EP1903274A1 - Illumination unit for full and dipped headlights - Google Patents

Abstract

The illumination unit (10) has luminescence diodes (20, 220) provided with respective light-emitting chips as light sources. A primary optics (30) includes light conducting bodies (31, 231) connected downstream of respective LEDs. A secondary optics (90) is optically connected downstream of the light conducting body (31). The light conducting body (231) is optically connected upstream of the secondary optics. Light discharge surfaces of the light conducting bodies adjoin in a separation joint.

Description

The invention relates to a lighting unit having at least one light-emitting diode, which comprises at least one light-emitting chip as a light source, with a primary optics, which comprises at least one light guide body optically connected downstream of the light-emitting diode, and with a secondary optics optically downstream of the light guide body.

From the DE 103 14 524 A1 is such a light unit known. In a headlight a plurality of similar lighting units are arranged, wherein the single light unit contributes to either low beam or high beam generation.

The present invention is therefore based on the problem to develop a lighting unit with a high light output both for the low beam and for the high beam, which takes up a small space.

This problem is solved with the features of the main claim. For this purpose, the lighting unit comprises a second light-emitting diode with at least one light-emitting chip as the light source. The primary optics comprises a second light guide body, the second LED is optically connected downstream of the secondary optics and optically. The light exit surfaces of the two light guide adjacent to each other in a parting line.

Figur 1:

Dimetrische Ansicht einer Leuchteinheit;

Figur 2:

Draufsicht auf Figur 1;

Figur 3:

Anordnung der Lichtquellen;

Figur 4:

Ansicht der Lichtleitkörper von der Lichteintrittsseite;

Figur 5:

Ansicht der Lichtleitkörper von der Lichtaustrittsseite;

Figur 6:

Dimetrische Ansicht der Lichtleitkörper;

Figur 7:

Dimetrische Ansicht eines Lichtleitkörpers von unten;

Figur 8:

Längsschnitt einer Leuchteinheit;

Figur 9:

Ansicht eines Lichtleitkörpers schräg von oben;

Figur 10:

Strahlengang der Leuchteinheit;

Figur 11:

Strahlengang in den Lichtleitkörpern;

Figur 12:

Lichtverteilungsdiagramm bei Betrieb mit einer Leuchtdiode;

Figur 13:

Lichtverteilungsdiagramm der Leuchteinheit;

Figur 14:

Lichtaustrittsfläche mit versetztem Übergangsbereich;

Figur 15:

Lichtaustrittsfläche mit gekrümmten Unterkanten.

Further details of the invention will become apparent from the dependent claims and the following description of schematically illustrated embodiments.

FIG. 1:

Dimetric view of a light unit;

FIG. 2:

Top view of Figure 1;

FIG. 3:

Arrangement of the light sources;

FIG. 4:

View of the light guide from the light entrance side;

FIG. 5:

View of the light guide from the light exit side;

FIG. 6:

Dimetric view of the light guide body;

FIG. 7:

Dimetric view of an optical fiber from below;

FIG. 8:

Longitudinal section of a lighting unit;

FIG. 9:

View of a light guide obliquely from above;

FIG. 10:

Beam path of the lighting unit;

FIG. 11:

Beam path in the light guide bodies;

FIG. 12:

Light distribution diagram when operating with a light emitting diode;

FIG. 13:

Light distribution diagram of the lighting unit;

FIG. 14:

Light exit surface with offset transition region;

FIG. 15:

Light exit surface with curved lower edges.

Figures 1 and 2 show a lighting unit (10), for example, a light module (10) of a motor vehicle headlight, in a dimetric View and in a top view. The light module (10) comprises, for example, two light-emitting diodes (20, 220), a primary optic (30) and a secondary optic (90). The light propagation direction (15) is oriented by the light-emitting diodes (20, 220) in the direction of the secondary optics (90). The optical axis (11) of the light module (10) here intersects the geometric center of the light-emitting diodes (20, 220) and penetrates the primary (30) and the secondary optics (90).

The single light emitting diode (20, 220) is e.g. a light-emitting diode (20, 220), for example, in a socket (26) sits. In the illustration of Figure 3, which shows the arrangement of the light sources (22-25; 222-225), the light-emitting diode (20) is arranged at the top and the light-emitting diode (220) at the bottom. The center distance of the two light-emitting diodes (20, 221) from each other is e.g. 7.5 millimeters.

Each of the light emitting diodes (20, 220) in this embodiment comprises a group (21, 221) of four light emitting chips (22 - 25; 222 - 225) arranged in a square. Each of the light sources (22-25; 222-225) thus has two directly adjacent light-emitting chips (23, 24; 22, 25; 22, 25; 23, 24; 223, 224; 222, 225; 222, 225; 223); 224). The light-emitting chips (22-25; 222-225) of the groups (21; 221) can also be arranged in a rectangle, in a triangle, in a hexagon, in a circle with or without a central light source, etc. The individual light-emitting chip (22-25; 222-225) is square in this exemplary embodiment and has, for example, an edge length of one millimeter. The distance of the light-emitting chips (22-25; 222-225) of a group (21; 221) from each other is for example one tenth of a millimeter. An embodiment with a single light-emitting chip (22, 23, 24, 25, 222, 223, 224, 225) is also conceivable. The light-emitting diodes (20, 220) have one here transparent body having a length of, for example, 1.6 millimeters in the light propagation direction (15) from the base (26).

