CN103477622B - Signal of video signal multiplex transmission apparatus and the camera head possessing it - Google Patents

Signal of video signal multiplex transmission apparatus and the camera head possessing it Download PDF

Info

Publication number
CN103477622B
CN103477622B CN201280017804.1A CN201280017804A CN103477622B CN 103477622 B CN103477622 B CN 103477622B CN 201280017804 A CN201280017804 A CN 201280017804A CN 103477622 B CN103477622 B CN 103477622B
Authority
CN
China
Prior art keywords
signal
resistance
mentioned
switch
waveform
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.)
Active
Application number
CN201280017804.1A
Other languages
Chinese (zh)
Other versions
CN103477622A (en
Inventor
鸟居忠义
中村和彦
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Kokusai Electric Inc
Original Assignee
Hitachi Kokusai Electric Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Kokusai Electric Inc filed Critical Hitachi Kokusai Electric Inc
Publication of CN103477622A publication Critical patent/CN103477622A/en
Application granted granted Critical
Publication of CN103477622B publication Critical patent/CN103477622B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/222—Studio circuitry; Studio devices; Studio equipment

Abstract

Improve the transmitted waveform during cable length prolongation of signal of video signal multiplexing digital transmission system.Digital image signal is carried out by the transmission path of 75 Ω in the multiplex transmission apparatus of time-division two-way switching transmitting-receiving, end in transmission both sides, path has the NMOS bus switch IC carrying out time-division two-way switching, receiving side, there is waveform equalizer or the receptor comprising waveform equalizer, the positive supply (Vcc) of NMOS bus switch IC is set to+3.3V, negative supply (Vee) is set to-1.7V, the 75-7=68 Ω having deducted the meansigma methods 7 Ω gained of the conducting resistance of NMOS bus switch IC is set to end resistance value (Rz).And then, there is the low Schottky-barrier diode to the ground connection that signal waveform polarity is compressed of conducting resistance of simulation switch and being connected in series of resistance.

