COOKING APPLIANCE LIGHT

Description

[0001] The invention relates to a cooking appliance light that can be installed in a cooking appliance, in particular an oven, a microwave cooking appliance, or a steam cooker, wherein the cooking appliance has a cooking chamber that is delimited by a cooking chamber wall and can be closed with a cooking chamber door, with at least one LED light source that can be fastened in a holder outside the cooking chamber and a light guide rod that extends from the holder along its longitudinal axis into the cooking chamber, wherein the light guide rod is essentially designed as a round rod, wherein the light guide rod has a light input surface into which light from the light source is coupled into the light guide rod, and a light output surface from which at least a portion of the coupled light is coupled out into the cooking chamber, wherein the light guide rod comprises an incorporated, light-directing output structure on its lateral surface,which couples the light into the cooking chamber via the light coupling surface.

[0002] LED-based lighting systems for cooking appliances are sufficiently known in the state of the art, although this cannot be documented in printed documents. The particularly temperature-sensitive LED lights must be adequately protected in cooking appliances, especially in ovens where high temperatures can be generated. Therefore, the LED light source is usually located outside the actual cooking chamber. The cooking chamber wall then includes one or more recesses for the passage of a light-conducting rod.

[0003] Increasing importance is being placed on designing cooking appliance lights in such a way that the cooking chamber is illuminated as evenly as possible and the user can, in particular, view the food being cooked during the cooking process.

[0004] Not only the arrangement of the individual components of the lighting system, but also the direction of the light through a predetermined light coupling determine the quality of the illumination of the cooking chamber.

[0005] It is known, for example, from DE10 2011 087 811 A1 to arrange a lighting device for the cooking chamber in the cooking chamber door and to provide the door itself with a reflective layer which reflects the light into the cooking chamber.

[0006] It is also known to arrange reflective surfaces in the cooking chamber outside the area visible from the outside, which radiate the light absorbed by the LED light source into the cooking chamber, according to DE10 2016 010 198 A1.

[0007] DE10 2015 225 992 A1 proposes a light generating device for a cooking appliance, in which, in addition to a light guide provided with structures, a light distribution element is provided, which distributes the light into the muffle of the cooking appliance.

[0008] CN108 980 917 A also describes the arrangement of a light guide with an LED light source for a furnace in a mounting housing specially flanged to the open muffle, which is provided with a heat-resistant cover towards the furnace muffle.

[0009] However, these arrangements require significant manufacturing effort, as, for example, the reflective layer must be applied separately or a separate housing must be manufactured and assembled. The materials used for this, as well as the design itself, represent an additional cost factor.

[0010] DE10 2012 223 678 A1 shows a lighting device for a cooking appliance in which the light guide has an integrated structure for directing the light. AT511 476 B1 also discloses a similar device with a structured light guide. US 2002 / 008969 A1 also shows a light guide, here in cuboid form, with integrated structures intended to direct the emitted light.

[0011] The structuring of optical fibers or optical fibers in general, as well as their optical effect, is described in the publications US 6 367 941 B2 and US 5 432 876 A.

[0012] The object of the invention is to provide an improved cooking appliance light which counteracts the above-mentioned disadvantages.

[0013] The invention solves the problem by a cooking appliance light having the features of claim 1, in particular with its characterizing features, according to which the light guide rod has a beveled end region at its end opposite the light coupling surface, which forms a positioning device with the aid of which the light guide rod itself and thus the light coupling surface can be aligned with the interior of the cooking appliance.

[0014] Such a positioning device makes it considerably easier to position the light guide rod precisely in the cooking chamber, with the light output surface facing the cooking chamber. Even when replacing a damaged light guide rod, alignment can be performed easily.

[0015] In a preferred embodiment, the light guide rod of the lighting device is made of glass. Particularly suitable types of glass include soda-lime glass or borosilicate glass. Glass is particularly suitable due to its high temperature resistance.

[0016] An advantage is that the inventive decoupling structure, such as a satin finish, can be easily incorporated into the glass material. This creates a device that provides full illumination even at very high temperatures, consistently and without interference. Even the pyrolysis process used as a cleaning step in many oven models can be carried out without any problems with this design, without causing damage to the light guide rod.

[0017] The positioning device is formed by a bevel on the light guide rod at its free end facing away from the light coupling surface. The bevel of the light guide rod at its free end creates an inclined surface that ends in a slightly rounded tip. The tip can serve as a positioning aid by being aligned to a specific counterpoint in the cooking chamber. This could, for example, be a mark on the cooking chamber wall towards which the tip is aligned. It can also rest in a counterpart when the light guide rod is inserted and positioned, so that the tip of the light guide rod is held. In this way, only one position for the light guide rod is possible and the coupling-out structure is optimally aligned to emit the light as intended.

