LU85611A1 - SCHALTER / ANZEIGE-EINHEITEN - Google Patents

Description

♦ * -1-

Switch / display units.

The invention relates to switch / display units.

In the English patent specification No. 2002522 a touch switch with an integrated electro-luminescent display is described. This switch can be designed so that the switch, or a label on the switch, lights up when the switch is actuated. The illuminated area of the switch is defined by an isolating screen, which determines the excitation area of a phosphor layer. In this way, after the switch has been manufactured, the area to be illuminated is defined, so that the switch is only suitable for performing a single function. The present invention proposes a switch / display unit in which the display can be varied electronically, 15 thereby providing a programmable multifunction switch.

According to the invention, such a switch / display unit is characterized by a transparent non-conductive panel, a first set of elongated parallel electrodes 20 formed from a transparent conductive material on the back of the said panel, a phosphor layer which is in contact with the said first set of electrodes Is a second set of parallel * elongated electrodes which are attached to the back of the phosphor layer, the second set of electrodes being inclined to the first set of electrodes so that the electrodes of one

Set overlap those of the other set, forming a dot matrix, and through a transparent conductive layer provided on the front of the non-conductive panel that covers the first set of electrodes.

The conductive layer in front of the non-conductive panel / can be attached to the front of the panel. In this structure, the conductive layer capacitively couples the electrodes on the back of the panel. This capacitive coupling can be changed by attaching an electrical charge to the conductive layer, for example by touching or grounding the conductive layer and using this change in the coupling state Generate signal for switching purposes.

5 Alternatively, the conductive layer can be a certain distance from the front of the non-conductive panel, but arranged so that it can be brought into contact with the panel. In such an arrangement, the electrodes on the back of the panel are initial The capacitive coupling is not very strongly coupled with one another, but they are coupled with one another when the conductive layer is brought into contact with the panel. Again, the change in the coupling state can be used to generate a signal for switching purposes.

15 For switching purposes, the first set of electrodes can be divided into two groups. Reading pulses can be applied to one of these groups of electrodes with the aid of a circuit. The other electrode group can be connected to a circuit which can detect the signal change on this 20 electrode group which arises from the change in the capacitive coupling between the electrode groups when the switch is actuated, whereupon a switching operation is initiated on the basis of this change. Alternatively, an additional electrodes can be provided on the back of the non-conductive panel in order to take over the functions of one or the other electrode group, so that for

Example the whole set of electrodes on the back of the non-conductive panel these impulses can be given and a separate electrode is used for sensing purposes.

In order to cause lighting, pulses of one polarity of one or more electrodes of the first electrode set and pulses of the opposite polarity of one or more electrodes of the second electrode set are applied. Where a pulse-loaded electrode of the first 35 sets lies above a pulse-loaded electrode of the second set, the phosphor interlayer creates a * sufficiently large potential to excite the phosphor and to bring this point to light. The desired -3-

Syiribol or the desired lettering can be built up from illuminated dots by applying suitable electrodes to each set of electrodes. Typically, the first and second sets 5 of elongated electrodes have between 20 and 40 electrodes per centimeter.

The read pulses applied to the electrodes for switching purposes can characteristically only have a voltage * of 10 volts and be of any polarity. However, it is advantageous to use the same circuit for the application of the reading pulses and the lighting control pulses to the electrode set on the rear of the non-conductive panel. The read pulses are applied at intervals between lighting pulses. For example, 15, the minimum potential difference in order to illuminate the phosphor layer is typically between 80 and 120 volts. Accordingly, the suitable electrodes of an electrode set are given lighting pulses with a voltage between +40 to +60 volts and the suitable electrodes of the other electrode set are given pulses with a voltage between -40 to -60 volts. These pulses typically have a duration of 10 to 30 microseconds and a frequency of 0.5 to 2 kHz. Read pulses of the same amplitude as the 25 of the lighting pulses (± 40 to ± 60 volts) are applied to all electrodes of the first electrode set or a group of the first electrode set between the lighting pulses. These pulses typically have a duration of 10 microseconds and a frequency of 500 Hz.

30 exemplary embodiments of the invention are shown in the

Drawings in which the same parts are provided with the same reference numbers are shown and are described in more detail below. Show it:

Figure 1, schematically an exploded view of a switch / display unit according to the invention;

Figure 2, the side view of a section of the switch / »display unit according to Figure lj JL Figure 3, a section along the line III-III in Figure i *» -4-

Figure 4 / a view similar to that of Figure 3, showing a modified switch / display unit;

Figures 5 and 6, schematically and in section variants of the switch / display unit according to Figures 1 to 4; 5 Figure 7, schematically and in section another

Execution of a switch / display unit according to the invention;

Figure 8, a view similar to that of Figures 3 and 4, which shows an inventive arrangement of ’2 £ 6 switch / display units.

