JP5263606B2 - Liquid crystal element and vehicle lamp - Google Patents

Description

  The present invention relates to a vehicular lamp, and more particularly to a vehicular lamp capable of forming a more appropriate low beam light distribution pattern, a more appropriate high beam light distribution pattern, and a liquid crystal element used in the vehicular lamp.

  Conventionally, a headlamp that uses a movable shade to switch between a low beam and a high beam is known (see, for example, Patent Document 1).

  FIG. 25 is a diagram for explaining the vehicular lamp 200 described in Patent Document 1. In FIG.

  As shown in FIG. 25, the vehicular lamp 200 described in Patent Document 1 blocks a projection lens 210, a light source 220, a reflector 230 that reflects irradiation light from the light source 220, and a part of the reflected light from the reflector 230. The movable shade 240 is connected to the movable shade 240 and includes an actuator 250 that moves the movable shade 240.

  In the vehicular lamp 200 described in Patent Document 1, the shade 240 is rotated around the rotation shaft 241 by the driving force from the actuator 250 and is positioned at either the light shielding position P1 or the open position P2. Thereby, it can switch to either a low beam or a high beam.

JP 2006-341696 A

  However, in the vehicular lamp 200 described in Patent Document 1, the irradiation light from the same optical system is always used regardless of whether the beam is a low beam or a high beam. There is a problem that it is difficult to form a light distribution pattern and a more appropriate high beam light distribution pattern.

  The present invention has been made in view of such circumstances, and a vehicle lamp that can form a more appropriate low-beam light distribution pattern, a more appropriate high-beam light distribution pattern, and the vehicle lamp. It aims at providing the liquid crystal element used.

In order to solve the above-mentioned problem, the invention according to claim 1 includes two glass substrates on which a transparent electrode and a horizontal alignment film that has been rubbed so that the rubbing directions are in an antiparallel relationship with each other, and A rod-like liquid crystal molecule having a positive dielectric anisotropy in which a rod-like liquid crystalline UV curable monomer and a photopolymerization initiator are added between two glass substrates, and the liquid crystal layer thickness is 15 μm Injecting liquid crystal molecules in which the liquid crystal molecules are aligned along the rubbing direction, the liquid crystal layer formed between the two glass substrates, the liquid crystal molecules and the ultraviolet curable monomer Formed in the liquid crystal layer by irradiating the liquid crystal layer in a vertically aligned state with ultraviolet rays and curing the ultraviolet curable monomer to an extent that does not restrain the liquid crystal molecules. The polymer network is arranged so that the liquid crystal molecules of the liquid crystal layer are vertically aligned when a voltage is applied between the transparent electrodes, and no voltage is applied between the transparent electrodes. The liquid crystal layer is in a state where the rod-like liquid crystal molecules contained in the liquid crystal layer are in a horizontal alignment state, the refractive index in the rubbing direction is n _e1 , and perpendicular to the rubbing direction. direction refractive index n _o1 to _{(where, n e1>} n _O1), and the state of the liquid crystal molecules are vertically aligned contained in the liquid crystal layer, the refractive index of the rubbing direction is n _o1, perpendicular to the rubbing direction direction refractive index _{n o1} next and a liquid crystal layer which does not contain a chiral agent, wherein the polymer network, the refractive index of the rubbing direction _{n o2 (where, n O2} ≒ _{n O1} , The refractive index in the direction perpendicular to the rubbing direction is a polymer network comprising a n _o2, cause transmission at the perpendicular orientation relative to the transmitted light, and wherein the resulting anisotropic scattering when the horizontal alignment.

According to the first aspect of the present invention, since the liquid crystal molecules are not constrained by the polymer network, when a voltage is applied between the transparent electrodes, the liquid crystal molecules in the liquid crystal layer are aligned vertically (with respect to the glass substrate). , Vertical posture). Since liquid crystal molecules are molecules of the rod-shaped, in the case where the liquid crystal molecules becomes vertical alignment liquid crystal layer, in a plan view, the refractive index of the rubbing directions n _o1, the refractive index in the direction perpendicular to the rubbing direction n _o1 . On the other hand, the polymer network is, for example, a rod-like, liquid-crystalline UV-curable monomer formed by UV-curing in a vertically aligned state, so that it is rubbed in a plan view regardless of whether a voltage is applied or not. direction refractive index n _o2, the refractive index in the direction perpendicular to the rubbing direction becomes n _o2.

In this case, focusing on the direction perpendicular to the rubbing direction, the refractive index _{no1 in the} direction perpendicular to the rubbing direction of the liquid crystal layer is related to the refractive index _{no2 in the} direction perpendicular to the rubbing direction of the polymer network in the optical characteristics. Will have an impact. On the other hand, when focusing on the rubbing direction, the relationship between the refractive index _no1 of the rubbing direction of the liquid crystal layer and the refractive index _no2 of the rubbing direction of the polymer network N affects the optical characteristics.

Here, by selecting an appropriate material so that the n _{o1 of} the liquid crystal molecules constituting the liquid crystal layer and the n _o2 of the UV-curable liquid crystal monomer that is the starting material of the polymer network are substantially equal, the liquid crystal molecules and the polymer network are selected. There is substantially no difference in refractive index at the interface.

  For this reason, the irradiation light from the light source that has reached the liquid crystal element in a state where a voltage is applied (liquid crystal molecules are vertically aligned) is hardly refracted (scattered) at the interface between the liquid crystal molecules (liquid crystal layer) and the polymer network ( That is, the light passes through the liquid crystal element (liquid crystal layer) with little scattering in the rubbing direction and the direction orthogonal to the rubbing direction.

On the other hand, when no voltage is applied between the transparent electrodes, the liquid crystal molecules are not constrained by the polymer network, so the liquid crystal molecules in the liquid crystal layer are aligned horizontally (horizontally with respect to the glass substrate and along the rubbing direction. Lined up). Since liquid crystal molecules are molecules of the rod-shaped, in the case where the liquid crystal molecules in the horizontal alignment, the liquid crystal layer in plan view, the refractive index of the rubbing directions n _e1, the refractive index in the direction perpendicular to the rubbing direction n _o1 . On the other hand, the polymer network is, for example, a rod-like, liquid-crystalline UV-curable monomer formed by UV-curing in a vertically aligned state, so that it is rubbed in a plan view regardless of whether a voltage is applied or not. direction refractive index n _o2, the refractive index in the direction perpendicular to the rubbing direction becomes n _o2.

If n _o2 of the examples as well as UV-curable liquid crystal monomer is a starting material for the n _o1 and polymer network liquid crystal molecules constituting the liquid crystal layer is substantially equal so that the appropriate material selection has been made, Focusing on the direction perpendicular to the rubbing direction, the refractive index _{no1 in the} direction perpendicular to the rubbing direction of the liquid crystal layer is substantially equal to the refractive index _{no2 in the} direction perpendicular to the rubbing direction of the polymer network.

  For this reason, focusing on the direction perpendicular to the rubbing direction, the irradiation light from the light source that has reached the liquid crystal element in the state where no voltage is applied (the liquid crystal molecules are horizontally aligned) is the interface between the liquid crystal molecules (liquid crystal layer) and the polymer network. The liquid crystal element (liquid crystal layer) is transmitted without being refracted (scattered).

On the other hand, paying attention to the rubbing direction, the refractive index n _e1 of the rubbing direction of the liquid crystal layer is not consistent with the refractive index n _o2 of the rubbing direction of the polymer network.

  Due to this difference in refractive index, the irradiation light from the light source that has reached the liquid crystal element in a state where no voltage is applied (liquid crystal molecules are horizontally aligned) is rubbed mainly at the interface between the liquid crystal molecules (liquid crystal layer) and the polymer network. The light is refracted (scattered) in a direction perpendicular to the direction and transmitted through the liquid crystal element (liquid crystal layer).

