CN201391805Y

CN201391805Y - LED backlight light source

Info

Publication number: CN201391805Y
Application number: CN200920142416U
Authority: CN
Inventors: 方文卿; 刘卫华
Original assignee: Lattice Power Jiangxi Corp
Current assignee: Lattice Power Jiangxi Corp
Priority date: 2009-04-17
Filing date: 2009-04-17
Publication date: 2010-01-27
Anticipated expiration: 2019-04-17

Abstract

The utility model provides an LED backlight light source which is provided with an RGB three primary color lighting unit and can achieve the driving to driver ICs through lower current type LEDs; the LED backlight light source comprises a lighting unit and a PCB, wherein the lighting unit is fixed on the PCB; the lighting unit adopts an RGB lighting unit and is made up of three high-power color light units, including a blue light unit, a red light unit and a green light unit, and the three color light units are connected with the respective colored light LED constant current driver together; at least one colored light unit in the blue light unit and the red light unit is made up of a plurality of low power LED groups, and the low power LEDs are electrically connected with each other in series. The provided scheme ensures that the LED backlight with the RGB three primary colors is low in cost and simple in circuit structure.

Description

The LED-backlit light source

Technical field

The utility model relates to a kind of LED-backlit technology, is mainly used in the liquid crystal display of LED-backlit.

Background technology

The back light unit of LED-backlit liquid crystal display normally adopts monochromatic great power LED to add the white point light source that the fluorescent material encapsulation is made.It still is that all synthetic not as the RGB three-primary colours white light of colourity is effective that monochromatic LED adds the white point light source brightness that fluorescent material makes.

In Chinese patent literature, Chinese patent application number is 200710063162, to be called " a kind of LED intednsity circuit and backlight of LCD ", open date be on August 8th, 2007 to name.What this patent documentation was put down in writing is the LED-backlit source that a kind of monochromatic excitation goes out white light.

It is the back light of the led chip of growth substrates as liquid crystal with sapphire or carborundum that prior art is all selected for use powerful.Its electric current generally can reach the hundreds of milliampere, if make the white light backlight of RGB three-primary colours, then general cheapness commonly used drives chip, the LED of the TLC5941 that produces as Texas Instrument drives chip, it is 80mA that each passage maximum can provide electric current, and it just can't drive this great power LED backlight at all.In order to drive big like this LED, then needing to use to provide the driving of bigger electric current chip, and such chip cost is higher, but also can cause on the pcb board electric current very big, and what the lead of the last plating of PCB can be very is wide, and can produce a lot of heats.

Now most widely used be monochromatic light inspire white light LED because as long as it is chained together, by a switch chip that is connected in the LED lamp string road, simple control just can realize effect backlight.And the RGB three-primary colours LED-backlit of better effect backlight, because the restriction of actuation techniques, its application development stagnates always.

Summary of the invention

Problem to be solved in the utility model is: a kind of LED-backlit light source is provided, and this back light has RGB three-primary colours luminescence unit, and can realize driving with the LED driving chip of small electric stream type.

In order to solve the problems of the technologies described above, the utility model proposes a kind of LED-backlit light source, comprise luminescence unit and PCB, luminescence unit is fixed on the PCB;

Described luminescence unit is the RGB luminescence unit, is made of blue light unit, three kinds of powerful coloured light of red light unit and green glow unit unit, and three kinds of coloured light unit link together with separately coloured light LED constant-flow driver;

Have at least a kind of coloured light unit to be made up of a plurality of low-power LEDs in described blue light unit, the green glow unit, the electricity of a plurality of low-power LEDs is cascaded.

Preferably: described low-power LED is that growth substrates is the stagged electrode structure of silicon substrate.Growth substrates is the relative sapphire of the LED of silicon substrate, and its cost of material is lower, and structure is stagged electrode structure, and this structure only need be welded a contact conductor to LED, makes the electrode bonding wire easier, can improve quality.

Preferably: described low-power LED comprises substrate, and described substrate is a translate substrate, and translate substrate is silicon substrate or metal substrate.If led chip is without upside-down mounting, then growth substrates is the substrate on the final chip; If through upside-down mounting, growth substrates will be stripped from, the substrate on the final chip is a translate substrate.Use inverted structure to help improving the light emission rate of chip.The chip of process upside-down mounting and translate substrate are conductor, and chip all is a stagged electrode structure.

