Background technology
Currently, smectic liquid crystal screen has obtained more and more widely in fields such as building decoration and fitment, privacy controls
Using.Smectic liquid crystal screen is (reference can be made to Chinese invention patent " the smectic phase liquid crystal display of Patent No. ZL200710304409.2
The description as described in smectic liquid crystal screen in screen drive circuit for display " etc.) include the first base layer and the second base layer, first
It is preferred that mixed layer, smectic liquid crystal made of smectic liquid crystal and additives mixed are equipped between base layer and the second base layer
For A class smectic liquid crystal organic compounds, additive is the compound with conductive characteristic, in the first base layer towards mixed layer
Side is equipped with the first conductive electrode layer being made of H strip shaped electric poles arranged in parallel, in the second base layer towards mixed layer
Side is equipped with the second conductive electrode layer being made of V strip shaped electric poles arranged in parallel, the H strip electricity of the first conductive electrode layer
Pole is mutually orthogonal with V strip shaped electric poles of the second conductive electrode layer, and (H, V are just more than 1 to the pixel array of one H × V of formation
Integer).
There are many kinds for the driving method of smectic liquid crystal screen, by taking the common driving method of smectic liquid crystal screen as an example, commonly use
Driving method includes following two stages:It initializes first, the piclear of screen display is fallen, is then owned to liquid crystal display
Row carries out progressive scan driving.
In initialization, usually all rows, all row are carried out with the application of low-frequency high-voltage positive negative pulse stuffing pair, makes smectic phase
Mist is integrally presented in liquid crystal display, to wait for that subsequent image is shown, low-frequency high-voltage positive negative pulse stuffing therein to refer to a pair of of frequency it is identical,
Voltage magnitude is identical, opposite in phase pulse pair, as shown in Figure 1.When the often row to liquid crystal display carries out turntable driving, generally want
Execute following steps:To the row load high-frequency and high-voltage positive negative pulse stuffing of scanning, remaining row loads 0V voltages, need is shown according to liquid crystal display
It wants, the corresponding row of driven pixel is needed to load, voltage identical as the high-frequency and high-voltage positive negative pulse stuffing frequency of row load of scanning
Amplitude is identical, opposite in phase high-frequency and high-voltage positive negative pulse stuffing, without the corresponding row load of driven pixel and scanning
The high-frequency and high-voltage positive negative pulse stuffing frequency of row load is identical, voltage magnitude is identical, the identical high-frequency and high-voltage positive negative pulse stuffing of phase.Such as figure
2, the high-frequency and high-voltage positive negative pulse stuffing for needing the corresponding row, column of driven pixel to be loaded is shown in figure.
For other driving methods, each has the characteristics that oneself uniqueness, but juche idea and above-mentioned common driving
Method is roughly the same, is all to carry out turntable driving to row by high-frequency and high-voltage positive negative pulse stuffing on the basis of initialization, and first
Beginningization substantially apply low-frequency high-voltage positive negative pulse stuffing to come make liquid crystal display in mist.As can be seen that other driving methods are all
Improvement on above-mentioned common driving method, for example, changeable common driving method initial phase, i.e., to all rows, all
Row carry out repeatedly application of the low-frequency high-voltage positive negative pulse stuffing to, high-frequency and high-voltage positive negative pulse stuffing pair, so that smectic liquid crystal screen can be quick
It presents misty.
It can be found that although the existing various driving methods of smectic liquid crystal screen can realize image from actual implementation
The function of display, but in initial phase and in the turntable driving stage, electricity can slowly disappear with the increase of brush screen number
Consumption, and at present for applying for the higher smectic liquid crystal screen of voltage value, there is no the functions of designing electric power detection, thus work as
Smectic liquid crystal screen electricity is reduced to when being not enough to normal driving, drive pulse waveform distortion can usually occur, and then lead to liquid
The display of crystalline substance screen is abnormal.
It can be seen that in order to realize the normal display of image, a kind of detection smectic liquid crystal screen is designed in driving process
The how many technical solution of electricity, is current urgent problem in (initial phase and turntable driving stage).
Specific implementation mode
The detection method of quantity of electricity of smectic liquid crystal screen of the present invention is suitable for smectic liquid crystal screen, and smectic liquid crystal screen can be found in
In Chinese invention patent " driving circuit for smectic state LCD display " of Patent No. ZL200710304409.2 etc.
