CN100559833C - The device of synchronizing signal and its method in the separating video signal - Google Patents
The device of synchronizing signal and its method in the separating video signal Download PDFInfo
- Publication number
- CN100559833C CN100559833C CNB2007101028184A CN200710102818A CN100559833C CN 100559833 C CN100559833 C CN 100559833C CN B2007101028184 A CNB2007101028184 A CN B2007101028184A CN 200710102818 A CN200710102818 A CN 200710102818A CN 100559833 C CN100559833 C CN 100559833C
- Authority
- CN
- China
- Prior art keywords
- signal
- reference voltage
- current source
- interval
- coupled signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Synchronizing For Television (AREA)
Abstract
The device of synchronizing signal in a kind of separating video signal.Be used for receiving video signals to obtain a coupled signal.Level judging circuit receives coupled signal, and voltage and a plurality of reference voltage of coupled signal compared.Described reference voltage defines a plurality of reference voltages interval.One of described reference voltage interval is a preset reference voltage interval.Level judging circuit is exported one according to the pairing reference voltage of the minimum voltage interval of the coupled signal in the scheduled time section and is adjusted signal.Level adjusting circuit has a plurality of current sources, is used to receive adjust signal and control described current source according to this to adjust the DC level of coupled signal.Sync separator circuit then when the minimum voltage when coupled signal is positioned at the preset reference voltage interval in fact, is isolated synchronizing signal from coupled signal.
Description
Technical field
The present invention relates to device and its method of synchronizing signal in a kind of separation signal, and be particularly related to device and its method of synchronizing signal in a kind of separating video signal.
Background technology
Please refer to Fig. 1, it is the oscillogram of vision signal.Vision signal comprises synchronizing signal SYNC and data-signal Data.Data-signal Data is different with the level interval of synchronizing signal SYNC, usually data-signal Data presumable magnitude of voltage greater than the magnitude of voltage of synchronizing signal SYNC.For the receiver of vision signal, must earlier the synchronizing signal SYNC in the vision signal be separated, receiver could further produce pixel clock (Pixel Clock) according to the frequency of synchronizing signal SYNC, and handles vision signal.
When transmitting vision signal, the DC level that the output of transmitter and receiver can receive is inequality through regular meeting.Thus, the vision signal that receiver received may surpass the voltage range that receiver can normal running.Therefore, audio video synchronization separator in the past is earlier the vision signal that is received to be carried out capacitive coupling (AC coupling) earlier, so that the direct voltage between transmitter and the receiver is isolated.Then, utilize the video clamp circuit that the DC voltage level of the vision signal after being coupled is locked to required magnitude of voltage again.Then, because the level of the synchronizing signal SYNC of vision signal and data-signal Da t a is interval different, the audio video synchronization separator utilizes a comparator and reference voltage that the synchronizing signal SYNC in the vision signal is separated.
Yet, the design of video clamp circuit in the past is the vision signal of utilizing after the circuit loop of simulation fixes capacitive coupling, because analog circuit is had relatively high expectations for the precision of parameter, so this kind mode is subjected to the interference of IC technological factor easily and the DC level change occurs and the phenomenon of loop bandwidth drift.The bandwidth in loop can limit the frequency range of treatable synchronizing signal SYNC.In addition, utilize the circuit loop of simulation also to occur the loop problem of unstable easily, thereby increase the complexity in the design.Therefore, how can increase effectively the audio video synchronization separator the frequency range of treatable vision signal, and can improve the loop problem of unstable, be still a problem that waits to solve.
Summary of the invention
In view of this, purpose of the present invention is exactly device and its method of synchronizing signal in a kind of separating video signal is provided, and solving clamper loop circuit problem of unstable in the past, and can handle the vision signal of different frequency scope effectively.
