CN1930854A - variable structure device - Google Patents

Abstract

A variable configuration apparatus has components or subsystems. At least some of the components (200 and 201) have mechanical coupling elements (101 and 102 and 103) that enable the structure of the device to be changed by changing at least one of the relative orientation and position of the components or subsystems. These mechanical coupling elements (101 and 102 and 103) incorporate wireless signal coupling elements (205 and 206) that cooperate to provide a wireless coupling that enables wireless coupling between components. Wireless coupling may be used to transfer at least one of data and power between components. The wireless signal coupling element may be a capacitive coupling element that provides capacitive coupling between the component and the subsystem. In one example, the device is a camera, and one component or subsystem is a display screen (201), and another component or subsystem is the body (200) of the camera (200).

Description

variable structure device

The present invention relates to a variable configuration device in which components or subsystems of the device are mechanically coupled such that the configuration of the device can be changed by changing at least one of the relative orientation and position of the components or subsystems.

In particular, the present invention relates to a variable configuration device in which it is desired to transfer at least one of data and power between components or subsystems. For example, one of the components or subsystems may be a user interface such as a display, while the other may be the main body or other functional components of the device. Examples of such devices are video cameras, laptop computers and personal data assistants (PDAs), video display units, screen-based GPS systems and electronic test equipment, and other screen-based systems or units or other devices with similar components or mechanisms. device. The mechanical coupling may be, for example, a rotary hinge assembly or a sliding mechanism.

The device uses a multi-wire cable connection (such as a flat ribbon cable) coupled between relatively movable components through multi-pin connectors provided at each end of the cable to transfer between components or subsystems. Signals such as data signals. However, relative movement between mechanically coupled parts is necessary whenever the configuration of the device is changed. Over time, the stress and strain imposed on the multi-wire connection by the repeated movement can cause stress on the movable elements and/or the connection interface used to attach the multi-pin connector to each end of the cable connection. destroy.

In one aspect, the invention provides an apparatus having mechanically coupled components or subsystems, wherein the mechanical coupling is associated with a wireless signal coupling that enables wireless coupling of signals between the components or subsystems.

In one aspect, the invention provides an apparatus comprising a plurality of components or subsystems with corresponding mechanical coupling elements that are mechanically coupled to enable changing the structure of the device, and wherein each of the first and second mechanical coupling elements provides a corresponding signal coupling means, and the signal coupling means cooperate to effectuate a signal from one of the components or subsystems to the other or to the Wireless coupling of yet another component or subsystem of a device.

In an embodiment, the invention provides a portable device comprising first and second components having respective first and second mechanical coupling elements cooperating to mechanically ground coupling first and second components, so as to allow at least one of the first and second components to move relative to the other, wherein each of the first and second mechanical coupling elements provides a corresponding signal coupling means, and the signal coupling The means cooperate to effectuate wireless coupling of a signal from one of the first and second components to the other of the first and second components.

In an embodiment, each signal coupling arrangement comprises at least two signal coupling elements. Each signal coupling element is associated with a mechanical coupling element forming a signal coupler. The signal coupling means may be incorporated in the mechanical coupling. For example, the respective mechanical coupling element may carry the signal coupling means, or the signal coupling means may form part of the respective mechanical coupling element.

In an embodiment at least one component or subsystem has data providing means for transmitting data to another component or subsystem or to a further component or subsystem within the device via wireless coupling provided by the signal coupling means.

In an embodiment, at least one component or subsystem of the device has signal supply means coupled to the signal coupling means for supplying the signal to be coupled via wireless coupling to another component or subsystem or to a signal within the device. A further component or subsystem, and at least one component or subsystem, are arranged to transmit data to another component or subsystem or to a further component or subsystem within the device by modulating the signal.

In an embodiment, at least one component or subsystem has power deriving means for deriving power from a signal coupled to the component or subsystem via wireless coupling from another or a further component or subsystem within the device. power to the component or subsystem. The power harvesting means may comprise rectification means or rectification means and charge storage means.

Typically, the signal coupling means comprises electrical signal coupling means providing capacitive or inductive wireless coupling.

The degree of coupling between said signal coupling means may vary with the relative position and/or orientation of components or subsystems, and determining means may be provided to determine the degree of coupling. For example, determining means may be provided to determine information related to the relative positions and/or orientations of components or subsystems within the device.

The mechanical coupling element may comprise at least one of a rotatable and a slidable mechanical coupling.

A mechanical coupling element may provide the coaxial part of the hinge. As another possibility, the mechanical coupling element may define a ball and socket arrangement. As a further possibility, the mechanical coupling element may provide a sliding mechanical coupling, allowing one component or subsystem to slide relative to another or a further component or subsystem within the device.

Although generally components or subsystems within devices of the present invention remain relatively movable in some cases, once a mechanical coupling is formed, the relative position and/or orientation of the components or subsystems may be fixed.

Parts can be subsystems or subassemblies. For example, a component may be a user interface device such as a display device, or a user input device such as a keyboard, or an access control device such as a locking mechanism.

