Display device, instrument cluster, method for manufacturing

Abstract

Display device (2), comprising at least one display unit (3-6) for displaying image information, comprising at least one protective glass (8) covering the display unit (3-6), and comprising at least one decorative element (12), wherein the decorative element (12) is attached to the protective glass (8), characterized in that the protective glass (8) has a hydrophobic coating (11) on a front surface (10), that the protective glass (8) has a recess (13) on the front surface (10) that at least completely penetrates the hydrophobic coating (11), that the recess (13) is designed as a blind hole or as a groove, and that the decorative element (12) has at least one projection (16) that engages in the recess (13) and is bonded in the recess (13), such that the decorative element (12) is designed such that it has a section that projects into the recess (13) and a section that is on the front surface (10),and thus rests, at least in some areas, on the hydrophobic coating (11) of the protective glass (8).

Description

[0001] The invention relates to a display device with at least one display unit for displaying image information, with at least one protective glass covering the display unit, and with at least one decorative element.

[0002] Furthermore, the invention relates to a combination instrument with a corresponding display device and a method for manufacturing such a display device. State of the art

[0003] Display devices, instrument clusters, and methods for manufacturing the type mentioned above are known from the prior art. Display devices are provided in vehicles, particularly motor vehicles, to provide the driver with timely information regarding the vehicle's operation, such as the vehicle's current speed, the engine speed of any internal combustion engine, the engine temperature, or warning messages. This typically involves a display unit, especially a screen, which is protected from external influences behind a protective glass panel. To enhance the visual appearance, one or more decorative elements are often provided, arranged on a housing section of the display device that supports the display unit.A decorative element, in this context, is understood to be a fixed element that neither changes its position nor its shape during operation and serves as a simple visual element to improve the optical appearance of the display device. For example, it is known to provide the numerical scale of a speedometer by adding a scale ring that is applied to the housing and surrounds the display unit. With digital display units designed as a screen, such an arrangement of decorative elements within the viewing area of ​​the display unit is not possible or hardly feasible.

[0004] German patent application DE 10 2009 058 141 A1 discloses a display surface with a disc arranged in front of it, which has a recess or protrusion to which a structural element is attached. Besides functionally highlighting individual areas on the display surface, the structural element serves to decorate the display device with ornamental elements, making it appear more sophisticated to the user.

[0005] German patent application DE 699 11 431 T2 discloses a hydrophobic coating, in particular one applied to a glass pane of a vehicle. German patent application KR 10 2005 0 068 278 A discloses a riveted connection for motor vehicles. Finally, utility model DE 20 2013 001 276 U1 discloses a panel for the interior of a motor vehicle, with a groove-like recess into which an insert is placed, at least partially. Disclosure of the invention

[0006] The display device according to the invention, with the features of claim 1, has the advantage that the decorative elements can be provided at any location on the display device, even if the at least one display unit is designed as a display. According to the invention, the at least one decorative element is attached to the protective glass. This allows the decorative element to be positioned at any location on the display device. In principle, it is possible to attach the decorative element to the front or back of the protective glass, particularly by gluing. Here, the back is understood to be the side of the protective glass facing the display unit, and the front is understood to be the side of the protective glass facing the driver.

[0007] According to the invention, the protective glass has a hydrophobic coating on one front surface. This hydrophobic coating serves as an anti-fingerprint coating, preventing visible marks from being left behind when the protective glass is touched. However, a disadvantage of the hydrophobic coating is that it makes it difficult or nearly impossible to adhere decorative elements to the front surface of the protective glass. Therefore, the hydrophobic coating is preferably applied to areas where no decorative elements are intended.

[0008] According to the invention, the protective glass has a recess on its front side that penetrates at least the hydrophobic coating completely, and to which the decorative element is assigned. The recess thus penetrates at least the hydrophobic coating, so that at the location of the recess there is no hydrophobic coating that could hinder the adhesion of the decorative element.

[0009] According to the invention, the recess is designed as a blind hole or a groove. Both variants have the characteristic that they do not completely penetrate the protective glass, but rather provide a base formed by the protective glass. This allows the decorative element to be easily glued to the base or the base section of the recess.