As described above, the liquid crystal layer, the state of the liquid crystal molecules are horizontally aligned rod-like included in the liquid crystal layer, refractive index n _e1 rubbing _direction, the refractive index n _o1 next direction orthogonal to the rubbing direction, whereas In the liquid crystal layer, the refractive index in the rubbing direction is n _o1 and the refractive index in the direction orthogonal to the rubbing direction is n _o1 in a state where the liquid crystal molecules are vertically aligned. Then, the polymer network N, the rubbing direction of the refractive index n _o2, a polymer network in which the direction of the refractive index is n _o2 perpendicular to the rubbing direction, the liquid crystal molecules are not bound to the polymer network.

Therefore, make suitable material selected to n _o2 of ultraviolet curable liquid crystal monomer is a starting material for the n _o1 and polymer network liquid crystal molecules are substantially equal, by forming the vehicle lamp using the liquid crystal element For example, when a voltage is applied to the liquid crystal element (between the transparent electrodes), the light irradiated from the light source hardly scatters in the rubbing direction and the direction orthogonal to the rubbing direction. On the other hand, when no voltage is applied to the liquid crystal element (between the transparent electrodes), the light emitted from the light source is more strongly scattered (anisotropic) in the direction perpendicular to the rubbing direction. Therefore, it is possible to form a wide light distribution pattern in the rubbing direction suitable for the low beam light distribution pattern.

  In other words, according to the first aspect of the present invention, the irradiation light from the same optical system is not always used as in the prior art, but at the time of high beam (when voltage is applied between the transparent electrodes), Light suitable for the light distribution pattern (transmitted light transmitted without scattering) is used, and light suitable for the low beam light distribution pattern (at right angles to the rubbing direction) at low beam (when no voltage is applied between the transparent electrodes) Scattered light that scatters more strongly in the direction in which it is transmitted).

  Therefore, according to the first aspect of the present invention, there is provided a liquid crystal element used for a vehicle lamp capable of forming a more appropriate high beam light distribution pattern and a more appropriate low beam light distribution pattern. Is possible.

  According to the first aspect of the present invention, the degree of scattering in the direction perpendicular to the rubbing direction is adjusted by adjusting the voltage applied between the transparent electrodes by a drive circuit connected from the outside, and a desired distribution is achieved. A liquid crystal element capable of forming an optical pattern can be provided.

According to a second aspect of the present invention, there is provided between the two glass substrates on which the transparent electrode and the alignment film subjected to the rubbing treatment so that the rubbing directions are in an antiparallel relationship with each other, and the two glass substrates. A rod-like liquid crystal molecule having a positive dielectric anisotropy to which a liquid crystalline UV-curable monomer and a photopolymerization reaction initiator are added , and the liquid crystal molecule has the rubbing direction under the condition of a liquid crystal layer thickness of 15 μm. The liquid crystal layer formed between the two glass substrates, and the liquid crystal molecules and the ultraviolet curable monomer are in a horizontally aligned state by injecting liquid crystal molecules that are aligned along A polymer network formed in the liquid crystal layer by irradiating the liquid crystal layer with ultraviolet rays and curing the ultraviolet curable monomer to an extent that does not restrain the liquid crystal molecules; The degree of unconstrained means that the liquid crystal molecules of the liquid crystal layer are vertically aligned when a voltage is applied between the transparent electrodes and horizontally aligned when no voltage is applied between the transparent electrodes. on the order to realize the liquid crystal layer is a liquid crystal molecules are horizontally oriented state of the rod-like contained in the liquid crystal layer, the rubbing direction of the refractive index n _e1, the refractive index in the direction perpendicular to the rubbing direction n _{o1 (where,} n _{e1> n O1),} and the state of the liquid crystal molecules are vertically aligned contained in the liquid crystal layer, the rubbing direction of the refractive index n _o1, the refractive index in the direction perpendicular to the rubbing direction n _The liquid crystal layer is _o1 , and does not contain a chiral agent, and the polymer network has a refractive index in the rubbing direction of ne ₂ and a refractive index in the direction perpendicular to the rubbing direction of n _O2 (however, N _O2 ≈n _O1 ), which is characterized in that the transmitted light is transmitted during the horizontal alignment and anisotropic scattering is generated during the vertical alignment.

According to the second aspect of the present invention, since the liquid crystal molecules are not constrained by the polymer network, when no voltage is applied between the transparent electrodes, the liquid crystal molecules in the liquid crystal layer are aligned horizontally (with respect to the glass substrate). , Horizontal and aligned along the rubbing direction). Since liquid crystal molecules are molecules of the rod-shaped, in the case where the liquid crystal molecules in the horizontal alignment, the liquid crystal layer in plan view, the refractive index of the rubbing directions n _e1, the refractive index in the direction perpendicular to the rubbing direction n _o1 . On the other hand, the polymer network is formed by, for example, stick-like, liquid crystalline UV-curable monomer being UV-cured in a horizontally aligned state, so that it is rubbed in a plan view regardless of whether a voltage is applied or not. The refractive index in the direction is n _e2 , and the refractive index in the direction orthogonal to the rubbing direction is n _O2 .

Here, when an appropriate material is selected so that the n _{o1 of} the liquid crystal molecules constituting the liquid crystal layer and the n _o2 of the UV-curable liquid crystal monomer that is the starting material of the polymer network are substantially equal, the direction is orthogonal to the rubbing direction. Focusing on the direction in which the liquid crystal layer is rubbed, the refractive index _{no1 in the} direction perpendicular to the rubbing direction of the liquid crystal layer is substantially equal to the refractive index _{no2 in the} direction perpendicular to the rubbing direction of the polymer network. On the other hand, paying attention to the rubbing direction, the refractive index n1 of the liquid crystal layer in the rubbing direction is equal to the refractive index n1 of the polymer network in the rubbing direction.

For this reason, the irradiation light from the light source that has reached the liquid crystal element in a state where no voltage is applied (liquid crystal molecules are horizontally aligned) is hardly refracted (scattered) at the interface between the liquid crystal molecules (liquid crystal layer) and the polymer network ( That is, the light passes through the liquid crystal element (liquid crystal layer) with little scattering in the rubbing direction and the direction orthogonal to the rubbing direction.

On the other hand, when a voltage is applied between the transparent electrodes, since the liquid crystal molecules are not constrained by the polymer network, the liquid crystal molecules in the liquid crystal layer are vertically aligned (attitude perpendicular to the glass substrate). Since liquid crystal molecules are molecules of the rod-shaped, in the case where the liquid crystal molecules becomes vertical alignment liquid crystal layer, in a plan view, the refractive index of the rubbing directions n _o1, the refractive index in the direction perpendicular to the rubbing direction n _o1 . On the other hand, since the polymer network is formed by, for example, curing a rod-shaped UV curable monomer with UV in a horizontally oriented state, it is refracted in the rubbing direction in a plan view regardless of whether a voltage is applied or not. rate is _{n e2,} the refractive index in the direction perpendicular to the rubbing direction becomes _{n o2.}

Here, when an appropriate material is selected so that the n _{o1 of} the liquid crystal molecules constituting the liquid crystal layer and the n _o2 of the UV-curable liquid crystal monomer that is the starting material of the polymer network are substantially equal, the direction is orthogonal to the rubbing direction. Focusing on the direction in which the liquid crystal layer is rubbed, the refractive index _{no1 in the} direction perpendicular to the rubbing direction of the liquid crystal layer is substantially equal to the refractive index _{no2 in the} direction perpendicular to the rubbing direction of the polymer network N.

  For this reason, when focusing on the direction orthogonal to the rubbing direction, the irradiation light from the light source that has reached the liquid crystal element in a state where a voltage is applied (the liquid crystal molecules are vertically aligned) is the interface between the liquid crystal molecules (liquid crystal layer) and the polymer network. The liquid crystal element (liquid crystal layer) is transmitted without being refracted (scattered).

On the other hand, paying attention to the rubbing direction, the refractive index n _{o1 in} the rubbing direction of the liquid crystal layer does not coincide with the refractive index _{ne 2 in} the rubbing direction of the polymer network.

