Patent Publication Number: US-2006002531-A1

Title: Telephone system in multi-function products and method and medium for operating the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims the benefit of Korean Patent Application No. 2004-51004, filed on Jul. 1, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a multi-function product operation system and a method and medium for operating the same, and more particularly, to a telephone system and a method and medium for operating the telephone system in a multi-function product equipped with an analog telephone circuit to realize a telephone function such that analog voice signals can be sent/received at a low price.  
      2. Description of the Related Art  
      Multi-function product (MFP) such as office automation instruments can perform a number of functions such as a telephone function, a printer function, a copier function, a scanner function, and a fax function.  
       FIG. 1  is a block diagram showing a configuration of an MFP, which is equipped with a conventional telephone function.  
      Referring to  FIG. 1 , the MFP includes a main portion  100 , a line portion  200 , a data transmission unit  300  which transmits data between the main portion  100  and the line portion  200 , and a public telephone network  400 .  
      Generally, the main portion  100  includes a central processing unit (CPU)  110 , a memory  120 , a modem unit  130 , a line interface unit  140 , a telephone control unit (analog telephone circuit)  150  which is equipped with a frequency conversion unit  151 , a level conversion unit  152 , and an A/D-D/A conversion unit  153 , and a receiver  160 .  
      Generally, the line portion  200  includes a line portion processing unit (IC)  210  which is equipped with a modem interface unit  211 , an A/D-D/A conversion unit  212 , a level conversion unit  213 , a ring signal detection unit  214 , an alternating current signal input unit  215 , a direct current control unit  216 , and an alternating current signal output unit  217 , a bridge diode unit  220 , and a public telephone network connection unit  230 .  
      In the multifunction product (MFP) shown in  FIG. 1 , the bridge diode BD  220  of the line portion  200  always applies forward voltage to the transistors Tr 1  and Tr 2  even if the polarity of a switch which is connected to the public telephone network connection unit  400  is reversed. The transistor Tr 1 , the resistor R 1 , and the direct current control unit  216  allow a predetermined direct current to flow into the public telephone network connection unit  400 . The transistor Tr 2 , a resistor R 2 , and the alternating current signal output unit  217  of the line portion processing unit  210  amplify the output alternating current signals to transmit the signals to the public telephone network. A capacitor C 1  removes a direct current component out of alternating current signals input via the public telephone network connection unit  400  and delivers the signals to the alternating current signal input unit  215 .  
       
      As described above, the line portion processing unit  210  which interacts with the public telephone network connection unit  230  which includes the transistors Tr 1  and Tr 2 , resistors R 1  and R 2 , and the capacitor C 1  is generally called data access arrangement (DAA) unit.  
      Capacitors C 1 , C 2 , and C 3  remove a direct current component form alternating current signals.  
      The data transmission unit  300  is interposed between the main portion  100  and the line portion  200 , and the data transmission unit  300  transfers arranged data signals and clock signals.  
      The main portion  100  processes fax signals and voice signals as well known. The modem unit  130  is connected to the data transmission unit  300  via the line interface unit  140  and sends/receives fax signals and the voice signals.  
      When fax signals are sent/received, an output signal generated by the modem unit  130  is converted into a digital data format via the line interface unit  140  and is delivered to the modem interface unit  211  of the line portion processing unit  210  via the data transmission unit  300 . The digital data is converted into a current signal via the modem interface unit  211  of the line portion processing unit  210  and is output to a base plate of the transistor Tr 2  by the current signal output unit  217 . The transistor Tr 2  amplifies an input current signal and outputs the amplified current signal to the public telephone network  400 .  
      When the voice alternating current signal is sent/received, first, when a ring signal is input to the MFP via the public telephone network  400 , input of the ring signal is delivered to the main portion  100  via the ring signal detection unit  214 . The main portion  100  recognizes the ring signal, and a contracted control command operates the direct current control unit  216  via the data transmission unit  300  to be connected to a telephone line. Next, a voice alternating current signal input to the public telephone network  400  is input to the alternating current input unit  215 . The input alternating current signal is converted into a digital signal via the A/D-D/A conversion unit  212  and is transmitted to the main portion  100  via the data transmission unit  300 . In the main portion  100 , a digital signal transmitted in a predetermined form is restored to retrieve the voice digital signal, the voice digital signal is delivered to the telephone control unit  150 , the voice digital signal is converted into the voice alternating current signal via the A/D-D/A conversion unit  153 , and the voice alternating current signal is delivered to the receiver  160  such that a user can hear the voice signal of a person on the other end of the line. When a voice alternating current signal is transmitted from the receiver  160  of the MFP to the public telephone network  400 , the process is reversed.  
