Back light optical component structure for LCD

LCD backlight optical component structure

The present invention relates to a liquid crystal display (LCD) backlight, and more particularly to an LCD backlight optical component structure that can cover a wider range of angles covered by the LED light source.

Due to its light weight and small size, liquid crystal displays have gradually been applied by display devices of small devices such as notebook computers in the past, and have replaced the trend of traditional CRT screens or televisions. LCD panel size, brightness, contrast and other specifications have also been improving. Among them, under the development needs of large LCDs, sufficient development brightness, wide viewing angle, sharp image contrast and long service life have become the most important focus of R&D. Therefore, under such standards, direct type The shape of the backlight module has become the mainstream of the development of large LCD.

For a conventional direct-lit backlight module, refer to the first figure. The general LCD is composed of a liquid crystal panel 10 in the upper half and a backlight module 20 that provides a light source in the lower half. The backlight module 20 mainly includes a cymbal 21, a diffusion film 22, a light guide plate 23, a reflection cover 24 and a light source 25. The light source 24 currently used in the direct type backlight module includes an electroluminescence (EL), a cold cathode fluorescent lamp (CCFL), a cathode emission lamp (CCL) or a metal halide lamp, among which a cold cathode fluorescent lamp is applied. The widest. The light emitted by the light source 24 directly penetrates the light guide plate 23 and the ruthenium sheet 21 and the diffusion film 22 having the light distribution effect, and can be uniformly emitted from the surface of the backlight module 10 and transmitted into the liquid crystal panel 10.

Compared with the edge-lit backlight module, the direct-type backlight module generally uses a cold cathode fluorescent lamp, because the former has more lamps, and the light can directly penetrate the light guide plate (some are not even provided) The light guide plate can avoid the leakage of some side light, and the overall brightness and luminous efficiency are greatly improved. However, when the number of lamps increases, the heat energy generated is also high, and the temperature rise caused by the liquid crystal molecules or the color photoresist is affected, and the color change is often caused by the backlight module. The thickness is increased to reduce such interference, and thus the thickness of the LCD has to be increased. In addition, the distribution between the lamps is quite easy to produce light and dark stripes, and the alignment has a certain influence.

Therefore, there has been a backlight module using an LED light source instead of a cold cathode fluorescent lamp. Since the LED light source has the characteristics of small volume, low heat generation, low power consumption, long service life, and recent advances in manufacturing technology, the light is emitted. The brightness is constantly increasing, and its manufacturing cost is gradually reduced. It has been gradually applied to various lighting devices. In the future, LED light sources are more likely to replace the current light bulbs or fluorescent light sources, and become the most important light-emitting components in lighting equipment, but with LED light sources. There is still a problem with its existence as an LCD backlight. Please refer to the second figure, in 2θ₁_/₂For example, a 120 degree surface mount type (SMD) LED light source 30 (θ₁_/₂Refers to the angle between the direction and the axial direction when the LED luminous intensity value is half of the axial intensity value, 2 times θ₁_/₂That is, the viewing angle), in the case where the distance from the illuminated surface is X, only 65% of the uniformity can be achieved if the illuminance in the circumferential range in which the diameter can be X is covered by the irradiation. Therefore, under the requirement of a certain degree of uniformity, the area that can be covered is narrow. If the area to be illuminated is uniform and uniform, it is necessary to set a considerable number of LED light sources on the large-sized panel, which will cost considerable The cost; if the number of settings is insufficient, it will not be able to overcome the aforementioned gap between light and dark and uneven illumination, which will affect the quality of the image.

In order to improve the high heat production and poor uniformity of the cold cathode fluorescent lamp, the present invention will provide a lens body that cooperates with the LED light source as a backlight optical component of the LCD backlight, so that the LED light source is fixed. The illumination range under uniformity conditions is increased, and even the illumination uniformity is improved in the range, and at the same time, the number of LEDs in the backlight module can be reduced, thereby reducing the manufacturing cost of the backlight module.

The LCD backlight optical component structure of the present invention comprises: a lens body having a hemispherical arc shape and having a light incident surface and a light exiting surface, the light incident surface being convex and convex, and the curvature thereof is The outer axial direction of the center gradually becomes smaller, and the light exiting surface has an arc-shaped concave shape, and the curvature thereof gradually becomes larger from the outer side of the central axis. Wherein, the light emitting surface of the lens body may be provided with a plurality of light distribution mirror strips arranged in a concentric circle, and the curvature of each of the light distribution mirror strips may be zero, positive or negative. It can also be arranged on the surface of the illuminating surface by a diamond surface, and is filled with a plurality of small illuminating mirror surfaces, and the curvature of the small illuminating mirror surfaces can also be zero, positive or negative, and each small illuminating mirror surface is horizontal. The curvature of the image with the vertical axis may be the same or different.

