CN102542991B - Column scanning driving method and platform for display screen - Google Patents

Abstract

The invention discloses a column scanning driving method and a platform for a display screen, The driving method particularly comprises the following steps: the column scanning line signals of the display screen are subjected to block processing; and the column signals subjected to the block processing are outputted to column scanning lines. According to the column scanning driving method and a platform provided by the invention, through selecting the sub-block number, the number driving I/O and the data clock period, the optimal balance among the I/O number, the I/O output data speed and the block conversion speed is achieved, thereby meeting the display requirements of the display screen; and after the screen is subjected to the block processing, the time-sharing multiplexing for the pin is realized, and only one block is driven at a time, thereby reducing the number of the required pins. The column scanning driving method and the platform for the display screen provided by the invention can greatly reduce the pins of scanning driving signals output by a programmable chip, can maintain the flexibility of the scanning driving, and can effectively support the development of the high-performance display screen.

Description

A kind of display screen arrange scanning drive method and device

Technical field

The invention belongs to display driver technical field, be specifically related to the design of a kind of display screen arrange scanning drive method and device.

Background technology

OLED(Organic Light-Emitting Diode) display screen is regarded as the novel planar display technique of tool potentiality of future generation, and it has possessed the incomparable advantage of many LCD.

One of core technology that Driving technique shows as OLED, be the key of successfully developing high-performance OLED, and the design of special drive IC often lags behind the exploitation of display screen far away, and expense is higher, becomes the factor of restriction OLED producer development.Therefore developing the designing technique of OLED drive unit oneself grasp device, for research OLED Driving technique provides software and hardware to support, is one of prerequisite core competence of open OLED.

First OLED drive principle is described below: showing with LCD plane, image is delivered to OLED screen by one one and is shown, for avoiding display frame flicker, image must keep certain frequency, with field between synchronize (as shown in Figure 1) by synchronizing signal.To every field pattern image source, view data is sent to display screen by a line a line, goes and in the ranks synchronizes by synchronizing signal.To every row image source, with regard to OLED, be expert at synchronous effectively after, effectively (OLED basic pixel cell as shown in Figure 2) of sweep signal, transistor T 1 conducting in Fig. 2, this makes the state of T2 be determined by data line voltage.Capacitor C s makes after the end of scan, and when T2 state remains on scanning, electric capacity completes the state after discharging and recharging.The structure of OLED pixel cell, has determined in every line scanning stage, view data need all be sent to data line.After data line has shown, the scanning of then carrying out next line shows, until complete the demonstration of a field data.

As from the foregoing, driving OLED normally to show, control module must complete the scanning to all OLED pixel columns in a field time, and in scan period, sends corresponding data, to control the GTG of display unit.Therefore the task that the driving of OLED will complete, the one, the sequential of gated sweep signal and data-signal, the one, generate driving OLED and show required voltage.The former is completed by digital circuit conventionally, and the latter is completed by mimic channel conventionally.

The driving voltage of OLED is generally in 10V left and right, data-signal and sweep signal are digital signal, and the voltage of digital signal is generally in about 3V, therefore data-signal and sweep signal must be passed through digital-to-analog conversion and level conversion, can show by driving OLED display unit.OLED is driven to task, after OLED screen maturation, can be completed by special chip, chip is digital-to-analogue hybrid chip.But in the exploitation OLED display screen stage, chip development lags behind, and therefore numerical portion need be completed as FPGA by programmable chip; Simulation part adopts DC-DC and D/A and some other mimic channel to complete (programmable chip is connected as shown in Figure 3 with OLED screen) conventionally.Due to control OLED show sweep trace and data line along with screen resolution its amount of raising very huge, therefore after digital-to-analog circuit separates, it is very large to the requirement of programmable chip interface, if resolution is 320X240AMOLED display screen, there are 320 sweep traces, 720 data lines.If display unit has 256 gray scale variation, be 8 by programmable chip to the data-signal of the D/A output of every data lines, 8 programmable chip pins drive a data lines, add scanning pin, drive this AMOLED screen, required pin able to programme will reach 6080, and number of pins is more, realize complicated.Therefore, realize the driving of OLED display screen, must change driving method and device, reduce and drive required interface pin.

Summary of the invention

The object of the invention is to drive in order to solve existing OLED display screen the problems referred to above that exist, proposed a kind of display screen arrange scanning drive method.

