KR102334856B1 - Liquid display device - Google Patents

Abstract

The present invention relates to a liquid crystal display having a privacy protection function, wherein the liquid crystal display according to the present invention has a backlight unit positioned to face a light guide plate having a plurality of condensing lenses on the side thereof, and the plurality of condensing lenses, and the privacy protection mode and a plurality of light sources selectively lit according to the general mode.

Description

Liquid crystal display device {LIQUID DISPLAY DEVICE}

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having a privacy protection function.

Recently, interest in information display has increased, and there is a growing demand for using a portable information medium. Accordingly, research and commercialization of a lightweight thin-film flat panel display (FPD) that replaces a cathode ray tube (CRT), which is an existing display device, is being focused on.

Flat panel displays include Liquid Crystal Display (LCD), Field Emission Display (FED), Plasma Display Panel (PDP), Organic Light Emitting Display (OLED). ), an electrophoresis display device (EPD), and the like.

Products for protecting personal privacy are being developed in such flat panel display devices. For example, devices such as ATMs in financial institutions, laptops, and tablet PCs require a narrow viewing angle in the left and right or up and down directions to protect privacy. Conventionally known narrow viewing angle technology includes a method of attaching a viewing angle control film, and a method further comprising a viewing angle control panel.

The method of attaching the viewing angle control film was first developed by 3M, and is a method of attaching a privacy protection substrate that forms a narrow viewing angle to the front surface of the liquid crystal panel. The privacy protection substrate forms a louver layer between double skin layers made of polycarbonate material, and blocks light incident from a specific angle by controlling the spacing and height of the partition walls. to control

The method of further including the viewing angle panel is a method of disposing the liquid crystal panel for viewing angle control on the front side separately from the liquid crystal panel on which an image is displayed. The liquid crystal panel for viewing angle control realizes a wide viewing angle and a narrow viewing angle by varying the movement of the liquid crystal layer.

However, the conventional narrow viewing angle technology as described above has the following problems.

First, the method of attaching the viewing angle control film is expensive due to 3M's exclusive production. In addition, there is a hassle of manually attaching and detaching the viewing angle control film to the liquid crystal panel.

Second, since the method of further including the viewing angle panel includes a liquid crystal panel for viewing angle control separately from the liquid crystal panel, there is a problem in that the structure is complicated and power consumption is increased.

The present invention has been devised to solve the above problems, and it is a technical task to provide a liquid crystal display device that provides a privacy protection function, reduces costs, and has a simple structure.

In addition to the technical problems of the present invention mentioned above, other features and advantages of the present invention will be described below, or will be clearly understood by those of ordinary skill in the art from such description and description.

A liquid crystal display device according to the present invention for achieving the above technical problem is a backlight unit positioned to face a light guide plate provided with a plurality of condensing lenses on a side thereof, and the plurality of condensing lenses, and is selectively selected according to the privacy protection mode and the general mode It may be provided with a plurality of light sources that are turned on.

According to the means for solving the above problems, the present invention has the following effects.

The present invention provides a privacy protection mode or Implement normal mode. The present invention can reduce costs compared to a method of attaching a viewing angle control film for privacy protection. In addition, there is an advantage in that power consumption is reduced because the structure is simple in switching between the privacy protection function and the normal mode and there is no luminance loss due to the viewing angle control film.

In addition to the effects of the present invention mentioned above, other features and advantages of the present invention will be described below or will be clearly understood by those of ordinary skill in the art from such description and description.

1 is a block diagram of a liquid crystal display according to an embodiment of the present invention.
2 is a conceptual diagram for explaining the privacy protection mode of the present invention.
3 is a conceptual diagram for explaining a general mode of the present invention.
4 is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.
5A and 5B are cross-sectional views for explaining the operation of the backlight unit in the privacy protection mode and the normal mode.
6 is a perspective view illustrating a backlight unit according to an embodiment of the present invention.
FIG. 7 is a plan view illustrating the backlight unit shown in FIG. 6 .
8 is a cross-sectional view of a liquid crystal display device according to another exemplary embodiment.
9 is a conceptual diagram illustrating a privacy protection mode in a state in which the light collecting sheet 360 is not applied.
10 is a conceptual diagram illustrating a privacy protection mode in a state in which the light collecting sheet 360 is applied.

