(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY(PCT)
`
`(19) World Intellectual Property Organization
`International Bureau
`
`(43) International Publication Date
`17 January 2002 (17.01.2002)
`
`
`
`PCT
`
`(10) International Publication Number
`WO 02/04247 Al
`
`(74) Agents: FENSTER, Paul et al.; Fenster & Company
`Patent Attorneys, Ltd., P.O. Box 10256, 49002 Petach
`
`(21) International Application Number:=PCT/IL01/00627 Tikva (IL).
`
`(51) International Patent Classification’:
`
`B60Q 1/08
`
`(22) International Filing Date:
`
`9 July 2001 (09.07.2001)
`
`(25) Filing Language:
`
`(26) Publication Language:
`
`(30) Priority Data:
`PCT/IL00/00404
`
`English
`
`English
`
`9 July 2000 (09.07.2000)
`
`IL
`
`(71) Applicant(for ail designated States except US):3DV SYS-
`TEMS,LTD.[ILL]; P.O. BOX 249, 20692 YOKNEAM
`(IL).
`
`(72) Inventors; and
`(75) Inventors/Applicants (for US only): BRAUN, Ori, J.
`LILALL]; 12/7 BOYER STREET, 69127 ‘TEL AVIV (IL).
`YAHAV, Giora [IL/IL]; 11 BEILISS STREET, 34814
`HAIFA(IL).
`
`(81) Designated States (national): AE, AG, AL, AM, AT, AU,
`AZ, BA, BB, BG, BR, BY, BZ, CA, CH, CN, CO, CR, CU,
`CZ, DE, DK, DM, DZ, EC, EE, ES, FI, GB, GD, GE, GH,
`GM,HR, HU,ID,IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC,
`LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW,
`Mx, MZ, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK,
`SL, TJ, TM, TR, TT, TZ, UA, UG, US, UZ, VN, YU, ZA,
`ZW.
`
`(84) Designated States (regional): ARIPO patent (GH, GM,
`KE, LS, MW, MZ, SD, SL, SZ, TZ, UG, ZW), Eurasian
`patent (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), Buropean
`patent (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR,IE,
`IT, LU, MC, NL,PT, SE, TR), OAPI patent (BF, BJ, CF,
`CG, CI, CM, GA, GN, GW, ML, MR,NE,SN, TD, TG).
`
`Published:
`with international search report
`
`[Continued on next page]
`
`(54) Title: METHOD AND APPARATUS FOR PROVIDING ADAPTIVE ILLUMINATION
`
`
`
`(57) Abstract: An illumination system (20, 72, 110, 142) for illuminating a scene comprising: an illuminator (24, 74, 116) having
`a plurality of substantially contiguous independently controllable light (26, 76) providing regions each of which provides light that
`illuminates a different region of the scene; optics (30) that directs light from the illuminator to the scene; a range finder (22, 64, 112)
`that determines distances to regions of the scene; and a controller (28, 29, 118) that controls the plurality of light providing regions
`to provide light for illuminating the scene responsive to distances determined by the range finder (22, 64, 112).
`
`Mercedes EX1009
`U.S. Patent No. 11,208,029
`
`02/04247Al
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`S
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`Mercedes EX1009
`U.S. Patent No. 11,208,029
`
`

`

`WO 02/04247 Ad
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`_IMININNTNIINIUTNTTAUATIMATATMA
`
`For two-letter codes and other abbreviations, refer to the "Guid-
`— before the expiration of the time limit for amending the
`claims and to be republished in the event of receipt of—ance Notes on Codes andAbbreviations" appearing at the begin-
`amendments
`ning ofeach regular issue ofthe PCT Gazette.
`
`

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`WO 02/04247
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`PCT/IL01/00627
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`METHOD AND APPARATUS FOR PROVIDING ADAPTIVE ILLUMINATION
`
`FIELD OF THE INVENTION
`
`The present invention relates to adapting illumination of a scene responsiveto features
`
`and characteristics of the scene and in particular to automatically adapting the illumination to
`
`characteristics and features of the scene.
