Light emitting element drive apparatus and portable apparatus using same

Patent metadata

Field	Value
Publication number	US-9148927-B2
Application number	US-201414448402-A
Country	US
Kind code	B2
Filing date	Jul 31, 2014
Priority date	May 31, 2002
Publication date	Sep 29, 2015
Grant date	Sep 29, 2015

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.

First claim

What is claimed:

1. An apparatus comprising:
light emitting elements of different drive voltages required for an emission of light;
a light emitting element drive apparatus to which said light emitting elements are connected in serial or in parallel, the light emitting element drive apparatus driving at least one of the light emitting elements to emit the light,
wherein said light emitting element drive apparatus includes:
a drive circuit connected to a corresponding light emitting element of the light emitting elements, said drive circuit driving the corresponding light emitting element with luminance based on a set current value;
a power supply circuit that fixes an output drive voltage to a predetermined set voltage irrespective of drive states of the light emitting elements when the light emitting element drive apparatus receives a predetermined flashing operation instruction command,

wherein said power supply circuit supplies the output drive voltage based on pulse width modulation.

2. An apparatus comprising:
one or more light emitting elements;
a light emitting element drive apparatus to which said one or more light emitting elements are connected, the light emitting element drive apparatus driving the one or more light emitting elements to emit the light,
wherein said light emitting element drive apparatus includes:
a drive circuit connected to a corresponding light emitting element of the one or more light emitting elements, said drive circuit driving the corresponding light emitting element with luminance based on a set current value;
a power supply circuit that fixes an output drive voltage to a predetermined set voltage irrespective of drive states of the one or more light emitting elements when the light emitting element drive apparatus receives a predetermined flashing operation instruction command,

wherein said power supply circuit supplies the output drive voltage based on pulse width modulation.

3. An apparatus comprising:
light emitting elements of different drive voltages required for an emission of light;
at least one illuminated portion illuminated by said light emitting elements; and
a light emitting element drive apparatus to which said light emitting elements are connected in serial or in parallel, the light emitting element drive apparatus driving at least one of the light emitting elements to emit the light,
wherein said light emitting element drive apparatus includes:
a drive circuit connected to a corresponding light emitting element of the light emitting elements, said drive circuit driving the corresponding light emitting element with luminance based on a set current value,
a power supply circuit that fixes an output drive voltage to a predetermined set voltage irrespective of drive states of the light emitting elements when the light emitting element drive apparatus receives a predetermined flashing operation instruction command,

wherein said power supply circuit supplies the output drive voltage based on pulse width modulation.

4. An apparatus comprising:
light emitting elements of different drive voltages required for an emission of light;
a light emitting element drive means for driving at least one of the light emitting elements to emit the light, said light emitting element drive means being connected to said light emitting elements in serial or in parallel,
wherein said light emitting element drive means includes:
a drive circuit means for driving a corresponding light emitting element of said light emitting elements with luminance based on a set current value, said drive circuit means being connected to the corresponding light emitting element;
a power supply means for fixing an output drive voltage to a predetermined set voltage irrespective of drive states of the light emitting elements when the light emitting element drive apparatus receives a predetermined flashing operation instruction command,

wherein said power supply means supplies the output drive voltage based on pulse width modulation.

Assignees

• Sony Corp
• Sony Mobile Comm Inc

Inventors

• Tsuchida Kazuhito
• Saito Junji
• Sudo Kazuo

Classifications

• H05B45/20

  Controlling the colour of the light · CPC title

• H05B47/16

  by timing means · CPC title

• H05B45/37

  Converter circuits · CPC title

• H05B45/46

  having LEDs disposed in parallel lines · CPC title

• G09G3/3208

  organic, e.g. using organic light-emitting diodes [OLED] · CPC title