Driving device for driving a light emitting device with stable optical power
AssigneeNational Chi Nan University
InventorsTai-Ping SUN, Hsiu-Li SHIEH, Chi-Neng HO
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Abstract
A driving device is adapted to drive a light emitting device with stable optical power, and includes a feedback driving circuit, and a pulse wave generating circuit. The feedback driving circuit provides a driving current that is associated with a pulse-wave signal to the light emitting device, and outputs a feedback signal. The pulse wave generating circuit includes an analog-to-digital converter outputting a digital feedback signal according to the feedback signal, and a controller outputting the pulse-wave signal according to the digital feedback signal.
Claims11
A driving device adapted to drive a light emitting device with stable optical power, the light emitting device having a forward voltage when driven with current, the forward voltage having an inverse relationship with an ambient temperature, said driving device comprising:
- a feedback driving circuit to be coupled to the light emitting device, disposed to receive a pulse-wave signal, and configured to provide a driving current to the light emitting device, and to output a feedback signal, the driving current being a pulse wave in magnitude and having an average magnitude proportional to a duty cycle of the pulse-wave signal;
- and
- a pulse wave generating circuit including:
- an analog-to-digital (A/D) converter coupled to said feedback driving circuit for receiving the feedback signal, and configured to output a digital feedback signal according to the feedback signal;
- and
- a controller coupled to said A/D converter for receiving the digital feedback signal, and configured to output the pulse-wave signal according to the digital feedback signal.
Dependencies are inferred from the claim text.