Arrangement for changing the visual appearance of a target object

• US 9,851,072 B2
• Filed: 04/08/2014
• Issued: 12/26/2017
• Est. Priority Date: 04/09/2013
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Philips Lighting BV (Koninklijke Philips N.V.)
• Inventors: Wagemans, Wiebe, Plasschaert, Helena Bernadette Jos, Lenssen, Kars-Michiel Hubert, Sekulovski, Dragan, Kurt, Ralph
• Primary Examiner(s): Garlen, Alexander
• Application Number:
  US14/782,824
• Publication Number:
  US 20160025304A1
• Time in Patent Office: 1,358 Days
• CPC Class Codes: F21S 10/023 by selectively switching fixed light sources
• CPC Class Codes: F21S 8/046 having multiple lighting devices, e.g. connected to a common ceiling base
• CPC Class Codes: F21V 14/02 by movement of light sources in vehicle head lamps F21S41/657
• CPC Class Codes: F21V 9/30 Elements containing photoluminescent material distinct from or spaced from the light source shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40
• CPC Class Codes: F21W 2131/405 for shop-windows or displays
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G09F 13/02 Signs, boards, or panels, illuminated by artificial light sources positioned in front of the insignia

Abstract

The invention relates to an arrangement (100) comprising a lighting system (110) and a target object (120), wherein the lighting system (110) is arranged to illuminate a target surface of the target object (120) with a primary light output (111) and with a secondary light output (112). Each of these light outputs has an illumination spectrum representing a color. The two illumination spectra are different, but the two colors are substantially the same. The target surface has a first target surface area and a second target surface area. When the first and second target surface areas are illuminated with the primary light output (111), they have a contrast that is lower than when they are illuminated with the secondary light output (112). The arrangement of the invention can be used for atmosphere creation or for attracting attention to the target object (120).

Claims

1. An arrangement comprising a lighting system and a target object, the lighting system being arranged to illuminate a target surface of the target object with a primary light output having a primary illumination spectrum representing a first color, and with a secondary light output having a secondary illumination spectrum representing a second color, wherein the primary and secondary illumination spectra have different spectral power distributions, and wherein the first and second colors have a color difference that is equal to or lower than a predetermined threshold (Δ

E_T) that is the lower of 20 and the outcome of the following equation;

Δ

E_T=Δ

E₀+α

Δ

t

wherein Δ

E₀ is equal to 8, α

is equal to 8 per second, and Δ

t represents the shortest time it takes the illumination of an arbitrary area on the target surface to change between the primary light output and the secondary light output, and

the target surface comprising a first target surface area and a second target surface area, wherein upon illumination with the primary illumination spectrum, the first target surface area has a primary first color and the second target surface area has a primary second color, and the first and second target surface areas have a first contrast, and upon illumination with the secondary illumination spectrum, the first target surface area has a secondary first color and the second target surface area has a secondary second color, and the first and second target surface areas have a second contrast, the second contrast being larger than the first contrast, and the term “

contrast”

referring to the color difference of the first and second target surface areas, and for two colors in CIE 1967 (L*a*b*) color space, the color difference is given by

Δ

E=√

{square root over ((L₂*−

L₁*)²+(a₂*−

a₁*)²+(b₂*−

b₁*)²)} 

 

(2)

where L₁* and L₂* respectively refer to lightness of the two colors, a₁* and b₁* relate to chromaticity of one color, a₂* and b₂* relate to chromaticity of the other color.

2. The arrangement according to claim 1, wherein the primary first and second colors, and the secondary first color are substantially the same but different from the secondary second color.

3. The arrangement according to claim 1, wherein the primary and secondary first colors are substantially the same but different from the primary and secondary second colors.

4. The arrangement according to claim 2, wherein the first target surface area has a first reflectance spectrum, and the second target surface area has a second reflectance spectrum, wherein the product of the primary illumination spectrum and the first reflectance spectrum, the product of the primary illumination spectrum and the second reflectance spectrum, and the product of the secondary illumination spectrum and the first reflectance spectrum have substantially the same spectral power distribution within the visible spectrum, and wherein the product of the secondary illumination spectrum and the second reflectance spectrum has a different spectral power distribution.

5. The arrangement according to claim 2, wherein the second target surface area comprises a photoluminescent material that can be excited with light that is present in one of the primary and secondary illumination spectra.

6. The arrangement according to claim 2, wherein the second target surface area comprises a photochromic material that has a primary reflectance spectrum when illuminated with the primary light output and a secondary reflectance spectrum when illuminated with the secondary light output, the secondary reflectance spectrum being different from the primary reflectance spectrum.

7. The arrangement according to claim 1, wherein the first and second target surface areas have metameric colors, and wherein the second contrast is different from the first contrast due to metameric failure.

8. The arrangement according to claim 1, wherein the lighting system is arranged to illuminate the second target surface area with a time-varying secondary light output.

9. The arrangement according to claim 1, wherein the arrangement is part of a retail environment, and wherein the target object is either a good or a sign in the retail environment.

10. A lighting device for use in the arrangement of claim 1, the lighting device being arranged to provide the primary light output and the secondary light output.

11. The lighting device according claim 10, wherein the lighting device is arranged to be operated in a first mode for providing the primary light output and in a second mode for providing the secondary light output, the lighting device further comprising a switching controller for switching between the first and second modes.

12. The lighting device according to claim 10, wherein, in operation, the primary and secondary light outputs are directed into different directions.

13. The lighting device of claim 12, further comprising a directionality controller for dynamically changing the directions of the primary and secondary light outputs.

14. The lighting device according to claim 10, wherein the primary illumination spectrum consists of light with wavelengths in the visible part of the electromagnetic spectrum, and wherein the secondary illumination spectrum comprises light with wavelengths in the ultraviolet and/or infrared part of the electromagnetic spectrum.

15. The lighting device according to claim 10, wherein the primary light output is provided by a first light source, and wherein the secondary light output is provided by a second light source or by a combination of the first light source and the second light source.