The variable configuration device may be a portable device. For example, the device may be, for example, a laptop computer, PDA, video display unit, video camera, or GPS system or electronic test equipment, other screen-based systems or units, or other devices with similar components or mechanisms.

The present invention also provides a method of wirelessly coupling a signal from a first component to a second component that is mechanically coupled to the first component to allow movement of at least one of the first and second components relative to the other , the method includes wirelessly coupling the signal from the first component to the second component via mechanical coupling of the first and second components.

Devices embodying the invention allow for a greater level of stress isolation between relatively movable components or subsystems by virtue of wireless coupling, which reduces stress-based failure.

Embodiments of the present invention allow increased flexibility so that different components or subsystems may be used without any need to replace the mechanical or electrical connectors that are typical in the system. For example, where the device comprises a camera and the mechanically coupled parts comprise a camera body and a display screen, the screen may be replaced with a different screen or a different functional unit, and between the main body of the camera system and the new screen or functional unit use the same wireless data and power transfers between them.

It should be noted that the use of wireless coupling itself has been suggested previously. So, for example, WO 00/31676 describes capacitive coupling of a piece to a game board to enable data transfer between a piece and a microprocessor. WO 02/093881 uses a form of wireless coupling to transfer data between the system and a separate attachable component or fascia. US 5,455,466 describes a system in which a portable device is recharged via an inductive link which is also used to transfer data to a second electronic device. DE19542214 describes a communication system comprising a central communication unit and at least one cable-free peripheral communication unit that communicates wirelessly by using electromagnetic coupling, where power is transferred to the peripheral by magnetic coils using bandpass filters communication device. JP2001033136 describes a refrigerator in which electromagnetic inductive coupling enables information to be transmitted between the refrigerator body and the door. WO 00/30267 describes a cellular phone with a flip connected to the phone body via a hinge assembly, and describes the transfer of radio signals by capacitive coupling between a first antenna on the body and a second antenna on the flip. DE 19940374 describes a data transmission method in which a transponder is activated and its data is updated by a high frequency (HF) field supplied by a mobile data detection device.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 shows a simplified perspective view of a first embodiment of a device according to the invention in the form of a video camera incorporating a first form of capacitive wireless coupling in a rotatable mechanical coupling between the display screen and the body of the video camera;

FIG. 2 shows an exploded simplified perspective view of the camera shown in FIG. 1 to illustrate in more detail the mechanical coupling and capacitive wireless coupling between the display screen and the main body of the camera;

Figure 3 shows a diagram for explaining the operation of the capacitive wireless coupling shown in Figures 1 and 2;

Figure 4 shows a simplified perspective view of a second embodiment of the device according to the invention in the form of a video camera, in which a second form of capacitive wireless coupling is incorporated in the rotatable mechanical coupling between the display screen and the body of the video camera;

Figure 5 shows an exploded simplified perspective view of the camera shown in Figure 4 to illustrate in more detail the mechanical coupling and capacitive wireless coupling between the camera's display screen and the main body;

Figure 6 shows a cross-section through the mechanical coupling shown in Figure 5 to illustrate the combination of capacitive wireless coupling in the mechanical coupling;

Figure 7 shows a diagram for explaining the operation of the capacitive wireless coupling shown in Figures 4, 5 and 6;

Figure 8 shows a cross-sectional view through part of another device embodying the invention with a capacitive wireless coupling incorporated in a ball-and-socket mechanical coupling;

Figure 9 shows a cross-sectional view of a capacitive wireless coupling similar to Figure 8 but with a modification incorporated in a ball and socket mechanical coupling;

Figure 10 shows a simplified perspective view of another embodiment of the device according to the invention in the form of a portable electronic device having a part forming a slidable mechanical coupling between the body of the device and the cover of the device capacitive wireless coupling;

Figure 11 shows a functional block diagram of an apparatus implementing the present invention for illustrating communication via wireless coupling;

Figure 12 illustrates how data and power may be transmitted over a wireless coupling of a device embodying the invention;

Figure 13 shows a diagrammatic perspective view of an inductive wireless coupling that can replace the capacitive wireless coupling shown in Figures 1 to 3; and

FIG. 14 shows a diagrammatic perspective view of an inductive wireless coupling that can replace the capacitive wireless coupling shown in FIGS. 4 to 6 .

Referring now to the drawings, FIGS. 1 and 2 illustrate a video camera 210 embodying the present invention, wherein a mechanical coupling 202 is provided between the body 200 of the video camera 210 and a rotatable display screen 201, wherein the arc X in FIG. The angle by which the main body of the camera is rotated. In the mechanical coupling 202 are combined capacitive wireless couplings 205 and 206 , by means of which the display screen 201 obtains power and by means of which data is transmitted between the main body 200 and the display screen 201 .

For the sake of simplicity, most of the conventional parts of the camera, such as the lens and operation switches, etc., are omitted in Figures 1 and 2.

