Method for producing a control element and control element

Abstract

A method produces a control element having a touch-enabled surface, in which a paste-like material is applied on a carrier plate. At least one raised structure element is formed by the paste-like material on the carrier plate. For this purpose, a stencil having inherent stiffness is arranged above the carrier plate and the paste-like material is pushed through at least one recess in the stencil.

Claims

1. A method for producing a control element for a motor vehicle, the control element having a touch-sensitive zone, the method comprising: arranging a stencil formed by a piece of sheet metal directly in contact with a carrier plate, the stencil having at least one cutout, the at least one cutout in the stencil being free of any threads, fibers or loops; applying a paste material to the at least one cutout in the stencil; and pressing the paste material through the at least one cutout to form at least one raised structural element on the carrier plate, the paste material being applied to the at least one cutout in such a way that the at least one raised structural element has a total height from the carrier plate corresponding to a thickness of the stencil, the at least one raised structural element forming a haptically perceptible sensing aid, wherein the carrier plate serves as a surface of a touchpad such that a user of the touchpad can feel control areas defined by the at least one raised structural element.

2. The method as claimed in claim 1, wherein the paste material is a ceramic material.

3. The method as claimed in claim 1, wherein the carrier plate is formed from a glass.

4. The method as claimed in claim 3, further comprising: heating the paste material to secure the paste material to the carrier plate.

5. The method as claimed in claim 1, wherein the at least one cutout in the stencil is produced by laser cutting.

6. The method as claimed in claim 1, wherein the stencil has first and second areas, the first and second areas of the stencil have different thicknesses, the first and second areas produce first and second raised structural elements, respectively, and the first and second raised structural elements have different thicknesses, corresponding respectively to the different thicknesses of the stencil.

7. The method as claimed in claim 1, wherein the carrier plate is formed of a glass of a touch screen, a plurality of raised structural elements are provided on the carrier plate to delimit different areas of the carrier plate, and the raised structural elements are selected from the group consisting of webs, letters and symbols.

8. The method as claimed in claim 1, wherein the paste material is pressed through the at least one cutout using a doctor blade.

9. The method as claimed in claim 1, wherein the paste material is colored so that the at least one raised structural element is also colored.

10. The method as claimed in claim 2, wherein the carrier plate is formed from a glass.

11. The method as claimed in claim 10, further comprising: heating the paste material to secure the paste material to the carrier plate.

12. The method as claimed in claim 11, wherein the at least one cutout in the stencil is produced by laser cutting.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other objects and advantages of the present invention will become more apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which:

(2) FIG. 1 shows a method which is known from the related art and in which a printing ink is applied to a print medium by screen printing;

(3) FIG. 2 is a schematic enlarged illustration of a structural element which is obtained by the screen printing method according to FIG. 1 and is then located on the print medium;

(4) FIG. 3 shows the application of structural elements, formed from a ceramic paste, to a glass surface of a control element which is shown in FIG. 5, wherein a perforated stencil made of a piece of sheet metal is used;

(5) FIG. 4 is a schematic enlarged illustration of one of the structural elements which are obtained by the method according to FIG. 3 and are then located on the glass surface; and

(6) FIG. 5 shows the control element which has a surface made of glass and onto which the structural elements made of ceramic are applied by the method illustrated with reference to FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(7) Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

(8) The screen printing method which is known from the related art, and by which printing ink 10 can be applied to a print medium 12, will now be illustrated with reference to FIG. 1.

(9) In the screen printing method, a screen 14 is used which comprises a frame 16 over which a fabric is stretched. The individual threads 18 of the fabric are illustrated schematically in FIG. 1. The fabric is coated with a material, for example a photopolymer, and then exposed in areas 20 in which color is not be applied to the print medium 12. The photopolymer which is not set is washed out at the other locations 22. In the screen 14, the areas 20 of the fabric which are impermeable to printing ink 10 then alternate with the locations 22 in the fabric at which the printing ink 10 can be pressed through the screen 14.

(10) The printing ink 10 is pressed through the fabric using a doctor blade 24 at these locations 22, and said printing ink 10 passes onto the print medium 12 (cf. the middle figure in FIG. 1). Subsequently, the printing ink 10 disperses in the region of the locations 22 on the print medium 12 and forms structures 26 in which the threads 18 of the fabric are apparent.

