TW201029447A - Apparatus and method for compensating image signal and liquid crystal display using the same - Google Patents

Abstract

An apparatus and a method for compensating an image signal and a liquid crystal display using the same are provided. The apparatus includes an over-sampling unit and a compensating unit, wherein the over-sampling unit sequentially outputs a first pixel sampling signal, a mid sampling signal and a second pixel sampling signal by sampling the image signal. The compensating unit corrects the second pixel sampling signal with a compensation value which is generated according a differential value between the mid sampling signal and the first sampling signal.

Description

201029447 ------乂1TW 24869twf.doc/n VI. Description of the Invention: [Technical Field] The present invention relates to an image signal compensation device, and more particularly to an analog transmission interface Image signal compensation device. [Prior Art] A common transmission interface between a computer and a display, such as a video graphics array (VGA), also known as a D-SUB interface, or a color difference (YPbPr) interface, is transmitted by analog signals. The halogen data 'utilizes voltage changes to represent different gray scale values. Due to the increasing resolution of the display, the sampling time of the gray scale of the pixel is shorter, so when the voltage conversion capability of the computer or image source is insufficient, the gray scale voltage cannot be converted in the sampling period. The grayscale data received by the display is distorted, causing distortion such as cross talk. Taking a display with a resolution of 1920*1200@60Hz as an example, the sampling interval of each pixel is 6 ns, indicating that the image source must be converted in 6 ns to complete the conversion of the gray scale data, otherwise the display reads The prime order data will be distorted. In general, a computer requires about 2 ns to 3 ns to be successfully converted, so in this case, the higher the resolution of the resolution setting, the more severe the distortion. Since the current interface between the computer and the display mostly uses a VGA" surface, digital transmission interfaces such as a digital video interface (suppressing visuai, dvi) or a high-definition multimedia interface (High_Defmiti〇n Multimedia hterface 'HDMI) are not yet fully popular. Therefore, for 4 zL 1TW 24869ΐ\ν£ά〇ς/ιι 201029447, it is very important to use the VGA interface axis indicator to prevent image distortion by using the analog image ##. [Summary] The image compensation device and method utilize the amount of change between the previous ! and the intermediate sampling signal to infer that the currently required compensation value 'make the sample value of each gray scale voltage closer to the correct gray, avoiding the fine The picture is distorted. The ir oblique ir is also proposed - a kind of liquid crystal display 11, the image signal compensation loading display ===:: and then through the image processing unit into the complement = compensation device 'including oversampling unit sequence rounded -昼素早: It is used to sample the analog image signal and according to the signal. The compensation unit “takes the change of the second 昼 取 输出 输出 输出 输出 输出 输出 用以 用以 用以 用以 用以 用以 用以The sampling unit includes a clock single unit wheel (four)-transmission p two-two-class two-class ratio converter. The clock signal and the second clock signal = and::=, where the first-clock signal: the signal, and the second analog numeral; the second symbol f-pixel takes the intermediate sampling signal. And (4) according to the second clock signal rotation in the present invention - the embodiment, the clock unit includes a phase-locked loop 舆 5 1TW 24869twf_ doc / n 201029447 = phase shifter, which makes the phase-lock converter The output-time clock is coupled to the analog-type digital loop and the second analog-digital converter is switched to the phase-locked signal. And for outputting the second clock. In an embodiment of the invention, the phase difference of the signal is 18 degrees. The first clock signal and the second clock are in the other embodiment t, the analog input, the analog digital converter and the multiplexer include a clock single clock signal, and the analog digital converter teaching data It is responsible for outputting the multiplier and sequentially outputting the first clock signal of the first pixel sampling signal, and sampling the signal. The multiplexer = and the first pixel sampling signal, the second element, and the thief are used to rotate the other implementation of the present invention, the wide S#u and the intermediate sampling signal. In the case of 4 cases, the above compensation The early several, the search unit and the second operation k are transported to the oversampling unit, and are lightly connected to the out-difference signal according to the different unit, and the search unit is used to determine the compensation value of the second pixel sampling signal. In an embodiment of the present invention, the foregoing table is used to store a correspondence between a difference signal and a compensation value. F. In an embodiment of the present invention, the above-mentioned over-receiving reception analog image In addition, in the embodiment of the present invention, the above connector (4)) has a fine_reward color =:) = 6 iaITW 24869twf.doc/n 201029447 connector. Analogy ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ Signal and second pixel sampling signal; sampling according to the first element < Lu The amount of change of the intermediate sampling signal is rotated by a compensation value; and the second enthalpy sampling signal is modified by the compensation value. In the present invention - the embodiment wherein the sampling is based on the first 昼 - -== In the step of outputting the compensation value, the invention further provides a liquid crystal display, comprising: == setting and - image processing unit, wherein the connection; using '• for taking/relying the reliance wire to the connector, The first pixel sampling signal and the middle are called: $ according to the sampling signal; the image processing === = and according to the second pixel sampling signal display - integration = reduction of the above image signal compensation device system 7 201029447

