CN202032395U

CN202032395U - Back light source with light emitting diode (LED) module and LED module

Info

Publication number: CN202032395U
Application number: CN2011200673484U
Authority: CN
Inventors: 杨丽敏; 徐欣荣; 孙平如
Original assignee: Shenzhen Jufei Optoelectronics Co Ltd
Current assignee: Shenzhen Jufei Optoelectronics Co Ltd
Priority date: 2011-03-15
Filing date: 2011-03-15
Publication date: 2011-11-09
Anticipated expiration: 2021-03-15

Abstract

The utility model discloses a back light source with a light emitting diode (LED) module. The LED module comprises a base plate and LEDs arranged on the base plate, wherein the LEDs comprise first type LEDs and second type LEDs, the base plate comprises a center region and an edge region, the first type LEDs are arranged in the center region, the second type LEDs are arranged in the edge region, and in addition, the forward voltage of the first type LEDs is lower than the forward voltage of the second type LEDs. The utility model also discloses the LED module. The temperature difference between the center region and the edge region of the base plate is reduced through the back light source and the LED module.

Description

Backlight and led module with led module

Technical field

The utility model relates to a kind of backlight and led module with led module.

Background technology

LCDs is passive light-emitting display device, need provide backlight to work.At present, the backlight of LCDs has two kinds, is respectively to adopt the backlight of CCFL (cold-cathode fluorescent) and the backlight of LED.The LED-backlit source because possess that fine definition, energy-conserving and environment-protective, life-span are long, characteristics such as super wide colour gamut and ultra-thin outward appearance and replace the CCFL backlight gradually, become the backlight that LCDs mainly adopts.

Being mainly used in luminous parts in the LED-backlit source is led modules, and described led module comprises that numerous on the PCB substrate of PCB substrate and dense distribution are used for luminous LED.Wherein, all LED adopts same forward voltage range, is such as voltage forward: 3.1～3.2V.There are the following problems for this structure:

When the operate as normal of LED-backlit source, adopt the temperature of thermal infrared imager test PCB substrate each several part.The temperature of test result demonstration PCB substrate is successively decreased to fringe region by the central area, and especially the temperature difference of central area and fringe region can reach more than 8 ℃.Yet the temperature of PCB substrate will directly influence the performance of LED.Usually the temperature of PCB substrate is high more, and the junction temperature of LED is also high more, and the luminous efficiency of LED is then low more.Correlative study shows that also when the junction temperature of LED is elevated to 75 ℃, its brightness will reduce to 80%; During to 125 ℃, be reduced to 60%; During to 175 ℃, be reduced to 40%.

Therefore, how the temperature difference of balance PCB substrate each several part is the problem that those skilled in the art are devoted to solve always.The analysis showed that, PCB substrate center zone and fringe region exist the reason of the big temperature difference to be, be distributed on the PCB substrate to the LED equi-spaced apart, and all LED adopt same forward voltage range, the heat that the LED work of fringe region produces spreads to zone line, causes the temperature of central area higher, and the temperature difference of central area and fringe region is bigger, cause the light efficiency of center LED to be significantly less than the light efficiency of edge LED, reduced the reliability of center LED simultaneously.

Summary of the invention

The main technical problems to be solved in the utility model is, a kind of backlight and led module with led module is provided, and can reduce the central area of substrate and the temperature difference of fringe region, improves the reliability of center LED.

For solving the problems of the technologies described above, the utility model provides a kind of backlight with led module, described led module comprises substrate and the LED that is installed on the described substrate, described substrate comprises central area and fringe region, described LED comprises the first kind LED and the second class LED, described first kind LED is installed in described central area, and the described second class LED is installed in described fringe region, and the forward voltage of described first kind LED is less than the forward voltage of the described second class LED.

Described substrate is PCB substrate or ceramic substrate or metal substrate.

Described substrate is circular or square or oval.

Described LED is installed on the described substrate equally spacedly.

