Abstract:
A personal computer system split into a local portion and a remote portion. In one embodiment the remote portion of the split personal computer system is located in a remote location and normally maintained by a network service provider and has personal computer application programs stored thereon that are controlled by the individuals local portion. The remote portion provides one or more personal computer application programs as a service that can be selected by the individual and stores the individuals data after running the personal computer application program selected by the individual. Both the selected program and the individuals data can be accessed upon providing a valid password by the individual. The remote portion has a controller that can collect fees for the application program services provided each individual.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation of U.S. Ser. No. 10/050,624, filed Jan. 16, 2002, which is a continuation of U.S. Ser. No. 09/443,125, filed Nov. 18, 1999, now U.S. Pat. No. 6,360,253; which is a continuation of U.S. Ser. No. 09/014,859, filed Jan. 29, 1998, now U.S. Pat. No. 6,243,743. The entire content of U.S. Ser. Nos. 10/050,624, 09/443,125 and 09/014,859 is hereby incorporated herein by reference in its entirety. 
     
    
     
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    Not applicable.  
         BACKGROUND OF THE INVENTION  
         [0003]    Many people currently use several computers in the execution of their job duties. For example, an individual may have one computer located at work, another computer located in an office at home, and yet another computer which is portable to use when the individual is neither at work nor at home. The quickly changing technology in the computer area constantly requires consumers to upgrade their computer systems to meet their demands. This means that the individual must separately upgrade the software and hardware on each of the office computer, the home computer and the portable computer. To upgrade all three computers requires three separate software licenses and hardware items which are costly.  
           [0004]    Communications software for personal computers, such as pcAnywhere obtainable from Symantec Corporation are currently available. These communication software packages permit an individual to control a first computer from a second computer over phone lines.  
           [0005]    Large communication networks are currently in use for providing cable television and telephone services to remote locations, such as homes, offices and hotel rooms. In addition, another large network known as the “internet” is being used to permit remote computers to communicate with each other. Cable television companies have recently been interfacing the cable television networks to the telephone and internet networks to provide access to all three networks through the cable television connection provided in a large number of homes.  
           [0006]    The companies are working to bring simpler and lower cost internet access to hundreds of millions of households by combining low cost cable television desk top controls with the phone system and a keyboard. This combination of elements and new products will allow users to access the internet and perform interactive tasks such as: a) e-mail; b) database searches; and c) interactive games and advertising.  
           [0007]    Time share computer systems have been used for many years. With conventional time share systems, individuals could connect to a central computer from a so-called “dumb” terminal and purchase time on a shared computer system. The dumb terminal communicated with the shared computer system via either phone line or hard wire remote terminal lines. The time share systems have largely been replaced by a personal computer, or a local area network (LAN) system which connects a large number of personal computers together so that resources can be shared.  
           [0008]    However, these new systems and networks do not address the problems facing computer users which are: 1) fast obsolescence of personal computer models and operating systems; 2) increasing demand for more memory and speed; 3) constant upgrades of software programs; and 4) need for computer portability by more and more people. It is to such an improved split personal computer system that the present invention is directed. The system of the present invention can be implemented by utilizing a programming language called JAVA, which was developed by Sun Microsystems, Inc. The JAVA language is ideally suited to allow communication between the Graphical User Interface (GUI) requirements of a local portion of the split personal computer system and the remote portion of the split personal computer system. The remote portion of the split personal computer system can operate C++ language application programs.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention relates to a split personal computer system including a remote portion and at least one local portion which is disposed remotely from the remote portion. The remote portion of the split personal computer system is adapted to perform the heavy computational and storage portions of the personal computer tasks, and the local portion of the split personal computer system is adapted to solely perform the video and the input/output portions of the personal computer tasks so that an individual manipulating the local portion of the split personal computer system is provided with the illusion of utilizing a complete personal computer system.  
           [0010]    The remote portion of the split personal computer system includes at least one remote computer unit.  
           [0011]    In one embodiment of the present invention, the local portion of the split personal computer system includes a television display unit, a television accessory unit in communication with the television display unit, and an input unit located in close proximity to the television display unit and in communication with the television accessory unit to input data signals into the television accessory unit. The television display unit selectively displays television signals output by the television accessory unit in a format perceivable by an individual located near the television display unit.  
