Input arrangement with a cover including a touch-sensitive input surface and a light surface.

Abstract

Input arrangement (10), comprising: a cover (1) which has at least one touch-sensitive operating surface (3) facing an operator (B) and a rear surface (21) facing away from the operator (B), wherein the operating surface (3) includes a backlit illuminating surface (4); a support (2) arranged on the side of the aperture (1) facing away from the operator (B); a light source (8) arranged on the carrier (2), which is arranged to couple light into the aperture (1) via an entrance surface (14) formed in the rear surface (21) facing the light source (8) for backlighting the luminous surface (4), wherein the aperture (1) is designed to be transparent at least in the area between the entrance surface (14) and the luminous surface (4); a translucent film layer structure (6) arranged between the aperture (2) and the light source (8) with a conductive coating to form at least one electrode for a capacitive touch sensor; wherein the entrance surface (14) is formed in or by a recess (23) in the rear surface (21) of the aperture (1), and characterized by the fact that a ventilated cavity volume (12) is formed between the foil layer structure (6) and the entrance surface (14) of the aperture (1), and that the layer thickness (d) of a layer (24) of the aperture (1) varies locally along a linear progression over the entrance surface (14) through its geometric center.

Description

[0001] The invention relates to an input arrangement with a panel, which has at least one or more touch-sensitive operating surfaces facing an operator and a rear surface facing away from the operator, wherein the operating surface each includes a luminous surface to be backlit. To prevent damage to the panel when touched, particularly when actuated, but also to prevent any flexibility of the panel as far as possible and to give the panel a high-quality optical and haptically appealing appearance, the panel, which is usually made of a plastic, typically has a comparatively high total layer thickness of several millimeters, also referred to as the material thickness.This high material thickness is a disadvantage when it comes to backlighting the illuminated surface with the highest possible, and especially uniform, luminance across its entire length. This is because the aperture needs to be illuminated with light from a light source. This involves coupling light from a light source located on the side of the aperture facing away from the operator into the aperture via an entrance surface in a rear surface facing away from the operator, before exiting the illuminated surface formed in the operating surface, opposite the entrance surface. To improve backlighting, the aperture is often "thinned out" overall, which has adverse effects on its haptic properties.For example, in input devices with a comparatively large aperture, especially those with multiple operating surfaces where only a single common detection element is available to detect a change in position, a high overall rigidity of the aperture is necessary to ensure a low-loss force flow from the actuation point to the detection element. Such input devices typically utilize a capacitive touch sensor system with a film layer structure with one or more electrodes formed from a conductive coating, with the film layer structure arranged adjacent to the rear surface of the aperture.

[0002] An input device according to the preamble of claim 1 is known from DE 10 2018 110 033 B3. Input devices of this type are also known from DE 10 2016 123 118 B4, DE 10 2020 120 711 A1, and DE 10 2006 013 937 A1.

[0003] Against this background, there was a need for an input arrangement that is improved in terms of the quality of the touch sensitivity, in particular in terms of the durability of the most homogeneous touch sensitivity possible across the input surface, but also in terms of the quality of the illumination of the luminous surface, such as homogeneity of the light distribution, as well as mechanical stability. This object is achieved by an input arrangement according to claim 1. An equally advantageous use is the subject matter of the use claim. Advantageous embodiments are each the subject matter of the dependent claims. It should be noted that the features individually listed in the claims can be combined with one another in any technologically expedient manner and demonstrate further embodiments of the invention. The description, particularly in conjunction with the figures, further characterizes and specifies the invention.

[0004] The invention relates to an input device comprising a panel. The panel has at least one touch-sensitive operating surface facing the operator and a rear surface facing away from the operator. The operating surface includes a backlit luminous surface. The panel comprises, for example, one or more layers of a thermoplastic. If there are multiple operating surfaces, these are separated, for example, by haptic tactile aids.

[0005] Furthermore, the panel can have an outer protective lacquer layer and / or an opaque lacquer layer provided on the side of the panel facing the operator, wherein the opaque protective lacquer layer represents a symbol or the illuminated surface is designed as a mask in the form of an inverse representation of the symbol. For example, the illuminated surface is flat. Preferably, the operating surface is flat.

