The following relates generally to switches, and more particularly to two-stage electrical switches.
In electronic devices, such as digital cameras devices, there may be different functions corresponding to various keys with which the user interacts. For example, in a camera device, one key may allow the user to control the on/off functionality, while an ancillary key controls the camera shutter. As the number of functions of electronic devices increases, it is expected that the number of user control keys would also increase, which can lead to over crowding of keys and increased user interface complexity.
There are various switch devices that combine two separate switches into a single key. For example, a camera device may provide the focusing function and the camera shutter function in a single two-stage switch under control of a common push button. Such devices operate by receiving a first downward force on a switch device to activate the focusing function. After the camera device has focused, if the device receives a second downward force greater than the first downward force, the camera shutter function is then activated, thereby capturing an image.
The above devices often utilize a single push button with an actuator protruding from the key to depress a dual action dome switch to first activate the auto-focus, and then the camera shutter. For improved performance, the actuator should be aligned with the dome switch, which can be difficult to control without adding complexity to the device.
When implementing two-stage electrical switches, there may also be difficulty in discerning between the different stage activations through tactile feedback.
Embodiments will now be described by way of example only with reference to the appended drawings wherein:
a) is a profile view of the push key shown in
b) is a bottom plan view of the push key shown in
c) is a top plan view of the push key shown in
a) is a profile view of the push key shown in
b) is a bottom plan view of the push key shown in
c) is a top plan view of the push key shown in
a) is a profile view of the lower surface shown in
b) is a top plan view of the lower surface shown in
a) through 18(c) illustrate exemplary stages of operating the two-stage switch shown in
a) through 19(c) illustrate exemplary stages of operating the two-stage switch shown in
It will be appreciated that for simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the embodiments described herein. Also, the description is not to be considered as limiting the scope of the embodiments described herein.
In the field of electronic devices, push keys may be used to activate functions within the device. The operation of input devices, for example push keys, may depend on the type of electronic device and the applications of the device.
Examples of applicable electronic devices include pagers, cellular phones, cellular smart-phones, wireless organizers, personal digital assistants, computers, laptops, handheld wireless communication devices, wirelessly enabled notebook computers, camera devices and the like. Such devices will hereinafter be commonly referred to as “mobile devices” for the sake of clarity. It will however be appreciated that the principles described herein are also suitable to other devices, e.g. “non-mobile” devices.
In an embodiment, the mobile device is a two-way communication device with advanced data communication capabilities including the capability to communicate with other mobile devices or computer systems through a network of transceiver stations. The mobile device may also have the capability to allow voice communication. Depending on the functionality provided by the mobile device, it may be referred to as a data messaging device, a two-way pager, a cellular telephone with data messaging capabilities, a wireless Internet appliance, or a data communication device (with or without telephony capabilities).
The mobile device 100a shown in
The display 12 may include a selection cursor 18 that depicts generally where the next input or selection will be received. The selection cursor 18 may comprise a box, alteration of an icon or any combination of features that enable the user to identify the currently chosen icon or item. The mobile device 100a in
The mobile device 100b shown in
It will be appreciated that for the mobile device 100, a wide range of one or more positioning or cursor/view positioning mechanisms such as a touch pad, a positioning wheel, a joystick button, a mouse, a touchscreen, a set of arrow keys, a tablet, an accelerometer (for sensing orientation and/or movements of the mobile device 100 etc.), or other whether presently known or unknown may be employed. Similarly, any variation of keyboard 20, 22 may be used. It will also be appreciated that the mobile devices 100 shown in
To aid the reader in understanding the structure of the mobile device 100, reference will now be made to
Referring first to
The main processor 102 also interacts with additional subsystems such as a Random Access Memory (RAM) 106, a flash memory 108, a display 110, an auxiliary input/output (I/O) subsystem 112, a data port 114, a keyboard 116, a speaker 118, a microphone 120, a GPS receiver 121, short-range communications 122, a camera 123 and other device subsystems 124.
