Design of a highly efficient LED-based bicycle head lamp with additional ground illumination

A novel design of phosphor-converted, white light emitting diode-based bicycle head lamp producing sufficient illuminance on the target to meet the K-mark regulations and additional illumination on the ground is proposed and demonstrated. The phosphor-converted, white light emitting diode has a power demand of 2.5 W, while the novel design offers a maximum illuminance of 30 lux at the HV point, and illuminances larger than 3 lux across the first 7 m on the ground. The optical utilisation factor for the target illumination is 30% and for the ground is 44%. It means that around 74% of the luminous flux emitted by the phosphor-converted, white, light emitting diodes is utilised. This novel and highly efficient bicycle head lamp provides safer illumination for bicycle riders.