Patent ID: 12234962

DETAILED DESCRIPTION

A system such as a vehicle or other system may have components that emit light such as headlights and other lights. Headlights may be used to illuminate roadways and other objects in the vicinity of a vehicle. The illumination provided by the headlights allows vehicle occupants to view the objects at night or in other dim ambient lighting conditions and facilitates the operation of sensors. For example, headlight illumination at visible and/or infrared wavelengths may be used to provide illumination for image sensors that are used by an autonomous driving system or driver's assistance system.

The illumination that is emitted by the headlights may be adjusted. For example, the headlights may have adjustable lens arrays and other adjustable components that allow the pattern of illumination emitted by the headlights to be adjusted. Headlights may, as an example, be adjusted to narrow or widen headlight beams and/or to otherwise adjust the shape of the headlight illumination pattern. If desired, the color of emitted light may be varied. Headlight beam adjustments may be used to switch the headlights between operation in high-beam and low-beam modes, to steer headlight beams to the left and right (e.g., to accommodate curves in a road), to spotlight objects of interest, to enhance headlight performance under particular weather conditions or other operating conditions, to provide alerts to pedestrians or others, and/or to otherwise vary the properties of the headlight output.

FIG.1is a side view of a portion of an illustrative vehicle. In the example ofFIG.1, vehicle10is the type of vehicle that may carry passengers (e.g., an automobile, truck, or other automotive vehicle). Configurations in which vehicle10is a robot (e.g., an autonomous robot) or other vehicle that does not carry human passengers may also be used. Vehicles such as automobiles may sometimes be described herein as an example. As shown inFIG.1, vehicle10may be operated on roads such as roadway14. Objects such as object26may be located on or near other structures in the vicinity of vehicle10such as roadway14.

Vehicle10may be manually driven (e.g., by a human driver), may be operated via remote control, and/or may be autonomously operated (e.g., by an autonomous driving system or other autonomous propulsion system). Using vehicle sensors such as lidar, radar, visible and/or infrared cameras (e.g., two-dimensional and/or three-dimensional cameras), proximity (distance) sensors, and/or other sensors, an autonomous driving system and/or driver-assistance system in vehicle10may perform automatic braking, steering, and/or other operations to help avoid pedestrians, inanimate objects, and/or other external structures such as illustrative obstacle26on roadway14.

Vehicle10may include a body such as vehicle body12. Body12may include vehicle structures such as body panels formed from metal and/or other materials, may include doors18, a hood, a trunk, fenders, a chassis to which wheels are mounted, a roof, etc. Windows may be formed in doors18and other portions of vehicle body12(e.g., on the sides of vehicle body12, on the roof of vehicle10, and/or in other portions of vehicle10). Windows, doors18, and other portions of body12may separate the interior of vehicle10from the exterior environment that is surrounding vehicle10. Doors18may be opened and closed to allow people to enter and exit vehicle10. Seats and other structures may be formed in the interior of vehicle body12.

Vehicle10may have automotive lighting such as one or more headlights (sometimes referred to as headlamps), driving lights, fog lights, daytime running lights, turn signals, brake lights, and/or other lights. As shown inFIG.1, for example, vehicle10may have lights such as lights16. In general, lights16may be mounted on front F of vehicle10, on an opposing rear portion of vehicle10, on the left and/or right sides of vehicle10, and/or on other portions of body12. In an illustrative configuration, which may sometimes be described herein as an example, lights16are headlights and are mounted to front F of body12. There may be, as an example, left and right headlights16located respectively on the left and right of vehicle10to provide illumination20in the forward direction (e.g., in the +X direction in which vehicle10moves when driven forward in the example ofFIG.1). By shining headlights16on external surfaces28such as roadway14and object26in front of vehicle10, occupants of vehicle10may view surfaces28even in dim ambient lighting conditions (e.g., at night or in other low-light situations due to weather, tunnels, time of day, etc.). The operation of sensors in vehicle10such as image sensors and other sensors that use light may also be supported by providing surfaces28with illumination.

