Light emitting diode retrofitting lamps for illuminated signs

• US 5,949,347 A
• Filed: 08/20/1997
• Issued: 09/07/1999
• Est. Priority Date: 09/11/1996
• Status: Expired due to Term

• Current Assignee: Leotek Electronics USA Corporation (Lite-On Technology Corporation)
• Original Assignee: Leotek Electronics USA Corporation (Lite-On Technology Corporation)
• Inventors: Wu, Chen H.
• Primary Examiner(s): Wu, Daniel J.
• Assistant Examiner(s): Huang, Sihong
• Application Number:
  US08/914,967
• Time in Patent Office: 748 Days
• Field of Search: 340/815.45, 340/332, 340/907, 340/815.73, 345/82, 362/800, 362/812, 313/500, 313/318.01, 313/318.04, 40/564, 40/570, 40/572
• US Class Current: 340/815.45
• CPC Class Codes: F21K 9/23 Retrofit light sources for lighting devices with a single fitting for each light source, e.g. for substitution of incandescent lamps with bayonet or threaded fittings
• CPC Class Codes: F21Y 2107/50 on planar substrates or supports, but arranged in different planes or with differing orientation, e.g. on plate-shaped supports with steps on which light-generating elements are mounted
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G08B 7/062 indicating emergency exits
• CPC Class Codes: G09F 13/22 electroluminescent electroluminescent light sources per se H05B33/00
• CPC Class Codes: G09F 9/33 being semiconductor devices, e.g. diodes
• CPC Class Codes: Y10S 362/80 Light emitting diode
• CPC Class Codes: Y10S 362/812 Signs

Abstract

Retrofitting lamps using Light-Emitting Diodes (LEDs) as the illumination source. The lamps are fitted with any one of the common incandescent lamp bases for use as retrofit lamps for illuminated EXIT signs and the like. The LED lamps are electrically powered with a current limiting device to allow LED to operate at a desired current level. The LEDs are arranged on a shaped frame so that they are aimed in directions to provide bright and uniform illumination over an area of the face of the sign that is wider and longer than the width and the length of the lamps.

Claims

1. An LED lamp, comprising:

a lamp base;

an elongated lamp frame having a longitudinal axis and a front face; and

first and second linear arrays of light emitting diodes mounted on the front face and extending substantially parallel to the longitudinal axis, the first and second linear arrays are mounted to partially face toward each other.

2. The LED lamp of claim 1, wherein the front face has a U-shaped cross-section.

3. The LED lamp of claim 2, wherein the elongated lamp frame further comprises:

a rear face having a U-shaped cross-section; and

third and fourth linear arrays of light emitting diodes mounted on the rear face and extending substantially parallel to the longitudinal axis, the third and fourth linear arrays are mounted to partially face toward each other.

4. The LED lamp of claim 1, wherein the lamp base includes a threaded portion for connection into a threaded electrical socket, and a spring loaded center electrode.

5. The LED lamp of claim 1, wherein the lamp base and the lamp frame are rotatably connected to each other.

6. The LED lamp of claim 5, further comprising:

a set screw that fixes an angular orientation of the lamp base relative to the lamp frame, wherein the rotatable connection between the lamp base and the lamp frame includes a first set of threads formed on the lamp base that engage a second set of threads formed on the lamp frame.

7. An LED lamp, comprising:

a lamp base;

an elongated lamp frame having a longitudinal axis, a front face having a V-shaped cross-section, and a rear face having a V-shaped cross-section;

first and second linear arrays of light emitting diodes mounted on the front face and extending substantially parallel to the longitudinal axis, the first and second linear arrays are mounted to partially face away from each other; and

third and fourth linear arrays of light emitting diodes mounted on the rear face and extending substantially parallel to the longitudinal axis, the third and fourth linear arrays are mounted to partially face away from each other.

8. An LED lamp, comprising:

a lamp base;

an elongated lamp frame having a longitudinal axis and a front face;

first and second linear arrays of light emitting diodes mounted on the front face and extending substantially parallel to the longitudinal axis, the first and second linear arrays are mounted to partially face toward each other; and

third and fourth linear arrays of light emitting diodes mounted on the front face and extending substantially parallel to the longitudinal axis, wherein the front face has a W-shaped cross-section such that the first and second linear arrays partially face toward each other and the third and fourth linear arrays partially face away from each other.