Technical scheme of the present invention is: a kind of display screen arrange scanning drive method, be specially: the column scan line signal to display screen carries out piecemeal processing, column signal after treatment piecemeal is outputed to column scan line, and it is that be t the sweep time of establishing a line that described piecemeal is processed detailed process, data line is divided into n piece, each gating time is identical, is t/n, establishes and in each, has m data lines, every data lines is driven by x output I/O mouth, and total driving I/O mouth number is y; The pixel clock frequency that shows image is f _p, the data output frequency of I/O mouth is f, the inversion frequency of piece is f _c, described x, y, f _p, f _c, m, n and f meet following relation:

$\left\{\begin{array}{cc}m*n=c& \left(1\right)\\ y=m*x& \left(2\right)\\ f=n/t& \left(3\right)\\ \frac{{3f}_p}{m}\≤f\≤f_c& \left(4\right)\end{array}\right.$

Wherein, in formula (1), c represents the data line that display screen is total, c, f _p, f _cshow that by display screen the attribute of image and the attribute of piece pre-determine with t, m is determined in through type (1), (3), (4), and n and f can determine the size of piece and the data output frequency of I/O mouth.

Further, described display screen is specially OLED screen.

Further, described piece is specifically changed realization by D/A.

Further, described piece is specifically realized by level conversion.

In order to address the above problem, the invention allows for a kind of display screen arrange scanning driving device, comprising: control module and piece processing unit, described control module is sent column data signal to piece processing unit one by one under clock control; The number of described processing unit is n, has m data lines in each processing unit, and every data lines is driven by x output I/O mouth, and total driving I/O mouth number is y; The pixel clock frequency that shows image is f _p, the frequency of clock is f, the inversion frequency of piece processing unit is f _c, the sweep time that t is a line, described x, y, f _p, f _c, m, n and f meet following relation:

$\left\{\begin{array}{cc}m*n=c& \left(1\right)\\ y=m*x& \left(2\right)\\ f=n/t& \left(3\right)\\ \frac{{3f}_p}{m}\≤f\≤f_c& \left(4\right)\end{array}\right.$

Wherein, in formula (1), c represents the data line that display screen is total, c, f _p, f _cshow that by display screen the attribute of image and the attribute of piece processing unit pre-determine with t, m is determined in through type (1), (3), (4), and n and f can determine the size of processing unit and the frequency f of clock.

Further, described processing unit is specially: D/A converting unit.

Further, described processing unit is specially: level conversion unit.

As a kind of preferred version, described screen column scan drive unit also comprises digit translation unit and analogy decode unit, and described control module is for encoding to Scan out; Described digit translation unit is to carrying out digit translation one time through the signal of coding, the digital signal of described analogy decode unit after to digit translation carried out an analogy decode, and the sweep signal of the analogy decode output of analogy decode unit is directly sent to the horizontal scanning line of display screen.

Beneficial effect of the present invention: display screen arrange scanning drive method of the present invention and device are by selecting piecemeal number, driving number and the data clock cycle of I/O to make I/O number, I/O output data rate, the switching rate of piece reaches optimum balance, can meet display screen and show required requirement; By shielding after piecemeal processing, realize pin time-sharing multiplexing, only drive a piece a moment, thereby reduced the number of required pin.Display screen arrange scanning drive method of the present invention and device can reduce the pin of programmable chip output scanning driving signal greatly, can keep again the dirigibility of turntable driving simultaneously, thereby the exploitation of support high-performance display screen that can be strong.

Figure of description

Fig. 1 is plane displaying principle schematic diagram.

Fig. 2 is basic active OLED pixel cell schematic diagram.

Fig. 3 is the connection diagram of existing programmable chip and OLED screen.

Fig. 4 is the structural representation of display screen arrange scanning driving device of the present invention.

Fig. 5 is column scan drive assembly design 1 in embodiment.

Fig. 6 is column scan drive assembly design 2 in embodiment.

Fig. 7 is that embodiment midrange is according to piecemeal schematic diagram.

Fig. 8 is that in embodiment, AMOLED320x240 drive assembly design is realized.

Fig. 9 be in embodiment 320x240x3AOLED line scanning drive in digit translation schematic diagram.

Embodiment

Below in conjunction with accompanying drawing and concrete embodiment, the invention will be further elaborated.

