Pixilated LED light source for channel letter illumination

• US 9,297,525 B2
• Filed: 01/14/2010
• Issued: 03/29/2016
• Est. Priority Date: 10/03/2006
• Status: Active Grant

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Epistar Corporation (Ennostar, Inc.)
• Inventors: Cao, Densen
• Primary Examiner(s): Sawhney, Hargobind S
• Application Number:
  US12/687,838
• Publication Number:
  US 20100117560A1
• Time in Patent Office: 2,266 Days
• Field of Search: 362/26, 362/27, 362240-243, 362/245, 362/249.01, 362/249.02, 362/252, 362/290, 362/291, 362/304, 362/354, 362/361, 362/800, 362/802, 362/812, 362/249.06, 404/47, 404/50, 404/51, 404/52, 404/63, 405/41, 405/42, 405/50, 405/52, 405/53, 405/64, 405/67, 405/70, 405/73, 405/76, 405/79, 405/80, 405/91, 340/815.45, 340/815.53, 345/34, 345/82, 361/728
• US Class Current: 1/1
• CPC Class Codes: F21K 9/20 Light sources comprising attachment means
• CPC Class Codes: F21S 2/005 of modular construction
• CPC Class Codes: F21V 23/005 the substrate is supporting also the light source
• CPC Class Codes: F21V 31/04 Provision of filling media
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G09F 9/33 being semiconductor devices, e.g. diodes

Abstract

The present invention is an LED module for channel letter illumination utilizing multiple through-hole LEDs in a pixel formation as a light source where one surface mounted LED or other forms of LEDs were previously used. The use of a number of small through-hole LEDs ideally requires that a beam angle between and including 15° and 180° in vertical and horizontal directions, respectively, be utilized. When multiple light sources are used on a module, the distance between light sources is to be between 20 mm and 1 cm. The use of several smaller LEDs reduces the current needed to generate light of appropriate intensity and, thus reduces energy cost and heat generation. The use of smaller LEDs also assists in excess heat dissipation.

Claims

1. A light source module for providing light to a channel letter device, comprising:

a plastic casing, the plastic casing having a first surface and an attachment element configured for attaching the plastic casing to the channel letter device,

wherein the first surface of the plastic casing has a length and a plurality of through-holes extending through the first surface, and the plurality of through-holes is arranged among a sequence of pixel groups;

wherein each one of the sequence of pixel groups has a cluster of through-holes confined to a corresponding one of a sequence of regions set apart a distance from one another along the length of the first surface, the number “

M”

of through-holes in each cluster is greater than or equal to 3 and wherein the number “

N”

of clusters of through-holes in the sequence of pixel groups is greater than or equal to 2;

a printed circuit board housed within the plastic casing; and

a plurality of through-hole LEDs being electrically connected to the printed circuit board, the plurality of through-hole LEDs corresponding to, and extending through, the plurality of through-holes, a portion of each through-hole LED of the plurality of LEDs protruding from the plastic casing, each one of the plurality of through-hole LEDs having a diameter of about 5 mm or less.

2. The light source module of claim 1, further comprising a driving circuit connected to the printed circuit board to regulate the current and voltage to the plurality of LEDs.

3. The light source module of claim 2, wherein each one of the plurality of through-hole LEDs is elliptically shaped.

4. The light source module of claim 3, wherein each one of the plurality of through-hole LEDs has a diameter equal to about 5 mm.

5. The light source module of claim 4, wherein each one of the clusters of through-holes is arranged in a pattern duplicating a shape chosen from the set of shapes consisting of:

stars, asterisks, triangles, squares, rectangles, ellipses and arcs.

6. The light source module of claim 5, wherein each one of the first plurality of through-hole LEDs has a color selected from the set of colors consisting of:

red, green, blue, yellow, purple and white.

7. The light source module of claim 6, wherein the printed circuit board is coated with a waterproof epoxy coating and the light source module is sealed with waterproof epoxy coating.

8. The light source module of claim 1, wherein each one of the plurality of through-hole LEDs is elliptically shaped.

9. The light source module of claim 1, wherein each one of the plurality of through-hole LEDs has a diameter of about 5 mm.

10. The light source module of claim 1, wherein each one of the clusters of through-holes is arranged in a pattern duplicating a shape chosen from the set of shapes consisting of:

stars, asterisks, triangles, squares, rectangles, ellipses and arcs.

11. The light source module of claim 1, wherein each one of the plurality of through-hole LEDs has a color selected from the set of colors consisting of:

red, green, blue, yellow, purple and white.

12. The light source of claim 1, wherein the set-apart distance between each adjacent regions in the sequence of regions is between about 20 mm to about 1 cm.

13. The light source module of claim 1, wherein the printed circuit board is coated with a waterproof epoxy coating and the light source module is sealed with waterproof epoxy coating.

14. The light source module of claim 1, wherein the plurality of through-hole LEDs are not surface mounted LEDs.

15. The light source module of claim 1, wherein the light source module does not include a heat sink.

16. A light source module for providing light to a channel letter device, comprising:

a plastic casing, the plastic casing being enclosed and having a first surface;

an attachment socket for securing the light source module to a wall of the channel letter device,

wherein the first surface of the plastic casing has a length and a plurality of through-holes extending through the first surface;

a printed circuit board housed within the plastic casing;

a plurality of through-hole LEDs being electrically connected to said printed circuit board, the plurality of through-hole LEDs corresponding to, and extending through, the plurality of through-holes in the first surface, a portion of each through-hole LED of the plurality of LEDs protruding from the plastic casing, each one of the plurality of through-hole LEDs having a diameter of about 5 mm or less;

an epoxy coating applied to the printed circuit board and around the first plurality of through-hole LEDs to seal the light source module; and

a plurality of connection wires electrically connected to the printed circuit board and extending out of the plastic casing for supplying power to the light source module.

17. A light source module for providing light to a channel letter device, comprising:

a plastic casing, the plastic casing being enclosed and having a first surface;

an attachment socket connected to the plastic casing for securing the light source module to a wall of the channel letter device;

wherein the first surface of the plastic casing has a length and a plurality of through-holes extending through the first surface, the plurality of through-holes is arranged among a sequence of pixel groups;

wherein each one of the sequence of pixel groups has a cluster of through-holes confined to a corresponding one of a sequence of regions set apart a distance from one another along the length of the first surface, the number “

M”

of through-holes in each cluster is greater than or equal to 3 and the number “

N”

of clusters of through-holes in the sequence of pixel groups is greater than or equal to 2;

a printed circuit board housed within the plastic casing;

a plurality of through-hole LEDs being electrically connected to the printed circuit board, the plurality of through-hole LEDs corresponding to, and extending through, the plurality of through-holes in the first surface, a portion of each through-hole LED of the plurality of LEDs protruding from the plastic casing, each one of the plurality of through-hole LEDs having a diameter of about 5 mm or less;

an epoxy coating applied to the printed circuit board and around the plurality of through-hole LEDs to seal the light source module; and

connection wires electrically connected to the printed circuit board and extending out of the casing for supplying power to the light source module;

wherein the plurality of through-hole LEDs is equal in number to M*N.