AU2007260231A1

AU2007260231A1 - Circuit arrangement and method for controlling a drive for an adjustable table top

Info

Publication number: AU2007260231A1
Application number: AU2007260231A
Authority: AU
Inventors: Walter Koch
Original assignee: Logicdata Electronic and Software Entwicklungs GmbH
Current assignee: Logicdata Electronic and Software Entwicklungs GmbH
Priority date: 2006-06-12
Filing date: 2007-06-12
Publication date: 2007-12-21
Also published as: WO2007144145A2; CA2654702A1; WO2007144145A8; DE102006027437A1; WO2007144145A3

Description

PUBLISHED SPECIFICATION VERIFICATION OF TRANSLATION I, ...D r. V e it K a fka ................................................................. (insert translator's name) of ...... Epping Hermann Fischer Patentanwaltsgesellschaft mbH.... ............... ......... Ridlerstr. 55, 80339 Munich, Germany.................................. (translator's address) declare as follows: 1. That I am well acquainted with both the English and German languages, and 2. That the attached document is a true and correct translation made by me to the best of my knowledge and belief of: (a) The specification of International Bureau pamphlet numbered WO 2007/144145 International Application No. PCTIEP2007/005179 6q.42-269 it Z ............................ .. a.;?.......................... i' ; ; o ; ;i,............. (Date) (Signature of T nslator) (No witness required) PCT/EP2007/005179 - 1 Description Circuit arrangement and method for controlling a drive for an adjustable table-top 5 The invention concerns a circuit arrangement and method for the control of a drive for an adjustable table-top. A large number of tables, particularly writing desks with 10 adjustable tops on which the height of the table-top can be adjusted by means of a special drive are offered nowadays. A variety of operating elements are provided to actuate the height adjustment. The operating elements are connected through a cable to a drive unit for driving the table-top. 15 The operating elements may, for instance, be mounted underneath the table-top at the front edge of the table, or are glued around the front edge of the table. The intention is to give the user easy access, whilst at the same time 20 permitting the cable to be laid underneath the table-top, since the drive controller is usually located below the table-top. The user frequently finds this operating position to be impractical, but due to the cable connection to the drive controller it cannot be flexibly changed. 25 Frequently, operating elements are fitted in locations on the table or the table-top or in a hole or depression in the table-top. This, however, requires mechanical work on the table-top, in particular so that the cable can be passed from 30 the top to the underside of the table-top. An object of the invention is to provide a circuit arrangement and method with which a drive for an adjustable PCT/EP2007/005179 - 2 table-top can be controlled at low cost and without the need for mechanical work on the table-top. This object is achieved with the subject-matter of the 5 independent patent claims. Implementations and further development of the invention are subject-matter of the dependent claims. One embodiment of a circuit arrangement for controlling a 10 drive for an adjustable table-top comprises an operating unit and an evaluation unit. The operating unit comprises at least one activation element by means of which a state of the operating unit can be changed. The evaluation unit comprises a sensor unit for wireless detection of the state of the 15 operating unit. Furthermore, the evaluation unit includes a control terminal from which a control signal can be output to a drive controller depending on the state that is detected. For instance, the at least one operating element can change a 20 magnetic field that acts on the evaluation unit, while the sensor unit comprises at least one magnetic field sensor for detection of the magnetic field. This makes it possible for the operating unit and the 25 evaluation unit to be mounted on the table-top independently of one another. It is possible to control the table-top drive without mechanical work on the table-top being essential. As a result of the wireless acquisition of the state of the operating equipment it is possible, for instance, for the 30 operating equipment to be attached above the table-top while the evaluation unit, which can be connected to the drive controller by cable, can be attached underneath the table top.