Display screen arrange scanning drive method of the present invention, be specially: the column scan line signal to display screen carries out piecemeal processing, column signal after treatment piecemeal is outputed to column scan line, and it is that be t the sweep time of establishing a line that described piecemeal is processed detailed process, data line is divided into n piece, each gating time is identical, is t/n, establishes and in each, has m data lines, every data lines is driven by x output I/O mouth, and total driving I/O mouth number is y; The pixel clock frequency that shows image is f _p, the data output frequency of I/O mouth is f, the inversion frequency of piece is f _c, described x, y, f _p, f _c, m, n and f meet following relation:

$\left\{\begin{array}{cc}m*n=c& \left(1\right)\\ y=m*x& \left(2\right)\\ f=n/t& \left(3\right)\\ \frac{{3f}_p}{m}\≤f\≤f_c& \left(4\right)\end{array}\right.$

Wherein, in formula (1), c represents the data line that display screen is total, c, f _p, f _cshow that by display screen the attribute of image and the attribute of piece pre-determine with t, m is determined in through type (1), (3), (4), and n and f can determine the size of piece and the data output frequency of I/O mouth.

Display driver of the present invention belongs to line production, and the view data total amount that therefore in the unit interval, coding-control chip receives equates with the data total amount outputing on screen, i.e. requirement

Here, described piece is specifically changed realization by D/A, or level conversion realizes.

Described display screen is specially OLED screen.Those skilled in the art will appreciate that the display screen arrange scanning drive method here also can be for the driving of other display screen.

Based on above-mentioned column scan driving method, the invention allows for a kind of display screen arrange scanning driving device, as shown in Figure 4, comprising: control module and piece processing unit, described control module is sent column data signal to piece processing unit one by one under clock control; The number of described processing unit is n, has m data lines in each processing unit, and every data lines is driven by x output I/O mouth, and total driving I/O mouth number is y; The pixel clock frequency that shows image is f _p, the frequency of clock is f, the inversion frequency of piece processing unit is f _c, described x, y, f _p, f _c, m, n and f meet following relation:

Wherein, in formula (1), c represents the data line that display screen is total, c, f _p, f _cshow that by display screen the attribute of image and the attribute of piece processing unit pre-determine with t, m is determined in through type (1), (3), (4), and n and f can determine the size of processing unit and the frequency f of clock.Data are by clock control, and the frequency of clock is f, and the frequency f of the clock is here: the data output frequency of I/O mouth.

Here, piece processing unit is specially: D/A converting unit (as shown in the design apparatus 1 of Fig. 5), or level conversion unit (as shown in the design apparatus 2 of Fig. 6).

As a kind of preferred version, as shown in Figure 4, described screen column scan drive unit also comprises digit translation unit and analogy decode unit, and described control module is for encoding to Scan out; Described digit translation unit is to carrying out digit translation one time through the signal of coding, the digital signal of described analogy decode unit after to digit translation carried out an analogy decode, and the sweep signal of the analogy decode output of analogy decode unit is directly sent to the horizontal scanning line of display screen.

In preferred version, the line scanning of drive unit drives by coding, decoding, decoding completes the driving to display screen again, can flexibly and effectively realize the turntable driving that arbitrary dimension is driven arbitrarily to the display screen of requirement.Control module is specifically realized by programmable chip.Programmable chip configuration circuit and SDRAM are the peripheral circuit of programmable chip, first in programmable chip, Scan out are encoded, and dwindle the pin of programmable chip to scanning output; Then to carrying out digit translation one time through the signal of coding, again digital signal is carried out to an analogy decode afterwards, the sweep signal of analogy decode output is directly sent to OLED screen sweep trace, thereby completes the turntable driving to OLED screen.

Digit translation unit can be completed by programmable chip, analogy decode unit can select Multipexer selector switch to complete as ADG506A, if analogy decode unit output voltage can not meet the demand of OLED voltage, can behind analogy decode unit, increase level-conversion circuit.

As shown in Figure 5, programmable chip 1 is realized OLED screen Drive of row and column sequential, and line scanning drives and adopts---decoding---realization of decoding again of encoding, and the row of this device drives and all adopts this thought to realize.Drive according to the difference of display mode for row, can have Fig. 5, two kinds of different designs of Fig. 6.

As shown in Figure 5, column scan data line is carried out to piecemeal, within whole sweep time, control module is sent demonstration data to each piece one by one, but only send demonstration data to a piece at synchronization control chip, therefore the number of pins being connected with control module is only for driving the required number of pins of data line of a piece, and the method that adopts this piecemeal to drive just can reduce control module driver output pin.But according to the thought of going here and there and changing, this operation certainly will improve control module I/O mouth output data speed, if but data output speed is too fast, in piece (block), the speed of digital-to-analog conversion or level conversion may not catch up with, therefore the size of piece, must meet certain measuring, can be by following relational expression, determine that this measures.

