Vehicle lamp

Abstract

A vehicle lamp (1) includes: a light source portion (20); a unit lens (30) having a main surface (31s) as a unit region through which light L emitted from the light source portion (20) is transmitted, and arranged with a plurality of units (33) including nanostructures (35) smaller than the longest wavelength of the light L emitted from the light source portion (20); and the main surface (31s) as the unit region changes a phase distribution of the light (L) transmitted through the main surface (31s).

Description

Technical Field

[0001] This invention relates to a vehicle lamp. Background Technology

[0002] As vehicle lighting fixtures, such as automotive headlights, vehicle lighting fixtures with projection lenses that allow light emitted from the light source to pass through are known. For example, such a vehicle lighting fixture is disclosed in Patent Document 1 below.

[0003] In the vehicle lamp of Patent Document 1 described below, the divergence angle of the light emitted from the light source and incident on the projection lens is adjusted, and the light is directed to the front of the vehicle.

[0004] Furthermore, for example, Patent Document 2 disclosed below discloses a vehicle lamp with an expanded light distribution pattern. In this vehicle lamp, an auxiliary lens is disposed near the front of the peripheral portion of the projection lens. The auxiliary lens deflects the light transmitted through the projection lens in a direction that departs from the horizontal direction of the optical axis. As a result, the light distribution pattern projected from the vehicle lamp to the outside becomes a light distribution pattern that expands to the left and right sides from both ends of the light distribution pattern projected from the vehicle lamp to the outside without the auxiliary lens, thus expanding compared to the light distribution pattern without the auxiliary lens.

[0005] Furthermore, a vehicle lamp is known whose light source section is composed of a light-emitting module including a semiconductor light-emitting element such as an LED (Light Emitting Diode). Various structures have been investigated to make the light emitted from such a light-emitting module a desired color. For example, Patent Document 3 discloses a light-emitting module comprising an LED and a phosphor, wherein the phosphor irradiates a portion of the light emitted from the LED to emit light of a different wavelength. In this light-emitting module, the light emitted from the phosphor combines with another portion of the light emitted from the LED to emit light of a different color than the light emitted from the LED. Furthermore, the spectral distribution of the light emitted from this light-emitting module includes two peaks, one with a wavelength approximately the same as the peak wavelength of the light emitted from the LED, and the other with a wavelength approximately the same as the peak wavelength of the light emitted from the phosphor.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2012-169189

[0009] Patent Document 2: Japanese Patent Application Publication No. 2007-35467

[0010] Patent Document 3: Japanese Patent Application Publication No. 10-242513 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] In vehicle lamps like those described in Patent Document 1, it is easy to make the size of the emitted light distribution pattern as desired. However, due to the diversification of vehicle designs, there is a demand for miniaturization of vehicle lamps.

[0013] Therefore, the object of the present invention is to provide a vehicle lamp that can be miniaturized.

[0014] To achieve the above objectives, the vehicle lamp of the present invention is characterized by comprising: a light source; a primary lens having a plurality of units arranged including nanostructures smaller than the longest wavelength of light emitted from the light source and having a primary region through which the light emitted from the light source is transmitted; the primary region causing a change in the phase distribution of the light transmitted through the primary region.

[0015] In projection lenses for vehicle lighting, at least one of the incident surface and the exit surface is typically curved, and the divergence angle of light emitted from the light source is adjusted by changing the shape of this curved surface. Therefore, in such projection lenses, a certain thickness is required to form the curved surface. On the other hand, the element lens in this vehicle lighting fixture can adjust the divergence angle of light by changing the phase distribution of light from the light source through adjusting the arrangement of multiple units or the size of nanostructures in each unit. Therefore, even if the curvature of the element region is smaller than that of the projection lens surface, the element lens can still adjust the divergence angle of light from the light source and can be thinner than the projection lens. Therefore, according to this vehicle lighting fixture, miniaturization can be achieved compared to the case where the divergence angle of light from the light source is adjusted using a projection lens.

[0016] The incident surface of the element lens for the light from the light source can also be such that the light is refracted by bending outward in a convex shape, thereby reducing the divergence angle of the light, and the light incident on the incident surface passes through the element region.

[0017] Generally, if the divergence angle of the light incident on the element region increases, the design of the element region tends to become more complex. In the element lens of this vehicle lamp, light from the light source enters the element region after its divergence angle is reduced by passing through a curved incident surface. Therefore, for example, when the divergence angle of the light from the light source is reduced to a predetermined divergence angle by the element lens, the divergence angle of the light incident on the element region can be reduced compared to the case where the incident surface for the light from the light source is flat. Therefore, according to this vehicle lamp, the design of the element region can be prevented from becoming complex, which is particularly useful in reducing the divergence angle of the light from the light source.

[0018] Alternatively, the incident surface of the element lens for the light from the light source may be provided with multiple slots to diffract the light in a way that reduces the divergence angle, so that the light incident on the incident surface passes through the element region.

[0019] In the element lens of this vehicle lamp, light from the light source is incident on the element region after its divergence angle is reduced by passing through the incident surface. Therefore, for example, when the divergence angle of the light from the light source is reduced to a predetermined divergence angle by the element lens, the divergence angle of the light incident on the element region can be reduced compared to the case where the incident surface for the light from the light source is a plane. Therefore, according to this vehicle lamp, it is possible to prevent the design of the element region from becoming complicated, which is particularly useful in reducing the divergence angle of the light from the light source.

[0020] The aforementioned vehicle lights may also include a protective component that is light-transmitting and covers the element area.

[0021] By adopting such a structure, it is possible to suppress the entry of dust and other particles between the nanostructures, or the adhesion of dust and other particles to the nanostructures, or the damage to the nanostructures, and the divergence angle of the light from the light source can be appropriately adjusted.

[0022] In this case, the protective component may also have a lower refractive index than the element lens and fill the spaces between the individual nanostructures.

[0023] Alternatively, when a reference light parallel to a reference axis orthogonal to the element region is incident on the element region at a specific position within the element region, the phase distribution of the reference light emitted from the element lens is changed in such a way that the phase distribution is formed by the remainder after dividing a predetermined phase distribution by 2π. The predetermined phase distribution is a phase distribution in which the phase retardation (rad) decreases as it moves away from the reference axis and the rate of decrease of the phase retardation increases. The specific phase distribution has multiple peaks, and when viewed along the reference axis, the multiple units are arranged such that there are two or more units between adjacent peaks in the direction away from the specific position.

[0024] By constructing the element region in such a manner that the phase distribution of the reference light is the aforementioned predetermined phase distribution, the divergence angle of light emitted from the element lens through the element region can be reduced. Here, when the phase delay of the light is an integer multiple of 2π, it can be considered that the wavefront of the light is the same as the wavefront of light without phase delay. Therefore, even if the element region is constructed in such a manner that the phase distribution of the reference light is the aforementioned specific phase distribution, the divergence angle can be reduced. Therefore, this vehicle lamp can reduce the divergence angle of light from the light source using the element lens. In addition, as described above, the specific phase distribution is composed of the remainder obtained by dividing a predetermined phase distribution, which increases with the amount of phase delay as it moves away from the element region from a specific position and the rate of increase of that phase delay, by 2π, and has multiple peaks. Therefore, the amount of phase delay in the specific phase distribution increases from zero as it moves away from the specific position, and infinitely approaches 2π, periodically repeating the change to zero. The fewer the number of units configured in one cycle relative to the aforementioned variation, the greater the deviation between the phase distribution varying according to the element region and the specific phase distribution. Consequently, the energy of light emitted from the element region at a divergence angle corresponding to the specific phase distribution tends to decrease relative to the energy of light incident on the element region. In this vehicle lamp, two or more units are configured in one cycle relative to this variation. By configuring the units in this way, the energy loss of light caused by the element lens can be easily reduced to a level suitable for use in vehicle lamps.

[0025] When multiple units are arranged as described above, the specific phase distribution may have more than three peaks, and the number of units located between the peaks may decrease as they move away from the specific location.

[0026] Furthermore, when multiple units are arranged as described above, preferably, the nanostructure is cylindrical in shape, and the number of units located between the peaks is three or more. The inventors have discovered that by employing such a structure, the energy of light emitted from the meta-region at a divergence angle corresponding to a specific phase distribution can be at least 60% of the energy of light incident on the meta-region.

[0027] The minimum width of the meta-region can also be 10mm or more.

[0028] Generally, increasing the size of the lens can easily increase the amount of light emitted from it. By employing the above structure, it is easy to make the light distribution pattern of the light emitted from the lens achieve the brightness required for the light distribution pattern of a vehicle headlight. It should be noted that the light distribution pattern for the light emitted from a vehicle headlight can, for example, be the light distribution pattern for low beam or high beam.

[0029] In addition, the meta-region can also change the phase distribution of the light transmitted through the meta-region in a way that produces coma aberration, thereby expanding the divergence angle of the light transmitted through the meta-region in the left-right direction of the light distribution pattern formed by the light compared to the case where no coma aberration is produced.

[0030] Coma aberration refers to the aberration where a point image on the image plane does not converge to a single point but extends like a comet's tail. On the image plane, light does not radiate outwards from the point image due to coma aberration; instead, it extends in a certain direction. Therefore, it can be understood that the divergence angle of light is extended due to coma aberration. In a meta-lens, even without coma aberration, the divergence angle of light can be extended by adjusting the arrangement of multiple units, the size and shape of the nanostructures in each unit, etc. However, in the meta-region of this invention, even with the same divergence angle as that extended without coma aberration, the divergence angle can be further extended in the left-right direction due to the aforementioned extension of light caused by coma aberration. Therefore, compared to a light distribution pattern projected from the meta-lens that extends the divergence angle without coma aberration, the light distribution pattern can be further extended in the left-right direction.

[0031] Furthermore, projection lenses with curved surfaces, as described above, are typically designed to suppress coma. Therefore, when using a projection lens, the expansion of the divergence angle of light from the light source is suppressed, as is the expansion of the light distribution pattern projected onto the exterior of the vehicle lamp. In contrast, in the elemental region of the elemental lens constructed as a projection lens, the divergence angle expands due to coma, thus the light distribution pattern can be expanded compared to the light distribution pattern projected from the projection lens.

[0032] Furthermore, when the phase distribution of light transmitted through the meta-region changes in a way that produces coma, the meta-region can also ensure that the expansion of the divergence angle extending to the left due to the coma is the same as the expansion of the divergence angle extending to the right due to the coma. With this structure, the expansion amounts at the right and left ends of the light distribution pattern can be the same, making the design of the meta-lens easier compared to cases where the expansion amounts are not the same.

[0033] Alternatively, the meta-region may also have one of the expansion amounts of the divergence angle extending to the left due to the coma and the expansion amounts of the divergence angle extending to the right due to the coma being greater than the other. With such a structure, the diffusion amount at the right end of the light distribution pattern and the diffusion amount at the left end of the light distribution pattern are greater than the other, making it easier for the vehicle driver to visually identify objects located on the side of the light distribution pattern diffusion.

[0034] Furthermore, when the phase distribution of light transmitted through the meta-region changes in a way that produces coma, compared to the case where no coma is produced, the meta-region can also extend the divergence angle of the light transmitted through the meta-region in the vertical direction of the light distribution pattern formed by the light. By adopting such a structure, the driver of a vehicle can easily visually identify objects such as guide signs and road surfaces.

[0035] Furthermore, when the phase distribution of light transmitted through the meta-region changes in a way that produces coma, the meta-region can also cause the expansion of the divergence angle in the left-right direction due to the coma to be greater than the expansion of the divergence angle in the up-down direction due to the coma. With this structure, the amount of light transmitted through the meta-lens remains constant, and the light distribution pattern expands much more in the left-right direction than in the up-down direction. The driver's field of vision is thus more ensured in the left-right direction than in the up-down direction through this light distribution pattern.

[0036] In addition, the curvature of the element region can be such that the infrared light contained in the light transmitted through the element region bends less than the curvature of the element region containing the visible light transmitted through the element region.

[0037] As described above, the meta-regions alter the phase distribution of light transmitted through them. This phase distribution varies depending on the arrangement of the multiple units, the size and shape of the nanostructures within each unit, and so on. Therefore, by adjusting these units, the meta-regions alter the phase distribution of light transmitted through them, resulting in a smaller curvature in the meta-regions that bends the infrared light contained in the transmitted light compared to the curvature in the meta-regions that bends the visible light contained in the transmitted light. The curvature indicates the degree to which the meta-regions bend the light transmitted through them. The smaller the curvature, the smaller the bending angle of the light transmitted through the meta-regions, and the more the light focusing is suppressed. Therefore, for example, even if sunlight enters the interior of a vehicle lamp from the outside, the bending angle of the infrared light contained in the sunlight is smaller than the bending angle of the visible light contained in the sunlight due to the aforementioned curvature. Therefore, according to this vehicle lamp, compared to a projection lens, the meta-regions can suppress the focusing of infrared light traveling from the meta-lens towards the light source. If the focusing of infrared light is suppressed, the degradation of the light source caused by the focusing of infrared light can be suppressed compared with the projection lens.

[0038] Furthermore, if the curvature of the element region that bends infrared light is smaller than that of the element region that bends visible light, the element region may also be configured such that, in the visible light and the infrared light with a wavelength ratio of 1:1.5, the phase modulation amount of the infrared light is smaller than 0.6 times the phase modulation amount of the visible light.

[0039] For example, in a refractive lens made of acrylic, if the curvature of the refractive lens that bends visible light is set to 1, the curvature of the refractive lens that bends infrared light is approximately 0.98. Similarly, in a refractive lens made of polycarbonate, if the curvature of the refractive lens that bends visible light is set to 1, the curvature of the refractive lens that bends infrared light is approximately 0.98. Therefore, whether it is acrylic or polycarbonate resin, the curvature of the refractive lens that bends infrared light is approximately 0.98 times that of the refractive lens that bends visible light. In this case, the refractive lens easily focuses infrared light. The curvature of the element region is approximately proportional to the product of the phase modulation of the light transmitted through the element region and the wavelength of that light. In this vehicle lamp, in visible light and infrared light with a wavelength ratio of 1:1.5, the phase modulation of infrared light is less than 0.6 times that of visible light, and thus the curvature of the element region that bends infrared light is less than 0.9 times that of the element region that bends visible light. If we compare the curvature of the element region that bends visible light with the curvature of the refractive lens that bends infrared light, using the curvature of each element that bends visible light as a reference, then the curvature of the element region that bends infrared light is smaller than the curvature of the refractive lens that bends infrared light. Therefore, in this vehicle lamp, the focusing of infrared light can be suppressed compared to the refractive lens.

