Controlling Shape and Direction of Light

• US 20080211978A1
• Filed: 07/06/2006
• Published: 09/04/2008
• Est. Priority Date: 07/08/2005
• Status: Abandoned Application

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Ansems, Johannes Petrus Maria, Hikmet, Rifat Ata Mustafa
• Application Number:
  US11/994,589
• Publication Number:
  US 20080211978A1
• Time in Patent Office: Days
• US Class Current: 349/33
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/29 for the control of the position or the direction of light beams, i.e. deflection
• CPC Class Codes: G02F 2203/28 focussing or defocussing

Abstract

A device (201) for controlling shape and direction of light, comprises a first transparent planar substrate (203) and a second transparent planar substrate (205), the substrates being configured for arrangement essentially perpendicular to incident light beams (211), a liquid crystal layer (209) arranged between the first and second substrate, a first transparent electrode pattern (207) arranged on the first substrate and a second transparent electrode pattern (217) arranged on the second substrate, and control means configured to adjust an electric potential difference between the first and second electrode patterns, thereby configured to adjust a refractive index of the liquid crystal layer.

Claims

1. A device (100, 201, 501, 601, 651) for controlling shape and direction of light, comprising:

a first transparent planar substrate (203, 503) and a second transparent planar substrate (205, 505), the substrates being configured for arrangement essentially perpendicular to incident light beams (211),

a liquid crystal layer (209, 506) arranged between the first and second substrate,

a first transparent electrode pattern (207, 507, 700, 800) arranged on the first substrate and a second transparent electrode pattern (217, 509, 700, 800) arranged on the second substrate, and

control means (103, 513) configured to adjust an electric potential difference between the first and second electrode patterns, thereby configured to adjust a refractive index of the liquid crystal layer.

2. The device according to claim 1, where the control means are configured to adjust the potential difference in accordance with an AC frequency.

3. The device according to claim 1, where the first electrode pattern is essentially identical to the second electrode pattern.

4. The device according to claim 1, where any of the first electrode pattern and the second electrode pattern (207) comprises a plurality of hexagonal features.

5. The device according to claim 1, where any of the first electrode pattern (700, 800) and the second electrode pattern (700, 800) comprises a plurality of electrode segments (701, 703, 705, 707, 801, 803, 805, 807), each segment being configured to be individually adjusted with respect to electric potential.

6. The device according to claim 1, where any one of the first electrode pattern and the second electrode pattern is substantially featureless.

7. The device according to claim 1, where any of the first electrode pattern and the second electrode pattern is coated with a layer (220) having a high surface resistance.

8. The device according to claim 1, where the electrode patterns comprise features of spatial dimensions essentially in the interval 1-10 μ

m.

9. The device according to claim 1, where the electrode patterns covered by a non-conducting or high surface resistance layer comprise features of spatial dimensions essentially in the interval 10-100 μ

m.

10. The device according to claim 1, where the first substrate and the second substrate are separated by a distance in the interval 5-50 μ

m.

11. The device according to claim 1, where the electrodes are made of Indium Tin Oxide.

12. The device according to claim 1, where total transmission in the wavelength range 500 nm-800 nm is higher than 80%.

13. The device according to claim 1, where the controller is configured to adjust the electric potential difference between the first and second electrode patterns in the interval 0-20V.

14. A device (601, 651) for controlling shape and direction of light, comprising a first device (611) according to claim 1 in which the liquid crystal material is aligned along a first direction of orientation (612), a second device (613) according to claim 1 in which the liquid crystal material is aligned along a second direction of orientation (614).

15. The device according to claim 14, where said first direction of orientation is essentially perpendicular to said second direction of orientation.

16. The device according to claim 14, where said first direction of orientation is essentially parallel to said second direction of orientation, further comprising a half wave plate (617) arranged between said first and second devices.

17. The device according to claim 14, where the first and the second devices are arranged so as to avoid appearance of local maxima and minima in the intensity of transmitted light.

18. A lighting system (900) comprising a device according to claim 1 and at least one light source (107, 905).

19. The lighting system according to claim 18, where the at least one light source comprises at least one light emitting diode emitting light having at least one color.