As shown in FIGS. 1 and 2 , the mechanical coupling between the main body and the display screen is in the form of a hinge assembly 202 as is conventional for such cameras. However, in accordance with the present invention, the multi-wire cable connection (typically a flat ribbon cable) normally provided within the hinge assembly to electrically connect the body and display is replaced by capacitive wireless coupling.

As can be seen most clearly in FIG. 2 , in this example the hinge assembly includes aligned but spaced apart first and second hinge members 101 , 102 carried by a main body 200 and supported by a display screen 201 . The third extended hinge member 103 is carried. Alternatively, the main body 200 may carry the third elongated hinge member 103 and the display screen 201 may carry the hinge members 101 and 102 .

The ends of the third hinge member have notched raised areas 104 and 105 which are received in corresponding complementary notched recesses of the first hinge member 101 and the second hinge member 102 (only one of which can be seen in FIG. 2 ). One 106) so that the third hinge member 103 can rotate about its axis relative to the first and second hinge members. Thus, the axis of the third hinge member defines the axis of rotation of the display screen 201 relative to the main body 200 of the camera. In this example, capacitive wireless coupling includes two capacitive couplers, each capacitive coupler consisting of two capacitive coupling elements separated by a dielectric. Each capacitive coupling element is a circular conductive plate 205 or 206 . The capacitive coupling element 205 is fitted into the recess 106 of the first and second hinge members, and the capacitive coupling element 206 is carried by the raised area 104 of the third hinge construction 103 to define two sets of parallel and spaced apart conductive plates. , the conductive plate is coaxial with the axis of rotation of the hinge. The dielectric may simply be air, or may be any suitable material that provides the required dielectric and tribological properties, such as polyethylene or polytetrafluoroethylene (PTFE), which has the advantage of a very low coefficient of friction, for example. Class plastic materials, or ceramic materials.

Although not shown in FIGS. 1 and 2 , a first electrical connection is formed between the circuitry within the main body 200 and the capacitive plate 205 fitted into the recess 106 , and the circuitry within the display screen is connected to the first electrical connection provided by the display screen 201 . A second electrical connection is formed between the capacitive plates 206 carried by the protruding regions 104 of the three-hinge member 103 . These electrical connections may be made, for example, by insulated wires passing through the hinge members.

Thus, capacitive wireless coupling includes two capacitive wireless couplers located within the hinge assembly, and each capacitive wireless coupler includes two parallel coaxial plates or disks 205 and 206 . A minimum of two of said capacitive wireless couplers are provided to ensure flow and return current paths. However, multiple capacitive wireless couplers may also be used.

FIG. 3 shows a diagram representing one of the pair of capacitive plates shown in FIG. 2 for explaining the operation of capacitive wireless coupling. pass $C=\frac{\mathrm{\ϵA}}{d}$ to approximate (neglecting edge effects) the capacitance between the plates 205 and 206 of a capacitive coupler, where ε = ε ₀ ε _r , ε _r is the relative permittivity (or permittivity) of the dielectric 207 material, and ε ₀ is free space (8.85×10 ⁻¹² F/m), A is the overlapping area of plates 205 and 206 , and d is the distance between plates 205 and 206 , that is, the thickness of dielectric 207 . By adjusting any one or more of ε, A, and d, the capacitance can be controlled to meet the requirements of a particular device. For example, to maximize the capacitance of a given mechanical structure, ε and A should be maximized while d is minimized. Usually d is on the order of several micrometers.

Figures 4 and 5 show simplified perspective views of another camera 510 embodying the invention, which differs from the camera described above both in the form of mechanical coupling and in the form of wireless capacitive coupling. Figure 7 shows a cross-sectional view through a portion of the device to show how capacitive coupling is incorporated into mechanical coupling.

As best shown by the exploded perspective view of FIG. 5 and the cross-section shown in FIG. Aligned but spaced first hinge member 601 and second hinge member 602 are carried, and a third elongated hinge member 603 is carried by display screen 501 . Alternatively, the third extended hinge member 603 may be carried by the main body 500 , and the first hinge member 601 and the second hinge member 602 may be carried by the display screen 501 .

The third elongated hinge member 603 is in the form of a hollow cylinder, and the spaced apart first hinge member 601 and second hinge member 602 carry cylindrical projections 607 and 608 which are received within the respective ends of the hollow cylinder. , so that the third hinge member can rotate about its axis relative to the first and second hinge members. Thus, the axis of the third hinge member defines the axis of rotation of the display screen 501 relative to the main body 500 of the camera 510 .

In this example, wireless capacitive coupling is again provided by two capacitive couplers, each having two capacitive coupling elements separated by a dielectric. However, as shown by Figures 5 and 6, in this case each capacitive coupling element is in the form of a conductive cylinder, so that each capacitive coupler consists of two coaxial cylinders separated by a dielectric. One cylinder 400 of each capacitive coupler is loaded by a corresponding one of the protruding parts 607 and 608, and the other cylinder 401 of each capacitive coupler is loaded by the inner surface of the hollow cylindrical third hinge member 603, The two cylinders 400 and 401 of each capacitive coupler are made coaxial and separated by a dielectric 407 (FIG. 6), which again can simply be air, or can be anything that provides the desired dielectric and friction properties. Suitable materials are eg plastic materials such as polyethylene or polytetrafluoroethylene ((PTFE) which has the advantage of a very low coefficient of friction), or ceramic materials.