[0006] The input arrangement according to the invention further comprises a carrier arranged on the side of the panel facing away from the operator, which carrier serves, for example, to secure the input arrangement to a supporting structure, such as a vehicle body. The carrier is made, for example, from a metal, a metallic alloy, or a thermoplastic. A light source is fixed to the carrier and is arranged to backlight the luminous surface in such a way that light is coupled into the panel via an entrance surface formed in the rear surface facing the light source. According to the invention, the panel is designed to be translucent, at least in the area between the entrance surface and the luminous surface. The light source is arranged, for example, on a circuit board, which in turn is attached to the carrier.

[0007] According to the invention, a translucent film layer structure with a conductive coating is provided between the aperture and the light source to form at least one electrode for a capacitive touch sensor system. For example, by means of the electrode, a detection device forms a measuring capacitance with respect to the earth or vehicle mass or with respect to another electrode, also located on the film layer structure and electrically insulated from the first-mentioned electrode. The measuring capacitance is influenced by the approach of a user's finger to the input surface, at the latest upon touching the input surface, which is detected by the detection device and triggers a change in a switching state upon positive detection of the touch. In a further embodiment, the film layer structure has an array of multiple electrodes for spatially resolved, capacitive touch detection.

[0008] According to the invention, the entrance surface is formed in or by a recess in the rear surface of the diaphragm. A recess is understood to be a depression in the rear surface of the diaphragm. It is preferably provided that the recess reduces the layer thickness of at least one layer of the diaphragm in the region of the recess compared to the region of the layer immediately surrounding the recess, in particular compared to the entire remaining region of the diaphragm. More preferably, the recess ensures a reduction in the total layer thickness of the diaphragm in the region of the diaphragm respectively affected by the recess. Preferably, the total layer thickness of the diaphragm outside the recess is not less than 1 mm, preferably not less than 1.5 mm.

[0009] According to the invention, a ventilated hollow volume is formed between the film layer structure and the entrance surface of the aperture. A ventilated hollow volume is understood to be a hollow volume that is in fluid communication with the air volume surrounding the input arrangement. For example, a fluid-conducting air channel is provided between the hollow volume and the environment of the input arrangement. Preferably, the hollow volume is ventilated via an opening in the film layer structure. Preferably, the opening is provided in a region of the film layer structure that is not covered by the light from the light source directed onto the entrance surface.

[0010] While the recess influences the light entry and in particular increases the light intensity of the light passing through the aperture, the ventilated hollow volume, which is thus open to the environment, ensures that there is no temperature- or air pressure-related relative change in the position of the film layer structure relative to the input surface, which would impair the sensitivity of the touch detection or at least call into question the reproducibility of the triggering of a positive touch detection.

[0011] Preferably, the entry surface is curved, preferably convexly curved, most preferably multiply convexly curved.

[0012] Preferably, the film layer structure spans an additional, ventilated hollow volume on its side facing the light source. This ensures air pressure equalization on both sides and thus prevents air pressure-induced displacement of the film layer structure, which could impair the reproducibility of contact detection.

[0013] According to the invention, the layer thickness of a layer of the aperture, preferably the total layer thickness of the aperture, varies locally along a linear profile across the entrance surface through its geometric center. Even more preferably, this varies continuously.

[0014] In a most preferred embodiment, a layer thickness distribution or total layer thickness distribution of the aperture determined along the course correlates with a luminance distribution of the light source determined along the same course. In other words, along a straight line from an outer edge of the entrance surface through the geometric center of the entrance surface to the opposite edge of the entrance surface, a local increase in the layer thickness or total layer thickness is associated with a local increase in luminance, whereby the luminous surface has a greater uniformity in the local backlighting along a course corresponding to the light propagation in the aperture. For example, the highest luminance and highest layer thickness or highest total layer thickness are located at the geometric center of the entrance surface, while furthermore the locations of the locally lowest luminance and locally lowest layer thickness orTotal layer thickness also coincides from the observer's perspective.

