Interms of the visual sensitivity of the human eye, people are sensitive toyellow and green colors, which means that if the two colors fluctuate slightly,the human eye can sense them. For LED flat panel lamps produced by the samemanufacturer, there should be no significant color difference between differentbatches of products, otherwise it is difficult for users to buy products of thesame color again after a product failure.
Thestandard stipulates that the light color of three randomly selected LED flatpanel lamp samples should be consistent, and the difference in the averagecolor coordinate value CIE 1976 (u'v ') of the three samples should not exceed0.004. At the end of the luminous flux maintenance rate test, the deviation ofthe chromaticity of LED flat panel lamps from the initial value should bewithin 0.007 in the CIE 1976 (u'v ') diagram.
InLED flat panel lamps, the commonly used colors are red, green, blue, white, andyellow. The unit of measurement for color is nm (nanometers). For colorsensitive people, as long as the color fluctuates slightly, they can feel it.To control color difference well, it is necessary to control raw materials. Inorder to avoid differences caused by different color wavelengths, lampmanufacturers should control LED light sources.
Forexample, the green wavelength is 525-530 nm, separated by 5 nm, and the yellowwavelength is 580-585 nm, separated by 5 nm. The red color can be 620-628 nmapart, with a distance of 8 nm. The green wavelength can be felt at a distanceof more than 5 nm, and the red color will not be too obvious even within 8 nm.However, in order to reduce color difference and avoid some uncertain factorscaused by long-term use, such as color drift, it is advisable to control thewavelength of the same color within 2 nm. Therefore, the control of colorindicators is often important because different people have different abilitiesto distinguish colors.
Forwhite light, it is usually indicated by color temperature. Warm white isgenerally 3000-3500K, normal white is 3500-5000K, and cold white is5000K-6500K. Generally, LED color temperatures of packaging manufacturers areseparated by 500K, and there are also LED color temperatures separated by1000K. The internal error requirements for color temperatures in packagingfactories are generally positive or negative 200K. Therefore, LED light sourceswith stable color should be selected, and the production process should bestrictly controlled.
Whentesting the color difference of LED flat panel lamps, it was found that threedifferent flat panel lamp samples were selected for testing, and the colordifference of products from different manufacturers was different, with certaindifferences. Some LED flat panel lamp products had color differences thatexceeded the standard requirements. After analysis, it was believed that themain reason was that the manufacturers failed to conduct careful and effectivescreening when selecting LED light sources, and the optical performanceindicators of each LED were not consistent, This results in different lightemitting colors for different flat panel lamps, resulting in poor visual perceptionwhen installing in a large area, giving people an uncomfortable feeling.
Toimprove this common problem, one is to evaluate suppliers well and selectrelatively fixed manufacturers; The second is to propose product consistencyrequirements to LED suppliers to ensure continuity of supply and relativelyconsistent and stable performance indicators; Third, enterprises themselvesshould also strengthen LED incoming inspection, eliminate LEDs with colordifferences that exceed the requirements, and ensure that the consistency ofLED flat panel lamps produced meets the requirements.
Shenzhen Yenhua Optoelectronics Co.,Ltd. Main production ufoled high bay light, led panel light, street light, tunnel light, flood light,china manufacturer