AU749304B2

AU749304B2 - LED illuminated lamp assembly

Info

Publication number: AU749304B2
Application number: AU36374/00A
Authority: AU
Inventors: Chi-Tang Hsieh; Po-Laung Huang; Chan-Ching Lin
Original assignee: Ahead Optoelectronics Inc
Current assignee: Ahead Optoelectronics Inc
Priority date: 2000-05-23
Filing date: 2000-05-23
Publication date: 2002-06-20
Anticipated expiration: 2020-05-23
Also published as: AU3637400A

Description

It I, P/00/0011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: Actual Inventors: Address for service in Australia: Invention Title: AHEAD OPTOELECTRONICS, INC.

Chi-Tang HSIEH, Po-Laung HUANG and Chan-Ching LIN FREEHILLS CARTER SMITH BEADLE 101 Collins Street Melbourne Victoria 3000 Australia LED ILLUMINATED LAMP ASSEMBLY The following statement is a full description of this invention, including the best method of performing it known to us LED ILLUMINATED LAMP ASSEMBLY The invention relates to a lamp assembly, more particularly to an LED illuminated lamp assembly.

Conventional traffic signal lamps or illuminated overhead road signs utilize incandescent light bulbs as a light source. Generally, incandescent light bulbs require much greater power and burn out more frequently than light emitting diodes. Thus, incandescent light bulbs require more frequent replacement. Furthermore, conventional traffic signal lamps utilizing incandescent light bulbs are generally designed to radiate light along a central horizontal axis of incandescent light bulbs. Since only a portion of light power radiating from incandescent light bulbs under the central horizontal axis is received by drivers or pedestrians, undesired waste results due to light power radiating from incandescent light bulbs above the central horizontal axis.

Typically, the radiant power of light emitting diodes is severely limited such that they have been used primarily for short-range applications, such as panel indicators or indoor signs. Longer distances, brighter ambient light conditions, and limits of resolution of human eyes are among factors which should be considered S 25 when employing light emitting diodes for outdoor use.

In U.S. Patent No. 5,174,649, there is disclosed an LED lamp having a refractive lens element whose exit surface is formed with an array of facets configured to provide a desired beam spread pattern. However, this design has drawbacks in that, due to the facets, dirt, oil and other debris easily collects on the exit surface, which interferes with the light output when the LED lamp is used in exterior lighting applications.

In U.S. Patent No. 5,833,355, there is disclosed an LED illuminated lamp assembly having an entrance surface formed with a plurality of horizontal bands, each of which includes an upper region and lower region. The upper region includes a complex surface which can refract downward an upper portion of light radiating from a light emitting diode. The lower region includes a plurality of vertical grooves which can direct a lower portion of the light radiating from the light emitting diode to a desired horizontal direction. However, the design as such lacks flexibility and is severely limited by the shape of the horizontal bands. Thus, effective regulation of light cannot be ensured.

Therefore, the present invention desirably provides a lamp assembly which can overcome the aforementioned drawbacks that are commonly associated with the aforesaid prior art.

According to one aspect of the present invention, there is provided a lamp assembly comprising: a light beam source for generating a light beam; and a lens unit disposed in front of the light beam source, the lens unit having opposite entrance and exit surfaces, the entrance surface receiving the light beam from the light beam source and having top and bottom 25 ends spaced apart from each other in a vertical direction, and left and right sides opposite to each other in a horizontal direction, the entrance surface being defined by a plurality of horizontal band sections that are arranged in succession along the vertical S 30 direction and that extend from the left side to the right side, the horizontal band sections forming different angles with a horizontal plane such that a portion of the light beam from the light beam source is refracted downward as the light beam propagates through ee the lens unit and exits the lens unit at the exit surface, the angles formed by the horizontal band sections with the horizontal plane increase in progression in the vertical direction from the bottom end to the top end; the lens unit further including horizontal propagation regulating means, extending in the vertical direction, for regulating propagation of the light beam through the lens unit in the horizontal direction.