Associated description, usually, smectic liquid crystal screen include the first base layer and the second base layer, in the first base layer and the second matrix
The mixed layer made of smectic liquid crystal and additives mixed is equipped between layer, smectic liquid crystal is preferably A class smectic liquid crystals
Organic compound, microcosmic to be known as smectic liquid crystal molecule, additive is the compound with conductive characteristic, in the first base layer court
The first conductive electrode layer being made of H strip shaped electric poles arranged in parallel is equipped with to the side of mixed layer, in the second base layer court
The second conductive electrode layer being made of V strip shaped electric poles arranged in parallel, the first conductive electrode layer are equipped with to the side of mixed layer
H strip shaped electric poles it is mutually orthogonal with V strip shaped electric poles of the second conductive electrode layer, formed a H × V pixel array (H, V
For the positive integer more than 1).
There are many kinds for the driving method of smectic liquid crystal screen, by taking the common driving method of smectic liquid crystal screen as an example, commonly use
Driving method includes following two stages:The piclear of smectic liquid crystal screen display is fallen, and swept by initial phase
It retouches the driving stage, i.e., to all traveling line scans of smectic liquid crystal screen driving (line by line or take other manner).
Initial phase is usually the application that all rows, all row are carried out with low-frequency high-voltage positive negative pulse stuffing pair, makes smectic phase
Mist is integrally presented in liquid crystal display, to wait for that subsequent image is shown, low-frequency high-voltage positive negative pulse stuffing therein to refer to a pair of of frequency it is identical,
Voltage magnitude is identical, opposite in phase pulse pair, as shown in Figure 1.
In the turntable driving stage following steps are generally executed when carrying out turntable driving to the often row of smectic liquid crystal screen:
To the row load high-frequency and high-voltage positive negative pulse stuffing of turntable driving, remaining row loads 0V voltages, according to the display need of smectic liquid crystal screen
It wants, needs the high-frequency and high-voltage positive negative pulse stuffing frequency phase of driven pixel corresponding row load and the row load of turntable driving at this time
High-frequency and high-voltage positive negative pulse stuffing identical with, voltage magnitude, opposite in phase, without the corresponding row load of driven pixel with
The high-frequency and high-voltage positive negative pulse stuffing frequency of the row load of turntable driving is identical at this time, voltage magnitude is identical, the identical high frequency of phase is high
Positive pressure negative pulse.Such as Fig. 2, it is positive and negative that the high-frequency and high-voltage for needing the corresponding row, column of driven pixel to be loaded is shown in the figure
Pulse.
Other driving methods in addition to common driving method are all the corresponding improvement carried out on common driving method, such as
Change the initial phase for commonly using driving method, low-frequency high-voltage positive negative pulse stuffing is carried out to, high-frequency and high-voltage just to all rows, all row
The application repeatedly of negative pulse pair, so that mist can be quickly presented in smectic liquid crystal screen.As can be seen that various driving methods have respectively
From the characteristics of, but their juche idea is roughly the same, is carried out by hf and hv pulse on the basis of initialization
Row turntable driving, and the basic thought initialized is to apply low-frequency high-voltage pulse to misty to make smectic liquid crystal screen present.
Therefore, be based on above-mentioned analysis, this invention takes initial phase to low-frequency high-voltage pulse carry out electric power detection,
And the mode of electric power detection is carried out to hf and hv pulse in the turntable driving stage, it can really detect smectic liquid crystal to reach
Shield the purpose of the actual conditions of the drive pulse waveform variation shown for piclear, image during brush screen.
As the detection method of quantity of electricity of Fig. 3, smectic liquid crystal screen of the present invention include the following steps:
1) when initializing smectic liquid crystal screen, for the low-frequency high-voltage arteries and veins with m pulse being applied in row or column
Punching removes a pulse (most starting a pulse applied in low-frequency high-voltage pulse) of foremost and rearmost b pulse
(the b pulse finally applied in low-frequency high-voltage pulse), to the remaining each pulse being located in intermediate (m-a-b) a pulse
Voltage value carry out average sample p time and sample mean acquired to p sampled value, p is sampled point number, to obtain
(m-a-b) information about power as initial phase is minimized in a sample mean, herein it should be noted that taking most
Small value is the voltage change minimum point of reflected waveform distortion situation in drive pulse waveform in order to obtain, to effectively prevent waveform abnormal
The generation of change, if the charge value (information about power) obtained at this time will can take corresponding measure to prevent close to alarm threshold
It is abnormal to cause display for drive pulse waveform distortion caused by the low battery of smectic liquid crystal screen, wherein in the present invention, to p times
Sampled value seeks sample mean and the method for first removing that several maximum sampled values and several minimum sampled values are averaged again can be used,
However, it is not limited to this.
