Patent Publication Number: US-2004049743-A1

Title: Universal digital mobile device

Description:
[0001] Computer technology is entering more and more areas of life, in particular in the form of Internet technology. Whereas in earlier times the use of data processing devices was customary and widespread only for specific activities, for example for text processing, for carrying out technical/scientific design and calculation activities or for commercial accounting activities, the use of data processing devices is becoming increasingly ubiquitous in everyday life: in particular since the start of the phenomenal growth phase of the Internet from approximately 1995 onwards, interaction via the Internet using suitable data processing devices is being applied to more and more areas of life, particularly in business (“e-commerce”) and the field of public administration (“e-government”). It is increasingly customary today to perform, for example, the ordering of goods and/or services or transactions in the field of public administration, for example the submission of tax declarations, online via the Internet. At present, operations of this type are usually carried out using fixed data processing devices of the “personal computer” type. Where mobility is a factor, portable devices, for example what are referred to as “notebook” computers or “palmtop” computers, are used.  
       [0002] On the other hand, mobile telephone services have become significantly more important, not least due to falling tariffs. Mobile telephones (“mobiles”) are highly specialized data processing devices which, by means of a permanently predefined firmware, are exclusively aimed at permitting the user to perform mobile telephone services in as uncomplicated a way as possible. Recently, there has also been increased use of concepts in which mobile telephones are provided with functionalities which go beyond pure telephone services: firstly the “Short Message Service” (SMS) permits short messages of, for example, up to 160 characters to be exchanged using mobile telephones. On the other hand what are referred to as WAP mobile telephones, which are set up for the “cableless application protocol” permit the Internet, or Internet-like services, to be used, even if in a functionally restricted way.  
       [0003] “Palmtop” computers are digital mobile devices which correspond in size approximately to a mobile telephone but are not designed for making telephone calls but rather, for example, for storing and displaying personal diary data, telephone lists, etc. There is frequently no provision of an input keyboard on these devices but instead, for example, an input pen device is used for inputting small amounts of text in the form of handwriting. For this reason, palmtop computers are rather unsuitable for processing operations in which relatively large amounts of information have to be displayed simultaneously on a display or input into the device, for example the reception and dispatch of e-mail messages.  
       [0004] A further category of mobile digital devices which have recently appeared are what are referred to as “electronic books”. Such an “electronic book” is known for example from PCT/EP98/06008. This type of device typically has at least one display device with a relatively large surface area, by means of which relatively large quantities of text can also be conveniently read.  
       [0005] However, the current situation appears unsatisfactory overall: the complete functionality of Internet services can at present only be exploited with fixed PCs and with high-power notebooks. These devices are generally provided with very universal operating systems, for example, Linux MAC-OS or WINDOWS which, however, technically unskilled users regularly overload. On the other hand, customary mobile telephones are characterized by a highly function-oriented operator interface which is freed of unnecessary complexity; however, they lack the necessary universality. In particular, even in the case of WAP-capable mobile telephones, the screens are much too small for relatively complex tasks, for example, to be able to carry out text processing.  
       [0006] For this reason, there is an increased need to provide a digital mobile device which, on the one hand, is also suitable for technically unskilled users, thanks to a reduction in complexity in comparison with a conventional PC, but whose usefulness is not restricted by the drastic functional restrictions of mobile telephones, palmtops or digital books.  
       [0007] The object of the invention is therefore to provide a universal digital mobile device which can be embodied, for example, in the size of a typical book and is suitable for performing a wide variety of tasks in order thus to combine in itself the functionality of a multiplicity of devices such as a mobile telephone, digital book, palm pilot, notebook and/or Internet notepad, and thus avoid the need to carry around a multiplicity of devices, and be able to carry out respective functions in as ergonomic and user-friendly a way as possible.  
       [0008] An object of the invention is also that the abundant application possibilities obtained by combining a multiplicity of device functions should be simplified by means of a technical operator control facility in such a way that the user, as a non-expert, can operate the device easily and in a clearly organized fashion.  
       [0009] This object is achieved according to the invention by means of a universal digital mobile device such as can be found in the independent claims. Advantageous developments can be found in each of the subclaims.  
       [0010] The subject-matters of the independent patent claims each have independent inventive contents. 
     
    
    
     [0011] The invention is explained in more detail below with reference to exemplary embodiments which are introduced purely by way of example:  
     [0012]FIG. 1 shows a schematic perspective view of a digital mobile device according to the invention in three different use situations: FIG. 1A shows the inputting of a pointer position by moving the tip of a finger on a touch-sensitive surface in the manner of a “slide pad”. FIG. 1B shows the inputting of characters by means of a keyboard. FIG. 1C shows inputting of written characters by means of a pressure pen on a pressure-sensitive surface.  
     [0013]FIG. 2 shows an interface selection bar, provided in the digital mobile device according to the invention from FIG. 1, with operator controls.  
     [0014]FIG. 3 shows a plan view of a digital mobile device according to the invention from FIG. 1 in the folded-open state.  
     [0015]FIG. 4 shows a plan view of a digital mobile device according to the invention from FIG. 1 in the folded-open state.  
     [0016]FIG. 5 shows a first variant of the digital mobile device according to the invention, shown in FIG. 1, in the folded-open state, specifically a digital mobile device according to the invention with a main display part without input possibility and a main operator control part.  
     [0017]FIG. 6 shows a second variant of the digital mobile device according to the invention, shown in FIG. 1, in the folded-open state, specifically a digital mobile device according to the invention with a main display part with an input possibility provided, for example, by a touch-sensitive screen (“touchscreen”), and a main operator control part.  
     [0018]FIG. 7 shows a digital mobile device according to the invention in accordance with FIG. 5 or FIG. 6, in which the main display part and the main operator control part are separate.  
     [0019]FIG. 8 shows, in the partial FIGS. 8A to  8 E, a functional example of the use of operator controls contained in the menu bar according to FIG. 3, as multifunction keys in the basic mode.  
     [0020]FIG. 9 shows a schematic view of the functional arrangement of the multifunction key in the basic mode.  
     [0021]FIG. 10 shows a functional example of operator controls contained in the interface selection bar shown in FIG. 3, as multifunction keys and setting keys in the setting mode.  
     [0022]FIG. 11 shows a schematic view of the functional arrangement of the multifunction keys in the application mode.  
     [0023]FIG. 12 shows the principle of the selection of an application or of a document by setting up the operator interface.  
     [0024]FIG. 13 is a schematic view of the principle of the selection of an operator interface by actuating an application or a document.  
     [0025]FIG. 14 shows a perspective view of a digital mobile device according to the invention in a modular design with a hand-grip part arranged on the gripping edge.  
     [0026]FIG. 15 shows a perspective view of a book spine part without a hand-grip part and without a housing part.  
     [0027]FIG. 16 shows the mechanical interaction of a hand-grip part with a book back part.  
     [0028]FIG. 17 shows a cross-sectional view through the digital mobile device according to the invention (illustrated in FIG. 14) with a modular design.  
     [0029]FIG. 18 shows a two-leaf digital mobile device according to the invention with a display part and a touch pad of equal size, as a book cover, in the folded-open state.  
     [0030]FIG. 19 shows a perspective view of the lower edge of the mobile device according to the invention illustrated in FIG. 18.  
     [0031]FIG. 20 shows a schematic detailed view of an operator display of a digital mobile device according to the invention from FIG. 18.  
     [0032]FIG. 21 shows a cross-sectional view of the digital mobile device according to the invention from FIG. 18 in a flexible embodiment, for example, with a polymer screen.  
     [0033]FIG. 22 shows a perspective view of a two-leaf digital mobile device according to the invention in the paper clip integrated into the side edge it operator control part in the folded-open state.  
     [0034]FIG. 23 is a schematic view of the function of the paper clip in the digital mobile device from FIG. 22.  
     [0035]FIG. 24 is a schematic, cross-sectional view of the digital mobile device from FIG. 22 with a paper clip in another embodiment and with a sheet of paper clipped into position.  
     [0036]FIG. 25 shows a functional arrangement of the operator controls provided in the interface selection bar, with a setting momentary-contact switch for setting up the input area from FIG. 22 and with multifunction keys for manipulating information shown on the display.  
     [0037]FIG. 26 shows a perspective view of a two-leaf digital mobile device according to the invention with an auxiliary display, integrated in the side edge of the operator control part, for variable functional symbols.  
     [0038]FIG. 27A is a schematic view of the method of operation of operator controls, provided in the interface selection bar, in a digital mobile device according to the invention in accordance with FIG. 26 in a device for right-handed people.  
     [0039]FIG. 27B shows the arrangement from FIG. 27A with a setting for left-handed people after the display unit has been turned (upside down).  
     [0040]FIG. 28 is a schematic view of the changing assignment of the operator controls of the interface selection bar given successive activations of the changeover function.  
     [0041]FIG. 29 shows a perspective view of a two-leaf digital mobile device according to the invention with a functional symbol display in the main display part and an operator control possibility in the operator control part or in the main display part in the folded-open state.  
     [0042]FIG. 30A is a schematic view of the method of operation of operator controls which are provided in the interface selection bar, in a digital mobile device according to the invention in accordance with FIG. 29 with a setting for right-handed people.  
     [0043]FIG. 30B shows the arrangement from FIG. 29A with a setting for left-handed people after the display unit has been turned (upside down).  
     [0044]FIG. 31 is a schematic view of the changing assignment of the operator controls of the interface selection bar given successive activations of the changeover function.  
     [0045]FIG. 32 is a schematic view of a design of the input area of the main operator control part.  
     [0046]FIG. 33 shows various sequence phases when a digital mobile device according to the invention is switched on. FIG. 33A shows the switch-on operation by activating an operator control in the interface selection bar. FIG. 33B shows the digital mobile device according to the invention in a setting and self-test phase. FIG. 33C shows the digital mobile device according to the invention in a subsequent standby state.  
     [0047]FIG. 34 shows a perspective view of a two-leaf digital mobile device according to the invention in the folded-open state for use of the keyboard in the transverse format.  
     [0048]FIG. 35 is a schematic view of a use of the digital mobile device according to the invention from FIG. 34 for operating text processing software, and a deactivation lock which is to be actuated simultaneously in order to activate the keys, using a thumb.  
     [0049]FIG. 36 shows a two-leaf digital mobile device according to the invention in the folded-open state in a mode for use as a communication device, in particular mobile telephone.  
     [0050]FIG. 37 is a schematic view of a use of the digital mobile device illustrated in FIG. 36, with a plug-in mobile module as a communication device, for example for communication by means of telephone services, e-mail or videophone services.  
     [0051]FIG. 38 shows a perspective view of a two-leaf digital mobile device according to the invention in the folded-open state in an operating mode as an accessory for various applications, for inputting numbers into a marked field or for calculation applications.  
     [0052]FIG. 39 shows the digital mobile device according to the invention in FIG. 38 in a schematic view of an application in a computing program.  
     [0053]FIG. 40 shows a perspective view of a two-leaf digital mobile device according to the invention with a large touch-sensitive sliding surface (“slide pad”) for actuating and activating information in the main display part.  
     [0054]FIG. 41 shows various adaptation alternatives of the digital mobile device according to the invention illustrated in FIG. 40 in terms of use with a vertical format or transverse format and for use for left-handed and right-handed people.  
     [0055]FIG. 41A shows the adaptation for applications in which the main display part and/or the main operator control part are in the transverse format. FIG. 41B shows an adaptation of the digital mobile device according to the invention in which the main display part and/or the main operator control part are used in the vertical format for right-handed people. FIG. 41C shows the adaptation from FIG. 41B, but for left-handed people.  
     [0056]FIG. 42 shows a perspective view of a two-leaf digital mobile device according to the invention in the folded-open state and in the vertical format with a pressure-sensitive text detection zone for inputting text with a pen.  
     [0057]FIG. 43 shows the digital mobile device according to the invention from FIG. 42 with a pressure-sensitive text detection zone in an application with an Internet browser, the simultaneous use of the touch-sensitive surface (“touch pad”) [lacuna] by sliding a tip of a finger for inputting cursor positions etc.  
     [0058]FIG. 44 shows a setting [lacuna] digital mobile device according to the invention from FIG. 42, but with a main display part used in the transverse format and a main operator control part.  
     [0059]FIG. 45 is a schematic view of an application of the digital mobile device from FIG. 44 corresponding to FIG. 43, but in the transverse format.  
     [0060]FIG. 46 shows a perspective view of a two-leaf digital mobile device according to the invention in the folded-open state for the registration of the filling-in operation of paper forms.  
     [0061]FIG. 47 is a schematic view of the digital mobile device according to the invention illustrated in FIG. 46 in which a paper form is clipped into the main operator control part and is filled in manually, the form and form data with the data entered manually being displayed on the main display part.  
     [0062]FIG. 48 shows a perspective view of a two-leaf digital mobile device according to the invention in the folded-open state, which device is configured for the inputting of free-hand notes and free-hand sketches, optionally with or without paper, using the main operator control part.  
     [0063]FIG. 49 is a schematic view of an application of the digital device according to the invention illustrated in FIG. 48 for inputting a free-hand sketch or free-hand notes, but without paper.  
     [0064]FIG. 50 shows a perspective view of a two-leaf digital mobile device according to the invention in a variant with a reversible main operator control part.  
     [0065]FIG. 51 is a schematic, cross-sectional view through the digital mobile device according to the invention from FIG. 50 in various activation phases of the reversible main operator control part. FIG. 51A shows the release of the reversible main operator control part by applying finger pressure near to the edge of the device. FIG. 51B shows a phase in which the reversible main operator control part springs up on being released. FIG. 51C shows a further phase in which the reversible main operator control part is folded up and is held in a guide runner on one edge. FIG. 51D shows the reversible main operator control part in the folded-over state. FIG. 51E shows the reversible main operator control part in the engaged state in which the engagement occurs near to the hinge part.  
     [0066]FIG. 52 shows a schematic, perspective view of the digital mobile part from FIG. 50 with a compartment for utensils and the reversible part with two surfaces which can be embodied in different ways.  
     [0067]FIG. 52B shows the digital mobile device according to the invention from FIG. 50, a first side of the main operator control part with a touch pad and/or pen pad being positioned facing upward.  
     [0068]FIG. 52C shows a digital mobile device according to the invention from FIG. 50 in which, after a reversing operation, a second side of the main operator control part is positioned facing upward, said side having a real keyboard, constructed from individual activation keys, and a slide pad.  
     [0069]FIG. 52D shows a variant of a digital mobile device according to the invention from FIG. 50 in which a first side of the main operator control part has a second display.  
     [0070]FIG. 52E shows a view of the variant of the digital mobile device according to the invention from FIG. 52D, in which variant a second side of the main operator control part has a book cover without operating means.  
     [0071]FIG. 53 shows a schematic view of the ergonomic adaptation of the operator control when the way in which a two-leaf digital mobile device according to the invention is supported is changed. FIG. 53A shows a “hand-held” mode in which the digital mobile device is held freely, essentially in the manner of a book. FIG. 53B shows a “free-hand” mode in which the main operator control part is supported firmly on an underlying surface and is used as a keyboard input means or pen input means. FIG. 53C shows a “hand-held/free-hand” use in which the digital mobile device is used in a partly freely held and partly supported position.  
     [0072]FIG. 54 is a schematic view of various rotary orientation states during the handling of a digital mobile device according to the invention.  
     [0073]FIG. 55 is a schematic view of operating means within reach of the operator&#39;s holding hand for ergonomically making inputs into a digital mobile device according to the invention which is held in the hand, as a one-handed or two-handed embodiment.  
     [0074]FIG. 56 is a schematic view of the lower edge with integrated interface of the digital mobile device according to the invention illustrated in FIG. 55.  
     [0075]FIG. 57 is a schematic view of positioning possibilities of the operating means in the action region within reach of the operator&#39;s holding hand on a two-part digital mobile device according to the invention.  
     [0076]FIG. 58 is a schematic view of positioning possibilities of the operating means with a region which is in reach of the operator&#39;s holding hand on a single-leaf digital mobile device according to the invention.  
     [0077]FIG. 59 is a schematic view of the interaction between the hand and the operating means in the action region within reach of the operator&#39;s holding hand and a possible voice input means.  
     [0078]FIG. 60A is a schematic view of the action region of a first hand on the gripping edge on three sides of the display unit.  
     [0079]FIG. 60B is a schematic view of the action region of a second hand.  
     [0080]FIG. 61 is a schematic view of the interaction between the action region within reach of the operator&#39;s holding hand and the operating means on a digital mobile device according to the invention.  
     [0081]FIG. 62 is a schematic view of interaction regions of an operator&#39;s hand.  
     [0082]FIG. 63 shows a schematic view of the active regions of the operating means in the action region within reach of the operator&#39;s holding hand for single-handed or two-handed input possibilities, and left-handed and/or right-handed operator control on a two-leaf digital mobile device according to the invention.  
