DE19958518A1 - Glass keyboard has conducting coatings on keyboard surface(s) formed by flexible thin glass plate and bearer material plate(s) contacted via leadthrough(s) in bearer material plate - Google Patents

Abstract

The glass keyboard (1) has at least one keyboard surface formed by a flexible thin glass plate (2) and at least one bearer material plate (3), each with an electrically conducting coating (5,6) on their facing surfaces and held at a distance apart by a distance holder (7). The conducting coatings are brought into contact at the pressure point when the flexible thin glass plate is subjected to a pressure loading. The conducting coatings are contacted via at least one leadthrough (8) in the bearer material plate.

Description

The invention relates to a glass keyboard.

Such transparent pressure switch elements are also called touch panels known and are today often used as input media in the form of a header module used in front of flat screens or television screens. About that In addition, touch panels are also available without a combination with a flat screen screen or television screen as a control terminal instead of a classic one Keyboard inserted.

Various types of transparent touch panels are available on the market available. All designs have in common that the place of contact of the Surface of the touch panel with a finger or an auxiliary tool (pen or similar) is converted into electrical signals. Based on these signals the Touch point of the surface of the touch panel detected. Through a central Computing unit that both receives and signals from the touch panel evaluates as well as controls the flat screen, becomes a particularly operator allows friendly computer communication.

Visible to the user and partly "palpable" during operation the different touch panels have different user interfaces on. Touch panels based on capacitive operating principles demonstrate one mechanically non-compliant glass surface. The radio tion principle is based on the fact that due to the different Dielek tricity of the finger or the auxiliary tool compared to the air a capaci changes in movement around the point of contact. The disadvantage here is that too contamination around the point of contact erroneously as touch can be interpreted. Because the surface of thick glass (a few millimeters) exists, capacitive displays have a high mechanical, physical and chemical resistance. Capacitive displays are therefore, for example, in Communication terminals used in banks, information terminals or the like.

Ultra is based on comparable optical or electrical principles sound touch panels, infrared touch panels and field effect touch panels. Also  here the surface can be made of glass. Contamination is here too critical, so that such designs are aimed at similar areas of application like capacitive panels. However, their market share is much smaller than the capacitive panels.

Resistive touch panels, on the other hand, are based on plane-parallel spacing of a conductive, flat support, the base material of which consists of a few millimeter thick glass or plastic panes, with a thin, deformable film that is also conductively coated. When the film is touched, its deformation leads to local contacting of the two opposite conductive layers. There are basically two types of resistive touch panels:

• - The conductive layers have a very homogeneous, locally constant Surface resistance. By reading out the electrical voltage values because of the homogeneous surface resistance to the place of contact getting closed.
• - The conductive layers of carrier and film are structured so that dis Crete conductor tracks are created. By touching the touch panel a local short circuit between the discrete interconnects, which in Frame of the structure size of the conductor tracks on the contact location ge can be closed.

The film material is mainly available on the market Touch panels used transparent plastics. These are from Ab stands to the carrier material at a distance, so that a fault circuit (touching the conductive layers) without actuation is closed. Compared to other designs of touch panels An advantage of resistive touch panels is that one, albeit one, is used for actuation low mechanical deformation force must be exerted on the film. Therefore, their sensitivity to contamination is essential lower, which is why in safety-relevant areas such as medical technology and Industrial automation uses almost exclusively resistive touch panels become.

A disadvantage of using plastics as film material is that in Compared to glass user interfaces much smaller physical and Chemical resistance. Due to mechanical scratching, Cloudiness, UV radiation or surface damage from chemicals etc. there is a deterioration in transparency. Furthermore, the waiter  area sterilizability limited. Another disadvantage when using Plastics is in the lower thermal resistance (softening, Swelling) and the strong thermal expansions compared to glass. So the size of the touch panels is due to the swelling of the plastics highly limited. Are relatively simple and therefore inexpensive to manage such phenomena in smaller resistive touch panels like those at can be used, for example, in electronic diaries.

Novel designs of resistive touch panels are becoming a foil Use thin glass pane with a thickness of 0.15 mm to 0.4 mm has sufficient deformability. Such a surface has Advantages of chemical and physical resistance of glass at low Danger of incorrect switching.

EP 0 546 003 B1 describes a pressure formed from a glass laminate switching element known that from a flexible thin glass pane and min least a carrier material disk is formed, which towards each other facing surfaces each have an electrically conductive layer. Which Opposing electrically conductive layers are created using a Spacers kept at a distance. As a spacer there is a thin one Foil or a double-sided adhesive tape between the thin glass pane and arranged the carrier material disc. The electrically conductive layers touch the flexible thin glass layer on the im essential point pressure point.

The object of this invention is to provide a resistive glass keyboard find a simple and safe contacting of the electrically conductive Has layers and that with reduced effort in a compact design can be produced.