2) in turntable driving smectic liquid crystal screen, for applying the hf and hv pulse with n pulse on being expert at,
It removes the c pulse (most starting the c pulse applied i.e. in hf and hv pulse) of foremost and rearmost d pulse is (i.e.
The d pulse finally applied in hf and hv pulse), to the remaining each pulse being located in intermediate (n-c-d) a pulse
Voltage value carries out 1 sampling, obtains (n-c-d) a sampled value and is used as capable adopt to (n-c-d) a sampled value averaged
Sample value is driven to be minimized in the obtained all row sampled values of each row of turntable driving smectic liquid crystal screen as scanning
The information about power in dynamic stage, even smectic liquid crystal screen are H rows, V row, then can obtain H row sampled value, then be adopted in H row
The information about power for being used as the turntable driving stage is minimized in sample value, herein it should be noted that be minimized be in order to
The voltage change minimum point of reflected waveform distortion situation in drive pulse waveform is obtained, to effectively prevent the generation of wave distortion,
If the charge value (information about power) obtained at this time will can take corresponding measure to prevent smectic liquid crystal close to alarm threshold
It is abnormal to cause display for drive pulse waveform distortion caused by the low battery of screen, wherein in the present invention, to (n-c-d) a sampling
The method for first removing that several maximum sampled values and several minimum sampled values are averaged again, but not office can be used in value averaged
It is limited to this.
In actual implementation, the electric power detection of initial phase and turntable driving stage can also be combined, i.e. this hair
Bright detection method of quantity of electricity may also include step:It is taken with the information about power in turntable driving stage in the information about power of initial phase
Minimum value entirely drives the information about power of process as smectic liquid crystal screen.At the end of brush screen of smectic liquid crystal screen, if
The charge value (information about power) detected at this time will can then take corresponding measure to prevent smectic phase liquid close to alarm threshold
The low battery of crystalline substance screen causes the drive pulse waveform distortion initiation display during next brush screen abnormal.
In step 1), it refers to for p times the foremost to removing the pulse to carry out average sample to the voltage value of single pulse
Voltage value in remaining time section (Tp periods i.e. as shown in the figure) after t1 times and backmost t2 times averagely adopt for p times
Sample.0 < t1 < Tfrost/2,0 < t2 < Tfrost/2,0 < (t1+t2) < Tfrost/2.It should be noted that in reality
In, if the pulse applied is low-frequency high-voltage positive negative pulse stuffing, pulse herein is related to direct impulse, negative-going pulse, i.e., it is positive and negative to
Pulse is intended to carry out p average sample, and positive and negative can all take above-mentioned measure to p average sample of pulse.
In actual implementation, when carrying out 1 sampling to each pulse in hf and hv pulse in step 2), sampled point is excellent
Bit selecting is not limited thereto certainly in pulse center point.
In the present invention, low-frequency high-voltage pulse is low-frequency high-voltage positive negative pulse stuffing or low-frequency high-voltage unidirectional pulse, wherein low frequency
High pressure unidirectional pulse is low-frequency high-voltage direct impulse or low-frequency high-voltage negative-going pulse, and hf and hv pulse is the positive and negative arteries and veins of high-frequency and high-voltage
Punching or high-frequency and high-voltage unidirectional pulse, wherein high-frequency and high-voltage unidirectional pulse is high-frequency and high-voltage direct impulse or high-frequency and high-voltage negative sense arteries and veins
Punching.