Description

Signal of video signal multiplex transmission apparatus and the camera head possessing it
Technical field
The present invention relates to a kind of signal of video signal multiplex transmission apparatus used in the camera heads such as camera system The improvement of transmission method.
Background technology
In the past, in camera chain, by the transmission path of coaxial (Triple Axis) cable of three cores in shooting Between head and camera control unit, transmission main line signal of video signal, loopback signal of video signal, acoustical signal, control serial number it is believed that Number, power supply.As straightforward procedure, the most also use common coaxial cable.Generally, these signals are carried out Frequency modulation(PFM) carries out frequency multiplex transmission or digitally carries out time division multiplexing (two-way switching) transmission.
For main signal of video signal, there is NTSC and effective scanning line 575 line of effective scanning line 485 line as SDTV PAL, there is effective scanning line 720 line and effective scanning line 1080 line as HDTV, there is effective scanning line as SHDTV , there is effective scanning line 4320 line as UHDTV in 2160 lines.
From image pickup part output NTSC 10 bit 4:2:2 comprise digitized signal of video signal, acoustical signal, control letter Number image serial digital interface (SDI) the signal data volume of 270Mbps that has output amplitude to be 0.8Vp-p, the image of loopback Even if signal carries out data compression also the data volume of about 50Mbps.In the case of time-division transmitted in both directions, signal of video signal is entered Row Time Compression, becomes to be about the signal of 360Mbps and carrys out the short time and be transmitted to camera control unit from photographic head off and on. It addition, in the period of the free time due to Time Compression, pass off and on to the direction short time of photographic head from camera control unit The defeated signal of video signal being compressed by time the loopback into 360Mbps.By input and output switch with 1 second speed for several times to this Process switches over, and realizes time division multiplexing (two-way switching) transmission (patent documentation 1).The SDI(HD-SDI of HDTV) Signal has the data volume of 1500Mbps.The sdi signal of 3G has the data volume of 2970Mbps.The sdi signal of UHDTV has about The data volume of 24000Mbps.
The regeneration of impulse waveform is referred to as wave shape equalization.The 300MHz of the triple-concentric cable of general diameter 8.6mm declines Decrement is 12dB when 100m, arrives greatly 120dB during 1km, in the waveform equalizer of present market sale, for diameter 8.6mm Triple-concentric cable, about about 500m can only be extended between photographic head and camera control unit.Relayed by insertion When cable extends, it is necessary to the deterioration to the cable frequencies characteristic of digital image signal in advance according to the reference signal transmitted It is modified.Also proposed coaxial overlapping (the reference non-patent literature of the supervision purposes of overlapping power supply in SDI signal of video signal 1).
For sdi signal, commonly used reversal amplifier in analog signal processing circuit, the most troublesome it is intended to all the time The polarity of attention.Therefore, by using based on G(x)=(x9+x4+ 1) the motor synchronizing type of (x+1) such generator polynomial Scrambler (Non Return To Zero: non-return-to-zero) NRZ-I code, is replaced into the reversion letter of 0 → 1,1 → 0 by the 0/1 of data Breath, realizes polarity not by the restriction equally distributed sdi signal of frequency spectrum.If applying such motor synchronizing type scrambler, then at string Row transmission path on, on 1 horizontal line, sometimes produce 1 bit 1 followed by 19 bits 0 pattern (or its reversion Pattern) signal, or the signal of the pattern (or its reversing mode) of the 0 of continuous 20 bits after the 1 of continuous 20 bits.These Pattern is referred to as morbid state pattern (pathological pattern).Therefore, if according to morbid state pattern greatest length 20, The fundamental clock frequency 1/20 of sdi signal transmits the order harmonic frequencies of 3 times, then can inerrably transmit sdi signal (with reference to non- Patent documentation 2).HD-SDI signal is too.
As impedance deviation cable resistance 75 Ω of transtation mission circuit and reception circuit, producing bounce transmission mistake increases.For Sdi signal is carried out long-distance cable transmission, it is generally desirable in the frequency needed, make transtation mission circuit as far as possible and receive circuit Impedance consistent with cable resistance 750 Ω (with reference to non-patent literature 2).
Even if by transmission coaxial-cable length is improved to from 100m in the sdi signal of the 3G of 2970Mbps receives The waveform equalizer of 200m carries out wave shape equalization, and in the sdi signal of 270Mbps receives, transmission coaxial-cable length is also only It is somewhat to be extended for 400m(from 350m with reference to non-patent literature 3 and non-patent literature 4).Comprising the receptor of waveform equalizer In, in the sdi signal of 270Mbps receives, transmission coaxial-cable length is also simply somewhat extended for 480m(with reference to non-patent literary composition Offer 5).
Operating amplifier with current feedback (Operational Amplifier:Op Amp) under the little amplitude of 0.2Vp-p, If amplification is 1 times (0dB), then can amplify the high frequency within about 1.8GHz, if amplification is 2 times (+6dB), Then can amplify the high frequency within about 1.2GHz, if the big amplitude of 2Vp-p, then within can amplifying about 750MHz High frequency, the most also has shutdown (SD:shut down) function (with reference to non-patent literature 6).
But, the emitter stage amplifying transistor within operating amplifier with current feedback is connected with negative input terminal, if Radio-frequency component is not resistance components, then the connection impedance of negative input terminal causes vibration the most in high frequency.Therefore, electric capacity is passed through By the negative input terminal ground connection of operating amplifier with current feedback, it is difficult to realize amplifying the amplifying circuit of radio-frequency component.
But, recently in order to reduce unnecessary radiation, it is low when low frequency that each company has produced in batches with multiple kinds Impedance, starts impedance from characteristic frequency and drastically raises, the ferrite bead that resistance components is big.The approximately equivalent electricity of ferrite bead Road is by inductance, electric capacity, the circuit (non-patent literature 7) of parallel circuit connection in series with a resistor gained of resistance.Also proposed Use the cable correction (with reference to patent documentation 2) of ferrite bead.
It is illustrated in Figure 2 summary and the action of an existing embodiment.Fig. 2 is represent an existing embodiment three The block diagram of the coaxial camera chain of core.In fig. 2, the three coaxial camera chains of core are by image pickup part 1, triple-concentric cable 2, control Portion 3 is constituted.
After the imaging apparatus of image pickup part 1 102 carries out light-to-current inversion by the incident illumination after camera lens part 101 imaging, output To digital image signal process portion 204.Digital image signal process portion 204 implements the level amplification of signal of video signal, edge enhancement Export Deng processing laggard row.In the case of transmission path 2 is long, carry out image compression by image compression portion 105, in short feelings Under condition, it is directly output to time-division two-way switching part 210.In time-division two-way switching part 210, to digital image signal and digital sound Tone signal carries out time division multiplexing, carries out transmitted in both directions.From the serial digital signal of image pickup part 1 output via three core coaxial electrical Cable 2 is transferred to control portion 3.The serial digital signal being transferred to control portion 3 is decomposed by time-division two-way switching part 216, solves It is adjusted to original digital image signal and digital audio signal, carries out image and stretch, carry out letter by digital signal processing section 217 Number process after, be transformed to analog image signal by D/A changer 128, carry out output image signal.It addition, input from control portion 3 And transmit the most as described above from the external image signal of image pickup part 1 output.
Time-division two-way switching part 210 and 216 uses NMOS(N-channel Metal Oxidize at a high speed Semiconductor Field Effect Transistor:N NMOS N-channel MOS N field-effect transistor) bus The IC of switch, when when between the NMOS source-grid in the IC of NMOS bus switch, voltage does not guarantees about more than 1V, NMOS bus switch is not Conducting.During it addition, voltage is about 2V between the source-grid of NMOS in NMOS bus switch IC, the electric conduction of NMOS bus switch Resistance Rd is high.During it addition, voltage does not guarantees about more than 2.5V when between the source-grid of the NMOS in NMOS bus switch IC, NMOS bus Conducting resistance Rd of switch is not down to minimum.Therefore, by the signal of time-division two-way switching part from NMOS bus switch IC just Within supply voltage is significantly compressed the low-voltage of about 2.5V, significantly compressed about from the positive voltage of NMOS bus switch IC Within the low-voltage of 2V, it is restricted to below the low-voltage of about 1V from the positive voltage of NMOS bus switch IC.Concrete The on-resistance characteristics of the NMOS bus switch IC of conducting resistance Rd such as one embodiment of the invention of NMOS bus switch IC As shown in Fig. 8 A of ideograph, according to the positive voltage of NMOS bus switch IC, it is 10 Ω when 2.1V, when 2.5V is 8 Ω, are 7 Ω when 2.9V, are 6 Ω when 3.3V, are 5 Ω when 3.7V, are 4 Ω (with reference to non-patent literature 8) when 4.3V.
That is, in the case of carrying out time-division two-way switching, the sdi signal of earthing potential is conducting resistance during 0.8Vp-p Rd is 10 Ω～7 Ω in NMOS bus switch, relative to the characteristic resistance in the transmission path of triple-concentric cable or coaxial cable Anti-Rz=75 Ω, is the resistance value that cannot ignore of more than 5%, produces impedance mismatching and produces because reflecting the wave distortion caused. Further, the amplitude of sdi signal be resistance change during 0.8Vp-p in NMOS bus switch IC relative to 3 Ω and 75 Ω It is about the change that cannot ignore of 4%, produces upper and lower asymmetrical wave distortion.In order at the height receiving the side docking collection of letters number Frequently composition is amplified waiting frequency characteristic correction, the equalizer improved for the reception of sdi signal of 3G of 2970Mbps Wave shape equalization in, remain cause because of the reflection of impedance mismatching wave distortion, cause because of upper and lower asymmetrical wave distortion Phase place changes, it is impossible to be modified.Accordingly, it is difficult to extend transmission cable length.
5V low capacitance bus switch IC after improvement is also by commercialization, and the low capacitance bus such as one embodiment of the invention is opened Shown in Fig. 8 B of the ideograph closing the on-resistance characteristics of IC, according to positive voltage, it is 6 Ω when 1V, is 6.8 when 1.5V Ω, is 5 Ω when 2V, is 4.8 Ω when 2.1V, is 4.3 Ω when 2.5V, is 4.2 Ω when 2.7V～3.5V, when 3.9V It is 4 Ω, is 3.8 Ω (with reference to non-patent literature 9) when 4.5V.
Prior art literature
Patent documentation
Patent documentation 1: Unexamined Patent 7-203399 publication
Patent documentation 2: JP 2010-021993 publication
Non-patent literature
Non-patent literature 1:Gennum Security&Surveillance
http://www.gennum.com/applications/security-surveillance/hdcctv
Non-patent literature 2:ARIB-B07
http://www.arib.or.jp/english/html/overview/doc/4-TR-B07v2_0.pdf
Non-patent literature 3:Texas Instruments LMH0024
http://www.ti.com/lit/ds/symlink/lmh0024.pdf
Non-patent literature 4:Texas Instruments LMH0394
http://www.ti.com/lit/ds/symlink/lmh0394.pdf
Non-patent literature 5:Gennum GS2971A
http://www.gennum.com/extranet/document/55977
Non-patent literature 6:Texas Instruments LMH6703
http://www.ti.com/lit/ds/symlink/lmh6703.pdf
Non-patent literature 7:TDK mmz2012 equalizer
http://www.tdk.co.jp/etvcl/equivalent/mmz2012.pdf
Non-patent literature 8:Renesas technology high-speed bus switch HD74CBT series
http://hk.renesas.com/products/standard_ic/logic/hd74cbt/index.jsp
Non-patent literature 9: Toshiba 5V low capacitance bus switch TC7SB66CFU, TC7SB67CFU
http://www.semicon.toshiba.co.jp/docs/datasheet/en/LogicIC/ TC7SB66CFU_TC7SB67CFU_en_datasheet_110401.pdf
Summary of the invention
The problem that invention is to be solved
In the Digital Transmission of existing three core coaxial systems, carried out by the bit rate under the high frequency of more than 270Mbps Transmission, therefore the attenuation in cable increases, it is difficult to extend cable length.Especially in the case of carrying out time-division two-way switching, Relative to the characteristic impedance in the transmission path of triple-concentric cable or coaxial cable, the conducting resistance of simulation switch is to neglect Depending on resistance value.Further, by the amplitude of sdi signal, resistance change.Accordingly, it is difficult to postpone transmission cable length.
It is an object of the invention to, it is provided that one can remove these shortcomings, in the Digital Transmission of time-division two-way switching It also is able to the three core coaxial systems used with long cable length.
The technological means of solution problem
