Driving method of low-crosstalk and multi-gray-scale passive matrix alternating current electroluminescent display array and related device

Abstract

The invention relates to the technical field of power electronic devices, in particular to a low-crosstalk and multi-gray-scale passive matrix alternating current electroluminescent display array driving method and a related device. The driving method comprises the following steps: determining the amplitude of a first square wave used for inputting a selective traveling line, and determining the amplitude range of a second square wave according to the difference between the amplitude of the first square wave and three times of the threshold voltage and the difference between the amplitude of the first square wave and the threshold voltage by obtaining the threshold voltage of the alternating current electroluminescent display device; determining the maximum amplitude and the minimum amplitude of the second square wave from the amplitude range of the second square wave; and the average value of the sum of the maximum amplitude and the minimum amplitude is determined as the amplitude of the third square wave used for inputting the non-selective traveling line, so that the problem that crosstalk is easily caused when an existing driving method is used for driving display is solved, and the display effect of the alternating-current electroluminescent display array is improved.

Description

Technical Field

[0001] This invention relates to the field of power electronic device technology, and in particular to a driving method and related apparatus for a passive matrix AC electroluminescent display array with low crosstalk and multiple gray levels. Background Technology

[0002] Alternating Current Electroluminescent (ACEL) display devices are devices that emit light under alternating current. Unlike conventional electroluminescent devices, ACEL displays do not emit light under a constant voltage; instead, they emit light only when the applied voltage changes. Current ACEL displays employ passive matrix display technology to form an ACEL display array. The passive matrix consists of two sets of mutually perpendicular conductive lines: row lines and column lines. Pixels are formed at the intersections of the row and column lines.

[0003] Currently, existing methods for driving AC electroluminescent display arrays sequentially illuminate pixels in each row using a row-by-row gating approach to achieve display of the entire passive matrix of AC electroluminescent display devices. However, since pixels in the same column are interconnected, during the display process, the signal from one column can affect the illumination of all pixels in that column, leading to crosstalk and resulting in poor performance of the AC electroluminescent display array.

[0004] Therefore, how to reduce crosstalk in AC electroluminescent display arrays has become an urgent technical problem to be solved. Summary of the Invention

[0005] This invention provides a driving method and related apparatus for a passive matrix AC electroluminescent display array with low crosstalk and multiple gray levels, which solves the technical problem that existing driving methods are prone to crosstalk when driving the display.

[0006] This invention provides a driving method for an AC electroluminescent display array, wherein the AC electroluminescent display array is provided with row lines and column lines, and AC electroluminescent display devices are disposed at the intersections of the row lines and the column lines; the row lines include selected row lines and non-selected row lines; the driving method includes:

[0007] Determine the amplitude of the first square wave, which is used to input the selected traffic line;

[0008] Obtain the threshold voltage of the AC electroluminescent display device;

[0009] The difference between the amplitude of the first square wave and three times the threshold voltage is determined as the lower limit of the amplitude of the second square wave; and the difference between the amplitude of the first square wave and the threshold voltage is determined as the upper limit of the amplitude of the second square wave; the second square wave is used to input the column line; the lower limit of the amplitude of the second square wave and the upper limit of the amplitude of the second square wave constitute the range of the amplitude of the second square wave.

[0010] From the range of amplitude values ​​of the second square wave, determine the maximum and minimum amplitude values ​​of the second square wave;

[0011] The average of the sum of the maximum amplitude and the minimum amplitude is determined as the amplitude of the third wave, which is used to input the non-selectable pass line.

[0012] Optionally, the number of the second square waves is the same as the number of the column lines, and the method further includes:

[0013] The minimum display brightness of the AC electroluminescent display array is determined based on the amplitude of the first square wave and the maximum amplitude.

[0014] The maximum display brightness of the AC electroluminescent display array is determined based on the amplitude of the first square wave and the minimum amplitude.

[0015] Based on the maximum display brightness and the minimum display brightness, establish a gamma curve;

[0016] Obtain the grayscale display number of the AC electroluminescent display array, and determine the target grayscale brightness between the maximum display brightness and the minimum display brightness based on the grayscale display number and the gamma curve;

[0017] Based on the brightness of each target grayscale, determine the amplitude of each second square wave except for the second square wave with the largest amplitude and the second square wave with the smallest amplitude.

[0018] Optionally, the phase and duty cycle of the first square wave are obtained, and the corresponding first square wave is generated using the amplitude, phase and duty cycle of the first square wave;

[0019] Using the phase, the duty cycle, and the amplitude of each second square wave, the corresponding second square wave is generated;

[0020] Using the phase, the duty cycle, and the amplitude of the third wave, a corresponding third wave is generated;

[0021] Based on line-by-line scanning, each row line of the AC electroluminescent display array is sequentially selected as a passable row line, and the row lines that are not selected in a single scan are taken as non-passable row lines.

[0022] The first square wave is input into the selected row line, and each of the second square waves is input into the corresponding column line, and each of the third square waves is input into the non-selected row line.

[0023] Optionally, the first square wave, the second square wave, and the third square wave are bipolar square waves.