As shown in figure 4, the voltage magnitude of low-frequency high-voltage positive negative pulse stuffing is less than threshold voltage magnitude, twice of low-frequency high-voltage is just
The voltage magnitude of negative pulse is more than threshold voltage magnitude and the threshold voltage magnitude less than 3 times, the frequency of low-frequency high-voltage positive negative pulse stuffing
Rate (cycle T frost) between 10Hz and 200Hz, pulse number between 10 and 1600, a, b, m be even number, 2≤a≤
2 (m-1), 2≤b≤2 (m-1), 4≤(a+b)≤2 (m-2), 1≤p≤100.
As shown in fig. 6, the voltage magnitude of low-frequency high-voltage unidirectional pulse is more than threshold voltage magnitude, twice of low-frequency high-voltage list
Be less than 3 times of threshold voltage magnitude to the voltage magnitude of pulse, the frequency (cycle T frost) of low-frequency high-voltage unidirectional pulse between
Between 10Hz and 200Hz, pulse number between 5 and 800, a, b, m be even number or odd number, 1≤a≤(m-1), 1≤b
≤ (m-1), 2≤(a+b)≤(m-2), 1≤p≤100.
Herein it should be noted that a direct impulse and a negative-going pulse in low-frequency high-voltage positive negative pulse stuffing close
Carry out a referred to as pulse pair, therefore, a, b, m are meant that difference for low-frequency high-voltage positive negative pulse stuffing, low-frequency high-voltage unidirectional pulse
's.
As shown in figure 5, the voltage magnitude of high-frequency and high-voltage positive negative pulse stuffing is less than threshold voltage magnitude, twice of high-frequency and high-voltage is just
The voltage magnitude of negative pulse is more than threshold voltage magnitude and the threshold voltage magnitude less than 3 times, the frequency of high-frequency and high-voltage positive negative pulse stuffing
Rate (cycle T scan) between 1KHz and 10KHz, pulse number between 10 and 1600, c, d, n be even number, 2≤c≤2
(n-1), 2≤d≤2 (n-1), 4≤(c+d)≤2 (n-2).
As shown in fig. 7, the voltage magnitude of high-frequency and high-voltage unidirectional pulse is more than threshold voltage magnitude, twice of high-frequency and high-voltage list
Be less than 3 times of threshold voltage magnitude to the voltage magnitude of pulse, the frequency (cycle T scan) of high-frequency and high-voltage unidirectional pulse between
Between 1KHz and 10KHz, pulse number between 5 and 800, c, d, n be even number or odd number, 1≤c≤(n-1), 1≤d
≤ (n-1), 2≤(c+d)≤(n-2).
Herein it should be noted that a direct impulse and a negative-going pulse in high-frequency and high-voltage positive negative pulse stuffing close
Carry out a referred to as pulse pair, therefore, c, d, n are meant that difference for high-frequency and high-voltage positive negative pulse stuffing, high-frequency and high-voltage unidirectional pulse
's.
In the present invention, the meaning of electric power detection is equal to voltage detecting, and sampled value is the numerical value more than 0, i.e. sampled value
To sample the obtained absolute value of voltage value, such as when being sampled to negative-going pulse, the numerical value sampled need to be taken absolutely
Value obtains sampled value.
In the present invention, the driving process of smectic liquid crystal screen includes initial phase and turntable driving stage.
In the present invention, p, a, b, c, d, m, n are positive integer.
In the present invention, drive pulse waveform refers to being applied to smectic liquid crystal in initial phase, turntable driving stage
Impulse waveform on screen, such as low-frequency high-voltage pulse, hf and hv pulse.Positive negative pulse stuffing refers to direct impulse, negative-going pulse alternating
The impulse waveform of appearance, a direct impulse and with its a back to back negative-going pulse collectively pulse pair,
In practice, positive and negative to the of short duration 0 volt of voltage follow that can have several microseconds behind pulse.Unidirectional pulse refers to a kind of list only occur
The impulse waveform of direction pulse, one direction pulse such as direct impulse or negative-going pulse, a cycle of unidirectional pulse is by a list
Direction pulse and 0 volt of voltage are constituted, and one direction pulse is identical as the duration of 0 volt of voltage, and can have after one direction pulse several
Of short duration 0 volt of voltage follow of microsecond.
In the present invention, the high pressure in low frequency or hf and hv pulse refers to voltage magnitude between 10V and 250V
Voltage.
In the present invention, threshold voltage be make the smectic liquid crystal molecule in the mixed layer of smectic liquid crystal screen by driving and
The voltage value that arrangement form changes occurs, is determined according to the composition of mixed layer and thickness, generally 5V or more.
