CN105810146B - Disappear shadow circuit and its control method, horizontal drive circuit and display screen - Google Patents
Disappear shadow circuit and its control method, horizontal drive circuit and display screen Download PDFInfo
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- CN105810146B CN105810146B CN201610324382.2A CN201610324382A CN105810146B CN 105810146 B CN105810146 B CN 105810146B CN 201610324382 A CN201610324382 A CN 201610324382A CN 105810146 B CN105810146 B CN 105810146B
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- horizontal drive
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
- G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
- G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2320/00—Control of display operating conditions
- G09G2320/02—Improving the quality of display appearance
- G09G2320/0257—Reduction of after-image effects
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
Abstract
Disappear shadow circuit and its control method, horizontal drive circuit and display screen the invention discloses one kind.Wherein, which includes：Observation circuit for receiving shutdown signal, and generates execution signal, wherein the horizontal drive circuit that shutdown signal is used to characterize display screen disconnects；Execution circuit is connect with the output end of observation circuit and horizontal drive circuit, and signal is executed for receiving, and executes drop-down potential operations, wherein drop-down potential operations are used to pull down the current potential of the output end of horizontal drive circuit.The present invention solves the drop-down low precision of pull-down circuit in the prior art and the technical problem that debugging cost is high.
Description
Technical field
The present invention relates to display area, disappear shadow circuit and its control method in particular to one kind, horizontal drive circuit
And display screen.
Background technology
Fig. 1 is a kind of structural schematic diagram of display screen according to prior art, as shown in Figure 1, LED display driver IC
It is broadly divided into line driving chip (PMOS tube, P-channel field-effect transistor (PEFT) transistor) and row driving chip (constant-current source), C1~C4 is to correspond to
Parasitic capacitance on line, LED display (being referred to as scan screen) are to show line by line when display, job order
Can be：
1, PMOS tube connects the first row and power supply (VDD) inside LED line driving chips, opens the first row and exports, and first
Capable voltage V_row1 is that the other row outputs of high level, i.e. V_row1=VDD, and LED line driving chips are high-impedance state.
2, LED array driving chip (constant-current source) opens the constant-current source of corresponding channel according to the data of the first row, lights first
Row LED light.
3, LED array driving chip (constant-current source) closes all output channels, closes the first row LED light, at this time all alignments
On voltage V_col1~V_col4=VDD-V_led, wherein V_led be LED light cut-in voltage.
4, LED line driving chips close the first row output, and the first row output is high-impedance state, because of the shadow of parasitic capacitance C1
It rings, the voltage V_row1 in the first row is maintained as high level, i.e. V_row1=VDD at this time.
5, PMOS tube connects the second row and power supply (VDD) inside LED line driving chips, opens the second row and exports, and second
Voltage V_row2=VDD on row.
6, LED array driving chip (constant-current source) opens the constant-current source of corresponding channel according to the data of the second row, lights second
Row LED light, because of the influence of parasitic capacitance C1, the voltage V_row1=VDD in the first row, so when constant-current source has just been opened
It waits, the LED light of the first row can also be lighted simultaneously, because the output of LED line driving chip the first rows is high-impedance state, the first row
The time that LED light is lit can be shorter, and display phenomenon is that the lamp of the first row can secretly bright (brightness is dark).
7, switching shows next line, repeats the step of the 3rd step~the 6th, every time when showing current line, a upper display line
LED light can be dark bright.
Because LED display typically progressively scans from top to bottom, display effect is upper the one of the row lighted
Guild has dark bright, this phenomenon is referred to as upper ghost in industry, or is row ghost.
In order to eliminate the upper ghost phenomenon of LED display, a variety of upper ghost circuits that disappear are devised in industry, basic skills is
Increase pull-down circuit, i.e., when every display line is completed, and closing rows drive (PMOS tube), the current potential of this journey is pulled down, this is made
Current potential on row reduces, and in this way when showing the LED light of next line, the LED light of this journey not can be lit.
Existing technical solution currently on the market, mainly metal-oxide-semiconductor pull-down scheme, be according to program adjust fall times come
Control drop-down current potential.Since display unit plate type in the market is various, the fall times constant phase on each display unit plate
Difference is very big, needs to each independent debugging routine of display unit plate, and because the parasitism on often going is electric on same cell board
Hold cause not of uniform size, the conducting resistance of the metal-oxide-semiconductor of drop-down is also inconsistent, so it is difficult to making the drop-down current potential of every row consistent.Therefore
The drop-down precision of existing scheme is poor and debugging cost is high.
For the high problem of the drop-down low precision and debugging cost of pull-down circuit in the prior art, not yet propose have at present
The solution of effect.
Invention content
Disappear shadow circuit and its control method, horizontal drive circuit and display screen an embodiment of the present invention provides one kind, at least
Solve the drop-down low precision of pull-down circuit in the prior art and the technical problem that debugging cost is high.
One side according to the ... of the embodiment of the present invention provides one kind and disappears shadow circuit, including：Observation circuit, for receiving
Shutdown signal, and generate execution signal, wherein the horizontal drive circuit that shutdown signal is used to characterize display screen disconnects；Execution circuit,
It is connect with the output end of observation circuit and horizontal drive circuit, executes signal for receiving, and execute drop-down potential operations, wherein
Drop-down potential operations are used to pull down the current potential of the output end of horizontal drive circuit.
