WO2006119735A1

WO2006119735A1 - Led illumination module

Info

Publication number: WO2006119735A1
Application number: PCT/DE2006/000777
Authority: WO
Inventors: Rainer Opolka; Andreas Timinger
Original assignee: Zweibrüder Optoelectronics GmbH
Priority date: 2005-05-12
Filing date: 2006-05-05
Publication date: 2006-11-16
Also published as: ES2326389T3; DK1880139T3; CN100549505C; DE502006003613D1; EP1880139B1; EP1880139A1; DE202005007500U1; HK1108730A1; CN101018975A; ATE430286T1

Abstract

The invention relates to an LED illumination module having an LED (23) and a rotationally symmetrical, integral, light-transparent auxiliary optic (10) having an inner converging lens part (14) and an outer reflector part (16). The auxiliary optic (10) has an opening (11) in the form of a blind hole which is arranged at the rear and in which the LED (23) can be displaced longitudinally and axially along the optical axis (20) such that, owing to the displacement, a change in the cone of light from a cone of light having a cone angle < 12° to a cone angle > 20° can be produced and, in at least one LED position with respect to the opening (11) of the auxiliary optic (10), an inner region of the cone of light is illuminated homogeneously over a cross-sectional area at right angles to the optical axis (20).

Description

A

LED lighting module

The invention relates to an LED lighting module with an LED and a rotationally symmetrical one-piece light-transparent optical attachment, which has an inner collection lens part and an outer reflector part and a rear baghole-like opening.

Such LED lighting modules are used for example in flashlights. The flashlights known from the prior art, which are equipped with a light bulb, have z. T. a conically widening to the end face lamp head, in the interior of which a mostly parabolic trained concave mirror is arranged in the focal point of the incandescent lamp or its filament is arranged. By this arrangement, an optimal light efficiency should be ensured. Disadvantageously, such concave mirror surfaces can easily become dirty or the mirror surface can fade by corrosion effects, so that the reflection of the light is weaker.

More recently, flashlights have come on the market, which are equipped with a light-emitting diode. Light-emitting diodes consume significantly less power than incandescent lamps and can usually be operated with a lower operating voltage, so that small battery bodies (mignon cells) are sufficient as a power source. In particular, by using light-emitting diodes flashlights can be made in a smaller design, so that they are conveniently carried along as a key fob or the like. In addition to the lower power consumption, light-emitting diodes prove by design to be particularly shock and impact insensitive. In addition, light emitting diodes have an extremely long life, so that eliminates a lamp replacement, which is often necessary in the past. Even with LEDs as a light source, the given light emission should be optimally utilized. The possible use of a reflector, which can be found partly in lamps, has the disadvantages already mentioned. In addition, it is desirable to be able to save this component as well. In some of the flashlights known in the prior art, a converging lens is disposed on the light exit surface, which radiates substantially a parallel light beam in a position in which the location of the light emissions at the focal point of this condenser lens is arranged. In a further development, a longitudinally displaceable lamp head has been proposed, which allows the position of the converging lens to vary the LED. As a result, the light beam charac- teristics can be changed within certain limits. However, this design can only be used in such light-emitting diodes whose radiation is already bundled forward. If the light emitting diodes also radiate relevant portions of the light to the side, that is at a high angle to its axis, this light is not used. Today's high-performance light-emitting diodes are z. T. built so that the radiation exits at a large angle to the axis. For such light-emitting diode optical attachments are useful.

According to the prior art, lens bodies are known, which are formed prism-shaped or beam-like solid with a flat or slightly convexly curved end face. At the back of these lens body have a recess into which protrudes the LED glass body. The annular surface of the LED base is in this case flat on the corresponding annular surface of the lens body, wherein the light emitting point of the LED is arranged stationary so that the light emitted in the region of the optical axis to the aperture light is to be refracted via the collimator effect to a parallel light beam. The light emitted at a larger angle to the optical axis is totally reflected when the so-called critical angle is exceeded and deflected in accordance with the surface curvature and the resulting reflection angle. In such, for example, from US 6,478,453 B2 or US 6,547,423 B2 known attachment optics, the radiation characteristics of the lamp is set.

