Headlamp device

Abstract

A headlamp device (100) is a headlamp device for a vehicle, which has a light source section (10) having a plurality of light emitting sections (11, 12, 13, 14) that emit light of mutually different light distribution (S11, S12, S13, S14), illuminating light (L1) that emits a resultant light distribution (S1, S2) obtained by combining the light distributions (S11, S12, S13, S14) of the plurality of light emitting sections (11, 12, 13, 14), an acquisition section (20) that acquires environmental information indicating a surrounding environment of an illumination area of the headlamp device (100), and a control section (30) that controls the light distribution (S11, S12, S13, S14) of each of the plurality of light emitting sections (11, 12, 13, 14) based on the environmental information acquired by the acquisition section (20).

Description

Technical Field

[0001] This disclosure relates to headlight devices for vehicles. Background Technology

[0002] The use of light-emitting diodes (LEDs) as the light source for vehicle headlights is increasing, as these technologies have become more widespread in recent years. For example, when white light is emitted from a headlight, it is generated by combining a blue LED with a yellow phosphor. This allows for the efficient generation of white light with a low-cost structure.

[0003] The structure used to generate white light is not limited to a combination of a blue LED and a yellow phosphor; other structures are also known. See, for example, Patent Document 1. Furthermore, in vehicle headlight devices, techniques are known to improve driver visual recognition by controlling the spectral distribution of light of colors other than white light.

[0004] The headlight device of Patent Document 1 has a first LED unit consisting of a blue LED covered by a phosphor, and a second LED unit consisting of a combination of LEDs of three colors (red, green, and blue). Furthermore, the headlight device of Patent Document 1 has a control unit that controls at least one of the brightness and color temperature of the first LED unit and the second LED unit based on the surrounding environment of the illumination environment of the headlight device.

[0005] Here, as a characteristic of human vision, the Purkinje phenomenon, which occurs in mesoscopic or scotopic environments such as roads at night, is known to cause a shift in the sensitivity of the human eye to brightness towards shorter wavelengths. Therefore, by making the spectral distribution of the illumination light shining onto the road at night contain more short-wavelength components, a person (i.e., the driver) perceives brightness. In the headlight device of Patent Document 1, the first LED unit and the second LED unit are each equipped with a blue LED, thus the generated white light contains more short-wavelength blue components.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2020-32803 Summary of the Invention

[0009] The problem the invention aims to solve

[0010] However, in headlights where the white light emitted contains a significant amount of short-wavelength blue components, this light can be scattered by raindrops or other sources during inclement weather such as rain or fog, resulting in reflected light that reaches the driver's eyes. Excessive reflected light can cause glare (also known as "dazzle") and reduce visual acuity.

[0011] The purpose of this disclosure is to provide a headlight device that improves the driver's visual recognition.

[0012] means for solving problems

[0013] One disclosed headlight device is a vehicle headlight device, characterized by comprising: a light source unit having multiple light-emitting units that emit light with different spectral distributions and emit illumination light with a composite spectral distribution obtained by combining the spectral distributions of the multiple light-emitting units; an acquisition unit that acquires environmental information representing the surrounding environment of the illumination area of ​​the headlight device; and a control unit that controls the spectral distribution of each of the multiple light-emitting units based on the environmental information acquired by the acquisition unit. The multiple light-emitting units include: a first light-emitting unit that emits a first light; and a second light-emitting unit that emits a second light with a center wavelength shorter than the center wavelength of the first light. The control unit calculates a glare level based on the environmental information, the glare level evaluating the glare applied to the driver of the vehicle when the illumination light is emitted. If the control unit determines that the glare level is above a predetermined glare threshold, it reduces the intensity of the second light.

[0014] The effects of the invention

[0015] According to this disclosure, a headlight device that improves the driver's visual recognition can be provided. Attached Figure Description

[0016] Figure 1 This is a block diagram illustrating the structure of the headlight device according to an embodiment.

[0017] Figure 2 (A) is shown Figure 1 A side view of the structure of the light source unit shown. Figure 2 (B) is shown Figure 1 The top view of the structure of the light source unit shown.

[0018] Figure 3 Figure (A) is a schematic diagram illustrating an example of the hardware structure of the control unit of the headlight device according to an embodiment. Figure 3 Figure (B) is a schematic diagram illustrating another example of the hardware structure of the control unit of the headlight device according to an embodiment.

[0019] Figure 4 It is a graph showing the spectral luminous efficiency curves for both light and dark visual environments.

[0020] Figure 5 Yes Figure 4 The chart shown is obtained by adding the spectral luminous efficiency curve of the intermediate visual environment.

[0021] Figure 6 This is a flowchart illustrating the operation of the headlight device according to an embodiment.