According to another aspect of the present invention there is provided an LED illuminated lamp assembly comprising: a circuit board assembly including a plurality of rows of light emitting diodes; and a lens device mounted on the circuit board assembly and including a plurality of lens units, each of which is associated with at least one of the light emitting diodes and has opposite entrance and exit surfaces, the entrance surface receiving light beam from the associated at least one of the light emitting diodes and having top and bottom ends spaced apart from each other in a vertical direction, and left and right sides opposite to each other in a horizontal direction, the entrance surface being defined by a plurality of ii:. 25 horizontal band sections that are arranged in succession along the vertical direction and that extend from the left side to the right side, the horizontal band sections forming different angles with a horizontal plane such that a portion of the light beam from the 30 associated at least one of the light emitting diodes is refracted downward as the light beam propagates through the lens unit and exits the lens unit at the exit surface, the angles formed by the horizontal band sections with the horizontal plane increase in g progression in the vertical direction from the bottom end to the top end; and each of the lens units further including horizontal propagation regulating means, extending in the vertical direction, for regulating propagation of the light beam through the lens units in the horizontal direction.

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which: Figure 1 is a partly exploded perspective view of the first preferred embodiment of an LED illuminated lamp assembly according to this invention; Figure 2 is a perspective view of the first preferred embodiment; Figure 3 is a perspective view showing a part of the lens units and the associated light emitting diodes of the first preferred embodiment; Figure 4 is a fragmentary perspective view illustrating how a light beam from the associated light emitting diode is refracted in a vertical direction through the lens unit of the first preferred embodiment; Figure 5 is a fragmentary perspective view illustrating how a light beam from the associated light 25 emitting diode is regulated in a horizontal direction *o through the lens unit of the first preferred embodiment; Figure 6 is a perspective view illustrating how a light beam from the associated light emitting diode is regulated in a horizontal direction through a lens unit of the second preferred embodiment according to this invention; Figure 6A is an enlarged view of an encircled portion of Figure 6; and Figure 7 is a perspective view illustrating how a light beam from the associated light emitting diode is regulated in a horizontal direction through a lens unit of the third preferred embodiment according to this invention.

Before the present invention is described in greater detail, it should be noted that like elements are denoted by the same reference numerals throughout the disclosure.

Referring to Figure i, according to the first preferred embodiment of this invention, an LED illuminated lamp assembly is shown to include a circuit board assembly and a lens device.

The circuit board assembly includes a lamp seat 2 having an open front end portion 20, a circuit board 3 having a front surface 31 and a rear surface 33 mounted on the front end portion 20 of the lamp seat 2, a plurality of rows of light emitting diodes 32 provided on the front surface 31 of the circuit board 3, and a lens seat 4 disposed in front of the circuit board 3.

The front end portion 20 of the lamp seat 2 is formed with a plurality of engaging holes 23 at a periphery thereof. The circuit board 3 is formed with a plurality of through holes 30 aligned with the engaging holes 23.

The lens seat 4 has an open rear end portion 43 mounted 1: 25 on the circuit board 3, and a front lens mounting portion which has an inner surface 41 facing the front :surface 31 of the circuit board 3 and an outer surface S.42. The outer surface 42 is a smooth and flat surface.

The rear end portion 43 of the lens seat 4 is formed 30 with a plurality of fastener holes 40 aligned with the through holes 30 in the circuit board 3 and the engaging holes 23 in the lamp seat 2. A plurality of fasteners 6 extend through the fastener holes 43 in the rear end :.':"portion 43 of the lens seat 4 and the through holes in the circuit board 3, and engage the engaging holes 23 in the front end portion 20 of the lamp seat 2, respectively, for securing the circuit board 3 between the lamp seat 2 and the lens seat 4, as shown in Figure 2.

The lens device is mounted on the inner surface 41 of the front lens mounting portion of the lens seat 4.

The lens device includes a plurality of lens units As shown in Figure 3, each of the lens units 5 is a unitary lens piece, which is hexagonal in shape.