It is an object of the present invention to further develop a lighting module consisting of an LED and an optical attachment.

This object is achieved by the LED lighting module according to claim 1. The rotationally symmetrical one-piece light-transparent front optics has an inner collecting lens part and an outer reflector part and a rear bag hole-like opening which is delimited by a conical or cross-sectionally curved conical surface and a convexly curved base and which has a cladding diameter, one along the optical Axis of the auxiliary lens allowed longitudinal axial displacement of the LED body in the opening. By this is meant that the longitudinal axial displacement of the entire, consisting of the LED glass body and the socket arrangement in the blind hole-like bore is possible, so that by a relative movement of the LED to the blind hole along the optical axis different radiation characteristics with different cone angles of the light beam are variably adjustable.

The collecting lens part has a convexly curved base surface as a light entry surface and a front, likewise convexly curved light exit surface. The reflector part which adjoins the outside immediately in the context of the one-piece optical attachment is essentially formed by the lateral surface of the blind-hole-like opening as the light entry surface, an outer shell-shaped lateral surface as the surface totally reflecting the light, and a front conical light exit surface. All Lichteintritts- and light exit surfaces break obliquely incident light beams such that the light emitted by the LED light is emitted substantially completely, in particular more than 85% forward and by the longitudinal axial displacement of the entire LED a light cone change of a cone of light with a cone angle <12 ° can be generated up to a cone angle> 20 °. In at least one relative LED position relative to the blind-hole-like opening of the attachment optics, an inner light cone region can be homogeneously illuminated over a cross-sectional area perpendicular to the optical axis, preferably in such a way that a circle of 0.80 m in diameter is homogeneously illuminated at a distance of 2.5 m. Since it only depends on the relative displacement of the LED to the attachment optics, this goal can be achieved either by a longitudinally displaceable attachment optics with permanently mounted LED or by a längsaxial displaceable LED with permanently mounted attachment optics or - by combined displacement of the attachment optics and the LED. Preferably, the solution is selected such that the attachment optics is arranged in a longitudinal axis relative to a remaining lamp body, in which the LED is permanently installed, slidable lamp head. Possibly. For this purpose, a longitudinal axial or helical guide can be provided.

The displacement of the LED respectively from the focal point and from a focal plane of a lens body in both directions, resulting in narrow or wide emissions, d. H. Light beam with smaller or larger diameter, is known in principle according to the prior art. However, the main aim so far has been to produce a bundle of light rays with a largely parallel array of individual light rays. In the case of an intended strict parallelism of the light beams, however, the illuminated field would be limited to the diameter of the attachment optics assuming a punctiform light source. Although displacements of the LED from the focal plane lead to a widening of the light cone, the light intensity decreases radially outward as the distance from the optical axis increases. By forming the attachment optics in the manner of a Fresnel lens with a collection lens part and a reflector part, the Kollimatoreigenschaft the converging lens can be combined with the reflector property of the outer intent optical part in such a way that converging as divergent light beams in certain positions of the light emitting diode to the optical attachment illuminate a homogeneous surface , in particular in 2.5 m distance in a diameter of 80 cm.

The light-refracting or totally reflecting surfaces can be calculated using a 2 D tailoring technique.

Further developments of the invention are described in the subclaims.

Thus, the angle of inclination, under which the light exit surface of the reflector part is arranged against a vertical to the optical axis, between 35 ° and 40 °, preferably selected at 37 °. The smallest diameter a conical opening should - be at least 9 mm, thus allowing to turn the light-emitting diodes all popular ^~ finally socket in the opening are moved longitudinally axially, also in such a way that the LED can be inserted together with the base in the rear opening. The total height of the attachment optics should be between 9 mm and 16 mm, which is possible by combining a collecting lens part with an outer reflector part. Preferably, the inner diameter of the collecting lens part is at most 1 mm larger than the largest diameter of the opening of the attachment optics.

