EP3121510B1 - Adaptor lens - Google Patents

Description

The present invention relates to a front optic for a semiconductor light source according to the preamble of claim 1.

Such an attachment optics has a central lens which has an optical axis and a focal region and which is adapted to generate from light incident on it from the focal region a central light bundle in which light propagates parallel to the optical axis. In this case, the propagation direction of this light defines a first spatial direction. The attachment optics furthermore has an inner side reflector which is arranged on a first side of the optical axis in a second spatial direction perpendicular to the first spatial direction. In this case, the inner side reflector is configured to generate a first sub-beam of parallel light in which propagates light in the first spatial direction, which in the second spatial direction next to the central light bundle lies.

Such an attachment optics is assumed to be known per se.

Such auxiliary optics are used to collect light of a semiconductor light source, such as a light emitting diode, and bundle. Light-emitting diodes with largely flat light-emitting surface are approximately Lambert radiators and emit their light therefore in a solid angle, which includes almost a half-space.

In order to be compliant with the rules, a signal light distribution of a motor vehicle illumination device that is to be generated from the light of the semiconductor light source must fulfill certain brightness requirements only in a much smaller solid angle range, namely +/- 20 ° in the horizontal and +/- 10 ° in the vertical. In most cases, optical attachments consist of a transparent solid. An example of such an attachment optics is from the DE 10 021 114 A1 in which a flat surface or a free-form surface serves as a light exit side. Alternatively, the light exit side may be a Fresnel structure ( DE 197 28 354 ) or a scattering structure ( US 7 222 995 ) respectively. A Fresnel lens may also be present on the light entry side of the attachment optics facing the light source. The DE 20 2005010490 U1 and DE 102010046021 A1 disclose further attachment optics known from the prior art.

The known attachment optics are more or less rotationally symmetrical, or their light exit surface has a ratio of its length to its width of almost 1: 1. Therefore, these attachment optics can not be easily used when a ratio of the length of a light exit surface to its width of, for example 2: 1 or 3: 1 or more generally, greater than 1.5: 1 is required. In a realization of such conditions with the known concepts usually dark areas arise in the illumination of the optical attachment, which is undesirable.

Against this background, the object of the invention in the specification of an optical attachment, which causes a homogeneous bright illumination of the light exit surface even at a ratio of the length of their light-emitting surface to the width, which is greater than 1.5 to 1.

This object is achieved with the features of claim 1. The intent optical system according to the invention differs from the known intent optical mentioned above in particular in that it has at least one broadside arranged further reflector and at least one outer side reflector, wherein the broadside arranged further reflector arranged in the third spatial direction on a first side of the optical axis and set up is to generate a third sub-beam of parallel light having first a direction component parallel to the first spatial direction and a direction component parallel to the second spatial direction and a direction component parallel to the third spatial direction and is directed to the outer side reflector, the outer side reflector in the first spatial direction behind arranged on the inner side reflector and in the second spatial direction on a side facing away from the optical axis of the inner side reflector and is adapted to the third sub-beam s o deflect that the light of the third sub-beam propagates in the first spatial direction, wherein the third sub-beam is in the second spatial direction on a side facing away from the optical axis of the first sub-beam next to the first sub-beam.

The broadside, i. arranged on a broad side of the optical attachment additional reflector, collects light that falls in the prior art neither on the central lens nor on one of the two side reflectors. This light would remain unused without this reflector and / or at least not specifically contribute to the generation of the desired light distribution due to a deflection in undesired spatial directions.

The fact that the broadside arranged further reflector this light parallelized and summarized to the third sub-beam, it makes it in relation to this property of parallelism to the central light beam and the first sub-light beam and the second sub-light beam and makes this otherwise lost light for the production of desired light distribution usable.

The fact that the further reflector arranged on the broad side is arranged to give the third sub-bundle first a direction component parallel to the first spatial direction and a direction component parallel to the second spatial direction and a direction component parallel to the third spatial direction, is the position of the outer side reflector to which the third side reflector Sub-beam is directed constructively fixed in the design of the attachment optics.

