CN1048376C - Digital type colour television signal synthesizer - Google Patents
Digital type colour television signal synthesizer Download PDFInfo
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- CN1048376C CN1048376C CN95118300A CN95118300A CN1048376C CN 1048376 C CN1048376 C CN 1048376C CN 95118300 A CN95118300 A CN 95118300A CN 95118300 A CN95118300 A CN 95118300A CN 1048376 C CN1048376 C CN 1048376C
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Abstract
The present invention discloses a digital color television signal synthesizer. An image signal synthesis circuit composed of an addition circuit, two sets of positive and negative inverter circuits for controlling, and a set of carrier synthesis circuit synthesizes a luminance signal and two sets of color difference signals into an image signal; then, synchronous signals and reference color synchronous pulse signals are added by a synchronous synthesis circuit; color synthesis signals are output after the synchronous signals and the reference color synchronous pulse signals pass through a digital-to-analog converter. The present invention has the advantage that the digital color television signal synthesizer does not need to realize the hardware of a lot of circuits, such as multipliers, sine and cosine wave generators, etc.
Description
The present invention relates to a kind of digital type colour television signal synthesizer, particularly a kind of colour television signal synthesizer of saving a large amount of hardware.
The composite signal of general color TV is by the luminance signal that comprises the image black and white (Y), formed according to the color difference signal behind the standard color carrier frequency phase modulation (I, Q), synchronizing signal, reference color synchronization pulse (color burst), and its synthetic block diagram is shown in Fig. 1.The synthetic square frame 1 of signal of video signal wherein synthesizes signal of video signal with brightness signal Y with according to color difference signal I and Q behind the standard color carrier frequency phase modulation by standard code, this signal adds synchronizing signal (Sync) and reference color synchronization pulses through synchronous combiner circuit 2, the more colored composite signal of output behind D-A converter 3.
Wherein, it is the most important problem of composite color signal that color difference signal correctly is tuned to the standard color carrier frequency, i.e. the work of the synthetic square frame of signal of video signal, and especially after digitlization, it needs maximum mathematical operations in whole digital combiner circuit.
Colour signal is to form by following formula modulation: Ey+Eicos (2 π f
CcT+33 °)+Eqsin (2 π f
CcT+33 °)---(1) wherein t is the time, and Ey is a luminance signal, and Ei and Eq are the sizes values of color difference signal, and fcc is the standard color carrier frequency of 3.579545 megahertzes (MHz);
As can be seen from the above equation, need the multiplier and the string wave producer of numeral to synthesize with digital form modulation color difference signal (I, Q).Notion according to this, directly synthetic mode can be finished by the square frame signal of Fig. 2, comprises two multipliers 4 and an adder 5 among the figure.It is too high that yet the shortcoming of this mode is a cost, and especially multiplier is very expensive in digital circuit.
Another feasible pattern is the phase place size of direct modulation colour carrier, according to this notion we can the aberration in the formula (1) partly be rewritten as:
Acos (2 π f
CcT+Phi+33 °)----(2) are wherein
A is (Ei Ei+Eq Eq);
Phi is arctan (Ei/Eq)
Synthesize because signal of video signal be a numeral, A and Phi can be found or obtained by the direct output of previous stage by form.Therefore can reduce required realization cost and only finish by a multiplier.
As shown in Figure 3, only need a multiplier 4 and an adder 5; But the realization cost of this mode is still high; On the other hand, because the change of phase place is directly relevant with the time, and digital signal is reference with common clock pulse all, and solve higher phase must have higher frequency.Therefore, the mode of this realization also can't solve a lot of phase signals in limited, selectable numerical frequency.
The present invention exports the square waves that two groups of phase differences are 90 degree by the carrier wave combiner circuit in the synthetic square frame of signal of video signal, whether enter positive and negative negative circuit anti-phase with the decision color difference signal, determines value after positive and negative to enter adder and the luminance signal addition obtains signal of video signal.Add synchronizing signal and reference color synchronization pulse through synchronous combiner circuit afterwards,, and export colored composite signal again through D-A converter.
