WO2011069307A1

WO2011069307A1 - Method and system for detecting led's life

Info

Publication number: WO2011069307A1
Application number: PCT/CN2009/075959
Authority: WO
Inventors: 宋义; 苏遵惠; 李英翠; 张俊锋
Original assignee: 深圳帝光电子有限公司
Priority date: 2009-12-11
Filing date: 2009-12-24
Publication date: 2011-06-16
Also published as: CN102096034A

Abstract

A method for detecting a LED's life includes the following steps: obtaining accelerated elements influencing the LED's life (S101); carrying out testing of the LED's life respectively according to each accelerated element influencing the LED's life, and gaining accelerated factors associated with the LED's life (S102); controlling testing of the LED's life respectively in a standard condition and in a synthetic accelerated element according to each accelerated element and accelerated factor, and gaining a testing life of the LED (S103). The method resolves the problem of long testing time of a LED's life and realizes rapid testing. The corresponding detecting system is also provided.

Description

Instruction manual

Title of Invention: A method and system for detecting LED life

Technical field

[1] The present invention belongs to the field of testing technology, and in particular, to a method and system for detecting LED life.

Background technique

[2] LEDs have the advantages of high reliability and long life. In the actual production and development process, it is necessary to evaluate the reliability level of LED chips through life test, and improve the reliability level of LED chips through quality feedback. Guarantee the quality of LED chips. However, in the past, there was no comprehensive national standard and industry standard for LED testing. In production practice, it can only be based on relative parameters. Different manufacturers, users, and research institutions have been controversial, which has led to serious development of the domestic LED industry. The impact, especially the high-power LED street light, its power, high heat, long working hours, life problems are also very prominent. Disclosure of invention

technical problem

[3] An object of the embodiments of the present invention is to provide a method for detecting the life of an LED, which aims to solve the problem that the prior art has no comprehensive national standards and industry standards for testing LEDs, and the test continues for a long time.

[4] Another object of the embodiments of the present invention is to provide a LED life detecting system, which aims to solve the problem that the testing of LEDs in the prior art does not have comprehensive national standards and industry standards, and the testing continues for a long time. .

Technical solution

[5] The embodiment of the present invention is implemented by the method for detecting the life of an LED, and the method includes the following steps:

[6] Obtain the acceleration factors affecting the life of the LED, according to the various acceleration factors affecting the life of the LED

LED life test to obtain an acceleration factor associated with LED lifetime; [7] According to the various acceleration factors and acceleration factors, respectively, the LED life test under the standard conditions and the comprehensive acceleration factor is controlled, and the test life of the LED is obtained.

[8] — A detection system for LED life, including:

[9] The acceleration factor acquisition module is used to obtain an acceleration factor that affects the life of the LED, and respectively performs an LED life test according to each acceleration factor that affects the life of the LED, and obtains an acceleration factor associated with the LED life;

[10] The test life acquisition module is configured to respectively control the LED life test under the standard condition and the comprehensive acceleration factor according to each acceleration factor and the acceleration factor acquired by the acceleration factor acquisition module, and obtain the test life of the LED.

Beneficial effect

[11] In the embodiment of the present invention, an acceleration factor affecting the life of the LED is obtained, and an LED life test is separately performed according to each acceleration factor that affects the life of the LED, and an acceleration factor associated with the LED life is obtained; And the acceleration factor, respectively, control the LED life test under the standard conditions and the comprehensive acceleration factor, obtain the test life of the LED, solve the problem that the LED life test is long, and realize the rapid test.

DRAWINGS

1 is a flowchart showing an implementation of a method for detecting LED life according to a first embodiment of the present invention;

FIG. 2 is a flowchart showing an implementation of a method for detecting LED life according to a second embodiment of the present invention; FIG.

