Light system

Abstract

The light system (10) includes a VCSEL array (23) including plural VCSEL elements having a vertical cavity surface emitting laser (VCSEL) structure that emits light in the visible spectrum arranged on a substrate, a control unit (20A1) that controls operation of the VCSEL array (23), an optical unit (27a) provided in the VCSEL array (23) that projects light emitted by the VCSEL array (23), an optical shaping unit (27b) that shapes and outputs light projected from the optical unit (27a) into a specific illumination pattern, and a thermal management unit (20A3) that controls the temperature of the VCSEL array (23) so as to keep the temperature of the VCSEL array (23) within a specific temperature range. Each of the plural VCSEL elements (23) includes GaN.

Description

LIGHT SYSTEMThe present Disclosure relates to a Light system.Patent Document 1 discloses a vehicle headlamp. A vehicle headlamp disclosed in Patent Document 1 includes plural monolithic array light sources. Monolithic Array Light Source has vertical cavity surface emitting laser (VCSEL) structure which emits light in the visible spectrum. Moreover, the vehicle headlamp disclosed in Patent Document 1 includes a lens array, a phosphor plate, and a projection lens.The lens array adjusts the direction of emitted light from the VCSEL, and the phosphor plate shapes and outputs light from the lens array into a specific illumination pattern. The projection lens emits the light that has passed through the phosphor plate to an illumination region ahead of the vehicle. This enables the vehicle headlamp disclosed in Patent Document 1 to project light with a specific illumination pattern onto a road.There is room for improvement in the related art in order to further increase the output of the light of the illumination pattern.US Patent Publication No. US10746368The Light system disclosed herein is a VCSEL array in which a plurality of VCSEL elements, each having a vertical cavity surface emitting laser (VCSEL) structure configured to emit light in a visible spectrum, are arranged on a substrate;

[0001] a control unit configured to control operation of the VCSEL array;

[0002] an optical unit provided at the VCSEL array and configured to project light emitted by the VCSEL array;

[0003] an optical shaping unit configured to shape and output light projected from the optical unit in a specific illumination pattern; and

[0004] a thermal management unit configured to control the temperature of the VCSEL array such that the temperature of the VCSEL array remains within a specific temperature range,