[0024] In another aspect, the present invention provides a driving device for a passive matrix AC electroluminescent display array with low crosstalk and multiple gray levels, the device including a processor and a memory;

[0025] The memory is used to store program code and transmit the program code to the processor;

[0026] The processor is used to execute the driving method described above according to the instructions in the program code.

[0027] In one aspect, the present invention also provides a driving system for an AC electroluminescent display array, comprising: a driving device, a row driver, and a column driver as described above;

[0028] The row driver is connected to each row side of the AC electroluminescent display array and is used to generate a first square wave and a third third wave, inputting the first square wave into the selected row line and inputting each of the third third waves into each of the non-selected row lines.

[0029] The column driver is connected to each column side of the AC electroluminescent display array and is used to generate each second square wave and input each second square wave into the corresponding column line.

[0030] Optionally, the first square wave, the second square wave, and the third square wave are bipolar square waves.

[0031] Optionally, both the row driver and the column driver include: a digital-to-analog conversion module and an operational amplifier module;

[0032] The digital-to-analog converter module is connected to the operational amplifier module and is used to acquire digital signals and convert the digital signals into low-voltage unipolar square waves of different amplitudes.

[0033] The operational amplifier module is used to convert the low-voltage unipolar square wave into bipolar square waves of different amplitudes.

[0034] Optionally, it may also include a main control module;

[0035] The main control module is connected to the digital-to-analog converter module and is used to output digital signals.

[0036] In another aspect, the present invention provides a computer-readable storage medium for storing program code for performing the method described above.

[0037] As can be seen from the above technical solutions, the present invention has the following advantages:

[0038] This invention provides a driving method for a low-crosstalk, multi-grayscale passive matrix AC electroluminescent display array. The AC electroluminescent display array is provided with row lines and column lines, and AC electroluminescent display devices are disposed at the intersections of the row lines and column lines. The row lines include selected row lines and non-selected row lines. The driving method includes: determining the amplitude of a first square wave, which is used to input the selected row lines; obtaining the threshold voltage of the AC electroluminescent display devices; determining the difference between the amplitude of the first square wave and three times the threshold voltage as the minimum amplitude of a second square wave; and determining the difference between the amplitude of the first square wave and the threshold voltage as the maximum amplitude of the second square wave; the second square wave is used to input the column lines; and determining the average of the sum of the maximum amplitude and the minimum amplitude as the amplitude of a third third wave, which is used to input the non-selected row lines.

[0039] This invention determines the amplitude of a first square wave used to input the selected row lines, and obtains the threshold voltage of the AC electroluminescent display device. The difference between the amplitude of the first square wave and three times the threshold voltage is determined as the minimum amplitude of a second square wave used to input the column lines. The difference between the amplitude of the first square wave and the threshold voltage is determined as the maximum amplitude of the second square wave used to input the column lines. The average of the sum of the maximum and minimum amplitudes is determined as the amplitude of a third square wave used to input the non-selected row lines. In practical applications, this limits the voltage of pixels in the selected rows that are not allowed to emit light, and the voltage of non-selected pixels, to within the threshold voltage, while allowing the remaining pixels in the selected rows to emit light normally. This reduces crosstalk caused by the column-side driving signal during the driving of the AC electroluminescent display array, thus improving the display effect of the AC electroluminescent display array. Therefore, the driving method of the AC electroluminescent display array with low crosstalk and multiple gray levels provided by the present invention solves the problem of crosstalk that is easily introduced when driving the display by the existing driving method, and improves the display effect of the AC electroluminescent display array. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a flowchart illustrating the steps of a driving method for a low-crosstalk, multi-grayscale passive matrix AC electroluminescent display array provided in Embodiment 1 of the present invention.

[0042] Figure 2 This is a schematic diagram of the structure of an AC electroluminescent display array provided in an embodiment of the present invention;

[0043] Figure 3 This is a schematic diagram of the driving signal waveform for selecting a pass-through pixel in an AC electroluminescent display array provided in an embodiment of the present invention.

[0044] Figure 4 This is a schematic diagram of the driving signal waveform of a non-selectable pass-through pixel in an AC electroluminescent display array provided in an embodiment of the present invention;

[0045] Figure 5 This is a flowchart illustrating the steps of a driving method for a low-crosstalk, multi-grayscale passive matrix AC electroluminescent display array provided in Embodiment 2 of the present invention.

[0046] Figure 6 This is a flowchart illustrating the steps of a driving method for a low-crosstalk, multi-grayscale passive matrix AC electroluminescent display array provided in Embodiment 3 of the present invention.

[0047] Figure 7 A schematic diagram of the 4-grayscale display effect of the AC electroluminescent display array provided in an embodiment of the present invention;

[0048] Figure 8 A schematic diagram of the structure of a driving system for an AC electroluminescent display array provided in an embodiment of the present invention;

[0049] Figure 9 This is a structural block diagram of the digital-to-analog converter chip and the high-voltage operational amplifier chip provided in the embodiments of the present invention;

[0050] Figure 10 The circuit structure diagram of the digital-to-analog converter chip and the high-voltage operational amplifier chip provided in the embodiments of the present invention;

[0051] Figure 11 This is another schematic diagram of a driving system for an AC electroluminescent display array provided in an embodiment of the present invention. Detailed Implementation

[0052] In the existing driving display method of AC electroluminescent display array, when driving each pixel row by row, it is necessary to apply square waves with different phases to the column side of the pixel in that row to achieve different brightness of each pixel. The square waves applied to the column side will affect not only the selected pixels, but also the non-selected pixels, causing the non-selected pixels that should not emit light to emit light, thus causing crosstalk.

