Light emitting element drive apparatus and portable apparatus using same

• US 9,717,124 B2
• Filed: 08/19/2015
• Issued: 07/25/2017
• Est. Priority Date: 05/31/2002
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.), Sony Mobile Communications Incorporated (Sony Group Corp.)
• Inventors: Tsuchida, Kazuhito, Saito, Junji, Sudo, Kazuo
• Primary Examiner(s): TRAN, THUY V
• Application Number:
  US14/830,257
• Publication Number:
  US 20150359058A1
• Time in Patent Office: 706 Days
• Field of Search: 315246, 315250, 315291, 315294, 315297, 315299, 315300, 315307, 315308, 315312, 315320, 315324, 345102
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/37 Converter circuits
• CPC Class Codes: H05B 45/40 Details of LED load circuits
• CPC Class Codes: H05B 45/46 having LEDs disposed in parallel lines
• CPC Class Codes: H05B 47/16 by timing means
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

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.

Claims

1. An apparatus comprising:

first light emitting elements configured to emit a first color of light at a first luminance, an anode of at least one of the first light emitting elements is electrically connected to an anode of another of the first light emitting elements;

second light emitting elements configured to emit a second color of the light at a second luminance, an anode of at least one of the second light emitting elements is electrically connected to an anode of another of the second light emitting elements;

light emitting element drive circuitry configured to drive said at least one the first light emitting elements to emit the first color of the light at the first luminance, the light emitting element drive circuitry is configured to drive said at least one the second light emitting elements to emit the second color of the light at the second luminance; and

power supply circuitry configured to decide a lowest drive voltage required for enabling a light emitting element having a highest forward voltage among the first light emitting elements and the second light emitting elements to be driven at a set current value to emit the light.

2. An apparatus as set forth in claim 1, wherein the first color differs from the second color.

3. An apparatus as set forth in claim 1, wherein the first luminance differs from the second luminance.

4. An apparatus as set forth in claim 1, wherein the first light emitting elements has a forward voltage that differs from a forward voltage for the second light emitting elements.

5. An apparatus as set forth in claim 1, wherein the light emitting element drive circuitry is configured to adjust the first luminance without adjusting the second luminance.

6. An apparatus as set forth in claim 1, wherein the anode of said at least one of the first light emitting elements is electrically connected to the light emitting element drive circuitry.

7. An apparatus as set forth in claim 6, wherein the anode of said at least one of the second light emitting elements is electrically connected to the light emitting element drive circuitry.

8. An apparatus as set forth in claim 1, wherein a cathode of said at least one of the first light emitting elements is electrically connected to the light emitting element drive circuitry.

9. An apparatus as set forth in claim 8, wherein a cathode of said at least one of the second light emitting elements is electrically connected to the light emitting element drive circuitry.

10. An apparatus as set forth in claim 8, further comprising:

a current drive circuit in the light emitting element drive circuitry, the cathode of said at least one of the first light emitting elements is electrically connected to the current drive circuit.

11. An apparatus as set forth in claim 10, wherein a current source in the current drive circuit is electrically connected to the cathode of said at least one of the first light emitting elements.

12. An apparatus as set forth in claim 1, wherein the first light emitting elements are light emitting diodes.

13. An apparatus as set forth in claim 12, wherein the first light emitting elements are configured to emit white light.

14. An apparatus as set forth in claim 1, wherein the second light emitting elements are different color of the light emitting diodes from the first light emitting elements.

15. An apparatus as set forth in claim 14, wherein the second light emitting elements are configured to emit orange light or red light.

16. An apparatus as set forth in claim 1, further comprising:

wiring that directly electrically connects the anode of said at least one of the first light emitting elements to the anode of said at least one of the second light emitting elements.

17. A lighting system comprising:

an apparatus as set forth in claim 1;

a first portion that includes the first light emitting elements; and

a second portion that includes the second light emitting elements.

18. A lighting system as set forth in claim 17, wherein the light emitting element drive circuitry is configured to control a supply of a luminance set data and a flashing operation command data.

19. A lighting system as set forth in claim 17, wherein the light emitting element drive circuitry is configured to control an operation of the light emitting element drive apparatus based on an input data from an input device.

20. A lighting system as set forth in claim 17, wherein an illumination of the second portion has a color different from an illumination of the first portion.

21. A lighting system as set forth in claim 20, wherein the illumination of the second portion is driven by a flashing operation.