           [0012]    The system is also provided with a communication means for interfacing the television accessory unit of the local portion of the split personal computer system with the remote computer unit of the remote portion of the split personal computer system for permitting data signals received by the television accessory unit from the input unit to be transmittable from the television accessory unit to the remote computer unit. The received data signals are processable by the remote computer unit to generate output signals. The output signals are transmittable from the remote computer unit to the television accessory unit, and then transmittable from the television accessory unit to the television display unit as television signals whereby the input unit is capable of functioning as an input unit for the remote computer unit and the television display unit is capable of functioning as a monitor for the remote computer unit to provide the illusion of a complete computer system from the point of view of the individual located adjacent the television display unit.  
           [0013]    One advantage of the present invention is that it permits the individual to operate the remote portion of the split personal computer system, for example, utilizing only the television display unit, the television accessory unit and the input unit. Because television display units are already provided in a large number of locations, such as homes and hotel rooms, the individual need only obtain the television accessory unit and the input unit to remotely operate the remote portion of the split personal computer system.  
           [0014]    In one embodiment of the present invention, the remote portion of the split personal computer system communicates with the television accessory unit of the local portion of the split personal computer system over an internet network. The internet network can be interfaced with a cable television network so that internet access is provided from the cable television connection currently provided in homes, hotels and businesses. The television accessory unit can be included in a cable television interface box interconnecting the television display unit to the cable television connection.  
           [0015]    In yet a further embodiment of the present invention, the television accessory unit can be provided in a portable housing. The advantage of the portable housing is that the individual can transport the television accessory unit from one location to another location to remotely operate the remote portion of the split personal computer system with different television display units.  
           [0016]    In yet another embodiment of the present invention, the remote computer unit of the remote portion of the split personal computer system can be provided as a plurality of networked computers which are controlled by a remote system controller. In this embodiment, a plurality of local portions of the split personal computer system are contemplated with each of the local portions of the split personal computer system being disposed remotely from the remote portion of the split personal computer system, and remotely from the other local portions of the split personal computer system. For example, each of the local portions of the split personal computer system could be provided in an individual&#39;s home or hotel room or any other location commonly including or adapted to receive a television display unit. The remote system controller can be provided with a billing program which counts the number of minutes that respective local portions of the split personal computer system are operating at least one of the networked computers of the remote portion of the split personal computer system. By employing the remote system controller and the billing program, individuals can “rent” computer time from the remote portion of the split personal computer system and obtain the benefits of a centralized management team upgrading the application software and the hardware on the remote portion of the split personal computer system.  
           [0017]    Other objects, features and advantages of the present invention are apparent from the following detailed description when read in conjunction with the attached drawings and appended claims. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0018]    [0018]FIG. 1 is a schematic, diagrammatic view of a split personal computer system constructed in accordance with the present invention which includes a local portion of the split personal computer system communicating with a remote portion of the split personal computer system.  
         [0019]    [0019]FIG. 2 is a schematic, diagrammatic view of one preferred embodiment of the local portion of the split personal computer system in which a television display unit is used as a monitor and a television accessory unit is provided to communicate with the remote portion of the split personal computer system and the television display unit.  
         [0020]    [0020]FIG. 3 is a schematic, diagrammatic view of the remote portion of the split personal computer system.  
         [0021]    [0021]FIG. 4 is a front elevational view of the television accessory unit disposed on the television display unit. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]    The terms “internet” and/or “communication link”, as used herein, refer to any suitable communication link which permits electronic communications, such as extra computer communication systems, intra computer communication systems, internal buses, local area networks, wide area networks, point to point shared and dedicated communications, infra red links, microwave links, telephone links, cable TV links, satellite links, radio links, fiber optic links, cable links and/or any other suitable communication system. It should be understood that each of the communication links are shown and described separately herein for the sole purpose of clearly illustrating the information being communicated between the various components. The communication links may not be separate communication links but may be a single physical communication link.  