[0022] Figure 7 (A) to (D) show the sequence from Figure 1 and Figure 2 The diagram (A) shows the spectral distribution of light emitted by the multiple LEDs.

[0023] Figure 8 This is a diagram showing an example of the spectral distribution of the illumination light before control by the control unit.

[0024] Figure 9 This is a diagram showing an example of the spectral distribution of the illumination light after control by the control unit.

[0025] Figure 10 This is a block diagram illustrating the structure of a headlight device according to a modified embodiment.

[0026] Figure 11 This is a flowchart illustrating the operation of a headlight device according to a modified embodiment. Detailed Implementation

[0027] Hereinafter, the headlight device according to an embodiment of the present disclosure will be described with reference to the accompanying drawings. In the drawings, for ease of understanding, the coordinate axes of the XYZ orthogonal coordinate system are shown as needed. The X-axis is a coordinate axis parallel to the left-right direction of the vehicle. When facing forward of the vehicle, the right direction is the +X-axis direction, and the left direction is the -X-axis direction. Here, "forward" refers to the vehicle's direction of travel. In other words, "forward" is the direction of the headlight device's illumination light (hereinafter also referred to as "illumination light L1"). The Y-axis is a coordinate axis parallel to the up-down direction of the vehicle. The upward direction of the vehicle is the +Y-axis direction, and the downward direction of the vehicle is the -Y-axis direction. That is, the +Y-axis side of the vehicle is the sky side, and the -Y-axis side is the ground (i.e., road surface) side. The +Z-axis direction is the vehicle's direction of travel, and the -Z-axis direction is the direction opposite to the direction of travel. In the following description, the "+Z-axis direction" will be referred to as "forward," and the -Z-axis direction will be referred to as "rear." The +Z-axis direction is the direction of the headlight device's illumination light.

[0028] In the following explanation, the ZX plane is a plane parallel to the road surface. This is because, under normal circumstances, the road surface is considered a "horizontal plane." Therefore, the ZX plane is considered a "horizontal plane." A "horizontal plane" is a plane orthogonal to the direction of gravity. However, the road surface is sometimes inclined relative to the direction of vehicle travel. That is, the road surface is uphill or downhill, etc. In these cases, the "horizontal plane" is considered a plane parallel to the road surface. That is, the "horizontal plane" is not a plane perpendicular to the direction of gravity.

[0029] On the other hand, road surfaces rarely slope laterally relative to the direction of vehicle travel. "Left and right" refers to the width of the road surface (i.e., the direction of travel). In these cases, the "horizontal plane" is considered to be perpendicular to the direction of gravity. For example, if the road surface slopes laterally, even if the vehicle is perpendicular to the road surface in the left and right direction, it is considered equivalent to the vehicle being sloped laterally relative to the "horizontal plane."

[0030] Furthermore, to simplify the following explanation, the "horizontal plane" will be described as a plane perpendicular to the direction of gravity. That is, the ZX plane will be described as a plane perpendicular to the direction of gravity.

[0031] As the light source of this disclosure (hereinafter referred to as the "light-emitting part"), for example, a bulb light source such as an incandescent lamp, halogen lamp, or fluorescent lamp may be used. Furthermore, as the light source of this disclosure, a semiconductor light source such as an LED or laser diode may also be used. That is, the light source of this disclosure is not particularly limited, and any light source may be used.

[0032] However, from the viewpoint of ease of adjusting the spectral distribution of light emitted from a light source, a semiconductor light source is desirable as the light source for the headlight device of this disclosure. Compared to the use of conventional halogen lamps (light sources), the spectral distribution is easier to adjust when a semiconductor light source is used.

[0033] Therefore, in the following description of this disclosure, the light source is assumed to be an LED, which is one of the semiconductor light sources.

[0034] This disclosure is applied to low beam or high beam headlights. Furthermore, this disclosure is applied to low beam or high beam headlights for automatic two-wheeled vehicles. Additionally, this disclosure is also applied to other headlights for three-wheeled or four-wheeled vehicles.

[0035] <Structure of the headlight assembly>

[0036] Figure 1 This is a block diagram illustrating the structure of the headlight device 100 according to an embodiment. Figure 1As shown, the headlight device 100 includes a light source unit 10 as a headlight optical system, a surrounding environment information acquisition unit 20 as an acquisition unit, and a control unit 30.

[0037] <Light Source Section>

[0038] The light source unit 10 has a first LED 11, a second LED 12, a third LED 13, and a fourth LED 14 as multiple light-emitting parts. The first LED 11, the second LED 12, the third LED 13, and the fourth LED 14 emit light with different beam distributions. Thus, the light source unit 10 has two or more light-emitting surfaces that emit light with different beam distributions.

