Patent Publication Number: US-2011075186-A1

Title: Image processing apparatus, method performed by image processing apparatus, program product, and recording medium therefor

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2009-226914 filed in Japan on Sep. 30, 2009. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to image processing apparatuses and, more particularly, to an image processing apparatus that has a wireless communication function, a method performed by the image processing apparatus, a program product, and a recording medium therefore. 
     2. Description of the Related Art 
     In recent years, wireless local area network (LAN) communication, in which data communication is available even when devices are not physically connected to a network, has been rapidly and widely becoming used. Wireless LAN communication includes various communication modes; typical examples thereof are the infrastructure mode and the ad hoc mode, which is the operation mode of the wireless LAN communication that conforms to the IEEE 802.11 standard. The infrastructure mode wireless LAN communication is a mode in which data communication is performed via access points, whereas, the ad hoc mode is a mode in which data communication is directly performed between devices without using access points. 
     Japanese Patent Application Laid-open No. 2005-64552 discloses, as a printer that uses the above described wireless LAN communication, a printing apparatus that includes two wireless communication units. The first wireless communication unit directly performs wireless communication with terminal devices in the ad hoc mode. The second wireless communication unit performs, in the infrastructure mode, wireless communication with wireless communication devices other than the terminal devices. Because this printing apparatus is configured such that wireless communication is directly performed with the terminal devices in the ad hoc mode and that the terminal devices are not connected to a wireless communication network, a user of the terminal device cannot access, for example, other terminal devices or servers via the wireless communication network. This makes it possible to prevent the leakage of confidential information contained in the other terminal devices or the servers that are connected to the network, thus ensuring the security. 
     However, with the printing apparatus disclosed in Japanese Patent Application Laid-open No. 2005-64552, the security of communication data is not ensured when a connection is established in the ad hoc mode. Accordingly, a third party can illegally intercept communication data and also easily obtain communication data that is stored in the connected printing apparatus. Furthermore, there is a problem in that the printing apparatus has a lack of versatility because only wireless LAN communication is used in the wireless communication system when the printing apparatus communicates with the terminal device; in that the printing apparatus cannot perform data communication with communication devices using other wireless communication systems; and in that various settings cannot be set for the wireless communication. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to at least partially solve the problems in the conventional technology. 
     According to an aspect of the present invention, there is provided an image processing apparatus that can perform wireless communication, the image processing apparatus including a sub communication unit that receives an association process request using wireless communication and performs an association process; and a main communication unit that performs wireless communication in accordance with association information that is used in the association process and setup information that is setting information on wireless communication that can be set for each system of the association process request. 
     According to another aspect of the present invention, there is provided a method performed by an image processing apparatus that can perform wireless communication, the method including performing an association process by receiving an association process request using wireless communication; and performing wireless communication in accordance with association information that is used in the association process and setup information that is setting information on wireless communication that can be set for each system of the association process request. 
     According to another aspect of the present invention, there is a computer program product comprising a computer usable medium having computer readable program codes embodied in the medium that when executed causes a computer to execute, performing an association process by receiving an association process request using wireless communication; and performing wireless communication in accordance with association information that is used in the association process and setup information that is setting information on wireless communication that can be set for each system of the association process request. 
     The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram illustrating a communication system  100  according to an embodiment; 
         FIG. 2  is a functional block diagram illustrating an image processing apparatus  130  according to the embodiment; 
         FIG. 3  is a flowchart illustrating the flow of a process in which the image processing apparatus  130  according to the embodiment establishes wireless communication with a portable terminal device  140 ; 
         FIG. 4  is a schematic diagram illustrating a UI  410  that performs a management setting of setup information according to the embodiment; 
         FIG. 5  is a schematic diagram illustrating a UI  510  that performs a management setting of setup information according to another embodiment; and 
         FIG. 6  is a schematic diagram illustrating a UI  610  that displays a communication system of a main communication unit specified by setup information management UIs  410  and  510 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following the present invention will be described using an embodiment; however, the present invention is not limited to the embodiment described below.  FIG. 1  is a schematic diagram illustrating a communication system  100  according to the embodiment. The communication system  100  is configured such that it includes a network  110 , a base station device  120  connected to the network  110 , an image processing apparatus  130 , a portable terminal device  140 , a client personal computer (PC)  150 , and a server device  160 . The network  110  is configured as a network that uses, for example, an Ethernet (registered trademark) and a TCP/IP protocol. Furthermore, the network  110  can be implemented as a local area network (LAN). 