In order to achieve the above object, a kind of signal of video signal multiplex transmission apparatus, it is via a transmission to the present invention Path, to comprising digitized signal of video signal, acoustical signal, the digital signal of control signal carry out time-division two-way switching transmitting-receiving Digital image signal multiplex transmission apparatus, is characterized by that the end in the both sides in above-mentioned transmission path has the switching time-division many The IC of the simulation switch of road multiplexing, has waveform equalizer or the receptor comprising waveform equalizer, by above-mentioned receiving side The positive supply Vcc of the supply voltage of simulation switch is set to height, comprises digitized signal of video signal, sound letter so that above-mentioned Number, the characteristic that meansigma methods the is above-mentioned transmission path resistance of the conducting resistance of the above-mentioned simulation switch of the digital signal of control signal About less than the 1/10 of anti-resistance Rz, and the above-mentioned digital signal comprising digitized signal of video signal, acoustical signal, control signal Above-mentioned simulation switch conducting resistance the characteristic impedance resistance Rz being changed to above-mentioned transmission path about less than 1/30, pin Characteristic impedance resistance Rz to above-mentioned transmission path, possesses at least one unit following: to because of the conducting of above-mentioned simulation switch The unit that the increase of the end resistance that resistance causes is modified；Change to the conducting resistance because of above-mentioned simulation switch causes The unit that is modified of the distortion of the signal waveform caused by deviation of end resistance.
A kind of signal of video signal multiplex transmission apparatus, it is via a transmission path, to comprising digitized image letter Number, the digital signal of acoustical signal, control signal carry out time-division two-way switching transmitting-receiving, this digital image signal multiplexing transmission The feature of device is, the end in the both sides in above-mentioned transmission path has the NMOS of the simulation switch of switching time division multiplexing Bus switch IC, has waveform equalizer or the receptor comprising waveform equalizer, by above-mentioned simulation switch receiving side The positive supply Vcc of the supply voltage of NMOS bus switch IC is set to more than+2.9V, and by between positive supply Vcc and negative supply Vee Poor Vab be set to more than 4.5V below 5.5V, or, it is multiple that the end in the both sides in above-mentioned transmission path has switching time-division multiplex Simulation switch 5V low capacitance bus switch IC, receive side there is waveform equalizer or comprise connecing of waveform equalizer Receiving device, the positive supply Vcc of the supply voltage that the low capacitance bus of 5V of above-mentioned simulation switch is switched IC is set to more than+2.5V, And the poor Vab between positive supply Vcc and negative supply Vee is set to more than 4.5V below 5.5V, for the spy in above-mentioned transmission path Property impedance resistors Rz, possesses at least one unit following: to the end resistance caused because of the conducting resistance of above-mentioned simulation switch The unit that is modified of increase；Deviation institute to the end resistance that the change of the conducting resistance because of above-mentioned simulation switch causes The unit that the distortion of the signal waveform caused is modified.
It addition, at least there is following at least one in above-mentioned signal of video signal multiplex transmission apparatus: on making State the bus switch of the above-mentioned simulation switch of the digital signal comprising digitized signal of video signal, acoustical signal, control signal About less than the 1/100 of the characteristic impedance resistance Rz being changed to above-mentioned transmission path of the conducting resistance of IC, sets above-mentioned simulation The bus switch IC of the above-mentioned simulation switch of the positive supply Vcc of the supply voltage of the bus switch IC of switch；From above-mentioned biography The characteristic impedance resistance Rz in defeated path deducts the resistance value of the meansigma methods Rd gained of the conducting resistance of above-mentioned simulation switch The end resistance of Rz-Rd；The conducting resistance of the above-mentioned simulation switch receiving side of above-mentioned simulation switch is low (not by signal Waveform compression) to the Schottky-barrier diode of the ground connection that signal waveform polarity is compressed and being connected in series of resistance.
In above-mentioned signal of video signal multiplex transmission apparatus, being characterized by: amplifier, it is equal at the waveform receiving side Weighing apparatus or comprise waveform equalizer receptor before the waveform of above-mentioned digital signal is amplified；And group antibody, its table (the earth resistance or non-of the negative input that non-inverted is amplified of the amplifier being shown as and the waveform of above-mentioned digital signal is amplified Invert the earth resistance of the positive input amplified or the input resistance of the input of the output of reversion amplification and reversed polarity or amplifier Output resistance or two-stage amplifying circuit between connect resistance etc.) circuit characteristic resistance compares, the ripple of above-mentioned digital signal The impedance of the clock fundamental frequency of shape is low, the high inductance of the impedance of the clock order harmonic frequencies of the waveform of above-mentioned digital signal, The equivalent circuit of the approximation of the circuit after the circuit the being connected in parallel connection in series with a resistor of capacitor and resistance is (hereinafter referred to as Group antibody), carry out following at least one party: make to above-mentioned waveform equalizer or the receptor input that comprises waveform equalizer, on Low-frequency component decay below the clock fundamental frequency of the waveform stating digital signal, strengthens the clock of the waveform of above-mentioned digital signal Higher harmonic component, by Schottky-barrier diode and resistance (being uncompressed in above-mentioned simulation switch) in above-mentioned simulation In switch, the signal amplitude to negative direction is compressed；Or, the low capacitance bus of 5V about above-mentioned simulation switch switchs The supply voltage of IC, is set to the difference between positive supply Vcc and negative supply Vee when positive supply Vcc about 3.2V by negative supply Vee Vab is at more than 4.5V below 5.5V.(reducing the change of the conducting resistance that amplitude of transmission signal is switch during 0.8Vp-p).
Further, in above-mentioned signal of video signal multiplex transmission apparatus, being characterized by: amplifier, it is in sending side Above-mentioned simulation switch before the waveform of above-mentioned digital signal is amplified；And above-mentioned impedance body, make to sending side Low-frequency component decay below the clock fundamental frequency of the input of above-mentioned simulation switch, above-mentioned digital signal waveform, strengthens The clock higher harmonic component of the waveform of above-mentioned digital signal.
It addition, in above-mentioned signal of video signal multiplex transmission apparatus, above-mentioned digital signal be (25Mbps, 50Mbps, 100Mbps, 270Mbps, 1500Mbps, 2970Mbps's etc.) serial digital interface (SDI) signal, above-mentioned impedance body is ferrum oxygen At least one in body magnet ring, ferrite bead and resistance and inductance and resistance.
It addition, a kind of signal of video signal multiplex transmission apparatus, it is via a transmission path, to comprising digitized shadow Image signal, acoustical signal, the digital signal of control signal carry out time-division two-way switching transmitting-receiving, and this digital image signal multiplexes The feature of transmitting device is, the end in the both sides in above-mentioned transmission path has the simulation switch of switching time division multiplexing Bus switch IC, has waveform equalizer or the receptor comprising waveform equalizer, for above-mentioned transmission path receiving side The characteristic impedance resistance in above-mentioned transmission path, possesses at least one unit following: to because of the bus switch of above-mentioned simulation switch The unit that the increase of the end resistance that the conducting resistance of IC causes is modified；To because of the bus switch IC of above-mentioned simulation switch The unit that is modified of the distortion of the signal waveform caused by deviation of end resistance that causes of the change of conducting resistance.
Further, a kind of camera head, it is characterized by possess: there is imaging apparatus, signal of video signal process portion, CPU(centre Reason unit) image pickup part；Above-mentioned signal of video signal multiplex transmission apparatus；And there is signal of video signal process portion, image letter Number input and output portion, the control portion of CPU, carry out time-division two-way multiplexing transmission to signal of video signal.
Invention effect
As described above, in accordance with the invention it is possible to improve due to the simulation switch carrying out time-division two-way switching The impedance mismatching that causes of conducting resistance of NMOS bus switch IC or 5V low capacitance bus switch IC and produce reflection distortion, Or the asymmetric deterioration of signal waveform that the change of the conducting resistance caused due to signal voltage causes, it is possible to extend digitized video The cable length of signal multiplex transmission apparatus.
Accompanying drawing explanation
Fig. 1 is the integrally-built block diagram of one embodiment of the present of invention.
Fig. 2 is the integrally-built block diagram representing an existing embodiment.
Fig. 3 A is reversion amplifying circuit and the block diagram of switch of one embodiment of the present of invention.
Fig. 3 B is non-inverted amplifying circuit and the block diagram of switch of one embodiment of the present of invention.
Fig. 3 C is the drive circuit of one embodiment of the present of invention, waveform equalizer or the reception comprising waveform equalizer Device, the block diagram of switch.
Fig. 3 D is the drive circuit of one embodiment of the present of invention, waveform equalizer or the reception comprising waveform equalizer Device, the block diagram of switch.
Fig. 3 E is reversion amplifying circuit and the block diagram of switch of one embodiment of the present of invention.
Fig. 3 F is reversion amplifying circuit and the block diagram of switch of one embodiment of the present of invention.
Fig. 4 A is the input-output wave shape figure of the reversion amplifying circuit of one embodiment of the present of invention.
Fig. 4 B is the input-output wave shape figure of the non-inverted amplifying circuit of one embodiment of the present of invention.
Fig. 4 C is the drive circuit of one embodiment of the present of invention, waveform equalizer or the receptor comprising waveform equalizer Input-output wave shape figure.
Fig. 4 D is the drive circuit of one embodiment of the present of invention, waveform equalizer or the receptor comprising waveform equalizer Input-output wave shape figure.
Fig. 4 E is the input-output wave shape figure of the reversion amplifying circuit of one embodiment of the present of invention.
Fig. 5 is the ideograph of the frequency characteristic of the ferrite bead of one embodiment of the present of invention.
Fig. 6 is the block diagram of existing drive circuit, waveform equalizer, switch.
Fig. 7 is the input-output wave shape figure of existing drive circuit, waveform equalizer, switch.
Fig. 8 A is the ideograph of the on-resistance characteristics of the NMOS bus switch IC of one embodiment of the present of invention.
Fig. 8 B is the ideograph of the on-resistance characteristics of the low capacitance bus switch IC of one embodiment of the present of invention.
Detailed description of the invention
In the case of carrying out time-division two-way switching, as the 0014th paragraph of background technology, due to simulation switch Conducting resistance and produce impedance mismatching, produce because of the wave distortion that causes of reflection.And then, owing to simulating the electric conduction of switch Resistive, produces upper and lower asymmetrical wave distortion.Therefore, it is amplified equifrequency at the radio-frequency component receiving the side docking collection of letters number Rate characteristic revision, the equalizer (Equalizer) improved to receive the sdi signal of the 3G of 2970Mbps are (with reference to non-patent Document 4) or comprise in the wave shape equalization in the receptor (Receiver) (with reference to non-patent literature 5) of waveform equalizer, can be residual Stay the wave distortion caused because of reflection or the phase place change caused because of upper and lower asymmetrical wave distortion, it is impossible to revise.Therefore, as Fruit is due to the wave distortion caused because of the reflection of impedance mismatching, the change of the conducting resistance of simulation switch, and it is upper and lower non-right to produce The wave distortion claimed, then be difficult to extend transmission cable length.
Therefore, in the present invention, the impedance that the conducting resistance of simulation switch during sdi signal 0.8Vp-p causes is lost Join and be reduced to transmit about less than the 1/50 of the characteristic impedance Rz=75 Ω in path, and then be modified so that by simulation switch Conducting resistance change is reduced to about less than the 1/30 of Rz=75 Ω.
Specifically, path is being transmitted via one, to comprising digitized signal of video signal, acoustical signal, control signal Digital signal carry out time-division two-way switching transmitting-receiving digital image signal multiplex transmission apparatus in, transmission path two The end of side has the NMOS bus switch IC of the non-patent literature 8 of the simulation switch of timesharing switching both direction, is receiving Side has waveform equalizer or the receptor comprising waveform equalizer, about the supply voltage of NMOS bus switch IC, by positive electricity Source Vcc is set to more than+2.9V, and the poor Vab between positive supply Vcc and negative supply Vee is set to more than 4.5V below 5.5V, relatively In each voltage-0.4V to+0.4V of amplitude 0.8Vp-p DC potential 0V of the sdi signal being transmitted, make NMOS bus switch Conducting resistance be 8 Ω～6 Ω conducting resistance be changed to 2 Ω, relative to transmission path characteristic impedance 75 Ω reduce about 2.7%.Or, NMOS bus switch IC has the positive supply of about more than 3V, by by the numeral letter of above-mentioned NMOS bus switch IC Number bias is (bearing) voltage of about 2.5V more than lower than this positive voltage.
It addition, relative to the characteristic impedance Rz=75 Ω in above-mentioned transmission path, by the conducting resistance of NMOS bus switch IC Meansigma methods Rd reduce the Rso=Rz-Rd=75-7=68 after about 7 Ω, 68 Ω are set to end resistance value, obtain impedance matching, fall Low reflection distortion.