[0053] Based on the above, embodiments of the present invention provide a driving method and related apparatus for a passive matrix AC electroluminescent display array with low crosstalk and multiple gray levels. By reducing the influence of column signals on non-selected pass pixels, the crosstalk of passive matrix column signals is controlled, thereby reducing crosstalk and improving the display effect of passive matrix AC electroluminescent display devices. This solves the technical problem that existing driving methods are prone to crosstalk when driving displays, and realizes a passive matrix AC electroluminescent display with low crosstalk and multiple gray levels.

[0054] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0055] like Figure 2 As shown, the AC electroluminescent display array involved in this embodiment of the invention is provided with row lines and column lines, and AC electroluminescent display devices (i.e., ...) are provided at the intersections of the row lines and column lines. Figure 2 (ACEL pixels in the image); the row lines include selected row lines and non-selected row lines.

[0056] It should be noted that an AC electroluminescent display array refers to a passive matrix driven array composed of AC electroluminescent devices. The passive matrix consists of two sets of mutually perpendicular conductive lines: row lines and column lines. Pixels are formed at the intersections of the row and column lines. The pixels in the passive matrix are the AC electroluminescent devices. The portion of a pixel connected to a row line is called the row side, and the portion connected to a column line is called the column side. The signal applied to a pixel is equal to the difference between the row-side signal and the column-side signal. This embodiment of the invention uses a row-by-row gating method, illuminating each row of pixels in the passive matrix at a certain frequency. Based on whether a pixel is gated, the pixels in the entire passive matrix can be divided into gated row pixels and non-gated row pixels. A gated row pixel is a pixel in a row that is gated, while a non-gated row pixel is a pixel in a row that is not gated, i.e., a pixel that is not allowed to emit light. Non-gated row pixels can be in multiple rows. Multi-grayscale display refers to a row of pixels where the brightness increases in a stepwise manner, such as from dark to bright or from bright to dark. In a passive matrix, each row can have multiple pixels, each column can have multiple pixels, pixels in each row share a row line, and pixels in each column share a column line.

[0057] Among them, the row lines connected by selected pass pixels are called selected pass row lines, and the row lines connected by non-selected pass pixels are called non-selected pass row lines. It can be understood that, for example... Figure 2 The number and position of selected and unselected passages shown are for illustrative purposes only and are not a limitation on the number and position of selected passages.

[0058] See Figure 1 The present invention provides a driving method for a low-crosstalk, multi-grayscale passive matrix AC electroluminescent display array, comprising:

[0059] 101. Determine the amplitude of the first square wave, which is used to input the selected line.

[0060] It should be noted that in practical applications, the first square wave is used as the input for selecting row lines, serving as the row drive signal for selecting pixels. The amplitude of the first square wave is the maximum amplitude of the square wave signal that the driver can output. The maximum amplitude of the square wave signal that the driver can output can be determined based on the driver used. For example, in practical applications, the amplitude of the signal output by the driver can be set.

[0061] 102. Obtain the threshold voltage of the AC electroluminescent display device.

[0062] It should be noted that the threshold voltage of an AC electroluminescent display device is used as the criterion for determining whether the device emits light. When the voltage of the AC electroluminescent display device is greater than the threshold voltage, the device is lit. When the voltage is less than or equal to the threshold voltage, the device is not lit.

[0063] 103. The difference between the amplitude of the first square wave and three times the threshold voltage is determined as the lower limit of the amplitude of the second square wave; and the difference between the amplitude of the first square wave and the threshold voltage is determined as the upper limit of the amplitude of the second square wave; the second square wave is used to input column lines; the lower limit of the amplitude of the second square wave and the upper limit of the amplitude of the second square wave constitute the range of the amplitude of the second square wave.

[0064] 104. From the range of amplitude values ​​of the second square wave, determine the maximum and minimum amplitude values ​​of the second square wave.

[0065] 105. The average of the sum of the maximum and minimum amplitudes is determined as the amplitude of the third wave. The amplitude of the third wave is used to input the non-selectable pass line.

[0066] It should be noted that in a passive matrix, the voltage amplitudes on both sides of a pixel are the amplitudes of the row-side signal minus the amplitudes of the column-side signal. When the voltage amplitudes on both sides of a pixel are greater than the threshold voltage of the AC electroluminescent display device, the pixel is lit; when the voltage amplitudes on both sides of a pixel are less than the threshold voltage of the AC electroluminescent display device, the pixel is not lit. The larger the voltage amplitudes on both sides of a pixel, the greater the brightness.

