DE20117019U1 - Foil-covered, magnetic keyboard with tactile feedback - Google Patents

Description

Christa Weisser

Enzianstr. 2

72336 Baiersbronn

MT 01 09.08.01 Foil-covered, magnetic keyboard with tactile feedback

The invention relates to a foil-covered, magnetic keyboard with tactile feedback and point and/or area illumination of the key fields for operating devices, machines, computers, controls, etc.

Conventional foil-covered keyboards with tactile feedback consist of a foil-covered carrier plate to which a circuit board equipped with individual short-stroke keys is attached. The short-stroke keys can be equipped with key caps and the short-stroke keys extend through openings to the front foil. For point illumination, openings in the key caps and LEDs are integrated on the circuit board. The construction of these short-stroke keyboards is very time-consuming and material-intensive and therefore very expensive. In addition, surface illumination is not possible. Other well-known foil-covered keyboards have no tactile feedback and no surface illumination of the key fields. Magnetic foil keyboards are also used, which consist of individual foils glued on top of each other. In detail, these are the decorative foil on the front, the magnetic foil, the spacer foil and the contact foil. Openings are integrated in the magnetic foil and the spacer foil. Metal plates with raised domes are inserted into these openings, with the raised domes reaching through the openings in the magnetic foil to the decorative foil. The disadvantage of these keyboards is that they have a very small pressure point and do not allow either point or surface illumination of the key surface. If there is a defect, this keyboard cannot be repaired and must be thrown away completely. In addition, no controllers or other electrical circuits can be integrated.

The object of the invention is to provide a keyboard of the type mentioned above which is covered with a foil, has a noticeable tactile feedback, is removable and allows the point and/or surface illumination of the key fields.

This task is solved with a foil-covered, magnetic keyboard with tactile feedback. A magnetic foil with holes and openings for the key cap plungers and for the press-in bolts or bushings is attached to a carrier plate with openings for the key caps and with press-in bolts or bushings, on which a foil is laminated as a decorative foil, as well as a spacer plate with openings for the metal plates and a circuit board with contact points or a switching foil attached to a carrier plate. This results in the following layer structure from top to bottom: decorative foil, carrier plate, magnetic foil, spacer plate, circuit board or carrier plate with switching foil. Magnetic metal plates are inserted into the openings in the spacer plate and are attracted to the magnetic foil. Key caps with plungers are inserted into the openings in the carrier plate, whereby the plungers of the key caps go through the openings in the magnetic foil and rest on the metal plate, whereby the plunger of the key cap is outside the middle of the key cap, i.e. is arranged eccentrically. For the point and/or area illumination of the key fields, LEDs are integrated on the circuit board or the switching foil, which reach through holes in the metal plates and the magnetic foil to the key cap. The key cap is designed as a reflector depending on the type of lighting - point and/or area illumination.

In a preferred embodiment of the foil-covered, magnetic keyboard with tactile feedback, openings and press-in bolts or bushings are provided in a front panel on which the decorative foil is laminated and which also serves as a carrier plate. On the back of the front plate, a magnetic foil with openings for the key cap plungers, as well as a spacer plate and a circuit board or switching foil with carrier plate are attached to the press-in bolts or bushings, with openings for the metal plates in the spacer plate and contact points on the circuit board. Key caps with plungers are inserted in the openings in the carrier plate, with the plungers passing through the openings in the magnetic foil and onto the metal plates that are inserted in the openings in the spacer plate and through the magnetic foil.

by pulling it to the bottom. By pressing the front foil .· ·· ·· · ···· ··· ··· &tgr; j .·

The key cap with the plunger is pressed downwards and the metal plate is pushed away from the magnetic foil. The conductive metal plate makes contact with the circuit board or the switching foil. After the front foil is released, the magnetic force pulls the metal plate upwards and thus also the key cap with the plunger, and the contact is broken.

In a further preferred embodiment, the button surfaces are spot and/or surface illuminated. To achieve this, holes are made in the metal plates and the magnetic foil, one above the other. LEDs are applied to the circuit board or the switching foil in the area of the holes. The button caps are designed in such a way that they have a cutout for spot lighting, and are designed to form a reflector for surface illumination. One or more LEDs can be installed in each button cap. The button caps also have holes for surface illumination so that the LEDs can protrude into the button caps.

A further preferred embodiment shows the same sandwich structure as listed above, but not as a detachable screw construction but as an adhesive construction, i.e. all layers or plates are glued together.

Another embodiment of the foil-covered, magnetic keyboard with tactile feedback has a front panel onto which the decorative foil is laminated and which also serves as a carrier plate, and in which there are openings and press-in bolts or bushings, whereby the openings are designed in steps, i.e. the opening on the back has a larger diameter than the opening on the front. The key cap with plunger and then the magnetic plate are inserted into the stepped opening from the back. The switching foil is then mounted with the carrier plate, whereby the metal plate is also inserted into the opening. A spacer and guide ring can also be inserted into the opening.

The invention is explained in more detail using an embodiment shown in the drawings.

Fig. 1: Cross-section of the magnetic keyboard

Fig. 2: Section through the magnetic keyboard with stepped opening

Fig. 3: Section through the magnetic keyboard with point and/or area illumination of the key surface

In the figures, unless otherwise stated, like sources of supply refer to like parts with like meaning.