Another aspect according to the ... of the embodiment of the present invention additionally provides a kind of control method for the shadow circuit that disappears, including：It is showing
After the horizontal drive circuit of screen disconnects, observation circuit receives shutdown signal, wherein shutdown signal is disconnected for characterizing horizontal drive circuit
It opens；Observation circuit, which generates, executes signal, and is sent to execution circuit by signal is executed；Execution circuit receive execute signal it
Afterwards, drop-down potential operations are executed, wherein drop-down potential operations are used to pull down the current potential of the output end of horizontal drive circuit.
Another aspect according to the ... of the embodiment of the present invention additionally provides a kind of horizontal drive circuit, including：Transistor, drain electrode with
Power supply connects, and source electrode accesses the output end of horizontal drive circuit；Observation circuit for receiving shutdown signal, and generates execution
Signal, wherein shutdown signal is for characterizing horizontal drive circuit disconnection；Execution circuit connects with the source electrode of observation circuit and transistor
It connects, executes signal for receiving, and execute drop-down potential operations, wherein drop-down potential operations are for pulling down horizontal drive circuit
The current potential of output end.
Another aspect according to the ... of the embodiment of the present invention additionally provides a kind of display screen, including：In the above embodiment of the present invention
The horizontal drive circuit of any one.
In embodiments of the present invention, the shutdown signal that horizontal drive circuit disconnects can be received by observation circuit, and generated
It executes signal and is sent to execution circuit, execution circuit executes drop-down potential operations, to realize according to the execution signal received
The purpose of the current potential of the output end of horizontal drive circuit is pulled down, and execution circuit executes drop-down potential operations, without passing through program
Adjustment fall times control drop-down current potential, to solve the drop-down low precision of pull-down circuit in the prior art and debugging at
This high-tech problem.Therefore, the scheme provided through the invention can realize drop-down current potential by observation circuit and execution circuit
The upper ghost phenomenon of display screen is eliminated in operation, improves drop-down current potential precision, and realization automatically controls, and reduces the effect of debugging cost.
Description of the drawings
Attached drawing described herein is used to provide further understanding of the present invention, and is constituted part of this application, this hair
Bright illustrative embodiments and their description are not constituted improper limitations of the present invention for explaining the present invention.In the accompanying drawings：
Fig. 1 is a kind of structural schematic diagram of display screen according to prior art；
Fig. 2 is a kind of schematic diagram of shadow circuit that disappears according to the ... of the embodiment of the present invention；
Fig. 3 is a kind of structural schematic diagram of optional shadow circuit that disappears according to the ... of the embodiment of the present invention；
Fig. 4 is a kind of flow chart of the control method of shadow circuit that disappears according to the ... of the embodiment of the present invention；And
Fig. 5 is a kind of schematic diagram of horizontal drive circuit according to the ... of the embodiment of the present invention.
Specific implementation mode
In order to enable those skilled in the art to better understand the solution of the present invention, below in conjunction in the embodiment of the present invention
Attached drawing, technical scheme in the embodiment of the invention is clearly and completely described, it is clear that described embodiment is only
The embodiment of a part of the invention, instead of all the embodiments.Based on the embodiments of the present invention, ordinary skill people
The every other embodiment that member is obtained without making creative work should all belong to the model that the present invention protects
It encloses.
It should be noted that term " first " in description and claims of this specification and above-mentioned attached drawing, "
Two " etc. be for distinguishing similar object, without being used to describe specific sequence or precedence.It should be appreciated that using in this way
Data can be interchanged in the appropriate case, so as to the embodiment of the present invention described herein can in addition to illustrating herein or
Sequence other than those of description is implemented.In addition, term " comprising " and " having " and their any deformation, it is intended that cover
It includes to be not necessarily limited to for example, containing the process of series of steps or unit, method, system, product or equipment to cover non-exclusive
Those of clearly list step or unit, but may include not listing clearly or for these processes, method, product
Or the other steps or unit that equipment is intrinsic.
Embodiment 1
According to embodiments of the present invention, it provides one kind to disappear shadow circuit embodiments, Fig. 2 is one kind according to the ... of the embodiment of the present invention
Disappear the schematic diagram of shadow circuit, as shown in Fig. 2, this disappears, shadow circuit includes：
Observation circuit 22 for receiving shutdown signal, and generates execution signal, wherein shutdown signal is shown for characterizing
The horizontal drive circuit 26 of screen disconnects.
Specifically, above-mentioned horizontal drive circuit can be line driving chip, it is not limited only to this, other points with driving function
The circuit that vertical component is combined into can also realize said program.Above-mentioned shutdown signal can be by the chip system of line driving chip
It sends.
Execution circuit 24 is connect with the output end of observation circuit 22 and horizontal drive circuit, executes signal for receiving, and hold
Row drop-down potential operations, wherein drop-down potential operations are used to pull down the current potential of the output end of horizontal drive circuit.
In a kind of optional scheme, after the line driving chip of display screen is closed, chip system can send closing
For signal to observation circuit, observation circuit can generate execution signal after receiving the shutdown signal, and by the execution signal
It is sent to execution circuit, execution circuit can start the output end for pulling down line driving chip after receiving execution signal
Current potential reduces the current potential of the row so that the voltage of the row is less than the cut-in voltage of the row LED light, in display next line
LED light when, the LED light of this journey not can be lit.
