KR20030081975A - Apparatus for supplying light and liquid crystal display device using the same - Google Patents

Abstract

PURPOSE: A light supply device and a liquid crystal display using the light supply device are provided to convert lights generated from a point light source into display lights having a plane light distribution to provide the display lights to a liquid crystal display panel assembly to reduce the volume, weight and power consumption of the liquid crystal display. CONSTITUTION: A light supply device(500) includes a base substrate(100), a plurality of point light sources(200), and a means for reducing luminance deviation(300). The point light sources are arranged on the base substrate and generate the first light according to power supplied through a power supply line. The means for reducing luminance deviation is placed on a traveling path of the first light and emits the second light having reduced deviation between the first luminance measured by the point light sources and the second luminance measured between the point light sources.

Description

Optical supply device and liquid crystal display device using the same {APPARATUS FOR SUPPLYING LIGHT AND LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME}

The present invention relates to a light supply device and a liquid crystal display device using the same, and in particular, by using a point light source that generates light by a direct current power source, greatly reducing the volume, weight and power consumption, as well as luminance unevenness due to the point light source characteristics The present invention relates to an optical supply device and a liquid crystal display device using the same to overcome the problems.

In general, a liquid crystal display device (LCD) is defined as a device for displaying text, video, and video by precisely controlling a liquid crystal (LC) having a characteristic of changing light transmittance in response to an electric field. can do.

Accordingly, the liquid crystal display device requires a liquid crystal control part for precisely controlling the liquid crystal in small area units and a light supplying part for supplying light to the precisely controlled liquid crystal, respectively. In particular, the light supply part for supplying light to the liquid crystal precisely controlled by the liquid crystal control part among them is very important in terms of the overall volume and weight of the liquid crystal display device.

This is because even if the liquid crystal control part precisely controls the liquid crystal, a fatal display failure occurs when the luminance of the light supplied to the liquid crystal is not uniform.

The light supply part that plays such an important role is composed of a light generating part including a light source for generating light again, and an optical sheet for improving the brightness uniformity of light generated from the light generating part.

In this case, a cold cathode ray tube lamp is mainly used as a light source for generating light in the light generating part. The cold cathode ray tube lamp used as a light source in the light generating part generates white light similar to sunlight, has a long life, is easy to manufacture, and a small amount of heat generated in the process of generating light.

In this case, since a conventional cold cathode ray tube lamp is operated by AC power, a portable inverter using DC power as a main power source should be used with a cold cathode ray tube lamp. For this reason, a liquid crystal display using a cold cathode ray tube type lamp has a problem in that volume and weight become larger.

In addition, the conventional cold cathode ray tube type lamp requires a very high level of AC power because it is driven by the discharge, there is also a problem that a lot of energy loss occurs in the process to greatly increase the power consumption of the liquid crystal display device. .

Accordingly, the present invention has been made in view of such a conventional problem, and the first object of the present invention is to enable the light source to be turned on without converting the DC power, thereby reducing the weight and volume of the liquid crystal display device and reducing the amount of power consumption. In providing a supply device.

A second object of the present invention is to provide a liquid crystal display device which reduces the weight, volume, and power consumption by enabling the light source to be turned on without converting the DC power.

1 is a conceptual diagram of an optical supply apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of a base substrate, a point light source, and a power supply line of the light supply device of FIG. 1.

3 is an enlarged view of a portion A of FIG. 2.

4 is a conceptual diagram of an optical supply apparatus according to another embodiment of the present invention.

5 is a conceptual diagram of an optical supply apparatus according to another embodiment of the present invention.

6 is a conceptual diagram of a light supply apparatus according to another embodiment of the present invention.

FIG. 7 is a conceptual diagram illustrating a method of manufacturing FIG. 6.

8 is a conceptual diagram of an optical supply apparatus according to another embodiment of the present invention.

9 is a conceptual diagram of a liquid crystal display according to an embodiment of the present invention.

