JP2021122005A - Signal lamp and unit for signal lamp - Google Patents

Abstract

To provide a signal lamp capable of performing adjustment so as to reduce a reflectivity on a road surface, and a unit for a signal lamp capable of performing adjustment so as to reduce a reflectivity on a road surface.SOLUTION: A signal lamp comprises a light source and a polarizing unit provided on an optical path for light from the light source, and the polarizing unit has a transmission axis for transmitting vertically polarized light. A unit for a signal lamp comprises a polarizing unit that transmits vertically polarized light, and a transparent base material provided on at least one of a first surface of the polarizing unit and a second surface opposite to the first surface. The first surface and the second surface are provided on the optical path for vertically polarized light.SELECTED DRAWING: Figure 2

Description

The present invention relates to a signal lamp and a unit for a signal lamp.

Many signal lamps (also called traffic lights, see Patent Document 1) are installed on the road in order to allow the passage of automobiles and the like safely and smoothly. The signal lamp emits light containing traffic information toward the automobile, but when the road surface is frozen or wet with rainwater, the light from the signal lamp is easily reflected by the road surface. NS. Sensing cameras for automobile drivers and automatic braking will simultaneously see the direct light from the signal lamp and the light from the signal lamp reflected by the road surface. As a result of simultaneously visually recognizing the direct light from the signal lamp and the reflected light from the road surface, the driver and the sensing camera may confuse these lights with each other and visually recognize them. For example, the driver and the sensing camera may mistakenly recognize the reflected light from the road surface as the direct light from the signal lamp.

Japanese Unexamined Patent Publication No. 9-265806

However, in the prior art (for example, Patent Document 1), regarding the technical idea of reducing the amount of reflected light from the road surface as a means for preventing confusion between the direct light from the signal lamp and the reflected light from the road surface. Is not disclosed.

The signal lamp according to one aspect of the present invention includes a light source and a polarizing unit provided on the optical path of the light from the light source, and the polarizing unit has a transmission axis for transmitting vertically polarized light. ..

Further, the signal lamp unit according to one aspect of the present invention has a polarizing portion for transmitting vertically polarized light, and at least on the first surface of the polarizing portion and on the second surface opposite to the first surface. A transparent base material provided in one is provided, and the first surface and the second surface are provided on the optical path of vertically polarized light.

According to one aspect of the present invention, adjustments can be made to reduce the reflectance of the reflected light from the road surface.

FIG. 1 is a schematic view showing the appearance of a signal lamp according to an embodiment of the present invention and a vehicle on a road surface. FIG. 2A is a front view of the signal lamp according to the embodiment of the present invention, and FIG. 2B is a cross-sectional view taken along the line IIb-IIb of FIG. 2A. FIG. 3A is a diagram showing a light source and a polarizing portion of the signal lamp according to the embodiment of the present invention, and FIG. 3B is a diagram showing a transmission axis of the polarizing portion according to the embodiment of the present invention. It is a figure which shows the relationship between the direction and the direction of the plane of polarization of light from a light source. FIG. 4 is a diagram showing the road surface layer reflectance of light from a signal lamp according to an embodiment of the present invention. FIG. 5A is a plan view of the signal lamp unit according to the embodiment of the present invention, and FIG. 5B is a side view of the signal lamp unit according to the embodiment of the present invention. FIG. 6A is a plan view showing the appearance of the viewing angle control unit of the signal lamp unit according to the embodiment of the present invention, and FIG. 6B is a VIb-VIb of FIG. 6A. It is a cross-sectional view along the line. 7 (a) and 7 (b) are schematic views showing the light from the signal lamp according to the embodiment of the present invention and the vehicle on the road surface. FIG. 8A is a diagram showing a measurement system for the road surface reflectance of the signal lamp according to the first embodiment, and FIG. 8B is a diagram showing the road surface reflectance of the signal lamp according to Comparative Example 1. It is a figure which shows the measurement system. In FIG. 9 (a) is a diagram showing the luminance (cd / ^{m 2)} of the reflected light in the first embodiment, in FIG. 9 (b), the brightness of the reflected light in Comparative Example 1 (cd ^{/ m} 2) It is a figure which shows. FIG. 10 is a diagram showing the results of luminance measurement in Example 1 and Comparative Example 1.

The signal lamp according to one aspect of the embodiment includes a light source and a polarizing unit provided on the optical path of the light from the light source, and the polarizing unit has a transmission axis for transmitting vertically polarized light. ..

