GB2053574A

GB2053574A - Illuminated keyboard

Info

Publication number: GB2053574A
Application number: GB8020740A
Authority: GB
Original assignee: Jaeger
Priority date: 1979-07-04
Filing date: 1980-06-25
Publication date: 1981-02-04
Also published as: FR2460444A1; DE8017828U1; FR2460444B1; ES493453A0; IT8023183A0; ES8105461A1; IT1132162B; GB2053574B

Abstract

An illuminated keyboard comprises a sheet 1 of deformable insulating material impressed with bosses 2, the lower face of each boss 2 having deposited thereon an electrical contact 3 cooperating, upon deformation of the boss, with a contact 4 carried on the upper face of an insulating plate 5, disposed below the sheet 1. Depression of a key at F causes portion 27 of the key to deform the boss 2 and mate contacts 3 and 4 together: the point of manipulation F of the key is offset from the boss 2 and portion 27 so that a light source placed below the plate 5 illuminates the key without any obscuring by the contacts 3, 4. <IMAGE>

Description

SPECIFICATION Illuminated keyboard The present invention relates to a keyboard in which an electrical contact is made for each key by depression of a deformable diaphragm, and in which the key of are illuminated.

Keyboards of this type are known, comprising in general a first sheet of deformable insulating material in which embossing is impressed in relief, the bosses generally being hemispherical and having deposited on its lower faces, for example by silk-screen printing, respective electrical contacts connected to appropriate circuits and cooperating, by deformation of the respective bosses, with other contacts carried by the upper face of an insulating plate which is disposed below the first and comprises second electric circuits with which the first are to be connected. The deformation of the embossing is ensured in conventional manner by a system of keys.

Illumination of the keyboard, enabling the keys to be located in the deark, may be effected from below, if both these and the sheet and plate are made of transparent or translucent materials.

Nevertheless, since the electrical contacts lie on the axis of the control keys, they project shadows into the region to be lit. In order to overcome this disadvantage, it is possible to use, for example, an optical fibre system, surrounding and lighting the keys or push buttons. This solution is expensive, however, and necessitates the addition of auxiliary devices which complicate the assembly.

In accordance with the present invention, there is provided an illuminated keyboard, comprising a sheet of deformable insulating material impressed with bosses on the lower faces of which there are deposited respective electric contacts for cooperating, upon deformation of the individual bosses by respective keys, with other contacts carried on the upper face of an insulating plate disposed below said sheet, the portion of each key which effects deformation of the respective boss being offset in relation to the zone of manipulation of said key, and means for illuminating the keys from below being provided.

Embodiments of the present invention will now be described, by way of examples only, with reference to the accompanying drawings, in which: FIGURE 1 is a section through a key of a prior art keyboard; FIGURE 2 is a section through a key of a keyboard in accordance with the present invention; and FIGURES 3, 4 and 5 show, in section and plan views, respective further embodiments.

The prior art keyboard of Figure 1 comprise a sheet 1 of deformable insulating material in which embossing 2 is effected, for example by heating. A conducting layer or contact 3 is disposed, for example by silk-screen printing, on the middle of the lower face of each boss. A second contact 4 is disposed, facing the first, on the upper face of an insulating plate 5; A contact 6, carried by a key or push-button 7, acts on the boss, causing its flexion and a contact between contacts 3 and 4. It will be seen that, in this case, if a light source is disposed below the plate 5, said contacts, which are necessarily opaque, project a zone of shadow 26 on the push-button 7.

In order to overcome this disadvantage, and in accordance with the invention, in the keyboard of Figure 1 , there is an offset distance D by which the point of manipulation F (which actually represents the part to be lit) of the push-button is offset in relation to the boss 2 and a contact 27 of the push-button which acts on the boss 2. Different embodiments may be envisaged. For example rocking keys 8 (Figure 3) movable about a materialized axis or one consisting of two points 9 and 10 articulated on a plate 1 a contact 12 acting on the boss 2 being carried by an end 13 of said key.In this case, the lighting may be effected either directly by means of a light source placed directly below the sheet and the plate (both made of transparent or translucent materials), or by means of a light conducting member (glass, methyl polymethacrylate, polycarbonate etc....) A more advantageous arrangement consists (Figure 4) in making suitable cut-outs 14 in a monobloc member 1 5. These cut-outs define keys 1 6 the bending of which is sufficient for their ends 17 to act on the bosses 2. The monobloc member 1 5 may be made of transparent or translucent plastics material which may be colourless or coloured, it may likewise be surmounted by a film 18, for example of transparent or translucent plastics material comprising painted, silk-screen printed etc., indications.

A modification (Figure 6) consists in providing the monobloc member 1 9 of metal; in this case said member comprises, apart from the cut-outs 20 necessary for the flexibility of the keys 21, apertures 22 necessary for lighting the manipulating zones. The active end 23 of the key 21 may be provided with a pointed contact 24 so as to ensure more clearly the deformation of the boss 2.

It is likewise possible (Figure 5) for the stressed zones 25 of the keys to be concave or convex to enable a tactile sensation to be obtained which is adapted to requirements; moreover, these forms may likewise serve as optical lenses channeling the light provided by the light source placed below the keys.

