LED optics system
11598504 · 2023-03-07
Assignee
Inventors
Cpc classification
F21S43/40
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S43/14
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S43/26
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S43/31
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S43/315
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21V7/0091
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21K9/68
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S41/141
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S43/15
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21V5/002
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21Y2115/10
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
Abstract
A LED-based lighting assembly uses minimized distance between an LED source and a diffuser to reduce form factor size, and convex optics, elliptical diffusion and lateral recycling to produce from mini- or micro-chip LEDs a uniform geometrical shape for lit-pixel display of information at high definition. A less than one-to-one (1:1) ratio of LED chip distance and vertical distance between chip and diffuser is achieved with desired uniformity of lit-pixel displays. Reduced distance between diffuser and LEDs and an improved optic provide for more dense yet compact configuration of LEDs in lighting components of automobile grilles and emblems and other lit branding or safety devices in commercial and residential applications.
Claims
1. A light emitting diode (LED)-based lighting assembly comprising: a light source comprising a plurality of LED chips chosen from mini-chip LEDs and microchip LEDs, wherein an x-direction corresponds to a length of a LED chip, a y-direction corresponds to a width of a LED chip, and a z-direction corresponds to a vertical distance from a LED chip, wherein pitch corresponds to a chip-to-chip distance between two LED chips in one of the x-direction and the y-direction; a diffuser having a diffuser input surface to receive light from the light source and a diffuser output surface to transform received light, the diffuser input surface disposed a selected distance in the z-direction from light output surfaces of the plurality of LED chips, wherein a less than one-to-one (1:1) ratio exists between the selected pitch and the selected z-direction; and an optic system arranged to receive light from the diffuser output surface and comprising: an optical element with a convex or a concave shape, the optical element including an optic input surface positioned a first distance from the light source in the z-direction and extending a first width in the x-direction and an optic output surface positioned a second distance from the light source in the z-direction and extending a second width in the x-direction, the second distance being greater than the first distance and the second width being greater than the first width; and a reflector element arranged to reflect and recycle received light, the reflector element extending above and below the optic input surface and the optic output surface in the z-direction, wherein the diffuser extends outwardly of the reflector element in the x-direction.
2. The LED-based lighting assembly of claim 1, wherein light output from the light source passes through an air gap before impinging on the diffuser input surface.
3. The LED-based lighting assembly of claim 1, wherein the optical element has a convex shaped lens input surface and a convex-shaped lens output surface.
4. The LED-based lighting assembly of claim 1, wherein the diffuser is an elliptical diffuser.
5. The LED-based lighting assembly of claim 4, wherein the diffuser output surface comprises a plurality of micro-elliptical elements having different aspect ratios.
6. The LED-based lighting assembly of claim 4, wherein the diffuser output surface comprises a plurality of lenslet features of varying heights.
7. The LED-based lighting assembly of claim 4, wherein the diffuser output surface comprises microstructures having varying features provided onto a silicone material.
8. The LED-based lighting assembly of claim 1, wherein the light source comprises a printed circuit board connected to the LED chips to power and control the LEDs, and a silicone coating on at least the light output surfaces of the LED chips.
9. The LED-based lighting assembly of claim 1, wherein the light source, the diffuser, and the optic system are flexible and curved.
10. The LED-based lighting assembly of claim 1, wherein the optic element is raised relative to a planar area and the optic system comprises a wall that encloses an optic input surface of the optical element, and the reflector element is disposed adjacent the wall to redirect light output from the diffuser toward the optic input surface.
11. The LED-based lighting assembly of claim 1, wherein the reflector element is separated from the diffuser output surface by a pair of flat surface portions of the optical element extending outwardly in the x-direction of the optic input surface and the optic output surface.
12. A method of making a light emitting diode (LED)-based lighting assembly comprising: arranging a light source comprising a plurality of LED chips chosen from mini-chip LEDs and micro-chip LEDs to create a selected pattern from the LED chips, wherein an x-direction corresponds to a length of a LED chip, a y-direction corresponds to a width of a LED chip, and a z-direction corresponds to a vertical distance from a LED chip, wherein pitch corresponds to a chip-to-chip distance between two LED chips in one of their x-direction and their y-direction, and wherein the plurality of LED chips are arranged at a selected pitch for a designated lighting effect from the selected pattern; electrically coupling the light source to a printed circuit board to power and control the LEDs; disposing a diffuser a selected distance relative to the light source, the diffuser having a diffuser input surface to receive light from the light source and a diffuser output surface to emit received light, a diffuser output surface having an elliptical diffuser portion; and coupling an optic system to the diffuser output surface to define a gap between the optic system and the diffuser outer surface with the elliptical diffuser portion encapsulated within the gap, the optic system configured to receive light from the diffuser, the optic system having an optical element with a convex shape and a reflector element to reflect and recycle received light from the diffuser toward an optic input surface of the optical element.