[0040] Alternatively, if the curvature of the element region that bends infrared light is smaller than that of the element region that bends visible light, the longest wavelength of the visible light may be 660 nm and the shortest wavelength of the infrared light may be 1000 nm.

[0041] Furthermore, if the curvature of the element region that bends infrared light is smaller than that of the element region that bends visible light, the nanostructure can also be cylindrical. With such a structure, even if the visible light from the light source is randomly polarized, it can be effectively bent.

[0042] In addition, at least one resonant wavelength in the element lens can be above 800nm ​​and less than 2400nm.

[0043] In a primary lens, there is sometimes a phenomenon where the transmittance of light of a specific wavelength is extremely low compared to the transmittance of light of other wavelengths. It is known that there are generally multiple such specific wavelengths. These specific wavelengths are the wavelengths where the transmittance of light in the primary lens reaches its peak, and are called resonant wavelengths. These resonant wavelengths are determined by the size and shape of the nanostructures in each unit, the refractive index of the material constituting the nanostructures, etc. In this vehicle lamp, as described above, at least one resonant wavelength in the primary lens is 800 nm or more and less than 2400 nm. Typically, sunlight near the Earth's surface includes light in the wavelength range of 800 nm to 2400 nm. Therefore, according to this vehicle lamp, when sunlight shines through the primary lens onto the light source, compared to the case where the primary lens is a projection lens, the amount of sunlight with wavelengths from 800 nm to 2400 nm irradiating the light source can be reduced. Therefore, according to this vehicle lamp, compared to the case where the primary lens is a projection lens, the amount of heating of the light source caused by sunlight can be reduced, and the degradation of the light source caused by sunlight can be suppressed.

[0044] In addition, when at least one resonant wavelength in the element lens is above 800 nm and below 2400 nm, the at least one resonant wavelength may also be included in the range of above 800 nm and below 900 nm.

[0045] Typically, the intensity of sunlight near the Earth's surface tends to decrease with increasing wavelength in the wavelength range above 800 nm. It should be noted that the spectral distribution of sunlight exhibits several valleys where the intensity decreases sharply. The minimum intensity of such a valley is, for example, less than 50% of the intensity near that valley. These valleys tend to be located in the range between 800 nm and 900 nm. Therefore, by employing the structure described above, it is easy to reduce the amount of heat generated in the light source unit by sunlight when it passes through the element lens and illuminates the light source unit.

[0046] Alternatively, if at least one resonant wavelength in the element lens is greater than 800 nm and less than 2400 nm, the spectral distribution of the light emitted from the light source has multiple peaks, and the wavelengths of the multiple resonant wavelengths are different from the wavelengths of the multiple peaks.

[0047] The wavelength of light at the peak of the aforementioned spectral distribution tends to have a significant impact on the hue of the light emitted from the vehicle lamp. Therefore, according to this vehicle lamp, it is possible to suppress the decrease in transmittance of light of wavelengths that have a significant impact on the hue of the emitted light in the element lens, and to emit light of the desired hue.

[0048] In this case, none of the multiple resonant wavelengths are included in the wavelength region of the light emitted from the light source.

[0049] According to the vehicle lamp, compared to the case where at least one resonant wavelength is included in the wavelength range of light emitted from the light source, it is possible to emit light of a desired hue.

[0050] Furthermore, when at least one resonant wavelength in the element lens is greater than 800 nm and less than 2400 nm, the element lens can also reduce the divergence angle of the light from the light source transmitted through the element lens.

[0051] Alternatively, the light emitted from the light source may have a spectral distribution with multiple peaks, and the multiple resonant wavelengths in the element lens may be different from the wavelengths of the multiple peaks.

[0052] In this vehicle lamp, as described above, since the spectral distribution of the light emitted from the light source has multiple peaks, the hue of the emitted light can be made to the desired hue compared to the case where the spectral distribution has only one peak. Furthermore, in this vehicle lamp, as described above, the multiple resonant wavelengths in the element lens differ from the individual wavelengths of the multiple peaks. The wavelengths of light at each of the multiple peaks have a significant impact on the hue of the light emitted from the vehicle lamp. Therefore, according to this vehicle lamp, it is possible to suppress the decrease in transmittance of wavelengths that significantly affect the hue of the emitted light in the element lens, and to emit light with the desired hue.

[0053] Alternatively, when the spectral distribution of light emitted from the light source has multiple peaks, at least one of the multiple resonant wavelengths exceeds the shortest wavelength among the respective wavelengths of the multiple peaks and is less than the longest wavelength.

[0054] When the resonant wavelengths do not include those exceeding the shortest wavelength but less than the longest wavelength, the design of the size, shape, and arrangement of the nanostructures in each unit tends to become complex. Therefore, by adopting the structure described above, it is possible to suppress this complexity.

[0055] In this case, the wavelength of the light with the lowest intensity among the adjacent peaks can be the same as at least one of the plurality of resonant wavelengths.

[0056] With this structure, the reduction in the amount of emitted light can be suppressed compared to the case where the wavelength and resonant wavelength of light are the same except for the light with the lowest intensity between peaks.

[0057] Alternatively, when the spectral distribution of light emitted from the light source has multiple peaks, the multiple resonant wavelengths include specific resonant wavelengths contained in the wavelength region of the light from the light source, and the ratio of the intensity of the light at the specific resonant wavelength in the light to the maximum intensity in the overall spectral distribution of the light is 0.1 or less.

[0058] With this structure, compared to the case where the ratio exceeds 0.1, the reduction in the amount of emitted light can be suppressed.

[0059] Invention Effects

[0060] As described above, according to the present invention, it is possible to provide miniaturized vehicle lighting fixtures. Attached Figure Description

[0061] Figure 1 This is a schematic cross-sectional view showing a vehicle lamp according to a first embodiment of the present invention.

[0062] Figure 2 It is shown in general terms. Figure 1 The front view of the light source section is shown.

[0063] Figure 3 It is an enlarged representation Figure 1 A front view of a portion of one of the principal surfaces of the elemental lens shown.

[0064] Figure 4 This is a diagram that schematically illustrates a portion of the phase distribution specified in the first embodiment.

[0065] Figure 5 This is a diagram that schematically illustrates a portion of a specific phase distribution in the first embodiment.

[0066] Figure 6 This is a schematic cross-sectional view of the element lens in the second embodiment.

[0067] Figure 7 This is a schematic cross-sectional view of the element lens in the third embodiment.

[0068] Figure 8 Is with Figure 1 Similarly, a diagram of the vehicle lamp in the fourth embodiment is shown.

[0069] Figure 9 This is a schematic cross-sectional view showing the protective component and the element lens of the first modified example.

[0070] Figure 10 This is a diagram showing the low beam pattern formed on an imaginary vertical screen positioned 25m in front of the vehicle lamp according to the fifth embodiment.

[0071] Figure 11 This is a diagram showing an example of the light distribution pattern in the second variation.

[0072] Figure 12 This is a diagram showing another example of the light distribution pattern in the second variation.

[0073] Figure 13 This is a diagram showing an example of the light distribution pattern in the third variation.

[0074] Figure 14 This is a diagram showing an example of the light distribution pattern in the fourth variation.

[0075] Figure 15 This is a graph showing the relationship between the diameter of the nanostructure in the sixth embodiment and the respective phase modulation amounts of visible light with the longest wavelength of 660 nm and infrared light with the shortest wavelength of 1000 nm.

[0076] Figure 16 Is with Figure 1 Similarly, a diagram of the vehicle lamp in the seventh embodiment is shown.

[0077] Figure 17 This is a diagram that schematically shows the beam distribution of light emitted from the light source unit in the seventh embodiment and the transmittance distribution of light from the element lens.

[0078] Figure 18 It is a diagram that roughly shows the spectral distribution of sunlight near the Earth's surface and the transmittance distribution of light from the element lens in the seventh embodiment.

[0079] Figure 19 Is with Figure 17 Similarly, diagrams are shown of the beam distribution of light emitted from the light source section of the fifth modified example and the transmittance distribution of light from the element lens.

[0080] Figure 20 This is a diagram that schematically shows the beam distribution of light emitted from the light source unit in the eighth embodiment and the transmittance distribution of light from the element lens.

[0081] Figure 21 Is with Figure 20 Similarly, diagrams are shown of the beam distribution of light emitted from the light source section of the sixth modified example and the transmittance distribution of light from the element lens. Detailed Implementation

[0082] Hereinafter, preferred embodiments of the vehicle lamps of the present invention will be described in detail with reference to the accompanying drawings. The embodiments illustrated below are for ease of understanding of the present invention and are not intended to limit the scope of the invention. The present invention can be modified and improved without departing from its spirit. Furthermore, the constituent elements of the embodiments illustrated below can be appropriately combined. It should be noted that in the accompanying drawings, the dimensions of various components are sometimes changed for ease of understanding.

[0083] (First Implementation)

[0084] Figure 1This diagram illustrates a vehicle lamp according to the first embodiment of the present invention, and is a schematic cross-sectional view of the vehicle lamp in the vertical direction. The vehicle lamp 1 of this embodiment is a headlight for automobiles. Automobile headlights are generally located on the left and right sides of the front of a vehicle. In this specification, "right" refers to the right side in the direction of travel of the vehicle, and "left" refers to the left side in the direction of travel of the vehicle. The left and right headlights have the same structure except that their shapes are approximately symmetrical in the left-right direction. Therefore, in this embodiment, one headlight will be described. Figure 1 As shown, the vehicle lamp 1 of this embodiment is mainly composed of a frame 10, a light source 20, and an element lens 30.

[0085] In this embodiment, the frame 10, as the main structure, includes a lamp housing 11, a front cover 12, and a rear cover 13. The lamp housing 11 has an opening at the front, and the front cover 12 is fixed to the lamp housing 11 to block the opening. In addition, a smaller opening than the front opening is formed at the rear of the lamp housing 11, and the rear cover 13 is fixed to the lamp housing 11 to block the opening.

[0086] The space formed by the lamp housing 11, the front cover 12 blocking the opening at the front of the lamp housing 11, and the rear cover 13 blocking the opening at the rear of the lamp housing 11 is the lamp chamber R, which houses the light source unit 20 and the primary lens 30. The rear cover 13 is openable / closable or detachable relative to the lamp housing 11 so that the light source unit 20 and the primary lens 30 can be replaced through the opening at the rear of the lamp housing 11. The front cover 12 is made of a light-transmitting material, allowing light emitted from the light source unit 20 and passing through the primary lens 30 to pass through the front cover 12. The lamp housing 11 and the rear cover 13 are, for example, made of resin.

[0087] Figure 2 It is shown in general terms. Figure 1 The front view of the light source unit 20 is shown. In this embodiment, as... Figure 1 , Figure 2 As shown, the light source unit 20 has multiple light-emitting elements 21 that emit light and a circuit board 22 on which the multiple light-emitting elements 21 are mounted. It should be noted that... Figure 1 , Figure 2For ease of observation, only one light-emitting element 21 is labeled with a reference numeral, omitting the reference numerals for the other light-emitting elements 21. Multiple light-emitting elements 21 are arranged in a matrix, forming columns in the vertical and horizontal directions, emitting light forward. Each of the multiple light-emitting elements 21 can individually change the amount of light emitted by the power supplied to each of the multiple light-emitting elements 21. Furthermore, these light-emitting elements 21 are phosphor-type LEDs (Light Emitting Diodes) that emit white light, and the light source 20 is a so-called LED array, from which light emitted has a defined wavelength range. It should be noted that the number and structure of the light-emitting elements 21 are not particularly limited. For example, the light-emitting elements 21 can be a structure comprising multiple LEDs emitting light of different wavelengths, or a structure comprising multiple LDs (Laser Diodes) emitting light of different wavelengths.

[0088] This light source unit 20, by selecting the light-emitting elements 21 from which light is emitted, can emit light with a predetermined light distribution pattern. By changing this selection, the shape of the predetermined light distribution pattern can be changed. Furthermore, by adjusting the amount of light emitted from each light-emitting element 21, the light source unit 20 can adjust the intensity distribution of light within the predetermined light distribution pattern. In other words, the light source unit 20 can emit light with a predetermined light distribution pattern corresponding to the amount of light emitted from the multiple light-emitting elements 21, and can change the light distribution pattern of the emitted light. It should be noted that the light source unit 20 may also choose not to change the light distribution pattern of the emitted light.

[0089] The wavelength of the light L emitted from the light source unit 20 in this embodiment is within the wavelength region of visible light. The wavelength region of visible light is approximately 380 nm to 780 nm. The light L emitted from the light source unit 20 is light emitted from a plurality of light-emitting elements 21, therefore the wavelength of the light emitted from each light-emitting element 21 is approximately the same as the wavelength of the light L emitted from the light source unit 20. The wavelength of light L may not be included in the wavelength region of visible light.

[0090] The element lens 30 in this embodiment is a flat plate component configured to adjust the divergence angle of light transmitted in the thickness direction. The element lens 30 is positioned in front of the light source unit 20. Light L emitted from the light source unit 20 is incident on one planar principal surface 31s and exits from another planar principal surface 32s. Therefore, principal surface 31s is the incident surface for light L from the light source unit 20, and principal surface 32s is the exit surface for light L incident on principal surface 31s from the light source unit 20.

[0091] Figure 3 It is an enlarged representation Figure 1 A front view of a portion of a principal surface 31a of the element lens 30 shown. (See image) Figure 3As shown, the main surface 31s has multiple units 33 formed in two different directions, and each unit 33 contains a nanostructure 35. It should be noted that... Figure 3 In the diagram, the boundaries between adjacent units 33 are shown by dashed lines. Furthermore, for ease of observation, only one unit 33 and one nanostructure 35 are labeled with reference numerals, omitting the reference numerals for other units 33 and nanostructures 35. In this embodiment, multiple units 33 are arranged uniformly across the main surface 31s, and the entire main surface 31s can be understood as a meta-region containing multiple units 33 including nanostructures 35. The meta-lens 30 is circular in shape, and the multiple units 33 are arranged radially and circumferentially with respect to the centroid 31g of the main surface 31s. At this centroid 31g, a reference axis 36 orthogonal to the main surface 31s intersects the light source unit 20. The light-emitting element 21 of the light source unit 20 is arranged along a plane approximately perpendicular to the reference axis 36. The diameter of the meta-lens 30 is 10 mm or more, for example, 50 mm. Therefore, the minimum width of the meta-region is 10 mm or more. On the main surface 31s, the area except for the nanostructure 35 is planar, and the nanostructure 35 is a protrusion extending from the main surface 31s toward the light source section 20. Such a nanostructure 35 is formed into part of the primary lens 30 through ultra-fine processing of the main surface 31s, and becomes an integral part of the primary lens 30.