If desired, headlights or other vehicle lights may be used to assist a user of vehicle10who is approaching vehicle10and/or may be used to communicate with pedestrians or others nearby. As an example, headlights or other vehicle lights may be used to light up the area around vehicle10with illumination20whenever sensors in vehicle10detect that a user is approaching vehicle10. In this way, a user may be able to better view obstacles near the vehicle and can walk around such obstacles. As another example, pedestrians may be waiting to cross in front of vehicle10after vehicle10has come to a stop at a crosswalk. To help inform the pedestrians that it is safe to cross, vehicle10may adjust headlights or other vehicle lights to illuminate the crosswalk. A given color of light (e.g., green light for safe crossing conditions or a red light otherwise), a particular pattern of light (e.g., an arrow orientated along the crosswalk or a stop sign), time-varying light characteristics (e.g., slow flashing at 1 Hz, a chasing light pattern, etc.), and/or any other suitable aspect of illumination20may be used to inform the pedestrians when it is safe to cross the street and/or to otherwise provide information to people in the vicinity of vehicle10.

Vehicle10may have components24. Components24may include propulsion and steering systems (e.g., manually adjustable driving systems and/or autonomous driving systems having wheels coupled to body12, steering controls, one or more motors for driving the wheels, etc.), and other vehicle systems. Components24may include control circuitry and input-output devices. Control circuitry in components24may be configured to run an autonomous driving application, a navigation application (e.g., an application for displaying maps on a display), and software for controlling vehicle climate control devices, lighting, media playback, window movement, door operations, sensor operations, and/or other vehicle operations. For example, the control system may form part of an autonomous driving system that drives vehicle10on roadways such as roadway14autonomously using data such as sensor data. The control circuitry may include processing circuitry and storage and may be configured to perform operations in vehicle10using hardware (e.g., dedicated hardware or circuitry), firmware and/or software. Software code for performing operations in vehicle10and other data is stored on non-transitory computer readable storage media (e.g., tangible computer readable storage media) in the control circuitry. The software code may sometimes be referred to as software, data, program instructions, computer instructions, instructions, or code. The non-transitory computer readable storage media may include non-volatile memory such as non-volatile random-access memory, one or more hard drives (e.g., magnetic drives or solid-state drives), one or more removable flash drives or other removable media, or other storage. Software stored on the non-transitory computer readable storage media may be executed on the processing circuitry of components24. The processing circuitry may include application-specific integrated circuits with processing circuitry, one or more microprocessors, a central processing unit (CPU) or other processing circuitry.

The input-output devices of components24may include displays, light-emitting diodes and other light-emitting devices, haptic devices, speakers, and/or other devices for providing output. Output devices in components24may, for example, be used to provide vehicle occupants and others with haptic output, audio output, visual output (e.g., displayed content, light, etc.), and/or other suitable output. The input-output devices of components24may also include input devices such as buttons, sensors, and other devices for gathering user input, for gathering environmental measurements, for gathering information on vehicle operations, and/or for gathering other information. The sensors in components24may include ambient light sensors, touch sensors, force sensors, proximity sensors, optical sensors such as cameras operating at visible, infrared, and/or ultraviolet wavelengths (e.g., fisheye cameras, two-dimensional cameras, three-dimensional cameras, and/or other cameras), capacitive sensors, resistive sensors, ultrasonic sensors (e.g., ultrasonic distance sensors), microphones, radio-frequency sensors such as radar sensors, lidar (light detection and ranging) sensors, door open/close sensors, seat pressure sensors and other vehicle occupant sensors, window sensors, position sensors for monitoring location, orientation, and movement, speedometers, satellite positioning system sensors, and/or other sensors.

During operation, the control circuitry of components24may gather information from sensors and/or other input-output devices such as lidar data, camera data (e.g., two-dimensional images), radar data, and/or other sensor data. This information may be used by an autonomous driving system and/or driver's assistance system in vehicle10. This information may also be used in determining the shape of roadway14, the location of objects such as objects26and/or other characteristics of surfaces28. Based on these measurements, user input, or other information, vehicle10may adjust headlights16. For example, beam shape may be adjusted when oncoming headlights are detected, beam direction may be adjusted to accommodate detected curves in roadway14, beam shape may be adjusted to help enhance visibility in rain or other weather conditions, beam shape may be adjusted to spotlight detected objects such as object26, suitable patterns and/or colors of illumination may be output when it is desired to use headlights16and/or other vehicle lighting to provide output to nearby pedestrians or others, output light may be adjusted to provide illumination near vehicle10as a user walks towards vehicle10at night, etc.

