Switching element with tactile and/or acoustic feedback

The present invention relates to switches which, when being activated, provide an acoustic and/or tactile feedback.

Switches come currently in many forms and shapes and for very different uses. However, only two main approaches are being followed:

The first approach is the use of a classical mechanical switch, which needs to be pressed with a defined force. The element pressed by the user directly actuates a mechanical switch or microswitch, which in turn creates the electric contact desired. The mechanical resistance of the mechanical switch intrinsically provides both a mechanical feedback resulting from the resistance of a spring-like element and an acoustic feedback often in the form of a "clicking" sound. However, such mechanical switches are often prone to failure due to the fact that mechanically moving parts that provide for the electrical connection are subject to wear. Other disadvantages are the large mounting depth of these switches, and the fact that these switches are exposed to vandalism.

A further approach is the use of a sensitive switch. In this case the actuation of the switch does not involve any mechanical movement and the actuation of the switch by the user does not result in any significant movement or deformation of the surface of the switch. Such switches are either based on so called "touch panels" or similar touch sensitive surfaces which in turn translate a touch of the user to an electrical signal. However, even if they are not prone to wear and mechanical failure, these sensitive switches have the major drawback that they do not provide necessarily an intrinsic acoustic or a mechanical feedback confirming the actuation of the switch, causing frustration of the user or repeated activation of the switching element until some result is finally perceptible. If in some cases a feedback is provided with an additional speaker, for instance with an artificially generated feedback sound, the complexity of the switches increases. Such sensitive switches exhibit typically an interrupter comprising an

electrical, electromagnetic or magnetic field and/or an emitter of electromagnetic waves, whereby for example a finger changes the electrical, electromagnetic or magnetic field and/or the electromagnetic waves in the interrupter, in order to obtain a signal. Such sensitive switches can be defined as contactless switches, since a direct mechanical contact between the switch and the finger is not necessary for the activation of the switch. The electromagnetic field of the interrupter is already disturbed when a finger approaches the interrupter without touching it.

EP 1598298 Al discloses an operating panel for use in elevators. Mechanical push buttons are mounted onto existing touch screen panels in order to modernize or update car operating panels.

The object of the present invention is thus to provide a switch not prone to wear even in extensive use and with a shallow mounting depth that at the same time provides tactile or acoustic feedback letting the user be aware that the switch has been activated.

SUMMARY OF THE INVENTION

The above identified objects are achieved by a switch based on the disturbance of an electromagnetic field with an interaction means, which provides the "feel" of a classical push-button. The interaction means is mechanically separated from the interrupter, which in turn provides an activation signal in response to the activation of the interacting means .

The above-mentioned separation of the interaction means from the interrupter is made possible with the employment of a converter acting as an interrupter, which translates the movement of the interaction means into a signal. According to the present invention said converter is based on the disturbance of an electromagnetic field.

This mechanically separated arrangement allows the switching element to provide both the advantages of a mechanical switch and the advantages of a sensitive switch, but at the same time eliminates the disadvantages of both, i.e. the switching element provides

acoustic and tactile feedback, similar to a mechanical switch, and at the same time offers the reliability of a sensitive switch by achieving the electrical switching by the interrupter, without mechanically moving parts.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention are described in detail by means of the following description and by reference to the drawings, in which:

Fig. IA shows a side view of a first embodiment of the switching element in a resting position;

Fig. IB shows a side view of the first embodiment of the switching element in an activated position;

Fig. 2A shows a side view of a second embodiment of the switching element in a resting position;

Fig. 2B shows a side view of the second embodiment of the switching element in an activated position;

Fig. 3A shows a side view of a third embodiment of the switching element in a resting position;

Fig. 3B shows the side view of the third embodiment of the switching element in an activated position;

Fig. 3C shows a side view of a fourth embodiment of the switching element in a resting position;

Fig. 3D shows a side view of the fourth embodiment of the switching element in an activated position;

Fig. 4A shows a side view of a fifth embodiment of the switching element in a resting position showing a light emitting device, disturbing means and a light detector;

Fig. 4B shows a side view of the fifth embodiment of the switching element in an activated position showing the light beam

between the light emitting device and the light detector being interrupted by the disturbing means;

Fig. 5 shows a front view of an embodiment of an operating panel comprising a multitude of switching elements;

Fig. 6A shows a front view of a further embodiment of an operating panel comprising a multitude of switching elements;

Fig. 6B shows a side view of another embodiment of an operating panel comprising a multitude of switching elements;

Fig. 7A shows a side view of a further embodiment of the switching element in a resting position;

Fig. 7B shows a side view of a further embodiment of the switching element in an activated position;

DESCRIPTION OF PREFERRED EMBODIMENTS

Figure IA depicts a side view of a first embodiment of the switching element 10 based on the disturbance of an electromagnetic field in a so called resting position. As shown here, the switching element 10 comprises a mounting part 13, a back support 15, an interaction means 11 and resetting means 14 which provides a resetting force for resetting the interaction means 11, after being activated, into the initial resting position. The switching element 10 further comprises a so called converter which translates the movement of the interaction means 11 into a signal. This signal is then interpreted to cause an electrical contact, i.e. to achieve the actual role of the switching element 10. Accordingly, this converter is an interrupter 16 interacting with the interaction means 11 in such a way that a signal is produced when the interaction means 11 is moved with respect to the mounting part 13.