[0092] It should be noted that the arrangement of the multiple units 33, as well as the position and extent of the element region, are not particularly limited. For example, the element region can be a part of the main surface 31s, or at least a part of the main surface 32s on the side opposite to the light source section 20. Alternatively, the element region can be at least a part of both the main surface 31s and the main surface 32s. Figure 3 The shape of the unit 33 shown is approximately quadrilateral, but there are no particular restrictions. Furthermore, the size and shape of multiple units 33 can also differ from each other. Additionally, there are no particular restrictions on the size of the element lens 30 and the element region; for example, the diameter of the element lens 30 can be less than 10 mm. Furthermore, there are no particular restrictions on the shape of the element lens 30; for example, it can also be quadrilateral.

[0093] In this embodiment, the nanostructure 35 is cylindrical in shape, and its diameter is smaller than the longest wavelength of the light emitted from the light source 20. It should be noted that the shape of the nanostructure 35 is not particularly limited, as long as the width of the nanostructure 35 is smaller than the longest wavelength of the light emitted from the light source 20. For example, the shape of the nanostructure 35 can be a quadrangular prism or a C-shape. Furthermore, the nanostructure 35 can be composed of a pair of quadrangular prisms arranged at a predetermined interval. Additionally, the shapes of the nanostructures 35 in each unit 33 can be different. Furthermore, multiple nanostructures 35 can be provided in each unit 33, and the number of nanostructures 35 in each unit 33 can be different. Additionally, materials constituting the element lens 30 can include, for example, glass and resin. It should be noted that the materials constituting the nanostructure 35 and the parts other than the nanostructure 35 can be the same or different.

[0094] The unit 33 containing such nanostructures 35 can modulate the phase of the light L transmitted through the unit 33. Furthermore, by adjusting the arrangement of the multiple units 33 and the size and shape of the nanostructures 35 in each unit 33, the phase distribution of the light L transmitted through the element region can be changed, thereby altering the divergence angle of the white light L transmitted through the element lens 30. In this embodiment, the arrangement of the multiple units 33 and the size and shape of the nanostructures 35 in each unit 33 are adjusted to reduce the divergence angle of the light L to a predetermined divergence angle. Therefore, it can be understood that the element region is configured to modulate the phase of the light L, thereby making the divergence angle of the light L a predetermined divergence angle.

[0095] Specifically, in this embodiment, the element region is configured such that, when a reference light parallel to the aforementioned reference axis 36 is incident on this element region, the phase distribution of the reference light emitted from the element lens 30 becomes... Figure 4 The phase distribution shown is a specific phase distribution formed by the remainder after dividing the specified phase distribution by 50 and then dividing by 2π. It should be noted that... Figure 4 This diagram schematically illustrates a portion of the defined phase distribution 50 in this embodiment, showing the defined phase distribution 50 on a vertical plane including the aforementioned reference axis 36. Furthermore, the phase distribution of the reference light emitted from the element lens 30 refers to the phase distribution on an imaginary plane perpendicular to the reference axis 36; in this embodiment, this imaginary plane is the phase distribution along the plane that serves as the exit surface 32s of the element lens 30. Figure 4 In this diagram, the x-axis represents the phase retardation (rad), the y-axis is the distance from the intersection point 32p of the reference axis 36 and the principal plane 32s to the direction perpendicular to the reference axis 36, and r is the radius of the elementary lens 30. For example... Figure 4As shown, the defined phase distribution 50 on the vertical plane including the reference axis 36 is a curve in which the amount of phase retardation decreases as the distance from the reference axis 36 moves away in a direction perpendicular to the reference axis 36, and the rate of decrease of the amount of phase retardation increases. Furthermore, although the explanation based on the illustration is omitted, the defined phase distribution 50 on any plane including the reference axis 36 is... Figure 4 The curves shown are identical to the prescribed phase distribution 50. Therefore, the prescribed phase distribution 50 can be understood as a phase distribution in which the amount of phase retardation decreases as it moves away from the reference axis 36, and the rate of decrease of the amount of phase retardation increases. Here, by constructing the element region in such a way that the phase distribution of the reference light is such a prescribed phase distribution 50, the divergence angle of the light emitted from the element lens 30 through the element region can be reduced. In addition, when the phase retardation of the light is an integer multiple of 2π, it can be considered that the wavefront of the light is the same as the wavefront of the light without phase retardation. Therefore, even if the element lens 30 of this embodiment is constructed in such a way that the phase distribution of the reference light is a specific phase distribution obtained by dividing the prescribed phase distribution 50 by 2π, the divergence angle of the light L can be reduced. It should be noted that the prescribed phase distribution 50 is only required to be a phase distribution in which the amount of phase retardation decreases as it moves away from the reference axis 36, and the rate of decrease of the amount of phase retardation increases. These phase retardation amounts and the rate of decrease of the phase retardation amounts can be adjusted according to the degree of adjustment of the divergence angle, etc. In addition, the reference axis 36 is not limited to an axis passing through the center of gravity 31g, but can be any axis that is orthogonal to the meta-region at a specific position in the meta-region.

[0096] In addition, in this embodiment, such as Figure 5 As shown, the specific phase distribution 60, formed by dividing the prescribed phase distribution 50 by 2π, has multiple peaks 61. It should be noted that... Figure 5 This is a diagram that schematically illustrates a portion of a specific phase distribution 60 in this embodiment, and a diagram that illustrates a portion of a specific phase distribution 60 on a vertical plane including the aforementioned reference axis 36. Figure 5 In this diagram, the x-axis represents the phase retardation (rad), the y-axis is the distance from the intersection point 32p of the reference axis 36 and the principal plane 32s to the direction perpendicular to the reference axis 36, and r is the radius of the elementary lens 30. Additionally, in... Figure 5 The diagram shows dashed lines representing y = r and x = 2π. Additionally, in... Figure 5 In this diagram, for ease of observation, only the four peak values ​​61 are labeled with the attached figures, while the labels for the other peak values ​​61 are omitted. For example... Figure 5As shown, as the phase retardation in a specific phase distribution 60 on a plane containing the reference axis 36 moves away from the reference axis 36 in a direction perpendicular to the reference axis 36, the phase retardation periodically repeats a change from a value infinitely close to 2π to zero. The width of this period narrows with distance from the reference axis 36, with a maximum width of approximately 400 μm and a width of approximately 100 μm for the period adjacent to this maximum. The minimum width is approximately 1 μm. It should be noted that, as described above, the defined phase distribution 50 on any plane containing the reference axis 36 is... Figure 4 The curve is the same as the specified phase distribution 50 shown. Therefore, the amount of phase delay in a specific phase distribution 60 on any plane containing the reference axis 36 changes from a value infinitely close to 2π to zero as it periodically repeats away from the reference axis 36. Therefore, the amount of phase delay in a specific phase distribution 60 can be understood as the above-mentioned change repeating periodically as it moves away from the reference axis 36. Here, the fewer the number of units arranged relative to one cycle of the above-mentioned change, the greater the deviation between the phase distribution varying according to the meta-region and the specific phase distribution 60, and the proportion of the energy of the light emitted from the meta-region at the divergence angle corresponding to the specific phase distribution 60 tends to decrease relative to the energy of the light incident on the meta-region. In this embodiment, when viewed along the reference axis 36, multiple units 33 are arranged such that there are two or more units 33 between adjacent peaks 61 in the direction away from the center of gravity 31g. That is, two or more units 33 are arranged for one cycle of the above-mentioned change. By arranging the units 33 in this way, the energy loss of light caused by the meta-lens 30 can be easily reduced to a level suitable for use in lenses for vehicle lamps. Furthermore, in this embodiment, the nanostructure 35 is cylindrical. Moreover, the inventors discovered that by arranging three or more units 33 within one cycle of the aforementioned variation and making the nanostructure 35 cylindrical, the energy of light emitted from the elementary region at a divergence angle corresponding to the specific phase distribution 60 can be set to a ratio of 60% or more to the energy of light incident on the elementary region. Therefore, from the viewpoint of reducing light energy loss in the elementary lens 30, such a structure is preferred. Additionally, in this embodiment, the specific phase distribution 60 has three or more peaks 61. Furthermore, when viewed along the reference axis 36, the number of units 33 located between adjacent peaks 61 in the direction away from the center of gravity 31g decreases as the distance from the center of gravity 31g increases.

[0097] In the vehicle lamp 1 of this embodiment, light L, whose divergence angle is reduced by such a lens 30, is emitted towards the front of the vehicle via the front cover 12. Therefore, the vehicle lamp 1 of this embodiment can easily make the size of the emitted light's light distribution pattern as desired. In addition, as described above, the light source unit 20 can change the light distribution pattern of the emitted light. Therefore, according to the vehicle lamp 1, for example, it is possible to switch between high beam and low beam, or to emit ADB (Adaptive Driving Beam).

[0098] As described above, the vehicle lamp 1 of this embodiment includes a light source 20 and a primary lens 30. The primary lens 30 has a main surface 31s serving as a primary region. Multiple units 33, each including a nanostructure 35 smaller than the longest wavelength of the light L emitted from the light source 20, are arranged on this main surface 31s, through which the light L emitted from the light source 20 passes. The main surface 31s, serving as a primary region, causes a change in the phase distribution of the light L transmitted through it. In the projection lens of a vehicle lamp, at least one of the incident surface and the emission surface is typically curved, and the divergence angle of the light emitted from the light source is adjusted by changing the shape of this curved surface. Therefore, in such a projection lens, a certain thickness is required to form this curved surface. On the other hand, the primary lens 30 of the vehicle lamp 1 of this embodiment, by adjusting the arrangement of the multiple units 33 or the size of the nanostructures 35 in each unit 33, changes the phase distribution of the light L from the light source, thereby adjusting the divergence angle of the light L. Therefore, even if the curvature of the principal surface 31s, which is the principal region, of the element lens 30 in this embodiment is smaller than the curvature of the surface of the projection lens described above, for example, if the principal surface 31s is formed into a planar shape, the divergence angle of the light from the light source 20 can be adjusted, and it can be thinner than the projection lens described above. Therefore, the vehicle lamp 1 according to this embodiment can achieve miniaturization compared to the case where the divergence angle of the light L from the light source 20 is adjusted using the projection lens described above.

[0099] Generally, increasing the size of the lens can easily increase the amount of light emitted from it. In this embodiment, the minimum width of the main surface 31s, which is the element region, is 10 mm or more. Therefore, in this embodiment, it is easy to make the light distribution pattern of the light emitted from the element lens 30 the brightness required for the light distribution pattern of the light emitted from a vehicle headlight. It should be noted that the light distribution pattern of the light emitted from the vehicle headlight can be, for example, a low beam or high beam light distribution pattern.

[0100] (Second Implementation)

[0101] Next, the second embodiment of the present invention will be described in detail. It should be noted that structural elements that are the same as or equivalent to those in the first embodiment are labeled with the same reference numerals in the accompanying drawings, and repeated descriptions are omitted unless specifically stated otherwise. In this embodiment, the structure of the element lens 30 differs from that in the first embodiment.

[0102] Figure 6 This is a schematic cross-sectional view of the element lens in this embodiment, a schematic cross-sectional view showing the thickness direction of the element lens. (Example) Figure 6 As shown, in the elemental lens 30 of this embodiment, the principal surface 31s, which serves as the incident surface for light L from the light source 20, is a curved surface that is convex outward. On this curved principal surface 31s, the light L is refracted in such a way that the divergence angle of the light L from the light source 20 decreases. Furthermore, the principal surface 32s, which serves as the exit surface for light L from the light source 20, is a unit region containing a plurality of units 33, including nanostructures 35, through which the light L from the light source 20 incident on the principal surface 31s passes. Additionally, the reference axis 36 is orthogonal to the principal surface 32s at its centroid 32g, a specific position on the principal surface 32s, and intersects with the light source 20. Moreover, similar to the first embodiment, the unit region is configured such that, when a reference light parallel to the reference axis 36 is incident on this unit region, the phase distribution of the reference light emitted from the elemental lens 30 becomes a specific phase distribution 60, which is the remainder after dividing a predetermined phase distribution 50 by 2π. It should be noted that the main surface 31s, which is the incident surface, can refract the light L in a way that it is convexly curved outward and the divergence angle of the light L from the light source section 20 is reduced, or it can be a structure in which part of it is convexly curved outward.

[0103] Generally, if the divergence angle of light incident on the element region increases, the design of the element region tends to become more complex. In the element lens 30 of this embodiment, the light L from the light source 20, after passing through the curved incident surface, i.e., the principal surface 31s, reduces the divergence angle, and then enters the principal surface 32s, which serves as the element region. Therefore, in this embodiment, compared to the case where the principal surface 31s is flat, the divergence angle of light L from the light source 20 incident on the element region can be reduced. Therefore, the vehicle lamp 1 according to this embodiment can suppress the complexity of the element region design, and is particularly useful in reducing the divergence angle of light L from the light source 20 as in this embodiment.

[0104] It should be noted that at least a portion of the principal surface 31s is a meta-region, and the principal surface 32s is convexly curved outwards, allowing light L, which passes through the meta-region, to also exit from the principal surface 32s. Generally, if the angle of light divergence is increased by adjusting the meta-region, the design of the meta-region tends to become more complex. Based on this structure, compared to the case where the principal surface 32s is planar, the angle of light divergence L can be reduced by decreasing the meta-region, thus suppressing the complexity of the meta-region design.

[0105] (Third Implementation)

[0106] Next, the third embodiment of the present invention will be described in detail. It should be noted that structural elements that are the same as or equivalent to those in the first embodiment are labeled with the same reference numerals in the accompanying drawings, and repeated descriptions are omitted unless specifically stated otherwise. In this embodiment, the structure of the element lens 30 differs from that in the first embodiment.