A vehicle occupant or other user of vehicle10may provide user input to the control circuitry of vehicle10. Cameras, touch sensors, physical controls, and other input devices may be used to gather the user input. Using wireless communications with vehicle10, remote data sources may provide the control circuitry of components24with database information. If desired, headlights16and/or other vehicle lighting may be adjusted based on user input and/or information from a remote data source. For example, information on road conditions (e.g., road size, road type, road shape, road surface, etc.) may be stored in a remote database and this information may be provided to vehicle10over a wireless communications link. During operation, vehicle10may adjust headlights16based on the road condition information.

Headlights16may have two-dimensional arrays of components. Headlights16may, for example, have arrays of light-emitting diodes and/or other light sources and corresponding arrays of lenses (sometimes referred to as microlens arrays or lens arrays) that control the directions in which light is emitted from the headlights. Headlights16may also have light modulator arrays (e.g., arrays of individually adjustable light modulator elements that adjust the amount of light passing through corresponding lenses). If desired, lens elements may be formed from liquid crystal material and/or other material having optical properties (e.g., electrically adjustable refractive index values) that can be adjusted to change lens element focal lengths and/or other lens element optical characteristics.

The arrays of components in headlights16may be arranged to form two-dimensional arrays with rows and columns or may be arranged with other two-dimensional layouts. Array components such as lenses and/or light modulator elements may have rectangular outlines or other suitable shapes (e.g., hexagonal footprints, etc.). In an illustrative configuration, which may sometimes be described herein as an example, lens and light modulator elements have rectangular shapes and are arranged in rows and columns in a two-dimensional array (e.g., an N×M array, where the values of N and/or M are at least 2, at least 5, at least 10, less than 50, less than 20, less than 15, and/or less than 10).

FIG.2is a cross-sectional side view of an illustrative headlight for vehicle10. Headlight16ofFIG.2may be mounted to body12. Body12may have a cavity that receives headlight16, headlight16may be attached to an outer surface of body12, and/or headlight16may be otherwise supported by body12. As shown inFIG.2, headlight16may include headlight housing30. Light may be produced by light source32. Light source32may have multiple light-emitting devices34such as light-emitting diodes, lasers, lamps, etc. Light-emitting devices34may, as an example, be light-emitting diodes such as white light-emitting diodes. If desired, light-emitting devices34may include infrared light-emitting diodes that are configured to emit infrared light, may include colored light-emitting diodes (e.g., red, yellow, blue, and/or green light-emitting diodes), and/or may include other light-emitting components. In arrangements in which source32includes devices34of different colors, light color may be adjusted by selectively activating and deactivating devices34.

Light source32may emit light that travels in the +X direction ofFIG.2in the interior of housing30. Headlight16may include a light concentrating component such as light collimator36that helps collimate the light emitted by light source32. Light collimator36may be formed from one or more optical components such as illustrative collimating lens40and/or a reflective structure that helps concentrate light from light source32such as conical mirror38. Light from light source32that has been partly or fully collimated by light collimator36passes through adjustable lens array42before being emitted as headlight illumination20(e.g., a headlight beam that can produce illumination on surfaces28).

FIG.3is a cross-sectional side view of an illustrative adjustable lens array for headlight16. As shown inFIG.3, adjustable lens array42may have one or more arrays of lens elements such as lens array50and lens array58. The lenses of arrays50and58may be organized in rows and columns or other suitable patterns (e.g., columns extending parallel to the Z axis and rows extending parallel to the Y axis in the example ofFIG.3). Each lens of array50may be aligned with a respective lens of array58.