Figure IB shows a side view of a first embodiment of the switching element 10 based on the disturbance of an electromagnetic field in a so called activated position, i.e. the interaction means 11 is moved with respect to the mounting part 13, said movement being caused by

the user who has "activated", i.e. pushed the interaction means 11. This action is perceived by the user exactly as is pushing a classical mechanical button or switch. This perception relates to the tactile feedback, a dislocation of the activated part of the button, and the audible feedback, like a "clicking" sound, that one can perceive when activating a classical mechanical switch. Accordingly, the user is aware that the switch has been activated/ pushed and that the required action is performed in response. With reference, for example, to the call button of an elevator, the user should preferably get some sort of feedback confirming that the button has been pushed and the elevator will respond to the call i.e. an elevator car is coming. Several other situations are possible where the user needs direct confirmation that a switch has been activated. It is important that the current invention is intended to provide the above mentioned tactile and audible feedback without the employment of any additional devices like a speaker for an audible feedback.

As shown in Figure IB, the activation of the outer surface 11.1 of the interaction means 11 causes a dislocation of the interaction means 11 with respect to the mounting part 13. This dislocation causes an interaction between the interaction means 11 and the interrupter 16, which will translate this dislocation into a signal. The interrupter 16 thus acts as a converter.

Preferred embodiments of the present invention further comprise a resetting means 14 which is additionally employed in order to provide a resetting force for resetting the interaction means 11 into the resting position shown on Figure IA, after being activated and thus displaced into the position shown on Figure IB. The resetting means 14 is preferably a spring-like element 14 which is deformed when the interaction means 11 is dislocated in relation to the mounting part 13. Due to this deformation of the spring-like element 14, a resetting force arises and the interaction means 11 is reset to the original resting position. In the preferred embodiment the resetting means 14 is designed such that when deformed due to the user pressing against the outer surface 11.1 of the interaction means 11, a "clicking sound" is emitted by the spring-like element

14. This provides the acoustic feedback described before. The tactile feedback is provided when the interaction means 11 is reset by the spring-like element 14.

Figure IA and IB show a first embodiment of the switching element 10 with the interaction means 11 implemented as a lever that tilts around an axis 12. The interaction means 11 is shown as positioned at the two endpoints in Figure IA and Figure IB, respectively. The amount of displacement of the interaction means 11 is variable according to the specific needs of the specific area of application and the illustrations are not supposed to limit the subject-matter of the present invention to the tilting lever arrangement.

Figures 2A and 2B show a further embodiment of the switching element 10 where the interaction means 11 is mounted to "float" in the mounting part 13. This is achieved by mounting the interaction means 11 using flexible mounting elements 19. The flexible mounting element 19 is made either from a flexible rubber band, a harmonica style membrane or other similar arrangements that allow a smooth lateral movement of the interaction means 11.

By mounting the interaction means 11 with the above mentioned flexible mounting elements 19 symmetrically, the displacement of the interaction means 11 will occur laterally, preferably roughly parallel to the back support 15 of the mounting part 13. Figure 2A shows the interaction means 11 of the switching element 10 in the resting position, whereby Figure 2B shows the interaction means 11 in an activated position, when it is laterally displaced in relation to the mounting part 13 as a consequence of the user exercising a pressure against an outer surface 11.1 of the interaction means 11.

Figure 3A to 3D show two further embodiments of the switching element 11 that further comprises a spring 17 serving as resetting means 14. Additionally, this spring 17 can also serve the purpose of providing a mechanical acoustic signal providing a confirmation to the user that the switching element 10 has been activated.

Figure 3A and 3B show an embodiment where the additional spring 17 is a coil spring 17 that provides an additional resetting force on

the interaction means 11. This additional resetting force is preferably perpendicular to the outer surface 11.1 of the interaction means 11. Figure 3A shows the switching element 10 with the coil spring 17 in a resting position and Figure 3B shows the same embodiment in an activated position where the coil spring 17 is compressed due to the dislocation of the interaction means 11 caused by the user pressing against the outer surface 11.1 of the interaction means 11.