PCT/EP2007/005179 - 3 In one embodiment of a method for controlling a drive for an adjustable table-top, a state of an operating unit is influenced by activating at least one activation element on 5 the operating unit, as a result of which the activation also changes a magnetic field acting on the evaluation unit. The state of the operating unit is detected wirelessly in an evaluation unit, whereby the detection also detects the magnetic field. A control signal can be derived from the 10 state that is detected. This control signal is ultimately passed on to a drive controller. This method has the favourable consequence that an activation element can be activated above the table-top, while the 15 evaluation of the resulting changed state of the operating unit can take place through wireless acquisition underneath the table-top. The principle upon which this is based also allows a circuit 20 arrangement, particularly the operating unit, to be flexibly located in the area of the table-top, for instance at a convenient position in the working area of the table-top. The invention is explained below using several embodiments 25 with reference to the drawings. Elements having the same function or effects are given the same reference signs. They show: 30 Figure 1 a first embodiment of a proposed circuit arrangement, Figure 2 a second embodiment of a circuit arrangement, PCT/EP2007/005179 - 4 Figure 3 a first embodiment of an operating unit, Figure 4 a third embodiment of a circuit arrangement, 5 Figure 5 a fourth embodiment of a circuit arrangement, Figure 6 a second embodiment of an operating unit and 10 Figure 7 a fifth embodiment of a circuit arrangement. Figure 1 illustrates an embodiment of a circuit arrangement for controlling a drive. An operating unit 1 is provided here with an activation element 11 that is positioned above a 15 table-top 3. Below the table-top 3, underneath the operating unit 1, an evaluation unit 2 is positioned, comprising a sensor unit 21 to which a sensor coupler 29 is attached. A drive controller 100 is connected through a control terminal 20 of the evaluation unit 2 to the sensor coupler 29. The 20 operating unit 1 and the evaluation unit 2, which are substantially parallel to one another, are separated by the table-top 3. By activating the activation element 11, a state of the 25 operating unit 1 is affected or changed. The operating unit 1 may be able to adopt a number of different states. For instance, activating the activation element 11 may change the operating unit 1 from a first state into a second state. 30 The operating unit 1 and the evaluation unit 2 can be coupled together in a variety of ways. The coupling can, for instance, be achieved through a magnetic field, in particular a static magnetic field. Coupling can also be achieved PCT/EP2007/005179 - 5 through an alternating electromagnetic field. A change in the state of the operating unit 1 can thus, for instance, be achieved through a change in the properties of the static magnetic field. An electromagnetic field can be changed by 5 changing the inductive and/or capacitive properties of the operating unit 1. These changes in state can be recorded or detected by the sensor unit 21, and can be converted by the sensor coupler 29 10 into appropriate control signals for the drive controller 100. The state of the operating unit 1 is detected through the table-top 3 without wires, i.e. without a cable connection between the operating unit 1 and the evaluation unit 2. 15 Figure 2 illustrates a further embodiment of a circuit arrangement for controlling a drive. The evaluation unit 2 comprises here at least one magnetic field sensor 22 in the sensor unit 21. This is used to detect a magnetic field that 20 is acting on the evaluation unit 2. The magnetic field sensor 22 can, for instance, be implemented using a Hall sensor, or may comprise a Hall sensor. A Hall sensor supplies a voltage that depends on a magnetic field that is present at the Hall sensor. When the magnetic field changes, the voltage at the 25 Hall sensor therefore also changes. From this change in voltage, which results from the change in the state of the operating unit 1, a control signal can be derived for a drive controller 100. 30 The magnetic field sensor can also comprise other elements that are affected magnetically such as, for instance, magneto-resistive elements or magnetic diodes.