13. The method of making the LED-based lighting assembly of claim 12, further comprising providing a silicone coating on at least the light output surfaces of the LED chips.
14. The method of making the LED-based lighting assembly of claim 12, further comprising providing microstructures having varying features on the diffuser output surface.
15. The method of making the LED-based lighting assembly of claim 12, wherein the light source, the diffuser, and the optic system are flexible, and the selected pattern comprises a curve, and further comprising arranging the LED-based lighting assembly into the curved selected pattern.
16. The method of making the LED-based lighting assembly of claim 12, wherein the light source, the diffuser, and the optic system are flexible, and further comprising arranging the LED-based lighting assembly into a contoured shape that accommodates a selected mounting structure.
17. A light emitting diode (LED)-based lighting assembly comprising: a light source comprising a plurality of LED chips chosen from mini-chip LEDs and microchip LEDs, wherein an x-direction corresponds to a length of a LED chip, a y-direction corresponds to a width of a LED chip, and a z-direction corresponds to a vertical distance from a LED chip, wherein pitch corresponds to a chip-to-chip distance between two LED chips in one of the x-direction and the y-direction; a diffuser having a diffuser input surface to receive light from the light source and a diffuser output surface to transform received light; and an optic system arranged to receive light from the diffuser output surface and comprising: an optical element including an optic input surface extending a first width in the x-direction and an optic output surface extending a second width in the x-direction, the second width being greater than the first surface; and a reflector element arranged to reflect and recycle received light, the reflector element extending above and below the optic input surface and separated by one another by a third distance, the third distance being greater than the second distance.
18. The LED-based lighting assembly of claim 17, wherein the diffuser output surface has an elliptical diffuser portion.
19. The LED-based lighting assembly of claim 18, wherein a gap is defined between the optic system and the diffuser outer surface with the elliptical diffuser portion encapsulated within the gap.
Description
BRIEF DESCRIPTION OF DRAWINGS
(1) The accompanying drawings constitute a part of this specification and illustrate embodiments that, together with the specification, explain the subject matter.
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DETAILED DESCRIPTION
(15) The following detailed description is provided with reference to the figures. Exemplary embodiments are described to illustrate the disclosure, not to limit its scope, which is defined by the claims. Those of ordinary skill in the art will recognize equivalent variations in the description that follows without departing from the scope and spirit of the disclosure.
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(17) As shown in
(18) The system also comprises one or a plurality of packaged LEDs 102 mounted on Printed Circuit Board (“PCB”) 101. The LEDs 102 may be standard commercially available LED packages such as a 3030 packaged LED. The PCB 101 may be a standard PCB and may be manufactured from FR4, IMS, glass, or other similar components.
(19) Vertical reflectors 103 are oriented generally perpendicular to PCB 101 and designed to reflect light emitted from the LEDs 102 in a manner designed to (i) prevent light from escaping in a horizontal direction and (ii) permit light to be directed upward and away from the LEDs 102.
(20) Light diffuser 104 is positioned generally parallel to the PCB 101 and above the LEDs 102 and designed to diffuse light emitted from the LEDs 102. As discussed above, the light emitted from a LED must be diffused for the device to emit uniform light. In a typical device, the light diffuser 104 is spaced approximately 10 mm from the LED source 102 which increases form factor undesirably for many lighting applications.
(21) Typically, the geometry of light diffusers 104 include symmetrical micro valleys and hills of 20-250 μm in which the cross-section of an individual lenslet microstructure could be revolved around the centroid axis. The height and width of the lenslet microstructure primitive may be randomized, for example, to remove caustic formation.
(22) When light diffusers 104 are pulled further away from the LED light source 102, geometric resolution begins to wash out as angles of light begin to blend and skew rays mesh together. For example, light emerging from one pixel group merges with light emerging from an adjacent pixel group which may result in geometric and pictorial definition essentially becoming indiscernible. Decorative housing 105 is a decorative housing to the device. For example, in an automotive grille application, the lit grille piece may be translucent, chrome plated or gloss black.
