FI82332B - MIKROMEKANISK ANROPSTRYCKKNAPPSTATION. - Google Patents

Description

82332

MICROMECHANICAL CALL BUTTON STATION - MIKROMEKANISK ANROPSTRYCK-KNAPPSTATION

The present invention relates to a micromechanical call button station according to the preamble of claim 1, in particular for elevator operation.

Different traditional mechanical pushbuttons and nowadays also electronic touch buttons are used as different pushbuttons. The mechanical push switch consists of a button, a spring transmitting the printing information and metal contacts. The pushbutton can be either opening or closing. An indicator light is sometimes attached to a mechanical weight switch to indicate the status of the switch. In the past, LEDs were incandescent bulbs, but now LEDs are used.

Electronic Touch Switches usually measure the capacitance between the switch and the ground plane. A change in capacitance causes the switch to tune. Switches of this type have no moving parts, so in principle they are more reliable than the corresponding mechanical push-button switches.

A weakness of mechanical pushbuttons, like other electromechanical switches, is their poor durability in continuous use. Mechanical pushbuttons also require a relatively long pressing movement. The reliability of touch buttons is impaired by their sensitivity to static electricity discharges. It is quite common for a capacitive touch button to tune itself in a room with a synthetic fiber carpet. In addition, both the mechanical push button and the electronic touch button consist of several components that can be assembled separately.

Current microcircuit technology is capable of fabricating very small pressure sensors whose pressure change detection is based on reversible deformation of the material. Such sensors are very reliable and dependable. For the purposes of this invention, the object is to provide a weight switch which does not have the above-mentioned disadvantages by applying this technique. The pushbutton switch according to the invention is thus mainly characterized by what is stated in the characterizing part of claim 1.

The invention is thus based on machining and forming a micromechanical switch on the silicon chip, after which the necessary electronics are integrated on the same chip. The execution order can also be reversed or simultaneous. The electronics can include both analog and digital technology and can be implemented with any known integrated circuit manufacturing technique (e.g. CMOS).

The integrated pushbutton switch thus obtained is compact and reliable, and can be made so intelligent if desired that, for example, installation and maintenance work is facilitated and that the idea of decentralizing control is realized. The pressure switch according to the invention is not sensitive to static electricity discharges and is well suited for mass production. For convenience, the micromechanical push button is at the level of a traditional touch button.

A preferred embodiment of the pushbutton switch according to the invention is characterized in that the switch member consists of a capacitive pressure capacitor type of a capacitor type known per se, machined into a silicon body. The switch in this case is therefore based on monitoring the change in capacitance.

Another preferred embodiment of the pushbutton according to the invention is characterized in that the coupling member consists of a thin region machined into the silicon body in a manner known per se, at the edges or in the center of which impurity atoms are processed to form a strain gauge bridge. is integrated. Tensile strip; · 'bridge can be based on the so-called. piezoresistive phenomenon, and the process

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The 3,82332 ringing can be performed in a known manner by diffusion or ion implantation. In this case, pressing the button will cause the stretch strip bridge to become unbalanced.

The switch is particularly well suited for use in elevators, where a switch located on the floor level registers external calls and a switch located in the elevator car internal inputs, and further feeds data to the elevator control system and controls the LEDs indicating the status of the elevator.

Other preferred embodiments of the invention are characterized by what is set out in the claims below.

In the following, the invention will be explained in detail by means of examples with reference to the accompanying drawings.

Figure 1 shows the principle of a weight switch according to an embodiment of the invention,

Figure 2 shows the principle of a push switch according to another embodiment of the invention,

Figure 3 shows a side view of a push switch according to the invention,

Figure 4 shows a block diagram of an elevator call button system implemented in accordance with the invention,

Figure 5 shows a practical embodiment of the call button system according to Figure 4.

Figure 1a shows the principle of a capacitive pressure sensor. The silicon chip 1 is machined with a double-sided constriction 2, which forms one of the capacitor plates. A second similarly machined (not drawn) or smooth capacitor plate 3 is connected to the above so that air or a vacuum is left in the space 4 4 82332 between them. The silicon wafers 1 and 3 are insulated at the capacitor by an insulating layer 5. In the capacitor thus obtained, the changes in pressure bring the capacitor plates closer or further apart, thereby changing its capacitance. Figure 1b shows a surrogate connection of the structure of Figure 1a.