PCT/EP2007/005179 6 In this embodiment, the operating unit 1 comprises a magnet Ml implemented, for instance, in the form of a permanent magnet. The magnetic field from the magnet M1 can be detected wirelessly by the magnetic field sensor 22. By means of the 5 activation element 11, the operating unit 1 can, for instance, be mechanically moved across the table-top 3, as a result of which there is a change in the magnetic field acting at the evaluation unit 2. A movement can, for instance, be made directly a long a line of movement, or may 10 also consist of a rotary movement of the operating unit 1 on the table-top 3. It is also possible for the magnetic field sensor 22 to be designed in such a way that it detects a magnetic field that 15 acts on the evaluation unit 2 at several locations on the evaluation unit 2, in order, for instance, to be able to detect several different magnetic states of the operating unit 1. From a number of different states it is thus possible to derive a number of different control signals and to pass 20 them on to the drive controller 100. Figure 3 illustrates an alternative embodiment of an operating unit 1, in which a magnetic state of the operating unit 1 can be changed. In this embodiment, activation of the 25 activation element 11 can close a switch Sl. The switch Sl is wired into an electrical circuit having a source of voltage Vl and a coil L1. The source of voltage Vl represents a source of electrical power. 30 Closing the switch S1 creates an electrical current through the coil L1. If the source of voltage V1 is a DC source, the flow of current through the coil L1 will generate a magnetic field for a certain time, the length of time depending on the PCT/EP2007/005179 - 7 inductance and the electrical resistance of the coil L1. The change in state of the operating unit 1 can be determined from the change in the magnetic field or by the generation of the magnetic field, by means of a magnetic field sensor 22 5 not shown here. If the voltage source Vl is implemented as a source of alternating voltage, a magnetic field will be generated continuously by the coil L1 while the switch is closed. This 10 magnetic field can also be detected by a magnetic field sensor 22. The operating unit 1 can also comprise several magnets or coils for the generation of magnetic fields, and these, 15 through the activation of a number of activation elements, can generate and/or affect a magnetic field acting at the evaluation unit 2. Figure 4 illustrates a further embodiment of a circuit 20 arrangement for controlling a drive. In this embodiment, the sensor unit 21 comprises a resonant circuit 40 comprising a source of power 4, a capacitor C4 and a coil L4 that acts as an antenna. The operating unit 1 comprises a first and a second operating element 11, 12, as well as two resonant 25 circuits 42, 43, that are constituted respectively by a capacitive element C2 and a coil L2 and by a capacitive element C3 and a coil L3. The switches S2, S3, that are activated by the activation elements 11, 12, can electrically close the passive resonant circuits 42, 43. 30 The resonant circuit 40 radiates an alternating electromagnetic field through the coil L4, which acts as an antenna. Depending on the state of the operating unit 1, in PCT/EP2007/005179 8 other words on a state of the switches S2, S3, the electrical properties of the resonant circuit 40 can be affected. When switches S2, S3 are open, the associated resonant circuits 42, 43 cannot respond; in other words the associated resonant 5 circuits 42, 43 do not include an effective inductance. By closing the corresponding switches S2, S3 by means of the associated activation element 11, 12, an inductance value is thus changed. Because the state of the operating unit 1 depends on the value of the inductance, the state of the 10 operating unit 1 also changes. Closing one of the resonant circuits 42, 43 affects the electrical properties of the resonant circuit 40. This can be detected in the evaluation unit 2, and can be used to derive 15 a control signal to be output at the control terminal 20. Through suitable tuning of the resonant circuits 42, 43 through an appropriate selection of the values for the coils L2, L3 and of the capacitive element C2, C3 the electrical 20 properties of the resonant circuit 40 can be changed in different ways according to whether resonant circuit 42 or 43 is activated. As a result, different control signals can be derived. 25 The operating unit 1 and the evaluation unit 2 can thus be coupled by means of an electromagnetic field. The coils L2, L3 function as antennae, and can be switched in or out by means of the activation element 11, 12. By switching the antennae in or out, the electromagnetic field can be affected 30 or changed. Alternatively, the evaluation unit 2 may also comprise a number of antennae or coils, two for instance, positioned PCT/EP2007/005179 - 9 next to one another. In this example, the operating unit comprises three antennae, of which one is permanently active and is located in the area of the electromagnetic fields of the antennae of the evaluation unit, for instance in a 5 position centrally above the two antennae of the evaluation unit 2. The second and third antennae of the operating unit can be positioned in such a way that each of these antennae is positioned in the primary region of action of the electromagnetic field of one of the antennae of the 10 evaluation unit. The second and third antennae of the operating unit can each be activated by one of the activation elements 11, 12. In this way the activation of different activation elements 11, 12 can easily be distinguished. 15 Figure 5 illustrates a further embodiment of a circuit arrangement for controlling a drive. The sensor unit 21 in turn comprises a resonant circuit 40. The operating unit 1 comprises identification circuits ID2, ID3 that can be activated by the switches S2, S3 operated by the activation 20 elements 11, 12. The identification circuits ID2, ID3 can, for instance, consist of circuits 102, 103 or of chips, such as are familiar from contact-free identification cards. These are 25 also known as Radio Frequency Identification (RFID) systems. An identification circuit ID2, ID3 activated by a closed switch S2, S3 has an effect on an electromagnetic field generated by the resonant circuit 40 or on a high-frequency 30 signal transmitted by the resonant circuit 40. The identification circuit can modulate the signal or change it in some other way. The identification circuits ID2, ID3 change the signal, or the electromagnetic field, in different PCT/EP2007/005179 - 10 ways, so that activation of the different activation elements 11, 12 can be distinguished. If an identification circuit ID2, ID3 is not activated by closing the corresponding switch S2, S3, the electromagnetic field or the signal transmitted 5 by the resonant circuit 40 is not affected. A change caused by one of the identification circuits ID2, ID3 is detected in the resonant circuit 40, and a corresponding control signal is derived from it. In an 10 alternative embodiment, the evaluation unit 2 can comprise a reading device for contact-free identification cards. Figure 6 illustrates an embodiment of an operating unit 1 with an identification circuit ID2. A power supply for the 15 identification circuit ID2 is provided here by an arrangement 50 for generating a supply voltage, comprising a coil L5, capacitive elements C5, C6 and a diode D5. A signal transmitted by the resonant circuit 40 is received by the coil L5. This signal, which is usually an alternating signal 20 with a high frequency, is rectified by the diode D5 and used to charge up the capacitive element C6. The capacitive element C6 serves to store the charge, and provides a supply of power for the identification circuit ID2. Alternatively, a different source of voltage, such as a battery, may also be 25 used. Figure 7 illustrates a further embodiment of a circuit arrangement for controlling a drive. The evaluation unit 2 again comprises a resonant circuit 40, in which a capacitive 30 element in the resonant circuit 40 consists of capacitor plates P41, P42 positioned adjacent to one another. An electrical field between the plates P41, P42 also passes through the operating unit 1 with the activation element 11.