`
`BACKGROUND OF THE INVENTION
`
`A visual impression of a scene and objects and features in the scene is generally a
`
`function of illumination of the scene. Objects in a scene that are illuminated so that they
`
`contrast strongly with their local background tend to capture our attention. Acuity with which
`
`10
`
`the eye is able to distinguish details of features in a scene and impressions of features of a
`
`scene are generally dependent upon the power spectrum oflight illuminating the features. For
`
`example, color of a woman's dress and her fashion accessories may appear harmonious in one
`
`light and discordant in another light. In addition, cultural convention has coded color with
`
`information that affects our reason and emotions and these cultural conventions affect the way
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`15
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`colors in a scene generate responses to the scene. Red, yellow and green lights not onlytell us
`
`when to stop at traffic lights but also, alert our reason and emotions to various degrees of
`
`danger, or lack thereof.
`It is therefore seen that when illuminating a scenefor a particular desired application,
`
`generally many different variables have to be considered and taken into account. Asa result,
`
`20
`
`achieving effective illumination of a scene is often a relatively complicated, subtle and
`
`arduoustask.
`
`US Patent 5,828,485 describes an illumination device for stage lighting comprising an
`
`image source that acquires an image of an actor on a stage and an array of digital
`
`micromitrors for directing light from a suitable light source to the stage. The array of
`
`25
`
`micromirrors is controlled responsive to the image of the actor to project different shape and
`
`color light beams for illuminating the actor. The illumination device is controllable to follow
`
`the actor as he or she moves on the stage and illuminate the actor accordingly. The patent
`
`notes that characteristics of the projected light beam,e.g. its shape and color can be controlled
`by "image processing software such as Adobe photoshop!M, Kai's power tools!M and the
`
`30
`
`like".
`
`US Patent 4,501,961 describes a range finder having a photosurface for imaging an
`
`object, whose distance from the range finder is to be determined, and an array of LEDsfor
`
`illuminating the object. To prevent parallax, light from the array of LEDsis focussed on the
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`1
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`

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`PCT/IL01/00627
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`object by a samelens that collects light from the object and focuses the collected light on the
`photosurface. A controller controls the array of LEDsto illuminate the object with a pattern of
`
`light which when imaged on the photosurface provides information for determining range to
`
`the object. The range finder comprises a negative lens to adjust the size of the illumination
`
`pattern to the size of the photosurface.
`
`SUMMARYOF THE INVENTION
`
`An aspect of some embodiments of the present invention relates to providing an
`
`illumination system that comprises an illuminator having an array of substantially contiguous,
`
`independently controllable light providing regions and a range finder for determining
`
`10
`
`distances to regions of the scene. Each of the light providing regions, hereinafter referred to as
`
`"luxels", illuminates a different region of the scene. The illumination system comprises a
`
`controller that controls the luxels to provide light responsive to distances determined by the
`
`range finder.
`
`Preferably, the array of luxels in the illuminator is a planar array and the illumination
`
`15
`
`system comprises optics that directs light from the luxels in the array to illuminate the scene.
`
`Optionally, the illuminatoris similar to an illuminator comprising luxels used to provide light
`
`for a 3D range-camera described in PCT/IL00/00404, the disclosure of which is incorporated
`
`herein by reference. The optics has a focal plane, referred to as an “illumination plane",
`
`towards which the optics focuses light from the luxels. Light from each luxel is focused to a
`
`20
`
`different region of the illumination plane. Assuming that
`
`the luxels are substantially
`
`contiguous, the different regions of the illumination plane towards which light from different
`
`luxels is focused are substantially contiguous and non-overlapping. For surfaces of a scene
`
`illuminated by the illumination system that are located relative to the illumination plane
`
`within a depth of field of the optics, the optics focuses light from the luxels to form relatively
`
`25
`
`sharp imagesof the luxels on the surface.
`
`In some embodiments of the present invention, position of the illumination plane
`
`relative to the illumination system is adjustable. In some embodiments of the present
`
`invention, position of the illumination plane is fixed. Optionally the illumination plane is
`
`fixed at
`
`infinity. Optionally,
`
`the illumination plane is located at a distance from the
`
`30
`
`illumination system that is equal to an average of distances to scenes that the illumination
`
`system is intendedto illuminate.
