CN201263185Y - Optical fiber access television set - Google Patents
Optical fiber access television set Download PDFInfo
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- CN201263185Y CN201263185Y CNU2008201496610U CN200820149661U CN201263185Y CN 201263185 Y CN201263185 Y CN 201263185Y CN U2008201496610 U CNU2008201496610 U CN U2008201496610U CN 200820149661 U CN200820149661 U CN 200820149661U CN 201263185 Y CN201263185 Y CN 201263185Y
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Abstract
The utility model discloses a fiber access television which comprises a TV high-frequency tuning circuit. An input terminal of the high-frequency tuning circuit is connected with an optical signal receiving module which comprises an optical/electrical converter, an attenuator and an amplifying circuit, wherein, the optical/electrical converter is connected with the attenuator; and the attenuator is connected with an equalizer which is then connected with the amplifying circuit. The fiber access television reserves a multi-channel signal interface and can realize reverse passback and access by appropriate configuration, which is applicable to the access configuration for such systems as a transmission technology of Ethernet over coax (EOC), an Ethernet passive optical network (EPON), etc. In addition, the fiber television can still keep the original RF interface to directly receive electric signals so as to meet the different demands of subscriber lines. Moreover, an optical channel and an RF channel in the television can be transformed with automatic recognition, simultaneously a passback circuit also can be added and a passback input interface can be arranged so as to realize the interaction of users.
Description
Technical field
The utility model belongs to a kind of television set, specifically relates to a kind of optical fiber access function that has, and is fit to the cable TV network of following full Optical Fiber Transmission, the new television models that the communication network TV signal inserts.
Background technology
In recent years, backbone network is progressively realized broadband and digitlization, yet the existing Access Network that is used for nearly all is cable system simulation, the arrowband, and it has become the obstacle of whole broadband communication network development.We can say there be not broadband the broadband of whole communication network of just being far from being of Access Network.Continuing to bring out along with new business in addition, the user is more and more higher to the bandwidth requirement of Access Network, thereby press for and widen existing bandwidth, anxious to be solved miscellaneous service, be sent to user's method as the first-class various data in plain old telephone, CATV program, digital video on demand and internet, promptly in the single demand that multiple business is provided on the net.The construction of optical fiber FSAN helps alleviating and overcomes bottleneck between users and the communication network.
Continuous development along with cable television system CATV transmission technology, hybrid fiber coax HFC advances with " light advances copper and moves back " at present, from optical fiber to the village, Fiber To The Curb, developed into FTTC, the Fiber-To-The-Building head, and gradually to fiber-to-the-subscriber, the direction transition of fiber to the desk estimates that next three years to five year will finish this transition.On the other hand, along with the G.657 standard birth of optical fiber of ITU-T, optical fiber has possessed very low macrobend loss on G.652D compatible comprehensively basis.Can be used in the limited building of distance, bending radius is the application scenario of 7.5mm and 10mm; Can be as copper cable is installed, install at optical cable very little turning in the building, permission is used for optical fiber in the less terminal box of volume, distributing cabinet and other line facility, simultaneously, optical fiber cold joint technology occurred, installing only needs to use passive construction tool, uses mechanical system with the direct Cheng Duan of optical fiber, the mechanical fiber optic connector can repeatedly repeat to open and use, and condition has been created in the FTTH fast development for Fiber to the home; The engineering cost of Fiber to the home FTTH will decline to a great extent for a year or two, even be lower than the cost that present building cable sets up.At present, broadcasting and TV, telecommunications, fiber-to-the-home EPON is all being greatly developed in the internet.And the appearance of optical fiber television will be again the course with " the copper matting advances " in a step walk to the end, realization FTTT, promptly optical fiber is to television set.
Summary of the invention
The purpose of this utility model provides a kind of optical fiber access function that has, and is fit to the cable TV network of following full Optical Fiber Transmission, the optical fiber access type television set that the communication network TV signal inserts.
For achieving the above object, the utility model is by the following technical solutions:
The utility model comprises the television set high-frequency tuning circuit, and the input of high-frequency tuning circuit is connected with optical signal receiving module; Optical signal receiving module comprises light/electric transducer, attenuator, equalizer and amplifying circuit, and wherein, light/electric transducer links to each other with attenuator, and attenuator is connected with equalizer, and equalizer links to each other with amplifying circuit.
Above-mentioned light/electric transducer is the PIN photodetector.
Also comprise match circuit in the optical signal receiving module, the input of match circuit is connected with the output of PIN photodetector, and the output of match circuit links to each other with attenuator.
Also comprise pre-amplification circuit in the above-mentioned optical signal receiving module, the input of pre-amplification circuit links to each other with the output of match circuit, and the output of pre-amplification circuit links to each other with attenuator.
Light/electric transducer is light/electric converter ic, comprises PIN photodetector, match circuit and pre-amplification circuit in light/electric converter ic.
Optical fiber access type television set also comprises radio frequency input circuit and commutation circuit, and described radio frequency input circuit all is connected with commutation circuit with optical signal receiving module.
Optical fiber access type television set also comprises cpu control circuit, and cpu control circuit is connected with attenuator, equalizer, commutation circuit respectively.
Optical fiber access type television set also comprises intelligent signal gain circuitry, slope adjustment circuit and intelligent automatic signal identification commutation circuit.
Optical fiber access type television set also comprises the passback optical signal receiving module, and described passback optical signal receiving module comprises optical transmission circuit and reverse electrical transmission circuit, and oppositely the output of electrical transmission circuit is connected with the input of optical transmission circuit; Comprise electric to optic converter in the optical transmission circuit, and electric to optic converter is a laser.