[0067] In this embodiment, as Figure 2 As shown, a first square wave is used to input the selected row lines, a second square wave is used to input the column lines, and a third square wave is used to input the non-selected row lines. The amplitude of the second square wave input to each column line is different, with one second square wave signal corresponding to each column line. Since a column line connects both the column side of the selected pixel and the column side of the non-selected pixel, selected and non-selected pixels connected to the same column line share the same second square wave. Therefore, in practical applications, the first square wave is input to the selected row lines, each second square wave is input to each column line, and each third square wave is input to the non-selected row lines, so that the row-side signal of the selected pixel is the first square wave, the row-side signal of the non-selected pixel is the third square wave, and selected and non-selected pixels connected to the same column line share the same second square wave. Based on this, the amplitude on both sides of the selected pixel is the amplitude of the first square wave minus the amplitude of the second square wave, and the amplitude on both sides of the non-selected pixel is the amplitude of the third square wave minus the amplitude of the second square wave. It is understood that in this embodiment, the first square wave, the second square wave, and the third square wave all have the same phase, and the duty cycle of the first square wave, the second square wave, and the third square wave all have the same duty cycle. The third square wave of each non-selected traffic line is the same.

[0068] Therefore, in practical applications, the brightness of selected pixels can be adjusted by changing the amplitude of the first square wave and the amplitudes of each second square wave, or simply by changing the amplitude of each second square wave. For the latter, the larger the amplitude of the square wave applied to the column side, the lower the brightness of the corresponding pixel; the pixel with the lowest brightness has a column-side signal amplitude of 0. The same principle applies to non-selected pixels.

[0069] Specifically, assume that the threshold voltage of the AC electroluminescent device in the passive matrix is ​​U. th The amplitude of the first square wave is U sel Then the lower limit of the amplitude of the second square wave can be determined as (U sel -3U th The upper limit of the amplitude of the second square wave is (U sel -U th The voltage range of the selected pass pixel is U. th~ 3U th Therefore, the amplitude range of the second square wave in this embodiment is (U sel -3U th )~(U sel -U th ).

[0070] Next, based on the actual display requirements, amplitudes are selected from the amplitude range of the second square wave as its maximum and minimum amplitudes. The maximum amplitude is greater than the minimum amplitude. For example, in a practical implementation, the upper limit of the amplitude can be selected as the maximum amplitude, and the lower limit as the minimum amplitude. Alternatively, the maximum and minimum amplitudes can be randomly selected, and multiple display experiments can be conducted based on these selected amplitudes. Based on the experimental feedback, the final selected maximum and minimum amplitudes are determined to meet the actual display requirements.

[0071] Therefore, taking the maximum amplitude of the second square wave as the upper limit of the amplitude of the second square wave and inputting the pixels that are expected to not emit light from the selected pixels as an example, the voltage amplitude on both sides of the input pixel is U. sel -(U sel -U th )=U thThe voltage does not exceed the threshold voltage, therefore the pixel does not emit light. Therefore, applying the second square wave with the largest amplitude to the selected pixels will prevent the pixel from emitting light, while pixels with second square waves of other amplitudes can emit light normally, satisfying the grayscale display requirement while reducing crosstalk from column signals. Therefore, this embodiment determines the difference between the amplitude of the first square wave and three times the threshold voltage as the lower limit of the amplitude of the second square wave; and determines the difference between the amplitude of the first square wave and the threshold voltage as the upper limit of the amplitude of the second square wave. This allows the application of the first square wave on the row side of the selected pixels and the application of second square waves with different amplitudes, duty cycles, and phases (the same as the first square wave) on the column side of the selected pixels. By utilizing the threshold characteristics of the AC electroluminescent device, the amplitude of the column-side signal of the non-emitting pixels is controlled within (U... sel -3U th )~(U sel -U th Within a certain range, crosstalk caused by column signals is reduced, and the selected pixels exhibit a grayscale display effect, achieving multi-grayscale display.

[0072] For non-selectable pixels, assuming the minimum amplitude of the determined second square wave is U c-min The maximum amplitude is U c-max Then the amplitude of the third wave is (U c-min +U c-max ) / 2.

[0073] When a third square wave is applied to the row side of the non-selected pass pixel and a second square wave is applied to each column line, the voltage amplitude on both sides of the non-selected pass pixel is controlled within U. th Within. Therefore, it can be seen that an amplitude of (U) is applied to the row side of the non-selected pass pixel. c-min +U c-max ) / 2, a third wave with the same duty cycle and phase as the first square wave, thereby controlling the voltage amplitude on both sides of the non-selected pass pixel within U. th Within this range, the voltage amplitude on both sides of the non-selected pixel is much lower than the threshold voltage, so the non-selected pixel does not emit light, further reducing crosstalk caused by the column signal.

[0074] Based on the above, this embodiment determines the amplitude of the first square wave used for inputting the selected row lines, and obtains the threshold voltage of the AC electroluminescent display device. The difference between the amplitude of the first square wave and three times the threshold voltage is determined as the minimum amplitude of the second square wave used for inputting the column lines. The difference between the amplitude of the first square wave and the threshold voltage is determined as the maximum amplitude of the second square wave used for inputting the column lines. The average of the sum of the maximum amplitude and the minimum amplitude is determined as the amplitude of the third square wave used for inputting the non-selected row lines. Thus, in practical applications, the voltage of pixels that are not allowed to emit light in the selected rows and the voltage of non-selected rows are limited to within the threshold voltage, while the remaining pixels that are allowed to emit light in the selected rows can emit light normally. Therefore, this embodiment determines the amplitude of the first square wave, limits the amplitude range of the second square wave based on the amplitude of the first square wave and the threshold voltage of the AC electroluminescent display device, and determines the amplitude of the third square wave based on the amplitude of the second square wave. This limits the voltage amplitude on both sides of each non-selected pixel to below the threshold voltage of the AC electroluminescent display device, reduces crosstalk caused by the column-side driving signal during the display of the AC electroluminescent display array, and improves the display effect of the AC electroluminescent display array.

