WO2012162907A1 - 液晶显示器及其驱动方法 - Google Patents

液晶显示器及其驱动方法 Download PDF

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Publication number
WO2012162907A1
WO2012162907A1 PCT/CN2011/075474 CN2011075474W WO2012162907A1 WO 2012162907 A1 WO2012162907 A1 WO 2012162907A1 CN 2011075474 W CN2011075474 W CN 2011075474W WO 2012162907 A1 WO2012162907 A1 WO 2012162907A1
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WO
WIPO (PCT)
Prior art keywords
liquid crystal
crystal display
light source
determining unit
image signal
Prior art date
Application number
PCT/CN2011/075474
Other languages
English (en)
French (fr)
Inventor
郭东胜
Original Assignee
深圳市华星光电技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 深圳市华星光电技术有限公司 filed Critical 深圳市华星光电技术有限公司
Priority to DE112011105300.2T priority Critical patent/DE112011105300B4/de
Priority to US13/375,704 priority patent/US20120306938A1/en
Publication of WO2012162907A1 publication Critical patent/WO2012162907A1/zh

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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/3406—Control of illumination source
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0237—Switching ON and OFF the backlight within one frame
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/06—Adjustment of display parameters
    • G09G2320/0626—Adjustment of display parameters for control of overall brightness
    • G09G2320/0646—Modulation of illumination source brightness and image signal correlated to each other

Definitions

  • the present invention relates to a liquid crystal display and a method of driving the same.
  • liquid crystal displays have been officially replaced by cathode ray tubes, and have become mainstream display types.
  • Various electronic devices on the market such as mobile phones, personal digital assistants, digital cameras, computer screens or laptop screens, almost all use liquid crystal display screens as their display screens.
  • the current screen scanning frequency of liquid crystal displays has been reduced from the traditional 60 Hz (Herze, Hz), gradually developed to 120Hz and 240Hz products, their display effect is better than the traditional 60Hz liquid crystal display.
  • Higher screen scan frequency frame The liquid crystal display of rate indicates that the more images that can be displayed in the same time, the images in motion will be smoother, and the high-screen scanning frequency can improve the quality of dynamic images.
  • FIG. 1 is an image change diagram of a prior art liquid crystal display with a refresh rate of 60 Hz, 120 Hz, or 240 Hz when a screen with little change is displayed.
  • the refresh rate is 60 Hz, only one frame appears in 1/60 seconds; when the refresh frequency is 120 Hz, two frames appear within 1/60 seconds; when the refresh frequency is 240 Hz, four frames appear within 1/60 seconds. .
  • a tile is moved once between the first frame change and the second frame.
  • the refresh rate is 120 Hz
  • the same tile is moved only once, as shown in frames 1 to 3.
  • the tile does not change at the position of the second frame, but only moves at the third frame.
  • the refresh rate is 240 Hz, the same tile moves only once, as shown in the first frame change to the fifth frame. In fact, the position of the tile in the second frame to the fourth frame is unchanged, and only moves in the fifth frame.
  • FIG. 2 is an image change diagram when the refresh rate is 120 Hz and 240 Hz when the liquid crystal display displays another screen with little change.
  • the refresh frequency is 120 Hz
  • a tile is moved once between the first frame change and the second frame, and the same tile is displayed once again between the second frame change and the third frame.
  • the refresh rate is at 240 Hz
  • the same tile is moved only twice, as shown in the first frame change to the fifth frame.
  • the tile does not change in the positions of the 2nd frame and the 4th frame, and only moves in the 3rd frame and the 5th frame.
  • an object of the present invention is to provide a liquid crystal display and a driving method thereof, which can temporarily turn off the light source or not output the current frame image signal when determining that the current frame image signal is the same as the previous frame image signal, so as to reduce power consumption.
  • the invention discloses a liquid crystal display, comprising a liquid crystal display panel, a processing unit, a backlight module, a control unit and a determining unit, wherein the control unit is configured to periodically output a control signal, and the determining unit receives the image signal And the control signal, determining whether it is necessary to determine whether the current frame image signal is the same as the previous frame image signal according to the control signal, and if the determination is not needed, the determining unit controls the light source of the backlight module to be turned on, and if it is necessary to determine, When the frame image signals are different, the determining unit controls the light source of the backlight module to be turned on, and when the two frames of the image signals are the same, the light source of the backlight module is controlled to be turned off.
  • the liquid crystal display further includes a timing controller connected to the processing unit, wherein the timing controller receives the plurality of image signals generated by the processing unit and converts the image signals into data signals.
  • the liquid crystal display further includes a timing controller connected to the determining unit, wherein the determining unit transmits the received image signal of the plurality of frames to the timing controller, and the timing controller converts the image signal For data signals.
  • the liquid crystal display further includes a timing controller connected to the determining unit, wherein the determining unit outputs a current frame image signal to the timing controller while controlling the light source of the backlight module to be turned on, the control unit The image controller does not output any image signal to the timing controller while controlling the light source of the backlight module to be turned off, and the timing controller is configured to convert the image signal it receives into a data signal.
  • the control unit is a counting control unit for counting the number of frames of the image signal output by the processing unit.
  • the counting control unit outputs a control signal to the determining unit.
  • the determining unit receives the control signal, transmitting the current frame image signal to the timing controller, and outputting the light source turn-on signal to control the light source of the backlight module to be turned on; if the determining unit does not receive the control signal, Determining whether the current frame image signal is the same as the previous frame image signal. If the same, the determining unit does not output any image signal to the timing controller, and outputs the light source off signal to control the backlight of the backlight module to be turned off.
  • the determining unit transmits the current frame image signal to the timing controller, and outputs the light source turning-on signal to control the light source of the backlight module to be turned on.