[0010] According to the invention, the decorative element has at least one projection that engages in the recess, particularly at least laterally, in a form-fitting manner. The decorative element is thus designed according to the invention such that it has a section that projects into the recess and a section that rests, at least partially, on the front surface and thus on the hydrophobic coating of the protective glass. This provides the decorative element with a particularly secure hold on the protective glass. In particular, the interplay between the projection and the recess, which is at least laterally form-fitting and especially free of play, provides the decorative element with additional support on the protective glass.

[0011] According to the invention, the projection is bonded in the recess. Due to its arrangement in the recess, and thus in an area without a hydrophobic coating, the bonding of the projection to the protective glass can be carried out effectively and permanently.

[0012] According to an embodiment not belonging to the invention, the recess and the protective glass are formed as a penetrating opening, and the projection has a rivet head at its free end that engages the protective glass in a form-fitting manner. The opening is, for example, formed in the form of a perforation through which the projection extends completely. Due to its design as a rivet head, the projection has a cross-sectional widening at its end facing away from the decorative element and engaging the protective glass, which engages the protective glass on its rear side in a form-fitting manner, so that non-destructive removal of the projection or the decorative element from the protective glass is not possible. Preferably, the rivet head is initially shaped during assembly in such a way that it can be guided through the opening from the front to the back.Once the decorative element is in its desired final position, the free end of the projection that penetrates the opening is plastically deformed by heat and / or pressing in such a way that it forms the rivet head and engages behind the protective glass.

[0013] According to an embodiment not belonging to the invention, the recess on the back of the protective glass has a cross-sectional enlargement to accommodate the rivet head, at least partially. This cross-sectional enlargement at the rear-facing end of the recess or opening provides an area in which the rivet head can be countersunk into the protective glass. This allows for an overall compact design of the display device, since the rivet head preferably does not protrude, or only minimally protrudes, beyond the height or thickness of the protective glass. Thus, with increased strength of the decorative element on the protective glass, the thickness of the protective glass and the distance between the protective glass and the display unit to be protected are not increased, or only minimally.

[0014] According to an advantageous embodiment of the invention, the protective glass is bonded to the display unit, in particular the display, over its entire surface. The protective glass, which can be made of glass or plastic, thus preferably lies flat against the display. An adhesive is provided between the protective glass and the display unit, forming an optical bonding layer. The protective glass and the display unit thereby form a solid unit, and due to this special arrangement, the information displayed by the display unit is particularly clearly visible through the protective glass.

[0015] According to an embodiment not belonging to the invention, the rivet head is provided with a bonding layer, in particular made of bonding material or insulating material. The additional bonding layer on the rivet head prevents air inclusions from forming in the viewing area when the protective glass is applied to the display unit using the adhesive compound described above.

[0016] The instrument cluster according to the invention, comprising the features of claim 3, is characterized by a display device as described above. The instrument cluster according to the invention has the advantage that one or more decorative elements can be securely and permanently arranged at any desired location on the display device.

[0017] The inventive method for manufacturing a display device with the features of claim 4 serves to manufacture a display device as described above, comprising at least one display unit for displaying image information, at least one protective glass covering the display unit, and at least one decorative element. The inventive method is characterized in that the decorative element is attached to the protective glass. In particular, it is provided that the protective glass is provided, at least partially, with a hydrophobic coating on its front surface. It is particularly preferred that the protective glass is provided with a recess that penetrates at least the hydrophobic coating. The recess is advantageously designed as a blind hole, a groove, or as a through-hole that completely penetrates the protective glass.The decorative element is preferably provided with a projection that is inserted into the recess during assembly, as previously described. For secure attachment of the decorative element or the projection within the recess, the projection is bonded to the protective glass. Alternatively or additionally, it is preferred that the projection be designed as a rivet head that engages the protective glass in a form-fitting manner. Further embodiments and advantages will become apparent from the description of the display device above.

