KR20010073935A - Large Size Liquid Crystal Display with Continuous Image - Google Patents

Abstract

PURPOSE: An LCD having a successive image is provided to remove a non-displayed area between liquid crystal panels by enlarging the liquid crystal panels and installing light shielding screens. CONSTITUTION: An LCD has a back light(200) for illuminating liquid crystal panels(400), and an electrode connector(300) between the liquid crystal panels(400) and the back light(200). Connector lines of the electrode connector(300) are electrically connected to the liquid crystal panel through connector terminals(2). Signal lines between the liquid crystal panels(400) are on scanning ray pads to prevent degradation of image quality caused by electric lines shielding a light from the back light(200). The connector lines are placed on a display area to shield the light from the back light(200) degrading image quality. Light shielding screens(40) are placed in front of the liquid crystal panels(400) to transmit only the light passing the display area while shielding a light passing through a non-display area.

Description

Large Size Liquid Crystal Display with Continuous Image

According to the present invention, in a large screen liquid crystal display device having a plurality of liquid crystal panels 100, the image is continuously displayed by eliminating the non-display area between the liquid crystal panel and the liquid crystal panel.

In the conventional large-screen liquid crystal display device having a plurality of liquid crystal panels attached thereto, the non-display area between the liquid crystal panel and the liquid crystal panel is large and the images are discontinuous, and the image quality is deteriorated due to the difference in brightness at the interface. 1 is a plan view of a liquid crystal panel. The signal line pad 1 has a signal line electrode and the scan line pad 3 has a scan line electrode to be connected to an external driving IC. The scan line electrode and the signal line electrode are omitted in the drawing. The width of the signal line pad is indicated by b, and the width of the scanning line pad is indicated by a. The pad widths of the signal and scan lines vary from company to company, but are about 4-5 mm. A light blocking film 5 is formed on the color filter substrate 10 from the edge of the glass substrate to the active area 7. The width of the light blocking film 5 is indicated by c. The light blocking film 5 is made of a metal such as Cr or a resin mixed with a light absorbing material. The width of the light shield is less than about 3mm. The actual image only appears on the display screen 7. FIG. 2 is a view of the liquid crystal panel 100 of FIG. 1 from a cutting line BB '. The liquid crystal panel has a structure in which a liquid crystal is filled between the active element substrate 20 and the color filter substrate 10. The active element substrate 20 and the color filter substrate 10 are attached to each other with a sealing material 6. A polarizing plate 12 and an analyzer plate 11 are attached to the outside of each substrate. The color filter substrate is exposed to the outside, and the active element substrate is in contact with the backlight. Although the analyzer 11 and the polarizing plate 12 are the same material, surface treatment differs. Signal lines are formed on the signal line pads. The signal lines alternate with the electrodes driving red (R), green (G), and blue (B). Since the pitch of one pixel of a monitor LCD screen currently used is about 100 µm, the pixel pitch of the pixel is increased by driving a plurality of signal lines of the same color to realize a large screen that can be viewed from a distance.

A plurality of liquid crystal panel 100 as shown in Figure 1 is attached to make a large screen. 4 is a layout view of a liquid crystal panel of a conventional large screen liquid crystal display device. 4 shows two liquid crystal panels. 4A is a plan view, and FIG. 4B is a sectional view taken along the cutting plane EE '. The right liquid crystal panel of FIG. 4 is an arrangement in which the left liquid crystal panel is mirror-projected about the center. In Fig. 4, the width δ of the non-display area which cannot display an image between the liquid crystal panel and the panel is the distance between the display areas of the two liquid crystal panels. In order to reduce the width δ of the non-display area, the width of the light shielding film of the abutting portion is made small and the glass of the sealing member portion is ground. 3 is a plan view (a) and a cross-sectional view of the liquid crystal panel used in FIG. There is no light shielding film at the right edge in contact with the other liquid crystal panel in Fig. 3, and the width of the sealing material at the right edge is made smaller than the width of the sealing material at the right edge. It also grinds the glass in the right corner to some extent to reduce the non-display area to a minimum. It is called tiling technology to enlarge the screen by attaching two or more panels as shown in FIG. 4, and the width of the non-display area is developed to about 1 mm.

