Examples of the present invention will now be described with reference to the accompanying drawings, in which:
a to 16c show apparatus of a ninth embodiment of the present invention, where
The button is part of a larger array of buttons, such as an array of keys on a keyboard. The button comprises a button member 1, and a shutter 3 connected to the button member 1.
The button member 1 and the shutter 3 are moveably secured by a housing 7, whereby a user, upon pushing the button member 1, will cause the button member 1 and the shutter 3 to move downward from a rest position to a lower position, as shown in
The input button includes a biassing element, such as a spring, surrounding the actuation member 2, to resiliently urge the button member 1 and the shutter 3 back to the upper rest position.
The button member 1 may, alternatively, not be directly connected to the shutter 3, but rather the shutter 3 may form a separate component onto which the button member 1 abuts. For example, the shutter 3 may be formed on a rubber key mat positioned beneath the button member 1. In an unpressed state, the spring action of the rubber key mat urges the shutter 3, and hence the button member 1, into an upper rest position. When a user presses the button member 1, it acts as a plunger on the shutter 3 and forces it down into a lower position.
In the example shown in
The proximate ends of the pneumatic channels 5 open at apertures 6 onto the underside of the housing 7. When the shutter 3 is in its upper position, it is seated against the underside of the housing 7 so as to act as a seal and blocks apertures 6.
Preferably, the shutter is formed of an elastic material such as foam rubber so as to form an effective seal and is biassed into the upper position by a spring surrounding the actuation member 2, or another resilient configuration such as a rubber key mat.
At a remote end of the pneumatic channels 5, a pump is provided which acts to reduce the air pressure within the channel, thereby generating a partial vacuum within the pneumatic channels. When the button is in a normal unpressed state, this partial vacuum is maintained by the pump and air is prevented from entering the pneumatic channels 5 by the shutter 3. Preferably, the pressure within the pneumatic channels in the unpressed state is approximately 5 PSI below atmospheric pressure. Additionally, the remote end of the each channel is also provided with a pressure sensor for detecting a change in pressure within the channel and responsively outputting an electrical signal.
Upon a user pressing a button, the shutter 3 is moved towards its lower position, thereby opening the apertures 6 and allowing air to flow through the pneumatic channels 5.
Subsequently, there is an increase of pressure within the pneumatic channels as the vacuum is breached. This increase in pressure is then detected by the pressure sensors connected to the remote ends of each channel, which in turn outputs an electrical signal.
In a preferred embodiment the pressure sensor has a sensor adjustment means which allows the sensitivity of the sensor to be adjusted. In this way, the sensitivity of the sensor can be adjusted according to the level of ambient atmospheric pressure and the required reduced pressure level within the pneumatic channels, to thereby optimise the detection of a change in pressure. For example, at altitude, where atmospheric pressure is lower, a user or an automated system may increase the sensitivity of the sensor to account for the reduced pressure gradient between atmosphere and the partial vacuum.
Advantageously, with this embodiment, since the pneumatic channels are normally under a partial vacuum, any bending and compression of the channels, is less liable to result in false positive detection of a button member actuation, compared to pressurised systems.
Similar to the first embodiment, a user pushing the button member 21 will cause the button member 21 and the actuating member 22 to move downward from a rest position, as shown in
Beneath each button member 21, disposed below the actuating member 22, one or more media paths are provided. For simplicity only one media path is shown in
As shown, the actuating member 22 is configured to compress the channel 5 when the button member 21 is urged into a lower position. In their normal state, the channels 25 can either be maintained at a positive pressure, i.e. above atmospheric pressure, or allowed to remain at atmospheric pressure. If the channels 25 are to be maintained at a positive pressure, then a pump (not shown) is provided which acts to increase the pressure within the channel 25. If the channels are allowed to remain at atmospheric pressure, then a pump is not required.
When the button member 21 is in a normal unpressed state, the pressure in the channel 25 remains constant. The remote end of the each channel is provided with a pressure sensor for detecting a change in pressure within the channel and responsively outputting an electrical signal.
Upon a user pressing a button member, the actuating member 22 is moved towards its lower position, thereby compressing the channel 25. Subsequently, there is an increase of pressure within the channel as the volume within the pneumatic channel is effectively reduced. This increase in pressure is then detected by the pressure sensors connected to the remote ends of each channel, which in turn outputs an electrical signal indicating that the pressure has increased.
The channels may be filled with any suitable fluid medium, for example, air or liquid.