  Due to this difference in refractive index, the light emitted from the light source that has reached the liquid crystal element in the state where voltage is applied (liquid crystal molecules are vertically aligned) is rubbed mainly at the interface between the liquid crystal molecules (liquid crystal layer) and the polymer network. The liquid crystal element is refracted (scattered) in a direction perpendicular to the direction.

As described above, according to the second aspect of the invention, the liquid crystal layer, liquid crystal molecules of the rod-like contained in the liquid crystal layer is in a state of horizontal alignment, refractive index of the rubbing directions n _e1, perpendicular to the rubbing direction direction refractive index n _o1. on the other hand, in the state of liquid crystal molecules C is vertically aligned, the refractive index of the rubbing directions n _o1, a liquid crystal layer in which the direction of a refractive index of n _o1 perpendicular to the rubbing direction. The polymer network N, the refractive index of the rubbing directions n _e2, a polymer network in which the direction of the refractive index is n _o2 perpendicular to the rubbing direction, the liquid crystal molecules C is not bound to the polymer network N.

  For this reason, if a vehicle lamp is configured using the liquid crystal element, when no voltage is applied to the liquid crystal element (between the transparent electrodes), the irradiation light from the light source is in the rubbing direction and the direction orthogonal to the rubbing direction. Since it hardly scatters, it is possible to form a light distribution pattern including a spot portion suitable for a high beam light distribution pattern. On the other hand, when a voltage is applied to the liquid crystal element (between transparent electrodes), Since the irradiation light is more strongly scattered (anisotropic scattering) in a direction orthogonal to the rubbing direction, it is possible to form a wide light distribution pattern in the rubbing direction suitable for the low beam light distribution pattern.

  That is, according to the second aspect of the invention, the irradiation light from the same optical system is not always used as in the prior art, but at the time of high beam (when no voltage is applied between the transparent electrodes), Light suitable for the light distribution pattern (transmitted light transmitted without scattering) is used, and light suitable for the low beam light distribution pattern (at right angles to the rubbing direction) at the time of low beam (when voltage is applied between the transparent electrodes) Scattered light that scatters more strongly in the direction in which it is transmitted).

  Therefore, according to the second aspect of the present invention, there is provided a liquid crystal element used for a vehicle lamp capable of forming a more appropriate high beam light distribution pattern and a more appropriate low beam light distribution pattern. Is possible.

  According to the first aspect of the present invention, by adjusting the voltage applied between the transparent electrodes, the degree of scattering in the direction perpendicular to the rubbing direction can be adjusted to form a desired light distribution pattern. It is possible to provide a possible liquid crystal element.

  The invention according to claim 3 includes a projection lens and a light source, and is an illuminance distribution that is inverted and magnified by the projection lens on the focal plane of the projection lens using irradiation light or reflected light from the light source. An optical system for forming the light, a light shielding position that is disposed between the projection lens and the optical system, and shields a part of the irradiation light or reflected light from the optical system, or the irradiation light from the optical system or Between the movable shade that is positioned at one of the open positions that allows the reflected light to pass without being blocked, and between the movable shade and the optical system, irradiation light or reflected light from the optical system passes through the liquid crystal layer. The liquid crystal element according to claim 1 or 2 is arranged so that the rubbing direction is aligned with the vertical direction.

  According to the third aspect of the present invention, it is possible to provide a vehicular lamp capable of forming a more appropriate high beam light distribution pattern and a more appropriate low beam light distribution pattern.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the vehicle lamp which can form the more suitable high beam light distribution pattern, the more suitable low beam light distribution pattern, and the liquid crystal element used for the said vehicle lamp. Become.

It is a figure for demonstrating the structure of the vehicle lamp 100 which is 1st Embodiment of this invention, the optical path (at the time of a low beam) of the irradiation light from the liquid crystal element 10 used for the said vehicle lamp 100, and the light source 20. FIG. It is sectional drawing which represented typically the liquid crystal molecule C in the liquid crystal layer 11g, and the ultraviolet curable liquid crystal monomer M (immediately after liquid crystal injection | pouring, at the time of horizontal alignment). It is sectional drawing which represented typically the liquid crystal molecule C in the liquid crystal layer 11g, and the ultraviolet curable liquid crystal monomer M (at the time of voltage application, vertical alignment, and ultraviolet irradiation). It is sectional drawing which represented typically the liquid crystal molecule C in the liquid crystal layer 11g, the ultraviolet curable liquid crystal monomer M, and the polymer network N (at the time of voltage application). FIG. 5 is a plan view schematically showing the liquid crystal element 10 shown in FIG. 4. It is sectional drawing which represented typically the liquid crystal molecule C in the liquid crystal layer 11g, the ultraviolet curable liquid crystal monomer M, and the polymer network N (at the time of no voltage application). FIG. 7 is a plan view schematically showing the liquid crystal element 10 shown in FIG. 6. It is a figure for demonstrating that the transmittance | permeability of the liquid crystal element 10 improves by voltage application. It is a figure for demonstrating that the transmittance | permeability of the liquid crystal element 10 falls by no voltage application. It is a figure for demonstrating that the spot-like light distribution pattern suitable for the light distribution pattern for high beams is formed with the irradiation light from the light source which permeate | transmits the liquid crystal element 10 by voltage application. It is a figure for demonstrating that a wide light distribution pattern is formed in the rubbing direction suitable for the light distribution pattern for low beams by the irradiation light from the light source which permeate | transmits the liquid crystal element 10 by no voltage application. It is the figure which represented typically a mode that scattering generate | occur | produces in the liquid crystal element 10 of the state which does not apply a voltage. 4 is a graph for explaining an illuminance distribution formed on a focal plane of a projection lens 50. (A) is an example of a light distribution pattern for low beam formed by the vehicular lamp 100, (b) is an example of a light distribution pattern for low beam formed by reflected light reflected by the upper part of the reflecting surface 30, (C) is an example of the low beam light distribution pattern formed by the reflected light reflected by the lower portion of the reflecting surface 30. It is an example of the light distribution pattern for low beams formed by the vehicle lamp 100. It is a figure for demonstrating mainly the optical path (at the time of a high beam) of the irradiation light from the light source 20 of the vehicle lamp 100 which is 1st Embodiment of this invention. (A) is an example of a high beam light distribution pattern formed by the vehicular lamp 100, (b) is an example of a high beam light distribution pattern formed by reflected light reflected by the upper portion of the reflective surface 30, (C) is an example of a high-beam light distribution pattern formed by the reflected light reflected by the lower portion of the reflecting surface 30. It is an example of the light distribution pattern for high beams formed by the vehicle lamp. It is an example of the light distribution pattern formed with the vehicle lamp 100 (without the movable shade 40). 4 is a flowchart for explaining a manufacturing process of the liquid crystal element 10. It is sectional drawing which represented typically the liquid crystal molecule C in the liquid-crystal layer 61g, the ultraviolet curable liquid-crystal monomer M, and the polymer network N (at the time of no voltage application and horizontal alignment). FIG. 22 is a plan view schematically showing the liquid crystal element 60 shown in FIG. 21. It is sectional drawing which represented typically the liquid crystal molecule C in the liquid crystal layer 61g, the ultraviolet curable liquid crystal monomer M, and the polymer network N (at the time of voltage application and vertical alignment). FIG. 24 is a plan view schematically showing the liquid crystal element 60 shown in FIG. 23. It is a figure for demonstrating the vehicle lamp 200 of patent document 1. FIG.

  Hereinafter, a liquid crystal element 10 according to a first embodiment of the present invention and a vehicular lamp 100 using the liquid crystal element 10 will be described with reference to the drawings.

  The liquid crystal element 10 of the present embodiment is a polymer network type liquid crystal element, and is used, for example, in a vehicular lamp 100 as shown in FIG. As shown in FIGS. 2, 3 and the like, the liquid crystal element 10 includes two transparent electrodes 11c and 11d and two horizontal alignment films 11e and 11f which are rubbed so that the rubbing directions are in an antiparallel relationship with each other. Glass substrates 11a and 11b. Between the two glass substrates 11a and 11b, as will be described later, rod-like liquid crystal molecules C having a positive dielectric anisotropy to which a liquid crystal ultraviolet curable liquid crystal monomer M is added are injected. Thus, the liquid crystal layer 11g is formed. In this liquid crystal layer 11g, the ultraviolet curable liquid crystal monomer M is ultraviolet-cured to such an extent that the liquid crystal molecules C are not constrained, whereby a porous (sponge-like) polymer network N is formed over almost the entire region. (See FIG. 4).

