KR100650413B1 - Panel for enhancing light uniformity and back light unit of using the same - Google Patents

Abstract

  A base substrate, a lower light scattering layer formed on a lower surface of the base substrate, a support film attached below the lower light scattering layer, a light blocking layer interpolated in the lower light scattering layer, and an upper surface of the base substrate. A light homogenizing plate is formed on an upper light scattering layer and a lower surface of the support film and includes a light collecting layer formed of a Fresnel lens array or a hologram pattern. The use of such an optical homogenizer plate can reduce the thickness of the liquid crystal display device by about 30% or more, and it also simplifies the process and reduces the manufacturing cost by replacing the conventional film using an optical homogenizer plate. can do.

Liquid Crystal Display, Backlight Unit, Light Uniformizer

Description

Optical uniform plate and backlight unit using same {Panel for enhancing light uniformity and back light unit of using the same}

1 is an exploded perspective view of a general direct type liquid crystal display.

2 is an exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention.

3 and 4 are cross-sectional views of the optical homogenizing plate used in FIG. 2.

5 is an exploded perspective view of a liquid crystal display according to another exemplary embodiment of the present invention.

6 and 7 are cross-sectional views of the optical homogenizing plate used in FIG. 5.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight device for a liquid crystal display device and a plate capable of increasing the uniformity of backlight light using the same.

Recently, along with the development of the technology of the information processing apparatus, the development of the technology of the display apparatus for interfacing so that a user can recognize the data processed by the information processing apparatus has been made.

As the display device, a liquid crystal display having a light weight, a small size, and a function such as full-color and high resolution are widely used. Specifically, the liquid crystal display device is a display device for converting a change in the optical properties of the liquid crystal cell into a visual change. Such a liquid crystal display requires light because an image is displayed using a liquid crystal, which is a light receiving element that does not emit light by itself. Accordingly, the liquid crystal display receives light from the backlight assembly attached to the rear surface of the liquid crystal panel and displays an image.

The backlight assembly is divided into a direct type and an edge type according to the position of the light source. The edge type backlight assembly has a structure in which a lamp unit is installed on a side of a light guide plate, and is mainly applied to a relatively small liquid crystal display device such as a laptop and a desktop computer. Such an edge type backlight assembly has a good light uniformity, a long service life, and is advantageous for thinning a liquid crystal display device.

On the other hand, the direct type backlight assembly is a structure mainly developed as the size of the liquid crystal display device increases in size, and one or more lamps are arranged in a row on the lower surface of the diffusion plate to irradiate light to the liquid crystal panel in full area. Such a direct type backlight assembly has advantages in that a plurality of light sources can be used as compared to an edge type backlight assembly, thereby ensuring high luminance.

1 is an exploded perspective view of a general direct type liquid crystal display.

Referring to FIG. 1, the direct type liquid crystal display device 100 includes a liquid crystal panel assembly 110 representing a screen and a direct type backlight assembly 120 for providing light to the liquid crystal panel assembly 110.

The liquid crystal panel assembly 110 includes a thin film transistor (hereinafter, referred to as a TFT) substrate 111a and a color filter substrate 111b and a liquid crystal injected between the TFT substrate 111a and the color filter substrate 111b. It has a liquid crystal panel 111 made of (not shown). The data printed circuit board 115, the gate printed circuit board 114, the data side tape carrier package (hereinafter referred to as TCP) 113, and the gate side TCP 112 are formed.

Meanwhile, the direct type backlight assembly 120 uniformly diffuses the first light by the lamp unit 121 generating the first light, the reflecting plate 123 for reflecting the first light generated from the lamp unit 121, and the first light. And a bottom chassis 125 for accommodating the light control unit 122 and the lamp unit 121, the reflection plate 123, and the diffusion plate 122 to emit the second light having one luminance distribution. Here, the light control unit 122 is a diffusion plate 122a, a diffusion sheet 122b, a low prism sheet 122c, an upper prism sheet 122d, and a polarizing light-receiving sequentially disposed on the diffusion plate 122a. The sheet 122e is included.

The bottom chassis 125 is formed in a box shape of a rectangular parallelepiped having an upper surface opened. A storage space having a predetermined depth is formed inside the bottom chassis 125, and a reflection plate 123 is disposed along an inner surface of the storage space, and the lamp units 121 are installed side by side on the reflection plate 123. do. In addition, the light control unit 122 is seated on the bottom chassis 125 by being spaced apart from the lamp unit 121 at a predetermined interval.