9. The LED lamp of claim 8, wherein the elongated lamp frame further comprises:

a rear face having a W-shaped cross-section; and

a plurality of linear arrays of light emitting diodes each mounted on the rear face and extending substantially parallel to the longitudinal axis, wherein at least two of the plurality of linear arrays are mounted to partially face toward each other, and at least two other of the plurality of linear arrays are mounted to partially face away from each other.

10. An LED lamp, comprising:

a lamp base;

an elongated lamp frame having a longitudinal axis and a front face;

first and second linear arrays of light emitting diodes mounted on the front face and extending substantially parallel to the longitudinal axis, the first and second linear arrays are mounted to partially face toward or partially face away from each other;

at least one of the light emitting diodes from each of the first and second linear arrays are oriented to point in a direction toward the lamp base; and

at least another one of the light emitting diodes from each of the first and second linear arrays are oriented to point in a direction away from the lamp base.

11. An illuminated sign, comprising:

a housing with a front display panel that has a first translucent indicia portion;

an LED lamp disposed adjacent the front display panel, the LED lamp including;

a lamp base,

an elongated lamp frame having a longitudinal axis and a front face, and

first and second linear arrays of light emitting diodes mounted on the front face and extending substantially parallel to the longitudinal axis, the first and second linear arrays produce a first light output and are mounted to partially face toward each other;

wherein the first and second linear arrays project a majority of the first light output onto the front display panel at non-perpendicular angles relative to the front display panel.

12. The illuminated sign of claim 11, wherein the front face has a U-shaped cross-section.

13. The illuminated sign of claim 12, wherein:

the housing further includes a rear display panel having a second translucent indicia and opposing the front display panel, the LED lamp is disposed between the front and rear display panels; and

the elongated lamp frame further comprises;

a rear face having a U-shaped cross-section; and

third and fourth linear arrays of light emitting diodes mounted on the rear face and extending substantially parallel to the longitudinal axis, the third and fourth linear arrays produce a second light output and are mounted to partially face toward each other so that the third and fourth linear arrays project a majority of the second light output onto the rear display panel at non-perpendicular angles relative to the rear display panel.

14. The illuminated sign of claim 11, wherein the LED lamp is oriented to evenly illuminate a portion of the front display panel that is wider than a width of the front face.

15. The illuminated sign of claim 11, wherein the lamp base includes a threaded portion for connection into a threaded electrical socket, and a spring loaded center electrode.

16. The illuminated sign of claim 11, wherein the lamp base and the lamp frame are rotatably connected to each other.

17. The illuminated sign of claim 16, further comprising:

a set screw that fixes an angular orientation of the lamp base relative to the lamp frame, wherein the rotatable connection between the lamp base and the lamp frame includes a first set of threads formed on the lamp base that engage a second set of threads formed on the lamp frame.

18. An illuminated sign comprising:

a housing with a front display panel that has a first translucent indicia portion;

an LED lamp disposed adjacent the front display panel, the LED lamp including;

a lamp base,

an elongated lamp frame having a longitudinal axis and a front face having a V-shaped cross-section, and

first and second linear arrays of light emitting diodes mounted on the front face and extending substantially parallel to the longitudinal axis, the first and second linear arrays produce a first light output and are mounted to partially face away from each other, wherein the first and second linear arrays project a majority of the first light output onto the front display panel at non-perpendicular angles relative to the front display panel;

the housing further includes a rear display panel having a second translucent indicia and opposing the front display panel, the LED lamp is disposed between the front and rear display panels; and

the elongated lamp frame further comprises;

a rear face having a V-shaped cross-section; and

third and fourth linear arrays of light emitting diodes mounted on the rear face and extending substantially parallel to the longitudinal axis, the third and fourth linear arrays produce a second light output and are mounted to partially face away from each other so that the third and fourth linear arrays project a majority of the second light output onto the rear display panel at non-perpendicular angles relative to the rear display panel.

