Light-emitting diode and backlight system using the same

• US 7,278,756 B2
• Filed: 09/27/2004
• Issued: 10/09/2007
• Est. Priority Date: 11/14/2003
• Status: Expired due to Fees

• Current Assignee: Gold Charm Limited (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: Leu, Charles, Chen, Ga-Lane, Yu, Tai-Cherng
• Primary Examiner(s): Ward; John Anthony
• Assistant Examiner(s): MAKIYA, DAVID J
• Application Number:
  US10/950,737
• Publication Number:
  US 20050117320A1
• Time in Patent Office: 1,107 Days
• Field of Search: 362612-614, 362/293, 362/260, 362/555, 257/100, 257/E33.061, 313/502, 313/512
• US Class Current: 362/260
• CPC Class Codes: G02B 6/0023 provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/508 having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material

Abstract

A light-emitting diode (LED) (10) includes a chip body (103), an encapsulation can (105) surrounding the chip body, and a base (106) supporting the encapsulation can and the chip body thereon. Numerous fluorescent particles (1050) are provided in the encapsulation can. With the fluorescent particles, light beams from the chip body are diffused and attain wider irradiation angles. A backlight system (900) includes a light guide plate (20), and a number of the above-described LEDs disposed adjacent to the light guide plate. Light beams having wide irradiation angles are emitted from the LEDs and enter the light guide plate. This enables a light emitting surface of the light guide plate to have highly uniform brightness.

Claims

1. A light-emitting diode comprising:

a base;

a chip body fixed on the base; and

a single encapsulation can covering the chip body;

wherein a plurality of fluorescent particles having diameters in the range from 1 μ

m to 10 μ

m is contained in the single encapsulation can for scattering light emitted from the chip body, and the fluorescent particles are distributed in a region of the single encapsulation can distal from the chip body and progressively increase in size with increasing distance along a perpendicular direction away from a vertical, center axis of the region and constant in size in columns parallel to the vertical, center axis.

2. The light-emitting diode as claimed in claim 1, wherein the fluorescent particles comprise items selected from the group consisting of green fluorescent material, red fluorescent material, yellow fluorescent material and blue fluorescent material.

3. The light-emitting diode as claimed in claim 2, wherein the selected items are configured to be in proportions whereby the light-emitting diode emits white light.

4. The light-emitting diode as claimed in claim 2, wherein the green fluorescent material is Fluorescein Isothiocyanate, the red fluorescent material is NileBlue A, the yellow fluorescent material is Rhodamine B, and the blue fluorescent material is alkaline silicate.

5. A backlight system comprising:

a light guide plate having a light incident surface, a light emitting surface adjacent to the light incident surface, and a bottom surface opposite to the light emitting surface; and

at least one light-emitting diode having a base, a chip body fixed on the base, and a single encapsulation can covering the chip body;

wherein a plurality of fluorescent particles having diameters in the range from 1 μ

m to 10 μ

m is contained in the single encapsulation can for scattering light emitted from the chip body, and the fluorescent particles are distributed in a region of the single encapsulation can distal from the chip body and progressively increase in size with increasing distance along a perpendicular direction away from a vertical, center axis of the region and constant in size in columns parallel to the vertical, center axis.

6. The backlight system as claimed in claim 5, wherein the fluorescent particles comprise items selected from the group consisting of green fluorescent material, red fluorescent material, yellow fluorescent material and blue fluorescent material.

7. The backlight system as claimed in claim 6, wherein the selected items are configured to be in proportions whereby said light-emitting diode emits white light.

8. The backlight system as claimed in claim 6, wherein the green fluorescent material is Fluorescein Isothiocyanate, the red fluorescent material is NileBlue A, the yellow fluorescent material is Rhodamine B, and the blue fluorescent material is alkaline silicate.