Here, the lamp unit 121 may include at least one lamp 121a, a lamp holder 121b provided at opposite ends of the at least one lamp 121a, a first electrode line 121c drawn out from a first end of both ends, and a lamp holder 121b. The second electrode line 121d is drawn out from the second end facing the first end. In this case, the first electrode line 121c applies a first power supply voltage to the plurality of lamps 121, and the second electrode line 121d applies a second power supply voltage to one or more lamps 121. To this end, the first and second electrode lines 121c and 121d are connected to power supply devices (not shown) for generating the first and second power supply voltages, respectively.

In order to connect the first and second electrode lines 121c and 121d to the power supply device, it is necessary to extend one of the first and second electrode lines 121c and 121d to the side where the remaining electrode lines are located.

In this case, the second extended electrode line 121d is disposed on the rear surface of the reflective plate 123 so that the direct type liquid crystal display 100 does not interfere with the screen. A storage space for accommodating the second electrode line 121d is provided between the reflective plate 123 and the bottom chassis 125.

Meanwhile, the mold frame 130 is disposed on the light adjusting unit 122, and the liquid crystal panel 111 is seated on the second step of the mold frame 130. Thereafter, a top chassis 140 is provided on the liquid crystal panel 111 so as to be opposed to the bottom chassis 125. Thereby, the direct type liquid crystal display device 100 is completed.

In the liquid crystal display, the light emitted from the backlight unit including the reflector 123, the lamp unit 121, and the light control unit 122 should have a uniform amount of light on the entire light emitting surface of the backlight unit. However, since the lamp 121a is a linear light source, the shorter the distance from the lamp 121a, the greater the amount of light and the farther the light amount is. Although the light adjusting unit 122 is provided to obtain uniform surface light, there is a problem in that the light is not uniform. In particular, in the portion immediately above the lamp 121a, the amount of light may be excessively large, resulting in a bright line. In order to solve this problem, the distance between the lamp 121a and the light control unit 122 should be sufficiently large, which is contrary to the trend of making the thickness of the liquid crystal display thin.

In addition, the plurality of films to be disposed in the light control unit 122, but this takes a lot of time, there is also a problem that the cost of the film entering the light control unit 122 is expensive, the product cost increases.

An object of the present invention is to simplify the manufacturing process of the backlight unit for a liquid crystal display device.

Another object of the present invention is to make the thickness of the backlight unit for a liquid crystal display device thin.

Another technical problem to be achieved by the present invention is to provide a high-efficiency light homogenizing plate and a backlight unit emitting uniform surface light while increasing light efficiency.

In order to solve this problem, in the present invention, a base substrate, a lower light scattering layer formed on a lower surface of the base substrate, a support film attached below the lower light scattering layer, and a light blocking layer interpolated in the lower light scattering layer, An optical homogenizing plate including an upper light scattering layer formed on an upper surface of the base substrate is provided.

The light emitting layer may further include a light collecting layer formed on a lower surface of the support film, and the light collecting layer may be a Fresnel lens array or a hologram pattern.

The light blocking layer may block light propagation by reflecting light, and the light homogenizing plate may further include a polarizing dimming layer formed on the light scattering layer.

The light blocking layer may include a plurality of bands arranged side by side at predetermined intervals, and the bands of the light blocking layer may be formed in parallel with a center line of the Fresnel lens forming the light collecting layer.

The upper and lower light scattering layers may be formed by curing a material mixed with a transparent adhesive and a light scattering agent. The upper light scattering layer may be formed of a diffusion film and an adhesive, and the lower light scattering layer may be a transparent adhesive and a light scattering agent. It can also be formed by curing the material.

By using such an optical homogenizing plate, the following backlight unit can be provided.

A storage container having a storage space formed through a bottom surface and a side wall protruding from an edge of the bottom surface, a plurality of lamps disposed on a bottom surface of the storage container, a base substrate disposed on the lamp, and a base substrate; A light including a lower light scattering layer formed on a lower surface, a support film attached below the lower light scattering layer, a light blocking layer interpolated in the lower light scattering layer, and an upper light scattering layer formed on an upper surface of the base substrate. Backlight unit including a homogenizing plate.

