阅读说明：本技术 用于警示灯的光学系统 (optical system for warning lamp ) 是由 T·J·史密斯 于 2018-03-13 设计创作，主要内容包括：一种LED光学组件,包括LED、透镜和反射器。所述透镜由围绕旋转轴旋转的光入射面和光发射面组成。所述反射器具有成对的第一反射面和成对的第二反射面。所述第一反射面由绕所述旋转轴旋转的第一曲线限定。所述第二反射面由沿所述旋转轴投影的第二曲线限定。所述透镜和反射器配合以将LED发射的光重定向为垂直地准直广角光束。(An LED optical assembly includes an LED, a lens, and a reflector. The lens is composed of a light incident surface and a light emitting surface that rotate around a rotation axis. The reflector has a pair of first reflective surfaces and a pair of second reflective surfaces. The first reflective surface is defined by a first curve that rotates about the axis of rotation. The second reflective surface is defined by a second curve projected along the axis of rotation. The lens and reflector cooperate to redirect light emitted by the LED into a vertically collimated wide angle beam.)

1. An LED optical assembly comprising:

a Light Emitting Diode (LED) including a light emitting die in a first plane and having an optical axis extending from the light emitting die perpendicular to the first plane, the LED emitting light in a hemisphere centered on the optical axis on one side of the first plane;

A lens having a light incident surface and a light emitting surface that rotate about a rotation axis, the rotation axis being located in a second plane perpendicular to the first plane, and including an optical axis; and

a reflector having a pair of first reflecting surfaces intersecting the second plane and a pair of second reflecting surfaces intersecting the third plane, the first reflecting surfaces being defined by a first curve rotated about the rotation axis, the second reflecting surfaces being defined by a second curve projected along the rotation axis, and the third plane including the optical axis and being perpendicular to the first plane and the second plane;

Wherein the light incident surface and the light emitting surface cooperate to redirect light incident from the light incident surface and emitted from the LED into a plane parallel to the third plane, the first reflecting surface redirects light incident from the first reflecting surface and emitted from the LED into a plane parallel to the third plane, and the second reflecting surface redirects light incident from the second reflecting surface and emitted from the LED into a plane parallel to the second plane.

2. The LED optical assembly of claim 1, wherein light redirected by the second reflective surface is substantially collimated relative to the optical axis.

3. the LED optical assembly of claim 1, further comprising a plurality of optical units, each optical unit comprising an LED, a lens, and a reflector.

4. the LED optical assembly of claim 3, wherein each optical unit has a plurality of LEDs.

5. The LED optical assembly of claim 4, wherein in each optical unit, the plurality of LEDs emit at least two different colors of light, and the plurality of LEDs are arranged in a sequence with optical axes extending perpendicularly from a focal axis.

6. The warning light of claim 5, wherein the order of the plurality of LEDs along the focal axis is different in adjacent optical units.

7. The LED optical assembly of claim 4, wherein the plurality of LEDs are arranged to emit a first light emission pattern that redirects substantially all light emitted by the LEDs into a trajectory parallel to the optical axis or a second light emission pattern that redirects substantially all light emitted from the LEDs into a plane parallel to the third plane.

8. the LED optical assembly according to claim 1, wherein the first curve has a first focus point comprising a point of convergence, the second curve has a second focus point comprising the point of convergence, and the point of convergence is located at an intersection of the optical axis and the rotational axis.

9. A warning light, comprising:

A plurality of adjacent cells, each cell comprising a lens, a reflector, and at least one LED;

the LED includes a light emitting die lying in a first plane and having an optical axis extending from the light emitting die perpendicular to the first plane, the LED emitting light in a hemisphere centered on the optical axis on one side of the first plane;

The lens has a light incident surface and a light emitting surface that rotate around a rotation axis; and is

The reflector has a pair of first reflective surfaces defined by a first curve rotated about the axis of rotation and a pair of second reflective surfaces defined by a second curve projected along the axis of rotation; wherein the lens and the reflector cooperate to redirect light emitted from the LED into a plane parallel to the second plane.

10. The warning light of claim 9, wherein the light redirected by the second reflective surface is substantially collimated relative to the optical axis.

11. the warning light of claim 9, further comprising a plurality of LEDs in each cell.

12. The warning light of claim 11, wherein in each cell the plurality of LEDs emit light of at least two different colors and the plurality of LEDs are arranged in a sequence with optical axes extending perpendicularly from a focal axis.

13. The warning light of claim 12, wherein the order of the plurality of LEDs along the focal axis is different in adjacent optical units.