[0018] Ultimately, the bevel can be manufactured cost-effectively. A light guide rod is cut to length during production anyway. This cut can also be made at an angle greater or less than 90° to the longitudinal axis of the light guide rod, creating a beveled end section. By choosing a suitable angle—preferably 42°—the resulting beveled surface can serve as a reflective surface and ensure the total reflection of the residual light into the cooking chamber, which represents another particular advantage of the inventive design of the cooking appliance light.

[0019] Particularly advantageous is an outcoupling structure formed in the cooking appliance light according to the invention by a satin finish on the glass surface, which extends over at least part of the lateral surface. An outcoupling structure in the form of a satin finish or, alternatively, an acid-etched finish on the glass surface causes the light to diffusely emerge from the light guide rod at the areas treated in this way.

[0020] The use of such an output coupling structure is advantageous. It can be adapted to a wide variety of conditions. For example, the output coupling structure can be adapted to the arrangement of the light guide rod in the cooking chamber.

[0021] If the light guide rod is to be installed in a corner, for example, the satin finish can be applied to the side facing the cooking chamber, for example, at a 90° angle. The satin-finished surface of the light guide rod facing the cooking chamber then emits the light diffusely and glare-free into the cooking chamber.

[0022] It is also possible to have a satin finish on the light guide rod over the entire 360° surface if this is advantageous for the arrangement in the cooking chamber.

[0023] For the uniform illumination of the cooking chamber, it can be particularly advantageous in the cooking appliance light according to the invention if the outcoupling structure continuously widens starting from the light coupling area, so that it is essentially wedge-shaped over the length of the light guide rod. In this way, in the part of the light guide rod close to the light coupling area, initially only a small portion of the circumference of the light guide rod is satin-finished, while the satin finish becomes increasingly wider over its length. Such a wedge-shaped design promotes the radiation of the residual light over the length of the light guide rod. The light distribution and thus the illumination of the cooking chamber thus appear more uniform to the observer.

[0024] A further advantageous embodiment of the invention is characterized in that the coupling-out structure consists of a plurality of dome-shaped elements formed by wedge-shaped incisions aligned parallel to one another in the light guide rod. The incorporation of incisions parallel and perpendicular to the longitudinal axis of the light guide rod represents a further advantageous possibility for achieving high-quality and uniform light emission via the light guide rod by incorporating a light-directing structure. The incisions are wedge-shaped in the light guide rod, so that dome-shaped elements from the original round shape of the light guide rod remain between the incisions.

[0025] To ensure the best possible residual light distribution, the distances between the individual cutouts become increasingly narrower over the length of the light guide rod, as seen from the light coupling surface, and at the same time the depth of the cutouts increases.

[0026] Further advantages and a better understanding of the invention will become apparent from the description of exemplary embodiments. They show: Fig. 1 a perspective view of a first embodiment of the cooking appliance light according to the invention; Fig. 2 a first possible embodiment of the coupling-out structure on a rod-shaped light guide rod of the cooking appliance light according to the invention. Fig. 1 ; Fig. 3 a second possible embodiment of the coupling-out structure on a rod-shaped light guide rod of the cooking appliance light according to the invention. Fig. 1 ; Fig. 4 a third possible embodiment of the coupling-out structure on a rod-shaped light guide rod of the cooking appliance light according to the invention. Fig. 1 ; Fig. 5 a perspective view of a second embodiment of the cooking appliance light according to the invention;

[0027] In the figures, a cooking appliance light - also referred to simply as light in the following description - is provided with the reference number 10 or 30.

[0028] A first embodiment of the cooking appliance light according to the invention is shown in Fig. 1 It is designated by reference number 10. The cooking appliance light 10 comprises a mounting plate 11, with which it can be mounted in a cooking appliance. The mounting plate 11 has two holding arms 12, which support a holding tray 13 between them, which holds a heat sink 14, as well as a circuit board (not shown in detail) with an LED arranged thereon. The heat sink 14 serves to dissipate the operating heat of the LED.

[0029] On the side facing the mounting plate 11, the retaining shell 13 forms a receptacle 15. This is Fig. 1 circularly shaped according to the outer contour of the light guide rod 16. A light guide rod or light guide 16 can be inserted into the receptacle 15. This is made of solid material. Temperature-resistant plastics or, preferably, glass are suitable.

[0030] Glass—especially borosilicate glass or soda-lime glass—is particularly well-suited for use in cooking appliances where high temperatures are sometimes generated. This ensures that the sections of the light guide rod 16 that extend into the cooking chamber are durable and efficient, even when very high temperatures are used, for example, during pyrolysis cleaning processes.