[0005] wherein each of the plurality of VCSEL elements includes a semiconductor formed using gallium nitride (GaN).Fig. 1 is a diagram illustrating a configuration of a communication system according to an exemplary embodiment of the present disclosure.Fig. 2 is a diagram illustrating a Fig. 2 is a light system hardware configuration.Fig. 3 is a diagram illustrating an appearance of a light system..Fig. 4 is a diagram illustrating functionality of a light system.Fig. 5 is a diagram illustrating a configuration of a VCSEL array.Fig. 6 is a diagram illustrating a cross section of a VCSEL array and an optical unit.Fig. 7 is a diagram illustrating a cross section of a VCSEL array and an optical unit.Fig. 8 is a diagram illustrating a cross section of a VCSEL array and an optical unit.Fig. 9 is a diagram illustrating a cross section of a VCSEL array and an optical unit.Fig. 10 is a diagram illustrating a configuration example of a circulation unit.Fig. 11 is a diagram illustrating a configuration example of a circulation unit.Fig. 12 is a diagram illustrating a configuration example in a case in which a sealing unit is provided in the circulation unit illustrated in Fig. 10.Fig. 13 is a diagram illustrating a configuration example in a case in which a sealing unit is provided in the circulation unit illustrated in Fig. 11.Explanation follows regarding a light system according to an exemplary embodiment of the present disclosure, while referring to the drawings.Exemplary EmbodimentFig. 1 is a diagram illustrating a configuration of a communication system according to an exemplary embodiment of the present disclosure. The Communication System 100 may includes the multiple vehicles 10 and center server 200. The vehicle 10 may include an automobile or a two-wheeled vehicle.The multiple vehicles 10 and the center server 200 are connected in a communicable manner to each other through a wireless communication network N 10. The multiple vehicles 10 may be connected in a communicable manner to each other. The center server 200 may collects information transmitted from the vehicle 10. The center server 200 may provide information used for driving with the vehicle 10.The information may include information used for at least one of inter-vehicle communication or road-to-vehicle communication. Inter-vehicle communication may be construed to mean that plural vehicles 10 communicate with each other. Road-to-vehicle communication may be construed as the vehicle 10 communicating with infrastructure devices such as a road system. The information can acquire a real-time traffic situation, a real-time road situation, and the like by utilizing this information for inter-vehicle communication and road-to-vehicle communication. The control unit of the present disclosure uses this information to control the VCSEL array, to dynamically adjust the illumination pattern and to optimize lighting pattern. As a result of this operation driver's visibility can be improved. Details of the control unit are described later. Note that in inter-vehicle communication, plural vehicles situated at a predictable position can transmit data of information that can be used by each other. More specifically, light system installed in vehicle 10 encodes information, which is an electric signal, into an optical signal, and transmits the optical signal to the peripheral vehicle 10. The vehicle 10 that receives the optical signal decodes the optical signal into an electric signal, and performs driving assistance of the driver by utilizing information included in the electric signal.Next, explanation follows regarding a light system installed in the vehicle 10, with reference to Fig. 2 to Fig. 4. Fig. 2 is a diagram illustrating a light system hardware configuration. As illustrated in Fig. 2, vehicle 10 may have a light system 20 and plural ECU (Electronic Control Unit) 23.The light system 20 may be construed as an example of an onboard unit. The light system 20 is configured to a central processing unit (CPU) 20A, read only memory (ROM) 20B, random access memory (RAM) 20C, an internal communication interface (I / F) 20D, a radio communication I / F 20E, and an input / output I / F 20F. The light system 20 may further include a vehicle speed sensor 21, the camera 22, the VCSEL array 23, the temperature sensor 24, and the circulation unit 25.The CPUs 20A, the ROMs 20B, the RAMs 20C, the internal communication I / F 20D, the radio communication I / F 20E, and the input / output I / F 20F are connected so as to be capable of communicating with each other through internal buses 20G. ROM20B and RAM20C may be included in the memory 20I.The CPUs 20A execute various programs and control various functions. The CPU 20A reads a program from the ROM 20B, and executes the program on the RAM 20C as a workspace. The ROM 20B holds and obtain various programs and various data. More specifically, the ROM 20B may storage a control program for controlling the light system 20. The RAM 20C may temporarily store programs and date as a workspace.The internal communication I / F 20D is an interface for connecting the light system 20 with the ECU 29. The internal communication I / F 20D may use a communication protocol based on CAN (Controller Area Network) protocol. The internal communication I / F 20D is connected to the external bus 20H.The radio communication I / F 20E is an interface to perform at least one of vehicle-to-vehicle communication or road-to-vehicle communication. For example, communication standards such as 5G, LTE, Wi-Fi (registered trademark) can be used.The I / O I / F 20F is an interface for the CPU 20A to communicate with the vehicle speed sensor 21, the camera 22, the VCSEL array 23, the temperature sensor 24, and the circulation unit 25.The vehicle speed sensor 21 may be interpreted as a sensor that detects the speed of the vehicle 10. The speed information detected by vehicle speed sensor 21 may be input to the CPU 20A through the input / output I / F 20F. The speed information may be used to control light by the optical shaping unit. More specifically, the optical shaping unit of the present disclosure may use the speed information to shape the light projected from the optical unit into a specific illumination pattern. Details of the optical unit and the optical shaping unit will be described later.The camera 22 may be interpreted as a capturing means capable of capturing the situation peripheral the vehicle 10. The camera 22 may input captured data, which is data for a captured image, to the CPU 20A through the input / output I / F 20F. The imaged data may be used to analyze images by the feedback mechanism of the present disclosure. Details of the feedback mechanism are described later.The VCSEL array 23 may be interpreted as a laser device structure in which plural VCSEL elements are arranged on a substrate. The plural VCSEL elements may have a VCSEL structure that emits laser light in the visible spectrum. The plural VCSEL elements may be interpreted as semiconductor lasers each including gallium nitride (GaN). The plural VCSEL elements may include a switching circuit described later.GaN may be interpreted as a wide bandgap semiconductor. A wide bandgap semiconductor may be construed as a semiconductor whose bandgap is larger than the bandgap of silicon (Si). The wide bandgap semiconductors may have a characteristic that lattice-like number is small, and the chemical bonding force between the atoms is large. Moreover the wide bandgap semiconductors may have a characteristic that valence band are not easily excitedAccording to these characteristics, the wide bandgap semiconductors have dielectric breakdown field strength, thermal conductivity, saturation drift rate and so on higher than Si-based semiconductors or Gallium arsenide (GaAs) based semiconductors. More specifically, utilizing a wide bandgap semiconductor in a VCSEL element offers advantages such as suppression of calorific value, low thermal resistance, and high heat resistance.GaN semiconductors formed by using GaN is low losses and capable of high-speed switching operation compared to SiC based semiconductors. A semiconductor (SiC) formed using SiC is a mode of a wide band gap semiconductor. Accordingly, the use of a GaN semiconductor in the VCSEL array 23 enables the laser beam to be increased in output power, and enables the illumination pattern to be finely controlled.Since GaN semiconductors can achieve higher output and higher switching operation compared to Si based semiconductors, the temperature of VCSEL array 23 including a GaN semiconductor can be high. This enables the heat of the VCSEL array 23 to be transferred to circuits existing peripheral the VCSEL array 23. For this purpose, a structure that effectively cools the VCSEL array 