Or, the end in the both sides in above-mentioned transmission path have switching time division multiplexing simulation switch non-specially The 5V low capacitance bus switch IC of profit document 9, has waveform equalizer or the receptor comprising waveform equalizer receiving side, closes In the supply voltage of 5V low capacitance bus switch IC, positive supply Vcc is set to more than+2.5V, by positive supply Vcc and negative supply Poor Vab between Vee is set to more than 4.5V below 5.5V, relative to the characteristic impedance Rz=75 Ω in above-mentioned transmission path, passes through 5V Conducting resistance Rd of 4.8 Ω～4.2 Ω of low capacitance bus switch reduces the Rso=Rz-Rd=after meansigma methods about 4.5 Ω 75-4.5=70.5 ≈ 71 ≈ 68+2.7, is set to end resistance value by the series connection of 68 Ω and 2.7 Ω, according to mean error 0.2 Ω 0.3% range of error below precision, obtain impedance matching, reduce reflection distortion.
The aggregate value of the conducting resistance of output end resistance and simulation switch, reception end resistance and simulation switch Characteristic impedance 75 Ω in the transmission path of the aggregate value of conducting resistance, triple-concentric cable or coaxial cable is roughly equal, because of resistance The wave distortion that anti-mismatch and reflection cause reduces.And then, when the amplitude 0.8Vp-p of sdi signal, the change phase of resistance value For 75 Ω, in NMOS bus switch IC, reduce about 2.7%, in 5V low capacitance bus switch IC, reduce about 0.8%, the most non- Symmetrical wave distortion reduces.
But, the present invention is not limited to NMOS bus switch IC and 5V low capacitance bus switch IC, it is possible to use electric conduction Hinder the IC of the simulation switch of low high speed.The characteristic of the conducting resistance of the IC of the simulation switch according to the low high speed of conducting resistance, By positive supply Vcc and the value of negative supply Vee, output end resistance and the reception value of end resistance, the electricity of above-mentioned simulation switch The positive supply Vcc of source voltage is set to height, so that the conducting of the above-mentioned simulation switch during amplitude 0.8Vp-p of sdi signal The meansigma methods of resistance is about less than the 1/10 of the characteristic impedance resistance Rz in above-mentioned transmission path, and the amplitude of sdi signal About the 1/ of the characteristic impedance resistance Rz being changed to above-mentioned transmission path of the conducting resistance of above-mentioned simulation switch during 0.8Vp-p Less than 30.As a result, the impedance mismatching that the conducting resistance of simulation switch when reducing sdi signal 0.8Vp-p causes, and then fall The conducting resistance change of low simulation switch.
And then, the conducting resistance with the above-mentioned simulation switch receiving side is low, signal un-compressed to signal waveform The Schottky-barrier diode of the ground connection that the polarity of waveform is compressed and the series circuit of resistance, by switch to not pressure The signal of contracting is compressed, and obtains the upper and lower balance of signal waveform.
Or, the low capacitance bus of 5V if, with non-patent literature 9 switchs conducting resistance Rd of IC at positive voltage For being situation constant for 4.2 Ω during 2.7V～3.5V, use 5V low capacitance bus switch, and then when positive supply Vcc is+3.2V Being set to Vee is-1.3V～-2.3V, then the conducting resistance Rd during 0.8Vp-p of the sdi signal of earthing potential is that 4.2 Ω are permanent Fixed, there is no the change of resistance value, upper and lower asymmetrical wave distortion disappears.
As a result, receiving side, equalizer (equilibrium) IC that receives at sdi signal or comprise the receptor of waveform equalizer In IC, easily by the wave shape equalization of waveform reverted to when sending to carry out the correction of sdi signal.Therefore, it is possible to make waveform The deterioration that equilibrium causes becomes minimum, therefore, it is possible to carry out the wave shape equalization corresponding with long cable.It is same that cable 2 is more than three cores Shaft cable, for common coaxial cable, it is possible to use the cable longer than prior art is transmitted.And then, and in cable Transmitted waveform revise signal independently and deteriorate, therefore, it is possible to easily tackle owing to inserting the change of length that junction cable causes More, more than triple-concentric cable, for common coaxial cable, it is possible to revise the cable longer than prior art.It addition, for In the equalizer receiving the sdi signal of the 3G of 2970Mbps and improve or the receptor comprising waveform equalizer, wave shape equalization It is effective, it is possible to revise longer cable.
And then, at HD-SDI signal, the UHDTV of the sdi signal of 3G of 2970Mbps, about 24000Mbps of 1500Mbps Sdi signal transmission in, for triple-concentric cable, common coaxial cable, it is possible to use the electricity longer than prior art Cable is transmitted.
Hereinafter, it is illustrated in Figure 1 the entirety of the three coaxial camera chains of core of one embodiment of the present of invention, then uses Fig. 3 A～Fig. 3 C, Fig. 4 A～Fig. 4 C illustrate reversion amplifying circuit and the frame of non-inverted amplifying circuit of one embodiment of the present of invention Figure, input-output wave shape figure, the ideograph of action.
Fig. 1 is the overall block diagram of the three coaxial camera chains of core representing one embodiment of the present of invention, by image pickup part 1, triple-concentric cable 2, control portion 3 are constituted.101 is the camera lens part for not shown incident illumination carries out imaging, and 102 is right Carried out the imaging apparatus of light-to-current inversion by the light of camera lens part 101 imaging, 103 is that signal of video signal is transformed to digital image signal A/D changer, 104 and 127 is that digital image signal is amplified to predetermined level, or implements the shadow of the process such as edge enhancement As process portion.The image compression portion of 105 and 136 compressions being by image, 107 and 135 is to digital image signal, digital sound Tone signal, control signal (cpu data) carry out the encoding section multiplexed, and 108 and 133 is putting of being amplified digital signal Big portion, 109 and 134 is the enlarging section of the frequency characteristic revising triple-concentric cable 2, is positioned at waveform equalizer or the bag receiving side Before receptor containing waveform equalizer.About the switching of this enlarging section, pass through from image pickup part accordingly with the length of cable 2 1 or the control of the CPU113 in control portion 3 and 130, if enlarging section is by having the amplifier of shut-off function or having handoff functionality Amplifier or low-impedance switching IC constitute, then carry out the switching of this enlarging section by enlarging section 108,109,133,134.Double The simulation switch of time division multiplexing to portion 112 and 121, have long cable with and stub cable with the 108 of each 2 groups, 109, in the case of the enlarging section of 133,134, it is also possible to switched over by two-way portion 112 and 121.113 and 130 is for controlling The CPU(CPU of system), 120 is joint image pickup part 1 and triple-concentric cable 2 connected, and 142 is that connection three cores are same Shaft cable 2 and the joint in control portion 3,112 is the signal of video signal generating image pickup part 1, the external image come from control portion 3 transmission Signal carries out the two-way portion of time-division switching, and 121 are by external image signal and transmit cutting of next signal of video signal from image pickup part 1 The switching part changed, 119 and 122 are by the waveform equalizer of the wave shape equalization of the signal that transmission comes or comprise waveform equalizer Receptor, 116 and 125 is the lsb decoder being demodulated into original digital image signal and digital audio signal, 115 and 126 be into The image extending part of the stretching, extension of row image, 114 and 128 is the D/A conversion that digital image signal is transformed to analog image signal Device (DAC), 138 is amplifier.
Then, the action of one embodiment of the present of invention is described.
When switching on power, by being measured the retardation of cable 2 by the CPU113 of image pickup part 1 or the CPU130 in control portion 3 Or attenuation, detect the length of cable 2.The length transmission of the cable 2 detected to image pickup part 1 or the CPU in control portion 3, The length of common cable 2 in image pickup part 1 and control portion 3.
As the non-patent literature 1 of background technology, image serial digital interface (SDI) signal uses based on G(x)=(x9 +x4+ 1) motor synchronizing type scrambler (Non Return To Zero) the NRZ-I code of (x+1) such generator polynomial, by data 0/1 be replaced into 0 → 1,1 → 0 inversion information, be achieved in the polarity equally distributed sdi signal of free frequency spectrum.If applied Such motor synchronizing type scrambler, then in serial transmission paths, on 1 horizontal line, sometimes produce at 1 bit 1 followed by The signal of pattern (or its reversing mode) of the 0 of 19 bits, behind the 1 of continuous 20 bits the 0 of continuous 20 bits pattern (or its Reversing mode) signal.These patterns are referred to as morbid state pattern.Therefore, if according to the morbid state greatest length 20 of pattern, SDI The order harmonic frequencies of 1/20 transmission 3 times of the fundamental clock frequency of signal, then can inerrably transmit sdi signal.Generating During sdi signal, if making the shorter motor synchronizing type scrambler of greatest length of morbid state pattern, then frequency band can be made further to become Narrow.
Here, the sdi signal of the forward generated by image pickup part has the data volume of 270Mbps when NTSC, when HDTV There is the data volume of 1500Mbps.The sdi signal of 3G has the data volume of 2970Mbps.The anticipation of UHDTV sdi signal has The data volume of 24000Mbps.It addition, the signal of video signal of the loopback transmitted to image pickup part loopback from control portion is being pressed by MPEG2 During contracting, image compression ratio substantially 1/5, carry out forward sdi signal and compression after loopback sdi signal time-division switching or frequency The two-way portion ideal that rate is selected is the IC of the simulation switch of time-division.When by H.264 compressing, raw with respect to image pickup part The 1500Mbps of the sdi signal of the forward become, the sdi signal after the image compression in loopback direction is that 25Mbps image compression ratio is 1/60, it is also possible to become the greatest length 20 of morbid state pattern and the inverse less than 1/60 of the product 60 times of higher hamonic wave number of times 3.Will Acoustical signal, control signal (cpu data signal) overlap in sdi signal, after therefore carrying out sdi signal and the compression of forward The two-way portion that the time-division switching of loopback sdi signal or frequency are selected can also be the SDI being made forward by high pass filter (HPF) Signal passes through, and is made the sdi signal after the image compression in loopback direction pass through by low pass filter (LPF), believes the SDI of forward Number and the image compression in loopback direction after sdi signal carry out the combination of transmitted in both directions.
It addition, from control portion 3 input be transmitted back to image pickup part 1 and from image pickup part 1 output external digital signal of video signal also with Above-mentioned similarly it is transmitted.In FIG, the image compression in loopback direction is compressed in image compression portion 136, but also may be used With the external digital signal of video signal after input compression.
The imaging apparatus 102 of image pickup part 1 carries out light-to-current inversion to by the incident illumination of camera lens part 101 imaging, and output is to number Word signal of video signal process portion 104.Digital image signal process portion 104 implements the level amplification of signal of video signal, edge enhancement etc. Reason exports.In image compression portion 105, in the case of the sdi signal of HDTV and the sdi signal of 3G, carry out low latency Image compression, in the case of UHDTV sdi signal, carry out the image compression of high compression ratio H.264 waited, by sdi signal The 270Mpbs of the sdi signal of boil down to 270Mbps, NTSC is directly output to encoding section 107.In encoding section 107, to numeral Signal of video signal, digital audio signal, cpu data multiplex.Signal after multiplexing in the case of cable 2 is long, It is amplified by enlarging section 108 and 109.In the case of short, it is set to constant low amplification.From repairing of image pickup part 1 output Positive digital signal waveform is transferred to control portion 3 via cable 2.
It is explained above the transmission of the 4:2:2 signal of video signal of the NTSC of 270Mbps, but for the signal of video signal of HDTV The 1500Mbps(4:2:2 of HD-SDI), 3000Mbps(4:4:4), SHDTV, anticipation have the UHDTV of data volume of 24000Mbps SDI, if A/D changer, D/A changer, amplifier, waveform equalizer or comprise the receptor of waveform equalizer, bus The high speeds such as switch IC, then also be able to be suitable for.
And then, if possessed, there is imaging apparatus, signal of video signal process portion, CPU(CPU) image pickup part (Camera Head photographic head), signal of video signal multiplex transport part (Camera Adaptor camera adaptor), have shadow Image signal process portion, signal of video signal input and output portion, control portion (the Camera Control Unit camera control list of CPU Unit), then be capable of sports facility, hall inside without again laying optical cable, use in sports facility, hall The triple-concentric cable laid, carries out time-division two-way multiplexing transmission, it is possible to by sports facility, hall to signal of video signal The signal of video signal transmission unit of outside wired (optical networking) or wireless (Field Pick Up outdoor shooting) is transferred to broadcast electricity Television stations, maybe can carry out recording a video i.e. carries out the so-called camera head (video camera) playing relaying.
Embodiment 1
