KR102470449B1 - Lamp for vehicle - Google Patents

Abstract

The present invention relates to a lamp for a vehicle, and more particularly, to a lamp for a vehicle capable of preventing deterioration in light efficiency while forming a slim lamp image.
A vehicle lamp according to an embodiment of the present invention includes a light source unit and a light transmission unit for transmitting light generated from the light source unit to form a light irradiation area for forming a predetermined beam pattern, wherein the light transmission unit includes: A first lens unit located in front of the light source unit, and a second lens unit having a smaller diameter than the first lens unit and located in front of the first lens unit, wherein the first lens unit and the second lens unit, They have different refractive powers.

Description

Lamp for vehicle {Lamp for vehicle}

The present invention relates to a lamp for a vehicle, and more particularly, to a lamp for a vehicle capable of preventing deterioration in light efficiency while forming a slim lamp image.

In general, a vehicle is provided with various lamps having a lighting function for easily identifying an object located around the vehicle during night driving and a signal function for informing surrounding vehicles or pedestrians of the driving state of the vehicle, and each lamp sufficiently performs each function. Its installation standards and specifications are stipulated in the laws and regulations.

For example, head lamps and fog lamps are mainly intended for lighting functions, and turn signal lamps, tail lamps, and brake lamps are mainly used for signaling functions.

The vehicle lamp includes a light source and a lens that allows light generated from the light source to be externally radiated to form a beam pattern suitable for the function of the vehicle lamp, and a lamp image is formed by the light externally irradiated through the lens.

The light generated from the light source has a predetermined light emitting range based on the optical axis of the light source, and the lens is designed to have a diameter sufficient to allow the light generated from the light source to be incident without loss as much as possible according to the light emitting range of the light source. .

Such vehicle lamps have been merely means for performing lighting and signal functions, but in recent years, the proportion occupied by lamps in terms of design is increasing day by day.

In other words, not only the functional aspect that helps safe driving by enabling the driver's visibility, which is the basic role of vehicle lamps, but also the aesthetic aspect that consumers feel through design improvement has a great influence on whether or not to purchase a vehicle.

To this end, research is being actively conducted to improve the exterior design of vehicle lamps to form a slimmer lamp image, but when the diameter of the lens is reduced to form a slim lamp image, the lens Since light loss occurs due to light that cannot be incident, there is a possibility that light efficiency is lowered.

Therefore, there is a need for a method capable of preventing light efficiency from deteriorating while forming a slim lamp image.

Publication No. 10-2015-0052638 (published on May 14, 2015)

An object to be solved by the present invention is to provide a vehicle lamp capable of forming a slim lamp image while reducing loss of light generated from a light source by using a plurality of lenses having different refractive powers.

The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, a vehicle lamp according to an embodiment of the present invention includes a light source unit and a light transmission unit for transmitting light generated from the light source unit to form a light irradiation area for forming a predetermined beam pattern, The light transmission unit includes a first lens unit positioned in front of the light source unit and a second lens unit having a smaller diameter than the first lens unit and located in front of the first lens unit, wherein the first lens unit and The second lens unit has different refractive powers.

Other specific details of the invention are included in the detailed description and drawings.

According to the vehicle lamp of the present invention as described above, there are one or more of the following effects.

It is possible to form a slim lamp image while preventing light efficiency from deteriorating by using a plurality of lenses having different refractive powers, so that the exterior design can be improved.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 and 2 are perspective views showing a vehicle lamp according to an embodiment of the present invention.
Figure 3 is a side view showing a vehicle lamp according to an embodiment of the present invention.
Figure 4 is a cross-sectional view showing a lamp for a vehicle according to an embodiment of the present invention.
5 is a schematic diagram showing a light emitting range of a light source unit according to an embodiment of the present invention.
6 is a schematic diagram illustrating a back focal length of a first lens unit according to an embodiment of the present invention;
7 is a schematic diagram illustrating a vehicle lamp provided to a vehicle body according to an embodiment of the present invention.
8 is a schematic diagram showing an effective focal length of a vehicle lamp according to an embodiment of the present invention.
Figure 9 is a schematic diagram showing the size of the light emitting area of the light source unit according to an embodiment of the present invention.
10 is a schematic diagram showing a light path of a vehicle lamp according to an embodiment of the present invention.
11 is a schematic diagram showing a light irradiation range of a light irradiation area according to an embodiment of the present invention;
12 is a schematic diagram showing a beam pattern formed by a vehicle lamp according to an embodiment of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

Thus, in some embodiments, well-known process steps, well-known structures and well-known techniques have not been described in detail in order to avoid obscuring the interpretation of the present invention.

