Image quality improvement for liquid crystal displays

Used to improve the image quality of liquid crystal displays

A more complete understanding of the present invention and its advantages can be obtained with reference to the following description in conjunction with the accompanying drawings, in which:

Figure 1 is a schematic plan view of a part of the liquid crystal display;

Figure 2 is a schematic front view of a part of the liquid crystal display in Figure 1;

Figure 3 is a schematic block diagram of the liquid crystal display system;

Figure 4 is a schematic diagram of a part of the liquid crystal display in Figure 3;

Figure 5 is a schematic block diagram of an exemplary embodiment of the invention;

Figure 6 is a graph of pixel voltage level versus pixel position, which illustrates the operation of the prior art liquid crystal display system;

FIG. 7 is a diagram of pixel voltage level versus pixel position, which illustrates the operation of the liquid crystal display system according to the exemplary embodiment of the invention;

FIG. 8 is a diagram of pixel voltage level versus pixel position, which illustrates a liquid crystal display system according to another exemplary embodiment of the invention;

Figure 9 is a schematic flowchart of an exemplary embodiment of the invention;

Figure 10 is a schematic flowchart of another exemplary embodiment of the invention;

Figure 11 is a schematic flowchart of another exemplary embodiment of the invention;

Figure 12 is a schematic flowchart of another exemplary embodiment of the invention;

Figure 13 is a schematic flowchart of another exemplary embodiment of the invention; and

Figure 14 is a schematic block diagram of still another exemplary embodiment of the invention.

Field of invention

The present invention generally relates to liquid crystal display (LCD) devices, and more particularly relates to systems, devices, and methods for improving image quality by limiting the difference between grayscale values of adjacent pixels.

Description of previous skills

Liquid crystal displays (LCD) are generally used in devices such as portable televisions, laptop computers, control displays, and cellular phones to display information to users. In fact, LCDs act as pilot valves, that is, they allow the transmission of light in one state and block the transmission of light in the second state, and some include many intermediate stages for partial transmission. When used as a high-resolution information display, as in an application of the present invention, LCDs are typically arranged in a matrix structure with independently controlled display areas, which are called "pixels" (the smallest segment of the display). Each individual pixel is suitable for selectively transmitting or blocking from the backlight (transmission mode), from the reflector (reflection mode), or a combination of the two (transmission reflection mode).

LCD pixels can control the conversion of light of different wavelengths. For example, an LCD may have pixels that independently control the number of red, green, and blue transmissions. In some LCDs, voltage is applied to different parts of the pixel to control light passing through many parts of the stained glass. In other LCDs, different light systems are sequentially projected onto the pixel area in time. If the voltage is also changed sequentially in time, different intensities of different colors of light will be produced. By rapidly changing the wavelength of the light to which the pixel is exposed, the observer will see a combination of colors, rather than a continuous separation of colors. Many monochrome LCDs can lead to color displays. For example, a single red LCD can project its image onto the screen. If single green and single blue LCDs are aligned with red and projected, their combination will be the full range of colors.

The monochrome resolution of the LCD can be defined by the transmission and reflection of light at many different levels, and each pixel can perform the transmission or reflection in response to a control signal. When the user can distinguish the difference between the first level and the second level, the second level is different from the first level. LCDs with larger monochrome resolution are more clear to users.

The LCD is activated one at a time or multiple at the same time, pixel by pixel. The voltage is applied to each pixel area by charging the capacitor formed in the pixel area. The liquid crystal reacts to the charging voltage of the pixel capacitor by twisting, and thereby transmits a considerable amount of light. In some LCDs, an increase in drive voltage reduces transmission, but in other respects, it increases transmission. When multiple colors are used for each pixel, the composite voltage is applied to the pixels at different positions (different capacitance areas charged by the pixels) or time according to the LCD lighting method. Each voltage controls the transmission of special colors. For example, a pixel can only activate a blue light for transmission, while another for green light, and a third for red light. The most different light levels available for each color result in a greater number of possible light combinations. The colors can be combined from red pixels, green pixels, and blue pixels, and each pixel exists on a different LCD to produce any desired combined pixel color. The three LCDs (red-green-blue or RGB) are optically aligned, so that the synthesized light from each corresponding RGB pixel produces a distinct color pixel for each pixel in the LCD pixel matrix. The LCD pixel matrix is suitable for each photometer to display a video frame. Each optical frequency detector (RGB) generates a video frame. A series of video frames produce video images, which can change over time (such as movie videos).