Adjacent ones of the lens units 5 are in tight contact with one another. Each of the lens units 5 is associated with one of the light emitting diodes 32, and has opposite entrance and exit surfaces 52, 53. The exit surface 53 is a smooth and flat surface. The entrance surface 52 receives a light beam from the associated one of the light emitting diodes 32, and has top and bottom ends 521, 522 spaced apart from each other in a vertical direction, and left and right sides 523, 524 opposite to each other in a horizontal direction. The entrance surface 52 is defined by a plurality of horizontal band sections 500, 501, 502, 503, 504 that are arranged in succession along the vertical direction and that extend from the left side 523 to the right side 524. As shown i i 25 in Figure 4, the horizontal band sections 500, 501, 502, 503, 504 form different angles (01, 02, 03, 04, 05) with a horizontal plane such that a portion of light beam S. from the associated one of the light emitting diodes 32 is refracted downward as the light beam propagates 30 through the lens unit 5, and exits the lens unit 5 at the exit surface 53. The angles 02, 03, 04, -"formed by the horizontal band sections 500, 501, 502, 503, 504 with the horizontal plane increase in o progression in the vertical direction from the bottom T. R.I end 522 to the top end 521. That is, 01>02>03>04>05. The entrance surface 52 is further defined by a plurality of vertical band sections 510, 511, 517, 518 that are arranged in succession along the horizontal direction and that extend from the top end 521 to the bottom end 522 to intersect the horizontal band sections 500, 501, 502, 503, 504. As shown in Figure 5, the vertical band sections 510, 517, 518 have different degrees (Cl, C2, C3, C7, C8, C9) of curvature, and serve as a horizontal propagation regulating means for regulating propagation of the light beam through the lens unit 5 in the horizontal direction. The degrees (C1, C2, C7, C8, C9) of curvature of the vertical band sections 510, 517, 518 are gradually reduced in the horizontal direction from either one of the left and right sides 523, 524 to a central vertical axis of the lens unit 5. That is, C1>C2>C3>C4>C5, and C9>C8>C7>C6>C5.

Figure 6 illustrates a lens unit 5' of the second preferred embodiment of an LED illuminated lamp assembly according to this invention, which is a modification of the first preferred embodiment. Unlike the previous embodiment, each of the lens units 5' includes a first lens piece 50' formed with the horizontal band sections S 25 500', 501', 502', 503', 504', and a second lens piece 51' disposed parallel to the first lens piece 50' and formed with the vertical band sections 510' (see Figure S. 6A). The second lens piece 51' is disposed in front of the first lens piece 50', and is formed with the 30 vertical band sections 510' at one side facing the first lens piece 50'. The vertical band sections 510' are S.arranged in succession along the horizontal direction, and extend between the top and bottom ends of the lens unit 5' and generally transverse to the horizontal band sections 500', 501', 502', 503', 504'. The vertical band sections 510' have different degrees of curvature and serve as the horizontal propagation regulating means.

Like the previous embodiment, the degrees of curvature of the vertical band sections 510' are gradually reduced in the horizontal direction from either one of the left and right sides of the lens unit 5' to a central vertical axis of the lens unit Figure 7 illustrates a lens unit 5" of the third preferred embodiment of an LED illuminated lamp assembly according to this invention, which is a modification of the second preferred embodiment. Unlike the previous embodiment, each of the lens units 5" includes a lens piece 50' formed with the horizontal band sections, and a diffraction grating plate 55 disposed parallel to the lens piece 50'. The diffraction grating plate 55 is disposed in front of the lens piece 50', and is formed with a plurality of vertical slots 550 that are arranged in succession along the horizontal direction and that extend between the top and bottom ends of the lens unit and generally transverse to the horizontal band sections of the lens piece 50'. The vertical slots 550 serve as the horizontal propagation regulating means.

Adjacent ones of the vertical slots 550 are spaced apart 25 at equal distances.