The polarizing portion of this signal lamp has a transmission axis for transmitting vertically polarized light. Vertically polarized light is light in the polarization direction that can reduce the intensity of reflected light from the road surface as compared with horizontally polarized light. That is, in this signal lamp, among the light from the light source, the amount of light emitted in the polarization direction that can reduce the intensity of the reflected light from the road surface is the polarization direction in which it is difficult to reduce the intensity of the reflected light from the road surface. It can be adjusted so that it is larger than the amount of light emitted from the light, and the reflectance on the road surface can be reduced.

In the signal lamp according to one aspect of the embodiment, the longitudinally polarized light has a plane of polarization in a direction of an angle of less than 45 degrees with the normal direction of the road surface when viewed from the direction along the optical path. May be good. As a result, the reflectance of the light from the signal lamp on the road surface can be reduced.

In the signal lamp according to one aspect of the embodiment, the polarizing portion may be a reflective polarizer. As a result, the intensity of vertically polarized light passing through the polarized light can be increased.

In the signal lamp according to one aspect of the embodiment, the effective transmittance of the reflective polarizer may be 1.0 to 2.0. As a result, the vertically polarized light emitted from the polarizing portion can obtain high light intensity.

The signal lamp according to one aspect of the embodiment further includes a transparent base material provided on the optical path, and the transparent base material is on the first surface of the polarizing portion and on the second surface opposite to the first surface. At least one is provided, and the first surface and the second surface may be provided on the optical path. This improves the weather resistance of the signal lamp.

In the signal lamp according to one aspect of the embodiment, the transparent substrate may be a low retardation material. As a result, the polarized state of the light emitted from the polarizing unit can be effectively maintained.

The signal lamp according to one aspect of the embodiment may further include a viewing angle control unit provided on the optical path. This makes it easier for vehicles on the road surface to visually recognize only the necessary traffic information.

In the signal lamp according to one aspect of the embodiment, the viewing angle control unit may have a louver layer in which the light transmitting portion and the light blocking portion are alternately arranged. This makes it easier for vehicles on the road surface to see only the necessary traffic information.

The signal lamp unit according to one aspect of the embodiment includes a polarizing portion for transmitting vertically polarized light, and at least one on the first surface of the polarizing portion and on the second surface opposite to the first surface. The first surface and the second surface are provided on the optical path of vertically polarized light.

According to this signal lamp unit, since the polarizing unit has a transmission axis for transmitting vertically polarized light, the intensity of the reflected light from the road surface among the light from the light source of the signal lamp can be reduced. The amount of light emitted from the road surface can be adjusted so that the intensity of the reflected light from the road surface is larger than the amount of light emitted from the laterally polarized light, which is difficult to reduce. In the signal lamp unit, the polarization state of the light from the light source can be controlled by the polarizing unit to reduce the intensity of the reflected light from the road surface, and the transparent base material improves the weather resistance of the signal lamp unit.

In the signal lamp unit according to one aspect of the embodiment, the polarizing unit may be a reflective polarizer. As a result, the intensity of vertically polarized light passing through the polarized light can be increased.

As used herein, the term "low retardation material" refers to a material having a small in-plane retardation (Re) value and easily maintaining the polarized state of transmitted light. The "reflected light from the road surface" refers to the reflected light reflected by the interface between the water layer formed on the road surface and the air, and the reflectance of this reflected light is referred to as the "road surface". It is called "layer reflectance". In the following description, "reflected light from the road surface" is referred to as "road surface layer reflected light" for convenience.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. In the drawings below, the scale of each member is appropriately changed in order to make each member recognizable. Further, in the description of the drawings, the same or equivalent elements are designated by the same reference numerals, and duplicate description will be omitted. In the present embodiment, the X-axis, the Y-axis, and the Z-axis are conveniently set in the figure for subsequent explanation.

FIG. 1 is a schematic view showing the appearance of a signal lamp according to an embodiment and a vehicle on a road surface. FIG. 2A is a front view of the signal lamp according to the embodiment, and FIG. 2B is a cross-sectional view taken along the line IIb-IIb of FIG. 2A. FIG. 3A is a diagram showing a light source and a polarizing portion of the signal lamp according to the embodiment, and FIG. 3B is a direction of a transmission axis of the polarizing portion according to the embodiment and a direction from the light source. It is a figure which shows the relationship with the direction of the polarization plane of light. In FIG. 3A, the light source and the polarizing portion are drawn separately in order to show how the light from the light source passes through the polarizing portion. The light source and the polarizing portion may be separated from each other or may be in contact with each other.