  • the predetermined value is k(x/60)+1, wherein x represents a refresh frequency of the liquid crystal display, and k is a natural number.
  • the control unit is a timing control unit, configured to output a control signal to the determining unit every other predetermined time period after the processing unit outputs the mth frame image signal, where m is a positive integer. And if the determining unit receives the control signal, transmitting the current frame image signal to the timing controller, and outputting the light source turn-on signal to turn on the light source of the backlight module; if the determining unit does not receive the control signal, Determining whether the current frame image signal is the same as the previous frame image signal. If the same, the determining unit does not output any image signal to the timing controller, and outputs a light source off signal to turn off the light source of the backlight module. If different, the above The determining unit transmits the current frame image signal to the timing controller, and outputs the light source opening signal to turn on the light source of the backlight module.
  • the predetermined time period is x/60 frames, wherein x represents a refresh frequency of the liquid crystal display.
  • the refresh rate of the liquid crystal display is 120 Hz or 240 Hz.
  • the present invention further discloses a driving method of a liquid crystal display, comprising a liquid crystal display panel, a processing unit, a light source, a control unit and a determining unit.
  • the driving method of the liquid crystal display comprises the following steps: 1. Output of the processing unit An i-th frame image signal, the initial value of i is 1; 2.
  • the control unit counts the number of frames of the output image signal, and determines whether the number of frames is a predetermined value, and if it is a predetermined value, performs step 3; if not For the value, step 4 is performed; 3.
  • the determining unit controls the light source to be turned on, and then performs step 5; 4.
  • the liquid crystal display further includes a timing controller for converting the image signal into a data signal.
  • the processing unit outputs the ith frame image signal to The determining unit; in the third step, the determining unit controls the light source to be turned on and further outputs the received ith frame image signal to the timing controller; in the fourth step, if the same, the determining unit does not output any image signal.
  • the timing controller Up to the timing controller, and controlling the light source to be turned off; if different, the determining unit controls the light source to be turned on, and outputs the received ith frame image signal to the timing controller.
  • control unit is a counting control unit for counting the number of frames of the image signal output by the processing unit.
  • the predetermined value is k(x/60)+1, wherein x represents a refresh frequency of the liquid crystal display, and k is a natural number.
  • the refresh rate of the liquid crystal display is 120 Hz or 240 Hz.
  • the invention further discloses a driving method of a liquid crystal display, comprising a liquid crystal display panel, a processing unit, a light source, a control unit and a determining unit.
  • the driving method of the liquid crystal display comprises the following steps: 1. Output of the processing unit An i-th frame image signal, the initial value of i is 1; 2.
  • the control unit outputs a control signal to the determining unit every other predetermined time period from the output of the m-th frame image signal by the processing unit, where m is a positive integer; 2. If the determining unit receives the control signal, perform step 3; if the determining unit does not receive the control signal, perform step 4; 3.
  • the determining unit controls the light source to be turned on, and then perform step 5;
  • the liquid crystal display further includes a timing controller for converting the image signal into a data signal.
  • the determining unit controls the light source to be turned on while further Outputting the received ith frame image signal to the timing controller; in step 4, if the same, the determining unit does not output any image signal to the timing controller, and controls the light source to be turned off; if different, the above determination The unit controls the light source to be turned on, and outputs the ith frame image signal received by the unit to the timing controller.
  • the predetermined time period is x/60 frames, wherein x represents a refresh frequency of the liquid crystal display.
  • the refresh rate of the liquid crystal display is 120 Hz or 240 Hz.
  • the present invention provides a liquid crystal display and a driving method thereof, which use a determining unit to determine whether the current frame image signal is identical to the previous frame image signal. If it is determined that the current frame image signal is consistent with the previous frame image signal, the light source is temporarily turned off or the current frame image signal is not output to the timing controller, so the display panel does not display the image. Since the present invention is applied to a liquid crystal display having a high refresh rate, even when the screen is not changed, even if the output light is temporarily stopped, the human eye does not perceive a discontinuous image, so that while maintaining a certain image quality, Reduce power consumption to save power.
  • the present invention provides a liquid crystal display and a driving method thereof, which use a determining unit to determine whether the current frame image signal is identical to the previous frame image signal. If it is determined that the current frame image signal is consistent with the previous frame image signal, the light source is temporarily turned off or the current frame image signal is not output to the timing controller, so the display panel does not display the image. Since the present invention is applied to a liquid crystal display having a high refresh rate, even when the screen is not changed, even if the output light is temporarily stopped, the human eye does not perceive a discontinuous image, so that while maintaining a certain image quality, Reduce power consumption to save power.
  • FIG. 1 is an image change diagram of a prior art liquid crystal display with a refresh rate of 60 Hz, 120 Hz, or 240 Hz when a screen with little change is displayed.
  • FIG. 2 is an image change diagram when the refresh rate is 120 Hz and 240 Hz when the liquid crystal display displays another screen that does not change much.
  • FIG. 3 is a schematic view showing the circuit structure of the first embodiment of the liquid crystal display of the present invention.
  • FIG. 4 is a flow chart showing a driving method of the liquid crystal display of the present invention.
  • FIG. 5 is a schematic diagram showing a comparison between a screen represented by a video signal output by the processing unit and an image screen actually displayed by the liquid crystal display when the refresh rate of the liquid crystal display of the second embodiment is 120 Hz.
  • FIG. 6 is a schematic diagram showing a comparison between a screen represented by an image signal output by the processing unit and an image screen actually displayed by the liquid crystal display when the refresh rate of the liquid crystal display of the second embodiment is 240 Hz.