         [0023]    Referring now to the drawings and more particularly to FIG. 1, shown therein and designated by the general reference numeral  10  is one embodiment of a split personal computer system constructed in accordance with the present invention. The split personal computer system  10  includes a plurality of local portions  12  disposed remotely with respect to each other. Only two local portions  12  of the split personal computer system  10  are shown and designated by the general reference numerals  12   a  and  12   b  in FIG. 1 for purposes of clarity. The local portions  12   a  and  12   b  of the split personal computer system  10  can be located in homes, hotel rooms, or any other suitable location and can be adapted to solely perform the video and the input/output portions of the personal computer tasks so that an individual manipulating one of the local portions  12  of the split personal computer system  10  is provided with the illusion of utilizing a complete personal computer system.  
         [0024]    The local portions  12   a  and  12   b  of the split personal computer system  10  communicate with a telephone network controller  14  via respective communication links  16   a  and  16   b , and a television network controller  18  via respective communication links  20   a  and  20   b . The telephone network controller  14  can be any type of bidirectional communication system, such as a direct phone line using a 1-800 line or the internet. The television network controller  18  can be any type of high-bandwidth communication system which permits at least unidirectional communications and possibly bi-directional communications. For example, the telephone network controller  14  and the television network controller  18  can be switches owned by the telephone and cable television companies, respectively, located in the same or different regions as the local portions  12   a  and  12   b  of the split personal computer system  10 .  
         [0025]    The split personal computer system  10  also includes at least one remote portion  22  disposed remotely with respect to the local portions  12   a  and  12   b  of the split personal computer system  10 . In essence, the remote portion  22  of the split personal computer system  10  is adapted to perform the heavy computational and storage functions of the personal computer tasks of the split personal computer system  10 . The remote portion  22  of the split personal computer system  10  is provided with a plurality of remote computer units  24  networked and controlled by a remote system controller  26 . Only two of the remote computer units are shown in FIG. 1 and designated by the reference numerals  24   a  and  24   b  for purposes of clarity. The remote computer units  24   a  and  24   b  can be any suitable computers which are capable of communicating with another computer located remotely with respect to such remote computer units  24   a  and  24   b . The remote computer units  24  can be located at an individual&#39;s office, home, or any other suitable location. Application programs are typically stored on the remote computer units  24  and the data associated with previous usage by the individual are stored on the remote computer units  24  so that such application programs and data are accessible by the local portion  12   a  and  12   b  of the split personal computer system  10 , as will be discussed below.  
         [0026]    The remote system controller  26  communicates with the telephone network controller  14  and the television network controller  18  via respective communication links  27   a  and  27   b  and also communicates with the remote computer units  24   a  and  24   b  via respective communication links  28   a  and  28   b . The remote system controller  26  can be any type of computer or controller which is capable of receiving signals transmitted from at least one local portion  12  of the split personal computer system  10  and supplying such signals to at least one of the remote computer units  24  to permit bidirectional communication therebetween.  
         [0027]    For example, the remote system controller  26  can be a network control computer which stores a list of access codes for individuals authorized to use the remote computer units  24 . The remote system controller  26  can also include a billing program which counts the time periods in which an individual utilizes at least one of the remote computer units  24  so that either session billings (in the case of hotel rooms billings, for example) or monthly billings could be made. The time periods can be measured in seconds, minutes or any other suitable unit of time.  
         [0028]    The local portions  12   a  and  12   b  of the split personal computer system  10  are substantially identical in construction and function. Thus, only the local portion  12   a  of the split personal computer system  10  will be described herein in detail for purposes of clarity.  
         [0029]    As shown in FIG. 2, the local portion  12   a  of the split personal computer system  10  is provided with a television display unit  30 , a television accessory unit  32  (shown in dashed lines), an input unit  34 , an output unit  36  and a telephone  38 .  
         [0030]    The television display unit  30  can be any suitable television set or other display device, such as a computer monitor which is capable of receiving television or other video signals from the television accessory unit  32  via a communication link  40  and outputting signals in a format perceivable by an individual located adjacent the television set. The term “television signals” as used herein can mean signals adapted to be displayed by a television set, or any other type of suitable video and/or audio signals.  
         [0031]    The input unit  34  can be a mouse, a keyboard, a scanner, a video wand, a remote control or any other suitable input unit. The input unit  34  is located adjacent the television display unit  30  and in communication with the television accessory unit  32  via a communication link  42  to input data signals into the television accessory unit  32 .  