The light homogenizing plate may further include a light collecting layer formed on a lower surface of the support film and formed of a Fresnel lens array or a hologram pattern. The light blocking layer may be disposed side by side at intervals, and the bands of the light blocking layer may be formed side by side at a position corresponding to the center line of the Fresnel lens forming the light collecting layer.

In addition, the optical homogenizing plate may further include a polarizing dimming layer formed on the light scattering layer, or may further include a polarizing dimming sheet disposed on the light homogenizing plate.

DETAILED DESCRIPTION Embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily practice the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. When a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the other part being "right over" but also another part in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

Next, a liquid crystal display according to an exemplary embodiment of the present invention will be described with reference to the drawings.

2 is an exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the liquid crystal display 200 may include a liquid crystal panel assembly 210 representing a screen, a backlight assembly 220 providing light to the liquid crystal panel assembly 210, and a liquid crystal panel assembly in the backlight assembly 220. A mold frame 230 for seating 210 and a top chassis 240 for fixing the seated liquid crystal panel assembly 210 are included.

The liquid crystal panel assembly 210 is composed of a TFT substrate 211a and a color filter substrate 211b and a liquid crystal (not shown) injected between the TFT substrate 211a and the color filter substrate 211b to display an image. It has a liquid crystal panel 211. The liquid crystal panel assembly 210 also includes a data printed circuit board 215, a gate printed circuit board 214, a data side tape carrier package (hereinafter referred to as TCP) 213 and a gate side TCP 212. It further includes providing an electrical signal for the image display to the liquid crystal panel 211.

The backlight assembly 220 includes a lamp assembly 221, a light homogenizing plate 240, a polarization dimming sheet 222e, a reflecting plate 223, and a bottom chassis 224, and converts a line light source into a surface light source to form a liquid crystal. It is provided to the panel 211.

In more detail, the lamp assembly 221 includes a plurality of lamps 221a, lamp holders 221b respectively provided at opposing opposite ends of the plurality of lamps 221a, and first electrode lines 221c drawn out from first ends of both ends. And a second electrode line 221d drawn out from the second end facing the first end to emit light. The light emitted at this time is a linear light source.

That is, the first electrode line 221c applies a first power supply voltage to one or more lamps 221, and the second electrode line 221d applies a second power supply voltage to one or more lamps 221. To this end, the first and second electrode lines 221c and 121d are respectively connected to a power supply device (not shown) that generates the first and second power voltages.

In order to connect the first and second electrode lines 221c and 221d to a power supply, not shown, one of the first and second electrode lines 221c and 221d is extended to the side where the other electrode line is located. In general, the second electrode line 221d to which the power supply voltage relatively lower than the power supply voltage applied to the first electrode line 221c is applied extends to the side from which the first electrode line 221c is drawn out. In this case, the elongated second electrode line 221d is disposed on the rear surface of the reflective plate 223 so that the direct type liquid crystal display 200 does not interfere with the screen. A storage space for accommodating the second electrode wire 221d is provided between the reflective plate 223 and the bottom chassis 225.

The light homogenizing plate 240 includes a light collecting layer, a light scattering layer, a light blocking layer, and the like, and efficiently converts the linear light emitted from the lamp 221a into uniform surface light. The light homogenizing plate 240 will be described in more detail later.

The polarization dimming sheet 222e improves the brightness of the light provided from the light uniformizing plate 240 and provides the brightness enhanced light to the liquid crystal panel 211.

As the polarizing light-decreasing sheet 222e, 3M's DBEF or DRPF is used. The polarizing light dimming sheet 222e recycles light by allowing P waves to pass through the light homogenizing plate 240 and reflecting S waves to be converted to P waves. That is, brightness is raised by converting and using the S wave component removed by the polarizing film into a P wave component as much as possible.

The bottom chassis 224 has a bottom surface, sidewalls protruding from an edge of the bottom surface, and an accommodating space formed in a box shape of a rectangular parallelepiped having the top surface opened. A reflection plate 223 reflecting the light emitted from the lamp 221a is disposed along the inner surface of the storage space, and lamps provided in the lamp assembly 221 are disposed above the reflection plate 223. Installed side by side. In addition, the bottom chassis 224 is spaced apart from the lamp assembly 221 by a predetermined interval is mounted on the polarizing light-sensitive sheet 222e.