^ITW 24869twf.doc/n The present invention infers the compensation value required for the current pixel sampling signal based on the variation of the previous pixel sampling signal and the intermediate sampling signal, and compensates each pixel sampling signal by the compensation. Avoid showing page distortion. In addition, the present invention can establish a corresponding lookup table according to different computer and display specifications, so that the compensation of the pixel sampling signal is faster and more accurate. In order to make the above features and advantages of the present invention more obvious, the following

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments, together with the drawings, are described in detail below. Embodiments First Embodiment

1 is a block diagram of an image signal compensating apparatus according to a first embodiment of the present invention. The image signal compensating apparatus (referred to as a compensating apparatus) 1 includes an oversampling list = H0 and a patching unit it 12G 'where the compensating unit 12 is connected Oversampling early = 110. The oversampling unit UG will rely on the pure lion image signal, 彳τ oversampling (Gvef sampling) to obtain the 昼 转 转 signal ds disk MS. The compensation unit 12G compensates the current j sampling domain DS according to the amount of change of the pre-alloy signal and the corresponding intermediate sampling signal MS, so that the output pixel sampling signal DS is closer to the correct human fire I5 white value-analog image signal. As, for example, is the interface or; the ι surface represents the gray scale voltage of the gray scale of the alizarin. Section. The Jingxi Zhao s step illustrates the circuit H of the compensation device as shown in Fig. 2A, and Fig. 2A. The oversampling unit UG includes the analogy number unit 115, and the clock unit is forced by the phase lock 129, η1, and 夕U7. Composition. The compensation unit 120 includes an operation unit and a search unit 126, wherein the operation unit (2) is connected to the class 8 201029447wW 24869twf.doc/n than the rotation of the digital converters 112, 114, and the output of the digital converter 112 is analogous, 杳杓w 124 is coupled between the units m and 122. Finding the FF is connected to the operation. The phase-locked loop 116 is based on the reference clock, the number (5), and the first-clock signal CK1 is transmitted via the phase-shifted pulse signal (5). The analog-to-digital converters 112, ι4 4 subscribe to the received analog image number 2 according to the first eo number (5) and the fourth pulse signal CK2. Since the phase shifter 117 of the present embodiment has (10) production, the phase difference between the first clock signal cki and the second clock signal CK2 and ^8 degrees is thus analogous to the sampling point of the digital converters 112, 114. The difference is half a cycle. The analog digital converter 112 samples with the analog image signal 曰8 8 pixel conversion period, so the output pixel sample signal DS represents gray scale data. The intermediate-to-U sampling signal MS sampled by the analog-to-digital converter 114 is located between adjacent pixel sampling signals DS.

