JP7266425B2 - Mobile lighting - Google Patents

Description

The present invention relates to a lighting for mobile bodies.

2. Description of the Related Art In recent years, adaptive driving beams (ADBs) have been used as headlights of automobiles, which are capable of controlling the pattern of light distribution according to the conditions of oncoming vehicles, preceding vehicles, and the like. In particular, a variable light distribution lamp using a liquid crystal element capable of rapidly transmitting or blocking a luminous flux is known.

For example, the light emitted from the light source is separated into two polarized partial optical paths, a first liquid crystal mask, a first polarizing filter and a first lens are arranged on the first partial optical path, and a second liquid crystal mask is arranged on the second partial optical path. An automobile headlamp is disclosed in which two liquid crystal masks, a second polarizing filter, and a second lens are arranged, and the first lens and the second lens have different focal lengths (Patent Document 1).

JP 2017-212210 A

By the way, in the case of mobile body lighting that controls the luminous flux by arranging a liquid crystal element on the optical path, there is a problem that a high contrast between the illuminated part and the non-illuminated part cannot be obtained due to the influence of stray light inside the device. .

SUMMARY OF THE INVENTION An object of the present invention is to improve the glare of oncoming vehicles, the visibility of own vehicle, etc. by improving the contrast in a lighting for a mobile object.

One aspect of the present invention is a mobile lighting that separates incident light into two polarizations and utilizes both of the polarizations, wherein at least one absorptive wire grid polarizer having an absorptive layer is disposed. It is a lighting for a moving object, characterized in that

Here, a beam splitter for separating the incident light into the polarized light, a liquid crystal element arranged on the optical path of the polarized light, a first wire grid polarizer arranged on the incident surface side of the liquid crystal element, and the liquid crystal and a second wire grid polarizer arranged on the output surface side of the device, wherein at least one of the first wire grid polarizer and the second wire grid polarizer is the absorption wire grid polarizer. preferred.

Moreover, it is preferable that the absorption layer is disposed on the surface of the absorption wire grid polarizer facing the liquid crystal element.

Further, the beam splitter includes a third wire grid polarizer, and the third wire grid polarizer is the absorptive wire grid polarizer, and the absorption layer is arranged on the light exit surface side. is preferred.

Further, it is preferable that the absorbing wire grid polarizer includes a wire grid made of metal, and the absorbing layer is formed on the upper surface or the lower surface of the wire grid so as to match the shape of the wire grid.

Also, the absorption layer is preferably a dye-based polarizing layer obtained by stretching a polyvinyl alcohol film dyed with a dichroic dye.

Moreover, it is preferable that the absorption layer is formed on the upper surface of the wire grid, and the extending direction of the wire grid and the transmission axis of polarized light are parallel.

Further, it is preferable that the liquid crystal element is driven by a driving element made of a low-temperature polysilicon layer.

Further, it is preferable that a half-wave plate is arranged on the optical path of either one of the polarized light.

Further, it is preferable that the half-wave plate is arranged on the incident surface side of the first wire grid polarizer.

The liquid crystal element preferably comprises a first liquid crystal element arranged on one optical path of the polarized light and a second liquid crystal element arranged on the other optical path of the polarized light.

Further, the absorptive wire grid polarizer may include a grid-like structure transparent to the incident light, and fine particles embedded in gaps between the structures and opaque to the incident light. preferred.

The absorption wire grid polarizer preferably contains a non-conductive material having a product kd of 200 μm or more of an extinction coefficient k and a layer thickness d, where k is an extinction coefficient k and a layer thickness d.

Further, it is preferable that the liquid crystal element is a reflective liquid crystal element.

Further, it is preferable to provide a lens on the optical path of the light transmitted through the wire grid polarizer, which is capable of irradiating optimally for confirming traffic obstacles at a distance of 40 m in front of the wire grid polarizer at night.

According to the present invention, a high contrast can be obtained in a mobile lighting device that controls a luminous flux by arranging a liquid crystal element on an optical path.

It is a figure which shows the structure of the lighting for mobile bodies in embodiment of this invention. It is a figure which shows the structure of the polarizer in embodiment of this invention. It is a figure which shows the structure of the polarizer in embodiment of this invention. It is a figure which shows the structure of the polarizer in embodiment of this invention. FIG. 10 is a diagram showing a configuration of a vehicle lighting according to Modification 1; FIG. 11 is a diagram showing a configuration of a vehicle lighting according to Modification 2; FIG. 10 is a diagram showing a configuration of a mobile body lamp according to Modified Example 3; FIG. 11 is a diagram showing a configuration of a vehicle lighting according to Modification 4; FIG. 11 is a diagram showing a configuration of a vehicle lighting according to Modified Example 5;

As shown in FIG. 1, the mobile body lighting 100 according to the embodiment of the present invention includes a light source 10, a beam splitter 12, a reflecting mirror 14, a first polarizer 16 (16a, 16b), a liquid crystal element 18, a second It comprises a polarizer 20 (20a, 20b) and a lens 22 (22a, 22b).

The mobile body lamp 100 is mounted on a mobile body such as an automobile, and is used as a headlamp or the like for illuminating the moving direction of the mobile body. In particular, it functions as an adjustable light distribution (ADB) that can control the pattern of light distribution according to the situation of an oncoming vehicle, a vehicle in front, etc., using a camera attached to the vehicle or other sensing. As a result, it is possible to shield the oncoming vehicle from being irradiated and to prevent glare, while providing a good field of view for the road and passersby.

The light source 10 is a member that outputs light emitted from the vehicle lighting lamp 100 . The light source 10 can be, for example, a light emitting diode (LED), a laser diode (LD), a halogen lamp, a high pressure mercury lamp (HID), or the like. When LEDs or LDs are used as the light source 10, it is preferable to arrange a large number of individual LED elements in a two-dimensional matrix. The light source 10 outputs a substantially collimated, non-diffused beam of unpolarized light.