The mold frame 230 may be installed on the top surface of the bottom chassis 224 to prevent the polarizing light-decreasing sheet 222e and the light homogenizing plate 240 from being separated in the upper direction of the bottom chassis 224. Although the mold frame 230 has been described as being installed on the upper surface of the bottom chassis 224, a lower mold frame (not shown) may be additionally provided to support the plurality of lamps. In this case, the mold frame 230 becomes the upper mold frame, which is fastened with the lower mold frame to prevent the polarization of the polarizing light dimming sheet 222e and the light homogenizing plate 240.

The top chassis 240 fixes the liquid crystal panel assembly 210 mounted on the mold frame 230.

Then, the structure of the light homogenizing plate 240 will be described in more detail.

3 is a cross-sectional view of an optical uniform plate according to an embodiment of the present invention.

First, referring to FIG. 3, the light homogenizing plate includes a transparent base substrate 241 made of acrylic or polycarbonate (PC), a lower light scattering layer 242 and a lower light scattering layer formed on a lower surface of the base substrate 241. A transparent support film 244 attached to the bottom of 242 and made of a polyethylenetelephthalate (PET), a light blocking layer 243 formed on the upper surface of the support film 244 and interpolated in the lower light scattering layer 242. , The light collecting layer 245 formed on the lower surface of the support film 244 and the upper light scattering layer 246 formed on the upper surface of the base substrate 241.

The base substrate 241 maintains the shape of the light homogenizing plate 240 and is a base on which upper and lower light scattering layers 242 and 246 are formed.

The support film 244 is a support of the light blocking layer 243 and the Fresnel lens 245.

The light collecting layer 245 is formed of a one-dimensional Fresnel lens array. That is, a plurality of band-shaped Fresnel lenses are arranged in succession. Here, the center line of each Fresnel lens is arranged so as to be parallel to the axis of the lamp 221a and located directly above the axis of the lamp 221a, as shown in FIG. The Fresnel lens array collects light emitted from the lamp 221a to face the liquid crystal panel 111.

Here, the holographic pattern may be used as the light collecting layer 245 instead of the Fresnel lens array.

The upper and lower light scattering layers 242 and 246 are formed by mixing a light scattering agent with a transparent adhesive to be hardened. The lower light scattering layer 242 also serves to attach the base substrate 241 and the supporting film 244.

The light blocking layer 243 blocks and reflects light concentrated directly above the lamp 221a to prevent the portion from appearing as a bright line. Therefore, the light blocking layer 243 is also formed in a band shape at a position corresponding to the lamp 221a. The light reflected by the light blocking layer 243 is reflected by the reflecting plate 223 and recycled.

The function of such an optical homogenizer will be described.

When light is emitted from the lamp 221a, the light collecting layer 245 collects the light toward the upper side (the direction in which the liquid crystal panel is located), and the light having a high intensity is moved straight through the lamp 221a. It is reflected by the single layer 243 and returned. The remaining light is first scattered and mixed in the lower light scattering layer 242 and secondly scattered and mixed in the upper light scattering layer 242 to emit light of uniform intensity across the entire surface of the light homogenizing plate.

By using the optical uniform plate, the lamp 221a may be disposed in close proximity to the optical uniform plate 240, thereby reducing the thickness by about 30% or more compared with the conventional liquid crystal display.

In addition, by replacing the conventional film using a number of films in one optical uniform plate 240, the process for the layout can be simplified and manufacturing cost can be reduced.

Next, a method of manufacturing such a light homogenizing plate will be described.

The light blocking layer 243 is formed on the support film 244 by printing or the like, and a light collecting layer is formed on the lower surface of the support film 244 by an injection molding method using a metal frame.

Moreover, the upper surface of the base substrate 241 is apply | coated the substance which mixed the light-scattering agent to the transparent adhesive agent, and it hardens by the method of irradiating an ultraviolet-ray.

Next, a material in which a light scattering agent is mixed is applied to a lower surface of the base substrate 241 or an upper surface of the support film 244, and the base substrate 241 and the support film 244 are adhered to each other, followed by ultraviolet irradiation. The light homogenizing plate is completed by curing the transparent adhesive through.

4 is a cross-sectional view of an optical uniform plate according to another embodiment of the present invention.

The light homogenizing plate of FIG. 4 has a structure in which the upper light scattering layer 246 is replaced with a diffusion film 248 and an adhesive layer 247 in the light homogenizing plate of FIG. 3.

5 is an exploded perspective view of a liquid crystal display according to another exemplary embodiment of the present invention.