Converts the complex digital signal representing the image or video into a voltage applied to charge the capacitance of each pixel of the LCD, which includes a circuit that can limit the monochrome resolution. The signal system necessary to drive a single color of the LCD is digital and analog. The selection signal that needs to be separated for each pixel is digital, but applying a driving voltage to charge the capacitor of the pixel to determine its light transmission is analogous.

Each pixel in the LCD array is addressed by row (vertical) drivers and column (horizontal) drivers. The row driver turns on the row switch, which connects the analog voltage representing the video input (the control voltage necessary for the desired liquid crystal twist) to the row, and the column driver turns on the second analog switch, which turns the The row is connected to the desired pixel.

The video input to the LCD is an analog signal, which is centered on a central reference voltage typically from about 6.5 to 8.0 volts. The voltage equal to or close to this central reference voltage is called "VCOM", and it is applied to the LCD glass cover electrode, which is a transparent conductive coating on the inner surface of the glass cover. The transparent conductive coating is typically indium tin oxide (ITO).

One frame of the video pixel operates at a voltage above the center reference voltage (positive inversion), and the next frame of the video pixel operates at a voltage below the center reference voltage (negative inversion). The alternating current between the positive and negative inversion results in a substantially zero net DC (direct current) bias at each pixel. This substantially reduces the phenomenon of "image sticking".

LCD technology has reduced the size of the display from a full-screen size to a microdisplay that is smaller than 1.3 inches diagonally, to a microdisplay that requires a magnification system. Microdisplays can be manufactured using semiconductor integrated circuit (IC) dynamic random access memory (DRAM) process technology. The microdisplay consists of a silicon substrate, a glass cover, and an intervening liquid crystal layer. The microdisplay is arranged in a matrix of pixels arranged in multiple columns and rows, where the intersection of the columns and rows defines the position of the pixels in the matrix. For incident light, each pixel is a liquid crystal cell on a mirror. By changing the state of the liquid crystal, the incident light can be made to change its polarization. The silicon substrate is an array of pixels, the pitch of which is basically 10-20 microns. Each pixel has a reflective surface that occupies most of the pixel area. The reflective surface is also an electrical conductor, which forms a pixel capacitor (common to all pixel capacitors in the pixel matrix) with an ITO layer of other thin plates like pixel capacitors. Since each pixel capacitor is charged to a certain pixel value, the liquid crystal between the thin plates of the pixel capacitor will "twist" or "twist in the opposite direction", which affects the polarization of the light incident on the pixel (reflected by the pixel mirror).

The microdisplay can have analog video signal input ("analog display") or digital video signal input ("digital display"). Analog displays are generally addressed in raster mode, while pixels in digital displays can be addressed in a random order like DRAM. Random access allows only the pixels that need to be updated to update, thus saving process time and related energy waste.

In a small LCD, especially in a microdisplay with a small pixel unit area compared to the area of the gap between the pixel units, there is a problem. In terms of magnitude, the fringe field between pixels is therefore significant, and the area affected by the fringe field is significant relative to all pixel areas. This leads to image degradation that greatly increases the severity of small LCDs and high drive voltages. Limiting the driving voltage is helpful, but it reduces the effective contrast of the LCD.

Summary of the invention

By providing a system, method, and device for improving the image quality of a liquid crystal display (LCD) by modifying the video source value written to the pixel to smoothly switch from a neighboring pixel to another pixel, the present invention overcomes The problems identified above and other shortcomings and deficiencies of the prior art. If the magnitude of the voltage conversion between adjacent pixels is too large, a large voltage conversion can produce a strong fringe field effect between adjacent pixels.

Liquid crystal silicon (LCoS) microdisplays are suitable for receiving video information from digital video data sources. The LCoS microdisplay can operate in, for example, a normal white twisted nematic LC mode. The rubbing direction can be selected so that disclination preferably occurs at the vertical pixel edges (between columns), such as a 60-degree twisting self-compensating reflective twisted nematic mode. If a source image with a black area surrounded by a bright gray area is displayed, a white line can be observed within the range of the gray area, and the gray area is adjacent to the black area on one side. However, on the other side of the black area, white spots can be observed. If you modify the source video image used for the pixels at the edge of the gray/black area, for example, normal black pixels written toward gray (brighter than black, but darker than normal gray), or written toward black Gray pixels (darker), then the synthesized LCD video image will subsequently have significantly less image distortion due to fringe effect fields. Because the photoelectric response of the liquid crystal has a slight gradient close to the saturation voltage used by the black pixels, the slight reduction in the black of such pixels, or the reduction in the brightness of the pixels adjacent to the black pixels, has a strong effect on the applied voltage.