Characterized in that the outer side reflector in the first spatial direction behind the inner side reflector and in the second spatial direction on a side facing away from the optical axis side of the inner side reflector and is arranged to redirect the third sub-beam so that the light of the third sub-beam in the first Space direction propagated, wherein the third sub-beam in the second spatial direction on one of the optical axis remote side of the first sub-beam is adjacent to the first sub-beam, the otherwise unused light of the third sub-beam is aligned with respect to its propagation direction of the light of the central beam and the first sub-beam. The remaining difference of the light of the third sub-beam to the other bundles mentioned is that its cross-section perpendicular to the propagation direction is adjacent to the parallel cross-sections of the other bundles. This just gives the desired effect of increasing the length of the optical attachment cross section illuminated with parallel light.

A preferred embodiment is characterized in that the inner side reflector is adapted to generate the first sub-beam of parallel light so that the first sub-beam adjacent to the central light beam adjoins this, the shape of which complements.

It is also preferred that the third sub-beam lies in the second spatial direction on a side of the first sub-beam facing away from the optical axis adjacent to the first sub-beam and adjoins this, the shape of which complements.

Furthermore, it is preferred that the broadside arranged further reflector in the third spatial direction above the arranged in one of the narrow sides of the inner side reflector (21) and above the arranged also in the narrow side outer side reflector is arranged.

A further preferred embodiment is characterized in that the outer side arranged on the narrow side Side reflector in the first spatial direction behind the inner side reflector and in the second spatial direction on a side facing away from the optical axis side of the inner side reflector, that is further out than this, is arranged.

It is also preferable that the outer side reflector is realized as a flat surface.

Furthermore, it is preferred that a light exit surface of the attachment optics has molded, light-scattering cushion structures.

Another preferred embodiment is characterized in that cushion optics are molded into the light entry surface.

It is also preferred that cushion optics are molded into the reflective areas.

It is further preferred that the light exit surface has a curved basic shape.

Further advantages will become apparent from the following description, the drawings and the dependent claims. It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description.

Figur 1

eine bekannte Vorsatzoptik;

Figur 2

das Erscheinungsbild einer beleuchteten Lichtaustrittsfläche der bekannten Vorsatzoptik;

Figur 3

ein Ausführungsbeispiel einer erfindungsgemäßen Vorsatzoptik in einer perspektivischen Ansicht;

Figur 4

ein gedanklich abgeteiltes Viertel der Vorsatzoptik aus der Figur 3; und

Figur 5

ein Erscheinungsbild einer beleuchteten Lichtaustrittsfläche einer solchen Vorsatzoptik.

Show, in schematic form:

FIG. 1

a known intent optics;

FIG. 2

the appearance of an illuminated light exit surface of the known intent optics;

FIG. 3

an embodiment of a front optical system according to the invention in a perspective view;

FIG. 4

a mentally divided quarter of the intentional optics from the FIG. 3 ; and

FIG. 5

an appearance of an illuminated light exit surface of such a lens attachment.

In this case, the same reference numerals in different figures denote the same or at least functionally comparable elements.

FIG. 1 shows the initially mentioned, per se known attachment optics 10 for a semiconductor light source in a perspective view.

The known optical attachment has a central lens 12 which has an optical axis 14 and a focal region 16. The lens is adapted to generate from light incident on it from the focal area, a central light beam in which light propagates parallel to the optical axis. The propagation direction of this light defines a first spatial direction 18 that is parallel to the optical axis.

A first side reflector 20 is in front of the second spatial direction 22 perpendicular to the first spatial direction arranged optical axis 14.

A second side reflector 24 is arranged in the second spatial direction 22 to or behind the optical axis 14.

The first side reflector 20 is configured by its shape and arrangement to produce a first sub-beam of parallel light in which propagates light in the first spatial direction 18, wherein the first sub-beam is in the second spatial direction 22 in front of the central light beam. The second side reflector 24 is configured to generate a second sub-beam of parallel light in which propagates light in the first spatial direction, which lies in the second spatial direction to (behind) the central light beam. The first sub-beam and the second sub-beam are each generated from light of a light source arranged in the focal area.

With the said light bundles, that is to say the central light bundle, the first sub-bundle and the second sub-bundle, a light exit surface of the known intent optics is illuminated homogeneously with parallel light.