The reflector part may according to a further embodiment of the invention have outer edge surface pieces which are arranged parallel to the optical axis of the attachment optics. This ensures that the formation of stray light in the edge area is prevented.

The reflector part may further comprise outer annular surface pieces, which are arranged around the opening and perpendicular to the optical axis and / or which are arranged outside and perpendicular to the optical axis. In particular, the ratio of the diameter of the attachment optics to the height thereof is selected between 0.4 and 0.5 and preferably between 0.44 and 0.49. The ratio of the thickness of the inner condenser lens to the height of the attachment optics is optimally between 0.6 and 0.65, preferably 0.614. The ratio of the diameter of the inner collective lens part to the diameter of the optical attachment is between 0.5 and 0.55. Finally, the inner collection lens part has a light exit surface whose radius of curvature is smaller than the radius of curvature of the light entry surface. The collecting lens part according to the invention has an opening angle of at least 40 °, preferably 42 °.

The attachment optics is preferably made of plastic, in particular PMMA or glass.

Further advantages of the invention will be explained with reference to the drawings. Show it FIGS. 1 to 4 each show different radiation characteristics with two different optical attachments in a schematic representation and

Fig. 5 shows a cross section through a concrete optical attachment according to the present invention.

The intent optics, which acts as a lens body, has a rear blind-hole-like opening 11, which is bounded by a conical lateral surface 12 and a convexly curved base surface 13. This base surface 13 is also the light entrance surface of an inner collecting lens part 14, which has a convexly curved light exit surface 15 on the front side. The collecting lens part 14 is surrounded by a reflector part 16, which is essentially formed by the lateral surface 12 as a light entry surface and an outer shell-shaped lateral surface 17 as the total light reflecting surface and a front conical light exit surface 18. As shown, the reflector portion 16 may still have wall portions 19 which are parallel to an optical axis, further edge portions 21, 22 which are perpendicular to the optical axis. The overall diameter of the attachment optics shown in FIG. 5 can be, for example, 20 mm, 25 mm or 36 mm, in each case with a height of 9 mm, 11 mm or 16 mm. The opening 11 is where wide or the diameter of this opening is so large that an LED 23, which is schematically indicated in Fig. 5, along with the base along the optical axis (see double arrow 24) can be moved. Different radiation characteristics result from FIGS. 1 to 4. A relatively narrow bundling with a circular area of 0.8 m, which is homogeneously illuminated, for example, in 2.5 m results in a position according to FIG. 1. The light mimicked by the LED 23 becomes light , as far as it meets the light entry surface 13, broken and leaves the collecting lens inner part 14 through the light exit surface 15 with a repeated refraction of light. The marginal rays pass over the conical surface 12, where they undergo refraction, on the outer shells 17 where they are totally reflected and finally occur after refraction at the light exit surface 18 to the front. With the attachment optics 10 and the lens 23 in the illustrated Position obtained beam characteristic consists of a relatively tightly focused light cone with a small cone angle.

In the position of the LED 23 shown in FIG. 2, in which the LED is further pushed into the opening 11, however, results in a radiation characteristic in which the light rays diffracted from the collecting lens part 14 diverge and converge originating from the reflector part light rays, which resulting from different calculation and reflection angle.

In Figs. 1 and 2, a lens in a relatively flat construction was used. The lens shown in Figs. 3 and 4 differs from this by a greater height, in which the lateral surfaces 17 have been extended "forward and backward", so that a relatively deeper ^' blind hole 11 and a further projection of the front surfaces 18 opposite the inner light exit surface 15. In Fig. 3 and Fig. 4, the light emitting diode 23 is shown in each case in different positions to the optical attachment 10, resulting in correspondingly different light characteristics.