     [0083]FIG. 64 shows a schematic view of operating means alternatives in the action region within reach of the operator&#39;s holding hand on a two-leaf digital mobile device according to the invention. FIG. 64A shows a variant with a touch pad in the main operator control part and a separate main display part. FIG. 64B shows a variant with a touch pad or touchscreen on the main display part. FIG. 64D shows a variant with a tracker ball in the main display part. FIG. 64E shows a variant with a tracker ball in the main input part with a separate main display part. FIG. 64F shows a variant with a touch pad which is arranged in the main input part and has a separate main display part. FIG. 64G shows a variant with a touch pad or touchscreen region which is mounted on the main display part. FIG. 64H shows a variant with momentary-contact switches which are mounted on the main display part. FIG. 64I shows a variant with momentary-contact switches mounted on the main operator control part.  
     [0084]FIG. 65 shows a schematic view of operating means alternatives in the action region within reach of the operator&#39;s holding hand, relating to the interface selection, selection and activation of information on the display device on a two-leaf digital mobile device according to the invention.  
     [0085]FIG. 66 shows a schematic view of operating means in the action region within reach of the operator&#39;s holding hand, relating to keyboard operation on the back, side and/or front with additional touch pad input means with different designs on a two-leaf digital mobile device according to the invention.  
     [0086]FIG. 67 shows a perspective back view of a two-leaf digital mobile device according to the invention with combination keys on the back of the hand-grip part.  
     [0087]FIG. 68 shows a schematic view of the use of the two-leaf digital mobile device according to the invention from FIG. 67 in the manner of a book held with both hands with combination keys on the back of the main display part without a hand-grip part.  
     [0088]FIG. 69 shows a schematic view of the use of the two-leaf digital mobile device according to the invention from FIG. 68 with another method of handling.  
     [0089]FIG. 70 shows a perspective view of a two-leaf digital mobile device according to the invention which is held with two hands with pressure-sensitive regions which can be operated using a thumb.  
     [0090]FIG. 71 shows a perspective back view of a two-leaf digital mobile device according to the invention with function keys on the back, which keys lie in the region within reach of the operator&#39;s holding hand and can be activated by the holding hand.  
     [0091]FIG. 72 shows a perspective view of a two-leaf digital mobile device according to the invention which is held with the left hand and operated in the region within reach of the operator&#39;s left holding hand, the right hand operating a pen which can be used to input information.  
     [0092]FIG. 73 shows a perspective view of a two-leaf digital mobile device according to the invention which is held by a hand in the hinge region, an operator control operation on a touch pad being carried out with the other hand.  
     [0093]FIG. 74 shows a schematic view of three operator controls which are arranged on the back of the mobile device according to the invention, and their assigned functionalities.  
     [0094]FIG. 75 shows a perspective back view of a two-leaf digital mobile device according to the invention with a different embodiment of the holding-hand operating means.  
     [0095]FIG. 76 shows a perspective back view with an operator&#39;s hand arranged in the region within reach of the operator&#39;s holding hand on a digital mobile device according to the invention from FIG. 75 when an interface selection switch is pressed.  
     [0096]FIG. 77 shows various operating modes of the hand-grip part from FIG. 75 with the following functionalities: FIG. 77 a : hand-grip stabilization/protection; FIG. 77 b : interface selection switch; FIG. 77 c : touch pad/slide pad; FIG. 77 d : multifunction keys.  
     [0097]FIG. 78 is a schematic view of two different operating modes of the hand-grip part from FIG. 75.  
     [0098]FIG. 79A shows a single-leaf digital mobile device according to the invention with a hand-grip part.  
     [0099]FIG. 79B shows a two-leaf digital mobile device according to the invention with a hand-grip part.  
     [0100]FIG. 80A shows a two-leaf digital mobile part according to the invention with a permanently integrated device back part.  
     [0101]FIG. 80B shows the view from FIG. 80A but with an exchangeable device back part.  
     [0102]FIG. 80C shows the arrangement from FIG. 80A but with an exchangeable hand-grip part.  
     [0103]FIG. 81 is a schematic view of a synchronization device for screen and operator control unit after left-handed/right-handed presetting.  
     [0104]FIG. 82 is a schematic view of components of the synchronization mechanism from FIG. 81.  
     [0105]FIG. 83 is a schematic view of a first embodiment of a gravity switch on a digital mobile device according to FIG. 81 for automatic synchronization or setting of the display device and of the operator controls.  
     [0106]FIG. 84 shows the gravity switch from FIG. 83 at various angles of inclination.  
     [0107]FIG. 85 is a schematic view of an automatic setting according to FIG. 84 for right-handed people as a function of whether an application is selected in which it is necessary to make inputs or in which reading in the manner of a book is to be performed.  
     [0108]FIG. 86 shows details of the operation illustrated in FIG. 85.  
     [0109]FIG. 87 shows a third embodiment of a gravity switch for a digital mobile device according to FIG. 81.  
     [0110]FIG. 88 shows a cross-sectional view of a two-leaf digital mobile device according to the invention with a gravity switch according to FIG. 87.  
     [0111]FIG. 89 shows the gravity switch from FIG. 87 at various angles of inclination.  
     [0112]FIG. 90 shows a semi-automatic setting operation for a two-leaf digital mobile device according to the invention for a right-handed presetting with a gravity switch according to FIG. 87.  
     [0113]FIG. 91 shows a schematic cross-sectional view of a gravity switch according to a fourth embodiment with a mechanical transmission of the switching force via a tracker ball.  
     [0114]FIG. 92 shows a two-leaf digital mobile device according to the invention with a gravity switch from FIG. 91.  
     [0115]FIG. 93 shows a gravity switch according to FIG. 91 in various operating states.  
     [0116]FIG. 94 shows a mechanical setting operation of a two-leaf digital mobile device according to the invention with a gravity switch according to FIG. 91.  
     [0117]FIG. 95 -blank-  
     [0118]FIG. 96 -blank-  
     [0119]FIG. 97 -blank-  
     [0120]FIG. 98 -blank-  
     [0121]FIG. 99 -blank-  
     [0122]FIG. 100 -blank-  
     [0123]FIG. 101 -blank-  
     [0124]FIG. 102 -blank-  
     [0125]FIG. 103 shows a schematic view of a two-leaf embodiment of a digital mobile device according to the invention with a turning mechanism for a functional part.  
     [0126]FIG. 104 shows, in the partial FIGS. 104 a  to  104   e , the back view and external view of the housing of different variants of digital hand-held parts according to the invention.  
     [0127]FIG. 105 shows a schematic cross-sectional view through a housing from FIG. 104 c.    
     [0128]FIG. 106 shows a schematic view of a back part of a housing.  
     [0129]FIG. 107 shows a schematic view of exchangeable components of a modular back part of a housing.  
     [0130]FIG. 108 shows, in the partial FIGS. 108 a  to  108   c , rear views of further variants of housings of digital hand-held parts according to the invention.  
     [0131]FIG. 109 is a schematic view of the process of exchanging specific back parts on modular housing backs.  
     [0132]FIG. 110 shows, in the partial FIGS. 110 a  and  110   b , schematic views of different function zones of a modular housing of a single-leaf or two-leaf digital hand-held part according to the invention.  
     [0133]FIG. 111 shows, in the partial FIGS. 111 a  to  111   c , different aspects of a modular housing of a digital hand-held part according to the invention.  
     [0134]FIG. 112 shows an illustration of a mobile device according to the invention.  
     [0135]FIG. 113 shows an illustration of a modular hand-grip part.  
     [0136]FIG. 114 shows the modular hand-grip part from FIG. 113 when it is fitted into the rear of a piece of equipment.  
     [0137]FIG. 115 shows, in the partial FIGS. 115 a  to  115   c , a data processing device according to the invention with a wearable computer.  
     [0138]FIG. 116 shows, in the partial FIGS. 116 a  to  116   c , variants of the data processing device illustrated in FIG. 115.  
     [0139]FIG. 117 shows, in the partial FIGS. 117 a  to  117   c , a further variant of a data processing device according to the invention.  
     [0140]FIG. 118 shows a view of a first variant of a data processing system according to the invention with a wearable computer and a hand-held part which are connected to one another via a cable (FIG. 118 a ) or in a wire-free fashion (FIG. 118 b ).  
     [0141]FIG. 119 shows a highly schematic block circuit diagram of the first variant of a data processing system according to the invention which is illustrated in FIG. 118.  
     [0142]FIG. 120 shows a view of a second variant of a data processing system according to the invention with a wearable computer and a hand-held part, the hand-held part also being capable of being used independently (FIG. 120 a ) or being connected to a wearable computer (FIG. 120 b ) in a wire-free fashion and/or by means of a cable.  
     [0143]FIG. 121 shows a highly schematic block circuit diagram of the second variant of a data processing system according to the invention which is illustrated in FIG. 119.  
     [0144]FIG. 122 shows a view of a third variant of a data processing system according to the invention with a wearable expansion device and a hand-held part, the hand-held part being also capable of being used alone.  
     [0145]FIG. 123 shows a highly schematic block circuit diagram of the third variant of a data processing system according to the invention which is illustrated in FIG. 122.  
     [0146]FIG. 124 shows a perspective view of a digital mobile device according to the invention with a display part and operating part and a separate attachment.  
     [0147]FIG. 125 shows a perspective view of the attachment from FIG. 95 with a carrying bag and belt loop for use as a “wearable” device.  
     [0148]FIG. 126 shows a perspective view of the attachment and of the operator control part and display part from FIG. 95.  
     [0149]FIG. 127 shows a digital mobile device in a different embodiment as a wearable computer  127010  which can be used in particular as a multimedia player.  
     [0150]FIG. 128 shows the display and operator control unit from FIG. 127.  
     [0151]FIG. 129 shows the possibility of using the display and operator control unit from FIG. 127 for different devices and applications.  
     [0152]FIG. 130 shows a schematic perspective view of a detachable two-leaf mobile device according to the invention with a coupling mechanism in the hinge and a coupling lock which is to be inserted, using the example of a storage battery.  
     [0153]FIG. 135 TBD  
     [0154]FIG. 136 TBD  
     [0155]FIG. 137 TBD 
    
    
     [0156]FIG. 1 shows a schematic perspective view of a digital mobile device  1001  according to the invention in three different use situations. The digital mobile device  1001  comprises a first leaf part  1010  which is embodied as a main display part, a second leaf part  1020  which is embodied as a main operator control part and a hinge part  1030  which connects the first leaf part  1010  and the second leaf part  1020  so that it can pivot in the manner of a book. A region  1040  which is provided with one or more operator controls, and is referred to below as “interface selection bar” is preferably located in the main operator control part  1020 . The operator controls can be embodied, for example, as pushbutton keys.  
     [0157] Outside the interface selection bar  1040 , the main operator control part  1020  is provided with a location-sensitive and pressure-sensitive sensor device (not illustrated), i.e. the sensor device is capable of detecting pressure forces applied on the surface of the main operator control part  1020 , for example with tips  1050  of fingers or by means of a pressure pen  1060 .  
     [0158]FIG. 1A shows the inputting of a pointer position for a pointer symbol  1070  (illustrated on the main display part  1010 ) via movement of a tip of a finger on the touch-sensitive surface of the main operator control part  1010  in the manner of a “slide pad”.  
     [0159]FIG. 1B shows the inputting of characters by activating pressure-sensitive key regions  1080  on the main operator control part  1020  which are each assigned to individual keys and thus form a keyboard. In one preferred embodiment, the main operator control part  1020  has an active or passive display functionality (not illustrated) which can be used, for example, for displaying the characters respectively assigned to the key regions  1080 .  
     [0160]FIG. 1C shows the inputting of written characters using a pressure pen  1060  on the pressure-sensitive surface of the main operator control part  1020 .  
     [0161] The digital mobile device according to the invention contains a digital processor (not illustrated) with a central processor unit which can be, for example, of the INTEL Pentium type, with sufficient working and mass storage and with all the necessary peripheral modules. The software which runs on this system controls in particular the illustrated, outwardly apparent behaviour of the digital mobile device according to the invention.  
     [0162]FIG. 2 shows the interface selection bar  1040 , provided in the digital mobile device  1001  according to the invention from FIG. 1, with operator controls  2010   a  to  2010   d . The operator controls  2010   a  to  2010   d  can be embodied in particular as pushbutton keys, for example. It is also possible to use capacitively operating contactless proximity switches. In one preferred embodiment, the individual operator controls  2010   a  to  2010   d  are provided with a visual display, for example by means of a light-emitting diode (not illustrated).  
     [0163]FIG. 3 shows a plan view of an inventive digital mobile device  1001  according to FIG. 1 in the folded-open state. The digital mobile device  1001  comprises a first leaf part  1010  which is embodied as a main display part, a second leaf part  1020  which is embodied as a main operator control part, and a hinge part  1030  which connects the first leaf part  1010  and the second leaf part  1020  so that they can pivot in the manner of a book. In the main operator control part  1020  there is preferably a region  1040  which is provided with one or more operator controls  1040   a  to  1040   k  and which is referred to below as “interface selection bar”. The operator controls  1040   a  to  1040   k  may be embodied, for example, as pushbutton keys. Outside the interface selection bar  1040 , the main operator control part  1020  is provided with a location-sensitive, pressure-sensitive sensor device (not illustrated), i.e. the sensor device is capable of detecting pressure forces which are applied on the surface of the main operator control part  1020  using, for example, the fingertips  1050  or a pressure pen  1060 . The main operator control part  1020  also has a display (not illustrated) for displaying operator interfaces, i.e. individual regions (not illustrated) of the surface of the main operator control part  1020  can be marked visually by means of the display, for example in the manner of the labelling of a keyboard (not illustrated) or in some other expedient way relating to the functionality which is to be expected when they are actuated. One possible way of technically implementing the display function is to use a touch-sensitive screen (touch screen).  
     [0164] The function of the operator controls  1040   b  to  1040   e  and  1040   g  to  1040   j  is to be able to activate various operator interfaces B 1  to B 8  on the main operator control part  120  when they are activated by the user. On the main operator control part  1020  it is possible to see icons A 1  to A 9  which symbolize various applications which can be activated as a function of the respectively selected operator interface B 1  to B 8 . Fixed functionalities are assigned to the operator controls  1040   a ,  1040   f  and  1040   k . The operator controls  1040   a ,  1040   f  and  1040   k  constitute multifunction keys which serve to manipulate information displayed on the main display part  1010 .  
     [0165]FIG. 4 shows a plan view of an inventive digital mobile device  1001  according to FIG. 1 in the folded-open state with an application A 6  running. The operator interface B 3  (not represented in more detail in the drawing) is activated on the main operator control part  1020 . The main display part  1010  shows, in particular, icons F 1  to F 10 , E and D for the operator control functions which are available to the user (not illustrated) in this application A 6 .  
     [0166]FIG. 5 shows a first variant of the inventive digital mobile device  1001  (shown in FIG. 1) in the folded-open state, specifically an inventive digital mobile device with a main display part  1010  without an input possibility, and a main operator control part  1020  to be operated by the user  1050 . The user  1050  activates the operator control B 1  and as a result sets up on the main operator control part  1020  a specific operator interface (not shown in more detail on the drawing) which is assigned to B 1 . In the example illustrated, the main operator control part  1020  functions as a slide pad. The user  1050  slides the fingertip of a finger of his hand over the surface of the main operator control part  1020 . Under the control of the software (not illustrated in more detail) running in the processor (not illustrated) of the mobile device  1001 , the reaction of the mobile device to this slide pad input is displayed to the user  1050  on the main display part  1010  by, for example, a specific icon A 6  displayed on the main display part  1010  being displayed in an inverted form, said icon A 6  being arranged, in relation to the entire surface of the main display part  1010 , at a point which corresponds to the location where the finger of the user  1050  applies pressure relative to the entire surface of the main operator control part.  
     [0167]FIG. 6 shows a second variant of the inventive digital mobile device  1001  shown in FIG. 1 in the folded-open state, specifically an inventive digital mobile device with a main display part  1010  with an input possibility provided, for example, by means of a touch-sensitive screen (touch screen) and a main operator control part  1020 . The user  1050  sets up a predetermined operator interface (not shown in more detail on the drawing) by activating the operator control B 1 . The selection of the functionality which is assigned to the icon A 6  displayed on the main display part  1010  can be made directly here by the finger of the user  1050  touching the touch screen in the region of the displayed icon A 6 .  
     [0168]FIG. 7 shows an inventive digital mobile device according to FIG. 5 or FIG. 6 in which the main display part  1010  and the operator control part  1020  are mechanically separated, for example by configuring the hinge  1030  so that it can be decoupled. Such a separation enables the digital mobile device to be improved ergonomically. The main operator control part  1020  and the main display part  1010  are connected to one another electrically in a suitable way so that electrical signals can be transmitted back and forth between the two parts. This can be carried out, on the one hand, in a wire-bound fashion by means of an electric lead (not illustrated). On the other hand, wire-free methods such as infrared data transmission, for example by means of IrDA, or radio data transmission, for example by means of Bluetooth, can be used (neither of which is illustrated).  