According to purpose of the present invention, the device of synchronizing signal in a kind of separating video signal is proposed, be used to receive a vision signal, vision signal comprises a synchronous signal and a data-signal, data-signal is different with the level interval of synchronizing signal, and device comprises an electric capacity, a level judging circuit, a level adjusting circuit, a synchronous demultiplexing circuit.This electric capacity is used for receiving video signals, and vision signal is carried out capacitive coupling, to obtain a coupled signal.Level judging circuit is used to receive coupled signal, and voltage and a plurality of reference voltage of coupled signal compared.Described reference voltage defines a plurality of reference voltages interval.Described reference voltage interval is the preset reference voltage interval.Level judging circuit is exported one according to the pairing reference voltage of the minimum voltage interval of the coupled signal in the scheduled time section and is adjusted signal.The pairing reference voltage of minimum voltage interval is meant that minimum voltage is positioned at this preset reference voltage interval.Level adjusting circuit has a plurality of current sources, is used to receive adjust signal and control described current source according to this to adjust the DC level of coupled signal, till the minimum voltage of coupled signal is positioned at the preset reference voltage interval in fact.Sync separator circuit then is when being positioned at the preset reference voltage interval in fact in order to the minimum voltage when coupled signal, according to a separation reference voltage, to isolate synchronizing signal from coupled signal.Separate reference voltage and be adjacent to the preset reference voltage interval.
According to purpose of the present invention, the method of synchronizing signal in a kind of separating video signal is more proposed, be applicable to a display unit, display unit is used to receive a vision signal, vision signal comprises a synchronous signal and a data-signal, data-signal is different with the level interval of synchronizing signal, and the method comprises the following steps.At first, vision signal is carried out capacitive coupling, to obtain a coupled signal.Then, compare voltage and a plurality of reference voltage of coupled signal, a little reference voltages define a plurality of reference voltages interval, and one of a little reference voltage intervals are a preset reference voltage interval.Then, according to the interval adjustment signal that produces of the pairing reference voltage of the minimum voltage of the coupled signal in the scheduled time section.Then, according to adjusting signal to control a plurality of current sources, to adjust the DC level of coupled signal, till the minimum voltage of coupled signal is positioned at the preset reference voltage interval in fact.Afterwards, when the minimum voltage of coupled signal is positioned at the preset reference voltage interval in fact,, from coupled signal, isolate synchronizing signal, separate reference voltage and be adjacent to the preset reference voltage interval according to a separation reference voltage.
For above-mentioned purpose of the present invention, feature and advantage can be become apparent, a preferred embodiment cited below particularly, and conjunction with figs. are described in detail below.
Description of drawings
Fig. 1 shows the oscillogram of vision signal.
Fig. 2 shows the calcspar according to the device of synchronizing signal in the separating video signal of a preferred embodiment of the present invention.
Fig. 3 shows the example according to the detailed circuit diagram of the device of synchronizing signal in the separating video signal of preferred embodiment of the present invention.
Fig. 4 shows according to the reference voltage V1 to V4 of preferred embodiment of the present invention and adjusts signal S
AdjGraph of a relation.
Fig. 5 show according to preferred embodiment of the present invention operating control signal P1, period 1 signal S1 and second round signal S2 sequential chart.
Fig. 6 shows according to the circuit simulation of the device of synchronizing signal in the separating video signal of preferred embodiment of the present invention figure as a result.