Cylinders 400 and 401 may be provided as a conductive coating deposited, for example, onto raised portions 607 and 608 and the interior of hollow cylinder 603 or as separate conductive cylinders mounted on raised portions 607 and 608 and within hollow cylinder 603 .

Although not shown in FIGS. 4-6, a first electrical connection is formed between the circuitry within the body 500 and the capacitive cylinder 400 carried by protrusions 607 and 608, and between the circuitry within the display and the A second electrical connection is formed between the capacitive cylinders 401 carried in the third elongated hinge member 603 of 501 . These electrical connections may be made, for example, by insulated wires passing through the hinge members.

Therefore, the capacitive wireless coupling includes two capacitive wireless couplers, which are located in the hinge assembly, and each capacitive wireless coupler includes two parallel coaxial cylinders 400 and 401 . Again, although two capacitive wireless couplers are shown to ensure flow and return current paths, multiple capacitive wireless couplers could also be used.

FIG. 7 shows diagrams for explaining the operation of the capacitive wireless coupler shown in FIGS. 4-6. In this instance, by $C=\frac{2\mathrm{\π\ϵl}}{\ln \left(\frac{r_2}{r_1}\right)}$ Given the capacitance C of the coupler, as shown in Fig. 7, where r _{and r} are the radii of the two cylinders 400 and 401, l is the overlapping length of the cylinders, and ε is again ε = ε ₀ ε _r , ε _r is the relative permittivity (or permittivity) of the dielectric 407, and ε ₀ is the permittivity of free space (8.85×10 ⁻¹² F/m).

By adjusting any one or more of r ₂ , r ₁ , l and ε, the capacitance of the capacitive coupler can be controlled to meet the requirements of a particular application. Therefore, to maximize capacitance:

The dielectric gap r ₂ -r ₁ should be kept as small as possible, typically on the order of a few microns, since capacitance is inversely proportional to this parameter;

The overlapping length l of the coaxial cylindrical elements should be made as long as possible, since this directly controls the area of the equivalent capacitive plate;

The absolute value of _r should be made as large as possible for a given dielectric gap, since this directly controls the area of the equivalent capacitive plate; and

The permittivity (or permittivity) of the dielectric 407 should be as large as possible.

In the examples above, the mechanical coupling enables rotation about a single axis, and the capacitive coupling elements have circular or cylindrical symmetry. The invention may also be applied in cases where a mechanical coupling enables rotation about more than one axis, or enables movement of one part of the device relative to another.

FIG. 8 shows a cross section through a further device implementing the invention in the region of the mechanical coupling. In this example, the mechanical coupling is in the form of a three-dimensional ball-joint that is screwable in and out of the plane of the paper along arc Y and rotatable in the plane of paper along arc Z. Capacitive coupling is provided such that the outer surface 304 of the ball 302 forms one capacitive coupling element and the inner surface 305 of the ball socket 301 forms another capacitive coupling element, the two capacitive coupling elements being passed through which may be air or the above-mentioned materials. One of the dielectric 303 to separate. In this example, the ball and socket may themselves be conductive, or they may have a conductive coating to provide a capacitive coupling element. As mentioned above, to ensure the existence of flow and return paths, capacitive coupling should include at least two capacitive couplers. Where the device requires two of the ball and socket joints, this can be achieved by a ball and socket joint formed into a capacitive coupler of the form shown in FIG. 8 .

Figure 9 shows a modification of the ball and socket coupling shown in Figure 8 in which at least two separate capacitive coupling elements 307 and 308 are provided on the ball and corresponding capacitive coupling elements 306 and 309 are provided on the ball socket, To provide at least two capacitive couplers 306 and 307 and 308 and 309 . Although these capacitive coupling elements are shown as being relatively small, it will be appreciated that they should be made as large as possible without causing crosstalk to provide the corresponding capacitance of the capacitive coupler over the full range of ball joint motion required. Sufficient overlap between coupling elements over which wireless coupling will be effective. In this example, the capacitive coupling element may be provided by a conductive region deposited or applied to the ball and socket, or the region may be made part of the ball and socket during manufacture.

Although again not shown in FIGS. 8 and 9 , electrical connections to the capacitive coupling elements will be made within the body and the display screen, respectively, by insulated wires, for example passing through the ball and socket.

FIG. 10 shows a simplified perspective view of another embodiment of an apparatus according to the invention in the form of a portable electronic device 10, such as a portable digital assistant (PDA) with a main body 1 with A display screen 2 and a protective cover 3 that can slide in the W direction. The protective cover 3 incorporates circuitry such as a passive data storage device or possibly a small digital camera. In this case the capacitive wireless coupling is provided by a slidable part of the mechanical coupling.