The present invention is a kind of implementation that does not need multiplier can synthesize colored composite signal.Mainly be to utilize the distribution character of square wave on frequency spectrum, directly with square wave carrier signal as a reference.This distribution character is that the square wave of a fixed frequency only contains one, three, five on frequency spectrum ... harmonic wave Deng the odd number frequency multiplication, and the colour signal of frequency tripling can't cause interference to the luminance signal that transmits simultaneously with outside the appointment frequency range (6MHz) of composite signal.Therefore the present invention is a kind of implementation that does not need multiplier can synthesize colored composite signal, can go out composite signal by extremely low hardware costs modulation.
Technical scheme of the present invention is: a kind of by a picture intelligence combiner circuit, the digital type colour television signal synthesizer that one a synchronous combiner circuit and a D/A conversion circuit are formed, wherein synchronous combiner circuit has the output of an input connection layout picture signals combiner circuit, and there is other to be respectively synchronous signal input end and reference color synchronization pulse input by two inputs, the output of combiner circuit inserts the input of D/A conversion circuit synchronously, the picture intelligence combiner circuit is provided with a luminance signal input and two groups of color difference signal inputs, and the output of D/A conversion circuit is colored composite signal output; This digital type colour television signal synthesizer is characterised in that, described picture intelligence combiner circuit is the subcarrier synthesizer by two groups of out of phase carrier waves of an output, two groups of color difference signals of one control whether form by an anti-phase positive and negative negater circuit and an add circuit, two outputs of subcarrier synthesizer insert two control ends of positive negative sense circuit and two control ends of add circuit respectively, positive and negative negater circuit has the two group color difference signal inputs of two inputs as described picture intelligence combiner circuit, add circuit has the luminance signal input of an input as described picture intelligence combiner circuit, it has in addition two inputs insert from two outputs of positive and negative negater circuit, and an output of add circuit is as the output of described picture intelligence combiner circuit.
Described subcarrier synthesizer in the described picture intelligence combiner circuit is that two groups of phase differences of output are the subcarrier synthesizer of the square wave of 90 degree.
Described subcarrier synthesizer in the described picture intelligence combiner circuit is two groups of subcarrier synthesizers that all comprise the out of phase carrier wave of four kinds of position standards (± 1, ± 2) of output.
Two groups of color difference signals of a described control in the described picture intelligence combiner circuit whether be made up of two positive and negative negater circuits that separate by anti-phase positive and negative negater circuit, they respectively have an input respectively as one of two groups of color difference signal inputs of described picture intelligence combiner circuit, and they respectively have self a control end to close an output of device with described carrier wave respectively with an output and an input of described add circuit is connected.
Two groups of color difference signals of a described control in the described picture intelligence combiner circuit whether be made up of a positive and negative negater circuit and two delay circuits by anti-phase positive and negative negater circuit, one group of color difference signal input of described picture intelligence combiner circuit is directly transported to described add circuit after a delay circuit inserts this positive and negative negater circuit, another group color difference signal input of described picture intelligence combiner circuit directly inserts this positive and negative negater circuit after another delay circuit is transported to described add circuit, and the output of two groups of out of phase carrier waves of described subcarrier synthesizer inserts two control ends of this positive and negative negater circuit.
Below in conjunction with accompanying drawing the present invention and embodiment are made detailed description:
Description of drawings
Fig. 1 is for forming the block diagram of colored composite signal.
Fig. 2 is the illustrative circuitry that the direct existing signal of video signal that constitutes with multiplier and string wave generation circuit synthesizes square frame.
Fig. 3 is the illustrative circuitry square frame of direct modulation colour carrier amplitude and phase place.
Fig. 4 is a block diagram of the present invention.
Fig. 5 forms for the subcarrier synthesizer circuit of the synthetic square frame of signal of video signal among the present invention.
Fig. 6 forms for the positive and negative negative circuit of the synthetic square frame of signal of video signal among the present invention.
Fig. 7 forms for the add circuit of the synthetic square frame of signal of video signal among the present invention.
Fig. 8 is that the subcarrier synthesizer circuit of the synthetic square frame of signal of video signal in the second embodiment of the invention is formed.
Fig. 9 is that the positive and negative negative circuit of the synthetic square frame of signal of video signal in the second embodiment of the invention is formed.
Figure 10 is two carrier waves of the subcarrier synthesizer output of the synthetic square frame of signal of video signal in the second embodiment of the invention.
Figure 11 is the cardinal principle block diagram of third embodiment of the invention.