19. An illuminated sign, comprising:

a housing with a front display panel that has a first translucent indicia portion;

an LED lamp disposed adjacent the front display panel, the LED lamp including;

a lamp base,

an elongated lamp frame having a longitudinal axis and a front face, and

first and second linear arrays of light emitting diodes mounted on the front face and extending substantially parallel to the longitudinal axis, the first and second linear arrays produce a first light output and are mounted to partially face toward each other, wherein the first and second linear arrays project a majority of the first light output onto the front display panel at non-perpendicular angles relative to the front display panel, and

third and fourth linear arrays of light emitting diodes mounted on the front face and extending substantially parallel to the longitudinal axis, wherein the front face has a W-shaped cross-section such that the first and second linear arrays partially face toward each other and the third and fourth linear arrays partially face away from each other, and wherein the third and fourth linear arrays produce a second light output and project a majority of the second light output onto the front display panel at non-perpendicular angles relative to the front display panel.

20. The illuminated sign of claim 19, wherein:

the housing further includes a rear display panel having a second translucent indicia and opposing the front display panel, the LED lamp is disposed between the front and rear display panels; and

the elongated lamp frame further comprises;

a rear face having a W-shaped cross-section; and

a plurality of linear arrays of light emitting diodes that produce a third light output and each are mounted on the rear face and extending substantially parallel to the longitudinal axis, wherein at least two of the plurality of linear arrays are mounted to partially face toward each other, and at least two other of the plurality of linear arrays are mounted to partially face away from each other, such that the plurality of linear arrays project a majority of the third light output onto the rear display panel at non-perpendicular angles relative to the rear display panel.

21. An illuminated sign, comprising:

a housing with a front display panel that has a first translucent indicia portion;

an LED lamp disposed adjacent the front display panel, the LED lamp including;

a lamp base,

an elongated lamp frame having a longitudinal axis and a front face, and

first and second linear arrays of light emitting diodes mounted on the front face and extending substantially parallel to the longitudinal axis, the first and second linear arrays produce a first light output and are mounted to partially face toward or partially face away from each other, wherein the first and second linear arrays project a majority of the first light output onto the front display panel at non-perpendicular angles relative to the front display panel;

at least one of the light emitting diodes from each of the first and second linear arrays are oriented to point in a direction toward the lamp base, and at least another one of the light emitting diodes from each of the first and second linear arrays are oriented to point in a direction away from the lamp base, such that the first light output projected by the first and second linear arrays evenly illuminates a portion of the front display panel that is longer than a length of the first and second linear arrays.

22. An illuminated sign, comprising:

a housing with a front display panel that has a first translucent indicia portion and a rear display panel that has a second translucent indicia; and

a first LED lamp disposed between the front and rear display panels, the first LED lamp including;

a lamp base,

an elongated lamp frame having a longitudinal axis and planar front and rear faces that are substantially parallel to each other,

at least one linear array of light emitting diodes producing a first light output and mounted on the front face and extending substantially parallel to the longitudinal axis, and

a plurality of linear arrays of light emitting diodes producing a second light output that is greater than the first light output and mounted on the rear face and extending substantially parallel to the longitudinal axis;

wherein the first LED lamp is disposed away from a center position of the housing and oriented with the rear face facing toward the center position of the housing and the front face facing away from the center position of the housing so that the first and second light outputs are projected onto the front and rear display panels at non-perpendicular angles relative to the front and rear display panels.

23. The illuminated sign of claim 22, further comprising:

a second LED lamp disposed between the front and rear display panels, the second LED lamp including;

a lamp base,

an elongated lamp frame having a longitudinal axis and planar front and rear faces that are substantially parallel to each other,

at least one linear array of light emitting diodes producing a first light output and mounted on the front face and extending substantially parallel to the longitudinal axis, and

a plurality of linear arrays of light emitting diodes producing a second light output that is greater than the first light output and mounted on the rear face and extending substantially parallel to the longitudinal axis;

wherein the second LED lamp is disposed on an opposite side of the housing center position as is the first LED lamp and oriented with its rear face facing the housing center position and the rear face of the first LED lamp so that the first and second light outputs from the second LED lamp are projected onto the front and rear display panels at non-perpendicular angles relative to the front and rear display panels.