The meaning of the terms described in this specification should be understood as follows. The singular expression is to be understood as including the plural expression unless the context clearly defines otherwise, and the terms "first", "second", etc. are used to distinguish one element from another, The scope of rights should not be limited by these terms. It should be understood that terms such as “comprise” or “have” do not preclude the possibility of addition or existence of one or more other features or numbers, steps, operations, components, parts, or combinations thereof. The term “at least one” should be understood to include all possible combinations from one or more related items. For example, the meaning of “at least one of the first, second, and third items” means that each of the first, second, or third items as well as two of the first, second and third items It means a combination of all items that can be presented from more than one. The term “on” is meant to include not only cases in which a certain component is formed directly on top of another component, but also a case in which a third component is interposed between these components.

Hereinafter, a preferred example of a liquid crystal display according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a liquid crystal display according to an embodiment of the present invention. 2 is a conceptual diagram for explaining the privacy protection mode of the present invention. 3 is a conceptual diagram for explaining a general mode of the present invention.

Referring to FIG. 1 , a liquid crystal display according to an embodiment of the present invention includes a liquid crystal panel 100 for displaying an image, a panel driver 200 for driving the liquid crystal panel 100 , and a liquid crystal panel 100 . It includes a backlight unit 300 for supplying light and a light source driver 400 for driving the backlight unit 300 .

The liquid crystal panel 100 is driven in any one selected from the privacy protection mode and the normal mode according to the characteristics of the light provided by the backlight unit 300 .

Referring to FIG. 2 , in the privacy protection mode, the backlight unit 300 irradiates straight light having a direction perpendicular to the rear surface of the liquid crystal panel 100 to the rear surface of the liquid crystal panel 100 . Accordingly, in the privacy protection mode, only the user who looks at the display panel of the liquid crystal display device, that is, the liquid crystal panel 100 from the front, can view the privacy image, and the user who looks at the liquid crystal panel 100 from the left or right side sees the black image. Or you see a noisy image. Here, the privacy image refers to an image that a user wants to keep from being seen by others for security or privacy protection.

Referring to FIG. 3 , in the normal mode, the backlight unit 300 irradiates the diffused light radially diffused onto the rear surface of the liquid crystal panel 100 . Accordingly, in the normal mode, the user can view the image regardless of the position (angle) from which the liquid crystal panel 100 is viewed. This general mode corresponds to a wide viewing angle mode as a general situation in which an image is displayed.

The liquid crystal panel 100 can be applied regardless of Twisted Nematic (TN), In Plane Switching (IPS), and Vertical Alignment (VA) modes.

A plurality of pixels P constituting the liquid crystal panel 100 are arranged in a matrix form forming rows and columns, and each pixel has one selected from among red (R), green (G), and blue (B) colors. has A pixel according to another embodiment of the present invention may have one selected from red (R), green (G), blue (B), and white (W) colors.

The panel driver 200 includes a gate driver 210 , a data driver 220 , a timing controller 230 , and a gamma voltage generator for respectively driving the gate line GL and the data line DL of the liquid crystal panel 100 . (240) and the like.

The gate driver 210 sequentially supplies a scan signal to the gate line GL according to a gate control signal supplied from the timing controller 230 .

The data driver 220 converts pixel data (gray level) input from the timing controller 230 through the signal converter 250 into an image signal in response to a data control signal supplied from the timing controller 230 . In addition, the data driver 220 supplies the converted image signal to the data line DL.

Here, the image signal is a gamma voltage selected from among the gamma voltages supplied from the gamma voltage generator 240 to correspond to red, green, and blue pixel data input from the outside.

The timing controller 230 outputs red, green, and blue pixel data input from the outside, and uses vertical and horizontal synchronization signals (Vsync, Hsync), a clock, etc. A gate control signal and a data control signal for controlling driving timing, respectively, are generated.

The timing controller 230 generates a backlight control signal in synchronization with driving timings of the gate driver 210 and the data driver 220 . The backlight control signal is for controlling the timing at which the light source driver 400 drives the backlight unit 300 .

The gamma voltage generator 240 generates gamma voltages necessary for digital/analog conversion of the data driver 220 within a grayscale range and supplies them to the data driver 220 .

The backlight unit 300 is configured in an edge-type manner. In the edge-type backlight unit 300 , the light guide plate 310 is provided under the liquid crystal panel 100 , and the light source is disposed to face the side surface of the light guide plate 310 . In the following embodiments, it is assumed that the light source is an LED array. However, the light source of the present invention is not limited to the LED array.