FIG. 10 is an exploded perspective view of the liquid crystal display panel assembly of the liquid crystal display panel assembly of FIG. 9.

11 is an exploded perspective view of a light supply apparatus according to still another embodiment of the present invention.

12 is a sectional view taken along the line A-A in the state in which FIG. 10 is coupled;

FIG. 13 is a conceptual diagram of a liquid crystal display device in which the light supply device of FIG. 10 is coupled.

The light supply device for implementing the first object of the present invention is arranged on the base substrate, the base substrate, a plurality of point light sources, the first light generated by the power supplied through the power supply line, the first And a luminance deviation reducing means provided on the traveling path of the light to emit the third light having the first luminance measured at the point light source and the luminance deviation of the second luminance measured between the point light source and the point light source reduced.

In addition, the light supply device for implementing the first object of the present invention is a light generating device arranged on the base substrate, the base substrate, and including a plurality of point light sources for generating light by the power supplied through the power supply line And a light guide plate having a plurality of side surfaces on which the light generating device is installed, a light reflecting surface reflecting light generated by the light generating device, and a light emitting surface.

In addition, the liquid crystal display device for implementing the second object of the present invention is arranged on the base substrate, the base substrate, a plurality of point light sources, the first light generated by the power supplied through the power supply line, the first A light supply provided on a traveling path of the light, the light supply including a luminance deviation reducing means for emitting the third light having the first luminance measured at the point light source and the luminance deviation of the second luminance measured between the point light source and the point light source reduced; And a liquid crystal display panel assembly configured to emit the fifth light including information in the course of passing the third light generated by the device and the light supply device through the controlled liquid crystal.

Hereinafter, a unique operation and effects of the light supply device and the liquid crystal display device using the same according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

<First Embodiment>

1 is a conceptual diagram of a light supply device 500 according to a preferred embodiment of the present invention.

Referring to FIG. 1, the light supply apparatus 500 generally includes a base substrate 100, point light sources 200, and a luminance deviation reducing member 300.

More specifically, the base substrate 100 has a planar size of m × n corresponding to the display area required in a plate shape as shown in FIG. 2. In a preferred embodiment, the base substrate 100 may be coated with a light reflecting material having a high light reflectivity to form a light reflecting layer 110, or the base substrate 100 may be made of a material having a high light reflectance.

Meanwhile, as shown in FIG. 2, a power supply line 150 for turning on the point light source 200 is formed on the base substrate 100. The power supply line 150 is composed of a first power supply line 152 (shown by a solid line) and a second power supply line 154 (shown by a dotted line).

A plurality of first power supply lines 152 are formed on the base substrate 100 in parallel with each other in the number of rows of the point light sources 200 to be arranged in a matrix form. At this time, each first power supply line 152 is commonly connected. Meanwhile, the second power applying line 154 is formed adjacent to each first power applying line 152, and each second power applying line 154 is commonly connected.

As illustrated in FIG. 2 or FIG. 3, the point light sources 200 are disposed in the first power applying line 152 and the second power applying line 154 of the power applying line 150 having such a configuration. In one embodiment, the point light source 200 installed in the power supply line 150 is a light emitting diode (LED) that generates white light. Reference numerals 210 and 220 are terminals of the point light source 200 electrically connected to the power applying line 150.

As such, when power is supplied to the power supply line 150 in a state in which the point light source 200 is disposed on the base substrate 100, the point light source 200 has a “first brightness” as shown in FIG. 1. Generates "first light 230".

The first light 230 generated by the point light source 200 is suitable for use as light for display in the liquid crystal display.

However, in order to obtain a higher quality display in the liquid crystal display device, the luminance deviation between the "second luminance" defined by the luminance measured between the point light sources 200 and the first luminance which is the luminance in the point light source 200 is minimized. Should be.

To this end, as illustrated in FIG. 1, a luminance deviation reducing plate (ie, a “third light 310” having a reduced variation in first and second luminance is emitted on a path through which light travels from the point light source 200). 300) is installed.