The liquid crystal display according to the exemplary embodiment of FIG. 5 is different from the liquid crystal display according to the exemplary embodiment of FIG. 2 in that the liquid crystal display according to the exemplary embodiment of FIG. 2 is not included. That is, in the embodiment of FIG. 5, the light homogenizing plate 240 includes the polarizing dimming layer and thus does not separately arrange the polarizing dimming sheet.

In this case, the w manufacturing process is further simplified and manufacturing cost is reduced by replacing the polarizing light-decreasing sheet with one optical homogenizing plate 240.

6 and 7 are cross-sectional views of the optical homogenizing plate used in FIG. 5.

First, the light homogenizing plate of FIG. 6 has a structure in which a polarizing light-sensing layer 249 is further formed on the light uniformizing plate of FIG. 3. That is, the polarizing light-sensing layer 249 is further formed on the upper light scattering layer 246.

The polarizing dimming layer 249 is formed by adhering a sheet such as DBEF or DRPF, or by coating or depositing a material having a property of passing one of the P wave component and the S wave component of light and reflecting the other one. do.

The light homogenizing plate of FIG. 7 is a structure in which the polarizing light-sensing layer 249 is further formed on the light homogenizing plate of FIG. 4. That is, the polarizing light-sensing layer 249 is further formed on the diffusion film 248.

The polarizing light dimming layer 249 used in FIG. 7 also adheres a sheet such as DBEF or DRPF, or applies a material having a property of passing one of the P wave component and the S wave component of light and reflecting the other. By vapor deposition.

In the above embodiment, the light blocking layer 243 is formed on the support film 244, but the light blocking layer 243 may be formed on the bottom surface of the base substrate 241.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

As described above, in the present invention, the thickness of the liquid crystal display device can be reduced by about 30% or more by using the optical homogenizing plate, and the process for the arrangement is replaced by replacing the conventional film using one optical uniforming plate with one optical uniforming plate. This simplifies manufacturing costs.

Claims (13)

 Foundation substrate, A lower light scattering layer formed on a lower surface of the base substrate, A support film attached to the lower light scattering layer, A light blocking layer interpolated in the lower light scattering layer, An upper light scattering layer formed on an upper surface of the base substrate And a base substrate, a lower light scattering layer, a supporting film, a light blocking layer, and an upper light scattering layer. In claim 1, The light homogenizing plate further comprises a light collecting layer formed on the lower surface of the support film. In claim 2, The light collecting layer is a Fresnel lens array or a hologram pattern. In claim 1, The light blocking layer is a light homogenizing plate to block the progress of light by reflecting light. In claim 1, The light homogenizing plate further comprises a polarizing light-sensing layer formed on the light scattering layer. In claim 3, The light blocking layer includes a plurality of bands arranged side by side, and the band of the light blocking layer is formed side by side at a position corresponding to the center line of the Fresnel lens forming the light collecting layer. In claim 1, The upper and lower light scattering layer is a light homogenizing plate formed by curing a material mixed with a transparent adhesive and a light scattering agent. In claim 1, The upper light scattering layer is composed of a diffusion film and an adhesive, the lower light scattering layer is a light homogenizing plate formed by curing a material mixed with a transparent adhesive and a light scattering agent. A storage container having a bottom surface and a storage space formed through sidewalls protruding from an edge of the bottom surface, A plurality of lamps disposed on a bottom surface of the storage container, A base substrate, a lower light scattering layer formed on a lower surface of the base substrate, a support film attached below the lower light scattering layer, a light blocking layer interpolated in the lower light scattering layer, and the base And an upper light scattering layer formed on an upper surface of the substrate, wherein the base substrate, the lower light scattering layer, the support film, the light blocking layer, and the upper light scattering layer are integrated with each other. In claim 9, The light homogenizing plate is formed on a lower surface of the support film and further comprises a light collecting layer made of a Fresnel lens array or a hologram pattern. In claim 10, The light blocking layer of the light homogenizing plate is formed of a plurality of bands arranged side by side at a predetermined interval, the band of the light blocking layer is formed in a position corresponding to the center line of the Fresnel lens constituting the light collecting layer. Backlight unit. In claim 9, The light homogenizing plate further comprises a polarizing light-sensing layer formed on the light scattering layer. In claim 9, The backlight unit further comprises a polarizing light-sensing sheet disposed on the optical uniform plate.

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