The present invention relates to a manually operable sensor for providing signals to an electronic device.
A manually operable position sensor is disclosed in U.S. Pat. No. 6,452,479, assigned to the present applicant. It is known for sensors of this type to communicate with electronic devices. In order to provide electrical communication between a sensor assembly and the electronic device, it is necessary to define tracks for electrical conduction. In known assemblies, these tracks are provided using electrically conductive tape surrounded by an insulating material. The tape itself is relatively expensive and, furthermore, costs are involved in terms of creating the assembly itself.
According to an aspect of the present invention, there is provided a manually operable sensor for providing control signals to an electronic device, comprising: fabric having a length substantially longer than its width with insulating yarns and electrically conductive yarns included therein, such that said conductive yarns define first, second and third conductive tracks running the length of said fabric; said conductive tracks are configured to interface with an electronic device; and, at a second end an active region of the fabric forms part of a sensor assembly that is receptive to a manually applied pressure; wherein said sensor assembly comprises: a first conductive region and a separate second conductive region; said first conductive track is connected to said first conductive region, to apply a first electric potential, said second conductive track is connected to said second conductive region, to apply a second electric potential, a conductive path is formed between said first conductive track and said third conductive track of said active region when manual pressure is applied to said first conductive region, and a conductive path is formed between said second conductive track and said third conductive track of said active region when manual pressure is applied to said second conductive region.
It should therefore be appreciated that the invention provides for relatively inexpensive transmission tracks. Furthermore, these tracks are included within the sensor itself thereby further facilitating construction. A sensor of this type is particularly suitable for switch control, as used for the control of electronic devices such as mobile phones and audio players.
The particular nature of the fabric may vary but in a preferred embodiment the fabric is produced by a weaving process in which the weft yarns are woven between warp yarns and the conducting yarns are included as part of the warp yarns.
According to a second aspect of the present invention, there is provided a method of constructing a manually operable sensor for providing control signals to an electronic device, comprising the steps of: weaving a fabric with electrically conducting warp yarns that define three conductive tracks that run the length of the fabric; connecting said conductive tracks at a first end to a connector for interfacing with an electronic device; and, at a second end forming a sensor assembly that is receptive to manually applied pressure over an active region of the fabric, the sensor assembly comprising a first conductive region and a separate second conductive region; connecting a first conductive track to said first conductive region, and connecting a second conductive track to said second conductive region.
The invention will now be described by way of example only, with reference to the accompanying drawings, of which:
An embodiment of a manually operable sensor is illustrated in
In a preferred sensor, the fabric is produced by a weaving process in which weft yarns are woven between warp yarns and the conducting yarns, that form tracks 104, 105 and 106, are included as part of the warp yarns. Thus, as the fabric is woven, it is produced in the direction indicated by arrow 102.
In a preferred embodiment, the conductive yarns are silver coated nylon and each conductive track 104 to 106 may have between five (5) and ten (10) conducting yarns, with seven (7) conducting yarns being present in a preferred embodiment. Multifilament conductive yarns or threads may be used in the construction of the sensor.
In a preferred embodiment, the spacing between the conductive tracks (the insulating portions) is such that it is greater than the width of the conducting tracks themselves. Preferably, the spacing is made consistent with readily available circuit connectors, such as circuit connector 107 that, typically, facilitates a spacing of two point five millimetres (2.5 mm). Thus, if alternate connections are selected, a spacing of five millimetres (5 mm) is achievable, as is preferred in the present embodiment.
In a preferred embodiment, active region 108 forms part of a sensor assembly providing discrete switches, in which the application of manual pressure is identified through detection of an electrical connection between two conductive tracks. The sensor assembly comprises a first conductive region 109 and a separate second conductive region 110. A first conductive track 104 may apply plus volts to a position 111 of the first conductive region 109. Similarly, second conductive track 105 may apply plus volts to a position 112 of the second conductive region 110. At a position where pressure is applied to the first conductive region, causing a mechanical interaction, a voltage is applied to conductive track 105, and at a position where pressure is applied to the second conductive region a voltage is also applied to conductive track 105 in response. Thus, the first and second conductive regions, in combination with the active region of the fabric, provide two discrete switches. The position of conductive regions may be emphasised by the provision of masking.
A function may be associated with each of the first and second conductive regions, such that by determining which of the first and second discrete switches has been manipulated, it is possible to determine the actual function that has been selected.
An example of an application for the sensor is shown in
Alternatively, the data input device may include commands for controlling a mobile device such as a radio device, a mobile telephone or an audio player, such as an MP3 player.
An example of a sensor construction is illustrated in
In
Without pressure being applied, separation layer 302 prevents the conductive regions 301, 302 from being placed into electrical contact with the central third conductive track 105. However, when pressure is applied, separation layer 304 is compressed and as such electrical connection takes place at the position of the mechanical interaction, that is, where the pressure is applied.
To facilitate the detection of a mechanical interaction with a conductive region, masking means are provided. In the preferred embodiment, the masking means includes a first mask 309 and a second mask 310. The first mask 309 is located above the separation layer 304 and the second mask 310 is located below the separation layer. First mask 309 defines a first window 311 vertically aligned within first conductive region 301 and a second window 312 vertically aligned within second conductive region 302. Similarly, second mask 310 defines a third window 313 vertically aligned with first window 311 and a fourth window 314 vertically aligned with second window 312.
An enhanced embodiment is illustrated in
As illustrated in
As illustrated in
A further sensor arrangement is illustrated in
Within the sensor assembly, conductive tracks 702, 703, 705 and 706 are respectively electrically connected to conductive regions 707, 708, 709 and 710 by conductive stitching, with central conductive track 704 remaining as the common track to which electrical connection is made during a mechanical interaction. The sensor hence provides four (4) discrete digital switches, being arranged such that a conductive path is established between conductive tracks 702 and 704, 703 and 704, 705 and 704 or 706 and 704 depending upon which conductive region manual pressure is applied. Thus, it can be understood that to provide a number X of switches, the number X+1 conductive tracks are required.
In summary, it will be appreciated that the switch sensor may be constructed by firstly weaving a fabric with electrically conducting warp yarns that define three conductive tracks that run the length of the fabric. An electrical connector is connected to the conductive tracks at a first end to facilitate the interfacing of the sensor with an electronic device. Then, at a second end, a sensor assembly is formed that is receptive to manually applied pressure over an active region of the fabric.
Number | Date | Country | Kind |
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0622204.6 | Nov 2006 | GB | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB07/04255 | 11/7/2007 | WO | 00 | 1/26/2010 |