      In the line portion  200 , and more particularly, in an MFP having telephone function using the line portion processing unit  210 , the telephone function uses the telephone control unit  150  of the main portion  100 . When the telephone control unit  150  is used, an analog voice signal received from the public telephone network  400  has to be converted into a digital signal. Therefore, a voice signal heard by a user is not natural. To solve this problem, a conversion circuit having better efficiency is needed, and thus, the price of the telephone control unit  150  is increased.  
     SUMMARY OF THE INVENTION  
      Additional aspects, features, and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.  
      The present invention provides a telephone system of a multi-function product and a method and medium for operating the telephone system in which analog voice signals can be sent/received at a low price.  
      According to an aspect of the present invention, there is provided a telephone system in a multi-function product, the system including: a signal processing unit which receives ring signals, voice alternating current signals, and fax signals input from a public telephone network, digitally processes the received fax signals according to a control signal, transmits the received voice alternating current signal to a receiver, converts a fax signal to be sent into analog form, and transmits a voice alternating current signal to the public telephone network; a telephone circuit which amplifies and signal processes the switched voice alternating current signal and then outputs the switched voice alternating current signal to a receiver or signal processes a voice signal input to the receiver and then outputs the voice signal to the signal processing unit; and a control unit which determines whether the telephone system is in a telephone mode or a fax mode according to whether a receiver is on or off the hook and outputs a control signal to output the switched voice alternating current signal to the telephone circuit or a control signal to print and store the switched fax signal.  
      The system may further include a first data transmission unit that sends/receives digital fax data between the signal processing unit and the control unit, and a second data transmission unit that sends/receives a voice alternating current signal between the signal processing unit and the telephone circuit.  
      When the receiver is in an off-hook state, the multi-function product may be determined to be in a telephone mode and the control unit outputs a control signal to output the switched voice alternating current signal to the telephone circuit, and when the receiver is in an on-hook state, the multi-function product may be determined to be in a fax mode and the control unit outputs a control signal to print and store the signal processed fax signal.  
      According to another aspect of the present invention, there is provided a method of operating a telephone system in a multi-function product, including the operations of: (a) determining whether a receiver is in an off-hook or on-hook state when a ring signal is sensed; (b) determining whether a multi-function product is in a telephone mode or a fax mode according to whether the receiver is in the off-hook or on-hook state; and (c) analog processing a voice alternating current signal input from the public telephone network in a telephone circuit and then outputting the analog processed voice alternating convert signal to the receiver, or digital processing a fax signal input from the public telephone network to print or store the fax signal, according to the determined mode of the multi-function product.  
      When the receiver is in the off-hook state, the voice alternating current signal may be analog processed and then output to the receiver after determining the multi-function product is in a telephone mode, and when the receiver is in the on-hook state, the digital processed fax signal may be printed or stored after determining the multi-function product is in a fax mode.  
      According to another aspect of the present invention, there is provided at least one computer readable medium for storing instructions that control at least one processor which executes a method of operating a telephone system in a multi-function product, the method including determining whether a receiver is in an off-hook or on-hook state when a ring signal is sensed; determining whether a multi-function product is in a telephone mode or a fax mode according to whether the receiver is in the off-hook or on-hook state; and analog processing a voice alternating current signal input from the public telephone network in a telephone circuit and then outputting the analog processed voice alternating convert signal to the receiver, or digital processing a fax signal input from the public telephone network to print or store the fax signal, according to the determined mode of the multi-function product. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      These and/or other aspects, features, and advantages of the present invention will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings of which:  
       FIG. 1  is a block diagram showing a configuration of a multi-function product (MFP) which is equipped with a conventional telephone function;  
       FIG. 2  is a block diagram showing a configuration of a telephone system of an MFP, according to an exemplary embodiment of the present invention; and  
       FIG. 3  is a flow chart showing a method of operation of the telephone system of an MFP, according to an exemplary embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The exemplary embodiments are described below to explain the present invention by referring to the figures.  