In particular, the backlight unit 300 according to an embodiment of the present invention selectively switches an operation of irradiating a straight light to the liquid crystal panel 100 and an operation of irradiating diffused light to the liquid crystal panel 100 , thereby providing a privacy protection mode and a general mode. makes conversion possible.

The light source driver 400 drives the backlight unit 300 in response to a backlight control signal supplied from the timing controller 230 . The light source driver 400 selectively drives the backlight unit 300 in synchronization with the mode selection of the panel driver 200 . That is, switching between the operation of the backlight unit 300 irradiating the straight light to the liquid crystal panel 100 and the operation of irradiating the diffused light to the liquid crystal panel 100 may be controlled by the timing controller 230 .

4 is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention. 5A and 5B are cross-sectional views for explaining the operation of the backlight unit in the privacy protection mode and the normal mode. Specifically, FIG. 5A describes the operation of the backlight unit in the privacy protection mode. And FIG. 5B describes the operation of the backlight unit in the normal mode.

Hereinafter, the configuration of the liquid crystal display device of the present invention will be described in more detail with reference to FIGS. 1 and 4 .

The liquid crystal panel 100 includes an upper substrate 101 , a lower substrate 102 , an upper polarizing member 103 disposed on the upper substrate 101 , and a lower polarizing member 104 disposed under the lower substrate 102 . ), and a liquid crystal layer filled between the upper and lower substrates 102 .

The upper substrate 101 may include a color filter, a common electrode, a black matrix, and the like. The common electrode may be disposed on the lower substrate 102 according to the liquid crystal driving method of the liquid crystal panel 100 . The upper substrate 101 converts light incident through the liquid crystal layer into a predetermined color light using a color filter, and emits the converted color light to the outside.

Signal lines such as a plurality of gate lines GL and a plurality of data lines DL are formed on the lower substrate 102 . A thin film transistor TFT is formed at the intersection of the gate line GL and the data line DL, and the thin film transistor TFT is connected to a pixel electrode disposed in each pixel. The pixel electrode applies an electric field to the liquid crystal layer together with the common electrode to which a common voltage is supplied. The thin film transistor TFT supplies the image signal provided from the data line DL to the pixel electrode in response to the scan signal provided from the gate line GL. The liquid crystal layer adjusts light transmittance in response to a difference voltage between a data voltage according to an image signal applied to the pixel electrode and a common voltage applied to the common electrode.

A pad portion connected to each signal line may be provided on one edge of the lower substrate 102 , and a printed circuit board connected to the driver may be bonded to the pad portion. A gate driver 210 for supplying a scan signal to the gate line GL may be formed in a non-display area of one short side or both short sides of the lower substrate 102 . The gate driver 210 is formed in the same process as the thin film transistor TFT of each pixel to be connected to each gate line GL.

The upper polarizing member 103 may be formed of a polarizing film that is attached to the upper portion of the upper substrate 101 and polarizes color light emitted to the outside through the upper substrate 101 .

On the other hand, the upper polarizing member 103 according to another embodiment is attached to the upper surface of the upper substrate 101 and passes through the upper substrate 101 to polarize the color light emitted to the outside, and on the upper surface of the upper polarizing film. It may be configured to include a retarder film that is attached and separates a 3D image displayed on the display panel 100 , that is, a left-eye image and a right-eye image into different polarization states.

The lower polarizing member 104 may be formed of a polarizing film attached to the lower portion of the lower substrate 102 to polarize light irradiated from the backlight unit 300 to the liquid crystal panel 100 .

The backlight unit 300 includes a light guide plate 310 , a plurality of light sources 320 and 330 provided on one side of the light guide plate 310 , and a reflective sheet 340 disposed under the light guide plate 310 .

The light guide plate 310 guides the light provided from the plurality of light sources 320 and 330 and emits the light to the upper surface. A reflective pattern (not shown) is provided under the light guide plate 310 . The reflective pattern may be configured as a prism pattern that reflects the light entering the interior of the light guide plate 310 to the upper surface.

The light guide plate 310 of the present invention is provided with a plurality of condensing lenses 350 on the side surface. The plurality of condensing lenses 350 condense the light emitted from the plurality of first light sources 320 lit in the privacy protection mode, and the light incident into the light guide plate 310 in a direction perpendicular to the side surface of the light guide plate 310 . to have The plurality of condensing lenses 350 will be described in detail later with reference to FIGS. 6 and 7 .

The plurality of light sources 320 and 330 are positioned to face the condensing lens 350 provided on the side surface of the light guide plate 310 . The plurality of light sources 320 and 330 are selectively turned on according to the privacy protection mode and the general mode.