For the purpose of illustrating the specific embodiments disclosed herein, the pixel voltage value representing black (the voltage value charged in the pixel capacitor) can be referred to as black or level A (OO input to the 8-bit DAC). _h ), and the pixel voltage value representing white can be called white or level D (input to the FF of the 8-bit DAC _h ). The gray level can be called gray or level C (larger than the black-OO of the 8-bit DAC) _h And smaller than the white-FF of 8-bit DAC _h ）。

In an exemplary embodiment of the invention, the video source data is fed into the shift register. The comparator analyzes the pixel value in the shift register, and limits all pixel values that are smaller than B and adjacent to the pixel value with at least gray level C to the actual black video value of level B (OO _h <B<C). Or, the image value less than the level B can be reduced by the factor K (increasing the gray level). If the level of the written edge gray level pixel has a gray level between C and D, here k, B The C series are the parameters selected for the favorite image. For continuous color LCD systems, only one shift register is needed. As far as the three-color (red-green-blue) LCD system is concerned, there are three shift registers available, and each of them is used for the various color parts of the RGBLCD.

In another exemplary embodiment of the present invention, the video source pixel data written to the front row is stored in the image memory. Therefore, as described herein, the pixel value data at the front row can be compared and modified. The video source pixel data of the row. Therefore, two adjacent row and column pixels can be compared so that any adjacent pixel will not be written to a voltage level that generates a fringe field large enough to cause image disclination.

In another exemplary embodiment of the invention, the magnitude changes in the voltage values of adjacent pixels will be reduced by averaging the required magnitude changes for a sufficient number of pixels, so that no adjacent pixels have larger than desired values. The voltage value of the magnitude changes. This can be obtained by dividing the voltage value of the input video data between adjacent pixels by the desired voltage value change to determine the "number of pixels", from which all the voltage values of the video data can be obtained Change without exceeding the desired voltage value change between any two adjacent pixels. This leads to more gradual changes in the voltage value, for example, the "step" adjacent pixel voltage value of most adjacent pixels changes until the entire video data voltage value changes.

Adjacent pixels on the same row, which can be described here together with adjacent pixels on adjacent rows. Video memory can be used to store the voltage values of pixels written to the front row and/or row, so that no adjacent pixels have a voltage difference large enough to cause field fringing effects. This is considered and in the present invention. Within the range.

The present invention is directed to a system for improving the image quality of a liquid crystal display (LCD). The system includes: a pixel matrix arranged in a plurality of rows and a plurality of columns, wherein an intersection of a column and a row is defined in the A position of a pixel in the matrix; at least one digital analog converter (DAC) having a digital input and an analog output; a plurality of row switches adapted to couple the analog output of the at least one DAC to the plurality of rows Each row; a plurality of column switches, which are adapted to selectively couple each column of the plurality of columns to the plurality of columns; row control logic, which is used to control the plurality of row switches; column control logic, which is used to control the plurality of rows Individual column switches; a video frame to grayscale conversion and pixel address logic, which is used to convert video information into LCD grayscale values and their corresponding pixel address positions; and video data comparator/modifier logic, the The video data comparator/modifier logic is adapted to receive the LCD grayscale value used by each pixel of the pixel matrix, wherein the grayscale values of adjacent pixels are compared, and if the value is between the grayscale values of adjacent pixels If the difference in is greater than the desired value, at least one of the grayscale values is modified so that the difference in the magnitude is not greater than the desired value; the video data comparator/modifier logic is suitable for All unmodified grayscale values and any modified grayscale values are sent to at least one DAC; the video frame-to-grayscale conversion and pixel address logic are suitable for sending the pixel address position to the row control logic and The column control logic.

The present invention is also directed to a method for improving the image quality of a liquid crystal display (LCD) comprising a matrix of pixels arranged in a plurality of columns and rows, wherein the intersection of the columns and rows defines the position of the pixels in the matrix. The method includes the following steps: Determine whether the grayscale value of the pixel is greater than the first reference value, and write the grayscale value to the pixel location, where if the grayscale value of the pixel is less than or equal to the first reference value, then the neighboring pixels Write the grayscale value of the adjacent pixel to the neighboring pixel, and if the grayscale value of the pixel is greater than the first reference value, then it is determined whether the grayscale value of the neighboring pixel is less than the second reference value, if so, then Then the second reference value is written to the neighboring pixel, and if not, then the grayscale value of the neighboring pixel is then written to the neighboring pixel.