In the prior art, a non-display area is generated, resulting in poor image quality. In the case where two or more liquid crystal panels are attached, the non-display area becomes large due to the width c of the light blocking film, the width b of the signal line and the pad, and the width a of the scanning line pad. Since the width of the light blocking film 5 of the color filter substrate is about 3 mm, the non-display area between the liquid crystal panel and the liquid crystal panel is at least 6 mm. Therefore, because of the non-display area, the size of the pixel must be larger than the width of the non-display area, so there is a problem that the resolution is lowered. Therefore, in order to increase the resolution, it is very important to realize a large screen without a non-display area. In the present invention, an enlarged optical system is configured to eliminate the non-display area between the liquid crystal panel and the liquid crystal panel.

1 is a plan view of a liquid crystal panel.

2 is a cross-sectional view of the liquid crystal panel.

3 is a plan view and a cross-sectional view of a liquid crystal panel used in a conventional large screen liquid crystal display device.

4 is a plan view and a sectional view of a conventional large screen liquid crystal display device.

Fig. 5 is a sectional view of the large screen liquid crystal display device of the present invention.

Fig. 6 is an enlarged view of an image when using a convex lens.

7 is a sectional view of a Fresnel lens.

8 is a sectional view of a Fresnel lens provided with a light shielding film.

9 is a cross-sectional view of various microlenses of the screen portion.

Fig. 10 is a sectional view of a unit screen device of the present invention that is easy to assemble.

11 is a screen portion used in the large screen liquid crystal display device of the present invention.

12 is an example of a backlight used in the large screen liquid crystal display device of the present invention.

Fig. 13 is a sectional view of a large screen liquid crystal display device of the present invention.

※ Explanation of code for main part of drawing

1 signal line pad 2 connection terminal 3 scanning line pad

5 light blocking film 7 display area 10 color filter substrate

20: active element substrate 40: light blocking portion 41: light transmitting portion

50: Fresnel lens 60: convex lens 70: fluorescent lamp

100: liquid crystal panel 200: backlight 300: electrode connection

400 liquid crystal panel portion 500 magnification optical portion 600 screen portion

700: unit screen element 601: symmetrical convex microlens

602: asymmetric bifocal microlens 604: Fresnel lens of the screen portion

701: front unit screen element 702: rear screen unit element

In the present invention, an enlarged optical system is introduced to enlarge the screen of the liquid crystal panel, and the non-display area is eliminated by placing a screen on the portion where the enlarged image is formed.

In order to completely eliminate the non-display area, an enlarged optical unit 500 for enlarging the display screen 7 is introduced to enlarge the screen so that there is no non-display area, and the screen unit 600 in which light spreads in various directions is formed. In this case, continuous images can be realized. Fig. 5 is a sectional view of an example of the large screen liquid crystal display device of the present invention. At the bottom, there is a backlight unit 200 that transmits light to the liquid crystal panel unit 400, and an electrode connection unit 300 is disposed between the liquid crystal panel unit 400 and the backlight unit 200. The connection lines of the electrode connection part are electrically connected to each other through the liquid crystal panel and the connection terminal 2. The wires of the electrode connection part have a signal line between the liquid crystal panel and the liquid crystal panel on the scan line pads 1 and 3 to prevent deterioration of image quality caused by the wires covering the light emitted from the backlight. That is, when the connection lines are placed on the display area 7, the light from the backlight is blocked, so the image quality is deteriorated. The light blocking film 40 is disposed in front of the liquid crystal panel 400 so that only light passing through the display area is transmitted, and light passing through the non-display area is blocked. Magnification optics 500 is usually used a lot of convex lenses.

6 illustrates a relationship between an image of a convex lens and an object. If the Gurley between the convex lens and the convex lens is fi, and the distance between the convex lens and the fo is fo, the magnification and the distance between the Fresnel lens and fo are determined according to the focal length f and fi of the Fresnel lens. do. If fi is smaller than the focal length of the Fresnel lens or greater than twice the focal length, virtual images are formed or the magnification is smaller than 1, so fi must be a value between f and 2f. (Ref. OPTICS p. 145; Author HECHIT, ADDISON-WESLEY Publisher) Using one convex lens will cause reversed phases. In this case, separate signal processing is required.