Preferably: described blue light unit, two kinds of coloured light unit, green glow unit all are made up of the low-power LED of stagged electrode structure.Can be blue chip with silicon as the LED of growth substrates, also can be the green glow chip, so blue light unit and green glow unit can be selected described low-power LED simultaneously for use, also can select described low-power LED for use in only a kind of coloured light unit.

Preferably: described low-power LED encapsulates, is fixed on the described PCB by a glue mode; Have in the coloured light unit of a plurality of low-power LEDs, two adjacent low-power LEDs are cascaded by metal lead wire, and the end that goes between is connected on the electrode of one of them low-power LED, and the other end of lead-in wire is connected with the bottom electrical of another low-power LED.

Preferably: described blue light unit, red light unit, green glow unit are encapsulated in the support with integrated circuit together, and support is welded on the described PCB.

Preferably: at least a coloured light unit is composed in series by 5 low-power LEDs in described blue light unit, green glow unit, the red light unit.

Preferably: described blue light unit, three kinds of coloured light unit of red light unit and green glow unit are composed in series by 5 low-power LEDs respectively.15 low-power LEDs can be encapsulated in the support with integrated circuit altogether, and support is welded on the PCB, also can put glue and be encapsulated on the pcb board.

The beneficial effects of the utility model are as follows:

Compared to existing technology, it is a kind of with the scheme of low-power LED chip as liquid crystal screen backlight that the utility model provides, it is that the low-power LED chip of growth substrates is as backlight that this scheme is selected for use with silicon, a plurality of low-power LEDs are cascaded, the electric current that each low-power LED needs is very little, can use maximum current to have only tens milliamperes little electric current LED to drive the luminescence unit of chip drives RGB three-primary colours like this; Do not need to electroplate wide lead on the whole like this PCB, and can keep normal caloric value, it has realized the low cost of RGB three-primary colours LED-backlit and simple circuit structure more.

Description of drawings

Fig. 1 is the encapsulating structure schematic diagram of blue light of the present utility model unit.

Fig. 2 is the structure chart of support.

Fig. 3 is a circuit structure schematic diagram of the present utility model.

Identifier declaration among the figure:

Luminescence unit 1, LED drives chip 2, and PCB 3, metal lead wire 4, LED electrode 5, electrode metal layer 6, lead 7, epoxy resin layer 8, support 9;

Blue light unit 10, green glow unit 20, red light unit 30;

First blue-ray LED, 101, the second blue-ray LEDs, 102, the three blue-ray LEDs, 103, the four blue-ray LEDs, 104, the five blue-ray LEDs 105.

The specific embodiment

The utility model provides a kind of LED-backlit light source, referring to embodiment illustrated in fig. 3.

The luminescence unit 1 of this LED-backlit light source is the RGB unit, shown in the frame of broken lines among Fig. 3.Luminescence unit 1 mainly is made up of blue light unit 10,

green glow unit

20 and 30 3 kinds of powerful coloured light of red light unit unit, and they lump together the white light or the coloured light that can send colourity and adjustable brightness.Blue light unit 10, green glow unit 20 and red light unit 30 can be interspersed on PCB.

Blue light unit 10, green glow unit 20 are to form by the low-power LED that five growth substrates are silicon substrate, stagged electrode structure.Substrate on the low-power LED of stagged electrode structure is a translate substrate, and translate substrate is silicon substrate or metal substrate.

Among Fig. 1, blue light unit 10 is made up of first blue-ray LED 101, second blue-ray LED 102, the 3rd blue-ray LED 103, the 4th blue-ray LED 104, the 5th blue-ray LED 105.There is electrode 5 each blue-ray LED upper end, and there is electrode metal layer 6 lower end.Electrode 5 and electrode metal layer 6 are as positive and negative two electrode terminals of LED.Connect conducting by metal lead wire 4 between adjacent two blue-ray LEDs, metal lead wire 4 is received on the electrode metal layer 6 of a back blue-ray LED from the electrode 6 of previous blue-ray LED.Electrode metal layer 6 is plated on the PCB 3.Blue light unit 10 connects LED by the lead on the PCB 37 and drives chip 2.Blue light unit 10 is fixed on the PCB3 by epoxy resin layer 8 encapsulation.Green glow unit 20, red light unit 30 and blue light unit 10 are in like manner.Blue light unit 10, green glow unit 20 and red light unit 30 can constitute a luminescence unit with epoxy encapsulation together.