(23) Optical lens 106 is a concave optical lens designed to spread incoming light in one general direction. Depending on the design, the overall thickness of the optical lens 106 may exceed 1″ (28 mm) at certain positions.
(24) In typical layouts, the system employs an LED light source 5-sided conformal phosphor chip having such specifications as 1.5-20 lm/LED, 3.5 mA, 10 mW, 5500K, with an x-direction pitch of 5.25 mm, a y-direction pitch of +/−5.0 mm, a 10 mm z-distance between the diffuser 104 and light source 102, and three rows of 20 columns of LEDs 102, as shown in
(25) To overcome the problems of the typical system, the present disclosure describes an improved LED-based lighting assembly in accordance with embodiments shown in
(26) Examples of how reduced x- or y-direction pitch and/or z-direction distance can impact performance will now be described with reference to
(27) TABLE-US-00001 TABLE 1 Peak Beam y-pitch +/− Lumens Intensity distribution (mm) Transmitted T % (cd) X/Y 5 43.5 48% 25.4 70/92 2.5 45.6 51% 29 64/92 1 47.2 52% 29.2 64/90
(28) Lumens transmitted represents the light which has successfully emerged from the light source 102 after passing through the diffuser 104, the recycler walls 103, and the outer concave lens 106. For this example, 90 lm are produced at the light source 102 as a part of a small section of the device (e.g., a lit grille application).
(29) T % represents the light which has successfully passed through the secondary optics including the elliptical diffuser 104, the lens reflector recycler 103 and the outer concave lens 106. For example, at a y-direction pitch of +/2.5 mm, the T % is a ratio of the lumens transmitted (45.6 lm) and the lumens produced at the LED light source (90.0 lm) which is 45.6/90 or 51%. Efficiency of transmitted light increases as the y-direction pitch is decreased.
(30) Beam distribution X/Y represents the full width half maximum of the distribution of the light in the x-direction and the y-direction in which the x-direction is along the longer L dimension of the bar of light, and the y-direction is transverse to the longer dimension. The light which emerges can be changed to be stronger in one direction than the other depending ultimately on the elliptic orientation and strength of the diffuser used.
(31) Depending on the desired system performance, different y-pitch may be employed. For example, if single and more intensity points of light are desired, then the system may be designed at +/−1 mm. Conversely, if more controllable points of light are desired, such as for depicting messages or more complex designs, then y-direction pitch of +/−2.5 mm may be employed.
(32) Similarly, system optical efficiency increases with diminished z-direction distance (i.e., the distance between the LED 102 and the diffuser 104). For example, as shown in Table 2 (
(33) TABLE-US-00002 TABLE 2 z-dist (mm) lumens T T % 0.5 45.6 51% 2.5 38 42% 4.5 35.6 40% 6.5 31.9 35% 8.5 29 32%
(34) Thus, the illumination appearance uniformity improves at the cost of reduced system optical efficiency with increased diffusion.
(35) Further, reduced x-direction pitch preserves light columns. As shown in
(36) As shown in
(37) Conversely, as shown in
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(39) Silicone coating 1302 is a silicone conformal coating to help extract light from the LED chips 1301 and protect the conformal coating and chips from outside environment.
(40) Diffuser 1303 is an elliptical diffuser placed within 0.5 mm z-direction distance of the LED mini chips 1301, for example.
(41) Surface 1304 is a representation of the planar outer surfaces of the optical lens 1308 and absorbs light.
(42) Incident surface 1305 is the incident surface of the concave portion of the lens system 1308. Reflectors 1306 are reflectors attached directly to the outer walls of the optical lens 1308 to recycle incoming light and to improve uniformity. The reflectors 106 may be applied directly to the outer side surfaces of the optical lens 1308 or the inner surface of the decorative housing (not shown). Direct attachment to the optical lens 1308 without an air gap is preferable for highest recycling efficiency. Outer surface 1307 is the outer surface of the concave optic and it has micro-texture to help homogenize the light.
(43) The space saving in the z-direction as per
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(45) To account for the minimized x-pitch, y-pitch, and z-distance, the present disclosure utilizes an improved elliptical diffuser 1600.
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(47) The 1603b microstructure represents a 60×10 deg micro diffuser lens feature, and 1603c microstructure represents a more aggressive aspect ratio of microstructure which can produce 80×1 deg ellipticity. The soft diffusion direction of the microstructure 1603b only spreads the beam by 1-20 deg. The more aggressive lenslets of microstructure 1603c diffuse in the transverse direction 30-80 deg.
