CN1096786C - Facsimile receiving circuit - Google Patents
Facsimile receiving circuit Download PDFInfo
- Publication number
- CN1096786C CN1096786C CN97110557A CN97110557A CN1096786C CN 1096786 C CN1096786 C CN 1096786C CN 97110557 A CN97110557 A CN 97110557A CN 97110557 A CN97110557 A CN 97110557A CN 1096786 C CN1096786 C CN 1096786C
- Authority
- CN
- China
- Prior art keywords
- resistance
- operational amplifier
- signal
- transformer
- output
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/32—Circuits or arrangements for control or supervision between transmitter and receiver or between image input and image output device, e.g. between a still-image camera and its memory or between a still-image camera and a printer device
- H04N1/327—Initiating, continuing or ending a single-mode communication; Handshaking therefor
- H04N1/32704—Establishing a communication with one of a facsimile and another telecommunication apparatus sharing a single line
- H04N1/32706—Type of the other apparatus
- H04N1/3271—Telephone answering machine
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/32—Circuits or arrangements for control or supervision between transmitter and receiver or between image input and image output device, e.g. between a still-image camera and its memory or between a still-image camera and a printer device
- H04N1/327—Initiating, continuing or ending a single-mode communication; Handshaking therefor
- H04N1/32704—Establishing a communication with one of a facsimile and another telecommunication apparatus sharing a single line
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/32—Circuits or arrangements for control or supervision between transmitter and receiver or between image input and image output device, e.g. between a still-image camera and its memory or between a still-image camera and a printer device
- H04N1/327—Initiating, continuing or ending a single-mode communication; Handshaking therefor
- H04N1/32704—Establishing a communication with one of a facsimile and another telecommunication apparatus sharing a single line
- H04N1/32715—Detecting
- H04N1/32719—Detecting a facsimile calling signal, e.g. CNG
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Facsimiles In General (AREA)
- Telephonic Communication Services (AREA)
- Facsimile Transmission Control (AREA)
Abstract
A facsimile receiving circuit for a facsimile machine having a transmitter unit for transmitting a voice message signal and a receiver unit for receiving image data is described. A transformer T1 interfaces signals between a public telephone network and the transmitter and receiver units. A first operational amplifier 10 has a first input terminal connected via a first resistance R2 to the output Tx of the transmitter unit, a second input terminal connected to ground potential and an output terminal connected via a second resistance R3 to the said first input terminal, to amplify the voice message signal from the transmitter unit and supply the amplified signal to the transformer. A second operational amplifier 20 has a first input terminal connected to the said transformer via a third resistance R4 and a second input terminal connected via a voltage divider R6, R7 between the output terminal of the first amplifier 10 and ground potential, to amplifying the difference between the output signal from the transformer and the output of the first amplifier and supplying the amplified difference Rx to the receiving unit.
Description
Technical field
The present invention relates to a kind of receiving circuit of facsimile machine, more particularly, relate to a kind of facsimile receiving circuit that when speech information is replied in transmission automatically, improves detection of call sound ability.
Background technology
Recently, office automation (OA) equipment all needs to satisfy multi-functional requirement, and this shows that significantly trend is that the multipurpose product is more welcome than " single functional product " at present.At present the various facsimile machine products of selling have on the market all possessed multiple additional function, file copy function for example, with speech information automatically reply function and store the function etc. of speech information when receiving bell signal.