23 is important. Configuration for cooling the VCSEL array 23 is described later.The ECU 29 can be interpreted as an electronic control unit that performs overall control of the vehicle 10. The ECU 29 can be provided to each of multiple functions provided for the vehicle 10. Multiple Functions are such as a braking, an actuator or the like.The temperature sensor 24 may be interpreted as a sensor that detects the temperature of the VCSEL array 23. The temperature sensor 24 outputs temperature information indicating the temperature of the VCSEL array 23. The temperature information may be used by the thermal management unit of the present disclosure. The temperature sensor 24 may detect a temperature of the VCSEL array 23 including a switching circuit described later. Details of the thermal management unit are described later.The circulation unit 25 may be construed as a mechanism that circulates a cooling medium for cooling the VCSEL array 23. The cooling medium may include air, cooling water, and the like. The circulation unit 25 may be construed as a mechanism provided in a heat dissipation member that is in contact with the VCSEL array 23. More specifically, the circulation unit 25 may include a refrigerant flow path formed in a heat dissipation member such as a heat sink, and a drive section such as a motor that causes a cooling medium to circulate through the refrigerant flow path.In a case in which the VCSEL array 23 is operating, a specific drive command can be transmitted from the thermal management unit to the circulation unit 25. The circulation unit 25 that receives the drive command causes the cooling medium to circulate through the refrigerant flow path by the motor being driven. The cooling medium is circulated so as to perform heat exchange between the refrigerant flow path and the cooling medium. This enables the VCSEL array 23 to be cooled.In a case in which the operation of the VCSEL array 23 is stopped, the transmission of the drive command from the thermal management unit to the circulation unit 25 is stopped. This enables rotation of the motor provided in the circulation unit 25 to be stopped, enabling power consumption by the circulation unit 25 to be suppressed.The light system 20 may include power parts for supplying power to the VCSEL array 23.Fig. 3 is a diagram illustrating an appearance of a light system.. As illustrated in Fig. 3, the light system 20 may include a substrate 26, a CPU 20A, a VCSEL array 23, a camera 22, a memory 20I, and an optical device 27.The CPU 20A, the VCSEL array 23, and the memory 20I are mounted on the substrate 26. The camera 22 is connected to the substrate 26.The substrate 26 may comprise a native substrate. The native substrate may include a GaAs wafer, a Si, GaN / sapphire substrate, a GaN / Si substrate, a GaN / SiC substrate, or the like. GaN / sapphire substrates may be interpreted as a substrate including sapphire. Sapphire has a hardness that follows diamond. Sapphire substrate has better heat resistance, corrosion resistance and heat radiation characteristics or the like compared to Si substrate.Since a GaN semiconductor is capable of higher power and higher speed operation than a semiconductor formed using Si, the operating temperature of the VCSEL array 23 can be increased. The use of sapphire substrate for the substrate 26 enables efficient radiation of the heat generated in the VCSEL array 23 including the GaN semiconductor. Namely, the heat radiation efficiency can be improved. The improved heat dissipation efficiency enables the operating temperature of the light system 20 to be kept within a specific temperature range even when a heat dissipation member such as a small heat sink is used. This enables a reduction in size of the light system 20.The optical device 27 may include an optical unit 27a and an optical shaping unit 27b.The optical unit 27a may be interpreted as a lens that projects light emitted by the VCSEL array 23. The optical unit 27a may be provided so as to be in contact with the VCSEL array 23. This enables the distance from the optical unit 27a to the VCSEL array 23 to be narrower than in a case in which the optical unit 27a is provided at a position away from the VCSEL array 23. This enables a reduction in size of the light system 20. Moreover, heat generated by the VCSEL array 23 is transferred to the optical unit 27a, enabling the heat dissipation efficiency of the VCSEL array 23 to be improved.The optical shaping unit 27b may be provided at a position spaced apart from the substrate 26 by a predetermined distance. The optical shaping unit 27b can be construed as a projection optical system for shaping the light projected from the optical unit 27a into a specific illumination pattern and outputting it. More specifically, a function (control unit) implemented by the CPU 20A controls a non-illustrated switching circuit based on information acquired via a communication interface. The switching circuit is configured to control light patterns projected from VCSEL array 23. The control unit and the switching circuit may manage the patterns projected on roads associated with scenes where light projected. Light projected from the VCSEL array 23 is input into optical shaping unit 27b as a projector lens through optical unit 27a as a micro lens. The optical shaping unit 27b shapes and outputs an illumination pattern adapted to a traffic situation or a road situation.(First Example of Illumination pattern)The optical shaping unit 27b includes at least one of a optical compensation element and a diffractive element. The control unit can be configured to dynamically shape the light projected from the optical unit 27a. The optical compensation element may be interpreted as an optical element for arranging the travel direction of light emitted from the plural VCSEL elements on the same plane. Diffractor may be interpreted as an optical element that transforms light emitted from plural VCSEL elements into various patterns, shapes, or the like."Dynamically shape" may be interpreted as changing the light projected from the optical unit 27a from the first illumination pattern to a second illumination pattern that is different from the first illumination pattern in response to a change in the road situation peripheral the vehicle 10.More specifically, in a case in which a traffic light on a road traveled by the vehicle 10 changes from blue to yellow, the control unit controls the switching circuit based on information acquired via the communication interface. This enables the illumination pattern emitted from the optical shaping unit 27b to be changed from the mark of the arrow extending in the direction in which the vehicle travels to the character [SLOW].Since the light projected from the optical unit 27a is dynamically shaped, the driver can intuitively grasp the changing road situation before and after the change, and the driving load on the driver can be reduced.(Second Example of Illumination pattern)The optical shaping unit 27b is a optical compensation element and a diffractive element It may include at least one of them. The control unit may distribute the light projected from the optical unit 27a so as to be adapted to the driving state of the vehicle 10. The driving state of the vehicle 10 may include a state in which the vehicle 10 is traveling at high speed during rainy weather, a state in which the vehicle 10 is traveling downhill at a low temperature, and the like.More specifically, in a case in which the vehicle 10 is traveling on a road at a speed of 100 km / h per hour during rainy weather, the control unit controls the switching circuit based on information acquired via the communication interface and speed information detected by the vehicle speed sensor 21. As a result, the illumination pattern emitted from the optical shaping unit 27b may be a character of [SLOW].Moreover, in a case in which the vehicle 10 is traveling when the outside air temperature is 0° C. or below, the control unit controls the switching circuit based on information acquired via the communication interface and temperature information detected by the detection sensor from the outside air temperature. Accordingly, the illumination pattern emitted from the optical shaping unit 27b may be a character [ICY ROAD].By distributing the light projected from the optical unit 27a so as to be adapted to the driving state of the vehicle 10, the driver can intuitively grasp the driving state of the vehicle 10, enabling the driving load on the driver to be reduced.