The beam splitter 12 is an optical element that splits the light flux from the light source 10 into two. That is, part of the light incident on the beam splitter 12 is reflected, and the remaining part is transmitted. In this embodiment, the beam splitter 12 is a polarizing beam splitter capable of separating light incident from the light source 10 into mutually orthogonal polarized components. Beam splitter 12 may be configured to include a wire grid polarizer.

In the example of FIG. 1 , the beam splitter 12 is arranged at an angle of 45° with respect to the optical path of the light emitted from the light source 10 . The beam splitter 12 splits the light incident from the light source 10 into polarized components perpendicular to the plane of the paper (indicated by dots in the drawing), reflects them at an angle of 45°, and emits them to the first optical path S1. The incident light is separated into polarized light components (indicated by line marks in the figure) parallel to the plane of the drawing, and transmitted through the second optical path S2 along the incident direction of the light. However, the configuration is not limited to such a configuration, and the beam splitter 12 may be configured to separate the polarized components of the light incident from the light source 10 into different directions.

The reflecting mirror 14 is a mirror that reflects light to change the optical path direction. The reflecting mirror 14 is arranged to reflect the light incident along the second optical path S2 at 45 degrees. As a result, the first optical path S1 and the second optical path S2 become substantially parallel optical paths. The reflecting mirror 14 can be configured by vapor-depositing silver (Ag) on a substrate such as glass.

The first polarizer 16 is an optical element that transmits only light polarized in one specific direction and blocks light polarized in other directions with respect to incident light. In the mobile body lighting 100 of FIG. 1, the first polarizer 16a is arranged on the first optical path S1, and the first polarizer 16b is arranged on the second optical path S2. The first polarizer 16a is arranged such that its transmission axis is aligned in the same direction as the polarized light split by the beam splitter 12 along the first optical path S1. That is, the transmission axis of the first polarizer 16a is arranged so as to transmit the light of the polarized light component in the direction perpendicular to the plane of the paper and block the polarized light component of other directions. The first polarizer 16b is arranged such that its transmission axis is aligned in the same direction as the polarized light split by the beam splitter 12 along the second optical path S2. That is, the transmission axis of the first polarizer 16b is arranged so as to transmit the light of the polarized component in the direction parallel to the plane of the paper and block the polarized component of the other direction.

By providing the first polarizer 16 (16a, 16b) on the incident surface side of the liquid crystal element 18 in this way, compared to the configuration in which the polarizer is not provided on the incident surface side of the liquid crystal element as in the prior art, The contrast of the light emitted from the mobile body lighting 100 can be improved.

The liquid crystal element 18 is an optical element having a liquid crystal layer that can be switched between a state of transmitting incident light and a state of blocking incident light. Although the liquid crystal element 18 is not particularly limited, it can be of a drive type such as a TN system, a VA system, or an IPS system. Further, the liquid crystal element 18 preferably constitutes a liquid crystal drive element with a low-temperature polysilicon layer. The liquid crystal element 18 has a configuration in which a large number of liquid crystal cells (pixels) are arranged in a two-dimensional matrix, and each liquid crystal cell (pixel) can transition between a state of transmitting light and a state of blocking incident light. It is preferable that The liquid crystal element 18 is arranged across the first optical path S1 and the second optical path S2. Therefore, the liquid crystal element 18 can control the transmittance of the light in the first optical path S1 and the transmittance of the light in the second optical path S2 to emit light of any shape and intensity.

The second polarizer 20 is an optical element that transmits only light polarized in one specific direction and blocks light polarized in other directions with respect to incident light. In the mobile body lighting 100 of FIG. 1, the second polarizer 20a is arranged on the first optical path S1, and the second polarizer 20b is arranged on the second optical path S2. The second polarizer 20a is arranged such that the transmission axis of the second polarizer 20a is aligned in the same direction as the polarized light transmitted by the liquid crystal element 18 along the first optical path S1. That is, the second polarizer 20a transmits the light on the first optical path S1 that has been converted by the liquid crystal element 18 from the polarized light component in the direction perpendicular to the paper surface to the polarized light component in the direction parallel to the paper surface, and transmits the light polarized in the other direction. A transmission axis is positioned to block the component. The second polarizer 20b is arranged so that the transmission axis is aligned in the same direction as the polarized light transmitted by the liquid crystal element 18 along the second optical path S2. That is, the second polarizer 20b transmits the light on the second optical path S2 that has been converted by the liquid crystal element 18 from the polarization component in the direction parallel to the paper to the polarization component in the direction perpendicular to the paper, and transmits the light polarized in the other direction. A transmission axis is positioned to block the component.

The lens 22 is an optical element that converges transmitted light at a focal length. 1, the lens 22a is arranged on the first optical path S1, and the lens 22b is arranged on the second optical path S2. For example, the focal length f1 of the lens 22a on the first optical path S1 and the focal length f2 of the lens 22b on the second optical path S2 may be different. Thereby, the light incident on the lens 22a along the first optical path S1 is irradiated so as to converge at the focal length f1, and the light incident on the lens 22b along the second optical path S2 converges at the focal length f2. Can be irradiated. That is, it is possible to intensively irradiate different positions with the vehicle lighting 100 .

By controlling the light source 10 and the liquid crystal element 18 in the mobile body lighting 100, the irradiation position, irradiation range, and irradiation intensity of the light can be appropriately changed. For example, when the mobile body lighting 100 is mounted as a headlight of an automobile, a variable light distribution light that can control the light distribution pattern according to the situation of oncoming vehicles, vehicles in front, pedestrians, etc. (ADB).

Here, the first polarizer 16 is preferably an absorbing wire grid polarizer having an absorbing layer. Also, the second polarizer 20 is preferably an absorbing wire grid polarizer having an absorbing layer.

