KR20050109315A - Liquid crystal display device - Google Patents

Abstract

The present invention relates to a liquid crystal display device in which a hemispherical protrusion is formed on a side of a prism light guide plate to fix a support main and at the same time obtain a high brightness liquid crystal display module, the liquid crystal display panel displaying an image, and the liquid crystal display panel. And a light source for illuminating the light source, a prism light guide plate having light from the light source to the liquid crystal display panel, and having at least one hemispherical protrusion on both sides thereof, and guide parts for fastening protrusions formed on both sides of the prism light guide plate. It characterized in that it is configured to include a support main for receiving.

Description

Liquid crystal display device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device which minimizes distortion caused by light to improve product quality.

A typical liquid crystal display device is composed of a liquid crystal display module, a driving circuit portion and a case for driving the liquid crystal display module.

First, the liquid crystal display module is composed of liquid crystal cells in which a liquid crystal is injected between two glass substrates bonded to each other with a predetermined gap and arranged in a matrix form, and switch elements for switching signals supplied to the liquid crystal cells, respectively. The liquid crystal panel and a back light unit for irradiating light to the liquid crystal panel are configured.

In addition, the liquid crystal display module is arranged with light sheets for vertically raising the light traveling from the backlight unit toward the liquid crystal panel.

In order to prevent light loss, the liquid crystal panel, the backlight unit, and the optical sheet must be fastened in an integrated form and protected from damage by external impact.

To this end, a case top for a liquid crystal display device formed to surround the backlight unit and the light sheets including the edge of the liquid crystal panel is provided.

Since the liquid crystal display module includes a glass substrate, the liquid crystal display module may be easily damaged by an external impact. Thus, a case top is used to surround and protect the exterior of the liquid crystal display module to prevent damage to the liquid crystal display module due to an external impact.

FIG. 1 is a cross-sectional view illustrating a backlight unit of a general liquid crystal display, FIG. 2 is a view showing a prism sheet of FIG. 1, FIG. 3 is a view showing an optical path through a prism sheet shown in FIG. Is a diagram showing independence of x and y components of light.

As shown in FIG. 1, the backlight unit includes a lamp 1 for generating light, a lamp housing 3 that surrounds the lamp 1, condenses and emits light in one direction, and the lamp ( A light guide plate 5 for converting light incident from 1) into a planar light source, a reflection plate 7 positioned below the light guide plate 5 to reflect light traveling to the bottom surface of the light guide plate 5 toward an upper surface thereof; And a diffusion sheet 9 for diffusing light through the light guide plate 5, and first and second prism sheets 11 and 13 for adjusting a traveling direction of light through the diffusion sheet 9. .

The liquid crystal display panel is positioned on the backlight unit configured as described above. The LCD panel includes an upper substrate 21 having a color filter, a common electrode, and an upper alignment layer, a lower substrate 17 having a thin film transistor array, a pixel electrode, and a lower alignment layer, and the upper substrate 21. ) And a liquid crystal 19 injected into an inner space between the lower substrate 17 and the lower substrate 17.

A cold cathode fluorescent lamp is mainly used as the lamp 1 of the backlight unit, and the light generated by the lamp 1 is incident on the light guide plate 5 through an incident surface existing on the side of the light guide plate 5.

The lamp housing 3 has a reflecting surface on its inner surface to reflect light from the lamp 1 toward the incident surface of the light guide plate 5.

The light guide plate 5 has an exit surface that is horizontal to the inclined back surface and is made so that the incident surface and the exit surface of the light guide plate 5 form a right angle. The rear surface of the light guide plate 5 is provided so that the reflecting plate 7 faces.

The light guide plate 5 allows the light incident from the lamp 1 to reach a distance far from the lamp 1. The light guide plate 5 is generally formed of acrylic resin (PMMA) having high strength and not easily being deformed or broken and having good transmittance.

The reflector 7 serves to reduce light loss by reflecting back light incident on the light guide plate 5 toward the light guide plate 5.

When the light from the lamp 1 is incident on the light guide plate 5, the light is reflected at a predetermined angle from the rear surface of the inclined surface and is uniformly directed toward the exit surface.

At this time, the light propagated to the lower surface of the light guide plate 5 is reflected by the reflector 7 and proceeds toward the exit surface.

Light emitted through the exit surface of the light guide plate 5 is diffused to the entire area by the diffusion sheet 9.