Some of the subsystems of the mobile device 100 perform communication-related functions, whereas other subsystems may provide “resident” or on-device functions. By way of example, the display 110 and the keyboard 116 may be used for both communication-related functions, such as entering a text message for transmission over the network 200, and device-resident functions such as a calculator or task list.
The mobile device 100 can send and receive communication signals over the wireless network 200 after required network registration or activation procedures have been completed. Network access is associated with a subscriber or user of the mobile device 100. To identify a subscriber, the mobile device 100 may use a subscriber module component or “smart card” 126, such as a Subscriber Identity Module (SIM), a Removable User Identity Module (RUIM) and a Universal Subscriber Identity Module (USIM). In the example shown, a SIM/RUIM/USIM 126 is to be inserted into a SIM/RUIM/USIM interface 128 in order to communicate with a network. Without the component 126, the mobile device 100 is not fully operational for communication with the wireless network 200. Once the SIM/RUIM/USIM 126 is inserted into the SIM/RUIM/USIM interface 128, it is coupled to the main processor 102.
The mobile device 100 is a battery-powered device and includes a battery interface 132 for receiving one or more rechargeable batteries 130. In at least some embodiments, the battery 130 can be a smart battery with an embedded microprocessor. The battery interface 132 is coupled to a regulator (not shown), which assists the battery 130 in providing power V+ to the mobile device 100. Although current technology makes use of a battery, future technologies such as micro fuel cells may provide the power to the mobile device 100.
The mobile device 100 also includes an operating system 134 and software components 136 to 146 which are described in more detail below. The operating system 134 and the software components 136 to 146 that are executed by the main processor 102 are typically stored in a persistent store such as the flash memory 108, which may alternatively be a read-only memory (ROM) or similar storage element (not shown). Those skilled in the art will appreciate that portions of the operating system 134 and the software components 136 to 146, such as specific device applications, or parts thereof, may be temporarily loaded into a volatile store such as the RAM 106. Other software components can also be included, as is well known to those skilled in the art.
The subset of software applications 136 that control basic device operations, including data and voice communication applications, may be installed on the mobile device 100 during its manufacture. Software applications may include a message application 138, a device state module 140, a Personal Information Manager (PIM) 142, a connect module 144 and an IT policy module 146. A message application 138 can be any suitable software program that allows a user of the mobile device 100 to send and receive electronic messages, wherein messages are typically stored in the flash memory 108 of the mobile device 100. A device state module 140 provides persistence, i.e. the device state module 140 ensures that important device data is stored in persistent memory, such as the flash memory 108, so that the data is not lost when the mobile device 100 is turned off or loses power. A PIM 142 includes functionality for organizing and managing data items of interest to the user, such as, but not limited to, e-mail, contacts, calendar events, and voice mails, and may interact with the wireless network 200. A connect module 144 implements the communication protocols that are required for the mobile device 100 to communicate with the wireless infrastructure and any host system, such as an enterprise system, that the mobile device 100 is authorized to interface with. An IT policy module 146 receives IT policy data that encodes the IT policy, and may be responsible for organizing and securing rules such as the “Set Maximum Password Attempts” IT policy.
Other types of software applications or components 139 can also be installed on the mobile device 100. These software applications 139 can be pre-installed applications (i.e. other than message application 138) or third party applications, which are added after the manufacture of the mobile device 100. Examples of third party applications include games, calculators, utilities, etc.
The additional applications 139 can be loaded onto the mobile device 100 through at least one of the wireless network 200, the auxiliary I/O subsystem 112, the data port 114, the short-range communications subsystem 122, or any other suitable device subsystem 124.
The data port 114 can be any suitable port that enables data communication between the mobile device 100 and another computing device. The data port 114 can be a serial or a parallel port. In some instances, the data port 114 can be a USB port that includes data lines for data transfer and a supply line that can provide a charging current to charge the battery 130 of the mobile device 100.
For voice communications, received signals are output to the speaker 118, and signals for transmission are generated by the microphone 120. Although voice or audio signal output is accomplished primarily through the speaker 118, the display 110 can also be used to provide additional information such as the identity of a calling party, duration of a voice call, or other voice call related information.