The FIG. 2 shows the appearance of such illuminated light-emitting surface, as it provides a viewer who views the light exit surface from a lying on the optical axis of the lens position. The ratio of the length of this light exit surface to its width is approximately 2: 1. The central, circular round light spot is generated by the central light beam. The left of it, to the circular round light spot on the left side complementary and otherwise rectangular limited light spot is generated by the first sub-beam, and the right of it, the circularly round light spot on the right side complementary and otherwise rectangular limited light spot is generated by a second sub-beam
FIG. 1 further shows that the side reflectors 20, 24 in this article in the second spatial direction, in the FIG. 1 So left and right, next to the central lens 12 are arranged. Their extension in the second spatial direction taken together defines the length of the light exit surface.

In a third spatial direction, in the FIG. 1 is a vertical direction, the thickness of the optical attachment is only slightly larger than the diameter of the central lens. The lens 12 is located at the bottom of a cylindrical recess 30. In the extreme case, said thickness is just so much larger than the lens diameter that the wall thickness of the recess in the direction of the second spatial direction 22 and the optical axis 14 perpendicular third spatial direction 28 required for stability reasons Minimum not lower.

The focal region 16 is located on the optical axis 14 in front of the lens 12. The light of a semiconductor light source 32 arranged in the focal region, which radiates into the depression, is divided into a plurality of bundles. A central bundle enters the attachment optics via the light entry surface of the central lens 12. Further light enters via the lateral surface 34 of the recess in the attachment optics.

Part of this light impinges on the side reflectors 20, 24. In addition, light also enters via the jacket surface 34 in the intent optics, which does not fall on one of the side reflectors 20, 24. This light propagates too a first broad side of the attachment optics, which here is a top surface in the third spatial direction 28, or it propagates to a second broad side of the attachment optics, which here is also a flat, lower base surface. The base surface and the top surface are mutually parallel, flat surfaces which limit the optical attachment in the third spatial direction 28, in this case upwards and downwards. At these surfaces, the light experiences internal total reflections, which redirect it into unusable areas of the optical attachment. This light is therefore lost for the generation of the desired light distribution and for the creation of the desired appearance. This lost share in the light of the light source is greater, the narrower the attachment optics in the third spatial direction.

FIG. 3 shows an embodiment of a front optical system according to the invention in a perspective view. The eye perspective corresponds to the perspective of the FIG. 1 , The optical attachment according to the invention also has a central lens 12 which has an optical axis 14 and a focal area 16. The lens is adapted to generate a central light beam from light incident thereon from the focal region 16 in which light propagates parallel to the optical axis. The propagation direction of this light defines a first spatial direction 18 that is parallel to the optical axis.

A first inner side reflector 21 is arranged in front of the optical axis 14 in a second spatial direction 22 perpendicular to the first spatial direction 18. A second inner side reflector 25 is arranged in the second spatial direction 22 after or behind the optical axis 14. The two inner side reflectors are preferably in narrow sides formed the attachment optics and thus integrally cohesive components of the attachment optics. They are preferably so-called TIR reflectors on which incident light from the focal region undergoes internal total reflections. Alternatively or in addition to their TIR properties, these reflectors can also be mirror-coated.

The first inner side reflector 21 is configured by its shape and arrangement to produce a first sub-beam of parallel light, in which propagates light in the first spatial direction 18, and in the second spatial direction 22 on a first side of the optical axis adjacent to the central light beam lies. The second inner side reflector 25 is configured to generate a second sub-beam of parallel light in which light propagates in the first spatial direction and which is in the second spatial direction on a second side of the optical axis adjacent to the central light beam.

The two inner side reflectors preferably have the shape of part of the surface of a paraboloid of revolution whose focal point is on the optical axis and whose axis of rotation coincides with the optical axis and which opens in the first spatial direction. The focal point of the paraboloid of revolution, which is real, taking into account the refraction of light at the lateral surface 34, preferably coincides with the focal region of the lens 12.

