WO2009109875A1

WO2009109875A1 - Remote-control device with keypad

Info

Publication number: WO2009109875A1
Application number: PCT/IB2009/050756
Authority: WO
Inventors: Kian H. Ng
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2008-03-07
Filing date: 2009-02-25
Publication date: 2009-09-11

Abstract

The invention relates to a remote-control device(200) with a flexible keymat(220) above a rigid internal housing(210). Key-posts(222) of the keymat(220) project through key-holes(211) in the internal housing(210) to actuate domes(241) on a printed circuit board(240). In a preferred embodiment, the keymat(220) comprises U-shaped flaps(223) at its edges which hold the internal housing(210) in a form-fitting manner.

Description

Remote-control device with keypad

FIELD OF THE INVENTION

The invention relates to a portable electronic device, particularly a remote- control device, comprising a keypad with keys to be pressed by a user.

BACKGROUND OF THE INVENTION

The US 2007/0099650 Al discloses a portable electronic device like a mobile phone with a keypad. The complete front side of the electronic device is covered with a thin flexible sheet which is attached to a rigid carrier sheet below it. In the keypad, the carrier sheet has a large opening. An elastic patch layer may be bonded to the flexible sheet in said opening via which keystrokes are transmitted to switches of the internal electronics.

SUMMARY OF THE INVENTION

Based on this background it was an object of the present invention to provide means for a more flexible design of a portable electronic device like a remote-control device with a number of keys, wherein it is desirable that the device is robust and comfortable in its handling.

This object is achieved by a portable electronic device according to claim 1. Preferred embodiments are disclosed in the dependent claims.

The portable electronic device according to the present invention has a keypad in which one or usually several keys are located which can be pressed by a user for providing input to the device. The electronic device may particularly be a remote-control device as it is used for example for the control of a television set, a video recorder, a CD player or the like. In the following, exemplary embodiments of the invention will therefore often be discussed with reference to such a remote-control device, though this shall not limit the generality of the present invention. The device comprises the following components: a) A rigid internal housing having at least one key-hole in the area of the keypad, said key-hole being located at the position of a key of the device. b) A flexible keymat that covers the outer side of the keypad and that comprises at least one key on its outside with a corresponding key-post on its inside, said key-post extending through the key-hole of the internal housing. In this context, the terms "outside" and "inside" refer to the completely assembled device; the "outside" of the keypad is therefore the surface that can be touched by a user.

Moreover, it was already mentioned that the device will usually comprise a plurality of (e.g. ten to fifty) keys with corresponding kea-holes and kea-posts.

Because the complete keypad is covered by a flexible keymat, there are no gaps between the keys and their surroundings, which makes the device robust with respect to an exposure to dust and humidity. At the same time, a secure and comfortable operation of the keys is achieved because the keymat is supported by the rigid internal housing in the keypad area with (only) the key-posts extending through the key- holes of said housing; the flexible keymat will therefore effectively behave like being rigid in the surroundings of the keys.

There are various possibilities to mount the keymat and the internal housing within the complete device. According to a first variant of the invention, the internal housing and the keymat are materially bonded, which provides a very tight and secure coupling on a molecular level.

The aforementioned material bonding may for example be achieved by gluing the keymat to the internal housing. Preferably, the material fit is achieved by double moulding or over moulding the internal housing and the keymat. In this case the materials of the two components are brought into contact while at least one of them is still molten and can therefore join with the other material on a molecular level.

In another variant of the invention, the keymat and the internal housing are form- fittingly (i.e. positively) coupled. In this case each of the two components can be produced in a separate step, for example by simple (one component) moulding. A further advantage is that it is readily possible to combine different types of keymats with different types of internal housings during the assembly of the device.

A form- fitting coupling between keymat and internal housing can particularly be achieved if the keymat comprises at least one U-shaped flap extending along an edge of the keymat, said flap embracing the internal housing and keeping it in place. As the keymat is flexible, the flap will be flexible too, allowing to bend it as necessary during the assembly of the device. Preferably, the keymat comprises at least two such U-shaped flaps arranged in a mirror-image fashion along opposite edges of the keymat, thus being able to cooperatively grip the internal housing. Most preferably, U-shaped flaps are arranged continuously along the complete circumference of the keymat. According to a further development of the aforementioned embodiment, the flap of the keymat additionally embraces other components of the electronic device, for example a dome sheet and/or a printed circuit board (PCB). Thus it will be possible to assemble all these components simply by putting them together with the keymat in a form- fitting manner.