The present invention is also directed to an operating method for improving the image quality of a liquid crystal display (LCD) comprising a matrix of pixels arranged in a plurality of columns and rows, wherein the intersection of the columns and rows defines the position of the pixels in the matrix, the method includes the following steps : Determine whether the grayscale value of the pixel is greater than the first reference value, and write the grayscale value to the pixel location, where if the grayscale value of the pixel is less than or equal to the first reference value, then it will be adjacent The grayscale value of the pixel is written to the neighboring pixel, and if the grayscale value of the pixel is greater than the first reference value, then it is determined whether the grayscale value of the neighboring pixel is less than a second reference value, if so , Then multiply the grayscale value of the neighboring pixel by k, and write the product to the neighboring pixel, and if not, then write the grayscale value of the neighboring pixel to the neighboring pixel.

The present invention is also directed to an operating method for improving the image quality of a liquid crystal display (LCD) comprising a matrix of pixels arranged in a plurality of columns and rows, wherein the intersection of the columns and rows defines the position of the pixels in the matrix. The method includes the following steps : Determine whether the grayscale value of the pixel is greater than the first reference value, and write the grayscale value to the pixel location, where if the grayscale value of the pixel is less than or equal to the first reference value, then it will be adjacent The grayscale value of the pixel is written to the neighboring pixel, and if the grayscale value of the pixel is greater than the first reference value, then it is then determined whether the grayscale value of the neighboring pixel is less than a second reference value, if so , Then divide the difference between the grayscale value of the pixel and the neighboring pixel by I, and store the result as N, and change the grayscale value of the next N neighboring pixel to be less than I, and change the The next N grayscale value is written to the next N neighboring pixel, and if not, then the grayscale value of the neighboring pixel is written to the neighboring pixel.

The technical advantage of the present invention is the improved image quality in the microdisplay. Another technical advantage is the smooth transition between pixel voltages that produce strong fringe field effects. For those who are familiar with the art from the following drawings, descriptions and the scope of the patent application, other technical advantages of the present invention will be easily understood. The various specific embodiments of the invention only achieve a part of the above advantages. For this invention, none of the advantages is absolute.

Schematic description

A more complete understanding of the present invention and its advantages can be obtained with reference to the following description in conjunction with the accompanying drawings, in which:

Figure 1 is a schematic plan view of a part of the liquid crystal display;

Figure 2 is a schematic front view of a part of the liquid crystal display in Figure 1;

Figure 3 is a schematic block diagram of the liquid crystal display system;

Figure 4 is a schematic diagram of a part of the liquid crystal display in Figure 3;

Figure 5 is a schematic block diagram of an exemplary embodiment of the invention;

Figure 6 is a graph of pixel voltage level versus pixel position, which illustrates the operation of the prior art liquid crystal display system;

FIG. 7 is a diagram of pixel voltage level versus pixel position, which illustrates the operation of the liquid crystal display system according to the exemplary embodiment of the invention;

FIG. 8 is a diagram of pixel voltage level versus pixel position, which illustrates a liquid crystal display system according to another exemplary embodiment of the invention;

Figure 9 is a schematic flowchart of an exemplary embodiment of the invention;

Figure 10 is a schematic flowchart of another exemplary embodiment of the invention;

Figure 11 is a schematic flowchart of another exemplary embodiment of the invention;

Figure 12 is a schematic flowchart of another exemplary embodiment of the invention;

Figure 13 is a schematic flowchart of another exemplary embodiment of the invention; and

Figure 14 is a schematic block diagram of still another exemplary embodiment of the invention.

Although the present invention allows various modifications and alternatives, specific exemplary embodiments thereof have been shown by examples in the drawings and are described in detail here. In any case, it should be understood that the description of this specific embodiment is not intended to limit the invention to the specific type disclosed. On the contrary, the invention covers the spirit and scope of the invention as defined by the scope of the patent application. All kinds of amendments, meanings and changes.

Detailed description of specific specific embodiments

The present invention is directed to a liquid crystal display (LCD), which includes a liquid crystal pixel matrix with light adjustment characteristics, and the characteristics are controlled by a voltage value stored in a capacitor that contains an area representing the pixels in the pixel matrix of the LCD. A plurality of digital-to-analog converters (DAC) are coupled to the pixel matrix through analog switches for voltage charging of the row. The column analog switch connects each column to the desired respective pixel capacitor sheet on the selected column, thereby converting the voltage value on the row to the respective pixel capacitor. The specific embodiment of the present invention improves the image quality of a liquid crystal display (LCD) by modifying the video voltage value written to the pixel capacitor, so as to reduce the magnitude change of the voltage transition from one adjacent pixel area to another pixel area. If the magnitude of the voltage transition between adjacent pixel areas is too large, the voltage transition can produce a strong fringe field effect between adjacent pixel areas, which is called "disclination". The details of the preferred embodiments of the present invention will now be summarized and described with reference to the drawings. The same elements in the drawings will be represented by the same numbers, and similar elements will be represented by the same numbers with different lowercase letter suffixes.

