Glass-embedded switching device with light halo effect

Abstract

A backlit switching device embedded in glass, comprising a glass plate (1) with a switching device, characterized in that a recess (14) is provided in the glass plate (1) on its front surface (1a), wherein at least parts of a switching device comprising at least one switching element (4) and a decorative film (2) are arranged in the recess (14), wherein the surface of the decorative film is flush with the surface (1a) of the glass plate (1), and wherein at least one optical element (16) is also arranged in the recess (14), through which light from the recess enters the glass plate laterally, is propagated there, and is reflected on the back of the glass plate (1b) towards the front of the glass plate (1a), thus generating a light halo effect around the switching device.

Description

[0001] The invention relates to a backlit, preferably mechanical, switching device embedded in a glass plate. Switching devices with backlit buttons arranged behind glass are known in principle from the prior art.

[0002] DE 10 2016 208 337 A1 describes a backlit capacitive touch switch with an electrically conductive connector arranged between an electrically insulating and largely transparent cover plate and a carrier plate. A light source and an optical element, acting as a diffuser and light guide, are arranged beneath the cover plate.

[0003] DE 10 2009 060 210 A1 also describes a touch switch in which at least one light source is arranged. In one described embodiment, it is possible to backlight or mark the touch area associated with the capacitive sensor element on the cover plate and / or to signal a switching state of the capacitive touch switch.

[0004] EP 2 339 602 A1 describes a switching device with an optical fiber through which light from a light source is guided laterally towards a push-button surface to achieve uniform illumination and an optical effect in the edge region of the push button. The device serves to generate a halo of light around an operating element, with the optical fiber being integrated into a plastic housing. A mechanical switching device embedded in glass with a decorative film is not disclosed therein.

[0005] Backlit switching devices known from the prior art often have a large glass plate as their covering actuation area. A capacitive proximity switch is arranged on the back of this plate, with a sensor surface on the front. The light source is located behind the glass plate, and the light passes through the glass plate towards its front.

[0006] The glass plate often has opaque and translucent areas printed on it to create backlit symbols. In some prior art variations, the transparency of the opaque areas is varied to at least partially compensate for brightness fluctuations caused by the iris effect. In other variations, light-dark gradients or brightness accents are achieved by selecting different levels of transparency, particularly in combination with a suitable geometry of an optical element and / or by utilizing the iris effect. The "iris effect" refers to the decrease in backlight intensity with increasing distance from the point of illumination.

[0007] Such switching devices are usually electrically connected to the capacitive proximity switch and to the electrical consumer via a cable.

[0008] However, such switches have a significant disadvantage: to be operable, the sensor must always be powered. This makes it impossible to completely switch off a device, as at least a certain level of standby power is required to ensure the device can be controlled / activated via the proximity switch.

[0009] However, some technical devices absolutely require that they be completely switchable to eliminate power consumption. In such cases, only a mechanical switch is suitable. However, existing mechanical switches cannot be combined with a glass surface, at least not in the same way as sensor switches located behind a continuous glass plate.

[0010] Furthermore, the intensity of the optical effect achieved using an “iris effect” in the prior art is quite limited and does not allow for backlighting of a switch in the style of a light ambience surrounding the switch or a light halo.

[0011] The object of the invention is to eliminate the disadvantages arising from the prior art. Accordingly, it is preferential to prevent continuous power consumption and, at the same time, to enable a design-wise desired glass operating surface with a light halo. This object is achieved with a switching device according to claim 1. The dependent claims describe preferred embodiments of the invention.

[0012] According to the invention, the embedded switching device presented here has a glass plate, which can be, for example, part of a housing of an electrical device.

[0013] According to the invention, the glass plate has a recess on its front surface in which a preferably mechanical switching device is embedded. The recess can, in principle, be round, rectangular, oval, or any other shape. According to one embodiment, it can have a base that runs parallel, or at least largely parallel, to the front surface of the glass plate. The term "parallel" is to be interpreted broadly in the context of the invention; thus, for the purposes of the invention, the base of the recess is considered to be parallel to the front surface of the glass plate even if it is not flat and, for example, has grooves or indentations. It is considered parallel if the top surface of a film, a film pack, or a flat body placed on the base is aligned parallel to the front surface of the glass plate.The base is also considered parallel to the front surface of the glass plate within the meaning of the invention if, during the production of the recess, a sloping base was initially created, but this was leveled by, for example, a wedge-shaped insert. An embodiment of the recess without a base is also part of the invention.

[0014] According to one embodiment, the recess is machined into the glass plate using a suitable manufacturing process, preferably a laser, and preferably has manufacturing tolerances of 50 µm. Preferably, the recess is created using a 532 nm laser. This results in particularly good processability and accuracy. This is necessary to ensure a small gap between the decorative film and the glass plate.