Fig. 3 is a kind of structural schematic diagram of optional shadow circuit that disappears according to the ... of the embodiment of the present invention, as shown in figure 3, the shadow that disappears
Circuit may include drop-down observation circuit (i.e. above-mentioned observation circuit) and pull-down circuit (i.e. above-mentioned execution circuit), drop-down electricity
Road is connected with the ends PD of drop-down observation circuit with the OUT terminal of line driving chip.After line driving chip closing, chip system is opened
DN signals are opened, DN=1, drop-down observation circuit is enabled to enable PD=0, and PD signals are sent to drop-down after receiving DN signals
Circuit, pull-down circuit are started to work after receiving PD signals, pull down OUT terminal current potential.
Above-described embodiment through the invention can receive the shutdown signal that horizontal drive circuit disconnects by observation circuit, and
It generating execution signal and is sent to execution circuit, execution circuit executes drop-down potential operations according to the execution signal received, to
The purpose of the current potential of the output end of drop-down horizontal drive circuit is realized, and execution circuit executes drop-down potential operations, without passing through
Program adjusts fall times to control drop-down current potential, to solve the drop-down low precision of pull-down circuit in the prior art and tune
Try technical problem of high cost.Therefore, the scheme provided through the invention can realize drop-down by observation circuit and execution circuit
Potential operations eliminate the upper ghost phenomenon of display screen, improve drop-down current potential precision, and realization automatically controls, and reduces debugging cost
Effect.
Optionally, in the above embodiment of the present invention, above-mentioned execution circuit includes：
The output end of amplifier, positive input and horizontal drive circuit connects, reverse input end access drop-down reference potential,
Control terminal and the first end of observation circuit connect, the current potential and drop-down reference potential of the output end for comparing horizontal drive circuit,
Obtain potential difference.
Specifically, above-mentioned drop-down reference potential can be provided by the chip system of line driving chip, it can be according to display screen
In the cut-in voltage of every row LED light set, when in order to ensure to show next line LED light, which will not be by point
It is bright, the cut-in voltage that drop-down reference potential is less than the row LED light can be set, such as could be provided as 1.2V, 2.5V or
3.5V。
The output end of the first transistor, grid and amplifier connects, and drain electrode is connect with the output end of horizontal drive circuit, source electrode
Ground connection, for being connected in the case where potential difference is more than or equal to preset potential difference.
Specifically, above-mentioned the first transistor can be N-channel field effect transistor, i.e. NMOS tube, above-mentioned preset potential is poor
Value can be the conducting potential difference of the first NMOS tube, i.e. potential difference between NMOS tube grid and source electrode.
In a kind of optional scheme, when the line driving chip of display screen is closed, chip system can send closing letter
Number observation circuit is given, observation circuit can generate execution signal after receiving the shutdown signal, and the execution signal is sent out
Amplifier is given, amplifier is started to work after receiving execution signal, by the current potential of the output end of line driving chip under
It draws reference potential to be compared, obtains potential difference, and be sent to the first transistor, be more than in the potential difference of amplifier output
In the case of conducting potential difference equal to the first NMOS tube, the first transistor conducting, the output end ground connection of line driving chip, output
The current potential at end is by quick pull-down.
As shown in figure 3, the positive input that pull-down circuit may include amplifier amp and NMOS tube NM0, amp can be with
The ends PD of drop-down observation circuit are connected with the OUT terminal of line driving chip, and reverse input end can access VR_pulldn, and amp is just
It is VFB to the current potential of input terminal, the current potential of the reverse input end of amp is VR_pulldn, and the current potential of the output end of amp is VG,
The grid of NM0 and the output end of amp connect, and drain electrode is connect with the OUT terminal of line driving chip, source electrode ground connection.As PD=0, amp
It starts to work, VFB=VDD, and VR_pulldn<VDD, so the VG of amp outputs is high potential, NM0 conductings start to pull down OUT
Terminal potential.
Through the above scheme, the current potential and drop-down reference potential of the output end of horizontal drive circuit, control are compared by amplifier
The first transistor processed conducting, to realize drop-down horizontal drive circuit output end current potential purpose.Pass through amplifier control the
One transistor can improve the precision of circuit drop-down.
Optionally, in the above embodiment of the present invention, the second end of observation circuit and the output end of amplifier connect, and are used for
In the case where potential difference is less than or equal to preset stopping potential value, stop signal is generated, stop signal executes electricity for controlling
Road stops executing drop-down potential operations.
Specifically, above-mentioned preset stopping potential value may be such that the first NMOS tube close to the potential value of shutdown.
In a kind of optional scheme, after the conducting of the first NMOS tube, the current potential of the output end of line driving chip can drop
It is low, drop-down reference potential is moved closer to, to which potential difference reduces, the potential difference of monitoring circuit monitors amplifier output, when
When potential difference makes the first NMOS tube almost close, determines and complete drop-down current potential, generate stop signal, stop execution circuit work
Make so that execution circuit stops executing drop-down potential operations.
As shown in figure 3, drop-down observation circuit can also be connect with the output end of amp.After opening NM0, the current potential of VFB is got over
Coming closer to VR_pulldn, the current potential of VG is lower and lower, when VG makes NM0 almost close, i.e. OUT=VFB=VR_
Pulldn completes drop-down, and by the current potential of drop-down monitoring circuit monitors VG, when completing to pull down, generates stop signal, enable
PD=1 closes amp and NM0, stops executing drop-down potential operations.