A wire grid polarizer (WGP), as shown in FIG. 2, has a configuration including an array of grids 32 arranged parallel to the surface of a transparent substrate 30 such as glass or resin. That is, it comprises a single periodic array of wire-like grids 32 on substrate 30 . When the period of the wire grid 32 is greater than approximately half the wavelength of light, the wire grid polarizer behaves as a diffraction grating. When the period of the wire grid 32 is less than approximately half the wavelength of light, the wire grid polarizer behaves as a polarizer.

The substrate 30 is a member that structurally supports the structure 34 and the grid 32 . The substrate 30 is made of a material that is translucent to the wavelength region of light to be polarized. When the light to be polarized is visible light, the substrate 30 can be, for example, a glass substrate. Also, the substrate 30 may be made of, for example, polymethyl methacrylate (PMMA), polycarbonate (PC), cycloolefin (COP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), triacetate cellulose (TAC), or the like. It is preferable that the substrate 30 has no or small retardation in the planar direction.

The structure 34 is a member for providing a repeated concave-convex structure on the surface of the substrate 30 . That is, the structure 34 has a configuration in which linear structures extending along the Y direction are periodically and repeatedly arranged along the X direction. The structure 34 is made of a material that is translucent to the wavelength of light to be polarized. Specifically, the structure 34 preferably has a transmittance of 85% or more for the wavelength of light to be polarized. When the light to be polarized is visible light, the structure 34 is preferably made of a resin such as an epoxy resin, a polyimide resin, an acrylic resin, or a polycarbonate resin that has translucency in the wavelength region of visible light. be. Structure 34 is preferably a UV curable resin selected, for example, from the NIAC series manufactured by Daicel. Also, the structure 34 may have a multi-layer structure in which a plurality of different types of resin are laminated. By making the structure 34 into a multi-layer structure, the structure 34 having the characteristics of each resin layer can be constructed.

The grid 32 is a member for polarizing light by reflecting or absorbing the light. The grid 32 has a linear structure repeatedly arranged on the surface of the substrate 30 . That is, the grid 32 has a configuration in which linear structures extending along the Y direction are periodically and repeatedly arranged along the X direction.

The grid 32 is provided so as to be embedded in the concave portion of the structure 34 having the repeated concave-convex structure. However, a configuration in which only the grid 32 is provided without providing the structure 34 may be employed.

In this embodiment, the grid 32 has a configuration in which a reflective polarizer 32a and an absorption layer 32b are superimposed, as shown in the cross-sectional view of FIG. The reflective polarizer 32a is made of a material that is opaque to the wavelength of light to be polarized. When the light to be polarized is visible light, the reflective polarizer 32a is made of, for example, metals such as silver, copper, gold, aluminum, zinc, tungsten, nickel, and platinum, and metals such as tin oxide, indium oxide, and zinc oxide. It can be composed of an oxide or the like. The reflective polarizer 32a preferably has a height of several tens to several hundred μm, for example. The reflective polarizer 32a transmits light vibrating in the direction orthogonal to the longitudinal direction of the grid 32, and reflects light vibrating in the direction parallel to the longitudinal direction of the grid 32. FIG.

The absorption layer 32b has the property of absorbing at least part of incident light. Absorbing layer 32b can be, for example, silicon, germanium, or amorphous silicon. Although the absorption layer 32b is provided on the reflective polarizer 32a in FIG. 3, the reflective polarizer 32a and the absorption layer 32b may be replaced with each other. Furthermore, a configuration may be adopted in which absorption layers 32b are provided on both sides of the reflective polarizer 32a. Further, in FIG. 3, the absorption layer 32b is provided on the upper surface side of the substrate 30, but the absorption layer 32b may be provided on the lower surface side of the substrate 30. FIG. A configuration in which an absorption layer 32b is provided on the opposite side of the reflective polarizer 32a with the substrate 30 interposed therebetween may be employed.

The grid 32 is formed, for example, by forming a 200 μm thick aluminum layer as a reflective polarizer 32a on a substrate 30 such as TAC, and forming a 20 nm thick amorphous silicon layer as an absorbing layer 32b thereon, using a photolithographic technique. It is possible to form them by processing them into a grid shape using, for example. The grid 32 can also be formed by applying nanoimprint lithography technology (NIL). Specifically, a negative resist pattern is formed on the substrate 30 by nanoimprinting, the resist is removed from unnecessary portions by ashing, an aluminum layer is formed as a reflective polarizer 32a by CVD, and an amorphous silicon layer is used as an absorption layer. 32b is formed continuously. Then, the grid 32 can be formed by removing the resist by applying a method called lift-off. Furthermore, the reflective polarizer 32a can also be formed using a metal self-assembly technique (see Macromolecular Chemistry and Physics, Vol.217, No. 6 (2016)).

Alternatively, for example, the grid 32 may be formed by applying a dispersion liquid in which fine particles of the material forming the grid 32 are dispersed in the gaps between the structures 34 having the repeated concave-convex structure. A spin coating method, for example, can be applied as a method for applying the dispersion liquid. Alternatively, a method of filling the gaps in the structure 34 with the dispersion using capillary action may be applied.

Here, it is preferable that 20% or more of the fine particles have a particle diameter equal to or smaller than the gap of the structure 34 (approximately the width W1 of the grid 32). With such a particle diameter, the concave portions of the structure 34 having the repeated concave-convex structure can be appropriately filled with fine particles. Moreover, the dispersion medium for dispersing the fine particles may be, for example, water, an organic solvent (such as alcohol), or the like. It is preferable that the concentration of the fine particles in the dispersion is 10% or more and 90% or less. The grid 32 can be formed by removing the dispersion medium contained in the dispersion applied in this manner. For example, the dispersion medium can be removed by evaporating the dispersion medium by heating in a state where the dispersion liquid is applied. Note that the application of the dispersion liquid and the removal of the dispersion medium may be repeated as necessary.