The reference numeral explanation
10: the first comparators
20: the second comparators
30: the three comparators
40: the four comparators
50: the five comparators
60: the minimum value detecting unit
70: the minimum value record cell
80: reference voltage generator
210: electric capacity
220: level judging circuit
222: comparison circuit
224: the minimum value register
225: the video clamp circuit
230: level adjusting circuit
232: the coarse adjustment charging current source
234: the fine setting charging current source
236: fine setting discharging current source
238: coarse adjustment discharging current source
240: sync separator circuit
250: oscillator
260: cycle control circuit
Embodiment
Please refer to Fig. 2, it shows the calcspar according to the device of synchronizing signal in the separating video signal of a preferred embodiment of the present invention.The device 200 of synchronizing signal is arranged at display unit in the separating video signal, and LCD screen for example is in order to receiving video signals VS.Wherein, vision signal VS comprises synchronizing signal SYNC and data-signal Data, as shown in Figure 1.Device 200 comprises electric capacity 210, video clamp circuit 225 and sync separator circuit 240.Video clamp circuit 225 comprises level judging circuit 220 and level adjusting circuit 230.Electric capacity 210 is used for receiving video signals VS, and vision signal VS is carried out capacitive coupling (AC Coupling), to obtain coupled signal S
C
How the device 200 that next will describe synchronizing signal in the separating video signal in detail judges coupled signal S
CMinimum voltage whether be positioned at the preset reference voltage interval.Please refer to Fig. 3, it shows the example according to the detailed circuit diagram of the device of synchronizing signal in the separating video signal of preferred embodiment of the present invention.Level judging circuit 220 comprises comparison circuit 222 and minimum value register 224.Comparison circuit 222 comprises a plurality of comparators, for example comprises first comparator 10, second comparator 20, the 3rd comparator 30 and the 4th comparator 40. Comparator 10,20,30 and an end (for example being the positive input terminal of each comparator) of 40 receive coupled signal S respectively
CThe other end of first comparator 10 (for example being negative input end) receives the first reference voltage V1, and first comparator 10 is with the first reference voltage V1 and coupled signal S
CVoltage compare, to export the first index signal D1.The other end of second comparator 20 (for example being negative input end) receives the second reference voltage V2, and second comparator 20 is with the second reference voltage V2 and coupled signal S
CVoltage compare, to export the second index signal D2.The other end of the 3rd comparator 30 (for example being negative input end) receives the 3rd reference voltage V3, and the 3rd comparator 30 is with the 3rd reference voltage V3 and coupled signal S
CVoltage compare, to export the 3rd index signal D3.The other end of the 4th comparator 40 (for example being negative input end) receives the 4th reference voltage V4, and the 4th comparator 40 is with the 4th reference voltage V4 and coupled signal S
CVoltage compare, to export the 4th index signal D4.Wherein, V1＞V2＞V3＞V4.
As shown in Figure 4, reference voltage V1 to V4 defines the interval R1 to R5 of a plurality of reference voltages.The interval R1 of reference voltage is the interval of voltage greater than V1, the interval R2 of reference voltage is the interval of voltage between V1 and V2, the interval R3 of reference voltage is the interval of voltage between V2 and V3, the interval R4 of reference voltage is the interval of voltage between V3 and V4, and the interval R5 of reference voltage then is the interval of voltage less than V4.
As shown in Figure 3, minimum value register 224 comprises minimum value detecting unit 60 and minimum value record cell 70.Minimum value detecting unit 60 is used to receive the first index signal D1, the second index signal D2, the 3rd index signal D3 and the 4th index signal D4 to judge the pairing reference voltage of the voltage interval of coupled signal.Minimum value record cell 70 is used for the coupled signal S in the recording scheduled time section
CThe pairing reference voltage of minimum voltage interval, and signal S is adjusted in output according to this
AdjWherein, the preset reference voltage interval for example is the interval R3 of reference voltage.
Please refer to Fig. 4, it shows according to the reference voltage V1 to V4 of preferred embodiment of the present invention and adjusts signal S
AdjGraph of a relation.Adjust signal S
AdjFor example include the first discharge signal UP2, the second discharge signal UP1, locking signal Lock, the first charging signals DN1 and the second charging signals DN2.When the voltage of coupled signal Sc during greater than the first reference voltage V1, index signal D1～D4 all is activated.When the voltage of coupled signal Sc between the first reference voltage V1 and the second reference voltage V2, first index signal D1 forbidding, and index signal D2～D4 all is activated.When the voltage of coupled signal Sc between the second reference voltage V2 and the 3rd reference voltage V3, index signal D1～D2 forbidding, and index signal D3～D4 is activated.When the voltage of coupled signal Sc between the 3rd reference voltage V3 and the 4th reference voltage V4, index signal D1-D3 forbidding, and the 4th index signal D4 is activated.When the voltage of coupled signal Sc during less than the 4th reference voltage V4, index signal D1～D4 is all disabled.