Figure 2a shows the surface pattern of the piezoresistive resistor bridge 6. The bridge is processed on a silicon wafer by diffusion or ion implantation. At the resistor bridge 6, it is advantageous to apply a constriction similar to that shown in Fig. 1a to the silicon wafer. In sleep mode, all bridge resistors R1-R4 are equal. When pressure is applied to the silicon wafer, stresses and strains are created in the structure. In this case, according to the piezoresistive phenomenon, the resistance characteristics of the resistors R1-R4 change in proportion to the mechanical stresses prevailing therein, whereby the resistor bridge 6 becomes unbalanced, which can be measured in a known manner to find out the magnitude of the pressure. Figure 2a shows the surrogate connection of the bridge 6.

Figure 3 shows a pushbutton according to the invention with a front plate 7 to which a flexible printing film 8 is attached. Under the membrane 8 there is a pressure limiter 9 which prevents overpressure from entering the silicon pressure sensor and a pushbutton hybrid circuit 10 attached to the pressure limiter 9. The switch operates via a printing film 8, e.g. to a capacitive silicon pressure sensor located in the hybrid circuit 10. The sensor-controlled electronics in the circuit then perform the necessary steps to generate the switching operation and to pass on the printing information, as described in the example below.

Figure 4 shows a block diagram of a pushbutton system for elevator operation with the following main components: capacitive or piezoresistive silicon pressure sensor 11, pressure measuring electronics 12, intelligent holding and connection logic 13, light emitting diode 15 controller 14 and elevator connection adapter 16.

5,82332

The latch circuit 13 registers the call and its communication logic sends information about it in serial or parallel format via the interface adapter 16 to the elevator control system 17, whereby the elevator control system accepts / rejects the call and sends an acknowledgment back via the interface adapter 16 to the latch and connection logic 13. , the light emitting diodes 15 are switched on via the light emitting diode controller 14. After serving the call, the control system sends the call delete command via the interface adapter 16 to the hold and connection logic 13.

Figure 5 shows a practical application of the push switch system according to Figure 4. This is a floor-mounted elevator call button station consisting essentially of two pushbuttons 18 and two arrows 19 indicating the direction of the registered call. The base may also consist of a sheet of other durable insulating material, such as epoxy. The switch itself is marked with a reference 22, in the middle of which a pressure sensor 23 stands out. The electronics integrated on the same silicon piece as the pressure sensor are not drawn, nor is the pressure limiter of the switch. The arrow pattern 19 assembled from the LEDs is mounted on the same ceramic base 21 as the push switch 22. Reference 24 is a supply voltage filter that removes the ripple and interference spikes from the switch supply voltage, and reference 25 is a connector through which the call button station communicates with the elevator control system. When one of the two pushbuttons 20 is pressed, the corresponding LED arrow 19 lights up after the elevator control system first accepts the call and measures are taken to serve it.

It will be clear to a person skilled in the art that the invention is not limited to the above-mentioned exemplary embodiments, but can be modified within the scope of the appended claims.

Claims (3)

6 82332 A micromechanical call button station, in particular for elevator operation, wherein the micromechanical pressure sensor provided on the silicon chip acts as a switching element (2,3; 6) at least partially formed on the same silicon chip (1) on which the switching information receiving and interpreting electronics (12,13,16) are integrated, characterized in that one or more switching elements (2,3; 6) are arranged as a call button on the floor levels for registering the external calls of the elevator and its internal calls in the elevator car and feeding them to the elevator control system so that each switching element (23) and its electronics (12,13,16 ) is mounted on a suitable substrate, such as a ceramic or epoxy-based plate (21), to which call-indicating LEDs (19) are also connected. Call button station according to claim 1, characterized in that the switching element consists of a capacitive pressure sensor of the vacuum or air-insulated capacitor type known per se machined into a silicon body, wherein at least a thin capacitor plate (2) bending by the call button is the same , 16) is integrated. A call button station according to claim 1, characterized in that the switch member consists of a thin region machined into the silicon body in a manner known per se, at the edges or in the center of which impurity atoms are processed to form an elongation strip bridge (6). 12,13,16) is integrated. h 7 82332