1. An illuminated keyboard, comprising a sheet of deformable insulating material impressed with bosses on the lower faces of which there are deposited respective electric contacts for cooperating, upon deformation of the individual bosses by respective keys, with other contacts carried on the upper face of an insulating plate disposed below said sheet, the portion of each key which effects deformation of the respective boss being offset in relation to the zone of manipulation of said key and means for illuminating the keys from below being provided.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Illuminated keyboard The present invention relates to a keyboard in which an electrical contact is made for each key by depression of a deformable diaphragm, and in which the key of are illuminated. Keyboards of this type are known, comprising in general a first sheet of deformable insulating material in which embossing is impressed in relief, the bosses generally being hemispherical and having deposited on its lower faces, for example by silk-screen printing, respective electrical contacts connected to appropriate circuits and cooperating, by deformation of the respective bosses, with other contacts carried by the upper face of an insulating plate which is disposed below the first and comprises second electric circuits with which the first are to be connected. The deformation of the embossing is ensured in conventional manner by a system of keys. Illumination of the keyboard, enabling the keys to be located in the deark, may be effected from below, if both these and the sheet and plate are made of transparent or translucent materials. Nevertheless, since the electrical contacts lie on the axis of the control keys, they project shadows into the region to be lit. In order to overcome this disadvantage, it is possible to use, for example, an optical fibre system, surrounding and lighting the keys or push buttons. This solution is expensive, however, and necessitates the addition of auxiliary devices which complicate the assembly. In accordance with the present invention, there is provided an illuminated keyboard, comprising a sheet of deformable insulating material impressed with bosses on the lower faces of which there are deposited respective electric contacts for cooperating, upon deformation of the individual bosses by respective keys, with other contacts carried on the upper face of an insulating plate disposed below said sheet, the portion of each key which effects deformation of the respective boss being offset in relation to the zone of manipulation of said key, and means for illuminating the keys from below being provided. Embodiments of the present invention will now be described, by way of examples only, with reference to the accompanying drawings, in which: FIGURE 1 is a section through a key of a prior art keyboard; FIGURE 2 is a section through a key of a keyboard in accordance with the present invention; and FIGURES 3, 4 and 5 show, in section and plan views, respective further embodiments. The prior art keyboard of Figure 1 comprise a sheet 1 of deformable insulating material in which embossing 2 is effected, for example by heating. A conducting layer or contact 3 is disposed, for example by silk-screen printing, on the middle of the lower face of each boss. A second contact 4 is disposed, facing the first, on the upper face of an insulating plate 5; A contact 6, carried by a key or push-button 7, acts on the boss, causing its flexion and a contact between contacts 3 and 4. It will be seen that, in this case, if a light source is disposed below the plate 5, said contacts, which are necessarily opaque, project a zone of shadow 26 on the push-button 7. In order to overcome this disadvantage, and in accordance with the invention, in the keyboard of Figure 1 , there is an offset distance D by which the point of manipulation F (which actually represents the part to be lit) of the push-button is offset in relation to the boss 2 and a contact 27 of the push-button which acts on the boss 2. Different embodiments may be envisaged. For example rocking keys 8 (Figure 3) movable about a materialized axis or one consisting of two points 9 and 10 articulated on a plate 1 a contact 12 acting on the boss 2 being carried by an end 13 of said key.In this case, the lighting may be effected either directly by means of a light source placed directly below the sheet and the plate (both made of transparent or translucent materials), or by means of a light conducting member (glass, methyl polymethacrylate, polycarbonate etc....) A more advantageous arrangement consists (Figure 4) in making suitable cut-outs 14 in a monobloc member 1 5. These cut-outs define keys 1 6 the bending of which is sufficient for their ends 17 to act on the bosses 2. The monobloc member 1 5 may be made of transparent or translucent plastics material which may be colourless or coloured, it may likewise be surmounted by a film 18, for example of transparent or translucent plastics material comprising painted, silk-screen printed etc., indications. A modification (Figure 6) consists in providing the monobloc member 1 9 of metal; in this case said member comprises, apart from the cut-outs 20 necessary for the flexibility of the keys 21, apertures 22 necessary for lighting the manipulating zones. The active end 23 of the key 21 may be provided with a pointed contact 24 so as to ensure more clearly the deformation of the boss 2. It is likewise possible (Figure 5) for the stressed zones 25 of the keys to be concave or convex to enable a tactile sensation to be obtained which is adapted to requirements; moreover, these forms may likewise serve as optical lenses channeling the light provided by the light source placed below the keys. CLAIMS

2. A keyboard as claimed in Claim 1, in which the deformable insulating sheet as well as the plate are formed of transparent or translucent materials.

3. A keyboard as claimed in Claim 2, in which a light source is placed below the plate at right angles to the stressing point of the key.

4. A keyboard as claimed in Claim 2, in which a light conducting member is disposed below the plate

5. A keyboard as claimed in Claim 1, 3 or 4, in which each key of the keyboard is articulated by one of its ends on a plate disposed above the deformable sheet, its opposite end constituting the portion effecting deformation of the associated boss.

6. A keyboard as claimed in Claim 1, 3 or 4, in which a plate is disposed above the deformable sheet and comprises cut-outs defining the keys, the free ends which constitute the portion effecting deformation of the associated boss.

7. A keyboard as claimed in Claim 6, in which the plate comprising the cut-outs is formed of a transparent or translucent material.

8. A keyboard as claimed in Claim 7, in which the keys are formed with respective concave central portions.

9. A keyboard as claimed in Claim 7, in which the keys are formed with respective convex central portions.

10. An illuminated keyboard substantially as herein described with reference to Figure 2, 3 4, 5 or 6 of the accompanying drawings.