Illuminating device and liquid-crystal display device using the same

1. A liquid crystal display device comprising:

a liquid crystal panel having a pair of substrates, a liquid crystal layer sandwiched between said paired substrates, data lines for applying to said liquid crystal layer a voltage corresponding to image data at a predetermined timing and gate lines, a plurality of active elements connected to intersections of said data lines and said gate lines and pixels driven by said active elements;

an illuminating device having a plurality of LED packages each including LED's and a lens, said LED packages being congregated on a plane in a large area to provide a backlight for irradiating rays of light to said liquid crystal panel;

wherein each LED package includes a high refractive index member containing a substance having a larger refractive index than that of a material forming the lens and said LED is sealed with said high refractive index member, with said lens being superimposed on said high refractive index member;

wherein said lens is shaped to have a recess near its center;

wherein said lens is shaped so that a moving radius increases as a polar angle increases within a range of 0 to 80 degrees; and

wherein the moving radius is defined as a distance starting from the lens center and ending in the lens surface, and the polar angle is defined as an angle that is made by the moving radius to the center axis that is vertical to a plane on which said LED package is located and passing through the center of said lens.

2. A liquid crystal display device according to claim 1 , wherein in a sectional form of said LED package containing the lens center, a boundary between said high refractive index member and said lens is so shaped as to have the form of an arc of circle.

3. A liquid crystal display device according to claim 1 , wherein in a sectional form of said LED package containing the lens center, said boundary between said high refractive index member and said lens is so shaped as to have a recess near the center of said lens.

4. A liquid crystal display device according to claim 1 , wherein when, in a sectional form of said LED package containing the lens center, said distance from the lens center to a boundary is defined as an inner moving radius and the angle making to a center axis being vertical to said plane on which said LED packet is located and passing through the lens center is defined as a polar angle, a boundary between said high refractive index member and the lens is so shaped as to have a region in which as the polar angle increases, the inner moving radius increases.

5. A liquid crystal display device according to claim 1 , wherein in a sectional form of said LED package containing the lens center, a boundary between said high refractive index member and said lens is so shaped as to have an arc of an ellipse whose major axis is in the center axis direction passing through the center of said LED package.

6. A liquid crystal display device according to claim 1 , wherein in a sectional form of the LED package containing the lens center, a boundary between a high refractive index member and said lens is so shaped as to have an arc of an ellipse whose minor axis is in the center axis direction passing through the center of said LED package.

7. A liquid crystal display device according to claim 1 , wherein a shape of a boundary between said high refractive index member and said lens is formed differently in a sectional form of said LED package containing the lens center from that in a sectional form vertical to the former sectional form.

8. A liquid crystal display device according to claim 1 , wherein said lens has a hole bored in its side, and said hole is substantially filled up with said high refractive index member.

9. A liquid crystal display device according to claim 1 ,

wherein each of said LED packages of said illuminating device includes at least four LED's corresponding to LED's for emitting at least red, green and blue; and

wherein at least two of said LED's in each LED package are positioned symmetrically with respect to the center of said lens, and said at least two LED's emit the same color.

10. A liquid crystal display device according to claim 9 , wherein all LED's in each LED package are disposed along a line.

11. A liquid crystal display device according to claim 9 , wherein at least one set of LED's positioned symmetrically with respect to the lens center in each LED package are two LED's positioned at a remotest distance from the center.

12. A liquid crystal display device according to claim 9 wherein each LED package includes two LED's for green, a single LED for red and a single LED for blue, and said two LED's for green are positioned symmetrically with respect to the center of the lens and farthest therefrom.

13. A liquid crystal display device according to claim 9 , wherein when the number of LED's included in each LED package is 2N+1 (N being integer larger than 2), one LED is arranged in the center of the lens, two LED's in the remaining 2N LED's grouped in respective ones of N sets are arranged symmetrically with respect to the lens center in respect of the individual sets, and the LED's constituting each set are for the same color in respect of the individual sets.

14. A liquid crystal display device according to claim 13 , wherein the number of LED's included in each LED package is five, and at least one of two sets of LED's arranged symmetrically with respect to the center of said lens is a set of LED's for green.