PCT/EP2007/005179 - 11 When the activation element 11 is activated, for instance by placing a finger on or close to the activation element 11, the properties of the electrical field, or the capacitive properties of the operating unit, are changed or affected. 5 The state of the operating unit thus, for instance, comprises the capacitive properties. As a result of the change in the capacitive properties, the value of the capacitance, for instance, of the capacitor that 10 consists of the plates P41, P42 changes, so changing the oscillation frequency of the resonant circuit 40. This change can be detected, and a control signal can be derived from it. The capacitor plates P41, P42 constitute, for instance, a capacitive proximity switch. The evaluation unit 2 can also 15 comprise other embodiments of capacitive proximity switches in order to detect changes in the capacitive properties of the operating unit 1. The operating unit 1, with the activation elements 11, can in this embodiment also consist of a simple adhesive label with no electrical function. 20 If a circuit arrangement in accordance with one of the embodiments comprises two activation elements 11, 12, it is typically possible to achieve two different functions for the drive controller, for instance that the table is moved to a 25 higher or to a lower position. The number of possible activation elements, however, is not in any way limited by this embodiment. Rather, it is possible for additional activation elements to be provided that can place the operating unit 1 into more states that can be evaluated. In 30 this way, additional actions can be carried out on the movable table-top, such as changing the inclination of the table-top.