[14] FIG. 3(a) is a graph showing the life test under standard conditions according to an embodiment of the present invention;

[15] FIG. 3(b) is a graph showing the life test under the comprehensive acceleration factor according to an embodiment of the present invention;

[16] FIG. 4 is a flowchart of an implementation of an acceleration factor acquisition method according to an embodiment of the present invention;

[17] FIG. 5 is a graph showing temperature versus life provided by an embodiment of the present invention;

6 is a structural block diagram of a LED life detecting system according to an embodiment of the present invention.

Embodiments of the invention

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[20] In the embodiment of the present invention, obtaining an acceleration factor that affects the life of the LED, according to each of the LEDs affecting the life of the LED The acceleration factor is separately tested for the LED life, and the acceleration factor associated with the LED lifetime is obtained. According to the respective acceleration conditions and the acceleration factor, the LED life test under the standard condition and the comprehensive acceleration factor is respectively controlled, and the LED is obtained. Test life.

[21] FIG. 1 shows an implementation flow of a method for detecting the life of an LED provided by the first embodiment of the present invention, and the specific steps are as follows:

[22] In step S101, an acceleration factor that affects the life of the LED is obtained.

[23] In the embodiment of the present invention, the manner of obtaining the acceleration factor affecting the life of the LED may be a large number of experiments and tests of the basic nature, or may be other methods, and the invention is not limited thereto, wherein the influence of the L ED Acceleration factors for life include, but are not limited to, temperature, current, humidity, voltage, and number of switches.

[24] In step S102, the LED life test is performed according to each acceleration factor that affects the life of the LED, and an acceleration factor associated with the LED lifetime is obtained.

[25] In the embodiment of the present invention, according to the life test of each acceleration factor, a relationship curve between each acceleration factor and the life is obtained, thereby obtaining a function calculation formula of each acceleration factor and life, and thereby deriving and deriving the life of the LED. The associated acceleration factors are described in detail below, and are not described herein, but are not intended to limit the invention.

[26] In step S103, the LED life test under the standard condition and the comprehensive acceleration factor is respectively controlled according to the respective acceleration factors and the acceleration factor, and the test life of the LED is obtained.

[27] In the embodiment of the present invention, the inflection point under the standard condition and the comprehensive acceleration factor is respectively determined, and then the equivalent turn is determined according to the determined inflection point, thereby calculating the life of the LED, which is described in detail in the following embodiments. This is not to be considered, but is not intended to limit the invention.

2 shows an implementation flow of a method for detecting the life of an LED provided by a second embodiment of the present invention, and the specific steps are as follows:

[29] In step S201, an acceleration factor that affects the life of the LED is obtained.

[30] In the embodiments of the present invention, acceleration factors affecting LED life include, but are not limited to, temperature, current, and humidity.

, voltage and number of switches.

[31] In step S202, the LED life test is performed according to each acceleration factor that affects the life of the LED, and an acceleration factor associated with the LED lifetime is obtained.

[32] In step S203, the obtained acceleration factor is deduced and simplified, and an acceleration condition is obtained. [33] In the embodiment of the present invention, through experimental tests, it can be deduced that the acceleration condition is the temperature, current, and humidity obtained by screening the above-mentioned acceleration factors.

[34] In step S204, according to the respective acceleration factors and acceleration factors, respectively, the LED life test under the standard condition and the comprehensive acceleration factor is controlled, and the inflection point under the standard condition and the comprehensive acceleration factor is obtained.

[35] In the embodiment of the present invention, the light decay in a certain period of time is not enough to affect the brightness of the LED, and the brightness of the light is approximately constant. After a period of time, when the light decay begins to increase, the brightness Start to significantly reduce 吋, record this point through the test instrument, defined as the inflection point; the so-called inflection point, that is, the turning point where the brightness begins to decrease significantly, where the inflection point is the turning point on the function curve.

[36] Record the inflection point of the above life test under standard conditions and comprehensive acceleration factors, as shown in Figure 3.