  • FIG. 7 is a schematic diagram showing a comparison between a screen represented by another image signal output by the processing unit and an image screen actually displayed by the liquid crystal display when the refresh rate of the liquid crystal display of the second embodiment is 240 Hz.
  • FIG. 3 is a schematic diagram showing the circuit structure of the first embodiment of the liquid crystal display device 100 of the present invention.
  • the liquid crystal display 100 includes a determining unit 101, a processing unit 102, a counting control unit 105, and a timing controller (timing).
  • a controller 104 a plurality of data drivers 106, a plurality of scan drivers 108, a backlight module 120, and a liquid crystal display panel 110.
  • the liquid crystal display panel 110 includes a plurality of pixel units 130.
  • the refresh rate of the liquid crystal display 100 is 120 Hz or 240 Hz.
  • the processing unit 102 can be a central processing unit of a personal computer or a notebook computer for outputting a plurality of image signals to the determining unit 101.
  • the count control unit 105 is for counting the number of frames of the video signal output by the processing unit 102. When the number of frames is a predetermined value, the counting control unit 105 outputs a first control signal to the determining unit 101; when the number of frames is not a predetermined value, the counting control unit 105 outputs a second control signal to the determining unit 101.
  • the determining unit 101 is configured to transmit the current frame image signal to the timing controller 104, and determine whether it is necessary to determine whether the current frame image signal is identical to the previous frame image signal according to the two control signals, and correspondingly output the light source control signal.
  • the light source control signal is a light source turn-on signal or a light source turn-off signal.
  • the backlight module 120 includes a light source driving circuit 122 and a plurality of light sources 124.
  • Light source 124 can be a light emitting diode or a cold cathode ray tube.
  • the light source driving circuit 122 controls the turning on or off of the light source 124 according to the light source turn-on signal or the turn-off signal.
  • the judging unit 101 transmits the current frame image signal to the timing controller 104 regardless of which of the above control signals is received.
  • the determining unit 101 when receiving the first control signal, the determining unit 101 outputs a light source turn-on signal to the light source driving circuit 122; when receiving the second control signal, determining whether the current frame image signal is the same as the previous frame image signal, if the same, The determining unit 101 outputs a light source off signal to the light source driving circuit 122. If not, the determining unit 101 outputs a light source turning signal to the light source driving circuit 122.
  • the timing controller 104 is configured to generate a frequency pulse signal to the scan driver 108, and also convert the image signal it receives into a data signal.
  • the scan driver 108 is configured to output a scan signal according to the frequency pulse signal, and the data driver 106 converts the data signal into gray voltages of different voltage levels.
  • the data driver 106 and the scan driver 108 are disposed on a flexible circuit board (not shown) (Chip On film (COF), or placed on a glass substrate (Chip of glass, COG), and then electrically connected through a flexible circuit board.
  • COF Chip On film
  • COG glass substrate
  • the scan driver 108 sequentially generates a plurality of scan signals to the liquid crystal display panel 110, so that the transistors of the pixel unit 130 of each row of the liquid crystal display panel 110 (not shown) ) Open sequentially. While the transistors of one row of pixel units 130 are turned on, the data driver 106 outputs a plurality of gray voltages to charge the liquid crystal capacitors (not shown) of the row of pixel units 130 to the level of the gray voltage to display different gray levels.
  • FIG. 4 is a flow chart of a driving method of the liquid crystal display 100 of the present invention.
  • the driver method consists of the following steps:
  • Step S1 The processing unit 102 outputs an ith frame image signal to the determining unit 101, and the initial value of i is 1.
  • Step S2 The count control unit 105 counts the number of frames output by the processing unit 102, and determines whether the number of frames is a predetermined value; if yes, step S3 is performed; if not, step S4 is performed.
  • Step S3 the counting control unit 105 outputs the first control signal to the determining unit 101, and the determining unit 101 directly outputs the received ith frame image signal to the timing controller 104, and outputs a light source turning signal to the light source driving circuit 122, and then Step S7 is performed.
  • the timing controller 104 After receiving the ith frame image signal, the timing controller 104 generates a frequency pulse signal to the scan driver 108, and converts the ith frame image signal into a plurality of data signals and outputs the data signal to the data driver 106.
  • the scan driver 108 sequentially outputs a plurality of scan signals to the liquid crystal display panel 110 according to the frequency pulse signals, so that the thin film transistors of the pixel units 130 of each row are sequentially turned on.
  • the data driver 106 outputs a plurality of gray voltages according to the plurality of data signals to charge the liquid crystal capacitors of the row of pixel units 130 to the level of the gray voltage to display different gray levels. degree.
  • the light source driving circuit 122 controls the light source 124 to be turned on.
  • Step S4 The counting control unit 105 outputs the second control signal to the determining unit 101, and the determining unit 101 determines whether the i-th frame and the i-th frame video signal are the same. If they are the same, step S5 is performed; if not, step S6 is performed.
  • step S5 the determining unit 101 directly outputs the ith frame image signal to the timing controller 104, and outputs a light source off signal to the light source driving circuit 122.
  • the light source driving circuit 122 controls the light source 124 to be turned off according to this, and then performs step S7.
  • step S6 the determining unit 101 directly outputs the ith frame image signal to the timing controller 104, and outputs a light source turn-on signal to the light source driving circuit 122.
  • the light source driving circuit 122 controls the light source 124 to be turned on according to this, and then performs step S7.
  • the timing controller 104 cooperates with the scan driver 108 and the data driver 106 to control the liquid crystal display panel 110 to display the ith frame picture.
  • the determining unit 101 of the liquid crystal display device 100 of the present invention outputs a light source off signal to the light source driving circuit 122 when receiving the second control signal and determining that the current frame image signal is the same as the previous frame image signal, and the light source is driven.