An array of light modulator elements such as light modulator array54may be interposed between lens array50and lens array58. Array54may be separated from lens arrays50and58by air gaps or gaps52and/or56between light modulator array54and array50and/or array58may be filled with clear polymer or other transparent material. Light modulator array54may have an array of electrically adjustable light modulators elements54E, which may be individually controlled (e.g., elements54E may be arranged in a two-dimensional array having columns parallel to the Z axis ofFIG.3and having rows parallel to the Y axis ofFIG.3). By adjusting the amount of light passing through each light modulator element54E, the pattern of light passing through lens array42can be controlled to adjust the headlight beam pattern emitted by headlight16.

If desired, array54may be provided with a masking grid. For example, each element54E may have a light modulator cell62E covered by a portion of an opaque mask64. Mask64may be configured so that there is a mask opening60that is aligned with the center of each light modulator cell62E. Mask64may help block stray light and thereby reduce or eliminate light rays passing through structures at the boundaries between adjacent cells62E and may therefore help ensure that the light passing through each light modulator element54E is passing through a desired active area of that element. Masks such as mask64may be provided on the entrance face and/or exit face of array54and/or may otherwise be incorporated into array54.

Vehicle10may use sensor input, user input, or other information in determining how to adjust array42. Consider, as an example, the arrangement ofFIG.4. As shown inFIG.4, headlight16may illuminate surfaces28in front of vehicle10, such as the surface of object26and/or the surface of roadway14. During operation of vehicle10(e.g., while vehicle10is being driven along roadway14), vehicle10may determine that the output of headlight16should be provided in a high-beam mode and may therefore adjust array42to produce illumination in high-beam pattern80. In other conditions such as when oncoming headlights are detected or rain is sensed, vehicle10may determine that the output of headlight16should be provide in a low-beam mode and may therefore adjust array42to produce illumination in low-beam pattern82. In other situations, the beam output by headlight16may be adjusted to have a pattern such as illustrative pattern84, illustrative pattern88, and/or any other suitable pattern that illuminates a desired portion or portions (e.g., discontinuous portions) of the surface in the vicinity of vehicle10. Patterns such as these may assist a user in viewing objects of interest (e.g., by highlighting the object with spot illumination) and may be used in assisting the user in difficult lighting conditions (e.g., illumination attributes may be adjusted to enhance roadway and obstacle visibility by angling illumination20downwardly, by adjusting the color of illumination20, and by increasing the intensity of illumination20during inclement weather where beam direction, intensity, color, and/or other factors tend to reduce visibility). If desired, headlights16may be adjusted to provide pedestrians and others in the vicinity of vehicle10with information on vehicle status, planned vehicle operations, and/or other vehicle attributes. As an example, illumination20may be red and flashing and may be provided in pattern84or80to inform people near vehicle10that vehicle10is moving or is about to move. In general, the illumination from headlight16may be controlled to have any suitable shape (circular, oval, rectangular, etc.) and may be steered up/down and/or left/right. If desired, the pattern of light that is emitted may convey information to nearby observers. For example, a particular type of illumination (e.g., vertical or horizontal stripes, spots, icon shapes, and/or other patterns of illumination, illumination of a given color, and/or illumination characterized by a given time-varying intensity) may serve as an indicator that vehicle10is about to turn, slow down, stop, or accelerate, may serve as an indicator that a pedestrian or other person has been recognized by vehicle10, may serve as an indicator that vehicle10is driving autonomously or manually, and/or may serve as an indicator that other conditions are present, etc.

FIGS.5,6, and7are cross-sectional side views of illustrative light modulator arrays for adjustable lens array42.

In the example ofFIG.5, light modulator array54has an array of individually adjustable light modulator elements54E based on guest-host liquid crystal modulator devices. Array54may, as an example, have first and second transparent substrates90with respective sets of transparent light modulator electrodes92(e.g., electrodes formed from transparent conductive material such as indium tin oxide, etc.). Each element54E in the example ofFIG.5has first and second respective electrodes. If desired, a shared ground electrode may span multiple elements54E. The arrangements ofFIGS.5,6, and7where a pair of element-specific electrodes is used for each element54E are illustrative.