[0107] Figure 7 This is a schematic cross-sectional view of the element lens 30 in this embodiment, a schematic cross-sectional view of the element lens 30 in the thickness direction. Figure 7 As shown, in the element lens 30 of this embodiment, a plurality of slots 37 are provided on the planar main surface 31s, which serves as the incident surface for light L from the light source unit 20. It should be noted that... Figure 7 In this description, the groove 37 is exaggerated, with only one groove 37 marked with a reference numeral, omitting reference numerals for the other grooves 37. Each groove 37 extends along a circle centered on the centroid 31g, which is the center of the principal surface 31s. On the principal surface 31s with multiple grooves 37, the light L diffracts in such a manner that the divergence angle of the light L from the light source 20 decreases. That is, the shape, depth, width, and position of the grooves 37 are adjusted to diffract the light L in this way, which can be understood as the principal surface 31s diffracting the light L. Furthermore, the principal surface 32s from which the light L from the light source 20 is emitted is an entire meta-region containing multiple units 33, including nanostructures 35, through which the light L from the light source 20 passes. In addition, the reference axis 36 is orthogonal to the principal surface 32s at the centroid 32g, which is a specific position on the principal surface 32s, and intersects with the light source 20. Furthermore, similar to the first embodiment, the element region is configured such that, when reference light parallel to the aforementioned reference axis 36 is incident on this element region, the phase distribution of the reference light emitted from the element lens becomes a specific phase distribution 60 formed by the remainder after dividing a predetermined phase distribution 50 by 2π. It should be noted that the principal surface 31s, as the incident surface, only needs to diffract the light L from the light source section 20 provided with multiple slots 37 in a manner that reduces the divergence angle of the light L; there are no restrictions on the shape, number, or position of the slots 37. Alternatively, slots 37 may be provided on a curved principal surface 31s.

[0108] Furthermore, in the element lens 30 of this embodiment, the light L from the light source 20 enters the element region after its divergence angle is reduced by passing through the incident surface, i.e., the principal surface 31s. Therefore, compared to the case where the principal surface 31s into which the light L from the light source 20 enters is planar, the divergence angle of the light L entering the principal surface 31s can be reduced by passing through the element region. Therefore, the vehicle lamp 1 according to this embodiment can suppress the complexity of the element region design, and is particularly useful in reducing the divergence angle of the light L from the light source 20 as in this embodiment.

[0109] It should be noted that, from the viewpoint of suppressing the complexity of the design of the meta-region, multiple slots 37 can be provided on the main surface 31s, which is convexly curved outwards. This main surface 31s causes the light L from the light source section 20 to diffract. Furthermore, since at least a portion of the main surface 31s is a meta-region, the main surface 32s can also cause the light L transmitted through the meta-region to diffract in a manner that reduces the divergence angle. With this structure, compared to the case where the main surface 32s is planar, the divergence angle of the light L can be reduced by using the meta-region, thus suppressing the complexity of the meta-region design.

[0110] (Fourth Implementation)

[0111] Next, the fourth embodiment of the present invention will be described in detail. It should be noted that structural elements that are the same as or equivalent to those in the first embodiment are marked with the same reference numerals in the accompanying drawings, and repeated descriptions are omitted unless specifically stated otherwise.

[0112] Figure 8 Is with Figure 1 Similarly, a diagram of the vehicle lamp 1 in this embodiment is shown. It should be noted that, in Figure 8 The description of the frame 10 and the light source unit 20 is omitted. For example... Figure 8 As shown, the vehicle lamp 1 of this embodiment differs from the vehicle lamp 1 of the first embodiment in that it also has a light-transmitting protective component 40.

[0113] The protective member 40 of this embodiment is composed of a main body 41 and a rib 42. The main body 41 is a circular plate-shaped component, arranged such that a main surface 43s is positioned opposite the main surface 31s of the element lens 30 at a predetermined interval. In a direction parallel to the reference axis 36, the main surface 31s, which serves as the element region, overlaps the main body 41 entirely. The rib 42 is provided on the main surface 43s of the main body 41 and protrudes toward the element lens 30. The rib 42 extends circumferentially along the outer edge of the main body 41. The inner circumferential surface of the rib 42 is bonded circumferentially to the outer circumferential surface of the element lens 30, and the protective member 40 is fixed to the element lens 30. The protective member 40 covers the main surface 31s, which serves as the element region, in a non-contact manner, with the main surface 31s exposed in the enclosed space 45 formed by the protective member 40 and the element lens 30. The main body 41 and the rib 42 are integrally formed, and the materials constituting the protective member 40 include, for example, glass and resin.

[0114] In this embodiment, light L emitted from the light source 20 passes through the main body 41 of the protective member 40 and enters the element lens 30. The element lens 30 adjusts the divergence angle of the light L, and the light L with the adjusted divergence angle is emitted forward of the vehicle via the front cover 12. In this embodiment, as described above, the protective member 40 covers the main surface 31s, which is the element region. Therefore, it is possible to suppress the entry of dust or the like between the individual nanostructures 35, or the adhesion of dust or the like to the nanostructures 35, or the damage to the nanostructures 35, and the divergence angle of the light L from the light source 20 can be appropriately adjusted.

[0115] It should be noted that the ribs 42 of the protective component 40 may also be provided with a connecting part such as a hole to connect the enclosed space 45 to the outside. However, from the viewpoint of preventing dust and the like from entering between the individual nanostructures 35 or from dust and the like adhering to the nanostructures 35, it is preferable not to provide such a hole in the protective component 40.

[0116] Additionally, the protective component 40 can also come into contact with the nanostructure 35, for example, such as... Figure 9 As shown, the main body 41 of the protective component 40 can be filled between the various nanostructures 35. It should be noted that... Figure 9 This is a schematic cross-sectional view showing the protective member 40 and the element lens 30 of the first modified example, and a view showing a portion of a cross-section in the thickness direction of the protective member 40 and the element lens 30. Additionally, in Figure 9 For ease of observation, only one nanostructure 35 is labeled in the attached figure, while the labels for the other nanostructures 35 are omitted. In this case, the refractive index of the protective component 40 is lower than that of the element lens 30. Even with this structure, the divergence angle of light L can be adjusted via the element lens 30.

[0117] (Fifth implementation method)

[0118] Next, the fifth embodiment of the present invention will be described. It should be noted that, unless otherwise specified, structural elements that are the same as or equivalent to those in the first embodiment will be labeled with the same reference numerals in the accompanying drawings, and repeated descriptions will be omitted. In this embodiment, the structure of the element lens 30 differs from that in the first embodiment.

[0119] In this embodiment, the phase distribution of light L transmitted through the elemental region is changed by adjusting the arrangement of multiple units 33 and the size and shape of the nanostructures 35 in each unit 33 in a coma-like manner within the elemental lens 30. Coma refers to an aberration in which a point image on the image plane does not form a single point but rather extends like a comet's tail. On the image plane, light does not radiate outwards from the point image due to coma, but rather extends in a certain direction. Thus, it can be understood that the divergence angle of light is expanded due to coma.

[0120] In this embodiment, the divergence angle of the light L transmitted through the element region is expanded by coma, compared to the case where no coma is generated. Due to the expansion of the divergence angle of the light L, the light distribution pattern formed by the light L transmitted through the element region is projected onto the exterior of the vehicle lamp 1 in an expanded state compared to the case where no coma is generated.

[0121] Figure 10 This diagram shows the low beam pattern formed on an imaginary vertical screen positioned 25m in front of the vehicle lamp 1 according to this embodiment. Figure 10 In the image, the light distribution pattern 70 projected from the elementary lens 30, which produces coma, is represented by a solid line. Additionally, in... Figure 10 In the image, dashed lines represent the light distribution pattern 80 projected from a primary lens without coma aberration.

[0122] exist Figure 10 In order to make the light distribution patterns 70 and 80 clear, the upper and lower ends of the light distribution pattern 80 are shown in a position further inward than the upper and lower ends of the light distribution pattern 70, but the upper and lower ends of the light distribution pattern 80 are located in the same position as the upper and lower ends of the light distribution pattern 70. The centers of the light distribution patterns 70 and 80 are set to be in the same position.

[0123] exist Figure 10In the diagram, S represents a horizontal line, C represents a reference axis that passes through the center of the left-right light distribution pattern 70, is orthogonal to the light distribution pattern 70, and extends forward and backward along the vehicle, and V represents a vertical line orthogonal to the reference axis C. The light distribution pattern 70 has cut-off lines CL1, CL2, and CL3 at its upper end. Cut-off line CL1 is positioned on the opposite side of cut-off line CL3, with cut-off line CL2 as a reference. The intersection of cut-off lines CL1 and CL2 is called the inflection point EP. Inflection point EP is located below the horizontal line S and on the vertical line V. Inflection point EP may also be located below the horizontal line S and near the vertical line V. Cut-off line CL1 extends horizontally from inflection point EP to the right side, which is the left-right direction of the vehicle. Cut-off line CL2 extends diagonally upward and to the left from inflection point EP in the up-down-left-right direction of the vehicle. The end of cut-off line CL2 on the opposite side of inflection point EP is located above the horizontal line S. The cutoff line CL3 extends horizontally from the aforementioned end of the cutoff line CL2 towards the left side of the vehicle in the left-right direction. As a light distribution pattern 70, the light intensity is highest in the hot zone HZL near the inflection point EP and gradually decreases with distance from the hot zone HZL.

[0124] In this embodiment, the meta-region generates a coma aberration that causes the point image in the light distribution pattern 70 to extend from the inside to the outside of the light distribution pattern 70 in the left-right direction, thus changing the phase distribution of the light L transmitted through the meta-region. Therefore, compared to the case where no coma aberration is generated, the meta-region of this embodiment expands the divergence angle of the light L in the left-right direction of the light distribution pattern 70 formed by the light L through coma aberration, making the light distribution pattern 70 more extended than the light distribution pattern 80 in the left-right direction. A portion of the light distribution pattern 70 between the V-line and the left end of the light distribution pattern 70 is designated as region 70a, and the remaining portion of the light distribution pattern 70 between the V-line and the right end of the light distribution pattern 70 is designated as region 70b. When the meta-lens 30 is viewed from the vertical direction, the meta-region expands the divergence angle of the light L forming region 70a to the left from the reference axis C of the light distribution pattern 70 through coma aberration. Furthermore, when the elementary lens 30 is viewed from the vertical direction, the elementary region extends the divergence angle of the light L forming region 70b to the right from the reference axis C of the light distribution pattern 70 through coma aberration. Thus, the light distribution pattern 70 becomes a pattern in which the left end of the light distribution pattern 80 in region 70a extends to the left as the outer side, and in region 70b, the right end of the light distribution pattern 80 extends to the right as the outer side. The elementary region makes the divergence angle of the light L forming region 70a and extending to the left the same as the divergence angle of the light L forming region 70b and extending to the right. Therefore, the extension amounts at the right and left ends of the light distribution pattern 70 can be the same, making the design of the elementary lens 30 easier compared to cases where the extension amounts are different.

[0125] As described above, in this embodiment, the phase distribution of light L transmitted through the element region is changed in a way that produces coma aberration, and compared with the case where no coma aberration is produced, the divergence angle of light L transmitted through the element region is extended in the left and right directions of the light distribution pattern 70.

[0126] In the element lens 30, even without coma aberration, the divergence angle of light L can be extended by adjusting the arrangement of the multiple units 33, the size and shape of the nanostructures 35 in each unit 33, etc. However, in the element region of this embodiment, even with the same divergence angle as that extended without coma aberration, the divergence angle can be further extended in the left-right direction due to the extension of light L caused by coma aberration. Therefore, according to the vehicle lamp 1 of this embodiment, the light distribution pattern 70 can be further extended in the left-right direction compared to the light distribution pattern projected from the element lens 30 that extends the divergence angle of light L without coma aberration.

[0127] Furthermore, projection lenses with curved surfaces, as described above, are typically designed to suppress coma. Therefore, when using a projection lens, the expansion of the divergence angle of light from the light source is suppressed, thus suppressing the expansion of the light distribution pattern projected onto the exterior of the vehicle lamp. In contrast, in the elemental region of the elemental lens 30, which is configured as the projection lens of this embodiment, the divergence angle of light L from the light source 20 expands as described above due to coma, therefore the light distribution pattern 70 can be expanded compared to the light distribution pattern projected from the projection lens.

[0128] Furthermore, in the vehicle lamp of Patent Document 2, both a projection lens and an auxiliary lens are used to expand the light distribution pattern. However, in the element lens 30 of this embodiment, compared to the case where the light distribution pattern is expanded using a projection lens and a lens different from the projection lens, it is not necessary to adjust the relative positions of the projection lens and the auxiliary lens, thus reducing the number of components and the weight of the vehicle lamp 1. In addition, compared to the case where the divergence angle of light is expanded using the aforementioned projection lens and other lenses, the vehicle lamp 1 of this embodiment can expand the divergence angle of light L using a single element lens 30, achieving miniaturization.

[0129] Furthermore, the expansion of the light distribution pattern 70 is adjusted by the expansion of the divergence angle of the light L. The expansion of the divergence angle is adjusted by the aforementioned extension of the light L, which represents the degree of coma aberration. The extension of the light L is adjusted by the arrangement of the multiple units 33 and the size and shape of the nanostructures 35 in each unit 33. In this way, since the design freedom of the element lens 30 is increased, the expansion of the light distribution pattern 70 can be easily controlled in the vehicle lamp 1 of this embodiment, compared with a projection lens that unintentionally produces coma aberration due to manufacturing precision.

[0130] It should be noted that even if one intends to intentionally produce coma in the projection lens, the degree of freedom in the expansion of the light distribution pattern is limited by factors such as the shape of the projection lens and the light distribution pattern projected by the projection lens. However, in the vehicle lamp 1 of this embodiment, by adjusting the degree of coma, the degree of freedom in the expansion of the light distribution pattern 70 can be increased compared to a projection lens that intentionally produces coma.

[0131] Furthermore, even if the projection lens produces coma, the divergence angle of light L may not necessarily extend in the left-right direction away from the reference axis C of the light distribution pattern 70, nor may the light distribution pattern be easily extended in the left-right direction. However, in the vehicle lamp 1 of this embodiment, by arranging the multiple units 33 and adjusting the size and shape of the nanostructures 35 in each unit 33, the light distribution pattern 70 can be easily extended in the left-right direction. In addition, in the vehicle lamp 1 of this embodiment, compared with the fabrication of a projection lens that intentionally produces coma in order to extend the light distribution pattern 70 in the left-right direction, the element lens 30 can be easily fabricated.