The pressure sensor is able to detect the intensity of the compression imparted by the actuating member, i.e. the greater the force of compression, the greater the signal produced.
In order to ensure a change in pressure upon compression of the channel and to enable positive pressurisation of the channel prior to compression by an actuating member, the end of the channel which is not connected to a pressure sensor is preferably sealed. In this connection, as detailed below with reference to further embodiments of the present invention, one end of the channel may be formed into a sealed bulbous element for interaction with the actuating member 22.
In the construction shown in
Once assembled, the layers are arranged on top of one another. A button member 31, preferably formed of a plastics material, can be aligned above the bellows. An actuation member 32, in the form of three plungers, is provided on the button member 31. The central plunger is configured to compress the bellow 36 on the upper layer, when the actuation member is in its lower position. The two peripheral plungers are configured to extend through apertures 39 provided in the upper layer to the lower layer, where they can compress the bellow 36 on the lower layer, when the actuation member is in its lower position.
The upper flexible layer 48a contains a channel 45a with associated bellow sections 46a which operate in the same way as discussed above. Also provided on the upper flexible layer 48a is a bellow section 46b which is associated with a channel 45b formed on the lower flexible layer 48b through aperture 451. A button member 41 is aligned with the layers, and hence the bellows 46a and 46b, by an alignment peg 491 which fits into apertures 49. Once aligned, the actuation member 42 has two protrusions which are positioned above the bellows, and the button being pressed causes them to move downwardly to compress the bellow sections.
In the above embodiments it is preferable that the channels have internal bore sizes in the region of 1 mm. If the bore sizes are too small, fluid flow is too restricted and the response speed is slower. If the bores are too large, the volume of fluid is increased and the strength of the signal is reduced. There are of course also a number of additional features which can be included in the above designs. For example, in embodiments which rely on increases in pressure, such as the second, third and fourth embodiments described above, a totally sealed system can cause false activation of the pressure sensors if, for example, direct sunlight heats up the fluid inside the channels. Accordingly, it is preferable that a small vent hole is provided in the channels which allows for slow changes in pressure to be equalised. The vent hole should be pin-hole size to avoid pressure being bled off too quickly from a key press.
The arrangement of the above described embodiments within the context of a larger array of buttons will now be described.
The main pneumatic channels 55 are connected to remote sensing apparatus and micro controller, which can convert and process the unique signature into an electronic signal for use in operating one or more functions of electronic device. In this embodiment, a pump is used to create a partial vacuum within the main pneumatic channels 55. Preferably, air flow restricting means are incorporated into the connections between the main pneumatic channels 55 and the pump. The airflow restricting means help prevent pressure increases in activated channels interfering with inactive channels. Conveniently, the main pneumatic channels 55 can be arranged to form essentially a single cable of multi-core tubing. In this way, the majority of the length of the main pneumatic channels 55 between the matrix and the pump appears as a single cable or tube, with each of the main pneumatic channels 55 being a separate core within the multi-core tube.
Accordingly, the cabling or tubing is kept compact and tidy.
Each button has up to four apertures 56 associated with it which are connected to a unique combination of pneumatic paths 555 and hence main pneumatic channels 55. More or less apertures 56 can be used with different button configurations and/or different button members. When a button is pressed, a pressure increase intone or more of the pneumatic paths is simultaneously detected by the pressure sensors at the remote ends of the main pneumatic channels 55. The combination of the pneumatic paths 555, and hence the main pneumatic channels 55, in which a pressure increase is detected, is then used by the micro controller to identify which of the buttons has been pressed, and in response output the appropriate electrical signal to an electronic device.
Each of the buttons has up to four apertures 66 which open onto the underside of the bottom pneumatic layer. The apertures 66 project up from the under surface and connect into one or more of the pneumatic paths 655 in one or more of the layers 61. For example, an aperture may connect into a pneumatic path in the bottom layer or project up to connect to a pneumatic path in the top layer. The pneumatic layers' 61 three dimensional structure allows the pneumatic paths 655 to be isolated from one another to form a dense network of paths. A vestibular layer 69 is provided beneath the bottom pneumatic layer and forms a cavity into which the apertures 66 open to the outside atmosphere. In this embodiment, a key mat 63, having a number of shutters 64 formed thereon, is provided below the vestibular layer 69. When fitted together, the shutters 64 fit inside the cavity formed by the vestibular layer 69 and align with the corresponding button apertures 62 in the pneumatic layers 61 above. In this way, when a button member 61 is fitted, it passes through the button apertures 62 and abuts at or adjacent one of the shutters 64.