Figure 3C and 3D show an alternative embodiment of the switching element 10 with a spring 17. In this embodiment the additional spring 17 is a leaf spring with a fixed end 17.1 and a sliding end 17.2. Figure 3C shows the switching element 10 with the leaf spring 17 in a resting position. In this position the leaf spring 17 is curved inward as observed from the back support 15. When the interaction means 11 is dislocated, as shown in Figure 3D, the leaf spring 17 is deformed, with the sliding end 17.2 sliding outwards, roughly perpendicular to the direction of the dislocation of the interaction means. At the moment when the leaf spring 17 is deformed to an extent where the leaf spring 17 starts to curve outwards, as observed from the back support 15, the acoustic feedback in the form of a "clicking sound" is emitted by the leaf spring as a response to its deformation.

According to the present invention, several approaches are possible to accomplish the interrupter 16. One should note that the specific interrupter 16 used does not affect the inventive concept of the switching element 10, i.e. the mechanical separation of the interrupter 16 and the interaction means 11. For this reason each specific interrupter 16 is suitable to be employed in all embodiments of the switching element 10 presented in previous paragraphs in relation to the figures depicting these embodiments.

One possible approach for the interrupter 16 is an emitter of a light beam which is being disturbed or interrupted when the interaction means 11 is moved with respect to the mounting part 13. In order to achieve this, in a preferred embodiment of the switching element 10, a light emitting device 16.1, for example an LED is used

in connection with a light detector 16.2 as shown in Figure 4A. A disturbing means 16.3 connected to the interaction means 11 is employed to disturb the light beam between the light source 16.1 and the light detector 16.2, as depicted in Figure 4B, when the interaction means 11 is moved with respect to the mounting part 13.

A second approach for the interrupter 16 is an interrupter 16 which emits a magnetic or electric field that is being disturbed when the interaction means 11 is displaced in relation to the mounting part 13 in response to the user exercising pressure on the outer surface 11.1 of the interaction means 11.

This can be achieved by fixing a capacitor having two parallel plates on the back support 15 and fixing a dielectric material on the interaction means 11 in such a way that, when the interaction means 11 is dislocated towards the back support 15, the dielectric material is introduced between the plates of the capacitor, thus modifying its capacitance.

A similar solution is the use of an inductor in connection with a permanent magnet attached to the interaction means 11 in such a way that, when the interaction means is dislocated towards the back support 15, the permanent magnet is introduced into the inner part of the inductor, thus inducing electrical current in it. This specific embodiment allows the detection of the exact amount of dislocation of the interaction means 11 or even the speed of this dislocation by measuring the amount of induced current in the inductor. This can be advantageous when a potentiometer or the like is to be constructed instead of an on/off switch.

Figure 5 shows an operating panel 20 comprising a multitude of switching elements 10. The particular operating panel 20 depicted on this figure is intended to be used e.g. in an elevator cabin. Such panels 20 may comprise a display 3 among other elements.

A further variation of an operating panel 20 comprising a multitude of switching elements 10 according to the present invention is depicted in Figures 6A and 6B. The operating panel 20 presented in these figures is suitable to be operated by visually impaired people

due to the fact that the outer surface 11.1 of the interaction means 11 of each switching element 10 is fitted with Braille codes besides other engravings. Figure 6A shows a front view of this further embodiment of the operating panel 20.

Figure 6B shows a side view of an operating panel 20. One can observe that the switching elements 10 protrude from the surface of the operating panel 20, providing an exactly similar appearance as a classical mechanical switch.

In Figures 7A and 7B, a further embodiment of the present invention is shown. The interrupter comprises an interrupter emitter and sensor 16.4 and an interrupter field 16.5. The interrupter emitter and sensor 16.4 is mounted on the back panel 15. The interrupter emitter and sensor 16.4 is located on the opposite side of the back panel 15 than the interaction means 11. This ensures that electronic components in the interrupter emitter and sensor 16.4 are shielded by the back panel from vandalism or harmful environmental influences such as water or dust.

The interrupter emitter and sensor 16.4 emits a field 16.5, which extends across the back panel 15 and towards the interaction means 11. When the interaction means 11 is moved from a passive state

(Figure 7A) to an active state (Figure 7B) , the interaction means 11 interferes with the interrupter field 16.5. A change in the interrupter field 16.5 caused by said interference is sensed by the interrupter emitter and sensor 16.4 and converted into a signal representative of the activation state (active state as shown in

Figure 7A or passive state as shown in Figure 7B) of the switching element 10.

One should note that these figures are merely exemplifications of particular uses of the switching element 10 and that the use of the present invention is not limited to the examples presented herein.