This object is achieved according to claim 1. In a glass keyboard ( 1 ) according to the invention with at least one keyboard surface formed from a flexible thin glass pane ( 2 ) and at least one carrier material pane ( 3 ), each of which has an electrically conductive layer ( 5 , 6 ) on the mutually facing surfaces, the the electrically conductive layers ( 5 , 6 ) face each other with the aid of a spacer ( 7 ) and the electrically conductive layers ( 5 , 6 ) touch each other when the flexible thin glass pane ( 2 ) is subjected to pressure at the essentially point-specific pressure load point, it is provided that the electrically conductive layer (5) of the thin glass pane (2) and the elec trically conductive layer (6) of the carrier material pane (3) is contacted by at least one passage (8) of the carrier material pane (3).

In this way, the electrically conductive layers ( 5 , 6 ) of the glass keyboard ( 1 ) are safely and easily contacted. Furthermore, the glass keyboard ( 1 ) according to the invention can be produced with little effort in a particularly compact construction.

In known glass keyboards, the electrically conductive layers are thin glass pane and the carrier material pane usually ver with conductor tracks bound over the respective side edges of the thin glass pane and the Carrier material disk guided and with ribbon cables in the area of Ab stand holder are contacted, the ribbon cable through the Ab stand bracket are guided.

The lateral contacting of the electrically conductive layers has one Series of disadvantages. So the already sensitive edge area is the Glass keyboard, especially the fragile edge area of the thin glass washer additionally weakened. A mechanical load on the flat belt cable or the lateral weakened edge area can lead to a strong Load up to the breaking of the glass keyboard. To avoid this and to cover the contact purely optically, such a glass is stature surrounded by a frame and thus protected. The distance between Thin glass pane and carrier material pane is characterized by the thickness of the Contact specified. Because the contacting through the spacer the contact gives the minimum distance between the Slices in front. Last but not least, the side contact disturbs the otherwise ho mogene optical appearance of the glass keyboard sensitive.

Compared to such a glass keyboard that is contacted via the lateral edge area, the glass keyboard ( 1 ) according to the invention has a number of advantages. The lateral edge area is not additionally weakened by the contact. The implementation ( 8 ) of the carrier material disc ( 3 ) withstands a mechanical load, for example a tensile load on a connection cable, much better. To protect the edge area, the frame can be completely dispensed with, at least in certain embodiments of the glass keyboard ( 1 ). The distance between thin glass pane ( 2 ) and carrier material pane ( 3 ) can be made independently of the contact. This makes it possible to set particularly small distances between the thin glass pane ( 2 ) and the carrier material pane ( 3 ). The glass keyboard ( 1 ) can be made much more compact. Depending on the application, one or more bushings ( 8 ) are arranged at any point on the carrier material disc ( 3 ). The optical homogeneous appearance of the glass keyboard ( 1 ) is retained. The glass keyboard ( 1 ) according to the invention can be handled easily and flexibly and can be integrated into other devices.

Preferably, the electrically conductive layer (5) is advantage kontak the thin glass pane (2) via at least one conductor track (65) on the carrier material pane (3) and / or via at least one conductor track (55) on the Dünnglascheibe (2).

The electrically conductive layer ( 6 ) of the carrier material disc ( 3 ) is further preferably contacted via at least one conductor track ( 66 ) on the carrier material disc ( 3 ).

At least one conductor track ( 55 , 65 , 66 ) is particularly preferably structured from the respective electrically conductive layer ( 5 , 6 ).

The respective contacting of the electrically conductive layer ( 5 ) of the thin glass pane ( 2 ) and the electrically conductive layer ( 6 ) of the carrier material pane ( 3 ) is preferably carried out via at least one contact ( 9 , 90 ), the contacts being insulated from one another.

Particularly preferably, an electrically conductive adhesive is used at least partially as the contact ( 9 , 90 ).

At least one contact ( 9 , 90 ) is guided through the feedthrough ( 8 ), the free end ( 99 ) of the contact ( 9 , 90 ) with a plug ( 10 ) or a multiple cable preferably passing through the feedthrough ( 8 ) is bound.

The electrically conductive layer ( 5 ) of the thin glass pane ( 2 ) and / or the electrically conductive layer ( 6 ) of the carrier material pane ( 3 ) can be divided into structurally structured, mutually insulated areas. The regions isolated from one another are preferably contacted by at least one bushing ( 8 ) in the carrier material disc ( 3 ).

The bushing ( 8 ) is preferably designed in the form of a bore or a slot.

The following examples and the drawings explain the invention. Show it:

Fig. 1 is a Glass keyboard according to the invention in cross-section,

Fig. 2 shows the Glass keyboard according to Fig. 1 in Aufschicht,

Fig. 3 shows a further glass keyboard according to the invention in cross section, and

Fig. 4 shows the glass keyboard according to Fig. 3 in top layer.

The glass keyboard shown in Fig. 1 and 2 (1) consists of a lower relatively thick carrier material pane (3) of glass and a thin glass pane held by means of a distance holder (7) in spaced parallel relation to the carrier material pane (3) (2). The thin glass pane ( 2 ) is slightly convexly curved outwards, but it can also be flat. Thin glass pane ( 2 ) and carrier material pane ( 3 ) are provided on the mutually opposite inner surfaces with electrically conductive layers ( 5 , 6 ) which form electrodes and which, when they come into contact with one another, produce a switching contact. For this purpose, the flexible thin glass pane ( 2 ) can be deformed by essentially pressurizing it in such a way that an electrical contact is made between the conductive layers ( 5 , 6 ).