  Next, a manufacturing process (Example) of the liquid crystal element 10 will be described with reference to FIG.

  First, ITO as the transparent electrodes 11c and 11d is formed on two glass substrates 11a and 11b (ITO thickness: 2000 mm, glass plate thickness: 0.7 mmt, glass material: blue plate glass) by vapor deposition, sputtering, or the like. (See FIG. 2) A desired ITO pattern was formed by a photolithography process (step S10).

  Next, horizontal alignment films 11e and 11f are formed on the surfaces of the ITOs 11c and 11d (step S11), and the alignment process by rubbing or the like is performed on the horizontal alignment films 11e and 11f between the two glass substrates 11a and 11b. The direction was anti-parallel (step S12). In this example, patterned ITO was used as the transparent electrode of the light control portion (pixel portion in the case of a display).

  Next, a main sealant containing 2 to 5 wt% of a gap control agent was formed on one glass substrate 11a by screen printing or a dispenser (step S13). In the example, since the thickness of the liquid crystal layer 11g is 15 μm, a glass fiber (diameter: 15 μm) was used as a gap control agent. 3 wt% of this glass fiber was added to Mitsui Chemicals sealant ES-7500 to obtain a main sealant. Next, a gap control agent was sprayed on the other glass substrate 11b. In this example, 15 μm plastic balls were sprayed as a gap control agent using a dry gap sprayer.

  Next, the two glass substrates 11a and 11b were overlapped, and heat treatment was performed in a state where a pressure was constantly applied by a press machine or the like to cure the main sealant (step S14). In this example, heat treatment was performed at 150 ° C. for 3 hours. This produced an empty cell having a cell thickness of 15 μm.

Then, the empty cell, the liquid crystal (liquid crystal molecules of the rod-like C), the monomer (liquid of the ultraviolet ray curable liquid crystal monomer M: DIC Corporation _{UCL-001: n o = 1.511} , n e = 1.663), What mixed the photoinitiator was vacuum-injected (refer FIG. 2; step S15). In the present embodiment, as the liquid crystal △ epsilon positive liquid crystal _{(n o = 1.525, n e} = 1.823, △ n = 0.298, Tni = 128 ℃: manufactured by Dainippon Ink and Chemicals) was used . To this liquid crystal, 0.5 to 40 wt% of an acrylate monomer was added. Although depending on the material used, if the amount of the monomer M added is 4 wt% or less, the polymer network N tends not to be formed, and if it is 15 wt% or more, the response of the liquid crystal due to voltage tends to be poor. For this reason, the addition amount of the monomer M is preferably about 4 to 15 wt%. In this example, 10 wt% of monomer M was added. Furthermore, 0.1 to 0.5 wt% of the photopolymerization reaction initiator was added to the monomer M. The photopolymerization reaction initiator is not particularly limited as long as it is a material having sensitivity to ultraviolet rays (around 365 nm). In this example, Irgacure manufactured by Ciba Chemicals was used as a photopolymerization reaction initiator.

  Next, an end sealant was applied to the inlet of the liquid crystal cell and sealed (step 16). If a photocurable end seal is used as the end sealant, it is preferable to use a light shielding mask so that the liquid crystal cell is not directly irradiated with ultraviolet rays. Instead of the photo-curable end seal, a thermosetting end seal agent or a two-liquid mixed type end seal agent may be used.

  Next, a voltage is applied between the transparent electrodes 11c and 11d, and the liquid crystal layer 11g in a state where the liquid crystal molecules C and the ultraviolet curable liquid crystal monomer M are vertically aligned (see FIG. 3) is irradiated with ultraviolet rays through a photomask. The polymer network N was formed by UV-curing the monomer M to such an extent that the liquid crystal molecules C were not restrained (see FIG. 4, step 17, S18). In this example, a photo-alignment device made by Megilo Predation was used. The light source of this apparatus is a high-pressure mercury lamp, but a xenon lamp, a metal halide lamp, a low-pressure mercury lamp, or the like may be used instead. The irradiation intensity of ultraviolet rays was 80 mw / cm 2 (350 nm), and irradiation was performed for 30 seconds (irradiation amount was 2.5 J / cm 2). The voltage applied between the transparent electrodes 11c and 11d is preferably a saturation threshold voltage V90 or higher in the LCD. In the present embodiment, an AC voltage of 10 V (frequency 150 Hz) is applied. In addition, it was confirmed that if the voltage applied between the transparent electrodes 11c and 11d is 10 V or more, it is possible to obtain substantially the same scattering performance.

  In addition, although the case where the irradiation time of ultraviolet rays was 30 seconds was demonstrated, this invention is not limited to this. It was confirmed that it was difficult to obtain high scattering performance when the irradiation time was short, and that it was possible to obtain almost the same scattering performance when the irradiation time was 30 seconds or more.

  Finally, chamfering and cleaning were performed (step S19), and a pin terminal was attached to the extraction electrode (step S20).

  The polymer network type liquid crystal element 10 is completed through the above steps.

  Next, the optical characteristics of the liquid crystal element 10 will be described.

  When the inventors of the present application apply a voltage to the liquid crystal element 10 (between the transparent electrodes 11e and 11f), the irradiation light from the light source that has reached the liquid crystal element 10 is transmitted without being scattered (that is, the transmittance). On the other hand, if no voltage is applied to the liquid crystal element 10, the irradiation light from the light source that has reached the liquid crystal element 10 is scattered and transmitted (that is, the transmittance is reduced). It was found that the scattering is not isotropic scattering but anisotropic scattering that strongly scatters in a direction perpendicular to the rubbing direction (see FIGS. 10 and 11). FIG. 10 shows an example of a light distribution pattern formed by light emitted from a light source that passes through the liquid crystal element 10 in a state where a voltage is applied, and it can be seen that the light is hardly scattered. FIG. 11 is an example of a light distribution pattern formed by light emitted from a light source that passes through the liquid crystal element 10 in a state in which no voltage is applied. The light distribution pattern is strongly scattered (anisotropic scattering) in a direction orthogonal to the rubbing direction. I understand that

  Next, the principle that the liquid crystal element 10 exhibits the optical characteristics will be described.

Since the liquid crystal molecules C are not constrained by the polymer network N, when a voltage is applied to the liquid crystal element 10 (between the transparent electrodes 11c and 11d), the liquid crystal molecules C in the liquid crystal layer 11g are as shown in FIG. , And vertical alignment (perpendicular to the glass substrates 11a and 11b). Since the liquid crystal molecules C are rod-like molecules, when the liquid crystal molecules C are vertically aligned, the liquid crystal layer 11g has a rubbing direction (vertical direction in FIG. 5) in plan view as shown in FIG. refractive index n _o1, the refractive index in the direction perpendicular to the rubbing direction (FIG. 5 in the horizontal direction) is n _o1 of. On the other hand, the polymer network N is formed by ultraviolet curing of a rod-like and liquid crystalline ultraviolet curable liquid crystal monomer M in a vertically aligned state (see FIG. 4). , in plan view, the refractive index of the rubbing directions _{n o2 (where, n O2} ≒ _{n O1),} the refractive index in the direction perpendicular to the rubbing direction becomes _{n o2.}

In this case, paying attention to the direction orthogonal to the rubbing direction (the left-right direction in FIG. 5), the refractive index _{no1 in the} direction orthogonal to the rubbing direction of the liquid crystal layer 11g is the refractive index in the direction orthogonal to the rubbing direction of the polymer network N. The relationship with n _o2 will affect the optical characteristics (almost equal). On the other hand, paying attention to the rubbing direction (vertical direction in FIG. 5), the relationship between the refractive index _no1 of the rubbing direction of the liquid crystal layer 11g and the refractive index _no2 of the rubbing direction of the polymer network N affects the optical characteristics. (Almost equal).

