CN1536552A - Liquid crystal display driving device and method - Google Patents

Abstract

A display driving device is suitable for driving a pixel of a display to switch from a first grayscale state to a second grayscale state. The device includes: a first storage device for storing a first voltage data for displaying the pixel in the first grayscale state; a second storage device for storing a driving voltage value table corresponding to various grayscale state conversions of the pixel; and a processing device for obtaining a corresponding pixel driving voltage from the driving voltage value table stored in the second storage device to drive the pixel of the display based on a second voltage data for displaying the pixel in the second grayscale state provided by an external circuit and the first voltage data stored by the first storage device.

Description

Liquid crystal display driving device and method

technical field

The present invention relates to a liquid crystal display driving device and method, in particular to a liquid crystal display driving device which increases the driving voltage of pixels of the liquid crystal display between different gray scales, so as to speed up the change speed of the gray scale state of the pixels.

Background technique

The currently known liquid crystal display structure includes a plurality of pixels (pixels) arranged in an array, and the state of the liquid crystal in each pixel changes according to the cross-voltage applied thereon, and the transmittance of the liquid crystal changes due to the change of the cross-voltage. In order to show the gray scale required on the screen. At present, the widely used driving method of liquid crystal display is to drive through the straight line part in the curve of its static voltage and liquid crystal (LC) transmittance. As shown in FIG. 1 , FIG. 1 is a schematic diagram of the relationship between the transmittance and the cross-pressure of an LC. Taking a 4-bit gray scale as an example, the transmittance of LC is divided into 16 gray scales G _on ~ G _off . Through the oblique line in Figure 1, the driving voltages V _on to V _off corresponding to the gray scales G _on to G _off are the cross voltages that should be available on the pixel when the gray scales G _on to G _off are to be obtained. . In a known driving method, a driver sequentially receives a series of gray scales, and then sequentially provides corresponding driving voltages to drive pixels in the display.

However, in actual situations, when a pixel has a specific cross-voltage, the pixel may not have a corresponding gray scale, and this phenomenon is particularly obvious when the cross-voltage of the pixel varies in a small range. In fact, for the time required for an LCD to change the gray scale, a small gray scale change usually takes more time than a large gray scale change, the reason is that the voltage across the pixel due to small changes. As mentioned above, due to the small voltage change, the gray scale response cannot meet the actual display requirements. As a result, the dynamic picture quality displayed on the LCD will be seriously affected.

Contents of the invention

In view of this, in order to solve the above problems, the main purpose of the present invention is to provide a liquid crystal display driving device and method, which uses the pixel voltage data on the current screen to compare with the pixel voltage data on the next screen, and according to a comparison table or A specific algorithm is used to find out the charging amount that can make the pixel have the fastest response.

In order to achieve the above object, the present invention proposes a display driving device, which is suitable for driving a display pixel from a first gray-scale state to a second gray-scale state, and the device includes: a first storage device for storing a first voltage data for the pixel to display the above-mentioned first gray-scale state; a second storage device for storing a driving voltage value table corresponding to various gray-scale state transitions of the pixel; and a processing device, According to a second voltage data provided by an external circuit for displaying the second grayscale state of the pixel and the first voltage data stored by the first storage device, from the storage in the second memory The driving voltage value table of the device obtains a corresponding pixel driving voltage to drive the pixels of the display.

In addition, the present invention proposes a display driving method, which is suitable for driving the pixels of the display to switch from the first grayscale state to the second grayscale state. The method includes the following steps: providing a first storage device, which pre-records pixels in each A driving voltage value table corresponding to the conversion of the gray scale state; the driving voltage value table includes a static driving voltage representing that the gray scale of the pixel does not change and a dynamic driving voltage representing a change in the gray scale of the pixel; a second storage device is provided, which storing a first driving voltage for displaying the first grayscale state for the pixel; and a second driving voltage for displaying the second grayscale state for the pixel and the first driving voltage, from the driving voltage The value table is looked up to obtain a corresponding pixel driving voltage to drive the pixels of the display.

Description of drawings:

In order to make the above-mentioned purpose, features and advantages of the present invention more comprehensible, a preferred embodiment is specifically cited below and described in detail with reference to the accompanying drawings.

FIG. 1 shows a schematic diagram of the relationship between the transmittance of a liquid crystal and the cross-voltage.

Fig. 2 shows a block diagram of a liquid crystal display driving device according to an embodiment of the present invention.

Explanation of reference symbols:

21～external circuit

22 ~ the first storage device

23 ~ second storage device

24～processing device

25～Display

Detailed ways

The liquid crystal display driving device and driving method for realizing the purpose of the present invention will be introduced below.

