Household appliance light

Abstract

A household appliance light, in particular a light for cooking devices like ovens, microwaves or steam cookers, the household appliance light including a LED configured as an illuminant; a light housing configured to be arranged at a wall of the household appliance; a light exit opening arranged in the light housing which is enclosed by a light permeable cover; a spacer element which is arranged between the LED and the light exit opening and which is arranged in front of a light outlet plane of the LED; and a reflection device which conducts light emitted by the LED to the cover, wherein the spacer element is a light conductor that is made from one uniform material, wherein the reflection device is a reflector which defines a reflector cavity, and wherein the light conductor is run into the reflector cavity.

Claims

1. A household cooking appliance light, comprising: a LED configured as an illuminant; a light housing that is configured to be arranged at a wall of the household cooking appliance; a light exit opening that is arranged in the light housing and closed by a light permeable cover; a spacer element that is arranged between the LED and the light exit opening and that is arranged in front of a light outlet plane of the LED; and a reflection device that conducts light emitted by the LED to the cover, wherein the spacer element is a light conductor that is made from one uniform material, wherein the reflection device is a reflector that defines a reflector cavity, wherein the light conductor is run into the reflector cavity, wherein an entire light exit surface of the light conductor is inclined with a uniform inclination relative to a center axis of the light conductor adjacent to the light exit surface so that a cone axis of a light cone exiting from the light exit surface is also inclined relative to the center axis of the light conductor adjacent to the light exit surface, wherein a scatter radiation exits from a light conductor and the reflector directs the scatter radiation essentially in a direction towards the cover.

2. The household appliance light according to claim 1, wherein the reflector includes a first track shaped reflection surface and a second track shaped reflection surface that originate from an apex axis, and wherein the apex axis is arranged proximal to a light entry surface of the light conductor.

3. The household appliance light according to claim 2, wherein the first track shaped reflection surface is cambered about a camber axis that is parallel to the apex axis.

4. The household appliance light according to claim 3, wherein the first track shaped reflection surface is run into a portion of the light conductor that is proximal to the light entry surface.

5. The household appliance light according to claim 2, wherein the light conductor is laterally offset from the apex axis of the first track shaped reflection surface and the second track shaped reflection surface.

6. The household appliance light according to claim 5, wherein a light exit surface of the light conductor is inclined relative to a center axis of the light conductor so that a cone axis of a light cone exiting from the light exit surface is also inclined relative to the center axis of the light conductor, and wherein the light exit surface of the light conductor is sloped downward in a direction towards the lateral offset.

7. The household appliance light according to claim 6, wherein wherein the first track shaped reflection surface is cambered about a camber axis that is parallel to the apex axis, wherein the second track shaped reflection surface is not cambered and runs to a transition portion of the light exit conductor surface and a light conductor enveloping surface, wherein the transition portion proximal to the light entry surface, and wherein an inclination of the second track shaped reflection surface with respect to the cone axis of the light cone exiting from the light exit surface renders the second reflection surface substantially ineffective.

8. The household appliance light according to claim 1, wherein the reflector and a penetration depth of the light conductor into the reflector cavity are adapted to each other so that the reflector reflects only a scatter radiation exiting from the light conductor, but not a direct radiation exiting from the light exit surface.

9. The household appliance light according to claim 1, wherein the center axis of the light conductor is straight and not cambered along an entire length of the light conductor.

10. A household cooking appliance light, comprising: a LED configured as an illuminant; light housing that is configured to be arranged at a wall of the household cooking appliance; a light exit opening that is arranged in the light housing and closed by a light permeable cover; a spacer element that is arranged between the LED and the light exit opening and that is arranged in front of a light outlet plane of the LED; and a reflection device that conducts light emitted by the LED to the cover, wherein the spacer element is a light conductor that is made from one uniform material, wherein the reflection device is a reflector that defines a reflector cavity, wherein the light conductor is run into the reflector cavity, wherein a light exit surface of the light conductor is inclined relative to a center axis of the light conductor so that a cone axis of a light cone exiting from the light exit surface is also inclined relative to the center axis of the light conductor, wherein a scatter radiation exits from a light conductor and the reflector directs the scatter radiation essentially in a direction towards the cover, and wherein the reflector directs the scatter radiation substantially in a direction towards a cone axis of a light cone exiting from the light exit surface of the light conductor.