In the exemplary embodiment illustrated in FIGS. 1 and 2, the primary optics (30) comprise two light guide bodies (31, 231) arranged one above the other and an optical lens (81) connected downstream of the light guide bodies (31, 231) in the light propagation direction (15). The e.g. overhead light guide (31) of the light-emitting diode (20) is optically connected downstream, the underlying here light guide (231) is disposed between the lower light emitting diode (220) and the optical lens (81). The distance of the light guide body (31, 231) to the light emitting diodes (20, 220) is for example a few tenths of a millimeter, e.g. between 0.2 millimeters and 0.5 millimeters. The intermediate spaces (16, 216), cf. Figure 8, between the light-guiding bodies (31, 231) and the light-emitting diodes (20, 220) may be e.g. be filled with a silicone-like, transparent material.

The two light guide bodies (31, 231) are, for example, plastic bodies made of a highly transparent, thermoplastic material, for example: polymethacrylic acid methyl ester (PMMA) or polycarbonate (PC). This material of the light guide body (31, 231) designed, for example, as a solid body has, for example, a refractive index of 1.49. The two light guide (31, 231) have the same length, the same width and the same height in this embodiment. However, these main dimensions may also differ. The length of the light guide body (31, 231) is 13.5 millimeters in this embodiment. The light guide body (31, 231) of the light unit (10) described here can also have, for example, a length between 15 and 16 millimeters.

FIGS. 4 to 7 show the light guide bodies (31, 231) in different views. Here, FIG. 4 shows a view of the light guide bodies (31, 231) from the light entry sides (32, 132). In FIG. 5, the light guide bodies (31, 231) are shown in a view from the light exit sides (34, 234). FIG. 6 shows a dimetric view of the light guide bodies (31, 231) and FIG. 7 shows a dimetric view of the upper light guide body (31) from below. In the exemplary embodiment illustrated here, the two light-guiding bodies (31, 231) are at least approximately identical and are mutually 180 ° apart, e.g. rotated about the optical axis (11), wherein the light exit sides (34, 234) adjacent to each other.

The light entry surfaces (32, 232) facing the light sources (22, 25, 222, 225) and the light exit surfaces (34, 234) facing away from the light sources (22, 25, 222, 225) are parallel to one another in this embodiment and normal to the optical axis (11) arranged. The light entry (32, 232) and the respective associated light exit surfaces (34, 234) can also be inclined to each other. The respective light entry surface (32; 232) is here a trapezoidal, flat surface. The short baseline of the upper light entry surface (32), for example, has a length of 2.4 millimeters, is located below. The overhead long baseline of this surface (32) is, for example, 3.02 millimeters long. The lower light entry surface (232) has the same dimensions and is constructed in reverse, so that the short baselines of the two light entry surfaces (32, 232) in this embodiment are oriented to each other. The surface area of a light entry surface (32, 232) is for example 5.5 square millimeters in each case. The light entry surfaces (32, 232) can also be square, rectangular, etc. constructed.

The light exit surfaces (34, 234) each have, for example, an area of 44 square millimeters. Its height is 5.8 millimeters here, its maximum width - this is also the maximum width of the respective light guide (31, 231) - 9 millimeters. The light exit surfaces (34, 234) have in the embodiment at least approximately the shape of sections of an oval. They are e.g. in a common plane. The imaginary center line of the upper light exit surface (34), for example, offset by 7% of the height of the light exit surface (34) with respect to the imaginary center line (29) of the upper light-emitting diode (20) down. The center line of the lower light exit surface (234) is offset by this value relative to the associated light-emitting diode (220) upwards. The lower edge (35) of the upper light exit surface (34) and the upper edge (235) of the lower light exit surface (234) each have two mutually offset in height sections (36, 37, 236, 237), each by means of a connecting portion (38, 238) are interconnected. These edges (35, 235) form a parting line (35, 235) in which the light exit surfaces (34, 234), e.g. abut each other. The length of the container, for example, corresponds to the total length of the corresponding edges (35, 235). The length of the parting line (35, 235) is here 66% of the length of the light guide body (31, 231).

The side surfaces (41, 43, 241, 243) of the individual light guide body (31, 231) are arranged in mirror image to one another. They each comprise a flat surface section (42, 44, 242, 244). These surface sections (42, 44, 242, 244) lie in planes which, for example, enclose with one another an angle of 13 degrees oriented in the direction of the respective light guide body (31, 231). The imaginary line of intersection of the planes of the upper light guide body (31) lies below the light guide body (31), the line of intersection of the planes of the lower light guide body (231) is disposed above the lower optical fiber (231). The surface sections (42, 44, 242, 244) designated here as flat surface sections (42, 44, 242, 244) can also be twisted in the longitudinal direction, for example.