(a) and Figure 3 (b), in the figure, t represents the LED lifetime (daytime), LA, LB respectively indicate the brightness under the above conditions; tA, tA' respectively represent the inflection point; tB, tB' respectively Indicates the end of life under the above conditions, wherein, in Fig. 3 (a) and Fig. 3 (b), when the inflection points tA, tA' appear, the trend of the life test curve is consistent.

[37] In step S205, an equivalent time is determined based on the inflection point, and the LED lifetime is calculated.

[38] In the embodiment of the present invention, according to the inflection point under different test conditions acquired in step S204, the equivalent time corresponding to the inflection point is determined, that is, tA under standard standard conditions and tB under comprehensive acceleration factor, due to tB 'It can be obtained experimentally, therefore, the life of the LED can be calculated, ie:

[39] t = tA' = tA+tA ^/ - tA; so

[41] = ΐΑ +δ (T, F, I) * (tB'- tB); where δ represents the acceleration factor under the corresponding comprehensive acceleration factor under standard conditions. Of course, the above is based on the acceleration condition. For example, the acceleration factors T, F, I, V, and K are examples, and the present invention is not limited thereto.

The above is only one specific embodiment of the present invention, and is not intended to limit the present invention.

[43] As an embodiment of the present invention, FIG. 4 shows an implementation flow of an acceleration factor acquisition method provided by an embodiment of the present invention, and specific implementation steps are as follows:

[44] In step S401, a separate test test is performed on each acceleration factor that affects the life of the LED, and a function calculation formula between each acceleration factor and the brightness of the LED is calculated by a mathematical induction method. [45] In the embodiment of the present invention, various acceleration factors affecting the life of the LED include temperature (T), current (I), humidity (F), voltage (V), and number of switches (K), according to the respective acceleration factors, The L ED light decay test was carried out separately, and the curve shown in Fig. 5 was obtained. Fig. 5 shows the temperature as an example, and the curves of the other four acceleration factors are similar, and are not mentioned here, among which:

[46] In Fig. 5, t and L represent lifetime and luminance, and tl to tn indicate that the luminance threshold is fixed at 70% 吋, respectively, at the lifetimes corresponding to temperatures T1 to Tn.

[47] According to the above experimental curve, the function calculation formula between each acceleration factor and the brightness of the LED is calculated by mathematical induction method, which is specifically:

[48] L1 (τ' t) = α (Τ+ΔΤ, t') ;

[49] L2 (F, t) = β (F+AF, t') ;

[50] L3 (I, t) = τ (ΐ+ΔΙ, t') ;

[51] L4 (V, t) = φ (V + Δν, t') ;

[52] L5 (K, t) = ω (Κ+ΔΚ, ; where α, β, τ, φ, ω are the parameter values of the respective curve functions, T, F, I, V, Κ are under normal conditions Acceleration factor, t is the time to measure the life of the LED under normal conditions, t' is the time to measure the life of the LED under the acceleration factor.

[53] In step S402, a function calculation formula between the respective acceleration factors and the LED brightness is recalculated according to a preset LED brightness threshold value, and a function calculation formula between the LED brightness and each acceleration factor is obtained.

[54] In the embodiment of the present invention, an LED brightness threshold is preset, and the brightness threshold can be generally set to 70%. When the LED brightness is 70%, indicating the end of life, the brightness threshold and each acceleration factor are The calculation formula between the brightness of the LED is calculated, and the following calculation formula is obtained:

[55] t = f (Τ+ΔΤ) t'_; t = f (F+AF) t'_; t = f (ΐ+Δΐ) t';

[56] t = f (V + Δν) t'_; t = f (Κ + ΔΚ) t'.

[57] In step S403, a function calculation formula between the obtained LED luminance and each acceleration factor is superimposed to calculate a function calculation formula between the LED lifetime and the acceleration factor.

