Abstract:
A method of operating a mobile communication device comprising the steps of displaying an array of selectable contacts on a display of the communication device; navigating through the selectable contacts; selecting one of the selectable contacts by; and by a single user command and depending on a user setting, placing a call to the selected contact or opening a message editor for preparation of a message with the selected contact as the intended recipient, wherein the user setting is capable of being adjusted individually for each of the contacts.

Description:
TECHNICAL FIELD 
       [0001]    The disclosed embodiments relate to mobile communication devices and their operation. The invention relates particularly to the operation of their user interfaces in order to obtain simplified presentation, selection and/or execution of functions of the mobile communication devices. 
       BACKGROUND 
       [0002]    Devices such as mobile communication devices have user interfaces, which allow their users to receive information relating to the status of the devices and to control various functions of the mobile communication devices. For example, the user interface may present information in the form of a menu of available options, which allows the user to scroll through a list of headings, each of which may provide access to a list of sub-headings or available features, eventually selecting a desired feature. 
         [0003]    As the mobile communication devices have become more and more complex, also their user interfaces have become more and more complex. The information presented to the user may be extensive and as a consequence the user may experience difficulties in navigating through the information in order to find information relating to the status of the device and to control various functions. 
         [0004]    Concurrently, the mobile communication devices have become smaller and smaller, which means that the size of their graphical user interfaces, i.e. displays, are limited, making the presentation of information yet harder. 
         [0005]    Therefore the menu structures of the user interfaces have become more complex with more hierarchical levels, which implies that finding information and controlling functions are not only more difficult, but also more time-consuming. To find a piece of information or to control a single function may involve several interactions between the user and the mobile communication device. 
       SUMMARY 
       [0006]    In one aspect, a method of operating a mobile communication device is provided, by which functions are easier to control. 
         [0007]    It is in this respect, in one embodiment, to provide such a method, which, by allowing novel user settings to be set, provides for a simpler and faster handling of the mobile communication device. 
         [0008]    In another embodiment, a method is provided, which minimizes the use of numerous menus to select from. 
         [0009]    In still a further embodiment a method is provided, by which access to basic functionality is particularly simplified. 
         [0010]    In a further embodiment a method is provided, which is flexible, reliable, and user-friendly. 
         [0011]    There are still further embodiments that provide a computer program product and a mobile communication device, respectively, which implement a method that fulfills the above objects, and a software storage medium provided for storing software, which implements the method. 
         [0012]    According to a first aspect of the invention there is provided a method of operating a mobile communication device, wherein an array of selectable contacts is displayed on a display of the communication device, navigation through the selectable contacts is performed, one of the selectable contacts is selected, and a call is placed to the selected contact or a message editor for preparation of a message with the selected contact as the intended recipient is, by a single user command, opened depending on a user setting, wherein the user setting is capable of being adjusted individually for each of the contacts. 
         [0013]    According to one embodiment, provided that the user setting has not been adjusted for the selected contact, the message editor is opened for preparation of a message with the selected contact as the intended recipient as an initial default setting. 
         [0014]    According to a second, a third, and a fourth aspect of the invention there are provided a computer program product comprising software code portions for performing the method of the first aspect of the invention, a software storage medium provided for storing the computer program product, and a mobile communication device provided for performing the inventive method or which comprises the inventive computer program product of software storage medium. 
         [0015]    The disclosed embodiments provide for an improved operation of the mobile communication device. The user settings facilitate the handling and provide more intuitive, easily understandable, and faster operation. 
         [0016]    Further characteristics of the invention and advantages thereof will be evident from the following detailed description of embodiments of the invention and the accompanying  FIGS. 1-10 , which are given by way of illustration only, and thus are not limitative of the disclosed embodiments. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIGS. 1-4  illustrate, schematically, a mobile communication device according to an embodiment of the present invention. 
           [0018]      FIGS. 1   a - c  illustrate the device in front, side, and back elevation views in a first or ready state; 
           [0019]      FIGS. 2   a - c  illustrate the device in front, side, and back elevation views in a second or active state; 
           [0020]      FIGS. 3   a - c  illustrate the device in front, side, and back elevation views in a third or standby state; and 
           [0021]      FIG. 4  illustrates housing parts of the device in an exploded view. 