     The base station device  120  is a radio wave relay device that allows wireless LAN communication and is used as an access point among the image processing apparatus  130 , the portable terminal device  140 , and the client PC  150 . The base station device  120  is connected to the network  110 . The image processing apparatus  130 , the portable terminal device  140 , and the client PC  150  can access, via the base station device  120 , the server device  160  connected to the network  110 . 
     The image processing apparatus  130  is configured as an image processing apparatus that has a wireless communication function. The image processing apparatus  130  can perform a printing process by receiving, using wireless communication via the base station device  120 , print data, such as image data or text data. Furthermore, in addition to performing a printing process by receiving print data via the base station device  120  in an infrastructure mode, the image processing apparatus  130  can also performs a printing process by directly receiving, from the portable terminal device  140  or the like, print data in an ad hoc mode that is a peer-to-peer connection. 
     The image processing apparatus  130  can include a scanning apparatus that is configured to include a charge coupled device (CCD) sensor or the like. The image processing apparatus  130  can send scan data that is scanned by a scanning apparatus to the portable terminal device  140 , the client PC  150 , or the server device  160  using wireless communication. 
     The image processing apparatus  130  includes, for example, a processor, a ROM, a RAM, and a hard disk drive (HDD). The image processing apparatus  130  executes, under an operating system (OS), such as UNIX (registered trademark) or LINUX (registered trademark), a program of the embodiment written in a programming language, such as an assembler, C, C++, JAVA (registered trademark), or Java (registered trademark) Script, thereby implementing a function, which will be described later. The image processing apparatus  130  can be configured as a multi function printer (MFP) that is a multifunctional image processing apparatus capable of, for example, printing, scanning, and copying. 
     The portable terminal device  140  is a terminal device that has a wireless communication function. The portable terminal device  140  can allow the image processing apparatus  130  to perform a printing process by sending print data using the ad hoc communication. Furthermore, the portable terminal device  140  can receive, using the ad hoc communication, various kinds of data, such as image data, that is scanned by the image processing apparatus  130 . Furthermore, the portable terminal device  140  can access the server device  160  via the base station device  120 . Examples of such a portable terminal device  140  include mobile devices, such as personal digital assistants (PDAs), laptop computers, and mobile phones; however, the portable terminal device  140  is not limited thereto. 
     The client PC  150  is a terminal device that has a wireless communication function. The client PC  150  can allow the image processing apparatus  130  to perform a printing process by sending print data via the base station device  120  using wireless communication. Furthermore, the client PC  150  can access the server device  160  via the base station device  120  using wireless communication. 
     The server device  160  can receive/supply various kinds of data from/to the image processing apparatus  130 , the portable terminal device  140 , and the client PC  150  using the wireless communication via the base station device  120 . 
       FIG. 2  is a functional block diagram illustrating the image processing apparatus  130  according to the embodiment. In the following, a processing function included in the image processing apparatus  130  will be described with reference to  FIG. 2 . 
     The image processing apparatus  210  includes an application  220 , a security control unit  222 , a communication control unit  224 , a display control unit  226 , and a printing processing unit  228 . The application  220  is a program that executes an association process for establishing a connection using wireless communication and establishes wireless communication between the image processing apparatus  210 , the base station device  120 , and the portable terminal device  140 . In the association process, wireless communication is established by both of the communication devices sharing connection information (hereinafter, referred to as “association information”), such as identification information on the wireless LAN network, such as an extended service set identifier (ESSID) or a service set identifier (SSID); sharing authentication information, such as a MAC address or an unique identification number, that uniquely identifies a portable terminal device or a base station device; and sharing encryption information, such as a encryption key that encrypts communication data. 