Here, by ultraviolet curing n _o2 of the liquid crystal monomer M is the starting material for the n _o1 and polymer network N of the liquid crystal molecules C constituting the liquid crystal layer 11g performs an appropriate material chosen to be substantially equal, the liquid crystal There is substantially no difference in refractive index between the molecule C and the polymer network N interface.

  For this reason, the irradiation light from the light source that has reached the liquid crystal element 10 in a state where a voltage is applied (the liquid crystal molecules C are vertically aligned) is almost at the interfaces f1 and f2 between the liquid crystal molecules C (the liquid crystal layer 11g) and the polymer network N. The liquid crystal element 10 (liquid crystal layer 11g) is transmitted without being refracted (scattered) (that is, hardly scattered in the rubbing direction and the direction orthogonal to the rubbing direction) (see FIG. 8).

On the other hand, when no voltage is applied to the liquid crystal element 10 (between the transparent electrodes 11c and 11d), since the liquid crystal molecules C are not constrained by the polymer network N, as shown in FIG. 6, the liquid crystal molecules in the liquid crystal layer 11g. C is in a horizontal orientation (a state where the glass substrates 11a and 11b are aligned horizontally and along the rubbing direction). Since the liquid crystal molecules C are rod-like molecules, when the liquid crystal molecules C are horizontally aligned, the liquid crystal layer 11g has a rubbing direction (vertical direction in FIG. 7) in plan view as shown in FIG. refractive index _{n e1,} the refractive index _{n o1 (where,} n _{e1> n O1)} in a direction orthogonal to the rubbing direction (in FIG. 7 the horizontal direction) becomes. On the other hand, the polymer network N is formed by ultraviolet curing of a rod-like and liquid crystalline ultraviolet curable liquid crystal monomer M in a vertically aligned state (see FIG. 4). , in plan view, the refractive index of the rubbing directions n _o2, the refractive index in the direction perpendicular to the rubbing direction becomes n _o2.

Similar to the above example, appropriate materials are selected so that _{no1 of} the liquid crystal molecules constituting the liquid crystal layer 11g and _no2 of the ultraviolet curable liquid crystal monomer M which is the starting material of the polymer network N are substantially equal. In this case, focusing on the direction perpendicular to the rubbing direction (the left-right direction in FIG. 7), the refractive index _{no1 in the} direction perpendicular to the rubbing direction of the liquid crystal layer 11g is the refractive index in the direction perpendicular to the rubbing direction of the polymer network N. n _o2 is substantially (approximately) equal.

  For this reason, when paying attention to the direction orthogonal to the rubbing direction, the irradiation light from the light source that has reached the liquid crystal element 10 in a state where no voltage is applied (the liquid crystal molecules are horizontally aligned) is the liquid crystal molecules C (the liquid crystal layer 11g) and the polymer network. It passes through the liquid crystal element 10 (liquid crystal layer 11g) with almost no refraction (scattering) at the interface f2 with N.

On the other hand, paying attention to the rubbing direction (vertical direction in FIG. 7), the refractive index n _e1 of the liquid crystal layer 11g in the rubbing direction does not coincide with the refractive index _no2 of the rubbing direction of the polymer network N.

  Due to this difference in refractive index, the irradiation light from the light source that has reached the liquid crystal element 10 in a state where no voltage is applied (the liquid crystal molecules C are horizontally aligned) is between the liquid crystal molecules C (the liquid crystal layer 11g) and the polymer network N. At the interface f1, the light is refracted (scattered) mainly in a direction perpendicular to the rubbing direction (left and right direction in FIG. 7) and transmitted through the liquid crystal element 10 (liquid crystal layer 11g).

  As a result of further investigation based on the above knowledge, the inventor of the present application, when a vehicle lamp is configured using the liquid crystal element 10, applies a voltage to the liquid crystal element 10 (between the transparent electrodes 11c and 11d). The light emitted from the light source hardly scatters in the rubbing direction and the direction orthogonal to the rubbing direction, so that it is possible to form a light distribution pattern including a spot portion suitable for a high beam light distribution pattern, while the liquid crystal When no voltage is applied to the element 10 (between the transparent electrodes 11c and 11d), the irradiation light from the light source scatters more strongly in the direction orthogonal to the rubbing direction (anisotropic scattering). The idea is that a wide light distribution pattern (see FIG. 10) can be formed in a direction orthogonal to a suitable rubbing direction, and this is shown in FIGS. It was verified as.

  FIG. 10 is an example of a light distribution pattern formed by light emitted from a light source that passes through the liquid crystal element 10 in a state where a voltage is applied. Referring to FIG. 10, it can be seen that the light distribution pattern is a spot-like light distribution pattern that hardly scatters, and is suitable for a high-beam light distribution pattern. FIG. 11 is an example of a light distribution pattern formed by irradiation light from a light source that passes through the liquid crystal element 10 in a state where no voltage is applied. Referring to FIG. 11, the light distribution pattern is a light distribution pattern that strongly scatters (anisotropic scattering) in a direction orthogonal to the rubbing direction (left and right direction in FIG. 11), and is suitable for a low beam light distribution pattern. I understand that.

  Next, a vehicle lamp 100 using the liquid crystal element 10 will be described with reference to FIG.

  A vehicular lamp 100 using the liquid crystal element 10 is applied to a headlamp of a vehicle such as an ordinary passenger car, a light vehicle, a truck, or a bus. As shown in FIG. 1, the liquid crystal element 10, the light source 20, and the reflection lamp are used. A surface 30, a movable shade 40, a projection lens 50, and the like are provided. The light source 20 and the reflecting surface 30 correspond to the optical system of the present invention.

  As shown in FIG. 1, the liquid crystal element 10 is disposed between the reflective surface 30 and the shade 40 so that the reflected light from the reflective surface 30 is transmitted. The liquid crystal element 10 is disposed in such a posture that the glass substrates 11a and 11b are orthogonal to the optical axis AX and the rubbing direction coincides with the vertical direction. By arranging in this way, as will be described later, the light distribution pattern wide in the direction orthogonal to the rubbing direction (horizontal direction in the present embodiment) that is easy for the driver during low beam traveling to visually recognize the surroundings (see FIG. 15). ) Can be formed. In addition, the reflected light from the reflecting surface 30 that is strongly scattered in the direction orthogonal to the rubbing direction emitted from the liquid crystal element 10 (liquid crystal layer 11 g) arranged as described above is not blocked by the movable shade 40 and is not projected by the projection lens. Since the light is incident on the light 50, the light use efficiency is improved.

  The light source 20 is, for example, an incandescent bulb, a halogen lamp, HID, LED, or the like. FIG. 1 shows an example in which a halogen lamp is used as the light source 20. Irradiation light from the light source 20 reaches the reflecting surface 30 disposed so as to cover the light source 20.

  The reflection surface 30 is a reflection surface for reflecting the irradiation light from the light source 20 that has reached the reflection surface 30 and forming an illuminance distribution on the focal plane of the projection lens 50. For example, the reflecting surface 30 is a spheroid reflecting surface in which the first focal point is set in the vicinity of the light source 20 and the second focal point is set in the vicinity of the upper end edge of the shade 40.

  The movable shade 40 is a light shielding member for shielding the lower half of the reflected light from the reflective surface 30. The movable shade 40 has an operation of an actuator (not shown) coupled to the movable shade 40 to block a reflected light from the reflecting surface 30 (at the time of low beam) or without blocking the reflected light from the reflecting surface 30. It is located at one of the open positions (high beam) to pass. The movable shade 40 is arranged so that the upper end edge is located in the vicinity of the focal point of the projection lens 50 when it is located at the light shielding position.