Among the figure 1 is the synthetic square frame of signal of video signal, and 2 is synchronous combiner circuit, and 3 is D-A converter, 4 is multiplier, and 5 is adder, and 6 is positive and negative negative circuit, 7 is add circuit, and 8 is subcarrier synthesizer, and 9 is D flip-flop, 10 is OR-gate, 11 is * 2 square frames, and 12 is delay circuit, and Sync is a synchronizing signal, fs is a sampling frequency, and fcc is the standard color carrier frequency.
Fig. 4 is a cardinal principle block diagram of the present invention.Export among the figure Ei, Eq via 6 decisions of positive and negative negative circuit whether positive and negative anti-phase after, output signal is P1, P2, again with brightness signal value (Y) via add circuit 7 additions, can obtain signal of video signal, add synchronizing signal and reference color synchronization pulses through synchronous combiner circuit 2 afterwards, through D-A converter 3, export colored composite signal again.And the control signal of positive and negative negative circuit 6 (P3, P4) among the figure, by subcarrier synthesizer 8 outputs.
Fig. 5 forms for the subcarrier synthesizer circuit of the synthetic square frame of signal of video signal among the present invention.Subcarrier synthesizer is made up of several D flip-flops 9.Subcarrier synthesizer 8 produces the square wave that two groups of phase differences are 90 degree, and frequency is fcc (its sampling frequency fs is 12 times fcc in the present embodiment), replaces the employed string ripple of traditional circuit standard colour carrier.Whether 0,1 two accurate position of square wave then is used for decision input color difference signal (I or Q) anti-phase.
Fig. 6 forms for the positive and negative negative circuit of the synthetic square frame of signal of video signal among the present invention.Whether it is anti-phase by 10 controls of several OR-gates, as realizing with two-symbol representation, positive and negatively anti-phasely is equivalent in the former numeral 0 and becomes 1,1 value that becomes after 0 and add 1 again.
Fig. 7 forms for the add circuit of the synthetic square frame of signal of video signal among the present invention, and it comprises two adders 5.The action of anti-phase addition then can be by finishing in the mode of carry input (P5, P6) in the add circuit.
Under identical frequency spectrum notion, square wave may extend to the stepped waveform of four kinds of accurate positions, still can obtain to be lower than relatively the circuit realization of traditional circuit cost.So in second embodiment of the invention, can use different subcarrier synthesizers and positive and negative negative circuit, comprise four kinds of position standards (± 1 and ± 2) equally but the carrier wave 1 and carrier wave 2 of out of phase by producing two, and each carrier wave is all represented this four kinds of position standards by two bits (bit).After carrier wave enters positive and negative negative circuit, (position is accurate to be represented with second bit at first to select the position standard through the control of two signal line, for example representing the position standard with bit value 0 is 1, it is 2 that bit value 1 is represented a position standard) and determine positive and negative anti-phase (positive and negatively the expression with first bit, for example just, bit value 1 representative negative 2) with bit value 0 representative.Carrier wave promptly can 0 and 1 liang of step voltage combination 01,00,10,11 expressions+2 ,+1 ,-1 ,-2 four kind of position standard.
Fig. 8 is that the subcarrier synthesizer circuit of the synthetic square frame of signal of video signal in the second embodiment of the invention is formed.Wherein 11 on the square frame of " * 2 " is to determine whether to want twice output: promptly select ± 1 or ± 2.
Fig. 9 is that the positive and negative negative circuit of the synthetic square frame of signal of video signal in the second embodiment of the invention is formed.Two carrier waves that the input signal of its control end (P3, P4) is produced by preceding carrier generator, output (P1, P2) then be color difference signal through the output that control signal (P3, P4) decision is positive and negative after reaching twice whether.
Figure 10 is two carrier waves of the subcarrier synthesizer output of the synthetic square frame of signal of video signal in the second embodiment of the invention.Two ripples all comprise four kinds of accurate positions, and two wave phases differ 90 degree.
Figure 11 is the cardinal principle block diagram of third embodiment of the invention.According to present embodiment, can realize that two positive negative circuit are with the shared circuit kit of time sharing shared mode.The color difference signal I that imports during implementation enters positive and negative negative circuit 6 again through a delay circuit 12 earlier, and staggering enters the time of positive and negative negative circuit 6 with color difference signal Q; Color difference signal Q is then first through a delay circuit 12 (P2) through the output of positive and negative negative circuit 6, enters add circuit 4 with color difference signal I simultaneously through the output (P1) of same positive and negative negative circuit again.All the other subcarrier synthesizers 8, the action of combiner circuit 2 and D-A converter 3 synchronously are still as the description of Fig. 4.