     The security control unit  222  is a function unit that stores security information, such as association information, in a nonvolatile memory in the image processing apparatus  210  or obtains the security information from the nonvolatile memory. The association information stored as the security information is stored for a period specified by a user using an user interface that manages and sets setup information that is setting information on wireless communication displayed on an operation panel in the image processing apparatus  130  (hereinafter, referred to as a “setup information setting UI”). Furthermore, the security control unit  222  can delete the association information if wireless communication is disconnected or if wireless communication is in an idle state. The user can specify, using the setup information setting UT, whether the association information is deleted. 
     In another embodiment, the security control unit  222  can store, in a nonvolatile memory, the association information on the portable terminal device  140  with which wireless communication is established. Then, using authentication information on the association information on the portable terminal device  140  that previously performed wireless communication, the application  220  performs an authentication process to establish wireless communication. Accordingly, the association process can be simplified. 
     The communication control unit  224  is a function unit that controls wireless communication of the image processing apparatus  130 . The communication control unit  224  controls a main communication unit  240  and a sub communication unit  242  using a device driver  232  of the main communication unit  240  and a device driver  234  of the sub communication unit  242  that will be described later. The communication control unit  224  sends to/receives from, the base station device  120  or the portable terminal device  140  via the sub communication unit  242 , association information to establish wireless communication. Then, the communication control unit  224  performs, with respect to the main communication unit  240 , wireless LAN communication, ultra wide band (UWB) communication using a wireless USB (WUSB), and wireless communication using Bluetooth. 
     Furthermore, the communication control unit  224  monitors the communication state of the main communication unit  240  and the sub communication unit  242  and stores the communication state in a storage unit such as a RAM (not shown) in the image processing apparatus  130 . In the embodiment, using an event notification (e.g., a normal notification or an error notification) that indicates the communication state issued by the main communication unit  240  and the sub communication unit  242 , the communication control unit  224  determines the communication state of the main communication unit  240  and the sub communication unit  242 . Furthermore, using an event notification that indicates the commencement or completion of communication issued by the main communication unit  240  and the sub communication unit  242 , the communication control unit  224  determines the commencement or completion of wireless communication. 
     Furthermore, if the setup information setting UI specifies the time available for wireless communication, the communication control unit  224  can end wireless communication after the specified time has elapsed. At this time, if the setup information setting UI specifies that the association information is to be deleted, the security control unit  222  deletes the association information stored in the nonvolatile memory in the image processing apparatus  130 . 
     Furthermore, the communication control unit  224  can communicate with the portable terminal device  140  by encrypting communication data. In addition to an encryption key specified by an administrator of the image processing apparatus  130 , an encryption key held by the portable terminal device  140  can be used for encrypting the communication data. When the encryption key held by the portable terminal device  140  is used, only a high security encryption key subjected to an association process, which will be described later, is permitted. 
     The display control unit  226  is a function unit that controls a display unit, such as an operation panel arranged in the image processing apparatus  130 . The display control unit  226  displays the setup information setting UI on the display unit in the image processing apparatus  130  and receives setup information specified by a user. Then, the display control unit  226  stores the setup information in the nonvolatile memory in the image processing apparatus  130 . Furthermore, the display control unit  226  obtains the setup information from the nonvolatile memory and displays the setup information on an UI that displays the communication system of the main communication unit. Details of these UIs will be described later together with the information that is displayed. 
     The printing processing unit  228  is a function unit that receives print data and then prints the print data. After wireless communication is established with a peripheral device, such as the base station device  120  or the portable terminal device  140 , the image processing apparatus  210  receives print data via the base station device  120  or receives print data from, for example, the portable terminal device  140  and allows the printing processing unit  228  to print the print data. 
     Furthermore, the image processing apparatus  130  includes an operating system (hereinafter, referred to as an “OS”)  230 , the main communication unit  240 , the sub communication unit  242 , and a nonvolatile memory  244 . 
     The OS  230  includes the main communication unit driver  232  and the sub communication unit driver  234 . The main communication unit driver  232  is a device driver that controls the main communication unit  240  by controlling data communication performed by the main communication unit  240 . The sub communication unit driver  234  is a device driver that controls the sub communication unit  242  by controlling data communication performed by the sub communication unit  242 . 