[0015] According to a preferred embodiment, a diaphragm support is further provided, to which the diaphragm is at least supported, preferably fixed. The diaphragm support has a light shaft surrounding the light source and forming the further ventilated hollow volume to guide the light from the light source toward the entrance surface, and the film layer structure is clamped between the diaphragm and the diaphragm support. The diaphragm support is formed, for example, from an opaque material, such as an opaque plastic.

[0016] Preferably, the panel has support bases formed in the rear surface and projecting in the direction of the panel support, by means of which the panel is supported on the panel support.

[0017] According to a preferred embodiment of the input arrangement according to the invention, the panel and the panel support form an actuating part that, when an actuating force acts on the input surface, is movable from a rest position to an actuated position along a travel path, counter to a restoring force generated by a restoring element belonging to the input arrangement, such as a spring element. For example, the travel path is substantially perpendicular to the input surface. The input arrangement further comprises a detection means for detecting a change in the position of the actuating part, such as an electromechanical switch, a capacitive, inductive, resistive, inductive, or piezoelectric force sensor, or the like.

[0018] Preferably, the actuating part is mechanically guided during the movement from the rest position into the actuating position and has, for example, a tongue and groove engagement and / or a lever guide acting between the carrier and the panel carrier or the panel.

[0019] The input arrangement preferably has only a single detection means for detecting a change in position of the actuating part, such as an electromechanical switch, a capacitive, inductive, resistive, inductive or piezoelectric detecting force sensor or the like.

[0020] Preferably, additional ventilated hollow volumes are provided between the panel and the intermediate support.

[0021] The invention further relates to the use of the input arrangement in one of the previously described embodiments in a motor vehicle.

[0022] The invention is explained in more detail with reference to the following figures. These figures are to be understood as examples only and represent preferred embodiments. They show: Fig. 1 is a perspective view of an embodiment of the input arrangement 10 according to the invention; Fig. 2 a sectional view of the Fig. 1 shown embodiment of the input arrangement 10 according to the invention.

[0023] The Fig. 1 and Fig. 2 shows an embodiment of the input arrangement 10 according to the invention. This arrangement comprises a panel 1. The panel 1 has at least one, here several, touch-sensitive operating surfaces 3 facing an operator B and a rear surface 21 facing away from the operator B. Each operating surface 3 contains a luminous surface 4 to be backlit. The panel 1 has a layer 24 made of a transparent thermoplastic. The plurality of operating surfaces 3 are separated by haptic sensing aids 11.

[0024] The panel 1 further comprises an outer protective lacquer layer 21 provided on the side of the panel 1 facing the operator, and an opaque lacquer layer 5, which represents a symbol or forms the illuminated area in the form of an inverse representation of the symbol as a mask, which is provided between the protective lacquer layer 21 and the layer 24 of transparent thermoplastic. Here, the illuminated area 4 and the operating area 3 are each flat.

[0025] The input arrangement 10 according to the invention further comprises a carrier 2 arranged on the side of the panel 1 facing away from the operator B, which carrier 2 serves, for example, to secure the input arrangement 10 to a supporting structure, such as a vehicle body. The carrier 2 is made, for example, of a metal, a metallic alloy, or a thermoplastic. A printed circuit board 18 with a light source 8 is fixed to the carrier 2. The light source 8 is arranged to backlight the luminous surface 4 in such a way that light is coupled into the panel 1 via an entrance surface 14 formed in the rear surface 21 of the panel 1, facing the light source 8. The panel 1 is designed, according to the invention, to be substantially light-transmitting, at least in the region between the entrance surface 14 and the luminous surface 4.

[0026] Furthermore, a translucent film layer structure 6 with a conductive coating is provided between the aperture 1 and the light source 8 to form at least one electrode for a capacitive touch sensor system. Here, a measuring capacitance is formed by means of the electrode from a detection device 20 arranged on the circuit board 18 and electrically connected to the electrode(s) via the flexible conductor 19 with respect to the earth or vehicle mass or with respect to another electrode, also located on the film layer structure 6 and electrically insulated from the first-mentioned electrode. The measuring capacitance is influenced by the approach of a finger of the operator B to the input surface 3, at the latest upon touching the input surface 3, which is detected by the detection device 20 and triggers a change in a switching state upon positive detection of the touch.In a further embodiment, the film layer structure 6 has an array of several selectively controllable electrodes for spatially resolved, capacitive touch detection.