  • the circuit 122 thereby turns off the light source 124, thereby saving power consumption of the entire liquid crystal display 100.
  • the liquid crystal display 100 of the present invention cancels the display of some of the same frame images without the display quality of the image frame.
  • the liquid crystal display device of the second embodiment of the present invention is substantially the same as the liquid crystal display device 100 of the first embodiment, and the difference is that the determining unit 101 of the liquid crystal display device of the second embodiment further receives two control signals and two frames of images according to the second embodiment. Whether the signals are the same determines whether to output the current frame image signal to the timing controller 104. That is, when the second control signal is received and the current frame image signal is identical to the previous frame image signal, the determination unit 101 does not output any image signal to the timing controller 104, and outputs a light source off signal to the light source driving circuit 122. Otherwise, the determining unit 101 directly outputs the current frame image signal to the timing controller 104, and outputs a light source turn-on signal to the light source driving circuit 122.
  • the driving method of the liquid crystal display of the second embodiment is also substantially the same as the driving method of the liquid crystal display of the first embodiment, and the difference is that in step S5, the determining unit 101 does not output any image signal to the timing controller 104, and outputs one.
  • the light source off signal is sent to the light source driving circuit 122, and the light source driving circuit 122 controls the light source 124 to be turned off according to this, and then step S7 is performed.
  • the determining unit 101 of the liquid crystal display of the second embodiment does not output any image signal when receiving the second control signal and determining that the current frame image signal is the same as the previous frame image signal.
  • the timing controller 104 and thus the timing controller 104 and the data driver 106, does not operate, thereby further saving power consumption of the entire liquid crystal display.
  • FIG. 5 is a schematic diagram showing a comparison between a picture represented by the image signal outputted by the processing unit 102 and an image displayed by the liquid crystal display when the refresh rate of the liquid crystal display of the second embodiment is 120 Hz.
  • the screen A indicates the screen indicated by the video signal output by the processing unit 102
  • the screen B indicates the video screen actually displayed by the liquid crystal display.
  • Figure 5 shows the first frame, the second frame, and the third frame.
  • the driving method for displaying the above three frames is as follows:
  • the controller 104 cooperates with the scan driver 108 and the data driver 106 to control the display panel 110 device to display the first frame image signal, and the light source driving circuit 122 controls the light source 124 to be turned on. Therefore, the image frame actually displayed by the liquid crystal display is as shown in the first frame of FIG. 5 . .
  • the light source driving circuit 122 controls the light source 124 to be turned off according to this; therefore, the liquid crystal display does not actually display the second frame. Therefore, the video screen of the second frame is the black screen shown in FIG.
  • the determining unit 101 does not output any image signal to the timing controller 104 in the second frame, and outputs a light source off signal to the light source driving circuit 122 to control the light source 124 to be turned off. Therefore, the power consumption of the entire liquid crystal display can be saved.
  • the refresh frequency is 120 Hz
  • the first frame image signal and the second frame image signal are the same, even if the second frame is not displayed, only the first frame and In the third frame, the effect that the human eye actually sees the first frame and the third frame is also basically equivalent to the effect displayed by all three frames.
  • FIG. 6 is a schematic diagram showing a comparison between a picture represented by an image signal output by the processing unit and an image displayed by the liquid crystal display when the refresh rate of the liquid crystal display of the second embodiment is 240 Hz.
  • the screen C indicates the screen indicated by the video signal output by the processing unit 102
  • the screen D indicates the video screen actually displayed by the liquid crystal display.
  • Figure 6 shows the first, second, third, fourth, and fifth frames.
  • the driving method for displaying the above five frames is as follows:
  • Step S1 The processing unit 102 outputs an ith frame image signal to the determining unit 101, and the initial value of i is 1;
  • Step S2 the counting control unit 105 counts the number of frames output by the processing unit 102 to 1, It is a predetermined value;
  • Step S3 The counting control unit 105 outputs the first control signal to the determining unit 101, and the determining unit 101 directly outputs the received first frame image signal to the timing controller 104, and outputs a light source turning signal to the light source driving. Since the circuit 122 is displayed, the image screen actually displayed on the liquid crystal display is as shown in the first frame of FIG.
  • the light source driving circuit 122 controls the light source 124 to be turned off according to this; therefore, the liquid crystal display does not actually display the second frame. Therefore, the video screen of the second frame is the black screen shown in FIG. 6.
  • the method of displaying the 3rd frame and the 4th frame picture is similar to the method of displaying the 2nd frame picture, and will not be described in detail.
  • the method of displaying the fifth frame picture is similar to the method of displaying the first frame picture and will not be described in detail.
  • the judging unit does not output any image signal to the timing controller 104 in the second, third and fourth frames, and outputs a light source off signal to the light source driving circuit 122, and the control light source 124 is turned off. Therefore, the power consumption of the entire liquid crystal display can be saved.
  • the refresh frequency is 240 Hz
  • the image signals of the first, second, third, and fourth frames are the same, even if the second, third, and fourth frames are not displayed, only the display is displayed.
  • the effect that the human eye actually sees the first frame and the fifth frame is also basically equivalent to the effect displayed in all five frames.
  • FIG. 7 is a schematic diagram showing the comparison between the image represented by another image signal output by the processing unit 102 and the image displayed by the liquid crystal display when the refresh rate of the liquid crystal display of the second embodiment is 240 Hz.
  • the screen E indicates the screen indicated by the video signal output by the processing unit 102
  • the screen F indicates the video screen actually displayed by the liquid crystal display.
  • Figure 7 shows the first to fifth frames.