           [0022]      FIG. 5  illustrates, schematically, the mobile communication device in the second or active state in greater detail. 
           [0023]      FIG. 6   a  illustrates, schematically, a software structure as used for displaying a two-directional menu on a display of the mobile communication device of  FIGS. 1-5 ; and 
           [0024]      FIG. 6   b  is a table of icons and their description as used in the menu structure of  FIG. 6   a.    
           [0025]      FIGS. 7   a - d  illustrate, schematically, a user interface of the mobile communication device of  FIGS. 1-5  at various stages during the process of placing of a call. 
           [0026]      FIGS. 7   e - f  illustrate, schematically, special functions of the user interface of the mobile communication device of  FIGS. 1-5 . 
           [0027]      FIGS. 8   a - c  illustrate, schematically, the user interface of the mobile communication device of  FIGS. 1-5  at various stages during the process of preparing and sending a message. 
           [0028]      FIGS. 9   a - d  illustrate, schematically, the user interface of the mobile communication device of  FIGS. 1-5  at various stages during the process of calling back a missed call. 
           [0029]      FIGS. 10   a - c  illustrate, schematically, the user interface of the mobile communication device of  FIGS. 1-5  at various stages during the processes of adding a new person to a list of contacts and of opening an existing contact. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0030]    With reference to  FIGS. 1-4 , a mobile communication device of an embodiment of the present invention has a product architecture divided into three main parts—an interaction part  11 , a first base part  12 , and a second base part  13 . The interaction part  11  slides in the first base part  12  and the first base part  12  slides in the second base part  13  to thereby transform the mobile communication device between three different physical as well as operational states during use. 
         [0031]      FIGS. 1   a - c  illustrate the device in a first or ready state,  FIGS. 2   a - c  illustrate the device in a second or active state, and  FIGS. 3   a - c  illustrate the device in a third or standby state. 
         [0032]    The active state is reached from the ready state by sliding the interaction part  11  upwards, e.g. by pushing a protrusion known as a push bump  15  upwards by a thumb or similar. Similarly, the ready state is reached from the active state by sliding the interaction part  11  back. The movement between the ready and active states is associated with different operational actions of the mobile communication device, which will be further described below. 
         [0033]    The third or standby state is reached from the ready state by pressing the first  12  and second  13  base parts together. The pressing together is made achievable by pressing two release buttons  16  on the sides of the mobile communication device thereby activating a release mechanism. During the pressing together, the first base part  12  slides, together with the interaction part  11 , into the second base part  13 , while a flexible rubber section  14  is compressed, until a locked position is reached. The compression of the rubber section  14  is easily seen in  FIG. 3   b.  In order to transform the mobile communication device back to the ready state the two release buttons  16  are pressed to once more activate the release mechanism, and the ready state is automatically reached: the mobile communication device extends oneself in a smooth movement caused by the flexible rubber section  14 , while returning to its decompressed condition. The movement between the ready and standby states is associated with different operational actions of the mobile communication device, which will be further described below. 
         [0034]      FIG. 4  illustrates the interaction part  11  and the first  12  and second  13  base parts in an exploded view. The interaction part  11  comprises, inter alia, several parts of a user interface of the mobile communication device: input keys, a display, and an earpiece. The first base part  12  comprises an RF unit, an antenna, and a loudspeaker; and the second base part  13  comprises baseband circuitry, the above mentioned release mechanism, a battery, a SIM-card cradle and remaining parts of the user interface: a microphone and optionally a vibrator. It shall, however, be appreciated that the division of the components among the parts  11 ,  12 , and  13  may alternatively be made in a plurality of other manners. 
         [0035]      FIG. 5  illustrates main parts of the user interface in more detail. The user interface comprises input devices such as navigation keys  51 ; a no/end key  53 ; an OK/send key  53 ; alphanumeric keys  54 ; and the above mentioned microphone  55 . The navigation keys  51  include up/down navigation keys  51   a , a horizontal navigation key  51   b,  a cancel key  51   c , a soft key  51   d , and the push bump  15 . The output devices comprise the display  56  and the earpiece  57 . 