[0132] Other light-diverging aberrations besides coma used in the element lens 30 of this embodiment include spherical aberration, astigmatism, and image plane aberration. In these three aberrations, light on the image plane sometimes diffuses radially from a reference point image to the surrounding area. Therefore, in these three aberrations, like coma, blurring extends not only to the outer edge of the light distribution pattern but also to the inner edge. Thus, a light distribution pattern expanded by one of these three aberrations is less effective than one expanded by coma. In contrast, in the element lens 30 of this embodiment, coma causes the divergence angle of light L to expand only in the left-right direction away from the reference axis C of the light distribution pattern 70. Therefore, compared to the other three aberrations, it is easier to effectively expand the light distribution pattern 70 in the left-right direction, and the direction of expansion can be defined as one direction. Furthermore, in these three aberrations, due to the aforementioned diffusion, brightness blurring sometimes occurs at the left and right ends of the light distribution pattern. In contrast, in the element lens 30 of this embodiment, the direction of light distribution pattern expansion is controlled to be the outer side of the light distribution pattern in the left-right direction by coma aberration. Therefore, in the element lens 30 of this embodiment, the amount of light can gradually decrease from the inside to the outside around the left and right ends of the light distribution pattern, and compared with the other three aberrations, the blurring of the brightness at the left and right ends of the light distribution pattern can be suppressed.

[0133] As described above, in the image plane, light extends from a point image in a certain direction due to coma aberration. The amount of light extension corresponds to the extension angle from the point image in the image plane to the outermost angle of the comet-shaped diverging light extending from that point image. The amount of light extending due to coma aberration is the most abundant in the point image and gradually decreases further away from the point image. In the element lens 30 of this embodiment, the amount of light at the left and right ends of the extended light distribution pattern 70 gradually decreases from the center side of the light distribution pattern 70 outwards, which can suppress the generation of uneven light distribution at the left and right ends of the light distribution pattern 70. Furthermore, from the viewpoint of suppressing uneven light distribution in the light distribution pattern 70, the amount of light extension only needs to be about 15% of the extension angle of the light forming the point image on the image plane, and it is very effective if it is 50% of that extension angle.

[0134] The beam pattern 70 is described as a beam pattern for low beam, but it can also be a beam pattern for high beam.

[0135] The meta-region can also suppress coma at the center of the light distribution pattern 70, and expand the divergence angle towards the ends of the light distribution pattern 70. This maintains the light intensity at the center while ensuring an expanded field of view for the driver. Furthermore, the meta-region can expand either the divergence angle of light L extending to the left from region 70a or the divergence angle of light L extending to the right from region 70b. This allows expansion of only one end of the light distribution pattern 70, either the right or left. Alternatively, the meta-region can form region 70a, expanding the divergence angle of at least a portion of the light L extending to the left. This expands at least a portion of the left end of the light distribution pattern 70. Similarly, the meta-region can form region 70b, expanding the divergence angle of at least a portion of the light L extending to the right. This expands at least a portion of the right end of the light distribution pattern 70.

[0136] Taking the fifth embodiment as an example, a vehicle lamp 1 equipped with a primary lens 30 is described. This primary lens 30 has a primary region that changes the phase distribution of light L in a manner that produces coma aberration. However, such a vehicle lamp 1 is not limited to this. The following describes a second, third, and fourth modification example of such a vehicle lamp 1.

[0137] First, use Figure 11 as well as Figure 12 The second variation will be explained. Figure 11 This is a diagram illustrating an example of the light distribution pattern in the second variation. Figure 12This is a diagram illustrating another example of the light distribution pattern in the second variation. In this variation, the meta-region may also cause one of the divergence angles of the light L diffused from region 70a and to the left of the reference axis C of the light distribution pattern 70, and the light L diffused from region 70b and to the left of the reference axis C of the light distribution pattern 70, to be larger than the other. Consequently, one of the expansion amounts at the right end and the expansion amounts at the left end of the light distribution pattern 70 is greater than the other. For example, if the meta-region causes the divergence angle of the light L diffused from region 70a and to the left of the reference axis C of the light distribution pattern 70 to be larger than the divergence angle of the light L diffused from region 70b and to the right of the reference axis C of the light distribution pattern 70, then... Figure 11 As shown, the left end of the light distribution pattern 70 is wider than the right end. In this case, the illumination range of light L on pedestrians, road signs, and other objects on the sidewalk located on the side of the driving lane can be extended. Furthermore, for example, if the meta-region causes the divergence angle of light L forming region 70b and diffusing to the right from the reference axis C of the light distribution pattern 70 to be larger than the divergence angle of light L forming region 70a and diffusing to the left from the reference axis C of the light distribution pattern 70, then as... Figure 12 As shown, the right end of the light distribution pattern 70 is wider than the left end. In this case, the illumination range of light L on objects such as pedestrians on the sidewalk located on the opposite lane can be extended. Therefore, drivers of vehicles can more easily visually identify objects located on the side where the light distribution pattern widens.

[0138] Next, use Figure 13 The third embodiment will be described. Figure 13 This diagram illustrates an example of the light distribution pattern in the third variation. The light distribution pattern 70 in this variation is formed by the overlap of a light distribution pattern 71 projected from the left side of the vehicle lamp 1 and a light distribution pattern 73 projected from the right side of the vehicle lamp 1. To facilitate observation of the light distribution patterns 71 and 73, a shadow extending diagonally upwards to the left is marked on the light distribution pattern 71, and a shadow extending diagonally upwards to the right is marked on the light distribution pattern 73. The left end of the light distribution pattern 71 is located further outwards than the left end of the light distribution pattern 73. Furthermore, the right end of the light distribution pattern 73 is located further outwards than the right end of the light distribution pattern 71.

[0139] Like light distribution pattern 70, light distribution pattern 80 is formed by overlapping the light distribution patterns projected from the left and right vehicle lamps 1. To easily distinguish it from light distribution patterns 71 and 73, no shading is marked on light distribution pattern 80.

[0140] The elemental region of the vehicle lamp 1 on the left extends the divergence angle of light L away from the reference axis C of the light distribution pattern 70, i.e., to the left, from that light axis, through coma aberration. Therefore, the left end of the light distribution pattern 71 extends further to the left than the left end of the light distribution pattern 80. Similarly, the elemental region of the vehicle lamp 1 on the right extends the divergence angle of light L away from the reference axis C of the light distribution pattern 70, i.e., to the right, from that light axis, through coma aberration. Therefore, the left end of the light distribution pattern 73 extends further to the right than the right end of the light distribution pattern 80.

[0141] Thus, even when a light distribution pattern 70 is formed by overlapping the light distribution patterns 71 and 73 projected from the left and right vehicle lamps 1, the light distribution pattern 70 can be expanded to the left and right. Furthermore, in this modified example, for example, by replacing the left-side element lens 30 with another left-side element lens 30 that has a different degree of coma aberration than the original left-side element lens 30, the expansion of the light distribution pattern in the left direction can be adjusted.

[0142] Next, use Figure 14 The fourth embodiment will be described. Figure 14 This is a diagram illustrating an example of the light distribution pattern in the fourth variation. Figure 14In this diagram, S1 is a line parallel to the horizontal line S, passing through the center of the light distribution pattern 70. A portion of the light distribution pattern 70 between line S1 and the upper end of the light distribution pattern 70 is designated as region 70c, and the remaining portion between line S1 and the lower end of the light distribution pattern 70 is designated as region 70d. The light distribution pattern 70 is used for near beams, and the position of the cut-off line needs to be fixed. Therefore, when the elementary lens 30 is viewed from a horizontal direction, the divergence angle of the light L forming region 70c extends upwards from the reference axis C of the light distribution pattern 70 via coma aberration, and the divergence angle of the light L forming region 70d extends downwards from the reference axis C of the light distribution pattern 70 via coma aberration. Thus, the light distribution pattern 70 becomes a light distribution pattern that extends outwards and downwards from the lower end of the light distribution pattern 80 in region 70d. It should be noted that, for example, when the light distribution pattern 70 is a high-beam light distribution pattern, the meta-region, when viewed from the meta-lens 30 in a horizontal direction, can extend the divergence angle of the light L forming region 70c in a direction away from the reference axis C of the light distribution pattern 70, i.e., upward from that optical axis, through coma aberration. Thus, the light distribution pattern 70 becomes a light distribution pattern that extends outward from the upper end of the light distribution pattern 80 in region 70c, i.e., upward. This meta-region generates coma aberration that causes the point image in the light distribution pattern 70 to extend from the inside of the light distribution pattern 70 towards the outside of the light distribution pattern 70 in the vertical direction, thereby changing the phase distribution of the light L transmitted through the meta-region. Therefore, compared to the case where no coma aberration is generated, the meta-region extends the divergence angle of the light L in the vertical direction of the light distribution pattern in a direction away from the reference axis C of the light distribution pattern 70, and compared to the light distribution pattern 80, it also extends the light distribution pattern 70 in the vertical direction, which is the height direction of the light distribution pattern. In this situation, the driver of the vehicle can easily visually identify objects such as guide signs and road surfaces.

[0143] Furthermore, the element region extends the divergence angle of light L diffused from the left and right sides of the light distribution pattern 70 formed in the left-right direction and diffused from the reference axis C of the light distribution pattern 70 in the left-right direction than the divergence angle of light L diffused from the right and left sides of the light distribution pattern 70 formed in the up-down direction and diffused from the reference axis C of the light distribution pattern 70 in the up-down direction. Therefore, the extension at each of the left and right ends of the light distribution pattern 70 is greater than the extension at the bottom end of the light distribution pattern 70. While the amount of light emitted from the element lens 30 remains constant, the left-right extension of the light distribution pattern 70 is greater than its up-down extension. Thus, the driver's field of vision is ensured to be wider in the left-right direction than in the up-down direction by this light distribution pattern. Moreover, compared to the case where the extension at each of the left and right ends of the light distribution pattern 70 is no greater than the extension at the bottom end of the light distribution pattern 70, the driver of the vehicle can more easily visually identify objects such as pedestrians and road signs.

[0144] It should be noted that the meta-region may not extend the divergence angle of the light L forming the lower end of the light distribution pattern 70, or it may extend the divergence angle of the light L forming the upper end of the light distribution pattern 70. Alternatively, the meta-region may extend the divergence angle of the light L forming the vertical direction of the light distribution pattern 70 more than the divergence angle of the light L forming the horizontal direction of the light distribution pattern 70. Thus, the vertical direction of the light distribution pattern 70 is extended more than the horizontal direction of the light distribution pattern 70.

[0145] (Sixth Implementation Method)

[0146] Next, the sixth embodiment of the present invention will be described. It should be noted that, unless otherwise specified, structural elements that are the same as or equivalent to those in the first embodiment will be labeled with the same reference numerals in the accompanying drawings, and repeated descriptions will be omitted. In this embodiment, the structure of the element lens 30 differs from that in the first embodiment.

[0147] like Figure 1 As shown, for example, when a vehicle is driving uphill during the day, light such as sunlight sometimes enters the interior of the frame 10 of the vehicle lamp 1 from the outside via the front cover 12. The light entering the interior of the frame 10 is incident on the main surface 32s in the element lens 30, and then emitted from the main surface 31s toward the light source 20. Sometimes, it travels in the opposite direction to the light L from the light source 20 and is focused onto the light source 20. Due to the focusing of the light, the light source 20 may deteriorate. In this embodiment, the element region suppresses light focusing by curvature, which will be explained below. In addition, it is assumed here that the longest wavelength of visible light contained in the light is 660nm and the shortest wavelength of infrared light contained in the light is 1000nm, and the wavelength ratio of each light is 1:1.5 in this case.

[0148] Curvature refers to the force by which a refracting lens or element bends the light passing through it. The smaller the curvature, the smaller the bending angle of the light passing through it, and the more the light is focused.

[0149] Next, the curvature of a refractive lens will be explained. Acrylic or polycarbonate can be cited as the main materials for refractive lenses. The refractive index of an acrylic lens is 1.489 for visible light and 1.483 for infrared light. Conversely, the refractive index of a polycarbonate lens is 1.579 for visible light and 1.568 for infrared light.

[0150] Since the focal length of a refractive lens is inversely proportional to its refractive index (-1), its curvature is directly proportional to its refractive index (-1). Therefore, in a refractive lens made of acrylic, if the curvature of the lens that bends visible light is set to 1, the curvature of the lens that bends infrared light is approximately 0.98. Similarly, in a refractive lens made of polycarbonate, if the curvature of the lens that bends visible light is set to 1, the curvature of the lens that bends infrared light is approximately 0.98.

[0151] Therefore, regardless of whether it's acrylic or polycarbonate resin, the curvature of the refractive lens that bends infrared light is approximately 0.98 times that of the refractive lens that bends visible light. In this case, the curvature of the refractive lens that bends infrared light is approximately the same as that of the refractive lens that bends visible light, so the bending angle of infrared light is approximately the same as that of visible light, and the focal length of the refractive lens that bends infrared light is approximately the same as that in the case of visible light. Therefore, the refractive lens easily focuses infrared light.

[0152] Next, the curvature of the meta-region will be explained. The phase distribution of light transmitted through the meta-region varies according to the meta-region as described above. Since phase represents the lead or lag of the wavefront of light, light with a phase distribution has a slope relative to the wavefront. Since light travels in a direction perpendicular to the wavefront, according to the above effect, the wavefront of light whose phase is modulated in the meta-region tilts in a direction different from its original direction of travel, and the direction of light travel is bent. Therefore, the curvature of the meta-region that bends the light transmitted through it is approximately proportional to the product of the phase modulation amount of the light and the wavelength of the light. As described above, the meta-region changes the phase distribution of light transmitted through it. This phase distribution varies according to the arrangement of the plurality of units 33, the size and shape of the nanostructures 35 in each unit 33, etc. Through these adjustments, the meta-region changes the phase distribution of light transmitted through it. In addition, in the meta-region, this change causes a change in the phase modulation amount of the light. In the meta-region of this embodiment, through the above adjustments, the ratio of the phase modulation amount of visible light to the phase modulation amount of infrared light is 4:1, and the ratio of the longest wavelength of visible light to the shortest wavelength of infrared light is 1:1.5. Therefore, in this case, the ratio of the curvature of the meta-region that bends visible light to the curvature of the meta-region that bends infrared light is 1:0.3.

[0153] In this way, the phase distribution of light transmitted through the element region changes through the aforementioned adjustment. This change alters the phase modulation amount of the light, resulting in a smaller curvature of the element region for infrared light than for visible light. Since the curvature of the element region for infrared light is smaller than that for visible light, the bending angle of the infrared light is smaller than that of the visible light, thus suppressing the focusing of infrared light. Therefore, the element region focuses visible light onto the light source 20, suppressing the focusing of infrared light and allowing infrared light to pass through.