The keymat may be made from any material with a sufficient flexibility for the chosen thickness of the keymat. Preferably it is made from a rubber like silicon rubber (e.g. from Shin-Etsu Chemical Co., Tokyo, Japan), most preferably from synthetic thermoplastic rubber (e.g. Santoprene® TPE from Advanced Elastomer Systems, Belgium). The internal housing is preferably made from a plastic like:

HIPS (High Impact Polystyrene, e.g. available as LACQRENE 4440 ® from Total Petrochemicals, Belgium),

ABS (acrylonitrile butadiene styrene, e.g. available as CYCOLAC® from General Electric, as PA-757 from Chi Mei (Taiwan), or as Lustran ® 440 from LANXESS Deutschland GmbH), and/or

PC/ABS (Polycarbonate/Abstract blend, e.g. available as CYCOLO Y® from General Electrics).

The keys of the keymat are optionally covered by symbols printed onto them to provide a user with information about their function.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. These embodiments will be described by way of example with the help of the accompanying drawings in which: Fig. 1 shows a perspective top view on the internal housing of a first remote- control according to the invention;

Figs. 2 a) and b) show perspective views on the top side and the bottom side, respectively, of the keymat of the first remote-control;

Fig. 3 shows a perspective view on the bottom side of the internal housing of Fig. 1 assembled with the keymat of Fig. 2;

Fig. 4 shows a section along line IV-IV of Fig. 3;

Fig. 5 shows a perspective view of the complete first remote-control;

Fig. 6 shows an exploded view of the keymat, the internal housing, the dome sheet, and the PCB of a second remote-control according to the invention; Fig. 7 shows a section through the keymat along line VII-VII of Fig. 6; Fig. 8 shows a section through the components of Fig. 6 in their assembled state;

Fig. 9 shows a perspective view of the complete second remote-control. Like reference numbers or numbers differing by integer multiples of 100 refer in the Figures to identical or similar components.

DETAILED DESCRIPTION OF THE INVENTION

Figures 1 to 5 illustrate a first embodiment of a remote-control 100 according to the present invention.

Figure 1 shows separately a rigid internal housing 110 as a first component of the remote-control 100. The housing 110 comprises a plurality of holes, particularly keyholes 111 at the positions where the keys of the remote-control shall be located. The internal housing 110 may be reinforced on its back by studs (cf. Figure 3). Moreover, it may have screw holes on its back for an assembly with other components.

Figure 2 shows a flexible keymat 120 as a second important component of the remote-control 100. The keymat 120 extends essentially over the complete keypad of the remote-control, i.e. the area where keys to be actuated by a user are located. The keymat 120 comprises on its outside (Figure 2a), which can be touched by a user, an array of elevated keys 121 with symbols printed on them. On the inside of the keymat 120 (Figure 2b), key- posts 122 with a shape like frustrated cones are located at the positions of the keys.

As Figures 3 and 4 show, the key-posts 122 extend through the key-holes 111 of the internal housing 110 and further through holes in a dome sheet 130 to contact domes 141 on a printed circuit board 140. In summary, the described first embodiment of a remote control 100 combines a rubber keymat 120 and a rigid housing 110 to form an integrated housing. Double or over moulding can be used in the part making. Thermoplastics rubbers are preferred as materials due to their better properties in comparison to silicone rubbers. The coverage of the keymat 120 will only need to extend to existing key areas. The rubber key areas are able to deform slightly with posts 122 on the reverse side to activate domes on a PCB. Different sizes of housing (including faceplate) can be used in this concept. A modular approach can also be used to have more than one type of integrated housing design within the same product (different rubber hardness, colors, sizes and texture for better consumer appeal). The integrated design is compact and contributes to an attractive outlook with a smooth and slimmer curvature due to reduced thickness and capability to better withstand torsion.