[0018] The invention will now be explained in more detail with reference to the drawing. The drawing shows: Fig. 1 a combination instrument with a display device for a motor vehicle, Fig. 2 a sectional view of the display device according to a first embodiment not belonging to the invention, Fig. 3A to 3D a method for manufacturing the display device according to a second embodiment and Fig. 4A to 4F describe a method for manufacturing the display device according to a third embodiment not belonging to the invention.

[0019] Fig. Figure 1 shows a simplified top view of a combination instrument 1 for a motor vehicle, which has a display device 2 for the graphical presentation of information to the driver. In this case, the display device 2 has several display units 3, 4, 5 and 6, which are arranged side by side and attached to a housing part 7 of the combination instrument 1 or the display device 2. Display units 3 and 5 are designed as pointer instruments, while display units 4 and 6 are designed as digital display units and displays, respectively.

[0020] The display device 2 also has a protective glass 8 that covers all display units 3 to 6 and thus protects them from external influences.

[0021] Fig. Figure 2 shows a sectional view through the display device 2 along line AA in the area of ​​the display unit 4, which is designed as a display. As shown in Figure 2, the following is a cross-sectional view: Fig. As can be seen in Figure 2, the protective glass 8 lies flat on the display unit 4 with an interposed adhesive layer 9, which is designed as an optical interlayer or optic bonding layer. Furthermore, the protective glass 8 has a hydrophobic coating 11 on its front surface 10 facing the driver, which, as an anti-fingerprint coating, prevents rapid soiling of the protective glass 8.

[0022] According to Fig. 1 and Fig. In the first embodiment, a decorative element 12 is applied to the front surface 10 of the protective glass 8 and attached to it. The decorative element 12 is bonded to the protective glass 8. Preferably, the protective glass 8 has a section in the area of ​​the decorative element 12 that is free of the hydrophobic coating 11 to ensure better adhesion of the decorative element 12 to the protective glass 8.

[0023] Fig. Figures 3A to D show a multi-step method for manufacturing the display device 1 according to a second embodiment. This method ensures that the decorative element 12 is permanently and more securely attached to the protective glass 8. For this purpose, it is provided that, according to Fig. 3A A recess 13 is first machined into the front surface of the protective glass 8, in particular by drilling or milling. The recess 13 is a blind hole or, as shown in the present embodiment, is formed as a groove on the front surface 10 of the protective glass 8. The recess completely penetrates the hydrophobic coating 11 provided on the front surface 10. Since the recess 13 does not completely penetrate the protective glass 8, it forms a base 14. An adhesive 15 is applied to this base.

[0024] Then, according to Fig. 3B the decorative element 12 is arranged on the protective glass 8. For this purpose, the decorative element 12 has a projection 16 facing the protective glass 8, the outer contour of which is shaped such that it can be inserted laterally into the recess 13 in a form-fitting manner. In particular, the projection 16 can be inserted laterally into the recess 13 essentially without play, as shown in the figures. By inserting the projection 16, the adhesive 15 is compressed in the recess 13.

[0025] Then, according to Fig. 3C irradiated the adhesive 15 from the back of the protective glass 8 with UV light to cure the adhesive 15.

[0026] Finally, the protective glass 8, together with the decorative element 12, is positioned or attached to the adhesive layer 9 on the display unit 4.

[0027] The decorative element 12 is thus permanently and securely held to the protective glass 8, which otherwise continues to be provided with the hydrophobic coating 11.

[0028] Fig. Figures 4A to F show a third embodiment, not belonging to the invention, for manufacturing the display device 2 in several steps. In contrast to the previous embodiment, the recess 13 now completely penetrates the protective glass 8, and the projection 16 of the decorative element 12 is such that it completely extends through the protective glass 8. The projection 16 thus protrudes from the back of the protective glass 8. By hot pressing, the free end of the projection 16 is plastically deformed into a rivet head 18, which engages the back of the protective glass 8, so that the decorative element 12 is positively locked to the protective glass 8, as shown in Figure 4A to F. Fig. 4B shown, and can only be solved by destroying it.

