KR20160089628A - Lamp for vehicle - Google Patents

Abstract

According to an embodiment of the present invention, a lamp for a vehicle comprises: a light source; a polarizing part which reflects a first polarized beam having a first direction emitted from the light source, transmitting a second polarized beam having a second direction vertical to the first direction; a wavelength converting part which converts a wavelength of the first polarized beam reflected from the polarizing part; and a reflecting part which reflects the light emitted from the light source or the light having a wavelength converted in the wavelength converting part. As such, the present invention contributes to safe driving, and minimizes a decrease in light output efficiency.

Description

Lamp for vehicle

An embodiment relates to a lamp for an automobile.

Semiconductor light emitting diodes (LEDs) are a kind of semiconductor devices that convert the electricity to infrared rays or light using the characteristics of compound semiconductors, exchange signals, or use as a light source.

III-V nitride semiconductors (group III-V nitride semiconductors) are attracting attention as a core material for light emitting devices such as light emitting diodes (LEDs) and laser diodes (LDs) due to their physical and chemical properties.

These light emitting diodes and laser diodes are environmentally friendly because they do not contain environmentally harmful substances such as mercury (Hg) used in existing lighting devices such as incandescent lamps and fluorescent lamps, and have advantages such as long lifetime and low power consumption characteristics Replacing existing light sources.

Further, the light emitting device can be applied to various fields. Particularly, such a light emitting device has been widely applied to a variety of fields such as a headlight for a car (or a headlight) and a flashlight. As described above, the light emitting device including the light emitting element is required to have excellent light extraction efficiency, and the demand for the downsizing, light weight, and low manufacturing cost is continuously increasing.

When a conventional automobile lamp having a light emitting element is used, when a water film is formed on a road surface on which an automobile is running, light emitted from the lamp may cause total reflection in the water film, so that the lane mark on the road surface may appear blurry to the driver, . ≪ / RTI >

The embodiment provides an automotive lamp that can clearly show a lane indicator to a driver in an environment in which a water film is formed on a road surface.

An automotive lamp according to an embodiment includes: a light source; A polarizing unit that reflects a first polarized beam in a first direction and transmits a second polarized beam in a second direction perpendicular to the first direction, out of the light emitted from the light source; A wavelength converter for converting a wavelength of the first polarized light beam reflected by the polarizer; And a reflector for reflecting the light emitted from the light source or the wavelength-converted light by the wavelength converter.

For example, the polarizing portion may include a polarizing beam splitter that reflects the first polarized beam and transmits the second polarized beam. Also, for example, the polarizing portion may include a Dual Brightness Enhancement Film (DBEF) that reflects the first polarized beam and transmits the second polarized beam.

The wavelength converter may include a half wave plate (HWP) for modifying the wavelength of the first polarized beam by? / 2.

The first polarized beam may correspond to an S wave and the second polarized beam may correspond to a P wave.

The light transmitted through the polarizing portion can be emitted to the front of the automobile.

The polarization unit and the wavelength conversion unit may be disposed in contact with each other.

The automotive lamp according to the embodiment emits a polarized beam as a headlight so that total reflection does not occur in the water film when the road surface is covered with a water film, thereby helping the driver to clearly identify the lane and contributing to safe driving And the reduction of the light output efficiency can be minimized.

1 is a sectional view of an automotive lamp according to an embodiment.
2 is a cross-sectional view of a vehicle lamp according to a comparative example.
3 is a view for explaining reflection of light emitted from a headlamp for an automobile.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to facilitate understanding of the present invention. However, the embodiments according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. Embodiments of the invention are provided to more fully describe the present invention to those skilled in the art.

1 is a sectional view of an automotive lamp 100 according to an embodiment.

The lamp 100 for an automobile according to the embodiment shown in FIG. 1 may include a light source 110, a polarization unit 120, a wavelength conversion unit 130, and a reflection unit 140.

The light source 110 emits excitation light and may include at least one of a light emitting diode (LED) or a laser diode (LD) Lt; / RTI >

In the case of FIG. 1, the light source 110 is illustrated as being disposed inside the reflecting portion 140 in contact with the reflecting surface 144 of the reflecting portion 140, but the embodiment is not limited thereto. That is, according to another embodiment, although not shown, a through hole is formed through the reflection part 140, and the light source 110 is formed on the outer side of the reflection part 140, not on the inside of the reflection part 140 . In this case, the light emitted from the light source 110 can enter the inside of the reflecting portion 140 through the through hole.

1, the light source 110 may be disposed inside the reflection unit 140, and may be fixedly disposed in various forms. The embodiments are not limited to the attachment and coupling of the light source 110 .

The polarization unit 120 may reflect the first polarized beam in the first direction from the light emitted from the light source 110 toward the wavelength conversion unit 130. In addition, the polarizer 120 may transmit a second polarized beam in a second direction perpendicular to the first direction in the light emitted from the light source 110. In this way, the polarization unit 120 can perform the polarization splitting function.

Here, the first polarized beam may correspond to a S wave and the second polarized beam may correspond to a P wave. That is, the polarization unit 120 can transmit the P wave and reflect the S wave. That is, the polarizing section 120 can transmit the second polarized beam that is 0 ° polarized light of the light output from the light source 110, and can reflect the 90 ° polarized first polarized light beam.

According to one embodiment, the polarization unit 120 may be implemented with a polarizing beam splitter (PBS). The polarizing beam splitter can reflect the first polarized beam and transmit the second polarized beam. To this end, the polarizing beam splitter can be formed in the form of a plurality of coating layers by repeatedly depositing two or more kinds of materials having different refractive indexes on the adhesion surface of the triangular prism. The polarization beam splitter can be implemented to reflect S waves having a wavelength band of about 400 nm to 700 nm, but the embodiments are not limited thereto. In addition, the polarizing beam splitter may be embodied as multilayer polarizing films, but embodiments are not limited thereto.

According to another embodiment, the polarization unit 120 may be implemented with Dual Brightness Enhancement Film (DBEF). The DBEF may reflect the first polarized beam and transmit the second polarized beam in the light emitted from the light source 110. DBEF is manufactured in 3M and can be utilized as an LCD backlight. Since the DBEF itself is a known technology, a detailed description of the DBEF itself is omitted here.

Meanwhile, the wavelength converting unit 130 may convert the wavelength of the first polarized light beam reflected by the polarizing unit 120. For this purpose, for example, the wavelength converter 130 may be implemented as a half wave plate (HWP). The half wave plate can deform the wavelength of the first polarized light beam reflected by the polarization unit 120 by, for example,? / 2 (where? Represents a wavelength).

The reflection unit 140 may reflect the light emitted from the light source 110 or the wavelength-converted light from the wavelength conversion unit 130. To this end, for example, the reflector 140 may include a body 142 and a reflective surface 144. Here, the body 142 may serve to support the reflecting surface 144 or may support the entire lamp 100 for an automobile.

The inner reflective surface 144 of the body 142 reflects the light emitted from the light source 110 so that the reflected light (denoted by the solid line) can travel toward the polarization section 120. The reflection surface 144 reflects the wavelength-converted light in the wavelength conversion unit 130 so that the reflected light (indicated by a dotted line) can travel toward the polarization unit 120.

To this end, the reflective surface 144 may have a parabolic cross-sectional shape, but the embodiment is not limited to the cross-sectional shape of the reflective surface 144. If the reflective surface 144 has a parabolical cross-sectional shape, the light source 110 may be positioned close to the focal point of the parabolic reflective surface 144.

In addition, the reflection unit 140 may function not only to reflect light but also to collimate light into a beam.

The vehicle lamp 100 illustrated in FIG. 1 described above may be in a sealed form or an unsealed form.

The body 142 of the reflector 140 is disposed in contact with the wavelength converter 130 and the polarizer 120 and the wavelength converter 130 are in contact with each other . Thus, the space S surrounded by the reflective portion 140 and the wavelength conversion portion 130 can be sealed. That is, the polarization unit 120 and the wavelength conversion unit 130 may be disposed to cover the light source 110 and the reflection unit 140 in a tight manner.

Alternatively, when the lamp 100 is not sealed, the body 142 of the reflector 140 may be spaced apart from the wavelength converter 130, unlike that illustrated in FIG. Thus, the space S surrounded by the reflecting portion 140 and the wavelength converting portion 130 may take a non-sealed form.

1, a second polarized beam (denoted by a solid line) from the light emitted from the light source 110 is transmitted through the polarizing section 120, as shown in FIG. 1, according to the automotive lamp 100 according to the above- And is emitted to the outside of the automotive lamp (100). However, since the first polarized beam (denoted by a dotted line) in the light emitted from the light source 110 is reflected by the polarization unit 120 without passing through the polarization unit 120, And is returned to the reflection unit 140. [ In this way, the first polarized beam that has not transmitted through the polarization unit 120 is wavelength-converted by the wavelength conversion unit 130, reflected by the reflection unit 140, transmitted again through the polarization unit 120, . Thereby, the reduction of the light output efficiency can be minimized.

The polarization unit 120 described above may be replaced by DBEF, but the embodiment is not limited thereto. That is, according to another embodiment, the DBEF may replace the role of the polarization unit 120 and the wavelength conversion unit 130 shown in FIG.

The automotive lamp 100 shown in FIG. 1 can be used in various forms such as a head lamp, a tail lamp, a warning lamp, a car width, etc. of an automobile. If the automotive lamp 100 shown in Fig. 1 is used as a headlamp of an automobile, the second polarized beam transmitted through the polarizing portion 120 can be emitted to the front of the automobile.

Hereinafter, an automotive lamp 100 according to the above-described embodiment and a vehicle lamp according to a comparative example will be described with reference to the accompanying drawings.

2 is a cross-sectional view of a vehicle lamp according to a comparative example.

The automotive lamp according to the comparative example shown in FIG. 2 may be constituted by the light source 10, the reflecting portion 40, and the lens (or the transparent medium) 50. The light source 10 and the reflection unit 40 may perform the same functions as the light source 110 and the reflection unit 140 shown in FIG.

Unlike the automotive lamp 100 according to the embodiment shown in FIG. 1, the automotive lamp according to the comparative example shown in FIG. 2 includes a lens 50 instead of the wavelength converting unit 130 and the polarizing unit 120 . In the case of a vehicle lamp according to a comparative example having such a configuration, the light emitted from the light source 110 may be reflected by the reflection unit 40 and then emitted through the lens 50.

3 is a view for explaining the reflection of light emitted from the head lamp 210 for the automobile 200. Fig.

Referring to FIG. 3, when the automotive headlamp 210 is implemented as illustrated in FIG. 2, the light from the headlamp 210 secures the driver's viewing angle at night or in a dark environment.

2, when the road surface 310 is wet by the rainwater 320 or the like, that is, when the water film 320 is formed on the road surface 310 The light L1 emitted from the automotive headlamp 210 can be totally reflected by the water film 320 in the arrow directions L21, L22 and L23. Such total reflected light can make it difficult for the driver to identify the lane drawn on the road surface 310. [ That is, when the light is totally reflected by the water film 320 formed on the road surface 310, the lane drawn on the road surface 310 may appear blurred to the driver.

On the other hand, when the automotive headlamp 210 is implemented as illustrated in FIG. 1, the automotive lamp 210 emits only the polarized second polarized beam, so that the total reflection from the water film 320 on the road surface 310, The lanes L21, L22, and L23 do not occur, which helps the driver to easily identify the lane even in a situation where the road surface 310 is covered by the water film 320, thereby contributing to safe driving.

2, instead of disposing the transparent lens 50, the polarization unit 120 and the wavelength conversion unit 130 are disposed on a path through which light is emitted as shown in FIG. 1 , The light output efficiency may be reduced by 50%. In order to solve this problem, the automotive lamp 100 adopts a polarization beam splitter as the polarization unit 120 and a DBEF as the wavelength conversion unit 130 to minimize the decrease in the light output efficiency have.

Even in the case where the water film 320 is not formed on the road surface 310, the automotive lamp 100 according to the embodiment has the same light intensity as that emitted when the automobile lamp shown in Fig. 2 emits light at night It can be directed toward the direction of the automobile.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

100: Automotive lamp 110: Light source
120: polarization section 130: wavelength conversion section
140: reflector 142: body
144: Reflective surface 200: Automobile
210: Automotive headlamp 310: Road surface
320:

Claims (7)

In an automotive lamp,
Light source;
A polarizing unit that reflects a first polarized beam in a first direction and transmits a second polarized beam in a second direction perpendicular to the first direction, out of the light emitted from the light source;
A wavelength converter for converting a wavelength of the first polarized light beam reflected by the polarizer; And
And a reflector for reflecting the light emitted from the light source or the wavelength-converted light by the wavelength converting unit. 2. The lamp of claim 1, wherein the polarizing portion includes a polarizing beam splitter that reflects the first polarized beam and transmits the second polarized beam. 2. The lamp of claim 1, wherein the polarizing portion includes a Dual Brightness Enhancement Film (DBEF) that reflects the first polarized beam and transmits the second polarized beam. The apparatus of claim 1, wherein the wavelength converter
And a half wave plate (HWP) for modifying the wavelength of the first polarized beam by? / 2. The lamp of claim 1, wherein the first polarized beam corresponds to an S wave and the second polarized beam corresponds to a P wave. The lamp according to claim 1, wherein the light transmitted through the polarizing portion is emitted to the front of the automobile. The lamp of claim 1, wherein the polarizing portion and the wavelength converting portion are disposed in contact with each other.

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