14. The warning light of claim 9, wherein light emitted from the LED is redirected to substantially fill the cell.

15. The warning light of claim 9, further comprising a plurality of LEDs in each cell, the plurality of LEDs arranged to emit a first light emission pattern or a second light emission pattern;

Wherein the first light emission mode redirects substantially all light emitted by the LED into a trajectory parallel to the optical axis, and the second light emission mode redirects substantially all light emitted from the LED into a plane parallel to the second plane.

16. An LED optical assembly comprising:

a plurality of Light Emitting Diodes (LEDs), each light emitting diode comprising a light emitting die lying in a first plane and having an optical axis extending from the light emitting die perpendicular to the first plane, the LEDs emitting light in a hemisphere centered on the optical axis on one side of the first plane, each optical axis being arranged on a focal axis in the first plane;

A lens having a light incident surface and a light emitting surface that rotate about a rotation axis and including an optical axis, the rotation axis being located in a second plane perpendicular to the first plane; and

a reflector having a pair of first reflective surfaces defined by a first curve rotated about the axis of rotation and a pair of second reflective surfaces defined by a second curve projected along the axis of rotation;

Wherein the light incident surface and the light emitting surface cooperate to redirect light incident from the light incident surface and emitted from the LED into a plane parallel to the third plane, the first reflecting surface redirects light incident from the first reflecting surface and emitted by the LED into a plane parallel to the third plane, and the second reflecting surface redirects light incident from the second reflecting surface and emitted by the LED into a plane parallel to the second plane.

17. The LED optical assembly of claim 16, wherein light redirected by the second reflective surface is substantially collimated relative to the optical axis.

18. The LED optical assembly according to claim 16, wherein the first curve has a first focus point including a point of convergence, the second curve has a second focus point including the point of convergence, and the point of convergence is at an intersection of the optical axis and the rotational axis.

19. the LED optical assembly of claim 16, wherein the plurality of LEDs emit light of at least two different colors.

20. The LED optical assembly of claim 16, wherein the plurality of LEDs are arranged to emit a first light emission pattern that redirects substantially all light emitted by the LEDs into a trajectory parallel to the optical axis or a second light emission pattern that redirects substantially all light emitted from the LEDs into a plane parallel to the third plane.

background

The present disclosure relates generally to optical systems for distributing light from a light source, and more particularly to an optical system for redirecting the light output of an LED to a vertically collimated wide angle beam of light.

Commercially available LEDs have a characteristic spatial radiation pattern relative to the optical axis through the light emitting die. A common feature of all LED radiation patterns is that light is emitted from one side of the plane containing the light emitting dies around the LED optical axis in a pattern perpendicular to the plane. The light generated by the LED radiates within a hemisphere centered on the optical axis. The distribution of the light radiation within the hemisphere is dependent on the shape and optical characteristics of the lens (if any) that covers the LED light emitting die. Thus, LEDs can be described as "directional" light sources because all the light they produce is emitted from one side of the device.

when designing a light source for a particular purpose, it is important to maximize efficiency by ensuring that substantially all of the generated light is arranged in an illumination pattern or field determined by the end use of the device incorporating the light source.

The use of LEDs in warning lights and signaling lights is well known. Older LED models produce a limited amount of light within a relatively narrow viewing angle centered on the optical axis of the LED. These LEDs are typically grouped in a compact array to fill a given illumination area and provide the necessary light output. Each component of recently developed high output LEDs produces a significant increase in luminous flux; allowing fewer LEDs to produce the required luminous flux for many warning and signaling applications. It is known to arrange a small number of high output LEDs in a luminaire and provide an internally reflective collimating lens for each high output LED. The collimating lens organizes the light from the LED into a collimated beam centered on the LED's optical axis. Such an arrangement does not typically fill the luminaire, resulting in an undesirable appearance consisting of bright spots arranged in an unlit background. Light transmitting optics are sometimes used on the outer lens/cover to improve the appearance of the luminaire. It is also known to create a wide-angle light emission pattern by varying the position of the LEDs relative to the surface on which the luminaire is mounted. The inclined or spaced apart LEDs relative to the vertical surface can spread the light so that it can be seen from a number of vantage points.

