DE20110813U1 - flashlight - Google Patents

Description

flashlight

The present invention relates to a flashlight with light-emitting diodes.

Flashlights with LEDs as light sources are generally well known. In newer models of such lamps, focusing elements are provided in front of the LEDs in the direction of radiation in order to bundle the light from the LEDs and thus achieve sufficient illumination even at greater distances over a limited area.

When using multiple LEDs, which are necessary for sufficient illumination, a light pattern with many areas of varying illumination intensity is created at a greater distance. Conventional flashlights, which however have a much higher power consumption due to the use of incandescent lamps, produce a sharply defined spot of light with an even distribution of illumination intensity, which on the one hand enables patterns and structures in the illuminated area to be recognized much better and on the other hand produces a more pleasing, clearly defined image for the user.

It is an object of the present invention to provide a flashlight with light-emitting diodes in which the inhomogeneities of a light pattern generated by it at a greater distance are significantly reduced.

The problem is solved by a flashlight having the features of claim 1.

A flashlight according to the invention has a flashlight body and a lamp head. This lamp head comprises at least two light-emitting diodes and an optical device assigned to each of the light-emitting diodes for bundling the light emitted by the respective light-emitting diode. To achieve a less inhomogeneous light pattern at a greater distance, a tube is arranged between each of the light-emitting diodes and the associated optical device for bundling the light emitted by the respective light-emitting diode. The tubes are designed in such a way that they largely prevent light from one of the light-emitting diodes from penetrating an optical device assigned to another of the light-emitting diodes for bundling the light emitted by the respective light-emitting diode.

The tubes according to the invention prevent scattered light from a light-emitting diode from falling into optical devices for bundling the light emitted by other light-emitting diodes and, after being deflected by these, leading to comparatively dimly lit areas in the light pattern generated by the flashlight at a greater distance. This makes it possible to bundle the light emitted by the light-emitting diodes without simultaneously being impaired by scattered light from neighboring light-emitting diodes, so that at a greater distance

a light pattern with high illuminance but only small inhomogeneities is obtained.

Preferred embodiments and developments of the invention are described in the description, the drawings and the subclaims.

The tubes are preferably designed in such a way that the light emerging from them from the corresponding LEDs falls essentially completely on the corresponding associated optical device for bundling the light emitted by the respective LED. This means that the light entry surface of the imaging device must not be significantly smaller than the opening surface of the tube. This means that the tube acts like an aperture stop, which results in sharply defined areas associated with the LEDs in the light pattern at a greater distance with appropriate focusing. On the one hand, this leads to a greater illuminance in the light pattern in relation to the amount of light emitted by the LEDs, since scattered light is avoided. On the other hand, the sharp demarcation results in a more pleasant and appealing light pattern for the user.

The tubes are preferably made of a non-transparent or translucent material, although it is generally sufficient for the inner or outer surface of the tube to be coated so that it is opaque. The inner surface of the tube is particularly preferably non-reflective.

·

Although the tubes can basically be formed only by partitions and the housing of the lamp head, the interior of at least one of the tubes is rotationally symmetrical. This cross-section of the interior corresponds to the radiation characteristics of the LEDs and also produces a very attractive, circular light pattern. In addition, such tubes are particularly easy to manufacture. In order to be able to concentrate as much of the light emitted by a LED as possible, the optical device associated with this LED for bundling its light is generally larger in area than the associated LED. It is therefore particularly preferred if at least a portion of the interior of the tubes has a truncated cone shape.

Although the tubes should basically only be located between the light-emitting diode and the optical device associated with this light-emitting diode for bundling the light emitted by it and can in particular also be shorter than the distance between the light-emitting diode and the device associated with this light-emitting diode for bundling the light emitted by it, it is preferred that the tubes are held on a base element and that the ends of the tubes facing the light-emitting diodes accommodate at least parts of the light-emitting diodes' luminous bodies. This type of mounting of the tubes achieves several advantages. Firstly, the tubes are particularly easy to assemble, and their position relative to one another can be easily ensured by the arrangement on the base element, so that their alignment with the optical devices for bundling can be carried out for all tubes with just one adjustment process. Secondly, the fact that the ends facing the light-emitting diodes accommodate at least parts of the light-emitting diodes' luminous bodies

The LEDs, which are usually only held in place by their contact pins, can be aligned easily and precisely. This results in particularly good alignment of the LEDs with the optical device for bundling the light emitted by the respective LED, thus achieving high illuminance.