       FIG. 2  is a block diagram showing a configuration of a telephone system in a multi-function product (MFP). The telephone system includes a main portion  100 , a line portion  200 , a first data transmission unit  300 , a second data transmission unit  350 , and a public telephone network  400 .  
      The main portion  101  includes a central processing unit (CPU)  110 , a memory  120 , a modem  130 , a line interface unit  140 , an analog telephone circuit  150 , and a receiver  160 . The line portion  201  includes a line portion processing unit (IC)  310  which is equipped with a modem interface unit  211 , an A/D-D/A conversion unit  212 , a level conversion unit  213 , a ring signal detection unit  214 , an alternating current signal input unit  215 , a direct current control unit  216 , an alternating current signal output unit  217 , an analog signal switching unit  218 , an analog signal interface unit  219 , a bridge diode  220 , and a public telephone network connection unit  230 .  
      One of the differences between the conventional configuration shown in  FIG. 1  and the configuration of an exemplary embodiment shown in  FIG. 2  is the addition of the analog signal switching unit  218  and the analog signal interface unit  219  in the line portion processing unit (IC)  310  in order to connect an analog voice signal to the public telephone network  400  without converting the analog voice signal into a digital signal. Also, a second data transmission unit  350  is added in order to deliver an analog voice signal between the main portion  101  and line portion  201 .  
      Operations of an exemplary embodiment of the telephone system of the present invention that are different from a conventional telephone system will be described.  
      The CPU  110  determines whether a user has taken the receiver off the hook or not after a ring signal and recognizes that the MFP is in a facsimile mode or in a telephone mode. When the user has taken the receiver  160  off the hook, the CPU  110  determines that the MFP is in the telephone mode, and when the user puts the receiver  160  on the hook, the CPU  10  determines that the MFP is in the facsimile mode.  
      When the MFP is in the telephone mode, a voice alternating current signal of a person on the other end of the line is input to the alternating current signal input unit  215  of the line portion processing unit (IC)  310  via the public telephone network connection unit  230 .  
      In a telephone mode, the analog signal switching unit  218  switches an input analog voice signal output from the alternating current input unit  215  to output the input analog voice signal to the analog signal interface unit  219 , and the analog signal interface unit  219  transmits the switched analog voice signal to the analog telephone circuit  150  via the second data transmission unit  350 .  
      The analog telephone circuit  150  amplifies the analog voice signal input from the second data transmission unit  350 , signal processes the analog voice signal according to characteristics of voice volume, and outputs the analog voice signal to the receiver  160 . Therefore, a final user can hear a voice signal of a person on the other end of the line.  
      When the voice of the person on the other end of the line is delivered to the final user via the receiver  160 , an analog voice output from the receiver  160  is input to the analog telephone circuit  150  to be signal processed. The signal processed analog voice signal is transmitted to the person on the other end of the line via the second data transmission unit  350 , the analog signal interface unit  219 , the analog signal switching unit  218 , the public telephone network connection unit  230 , and the public telephone network  400 .  
      When the MFP is in the fax mode, a case of receiving a fax signal will be described. An analog fax signal input via the public telephone network  400  is converted into a digital fax signal in the A/D-D/A conversion unit  212  of the line portion processing unit (IC)  310 . The digital fax signal having a contract form and is sent to the main portion  101  via the modem interface unit  211  and the first data transmission unit  300  to be stored in the memory  120  or to be printed.  
      Transmission of a fax signal when the MFP is in the fax mode will be described. An output signal generated in the modem  130  is converted into a digital data form by the line interface unit  140  and is delivered to the modem interface unit  211 . The digital fax signal is converted into an analog fax signal again by the A/D-D/A conversion unit  212 , and the alternating current signal output unit  217  transmits the analog fax signal to the public telephone network  400  via the public telephone network connection unit  230 .  
       FIG. 3  is a flow chart showing an operating method of a telephone system of an MFP, according to an exemplary embodiment of the present invention.  