Terminology used herein is for describing the embodiments and is not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. As used herein, "comprises" and/or "comprising" refers to the presence or addition of one or more other elements, steps, operations and/or elements other than the mentioned elements, steps, operations and/or elements. It is used in the sense of not excluding. And "and/or" includes each and every combination of one or more of the recited items.

In addition, the embodiments described in this specification will be described with reference to cross-sectional views and/or schematic views, which are ideal exemplary views of the present invention. Accordingly, the shape of the illustrative drawings may be modified due to manufacturing techniques and/or tolerances. Therefore, embodiments of the present invention are not limited to the specific shapes shown, but also include changes in shapes generated according to manufacturing processes. In addition, in each drawing shown in the present invention, each component may be shown somewhat enlarged or reduced in consideration of convenience of explanation. Like reference numbers designate like elements throughout the specification.

Hereinafter, the present invention will be described with reference to drawings for explaining a vehicle lamp according to embodiments of the present invention.

1 and 2 are perspective views showing a vehicle lamp according to an embodiment of the present invention, Figure 3 is a side view showing a vehicle lamp according to an embodiment of the present invention, Figure 4 is a vehicle lamp according to an embodiment of the present invention A cross-sectional view of the lamp.

Referring to FIGS. 1 to 4 , a vehicle lamp 1 according to an embodiment of the present invention may include a light source unit 100 and a light transmission unit 200 .

The vehicle lamp 1 of the present invention can be used for various lamps installed in vehicles such as head lamps, tail lamps, brake lamps, fog lamps, daytime running lamps, turn signal lamps, and backup lamps.

The light source unit 100 may include at least one light emitting device generating light having an amount or color suitable for the purpose of the vehicle lamp 1 of the present invention, and in an embodiment of the present invention, at least one light emitting device is an LED. A case in which a semiconductor light emitting device such as a light emitting diode (LD) or a laser diode (LD) is used will be described as an example.

The light source unit 100 may generate light through a light emitting area of a predetermined size, and the light emitting area of the light source unit 100 may be an area corresponding to a light emitting surface of at least one light emitting element, or generated from at least one light emitting element. When the reflected light is emitted through a lens or a light guide, it may be an area corresponding to a surface on which light is emitted from the lens or the light guide.

The light transmission unit 200 may serve to transmit light generated from the light source unit 100 to form a light irradiation area for forming a beam pattern suitable for the use of the vehicle lamp 1 of the present invention.

The light transmission unit 200 may include a first lens unit 210 and a second lens unit 220, and the center of the first lens unit 210 and the second lens unit 220 is the light transmission unit 200. may be located on the optical axis Ax1 of

The first lens unit 210 is located in front of the light source unit 100 so that light generated from the light source unit 100 can be incident, and the second lens unit 220 is located in front of the first lens unit 210. Thus, light emitted from the first lens unit 210 may be incident.

In the embodiment of the present invention, the fact that the first lens unit 210 is located in front of the light source unit 100 and the second lens unit 220 is located in front of the first lens unit 210 means that the vehicle lamp of the present invention ( 1) means a position when the direction in which light is irradiated is assumed to be forward, and the direction actually meant by front may vary depending on the location or direction in which the vehicle lamp 1 of the present invention is installed.

The first lens unit 210 may include a first incident surface 211 through which light is incident from the light source unit 100 and a first exit surface 212 through which light incident to the first incident surface 211 is emitted. have.

In the embodiment of the present invention, the first incident surface 211 has a curvature whose center of curvature is located in front of the first incident surface 211 so that the first lens unit 210 has a positive refractive power. The exit surface 212 may have a curvature in which a center of curvature is located behind the first exit surface 212 .