[0154] Next, a comparison will be made between the curvature of the element region that bends infrared light and the curvature of the refractive lens that bends infrared light. If the two are compared based on their respective curvatures that bend visible light, the curvature of the element region that bends infrared light is smaller than the curvature of the refractive lens that bends infrared light, as adjusted as described above. Therefore, the bending angle of infrared light based on the element region is smaller than the bending angle of infrared light based on the refractive lens. Assuming the focal length of the refractive lens that bends visible light is 50 mm, the focal length of the refractive lens that bends infrared light deviates from the focal length that bends visible light by approximately 0.1 mm based on the aforementioned ratio of the curvatures of the refractive lenses. Conversely, assuming the focal length of the element lens 30 containing the element region that bends visible light is the same as above (50 mm), the focal length of the element lens 30 containing the element region that bends infrared light deviates from the focal length of the element lens 30 containing the element region that bends visible light by approximately 100 mm based on the aforementioned ratio of the curvatures of the element region. Therefore, if the degree of curvature that causes infrared light to bend is reduced compared to that of a refractive lens, the bending angle of infrared light based on the element region is smaller than that based on the refractive lens. Thus, the element region can suppress the focusing of infrared light compared to a refractive lens.

[0155] It should be noted that even if the focal length of the element lens 30 relative to infrared light is shifted by approximately 10% from the focal length of the element lens 30 relative to visible light, the element region can still suppress the focusing of infrared light. In this case, the ratio of the curvature of the element region that bends visible light to the curvature of the element region that bends infrared light is approximately 1:0.9, even if the curvature of the element region that bends infrared light is approximately 0.9 times that of the element region that bends visible light. The following explanation addresses the ratio of the phase modulation amount of visible light to the phase modulation amount of infrared light when the ratio of the curvature of the element region that bends visible light to the curvature of the element region that bends infrared light is approximately 1:0.9.

[0156] Here, it is assumed that the ratio of the phase modulation of visible light to the phase modulation of infrared light is 1:X. The wavelength ratio of visible light and infrared light is, as described above, 1:1.5. Furthermore, the ratio of the curvature of the element region that bends visible light to the curvature of the element region that bends infrared light, approximately 1:0.9 as described above, is suitable. As mentioned above, the curvature of the element regions that bend visible light and infrared light respectively is approximately proportional to the product of the phase modulation and the wavelength. Therefore, X is 0.6, and the phase modulation of infrared light is 0.6 times that of visible light. It should be noted that it is preferable that the curvature of the element region that bends infrared light is less than 0.9 times that of the element region that bends visible light; therefore, the phase modulation of infrared light is less than 0.6 times that of visible light.

[0157] As described above, the curvature of the refractive lens that bends infrared light is approximately 0.98 times that of the refractive lens that bends visible light, and the curvature of the elemental region that bends infrared light is less than 0.9 times that of the elemental region that bends visible light. If we compare the curvature of the elemental region that bends infrared light with that of the refractive lens that bends infrared light, using the individual curvatures that bend visible light as a reference, the curvature of the elemental region that bends infrared light is smaller than that of the refractive lens. Therefore, compared to the refractive lens, the elemental region can suppress the focusing of infrared light.

[0158] Figure 15 This is a graph showing the relationship between the diameter of the nanostructure 35 and the phase modulation of visible light with the longest wavelength of 660 nm and infrared light with the shortest wavelength of 1000 nm. The solid line represents the relationship between the diameter of the nanostructure 35 and the phase modulation of visible light, and the dashed line represents the relationship between the diameter of the nanostructure 35 and the phase modulation of infrared light.

[0159] In order to focus visible light by having the element lens 30 function as a lens relative to visible light, it is important that the phase modulation amount of the visible light is in the range of 0-2π (rad). Therefore, the shape of the nanostructure 35 is cylindrical, and the diameter of the cylindrical nanostructure 35 can be within the range corresponding to this range. For example, it is preferable that the diameter of the nanostructure 35 is from 0 nm to 250 nm. In this embodiment, the diameter range of the nanostructure 35 is more preferably from 100 nm to 250 nm, for example, and a plurality of nanostructures 35 with diameters within this range are disposed. Within the range of the phase modulation amount of visible light, the phase modulation amount of infrared light is 0.5π radians. Therefore, the element region suppresses the focusing of infrared light and allows infrared light to pass through.

[0160] It should be noted that when the shape of the nanostructure 35 is cylindrical, the longer the wavelength of the focused light, Figure 15The smaller the slope of the curve shown, the wider the range of diameters of the nanostructure 35.

[0161] As described above, the meta-region of this embodiment changes the phase distribution of light transmitted through the meta-region, and the curvature of the meta-region that bends the infrared light contained in the light transmitted through the meta-region is smaller than the curvature of the meta-region that bends the visible light contained in the light transmitted through the meta-region.

[0162] In the vehicle lamp 1 of this embodiment, as described above, the element regions change the phase distribution of light transmitted through them. This phase distribution varies depending on the arrangement of the plurality of units 33, the size and shape of the nanostructures 35 in each unit 33, etc. Therefore, by adjusting them, the element regions change the phase distribution of light transmitted through them, making the curvature of the element regions that bend the infrared light contained in the light smaller than the curvature of the element regions that bend the visible light contained in the light. The smaller the curvature, the smaller the bending angle of the light transmitted through the element regions, and the more the light focusing is suppressed. Therefore, for example, even if sunlight enters the interior of the frame 10 of the vehicle lamp 1 from the outside of the vehicle lamp 1 via the front cover 12, in this vehicle lamp 1, since the bending angle of the infrared light contained in the sunlight is smaller than the bending angle of the visible light in the sunlight due to the aforementioned curvature, the element regions can suppress the focusing of infrared light traveling toward the light source 20 compared to a projection lens. If the focusing of infrared light is suppressed, the degradation of the light source section 20 caused by the focusing of infrared light can be suppressed compared with the projection lens.

[0163] Furthermore, if the degradation of the light source section 20 is suppressed, the effect of the degradation of the light source section 20 on the light L emitted from the light source section 20 can be suppressed, and a predetermined light distribution pattern can be projected.

[0164] Furthermore, by setting the shape of the nanostructure 35 to a cylindrical shape, the visible light from the light source 20 can be effectively bent even if the visible light is randomly polarized.

[0165] Taking the sixth embodiment as an example, a vehicle lamp 1 equipped with a primary lens 30 is described. This primary lens 30 has a primary region where the curvature of the infrared light is smaller than that of the visible light. However, the vehicle lamp 1 is not limited to this. The following describes a variation of the sixth embodiment.

[0166] In the vehicle lamp 1 of the sixth embodiment, sunlight was used as the light incident from the outside of the vehicle lamp 1 into the inside of the vehicle lamp 1. However, this light is not limited to sunlight; any infrared light and visible light incident from the outside of the vehicle lamp 1 into the inside of the vehicle lamp 1 is acceptable. Furthermore, as an example of a wavelength ratio of 1:1.5, the longest wavelength of visible light is assumed to be 660 nm and the shortest wavelength of infrared light is assumed to be 1000 nm. However, as long as the ratio is 1:1.5, the wavelengths of visible light and infrared light are not particularly limited.

[0167] The light distribution pattern 70 projected from the vehicle lamp 1 can be a light distribution pattern for low beam or a light distribution pattern for high beam.

[0168] (Seventh Implementation)

[0169] Next, the seventh embodiment of the present invention will be described. It should be noted that, unless otherwise specified, the same reference numerals are used for structural elements that are identical or equivalent to those in the first embodiment, and repeated descriptions are omitted. In this embodiment, the structures of the light source 20 and the element lens 30 differ from those in the first embodiment.

[0170] Figure 16 Is with Figure 1 Similarly, a diagram of the vehicle lamps in this embodiment is shown. Additionally, Figure 17 This is a schematic diagram showing the beam distribution of light emitted from the light source unit 20 in this embodiment and the transmittance distribution of light from the element lens 30. It should be noted that... Figure 17 In the diagram, the horizontal axis represents wavelength, the first vertical axis represents relative intensity based on maximum intensity, and the second vertical axis represents relative transmittance based on maximum transmittance. Additionally, in... Figure 17 In the diagram, thin lines represent the spectral distribution, and thick lines represent the transmittance distribution. In this embodiment, the wavelength region of the light L emitted from the light source unit 20 is approximately 380 nm to 780 nm. Furthermore, as... Figure 17As shown, the spectral distribution 90 of the light L has four peaks 91, 92, 93, and 94. The wavelengths 91w, 92w, 93w, and 94w of each peak 91, 92, 93, and 94 increase in length in the order of 91w, 92w, 93w, and 94w. Wavelength 91w is approximately 410 nm, wavelength 92w is approximately 460 nm, wavelength 93w is approximately 530 nm, and wavelength 94w is approximately 620 nm. Therefore, among the wavelengths 91w, 92w, 93w, and 94w of the multiple peaks 91, 92, 93, and 94, wavelength 91w is the shortest, and wavelength 94w is the longest. Furthermore, the wavelengths 91w, 92w, 93w, and 94w of these peaks are contained within the wavelength region of visible light. It should be noted that the spectral distribution 90 may also have peaks not contained within the wavelength region of visible light. Furthermore, the number of peaks in the spectral distribution 90 is not limited; for example, the spectral distribution 90 may not have any peaks. Additionally, the light L emitted from the light source 20 is emitted from multiple light-emitting elements 21, therefore the spectral distribution of the light emitted from each light-emitting element 21 is related to... Figure 17 The spectral distribution shown is approximately the same.

[0171] For example, when vehicles are driving uphill during the day, such as... Figure 16 As shown, sunlight L2 sometimes enters the lamp chamber R through the front cover 12 and shines on the light source unit 20 through the element lens 30. In this embodiment, the element lens 30 reduces the divergence angle of the light L from the light source unit 20 that passes through the element lens 30. Therefore, the sunlight L2 that passes through the element lens 30 is focused and then shines on the light source unit 20.

[0172] Figure 18 This is a diagram that roughly illustrates the spectral distribution of sunlight L2 near the Earth's surface and the transmittance distribution of light from the element lens 30 in this embodiment. It should be noted that... Figure 18 In the diagram, the horizontal axis represents wavelength, the vertical axis represents relative intensity based on maximum intensity, and the second vertical axis represents relative transmittance based on maximum transmittance. Additionally, in... Figure 18 In the diagram, thin lines represent the spectral distribution, and thick lines represent the transmittance distribution in the range of 300 nm to 2500 nm. For example... Figure 18 As shown, sunlight L2 includes both visible light and infrared light.

[0173] Furthermore, in a meta-lens having meta-regions containing units comprising nanostructures, a phenomenon sometimes occurs where the transmittance of light of a specific wavelength is extremely low compared to other wavelengths; it is known that there are multiple such specific wavelengths. These specific wavelengths are the wavelengths at which the transmittance of light in the meta-lens reaches its peak, and are called resonant wavelengths. These resonant wavelengths are determined based on the size and shape of the nanostructures in each unit, the refractive index of the material constituting the nanostructures, etc. In this embodiment, as... Figure 18 As shown, among the multiple resonant wavelengths in the element lens 30, the longest resonant wavelength 30w1 and the second longest resonant wavelength 30w2 are contained within the range of 800 nm to less than 2400 nm, and the second longest resonant wavelength 30w2 is contained within the range of 800 nm to less than 900 nm. Specifically, the resonant wavelength 30w1 is approximately 1700 nm, and the resonant wavelength 30w2 is approximately 850 nm. Additionally, the third longest resonant wavelength 30w3 is approximately 425 nm. It should be noted that... Figure 18 The text describes the single-dotted lines SL1, SL2, and SL3 representing these resonant wavelengths 30ω1, 30ω2, and 30ω3. Additionally, Figure 17 The text describes a single-dotted line SL3 representing the resonant wavelength of 30 Ω. For example... Figure 17 As shown, the resonant wavelength 30w3 is contained within the wavelength region of the light L emitted from the light source 20, and the light L from the light source 20 contains light with the same wavelength as the resonant wavelength 30w3. However, this resonant wavelength 30w3 is different from the wavelengths 91w, 92w, 93w, and 94w of the peaks 91, 92, 93, and 94 in the spectral distribution 90 of the light L. Therefore, all of the multiple resonant wavelengths in the element lens 30 are different from the wavelengths of these peaks. In addition, the resonant wavelength 30w3 is the wavelength between the wavelengths 91w and 92w of adjacent peaks 91 and 92. It should be noted that it is acceptable as long as at least one resonant wavelength in the element lens 30 is 800nm ​​or more and less than 2400nm. For example, the longest resonant wavelength can be the resonant wavelength 30w2, and the second longest resonant wavelength can be the resonant wavelength 30w3.

[0174] As described above, in the vehicle lamp 1 of this embodiment, at least one resonant wavelength in the element lens 30 is 800 nm or more and less than 2400 nm. Furthermore, as... Figure 18As shown, sunlight near the Earth's surface typically includes light with wavelengths ranging from 800 nm to 2400 nm. Therefore, according to the vehicle lamp 1 of this embodiment, when sunlight L2 shines on the light source unit 20 through the element lens 30, compared to the case where the element lens 30 is a projection lens, the amount of light with wavelengths from 800 nm to 2400 nm in the sunlight L2 that irradiates the light source unit 20 can be reduced. Therefore, according to the vehicle lamp 1 of this embodiment, compared to the above-described case, the amount of heating of the light source unit 20 caused by sunlight L2 can be reduced, and the degradation of the light source unit 20 caused by sunlight L2 can be suppressed.

[0175] In the vehicle lamp 1 of this embodiment, the resonant wavelength 30W2 is contained in the range of 800nm ​​or more and less than 900nm. For example... Figure 18 As shown, the intensity of sunlight L2 near the Earth's surface typically tends to decrease with increasing wavelength in the wavelength region above 800 nm. It should be noted that the spectral distribution 100 of sunlight L2 has multiple valleys where the intensity decreases sharply. The minimum intensity of such a valley is, for example, less than 50% of the intensity near that valley. Such valleys tend to be located in the range between 800 nm and 900 nm. Therefore, by adopting the structure described above, it is easy to reduce the amount of heating of the light source section 20 caused by sunlight L2 when it passes through the element lens 30 and irradiates the light source section 20. It should be noted that multiple resonant wavelengths may be included in the range of 800 nm and 900 nm, or they may not be included in this range.