         [0032]    The output unit  36  receives data signals from the television accessory unit  32  via a communication link  44  to provide an output signal in hardcopy or other tangible or intangible formats. The output unit  36  can be any type of output unit capable of receiving signals from the television accessory unit  32 , such as a printer, a plotter, a local hard drive or a floppy disk.  
         [0033]    The telephone  38  bidirectionally communicates with the television accessory unit  32  via a communication link  46 . The telephone  38  can be any type of telephone or other suitable bidirectional communication system.  
         [0034]    The television accessory unit  32  includes a television interface  50 , a local computer  52  and a signal separator interface  54 . Each of the television interface  50 , local computer  52  and signal separator interface  54  can be located within a single portable housing  55  (FIG. 4) which is adapted to be disposed adjacent the television display unit  30 , or can be provided as components included in the television display unit  30 . The advantage of the portable housing  55  is that the individual can transport the television accessory unit  32  from one location to another location to remotely operate the remote portion  22  of the split personal computer system  10  with different television display units  30 .  
         [0035]    The local computer  52  can be any type of suitable computer and desirably includes temporary and permanent storage devices, and an operating system loaded thereon. The operating system can include the display and input/output portions of Windows 95, Windows 3.1, Macintosh, OS/2, NT95 or any other suitable operating system.  
         [0036]    The signal separator interface  54  communicates with the telephone network controller  14  and the television network controller  18  via the communication links  16   a  and  20   a . The signal separator interface  54  serves to route signals received thereby to the proper entity to process such signals. For example, two types of television signals can be received from the television network controller  18 : those originally transmitted by the remote portion  22  of the split personal computer system  10  and those originally transmitted by a television station block  57  (FIG. 1). The signals originally transmitted by the remote portion  22  of the split personal computer system  10  are forwarded by the signal separator interface  54  to the local computer  52 , and the signals originally transmitted by the television station block  57  are forwarded by the signal separator interface  54  to the television interface  50 . The television station block  57  can be any television station which transmits audio and/or video signals which can be displayed or otherwise output by the television display unit  30 . A header or other identifier can be included in the signals originally transmitted by the remote portion  22  of the split personal computer system  10  so that the signal separator interface  54  can distinguish between the signals originating from the remote portion  22  of the split personal computer system  10  and the television station block  57 .  
         [0037]    In addition, at least two types of signals can be received by the signal separator interface  54  from the telephone network controller  14 : those originating from the remote portion  22  of the split personal computer system  10  and those not originating from the remote portion  22  of the split personal computer system  10 . Those signals received by the signal separator interface  54  from the communication link  16   a  which are originated from the remote portion  22  of the split personal computer system  10  are transmitted to the local computer  52 , and those signals which do not originate from the remote portion  22  of the split personal computer system  10  are transmitted to the telephone  38  via the communication link  46 , for a purpose to be described hereinafter. A header or other identifier can be included in the signals originally transmitted by the remote portion  22  of the split personal computer system  10  so that the signal separator interface can distinguish between the signals originating from the remote portion  22  of the split personal computer system  10  and those not originating from the remote portion  22  of the split personal computer system  10 .  
         [0038]    The input unit  34  provides signals to the signal separator interface  54  over the communication link  42 . Included in the signals provided to the signal separator interface  54 , are three different categories of signals. The input unit  34  may include a header or other identifier in the signals it provides to the signal separator interface  54  so that the signal separator interface  54  can distinguish between the three different categories of signals.  
         [0039]    The first category of signals are those which control the television display unit  30 . Upon receipt of a signal in the first category, the signal separator interface  44  forwards such signals to the television interface  50  via a communication link  56 . The television interface  50  then forwards such first category signals to the television display unit  30  so that the television display unit  30  will receive such first category signals and respond accordingly. First category signals include those signals which change the channel or volume of the television display unit  30 , for example. Before the television accessory unit  32  can be utilized to access the remote portion  22  of the split personal computer system  10 , an individual located adjacent the television display unit  20  operates the input unit  34  to tune the television display unit  20  to a suitable channel to receive television signals from the television accessory unit  32  via a communication link  40  so that the television display unit  30  selectively displays television signals output by the television accessory unit  32  in a format perceivable by at least one individual located adjacent the television display unit  30 .  