Through the above scheme, the potential difference that observation circuit is exported by monitor AMP, determines fall times, without logical
Cross program adjustment fall times reduces debugging cost to improve drop-down precision.
Optionally, in the above embodiment of the present invention, above-mentioned execution circuit further includes：Second transistor, grid and monitoring
The first end of circuit connects, and drain electrode is connect with the grid of the first transistor, source electrode ground connection, for receiving the stop signal, and
Generate cut-off signals, wherein cut-off signals are for controlling the first transistor shutdown.
Specifically, above-mentioned second transistor can be N-channel field effect transistor, i.e. NMOS tube.
In a kind of optional scheme, the second NMOS tube is after receiving stop signal, by stop signal and second
The conducting potential difference of NMOS tube is compared, if stop signal be more than or equal to the second NMOS tube conducting potential difference, second
NMOS tube is connected, and generates cut-off signals, reduces the first NMOS tube drain potential so that the first NMOS tube turns off, and completes drop-down row
The current potential of the output end of driving chip.
As shown in figure 3, second transistor can be NM1, drain electrode is connect with the output end of the source electrode of NM0 and amp, grid and
Pull down the ends the PD connection of observation circuit, source electrode ground connection.NM1 can be connected or be closed according to the PD signals of drop-down observation circuit
It is disconnected, when pulling down observation circuit output PD=0, NM1 shutdowns；When pulling down observation circuit output PD=1, NM1 conductings so that
NM0 is turned off, to provide cut-off signals for NM0.
Herein it should be noted that other modes can also be used to generate cut-off signals, to turn off the first transistor, this
Invention does not further limit this.
Optionally, in the above embodiment of the present invention, above-mentioned execution circuit further includes：Circuit is protected, driving of being expert at of connecting
It between the drain electrode of the output end and the first transistor of circuit, and is connect with the positive input of amplifier, is used for current limliting.
In a kind of optional scheme, protection circuit is arranged between the output end and the first NMOS tube of line driving chip,
It can play the role of pulling down current limliting, avoid pull-down current excessive, circuit components is caused to damage, influence the normal of shadow circuit that disappear
Work.Feedback Feedback points can also be set, cooperation amplifier adjustment drop-down waveform improves drop-down precision.
Optionally, in the above embodiment of the present invention, above-mentioned protection circuit includes：First resistor and second resistance, first
Resistance and second resistance series connection, the positive input connection of the connecting node and amplifier of first resistor and second resistance.
Specifically, the first resistor and the second electricity of corresponding resistance value according to the actual demand of current limliting and feedback point, can be selected
Resistance.
As shown in figure 3, first resistor can be the R1 in Fig. 3, second resistance can be R0, R1 and the R0 series connection in Fig. 3
Between the drain electrode of the OUT terminal and NM0 of line driving chip, the positive input of the connecting node and amplifier of R1 and R0 connects.
Through the above scheme, when the shadow circuit provided by the present invention that disappears works, pull-down circuit is only included, stability is not present
Problem can be improved drop-down precision by amplifier, and can design very high loop band under the area of very little and power consumption
Width, improve drop-down speed, to realize high-precision quick pull-down horizontal drive circuit output end current potential.
Embodiment 2
According to embodiments of the present invention, a kind of control method embodiment for the shadow circuit that disappears is provided, it should be noted that attached
The step of flow of figure illustrates can execute in the computer system of such as a group of computer-executable instructions, though also,
So logical order is shown in flow charts, but in some cases, it can be with different from shown by sequence execution herein
Or the step of description.
Fig. 4 is a kind of flow chart of the control method of shadow circuit that disappears according to the ... of the embodiment of the present invention, as shown in figure 4, the party
Method includes the following steps：
Step S42, after the horizontal drive circuit of display screen disconnects, observation circuit receives shutdown signal, wherein closes letter
Number for characterize horizontal drive circuit disconnection.
Specifically, above-mentioned horizontal drive circuit can be line driving chip, it is not limited only to this, other points with driving function
The circuit that vertical component is combined into can also realize said program.Above-mentioned shutdown signal can be by the chip system of line driving chip
It sends.
Step S44, observation circuit, which generates, executes signal, and is sent to execution circuit by signal is executed.
Step S46 executes drop-down potential operations after execution circuit receives and executes signal, wherein drop-down current potential behaviour
Act on the current potential of the output end of drop-down horizontal drive circuit.
In a kind of optional scheme, after the line driving chip of display screen is closed, chip system can send closing
For signal to observation circuit, observation circuit can generate execution signal after receiving the shutdown signal, and by the execution signal
It is sent to execution circuit, execution circuit can start the output end for pulling down line driving chip after receiving execution signal
Current potential reduces the current potential of the row so that the voltage of the row is less than the cut-in voltage of the row LED light, in display next line
LED light when, the LED light of this journey not can be lit.
Above-described embodiment through the invention can receive the shutdown signal that horizontal drive circuit disconnects by observation circuit, and
It generating execution signal and is sent to execution circuit, execution circuit executes drop-down potential operations according to the execution signal received, to
The purpose of the current potential of the output end of drop-down horizontal drive circuit is realized, and execution circuit executes drop-down potential operations, without passing through
Program adjusts fall times to control drop-down current potential, to solve the drop-down low precision of pull-down circuit in the prior art and tune
Try technical problem of high cost.Therefore, the scheme provided through the invention can realize drop-down by observation circuit and execution circuit
Potential operations eliminate the upper ghost phenomenon of display screen, improve drop-down current potential precision, and realization automatically controls, and reduces debugging cost
Effect.