  • the driving method for displaying the above five frames is as follows:
  • Step S1 The processing unit 102 outputs an ith frame image signal to the determining unit 101, and the initial value of i is 1;
  • Step S2 the counting control unit 105 counts the number of frames output by the processing unit 102 to be 1, a predetermined value;
  • step S3 the counting control unit 105 outputs the first control signal to the determining unit 101, and the determining unit 101 directly outputs the received first frame image signal to the timing controller 104, and outputs a light source turning signal to the light source driving circuit. 122. Therefore, the video screen actually displayed on the liquid crystal display is as shown in the first frame of FIG.
  • the light source driving circuit 122 controls the light source 124 to be turned off according to this; therefore, the liquid crystal display does not actually display the second frame. Therefore, the video screen of the second frame is the black screen shown in FIG.
  • the judging unit 101 outputs the third frame image signal to the timing controller 104, and outputs a light source turn-on signal to the light source driving circuit 122.
  • the light source driving circuit 122 controls the light source 124 to be turned on according to this; therefore, the image displayed by the liquid crystal display is as shown in FIG. 7.
  • the second frame is shown.
  • the light source driving circuit 122 controls the light source 124 to be turned off according to this; therefore, the liquid crystal display does not actually display the fourth frame. Therefore, the video screen of the fourth frame is the black screen shown in FIG.
  • the method of displaying the fifth frame picture is similar to the method of displaying the first frame picture and will not be described in detail.
  • the judging unit 101 does not output any image signal to the timing controller 104 in the second and fourth frames, and outputs a light source off signal to the light source driving circuit 122 to control the light source 124 to be turned off. Therefore, the power consumption of the entire liquid crystal display can be saved.
  • the refresh frequency is 240 Hz
  • the image signals of the first and second frames are the same, the image signals of the third and fourth frames are the same, even if the second and fourth frames are not displayed. Only the first, third, and fifth frames are displayed, and the effect that the human eye actually sees the first, third, and fifth frames is basically equivalent to the effect displayed in five frames.
  • the liquid crystal display of the present invention and the driving method thereof are not limited to the first embodiment and the second embodiment, and have other modified embodiments.
  • the timing controller 104 of the first embodiment may not connect the above-mentioned judging unit 101, but The processing unit 102 is directly connected to receive the digital image signals output by the processing unit 102.
