HIGH EFFICIENCY VEHICLE HEADLAMPS
20220299184 · 2022-09-22
Inventors
Cpc classification
F21S41/645
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21Y2115/30
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S41/143
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S41/37
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S41/635
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S41/151
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S41/16
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S41/663
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S41/176
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F21S41/20
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S41/16
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S41/37
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S41/63
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21S41/64
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A vehicle lamp including a plurality of solid state light emitters that emit light that passes through a cold mirror to be converted to human visible light by a conversion layer. Some converted light will exit the lamp in the desired direction. Some converted light will transmit toward the cold minor be reflected by the cold minor toward the exit of the lamp. A micro-optics layer is optically connected to the solid state light emitters to direct the light therefrom to the cold mirror. Controller is provided to control solid state light emitters and/or the controllable elements of microprism layer.
Claims
1. A vehicle lamp, comprising: a light source including solid state emitters, the solid state emitters are configured to emit light at a portion of a light spectrum; a cold mirror receiving the light emitted from the solid state emitters and passing the light therethrough; a conversion layer receiving the light from the cold mirror, wherein the conversion layer is configured to convert the light from the cold mirror to a visible light, a first portion of the visible light traveling to the cold mirror and being reflected by the cold mirror to exit the vehicle lamp and a second portion of the visible light traveling from the conversion layer out of the vehicle lamp; and a controller to control the solid state emitters.
2. The vehicle lamp of claim 1, wherein the solid state emitters are each individually controllable by the controller.
3. The vehicle lamp of claim 1, wherein the light emitted from the solid state emitters is an ultraviolet light, and wherein the conversion layer is configured to down convert the ultraviolet light to the visible light.
4. The vehicle lamp of claim 3, further comprising a lens intermediate the light source and the cold mirror to control a direction of the light from the solid state emitters.
5. The vehicle lamp of claim 4, wherein the lens includes individual light controlling devices are each individually controllable to control the direction of the light from the light source.
6. The vehicle lamp of claim 4, wherein the controller receives position information of another vehicle and controls the direction of the light by controlling the solid state emitters, the lens, or both to direct the light away from the another vehicle.
7. The vehicle lamp of claim 6, wherein the lens include liquid crystal lenses.
8. The vehicle lamp of claim 1, wherein the solid state emitters are controlled to adjust an amount of lumens being output from the light source and emit the light in a visible portion of the light spectrum.
9. The vehicle lamp of claim 1, wherein the cold mirror includes alternating layers having different indexes of refraction.
10. A vehicle lamp assembly, comprising: a light source including solid state emitters, the solid state emitters are configured to emit electromagnetic radiation; a micro-optic layer optically connected to the light source, wherein each solid state emitter is optically coupled to the micro-optic layer to control a direction of the electromagnetic radiation emitted from the light source; a cold mirror receiving the electromagnetic radiation emitted from the solid state emitters from the micro-optic layer and passing the electromagnetic radiation therethrough; a conversion layer receiving the electromagnetic radiation from the cold mirror, wherein the conversion layer is configured to convert the electromagnetic radiation to a visible light, a first portion of the visible light traveling to the cold mirror and being reflected by the cold mirror to exit the vehicle lamp assembly and a second portion of the visible light traveling from the conversion layer out of the vehicle lamp assembly; and a controller configured to control the solid state emitters.
11. The vehicle lamp assembly of claim 10, wherein the controller is further configured to control the on state of each of the solid state emitters.
12. The vehicle lamp assembly of claim 11, wherein the controller receives sensed signals from vehicle sensors and controls operation of each of the solid state emitters.
13. The vehicle lamp assembly of claim 10, wherein the micro-optic layer is a microprism layer including a plurality of controllable elements to direct an electromagnetic radiation output from the solid state emitters, and wherein the controller is further configured to control a state of the plurality of controllable elements.
14. The vehicle lamp assembly of claim 13, wherein the micro-optic layer includes a plurality of liquid crystal lenses.
15. The vehicle lamp assembly of claim 10, wherein the solid state emitters include an array of vertical-cavity surface-emitting laser elements.
Description
DRAWINGS
[0038] Other advantages of the present disclosure will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
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DETAILED DESCRIPTION
[0058] In general, example embodiments of vehicle lighting, e.g., headlamps, having solid state light sources and integrated beamforming in accordance with the teachings of the present disclosure will now be disclosed. 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.
[0059]
[0060] Circuitry is provided to control operation of the one or more headlamps 101. A light driver 110 controls each of the emitters 104 in the matrix or light source 103, to individually activate or turn on and cause the emitters 104 to emit light. The light driver 110 includes circuitry to process input according to instructions to generate light commands for controlling the matrix 103 of light emitters 104. A lens driver 111 drives each of the plurality of light controlling devices 107 (e.g., microlenses) in the lens 105 to control the direction of the light ray from each emitter 104. The lens driver 111 includes circuitry to process input according to instructions to generate lens commands for controlling the the plurality of light controlling devices 107 in the lens 105. A body control module (BCM) 113 coordinates different operations of the headlamp(s) 101 by sensing the environment and other sensed signals in the vehicle 100.