10 The switches / shown in Figures 1 to 3

Display unit comprises a panel 10 which is made of a transparent, non-conductive material, e.g. Glass exists.

A set of transparent, elongated, parallel electrodes 11 made of an electrically conductive material, such as tin oxide, is provided on the back of the panel 10. At the

A transparent layer 12 of conductive material is attached to the front of the panel 10 in such a way that it covers the electrode set 11 on the back of the panel 10.

A phosphor layer 13 is applied to the back of the electrode set 11, while a second set of elongated, parallel electrodes 14 is provided on the back of the phosphor layer 13. The second electrode set 14 is arranged such that the electrodes run at right angles to the electrodes 11 of the first set, where each electrode of the one set overlaps all electrodes of the other set, so that a dot matrix is formed.

As can be seen from FIG. 3, the electrodes 11 are provided with input connections 15 which are connected to a circuit with which a voltage pulse can be individually supplied to each electrode. The electrodes 14 have similar input connections (not shown), by means of which they are connected to a circuit in order to individually supply each electrode 14 with a voltage pulse with the opposite polarity to that which is supplied to the electrodes 11. Characteristically, the phosphor layer used has a lighting threshold, - - - - -— »· -> * - -5- • - * ♦ t

Voltage pulse is between 40 and 60 volts and the pulses supplied to the electrodes 14 are between -40 to -60 volts. When pulses are applied to an electrode in each of sets 11 and 14, a potential with a voltage of 80 to 120 volts arises through the phosphor layer 13 at the point where these electrodes 11 and 14 overlap. This potential excites the relevant section of the phosphor layer 13 and produces a luminous point. By simultaneously applying pulses to 10 appropriate electrodes in each set of electrodes 11 and 14, the majority of the dots can be illuminated to form a label or symbol. The inscription or symbol can be changed by applying pulses to different electrodes in sets 11 and 14. These lighting pulses typically have a duration of 10 to 30 microseconds and are supplied to the electrodes at a frequency of 0.50 to 2 kHz while the display is illuminated.

In order to provide switching means, the electrode set 20 11 is divided into two groups X and Y, as shown in FIG. 3. The group Y is provided with a set of output terminals 16 by means of which it can be connected to a suitable sensing circuit. Now all of the electrodes 11 in group X can be supplied with these pulses 25 at the same time, making them capacitive, through the conductive

Layer 12, with which electrodes 11 of group Y are coupled and thus an output pulse is transmitted to electrodes 11 of group Y. This output pulse can be detected by the filler circuit. To actuate the switch, an electrical charge is supplied to the conductive layer 12, for example by a person touching the conductive layer 12. This charge reduces the capacitive coupling between the groups X and Y of the electrode set 11 and thus also the signal on electrodes 11 of group Y. This signal reduction can be detected by the sensing circuit and used to complete the switching process.

I The circuit for emitting illumination pulses to the electrodes 11 can preferably also be used to emit the read pulses; However, instead of impinging individual electrodes 11 on the pulse, as is necessary for the lighting up, it is set up in such a way that all the electrodes 11 of group X 5 are impinged simultaneously. These read pulses are applied between the lighting pulses and have a characteristic duration of 10 microseconds at a frequency of 500 Hz. Since no pulse is applied to electrodes 14 when reading pulses are applied to electrodes 11, the potential reaches through the phosphor layer Illuminated spot, so that the display is not affected.

The switch / display unit described above provides a display which can be changed as desired. The switch can therefore be used as a programmable 15 bar multifunction switch, for which the display is designed to change in response to a switch operation or in response to the operation of other switches in, for example, an arrangement of similar switches / displays -Units.

Instead of dividing the set of electrodes 11 into two groups X and Y as described above, an additional electrode 20 can be provided on the rear of the panel 10, as shown in FIG. The phosphor layer 13 and the second set of parallel electrodes 14 are provided on the back of the first set of electrodes 11, i | the display being operated in the manner described above.

For switching purposes, however, all electrodes 11 of the set are given read pulses at the same time. The conductive layer 12 is further expanded so that it extends both over the electrode set 11 and over the electrode 20, as a result of which the electrodes 11 and the electrode 20 are coupled to one another. The electrode 20 is connected to a suitable sensor circuit so that a signal change when a charge is applied to the conductive layer 12 can be detected and a switching process can be initiated, as described above. An additional guard electrode I trode 21 is on the back of the panel 10 between the Λ -7-

Electrode set 11 and the electrode 20 are provided. This guard electrode 21 is connected to the earth, so that a direct connection between the electrode 11 and the electrode 20 is minimized.