this application will discuss an optical device for changing the emission trajectory of light from an LED relative to a reference line or plane. For the purposes of this application, "collimation" refers to "redirection to a trajectory substantially parallel to a reference line or plane". Substantially parallel refers to a trajectory that is within 5 ° of parallel to a reference line or plane. When discussing the collimation of light with respect to a plane, it should be understood that the components of the emission trajectory that diverge from the reference plane are modified such that the diverging components of the trajectory lie within 5 ° of being parallel to the reference plane, without modifying the components of the emission trajectory that are parallel to the reference plane. For LEDs mounted on a vertical surface, light is emitted in a hemispherical pattern centered on the optical axis of the LED perpendicular to the vertical surface, i.e., the optical axis of each LED is horizontal. If the LEDs are mounted in rows, the optical axes are included in the same horizontal plane, which is typically a horizontal reference plane. In this case, "vertical collimation" refers to redirecting light that deviates upward or downward from a horizontal reference plane (including the LED optical axis) to a direction substantially parallel to the horizontal plane. The vertically collimated light from each LED will be spread over an arc of approximately 180 deg. in the horizontal direction, assuming no other obstructions or changes in direction. The light of adjacent LEDs overlaps to produce a horizontal beam of light having a peak intensity many times that of any one LED.

There is a need in the art for an optical element that redirects light emitted from an LED into a vertically collimated, horizontally dispersed beam of light. This light dispersion mode needs to be accomplished while filling the fixture and mounting the light sources in a plane parallel to the mounting surface.

Overview of the device

According to one embodiment of the LED optical assembly of the present disclosure, the LED optical assembly includes a Light Emitting Diode (LED), a lens, and a reflector. The LED includes a light emitting die lying in a first plane and has an optical axis extending from the light emitting die perpendicular to the first plane. The LED emits light to one side of the first plane within a hemisphere centered on the optical axis. The lens is composed of a light incident surface and a light emitting surface which are located in a second plane and rotate around a rotation axis. The second plane is perpendicular to the first plane and the second plane includes the optical axis. The reflector has a pair of first reflective surfaces that intersect the second plane and a pair of second reflective surfaces that intersect the third plane. The first reflective surface is defined by a first curve that rotates about the axis of rotation. The second reflective surface is defined by a second curve projected along the axis of rotation. The third plane includes the optical axis and is perpendicular to the first plane and the second plane.

The light incident surface and the light emitting surface cooperate to redirect light incident from the light incident surface and emitted from the LED into a plane parallel to the third plane. The first reflective surface redirects light incident from the first reflective surface and emitted from the LED into a plane parallel to the third plane. The second reflective surface redirects light incident from the second reflective surface and emitted from the LED into a plane parallel to the second plane.

In another embodiment, the LED optical assembly includes a plurality of optical units, each optical unit including an LED, a lens, and a reflector. Each optical unit may have a plurality of LEDs. In some embodiments, the first curve has a first focus comprising a convergence point and the second curve has a second focus comprising the convergence point. The convergence point may be located at an intersection of the optical axis and the rotation axis.

Drawings

Fig. 1 is an isometric view of a warning lamp assembly according to aspects of the present disclosure;

FIG. 2A is an isometric exploded view of an optical system used in the warning lamp assembly of FIG. 1;

FIG. 2B is an isometric exploded view of the warning lamp assembly of FIG. 1;

FIG. 3A is a front view of the warning light assembly of FIG. 1;

FIG. 3B is a partial view of the optical system enclosed by the dashed circle in FIG. 3A;

FIG. 4A is a cross-sectional view of the warning lamp assembly of FIG. 3A taken along line 4-4;

FIG. 4B is a partial view of the optical system enclosed by the dashed circle in FIG. 4A;

FIG. 5A is a cross-sectional view of the warning lamp assembly of FIG. 3A taken along line 5-5;

FIG. 5B is a partial view of the optical system enclosed by the dashed circle in FIG. 5A;

FIG. 6A is a front view of a set of lenses used in the warning light assembly of FIG. 1;

FIG. 6B is a rear view of a set of lenses used in the warning light assembly of FIG. 1;

FIG. 7 is a graphical representation of a horizontal light emission pattern of the optical unit of FIG. 3A; and

Fig. 8 is a graphical representation of the vertical light emission pattern of the optical unit of fig. 3A.

Detailed Description

Embodiments of the compact multifunctional lamp cap will now be described with reference to the drawings, wherein like numerals refer to like parts throughout fig. 1-6B.

Fig. 1-3A illustrate a warning light assembly 100 including the disclosed optical system 10. Fig. 1 shows a warning light assembly 100 secured to a mounting surface 12, which may be a vertical surface of an emergency vehicle, such as a fire, ambulance or rescue vehicle. As shown in fig. 1, the warning lamp assembly 100 includes a lamp head 30 and a bezel 16 surrounding the lamp head 30. The lighthead 30 includes a rectangular array of 36 optical units 24, each rectangular array including at least one LED 34. As shown in fig. 3A, the optical units 24 are arranged in a 6 × 6 grid. Each optical unit 24 includes an optical system 10 to redirect light from at least one LED34 to a desired light emission pattern.