As shown in FIG. 1, the signal lamp 1 is provided on the road surface 6 of the road 5, for example, supported by the signal pillar 3. In the signal lamp 1, the direction of the signal lamp 1 is adjusted so that light can be emitted toward the vehicle 7 on the road surface 6 of the road 5. The light L1 from the signal lamp 1 is, for example, red, yellow, and blue (substantially green) light, and includes traffic information for the vehicle 7.

The light L1 from the signal lamp 1 is emitted by the optical path RT1. When the light L1 from the signal lamp 1 is emitted to the outside of the signal lamp 1, it gradually diffuses and heads directly to the vehicle 7 and at the same time, to, for example, the road surface 6. In FIG. 1, among the light L1 from the signal lamp 1, the light L3 directly toward the vehicle 7 is represented by the optical path RT3, and the light L5 toward the road surface 6 is represented by the optical path RT5. The light L5 is reflected by, for example, the road surface 6a located between the signal lamp 1 and the vehicle 7, and then heads toward the vehicle 7 as the road surface layer reflected light L7 having the optical path RT7.

As shown in FIGS. 2A to 3B, the signal lamp 1 includes a light source 10 and a signal lamp unit 20. The light source 10 is held by the holding unit 30, for example, and emits light L1 toward the signal lamp unit 20. The light source 10 includes, for example, a first light source 10a that emits red light, a second light source 10b that emits yellow light, and a third light source 10c that emits blue light. The light source 10 may be a single light source, or may emit light displaying an arrow signal from the single light source. The light source 10 is, for example, an LED light source, an incandescent tungsten light bulb light source, or the like, and is, for example, circular or square when viewed from the direction (first direction Ax1) of the light L1 from the light source 10 along the optical path RT1. It has a quadrilateral.

The signal lamp unit 20 includes a polarizing unit 21. The polarizing unit 21 is provided on the optical path RT1 of the light L1 from the light source 10, receives the light L1 from the light source 10, and directs a part of the light L1 toward the vehicle 7 or the like on the road surface 6 of the road 5. And emit. The polarizing unit 21 is provided, for example, on the exit surface 11 of the light source 10. The polarizing unit 21 has a first surface 21a and a second surface 21b, and the first surface 21a is located on the opposite side of the second surface 21b. The first surface 21a and the second surface 21b are provided on the optical path RT1, and the first surface 21a is located closer to the light source 10 than the second surface 21b.

In FIG. 2A, the light source 10 includes three (plural) first light sources 10a, a second light source 10b, and a third light source 10c, and one signal lamp unit 20 includes three first light sources 10a and a second light source. It is provided so as to cover the light source 10b and the third light source 10c. For example, the signal lamp unit 20 is composed of three (plurality) units, each of which has a first light source 10a, a second light source 10b, and a third light source 10c. It may be provided on the exit surface 11 of the light source 10 so as to cover them individually. Seen from the first direction Ax1, the signal lamp unit 20 has a quadrilateral such as a circle, a square, and a rectangle.

The polarizing unit 21 has a transmission axis PL21 for transmitting vertically polarized light. The transmission axis PL21 transmits vertically polarized light, while blocking transmission of horizontally polarized light that intersects vertically polarized light. Therefore, of the light L1 emitted by the light source 10, the light having a vertically polarized component can pass through the polarizing unit 21. The vertically polarized light is, for example, P-polarized light, and the horizontally polarized light is, for example, S-polarized light.

As shown in FIG. 3 (b), the longitudinally polarized wave has a polarization plane in the direction of the first angle AG1 with the normal direction Nx1 of the road surface 6 of the road 5 when viewed from the first direction Ax1. .. The first angle AG1 is, for example, 0 degrees or more and less than 45 degrees. When the first angle AG1 has a value in this range, the reflectance of the light L1 from the signal lamp 1 on the road surface 6 is reduced. The first angle AG1 may be, for example, 0 degrees or more and less than 15 degrees. When the first angle AG1 has a value in this range, the reflectance of the light L1 from the signal lamp 1 on the road surface is further reduced.