As shown in Figure 7, be t the sweep time of establishing a line, and data line is divided into several pieces, and each gating time is identical, be t/n, wherein, n is piecemeal number, if there is m data lines in each, every data lines is driven by x output I/O mouth, and total driving I/O mouth number is y; Show that image pixel clock frequency is f _p, the data output frequency of control chip I/O mouth is f, in piece, digital-to-analogue or level conversion frequency are f _c, device will normally be worked, and must meet following relation:

$\left\{\begin{array}{cc}m*n=c& \left(1\right)\\ y=m*x& \left(2\right)\\ f=n/t& \left(3\right)\\ \frac{{3f}_p}{m}\≤f\≤f_c& \left(4\right)\end{array}\right.$

Wherein, in formula (1), c represents the data line that display screen is total, is constant.F _pshielding after resolution and frame frequency are determined and can determine, f _cafter digital-to-analogue or level conversion device are determined, also can determine, after determining, t also determines frame frequency per horizontal-scanning interval.Therefore by m only in formula, n and f are unknown, and by formula (1), (3), (4), 3 relational expressions are just in time determined m, and n and f, can determine the block size that is applicable to device work, and I/O mouth data output frequency.

For instance, show as completed 320*3*240 image, its frame frequency is 60HZ, and can roughly calculate pixel clock is 5M left and right, is roughly 15.67us the sweep time of a line.By above-mentioned relation formula, can obtain

be mf _c>=46.1M>=15M, gets final product to obtain mf _c>=46.1M, as adopted AD8600 to complete digital-to-analog conversion, its switching rate can reach 12.5M, and m is more than or equal to 4 requirements that can meet device.

To design apparatus 1(as shown in Figure 5), its display mode is to control the GTG of display unit with voltage swing, therefore every OLED data line, need be driven by the programmable chip I/O of some, as realized 256 GTGs, need 8 I/O mouths to drive, i.e. x=8 in above-mentioned formula, the multiple that now y is 8.The sequential that in device, programmable chip will complete: scanning OLED display line, in the every row of scanning, the each BLOCK of gating sends data simultaneously successively, and through the row of D/A conversion rear drive display screen, its GTG is determined by the voltage after D/A.

Design apparatus 2(is as shown in Figure 6), its display mode is to control the GTG of display unit with the length of displaying time.Such display mode, its x=1, an I/O drives an OLED data line.For realizing the gray scale variation of display unit, need, by demonstration data, be divided into several subfields, the duration of each subfield is different, as realized 256 GTGs, needs the subfield of 8 various durations.In each subfield, programmable chip all will carry out single pass driving to OLED, in scan period, programmable chip drives and only sends two states to column scan, and " 1 " or " 0 ", equally in the every row of scanning, the each BLOCK of gating successively, send data simultaneously, through level conversion rear drive OLED data line, make OLED display unit show or not show.Two kinds of its display effects of device are identical, and programmable I/O mouth that just device 2 needs is less, but needs programmable chip to have more complicated rank scanning control sequential.

Take resolution as 320X240X3AMOLED display screen is as example, realize showing the image of 60HZ frame frequency speed, the data clock (pixel clock 3 times) needing, probably in 15M left and right.The programmable chip of device is all selected the FPGA XC3S1000-4fg456 of XILINX company, and FPGA completes Drive of row and column sequential control, and line scanning is encoded, and controls analog-digital chip.

As shown in Figure 8, selecting arrangement 1 is realized and is selected AD8600 to carry out digital-to-analog conversion, this is the analog-digital chip that 8 bit digital are inputted 16 tunnels analogies outputs, therefore will realize the driving of this screen is needed altogether to 45 such chips, and the high conversion rate of AD8600 can reach 12.5M.According to analysis above, select m=4 can meet matching requirements, but owing to there being 45 AD8600 chips, for the ease of grouping, select m=5 here, FPGA once drives 5 data lines, the number that is I/O is 40, AD8600 can be divided into 9 groups, every group of 5 AD8600 chips.After one group of digital-to-analogue chip of FPGA gating, when each, clockwise 5 data lines are sent data, complete the gating of one group of digital-to-analogue chip after 16 clocks, and then next group of gating, until show complete.Now, I/O mouth data output frequency is 9.2M, is 40 for being listed as the I/O number of driving, compared with the I/O number driving, has obviously reduced a lot with 720 of original needs row.

Display screen line drives and is described as follows: fpga chip 1 completes Drive of row and column sequential, and to line scan signals coding output signal a[7:0], b[7:0], c[4:0], in fpga chip 2, according to the demand of analogy decode circuit, complete the decoding to signal a, b, c, its decoding block diagram as shown in Figure 9.The signal that chip 2 is exported is sent to 20 ADG506A and carries out the final formation of analogy decode 320 tunnel turntable driving, thereby completes the driving to this screen.