         [0036]    The mobile communication device is provided with software for displaying a two-directional menu  58  on the display  56 , which represents a novel composition with a novel principle of interaction. It provides the user with immediate navigation, which is strongly linked to a physical interaction. The user navigates through two perpendicular arrays containing selectable functions and selectable contacts. In the vertical array the user selects a function, e.g. call or message, and in the horizontal array the user selects a contact (or a particular function, which will be described below). By transforming the mobile communication device into the active state by aid of the push bump  15  the selected combination is executed (details will be given below). Hereby, also the transformation of the mobile communication device constitutes part of the input user interface of the mobile communication device. The invention provides tangible use and immediate software interaction. In the following, these interaction aspects will be disclosed in detail. 
         [0037]      FIG. 6   a  illustrates, schematically, a software structure as used for displaying the two-directional menu  58  on the display  56  of the mobile communication device and  FIG. 6   b  is a table of icons and their description as used in the menu structure. 
         [0038]    The software structure is a two-dimensional matrix, through which the user may scroll or navigate using the up/down navigation keys  51   a  and the horizontal navigation key  51   b.  By using the up/down navigation keys  51   a  vertical scrolling or navigation is achieved and by pressing or sliding over left-hand and right-hand sides of the horizontal navigation key  51   b  horizontal scrolling or navigation is achieved. The navigation keys may be exchanged for joystick, track ball, roller or other control devices (none of which being shown here). Touch screen functionality may alternatively be used. 
         [0039]    By vertical scrolling a function is selected from a vertical array  61 , e.g. a message register containing incoming and outgoing messages, a call register containing missed, incoming and outgoing calls, a call function, a message function, a details function allowing contacts to be added, deleted, and edited, a history function containing communication (calls and messages) information divided by contacts, and a settings function allowing e.g. time, alarm, ring tones, and language to be set. The functions may be divided into basic and advanced functions, e.g. the first four functions may be basic functions and the latter three functions may be advanced functions. 
         [0040]    Further functions such as a music playing function, a radio receiver function, and a picture shooting function may be provided. Similarly several separate message functions such as e.g. SMS, MMS, facsimile, and e-mail message functions, may be provided. 
         [0041]    To avoid being limited to a default telephone number and/or the complexity of selecting telephone number in a further menu for the call function, there may be provided separate functions for calling mobile and fixed-line or wire telephone numbers and/or for calling work telephone numbers and private telephone numbers. 
         [0042]    By horizontal scrolling a contact is selected from one of a plurality of horizontal arrays  62 . For the functions call, message, details, and history the contacts are preferably arranged in alphabetical order, whereas for the message and call registers, the contacts are preferably arranged in temporal, i.e. chronological, order with the last incoming or outgoing message and the last missed, incoming or outgoing call first. 
         [0043]    Each function and each contact are visualized by a respective icon as shown in the Figures. When the mobile communication device is turned on or activated after having not been used for some time, the call function (or other function) may be selected as default. Either the first contact in the list of contacts for the call function or no contact at all may be selected as a default setting. 
         [0044]    Typically, the array  61  of functions and one of the arrays  62  of contacts is displayed at a time, i.e. the array  62  of contacts belonging to the selected function. However, in an alternative version a two-dimensional matrix such as the one depicted in  FIG. 6   a  is actually displayed, possibly with the array  62  of contacts belonging to the selected function differentiated from the other arrays of contacts. When the settings function is selected, no row of contacts is displayed. 
         [0045]    Typically, the function and contact icons are moved during scrolling and a function is selected by moving its icon vertically to a particular position of the display, i.e. the position at the intersection of the vertical and horizontal arrays as shown e.g. in  FIG. 5 . Similarly a contact is selected by moving it to the intersection position during the horizontal scrolling. Alternatively a function and a contact are selected by highlighting them or by marking them in any other manner, i.e. by a cursor or the like. The term selection as used in the present context should thus be understood as differentiating them from other functions and contacts. Subsequent to this, a function is executed based on the selected function and contact by means of a further user command. 
         [0046]    Further, the scrolling may be closed ended or open ended or cyclic (so that an “endless” circular scrolling is enabled). Such cyclic scrolling may be enabled in one direction only, e.g. to the right in  FIG. 5 . 
         [0047]    When having selected a basic function and a contact, the function is executed with respect to the contact by transforming the mobile communication from the ready state into the active state by aid of the push bump  15 . If the function is the call or call register function the selected contact is called and if the function is the message or message register function, message editor is opened with the selected contact as addressee allowing the user to prepare and send the message. 