     The main communication unit  240  is a device that performs wireless communication with a peripheral device. In accordance with setup information, which will be described later and which is setting information of wireless communication, wireless communication is available, such as wireless LAN communication, performed in the infrastructure mode or in the ad hoc mode; UWB communication using an WUSB; and wireless communication using Bluetooth. In the embodiment, in the wireless LAN communication in the infrastructure mode, the main communication unit  240  receives data, such as print data, via the base station device  120 . Furthermore, in the wireless LAN communication in the ad hoc mode, the main communication unit  240  receives data, such as print data, from the portable terminal device  140  or sends scan data to the portable terminal device  140 . Furthermore, in the UWB communication using the WUSB, the main communication unit  240  receives data, such as print data, from the WUSB or the like or sends scan data to, for example, the WUSB. Furthermore, in wireless communication using Bluetooth, the main communication unit  240  receives data, such as print data, from the portable terminal device  140  or sends scan data to the portable terminal device  140 . 
     The image processing apparatus according to the embodiment includes a single main communication unit; however, in another embodiment, multiple main communication units can be included. In such a case, wireless communication can be performed by specifying, for each main communication unit, for example, wireless LAN communication, WUSB communication, and Bluetooth. 
     The sub communication unit  242  is a device that performs an association process for establishing wireless communication with a peripheral device. In the embodiment, in a near field communication (NFC) system or a push button configuration (PBC) system, the sub communication unit  242  sends to/receives from the peripheral device association information. In another embodiment, the sub communication unit  242  can send to/receive from the peripheral device the association information in a personal identification number (PIN) system. 
     The nonvolatile memory  244  stores therein association information that is used in the association process. The association information is stored, for each portable terminal device  140  that performs wireless communication, in the nonvolatile memory  244  for a period of time specified by the user. Furthermore, the nonvolatile memory  244  stores therein setup information that is set by the setup information setting UI or information constituting the setup information setting UI. A system administrator or the like can register the information constituting the setup information setting UI in the image processing apparatus  130 . 
       FIG. 3  is a flowchart illustrating the flow of a process in which the image processing apparatus  130  according to the embodiment establishes wireless communication with the portable terminal device  140 . In the following, a process for establishing wireless communication will be described with reference to  FIG. 3 . 
     The process illustrated in  FIG. 3  starts at Step S 300 . At Step S 301 , the sub communication unit  242  in the image processing apparatus  130  determines whether an association process request (hereinafter, referred to as an “association process request”) is received. If the sub communication unit  242  determines that an association process request is not received (No at Step S 301 ), the sub communication unit  242  repeats the process of Step  5301 . In contrast, if the sub communication unit  242  determines that an association process request is received (Yes at Step S 301 ), the process proceeds to Step S 302 . 
     At Step S 302 , the sub communication unit  242  notifies the application  220  that the association process request is received, and the application  220  determines the type of method of requesting the association process from the association process request (hereinafter, referred to as an “association process request method”). In the embodiment, information that identifies the association process request method is contained in the association process request. The application  220  can determine the association process request method using the information. Furthermore, in the embodiment, the association process request method can be a request method using the NFC system, the PBC system, or the PIN system. 
     At Step S 303 , the application  220  obtains the communication state of the main communication unit that is stored in the RAM in the image processing apparatus  130  and determines whether the communication state of the main communication unit is normal. If the communication state of the main communication unit is normal (Yes at Step S 303 ), the process proceeds to Step S 304 . In contrast, if the communication state of the main communication unit indicates an error (No at Step S 303 ), the process returns to Step S 301  and repeats the process. In another embodiment, if the communication state of the main communication unit indicates an error, that state can be displayed on the display unit in the image processing apparatus  130  and be notified to the portable terminal device  140  that is attempting wireless communication. 
     At Step  5304 , the application  220  obtains the setup information stored in the nonvolatile memory  244  and then obtains, for example, the communication system, the communication mode, the encryption condition of communication data, and the continuing condition of the main communication of the main communication unit that is set in the association process request method specified at Step  302 . At Step S 305 , the application  220  determines whether the association information is received from the portable terminal device  140  via the sub communication unit  242 . If the application  220  determines that the association information is not received (No at Step S 305 ), the process proceeds to Step S 306 . 