Referring to Fig. 1, a schematic plan view of a part of a liquid crystal display (LCD) is described. The LCD is generally represented by the number 102 and contains a plurality of pixels 108 (Figure 3). Each pixel has a separate pixel 108 capacitor sheet or "mirror" 84. The pixels 108 are arranged in a matrix array. In the exemplary embodiment of the invention, the pixel mirror 84 is disposed on the silicon substrate 82. The pixel mirror 84 forms a thin plate of the pixel capacitor, and the other thin pixel capacitor plates are formed of a transparent ITO (Indium Tin Oxide) layer. The substrate 82 may be a small semiconductor integrated circuit chip, which has transistors assembled therein, and part of these transistors can be connected to the pixel mirror 84. The space 86 between the pixel mirrors 84 is very small, and a large enough potential difference between adjacent pixel mirrors 84 can cause disclination in the liquid crystal material.

Referring now to FIG. 2, a schematic front view of a portion of the liquid crystal display in FIG. 1 is described. The LCD 102 includes a substrate 82, and the pixel mirror 84 is displaced on the surface of the substrate. The liquid crystal material 88 surrounds the pixel mirror 84. A transparent cover 92 made of glass or plastic, for example, has a transparent conductive coating 90, such as indium tin oxide (ITO), on one side thereof, and this layer forms other capacitor sheets for the pixel mirror 84. The outer surface 94 of the cover 92 is the visible part of the LCD 102. Typically, the light 96 flashes to the outer surface 94 of the LCD 102, and the liquid crystal material 88 modifies the light 98 reflected from the pixel mirror 84. Each pixel mirror 84 is combined with the ITO layer 90 with a unique voltage charge therebetween that modifies the torsion of the liquid crystal material 88 during the voltage charge period. The number of twists of the liquid crystal material 88 determines how much light 96 returns like the reflected light 98 (light polarization filter, not illustrated, is also applied in combination with liquid crystal to modify the light polarization). A clear and clear video frame will have smooth and clear light polarization transitions between the pixel mirrors 84. However, when the voltage difference between adjacent pixel mirrors 84 is too large, disclination may occur. The present invention overcomes these disclinations by limiting the magnitude of the voltage difference between adjacent pixel mirrors 84.

Refer to Figure 3, which illustrates a schematic block diagram of the liquid crystal display system. A high-level block diagram of the system for writing voltage values to pixels of a liquid crystal display system (LCD), which is generally represented by the number 100. The voltage value written to the pixel represents the frame of the image video. The voltage value controls the "twist" of the liquid crystal material in each pixel area, so that when the light flashes on or passes through the LCD, the light polarization and the light intensity that finally passes through the polarization filter are determined by the liquid crystal material on each pixel area of the LCD. Controlled by "twist".

For the purpose of illustration and demonstration, the LCD 100 described in FIG. 3 includes a pixel matrix 102 of M columns 106, N rows 104, and all M×N individually addressable pixels 108. The combination of the column control logic 110 and the row control logic 112 is used to select each pixel 108 for writing in the LCD 100, which is described in more detail here. The video-to-pixel conversion logic and look-up table (LUT) (hereinafter referred to as conversion logic) 114 performs necessary calculations and steps to convert the video frame image 116 into discrete digital values, and each digital value represents a pixel video voltage value. The digital value is sent to the digital analog converter (DAC) 120, 121, 122, and 123, and the pixel location address is sent to the column and row control logic 1I0 and 112. Any number of DAC that can be used according to the exemplary embodiments of the present invention is contemplated and falls within the scope of the present invention. The DACs 120, 121, 122, and 123 have outputs containing analog values, such as voltage or current, which are equivalent to digital input characters from the conversion logic 114.

Referring now to FIG. 4, a schematic block diagram of a part of the liquid crystal display system 100 in FIG. 3 is described. For illustration and demonstration purposes, a part of the pixel matrix 102 is represented as pixels 108aa-108dd (4×4 matrix), pixel column switches 300 to 333, and pixel row switches 290 to 293. The LCD operates by placing a desired voltage to charge each pixel 108aa-108dd of the LCD 100. The voltage charging at the pixel 108 causes the liquid crystal in the pixel area to change its "twisted" orientation, so that the light passing through the LCD 100 or reflected is affected thereby. The conversion logic 114 uses the received video frame information 116 to create the appropriate digital value sent to the DACs 120-123, and the DACs 120-123 represent the portion of the video frame at each pixel location. In addition, the conversion logic 114 combines each xy coordinate (column-row) position of these pixel voltage values, and sends it to the column control logic 110 and the row control logic 112.