The magnification optical unit 500 is made of an optical component such as a lens to enlarge the screen. The magnification optics are used to enlarge the screen of the display area of the liquid crystal panel larger than the area included in the non-display area of the liquid crystal panel, and to place the fuzzy curved screen part 600 in various directions on the part where the images of the display area form.

The larger the screen, the larger the volume of the convex lens 60 and the higher the cost, and thus the Fresnel lens 50 is used. The Fresnel lens is made by dividing the convex lens 60 into various regions as shown in FIG. 7 and projecting the curved surface of the convex lens on a thin plane. When the length p of the minimum cross section of the Fresnel lens is smaller than the pitch of the pixel, the effect of the convex lens can be maintained as it is. If the length p of the minimum cross section of the Fresnel lens is larger than the pitch of the pixel, the image quality is degraded because the influence of the portion where the cross section of the Fresnel lens meets appears on the screen screen.

The image forming part in front of the magnification optical part 500 is provided with a screen part 600 for scattering light in various directions. Although the Fresnel lens on the non-display area of the liquid crystal panel 100 of the liquid crystal panel 400 of FIG. 5 does not have a film blocking light, the light blocking film is disposed on the Fresnel lens portion on the non-display area of the liquid crystal panel as shown in FIG. If you put it, you can increase the contrast ratio because it completely blocks the light passing through the unwanted area. In FIG. 5, the microlens of the screen unit 600 may have a diameter smaller than the pitch of pixels to maintain the resolution. 9 shows the shape of the microlens of the screen portion. 9A is a convex microlens in front of the screen portion. In this case, the light spreads out evenly in all directions. However, if it is made asymmetrical as shown in (b) of FIG. 9, it can send a lot of light in a specific direction. In the case of the large-screen liquid crystal display of the present invention, since the light is installed at a high place, the light passing in the 12 o'clock direction is almost ineffective. Therefore, if placed in a hemisphere as shown in Figure 9 (b) can collect a lot of light in a specific direction. The microlenses of the screen part can be mass-produced and lowered by making plastic injection molding.

When the unit screen device 700 including the liquid crystal panel unit, the optical unit, and the screen is constituted as one unit module, and a plurality of these units are connected to form a large screen, when the screen size is changed, the unit screen device of the vertical and horizontal axes is By varying the combination of, the additional design cost and installation cost can be greatly reduced. The Graphic LED Module, which is currently commercially available, makes large screens by attaching multiple LEDs based on 256 pixels of each of 16 LEDs each vertically and horizontally. In the present invention, the screen can be configured by combining the unit screen device by making a unit screen device having one or several liquid crystal panels as in the LED. Fig. 10 is a sectional view of a unit screen device of the projection type large screen liquid crystal display device of the present invention. The larger the fluorescent lamp of the backlight is, the lower the relative unit cost is and the light efficiency is excellent. Therefore, when a large screen is formed by attaching several unit screen devices, it is more economical to make the backlight unit more common than to place the unit screen device inside. In addition, if the screen area is used in common so that several unit screen elements can be attached, the continuity of the image can be improved. There may be one liquid crystal panel as shown in FIG. 10, or may have several unit unit devices. When the size of the liquid crystal panel is 10 "or less, it is easy to assemble several liquid crystal panels to make a unit screen element.

In order to increase the continuity of the screen, the Fresnel lens 604 having a large focal length is placed on the screen portion. In order for the planar lens 604 of the screen unit to readjust the light propagation direction to increase the continuity of the screen, the Fresnel lens 604 should be designed to correspond to the liquid crystal panel 1: 1.

As people pass in both directions, such as subways and underground walkways, large-screen LCDs must be made so that they can be seen in both directions. 12 are various embodiments of the present invention, shown in both directions. The front unit screen element 701 and the rear unit screen element 702 are arranged with the backlight unit 200 in the center. 12 (a) shows two lines of fluorescent light of the backlight in order to brighten the screen, and FIG. 12 (b) shows one line in detail to increase the uniformity of brightness rather than the brightness.