Referring to FIG. 2 , FIG. 2 shows a block diagram of a liquid crystal display driving device according to an embodiment of the present invention. The liquid crystal display driving device according to the embodiment of the present invention is used to drive the pixels of the display 25 to switch from the first grayscale state to the subsequent second grayscale state, which includes the following structures.

The data stored in the first storage device 22 is the first voltage data of the pixels of the display 25 in the first grayscale state, and the voltage data is recorded in the first grayscale state, the corresponding voltage value required by the pixel, the voltage value Refer to the relationship diagram shown in Figure 1.

The second storage device 23 is used to store a driving voltage value table corresponding to various grayscale state transitions of pixels. The driving voltage value table includes a static driving voltage representing a pixel grayscale that does not change and a dynamic driving voltage representing a pixel grayscale change. Voltage, which is built from experiments, simulation calculations, or historical records. It is generally known that the voltage range applied to the pixel by the driving circuit of the liquid crystal display is the voltage range between V _on and V _off , which is the so-called static driving voltage range of the pixel, as shown in Figure 1, where V _on and V _off are respectively used The static maximum light transmittance and the static minimum light transmittance (such as the brightest state and the darkest state) voltage values of the static display of the pixel. The voltage value range corresponding to the dynamic driving voltage includes the voltage value range corresponding to the static driving voltage and other voltage value ranges, and its upper limit is the maximum voltage value that the pixel can withstand. Since the dynamic driving voltage conversion interval is greater than the static driving voltage conversion interval; that is, the dynamic driving voltage conversion interval will be greater than the V _on to V _off interval. As mentioned above, the time required for changing the gray scale will be shorter as the cross-voltage borne by the pixel increases, and the allowable voltage conversion value is determined according to the experimental simulation calculation here to accurately allow the transmittance to reach the predetermined value. Gray scale, to avoid excessive charge and discharge of pixels. Similarly, the second voltage data can refer to the relationship diagram shown in FIG. 1 . In this way, the driving voltage values between different gray scale states can be obtained.

The processing device 24, for example, a digital signal processor (Digital Signal Processor), an addressing circuit or a divider, etc., is used to receive the second voltage data provided by the external circuit 21 to display the second grayscale state of the pixel and The first voltage data stored in the first storage device 22 is used to obtain the corresponding pixel driving voltage from the driving voltage value table stored in the second storage device 23 to drive the pixels of the display 25, or to drive the pixels of the display 25 according to the desired pixel display. For the second driving voltage in the two-gray-scale state and the first driving voltage stored in the second storage device 23 , the corresponding correction value of the pixel driving voltage is obtained from the driving voltage value correction table stored in the first storage device 22 . The processing device 24 corrects the second driving voltage according to the pixel driving voltage correction value to generate an actual pixel driving voltage to drive the pixels of the display 25. When the first and second grayscale states are the same, the pixel driving voltage correction value is zero; On the contrary, when the first and second gray scale states are different, the correction value of the pixel driving voltage is not zero. Therefore, when the first driving voltage is less than the second driving voltage, the actual pixel driving voltage is the sum of the second driving voltage and the correction value of the pixel driving voltage; otherwise, when the first driving voltage is greater than the second driving voltage, the actual pixel driving voltage is The pixel driving voltage is the difference between the second driving voltage and the correction value of the pixel driving voltage.

In addition, after the processing device 24 outputs the adjusted second voltage data to the pixels of the display 25 , it may also store the unadjusted second voltage data in the first storage device 22 to replace the first voltage data. The absolute value of the difference between the pixel driving voltage correction value and the first voltage obtained from the driving voltage value correction table is greater than the absolute value of the difference between the second voltage and the first voltage. That is, in this embodiment, by increasing the change amount between the pixel driving voltage correction value and the first voltage, the change speed of the gray scale state of the pixel can be effectively accelerated.

Furthermore, the processing device 24 can also use the driving voltage value correction table to convert the driving voltage from low to high. In the embodiment of the present invention, the external circuit 21 provides six-bit voltage data to the processing device 24 to display six-bit image data as an example. However, in the above-mentioned embodiment, although the external circuit only provides six-bit The voltage data is sent to the processing device 24, but the second storage device 23 can be used to compare the low bit to the high bit with the processing device 24, for example, convert six bits into seven bits, and cut the bias precision of the dynamic drive finer to achieve more accurate drive.

Although the present invention is disclosed above with preferred embodiments, it is not intended to limit the scope of the present invention. Those skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore The protection scope of the present invention depends on the appended claims.

