Lighting apparatus with optical member having asymmetric light incident surface

• US 9,849,984 B2
• Filed: 04/11/2014
• Issued: 12/26/2017
• Est. Priority Date: 04/12/2013
• Status: Expired due to Fees

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: Ohta, Takashi, Murakami, Tadashi
• Primary Examiner(s): Kryukova, Erin
• Application Number:
  US14/250,888
• Publication Number:
  US 20140307453A1
• Time in Patent Office: 1,355 Days
• Field of Search: 362223, 362470-742
• CPC Class Codes: B64D 11/00 Passenger or crew accommodation; Flight-deck installations not otherwise provided for
• CPC Class Codes: B64D 2011/0038 Illumination systems for cabins as a whole
• CPC Class Codes: B64D 2203/00 Aircraft or airfield lights using LEDs
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 5/08 producing an asymmetric light distribution
• CPC Class Codes: G02B 19/0061 the light source comprising a LED semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission H01L33/00
• CPC Class Codes: Y02T 50/40 Weight reduction

Abstract

A lighting apparatus includes a plurality of LEDs arranged in a row on an elongated wiring board; and a lens covering all the LEDs and controlling distribution of light emitted from each LED. An optical axis of the light emitted from each LED is orthogonal to the wiring board. The lens has a light emitting surface that controls distribution of the light emitted from each LED. When the light emitting surface is divided into at least three regions, the lens performs light distribution such that light radiated from a region is distributed in a direction tilted with respect to the optical axis of the light emitted from the LED. Thus, asymmetric distribution of light is achieved when the optical axis of the light from the LED is the axis of symmetry, and further, the luminous flux in the direction tilted with respect to the optical axis is increased most.

Claims

1. A lighting apparatus that illuminates a ceiling above an aisle in a cabin of an aircraft, the aisle extending along a traveling direction of the aircraft, the lighting apparatus comprising:

a plurality of LEDs arranged in a row;

a wiring board having an elongated shape, on which the plurality of LEDs are mounted; and

an optical member that covers all of the plurality of LEDs and controls distribution of light emitted from each LED of the plurality of LEDs, wherein

the light emitted from the each LED has an optical axis orthogonal to the wiring board,

the optical member is an optical lens having a light incident surface on which the light emitted from the each LED is incident, and the light incident surface extends convexly toward the each LED and is partially asymmetric with respect to the optical axis of the light emitted from the each LED,

the optical member has a light emitting surface that emits the light whose distribution of the light emitted from the each LED is controlled, and when the light emitting surface is divided into at least three regions, the optical member performs light distribution such that light radiated from a region, among the at least three regions, through which the optical axis of the light emitted from the each LED passes, is distributed in a direction tilted with respect to the optical axis of the light emitted from the each LED, the optical member performs light distribution such that light radiated from, among the at least three regions, a second region around the region through which the optical axis of the light emitted from the each LED passes is distributed in a direction parallel to the optical axis of the light emitted from the each LED as viewed at a cross section orthogonal to a longitudinal direction of the wiring board, and

the cross sectional shape of the optical member is the same in any portion as viewed in the cross section orthogonal to the longitudinal direction.

2. The lighting apparatus according to claim 1, wherein

the light incident surface of the optical lens is a curved surface convex toward the wiring board, and a most projected portion of the curved surface deviates from the optical axis of the light emitted from the each LED.

3. The lighting apparatus according to claim 1, wherein

the light incident surface of the optical lens has a sawtooth-like prism surface at one of two parts into which the light incident surface is divided with respect to the optical axis of the light emitted from the each LED, as viewed at the cross section orthogonal to the longitudinal direction of the wiring board.