In the following, the boundary surfaces (51, 251) of the two bodies (31, 231) facing away from one another are referred to as cover surfaces (51, 251) of the light guide bodies (31, 231). In the illustrations of FIGS. 4 and 6, the cover surface (51) of the upper light guide body (31) is the upper boundary surface (51), the cover surface (251) of the lower light guide body (231) is the lower boundary surface (251) of the light guide body (231). , Analogously, the mutually facing surfaces (71, 271) are referred to as bottom surfaces (71, 271).

The cover surfaces (51, 251) of the light guide bodies (31, 231) in this embodiment each comprise a cylindrically mounted parabolic surface section (52, 252), a uniaxially curved surface section (53, 253) and a planar surface section (54, 254). These surface sections (52-54, 252-254) are arranged one behind the other in the light propagation direction (15), the respective parabolic surface section (52, 252) adjoining the respective light entry surface (32, 232) and the respective planar surface section (54, 254). adjacent to the respective light exit surface (34, 234). The imaginary axes of curvature of the surface sections (52, 53) lie, for example, parallel to the upper edge (33) of the light entry surface (32), the imaginary axes of curvature of the surface sections (252, 253) are parallel to the lower edge (233) of the light entry surface (232), for example.

The length of the parabolic surface sections (52, 252) is, for example, 30% of the length of the respective cover surface (51, 251). The respective focal line (55, 255) of the associated parabolic surface is located in this embodiment, for example, centrally in the associated light entry surface (32, 232). The focal line (55) is oriented, for example, parallel to the upper edge (33) of the light entry surface (32), the focal line (255) is oriented parallel to the lower edge (233) of the light entry surface (232), for example, and intersects the respective central axis (29, 229). The parabolic surface portion (52) is thus mathematically negative, ie, clockwise, curved with respect to the light propagation direction (15). The parabolic surface portion (252) is mathematically positively curved with respect to the light propagation direction (15).

In FIGS. 8 and 11, the cover surfaces (51, 251) are shown in longitudinal section as curves (61, 261) and the respective parabolic surface section (52, 252) as the parabolic section (62, 262). The parabolic sections (62, 262) are part of second order curves, for example. For example, the parabola portion (62) of the upper light guide body (31) is rotated 118 degrees clockwise from a parabola symmetrical to the upwardly oriented ordinate of a Cartesian coordinate system lying in the plane of the drawing. The imaginary pivot point of the parabola - and of the parabola-related coordinate system - is the focal point (65) as the point of the focal line (55). The abscissa of the parabolic coordinate system is the guideline of the parabola, the ordinate intersects the focal line (55). The distance of the focal point from the origin of the parabolic coordinate system in this embodiment is 1.49 millimeters. With y as the ordinate value and x as the abscissa value of the parabola-related coordinate system, the parabola shown here has at least approximately the equation: y = 0.15 * x ² + x. The parabola portion (262) of the lower light guide body (231) is correspondingly rotated in the opposite direction.

The length of the curved surface portions (53, 253) is for example 45% of the length of the light guide body (31, 231). The bending radius corresponds e.g. two and a half times the length of the light guide body (31, 231). The bending lines are outside the light guide (31, 231) on the side of the respective top surface (51, 251). The surface portion (53) of the upper light guide body (31) is thus in the representation of Figures 8 and 11 mathematically positive, counterclockwise, curved. Accordingly, the surface portion (253) of the lower light guide (231) is mathematically negatively curved. The transitions between the parabolic surface sections (52, 252) and the curved surface sections (53, 253) are tangential. The cover surfaces (51, 251) each have a turning line (56, 256) in these transitions. In longitudinal section, cf. Figures 8 and 11, the curves (61, 261) each have a turning point (66, 266).

The curved surface portions (53, 253) go over into the planar surface portions (54, 254). For example, the latter include an angle of 12 degrees with one plane normal to the light entry surface (32; 232) in which the upper edge (33) and the lower edge (233) respectively lie. In longitudinal section, the curves (61, 261) here each have a straight section (64, 264).

The upper longitudinal edges of the upper Lichtleitkörpers (31) and the lower longitudinal edges of the lower Lichtleitkörpers (231) are rounded. The radius of curvature increases in the light propagation direction (15), for example linearly from zero millimeters to four millimeters. The rounded portions (57, 257) can also be formed continuously in regions. They pass tangentially into the adjacent surfaces (41, 51, 43, 51, 241, 251, 243, 251). In FIGS. 6 and 7, as well as in FIG. 9, these transitions are shown as edges for clarity.

