KR101614684B1 - Plastic achromatic lens for headlight - Google Patents

Abstract

The present invention relates to a plastic acromatic lens, and more particularly, to a plastic acromatic lens having an incident light lens unit having a horizontal light incidence surface on which light is incident and having a concave lens surface on which light is emitted and formed of a first material having optical characteristics corresponding to the flint glass, ; And an outgoing lens part having a convex aspherical surface and a second material having optical characteristics corresponding to the crown glass, the convex aspherical surface being coupled to the concave lens surface of the incident light lens part, And is coupled to the incident light lens unit so as to surround the entire area excluding the light incidence plane.

Description

[0001] PLASTIC ACHROMATIC LENS FOR HEADLIGHT [0002]

The present invention relates to a headlight lens, and more particularly to a plastic acromatic lens in which chromatic aberration is corrected.

Generally, automobiles are equipped with various equalization devices. Among them, the headlight is an important equalizer that secures the driving view of the driver at night. In this regard, a headlight structure for an automobile is disclosed in Japanese Patent Application Laid-Open No. 2003-0048708.

As headlights used in automobiles in the past, aspherical lenses molded and processed in glass are used. Glass lenses are heavier than plastic lenses, have lower productivity, and have a higher production cost. In recent years, the headlamps have been converted into LEDs, and plastic lenses with high price competitiveness are urgently needed to cope.

In addition, the plastic lens has a lower stiffness than the glass lens. In order to cope with this problem, the use of polycarbonate material can compensate for the stiffness, but Abbe's number is significantly lower than that of glass, which is disadvantageous in that it lacks the function as an optical material.

In addition, when a lens is manufactured using acrylic, which is a general plastic optical material, its rigidity is low and yellowing may occur when exposed to ultraviolet rays such as LED.

SUMMARY OF THE INVENTION An object of the present invention is to provide a new type of plastic acromatic lens capable of correcting chromatic aberration while having strength and optical characteristics corresponding to glass.

The above objects and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention by those skilled in the art.

The object of the present invention can be achieved by a plastic acromatic lens. The plastic acromatic lens of the present invention comprises: an incident-light lens unit having a concave lens surface having a horizontal light incidence surface on which light is incident, a light outgoing surface, and formed of a first material having optical characteristics corresponding to the flint glass; And an outgoing lens part having a convex aspherical surface and a second material having optical characteristics corresponding to the crown glass, the convex aspherical surface being coupled to the concave lens surface of the incident light lens part, And is coupled to the incident light lens unit so as to surround the entire area excluding the light incidence plane.

According to one embodiment, the first material is polycarbonate and the second material is acrylic (PMMA).

According to an embodiment of the present invention, the incident-light lens unit has a sloped side slope surface connecting the light-entering surface and the concave lens surface, and the outgoing lens unit is formed to be convex in a conical shape about the convex aspheric surface, Wherein a concave lens surface is formed at a depth corresponding to the concave lens surface to form a coupling surface to be in contact with the concave lens surface, and a rim area surrounding the coupling surface extends toward the light entering surface, And a side coupling vane coupled to be enclosed.

According to one embodiment, the incident light lens unit and the outgoing lens unit are integrally manufactured by injection molding, and a first resin for injecting a first resin corresponding to the first material during injection molding is formed on one side of the light- And a headlight flange coupling region of the side coupling vane is connected to a second resin injection port for injecting a second resin corresponding to the second material during injection molding.

According to one embodiment, the light-incident lens unit is divided into a use surface and an unused surface for irradiating light to the outside when coupled to the inside of the headlight, and the unused surface corresponds to a convex aspherical lens surface of the outgoing lens portion A convex bonding surface may be provided which is convexly formed to improve the bonding area with the outgoing lens unit and reduce the amount of the second material used.

The plastic acromatic lens of the present invention has optical characteristics of a conventional glass acromatic lens formed of a flint glass and a crown glass, and is made of a relatively inexpensive plastic, so that a manufacturing cost is low and a processing characteristic is easy.

