Light source module and display apparatus having the same

• US 8,304,978 B2
• Filed: 04/01/2009
• Issued: 11/06/2012
• Est. Priority Date: 09/11/2008
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Kim, Hyun-Jin, Nam, Seok-Hyun, Lee, Dong-Chin, Kim, Hyuk-Hwan, Wang, Min-Jeong
• Primary Examiner(s): Green, Tracie Y
• Application Number:
  US12/416,721
• Publication Number:
  US 20100117947A1
• Time in Patent Office: 1,315 Days
• Field of Search: 313498-512, 445 24- 25
• US Class Current: 313/500
• CPC Class Codes: C09K 11/592 Chalcogenides
• CPC Class Codes: C09K 11/595 with zinc or cadmium
• CPC Class Codes: G02F 1/133603 with LEDs

Abstract

A light source module includes first and second light sources. The first light source includes a blue light-emitting body emitting blue light and a red fluorescent material disposed around the blue light-emitting body emitting red light by virtue of being excited by the blue light. The second light source is disposed adjacent to the first light source, and includes a green light-emitting body emitting green light. The blue and green light-emitting materials may include a light-emitting diode (LED) chip including substantially the same material. Accordingly, since a variation of light efficiency of the light source module with respect to temperature is small, a color feedback system may be omitted, and color reproducibility may be high.

Claims

1. A light source module for a display device comprising:

a first light source including a blue light-emitting body emitting blue light and a red fluorescent material covering the blue light-emitting body, and emitting red light from the red fluorescent material excited by the blue light from the blue light-emitting body; and

a second light source disposed adjacent to the first light source, and including a green light-emitting body emitting green light,

wherein each of the variation rates of the amounts of the red, green and blue light is within about ±

10% with respect to a reference amount of light which is an average value of the amounts of the red, green and blue light at 20°

C., when the temperature is in a range between about −

40°

C. and about 100°

C.

2. The light source module of claim 1, wherein the red fluorescent material comprises a silicate-based fluorescent material consisting of a Zn2SiO4:

Mn2+ fluorescent material, a Mg2SiO4;

Mn2+ fluorescent material, a Ba2SiO4;

Mn2+ fluorescent material, a Sr2SiO4;

Mn2+ fluorescent material, or a Ca2SiO4;

Mn2+ fluorescent material.

3. The light source module of claim 2, wherein the blue light-emitting body and the green light-emitting body each comprise a light-emitting diode (LED) chip including a GaN-based material.

4. The light source module of claim 2, further comprising a driving part individually applying a driving current to the blue light-emitting body and the green light-emitting body to control color coordinates of the module-emitted light.

5. The light source module of claim 4, wherein the driving part individually applies a predetermined driving current to the blue light-emitting body and the green light-emitting body to reach target color coordinates of the module-emitted light, without using a feedback device sensing the light emitted from the first and second light sources and feeding the light back to control the color coordinates of the module-emitted light.

6. The light source module of claim 5, wherein the driving part individually applies the driving current to the blue light-emitting body and the green light-emitting body to generate white light from the module-emitted light.

7. The light source module of claim 4, further comprising a power-transmitting substrate electrically connected to the driving part, wherein a plurality of basic clusters is formed on the power-transmitting substrate, and each of the basic clusters includes the first and second light sources.

8. The light source module of claim 7, wherein the distance between the basic clusters adjacent to each other is different from the distance between the first and second light sources.

9. The light source module of claim 7,

wherein the first light source further comprises a first cover portion enclosing the blue light-emitting body, the second light source further comprises a second cover portion enclosing the green light-emitting body, and the red fluorescent material is dispersed within the first cover portion.

10. A display apparatus comprising:

a display panel displaying an image;

a light guide unit disposed on a rear surface of the display panel; and

a light source module disposed on at least one surface of the light guide unit, the light source module including;

a first light source including a blue light-emitting body emitting blue light and a red fluorescent material covering the blue light-emitting body, and emitting red light from the red fluorescent material excited by the blue light from the blue light-emitting body; and

a second light source disposed adjacent to the first light source, and including a green light-emitting body emitting green light,

wherein each of the variation rates of the amounts of the red, green and blue light is within about ±

10% with respect to a reference amount of light which is an average value of the amounts of the red, green and blue light at 20°

C., when the temperature is in a range between about −

40°

C. and about 100°

C.

11. The display apparatus of claim 10, wherein the blue light-emitting body and the green light-emitting body each comprise an LED chip including substantially the same material, such that an amount of light emitted from the blue light-emitting body and an amount of the light emitted from the green light-emitting body each vary with changes in temperature by substantially the same amount.

12. The display apparatus of claim 11, wherein the red fluorescent material comprises a silicate-based fluorescent material consisting of a Zn2SiO4:

Mn2+ fluorescent material, a Mg2SiO4;

Mn2+ fluorescent material, a Ba2SiO4;

Mn2+ fluorescent material, a Sr2SiO4;

Mn2+ fluorescent material, or a Ca2SiO4;

Mn2+ fluorescent material.

13. The display apparatus of claim 12, further comprising a light source driving part individually applying a driving current to the blue light-emitting body and the green light-emitting body to control color coordinates of the module-emitted light.

14. The display apparatus of claim 13, further comprising a panel driving part transmitting a panel driving signal displaying the image to the display panel, and transmitting a light source driving signal to the light source driving part, the light source driving signal being linked with the panel driving signal and individually designating a driving current to the blue light-emitting body and the green light-emitting body.

15. The display apparatus of claim 14, wherein the panel driving part individually applies a predetermined driving current to the blue light-emitting body and the green light-emitting body to reach target color coordinates of the module-emitted light, without using a feedback device sensing the light emitted from the first and second light sources and feeding the light back to control the color coordinates of the light source module.

16. The display apparatus of claim 15, wherein the panel driving part dims a color and brightness of the module-emitted light of the light source module in accordance with a color and a brightness of the image.

17. The display apparatus of claim 15, wherein color reproducibility of the module-emitted light reaches more than 95% of ideal color coordinates.

18. The display apparatus of claim 13, wherein the light source module further comprises a power-transmitting substrate electrically connected to the light source driving part, and a plurality of basic clusters is formed on the power-transmitting substrate, and each of the basic clusters includes the first and second light sources.