Adopt the utility model of technique scheme, reserved many signalling channels interface, suitably configuration just can oppositely return access function in fact, the convenient access configuration that adapts to the systems such as transmission technology EOC, Ethernet passive optical network EPON of ethernet coaxial cable.In addition, optical fiber television has also kept original RF interface, so that directly receive the signal of telecommunication, convenient so different subscriber's line needs.And optical channel and RF passage in the machine can be changed mutually, automatically identification.Simultaneously can also install feedback circuit additional, the transmission back incoming interface is set, following line output radio frequency interface can transmit other data, packed data, voice signal when receiving the simulated television digital television signal, realize the user interaction function.
Description of drawings
Fig. 1 is the theory diagram of the utility model embodiment 1;
Fig. 2 is the theory diagram of the utility model embodiment 2;
Fig. 3 is the theory diagram of the utility model embodiment 3;
Fig. 4 is the theory diagram of the utility model embodiment 4;
Fig. 5 is the theory diagram of the utility model embodiment 5;
Fig. 6 is the theory diagram of the utility model embodiment 6;
Fig. 7 is the theory diagram of the utility model embodiment 7;
Fig. 8 is the theory diagram of the utility model embodiment 8;
Fig. 9 is the theory diagram of the utility model embodiment 9;
Figure 10 is the theory diagram of the utility model embodiment 10;
Figure 11 is the theory diagram of the utility model embodiment 11;
Figure 12 is the theory diagram of the utility model embodiment 12;
Figure 13 is the theory diagram of the utility model embodiment 13;
Figure 14 is the theory diagram of the utility model embodiment 14;
Figure 15 is the theory diagram of the utility model embodiment 15;
Embodiment
As shown in Figure 1, present embodiment comprises the television set high-frequency tuning circuit, and the input of above-mentioned high-frequency tuning circuit is connected with optical signal receiving module; Optical signal receiving module comprises light/electric transducer, amplifying circuit AMP, attenuator ATT and equalizer EQ, and above-mentioned light/electric transducer is the PIN photodetector, adopts PIN photodiode, and significant feature is that light signal is become the signal of telecommunication.Wherein, the PIN photodetector links to each other with attenuator ATT, and attenuator ATT links to each other with equalizer EQ, and equalizer EQ is connected with amplifying circuit AMP.Its process mainly is: the comprehensive light signal of the CATV process PIN of the elder generation photodetector from optical interface inserts converts the CATV radiofrequency signal to.In the ideal case, this radiofrequency signal is not very faint, can directly pass through attenuator ATT, equalizer EQ and regulate the small-signal that obtains being fit to intensity and flatness, and then faint small-signal be amplified, send into the television set high-frequency tuning circuit through amplifying circuit AMP.Wherein the main effect of attenuator ATT is an intensity of adjusting signal, to be fit to the reasonable level that the high-frequency tuning circuit needs are imported in the television tuner; The effect of equalizer EQ is that the low-and high-frequency signal is carried out balance of power level.
Specifically, be directed to optical fiber interface, the switching of optical fiber is connected between joint and joint by flange, common connector has round belt screw thread and microballoon face grinding and polishing interface FC/PC, round belt screw thread and is 8 degree angles and is microballoon face grinding and polishing interface FC/APC, plug-in square interface SC, and above-mentioned connector is technology well known to those of ordinary skill in the art.
Light/electric transducer: mainly finish by the PIN photodetector.What the PIN photodetector adopted in the present embodiment is PIN photodiode.The PIN photodetector is a critical component in light/electric transducer, its effect is that the light signal that receives is changed into the signal of telecommunication, in the optical fiber television machine, the general requirement of the wavelength of PIN photodetector is 1100-1600nm, should satisfy some requires: very high response efficiency is arranged in the wavelength band of system works, promptly to the light signal of incident in the service band, the PIN photodetector can be exported bigger photoelectric current; Enough responsivenesses are arranged, and output current and input optical power are linear relationships, and be undistorted to guarantee signal; Noise is low, bandwidth, and the noise that the PIN photodetector is introduced in light-to-current inversion should be as far as possible little, because the incident optical signal of PIN photodetector is generally quite faint, is again the prime of Optical Receivers, and is bigger to the carrier-to-noise ratio influence of system; Therefore reliability height, long, stable performance of life-span can adapt to certain changes in environmental conditions such as temperature.In the present embodiment, the photodetector of selecting to use is a PIN photodiode, only needs the bias voltage of 10-20V to get final product work, and does not need bias voltage control.Receive when designing if passive optical network is a low optical power, photodetector can be selected the APD pipe for use.The APD pipe has 10～200 times internal current gain, the sensitivity that can improve Optical Receivers.But use APD pipe more complicated, need tens to 200V bias voltage, and variations in temperature more seriously influences the gain characteristic of APD pipe, so need usually control to keep its gain constant to the bias voltage of APD pipe.Basic demand to the PIN photodetector is high conversion efficiency, low additional noise and response fast.
Amplifying circuit AMP: because the photoelectric current that the PIN photodetector produces is very faint,, amplify signal, satisfy in the high-frequency tuning circuit of television set inside and handle so need to pass through amplifying circuit AMP usually in nA～μ A magnitude.