Specifically, the plurality of light sources 320 and 330 are a plurality of first light sources 320 that are turned on in the privacy protection mode and turned off in the general mode, and a plurality of second light sources 320 that are turned on in the general mode and turned off in the privacy protection mode ( 330).

The plurality of light sources 320 and 330 may be configured as an LED array, and the first and second light sources 320 and 330 may be configured with LEDs.

Although the first and second light sources 320 and 330 have the same structure and performance, types are distinguished depending on where they are located with respect to the condensing lens 350 provided on the side surface of the light guide plate 310 . This will be described in detail with reference to FIGS. 6 and 7 .

However, in FIGS. 4 and 5A and 5B , the first light source 320 is illustrated on one side of the light guide plate 310 and the second light source 330 is illustrated on the other side of the light guide plate 310 for conceptual explanation. However, in reality, the first and second light sources 310 and 320 of the present invention are alternately disposed on one side of the light guide plate 310 as shown in FIG. 6 . Therefore, in understanding the present invention, it should be noted that the first and second light sources 310 and 320 are not disposed on different sides of the light guide plate 310 .

Referring to FIG. 5A , the plurality of first light sources 320 are turned on in the privacy protection mode to irradiate light to the side surface of the light guide plate 310 . In this case, the light emitted from the first light source 320 is refracted by the condensing lens 350 provided on the side surface of the light guide plate 310 and is incident into the light guide plate 310 . At this time, the light incident into the light guide plate 310 is straight light and has a direction perpendicular to the side surface of the light guide plate 310 . The straight light incident into the light guide plate 310 is emitted to the upper portion of the light guide plate 310 by a reflective pattern provided under the light guide plate 310 . The light emitted to the upper portion of the light guide plate 310 is straight light and has a direction perpendicular to the rear surface of the liquid crystal panel 100 .

As described above, when the straight light perpendicular to the rear surface of the liquid crystal panel 100 is supplied to the liquid crystal panel 100 through the upper surface of the light guide plate 310 , the image displayed from the liquid crystal panel 100 has a narrow viewing angle. Thus, the privacy protection function is implemented.

Referring to FIG. 5B , the plurality of second light sources 330 are turned on in the normal mode to irradiate light to the side surface of the light guide plate 310 . In this case, the light emitted from the second light source 330 is refracted by the condensing lens 350 provided on the side surface of the light guide plate 310 and is incident into the light guide plate 310 . In this case, the light incident into the light guide plate 310 is diffused light and has a radial shape. The diffused light incident into the light guide plate 310 is emitted to the upper portion of the light guide plate 310 by a reflective pattern provided under the light guide plate 310 . Light emitted to the upper portion of the light guide plate 310 is supplied to the rear surface of the liquid crystal panel 100 as diffused light.

As such, when the diffused light radially diffused to the rear surface of the liquid crystal panel 100 toward the upper surface of the light guide plate 310 is supplied to the liquid crystal panel 100 , the image displayed from the liquid crystal panel 100 has a wide viewing angle. Accordingly, a normal mode for displaying a general image is implemented.

Meanwhile, the reflective sheet 340 is disposed under the light guide plate 310 to reflect light directed downward from the light guide plate 310 . The reflective sheet 340 serves to improve light efficiency.

6 is a perspective view illustrating a backlight unit according to an embodiment of the present invention. FIG. 7 is a plan view illustrating the backlight unit shown in FIG. 6 .

6 and 7 , a plurality of condensing lenses 350 are repeatedly formed on the side surface of the light guide plate 310 .

Each of the plurality of condensing lenses 350 is configured as a single unit with the light guide plate 310 and includes a plurality of first prism mounts protruding from the side surface of the light guide plate 310 . The plurality of first prism mountains protrude in the form of a Fresnel lens. Specifically, each of the plurality of first prism mountains has a shape inclined toward the center. In addition, the angle of the first prism mountain has a form in which the slope gradually decreases from both sides toward the center. Accordingly, among the plurality of first prism mountains, the slope of the first prism mountain located at both ends is the largest, and the slope of the first prism mountain located at the center is the smallest or no slope.

Meanwhile, the plurality of light sources are disposed to face the plurality of condensing lenses 350 as described above.