`
`According to an aspect of some embodiments of the present invention, the controller
`
`controls luxels so that intensity of light provided by a luxel is substantially proportional to the
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`2
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`PCT/IL01/00627
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`square of a distance from thearray of luxels to a region of the scene illuminated by the luxel.
`As a result, intensity of light (joules/m2) incident on regions of the scene is substantially
`
`uniform.
`
`Optionally, each luxel can be controlled to provide white light and/or R, G or B light.
`
`In some embodiments of the present invention a luxel can be controlled to provide IR light. In
`
`some embodiments of the present invention the luxels are grouped into groups of four
`
`substantially contiguous luxels. Each luxel in a group of luxels provides a different one of R,
`
`G, B and IR light.
`In some embodiments ofthe present invention, the range finder comprises a 3D range-
`camera such as,
`for example,
`a 3D range-camera described in PCT Application
`
`10
`
`PCT/IL00/0404 referenced above, and in PCT Publications WO 00/36372, WO 00/19705,
`
`WO 01/18563 and US Patents, 6,057,909, 6,091,905 and 6,100,517, the disclosures ofall of
`
`which are incorporated herein by reference. Range-cameras known in the art other than those
`
`described in these documents can be usedin the practice of the present invention.
`
`In 3D range-cameras described in the referenced documents, a train of light pulses is
`
`radiated by a range cameralight source to illuminate the scene. Following each light pulse the
`
`camera is gated opento receivelight reflected from the light pulse by regions in the scene and
`
`image the received light on a photosurface comprised in the camera. Distance to a region is
`
`determined from timing of the gates with respect to emission times of the light pulses and a
`
`20
`
`total amountof light from the region that is received and imaged during the gates on a pixel of
`
`the photosurface that imagesthe region.
`
`In some embodiments ofthe present invention, the array of luxels in the illumination
`
`system functions as the range cameralight source. The illumination system controller controls
`luxels in the array to generate the train of light pulses that illuminates the scene. Optionally,
`
`25
`
`the illumination system comprises a fast shutter, which the controller controls to shutter light
`
`from the array of luxels to generate the train of light pulses. Optionally, luxels controlled to
`
`generatethe train oflight pulses provides infrared (IR) light.
`
`In some embodiments of the present invention the 3D range-camera photosurface is
`
`30
`
`boresighted with the illumination system optics so that a virtual image of the photosurfaceis
`substantially coincident with the illuminator. The illumination system optics, which directs
`light from the luxels to illuminate a scene, therefore also collects light from the scene and
`
`focuses the collected light on the photosurface. For such cases, preferably, the controller gates
`
`the photosurface in synchrony with the fast shutter so that when the fast shutter 1s open to
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`3
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`generate a light pulse the photosurface is gated closed. This prevents halo and back-scatter
`
`from light provided by the luxels from being sensed by pixels in the photosurface and
`
`. interfering with distance measurements. US Application 09/250,322 the disclosure of which is
`
`incorporated herein by reference shows methodsofbore sighting a photosurface with a source
`
`oflight.
`
`In some embodiments of the present invention a region of the illumination plane of the
`
`illumination system that is illuminated by a luxel
`
`is imaged on a single pixel of the
`
`photosurface. In some embodiments of the present invention, a region of the illumination
`
`plane illuminated by a luxel is imaged on a group of contiguouspixels of the photosurface.
`
`10
`
`Optionally, the photosurface is gated by a fast shutter, which may operate, by way of
`
`example,
`
`in a manner described in PCT Publication WO 01/18563. Optionally,
`
`the
`
`photosurface comprises pixels, each of which has a circuit controllable to turn on and turn off
`
`the pixel. The photosurface is gated on and gated off as required by turning on and turning off
`
`the pixels. Photosurfaces comprising pixels having circuits that are controllable to turn on and
`
`15
`
`turn off the pixels are described in PCT publications WO 00/36372 and WO 00/19705,
`
`referenced above.