In addition, since the concave lens surface and the convex aspherical surface are provided, the chromatic aberration can be corrected. In addition, it is possible to reinforce the stiffness which has been raised as a problem of the conventional plastic lens, and to minimize the sulfur change.

1 is a schematic view showing a configuration of an achromatic lens made of conventional glass,
2 is a schematic view showing a configuration of a plastic acromatic lens according to the present invention,
Fig. 3 is an exploded perspective view of the plastic acromatic lens according to the present invention,
4 is a schematic view showing a configuration of a plastic acromatic lens according to another embodiment of the present invention.

For a better understanding of the present invention, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. The embodiments of the present invention may be modified into various forms, and the scope of the present invention should not be construed as being limited to the embodiments described in detail below. The present embodiments are provided to enable those skilled in the art to more fully understand the present invention. Therefore, the shapes and the like of the elements in the drawings can be exaggeratedly expressed to emphasize a clearer description. It should be noted that in the drawings, the same members are denoted by the same reference numerals. Detailed descriptions of well-known functions and constructions which may be unnecessarily obscured by the gist of the present invention are omitted.

FIG. 2 is a schematic view showing the construction of the plastic acromatic lens 100 according to the present invention, and FIG. 3 is an exploded perspective view showing the structure of the plastic acromatic lens 100 in an exploded manner. As shown in the figure, the plastic acromatic lens 100 according to the present invention is used in combination with a headlight of a vehicle. The plastic acromatic lens 100 includes an incident light lens unit 110 through which light is incident from a light source (not shown) in a headlight (not shown), an outgoing lens unit 110 coupled to the incident light lens unit 110, (120).

The incident light lens unit 110 includes a horizontal light incidence surface 111 and a concave lens surface 113 formed to have a predetermined thickness from the light incidence surface 111 and having a plate surface recessed therein, And the side slope 115 is inserted into the side slope 115. Here, the incident light lens unit 110 is formed of a first material having optical characteristics of flint glass, and the outgoing lens unit 120 is formed of a second material having optical properties of crown glass.

The lower region of the incident light lens unit 110 is fixed to the flange (not shown) of the headlight (not shown).

1 is a schematic view showing the configuration of an achromatic lens 10 made of glass for correcting chromatic aberration and spherical aberration. The plastic acromatic lens 100 of the present invention shown in FIG. 2 combines the flammable glass 13 and the crown glass 11 to correct the chromatic aberration and the spherical aberration, as shown in FIG. 1, It is made of plastic material to manufacture, which reduces manufacturing cost and improves productivity. That is, a conventional glass-made achromatic lens 10 which minimizes the chromatic aberration by using the condensation and dispersion of the crown glass 11, which is a convex lens having a different refractive index and the Abbe's number, and the concave lens 13, . For this, the first material of the incident light lens unit 110 may be formed of PC (polycarbonate), and the second material of the light output lens unit 120 may be formed of PMMA (acrylic).

The chart below shows acrylic (PMMA), crown glass, polycarbonate (PC). Fig. 6 is a chart showing the optical characteristics of the flint glass. Fig. As shown, acrylic has optical properties similar to crown glass, and polycarbonate has optical properties similar to flint glass.

PMMA Crown glass PC Flint glass Refractive index 1.491 1.523 1.586 1.63 Abe number 57.6 58.5 (55-70) 29.9 20 to 50 Transmittance
(%) 92 92 88 87

The transparency of acrylic and polycarbonate is almost equivalent to that of crown glass. In addition, the refractive index and the dispersion ratio of acrylic have almost the same values as those of crown glass. The refractive index of the polycarbonate is larger than that of the crown glass, but on the contrary, the Abbe number is small and the dispersion is large.