[0015] According to the invention, a preferably mechanical switching device is arranged in the recess. It is not necessarily the case that the entire switching device has to be arranged in the recess, but at least components thereof.

[0016] The back of the glass plate may have an access point to the recess on the front. The switching device located in the recess can then be electrically connected / wired to, for example, a load via this access point.

[0017] The switching device itself comprises at least one contacting element, one switching element and one decorative film, wherein the surface of the decorative film is flush with the surface of the glass plate.

[0018] Furthermore, an optical element is provided in the recess. This optical element is designed for light diffusion and / or light guidance. Preferably, the optical element is positioned above the switching element (e.g., a snap disc) and even more preferably between the decorative film and the switching element, so that the optical element can be moved by pressure on the decorative film and then presses against the switching element.

[0019] For backlighting and the light halo effect, at least one light source, e.g., an LED, is provided. The at least one light source and the optical element are arranged such that the light rays from the light source penetrate the optical element and are guided and / or scattered by it.

[0020] Preferably, several light sources are arranged to achieve uniform illumination of the optical element. The light sources are preferably oriented so that the light rays can only enter the glass plate via the optical element.

[0021] In one embodiment, at least two LEDs are housed in the recess and arranged along the sides. In another embodiment, four LEDs are evenly distributed within the illuminated area. In yet another embodiment, at least one light source is located behind the glass plate.

[0022] The optical element is preferably spherically shaped on its upper surface which touches the decorative film, in order to replicate the feel of a snap disc when the switching device is actuated.

[0023] Preferably, the optical element has a central contact point on its side facing the switching element, via which it exerts pressure on the switching element, e.g. the snap disc, when the decorative film is pressed.

[0024] The optical element is arranged and designed to direct a portion of the light rays originating from the light source laterally into the glass plate and to illuminate a print, film, or generally opaque or semi-transparent surface applied to the back of the glass plate, thereby creating a "light halo effect".

[0025] Depending on the various, combinable designs, the optical element can be colored. Furthermore, the optical element can have reflective layers on its surfaces. These can, for example, be designed as ornamental patterns, thereby propagating the light beam across the glass plate and / or illuminating the opaque or semi-transparent surface. The inside of the recess can also be designed with similar colored or reflective layers to create a similar light pattern in the glass plate or on the opaque or semi-transparent layer.

[0026] At the same time, the optical element is preferably designed to direct the light towards the decorative film, so that the decorative film is backlit.

[0027] Preferably, the decorative film has both opaque and translucent areas. This allows for the formation of symbols or patterns, which become particularly visible when the decorative film is backlit.

[0028] The glass plate may also be colored or contain optically effective pigments.

[0029] The invention presents a preferably mechanical switch embedded in glass with a light halo effect, which preferably does not require a standby mode in terms of power supply in order to be activatable and also gives the impression of a continuous front glass plate.

[0030] To further enhance this effect, according to a preferred embodiment of the invention, the decorative film has a reflectance or light reflectance in the range of 380 nm to 780 nm that is matched to the glass plate. Light reflectance is defined as the percentage of light radiation in the visible light range (380–780 nm) that is reflected outwards. This results in the optical appearance of the glass surface being similar to, or even identical to, that of the decorative surface.

[0031] Alternatively, or even more preferably, the light transmittance of the decorative film is adapted to the light transmittance of the glass pane. The light transmittance of glazing refers to the percentage of light radiation in the visible light range (380–780 nm) that is transmitted from the outside to the inside.

[0032] Preferably, or alternatively, the light absorption coefficient of the decorative film is adapted to the light absorption coefficient of the glass pane. Light absorption coefficient refers to the proportion of visible light radiation (380–780 nm) that is absorbed by the glazing. Preferably, the spectrum of reflection, transmission, and / or absorption, relative to the wavelengths of visible light, of the decorative film is also adapted to the values ​​for the glass pane.

[0033] A glossy decorative film is preferred. If the glass material has a matte surface, a matte decorative film is also preferred.

[0034] If the glass plate has a color, then preferably the color of the decorative film should also be matched to the glass plate.

[0035] If the glass plate is printed, the decorative film is preferably also printed accordingly. In summary, the preceding characteristics can be described as follows: the optical properties of the decorative film are preferably matched to the optical properties of the glass plate.

[0036] In contrast, the optical properties of the glass and the decorative film can also be deliberately designed to be contrasting in order to create an optical effect.

[0037] According to another embodiment, a printed marking, e.g., a circle or the like, is provided at the edge of the decorative film – i.e., at the transition to the glass pane – to conceal the gap between the glass pane and the decorative film. To enhance the technical effect of the concealment, the marking also stands out from the glass pane in color (e.g., through greater brightness / contrast / signal color).