In the embodiments of this invention, the light emitting diodes have a beam angle of 600, with 80% of 00 the light power distributed within a 450 angle. The lens device is designed to regulate a 450 beam angle of the 30 light emitting diodes, which accounts for 80% of the total radiated light power. The remaining 20% of the o: radiated light power exits the lens device unregulated to minimized the presence of uneven brightness.

It is noted that the lens units employed in the LED *o illuminated lamp assembly of this invention refract downward a portion of the light beam in the vertical direction and regulate propagation of the light beam in the horizontal direction, and have a flexible design.

Furthermore, the outer surface 42 is smooth and flat to reduce collection of dirt, oil and other debris thereon.

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Claims

1. A lamp assembly comprising: a light beam source for generating a light beam; and a lens unit disposed in front of said light beam source, said lens unit having opposite entrance and exit surfaces, said entrance surface receiving the light beam from said light beam source and having top and bottom ends spaced apart from each other in a vertical direction, and left and right sides opposite to each other in a horizontal direction, said entrance surface being defined by a plurality of horizontal band sections that are arranged in succession along the vertical direction and that extend from said left side to said right side, said horizontal band sections forming different angles with a horizontal plane such that a portion of the light beam from said light beam source is refracted downward as the light beam propagates through said lens unit and exits said lens unit at said exit surface, the angles formed by said horizontal band sections with the horizontal plane increase in progression in the vertical direction from said bottom end to said top end; 25 said lens unit further including horizontal L propagation regulating means, extending in the vertical direction, for regulating propagation of the light beam through said lens unit in the horizontal direction. 30 2. The lamp assembly of Claim 1, wherein said entrance surface is further defined by a plurality of vertical band sections that are arranged in succession along the S: horizontal direction and that extend from said top end to said bottom end to intersect said horizontal band sections, said vertical band sections having different degrees of curvature and serving as said horizontal propagation regulating means.

3. The lamp assembly of Claim 2, wherein the degrees of curvature of said vertical band sections are gradually reduced in the horizontal direction from either one of said left and right sides to a central vertical axis of said lens unit.

4. The lamp assembly of Claim i, wherein said lens unit is a unitary lens piece. The lamp assembly of Claim 4, wherein said lens piece is hexagonal in shape.

6. The lamp assembly of Claim i, wherein said lens unit includes: a first lens piece formed with said horizontal band sections; and a second lens piece disposed parallel to said first lens piece and formed with said horizontal propagation regulating means. 25 7. The lamp assembly of Claim 6, wherein said second a. lens piece is disposed in front of said first lens piece go and is formed with a plurality of vertical band sections