  • the counting control unit 105 of the first embodiment may also output only one control signal, that is, when the number of frames is a predetermined value, output a control signal to the determining unit 101; when the number of frames is not a predetermined value, the control signal is not output to the determining unit 101. . If the determining unit 101 receives the above control signal, the current frame image signal is transmitted to the timing controller 104, and the light source turn-on signal is output to the light source driving circuit 122; if the determining unit 101 does not receive the control signal, the current frame image is determined.
  • the determining unit 101 does not output any image signal to the timing controller 104, and outputs a light source off signal to the light source driving circuit 122. If not, the determining unit 101 will image the current frame. The signal is transmitted to the timing controller 104 and the light source turn-on signal is output to the light source driving circuit 122.
  • the counting control unit 105 of the second embodiment may also be another control unit, such as a timing control unit.
  • the timing control unit outputs a control signal to the determining unit every predetermined period of time after the processing unit 102 outputs the mth frame image signal.
  • m is a positive integer.
  • the determining unit 101 receives the above control signal, the current frame image signal is transmitted to the timing controller 104, and the light source turn-on signal is output to the light source driving circuit 122; if the determining unit 101 does not receive the control signal, the current frame image is determined. Whether the signal is the same as the image signal of the previous frame, if the same, the determining unit 101 does not output any image signal to the timing controller 104, and outputs a light source off signal to the light source driving circuit 122. If not, the determining unit 101 will image the current frame. The signal is transmitted to the timing controller 104, and a light source turn-on signal is output to the above-described light source driving circuit 122.

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Abstract

一种液晶显示器（100）及其驱动方法。液晶显示器（100）包含液晶显示面板（110）、处理单元（102）、背光模块（120）、控制单元（105）和判断单元（101）。处理单元（102）用来产生数帧影像信号。控制单元（105）用于周期性地输出控制信号。判断单元（101）接收影像信号和控制信号，并根据控制信号决定是否需要判断当前帧影像信号与前一帧影像信号是否相同。如果不需要判断，贝幌断单元（101）控制背光模块（120）的光源（124）开启。如果需要判断，则在两帧影像信号不同的情况下，判断单元（101）控制背光模块（120）的光源（124）开启，在两帧影像信号相同的情况下，控制背光模块（120）的光源（124）关闭。由于背光模块（120）在侦测到第i帧与第i-1帧影像信号相同的时候会关闭，所以液晶显示器（100）可以节省电力的消耗。

Description

液晶显示器及其驱动方法 技术领域
本发明涉及一种液晶显示器及其驱动方法。
 背景技术
近年来，由于液晶显示器轻薄短小的特性，已经使液晶显示器正式取代阴极射线管，而成为主流的显示器种类。目前市场上各种电子设备，如移动电话、个人数字助理、数字相机、计算机屏幕或笔记本电脑屏幕，几乎都采用液晶显示屏幕作为其显示屏幕。
为了更好的显示动态画面，目前的液晶显示器的画面扫瞄频率已经由传统的60赫兹(Herze, Hz)，逐渐开发到120Hz和240Hz的产品，它们的显示效果更优于传统60Hz的液晶显示器。越高画面扫瞄频率(frame rate)的液晶显示器表示同时间内能显示的画面越多时，运动中的影像会更流畅，可见高画面扫瞄频率可以提高动态影像的质量。
请参阅图1，图1是一种现有技术的液晶显示器在显示变动不大的画面时，刷新频率分别为60Hz、120Hz或是240Hz时的影像变化图。当刷新频率为60Hz时，1/60秒内只出现一个帧；当刷新频率为120Hz时，1/60秒内出现两个帧；当刷新频率为240Hz时，1/60秒内出现四个帧。但是在刷新频率为60Hz下，第1帧变化至第2帧之间显示有一图块移动了一次。当刷新频率为120Hz时，同样的图块也只移动了一次，如第1帧至第3帧所示。实际上，该图块在第2帧的位置不变，只有在第3帧才移动。当刷新频率为240Hz时，同样的图块也只移动了一次，如第1帧变化至第5帧所示。实际上，该图块在第2帧至第4帧的位置不变，只有在第5帧才移动。
请参阅图2，图2是上述液晶显示器在显示另一变动不大的画面时，刷新频率分别为120Hz和240Hz时的影像变化图。当刷新频率为120Hz时，第1帧变化至第2帧之间显示有一图块移动了一次，第2帧变化至第3帧之间显示同样的图块又移动了一次。相对地，当刷新频率处于240Hz时，同样的图块也只移动了两次，如第1帧变化至第5帧所示。实际上，该图块在第2帧和第4帧的位置不变，只有在第3帧和第5帧才移动。