If the first pixel sampling signal DS1 and the second pixel sampling signal DS2 are not adjacent to the gray scale data, the intermediate sampling signal MS1 indicates that a half sampling period has elapsed after the first pixel sampling signal DS1 is obtained ( That is, the data sampled after the second clock signal CK2) is matched, and the second pixel sample signal DS2 is after one sampling period (ie, the first clock signal CK1) after the first pixel sampling signal DS1 is obtained. The sampled gray scale data. Based on the first pixel sampling signal DS1 and the corresponding intermediate sampling signal MSI' computing unit 122, the voltage variation of the analog image signal as can be calculated, and then a difference signal DMS is rotated. The difference signal DMS can represent the amount of voltage change of the analog image signal AS during the first half of the voltage conversion. 9 ▲1TW 24869twf.doc/n 201029447 The secret is in the VGA to call the Y pulse, the value of the 昼素岐 is the pressure value, so the analog image signal AS is sampled, the bit data can represent the gray level of its individual elements. value. Therefore, the two DMSs can also indicate the slope of the current image of the 継 image signal. When the sampling period is short, the analog image transmitted by the system end will not reach the voltage value within the sampling period because of the driving capability. At this time, the searching unit 126 corrects the compensation value required for the second pixel sampling signal DS2 according to the difference signal = and then corrects the second pixel sampling signal DS2 via the arithmetic unit 124. Therefore, the second pixel sampling signal output by the shipment & is closer to the analog image (4) the grayscale value actually transmitted by the AS. * The third element age DS3 will take the difference signal between the f sample and the second sample Ds; to obtain the required compensation value, and then correct it by the operation unit 124 and then input it. The rest of the pixels are complemented by the __ analog, which is no longer in the display. The compensation device can be set between the connector and the image scaler, or directly integrated into the image scaler, which can enhance the display. Surface quality. Next, the step-by-step diagram illustrates the relationship between the voltage change of the analog image signal as and the sampled signal. Referring to FIG. 2B, FIG. 2B shows that the analog image signal AS is converted from grayscale 0 to grayscale 255. The sampling period of the first-clock signal CK1 is solved at time τ, and the sampling point of the second clock signal CK2 is at time τ/2. When the analog image signal AS changes, the analog-to-digital converter 114 first samples the analog image signal as at the time T/2 according to the second time, Z1TW 24869twf.doc/n 201029447 pulse signal CK2'. It is the gray scale voltage VI, that is, expressed by the intermediate sampling signal MSI described above. Then, the analog-to-digital converter 112 samples the analog image signal AS at time D, and the sampled voltage value is a gray scale voltage V2, that is, represented by the second sampling signal DS2, and the first sampling signal DS1 = The table is not grayscale 0. Since the analog image lupus signal AS is converted from grayscale 〇 to grayscale 255 by a high resolution display setting, the time normally required to be greater than the = sample time is therefore analogized to the second sampled signal sampled by the digital converter 112. DS2 has not reached the gray level 255 to be transmitted. The second sampling signal DS2 must be "compensated" to reach the actual desired gray level value. The differential signal DMS outputted by the intermediate sampling signal MS1 and the first sampling signal DS1 represents the gray scale voltage vi. The voltage difference between the gray voltage and the voltage G, that is, the search unit 126 = infers the difference between the gray scale voltage V3 and the gray scale voltage ν2 according to AVI and €3 'is also Δ" 'to correct the second Sample signal DS2. The one-of-a-kind DS2 is originally equal to the gray-scale voltage V2, but will approach the gray-scale voltage V 3 via the operation list =H ^ positive* ′, that is, the gray scale 25 5 . Μ元Μ 122 * If it is added or subtracted as data, _本; =, = This field is generally not described. To uncover the road, it should be easy to infer its implementation method. Here, class _AS to sample timing and conversion, as shown in Figure 2C. Gray scale voltages GL1 to GL3 11 2.Z1TW 24869twf.doc/n 201029447 is the grayscale voltage actually required to be achieved by the analog image signal AS, and the difference between the grayscale voltage actually sampled is called compensation. Value (indicating Δ V2). The compensating device 100 uses the difference 彳s number (indicating AVI) generated by the analog image signal 八3 in each of the first half weeks d to infer the corresponding compensation value, and then compensates the pixel sampling signal to make it close to the actual The grayscale value to be sent. The compensation values required for e f and gray scale change are different, depending on the signal ^ drive capability of the system. Therefore, the search unit 126 has a lookup table for storing the correspondence between the difference signal and the compensation value. As long as the combination of different t gray scale changes, such as gray scale 200 to gray scale 25 〇 or gray scale 252 to gray = 180, etc., the difference signal and the required compensation value can be measured in advance to be used in advance. In addition, since the analog video signal has a fixed driving capability in the same system, it is also possible to directly pass the difference value of the difference signal, and it is not necessary to establish a lookup table in advance. The second embodiment of the present invention is a block diagram of the image signal compensating device of the second embodiment of the present invention. The main difference between FIG. 3 and FIG. 2 is the oversampling unit 3iq. The oversampling training is performed by using the sampling clock of twice the frequency. effect. The oversampling unit 310 includes a phase locked dice side comrade and a multiplexer 318. The lock phase is called 316, the analog digital converter generates twice the frequency of the household frequency to take out the net ^ " According to the 'test time pulse REF2 will insert the broadcast ^ Tiger CK3 ' analog digital converter 312 mine according to the multiplied sampling signal CK3 into the digital conversion 3 § Into oversampling. In other words, the analogy (4) 2 is sampled twice during the parental conversion cycle. Therefore, 201029447^Z1TW 24869twf.doc/n takes the pixel sampling signal DS and the middle and rotates the pixel sampling signal ds and the intermediate in the interval: = data in the MS. Then, 昼 tf is removed from the intermediate sampling signal (e.g., read, MS2) via the multiplexer 318. Compensation unit 12. The internal structure and the operation principle thereof are the same as those in the first embodiment, and are not described here. The third embodiment is a method for compensating the image signal according to the third embodiment of the present invention: the king step S41 〇 sampling an analog image signal Then, in step S420, the first-pixel sampling signal, the inter-sampling sampling signal, and the second-sampling sampling signal are sequentially outputted, and the towel-sampling signal corresponds to the gradation of the gradation, followed by the step S43G. The compensation value is output according to the amount of change of the first-order pixel sampling signal and the 曰 sampling (four), and then the second-dimensional sampling signal is positively used (S440). In other words, in the above steps S42〇~S44〇, according to the middle