Citing:Assuming that the liquid crystal display that smectic liquid crystal screen is one 128 × 256, i.e. H=128, V=256, are set in just
Stage beginning applies low-frequency high-voltage positive negative pulse stuffing to row, column, and Tfrost=20ms, m=100 apply row in the turntable driving stage
Add high-frequency and high-voltage positive negative pulse stuffing, Tscan=0.5ms, n=100.
As shown in figure 8, setting a=10, b=10, t1=1ms, t2=1ms, p=16, then take the present invention to be applied to being located at
The positive negative-going pulse of 40 pairs of the centre pulse pair for the low-frequency high-voltage positive negative pulse stuffing being added in row or column samples, and to each
When direct impulse, negative-going pulse sampling, average sample 16 only is carried out to the voltage value of the about 8ms periods at position among pulse
It is secondary.Also, 16 times are sampled, 2 maximum sampled values and 2 minimum sampled values is removed, makes even to remaining 12 sampled values
, to obtain sample mean, 80 sample means then can be obtained, then analysis obtains in this 80 sample means
Charge value of the minimum value as initial phase, represent smectic liquid crystal screen initial phase charge condition, if this is electric
Magnitude will can then take driving pulse caused by low battery of the corresponding measure to prevent smectic liquid crystal screen close to alarm threshold
It is abnormal that wave distortion causes display.
As shown in figure 9, setting c=20, d=20, then take the present invention to positive and negative positioned at the high-frequency and high-voltage being applied on row
The positive negative-going pulse of 30 pairs of the centre pulse pair of pulse samples, to each positive and negative primary to impulse sampling, to obtain 60
A sampled value, and for 60 sampled values, 10 maximum sampled values and 10 minimum sampled values are removed, remaining 40 are sampled
Value is averaged, and to obtain row sampled value, 128 row sampled values in this case can be obtained altogether during this brush screen, then
Analysis obtains charge value of the minimum value as the turntable driving stage in this 128 row sampled values, represents smectic liquid crystal screen and exists
The charge condition in turntable driving stage, if this charge value will can take corresponding measure to prevent smectic close to alarm threshold
It is abnormal to cause display for drive pulse waveform distortion caused by the low battery of phase liquid crystal display.
In practical applications, the electric power detection of initial phase and turntable driving stage can be combined, is totally obtained
208 sampled datas, are then minimized in 208 sampled datas, and the electricity of process is entirely driven as smectic liquid crystal screen
Magnitude.It, can if the charge value detected at this time will be close to alarm threshold at the end of brush screen of smectic liquid crystal screen
It takes corresponding measure and draws come the drive pulse waveform distortion during preventing the low battery of smectic liquid crystal screen from leading to next brush screen
Hair display is abnormal.
It is an advantage of the invention that:
The present invention is implemented on the original driving method applied to smectic liquid crystal screen, be can detect smectic liquid crystal screen and is existed
It shows information about power when image brush screen, reaches information about power of real time monitoring smectic liquid crystal screen during entire driving
Purpose so that smectic liquid crystal screen can carry out precautionary measures before low battery, prevent smectic liquid crystal screen from occurring because of driving pulse
Display caused by wave distortion is abnormal.
The present invention makes full use of the drive characteristic of smectic liquid crystal, is adopted during drive pulse waveform changes
Sample, real time monitoring smectic liquid crystal screen in initial phase and the information about power in the turntable driving stage, information about power with drive
Moving pulse waveform is closely related, and can really reflect the practical change of smectic liquid crystal screen drive pulse waveform during brush screen
Change situation.
The present invention can be by the electricity about each row or column that is detected to smectic liquid crystal screen when showing image brush screen
Information carries out processing analysis, to obtain the final information about power that this brush screen is related to, to realize monitoring smectic liquid crystal in real time
Shield electric quantity change situation during entire driving.
The present invention can not only be implemented on the common driving method of smectic liquid crystal screen, can also be real on various driving methods
It applies.
The above is presently preferred embodiments of the present invention and its technical principle used, for those skilled in the art
For, without departing from the spirit and scope of the present invention, any equivalent change based on the basis of technical solution of the present invention
Change, simple replacement etc. is obvious changes, all fall within the protection scope of the present invention.