[0029] Then, according to Fig. 4C applies a bonding material 19 to the rivet head 18, preferably completely covering the rivet head 18. The purpose of the bonding material 19 is to form a bond with the adhesive layer 9 when the protective glass 8 is applied to the display unit 4 together with the decorative element 12, in particular without forming bubbles.

[0030] As in Fig. As shown in Figure 4D, the rivet head 18, due to its design, penetrates the adhesive layer 9 in certain areas when the protective glass 8 is mounted on the display unit 4. A dam material can also be used instead of the bonding material 19. The dam material prevents the adhesive layer 9 (low viscosity) from flowing out and defines the bond. The dam material has a higher viscosity than the adhesive layer or the optic bonding layer to ensure the required geometry in the cured state. It is important that the rivet head 18, together with the bonding material 19, protrudes less from the back of the protective glass 8 than the thickness of the adhesive layer 9 to avoid direct contact between the rivet head 18 or bonding material 19 and the display unit 4.

[0031] To reduce the overall height, the method presented here alternatively provides that the protective glass 8 has a cross-sectional extension 20 on its rear side in the area of ​​the recess 13, which is designed as an opening. This extension serves to at least partially accommodate the rivet head 18. For this purpose, the cross-sectional extension 20 is designed such that it at least substantially accommodates the rivet head 18, so that the rivet head is recessed on the rear side of the protective glass 8, as shown in Fig. 4E shown.

[0032] When the protective glass 8 is mounted together with the decorative element 12 onto the display unit 4 and the adhesive layer located thereon, the distance between the rivet head 18 and the display unit 4 is greater due to the countersunk arrangement of the rivet head 18, even if the bonding or insulating material 19 is applied to the rivet head 18, as shown in Fig. 4F shown.

[0033] The display device 2 produced in this way therefore has a low overall height and yet allows the decorative element 12 to be securely attached to the protective glass 8 or to a display device 2, which also meets the requirements for safety and stability in the operation of a motor vehicle.

[0034] As an alternative to the embodiment with a rivet head 18, a further embodiment, not shown here, provides that the free end of the projection 16 is equipped with one or more locking lugs which are elastically deformed when inserted into the recess 13 and engage behind the protective glass 8 when exiting the recess on the back side. The decorative element 12 can thus be clipped onto the protective glass 8, and no additional hot stamping step is necessary to create the rivet head 18.

[0035] Overall, the display device 2, through the embodiments described above, also offers the advantage that any adhesive used is protected, the thermal expansion properties of the different elements of the display device 2 are matched to each other, the decorative element 12 is securely held in place, the decorative element 12 has a high degree of variability with regard to its positioning due to its attachment to the protective glass 8, and the hydrophobic coating 11 is otherwise essentially retained.

Claims

[1] Display device (2), comprising at least one display unit (3-6) for displaying image information, comprising at least one protective glass (8) covering the display unit (3-6), and comprising at least one decorative element (12), wherein the decorative element (12) is attached to the protective glass (8), characterized by, that the protective glass (8) has a hydrophobic coating (11) on a front side (10), that the protective glass (8) has a recess (13) on the front side (10) that penetrates at least the hydrophobic coating (11) completely, that the recess (13) is designed as a blind hole or as a groove, and that the decorative element (12) has at least one projection (16) that engages in the recess (13) and is bonded in the recess (13), such that the decorative element (12) is designed in such a way that it has a section that projects into the recess (13) and a section that rests at least partially on the front side (10), and thus on the hydrophobic coating (11) of the protective glass (8). [2] Display device according to any one of the preceding claims, characterized by , that the protective glass (8) is glued over the entire surface of the display unit (4). [3] Instrument cluster (1) for a vehicle, characterized bya display device (2) according to one or more of the preceding claims. [4] Method for manufacturing a display device (2) according to claim 1 or 2, comprising at least one display unit (3-6) for displaying image information, comprising at least one protective glass (8) covering the display unit (3-6), and comprising at least one decorative element (12), characterized by , that the decorative element (12) is attached to the protective glass (8).

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