Referring to Fig. 1.General facsimile receiving circuit comprises: speech information transmitting element 50; Modulator-demodulator 60 is used for modulation; Transformer T1 receives from the plug tip end of public telephone network and the signal of plug ring end for conversion; Load resistance R1 connects one of them output of transformer T1; Switched circuit 30, the output and the modulator-demodulator 60 of the message of answering breath transmitting element 50 are to carry out switch operating; First resistance R 2 connects switched circuit 30; Second resistance R 3 is connected in series with first resistance R 2; First operational amplifier 10 (transmitting element operational amplifier), one input termination first and second resistance R 2, R3, its another input end grounding, thus export to load resistance R1 again after the output of above-mentioned speech information transmitting element 50 amplified; The 3rd resistance R 4 connects the connected node 5 of above-mentioned transformer T1 and load resistance R1; The 4th resistance R 5 is connected in series with the 3rd resistance R 4, second operational amplifier (receiving element operational amplifier), and one input termination the 3rd resistance R 4, its another input end grounding is exported away thereby input signal amplifies again; With inspection sound unit 40, its input connects the output of above-mentioned second operational amplifier 20, and its output connects the input of above-mentioned modulator-demodulator 60, thereby detects the calling tone (CNG) that above-mentioned second operational amplifier 20 sends.
When using above-mentioned inside that the facsimile machine of automatic answering phone is housed, detected bell signal when coming in, debit's the facsimile machine stored speech information of just resetting, send it to calling party, when calling party was wanted to send pictorial data, its facsimile machine just sent calling tone according to above-mentioned speech information to receiver.
At this moment, debit's facsimile machine detects the calling tone that calling party is sent, and just sends out speech information according to the bell signal of coming in, thereby changes the state of receiving faxes over to.
Like this, because the receiving element Rx of facsimile machine must receive CNG and speech information signal simultaneously, promptly speech information and CNG signal are input to inspection sound unit 40 at synchronization, thereby have reduced the calling tone detectability of inspection sound unit 40.
Summary of the invention
The purpose of this invention is to provide a kind of facsimile receiving circuit that improves the voice signal detectability, sort circuit only allows the CNG voice signal of public telephone network be input to receiving element Rx when receiving speech information signal and CNG signal at the same time, thereby speech information signal (being the output signal that transmitting element Tx sends) is stopped up.
Facsimile receiving circuit of the present invention comprises: transformer T1, and the input signal that comes for the above-mentioned public telephone network of conversion sends it to above-mentioned receiving element again; Load resistance R1, its input connects the output of above-mentioned transformer T1, thus the voltage of control load; First resistance R 2 and second resistance R 3, both are connected in series, and the speech information signal that above-mentioned speech information transmitting element Tx sends is promptly by resistance R 2 and R3; First operational amplifier 10, an one input connect the connected node 9 of above-mentioned first and second resistance R 2, R3 selectively, its another input end grounding, thus export to above-mentioned load resistance R1 after above-mentioned speech information signal amplified; With second operational amplifier 20, an one input divides two-way, one the tunnel connects the 4th resistance R 5, another Lu Jingdi three resistance R 4 meet above-mentioned transformer T1, its another input is through the 6th resistance R 7 ground connection, connect the output of above-mentioned first operational amplifier 10 simultaneously through the 5th resistance R 6, thereby send the calling tone signal that amplifies to above-mentioned receiving element Rx.
Description of drawings
Referring now to accompanying drawing, only is described more specifically content of the present invention with way of example.
Fig. 1 is the block diagram of prior art facsimile receiving circuit.
Fig. 2 is the detailed circuit diagram of facsimile receiving circuit of the present invention.
Embodiment
General facsimile receiving circuit shown in Figure 1 is that with the different of facsimile receiving circuit of the present invention shown in Figure 2 circuit of the present invention has been set up the 5th resistance R 6 between node 3 and node 7, has set up the 6th resistance R 7 between node 7 and ground terminal.
The output impedance of above-mentioned first operational amplifier, 10 outputs is zero because of the characteristic of operational amplifier itself.Therefore, this output can be considered ground connection (virtual earth).In addition, above-mentioned load resistance R1 can regard the resistance that connects two secondary terminals of transformer T1 as.Load resistance R1 can be considered the load resistance of transformer T1.The coil of transformer T1 is during by 1: 1 turn ratio coiling, and the AC impedance of primary side equals load resistance R1, thereby load resistance R1 is depended in this impedance.Usually, connect the terminal equipment of distribution panelboard, desirable 600 henries of its AC impedance.