PCT/EP2007/005179 - 12 Reference key 1 Operating unit 2 Evaluation unit 5 3 Table-top 11, 12 Activation element 20 Control terminal 21 Sensor unit 22 Magnetic field sensor 10 29 Sensor coupler 40, 42, 43 Resonant circuit 50 Means for generating a power supply 100 Drive controller SI, S2, S3 Switches 15 D5 Diode L1, L2, L3, L4, L5 Coil, antenna C4, C5, C6 Capacitive element Vl, V4 Power source M1 Magnet 20 ID1, ID2 Identification circuit P41, P42 Capacitor plate

Claims

1. Circuit arrangement for the control of a drive for an adjustable table-top (3), consisting of 5 - an operating unit (1), comprising at least one activation element (11, 12), by means of which a state of the operating unit (1) can be changed; and - an evaluation unit (2), comprising a sensor unit (21) for wireless detection of the state of the operating 10 unit (1) and a control terminal (20) through which, depending on the detected state, a control signal can be output to a drive controller (100); - where by means of the at least one activation element (11, 12) a magnetic field that acts at the evaluation 15 unit (2) can be changed, and the sensor unit (21 comprises at least one magnetic field sensor (22) to detect the magnetic field.

2. Circuit arrangement according to Claim 1, 20 in which the magnetic field sensor (22) comprises at least one Hall sensor.

3. Circuit arrangement according to Claim 1 or 2, in which the magnetic field can be generated and/or affected 25 by the at least one activation element (11, 12).

4. Circuit arrangement according to one of Claims 1 to 3 in which the sensor unit (21) comprises a resonant circuit (40) whose electrical properties can be affected by the state 30 of the operating unit (1).

5. Circuit arrangement according to Claim 4, PCT/EP2007/005179 - 14 in which an inductance value can be changed by the at least one activation element (11, 12), and the state of the operating unit (1) depends on the inductance value. 5

6. Circuit arrangement according to Claim 5 in which the operating unit (1) and the evaluation unit (2) can be coupled by an electromagnetic field, and where at least one antenna (L2, L3) can be switched into or out of the electromagnetic field by the at least one activation element 10 (11, 12).

7. Circuit arrangement according to one of Claims 4 to 6, in which the operating unit (1) comprises at least one identification circuit (ID2, ID3) that can be switched on or 15 off by the at least one activation element (11, 12) and by means of which the electrical properties of the resonant circuit (40) can be changed.

8. Circuit arrangement according to one of Claims 4 to 7, 20 where the capacitive properties of the operating unit (1) can be changed by the at least one activation element (11, 12), and where the state of the operating unit (1) includes the capacitive properties. 25

9. Circuit arrangement according to Claim 8, in which the sensor unit (21) comprises a capacitive proximity switch (P41, P42).

10. Circuit arrangement according to one of Claims 4 to 9, 30 in which the operating unit (1) comprises a means (50) for generating a supply voltage from a signal radiated by the resonant circuit (40). PCT/EP2007/005179 - 15

11. Circuit arrangement according to one of Claims 1 to 10, in which the operating unit (1) comprises at least one electrical power source (Vl). 5

12. Circuit arrangement according to one of Claims 1 to 11, in which the operating unit (1) is located above the table top (3) and the evaluation unit (2) is located underneath the table-top (3). 10

13. Circuit arrangement according to Claim 12, in which the evaluation unit (2) is located underneath the operating unit (1).

14. Method for controlling a drive for an adjustable table 15 top (3), comprising the steps of: - affecting a state of an operating unit (1) by activating at least one activation element (11, 12) of the operating unit (1), whereby the activation also changes a magnetic field that acts at the evaluation unit (2); 20 - wireless detection of the state of the operating unit (1) in an evaluation unit (2), whereby the detection also detects the magnetic field; - deriving a control signal from the detected state; - output of the control signal to a drive controller 25 (100).

15. Method according to Claim 14, in which the operating unit (1) and the evaluation unit (2) are coupled by an electromagnetic field, where the activation 30 changes the electromagnetic field, and where detection involves detecting the change in the electromagnetic field.

16. Method according to Claim 15, PCT/EP2007/005179 - 16 in which the activation switches at least one identification circuit (ID2, ID3) in or out, as a result of which the electromagnetic field can be changed. 5

17. Method according to one of Claims 14 to 16, in which activation changes the inductive properties of the operating unit (1), and where detection involves detecting the change in the inductive properties. 10

18. Method according to one of Claims 14 to 17, in which activation changes capacitive properties of the operating unit (1), and where detection involves detecting the change in the capacitive properties.