KR20010084952A - Large area flat panel display using multi-focuses fresnel lens and roll stemping method - Google Patents

Abstract

PURPOSE: A large scale flat display apparatus using a multi-focussed Fresnel lens and a roll-stamping mode is provided to realize a high quality picture without an external defect by using a Fresnel lens as a magnifying lens. CONSTITUTION: A multi-focussed Fresnel sheet is employed on one sheet in order to reduce an optical defect for the boundary of the sheet generated when a separated single-focussed Fresnel lens sheet is used in a large number. The multi-focussed Fresnel lens sheet is manufactured through a roll-stamping mode. The roll-stamping mode adapts an acrylic sheet, wherein the temperature of a surface of the acrylic sheet is about 85 to 95.C The acrylic sheet is pressed by a roll stamper. The roll stamper is provided with a heater for heating the acrylic sheet. The multi-focussed Fresnel lens sheet serves as a magnifying lens.

Description

Large area flat panel display using multi-focuses fresnel lens and roll stemping method}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-screen flat panel display device. Specifically, a multi-focus Fresnel lens and a multi-focus Fresnel lens sheet for manufacturing a multi-focus Fresnel lens to implement a single screen using a plurality of LCD and other flat panel display elements That's the way to the process.

PDP (Plasma Display Panel), which is currently attempting to be distributed to the general public as a flat panel display device, is still very expensive compared to its size, which is a price formed by difficulty in manufacturing process or limitation of demand. In addition, the LCD device, which is currently in the spotlight as the next generation display device, is also difficult to apply to a large size for home use or advertisement due to a problem of price. Therefore, most of the large display devices using current LCD have a projection method. However, such a large LCD of the projection method is difficult to expect the quality beyond the conventional CRT (Cathod Ray Tube) in the resolution and sharpness, and the mechanical requirements of the optical system in the realization of light and small, one of the biggest advantages of the LCD device It is a big difficulty because of the volume limitation.

Therefore, various attempts have been made on how to make a large screen by tiling a plurality of 15-inch LCDs, which exhibit better yields and can be purchased at low cost.

However, there is a difficulty in solving a structural problem in implementing a large display using the plurality of LCDs, and until now, it has failed to obtain a high quality large display device. More specifically, the technical limitation of the existing tiling type LCD is not only very difficult to make the boundary between the LCD and the LCD apparently difficult, but also the reliability of the direct electrode connection method attempted to reduce the gap. There is a problem that falls. Therefore, the current attempts at this method are in a stalemate state, which may be attributed to the difficulty in simultaneous bonding between the glass and the electrode.

For this reason, the present invention proposes a method of optically seamlessly connecting independent LCDs regardless of the distance between LCDs and neighboring LCDs by using a Fresnel lens serving as a magnifying glass. In addition, a roll stamping method is proposed as a method for manufacturing a Fresnel lens sheet having a multi focus on one sheet as shown in FIG. 1, rather than a single focus Fresnel lens sheet used in a 15-inch class.

As shown in FIG. 2, when four 15-inch LCDs are used, the size of the entire screen is nearly 30 inches, and there are limitations in the existing extrusion, injection, and casting methods to manufacture such a large optical sheet. . Therefore, this problem can be solved through a stamping process of an acrylic resin using a roll stamper as shown in FIG. 3.

In order to achieve the above object, the present invention proposes a process of roll stamping and a manufacturing technique of a stamper for manufacturing a multifocal Fresnel lens sheet to be used for a large screen.

1 is a conceptual diagram of a large display that realizes one screen with excellent appearance by tiling using a Fresnel lens having a plurality of focal points in one sheet, and having a plurality of focal points of images obtained from a plurality of small displays c. Principle to realize on screen a. As a complete image through Fresnel lens b.