[0061] The vehicle 100 can include vehicle sensors including a light sensor 115, which can sense the ambient light and light from another vehicle, e.g., reflected light from the headlamps 101 or light emitted by an oncoming vehicle. The light sensor 115 can send light related information in an electrical signal to BCM 113. The BCM 113 is in electrical communication with the light sensor 115 and the light driver 110 and the lens driver 111. The BCM 113 can process the light information signals from the light sensor 115 to control operation of the light emitters 104 and the lens 105, e.g., through control signals to the drivers 110, 111.
[0062] In an example embodiment, the headlamp 101 is ultrathin, e.g., one inch or less or even less than ¼ inch in thickness. The use of solid state layers including the matrix of light emitters 104 and lens 105 allows the headlamp 101 to be ultrathin.
[0063] In an example embodiment, the matrix of light controlling devices 107 (e.g., microlenses) are solid state devices, lenses, prisms, or the like. The light controlling devices 107 are optically coupled to the matrix of light sources 103 to beam form the light 107 emitted from the lamp 101. In an example embodiment, a quantity light controlling devices 107 is a one-to-one match with a quantity of light emitters 104 of the light source 103. In an example embodiment, a quantity of light controlling devices 107 is a one-to-a small number (N) match with a quantity of light emitters 104. The small number N, for example, can be equal to or less than sixteen, equal to or less than eight, equal to or less than four, or equal to or less than two.
[0064]
[0065] A cold mirror 205 is positioned on an emission side of the light source 203 (e.g., the top surface of the VCSEL diode) to receive light 202 emitted from the light source 203. The light 202 can include a significant band of light and light energy outside human perception. The cold mirror 205 is configured to allow certain wavelength bands of light (i.e., a first band of light with a first range of wavelengths) to pass there through, e.g., infrared (“IR”), blue light and the like, and reflects light in other wavelengths (i.e., a second band of light with a second range of wavelengths different than the first range of wavelengths). The cold mirror 205 is an example of a dielectric mirror or dichroic filter, e.g., a Bragg mirror. The cold mirror 205 operates to reflect visible wavelengths of light but transmit longer-wave infrared or shorter-wave ultraviolet radiation. The cold mirror 205 can operate as a dichroic filter to accurately and selectively pass light of a small range of colors (e.g., frequency pass bands) while reflecting other colors (e.g., frequency reflection bands). Dichroic filters can filter light from a white light source to produce light that is perceived by humans to be highly saturated (intense) in color. The cold mirror 205 operates to allow the light 202 to pass from the light source 203 to a converting material layer 207.
[0066] The converting material layer or simply conversion layer 207 receives the light 202 and operates to convert a received light 202 (e.g., the light passed through the cold mirror 205) to a visible wavelength light 212. The light 212 is output to illuminate the environment outside the light assembly 201. The conversion layer 207 can be doped with certain dopants to convert light from a wavelength band to a visible wavelength band. In an example embodiment, the dopant includes quantum dots. Quantum dots can be nanometer size particles whose energy states are dependent on the size of the quantum dot. For example, in semiconductors quantum dots are closely related to the size and shape of the individual semiconductor crystal. Generally, the smaller the size of the crystal, the larger the band gap, the greater the difference in energy between the highest valence band and the lowest conduction band becomes. Therefore, more energy is needed to excite the dot, and concurrently, more energy is released when the crystal returns to its resting state. Quantum dots represent one way to down convert ultraviolet light to a targeted color emission, for example a green light emission or red light emission. The conversion layer 207 does not control the direction of the converted or visible wavelength light 212 and emits some light beams 212A of the visible wavelength light 212 out of the light assembly 201 and some light beams 212B back toward the cold mirror 205. The cold mirror 205 then reflects the light beams 212B outwardly from the light assembly 201 as light beams 212C. The cold mirror 205 is arranged so that visible light 212 from the conversion layer 207 is reflected onto an object in the environment to be illuminated, while infrared radiation or ultraviolet radiation is transmitted through the cold mirror 205 toward the conversion layer 207.
[0067] The lighting system 200 further includes a power source 213 and a light controller 215. The light controller 215 is operably connected to the body control module (BCM) 113 and receives control signals from the BCM that are inputs to controlling the light emitted from the light assembly 201. The light controller 215 can include circuitry (e.g., including a microprocessor) operable connected to a memory that stores instructions for processing inputs and outputting control signals to the light assembly 201 control operation of the light assembly. In an example embodiment, the light source 203 is the only active component and it receives the control signals. The cold mirror 205 and the converting layer 207 can be passive components. The power source 213 can include a vehicle battery and circuitry to condition the power signal to a certain voltage or covert to an AC signal. In an example embodiment, the power source 213 is connected to both the controller 215 and the light source 203 to power both components.