[0075] Therefore, the driving method for a low-crosstalk, multi-grayscale passive matrix AC electroluminescent display array provided in this embodiment solves the problem of crosstalk that is easily introduced when driving the display by existing driving methods, and improves the display effect of the AC electroluminescent display array.

[0076] In a preferred embodiment, the first square wave, the second square wave, and the third square wave are bipolar square waves.

[0077] It should be noted that, compared to unipolar square waves, this embodiment uses bipolar square waves as the first, second, and third square waves, which can achieve higher brightness with the same square wave amplitude, thereby reducing the power consumption of the driving circuit.

[0078] In one application example, assume the passive matrix has 16 columns, divided into G0 and G15 columns. The selected row drive signal (i.e., the first square wave) has an amplitude of 50V and a threshold voltage of 20V. The column signal amplitude range is -10V to 30V, with a maximum amplitude of 30V and a minimum amplitude of 0V. The unselected row drive signal (i.e., the third square wave) has an amplitude of 15V. The relationship between the G0 column signal (i.e., the second square wave signal with the smallest amplitude), the G15 column signal (i.e., the second square wave signal with the largest amplitude), and the selected row drive signal is as follows: Figure 3 As shown, the relationship between the G0 column signal (i.e., the second square wave signal with the smallest amplitude), the G15 column signal (i.e., the second square wave signal with the largest amplitude), and the unselected row drive signal is as follows: Figure 4 As shown. By Figure 3 and Figure 4 As can be seen, the method provided in the embodiments of the present invention can reduce crosstalk caused by column signals.

[0079] The above is a driving method for a low-crosstalk, multi-grayscale passive matrix AC electroluminescent display array provided in Embodiment 1 of the present invention. The following is Embodiment 2 of the driving method for a low-crosstalk, multi-grayscale passive matrix AC electroluminescent display array provided in Embodiment 1 of the present invention. Based on Embodiment 1, Embodiment 2 provides a detailed description of the determination of the amplitude of each second square wave of each input column line.

[0080] Please see Figure 5 The present invention provides a driving method for a low-crosstalk, multi-grayscale passive matrix AC electroluminescent display array, comprising:

[0081] 201. Determine the minimum display brightness of the AC electroluminescent display array based on the amplitude and maximum amplitude of the first square wave.

[0082] It should be noted that, based on the amplitude of the first square wave, the maximum amplitude of the second square wave can determine the minimum voltage value among the selected pixels. Converting this minimum voltage value into brightness yields the minimum display brightness of the selected pixels.

[0083] 202. Determine the maximum display brightness of the AC electroluminescent display array based on the amplitude and minimum amplitude of the first square wave.

[0084] It should be noted that, based on the amplitude of the first square wave and the minimum amplitude of the second square wave, the maximum voltage value in the selected pixel can be determined. Converting this maximum voltage value into brightness will yield the maximum display brightness.

[0085] 203. Establish a gamma curve based on the maximum and minimum display brightness.

[0086] It should be noted that this step uses the maximum and minimum display brightness to construct a gamma curve with display brightness as the independent variable and gamma value as the dependent variable.

[0087] 204. Obtain the grayscale display count of the AC electroluminescent display array, and determine the target grayscale brightness between the maximum and minimum display brightness based on the grayscale display count and the gamma curve.

[0088] It should be noted that the grayscale display count refers to the number of grayscale levels that the AC electroluminescent display array needs to display. It can be set according to actual needs, such as 4 grayscale display, 5 grayscale display, etc.

[0089] The gamma value intervals corresponding to the maximum and minimum display brightness are divided into multiple gamma values ​​by the target number of times. Then, the gamma curve is used to inversely calculate the target grayscale brightness between the maximum and minimum display brightness. The target number is equal to the grayscale number minus 1.

[0090] In one example, taking a 5-grayscale display as an example, the gamma value corresponding to the maximum brightness (or minimum brightness) is divided into 4 equal parts to obtain 5 gamma values. The 3 gamma values ​​in the middle are input into the gamma curve, and the brightness corresponding to the 3 points in the middle of the maximum and minimum display brightness is derived by reverse calculation.

[0091] 205. Based on the grayscale brightness of each target, determine the amplitude of each second square wave except for the second square wave with the largest amplitude and the second square wave with the smallest amplitude.

[0092] It should be noted that in this embodiment, the maximum and minimum amplitudes of the second square wave are known. Therefore, this step determines the specific amplitudes of each second square wave within the range of the minimum and maximum amplitudes. Each target grayscale brightness corresponds to an amplitude; therefore, by converting each target grayscale brightness into its respective amplitude, the amplitudes of all second square waves except for the second square wave with the maximum and minimum amplitudes can be obtained.