On the other hand, when the light incident on the liquid crystal display panel is vertical, the light efficiency is increased. To this end, two prism sheets are stacked and used so that the traveling angle of the light emitted from the light guide plate 5 is perpendicular to the liquid crystal display panel.

The first and second prism sheets 11 and 13 have a shape of a plurality of prism bars having peaks and valleys.

As shown in FIG. 2, the first and second prism sheets 11 and 13 are disposed such that the two prism array directions are perpendicular to each other. Each prism sheet 11 and 13 has a light propagation path in the z-direction, i.e., the direction perpendicular to the liquid crystal display panel, so that light incident from the light guide plate 5 is incident on the upper liquid crystal panel. It serves to change.

In other words, when the peaks and valleys of the prism are directed in the x direction, the light passing through the first prism sheet 11 has only the y component of the light in the z direction, that is, perpendicular to the liquid crystal display panel. Incident. At this time, the optical path of the x component does not change.

Similarly, as shown in FIG. 3, when the prism peaks and valleys of the second prism sheet 13 face the y direction, the light passing through the second prism sheet 13 passes through the peaks and valleys of the prism. While being converted in the z direction, it is incident perpendicularly to the liquid crystal panel. At this time, the path of the y component of the incident light does not change.

Since the light passing through the prism sheet is a vector amount, the x, y, z components of the light are independent of each other. Accordingly, as shown in FIG. 4, in the prism of the acid and valley formed in the x direction to deflect the light of the y component, the light of the x component is not affected, and only the light of the y component is refracted by the refractive index, so that the light is reflected in the z direction. Furnace will change.

Light generated by the backlight unit as described above is incident on the liquid crystal display panel.

In the liquid crystal display panel, the liquid crystal 19 is driven by the voltage difference between the common electrode of the upper substrate 21 and the pixel electrode of the lower substrate 17 to selectively transmit light from the backlight unit to display an image.

Hereinafter, a conventional liquid crystal display device will be described with reference to the accompanying drawings.

5 is an exploded perspective view showing a conventional liquid crystal display device.

As shown in Fig. 5, a liquid crystal display panel 30 for displaying an image, a fluorescent lamp 31 for generating light, a lamp housing 32 for enclosing the fluorescent lamp 31 in a U shape, and The diffusion plate 38, the first prism sheet 37 and the second prism sheet 36, the protective sheet 35, the light guide plate 33, and the reflective plate 34 which are sequentially attached to one surface of the liquid crystal display panel 30. It consists of.

The liquid crystal display panel 30 and a support main 39 for accommodating and fixing the backlight unit are included.

Here, the fluorescent lamp 31, the lamp housing 32 and the diffusion plate 38, the first prism sheet 37 and the second prism sheet 36, the protective sheet 35, the light guide plate 33 and the reflecting plate ( 34) is called a backlight unit.

On the other hand, the backlight unit serves to illuminate the display area A of the liquid crystal display panel 30. Although not shown in the drawing, the display area A of the liquid crystal display panel is composed of two transparent substrates having a polarizing plate attached to an outer surface thereof and a liquid crystal injected between the inner surfaces of the two transparent substrates.

The liquid crystal display device is composed of a driving circuit 40 for driving the display area.

The backlight unit operates in the following manner. When the fluorescent lamp 31 provided on one end surface of the light guide plate 33 is turned on, the light generated by the fluorescent lamp 31 is reflected by the lamp housing 32, and the reflected light is reflected on the light guide plate. It is transmitted through the end face to the end face of the light guide plate in which the fluorescent lamp is not installed. Then, the light is spread over the entire light guide plate 33, and the light is emitted to the display area A of the liquid crystal panel by the diffusion plate 38.

In the liquid crystal display device, a thin film transistor formed in the liquid crystal panel controls a pixel according to a signal from a driving circuit of the liquid crystal display device to selectively pass the light reflected on the display area. The pixels passing through the light selectively gather to display an image on the display area of the liquid crystal panel.

FIG. 6 is a rear view illustrating a state in which the light guide plate is accommodated in the support main in FIG. 5, and FIG. 7 is an enlarged plan view of portion A of FIG. 6.

As shown in FIGS. 6 and 7, the light guide plate 33 accommodated in the support main 39 has a guide part on the side for fixing the light guide plate 30 during a mechanical test (for example, vibration, impact, or drop). 50).

