Plate

• US 20020178627A1
• Filed: 05/31/2002
• Published: 12/05/2002
• Est. Priority Date: 06/01/2001
• Status: Active Grant

• Current Assignee: REBO Lighting & Electronics GmbH (PTC Inc.)
• Original Assignee: REBO Lighting & Electronics GmbH (PTC Inc.)
• Inventors: Gotthardt, Frank, Tietze, Martin, Quendt, Peer
• Granted Patent: US 6,698,118 B2
• Time in Patent Office: Days
• US Class Current: 40/205
• CPC Class Codes: B60R 13/10 Registration, licensing, or like devices
• CPC Class Codes: G09F 13/04 Signs, boards or panels, illuminated from behind the insignia
• CPC Class Codes: G09F 13/22 electroluminescent electroluminescent light sources per se H05B33/00
• CPC Class Codes: H10K 50/856 comprising reflective means
• CPC Class Codes: H10K 59/221 Static displays, e.g. displaying permanent logos
• CPC Class Codes: H10K 59/878 comprising reflective means

Abstract

A plate such as a motor vehicle licence plate comprises a casing which includes a flat rear wall surrounded by a forwardly projecting edge defining a light transmission opening, through which a flat symbol carrier extending parallel to the rear wall of the casing is visible. The symbol carrier has regions of differing transparency to represent symbols thereon. An electrically activatable light film between the rear wall and the symbol carrier shines light through the symbol carrier from the rear. To provide retroreflective properties, arranged in front of the light film and parallel thereto is a film which extends at least over considerable parts of the area of the light transmission opening and which is at least partially transparent for the light from the rear and which is retroreflective for light impinging thereon from the exterior. A light cover which is transparent at least in region-wise manner closes the light transmission opening. A rough layer is provided between the inward surface of the light cover and the surface that is theretowards of the retroreflective film.

Claims

1. A plate comprising

a casing including an at least substantially flat first wall forming a rear wall and an edge portion extending around said first wall and projecting forwardly therefrom and defining a light transmission opening for light to pass therethrough,

a flat symbol carrier which extends parallel to said first wall of the casing with at least one symbol thereon, the symbol carrier having regions of differing transparency to represent the at least one symbol thereon,

an electrically activatable light film between said first wall and said symbol carrier, said light film being operable for providing illumination at least through the regions of relatively higher transparency of the symbol carrier from the rear thereof,

a retroreflective film in front of the electrically activatable light film and in parallel relationship therewith, the retroreflective film extending at least over considerable portions of the area of the light transmission opening and being at least partially transparent for light coming from the rear of the retroreflective film from the light film and being retroreflective for light passing from the outside through the light transmission opening and impinging on said retroreflective film,

an at least region-wise transparent light cover closing the light transmission opening, and

a rough layer between the inward side of the light cover and the surface theretowards of said retroreflective film.

2. A plate as set forth in claim 1

wherein said rough layer includes a film which is rough on both sides and which is arranged between said retroreflective film and said light cover, said rough film extending in parallel relationship with the retroreflective film at least over a substantial part of the region of the retroreflective film which is visible through the light cover.

3. A plate as set forth in claim 1

wherein the rough layer includes a rough coating on the surface of the retroreflective film that is towards the light cover.

4. A plate as set forth in claim 1

wherein the rough layer includes a rough coating on the surface of the light cover that is towards the retroreflective film.

5. A plate as set forth in claim 1

wherein the light cover serves also as the symbol carrier.

6. A plate as set forth in claim 2

wherein the rough film also serves as the symbol carrier.

7. A plate as set forth in claim 1

wherein the retroreflective film also serves as the symbol carrier.

8. A plate as set forth in claim 1

wherein the symbol carrier is an independent symbol carrier.

9. A plate as set forth in claim 8

wherein the symbol carrier is in the form of an inherently stiff plate member.

10. A plate as set forth in claim 8

wherein the symbol carrier is a flexible film.

11. A plate as set forth in claim 2

wherein the light film, the retroreflective film and the rough film are held in a condition of bearing loosely against each other between said first wall of the casing and the light cover.

12. A plate as set forth in claim 1

wherein the electrically activatable light film is an electroluminescence film.

13. A plate as set forth in claim 1

wherein the electrically activatable light film is a light film with organic light emitting diodes.

14. A plate as set forth in claim 1 in the form of a motor vehicle licence plate

wherein the symbol carrier carries vehicle identification symbols.

15. A vehicle licence plate comprising

a casing including an at least substantially flat first wall having an edge and an edge wall portion extending around said first wall at said edge and projecting therefrom to define an opening for light to pass into and out of said casing,

a flat symbol carrier extending parallel to said first wall of the casing and having regions of differing transparency to represent at least one symbol thereon,

an electrically activatable light film between said first wall and said symbol carrier,

activating means connected to said light film operable for providing illumination at least through the regions of relatively higher transparency of the symbol carrier from the rear thereof,

a retroreflective film in front of the light film in parallel relationship therewith and extending at least over portions of the area of the opening of the casing and being at least partially transparent for light coming from the rear of the retroreflective film from the light film and being retroreflective for light passing from the outside through the opening of the casing and impinging on said retroreflective film,

an at least region-wise transparent light cover at the opening of the casing, and

a layer between the inward side of the light cover and the surface theretowards of said retroreflective film, the layer being non-smooth thereby to maintain the retroreflective film in a condition of not bearing over its entire surface area against the adjoining surface of the light cover.