     [0169]FIG. 8 shows, in the partial FIGS. 8A to  8 E, a functional example of the use of operator controls which are contained in the interface selection bar  1040  according to FIG. 3 as multifunction keys in the basic mode.  
     [0170] In FIG. 8A, depending on the position of the operator controls  1040   a ,  1040   f  and  1040   k  on the main operator control part  1020 , the main operator control part  1010  displays information such as “Open Finder”, “Switch on device” or “General operating help”. It proves advantageous always to assign specific basic functions to the operator controls  1040   a ,  1040   f  and  1040   k  in the illustrated way as the user  1050  can then easily remember this. If the operator control  1040   a  is activated repeatedly by the user  1050 , firstly a list of the favourite applications A 1  to A 6  is displayed. If the operator control  1040   a  is activated by the user  1050  once more, a list of various setting and configuration options B 1  to B 8  is then displayed. If the operator control  1040   a  is activated by the user  1050  once more, a list with the documents D 33 , D 21 , D 67 , D 9 , D 15 , D 18 , D 21  last modified is then displayed. If the operator control  1040   a  is activated by the user  1050  once more, the list of the favourite applications A 1  to A 6  is then finally displayed again. The icons shown in FIG. 8 are to be understood as being only symbolically representative; in practice, shapes which are graphically more meaningful may be used.  
     [0171] By subsequently activating the operator control  1040   f  as illustrated in FIG. 8B, a series of icons, which each represent a text document modified in the past with a text-processing application, are displayed on the main display part  1010  in the way described above in the illustrated exemplary embodiment.  
     [0172] By subsequently activating the operator control  1040   k  illustrated in FIG. 8C, icons which each represent a text document modified in the past with a text-processing application are displayed, as already represented in FIG. 8B. In the situation illustrated in FIG. 8C, all the documents, not just the documents last modified, are displayed.  
     [0173]FIG. 8 d  shows how a specific menu entry of a selection menu displayed on the main display part  1010  is marked with a finger of a hand of the user  1050  by activating the operator interface, actuated as a slide pad, of the main operator control part  1020 .  
     [0174]FIG. 8 e  shows how a specific icon D 26 , representing a document, of a number of icons D 25  to D 41  displayed on the main display part  1010  is marked with a finger of a hand of the user  1050  by activating the operator interface, actuated as a slide pad, of the main operator control part  1020 .  
     [0175]FIG. 9 shows a schematic representation of the functional arrangement of the multifunction key in the basic mode. By activating the actuation element  1040   a  of the interface selection bar  1040 , it is possible to activate a selection mode and deactivate it again (Finder). In this exemplary embodiment, when the operator control  1040   a  is activated a series of icons A 1  to A 3 , which each symbolize a favourite application, appear on the main display part  1010 . Activating the operator control  1040   a  once more causes a series of icons B 1  to B 8 , which each symbolize a parameter setting option, to appear on the main display part  1010 . Activating the operator control  1040   a  once more then causes a series of icons D 33 , D 21 , D 67 , D 9 , D 15 , D 18  and D 21 , which each symbolize a document from a list of documents recently modified, to appear on the main display part  1010 . If the operator control  1040   f  is activated in this state, all the documents are displayed on the main display part  1010  by means of corresponding icons. If, on the other hand, the operator control  1040   a  is activated in this state, the Finder is minimized and does not appear on the main display part  1010 . When all the documents are displayed, it is possible, by activating the operator control  1040   k , to sort the display of the documents according to different applications. By scrolling by continued activation of the operator control  1040   a , it is possible to identify and mark a specific document using the corresponding icon, which is displayed, for example, by reverse video or outlining. The selection which has thus been made can be activated by activating the operator control  1040   f , i.e. the selected document is opened with the application assigned to it and can be modified.  
     [0176]FIG. 10 shows a functional example of operator controls as multifunction keys and setting keys, contained in the interface selection bar shown in FIG. 3, in the setting mode. Here, the sequence illustrated in FIG. 10 corresponds basically to that illustrated in FIG. 8. However, whereas the emphasis in FIG. 8 is on the selection of a document by the user and the application is determined by the document selected, FIG. 10 concentrates on the selection of an application F 1  to F 4  and E and D.  
     [0177]FIG. 11 shows a schematic representation of the functional arrangement of the multifunction keys in the application mode corresponding to the sequences in FIG. 10. Initial activation of the operator control  1040  out of the basic state by the user  1050  causes a number of icons to appear on the main display part  1010 , each of said icons symbolizing the current application A 7  from the set of applications available on the mobile device  1001 , and the functional setting options F 1 , F 2 , F 3  and F 4  of said applications as well as the documents E and D last modified with this application. As a result of the operator control  1040  being activated once more by the user  1050 , a number of icons, which each symbolize applications A 1  to A 9  available on the mobile device  1001 , are made to appear on the main display part  1010 . Here, it is in particular also possible to indicate that individual applications A 6 , A 9  are active in the background in the standby mode.  
     [0178]FIG. 12 shows the principle of the selection of an application A 1 , A 2 , A 3 , A 4 , A 5 , A 6 , A 7 , A 8 , A 9  or of a document D 1 , D 2 , . . . D 24  by setting up the operator interface of the main operator control part  1020 . In this exemplary embodiment, the main display part  1010  is embodied as a touch-sensitive touch screen.  
     [0179] The partial FIGS. 1 a ,  1   b  and  1   c  of FIG. 12 show, by way of example, a sequence which is based on a device state of the mobile device  1001  in which icons symbolizing the available applications A 1  to A 9  have already been made to appear on the main display part  1010 . Activating the operator control B 3  causes a specific, assigned operator interface of the main operator control part  1020  to be activated. In the partial FIG. 1 b , only those applications A 3 , A 4 , A 7  which can be operated with the operator interface B 3  are then displayed on the main display part by means of their respective icons. By virtue of the user  1050  touching the main display part with a finger of a hand at the point at which the icon corresponding to the application A 7  is made to appear, the application A 7  is activated. The partial FIG. 1 c  illustrates how the application A 7  with the operator interface B 3  is available after the activation of A 7  in partial FIG. 1 b.    
     [0180] The partial FIGS. 2 a ,  2   b  and  2   c  of FIG. 12 show, by way of example, a sequence which is based on a device state of the mobile device  1001 , in which icons symbolizing the available applications A 1  to A 9  have not yet been made to appear on the main display part  1010 . Partial FIG. 2 b  illustrates how those applications which are compatible with the operator interface B 8  are symbolized by icons after the operator control B 8  has been activated on the main display part.  
     [0181] The partial FIGS. 3 a ,  3   b  and  3   c  of FIG. 12 show, by way of example, a sequence which is based on a device state of the mobile device  1001 , in which icons symbolizing the available documents D 1  . . . D 25  are made to appear on the main display part  1010 . Partial FIG. 3 b  illustrates how that document D 2  whose assigned application A 6  is compatible with the operator interface B 8  is symbolized by an icon after the operator control B 2  has been activated on the main display part.  
     [0182]FIG. 13 shows in a schematic view the principle of selecting an operator interface by activating an application A 1 , A 2 , A 3 , A 4 , A 5 , A 6 , A 7 , A 8 , A 9  or a document D 1 , D 2 , . . . D 24 .  
     [0183] The partial FIGS. 1 a ,  1   b  and  1   c  of FIG. 13 show, by way of example, a sequence which is based on a device state of the mobile device  1001  in which icons symbolizing the available applications A 1  to A 9  have already been made to appear on the main display part  1010 . The application A 4  is activated by activating the touch screen at the location of the icon corresponding to this application. In the partial FIG. 1 b , an operator interface is selected by activating the operator control  1040 . Here, any operator interfaces which can in fact be used are preferably highlighted visually, for example by means of background lighting using LEDs.  
     [0184] The partial FIGS. 2 a ,  2   b  and  2   c  of FIG. 13 show, by way of example, a sequence which is based on a device state of the mobile device  1001  in which icons symbolizing the available applications A 1  to A 9  have not yet been made to appear on the main display part  1010 . The partial FIG. 2 b  illustrates how the available applications A 1  to A 9  are symbolized by icons after the operator control  1040  on the main display part has been activated. The application A 1  is activated, in partial FIG. 2 b , by activating the touch screen at the location of the icon corresponding to this application.  
     [0185] The partial FIGS. 3 a ,  3   b  and  3   c  of FIG. 13 show, by way of example, a sequence which is based on a device state of the mobile device  1001  in which icons symbolizing the available documents D 1  . . . D 24  have been made to appear on the main display part  1010 . Activating the touch screen at the location of the icon corresponding to the document D 2  causes the application A 6  assigned to this document to be activated. The partial FIG. 3 b  illustrates how the document D 2  is opened and ready for editing on the main display part after the application A 6  has been activated.  
     [0186]FIG. 14 shows a perspective view of a digital mobile device  1001  according to the invention of a modular design with a hand-grip part  14010  arranged on the gripping edge. The digital mobile device  1001  according to the invention has, in particular, exchangeable book back parts  4010   a ,  4010   b.    
     [0187]FIG. 15 shows a perspective view of a book back part  4010  without a hand-grip part and without a housing part.  
     [0188]FIG. 16 shows the mechanical interplay between a hand-grip part and a book back part. In particular, FIG. 16 shows a schematic view of a housing back part  4010  with a removable grip region  4040 . The grip region  4040  is formed by an essentially U-shaped part which can be pushed onto the edge region (in the direction of the arrow) and also pulled off again.  
     [0189]FIG. 17 shows a cross-sectional view through the inventive digital mobile device  1001  which is illustrated in FIG. 14 and has a modular design. FIG. 17 shows in particular a schematic plan view of the lower edge or upper edge of an exemplary embodiment, which provides an exchangeable compressible cover region  4050   a ,  4050   b . Here, the grip region  4040   a ,  4040   b  is embodied essentially integrated with the front part of the housing, whereas the cover region  4050   a ,  4050   b  is embodied in the form of separate, removable cover shells. These cover shells  4050   a ,  4050   b  are secured under the grip region  4040   a ,  4040   b  by clamping and can be easily removed and replaced by the user by means of a sideways movement (1.) and subsequent upward movement (2.). The cover shells  4050   a ,  4050   b  are preferably provided on their upper side and lower side with a projecting spring which engages in a corresponding groove in the housing and provides protection against the ingress of dirt and moisture. The electronics  4060  are protected, for example by means of a sealing compound or by means of some other protective coating (not illustrated), to such an extent that they are not damaged even when the cover shell is replaced properly.  
     [0190]FIG. 18 shows a two-leaf digital mobile device  1001  according to the invention with a main display part  1010  and a main operator control part  1020 , embodied as a touch pad, of equal size, as a book cover, in the folded-open state. The main display part  1010  and the main operator control part  1020  are connected to one another by means of a hinge  1030  so as to be capable of folding open and shut in the manner of a book. The hinge  1030  can have interfaces, for example plug-type connectors, for electrical signals or for the purposes of supplying power, at one end or both ends. The hinge  1030  can also have devices for wire-free data communication, for example for radio transmission (for example Bluetooth) or infrared transmission (for example IrDA). That region of the hinge  1030  which lies facing the user at the top when the mobile device  1001  is folded open can preferably be provided with an operational display  20010 .  
     [0191]FIG. 19 shows a perspective view of the lower edge of the inventive mobile device  1001  illustrated in FIG. 18, with a plug-in device  19010 , arranged in the end piece of the hinge  1030 , for example for a universal serial bus, fire wire or the like and/or for external devices and equipment such as a charge station, portable computer, printer, card station or street terminal.  
     [0192]FIG. 20 shows a schematic detailed view of an exemplary operational display  20010  of a digital mobile device  1001  according to the invention from FIG. 18. This operational display is composed of three LEDs  20010   a ,  20010   b ,  20010   c  or of comparable display means. The upper LED  20010   a  indicates activity at external electrical interfaces of the mobile device  1001  by lighting up or flashing. The central LED  20010   b  indicates activity of the central processor unit (control processor, not illustrated) of the mobile device  1001  by lighting up or flashing. The lower LED  20010   c  indicates activity at external electrical interfaces of the mobile device  1001  by lighting up or flashing.  
     [0193]FIG. 21 shows a cross-sectional view of the digital mobile device  1001  according to the invention from FIG. 18 in a flexible embodiment, for example with a polymer screen. In order to produce haptics which are pleasant for the user and which are based on those which he is accustomed to from paper media, it is possible to provide a predetermined bending point  21010  at which the housing can be bent easily and resiliently in parallel with a line which is parallel with the hinge  1030 , owing to the mechanical flexibility of the housing. For this purpose, the electrical devices in the interior of the housing (not illustrated) are embodied so as to be flexible, using known technologies, in particular using flexible conductor track films. A display technology which can be executed in a way which provides mechanical flexibility, for example in the form of a polymer film screen, is used as the display device.  
     [0194]FIG. 22 shows a perspective view of a two-leaf digital mobile device  1001  according to the invention with a paper clip  2210  which is integrated in the side edge of the operator control part in the folded-open state. Here, the main operator control part  1020  of the mobile device  1001  is provided with a touch-sensitive surface, i.e. the mechanical pressure applied to the surface of the main operator control part  1020  can be sensed and evaluated by the central processor unit (not illustrated). When the mobile device is equipped in such a way, it proves particularly advantageous to provide the paper clip  22010  with which a sheet of paper (not illustrated) can be secured to the mobile device  1001 . If the user (not illustrated) uses a normal writing pen to write on the sheet of paper secured to the mobile device  1001 , the pressure paths of the mobile device can be sensed and stored with or without recognition of written characters. In particular, written characters may optionally be displayed with or without OCR conversion on the main display part  1010 .  
     [0195]FIG. 23 shows a schematic view of the function of the paper clip  22010  in the digital mobile device from FIG. 22. A strip of metal  22015  which can fold upwards in the longitudinal direction with respect to the hinge  1030  is held down in a sprung fashion on the surface of the main operator control part  1020  in the vicinity of the hinge. The piece of paper is secured between the strip of metal  22015  and the main operator control part  1020 .  
     [0196]FIG. 24 is a schematic, cross-sectional view of the digital mobile device  1001  from FIG. 22 with a paper clip  22010  in a different embodiment and with the sheet of paper  22020  clipped in position. In this exemplary embodiment, an angled piece of metal  24010  is provided which has two right-angled limbs  24010   a ,  24010   b . The first limb  24010   a  points downwards and is drawn in a sprung fashion into a corresponding recess of the main operator control part  1020 . The second limb  24010   b  is oriented parallel to the surface of the main operator control part  1020  and is used to clip the sheet of paper  22020  securely in position.  
     [0197]FIG. 25 shows a functional arrangement of the operator controls provided in the interface selection bar, with setting momentary-contact switches for setting up the input area from FIG. 22, and with multifunction keys for manipulating information on the display.  
     [0198]FIG. 26 shows a perspective view of a two-leaf digital mobile device  1001  according to the invention with a Help display  26010 , integrated in the side edge of the main operator control part  1020 , for variable function symbols. The integrated Help display  26010  has a touch-sensitive surface with a linear row of operator control points which are marked by means of icons which can be actuated in a variable way by the central processor unit (not illustrated) which controls the mobile device  1001 , said row of operator control points being oriented parallel to the axis of the hinge  1030 , having the purpose of performing operator control actions of the user and being equipped, in one preferred embodiment, with background lighting (not illustrated) which makes the individual operator control points easy to see for the user. In the simplest case, the Help display has, as a background, a film keypad (not illustrated) composed of operator control points which are arranged linearly one on top of the other and can be operated by the user by means of finger pressure. Known techniques of touch screen technology are particularly preferred for implementing the Help display  26010 .  
     [0199]FIG. 27A shows a schematic view of the method of operation of operator controls provided in the interface selection bar  1040  in an inventive digital mobile device  1001  according to FIG. 26 with a set-up for right-handed people. In particular, it proves advantageous for right-handed people if, given book-like use of the mobile device  1001 , the main display part  1010  comes to rest on the left and the main operator control part  1020  with the interface selection bar  1040  comes to rest on the right.  
     [0200]FIG. 27B shows the arrangement from FIG. 27A with a set-up for left-handed people after the display unit has been turned (upside down). In a way which is consistent with this, as a result of the turning, the main display part  1010  comes to rest on the right and the main operator control part  1020  with the interface selection bar  1040  on the left. However, if the labelling, in particular of the interface selection bar  1040 , were merely printed on, the icons which would be visible on it would be upside down from the user&#39;s point of view and could only be identified with difficulty. In contrast, configuring the interface selection bar  1040  with the Help display  26010  illustrated in FIG. 26 makes it possible to distinguish between a right-handed operating mode and a left-handed operating mode under the control of the software running on the central processor unit (not illustrated) of the mobile device  1001 . In the right-handed operating mode, the icons represented on the interface selection bar  1040  are upright from the user&#39;s point of view if the main display part  1010  comes to rest on the left and the main operator control part  1020  with the interface selection bar  1040  comes to rest on the right. In the left-handed operating mode, the icons represented on the interface selection bar  1040  are upright from the user&#39;s point of view if the main display part  1010  comes to rest on the right and the main operator control part  1020  with the interface selection bar  1040  comes to rest on the left. When the operating mode is changed, the icons are “turned upside down”.  
