Patent Application
20080080489
These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
Reference will now be made in detail to the present 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 embodiments are described below in order to explain the present invention by referring to the figures.
The control unit 110 controls the whole operation of the communication system 100 according to predetermined programs. The storage unit 120 includes a ROM for storing various kinds of control programs required to implement the functions of the communication system 100 and a RAM for storing various kinds of data such as protocol data and text data generated while the control programs are executed, and the data is read out from or stored in the storage unit 120 under the control of the control unit 110. However, it is understood that other types of memory can be used, such that both ROM and RAM need not to be used.
The operation panel unit 130 includes a display unit 132 and a key input unit 134.
The display unit 132 displays the operation state of the communication system 100 under the control of the control unit 110. In addition, if transmit terminal identification (TTI) information is provided from the transmitter side, the display unit 132 displays called subscriber identification (CSI) information of the transmitter side among the TTI information under the control of the control unit 110. That is, the display unit 132 displays a country code, an area code, and a subscriber phone number of the transmitter side itself. For this, the display unit 132 may be implemented by an LCD panel, a 7-segment display, and so forth. Moreover, the display unit 132 can be connected to the system 100, such as on a television or computer monitor.
The key input unit 134 includes a plurality of manipulation keys that are manipulated by a user to input control signals based on the operation state of the communication system 100 displayed on the display unit 132. The control signals inputted through the manipulation keys are applied to the control unit 110 that controls the whole operation of the communication system 100. While described as keys, it is understood that other mechanisms can be used to input the control signals.
The operation panel unit 130 may include a touch screen panel in which the display unit 132 and the key input unit 134 are constructed in a body.
The scanning unit 140 forms image data by scanning a document, and transmits the image data to the control unit 110.
The printing unit 150 prints the image data received in the communication system 100 on a recording paper or any type of recording medium.
In the case where the communication system 100 operates as the transmitter side, the modem 160 modulates the image data into data in the form of an analog signal. In the case where the communication system 100 operates as a receiver side, the modem 160 demodulates the data in the form of an analog signal into digital data, under the control of the control unit 110.
The line interface unit (or public network interface device) 170 is connected to a tip terminal and a ring terminal of the telephone line. and the line interface unit 170 performs data interfacing between the modem 160 and the telephone line, under the control of the control unit 110. Here, like the off-hook detection unit shown in
A sensor unit 180 senses the residual quantity of the recording paper or the placement of a document to be scanned by the scanning unit 140. In addition, in the case where the printing unit 150 is provided with a device such as a fuser for fusing toner sprayed on the paper, the sensor unit 180 performs diverse sensing functions such as sensing of the temperature of the fuser in order to control the temperature of the fuser.
The communication system 100 according to the shown embodiment of the present invention further includes an audio processing unit 190 reading audio data stored in the storage unit 120, and converting and outputting the read audio data. However, it is understood that the processing unit 190 need not be included in all aspects of the invention.
The communication system 100 according to the shown embodiment of the present invention further includes an external signal input unit (not illustrated) for receiving a remote control signal outputted from a remote control unit 200, and the remote control signal may be inputted to the line interface unit 170 through the telephone line. However, it is understood that the external signal input unit need not be used in all aspects of the invention.
Referring to
The first switching unit 171 is connected to the tip terminal and the ring terminal of the telephone line, and is controlled by the control unit 110 to operate in either an on-hook mode (in which a ring signal, TTI information, and remote control signal outputted from the remote control unit 200 are applied), or an off-hook mode in which the image data is applied.
The second switching unit 172 selects one of a first signal channel 173a and a second signal channel 173b provided in the signal channel unit 173 under the control of the control unit 110. That is, as the first switching unit 171 operates in respective on-hook or off-hook modes. The second switching off-hook unit 172 selectively applies the signals to the signal conversion unit 174 through different paths.
The signal channel unit 173 includes the first signal channel 173a that is connected to the tip terminal and the ring terminal of the telephone line when the first switching unit 171 operates in the on-hook mode. The second signal channel 173b is connected to the tip terminal and the ring terminal of the telephone line when the first switching unit 171 operates in the off-hook mode.