At this time, the grid 32 may be formed by laminating a plurality of different materials. For example, fine particles made of a material such as silver (Ag) may be applied to form the reflective polarizer 32a, and fine particles made of a material such as carbon black may be applied to form the absorption layer 32b. In this case, the reflective polarizer 32a is formed by applying and drying a dispersion liquid in which fine particles made of a material such as silver (Ag) are dispersed. Thereafter, a dispersion liquid in which fine particles of a material such as carbon black are dispersed is applied and dried to form the absorption layer 32b.

The periodic structure of the grid 32 is set according to the wavelength of light to be polarized. The pitch P at which the grids 32 are arranged is preferably set to 1/5 to 1/2 times the wavelength of the light to be polarized. For example, when the light to be polarized is visible light, the pitch P of the grid 32 is preferably 400 nm or less, more preferably 150 nm or less. Also, the width W1 of the grid 32 is preferably 200 nm or less, more preferably 30 nm or more and 100 nm or less. Therefore, the pitch P of the structures 34 is also set to 400 nm or less, and the width W2 of the structures 34 is the value obtained by subtracting the width W1 of the grid 32 from the pitch P, and is preferably 50 nm or more and 120 nm or less, for example.

Also, the layer thickness d of the grid 32 is preferably 200 nm or more. Also, the aspect ratio (layer thickness d/width W1) of the grid 32 is preferably 2 or more. When the grid 32 has an extinction coefficient k and a layer thickness d, the product kd of the extinction coefficient k and the layer thickness d is preferably 100 nm or more, more preferably 200 nm or more. be. Here, the extinction coefficient k is the intensity change due to the absorption of light in the substance I=I ₀ exp(-ax) (where the initial intensity I ₀ of the light incident on the substance, the absorption coefficient a, the thickness of the substance x), it is a coefficient represented by the relationship of absorption coefficient a=4πk/λ (where the wavelength of light is λ). When the grid 32 has a multi-layer structure, the extinction coefficient k(n) of each layer and the layer thickness d The sum of the products of (n), Σk(n)·d(n), is preferably 200 nm or more. For example, in the grid 32 having a two-layer structure, when the first grid layer has an extinction coefficient of k1 and a layer thickness of d1, and the second grid layer has an extinction coefficient of k2 and a layer thickness of d2, k1·d1+k2·d2 is It is preferably 200 nm or more. By satisfying the condition of the product kd of the extinction coefficient k and the layer thickness d, excellent polarization characteristics can be obtained in both transmission and reflection even if the pitch P of the grid 32 is 400 nm or less.

Such a wire grid polarizer is commercially available under the product name of Proflux PPL05C or Proflux PFU01C (both manufactured by Polatechno Co., Ltd.).

Also, a planarization layer may be provided on the surfaces of the grid 32 and the structures 34 . The flattening layer is preferably a resin layer having a thickness of about 1 μm. Also, the refractive index of the flattening layer is preferably 1.5 or less, more preferably 1.4 or less.

Alternatively, the absorbing layer 32b may include a polarizing element obtained by stretching a PVA-based resin (for example, a polyvinyl alcohol film) dyed with a dichroic dye. The thickness of the absorption layer 32b is preferably about 5 μm, for example. The absorption layer 32b has an absorption axis in the extending direction, and the absorption axis is arranged so as to be parallel to the extending direction of the grid 32. FIG.

The dichroic dye is preferably composed of a dye-based material. As the dichroic dye, for example, an azo compound, an anthraquinone compound, a tetrazine compound or a salt thereof can be used. Among them, when an azo compound or a salt thereof is used, not only the optical properties are excellent, but also the durability of the optical properties under high-temperature conditions or high-temperature and high-humidity conditions is better than when iodine is used. Because of its superiority, long-term reliability can be obtained in use in harsh environments such as vehicles. In addition, it is possible to obtain a polarizer with optimally adjusted optical waveform and hue for the vehicle lighting 100 by blending various dyes.

The following dyes can be exemplified as azo compound dyes.

（式中、Ｒ_１は水素原子、低級アルキル基、低級アルコキシル基、ヒドロキシル基、スルホン酸基、又はカルボキシル基を示し、Ｒ_２～Ｒ_５は各々独立に、水素原子、低級アルキル基、低級アルコキシル基、又はアセチルアミノ基を示し、Ｘは置換基を有してもよいベンゾイルアミノ基、置換基を有してもよいフェニルアミノ基、置換基を有してもよいフェニルアゾ基、又は置換基を有してもよいナフトトリアゾール基であり、ｍは１又は２、ｎは０又は１を示す。） (1) An azo compound or a salt thereof represented by the chemical formula (1) disclosed in republished patent WO2009/057676 (A1).

(wherein R ₁ represents a hydrogen atom, a lower alkyl group, a lower alkoxyl group, a hydroxyl group, a sulfonic acid group, or a carboxyl group; R ₂ to R ₅ each independently represents a hydrogen atom, a lower alkyl group, a lower alkoxyl or an acetylamino group, and X is a benzoylamino group optionally having a substituent, a phenylamino group optionally having a substituent, a phenylazo group optionally having a substituent, or a substituent It is a naphthotriazole group that may have, m is 1 or 2, n is 0 or 1.)

（式中、Ａは、置換基を有するフェニル基又は１～３のスルホン酸基を有するナフチル基を示し、Ｘは、－Ｎ＝Ｎ－又は－ＮＨＣＯ－を示す。Ｒ_１～Ｒ_４は各々独立に水素原子、低級アルキル基又は低級アルコキシル基を示し、ｍ＝１～３、ｎ＝０又は１を示す。） (2) an azo compound or a salt thereof represented by the chemical formula (2) disclosed in republished patent WO2007/145210 (A1);

(In the formula, A represents a substituted phenyl group or a naphthyl group having 1 to 3 sulfonic acid groups, X represents -N=N- or -NHCO-. R ₁ to R ₄ each independently represents a hydrogen atom, a lower alkyl group or a lower alkoxyl group, and m = 1 to 3 and n = 0 or 1.)