More specifically, the luminance deviation reducing plate 300 is a light diffusion member receiving and diffusing the first light 230.

Meanwhile, in another embodiment, the light guide plate 400 is further installed in the light supply device 500 as shown in FIG. 4 to further improve the performance of the light supply device 500 shown in FIG. 1.

The light guide plate 400 allows the optical distribution of the first light 230 generated from the point light source 200 to be changed to be closer to the surface light source, and the light path of the point light source 200 is reduced in luminance deviation plate 300. The "second light 410" changed toward the exit.

In this case, the point light source 200 installed to protrude from the surface of the base substrate 100 is in contact with the bottom surface of the light guide plate 400, and thus a gap is formed between the base substrate 100 and the bottom surface of the light guide plate 400. Will exist. This gap acts as a factor to increase the overall volume of the light supply device 500, so the smaller the gap, the better.

For this reason, as shown in FIG. 5, a point light source receiving groove 420 accommodating the point light source 200 is formed at the bottom 401 of the light guide plate 400 facing the point light source 200 of the light guide plate 400. Can be further formed.

That is, by allowing the point light source 200 to be accommodated in the point light source receiving groove 420 formed in the light guide plate 400, the gap existing between the light guide plate 400 and the base substrate 100 may be minimized or completely removed. .

As a result, the volume of the light supply device 500 can be minimized, and when the light supply device 500 is applied to the liquid crystal display device, the total volume of the liquid crystal display device can be minimized. In addition, when the life of the point light source 200 is over, the point light source 200 can be replaced relatively easily.

Meanwhile, in FIG. 6, the light supply device 500 that can reduce the gap existing between the light guide plate 400 and the base substrate 100 is described.

Referring to FIG. 6, the light guide plate 400 has a shape in which a synthetic resin material melted on the base substrate 100 on which the point light source 200 is formed encapsulates the point light source 200 in a plate shape.

In order to implement this, in one embodiment, a mold 460 as shown in FIG. 7 is required. The mold 460 is composed of the upper mold 450 and the lower mold 430 coupled with the upper mold 450. The light guide plate manufacturing material is melted in the upper mold 450 and the lower mold 430 while the base substrate 100 having the point light source 200 is disposed between the upper mold 450 and the lower mold 430. Supplied. Through such a process, a light supply device 500 in which the base substrate 100-the point light source 200-the light guide plate 400 is integrally manufactured is manufactured, and the light supply device 500 can minimize unnecessary light loss. Has the advantage.

In another embodiment, the light concentrating member 490 may be further installed in the light supply device 500 illustrated in FIG. 8. The light concentrating member 490 changes the light propagation direction of the third light 310 generated by the luminance deviation reducing plate 300 of the light supply device 500 to improve the front view angle. "Let it come out. At this time, the light concentrating member 490 is a plate in which a prism-shaped triangular pillar is continuously formed on one side in a preferred embodiment.

This light concentrating member 490 is applicable to the embodiment shown in FIG. 1, the embodiment shown in FIG. 4, the embodiment shown in FIG. 5, and the embodiment shown in FIG. 6.

Among these embodiments, the light supply device 500 having the configuration as shown in FIG. 1 is combined with the liquid crystal display panel assembly 600 as shown in FIG. 9 to form the liquid crystal display device 700.

In this case, the liquid crystal display panel assembly 600 receives light from the light supply device 500 according to various embodiments described above in detail so that the “fifth light 610” including information is emitted, and the user The image may be recognized by the fifth light 610.

The liquid crystal display panel assembly 600 that receives the light from the light supply device 500 and emits the fifth light 610 including the information will be described in detail with reference to FIG. 10.

The liquid crystal display panel assembly 600 is composed of a liquid crystal display panel 650 and a driving module 680 composed of a color filter substrate 620, a TFT substrate 630, and a liquid crystal 640.