As will be described in more detail below, the desired light emission pattern is a vertically collimated wide angle beam of light. As used in this application, vertically collimated means that light emitted from the LED34 has a trajectory that is directed "up" or "down" in fig. 3A and 3B relative to the viewer's viewing angle, the light being redirected by refraction and/or reflection to a trajectory that is substantially aligned with a horizontal plane, designated as third plane P3 in fig. 3B. Light emitted from the LED34 has a trajectory that points "right" or "left" in fig. 3A relative to the viewer's perspective, the light being selectively redirected to a trajectory that is substantially aligned with a vertical plane, designated as the second plane P2 in fig. 3B. Most of the light emitted from each LED34 has a trajectory diverging from the second plane P2, which is not redirected with respect to the second plane P2, while some wide-angle light (light having a trajectory that diverges most widely from the second plane P2) is redirected onto a trajectory substantially aligned with the second plane P2. The resulting light emission pattern is vertically collimated with a wide horizontal angular spread so that the warning light is visible within a range of positions relative to the emergency vehicle.

As shown in fig. 2A-2B, the base 30 is composed of a cover 14, a reflector 70, a sealing member 32, a lens group 50, a PC board 36, and a heat radiating plate 38. As best shown in fig. 6A and 6B, lens assembly 50 has rearwardly facing alignment pins 62, which alignment pins 62 fit into corresponding openings in the front face of PC board 36 and align each lens 52 relative to LED34 of optical unit 24. In the illustrated embodiment, heat spreader plate 38 includes openings for electrical wires extending rearward from PC board 36, and fasteners extending forward through PC board 36 to engage reflectors 70. Seal 32 is received in a groove around the rear of reflector 70 and engages heat spreader 38 to provide a weather-tight seal around lens 52 and PC board 36. A common thermal gasket 13 is sandwiched between PC board 36 and heat spreader plate 38 to electrically isolate PC board 36 from aluminum heat spreader plate 38 while providing a thermal path from LEDs 34 to heat spreader plate 38, as is known in the art. The lid 14 includes a rearwardly facing lip that is received in a corresponding recess of the reflector 70. An adhesive bead is injected into the groove prior to inserting the lid lip into the groove. In the illustrated embodiment, the cover 14 includes snap features that engage the reflector 70 to maintain a fixed relationship between the cover 14 and the reflector 70 as the adhesive cures. The fully assembled lamp head 30 provides a sealed enclosure for the PC board 36, lens assembly 50 and reflector 70.

fig. 3A shows an array 22 comprising identical optical units 24, each having an optical system 10. Fig. 3B shows one optical element 24 in more detail (enclosed by the dashed circle in fig. 3A). Each optical system 10 includes an LED34 (shown in fig. 4B), which LED34 emits light through the lens 52 and is surrounded by a pair of first reflective surfaces 72 above and below the third plane P3 and a pair of second reflective surfaces 74 on the left and right sides of the second plane P2. With reference to fig. 4A-5B below, details of lens 52 and reflector 70 are analyzed along the depicted section lines 4-4 and 5-5.

Fig. 4A shows a cross-section of the lamp head 30 along the line 4-4 of fig. 3A. The lens 52 and reflector 70 are shown in more detail in fig. 4B. Each LED34 has an optical axis 40 and a light emitting die that lies in a first plane P1. The LED34 emits light in a hemisphere centered on the optical axis 40 on one side of the first plane P1. The convergence point 42 is located at the intersection of the optical axis 40 and the axis of rotation 44 in the first plane P1. The LEDs 34 are mounted to the PC board 36, the PC board 36 providing power and having a thermal path to allow heat to dissipate into the heat sink 38 (not shown). PC board 36 is parallel to first plane P1. The second plane P2 includes the axis of rotation 44 and is perpendicular to the first plane P1. The third plane P3 includes the optical axis 40 and is perpendicular to the first plane P1 and the second plane P2.