  When no voltage is applied to the liquid crystal element 10 (during low beam), the reflected light from the reflecting surface 30 is more strongly scattered (anisotropic scattering; see FIGS. 1 and 12) in the direction orthogonal to the rubbing direction. For example, an illuminance distribution as shown by a thin line in FIG. 13 is formed on the focal plane of the projection lens 50 through the liquid crystal element 10 without applying the voltage. In FIG. 13, the thin line represents the illuminance distribution when no voltage is applied to the liquid crystal element 10 (low beam), and the thick line represents the illuminance distribution when no voltage is applied to the liquid crystal element 10 (high beam). Referring to FIG. 13, it can be seen that the central luminous intensity at the time of the low beam is about ½ compared to that at the time of the high beam. This reduced amount is scattered in a direction perpendicular to the rubbing direction.

  This illuminance distribution is inverted and enlarged and projected by the projection lens 50, and has a clear cut-off line CL as shown in FIGS. 14A and 15, for example, orthogonal to the rubbing direction suitable for the low beam light distribution pattern. A light distribution pattern that is wide in the direction in which it is performed (horizontal direction in the present embodiment) is formed. Referring to FIG. 15, the light distribution pattern has a lower central MAX luminous intensity than the high beam light distribution pattern (FIG. 18), and spreads in a direction perpendicular to the rubbing direction, which is suitable for the low beam light distribution pattern. I understand that 14B is an example of a low beam light distribution pattern formed by the reflected light reflected by the upper part of the reflecting surface 30, and FIG. 14C is reflected by the lower part of the reflecting surface 30. It is an example of the light distribution pattern for low beams formed by the reflected light made. When the movable shade 40 is not provided, a wide light distribution pattern is formed in a direction orthogonal to the rubbing direction that does not have a clear cut-off line, as shown in FIG.

  On the other hand, when a voltage is applied to the liquid crystal element 10 (during high beam), the reflected light from the reflecting surface 30 is transmitted through the liquid crystal element 10 in the state where the voltage is applied with almost no scattering (see FIG. 16). For example, an illuminance distribution as shown by a thick line in FIG. 13 is formed on the focal plane of the projection lens 50.

  This illuminance distribution is inverted and enlarged and projected by the projection lens 50 to form a light distribution pattern including a spot portion suitable for a high beam light distribution pattern, for example, as shown in FIGS. Referring to FIG. 18, it can be seen that the central MAX luminous intensity is high (ie, a spot portion is formed) as compared with the low beam light distribution pattern (FIG. 15), which is suitable for the high beam light distribution pattern. . FIG. 17B is an example of a high beam light distribution pattern formed by the reflected light reflected by the upper part of the reflecting surface 30, and FIG. 17C is reflected by the lower part of the reflecting surface 30. It is an example of the light distribution pattern for high beams formed by the reflected light made.

As described above, according to the present embodiment, the liquid crystal layer 11g has the refractive index in the rubbing direction _{ne 1} , and the rubbing direction orthogonal to the rubbing direction, with the rod-like liquid crystal molecules C included in the liquid crystal layer 11g in a horizontal alignment state. The refractive index of the rubbing direction becomes _no1 (see FIGS. 6 and 7), while the liquid crystal molecules C included in the liquid crystal layer 11g are vertically aligned, the refractive index of the rubbing direction is _no1 and orthogonal to the rubbing direction. This is a liquid crystal layer having a refractive index of n _o1 in the direction in which the light is applied. Then, the polymer network N, the rubbing direction of the refractive index n _o2, a polymer network in which the direction of the refractive index is n _o2 perpendicular to the rubbing direction, the liquid crystal molecules C is not bound to the polymer network N.

Therefore, make suitable material selected to n _o2 of ultraviolet curable liquid crystal monomer is a starting material for the n _o1 and polymer network N of the liquid crystal molecules C are substantially equal, by using a liquid crystal element 10 of the present embodiment If the vehicular lamp 100 or the like is configured, when a voltage is applied to the liquid crystal element 10 (between the transparent electrodes 11c and 11d), the irradiation light from the light source 20 is almost scattered in the rubbing direction and the direction orthogonal to the rubbing direction. Therefore, it is possible to form a light distribution pattern including a spot portion suitable for the high beam light distribution pattern. On the other hand, when no voltage is applied to the liquid crystal element 10 (between the transparent electrodes 11c and 11d), the light source The irradiation light from 20 scatters more strongly in the direction orthogonal to the rubbing direction (anisotropic scattering), so it is suitable for low beam light distribution patterns. It is possible to form a wide light distribution pattern in a direction perpendicular to.

  That is, according to the present embodiment, the irradiation light from the same optical system is not always used as in the prior art, but at the time of high beam (when a voltage is applied between the transparent electrodes 11c and 11d), the distribution for high beam is performed. Light suitable for the light pattern (transmitted light that passes through the liquid crystal element 10 without scattering) is used, and at the time of low beam (when no voltage is applied between the transparent electrodes 11c and 11d), it is suitable for the light distribution pattern for low beam. Light (scattered light that scatters more strongly in a direction perpendicular to the rubbing direction emitted from the liquid crystal element 10) can be used.

  Therefore, according to the present embodiment, the vehicle lamp 100 that can electrically switch a more appropriate high-beam light distribution pattern, a more appropriate low-beam light distribution pattern, and the liquid crystal element 10 used in the vehicle lamp 100. Can be provided.

  Further, according to the present embodiment, the voltage applied to the liquid crystal element 10 (between the transparent electrodes 11c and 11d) is adjusted by a drive circuit (not shown) connected from the outside, thereby scattering in the direction orthogonal to the rubbing direction. It is possible to form a desired light distribution pattern by adjusting the degree of.

  In addition, according to the present embodiment, for example, when a vehicle equipped with the vehicle lamp 100 using the liquid crystal element 10 is traveling on a straight road at a high speed, a voltage is applied to the liquid crystal elements 10 and 60. When forming a high beam light distribution pattern with high MAX luminous intensity and excellent distance visibility while driving on roads with continuous corners such as mountainous areas, a voltage is applied to the liquid crystal element 10. It is possible to form a light distribution pattern for low beam that can irradiate a wide range although it is in a scattering state and has a low MAX luminous intensity.

  In view of fail-safe, it is preferable that the movable shade 40 is configured such that the movable shade 40 returns to the light shielding position and the voltage to the liquid crystal element 10 is turned off when a failure occurs.

  Next, a liquid crystal element 60 according to a second embodiment of the present invention will be described with reference to the drawings.

  The liquid crystal element 60 of the present embodiment is a polymer network type liquid crystal element, and is used, for example, in a vehicular lamp 100 as shown in FIG. As shown in FIG. 21 and the like, the liquid crystal element 60 includes two glass substrates 61a in which transparent electrodes 61c and 61d and alignment films 61e and 61f that are rubbed so that the rubbing directions are in antiparallel relation with each other are laminated. , 61b. Between the two glass substrates 61a and 61b, as described later, rod-like liquid crystal molecules C having positive dielectric anisotropy to which a liquid crystal UV-curable liquid crystal monomer M is added are injected. Thereby, the liquid crystal layer 61g is formed. In this liquid crystal layer 61g, the ultraviolet curable liquid crystal monomer M is cured by ultraviolet rays so as not to constrain the liquid crystal molecules C, so that a porous (sponge-like) polymer network N is formed over almost the entire region. (See FIG. 21).

  Next, a manufacturing process (Example) of the liquid crystal element 60 will be described.

  The liquid crystal element 60 can be manufactured in steps S10 to S20 in which step S17 is omitted among the manufacturing steps (examples) described with reference to FIG. 20 in the first embodiment. Except for omitting step S17, the process is the same as that of steps S10 to S20 already described.

  Next, the optical characteristics of the liquid crystal element 60 will be described.

  The inventors of the present application indicate that the liquid crystal element 60 performs the reverse operation of the liquid crystal element 10 of the first embodiment, that is, if no voltage is applied to the liquid crystal element 60 (between the transparent electrodes 61c and 61d), Light emitted from the light source that has reached the liquid crystal element 60 is transmitted without being scattered (that is, the transmittance is increased; see FIG. 8). On the other hand, when a voltage is applied to the liquid crystal element 60, Irradiated light from the light source that has arrived is scattered and transmitted (that is, the transmittance is reduced; see FIG. 9), and the scattering is not isotropic scattering, but is stronger in the direction perpendicular to the rubbing direction. It was found that the scattering is anisotropic scattering.