[0039] The light source 10 emits a composite beam distribution obtained by combining the beam distributions of the first LED 11, the second LED 12, the third LED 13, and the fourth LED 14 (for example, described later). Figure 8 and 9 The illumination light is distributed by the composite spectral distributions S1 and S2 shown. The light source unit 10 emits white light as illumination light, for example. By controlling the outputs of the first LED 11, the second LED 12, the third LED 13 and the fourth LED 14 respectively by the control unit 30 described later, the light source unit 10 can generate white light that is considered to have the same color temperature or the same chromaticity before and after control.

[0040] Figure 2 (A) is a side view showing the structure of the light source section 10. Figure 2 (B) is a top view showing the structure of the light source section 10. (See diagram below.) Figure 2 As shown in (A) and (B), the light source unit 10 also has a light guide 15. The light guide 15 uniformly mixes the light emitted from the first LED 11, the second LED 12, the third LED 13 and the fourth LED 14 respectively.

[0041] The light emitted from LED11, LED12, LED13, and LED14, after incident on the incident surface 15a of the light guide 15, undergoes repeated total internal reflection within the light guide 15, thus becoming uniform white light. This white light is then emitted from the exit surface 15b. Therefore, the illumination light L1 emitted from the headlight assembly 100 can illuminate the front as uniform white light without color inconsistencies.

[0042] Furthermore, since the light source unit 10 has a light guide 15, the headlight device 100 can be miniaturized.

[0043] Furthermore, the light guide 15 can be made of, for example, transparent resin, glass, or silicone. The material of the light guide 15 can be any material as long as it is transmissive, including transparent resin. However, from the viewpoint of light utilization efficiency, a material with high transmissivity is suitable for the light guide 15. In addition, since the light guide 15 is positioned immediately after the first LED 11, the second LED 12, the third LED 13, and the fourth LED 14, the material of the light guide 15 is preferably a material with excellent heat resistance.

[0044] exist Figure 1 , Figure 2 In the examples shown in (A) and (B), the light source unit 10 has a structure with 4 LEDs, but it is not limited to this. The light source unit 10 may have 2 or more LEDs with different spectral distributions.

[0045] Furthermore, the light source unit 10 can be implemented even without the light guide 15. For example, the light source unit 10 can also generate uniform white light using other optical components different from the light guide 15.

[0046] <Surrounding Environment Information Acquisition Department>

[0047] Return to Figure 1 The surrounding environment information acquisition unit 20 and the control unit 30 will be described below. The surrounding environment information acquisition unit 20 acquires environmental information (hereinafter also referred to as "surrounding environment information") representing the surrounding environment of the illumination area of ​​the headlight device 100. The surrounding environment information acquisition unit 20 acquires information used to quantitatively evaluate glare intensity as surrounding environment information, which represents the degree of glare exerted on the driver by a vehicle equipped with the headlight device 100 when illumination light L1 is emitted from the headlight device 100. The surrounding environment information may include, for example, weather information indicating the weather conditions. The weather information includes at least one of rain, snow, and fog. Furthermore, the surrounding environment information is not limited to weather information; it may also include brightness information indicating the brightness of the surrounding environment of the illumination area of ​​the headlight device 100. In addition, the surrounding environment information may also include traffic information indicating the traffic volume of other vehicles. Furthermore, as described later, the surrounding environment information may also include ambient light information, which represents information about the return light after reflection or scattering of illumination light L1 emitted from the headlight device 100 in the illumination area.

[0048] Thus, the ambient environment information acquisition unit 20 is an information input unit that receives sensor information such as weather information, brightness information, traffic information, and ambient light information. The ambient environment information acquisition unit 20 can acquire this sensor information from sensors installed in the vehicle, or it can acquire this sensor information by communicating with information sources outside the vehicle.

[0049] Control Department

[0050] The control unit 30 controls the beam distribution of the first LED 11, the second LED 12, the third LED 13, and the fourth LED 14 based on the ambient environment information acquired by the ambient environment information acquisition unit 20 (for example, as described later). Figure 7 The light distributions shown are S11, S12, S13, and S14. The control unit 30 includes a headlamp control module 31 and a light source control unit 32.

[0051] The headlight control module 31 calculates the glare amount based on ambient environment information to evaluate the glare applied to the driver when illumination light L1 is applied, and determines whether the calculated glare amount meets predetermined conditions. For example, the headlight control module 31 determines whether the calculated glare amount is above a predetermined glare threshold. Based on the result of this determination, the headlight control module 31 generates control signals for controlling the output (i.e., intensity) of the light L11, L12, L13, and L14 emitted from the first LED 11, second LED 12, third LED 13, and fourth LED 14, respectively. The headlight control module 31 outputs the generated control signals to the light source control unit 32. Thus, the headlight control module 31 is a control signal generation unit that generates control signals.