99., at one side facing said first lens piece, said vertical band sections being arranged in succession along the 30 horizontal direction and extending between said top and oo S: bottom ends and generally transverse to said horizontal a. a. o band sections, said vertical band sections having different degrees of curvature and serving as said hpo. *oo. horizontal propagation regulating means. 8. The lamp assembly of Claim 7, wherein the degrees of curvature of said vertical band sections are gradually reduced in the horizontal direction from either one of said left and right side to a central vertical axis of said lens unit. 9. The lamp assembly of Claim i, wherein said lens unit includes: a lens piece formed with said horizontal band sections; and a diffraction grating plate disposed parallel to said lens piece and formed with said horizontal propagation regulating means. The lamp assembly of Claim 9, wherein said diffraction grating plate is disposed in front of said lens piece and is formed with a plurality of vertical slots that are arranged in succession along the horizontal direction and that extend between said top and bottom ends and generally transverse to said horizontal band sections, said vertical slots serving as said horizontal propagation regulating means. 25 11. The lamp assembly of Claim 10, wherein adjacent eee ones of said vertical slots are spaced apart at equal distances. e e 12. The lamp assembly of Claim i, wherein said exit S: 30 surface is a smooth surface. *e gee 13. The lamp assembly of Claim 12, wherein the smooth g surface is a flat surface. ,oo *g* o 14 14. The lamp assembly of Claim i, wherein said light beam source is a light emitting diode. An LED illuminated lamp assembly comprising: a circuit board assembly including a plurality of rows of light emitting diodes; a lens device mounted on said circuit board assembly and including a plurality of lens units, each of which is associated with at least one of said light emitting diodes and has opposite entrance and exit surfaces, said entrance surface receiving light beam from the associated at least one of said light emitting diodes and having top and bottom ends spaced apart from each other in a vertical direction, and left and right sides opposite to each other in a horizontal direction, said entrance surface being defined by a plurality of horizontal band sections that are arranged in succession along the vertical direction and that extend from said left side to said right side, said horizontal band sections forming different angles with a horizontal plane such that a portion of the light beam from the associated at least one of said light emitting diodes is refracted downward as the light beam propagates through said lens unit and exits said lens unit at said exit 25 surface, the angles formed by said horizontal band sections with the horizontal plane increase in :progression in the vertical direction from said bottom end to said top end; and each of said lens units further including horizontal propagation regulating means, extending in 000 the vertical direction, for regulating propagation of eoee the light beam through said lens units in the horizontal direction. oo e o* 0 *i 0 9 16. The LED illuminated lamp assembly of Claim wherein said entrance surface is further defined by a plurality of vertical band sections that are arranged in succession along the horizontal direction and that extend from said top end to said bottom end to intersect said horizontal band sections, said vertical band sections having different degrees of curvature and serving as said horizontal propagation regulating means. 17. The LED illuminated lamp assembly of Claim 16, wherein the degrees of curvature of said vertical band sections are gradually reduced in the horizontal direction from either one of said left and right sides to a central vertical axis of said lens unit. 18. The LED illuminated lamp assembly of Claim wherein each of said lens units is a unitary lens piece. 19. The LED illuminated lamp assembly of Claim 18, wherein said lens piece is hexagonal in shape. The LED illuminated lamp assembly of Claim 19, wherein adjacent ones of said lens units are in tight contact with one another. 25 21. The LED illuminated lamp assembly of Claim wherein each of said lens units includes: a first lens piece formed with said horizontal band sections; and a second lens piece disposed parallel to said first 30 lens piece and formed with said horizontal propagation regulating means. r 22. The LED illuminated lamp assembly of Claim 21, wsee wherein said second lens piece is disposed in front of St 16 said first lens piece and is formed with a plurality of vertical band sections at one side facing said first lens piece, said vertical band sections being arranged in succession along the horizontal direction and extending between said top and bottom ends and generally transverse to said horizontal band sections, said vertical band sections having different degrees of curvature and serving as said horizontal propagation regulating means. 23. The LED illuminated lamp assembly of Claim 22, wherein the degrees of curvature of said vertical band sections are gradually reduced in the horizontal direction from either one of said left and right sides to a central vertical axis of said lens unit. 24. The LED illuminated lamp assembly of Claim wherein each of said lens units includes: a lens piece formed with said horizontal band sections; and a diffraction grating plate disposed parallel to said lens piece and formed with said horizontal propagation regulating means. 25 25. The LED illuminated lamp assembly of Claim 24, i wherein said diffraction grating plate is disposed in front of said lens piece and is formed with a plurality *of vertical slots that are arranged in succession along the horizontal direction and that extend between said 30 top and bottom ends and generally transverse to said horizontal band sections, said vertical slots serving as e said horizontal propagation regulating means. S *aoe 26. The LED illuminated lamp assembly of Claim wherein adjacent ones of said vertical slots are spaced apart at equal distances. 27. The LED illuminated lamp assembly of Claim wherein said exit surface is a smooth surface. 28. The LED illuminated lamp assembly of Claim 27, wherein the smooth surface is a flat surface. 29. The LED illuminated lamp assembly of Claim wherein adjacent ones of said lens units are in tight contact with one another. A lamp assembly substantially as hereinbefore described with reference to the accompanying drawings. 31. A LED illuminated lap assembly substantially as hereinbefore described with reference to the accompanying drawings. 25 Dated 28 March 2002 L: Freehills Carter Smith Beadle e. Patent Attorneys for the Applicant AHEAD OPTOELECTRONICS, INC S.