[0031] The side of the light guide rod 16 facing the LED and the circuit board, with which it is inserted into the receptacle 15, forms a light coupling surface 17. The LED arranged on a circuit board on the holding shell 13 radiates its light via this surface into the light guide rod 16. A closing collar of the holding shell and / or holding elements (e.g., locking elements) not shown in detail prevent unwanted light from escaping at this point.

[0032] The light guide rod 16 extends from the holder 15 and the mounting plate 11 along its longitudinal axis L into the cooking chamber. It can extend partially or completely into the cooking chamber. Light guide rods made of glass, in particular, are resistant to high temperatures and can also be arranged in the cooking chamber itself.

[0033] The light guide rod 16 is designed as a round rod. It has a peripheral surface 19. On this peripheral surface 19, an outcoupling structure 21 is incorporated into the light guide rod 16 in the axial direction. In the present example, this simultaneously forms the light outcoupling surface 18, through which the light is coupled into the cooking chamber.

[0034] In Fig. 2 This coupling-out structure 21 is shown hatched for clarity. It can be, for example, a satin-finished or acid-matted surface. According to the invention, the coupling-out structure 21 is formed in the light guide rod 16 by structuring the surface of the guide rod material itself. The satin-finished surface, for example, diffuses the light coupled into the light guide 16 into the cooking chamber. This is shown in Fig. 1 indicated schematically by arrows.

[0035] Reflective coatings, which on the one hand are complex to apply and on the other hand could be damaged by chipping or the like even at high temperatures, are not required in the lighting device 10 according to the invention.

[0036] The respective surface of a light guide rod can be structured according to customer requirements or requirements to form an output structure 21. The light guidance can be influenced by the selected structure, its orientation, and its extension on the light guide rod.

[0037] This shows Fig. 2 a rod-shaped light guide 16 with a satin finish extending over almost the entire length of the light guide rod 16, encompassing approximately one-quarter, i.e., 90°, of the outer surface 19 of the light guide rod 16. A light guide rod designed in this way is suitable, for example, for placement in a corner, i.e., a joint area between two sheets of the oven muffle. The satin-finished surface of the light guide rod 16 would then be directed toward the cooking chamber to create uniform illumination.

[0038] Fig. 3 shows a further variant of the first embodiment of the invention, in which only the lower free end 22 of the light guide rod 16, facing away from the light coupling surface 17, has a satin finish. Such an embodiment is suitable, for example, for an arrangement in conjunction with a reflector (not shown). The satin-finished area would then be aligned toward an additionally reflective surface of a reflector in order to create a desired lighting situation in the cooking chamber.

[0039] Fig. 4 12 shows a third advantageous variant in which the coupling-out structure 21 extends wedge-shaped along the longitudinal axis L of the light guide 16. Such a coupling-out structure 21 is particularly advantageous for achieving the most uniform possible radiation of the coupled-in light.

[0040] The lighting device according to the invention is particularly advantageous with the Figuren 1 bis 4 shown bevel 23 of the light guide rod 16. The free end 22 of the light guide rod 16 is not cut perpendicular to the longitudinal axis L of the light guide rod 16, but obliquely thereto.

[0041] The bevel 23, with its polished surface, forms a reflection surface 24, which ensures that the residual light present in the light guide rod 16 in the area of ​​the free end 22 is still completely radiated into the cooking chamber.

[0042] The bevel 23 simultaneously forms a rounded tip 25 in the area of ​​the free end 22, which serves as a positioning device. The tip 25 can be aligned with a counterpoint, such as a marking. This allows the alignment of the light guide rod 16 in the cooking chamber to be precisely determined. At the same time, the output coupling structure 21 and thus the light output surface 18 of the light guide rod 16 are also precisely aligned toward the cooking chamber.

[0043] Fig. 5 shows a second embodiment of the cooking appliance light according to the invention. This is designated by the reference number 30. Just as Fig. 1 As is known from the first embodiment, the cooking appliance light 30 comprises a mounting plate 31 with holding arms 32 and a holding shell 33. The holding shell 33 carries a heat sink 34, which serves to cool the circuit board (not shown in detail) of the cooking appliance light 30 with the LED arranged thereon.

[0044] The light guide rod 36 shown in this second embodiment is held with its one end, which forms the light coupling surface 37, in a receptacle 35, analogous to the fastening of the light guide rod 16 in the receptacle 15. The light guide rod 36 is also a round rod made of solid material (preferably glass) with a substantially circular cross-section.

[0045] The light guide rod 36 extends from the holder 35 and mounting plate 31 along its longitudinal axis L into the cooking chamber. It can extend partially or completely into the cooking chamber.