The DACs 120-123 receive the digitally represented video pixel values from the conversion logic 114, and convert these digital representations into analog values, such as voltage or current, and the analog values are then applied to each corresponding row 104. Each of the pixels 108aa-108dd has a capacitor 178 combined with it, and each row of rows 0, 1, 2 (not shown), and 3 has a capacitor 180, 181, 182 (not shown), and 183 combined with it. . The capacitor 178 of each pixel may be different, and the capacitors 180, 181, 182, and 183 of each row are also different. In any case, the row capacitance, such as 180, is larger than the pixel capacitance, such as 178. The row capacitor is charged to the desired voltage value. The output of the DAC is connected to the row, thereby charging the row capacitor to the desired analog voltage, and each pixel in the selected column is connected to the corresponding row. Therefore, the voltage on the pixel will be substantially the same as the voltage on the corresponding row.

For example, when a pixel column is selected, the row is charged to a certain voltage, so the intersection point is the desired pixel to be charged. For example, when row switches 290-293 are closed, rows 0-3 are charged from DAC 120-123, respectively. When the column switch 300-303 is closed, the pixel 108aa _- The capacitor 178 of each 1o8dd is charged from row 0-3. Multiple DACs can be used to simultaneously charge the same number of capacitors in rows, and then the same number of switches in a column can be used to charge the capacitors of the same number of pixels from separate charging rows. The row control logic 112 and the column control logic 110 respectively control the operation of the row switches 290-293 and the column switches 300-333 for the groups of pixels 108aa-108dd. The other pixel groups 108 are controlled in the same way.

Reference is now made to Figure 5, which depicts a schematic block diagram of an exemplary embodiment of the invention. The DAC 120-123 is adapted to receive the digital amplitude information from the grayscale check table 304. The gray level check table 304 receives the pixel gray level information from the video data comparator/modifier logic 310. The video data comparator/modifier logic compares the gray level values of adjacent pixels and modifies one or two values to maintain the pixel voltage value The magnitude of the voltage in between changes within the desired limit. The video data comparator/modifier logic 310 receives the pixel gray level value 312 from the video frame to LCD pixel gray level conversion and pixel address logic 302. The video frame to LCD pixel gray scale conversion and pixel address logic 302 is adapted to convert the video information 116 into corresponding pixel information (gray scale and pixel address information). The pixel address information is sent to the LCD pixel address controller 306 (Figure 3) suitable for controlling the column control logic 110 and the row control logic 112. The video memory 308 can be used to store the modified image data. In addition, the video memory 308 can also be used to store the image data of the front row for comparison with the image data of this row. Before and/or after modification, etc., the video memory can also be used to store one or more adjacent pixel image data values.

In describing the exemplary embodiments disclosed herein, the pixel voltage value representing black (the voltage value charged on the pixel capacitor) can be referred to as black or level A (00 input to the 8-bit DAC). _h ), and the pixel voltage value representing white can be called white or level D (input to the FF of the 8-bit DAC _h ). The gray level can be called gray or level C (larger than the black-00 of the 8-bit DAC) _h And smaller than the white-FF of 8-bit DAC _h ). DACs with more or smaller input bits are considered here, and are within the scope of the present invention.

Refer to Figure 6, which describes a graph of pixel voltage level versus pixel position, which illustrates the operation of the prior art liquid crystal display system. The pixel at position 610 has a white voltage level of FF _h (Level D), and the neighboring pixel at position 618 has a black voltage level of 00 _h (Level A). The voltage magnitude difference between the pixels at positions 610 and 618 may be large enough to cause image degradation caused by the fringe field effect between the two pixels.

Referring to FIG. 7, it describes a graph of pixel voltage level versus pixel position, which illustrates the operation of the liquid crystal display system according to an exemplary embodiment of the present invention. The pixel at position 610 has a white voltage level of FF _h (Level D), and the neighboring pixel at position 716 has a voltage level (Level B) less than black (gray). Very close pixel location 718 has black voltage level 00 _h (Level A). The voltage magnitude difference between the adjacent pixels at positions 610 and 716, and between 716 and 718 is not large enough to cause image degradation caused by fringe field effects.