         [0048]    This two-directional menu structure thus solves the problem of going in and out of menu levels, i.e., going between a first and a second level, back and forth, by merging the menu levels into one level thereby offering selection of functions and contacts simultaneously in a single menu. The advantage is that there is only one level, i.e. one user interface menu, which the user needs to relate to, thereby providing a faster and simpler navigation, selection and operation process. 
         [0049]    It shall be appreciated that the message function may comprise several message services such as e.g. SMS, MMS, facsimile, and e-mail services. In such instance there may be provided possibilities to define a default message function for each contact that should be used in the above process if more than one message address is specified for the contact. 
         [0050]    Similarly, the call and message functions may be merged to one single call/message service and in such circumstances there may be provided possibilities to define a default action (i.e. call or message) for the call/message function for each contact that should be used in the above process. If the message function is an SMS, MMS, or combined SMS/MMS function, the default action can be defined also in case the contact only contains a single mobile telephone number since the mobile telephone number constitutes the address for both a call and an SMS/MMS message. 
         [0051]    Generally, if there are several actions that can be performed for a single command, i.e. placing a fixed-line telephone call, placing a mobile telephone call, opening an SMS editor, opening an MMS message editor, opening a combined SMS/MMS editor function, opening a facsimile message editor, opening an instant messaging editor and/or opening an e-mail message editor, each being associated with a respective address type, i.e. a fixed-line telephone number, a mobile telephone number, an instant messaging address and/or an e-mail address, they could be put in a priority order as a user setting for a group of contacts. Then, the single command triggers one of the actions to be performed with respect to a selected contact, where the action to be performed is the action of highest priority that can be performed with respect to the contact, i.e. that is associated with an address type, which is among the address type or types associated with the addresses of the selected contact. For example, if the priority order is selected to be: opening an SMS editor, placing a fixed-line call, placing a mobile phone call, and opening an instant messaging editor in falling order, the action to be performed in response to the single command is opening the SMS editor provided that the selected contact has a mobile telephone number. If the selected contact only has a fixed-line telephone number, a facsimile number, and an e-mail number, the action to be performed in response to the single command is placing a fixed-line call to the selected contact. 
         [0052]    Some users, i.e. young user, almost never make telephone calls; they almost solely send messages. Therefore, some models of mobile communication devices may contain a general user setting to allow the opening of SMS editor instead of placing a call as default. The user may then adjust some contacts so that the preferred channel of communication is voice. 
         [0053]    A mobile communication device containing a prior art list of contacts, from which a user may select a given contact and then place a call by pressing a call, OK or send button, may thus be adjusted according to this aspect of the invention so that the default function will be to open a message editor instead. 
         [0054]    If the user wants to call the person, this would be possible through an option list displayed in response to a user command after having selected the contact in the lists of contacts. 
         [0055]    The remaining functions in the list of functions  61  of  FIG. 6   a  are advanced functions and can preferably only be selected when the mobile communication already is in the active state. In the ready state these functions may be differentiated, e.g. shadowed, or not displayed at all. 
         [0056]    For the functions call, message, and detail a new person contact is provided at the left-hand side of the vertical function list when the mobile communication device is turned on or activated. Choosing this contact and the call function the software prompts, upon transformation of the mobile communication device to the active state, the user to key the telephone number the user wants to call. After this the call can be placed by pressing the OK/send key. 
         [0057]    Similarly, choosing the new person contact and the message function the software prompts, upon transformation of the mobile communication device to the active state, the user to key the telephone number, to which the user wants to send a message. Thereafter the message can be prepared and subsequently transmitted in any known fashion. 
         [0058]    If the message function contains separate message functions such as e.g. SMS, MMS, facsimile, and e-mail message functions, the mobile communication device may have a default setting to run a message application of either one of the message functions upon transformation of the mobile communication device to the active state. 
         [0059]    If the call and message functions is merged to one single call/message service as depicted above, the mobile communication device may have a default setting to either place a call or to open a message editor upon transformation of the mobile communication device to the active state. 
         [0060]    If the new person contact and the details function are selected, and the combination is executed, e.g. by pressing the OK/send button  53 , the software adds a new contact to the list of contacts and the contact is opened allowing the user to fill in the contact. 