Referring to FIG. 4B, the first reflective surface 72 intersects the second plane P2 and is defined by a first curve that rotates about the rotational axis 44. In the illustrated embodiment, the first curve has a first focal point at the convergence point 42. Light emitted by the LED34 from the axis of rotation 44 that is less than alpha is redirected by the first reflective surface 72. In the embodiment shown, α is about 40 °. The lens 52 is defined by a light incident surface 54, a light emitting surface 56, and a transition surface 58. In the illustrated embodiment, these surfaces combine to form a solid optical element that rotates about an axis of rotation 44. The surfaces 54, 56, 58 of the lens 52 cooperate to cancel the vertical component of the light emitted by the LED34 that is incident on the light incident surface 54. The angle β of transition surface 58 with respect to rotational axis 44 may match the trajectory of light refracted through light entrance surface 54. In the illustrated embodiment, the angle β is about 68 °.

the first reflective surface 72 and the lens 52 eliminate the perpendicular component of the light emitted by the LED 34. In other words, the first reflective surface 72 and the lens 52 cooperate to redirect light emitted by the LED34 into a plane parallel to the third plane P3.

fig. 5A shows a cross-section of the lamp cap 30 along the line 5-5 of fig. 3A. The first and second reflective surfaces 72, 74 are clearly visible in this view and are shown in more detail in fig. 5B. The second reflective surface 74 intersects the third plane P3 and is defined by a second curve. The second curve is projected along the rotation axis 44 to form a second reflective surface 74. In the illustrated embodiment, the second curve has a second focal point that coincides with the convergence point 42. Second reflective surface 74 redirects light refracted by lens 52 or light reflected by first reflective surface 72 into a plane substantially parallel to second plane P2. As previously described, light refracted by the lens 52 or light reflected by the first reflective surface 72 is redirected into a plane parallel to the third plane P3. Thus, light emitted from the LED34 that is ultimately reflected by the second reflective surface 74 is generally collimated relative to the optical axis 40.

referring to fig. 6A and 6B, the lens group 50 includes a plurality of lenses 52 connected by a bracket 60. The illustrated light head 30 assembles three separate lens sets 50 to redirect light from the plurality of LEDs 34 on the PC board 36. Bracket 60 connects lenses 52 to each other and secures lens assembly 50 between reflector 70 and PC board 36 (as shown in fig. 4A and 5A). Pins 62 on the back of lens assembly 50 engage complementary holes in PC board 36 and position lens 52 relative to LED 34.

the embodiment shown has a single LED in each cell 24. In other embodiments, each cell 24 contains three individual LEDs 34 in the first plane P1 and the third plane P3, the LEDs 34 having optical axes 40 along the focal axis 46. The three LEDs 34 may emit different colors of light. Since there are multiple LEDs in each optical unit, only one LED may have an optical axis 40 that includes a focal point 42. Each optical unit 24 of array 22 may have LEDs of the same color as optical axis 40 including focal point 42, or adjacent groups of units may alternate LED positions to balance each color to produce a substantially similar light dispersion pattern for each color of LEDs.

in the illustrated embodiment, no light exits the lamp head 30 without redirection by at least one of the lens 52, the first reflective surface 72, or the second reflective surface 74. The reflective surfaces 72, 74 and lens 52 cooperate to produce a light dispersion pattern that fills the bezel 16, which is a vertically collimated wide-angle beam. Angle α or angle β may be different without significantly departing from the scope of this disclosure. This may allow light to escape the lamp cap 30 without redirection.

Fig. 7 and 8 graphically show the light emission pattern from the optical unit 24 in the horizontal direction and the vertical direction, respectively. The figure shows a vertically collimated light dispersion pattern with a wide horizontal angular spread. The horizontal dispersion allows adjacent cells 24 to form a continuous horizontal band of light to minimize hot spots in the lighthead 30.

Fig. 7 shows horizontal dispersion to a wide-angle beam. When presented graphically, the beam formed in the horizontal direction emits more light over an angular range diverging by up to about 48 ° relative to the optical axis 40. The emission pattern in the horizontal direction from the LED34 through the optical system 10 results in a wide-angle light emission pattern with strong emission aligned with the second plane P2.

fig. 8 shows vertical collimation, which corresponds to a vertically collimated beam of light of about 15 ° with respect to a 0 ° centre line, which coincides with the third plane P3. In other words, the emission pattern from the LED34 through the optical system 10 produces a light beam in which substantially all of the light is emitted at an angle of 15 ° or less in the vertical direction relative to the third plane P3. The maximum intensity of the light beam produced by the optical unit 24 in the vertical direction is at the center of the emission pattern, which when graphically represented resembles a relatively sharp, narrow spike aligned with the second and third planes P2 and P3.

While preferred embodiments have been set forth for the purpose of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations, and alternatives may occur to one skilled in the art without departing from the spirit and scope of the present invention as claimed.