5 The switch / display units described above can be modified, as shown in FIG. 5, by providing a transparent, elastic conductive membrane 40 in front of the conductive layer 12, this membrane 40 being separated from the conductive layer 12 by means of spacers. 10 ken 41 is kept at a distance. This modified switch / display unit is actuated by a person who presses the membrane 40 down until it comes into contact with the conductive layer 12. As a result, the conductive layer 12 is grounded by the membrane and the person touching the membrane, which results in the resultant. electrical charge on the conductive layer 12 causes a reduction in the capacitive coupling of the switch, as described above. The movement of the membrane 40 gives the person operating the switch a 20 tactile reaction. The membrane 40 can be formed as a bubble-like structure over the conductive layer 12, so that when pressed down it comes into contact with the conductive layer with a snap feeling. Instead of the spacers 41, these bubble-like structures can also serve to separate the membrane 40 from the conductive layer 12.

In the switch shown in FIG. 6, a membrane 45 consists of a transparent, non-conductive, elastic plastic material and is shaped in such a way that a bubble-like structure 46 is formed which covers 30 the conductive layer 12 and is separated therefrom. The inner surface of the membrane 45 is provided with a transparent conductive covering 48, the latter of which is connected to the earth. When this switch is actuated by depressing the bubble structure 46, the conductive layer 12 is connected directly to the earth 35 by the covering 48. The resulting change in capacity is therefore independent of the person operating the switch and * provides a more pronounced signal change _ _ v. . -. 'S. - * 4 -8- version can be operated using non-conductive actuators.

When the pressure against the bubble structure 46 ceases, the latter will snap back from the conductive layer 12/5, so that the capacitive identifiers of the switch return to their original values when the switch is not actuated.

The central section of the bubble structure 46 can be designed as a lens 47, through which the display 10 is enlarged.

In the switch / display unit shown in FIG. 7, the arrangement of the electrode sets 11 and 14 and the phosphor layer 13 on the back of the non-conductive panel 10 is the same as that described with reference to FIGS. 15 1 to 3. However, instead of a conductive layer 12 being provided on the front of the panel 10, a conductive covering 52 is provided on the rear of a bubble structure 51, which is formed in a transparent, elastic conductive membrane 50 and is thus arranged in front of the panel 20 10, that it covers the electrode set 11 and has a certain distance from the front of the panel 10. The conductive layer 52 is electrically insulated. With this construction there is little or no coupling between groups X and Y of electrodes 11 when the switch is in the non-actuated state. Accordingly, if read pulses are applied to the electrodes 11 of the group X, no or only a very small output pulse will result at the electrodes 11 of the group Y. However, when the blister structure 51 is depressed so that the covering 30 52 comes into contact with the top of the panel 10, the electrodes 11 in the groups X and Y are capacitively coupled to one another by the covering 52. A read pulse applied to the electrodes in group X will now generate an output pulse of pronounced amplitude 35 on electrodes 11 of group Y, which output pulse can be used to initiate a switching process.

This switch design, in which the conductive II layer 52 is at a certain distance from the front side of the non-conductive panel 10, can be used together with other arrangements of electrodes on the rear side of the non-conductive panel 10, for example in the form described with reference to FIG. 4.

5 The switches described above can be used individually, but several such switches can also be used together. However, this type of construction is suitable for producing an arrangement of switch / display units on a single panel, as shown in FIG. 10 8. This figure shows a 2 to 6 arrangement of switch / display units, two rows of 6 switch / display units being provided on a non-conductive panel 30. Two sets of transparent elongate electrodes 31 are provided on the back of the panel 30. On the back of the panel 30, between the sets of electrodes 31, two rows of 6 separate transparent electrodes 32 are also provided. Each set of electrodes 31 is capacitively coupled to the adjacent row of electrodes 32 by means of individual transparent conductive layers 33 provided on the front of the panel 30 20. Each conductive layer 33 covers a different electrode 32 and part of the adjacent set of Electrodes 31. As noted above, the two sets of electrodes 31 may be connected to a circuit for delivering read pulses while the electrodes 32 are connected to a suitable sensing circuit. The application of an electrical charge to one of the conductive layers 33 changes the coupling between the electrode set 31 and the electrodes 32 covered by the conductive layer 33, whereby! 30 the signal change can be sensed on the electrode 32 S ....

j to perform a switching operation associated with this switch.

! A v ’phosphor layer is applied to the back of the electrodes 31 and 32 and two further sets of parallel elongated electrodes are attached to the back of the phosphor layer in the manner described above. The display means of each switch can be controlled in this way by applying pulses to the appropriate electrodes on any side of the phosphor layer, as shown in FIG. 4.

-10- with reference to the individual switch / display units? has been written.

In an analogous manner, switches of the type described with reference to FIG. 7 can be designed in a switch arrangement.