[0176] In the vehicle lamp 1 of this embodiment, the spectral distribution 90 of the light L emitted from the light source 20 has four peaks 91, 92, 93, and 94. The wavelengths 91ω, 92ω, 93ω, and 94 of the multiple resonant wavelength peaks 91, 92, 93, and 94 are different. The wavelengths of light at the peaks 91, 92, 93, and 94 of the spectral distribution 90 tend to have a significant impact on the hue of the light emitted from the vehicle lamp. Therefore, according to the vehicle lamp 1 of this embodiment, the reduction in transmittance of light with wavelengths that have a significant impact on the hue of the emitted light in the element lens 30 can be suppressed, and light with the desired hue can be emitted.

[0177] It should be noted that, from the viewpoint of emitting light of the desired hue, the spectral distribution 90 has multiple peaks, as long as the multiple resonant wavelengths are different from the individual wavelengths of the multiple peaks. For example, the multiple resonant wavelengths can also be included in the wavelength region of the light L emitted from the light source 20. In this embodiment, the resonant wavelength 30w3 included in the wavelength region of the light L from the light source is the wavelength between the wavelengths 91w and 92w of adjacent peaks 91 and 92. In this case, the resonant wavelength 30w3 is preferably the same as the wavelength of the light L with the lowest intensity between adjacent peaks 91 and 92. With such a structure, compared to the case where the wavelength of light other than the light with the lowest intensity between peaks 91 and 92 is the same as the resonant wavelength 30w3, the reduction in the amount of emitted light can be suppressed.

[0178] Furthermore, from the viewpoint of suppressing the reduction in the amount of emitted light, it is preferable that the ratio of the intensity of the light with a resonant wavelength of 30ω3 from the light source unit 20 to the maximum intensity of the overall spectral distribution 90 is 0.1 or less. With this structure, compared to the case where this ratio exceeds 0.1, the reduction in the amount of emitted light can be suppressed. Additionally, with this structure, compared to the case where this ratio exceeds 0.1, light of the desired hue can be emitted more easily. It should be noted that this ratio is more preferably zero. However, this ratio may also exceed 0.1. Furthermore, from the viewpoint of suppressing the reduction in the amount of emitted light, it is preferable that the ratio of the amount of light with a resonant wavelength of 30ω3 from the light source unit 20 to the total amount of light from the light source unit 20 is less than 4%.

[0179] Furthermore, as described above, the element lens 30 of the vehicle lamp 1 of this embodiment reduces the divergence angle of the light L from the light source 20 transmitted through the element lens 30. Therefore, sunlight L2 transmitted through the element lens 30 is focused and illuminates the light source 20, thus the light source 20 is more likely to deteriorate compared to the case where the element lens 30 increases the divergence angle of the light L from the light source 20. Therefore, the vehicle lamp 1 of this embodiment is particularly useful in reducing the divergence angle of the light L from the light source 20.

[0180] Furthermore, the vehicle lamp 1 of this embodiment includes a frame 10 that houses the light source unit 20 and the element lens 30. In such a vehicle lamp 1, depending on the angle of incidence of sunlight L2 onto the element lens 30, sunlight L2 passing through the element lens 30 may sometimes irradiate the inner surface of the frame 10. According to the vehicle lamp 1 of this embodiment, when sunlight L2 passes through the element lens 30 and irradiates the frame 10, compared to the case where the element lens 30 is a projection lens, the amount of light with wavelengths from 800 nm to 2400 nm in sunlight L2 irradiating the inner surface of the frame 10 can be reduced.

[0181] Taking the seventh embodiment as an example, a vehicle lamp 1 having at least one element lens 30 with a resonant wavelength of 800 nm or more and less than 2400 nm has been described. However, such a vehicle lamp 1 is not limited to this. Modifications of the seventh embodiment will be described below.

[0182] For example, in the seventh embodiment, a primary lens 30 with multiple resonant wavelengths included in the wavelength region of the light L emitted from the light source 20 is described as an example. However, all of the multiple resonant wavelengths in the primary lens 30 may not be included in the wavelength region of the light L emitted from the light source 20. In other words, the light L emitted from the light source 20 may not include all of the multiple resonant wavelengths in the primary lens 30. By adopting such a structure, light of a desired hue can be emitted compared to the case where at least one resonant wavelength is included in the wavelength region of the light L emitted from the light source 20.

[0183] Furthermore, in the seventh embodiment, an example of a primary lens 30 is described, where all of the multiple resonant wavelengths are different from the wavelengths of each of the multiple peaks. However, from the viewpoint of emitting light of the desired hue, it is sufficient that the multiple resonant wavelengths are different from the wavelengths of each of the multiple peaks; for example, a specific resonant wavelength may be the same as the wavelength of a certain peak. It should be noted that, from the viewpoint of emitting light of the desired hue, it is preferable that all of the multiple resonant wavelengths are different from the wavelengths of each of the multiple peaks.

[0184] Furthermore, from the viewpoint of emitting light of the desired hue, it is preferable that the transmittance distribution of the light from the element lens 30, with a relative transmittance of 80% or less based on the maximum transmittance of the light L transmitted through the element lens 30 from the light source section 20, includes multiple consecutive resonant wavelength regions containing a single resonant wavelength, at least one of which differs from the respective wavelength of each of the multiple peaks. In this case, it is more preferable that all of these resonant wavelength regions differ from the respective wavelength of each of the multiple peaks. It should be noted that, more preferably, when the transmittance distribution of the light from the element lens 30, with a relative transmittance of 60% or less based on the maximum transmittance of the light L transmitted through the element lens 30 from the light source section 20, includes multiple consecutive resonant wavelength regions containing a single resonant wavelength, at least one of these resonant wavelength regions differs from the respective wavelength of each of the multiple peaks. In this case, it is more preferable that all of these resonant wavelength regions differ from the respective wavelength of each of the multiple peaks. Furthermore, more preferably, when the transmittance distribution of the light from the element lens 30 is 40% or less based on the maximum transmittance of the light L transmitted through the element lens 30 from the light source section 20, and includes multiple consecutive resonant wavelength regions containing a resonant wavelength, at least one of these resonant wavelength regions differs from the respective wavelengths of the multiple peaks. In this case, it is more preferable that all of these resonant wavelength regions differ from the respective wavelengths of the multiple peaks.

[0185] It should be noted that, from the viewpoint of easily emitting light of the desired hue, unlike the seventh embodiment, for example, the longest resonant wavelength in the element lens can be shorter than the shortest wavelength among the peak wavelengths of the spectral distribution of light from the light source. That is, the light source and element lens can also be configured in this manner. Hereinafter, refer to... Figure 19 Such variations will be described. It should be noted that, unless otherwise specified, the same reference numerals are used for structural elements that are the same as or equivalent to those in the seventh embodiment, and repeated descriptions are omitted. Figure 19 Is with Figure 17Similarly, diagrams showing the beam distribution 90 of the light emitted from the light source 20 in the fifth modification and the transmittance distribution of the light from the element lens 30 are also shown. In this modification, the resonant wavelength of the element lens 30 is different from the resonant wavelength in the above embodiment. Furthermore, the beam distribution 90 is the same as the beam distribution 90 in the above embodiment, but it may also be different. Additionally, the longest resonant wavelength 30w1 in the element lens 30 is included in the wavelength region of the light L from the light source 20. However, as described above, this longest resonant wavelength 30w1 is shorter than the shortest wavelength 91w among the wavelengths 91w, 92w, 93w, and 94w of each of the plurality of peaks 91, 92, 93, and 94. Therefore, all of the plurality of resonant wavelengths in the element lens 30 are shorter than wavelength 91w. According to the vehicle lamp 1 of this modification, compared to the case where the longest resonant wavelength 30w1 in the element lens 30 is longer than the aforementioned shortest wavelength 91w, it is possible to suppress the decrease in transmittance of wavelengths that have a large impact on the hue of the emitted light in the element lens. Therefore, according to the vehicle lamp 1 of this modified example, compared with the above-described case, it is possible to easily emit light of the desired hue. It should be noted that, from the viewpoint of easily emitting light of the desired hue, the longest resonant wavelength 30w1 in the element lens 30 can also be shorter than the shortest wavelength in the wavelength region of the light L from the light source section 20. Furthermore, from this viewpoint, the longest resonant wavelength 30w1 in the element lens 30 can also be shorter than the shortest wavelength in the wavelength region of visible light, for example, 380 nm. That is, the element lens 30 can also be configured in this manner.

[0186] (Eighth Implementation)

[0187] Next, the eighth embodiment of the present invention will be described. It should be noted that, unless otherwise specified, the same reference numerals are used for structural elements that are the same as or equivalent to those in the first embodiment, and repeated descriptions are omitted. In this embodiment, the structures of the light source 20 and the element lens 30 differ from those in the first embodiment.

[0188] Figure 20 This is a schematic diagram showing the beam distribution of light emitted from the light source unit 20 in this embodiment and the transmittance distribution of light from the element lens 30. It should be noted that... Figure 20 In the diagram, the horizontal axis represents wavelength, the first vertical axis represents relative intensity based on maximum intensity, and the second vertical axis represents relative transmittance based on maximum transmittance. Additionally, in... Figure 20 In the diagram, thin lines represent spectral distribution, and thick lines represent transmittance. For example... Figure 20As shown, in this embodiment, the spectral distribution 90 has four peaks 91, 92, 93, and 94. The wavelengths 91w, 92w, 93w, and 94w of each peak 91, 92, 93, and 94 increase in the order of wavelength 91w, 92w, 93w, and 94w. Wavelength 91w is approximately 410 nm, wavelength 92w is approximately 460 nm, wavelength 93w is approximately 530 nm, and wavelength 94w is approximately 620 nm. Therefore, among the wavelengths 91w, 92w, 93w, and 94w of the multiple peaks 91, 92, 93, and 94, wavelength 91w is the shortest, and wavelength 94w is the longest. Furthermore, the wavelengths 91w, 92w, 93w, and 94w of these peaks 91, 92, 93, and 94 are contained within the wavelength region of visible light. It should be noted that the spectral distribution 90 may also have peaks not contained within the wavelength region of visible light. Furthermore, the light L emitted from the light source 20 is light emitted from multiple light-emitting elements 21, therefore the spectral distribution of the light emitted from each light-emitting element 21 is different from that of the light source 20. Figure 20 The spectral distribution shown is approximately the same.

[0189] In this embodiment, the nanostructure 35 is cylindrical in shape, with a diameter ratio of... Figure 20 The wavelength 94w of peak 94 shown is smaller than that of peak 91, 92, 93, and 94. It should be noted that the shape of nanostructure 35 is not particularly restricted, as long as the width of nanostructure 35 is smaller than the longest wavelength 94w of peaks 91, 92, 93, and 94.

[0190] As explained in the seventh embodiment, the resonant wavelength in the element lens is determined based on the size and shape of the nanostructure in each unit, the refractive index of the material constituting the nanostructure, etc. In this embodiment, all of the multiple resonant wavelengths in the element lens 30 are different from the wavelengths 91w, 92w, 93w, and 94w of each peak 91, 92, 93, and 94. Furthermore, as... Figure 20 As shown, among the multiple resonant wavelengths in the element lens 30, the longest resonant wavelength 30w1 is longer than the wavelength 94w, and the second longest resonant wavelength 30w2 is contained within the wavelength region of the light L from the light source section 20. It should be noted that... Figure 20The diagram shows dashed lines SL1 and SL2 representing these resonant wavelengths 30w1 and 30w2. In this embodiment, the second longest resonant wavelength 30w2 exceeds the shortest wavelength 91w among wavelengths 91w, 92w, 93w, and 94w, but is less than the longest wavelength 92w. If the resonant wavelengths do not include those exceeding the shortest wavelength 91w and less than the longest wavelength 94w, the design of the size, shape, and arrangement of the nanostructures 35 in each unit 33 tends to become complex. Therefore, in this embodiment, this design complexity can be suppressed. It should be noted that the resonant wavelengths exceeding 91w and less than 94w may also not be included in the multiple resonant wavelengths. Furthermore, in this embodiment, the wavelength of the light from the light source 20, which has the lowest intensity between adjacent peaks 92 and 93 among peaks 91, 92, 93, and 94, is the same as the second longest resonant wavelength 30w2. It should be noted that the wavelength of light from the light source section 20, which has the lowest intensity between peaks 92 and 93, may be different from the resonant wavelength 30w2. Furthermore, the resonant wavelength 30w2 can be the wavelength between peaks 91 and 92, or it can be the wavelength between peaks 93 and 94. The wavelength of light from the light source section 20, which has the lowest intensity between these peaks, may be the same as or different from the resonant wavelength 30w2. Additionally, the plurality of resonant wavelengths in the element lens 30 may include multiple resonant wavelengths that exceed the shortest wavelength 91w and are less than the longest wavelength 94w.

[0191] In the light-emitting module of Patent Document 3 described above, the hue of the emitted light can be adjusted by appropriately selecting the wavelength of the light emitted from the LED or the phosphor. Therefore, it is believed that by using such a light-emitting module in the light source section of a vehicle lamp, light of a desired hue can be emitted from the vehicle lamp. In the vehicle lamp 1 of this embodiment, as described above, the spectral distribution 90 of the light emitted from the light source section 20 has multiple peaks 91, 92, 93, and 94. Therefore, according to the vehicle lamp 1 of this embodiment, compared with the case where the spectral distribution 90 has only one peak, the hue of the emitted light can be made to be the desired hue. In addition, the multiple resonant wavelengths in the element lens 30 of this embodiment are different from the respective wavelengths 91w, 92w, 93w, and 94w of the multiple peaks 91, 92, 93, and 94. The light of the respective wavelengths 91w, 92w, 93w, and 94w of the multiple peaks 91, 92, 93, and 94 has a significant impact on the hue of the light emitted from the vehicle lamp 1. Therefore, the vehicle lamp 1 according to this embodiment can suppress the decrease in the transmittance of light with wavelengths of 91w, 92w, 93w, and 94w that have a significant impact on the color tone of the emitted light in the element lens 30, and can emit light with the desired color tone.