[0027] As in Fig.2, the entrance surface 14 is formed in or by a recess 23 in the rear surface 21 of the diaphragm 1. A recess 23 is understood to be a depression in the rear surface 21 of the diaphragm 1. It is provided that the recess 23 reduces the layer thickness d of at least one layer 24 of the diaphragm 1 in the region of the recess compared to the region of the layer 24 immediately surrounding the recess, in particular compared to the entire remaining region of the diaphragm 1. In the embodiment shown, the recess 23 further ensures a reduction in the total layer thickness D of the diaphragm 1 in the region of the diaphragm 1 affected by the recess 23. Here, the total layer thickness of the diaphragm 2 outside the recess 23 is not less than 5.0 mm.

[0028] According to the invention, a ventilated hollow volume 12 is formed between the film layer structure 6 and the entrance surface 14 of the diaphragm 1. A ventilated hollow volume 12 is understood to be a hollow volume that is in fluid-conducting communication with the air volume surrounding the input arrangement 10. For this purpose, a fluid-conducting air channel is provided between the hollow volume 12 and the surroundings of the input arrangement 10; in particular, the hollow volume 12 is ventilated via an opening 13 in the film layer structure 6. The opening 13 is provided in a region of the film layer structure 6 that is not covered by the light from the light source 8 directed onto the entrance surface 14.

[0029] While the recess 23 influences the light entry and in particular ensures an increased light intensity of the light passing through the aperture 1, the ventilated hollow volume 12, which is thus open to the environment, ensures that there is no temperature- or air pressure-related relative change in the position of the film layer structure 6 relative to the input surface 3, which impairs the sensitivity of the touch detection or at least calls into question the reproducibility of the triggering of a positive touch detection.

[0030] As shown, the entrance surface 14 is curved, particularly in the central region with a convex curve around its center. The film layer structure 6 spans an additional, ventilated hollow volume 9 on its side facing the light source 8. This ensures air pressure equalization on both sides and thus prevents air pressure-induced displacement of the film layer structure 6, which could impair the reproducibility of contact detection.

[0031] In the embodiment shown, the total layer thickness D of the diaphragm 1 varies locally and continuously along a linear profile across the entrance surface 14 through its geometric center, wherein a distribution of the total layer thickness D of the diaphragm 1 determined along the profile correlates with a luminance distribution of the light source 8 determined along the same profile. In other words, along a straight line from an outer edge of the entrance surface 14 through the geometric center of the entrance surface 14 to the opposite edge of the entrance surface 14, a local increase in the total layer thickness D is associated with a local increase in luminance, whereby the luminous surface 4 has a higher uniformity in the local backlighting along a profile corresponding to the light propagation in the diaphragm 1.For example, the highest luminance and the highest total layer thickness D are located at the geometric center of the entrance surface 14, while the locations of the locally lowest luminance and the locally lowest total layer thickness D also coincide from the perspective of the observer B.

[0032] Furthermore, a diaphragm support 7 is provided, on which the diaphragm 1 is supported and secured. The diaphragm support 7 has a light shaft surrounding the light source 8 and forming the further ventilated hollow volume 9 to guide the light from the light source 8 toward the entrance surface 14. The film layer structure 6 is clamped between the diaphragm 1 and the diaphragm support 7. The diaphragm support 7 is formed, for example, from an opaque material, such as an opaque plastic, in particular an opaque thermoplastic. Cooperating locking means 15 are provided for securing the diaphragm 1 to the diaphragm support 7.

[0033] Here, the panel 1 has support bases 16 formed in the rear surface 21, projecting in the direction of the panel support 7, which extend through correspondingly arranged openings in the film layer structure 6 and via which the panel 1 is supported on the panel support 7. Additional ventilated hollow volumes 22 are provided between the panel 1 and the intermediate support 7.