         [0061]    When having selected a particular contact first and having thereafter scrolled upwards to the call register there may be different options on how to handle the scrolling. If the particular contact exists in the call register, it may be selected automatically, and if not, the first contact in the list may be selected or no contact at all may be selected. Alternatively, the first contact in the list is selected or no contact at all is selected. When having selected a particular contact in the message or call register, this particular contact is preferably kept selected when scrolling down to any of the functions call, message, details, and history. 
         [0062]    To answer a call the mobile communication device is transformed to the active state. If the user does not want to answer the call the cancel key is pressed. If the mobile communication device is equipped to receive a number presentation, the calling party can be identified before determining whether the call should be answered or not. 
         [0063]    To place a call the user may perform in the manner described below with reference to  FIGS. 7   a - d , which illustrate, schematically, the user interface of the mobile communication device at various stages during the process of placing of the call. The call function is selected whereupon the list of contacts appears as a row to the right of the call function icon. This stage of the process is shown in  FIG. 7   a.  Then, the horizontal navigation key is used to scroll among the contacts of the contact list as shown in  FIG. 7   b.  When a particular contact is selected, this contact is shown at the intersection of the horizontal and vertical bars. In the illustrated case the contact “Alan Johnson” is selected. This stage is illustrated in  FIG. 7   c.  Finally, the call is placed by transforming the mobile communication device to the active state as shown in  FIG. 7   d.    
         [0064]    It shall be appreciated that the software of the mobile communication device provides for scrolling of functions and contacts in any order, e.g. the above call my be placed by first choosing the contact by horizontal scrolling and then choosing the function, i.e. the call function, by vertical scrolling—all in a single menu. 
         [0065]      FIG. 7   e  illustrates a particular function, which is optionally implemented. When scrolling through the list of contacts the soft key  51   d  provides the possibility to select other telephone numbers than a default telephone number for a given contact if such telephone numbers exist. If other telephone numbers than the default telephone number exist a drop-down list or a pop-up window is shown upon pressing the soft key  51   d  and another telephone number can be selected. The scrolling through the list of alternative telephone numbers may e.g. be performed by pressing the soft key  51   d  repeatedly. 
         [0066]      FIG. 7   f  illustrates another function, which is optionally implemented. When scrolling through the list of contacts some of the contact icons may be differentiated in appearance e.g. by a background glow to indicate that these contacts are frequently called contacts. The software may be provided for registering the call pattern constantly and can thereby automatically adjust the differentiation of the contact icons to match the current pattern. 
         [0067]    To prepare and send a message, the user may perform in the manner described below with reference to  FIGS. 8   a - c,  which illustrate, schematically, the user interface of the mobile communication device of  FIGS. 1-5  at various stages during the process of preparation and transmission of the message. The horizontal navigation key is used to scroll among the contacts of the contact list as is shown in  FIG. 8   a.  When a particular contact is selected this contact is shown at the intersection of the horizontal and vertical bars. In the illustrated case the contact “Alan Johnson” is selected. However, the message function has not been selected yet. Actually the call function icon is located at the intersection of the horizontal and vertical bars. The vertical navigation keys are used to scroll among the functions and in  FIG. 8   b  is shown a stage, in which the message function has been selected, and is thus located in the intersection of the horizontal and vertical bars. Finally, the message application is launched by transforming the mobile communication device to the active state as is shown in  FIG. 8   c.  As a result a message editor is shown on the display and a message can be prepared using the alphanumerical keys. When the message has been prepared it is sent to the selected contact by pressing the OK/send key. Obviously, the function can be selected before the contact as was described with reference to  FIGS. 7   a - d.    
         [0068]    All missed calls are registered and can be found under the call register function. To indicate that there exists a new missed call, the call register icon is differentiated e.g. by an animated frame such as a glowing edge and there is displayed a text informing the user of how many missed calls there are.  FIG. 9   a  illustrates schematically the user interface of the mobile communication device at this stage. The differentiation of the icon and the text are displayed until the user executes the call register function, whereupon a list of contact icons with a call history including the contacts with missed calls is displayed in the horizontal array. If there is more than one missed call from a single contact, a contact icon for that contact may appear at several positions in the list, which is, as described above, ordered chronologically. To call back a missed call, the user scrolls horizontally as shown in  FIG. 9   b  until he/she finds the contact icon associated with the missed call. When the contact icon is located at the intersection of the horizontal and vertical bars as shown in  FIG. 9   c  the call is placed by transforming the mobile communication device to the active state. In  FIG. 7   d  the mobile communication device is in its active state and the display shows the action being performed. 