Optionally, in the above embodiment of the present invention, step S46, execution circuit executes after receiving execution signal
Pulling down potential operations includes：
Step S462, the amplifier in execution circuit obtain drop-down reference potential.
Specifically, above-mentioned drop-down reference potential can be provided by the chip system of line driving chip, it can be according to display screen
In the cut-in voltage of every row LED light set, when in order to ensure to show next line LED light, which will not be by point
It is bright, the cut-in voltage that drop-down reference potential is less than the row LED light can be set, such as could be provided as 1.2V, 2.5V or
3.5V。
The current potential of the output end of horizontal drive circuit and drop-down reference potential are compared, obtain by step S464, amplifier
Potential difference, and potential difference is sent to the first transistor.
Step S466, the first transistor judge whether potential difference is more than or equal to preset potential difference.
Specifically, above-mentioned the first transistor can be N-channel field effect transistor, i.e. NMOS tube, above-mentioned preset potential is poor
Value can be the conducting potential difference of the first NMOS tube, i.e. potential difference between NMOS tube grid and source electrode.
Step S468, in the case where potential difference is more than or equal to preset potential difference, the first transistor is opened, to execute
Pull down potential operations.
In a kind of optional scheme, when the line driving chip of display screen is closed, chip system can send closing letter
Number observation circuit is given, observation circuit can generate execution signal after receiving the shutdown signal, and the execution signal is sent out
Amplifier is given, amplifier is started to work after receiving execution signal, by the current potential of the output end of line driving chip under
It draws reference potential to be compared, obtains potential difference, and be sent to the first transistor, be more than in the potential difference of amplifier output
In the case of conducting potential difference equal to the first NMOS tube, the first transistor conducting, the output end ground connection of line driving chip, output
The current potential at end is by quick pull-down.
Through the above scheme, the current potential and drop-down reference potential of the output end of horizontal drive circuit, control are compared by amplifier
The first transistor processed conducting, to realize drop-down horizontal drive circuit output end current potential purpose.Pass through amplifier control the
One transistor can improve the precision of circuit drop-down.
Optionally, in the above embodiment of the present invention, in step S464, amplifier is by the electricity of the output end of horizontal drive circuit
Position and drop-down reference potential are compared, and after obtaining potential difference, the above method further includes：
Potential difference is sent to observation circuit by step S482, amplifier.
Step S484, observation circuit judge whether potential difference is less than or equal to preset stopping potential value.
Specifically, above-mentioned preset stopping potential value may be such that the first NMOS tube close to the potential value of shutdown.
Step S486, in the case where potential difference is less than or equal to preset stopping potential value, observation circuit, which generates, stops letter
Number, and stop signal is sent to execution circuit.
Step S488, execution circuit stop executing drop-down potential operations after receiving stop signal.
In a kind of optional scheme, after the conducting of the first NMOS tube, the current potential of the output end of line driving chip can drop
It is low, drop-down reference potential is moved closer to, to which potential difference reduces, the potential difference of monitoring circuit monitors amplifier output, when
When potential difference makes the first NMOS tube almost close, determines and complete drop-down current potential, generate stop signal, stop execution circuit work
Make so that execution circuit stops executing drop-down potential operations.
Through the above scheme, the potential difference that observation circuit is exported by monitor AMP, determines fall times, without logical
Cross program adjustment fall times reduces debugging cost to improve drop-down precision.
Optionally, in the above embodiment of the present invention, step S488, execution circuit is stopped after receiving stop signal
Only executing drop-down potential operations includes：
Step S4882, amplifier are stopped.
Step S4884, the second transistor shutdown in execution circuit, and control the first transistor shutdown.
Specifically, above-mentioned second transistor can be N-channel field effect transistor, i.e. NMOS tube.
In a kind of optional scheme, amplifier is stopped after receiving stop signal；Second NMOS tube is connecing
After receiving stop signal, stop signal is compared with the conducting potential difference of the second NMOS tube, if stop signal is more than
Equal to the conducting potential difference of the second NMOS tube, then the second NMOS tube conducting generates cut-off signals, reduces the first NMOS tube drain electrode electricity
Position so that the first NMOS tube turns off, and completes the current potential of the output end of drop-down line driving chip.
Herein it should be noted that other modes can also be used to generate cut-off signals, to turn off the first transistor, this
Invention does not further limit this.
Embodiment 3
According to embodiments of the present invention, a kind of horizontal drive circuit embodiment is additionally provided, Fig. 5 is according to the ... of the embodiment of the present invention
A kind of schematic diagram of horizontal drive circuit, as shown in figure 5, the horizontal drive circuit includes：
Transistor 52, drain electrode are connect with power supply, and source electrode accesses the output end of horizontal drive circuit.
Specifically, above-mentioned horizontal drive circuit can be line driving chip, it is not limited only to this, other points with driving function
The circuit that vertical component is combined into can also realize said program.Above-mentioned transistor can be P-channel field-effect transistor (PEFT) transistor, i.e.,
PMOS tube.Above-mentioned power supply can be DC power supply VDD.
Observation circuit 22 for receiving shutdown signal, and generates execution signal, wherein shutdown signal is for characterizing capable drive
Dynamic circuit disconnects.