`
`In some embodiments of the present invention, the illumination system controller
`
`comprises a pattern recognition application that processes images of a scene imaged on the
`
`photosurface to identify features of the scene and objects in the scene. The controller controls
`
`20
`
`the luxels to illuminate the scene responsiveto the identified features and/or objects.
`
`According to an aspect of some embodiments of the present
`
`invention,
`
`the
`
`illumination system determines a velocity of an object in a scene imaged by the illumination
`
`system and the controller controls the luxels responsive to the determined velocity. In some
`
`embodiments of the present invention, the illumination system determines a component of
`
`25
`
`velocity of the object in directions towards or away from the illumination system by
`
`determining distance to the object at a plurality of times. The controller determinesa time rate
`
`of change ofthe distance from the determined distances to determine the component velocity
`
`and then controls the luxels responsive to the determined componentof velocity.
`
`In some embodiments of the present invention, the controller determines a component
`
`30
`
`of velocity of an object using distance of the object from the illumination system and a time
`
`rate of change ofposition of an image of the object in an image of the scene. The component
`
`of velocity determined from motion of the image of the object is substantially perpendicular to
`
`the component of velocity of the object determined from measurements of distance of the
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`object from the illumination system.
`
`In some embodiments of the present invention, the controller of the illumination
`
`system is programmable to provide different desired lighting effects and/or to identify
`
`different types of objects and features of a scene that is illuminated by the illumination
`
`system.
`
`An aspect of some embodiments of the present invention relates to providing a light
`
`bulb comprising an illumination system in accordance with an embodiment of the present
`
`invention. Optionally, the light bulb is suitable for insertion in a conventional light bulb
`
`socket. The light bulb is optionally programmable to identify a particular object and/or feature
`
`10
`
`of its environment and selectively illuminate the object or feature accordingly.
`
`For example, in accordance with an embodiment of the present invention, the light
`
`bulb may be programmedto identify and determine distances to pictures on a wall of a room
`
`in which the light bulb is located. In some embodiments of the present invention, the light
`
`bulb then adjusts illumination that it provides so that intensity oflight illuminating each of the
`
`15
`
`pictures is substantially the same. In some embodiments of the present invention, the light
`
`bulb adjusts color of light that it provides to illuminate each picture responsive to a color
`
`pattern of the picture. Optionally, the bulb first illuminates the picture with white light and
`
`determines color components of the picture from an image of the picture formed on the
`
`photosurface. The light bulb may then illuminate the picture with light that "brings out" the
`
`20
`
`natural colors of the picture.
`
`An aspect of some embodiments of the present invention relates to providing an
`
`automotive headlight for a vehicle. The headlight comprises an illumination system in
`
`accordance with an embodiment of the present invention and provides intelligent adaptive
`
`illumination of a roadway and neighboring regions of the roadway, as seen by a driver of the
`
`25
`
`vehicle. The portion of the roadway and neighboring regions thereofare hereinafter referred to
`
`as a "roadway scene".
`
`According to an aspect of some embodiments of the present invention, a pattern
`
`recognition application comprised in the headlight, or in the illumination system controller or
`
`an associated controller, identifies road signs. Optionally, when a road sign is identified, the
`
`30
`
`controller controls the luxels to adjust hue, saturation and intensity of light illuminating the
`
`road sign so as to "spotlight" the road sign and improveits readability. In some embodiments
`
`of the present invention, the headlight is programmed to spotlight roadway signs that are
`
`farther from the vehicle with greater intensity light than roadwaysigns nearer to the vehicle so
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`that roadway signs at different distances have substantially a same visibility. Alternatively,
`
`identified roadway signs may not be spotlighted until they are within a predetermined range of
`
`the driver's vehicle.
`
`According to an aspect of some embodiments of the present invention, the pattern
`
`recognition application identifies oncoming vehicles and automatically adjusts illumination
`
`provided by the luxels to prevent glare from light provided by the luxels from blinding a
`
`driver of the oncoming vehicle.