         [0040]    The second category of signals transmitted from the input unit  34  to the signal separator interface  54  are those signals intended to control or operate the local computer  52 . Upon receipt of a second category signal, the signal separator interface  54  outputs such second category signal to the local computer  52  via a communication link  58 . The second category signals can be the normal computer control signals plus a special remote logon command that can either be a set of keyboard strokes or a special function key provided on the input unit  34  for this purpose. Upon receipt of the remote logon command, the operating system software of the local computer  52  outputs signals to the television interface  50  which formats such signals as television signals. The television interface  50  then transmits the television signals to the television display unit  30  to cause the screen (or at least some portion thereof) of the television display unit  30  to appear as a normal personal computer screen selected by the individual (e.g. Windows 95, Windows 3.1, Macintosh, OS/2, NT95 or any other common PC screen used by the individual).  
         [0041]    In addition, the receipt of the remote logon command causes the operating system software of the local computer  52  to output the remote logon command to the telephone network controller  14  via the communication links  58  and  16   a . The telephone network controller  14  transmits the remote logon command to the remote system controller  26  via the communication link  27   a . The remote system controller  26  receives the remote logon command, and in response thereto, the remote system controller  26  checks the remote logon command for validity and allows connection to at least one of the remote computer units  24  if the remote logon command is valid and prohibits connection of the remote portion  22  to the local portion  12  of the split personal computer system  10  if the particular remote logon command is not valid. The validity of the remote logon command can be determined in a manner recited in U.S. Pat. No. 4,528,643, issued to Charles C. Freeny on Jul. 9, 1985, which disclosure is hereby incorporated herein by reference.  
         [0042]    Once the local portion  12  of the split personal computer system  10  and the remote portion  22  of the split personal computer system  10  are connected to permit communication therebetween, the remote portion  22  of the split personal computer system  10  provides video signals to the local portion  12  of the split personal computer system  10  via the sequential communication links  27   b  and  20   a , and data signals to the local portion  12  of the split personal computer system  10  via the sequential communication links  27   a  and  16   a . The video and data signals transmitted from the remote portion  22  of the split personal computer system  10  are received by the signal separator interface  54  and then forwarded to the local computer  52  via the communication link  58 . The local computer  52  receives the video and data signals, and then the operating system of the local computer  52  transmits the video and data signals to the television interface  50  via a communication link  60 . The television interface  50  then formats the video and data signals into audio television signals, video television signals or audio and video television signals. The television signals are then transmitted to the television display unit  30  so that the television signals are perceivable by the individual located adjacent the television display unit  30 .  
         [0043]    The third category of signals provided from the input unit  34  to the signal separator interface  54  can be those associated with mouse signals (point and click signals) or keyboard typing signals or any other suitable data input signals. The third category of signals are transmitted from the signal separator interface  54  to at least one of the remote computer units  24  via the sequential communication links  16   a ,  27   a  and  28   a . The remote computer unit  24   a  receives such transmitted signals and processes same with at least one of the application computer programs to generate output signals including video and data signals. The video signals are transmitted from the remote computer unit  24   a  to the signal separator interface  54  of the television accessory unit  32  via the sequential communication links  28   a ,  27   b  and  20   a . The data signals are transmitted from the remote computer unit  24   a  to the signal separator interface  54  of the television accessory unit  32  via the sequential communication links  28   a ,  27   a  and  16   a.    
         [0044]    The signal separator interface  54  receives the video and data signals and in response thereto, the signal separator interface  54  transmits such video and data signals to the local computer  52  via the communication link  58 . The local computer  52  receives the video and data signals and transmits at least some of such video and data signals to the television display unit  30  via the television interface  50  to update the screen. Some of the data signals received by the local computer  52  can be directed to the output unit  36  to provide tangible and/or intangible output of the data signals.  
         [0045]    The above stated process is then repeated a plurality of times so that the local and remote portions  12  and  22  of the split personal computer system  10  cooperate to provide the illusion of a single complete personal computer system to the individual located at the local portion  12  of the split personal computer system  10 . That is, the remote portion  22  of the split personal computer system  10  provides the individual utilizing the local portion  12  of the split personal computer system  10  with access to the application software packages stored on the remote portion  22  of the split personal computer system  10 , and data stored on the remote portion  22  of the split personal computer system  10  on behalf of the individual in conjunction with previous usage. The local portion  12  of the split personal computer system  10  provides the individual with visual feedback via the television display unit  30 , and input and output capabilities via the input unit  34  and the output unit  36 .  