The polarizing unit 21 can be a polarizing element such as an absorbing type polarizing element or a reflecting type polarizing element. Among the polarizers, the reflective polarizer can be a plate-like film composed of at least two polymer layers. In the reflective classifier, of the light incident in the reflective classifier, only the vertically polarized light along the transmission axis of the reflective classifier, for example, the P-polarized light, passes through the reflective classifier. On the other hand, light of laterally polarized light, for example, S-polarized light, which is substantially orthogonal to vertically polarized light, cannot pass through the reflective polarizer. The cross-polarized light (S-polarized light) that could not be transmitted is reflected and diffused / scattered again in the reflective polarizer and the light source. While repeating this diffusion and scattering, a part of the light reciprocating in the reflective polarizer can become vertically polarized (P-polarized) light along the transmission axis of the reflective polarizer and is reflected. Passes through the type polarizer. In the reflective polarizer, since the light is recycled in the reflective polarizer, the intensity of the light transmitted through the polarizing portion 21 can be increased.

The effective transmittance of the reflective polarizer is, for example, 1.0 to 2.0. When the effective transmittance of the reflective polarizer is in this range, the vertically polarized light emitted from the polarizing unit 21 can obtain high light intensity. The effective transmittance of the reflective polarizer is, for example, 1.3 to 1.7. When the effective transmittance of the reflective polarizer is in this range, the vertically polarized light emitted from the polarizing unit 21 can obtain a higher light intensity.

In the present embodiment, the effective transmittance of the reflective polarizer is as follows: spectrophotometer PR-650 (manufactured by Photoresearch), polarizing unit P / N 03FPG007 (manufactured by MellesGriot), 6.35 mm thick Teflon (registered trademark) diffusion. It can be measured using a light box directly under the plate and a light source device DCRIIw (manufactured by Fostec). In the polarizing unit P / N 03FPG007, for example, the single transmittance is 32% and the parallel Nicol transmittance is 20% or more. In the lamp EKE of the light source device DCRIIw, for example, the applied voltage is 21V and the electric power is 150W.

The effective transmittance is calculated as follows. That is, assuming that the emission spectrum of the light box is L _LB (λ) and the emission spectrum when the reflective polarizer is placed in the light box is L _sample (λ), the transmittance T _sample (λ) is expressed by the following equation ( Obtained in 1).
T _sample (λ) = L _sample (λ) / L _LB (λ)… (1)
_{Further, the emission spectrum L BL-sample} (λ) of the backlight when the reflective polarizer is placed in the light box is obtained by the following equation (2).
L _BL-sample (λ) = L _LB (λ) × T _sample (λ)… (2)

Further, when the correction term to the V (lambda), the backlight luminance B _sample when placed the reflective polarizer light box is determined by the following equation (3).
B _sample = ∫V (λ) ・ L _BL-sample (λ)… (3)
The backlight brightness _BBL is calculated by the following equation (4).
B _BL = ∫V (λ) ・ L _LB (λ)… (4)
From the above equations (3) and (4), the effective transmittance can be obtained from the following equation (5).
Effective transmittance = B _sample / B _BL ... (5)

At least one layer of the polymer layer contained in the reflective polarizer has, for example, naphthalate functionality. This naphthalate functionality is incorporated into the polymer layer by polymerizing one or more monomas containing the naphthalate functionality. Monomas containing naphthalate functionality include, for example, naphthalates such as 2,6-, 1,4-, 1,5-, 2,7-, 2,3-naphthalenedicarboxylic acids and esters thereof. Further, at least one of the polymer layers is, for example, polyethylene na, which is a copolyma of 2,6-, 1,4-, 1,5-, 2,7- and / or 2,3-naphthalenedicarboxylic acid and ethylene glycol. Includes phthalate (PEN). The thickness of the reflective polarizer is, for example, 20 to 100 μm.

FIG. 4 is a diagram showing the road surface layer reflectance of light from the signal lamp according to the embodiment. In this figure, the horizontal axis represents the incident angle TH1 of the light L1 from the signal lamp 1, and the vertical axis represents the reflectance (%) of the light L1. The reflectance is shown separately for the vertically polarized light (P-polarized light) and the horizontally polarized light (S-polarized light) of the light L1. It is shown that the road surface layer reflectance varies greatly depending on the polarization state of the light L1 from the signal lamp 1. In FIG. 4, the refractive index of the road surface 6 is 1.5.

As shown in FIG. 4, the vertically polarized light and the horizontally polarized light show substantially the same reflectance in the angle range where the incident angle TH1 is 0 to 15 degrees. When the incident angle TH1 is in the angle range of 15 degrees, the reflectance of laterally polarized light increases monotonically as the incident angle TH1 increases, and especially when the incident angle TH1 is around 60 degrees, it increases sharply. doing.

