LED LAMP

• US 20120306377A1
• Filed: 04/17/2012
• Published: 12/06/2012
• Est. Priority Date: 04/22/2011
• Status: Active Grant

• Current Assignee: IRIS Ohyama Incorporated (Oyama KK)
• Original Assignee: ROHM Co., Ltd.
• Inventors: IGAKI, Masaru, TANAKA, Masahide
• Granted Patent: US 9,080,758 B2
• Time in Patent Office: Days
• US Class Current: 315/151
• CPC Class Codes: F21K 9/278 Arrangement or mounting of circuit elements integrated in the light source
• CPC Class Codes: F21S 8/026 intended to be recessed in a ceiling or like overhead structure, e.g. suspended ceiling
• CPC Class Codes: F21S 8/04 intended only for mounting on a ceiling or the like overhead structures F21S8/02 takes precedence; details of ceiling bases F21V21/03
• CPC Class Codes: F21V 23/0464 the sensor sensing the level of ambient illumination, e.g. dawn or dusk sensors
• CPC Class Codes: F21V 23/0471 the sensor detecting the proximity, the presence or the movement of an object or a person
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2103/30 curved
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/12 using optical feedback
• CPC Class Codes: H05B 45/325 Pulse-width modulation [PWM]
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: H05B 47/115 by determining the presence or movement of objects or living beings
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

An LED lamp (1) is employed in a state mounted on a lighting fixture. The LED lamp (1) includes an LED source portion (2) including a plurality of LED chips, an illuminance sensor module (12) detecting ambient illuminance, and a controller controlling the LED source portion (2) in response to illuminance of ambient light other than light emitted by the LED source portion (2) on the basis of an output signal received from the illuminance sensor module (12) when the LED source portion (2) is in a lighting-up state. When the LED source portion (2) is in the lighting-up state, there is a possibility that the illuminance sensor module (12) detects not only the ambient light illuminance but also spontaneous light illuminance. The controller eliminates influence by the spontaneous light illuminance, and controls the LED source portion (2) in response to the illuminance of the ambient light.

Claims

1. An LED lamp mounted on a lighting fixture, comprising:

an LED source portion including a plurality of LED chips;

an illuminance sensor detecting ambient illuminance; and

a controller controlling the LED source portion in response to the illuminance of ambient light other than light emitted by the LED source portion on the basis of an output signal received from the illuminance sensor when the LED source portion is in a lighting-up state.

2. The LED lamp according to claim 1, wherein

the illuminance sensor is arranged to detect the light emitted by the LED source portion and the ambient light.

3. The LED lamp according to claim 1, wherein

the controller includes:

a spontaneous light illuminance calculating means calculating spontaneous light illuminance contributed to the output signal of the illuminance sensor by the light emitted by the LED source portion on the basis of a driven state of the LED source portion; and

an on-off control means turning on the LED source portion when ambient light illuminance obtained by subtracting the spontaneous light illuminance from the output signal of the illuminance sensor is less than or equal to a prescribed threshold and turning off the LED source portion when the ambient light illuminance is in excess of the threshold.

4. The LED lamp according to claim 3, wherein

the controller further includes an illuminance-adaptive driving means driving the LED source portion with power responsive to the ambient light illuminance when the ambient light illuminance is less than or equal to the threshold.

5. The LED lamp according to claim 1, wherein

the controller includes:

a storage means storing the output signal received from the illuminance sensor;

a comparison means comparing the output signal of the illuminance sensor and the value stored in the storage means with each other; and

an on-off control means turning on/off the LED source portion in response to the result of the comparison of the comparison means.

6. The LED lamp according to claim 5, wherein

the storage means is formed to store the output signal received from the illuminance sensor when the LED source portion is in a predetermined lighting-up state.

7. The LED lamp according to claim 5, further including a writing instruction means operated by an operator for writing the output signal of the illuminance sensor in the storage means, wherein

the controller further includes a writing means writing the output signal of the illuminance sensor in the storage means in response to an operation of the writing instruction means.

8. The LED lamp according to claim 7, wherein

the writing instruction means includes a lighting-up instruction means for turning on the LED source portion in a predetermined state, and

the controller further includes a writing control means inhibiting the writing means from writing the output signal when the output signal of the illuminance sensor has already been written in the storage means and allowing the writing means to write the output signal when the output signal of the illuminance sensor is not yet written in the storage means.

9. The LED lamp according to claim 8, further including an inhibition canceling operation means operated by the operator for canceling inhibition of the writing operation by the writing means, wherein

the writing control means is formed to allow the writing means to write the output signal in the storage means once in response to the operation of the inhibition canceling operation means.

10. The LED lamp according to claim 5, wherein

the comparison means includes a means determining whether or not the ambient light illuminance obtained by subtracting the value stored in the storage means from the output signal of the illuminance sensor is less than or equal to the prescribed threshold, and

the on-off control means is formed to turn on the LED source portion when the ambient light illuminance is less than or equal to the threshold and to turn off the LED source portion when the ambient light illuminance is in excess of the threshold.

11. The LED lamp according to claim 1, wherein

the controller includes a PWM control means PWM-controlling the LED source portion, and a sampling means sampling the output signal of the illuminance sensor as ambient light illuminance in an OFF-period when power supply to the LED source portion is stopped in a PWM cycle when the PWM control means PWM-controls the LED source portion, and is formed to control the LED source portion in response to the ambient light illuminance sampled by the sampling means.

12. The LED lamp according to claim 11, wherein

the controller further includes a duty ratio setting means setting a duty ratio in the PWM control on the basis of the ambient light illuminance sampled by the sampling means.

13. The LED lamp according to claim 1, further including a motion sensor having a predetermined sensitivity region, wherein

the controller is formed to control the LED source portion in response to an output signal received from the motion sensor.

14. The LED lamp according to claim 13, wherein

the controller is formed to increase driving power for the LED source portion in response to detection of a human being by the motion sensor.

15. The LED lamp according to claim 1, further including a noncontact temperature sensor detecting the temperature of an object present in a predetermined temperature-sensing area in a noncontact manner, wherein

the controller is formed to control the LED source portion in response to the temperature detected by the noncontact temperature sensor.

16. The LED lamp according to claim 13, wherein

the motion sensor includes a pyroelectric infrared sensor, and

the LED lamp further includes a shutter unit opening/closing an infrared incidence path to a photoreceiving surface of the pyroelectric infrared sensor.

17. The LED lamp according to claim 1, further including:

a pyroelectric infrared sensor having a predetermined sensitivity region; and

a shutter unit opening/closing an infrared incidence path to a photoreceiving surface of the pyroelectric infrared sensor, wherein

the controller is formed to determine the presence or absence of a human being in the sensitivity region on the basis of an output signal received from the pyroelectric infrared sensor and to control the LED source portion in response to the result of the determination.