The respective bottom surface (71, 271) of the optical waveguide bodies (31, 231) in this exemplary embodiment comprises two mutually offset parabolic surface sections (72, 73; 272, 273) which are cylindrically mounted. The two parabolic surface sections (72, 73) of the upper light guide body (31) are rotated, for example, about a common axis, for example, the upper edge (33) of the light entry surface (32) against each other. The twist angle in this embodiment is 2 degrees, for example, in the light propagation direction (15) left parabola surface portion (73) further protrudes from the light guide body (31) than the right parabolic surface portion (72). The two parabolic surface sections (72, 73) have, for example, a common focal line (74) which, for example, coincides with the upper edge (33) of the light entry surface (32). The parabolic surface portions (272, 273) of the lower Lichtleitkörpers (231) are rotated in this embodiment by the same angular amount as the parabolic surface portions (72, 73) to each other, wherein in the light propagation direction (15) right-most parabolic surface portion (272) further from the Lichtleitkörper (231) protrudes as the left parabola surface portion (273). These two parabolic surface sections (272, 273) also have, for example, a common focal line (274) which, for example, coincides with the upper edge (233) of the light entry surface (232). The outlets of all parabolic surface sections (72, 73, 272, 273) on the light exit surfaces (34, 234) lie, for example, parallel to the optical axis (11). Here, the parabolic surface portion (72) abuts the lower edge portion (36), the parabolic surface portion (73) abuts the lower edge portion (37), the parabolic surface portion (272) abuts the lower edge portion (236) and the parabolic surface portion (273) abuts the lower edge portion (237).

In the longitudinal section shown in FIGS. 8 and 11, for example, the parabolic surface sections (72, 272) are parabolic sections (76, 276). The associated parabola of the parabola surface portion (72), for example, is rotated clockwise by 71.5 degrees with respect to a parabola which is symmetrical to the upward-oriented ordinate of a Cartesian coordinate system lying in the plane of the drawing. The imaginary pivot point of the parabola - and of the parabola-related coordinate system - is the focal point (78) as the point of the focal line (74). The abscissa of the parabolic coordinate system is the guideline of the parabola, the ordinate intersects the focal point (78). The distance of the focal point (78) from the origin of the parabolic coordinate system in this embodiment is 2.59 millimeters. With y as the ordinate value and x as the abscissa value of the parabola-related coordinate system, the parabola shown here has at least approximately the equation: y = 0.17 * x ² + 0.15 * x + 1.05. The corresponding parabola of the lower parabola surface portion (272) is twisted in the opposite direction.

In each case, between the two parabolic surface sections (72, 73, 272, 273), in each case, there is a transition region (75, 275). These transition regions (75, 275) are arranged at least approximately centrally along the respective bottom surface (71, 271). They include, for example, an angle of 135 degrees with the adjacent parabola sections (72, 73, 272, 273). The height of the transition regions (75, 275) thus increases in the light propagation direction (15). In this embodiment, the height of the transition regions (75, 275) at the transition sections (38, 238) of the light exit surface (34, 234) is 0.5 millimeters. The transition regions (75, 275) may optionally have transition radii (77). In the exemplary embodiment, the transition regions (75, 275) intersect the optical axis (11) at the light exit surfaces (34; 234). The transition regions (75, 275) may be offset from the optical axis (11). The adjacent light exit surfaces (34, 234) thus provide a large contiguous area with a continuous parting line (35, 235). Optionally, the two light guide (31, 231) may be spaced from each other, wherein the maximum distance, for example, is less than 5 millimeters.

The optical lens (81) of the primary optic (30) is e.g. a plano-convex aspherical condenser lens (81), for example a condenser lens. The plan side (82) of the lens (81) is in the representation of Figures 1 and 2 at the light exit surfaces (34, 234) of the light guide (31, 231). The optical lens (81) may be e.g. be integrated in one of the light guide body (31; 231). The maximum diameter of the optical lens (81) is for example 30% greater than the length of the light guide body (31, 231). The longitudinal section of the optical lens (81) is e.g. a segment of an ellipse whose major axis is two and a half times and whose minor axis is 160% of the length of the light guide body (31, 231). The thickness of the optical lens (81) is here 50% of the length of the light guide body (31, 231). Optionally, the light module (10) may be designed without the optical lens (81), cf. FIGS. 8 and 10.

The secondary optics (90) in this embodiment comprises a secondary lens (91). This is, for example, an aspheric plano-convex lens. The envelope of this lens is eg a sphere section. The center line (95) of the secondary lens (91) lies, for example, on the optical axis (11). The radius of the ball portion is in the illustration of Figures 1 and 2 240% and the height 110% of the length of the light guide (31, 231). The maximum distance of the plane surface (92) from the light exit surface (93), the thickness of the secondary lens (91), for example, corresponds to the length of the light guide body (31, 231). The distance of the secondary lens (91) from the light exit surface (34, 234) of the light guide (31, 231) is for example 260% of the length of the light guide (31, 231).