The voltage difference represented between the sampled signal and the pre-halogen sampled signal is used to derive the compensation value of the latter pixel sampled signal' and thereby correct each pixel sampled signal to be closer to the correct gray scale Voltage value. The rest of the operation details of the present embodiment are described in detail in the first and second embodiments described above, and those skilled in the art should be readily ascertained by the disclosure of the present invention, which is not described herein. In summary, the present invention utilizes the oversampling method to infer the amount of voltage change of the gray scale voltage in, for example, a half cycle, and accordingly corrects the value of the gray scale voltage to be closer to the correct gray scale value. The invention can be directly integrated into the connection interface of the display device, so that the display display surface is distorted. The fourth embodiment can be applied to different systems, and the image money compensation device in FIG. 1 and FIG. 3A can be directly integrated into the liquid crystal display. The surface display quality is as follows. Please refer to FIG. 5, and the controller 5 is according to the present invention. The liquid crystal display of the fourth embodiment. The liquid crystal display 500 includes a connector 102, an image signal compensating device 1, and image processing units 51A and 520. The image signal supplemental sugar (10) is coupled between the connector 102 and the image processing unit S51Q for compensating for the ratio of the received signal of the connector 1{)2, such as the money AS, and the output of the pixel sampling signal Ds. The liquid 51C is used to display the corresponding surface on the liquid crystal panel 52A according to the halogen sampling signal Ds. The number compensating unit 1GQ compensates the analog sampling signal by the analogy of the analog image = the picture signal and the intermediate sample signal in an oversampling manner, thereby compensating for the problem that the system side driving capability is not ambiguous. Regarding the signal of the signal compensating device 100, the above-mentioned first to third real-times are described in this section. ί 'Image processing unit 510 will include image scaling = human 111 circuit' so the image signal compensation unit 100 can be straightened == zoom, is directly set in the connector and image processing early Too · to compensate Analog signal. The image signal compensation list === does not limit the above-mentioned embodiment, and may be used as a preferred embodiment to disclose the above. However, it is not intended to limit the present invention. Those skilled in the art of illuminating the materials may make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the protection of the present invention is defined by the scope of the patent application. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram of an image signal compensating apparatus according to a first embodiment of the present invention.