11. A household cooking appliance light, comprising: a LED configured as an illuminant; a light housing that is configured to be arranged at a wall of the household cooking appliance; a light exit opening that is arranged in the light housing and closed by a light permeable cover; a spacer element that is arranged between the LED and the light exit opening and that is arranged in front of a light outlet plane of the LED; and a reflection device that conducts light emitted by the LED to the cover, wherein the spacer element is a light conductor that is made from one uniform material, wherein the reflection device is a reflector that defines a reflector cavity, and wherein the light conductor is run into the reflector cavity, wherein the reflector includes a first track shaped reflection surface and a second track shaped reflection surface that originate from an apex axis, wherein the apex axis is arranged proximal to a light entry surface of the light conductor, wherein the first track shaped reflection surface is cambered about a camber axis that is parallel to the apex axis, wherein the first track shaped reflection surface is run into a portion of the light conductor that is proximal to the light entry surface, wherein the portion of the light conductor that proximal to the light entry surface is arranged below a plane where boundary beams of a beam cone defined by the radiation angle of the LED intersect boundary surfaces of the light conductor enveloping surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages and a better comprehension of the invention can be derived from the subsequent description of an embodiment with reference to drawing figures, wherein:

(2) FIG. 1 illustrates an exploded view of a light according to the invention;

(3) FIG. 2 illustrates a sectional view of the light according to FIG. 1;

(4) FIG. 3 illustrates a schematic view of radiation characteristics of the light according to FIG. 1 without the reflector according to the invention in a sectional view;

(5) FIG. 4 illustrates a schematic view of radiation characteristics of the light according to FIG. 1 using the reflector according to the invention;

(6) FIG. 5 illustrates an oven with the household appliance light according to the invention in a perspective view;

(7) FIG. 6 illustrates the oven according to FIG. 5 in a front view;

(8) FIG. 7 illustrates a sectional view of the oven according to sectional B-B in FIG. 6; and

(9) FIG. 8 illustrates a blown up detail according to the detail circle VII in FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

(10) In the drawing figures a household appliance light simply referred as a light is designated overall with the reference numeral 10. The household appliance light according to FIG. 1 includes a cooling element 11 on which a circuit board 12 is arranged with an applied LED 13 (FIG. 2)

(11) Additionally a light housing 14 made from an electrically and thermally insulating material like e.g. plastic or ceramic is arranged on the cooling element wherein a light conductor 15 is arranged in the light housing. In the instant embodiment this is a rod shaped light conductor made from glass. The light conductor includes a light entry surface 16 that is arranged proximal to the LED (FIG. 2) and a light exit surface 17 that is arranged remote from the LED. The light exit surface 17 is inclined relative to a center axis of the light conductor 15. With respect to the circuit board 12 the center axis is sloped downward towards the circuit board 12. Furthermore the light exit surface is configured flat.

(12) The light housing 14 includes engagement recesses 18 which facilitate fixing a reflector 20 including an interlocking spring at the light housing 14. The reflector 20 in turn forms a light outlet opening of the light 10 that is not described in more detail wherein the light exit opening is closed by a light permeable cover element 21, a glass pane 22 in the embodiment. Last not least the reflector 20 includes an interlocking element R by which it is fixed in a cut out of a household appliance wall.

(13) In the embodiment the light includes a connection conductors 23 which contact conductor paths of the circuit board 12 with their first ends which is not illustrated and wherein ends of the connection conductors that are oriented away from the circuit board 12 include a plug connector 24 for connecting with a power supply.

(14) FIG. 2 illustrates the light 10 illustrated in FIG. 1 in a sectional view. It can be derived from this sectional view that the reflector 20 forms a first reflection surface 25 and a second reflection surface 26. The reflection surfaces 25/26 form the reflector cavity 29 together with the reflector side walls 27 and start from a common apex axis 28. The reflection surfaces 25, 26 are configured track shaped wherein the first reflection surface 25 is cambered about a camber axis (not illustrated). The camber axis of the first reflection surface 25 is arranged parallel to the apex axis 28. The second reflection surface 26 forms a slanted surface that starts at the apex axis 28. The apex axis 28 is arranged on the light center axis LM which extends through the center of the light housing base surface and through the center of the cover element 21.