As described in the background art, operating amplifier with current feedback if little amplitude, amplification are 2 times, Then can be to until the high frequency of about 1.2GHz be amplified.But, the amplification transistor within operating amplifier with current feedback Emitter stage be connected with negative input terminal, if radio-frequency component is not resistance components, then the connection impedance of negative feedback input terminal Easily on high frequency, cause vibration.Therefore, do not use electric capacity by the negative feedback input terminal ground connection of operating amplifier with current feedback, But between the output and the negative input of operating amplifier with current feedback of operating amplifier with current feedback, arrange the one of the present invention Substantially 25MHz or 270MHz or 1500MHz as Fig. 5 of the ideograph of the frequency characteristic of the ferrite bead of embodiment or Impedance (resistance) under clock fundamental frequency Fc of 3000MHz is more negative than what the non-inverted of above-mentioned operating amplifier with current feedback was amplified The input resistance of the negative input that the earth resistance of input or reversion are amplified is low, impedance (resistance) ratio under clock order harmonic frequencies The ferrite bead that the input resistance of negative input that the earth resistance of the negative input that non-inverted is amplified or reversion are amplified is high, makes transmission The low-frequency component decay of signal, amplifies radio-frequency component.In the case of the output impedance rise of high frequency, add current buffer IC。
And then, the input at waveform equalizer or the receptor (hereinafter referred to as waveform equalizer) that comprises waveform equalizer is shaken In the case of width does not has enough and to spare, only long in transmission path (triple-concentric cable or coaxial cable), when the loss in transmission path is big, Improving amplification, short in transmission path, the loss hour in transmission path, if being set to 0dB(to get rid of characteristics match damage by amplification Lose, be then+6dB) near.
It is transferred to the digital signal waveform in control portion 3 in the case of cable 2 is long, makes fundamental frequency by enlarging section 109 Following low-frequency component decay, after strengthening the higher harmonic component of more than three times, carries out waveform by waveform equalizer 122 equal Weighing apparatus, then, is demodulated into original digital image signal and digital audio signal by lsb decoder 125, by image pars contractilis 126 Carry out image to stretch, after carrying out signal processing by digital signal processing section 127, be transformed to simulate shadow by D/A changer 128 Image signal, exports from amplifier 138.It addition, also regenerate cpu data, voice data from lsb decoder 125.Enlarging section 108 He 109, the performance of waveform equalizer 119 and 122 improves, it is possible in the case of the high data volume of transmission 1500Mbps etc., reduce shadow Lower delay is become as the compression ratio of compression unit 105.If able to carry out the image compression of high compression ratio with low latency, then By below 100Mbps such as output sdi signal boil down to 25Mbps, the 50Mbps in image compression portion 105, real by the one of the present invention The ferrite magnetic of impedance variation at low frequencies as the Fig. 5 (c) of the ideograph executing the frequency characteristic of the ferrite bead of example Ring, makes the low-frequency component of below the clock fundamental frequency of sdi signal decay, and strengthens higher harmonic component.
Two-way portion 112 and 121 is made up of HPF and LPF, and two-way portion 112 and 121 is that the NMOS of the simulation switch of time-division is total The low capacitance bus of wiretap IC or 5V switchs.In the case of there is no enough and to spare by signal amplitude, when the length of cable 2 is long, Make amplification constant under the frequency within three higher hamonic waves of the sending side, prevented from bringing restriction amplitude, make receiving side Low-frequency component decay below fundamental frequency, strengthens the higher harmonic component of more than three times.
Hereinafter, for the purpose of simplifying the description, illustrated by the common current feedback operational amplifier in broadband.With using The Voltage Feedback operational amplifier in broadband.
Fig. 3 A is the block diagram of the reversion amplifying circuit of one embodiment of the present of invention, and Fig. 3 B is one embodiment of the present of invention The block diagram of non-inverted amplifying circuit, Fig. 4 A is the input-output wave shape of the reversion amplifying circuit of one embodiment of the present of invention Figure, Fig. 5 is the ideograph of the frequency characteristic of the ferrite bead of one embodiment of the present of invention.Impedance body used in the present invention It is that Fig. 5 represents ferrite bead as the ideograph of the frequency characteristic example of ferrite bead or represents the frequency as Fig. 5 The inductance of rate characteristic example is connected in parallel and resistance with electric capacity.
Fig. 3 A and Fig. 3 B is the current feedback operational using and can guaranteeing frequency band 3Fc under reversion+6dB, non-inverted+12dB The situation of the IC1 of amplifier or operating amplifier with current feedback and current buffer IC.As described in the background art, Operating amplifier with current feedback is under the little amplitude of 0.2Vp-p, if 0dB then can be to until the high frequency of about 1.8GHz enters Row amplifies, if the high frequency until about 1.2GHz then can be amplified by+6dB, if the big amplitude of 2Vp-p, then Can be to until the high frequency of about 750MHz be amplified.Therefore, High frequency amplification can have enough and to spare, if therefore ferrite bead The impedance variation of frequency characteristic big, then can revise longer cable.
In Fig. 3 A～Fig. 3 F, IC2, IC5～IC14 are NMOS bus switch IC, and D10, D11 are Schottky barrier two pole Pipe (hereinafter referred to as SBD), Z1, Z2, Z5～Z24 be the frequency characteristic of Fig. 5 ideograph as ferrite bead, C1～C14, Co is electric capacity, and Ro is output resistance, and Rso is output end resistance, R1～R7, R11, R12 are resistance.Vin is sending side input Signal, Vso sending side output signal, Vrin sending side input signal, Vro is to receive side to amplify output signal.Vo is to receive side Output signal.
The characteristic resistance one of the input of the output resistance Ro of the enlarging section 134 of Fig. 3 A and Fig. 3 B and next equalizer 122 Cause, if but the length of arrangement wire of the input of the output of the amplifier of enlarging section 134 and next equalizer 122 is digital signal The 1/8(of the wavelength of the clock fundamental frequency of waveform is if 270MHz is then 154mm) below, then output resistance Ro may be short Road.As Fig. 3 A and Fig. 3 B, in the case of using as amplifier 108, output end resistance Rso becomes transmission path 2 General characteristic resistance Rz75 Ω deduct the value of conducting resistance Rd gained of NMOS bus switch IC.NMOS bus switch IC's Conducting resistance Rd, according to positive voltage Vcc, is 8 Ω when 2.5V, is 7 Ω when 2.9V, is 6 Ω when 3.3.Therefore, exist In the case of the simulation switch of Fig. 3 A and Fig. 3 B employs NMOS bus switch IC, straight according to during positive supply Vcc+2.9V 8 Ω～6 Ω of conducting resistance Rd under the amplitude of stream current potential sdi signal, average out to 7 Ω.Output end resistance Rso is from 75 Ω Deduct the value of 7 Ω gained, be 68 Ω.The reception end resistance R6 of Fig. 3 A is about 68 Ω, the reception end resistance R3 of Fig. 3 B and 68 Ω that add up to receiving end resistance R4 are optimum, but according to 33+36=69, even about 69 Ω, error about 1.3% is also Can allow for.
Conducting resistance Rd of NMOS bus switch IC, according to positive voltage, is 7 Ω when 2.9V, is 6 Ω when 3.3V, Being 5 Ω when 3.7V, if therefore positive supply Vcc being risen to more than 3.3V, then output end resistance Rso is for having deducted conducting 69 Ω of average 6 Ω of resistance Rd are optimum, even if being 68 Ω, error about 1.3% also is able to allow.
It addition, use the feelings of the 5V low capacitance bus switch of non-patent literature 9 in the simulation switch of Fig. 3 A and Fig. 3 B Under condition, conducting resistance Rd, according to positive voltage Vcc, is 4.8 Ω when 2.1V, is 4.3 Ω when 2.5V, at 2.7V～3.5V Time be 4.2 Ω.Therefore, conducting resistance Rd under positive supply Vcc is the amplitude of DC potential sdi signal during+2.5V is 4.8 Ω ～4.2 Ω, average out to 4.5 Ω.Deduct Rd from Rz, be 68 Ω and 2.7 for 75-4.5=70.5=33+36+1.5 ≈ 68+2.7, R6 The series connection of Ω, is 0.2 Ω with the error of Rz75 Ω, is 0.3% within range of error, and R3 is 33 Ω, and R4 is 36 Ω and 1.5 Ω, Error is not had with Rz75 Ω.
That is, making Rso+Rd=Rz, R6+Rd=Rz, R3+R4+Rd=Rz is below range of error, obtains impedance matching, reduces anti- Lost very.
And then, by receiving that the conducting resistance of the simulation switch of side is low and that signal waveform is not compressed signal wave The Schottky-barrier diode D10 of the ground connection that shape polarity is compressed and being connected in series of resistance R11, obtain the upper of signal waveform Under balance.
Utilize conducting resistance Rd of the C that the low capacitance bus of 5V of non-patent literature 9 switchs according to positive voltage at 2.7V ～constant during 3.5V be the situation of 4.2 Ω, use 5V low capacitance bus switch, and if then when positive voltage Vcc is+3.2V, Vee is set to-1.3V～-2.3V, then conducting resistance during the 0.8Vp-p of the sdi signal of earthing potential is constant is 4.2 Ω, There is no the change of resistance value, there is no upper and lower asymmetrical wave distortion.Therefore, there is no need to repairing of upper and lower asymmetrical wave distortion Positive D10 and R11, disconnects D10 or R11.
In Fig. 3 A, Fig. 3 B, Fig. 4 A, Fig. 4 B, by the switching of bus switch device IC2, transmission cable be closely time, The R1 of the earth resistance of the negative input according to operational amplifier or the input resistance of negative input and the output of operational amplifier and fortune The ratio of the value of the R2 of the feedback resistance between the negative input of calculation amplifier, amplification (gain) is the most constant with frequency, output For 0.8Vp-p.It addition, when transmission cable is remote, such as, for SDI, output and computing according to operational amplifier are put The frequency characteristic of the ferrite bead Z1 of the feedback between the negative input of big device, low cut, high frequency enhancement.Specifically, right In the BLM15BA220SN of Fig. 5 (a) of ideograph of frequency characteristic of the ferrite bead of one embodiment of the invention, at first-harmonic Under neighbouring 300MHz, the amplitude of first-harmonic composition substantially reduces 0.4Vp-p, under the 1000MHz near the higher hamonic wave of three times Being 505 Ω, the amplitude of three times of higher harmonic component substantially increases 1.4Vp-p.It addition, for HD-SDI, ferrite bead Z1 is such as The MMMZ0603F100C of Fig. 5 (b) of the ideograph of the frequency characteristic of the ferrite bead of one embodiment of the invention is the most in parallel 3, be 66 Ω under the 1500MHz near first-harmonic, and the amplitude of first-harmonic composition substantially reduces 0.4Vp-p, humorous at the high order of three times Being 220 Ω under 4500MHz near ripple, the amplitude of three times of higher harmonic component substantially increases 1.2Vp-p.General diameter 8.6mm The attenuation of 300MHz of triple-concentric cable be 12dB when 100m.Therefore, if making low cut 6dB, High frequency amplification 6dB, then for SDI, even substantially extending the cable of 100m, it is also possible to carry out wave shape equalization.If sending and receiving Both sides the amplifying circuit of one embodiment of the invention of Fig. 3 A or Fig. 3 B is set, then correction and cable extension amount are at double, right In SDI, even substantially extending the cable of 200m, it is also possible to carry out wave shape equalization.
Only in the case of the length length of cable 2, strengthening radio-frequency component in sending side, low-frequency component of decaying, thus because connecing Receive the correction minimizing that the wave shape equalization of side causes, therefore, it is possible to the deterioration making wave shape equalization cause becomes irreducible minimum, accordingly, it is capable to Enough carry out the wave shape equalization corresponding with long cable.And then, and the characteristic that the frequency of first-harmonic as one man selects ferrite bead, by This can carry out the wave shape equalization corresponding with longer cable.
If less than half that fundamental frequency impedance is negative input resistance, three order harmonic frequencies impedances are negative input The ferrite bead of more than 2 times of resistance, then be practical.
In Fig. 3 C and Fig. 4 C, calculate, such as, for SDI, ferrite bead Z1 is at Fig. 5 (a) of ideograph Can ignore when BLM15BA220SN, 100MHz, be about 167 Ω when resistance R5=220 Ω is in parallel with resistance R2=680 Ω, It is 505 Ω when the amplitude of first-harmonic composition substantially 0.4Vp-p, 1000MHz near three times of higher hamonic waves, at 725 Ω and electricity Resistance R2=680 Ω in parallel time be about 351 Ω, the amplitude of three times of higher harmonic component substantially 0.8Vp-p.It addition, for HD- SDI, can be set to the pattern of the frequency characteristic of the ferrite bead of 3 one embodiment of the invention in parallel by ferrite bead Z1 The MMMZ0603F100C of Fig. 5 (b) of figure.It addition, H.264 wait image compression to maintain high image quality and high compression ratio, become lower Delay, in the case of can be with the signal of video signal of the lower data transfers video cameras such as 50Mbps, can be by ferrite Magnet ring Z1 is set to Fig. 5's (c) of the ideograph of the frequency characteristic of the ferrite bead of one embodiment of the invention MMMZ2012D301B。