Above-mentioned output signal Tx sends public telephone network to by transformer T1 after first operational amplifier 10 (i.e. the operational amplifier of Tx signal is amplified in gain) amplifies.Like this, the signal magnification factor of first operational amplifier 10 is Av=-(R3/R2), thereby V2 equals-(R3/R2) V
TX, wherein "-" number expression paraphase.
The signal value V3 that makes above-mentioned output signal Tx return to the output voltage V 3 of receiving element Rx is not only determined by R4 and R5, is also determined by R6 and R7.Therefore, if control these resistance values to such an extent that make R5/R4 equal R7/R6, the output voltage V 3 of then above-mentioned receiving element Rx is with respect to transmission voltage V
TXHas minimum value.
In other words, in sum, when circuit design of the present invention must make the value of the output signal Tx that turns back to receiving element reach minimum, can detect the receipts that send out to come in during the speech information signal from the CNG of public telephone network sound.In addition, the receipts of coming in are to utilize third and fourth resistance R 4, R5 amplifier from the signal of public telephone network, thereby can input to receiving element Rx and irrelevant with the 5th and the 6th resistance R 6, R7.
The present invention can improve the CNG voice signal detectability of facsimile receiving circuit greatly, this is because when transmission speech information signal carries out simultaneously with reception CNG signal, on the one hand avoid the speech information signal to transport in the receiving element as far as possible, will receive on the other hand to be amplified and reach from the CNG of public telephone network signal.
Claims (3)
1. the facsimile receiving circuit of the facsimile machine of automatic answering phone is equipped with in an inside, on the one hand in order to send the speech information signal by speech information transmitting element (Tx), on the other hand in order to when detecting the public telephone network calling tone signal that receiving element (Rx) receives, to receive pictorial data, it is characterized in that it comprises:
A transformer (T1), the signal for the conversion public telephone network is sent sends it to described receiving element (Rx) again;
A load resistance (R1), the output (5) of its input described transformer of termination (T1) is used for control load voltage;
First operational amplifier (10), for first resistance (R2) and second resistance (R3) of output signal that allows speech information transmitting element (Tx) send by being connected in series, an one input connects the connected node (9) of first resistance and second resistance selectively, its another input end grounding, thus described load resistance (R1) exported to after described output signal amplified; With
Second operational amplifier (20), an one input connects parallel simultaneously the 4th resistance (R5) that connects of described transformer (T1) through the 3rd resistance (R4), its another input is by the 6th resistance (R7) ground connection, and by connecing described first operational amplifier (10), so that send the calling tone of amplifying to receiving element (Rx) between the output of described first operational amplifier (10) and the 5th resistance (R6) between described the 6th resistance (R7).
2. the facsimile receiving circuit of facsimile machine according to claim 1, it is characterized in that described the 5th resistance (R6) and the 6th resistance (R7) are used for preventing that the described output signal by described first operational amplifier (10) amplification and transmission from turning back to described second operational amplifier (20).