The signal conversion unit 174 is connected to the first signal channel 173a by the switching operation of the first switching unit 171 and the second switching unit 172 in the on-hook mode, detects the ring signal applied through the telephone line, TTI information, and remote control signal outputted from the remote control unit 200 and applied through the telephone line, and converts the detected signals into a first detected signal. Also, the signal conversion unit 174 is connected to the second signal channel 173b by the switching operation of the first switching unit 171 and the second switching unit 172 in the off-hook mode, detects the image data applied through the telephone line, and converts the detected signals into a second detected signal.
The third switching unit 175 operates in association with the first switching unit 171, operates in either the on-hook mode or the off-hook mode, and selectively connects the first signal channel 173a or the second signal channel 173b to the signal amplifying unit 176.
The signal amplifying unit 176 is selectively connected to the first signal channel 173a or the second signal channel 173b by the switching operation of the third switching unit 175, and amplifies the first detected signal or the second detected signal outputted from the signal conversion unit 174 up to a predetermined voltage level, to output the amplified first or second detected signal so that the modem 160 can recognize the first or second detected signal.
Referring to
Also, the third switching unit 175 includes a switch element that is provided with a fixed terminal connected to a first input terminal of the signal amplifying unit 176 and a free terminal which is selectively connected to contacts DP31 and DP32. Contacts DP31 and DO32 are connected to the first signal channel 173a and the second signal channel 173b, respectively. The public network interface device 170 operates in the on-hook mode if the free terminal is connected to the first contact DP31, and operates in the off-hook mode if the free terminal is connected to the second contact DP32, under the control of the control unit 110.
For this, the first switching unit 171 and the third switching unit 175 may include relay switches that are switched between the contacts DP11 and DP12 and between the contacts DP31 and DP32, respectively, by the same control signal applied from the control unit 110.
The second switching unit 172 includes a switch element composed of a free terminal that is switched between a first contact DP21 connected to the first signal channel 173a and a second contact DP22 connected to the second signal channel 173b. The public network interface device 170 operates in the on-hook mode if the free terminal is connected to the first contact DP21, and operates in the off-hook mode if the free terminal is connected to the second contact DP22, under the control of the control unit 110.
For this, the second switching unit 172 may include a relay switch that is switched between the contacts DP21 and DP22 by the control signal applied from the control unit 110 to the first switching unit 171.
The signal channel unit 173 is provided with the first signal channel 173a and the second signal channel 173b.
The tip terminal is connected to the signal conversion unit 174, through the first signal channel 173a, when the first contact DP11 of the first switching unit 171 and the first contact DP21 of the second switching unit 172 are connected to their respective free terminals. The first signal channel 173a forms a closed loop between the tip terminal and the ring terminal when the first contacts DP11 and DP21 of the first switching unit 171 and the second switching unit 172 are connected to their free terminals, respectively, in the on-hook mode.
In addition, through the first signal channel 173a, the signal conversion unit 174 is connected to the first contact DP31 of the third switching unit 175. When the first contact DP31 of the third switching unit 175 is connected to the free terminal of the first signal channel 173a in the on-hook mode, the first signal channel 173a outputs the first detected signal (i.e., the ring signal detected by the signal conversion unit 174, the TTL information, and the remote control signal), to the signal amplifying unit 176 through the first contact DP31 of the third switching unit 175.
The first signal channel 173a includes capacitors C1 and C2 for intercepting a DC component, a first resistor R1 for satisfying the impedance regulations, and a second resistor R2 for compensating for a signal attenuated by the first resistor.
The tip terminal is connected to the signal conversion unit 174 through the second signal channel 173b, when the second contact DP12 of the first switching unit 171 and the second contact DP22 of the second switching unit 172 are connected to their respective free terminals. The second signal channel 173b forms a closed loop between the tip terminal and the ring terminal when the second contacts DP12 and DP22 of the first switching unit 171 and the second switching unit 172 are connected to their respective free terminals, in the off-hook mode.