(15) The light conductor 15 extends into the reflector cavity 29 and is arranged with its longitudinal axis LA laterally offset from the light center axis LM. The light exit surface is oriented downward towards the circuit board 12 in the offset direction and configured flat. With respect to the reflection surfaces 25 and 26 the light conductor 15 is offset away from the first cambered reflection surface 25 in a direction towards the second reflection surface 26.

(16) Due to this offset and due to the camber of the first reflection surface 25 and due to the configuration of the second reflection surfaces 26 as a slanted surface the first reflection surface 25 impacts the light conductor 15 proximal to the light entry surface. The second reflection surfaces 26, however, intersects the light conductor 25 remote from the light entry surface. Ideally the lowest point of the light exit surface inclined towards the circuit board 12 is arranged in a plane defined by the second reflection surface 26. This special configuration, the asymmetrical reflector 20 with its first cambered reflection surfaces 25 and its second reflection surfaces 26 configured as a slanted surface, the lateral offset of the light conductor 15 from the light center axis LM and the inclined light exit surface 16 causes special radiation characteristics of the household appliance light 10 which are described infra.

(17) FIG. 3 illustrates a representation similar to FIG. 2 wherein the reflector 20 and the cover glass 22 were omitted in order to illustrate the features that will be described infra. The dashed dotted lines illustrated in FIG. 3 symbolize exemplary light beams which are emitted by the LED 13. Initially light beams are illustrated that are designated by D in FIG. 3 and which exit the light exit surface 17 and are designated as so called direct light. This direct light D exits the light exit surface 17 at a particular radiation angle which forms an opening angle of the light cone exiting the light exit surface 17.

(18) Furthermore exemplary light beams S are illustrated which are reflected at the light exit surface 17 due to their angle of incidence, reflected back into the light conductor 15 and which exit from the enveloping surface of the light conductor 15. The light beams designated with S represent the so called scatter light. FIG. 3 illustrates that the scatter light S is reflected back into the direction of the light housing 14 instead of being reflected in a direction of the non-illustrated glass pane 22 that covers the light exit opening of the light 10. Thus, the light beams S are not available to illuminate the interior of the household appliance and can be designated as lost radiation.

(19) It is also evident from FIG. 3 that the cone axis K of the light cone exiting the light conductor 15 and drawn with dots is tilted in the inclination direction due to the inclination of the light exit surface 17 from vertical. Consequently the light exiting the light conductor 15 is substantially oriented away from the light center axis LM or the light conductor longitudinal axis LA.

(20) FIG. 4 substantially corresponds to FIG. 2 wherein also here exemplary dashed dotted lines are drawn which represent light beams exiting the LED 13. The effect of the reflector is clearly evident from FIG. 4.

(21) As can be derived from FIG. 4 the scatter beams S are received by the first cambered reflection surface 25 and reflected in a direction towards the cover element 21 and thus in a direction towards the light exit opening of the light 10. The camber of the reflection surface is sized so that it reflects the scatter light in the offset direction of the light conductor 15, thus essentially in a direction towards the cone axis K. Thus, the first reflection surface 25 only absorbs the scatter light for reflection, the direct light D exiting from the light conductor 15 does not impact the first reflection surface 25 due to the arrangement of the light conductor 15 within the reflection space 29.

(22) The second reflection surface 26 is without function due to its location and its inclination towards the light conductor 15 and thus does not reflect any light. This is relevant for the overall radiation characteristics of the light 10 since the second reflection surface 26 in case it performs a reflecting function reflects the light towards the cone axis K.

(23) As evident from FIG. 4 the offset of the light conductor 15 relative to the light center axis LM has the effect that the enveloping surface oriented towards the first reflection surface 25 is maximized and thus the utilization of the scatter light S in view of the desired reflection direction towards the cone axis K is optimized. The light exiting the light exit opening of the household appliance light 10 or the cover element 21 forms a beam bundle which is also tilted overall in an offset direction of the light conductor 15 and thus has an inclination.

(24) When the light according to the invention is installed in a household appliance, in particular a cooking device so that the first reflection surface 25 is oriented away from and opening of the interior space so that the reflection surface orients the scatter light beams S into the interior of the household appliance so that also the cone axis K of the light beam exiting the light exit surface 17 is oriented into the household appliance interior a blinding of a user is effectively prevented.