In addition, acrylic and polycarbonate are plastic, so they are lighter than glass. Compared to the specific gravity of 2.53 of inorganic glass, acrylic is 1.19 and polycarbonate is 1.20. As a result of the impact strength test, acrylic and polycarbonate exhibit a large strength of 5.6 and 92, respectively.

The incident light lens unit 110 is formed of a polycarbonate material and the light output lens unit 120 is formed of an acrylic material. The incident light lens unit 110 has a concave lens surface 113, and the outgoing lens unit 120 Has a convex aspheric lens surface 123, so that chromatic aberration and spherical aberration are corrected, resulting in higher productivity and lower manufacturing cost than glass.

The outgoing lens section 120 has a coupling surface 121 coupled to the concave lens surface 113 and a convex aspherical lens surface 123 formed so as to protrude in the direction opposite to the coupling surface 121 and to emit light .

Here, the plastic acromatic lens 100 according to the present invention is different from the glass acromatic lens 10 of FIG. 1 in that the outgoing lens unit 120 surrounds the entire area excluding the light incidence plane 111 of the incident light lens unit 110 .

That is, the outgoing lens part 120 is formed in a conical shape as a whole, and is recessed corresponding to the concave lens surface 113 from the lower area to the central area to form the engaging surface 121. The coupling blade 125 is formed to extend in the ring shape along the edge area of the coupling surface 121 to the light incidence surface 111. And the incident light lens unit 110 is inserted into a space between the coupling wing 125 and the coupling surface 121 formed inside the coupling wing 125. When the exit light lens unit 120 is bonded or injected in the form of being laminated on the upper part of the incident light lens unit 110 like the conventional glass hermetic lens 10 of FIG. If the bonding surface is exposed to the outside, defects may occur and optical properties may be deteriorated.

Since the concave lens surface 113 and the coupling surface 121, which are the coupling regions of the light output lens unit 120 and the incident light lens unit 110, are hidden from the inside, the defect ratio is reduced, and a clean appearance and uniform optical characteristics are provided can do.

Here, the plastic acromatic lens 100 according to the present invention may be manufactured by injection molding, or may be manufactured by joining an incident light lens unit 110 and an output light lens unit 120, which are respectively manufactured by bonding.

Among them, when manufacturing the plastic acromatic lens 100 by integrally injecting the first material and the second material at one time by injection molding, the material forming the incident light lens unit 110 and the light output lens unit 120 are different The cooling rate and the shrinkage rate may be different. When the incident light lens unit 110 is inserted into the light output lens unit 120 as in the present invention, that is, when the side surface coupling surface 117 of the incident light lens unit 110 is coupled to the coupling wing 125 And the concave lens surface 113 and the engaging surface 121 are joined to minimize the deformation during injection molding.

In addition, since the coupling vanes 125 of the output lens unit 120 surround the outside of the incident-light lens unit 110, the bonding area can be widened and the stability of the bonding can be enhanced.

A first receiving tube 118 is formed in the lower portion of the side fitting surface 117 and a second receiving tube 128 (not shown) is attached to one side of the coupling vane 125, that is, Is formed. Since the resin injection tube is formed in the lower region of the plastic acromatic lens 100, that is, the region coupled to the flange of the headlight of the vehicle, during the injection molding,

In addition, since the second water intake tube 128 injects resin on the side of the concave lens surface 113, the direct heat transmitted to the concave lens surface 113 is reduced, and the deformation can be reduced.

As described above, the plastic acromatic lens of the present invention has the optical characteristics of the conventional glass acromatic lens formed of the flint glass and the crown glass, and is manufactured at a relatively low price, so that the manufacturing cost is low and the processing characteristic is easy.

In addition, since the concave lens surface and the convex aspherical surface are provided, the chromatic aberration can be corrected. In addition, it is possible to reinforce the stiffness which has been raised as a problem of the conventional plastic lens, and to minimize the sulfur change.

4 is a schematic view schematically showing the configuration of a plastic acromatic lens 100a according to another embodiment of the present invention.