In the embodiment of the present invention, the superposition algorithm is applied to superimpose the calculation formula obtained in the above step S402, and the following is obtained:

[59] t ={alf (Τ+ΔΤ) +β1ί (F+AF) +xlf (ΐ+Δΐ) +φ1ί (V+ΔΥ) + Coif (Κ+ΔΚ) } t'_; where AT, AFs ΔΙ, AY. ΔΚ are the determined acceleration factors; the values of α1, β1, τ1, φ1, ωΐ can be calculated by the qualified test, therefore, according to the calculation The parameter value is obtained as a function of the LED lifetime and the acceleration factor:

[61] ΐ = δ (T, F, I, V, K) t', where δ is the acceleration factor, and the acceleration factor is the equivalent factor that changes the effect of the acceleration factor on the lifetime of the LED.

[62] In the embodiment of the present invention, the step of deriving the obtained acceleration factor is simplified, and the step of obtaining the acceleration condition may be specifically expressed as the above t=6 (T, F, I, V, K) _t ' The derivation simplification of the calculation formula is as follows: Separate experiments on the acceleration factors, determine the main decisive factors and secondary factors, remove the secondary factors, and retain the main decisive factors, that is, the above functional relationship is simplified as: t = f (T, F, I) t', the acceleration conditions are temperature, moderation, and drive current. The above is only one embodiment of the present invention and is not intended to limit the present invention.

6 is a block diagram showing the structure of a LED life detecting system according to an embodiment of the present invention. For the convenience of description, only parts related to the embodiment of the present invention are shown.

[64] The acceleration factor acquisition module 11 obtains an acceleration factor that affects the life of the LED, and performs an LED life test according to each acceleration factor that affects the life of the LED, and obtains an acceleration factor associated with the LED lifetime; the test life acquisition module 12 according to the The acceleration factors obtained by the acceleration factor acquisition module 11 and the acceleration factors respectively control the LED life test under the standard conditions and the comprehensive acceleration factors to obtain the test life of the L ED.

In the embodiment of the present invention, the acceleration condition acquisition module 13 deduces and accelerates the acceleration factor obtained by the acceleration factor acquisition module, and obtains an acceleration condition.

[66] As an embodiment of the present invention, the first calculation module 111 performs a separate test test on each acceleration factor that affects the life of the LED, and calculates a function calculation formula between each acceleration factor and the brightness of the LED by a mathematical induction method; The second calculation module 112 recalculates a function calculation formula between the respective acceleration factors calculated by the first calculation module 111 and the LED brightness according to the preset LED brightness threshold value, and obtains the brightness between the LED and each acceleration factor. The third calculation module 113 performs a superposition derivation on the function calculation formula between the LED brightness calculated by the second calculation module 112 and each acceleration factor, and calculates a function calculation formula between the LED lifetime and the acceleration factor. The specific operation is implemented as described in the foregoing method embodiments, and is not described herein, but is not intended to limit the present invention. [67] As another embodiment of the present invention, the inflection point obtaining module 121 respectively controls the LED life test under the standard condition and the comprehensive acceleration factor according to the respective acceleration factors and the acceleration factor, and obtains the standard condition and the comprehensive acceleration factor. The lower inflection point; the life calculation module 122 determines the equivalent time based on the inflection point acquired by the inflection point acquisition module 121, and calculates the lifetime of the LED.

The above is only one embodiment of the present invention, and is not intended to limit the present invention.

[69] In the embodiment of the present invention, an acceleration factor affecting the life of the LED is obtained, and according to various acceleration factors affecting the life of the LED, the LED life test is respectively performed to obtain an acceleration factor associated with the LED life; And the acceleration factor, respectively, control the LED life test under the standard conditions and the comprehensive acceleration factor, obtain the test life of the LED, solve the problem that the LED life test is long, and realize the rapid test.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalents, and improvements made within the spirit and scope of the present invention should be included in the present invention. Within the scope of protection of the invention.

Claims

Claim

[Claim 1] A method for detecting the life of an LED, characterized in that the method comprises the following steps to obtain an acceleration factor affecting the life of the LED, and respectively performing LED life test according to various acceleration factors affecting the life of the LED, obtaining and obtaining the LED Lifetime associated acceleration factor;

According to the various acceleration factors and acceleration factors, the LED life test under the standard conditions and the comprehensive acceleration factor is respectively controlled, and the test life of the LED is obtained.