Turning now to
The status region 44 in this embodiment comprises a date/time display 48. The theme background 46, in addition to a graphical background and the series of icons 42, also comprises a status bar 50. The status bar 50 provides information to the user based on the location of the selection cursor 18, e.g. by displaying a name for the icon 53 that is currently highlighted.
An application, such as message application 138 may be initiated (opened or viewed) from display 12 by highlighting a corresponding icon 53 using the positioning device 14 and providing a suitable user input to the mobile device 100. For example, message application 138 may be initiated by moving the positioning device 14 such that the icon 53 is highlighted by the selection box 18 as shown in
The camera application 60 may be activated by pressing a camera button 17, such as the camera button 17a shown in
The two-stage camera button 17 may also be used on various other devices, such as a dedicated camera including, for example, the camera 100c shown in
It may be appreciated that a two-stage button 17 may be used in other devices for various applications that require a two-stage operation, and the principles described herein should not be limited to only activating camera focusing and shutter functions. Other devices and applications may include, for example, setting the time on a watch. In such an example, the first stage on the button may be used to advance the time, while the second stage on the button may be used to select and set a certain time. Other applications for the two-stage button 17 may also be used for video recording applications, flash-camera shutter combinations and scroll-through media.
Turning now to
The camera button 17 may be configured to include two adjacent, laterally spaced regions, namely a contact switch region and a dome switch region. The contact switch region in this example comprises the protrusion 302 of the push key 300, to which a resilient ring 308 and conductive contact pad 306 are attached. Facing opposite the contact pad 306, and also within the contact switch region, is a contact gap 310 that is attached to a lower surface 312. As will be discussed in further detail below, the contact gap 310 may comprise conductive terminals separated by a space such that when a conductive element, such as the contact pad 310, contacts both conductive terminals, then a circuit is completed. The dome switch region of the camera button 17 comprises the protruding broad surface 304 that is aligned with the dome switch 314. The dome switch 314 is positioned on the same lower surface 312 as the adjacent contact gap 310. In the embodiment shown in
It is appreciated that the contact gap 310 may not necessarily be supported by the lower surface 312. For example, in another embodiment not shown, the contact gap 310 is supported below the contact pad 306 by the resilient ring 308.
Although not shown, in other embodiments a hard-stop protrusion may be spaced below the key cap 422 in the vicinity of the contact switch region. The hard-stop protrusion is a rigid structure that is shaped or positioned to allow the key cap 422 to travel sufficiently downwards such that the contact pad 306 engages the contact gap 310 to close the contact switch. However, when the push key 300 or key cap 42 continues to receive further downward force after closing the contact switch, the hard-stop protrusion abuts against the bottom surface of the key cap 422 to prevent one side of the key cap from moving downwards any further. This in effect, creates a physical and tactile hard-stop in the contact switch region. From the user's perspective, for example, upon the key cap 422 engaging the hard-stop protrusion, the user's finger may begin to slide laterally and downwards along the key cap 422 towards the dome switch region. It can be appreciated that the hard-stop protrusion may extend from the external casing 322, the lower surface 312, an internal casing (not shown), or any other structure that can support the force acting on the hard-stop protrusion. The hard-stop protrusion may be used with various embodiments of the button 17.
The upper stage of the button 17 is shown in
The resilient ring 308 comprises several functions that may be noted. The resilient ring 308 may be relied upon to support the weight of the push key 300 in order to prevent the contact pad 306 from engaging the contact gap 310 in the absence of an external force being applied. The resilient ring 308, therefore, should be strong enough to support the weight of the push key 300. After an external force has been applied to the button 17 and, then removed, the resilient ring 308 may function as a resilient member to return the push key 300 to a neutral or rest position, as shown in
The resilient ring 308 may also function as a seal to prevent unwanted particles, such as dirt for example, from contaminating the gap between the contact pad 306 and the contact gap 310. It can be appreciated that the existence of particles between the contact pad 306 and contact gap 310 may prevent the two conductive surfaces from engaging, thereby preventing the electric switch from closing. As best shown in
It can be appreciated that the shape of the resilient ring 308 is not limited to any particular geometry. By way of example, the resilient ring may also take the shape of a triangle, square, or octagon or random shape. It can also be appreciated that the ring 308 may, in some embodiments, not be required to completely surround the perimeter of the contact pad 306. In other words, the ring 308 may be broken along certain segments, so long as the ring 308 resiliently separates the contact gap 306 and the contact pad 310 when the button 17 is in a rest position.