Attenuator ATT: in the specified frequency scope, a kind of in order to introduce the circuit of predetermined decay.Generally indicate with the decibels of introduced decay and the ohmage of characteristic impedance thereof.Attenuator generally is that big voltage signal is decayed to certain ratio multiple, is often referred to power attenuation, reaches safe or desirable level value, so that cooperate the requirement of next stage circuit to level.
Equalizer EQ: the effect of equalizer EQ is that the digital pulse signal to the distortion of TV station output carries out shaping, makes it to become to help most adjudicating and the raised cosine waveform of intersymbol interference minimum.The output signal of equalizer EQ is divided into two-way usually, and one the tunnel is transformed into and the proportional direct current signal of the peak value of input signal through peak-detector circuit, sends into automatic gain control circuit, in order to the gain of control main amplifying circuit; The judgement regenerative circuit is sent on another road, the raised cosine singal of equalizer output is reverted to the digital signal of " 0 " or " 1 ".In passive equalizer, balancing procedure come down to by to in the decay of low frequency signal realize.In the present embodiment, equalizer is for adopting SJ-B75 ohm 20dB adjustable attenuator, and its three face is with the sheet metal support, there is a copper rivet at its back side, for the attenuator internal interface is located in, i.e. and attenuator high frequency master ground, for widening frequency band, realize shunt-resonant circuit, available three loop simultaneously.In order to reduce distributed capacitance, the shunt-resonant circuit is connected on mid point, the high frequency ground in loop should be near the upper edge.
As shown in Figure 2, present embodiment comprises the television set high-frequency tuning circuit, and the input of above-mentioned high-frequency tuning circuit is connected with optical signal receiving module; Optical signal receiving module comprises light/electric transducer, match circuit, pre-amplification circuit AMP1, attenuator ATT, equalizer EQ and amplifying circuit AMP, wherein, the PIN photodetector is connected with match circuit, match circuit is connected with pre-amplification circuit AMP1, pre-amplification circuit AMP1 links to each other with attenuator ATT, attenuator ATT links to each other with equalizer EQ, and equalizer EQ is connected with amplifying circuit AMP.Its process mainly is: from the comprehensive light signal of the CATV of the optical interface access process PIN of elder generation photodetector, convert the CATV radiofrequency signal to, realize that by match circuit the PIN photodetector is connected with the impedance matching of lawnmower amplifying circuit AMP1 then, then enter pre-amplification circuit AMP1 and carry out a low noise amplification, pre-amplification circuit AMP1 is mainly used to the gain that provides high, and the output signal of photodetector is amplified to the level that is suitable for television set signal of telecommunication receiving circuit needs.Then signal is regulated the small-signal that obtains being fit to intensity and flatness through attenuator ATT, equalizer EQ and is sent into amplifying circuit AMP and amplify, and the radiofrequency signal after the amplification is sent in the high-frequency tuning circuit of television set inside and handled.
In the present embodiment, the photodetector of selecting to use is a PIN photodiode, only needs the bias voltage of 10-20V to get final product work, and does not need bias voltage control.Receive when designing if passive optical network is a low optical power, photodetector can be selected the APD pipe for use.The APD pipe has 10～200 times internal current gain, the sensitivity that can improve Optical Receivers.But use APD pipe more complicated, need tens to 200V bias voltage, and variations in temperature more seriously influences the gain characteristic of APD pipe, so need usually control to keep its gain constant to the bias voltage of APD pipe.Basic demand to the PIN photodetector is high conversion efficiency, low additional noise and response fast.
Be connected with pre-amplification circuit AMP1 behind the PIN photodetector, because the photoelectric current that photodetector produces is very faint, usually in nA～μ A magnitude, must carry out low noise through pre-amplification circuit AMP1 earlier and amplify, the quality of its performance is the principal element of the image definition of decision television set.The small-signal electric current that gets through the detection of PIN photodetector, after the load resistance of flowing through converted voltage signal to, AMP1 was amplified by pre-amplification circuit.But pre-amplification circuit AMP1 is when amplifying signal, also can introduce the Johnson noise of devices such as the thermal noise of the resistance of amplifying circuit own and transistor itself.In addition, the amplifying circuit AMP of back also can amplify the noise that preamplifier produces when signal is amplified together.The performance quality of preamplifier has crucial influence to the definition of television set.For this reason, preamplifier must be low noise, wide-band amplifier.On the device of pre-amplification circuit was selected, have several usually: first kind was the high-frequency microwave pipe, and second kind is the GaAs microwave device, the third is the high-frequency model that the professional module producer produces.The high-frequency microwave pipe uses 91A usually, 96TS, 951 grades use the single tube push-pull circuit or to pipe OTL circuit push-pull circuit, second kind of GaAs microwave device is maximum low noise amplifier spare, the especially releases of GaAs technology integrated amplifier of use in nearly 2 years, because this kind amplifier circuit has only very little peripheral former device, only realize during use that impedance matching gets final product, the good product consistency of production, stability is high, index also is optimized, but need do imitative Electrostatic Treatment.The third high-frequency model adopts the amplifier module of integrated encapsulation.This assembly is generally produced by specialized factory, and optical fiber television machine manufacturer is as long as this assembled of buying to complete machine, has saved the trouble of many debugging.Usually there are manufacturers such as NXP, Freescale, German PDI directly to supply.Consider low noise factor, preferred GaAs circuit amplifies configuration in the present embodiment.
In addition, the PIN photodetector need be connected with pre-amplification circuit AMP1 by match circuit, and match circuit realizes that the PIN photodetector is connected with the impedance matching of pre-amplification circuit AMP1.The connecting interface mode of PIN photodetector and preamplifier circuit AMP1 generally has three kinds: Low ESR connection, mutual impedance connection, high impedance connect.