Specifically, above-mentioned shutdown signal can be sent by the chip system of line driving chip.
Execution circuit 24 is connect with the source electrode of observation circuit 22 and transistor 52, executes signal for receiving, and under execution
Draw potential operations, wherein drop-down potential operations are used to pull down the current potential of the output end of horizontal drive circuit.
In a kind of optional scheme, after the line driving chip of display screen is closed, chip system can send closing
For signal to observation circuit, observation circuit can generate execution signal after receiving the shutdown signal, and by the execution signal
It is sent to execution circuit, execution circuit can start the output end for pulling down line driving chip after receiving execution signal
Current potential reduces the current potential of the row so that the voltage of the row is less than the cut-in voltage of the row LED light, in display next line
LED light when, the LED light of this journey not can be lit.
As shown in figure 3, the line driving chip of display screen may include PMOS tube PM0, observation circuit (i.e. above-mentioned prison is pulled down
Slowdown monitoring circuit) and pull-down circuit (i.e. above-mentioned execution circuit), the drain electrode connection DC power supply VDD of PMOS tube, the source electrode of PMOS tube
OUT terminal is connected, OUT terminal can connect parasitic capacitance CL over the ground, the ends PD and row driving core of pull-down circuit and drop-down observation circuit
The OUT terminal of piece connects.It is closed in line driving chip, i.e., after the PM0 in line driving chip is closed, chip system opens DN letters
Number, enable DN=1, drop-down observation circuit enable PD=0, and PD signals are sent to pull-down circuit after receiving DN signals, under
Puller circuit is started to work after receiving PD signals, pulls down OUT terminal current potential.
Above-described embodiment through the invention can receive the shutdown signal that horizontal drive circuit disconnects by observation circuit, and
It generating execution signal and is sent to execution circuit, execution circuit executes drop-down potential operations according to the execution signal received, to
The purpose of the current potential of the output end of drop-down horizontal drive circuit is realized, and execution circuit executes drop-down potential operations, without passing through
Program adjusts fall times to control drop-down current potential, to solve the drop-down low precision of pull-down circuit in the prior art and tune
Try technical problem of high cost.Therefore, the scheme provided through the invention can realize drop-down by observation circuit and execution circuit
Potential operations eliminate the upper ghost phenomenon of display screen, improve drop-down current potential precision, and realization automatically controls, and reduces debugging cost
Effect.
Optionally, in the above embodiment of the present invention, above-mentioned execution circuit includes：
The source electrode of amplifier, positive input and transistor connects, reverse input end access drop-down reference potential, control terminal
It is connect with the first end of observation circuit, the current potential and drop-down reference potential of the output end for comparing horizontal drive circuit obtain electricity
Potential difference value.
Specifically, above-mentioned drop-down reference potential can be provided by the chip system of line driving chip, it can be according to display screen
In the cut-in voltage of every row LED light set, when in order to ensure to show next line LED light, which will not be by point
It is bright, the cut-in voltage that drop-down reference potential is less than the row LED light can be set, such as could be provided as 1.2V, 2.5V or
3.5V。
The output end of the first transistor, grid and amplifier connects, and drain electrode is connect with the source electrode of transistor, source electrode ground connection,
For being connected in the case where potential difference is more than or equal to preset potential difference.
Specifically, above-mentioned the first transistor can be N-channel field effect transistor, i.e. NMOS tube, above-mentioned preset potential is poor
Value can be the conducting potential difference of the first NMOS tube, i.e. potential difference between NMOS tube grid and source electrode.
In a kind of optional scheme, when the line driving chip of display screen is closed, chip system can send closing letter
Number observation circuit is given, observation circuit can generate execution signal after receiving the shutdown signal, and the execution signal is sent out
Amplifier is given, amplifier is started to work after receiving execution signal, by the current potential of the output end of line driving chip under
It draws reference potential to be compared, obtains potential difference, and be sent to the first transistor, be more than in the potential difference of amplifier output
In the case of conducting potential difference equal to the first NMOS tube, the first transistor conducting, the output end ground connection of line driving chip, output
The current potential at end is by quick pull-down.
As shown in figure 3, the positive input that pull-down circuit may include amplifier amp and NMOS tube NM0, amp can be with
The ends PD of drop-down observation circuit are connected with the source electrode of PM0, and reverse input end can access VR_pulldn, the positive input of amp
Current potential be VFB, the current potential of the reverse input end of amp is VR_pulldn, and the current potential of the output end of amp is VG, the grid of NM0
It is connect with the output end of amp, drain electrode is connect with the source electrode of PM0, source electrode ground connection.As PD=0, amp starts to work, VFB=
VDD, and VR_pulldn<VDD, so the VG of amp outputs is high potential, NM0 conductings start to pull down OUT terminal current potential.
Through the above scheme, the current potential and drop-down reference potential of the output end of horizontal drive circuit, control are compared by amplifier
The first transistor processed conducting, to realize drop-down horizontal drive circuit output end current potential purpose.Pass through amplifier control the
One transistor can improve the precision of circuit drop-down.
Herein it should be noted that in the horizontal drive circuit of actual displayed screen, including multiple transistors, each transistor
The output end of source electrode connection correspondence row can correspond to each transistor to realize the purpose of the often current potential of capable drop-down output end
One shadow circuit that disappears is set.