[0192] In the vehicle lamp 1 of this embodiment, the multiple resonant wavelengths in the element lens 30 include a resonant wavelength 30w2 that exceeds the shortest wavelength 91w and is less than the longest wavelength 94w among the wavelengths 91w, 92w, 93w, and 94w of the multiple peaks 91, 92, 93, and 94. Furthermore, the wavelength of light from the light source section 20, which has the lowest intensity between adjacent peaks 92 and 93, is the same as this resonant wavelength 30w2. With this structure, compared to the case where the wavelength of light other than the light with the lowest intensity between peaks 92 and 93 is the same as the resonant wavelength 30w2, the reduction in the amount of emitted light can be suppressed.

[0193] The vehicle lamp 1, which includes a light source section 20 having multiple peaks in the spectral distribution of emitted light and multiple element lenses 30 having resonant wavelengths different from the wavelengths of these multiple peaks, has been described using the eighth embodiment as an example. However, such a vehicle lamp 1 is not limited to this. Modifications to the eighth embodiment will be described below.

[0194] For example, in the eighth embodiment, a light source unit 20 emitting light L with four peaks 91, 92, 93, and 94 via a spectral distribution 90 is described as an example. However, the light source unit 20 can be any structure that emits light with multiple peaks via a spectral distribution. For example, the light source unit 20 may have a light-shielding plate that blocks a portion of the light emitted from the light-emitting element 21, or it may have a reflective plate that reflects at least a portion of the light emitted from the light-emitting element 21. Furthermore, there is no particular limitation on the number of peaks in the spectral distribution 90 of the light L emitted from the light source unit 20. For example, the light source unit 20 may also emit light with multiple peaks via a spectral distribution 90. Figure 21 The structure of the light in the spectral distribution is shown. It should be noted that... Figure 21 Is with Figure 20 Similarly, diagrams showing the beam distribution of light emitted from the light source section in the sixth modified example and the transmittance distribution of light from the element lens are also shown. Hereinafter, the beam distribution of light emitted from the light source section will be... Figure 21 The sixth variation of the spectral distribution shown will be described. It should be noted that, unless otherwise specified, the same reference numerals are used for structural elements that are the same as or equivalent to those in the eighth embodiment, and repeated descriptions are omitted.

[0195] In this variation, the spectral distribution 90 has two peaks 91 and 92. The wavelength 91w of peak 91 is shorter than the wavelength 92w of peak 92. In this variation, wavelength 91w is approximately 460 nm and wavelength 92w is approximately 570 nm. Furthermore, the intensity of peak 91 is higher than that of peak 92, and is the highest in the overall spectral distribution 90. Additionally, the diameter of the nanostructure 35 in this variation is smaller than the wavelength 92w of peak 92. Furthermore, all of the multiple resonant wavelengths in the elemental lens 30 of this variation are different from the respective wavelengths 91w and 92w of the two peaks 91 and 92. Therefore, the vehicle lamp 1 of this variation, like the first embodiment, is able to emit light of a desired hue compared to the case where at least one of the multiple resonant wavelengths and the wavelengths 91w and 92w of a certain peak 91 and 92 are the same.

[0196] Furthermore, the second longest resonant wavelength 30w2 exceeds the shortest wavelength 91w among these wavelengths 91w and 92w, but is less than the longest wavelength 92w. That is, among the multiple resonant wavelengths, there is a resonant wavelength 30w2 that exceeds the shortest wavelength 91w among these wavelengths 91w and 92w, but is less than the longest wavelength 92w. Therefore, according to this modified example, similar to the first embodiment, it is possible to suppress the design from becoming complicated, such as the size and shape of the nanostructures 35 in each unit 33 and the arrangement of the units 33.

[0197] Furthermore, in this modified example, the wavelength of the light from the light source section 20, which has the lowest intensity between adjacent peaks 91 and 92, is the same as the resonant wavelength 30w2. Therefore, according to this modified example, similar to the eighth embodiment, compared to the case where the wavelength of light other than the light with the lowest intensity between peaks 91 and 92 is the same as the resonant wavelength 30w2, the reduction in the amount of emitted light can be suppressed.

[0198] Furthermore, in this modified example, the plurality of resonant wavelengths in the element lens 30 include a resonant wavelength 30w2, which is contained within the wavelength region of the light L from the light source section 20. The maximum intensity of the overall spectral distribution 90 is the intensity of the peak 91, and the ratio of the intensity of the light with resonant wavelength 30w2 from the light L from the light source section 20 to this intensity is 0.1 or less. Therefore, according to this modified example, compared to the case where the ratio exceeds 0.1, the reduction in the amount of emitted light can be suppressed. In addition, with such a structure, compared to the case where the ratio exceeds 0.1, light of the desired hue can be emitted more easily. It should be noted that this ratio is more preferably zero. However, this ratio may also exceed 0.1. Furthermore, from the viewpoint of suppressing the reduction in the amount of emitted light, it is preferable that the amount of light with the same wavelength as the resonant wavelength 30w2 from the light L from the light source section 20 is less than 4% of the total amount of light L from the light source section 20.

[0199] Furthermore, in the eighth embodiment and the sixth variation, the example lens 30 in which the second longest resonant wavelength 30w2 is included in the wavelength region of the light L from the light source 20 was described. However, the longest resonant wavelength 30w1 may also be included in the wavelength region of the light L from the light source 20, and all resonant wavelengths may not be included in the wavelength region of the light L from the light source 20.

[0200] Furthermore, in the eighth embodiment and the sixth variation, an example lens 30 was described where all of the multiple resonant wavelengths are different from the wavelengths of each of the multiple peaks. However, it is acceptable as long as the multiple resonant wavelengths are different from the wavelengths of each of the multiple peaks; for example, a specific resonant wavelength may be the same as the wavelength of a certain peak. It should be noted that, from the viewpoint of emitting light of the desired hue, it is preferable that all of the multiple resonant wavelengths are different from the wavelengths of each of the multiple peaks.

[0201] Furthermore, from the viewpoint of emitting light of the desired hue, it is preferable that the transmittance distribution of the light from the element lens 30, with a relative transmittance of 80% or less based on the maximum transmittance of the light L transmitted through the element lens 30 from the light source 20, includes multiple consecutive resonant wavelength regions containing a single resonant wavelength, at least one of which differs from the respective wavelength of each of the multiple peaks. In this case, it is more preferable that all of these resonant wavelength regions differ from the respective wavelengths of each of the multiple peaks. It should be noted that, more preferably, when the transmittance distribution of the light from the element lens 30, with a relative transmittance of 60% or less based on the maximum transmittance of the light L transmitted through the element lens 30 from the light source 20, includes multiple consecutive resonant wavelength regions containing a single resonant wavelength, at least one of these resonant wavelength regions differs from the respective wavelength of each of the multiple peaks. In this case, it is more preferable that all of these resonant wavelength regions differ from the respective wavelengths of each of the multiple peaks. Furthermore, more preferably, when the transmittance distribution of the light from the element lens 30 is 40% or less based on the maximum transmittance of the light L transmitted through the element lens 30 from the light source section 20, and includes multiple consecutive resonant wavelength regions containing a resonant wavelength, at least one of these resonant wavelength regions differs from the respective wavelengths of the multiple peaks. In this case, it is more preferable that all of these resonant wavelength regions differ from the respective wavelengths of the multiple peaks.

[0202] Hereinafter, the present invention will be described with reference to the above-described embodiments and variations, but the present invention is not limited thereto.

[0203] For example, in the above embodiment, the vehicle lamp 1 is a headlight, but the present invention is not particularly limited. For example, the vehicle lamp 1 may also be a lamp that illuminates an object such as a road surface with light constituting an image. In addition, when the vehicle lamp is configured to illuminate an object such as a road surface with light constituting an image, the direction of the light emitted by the vehicle lamp and the position of the vehicle lamp mounted on the vehicle are not particularly limited. Furthermore, the color of the light emitted by the vehicle lamp is not limited to white.

[0204] Furthermore, in the above embodiment, the example described is the element lens 30, which reduces the divergence angle of the light L from the light source unit 20. However, the element lens 30 may also be configured to increase the divergence angle of the light L from the light source unit 20.

[0205] Furthermore, in the above embodiment, the example described is a primary lens 30 whose primary surfaces 31s and 32s, which are planar, are used as the primary regions. However, the primary surfaces 31s and 32s, which are the primary regions, can also be curved. However, from the viewpoint of making the primary lens 30 thinner, the primary surfaces 31s and 32s, which are the primary regions, are preferably planar.

[0206] Furthermore, in the first to fourth embodiments described above, a specific phase distribution 60 having three or more peaks 61 was used as an example. However, the number of peaks 61 is not particularly limited; for example, the specific phase distribution 60 may not have any peaks 61.

[0207] According to the present invention, a miniaturizable vehicle lamp is provided, which can be used in the fields of vehicle lamps such as automobiles.

Claims

1. A vehicle lamp, characterized in that, have: Light source section; A meta-lens, which is arranged with multiple units comprising nanostructures smaller than the longest wavelength of light emitted from the light source and has a meta-region through which the light emitted from the light source can pass. The meta-region causes a change in the phase distribution of the light transmitted through it. When a reference light parallel to a reference axis orthogonal to the elemental region is incident on the elemental region at a specific location within the elemental region, the phase distribution of the reference light emitted from the elemental lens is changed in such a way that the phase distribution of the reference light becomes a specific phase distribution consisting of the remainder after dividing a predetermined phase distribution by 2π. The specified phase distribution is a phase distribution in which the amount of phase delay (rad) decreases with distance from the reference axis, and the rate of decrease of this phase delay increases. The specific phase distribution has multiple peaks. When viewed along the reference axis, multiple units are arranged such that there are two or more units between the peaks that are adjacent to each other in a direction away from the specific location.

2. The vehicle lighting fixture as described in claim 1, characterized in that, The specific phase distribution has more than three of the aforementioned peaks. The number of units located between the peaks decreases as the distance from the specific location increases.

3. The vehicle lighting fixture as described in claim 1 or 2, characterized in that, The nanostructure is cylindrical in shape. The number of units located between the peaks is three or more.

4. The vehicle lighting fixture as described in claim 1, characterized in that, In the element region, the curvature of the element region that bends the infrared light contained in the light transmitted through the element region is smaller than the curvature of the element region that bends the visible light contained in the light transmitted through the element region.

5. The vehicle lighting fixture as described in claim 4, characterized in that, The meta-region is configured such that, in the visible light and the infrared light with a wavelength ratio of 1:1.5, the phase modulation amount of the infrared light is 0.6 times smaller than the phase modulation amount of the visible light.

6. The vehicle lighting fixture as described in claim 4 or 5, characterized in that, The longest wavelength of the visible light is 660 nm. The shortest wavelength of the infrared light is 1000 nm.

7. The vehicle lighting fixture as described in claim 4 or 5, characterized in that, The nanostructure is cylindrical in shape.

8. The vehicle lighting fixture as described in claim 1, characterized in that, At least one of the element lenses has a resonant wavelength greater than 800 nm and less than 2400 nm.

9. The vehicle lighting fixture as described in claim 8, characterized in that, The at least one resonant wavelength is contained in the range of 800 nm or more and less than 900 nm.

10. The vehicle lamp as described in claim 8 or 9, characterized in that, The spectral distribution of the light emitted from the light source has multiple peaks. The resonant wavelengths are different from the wavelengths of the peaks of the spectral distribution of the light.

11. The vehicle lamp as described in claim 10, characterized in that, All of the resonant wavelengths are not included in the wavelength region of the light emitted from the light source.

12. The vehicle lamp as described in claim 8 or 9, characterized in that, The element lens reduces the divergence angle of the light from the light source that passes through it.

13. The vehicle lighting fixture as described in claim 1, characterized in that, The spectral distribution of the light emitted from the light source has multiple peaks. The multiple resonant wavelengths in the element lens are different from the wavelengths of the multiple peaks in the spectral distribution of the light.

14. The vehicle lighting fixture as described in claim 13, characterized in that, At least one of the plurality of resonant wavelengths exceeds the shortest wavelength of the respective peaks of the plurality of light dispersions and is less than the longest wavelength.

15. The vehicle lighting fixture as described in claim 14, characterized in that, The wavelength of the light with the lowest intensity among the peaks of the spectral distribution of the adjacent light is the same as at least one of the plurality of resonant wavelengths.

16. The vehicle lamp as described in claim 13 or 14, characterized in that, The plurality of resonant wavelengths includes specific resonant wavelengths contained within the wavelength region of the light from the light source. The ratio of the intensity of the light at the specific resonant wavelength in the light to the maximum intensity in the overall spectral distribution of the light is less than 0.

1.

17. The vehicle lighting fixture as claimed in claim 1, characterized in that, The incident surface of the element lens, which receives the light from the light source, is convexly curved outwards to refract the light in a manner that reduces the divergence angle. The light incident on the incident surface passes through the meta-region.

18. The vehicle lighting fixture as claimed in claim 1, characterized in that, The incident surface of the element lens, through which light from the light source is incident, is provided with multiple slots to diffract the light in a manner that reduces the divergence angle. The light incident on the incident surface passes through the meta-region.

19. The vehicle lamp as claimed in claim 1, characterized in that, It also has a protective component that is light-transmitting and covers the element area.

20. The vehicle lamp as described in claim 19, characterized in that, The protective component has a lower refractive index than the element lens and is filled between the various nanostructures.

21. The vehicle lighting fixture as claimed in claim 1, characterized in that, The minimum width of the meta-region is 10mm or more.

22. The vehicle lighting fixture as described in claim 1, characterized in that, The meta-region alters the phase distribution of the light transmitted through it in a manner that produces coma aberration, thereby expanding the divergence angle of the light transmitted through it in the left-right direction of the light distribution pattern formed by the light, compared to the case where no coma aberration is produced.

23. The vehicle lighting fixture as described in claim 22, characterized in that, The meta-region ensures that the expansion of the divergence angle to the left due to the coma is the same as the expansion of the divergence angle to the right due to the coma.

24. The vehicle lighting fixture as described in claim 22, characterized in that, The meta-region causes one of the expansions of the divergence angle to the left due to the coma and the expansions of the divergence angle to the right due to the coma to be greater than the other.

25. The vehicle lighting fixture as described in claim 22, characterized in that, Compared to the case where no coma is produced, the meta-region causes the divergence angle of the light transmitted through the meta-region to be extended in the vertical direction of the light distribution pattern formed by the light.

26. The vehicle lighting fixture as described in claim 25, characterized in that, The meta-region causes the expansion of the divergence angle in the left-right direction due to the coma to be greater than the expansion of the divergence angle in the up-down direction due to the coma.

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