[0034] As shown in the embodiment shown, the aperture 1 and the aperture carrier 7 together form an actuating part 25 which, when an actuating force F acts on the input surface 3, is movable from a rest position into an actuated position along a travel path s substantially perpendicular to the input surface 3, counter to a restoring force generated by a return element (not shown) belonging to the input arrangement 10, such as a spring element. For example, the travel path is only a fraction of a millimeter. The input arrangement 10 has a detection means 7 for detecting a change in the position of the actuating part 25, such as an electromechanical switch, a capacitive, inductive, resistive, inductive, or piezoelectric force sensor, or the like.

Claims

[1] Input arrangement (10), comprising: a panel (1) which has at least one touch-sensitive operating surface (3) facing an operator (B) and a rear surface (21) facing away from the operator (B), wherein the operating surface (3) includes a luminous surface (4) to be backlit; a support (2) arranged on the side of the panel (1) facing away from the operator (B); a light source (8) arranged on the support (2) which is arranged to couple light into the diaphragm (1) for backlighting the luminous surface (4) via an entrance surface (14) formed in the rear surface (21) facing the light source (8), wherein the diaphragm (1) is designed to be translucent at least in the region between the entrance surface (14) and the luminous surface (4); a light-permeable film layer structure (6) arranged between the aperture (2) and the light source (8) with a conductive coating for forming at least one electrode for a capacitive touch sensor system; wherein the entrance surface (14) is formed in or by a recess (23) in the rear surface (21) of the diaphragm (1), and characterized by , that a ventilated hollow volume (12) is formed between the film layer structure (6) and the inlet surface (14) of the diaphragm (1), and in that the layer thickness (d) of a layer (24) of the diaphragm (1) varies locally along a linear course over the inlet surface (14) through its geometric center. [2] Input arrangement (10) according to claim 1, wherein the entry surface (14) is curved, preferably convexly curved. [3] Input arrangement (10) according to one of the preceding claims, wherein the recess (23) reduces a layer thickness of at least one layer (24) of the diaphragm (1) in comparison to the region of the layer (24) immediately surrounding the recess. [4] Input arrangement (10) according to one of the preceding claims, wherein the hollow volume (12) is ventilated via an opening (13) in the film layer structure (6). [5] Input arrangement (10) according to one of the preceding claims, wherein the film layer structure (6) spans a further ventilated hollow volume (9) on its side facing the light source (8). [6] Input arrangement (10) according to one of the preceding claims, wherein a total layer thickness (D) of the aperture (1) varies locally along the linear course over the entry surface (14) through its geometric center, preferably varies continuously locally. [7] Input arrangement (10) according to the preceding claim, wherein a distribution of the layer thickness (d) or the total layer thickness (D) of the diaphragm (1) determined along the course correlates with a luminance distribution of the light source (8) determined along the same course. [8] Input arrangement (10) according to one of the preceding claims, further comprising a diaphragm carrier (7) on which the diaphragm (1) is at least supported, preferably fixed, and the diaphragm carrier (7) has a light shaft surrounding the light source (8) and forming the further ventilated hollow volume (9) in order to guide the light of the light source (8) in the direction of the entry surface (14), and the film layer structure (6) is clamped between the diaphragm (1) and the diaphragm carrier (7). [9] Input arrangement (10) according to the preceding claim, wherein the panel has support bases (16) formed in the rear surface (21) and projecting in the direction of the panel support (7), via which the panel (1) is supported on the panel support (7). [10] Input arrangement (10) according to one of the two preceding claims, wherein the diaphragm (1) and the diaphragm carrier (7) form an actuating part (25) which, when an actuating force (F) acts on the input surface (3), is movable from a rest position into an actuated position along the travel path (s) against a restoring force generated by a restoring element belonging to the input arrangement (10), and wherein the input arrangement (10) has a detection means (17) for detecting a change in the position of the actuating part (25). [11] Input arrangement (10) according to one of the preceding claims, wherein the total layer thickness (D) of the aperture (1) outside the recess (23) is not less than 5.0 mm. [12] Input arrangement (10) according to one of the preceding claims, wherein further ventilated hollow volumes (22) are provided between the panel (1) and the intermediate carrier (7). [13] Use of the input arrangement (10) according to one of the preceding claims in a motor vehicle.

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