In operation of the light module (10), light (100) is e.g. emitted from all the light sources (22-25; 222-225) and passes through the light entry surfaces (32; 232) into the light guide bodies (31,231). Each light-emitting chip (22-25; 222-225) acts as a Lambertian emitter which emits light (100) in the half-space. The light of the upper light-emitting diode (20) occurs only in the upper light guide (31), the light of the lower light-emitting diode (220) only in the lower light guide (231).

FIG. 10 shows by way of example a beam path of a light module (10) in a longitudinal section of the light module (10). The light module (10) shown here corresponds to the light module (10) shown in FIG. The beam path within the light guide body (31, 231) is shown enlarged in FIG. 11.

FIGS. 10 and 11 show by way of example light beams (101-109; 301-309) which are emitted by two light-emitting chips (23, 25, 223, 225) arranged one above the other. The light-emitting chips (23, 25, 223, 225) are shown here as punctiform light sources. From the upper light-emitting chip (23) of the upper light-emitting diode (20), for example, the light beams (101 - 105) are shown, which are emitted offset by 15 degrees to each other. Here, for example, the light beam (101) is emitted upward by 45 degrees, while the light beam (105) is emitted downward by 45 degrees with respect to the optical axis (11) becomes. The respective light beams of the lower light emitting chip (25) of the upper light emitting diode (20) are the light beams (106-109). In the lower LED (220), the light beams (301 - 305) are shown from the upper light emitting chip (223) and the light beams (306 - 309) are shown from the lower light emitting chip (225). In the following, only the beam path of the light of the upper light-emitting diode (20) will be described, the beam path of the light of the lower light-emitting diode (220) is a mirror image of this.

Light (103) emitted from the upper light emitting chip (23) parallel to the optical axis (11) penetrates the light exit surface (34) of the light guide body (31) in the normal direction. It impinges on the plane surface (92) of the secondary lens (91) also in the normal direction, penetrates the secondary lens (91) and is broken off, for example, from the solder in the passage point when emerging from the secondary lens (91).

The light beams (102) emitted from the upper light-emitting chip (23) and enclosing an upward angle of 15 degrees and 30 degrees with the optical axis (11) impinge on an upper boundary surface (151) of the light guide body (31). This upper interface (151) is formed by the top surface (51) and has a maximum size. The respective impact point lies here in the area of the parabolic surface (52). The incident light beams (102) include with the normal at the point of impact an angle which is greater than the critical angle of total reflection for the transition of the material of the light guide body (31) with air. The upper interface (151) thus forms a total reflection surface (151) for the incident light (102). The reflected light beams (102) pass through the light exit surface (34), breaking away from the solder in the passage point become. Upon entry into the secondary lens (91), the light beams (102) lying approximately parallel here are refracted in the direction of the solder in the respective passage point and are broken away from the solder when they exit into the environment (1). The illustrated light beams (102) occur here in the lower segment of the secondary lens (91) in the environment (1).

The light (101) emitted from the upper light emitting chip (23) at an upward angle of 45 degrees is first reflected at the upper total reflection surface (151). The reflected light (101) strikes the lower boundary surface (161). The angle of incidence of the light (101) and the normal at the point of impact include an angle greater than the critical angle of total reflection. The lower boundary surface (161) thus acts for the incident light (101) as the lower total reflection surface (161). The light (101) reflected by this total reflection surface (161) penetrates through the light exit surface (34) and the secondary lens (91), whereby it is refracted as it passes through the respective body boundary surfaces (34, 92, 93). This light (101) enters the environment (1) in the upper segment of the secondary lens (91).

The light beam (104) of the upper light-emitting chip (23) shown in FIGS. 10 and 11, which includes a downward angle of 15 degrees with the optical axis (11), is not reflected in the light guide body (31). It is broken when passing through the light exit surface (34) and through the secondary lens (91). This light beam (104) lies in the lower segment of the secondary lens (91).

The light (105) emitted in said figures 10 and 11 at a downward angle of 30 degrees and 45 degrees to the optical axis (11) becomes at the lower interface (161) is totally reflected and passes under refraction through the light exit surface (34) and the secondary lens (91) into the environment (1). This light (105) lies in the upper segment of the secondary lens (91).

The light (108) emitted by the lower light-emitting chip (25) parallel to the optical axis (11) is at least approximately parallel to the light (103) of the upper light-emitting chip (23).

Light (107) emitted at an upward angle of 15 degrees strikes the upper boundary surface (151) in the region of the inflection line (56). Here it is completely reflected and passes under refraction through the light exit surface (34) and the lower segment of the secondary lens (91) through into the environment (1).

The light beams 106 shown upwardly at 30 degrees and 45 degrees from the optical axis 11 in FIGS. 10 and 11 and emitted from the lower light emitting chip 25 are formed at the upper (151) and lower (161 ) reflected.

The light rays (109) of the lower light-emitting chip (25) including a downward angle of 15, 30 and 45 degrees with the optical axis (11) are reflected at the lower boundary surface (161). Under refraction they penetrate the light exit surface (34) and the secondary lens (91). For example, the light beams (109) emerging into the environment (1) are approximately symmetrical with respect to the optical axis (11).