By creating the LCD backlight optical component, the light emitted by the LED light source can be refracted by the lens body to change the angle of the original light, so that the angle of the overall outgoing light becomes larger, and a larger area can be covered. On the other hand, the distribution of the intensity of the outgoing light is simultaneously changed, so that the region where the intensity of the central axial light is strong is shifted to the two ends of the larger angle of the axial direction, so that the intensity of the light having a larger exit angle is strengthened and lowered. The intensity of the central axial light, so that the light emitted by the LED light source can penetrate the surface of the lens body and illuminate the surface of the outer and far distance, not only will not reduce the uniformity, but may increase Its uniformity. Therefore, by using the creation method, the LED light source can be maintained at a level of high uniformity when used as a backlight of the LCD, and the illumination covers an area that is 4 to 49 times larger than the coverage area of the conventional LED light source. On the one hand, the uniformity of the surface to be illuminated is improved, and on the other hand, since the illumination area is greatly expanded, a small number of LED light sources can be disposed, and thus the advantage of the equipment cost is greatly reduced.

The embodiments of the present invention are further described below in conjunction with the drawings. The following examples are set forth to illustrate the present invention and are not intended to limit the scope of the present invention, and those skilled in the art will not depart from the spirit of the present invention. In the scope of the application, the scope of protection of this creation shall be subject to the definition of the scope of the patent application.

Please refer to the third and fourth figures at the same time. The third figure is a schematic diagram of the LCD backlight optical component of the present embodiment, and the fourth figure is a cross-sectional view of the LCD backlight optical component. The LCD backlight optical component of the present embodiment is a lens body 40 which is a half-spherical arc-shaped mirror body having a light incident surface 41 and a light exit surface 42. The light incident surface 41 is a concave arc surface, and the light exit surface 42 is a circular arc convex surface.

Referring to the fourth figure, the arc concave surface of the light incident surface 41 is centered on the central axis 60, and its curvature is gradually decreased from the central axis 60 to the outer side. That is, as shown in the figure, the angle between the mirror tangential line and the central axis 60 is gradually decreased from the angle a to the angle b and then to the angle c. The arc convex curvature of the light exit surface 42 is increased from small to large from the central axis 60. As shown in the figure, the angle between the mirror tangent and the central axis 60 is gradually increased from the A angle to the B angle and then to the C angle.

Therefore, referring to the fifth figure, the light emitted by the LED light source 30 is refracted by the first time when the light incident surface 41 enters the lens body 40, and the light is further refracted by the light exit surface 42 after the second refracting. The lens body 40. Since the curvature of the incident surface 41 closer to the central axis 60 is larger, the angle of refraction of the incident light from the place is larger, so that the easier it is to be scattered to the sides, away from the outer side of the central axis 60, because of the curvature. Small, the resulting refraction angle is small, so the light in the direction of the two sides does not have a large deflection. When the light rays contact the light-emitting surface 42, the smaller the curvature is closer to the central axis 60, the smaller the angle of refraction is, and the angle of the originally emitted light is not greatly deflected, but away from the outer side of the central axis 60, As the curvature becomes larger, the angle of refraction also increases, and the emitted light is further shifted to both sides of the central axis 60, so that the light emitted from the LED light source 30 greatly increases the area of the illumination, and at the same time, the light is deflected to the sides. The shifting refraction also makes the light intensity on both sides stronger than the central axis square line, thus reinforcing the farther and more widely distributed light intensity emitted from the outer sides of the central axis, so that it illuminates the optical of the LCD backlight. In the case of the diaphragm, it is possible to maintain a comparable illuminance, and the uniformity of the entire illumination area is improved to further improve the quality of the LCD display.

For the second embodiment of the present invention, please refer to the sixth embodiment. In the lens structure of the present embodiment, a plurality of light distribution mirror strips 430 arranged in a concentric circle may be disposed on the surface of the light-emitting surface 43 of the lens body. The mirror strip 430 can be a ramp body 431 having a zero curvature. Each of the beveled bodies 431 is along a tangent to the surface of the light-emitting surface 43 and is angularly changed by two and two, and is extended concentrically from the center of the central axis 60 to extend to the outside. Please also refer to the seventh figure, which is a cross-sectional view of the lens body of the second embodiment of the present invention. The curvature change of the lens body entrance surface 41 is the same as described above, and the angle between the mirror tangential line and the central axis 60 is gradually decreased from the angle a to the angle b and then to the angle c. The change in curvature between the beveled bodies 431 is also the same as the change in the light-emitting surface 42. The central axis 60 is enlarged from the outside to the outside, and is gradually increased from the A angle to the B angle. In this embodiment, the light distribution of the emitted light is also similar to the light distribution of the lens body (refer to FIG. 5), and also has a light-emitting range of the light emitted by the LED light source 30 to exhibit a larger area of illumination. At the same time, by the deviation of the outgoing light to the two sides, the intensity of the outgoing light in the direction of the central axis is lower than that on both sides, and the intensity of the light rays on the outer sides of the central axis is enhanced by the reinforcing of the light intensity on the outer sides of the central axis. The illumination improves the uniformity of the overall panel and improves the LCD display quality.