（式中、Ｒ_１はスルホン酸基、カルボキシル基又は低級アルコキシ基を表し、Ｒ_２は、スルホン酸基、カルボキシル基、低級アルキル基又は低級アルコキシ基を表す。但し、Ｒ_１、Ｒ_２がともにスルホン酸基の場合を除く。Ｒ_３～Ｒ_６は各々独立に水素原子、低級アルキル基又は低級アルコキシル基、Ｒ_７、Ｒ_８は各々独立に水素原子、アミノ基、水酸基、スルホン酸基又はカルボキシル基を表す。） (3) A trisazo dye represented by the chemical formula (3) disclosed in republished patent WO2006/057214 (A1).

(wherein R ₁ represents a sulfonic acid group, a carboxyl group or a lower alkoxy group, and R ₂ represents a sulfonic acid group, a carboxyl group, a lower alkyl group or a lower alkoxy group, provided that both R ₁ and R ₂ Except for sulfonic acid groups, each of R ₃ to R ₆ is independently a hydrogen atom, a lower alkyl group or a lower alkoxyl group, and each of R ₇ and R ₈ is independently a hydrogen atom, an amino group, a hydroxyl group, a sulfonic acid group or a carboxyl group. represents a group.)

（式中、Ｍは銅、ニッケル、亜鉛及び鉄から選ばれる遷移金属を表し；Ａ^１は置換されていてもよいフェニル又は置換されていてもよいナフチルを表し；Ｂ^１は置換されていてもよい１－又は２－ナフトール残基を表し、そのナフトールの水酸基はアゾ基の隣接位にあって、Ｍで表される遷移金属と錯結合しており；Ｒ^１及びＲ^２はそれぞれ独立に、水素、低級アルキル、低級アルコキシ、カルボキシル、スルホ、スルファモイル、Ｎ－アルキルスルファモイル、アミノ、アシルアミノ、ニトロ又はハロゲンを表す。） (4) A metal-containing disazo compound represented by the chemical formula (4) disclosed in JP-A-2004-251963 or a salt thereof.

(wherein M represents a transition metal selected from copper, nickel, zinc and iron; A ¹ represents optionally substituted phenyl or optionally substituted naphthyl; B ¹ represents optionally substituted represents a good 1- or 2-naphthol residue, the hydroxyl group of which naphthol is adjacent to the azo group and is complexed with the transition metal represented by M; R ¹ and R ² are each independently represents hydrogen, lower alkyl, lower alkoxy, carboxyl, sulfo, sulfamoyl, N-alkylsulfamoyl, amino, acylamino, nitro or halogen.)

（式中、Ａ^２及びＢ^２はそれぞれ独立に、置換されていてもよいフェニル又は置換されていてもよいナフチルを表し；Ｒ^３及びＲ^４はそれぞれ独立に、水素、低級アルキル、低級アルコキシ、カルボキシル、スルホ、スルファモイル、Ｎ－アルキルスルファモイル、アミノ、アシルアミノ、ニトロ又はハロゲンを表し；ｍは０又は１を表す。） (5) A trisazo compound represented by the chemical formula (5).

(wherein A ² and B ² each independently represent optionally substituted phenyl or optionally substituted naphthyl; R ³ and R ⁴ each independently represent hydrogen, lower alkyl, lower alkoxy, carboxyl, sulfo, sulfamoyl, N-alkylsulfamoyl, amino, acylamino, nitro or halogen; m represents 0 or 1.)

（式中、Ａはメチル基で置換されたフェニル基又はナフチル基を表し、Ｒはアミノ基、メチルアミノ基、エチルアミノ基又はフェニルアミノ基を表す。） (6) A water-soluble compound represented by the chemical formula (6) disclosed in JP-A-3-12606 or a copper complex salt thereof.

(In the formula, A represents a phenyl group or naphthyl group substituted with a methyl group, and R represents an amino group, methylamino group, ethylamino group or phenylamino group.)

(7) A water-soluble disazo compound represented by the chemical formula (7) disclosed in JP-A-59-145255 or a copper complex salt thereof.

(8) Others, such as C.I. I. Direct Yellow 12, C.I. I. Direct Yellow 28, C.I. I. Direct Yellow 44, C.I. I. Direct Yellow 142, C.I. I. Direct Orange 26, C.I. I. Direct Orange 39, C.I. I. Direct Orange 71, C.I. I. Direct Orange 107, C.I. I. Direct Red 2, C.I. I. Direct Red 31, C.I. I. Direct Red 79, C.I. I. Direct Red 81, C.I. I. Direct Red 117, C.I. I. Direct Red 247, C.I. I. Direct Green 80, C.I. I. Direct Green 59, C.I. I. Direct Blue 71, C.I. I. Direct Blue 78, C.I. I. Direct Blue 168, C.I. I. Direct Blue 202, C.I. I. Direct Violet 9, C.I. I. Direct Violet 51, C.I. I. Direct Brown 106, C.I. I. Direct Brown 223 and the like. In addition, it is preferable to dye PVA with two or more of these dyes so as to compensate for the polarization characteristics at each wavelength in the visible region, thereby providing a hue exhibiting a neutral gray. Further, the achromatic polarizing plate series manufactured by Polatechno Co., Ltd., which are dye-based polarizing plates designed so that the transmittance of each wavelength in the visible light region is uniform, may be used.

Examples of commercially available dyes include Kayafect Violet P Liquid (manufactured by Nippon Kayaku Co., Ltd.), Kayafect Yellow Y and Kayafect Orange G, Kayafect Blue KW and Kayafect Blue Liquid 400.

At least one of the first polarizer 16a and the first polarizer 16b and the second polarizer 20a and the second polarizer 20b is preferably an absorptive wire grid polarizer. As a result, stray light generated in the vehicle lighting 100 can be absorbed by the absorption layer 32b included in the absorption wire grid polarizer, and the contrast in illumination by the vehicle lighting 100 can be improved. .