[0052] The light source control unit 32 is a light source driving unit that drives the light source unit 10. Based on the control signals generated by the headlight control module 31, the light source control unit 32 drives the first LED 11, the second LED 12, the third LED 13, and the fourth LED 14 respectively. Figure 1 In the example shown, the light source control unit 32 and the light source unit 10 are disposed in the headlight module 50 of the headlight device 100.

[0053] Figure 3 (A) is a diagram that schematically shows the hardware structure of the control unit 30. (See diagram for example.) Figure 3 As shown in (A), the control unit 30 can be implemented, for example, using a memory 30a, which stores a program as software, and a processor 30b, which is an information processing unit that executes the program stored in the memory 30a (e.g., a computer). Additionally, a portion of the control unit 30, namely a portion of the headlamp control module 31 and the light source control unit 32, can also be implemented using... Figure 3 The memory 30a and the processor 30b that executes the program, as shown in (A), are implemented. Furthermore, the control unit 30 can also be implemented by electrical circuitry.

[0054] Figure 3 Figure (B) is another example of a schematic diagram showing the hardware structure of the control unit 30. Figure 3As shown in (B), the control unit 30 can also be implemented using a dedicated hardware processing circuit 30c, such as a single circuit or a composite circuit. In this case, the function of the control unit 30 is implemented by the processing circuit 30c.

[0055] The Relationship Between the Purkinje Phenomenon and Glare

[0056] Here, the Purkinje phenomenon is known as the cause of glare to drivers from vehicles equipped with headlights. The Purkinje phenomenon refers to the shift of the peak of the spectral luminous efficacy curve towards shorter wavelengths relative to light vision in dark vision environments.

[0057] Figure 4 This is a graph showing the spectral luminous efficiency curve V1 for light vision and V2 for dark vision. Figure 4 In the chart shown, the horizontal axis represents wavelength λ (nm), and the vertical axis represents spectral luminous efficacy. Furthermore, in Figure 4 In the diagram, the solid line represents the spectral luminous efficiency curve V1 for photopic vision, and the dashed line represents the spectral luminous efficiency curve V2 for scotopic vision. For example... Figure 4 As shown, the wavelength at the peak of the spectral luminous efficacy curve V2 is shorter than the wavelength at the peak of the spectral luminous efficacy curve V1 (i.e., ...). Figure 4 (The direction of the arrow shown is deflected.) For example, in a bright photopic environment like daytime, the human eye perceives light with a wavelength of approximately 555 nm as the brightest. On the other hand, in a scotopic environment, the human eye perceives light with a wavelength of approximately 507 nm as the brightest. Here, the illumination environment of a headlight device at night is the brightness environment known as the "intermediate visual environment," which lies between the photopic and scotopic environments.

[0058] Figure 5 Yes Figure 4 The chart shown is obtained by appending the spectral luminous efficiency curve V3 of the intermediate visual environment. For example... Figure 5 As shown, the peak of the spectral luminous efficacy curve V3 has a wavelength between 507 nm and 555 nm. Therefore, when illumination from the headlight device is provided with light with a wavelength between 507 nm and 555 nm, the driver's eyes will perceive the light as brightest. On the other hand, if the amount of illumination light with a wavelength between 507 nm and 555 nm is increased to a level exceeding the desired amount, the driver is more likely to experience glare.

[0059] For example, in inclement weather such as rain or snow, when headlights illuminate the driver's eyes, the light may be scattered by raindrops or snow and reflected back into the driver's eyes. In this situation, the driver experiences glare. Furthermore, as mentioned above, the more short-wavelength components (wavelengths below 555 nm) the headlights contain, the stronger the glare will be perceived by the driver.

[0060] Operation of the headlight assembly

[0061] In the headlight device 100 of the embodiment, the beam distribution of the illumination light L1 emitted from the light source unit 10 is adjusted based on the ambient environment information obtained by the ambient environment information acquisition unit 20, thereby suppressing glare applied to the driver. Figure 6 This is a flowchart illustrating the operation of the headlight device 100.

[0062] First, in step ST1, the control unit 30 starts a loop process after startup, repeating steps ST2 to ST6.

[0063] In step ST2, a signal representing the surrounding environment information obtained by the surrounding environment information acquisition unit 20 is input to the headlight control module 31 of the control unit 30.

[0064] In step ST3, the headlight control module 31 determines whether the surrounding environment information meets the conditions for increasing glare applied to the driver (hereinafter also referred to as the "glare increase condition"). If the surrounding environment information meets the glare increase condition (i.e., the condition is determined to be "yes" in step ST3), the process proceeds to step ST4. For example, the headlight control module 31 proceeds to step ST4 when the weather is rainy, snowy, or foggy.