Therefore, minimum value detecting unit 60 can be according to the state of index signal D1～D4, to learn this coupled signal S
CThe pairing reference voltage of voltage interval, its be the interval R1 to R5 of reference voltage one of them.Minimum value detecting unit 60 in the section, takes out a plurality of coupled signal S at the fixed time
CThe pairing reference voltage of voltage interval, and find out voltage reckling in these reference voltage intervals, be coupled signal S
CThe pairing reference voltage of minimum voltage interval.For instance, if minimum value detecting unit 60 at the fixed time in the section, takes out 10 coupled signal S
CThe words of the pairing reference voltage of voltage interval R1, R2, R1, R2, R3, R4, R4, R3, R1 and R2, because the voltage that the interval R4 of reference voltage is comprised is between the V3 to V4, be the reckling of the voltage that R1 to R4 comprised (more than the V4) that occurred, old friend's coupled signal S
CThe pairing reference voltage of minimum voltage interval be R4.
As coupled signal S
CThe pairing reference voltage of minimum voltage interval when being R1, the first discharge signal UP2 is activated.As coupled signal S
CThe pairing reference voltage of minimum voltage interval when being R2, the second discharge signal UP1 is activated.As coupled signal S
CThe pairing reference voltage of minimum voltage interval when being R 3, locking signal Lock is activated.As coupled signal S
CThe pairing reference voltage of minimum voltage interval when being R4, the first charging signals DN1 is activated.As coupled signal S
CThe pairing reference voltage of minimum voltage interval when being R5, the second charging signals DN2 is activated.
As shown in Figure 3, level adjusting circuit 230 more comprises coarse adjustment charging current source 232, fine setting charging current source 234, fine setting discharging current source 236 and coarse adjustment discharging current source 238.When the first discharge signal UP2 was activated, coarse adjustment discharging current source 238 was activated, to provide first discharging current as adjusting electric current I
Adj, to reduce coupled signal S
CDC level.When the second discharge signal UP1 was activated, fine setting discharging current source 236 was activated, to provide second discharging current as adjusting electric current I
Adj, to reduce coupled signal S
CDC level.When the first charging signals DN1 was activated, fine setting charging current source 234 was activated, to provide first charging current as adjusting electric current I
Adj, to improve coupled signal S
CDC level.When the second charging signals DN2 was activated, coarse adjustment charging current source 232 was activated, to provide second charging current as adjusting electric current I
Adj, to improve coupled signal S
CDC level.Wherein, the absolute value of second discharging current is less than the absolute value of first discharging current, and the absolute value of first charging current is in fact less than the absolute value of second charging current.
As coupled signal S
CMinimum voltage be positioned in fact outside the interval R3 of this preset reference voltage, that is be positioned in reference voltage interval R1, R2, R4 or the R5, adjust signal S
AdjAccording to coupled signal S
CThe pairing reference voltage of minimum voltage interval, optionally to enable fine setting discharging current source 236, fine setting one of charging current source 234, coarse adjustment discharging current source 238 and this coarse adjustment charging current source 232, to adjust coupled signal S
CDC level.
And as coupled signal S
CMinimum voltage be positioned in the interval R3 of preset reference voltage, locking signal Lock enables, the device 200 of synchronizing signal is the state that locks in the separating video signal, coupled signal S
CDC level need not adjust, so the time adjust signal S
AdjCan finely tune discharging current source 236, fine setting charging current source 234, coarse adjustment discharging current source 238 and coarse adjustment charging current source 232 by forbidding, and coupled signal S
CDC level will maintain original level in fact.
In addition, sync separator circuit 240 comprises separation comparator 50 and reference voltage generator 80.Separate comparator 50 in order to compare coupled signal S
CWith separate reference voltage V5.The device 200 of synchronizing signal is the state of locking in the separating video signal, that is coupled signal S
CMinimum voltage when being positioned at the interval R3 of preset reference voltage in fact, separate comparator 50 according to separating reference voltage V5, with from coupled signal S
CIn isolate synchronizing signal SYNC and output.Separate reference voltage V5 and be adjacent to the interval R3 of preset reference voltage.In the present embodiment, separate reference voltage V5 preferably greater than the arbitrary voltage in the interval R3 of preset reference voltage, that is greater than reference voltage V2.Reference voltage generator 80 is used to provide reference voltage V1～V4 and separates reference voltage V5.