         [0046]    Shown in FIG. 3 is a schematic diagram of the remote portion  22  of the split personal computer system  10 . The remote computer units  24  are substantially identical in construction and function. Thus, only the remote computer unit  24   a  will be described herein for purposes of clarity. However, like components on the remote computer units  24   a  and  24   b  will be designated with the same numeral, but different alphabetic suffixes “a” and “b”, respectively.  
         [0047]    The remote computer unit  24   a  is provided with a permanent memory  70   a , a central processing unit  72   a  and a random access memory (RAM)  74   a . The central processing unit  72   a  can communicate with the permanent memory  70   a  and the random access memory  74   a  via communication links  76   a  and  78   a  in a manner well known in the art. The remote computer units  24  can be provided with operating system software stored either on the permanent memory  70  or the random access memory  74  to permit more than one individual to simultaneously utilize or share each of the permanent memory  70 , central processing unit  72 , and/or random access memory  74  on the remote computer units  24  to conserve resources. The remote computer units  24  can be loaded with any or all of the application software currently available, such as WordPerfect®, Lotus 1,2,3®, Excel®, MS Word® and Access® brand software, for example.  
         [0048]    Although more than one local portion  12  of the split personal computer system  10  can communicate with the remote portion  22  of the split personal computer system  10  simultaneously, the probability that all of the local portions  12  of the split personal computer system  10  will utilize the remote portion  22  of the split personal computer system  10  simultaneously is slim. To further conserve resources, the remote portion  22  of the split personal computer system  10  desirably has less remote computer units  24  than the number of local portions  12  of the split personal computer system  10  which have access thereto.  
         [0049]    In one embodiment, a method for utilizing the split personal computer system  10  includes the step of inputting respective data signals into at least two of the television accessory units  32  of the local portions  12  of the split personal computer system  10 . The television accessory units  32 , then output the respective data signals to the remote portion  22  of the split personal computer system  10  via respective communication links  16   a  and  16   b , the telephone network controller  14  and the communication link  27   a . The remote portion  22  of the split personal computer system  10  receives the respective data signals. The respective data signals are then forwarded to at least one of the remote computer units  24  which then processes the respective data signals with at least one application program to generate output signals.  
         [0050]    The output signals are then output by the remote portion  22  of the split personal computer system  10  to the television accessory units  32  via the communication link  27   b , the television network controller  18 , and the communication links  20   a  and  20   b  such that output signals are received by the television accessory unit  32  which correspond to the data signals input to that respective television accessory unit  32 . Each television accessory unit  32  outputs the respective output signals received from the remote portion  22  of the split personal computer system  10  to the television display unit  30  as television signals. And, each television display unit  30  receives the television signals output by the respective television accessory units  32  and then outputs the television signals in a format perceivable by at least one individual located near the television display unit  30 .  
         [0051]    Although only one cycle of the method is described herein, it should be understood that such method can be repeated any number of times so that respective individuals are simultaneously provided with the illusion of operating a complete personal computer system.  
         [0052]    Shown in FIG. 4 is the television accessory unit  32  disposed on top of the television display unit  30 . As shown, the television accessory unit  32  having the portable housing  55  can be in the form of a cable television interface box interconnecting the television display unit  30  to a cable television connection  80 . The cable television connection  80  is desirably interfaced with both the telephone network controller  14  and the television network controller  18  so that telephone, internet and television access, for example, is provided from the cable television connection  80  currently provided in suitable locations such as homes, hotels and businesses.  
         [0053]    Although the present invention has been shown and described herein as operating with the television display unit  30 , it should be understood that the present invention should not be limited to including, the television display unit  30 . For example, a monitor or other type of output unit can be utilized in place of the television display unit  30 .  
         [0054]    Changes may be made in the construction and the operation of the various components, elements and assemblies described herein and changes may be made in the steps or the sequence of steps of the methods described herein without departing from the spirit and scope of the invention as defined in the following claims.