Such as, calculating, for SDI, ferrite bead Z1 is the BLM15BA220SN of Fig. 5 (a) of ideograph, at base Being 73 Ω near ripple 300MHz, the amplitude substantially 0.4Vp-p when connecting about 148 Ω with resistance R5=75 Ω, at three times of high orders At 1000MHz near harmonic wave, it is that connecting of 505 Ω and resistance R5=75 Ω is about 580 Ω, shaking of three times of higher harmonic component Width substantially 2.4Vp-p.It addition, for HD-SDI, calculate, if ferrite bead Z1 is the one of 3 present invention in parallel The MMMZ0603F100C of Fig. 5 (b) of the ideograph of the frequency characteristic of the ferrite bead of embodiment, then attached at first-harmonic 1500MHz Being closely 66 Ω, connect amplitude substantially 0.4Vp-p when being about 141 Ω with resistance R5=75 Ω, near three times of higher hamonic waves Being that connecting of 220 Ω and resistance R5=75 Ω is about 295 Ω during 4500MHz, the amplitude of three times of higher harmonic component is substantially 2.4Vp-p.The attenuation of the 1500MHz of the triple-concentric cable of general diameter 8.6mm is about 19dB when 100m.Therefore, as Fruit makes low cut 6dB, by High frequency amplification 9dB, then for HD-SDI, even substantially extending the cable of 85m, it is also possible to enter Row wave shape equalization.For SDI, even substantially extending the cable of 125m, it is also possible to carry out wave shape equalization.
Thus, it is also possible to the HD-SDI of reply 1500Mbps.It addition, for the SDI of 300Mbps, the energy when High frequency amplification Enough there is enough and to spare, if therefore the impedance variation of the frequency characteristic of ferrite bead becomes much larger, then can revise longer cable.
And then, if the high frequency characteristics of amplifier, ferrite bead is improved, even if then at the 3G of 2970Mbps In the transmission of the sdi signal of the UHDTV of sdi signal, about 24000Mbps, for triple-concentric cable, common coaxial electrical Cable, it is also possible to be transmitted with the cable longer than prior art.
In Fig. 3 A and Fig. 3 B, it is assumed that switched over by the simulation switch of enlarging section, but Fig. 3 A and Fig. 3 B can also Then amplify by switching over the operational amplifier of shutdown (SD) function.
Embodiment 2
Omit the explanation of the part identical with embodiments of the invention 1.
The amplifying circuit of one embodiment of the present of invention of Fig. 3 A and Fig. 3 B of embodiments of the invention 1 and the frame of switch Scheme the drive circuit of one embodiment of the invention of Fig. 3 C and Fig. 3 D, waveform equalizer with embodiments of the invention 2 or comprise The receptor (hereinafter referred to as waveform equalizer) of waveform equalizer, switch block diagram between difference be, by Fig. 3 A and figure The amplifying circuit that sends of 3B is changed to Fig. 3 C and the drive circuit of Fig. 3 D and the Co of electric capacity, and the reception of Fig. 3 A and Fig. 3 B is amplified electricity Road is changed to Fig. 3 C and the equalizer of Fig. 3 D.
In the case of employing NMOS bus switch IC in the simulation switch of Fig. 3 C and Fig. 3 D, by supply voltage just Power Vcc rises to more than+2.9V even about 3.3V, make the poor Vab between positive supply Vcc and negative supply Vee be 4.5V with Upper, below 5.5V, is reduced to about 1.7V by negative supply voltage Vee, relative to the amplitude 0.8Vp-p of the sdi signal transmitted DC potential 0V(earthing potential center) each voltage-0.4V～+0.4V, reduce the NMOS bus switch of simulation switch Conducting resistance and the change of conducting resistance.Conducting resistance Rd of NMOS bus switch IC is according to positive voltage Vcc, when 2.5V It is 8 Ω, is 7 Ω when 2.9V, be 6 Ω when 3.3V.Therefore, output resistance Rso and reception end resistance R6 is in NMOS bus In the case of switch IC, it is to deduct the amplitude of DC potential sdi signal from characteristic resistance Rz generally 75 Ω in transmission path 2 6 Ω of conducting resistance Rd～the value of 8 Ω average out to 7 Ω gained be 68 Ω, for Rz75 about Ω.
Therefore, output end resistance and NMOS bus switch IC conducting resistance aggregate value, receive end resistance and The characteristic impedance 75 in the transmission path of the aggregate value of conducting resistance, triple-concentric cable or the coaxial cable of NMOS bus switch IC Between Ω, error is about 1% roughly equal, and the wave distortion caused because of the reflection of impedance mismatching reduces.And then, in DC potential During amplitude 0.8Vp-p under the amplitude of sdi signal, the change of resistance value reduces about 2% relative to 75 Ω, the most asymmetrical Wave distortion reduces.
It addition, employ the feelings of the 5V capacitance bus switch of non-patent literature 9 in the simulation switch of Fig. 3 C and Fig. 3 D Under condition, conducting resistance Rd, according to positive voltage Vcc, is 4.8 Ω when 2.1V, is 4.3 Ω when 2.5V, at 2.7V～3.5V Time be 4.2 Ω.Therefore, conducting resistance Rd under positive supply Vcc is the amplitude of DC potential sdi signal during+2.5V is 4.8 Ω ～4.2 Ω, for average 4.5 Ω.Deduct Rd, 75-4.5=70.5 ≈ 71 ≈ 68+2.7 from Rz, be 68 Ω and the series connection of 2.7 Ω, Mean error relative to 75 Ω be 0.2 Ω be 0.3%, be the precision of below range of error, obtain impedance matching.Because reflection is made The wave distortion become is below range of error.And then, during amplitude 0.8Vp-p under the amplitude of DC potential sdi signal, electricity The change of resistance is about 0.8%p-p relative to 75 Ω, is reduced to below range of error, and upper and lower asymmetrical wave distortion is also for by mistake Below difference scope.
And then, have and receive that the conducting resistance of above-mentioned simulation switch of side is low and that signal waveform is not compressed letter The D10 of SBD of number ground connection that polarity of wave is compressed and being connected in series of resistance R11, by switch to not compression Signal is compressed, and obtains the upper and lower balance of signal waveform, by sdi signal reception equalizer or comprise waveform equalizer Receptor easily carry out reverting to the wave shape equalization of waveform when sending.As a result, even the cable extended also be able to into Row wave shape equalization.
It addition, utilize conducting resistance Rd of 5V low capacitance bus switch IC according to positive voltage perseverance when 2.7V～3.5V Be set to the situation of 4.2 Ω, use 5V low capacitance bus switch, and if then set when positive voltage Vcc is for+3.2V Vee as- 1.3V～-2.3V, then conducting resistance Rd under the 0.8Vp-p of the sdi signal of earthing potential is constant is 4.2 Ω, does not has resistance value Change, there is no upper and lower asymmetrical wave distortion.Therefore, there is no need to upper and lower asymmetrical wave distortion correction D10 and R11, disconnects D10 or R11.
And then, Rso=R6=Rz-Rd=75-4.2=70.8 ≈ 71 ≈ 68+2.7, if Rso and R6 is set to 68 Ω with The series connection of 2.7 Ω, then the error relative to Rz75 Ω is 0.1 Ω, is 0.1%, almost without.That is, cause almost without because of reflection Wave distortion.
That is, Fig. 3 C of Fig. 6 of the block diagram of existing drive circuit, waveform equalizer, switch and embodiments of the invention 2 With the difference between the block diagram of the drive circuit of one embodiment of the invention of Fig. 3 D, waveform equalizer, switch is, to mould Intend NMOS bus switch or the supply voltage of IC of 5V low capacitance bus switch, the output resistance Rso of switch and receive end Resistance R6 is adjusted, the waveform reduce the wave distortion because the reflection of impedance mismatching causes, causing because of the change of resistance value Asymmetric distortion.Relative to existing drive circuit, waveform equalizer, Fig. 7 of input-output wave shape figure of switch The significant situation of asymmetric distortion of Vrin, the drive circuit of one embodiment of the invention, the input and output ripple of waveform equalizer The asymmetric distortion reduction of the Vrin of Fig. 4 D of shape figure.Therefore, easily carry out sdi signal reception equalizer or to comprise waveform equal The wave shape equalization of the receptor of weighing apparatus, it is possible to extend cable length.
And then, the drive circuit of one embodiment of the invention of Fig. 3 C of embodiments of the invention 2, waveform equalizer, In the block diagram of switch, for extra long distance cable, by receive the conducting resistance of the above-mentioned simulation switch of side low and to letter Number SBD of ground connection that the signal waveform polarity that waveform is not compressed is compressed and being connected in series of resistance, to not over The signal waveform polarity of switch compression is compressed, and obtains the upper and lower balance of signal waveform.
Or, use 5V low capacitance bus switch, if positive supply Vcc is+3.2V, then the reflection because of Vrin of Fig. 4 D is made The wave distortion become and the asymmetric distortion caused because of the change of resistance value become below range of error.
As a result, relative to existing drive circuit, waveform equalizer, Fig. 7 of input-output wave shape figure of switch The significant situation of asymmetric distortion of Vrin, the drive circuit of one embodiment of the invention, waveform equalizer or to comprise waveform equal The asymmetric distortion of the Vrin of Fig. 4 C of the input-output wave shape figure of the receptor of weighing apparatus almost without, easily carry out wave shape equalization Device or comprise the wave shape equalization of receptor of waveform equalizer, for sdi signal, the HD-SDI letter of 1500Mbps of 270Mbps Number, even triple-concentric cable, common coaxial cable, it is also possible to carry out the transmission of extra long distance cable.
And then, if drive circuit, waveform equalizer or the receptor that comprises waveform equalizer are improved, then exist In the transmission of the sdi signal of the UHDTV of the sdi signal of the 3G of 2970Mbps, about 24000Mbps, even three core coaxial electrical Cable, common coaxial cable, it is also possible to be transmitted with the cable longer than prior art.
Embodiment 3
Omit the explanation of the part identical with embodiments of the invention 1.
The amplifying circuit of one embodiment of the present of invention of Fig. 3 A of embodiments of the invention 1 and the block diagram of switch and this The amplifying circuit of one embodiment of the present of invention of Fig. 3 E and Fig. 3 F of inventive embodiment 3, switch block diagram between not With being, the resistance R14 sending amplifying circuit of Fig. 3 A is changed to the ferrite magnetic sending amplifying circuit of Fig. 3 E and Fig. 3 F Ring Z2.And then, relative to being the group being connected in series of Schottky-barrier diode D10 and resistance R11 in figure 3 a, in fig. 3e Add the group being connected in series of Schottky-barrier diode D11 and resistance R12, be Schottky-barrier diode D11 in Fig. 3 F The group being connected in series with resistance R12.The positive result electricity of Schottky-barrier diode D10 and Schottky-barrier diode D11 Pressure characteristic is different.
The positive supply Vcc of the supply voltage of the 5V low capacitance bus switch IC of simulation switch is set to more than+2.9V, just Poor Vab between power Vcc and negative supply Vee is more than 4.5V, below 5.5V, makes have enough and to spare by signal amplitude, it is allowed to Crossing of sending side is rushed.Fig. 8 B of the ideograph of the on-resistance characteristics of IC is switched such as the low capacitance bus of one embodiment of the invention Like that, it is allowed to conducting resistance 3.8 Ω of negative supply Vee and the 2.2Vp-according to conducting resistance 4.8 Ω that positive supply Vcc is 2.3V P passes through signal amplitude.And then, in the case of the length length of cable 2, use ferrite bead Z2 to allow in sending side Punching, also makes in sending side the low-frequency component of below fundamental frequency decay, strengthens the higher harmonic component of more than three times.And then, tool The conducting resistance having a low capacitance bus switch IC of sending side is low and that do not compressed signal waveform signal waveform polarity is entered The Schottky-barrier diode of the ground connection of row compression switchs the conducting of IC with the low capacitance bus being connected in series, receiving side of resistance Resistance is low and the Schottky-barrier diode of ground connection that do not compressed signal waveform signal waveform polarity is compressed with Being connected in series of resistance, is compressed the signal not having compression receiving side and sending side, obtains the upper and lower of signal waveform Balance.
If the change of the conducting resistance of low capacitance bus switch IC reduces, then need not receiving what side was not compressed Schottky-barrier diode D10 that signal is compressed and resistance R11, can be Schottky-barrier diode D11 and resistance R12 Be connected in series one group.
Application in industry
As embodiments of the invention 1～embodiment 3 application industrially, the more than transmission of triple-concentric cable Ultra long haul ionization, even the HD-SDI signal of the sdi signal of 270Mbps, 1500Mbps, common coaxial cable also be able to into The transmission of row extra long distance cable, therefore, even if in the coaxial overlap of the supervision purposes overlapped by power supply in SDI signal of video signal In, the most easily carry out ultra long haul ionization.Especially when being overlapped in signal of video signal by constant voltage source, easily carry out extra long distance Change.
Symbol description
1: image pickup part；2: triple-concentric cable；3: control portion；101: camera lens part；102: imaging apparatus；103,129,141: A/D changer (ADC)；104,127,204,217: digital signal processing section；105,136: image compression portion；106: switching part； 112,121: two-way portion；107,135: encoding section；116,125: lsb decoder；114,128,139,140:D/A changer (DAC)； 108,109,133,134: enlarging section；138,139,238,239: drive circuit；113,130:CPU；115,126: image stretches Portion；119,122,219,222: waveform equalizer or comprise the receptor of waveform equalizer；211,215: wave filter；120,142: Joint；208,209,222,224: multiplexing portion；210,216: time-division two-way switching part；IC1, IC3: operational amplifier or fortune Calculate amplifier and current buffer；IC2, IC5: simulation switch；IC4: simulation switch；Z1～Z2: ferrite bead；C1～ C14, Co: electric capacity；D10, D11: Schottky-barrier diode (SBD)；Ro: output resistance；Rso: output end resistance；R1～ R7, R11, R12: resistance；Rz: the characteristic impedance resistance in transmission path；Rd: the meansigma methods of the conducting resistance of simulation switch； Vin: sending side input signal；Vso: sending side output signal；Vrin: receive side input signal；Vro: receive side and amplify output Signal；Vo: receive side output signal；Vcc: positive supply；Vee: negative supply.