The reflectance of vertically polarized light decreases monotonically as the incident angle TH1 increases until the incident angle TH1 reaches 50 degrees. When the incident angle TH1 is in the angle range of 50 to 60 degrees, the reflectance of vertically polarized light shows a minimum value, and when the incident angle TH1 exceeds 60 degrees, it increases sharply. The reflectance of vertically polarized light is generally in the range of 5 (%) to 3 (%) when the incident angle TH1 is in the angle range of 10 to 30 degrees. When the incident angle TH1 is in the angle range of 30 degrees to 50 degrees, the value in the range of approximately 3 (%) to 0 (%) is shown. When the incident angle TH1 is in the angle range of 50 to 60 degrees, the reflectance of vertically polarized light is almost 0 (%), and the Brewster angle is in the angle range of 50 to 60 degrees. .. The results of FIG. 4 show that as the polarization state of the light L1 from the signal lamp 1, the road surface layer reflectance can be suppressed in the vertically polarized light rather than the horizontally polarized light.

In the present embodiment, the incident angle TH1 of the vertically polarized light on the road surface 6 may be in an angle range of 15 degrees to 60 degrees. When the incident angle is in this range, the road surface layer reflectance of the light L1 from the signal lamp 1 can be effectively suppressed. The angle of incidence TH1 on the vertically polarized road surface 6 may be in an angle range of 30 to 60 degrees. When the incident angle is in this range, the road surface layer reflectance of the light L1 from the signal lamp 1 can be suppressed more effectively. The angle of incidence TH1 on the vertically polarized road surface 6 may be in an angle range of 50 to 60 degrees. When the incident angle is in this range, the road surface layer reflectance of the light L1 from the signal lamp 1 can be further effectively suppressed.

FIG. 5A is a plan view of the signal lamp unit according to the embodiment, and FIG. 5B is a side view of the signal lamp unit according to the embodiment. The signal lamp unit 20 includes a polarizing unit 21 and further includes a transparent base material 22. The transparent base material 22 is provided on at least one of the first surface 21a and the second surface 21b of the polarizing portion 21. Therefore, in FIG. 5B, the transparent base material 22 is provided on both the first surface 21a and the second surface 21b of the polarizing portion 21, but the transparent base material 22 is the polarizing portion 21. It may be provided only on the first surface 21a, or may be provided only on the second surface 21b of the polarizing portion 21. By providing the transparent base material 22, the weather resistance of the signal lamp unit 20 and the signal lamp 1 is improved. In FIGS. 5A and 5B, a light source 10 is also drawn to show the positional relationship between the signal lamp unit 20 and the light source 10.

The transparent substrate 22 contains, for example, a low retardation material. According to the transparent base material 22 containing the low retardation material, the polarized state of the light L1 emitted from the second surface 21b of the polarizing portion 21 can be maintained. The in-plane retardation (Re) value of the low retardation material is, for example, 0 nm to 100 nm. When the in-plane Re value of the low retardation material is in this range, the polarized state of the light L1 emitted from the polarizing unit 21 is effectively maintained. The in-plane Re value of the low retardation material may be, for example, 0 nm to 50 nm. When the in-plane Re value of the low retardation material is in this range, the polarized state of the light L1 emitted from the polarizing unit 21 is maintained more effectively.

In the present embodiment, the in-plane Re value represents the magnitude of birefringence in the in-plane direction in the low retardation material, and is represented by a value at a wavelength of 587.8 nm. The in-plane Re value is expressed by the following equation (A) when the refractive index in the slow axis direction is Nx, the refractive index in the phase advance axis direction is Ny, and the thickness of the low retardation material is d in the in-plane direction. NS.
Re [nm] = (Nx-Ny) x d [nm] ... (A)

Specific examples of the low retardation material include acetyl cellulose resins such as triacetyl cellulose, polyurethane resins, acrylic resins, olefin resins such as polyethylene and polymethylpentene, polyethylene terephthalates, and polyethylene naphthalates. Examples thereof include resins such as polyester resins, cycloolefin polymers, and cycloolefin copolymers.

The signal lamp unit 20 may further include a viewing angle control unit 23. The viewing angle control unit 23 can control the spread of the light L1 from the signal lamp unit 20. The viewing angle control unit 23 can be provided on either the first surface 21a side or the second surface 21b side of the polarizing unit 21.