Claims (5)
1. one kind by a picture intelligence combiner circuit, the digital type colour television signal synthesizer that one a synchronous combiner circuit and a D/A conversion circuit are formed, wherein synchronous combiner circuit has the output of an input connection layout picture signals combiner circuit, and there is other to be respectively synchronous signal input end and reference color synchronization pulse input by two inputs, the output of combiner circuit inserts the input of D/A conversion circuit synchronously, the picture intelligence combiner circuit is provided with a luminance signal input and two groups of color difference signal inputs, and the output of D/A conversion circuit is colored composite signal output; This digital type colour television signal synthesizer is characterised in that, described picture intelligence combiner circuit is the subcarrier synthesizer by two groups of out of phase carrier waves of an output, two groups of color difference signals of one control whether form by an anti-phase positive and negative negater circuit and an add circuit, two outputs of subcarrier synthesizer insert two control ends of positive negative sense circuit and two control ends of add circuit respectively, positive and negative negater circuit has the two group color difference signal inputs of two inputs as described picture intelligence combiner circuit, add circuit has the luminance signal input of an input as described picture intelligence combiner circuit, it has in addition two inputs insert from two outputs of positive and negative negater circuit, and an output of add circuit is as the output of described picture intelligence combiner circuit.
2. according to the described digital type colour television signal synthesizer of claim 1, it is characterized in that the described subcarrier synthesizer in the described picture intelligence combiner circuit is that two groups of phase differences of output are the subcarrier synthesizer of the square wave of 90 degree.
3. according to the described digital type colour television signal synthesizer of claim 1, it is characterized in that the described subcarrier synthesizer in the described picture intelligence combiner circuit is two groups of subcarrier synthesizers that all comprise the out of phase carrier wave of four kinds of position standards (± 1, ± 2) of output.
4. according to the described digital type colour television signal synthesizer of claim 1, it is characterized in that, two groups of color difference signals of a described control in the described picture intelligence combiner circuit whether be made up of two positive and negative negater circuits that separate by anti-phase positive and negative negater circuit, they respectively have an input respectively as one of two groups of color difference signal inputs of described picture intelligence combiner circuit, and they respectively have self a control end to close an output of device with described carrier wave respectively with an output and an input of described add circuit is connected.
5. according to the described digital type colour television signal synthesizer of claim 1, it is characterized in that, two groups of color difference signals of a described control in the described picture intelligence combiner circuit whether be made up of a positive and negative negater circuit and two delay circuits by anti-phase positive and negative negater circuit, one group of color difference signal input of described picture intelligence combiner circuit is directly transported to described add circuit after a delay circuit inserts this positive and negative negater circuit, another group color difference signal input of described picture intelligence combiner circuit directly inserts this positive and negative negater circuit after another delay circuit is transported to described add circuit, and the output of two groups of out of phase carrier waves of described subcarrier synthesizer inserts two control ends of this positive and negative negater circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN95118300A CN1048376C (en) | 1995-12-19 | 1995-12-19 | Digital type colour television signal synthesizer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN95118300A CN1048376C (en) | 1995-12-19 | 1995-12-19 | Digital type colour television signal synthesizer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1152845A CN1152845A (en) | 1997-06-25 |
| CN1048376C true CN1048376C (en) | 2000-01-12 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN95118300A Expired - Fee Related CN1048376C (en) | 1995-12-19 | 1995-12-19 | Digital type colour television signal synthesizer |
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|---|---|
| CN (1) | CN1048376C (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2146823Y (en) * | 1992-12-07 | 1993-11-17 | 谢志铭 | Colour TV test picture generator |
-
1995
- 1995-12-19 CN CN95118300A patent/CN1048376C/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2146823Y (en) * | 1992-12-07 | 1993-11-17 | 谢志铭 | Colour TV test picture generator |
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| Publication number | Publication date |
|---|---|
| CN1152845A (en) | 1997-06-25 |
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Granted publication date: 20000112 Termination date: 20131219 |