1). the high impedance interface: the straightforward procedure that photoelectric current is changed into voltage is that the reverse bias photoelectric current is acted on the load resistance, be pre-amplification circuit AMP1 thereafter, under the lower situation of optical input power level ratio, in order to increase the carrier-to-noise ratio CNR of output, just need big load resistance, that is to say that to require the input impedance of pre-amplification circuit AMP1 higher, and such impedance design just is called the high impedance interface, and corresponding pre-amplification circuit is also referred to as high-impedance amplifier.Though the high impedance interface can promote carrier-to-noise ratio CNR, but reduced the modulated response bandwidth, thereby the design of high impedance interface will have a compromise optimal design between big bandwidth and high carrier-to-noise ratio CNR, the method of the high frequency response of general expansion high impedance design is to introduce voltage equalizer behind pre-amplification circuit, even frequency equilibrium is arranged, the design of high impedance resistor still has some problems, because load resistance is bigger, makes that the dynamic range of high impedance component design is not wide; In addition, high impedance design is subjected to the influence of nonlinear distortion, and when the optical input power level was higher, this influence was comparatively strong especially.In balance, high impedance connect have carrier-to-noise ratio, highly sensitive advantage, but bandwidth and dynamic range be affected, it is mainly used in the Optical Receivers that ultralow luminous power receives.
2). the Low ESR interface: in actual design when the load resistance of PIN photodetector is reduced to 75 ohm, this is commonly referred to the Low ESR Interface design, the Low ESR design can improve the linearity of Optical Receivers, make it that bigger bandwidth and dynamic range be arranged, but also increased noise level simultaneously, made that the complete machine carrier-to-noise ratio level of Optical Receivers is lower slightly.
3). mutual impedance interface: in practical mutual impedance design, removed the load resistance of high impedance design, and feedback is provided for the input of pre-amplification circuit by feedback resistance, the existing low noise of this design, big dynamic range is arranged again, can make circuit working on higher frequency by the effective capacitance that reduces the mutual impedance design simultaneously, the mutual impedance design has tangible advantage: (1) compare with high impedance design its dynamic range be improved significantly; (2) because the combined resistance of the input resistance of the pre-amplification circuit of mutual impedance design and feedback resistance is very little, this means that the time constant of detector is very little, seldom even do not need to carry out equilibrium usually at this; (3) compare with the Low ESR design, the mutual impedance design has obviously improved sensitivity and has promoted the carrier-to-noise ratio index, though the mutual impedance design is not so good as the high-impedance amplifier sensitivity, for the The Wide-Band Design of most of reality, this difference has only about 2dB usually.Because in fact the transmission characteristic parameter of the pre-amplification circuit of mutual impedance design is exactly its mutual impedance, feedback resistance just, therefore, transimpedance amplifier is easy to control, and highly stable.In a word mutual impedance connect have the carrier-to-noise ratio height, the advantage of highly sensitive, bandwidth.
In the present embodiment, PIN photodetector, match circuit and pre-amplification circuit AMP1 adopt resolution element to make.At this moment, match circuit adopts a ferrite high-frequency coupler to realize broadband Low ESR coupling.The low noise pre-amplification circuit AMP1 of back adopts one, two or the four power amplification triodes of merely hitting to recommend amplification or changes the silicon technology triode into GaAs GaAs chip, GaAs technology amplifies the introducing that can reduce noise, obtain desirable noise factor, be particularly suitable for doing the low noise amplification of assembly.It has favorable linearity index and non-linear index, but is subjected to the impact failure of static easily, needs the accentuator protection.The silicone tube noise factor is higher, and is linear, the nonlinear distortion index is poor than GaAs technology, but it has stronger carrying load ability and impact resistance.
The other technologies feature is identical with embodiment 1.
Embodiment 3
As shown in Figure 3, present embodiment comprises the television set high-frequency tuning circuit, and the input of above-mentioned high-frequency tuning circuit is connected with optical signal receiving module; Optical signal receiving module comprises light/electric transducer, attenuator ATT, equalizer EQ and amplifying circuit AMP, above-mentioned light/electric transducer is light/electric converter ic, in its light/electric converter ic PIN photodetector, match circuit and pre-amplification circuit AMP1 is packaged together.Above-mentioned light/electric converter ic is a technology well known to those of ordinary skill in the art.Wherein, light/electric converter ic links to each other with attenuator ATT, and attenuator ATT links to each other with equalizer EQ, and equalizer EQ is connected with amplifying circuit AMP.Its process mainly is: from the comprehensive light signal of CATV elder generation process light/electric converter ic that optical interface inserts, convert the CATV radiofrequency signal to, and carry out a low noise by its inner pre-amplification circuit AMP1 and amplify, regulate the small-signal that obtains being fit to intensity and flatness through attenuator ATT, equalizer EQ then and send into amplifying circuit AMP and amplify, the radiofrequency signal after the amplification is sent in the high-frequency tuning circuit and is handled.