For the third embodiment of the present invention, please refer to the eighth embodiment and the ninth embodiment. The lens body of the present embodiment may also be provided with a plurality of light-emitting mirror strips arranged in a concentric circle on the surface of the light-emitting surface 43 of the lens body. 430, and the lens strip 430 can be an arc recess 432 having a negative curvature. As described above, each of the arc concave bodies 432 is along a tangent to the surface of the light-emitting surface 43 and is formed at an angle of two to two, and is extended concentrically from the center of the central axis 60 to extend outward. Since each arc concave body 432 has a negative curvature, when the light passes through the surface of the arc concave body 432, there is a scattering phenomenon, and the lens body extends from the central axis to the outer side of the light emitting surface 43, and the dispersion effect of the arc concave body 432 is obtained. The light emitted by the arc concave body 432 is mixed and mixed with light, so that the light emitted by the light can be mixed, so that the uniformity of the emitted light can be improved, and the overall light is further uniformed, and the LCD is improved. Show the effect of quality.

For the fourth embodiment of the present invention, please refer to the tenth and eleventh drawings. The lens body of the present embodiment may also be provided with a plurality of concentric distributions on the surface of the light-emitting surface 43 of the lens structure. The mirror strip 430 can also be an arcuate protrusion 433 having a positive curvature. Each of the arc-shaped protrusions 433 is along a tangent to the surface of the light-emitting surface 43 and changes in angle between the two, and is connected to the outer side by a concentric circle from the center of the central axis 60. Since each arc convex body 433 has a positive curvature, the light passes through the surface of the arc convex body 433, and an intersection light mixing effect is generated, so that the uniformity of the outgoing light can be improved, and the overall light emission is further uniformed. Can improve the display quality of the LCD.

For the fifth embodiment of the present invention, please refer to the twelfth embodiment. In the lens body of the present embodiment, a plurality of small light distribution surfaces 440 arranged in a diamond surface may be disposed on the surface of the light-emitting surface 44 of the lens structure. And the curvature of the small light distribution surface 440 can be zero. It is quite similar to the structure of the aforementioned bevel body 431, and only each bevel body 431 arranged in a concentric circle is further separated by a small bevel block 441 having a smaller mirror area. Therefore, the overall structure of the lens body of the present embodiment is still the same as that of the lens body 40 described above, and only the surface of the light-emitting surface 44 is different. Therefore, the effect of refracting the LED light source to both sides and increasing the intensity of the two sides of the light is not changed. However, the refraction of the small bevel blocks 441 increases the chance of the light being mixed with each other. The effect of emitting light more evenly.

On the other hand, the curvature of the small light distribution surface 440 may be negative or positive, and a plurality of arc-shaped concave or arc-shaped small mirrors arranged in a diamond face manner are respectively formed. Referring to the thirteenth and fourteenth drawings, the arc-shaped or arc-shaped small mirrors formed by the arc-shaped concave or arc-shaped convex mirrors are respectively a small arc concave block 442 and a small arc convex block 443, which are respectively the sixth and seventh of the creation. Example. Each of the small light distribution mirrors 440, whether it is a small arc concave block 442 or a small arc convex block 443, is arranged in the same manner as the small inclined surface block 441, and the difference is only in the curvature of the small light distribution mirror surface 440, regardless of its curvature. Why, both of them have the above-mentioned effect of emitting light to be mixed and mixed, and can also greatly improve the uniformity of the overall illumination of the LED light source. The small arc concave block 442 or the small arc convex block 443 may have the same or different curvature in the horizontal and vertical directions.

For the eighth embodiment of the present invention, please refer to the fifteenth and sixteenth drawings. The lens structure of the present invention may also be a quadrilateral hemispherical curved mirror body, and the mirror body is provided with four vertical cut surfaces 721 on four sides. The lens body 70 also has a light incident surface 71 and a light exit surface 72. The convex curvature of the arc-incident surface 71 is centered on the central axis 60, and gradually decreases from the center to the outer side, and the arc convex curvature of the light-emitting surface 72 is increased outward from the central axis 60. Therefore, the present embodiment also has the above-described effect of refracting the LED light source to both sides and increasing the intensity of the two sides. The light-emitting surface 72, as described above, may be provided with a plurality of light-shielding strips arranged in a concentric circle, and the curvature of the light-shielding strips may be zero, positive or negative. It can also be arranged on the surface of the light-emitting surface 72 in a diamond surface manner, and is filled with a plurality of small light-receiving mirror surfaces, and the curvature of the small light-matching mirror surfaces can also be zero, positive or negative, and each small light mirror surface is horizontal. The curvature of the image with the vertical axis may be the same or different.