A part of the light exit surface of the optical attachment according to the invention is homogeneously illuminated with said light bundles. This homogeneously illuminated part corresponds to the homogeneously illuminated light exit surface of the known attachment optics 10 from FIG FIG. 1 , Its appearance corresponds therefore to one less sharp boundary in the second spatial direction 22 in the FIG. 2 shown appearance of the luminous attachment optics 10th

As far as described so far, the subject of the FIG. 3 , showing an embodiment of a head optical system according to the invention, not yet from the known subject of the FIG. 1 ,

In contrast to the subject of FIG. 1 has the in the FIG. 3 shown intent optics 36 additional reflectors on. These additional reflectors are located both on, or in the broad sides, as well as in the narrow sides of the attachment optics 36. These additional reflectors are preferably integrally material-bonded components of the transparent solid of the optical attachment and realized as TIR reflectors. However, they can also be mirror-coated. The intent optics after FIG. 3 can be advantageously designed without undercut.

The first broadside of the attachment optics is in the FIG. 3 the front in the third spatial direction and thus upper broadside. The second broadside of the attachment optics is in the FIG. 3 the rear in the third spatial direction and thus lower broadside. The arranged in the broadsides additional reflectors collect light that came in the known intent optics on there flat base and the top surface and was lost for the light distribution to be generated. This arrangement is also referred to in the present application as a broadside arrangement. A narrow-side arrangement analogously describes an arrangement in one of the narrow sides of the attachment optics. The narrow sides are between the broadsides.

At the same time these additional reflectors parallelize this light and direct this light of the semiconductor light source 32 intercepted in the third spatial direction 28 above and below the inner side reflectors 21, 25 to outer lateral reflectors which are at the same height as the inner side reflectors 21, 25 in the narrow sides of the Attachment optics 34 are located. These reflectors are preferably formed in the narrow sides of the optical attachment and realized as TIR reflectors or mirror-coated.

The outer side reflectors then direct this parallel light onto the light reflected parallel to the light reflected from the inner side reflectors and the light focused by the central lens so that a cross-section of the optical attachment lying at a greater length to the light propagation along the second spatial direction 22 is homogeneously illuminated than is the case in the known optical attachment 10, which works only with the central lens and the inner side reflectors.

The in the FIG. 3 Intended optics can be thoughtfully divided into four symmetrical components. A first mental division takes place along the optical axis and transversely to the second spatial direction 22 in a right and a left half. When in the FIG. 3 This orientation is a vertical section. The optical axis 14 lies in the sectional plane and the right and the left half are mirror-symmetrical to each other.

Both halves can be thoughtfully continue along the optical axis and across the third spatial direction 28 split into an upper part and a lower part. When in the FIG. 3 Orientation shown is a horizontal section. Again, the optical axis in the Section plane lie, and the upper part should be mirror-symmetrical to the lower part.

The result is four symmetrical quarters. This mental division makes sense inasmuch as each quarter already embodies the invention in its own right and the consideration reduced to a quarter facilitates understanding.

FIG. 4 shows such a quarter as representative of the entire intentional optics. This quarter corresponds to the upper left quarter of the front optics from the FIG. 3 , As FIG. 4 shows, the attachment optics 36 at least one broadside arranged further reflector 38 and at least one narrow side arranged further reflector 40. The reflector 38 has the reflection surface enclosed by the edges 38.1 to 38.4, and it is in the third spatial direction 28 behind the optical axis 14 and thus in the arrangement according to FIG FIG. 3 arranged above the optical axis 14 and above the inner side reflector 21 arranged in one of the narrow sides and above the outer side reflector likewise arranged in the narrow side. By this arrangement, he just collects the light from the focal region 16, which enters via the lateral surface 34 of the recess in the transparent solid of the optical attachment 36 and which does not fall on the inner side reflector 21. The designation of the two side reflectors 21 and 40 as an inner and outer side reflector results from their different distance in the second spatial direction to the optical axis 14, which is smaller at the inner side reflector 21 than the outer side reflector 40.

The broadside arranged further reflector 38 is set up by its shape, a third sub-beam parallel light to the first direction of a direction parallel to the first spatial direction 18 and a direction component parallel to the second spatial direction 22 and a direction component parallel to the third spatial direction 28 and is directed to a narrow side arranged further reflector 40.