[0093] This embodiment determines the minimum display brightness of the AC electroluminescent display array based on the amplitude and maximum amplitude of the first square wave; determines the maximum display brightness of the AC electroluminescent display array based on the amplitude and minimum amplitude of the first square wave; establishes a gamma curve based on the maximum and minimum display brightness; obtains the grayscale display number of the AC electroluminescent display array; determines the target grayscale brightness between the maximum and minimum display brightness based on the grayscale display number and the gamma curve; and determines the amplitude of each second square wave except for the second square wave with the maximum and minimum amplitude based on each target grayscale brightness. Thus, based on the requirement of multi-grayscale display, gamma correction is used to determine the brightness of the selected pixels, and the amplitude of each second square wave is determined accordingly. This provides data support for accurately generating the corresponding square wave signal, enabling the selected pixels to achieve multi-grayscale display in practical applications, meeting the display requirements of multi-grayscale display.

[0094] The above is a driving method for a low-crosstalk, multi-grayscale passive matrix AC electroluminescent display array provided in Embodiment 2 of the present invention. The following is Embodiment 3 of a driving method for a low-crosstalk, multi-grayscale passive matrix AC electroluminescent display array provided in Embodiment 2 of the present invention. Based on Embodiment 2, Embodiment 3 provides a detailed description of the generation and use of the first square wave, the second square wave, and the third square wave.

[0095] Please see Figure 6 The present invention provides a driving method for a low-crosstalk, multi-grayscale passive matrix AC electroluminescent display array, comprising:

[0096] 301. Obtain the phase and duty cycle of the first square wave, and generate the corresponding first square wave using the amplitude, phase and duty cycle of the first square wave.

[0097] It should be noted that the phase and duty cycle of the first square wave can be preset according to actual needs. This step obtains the phase and duty cycle of the first square wave, and uses the amplitude, phase, and duty cycle of the first square wave to generate the corresponding first square wave. It can be understood that the amplitude of the generated first square wave is equal to the amplitude determined in step 101, and the phase and duty cycle of the generated first square wave are equal to the phase and duty cycle obtained in step 301.

[0098] 302. Using the phase, duty cycle, and amplitude of each second square wave, generate the corresponding second square waves.

[0099] It should be noted that the phase and duty cycle of each second square wave generated in this step are the same as those of the first square wave. The amplitude of each generated second square wave is equal to the amplitude of each second square wave determined in Examples 1 and 2.

[0100] 303. Generate the corresponding third wave by using the phase, duty cycle and amplitude of the third wave.

[0101] It should be noted that the phase and duty cycle of the third wave generated in this step are the same as those of the first square wave. The amplitude of the generated third wave is equal to the amplitude of the third wave determined in Example 1.

[0102] 304. Based on progressive scanning, each row line of the AC electroluminescent display array is selected sequentially as a passable row line, and the row lines not selected in a single scan are taken as non-passable row lines.

[0103] 305. Input the first square wave into the selected row line, input each second square wave into the corresponding column line, and input each third square wave into the non-selected row line.

[0104] This embodiment employs a line-by-line scanning method, sequentially selecting each row of the AC electroluminescent display array according to a set scanning order. In each scan, only one row is selected as the selected row, while the remaining rows are designated as non-selected rows. The row lines corresponding to the selected rows are called selected row lines, and the row lines corresponding to the non-selected rows are called non-selected row lines. Furthermore, by inputting a first square wave into the selected row lines, inputting each second square wave into the corresponding column line, and inputting each third square wave into the non-selected row lines, crosstalk caused by the column-side driving signals during the display process of the AC electroluminescent display array is reduced, improving the display effect of the AC electroluminescent display array and enabling multi-grayscale display.

[0105] In one application example, a 4-grayscale display will be used as an example to further illustrate the effect of the driving method provided in this embodiment of the invention.

[0106] Assuming the AC electroluminescent display array is a passive matrix driven array composed of AC electroluminescent devices with a threshold voltage of 20V, and a row-by-row gating method is used for 4-grayscale display driving, with the row scan frequency set to 5kHz, the amplitude of the bipolar square wave applied to the row side of the selected pixel is 50V. Therefore, the maximum amplitude of the corresponding bipolar square wave on the column side is 30V, and the minimum is 0V. To achieve four different brightness levels, through Gamma correction, the amplitudes of the column driving square waves corresponding to the four different brightness levels are 30, 21, 10, and 0V, respectively, corresponding to brightness levels of 0.07nit, 0.17nit, 0.54nit, and 1.27nit. Applying these column driving square waves to each column side of the selected pixel, the grayscale display effect of the selected pixel is as follows: Figure 7 As shown.

[0107] For the non-selected row pixels, a bipolar square wave with an amplitude of 15V and the same phase and frequency as the column driving square wave is applied to the row side. In this way, the amplitudes of the square waves applied to the two sides of the non-selected row are 15V, 6V, 5V, and 15V, respectively, all of which are lower than the threshold voltage of the non-selected pixel. At this time, the light emission phenomenon of the non-selected pixel due to the influence of the column signal is weakened, thereby better controlling crosstalk.