Claims (7)

1. a signal of video signal multiplex transmission apparatus, it is via a transmission path, to comprising digitized image letter Number, the digital signal of acoustical signal, control signal carry out time-division two-way switching transmitting-receiving digital image signal multiplexing transmission Device, it is characterised in that
End in the both sides in above-mentioned transmission path has the IC of the simulation switch of switching time division multiplexing, is receiving side tool There are waveform equalizer or the receptor comprising waveform equalizer, set the positive supply Vcc of the supply voltage of above-mentioned simulation switch, So that the leading of the above-mentioned simulation switch of the above-mentioned digital signal comprising digitized signal of video signal, acoustical signal, control signal Less than the 1/10 of the characteristic impedance resistance Rz that meansigma methods is above-mentioned transmission path of energising resistance, and above-mentioned comprise digitized shadow Image signal, acoustical signal, control signal digital signal above-mentioned simulation switch conducting resistance be changed to above-mentioned transmission Less than the 1/30 of the characteristic impedance resistance Rz in path,
For the characteristic impedance resistance Rz in above-mentioned transmission path, possess at least one unit following:
The unit that the increase of the end resistance caused because of the conducting resistance of above-mentioned simulation switch is modified；
To the signal waveform caused by the deviation of the end resistance that the change of the conducting resistance because of above-mentioned simulation switch causes The unit that distortion is modified.
2. a signal of video signal multiplex transmission apparatus, it is via a transmission path, to comprising digitized image letter Number, the digital signal of acoustical signal, control signal carry out time-division two-way switching transmitting-receiving digital image signal multiplexing transmission Device, it is characterised in that
End in the both sides in above-mentioned transmission path has the NMOS bus switch of the simulation switch of switching time division multiplexing IC, has waveform equalizer or the receptor comprising waveform equalizer, by the NMOS bus of above-mentioned simulation switch receiving side The positive supply Vcc of the supply voltage of switch IC is set to more than+2.9V, and by the poor Vab between positive supply Vcc and negative supply Vee It is set to more than 4.5V below 5.5V, or, the end in the both sides in above-mentioned transmission path has the mould of switching time division multiplexing Intend the 5V low capacitance bus switch IC of switch, receiving side, there is waveform equalizer or the receptor comprising waveform equalizer, The positive supply Vcc of the supply voltage that the low capacitance bus of 5V of above-mentioned simulation switch is switched IC is set to more than+2.5V, and will just Poor Vab between power Vcc and negative supply Vee is set to more than 4.5V below 5.5V,
For the characteristic impedance resistance Rz in above-mentioned transmission path, possess at least one unit following:
The unit that the increase of the end resistance caused because of the conducting resistance of above-mentioned simulation switch is modified；
To the signal waveform caused by the deviation of the end resistance that the change of the conducting resistance because of above-mentioned simulation switch causes The unit that distortion is modified.
Signal of video signal multiplex transmission apparatus the most according to claim 2, it is characterised in that
There is following at least one:
For making the above-mentioned simulation switch of the above-mentioned digital signal comprising digitized signal of video signal, acoustical signal, control signal Bus switch IC conducting resistance the characteristic impedance resistance Rz being changed to above-mentioned transmission path less than 1/100, set The bus switch IC of the above-mentioned simulation switch of the positive supply Vcc of the supply voltage of the bus switch IC of above-mentioned simulation switch；
The meansigma methods Rd institute of the conducting resistance of above-mentioned simulation switch is deducted from the characteristic impedance resistance Rz in above-mentioned transmission path The end resistance of resistance value Rz-Rd obtained；
Low signal waveform polarity is pressed of conducting resistance of the above-mentioned simulation switch receiving side of above-mentioned simulation switch The Schottky-barrier diode of ground connection of contracting and being connected in series of resistance.
4. according to the signal of video signal multiplex transmission apparatus described in any one of claims 1 to 3, it is characterised in that
Have: amplifier, its before the waveform equalizer receiving side or the receptor comprising waveform equalizer to above-mentioned numeral The waveform of signal is amplified；And
Impedance body, it is expressed as compared with the circuit characteristic resistance of the amplifier being amplified the waveform of above-mentioned digital signal, The impedance of the clock fundamental frequency of the waveform of above-mentioned digital signal is low, the clock order harmonic frequencies of the waveform of above-mentioned digital signal High inductance, capacitor and the resistance of impedance the circuit being connected in parallel connection in series with a resistor after circuit approximation etc. Valency circuit,
Carry out following at least one party:
Make to above-mentioned waveform equalizer or the receptor input that comprises waveform equalizer, the clock of the waveform of above-mentioned digital signal Low-frequency component decay below fundamental frequency, strengthens the clock higher harmonic component of the waveform of above-mentioned digital signal, passes through Xiao Te The signal amplitude of negative direction is compressed in above-mentioned simulation switch by base barrier diode and resistance；
Or, about the supply voltage of the 5V low capacitance bus switch IC of above-mentioned simulation switch, when positive supply Vcc is 3.2V The poor Vab being set between positive supply Vcc and negative supply Vee by negative supply Vee is at more than 4.5V below 5.5V.
Signal of video signal multiplex transmission apparatus the most according to claim 4, it is characterised in that
Having: amplifier, the waveform of above-mentioned digital signal was amplified before the above-mentioned simulation switch of sending side by it；With And
Above-mentioned impedance body,
Make the low of below clock fundamental frequency that the above-mentioned simulation switch to sending side inputs, above-mentioned digital signal waveform Frequently composition decay, strengthens the clock higher harmonic component of the waveform of above-mentioned digital signal.
6. a signal of video signal multiplex transmission apparatus, it is via a transmission path, to comprising digitized image letter Number, the digital signal of acoustical signal, control signal carry out time-division two-way switching transmitting-receiving digital image signal multiplexing transmission Device, it is characterised in that
End in the both sides in above-mentioned transmission path has the bus switch IC of the simulation switch of switching time division multiplexing, Receive side and there is waveform equalizer or the receptor comprising waveform equalizer, for the above-mentioned transmission path in above-mentioned transmission path Characteristic impedance resistance,
Possess at least one unit following:
The list that the increase of the end resistance that the conducting resistance of the bus switch IC because of above-mentioned simulation switch causes is modified Unit；
To caused by the deviation of the end resistance that the change of the conducting resistance of the bus switch IC because of above-mentioned simulation switch causes The unit that is modified of the distortion of signal waveform.
7. a camera head, it is characterised in that
Possess: there is imaging apparatus, signal of video signal process portion, the image pickup part of CPU；
The signal of video signal multiplex transmission apparatus of the transmitting device described in any one of claim 1 to 5；And
There is signal of video signal process portion, signal of video signal input and output portion, the control portion of CPU,
Signal of video signal is carried out time-division two-way multiplexing transmission.
CN201280017804.1A 2011-02-17 2012-02-10 Signal of video signal multiplex transmission apparatus and the camera head possessing it Active CN103477622B (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2011-032056 2011-02-17
JP2011032056 2011-02-17
PCT/JP2012/053112 WO2012111557A1 (en) 2011-02-17 2012-02-10 Video-signal multiplex-transmission apparatus and image-pickup apparatus provided with same