The plastic acromatic lens 100a according to another embodiment of the present invention has a structure in which the use surface and the unused surface are different from each other.

A headlight (not shown) reflects the light generated by the light source by a reflection plate and enters the lens. At this time, a part of the reflection plate is clogged and the light is not reflected to the entire area of the lens, but is reflected only to a part of the use surface and is discharged to the outside.

For example, as shown in FIG. 4, the upper portion may be an unused surface and the lower portion may be a used surface with respect to the central axis X. The plastic acromatic lens 100a according to another embodiment of the present invention has a different structure because the unused surface may have a lower optical characteristic than the surface to be used.

The use surface has a shape in which the concave lens surface 113 and the coupling surface 121 are coupled to each other like the plastic acromatic lens 100 of the preferred embodiment described above.

On the other hand, the unused surface is formed so that the front end of the incident-light lens unit 110 has the convex joining surface 122 convexly formed like the convex aspheric lens surface 123.

In this case, since the thickness between the convex aspheric lens surface 123 and the convex tangent surface 122 becomes thin, the amount of the second material used is reduced. It is difficult to uniformly control the optical characteristics as the amount of the second material increases, thereby preventing the defect rate from becoming high.

Further, as compared with the above-described preferred embodiments, since the area of the inner joining surface of the incident light lens unit 110 and the light-exiting lens unit 120 is further increased, the stability and reliability of the joint can be further enhanced.

The embodiments of the plastic acromatic lens of the present invention described above are merely illustrative and those skilled in the art will appreciate that various modifications and equivalent embodiments can be made without departing from the scope of the present invention. It will be possible. Therefore, it is to be understood that the present invention is not limited to the above-described embodiments. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims. It is also to be understood that the invention includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

100: Composite plastic lens for headlight
110: incident light lens unit 111:
113: concave lens surface 115: side inclined surface
117: side coupling surface 118: first receiving groove inlet
120: exit light lens part 121: coupling surface
123: convex aspheric lens surface 125: coupling wing
127: inner engaging surface 128: second receiving groove inlet

Claims (5)

An incident light lens unit having a concave lens surface on which a light is incident and having a concave lens surface on which light is emitted and formed of a first material having optical characteristics corresponding to the flint glass;
And an outgoing lens part formed of a second material having a convex aspherical lens surface coupled to the concave lens surface of the incident light lens part and having a convex aspherical surface to which light is emitted and having an optical characteristic corresponding to the crown glass,
Wherein the outgoing lens unit is coupled to the incident light lens unit so as to surround the entire area of the incident light lens unit excluding the light incident side,
Wherein the first material is a polycarbonate (PC) having an Abbe number of 29.9 and the second material is a polymethyl methacrylate (PMMA) having an Abbe number of 57.6.
delete The method according to claim 1,
The light-
And an inclined side surface inclined to connect the light incidence surface and the concave lens surface,
The outgoing lens unit includes:
Wherein the concave lens surface is convexly formed in a conical shape about the convex aspheric lens surface, the concave lens surface is recessed at a depth corresponding to the concave lens surface to form a coupling surface to be in contact with the concave lens surface, And a side coupling vane extending toward the light incidence surface and coupled to surround the outside of the side inclined surface.
The method of claim 3,
The light-
When coupled to the interior of the headlight, it is divided into a use surface for irradiating light to the outside and a non-use surface,
Wherein the non-use surface is convexly formed so as to correspond to a convex aspherical lens surface of the outgoing lens part to improve a bonding area with the outgoing lens part and to reduce an amount of use of the second material. A plastic acromatic lens.
The method according to any one of claims 1, 3, and 4,
Wherein the light incident lens portion and the light exit lens portion are integrally manufactured by injection molding,
A first resin inlet port for injecting a first resin corresponding to the first material during injection molding is connected to one side of the light incidence surface,
Wherein the headlight flange coupling region of the side coupling vane is connected to a second resin injection port for injecting a second resin corresponding to the second material during injection molding.

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