Of the total of the light sources (22-25) emitted light (100) is 48% at the bottom in this embodiment Boundary surface (161) reflected and 26% of the light at the upper boundary surface (151) reflected.

In the plan view, cf. 2, the light beam (100) is widened, for example, to an angle of 17 degrees.

The illumination intensity distribution (170) produced by the light module (10) during operation only with the upper light-emitting diode (20), for example on a wall 25 meters away, is shown in FIG. The optical axis (11) of the light module (10) penetrates the measuring wall, e.g. at the intersection (171) of two reference grid lines (172, 173). In this illustration, the horizontal grid lines (172) have a distance of two meters to each other on the measuring wall. The distances of the vertical grid lines (173) from each other is here e.g. five meters. The individual isolines (174) are lines of equal illuminance. Illuminance, measured in lux or lumens per square meter, increases from outside to inside in this diagram. An internal isoline (174) has e.g. 1.8 times the illuminance of a further outlying isoline.

On the measuring wall, the secondary lens (91) forms the light exit surface (34) or (83) of the primary optics (30). This light exit surface (34; 83) may be the light exit surface (34) of the light guide body (31) or the convex surface (83) of the condenser lens (81). The area (175) of the highest illuminance, the so-called hot spot (175), lies here on the right below the point of intersection (171). At the top, the illuminance decreases rapidly at the cut-off (176). The light-dark boundary (176) is here z-shaped. It has a higher section (177) on the right and a lower section (178) on the left. Both sections (177, 178) are by means of a connecting portion (179) connected to each other, which encloses an angle of eg 135 degrees with the other two sections (177, 178). In this light-dark boundary (176), the lower edge (35) of the light exit surface (34) of the primary optics (30) is imaged.

The illuminance distribution shown in FIG. 12 shows a broad illuminated area (181) whose illuminance only decreases in width at a distance of more than 15 meters from the intersection point (171). At the bottom, the illuminated area (181) has a height of e.g. four to five meters.

During operation of the light module (10) or several light modules (10), this results in a blurred limited, streak and spot-free illuminated area (181) with a sharp, z-shaped cut-off (176). During operation of the light module (10) only with the upper light-emitting diode (20), the low beam of a motor vehicle can thus be generated.

If the lower light-emitting diode (220) is switched on, the illuminance distribution (370) shown in FIG. 13 results, for example. This distribution (370) is, for example, at least approximately symmetrical to a horizontal which intersects the intersection (371) of the optical axis (11) with the measuring wall. The hot spot (375) has a large area and protrudes upwards and downwards over the mentioned horizontal line. The headlight range of a light module (10), which is operated with two light-emitting diodes (20, 220), is thus higher than the light range of a light module (10), which is operated only with the upper light-emitting diode (20). This light module (10) can thus be used to generate a high beam.

The light module (10) shown in the embodiments has a high light output due to its geometric design and requires only a small space. The relative coupling-out efficiency achievable with such a light module (10) without additional antireflection coatings is 97% of the maximum possible coupling-out efficiency. This corresponds to an absolute value of 80% to 82%.

In order to change the altitude of the light distribution, the parabolic surface portions (72, 73, 272, 273) can be rotated about the respective focal line (74, 274). Thus, in the view according to FIG. 8, a rotation of the parabolic surfaces (72, 73) of the upper light distribution body (31) in the clockwise direction causes an increase in the light distribution. At the same time - if the optical axis (11) is not adjusted - the light-dark boundary (176) can be moved upwards. The intensity of the hot spot (175, 375) is retained.

The light distribution at the measuring wall results from the superposition of different light components, cf. FIG. 10. For example, the hotspot (175) is generated by the superimposition of portions of light emitted from the upper light-emitting chip (23) in a segment between e.g. 0 degrees and e.g. 15 degrees downwards and upwards is limited with light components coming from the lower light-emitting chip (25) between, for example, 0 degrees and e.g. 15 degrees upwards and between e.g. 30 degrees and e.g. 45 is limited to the bottom. To generate the hot spot (375) additionally contribute the corresponding light components of the lower light emitting diode (220).

In order to change the intensity of the respective hot spot (175, 375), for example, the parabolic surface sections (52, 252) can be changed. Thus, for example-viewed in a longitudinal section of the light guide body 31-a rotation of the parabolic surface section can be observed (52) clockwise mean a weakening of the intensity. A change of the outlet (54, 254) of the cover surfaces (51, 251) changes the gradient of the light intensity distribution.

In addition, by shifting the beginning of the connection area, the level of illuminance can be selectively controlled in the hot spot (175, 375) and around the hot spot (175, 375). An unfavorable choice can cause a weakening of the hot spot (175, 375).

