Light emitting apparatus for vehicle

A light emitting apparatus for a vehicle includes a light source, a diffuser and a beam guider. The light source emits light having a beam pattern with a first imaginary line starting from a center of the beam pattern and extending to a perimeter of the beam pattern and a second imaginary line starting from the center of the beam pattern and extending to the perimeter of the beam pattern at a preset angle relative to the first imaginary line. The first and second imaginary lines have lengths different from each other. The diffuser receives the light of the light source and diffuses the received light to reduce the difference between the lengths of the first and second imaginary lines. The beam guider guides the diffused light along a path to produce an outlet light within a preset range.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority of Korean Patent Application Number 10-2015-0030930 filed on Mar. 5, 2015, the entire contents of which application are incorporated herein for all purposes by this reference.

BACKGROUND OF INVENTION

Field of Invention

The present disclosure relates to a light emitting apparatus for a vehicle. More particularly, it relates to a light emitting apparatus for a vehicle that diffuses the light from a light source and produces a more evenly or uniformly distributed light.

Background Art

Recently, a variety of researches and changes are made about the illumination apparatus for a vehicle. The changes are made not only about the exterior design of the lamp but also about the entire lamp including the interior reflector. These changes include the variations of the light emitting apparatus of the lamp, that is, according to a related art, a light generation method using a simple electric bulb is used, however, recently, light emitting apparatuses using a variety of light sources such as the laser, LED or the like are being developed. In case of the laser among these, since the high density energy can be generated so that there is an advantage of capable of irradiating a comparatively far distance, the development is more vigorously performed.

In general, in case of using only one laser, the amount of light is insufficient, so plural lasers are used and lights are superimposed. However, in this case, there occurs a collection of the light of the laser and thus there arises a problem in that the energy is not uniformly distributed.

Specifically describing this by referring toFIGS. 1A and 1Bwhich are views illustrating a conventional light emitting apparatus using a laser, whereFIG. 1Ais a view illustrating the energy distributions with each laser, andFIG. 1Bis a view illustrating a superimposed shape of lasers and an energy distribution thereof. Since the laser diode, due to the property of the laser, forms a beam pattern in a form of an elliptic shape in which the energy is concentrated more at the center and irradiates light when using three or plural laser diodes, the light is superimposed only on the center as shown inFIG. 1B. This means that the energy is collected on the center and is not uniformly distributed over an entire irradiation area of the beam pattern as shown in the graphs. If the energy is not uniformly distributed, then the inefficiency in using the energy is caused, and the degradation of the fluorescent body which changes the wavelength of the laser is accelerated, and further it even causes a problem of inducing the functional damage or destruction of the fluorescent body. Therefore, a light emitting apparatus is required in which a plurality of light sources form a superimposition of the beam patterns matching each other.

SUMMARY OF INVENTION

The present invention has been made in an effort to solve the above-described problems associated with prior art and/or other problems. One object of the present invention is to provide a light emitting apparatus for a vehicle which may accomplish a matching of the beam patterns even if the plural light sources are irradiated at various angles so that the beam patterns are superimposed.

In one aspect, a light emitting apparatus for vehicle according to the present invention comprises: a light source for emitting light having a beam pattern with a first imaginary line and a second imaginary line, wherein the first imaginary line starts from a center of the beam pattern and extends to a perimeter of the beam pattern, the second imaginary line starts from the center of the beam pattern and extends to the perimeter of the beam pattern at a preset angle relative to the first imaginary line, and the first and second imaginary lines have lengths different from each other; a diffuser for receiving the light of the light source and diffusing the received light to reduce the difference between the lengths of the first imaginary line and the second imaginary line; and a beam guider for guiding the diffused light along a path to produce an outlet light within a preset range.

In a preferred embodiment, the beam pattern may be formed such that the length of the second imaginary line is shorter than the length of the first imaginary line, and the diffuser may reduce the difference between the lengths of the second imaginary line and the first imaginary line by increasing the length of the second imaginary line.

In another preferred embodiment, the beam pattern may have a plurality of imaginary lines, and the first imaginary line may be the longest among the plurality of imaginary lines.

In still another preferred embodiment, the diffuser may diffuse the beam pattern so that the length of the second imaginary line becomes substantially the same as that of the first imaginary line.

In yet another preferred embodiment, the diffused light may have a beam pattern in a substantially circular shape with the first imaginary line as a radius.

In still yet another preferred embodiment, a conduit line may be formed in the beam guider, through which the light travels, and a reflector may be provided in the beam guider to reflect and guide the light incident into the conduit line.

In still yet another preferred embodiment, the beam guider may have a substantially cylindrical shape, and one end of the beam guider may face the diffuser.

In still yet another preferred embodiment, the light source may generate a laser beam, and a fluorescent body may be provided at an outlet of the beam guider for producing the outlet light at a wavelength different than a wavelength of the laser beam.

DETAILED DESCRIPTION

Hereafter, a light emitting apparatus for a vehicle according to some embodiments of the present invention will be described by referring to the accompanying drawings.

FIG. 2is a view illustrating a first imaginary line and a second imaginary line of a beam pattern according to some embodiments of the present invention.FIGS. 3 and 4are views illustrating a light emitting apparatus for a vehicle according to some embodiments of the present invention. The light emitting apparatus for a vehicle according to some embodiments of the present invention may include: a light source100for forming a beam pattern in such a way that when a first imaginary line A leading from a center of the beam pattern X to a perimeter of the beam pattern X and a second imaginary line B having a preset angle relative to the first imaginary line A are set, the imaginary lines A and B have lengths different from each other; a diffuser200for receiving light of the light source100and diffusing the received light so as to decrease the difference in the lengths of the first imaginary line A and the second imaginary line B; and a beam guider300for guiding a path of travel of the light to collect the diffused light within a preset range.

Specifically, the light source100may have a beam pattern shape of an irregular polygon or an elliptic shape, and preferably may have a beam pattern shape of an elliptic shape. Of course, the beam pattern shape is not necessarily limited to these shapes but may have a variety of shapes.

The first imaginary line A may have the largest length among plural imaginary lines which may lead from the center of the beam pattern X to the perimeter thereof, and the second imaginary line B may be formed to be shorter than the first imaginary line A, and the diffuser200may reduce the difference between the lengths of the second imaginary line B and the first imaginary line A by increasing the length of the second imaginary line B.

Herein, the second imaginary line B refers to a single imaginary line or a plurality of imaginary lines having lengths shorter than the first imaginary line A. By way of illustration,FIG. 2shows the second imaginary line B having one imaginary line. Through the diffuser200, the lengths of the second imaginary line B (e.g., at least one imaginary line or all imaginary lines in the plurality of imaginary lines having shorter lengths than the first imaginary line A) may be increased, reducing the difference between the lengths of the second imaginary line B and the length of the first imaginary line A. To this end, it is preferable that a plurality of diffusing patterns are formed at the diffuser200so as to be able to diffuse the light. For example, the diffuser200may be a diffusing lens or an optic and the like.

As a further preferable embodiment, the diffuser200may diffuse the beam pattern X so that the length of the second imaginary line B becomes the same or substantially the same as that of the first imaginary line A, and the diffused beam pattern X may be formed to have a circular shape having the first imaginary line A as a radius.

The diffusing pattern of the diffuser200may be set in a variety of forms such that the beam pattern X may have a circular shape, and the diffusing pattern at a place corresponding to the first imaginary line A may be formed to be different from those at remaining places. For example, since the first imaginary line A has to be prevented from diffusing and at least one of the second imaginary lines B has to be diffused to change the elliptic shape to the circular shape, the diffusing patterns different from each other may be formed according to each preset place.

By making a width of the beam pattern X be maximum length entirely and uniformly as described herein, the energy is not concentrated at a place but distributed uniformly in a preset range when compared to the beam pattern X having the circular shape or the irregular polygon shape.

FIG. 3is a view illustrating an exemplary light emitting apparatus of the present application viewed in the Θ∥ direction ofFIG. 2andFIG. 4is a view illustrating the exemplary light emitting apparatus of the present application viewed in the Θ⊥ direction ofFIG. 2. As shown, in some embodiments, a conduit or conduit line301is formed in the beam guider300, through which the light travels, and a reflector500is provided in the conduit line to guide the movement of the light L incident into the conduit line301. The beam guider300may be a pipe of a cylindrical or substantially cylindrical shape or a structural body formed with the conduit line301.

One end of the beam guider300is configured to face the diffuser200, so that light L of the light source which has passed the diffuser200may be output to the outside along the beam guider300. A width of the beam guider300is preferably formed to have a size corresponding to the maximum length of the beam pattern X before received by the diffuser200so that the light L generated at the light source100is entirely received, and the reflector500in the beam guider300may be installed partly along the length of the beam guider300or may be provided to cover all the wall of the conduit line301. A variety of embodiments, for example, a mirror or a reflecting coating may be applied to the installation of the reflector500.

Meanwhile, a variety of light sources may be used for the light source100, and preferably the laser diode may be used. Since if the laser is directly irradiated to the eyes of human being, there is a risk of causing blindness in view of the property of the laser, it is preferable to prevent damage to the eyes of human being by producing an outlet light at a wavelength different than a wavelength of the laser beam. Therefore, in some embodiments, a fluorescent body400may be provided at the outlet of the beam guider300to produce the outlet light at a wavelength different than a wavelength of the laser beam. The fluorescent body400may be configured to cover the entire outlet of the beam guider300to ensure the laser beam passing through the fluorescent body400and irradiated.

Of course, in a case where LED other than the laser diode or a light emitting source of other types is used for the light source100, the fluorescent body400is not a necessity and may be removed.

According to the present invention described herein,FIGS. 5 and 6are views illustrating an energy distribution of the light emitting apparatus for a vehicle according to some embodiments of the present invention.FIG. 5is a view illustrating an energy distribution viewed in the Θ∥ direction ofFIG. 2andFIG. 6is a view illustrating an energy distribution viewed in the Θ⊥ direction ofFIG. 2.FIGS. 5 and 6show the light energy distributions at various locations, where Y indicates the energy distribution of the finally output light.

The Θ⊥ direction ofFIG. 2is a direction viewing in such a way that the first imaginary line becomes the radius, and the Θ∥ direction ofFIG. 2is a direction viewing in such a way that the imaginary line having the minimum length among the imaginary lines becomes the radius. As can be seen inFIGS. 5 and 6, energy distributions at different locations are different from each other. The beam pattern X at the finally output is more evenly distributed. In particular, the light L of the light source incident into the conduit line301is reflected by the reflector500provided in the beam guider300such that the energy is uniformly output through the perimeter and the center of the outlet of the beam guider300as shown by Y, thus the energy is prevented from being concentrated only at the center and may be more evenly or uniformly distributed over the entire area of the outlet.

According to the light emitting apparatus for a vehicle of the present invention, the energy distributions of the finally output beam patterns become uniform (or more evenly distributed) to give the uniformly distributed energy distribution even when the beam patterns are superimposed.

Furthermore, according to the light emitting apparatus for a vehicle of the present invention, the excessive energy concentrating at a certain place may be prevented to prevent the deformation or damage to the center of the light receiving surface.

In addition, according to the light emitting apparatus for a vehicle of the present invention, a uniform color feeling may be kept by reducing the occurrence of the chromatic aberration according to the difference in the energy density of the center and the perimeter.

In addition, the occurrence of the chromatic aberration according to the difference in the energy density of the center and the perimeter may be reduced.