Patent Application
20070146573
The present invention relates to backlight modules and liquid crystal displays, and more particularly to a light emitting diode (LED), a backlight module and a liquid crystal display using the light emitting diode, which is configured to provide scanning effect thereof.
A typical liquid crystal display generally includes a display panel and a backlight module for illuminating the display panel. The backlight module can be classified into non-scanning and scanning backlight module. A non-scanning backlight module illuminates the display panel continuously while the display panel is turned on, but a scanning backlight module is switched on and off alternatively during a period of time while the display panel is turned on. The scanning backlight module includes a plurality of light emitting diodes (LEDs) arranged in a matrix array, which are switched on and off row by row so as to define a scanning effect for preventing the images between two frames of the display panel from image sticking.
Referring to
The substrate 4 is located on the reflective frame 2, and the red, greed, and blue LEDs 8, 10, and 12 are penetrated through the slits 16. Light beams emitted from the LEDs 8, 10, and 12 are confined between two adjacent partitions 6. Each row of LEDs between two adjacent partitions 6 includes a plurality of the red, greed, and blue LEDs 8, 10, and 12. The partition 6 and the substrate 4 is made from or coated with reflective material, such as, silver. Therefore, the light beams emitted from the red, green, and blue LEDs 8, 10, and 12 can be reflected and concentrated between the adjacent partitions 6, and then almost all the light beams are reflected by the substrate 4 and the partition 6 and enter into the diffuser 14. The red, green, and blue LEDs 8, 10, and 12 are in the same row are switched on and off together.
Along with the increasing size of the liquid crystal display, the size of the backlight module and the partitions used thereof also increased. The partitions in larger size are liable to warp due to being pressed by the diffuser 14, thus, the quality of the liquid crystal display is decreased.
Accordingly, what is needed is a backlight module and a liquid crystal display configured to overcome the above-described problems.
An exemplary light emitting diode includes a base, a semiconductor chip, a cover, and two optical layers. The semiconductor chip is formed on the base. The cover is formed on the base and covers the semiconductor chip. The optical layers cover part of a peripheral side of the cover respectively.
A detailed description of embodiments of the present invention is given below with reference to the accompanying drawings.
In the drawings, all the views are schematic.
Referring to
The semiconductor chip 20 is formed on an indentation part of top of the base 18. The reflective frame 22 is formed on the base 18 and covers a part thereof. The transparent cover 28 is formed on the base 18 and the reflective frame 22, and covers the semiconductor chip 20, and a part of the base 18 and reflective frame 22. The first and second pads 24, 26 are connected to the semiconductor chip 20 via the connectors 23 formed on the reflective frame 22 respectively.
The transparent cover 28 includes an upper part (not labeled) and a lower part (not labeled). A profile of the upper part of the cover 28 is substantially similar to a trapezoid, a profile of the lower part of the cover 28 is substantially similar to an ellipse, and the short edges of the upper and lower parts are connected together.
A power supply (not shown) is connected to the light emitting diode 200 via the first and second pads 24, 26, and powers the semiconductor chip 20 through the connectors 23 enabling the semiconductor chip 20 emitting light beams. Light transmittance at a lateral side of the transparent cover 28, which is parallel to the base, is higher than a light transmittance at a top side thereof. Thus, a majority of light beams is irradiated out of the transparent cover 28 from the lateral side thereof.
The optical layers 30 are formed at a peripheral side of the cover 28 defining two intervals (not labeled) which are uncover by the optical layers 30 and are opposite to each other between the optical layers 30. The light beams emitted from the semiconductor chip 20 can only be irradiated out from the cover 28 through the two intervals.
Referring to
The light chip 36 emits light beams outwardly, of which, the light beams 40 is irradiated in two directions toward the intervals, and the light beams 38 are reflected by the reflection layer 34 back into the cover 31. After reflecting several times by the reflection layer 34, the light beams 38 are emitted out from the cover 31 through the intervals between the reflection layers 34 ultimately.
Referring to
The light chip 46 emits light beams 48 outwardly, of which, the light beams 50 are irradiated in two directions toward the intervals, and the light beams 48 are absorbed by the absorption layer 44, and the light 50 is emitted out from the cover 41 through the intervals between the absorption layers 44.
Referring to
The light chip 56 emits radial light beams 58 outwardly, of which, part light beams 60 are irradiated in two directions toward the intervals, and part light beams 58 toward the reflection layers 54 are reflected by the reflection layer 54 back into the cover 51. After reflecting several times by the reflection layer 54, the light beams 38 are emitted out from the cover 51 through the intervals between the reflection layers 54 ultimately.
Referring to
A plurality of LED sets 64 are formed on the substrate 62 at positions according to the slits 76, which includes two red LEDs 68, two green light LEDs 70, and a blue light LED 72 arranged adjacent to each other, and a sequence order thereof is green, red, blue, red, and green LEDs as shown in
The reflective frame 67 is located on the substrate 62, and the LED sets 64 are contained in the corresponding slits 76. The diffuser 80 is arranged on the reflective frame 67, and the liquid crystal panel 82 is arranged on the backlight module 78.
The light beams emitted from the red, green, and blue LEDs 68, 70, and 72 are reflected by the reflective frame 67 and combined together as a white light beam, then transmit toward the diffuser 80. The light beams are scatter uniformly by the diffuser 80, and then enters the liquid crystal panel 82 for displaying images.
In alternative embodiments, the reflection layers 34, 54 is not limited to silver or aluminum, it can also be any kind of material that has light reflection ability. The absorption layer 44 is not limited to opaque resin, but can be any kind of material that has light absorption ability.
The light emitting diodes 300, 400, and 500 arranged on the substrate in lines emits light only in desired directions, therefore, the light emitted from the light emitting diodes arranged in line do not interference others lined light emitting diodes. Thus a step and cost to form the partitions can be saved.
While preferred and exemplary embodiments have been described above, it is to be understood that the invention is not limited thereto. To the contrary, the above description is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 94146365 | Dec 2005 | TW | national |