Fig. 2A is a circuit diagram of an image signal compensating apparatus according to a first embodiment of the present invention. 2B is a graph of gray scale voltage according to a second embodiment of the present invention. Figure 2C is a graph of an analog image signal in accordance with a second embodiment of the present invention. Fig. 3 is a block diagram showing an image signal compensating apparatus according to a second embodiment of the present invention.

Fig. 4 is a flow chart showing a method of compensating an image signal according to a third embodiment of the present invention. Figure 5 is a liquid crystal display according to a fourth embodiment of the present invention. [Description of main component symbols] 100: Compensation device 102: Connector 11: Oversampling unit 112, 114, 312: Analog-to-digital converter 115, 315: Clock unit 15 201029447^1XW 24869twf.doc/n 116, 316 : phase-locked loop 117 : phase shifter 126 : search unit 120 : compensation unit 124 , 122 : arithmetic unit 318 : multiplexer 500 . liquid crystal display 510 : image processing unit 520 . liquid crystal panel AS : analog image signal DS : Alien sampling signal MS, MSI, MS2: intermediate sampling signal REF1, REF2: reference clock CK1: first clock signal CK2: second clock signal CK3: multiplied clock signal Φ DS1: first pixel sampling signal DS2: second pixel sampling signal DMS: difference signal VI~V3, GL1~GL3: gray scale voltage T: sampling period △VI: voltage difference represented by the difference signal ΔV2: compensation voltage represented by the compensation value S410 ~S440: Flowchart Step 16

Claims (1)