[0065] On the other hand, if the headlight control module 31 determines that the surrounding environment information does not meet the conditions for increasing glare (that is, in step ST3, if the determination is "no"), the processing will proceed to step ST5.

[0066] In step ST4, the headlamp control module 31 generates a control signal that relatively reduces the short-wavelength component (those shorter than the wavelength at the representative point) in the spectral distribution of the illumination light L1. Figure 1 Based on this control signal, the light source control unit 32 reduces the intensity of the shorter-wavelength light in the light emitted from LEDs L11, L12, L13, and L14 respectively. This suppresses glare to the driver. Therefore, the headlight device 100 improves the driver's visual visibility.

[0067] In step ST5, the headlight control module 31 determines whether the surrounding environment information meets the conditions for reducing glare applied to the driver (hereinafter also referred to as the "glare reduction condition"). If the surrounding environment information meets the glare reduction condition (i.e., if it is determined to be "yes" in step ST5), the process proceeds to step ST6.

[0068] In step ST6, the headlamp control module 31 generates a control signal that relatively increases the short-wavelength component in the spectral distribution of the illumination light L1. Figure 1 Based on the control signal, the light source control unit 32 amplifies the intensity of the shorter-wavelength light in the light emitted from LEDs 11, 2, 3, and 4 respectively (L11, L12, L13, L14). As a result, in the intermediate visual environment, the headlight device 100 illuminates the light L1 with an increased spectral distribution of short-wavelength components, making the driver perceive the illumination light L1 as bright. Therefore, the headlight device 100 improves the driver's visual recognition.

[0069] If the result in step ST5 is "No", or after the processing in step ST4 or ST6 is completed, repeat steps ST2 to ST6 until the condition for the end of the loop processing is met.

[0070] <Design Example>

[0071] Next, a design example of the spectral distribution of the illumination light L1 using specific numerical examples will be explained. The following will use... Figure 1 and Figure 2 The following explanation uses the case shown in Table 1 where the center wavelengths (also called "dominant wavelengths") of LED11, LED12, LED13, and LED14 are the values ​​shown in Table 1. In the example shown in Table 1, the center wavelengths of LED11 and LED12 are shorter than the center wavelengths of LED13 and LED14. In the following explanation, LED13 and LED14 will also be referred to as "first light-emitting units," and LED11 and LED12 will also be referred to as "second light-emitting units." The second light-emitting unit emits light with a center wavelength shorter than the first light emitted by the first light-emitting unit (i.e., Figure 2 The light shown in (A) (L13, L14) has a shorter center wavelength (i.e., Figure 2 (A) shows light L11, L12.

[0072] [Table 1]

[0073]

[0074]

[0075] Figure 7 (A) to (D) show the sequence from Figure 1 and Figure 2 The diagram (A) shows the spectral distributions S11, S12, S13, S14 of the light emitted from LED11, LED12, LED13, and LED14, respectively. Figure 7 In the graphs shown in (A) to (D), the horizontal axis represents wavelength λ (nm), and the vertical axis represents specific energy (au). Figure 7 As shown in (A) to (D), the spectroscopic distributions S11, S12, S13, and S14 have peaks at the center wavelengths shown in Table 1.

[0076] Here, the composite spectral distribution of the illumination light L1 before control is defined as S1, and the composite spectral distribution of the illumination light L1 after control is defined as S2. As described above, when the surrounding environmental information satisfies the condition of increased glare, the headlamp control module 31 (refer to...) Figure 1 The headlamp control module 31 controls the illumination light L1 by relatively reducing the short-wavelength components (e.g., the portion between 450 nm and 550 nm in the spectral distribution). Specifically, the headlamp control module 31 generates control signals such that the composite spectral distribution S1 and composite spectral distribution S2 satisfy the following equation (1). The headlamp control module 31 reduces the intensity of the second light emitted by the second light-emitting unit (i.e., at least one of the first LED 11 and the second LED 12) to satisfy equation (1).

[0077] [Formula 1]

[0078]

[0079] When the combined spectral distributions S1 and S2 satisfy equation (1), the components with wavelengths below 550 nm in the spectral distribution of the illumination light L1 emitted from the light source section 10 are reduced. That is, the presence of peaks with wavelengths below 550 nm in the spectral distribution of the illumination light L1 is suppressed. As a result, the increase in glare caused by the Purkinje phenomenon can be suppressed.

[0080] Figure 8 This is a diagram showing an example of the composite spectral distribution S1 of the illumination light L1 before control. Figure 9 This is a diagram illustrating an example of the composite spectral distribution S2 of the controlled illumination light L1. Figure 8 and Figure 9 In the chart shown, the horizontal axis represents wavelength λ (nm), and the vertical axis represents specific energy (au). Figure 8 The synthesized spectroscopic distribution S1 shown is achieved by controlling... Figure 1 and Figure 2 The beam distribution is obtained by analyzing the outputs of LED11, LED12 and LED14 as shown in (A).