Equidistantly arrange between the described first kind LED, and the middle mind-set edge direction of the forward voltage between the described first kind LED from described central area increases progressively with 0.1V～0.2V.

Equidistantly arrange between the described second class LED, and the forward voltage between the described second class LED increases progressively with 0.1V～0.2V from the middle mind-set edge direction of described fringe region.

Be the mode of being connected in series between described all LED that are installed on the substrate.

Be connected mode in parallel after the series connection earlier between described all LED that are installed on the substrate, and first kind LED is dispersed in each parallel branch.

The mode that described LED adopts the surface to paste is mounted on the described substrate.

A kind of led module, comprise substrate and and be installed in LED on the described substrate, described substrate comprises central area and fringe region, described LED comprises the first kind LED and the second class LED, described first kind LED is installed in described central area, the described second class LED is installed in described fringe region, and the forward voltage of described first kind LED is less than the forward voltage of the described second class LED.

The beneficial effects of the utility model are: the forward voltage of LED (first kind LED) that is distributed in the central area is less than the forward voltage of the LED that is distributed in fringe region (the second class LED).During led module work, the heat that the heat that the central area produces will produce less than fringe region, even heat is assembled to the central area, also can reduce the temperature difference of central area and fringe region, make the heat of whole base plate more even, thereby the centre of equilibrium is regional and the light efficiency of fringe region, makes the more even light emission of backlight, has improved center LED reliability.

Description of drawings

Fig. 1 is the led module structural representation of a kind of embodiment of the utility model;

Fig. 2 is the circuit connection diagram of the LED of a kind of embodiment of the utility model;

Fig. 3 is the led module structural representation of the employing circular substrate of a kind of embodiment of the utility model;

Fig. 4 is the led module structural representation of the employing square substrate of a kind of embodiment of the utility model.

The specific embodiment

In conjunction with the accompanying drawings the utility model is described in further detail below by the specific embodiment.

Please refer to Fig. 1 to Fig. 4, a kind of led module 1 comprises substrate 2 and LED 3, and LED 3 is installed on the substrate 2, and LED3 comprises the first kind LED and the second class LED.Substrate 2 comprises central area 21 and fringe region 22, and the forward voltage of first kind LED that is installed in central area 21 is less than the forward voltage of the second class LED that is installed in fringe region 22.

Wherein, substrate 2 is by having good electrical conductivity and the thermal conductivity material is made, such as being PCB substrate or ceramic substrate or (aluminium) metal substrate, its shape can be circular, square or oval or other shape, when being circular or square, its led module structure is respectively shown in Fig. 3 and 4.Substrate 1 can also be provided with other zone except central area 21 and fringe region 22, such as the transitional region between central area 21 and fringe region 22, transitional region is installed the 3rd class LED, the forward voltage of the 3rd class LED is between the first kind LED and the second class LED, promptly greater than the forward voltage of first kind LED and less than the forward voltage of the second class LED.If central area 21 and fringe region 22 only are set on substrate 2, then preferably the area in two zones evenly is provided with, such as Fig. 3 and Fig. 4 for two structure charts when regional evenly are set on substrate.Modes such as employing surface stickup are mounted on high-brightness white-light LED 3 on the substrate 2 equally spacedly.

Above-mentioned led module is in backlight during as light emitting source, the forward voltage of the LED of central area 21 (first kind LED) is less than the forward voltage of the LED (the second class LED) of fringe region 22, the heat that central area 21 is produced is few, though it will be subjected to assembling from fringe region 22 influence of the heat that comes, but this just in time balance the temperature difference of fringe region 22 and central area 21, the heat of whole base plate 2 is distributed more evenly, thereby improve the uniformity of luminance of led module and the reliability and the life-span of led chip.