[Claim 2] The method according to claim 1, wherein after the step of obtaining an acceleration factor associated with the lifetime of the LED, the method further comprises the steps of:

The obtained acceleration factor is deduced and simplified, and the acceleration condition is obtained.

[Claim 3] The method according to claim 1, wherein the step of performing an LED life test according to each acceleration factor that affects the life of the LED, and obtaining an acceleration factor associated with the life of the LED specifically includes:

Performing separate test tests on the various acceleration factors affecting the life of the LED, and calculating a function calculation formula between each acceleration factor and the brightness of the LED by a mathematical induction method; according to a preset LED brightness threshold, the respective acceleration factors are The calculation formula between the brightness of the LED is recalculated to obtain a function calculation formula between the brightness of the LED and each acceleration factor;

The function calculation formula between the obtained LED luminance and each acceleration factor is superposed and deduced, and a function calculation formula between the LED lifetime and the acceleration factor is calculated.

[Claim 4] The method according to claim 1, wherein the controlling the L ED life test under the standard condition and the comprehensive acceleration factor according to the respective acceleration factors and the acceleration factor respectively, obtaining the LED The step of testing the life includes the following steps: controlling the LED life test under the standard condition and the comprehensive acceleration factor according to the respective acceleration factors and the acceleration factor, and obtaining the inflection point under the standard condition and the comprehensive acceleration factor; Based on the inflection point, an equivalent time is determined.

[Claim 5] The method according to claim 1, wherein the acceleration factors affecting the life of the LED include temperature, current, humidity, voltage, and number of switches; the acceleration factor refers to changing the acceleration factor to the LED The equivalent of the impact of life.

[Claim 6] A detection system for LED life, characterized in that the system comprises:

An acceleration factor acquisition module for obtaining an acceleration factor affecting the life of the LED, and performing an LED life test separately according to various acceleration factors affecting the life of the LED to obtain an acceleration factor associated with the life of the LED;

The test life acquisition module is configured to respectively control the LED life test under the standard condition and the comprehensive acceleration factor according to each acceleration factor and the acceleration factor acquired by the acceleration factor acquisition module, and obtain the test life of the LED.

[Claim 7] The system of claim 6, wherein the system further comprises:

An acceleration condition acquisition module is configured to perform derivation and simplification on the acceleration factor obtained by the acceleration factor acquisition module, and obtain an acceleration condition.

[Claim S] The system according to claim 6, wherein the acceleration factor acquisition module comprises:

a first calculation module, configured to perform a separate test test on each acceleration factor that affects the life of the LED, and calculate a function calculation formula between each acceleration factor and the brightness of the LED by a mathematical induction method;

a second calculating module, configured to recalculate a function calculation formula between each acceleration factor and LED brightness calculated by the first calculating module according to a preset LED brightness threshold, to obtain LED brightness and each acceleration factor Function calculation between;

And a third calculating module, configured to perform a superposition derivation on a function calculation formula between the brightness of the LED calculated by the second calculating module and each acceleration factor, and calculate a function calculation formula between the LED life and the acceleration factor.

[Claim 9] The system according to claim 6, wherein the test life acquisition module specifically includes: The inflection point obtaining module is configured to respectively control the LED life test under the standard condition and the comprehensive acceleration factor according to the respective acceleration factors and the acceleration factor, and obtain an inflection point under the standard condition and the comprehensive acceleration factor;

The life calculation module is configured to determine an inflection point according to the inflection point acquisition module, determine an equivalent time, and calculate an LED life.

[Claim 10] The system according to claim 6, wherein the acceleration factors affecting the life of the LED include temperature, current, humidity, voltage, and number of switches; the acceleration factor refers to changing the acceleration factor to the LED The equivalent of the impact of life.