KR102594445B1 - Liquid crystal display device - Google Patents

Abstract

In the present invention, a transmission control film capable of adjusting transmittance is applied to the backlight unit as an optical member, and in particular, the transmission control film is placed on the top or bottom of the diffusion sheet.
Accordingly, it is possible to improve CR while improving light leakage defects of the liquid crystal display device.

Description

Liquid crystal display device

The present invention relates to a liquid crystal display device, and more specifically, to a liquid crystal display device that can improve CR (Contrast Ratio) by controlling the transmittance of a backlight unit.

As the information society develops, the demand for display devices for displaying images is increasing in various forms, and in recent years, liquid crystal display devices (LCDs), plasma display panels (PDPs), organic Various flat display devices such as organic light emitting diodes (OLED) are being used.

Among these flat panel displays, liquid crystal displays are widely used because they have the advantages of miniaturization, weight reduction, thinness, and low-power operation.

Figure 1 is a cross-sectional view schematically showing a conventional liquid crystal display device.

Referring to FIG. 1, a conventional liquid crystal display device consists of a liquid crystal panel 10, a backlight unit 20 below it, a guide panel 30, a top gate 40, and a bottom cover 50.

The backlight unit 20 includes a light emitting diode (LED) 29 as a light source, a light guide plate 23, a reflector 21 below the light guide plate 23, and a plurality of optical sheets 25 above the light guide plate 23. It consists of

Meanwhile, as the liquid crystal panel 10, a transverse electric field type liquid crystal panel that can implement a fast response speed and a wide viewing angle can be used.

However, due to the characteristics of the transverse electric field method, light leakage occurs in the side direction, resulting in light leakage defects.

Moreover, the liquid crystal panel 10 is bent at the edges due to the influence of load, etc., and such bending causes a strong problem of light leakage at the corners. Refer to FIG. 2 for this.

In this way, in conventional liquid crystal displays, light leakage defects occur, which causes the problem of lower CR.

The problem of the present invention is to provide a method for improving light leakage and improving CR (Contrast Ratio) by controlling the transmittance of a backlight unit.

In order to achieve the above-described problem, the present invention includes a liquid crystal panel and a backlight unit below the liquid crystal panel, wherein the backlight unit includes a diffusion sheet, a first prism sheet below the diffusion sheet, and the diffusion sheet. It includes a transmission control film located on the top or between the diffusion sheet and the first prism sheet, wherein the transmission control film is dispersed in the first and second substrates and a transmission control layer between the first and second substrates and filled with liquid crystal molecules. A liquid crystal display device including a liquid crystal capsule is provided.

Here, the transmission control film may include a first electrode corresponding to each of a plurality of divided regions on the inner surface of the first substrate, and a second electrode corresponding to a plurality of divided regions on the inner surface of the second substrate. .

The transmission control film may include black dye contained in the transmission control layer and/or the liquid crystal capsule.

The refractive index difference of the liquid crystal molecules may be 0.2 or more.

It further includes a flexible circuit film connected to an edge of the transmission control film to transmit a driving voltage, and the electrode pad of the transmission control film connected to the output terminal of the flexible circuit film is made of adhesive resin in which conductive particles are dispersed. It can be.

It further includes a driving substrate that outputs a driving voltage, a flexible circuit film connecting the driving substrate and a transmission control film, a bottom cover located below the backlight unit and having an outlet, and a guide panel located outside the backlight unit. And, the flexible circuit film may extend downward along the inner side of the side wall of the guide panel, pass through the outlet, and extend to the lower back of the bottom cover.

A driving substrate that outputs a driving voltage, a flexible circuit film connecting the driving substrate and a transmission control film, a bottom cover located below the backlight unit, and a guide located outside the backlight unit and having an outlet on the side wall. It may further include a panel, and the flexible circuit film may pass through the outlet, extend downward along the outer side of the side wall of the guide panel, and extend to a lower rear surface of the bottom cover.

It may further include a second prism sheet located below the first prism sheet.

In the present invention, a transmission control film capable of controlling transmittance is applied to the backlight unit as an optical member, and in particular, the transmission control film is placed on the top or bottom of the diffusion sheet.

Accordingly, it is possible to improve CR while improving light leakage defects of the liquid crystal display device.