     [0201]FIG. 28 is a schematic view of the changing assignment of the visually displayed operator control points (operator controls) of the interface selection bar  1040  implemented by means of the Help display  26010  represented in FIG. 26, when there are successive activations of the changeover function as a result of activation of the operator control  1040   a . In particular, it is possible to implement navigation concepts in which different actuation options of the main operator control part  1020  are symbolized by means of individual icons (2.1). It is also possible to implement navigation concepts in which different applications which can run on the mobile device are symbolized by means of individual icons (2.2). It is also possible to implement navigation concepts in which different documents are symbolized by means of individual icons (2.3).  
     [0202]FIG. 29 shows a perspective view of a two-leaf digital mobile device  1001  according to the invention with a functional symbol display in the main display part  1010  and operator control possibility in the operator control part  1020  or in the main display part  1010  in the folded-open state.  
     [0203]FIG. 30A is a schematic view of the method of operation of operator controls provided in the interface selection bar  1040 , in a digital mobile device according to the invention in accordance with FIG. 29 with a setting for right-handed people.  
     [0204]FIG. 30B shows the arrangement from FIG. 29A with a setting for left-handed people after the display unit has been turned (upside down). FIG. 31 is a schematic view of the changing assignment of the operator controls of the interface selection bar  1040  given successive activations of the changeover function by means of the operator control  1040   a.    
     [0205] Overall, the representations in FIGS.  29  to  31  correspond to those in FIGS.  26  to  28 . However, with respect to the solution shown in FIGS.  26  to  28 , FIGS.  26  to  28  show an alternative in which a way of implementing the interface selection bar  1040  which is separate in terms of design technology is dispensed with. Instead, touch-sensitive display areas, embodied in the manner of a touch screen, both of the main display part  1010  and of the main operator control part  1020  assume the function of simulating a variable interface selection bar in an elongated region parallel to and near to the longitudinal axis of the hinge  1030 , suitable software configuration similarly permitting a distinction to be made between a right-handed operating mode and a left-handed operating mode.  
     [0206]FIG. 32 shows a schematic view of an exemplary type of design of the input area  1020   a  of the main operator control part  1020 .  
     [0207] In this exemplary embodiment, the input area  1020   a  of the main operator control part  1020  is divided into a number of subregions  1020   a   1  to [lacuna] 
     [0208] In particular the following are to be distinguished:  
     [0209] a first subregion  1020   a   1  which is arranged, for example, top left with labels in the vertical format and which is used as a pocket calculator keypad;  
     [0210] a second subregion  1020   a   2  which is arranged, for example, bottom left with labels in the transverse format and which is used as a telecommunication keypad; and  
     [0211] a third subregion  1020   a   3  which extends, for example, over the entire height on the right and is provided with labels in the transverse format.  
     [0212] In addition, marking zones  1021   a   4  can be seen, which delimit a fourth subregion  1020   a   4  which extends approximately centrally in the transverse direction over the width of the main operator control part  1020  and overlaps here with the first, second and third subregions  1020   a   1 ,  1020   a   2 ,  1020   a   3 .  
     [0213]FIG. 32A is a schematic view of a labelling film which is provided with suitable background lighting and is fitted with keypad-like labelling. The colouring of the labelling film and the labelling are matched to one another in such a way that when the background lighting is switched off the labelling is virtually invisible.  
     [0214]FIG. 32B shows a background lighting system  32010  which is arranged underneath the labelling film illustrated in FIG. 32A. The background lighting  32010  can be switched on and off for the individual subregions  1020   a   1 ,  1020   a   2 ,  1020   a   3  and  1020   a   4  independently of one another, under the control of the central processor unit (not illustrated) which controls the mobile device  1001 . By virtue of the fact that the background lighting can be activated separately for the individual subregions  1020   a   1 ,  1020   a   2 ,  1020   a   3  and  1020   a   4 , it is possible to provide the user with an expedient keypad input possibility with visual highlighting, as a function of the respectively selected application.  
     [0215]FIG. 32C shows a contact sensor system  31020  which is arranged underneath the labelling film and the background lighting system and has an interface selection bar  1040  which covers the entire area of the main operator control part  1020 . The contact sensor system  32020  is capable, in a preferred embodiment, of detecting the location both of instances of contact with the fingertip (keypad function) and of instances of contact with a pointed pen (pen function) precisely and signalling it to the central processor unit (not illustrated) which controls the mobile device.  
     [0216] The illustrations in FIG. 32 are only of an exemplary nature. The person skilled in the art is aware of various techniques for implementing pressure-sensitive touch screens. In particular, embodiment variants are possible in which the sequence of the layering of the subsystems varies in comparison with the example shown in FIGS. 32A, 32B and  32 C.  
     [0217]FIG. 33A shows various sequence phases when a digital mobile device  1001  according to the invention is switched on. FIG. 33A shows the switch-on process when the operator control  1040   f  is activated in the interface selection bar  1040 .  
     [0218]FIG. 33B shows the digital mobile device  1001  according to the invention in a setting and self-test phase.  
     [0219]FIG. 33C shows the digital mobile device  1001  according to the invention in a subsequent standby state.  
     [0220]FIG. 34 shows a perspective view of a two-leaf digital mobile device  1001  according to the invention in the folded-open state for use of the keyboard in the transverse format. As is apparent from FIG. 34, the background lighting system  32010  is switched on only for the subregion  1020   a   3 . The subregion  1020   a   2  with the telecommunication keypad is not illuminated. However, this does not mean that the pressure-sensitive device  32020  underneath the subregion  1020   a   2  is deactivated. In the subregion  1020   a   2 , the pressure-sensitive device  32020  acts simply as a slide pad for positioning processes to be easily carried out by the user without external devices such as a mouse being required for this purpose. However, this does not exclude the possibility of, for example, connecting a mouse externally if the user so wishes.  
     [0221]FIG. 35 is a schematic view of a use of the digital mobile device  1001  according to the invention from FIG. 34 for operating, by means of thumbs, text processing software and a deactivation lock which is to be actuated simultaneously in order to activate the keys. The mobile device preferably comprises a sound output device, for example a loudspeaker (not illustrated). If a keypad function is triggered by means of pressure from a fingertip of the hand of the user  1050  in the subregion  1020   a   3 , it is possible to provide for a reference noise, for example “click!”, “snap!” or the like, to be output in order to give the user audible feedback that the key has been successfully pressed.  
     [0222] In general, it is desirable to keep the pressure necessary to trigger the keypad as low as possible. This is the case in particular because the travel of the key may be very small, or virtually equal to zero, owing to the design of the pressure-sensitive area. It is also conceivable to use a location-sensitive proximity sensor instead of a location-sensitive pressure sensor. This can result in the problem of incorrect triggering of keypad functions, for example due to objects such as paper or the like accidentally coming into contact with the keypad, or due to inadvertent touching.  
     [0223] In one particularly preferred embodiment, it is therefore possible to provide an incorrect operation lock with which, when triggering the keypad functions, the user  1050  must simultaneously and continuously place a thumb  1050   a  on a specific region within the subregion  1020   a   3 , approximately in the centre of the outer edge of the main operator control part  1020 , in order thereby to signal to the mobile device  1001  that an actual keypad entry is being made, and for example incorrect triggering is not occurring.  
     [0224] The mobile device  1001  can be equipped with receptacle devices (not illustrated) for expansion parts. The reference  35010  refers to a plug-in document module memory. The reference  35020  refers to a plug-in system expansion module.  
     [0225]FIG. 36 shows a two-leaf digital mobile device  1001  according to the invention in the folded-open state in a mode for use as a communications device, in particular as a mobile telephone device. As is apparent from FIG. 36, the background lighting system  32010  is switched on only for the subregion  1020   a   2 . The subregion  1020   a   3  with the typewriter keypad is, like the subregion  1020   a   1  with the pocket calculator keypad, not illuminated. However, this does not mean that the pressure-sensitive device  32020  underneath this subregion  1020   a   1  is deactivated; the pressure-sensitive device  32020  simply acts in the subregion  1020   a   2  as a slide pad for the user to easily carry out positioning processes without requiring external devices such as a mouse for that purpose. However, this does not exclude the possibility of, for example, connecting a mouse externally if the user so wishes.  
     [0226]FIG. 37 is a schematic view of a use of the digital mobile device  1001  which is illustrated in FIG. 36 and has a plug-in mobile telephone module  35020  (expansion module) as a communications device, for example for communication by means of telephony, e-mail or image telephony. The associated telephone card can then be plugged in as a document card  35010 . In one preferred embodiment, the mobile telephone module  35020  can also be used separately from the mobile device  1001 . The data traffic between the mobile telephone module  35020  and the main device of the mobile device  1001  may be embodied, for example, using a radio link according to the Bluetooth standard.  
     [0227] By means of the telephony keypad in the subregion  1020   a   2  and the slide pad in the subregion  1020   a   1  and by using the display of the main display part  1010 , the user  1050  can select all the necessary functions such as telephone address book etc. and carry out his communication processes by means of suitable programs which run in the central processor unit (not illustrated) of the mobile device  1001 .  
     [0228] If the user wishes to output a text message, for example an SMS message or an e-mail, the keypad can, when necessary, be activated in the subregion  1020   a   3 .  
     [0229] A hands-free device may also optionally be provided in the mobile device  1001  according to the invention.  
     [0230]FIG. 38 shows a perspective view of a two-leaf digital mobile device  1001  according to the invention in the folded-open state in an operating mode as an accessory for various applications for inputting numbers into a marked field or for calculation applications. As is apparent from FIG. 38, the background lighting system  32010  is switched on only for the subregion  1020   a   1  with the pocket calculator keypad. The subregion  1020   a   2  with the telephony keypad is, like the subregion  1020   a   2  with the typewriter keypad, not illuminated. However, this does not mean that the pressure-sensitive device  32020  underneath this subregion  1020   a   2  is deactivated; the pressure-sensitive device  32020  simply acts in the subregion  1020   a   2  as a slide pad for the user to easily carry out positioning processes without requiring external devices such as a mouse for that purpose. However, this does not exclude the possibility of, for example, connecting a mouse externally if the user so wishes.  
     [0231]FIG. 39 shows the digital mobile device  1001  according to the invention in FIG. 38 in a schematic view when applied in a computer program running in the central processor unit (not illustrated) of the mobile device  1001 .  
     [0232]FIG. 40 shows a perspective view of a two-leaf digital mobile device.  1001  according to the invention with a large touch-sensitive sliding surface (slide pad) for actuating and activating information in the main display part. The background lighting system  32010  is deactivated for all the subregions  1020   a   1 ,  1020   a   2 ,  1020   a   3 . The entire surface of the main operator control part  1020  functions as a slide pad.  
     [0233]FIG. 41 shows various adaptation alternatives of the digital mobile device  1001  according to the invention illustrated in FIG. 40 in terms of use with a vertical format or transverse format and for use for left-handed and right-handed people.  
     [0234]FIG. 41A shows an application in which the mobile device  1001  is used in the transverse format. FIG. 41B shows an application in which the mobile device  1001  is used in the vertical format for right-handed people.  
     [0235]FIG. 41C shows an application in which the mobile device  1001  is used in the vertical format for left-handed people or in the book mode. In the book mode, the emphasis is on convenient reading on the right-hand leaf of the mobile device. In the book mode, the main input part  1020  is therefore turned over to the left-hand side even for right-handed people.  
     [0236]FIG. 42 shows a perspective view of a two-leaf digital mobile device  1001  according to the invention in the folded-open state and in the vertical format with a pressure-sensitive text detection zone  42010  for inputting text with a pen.  
     [0237]FIG. 43 shows the digital mobile device according to the invention from FIG. 42 with a pressure-sensitive text detection zone  42010  in an exemplary application with an Internet browser, the simultaneous use of the touch-sensitive surface (touch pad) [lacuna] by sliding a tip of a finger for inputting cursor positions etc. In the present example, the user  1050  uses a pressure pen  1051  to write the designation of the desired Internet URL into the text detection zone  42010 . The text written by the user  1050  is converted into a character chain (for example in ASCII or UNICODE coding) by a program, running on the central processor unit (not illustrated) of the mobile device  1001 , using an OCR (Optical Character Recognition) process.  
     [0238]FIG. 44 shows a setting [lacuna] digital mobile device  1001  according to the invention from FIG. 42, but with a main display part used in the transverse format and a main operator control part.  
     [0239]FIG. 45 is a schematic view of an application, corresponding to FIG. 43, of the digital mobile device  1001  from FIG. 44, but in the transverse format.  
     [0240]FIG. 46 shows a perspective view of a two-leaf digital mobile device  1001  according to the invention in the folded-open state for the registration of the filling-in operation of a paper form  47010 .  
     [0241]FIG. 47 is a schematic view of the digital mobile device  1001  according to the invention which is illustrated in FIG. 46 and in which the paper form  47010  is clamped into the main operator control part  1020  by means of the paper clip  22010 , and is filled in manually, the form  47010  and the form data with the data entered manually by the user  1050  using a pressure pen  1051  being displayed simultaneously on the main display part  1010 . The entire surface of the main operator control part  1020  serves as a pressure-sensitive input area and senses the writing movements of the pressure pen  1051 . For the paper form  47010 , a previously created electronic form has been loaded into the main display part  1010 . The writing on the paper form  47010  by the user is automatically transferred, as line graphics or as text data according to an OCR process, into the electronic form displayed on the main display part  1010 , and can be stored on a storage medium (not illustrated) when necessary.  
     [0242]FIG. 48 shows a perspective view of a two-leaf digital mobile device  1001  according to the invention in the folded-open state which is configured for the inputting of free-hand notes and free-hand sketches, optionally with or without paper, using the main operator control part.  
     [0243]FIG. 49 is a schematic view of an application of the digital device according to the invention illustrated in FIG. 48 with the user  1050  inputting a free-hand sketch or free-hand notes using a pressure pen  1051 , but without paper. The lines which are sensed by the pressure-sensitive surface of the main display part  1020  are displayed simultaneously on the main display part  1010  and can be stored when necessary on a storage medium (not illustrated).  
     [0244]FIG. 50 shows a perspective view of a two-leaf digital mobile device  1001  according to the invention in a variant with a reversible main operator control part  50010 . Here, one leaf of the mobile device  1001 , preferably the leaf constituting the main operator control part  1020 , is modified by means of a reversible mechanism. The reversible main operator control part  50010  comprises a reversible panel  50015 . This reversible panel  50015  may, for example, have an operator interface on one side, for example with the design illustrated in FIG. 32, and an additional display element which fills the area on the opposite side. Other configurations are possible. It is thus appropriate for certain applications to embody one side of the reversible plate  50015  as a passive stable metal surface which can serve as a robust writing support.  
     [0245] The reversible main operator control part  50010  comprises not only the reversible panel  50015  but also two guide rails, specifically an upper guide rail  50020  which is arranged in the region of the upper edge of the leaf, and a lower guide rail  50025  which is arranged in the region of the lower edge of the leaf. The reversible part  50015  has a projecting pin  50030  on one of its vertical lateral edges on its underside, and on one of its vertical lateral edges on its upper side. The pins  50030  each engage in the upper or lower guide rail  50025  so that the reversible part  50015  cannot drop out, or be removed, from the mobile device  1001  by its left vertical lateral edge, but otherwise can be moved horizontally back and forth over the full width of the leaf.  
     [0246]FIG. 51 is a schematic, cross-sectional view through the digital mobile device  1001  according to the invention from FIG. 50 in various activation phases of the reversible main operator control part  50010 .  
     [0247]FIG. 51A shows a first position of the reversible part  50015  in which the pins  50030  are oriented towards the left with respect to the hinge  1030 , and a first surface A of the reversible part  50015  points upwards. The reversible main operator control part  50010  is triggered by the pressure of a finger near to the edge  51010  of the device.  
     [0248]FIG. 51B shows a second phase in which the reversible part  50015  springs up on being released.  
     [0249]FIG. 51C shows a third phase in which the reversible part  50015  is folded up and is held in the upper or lower rails  50025  by means of the pins  50030  on the left-hand edge.  
     [0250]FIG. 51D shows the reversible part  50015  in the folded-over state in which its second surface B points upwards and the pins  50030  move towards the right-hand outer leaf edge  51010 .  
     [0251]FIG. 51E shows the reversible part  50015  in the engaged state in which the engagement occurs near to the hinge part. The surface B points upwards, and the pins  50030  are arranged near to the right-hand edge  51010 .  
     [0252] The reversible mechanism depicted is given only for the purposes of illustration. Of course, other functionally equivalent reversible mechanisms may be used. The reversible part  50015  is locked to the edge  51010  of the housing using the customary means, for example a latching snap mechanism or by means of small permanent magnets.  