In the present embodiment, PIN photodetector, match circuit and pre-amplification circuit AMP1 adopt integrated encapsulating structure.Promptly adopt the standard base encapsulation, supply power voltage adopts common voltage 24V.The assembly of this kind structure is compared remarkable advantage with the assembly of resolution element: the design of integrated Optical Receivers is perfect, plug and play, high conformity, single element are saved the space, must do not done extra debugging.Silicon technology tube core or GaAs technology die making are adopted in the main flow design of pre-amplification circuit AMP1 in this kind assembly usually, and circuit structure adopts recommends amplification.Adopt the assembly noise factor of GaAs technology die making to be 5dB to the maximum, and adopt the assembly maximum noise coefficient of silicon technology tube core production can reach 11dB, usually more than 8dB.The integrated assembly of this kind is representative with the product of NXP company.Concrete circuit structure has following several: (1) thick film resolution element technology; The element that this assembly adopts adopts integrated encapsulation on the basis of separation member, reduced the influence of circuit discrete parameter, and the overall objective score is better from element; (2) triode core technique component, this kind assembly adopt triode core to make, and have dwindled encapsulation volume greatly, and heat dispersion is also strengthened.Equally, the assembly of this kind structure also is divided into two kinds of silicon technology and GaAs technologies; (3) GaAs processing chip assembly, the preamplifier of this kind film piece adopt the broadband of GaAs technology to amplify chip manufacturing, and gain is generally between 12-18dB.
In addition, in the present embodiment, attenuator ATT adopts passive attenuator.In addition, can adopt the active attenuator composition variable attenuator that matches with other temperature-sensitive elements, device is used for automatic gain or slope control circuit, can also adopts numerical-control attenuator, voltage-controlled attenuator etc. multiple in amplifying circuit.Passive attenuator has fixed attenuator and adjustable attenuator.Fixed attenuator is made up of resistance, does not influence frequency characteristic, and T type commonly used or pin network are formed; Adjustable attenuator is made up of in debugging potentiometer and level uses in adjusting.Requiring input, the output impedance of attenuator to mate with interface end, is 75 Europe.The frequency characteristic of attenuator will satisfy the frequency range requirement of system, the attenuation of attenuator and frequency-independent in frequency range.Therefore, resistive element commonly used is formed.Frequency range difference, the form of attenuator are also different.The employing solid-state diode is also arranged, as PIN diode in microwave frequency band, make waveguide or coaxial line system can electric tuning attenuator.In order to realize that the Gain Adjustable joint has used numerical-control attenuator; In order to realize that power output controls automatically, used voltage-controlled attenuator.
The other technologies scheme is identical with embodiment 1.
As shown in Figure 4, different is for present embodiment and embodiment 1, and present embodiment also comprises radio frequency input circuit and commutation circuit on the basis of embodiment 1 technical scheme, and the radio frequency input circuit all is connected with commutation circuit with optical signal receiving module.Above-mentioned radio frequency input circuit is the radio frequency input circuit in the original conventional television, is the known technology of ordinary skill.According to the difference in signal source, specifically light signal or radiofrequency signal, thus select different input modes, again by commutation circuit, selected signal is sent in the high-frequency tuning circuit.Above-mentioned commutation circuit is a technology well known to those of ordinary skill in the art.
The other technologies feature is identical with embodiment 1.
Embodiment 5
As shown in Figure 5, different is for present embodiment and embodiment 2, and present embodiment also comprises radio frequency input circuit and commutation circuit on the basis of embodiment 2 technical schemes, and the radio frequency input circuit all is connected with commutation circuit with optical signal receiving module.Above-mentioned radio frequency input circuit is the radio frequency input circuit in the original conventional television, is the known technology of ordinary skill.According to the difference in signal source, specifically light signal or radiofrequency signal, thus select different input modes, again by commutation circuit, selected signal is sent in the high-frequency tuning circuit.Above-mentioned commutation circuit is a technology well known to those of ordinary skill in the art.
The other technologies feature is identical with embodiment 2.
Embodiment 6
As shown in Figure 6, different is for present embodiment and embodiment 3, and present embodiment also comprises radio frequency input circuit and commutation circuit on the basis of embodiment 3 technical schemes, and the radio frequency input circuit all is connected with commutation circuit with optical signal receiving module.Above-mentioned radio frequency input circuit is the radio frequency input circuit in the original conventional television, is the known technology of ordinary skill.According to the difference in signal source, specifically light signal or radiofrequency signal, thus select different input modes, again by commutation circuit, selected signal is sent in the high-frequency tuning circuit.Above-mentioned commutation circuit is a technology well known to those of ordinary skill in the art.
The other technologies feature is identical with embodiment 3.
Embodiment 7
As shown in Figure 7, present embodiment has also comprised cpu control circuit as different from Example 4 in the present embodiment.Above-mentioned cpu control circuit is increase light signal strength sampling on the basis of original TV CPU, ATT sampling, EQ sampling, up ATT sampling, also corresponding adjustment instruction is sent in response, and the apparent instruction of screen.Because the new television set that produces was bus control circuit in nearly 2 years, the manufacturer gets up very convenient to these function increases.
Cpu control circuit is connected with attenuator, equalizer, commutation circuit respectively.The video screen show state, simultaneously by the remote controller firing operation, receive by shaking the control receiving circuit, finger is shaken in the control instruction input cpu control circuit, thereby adjust attenuator ATT, the value of equalizer EQ, thus obtain the signal quality that needs, simultaneously, the screen that is connected with cpu control circuit shows circuit and show the adjustment state on screen.Above-mentioned utilize remote controller emission and receiving circuit are technology well known to those of ordinary skill in the art.