As can be seen from Figure 10, partly through the guide rail 9 of inverted T-shaped cross-section on the bottom of the cover and partly through the elongated recess 5 provided on the bottom of the cover 3 and carried by the body To provide said slidable mechanical coupling, the complementary elongated protruding portion 5 of the inverted T-shaped cross-section guide rail 9 is arranged to be accommodated on the main body 1 when the cover is in the closed state covering the display screen 2. In the guide groove 10. Each of the elongated recess 5 and the complementary elongated protrusion 6 provides or carries elongated capacitive coupling elements 7 and 8 extending in the direction in which the cover is slidable. The dielectric is provided in this case by a small air gap between the cover and the body. The length and relative position of the elongated capacitive coupling elements 7 and 8 in the sliding direction are chosen so as to provide sufficient capacitive coupling to enable transfer between the main body 1 and the slidable cover 3 over the desired range of movement of the cover 3 power and data, wireless communication will be effective within this range. The range may depend on whether the circuitry carried by the cover 3 is designed to be active, for example when the cover is closed or when the cover is opened enough to expose the entire display. Again, electrical connections extend via the body to the elongated capacitive coupling element 7 and via the cover to the elongated capacitive coupling element 8 . Also, although again two capacitive couplers are provided to provide flow and return paths, additional capacitive couplers may also be provided.

Figure 11 shows a simplified functional block diagram of an apparatus implementing the invention for illustrating communication via a wireless coupling associated with a mechanical coupling.

Blocks 700 and 701 in FIG. 11 represent two components of the device that are coupled together by a mechanical coupling, itself represented by block 702 . In this example, the device is a video camera with a movable screen as described above with reference to Figures 1-3 or 4-7, and block 700 represents the functional parts of the body of the camera, while block 701 represents the display screen functional parts. For simplicity, the wireless coupling is shown simply as two blocks 703 and 704, with block 704 representing the return wireless coupler.

The functional components of the main body include the camera circuit 705, which has all the standard components of a camera, such as a power supply, a processor control circuit for controlling the overall operation of the camera lens assembly and camera, and for generating Data processing circuitry to display data in the form of a display. Likewise, the functional components of the display screen include display circuitry 706 with common driver circuitry for controlling the display drive of the display screen, such as an LCD (Liquid Crystal Display) driver interface, LCD driver and data memory, where the display is an LCD device. Since these functional components 705 and 706 are conventional, they will not be described.

The camera body 700 also includes power and data supply control circuitry that controls the transfer of power and data between the body and the display screen via wireless couplers 703 and 704 . The power and data supply control circuit includes an interface 707 that enables the power and data supply control circuit to communicate with the camera circuit 705 . In this example, the power and data supply control circuitry is powered by the camera power supply. This is represented in FIG. 11 by coupling the camera circuit 705 to power supply lines 730 and 731 . For simplicity, the connections to other functional components of the main body of power cords 730 and 731 are not shown in FIG. 11 . It will of course be understood that, alternatively, the power and data supply control circuit may be powered itself, for example by a battery.

The main body's power and data supply control circuitry has a main body controller 708 that communicates with the processor of the camera circuit 705 via interface 707 and controls the operations necessary to enable the transfer of data between the display screen and the main body via the wireless coupling. In this example, the display screen is not self-powered, so controller 710 also controls the supply of signals to the display screen from which it derives its power, as will be described below.

The main body's power and data supply control circuitry includes a signal generator 712 for generating an alternating current (AC) signal that is supplied to the main body capacitive coupling element of the wireless coupler 703, and a main body data transmitter 709, the main body data transmitter 709. The transmitter 709 is used to supply data to the display screen via wireless coupling. The data transmitter 709 may, for example, modulate the signal supplied by the signal generator 712 (or a separate carrier signal) according to the data supplied by the main body controller 708 to transmit data under the control of the main body controller 708, which is usually at Under the control of the camera control circuit 705 via the interface 707. Any suitable modulation scheme may be used such as amplitude, phase or frequency modulation. Also, any suitable data encoding scheme may be used, although typically NRZ (non-return-to-zero) data codes will be used. Where a split carrier signal is used, this may be, for example, a 13.56 MHz carrier signal, although different carrier signals may be used for different signal types or application requirements. The signal supplied by the signal generator 712 may be a continuous signal or a pulsed signal, in the latter case, depending on the particular device, capacitive coupling enables communication between the main body and the display screen in pulses. Signal generator 712 may form part of body data transmitter 709 .

Display 701 also includes power and data supply control circuitry. The circuit includes: a screen data receiver and demodulator 721 coupled to the capacitive coupling element of the display screen of the wireless coupler 703, for extracting the signal transmitted by the main body data transmitter 709 from the signal capacitively coupled to the display screen via the wireless coupler 703; the transmitted data; and a screen controller 720 for communicating with the display circuitry 706 to operate the display based on data extracted from the signal coupled to the display screen via the wireless coupler.