1 is a cross-sectional view schematically showing a conventional liquid crystal display device.
Figure 2 is a diagram showing light leakage in a conventional liquid crystal display device.
Figure 3 is a cross-sectional view schematically showing a liquid crystal display device according to an embodiment of the present invention.
Figure 4 is a view showing an example in which a transmission control film according to an embodiment of the present invention is disposed between a diffusion sheet and a prism sheet.
Figure 5 is a diagram showing light leakage improved in a liquid crystal display device according to an embodiment of the present invention.
Figure 6 is a cross-sectional view schematically showing an example of a transmission control film structure according to an embodiment of the present invention.
Figure 7 is a diagram schematically showing an example of operation for each region of the transmission control film according to an embodiment of the present invention.
Figure 8 is a diagram schematically showing an example in which black dye is added to the transmission control layer of a transmission control film according to an embodiment of the present invention.
Figure 9 is a diagram schematically showing a transmission control film, a driving substrate, and a flexible circuit film according to an embodiment of the present invention.
Figure 10 is a cross-sectional view schematically showing the connection portion between the transmission control film and the flexible circuit film according to an embodiment of the present invention.
Figure 11 is a rear view schematically showing the driving substrate disposed on the back of the bottom cover according to an embodiment of the present invention.
FIG. 12 is a cross-sectional view taken along line XII-XII of FIG. 11.
Figure 13 is a cross-sectional view schematically showing another example of the structure of a liquid crystal display device in which a driving substrate is disposed on the back of a bottom cover according to an embodiment of the present invention.
Figure 14 is a perspective view schematically showing a part of the guide panel in the liquid crystal display device structure of Figure 13.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Figure 3 is a cross-sectional view schematically showing a liquid crystal display device according to an embodiment of the present invention.

Referring to FIG. 3, the liquid crystal display device 100 according to an embodiment of the present invention includes a liquid crystal panel 110, a backlight unit 120, a guide panel 130, a top case 140, and a bottom cover 150. may include.

Here, the guide panel 130, top case 140, and bottom cover 150 correspond to structures for modularization by combining with the liquid crystal panel 110 and the backlight unit 120.

The guide panel 130 may be configured in the form of a frame surrounding the sides of the liquid crystal panel 110 and the backlight unit 120. The liquid crystal panel 110 may be seated on the guide panel 130. In this case, the liquid crystal panel 110 may be attached to the upper surface of the guide panel through an adhesive member such as double-sided adhesive tape.

The bottom cover 150 protects and supports the back of the backlight unit 120 surrounded by the guide panel 130. The bottom cover 150 may be configured to include a plate-shaped base on which the backlight unit 120 is seated and a side wall bent vertically upward from the edge of the base, and an internal receiving space defined by the base and the side wall. The backlight unit 120 can be accommodated.

The top case 140 may be configured to have a square frame shape covering the upper edge of the liquid crystal panel 110.

The liquid crystal panel 110 is a component that displays an image and includes first and second substrates 112 and 114 that are bonded when facing each other and a liquid crystal layer (not shown) sandwiched between the two substrates 112 and 114.

Although not specifically shown, pixels are defined by crossing a plurality of gate wires and data wires on the inner surface of the first substrate 112, called the lower substrate or array substrate, and each pixel has a thin film transistor connected to the corresponding gate wire and data wire. A pixel electrode connected to a thin film transistor can be formed.

And, on the inner surface of the second substrate 114, which is an opposing substrate facing the first substrate 112 and is called an upper substrate or color filter substrate, a color filter pattern corresponding to each pixel is formed, and a gate wiring and a gate wiring are formed around the color filter pattern. A black matrix can be formed that covers non-display elements such as data wiring and thin film transistors.

At this time, any type of liquid crystal panel can be used as the liquid crystal panel 110. For example, any type of liquid crystal panel such as IPS type, AH-IPS type, TN type, VA type, or ECB type can be used. Here, both the AH-IPS method and the IPS method are methods that use a horizontal electric field and are included in the horizontal electric field method. In this horizontal electric field method, the first substrate 112 includes a common electrode that forms a horizontal electric field together with the pixel electrode. This can be formed.