That is, the guide part 50 and the support main of the light guide plate 33 which are formed on the side of the edge portion of the light guide plate 33 which the lamp (not shown) is in contact with, to fix the light guide plate 33 and the support main 39. The guide portion 60 of 39 is engaged with and fixed.

Although not shown in the drawing, the light guide plate 33 is laminated with a plurality of sheets, such as a diffusion sheet, a prism sheet, and a protective sheet, to increase the light efficiency incident to the liquid crystal display panel positioned on the light guide plate 33. Optical sheets are formed.

In addition, the stepped guide part 50 is engaged with the stepped guide part 60 of the support main 39 at the edge of the light guide plate 33. When the light guide plate 33 moves inside the liquid crystal display, the light guide plate 33 directly contacts the lamp. As a result, the guide parts 50 and 60 are provided to prevent the light guide plate 33 from being pushed toward the lamp and damaging the lamp.

That is, the guide parts 50 and 60 prevent the light guide plate 33 from moving when the shock is applied to the liquid crystal display device, thereby preventing the lamp from being damaged.

However, the guide parts 50 and 60 are formed on the side of the edge portion of the light guide plate 33 in contact with the lamp, so that the guide parts 60 of the support main 39 engage with the guide part 50 of the light guide plate 33. Blocks some of the light beams generated by the lamp. As a result, the liquid crystal display of the related art has a dark section at the edge where the guide parts 50 and 60 are located.

In addition, the guide parts 50 and 60 are formed on the side surface of the light guide plate 33 far from the lamp. In this case, the light guide plate 33 has a structure in which the thickness becomes relatively thinner toward the farther from the lamp. Therefore, this type of liquid crystal display has another problem in that the guide part 50 of the light guide plate 33 is easily damaged when a predetermined shock is applied to damage the lamp.

Therefore, the conventional liquid crystal display device has a problem of causing darkening of the edge portion or damage of the lamp.

However, the above-mentioned conventional liquid crystal display device has the following problems.

That is, the guide part of the light guide plate and the guide part of the support main, which are configured on the side of the edge portion of the light guide plate which the lamp is in contact with, to fix the light guide plate and the support main, are fixed to each other. There is a problem in the liquid crystal display module (LCM) image having a dark section at the edge portion where the guide portion is located.

The present invention has been made to solve the above problems and to provide a liquid crystal display device to obtain a high brightness liquid crystal display module while fixing the support main by forming a hemispherical protrusion on the side of the prism light guide plate. have.

The liquid crystal display device according to the present invention for achieving the above object is a liquid crystal display panel for displaying an image, a light source for illuminating the liquid crystal display panel, and the light from the light source to the liquid crystal display panel and both sides And a support main for accommodating the light guide plate, the prism light guide plate having at least one or more hemispherical protrusions, and a guide part for fastening protrusions formed on both sides of the prism light guide plate.

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

8 is an exploded perspective view showing a liquid crystal display device according to the present invention.

As shown in FIG. 8, a liquid crystal display panel 50 for displaying an image, a fluorescent lamp 60 for generating light, a lamp housing 70 for enclosing the fluorescent lamp 60 in a U-shape, and The prism light guide plate 80 converts the light incident from the fluorescent lamp 60 into a planar light source and condenses and emits light in the x and y directions, and a prism light guide plate 80 and a side surface of the prism light guide plate 80. At least one hemispherical protrusion 90 integrally formed, a reflecting plate 100 positioned below the prism light guide plate 80 to reflect the light traveling toward the lower surface of the prism light guide plate 80 toward an upper surface thereof, and the prism A guide part for fastening the diffusion sheet 110 positioned on the light guide plate 80 to diffuse light through the prism light guide plate 80 and the protrusion 90 protruding from the side surface of the prism light guide plate 80. 120 has the liquid crystal display panel It is comprised including the support main 130 which accommodates the board | substrate 50 and the prism light guide plate 80. As shown in FIG.

The liquid crystal display panel 50 is injected into an upper substrate on which a color filter, a common electrode and an upper alignment layer are formed, a lower substrate on which a TFT array, a pixel electrode and a lower alignment layer are formed, and an internal space between the upper substrate and the lower substrate. Composed of liquid crystals.