Claims (7)

1. A display driving device, which is suitable for driving a pixel of a display to switch from a first gray-scale state to a second gray-scale state, the device comprising: A first storage device, used for storing a first voltage data for displaying the pixel in the above-mentioned first grayscale state; a second storage device for storing a table of driving voltage values corresponding to various grayscale state transitions of pixels; and A processing device, used for storing the second voltage data provided by an external circuit and the first voltage data stored in the first storage device according to the second voltage data for displaying the second grayscale state of the pixel and the first storage device. The driving voltage value table of the second storage device obtains a corresponding pixel driving voltage to drive the pixels of the display. 2. A display driving device, which is suitable for driving a pixel of a display to switch from a first gray-scale state to a second gray-scale state, the device comprising: A first storage device, used to store a driving voltage value table corresponding to the conversion of various gray scale states of the pixel; the above driving voltage value table includes a static driving voltage representing that the gray scale of the pixel does not change and a driving voltage representing the change of the gray scale of the pixel Dynamic drive voltage; A second storage device, storing a first driving voltage for displaying the pixel in the first gray-scale state when the pixel is in the first gray-scale state; and A processing device, based on a second driving voltage for displaying the second grayscale state of the pixel and the first driving voltage stored in the second storage device, from the value of the driving voltage stored in the first storage device The table look-up table obtains a corresponding pixel driving voltage to drive the pixels of the display. 3. A display driving device, adapted to drive a pixel of a display to switch from a first grayscale state to a second grayscale state, the device comprising: a first storage device, used for storing a driving voltage value correction table corresponding to the conversion of the pixel in various gray scale states; A second storage device, storing a first driving voltage required to make the pixel display the above-mentioned first grayscale state; and A processing device, based on a second driving voltage for making the pixel display the second grayscale state and the first driving voltage stored in the second storage device, from the driving voltage stored in the first storage device to The value correction table looks up a corresponding pixel driving voltage correction value; the processing device uses the pixel driving voltage correction value to correct the second driving voltage, and generates an actual pixel driving voltage to drive the pixels of the display. 4. A display driving method, which is suitable for driving a pixel of the display to convert from a first grayscale state to a second grayscale state, the method comprising the following steps: A first storage device is provided, which pre-records a driving voltage value table corresponding to the conversion of various gray-scale states of the pixel; the above-mentioned driving voltage value table includes a static driving voltage representing no change in the gray-scale of the pixel and a static driving voltage representing a change in the gray-scale of the pixel The dynamic driving voltage; providing a second storage device, which stores a first driving voltage for displaying the pixel in the above-mentioned first grayscale state; and According to a second driving voltage for displaying the second grayscale state of the pixel and the first driving voltage, a corresponding pixel driving voltage is obtained from the driving voltage value table to drive the pixels of the display. 5. A display driving method, which is suitable for driving a pixel of the display to convert from a first grayscale state to a second grayscale state, the method comprising the following steps: A first storage device is provided, which stores a driving voltage value correction table corresponding to the conversion of pixels in various gray scale states; providing a second storage device for storing a first driving voltage required to make the pixel display the above-mentioned first grayscale state; According to a second driving voltage for making the pixel display the second grayscale state and the first driving voltage, look up a corresponding pixel driving voltage correction value from the driving voltage value correction table; and The second driving voltage is corrected by using the correction value of the pixel driving voltage to generate an actual pixel driving voltage to drive the pixels of the display. 6. A display driving method, which is suitable for driving pixels of the display to convert from a first grayscale state to a second grayscale state, the method comprising the following steps: receiving a first driving voltage for displaying the pixel in the first grayscale state; receiving a second driving voltage for displaying the pixel in the above-mentioned second grayscale state; and According to the above-mentioned first and second driving voltages, a corresponding pixel driving voltage is obtained from a pre-recorded table of driving voltage values corresponding to the conversion of various gray-scale states to drive the pixels of the display; the above-mentioned driving voltage values The table includes a static driving voltage representing no change in the gray scale of a pixel and a dynamic driving voltage representing a change in the gray scale of a pixel. 7. A display driving method, which is suitable for driving a pixel of the display to convert from a first grayscale state to a second grayscale state, the method comprising: receiving a first driving voltage for displaying the pixel in the first grayscale state; receiving a second driving voltage for displaying the pixel in the above-mentioned second grayscale state; According to the above-mentioned first and second driving voltages, obtain a corresponding pixel driving voltage correction value from a pre-recorded pixel driving voltage correction value table corresponding to various gray scale state transitions; and The second driving voltage is corrected by using the correction value of the pixel driving voltage to generate an actual pixel driving voltage to drive the pixels of the display.

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