Referring back to FIG. 5, the video data comparator/modifier 310 may include a shift register and a comparator. The video source data 116 is fed from the video frame to the LCD pixel gray scale conversion logic 302 to the shift register in the video data comparator/modifier 310. The comparator in the video data comparator/modifier 310 analyzes the pixel value in the shift register and restricts all the pixel values that are smaller than B and adjacent to the pixel value with at least gray level C to the level B Substantial black video value (00 _h <B<C). Alternatively, the value of pixels smaller (darker) at level B can be reduced by the factor k (increasing the gray level). If the pixel written to the edge gray level pixel has a gray level between C and D, then The k, B, and C series are the parameters selected for the favorite image. For continuous color LCD systems, only one shift register is needed. For the three-color (red-green-blue) LCD system, there are three shift registers available, each of which is used for the various color parts of RGB LCDs.

In another exemplary embodiment of the invention, the video source pixel data written to the front row is stored in the video memory of the video data comparator/modifier 310, so, as explained here, it can be compared The pixel value data in the front row, and modify the video source pixel data in this row. Therefore, two adjacent row and column pixels can be compared so that any adjacent pixel will not write to a voltage level that generates a fringe field large enough to cause image degradation.

Referring to FIG. 8, which depicts a graph of pixel voltage level versus pixel position, it illustrates a liquid crystal display system according to another exemplary embodiment of the invention. The magnitude change in the voltage value of neighboring pixels will be reduced by averaging the required magnitude change for a sufficient number of pixels, so that no neighboring pixels have a voltage value change, and the voltage value change results in a greater than desired magnitude The voltage between adjacent pixels changes. This can be obtained by dividing the voltage value change of the input video data between adjacent pixels by the desired voltage value change. This determines the "number of pixels", where all changes in the voltage value of the video data can be obtained without exceeding the desired voltage value change between any two adjacent pixels. This leads to more gradual changes in the voltage value, for example, the "step" adjacent pixel voltage value of most adjacent pixels changes until the entire video data voltage value changes. The stepped voltage changes are described at pixel positions 812, 814, and 818.

The modification of the voltage values of neighboring pixels on the same column can be described here in conjunction with neighboring pixels on the neighboring column. Video memory can be used to store the voltage values written to the pixels on the front row and/or row, so that no adjacent pixels have a voltage difference large enough to cause the field edge effect, which is considered and is in the present invention Within the range.

With reference to Fig. 9, a schematic flow chart of an exemplary embodiment of the invention is described. The diagram in Figure 7 illustrates the operation of this exemplary embodiment. In step 902, the video data value is received. In step 910, the received video data value is detected to determine whether it is greater than the gray level C. If not, in step 904, the received video data value is written to its respective pixels. If it is greater than the gray level C, in step 906, the next received video data value is detected to determine whether it is less than the gray level B. If the next received video data value is greater than or equal to the gray level B, then in step 912, the next received video data value is written to the next respective pixel. If it is less than the gray level B, the next received video data value is then set to the gray level B, and the next individual pixel is written in step 912. The above steps are performed for each video data value before writing to each pixel.

Refer to Fig. 10, which is a schematic flowchart describing another exemplary embodiment of the present invention. In step 1002, the video data value is received. In step 1004, the received video data value is detected to determine whether it is greater than the gray level C. If not, then in step 1010, the received video data value is written to its respective pixels. If it is greater than the gray level C, then in step 1006, the next received video data value is detected to determine whether it is less than the gray level B. If the next received video data value is greater than or equal to the gray level B, then in step 1012, the next received video data value is written to the next respective pixel. If it is less than the gray level B, the next received video data value is then multiplied by a constant k, and in step 1012, it is written to the next individual pixel. The above steps are used to write each video data value before each pixel.

Referring to Fig. 11, a schematic flowchart of another exemplary embodiment of the present invention is described. The diagram in Figure 8 illustrates the operation of this exemplary embodiment. In step 1102, the video data value is received. In step 1104, the received video data value is detected to determine whether it is greater than the gray level C. If not, in step 1110, the received video data value is written to its respective pixel. If it is greater than the gray level C, then in step 1106, the next received video data value is detected to determine whether it is less than the gray level B. If the next received video data value is greater than or equal to the gray level B, then in step 1112, the next received video data value is written to the next respective pixel. If the gray level is less than B, then in the subsequent step 1108, the difference between the value of the next video data of video data is the value divided by I, and the junction if the storage is N. In step 1114, the next N video data value is changed to be less than 1. In step 1112, the next N video data value is written to the next N individual pixels. The above steps are performed to write each video data value before each pixel.