         [0069]    The physical appearance of the mobile communication device when transformed into the active state is suitable for the call and message preparing functionality: the device becomes longer to provide a distance between the earpiece  57  and the microphone  55  that is approximately adapted to the distance between the ear and the mouth of a user. Further, the no/end key  53 , the OK/send key  53 , and the alphanumeric keys  54  are exposed when the interaction part  11  slides out from the first base part  12  so that they can be used e.g. for preparing a message. 
         [0070]    The functionality of adding a new contact to the list of contacts is found in the details function. Since this function is an advanced function the user has to start with transforming the mobile communication device to the active state without having selected a combination of a function and a contact as shown in  FIG. 10   a.  The user scrolls through the list of functions by using the up/down navigation keys to select the details function and scrolls through the list of contacts by using the horizontal navigation key to select the new person function. When the details function and the new person contact is located at the intersection of the horizontal and vertical bars as shown in  FIG. 10   b,  a form for adding a new person to the lists of contacts is displayed by pressing the OK/send key  53 . 
         [0071]    If on the other hand an existing contact is selected as shown in  FIG. 10   c  (“Alan Johnson”), this contact is opened by pressing the OK/send key  53 . When opened the user may use the soft key to select between editing the contact and deleting it. 
         [0072]    Next, the functionality of the third transformation state, the standby state, of the mobile communication device will be overviewed. As can be seen from  FIGS. 1-3 , the mobile communication device becomes smaller or more compact, i.e. shorter, when being transformed to the standby state. Further, the flexible rubber section  14  is slided over the navigation keys  51  to protect them. The no/end key  53 , the OK/send key  53 , and the alphanumeric keys  54  are being covered and protected by the interaction part  11  in this as well as in the ready state. 
         [0073]    Preferably, the mobile communication device is set to a standby mode when being transformed to the standby state. The standby mode indicates that the device is not being capable of being used. No calls or messages will be received, no calls can be placed, and no messages can be sent. (The RF functionality may or may not be switched off.) When the mobile communication device is transformed into the standby state, its display informs the user of the action, and afterwards the display is blank. The mobile communication device is preferably indicating discretely that it is powered on and being in the standby state. 
         [0074]    The physical transformation of the mobile communication device when placed in the standby state is suitable for the standby functionality: the device becomes compact and all keys are protected. 
         [0075]    Alternatively, the mobile communication device is set to another mode, such as flight mode (the RF functionality is switched off) or a meeting or silent mode (the ring signal is switched off) when being transformed to the standby state. 
         [0076]    If the mobile communication device is provided with applications not related to telephony, such as e.g. a music player, a radio tuner, or a camera, these may or may not be operable in the standby state. 
         [0077]    The two-directional menu and the transformation of the mobile communication device between different and operational states according to the present invention bring the functionality out to the surface of the mobile communication and thus closer to the user. The invention provides for tangible use and immediate software interaction that supports and compliments the tangibility. The transformation in length is intuitive: the longer the mobile communication device is made, the more active mode is entered. Further, the operation mode can readily bee found by visual or tactile inspection of the mobile communication device. 
         [0078]    It shall be appreciated that while the illustrated embodiment comprises three parts, which can be oriented with respect to one another in three different positions to thereby provide three different physical appearances and corresponding operational states of the mobile communication device, the invention is not limited to such version. The number of parts may be two or larger than three, and the number of physical and operational states of the mobile communication device may be two or larger than three, each being associated with a respective operational mode. For instance, four physical states of the mobile communication device may correspond to active, ready, silent, and standby modes as defined above. The parts may be oriented with respect to one another in different positions by means of sliding movements, twisting movements, folding movements, or any combination thereof. 
         [0079]    While the above embodiment contains numerous improvements and novel features, most of them can be used separately, in other contexts, or in other kinds of mobile communication devices. It shall thus be appreciated by a person skilled in the art that various changes may be made to the above embodiment without departing from the broader spirit and scope of the invention as set forth in the appended claims. The description and drawings are accordingly to be regarded in an illustrative rather than a restrictive sense.