In the said structure,, its forward voltage is set according to its position in this zone to the led chip in the same area.Such as, in the same area, be in the LED of center, adopt the low forward LED of voltage; Be in the LED of marginal position, adopt the LED of higher forward voltage.Concrete mode can be, for central area 21, the forward voltage of the first kind LED that distributes on it from the middle mind-set edge direction of central area 21 increase progressively with 0.1V～0.2V and each first kind LED between equidistantly arrange.For fringe region 22, the forward voltage of the second class LED that distributes on it increases progressively with 0.1V～0.2V and each second class LED equidistantly arranges from the middle mind-set edge direction of fringe region 22.By this kind structure, in the zone, balance is carried out in the distribution of heat.

In the said structure, be distributed in connected modes such as adopting series connection or series connection back parallel connection earlier between all LED 3 on the substrate 2.In a kind of enforcement examination, as shown in Figure 1,15 LEDs 3 adopt the mode of series connection to connect, and five first kind LED that wherein are positioned at central area 21 adopt the low forward LED of voltage, and 10 second class LED that are positioned at fringe region adopt the LED of higher forward voltage.In another embodiment, as shown in Figure 2, LED 3 always has 15, and 5 is that one group of series connection back is in parallel, forms three parallel branches, be respectively parallel branch 40, parallel branch 41 and parallel branch 42, five first kind LED that will be positioned at the central area are distributed in above three parallel branches, such as, wherein two are arranged in parallel branch 40, have two to be arranged in parallel branch 41 in remaining, last is arranged in parallel branch 42.This kind structure is distributed to the first kind LED in the central area 21 in the different parallel branches, reduces the heat generation amount of central area, improves the heat distribution uniformity of substrate 2, thereby improves the uniformity of luminance of led module.

The led module of said structure all can be used for backlight as light emitting source.

Above content be in conjunction with concrete embodiment to further describing that the utility model is done, can not assert that concrete enforcement of the present utility model is confined to these explanations.For the utility model person of an ordinary skill in the technical field, under the prerequisite that does not break away from the utility model design, can also make some simple deduction or replace, all should be considered as belonging to protection domain of the present utility model.

Claims

1. backlight with led module, described led module comprises substrate and the LED that is installed on the described substrate, it is characterized in that, described substrate comprises central area and fringe region, described LED comprises the first kind LED and the second class LED, described first kind LED is installed in described central area, and the described second class LED is installed in described fringe region, and the forward voltage of described first kind LED is less than the forward voltage of the described second class LED.

2. the backlight with led module as claimed in claim 1 is characterized in that, described substrate is PCB substrate or ceramic substrate or metal substrate.

3. the backlight with led module as claimed in claim 1 is characterized in that, described substrate is circular or square or oval.

4. the backlight with led module as claimed in claim 1 is characterized in that described LED is installed on the described substrate equally spacedly.

5. as each described backlight in the claim 1 to 4 with led module, it is characterized in that, equidistantly arrange between the described first kind LED, and the middle mind-set edge direction of the forward voltage between the described first kind LED from described central area increases progressively with 0.1V～0.2V.

6. ask each described backlight in 1 to 4 as right with led module, it is characterized in that, equidistantly arrange between the described second class LED, and the forward voltage between the described second class LED increases progressively with 0.1V～0.2V from the middle mind-set edge direction of described fringe region.

7. as each described backlight in the claim 1 to 4, it is characterized in that, be the mode of being connected in series between described all LED that are installed on the substrate with led module.

8. as each described backlight in the claim 1 to 4, it is characterized in that, be connected mode in parallel after the series connection earlier between described all LED that are installed on the substrate, and first kind LED is dispersed in each parallel branch with led module.

9. as having the backlight of led module in the claim 1 to 4 as described in each, it is characterized in that the mode that described LED adopts the surface to paste is mounted on the described substrate.

10. led module, comprise substrate and and be installed in LED on the described substrate, it is characterized in that, described substrate comprises central area and fringe region, described LED comprises the first kind LED and the second class LED, described first kind LED is installed in described central area, and the described second class LED is installed in described fringe region, and the forward voltage of described first kind LED is less than the forward voltage of the described second class LED.