     [0253]FIG. 52 shows a schematic perspective view of the digital mobile part  1001  from FIG. 50 with a utensil compartment  520010  and the reversible part  50015  with two areas A, B which may be embodied in different ways. In this variant, the overall height of the leaf element of the main operator control part  1020  is selected to be sufficiently large that in the engaged state a cavity, which can be used as a utensil compartment, for example for pressure pens  1051  or the like, is arranged underneath the reversible part  5005 .  
     [0254]FIG. 52B shows the digital mobile device  1001  according to the invention from FIG. 50, a first side of the main operator control part  1020  with a touch pad and/or pen pad being positioned facing upwards.  
     [0255]FIG. 52C shows the digital mobile device according to the invention from FIG. 52B in which, after a reversing operation, a second side of the main operator control part  1020  is positioned facing upwards, said side having a real keypad  52030 , constructed from individual activation keys, and a real slide pad  52040 . The reversible technology can therefore be used, in particular, to propose a further improved mobile device which not only has a main display  1010  and a touch pad but also a keypad  52030  and a separate slide pad  52040 .  
     [0256]FIG. 52D shows another variant of the digital mobile device  1001  according to the invention in accordance with FIG. 50 in which a first side of the main operator control part  1020  has a second display.  52050 . This second display  52050  proves particularly advantageous for mobile devices  1001  which are predominantly used as an electronic book as reading material can then be made available on both leaves.  
     [0257]FIG. 52E shows an illustration of the variant of the digital mobile device according to the invention in accordance with FIG. 50D in which a second side of the main operator control part has a book cover  52060  without display or operating means.  
     [0258]FIG. 53 shows a schematic view of the ergonomic adaptation of the operator control when the way in which a two-leaf digital mobile device according to the invention is supported is changed. FIG. 53A shows a “hand-held” mode in which the digital mobile device is held freely, essentially in the manner of a book. FIG. 53B shows a “free-hand” mode in which the main operator control part is supported firmly on an underlying surface and is used as a keyboard input means or pen input means. FIG. 53C shows a “hand-held/free-hand” use in which the digital mobile device is used in a partly freely held and partly supported position.  
     [0259]FIG. 53A shows the handling of a mobile device  1001  in the case of book-like, free-hand operator control, i.e. the mobile device  1001  is used by the user  1050  in the manner of a book which has been opened and is being held in a free-hand fashion.  
     [0260]FIG. 53B shows the handling of a mobile device  1001  with supported operator control, i.e. the mobile device  1001  is used by the user  1050  while it is resting on a supporting surface (for example a surface of a table).  
     [0261]FIG. 53C shows the handling of a mobile device  1001  with partially free-hand, partially supported operator control, i.e. the mobile device  1001  is used by the user  1050  with one leaf carried in a free hand and with one leaf resting on a supporting surface (for example a surface of a table).  
     [0262] The universal mobile device  1001  according to the invention is preferably embodied in such a way that the user  1050  can change between the modes of use illustrated in the partial FIGS. 53A, 53B and  53 C without having to perform complicated operator control interventions on the mobile device  1001  himself.  
     [0263]FIG. 54 is a schematic view of various rotary orientation states during the handling of a digital mobile device  1001  according to the invention. The two-leaf digital mobile device  1001  according to the invention, which is held in the hand, comprises a first leaf  54010  which is provided with a display  54020 , and a second leaf  54040  which is provided with a book cover  54030 , the first leaf  54010  and the second leaf  54020  being coupled by means of a hinge  50050  so that they can be opened and closed in the manner of a book.  
     [0264]FIG. 54A illustrates a first orientation of the mobile device  1001  in which the second leaf  50040  provided with the book cover  54030  is arranged on the right and is held by the user&#39;s right hand.  
     [0265]FIG. 54B illustrates a rotational process which is performed manually by the user  1050  and with which the mobile device  1001  is placed upside down.  
     [0266]FIG. 54C illustrates a second orientation of the mobile device  1001  in which the second leaf  50040  which is provided with the book cover  54030  is arranged on the left and is held by the left hand of the user  1050 .  
     [0267]FIG. 55 is a schematic view of operating means within reach of the operator&#39;s holding hand for ergonomically making inputs into a two-leaf digital mobile device  1001  according to the invention which is held in the hand and has a first leaf  54010  provided with a display  54020 , and a second leaf  54040  provided with a book cover  54030 , the first leaf  54010  and the second leaf  54020  being coupled by means of a hinge  50050  in the manner of a book so that they can be opened and closed.  
     [0268] The two hinge ends  50050   a  and  50050   b  can be provided with electrical plug-in connector devices (not illustrated) or wire-free data transmission devices, in particular infrared transmitters (for example IrDA, not illustrated). So that these interfaces function both in a left-handed operating mode and in a right-handed operating mode without cables becoming entangled or impediments to the wire-free data transmission, it is particularly advantageous to provide the electrical plug-in connector devices and/or wire-free data transmission devices at both ends  50050   a ,  50050   b  of the hinge  50050 .  
     [0269] A region  54010   a ,  54040   a  within reach of the operator&#39;s holding hand is entered, approximately half the way up, on each of the leaves  54010  and  54040 , shown in each case by broken lines at the corresponding outer edge of the leaf facing away from the hinge  50050 . The regions  54010   a ,  54040   a  within reach of the operator&#39;s holding hand are here those regions on the surface of the leaves  54010 ,  54040  which the user  1050  of the mobile device  1001  can comfortably reach with the fingers of his hand without having to change the position of the rest of his hand relative to the mobile device  1001  when he holds the mobile device in his hands in the manner of a book.  
     [0270]FIG. 56 is a schematic view of the lower edge with an integrated interface of the digital mobile device  1001  according to the invention illustrated in FIG. 55 with an electric plug-in connection  56010 , for example according to the USB standard or according to the “fire wire” standard, integrated in the underside  50050   b  of the hinge  50050 . It is also possible to provide a jack plug mechanism. In addition, it proves advantageous to provide an electrical power supply connection to a power supply unit (not illustrated).  
     [0271]FIG. 57 is a schematic view of positioning possibilities of operating means in the action region within reach of the operator&#39;s holding hand on a two-part digital mobile device  1001  according to the invention with a first leaf  54010  provided with a display  54020 , and a second leaf  54040  provided with a book cover  54030 , the first leaf  54010  and the second leaf  54020  being coupled by means of a hinge  50050  in such a way that they can be opened and closed in the manner of a book.  
     [0272] A holding-hand action region  54010   b ,  54040   b  is entered on each of the leaves  54010  and  54040 , as shown in each case by broken lines on the corresponding outer edge of the leaf facing away from the hinge  50050 . The holding-hand action regions  54010   b ,  54040   b  are here those regions on the surface of the leaves  54010 ,  54040  which the user  1050  of the mobile device  1001  can comfortably reach with the fingers of his hand when he holds the mobile device in his hands in the manner of a book.  
     [0273] The holding-hand action regions  54010   b ,  54040   b  mark those regions of a mobile device  1001  according to the invention on which operator controls which are to be activated when the user  1050  holds the mobile device  1001  in his hands can preferably be arranged both on the side facing the user  1050  and on the reverse side.  
     [0274]FIG. 58 is a schematic view of positioning possibilities of the operating means with a region which is in reach of the operator&#39;s holding hand on a single-leaf digital mobile device  1001   a  according to the invention. Here too, similarly to the conditions described with respect to a two-leaf device in FIG. 57, two holding-hand action regions  58010   a ,  58010   b  are indicated.  
     [0275]FIG. 59 is a schematic cross-sectional view, for example along the line A-A′ in FIG. 57, of the interaction between the hand and operating means in the holding-hand action region as well as of possible voice inputting means. The reverse side of the leaf  54010  is designated by the reference symbol R, and the front side of the leaf  54010  is designated by the reference symbol V.  
     [0276]FIG. 60A is a schematic view of the action region of a left hand on the gripping edge on three sides of a first leaf (not illustrated in more detail).  
     [0277]FIG. 60B is a schematic view of the action region of a right hand on the gripping edge on three sides of a second leaf (not illustrated in more detail).  
     [0278] In FIGS. 60A and 60B, a side wall is provided in each case with the reference symbol S. Correspondingly, a front side is provided with the reference symbol V and a rear side with the reference symbol R.  
     [0279] In a two-leaf mobile device  1001 , two corresponding action regions  60010   a  and  60010   b  with a total of two front side faces V, two reverse side faces R and two side faces S are available in the holding-hand action regions  54010   b ,  54040   b  indicated in FIG. 57, in order to arrange easy-to-operate operating means (not illustrated in more detail), that is to say a total of six faces. It is also possible to make use of just a subset of these faces for the arrangement of operating means.  
     [0280]FIG. 61 is a schematic view of the interaction in the holding-hand action region between a hand of the user  1050  and an operating means in a digital mobile device  1001  according to the invention in one of the action regions  60010   a ,  60010   b  illustrated in FIG. 60A and FIG. 60B.  
     [0281]FIG. 62 is a schematic view of interaction regions of an operating hand  62010  of a user  1050 . FIG. 62 is to be read in conjunction with FIGS.  59  to  61 . The ball of the hand, provided with the reference symbol S′, can be particularly advantageously used to activate operator controls in the side region S (lateral input means). The thumb, designated by the reference symbol V′, can particularly advantageously be used to activate operator controls in the front-side region (front-side input means). The other fingers apart from the thumb, which are designated by the reference symbol R″, can particularly advantageously be used to activate operator controls in the rear-side region (rear-side input means).  
     [0282]FIG. 63 shows, by reference to the illustration in FIG. 57, a schematic view of the action regions of the operating means in the action region within reach of the operator&#39;s holding hand for single-handed or two-handed input possibilities, and left-handed and/or right-handed operator control on a two-leaf digital mobile device  1001  according to the invention.  
     [0283]FIG. 63A shows a first operating mode of the mobile device  1001  in which two-handed operator control is carried out, operating means (not illustrated in more detail) being arranged both in the action region  54010   b  and in the action region  54040   b.    
     [0284]FIG. 63B shows a second operating mode of the mobile device  1001 , preferably for right-handed people, in which mode single-handed operation is carried out by means of the right hand, operating means (not illustrated in more detail) being arranged only in the action region  0 . 54010   b.    
     [0285]FIG. 63C shows a third operating mode of the mobile device  1001 , preferably for left-handed people, in which mode single-handed operation is carried out by means of the left hand, operating means (not illustrated in more detail) being arranged only in the action region  54040   b.    
     [0286]FIG. 64 shows a schematic view of exemplary operating means alternatives in the action region within reach of the operator&#39;s holding hand on a two-leaf digital mobile device  1001  according to the invention. The partial FIGS. 64A to  64 I show variants of ergonomically advantageous arrangements of operator controls which can be combined with one another and which do not necessarily all need to be implemented in a single exemplary embodiment of a mobile device  1001  according to the invention.  
     [0287]FIG. 64A shows a variant with a touch pad  64010  on the front side or on the reverse side in the main operator control part  1020  and with a separate main display part  1010 . Movements of a cursor  64020  triggered by activating the touch pad  64010  can be seen on the main display part  1010 .  
     [0288]FIG. 64B shows a variant of the situation illustrated in FIG. 64A, with a touch pad or touch screen  64010   a  on the main display part  1010 . In this case, a specific region  64010 A of the surface of the touch screen performs the function of a touch pad if the touch pad is implemented on the front side V. The implementation is alternatively effected on the reverse side R by means of a separate component. Movements of a cursor  64020  triggered by activation of the touch pad  64010  can be seen on the main display part  1010 .  
     [0289]FIG. 64D shows a variant with a tracker ball  64020  in the main display part  1010 . The tracker ball  64020  can preferably be implemented in the side region S or on the reverse side R. Movements of a cursor  64020  which are triggered by activating the tracker ball  64020  can be seen on the main display part  1010 .  
     [0290]FIG. 64E shows a variant with a tracker ball  64020  on the side S, in the front region V or at the rear R of the main input part  1020  with a separate main display part  1010 . Movements of a cursor  64020  which are triggered by activating the tracker ball  64020  can be seen on the main display part  1010 .  
     [0291]FIG. 64F shows a variant with a touch pad  64040  on the front side V, lateral side S or rear side R, arranged on the main input part  1020  in the action region  64030  within reach of the operator&#39;s holding hand, the mobile device  1001  being equipped with a separate main display part  1010 . The operating means  64050   a  to  64050   f  which are implemented by means of the touch pad  64040  act on the display in the main display part  1010  when activated by the user.  
     [0292]FIG. 64G shows a variant with a touch pad or touch screen region  64040  on the front side V, lateral side S or rear side R, provided on the main display part  1010 . The operating means  64050   a  to  64050   f  implemented by means of the touch pad  64040  act on the display in the main display part  1010  when activated by the user.  
     [0293]FIG. 64H shows a variant with momentary-contact switches  64060   a  to  64060   c  provided at the side S or at the rear R of the main display part  1010 . In one particularly preferred embodiment, the upper momentary-contact switch  64060 A is used to move up a marker displayed on the display, or to scroll backwards, the lower momentary-contact switch  64060 C is used to move down a marker displayed on the display, or to scroll forwards, and the central momentary-contact switch  64060 B is used to select an object chosen by means of the two other momentary-contact switches and displayed on the display.  
     [0294]FIG. 64I shows a variant of the arrangement illustrated in FIG. 64H, but with momentary-contact switches  64060   a  to  64060   c  provided on the main operator control part  1020 .  
     [0295]FIG. 65 shows a schematic view of operating means alternatives in the action region within reach of the operator&#39;s holding hand, relating to the interface selection, selection and activation of information on the display device  1010  on a two-leaf digital mobile device  1001  according to the invention.  
     [0296] The partial FIGS. 65A to  65 E show by way of example individual applications of the technical concepts of inventive mobile devices  1001  illustrated in FIGS.  55  to  64 . More details are also given in particular in the labelling information on the drawing. The preferred variants of the arrangement of the respective operating means in terms of their position at the front (V), at the side (S) or at the rear (R) are also respectively indicated next to the drawing.  
     [0297]FIG. 66 shows a schematic view of operating means in the action region of the operator&#39;s holding hand, relating to keyboard operation on the back, side and/or front with additional touch pad input means with different designs on a two-leaf digital mobile device  1001  according to the invention.  
     [0298] The partial FIGS. 66. 1  to  66 . 4  show by way of example individual applications of the technical concepts of inventive mobile devices  1001  illustrated in FIGS.  55  to  64 . More details can also be obtained in particular from the labelling information on the drawing. The preferred variants of the arrangement of the corresponding operating means relating to their position at the front (V), at the side (S) or at the rear (R) are respectively given next to the drawing.  
     [0299]FIG. 67 shows a perspective back view of a two-leaf digital mobile device  1001  according to the invention with combination keys  67010   a ,  67010   b  on the back of the hand-grip parts  67020   a ,  67020   b  for two-handed operation by the user  1050 , i.e. a set of combination keys  67010   a ,  67010   b  is arranged on the back of each leaf.  
     [0300]FIG. 68 is a schematic view of the use of the two-leaf digital mobile device  1001  according to the invention from FIG. 67 in the manner of a book held with both hands with combination keys  67010   a  on the back for single-handed operation by the user  1050 , i.e. the mobile device  1001  is held in both hands but operated with only one hand.  
     [0301]FIG. 69 is a schematic view of the use of the two-leaf digital mobile device  1001  according to the invention from FIG. 68 with another method of handling.  
     [0302]FIG. 70 shows a perspective view of a two-leaf digital mobile device  1001  according to the invention which is held with two hands with pressure-sensitive regions  70010   a ,  70010   b  which can be operated using a thumb.  
     [0303]FIG. 71 shows a perspective back view of a two-leaf digital mobile device  1001  according to the invention with function keys  71010  on the back, which keys  71010  lie in the region  71020  within reach of the operator&#39;s holding hand and can be activated by the holding hand.  71030 .  
     [0304]FIG. 72 shows a perspective view of a two-leaf digital mobile device  1001  according to the invention which is held with the left hand  72010  and operated in the region  72020  within reach of the operator&#39;s left holding hand  72010 , the right hand  72030  operating a pen  72040  which can be used to input information.  
     [0305]FIG. 73 shows a perspective view of a two-leaf digital mobile device  1001  according to the invention which is held by a hand in the hinge region, an operator control operation on a touch pad being carried out with the other hand.  
     [0306]FIG. 74 shows a schematic view of three operator controls which are arranged on the back of the mobile device  1001  according to the invention, and their assigned functionalities. The keys  64060   a ,  64060   b ,  64060   c  shown have been described in more detail above with respect to FIGS. 64, 65,  66  and  67 . Functional details on these keys are given in the drawing in FIG. 74.  
     [0307]FIG. 75 shows a perspective back view of a two-leaf digital mobile device  1001  according to the invention with a different embodiment of the holding-hand operating means, in particular removable back parts  75010  being provided. The possibility of replacing these back parts  75010  permits, for example, the mobile device  1001  according to the invention to be offered on the market with a fashionable casing with different colours, shapes, patterns and materials on the standard basic device so as to incur little extra expenditure.  