Embodiment 4
According to embodiments of the present invention, a kind of display screen embodiment is additionally provided, including any one in above-described embodiment
Horizontal drive circuit.
Specifically, above-mentioned horizontal drive circuit can be line driving chip, it is not limited only to this, other points with driving function
The circuit that vertical component is combined into can also realize said program.Above-mentioned display screen can be LED display, but be not limited only to
This.
Above-described embodiment through the invention can receive the shutdown signal that horizontal drive circuit disconnects by observation circuit, and
It generating execution signal and is sent to execution circuit, execution circuit executes drop-down potential operations according to the execution signal received, to
The purpose of the current potential of the output end of drop-down horizontal drive circuit is realized, and execution circuit executes drop-down potential operations, without passing through
Program adjusts fall times to control drop-down current potential, to solve the drop-down low precision of pull-down circuit in the prior art and tune
Try technical problem of high cost.Therefore, the scheme provided through the invention can realize drop-down by observation circuit and execution circuit
Potential operations eliminate the upper ghost phenomenon of display screen, improve drop-down current potential precision, and realization automatically controls, and reduces debugging cost
Effect.
The embodiments of the present invention are for illustration only, can not represent the quality of embodiment.
In the above embodiment of the present invention, all emphasizes particularly on different fields to the description of each embodiment, do not have in some embodiment
The part of detailed description may refer to the associated description of other embodiment.
In several embodiments provided herein, it should be understood that disclosed technology contents can pass through others
Mode is realized.Wherein, the apparatus embodiments described above are merely exemplary, for example, the unit division, Ke Yiwei
A kind of division of logic function, formula that in actual implementation, there may be another division manner, such as multiple units or component can combine or
Person is desirably integrated into another system, or some features can be ignored or not executed.Another point, shown or discussed is mutual
Between coupling, direct-coupling or communication connection can be INDIRECT COUPLING or communication link by some interfaces, unit or module
It connects, can be electrical or other forms.
The unit illustrated as separating component may or may not be physically separated, aobvious as unit
The component shown may or may not be physical unit, you can be located at a place, or may be distributed over multiple
On unit.Some or all of unit therein can be selected according to the actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in each embodiment of the present invention can be integrated in a processing unit, it can also
It is that each unit physically exists alone, it can also be during two or more units be integrated in one unit.Above-mentioned integrated list
The form that hardware had both may be used in member is realized, can also be realized in the form of SFU software functional unit.
If the integrated unit is realized in the form of SFU software functional unit and sells or use as independent product
When, it can be stored in a computer read/write memory medium.Based on this understanding, technical scheme of the present invention is substantially
The all or part of the part that contributes to existing technology or the technical solution can be in the form of software products in other words
It embodies, which is stored in a storage medium, including some instructions are used so that a computer
Equipment (can be personal computer, server or network equipment etc.) execute each embodiment the method for the present invention whole or
Part steps.And storage medium above-mentioned includes：USB flash disk, read-only memory (ROM, Read-Only Memory), arbitrary access are deposited
Reservoir (RAM, Random Access Memory), mobile hard disk, magnetic disc or CD etc. are various can to store program code
Medium.
The above is only a preferred embodiment of the present invention, it is noted that for the ordinary skill people of the art
For member, various improvements and modifications may be made without departing from the principle of the present invention, these improvements and modifications are also answered
It is considered as protection scope of the present invention.
Claims (10)
- The shadow circuit 1. one kind disappears, which is characterized in that including：Observation circuit for receiving shutdown signal, and generates execution signal, wherein the shutdown signal is for characterizing display screen Horizontal drive circuit disconnect；Execution circuit is connect with the output end of the observation circuit and the horizontal drive circuit, for receiving the execution signal, And execute drop-down potential operations, wherein the drop-down potential operations are used to pull down the current potential of the output end of the horizontal drive circuit；Wherein, the execution circuit includes：Amplifier, positive input are connect with the output end of the horizontal drive circuit, reverse input end access drop-down reference potential, Control terminal is connect with the first end of the observation circuit, for the horizontal drive circuit output end current potential and it is described under Reference potential is drawn, potential difference is obtained；The first transistor, grid are connect with the output end of the amplifier, and drain electrode is connect with the output end of the horizontal drive circuit, Source electrode is grounded, for being connected in the case where the potential difference is more than or equal to preset potential difference；Wherein, the first transistor is N-channel field effect transistor.
- 2. circuit according to claim 1, which is characterized in that the second end of the observation circuit is defeated with the amplifier Outlet connects, in the case where the potential difference is less than or equal to preset stopping potential value, generating stop signal, wherein The stop signal stops executing the drop-down potential operations for controlling the execution circuit.
- 3. circuit according to claim 2, which is characterized in that the execution circuit further includes：Second transistor, grid with The first end of the observation circuit connects, and drain electrode is connect with the grid of the first transistor, source electrode ground connection, described for receiving Stop signal, and generate cut-off signals, wherein the cut-off signals are for controlling the first transistor shutdown.
- 4. circuit according to claim 1, which is characterized in that the execution circuit further includes：Circuit is protected, institute is connected on It states between the output end of horizontal drive circuit and the drain electrode of the first transistor, and connects with the positive input of the amplifier It connects, is used for current limliting.
- 5. circuit according to claim 4, which is characterized in that the protection circuit includes：First resistor and second resistance, The first resistor and second resistance series connection, the connecting node and the amplification of the first resistor and the second resistance The positive input of device connects.