Publications (2)

Publication Number Publication Date
CN103477622A CN103477622A (en) 2013-12-25
CN103477622B true CN103477622B (en) 2016-08-17

Family

ID=46672482

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201280017804.1A Active CN103477622B (en) 2011-02-17 2012-02-10 Signal of video signal multiplex transmission apparatus and the camera head possessing it

Country Status (3)

Country Link
JP (1) JP5907749B2 (en)
CN (1) CN103477622B (en)
WO (1) WO2012111557A1 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6431662B2 (en) * 2013-09-24 2018-11-28 Ｄｘアンテナ株式会社 Signal processing apparatus and signal processing system
CN104954725B (en) * 2015-06-16 2017-12-26 广州市奥威亚电子科技有限公司 A kind of two-way assistance data method of transmission based on SDI
JP6494055B2 (en) * 2015-10-30 2019-04-03 株式会社日立国際電気 Transmission equipment
CN109738087B (en) * 2019-03-07 2023-12-19 深圳市拓普瑞电子有限公司 Multichannel three-wire system thermal resistance measuring system and method

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1048777A (en) * 1989-04-28 1991-01-23 亚特兰大科研公司 The scan converter that is used for high-definition television system
CN1645909A (en) * 1997-08-27 2005-07-27 松下电器产业株式会社 Control information generating apparatus for broadcast system
CN101965232A (en) * 2008-01-09 2011-02-02 海浪科技有限公司 Multiple frequency band acoustic transducer arrays

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05300022A (en) * 1992-04-20 1993-11-12 Matsushita Electric Ind Co Ltd Comparator and a/d converter using it
JPH07320209A (en) * 1994-05-26 1995-12-08 Konica Corp Magnetic writing device
JP2000307572A (en) * 1999-04-16 2000-11-02 Fujitsu Ltd Lt-nt long distance transmission system and its equipment
JP4559151B2 (en) * 2004-07-29 2010-10-06 富士通株式会社 Termination circuit, semiconductor device, and electronic device
JP4822475B2 (en) * 2006-07-20 2011-11-24 株式会社日立国際電気 Video signal transmission device
JP4814803B2 (en) * 2007-01-12 2011-11-16 富士通株式会社 Bidirectional control device using remote control signal by computer and home appliance
JP5351622B2 (en) * 2008-06-11 2013-11-27 株式会社日立国際電気 A video signal multiplex transmission device and an imaging device using the video signal multiplex transmission device.

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1048777A (en) * 1989-04-28 1991-01-23 亚特兰大科研公司 The scan converter that is used for high-definition television system
CN1645909A (en) * 1997-08-27 2005-07-27 松下电器产业株式会社 Control information generating apparatus for broadcast system
CN101965232A (en) * 2008-01-09 2011-02-02 海浪科技有限公司 Multiple frequency band acoustic transducer arrays

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
利用光纤进行多路数据与视频图像信息混合传输;韩红霞，郭劲，曹立华，耿爱辉;《光学精密工程》;20051130;第13卷;全文 *

Also Published As

Publication number Publication date
CN103477622A (en) 2013-12-25
WO2012111557A1 (en) 2012-08-23
JP5907749B2 (en) 2016-04-26
JP2012186800A (en) 2012-09-27

Similar Documents

Publication Publication Date Title
CN103477622B (en) Signal of video signal multiplex transmission apparatus and the camera head possessing it
US8897178B2 (en) Asymmetric full duplex communication including device power communication
US7047556B2 (en) Method and apparatus for equalizing video transmitted over twisted pair cable
CN104125434B (en) A kind of system of long range high definition transmission
CN102572520A (en) Image processing device, image reproduction device, and image reproduction system
JP2009055306A (en) Data receiver
US20180296065A1 (en) Endoscope device
US8737521B2 (en) Signal conversion during transmission of serial data streams
CN102186073A (en) HD-SDI (High Definition-Serial Digital Interface) video signal transmission system and method in high-speed dome camera
CN105659132A (en) Methods, circuits and optical cable assemblies for optical transmission of high-speed data and low-speed data
CN103731694B (en) A kind of Vehicular satellite television broadcasting system and method based on MOST networks
CN102714507A (en) Systems and methods for interfacing a white space device with a host device
CN103763608A (en) Head-wearing audio and video device, audio and video transmission system and audio and video transmission method
CN103686258A (en) Set top box and method for detecting interference signals of set top box
EP2660990B1 (en) Asymmetric full duplex communication with high tolerance for coax characteristic impedance
CN205283689U (en) MIPI camera lens transmission distance extension fixture
JP5351622B2 (en) A video signal multiplex transmission device and an imaging device using the video signal multiplex transmission device.
TW201301890A (en) Signal transmitting apparatus and transmitter and receiver thereof
JP2010166472A (en) Differential signal drive circuit and differential signal transmission system
CN203406970U (en) Audio/video transmission system
JP2004517533A (en) DVB-ASI signal inversion adapter and inversion system
CN202353733U (en) Video sharing equipment and system
CN107071304A (en) One kind use surpasses 5 class netting twines and realizes VGA signals and multiplexing and distributor and method
CN205666830U (en) Wireless communication device
CN204291249U (en) HD-SDI optical transmitter and receiver circuit

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant