Lighting with EMI shielding

• US 5,882,108 A
• Filed: 10/12/1995
• Issued: 03/16/1999
• Est. Priority Date: 10/12/1995
• Status: Expired due to Term

• Current Assignee: Valeo-Sylvania LLC
• Original Assignee: Valeo-Sylvania LLC
• Inventors: Fraizer, Robert L.
• Primary Examiner(s): LEE, Y MY QUACH
• Application Number:
  US08/542,109
• Time in Patent Office: 1,251 Days
• Field of Search: 362/61, 362/265, 362/293, 362/509, 362/510, 362/83.3, 264/1.7, 427/162, 359/585, 359/361
• US Class Current: 362/293
• CPC Class Codes: F21S 41/17 Discharge light sources
• CPC Class Codes: F21S 41/173 Fluorescent light sources
• CPC Class Codes: F21S 41/28 Cover glass
• CPC Class Codes: F21S 43/26 Refractors, transparent cover plates, light guides or filters not provided in groups F21S43/235 - F21S43/255
• CPC Class Codes: F21V 25/00 Safety devices structurally associated with lighting devices gas- tight or water-tight arrangements F21V31/00; in general F16P; protective circuit arrangements per se H02H7/00

Abstract

An EMI shielding lens for a lamp, e.g., an automotive lamp. The lens includes a transparent, unitary, polymeric lens blank and a thin, heat transferred grid layer including an electrically conductive grid pattern disposed on the lens blank inner or outer surface. The grid pattern may be formed from indium tin oxide or from a conductive, heat transferable, inks or polymer. The grid layer may also include colored or opaque indicia. Linear elements of the grid pattern are spaced apart by less than 1/2 λ of the EMI to be shielded. Also discloseed is an electromagnetic interference shielded lamp assembly including an electrically conductive housing, a light source within the housing, the EMI shielding lens fixed to the housing, and grounding means. Methods for fabricating the lens and the lamp assembly are also disclosed.

Claims

1. An electromagnetic interference shielded lamp assembly comprising:

an electrically conductive housing;

a light source within said housing;

an electromagnetic interference shielding lens fixed to said housing, said housing and said lens together enclosing said light source, said lens comprising;

(a) a transparent, unitary, polymeric lens blank having an inner surface and an outer surface, and

(b) a thin, translucent, electrically conductive grid layer held on a light transmissive support layer and conforming and bonded to a selected one of said lens blank inner and outer surface; and

an electrical coupling for electrically coupling said housing and said grid layer to a ground for shielding electromagnetic interference radiation emitted by said light source.

2. A lamp assembly in accordance with claim 1 wherein said grid layer is formed from indium tin oxide.

3. A lamp assembly in accordance with claim 1 wherein said grid layer includes a conductive grid pattern.

4. A lamp assembly in accordance with claim 3, wherein said grid layer includes linear elements spaced apart by less than 1/2 the wavelength of the electromagnetic radiation to be shield by the lens.

5. A lamp assembly in accordance with claim 1 wherein said lamp assembly is an automotive lamp assembly.

6. An electromagnetic interference shielded lamp assembly comprising:

an electrically conductive housing;

a light source within said housing;

an electromagnetic interference shielding lens fixed to said housing, said housing and said lens together enclosing said light source, said lens comprising;

(a) a transparent, unitary, polymeric lens blank having an inner surface and an outer surface, and

(b) a thin, translucent, electrically conductive grid layer conforming and bonded to a selected one of said lens blank inner and outer surface; and

an electrical coupling for electrically coupling said housing and said grid layer to a ground for shielding electromagnetic interference radiation emitted by said light source, said grid layer is formed from a material selected from a group consisting of conductive, heat transferable, inks and polymers.

7. A method of fabricating an electromagnetic interference shielding lens for a lamp, said method comprising the steps of:

providing a transparent, unitary, polymeric lens blank having an inner surface and an outer surface,

pressing a thin, adherent, translucent, electrically conductive grid layer on a light transmissive support layer the grid and support layer being held on a carrier surface, against a selected one of said lens blank inner and outer surfaces, while

applying heat to bond said grid and support layer to said selected on of said lens blank surfaces.

8. A method in accordance with claim 7 wherein said grid layer includes an electrically conductive grid pattern.

9. A method in accordance with claim 7 wherein said lamp is an automotive lamp.

10. A method of fabricating an electromagnetic interference shielded lamp assembly, said method comprising the steps of:

providing a transparent, unitary, polymeric lens blank having an inner surface and an outer surface;

pressing while in a heated state a thin, adherent, translucent, electrically conductive grid layer held on a light transmissive support layer, the grid layer and support layer held on a carrier surface, to a selected one of said lens blank inner and outer surfaces to thereby conform and bond said grid layer to said lens blank surface to form an electromagnetic interference shielding lens;

mounting a light source within an electrically conductive housing such that light from said light source is projected in a preselected direction; and

fixing said electromagnetic radiation shielding lens to said housing such that said housing and said lens together enclose said light source, the light from said light source being protected through said lens and said grid layer;

electrically coupling said housing and said grid layer to a ground for shielding electromagnetic interference radiation emitted by said light source.

11. A method in accordance with claim 10 wherein said grid layer includes an electrically conductive grid pattern.

12. A method in accordance with claim 10 wherein said lamp assembly is an automotive lamp assembly.