Idemitsu products and maintenance of light is LED lighting product life indicators important concern factor. In addition, LED lighting product characteristics and application areas to consider starting life of the product evaluation, there are some differences, for example, in addition to lumen maintenance in addition, LED lighting products and maintain color quality, etc., our group also to carry out research work in this area with a view of the performance and lifetime of LED lighting products do a more reasonable assessment. Table 1 also gives the relevant country or region in the LED lighting product life-related indicators considerations.
The United States in 2011 released the IES TM21 “ProjectingLong Term Lumen Maintenance of LED Light Sources” ‖ standard, used in LED packaging, LED arrays, external drive control of the LED module. The standard provides a use of IES LM80 test data to an exponential decay of flux decay model LED light source projected lumen maintenance approach.
① The intervals of not more than 1000h flux test, the test time is not less than 6000h;
② The 0h flux as a benchmark, calculated at each time point lumen maintenance;
③ The exponential decay model φ (t) = β · exp (- αt) lumen maintenance trend curve fitting, if the test does not exceed the total time 10000h, take the last data point for the fitting curve 5000h original data; if the total test time More than 10000h, then take the total test time is after the 50% test point fitting curve raw data;
④ According to the result of curve fitting calculations α and β values??, on the basis on the basis of L70 = ln (β / 0. 7) / α calculating light L70 life (life time if projected from the total test time is greater than 5.5 times (or six times), then take the total test time of 5.5 times (or six times) for the projected life time)