LED and light diffuser for a lighted sign

• US 6,631,575 B1
• Filed: 08/10/2001
• Issued: 10/14/2003
• Est. Priority Date: 11/08/2000
• Status: Active Grant

• Current Assignee: Daktronics Incorporated
• Original Assignee: Daktronics Incorporated
• Inventors: Uehran, Randy Scott, Voelzke, Vernon P., Bravek, Eric S.
• Primary Examiner(s): Silbermann, Joanne
• Application Number:
  US09/927,149
• Time in Patent Office: 795 Days
• Field of Search: 404/51, 405/44, 405/70, 405/50
• US Class Current: 40/451
• CPC Class Codes: G09F 9/3023 Segmented electronic displays
• CPC Class Codes: G09F 9/33 being semiconductor devices, e.g. diodes

Abstract

An LED lighted sign with a light diffuser sheet with embedded diffusion particles which provides a 20%-40% increase in lighting transmittance. There is also provided a light divider assembly having partitions which serve to segregate groups of LEDs for lighting only selected segments of the light divider assembly for displaying numerical images. Alternatively, there is provided an injection molded light diffuser lens of the same material which secures to each of several light diffuser chambers which combine to display numerical images. optionally, colored LEDs may be used to create color displays. Color filters may also be overlaid the light diffusers or color pigment may be added to the diffusion material during injection molding to create color displays. A molded light divider assembly is also provided in the alternative.

Claims

1. A lighted alpha-numeric display assembly, comprising:

a. a printed circuit board;

b. a light divider assembly mounted on said printed circuit board, said light divider assembly comprising a plurality of partitions upstanding from said printed circuit board, said partitions forming seven geometric chambers of identical shape arranged in the form of a figure eight, each of said seven geometric chambers having an open top, and each of said seven geometric chambers further having a plurality of outwardly protruding tabs adjacent to its open top;

c. light emitting diodes associated with said printed circuit board and extending therefrom into said seven geometric chambers for providing illumination in each of said seven geometric chambers, there being a plurality of said light emitting diodes received in each of said seven geometric chambers;

d. separate light diffuser lenses corresponding in shape to the shape of said seven geometric chambers, said light diffuser lenses covering said open tops of said seven geometric chambers, each light diffuser lens having downwardly extending tab receivers corresponding in number to the plurality of outwardly protruding tabs of each of said seven geometric chambers, each tab receiver receiving one of said outwardly protruding tabs; and

,

e. a face plate arranged over said light diffuser lenses and secured to said light divider assembly, said face plate having seven geometric cutouts corresponding in shape to the shape of said seven geometric chambers and light diffuser lenses, and said seven geometric cutouts being in alignment with said seven geometric chambers and light diffuser lenses.

2. The lighted alpha-numeric display assembly as defined in claim 1, wherein said light emitting diodes are oval in shape with varying beam spread in two directions, which allows positioning of the light emitting diodes to distribute light in the most efficient manner to achieve uniform lighting within each of said seven geometric chambers.

3. The lighted alpha-numeric display assembly as defined in claim 1, wherein each of said seven geometric chambers has flexible locking tabs extending downwardly therefrom, and wherein said printed circuit board has apertures into which said flexible locking tabs are snappingly engaged.

4. The lighted alpha-numeric display assembly as defined in claim 1, wherein said face plate is planar and has upper and lower surfaces, and wherein said light diffuser lenses are received in said seven geometric cutouts of said face plate and extend up to or above said upper surface of said face plate.

5. The lighted alpha-numeric display assembly as defined in claim 1, wherein each light diffuser lens has high transmittance lighting output ratio, low diffusion-haze, light stability, and high service temperature withstand ability and is composed of an acrylic polymer having a first refractive index into which is incorporated spherical, high molecular weight polymer beads having a refractive index different from said first refractive index.

6. A lighted alpha-numeric display assembly, comprising:

a. a printed circuit board;

b. a light divider assembly mounted on said printed circuit board, said light divider assembly comprising a one-piece, unitary member having walls forming seven geometric chambers of identical shape arranged in the form of a figure eight, each of said seven geometric chambers having an upper surface, an open top, and a recess around the entire perimeter thereof adjacent to the open top;

c. light emitting diodes associated with said printed circuit board and extending therefrom into said seven geometric chambers for providing illumination in each of said seven geometric chambers, there being a plurality of said light emitting diodes received in each of said seven geometric chambers;

d. separate light diffuser lenses corresponding in shape to the shape of said seven geometric chambers, said light diffuser lenses being disposed in said recesses around the perimeters of said seven geometric chambers, covering said open tops of said seven geometric chambers, and lying flush with said upper surfaces of said seven geometric chambers; and

,

e. a face plate arranged over said light diffuser lenses and secured to said light divider assembly, said face plate having seven geometric cutouts corresponding in shape to the shape of said seven geometric chambers and light diffuser lenses, and said seven geometric cutouts being in alignment with said seven geometric chambers and light diffuser lenses.

7. The lighted alpha-numeric display assembly as defined in claim 6, wherein each light diffuser lens has high transmittance lighting output ratio, low diffusion-haze, light stability, and high service temperature withstand ability and is composed of an acrylic polymer having a first refractive index into which is incorporated spherical, high molecular weight polymer beads having a refractive index different from said first refractive index.

8. The lighted alpha-numeric display assembly as defined in claim 6, and further comprising a color filter in the form of a single, unitary sheet disposed between said light diffuser lenses and said face plate and extending across all of said light diffuser lenses.

9. The lighted alpha-numeric display assembly as defined in claim 6, wherein each of said light diffuser lenses has a number of ramped tabs extending outwardly along edges thereof, and wherein each of said recesses around the perimeters of said seven geometric chambers has a like number of ramped tab receivers communicating therewith into which said ramped tabs extend.

10. The lighted alpha-numeric display assembly as defined in claim 6, wherein said light divider assembly is gray or a shade of gray in color.