In addition, an alignment film may be formed at the interface between the first and second substrates 112 and 114 and the liquid crystal layer to determine the initial molecular arrangement direction of the liquid crystal, and to prevent leakage of the liquid crystal layer filled between the first and second substrates 112 and 114. For this purpose, a seal pattern may be formed along the edges of the two substrates 112 and 114.

Additionally, a polarizing plate that selectively transmits specific polarized light may be attached to the outer surface of the first substrate 112 or the second substrate 114.

In addition, although not shown, a printed circuit board is connected along at least one edge of the liquid crystal panel 110 via a flexible circuit film such as a tape carrier package, and is configured to be bent and adhered to the back of the bottom cover 150 during the modularization process. It can be.

The backlight unit 120 may include an LED assembly 129, a reflector 121, a light guide plate 123, a plurality of optical sheets 125, and a transmission control film 200.

The LED assembly 129 may include a PCB (129b) and a plurality of LEDs (129a) mounted on the upper surface of the PCB (129b), and the plurality of LEDs (129a) are mounted in the longitudinal direction of the PCB (129b). It can be arranged at regular intervals along the line.

The light guide plate 123 is arranged so that one side of the light receiving surface faces the LED 129a. The light incident from the LED 129a travels within the light guide plate 123 through multiple total reflections and is uniformly spread over a wide area of the light guide plate 123, thereby providing a uniform surface light source.

A reflector 121 may be provided under the light guide plate 123 in close contact with the bottom surface, which is the upper surface of the base of the bottom cover 150. The reflector 121 may be white or silver in color for reflective properties. In this way, the reflector 121 is located behind the light guide plate 123, and serves to reflect light passing through the back of the light guide plate 123 toward the top toward the liquid crystal panel 110, thereby improving brightness.

A plurality of optical sheets 125 may be disposed on the upper part of the light guide plate 123 as optical members to provide higher quality light to the liquid crystal panel 110 by concentrating and diffusing the light emitted from the light guide plate 123. .

For example, the plurality of optical sheets 125 may include at least one prism sheet (PS1, PS2) as a light collection member and a diffusion sheet (DS) as a diffusion member. Here, in this embodiment, the case where two first and second prism sheets (PS1 and PS2) are used is taken as an example. In this case, the first prism sheet PS1 located at the top and the second prism sheet PS2 located at the bottom are arranged so that the prism patterns, which are light condensing patterns, are orthogonal to each other.

Meanwhile, in this embodiment, the diffusion sheet DS is configured to be located above the prism sheets PS1 and PS2. That is, the diffusion sheet DS is disposed closer to the liquid crystal panel 110 than the prism sheets PS1 and PS2.

In particular, the backlight unit 120 of this embodiment is provided with a transmission control film 200 including liquid crystal to adjust the transmittance of the backlight unit 120.

The transmission control film 200 is operated to switch the on/off state, and may be configured to adjust the transmittance depending on the on/off state. In this regard, for example, when in the on state, the transmission control film 200 may have relatively high transmittance characteristics, and when in the off state, the transmission control film 200 may have relatively low transmittance characteristics. Of course, on the contrary, it may be configured to have low transmittance in the on state and high transmittance in the off state. In this embodiment, the case where the transmission control film 200 operates to have a relatively high transmittance in the on state is taken as an example.

In this way, the transmittance of light emitted from the backlight unit 120 to the upper liquid crystal panel 110 can be adjusted by adjusting the transmittance using the transmission control film 200. Accordingly, it is possible to improve light leakage and improve CR.

In this regard, for example, when the liquid crystal panel 110 displays white, the transmission control film 200 is operated in the on state to implement a white state, and when displaying black, the transmission control film 200 is operated in the on state. By operating the control film 200 in an off state, the transmittance is reduced to implement a black state.

Due to this transmittance control operation, the transmittance of the backlight unit 120 in the black state is lowered, thereby reducing the luminance in the black state. Accordingly, light leakage from the edge of the liquid crystal panel 110 is reduced, thereby improving light leakage defects and improving CR. Here, FIG. 5 can be referred to in relation to the improvement of light leakage defects in this embodiment. It can be seen that light leakage defects at the edges of the liquid crystal panel, especially the corners, are improved compared to the conventional FIG. 2.

The transmission control film 200 with such characteristics will be described in more detail below.

