Importance

Loading Importance Indicators...

Abstract

According to the present invention there is provided a method of operating a laser comprising the steps of; defining an intensity value (K_{VIDEO red}, K_{VIDEO green}, K_{VIDEO blue}) for a light beam which is to be output from the laser; determining if the defined intensity value is greater than, or less than, a threshold intensity (K_{TH red}, K_{TH green}, K_{TH blue}) for the laser, wherein the threshold intensity is the intensity of the light which is output from the laser when the input current to the laser is equal to the threshold current (I_{TH red}, I_{TH green}, I_{TH blue}) of the laser, wherein the threshold current (I_{TH red}, I_{TH green}, I_{TH blue}) of the laser is an input current value below which the laser would operate in its light emitting region and equal to, or above which, the laser will operate in its laser region; operating the laser using current from at least a DAC current source if the defined intensity value (K_{VIDEO red}, K_{VIDEO green}, K_{VIDEO blue}) is greater than the threshold intensity (K_{TH red}, K_{TH green}, K_{TH blue}), wherein the DAC current source operates the laser by inputting to the laser a continuous current which has an amplitude which is greater than the threshold current (I_{TH red}, I_{TH green}, I_{TH blue}) of the laser, and which has an amplitude such that the laser is operated to output a light beam which has an intensity equal to the defined intensity value (K_{VIDEO red}, K_{VIDEO green}, K_{VIDEO blue}); and operating the laser using current from the PWM current source only, if the defined intensity value (K_{VIDEO red}, K_{VIDEO green}, K_{VIDEO blue}) is less than the threshold intensity (K_{TH red}, K_{TH green}, K_{TH blue}), wherein the PWM current source operates the laser by inputting to the laser a current which has an amplitude which is at least equal to the threshold current value (I_{TH red}, I_{TH green}, I_{TH blue}) of the laser, and wherein the duration of time over which the PWM current source inputs its current to the laser is such that the laser is operated to output a light beam which has an intensity equal to the defined intensity value (K_{VIDEO red}, K_{VIDEO green}, K_{VIDEO blue}). There is further provided a corresponding laser driver.

Loading the Abstract Image...

First Claim