The TFT substrate 630 is again a glass substrate 632, a thin film transistor (not shown) formed on the glass substrate 632, a gate signal applying line 634, a data signal applying line 636, and a pixel to operate the thin film transistor. It consists of an electrode (not shown).

The color filter substrate 620 is composed of a glass substrate 621, a color filter (not shown) and a common electrode installed on the glass substrate 621 to face the pixel electrode. The driving module 680 again includes a gate printed circuit board 660 that applies a driving signal to the gate signal applying line 634, a source printed circuit board 665 which applies a driving signal to the data signal applying line 636, and a gate. A gate tape carrier package 670 provided between the printed circuit board 660 and the gate signal applying line 634 and a source tape carrier package 675 provided between the source printed circuit board 665 and the data signal applying line 636. It consists of.

Second Embodiment

Meanwhile, FIG. 11 shows a second embodiment of the present invention.

In the second embodiment, a point light source of the light supply device 800 supplies light to a side surface of the light guide plate so that a liquid crystal display is performed. The light supply device 800 is particularly suitable for a very thin liquid crystal display device such as a portable notebook and a small and medium liquid crystal display device.

11 or 12, the light supply device 800 may include the reflector 810 and the light generating plate 820. In addition, the light supply device 800 may further include a luminance compensation plate 830 for uniformizing the luminance distribution of the light generated by the light generation plate 810.

More specifically, the reflector 810 is formed by bending a thin rectangular parallelepiped plate into a "c" shape. Thus, the reflector 810 is composed of a first reflector plate 801, a second reflector plate 802, and a third reflector plate 803. In this case, the first reflector plate 801 and the third reflector plate 803 face each other and have a shape connected to each other by the second reflector plate 802.

At this time, as a preferred embodiment, a portion of the first reflector plate 801 and the third reflector plate 803 is further formed with grooves 804 and 805 extending in the Y direction of the coordinate system shown in FIG. 11 again by a press process or the like. do.

Thus, the interior of the reflector 810 is divided into two regions at the boundaries of the grooves 804 and 805. Hereinafter, any one of these two regions will be referred to as the first region and referred to as the first region, and the other one will be referred to as the first region and referred to as the second region.

The light generating plate 820 is accommodated and installed in the first region 810a, and the light guide plate illustrated in FIG. 13 is installed in the second region 810b.

On the other hand, as the area of the first reflector plate 801 increases, the amount of light emitted to the light guide plate is reduced, and thus it is preferable to remove the remaining portions except for both ends of the first reflector plate 801 as shown in FIG. 11. Hereinafter, a portion of the first reflector plate 801 that remains without being removed will be referred to as a light guide plate coupling portion 801a.

On the other hand, the light generating plate 820 is composed of a thin printed circuit board 822 and at least one point light source 824 again. More specifically, the plurality of power supply lines 825 and 826 are formed on the printed circuit board 822 along the defined Y axis. Power supply terminals, not shown, are formed in each power supply line, and point light sources are electrically coupled to the power supply terminals. At this time, the power supply lines 825 and 826 are at least one column or more.

In this case, the point light source 824 is connected to each of the power supply terminals by various methods. For example, the power supply terminal and the point light source are implemented by an adhesive conductive film or reflow soldering.

In a preferred embodiment, the point light source 824 used in <Second Embodiment> of the present invention is an LED that generates white light by a DC power supply.

In this case, the brightness may be reduced between the point light sources 824 arranged in series on the light generating plate 820, so as to overcome this, as shown in FIG. 11, the first region 810a and the second region. The luminance compensation plate 830 may be further provided between the 810b.

As shown in FIG. 13, the second region 810b of the light supply device 810 having such a configuration has a rectangular parallelepiped shape and is disposed between the light guide plate coupling portion 801 and the third housing plate 802. The light guide plate 850 having a thickness to be fitted is coupled. The light guide plate 850 serves to change the light generated by the light supply device 800 into a surface light source, and at the same time, the light traveling direction is directed toward the liquid crystal display panel 890 shown in FIG. 12. do.