[0108] As described above, the driving method provided in this embodiment of the invention utilizes the threshold characteristics of the light emission of the AC electroluminescent device to control the maximum amplitude of the column signal, thereby reducing crosstalk from the column signal in the AC electroluminescent display array. Then, a bipolar square wave with the same phase as the column signal and an amplitude half that of the column signal is applied to the row side of the non-selected pixels to further control the crosstalk caused by the column signal, thus reducing the crosstalk of the AC electroluminescent display array and improving its display effect. Furthermore, in this embodiment of the invention, a bipolar square wave is used to meet the light emission conditions of the AC electroluminescent device, and the brightness of the AC electroluminescent device is adjusted by controlling the amplitude of the square wave, thereby modulating the grayscale and realizing multi-grayscale display of the AC electroluminescent display array.

[0109] Figures 1 to 7 Any technical feature in the embodiments corresponding to any of the above items is also applicable to the embodiments of the present invention. Figure 8 The corresponding implementation examples will not be repeated hereafter.

[0110] The present invention also provides a driving device for a passive matrix AC electroluminescent display array with low crosstalk and multiple gray levels, the device including a processor and a memory;

[0111] The memory is used to store program code and transfer the program code to the processor;

[0112] The processor is used to execute the methods of any of the above embodiments according to instructions in the program code.

[0113] See Figure 8 The present invention provides a driving system for an AC electroluminescent display array, the driving system comprising: a driving device as described in the above embodiment (not shown in the figure), a row driver 1 and a column driver 2;

[0114] The row driver 1 is connected to each row side of the AC electroluminescent display array 3 to generate a first square wave and a third third wave, inputting the first square wave into the selected row line and inputting each third third wave into each non-selected row line;

[0115] The column driver 2 is connected to each column side of the AC electroluminescent display array 3 to generate each second square wave and input each second square wave into the corresponding column line.

[0116] In one specific embodiment, the first square wave, the second square wave, and the third square wave are bipolar square waves.

[0117] In one specific embodiment, a reference power supply 4 is also included;

[0118] Reference power supply 4 is connected to row driver 1 and column driver 2 respectively, and is used to provide reference voltage for row driver 1 and column driver 2.

[0119] In one specific embodiment, both row driver 1 and column driver 2 include: a digital-to-analog conversion module and an operational amplifier module;

[0120] The digital-to-analog converter module is connected to the operational amplifier module to acquire digital signals and convert them into low-voltage unipolar square waves of different amplitudes.

[0121] The operational amplifier module is used to convert low-voltage unipolar square waves into bipolar square waves of different amplitudes.

[0122] It should be noted that the structure of row driver 1 is the same as that of column driver 2, both including a digital-to-analog conversion module and an operational amplifier module. For example... Figure 7 As shown, the digital-to-analog conversion module includes a digital-to-analog conversion chip 11, and the operational amplifier module includes an operational amplifier chip. This embodiment uses a circuit structure combining the digital-to-analog conversion chip 11 and the high-voltage operational amplifier chip 12 as the row signal driver and column signal driver structure to achieve high-voltage bipolar square wave outputs of different amplitudes. The digital-to-analog conversion chip 11 converts the acquired digital signal into low-voltage unipolar square waves of different amplitudes. Then, the high-voltage operational amplifier chip 12 converts these low-voltage unipolar square waves of different amplitudes into high-voltage bipolar square wave signals of different amplitudes, thereby achieving pulse amplitude modulation. The digital signal can be an FPGA digital signal. It can be understood that pulse amplitude modulation technology is a technique that controls the display grayscale by adjusting the pulse amplitude.

[0123] The connection between the digital-to-analog converter chip 11 and the high-voltage operational amplifier chip 12 is as follows: Figure 8 As shown, the high-voltage operational amplifier chip 12 includes an operational amplifier 121 and its peripheral circuitry. Pins B1 to B8 of the digital-to-analog converter chip 11 are used to receive input data (i.e., digital signals), and the reference voltage pin V of the digital-to-analog converter chip 11... ref The digital-to-analog converter chip 11 is used to receive the reference voltage. The GND pin of the digital-to-analog converter chip 11 is used for grounding. The output pin Vout of the digital-to-analog converter chip 11 is connected to the peripheral circuit of the operational amplifier 121 and is connected to the operational amplifier 121 through the peripheral circuit.

[0124] Understandably, the high-voltage operational amplifier chip 12 of row driver 1 outputs first square waves and third square waves of different amplitudes. The high-voltage operational amplifier chip 12 of column driver 2 outputs second square waves of different amplitudes.

[0125] In one specific embodiment, it also includes a main control module;

[0126] The main control module is connected to the digital-to-analog converter module and is used to output digital signals.

[0127] It should be noted that, as Figure 9 As shown, the main control module includes a timing control circuit 5, an image memory 6, and a lookup table 7. The timing control circuit 5 is connected to the row driver 1, the image memory 6 is connected to the lookup table 7, the lookup table 7 is connected to the column driver 2, and the row driver 1 and column driver 2 are respectively connected to the AC electroluminescent display array 3. The timing control circuit 5 is used to output digital signals to the row driver 1. It can be understood that the AC electroluminescent display array 3 is composed of ACEL display devices.