Please refer to Fig. 5, its show according to preferred embodiment of the present invention operating control signal P1, period 1 signal S1 and second round signal S2 sequential chart.Audio video synchronization separator 200 more comprises oscillator 250 and cycle control circuit 260.Oscillator 250 is used to provide video synchronization device 200 required operating control signal P1.Cycle control circuit 260 is used to receive operating control signal P1, and with produce after the operating control signal P1 frequency reducing period 1 signal S1 and second round signal S2.Period 1, signal S1 was sent to minimum value detecting unit 60, and second round, signal S2 was sent to minimum value register 224.The minimum value detecting unit 60 of level judging circuit 220 is judged coupled signal S according to operating control signal P1
CThe pairing reference voltage of voltage interval.For example, when control signal P1 was rising edge, minimum value detecting unit 60 captured coupled signal S at that time
CThe pairing reference voltage of voltage interval.
The minimum value detecting unit 60 of level judging circuit 220 is according to the cycle decision scheduled time section of period 1 signal S1.For example, scheduled time section is the cycle Δ t of period 1 signal S1
1And in the rising edge of period 1 signal S1, minimum value detecting unit 60 determines coupled signal S by all reference voltage intervals of gained in the scheduled time section
CThe pairing reference voltage of minimum voltage interval.
The time span that current source 232,234,236,238 is activated is determined by the length of enabling time of signal S2 second round.For instance, if the second charging signals DN2 is for enabling, the time span that coarse adjustment charging current source 232 is enabled can be designed to equal Δ t
2That is, coarse adjustment charging current source 232 be the second charging signals DN2 be enable and second round signal S2 be for enabling under the situation of enabling.So, by making current source only at Δ t
2In enable, can make coupled signal S
CDirect voltage be unlikely too apace and change, and cause device 200 instabilities.Preferably, period 1 signal S1 and second round signal S2 frequency be lower than the frequency of synchronizing signal SYNC.
Please refer to Fig. 6, it shows according to the circuit simulation of the device of synchronizing signal in the separating video signal of preferred embodiment of the present invention figure as a result.Suppose that V1 is made as 60mV, V2 is made as 55mV, and V3 is made as 50mV, and V4 is made as 45mV, and V5 is made as 40mV.At first, the minimum voltage of coupled signal is about 85mV, the arbitrary voltage (50mV to 55mV) in the interval R3 of preset reference voltage, and greater than V1, so the first discharge signal UP2 is activated, level adjusting circuit 230 is adjusted electric current I according to the first discharge signal UP2 output that is activated
AdjWith to coupled signal S
CDC level adjust.Through after several cycles, the minimum voltage of coupled signal is reduced near the interval R3 of preset reference voltage, but still be a bit larger tham V2, and therefore the second discharge signal UP1 is activated, and level adjusting circuit 230 is according to the less adjustment electric current I of second discharge signal UP1 output that is activated
AdjWith to coupled signal S
CDC level finely tune.As shown in Figure 6, when the second discharge signal UP1 is activated, coupled signal S
CThe speed that descends of minimum voltage slow down.Pass through after several cycles coupled signal S again
CMinimum voltage between the interval R3 of preset reference voltage, so locking signal Lock is activated.At this moment, by sync separator circuit 240, synchronizing signal SYNC will successfully be separated.
The foregoing description is to illustrate it with the level judging circuit 220 that comprises four groups of comparators, so is not limited to this.