By means of the condenser lens (81), the light emerging from the light exit surfaces (34, 234) (100) can be additionally bundled. Thus, a secondary lens (91) of small diameter can be used. The convex surface (83) of the condenser lens (81) is, for example, an aspherical surface.

The distance of the secondary (90) from the primary optics (30) also influences the illumination intensity distribution. In order to concentrate the light (100) diverging exiting from the primary optics (30) at a large distance, a larger secondary lens (91) is required than at a small distance. The larger secondary lens (91) allows - with identical light guide bodies (31, 231) - the formation of the hot spot (175, 375), while forming a basic light distribution, a small distance between primary (30) and secondary optics (90) and a smaller Secondary lens (91) is required.

By means of the lateral surfaces (41, 43, 241, 243) and the rounded portions (57, 257), the light distribution on the sides of the illuminated regions (181, 381) can be influenced. A rotation of the side surfaces (41, 43, 241, 243) - at fixed edges (35, 235) - to each other reduces the width of the Light distribution diagrams (171, 371), cf. Figures 12 and 13. A reduction in the radii of the fillets (57, 257) causes a sharper transition from the illuminated to the non-illuminated area in the corners.

FIG. 14 shows a light exit surface (34) of an optical waveguide (31). The main dimensions of this light exit surface (34) correspond to the main dimensions of the light exit surface (34) shown in FIG. The transition region (75) between the parabolic surfaces (72, 73) is shifted to the left in comparison to FIG. When mounting a plurality of light modules (10) they are arranged so that during operation, the connecting portions (179) coincide. Thus, two asymmetrically split lighting profiles overlap only partially. In the middle, in the area of the desired hotspot (175) and on the z-shaped light-dark border (176), a region of high illuminance is achieved in comparison with the lateral areas. The lower light guide body, not shown here, has a transition area offset to the left by the same amount compared with the representation of FIG. 5.

The two parabolic surfaces (72, 73), as shown in Figure 15, be inclined to each other. This can be used, for example, to compensate for distorted images in the target plane. The parabolic surfaces (72, 73) may also be curved in the transverse direction. Optionally, they may be additionally modified, for example, in the third of the light guide body (31) adjoining the light exit surface (34). The lower light guide body, not shown here, is adapted accordingly, so that both bodies have a parting line at least approximately constant width at the light exit surface.

The light guiding body (31) may also comprise two underlying parabolic surfaces (72, 73) immediately adjacent to each other, e.g. inclined by 15 degrees to each other. Hereby, for example, an illumination can be generated with a 15 degree rise.

It is also conceivable to design the bottom surface (71) with only one continuous parabolic surface (72, 73), cf. FIG. 9. The lower edge (35) of the light exit surface (34) is horizontal. The associated lower Lichtleitkörper not shown here also has a horizontal edge of the light exit surface. With such a light module (10), for example, only a horizontal bright-dark boundary (176) of the low beam is generated during operation with the upper light-emitting diode (20). The corresponding light module (10) can in this case be designed so that a hot spot (175) is generated. When the lower LED is switched on, the high beam is switched on. Also in this embodiment, the top surface (51) has a parabolic surface portion (52), a curved surface portion (53) and a flat surface portion (54). Between the parabolic surface portion (52) and the curved surface portion (54) is a turning line (56).

The bottom surface (71, 271) can be described at least in regions by a family of adjacent parabolas oriented in the light propagation direction (15). These parabolas can have different parameters.

The two light guide bodies (31, 231) can have different dimensions and / or different curvatures of the corresponding surfaces.

The surfaces described here may be enveloping surfaces. Thus, the individual surface sections, for example free-form surfaces be whose envelope are, for example, parabolic surfaces. The focal lines (55, 74, 255, 274) may, for example, be shifted in the direction of light propagation (15).

It is also conceivable, for example, to carry out the parabolic surface sections (52, 252) of the cover surfaces (51, 251) with individual steps. Of a pair of adjoining interface portions of the light guide bodies (31, 231), a boundary surface portion then comprises, for example, a parabolic surface-like total reflection surface (151, 351) for the light (101-105, 306-309) emitted from the light-emitting chip (23; other interface portion comprises a total reflection area for the light (106 - 109, 301 - 305) emitted from the light emitting chip (25, 223). Optionally, the bottom surface (71, 271) can be made stepped.