Various types of springs, including coil springs, may be used in the two-stage button 17. There may, however, be advantages to using a resilient ring 308 that comprise a reduction in noise level during use, a reduction in mechanical complexity, a decreased cost and a reduced profile height. A resilient ring 308 may create less noise during compression and decompression. Further, the mechanical simplicity of a resilient ring 308 may lead to longer usage over many cycles of compression and decompression. Moreover, the mechanical configuration of the resilient ring may decrease the manufacturing complexity and cost. A resilient ring 308 may also tend to require a lower profile, thereby decreasing the volume occupied by two-stage button 17. This may be desirable for various mobile devices where space may be limited.
As noted above, the resilient ring 308 may partially or completely surround the contact pad 306 depending on the application and environment in which the switch assembly is to be used. The contact pad 306 comprises an electrically conductive material such as, for example, copper or gold. A function of the contact pad 306 is to bridge the contact gap 310 and complete a circuit. It may be understood that the contact pad 310 may have various geometries, not limited to a circular shape as shown in
As also noted above, the push key 300a in
It can be appreciated that one or more heat staking structures 420 may be used to prevent the push key 300a from becoming dislodged from the external casing 322. Moreover, the push key 300a may use the heat staking structure 420 as a support to guide the collapsed push key 300a to return to its neutral position and form after the downward force acting on the push key 300a is removed. This method of securing the push key 300a may be suitable for configurations wherein the external casing 322, in a similar plane as the key cap 422, allows for a heat staking structure 420 to extend downwards through the push key 300a. Other methods of securing and supporting a push key 300 may also be used.
The upper stage of the button 17, according to
As also noted above, the push key 300b in
Referring now to
The combination of a locking ring 316 and locking post 320 reduces the mode of mechanical failure in which a push button or key may break-off a mobile device 100. Breakage of the push key may occur when a mobile device 100 receives a sudden force such as, for example, the impact force resulting from dropping the device onto a hard surface. In this example, the locking ring 316 and locking post 320 can resist the impact force and, as a result, may prevent the push key 300 from dislodging.
It can be appreciated that the contact gap 310 is not limited to a configuration comprising two conductive terminals and may instead, for example, comprise a single conductive terminal. For example, the contact pad 306 may comprise a single conductive terminal to engage another single conductive terminal located in the contact gap 310. Alternatively, in yet another example, the above contact pad 306 may comprise two conductive terminals that are to be bridged by the lower contact gap 310. Therefore, in general, as the contact pad 306 on the push key 300 engages the lower contact pad 310, two conductive terminals of any configuration may be connected.
The dome switch 314 in this example is adjacent to the contact gap 310. The dome switch 314 is a single-action mechanism that connects a set of contact terminals upon receiving a force. Referring to
It can be appreciated that a metal dome shell 330a may generally require larger forces to collapse the dome shell 330 over non-metallic dome shells 330b. A larger force may provide more distinct tactile feedback between activating the contact pad switch and the dome switch.
It may also be appreciated that various combinations of types of dome switches 300, methods to secure the push key 300, and options for using a key cap 422 are equally applicable to the two-stage button 17.
In the general configuration described above, the two-stage button 17, as shown in
Referring now to
In Stage 0, no force is applied to the key cap 422. The resilient ring 308 supports the weight of the push key 300, separating the contact pad 306 from the contact gap 310, which also can prevent the dome switch 314 from being collapsed. As noted above, the heat staking structure 420 or locking ring's 316 arms may also be used to provide support for the push key 300.