     [0308]FIG. 76 shows a perspective back view with an operator&#39;s hand  76010  arranged in the region within reach of the operator&#39;s hand on a digital mobile device  1001  according to the invention from FIG. 75 when an interface selection switch  76020  is pressed.  
     [0309]FIG. 77 shows various operating modes of the hand-grip part  77010  of the mobile device according to the invention from FIG. 75. The hand-grip part  77010  comprises, in particular, a gripping panel  77020  which is oriented from the hinge  1030  of the mobile part away towards the outer edge of the leaf, and an adjoining keypad block  77030  which is, however, oriented towards the hinge  1030  and preferably has three keys  77030 A,  77030 B,  77030 C which are arranged together. The functionality of the keys  77030 A,  77030 B and  77030 C has already been explained in FIGS.  64  to  67  in relation to the references  64060 A,  64060 B and  64060 C there. The following aspects are illustrated schematically on an individual basis:  
     [0310]FIG. 77 a : Hand-grip stabilization/protection: an expedient embodiment of the gripping panel  77020  with a particularly robust, easy-grip surface which is pleasant to the touch makes the mobile device  1001  easier to operate as the user  1050  can without difficulty leave the fingers of one hand on the gripping panel even for relatively long periods of time in order to be able to execute an operating action at short notice when necessary.  
     [0311]FIG. 77 b : Interface selection switch: an electric pushbutton switch (not illustrated) can be arranged underneath the gripping panel  77020  and is actuated when the gripping panel  77020  is pressed by the fingers of a hand of the user  1050 . As the fingers of this hand are already in the basic position on the gripping panel  77020 , it proves particularly advantageous to use the pushbutton switch which can be actuated by the gripping panel  77020  as an interface selection switch. The mobile device  1001  according to the invention is constructed in such a way that when the user  1050  is making normal use of the device, for example reading items presented on the display, the user is confronted as little as possible with operator control menus, operating icons and the like. However, if the user  1050  wishes to perform an operator control operation, it is necessary to trigger the display of operator control menus, icons and the like. The gripping panel switch can advantageously be used for this triggering operation.  
     [0312]FIG. 77 c : Touch pad/slide pad: the surface of the gripping panel  77020  can advantageously be provided with a touch pad or slide pad for inputting directional information.  
     [0313]FIG. 77 d : Multifunction keys: multifunction keys  77030   a ,  77030   b  and  77030   c  can advantageously be provided for scrolling upwards, selecting and scrolling downwards.  
     [0314]FIG. 78 shows a schematic view of two different operating modes of the hand-grip part  77010  from FIG. 77.  
     [0315] The depressed gripping panel  77020  is shown schematically in FIG. 78A.  
     [0316] The depressed key  77030   b , with the gripping panel  77020  also depressed, is shown schematically in FIG. 78B.  
     [0317]FIG. 79A shows a single-leaf digital mobile device  1001  according to the invention with hand-grip part. Please refer to the description relating to FIG. 110A.  
     [0318]FIG. 79B shows a two-leaf digital mobile device  1001  according to the invention with hand-grip part. Please refer to the description relating to FIG. 110B.  
     [0319]FIG. 80A shows a two-leaf digital mobile device  1001  according to the invention with a permanently integrated device back part. Please refer to the description relating to FIG. 11A.  
     [0320]FIG. 80B shows the illustration from FIG. 80A, but with an exchangeable device back part. Please refer to the description relating to FIG. 111B.  
     [0321]FIG. 80C shows the arrangement from FIG. 80A, but with an exchangeable hand-grip part. Please refer to the description relating to FIG. 111C.  
     [0322]FIG. 81 is a schematic view of a mobile device  1001  according to the invention with a synchronization device for the screen and operator control unit after left-handed/right-handed presetting.  
     [0323] Numerous settings relating to the operating modes of the mobile device  1001  depend on its orientation relative to the gravitational field of the Earth. In particular, the methods of use illustrated in FIG. 81 can be determined from the orientation of the leaves in the gravitational field:  
                                                       Type   First leaf   Second leaf                          Book-like use,   (approximately)   (approximately)           held in hands   upright in   upright in               vertical position   vertical position           Book in lying   (approximately)   (approximately)           position   flat   flat           Notebook   (approximately)   (approximately)               upright in   flat               horizontal               position                      
 
     [0324] It therefore proves particularly advantageous to provide at least one leaf, but better both leaves, of the mobile device with one gravity sensor each, which sensor detects the orientation of the respective leaf in the field of gravity. The output signals of the gravity sensor/gravity sensors are fed to the electronic controller (central processor unit, not illustrated) of the mobile device  1001  and can be detected for the automatic detection of operating modes.  
     [0325]FIG. 81 is a schematic view of a rectangular gravity sensor  81010  in various states of use of the mobile device. A rectangular gravity sensor  81010  comprises an enclosed cavity with an essentially square arrangement in which a tracker ball is enclosed. The rectangular gravity sensor  81010  is integrated into one leaf of a mobile device  1001  in such a way that each of the four corners of the gravity sensor points to one of the outer edges of the leaf. Depending on the orientation of the edges of the leaf in the gravitational field, the tracker ball will come to rest in one of the four corners. Each of the four corners is therefore equipped with a sensor which expediently detects whether or not the ball is in the respective corner. This can be done, for example, by visual means using a photoelectric barrier. It is also possible to fabricate the tracker ball from an electrically conductive material, for example from metal, and to detect its location at the corners by means of electrical contacts.  
     [0326]FIG. 81B shows an orientation of the mobile device  1001  in the gravitational field, in which orientation the tracker ball of the rectangular gravity sensor  81010 A is in the corner b. This orientation as a “Notebook” is advantageous both for right-handed and for left-handed people for writing functions as the leaf which is pointing downwards permits writing functions with a writing pen (not illustrated).  
     [0327]FIG. 81C shows an orientation of the mobile device  1001  in the gravitational field, in which orientation the tracker ball of the rectangular gravity sensor  81010 A is in the corner c. This orientation is advantageous for right-handed people for reading functions as the leaf which is arranged on the right permits reading material to be displayed on a display.  
     [0328]FIG. 82 shows a schematic view of the gravity switch  81010  of the synchronization mechanism from FIG. 81 with presetting of the device for left-handed/right-handed people. As is apparent from the description of FIG. 81, it is possible to perform an optimum assignment of functionalities to individual leaves of the mobile device  1001  according to the invention for right-handed or left-handed people if, firstly, the characteristic “left-handed” or “right-handed” and, secondly, the position of individual leaves in the gravitational field are known. It therefore proves advantageous, with a mobile device  1001  according to the invention, to be able to make a “left-handed” or “right-handed” configuration setting so that the control unit (not illustrated) of the mobile device  1001  can automatically perform the setting of the use mode in terms of the functional apportioning and implementation to the leaves from the “left-handed” or “right-handed” presetting (entered only once when starting to use the device) in conjunction with the relation of the device to the gravitational field. This automatic feature also includes, in particular, the function of always automatically presenting the user with display contents with an upright, readable configuration.  
     [0329]FIG. 83 shows a schematic view of a second embodiment of a gravity switch  83010  on a digital mobile device according to FIG. 81 for automatic synchronization or setting of the display device and of the operator controls. The semicircular gravity switch  83010  contains a semicircular tubular section in which a tracker ball can move freely in the gravitational field. The position of the tracker ball can be sensed by means of suitable sensors (not illustrated) and fed to the controller (not illustrated) of the mobile device  1001 . FIG. 83A shows a cross section through a leaf which functions as an operator control part and has an embedded semicircular gravity switch  83010 . FIG. 83B shows a front view of a leaf which functions as an operator control part and has an embedded semicircular gravity switch  83010 . FIG. 83A is a schematic view of a semicircular gravity switch  83010  which is embedded in a leaf, in two leaf positions relative to the gravitational field.  
     [0330]FIG. 84 shows the semicircular gravity switch  83010  from FIG. 83 at different angles of inclination.  
     [0331]FIG. 84A relates to the case of a mobile device  1001  which is resting flat on a level underlying surface.  
     [0332]FIG. 84B relates to the case of a mobile device  1001  which has been raised slightly from a level underlying surface with an attitude angle of approximately 10 degrees.  
     [0333]FIG. 84C relates to the case of a mobile device  1001  which is being held in the hands, or is resting on a lap, with an attitude angle of approximately 20 degrees.  
     [0334]FIG. 84D relates to the case of a mobile device  1001  which is being held at an attitude angle of approximately 30 degrees.  
     [0335]FIG. 84E relates to the case of a mobile device  1001  which is being held at a significantly steeper attitude angle of up to approximately 90 degrees.  
     [0336] So that incorrect triggering of the switching over of the operating mode which is triggered by the gravity switch, for example when the mobile device is moved suddenly by the user, is avoided, it is necessary to define filter criteria according to which the controller (not illustrated) of the mobile device  1001  performs discrimination as to whether the position of the mobile device  1001  in the gravitational field has changed permanently or whether there is only a brief disruption occurring:  
     [0337] a) definition of tolerance ranges of the measured angles, and  
     [0338] b) definition of time constants, i.e. minimum times to which a change in position of the mobile device in the gravitational field must persist in order to bring about automatic resetting of the operating mode.  
     [0339]FIG. 85 is a schematic view, based on a semicircular gravity switch  83010 , of an automatic setting according to FIG. 84 for right-handed people as a function of whether an application is selected in which it is necessary to make an input or in which reading in the manner of a book is to be performed. For this purpose, the mobile device  1001  according to the invention is configured in a configuration menu (not shown in more detail) for the “right-handed” operating state. If the right-handed user  1050  holds the mobile device  1001  in his hands with the writing sensor surface  85020  on the right, the display is automatically activated in such a way that the reading material presented there appears in the customary reading direction from top to bottom. If the right-handed user  1050  turns the mobile device  1010  “upside down”, through 180 degrees, this operation is detected by the semicircular gravity sensor  83010 . The reading material is firstly “upside down” on the display  85020  which is now on the right, and an icon symbolizing “ready to switch over” appears on the display. Only after a predetermined time, for example after 5 seconds, does the mobile device  1001  detect that the position of use has changed permanently, and it transforms the contents displayed on the display  85020  in such a way that they are now “the right way up” again. The mode of use has thus been switched over by the user  1050  from the “right-handed writing” into “right-handed book reading” mode by simply turning around the mobile device  1001  without his also having to cope with configuration menus and dialogues.  
     [0340]FIG. 86 shows details of the sequence illustrated in FIG. 85.  
     [0341]FIG. 87 shows a third embodiment of a gravity switch for a digital mobile device according to FIG. 81. FIG. 87 shows a bent-tube gravity switch  87010  as a modification of the semicircular gravity switch  83010  illustrated in FIGS.  83  to  86 . The bent-tube gravity switch comprises a bent tube  87010   a  in which a tracker ball  87010   b  can move. The tube  87010   a  is bent slightly approximately at its centre. This results in three positions at which the tracker ball can assume a (meta)stable position which is dependent on the orientation in the gravitational field, specifically the setting point A as a first end point of the tube  87010   a , setting point B at the bend in the tube  87010   a  and setting point C at the other (second) end point of the tube  87010   a . A sensor (not illustrated) which is capable of detecting the tracker ball  87010   b  is provided at each of the setting points A, B and C.  
     [0342]FIG. 88 shows a cross-sectional view of a two-leaf digital mobile device  1001  according to the invention with a gravity switch  87010  according to FIG. 87 when the operator control part provided with the gravity sensor  87010  is folded up.  
     [0343]FIG. 89 shows the gravity switch  87010  from FIG. 87 at various angles of inclination.  
     [0344] From FIG. 89A it is apparent that the tracker ball  87010   b  comes to rest at the setting point B when the leaf of the mobile device is resting flat on the table.  
     [0345] Even when there is a slight angle of inclination, the tracker ball  87010   b  firstly still remains at the setting point B; cf. FIG. 89B.  
     [0346] The tracker ball only moves suddenly to the setting point A when there is a relatively large angle of inclination, as is apparent from FIG. 89C. This event can be used to trigger a semi-automatic configuration routine in the controller (not illustrated) of the mobile device  1001 . For example, a selection menu which offers the item “Orient monitor”, which can be selected by touch screen activation, can be displayed. Alternatively, the triggering is carried out by activating a key. It is also possible to provide a voice-activated control, for example by means of a spoken command: “Orient monitor!”.  
     [0347]FIG. 90 shows a semi-automatic setting operation for a two-leaf digital mobile device  1001  according to the invention for a right-handed presetting with a bent-tube gravity switch  87010  according to FIG. 87.  
     [0348] In the situation illustrated in FIG. 90. 2 , the mobile device  1001  is resting flat on a level underlying surface, for example the surface of a table. The tracker ball  87010   b  is at the setting point B. The first leaf  9010  of the mobile device  1001  comes to rest on the right and can be used by the user  1050  for writing using a writing pen  90020 .  
     [0349]FIG. 90. 3  shows that the user has lifted off the mobile device  1001  illustrated in FIG. 90. 2  from the underlying surface and is now holding it with both hands in the manner of a book. The tracker ball  87010   b  is then at the setting point A. The first leaf  9010  of the mobile device  1001  is still on the right and can be operated by the user  1050  in the region  9030  within reach of the operator&#39;s hand.  
     [0350]FIG. 90. 4  shows a situation after the user has turned the mobile device  1001  “upside down” by means of a rotational movement. The tracker ball  87010   b  is then at the setting point C. The first leaf  9010  of the mobile device  1001  is now on the left and can be operated by the user  1050  in the region  9030  within reach of the operator&#39;s hand. The second leaf  90040  with the display is on the right; the displayed contents are however still “upside down” as the time constant after which a change in the state of the bent-tube gravity switch  87010  is detected as valid by the controller (not illustrated) of the mobile device  1001  has not yet expired. The assignment of the functionalities to the momentary-contact switches  90050  on the back is also still “upside down”.  
     [0351]FIG. 90. 6  shows the state, illustrated in FIG. 90. 4 , after the time constant has expired. The contents displayed on the display  90040  have the correct orientation for reading, and the assignment of the functionalities to the momentary-contact switches  90050  on the back is now no longer “upside down”; cf. FIG. 90. 5 .  
     [0352]FIG. 91 shows a schematic cross-sectional view of a gravity switch according to a fourth embodiment with a mechanical transmission of the switching force via a tracker ball. The captive ball gravity switch  91010  shown comprises in particular a straight tube  91020  with a tracker ball  91030  which can move in it. In order to reduce noise effects when the tracker ball  91030  rolls, the straight tube  91010  can be sealed off at both ends with noise-damping closures  91050   a ,  91050   b , for example made of rubber or rubber-like plastic. The tracker ball  91030  can also be fabricated from rubber or rubber-like plastic in order to reduce noise. A pushbutton-switch operator control  91040  is arranged above the tube  91020 . The pushbutton-switch operator control  91040  has a projection  91040   a ,  91040   b  in the region of each of the ends of the tube  91020 , which projection  91040   a ,  91040   b  engages through the corresponding opening of the tube casing into the interior of the tube  91020 . In the basic position, the pushbutton-switch operator control  91040  does not impede the free movement of the tracker ball  91030 . The pushbutton-switch operator control  91040  can be pressed in the direction of the tube  91020  by the user  1050  pressing a finger of a hand counter to the restoring force of a spring (not illustrated), so that the projections  91040   a ,  91040   b  are pressed into the interior of the tube  91020 . If the tracker ball  91030  is at one of the end setting points A or B when the pushbutton-switch operator control  91040  is activated, the force is transmitted by the user  1050  via the pushbutton-switch operator control  91040  to the tracker ball  91020  which, for its part, passes on this force to the wall of the tube lying opposite the respective projection  91040   a ,  91040   b . An electric momentary-contact switch  91060   a ,  91060   b  which is activated by the force is provided at this point.  
     [0353] The captive ball gravity sensor  91010  therefore supplies, by means of the momentary-contact switches  91060   a ,  91060   b , an output signal which indicates its position in the gravitational field only if the user  1050  applies a compressive force to the pushbutton-switch operator control  91040 . The advantage of this gravity switch is principally that it does not require any measures to guard against accidentally triggered position change signals. The user  1050  activates the pushbutton-switch operator control  91040  manually when he has changed the position of the mobile device  1001  and wishes to inform the control unit (not illustrated) of this.  
     [0354]FIG. 92 shows a two-leaf digital mobile device  1001  according to the invention with a gravity switch  91010  from FIG. 91 with various settings in the gravitational field.  
     [0355]FIG. 93 shows a gravity switch  91010  according to FIG. 91 in various operating states.  
     [0356]FIG. 93A shows the captive ball gravity switch  91010  in an inclined position in which the tracker ball  91030  comes to rest at the setting point A.  
     [0357]FIG. 93B shows the captive ball gravity switch  91010  from FIG. 93A when pressure is applied by the user  1050 .  
     [0358]FIG. 93C. 4   a  shows the captive ball gravity switch  91010  from FIG. 93A after pressure has been applied by the user  1050 . As a result of a latching device, the pushbutton-switch operator control  91040  remains depressed and the tracker ball  91030  continues to be secured.  