由图1和图2可知，当影像变动不大时，即使使用较高刷新频率(例如120Hz、240Hz)的液晶显示器来显示影像，仍有部分相邻帧的画面实质上是不变的。然而，即使相邻两帧的画面不变，仍然需要一稳定的偏压电流对液晶电容充电，造成整个液晶显示器的功耗的变高。因此，如何更有效地降低液晶显示器的功率消耗是业界努力的目标。
 技术问题
因此本发明的目的是提供一种液晶显示器以及其驱动方法，会在判断当前帧影像信号与前一帧影像信号相同时，暂时关闭光源或是不输出当前帧影像信号，以降低功耗。
 技术解决方案
本发明揭露一种液晶显示器，其包含一液晶显示面板、一处理单元、一背光模块、一控制单元和一判断单元，上述控制单元用于周期性的输出控制信号，上述判断单元接收上述影像信号和控制信号，根据上述控制信号决定是否需要判断当前帧影像信号与前一帧影像信号是否相同，如果不需要判断，则上述判断单元控制上述背光模块的光源开启，如果需要判断，则在上述两帧影像信号不同的情况下，上述判断单元控制上述背光模块的光源开启，在上述两帧影像信号相同的情况下，控制上述背光模块的光源关闭。
根据本发明的一实施例，上述液晶显示器进一步包括一连接上述处理单元的时序控制器，上述时序控制器接收上述处理单元产生的数帧影像信号，并将上述影像信号转换为数据信号。
根据本发明的一实施例，上述液晶显示器进一步包括一连接上述判断单元的时序控制器，上述判断单元将其接收的数帧影像信号传输至上述时序控制器，上述时序控制器将上述影像信号转换为数据信号。
根据本发明的一实施例，上述液晶显示器进一步包括一连接上述判断单元的时序控制器，上述判断单元在控制上述背光模块的光源开启的同时输出当前帧影像信号至上述时序控制器，上述控制单元在控制上述背光模块的光源关闭的同时不输出任何影像信号至上述时序控制器，上述时序控制器用于将其接受的影像信号转换为数据信号。
根据本发明的一实施例，上述控制单元为计数控制单元，其用于计数上述处理单元输出的影像信号的帧数，当帧数是预定值时，上述计数控制单元输出一控制信号至判断单元，如果上述判断单元接收到上述控制信号，则将当前帧影像信号传送给上述时序控制器，并输出上述光源开启信号控制上述背光模块的光源开启；如果上述判断单元没接收到上述控制信号，则判断当前帧影像信号与前一帧影像信号是否相同，如果相同，则上述判断单元不输出任何影像信号至上述时序控制器，并输出上述光源关闭信号控制上述背光模块的光源关闭，如果不同，则上述判断单元将当前帧影像信号传送给上述时序控制器，并输出上述光源开启信号控制上述背光模块的光源开启。
根据本发明的一实施例，上述预定值为k(x/60)+1，其中x表示上述液晶显示器的刷新频率，k为自然数。
根据本发明的一实施例，上述控制单元为计时控制单元，其用于自上述处理单元输出第m帧影像信号起，每隔一预定时段就输出一控制信号至上述判断单元，m为正整数，如果上述判断单元接收到上述控制信号，则将当前帧影像信号传送给上述时序控制器，并输出上述光源开启信号以开启上述背光模块的光源；如果上述判断单元没接收到上述控制信号，则判断当前帧影像信号与前一帧影像信号是否相同，如果相同，则上述判断单元不输出任何影像信号至上述时序控制器，并输出光源关闭信号以关闭上述背光模块的光源，如果不同，则上述判断单元将当前帧影像信号传送给上述时序控制器，并输出上述光源开启信号以开启上述背光模块的光源。
根据本发明的一实施例，上述预定时段为x/60帧，其中x表示上述液晶显示器的刷新频率。
根据本发明的一实施例，所述液晶显示器的刷新频率为120Hz或者240Hz。
本发明另揭露一种液晶显示器的驱动方法，其包含一液晶显示面板、一处理单元、一光源、一控制单元和一判断单元，上述液晶显示器的驱动方法包括如下步骤：一、上述处理单元输出一第i帧影像信号，i的初始值为1；二、上述控制单元计数输出的影像信号的帧数，并判断帧数是否为预定值，如果是预定值，则执行步骤三；如果不是预定值，则执行步骤四；三、上述判断单元控制上述光源开启，然后执行步骤五；四、上述判断单元判断第i帧与第i-1帧影像信号是否相同；如果相同，则上述判断单元控制上述光源关闭，然后执行步骤五；如果不同，则上述判断单元控制上述光源开启，然后执行步骤五；五、令i=i+1，回到步骤一。
根据本发明的一实施例，上述液晶显示器进一步包括一用于将上述影像信号转换为数据信号的时序控制器，上述液晶显示器的驱动方法的步骤一中，上述处理单元输出第i帧影像信号至上述判断单元；步骤三中，上述判断单元控制上述光源开启的同时进一步将其接收的第i帧影像信号输出至上述时序控制器；步骤四中，如果相同，则上述判断单元不输出任何影像信号至上述时序控制器，并控制上述光源关闭；如果不同，则上述判断单元控制光源开启，并将其接收的第i帧影像信号输出至上述时序控制器。
根据本发明的一实施例，上述控制单元为一用于计数上述处理单元输出的影像信号的帧数的计数控制单元。
根据本发明的一实施例，上述预定值为k(x/60)+1，其中x表示上述液晶显示器的刷新频率，k为自然数。
根据本发明的一实施例，所述液晶显示器的刷新频率为120Hz或者240Hz。
本发明又揭露一种液晶显示器的驱动方法，其包含一液晶显示面板、一处理单元、一光源、一控制单元和一判断单元，上述液晶显示器的驱动方法包括如下步骤：一、上述处理单元输出一第i帧影像信号，i的初始值为1；二、上述控制单元自处理单元输出第m帧影像信号起，每隔一预定时段就输出一控制信号至上述判断单元，m为正整数；二、如果上述判断单元接收到上述控制信号，则执行步骤三；如果上述判断单元未接收到上述控制信号，则执行步骤四；三、上述判断单元控制上述光源开启，然后执行步骤五；四、上述判断单元判断第i帧与第i-1帧影像信号是否相同；如果相同，则上述判断单元控制上述光源关闭，然后执行步骤五；如果不同，则上述判断单元控制上述光源开启，然后执行步骤五；五、令i=i+1，回到步骤一。
根据本发明的一实施例，上述液晶显示器进一步包括一用于将上述影像信号转换为数据信号的时序控制器，上述液晶显示器的驱动方法的步骤三中，上述判断单元控制上述光源开启的同时进一步将其接收的第i帧影像信号输出至上述时序控制器；步骤四中，如果相同，则上述判断单元不输出任何影像信号至上述时序控制器，并控制上述光源关闭；如果不同，则上述判断单元控制光源开启，并将其接收的第i帧影像信号输出至上述时序控制器。
根据本发明的一实施例，上述预定时段为x/60帧，其中x表示上述液晶显示器的刷新频率。
根据本发明的一实施例，所述液晶显示器的刷新频率为120Hz或者240Hz。
相较于现有技术，本发明提供一种液晶显示器以及其驱动方法，会利用一判断单元判断当前帧影像信号与前一帧影像信号是否相同。倘若判断当前帧影像信号与前一帧影像信号是一致的，则暂时关闭光源或不输出当前帧影像信号至时序控制器，所以显示面板不显示影像。由于本发明是应用于高刷新频率的液晶显示器之中，所以在画面不变时，即使暂时停止输出光线，人眼仍然不会感知到不连续的画面，因此在维持一定的影像质量下，可以降低功耗以达到省电的目的。
 有益效果
相较于现有技术，本发明提供一种液晶显示器以及其驱动方法，会利用一判断单元判断当前帧影像信号与前一帧影像信号是否相同。倘若判断当前帧影像信号与前一帧影像信号是一致的，则暂时关闭光源或不输出当前帧影像信号至时序控制器，所以显示面板不显示影像。由于本发明是应用于高刷新频率的液晶显示器之中，所以在画面不变时，即使暂时停止输出光线，人眼仍然不会感知到不连续的画面，因此在维持一定的影像质量下，可以降低功耗以达到省电的目的。