At this time, it is preferable to dispose the absorptive wire grid polarizer so that the absorptive layer 32b faces the liquid crystal element 18. FIG. That is, when an absorptive wire grid polarizer is applied to the first polarizer 16a, the first polarizer 16a is arranged so that the absorption layer 32b faces the incident surface side of the liquid crystal element 18. FIG. Similarly, when an absorptive wire grid polarizer is applied to the first polarizer 16b, the first polarizer 16b is arranged so that the absorption layer 32b faces the incident surface side of the liquid crystal element 18. FIG. Further, when an absorption wire grid polarizer is applied to the second polarizer 20a, the second polarizer 20a is arranged so that the absorption layer 32b faces the exit surface side of the liquid crystal element 18. FIG. Similarly, when an absorptive wire grid polarizer is applied to the second polarizer 20b, the second polarizer 20b is arranged so that the absorptive layer 32b faces the exit surface side of the liquid crystal element 18. FIG.

Also, the contrast in the mobile body lighting 100 can be improved by providing absorption layers on both the entrance surface and the exit surface of the first polarizers 16a and 16b and the second polarizers 20a and 20b.

In the moving body lighting 100, stray light is generated when light enters the liquid crystal element 18 or when light exits from the liquid crystal element 18, and this stray light may reduce the contrast of the irradiated light. Therefore, by arranging the absorptive wire grid polarizer so that the absorption layer 32b faces the liquid crystal element 18, the stray light generated by the liquid crystal element 18 can be effectively absorbed. can improve the contrast of the irradiated light.

The contrast of the mobile object lighting 100 was measured using a spectral radiance meter USR-45 series manufactured by Ushio Electric. It was obtained by measuring the luminance emitted from the lamp 100 .

Also, the beam splitter 12 may be an absorptive wire grid polarizer. As a result, the beam splitter 12 also absorbs the stray light from the vehicle lighting 100, so that the contrast of the light emitted from the vehicle lighting 100 can be improved.

For example, it is preferable to dispose the beam splitter 12 so that the absorption layer 32b is positioned on the light emitting surface side. As a result, stray light generated in the reflecting mirror 14 and the first polarizer 16 and returned to the first polarizer 16 can be effectively absorbed by the absorption layer 32b. As a result, the contrast of the light emitted from the mobile body lighting 100 can be improved.

When a driver of an automobile wears polarized sunglasses, the absorption axis of the sunglasses may coincide with the polarization axis of the light emitted from the vehicle lighting 100 and may not be visible. In the mobile body lighting 100 shown in FIG. 1, the light emitted from the lens 22a and the light emitted from the lens 22b have polarized components orthogonal to each other. Since they do not match, it is possible to ensure the visibility of the driver wearing polarized sunglasses.

[Modification 1]
FIG. 5 shows the configuration of the mobile body lamp 102 in Modification 1 of the above embodiment. In the mobile body lighting 102, the half-wave plate 24 is arranged on one of the optical paths of the polarized light split into the first optical path S1 and the second optical path S2 by the beam splitter 12. FIG.

In the example of FIG. 5, a half-wave plate 24 is arranged on the second optical path S2 between the reflecting mirror 14 and the first polarizer 16 . This makes it possible to align the polarization directions (perpendicular to the plane of the drawing) of the light incident on the first polarizer 16 in the first optical path S1 and the second optical path S2. However, a configuration in which a half-wave plate 24 is arranged in the first optical path S1 between the beam splitter 12 and the first polarizer 16 may be employed. In this case, it is possible to align the polarization directions (directions parallel to the plane of the drawing) of the light incident on the first polarizer 16 in the first optical path S1 and the second optical path S2.

With such a configuration, the polarization component of the first optical path S1 or the second optical path S2 is rotated by 90 degrees before entering the first polarizer 16, and before entering the first polarizer 16, the polarization component of the first optical path is rotated. The polarization components of the light in S1 and the second optical path S2 can be matched. Therefore, the first polarizer 16 and the second polarizer 20 can be combined into one, and the configuration of the mobile body lamp 102 can be simplified.

Further, it is not necessary to control the liquid crystal element 18 in consideration of two orthogonal polarizations, unlike the lighting 100 for a moving body. Therefore, the configuration of the control circuit of the liquid crystal element 18 and the like can be simplified.

Note that when the polarization directions of the light in the first optical path S1 and the second optical path S2 are the same as in the mobile body lighting 102, when a driver of a car wears polarized sunglasses, the absorption axis of the sunglasses does not match. If the polarization axis of the light emitted from the moving body lighting 102 matches, it may become difficult to visually recognize. Therefore, for example, a retardation plate may be provided in either the first optical path S1 or the second optical path S2 to shift the optical axis of the light emitted from the vehicle lighting 102 to solve the problem of visibility. can be done.

At least one of the first polarizer 16 and the second polarizer 20 is preferably an absorptive wire grid polarizer in the mobile body lighting 102 as well. As a result, the stray light generated in the vehicle lighting 102 can be absorbed by the absorption layer 32b included in the absorption wire grid polarizer, and the contrast in the illumination by the vehicle lighting 102 can be improved. .

Also in the mobile body lighting 102, the beam splitter 12 may be an absorption wire grid polarizer. As a result, the beam splitter 12 also absorbs the stray light from the vehicle lighting 102, so that the contrast of the light emitted from the vehicle lighting 102 can be improved.

[Modification 2]
FIG. 6 shows the configuration of the mobile body lamp 104 in Modification 2 of the above-described embodiment. In the moving body lighting 104, similarly to the moving body lighting 102, the polarized light split into the first optical path S1 and the second optical path S2 by the beam splitter 12 has a half-wave plate 24 on either one of the optical paths. is placed.