According to this embodiment, in order to secure sufficient transmittance and CR for driving the liquid crystal display device 100, the transmission control film 200 implemented using liquid crystal is preferably disposed on the prism sheets PS1 and PS2. . That is, the transmittance control film 200 is disposed on the diffusion sheet DS as shown in FIG. 3, or the transmission control film 200 is placed between the diffusion sheet DS and the first prism sheet PS1 as shown in FIG. 4. It is desirable for the film 200 to be disposed. Regarding this, please refer to [Table 1] below. [Table 1] shows the experimental results for white luminance and CR in the arrangement structures of the conventional and present examples (Examples 1 and 2) and Comparative Examples 1 and 2. there is.

division conventional Example (Example 1) Example (Example 2) Comparative Example 1 Comparative example 2 layout structure
- Transmission control film DS DS DS DS DS Transmission control film PS1 PS1 PS1 PS1 PS1 Transmission control film PS2 PS2 PS2 PS2 PS2 Transmission control film white luminance 100.0% 86.3% 82.8% 68.6% 61.8% CR 1,701 2,900 2,800 2,000 1,818

Referring to [Table 1], in the case of PS2/PS1/DS in the upper direction (i.e., towards the liquid crystal panel 110) as a conventional arrangement structure, the white luminance is 100.0%, which is the standard value, and CR is 1,701.

Meanwhile, in the case of the PS2/PS1/DS/transmission control film 200 in the upper direction as the arrangement structure of the first example of this embodiment, the white luminance is 86.3% and CR is 2,900. And, in the case of the arrangement structure of the second example of this embodiment, PS2/PS1/transmission control film 200/DS in the upward direction, the white luminance is 82.8% and CR is 2,800. As such, in the case of this embodiment, the luminance is somewhat reduced compared to the prior art, but this is within an acceptable level for a display device, and CR can be secured at a very high level compared to the prior art.

In comparison, in the case of the arrangement structure of Comparative Example 1 of PS2/transmission control film (200)/PS1/DS toward the top, the white luminance is 68.6% and CR is 2,000. And, in the case of the arrangement structure of Comparative Example 2, where the transmission control film 200/PS2/PS1/DS is directed upward, the white luminance is 61.8% and CR is 1,818. As such, in the case of the comparative example, the luminance is at an unacceptable level as a display device, which is very low compared to the present embodiment, and CR is also at a very low level compared to the present embodiment.

In this way, as in the present embodiment, the transmission control film 200 is disposed on the prism sheets (PS1 and PS2), that is, the transmission control film 200 is closer to the liquid crystal panel 110 than the prism sheets (PS1 and PS2). By placing them close together, it is possible to achieve a high level of CR while securing sufficient luminance for video display.

Hereinafter, the structure of the transmission control film 200 of this embodiment will be described in detail with reference to FIGS. 6 and 7. Figure 6 is a cross-sectional view schematically showing an example of the structure of a transmission control film according to an embodiment of the present invention, and Figure 7 is a diagram schematically showing an example of operation in each region of the transmission control film according to an embodiment of the present invention. .

The transmission control film 200 includes first and second substrates 201 and 202 located at the lower and upper sides facing each other, and a transmission control layer 220 containing liquid crystal molecules 223 between the first and second substrates 201 and 202. and first and second electrodes 211 and 212 respectively formed on the inner surfaces of the first and second substrates 201 and 202 to form an electric field for driving the liquid crystal molecules 223.

The first and second substrates 201 and 202 may be formed of a polymer material such as PET or PC, but are not limited thereto. Additionally, the first and second electrodes 211 and 212 may be formed of a transparent conductive material, but are not limited thereto.

The transmission control layer 220 between the first and second substrates 201 and 202 may be composed of, for example, a polymer layer, but is not limited thereto. Inside this transmission control layer 200, a plurality of liquid crystal capsules 222 may be dispersed and contained, and the interior of each liquid crystal capsule 222 may be filled with liquid crystal molecules 223. At this time, the liquid crystal molecules 223 in the liquid crystal capsule 222, for example, have a random arrangement in the off state where an electric field is not applied, and are arranged along the vertical electric field direction in the on state where an electric field is applied. state, and the transmittance may be reduced in a random arrangement state in the off state.