As shown in FIG. 5B, in the signal lamp unit 20, for example, the transparent base material 22, the polarizing unit 21, the transparent base material 22, and the viewing angle control unit 23 are arranged in this order from the light source 10. The light enters the signal lamp unit 20 from the viewing angle control unit 23. That is, the viewing angle control unit 23 can be provided between the light source 10 and the polarizing unit 21. In the signal lamp unit 20, for example, the transparent base material 22, the viewing angle control unit 23, the polarizing unit 21, and the transparent base material 22 are arranged in this order, and the light from the light source 10 is the first of the polarizing units 21. It is incident on the signal lamp unit 20 from the transparent base material 22 on the surface 21a side. That is, the viewing angle control unit 23 can be provided on the opposite side of the light source 10 with respect to the polarizing unit 21. In the signal lamp unit 20, for example, the viewing angle control unit 23, the transparent base material 22, the polarizing unit 21, and the transparent base material 22 may be arranged in this order.

When the viewing angle control unit 23 is provided between the light source 10 and the polarizing unit 21, the light L1 emitted from the viewing angle control unit 23 passes through the polarizing unit 21 to allow the viewing angle control unit 23 to view. Although the angle control performance may be deteriorated, the light L1 emitted from the polarizing unit 21 does not pass through the viewing angle control unit 23, so that the polarized state of the light L1 is easily maintained, and the light L1 from the light source 10 is easily maintained. The reflection intensity of the road surface layer is kept low. On the other hand, when the viewing angle control unit 23 is provided on the opposite side of the light source 10 with respect to the polarizing unit 21, the light L1 emitted from the polarizing unit 21 passes through the viewing angle control unit 23, so that the light L1 is transmitted. Although the polarization state of the light L1 may change, the light L1 emitted from the viewing angle control unit 23 does not pass through the polarization unit 21, so that the control performance of the viewing angle control is unlikely to deteriorate.

The polarizing unit 21 of the signal lamp 1 has a transmission axis PL21 for transmitting vertically polarized light. The vertically polarized light is light in the polarization direction that can reduce the intensity of the road surface layer reflected light L7 as compared with the horizontally polarized light. That is, in this signal lamp 1, among the light L1 from the light source 10, the amount of light emitted in the polarization direction that can reduce the intensity of the road surface layer reflected light L7 is more difficult to reduce the intensity of the road surface layer reflected light L7. The amount of light emitted in the polarization direction can be adjusted to be larger than the amount of light emitted, and the reflectance on the road surface 6 can be reduced. The signal lamp unit 20 can control the polarization state of the light L1 from the light source 10 by the polarizing unit 21, reduce the intensity of the road surface layer reflected light L7, and the transparent base material 22 can make the signal lamp unit 20 weather resistant. Improves sex.

FIG. 6A is a plan view showing the appearance of the viewing angle control unit of the signal lamp unit according to the embodiment, and FIG. 6B is along the VIb-VIb line of FIG. 6A. It is a cross-sectional view. The viewing angle control unit 23 includes a louver layer 24, and in the louver layer 24, for example, a light transmitting unit 25 and a light shielding unit 26 are alternately arranged. The light transmitting portion 25 and the light shielding portion 26 can be arranged along the arrangement direction Ex1 intersecting the first direction Ax1. The louver layer 24 is provided on, for example, the transparent substrate 27. In the louver layer 24, the translucent portion 25 and the transparent substrate 27 may be integrated. In the present embodiment, the light-shielding portion 26 can be provided in the plurality of grooves 28 formed by the translucent portion 25 and the transparent substrate 27. The light transmitting portion 25 and the transparent substrate 27 transmit the light L1 from the light source 10, and the light blocking portion 26 blocks the light L1 from the light source 10. As a result, the viewing angle control unit 23 controls the diffusion angle range of the light L1 from the light source 10 emitted along the first direction Ax1.

Specific examples of the materials of the translucent portion 25 and the transparent substrate 27 include acrylic resin, polyethylene teflate resin, polycarbonate resin, polybutylene tephthalate resin, nylon resin, propolyprene resin, and fluorine resin. Examples thereof include resins, polyolifin-based resins, cellulose-based resins, and silicon-based resins. Specific examples of the material of the light-shielding portion 26 include an absorption material such as carbon black and a resin material containing an amount of a reflective material such as alumina. The viewing angle control unit 23 may be made of metal and may have a metal louver layer 24. The signal lamp unit 20 may include a viewing angle control unit 23 made of metal.