1. Spacer film

2. Laminated decorative film

3. Carrier plate

4. Breakthrough in the carrier plate

5. Press-in bolt or bushing

6. Step-shaped breakthrough

7. Keycap

8. Tappet

9. Magnetic foil

10. Magnetic disc

11. Breakthroughs in the magnetic foil

12. Metal plate with contact points

13. Breakthroughs in the spacer film

14. Circuit board with contact points

15. Switch foil

16. Lower support plate

17. Spacer and guide ring

19. Drilling in metal plate

20. Drilling in magnetic foil

21. Reflector

22. Breakout in key cap

The decorative film 2 is laminated onto the carrier plate 3, which can be made of metal or plastic. In the carrier plate 3, openings 4 for the key caps 7 are arranged, and pre-press bolts or bushings 5 are pressed in. A magnetic film 9 is attached to these bolts or bushings 5, whereby the magnetic film 9 has openings 10 for the key caps 7 with plungers 8. The key cap plunger openings 10 in the magnetic film 9 are arranged eccentrically to the center of the key caps 7. The key caps 7 with the plungers 8 are inserted into the openings 4 in the carrier plate. The spacer film 1 with openings 13 for the metal plates 12 is arranged below the magnetic film 9, whereby the metal plates 12 are inserted into the openings 13. The contact-making circuit board 14 is arranged below the spacer film 1. The entire construction is screwed together as a sandwich solution. By activating the key cap 7 by pressing on the decorative foil 2, the key cap 7 is pressed downwards with the plunger 8, thus releasing the metal plate 12 from the magnetic foil 9 and pressing it onto the contact-making circuit board 14, making contact. After releasing the decorative foil 1, the magnetic foil 9 pulls the metal plate 11 upwards and thus the key cap 7 with the plunger 8 is returned to its original position.

Figure 2 shows the structure of the film-covered, magnetic keyboard with tactile feedback in section. The openings 4 in the carrier plate 3 are designed in a step-like manner 6. A spacer film 1 and a circuit board 14 or a switching film 15 with carrier plate 14 are attached to the underside of the carrier plate 3. In the step-shaped opening 6 in the carrier plate 3, magnetic disks 10 are inserted in the lower recess, which have an eccentric recess. A key cap 7 with a plunger 8 is attached in the upper part of the opening 6, with the plunger 8 passing through the eccentric opening in the magnetic disk 10. Metal plates with contact points 12 are inserted in the openings in the spacer film 13. The plunger 8 of the key cap 7 rests on the metal plate 12. By pressing the front foil 2 in the area of the key cap 7, the key cap 7 is pressed with the plunger 8 downwards onto the metal plate 12 and the metal plate 12 onto the contact-making foil 15. Because the recess is arranged eccentrically, the metal plate 12 comes off on one side first. This is how the contact is established.

Figure 3 shows the same keyboard structure as Figure 1, but with point and/or surface illumination of the key surface. LEDs 18 are mounted on the circuit board 12 or the switching foil 15. The metal plates 12 have holes 19 and the magnetic foil 9 has holes 20. The LEDs 18 protrude through these holes 19, 20 into the key caps 7 with plunger 8. The key cap 7 has a cutout 22 or a reflector 21. This illuminates the key surface.

Claims (13)

1. Foil-covered, magnetic keyboard with tactile feedback, characterized in that the keyboard is designed as a sandwich construction with at least the following layers (from top to bottom) decorative film, carrier plate, magnetic film, spacer film and circuit board with contact points or switching film with carrier plate, wherein the carrier plate, the magnetic film and the spacer film have openings of different sizes and key caps with plungers are inserted into the openings in the carrier plate and magnetic metal plates are inserted into the openings in the spacer film, which are attracted by the magnetic film and the plunger of the key cap rests on the metal plate and/or has a minimal distance to the metal plate. 2. Foil-covered, magnetic keyboard with tactile feedback according to claim 1, characterized in that the sandwich layers lie directly on top of each other and are screwed together to form a package. 3. A film-covered, magnetic keyboard with tactile feedback according to one of the preceding claims, characterized in that the sandwich layers are glued together. 4. Foil-covered, magnetic keyboard with tactile feedback according to one of the preceding claims, characterized in that the sandwich layers are spaced apart and are screwed and/or glued. 5. Foil-covered, magnetic keyboard with tactile feedback according to one of the preceding claims, characterized in that the magnetic foil and/or the spacer foil is not continuous, but is attached as discs in a stepped opening in the carrier plate. 6. Foil-covered, magnetic keyboard with tactile feedback according to one of the preceding claims, characterized in that the plunger of the key cap is arranged eccentrically to the center of the key cap, and the hole in the magnetic foil is also arranged so that it is aligned with the plunger. 7. A film-covered, magnetic keyboard with tactile feedback according to any one of the preceding claims, characterized in that the key caps have one or more plungers, wherein the plungers can be of the same or different lengths. 8. Foil-covered, magnetic keyboard with tactile feedback according to one of the preceding claims, characterized in that the magnetic foil and the metal plate have aligned holes for LEDs. 9. Foil-covered, magnetic keyboard with tactile feedback according to one of the preceding claims, characterized in that at least 1 LED per key surface to be illuminated is arranged on the circuit board or the switching foil in order to illuminate the key surfaces point-wise and/or over the entire surface, and there is an opening per LED in the key cap and the LED protrudes into the key cap. 10. Foil-covered, magnetic keyboard with tactile feedback according to one of the preceding claims, characterized in that the key caps are made in one or more parts and are designed as a reflector, so that a surface illumination of the key surface occurs. 11. A film-covered magnetic keyboard with tactile feedback according to any one of the preceding claims, characterized in that the LED projects through the plunger. 12. Foil-covered, magnetic keyboard with tactile feedback according to one of the preceding claims, characterized in that several LEDs are arranged per key. 13. Foil-covered, magnetic keyboard with tactile feedback according to one of the preceding claims, characterized in that the metal plates have at least two raised contact points for making contact.