(11) Correspondingly, the structures 26 on the print medium 12 have unevennesses, corrugations or restrictions 28 at the locations at which the threads 18 of the screen 14 are located during the application of the printing ink 10 to the print medium 12 (cf. FIG. 2).

(12) The irregular shape of the structures 26 which can be obtained by the screen printing method is undesirable. Therefore, another method is used here in order to form raised structural elements, for example in the form of webs 32 or curves 34 on a control element such as for example a touch pad 30 (cf. FIG. 5).

(13) A tampon printing method, in which the paste-like material to be transferred is firstly arranged on a die and then transferred to the carrier to be printed on, is in fact also unsuitable for applying raised structural elements, which can serve as sensing aids, to a surface 38 of the touch pad 30. The quantity of ink or paste which can be applied in this way is in fact not sufficient to form raised structures which can be used as sensing aids.

(14) The touch pad 30 has a carrier plate 36 which is made of glass and on the surface 38 of the which the webs 32 and curves 34 are formed (cf. FIG. 5). The procedure during the formation of these structural elements is illustrated with reference to FIG. 3.

(15) A stencil 42 which is secured in a frame 40 is arranged over the carrier plate 36. The inherently rigid stencil 42 is formed from a piece of sheet metal in which cutouts 44 in the form of holes or slits or the like are provided. The cutouts 44 are located at the locations at which the webs 32 and curves 34 are to be arranged on the carrier plate 36. A ceramic paste 48 is then pressed through the cutouts 44 in the stencil 42 with a doctor blade 46 or similar tool (cf. the middle illustration in FIG. 3). The portion of the ceramic paste 48 which is pressed through the respective cutouts 44 forms the raised structural elements, for example in the form of the webs 32 or curves 34 on the surface 38 of the carrier plate 36 (cf. the middle and lower illustrations in FIG. 3).

(16) The cutouts 44 in the piece of sheet metal of the stencil 42 can be lasered or punched. As a result of the fact that there are no threads whatsoever of a fabric or the like in the region of the cutouts 44, there are also no threads apparent in the webs 32 or curves 34. A defined height of the webs 32 or curves 34 can also be predefined by predefining the thickness of the piece of sheet metal of the stencil 42.

(17) FIG. 4 is a schematic view of one of the webs 32. This web 32 has clean edges 48 and a smooth level surface 50.

(18) After the webs 32 and curves 34 have been applied to the surface 38 of the carried plate 36 by the method illustrated in FIG. 3, the carrier plate 36 is burned. As a result, the ceramic webs 32 and/or curves 34 become connected to the carrier plate 36 which is formed from glass.

(19) Different structural elements, inter alia also a plurality of letters, can be formed on the surface 38 of the carrier plate 36 by the method illustrated in FIG. 3. However, the structural elements on the touch pad 30 serve as sensing aids or orientation aids which can be sensed haptically. A user of the touch pad 30 can therefore feel different control areas 52, 56, 60 on the touch pad 30 without having to direct his gaze onto the surface 38. For example radio stations can be selected by the control areas 52 or control panels which are delimited from one another here by the straight webs 32 which are parallel to one another and arranged on an upper edge 54 of the touch pad 30. However, depending on the operating state of the touch pad 30 any further or different functions can be stored in these control areas 52 of the touch pad 30.

(20) Further control areas 56 at lateral edges of the touch pad 30 are delimited here by the curves 34, and these control areas 56 can be assigned to different functions. A further control area 60 can be felt here by the user by another of the webs 32 at a lower edge 58 of the touch pad 30.

(21) The structural elements which are shown here by way of example in the form of the webs 32 and the curves 34 can also be provided at other locations on the touch pad 30 and can have shapes which differ from the shapes shown by way of example in FIG. 5.

(22) The carrier plate 36 is formed here from a glass, but the structural elements made of ceramic can also be applied by the method illustrated with reference to FIG. 3 to a carrier plate 36 which has merely a surface made of glass. The height of the structural elements which serve as sensing aids can also be set here by the consistency of the ceramic paste 48, which can be comparatively viscous, and the thickness of the piece of sheet metal of the stencil 42.

(23) The ceramic paste 48 can also be embodied as a colored paste-like material in order to form correspondingly colored structural elements on the surface 38 of the carrier plate 36.

(24) The invention has been described in detail with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention covered by the claims which may include the phrase at least one of A, B and C as an alternative expression that means one or more of A, B and C may be used, contrary to the holding in Superguide v. DIRECTV, 69 USPQ2d 1865 (Fed. Cir. 2004).