(25) In order to further optimize the light yield of the household appliance light 10 the attachment arms 30 which engage light conductor grooves 31 and which keep the light conductor 15 in the light housing 14 are arranged in a portion of the light conductor 15 where no light beams impact due to the provided LED radiation emission angle. Thus, it is provided that the light routing of the light conductor 15 is not influenced in a disadvantageous manner.

(26) FIG. 5 illustrates a household appliance configured as an oven 40. The oven includes an outer housing wall 41 and an inner cooking cavity wall 42 which defines a cooking cavity 43. The cooking cavity 43 is accessible through an oven door 44 which is formed from an oven door frame 45 and an oven door glass 46, wherein the oven door glass 46 facilitates a view into the cooking cavity 43. The cooking cavity wall 42 is provided with rails 47 which are arranged at different levels and which support cooking material carriers 48 configured for example as baking sheets. Within cut outs 49 of the cooking cavity wall household appliance lights 10 are mounted whose cooling elements 11 are in contact with outside air for heat dissipation through recesses 50 of the housing wall 41. The oven is illustrated in FIG. 6 in a front view of the oven door 44.

(27) In FIG. 7 the oven 40 is illustrated in a sectional view along the sectional line B-B in FIG. 6. Thus, the cooking material carrier 48 which is supported on rails 47 is visible in tope view. It is also clearly visible that the side walls are configured with two shelves and an insulation material 51 is arranged between the cooking cavity wall 42 and the housing wall 41. The household appliance light 10 according to the invention is arranged in a recess in the insulation material 51, wherein a cooling element 11 of the house hold appliance light 10 is oriented in a direction towards the housing wall 41 and its cover element 21 is oriented in a direction towards the cooking cavity 43. The rear wall 52 of the cooking cavity which defines the cooking cavity in a rearward direction opposite to the oven door 44 is configured with a single shell in the instant embodiment, a double shell configuration however can also be used.

(28) FIG. 8 illustrates an enlarged detail according to the detail circle VII in FIG. 7.

(29) This enlarged detail shows details of the light that is arranged in the cooking cavity wall 42. The first reflection surface 25 as well as the light exit surface 17 are oriented in a direction towards the rear wall 52 of the cooking cavity and reflect the light emitted by the LED 13 into the cooking cavity 43 so that the major portion of the emitted radiation is oriented away from the oven door 44. This way using the direct light D as well as the scatter light S and the radiation characteristics of the household appliance light 10 directed towards the rear wall 52 of the cooking cavity prevent a blinding effect for a user watching the cooking process through the oven door glass 46 while using the emitted light in an optimum manner for illuminating the cooking cavity 43.

(30) Overall the invention provides a household appliance light 10 which has special radiation characteristics due to a combination of light conductor 15, a reflector 20 provided with asymmetrical reflection surfaces 25 and 26 and last not least through an offset of the light conductor 15 relative to the light center axis LM which facilitates a non-blinding illumination of an inner cavity of a household appliance. Additionally the light yield is substantially improved by a use of the scatter radiation S of the light conductor 15 which support the desired radiation characteristics. The light conductor 15 facilitates an offset arrangement of the LED 13 from an interior of the household appliance, in particular when the interior is a cooking cavity. The reflector 20 is furthermore not only used for reflecting the scatter light radiation S but also for reflecting the heat radiation exiting from a cooking cavity. This way the household appliance light 10 can be kept compact so that it is also suitable for installation in side walls of household appliances.

REFERENCE NUMERALS AND DESIGNATIONS

(31) 10 household appliance light 11 cooling element 12 circuit board 13 LED 14 light housing 15 light conductor 16 light entry surface 17 light exit surface 18 engagement recess 19 engagement spring 20 reflector 21 cover element 22 glass pane 23 connection conductor 24 plug connector 25 first reflection surface 26 second reflection surface 27 reflector side wall 28 apex axis 29 reflector cavity 30 attachment side arm 31 light conductor groove 40 oven 41 outer housing wall 42 cooking cavity wall 43 cooking cavity 44 oven door 45 oven door frame 46 oven door glass 47 rail 48 cooking material carrier 49 cut out 50 recess 51 insulation material 52 cooking cavity rear wall K cone axis R interlocking element S scatter light D direct light LM light center axis LA longitudinal axis of 15