Above-mentioned blue light unit and green glow unit can also be the silicon substrate LED chip that blue light unit or green glow unit are selected vertical stratification for use except the silicon substrate LED of selecting vertical stratification simultaneously for use, and another one coloured light unit is the LED of Sapphire Substrate.

Referring to Fig. 2, the following summary of another embodiment of the present utility model:

Blue light unit, red light unit, green glow unit one are reinstated packaging plastics such as epoxy resin or silica gel and are encapsulated in the support 9 with integrated circuit, and support 9 is welded on the PCB 3.

In actual applications, driving the chip drives blue-ray LED with the LED of the TLC5941 that selects Dezhou electronics for use is example.

TLC5941 has 28 pins, it is one 16 LED channels constant-flow driver, can drive 16 (string) LED simultaneously, every passage maximum drive ability 80mA, each passage can carry out 4096 grades of brilliance controls according to the value of inner brightness register by the PWM mode, the length of inner each passage brightness register is 12, and the maximum of drive current can be set by off chip resistor, and the switch control voltage of maximum 17V can be provided.

A TLC5941LED drives the chip connection and can connect 16 blue light unit at most, each blue light unit is composed in series by 5 small-power blue-ray LEDs, the electric current of each blue light low-power LED is that 20mA, voltage are 3V, then a TLC5941LED driving of electric current chip need be 3V * 5=15V for four blue light unit provide port voltage, 15V＜17V.TLC5941LED drives the total current 20mA * 16=320mA of chip.

For red-light LED and green light LED, if the total voltage of 5 low-power LEDs that are cascaded greater than 17V, can be by reducing to connect quantity or suitably improve the mode that LED drives the chip specification and solve.

Claims

1, a kind of LED-backlit light source comprises luminescence unit and PCB, and luminescence unit is fixed on the PCB, it is characterized in that:

2, LED-backlit light source according to claim 1 is characterized in that: described low-power LED is that growth substrates is the stagged electrode structure of silicon substrate.

3, LED-backlit light source according to claim 1, it is characterized in that: described low-power LED comprises substrate, and described substrate is a translate substrate, and translate substrate is silicon substrate or metal substrate.

4, LED-backlit light source according to claim 1 is characterized in that: described blue light unit, two kinds of coloured light unit, green glow unit all are to be composed in series by a plurality of described low-power LEDs.

5, according to each described LED-backlit light source in the claim 1 to 4, it is characterized in that: described low-power LED encapsulates, is fixed on the described PCB by a glue mode; Have in the coloured light unit of a plurality of low-power LEDs, two adjacent low-power LEDs are cascaded by metal lead wire, and the end that goes between is connected on the electrode of one of them low-power LED, and the other end of lead-in wire is connected with the bottom electrical of another low-power LED.

6, according to each described LED-backlit light source in the claim 1 to 4, it is characterized in that: described blue light unit, red light unit, green glow unit are encapsulated in the support with integrated circuit together, and support is welded on the described PCB.

7, according to each described LED-backlit light source in the claim 1 to 4, it is characterized in that: at least a coloured light unit is composed in series by 5 low-power LEDs in described blue light unit, green glow unit, the red light unit.

8, LED-backlit light source according to claim 7, it is characterized in that: described blue light unit, three kinds of coloured light unit of red light unit and green glow unit are composed in series by 5 low-power LEDs respectively, 15 low-power LEDs are encapsulated in the support with integrated circuit, and support is welded on the PCB.

9, LED-backlit light source according to claim 5 is characterized in that: described blue light unit, three kinds of coloured light unit of red light unit and green glow unit are composed in series by 5 low-power LEDs respectively.