      Referring to  FIGS. 2 and 3 , the CPU  110  determines whether or not a ring signal is detected by the public telephone network  400  (operation S 301 ).  
      The CPU  110  determines whether a user has taken the receiver  160  off the hook after detecting the ring signal (operation S 302 ).  
      When the user has taken the receiver  160  off the hook, the CPU  110  determines that the MFP is in a telephone mode (operation S 303 ).  
      When the MFP is in the telephone mode, a voice alternating current signal of a person on the other end of the line, which is input from the public telephone network  400 , is input to the alternating current input unit  215  via the public telephone network connection unit  230 . The analog signal switching unit  218  switches the input analog voice signal output from the alternating current signal input unit  215  to output to the analog signal interface unit  219 . The analog signal interface unit  219  transmits the switched analog voice signal to the analog telephone circuit  150  via the second data transmission unit  350  (operation S 304 ).  
      The analog telephone circuit  150  amplifies the analog voice signal input from the second data transmission unit  350 , signal processes the analog voice signal according to the characteristics of the sound volume, and outputs the processed analog voice signal to the receiver  160 . Therefore, a final user can hear the voice signal of the person on the other end of the line (operation S 305 ).  
      When a voice alternating current signal is transmitted from the receiver  160  to the public telephone network  400 , it performs the sequence described above in reverse order.  
      When the user puts the receiver  160  on the hook, the CPU  110  determines that the MFP is in a fax mode (operation S 306 ).  
      When the MFP is in the fax mode, an analog fax signal input via the public telephone network  400  is converted into a digital fax signal in the A/D-D/A conversion unit  212  of the line portion processing unit (IC)  310  (operation S 307 ).  
      To transmit the digital fax signal to the main portion  101 , the digital fax signal gets to have a contract form to be sent to the main portion  101  via the modem interface unit  211  and the first data transmission unit  300  and is stored or printed (operation S 308 ).  
      According to the present invention as described above, an MFP may be equipped with an analog telephone circuit to realize a telephone function such that an analog voice signal may be sent/received at a low price.  
      According to the present invention as described above, it is understood that the communication among the main portion  101 , first data transmission unit  300 , second data transmission unit  350 , and line portion  310  may be wired or wireless.  
      The method of operating a telephone system in a multifunction product according to the present invention can be embodied as a computer program or set of instructions (computer program instructions). Code or code segments of the computer program can be provided by a computer programmer skilled in the art. The computer program may be stored in a computer readable medium or a plurality of computer readable media. The method can be realized by reading and executing the program with a computing device or other programmable apparatus in a multifunction product. The computing device may include a processor or a plurality of processors.  
      The method has been described with reference to examples and illustrations of methods according to exemplary embodiments of the invention. It will be understood that each block of the illustrations, and combinations of blocks in the illustrations, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a computing device of a multifunction product to produce a machine, such that the instructions, which execute via the processor of the computing device, implement the functions specified in the block or blocks. These computer program instructions may also be stored in a computer usable or computer-readable memory that can direct a computing device to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture to implement the function specified in the flowchart block or blocks. The computer program instructions may also be loaded onto a computing device to cause a series of operational steps to be performed on the computing device to produce a computer implemented process such that the instructions that execute on the computing device provide steps for implementing the functions specified in the flowchart block or blocks.  
      In addition, each block of the flowchart illustrations may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of the order. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in reverse order, depending on the functionality involved.  
      Examples of a computer-readable medium include a magnetic storage medium (e.g., a ROM, a floppy disk, or a hard disk), an optical storage medium (e.g., a CD-ROM or a DVD), and a carrier wave or digital transmission medium (e.g., data transmissions through the Internet).  
      Examples of the computer-readable medium further include any type of transmission medium including networks, which may be wired networks, wireless networks or any combination thereof. The computer-readable medium may be referred to as a medium, and the medium may be distributed among computing devices as part of one or more networks or coupled with one or more networks.  
      One or more computing devices may be part of a portable multifunction device, i.e., mobile nodes or terminals, enabling users to access a server or network such as the Internet. The mobile nodes or terminals may include laptop computers, web pads, hand-held PCs, personal digital assistants (PDAs), mobile phones, and so on.  
      Although a few exemplary embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these exemplary embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.