As shown inFIG.5, guest-host liquid crystal layer94may be interposed between substrates90. By supplying a desired (and potentially different) voltage to the electrodes92of each element54E, the magnitude of the electric field across guest-host liquid crystal layer94may be adjusted as a function of position within array54(e.g., the amount of light transmission may be independently varied as desired for each light modulator element54E). Each element54E may, as an example, be placed in an opaque state, a transparent state, or one or more intermediate transmission states in which the element is characterized by an intermediate amount of light transmission between the opaque and transparent state levels. By adjusting each of the light modulator elements54E in array54in this way, the amount of light output from each element54E may be adjusted so that the pattern of light emitted by headlight16is controlled as described in connection with the examples ofFIG.4.

In one illustrative configuration, guest-host liquid crystal layer94has black absorbing dyes so that elements54E exhibit neutral transmission. Elements54E may, for example, appear clear, gray, or black, allowing headlight illumination20to appear neutral in color with no color cast when light source32emits white light illumination. The transmission dynamic range of array54may, as an example, be1:20and array54may have a response time on the order of milliseconds.

In other illustrative configurations, there are multiple guest-host liquid crystal layers and associated substrates in array54. For example, multiple guest-host liquid crystal light modulator structures may be stacked on top of each other to form array54. Each guest-host liquid crystal light modulator layer in this type of stacked configuration may have a dichroic dye or other guest material that is configured to pass light of a different color. For example, a first layer may have an array of red guest-host liquid crystal light modulator elements that pass a selected amount of red light, a second layer may have an array of green guest-host liquid crystal light modulator elements that pass a selected amount of green light, and a third layer may have an array of blue guest-host liquid crystal light modulator elements that pass a selected amount of blue light.

During operation, white light illumination from light source32that has passed through light collimator36may be supplied to this stacked structure. A masking layer with an array of openings such as mask64ofFIG.3may be associated with each stacked structure (layer). The openings in each mask and the layout of the elements54E in each corresponding layer of the stacked structure may be configured to avoid interference between layers. As an example, the green and blue layers may have openings that permit red light from the red layer to pass after this light has been adjusted in intensity by the red-light modulator elements and the red layer may have openings that permit white light to reach the green and blue light modulator elements in their respective layers.

Depending on the settings of the red, green, and blue light modulator elements in the stack of array54, desired patterns of red, green, and blue light may be emitted from headlight16. The red, green, and blue light may merge when projected onto surface28, so that the relative intensity contributed by each color will influence the resulting color of the headlight illumination. By mixing the emitted red, green, and blue light, different non-neutral colors of headlight beams may be created and/or different portions of headlight beams may be provided with different colors. Colored light may also be mixed where there is overlap between the output of different array elements, thereby forming mixed-color areas and/or white light areas.

If desired, light source32may have multiple light-emitting devices34of different colors. Light source32may include, for example, red, green, and blue light-emitting diodes or other non-neutrally colored light-emitting devices. In this type of arrangement, a single layer of light modulator elements54E may be used to provide colored output for headlight16. Red light, green light, and blue light may be provided in a series of discrete pulse (e.g., pulses of less than 1/60 s or other short time period to avoid visible flicker effects). Light modulator array54may be configured to pass a first pattern of light when the red-light source is active, a second pattern of light when the green light is active, and a third pattern of light when the blue light is active. In this way, headlight beams with desired patterns and colors may be created. As an example, if red light output is desired, the blue and green light sources may be turned off and if white light output is desired, the red, blue, and green sources may all be activated. These types of arrangements and/or other arrangements may be used for providing headlight16with the ability to produce colored light illumination regardless of the type of light modulator elements54E that are used. If desired, light source32may include one or more infrared light-emitting devices34. This allows desired patterns of infrared light to be emitted (e.g., the light-modulator elements of array54may be used to modify the pattern of emitted infrared light in addition to modifying the patterns of emitted red, blue, and green light).

Color may be imparted to white light passing through array54using colored dyes in guest-host liquid crystal layers or may be provided using other color filter arrangements. For example, in light modulator arrays based on liquid crystal light modulators or electrochromic modulators, color filter structures such as bandpass thin-film interference filters and/or colored ink structures may be used to impart red, green, and blue colors to different layers of modulator elements.