`
`According to an aspect of some embodiments of the present invention, the headlight
`
`determines a closing speed of the vehicle to objects in the roadway scene and controls light
`
`10
`
`from the luxels that illuminates the objects responsive to the determined closing speed. For
`
`example, the headlight can determine if the vehicle is closing too quickly on a preceding
`
`vehicle in front of the driver's vehicle. Optionally,
`
`the headlight alerts the driver to a
`
`dangerous closing speed by illuminating the preceding vehicle with a suitable spatial and/or
`
`temporal illumination pattern e.g. by illuminating the back of the preceding vehicle with
`
`15
`
`intense flashing red light.
`
`Whereas, the light bulb and headlight in accordance with an embodiment of the
`
`present invention are described as having range measuring capability, in some embodiments
`
`of the present invention, a light bulb or headlight in accordance with an embodimentof the
`
`present invention does not have a ranging capability. The bulb or headlight preferably
`
`20
`
`comprises a photosurface on which an imageof a scene illuminated by the bulb or headlightis
`
`imaged. The bulb or headlight optionally provides substantially all the functions that the bulb
`
`or headlight described above provides except for those functions dependent upon range
`
`measurements.
`
`It is noted that whereas the headlight and bulb as described above are shown as
`
`25
`
`monolithically integrated structures, a head light or bulb, in accordance with embodiments of
`
`the present
`
`invention can have distributed components. For example, a headlight,
`
`in
`
`accordance with an embodiment of the present
`
`invention may have its
`
`illuminator
`
`conventionally at the front of the fender, its range-camera in the grillwork and its controller
`
`under the dashboard. Similarly a bulb, in accordance with an embodiment of the present
`
`30
`
`mounted in a chandelier may have a controller located in a wall unit, its illuminator in a
`
`conventional socket of the chandelier and its 3D-range camera mounted in the chandelier
`
`structure.
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`There is therefore provided in accordance with an embodiment of the present
`
`invention, an illumination system for illuminating a scene comprising: an illuminator having a
`
`plurality of substantially contiguous independently controllable light providing regions each
`
`of which provideslight that illuminates a different region of the scene; optics that directs light
`
`from the illuminator to the scene; a range finder that determines distances to regions of the
`
`scene; and a controller that controlsthe plurality of light providing regions to providelight for
`
`illuminating the scene responsive to distances determined by the range finder.
`
`Optionally, the range finder comprises a 3D range-camera, the 3D range-camera
`
`comprising a gated photosurface having pixels and collecting optics that collects light from
`
`10
`
`the scene and imagesthe collected light on the photosurface.
`
`Optionally, there is a one to one correspondence between light providing regions and
`
`pixels of the photosurface and light from a region of the scene illuminated with light from
`
`substantially only one light providing region is imaged substantially only on the pixel
`
`cotrespondingto the light providing region.
`
`15
`
`Alternatively,
`
`there is optionally a one to many correspondence between light
`
`providing regions and pixels so that each light providing region corresponds to a group of
`
`contiguous pixels and wherein light from a region of the scene illuminated by a light
`
`providing region is imaged substantially only on the light providing region's corresponding
`
`group of pixels.
`Alternatively,
`
`20
`
`there is optionally a many to one correspondence between light
`
`providing regions and pixels so that each pixel corresponds to a group of contiguous light
`
`providing regions and wherein light from a region of the scene illuminated by light from a
`
`group of light providing regions is imaged substantially only on the group's corresponding
`
`pixel.
`
`25
`
`In some embodiments of the present invention, the collecting optics of the 3D range-
`
`camerais the optics that directs light to the scene. Optionally, the photosurface is boresighted
`
`with the optics that directs light to the scenes so that a virtual image of the photosurface is
`
`substantially coincident with the illuminator.
`
`In some embodiments of the present invention, the illumination system and comprises
`
`30
`
`a shutter controllable to shutter light from the illuminator. Optionally, the controller controls
`
`the shutter to shutter light from the illuminator so as to provide a train of light pulses that
`
`illuminates the scene.
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`In some embodiments of the present invention, the controller turns on and turns off
`
`light providing regions of the plurality of light providing regions to provide a train of light
`
`pulses that illuminates the scene.