In this example, since the display screen is not self-powered, DC power for the display screen is derived from a signal capacitively coupled to the display screen via wireless coupling via a power harvester 724 coupled between power lines 732 and 733 . For simplicity, the connection of other functional components of the display screen (except display circuit 706 ) to power lines 732 and 733 is not shown in FIG. 11 .

The power harvester 724 may include a diode, a diode array, or a bridge rectifier. For example, the power harvester 724 may include corresponding diodes coupled between the display screen capacitive coupling element of the wireless coupler 703 and the display screen's power lines 732 and 733 . FIG. 12 illustrates one manner in which power harvester 724 may operate. In Fig. 12, 801 denotes the source of the AC signal which is capacitively coupled to the display screen via capacitive couplers 703 and 704, and from which power will be drawn on the coupling field. This signal is provided by signal generator 712 in FIG. 11 . In FIG. 12, the power harvester 724 includes a bridge rectifier that generates DC power from a signal capacitively coupled through wireless coupling. The amount of power that can be transferred is proportional to the frequency and capacitance of the coupling field, and for a given capacitance, the higher the frequency of the signal, the greater the conversion efficiency. In case higher frequencies are not available, the power obtained via capacitive coupling can be stored on the display side, for example by using storage capacitors, so that the stored power can then be used as required. This also has the advantage of allowing some control over power usage and allowing increased power utilization when power demand increases. The ability to provide stored power means, for example, that power can be transferred and stored while the system is "at rest". Thus, in the example shown in Figures 1-7, power can be delivered when the camera's display is in the closed configuration and the main camera is dormant. Alternatively, power can be delivered when the camera is running but the user is not using the display.

In the examples given above it was assumed that only one voltage level was applied giving capacity for 1 or 0 signals. Alternatively, multiple voltage levels may be applied to increase the possible signal and thus provide enhanced data transfer and/or power capabilities.

In this instance, the clock signal for the screen controller 720 is obtained from the clock signal independently supplied by the clock generator 711 of the main body 700 via the wireless coupler 703 through the clock restorer 723 . The clock generator 711 may be a stand-alone clock generator, or may be arranged to derive a clock signal from a crystal clock of the main body controller 708 . As another possibility, the clock restorer 723 can be capacitively coupled to the clock restorer 723 signal as described in WO02/052419, for example from the signal supplied by the signal generator 712, or from the signal via the wireless coupler 703 A clock signal is obtained from a separate carrier signal provided. As another possibility, the screen controller 720 could have a separate clock signal provider in the form of its own crystal clock, in which case the clock restorer 723 would be omitted.

The display may need to transmit data to the main body. If so, the display screen functionality will include a screen data transmitter 722 which, under the control of the screen controller 720, causes data to be supplied to the body via capacitive coupling. For example, as described in WO02/052419, WO00/31676 or WO02/093881, the screen data transmitter 722 transmits a signal (such as a signal from a signal generator or a carrier wave) to the display screen via a wireless coupler. Signal) can be modulated to transmit data. Typically, for simplicity, the screen data transmitter 722 will use the same modulation and data encoding scheme as the body transmitter, although this is not required so long as the body data receiver 710 and demodulator 710 and body controller 708 use the appropriate demodulation and decoding scheme.

As mentioned above, the body data controller 708 is a separate circuit within the camera body. However, it may be provided in whole or in part by the main camera processor of the camera circuit 705, in which case it may not be necessary to ensure compatibility between received and/or transmitted signals and the main camera processor interface 707 .

As described with reference to FIG. 11, the display screen obtains power from a signal supplied from the main body via capacitive coupling. As another possibility, the display screen could be self powered, in which case the power obtainer would be a battery and the connection to the capacitive coupling element of the wireless coupler would be omitted. Alternatively, both a battery and a separate power harvesting device for harvesting power via capacitive coupling may be provided within the display screen.

In the case of a video camera, for example, data that may need to be supplied from the camera body to the display screen assembly include lens details, image details, light detection details, etc., while data that may need to be supplied from the display screen to the camera body assembly include, for example, via the screen user command input. However, data may only need to be transmitted in one direction. For example, a subsystem may have limited intelligence and may not supply operating parameters to the main system. The required data transfer rate may eg be 10-40 Mbps (megabits per second) or 200-600 Mbps per pair of capacitive plates or eg as specified by the Video Electronics Standards Association (eg VESA MDDI specification).

The wireless capacitive couplers 703 and 704 of the device shown in FIG. 11 may be of any of the forms described above suitable for use with the particular type of mechanical coupling 702 used between the main body and the display screen. As shown in Figure 11, two capacitive couplers are provided to ensure flow and return paths on mechanical coupling. As noted above, multiple wireless couplers may be associated with one mechanical coupling, for example incorporated into a single hinge assembly. These different wireless couplers can be used to communicate the same data, or they can be used for different purposes. In case they are used for different purposes, it is possible for different couplers to have different degrees of capacitive coupling and thus achieve different data or power transfer rates. As a further possibility, different data transmission methods can be used for data transmission over different couplings.