The mobile body lighting 104 has a configuration in which a half-wave plate 24 is arranged on the second optical path S2 between the beam splitter 12 and the reflecting mirror 14 . This makes it possible to align the polarization directions (perpendicular to the plane of the drawing) of the light incident on the first polarizer 16 in the first optical path S1 and the second optical path S2.

With such a configuration, the polarization component of the second optical path S2 is rotated by 90 degrees before being incident on the first polarizer 16, and the polarization component is rotated by 90 degrees before being incident on the first polarizer 16, as in the first modification. The polarization components of the light on the first optical path S1 and the light on the second optical path S2 can be matched. Therefore, the first polarizer 16 and the second polarizer 20 can be combined into one, and the configuration of the mobile body lamp 104 can be simplified. Further, it is not necessary to control the liquid crystal element 18 in consideration of two orthogonal polarizations, unlike the lighting 100 for a moving body. Therefore, the configuration of the control circuit of the liquid crystal element 18 and the like can be simplified.

Also in the mobile body lighting 104, at least one of the first polarizer 16 and the second polarizer 20 is preferably an absorptive wire grid polarizer. As a result, stray light generated in the vehicle lighting 104 can be absorbed by the absorption layer 32b included in the absorption wire grid polarizer, and the contrast in illumination by the vehicle lighting 104 can be improved. .

Also in the mobile body lighting 104, the beam splitter 12 may be an absorption wire grid polarizer. As a result, the beam splitter 12 also absorbs the stray light from the vehicle lighting 104, so that the contrast of the light emitted from the vehicle lighting 104 can be improved.

[Modification 3]
FIG. 7 shows the configuration of the mobile body lamp 106 in Modification 3 of the above embodiment. In the mobile body lamp 106, two liquid crystal elements 18a and 18b are provided as the liquid crystal elements 18. FIG. That is, the liquid crystal element 18a is arranged on the first optical path S1, and the liquid crystal element 18b is arranged on the second optical path S2.

Here, it is preferable to set the liquid crystal element 18a and the liquid crystal element 18b exclusively to either the O mode or the E mode, respectively. The O-mode liquid crystal element 18 is a mode in which the absorption axis direction of the first polarizer 16 arranged on the incident surface side of the liquid crystal element 18 and the alignment direction of the liquid crystal element 18 are parallel. The E-mode liquid crystal element 18 is a mode in which the absorption axis direction of the first polarizer 16 arranged on the incident surface side of the liquid crystal element 18 and the orientation direction of the liquid crystal element 18 are orthogonal to each other.

With such a configuration, the configuration of the mobile body lamp 106 can be simplified, and the manufacturing cost can be reduced.

Also in the mobile body lighting 106, at least one of the first polarizer 16a and the first polarizer 16b and the second polarizer 20a and the second polarizer 20b is preferably an absorptive wire grid polarizer. . As a result, the stray light generated in the vehicle lighting 106 can be absorbed by the absorption layer 32b included in the absorption wire grid polarizer, and the contrast in the illumination by the vehicle lighting 106 can be improved. .

Also in the mobile body lighting 106, the beam splitter 12 may be an absorption wire grid polarizer. As a result, the beam splitter 12 also absorbs the stray light from the vehicle lighting 106, so that the contrast of the light emitted from the vehicle lighting 106 can be improved.

[Modification 4]
FIG. 8 shows the configuration of the mobile body lamp 108 in Modification 4 of the above embodiment. In the mobile body lamp 108, a beam splitter 12a arranged on the first optical path S1 and a beam splitter 12b arranged on the second optical path S2 are provided as the beam splitter 12. FIG. The beam splitter 12a splits the light incident from the light source 10 into two, a first optical path S1 and a second optical path S2. In the mobile body lighting 108, for example, the beam splitter 12a separates the light incident from the light source 10 into polarized light components perpendicular to the plane of the paper, reflects the polarized light components along the first optical path S1 toward the liquid crystal element 18c, and also splits the polarized light components parallel to the plane of the paper. polarized light component and transmitted through the second optical path S2 toward the beam splitter 12b. The beam splitter 12b reflects the light incident from the beam splitter 12a to the second optical path S2 toward the liquid crystal element 18d.

In the mobile body lamp 108, the liquid crystal element 18 (18c, 18d) is a reflective liquid crystal element that can change the state of incident polarized light by controlling the alignment state of the liquid crystal. The liquid crystal element 18c is arranged on the first optical path S1, and the liquid crystal element 18d is arranged on the second optical path S2. The liquid crystal element 18 (18c, 18d) has a large number of liquid crystal cells (pixels) arranged in a two-dimensional matrix, and by controlling the alignment state of each liquid crystal cell (pixel), the direction of incident polarized light can be maintained or 90°. It can be output as a degree-rotated polarized light. Therefore, the polarization state of the light on the first optical path S1 and the polarization state of the light on the second optical path S2 can be controlled by the liquid crystal element 18 (18c, 18d) to emit polarized light in a free shape and direction.

By controlling the orientation of the liquid crystal element 18 (18c, 18d), the polarized light parallel to the plane of the paper emitted from the liquid crystal element 18c passes through the beam splitter 12a and enters the second polarizer 20a. The second polarizer 20a is arranged such that its transmission axis is aligned in the same direction as the polarization along the first optical path S1. That is, the transmission axis of the second polarizer 20a is arranged so as to transmit the light of the polarized light component in the direction parallel to the plane of the paper and block the polarized light component of the other directions. The second polarizer 20b is arranged so that its transmission axis is aligned in the same direction as the polarization along the second optical path S2. That is, the transmission axis of the second polarizer 20b is arranged so as to transmit the light of the polarized light component in the direction perpendicular to the plane of the paper and block the polarized light component of other directions. The lenses 22 (22a, 22b) are arranged in the same manner as the mobile body lighting 100. FIG.

In this manner, the vehicle lighting 108 using the reflective liquid crystal element 18 can be configured. By making the liquid crystal element 18 of a reflective type, it is possible to suppress heat generation inside the vehicle lighting 108 and improve the efficiency of the entire device.