In addition, a cold cathode fluorescent lamp is mainly used as the light emitting lamp 60, and the light generated from the light emitting lamp 60 is incident on the prism light guide plate 80 through an incident surface existing on the side of the prism light guide plate 80. do.

The lamp housing 70 is made of a metal such as aluminum having good reflection efficiency to reflect light from the light emitting lamp 60 toward the incident surface of the prism light guide plate 80.

In addition, a protective sheet 140 is further configured between the prism light guide plate 80 and the diffusion sheet 110.

On the other hand, the prism light guide plate 80 has a prism-shaped exit surface having an inclined rear surface and a hill and a valley formed in a linear or circular shape. That is, the exit surface of the prism light guide plate 80 is formed with a plurality of prisms formed in a linear or circular shape having a peak and a valley.

Therefore, both the x component and the y component of the light incident on the prism light guide plate 80 having the linear or circular prism can be incident in the z direction, that is, in the vertical direction of the liquid crystal display panel.

Accordingly, it is not necessary to use a prism sheet that had to be used conventionally, and the number of optical components required is reduced by not using the prism sheet.

In addition, it is possible to reduce the amount of light lost by using the prism sheet.

In addition, the light incident from the prism light guide plate 80 allows the light to reach a distance far from the light emitting lamp 60. The prism light guide plate 80 is generally formed of an acrylic resin (PMMA) having high strength and not easily being deformed or broken and having good transmittance.

On the other hand, the reflective plate 100 formed on the back of the prism light guide plate 80 serves to reduce the light loss by re-reflecting the light incident to itself through the back of the prism light guide plate 80 toward the prism light guide plate 80.

In the liquid crystal display device according to the present invention configured as described above, when the light generated from the light emitting lamp 60 is incident on the prism light guide plate 80, the liquid crystal display device is reflected at a predetermined inclination angle from the rear surface of the inclined surface to be uniformly directed toward the exit surface.

At this time, the light propagated to the lower surface of the prism light guide plate 80 is reflected by the reflecting plate 100 to proceed toward the exit surface. Light emitted through the exit surface of the prism light guide plate 80 is uniformly diffused to the entire area by the diffusion sheet 110.

The light generated from the backlight unit is incident on the liquid crystal display panel.

The liquid crystal display panel displays an image by selectively transmitting light from the backlight unit by driving a liquid crystal by a voltage difference between a common electrode of an upper substrate and a pixel electrode of a lower substrate.

FIG. 9 is a rear view illustrating a shape of a light guide plate accommodated in the support main of the liquid crystal display of FIG. 8, and FIG. 10 is an enlarged plan view of part B of FIG. 9.

As shown in FIGS. 9 and 10, a prism light guide plate 80 having a protrusion 90 formed on at least one hemispherical shape is formed on a hemispherical protrusion 90 formed on a side surface of the prism light guide plate 80. Correspondingly, it is housed in the support main 130 having the guide portion 120.

Here, the guide part 120 formed in the support main 130 has a round shape.

Meanwhile, a case top (not shown) made of a metal material is formed to surround an upper edge of the support main 130 and side surfaces of the liquid crystal display panel and the prism light guide plate 80.

FIG. 11 is a cross-sectional view of a liquid crystal display including a prism light guide plate having a protrusion and a support main having a guide portion.

As shown in FIG. 11, a support main 130 having a guide 120, a backlight unit and a liquid crystal display panel 50 stacked inside the support main 120, and a backlight A guide panel 150 disposed between the unit and the liquid crystal display panel 50 to support the liquid crystal display panel 50 and fastened to a side surface of the support main 130 by a hook; A case top 160 for fixing the 150 and the liquid crystal display panel 50 is provided.

Here, the support main 130 is a mold, the side wall surface thereof is formed into a stepped stepped surface.

A prism light guide plate 80 having a protrusion having at least one hemispherical shape at a side thereof to be fastened to the guide part 120 of the support main 130, and a reflecting plate 100 configured under the prism light guide plate 80; The backlight unit including the protective sheet 140 and the diffusion sheet 110 and the lamp housing (70 of FIG. 8) sequentially stacked on the prism light guide plate 80 is mounted.

In addition, the reflective plate 100 guides the light from the backlight unit toward the liquid crystal display panel 50.

In addition, the diffusion sheet 110 allows the light incident at an angle from the surface of the reflecting plate 100 to proceed vertically toward the liquid crystal display panel 50.