The capacitive couplers shown in Figures 1-7 and 8 provide a constant capacitive coupling regardless of the degree of rotation, which has the advantage that the capacitive coupling is always the same regardless of any changes in the configuration of the device, which is the same as the display relative to the The degree of rotation of the camera body is irrelevant. In contrast, the degree of overlap between capacitive coupling elements and thus the degree of capacitive coupling in FIGS. 9 and 10 varies with the degree of movement or rotation.

In the case of the example shown by Figures 1-7, provided that sufficient capacitive coupling is obtained over the rotational range of the display, different geometries can be used where the degree of coupling varies with the rotation of the display (for example in order to be able to better fit the hinge assembly). As another possibility, the capacitive coupling elements in Figures 1-7 could be modified anyway so that the degree of coupling varies with the rotation of the screen. This can be achieved for example by providing metallization only around part of the surface of the non-conductive circular element (Figs. 1 and 2) or cylindrical non-conductive element (Figs. 4-6) to form the capacitive coupling element.

The advantage can be achieved that said variation of the capacitive coupling with rotation or movement enables the degree of rotation or movement to be determined. Accordingly, one of the body and screen controllers 708 and 720 may be configured to determine the coupling capacitance and compare it to a reference capacitance to determine the degree of rotation (in the case of FIG. 10 , movement) of the display or cover relative to the body. This can determine when the lid in Figure 10 is open or closed and when the display screen in Figures 1-7 is fully rotated or closed. One or the other of the controllers 708 and 720 may use this information about the relative orientation or position of the two components or subassemblies in determining what data may be transferred, so that, for example, only when the display is fully exposed (FIG. 1- 7 or the cover is fully open in Figure 11), or only when the display is not rotated or when the cover is closed, or for example to determine when power can be delivered, such as when the display is fully covered hour.

As mentioned above, wireless coupling is capacitive. Capacitive coupling can be replaced by inductive coupling.

Figure 13 illustrates an inductive coupler that may be used in place of the capacitive coupler shown in Figures 1-3. In this case the inductive coupler consists of two inductive coupling elements in the form of coaxial planar coils 801 and 802 . The efficiency of this inductive coupler is primarily controlled by the distance between the two coil planes, which should be as small as possible, typically around 1 mm (millimeter).

Figure 14 illustrates an inductive coupler that may be used in place of the capacitive coupler shown in Figures 4-7. In this case the inductive coupling element is in the form of two coaxial cylindrical coils (solenoid coils) 901 and 902 .

Typically the functional components of a device using inductive couplers instead of capacitive couplers will be similar to that shown in Figure 11 except that a coil driver will be used to control the inductive coupling.

It should be apparent to those skilled in the art that the present invention has application in a variety of different forms of mechanical couplings including mechanical hinges other than those shown in FIGS. 1-7, And include other forms of mechanical coupling that allow rotation about two or more axes and/or that allow both rotation and displacement. Mechanical coupling may be direct mechanical coupling, or may be via an intermediate.

The invention may be applied to any device in which components or subassemblies are coupled by mechanical coupling such that the structure of the device can be adjusted by effecting relative rotation and/or displacement or movement between the coupled components change, and in the device at least one of data or power will be transferred between the components. In addition to the video cameras described above, examples of such devices are laptop computers and personal data assistants (PDAs), video display units, screen-based GPS systems and electronic test equipment, other screen-based systems or units or having similar components or other devices of the institution. The invention has particular application to portable devices, that is, devices such as PDAs that can be easily carried by a person, but can also be applied to larger devices, which may be removable or may be fixed in place .

The invention may also be applied in cases where components are coupled in series by respective mechanical couplings and at least one of data or power is to be transferred over at least one of the mechanical couplings. In addition, the invention may also be used in devices where two subsystems or components can move or rotate relative to each other to achieve a mechanical coupling, but where relative movement is not possible after the parts are coupled .

It will be appreciated that in each of the above-described embodiments, the degree of coupling (whether capacitive or inductive) may be modified to meet the requirements of a particular device by adjusting any of the factors controlling the degree of coupling. So, for example, depending on any one or more of the type of data being transferred, the amount of data being transferred, the rate of data transfer, the requirements for power transfer, and the number of couplers contained within or associated with a given mechanical coupling , the degree of coupling can be modified to suit the requirements. The ability to change the physical constraints within the mechanical coupling results in increased flexibility within the mechanical coupling or subassembly.

The capacitive or inductive coupling elements need not have the geometry described above, but may have any geometry compatible with the specific mechanical coupling of the device.

While separate capacitive and inductive coupling arrangements have been described above, it will be appreciated that it is possible to use both within the same device.

As mentioned above, a return coupler is required. Where at least part of the device is designed to be held by a user or touched by other grounded objects, it is possible to provide capacitive coupling in which the user or other way to provide a ground return path, thus eliminating the need for a return coupler.