At this time, the transmission control film 200 of this embodiment may be configured to be divided and driven for each region. For example, the transmission control film 200 defines a plurality of divided areas (DA) arranged in a matrix form, and the divided areas Transmittance can be individually adjusted in (DA) units.

For such individual driving in units of division areas (DA), for example, the first electrode 211 formed on the first substrate 201 may be configured to be patterned in units of division areas (DA), The second electrode 212 formed on the second substrate 202 may be configured as a single common electrode corresponding to all divided areas DA. Of course, on the contrary, the second electrode 212 formed on the second substrate 202, which is the upper substrate, may be formed to correspond to each of the division areas DA, and the first electrode 211 formed on the first substrate 201 ) may be configured to correspond to all partition areas DA.

In this way, when the first electrode 211 is formed in units of division areas (DA), the second driving voltage, which is a common voltage, can be applied to the second electrode 212. At this time, when the second driving voltage equal to the second driving voltage is applied to the first electrode 211, an electric field is not generated in the corresponding division area DA, so it is in an off state and the transmittance is reduced. On the other hand, when a first driving voltage different from the second driving voltage is applied to the first electrode 211, an electric field due to the voltage difference is generated in the corresponding division area DA, and the transmittance is not reduced.

In this way, by adjusting the driving voltage applied to the first electrode 211 individually in each division area (DA), the transmittance can be adjusted in each division area (DA), thereby implementing a local dimming operation. There will be. That is, when displaying an image displayed on the liquid crystal panel 110, the effect of adjusting the brightness of the image for each area can be implemented, and the CR improvement effect can be maximized.

Meanwhile, the liquid crystal used in the transmission control film 200 of this embodiment may be, for example, a nematic liquid crystal. In this case, the liquid crystal has a refractive index difference (i.e., the difference between the abnormal refractive index and the normal refractive index) (Δn). It is preferable that is 0.2 or more. In relation to this, when the refractive index difference is less than 0.2, the scattering phenomenon increases and light emission in the upward direction decreases, thereby lowering the transmittance. Therefore, it is desirable to use liquid crystal with a refractive index difference of 0.2 or more to prevent decrease in transmittance.

Also, the size of the capsule 222 may be, for example, approximately 1um to 2um, but is not limited thereto.

Meanwhile, in order to further improve CR, black dye may be added to the transmission control layer 220, for which reference may be made to FIG. 8. Figure 8 is a cross-sectional view schematically showing an example in which black dye is added to the transmission control layer of a transmission control film according to an embodiment of the present invention.

Referring to FIG. 8, the black dye 225 is dispersed throughout the transmission control layer 220. Meanwhile, as another example, the black dye 225 may be contained together with the liquid crystal molecules 223 in the liquid crystal capsule 222, or may be configured to be contained in both the transmission control layer 220 and the liquid crystal capsule 222.

In this way, as the black dye 225 is added, the luminance in the black state can be further lowered, and light leakage can be further improved and CR can be further improved. In this regard, refer to [Table 2], which shows the experimental results for white luminance and CR in the case where black dye was added and when black dye was not added in this example. Here, the arrangement structure of this example used in the experiment is that of PS2/PS1/DS/transmission control film.

division conventional Example (without black dye) Example (black dye application) layout structure
- Transmission control film Transmission control film DS DS DS PS1 PS1 PS1 PS2 PS2 PS2 white luminance 100.0% 86.3% 82.8% CR 1,701 2,900 3,100

Referring to [Table 2], it can be seen that in this embodiment, when the transmission control film 200 to which the black dye 225 is not applied is used, CR is approximately 2,900.

Meanwhile, in this embodiment, when the transmission control film 200 to which black dye 225 is applied is used, it can be seen that CR is 3,100. In this way, when the transmission control film 200 to which the black dye 225 is applied is used, a higher level of CR can be secured.

In addition, when the transmission control film 200 to which the black dye 225 is applied is used, the white luminance becomes approximately 82.8%, which is an acceptable level for a display device.

Therefore, when the transmission control film 200 containing the black dye 225 is used, a higher level of CR can be achieved while securing sufficient luminance.

Meanwhile, the transmission control film 200 of this embodiment may be formed as an integrated structure with the optical sheet 125 located below or above.