2 shows the size of a large display that can be obtained by tiling

3 is an application principle of the roll-stamping method for manufacturing a Fresnel sheet having a plurality of focus on one sheet as a roll stamper in which the acrylic plate, which is mirror surface a, is heated to an appropriate temperature, and the pattern of the Fresnel lens is embossed. b. Principle processed by plane c. With Fresnel lens shape by

4 is a conceptual diagram illustrating enlargement of an image due to a cross-sectional shape of a Fresnel lens; The image from the Fresnel lens b. Distance to c. The magnification is determined by, and the implementation of adjusting the invisible part with this magnification

The present invention is to implement and implement a multi-focus Fresnel sheet in one sheet to reduce the optical defects on the interface of the sheet generated when a plurality of independent single-focus Fresnel lens sheet is used. It consists of a proposal for a practical fabrication process of a focus fresnel lens sheet. 1 and 2 is a conceptual view of forming a single image using a plurality of LCD connected in a tiling method using a multifocal Fresnel lens sheet to be achieved in the present invention. The optical characteristics of the Fresnel lens sheet, specifically, the magnification, depend on the cross-sectional three-dimensional shape of the lens as shown in FIG. 4, and can be sufficiently adjusted by adjusting the gap between the three-dimensional adjustment LCD and the Fresnel lens sheet.

Therefore, as shown in FIG. 4, the image actually seen by the viewer is an enlarged virtual image, which is an image that is displayed by correcting the junction between the LCD and the LCD so that the optical portion is not completely exposed.

In addition, when a plurality of LCD and Fresnel lens sheets are used, a lenticular lens must be used for optical compensation of a seam portion of the Fresnel lens sheet in addition to compensation for non-display portion between the LCD and LCD. Therefore, in order to minimize such a problem, a sheet having a plurality of Fresnel lenses can be manufactured in one sheet, and as an economical method for manufacturing such a sheet, a stamping process using an existing acrylic sheet is proposed as shown in FIG. 3. do. As shown in FIG. 3, an acrylic sheet having an appropriate thickness is pushed between the roll stampers, and the acrylic sheet is stamped by increasing the temperature of the lens processing portion. The acrylic sheet is capable of a stamping process by pressurization at a surface temperature of about 85 to 95 ° C., and for this purpose, a temperature may be adjusted by mounting a heater inside the roll of the roll stamper. In fact, when trying to realize 30 inches using four 15 inch LCDs, the implementation of Fresnel lens sheets having a plurality of focal points is difficult with the conventional molding method. For example, when attempting to mold a sheet having such a structure by an injection process, it is impossible to mold using existing injection pressure, and a high temperature low pressure injection method can be considered, but this is also not an appropriate method due to an increase in production time. In general, the casting method for manufacturing an acrylic sheet may cause distortion in optical properties due to a decrease in uniformity of thickness, and may not be a good method because transferability to a three-dimensional structure is inferior. In addition, uniformity in thickness and the like can be secured in consideration of the production by extrusion method. However, since the temperature of the material is higher than that of the stamping process, it may be an appropriate method for transferring a fine and uniform three-dimensional structure of the Fresnel lens sheet. none.

Therefore, a method of using a plurality of Fresnel lens sheets for a plurality of LCDs is the most common, but this is likely to cause a defect in appearance, matching with adjacent Fresnel sheets when combined with a lenticular lens sheet to hide the junction If not considered, the moiré phenomena caused by the interference between pitches in one or two or more LCDs may appear locally or over the entire area. That is, the biggest reason for using Fresnel lens sheet having a plurality of focal points in one sheet is that it can reduce the appearance defect of the joint, and the precise adjustment according to the optical design can be reflected in the actual product implementation. Because there is.

The present invention employs a Fresnel lens sheet having a plurality of focal points in one sheet for realizing a low-cost, high-quality image implemented by a tiling arrangement of LCDs, particularly LCDs, for a large-screen display device without appearance defects. And a stamping manufacturing method for realizing such a Fresnel lens sheet.

Considering the basic principle of the present invention, it is possible to manufacture a high-quality display that is superior to conventional large-screen display devices at a low cost, which can be realized while maintaining the features of light and small, the biggest advantage of flat panel displays. It can be seen as large. In addition, since the basic configuration is simple and the rate of increase in product prices due to the increase in labor costs is small, it is expected to be positioned as a diffusion technology for more people, and is appropriate for the LCD element, which is currently being controversial in overproduction worldwide. As a consumer, I think that it contributes to the industry.

Claims (2)

A Fresnel lens sheet used to make a single screen by tiling a plurality of LCDs, wherein a multi-focused Fresnel sheet is used in one sheet Process conditions and the principle of product production using the roll stamping structure in the production of multi-focus Fresnel lens sheet