Polarizers 52a and 52b are attached to the upper and lower portions of the liquid crystal display panel 50 formed on the backlight unit, respectively. Here, the polarizing plates 52a and 52b serve to extend the viewing angle of the image displayed by the liquid crystal cell matrix.

In the liquid crystal display panel 50, liquid crystal cells are arranged in an active matrix form between the upper substrate 51a and the lower substrate 51b, and each of the liquid crystal cells is configured to switch a video signal. Thin Film Transistor is installed.

Since the refractive index of each of the liquid crystal cells is changed according to the video signal, an image corresponding to the video signal is displayed. A tape carrier package (not shown) in which a driver integrated circuit for applying a driving signal to a thin film transistor is mounted on the lower substrate 51b of the liquid crystal display panel 50.

The case top 160 is manufactured in the form of a square strip having a flat portion and a side portion bent at a right angle. The case top 160 surrounds the guide panel 150 fastened to the edge of the liquid crystal display panel 50 and the support main 130.

12A and 12B are plan views illustrating an example of a prism light guide plate in the liquid crystal display according to the present invention.

As shown in FIG. 12A, the prism light guide plate 80 has peaks and valleys formed in one direction on an upper surface thereof, and mountains and valleys formed in a direction perpendicular to one direction formed on the upper surface of the prism light guide plate 80.

On the other hand, as shown in Figure 12b, the prism light guide plate 80 is formed with a plurality of peaks and valleys in one direction only on the upper surface.

On the other hand, the present invention described above is not limited to the above-described embodiment and the accompanying drawings, it is possible that various substitutions, modifications and changes within the scope without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in Esau.

As described above, the liquid crystal display according to the present invention has the following effects.

First, the hemispherical protrusion on the side of the prism light guide plate is integrally formed with the prism light guide plate and fixed to the support main to fix the conventional light guide plate and the guide part of the support main so that the edge portion has a dark section at the edge of the liquid crystal display module (LCM). ) You can solve the problem of burns.

Second, by using the prism light guide plate, it is possible to achieve high brightness LCD, cost reduction, and quality improvement without using a separate sheet.

1 is a cross-sectional view illustrating a backlight unit of a general liquid crystal display device.

2 is a view showing the prism sheet of FIG.

3 is a view showing an optical path through the prism sheet shown in FIG.

4 is a diagram illustrating independence of x and y components of light;

5 is an exploded perspective view showing a conventional liquid crystal display device

FIG. 6 is a rear view illustrating a light guide plate accommodated in the support main of FIG. 5;

7 is an enlarged plan view of a portion A of FIG. 6;

8 is an exploded perspective view showing a liquid crystal display device according to the present invention;

FIG. 9 is a rear view illustrating a shape of a light guide plate accommodated in a support main in the liquid crystal display of FIG. 8.

10 is an enlarged plan view of a portion B of FIG. 9;

FIG. 11 is a cross-sectional view of an LCD including a prism light guide plate having protrusions and a support main having guide parts.

12A and 12B are plan views showing an example of a prism light guide plate in the liquid crystal display according to the present invention.

Explanation of symbols for the main parts of the drawings

50 liquid crystal display panel 60 fluorescent lamp

70 lamp housing 80 prism light guide plate

90: protrusion 100: reflector

110: diffusion sheet 120: guide part

130: support main

Claims (8)

A liquid crystal display panel displaying an image, A light source for illuminating the liquid crystal display panel; A prism light guide plate configured to propagate light from the light source to the liquid crystal display panel and having at least one hemispherical protrusion on both sides thereof; And a support main part for accommodating the protrusions formed on both sides of the prism light guide plate to accommodate the light guide plate. The liquid crystal display of claim 1, wherein the prism shape of the prism light guide plate is linear or circular. The liquid crystal display of claim 1, wherein the hemispherical protrusion is integrally formed with the prism light guide plate. The liquid crystal display device according to claim 1, wherein the guide part has a round shape. The liquid crystal display of claim 1, wherein the support main is made of a plastic material. The liquid crystal display of claim 1, further comprising a reflector formed under the prism light guide plate. The liquid crystal display device of claim 1, further comprising a diffusion sheet formed on the prism light guide plate. The liquid crystal display device according to claim 1, wherein the light source is a cold cathode fluorescent lamp.