3. the facsimile receiving circuit of facsimile machine as claimed in claim 1 or 2 is characterized in that described the 5th resistance (R6) and the 6th resistance (R7) make described second operational amplifier (20) press differential amplifier work.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR11476/96 | 1996-04-16 | ||
| KR1019960011476A KR0177100B1 (en) | 1996-04-16 | 1996-04-16 | Receiving circuit for facsimile |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1169634A CN1169634A (en) | 1998-01-07 |
| CN1096786C true CN1096786C (en) | 2002-12-18 |
Family
ID=19455842
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN97110557A Expired - Fee Related CN1096786C (en) | 1996-04-16 | 1997-04-16 | Facsimile receiving circuit |
Country Status (3)
| Country | Link |
|---|---|
| KR (1) | KR0177100B1 (en) |
| CN (1) | CN1096786C (en) |
| GB (1) | GB2312354B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59119968A (en) * | 1982-12-27 | 1984-07-11 | Hitachi Ltd | Facsimile device |
| GB2232324A (en) * | 1989-05-31 | 1990-12-05 | Samsung Electronics Co Ltd | Facsimile systems having telephone-answering function |
| EP0531217A2 (en) * | 1991-09-04 | 1993-03-10 | Canon Kabushiki Kaisha | Facsimile apparatus with automatic answering telephone function, and communication method in said apparatus |
| US5479499A (en) * | 1993-12-15 | 1995-12-26 | Murata Manufacturing Co., Ltd. | Sensor circuit for voice/fax switch with cascaded amplifier circuit |
| US5490210A (en) * | 1993-12-07 | 1996-02-06 | Sasso; Bill J. | Programmable telephone interface device |
-
1996
- 1996-04-16 KR KR1019960011476A patent/KR0177100B1/en not_active IP Right Cessation
-
1997
- 1997-04-16 GB GB9707710A patent/GB2312354B/en not_active Expired - Fee Related
- 1997-04-16 CN CN97110557A patent/CN1096786C/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59119968A (en) * | 1982-12-27 | 1984-07-11 | Hitachi Ltd | Facsimile device |
| GB2232324A (en) * | 1989-05-31 | 1990-12-05 | Samsung Electronics Co Ltd | Facsimile systems having telephone-answering function |
| EP0531217A2 (en) * | 1991-09-04 | 1993-03-10 | Canon Kabushiki Kaisha | Facsimile apparatus with automatic answering telephone function, and communication method in said apparatus |
| US5490210A (en) * | 1993-12-07 | 1996-02-06 | Sasso; Bill J. | Programmable telephone interface device |
| US5479499A (en) * | 1993-12-15 | 1995-12-26 | Murata Manufacturing Co., Ltd. | Sensor circuit for voice/fax switch with cascaded amplifier circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| KR970072927A (en) | 1997-11-07 |
| GB2312354A (en) | 1997-10-22 |
| CN1169634A (en) | 1998-01-07 |
| GB9707710D0 (en) | 1997-06-04 |
| KR0177100B1 (en) | 1999-05-01 |
| GB2312354B (en) | 1998-06-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| USRE39406E1 (en) | Telephone line coupler | |
| CN1030675C (en) | Power line communications terminal and interface circuit associated therewith | |
| JP2850126B2 (en) | Line interface circuit | |
| US5999619A (en) | Synthetic termination | |
| CN1025270C (en) | Line interface circuit | |
| CN1096786C (en) | Facsimile receiving circuit | |
| JPH0327141B2 (en) | ||
| US7577205B1 (en) | Return-loss compliant DSL modem line interface unit with complex termination | |
| EP0684748A2 (en) | Microphone/loudspeakers and systems using multiple microphone/loudspeakers | |
| US4358644A (en) | Bilateral current source for a multi-terminal intercom | |
| JP3061733B2 (en) | Simultaneous call intercom system | |
| JPS6230546B2 (en) | ||
| GB2345820A (en) | Reducing echo and side tones in a switching system | |
| JP2718209B2 (en) | Subscriber circuit | |
| US4178484A (en) | Long line telephone system with an amplifying substation | |
| KR940002151B1 (en) | Two line interphone circuit sharing power and signal | |
| KR910003391B1 (en) | Half duplex transceiver | |
| KR920011070B1 (en) | Side tone prevention circuit | |
| JP3463764B2 (en) | Key telephone terminal equipment | |
| JP2917028B2 (en) | Private branch exchange | |
| US20060029213A1 (en) | Communication arrangement and transmission unit for information transfer over a transmission and a circuit arrangement for connection to the transmission unit | |
| JPS5936466A (en) | Telephone transfer device | |
| US5642415A (en) | Modular attenuator | |
| JP3494468B2 (en) | Hybrid circuit and device using the same | |
| KR950004458Y1 (en) | Echo-cancellation circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C06 | Publication | ||
| PB01 | Publication | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20021218 |