Sony Corporation

Sony Mobile Communications Inc.

Sony Ericsson Mobile Communications Japan, Inc.

Kazuo Sudo

Kazuhito Tsuchida

Junji Saito

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 apparatushas 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.

Light emitting element drive apparatus and portable apparatus using same

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 an LED drive apparatusto which LEDs-to-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-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.

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 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.

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.

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Kanagawa, Japan

Kazuo Sudo