     [0359]FIG. 93C. 4   b  shows the captive ball gravity switch  91010  from FIG. 93A after pressure has been applied by the user  1050  once more. The pushbutton-switch operator control  91040  is released and the tracker ball  91030  can move freely again. The setting point A applies for the control of the mobile device  1001  up to the next activation of the pushbutton-switch operator control  91040 .  
     [0360]FIG. 94 shows a mechanical setting operation of a two-leaf digital mobile device  1001  according to the invention with a captive ball gravity switch  91010  according to FIG. 91, based on a left-handed configuration.  
     [0361] The captive ball gravity switch  91010  is arranged in the region  94010  within reach of the operator&#39;s holding hand, on a first leaf  94020  of the mobile device; see FIG. 94. 2 . The tracker ball is at the setting point A. After the mobile device has been “turned upside down” in FIG. 94. 3 , the tracker ball is still at the setting point A owing to the securing effect described in FIG. 93C. 4   a . Only after the pushbutton-switch operator control  91040  has been activated by the user  1050  is it possible for the tracker ball to move into the setting point B, and for the mobile device to go into the changed operating mode; see FIG. 94. 5 . FIG. 94. 6  illustrates how the left-handed user writes with a pressure pen on the leaf  94020  which is now on the left. The information already given above in relation to FIG. 90 applies correspondingly to the switching over of the display and the orientation of operating means.  
     [0362]FIG. 103 shows a schematic view of a two-leaf embodiment of a digital mobile device according to the invention with a turning mechanism for a functional part.  
     [0363]FIG. 104 shows, in the partial FIGS. 104 a  to  104   e , a rear view or external view of the housing for different variants of digital hand-held parts  4010   a  to  4010   d  according to the invention.  
     [0364] The illustrated digital hand-held parts  4010   a  to  4010   d  comprise at least one flat display unit (not illustrated) for displaying digital information and are intended to be held by the user with one hand or with both hands. In preferred embodiments, digital hand-held parts also have input means, for example input keys  4020 . When necessary, digital hand-held parts can also be embodied as fully functioning computers including power source, central processor unit, memory and further peripherals. Numerous desirable applications of digital communication in general and digital hand-held parts of the type described above in particular are possible only if a digital hand-held part can be held and operated by the user with little fatigue even over a relatively long time. In this context, in particular a low weight and pleasant haptics are of considerable importance. It therefore proves expedient to configure the housings of digital hand-held parts in a particular way.  
     [0365]FIG. 104 a  shows a rear view of a two-leaf digital hand-held part  4010   a  with a first leaf  4030   a  and a second leaf  4030   b , which can be folded open and shut with respect to the user in the manner of a book by means of a hinge part  4030   c . The left-hand or right-hand hand-grip region (shown by hatching) is implemented on the housing back by means of a first housing back surface region  4040   a ,  4040   b  which is embodied in the form of a lip, whereas the remaining housing back surface is illustrated without hatching, and forms a second housing back surface region  4050   a ,  4050   b . Operator control keys  4020  are arranged on the first housing back region. It proves expedient to configure the first housing back surface region  4040   a ,  4040   b  differently than the second housing back surface region  4050   a ,  4050   b  in terms of the material used. Housing back surface regions corresponding to the first housing back surface region  4040   a ,  4040   b  are designated below as “holding region”, whereas housing back surface regions corresponding to the second housing back surface region  4050   a ,  4050   b  are designated as “cover region”. Designs which differ from the lip shape are also possible; however, the lip shape shown is to be considered a preferred embodiment.  
     [0366]FIG. 104 b  shows a first variant of the housing back illustrated in FIG. 104 a  in which a single-leaf digital hand-held part  4010   b  is provided with a leaf  4030 . This leaf  4030  can be protected against dust and damage by a book-cover-like cover mask  4060  which can be folded shut. The leaf  4030  also has a holding region  4040  and a cover region  4050 . In contrast to FIG. 104 a , FIG. 104 b  does not exhibit any operator control keys on the back.  
     [0367]FIG. 104 c  shows a second variant of the housing back illustrated in FIG. 104 a  in which a two-leaf digital hand-held part  4010   c  is provided with two leaves  4030   a ,  4030   b , but without input keys  4020 .  
     [0368]FIG. 104 d  shows a third variant of the housing back illustrated in FIG. 104 a  in which a single-leaf digital hand-held part  4010   b  is provided with a leaf  4030 . This leaf  4030  can be protected against dirt and damage by a book-cover-like cover mask  4060  which can be folded shut. In FIG. 104 d  the cover mask  4060  is flexibly folded over towards the rear. The leaf  4030  also has a holding region  4040  and a cover region  4050 .  
     [0369]FIG. 104 e  shows the digital hand-held part from FIG. 104 c  in the folded-shut state.  
     [0370] A significant aspect when selecting materials for the holding region and the cover region is the durability and resistance to abrasion. For example, it may be desired in terms of design to cover the surface of the cover part with natural leather. However, embodying the surface in the holding region with natural leather would have the disadvantage that the surface would relatively quickly assume a worn and used appearance. The difference between the holding region and cover region permits a different material to be selected so that, for example, the holding region can be embodied as an ageing-resistant and wear-proof metal part if the cover part is embodied in natural leather. A holding region which is embodied in a particularly durable fashion in this way protects the cover region against premature wear.  
     [0371] A further important aspect is the compressibility of the material used. If the cover region is made compressible, for the sake of the haptics, by using, for example, polyurethane foam, inexpedient compressibility there owing to the presence of pushbutton keys in the holding region can be avoided by using a material which is less compressible, or virtually incompressible.  
     [0372] In addition, the different mechanical flexibility of a material can be a relevant factor. If, for example, the digital hand-held part uses a flexible display, for example on a polymer base, it may be desirable to make its housing flexible in its entirety. In order to control and limit the flexibility of the entire housing, for instance in order to define a predetermined bending line, it may be advantageous to implement the holding region and the cover region with materials with different degrees of flexibility (rigidity). One possibility would be, for example, to manufacture the cover region from a relatively flexible material with a low degree of rigidity, while the holding region is made from a less flexible material with a relatively high degree of rigidity.  
     [0373] A further important criterion for the configuration of the housing of the digital hand-held part according to the invention is to determine whether the holding region and/or the cover region are configured as separately exchangeable parts. For example, an exchangeable cover region may be advantageous if, for example for reasons of fashion, it is to be made possible for the user to change the surface design. Also, an exchangeable solution may be justified owing to the abrasion which the holding region causes on the cover region, fabricated from more sensitive materials, despite the abovementioned protection.  
     [0374]FIG. 105 shows a schematic plan view of the lower edge or upper edge of a development of a housing from FIG. 104 c , which provides an exchangeable, compressible cover region  4050   a ,  4050   b . Here, the holding region  4040   a ,  4040   b  is embodied essentially integrally with the front part of the housing, while the cover region  4050   a ,  4050   b  is embodied in the form of separate, removable cover shells. These cover shells  4050   a ,  4050   b  are secured under the holding region  4040   a ,  4040   b  by clamping and can easily be removed and exchanged by the user by means of a sideways movement (1.) and subsequent upwards movement (2.). The cover shells  4050   a ,  4050   b  are preferably provided on the upper side and lower side with a projecting spring which engages in a corresponding groove in the housing and forms protection against the ingress of dirt and moisture. The electronics  4060  are protected, for example, by means of a sealing compound or by means of some other protective coating (not illustrated) to such an extent that they are also not damaged when the cover shell is replaced in the proper way.  
     [0375]FIG. 106 shows a schematic view of a housing back part  4010  with an exchangeable holding region  4040 . The holding region  4040  is formed by an essentially U-shaped part which can be pushed onto the edge region (in the direction of the arrow) and also pulled off again.  
     [0376]FIG. 107 shows a schematic view of exchangeable components of a modular housing back part. In the upper part of the figure, cover shells  4080   a  to  4080   d  are shown which can be exchanged separately. In the lower part of the figure, combination parts  4085   a  to  4085   d , which can be exchanged and which embody both the holding region and the cover region, are illustrated as alternatives.  
     [0377]FIG. 108 shows, in the partial FIGS. 108 a  to  108   c , rear views of further variants of housings of digital hand-held parts according to the invention, specifically those which have only one leaf. FIG. 108 a  shows a housing back part with two holding regions  4040   a ,  4040   b  and a cover region  4050  as well as with operator controls  4020 . FIG. 108 b  shows another housing back part with two holding regions  4040   a ,  4040   b  and a cover region  4050 , but without operator controls. FIG. 108 c  shows a further housing back part with a holding region  4040  and a cover region  4050  without operator controls.  
     [0378]FIG. 109 is a schematic view of the process of changing specific back parts on modular housing backs. FIG. 109 a  shows the insertion of a cover shell  4050  in a downward direction from above, into the basic housing to which the holding regions  4040   a ,  4040   b  are permanently connected. In one development, the cover shell  4050  can have flat cut-outs  4050   g  which permit the holding regions  4040   a ,  4040   b  to engage. This procedure is particularly suitable for hand-held parts of the type illustrated in FIG. 108 b . FIG. 109 b  shows, as an alternative, the insertion of a cover shell  4050  in the sideways direction into the basic housing to which a single holding region  4040  is permanently connected. In one development, the cover shell  4050  can have a flat cut-out  4050   g  which permits the holding region  4040  to engage. This procedure is particularly suitable for hand-held parts of the type illustrated in FIG. 108 c . FIG. 109 c  shows, as an alternative, a cover shell  4050  which is permanently connected to the basic device and onto which two holding region parts  4040   a ,  4040   b  which each form a holding region can be fitted in a suitable way, for example by bonding, latching connections, screws etc. This procedure is particularly suitable for hand-held parts of the type illustrated in FIGS. 108 a ,  108   b.    
     [0379]FIG. 110 shows, in the partial FIGS. 110 a  and  110   b , schematic views of different function zones of a modular housing of a single-leaf or two-leaf digital hand-held part according to the invention.  
     [0380]FIG. 111 shows, in the partial FIGS. 111 a  to  111   c , various aspects of a developed, modular housing of a digital hand-held part according to the invention.  
     [0381]FIG. 111 a  shows a plan view of the housing back of a completely assembled, two-leaf digital hand-held part according to the invention with a first leaf part  4030   a  and a second leaf part  4030   b . On the side facing the user, each of the leaves can have a planar display (not illustrated); in one preferred variant, each of the two leaves has a display (not illustrated). The leaf parts  4030   a ,  4030   b  can be folded open and shut with respect to the user in the manner of a book by means of a hinge device  4030   c . A housing back part which is associated with the basic housing is designated by the reference symbols  4090   a ,  4090   b . In each case a removable book back part  4095   a ,  4095   b  can be plugged in under the housing back part  4090   a ,  4090   b  and attached. FIG. 111 b  shows a state in which both book back parts  4095   a ,  4095   b  are extended laterally. Each book back part  4095   a ,  4095   b  has, in the example illustrated, one hand-grip part  4097   a  or  4097   b , respectively, which can include operator controls  4020 . FIG. 111 c  shows a state in which the hand-grip part  4097   a  is extended laterally out of the book back part  4095   a . Of course, the electrical connection of operator controls  4020  is made disconnectable by means of suitable plug-in connector devices  4099 .  
     [0382] It is apparent that the degree of modularity of the housing design according to FIGS. 111 a  to  111   c  is variable. If necessary, the possibility of removing a book back part separately can also be dispensed with, as can the possibility of removing a hand-grip part separately.  
     [0383]FIG. 112 shows an illustration of a mobile device  1001  according to the invention with a modular hand-grip part  112010  inserted at the side/at the back.  
     [0384]FIG. 113 shows an illustration of a modular hand-grip part  112010  from FIG. 112. The modular hand-grip part  112010  has suitable electrical and mechanical plug-in and engagement devices (not illustrated in more detail) in order to bring about an electrical and mechanical connection to the host device. The modular hand-grip part  112010  can be fitted not only into the electronic mobile device  1001  but also, for example, onto personal digital assistants (PDAs), web tablets or e-book reading devices. The modular hand-grip part  112010  corresponds to the technical teaching illustrated in FIGS.  103  to  111   c . However, it is embodied as a standalone device which can be attached to other devices, for example by bonding with adhesive from a tube or adhesive film or by means of mechanical clamping devices, in order to be able to make the functionality of a hand-grip part at the side or at the back also available to devices which are not equipped with one at the factory. The data connection between the modular hand-grip part and the host device can also be made, for example, in a wire-free fashion by means of Bluetooth or IrDA or else by means of a cable connection, for example to a serial interface of the host device.  
     [0385]FIG. 114 shows the modular hand-grip part  112010  from FIG. 112 when it is fitted onto the back of a host device  114010 . FIG. 114 a  illustrates, for example, attachment from the side by means of plugging, bonding, etc. FIG. 114 b  illustrates plugging on from above, for example in the manner of a tongue and groove system. FIG. 115 shows, in the partial FIGS. 115 a  to  115   c , a data processing device according to the invention with a wearable computer  1010 .  
     [0386] The wearable computer  1010  has a wearable computer housing  1015  which is embodied so as to be flat, with rounded edges and slightly concavely arched so that it can easily be carried on the body, for example with a belt  1017 . Other shapes of the housing  1015  are also possible if the computer can easily be carried on the body. In particular, forms which enable the wearable computer  1010  to be sewn into or inserted into items of clothing are possible.  
     [0387] The wearable computer  1010  which is illustrated by way of example has a display  1020  as well as operator controls  1030   a ,  1030   b  and  1030   c  which are embodied, for example, as momentary-contact switches. An LED  1040  can also be provided as status display.  
     [0388] At a suitable point, the wearable computer  1010  which is illustrated by way of example has a receptacle device (not illustrated) for a card module  1050 .  
     [0389]FIG. 115 b  shows the securing of the wearable computer  1010  to a belt  1017  by means of a securing loop which is attached in a suitable way to the housing  1015 . FIG. 115 b  also shows a protection against dirt and sprayed water, by means of a protective cap  1070  which is fitted from above onto the housing  1015  of the wearable computer  1010 . Furthermore, FIG. 115 b  shows a two-leaf hand-held part  1080  in the manner of a digital book which can be folded open and shut in the manner of a book by means of a hinge device  1081  and is connected to the wearable computer  1010  by means of a cable  1082 , and which is held in the hand by the user  1084 . In one preferred embodiment, the two-leaf hand-held part  1080  can be provided with two displays  1086   a ,  1086   b  which each essentially form the inner sides of the two leaves. The hand-held part  1080  can be made particularly simple, thin and lightweight by virtue of the fact that essential parts of the electronics are transposed into the wearable computer  1010  which is carried on the body.  
     [0390]FIG. 115 c  shows a user  1084  who is carrying the wearable computer  1010  on a shoulder belt  1017  and at the same time is holding the hand-held part  1080  in his hand in a way which is suitable for operation and reading, the right hand activating operator controls arranged on the back.  
     [0391]FIG. 116 shows, in the partial FIGS. 116 a  to  116   c , variants of the data processing device illustrated in FIG. 115 as a one-piece embodiment with a display, the hand-held parts from FIGS. 116 a  and  116   b  being able to be embodied both with and without their own power supply (for example storage battery or dry battery).  
     [0392]FIG. 116 a  to FIG. 116 c  show a wearable computer  1010  which interacts with a single-leaf hand-held part  1080   a , different and combinable operator control possibilities being specified.  
     [0393]FIG. 116 a  symbolically shows operator controls  1090  which are arranged on the back of the hand-held part  1080   a  and which can be embodied, for example, in the form of three pushbutton keys  1090   a ,  1090   b  and  1090   c . Here, the keys  1090   a ,  1090   b ,  1090   c  are arranged in the region within reach of a holding hand  1084   a  of a user  1084 . In one particularly preferred embodiment, the keys can be operated individually, for example in order to trigger a “scroll upwards” function by means of key  1090   a , in order to trigger a “scroll downwards” function by means of key  1090   c , and in order to trigger a menu selection function by means of key  1090   b . In the particularly preferred embodiment, the keys  1090   a ,  1090   b  and  1090   c  can also be operated together, or in combination with other input means, for example a touch-sensitive screen (not illustrated) or a voice input device with a microphone, in order to trigger further functions, for example by means of simultaneous operation of two or three keys. The embodiment which is shown by way of example also shows a cable connection which supplies the hand-held part with power and which permits bidirectional data communication. It is left open as to whether the hand-held part has its own storage battery or dry battery or the like. In such a case, if appropriate, the power source can be charged indirectly via the wearable computer.  
     [0394]FIG. 116 b  shows a variant which permits, in addition to the cable  1082 , a wire-free data connection between the wearable computer  1010  and the hand-held part  1080   a . This wire-free data connection may be made in particular by means of a radio-frequency radio link, for example according to the “Bluetooth” standard, or by means of an infrared connection, for example according to the IrDA standard. For this purpose, the wearable computer  1010  has a transceiver device  1095   a  at a suitable point. The hand-held part  1080   a  also has, at a suitable point, a transceiver device  1095   b  which is selected so as to match the transceiver device  1095   a  of the wearable computer  1010 . Data communication between the hand-held part and/or the wearable computer and remote or external equipment or devices, for example, the Internet, other personal computers, printers etc., is also possible via a cableless LAN (Local Area Network) or WAN (Wide Area Network), while the communication between the hand-held part and wearable computer is carried out via cable  1082 .  