Advantages of the described design comprise: i. Reduced overall plastic housing cost due to lesser material used. ii. Reduced number of tooling (less rubber keys) iii. Reduced components cost through only printing of single parts, iv. Reduced assembly cost through simpler production means, v. Reduced product weight with slimmer design, vi. Improved coffee test (no holes). vii. Improved ESD test. viii. Improved torsion strength ("composite" parts), ix. Improved environmental test (humidity), x. Improves product design cycle (lesser parts), xi. Improved user grip on products (users appeal). xii. Improved packaging and transport due to lesser components. xiii. Reduced waste material production which in term minimizes environmental impact.

Figures 6 to 9 show a remote-control 200 according to a second embodiment of the present invention. As in the first embodiment, the remote-control 200 comprises a rigid internal housing 210 with key- holes 211, and a flexible keymat 220 with keys 221 on its outside and corresponding key-posts 222 on its inside. In the assembled state, the key- posts 222 extend through the key-holes 211 of the internal housing 210. As Figure 8 shows, the key-posts 222 further extend through holes in a dome sheet 230 to act on domes 241 of a printed circuit board 240 when they are pressed by a user. In contrast to the first embodiment, the flexible keymat 220 comprises

U-shaped flaps 223 extending continuously along the edges of the keymat 220. According to Figure 8, said flaps 223 grip the internal housing 210 and the dome sheet 230 and keep them in place in a form- fitting manner and additionally by force/friction. The flaps thus act as holding mechanism to the sub-assembly. They can be deformed during the assembly of the other components.

Conventional molding can be used for making the components of the second remote-control device 200. Different sizes of the housing (including faceplate) can be used in this concept. Different flap designs can be used for different layers or types of components to be assembled. The integrated assembly is very simple, and the compact and slimmer profile contributes to an attractive outlook of the remote-control 200. Assembly concepts are product dependent; generally, the keymat is taken first and subsequently other associated components are inserted from behind.

In summary, the components which make up of the second remote-control 200 comprise: rubber keymat 220 (with wrap flaps); internal top housing 210; dome sheet 230;

PCB 240 (as possible); - screws (quantity upon need); bottom housing 250.

Advantages of the described design comprise: i. Reduced complex tooling issues (double injections type), ii. Reduced components cost through simpler and cheaper components design. iii. Reduced assembly cost through simpler production means, iv. Reduced product weight with slimmer design, v. Improved product design cycle (lesser precision parts), vi. Promoted soft touch feature with lower cost.

Finally it is pointed out that in the present application the term "comprising" does not exclude other elements or steps, that "a" or "an" does not exclude a plurality, and that a single processor or other unit may fulfill the functions of several means. The invention resides in each and every novel characteristic feature and each and every combination of characteristic features. Moreover, reference signs in the claims shall not be construed as limiting their scope.

Claims

CLAIMS:

1. A portable electronic device with a keypad, particularly a remote-control device (100, 200), comprising: a) a rigid internal housing (110, 210) having at least one key- hole (111, 211) in the area of the keypad; b) a flexible keymat (120, 220) that covers the outside of the keypad and that comprises at least one key (121, 221) on its outside and a corresponding key-post (122, 222) one its inside, said key-post extending through the key-hole of the internal housing.

2. The device (100) according to claim 1, wherein the internal housing (110) and the keymat (120) are materially bonded.

3. The device (100) according to claim 2, wherein the internal housing (110) and the keymat (120) are produced by double moulding or over moulding.

4. The device (200) according to claim 1, wherein the internal housing (210) and the keymat (220) are coupled in a form-fitting manner.

5. The device (200) according to claim 1, wherein the keymat (220) comprises at least one U-shaped flap (223) extending along an edge of the keymat (220) and embracing the internal housing (210).

6. The device (200) according to claim 5, wherein the flap (223) embraces further components of the device (200), particularly a dome sheet (230) and/or a printed circuit board (240).

7. The device (100, 200) according to claim 1, wherein the keymat (120, 220) is made from a material selected from the group consisting of rubber, thermoplastic rubber, and silicon rubber.

8. The device (100, 200) according to claim 1, wherein the internal housing (110, 210) is made from plastic, particularly from HIPS, ABS and/or PC/ABS.

9. The device (100, 200) according to claim 1, wherein the key (121, 221) of the keymat (120, 220) is covered with a printed symbol.