Modifications are also possible within the scope of the present invention such that the surfaces 12 can be spherical or aspherical and the surfaces 14 and 15 can be spherical or flat (and not aspherical as shown).

The attachment optics is preferably made of PMMA and can be used in particular in 12 V beams and in flashlights.

Claims

claims

1. LED lighting module with a light-emitting diode (LED) (23) and a rotationally symmetrical, one-piece, light transparent front optics (10) with an inner collection lens part (14) and an outer reflector part (16) with a rear blind hole-like opening (11) through a conical or in cross-section arcuate, conical lateral surface (12) and a convexly curved base (13) is limited and which has a cladding diameter, along the optical axis (20) of the auxiliary lens (10) längsaxiale displacement of the LED body (23 ) in the opening (11), wherein the collecting lens part (14) by the convex curved base (13) as a light entrance surface and a front, also convex light exit surface (15) and the reflector part (16) substantially through the lateral surface (12) the opening as a light entrance surface, an outer shell-shaped lateral surface (17) as the light totally reflecting surface and egg ne front conical light exit surface (18) is formed, wherein all light entrance and light exit surfaces (12, 13, 15, 18) break the obliquely incident light beams such that the emitted light from the LED substantially completely, in particular more than 85% after By the longitudinal axial displacement of the LED (23) a light cone change from a cone of light with a cone angle <12 ° up to a cone angle> 20 ° can be generated and wherein in at least one LED position to the opening (11) of the attachment optics (10 ) an inner light cone area over a cross-sectional area perpendicular to the optical axis is homogeneously illuminated, preferably in 2.5 m distance, a circle of 0.80 m in diameter is homogeneously illuminated.

2. LED lighting module according to claim 1, characterized in that the angle of inclination (α) below which the light exit surface (18) of the reflector part (16) is arranged against a vertical to the optical axis (20), between 35 ° and 40 °, preferably at 37 °.

3. LED lighting module according to claim 1 or 2, characterized in that the smallest diameter of a conical opening> 9 mm.

4. LED lighting module according to one of claims 1 to 3, characterized in that the total height of the optical attachment is between 9 mm and 16 mm.

5. LED lighting module according to one of claims 1 to 4, characterized in that the diameter of the collecting lens part is at most 1 mm larger than the largest diameter of the opening (11) of the attachment optics (10).

6. LED lighting module according to one of claims 1 to 5, characterized in that the reflector part (16) has outer ring surface pieces (19) which are arranged parallel to the optical axis of the attachment optics.

7. LED lighting module according to one of claims 1 to 6, characterized in that the reflector part (16) outer ring surface pieces (21, 22) which are arranged around the opening (11) and perpendicular to the optical axis and / or the front side are arranged outside and perpendicular to the optical axis.

8. LED lighting module according to one of claims 1 to 7, characterized in that the ratio of the diameter of the optical attachment to its height between 0.4 and 0.5, preferably between 0.44 and 0.49.

9. LED lighting module according to one of claims 1 to 8, characterized in that the ratio of the thickness of the inner converging lens to the height of the optical attachment is between 0.6 and 0.65, preferably at 0.614.

10. LED lighting module according to one of claims 1 to 9, characterized in that the ratio of the diameter of the inner collecting lens part to the diameter of the optical attachment is between 0.5 and 0.55.

11. LED lighting module according to one of claims 1 to 10, characterized in that the inner collecting lens part (14) has a light exit surface (15) whose radius of curvature is smaller than the radius of curvature of the light entry surface (13).

12. LED lighting module according to one of claims 1 to 11, characterized in that the collecting lens part (14) has an opening angle of> 40 °, preferably 42 °.

13. LED lighting module according to one of claims 1 to 12, characterized in that the attachment optics made of plastic, preferably PMMA ₁ or glass.