In the present embodiment, when the material of the translucent portion 25 and the transparent substrate 27 is a resin such as the above-mentioned acrylic resin, the louver layer 24 has a thickness D24, and the thickness D24 is, for example, 50 to 500 μm. Is. The groove 28 has a groove width W28 and a groove depth D28, the groove width W28 is, for example, 1 to 50 μm, and the groove depth D28 is, for example, 50 to 500 μm. The light transmitting portion 25 has a light transmitting width W25, and the light transmitting width W25 is, for example, 20 to 1500 μm. In the configuration shown in FIG. 6B, the viewing angle control unit 23 has, for example, an angle range of diffusion control of 20 to 120 degrees.

In the signal lamp unit 20, each member can be adhered to each other. Examples of the adhesive material include solvent type, emulsion type, pressure sensitive type, heat sensitive type, thermosetting type and ultraviolet curable type such as general acrylic type, polyolefin type, polyurethane type, polyester type and rubber type. Adhesives can be included.

7 (a) and 7 (b) are schematic views showing the light from the signal lamp according to the embodiment and the vehicle on the road surface of the road. In both (a) and (b) of FIG. 7, the diffusion of the light L1 from the signal lamp 1 is controlled by the viewing angle control unit 23. In FIG. 7A, the control direction of the diffusion of the light L1 is along the normal direction Nx1 of the road surface 6 of the road 5, and in FIG. 7B, the diffusion of the light from the signal lamp is on the road. It is along a direction substantially orthogonal to the normal direction of the road surface. The arrangement direction Ex1 of the louver layer 24 in the viewing angle control unit 23 is along the normal direction Nx1 of the road surface 6 of the road 5 in FIG. 7A, and is from the signal lamp in FIG. 7B. The diffusion of light is along a direction that is approximately orthogonal to the normal direction of the road surface.

As shown in FIG. 7A, the diffusion of the light L1 from the signal lamp 1 is controlled along the normal direction Nx1 of the road surface 6 of the road 5, so that, for example, one toward the signal lamp 1. Of the two vehicles on the road, only the vehicle 7b behind can visually recognize the light L1 from the signal lamp 1. In FIG. 7A, the light L1 from the signal lamp 1 should be visually recognized only by the rear vehicle 7b, and the vehicle 7a in front should not visually recognize the light L1 from the signal lamp 1. Therefore, the vehicle 7a in front can safely travel without being confused by unnecessary traffic information from the signal lamp 1.

As shown in (b) of FIG. 7, since the diffusion of the light L1 from the signal lamp 1 is controlled along the direction substantially orthogonal to the normal direction Nx1 of the road surface 6 of the road 5, for example, they intersect each other. Of the two vehicles on the two roads merging with the road provided with the signal lamp 1, only one of the vehicles 00 can visually recognize the light L1 from the signal lamp 1. In FIG. 7B, only one vehicle 7c should be able to see the light L1 from the signal lamp 1, and both 7d of the other vehicle should not see the light L1 from the signal lamp 1. Therefore, both 7d of the other vehicle can safely travel without being confused by unnecessary traffic information from the signal lamp 1.

Since the signal lamp 1 further includes a viewing angle control unit 23 provided on the optical path RT 1, the vehicle on the road surface 6 of the road 5 can easily see only the necessary traffic information. Further, since the viewing angle control unit 23 may have the louver layer 24, the vehicle 7 on the road surface 6 of the road 5 can more easily see only the necessary traffic information.

Hereinafter, the signal lamp will be further described with reference to Examples and Comparative Examples of the present invention. The present invention is not limited to the following examples.

(Example 1)
FIG. 8A is a diagram showing a measurement system for the road surface layer reflectance of the signal lamp according to the first embodiment. The signal lamp 1p of this embodiment includes a light source 10p and a polarizing unit 21p, and the polarizing unit 21p is provided on the optical path RT1p of the light L1p from the light source 10p. In the measurement system MS1p of this embodiment, the light L1p from the light source 10p passes through the polarizing portion 21 and is incident on the reflection sheet 5p, and then is reflected by the reflection sheet 5p as a road surface. In this example, the reflected light L1p was measured by the detector 9p. The light incident on the reflective sheet 5p has almost only longitudinally polarized light, and the vertically polarized light is approximately between the surface 6p of the reflective sheet 5p and the normal direction Nx1p when viewed from the direction along the optical path RT1p. It had a plane of polarization in the direction perpendicular to it. In the detector 9p, the two-dimensional image and the brightness (cd / m ² ) of the reflected light RL1p on the reflective sheet 5p were measured. In this embodiment, almost all of the light L1p from the light source 10p is emitted toward the reflective sheet 5p.