(Third Example of Illumination pattern)The optical shaping unit 27b is a optical compensation element a diffractive element It may include at least one of them. The control unit can customize the illumination pattern so as to fit the environment existing peripheral the vehicle 10 installed with the light system 20. The vehicle 10 installed with the light system 20 may be interpreted as a first vehicle. The environment existing peripheral the vehicle 10 may include states of traffic lights existing in a travel direction of the vehicle 10, states on roads extending in a travel direction of the vehicle 10, and the like.More specifically, in a case in which a traffic light on a road traveled by the vehicle 10 is blue, the control unit controls the switching circuit based on information acquired via the communication interface. Accordingly, the illumination pattern emitted from the optical shaping unit 27b may be a mark of an arrow extending in a direction in which the vehicle 10 travels.In a case in which a traffic light on a road traveled by the vehicle 10 is red, the control unit controls the switching circuit based on information acquired via the communication interface. Accordingly, the illumination pattern emitted from the optical shaping unit 27b may be a character [STOP].Moreover, in a case in which a pedestrian has jumped out of the road on which the vehicle 10 travels, the control unit controls the switching circuit based on information obtained by analyzing the captured data of the camera 22. Accordingly, the illumination pattern emitted from the optical shaping unit 27b may be a character "Caution".Customization of illumination pattern associated with the environment peripheral the vehicle 10 can reduce the driving load on the driver. In particular, the driving load during nighttime can be greatly reduced.The optical shaping unit 27b may output specific optical patterns as the illumination patterns for making communications with a person present peripheral the first vehicle installed with the light system 20 or with the second vehicle present peripheral the first vehicle. Light patterns may include at least one of a display indicating a warning, or a display indicating travel direction of the first vehicle.The control unit may dynamically adjust emission strength of the VCSEL array 23 and the illumination patterns by controlling the operation of the VCSEL array 23 based on at least one of vehicle speed, weather conditions, road conditions, and settings by the driver of the first vehicle installed with the light system.Fig. 4 is a diagram illustrating functionality of a light system. As illustrated in Fig. 4, the CPU 20A may include the control unit 20A1, the analysis section 20A2, and the thermal management unit 20A3. The control unit 20A1, the analysis section 20A2, and the thermal management unit 20A3 can be implemented by the CPU 20A executing a write control program loaded into the RAM 20C (Fig. 2).The control unit 20A1 may control operation of the VCSEL array 23. More specifically, the control unit 20A1 may control the switching circuit to change the illumination pattern emitted from the optical shaping unit 27b.The analysis section 20A2 may be included in the feedback mechanism 28. The analysis section 20A2 may analyze images captured by the camera 22 by utilizing a specific image analysis algorithms when captured data from the camera 22 is input into. The control unit 20A1 may generate drive commands for customizing the illumination patterns based on the analysis result of the analysis section 20A2 and input to a switching circuit.The thermal management unit 20A3 may control the temperature of the VCSEL array 23 so as to keep the temperature of the VCSEL array 23 remains within a specific temperature range (25 to 80° C.). More specifically, the thermal management unit 20A3 controls the flow rate of the cooling medium based on the temperature information transmitted from the temperature sensor 24.The feedback mechanism 28 may be interpreted as a mechanism that generates a feedback signal to continue operation of the VCSEL array 23 based on a specific parameter, and inputs this generated feedback signal to the control unit 20A1. The control unit 20A1 may be interpreted as an electronic control circuit to play an important role in ensuring reliability and safety of the light system 20. The specific parameters may be interpreted as parameters relating to operation of the VCSEL array 23. The parameters may include temperature of VCSEL array 23, electric power level consumed by the VCSEL array 23, the other values relating to the operation of VCSEL array 23, or the like.The feedback mechanism 28 may continuously monitor operating conditions, performance, safety parameters, and the like of the light system 20. The control unit 20A1 can detect, by utilizing the feedback mechanism 28, that an operation condition of the light system 20 is deviated. The control unit 20A1 can actively detect, by utilizing the feedback mechanism 28, an abnormal condition of the light system 20. This enables the light system 20 to maintain optimal operation.The feedback mechanism 28 may evaluate the particular parameter to ensure that the particular parameter is within a certain range that is safe and efficient. In cases in which the specific parameter is outside the specific range, the feedback mechanism 28 may inform the control unit 20A1 of this fact. The control unit 20A1 can dynamically adjust settings by monitoring information from the feedback mechanism 28. The settings may include an output power amount of the VCSEL array 23, an amount of modulation of light output from the VCSEL array 23, and the like.The feedback mechanism 28 may stably operate the VCSEL array 23 by determining whether or not a temperature, power, or the like detected by the various sensors is within a preset threshold value. More specifically, in a case in which the power consumed by the VCSEL array 23 has exceeded a specific threshold, the feedback mechanism 28 may transmit a command to the control unit 20A1 so as to execute control to reduce the power. This enables the risk of abnormal operation of the light system 20 to be suppressed due to excessive heat generation, power surges, and other potential factors.Fig. 5 is a diagram illustrating a configuration of the VCSEL array 23. The VCSEL array 23 may include plural individually addressable VCSEL elements 23a. Arrangement of plural of VCSEL elements 23a may be set based on the characteristic, operational condition of VCSEL array 23 and so on.As illustrated in Fig. 5, the plural VCSEL elements 23a may be configured by a triangular periodic grating pattern. More specifically, the VCSEL array 23 may include plural of virtual triangular lattice patterns periodically formed on the substrate 26. The plural of triangular lattice patterns may divide the surface of the substrate 26 into regions of equilateral triangles of the same shape. Respective vertices of the equilateral triangle may be correspond to positions at which the VCSEL element 23a is disposed.Triangular The lattice pattern enables the density at which the plural VCSEL elements 23a are mounted on the substrate 26 to be increased. Namely, the packaging density of the VCSEL array 23 can be increased by utilizing the triangular grid patterns.The VCSEL array 23 may include plural electrode pads 23b. The electrode pads 23b may be connected together according to a specific pattern in order to address the individual VCSEL elements 23a. The plural electrode pads 23b may be electrically connected to the one or plural VCSEL elements 23a.The electrode pads 23b may be configured according to an active matrix method. In the active matrix method, both the VCSEL elements 23a arranged in the vertical direction and the horizontal direction can be selectively turned on (activated) or off (deactivated), enabling a target illumination pattern to be implemented.The active matrix method may be interpreted as a method in which the VCSEL elements 23a are arranged at respective intersections of electrodes arranged in a grid pattern, and the VCSEL elements 23a situated at the electrodes in which both the vertical axis (Y axis) and the horizontal axis (X axis) are energized are turned on or off. By the active matrix method, the VCSEL elements 23a can become active at intersections of the electrode pads 23b arranged in a grid pattern. In order to facilitate controlling of VCSEL elements 23a of the active matrix method, a dedicated control substrate, not illustrated, may be connected to the substrate 26. The control substrate may be construed as the aforementioned switching circuit.The control substrate is provided with a switch configured by transistors and capacitor elements. The control substrate may be interpreted as a complementary metal oxide semiconductor (CMOS) circuit substrate for active matrix operation of the VCSEL array 23. The switch on the CMOS circuit substrate and the X-axis voltage are operated to control on / off of the VCSEL element 23a. The