     [0395]FIG. 116 b  shows the operator control of the hand-held part  1080  by means of a pressure pen  1094  which is made to move on a pressure-sensitive area  1087  by a hand  1084   a  of a user  1084 .  
     [0396]FIG. 116 c  shows a refinement of the data processing device which is illustrated in FIGS. 116 a  and/or  116   b  and in which the cable  1082  has been dispensed with. While it is possible to provide the hand-held part  1080  or  1080   a  with power from a power source (not illustrated), for example a storage battery or a dry battery, which is arranged in the wearable computer  1010  in the embodiment variants in FIGS. 115 and 116 a  to  26   b  which are provided with a cable, the embodiment or type of use illustrated in FIG. 116 c  requires a separate power supply of the hand-held part  1080   a , for example by means of a storage battery arranged in the hand-held part  1080   a , which storage battery is preferably provided in the handle part, for reasons of centre of gravity and cumbersomeness.  
     [0397]FIG. 116 c  shows the operator control of the hand-held part  1080   a  by means of a finger  1084   b  of a hand  1084   a  of a user  1084  on a pressure-sensitive area  1087 .  
     [0398]FIGS. 116 d  and  116   e  show further variants of the embodiments illustrated in FIGS. 116 a  to  116   c , but with a two-leaf hand-held part  1080 , the storage battery or the dry battery in FIG. 116 e  being preferably accommodated in the region of the rotational joint (hinge) for reasons of centre of gravity and cumbersomeness.  
     [0399]FIG. 117 shows, in the partial FIGS. 117 a  to  117   c , a further variant of a data processing device according to the invention. Unless specified otherwise, the references indicated here correspond to the references used in FIGS. 115 and 116.  
     [0400] In particular, FIG. 117 shows an application of the data processing device in which the hand-held part  1080  is set up in the manner of a notebook, i.e. a first leaf part  1086   b  rests on a level surface, for example the surface of a table, while a second leaf part  1086   b  is positioned perpendicularly. The individual embodiment examples can be combined as desired (not illustrated) in terms of the operator control and the corresponding embodiment in a different design.  
     [0401] In FIG. 117 a , the inwardly pointing surface of the first leaf part  1086   b  is pressure-sensitive, and the user  1084  moves a pressure pen  1094  on it with his hand and in this way makes a data input.  
     [0402] In FIG. 117 b , the inwardly pointing surface of the first leaf part  1086   b  is provided with the functionality of an input keypad, and the user  1084  activates a data input with his hand  1084   a . The embodiment of the keypad as a virtual keypad, which is operated by means of a sensitive input area, or as a real keypad with keys to be activated mechanically, is left open.  
     [0403] In FIG. 117 c , the inwardly pointing surface of the first leaf part  1086   b  is equipped with the functionality of a touch pad, and the user  1084  activates a data input with a finger  1084   b  of his hand  1084   a . In the example, a cursor is illustrated, which is shown on the display area and which indicates the relative position of the finger movement on the second leaf part (leaf of a book) which is embodied as a touch pad.  
     [0404]FIG. 118 shows a view of a first variant of a data processing system according to the invention with a wearable computer  1010  and a hand-held part  1080 , which are connected to one another via a cable  1082  (FIG. 118 a ) or in a wire-free fashion (FIG. 118 b ). This first variant constitutes a particularly cost-effective solution in which the hand-held part  1080  can be used only together with the wearable computer  1010 . In the variant shown in FIG. 118 a , the cable  1082  not only permits data to be exchanged between the hand-held part  1080  and the wearable computer  1010 ; power can also be supplied to the hand-held part  1080  via the cable  1082  from a power source, for example a storage battery, arranged in the wearable computer  1010 . As a result, the hand-held part  1080  can be made particularly low in weight. On the other hand, when the wearable computer  1010  is carried on the body, the weight of the necessary power source does not necessarily adversely affect the operating comfort. If the cable  1082  is avoided, it is necessary, as shown in FIG. 118 b , to provide a wire-free data connection between the hand-held part  1080  and the wearable computer  1010 . It is also necessary to provide a power source (not illustrated) in the hand-held part  1080 .  
     [0405]FIG. 119 shows a highly schematic block circuit diagram of the first variant (illustrated in FIG. 118) of a data processing system according to the invention. In particular, the central system bus (EASI), the central processor unit (CPU) and the memory (ROM/RAM) are arranged in the wearable computer  1010 . The hand-held part  1080  has, in particular, at least one, in two-leaf designs preferably also two or more displays and input means, for example momentary-contact keys or pressure-sensitive or touch-sensitive areas (touch screen, slide pad etc.). In the variant illustrated in FIG. 118 b , a power source  2001  is optionally provided in the hand-held part  1080 . The electronic devices of the hand-held part  1080  and of the wearable computer  1010  are each provided with a coupling interface  2020   a  and  2020   b  which is suitably constructed and connected to the other circuit components in such a way that the wearable computer  1010  can be operated by means of the devices provided in the hand-held part  1080 . This includes also in particular the fact that data can be displayed on one or more displays of the hand-held part  1080  under the control of the central processor unit (CPU) of the wearable computer  1010 . In certain embodiments, the hand-held part  1080  and the wearable computer  1010  can contain further modules, in particular  
     [0406] a) at least one interface device  2030  for card modules, for example according to the PCMCIA standard;  
     [0407] b) at least one interface device  2040  for magnetic cards;  
     [0408] c) at least one interface device for Flash ROM modules;  
     [0409] d) at least one interface device for wire-free data communication, for example according to the Bluetooth standard (radio) or according to the IrDA standard (infrared data transmission);  
     [0410] e) at least one interface device for microphone and loudspeaker (sound card);  
     [0411] f) at least one interface card for removable storage media such as CD-ROMs, diskettes etc.; or  
     [0412] g) at least one hard disk drive.  
     [0413] The labels given in FIG. 119 on the modules illustrated in schematic form give indications of their type and/or purpose. In certain embodiments, it is also possible to connect a plurality of identical or different hand-held parts to the wearable computer.  
     [0414]FIG. 120 shows a view of a second variant of a data processing system according to the invention with a wearable computer  1010  and a hand-held part  1080 , it also being possible to use the hand-held part  1080  independently (FIG. 120 a ) or to connect it in a wire-free fashion and/or with a cable  1082  to a wearable computer  1010  (FIG. 120 b ). In contrast to the first variant illustrated in FIG. 118, in the variant illustrated in FIG. 120 the hand-held part  1080  and the wearable computer  1010  can in principle be used independently of one another as they are both embodied as completely functional computers. FIG. 120 a  shows in schematic form a use of the hand-held part  1080  as an autonomous digital book. FIG. 120 b  shows a coupled system composed of a hand-held part  1080  and wearable computer  1010 . The additional data processing capacity of the wearable computer  1010  now makes it possible to convert the hand-held part  1080  into a high-performance notebook computer without it being necessary to provide the required computer capacity in the hand-held part  1080  from the outset. It is therefore possible to provide a hand-held part  1080  which can be used autonomously, but is nevertheless cost-effective, said hand-held part  1080  being for example an “eBook” for reading information in the form of books, periodicals, newspapers and documents and/or an Internet tablet for “surfing” on the Internet and/or a PDA (Personal Digital Assistant) for reading and writing notes, for running an appointments diary etc., which, when necessary, can be upgraded to form a high-performance overall system by coupling it to the wearable computer  1010 . For example, the hand-held part contains just a browser or a different operating system from that of the wearable computer. The operating system can be switched over as a result of the coupling, automatically after the coupling or in response to an input, and/or it supplements or expands the active operating system on the hand-held part.  
     [0415]FIG. 121 shows a highly schematic block circuit diagram of the second variant (illustrated in FIG. 119) of a data processing system according to the invention. In principle, reference is made to the statements above relating to FIG. 119. However, in the illustration in FIG. 121 both the hand-held part  1080  and wearable computer  1010  each have a separate central processor unit (CPU) as well as memory (RAM/ROM) and system bus (EASI).  
     [0416] The labels given in FIG. 121 on the modules which are illustrated in schematic form provide information on the type and/or purpose.  
     [0417]FIG. 122 shows a view of a third variant of a data processing system according to the invention with a wearable expansion device  1010   a  and a hand-held part  1080 , the hand-held part  1080  being also capable of being used alone. In contrast to the system illustrated in FIG. 120, unlike the wearable computer  1010  there, the wearable expansion device  1010   a  is not a standalone computer but rather contains only additional peripherals and/or power sources  2050 . The peripherals provided in the wearable expansion device may include in particular:  
     [0418] a) disk drives/adapters  2060  for exchangeable media such as CD-ROMs, diskettes, card modules;  
     [0419] b) devices for wire-free data transmission, in particular GSM and/or Bluetooth subsystems.  
     [0420] The peripheral components which can be used in the wearable expansion device may each be permanently installed in it or else be capable of being attached to it in a modular fashion in the manner of a component as part of an upgrade or retrofit.  
     [0421]FIG. 123 shows a highly schematic block circuit diagram of the third variant illustrated in FIG. 122 of a data processing system according to the invention. In principle, reference is made to the statements above relating to FIGS. 119 and 121. In contrast, in the illustration in FIG. 123 only the hand-held part  1080 , but not the wearable expansion device  1010   a , has a separate central processor unit (CPU) as well as memory (RAM/ROM) and system bus (EASI).  
     [0422] The labels which are given in FIG. 123 on the modules which are illustrated in schematic form provide information on the type and/or purpose.  
     [0423]FIG. 124 shows a perspective view of a digital mobile device according to the invention with a display part and operating part and a separate attachment.  
     [0424]FIG. 125 shows a perspective view of the attachment from FIG. 124 with a carrying bag and belt loop for use as a “wearable” device.  
     [0425]FIG. 126 shows a perspective view of the attachment and of the operator control part and display part from FIG. 125.  
     [0426]FIG. 127 shows a digital mobile device in a different embodiment as a wearable computer  127010 , which can in particular be used as a multimedia player including Digital Rights Management System (DRMS). The mobile device  127010  may have a PCMCIA slot  127020  which can be used in particular for holding a smart card, for example for distribution and payment systems. It is then also possible to equip the mobile device  127010  with a mobile phone functionality, for example WAP, SMS, GSM, GRPS, UMTS. In addition, it is advantageous to provide customary functions of a personal digital assistant (PDA) such as appointment planning, notes etc. These functions can, if appropriate, be used individually or in combination. Further functionalities are also possible.  
     [0427] The reference symbol refers to a display and operator control unit  127030 . The display and operator control unit has a display  127040  which is used to display texts and graphics including videos of the applications running on the mobile device  127010 . The connection between the mobile device  127010  and the display and operator control unit  127030  can also be made by means of a cable (not illustrated), but it is preferable to have a cableless data communications link, for example by means of radio waves using, for example, the Bluetooth standard or by means of infrared data transmission using, for example, the IrDA standard. The display and operator control unit  127030  can advantageously also be provided with an audio subsystem, for example an earpiece/microphone combination  127050 . For purely hearing purposes, it is also possible to use, for example, a HiFi headset. In a different variant (not illustrated), the microphone can also be integrated into the display and operator control unit  127030 .  
     [0428] The display and operator control unit  127030  is preferably dimensioned in such a way that it can be comfortably held in the hand. If the display and operator control unit  127030  is embodied with a touch screen, the user can easily carry out input operations with the thumb of the hand which is holding the unit. Alternatively, it is also possible to provide operator control with an input pen (not illustrated).  
     [0429] In one development, the microphone/earpiece set  127050  has a switching device  127060  with which, for example, music playback can be switched off and an incoming telephone call can be fed in. After the end of the telephone call, renewed activation can cause the music playback to be fed in again.  
     [0430] The display and operator control unit  127030  can be equipped with its own processor. For this reason, in this variant, the playback software (“Player”) can run directly on the display and operator control unit  127030 . As a result, it is in particular possible for copyrighted data formats to be resolved only in the display and operator control unit  127030  and fed to the earpiece. The data stream between the mobile device  127010  and display and operator control unit  127030  can be encrypted, for example, by means of the SSL protocol. With such a configuration, the playback decoder (not illustrated) with the digital rights management system can be provided in the mobile device  127010  without a risk of unauthorized copying.  
     [0431] The mobile device  127010  can interact with other devices such as an e-book reader, PDA, web tablet, PC or beamer via an LAN data connection. The mobile device can interact with the Internet via a WAN connection, for example over an analogue telephone line, ISDN line or DSL.  
     [0432]FIG. 127B shows a side view of the mobile device  127010 . For pleasant carrying comfort when the mobile device is attached to a trouser belt (not illustrated), the housing has an ergonomic shape which has a depression  127070  on the side facing the belt. For reasons of cumbersomeness, storage batteries (not illustrated) are preferably arranged in the lower region of the housing. An embodiment in which the housing can turn by means of a coupling part (not illustrated) somewhat in relation to the belt so that it can always be oriented in the direction of gravity is particularly advantageous.  
     [0433] In a further developed embodiment, customary peripherals, for example printers etc., can be connected to the mobile device  127010 .  
     [0434]FIG. 128 shows the display and operator control unit  127040  from FIG. 127. In a particularly preferred further development, the display and operator control unit 127040 has on each of the upper and lower end sides  128010   a ,  128010   b  a plug-in and engagement device (not illustrated) by means of which a cover module  128020  can be pushed onto the display and operator control unit  127040 , secured and, if appropriate, electrical contact can also be made with it. In one specific embodiment, the cover module  128020  is equipped with a telephone keypad, has a viewing window for the display of the display and operator control unit  127040  and can have an earpiece and microphone (not illustrated)—if the microphone is not contained in the display and operator control unit  127040 . The cover module  128020  can be embodied with a wide range of, possibly fashionable, shapes and colours. The purpose is  
     [0435] a) that the user can make a telephone call in the same accustomed way as with a conventional mobile telephone, and  
     [0436] b) that a device which is originally configured as a playback device can subsequently easily be upgraded to form a mobile telephone.  
     [0437] The cover module  128020  can, depending on the left-handedness or right-handedness of the user, be plugged onto the display and operator control unit  127040  from above or below. The image on the display of the display and operator control unit  127040  is automatically appropriately oriented so that texts and images can always be read.  
     [0438] In a simplified embodiment, this feature can also be omitted. The position and number of the plug-in and engagement connections can vary according to the individual case.  
     [0439] The plug-in connection by means of the possibility of coupling with internal securing means in the same way as, for example, in vehicles (not illustrated) is particularly advantageous, the operator control and the sound input and output being carried out via the same interface as that of the cover module.  
     [0440] The advantage of the separate display and operator control unit  127040  is in particular the compact and very easily produced design. In mobile radio applications, the GSM or UMTS transmission antenna can be kept away from parts of the body such as the head which are considered to be particularly sensitive by attaching it to the mobile device  127010  which can, if appropriate, be positioned away from the body, for example on a table.  
     [0441]FIG. 129 shows the possibility of using the display and operator control unit  127040  from FIG. 127 for different devices and applications. The display and operator control unit  127040  can always be kept ready for use on the person or in the vicinity of the person and interact with numerous other electronic devices, for example house monitoring means, games consoles, television set, fixed line telephone, set top box, video recorder, multimedia player, mobile telephone or PDA, within the distance which can be spanned using Bluetooth, for example. Furthermore, FIG. 129 shows a fixed version  129010  of the streamer. The difference from the mobile device  127010  is that, for example, relatively large hard disk memory systems can readily be integrated. Furthermore, with the fixed version  129010  a fixed line connection possibility and a satellite communication connection possibility are provided, whereas with the mobile device preferably GSM, UMTS or a fixed line is used. In the fixed variant  129010 , an external audio output is provided as it is advantageous to disconnect the image and sound from one another by means of a digital rights management system. A further advantage of the display and operator control unit  127040  is that it is possible both to perform operator control on different devices and to receive audio channels without having to pass via the external output of the fixed device to which loudspeaker systems are customarily connected (“remote control with headset”).  
     [0442] A wide variety of applications, for example house monitoring, games consoles, television set, fixed line telephone, set top box, video recorder, multimedia player, mobile telephone or PDA, can also run on the fixed station  129010 .  
     [0443] The reference  129020  refers to the PCMCIA module which, in one embodiment, constitutes a digital rights management system (DRMS) with decoder function and can easily be connected and disconnected between the fixed station  129010  and the mobile device  127010 . In particular the functionalities  129030  can be supported by the DRMS.  
     [0444]FIG. 130 shows a schematic perspective view of a detachable two-leaf mobile device according to the invention with a coupling mechanism in the hinge and a coupling lock which is to be inserted, using the example of a storage battery.