A mini maglite LED AA (registered trademark, manufactured by A & F) was used as the light source 10, and the incident angle TH1p of the LED light on the reflecting sheet 5p was 30 degrees. For the reflective sheet 5p, 3M ^TM Standard Blackout Film with ^{Company TM} FRA 3045 J (registered trademark, manufactured by 3M Ltd.) was used. A two-dimensional color luminance meter CA-2000 (registered trademark, manufactured by Konica Minolta) was used as the detector 9p. As the polarizing portion 21p, a brightness increasing film DBEF-Qv2 (registered trademark, manufactured by 3M Co., Ltd.) was used. The Blackout Film as the reflective sheet 5p has a flat surface when viewed microscopically, and has a surface including irregularities when viewed macroscopically. The characteristics of this surface are similar to the characteristics of the road surface having a water layer, and the Blackout Film exhibits the same light reflection characteristics as the road surface of a road having a water layer. Therefore, the reflected light by the Blackout Film can be evaluated as being substantially the same as the road surface layer reflected light.

(Comparative Example 1)
FIG. 8B is a diagram showing a measurement system of the road surface layer reflectance of the signal lamp according to Comparative Example 1. The measurement system MS1q of this comparative example has the same configuration as that of the first embodiment except that the signal lamp 1p does not include the polarizing unit 21p. In this comparative example, the light L1q from the light source 10p was elliptically polarized. Also in this comparative example, the two-dimensional image and the brightness (cd / m ² ) of the reflected light RL1q on the reflective sheet 5p were measured by the detector 9p.

FIG. 9A is a diagram showing ^{the brightness (cd / m 2} ) of the reflected light RL1p in the first embodiment. FIG. 9B is a diagram showing ^{the brightness (cd / m 2} ) of the reflected light RL1q in Comparative Example 1.

From the results of (a) of FIG. 9 and (b) of FIG. 9, it was shown that the brightness of Example 1 and Comparative Example 1 were different from each other. It was shown that the reflected light intensity of Example 1 was smaller than the reflected light intensity of Comparative Example 1.

FIG. 10 is a diagram showing the results of luminance measurement in Example 1 and Comparative Example 1. The horizontal axis is the distance (mm) on the reflective sheet 5p from the exit surface 11p of the light source 10, and the vertical axis is the brightness (cd / m ² ). The results of FIG. 10 show that the value in Example 1 is smaller than the value in Comparative Example 1 with respect to the brightness in the region where the light L1p (light L1q) from the light source 10p is incident on the reflective sheet 5p. Was done. That is, it was shown that the signal lamp 1p provided with the polarizing portion 21p can reduce the reflection on the reflection sheet 5p.

1, 1p ... signal lamp, 5 ... road, 6 ... road surface, 10, 10p ... light source, 20 ... signal lamp unit, 21, 21p ... polarizing part, 21a ... first surface, 21b ... second surface, 22 ... transparent group Material, 23 ... Viewing angle control unit, Ax1 ... First direction, Ex1 ... Arrangement direction, Nx1 ... Normal direction, L1, L1p ... Light, PL21 ... Transmission axis, RT1, RT1p ... Optical path.

Claims (10)

Light source and
A polarizing part provided on the optical path of the light from the light source, and
With
The polarizing unit is a signal lamp having a transmission axis for transmitting vertically polarized light. The signal lamp according to claim 1, wherein the vertically polarized light has a plane of polarization in a direction of an angle of less than 45 degrees with the normal direction of the road surface when viewed from a direction along the optical path. The signal lamp according to claim 1 or 2, wherein the polarizing portion is a reflective polarizer. The signal lamp according to claim 3, wherein the effective transmittance of the reflective polarizer is 1.0 to 2.0. Further provided with a transparent base material provided on the optical path,
The transparent base material is provided on at least one of the first surface of the polarizing portion and the second surface opposite to the first surface.
The signal lamp according to any one of claims 1 to 4, wherein the first surface and the second surface are provided on the optical path. The signal lamp according to claim 5, wherein the transparent base material is a low retardation material. The signal lamp according to any one of claims 1 to 6, further comprising a viewing angle control unit provided on the optical path. The signal lamp according to claim 7, wherein the viewing angle control unit has louver layers in which light-transmitting parts and light-shielding parts are alternately arranged. A polarizing part for transmitting vertically polarized light and
A transparent base material provided on at least one of the first surface of the polarizing portion and the second surface opposite to the first surface,
With
The first surface and the second surface are signal lamp units provided on the optical path of the vertically polarized light. The signal lamp unit according to claim 9, wherein the polarizing unit is a reflective polarizer.

Images