The switch / display units of such arrangements can be equipped with resilient membranes, such as those which have been described with reference to FIGS. 5 to 7. In such arrangements, the membranes for each switch are preferably made from a single sheet, e.g. with individual blister structures 46 or 51 provided for each switch. When the membrane is designed with a conductive covering, as has been described with reference to FIGS. 6 and 7, a single covering can also be provided over the entire leaf surface.

Many changes are possible without leaving the scope of the invention. For example, in the case of the multiple arrangement of switch / display units, the two sets of electrodes 31 on the rear of the panel 30 can alternatively be arranged 20 vertically, in the manner shown in FIG. In the multiple arrangement of switch / display units of the type described above, the units can be multiplexed under the control of a microprocessor, as described in English Patent No. 2059657.

25 Finally, it should be pointed out that the drawings attached are only schematic representations.

They are not intended to indicate the relative dimensions and the particular thickness of the components. In a characteristic manner, the non-conductive panel 10 has a thickness in the order of 3 mm, the phosphor layer 13 has a thickness of 40% / iti and the various electrodes 11, 14, 20, 21, 31, 32 and the conductive layers 12, 33 one of rtt 0.05 / * s m.

Claims (9)

1.- switch / display unit, characterized by a transparent non-conductive panel (10), a first set of elongated parallel electrodes (11) formed from a transparent conductive material on the back of said panel 5, a phosphor layer (13), which is in contact with said first set of electrodes (11), a second set of parallel elongated electrodes (14) which are touch-mounted on the back of the phosphor layer (13), the second set of electrodes (14) is inclined relative to the first set of electrodes (11) so that the electrodes of one set overlap those of the other set, thereby forming a dot matrix, and through a transparent conductive layer (12) provided on the front side of the non-conductive panel (10) ), which covers the first set of electrodes (11). 2.- Switch / display unit according to claim 1, characterized in that the first set of electrodes (11) 'is divided into two groups (X, Y), wherein a group (X) 20 of reading electrodes is designed to with Means to be connected which gives read pulses to this group and the other group (Y) of sensor electrodes is designed to be connected to means to which sensing pulses are delivered. 25 3, - Switch / display unit according to claim 1, characterized in that the first set of electrodes (H) is designed to be connected to means which give this set of read pulses, and that one or more additional transparent Electrodes (20) are provided on the back 30 of the non-conductive panel (10), which lie under the transparent, conductive layer (12), the additional electrodes (20) being designed to be connected to means to which sensing pulses are emitted will. 35I 4.- Switch / display unit according to claims I 1 to 3, characterized in that the electrodes (11), which are designed to be connected to means for the purpose of reading pulses, are separated of those which are designed to be connected to means for sensing pulses by means of a guard electrode (21) which is designed to be connected to the earth. 5. Switch / display unit according to claims 1 to 4, characterized in that the transparent conductive layer (12) is provided on the front of the non-conductive panel (10). 6, - switch / display unit according to claim 5, characterized in that a transparent elastic conductive membrane (40) covers the conductive layer (12) and is at a certain distance therefrom. 7. Switch / display unit according to claim 6, characterized in that a transparent elastic non-conductive 15 de membrane (45) covers the conductive layer (12) and is at a certain distance therefrom, this membrane (45) on it the side facing the conductive layer (12) has a transparent conductive covering (48). 8. Switch / display unit according to the claims 2. Ibis 4, characterized in that the transparent conductive layer (52) is located at a certain distance from the front of the non-conductive panel (10) and can be moved in contact with the latter. 9.- Switch / display unit according to claim 8, characterized in that the transparent conductive layer (52) is located on the back of a transparent conductive elastic membrane (50) which covers the non-conductive panel (10) and separated from it is. 10. Multiple arrangement of switch / display units 30 with the configuration according to claims 1 to 9, characterized in that the switch / display units are attached separately, but with a mutual relationship, to a common non-conductive panel (30). 11. Multiple arrangement of switch / display units, 35 according to claim 10, characterized in that a first set of electrodes (31) is present together for a plurality of switch / display units. JI 12.- switch / display assembly according to claims f * «-13- 1 to 11, characterized in that it comprises means for applying lighting pulses individually to each electrode of the first set of electrodes (11) and to each electrode of the second set of electrodes (14), means for applying reading pulses to a group of the first set of electrodes (11), means for sensing pulses which are capacitively transmitted through the conductive layer (12) to one or more other electrodes (11, 12) at the back of the non-conductive * panel (10). 10 13.- Switch / display assembly according to claim 12, characterized in that the means for applying individual lighting pulses to each electrode of the first set of electrodes (11) also serve to simultaneously give a group of these electrodes read pulses. - »4f