In the moving object lighting 108, the liquid crystal element 18 itself is of a reflective type. However, the liquid crystal element 18 may be of a transmissive type, and a reflecting mirror or the like may be provided on the rear surface of the liquid crystal element 18 to function as a reflective optical element as a whole. good.

Also in the mobile body lighting 108, at least one of the second polarizers 20a and 20b is preferably an absorptive wire grid polarizer. As a result, the stray light generated in the vehicle lighting 108 can be absorbed by the absorption layer 32b included in the absorption wire grid polarizer, and the contrast in illumination by the vehicle lighting 108 can be improved. .

Also in the mobile body lighting 108, at least one of the beam splitter 12a and the beam splitter 12b may be an absorptive wire grid polarizer. As a result, the beam splitter 12a and the beam splitter 12b also absorb the stray light from the vehicle lighting 108, so that the contrast of the light emitted from the vehicle lighting 108 can be improved.

[Modification 5]
FIG. 9 shows a configuration of a vehicle lighting 110 according to Modification 5 of the above embodiment. In the mobile body lighting 110, the second optical path S2 passing through the beam splitter 12 is provided with the reflecting mirror 14 and the lens 22b in this order.

In the moving body lighting 110, the liquid crystal element 18c is a reflective liquid crystal element that can change the state of incident polarized light by controlling the orientation of the liquid crystal layer, as in the moving body lighting 108. FIG. As a result, the light on the optical path S1 can be illuminating light having a high contrast, and a highly safe ADB system can be realized.

Also in the mobile body lighting 110, the beam splitter 12 is preferably an absorbing wire grid polarizer. As a result, stray light generated in the moving body lighting 110 can be absorbed by the absorption layer, and the contrast in the optical path S1 can be improved.

Also, by not providing a polarizing element and a liquid crystal element in the optical path S2, the light passing through the beam splitter 12 can be used without loss. Also, the lens 22b provided on the output side of the optical path S2 is preferably suitable for recognizing an obstacle at a distance of 40 m ahead at night. As a result, the glare of oncoming vehicles can be reduced and the visibility can be improved with respect to the light irradiation from the mobile body lamp 110 .

10 light source 12 (12a, 12b) beam splitter 14 reflector 16 (16a, 16b) first polarizer 18 (18a, 18b, 18c, 18d) liquid crystal element 20 (20a, 20b) second polarizer , 22 (22a, 22b) lens, 24 half-wave plate, 30 substrate, 32 grid, 32a reflective polarizer, 32b absorption layer, 34 structure, 100, 102, 104, 106, 108, 110 moving body illumination light.

Claims (14)

A lighting for a moving object that splits incident light into two polarized light and utilizes both of the polarized lights,
At least one absorptive wire grid polarizer having an absorptive layer is disposed ;
a beam splitter for separating the incident light into the polarized light;
a liquid crystal element arranged on the optical path of the polarized light;
a first wire grid polarizer arranged on the incident surface side of the liquid crystal element; a second wire grid polarizer arranged on the exit surface side of the liquid crystal element;
with
A lighting for a vehicle , wherein the first wire grid polarizer is an absorption wire grid polarizer having an absorption layer . The mobile lighting device according to claim 1 ,
A lighting for a moving object, wherein the absorbing wire grid polarizer has the absorbing layer disposed on a surface facing the liquid crystal element. 3. The mobile body lighting according to claim 1 ,
the beam splitter includes a third wire grid polarizer;
A lighting for a moving object, wherein the third wire grid polarizer is the absorption type wire grid polarizer, and the absorption layer is arranged on a light emitting surface side. A lighting for a mobile object according to any one of claims 1 to 3 ,
The absorbing wire grid polarizer comprises a wire grid made of metal,
A lighting for a moving body, wherein the absorption layer is formed on an upper surface or a lower surface of the wire grid so as to match the shape of the wire grid. The mobile lighting device according to claim 4 ,
A lamp for a moving body, wherein the absorption layer is a dye-based polarizing layer obtained by stretching a polyvinyl alcohol film dyed with a dichroic dye. A lighting for a mobile object according to claim 5 ,
A lighting for a moving object, wherein the absorption layer is formed on the upper surface of the wire grid, and the extending direction of the wire grid and the transmission axis of polarized light are parallel to each other. The mobile lighting device according to claim 1 ,
A lamp for a moving body, wherein the liquid crystal element is driven by a driving element made of a low-temperature polysilicon layer. The mobile lighting device according to claim 1 ,
A lighting for a moving body, wherein a half-wave plate is arranged on an optical path of either one of the polarized lights. The mobile lighting device according to claim 8 ,
A lighting for a moving body, wherein the half-wave plate is arranged on the incident surface side of the first wire grid polarizer. The mobile lighting device according to claim 1 ,
wherein the liquid crystal element comprises a first liquid crystal element arranged on one optical path of the polarized light and a second liquid crystal element arranged on the other optical path of the polarized light; light. A lighting for a mobile object according to any one of claims 1 to 10 ,
The absorptive wire grid polarizer comprises a grid-like structure transparent to the incident light, and fine particles embedded in gaps between the structures and opaque to the incident light. mobile lighting. A lighting for a mobile object according to any one of claims 1 to 11 ,
The absorptive wire grid polarizer includes a non-conductive material in which the product kd of the extinction coefficient k and the layer thickness d is 200 nm or more when the extinction coefficient k and the layer thickness d are assumed to be 200 nm or more. body light. The mobile lighting device according to claim 1 ,
A lamp for a moving body, wherein the liquid crystal element is a reflective liquid crystal element. The mobile lighting device according to claim 1,
For a moving object, comprising a lens on the optical path of the light transmitted through the wire grid polarizer, capable of irradiating optimally for confirming traffic obstacles at a distance of 40 m in front of the wire grid polarizer at night. lighting.

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