     At Step S 306 , the application  220  determines, using setup information, whether the association process using the association process request method can be performed. The determination can be performed by checking whether an association process request method, for example, association using the NFC, the PBC, or the PIN, is allowed. Furthermore, the determination can be performed by checking whether a portable terminal device that sends an association process request can use an encryption key that satisfies the encryption condition. Furthermore, the determination can also be performed, by a portable terminal device that sends an association process request, using authentication information, such as identification information or a MAC address that are not allowed to be connected using wireless communication. 
     If the application  220  determines that the association process using the association process request method cannot be performed (No at Step S 306 ), the process returns to Step S 301  and repeats the process. In contrast, if the application  220  determines that the association process using the association process request method can be performed (Yes at Step S 306 ), the process proceeds to Step S 307 . At Step  5307 , the application  220  supplies the association information to the portable terminal device  140  via the sub communication unit  242 . 
     In contrast, if the application  220  determines that the association information is received (Yes at Step S 305 ), the process proceeds to Step S 308 . At Step S 308 , the application  220  determines whether the association information received from the portable terminal device  140  can be allowed. This determination can be performed in a similar manner as that performed at Step S 306 . 
     If the application  220  determines that the association information cannot be allowed (No at Step S 308 ), the process returns to Step S 301  and repeats the process. In contrast, if the application  220  determines that the association information can be allowed (Yes at Step S 308 ), the process proceeds to Step  5309 . 
     At Step S 309 , the main communication unit  240  performs wireless communication with the portable terminal device  140  in accordance with the setup information and the association information. At Step S 310 , the application  220  determines whether wireless communication performed by the main communication unit  240  satisfies the continuing condition of the main communication obtained at Step S 304 . If the application  220  determines that the continuing condition of the main communication is satisfied (Yes at Step S 310 ), the process of Step  5310  is repeated. If the application  220  determines that the continuing condition of the main communication is not satisfied (No at Step S 310 ), the process returns to Step S 301  and repeats the process. 
     In the embodiment, after the main communication unit  240  establishes wireless communication at Step  5309 , the image processing apparatus  130  receives print data via the main communication unit  240  from the portable terminal device  140  in which communication is established and then allows the printing processing unit  228  to print the print data. 
       FIG. 4  is a schematic diagram illustrating the setup information setting UI  410  according to the embodiment. The setup information setting UI  410  is a UI that sets setup information on the association using the NFC system. If the sub communication unit  242  in the image processing apparatus  130  receives an association process request using the NFC system, the application  220  allows the main communication unit to perform wireless communication in accordance with the setup information specified by the setup information setting UI  410 . 
     The setup information setting UI  410  includes a field  420  that sets setup information on the association process using the NFC system. The field  420  includes a radio button that specifies whether the association process using the NFC system is always permitted. A user can specify, using the radio button, whether the image processing apparatus  130  performs the association process using the NFC system. In the embodiment, if a user specifies that the association process using the NFC system is always permitted, “valid” is displayed as the “NFC state” in the field  420 . In contrast, if a user specifies that the association process using the NFC system is always not permitted, “invalid” is displayed as the “NFC state” in the field  420 . 
     Furthermore, the field  420  includes a pull-down menu with which the communication system of the main communication unit is specified. In  FIG. 4 , UWB/WUSB is selected as the communication system of the main communication unit. In the embodiment, wireless LAN communication, Bluetooth, or the like can be specified as the communication system of the main communication unit. In the embodiment, wireless LAN  1  or  2  can be specified as the wireless LAN communication. The wireless LAN  1  indicates wireless communication in the ad hoc mode, where a logical network that is established by the wireless communication using the ESSID or the SSID can be specified. The wireless LAN  2  indicates wireless communication in the infrastructure mode, where a logical network that is established by the wireless communication using the ESSID or the SSID, can be specified in a similar manner to the wireless LAN  1 . 
     Furthermore, the field  420  also includes a pull-down menu with which the communication mode of the main communication unit is specified. In  FIG. 4 , WiMedia Link-layer protocol (WLP) that is a protocol used in the UWB is selected as the communication mode of the main communication unit. In the embodiment, in addition to the WLP, the ad hoc mode or the like can be specified as the communication mode in the main communication unit. 
