CURVED KEYPAD DEVICE

Abstract: This device comprises a curved keypad with a certain profile, comprising: on the outside, keys (6c, 6f and 6i) to be handled by the user; a contact configuration (21c, 21f and 21i) for containing contacts for each of the keys; a first flexible key-carrying sheet (15); a second flexible contact sheet (20) for forming said contact configuration, said sheets being curved for conforming in shape to said profile. Application: telephones.

Description: Curved keypad device The invention relates to a curved keypad device, comprising: on the outside, keys to be handled by the user, and a contact configuration for containing contacts for each of the keys. Such a device finds highly significant applications in lots of fields: remote control devices, pocket calculators, telephone terminals, etc. A device of this type is described in Patent Specification PCT No. WO 94/04974. This document describes a keypad for a computer which is to have a great quality of touch. It has a large number of separate keys positioned to correspond to a profile dictated by ergonomics. The fact that a large number of separate keys are to be provided complicates the manufacture and this does not permit to obtain an inexpensive product. The invention proposes a device of the type mentioned above which may be provided in an economic manner while having a good quality of touch. Therefore, such a device is characterized in that said keypad comprises: a first flexible key-carrying sheet, - a second flexible contact sheet for forming said contact configuration, and in that said sheets are curved for conforming in shape to said profile. These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. In the drawings: Fig. 1 shows a device according to the invention; Fig. 2 shows an exploded view of the keypad before its mounting, Fig. 3 shows an exploded view of the keypad after its mounting, Fig. 4 shows the section of a surface to which the tops of the keys are to be aligned, and Fig. 5 shows how the pressure of the finger influences the keys. The device shown in Fig. 1 is a telecommunications terminal of the handheld type which is connected to its base by radio. This device has a rounded form to give a handy grip. The device shown in this Fig. 1 has an earpiece 1 , a microphone 2, a screen 3, an antenna 4 and a keypad 5 which conforms to the profile defined by the form of the device. This profile may be split up into two profile lines. Along the longitudinal axis L, the keypad 5 has a concave profile line and along the transversal axis T a convex profile line. The keypad 5 comprises keys 6a, 6b, 6c, 6d, 6e, 6f, 6g, 6h, 6i which protrude outward and present themselves harmoniously, similar to said profile. Fig. 2 shows a part of the keypad 5 which relates to the second profile line. The keypad 5 is formed by the following component parts: a rigid exterior plate 10 which takes the form of the device and which has a certain profile so that the assembly has a harmonious form. This plate has openings 1 la, 1 lb ... to let all the keys 6a, 6b, ... pass through. a key-carrying sheet 15 on which said keys are formed. Only three keys 6c, 6f and 6i are shown in the Figure. a contact sheet 20 comprising the contacts 21c, 21f and 21 i in the form of a dome only visible in the figure. These contacts are each associated to the respective keys 6c, 6f and 6i, and finally, a rigid supporting or insertion plate 25 for protecting the circuits accommodated inside the device and having the same profile as the plate 10. These two sheets are made of flexible plastic material of the elastomer type for the first sheet, of the Mylar type for the second sheet, surrounding metallic lamellas. Once manufactured, the sheets 15 and 20 always occur in planar form, and therefore they are shown as such in this Figure. Fig. 3 shows the keypad 5 once it has been mounted, that is to say, once the plate 10 which can be clipped into the body of the device, comes close to the intermediate plate 25 taking the shape of the body of the device. This action provides that the sheets 15 and 20 are curved and conform in shape to the desired profile. For providing that the tops of the keys homogeneously pass through plate 10, these keys are to fit in a section S of a reduced-size surface of the profile during manufacture to compensate for the excessive unevennesses caused by the profile, as is shown in Fig. 4. This Figure also shows the mechanical cooperation of the two sheets 15 and 20. The presence will be noted of studs ... 30c, 30f and 30i assigned each to keys ... 6c, 6f and 6i intended to depend on the domes ... 21c, 2 If and 21i. This curving of the sheets 15 and 20 is particularly advantageous for obtaining free contacts, as is shown in Fig. 5. Indeed, the pressure F of the user's finger is exerted in a normal direction D to the surface of the device, so that the pin 30c receiving the force F in the direction D normally transmits the force F to the dome 21c, thus in best conditions. It will be noted that the keypad, being pressed against the casing of the device, takes up minimum space in the device. It is to be preferred for certain marketed contact sheets 20 that they are curved only along a profile axis.

Claims: Claims: 1. A curved keypad device with a certain profile, comprising: on the outside, keys to be handled by the user, a contact configuration for containing contacts for each of the keys, characterized in that said keypad comprises: - a first flexible key-carrying sheet, a second flexible contact sheet for forming said contact configuration, and in that said sheets are curved for conforming in shape to said profile. 2. A keypad device as claimed in claim 1 , characterized in that the tops of the keys are provided on a surface derived from said profile. 3. A keypad suitable for use in a device as claimed in claim 1 or 2, having a certain profile, characterized in that it is formed by keys to be handled by the user, a first flexible key-carrying sheet, a second flexible sheet for containing contacts to be put opposite said keys, and in that said sheets are curved so as to conform in shape to said profile. 4. A keypad as claimed in claim 3, characterized in that the tops of the keys are provided on a surface derived from said profile.

Inventors: FLEGEO ARNAUD, SAUVAGE MICHAEL, FLEGEO, ARNAUD, SAUVAGE, MICHAEL
Applicants: FLEGEO ARNAUD, PHILIPS ELECTRONICS NV, SAUVAGE MICHAEL, FLEGEO, ARNAUD, PHILIPS ELECTRONICS N.V., SAUVAGE, MICHAEL
Application year: 1997
Main classification: H01H13
IPC codes: H01H13