US 8,941,581 B2 · Light emitting element drive apparatus and portable apparatus using same

Abstract

A light emitting element drive apparatus capable of outputting the lowest voltage satisfying drive conditions and having high light emitting efficiency and low power loss, and a portable apparatus using the same, comprising an LED drive apparatus to which LEDs of different drive voltages required for emitting light are connected in parallel and driving one or more LEDs, wherein the LED drive apparatus 10 has drive circuits connected to the corresponding LEDs among a plurality of LEDs and driving the corresponding LEDs with luminances based on set values and power supply circuits for 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 LEDs in parallel.

Claims20

Dependent claims

A processor comprising:

a first interface configured to control an operation of a first display device;
and
a second interface configured to provide a first control signal to a first power supply device,
wherein the first power supply device comprises a first drive circuit configured to drive a first light emitting element corresponding to the first display device based on the first control signal, a first decision circuit configured to decide whether a first drive voltage of the first drive circuit is smaller than a first reference voltage, and a first power supply control circuit configured to boost a first supply voltage for the first light emitting element when the first decision circuit indicates that the first drive voltage is smaller than the first reference voltage.

1 more element

A processing system, the system comprising:

a processing unit including a first interface and a second interface, the first interface being configured to control an operation of a first display device, and the second interface being configured to provide a first control signal;
and
a first power supply device, configured to receive the first control signal from the processing unit, the first power supply device comprising a first drive circuit configured to drive a first light emitting element corresponding to the first display device based on the first control signal, a first decision circuit configured to decide whether a first drive voltage of the first drive circuit is smaller than a first reference voltage, and a first power supply control circuit configured to boost a first supply voltage for the first light emitting element when the first decision circuit indicates that the first drive voltage is smaller than the first reference voltage.

Dependencies are inferred from the claim text.

Facts

Application

14/086,570Filed 21 Nov 2013 · continuation

Priority

JP 2002-16053631 May 2002

Published

US 2014/0078030 A120 Mar 2014

Granted

27 Jan 2015

Term ends

Not estimatedThe source records don’t support an estimate.

Classification10 codes

H05B 45/40
Circuit arrangements for operating light-emitting diodes [LED]: details of LED load circuits
G09G 3/3208
Semiconductive, e.g. using light-emitting diodes [LED]: organic, e.g. using organic light-emitting diodes [OLED]
H05B 45/20
Circuit arrangements for operating light-emitting diodes [LED]: controlling the colour of the light
H05B 45/37
Driver circuits: converter circuits

Family

PCT/JP03/06735Parent of this continuation · filed 29 May 2003

Application12/076,996Parent of this continuation · filed 26 Mar 2008

US 7,365,718 B2Parent of this continuation · filed 29 Apr 2008

Application13/596,896Parent of this continuation · filed 28 Aug 2012

US 2014/0078030 A1Pre-grant publication · published 20 Mar 2014

US 8,618,745 B2Parent of this continuation

US 8,654,059 B2Parent of this continuation

Application10/512,982Parent of this continuation

US 2005/0225515 A1Published application

US 2008/0204381 A1Published application

US 2013/0033196 A1Published application

US 8,941,581 B2This patent

From the US filing history. Foreign family members aren’t listed.

Light emitting element drive apparatus and portable apparatus using same

Life of this patent

Light emitting element drive apparatus and portable apparatus using same

Life of this patent

Abstract

Claims20