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[0069] The cold mirror 305 can be an all-polymeric cold mirror which reflects visible wavelengths while transmitting a substantial portion of infrared wavelengths or a substantial portion of ultraviolet wavelengths. In an example, embodiment, the cold mirror 305 includes a sufficient number of alternating layers 315, 316, 317 of at least first and second diverse polymeric materials such that at least 50% of peak reflecting visible light of a wavelength of between about 380-680 nm incident on the mirror 305 is reflected. In an example embodiment, at least 50% of infrared light between about 680-2000 nm is transmitted through the cold mirror 305. The cold mirror 305 includes a first skin layer 315, an intermediate structure 316, and a second skin layer 317. The first skin layer 315 faces the light source 303 and may be mechanically fixed to the light source 303. The first skin layer 315 receives the light from the light source 303. The second skin layer 317 is spaced from a remote side 318 of the first skin layer 315 and may receive light passing through the cold mirror 305 or from the light conversion layer 307. The first and second skins 315, 317 support the intermediate structure 316. The intermediate structure 316 may include a plurality of alternating layers 316A, 316B. Specifically, a first intermediate layer 316A of the alternating layers has a first index of refraction. A second intermediate layer 316B of the alternating layers has a second index of refraction, which is different than the first index of refraction, e.g., with a mismatch of at least 0.03. The first and second intermediate layers of the intermediate structure can be polymer layers. The layers 315, 316, 317 of the cold mirror 305 can be the mirrors and can be readily coextruded and can have larger surface areas relative to their thicknesses. The cold mirror 305 can be formed into simple or complex shapes either during extrusion or by post-forming operations such as thermoforming. In addition, they can be laminated to polymeric or nonpolymeric substrates for a variety of vehicle lighting applications.
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[0071] A headlamp lens 426 receives the light 212A, 212C from the cold mirror 205 and converting material layer 207 and further directs the light to output light 212D to the environment. The lens 426 can include various structures to focus and guide light.
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[0074] The lamp 600 further includes a lens 420′ that is optically coupled to an emission side of the matrix 601 (i.e., the side in which light is emitted from). The lens 420′ includes a plurality of individual light refractors or light controlling devices 612. In an example embodiment, the lens 420′ is arranged close or adjacent to the light emitting matrix array 601 such that light that enters each light refactor 612 is from a single one of the light sources 602. The light refractors 612 can be microprisms, microlenses, beam splitters, or the like. The light refactors 612 can include a plurality of microelectromechanical (MEMS) devices systems. The light refractors 612 can be micro-optical devices formed using a LIGA (Lithographie, Galvanoformung, Abformung) process in the body of a base polymer, e.g., polymethyl methacrylate. In an example embodiment, the light refactors 612 are fixed. In an example embodiment, one or more of the light refractors 612 is different (e.g., having a different refractive index and/or formed of different types of optical structures) than other light refractors 612 (neighboring or elsewhere within the lens 420′. A top row 613 of light refractors 612 (adjacent a top 614 of the lens 420′) may have a first or larger refractive index than lower rows of light refractors 612 (closer to a bottom 615 of the lens 420′). Each subsequent row of light refractors 612 in the lens 420′ below the top row 613 can have a second or lower index of refraction that is lower than the first refractive index (e.g., increasingly lower as a function of increasing distance from the top 614). Columns of the light refactors 612 in the lens 420′ can also vary in index of refraction (e.g., vary from a right hand side 616 to a left hand side 617). The lens 420′ can also include a Fresnel lens. In operation, the refractors 612 individually receive light from an associated light emitter 602 at an input side and refract the light to output individual light beams 618 from an output side. Each light beam 618 is individually focused. The individually focused light beams 618 can be directed to the cold mirror 205, 305.
[0075] In an example embodiment, the light refactors 612 are controllable and individually addressable. The light refactors 612 can be liquid crystal lenses (liquid crystals) that can be rotated based on an applied electrical signal or electrical field. A lens controller 620 can control the light refactors 612. In an example, the light refactors 612 can block the light beam 618 for exiting the lens 420′. In an example, the light refactors 612 can redirect the light beam 618 in a controllable manner.
