The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 29, 2008
Filed:
May. 29, 2003
Kazuhito Tsuchida, Kanagawa, JP;
Junji Saito, Tokyo, JP;
Kazuo Sudo, Kanagawa, JP;
Abstract
A light emitting element drive apparatus capable of always outputting the lowest voltage satisfying the drive conditions and having a high light emitting efficiency and a low power loss, and a portable apparatus using the same, comprising a LED drive apparatusto which LEDs-to-n of different drive voltages required for emitting light are connected in parallel and driving one or more LEDs, wherein the LED drive apparatushas drive circuits-to-n connected to the corresponding LEDs among a plurality of LEDs and driving the corresponding LEDs with luminances based on set values and power supply circuitsandfor deciding a drive voltage value required for the highest light emission among one or more LEDs driven to emit light based on drive states of drive circuits (for example terminal voltages of the current source) and supplying a drive voltage having at least the decided value to a plurality of LEDs in parallel.