GB2361292A - Control apparatus for selecting and varying at least two parameters - Google Patents

Abstract

Control apparatus is described which can be used to vary two parameters such as the base and treble output levels of a sound system. The control apparatus 1 comprises a rotatable knob 4 having two separate zones 2, 3 of differing electrical conductivity. The location of the users fingers on the knob determines which of the parameters will be varied when the knob is rotated.

Description

2361292 1 CONTROL APPARATUS This application relates to control apparatus,

and more particularly to apparatus where at least two parameters may be varied by the operation of a single control device.

In order to increase the number of parameters controlled by the control devices (such as, for example, knobs, buttons and switches) on a control panel, it is generally necessary to increase the number of control devices. This requires either a greater density of control devices, or a larger control panel. This may not be possible if, for example, the control devices are already closely spaced and the available space is limited.

As an alternative, multi-function control devices have been proposed, whereby each control device may vary more than one parameter. The user may toggle the function of a single control device, such as a knob, by selecting buttons, switches, items on a computer screen, or by using some other independent ergonomic activity.

Dual concentric knobs have also been proposed which comprise two concentric, independently rotatable parts. Each rotatable part is connected to one of two concentric shafts. Each shaft is in turn connected to a variable controller (for example, a potentiometer). The arrangement could therefore initially include for example, two stacked potentiometers, or two very expensive and rare dual concentric encoders. Such arrangements may be complex and 2 expensive.

The present invention seeks to mitigate these disadvantages.

According to the invention, there is provided control apparatus for varying at least two parameters, comprising a control part, wherein the location of contact by the user on the control part determines which of the at least two parameters is varied.

Thus, the apparatus can simulate a dual concentric control device, such as a knob, but with a simpler design.

The control part may conveniently comprise a rotatable knob. Thus, where the user grasps the knob determines which parameter is adjusted.

The control part may conveniently comprise two surface zones of differing electrical conductivity, with one zone advantageously being metallic. This provides a simple and effective means for determining which zones are in contact with the user's hand.

The control part may conveniently be mounted on a control panel, and the control panel may include a capacitance touch circuit in electrical contact with one of the zones.

The control panel may further include software for selecting the parameter to be varied in response to the output from the capacitance touch circuit.

3 Thus, timple means for toggling the function of the control means are provided.

The location of contact by the user on the control part may be determined using optical means, with the control part having zones responsive to touch using optical means.

The apparatus may be suitable for varying the base and treble output levels of a sound system. Thus the apparatus may include first and second zones such that the base r-nay be varied when the user contacts the first zone, and the treble may be varied when the user contacts the second zone.

For a better understanding of the present invention, specific embodiments will now be described, by way of example, in which:- Fig. 1 shows a side view of a first embodiment according to the invention; Fig. 2 shows a schematic of the first embodiment according to the invention; Fig. 3 shows a touch circuit for use in the first embodiment according to the invention; Fig. 4 shows an alternative touch circuit for use in the first embodiment according to the invention; 4 Fig. 5 shows a schematic of a second embodiment according to the invention; Fig. 6 shows the second embodiment according to the invention; Fig.7 shows part of the second embodiment according to the invention; Fig. 8 shows a sectional view of shafts for use in the embodiments according to the invention; Fig. 9 shows a schematic of another embodiment according to the invention; Fig. 10 shows a schematic of another embodiment according to the invention; and Fig. 11 shows a side view of further embodiments according to the invention; As shown in Fig. 1, control apparatus 1 for varying at least two parameters, comprises at least two separate zones 2, 3 on control part 4, the arrangement being such that the zone or zones contacted by the user during operation of the apparatus determines which of the parameters is varied. The control part is movable and operable manually by a user, and comprises a rotatable knob 4 in the embodiment shown.

Rotation of the knob 4 while the user's fingers ccMtact the first zone 12 executes control over the parameter mapped to this zone. Rotation of the knob 4 while the user's fingers contacts the second zone 3 will execute control over the parameter mapped to that particular zone.

Thus, the location of the contact by the user determines which parameter is varied when the knob is rotated.

In the first embodiment, the first and second zones 2, 3 comprise surfaces of differing electrical conductivity. Specifically, the first zone 2 is formed of a metallic layer, whiles the second zone 3 is formed of a layer having a much lower electrical conductivity, such as an electrical insulator.

Fig. 2 shows the knob 4 mounted on a control panel 5 via shaft 6. The shaft 6 is connected to an encoder 7, whose output is fed into processor 8. The output of the encoder 7 varies corresponding to the rotation of the knob 4, and data is received continuously from the encoder 7 by the processor 8. The encoder may comprise, for example, a potentiometer (not shown).

The panel 5 also includes touch sensor 9 for determining which of the zones 2, 3 is contacted by the user. The output from touch sensor 9 is fed into processor 8.

The processor 8 receives inputs from both the encoder 7 and touch 6 sensor 9. The processor uses the output from touch sensor 9 to determine which Parameter should be varied, and the output from the encoder 7 to determine the amount by which the parameter should be varied.

In the embodiment zone 3 is an insulator, and is electrically insulated from shaft 6. Metallic zone 2 is in direct electrical contact with shaft 6. Electrical connection is provided between metallic zone 2 and the touch sensor 9 via shaft 6, metallic spring 10 pressing onto the shaft, and wiring 19. In use, the electrical capacitance differential caused the user touching zone 2 is transferred to touch sensor 9. In contrast, when the user touches zone 3, no capacitance differential is transferred to the touch sensor 9. The touch sensor is therefore able to detect which zone has been contacted by the user.

