Definition

– Flicker
Perception of visual unsteadiness induced by a light stimulus whose luminance or spectral distribution fluctuates with time, for a static observer in a static environment. ~0-80Hz

– Phantom Array

Perception of a spatially extended series of light spots when making a saccade (image transition across the retina) across a light source that fluctuates with time. ~50Hz-2kHz

– Stroboscopic Effects

Change in motion perception induced by a light stimulus whose luminance or spectral distribution fluctuates with time, for a static observer in a non-static environment. ~50Hz-2kHz

– Temporal Light Artifact
An undesired change in visual perception, induced by a light stimulus whose luminance or spectral distribution fluctuates with time, for an observer in a certain environment.

Sources of TLA

1. Source voltage changes (noise)
2. Externally coupled noise sources
3. Dimmer phase angle instabilities (when dimming)
4. Driver instabilities
5. Driver (intended) operation

Current flicker metrics

• Simple

– Percent Flicker
– Flicker Index

• Complex

– RPI LRC ASSIST
– IEC PST
– SVM
– IEEE