[0046] The light guide rod, designed as a round rod, has a lateral surface 39. On this lateral surface 39, an outcoupling structure 41 is also incorporated into the light guide rod 36 in the axial direction. The outcoupling structure 41 comprises a plurality of notches 40 incorporated into the glass rod. All notches 40 are aligned parallel to one another. The notches 40 are perpendicular to the longitudinal axis L of the light guide rod 36. Starting from the light coupling surface 37, the notches 40 initially have only a small depth, which increases progressively toward the free end 42 of the light guide rod 36.

[0047] By incorporating the incisions 40, dome-shaped elements 46 remain. The light coupled into the light guide rod 36 at the light coupling surface 37 is reflected several times in the dome-shaped elements 46 formed by the incisions 40 and coupled out of the light guide rod into the cooking chamber via the light coupling surface 38 opposite the dome-shaped elements 46.

[0048] Like the first embodiment, the second embodiment of the invention also has a bevel 43 at the free end 42 of the light guide rod 36. The bevel 43, with its polished surface, also forms a reflection surface 44, which ensures the complete radiation of the remaining light present in the region of the free end 42 into the cooking chamber.

[0049] The bevel 43 forms a rounded tip 45 in the area of ​​the free end 42, which serves as a positioning device. In this embodiment, the tip 45 can also be aligned with a counterpoint, such as a marking. This allows the alignment of the light guide rod 36 in the cooking chamber to be precisely determined. The tip 45 forms the end point of the light output surface 38 at the free end 42 of the light guide rod 36. The bevel is thus optimally aligned to radiate the residual light present in the end area of ​​the light guide rod 36. List of reference symbols

[0050] 10 Cooking appliance light 11 Mounting plate 12 Supporting arms 13 Supporting tray 14 Heat sink 15 Mounting bracket 16 Light guide rod 17 Light coupling surface 18 Light extraction surface 19 Shell surface 21 Extraction structure 22 Free end 23 Bevel 24 Reflection surface 25 Positioning device 30 Cooking appliance light 31 Mounting plate 32 Supporting arms 33 Supporting tray 34 Heat sink 35 Mounting bracket 36 Light guide rod 37 Light coupling surface 38 Light extraction surface 39 Shell surface 40 Notch 41 Extraction structure 42 Free end 43 Bevel 44 Reflection surface 45 Positioning device 46 Dome-shaped elements

Claims

1. Cooking appliance light (10, 30) which can be installed in a cooking appliance, in particular an oven, a microwave cooking appliance or a steam cooker, wherein the cooking appliance has a cooking chamber which is defined by a cooking chamber wall and can be closed off with a cooking chamber door, having at least one LED light source which can be mounted outside the cooking chamber in a bracket (13, 33) and a light guide rod (16, 36) which extends out from the bracket (13, 33) along its longitudinal axis into the cooking chamber, wherein the light guide rod (16, 36) is substantially formed as a round rod, wherein the light guide rod (16, 36) has a light coupling surface (17, 37) in which light from the light source is coupled into the light guide rod (16, 36), and a light outcoupling surface (18, 38), from which at least one part of the coupled light is outcoupled into the cooking chamber, wherein the light guide rod (16, 36) comprises an incorporated, light-directing outcoupling structure (21, 41) on its lateral surface, which outcoupling structure outcouples the light via the light outcoupling surface (18, 38) into the cooking chamber. characterised in that the light guide rod (16, 36) has a bevelled end region (22, 23, 42, 43) on its end opposite the light coupling surface (17, 37), which end region forms a positioning device (25, 45), with the help of which the light guide rod (16, 36) and thus the light outcoupling surface (18, 38) can be oriented towards the cooking chamber.

2. Cooking appliance light (10, 30) according to claim 1, characterised in that the light guide rod (16, 36) is made of glass.

3. Cooking appliance light (10) according to one of the preceding claims, characterised in that the outcoupling structure (21) is formed by an at least partial satin finishing of the lateral surface (19) of the light guide rod (16).

4. Cooking appliance light (10) according to claim 3, characterised in that the outcoupling structure (21) extends across 90° of the lateral surface (19) of the light guide rod (16).

5. Cooking appliance light (10) according to claim 4, characterised in that the outcoupling structure (21) continuously spreads outwards from the light coupling surface (17) such that it is formed substantially wedge-shaped across the length of the light guide rod (16).

6. Cooking appliance light (30) according to one of claims 1 or 2, characterised in that the outcoupling structure (41) consists of a plurality of domed elements (46) which are formed by domed incisions (40) in the light guide rod (36) aligned parallel to one another.

7. Cooking appliance light (30) according to claim 6, characterised in that the distances between the incisions (40), starting from the light coupling surface (37), become continuously narrower across the length of the light guide rod (36), and the depth of the incisions (40) increases in each case.