Particularly preferably, one end of at least one tube associated with a light-emitting diode adjoins the optical device associated with this light-emitting diode for bundling the light emitted by this light-emitting diode or an element holding it. In addition to aligning the light-emitting diodes with the corresponding optical devices for bundling the light emitted by the respective light-emitting diodes, this results in a simple adjustment of the distance between light-emitting diodes and optical devices for bundling their light, whereby good focusing of the light emitted by the light-emitting diodes can easily be achieved in predetermined distance ranges. In principle, this effect can also be achieved by appropriate shaping of the base element, for example by molded-on spacers, but at least in the case in which the ends of all tubes are adjacent to the corresponding optical devices for bundling the light emitted by the LEDs, there is the further advantage that stray light due to reflection from the optical devices for bundling the light emitted by the respective LEDs cannot easily fall into the interior of the lamp head between the tubes and be reflected from there, so that undesirable stray light thus created is suppressed.

Preferably, the base element and tubes are formed as one piece, which on the one hand allows for simple and cost-effective production, for example as a plastic injection-molded part, and on the other hand ensures that the tubes are aligned in a way that is particularly stable against interference. The base part is particularly preferably essentially in the form of a light-collecting reflector, which on the one hand results in a very stable mount for the tubes, since they are connected to the base part along their circumference and also in their lengthwise direction. On the other hand, when viewed against the direction of illumination, an attractive image is produced that is familiar from ordinary flashlights.

Preferably, the light-emitting diodes are held on a circuit board which has contact elements for contacting power supply contacts provided in the flashlight base body or batteries or accumulators which can be inserted into the flashlight base body. This results in a particularly simple mounting of the light-emitting diodes, whereby at the same time the current paths can be particularly short.

The contact elements particularly preferably comprise a first ring-shaped contact surface and a second, further essentially ring-shaped or circular contact surface arranged within the first contact surface. This allows secure contact even when the flashlight body and lamp head are at different angular positions, which can occur in particular when the lamp head is screwed onto the flashlight body. In addition, it is also possible to use the contacts of batteries arranged next to one another in the flashlight body as power supply contacts.

When using a circuit board that carries the light-emitting diodes, it is preferred that the base element is arranged on the circuit board, since this results in a compact arrangement of the components and, on the other hand, possible damage to the power supply for the light-emitting diodes due to a relative movement of the base element and the circuit board can easily be avoided.

Although the optical devices for focusing the light emitted by the respective LEDs can in principle be held individually in appropriate holders, it is preferred that the optical devices for focusing the light emitted by the respective LEDs are lenses that are integrated into a front element. The front element can be translucent or opaque in the areas without lenses, which can be achieved by appropriate coatings, but is preferably transparent overall, since it can then be manufactured very easily and inexpensively, for example as a plastic injection molded body. In addition, simple alignment of all LEDs is possible with just one adjustment process, especially when a lamp head with a base element as described above is used.

Although the front element can essentially only be designed in the shape of a disk, in a preferred embodiment it is designed in the shape of a pot, with the tubes and the circuit board with the light-emitting diodes being arranged inside the pot. This results in a unit with all the optical components that is easy to assemble, and in particular in the case where a base element is provided, a unit that is very easy to assemble and has very reliable and simple adjustment can be produced.

For this purpose, the front element and the base element or the circuit board particularly preferably have corresponding guide elements that act as anti-twist devices. This results in very simple assembly, since the alignment of the LEDs, the tubes and the optical devices for bundling the light emitted by the respective LEDs is ensured by the guide elements alone. On the other hand, even during use, no misalignment can occur, e.g. due to shocks or vibrations caused by a relative rotation of the LEDs and the optical devices associated with them for bundling the light emitted by the respective LEDs.

During assembly, the base element can simply be inserted into the pot-shaped front element, whereupon the pot is closed by the circuit board at its edge. The connection between the front element and the circuit board can be made by gluing or, if plastic parts are used, by welding, but it is preferred that the front element and the circuit board are connected to one another at the edge of the pot by a snap connection. This results in particularly simple assembly, and in which no high temperatures, which could damage the circuit board or the LEDs, or harmful solvent vapors contained in adhesives can occur.

The front element with tubes and circuit board is preferably arranged in a sleeve-like head housing, which enables easy assembly of the units. In addition, the sleeve-like head housing can

They serve as mechanical protection for the front element through appropriate choice of material.

In order to enable the flashlight according to the invention to be used even in damp and wet conditions, at least one, particularly preferably circumferential, lamp head seal is preferably provided between the front element and the head housing, which prevents moisture from penetrating between the front element and the head housing.

For this purpose, it is also preferred to provide a seal, particularly preferably a circumferential seal, between the lamp head and the flashlight base body.