[0081] Figure 9 The synthesized spectroscopic distribution S2 shown is achieved by controlling... Figure 1 and Figure 2 The beam distribution is obtained by analyzing the outputs of LED11, LED13 and LED14 as shown in (A).

[0082] The value on the left side of equation (1) is 0.467, and the value on the right side of equation (1) is 0.377. In this case, equation (1) is satisfied, and therefore, glare applied to the driver can be suppressed.

[0083] In this embodiment, the color of the illumination light L1 from the composite spectral distribution S1 is the same as the color of the illumination light L1 from the composite spectral distribution S2. In other words, the control unit 30 controls the spectral distributions S11, S12, S13, and S14 so that the color temperature of the illumination light L1 from the composite spectral distribution S2 is within a predetermined range. Furthermore, by changing the color of the illumination light L1 emitted from the headlight device 100, it is possible to prevent the driver from misjudging distance.

[0084] In this embodiment, the color of the illumination light L1 is white. Here, when the color temperature of the illumination light L1 of the composite spectral distribution S1 is set to K1 (unit: K) and the color temperature of the illumination light L1 of the composite spectral distribution S2 is set to K2 (unit: K), the color temperatures K1 and K2 are expected to satisfy the following equation (2).

[0085] K1-500≤K2≤K1+500 (2)

[0086] With the center wavelengths of LED11, LED12, LED13, and LED14 respectively being the values ​​shown in Table 1, the color temperature K1 is 5579K and the color temperature K2 is 5511K. In this case, since the color temperatures K1 and K2 satisfy equation (2), the color of the illumination light L1 of the composite spectral distribution S1 can be considered to be the same color as the color of the illumination light L1 of the composite spectral distribution S2.

[0087] Therefore, in this embodiment, before and after the control unit 30 controls the beam distribution S11, S12, S13, and S14, the color of the illumination light L1 emitted from the light source unit 10 does not change. This prevents the driver from misjudging distance and suppresses glare. Furthermore, regulations stipulate that the color of the illumination light L1 emitted from the headlight device 100 should not change.

[0088] <Effect>

[0089] According to the embodiment described above, the control unit 30 controls the beam distributions S11, S12, S13, and S14 of the first LED 11, the second LED 12, the third LED 13, and the fourth LED 14 based on the ambient environment information acquired by the ambient environment information acquisition unit 20. Therefore, by appropriately adjusting the beam distribution of the illumination light L1 emitted from the headlight device 100 according to the ambient environment information, glare to the driver can be suppressed. This improves the driver's visual recognition.

[0090] Furthermore, according to the embodiment, the control unit 30 controls the beam distributions S11, S12, S13, and S14 so that the color temperature of the illumination light L1 is within a predetermined range before and after controlling the beam distributions S11, S12, S13, and S14 of the first LED 11, second LED 12, third LED 13, and fourth LED 14, respectively. Therefore, the color of the illumination light L1 emitted from the light source unit 10 does not change before and after the control unit 30 controls the beam distributions S11, S12, S13, and S14, thus preventing the driver from misjudging distance.

[0091] Variations in the implementation method

[0092] Figure 10 This is a block diagram illustrating the structure of a modified example of a headlight device 100A according to an embodiment. Figure 10 In China, targeting and Figure 1 Structural elements that are the same as or correspond to the structural elements shown are labeled with the same structural elements. Figure 1 The same reference numerals are shown. The headlight device 100A of the modified embodiment differs from the headlight device 100 of the embodiment in that it includes a light-receiving unit 21 in the ambient environment information acquisition unit 20A. Apart from this, the headlight device 100A of the modified embodiment is the same as the headlight device 100 of the embodiment. Therefore, reference will be made to the following description. Figure 2 (A)

[0093] like Figure 10 As shown, the headlight device 100A includes a light source unit 10, a surrounding environment information acquisition unit 20A, and a control unit 30.

[0094] The ambient environment information acquisition unit 20A has a light receiving unit 21. The light receiving unit 21 receives illumination light L1 (see reference) emanating from the headlight device 100A. Figure 2 The reflected light (A) is the light that is reflected or scattered in the illuminated area. Thus, the reflected light is, for example, reflected light, scattered light, etc. The reflected light is the ambient light generated in the surrounding environment of the illuminated area of ​​the headlight device 100A.

[0095] The headlight control module 31 of the control unit 30 generates a control signal that is output to the light source control unit 32 based on the detection signal corresponding to the return light received in the light receiving unit 21.