In a normal un-pressed state, the shutters 64 sit in a upper rest position and seal the apertures 66. When a button member is operated by a user, the button member pushes one of the shutters 64 downwardly, opening the apertures 66 for that button to the cavity in the vestibular layer 69, thereby allowing atmospheric pressure to enter the pneumatic paths 655. As each button is connected to a unique combination of pneumatic paths 655, operation of a particular button therefore results in a unique signature created by paths 655 in the main pneumatic channels which service them. This allows the number of main pneumatic channels required to service the array of buttons to be reduced.
Several channels, A-M, i-xvi, are arranged in a matrix so that each button member 71 is positioned above one or more, and typically two, channels. For clarity, each channel is depicted as a single line. In this respect, the actuating member 72 of each button member 71 is arranged to compress the one or more channels relating to that button member when the associated button member is depressed, so that depression of each button member will cause a unique signature of pressure change in the channels detected by pressure sensors connected to the end of each channel.
Accordingly, in the example shown in
The configuration of the matrix, as shown above in reference to
In the above examples, the distal ends of the channels are connected to remote sensing apparatus and micro controller, which can convert and process the unique signature into an electronic signal for use in operating one or more functions of an electronic device. Conveniently, the channels can be arranged to form essentially a single cable of multi-core tubing. In this way, the majority of the length of the main channels between the matrix and the sensors appears as a single cable or tube, with each of the channels being a separate core within the multi-core tube. Accordingly, the cabling or tubing is kept compact and tidy.
When a button member is pressed, a pressure increase in one or more of the channels is transferred to the distal ends of the channels where it is applied to the conductive domes 102. This causes the conductive domes to connect a circuit 103 on an underlying substrate. This connection indicates that there has been a pressure increase in that channel. The combination of the channels in which a pressure increase is detected is then used by the micro controller to identify which of the button members has been pressed, and in response output the appropriate electrical signal to an electronic device. As will be appreciated, a similar detector could be used to detect an increase in pressure in the case of the buttons shown in
As the bulbous portions 86a, 86b are alternatively compressed, the pressure inside the pneumatic channels 85a, 85b is likewise alternatively increased. The increase in pressure is detected by the pressure sensor 88 and then converted to an electrical signal for remote output to a computer (not shown). Each bulbous portion 86a, 86b, and hence each channel can be configured to produce an electrical output corresponding to a direction of movement. For example, in the embodiment shown in
Further button members may be provided within the mouse for effecting selection of icons highlighted by a cursor on a computer screen. These further button members may be provided in accordance with one of the second to fourth embodiments of the present invention, i.e. with an actuating member for compressing a channel when urged into a lower position, or for compressing a bulbous portion of a channel.
In the embodiment described with reference to
a to 16c show apparatus of a ninth embodiment of the present invention, similar to that shown in
a and 16b respectively show a plan view and a perspective view of the mouse. In this example, the button member is in the form of a mouse shaped slider 91 which sits on housing 94. The mouse shaped slider 91 is moveable relative to the housing 94 for effecting the various directional movements of the mouse.
c shows a cross-sectional plan view of the mouse. As shown, in this example, four bellows 96 are provided inside the housing 94. An actuation member 92 is provided on the underside of the mouse shaped slider 91 so that when the mouse shaped slider 91 is moved in a particular direction, one or more of the bellows 96 is compressed by the actuation member 92, resulting in an increase in pressure in the associated channels 95. As with previous embodiments, this increase in pressure can then be used, via pressure sensor and microprocessor to effect movement of a cursor in a range of directions.
As shown, the mouse also includes a number of buttons on the mouse shaped slider 91 allowing for the selection of icons highlighted by a cursor on a computer screen. These further buttons involve an actuating member for compressing a channel when urged into a lower position.
It will be appreciated that a number of variations can be made to the apparatus. For example, whilst, the above description relates primarily to buttons for keyboard like structures, the invention encompasses other forms of input devices, such as a computer mouse. Furthermore, the fluid used in the channels may be any suitable liquid, such as water or an oil. Alternatively it may be a gas such as air. A reservoir may be provided for topping up the channels, preferably with a non-return valve.
Number | Date | Country | Kind |
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0414437.4 | Jun 2004 | GB | national |
0504329.4 | Mar 2005 | GB | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB05/02311 | 6/10/2005 | WO | 00 | 9/10/2007 |