To achieve the most uniform illumination possible, the LEDs are preferably arranged on a circle with equal angular distances.

Preferably, three LEDs are provided, as this results in a particularly favorable ratio between the illumination achieved and the low power consumption. This is particularly important because, with the same lighting duration, low power consumption also allows the use of smaller batteries or accumulators and thus lower weight.

A preferred embodiment will now be described by way of example with reference to the drawings.

Fig. 1 is a schematic sectional view through a flashlight

according to a preferred embodiment of the invention,

Fig. 2 is an exploded view of the lamp head of the flashlight in Fig. 1,

Fig. 3 is a plan view of the circuit board in the lamp head in Fig.

2 from the side facing the flashlight body,

Fig. 4 is a plan view of the base element of the lamp head in Fig.

2 from a direction opposite to the direction of illumination and

Fig.5

a perspective view of the base element in Fig. 4.

In Fig. 1, a flashlight according to a preferred embodiment of the invention comprises a flashlight body 10 and a lamp head 12.

The flashlight body 10 is tubular and closed at one end. A battery compartment 14 for holding batteries is formed in the interior. Furthermore, power supply contacts are provided in the flashlight body 10, of which only the power supply contact 16 is visible in Fig. 1. This power supply contact 16 is connected via a switch 18 embedded in the flashlight body 10 in a watertight manner to a contact surface (not shown in the figures) for a pole of a battery that can be inserted into the battery compartment 12.

At its open end, the flashlight body 10 has an external thread 20 which serves to attach the lamp head 12. At the end of the external thread 20, a circumferential lamp head seal 22 is provided which is held in a recess.

The lamp head 12 is composed, as also shown in Fig. 2, of a sleeve-shaped head housing 24, a front element 26, a base element 28 and a circuit board 30 with three white light LEDs, of which only the LEDs 32a and 32b are shown in Fig. 2.

The circuit board 30 is circular, as can be seen in Fig. 3, with the three light-emitting diodes, not visible in the figures, arranged on a circle at equal angular distances from one another. As shown in Fig. 2 for the light-emitting diodes 32a and 32b, the light-emitting diodes have luminous bodies 33a and 33b, respectively, and are held on the circuit board 30 by their contact pins 34a and 34b, respectively. On the rear side facing away from the side carrying the light-emitting diodes, the circuit board has a first ring-shaped contact surface 36 and a second contact surface 38, also ring-shaped, arranged concentrically in the first contact surface 36. These contact surfaces 36 and 38 are connected to the light-emitting diodes via conductor tracks and electronic components not shown in the figures, so that power from batteries inserted in the flashlight base body can be supplied to the light-emitting diodes via the contact surfaces 36 and 38 after contacting the power supply contacts in the flashlight base body 10.

Furthermore, three recesses 40a, 40b and 40c are provided along the circumference of the circuit board 30 at equal angular intervals.

The front element 26 is pot-shaped and made of a transparent material, such as a suitably transparent plastic. Integrated into its front panel 42 are three converging lenses arranged on a circle at equal angular intervals corresponding to the arrangement of the light-emitting diodes, of which only the converging lenses 44a and 44b are visible in Fig. 2. The curvatures of the converging lenses are formed on the inside of the pot, so that the side of the front panel 42 facing outwards is flat.

Near the front panel 42, a circumferential groove 46 for receiving a seal is formed on the side wall of the front element 26.

A shoulder 48 runs along the edge of the pot, offset in the direction of the front panel 42. The edge of the pot is thickened to form a bead 50 that extends into the interior of the pot, with the shoulder 48 extending further into the interior of the pot than the bead 50 and the distance between the shoulder 48 and the bead 50 corresponding to the thickness of the circuit board 30. The inner diameter of the front element 26 in the area of the shoulder 48 and the bead 50 are selected such that the circuit board 30 can be snapped in between the bead 50 and the shoulder 48 with pressure.

On the inner edge of the front element 26, three guide lugs are also provided at equal angular intervals, of which only one guide lug 52 is visible in the figures and which are designed in such a way that they fit into the corresponding recesses 40a, 40b and 40c along the circumference.

ence of the circuit board 30 when it is inserted into the front element 26. The collecting lenses and the guide lugs in the front element 26 and the recesses 40a, 40b and 40c and the light-emitting diodes in or on the circuit board 30 are aligned with one another in such a way that the light-emitting diodes are aligned with the collecting lenses when the guide lugs engage in the recesses of the circuit board.