[0076] The plurality of light sources 602 of the array 601 can, for example, be VCSELs in an VCSEL array. In an example embodiment, a VCEL array is selected over an LED array. A VCSEL array can pack light sources 602 more densely than LEDs. For example, about one hundred-fifty lasers can be positioned in a VCSEL array with a footprint of about 2 mm×1 mm. A typical LED footprint for an equivalent number of light sources is 2 mm×2 mm. Also, laser light sources output more coherent light than LEDs. In a non-beam steering matrix light application, an advantage of VCSEL is a smaller size and a single chip. Many LED arrays combine multiple LED chips. The use of lasers as light sources 602 also provides improvement for the dynamic beam steering thru the lens 420′, which can be a liquid crystal on silicon (LCOS) device, which is an example of a spatial light modulator. Such a spatial light modulator is configured to provide spatially varying modulation on a beam of light (e.g., light 606), for example by phase modulating the phase of the light beam, which can perform better with coherent light than with a broader spectrum light source such as light from an LED array. Again, the light controlling devices or refractors 612 can be a reflective liquid crystal or LCOS element that provides spatial light modulation, e.g., amplitude, phase, or polarization of light waves in space and time. A VCSEL array can be a single chip package with hundreds of laser sources on it, and each laser source can be addressed individually to turn on, off or any intensity in between. With LED based matrix lighting array, a board with hundreds of LEDs thereon is required. Also, the laser sources can be lensed thru microlenses that are etched on the chip itself. The LEDs need individual lenses for each LED.
[0077] Thus, the lens 420′ can include the light refractors 612 (e.g., microlenses) to receive a laser beam from one or two light sources 602 and then steer the light 618 and focus the light 618 as needed.
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[0079] The lens 720, being a liquid crystal or crystal steering lens, operates using polarization of the liquid crystals or liquid crystal lenses 721 (e.g., similar to light controlling devices 612 shown in
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[0083] Specifically,
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[0086] The examples described herein refer to an oncoming vehicle 1020 and changing the illuminated area 1015, so as to reduce glare for the oncoming vehicle 1020. However, the present examples are not so limited. The system 1000 could detect any other vehicle on the roadway, either oncoming or traveling in the same direction, and change the illuminated area to reduce glare for the other vehicle.
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[0089] The present disclosure describes the light direction controlling devices or structures as a lens. Such a lens can also include a refractory matrix of optical controlling structures, e.g., prisms, waveguides, shutters, mirrors and the like.
[0090] The foregoing description of the embodiments describes some embodiments with regard to lighting systems for vehicles. These are used for convenience of description. The present disclosure is applicable to solid state lights requiring a controllable lens to steer light rays emitted from the lamp or light sources.
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[0092] Referring back to
[0093] In addition, as discussed above, the light source 203 can include solid state emitters 204, 504, 602 (e.g., a laser of VCSEL array 525). Consequently, the method further includes the step of receiving sensed signals from vehicle sensors 115, 1003, 1421, 1422, 923, 1424, 1425, 1426 in communication with the vehicle lamp 103, 105, 201, 300, 600. Next, 958 adjusting an amount of light output by the each of the solid state emitters 204, 504, 602 based on the sensed signals from the vehicle sensors 115, 1003, 1421, 1422, 923, 1424, 1425, 1426.
[0094] Embodiments of the present disclosure may improve a vehicle headlamp by providing a light, thin device that can be applied to the vehicle. The headlamp can include a matrix of light emitters with each paired to a microlens. The light emitters can be individually controlled. A plurality of the microlenses can be controlled to guide the light rays emitted from the headlamp. For example, some microlenses can alter the direction of the light rays to change the output from an expanded light beam (e.g., a high beam) to a narrowed beam (e.g., a dimmed beam). However, the total output of the emitters is not reduced. That is, the headlamp can continue to output the same lumens. This can hold solid state light emitters in an optimal state, e.g., the driving electrical signal that holds the solid state in its emitting state may be less (voltage and/or current) than the electrical signal to turn the emitter on.
[0095] The light sources and light emitters described herein emit radiation in the electromagnetic spectrum, which is the range of frequencies of electromagnetic radiation and their respective wavelengths and photon energies. In some embodiments, the emitted radiation is in the visible light spectrum, e.g., about a wavelength between 380 nm and 760 nm (400-790 terahertz) which is detectable by the human eye and perceived as visible light. The light sources and emitters can emit other wavelengths, e.g., near infrared (longer than 760 nm) and ultraviolet (shorter than 380 nm), which can be referred to as light. In an example, the light sources and emitters emits a broad spectrum light, e.g., a white light, which is a combination of lights of different wavelengths in the visible spectrum. In an example embodiment, the light sources and emitters as described herein emit electromagnetic radiation ata wavelength greater than ionizing radiation, e.g., near ultraviolet and longer wavelengths.
[0096] 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.
[0097] The terminology used herein is for the purpose of 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.
[0098] 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.
[0099] 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. 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.
[0100] 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 90 degrees or at other orientations) and the spatially relative descriptions used herein interpreted accordingly.