The second signal channel 173b includes a full-wave rectifier BD1, which is connected to the tip terminal and the ring terminal through the second contact DP12 of the first switching unit 171. The full-wave rectifier BD1 rectifies the signals applied to the tip terminal and the ring terminal to satisfy the impedance regulations. Also, in the second signal channel 173b, elements R4, R5, C4, and TR1 for forming a closed loop between the tip terminal and the ring terminal, and a capacitor C5 for intercepting a DC component are provided. In addition, in the second signal channel 173b, a capacitor C6 for intercepting a DC component, and resistors R6 and R7 connected in series between the signal conversion unit 174 and the third switching unit 175 are provided.
The signal conversion unit 174 includes a transformer circuit T1.
The primary winding of the transformer circuit T1 is connected to the first signal channel 173a as the first contacts DP11 and DP21 of the first and second switching units 171 and 172 are connected to the free terminals of the switch elements, respectively, in the on-hook mode. Also, the secondary winding of the transformer circuit T1 is connected to the first signal channel 173a as the first contact DP31 of the third switching unit 175 is connected to the free terminal of the first signal channel, in the on-hook mode. That is, the transformer circuit T1 converts the ring signal, the TTI information, and the remote control signal, which are applied to the primary winding through the first signal channel 173a, into the first detected signal by amplifying the applied signals according to the predetermined turn ratio of the primary winding to the secondary winding, and outputs the first detected signal through the first signal channel 173a.
In addition, the primary winding of the transformer circuit T1 is connected to the second signal channel 173b as the second contacts DP12 and DP32 of the first and third switching units 171 and 175 are connected to the free terminals of the switch elements, respectively, in the off-hook mode. Also, the secondary winding of the transformer circuit T1 is connected to the second signal channel 173b as the second contact DP32 of the third switching unit 175 is connected to the free terminal of the first signal channel, in the off-hook mode. That is, the transformer circuit T1 converts the image data, which is applied to the primary winding through the second signal channel 173b, into the second detected signal by amplifying the applied image data according to the predetermined turn ratio of the primary winding to the secondary winding, and outputs the second detected signal through the second signal channel 173b.
In this case, the transformer circuit T1 may be constructed to have a high impedance, for example, a high impedance in the range of 20 kΩ˜30 kΩ, to satisfy the on-hook impedance regulations. By contrast, the transformer circuit T1 may be constructed to have a low impedance, for example, a low impedance in the range of 500Ω˜700Ω, to reduce the manufacturing cost. In this case, the first resistor R1 may have a high resistance value, for example, a high resistance value in the range of 20 kΩ˜30 kΩ, to satisfy the on-hook impedance regulations.
The signal amplifying unit 176 is connected to the fixed terminal of the third switching unit 175. Specifically, the signal amplifying unit 176 is connected to the first signal channel 173a through the first contact DP31 of the third switching unit 175 in the on-hook mode, and is connected to the second signal channel 173b through the second contact DP32 of the third switching unit 175 in the off-hook mode.
In the on-hook mode, the signal amplifying unit 176 amplifies the first detected signal detected by the signal conversion unit 174 and inputted through the first signal channel 173a up to a predetermined voltage level to output the amplified first detected signal. In the off-hook mode, the signal amplifying unit 176 amplifies the second detected signal detected by the signal conversion unit 174 and inputted through the second signal channel 173b to output the amplified second detected signal.
For this, the signal amplifying unit 176 includes an operational amplifier AMP having a first input terminal connected to the fixed terminal of the third switching unit 171b and a second input terminal connected to the ground electrode, a resistor R3 and a capacitor C3 connected in parallel to the operational amplifier to form a feedback loop.
The method of driving a public network interface device according to an embodiment of the preset invention further includes activating the second signal channel 173a for transmitting a second signal at operation S300, connecting the second signal channel with the common signal conversion unit (e.g., the signal conversion unit 174) at operation S310, and detecting the second signal having passed through the second signal channel and the common signal conversion unit at operation S320.