The electrically conductive layer ( 5 ) of the thin glass pane ( 2 ) and the electrically conductive layer ( 6 ) of the carrier material pane ( 3 ) are contacted through a slot-shaped passage ( 8 ) of the carrier material pane ( 3 ) via a contact ( 9 ), the contacting the electrically conductive layer ( 5 ) is isolated from the contacting of the electrically conductive layer ( 6 ).

The contact ( 9 ) is designed using an electrically conductive adhesive and is guided through the bushing ( 8 ), the free end of the contact ( 9 ) being connected to a plug ( 10 ).

The structure of the glass keyboard ( 1 ) shown in FIGS . 3 and 4 essentially corresponds to the glass keyboard shown in FIGS . 1 and 2.

However, the electrically conductive layer ( 5 ) of the thin glass pane ( 2 ) is contacted on the carrier material pane ( 3 ) by means of several contacts ( 9 ) via conductor tracks ( 65 ).

Likewise, the electrically conductive layer ( 6 ) of the carrier material disc ( 3 ) via conductor tracks ( 66 , not shown in detail) on the carrier material disc ( 3 ) is contacted.

The conductor tracks ( 55 , not shown in detail) and the conductor tracks ( 65 , 66 ) are structured by means of structuring from the respective electrically conductive layer ( 5 , 6 ).

Furthermore, the conductor tracks ( 65 , 66 ) are contacted by a slot-shaped guide ( 8 ) of the carrier material disk ( 3 ) via a plurality of contacts ( 90 ), the contacting of the conductor tracks ( 65 ) being carried out in isolation from the contacting of the conductor tracks ( 66 ).

The contacts ( 9 , 90 ) are made using an electrically conductive adhesive. Furthermore, the contacts ( 90 ) are guided through the bushing ( 8 ), the free ends of the contacts ( 90 ) being connected to a plug ( 10 ).

Reference list

1

Glass keyboard

2nd

flexible thin glass pane

3rd

Carrier disc

5

electrically conductive layer of thin glass

55

Conductor track on the thin glass pane

6

electrically conductive layer of the carrier material disk

65

Conductor track on the carrier material disc

66

Conductor track on the carrier material disc

4th

Keyboard surface

7

Spacers

8th

execution

9

,

90

Contact

10th

plug

Claims (9)

1. Glass keyboard ( 1 ) with at least one of a flexible thin glass pane ( 2 ) formed keyboard surface and at least one carrier material disk ( 3 ), each having an electrically conductive layer ( 5 , 6 ) on the facing surfaces, the opposite the electrically conductive layers ( 5 , 6 ) are kept at a distance by means of a spacer ( 7 ) and the electrically conductive layers ( 5 , 6 ) touch when the flexible thin glass pane ( 2 ) is subjected to pressure at the essentially point-specific pressure load point, thereby in that the electrically conductive layer (5) of the thin glass pane (2) and the electrically conductive layer (6) of the carrier material pane (3) a passage (8) of the carrier material pane (3) is contacted by little least. 2. Glass keyboard according to claim 1, characterized in that the electrically conductive layer ( 5 ) of the thin glass pane ( 2 ) via little least one conductor track ( 65 ) on the carrier material pane ( 3 ) and / or at least one conductor track ( 55 ) on the thin glass pane ( 2 ) is contacted. 3. Glass keyboard according to claim 1 or 2, characterized in that the electrically conductive layer ( 6 ) of the carrier material disc ( 3 ) via at least one conductor track ( 66 ) on the carrier material disc ( 3 ) is in contact. 4. Glass keyboard according to at least one of claims 1 to 3, characterized in that at least one conductor track ( 55 , 65 , 66 ) from the respective electrically conductive layer ( 5 , 6 ) is structured. 5. Glass keyboard according to at least one of claims 1 to 4, characterized in that the electrically conductive layer ( 5 ) of the thin glass pane ( 2 ) and the electrically conductive layer ( 6 ) of the carrier material pane ( 3 ) each via at least one contact ( 9 , 90th ) is contacted. 6. Glass keyboard according to claim 5, characterized in that the contact ( 9 , 90 ) is at least partially an electrically conductive adhesive. 7. Glass keyboard according to claim 5 or 6, characterized in that at least one contact ( 9 , 90 ) is guided through the bushing ( 8 ). 8. Glass keyboard according to at least one of claims 5 to 7, characterized in that the free end ( 99 ) of the contact ( 9 , 90 ) is connected to a plug ( 10 ) or a multiple cable. 9. Glass keyboard according to at least one of claims 1 to 8, characterized in that the electrically conductive layer ( 5 ) of the thin glass pane ( 2 ) and / or the electrically conductive layer ( 6 ) of the carrier material pane ( 3 ) in any structured, isolated areas is divided.