Meanwhile, the liquid crystal display device 100 of this embodiment may further include components for applying a driving voltage to the transmission control film 200, which will be described in more detail below with reference to FIGS. 9 and 10. . Figure 9 is a diagram schematically showing a transmission control film, a driving substrate, and a flexible circuit film according to an embodiment of the present invention, and Figure 10 is a schematic diagram showing the connection portion of the transmission control film and the flexible circuit film according to an embodiment of the present invention. It is a cross-sectional view shown as .

The transmission control film 200 receives the driving voltage output from the driving substrate 260 through the flexible circuit film 250.

On the inner surface, that is, the upper surface, of the first substrate 201 of the transmission control film 200, a plurality of electrode pads 215 may be formed on at least one edge of one side, and each electrode pad 215 has a corresponding first electrode 211. ) and may be configured to be electrically connected to transmit the corresponding driving voltage (i.e., first driving voltage). Meanwhile, at least one of the plurality of electrode pads 215 formed on the first substrate 201 is electrically connected to the second electrode 212 and serves as an electrode pad for applying the corresponding driving voltage (i.e., the second driving voltage). can be used

Here, in this embodiment, an example is taken where the electrode pads 215 are formed on the edges of the three sides (i.e., the upper side, left side, and right side in the drawing) of the first substrate 201.

One end of the flexible circuit film 250 that transmits the driving voltage is connected to the side edge of the first substrate 201 where the electrode pad 215 is formed. Here, at least one flexible circuit film 250 may be disposed on each side of the first substrate 201 where the electrode pads 215 are arranged. In this embodiment, a case where multiple, that is, two flexible circuit films 250 are disposed on the upper side, and one flexible circuit film 250 is disposed on each of the left and right sides is taken as an example.

Output terminals connected to each of the electrode pads 215 are formed on one end of the flexible circuit film 250 (i.e., the attachment surface to the first substrate 201), and the corresponding driving voltage is supplied through the output terminals. It may be applied to the corresponding electrode pad 215.

A driving board 260 that supplies driving voltage is connected to the other end of the flexible circuit film 250. The driving voltage output from the driving substrate 260 is supplied to the transmission control film 200 through the flexible circuit film 250, so that the transmittance of the transmission control film 200 can be adjusted.

Meanwhile, with reference to FIG. 10 , the electrode pad 215 of this embodiment may be formed using, for example, an adhesive resin in which conductive particles 215a are dispersed, but is not limited thereto. In this way, when the electrode pad 215 is formed with adhesive resin in which the conductive particles 215a are dispersed, the flexible circuit film 250 is directly applied to the electrode pad 215 without using a separate adhesive conductor such as ACF as a medium. ), the attachment process between the flexible circuit film 250 and the transmission control film 200 can be simplified and connection reliability can be improved.

Meanwhile, the driving substrate 260 connected to the transmission control film 200 through the flexible circuit film 250 may be configured to be bent and adhered to the back of the bottom cover 150 during the modularization process. In this regard, Figures 11 and 12 It is explained with reference to . FIG. 11 is a diagram schematically showing the driving substrate disposed on the back of the bottom cover according to an embodiment of the present invention and is a view showing the back of the liquid crystal display device, and FIG. 12 is a view taken along the cutting line XII- of FIG. 11. This is a cross-sectional view along line XII.

In order to place the driving board 260 on the back of the bottom cover 150, the flexible circuit film 250 is in a bent state and extends inside the side and lower back of the liquid crystal display device 100. You can have it.

For example, the flexible circuit film 250 extends downward along the inner surface of the side wall 131 of the guide panel 130 and is then bent inward to form a bending structure extending along the back of the bottom cover 150. may have, and accordingly, the driving substrate 260 connected to the other end of the flexible circuit film 250 may be disposed on the back of the bottom cover 150.

At this time, the bottom cover 150 may be provided with an outlet 155 so that the flexible circuit film 250 can be drawn out downward. The flexible circuit film 250 is drawn out below the edge of the bottom cover 150 through this outlet 155 and is then bent inward to have a structure that extends along the back of the bottom cover 150. In this way, the outlet 155 is formed in the bottom cover 150 so that the flexible circuit film 250 can pass through the outlet 155 and extend to the bottom of the back of the bottom cover 150, so that the liquid crystal display device 100 ) The driving substrate 260 can be effectively placed on the back of the bottom cover 150 without complicating the structure and without increasing the bezel width.