In the state where the light guide plate 850 is coupled to the light supply device 800 as shown in FIG. 13, the light leaking from the light guide plate 850 is again supplied to the light guide plate 850 at the bottom of the light guide plate 850. A reflecting plate 860 to perform is further installed.

A plurality of optical sheets 870 and 880 are further provided on the upper surface of the light guide plate 850 to make the luminance distribution of the light emitted from the light guide plate 850 more uniform.

An upper surface of the optical sheets 870 and 880 is provided with a liquid crystal display panel 890 for processing light that does not contain information to produce image light that includes information.

As described in detail above, the light having the surface light source optical distribution is generated using a point light source that generates light by a DC power source, and the image is displayed from the liquid crystal display using the light having the surface light source optical distribution. As a result, the volume, weight and power consumption of the liquid crystal display can be reduced, and the number of parts of the liquid crystal display can be reduced by not using an inverter for converting an AC power source into a DC power source.

In the detailed description of the present invention described above with reference to a preferred embodiment of the present invention, those skilled in the art or those skilled in the art having ordinary knowledge in the scope of the invention described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

Claims (18)

A base substrate; A plurality of point light sources arranged on the base substrate to generate first light by power supplied through a power supply line; And Luminance deviation reduction means provided on the traveling path of the first light and outputting the second light whose luminance deviation of the first luminance measured at the point light source and the second luminance measured between the point light source and the point light source is reduced; Light supply device comprising a. 2. The light supply apparatus according to claim 1, further comprising a light guide plate between the point light source and the brightness deviation reducing means, which emits a light path of the first light generated from the point light source and a third light whose optical distribution is changed. . The light supply apparatus of claim 2, wherein the light guide plate is further provided with a point light source receiving groove so that a gap does not occur between the light guide plate and the surface of the base substrate on which the point light source is installed. 2. The light emitting device of claim 1, wherein the base substrate on which the point light source is formed is encapsulated in a plate shape to encapsulate an optical path changing part that emits a third light whose optical path and optical distribution of the first light generated from the point light source are changed. Light supply device. The light supplying device according to claim 1, wherein the brightness deviation reducing means is a light diffusing member having a plate shape. 6. The light supply apparatus according to claim 5, wherein a light condensing member for emitting the fourth light in which the direction of the second light is corrected is further provided on an upper surface of the light diffusing member. The light supply device of claim 1, wherein a light reflection layer made of a light reflection material is further formed on a surface of the base substrate on which the point light source is formed. The optical supply apparatus according to claim 1, wherein a DC power is applied to the power applying line. The light supply device of claim 1, wherein the point light source is a light emitting diode (LED). The light supply apparatus of claim 1, wherein the point light sources are arranged in a matrix form. A light generating device arranged on the base substrate, the light generating device including a plurality of point light sources for generating light by power supplied through a power supply line; And And a light guide plate having a plurality of side surfaces on which the light generating device is installed, a light reflecting surface reflecting light generated by the light generating device, and a light emitting surface. 12. The light supply apparatus of claim 11, wherein the light generating device is installed in a reflector coupled to the light guide plate. 13. The light supply apparatus according to claim 12, wherein a light diffusing member is further disposed between the point light source and the light guide plate to diffuse the light generated from the point light source. The optical supply apparatus of claim 11, wherein the base substrate is a printed circuit board on which a power supply line is formed. 12. The light supply apparatus of claim 11, wherein the light generating device is formed on two opposite sides of the light guide plate. 12. The light supply apparatus according to claim 11, wherein a point light source receiving groove is formed at a side surface of the light guide plate to accommodate the point light source, and the point light source is coupled to the point light source receiving groove. The light supply apparatus of claim 11, wherein the point light source is integrally coupled to a side surface of the light guide plate. 12. The light supply apparatus of claim 11, wherein the point light source is arranged in a line form at least one column on the base substrate.