VCSEL element 23a situated at the intersection of the X-axis and the Y-axis is illuminated in a case in which the corresponding Y-axis is energized in an on state.This enables the on or off states of the individual VCSEL elements 23a to be accurately controlled, enabling interference and crosstalk between adjacent VCSEL elements 23a to be suppressed to a minimum.By utilizing with the appropriate control circuit, VCSEL array 23 can achieve efficient and accurate illumination patterns based on the particular requirements of the applicationPassive matrix system can be applied to VCSEL array 23 instead of active matrix system. The passive matrix method may be interpreted as a method in which the VCSEL element 23a is turned on or off by arranging electrodes not including the above-described switch (a switch configured by a transistor and a capacitor element) in a lattice pattern.In Passive matrix method in a case in which the VCSEL elements 23a are arranged in a two-dimensional pattern, however, light bleeding, light leakage, and the like can occur.Since high quality image projection is not an important requirement in a headlight of the vehicle 10, the VCSEL array 23 may include a relatively small number of VCSEL elements 23a, typically from 1,000 to 50,000.Whether to choose an active matrix scheme or a passive matrix scheme differs depending on the requirements and constraints of a particular application. Since the passive matrix systems have simple structures and highly cost efficiency, the passive matrix system are suitable for use in applications being not required with high image quality and high-contrast. In the passive matrix systems, capacitor elements, namely storage elements, is not utilized. For this reason, a minute voltage applied to the VCSEL element 23a may affect the VCSEL element 23a present around the VCSEL element 23a, causing problems such as light bleeding, disturbance, and the like.Therefore, in the passive matrix system, the contrasts of projected images tend to be lower than the active matrix system.The present disclosed VCSEL array 23 may selectively control the illumination patterns by driving plural of VCSEL elements 23a in active matrix method or in passive matrix method.Next, explanation follows regarding configuration examples of the VCSEL array 23 and the optical unit 27a, with reference to Fig. 6 to Fig. 9.Fig. 6 to Fig. 9 are diagrams illustrating cross sections of a VCSEL array and an optical unit. Fig. 6 shows a first configuration example (hereafter Type 1) of the VCSEL array 23. Fig. 7 shows a second configuration example (hereafter Type 2) of the VCSEL array 23. Fig. 8 shows a third configuration example (hereafter Type 3) of the VCSEL array 23. Fig. 9 shows a fourth configuration example (hereafter Type 4) of the VCSEL array 23.Each of the VCSEL arrays 23 of types 1 to 4 may include a VCSEL element 23a and a lens provided on a surface of the VCSEL element 23a. The lens may be interpreted as the optical unit 27a.The type 1 and type 2 VCSEL arrays 23 may utilize lenses (sapphire lenses) including sapphire. The sapphire lens is formed so as to be continuous with the surfaces of the plural adjacent VCSEL elements 23a.In the type 1 and type 2 VCSEL arrays 23, the lenses are present on a sapphire substrate, and the VCSEL elements 23a, including GaN material, are aligned with the lenses.The VCSEL array 23 of type 1 does not include a wavelength conversion material, but in the VCSEL array 23 of type 2, a wavelength conversion material is provided on a lens. More specifically, in the type 2 VCSEL array 23, the lenses on the VCSEL elements 23a are coated with a wavelength conversion material.The type 3 and type 4 VCSEL arrays 23 are different types of VCSEL arrays 23 fabricated using only GaN material. The type 3 and type 4 VCSEL arrays 23 may each be interpreted as a VCSEL array 23 that does not include sapphire.A lens (GaN lens) including a GaN material is used for each of the VCSEL arrays 23 of Type 3 and Type 4. In the type 3 and type 4 VCSEL arrays 23, plural GaN lenses are provided on a substrate 26 by an epitaxial lateral overgrowth (ELO) method. This lens is aligned with the VCSEL element 23a.The VCSEL array 23 of type 3 does not include a wavelength conversion material, but in the VCSEL array 23 of type 4, a wavelength conversion material is provided on a lens. More specifically, in the type 4 VCSEL array 23, the lenses on the VCSEL elements 23a are coated with a wavelength conversion material.In the VCSEL arrays 23 of Type 3 and Type 4, since lenses are provided in each of the plural VCSEL elements 23a, gaps are formed between adjacent lenses.As described above, the type 1 and type 3 VCSEL arrays 23 do not include a wavelength conversion material, and therefore emit light having a wavelength in the range of 400 to 450 nm that falls within the blue region of the visible spectrum. The type 1 VCSEL array 23 utilizes sapphire lenses, enabling the substrate 26 to be diced into large blocks.The type 1 and type 3 VCSEL arrays 23 utilize the electrical insulating properties of sapphire, enabling the VCSEL elements 23a to be arranged in a passive matrix format. This enables a selective illumination pattern to be implemented. This enables the degrees of freedom for design to be increased in order to realize a specific illumination pattern.Moreover, the VCSEL arrays 23 of Type 1 and Type 3 do not include a wavelength conversion material, and the sapphire lens elements and the passive matrix configuration are combined, enabling the manufacturing cost of the VCSEL arrays 23 to be reduced.As another configuration example, a lens can be fabricated using a GaN material by separating an array including the VCSEL elements 23a from a host substrate. In this configuration example, an active matrix scheme or a passive matrix scheme can be applied over the array block to control the illumination pattern. This enables accurate control of the illumination pattern to be implemented, enabling it to be flexibly adapted to specific application requirements.As described above, the type 2 and type 4 VCSEL arrays 23 each include a wavelength conversion material. The wavelength conversion material includes a phosphor material capable of converting a wavelength of light emitted from the VCSEL array 23 to a second wavelength that is different from the first wavelength, and of outputting light of the second wavelength.By changing the wavelength of the light, the color of the light emitted from the VCSEL array 23 can be changed to another color. Namely, the primary colors of the VCSEL array 23 can be converted using the wavelength conversion material. Warm white light or cold white light can be obtained depending on the composition of the phosphor material included in the wavelength conversion material.Photolithography or a direct printing method can be applied to the application of the wavelength conversion material to the lens. A wavelength conversion material may be applied to the type 2 VCSEL array 23 employing a sapphire lens by this method. A wavelength conversion material may be applied to the type 4 VCSEL array 23 including a GaN lens in a similar manner.Next, explanation follows regarding a configuration example of the circulation unit 25, with reference to Fig. 10 and Fig. 11. Fig. 10 and Fig. 11 are diagrams illustrating configuration examples of a circulation unit.In the light system 20 including a GaN semiconductor, thermal management plays an important role in order to maintain optimum performance and extend the life of the light system 20. It is desirable that the continuous operation of the VCSEL element 23a enables the heat generated by the VCSEL element 23a to be efficiently radiated. Examples of structures that effectively radiate heat include the circulating section 25A illustrated in Fig. 10 and the circulating section 25B illustrated in Fig. 11.The circulation unit 25A illustrated in Fig. 10 may be construed as a cooling structure to which transmission-mode is applied. Transmission-mode may be construed as a mode in which the light emitted from the VCSEL array 23 is passed through the phosphor material without being reflected.The circulating section 25B illustrated in Fig. 11 may be construed as a structure to which a reflection mode is applied. The reflection mode may be construed as a mode in which the light emitted from the VCSEL array 23 is reflected and emitted by the phosphor material.