     Furthermore, the field  420  also includes the radio button for specifying permission of the encryption condition for communication data, i.e., specifying whether to permit the encryption of data that is transmitted using wireless communication. The radio button is also used to specify whether to permit the use of a vulnerable encryption. A user can request, using the radio button, encryption of wireless communication data. Accordingly, with the image processing apparatus according to the embodiment, the security of wireless communication data can be enhanced. 
     The field  420  further includes a radio button that is used to specify whether to delete association information if wireless communication is disconnected or if wireless communication is not performed, i.e., in an idle state. A user can specify, using this radio button, whether to delete the association information. 
     Furthermore, the field  420  includes a pull-down menu that specifies the wireless communication time. The communication control unit  224  in the image processing apparatus  130  ends wireless communication if wireless communication time reaches the time specified by the pull-down menu. In the embodiment, the communication time used can be in seconds; however, in another embodiment, the communication time used can be in seconds or hours. Furthermore, if the time specified by the pull-down menu has elapsed, the field  420  further includes a radio button that specifies whether to delete the association information. When the radio button specifies that association information is deleted, if wireless communication ends because the wireless communication time reaches the predetermined time, the security control unit  222  in the image processing apparatus  130  deletes the association information on the wireless communication stored in the nonvolatile memory  244 . 
     The field  420  further includes a field that indicates a state of the main communication unit or a communication state thereof. The display control unit  226  receives, from the communication control unit  224 , a state of the main communication unit or a communication state thereof and displays it on the setup information setting UI  410 . 
       FIG. 5  is a schematic diagram illustrating a UI  510  that performs management setting of setup information according to another embodiment. The setup information setting UI  510  is a UI that sets setup information on the association using the PBC system. If the sub communication unit  242  in the image processing apparatus  130  receives an association process request using the PBC system, the application  220  allows the main communication unit to perform wireless communication in accordance with the setup information specified by the setup information setting UI  510 . The function of the setup information setting UI  510  is the same as that of the setup information setting UI  410  that sets association using the NFC system. Accordingly, a description thereof in detail will be omitted. 
       FIGS. 4 and 5  are schematic diagrams illustrating setup information setting UIs that set association using the NFC system or the PBC system; however, in another embodiment, setup information can be specified using a setup information setting UI that sets association using the PIN system, which is similar to the setup information setting UIs  410  and  510 . 
       FIG. 6  is a schematic diagram illustrating a UI  610  that displays a communication system of a main communication unit specified by the setup information management UIs  410  and  510  illustrated in  FIGS. 4 and 5 . The display control unit  226  obtains, from the nonvolatile memory  244  in the image processing apparatus  130 , information specified by the setup information setting UI and displays the information on the UI  610 . A user can determine, by referring to the UI  610 , which communication system is valid in the main communication unit. 
     In the embodiment, communication is established with, for example, a terminal device that has a wireless communication function; however, in another embodiment, the image processing apparatus can establish communication with other terminal devices using a wire. In such a case, the image processing apparatus can establish communication by receiving connection information, such as authentication information including a MAC address or an individual identification number that uniquely identify a terminal device, encryption information including an encryption key that encrypts communication data, or the like. Accordingly, it is also possible to improve the security of communication data using a wire. 
     According to an aspect of the present invention, in accordance with an association process request system, it is possible to switch wireless communication systems performed by a main communication unit. 
     According to another aspect of the present invention, a user can arbitrarily select a communication system or a communication mode of wireless communication used in the main communication unit, thus enhancing general versatility of wireless communication. Furthermore, it is possible to eliminate wireless communication with a communication device that uses a vulnerable encryption key, thus enhancing the security of communication data received by an image processing apparatus. Furthermore, because it is possible to end wireless communication between the main communication unit and a communication device after a predetermined time has elapsed, unnecessary latency time can be reduced in a case in which a communication device performs wireless communication with the image processing apparatus and then another communication device establishes wireless communication with the image processing apparatus. 
     Furthermore, the present invention provides a method that is performed by the image processing apparatus that can perform data communication using wireless communication established by performing an association process, and the present invention provides a program and a recording medium therefor. 
     Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.