`
`In some embodiments of the present invention, the illuminator provides IR light and
`
`the train of light pulses comprises IR light pulses.
`
`In some embodiments of the present invention, the controller gates the photosurface
`
`on for at least one gate period at a time following a time at which each light pulse in the light
`
`pulse train is provided. Optionally, the controller determines a distance to a region of the
`
`scene using an amountoflight incident on a pixel of the photosurface that images the region
`
`10
`
`during the at least one gate following each light pulse in thelight pulsetrain.
`
`In some embodiments of the present invention, the controller comprises a pattern
`
`recognition application which the controller uses to identify features and/or objects in images
`
`of the scene formed on the photosurface. Optionally,
`the controller controls the light
`providing regions to provide light that illuminates the scene responsive to one or both of
`
`features and objects that it identifies in the image. Alternatively or additionally, the controller
`
`controls the 3D range-camera to acquire a first image of the scene ata first time and a second
`
`image of the scene at a second time and identifies a feature of the scenethat has a location in
`
`the second image different from its location in the first image. Optionally, the controller uses
`
`the difference in location of the feature, a difference between the first and second times, and
`
`20
`
`distance of the feature from the illumination system to determine a transverse component of
`
`velocity of the feature in a direction substantially perpendicular to a direction along which the
`illumination system illuminates the feature. Optionally,
`the controller controls the light
`
`providing regions to provide light that illuminates the scene responsive to the transverse
`
`componentof velocity.
`
`25
`
`In some embodiments of the present invention, the controller controls the range finder
`
`to determine distances to a region of the scene at a first time and a second time and uses a
`
`difference in the distances and a difference between thefirst and second times to determine a
`
`radial component of velocity of the region along a direction substantially parallel to a
`
`direction along which the illumination system illuminates the region. Optionally,
`
`the
`
`30
`
`controller controls the light providing regions to provide light that illuminates the scene
`
`responsive to the radial componentof velocity.
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`
`In some embodiments of the present
`
`invention,
`
`the controller controls the light
`
`providing regions to illuminate only regions of the scene that are located within a desired
`
`range of distances from the illumination system.
`
`In some embodiments ofthe present invention, the controller controls intensity oflight
`
`provided by light providing regions responsive to distances determined by the range finder.
`
`In some embodiments of the present
`
`invention,
`
`the controller controls the light
`
`providing regions so that relative intensity of light provided by the illuminator that illuminates
`
`two different regions of the scene is substantially proportionalto a ratio of the squares oftheir
`
`respective distances from the illumination system.
`
`10
`
`In some embodimentsofthe present invention, the optics that directs light to the scene
`
`focuses light from the illuminator to a plane whose distance relative to the illumination
`
`system is adjustable. Optionally,
`
`the controller controls distance of the plane from the
`
`illumination system responsive to distance measurements to region of the scene.
`In some embodimentsof the present invention, the optics that directs light to the scene
`
`15
`
`focuses light from the illuminator to a plane whose distance relative to the illumination
`
`system is fixed. Optionally, the position of the plane is located at infinity. Alternatively, the
`
`position of the plane is located at a distance from the illumination system that is an average of
`
`distances to scenes that the illumination system is intended to illuminate.
`
`In some embodiments of the present invention, each light providing region provides
`
`20
`
`whitelight.
`
`In some embodiments of the present
`
`invention, each light providing region is
`
`controllable to provide R, G and B light in controllable amounts.
`
`In some embodiments of the present invention, each light providing region provides
`
`TR light.
`
`25
`
`In some embodiments of the present invention, the illuminator provides R, G, B and
`
`IR light and each light providing region provides one of R, G, B or IR light. Optionally, the
`
`light providing regions are grouped in groups of four and wherein each one ofthe light
`
`providing region in a group provides a different one ofR, G, B and IR light.