(Configuration of the Circulating Section 25A)The circulation unit 25A illustrated in Fig. 10 includes a heat sink 25a, two supporting members 25b provided in the heat sink 25a, and a plate-shaped phosphor material 25c supported by the two supporting members 25b. The two supporting members 25b are arranged on the heat sink 25a at a predetermined distance apart from each other. Each of the two support members 25b may be construed as a hollow cylindrical member. The plate-shaped phosphor material 25c may be interpreted as a wavelength conversion material.The two supporting members 25b can support phosphor materials while function as an input port and an output port of cooling medium. Cooling medium can pass through the hollow portions of the two support members 25b.More specifically, the cooling medium may enter the supporting member 25b provided above the heat sink 25a. The cooling medium can be discharged from the supporting member 25b provided below the heat sink 25a after passing through the coolant flow path formed inside the heat sink 25a. The discharged cooling medium may enter the supporting member 25b again after being cooled by passing through a heat dissipation section (not illustrated).The cooling medium is circulated in the circulation unit 25A, whereby heat exchange is performed between the cooling medium and the phosphor material 25c. Heat exchange is performed between the cooling medium and the VCSEL element 23a.The heat sink 25a is in contact with the VCSEL array 23. In order to enhance heat transfer, a thermal spreader material such as thermal paste may be provided between the heat sink 25a and the VCSEL array 23.When the light emitted from the VCSEL element 23a pass through phosphor materials 25c, the wave length of this light is converted. As a result of this, the color of the light projected from the optical unit 27a can be changed to cold white or warm white. The circulating section 25A can support a irradiation optical system, not shown in drawings, by using the two supporting members 25b. In the projection optical system, the light that has passed through phosphor materials 25c is input.(Configuration of the Circulating Section 25B)The circulation unit 25B illustrated in Fig. 11 includes a structural body 25d formed in a U-shaped cross section, and a cooling medium passage 25e. The structure 25d may be interpreted as a heat sink for radiating heat from the VCSEL array 23. The plate-shaped phosphor material 25c is provided on an inner surface of the structure 25d.More specifically, the phosphor material 25c is provided on the inner surface 25d1 of the structure 25d. More specifically, the phosphor material 25c is provided in a region of the inner surface 25d1 of the structure 25d that is closer to the opening 25f. A region closer to the opening 25f may be interpreted as a region of the inner surface 25d1 of the structure 25d that is opposite to the bottom 25d2 side of the structure 25d.The cooling medium passage 25e may be interpreted as a hollow tube provided inside the structure 25d. A first end portion of the cooling medium passage 25e is provided above the structure 25d. A second end portion of the cooling medium passage 25e is provided below the structure 25d.A plurality of VCSEL elements 23a and a plurality of plate-shaped phosphor materials 25c are provided on an inner surface of the structure 25d. A central portion of the cooling medium passage 25e is disposed near the plural VCSEL elements 23a.The cooling medium can pass through the cooling medium passage 25e. More specifically, the cooling medium may enter the first end portion of the cooling medium passage 25e, pass near the phosphor material 25c and the VCSEL element 23a, and then be discharged from the second end portion of the cooling medium passage 25e. The cooling medium flows through the cooling medium passage 25e, whereby heat exchange is performed between the cooling medium and the phosphor material 25c. Heat exchange is performed between the cooling medium and the VCSEL element 23a.When the light emitted from the VCSEL element 23a is reflected on the phosphor materials, wave length of this light is converted. As a result of this, the color of the light projected from the optical unit can be changed to cold white or warm white.Note that the opening 25f of the structure 25d may be formed so as to be able to accommodate a non-illustrated projection optical system. The light reflected by the phosphor materials 25c is input In the projection optical system.The circulation unit 25A and the circulation unit 25B enable the VCSEL array 23 and the phosphor material 25c to be cooled. By maintaining the operating temperature of both the VCSEL element 23a and the phosphor material 25c at a low value, it is possible to suppress a high temperature of the light system 20. This enables an efficient light illumination pattern with high reliability to be implemented. Effective radiation of heat generated from both the VCSEL element 23a and the phosphor material 25c enables continuous operation to be implemented in the transmission mode and the reflection mode, therefore, performance is improved.The circulation unit 25A and the circulation unit 25B can equip a spring loader to reduce vibration of the projection optical system, an auto-focus adjustment function and the like for enhancing functionality.Next, with reference to Fig. 12 and Fig. 13, a configuration example of a sealing unit for hermetic sealing of VCSEL Array. In the light system 20 including a GaN semiconductor, it is important to improve the sealing degree of the light system 20 in order to protect components from external elements (dust, water, or the like) that may degrade performance.Fig. 12 is a diagram illustrating a configuration example in a case in which a sealing unit is provided in the circulation unit 25A illustrated in Fig. 10. Fig. 13 shows a configuration example in a case that a sealing unit is provided for the circulation unit 25B shown in Fig. 11. The optical shaping unit 27b illustrated in Fig. 12 and Fig. 13 is construed as the projection optical system described above.As illustrated in Fig. 12, between the optical shaping unit 27b and the supporting member 25b, a sealing unit 25g is provided. The sealing unit 25g may include epoxy, solder and the like. The sealing unit 25g can fix the projection optical system on the structure 25d and achieve highly reliable sealing for preventing infiltration of external elements.As illustrated in Fig. 13, between the optical shaping unit 27b and the structure 25d, sealing unit 25g may be provided as well as above mentioned.In addition to the sealing unit 25g, a spring loader and a variable focus arm may be installed in the circulation unit 25A and the circulation unit 25B. These functions not only ensure stability, but also enable advanced focusing functionality, enabling to accurately control and adjust optical power.The hermetic sealing enables a robust light system 20 to be obtained against external factors that may degrade performance. As a result, the operation of the light system 20 can be stabilized and the life of the light system 20 can be longer.As described above, the light system 20 of the present disclosure includes the VCSEL array 23 including a GaN semiconductor, enabling the light output of the illumination pattern to be further improved. Moreover, since the light system 20 equip the temperature control section 20A3, the temperature of the VCSEL array 23 to be controlled so as to keep the temperature of the VCSEL array 23 within a specific temperature range even in cases in which a switching circuit configured by a GaN semiconductor, the VCSEL element 23a, or the like is at a high temperature.Since the size of the switching circuit, the VCSEL array 23, and the like can be reduced in comparison to cases in which Si semi-conductors are used, the projection optical system can be simplified. The light system 20 of the present disclosure is capable of changing an illumination pattern of light without providing a complicated aberration correction optical system.In the VCSEL array 23 including a GaN semiconductor, since the radiation shape of the laser is circular, the configuration of the projection optical system that focuses the laser onto a specific illumination pattern can be simplified. Moreover, setup of the projection optical system can be facilitated. Moreover, when an optical fiber is used, light transmission can be facilitated.Although the present disclosure focuses primarily on lighting modules for vehicles, the light system 20 of the present disclosure may be applied to mobility such as avionics, drones, railroads, ocean lighting, and the like. The light system 20 of the present disclosure may also be applied to portable flashlights, light bars, high-lumen spotlights for avionics, search and rescue of helicopters, and security. The light system 20 of the present disclosure can be applied to special lighting such as entertainment or outdoor lighting.(Appendix)The following appendices are further disclosed regarding the above exemplary embodiments.Appendix 1A lighting system, comprising:

[0006] a VCSEL array in which a plurality of VCSEL elements, each having a vertical cavity surface emitting laser (VCSEL) structure configured to emit light in a visible spectrum, are arranged on a substrate;

[0007] a control unit configured to control operation of the VCSEL array;

[0008] an optical unit provided at the VCSEL array and configured to project light emitted by the VCSEL array;

[0009] an optical shaping unit configured to shape and output light projected from the optical unit in a specific illumination pattern; and

[0010] a thermal management unit configured to control the temperature of the VCSEL array such that the temperature of the VCSEL array remains within a specific temperature range,

[0011] wherein each of the plurality of VCSEL elements includes a semiconductor formed using gallium nitride (GaN).Appendix 2The lighting system of claim 1, further comprising a wavelength conversion material including a phosphor material, which converts a wavelength of the light that is to be projected from the optical unit from a first wavelength to a second wavelength that is different from the first wavelength, and outputs the light, at the second wavelength, to the optical unit.Appendix 3The lighting system of claim 2, wherein the wavelength conversion material is coated onto the plurality of VCSEL elements.Appendix 4The lighting system of claim 1, further comprising a circulation unit in which a cooling medium that cools the VCSEL array circulates,

[0012] wherein the thermal management unit controls a flow rate of the cooling medium based on temperature information transmitted from a temperature sensor that detects a temperature of the VCSEL array.Appendix 5The lighting system of claim 1, further comprising a feedback mechanism configured to generate a feedback signal for continuing operation of the VCSEL array and input the generated feedback signal to the control unit, based on specific parameters relating to the operation of the VCSEL array.Appendix 6The lighting system of claim 1, wherein:

[0013] the optical shaping unit includes at least one of an optical compensation element or a diffractive element, and

[0014] the control unit is configured to dynamically shape the light projected from the optical unit.Appendix 7The lighting system of claim 1, wherein:

[0015] the optical shaping unit includes at least one of an optical compensation element or a diffractive element, and

[0016] the control unit is configured to distribute the light projected from the optical unit in a manner adapted to a travel state of a vehicle.Appendix 8The lighting system of claim 1, wherein:

[0017] the optical shaping unit includes at least one of an optical compensation element or a diffractive element, and

[0018] the control unit is configured to customize the illumination pattern in a manner adapted to a peripheral environment of a first vehicle installed with the lighting system.Appendix 9The lighting system of claim 1, further comprising a communication interface configured to perform at least one of inter-vehicle communication in which information is transmitted and received by communication with peripheral vehicles via a wireless communication network, or road-to-vehicle communication in which information is transmitted and received by communication with peripheral infrastructure devices via the wireless communication network,

[0019] wherein the control unit is configured to shape the light projected from the optical unit into the illumination pattern, which is adapted to a traffic situation or a road situation, and output the light, by controlling the VCSEL array based on the information acquired via the communication interface.Appendix 10The lighting system of claim 1, wherein:

[0020] the VCSEL structure includes a plurality of virtual triangular lattice patterns periodically formed on the substrate,

[0021] the plurality of triangular lattice patterns divide a surface of the substrate into regions of equilateral triangles of the same shape, and

[0022] respective vertices of the equilateral triangles correspond to positions at which the VCSEL elements are disposed.Appendix 11The lighting system of claim 2, wherein the phosphor material imparts a cold white color or a warm white color to a color of the light projected from the optical unit.Appendix 12The lighting system of claim 2, wherein:

[0023] the substrate comprises a sapphire substrate, and

[0024] the phosphor material is provided on the sapphire substrate.Appendix 13The lighting system of claim 2, wherein:

[0025] the optical unit includes a gallium nitride (GaN) material, and

[0026] the phosphor material is provided at the optical unit.Appendix 14The lighting system of claim 1, wherein the illumination pattern is selectively controlled by active matrix driving or passive matrix driving of the plurality of VCSEL elements.Appendix 15The lighting system of claim 1, further comprising a sealing unit configured to hermetically seal the VCSEL array.Appendix 16The lighting system of claim 1, wherein:

[0027] the optical shaping unit outputs, as the illumination pattern, a specific light pattern for communication with a person present in a periphery of a first vehicle installed with the lighting system or with a second vehicle present in the periphery of the first vehicle, and

[0028] the light pattern includes at least one of a display indicating a warning or a display indicating a travel direction of the first vehicle.Appendix 17The lighting system of claim 5, wherein:

[0029] the feedback mechanism is configured to analyze an image captured by a camera using a specific image analysis algorithm, and