[0038] According to a preferred embodiment of the invention, the decorative foil has an embossing that enables haptic feedback for finding the position of the button.

[0039] During the switching process, the switching element touches a contacting element.

[0040] A switch foil or a printed circuit board is particularly preferred as the contacting element, but other embodiments of the contacting element, such as FFC (flat flexible cable), FPC (flat printed circuit), conductively coated plastic plate, plates with wire or the like, are also part of the present invention.

[0041] If the contact element is a switch foil, the "tail" of the switch foil is preferably guided through the rear access to the recess in which the switch foil is arranged. The "tail" of the switch foil provides an electrical connection that can be connected to the electrical device to be controlled. In the case of a printed circuit board or other contact elements, analogous electrical connections are used.

[0042] The switching element is preferably arranged above the contacting element. The switching element can be formed by various components. In a particularly preferred embodiment, the switching element is formed by a snap disc which rests on the contacting element, preferably on the switch foil. In another embodiment, a flat switch can also serve as the switching element, and in yet another embodiment, the switching element can be formed by conductive printing on the back of the decorative foil. However, preferred are variants of the switching element that provide haptic feedback to the operator during the switching process, such as the aforementioned snap disc, a simple switch, or a short-stroke push button.

[0043] One or more spacers can be provided between the contact element and the decorative film. Particularly when using a snap disc, a retaining film is also preferably provided to hold the snap disc in position.

[0044] One possible configuration in the recess consists of a switch foil or circuit board, a snap disc mounted on it, which is held by a ring-shaped retaining foil.

[0045] Preferably, the recess (applies to all versions) is designed in a stepped manner, with a first recess, corresponding to the thickness of the decorative film, being formed with adhesive in the front of the glass plate. A second recess is then formed at the bottom of this first recess, with both recesses together forming the opening, which may provide access to the back of the glass plate. The second recess, or the entire opening, may also extend all the way to the back.

[0046] In its assembled state, the aforementioned decorative film is adhered to the first recess by means of adhesive, and is flush with the top surface of the glass plate. "Flush" in the context of the invention means that, in the transition area between the decorative film and the glass plate, the surfaces of the decorative film and the glass plate – viewed in cross-section – lie on the same plane and are offset from each other in height by a maximum of 100 µm, preferably less than 50 µm. List of characters

[0047] Particularly preferred embodiments will now be explained with reference to drawings. These show: • Fig. a preferred embodiment of the invention with a snap disc, • Fig. a second, particularly preferred version with a snap disc. Reference symbol list 1 glass plate 2 decorative foil 3 Contact element 4 switching element 5 glue 6 Access 7 Electrical connection 8 Spacer Dome 9. Holding film 10 In-depth study 11 spacers for fixing the switching element 12 switching element room 13 Ventilation duct 14 recess 15 Bottom of the recess 16 Optical element 17 LED 18 adhesive decorations

[0048] Fig. Figure 1 is a cross-sectional view of the switching device according to the invention, embedded in glass. The glass plate 1 can, for example, be part of a housing of an electrical device, which includes operating elements and, if applicable, a display device.

[0049] A recess 14 is formed in the glass plate 1 by a suitable method, preferably a laser, at a depth necessary for the illustrated assembly, parallel to the top surface 1a of the glass plate 1. A switching device is located in the recess 14, comprising a contact element 3, a switching element 4, and a decorative film 2. In the embodiment shown here, the contact element 3 is designed as a switch film and the switching element 4 as a snap disc.

[0050] The switch film 3, preferably between 120 and 130 µm thick, and more preferably 125 µm thick, is fixed to the base 15 of the recess 14 by means of an adhesive 5, preferably between 120 and 140 µm thick, and more preferably 130 µm thick. The tail of the switch film is connected via an access point 6 to an electrical load to be controlled (not shown here) as an electrical connection 7.

[0051] The snap disc 4 is mounted on the switch film 3 and provides haptic feedback when actuated. The snap disc 4 is fixed laterally by a spacer dome 8 with a height preferably between 120 and 130 µm, and more preferably 125 µm, and by two LEDs 17, and vertically by a retaining film 9 with a height preferably between 90 and 110 µm, and more preferably 100 µm.

[0052] The optical element 16 is arranged above the snap disc 4, and the decorative film 2, preferably with a thickness of 120 to 140 µm, and more preferably 130 µm, is applied over it. The decorative film is flush with the surface of the front side of the glass pane 1a.

