IEC 62504-2014 pdf – General lighting – Light emitting diode (LED) products and related equipment – Terms and definitions.
1 Scope This International Standard IEC 62504 is of assistance in the common understanding of terms and definitions, relevant for general lighting with LED technology. The terms included are those already available in IEC LED standards or used in manufacturers’ literature. This standard provides descriptive terms (like “LED light sources”) and measurable terms when modified from IEC 60050-845 (like “colour rendering index”). NOTE Annex A gives overviews of LED package design and systems composed of LED light sources and controlgear. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050 (all parts), International Electrotechnical Vocabulary (available at <http://www.electropedia.org>). CIE Technical Report 1 27:2007, Measurement of LEDs 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60050-845, with the exception of those modified below, and the following apply. 3.1 ageing preconditioning period of the LED light source before initial values are taken
3.3 apparent source for a given evaluation location of the retinal hazard, the real or virtual object that forms the smallest possible retinal image (considering the accommodation range of the human eye) Note 1 to entry: The accommodation range of the eye is assumed to be variable from 1 00 mm to infinity. The location of the apparent source for a given viewing position in the beam is that location to which the eye accommodates to produce the most hazardous retinal irradiance condition. Note 2 to entry: This definition is used to determine, for a given evaluation position, the location of the apparent origin of laser radiation in the wavelength range of 380 nm to 1 400 nm. In the limit of vanishing divergence, i.e. in the case of a well collimated beam, the location of the apparent source goes to infinity. [SOURCE: IEC 60825-1 , 3.1 0, modified – In the note 2 to entry the value of the wavelength range is changed from ‘400 nm to 1 400 nm’ to ‘380 nm to 1 400 nm’.] 3.4 beam angle angle between two imaginary lines in a plane through the optical beam axis, such that these lines pass through the centre of the front face of the lamp and through points at which the luminous intensity is 50 % of the centre beam intensity Note 1 to entry: Beam angle is expressed in degrees ( ° ). Note 2 to entry: This angle is a full angle measure, not a half angle measure. [SOURCE: IEC TR 61 341 , 2.4, modified, – The notes to entry are added.] 3.5 bin restricted range of LED performance characteristics used to delimit a subset of LED dies or LED packages near a nominal LED performance as identified by chromaticity, photometric, radiometric and/or electrical characteristics
3.6.3 control unit of the controlgear electronic device, being part of the controlgear, responsible for controlling the electrical energy to the LED light sources as well as colour mixing, response to depreciating luminous flux and further performance features Note 1 to entry: In LEDsi modules, the control unit of the controlgear is on board of the LED module and separate from the power supply of the controlgear. 3.7 dominant wavelength <of a colour stimulus> λ d wavelength of the monochromatic stimulus that, when additively mixed in suitable proportions with the specified achromatic stimulus, matches the colour stimulus considered in the CIE 1 931 x,y chromaticity diagram Note 1 to entry: Dominant wavelength is expressed in nanometres (nm). Note 2 to entry: In the case of purple stimuli, the dominant wavelength is replaced by the complementary wavelength. Note 3 to entry: For characterising LED light sources the reference achromatic stimulus should be illuminant E which has the chromaticity coordinates x E = 0,3333, y E = 0,3333. Note 4 to entry: A value for dominant wavelength should only be stated for LED light sources emitting coloured light. For LED light sources emitting white light no meaningful value for dominant wavelength can be given. Note 5 to entry: Figure 1 2 in CIE 1 27:2007 shows the relationship between chromaticity coordinate C of LED light sources and value of dominant wavelength D. N is the chromaticity coordinate of achromatic stimulus E. Note 6 to entry: Deviating from the peak wavelength, the dominant wavelength determines perceived colour. [SOURCE: IEC 60050-845:1 987, 845.03.44, modified – The words ‘in the CIE 1 931 x,y chromaticity diagram’ and the notes to entry 3 to 6 have been added; CIE S 01 7/E:201 1 , 1 7- 345, modified – The notes to entry 3 to 6 have been added.]