Meanwhile, referring to FIGS. 13 and 14 as an example different from the above, an outlet 135 through which the flexible circuit film 250 is output may be formed at the top of the side wall 131 of the guide panel 130. In this case, the flexible circuit film 250 passes through the outlet 135 of the guide panel 130 and is bent downward to form the guide panel 130 between the side wall of the guide panel 130 and the side wall of the top case 140. ) may be configured to extend along the outer surface of the side wall 131 and then be bent inward to extend to the lower back of the bottom cover 150. In this case, the driving substrate 260 can be effectively disposed on the back of the bottom cover 150 without complexly changing the structure of the liquid crystal display device 100 and without increasing the thickness.

As described above, according to an embodiment of the present invention, a transmission control film capable of adjusting transmittance is applied to the backlight unit as an optical member, and in particular, the transmission control film is disposed on the top or bottom of the diffusion sheet.

Accordingly, it is possible to improve CR while improving light leakage defects of the liquid crystal display device.

The above-described embodiment of the present invention is an example of the present invention, and free modification is possible within the scope included in the spirit of the present invention. Accordingly, the present invention includes modifications of the present invention within the scope of the appended claims and their equivalents.

100: liquid crystal display device 110: liquid crystal panel
112: first substrate 114: second substrate
120: backlight unit 121: reflector
123: light guide plate 125: optical sheet
129: LED assembly 129a: LED
129b: PCB 130: Guide panel
135: Guide panel outlet 140: Top case
150: Bottom cover 155: Bottom cover outlet
200: Transmission control film 201: First substrate
202: second substrate 211: first electrode
212: second electrode 215: electrode pad
215a: Conductive particle 220: Transmission control layer
222: liquid crystal capsule 223: liquid crystal molecule
225: Black dye 250: Flexible circuit film
260: Driving board
DS: diffusion sheet
PS1, PS2: Prism sheet

Claims (9)

a liquid crystal panel;
It includes a backlight unit below the liquid crystal panel,
The backlight unit is,
a diffusion sheet;
a first prism sheet below the diffusion sheet;
a second prism sheet below the first prism sheet;
a light guide plate below the second prism sheet;
It includes a transmission control film located on top of the diffusion sheet or between the diffusion sheet and the first prism sheet,
The transmission control film includes first and second substrates and liquid crystal capsules dispersed in a transmission control layer between the first and second substrates and filled with liquid crystal molecules.
Liquid crystal display device.
According to claim 1,
The transmission control film is,
a first electrode corresponding to each of a plurality of divided regions on the inner surface of the first substrate;
Comprising a second electrode corresponding to a plurality of divided regions on the inner surface of the second substrate
Liquid crystal display device.
According to claim 1,
The transmission control film includes black dye contained in the transmission control layer and/or the liquid crystal capsule.
Liquid crystal display device.
According to claim 1,
The refractive index difference of the liquid crystal molecules is 0.2 or more.
Liquid crystal display device.
According to claim 1,
It further includes a flexible circuit film connected to an edge of the transmission control film to transmit a driving voltage,
The electrode pad of the transmission control film connected to the output terminal of the flexible circuit film is composed of adhesive resin in which conductive particles are dispersed.
Liquid crystal display device.

According to claim 1,
a driving board that outputs a driving voltage;
a flexible circuit film connecting the driving substrate and a transmission control film;
a bottom cover located below the backlight unit and having an outlet;
Further comprising a guide panel located outside the backlight unit,
The flexible circuit film extends downward along the inner side of the side wall of the guide panel, passes through the outlet, and extends to the lower back of the bottom cover.
Liquid crystal display device.
According to claim 1,
a driving board that outputs a driving voltage;
a flexible circuit film connecting the driving substrate and a transmission control film;
a bottom cover located below the backlight unit;
It is located outside the backlight unit and further includes a guide panel having an outlet on a side wall,
The flexible circuit film passes through the outlet, extends downward along the outer side of the side wall of the guide panel, and extends to the lower back of the bottom cover.
Liquid crystal display device. delete According to claim 2,
The second electrode is formed in the form of a single electrode corresponding to the entire plurality of divided regions.
Liquid crystal display device.
.

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