[0128] The image memory stores the grayscale information of the image, and the lookup table stores the voltage amplitude of the second square wave corresponding to different grayscale levels. During the driving process, the grayscale information is first read from the image memory using the position information of the driving pixel as the address signal, and then the amplitude information is read from the lookup table and output using the read grayscale information as the address signal. The column driver generates the second square wave according to the received amplitude information and outputs it to each column of the AC electroluminescent display array.

[0129] In one example, the main control module can be implemented using an FPGA chip or any MCU chip.

[0130] The present invention also provides a computer-readable storage medium for storing program code for performing the methods of any of the above embodiments.

[0131] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0132] In the several embodiments provided in this application, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0133] Furthermore, in the various embodiments of the present invention, the functional units can be integrated into one processing unit, or each functional unit can be a separate physical entity, or two or more functional units can be integrated into one processing unit. The integrated unit described above can be implemented in hardware or as a software functional unit.

[0134] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0135] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0136] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A driving method for a low-crosstalk, multi-grayscale passive matrix AC electroluminescent display array, characterized in that, The alternating current electroluminescent display array is provided with row lines and column lines, and an alternating current electroluminescent display device is disposed at the intersection of the row lines and the column lines; the row lines include selected row lines and non-selected row lines; the driving method includes: Determine the amplitude of the first square wave, which is used to input the selected traffic line; Obtain the threshold voltage of the AC electroluminescent display device; The difference between the amplitude of the first square wave and three times the threshold voltage is determined as the lower limit of the amplitude of the second square wave; and the difference between the amplitude of the first square wave and the threshold voltage is determined as the upper limit of the amplitude of the second square wave; the second square wave is used to input the column line; the lower limit of the amplitude of the second square wave and the upper limit of the amplitude of the second square wave constitute the range of the amplitude of the second square wave. From the range of amplitude values ​​of the second square wave, determine the maximum and minimum amplitude values ​​of the second square wave; The average of the sum of the maximum amplitude and the minimum amplitude is determined as the amplitude of the third wave, which is used to input the non-selectable pass line.

2. The method according to claim 1, characterized in that, The number of the second square waves is the same as the number of the column lines, and the method further includes: The minimum display brightness of the AC electroluminescent display array is determined based on the amplitude of the first square wave and the maximum amplitude. The maximum display brightness of the AC electroluminescent display array is determined based on the amplitude of the first square wave and the minimum amplitude. Based on the maximum display brightness and the minimum display brightness, establish a gamma curve; Obtain the grayscale display number of the AC electroluminescent display array, and determine the target grayscale brightness between the maximum display brightness and the minimum display brightness based on the grayscale display number and the gamma curve; Based on the brightness of each target grayscale, determine the amplitude of each second square wave except for the second square wave with the largest amplitude and the second square wave with the smallest amplitude.

3. The method according to claim 2, characterized in that, Also includes: Obtain the phase and duty cycle of the first square wave, and generate a corresponding first square wave using the amplitude, phase, and duty cycle of the first square wave; Using the phase, the duty cycle, and the amplitude of each second square wave, the corresponding second square wave is generated; Using the phase, the duty cycle, and the amplitude of the third wave, a corresponding third wave is generated; Based on line-by-line scanning, each row line of the AC electroluminescent display array is sequentially selected as a passable row line, and the row lines that are not selected in a single scan are taken as non-passable row lines. The first square wave is input into the selected row line, and each of the second square waves is input into the corresponding column line, and each of the third square waves is input into the non-selected row line.

4. The method according to claim 3, characterized in that, The first square wave, the second square wave, and the third square wave are bipolar square waves.

5. A driving device for a low-crosstalk, multi-grayscale passive matrix AC electroluminescent display array, characterized in that, The device includes a processor and a memory; The memory is used to store program code and transmit the program code to the processor; The processor is configured to execute the driving method as described in any one of claims 1-4 according to the instructions in the program code.

6. A driving system for an alternating current electroluminescent display array, characterized in that, include: The drive device, row driver, and column driver as described in claim 5; The row driver is connected to each row side of the AC electroluminescent display array and is used to generate a first square wave and a third third wave, inputting the first square wave into the selected row line and inputting each of the third third waves into each of the non-selected row lines. The column driver is connected to each column side of the AC electroluminescent display array and is used to generate each second square wave and input each second square wave into the corresponding column line.

7. The drive system according to claim 6, characterized in that, The first square wave, the second square wave, and the third square wave are bipolar square waves.

8. The drive system according to claim 7, characterized in that, Both the row driver and the column driver include: a digital-to-analog conversion module and an operational amplifier module; The digital-to-analog converter module is connected to the operational amplifier module and is used to acquire digital signals and convert the digital signals into low-voltage unipolar square waves of different amplitudes. The operational amplifier module is used to convert the low-voltage unipolar square wave into bipolar square waves of different amplitudes.

9. The drive system according to claim 8, characterized in that, It also includes the main control module; The main control module is connected to the digital-to-analog converter module and is used to output digital signals.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store program code for performing the method as described in any one of claims 1-4.

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