Due to the determination of the parallel emission direction and the design-dictated angles of incidence of the light ultimately emanating from the focal region 16, the inclination of a surface element of the reflector reflecting precisely this ray is due to the reflection law for each ray 38, so that the shape of the entire reflective surface of the broadside arranged further reflector 38 results as the sum of such surface elements and can be calculated and produced as a free-form surface.

The narrow side outer side reflector 40 is arranged in the first spatial direction 18 behind the inner side reflector 21 and in the second spatial direction 22 on a side facing away from the optical axis 14 side of the inner side reflector, ie further out than this. Under the series arrangement is understood to mean an arrangement in which the outer side reflector extends in the first spatial direction further forward than the inner side reflector and wherein the inner side reflector protrudes counter to the first spatial direction over the outer side reflector. Both reflectors 21, 40 may overlap in the first spatial direction, but they do not have to overlap.

The outer side reflector is characterized by its arrangement and Form configured to redirect the third sub-beam so that the light of the third sub-beam propagates preferably parallel in the first spatial direction, the third sub-beam in the second spatial direction on a side facing away from the optical axis of the first sub-beam next to the first sub-beam, in particular its shape Complementing, lies. These functional features characterize the shape and arrangement of the outer side reflector with respect to the second spatial direction 22.

By defining the first spatial direction 18 as a parallel emission direction of the outer side reflector and by the design angle of incidence is due to the law of reflection for each beam, the inclination of this beam reflecting surface element of the outer side reflector fixed, so that the shape of the entire reflective surface of the outer side reflector as a sum of such surface elements results and can be calculated and produced as a free-form surface.

Since the light incident on the outer side reflector 40 from the broadside arranged further reflector 38 is already aligned parallel, the outer side reflector can be realized as a flat surface. The beams 42, 44 represent the third sub-beam.

In the embodiment shown in the FIG. 4 is shown, the third sub-beam illuminates the two left columns of the facets of the light exit surface 46. These facets are illuminated neither by the central bundle nor by the first sub-bundle. This comparison shows that the intent optical system according to the invention and in particular its light exit surface 46, with the same width in the third spatial direction 28 over a greater length in the second Direction 22 is illuminated as the known auxiliary optics 10. It is used for the illumination of the difference areas, ie the areas that are illuminated only in the intent invention optics, but not in the known intent optics, the light in the known attachment optics 10 at the level Base surface and the flat top surface is reflected in unusable areas of the optical attachment.

The light of the third sub-beam 42, 44 initially emanates from the light source arranged in the focal area 16 in radial directions, preferably having directions forward (first spatial direction), upward (third spatial direction) and lateral (opposite to the second spatial direction). As has already been explained above, this light comprises just the rays which do not fall on the central lens 12 or on an inner side reflector 21. By the invention, this light is parallelized on the broadside arranged further reflector 38 and directed forward and below the outside.

The outer side reflector 40 then directs the forward, downward and outward third sub-beams only forward, so that the downward and outward directional components disappear. The light 42, 44 in the third sub-beam then propagates vertically at the same height as the light in the central bundle and in the lateral sub-beams.

An exemplary embodiment of an entire optical attachment according to the invention results from the fact that the remaining three quarters are designed symmetrically to the quarter considered here in detail.

In a further embodiment also has one Front attachment according to the invention does not have such a symmetry. The invention is then realized, for example, in one part, for example only one quarter of the attachment optics.

The FIG. 5 shows the appearance of an illuminated light-emitting surface of such a head optical system according to the invention, as it provides a viewer who views the light exit surface from a lying on the optical axis of the lens position. The ratio of the length of this light exit surface to its width is more than 3: 1. This is, with comparable width in the third spatial direction, significantly more than in the prior art, the appearance according to Fig. 2 supplies. The greater length of the illumination is not at the expense of the illumination of the inner areas. The greater length of illumination in the invention is achieved with light that has remained unused in the prior art.

In the figures, embodiments are shown in which the light exit surfaces are provided with scattering cushion structures. These structures serve to expand the parallel aligned before the exit in extreme cases light (opening angle zero) to a standard for rule-compliant signal light distributions of automotive lights opening angle of, for example, 20 ° in the vertical and 40 ° in the horizontal.