Currently, the fluorescent lamp 70 for a backlight in a notebook or a monitor is a cold cathode tube (cold cathod), the life time is very long, while the efficiency is low. Fluorescent lamps used for indoor lighting in homes are hot cathods and have a short lifespan but high efficiency. The lifetime of high-performance hot cathode tubes is currently in production from about 7,000 hours to 20,000 hours. However, assuming 20,000 hours of operation, about 2.2 years, the backlight needs to be replaced every time. However, if the extra fluorescent lamp is installed inside the backlight unit in advance, and only the power is supplied at the replacement time, the life of the backlight unit can be extended.

In the case of a large number of unit screen elements 700, since the number of connection wires is increased, if the electrode connecting portion 300 is placed outside the backlight fluorescent lamp, the space occupied by the electrode connecting portion does not affect the image quality. In this case, however, the through hole must be made so that the connecting wire can be out of the backlight unit. Fig. 13 is an embodiment of the invention in which the connecting wire is placed outside the backlight fluorescent lamp.

In the large-screen liquid crystal display device for displaying an image of the present invention, the diagonal direction of the screen is 1 m or more, and the pixel pitch is 1 mm or more when the mode of the screen is QVGA (320 x 240). In case of making the large screen liquid crystal display device of the present invention by using a conventional laptop or monitor liquid crystal panel, rather than driving each signal line and the scan line separately, a plurality of adjacent signal lines for driving the same color are bundled and adjacent scan lines are connected. It is easy to construct a circuit by applying several bundles and applying the same scan voltage. The average number of signal lines that are used in electrical contact with each other depends on the mode of the screen and the pitch of the liquid crystal panel. Usually, more than 10 scan lines and signal lines are connected and driven. Therefore, even if one or two scanning lines and signal lines do not operate, there is no big problem in operating the entire screen. However, if the area of the malfunctioning part is large, the image quality is reduced, so that the part can be covered and used.

Since the large screen liquid crystal display device of the present invention has no non-display area, the screen is highly continuous. In addition, the shape of the microlens of the screen is asymmetrical to adjust the direction of light to increase the brightness in a specific direction. The large screen liquid crystal display device of the present invention is used as a large display device indoors and outdoors, and mainly used as a presentation screen of a large lecture hall and a large display device of an indoor gym. In particular, the present invention uses a bad liquid crystal panel such as a signal line short circuit that occurs in the production of LCD screen elements for notebooks or monitors, it is possible to realize a large screen with low cost.

Claims (12)

A liquid crystal panel 100 electrically driving a plurality of signal lines for driving the same color; A liquid crystal panel unit 400 including a plurality of liquid crystal panels; A magnification optical unit 500 for enlarging the screen of each liquid crystal panel; Liquid crystal display device comprising a screen portion 600 to which the enlarged image is formed The liquid crystal display device of claim 1, comprising a plurality of unit screen devices 700. The liquid crystal display device according to claim 1, wherein a light shielding film for blocking light emitted from the backlight is provided at the connection portion between the liquid crystal panel and the panel, and the electrode connection portion 300 is placed in the non-display area portion between the liquid crystal panel. The liquid crystal display device of claim 1, wherein the screen portion is formed of a micro lens. The liquid crystal display device according to claim 5, wherein the microlenses have an asymmetric structure. The liquid crystal display device according to claim 5, wherein the microlens is a plastic injection molded product. The liquid crystal display device according to claim 1, wherein at least one Fresnel lens is included in the magnifying optical unit. The liquid crystal display device of claim 7, wherein the liquid crystal panel is disposed at a distance from the Fresnel lens that is farther from the Fresnel lens and closer than two times the Fresnel lens focal length. The liquid crystal display of claim 1, wherein the screen is displayed in both directions with respect to the backlight. The liquid crystal display device of claim 1, wherein the use time is controlled by dividing the lamp of the backlight into several units. The liquid crystal display device according to claim 1, wherein the liquid crystal panel is formed by a process of blocking or absorbing light passing through some pixels which are inoperative. The liquid crystal display device of claim 1, wherein the connection electrode is connected to the liquid crystal panel through the backlight unit.