In Stage 1, the user then applies a first downward force that acts on the key cap 422. The key cap 422 may receive the force from a user that is exerting the pressing force using a finger 400 as shown in
Also, in Stage 1, while the finger 400 maintains contact with the key cap 422 and maintains the first force, the apex of the erect dome switch 314 may or may not be in contact with the push key's broad surface 304. In the case where the broad surface 304 is touching the dome switch 314, as shown in Stage 1 of
In Stage 2, an increased force is experienced, namely, a second force received by the key cap 422 in Stage 2 is greater than the first force received in Stage 1. When the key cap 422 receives the second force, the vertical position of the push key 300 within the contact pad switch region remains unchanged because the lower surface 312 is supporting the push key 300 via the contact gap 310 and contact pad 306. However, the vertical position of the push key 300 decreases in the dome switch region because of the second greater force. The rigid key cap 422 and attached push key 300 pivots downwards around the contact pad switch region. The pivot motion allows the push key 300 in the dome switch region to travel downward. The second force is transmitted through the push key's broad surface 304, which in turn acts on the dome switch 314 and thereby collapses the dome switch shell 330. In this situation 404, the metal dome shell 330a collapses to touch the corresponding terminal pad 332. The dome switch connection in Stage 2 may activate a second function, such as a camera shutter.
As noted, during Stage 2, the user may exert a second force that is greater than the first force by pressing down harder. In one embodiment, as the user's finger 400 bends, the area of the finger 400 in contact with the push key 300 may increase and, moreover, slide into the dome switch region. The sudden compression of the dome switch 314 and contact stop between the contact pad 334 and gap 332 can be felt by the user. In some cases, the user may feel a pivoting motion in the rigid key cap 422 as the dome switch 314 collapses. This reinforces through tactile feedback that Stage 2 of the switch activation process has occurred. In general, the method in which a user exerts a pressing force on to the two-stage button may vary.
After the user removes the finger 400 from the push key 300, then the absence of an applied downward force allows the dome switch 314 and resilient ring 308 to decompress and return to their neutral or rest position (i.e. Stage 0).
The configurations exemplified above, wherein a pair of switches are laterally positioned adjacent to one another, may afford several perceived advantages. The contact pad and dome switches used in the button 17 as described herein can reduce misalignment by using broad surfaces that are positioned close to the corresponding switching device. By having two broad surfaces 302, 304 on the push key 300 that are positioned adjacent to one another, the increased surface area of each switch may increase the likelihood of proper alignment. Furthermore, the vertical distance between the contact pad 306 and contact gap 310, as well as between the broad surface 304 and the dome switch 314, is relatively small and can thus further reduce the chance of misalignment. The vertical distance between the contact pad 306 and contact gap 310 in one embodiment may be in the order of, for example, 1 millimetre.
Another perceived advantage of the contact pad and dome switches used in the button 17 is a reduced profile. Laterally positioning the switch mechanisms as described herein can decrease the profile of the button 17 and overall switch assembly, which may be preferred for mobile devices that have limited space. It can also be seen in
Yet another perceived advantage of the contact pad and dome switches used in the button 17 as shown is the tactile feedback provided. By having the two switches physically isolated from one another through lateral placement, the user experiences two distinct tactile responses from the button 17, each originating from a different location. In Stage 1, the user receives a hard-stop tactile signal in the location directly above the contact pad switch region. In Stage 2, the user receives a separate sensation of tactile feedback comprising of the push key 300 bending downwards or flexing over the dome switch 314, and the push key 300 reaching a second hard stop in the dome switch region. This distinct tactile feedback may be accomplished using several components which are mechanically robust.
It will be appreciated that the tactile experience for a user may vary according to a range of factors including, but not limited to, the size of the finger 400, the size of the button 17, and the way in which the user presses down on the button 17.
It will be appreciated that the particular embodiments shown in the figures and described above are for illustrative purposes only and many other variations can be used according to the principles described. Although the above has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art as outlined in the appended claims.
This application claims priority from U.S. Application No. 61/103,774, filed on Oct. 8, 2008 the contents of which are incorporated herein by reference.