LIST OF REFERENCE NUMBERS

1

Surroundings

10

Light unit, light module

11

optical axes

15

Light propagation direction

16, 216

interspaces

20, 220

Light-emitting diodes, light-emitting diodes

21, 221

Group of light sources

22 - 25

Light sources, light-emitting chips of (20)

222 - 225

Light sources, light-emitting chips of (220)

26

base

29, 229

Centerlines of (20; 220)

30

primary optics

31, 231

fiber-optic element

32, 232

Light entry surfaces

33, 233

Edges of (32; 232)

34, 234

Illuminating surfaces

35, 235

Parting line, edges of (34; 234)

36, 236

Sections of (35; 235)

37, 237

Sections of (35; 235)

38, 238

Transitional sections of (35; 235)

41, 241

faces

42, 242

flat surface sections

43, 243

faces

44, 244

flat surface sections

51, 251

cover surfaces

52, 252

Parabolic surface sections

53, 253

curved surface sections

54, 254

flat surface sections; Outlets of (51; 251)

55, 255

focal lines

56, 256

turning lines

57, 257

roundings

61, 261

curves

62, 262

Curve sections, parabolic sections

64, 264

straight sections

65, 265

Foci of (62; 262)

66, 266

turning points

71, 271

floor area

72, 272

Parabolic surface sections

73, 273

Parabolic surface sections

74, 274

focal lines

75, 275

Transition areas

76, 276

Curve sections, parabolic sections

77

Transition radius

78, 278

Foci of (76; 276)

81

optical lens, condenser lens, condenser lens

82

plan page

83

convex surface, light-emitting surface of (81)

90

secondary optics

91

secondary lens

92

plane surface

93

Light-emitting surface

95

Centerline of (91)

100

Light, light bundles

101-105

Beams of (23)

301 - 305

Beams of (223)

106-109

Beams of (25)

306-306

Light rays of (225)

151, 351

Interfaces, total reflection surfaces

161, 361

Interfaces, total reflection surfaces

170, 370

Illuminance distribution

171, 371

intersections

172

Reference grid lines, horizontal

173

Reference grid lines, vertical

174

contours

175, 375

Areas of highest illuminance, hot spots

176

Light-off

177

Section of (176)

178

Section of (176)

179

connecting portion

181, 381

illuminated areas

Claims (15)

Lighting unit (10) with at least one light-emitting diode (20; 220), which comprises at least one light-emitting chip (22-25; 222-225) as a light source, with a primary optic (30) which optically illuminates at least one of the light-emitting diodes (20; 220) comprises downstream light guide body (31, 231), and with a light guide body (31; 231) optically downstream secondary optics (90), characterized - that the light unit (10) comprises a second light emitting diode (220; 20) with at least one light-emitting chip (222 - 225; 22-25) as a light source includes, - That the primary optics (30) comprises a second light guide body (231; 31), which is optically connected downstream of the second light-emitting diode (220; 20) and the secondary optics (90) and - That the light exit surfaces (34, 234) of the two light guide (31, 231) in a parting line (35, 235) adjoin one another. Lighting unit (10) according to claim 1, characterized in that the first light-emitting diode (20; 220) comprises a group (21; 221) of light-emitting chips (22-25; 222-225) as light sources. Lighting unit (10) according to claim 2, characterized in that also the second light-emitting diode (220; 20) comprises a group (221; 21) of light-emitting chips (222-225; 22-25) as light sources. Lighting unit (10) according to claim 1, characterized in that the light exit surfaces (34, 234) lie in a plane. Lighting unit (10) according to claim 4, characterized in that the plane of the light exit surfaces (34, 234) normal to the optical axis (11) of the lighting unit (10) is arranged. Lighting unit (10) according to claim 1, characterized in that the main dimensions of the light guide (31, 231) are identical. Lighting unit (10) according to claim 6, characterized in that the length of the parting line (35, 235) is at least 50% of the length of the light guide body (31). Lighting unit (10) according to claim 1, characterized in that the primary optics (30) comprises a condenser lens (81) which is optically connected downstream of the light guide bodies (31, 231). A lighting unit (10) according to claim 3, characterized in that in each group (21, 221) of light-emitting chips (22-25; 222-225) they are arranged so that each light-emitting chip (22-25; 222-225) is inside the group (21; 221) has at least two immediately adjacent light-emitting chips (23, 24; 22, 25; 22, 25; 23, 24; 223, 224; 222, 225; 222, 225; 223, 224). Lighting unit (10) according to claim 1, characterized in that the geometric center line (95) of the secondary optics (90) coincides with the optical axis (11) of the lighting unit (10). Lighting unit (10) according to claim 1, characterized in that each two the light guide (31, 231) delimiting surfaces (51, 71, 251, 271), oppositely curved surface portions (52, 72, 252, 272). Lighting unit (10) according to claim 11, characterized in that the surface portions (52, 72; 252, 272) are curved parabolic. Lighting unit (10) according to claim 1 or 11, characterized in that at each Lichtleitkörper (31, 231) at least one of the light guide (31, 231) delimiting surfaces (51, 71, 251, 271) at least two curved and offset from one another Having surface portions (72, 73, 272, 273) which are rotated against each other about the intersection of the light entry surface (32, 232) with the respective oppositely disposed surface (71; 51; 271; 251). Lighting unit (10) according to claim 13, characterized in that in each light guide body (31, 231) the two surface sections (72, 73; 272, 273) are connected by means of a transition region (75; 275). Lighting unit (10) according to claim 14, characterized in that the respective transition region (75, 275) with the two surface portions (72, 73, 272, 273) each encloses an angle of 135 degrees.

Images