It will be appreciated that for situations where coupling is required over short distances and crosstalk may be an issue, the use of a capacitive coupler is likely to be preferred, whereas for longer distance communications where crosstalk is not an issue, the use of an inductive coupler is preferred. preferred.

Embodiments provide a variable structure device having components or subsystems, at least some of which have mechanical coupling elements that enable the device to be changed by changing at least one of the relative orientation and position of the components or subsystems Structure. These mechanical coupling elements incorporate wireless signal coupling elements that cooperate to provide wireless coupling, which enables wireless coupling between components. Wireless coupling may be used to transfer at least one of data and power between components. The wireless signal coupling element may be a capacitive coupling element that provides capacitive coupling between components or subsystems. In one example, the device is a camera and one component or subsystem is a display screen and the other component or subsystem is the body of the camera.

Devices embodying the invention allow for a greater level of stress isolation between relatively movable components or subsystems by virtue of wireless coupling, which reduces stress-based failure.

The device implementing the invention allows increased flexibility so that different components or subsystems can be used without any need to replace the mechanical or electrical connectors that are typical in the system. For example, where the device comprises a camera and the mechanically coupled parts comprise a camera body and a display screen, the screen may be replaced with a different screen or a different functional unit, and between the main body of the camera system and the new screen or functional unit use the same wireless data and power transfers between them. There is no need to replace any ribbon cables or multi-wire technology. It is only necessary to bring capacitive or inductive coupling elements into the operating range. This provides interchangeability of components. Such interchangeability may have additional advantages in the context of power transfer. For example, recharging can be provided via a mechanical coupling. Thus, batteries can be replaced within one component, and power delivered to another mechanically coupled component, thus eliminating the need for a separate charging station.

Claims (21)

1. A device comprising first and second parts with respective first and second mechanical coupling elements cooperating to allow relative movement of the first and second parts, wherein each of the first and second mechanical coupling elements provides a respective signal coupling means, and the signal coupling means cooperate to effectuate a signal from one of the first and second components to the other of the first and second components A wireless coupling. 2. The device according to claim 1 , wherein each signal coupling means comprises at least two signal coupling elements, each signal coupling element being provided by a first mechanical coupling element forming a signal coupler, and the coupling elements A respective one is provided by the second mechanical coupling element. 3. A device as claimed in claim 1 or 2, wherein signal coupling means are incorporated in the mechanical coupling. 4. A device as claimed in claim 1 or 2, wherein the respective mechanical coupling element carries each signal coupling means, or each signal coupling means forms part of the respective mechanical coupling element. 5. Apparatus according to any one of the preceding claims, wherein at least one of the first and second components has data providing means for transmitting data via the wireless coupling provided by the first and second coupling means to The other of the first and second components. 6. The device according to any one of claims 1-4, wherein at least one of the first and second components has signal supply means coupled to signal coupling means for supplying a signal to be coupled via wireless coupling to the other of the first and second components, and at least one of the first and second components is arranged to transmit data to the other by modulating the signal. 7. Apparatus according to any preceding claim, wherein at least one of the first and second components has power harvesting means for deriving power from a signal coupled to the component from another component via wireless coupling for power supply for the part. 8. The apparatus of claim 7, wherein the power harvesting means comprises rectifying means. 9. The apparatus of claim 7, wherein the power harvesting means includes rectification means and charge storage means. 10. An apparatus as claimed in any preceding claim, wherein the signal coupling means comprises electrical signal coupling means providing at least one of capacitive wireless coupling and inductive wireless coupling. 11. Apparatus according to any preceding claim, wherein the degree of coupling between the signal coupling means varies with the relative position and/or orientation between the first and second components, and means for determining are provided to determine Coupling, thereby determining information related to the relative positions and/or orientations of the first and second components. 12. Apparatus according to any preceding claim, wherein the first and second mechanical coupling elements define at least one of a rotatable coupling and a slidable coupling. 13. Apparatus according to any one of claims 1-11, wherein the first and second mechanical coupling elements provide coaxial portions of the hinge. 14. The device of any one of claims 1-11, wherein the first and second mechanical coupling elements define a ball and socket arrangement. 15. Apparatus according to any one of claims 1-11, wherein the first and second mechanical coupling elements provide a sliding mechanical coupling which allows relative sliding between the first and second parts. 16. Apparatus according to any preceding claim, wherein once the mechanical coupling is established the relative position and/or orientation of the first and second components is fixed. 17. An apparatus as claimed in any preceding claim, wherein the first and second components are subsystems or subassemblies. 18. Apparatus as claimed in any preceding claim, wherein the second component is a display device. 19. Apparatus according to any preceding claim in the form of a laptop computer, PDA, video display unit, video camera, or GPS system. 20. A portable device in the form of an apparatus according to any preceding claim. 21. A method of wirelessly coupling a signal from a first component to a second component mechanically coupled to the first component to allow at least one of the first and second components to move relative to the other, The method includes wirelessly coupling a signal from the first component to the second component via mechanical coupling of the first and second components.

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