The device of synchronizing signal is in order to adjust the DC level of the vision signal after the capacitive coupling in the disclosed separating video signal of the above embodiment of the present invention, with the vision signal that received by after the capacitive coupling, compare with default reference voltage, and the pairing reference voltage of the capacity coupled minimum voltage interval of gained is recorded among the minimum value register after will comparing.Level adjusting circuit comes the DC level of coupled signal is adjusted according to the keeper of minimum value register institute.In addition, level adjusting circuit can have charging current source and the discharging current source that two kinds of different size of current can be provided, and therefore the DC level of coupled signal can be adjusted more accurately.Device of the present invention is not easy the error because of circuit technology, and produces the problem that can't accurately operate, and can reduce the unsettled phenomenon in loop.
In sum, though the present invention discloses as above with a preferred embodiment, so it is not in order to limit the present invention.The persond having ordinary knowledge in the technical field of the present invention, without departing from the spirit and scope of the present invention, when being used for a variety of modifications and variations.Therefore, protection scope of the present invention is as the criterion when looking the present patent application claim person of defining.
Claims (16)
1. the device of synchronizing signal in the separating video signal is used to receive a vision signal, and this vision signal comprises a synchronous signal and a data-signal, and this device comprises:
One electric capacity is used to receive this vision signal, and this vision signal is carried out capacitive coupling, to obtain a coupled signal;
One level judging circuit, be used to receive this coupled signal, and voltage and a plurality of reference voltage of this coupled signal compared, described reference voltage defines a plurality of reference voltages interval, described reference voltage interval is the preset reference voltage interval, this level judging circuit is exported one according to pairing this reference voltage interval of the minimum voltage of this coupled signal in the scheduled time section and is adjusted signal, and wherein the pairing reference voltage of minimum voltage interval is meant that minimum voltage is positioned at this preset reference voltage interval;
One level adjusting circuit in order to receiving this adjustment signal and to adjust the DC level of this coupled signal according to this, is positioned at this preset reference voltage interval in fact up to the minimum voltage of this coupled signal; And
One synchronous demultiplexing circuit is when being positioned at this preset reference voltage interval in fact in order to the minimum voltage when this coupled signal, according to a separation reference voltage, to isolate this synchronizing signal from this coupled signal.
2. device as claimed in claim 1, wherein, this level judging circuit comprises a reference voltage generator to produce described reference voltage and this separation reference voltage, this separation reference voltage is adjacent to this preset reference voltage interval.
3. device as claimed in claim 1, wherein, when the minimum voltage of this coupled signal during greater than the arbitrary voltage in this preset reference voltage interval, this adjustment signal is used to make this level adjusting circuit to reduce the DC level of this coupled signal; And when the minimum voltage of this coupled signal during less than the arbitrary voltage in this preset reference voltage interval, this adjustment signal is used to make this level adjusting circuit to improve the DC level of this coupled signal.
4. device as claimed in claim 1, wherein, this level judging circuit comprises:
One comparison circuit comprises a plurality of comparators, and an end of described comparator receives this coupled signal respectively, and the other end of described comparator receives described reference voltage respectively; And
One minimum value register, be used for output signal according to described comparator, with the pairing reference voltage of the voltage of judging this coupled signal interval, this minimum value register is more in order to pairing this reference voltage interval of the minimum voltage that writes down this coupled signal in this scheduled time section, and exports this adjustment signal according to this.
5. device as claimed in claim 1, wherein, this level adjusting circuit has a plurality of current sources, adjusting the DC level of this coupled signal, in fact is positioned at this preset reference voltage interval up to the minimum voltage of this coupled signal according to the described current source of this adjustment signal controlling.
6. device as claimed in claim 5, wherein, described current source comprises:
One fine setting discharging current source is in order to reduce the DC level of this coupled signal;
One fine setting charging current source is in order to improve the DC level of this coupled signal;
One coarse adjustment discharging current source is in order to reduce the DC level of this coupled signal; And
One coarse adjustment charging current source is in order to improve the DC level of this coupled signal;
Wherein, this adjusts signal according to pairing this reference voltage interval of the minimum voltage of this coupled signal, optionally to enable one of this fine setting discharging current source, this fine setting charging current source, this coarse adjustment discharging current source and this coarse adjustment charging current source;
Wherein, when the minimum voltage of this coupled signal is positioned in this preset reference voltage interval, this adjusts signal disables should fine setting discharging current source, this finely tunes charging current source, this coarse adjustment discharging current source and this coarse adjustment charging current source.