[0096] The detection signal output from the light-receiving unit 21 is, for example, a signal corresponding to the amount of light received by the return light detected in the light-receiving unit 21. The headlight control module 31 generates, for example, a control signal to reduce glare to the driver when the headlight L1 is illuminated, based on the signal corresponding to the amount of light received by the return light. As a result, glare to the driver when the headlight L1 is illuminated by the headlight device 100A can be suppressed.

[0097] <Operation of the headlight device in a modified example>

[0098] Next, the operation of the headlight device 100A in a modified embodiment will be explained. Figure 11 This is a flowchart illustrating the operation of the headlight device 100A, a modified example of the embodiment.

[0099] First, in step ST11, after the control unit 30 is started, it begins to perform a cyclical process that repeats steps ST12 to ST16.

[0100] In step ST12, a signal corresponding to the amount of light received by the return light obtained by the ambient environment information acquisition unit 20A is input to the headlight control module 31 of the control unit 30.

[0101] In step ST13, the headlight control module 31 determines whether the amount of light received by the returned light meets the condition for increased glare. If the amount of light received meets the condition for increased glare (i.e., if the condition is "yes" in step ST13), the process proceeds to step ST14. Specifically, in step ST13, the headlight control module 31 determines whether the amount of light received by the returned light is above a predetermined first threshold Th1. If the condition is "yes", the process proceeds to step ST14.

[0102] On the other hand, if the headlight control module 31 determines that the amount of light received by the returned light does not meet the conditions for increased glare (that is, in step ST13, the amount of light received is less than the first threshold Th1, so it is determined to be "no"), the process proceeds to step ST15.

[0103] In step ST14, the headlamp control module 31 controls the light to relatively reduce the short-wavelength components in the spectral distribution of the illumination light L1 emitted from the light source unit 10. Step ST14 and Figure 6 The steps shown in ST4 are the same. For example, the headlight control module 31 generates a control signal that makes the value t shown in equation (3) below smaller than a predetermined threshold.

[0104] [Formula 2]

[0105]

[0106] In step ST15, the headlight control module 31 determines whether the amount of light received by the returned light meets the condition for glare reduction. If the amount of light received meets the condition for glare reduction (i.e., if the determination is "yes" in step ST15), the process proceeds to step ST16. Specifically, in step ST15, the headlight control module 31 determines whether the amount of light received by the returned light is less than a second threshold Th2, which is less than a first threshold Th1. If the determination is "yes", the process proceeds to step ST16.

[0107] Step ST16 and Figure 6 The steps shown are the same as ST6. For example, the headlight control module 31 generates a control signal that makes the value t shown in equation (3) above greater than the threshold.

[0108] If the result in step ST15 is "No", or after the processing in step ST14 or ST16 is completed, repeat steps ST12 to ST16 until the condition for the end of the loop processing is met.

[0109] <The effect of the variation>

[0110] According to a variation of the embodiment described above, the ambient environment information acquisition unit 20A has a light-receiving unit 21 that receives light reflected or scattered by the illumination light L1 in the illuminated area, i.e., reflected light. When it is determined that the amount of reflected light is above a predetermined first threshold Th1, control is performed to reduce the intensity of light emitted from a second light-emitting unit (e.g., the second LED 12) with a short center wavelength. Thus, illumination light L1 with an appropriate spectral distribution corresponding to the amount of reflected light is emitted. Therefore, glare to the driver is suppressed, and the headlight device 100A can improve the driver's visual recognition.

[0111] Furthermore, in the above embodiments, terms such as "parallel" and "perpendicular" are sometimes used to describe the positional relationship between components or the shape of the components. These indicate a range that takes into account manufacturing tolerances and assembly deviations. Therefore, when the claims describe the positional relationship between components or the shape of the components, it indicates that a range that takes into account manufacturing tolerances or assembly deviations is included.

[0112] Furthermore, the above-described embodiments are merely examples, and various modifications can be made within the scope of this disclosure.

[0113] Explanation of reference numerals in the attached figures

[0114] 10 Light source unit, 11 First LED, 12 Second LED, 13 Third LED, 14 Fourth LED, 15 Light guide, 20, 20A Ambient environment information acquisition unit, 21 Light receiving unit, 30 Control unit, 30a Memory, 30b Processor, 30c Processing circuit, 31 Headlamp control module, 32 Light source control unit, 50 Headlamp module, 100, 100A Headlamp device, L1 Illumination light, L11, L12, L13, L14 light, S1, S2 Combined spectral distribution, S11, S12, S13, S14 spectral distribution, Th1 First threshold, Th2 Second threshold.