- 6. a kind of control method for the shadow circuit that disappears, which is characterized in that including：After the horizontal drive circuit of display screen disconnects, observation circuit receives shutdown signal, wherein the shutdown signal is used for table The horizontal drive circuit is levied to disconnect；The observation circuit, which generates, executes signal, and the execution signal is sent to execution circuit；After the execution circuit receives the execution signal, drop-down potential operations are executed, wherein the drop-down current potential behaviour Act on the current potential for the output end for pulling down the horizontal drive circuit；Wherein, after the execution circuit receives the execution signal, executing drop-down potential operations includes：Amplifier in the execution circuit obtains drop-down reference potential；The current potential of the output end of the horizontal drive circuit and the drop-down reference potential are compared by the amplifier, obtain electricity Potential difference value, and the potential difference is sent to the first transistor；The first transistor judges whether the potential difference is more than or equal to preset potential difference；In the case where the potential difference is more than or equal to the preset potential difference, the first transistor conducting, to execute The drop-down potential operations.
- 7. according to the method described in claim 6, it is characterized in that, in the amplifier by the output end of the horizontal drive circuit Current potential and the drop-down reference potential be compared, after obtaining potential difference, the method further includes：The potential difference is sent to the observation circuit by the amplifier；The observation circuit judges whether the potential difference is less than or equal to preset stopping potential value；In the case where the potential difference is less than or equal to the preset stopping potential value, the observation circuit, which generates, stops letter Number, and the stop signal is sent to execution circuit；The execution circuit stops executing the drop-down potential operations after receiving the stop signal.
- 8. the method according to the description of claim 7 is characterized in that the execution circuit receive the stop signal it Afterwards, stopping the execution drop-down potential operations includes：The amplifier is stopped；Second transistor shutdown in the execution circuit, and control the first transistor shutdown.
- 9. a kind of horizontal drive circuit, which is characterized in that including：Transistor, drain electrode are connect with power supply, and source electrode accesses the output end of horizontal drive circuit；Observation circuit for receiving shutdown signal, and generates execution signal, wherein the shutdown signal is for characterizing the row Driving circuit disconnects；Execution circuit is connect with the source electrode of the observation circuit and the transistor, for receiving the execution signal, and is executed Pull down potential operations, wherein the drop-down potential operations are used to pull down the current potential of the output end of the horizontal drive circuit；Wherein, the execution circuit includes：Amplifier, positive input are connect with the source electrode of the transistor, reverse input end access drop-down reference potential, control terminal It is connect with the first end of the observation circuit, the current potential of the output end for the horizontal drive circuit and drop-down reference Current potential obtains potential difference；The first transistor, grid are connect with the output end of the amplifier, and drain electrode is connect with the source electrode of the transistor, and source electrode connects Ground, for being connected in the case where the potential difference is more than or equal to preset potential difference；Wherein, the first transistor is N-channel field effect transistor.
- 10. a kind of display screen, which is characterized in that including：Horizontal drive circuit described in claim 9.
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| CN201610324382.2A CN105810146B (en) | 2016-05-16 | 2016-05-16 | Disappear shadow circuit and its control method, horizontal drive circuit and display screen |
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| CN112051783A (en) * | 2020-09-22 | 2020-12-08 | 禹创半导体(深圳)有限公司 | A forced pull-to-ground for data output in a power-free mode |
| CN114241994A (en) * | 2022-01-20 | 2022-03-25 | 集璞(上海)科技有限公司 | Pixel driving circuit and display panel |
| CN115294928B (en) * | 2022-10-08 | 2022-12-27 | 成都利普芯微电子有限公司 | Shadow elimination circuit, line driving circuit and display screen |
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| CN205810341U (en) * | 2016-05-16 | 2016-12-14 | 北京集创北方科技股份有限公司 | Disappear shadow circuit, horizontal drive circuit and display screen |
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| JPH0595493A (en) * | 1991-10-01 | 1993-04-16 | Matsushita Electric Ind Co Ltd | Vertical blanking line erasing circuit |
| DE69224959T2 (en) * | 1991-11-07 | 1998-08-13 | Canon Kk | Liquid crystal device and control method therefor |
| JP3686769B2 (en) * | 1999-01-29 | 2005-08-24 | 日本電気株式会社 | Organic EL element driving apparatus and driving method |
| CN202310213U (en) * | 2011-10-24 | 2012-07-04 | 段四才 | Line blanking circuit for scanning light emitting diode (LED) module |
| CN103871355B (en) * | 2012-12-17 | 2016-12-28 | 上海得倍电子技术有限公司 | LED shows giant-screen high-velocity scanning controller |
| CN203179469U (en) * | 2013-01-08 | 2013-09-04 | 深圳市易事达电子股份有限公司 | LED panel scanning line blanking circuit |
| CN103489407B (en) * | 2013-10-12 | 2015-06-03 | 深圳市大族元亨光电股份有限公司 | Non-control-lightening-free shadow elimination circuit for LED (Light Emitting Diode) display screen |
| CN103646628B (en) * | 2013-11-22 | 2016-05-25 | 国家电网公司 | A kind of blanking circuit |
| US9590613B2 (en) * | 2014-06-23 | 2017-03-07 | Microchip Technology Inc. | Circuit and method for active crosstalk reduction in multiple-channel power supply controllers |
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