The base element 28, which is held in the front element 26 by the circuit board 30 snapped into the front element, has a paraboloid-like basic shape and sits on the circuit board 30 with three support legs arranged at equal angular distances, of which only the support legs 54a and 54b are visible in the figures. As can be seen in Figs. 4 and 5, the base element 28 also has three tubes 56a, 56b and 56c arranged on a circle at equal angular distances from one another. The tubes 56a, 56b and 56c and the base element 28 with the support legs are formed in one piece as a plastic injection-molded part made of a non-transparent plastic.

Because the contact line between the base element 28 and the tubes 56a, 56b and 56c also extends in the longitudinal direction of the tubes in accordance with the curvature of the base element 28, the tubes are held in the longitudinal direction on the base element 28.

The tubes 56a, 56b and 56c are essentially identical in design, so that they will be described in more detail below using the example of the tube 56a.

The tube 56a has a cylindrical outer surface (see Fig. 4 and 5) and contains a rotationally symmetrical interior. The interior has a cylindrical section 58 at its end facing the light-emitting diode 32a for receiving the luminous element 33a of the light-emitting diode 32a. This is followed by a widening, frustoconical section 60 of the tube interior. While the inner diameter of the cylindrical section 58 corresponds to the outer diameter of the luminous element 33a of the light-emitting diode 32a, the inner diameter of the tube at the end facing the front panel 42 or the lens 44a is selected to correspond to the diameter of the lens 44a.

The length of the support legs 54a, 54b and 54c is selected such that the LED-side ends of the tubes 56a, 56b and 56c rest on bases 61a, 61b of the LEDs, whereby the light elements 33a, 33b of the LEDs are held in a defined position at the end of the tube. The length of the tubes 56a, 56b and 56c is also selected such that they abut the front panel 42, which ensures that the light elements of the LEDs are at a defined distance from the converging lenses 44a, 44b, with the distance and focal length of the converging lenses being selected, for example, such that the light from the LEDs is focused at a distance of approximately 5 m. On the other hand, a movement of the base element 28 between the front panel 42 and the circuit board 30 snapped into the front element 26 is prevented.

Front element 26 with inserted base element 28 and circuit board 30 form, when the latter is snapped into the front element, an easy-to-handle unit that contains all the lighting components of the

light lamp. Light emitted by the light-emitting diodes (32a, 32b in Fig. 2) is guided by the tubes 56a, 56b and 56c to the corresponding collecting lenses (44a, 44b in Fig. 2) and is bundled by them, without scattered light from one light-emitting diode falling onto a collecting lens associated with another light-emitting diode and being deflected by it.

The sleeve-shaped head housing 24 has a circumferential projection 62 at its front end and three locking lugs arranged at equal angular intervals along the inner surface, of which only the locking lugs 64a and 64b are visible in Fig. 1. The unit comprising the front element 26, base element 28 and circuit board 30 is pushed into the head housing 24, with the front panel 42 abutting the projection 62 and the edge facing away from the front panel 42 being snapped in behind the locking lugs (see Fig. 1). This means that it is held very easily and securely in the head housing 24.

As shown in Fig. 1, a seal 66 is arranged in the groove 46 of the front element 26, which seal prevents moisture from penetrating through the gap between the front plate 42 and the projection 62 into the interior of the lamp head 12 and thus into the flashlight base body 10.

The head housing 24 also has an internal thread 68, with which the head housing 24 or the entire lamp head 12 can be screwed onto the external thread 20 of the flashlight base body 10. The threaded end of the head housing 24 is designed in such a way that the threaded end of the external thread 20 of the flashlight base body 10

The arranged lamp head seal 22 tightly seals the gap between the lamp head 12 and the flashlight base body 10 when the lamp head is screwed on.

List of reference symbols

10 Flashlight body 12 Lamp head 14 Battery compartment 16 Power supply contact 18 Switch 20 External thread 22 Lamp head gasket 24 Head housing 26 Front element 28 Basic element 30 Circuit board 32a, 32b Light-emitting diodes 33a, 33b Luminaires 34a, 34b Contact pins 36 first contact surface 38 second contact surface 40a, 40b, 40c Recesses 42 Windscreen 44a, 44b Converging lenses 46 groove 48 shoulder 50 bead 52 Guide nose 54a, 54b, 54c Support legs 56a, 56b, 56c Tubes 58 cylindrical section of the interior

61a, 61b

64a, 64b

truncated cone-shaped section of the interior

base

head Start

Locking lugs

poetry

inner thread

Claims (18)