Because in the application of reality, in order to realize the detection to input optical power, light/electric transducer generally all is added with the luminous power detection cell circuit, its essence is that the received current with the PIN photodetector converts voltage to, output to a pin, use for the luminous power display circuit.Because the received current of PIN photo-detector is directly proportional with input optical power, therefore by reasonably coupling setting, the light-receiving electric current just can accurately show the value of input optical power.The luminous power of general product shows that numeric reference is 1V/1mW, promptly when detection voltage is 1V, the input optical power that be described this moment is 1mW, is higher than 1V or is lower than 1V if detect voltage, and input optical power will be followed the variation of voltage in proportion, in the practicability product, the product that has adopts the diode displaying input optical power, and each light-emitting diode is represented the Output optical power of different shelves, and this demonstration is rough demonstration, estimate during for practical application, and inaccuracy.Because adopt comparator detection and driven for emitting lights two extremely luminous, error is bigger, but also satisfies instructions for use.Another kind of luminous power is shown as charactron or liquid crystal display, and unit is mW, and the product unit of display that also has is dBm, its display precision is 0.01mW, this demonstration can be followed the variation of input optical power accurately, its show value be very accurate comparatively speaking and the light power meter measured value very nearly the same.For user's convenience, in this value input television set cpu control circuit, pass through I
2The total line traffic control control of C is presented on the television screen by the control of TV remote controller.Adjust the size of optical input power simultaneously by remote controller.Pass through I
2The total line traffic control of C, can be on video screen the size of display light received power, and remove to regulate the height of the signal of telecommunication to be fit to the actual demand of television reception by remote controller.In addition, can also select reverse whether opening and the adjusting of various additional functions by remote controller.
The other technologies feature is identical with embodiment 4.
Embodiment 8
As shown in Figure 8, present embodiment has also comprised cpu control circuit as different from Example 5 in the present embodiment, and cpu control circuit is connected with attenuator, equalizer, commutation circuit respectively.The video screen show state, simultaneously by the remote controller firing operation, receive by shaking the control receiving circuit, finger is shaken in the control instruction input cpu control circuit, thereby adjust attenuator ATT, the value of equalizer EQ, thus obtain the signal quality that needs, simultaneously, the screen that is connected with cpu control circuit shows circuit and show the adjustment state on screen.Above-mentioned utilize remote controller emission and receiving circuit are technology well known to those of ordinary skill in the art.
The other technologies feature is identical with embodiment 5.
Embodiment 9
As shown in Figure 9, present embodiment has also comprised cpu control circuit as different from Example 6 in the present embodiment, and cpu control circuit is connected with attenuator, equalizer, commutation circuit respectively.The video screen show state, simultaneously by the remote controller firing operation, receive by shaking the control receiving circuit, finger is shaken in the control instruction input cpu control circuit, thereby adjust attenuator ATT, the value of equalizer EQ, thus obtain the signal quality that needs, simultaneously, the screen that is connected with cpu control circuit shows circuit and show the adjustment state on screen.Above-mentioned utilize remote controller emission and receiving circuit are technology well known to those of ordinary skill in the art.
The other technologies feature is identical with embodiment 6.
As shown in figure 10, present embodiment also comprises intelligent signal gain circuitry, slope adjustment circuit and intelligent automatic signal identification commutation circuit as different from Example 7 in the present embodiment.The small-signal that the prop BR of branch end branches out transfers to cpu control circuit, this is a sample circuit, logical CPU inside compares analysis, and sending to attenuator ATT, equalizer EQ, interface circuit of instruction as the indication of figure dotted line carried out descending gain adjustment, slope adjustment, the adjustment of photoelectricity path switching backward gain respectively.Above-mentioned intelligent signal gain circuitry, slope adjustment circuit and intelligent automatic signal identification commutation circuit are technology well known to those of ordinary skill in the art.Signal with the signal branch output point feeds back to cpu control circuit through the splitter bifurcations, after comparing with cpu control circuit internal reference voltage, the flat control of output DC attenuator ATT, equalizer EQ, the value of regulated attenuator ATT equalizer EQ, thereby the signal level value of adjusting port OUT.At the photosignal source of interface circuit inside automatic switch-over circuit, when the light signal input had program, K was connected to K-1, and the optical path signal path is connected, and sends into the radio frequency output; When light signal disappeared, K connected K-2, and pathway for electrical signals is connected, and enters high-frequency circuit.The state turnover of switch is controlled by cpu control circuit.
The other technologies feature is identical with embodiment 7.
As shown in figure 11, present embodiment also comprises intelligent signal gain circuitry, slope adjustment circuit and intelligent automatic signal identification commutation circuit as different from Example 8 in the present embodiment.Above-mentioned intelligent signal gain circuitry, slope adjustment circuit and intelligent automatic signal identification commutation circuit are technology well known to those of ordinary skill in the art.Signal with the signal branch output point feeds back to cpu control circuit through the splitter bifurcations, after comparing with cpu control circuit internal reference voltage, the flat control of output DC attenuator ATT, equalizer EQ, the value of regulated attenuator ATT, equalizer EQ, thereby the signal level value of adjusting port OUT.At the photosignal source of interface circuit inside automatic switch-over circuit, when the light signal input had program, K was connected to K-1, and the optical path signal path is connected, and sends into the radio frequency output; When light signal disappeared, K connected K-2, and pathway for electrical signals is connected, and enters high-frequency circuit.The state turnover of switch is controlled by cpu control circuit.
The other technologies feature is identical with embodiment 8.