[0030] the control unit is configured to generate a command for customizing the illumination pattern based on an analysis result of the image analyzed by the feedback mechanism, and input the command to the VCEL array.Appendix 18The lighting system of claim 1, wherein the control unit is configured to dynamically adjust a light emission intensity of the VCSEL array and the illumination pattern by controlling the operation of the VCSEL array based on at least one of vehicle speed, weather conditions, road conditions, or a setting by a driver of a first vehicle installed with the lighting system.Although exemplary embodiments of the present disclosure have been described above with reference to exemplary embodiments, these exemplary embodiments are examples, and various modifications may be implemented within a range not departing from the spirit of the present disclosure. It is needless to say that the scope of the present disclosure is not limited to these exemplary embodiments.All documents, patent applications, and technical standards described herein are incorporated by reference to the same extent as if the individual documents, patent applications, and technical standards were specifically and individually noted to be incorporated by reference.The at of the exemplary embodiments may be executed by various types of processing Excluding the relevant processor executed by reading and executing software (programs). Examples of processors include programmable logic devices (PLD) that allow circuit configuration to be modified post-manufacture, such as a field-programmable gate array (FPGA), and dedicated electric circuits, these being processors including a circuit configuration custom-designed to execute specific processing, such as an application specific integrated circuit (ASIC). The receiving processing described above may be executed by any one of these various types of processor, or by a combination of two or more of the same type or different types of processor (such as plural FPGAs, or a combination of a CPU and an FPGA). The hardware structure of these various types of processors is an electric circuit May be construed as combining circuit elements such as semiconductor elements.DESCRIPTION OF THE PREFERRED EMBODIMENTS10 Vehicle20 Light system20A CPU20A1 Control unit20A2 Analysis section20A3 Thermal management unit20B ROM20C RAM20D Internal communication I / F20E Radio communication I / F20F Input / output I / F20G Internal bus20H External bus20I Memory21 Vehicle speed sensor22 Camera23 VCSEL array23a VCSEL element23b Electrode pad24 Temperature sensor25 Circulation unit25A Circulation unit25B Circulation unit25a Heat sink25b Support member25c Phosphor material25d Structure25d1 Medial surface25d2 Bottom25e Cooling medium passage25f Opening25g Sealing unit26 Substrate27 Optical device27a Optical unit27b Optical shaping unit28 Feedback mechanism29 ECU100 Communication System200 Center server

Claims

1. A lighting system, comprising: a VCSEL array in which a plurality of VCSEL elements, each having a vertical cavity surface emitting laser (VCSEL) structure configured to emit light in a visible spectrum, are arranged on a substrate; a control unit configured to control operation of the VCSEL array; an optical unit provided at the VCSEL array and configured to project light emitted by the VCSEL array; an optical shaping unit configured to shape and output light projected from the optical unit in a specific illumination pattern; and a thermal management unit configured to control the temperature of the VCSEL array such that the temperature of the VCSEL array remains within a specific temperature range, wherein each of the plurality of VCSEL elements includes a semiconductor formed using gallium nitride (GaN).

2. The lighting system of claim 1, further comprising a wavelength conversion material including a phosphor material, which converts a wavelength of the light that is to be projected from the optical unit from a first wavelength to a second wavelength that is different from the first wavelength, and outputs the light, at the second wavelength, to the optical unit.

3. The lighting system of claim 2, wherein the wavelength conversion material is coated onto the plurality of VCSEL elements.

4. The lighting system of claim 1, further comprising a circulation unit in which a cooling medium that cools the VCSEL array circulates, wherein the thermal management unit controls a flow rate of the cooling medium based on temperature information transmitted from a temperature sensor that detects a temperature of the VCSEL array.

5. The lighting system of claim 1, further comprising a feedback mechanism configured to generate a feedback signal for continuing operation of the VCSEL array and input the generated feedback signal to the control unit, based on specific parameters relating to the operation of the VCSEL array.

6. The lighting system of claim 1, wherein: the optical shaping unit includes at least one of an optical compensation element or a diffractive element, and the control unit is configured to dynamically shape the light projected from the optical unit.

7. The lighting system of claim 1, wherein: the optical shaping unit includes at least one of an optical compensation element or a diffractive element, and the control unit is configured to distribute the light projected from the optical unit in a manner adapted to a travel state of a vehicle.

8. The lighting system of claim 1, wherein: the optical shaping unit includes at least one of an optical compensation element or a diffractive element, and the control unit is configured to customize the illumination pattern in a manner adapted to a peripheral environment of a first vehicle installed with the lighting system.

9. The lighting system of claim 1, further comprising a communication interface configured to perform at least one of inter-vehicle communication in which information is transmitted and received by communication with peripheral vehicles via a wireless communication network, or road-to-vehicle communication in which information is transmitted and received by communication with peripheral infrastructure devices via the wireless communication network, wherein the control unit is configured to shape the light projected from the optical unit into the illumination pattern, which is adapted to a traffic situation or a road situation, and output the light, by controlling the VCSEL array based on the information acquired via the communication interface.

10. The lighting system of claim 1, wherein: the VCSEL structure includes a plurality of virtual triangular lattice patterns periodically formed on the substrate, the plurality of triangular lattice patterns divide a surface of the substrate into regions of equilateral triangles of the same shape, and respective vertices of the equilateral triangles correspond to positions at which the VCSEL elements are disposed.

11. The lighting system of claim 2, wherein the phosphor material imparts a cold white color or a warm white color to a color of the light projected from the optical unit.

12. The lighting system of claim 2, wherein: the substrate comprises a sapphire substrate, and the phosphor material is provided on the sapphire substrate.

13. The lighting system of claim 2, wherein: the optical unit includes a gallium nitride (GaN) material, and the phosphor material is provided at the optical unit.

14. The lighting system of claim 1, wherein the illumination pattern is selectively controlled by active matrix driving or passive matrix driving of the plurality of VCSEL elements.

15. The lighting system of claim 1, further comprising a sealing unit configured to hermetically seal the VCSEL array.

16. The lighting system of claim 1, wherein: the optical shaping unit outputs, as the illumination pattern, a specific light pattern for communication with a person present in a periphery of a first vehicle installed with the lighting system or with a second vehicle present in the periphery of the first vehicle, and the light pattern includes at least one of a display indicating a warning or a display indicating a travel direction of the first vehicle.

17. The lighting system of claim 5, wherein: the feedback mechanism is configured to analyze an image captured by a camera using a specific image analysis algorithm, and the control unit is configured to generate a command for customizing the illumination pattern based on an analysis result of the image analyzed by the feedback mechanism, and input the command to the VCEL array.

18. The lighting system of claim 1, wherein the control unit is configured to dynamically adjust a light emission intensity of the VCSEL array and the illumination pattern by controlling the operation of the VCSEL array based on at least one of vehicle speed, weather conditions, road conditions, or a setting by a driver of a first vehicle installed with the lighting system.

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