. The liquid crystal display of claim 1, wherein the black matrix is configured to surround not only the upper surface but also the side surface of the reflective layer.

Images