7. device as claimed in claim 1, wherein, this sync separator circuit comprises:
One separates comparator, is used for relatively that this coupled signal separates reference voltage to export this synchronizing signal with this, and this separates reference voltage in fact greater than the arbitrary voltage in this preset reference voltage interval.
8. device as claimed in claim 1 more comprises:
An operating control signal that provides this device required is provided one oscillator; And
One-period control circuit, be used for produce after this operating control signal frequency reducing a period 1 signal and one second round signal, this level judging circuit is judged pairing this reference voltage interval of voltage of this coupled signal according to this operating control signal, this level judging circuit determines this scheduled time section according to the cycle of this period 1 signal, and the time span that described current source is activated was determined by the enabling time of this of signal second round.
9. device as claimed in claim 8, wherein, this period 1 signal and this second round signal frequency be lower than the frequency of this synchronizing signal.
10. the method for synchronizing signal in the separating video signal is applicable to a display unit, and this display unit is used to receive a vision signal, and this vision signal comprises a synchronous signal and a data-signal, and this method comprises:
(a) this vision signal is carried out capacitive coupling, to obtain a coupled signal;
(b) the relatively voltage of this coupled signal and a plurality of reference voltage, described reference voltage defines a plurality of reference voltages interval, and one of described reference voltage interval is a preset reference voltage interval;
(c) according to the interval adjustment signal that produces of pairing this reference voltage of the minimum voltage of this coupled signal in the scheduled time section;
(d) according to this adjustment signal adjusting the DC level of this coupled signal, be positioned at this preset reference voltage interval in fact up to the minimum voltage of this coupled signal; And
(e) when the minimum voltage of this coupled signal is positioned at this preset reference voltage interval in fact,, from this coupled signal, isolate this synchronizing signal according to a separation reference voltage.
11. method as claimed in claim 10, wherein, when the minimum voltage of this coupled signal during greater than the arbitrary voltage in this preset reference voltage interval, reduce the DC level of this coupled signal, and, improve the DC level of this coupled signal when the minimum voltage of this coupled signal during less than the arbitrary voltage in this preset reference voltage interval.
12. method as claimed in claim 10 wherein, in this step (d), adjusting the DC level of this coupled signal, in fact is positioned at this preset reference voltage interval up to the minimum voltage of this coupled signal according to a plurality of current sources of this adjustment signal controlling.
13. method as claimed in claim 12, wherein, described current source comprises a fine setting discharging current source, a fine setting charging current source, a coarse adjustment discharging current source, reaches a coarse adjustment charging current source, this fine setting discharging current source is used to reduce the DC level of this coupled signal, this fine setting charging current source is used to improve the DC level of this coupled signal, this coarse adjustment discharging current source is used to reduce the DC level of this coupled signal, this coarse adjustment charging current source is used to improve the DC level of this coupled signal, and this step (d) comprising:
This adjusts signal according to pairing this reference voltage interval of the minimum voltage of this coupled signal, optionally to enable one of this fine setting discharging current source, this fine setting charging current source, this coarse adjustment discharging current source and this coarse adjustment charging current source; And
When the minimum voltage of this coupled signal is positioned in this preset reference voltage interval, this adjusts signal disables should fine setting discharging current source, this finely tunes charging current source, this coarse adjustment discharging current source and this coarse adjustment charging current source.
14. method as claimed in claim 10, wherein, this separates reference voltage in fact greater than the arbitrary voltage in this preset reference voltage interval, and this separation reference voltage is adjacent to this preset reference voltage interval.
15. method as claimed in claim 10 more comprises:
Produce an operating control signal;
This operating control signal of frequency reducing, with produce a period 1 signal and one second round signal;
Judge pairing this reference voltage interval of voltage of this coupled signal according to this operating control signal; And
Cycle according to this period 1 signal determines this scheduled time section;
Wherein, the time span that is activated of described current source with this second round signal enabling time relevant.