Referring to Fig. 12, a schematic flowchart of another exemplary embodiment of the present invention is described. In step 1202, the video data value is received. In step 1204, the received video data value is detected to determine whether it is greater than the gray level C. If not, then in step 1216, the next video data value in the front row is detected to determine whether it is greater than the gray level C. If not, then in step 1210, the received video data value is written to its respective pixels. If the video data value is greater than the gray level C, then in step 1206, the next received video data value is detected to determine whether it is less than the gray level B. If the next received video data value is greater than or equal to gray level B, then in step 1212, the next received video data value is written to the next respective pixel. If it is less than the gray level B, then set the next received video data value to the gray level B, and write it to the next individual pixel in step 1212. If the next video data value in the front row is greater than the gray level C, then the next received video data value is detected in step 1206 to determine whether it is less than the gray level B. If the next received video data value is greater than or equal to the gray level B, then in step 1212, the next received video data value is written to the next respective pixel. If it is less than the gray level B, then the next received video data value is set to the gray level B, and in step 1212, it is written to the next individual pixel. The above steps are performed to write each video data value before each pixel.

Reference is made to Fig. 13, which describes a schematic block diagram of an exemplary embodiment of the invention. The specific embodiment of the schematic block diagram illustrated in FIG. 13 is an exemplary implementation process of the flowchart in FIG. 9. Other implementation processes are equally effective, and take place in those who are familiar with general related skills and benefit from this disclosure. The pixel gray level value 312 can be received in the shift register 1300. The video data value can be stored in the shift register storage element 1302, and the next video data value can be stored in the shift register storage element 1304. The multiplexer 1306 is adapted to select the video data value, the next video data value, or the data value at level B. Once the input of the multiplexer 1306 constitutes a selection, the output of the multiplexer 1306 drives the digital-to-analog converter (DAC) 1308, which will charge the appropriate line, and the appropriate line is connected to the desired line for charging Pixels.

The multiplexer 1320 selects the video data value stored in the storage component 1302 or the next video data value stored in the storage component 1304. The output of the multiplexer 1320 is coupled to the first input of the comparator 1312. The multiplexer 1318 selects the reference level C1316 or the reference level B1314, and its output is coupled to the second input of the comparator 1312. The comparator 1312 compares the video data value to the reference level C with the next video data value to the reference level B. Based on these comparisons, the level write decision logic 1310 selects an appropriate video pixel data value for driving the DAC 1308. The selection from the decision logic 1310 is based on the flowchart shown in Figure 9.

Referring to Fig. 14, a schematic block diagram of another exemplary embodiment of the present invention is described. The specific embodiment of the schematic block diagram illustrated in FIG. 14 is an exemplary implementation process of the flowchart in FIG. 10. Other implementation processes are equally effective, and take place in those who are familiar with general related skills and benefit from the disclosure. The pixel gray level value 312 can be received in the shift register 1300. The video data value can be stored in the shift register storage element 1302, and the next video data value can be stored in the shift register storage element 1304. The multiplexer 1306 is adapted to select the video data value, the next video data value, or the next video data value multiplied by k. Once the input of the multiplexer 1306 constitutes a selection, the output of the multiplexer 1306 drives the digital-to-analog converter (DAC) 1308, which will charge the appropriate row, and the appropriate row is connected to the desired charging Pixels.

The multiplexer 1320 selects the video data value stored in the storage component 1302 or the next video data value stored in the storage component 1304. The output of the multiplexer 1320 is coupled to the first input of the comparator 1312. The multiplexer 1318 selects the reference level C1316 or the reference level B1314, and its output is coupled to the second input of the comparator 1312. The comparator 1312 compares the image data value to the reference level C with the next video data value to the reference level B. Based on these comparisons, the level write decision logic 1310 selects an appropriate video pixel data value for driving the DAC 1308. The selection from the decision logic 1310 is based on the flowchart shown in Figure 10.

The LCD and/or LCD system can be partially or completely assembled on a semiconductor integrated circuit or integrated circuit, which is considered by the present invention and falls within the scope of the specific embodiments of the present invention.

The present invention is therefore fully suitable for carrying out this objective, and obtaining the above-mentioned objectives and advantages, as well as others inherent here. Although the present invention has been described and illustrated, and the present invention is defined with reference to exemplary specific embodiments, such reference does not imply a limitation of the present invention, and no such limitation is inferred. Just like what happens to people who are familiar with general related skills and benefit from this disclosure, the present invention can be modified, changed, and has equivalent formation and functions. The specific embodiments described and illustrated in the present invention are only for explanation, and are not exhaustive of the scope of the present invention. Therefore, the present invention is intended to be limited only by the spirit and scope of the scope of the appended patent application, and to give equivalent substitute and complete recognition in all aspects.