That is, in the first lens unit 210, the first incident surface 211 has a convex shape with respect to the light source unit 100, and the first exit surface 212 has a convex shape with respect to the second lens unit 220. It may serve to converge the light generated from the light source unit 100 to the second lens unit 220.

In the embodiment of the present invention, the case where both the first incident surface 211 and the second exit surface 212 of the first lens unit 210 have curvature is described as an example, but this is the first incident surface 211 ) is intended to sufficiently refract the incident light, but is not limited thereto, and sufficient refraction occurs even when either one of the first incident surface 211 and the first emitting surface 212 is formed to have a curvature. If made, the other may have a planar shape.

The second lens unit 220 includes a second incident surface 221 into which light emitted from the first lens unit 210 is incident and a second exit surface 222 into which light incident to the second incident surface 221 is emitted. ) may be included.

In the embodiment of the present invention, the second incident surface 221 has a curvature such that the center of curvature is located behind the second incident surface 221 so that the second lens unit 220 has negative refractive power. The exit surface 221 may have a planar shape or have a curvature center of curvature located behind the second exit surface 221 .

That is, in the second lens unit 220, the second incident surface 221 has a concave shape with respect to the first lens unit 210, and the second exit surface 222 has a flat shape or a second exit surface 222. It is formed to have a convex shape with respect to the front of the lens unit 210 and can serve to diffuse light incident from the first lens unit 210 .

In this case, the curvature of the second incident surface 221 of the second lens unit 220 may be greater than that of the second exit surface 222 so as to have negative refractive power.

Meanwhile, the diameter d1 of the first lens unit 210 may be larger than the diameter d2 of the second lens unit 220, which means that the light generated from the light source unit 100 is not lost in the first lens unit. To enter the second lens unit 220 through 210 and at the same time to make the lamp image formed by the light emitted from the vehicle lamp 1 of the present invention have a slimmer shape when viewed from the outside of the vehicle It is for

That is, the light source unit 100 may generate light in a predetermined light emission range u in one direction centered on the optical axis Ax2 as shown in FIG. 5, and the light source unit 100 It is possible to estimate the focal length after the first lens unit 210 for the light generated from the first lens unit 210 to be incident to the light transmission unit 200, that is, the first lens unit 210 without loss, and the light emission of the light source unit 100 From the range u and the back focal length of the first lens unit 210, it is possible to estimate the diameter of the first lens unit 210 to have an appropriate light efficiency.

The rear focal length of the first lens unit 210 is the distance from the end of the first incident surface 211 of the first lens unit 210 to the focal point F where the light source unit 100 is located, as shown in FIG. It can be obtained by Equation 1 of

[Equation 1]

In Equation 1, BFL is generated with the back focal length of the first lens unit 210, u is the light emitting range of the light source unit 100, and h is the light emitting range u at the center of the light emitting area of the light source unit 100. It means the distance from the center of the first lens unit 210 to the edge of the light incident area in the light incident area where light is incident.

At this time, in the embodiment of the present invention, the case where the light emitting range (u) of the light source unit 100 is provided in advance through a manufacturer or an experiment will be described as an example, and from the light emitting range (u) of the light source unit 100 It is possible to estimate the diameter of the first lens unit 210 to have an appropriate light efficiency by estimating the post focal length.

The diameter d1 of the first lens unit 210 may be estimated to be greater than or equal to 2h, and when the diameter d1 of the first lens unit 210 is greater than or equal to 2h, the light generated from the light source unit 100 is transmitted to the first lens unit 210 without loss. Conversely, when the diameter d1 of the first lens unit 210 is less than 2h, some of the light generated from the light source unit 100 is transmitted to the first lens unit 210. It is not incident, and light loss occurs.

In this way, there is a limit to reducing the diameter d1 of the first lens unit 210 to have an appropriate light efficiency according to the back focal length of the first lens unit 210 and the light emitting range u of the light source unit 100. Therefore, it is difficult to form a slim lamp image with only the first lens unit 210 and have appropriate light efficiency.