At operation S100, the control unit 110 judges whether the driving mode of the communication system 100 is the on-hook mode or the off-hook mode. For this, the line interface unit 170 is provided with an off-hook detection unit, such as the unit 14b as shown in
If the driving mode is the on-hook mode as a result of judgment at operation S100, the control unit 110 controls the first signal channel 173a to be activated by activating the first and third switching units 171 and 175 included in the line interface unit 170, (i.e., the public network interface device 170), at operation S200. That is, the control unit 110 activates the first signal channel 173a by outputting the control signal so that the respective free terminals of the first and third switching units 171 and 175 are connected to the first contacts DP11 and DP31, respectively.
At operation S210, the control unit 110 electrically connects the first signal channel 173a to the signal conversion unit 174 by activating the second switching unit 172 included in the public network interface device 170. That is, the control unit 110 connects the signal conversion unit 174 to the first signal channel 173a by outputting the control signal so that the free terminal of the second switching unit 172 is connected to the first contact DP21.
Here, operations S200 and S210 have been described as independent operations for clear description of the construction and for convenience in understanding. However, the first to third switching units 171, 172, and 173 may be simultaneously activated by the same control signal applied from the control unit 110.
At operation S220, if the first signal channel 173a is activated through operations S210 and S220 and the first signal channel 173a is connected to the signal conversion unit 174, the first signal applied through the tip terminal and the ring terminal (for example, the ring signal, the TTI information, and the remote control signal), is converted into the first detected signal through the transformer circuit T1. The first detected signal outputted from the transformer circuit T1 is amplified through the signal amplifying unit 176, and then outputted to the modem 160.
Then, the modem 160 demodulates the analog type signal outputted from the signal amplifying unit 176 into a digital signal, and applies the demodulated digital signal to the control unit 110.
If the present driving mode is the off-hook mode as a result of judgment at operation S100, the control unit proceeds to operation S300. At operation S300, the control unit 110 controls the second signal channel 173b to be activated by activating the first switching unit 171 included in the line interface 170 (i.e., the public network interface device 170). That is, the control unit 110 activates the second signal channel 173b by outputting the control signal so that the respective free terminals of the first and second switching units 171 and 175 are connected to the second contacts DP12 and DP32 thereof.
At operation S310, the control unit 110 electrically connects the second signal channel 173b to the signal conversion unit 174 by activating the second switching unit 172 included in the public network interface device 170. That is, the control unit 110 connects the signal conversion unit 174 to the second signal channel 173b by outputting the control signal so that the free terminal of the second switching unit 172 is connected to the second contact DP22 of the second switching unit 172.
Here, as similarly described at operations S200 and S210, it is apparent that operations S300 and S310 may be performed so as to simultaneously activate the first and second switching unit 171 and 172 through the same control signal applied from the control unit 110.
If the second signal channel 173b is activated through operations S310 and S320 and the second signal channel 173b is connected to the signal conversion unit 174, the second signal being applied through the tip terminal and the ring terminal (for example, the image data), is converted into the second detected signal through the transformer circuit T1 at operation S320. The second detected signal outputted through the transformer circuit T1 is amplified through the signal amplifying unit 176, and then outputted to the modem 160.
Thereafter, the modem 160 demodulates the analog type image data outputted from the signal amplifying unit 176 into digital type image data and provides the digital image data to the control unit 110.
As described above, the public network interface device, the communication system having the interface device, and a driving method thereof according to an aspect of the present invention, includes only one transformer circuit provided in a line interface unit LIU to detect signals being applied through a telephone line. Accordingly the manufacturing cost of the communication system can be reduced.
In addition, by reducing the number of transformers, the process margin is improved, and the system can be integrated and miniaturized.
Although a few 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 this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
While described in the context of a telephone line and/or communication network by way of example, it is understood that aspects of the invention can be used in other networks or communication paths in addition to or instead of a PSTN, communication networks, and/or telephone lines. Similarly, the ring terminal and tip terminal can be other terminal types having like signals according to the particular network in which it is used in other aspects.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-97451 | Oct 2006 | KR | national |