Embodiment 12
As shown in figure 12, present embodiment also comprises intelligent signal gain circuitry, slope adjustment circuit and intelligent automatic signal identification commutation circuit as different from Example 9 in the present embodiment.Above-mentioned intelligent signal gain circuitry, slope adjustment circuit and intelligent automatic signal identification commutation circuit are technology well known to those of ordinary skill in the art.Signal with the signal branch output point feeds back to cpu control circuit through the splitter bifurcations, after comparing with cpu control circuit internal reference voltage, the flat control of output DC attenuator ATT, equalizer EQ, the value of regulated attenuator ATT, equalizer EQ, thereby the signal level value of adjusting port OUT.At the photosignal source of interface circuit inside automatic switch-over circuit, when the light signal input had program, K was connected to K-1, and the optical path signal path is connected, and sends into the radio frequency output; When light signal disappeared, K connected K-2, and pathway for electrical signals is connected, and enters high-frequency circuit.The state turnover of switch is controlled by cpu control circuit.
The other technologies feature is identical with embodiment 9.
Embodiment 13
As shown in figure 13, present embodiment as different from Example 10, also comprise passback light signal transmitter module in the present embodiment, above-mentioned passback light signal transmitter module comprises reverse signal of telecommunication transmission circuit and backlight radiating circuit, and oppositely the output of electrical transmission circuit is connected with the input of backlight radiating circuit.Comprise electric to optic converter in the optical transmission circuit, and the main devices of electric to optic converter is PF laser or PDF laser.Above-mentioned PF laser or PDF laser are technology well known to those of ordinary skill in the art.The high/low bandpass filter of reverse return path signal process by television set terminal PUT1, PUT2 input, enter the reverse transfer circuit, at first enter attenuator II ATT2, the level of signal is carried out suitable adjustment, carrying out signal through amplifier II AMP2 again amplifies, the return path signal that amplifies is sent into reverse laser PF, changes into light signal by returning optical interface to Network Transmission.The common height Tonghua of low pass filter is divided into: high frequency channel: 87---1000MHz; Low frequency channel: 5---65MHz.Also can use configuration simultaneously: high pass: 45---1000MHz according to reality; Low frequency channel: 5-30MHz.In addition, television set terminal PUT1, PUT2 can also receive and export descending non-TV signal to other equipment, all can easily insert as EOC, EPON terminal.
The other technologies feature is identical with embodiment 10.
Embodiment 14
As shown in figure 14, present embodiment as different from Example 11, also comprise passback light signal transmitter module in the present embodiment, above-mentioned passback light signal transmitter module comprises reverse signal of telecommunication transmission circuit and backlight radiating circuit, and oppositely the output of electrical transmission circuit is connected with the input of backlight radiating circuit.Comprise electric to optic converter in the optical transmission circuit, and the main devices of electric to optic converter is PF laser or PDF laser.Above-mentioned PF laser or PDF laser are technology well known to those of ordinary skill in the art.The high/low bandpass filter of reverse return path signal process by television set terminal PUT1, PUT2 input, enter the reverse transfer circuit, at first enter attenuator II ATT2, the level of signal is carried out suitable adjustment, carrying out signal through amplifier II AMP2 again amplifies, the return path signal that amplifies is sent into reverse laser PF, changes into light signal by returning optical interface to Network Transmission.The common height Tonghua of low pass filter is divided into: high frequency channel: 87---1000MHz; Low frequency channel: 5---65MHz.Also can use configuration simultaneously: high pass: 45---1000MHz according to reality; Low frequency channel: 5-30MHz.In addition, television set terminal PUT1, PUT2 can also receive and export descending non-TV signal to other equipment, all can easily insert as EOC, EPON terminal.
The other technologies feature is identical with embodiment 11.
Embodiment 15
As shown in figure 15, present embodiment as different from Example 12, also comprise passback light signal transmitter module in the present embodiment, above-mentioned passback light signal transmitter module comprises reverse signal of telecommunication transmission circuit and backlight radiating circuit, and oppositely the output of electrical transmission circuit is connected with the input of backlight radiating circuit.Comprise electric to optic converter in the optical transmission circuit, and the main devices of electric to optic converter is PF laser or PDF laser.Above-mentioned PF laser or PDF laser are technology well known to those of ordinary skill in the art.The high/low bandpass filter of reverse return path signal process by television set terminal PUT1, PUT2 input, enter the reverse transfer circuit, at first enter attenuator II ATT2, the level of signal is carried out suitable adjustment, carrying out signal through amplifier II AMP2 again amplifies, the return path signal that amplifies is sent into reverse laser PF, changes into light signal by returning optical interface to Network Transmission.The common height Tonghua of low pass filter is divided into: high frequency channel: 87---1000MHz; Low frequency channel: 5---65MHz.Also can use configuration simultaneously: high pass: 45---1000MHz according to reality; Low frequency channel: 5-30MHz.In addition, television set terminal PUT1, PUT2 can also receive and export descending non-TV signal to other equipment, all can easily insert as EOC, EPON terminal.
The other technologies feature is identical with embodiment 12.
Embodiment 16
Present embodiment as different from Example 13, increase the reverse passback signal of telecommunication in the present embodiment and adjusted function automatically, the reverse return path signal of television set terminal PUT1, the input of PUT2 port is through bandpass filtering ripple device, enter reverse return path, the signal of telecommunication in the backward channel is delivered to cpu control circuit in the BR port output sampling of the passback device B2 of forehearth limb, through the cpu control circuit comparative analysis, send and adjust instruction, export the attenuation size of different voltage signal control attenuator II ATT2, thus the intensity of the control passback signal of telecommunication.The return path signal that signal is fit to is sent into reverse laser PF then, changes into light signal and transfers to the uplink optical fibers Network Transmission by the passback optical interface.
The other technologies feature is identical with embodiment 13.