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`In some embodimentsof the present invention, the controller controls intensity of R, G
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`or B light provided by each light providing region so as to control hue, saturation or intensity
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`of light illuminating a region of the scene which is illuminated by light from the light
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`providing region independently of hue saturation and intensity of light illuminating other
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`regions of the scene. Optionally,
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`the photosurface is color sensitive and the controller
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`processes an image of the scene to determine color components of the scene. Optionally, the
`controller controls intensity ofR, G or B light provided by each light providing region 50 as to
`control hue, saturation or intensity oflight illuminating the scene responsive to the determined
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`color components.
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`In some embodiments of the present invention, the controller controls the 3D range-
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`camera to repeatedly acquire an image of the scene and determine distances to regions of the
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`scene at a frequency equal to or greater than 25 Hz.
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`Optionally, following the acquisition of each image,
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`the controller adjusts light
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`provided by the light providing regions to match changes in the positions of one or both of
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`features and objects in the scene relative to their positions in an immediately preceding image
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`of the scene.
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`Optionally, a time lapse between acquisition of the image and a time at which the
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`illuminator provides light adjusted responsive to the imageis sufficiently short so that during
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`the time lapse the positions of features and/or objects of the scene do not change sufficiently
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`to generate a substantial mismatch between the illumination and the scene. Optionally,
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`wherein the time lapse is less than about 50 milliseconds. Alternatively, the time lapse is
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`optionally less than about 25 milliseconds.
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`In some embodiments of the present invention, the controller is programmable to
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`control the light providing regions to provide desired illumination effects.
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`There is further provided, in accordance with an embodimentof the present invention,
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`an automotive light for use in a vehicleforilluminating a roadway scene comprising a portion
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`of a road on which the vehicle is located and neighboring regions thereof, the automotive light
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`comprising an illumination system,
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`in accordance with an embodiment of the present
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`invention.
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`In some embodiments of the present invention, the controller controls the illumination
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`system to determine distances to objects in the roadway scene at different times and uses a
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`change in distance of an object as a function of time to determine if the vehicle and object are
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`closing at a dangerous speed. Optionally, if the controller determines that the vehicle and
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`object are closing at a dangerous speed the controller controls the illumination system to
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`generate an optical cue that alerts the driver to the danger. Optionally, the optical cue
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`comprises a spatial
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`light pattern that
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`the illumination system projects on the object.
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`Optionally, the optical cue comprises a spatial light pattern that the illumination system
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`projects on the road.
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`In some embodiments of the present
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`invention,
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`the light providing regions are
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`controllable to provide different color light and wherein the optical cue is formed with colored
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`light. In some embodiments of the present invention, the optical cue is time dependent.
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`In some embodiments of the present invention, the controller processes images of the
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`roadway scene provided by the photosurface to identify road signs in the roadway scene.
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`Optionally, when a roadway sign is identified, the controller controls the light providing
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`regions to direct a beam of light that illuminates the roadwaysign.
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`Optionally, the controller controls the light providing regions so that intensity of light
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`they provide to illuminate signs farther from the vehicle is greater than intensity oflight they
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`provideto illuminate signs closer to the vehicle. Optionally, intensity of light provided by the
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`light providing regionsto illuminate a road sign is substantially proportional to the square of a
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`distance of the sign from the vehicle.
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`In some embodiments of the present invention, the photosensor is sensitive to color
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`and the light providing regions are controllable to provide different color light and wherein
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`the controller process an image of the sign to determine its color components and controls hue
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`and saturation of light that illuminates the sign to enhance its readability.
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`In some embodiments of the present
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`invention,
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`the controller controls the light
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`providing regionsto radiate a train oflight pulses and following each light pulse the controller
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`gates on the photosurface for a short gate timed with respect to a time at which the light pulse
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`is radiated and having a gate width so that light received by the photosurface during the gate is
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`substantially only light reflected from matter in the air in a small volumeof space located a
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`short distance immediately in front of the illumination system and wherein the controller uses
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`an amount oflight received by the photosurface during the gates to determinevisibility of the
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`atmosphere.
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`Optionally, the controller adjusts illumination provided by the illumination system
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`responsive to the determined visibility. Alternatively or additionally, light providing regions
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`of the illuminator are controllable to provide visible light at different wavelengths and the
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`controller determinesvisibility as a function of wavelength. Optionally, the