Device 2 completes the driving of 320X240X3AMOLED similar with device 1, is no longer elaborated.

Can drive 320X240X3AMOLED through this column scan drive unit of checking.When display resolution improves, the upgrading of this drive unit is also easy to, and brings up to 1024X768 as resolution, has 2304 road column data lines, needs with 144 AD8600.According to formula

can obtain mf _c>=147M, AD8600 switching rate can reach 12.5M, and m is more than or equal to 12 requirements that can meet device, and in the time of m=12, the number of required I/O is 96, and now I/O mouth data output frequency is 12.3M.Select the FPGA of XILINX company programmable chip XC3S1000, maximum has 391 user I/O, and this is enough to satisfy the demands.Slightly make an amendment by the software to programmable chip, circuit again typesetting can be realized upgrading, much easier more than exploitation chip.Column scan drive unit of the present invention is owing to using separation circuit realization, and therefore circuit is larger, while can be used as the checking of exploitation OLED screen, uses, will be no longer applicable after OLED shields maturation.

Those of ordinary skill in the art will appreciate that, embodiment described here is in order to help reader understanding's principle of the present invention, should be understood to that protection scope of the present invention is not limited to such special statement and embodiment.Those of ordinary skill in the art can make various other various concrete distortion and combinations that do not depart from essence of the present invention according to these technology enlightenments disclosed by the invention, and these distortion and combination are still in protection scope of the present invention.

Claims (6)

1. a display screen arrange scanning drive method, be specially: the column scan line signal to display screen carries out piecemeal processing, column signal after treatment piecemeal is outputed to column scan line, and it is that be t the sweep time of establishing a line that described piecemeal is processed detailed process, data line is divided into n piece, each gating time is identical, is t/n, establishes and in each, has m data lines, every data lines is driven by x output I/O mouth, and total driving I/O mouth number is y; The pixel clock frequency that shows image is f _p, the data output frequency of I/O mouth is f, and described piece is specifically changed by D/A or level conversion realizes conversion, and the D/A in piece changes or level conversion frequency is f _c, described x, y, f _p, f _c, m, n and f meet following relation:

$\left\{\begin{array}{cc}m*n=c& \left(1\right)\\ y=m*x& \left(2\right)\\ f=n/t& \left(3\right)\\ \frac{3f_p}{m}\≤f\≤f_c& \left(4\right)\end{array}\right.$

Wherein, in formula (1), c represents the data line that display screen is total, c, f _p, f _cshow that by display screen the attribute of image and the attribute of piece pre-determine with t, m is determined in through type (1), (3), (4), and n and f can determine the size of piece and the data output frequency of I/O mouth.

2. column scan driving method according to claim 1, is characterized in that, described display screen is specially OLED screen.

3. a display screen arrange scanning driving device, comprising: control module and piece processing unit, and described control module is sent column data signal to piece processing unit one by one under clock control; The number of described processing unit is n, has m data lines in each processing unit, and every data lines is driven by x output I/O mouth, and total driving I/O mouth number is y; The pixel clock frequency that shows image is f _p, the frequency of clock is f, the sweep time that t is a line, the frequency f of described clock is the data output frequency of I/O mouth; Described processing unit specifically changed by D/A or level conversion realization conversion, and the D/A in piece processing unit changes or level conversion frequency is f _c, described x, y, f _p, f _c, m, n and f meet following relation:

$\left\{\begin{array}{cc}m*n=c& \left(1\right)\\ y=m*x& \left(2\right)\\ f=n/t& \left(3\right)\\ \frac{3f_p}{m}\≤f\≤f_c& \left(4\right)\end{array}\right.$

Wherein, in formula (1), c represents the data line that display screen is total, c, f _p, f _cshow that by display screen the attribute of image and the attribute of piece processing unit pre-determine with t, m is determined in through type (1), (3), (4), and n and f can determine the size of processing unit and the frequency f of clock.

4. column scan drive unit according to claim 3, is characterized in that, described display screen is specially OLED screen.

5. column scan drive unit according to claim 4, is characterized in that, described screen column scan drive unit also comprises digit translation unit and analogy decode unit, and described control module is for encoding to Scan out; Described digit translation unit is to carrying out digit translation one time through the signal of coding, the digital signal of described analogy decode unit after to digit translation carried out an analogy decode, and the sweep signal of the analogy decode output of analogy decode unit is directly sent to the horizontal scanning line of display screen.

6. column scan drive unit according to claim 5, is characterized in that, described digit translation unit is specifically realized by programmable chip, and described analogy decode unit is specifically realized by ADG506A.

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