Embodiment 17
Present embodiment as different from Example 14, increase the reverse passback signal of telecommunication in the present embodiment and adjusted function automatically, the reverse return path signal of television set terminal PUT1, the input of PUT2 port is through bandpass filtering ripple device, enter reverse return path, the signal of telecommunication in the backward channel is delivered to cpu control circuit in the BR port output sampling of the passback device B2 of forehearth limb, through the cpu control circuit comparative analysis, send and adjust instruction, export the attenuation size of different voltage signal control attenuator II ATT2, thus the intensity of the control passback signal of telecommunication.The return path signal that signal is fit to is sent into reverse laser PF then, changes into light signal and transfers to the uplink optical fibers Network Transmission by the passback optical interface.
The other technologies feature is identical with embodiment 14.
Embodiment 18
Present embodiment as different from Example 15, increase the reverse passback signal of telecommunication in the present embodiment and adjusted function automatically, the reverse return path signal of television set terminal PUT1, the input of PUT2 port is through bandpass filtering ripple device, enter reverse return path, the signal of telecommunication in the backward channel is delivered to cpu control circuit in the BR port output sampling of the passback device B2 of forehearth limb, through the cpu control circuit comparative analysis, send and adjust instruction, export the attenuation size of different voltage signal control attenuator II ATT2, thus the intensity of the control passback signal of telecommunication.The return path signal that signal is fit to is sent into reverse laser PF then, changes into light signal and transfers to the uplink optical fibers Network Transmission by the passback optical interface.
The other technologies feature is identical with embodiment 15.
Claims (9)
1, a kind of optical fiber access type television set, it comprises the television set high-frequency tuning circuit, it is characterized in that: the input of described high-frequency tuning circuit is connected with optical signal receiving module; Described optical signal receiving module comprises light/electric transducer, attenuator, equalizer and amplifying circuit, and wherein, light/electric transducer links to each other with attenuator, and attenuator is connected with equalizer, and equalizer links to each other with amplifying circuit.
2, optical fiber access type television set according to claim 1, it is characterized in that: described light/electric transducer is the PIN photodetector.
3, optical fiber access type television set according to claim 1 and 2, it is characterized in that: also comprise match circuit in the described optical signal receiving module, the input of match circuit is connected with the output of PIN photodetector, and the output of match circuit links to each other with attenuator.
4, optical fiber access type television set according to claim 3, it is characterized in that: also comprise pre-amplification circuit in the described optical signal receiving module, the input of pre-amplification circuit links to each other with the output of match circuit, and the output of pre-amplification circuit links to each other with attenuator.
5, optical fiber access type television set according to claim 1, it is characterized in that: described light/electric transducer is light/electric converter ic, comprises PIN photodetector, match circuit and pre-amplification circuit in light/electric converter ic.
6, according to claim 1 or 4 or 5 described optical fiber access type television sets, it is characterized in that: described optical fiber access type television set also comprises radio frequency input circuit and commutation circuit, and described radio frequency input circuit all is connected with commutation circuit with optical signal receiving module.
7, optical fiber access type television set according to claim 6 is characterized in that: described optical fiber access type television set also comprises cpu control circuit, and cpu control circuit is connected with attenuator, equalizer, commutation circuit respectively.
8, optical fiber access type television set according to claim 6 is characterized in that: described optical fiber access type television set also comprises intelligent signal gain circuitry, slope adjustment circuit and intelligent automatic signal identification commutation circuit.
9, according to claim 7 or 8 described optical fiber access type television sets, it is characterized in that: described optical fiber access type television set also comprises the passback optical signal receiving module, described passback optical signal receiving module comprises optical transmission circuit and reverse electrical transmission circuit, and oppositely the output of electrical transmission circuit is connected with the input of optical transmission circuit; Comprise electric to optic converter in the optical transmission circuit, and electric to optic converter is a laser.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201496610U CN201263185Y (en) | 2008-10-09 | 2008-10-09 | Optical fiber access television set |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201496610U CN201263185Y (en) | 2008-10-09 | 2008-10-09 | Optical fiber access television set |
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|---|---|
| CN201263185Y true CN201263185Y (en) | 2009-06-24 |
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| CNU2008201496610U Expired - Fee Related CN201263185Y (en) | 2008-10-09 | 2008-10-09 | Optical fiber access television set |
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| CN (1) | CN201263185Y (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104301583A (en) * | 2013-07-19 | 2015-01-21 | 深圳市同洲电子股份有限公司 | Automatic loop-out signal adjusting method and system |
| CN104902307A (en) * | 2015-07-03 | 2015-09-09 | 成都怡云科技有限公司 | Multi-interface practical smart set top box for hotel |
| CN114172577A (en) * | 2022-02-12 | 2022-03-11 | 南昌大学 | Indoor visible light communication system under optical fiber fusion |
-
2008
- 2008-10-09 CN CNU2008201496610U patent/CN201263185Y/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104301583A (en) * | 2013-07-19 | 2015-01-21 | 深圳市同洲电子股份有限公司 | Automatic loop-out signal adjusting method and system |
| CN104902307A (en) * | 2015-07-03 | 2015-09-09 | 成都怡云科技有限公司 | Multi-interface practical smart set top box for hotel |
| CN114172577A (en) * | 2022-02-12 | 2022-03-11 | 南昌大学 | Indoor visible light communication system under optical fiber fusion |
| CN114172577B (en) * | 2022-02-12 | 2022-05-10 | 南昌大学 | Indoor visible light communication system under optical fiber fusion |
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