Specifically, the first light sources 320 configured in the plurality of light sources are positioned to face the center of each condensing lens 350 . Accordingly, the light emitted from the first light source 320 is emitted radially, is refracted on the surface of the condensing lens 350 , and is incident inside the light guide plate 310 in a direction perpendicular to the side surface of the light guide plate 310 . Accordingly, the light guide plate 310 emits a straight light perpendicular to the liquid crystal panel through the upper surface, and as a result, the display image becomes a narrow viewing angle to implement the privacy protection mode.

In addition, the second light sources 330 configured in the plurality of light sources are positioned to face the boundary of the adjacent condensing lens 350 . Accordingly, the light emitted from the second light source 330 is emitted radially, is refracted on the surface of the condensing lens 350 , and is radially incident into the light guide plate 310 . Accordingly, the light guide plate 310 emits radial diffused light through the upper surface, and as a result, the display image becomes a wide viewing angle to implement the privacy protection mode.

In the above embodiment, it has been described that the condensing lens 350 of the present invention is composed of a Fresnel lens. However, the condensing lens 350 of the present invention is not limited to being composed of a Fresnel lens, and may have any shape as long as it has a condensing function. For example, the condensing lens 350 of the present invention may be composed of a refractive lens, a reflective lens, a refractive reflection mixed lens, and the like.

In addition, in the above embodiment, it has been described that the condensing lens 350 of the present invention is formed by molding the side surface of the light guide plate 310 . That is, in the above description, although the condensing lens 350 is configured as a single unit with the light guide plate 310 , the light collecting lens 350 may be configured separately from the light guide plate 310 . For example, the condensing lens 350 may be provided separately between the plurality of light sources and the side surface of the light guide plate 310 . In this case, the condensing lens 350 may have a structure in which a plurality of lenses are stacked or a lens configured to have a single-layer structure.

Meanwhile, each of the plurality of light sources described above may be configured as an LED package. In this case, the LED package may have various forms known in the art. In particular, when the LED package is implemented as a chip-scale package known in the art, the straightness of the light incident on the side of the light guide plate 310 can be further increased, so that the above-described narrow viewing angle can be implemented more easily. . Here, the chip scale package method is a technology for reducing the overall size of the LED package. According to this chip-scale package method, the size of the LED package is implemented to be close to the size of the LED chip emitting light. Since the chip scale package LED is a technology known in the art, a more detailed description thereof will be omitted.

Meanwhile, another embodiment of the present invention may further include a light collecting sheet 360 positioned above the light guide plate 310 to further narrow a viewing angle in the privacy protection mode. This will be described in detail as follows.

That is, as shown in FIG. 8 , in another embodiment of the present invention, the light collecting sheet 360 is further provided on the light guide plate 310 .

The light collecting sheet 360 refracts the straight light emitted from the light guide plate 310 to the upper surface in the privacy protection mode so that the image displayed from the liquid crystal panel has a narrower viewing angle.

To this end, the light collecting sheet 360 is composed of a base film and a plurality of second prism mountains arranged in one direction on the base film. A plurality of second prismatic mountains constitute a single Fresnel lens. In this case, in the single Fresnel lens constituted by the plurality of second prism mountains, the focal point 103 is located at a specific point in time when the liquid crystal panel is viewed from the front.

Specifically, each of the plurality of second prism mountains has a shape inclined in both directions. In addition, the angle of the second prism mountain has a shape in which the slope gradually decreases from both sides toward the center. Accordingly, among the plurality of second prism mountains, the second prism mountains located at both ends have the highest slope, and the second prism mountains located at the center have the smallest or no slope.

The light collecting sheet 360 serves to condense the straight light only when the light emitted from the light guide plate 310 to the upper surface is the straight light to create a narrow viewing angle. That is, when the light emitted from the light guide plate 310 to the upper surface is diffused light, the diffused light has a diffused shape even after passing through the light collecting sheet 360 . Accordingly, the light collecting sheet 360 condenses the light only in the privacy protection mode in which the light traveling straight from the upper surface of the light guide plate 310 is emitted.

Hereinafter, when the light collecting sheet 360 is disposed on the upper surface of the light guide plate 310, it will be described that the privacy protection function is better implemented.

9 is a conceptual diagram illustrating a privacy protection mode in a state in which the light collecting sheet 360 is not applied. 10 is a conceptual diagram illustrating a privacy protection mode in a state in which the light collecting sheet 360 is applied.

According to the illustrated drawing, the liquid crystal display is applied to a notebook computer 1000 . The user V1 is located right in front of the front of the notebook computer 1000 . In addition, first and second peripheral people V2 and V3 are positioned on the left and right sides of the user V1, respectively, and third and fourth peripheral people V4 and V5 are positioned behind the user V1.