As an alternative or in addition to such pillow optics molded into the respective light exit surface of the attachment optics, cushion optics can also be formed in the light entry surface, for example in the central lens surface.

Further alternatively or additionally, cushion optics may also be used be formed in the reflective areas. This applies both to each reflector arranged on the narrow side and to each reflector arranged on the broad side.

In a preferred embodiment, the light exit surface has a curved basic shape. Depending on the configuration, only the long sides or only the short sides are curved, so that the shape of a cylindrical lateral surface results, or both the long sides and the short sides of the light exit surface are curved, so that a curved surface in space results. Such curvature or curvature may be superimposed on the smaller cushion structures. The curvature or curvature may be convex, but it may also be concave.

In further embodiments, the light exit surface has a stepped shape or does not extend at right angles, but obliquely to the optical axis. In the case of a curved, in particular in the case of a curved light-emitting surface, the deflecting surface lying in front of it in the light path is preferably stepped in order to achieve homogeneous illumination.

Fig. 6 shows a further embodiment in which the transparent solid has a shape which kinks several times and in different directions. The kinking can be done at different angles, not just below 90 °.

Claims (10)

1. Optical element (36) for a semiconductor light source, comprising a central lens (12) having an optical axis (14) and a focal region (16) and adapted to generate from light incident thereon from the focal region (16) a central light beam in which light propagates parallel to the optical axis, the direction of propagation of said light defining a first spatial direction (18), with an inner side reflector (21), which is arranged on a first side of the optical axis in a second spatial direction (22) which is perpendicular to the first spatial direction (18), the inner side reflector (21) being designed to generate a first subbeam of parallel light, in which light propagates in the first spatial direction and which lies, in the second spatial direction, next to the central beam of light, characterized in that the optical element (36) comprises at least one further reflector (38) arranged on a broad side and at least one outer side reflector (40), said further reflector (38) which is arranged on the broad side being disposed, in a third spatial direction (28), on a first side of said optical axis and adapted to generate a third subbeam of parallel light having first a directional component parallel to said first spatial direction (18) and a directional component parallel to said second spatial direction (22) and a directional component parallel to said third spatial direction and directed toward said outer side reflector (40), the outer side reflector (40) being arranged in the first spatial direction (18) behind the inner side reflector (21) and in the second spatial direction (22) on a side of the inner side reflector (21) facing away from the optical axis, and being arranged to deflect the third subbeam in such a way that the light of the third subbeam propagates in the first spatial direction (18), the third subbeam lying in the second spatial direction (22) on a side of the first subbeam facing away from the optical axis next to the first subbeam.
2. Optical element (36) according to claim 1, characterized in that the inner side reflector (21) is adapted to generate the first subbeam of parallel light in such a way that the first subbeam, situated adjacent to the central light beam, adjoins the latter, complementing its shape.
3. Optical element (36) according to claim 2, characterized in that the third sub-bundle lies in the second spatial direction (22) on a side of the first sub-bundle facing away from the optical axis next to the first sub-bundle and adjoins the latter, complementing its shape.
4. Optical element (36) according to one of the preceding claims, characterized in that the further reflector (38) arranged on the broad side is arranged in the third spatial direction (28) above the inner side reflector (21) arranged in one of the narrow sides and above the outer side reflector likewise arranged in the narrow side.
5. Optical element (36) according to Claim 4, characterized in that the outer side reflector (40) arranged in the narrow side is arranged in the first spatial direction (18) behind the inner side reflector (21) and in the second spatial direction (22) on a side of the inner side reflector (21) facing away from the optical axis (14), i.e. further out than the inner side reflector.
6. Optical element (36) according to claim 5, characterized in that the outer side reflector (40) is realized as a flat surface.
7. Optical element (36) according to one of the preceding claims, characterized in that a light emission surface (46) of the attachment optic has formed-in, light-scattering cushion structures.
8. Optical element (36) according to one of claims 1 to 7, characterized in that cushion optics are formed into a light entry surface.
9. Optical element (36) according to one of the preceding claims, characterized in that cushion optics are moulded into the reflecting regions.
10. Optical element (36) according to one of the preceding claims, characterized in that the light emission surface (46) has a curved basic shape.

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