Claims

1. A headlight device, which is a headlight device for a vehicle, characterized in that, have: The light source has multiple light-emitting units that emit light with different spectral distributions, and emits illumination light with a composite spectral distribution, which is obtained by combining the spectral distributions of the multiple light-emitting units. The acquisition unit acquires environmental information representing the surrounding environment of the illumination area of ​​the headlight device; and The control unit controls the spectral distribution of each of the plurality of light-emitting units based on the environmental information acquired by the acquisition unit. The plurality of light-emitting parts have: The first light-emitting part emits the first light; and The second light-emitting part emits a second light with a center wavelength shorter than the center wavelength of the first light. The control unit calculates glare level based on the environmental information. This glare level evaluates the glare applied to the driver of the vehicle when the illumination light is emitted. If the control unit determines that the glare amount is above a predetermined glare threshold, it reduces the intensity of the second light.

2. The headlight device according to claim 1, characterized in that, The acquiring unit has a light-receiving unit that receives reflected light, which is the light after the illumination light has been reflected or scattered in the illumination area. If the control unit determines that the amount of light received by the returned light, which is the amount of glare, is above a predetermined first threshold, the control unit reduces the intensity of the second light.

3. The headlight device according to claim 2, characterized in that, When the control unit determines that the amount of light received by the returned light is less than or equal to a second threshold which is less than the first threshold, it increases the intensity of the second light.

4. The headlight device according to any one of claims 1 to 3, characterized in that, The control unit controls the spectral distribution so that the color temperature of the illumination light is within a predetermined range before and after controlling the spectral distribution of each of the plurality of light-emitting units.

5. The headlight device according to any one of claims 1 to 3, characterized in that, The environmental information includes weather information indicating the weather conditions.

6. The headlight device according to claim 4, characterized in that, The environmental information includes weather information indicating the weather conditions.

7. A headlight device for vehicles, characterized in that, have: The light source has multiple light-emitting units that emit light with different spectral distributions, and emits illumination light with a composite spectral distribution, which is obtained by combining the spectral distributions of the multiple light-emitting units. The acquisition unit acquires environmental information representing the surrounding environment of the illumination area of ​​the headlight device; and The control unit controls the spectral distribution of each of the plurality of light-emitting units based on the environmental information acquired by the acquisition unit. The plurality of light-emitting parts have: The first light-emitting part emits the first light; and The second light-emitting part emits a second light with a center wavelength shorter than the center wavelength of the first light. The control unit controls the spectral distribution based on the environmental information, such that the relationship between the color temperature K1 of the illumination light of the composite spectral distribution before controlling the spectral distribution of each of the plurality of light-emitting units and the color temperature K2 of the illumination light of the composite spectral distribution after controlling the spectral distribution of each of the plurality of light-emitting units satisfies the following formula in Kelvin. K1-500≤K2≤K1+500.

8. The headlight device according to claim 7, characterized in that, The environmental information includes weather information indicating the weather conditions.

9. A headlight device, which is a headlight device for a vehicle, characterized in that, have: The light source has multiple light-emitting units that emit light with different spectral distributions, and emits illumination light with a composite spectral distribution, which is obtained by combining the spectral distributions of the multiple light-emitting units. The acquisition unit acquires environmental information representing the surrounding environment of the illumination area of ​​the headlight device; and The control unit controls the spectral distribution of each of the plurality of light-emitting units based on the environmental information acquired by the acquisition unit. The plurality of light-emitting parts have: The first light-emitting part emits the first light; and The second light-emitting part emits a second light with a center wavelength shorter than the center wavelength of the first light. The control unit calculates glare level based on the environmental information. This glare level evaluates the glare applied to the driver of the vehicle when the illumination light is emitted. When the control unit determines that the glare amount is above a predetermined glare threshold, it controls the spectral distribution so that the integral value of the intensity of the component between 450nm and 550nm in the composite spectral distribution of the multiple light-emitting units is relatively reduced.

10. The headlight device according to claim 9, characterized in that, When the control unit determines that the glare amount is above a predetermined glare threshold, it controls the spectral distribution to reduce the second value compared to the first value. The first value is the ratio of the integral value of the intensity of the component between wavelengths 450nm and 550nm in the synthesized spectral distribution before controlling the spectral distribution to the integral value of the intensity of the component between wavelengths 400nm and 700nm in the synthesized spectral distribution before controlling the spectral distribution. The second value is the ratio of the integral value of the intensity of the component between wavelengths 450nm and 550nm in the synthesized spectral distribution after controlling the spectral distribution to the integral value of the intensity of the component between wavelengths 400nm and 700nm in the synthesized spectral distribution after controlling the spectral distribution.

11. The headlight device according to claim 9, characterized in that, When the control unit determines that the glare amount is above a predetermined glare threshold, it controls the spectral distribution so that the integral value of the intensity of the component between wavelengths 450nm and 550nm in the composite spectral distribution is less than the integral value of the intensity of the component between wavelengths 400nm and 700nm in the composite spectral distribution.

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