201029447.Z1TW 24869twf.doc/n VII. Patent application scope: L An image signal compensation device, including: - the first - poor for sampling ~ analog image signal and sequential sample signal 7: Γ - intermediate sampling signal and - According to the first 昼 取样 昼 昼 修正 修正 修正 = = ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― ― The signal and the -second clock signal, - the first it - the clock money, the second clock, the money section - the phase difference; out of the first digit converter 'sequentially according to the first clock signal! 1 sampling signal And the second pixel sampling signal; and the intermediate sampling 3-bit digital converter, according to the first, pulse (4) outputting the 3 - Λ ν _, the image signal compensation device described in claim 2 of the patent scope And a phase-locked loop coupled to the first analog-to-digital converter for edge-out: a 1-pulse signal; and a crying phase shifter coupled to the phase-locked loop and the second analog-bit When the conversion is used, the second clock signal is called. The image signal compensating apparatus of claim 2, wherein the phase difference is 18 degrees. The image signal compensating device of claim 1, wherein the oversampling unit comprises: a clock pulse unit that rotates a frequency doubling clock signal; The analog-to-digital converter 'sequentially outputs the first pixel sampling signal, the intermediate sampling signal, and the second pixel-sampling signal, and a multi-mode, coupled to the analogy according to the frequency-doubled clock signal And a digital converter for distinguishing the first pixel sampling signal, the second pixel sampling signal, and the intermediate sampling signal. The image signal compensating device of claim 1, wherein the compensating unit comprises: a first computing unit coupled to the oversampling unit, and sampling the money and the towel according to the first enthalpy a sampling unit for outputting a difference signal; a search unit that outputs the compensation value according to the difference signal; and a second operation unit coupled to the search unit and the oversampling unit, and correcting the The second pixel sampled signal. Φ 7. The video signal compensating apparatus according to claim 6, wherein the lookup table 7L includes a lookup table (10) for storing the correspondence between the difference signal and the compensation value. 8. The image signal compensating device as described in claim 1 of the patent application, wherein the oversampling unit receives the analog image signal via a connector. 9. The image signal compensating device of claim 8, wherein the connector comprises a video graphics array connector or a color difference interface 18 201029447" TW 24869twf.doc/n connector. 10. The image signal compensation pen set as described in claim 6 wherein the difference signal corresponds to the ink change of the analog image signal. 11. The image signal compensation sound as described in claim 6 I, wherein the first computing unit and the second computing unit are complementary methods for compensating image signals, including the following boat sampling-analog image signals; _· and sequentially outputting a first pixel a sampling signal, an intermediate sampling guarding a second halogen sampling signal; '° outputting a compensation value according to the first-slung ratcheting number and the sampling sample between the towels; and using the compensation value to correct the second halogen sampling signal. 13. The method as claimed in claim 12, wherein the first pixel sampling signal and the intermediate sampling signal are further included in the lookup table to obtain the four values of the liquid crystal display, including: And a receiver for receiving an analog image signal; the image signal compensation device is coupled to the connector=image mirror and sequentially generates a first pixel sample; the sample signal and the medium sample signal, and according to The first element is taken; and the change amount of the number is corrected by the second element sampling type image processing unit, and the image is lightly connected to the second book according to the second book. - Beijing sampling 仏唬 shows a face on a liquid crystal panel. The liquid crystal display device of claim 14, wherein the image signal compensating device is integrated in one of the image processing units. ^ 16. The liquid crystal display according to claim 14, wherein the image signal compensating device comprises: , = an oversampling unit, configured to sample the analog image signal and sequentially rotate the first pixel sampling signal, the intermediate sampling signal And the second pixel sampling signal; and the plug compensation unit is coupled to the oversampling unit, and outputs a compensation value according to the variation of the first book sample signal and the intermediate sample signal, 4 more sample records. 液晶. The liquid crystal display according to claim 16 of the patent scope, the oversampling unit comprises: , middle cargo, Ganmai unit, outputting a first clock signal and a second clock for ~ - the clock signal and the second clock signal have a phase difference of 7 out of the analog-to-digital converter, according to the first clock signal, a first-order pixel sampling signal and the second pixel sampling signal; The intermediate sampling is performed by the digital conversion, and the clock is rotated according to the second clock signal, such as the liquid crystal display of claim 17, wherein the squaring includes: The first 'between the digits and the brain, for the pulse signal; and the continuation of the private thief' touch the axis scale without the second analog digital conversion 20 201029447 Z1TW 24869twf.doc / n between the device for outputting the second time 19. The liquid crystal display according to claim 17, wherein the phase difference is 18 degrees. ', , 20. The liquid crystal display according to claim 16 of the patent application, 1 s over sampling The unit includes: ', % pulse unit, output - multiplication clock signal; the second ΪΐΪ ίί for 11 'the lion face clock (four), sequentially outputting the sampling signal intermediate sampling signal and the second 昼-昼 analog digital a converter for distinguishing the number. The said dicetin sampling signal and the intermediate sampling signal are the liquid crystal display according to item 16, wherein the book unit is lightly connected thereto. Sampling list & and according to the current -!= nickname The intermediate sampling signal round-difference signal is based on the difference signal to rotate the compensation value; and the element, and the Litian is early, coupled to the searching unit and the over-resolved 檨罝 to correct the second element Sampling signal: Find strict: as in the patent range, the liquid crystal display (5) corresponding to the ^ ^ - lookup table ' is used to store the difference signal and the compensation Ϊ the over-fan = connected: the liquid crystal _, where the connection The liquid crystal display of claim 23, wherein the connector comprises a video graphics array connector or a color difference interface connector. 21 20 1 029447" 1 TW 24869 tw. 25. The liquid crystal display of claim 21, wherein the difference signal corresponds to a voltage variation of the analog image signal. 26. The liquid crystal display of claim 21, wherein the first arithmetic unit and the second arithmetic unit are adders. m twenty two