  Next, the principle that the liquid crystal element 60 exhibits the optical characteristics will be described.

Since the liquid crystal molecules C are not constrained by the polymer network N, when no voltage is applied to the liquid crystal element 60 (between the transparent electrodes 61c and 61d), as shown in FIG. 21, the liquid crystal molecules C in the liquid crystal layer 61g are , And horizontal alignment (a state where the glass substrates 11a and 11b are aligned horizontally and along the rubbing direction). Since the liquid crystal molecules C are rod-like molecules, when the liquid crystal molecules C are horizontally aligned, the liquid crystal layer 61g has a rubbing direction (vertical direction in FIG. 22) in plan view as shown in FIG. The refractive index is n _e1 , and the refractive index in the direction orthogonal to the rubbing direction (left and right direction in FIG. 22) is n _o1 (where n _e1 > n _O1 ). On the other hand, the polymer network N is formed by ultraviolet curing of a rod-like and liquid crystalline ultraviolet curable liquid crystal monomer M in a horizontally aligned state (see FIG. 21), and therefore, regardless of whether a voltage is applied or not. In plan view, the refractive index in the rubbing direction is n _e2 , and the refractive index in the direction orthogonal to the rubbing direction is n _o2 (where n _O2 ≈n _O1 ).

Here, if the n _o1 of the liquid crystal molecules C constituting the liquid crystal layer 61 g, n _o2 of ultraviolet curable liquid crystal monomer C which is the starting material for the polymer network N has performed a suitable material selected to be substantially equal, focusing on the direction (in FIG. 22 the horizontal direction) perpendicular to the rubbing direction, the refractive index n _o1 direction orthogonal to the rubbing direction of the liquid crystal layer 61g has a refractive index in the direction of n _o2 perpendicular to the rubbing direction of the polymer network n Substantially (approximately) equal.

  Therefore, the irradiation light from the light source that has reached the liquid crystal element 60 in a state where no voltage is applied (the liquid crystal molecules C are horizontally aligned) is almost at the interfaces f1 and f2 between the liquid crystal molecules C (the liquid crystal layer 61g) and the polymer network N. The liquid crystal element 60 (liquid crystal layer 11g) is transmitted without being refracted (scattered) (that is, hardly scattered in the rubbing direction and the direction orthogonal to the rubbing direction) (see FIG. 8).

On the other hand, when a voltage is applied to the liquid crystal element 60 (between the transparent electrodes 61c and 61d), since the liquid crystal molecules C are not constrained by the polymer network N, as shown in FIG. 23, the liquid crystal molecules in the liquid crystal layer 11g. C is vertical alignment (perpendicular to the glass substrates 11a and 11b). Since the liquid crystal molecules C are rod-like molecules, when the liquid crystal molecules C are vertically aligned, the liquid crystal layer 61g has a rubbing direction (vertical direction in FIG. 24) in plan view as shown in FIG. refractive index _{n o1,} the refractive index in the direction perpendicular to the rubbing direction (FIG. 24 in the horizontal direction) is _{n o1} of. On the other hand, the polymer network N is formed by ultraviolet curing of a rod-like and liquid crystalline ultraviolet curable liquid crystal monomer M in a horizontally aligned state (see FIG. 21), and therefore, regardless of whether a voltage is applied or not. , in plan view, the refractive index of the rubbing directions n _e2, the refractive index in the direction perpendicular to the rubbing direction becomes n _o2.

Here, the n _o1 of the liquid crystal molecules C constituting the liquid crystal layer 61 g, if n _o2 of ultraviolet curable liquid crystal monomer is a starting material of the polymer network N has performed a suitable material selected to be substantially equal, rubbing Paying attention to the direction orthogonal to the direction (left and right direction in FIG. 24), the refractive index _{no1 in the} direction orthogonal to the rubbing direction of the liquid crystal layer _61g is equal to the refractive index _{no2 in the} direction orthogonal to the rubbing direction of the polymer network N. Become.

  For this reason, focusing on the direction orthogonal to the rubbing direction, the irradiation light from the light source that has reached the liquid crystal element 60 in a state where a voltage is applied (the liquid crystal molecules are vertically aligned) is the liquid crystal molecules C (liquid crystal layer 61g) and the polymer network. It passes through the liquid crystal element 60 (liquid crystal layer 11g) with almost no refraction (scattering) at the interface f2 with N.

On the other hand, paying attention to the rubbing direction (FIG. 24 in the vertical direction), the refractive index n _o1 of the rubbing direction of the liquid crystal layer 61g is not match the refractive index n _e2 rubbing direction of the polymer network N.

  Due to this difference in refractive index, the irradiation light from the light source that has reached the liquid crystal element 10 in a state in which a voltage is applied (the liquid crystal molecules C are vertically aligned) is generated between the liquid crystal molecules C (the liquid crystal layer 61g) and the polymer network N. At the interface f1, the light is refracted (scattered) mainly in a direction orthogonal to the rubbing direction (the left-right direction in FIG. 24) and is transmitted through the liquid crystal element 10 (liquid crystal layer 11g).

  As a result of further investigation based on the above knowledge, the inventor of the present application has found that the liquid crystal element 60 (between the transparent electrodes 61c and 61d) can be formed by configuring the vehicle lamp using the liquid crystal element 60 as in the first embodiment. When no voltage is applied to the light source, the light emitted from the light source hardly scatters in the rubbing direction and the direction orthogonal to the rubbing direction, so that a light distribution pattern including a spot portion suitable for the high beam light distribution pattern is formed. On the other hand, when a voltage is applied to the liquid crystal element 60 (between the transparent electrodes 61c and 61d), the irradiation light from the light source scatters more strongly in the direction perpendicular to the rubbing direction (anisotropic scattering). Therefore, with the idea that a wide light distribution pattern can be formed in a direction orthogonal to the rubbing direction suitable for the low beam light distribution pattern, this is shown in FIG. It was verified in the same manner as shown in 11. The lamp using the liquid crystal element 60 has the same configuration as that shown in FIG.

As described above, according to the present embodiment, the liquid crystal layer 61g has the refractive index in the rubbing direction _{ne 1} and the rubbing direction orthogonal to the rod-shaped liquid crystal molecules C included in the liquid crystal layer 61 in the horizontal alignment state. direction refractive index n _o1 next to (see FIG. 21, FIG. 22), whereas, in the state of liquid crystal molecules C is vertically aligned, the refractive index of the rubbing directions n _o1, the refractive index in the direction perpendicular to the rubbing direction n _The liquid crystal layer becomes _o1 (see FIGS. 23 and 24). The polymer network N, the refractive index of the rubbing directions n _e2, a polymer network in which the direction of the refractive index is n _o2 perpendicular to the rubbing direction (see FIGS. 21 to 24), the liquid crystal molecules C is the polymer network N is not restrained.

  Therefore, if the vehicle lamp 100 or the like is configured using the liquid crystal element 60 of the present embodiment, the light emitted from the light source 20 is applied when no voltage is applied to the liquid crystal element 60 (between the transparent electrodes 61c and 61d). Hardly scatters in the rubbing direction and the direction orthogonal to the rubbing direction, so that it is possible to form a light distribution pattern including a spot portion suitable for the high beam light distribution pattern, while the liquid crystal element 60 (transparent electrode 61c, 61b), the light emitted from the light source 20 scatters more strongly in the direction perpendicular to the rubbing direction (anisotropic scattering), so that it is wide in the rubbing direction suitable for the low beam light distribution pattern. It is possible to form a simple light distribution pattern.