16. method as claimed in claim 15, wherein, this period 1 signal and this second round signal frequency be lower than the frequency of this synchronizing signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2007101028184A CN100559833C (en) | 2007-05-09 | 2007-05-09 | The device of synchronizing signal and its method in the separating video signal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2007101028184A CN100559833C (en) | 2007-05-09 | 2007-05-09 | The device of synchronizing signal and its method in the separating video signal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101304477A CN101304477A (en) | 2008-11-12 |
| CN100559833C true CN100559833C (en) | 2009-11-11 |
Family
ID=40114164
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2007101028184A Expired - Fee Related CN100559833C (en) | 2007-05-09 | 2007-05-09 | The device of synchronizing signal and its method in the separating video signal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100559833C (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8462269B2 (en) | 2007-11-16 | 2013-06-11 | Mediatek Inc. | Devices and methods for extracting a synchronization signal from a video signal |
| CN104749974B (en) * | 2013-12-30 | 2017-10-27 | 浙江大华技术股份有限公司 | A kind of method and device for obtaining comparison voltage signal and extracting reverse control signal |
| CN106303343A (en) * | 2015-05-29 | 2017-01-04 | 浙江大华技术股份有限公司 | The extraction element of a kind of reverse control signal and video data acquiring equipment |
| CN107426513B (en) * | 2017-07-25 | 2019-11-12 | 京东方科技集团股份有限公司 | CMOS active pixel sensor and its driving method |
| CN107888196B (en) * | 2017-12-08 | 2022-02-01 | 深圳市科陆电子科技股份有限公司 | Digital-to-analog conversion circuit |
-
2007
- 2007-05-09 CN CNB2007101028184A patent/CN100559833C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN101304477A (en) | 2008-11-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7535957B2 (en) | Transmitter circuit, receiver circuit, clock data recovery phase locked loop circuit, data transfer method and data transfer system | |
| CN100559833C (en) | The device of synchronizing signal and its method in the separating video signal | |
| KR100531469B1 (en) | Analog Delay Lock Loop with store circuit about delay lock | |
| US9147376B2 (en) | Display device and method | |
| US20070041483A1 (en) | Clock recovery circuit | |
| CN1085710A (en) | Demultiplexor circuit | |
| KR20140109131A (en) | Display interface for compressing/decompressing image data, method thereo, and device including the same | |
| CN100553148C (en) | Have improved phase-locked/phase-locked loop of release measuring ability | |
| US20060215296A1 (en) | Bidirectional referenceless communication circuit | |
| US11526136B2 (en) | Time-to-digital conversion circuit and source driver including the same | |
| US20010013801A1 (en) | Method for increasing the control bandwidth of a frequency control circuit | |
| US6559696B1 (en) | Circuit arrangement for generating a clock-pulse signal having a frequency synchronous with a reference clock-pulse signal | |
| US20080303565A1 (en) | Dll circuit and related method for avoiding stuck state and harmonic locking utilizing a frequency divider and an inverter | |
| EP1406390A1 (en) | PLL circuit and phase lock detector | |
| KR100297155B1 (en) | Over-sampling type clock recovery circuit and the method of adjusting phsaes of clock signals thereof | |
| US7463309B2 (en) | Data slicer for generating a reference voltage | |
| KR19990069339A (en) | Flat Panel Display with Automatic Tracking Adjustment | |
| US11303283B2 (en) | Clock and data recovery circuitry with asymmetrical charge pump | |
| KR20050012598A (en) | Method for detecting phase difference, and apparatus for performing the same | |
| US20210391974A1 (en) | Reception device and transmission and reception system | |
| US8199254B2 (en) | Device for separating synchronous signal and method thereof | |
| US7557864B2 (en) | Video signal judgment circuit | |
| US20020025015A1 (en) | Recovery circuit generating low jitter reproduction clock | |
| JP3165952B2 (en) | Digital automatic fine tuning circuit | |
| CN115664414A (en) | Clock data recovery circuit, processing chip and display device |
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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20091111 Termination date: 20200509 |