Therefore, in the embodiment of the present invention, the first lens unit 210 is formed to have a positive refractive power, and the diameter d1 of the first lens unit 210 is smaller than the diameter d1 of the first lens unit 210 in front of the first lens unit 210. By positioning the second lens unit 220 having a diameter d2 and negative refractive power, the light passing through the light transmission unit 200 has an appropriate light efficiency and a slimmer lamp image is formed. do.

In other words, the light emitted from the vehicle lamp 1 of the present invention may be understood as light emitted through the second exit surface 222 of the second lens unit 220, and in this case, as shown in FIG. 7, the second Since the remaining components except for the lens unit 220 are covered by the vehicle body 300, they are prevented from being visually confirmed, so that the vehicle lamp 1 of the present invention can have a slimmer appearance, and the first lens unit Light generated from the light source unit 100 by 210 is incident to the second lens unit 220 without loss, thereby preventing light efficiency from deteriorating.

Meanwhile, the light transmission unit 200 may have an effective focal length according to the refractive powers of the first lens unit 210 and the second lens unit 220, and the effective focal length of the light transmission unit 200 is equal to the light transmission unit 200. It may be defined as the distance between the focal point F and the main plane, which is an imaginary plane located at the point where the extension line of incident light and the extension line of light emitted from the light transmission unit 200 meet.

In the embodiment of the present invention, the light incident on the first incident surface 211 of the first lens unit 210 passes through the first lens unit 210 and the second lens unit 220, and the second lens unit 220 Since it is emitted to the second exit surface 222 of ), the main surface is an extension line of light incident on the first incident surface 211 of the first lens unit 210 and an extension line of light exiting the second lens unit 220. It can be located at the meeting point.

At this time, the second lens unit 220 having a negative refractive power is positioned in front of the first lens unit 210 having a positive refractive power, and the second lens unit 220 is smaller than the diameter d1 of the first lens unit 210. When the diameter d2 of the lens unit 220 is made small, the main surface is formed between the light source unit 100 and the first lens unit 210, and the main surface is formed between the light source unit 100 and the first lens unit 210 compared to the case of using a single lens. ) can be formed close to

That is, when the light emitting range u of the light source unit 100 is the same, the case where a single aspheric lens is used as the light transmitting unit 200 as shown in FIG. 8 (a) and the light transmitting unit ( 200), it can be seen that the back focal length when the aforementioned first lens unit 210 and second lens unit 220 are used is the same.

At this time, when a single aspherical lens is used as the light transmission part 200 as shown in (a) of FIG. 8, the main surface where the extension line of light incident to the incident surface 200a and the extension line of light emitted to the exit surface 200b meet. When the first lens unit 210 and the second lens unit 220 described above are used as the light transmission unit 200 as shown in FIG. (100), so that the effective focal length f is shortened.

The effective focal length of the light transmission unit 200 may be defined by the size of the focal point F and the light emitting area of the light source unit 100 and a light irradiation range in which light transmitted through the light transmission unit 200 is irradiated.

As shown in FIG. 9 , the size of the light emitting area of the light source unit 100 may be defined as the longest distance y among the distances from the center C of the light emitting area to the edge of the light emitting area. In the case of a rectangular shape, the distance from the center C of the light emitting area to the vertex A may be defined as the size of the light emitting area.

At this time, defining the size of the light emitting area as the longest distance (y) of the distances from the center (C) of the light emitting area to the edge of the light emitting area is generated from the point having the longest distance from the center (C) of the light emitting area. This is to enable control of light.

As shown in FIG. 10, the light irradiation range is the light traveling from the center (C) of the light emitting area through the first lens unit 210 and the second lens unit 220, and the center (C) of the light emitting area among the edges of the light emitting area. It can be understood as a light irradiation angle range (θ) between light traveling from the point A having the longest distance (y) from the first lens unit 210 and the second lens unit 220 .

In addition, the above-described light irradiation angle range θ is the center of the light irradiation area R among the entire area of the light irradiation area R formed by irradiation of light by the vehicle lamp 1 of the present invention, as shown in FIG. As a range from to the edge of the light irradiation area R in a predetermined direction, the light irradiation angle range in the predetermined direction for the entire light irradiation area R may be understood as 2θ.

The effective focal length of the light transmission unit 200 is the distance between the focal point F where the light source unit 100 is located and the main surface, and can be obtained by Equation 2 below.

[Equation 2]

In Equation 2, f is the effective focal length of the light transmission unit 200, y is the size of the light emitting area, and θ is the light irradiation range. When the size of the light emitting area y is fixed, the effective focal length becomes shorter. The more the light irradiation range increases.

That is, as the effective focal length of the light transmitting part 200 is shortened, the light irradiation range in which the light passing through the light transmitting part 200 is irradiated widens, so that the diffusion characteristics of light are improved, so that the lamp image has a slimmer shape. can be formed, but a larger diffusion effect is obtained.

Looking at beam patterns when the light transmission unit 200 includes a single aspherical lens and when the light transmission unit 200 includes the above-described first lens unit 210 and second lens unit 220, FIG. 12 Compared to the case where the light transmission part 200 includes a single aspheric lens as shown in (a) of, the light transmission part 200 includes the above-described first lens unit 210 and the second lens unit as shown in FIG. 12 (b). In the case of including 220, it can be seen that the effective focal length is relatively shortened, so that the area to which light is irradiated is relatively widened.

As such, when the vehicle lamp 1 of the present invention is viewed from the outside of the vehicle, the area where the light is emitted is the second exit surface 222 of the second lens unit 220 and has a relatively slim shape, so it is slim. It is advantageous to the optical system for spread because it can form a lamp image and has superior light diffusion characteristics, and the light generated from the light source unit 100 is transferred to the second lens unit 220 without loss by the first lens unit 210. It converges to , so that light efficiency deterioration can be prevented.

For example, the vehicle lamp 1 of the present invention can be used for a lamp that requires diffusion characteristics among the various uses described above. For example, the vehicle lamp 1 of the present invention is a low It can be used for forming a diffusion area of a beam pattern or for enabling a tail lamp to be identified in a wider range.

Those skilled in the art to which the present invention pertains will understand that the present invention can be embodied in other specific forms without changing its technical spirit or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting. The scope of the present invention is indicated by the following claims rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be construed as being included in the scope of the present invention. do.

100: light source
200: light transmission part
210: first lens unit
211: first entrance surface
212: first exit surface
220: second lens unit
221: second entrance surface
222: second exit surface
300: body

Claims (9)

light source; and
A light transmission unit configured to transmit light generated from the light source unit to form a light irradiation area for forming a predetermined beam pattern;
The light transmission part,
a first lens unit positioned in front of the light source unit; and
A second lens unit having a smaller diameter than the first lens unit and located in front of the first lens unit;
The first lens unit and the second lens unit,
have different refractive powers,
The effective focal length of the light transmitting portion,
A distance between the focal point and a main surface located at a point where an extension line of light incident from the focal point at which the light source unit is located to the incident surface of the first lens unit and an extension line of light emitted from the second lens unit meet,
The main surface is
A vehicle lamp positioned between the light source unit and the first lens unit. According to claim 1,
The first lens unit,
It has positive refractive power,
The second lens unit,
Vehicle lamps with negative refractive power. According to claim 1,
The first lens unit,
a first incident surface on which light is incident from the light source unit; and
A first exit surface from which light incident to the first incident surface is emitted;
The first incident surface,
The center of curvature has a curvature located in front of the first incident surface,
The first exit surface,
A vehicle lamp having a curvature center of curvature located behind the first exit surface. According to claim 1,
The second lens unit,
a second incident surface on which the light emitted from the first lens unit is incident; and
A second exit surface from which light incident to the second incident surface is emitted;
The second incident surface,
A vehicle lamp having a curvature whose center of curvature is located behind the second incident surface. According to claim 4,
The second exit surface,
A car lamp with a flat shape. According to claim 4,
The second exit surface,
A vehicle lamp having a curvature center of curvature located behind the second exit surface. According to claim 4,
The second incident surface,
Vehicle lamp having a greater curvature than the second exit surface. delete According to claim 1,
The effective focal length of the light transmitting portion,
It is defined by the size of the light emitting area of the light source unit and the light irradiation range of the light irradiation area,
The light irradiation range,
A vehicle lamp that increases as the effective focal length decreases.

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