[0053] The optical element 16 has a centrally arranged, preferably cylindrical, protrusion with which it contacts the snap disc 4. When the decorative foil 2 is pressed, the optical element 16 is pressed against the snap disc 4 and ultimately triggers a circuit in the switch foil 3. According to the embodiment shown here, which is also applicable to other variants, the optical element 16 has a lateral guide and / or glare-control edge 16a. This prevents light from the LEDs 17 from being directed directly into the glass plate. This ensures that all light must first pass through the optical element before entering the glass plate 1 laterally.

[0054] A large portion of the light propagates upwards into the decorative film 2, but a significant portion also exits the optical element laterally and propagates into the glass plate 1. The optical element directs the light into the glass plate 1 in such a way that the back of the glass plate and any printed material, film, or opaque or semi-transparent surface applied to it are illuminated. This creates the halo effect. This effect is further enhanced if four cross-shaped light sources, such as LEDs, are arranged opposite each other in the recess 2 and preferably even further.

[0055] In this version (also usable for all other versions), the decorative foil 2 has an embossed texture. This provides tactile feedback for the position of the switching device 4. The decorative foil also has translucent and opaque areas. This creates a backlit symbol.

[0056] The spacer 8 and the retaining film 9 above it can together also be called the "snap disc fixation 11". Since the individual components of the fixation 11 are bonded to each other, as well as to the decorative film 2 above it and the switch film 3 / circuit board 3 below it, air cannot escape laterally from the switching element chamber 12 located below the snap disc 4 when it is pressed down. Therefore, a vent channel 13 is provided in the switch film 3 / circuit board, which opens through the adhesive into the access 6 to the back of the glass plate 1b. The air can then escape through this access channel. The snap disc fixation can also be achieved with fewer components than shown here.

[0057] The in Fig. The depicted version largely corresponds to the one shown in Fig.The illustrated version shows a different design. In this version, however, the recess 14 is continuous and has no bottom. The glass plate 1 sits accordingly on the circuit board 3.

Claims

[1] Backlit switching device embedded in glass, comprising a glass plate (1) with a switching device, characterized by , that a recess (14) is embedded in the glass plate (1) on its front side (1a), wherein at least parts of a switching device comprising at least one switching element (4) and a decorative film (2) are arranged in the recess (14), wherein the surface of the decorative film is flush with the surface (1a) of the glass plate (1), and wherein at least one optical element (16) is also arranged in the recess (14), through which light from the recess enters the glass plate laterally, is propagated there, and is reflected on the back of the glass plate (1b) towards the front of the glass plate (1a), thus generating a light halo effect around the switching device. [2] Switching device according to claim 1, characterized by , that the optical element (16) is designed as a milky transparent plastic. [3] Switching device according to claim 1, characterized by , that the optical element (16) has a lateral light-transmitting glare-control edge (16a) through which the light from the optical element (16) is directed laterally into the glass pane (1). [4] Switching device according to one of the preceding claims, characterized by , that a light source (17) is arranged in the recess (14). [5] Switching device according to claim 4, characterized by , that the light source (17) provides monochrome light or white light or, when controlled via an RGB light source, enables color-changing illumination of the optical element (16). [6] Switching device according to claim 1, characterized by , that the optical element (16) has a contact point on the side facing a snap disk (4) which causes the force transmission to the snap disk (4). [7] Switching device according to one of the preceding claims, characterized by, that a contacting element (3) is connected to the back of the glass plate (1b) via an adhesive (5). [8] Switching device according to claim 7, characterized by , that the contacting element (3) with the switching element (12) and a spacer (11) is arranged in the recess (14) via an adhesive (5), wherein the depth of the recess (14) is less than the glass thickness and an access (6) to the front recess (14) is arranged in its rear side (1b). [9] Switching device according to one of the preceding claims, characterized by , that the decorative foil (2) is embedded in a recess (10) by means of an adhesive (18). [10] Switching device according to one of the preceding claims, characterized by , that the decorative film (2) has translucent and opaque areas, forming symbols. [11] Switching device according to one of the preceding claims, characterized by, that a light or brightly colored ring or marking is printed on an edge of the contour of a decorative film (2), which optically conceals the gap between the glass (1) and the decorative film (2). [12] Switching device according to one of the preceding claims, characterized by , that the decorative foil (2) is glossy and has a reflectance in the range of 380 nm to 780 nm that is matched to the glass plate (1) in order to match the optical appearance of the glass surface to the decorative surface. [13] Switching device according to any one of claims 9 to 12, characterized by , that the decorative foil (2) inserted into a recess (10) is at least partially cut laterally by means of an adhesive (18) so that it forms a press or transition fit with the side wall of the recess in the glass in order to optically conceal the transition between the glass (1) and the decorative foil (2). [14] Switching device according to one of the preceding claims, characterized by , that the switching element (4) provides haptic feedback for the actuation.

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