  That is, according to the present embodiment, the irradiation light from the same optical system is not always used as in the prior art, but at the time of high beam (when no voltage is applied between the transparent electrodes 61c and 61d), the distribution for high beam is performed. Using light suitable for the light pattern (transmitted light that passes through the liquid crystal element 60 without scattering), and suitable for the low-beam light distribution pattern during low beam (when voltage is applied between the transparent electrodes 61c and 61d) Light (scattered light that scatters more strongly in a direction perpendicular to the rubbing direction emitted from the liquid crystal element 10) can be used.

  Therefore, according to the present embodiment, the vehicle lamp 100 that can electrically switch a more appropriate high beam light distribution pattern, a more appropriate low beam light distribution pattern, and the liquid crystal element 60 used in the vehicle lamp 100. Can be provided.

  Further, according to the present embodiment, the voltage applied to the liquid crystal element 10 (between the transparent electrodes 11c and 11d) is adjusted by a drive circuit (not shown) connected from the outside, thereby scattering in the direction orthogonal to the rubbing direction. It is possible to form a desired light distribution pattern by adjusting the degree of.

  In addition, according to the present embodiment, for example, when a vehicle equipped with the vehicle lamp 100 using the liquid crystal element 10 is traveling on a straight road at a high speed, a voltage is applied to the liquid crystal elements 10 and 60. When forming a high beam light distribution pattern with high MAX luminous intensity and excellent distance visibility while driving on roads with continuous corners such as mountainous areas, a voltage is applied to the liquid crystal element 10. It is possible to form a light distribution pattern for low beam that can irradiate a wide range although it is in a scattering state and has a low MAX luminous intensity.

  Next, a modified example will be described.

  In each of the embodiments described above, the liquid crystal element 10 (the same applies to the liquid crystal element 60) has been described such that the direction orthogonal to the rubbing direction is aligned with the horizontal direction, but the present invention is not limited to this. For example, the liquid crystal element 10 (the same applies to the liquid crystal element 60) may be arranged in a posture in which the direction orthogonal to the rubbing direction is shifted by about 10 ° from the horizontal direction.

  Even if it is arranged in this way, a wide light distribution pattern (see FIG. 15) in the direction orthogonal to the rubbing direction (horizontal direction in the present embodiment) that makes it easy for the driver during low beam traveling to visually recognize the surroundings. Is possible. In addition, the reflected light from the reflecting surface 30 that is strongly scattered in the direction orthogonal to the rubbing direction emitted from the liquid crystal element 10 (liquid crystal layer 11 g) arranged as described above is not blocked by the movable shade 40 and is not projected by the projection lens. Since the light is incident on the light 50, the light use efficiency is improved.

  Further, for example, the liquid crystal element 10 (the same applies to the liquid crystal element 60) may be arranged in a posture in which the rubbing direction coincides with the horizontal direction. Even if it arrange | positions in this way, compared with the light distribution pattern for high beams (FIG. 18), it becomes possible to reduce a central MAX luminous intensity.

  The above embodiment is merely an example in all respects. The present invention is not construed as being limited to these descriptions. The present invention can be implemented in various other forms without departing from the spirit or main features thereof.

  DESCRIPTION OF SYMBOLS 100 ... Vehicle lamp, 10 (60) ... Liquid crystal element, 11a, 11b (61a, 61b) ... Glass substrate, 11c, 11d (61c, 61d) ... Transparent electrode, 11e, 11f (61e, 61f) ... Alignment film, 11 g (61 g): liquid crystal layer, 20: light source, 30: reflecting surface, 40: movable shade, 50: projection lens, C: liquid crystal molecule, M: UV curable liquid crystal monomer, N: polymer network

Claims (3)

Two glass substrates on which a transparent electrode and a horizontal alignment film that has been rubbed so that the rubbing directions are in an antiparallel relationship with each other are laminated,
A rod-like liquid crystal molecule having a positive dielectric anisotropy in which a rod-like liquid crystalline UV curable monomer and a photopolymerization reaction initiator are added between the two glass substrates, and the liquid crystal layer thickness is 15 μm. A liquid crystal layer formed between the two glass substrates by injecting liquid crystal molecules in a state where the liquid crystal molecules are aligned along the rubbing direction under conditions ;
The liquid crystal layer in a state where the liquid crystal molecules and the ultraviolet curable monomer are vertically aligned are irradiated with ultraviolet rays, and the ultraviolet curable monomer is ultraviolet cured to such an extent that the liquid crystal molecules are not restrained. A polymer network formed in the layers;
With
The non-constrained level is a level that realizes that the liquid crystal molecules of the liquid crystal layer are vertically aligned when a voltage is applied between the transparent electrodes and horizontally aligned when no voltage is applied between the transparent electrodes. Yes,
The liquid crystal layer has a rod-like liquid crystal molecule contained in the liquid crystal layer in a horizontal alignment state, a refractive index in the rubbing direction is n _e1 , and a refractive index in a direction perpendicular to the rubbing direction is n _o1 (provided that n _e1 > n _O1), and the state of the liquid crystal molecules contained in the liquid crystal layer is vertically aligned, the rubbing direction of the refractive index n _o1, direction of the refractive index n _o1 becomes perpendicular to the rubbing direction and a chiral agent A liquid crystal layer that does not contain
The polymer network, the refractive index of the rubbing direction n _{o2 (where,} n _O2 ≒ n _O1), the refractive index in the direction perpendicular to the rubbing direction is a polymer network comprising a n _o2, the relative transmitted rays A liquid crystal element, wherein transmission occurs during vertical alignment and anisotropic scattering occurs during horizontal alignment. Two glass substrates on which a transparent electrode and an alignment film that has been rubbed so that the rubbing direction is in an antiparallel relationship with each other are laminated,
A rod-like liquid crystal molecule having a positive dielectric anisotropy in which a rod-like liquid crystalline UV curable monomer and a photopolymerization reaction initiator are added between the two glass substrates, and the liquid crystal layer thickness is 15 μm. A liquid crystal layer formed between the two glass substrates by injecting liquid crystal molecules in a state where the liquid crystal molecules are aligned along the rubbing direction under conditions ;
The liquid crystal layer in a state where the liquid crystal molecules and the ultraviolet curable monomer are horizontally aligned are irradiated with ultraviolet rays, and the ultraviolet curable monomer is ultraviolet cured to such an extent that the liquid crystal molecules are not restrained. A polymer network formed in the layers;
With
The non-constrained level is a level that realizes that the liquid crystal molecules of the liquid crystal layer are vertically aligned when a voltage is applied between the transparent electrodes and horizontally aligned when no voltage is applied between the transparent electrodes. Yes,
The liquid crystal layer has a rod-like liquid crystal molecule contained in the liquid crystal layer in a horizontal alignment state, a refractive index in the rubbing direction is n _e1 , and a refractive index in a direction perpendicular to the rubbing direction is n _o1 (provided that n _e1 > n _O1), and the state of the liquid crystal molecules contained in the liquid crystal layer is vertically aligned, the rubbing direction of the refractive index n _o1, direction of the refractive index n _o1 becomes perpendicular to the rubbing direction and a chiral agent A liquid crystal layer that does not contain
The polymer network is a polymer network in which the refractive index in the rubbing direction is n _e2 and the refractive index in the direction orthogonal to the rubbing direction is n _O2 (where n _O2 ≈n _O1 ), A liquid crystal element, wherein transmission occurs during horizontal alignment and anisotropic scattering occurs during vertical alignment. A projection lens;
An optical system that includes a light source and forms an illuminance distribution that is inverted and enlarged and projected by the projection lens on the focal plane of the projection lens using irradiation light or reflected light from the light source;
A light shielding position that is disposed between the projection lens and the optical system and shields a part of the irradiation light or reflected light from the optical system or allows the irradiation light or reflected light from the optical system to pass through without being blocked. A movable shade positioned in one of the open positions;
The liquid crystal element according to claim 1, wherein the liquid crystal element is disposed between the movable shade and the optical system so that irradiation light or reflected light from the optical system is transmitted through the liquid crystal layer;
With
The vehicular lamp, wherein the liquid crystal element is arranged in a posture in which the rubbing direction coincides with a vertical direction.