In the example ofFIG.6, light modulator array54has an array of light modulator elements54E based on liquid crystal modulator cells. Substrates90ofFIG.6are sandwiched between polarizers95. Electrodes92may be formed on substrates90. Liquid crystal layer96may be interposed between substrates90and between electrodes92. The voltage applied to the pair of electrodes92in each element54E controls the amount of electric field applied across the portion of liquid crystal layer96associated with that elements54E. In turn, the amount of electric field in the liquid crystal layer of each element54E controls the amount of liquid crystal molecule rotation in that element, the corresponding amount of light polarization rotation exhibited by that element, and therefore the amount of light transmission through that element. The transmission dynamic range in this type of light modulator array may be, as an example, 1:200. Response times may be on the order of milliseconds or faster. If desired, two or more liquid crystal light modulator structures (e.g., two or more liquid crystal layers96and associated substrates90, polarizers95, and electrodes92) may be stacked on top of each other as descried in connection with the illustrative stacked modulator arrangement ofFIG.5. Each stacked structure may have a respective mask64or a single mask may be shared among layers in the stack.

An illustrative electrochromic light modulator array is shown inFIG.7. Electrochromic light modulator array54ofFIG.7has an array of electrochromic light modulator elements54E. Array54has a layer of electrochromic structures98between substrates90. Electrodes92associated with each of elements54E may be individually supplied with desired voltages to adjust the movement of ions in structures98. The movement of the ions in each element54E adjusts the light transmission through that element. The response time of this type of modulator may be about 1 s to several minutes, depending on operating temperature. If desired, two or more electrochromic modulator layers (and associated masks64) may be stacked to form electrochromic light modulator array54.

In lens array arrangements of the type shown inFIG.3, each of the lens elements in input lens array50focuses collimated light so that the focused light passes through a corresponding modulator cell62E (and a corresponding aligned mask opening60). After passing through element54E, the light focused by the input lens element is collimated to form parallel or nearly parallel output by a corresponding output lens element in output lens array58. The lens elements of arrays50and58may, as examples, be plano-convex lens elements with their planar faces oriented towards each other. Other types of lens shapes may be used, if desired.

In some illustrative configurations, the optical properties of the lenses in lens array42may be electrically adjusted. Consider, as an example, adjustable lens elements100of the two-dimensional lens array ofFIG.8. Lens elements (lenses)100may be formed from liquid crystal material102or other material with an electrically adjustable refractive index that is located between first and second transparent substrates104. By applying electric fields to liquid crystal material102, the birefringence of material102in each lens element100may be individually adjusted. A polarizer may be used to polarize light from light source32before this light passes through material102in each lens element100, so that the adjustable birefringence results in a desired adjusted value of refractive index for the light passing through that element100.

Lens elements100may be adjusted using signals applied to transparent electrodes106. The pair of transparent electrodes106in each lens element100may, for example be supplied with a potentially different desired voltage, thereby controlling the electric field across the liquid crystal material of that lens element100. In this way, the electric field strength in the liquid crystal material of each lens element100adjusts the refractive index of that material and thereby changes the focal length and/or other refractive optical property of that lens. Lens elements100may have any suitable shape (e.g., the input and output surfaces of the lenses may include concave and/or convex lens surfaces, may include spherical surfaces, planar surfaces, and/or aspheric surfaces, the lenses may have rectangular outlines, circular outlines, hexagonal outlines, and/or other outlines to allow the lenses to be packed into a desired array, etc.). By adjusting the refractive optical properties of lenses100electrically, light can be focused and/or defocused, can be steered, and/or can otherwise be controlled to adjust the pattern of illumination provided by headlight16(see, e.g., the adjustable illumination patterns ofFIG.4).

The array of adjustable lens elements100ofFIG.8may serve as adjustable lens array42(e.g., light modulator array54may be omitted from array42) or the array of adjustable lens elements100ofFIG.8may form a part of adjustable lens array42. For example, a two-dimensional array of rows and columns of adjustable lens elements100may be used in place of lens array50and/or lens array58ofFIG.3. In this type of configuration, adjustments to the output of headlight16may be made by adjusting lenses100, by adjusting light modulator array54, and/or by adjusting light source32.

The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination.