# US 2013/0154466 A1 · Lamp with Graded Absorption Coating > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0154466 A1 - Document ID: US20130154466A1 - Status: Published application - Kind: A1 - Application number: 13/818,708 - Filed: 2011-08-24 - Published: 2013-06-20 - Earliest claimed: 2010-08-30 - Assignees: Koninklijke Philips Electronics N.V. - Inventors: Juergen Flechsig; Martin Tobias Polster; Hans-Alo Dohmen; Ralph Kecke - Web page: https://patentgrep.com/patent/US20130154466A1 ## CPC - H01J 61/40: by light filters; by coloured coatings in or on the envelope - H01J 61/025: {Associated optical elements} - H01J 61/35: provided with coatings on the walls thereof; Selection of materials for the coatings (using coloured coatings H01J61/40; using luminescent coatings H01J61/42) - H01K 1/32: provided with coatings on the walls; Vessels or coatings thereon characterised by the material thereof - H01J 9/20: Manufacture of screens on or from which an image or pattern is formed, picked up, converted or stored; Applying coatings to the vessel - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - H01K: ELECTRIC INCANDESCENT LAMPS (details, apparatus or processes for manufacture applicable to both discharge devices and incandescent lamps H01J; light sources using a combination of incandescent and other types of light generation H01J61/96, H05B35/00) ## Abstract The invention describes a lamp (1A, 1B, 1C, 1D) comprising a glass envelope (10) enclosing a light generating means (11), and an axially and/or circumferentially graded absorption coating (2A, 2B, 2C, 2D) applied to a surface of the glass envelope (10), wherein the graded absorption coating (2A, 2B, 2C, 2D) exhibits a smooth transition in a transition region (23A, 23C, 23D) from a first coated region (21 A, 21B, 21C, 21D) on the glass envelope (10) to a second coated region (22A, 22B, 22C, 22D) on the glass envelope (10). The invention further describes a lighting assembly (4) comprising a lamp according to any of claims 1 to 11 and a reflector (40) for collecting and shaping any light passing through the graded absorption coating (2A, 2B, 2C, 2D) of the lamp (1A, 1B, 1C, 1D). The invention also describes a method of manufacturing a lamp (1A, 1B, 1C, 1D) comprising a glass envelope (10) enclosing a light generating means (11), which method comprises applying an axially and/or circumferentially graded absorption coating (2A, 2B, 2C, 2D) to a surface of the glass envelope (10) such that the graded absorption coating (2A, 2B, 2C, 2D) exhibits a smooth transition in a transition region (23A, 23B, 23C, 23D) from a first coated region (21A, 21B, 21C, 21D) to a second coated region (22A, 22B, 22C, 22D). ## Claims ### Claim 1 An automotive front lamp comprising a glass envelope enclosing a light generating means, and an axially and/or circumferentially graded absorption coating applied to a surface of the glass envelope, wherein the graded absorption coating exhibits a smooth transition in a transition region from a first coated region on the glass envelope to a second coated region on the glass envelope. ### Claim 2 (depends on 1) A lamp according to claim 1, wherein the first coated region and the second coated region differ in layer thickness and/or particle density and/or layer count and/or colour. ### Claim 3 (depends on 1) A lamp according to claim 1, wherein the graded absorption coating has a thickness in the range 200 nm to 500 nm in the first coated region and in the range 500 nm to 1000 nm in the second coated region. ### Claim 4 (depends on 1) A lamp according claim 1, wherein the first coated region comprises an absorption coating with low particle density and the second coated region comprises an absorption coating with high particle density. ### Claim 5 (depends on 1) A lamp according to claim 1, wherein the number of layers in the first coated region is less than the number of layers in the second coated region. ### Claim 6 (depends on 1) A lamp according to claim 1, wherein a refractive index of the first coated region and a refractive index of the second coated region differ by at most 0.2. ### Claim 7 (depends on 1) A lamp according to claim 1, wherein the graded absorption coating comprises a single layer of an absorption material. ### Claim 8 (depends on 1) A lamp according to claim 1, wherein the first coated region is applied in the vicinity of the light generating means of the lamp, and a second coated region is applied to an outer region of the glass envelope. ### Claim 9 (depends on 1) A lamp according to claim 1, wherein the material of the graded absorption coating is chosen to raise the colour temperature of the lamp by at least 100K compared to an uncoated state of the lamp. ### Claim 10 (depends on 1) A lamp according to claim 1, wherein the graded absorption coating essentially entirely covers the surface of the glass envelope. ### Claim 11 (depends on 1) A lighting assembly comprising a lamp according to claim 1 and a reflector for collecting and shaping any light passing through the graded absorption coating of the lamp. ### Claim 12 (depends on 11) A lighting assembly according to claim 11, wherein the lamp comprises a H7 lamp with a light generating means comprises a filament, and the graded absorption coating is applied over the entire surface of the glass envelope of the lamp such that the first coated region is applied in the region of the filament and the second coated region is applied to an outer region of the glass envelope below the filament. ### Claim 13 A method of manufacturing an automotive front lamp comprising a glass envelope enclosing a light generating means, coating to a surface of the glass envelope such that the graded absorption coating exhibits a smooth transition in a transition region from a first coated region to a second coated region to alter a front beam generated by the lamp. ### Claim 14 (depends on 13) A method according to claim 13, wherein the step of applying the axially and/or circumferentially graded absorption coating comprises the steps of immersing the glass envelope in a coating bath; partially withdrawing the glass envelope from the coating bath at a first rate of withdrawal; and completely removing the glass envelope from the coating bath at a second rate of withdrawal whereby the first rate of withdrawal is gradually adjusted until the second rate of withdrawal is reached. ### Claim 15 (depends on 13) A method according to claim 13, wherein the step of applying the axially and/or circumferentially graded absorption coating comprises the steps of applying the coating essentially to the entire surface of the envelope; and removing a portion of the coating an area corresponding to the first coated region such that a thin layer of the absorption coating remains in that area.