1. Flashlight with a flashlight body ( 10 ) and a lamp head ( 12 ) with
at least two light-emitting diodes ( 32 a, 32 b),
one optical device ( 44 a, 44 b) associated with each of the light-emitting diodes ( 32 a, 32 b) for bundling the light emitted by the respective light-emitting diode ( 32 a, 32 b), and
a tube ( 56 a, 56 b, 56 c) arranged between one of the light-emitting diodes ( 32 a, 32 b) and the associated optical device ( 44 a, 44 b) for bundling the light emitted by the respective light-emitting diode,
wherein the tubes ( 56a , 56b , 56c ) are designed such that they each largely prevent light from one of the light-emitting diodes ( 32a , 32b ) from penetrating an optical device ( 44a , 44b ) associated with another of the light-emitting diodes for bundling the light emitted by the respective light-emitting diode ( 32a , 32b ). 2. Flashlight according to claim 1, characterized in that the tubes ( 56 a, 56 b, 56 c) are designed such that the light emerging from them from the corresponding light-emitting diodes ( 32 a, 32 b) falls essentially completely on the corresponding associated optical device ( 44 a, 44 b) for bundling the light emitted by the respective light-emitting diode ( 32 a, 32 b). 3. Flashlight according to claim 1 or 2, characterized in that the interior of at least one of the tubes ( 56 a, 56 b, 56 c) is rotationally symmetrical. 4. Flashlight according to one of the preceding claims, characterized in that the tubes ( 56 a, 56 b, 56 c) are held on a base element ( 28 ) and their ends facing the light-emitting diodes ( 32 a, 32 b) receive at least parts of the luminous body ( 33 a, 33 b) of the light-emitting diodes ( 32 a, 32 b). 5. Flashlight according to claim 4, characterized in that one end of at least one tube ( 56 a, 56 b, 56 c) associated with a light-emitting diode ( 32 a, 32 b) adjoins the optical device ( 44 a, 44 b) associated with this light-emitting diode or an element holding it. 6. Flashlight according to claim 4 or 5, characterized in that the base element ( 28 ) and the tubes ( 56 a, 56 b, 56 c) are formed in one piece. 7. Flashlight according to one of the preceding claims, characterized in that a circuit board ( 30 ) carrying the light-emitting diodes ( 32a , 32b ) is provided, which has contact elements ( 36 , 38 ) for contacting power supply contacts ( 16 ) provided in the flashlight base body ( 10 ) or batteries that can be inserted into the flashlight base body ( 10 ). 8. Flashlight according to claim 7, characterized in that the contact elements ( 36 , 38 ) comprise a first, annular contact surface ( 36 ) and a second, further substantially annular or circular contact surface ( 38 ) arranged within the first contact surface ( 36 ). 9. Flashlight according to claim 7 or 8 in conjunction with one of claims 4 to 6, characterized in that the base element ( 28 ) is arranged on the circuit board ( 30 ). 10. Flashlight according to one of the preceding claims, characterized in that the optical devices ( 44a , 44b ) for bundling the light emitted by the respective light-emitting diode are lenses ( 44a , 44b ) which are integrated into a front element ( 26 ). 11. Flashlight according to claim 10 and one of claims 7 or 8, characterized in that the front element ( 26 ) is pot-shaped and that the tubes ( 56 a, 56 b, 56 c) and the circuit board ( 30 ) with the light-emitting diodes ( 32 a, 32 b) are arranged in the interior of the pot. 12. Flashlight according to claim 11 and one of claims 4 to 6, characterized in that the front element ( 26 ) and the base element ( 28 ) or the circuit board ( 30 ) have corresponding guide elements (40a, 40b, 40c, 52) which act as an anti-twist device. 13. Flashlight according to claim 11 or 12, characterized in that the front element ( 26 ) and the circuit board ( 30 ) are connected to one another at the edge of the pot-like front element by a snap connection ( 64 a, 64 b). 14. Flashlight according to one of claims 11 to 13, characterized in that the front element ( 26 ) with tubes ( 56 a, 56 b, 56 c) and circuit board ( 30 ) are arranged in a sleeve-like head housing ( 24 ). 15. Flashlight according to claim 14, characterized in that at least one, preferably circumferential, lamp head seal ( 22 ) is provided between the front element ( 26 ) and the head housing ( 28 ). 16. Flashlight according to one of the preceding claims, characterized in that a, preferably circumferential, seal is provided between the lamp head ( 12 ) and the flashlight base body ( 10 ). 17. Flashlight according to one of the preceding claims, characterized in that the light-emitting diodes ( 32 a, 32 b) are arranged on a circle with equal angular distances. 18. Flashlight according to one of the preceding claims, characterized in that three light-emitting diodes ( 32 a, 32 b) are provided.