As shown in FIG. 9 , when the privacy protection function is implemented in a state where the above-described light collecting sheet 360 is not disposed on the upper surface of the light guide plate, the screen displayed from the notebook computer 1000 is that of the notebook computer 1000 . It is only provided in the front direction. Accordingly, the first and second neighbors V2 and V3 located on the left and right sides of the user V1, respectively, cannot view the screen. That is, the viewing area VZ in which the screen displayed from the notebook computer 1000 can be viewed is formed only within a specific angle range from the normal line of the screen of the notebook computer 1000 . In addition, a region out of a specific angular range from the normal line of the screen of the notebook computer 1000 becomes an unviewed area NVZ in which the screen of the notebook computer 1000 cannot be viewed.

However, in the example shown in FIG. 9 , even if the privacy protection function is implemented, the third and fourth people V4 and V5 located behind the user V1 can view the screen of the notebook computer 1000 . Accordingly, the privacy protection function according to the above example cannot prevent the users V1, V4 and V5 from viewing the privacy image when they want to view the privacy image.

Meanwhile, as shown in FIG. 10 , when the above-described light collecting sheet 360 is disposed on the upper surface of the light guide plate and the privacy protection function is implemented, the screen displayed from the notebook computer 1000 is the notebook computer 1000 . is focused to a specific point in its frontal direction.

Accordingly, not only the first and second neighbors V2 and V3 located on the left and right sides of the user V1, respectively, but also the third and fourth neighbors V4 and V5 located behind the user V1 are displayed on the screen. can't watch That is, the viewing area VZ in which the screen displayed from the notebook computer 1000 can be viewed is formed only within a specific focal distance from the screen of the notebook computer 1000 . In addition, the area out of the focal distance from the screen of the notebook computer 1000 becomes an unviewed area NVZ in which the screen of the notebook computer 1000 cannot be viewed.

Therefore, in the example shown in FIG. 10, not only the people around the left and right sides of the user V1 but also the people around the rear of the user V1 can not see the privacy image, so it provides a more improved privacy protection function can do.

As described above, the present invention switches the operation of the backlight unit irradiating straight light having a direction perpendicular to the rear surface of the liquid crystal panel to the rear surface of the liquid crystal panel and the operation of irradiating radially diffused light to the liquid crystal panel. By doing so, privacy mode or normal mode is implemented. The present invention can reduce costs compared to a method of attaching a viewing angle control film for privacy protection. In addition, there is an advantage in that power consumption is reduced because the structure is simple in switching between the privacy protection function and the normal mode and there is no luminance loss due to the viewing angle control film.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the technical field to which the present invention pertains that various substitutions, modifications and changes are possible without departing from the technical matters of the present invention. It will be clear to those who have the knowledge of Therefore, the scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

100: liquid crystal panel
200: panel driving unit
300: backlight unit
310: light guide plate
350: condensing lens

Claims (6)

liquid crystal panel; and
and a backlight unit disposed on a rear surface of the liquid crystal panel,
The backlight unit
light guide plate;
a plurality of condensing lenses continuously disposed on a side surface of the light guide plate and having a first prism pattern;
a plurality of first light sources positioned to face each central portion of the condensing lenses; and
and a plurality of second light sources positioned to face each boundary between the condensing lenses,
The first prism pattern,
It has a shape in which the slope gradually decreases from the boundary part to the center part,
The liquid crystal display device of claim 1 , wherein the liquid crystal display device has a largest inclination at a position in the boundary portion and a smallest inclination in the central portion. The method of claim 1,
The backlight unit is
A liquid crystal display device for irradiating a straight light having a direction perpendicular to the rear surface of the liquid crystal panel in a privacy protection mode to the rear surface of the liquid crystal panel, and irradiating diffused light radially diffusing in a normal mode to the rear surface of the liquid crystal panel. 3. The method of claim 2,
The first light sources are turned on in the privacy protection mode, and the second light sources are turned on in the normal mode. The method of claim 1,
Each of the plurality of light sources is composed of an LED package, a liquid crystal display. The method of claim 1,
The backlight unit is positioned above the light guide plate and further includes a light collecting sheet including a base film and a plurality of second prism mounts arranged in one direction on the base film,
and the plurality of second prism mountains constitute a single Fresnel lens. 6. The method of claim 5,
The single Fresnel lens constituted by the plurality of second prism mountains has a focus at a specific point in time when the liquid crystal panel is viewed from the front.

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