(48) To avoid imaging caustics which may result, the elliptical micro-lenslet structure of the diffuser 1603 can be interspersed by symmetrically diffusing but randomly varied height lenslet features. These features can be holographically etched by a 355 nm femtosecond laser pulse onto a mandrel or form tool, or, using imprint lithography, a cloning tool may be used to imprint or emboss the microstructures onto a thin layer of silicone approximately 10-125 μm in thickness.
(49) Diffuser angle refers to how the diffuser 1603 operates upon the incoming light fields. The net effect on the light is a convolution of incoming light distribution and the additional spreading function provided by the diffuser 1603. Diffuser (deg) and resulting illuminance (lux) are shown in Table 3 below (an in
(50) For example, if a collimated beam with <1 deg divergence angle were to strike a 5 deg diffuser 1603, then the net beam distribution would be approximately the root of the sum of the squares of the incoming beam distribution and the diffuser operator 5 deg in this case. For wider beam distributions >60 deg, the effect of diffusion is approximately additive. For example, if the incoming beam distribution were 120 deg, and a 30 deg diffuser 1603 were applied with micro-diffusion structure facing away from the light source, then the net distribution angle after scattering would be approximately 150 deg.
(51) TABLE-US-00003 TABLE 3 Diffuser (deg) Illuminance (lux) 5 50909 30 45479 80 41387
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(53) The light emerging from the LED 1701 passes through an air gap 1710 before diffusion by diffuser 1703, e.g., which may include elliptical micro optical elements (e.g., 1603b and 1603c shown in
(54) As shown with convex light shaping, the light rays incident are focused and emerge through second convex shape element 1707 (e.g., exiting the optical control element) more collimated than before. Higher collimated light 1709 produces higher luminous intensity and throw.
(55) Light throw refers to light which can produce higher illuminance at a 30 m distance than a light with wider distribution angle.
(56) The exiting optical control element 1707 can include prismatic elements, e.g., to disperse light with nonlinear light distribution. Light emerging from lateral LEDs 1701 may be reflected and recycled by means of reflector element 1706, which may be positioned on both the right and left sides of the secondary optic 1707.
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(60) Applications of embodiments in the present disclosure could be applied in numerous applications and industries. For example, as noted above, the present disclosure could be used in automotive grills or other emblems. This would also be advantageous in other transportation industries such as unmanned vehicles, drones, hoverboards, mopeds, bicycles, motorcycles, or other mobile apparatuses. Embodiments of the present disclosure use high-volume micro and mini-LEDs (e.g., 1301, 1601) which can be applied to any surface with microscopic accuracy and such surface can be curved, for example. The diffuser (e.g., 1303, 1603) and optic (1308, 1608) can be similarly curved, depending on application, for an advantageous range of applications for exterior and interior lighting. For example, embodiments of the present disclosure can be provided as part of front and/or rear vehicle lighting modules and controlled for different functions chosen from, but not limited to, brake lights, turn signals, daytime running lights, head lights, tail lights, front and rear fog lights and other lights provided via front and/or rear vehicle lighting modules. Embodiments of the present disclosure can also be used for interior lighting applications such as dashboard indicators, interior lighting (e.g. dome and door lights) and decorative, stylized lighting along contours of vehicle seats, door panels, consoles, and other interior vehicle surfaces.
(61) Similarly, the present disclosure would be advantageous in any device requiring lit branding or safety notifications, protocols or messaging. For example, store fronts, houses, billboards, or any marketing surface can have an improved LED-based lighting assembly in accordance with the technical solutions provided by the example embodiments.
(62) The example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the present disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail, as they will be readily understood by the skilled artisan in view of the disclosure herein.
(63) The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements, assemblies/subassemblies, or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
(64) The terminology used herein is for describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
(65) When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
(66) Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
(67) Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” “top”, “bottom,” and the like, may be used herein for ease of description to describe one element's or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated degrees or at other orientations) and the spatially relative descriptions used herein interpreted accordingly.
(68) The preceding description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present subject matter. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the subject matter. Thus, the present subject matter is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the following claims and the principles and novel features disclosed herein.
(69) While various aspects and embodiments have been disclosed, other aspects and embodiments are contemplated. The various aspects and embodiments disclosed are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.