The lens body 40 can be attached to an LED light source 30, and the LED light source 30 can be coupled to a base 50 for electrical connection and power supply. Referring to FIG. 18, when the LCD backlight optical component of the present invention is applied to the backlight module, the light incident surface 41 of the lens body 40 is connected to the LED light source 30, and the light exit surface 42 faces the backlight. The optical film Z closest to the LED backlight in the module can be placed at an X distance below the optical film Z, and the light emitted by the LED light source 30 can be irradiated onto the optical film Z after being refracted by the lens body 40. The diameter is in the circumferential region of the Y length, and the diameter Y is approximately 2 to 7 times longer than the distance X. The LED light source used in the foregoing may be an SMD type LED, or other forms of LED, and its illuminating color may be white light or other color light as needed.

According to the present invention, the light emitted by the lens body 40 is close to the axial direction and the angle of the emitted light having a small angle is low, but the irradiation distance is short, the area of diffusion is small, so the illumination is slightly lowered; and the angle of emergence is relatively small. Large rays, which are far away from the surface to be illuminated, and have a large diffusion area, so that the illuminance of the light beam distributed over each unit area is reduced, and the illuminating illuminance which originally causes a large illuminating angle drops sharply, but In the present creation, since the intensity of the emitted light having a large illuminating angle is greatly increased, the illuminance uniformity at the edge can be maintained at 75% or more. That is, when the illuminance of the light source emitted from the LED light source to the optical film Z in the axial direction is calculated at 100, the illuminance of the light having a circumferential edge of a length of 2X to 7X is 75 or more.

Therefore, through the creation of the LCD backlight optical component, the LED backlight can be irradiated in a region with a uniformity of more than 75%, which is about 4 times to 49 times larger than that of the conventional LED light source. On the one hand, the uniformity of the illuminated surface is improved, and on the other hand, due to the large expansion of the illumination area, the LED backlight module can be configured with fewer LED light sources, thereby significantly reducing the cost required for the device.

<p>10. . . LCD panel</p><p>20. . . Backlight module</p><p>twenty one. . . Bract</p><p>twenty two. . . Diffusion sheet</p><p>twenty three. . . Light guide</p><p>twenty four. . . Reflector</p><p>25. . . light source</p><p>30. . . LED light source</p><p>40. . . Lens body</p><p>41. . . Glossy surface</p><p>42. . . Glossy surface</p><p>43. . . Glossy surface</p><p>430. . . Light strip</p><p>431. . . Bevel</p><p>432. . . Arc recess</p><p>433. . . Arc convex</p><p>44. . . Glossy surface</p><p>440. . . Small light mirror</p><p>441. . . Small bevel block</p><p>442. . . Small arc concave block</p><p>443. . . Small arc bump</p><p>50. . . Pedestal</p><p>60. . . The central axis</p><p>70. . . Lens body</p><p>71. . . Glossy surface</p><p>72. . . Glossy surface</p><p>721. . . Vertical section</p><p>X. . . distance</p><p>Y. . . diameter</p><p>Z. . . Optical diaphragm</p>

The first figure is a schematic diagram of a conventional LCD backlight module.

The second figure is a schematic diagram of a conventional LED illumination.

The third figure is a schematic diagram of the LCD of the present creation embodiment.

The fourth figure is a cross-sectional view of the LCD of the present creative embodiment.

The fifth figure is a schematic diagram of the light path of the LCD backlight of the present embodiment.

The sixth drawing is a schematic view of the second embodiment of the present creation.

The seventh drawing is a cross-sectional view of the second embodiment of the present creation.

The eighth figure is a schematic view of the third embodiment of the present creation.

The ninth drawing is a cross-sectional view of a third embodiment of the present creation.

The tenth figure is a schematic view of the fourth embodiment of the present creation.

The eleventh drawing is a cross-sectional view of the fourth embodiment of the present creation.

The twelfth figure is a schematic view of the fifth embodiment of the present creation.

The thirteenth drawing is a cross-sectional view of the sixth embodiment of the present creation.

The fourteenth drawing is a schematic view of the seventh embodiment of the present creation.

The fifteenth diagram is a schematic view of the eighth embodiment of the present creation.

Figure 16 is a cross-sectional view showing an eighth embodiment of the present creation.

The seventeenth figure is a schematic diagram of the present embodiment and the LED light source assembly.

The eighteenth figure is a schematic diagram of illumination of the present embodiment.