Touch sensor 9 includes capacitance touch circuit 11 shown in Fig. 3. The output OUT from the circuit indicates whether a user has touched zone 2. The touch circuit operates using a feed frequency 20 fed into clock input CLK, which is compared against the signal received from zone 2 by logic gate 12 (such as a microprocessor). When a user touches zone 2 the human touch transfers its capacitance via the circuit to logic gate 12, which in turn outputs a change (it kills the output frequency) and thereby indicates "-'a touch". Adjusting the frequency of the input signal CLK will adjust the sensitivity of the circuit.

Touch sensor 9 could include any suitable capacitance touch circuit 7 to distinguish between the user touching the different zones of the knob 4. An alternative capacitance touch circuit 13 is illustrated in Fig. 4.

To the operator, each touch sensitive zone on the knob 4 seems to behave as a dedicated controller. For example, in a sound system turning the knob 4 whilst touching the first zone 2 will control one parameter, such as the treble output level of the sound system. Touching only the second zone 3 of the knob whilst rotating the knob will control another parameter, such as the base output level of the sound system.

The apparatus could be used to vary any suitable parameters as desired. For example, the apparatus could alternatively vary the volume and balance (left to right) of the sound system.

The first embodiment simulates the operation of a dual concentric knob, with the advantage of having only a single moving part instead of several. Only one shaft and only one encoder (potentiometer) is required. This arrangement is advantageous in terms of both simplicity and cost.

The location of the user's fingers on the knob 4 activates the different functions mapped to the different zones. For example, the knob may be connected to a potentiometer, encoder or switch. To the user, the knob with its zones appears as mentioned hereinbefore to be a dedicated controller for a specific function, without the need for operating any further buttons or switches to control the 8 parameter to be varied.

Fig. 5 shows a schematic of a second embodiment, comprising a knob 4' having four different zones 21, 22, 23 and 24. Any one of four different parameters may be varied by the user contacting one of the four zones while rotating the knob 4'. The apparatus advantageously includes only one movable part and one encoder 7, instead of requiring a large number of encoders as in the prior art apparatus.

In the second embodiment, each of the four zones includes an inbuilt unique capacitance which is calculated and sensed by the touch sensor 9 and distinguishes it from the other zones. The inbuilt unique capacitance of each zone is added to human touch such that each zone will register a distinguishing value which enables the touch sensor to determine which zone has been contacted by the user. One of the zones may be an insulator as described earlier. In this case, rotation of the knob 4' while touching the insulator will still vary a parameter even though no contact by the user is positively detected.

Fig. 6 shows the four zones of the second embodiment. Four conductive paths T1, T2, T3 and T4 run the length of the shaft 6, electrically insulated from each other, and provide electrical connection between the zones 2 and the touch sensor 9. At the bottom of the shaft is the disc 15 shown in Fig. 7, with four circular conductive tracks 16 electrically insulated from each other. Each of the conductive paths T1, T2, T3 and T4 contacts one of the four 9 circular tracks 16 so that electrical contact between the zones and the touch sensor may be maintained while the knob 4' is rotating. The touch sensor 9 for the second embodiment may comprise the touch circuit 11 repeated four times, each circuit being electrically isolated from each other.

Fig. 8 shows sectional views of shafts for use in the embodiments according to the invention, with respectively four and three conductive tracks T1, T2, etc. Alternatively, these could be sleeves for fitting over a shaft.

Fig. 9 shows a schematic of a third alternative embodiment which has a plurality of zones 2N, 2N+l, 2N+2......

Fig. 10 shows a schematic of a fourth alternative embodiment which has a plurality of zones 2N, 2N+l, 2N+2 Touch sensor 9 receives signals from the zones 2N and also receives signals from the encoder 7. The data is then fed by the touch sensor to the processor 8.

The number of zones can be varied as desired. Zones may be provided in any arrangement on the knob. It will be understood that only one encoder is required per knob (which can be any suitable optical/digital variable controller). A single knob can thereby adjust and control any number of different parameters.

In an alternative arrangement, the touch sensor may be a transponder type, whereby a sub-miniature transponder is provided within the knob itself. Touching it's contact zone will alter the resonance of the transponder, thus distinguishing and sending unique signals down the shaft to be received by a touch multiplexer.

Further embodiments according to the invention are illustrated in Fig. 10. This shows some of the different possible arrangements of the zones. It is understood that the zones may be of any suitable shape or size, as desired.

The control means, which in the specific embodiment is a knob, can have a plurality of differently touch sensitive surfaces. This sensitivity may be provided either by electrically conductive surfaces and capacitance touch circuits as described, by optical means, or by any other suitable sensor technology. There may be multiple points or levels of touch differentiation provided on the knobs, for varying one or more parameters.

The manually operable control means of the specific embodiment is provided by a rotatable knob, but it is understood that any suitable control means could be provided, for example, a push-in knob or button, or other type of switch.

11

Claims (9)

CLAIMS:

1. Control apparatus for varying at least two parameters, comprising a control part, wherein the location of contact by the user on the control part determines which of the at least two parameters is varied.

2. Control apparatus according to claim 1, wherein the control part comprises a rotatable knob.

3. Control apparatus according to claim 1 or 2, wherein the control part comprises two surface zones of differing electrical conductivity.

4. Control apparatus according claim 3, wherein one of the two surface zones is metallic.

5. Control apparatus according to claim 1 or 2. wherein the location of contact by the user on the control part is determined using optical means.

6. A control panel, comprising control apparatus according claim 3 or 4, the control panel further comprising a capacitance touch circuit in electrical contact with one of the zones.

7. A control panel according to claim 6, the control panel further comprising software for selecting the parameter to be 12 varied in response to the output from the capacitance touch circuit.

8. Apparatus for varying the base and treble output levels of a sound system, comprising control apparatus or a control panel according to any preceding claim.

9. Control apparatus for varying at least two parameters substantially as described herein with reference to the accompanying drawings.