附图说明
图1是一种现有技术的液晶显示器在显示变动不大的画面时，刷新频率分别为60Hz、120Hz或是240Hz时的影像变化图。
图2是上述液晶显示器在显示另一变动不大的画面时，刷新频率分别为120Hz和240Hz时的影像变化图。
图3是本发明液晶显示器第一实施例的电路结构示意图。
图4是本发明液晶显示器的驱动方法流程图。
图5为第二实施例的液晶显示器的刷新频率为120Hz时，处理单元输出的影像信号所表示的画面和液晶显示器实际显示的影像画面的对比示意图。
图6为第二实施例的液晶显示器的刷新频率为240Hz时，处理单元输出的一种影像信号所表示的画面和液晶显示器实际显示的影像画面的对比示意图。
图7为第二实施例的液晶显示器的刷新频率为240Hz时，处理单元输出的另一种影像信号所表示的画面和液晶显示器实际显示的影像画面的对比示意图。
 本发明的最佳实施方式
以下各实施例的说明是参考附加的图式，用以例示本发明可用以实施之特定实施例。本发明所提到的方向用语，例如「上」、「下」、「前」、「后」、「左」、「右」、「顶」、「底」、「水平」、「垂直」等，仅是参考附加图式的方向。因此，使用的方向用语是用以说明及理解本发明，而非用以限制本发明。
请参阅图3，图3是本发明液晶显示器100第一实施例的电路结构示意图。上述液晶显示器100包含一判断单元101、一处理单元102、一计数控制单元105、一时序控制器(timing controller)104、数个数据驱动器106、数个扫描驱动器108、一背光模块120以及一液晶显示面板110。液晶显示面板110包含数个像素单元(pixel)130。液晶显示器100的刷新频率为120Hz或240Hz。
处理单元102可以为个人计算机或是笔记本电脑的中央处理器，用来输出数帧影像信号至判断单元101。计数控制单元105用于计数处理单元102输出的影像信号的帧数。当帧数是预定值时，计数控制单元105输出一第一控制信号至判断单元101；当帧数不是预定值时，计数控制单元105输出一第二控制信号至判断单元101。本实施例中，上述预定值为k(x/60)+1，其中x表示刷新频率，k取自然数，即k=0,1,2,3……。例如x=120Hz时，预定值为1,3,5,7……；x=240Hz时，预定值为1,5,9,13……。在其他实施例中，预定值还可以根据需要设定为其他值。
判断单元101用于将其接收当前帧影像信号传送给时序控制器104，并根据上述两个控制信号决定是否需要判断当前帧影像信号与前一帧影像信号是否相同，并对应输出光源控制信号。上述光源控制信号为光源开启信号或光源关闭信号。背光模块120包含光源驱动电路122和数个光源124。光源124可以为发光二极管或是冷阴极射线管。上述光源驱动电路122根据上述光源开启信号或关闭信号控制光源124的开启或关闭。
判断单元101不管接收到上述哪个控制信号，都会将当前帧影像信号传送给时序控制器104。此外，判断单元101在接收到第一控制信号时，输出光源开启信号至光源驱动电路122；在接收到第二控制信号时，判断当前帧影像信号与前一帧影像信号是否相同，如果相同，判断单元101输出光源关闭信号至上述光源驱动电路122，如果不同，判断单元101输出光源开启信号至上述光源驱动电路122。
时序控制器104用于产生频率脉冲信号至扫描驱动器108，也会将其接收的影像信号转换成数据信号。扫描驱动器108用于根据频率脉冲信号输出扫描信号，数据驱动器106会将上述数据信号转换成不同电压准位的灰度电压。数据驱动器106以及扫描驱动器108设置于软性电路板(未图示)上(Chip on film，COF)，或是设置在玻璃基板(未图示)上(Chip of glass，COG)，然后再透过软性电路板电连接。
时序控制器104产生的频率信号脉冲传送至扫描驱动器108时，扫描驱动器108会依序产生多个扫描信号至液晶显示面板110，使得液晶显示面板110每一行的像素单元130的晶体管(图未示)依序开启。在一行像素单元130的晶体管开启的同时，数据驱动器106输出多个灰度电压使该行像素单元130的液晶电容(图未示)充电到灰度电压的准位，以显示不同的灰度。
请参阅图4，图4是本发明液晶显示器100的驱动方法流程图。该驱动方法包含下列步骤：
步骤S1：处理单元102输出一第i帧影像信号至判断单元101，i的初始值为1。
步骤S2：计数控制单元105计数处理单元102输出的帧数，并判断帧数是否为预定值；如果是，则执行步骤S3；如果不是，则执行步骤S4。
步骤S3；计数控制单元105输出所述第一控制信号至判断单元101，判断单元101直接输出接收的第i帧影像信号至时序控制器104，并输出一光源开启信号至光源驱动电路122，然后执行步骤S7。
时序控制器104接收上述第i帧影像信号后，产生一频率脉冲信号至扫描驱动器108，并将第i帧影像信号转换成多个数据信号输出给上述数据驱动器106。扫描驱动器108根据频率脉冲信号依序输出多个扫描信号至液晶显示面板110，使每一行的像素单元130的薄膜晶体管依序开启。在一行像素单元130的薄膜晶体管开启的同时，数据驱动器106根据上述多个数据信号输出多个灰度电压使该行像素单元130的液晶电容充电到灰度电压的准位，以显示不同的灰度。在显示第i帧画面的同时，光源驱动电路122控制光源124开启。
步骤S4：计数控制单元105输出所述第二控制信号至判断单元101，判断单元101判断第i帧与第i-1帧影像信号是否相同。如果相同，则执行步骤S5；如果不同，则执行步骤S6。
步骤S5，判断单元101直接输出第i帧影像信号至时序控制器104，并输出一光源关闭信号至光源驱动电路122，光源驱动电路122据此控制光源124关闭，然后执行步骤S7。
步骤S6，判断单元101直接输出第i帧影像信号至时序控制器104，并输出一光源开启信号至光源驱动电路122，光源驱动电路122据此控制光源124开启，然后执行步骤S7。
时序控制器104配合扫描驱动器108和数据驱动器106控制液晶显示面板110显示第i帧画面。
步骤S7，令i=i+1，执行步骤S1。
相较于现有技术，本发明液晶显示器100的判断单元101在接收到第二控制信号且判断当前帧影像信号与前一帧影像信号相同时，输出光源关闭信号至光源驱动电路122，光源驱动电路122据此关闭光源124，从而可节省整个液晶显示器100的功率消耗。另外，本发明液晶显示器100是在高刷新频率的情况下，取消对某些相同帧影像的显示，不会影像画面的显示品质。
本发明第二实施例的液晶显示器与第一实施例的液晶显示器100大致相同，其区别之处在于：第二实施例液晶显示器的判断单元101进一步根据其接收的两个控制信号及两帧影像信号是否相同决定是否输出当前帧影像信号至时序控制器104。即判断单元101在接收到第二控制信号且判断当前帧影像信号与前一帧影像信号相同时，不输出任何影像信号至上述时序控制器104，且输出光源关闭信号至上述光源驱动电路122。否则，判断单元101直接输出当前帧影像信号至时序控制器104，并输出光源开启信号至光源驱动电路122。
第二实施例的液晶显示器的驱动方法与第一实施例的液晶显示器的驱动方法也大致相同，其区别之处在于：步骤S5，判断单元101不输出任何影像信号至时序控制器104，输出一光源关闭信号至光源驱动电路122，光源驱动电路122据此控制光源124关闭，然后执行步骤S7。
相较于第一实施例的液晶显示器，第二实施例的液晶显示器的判断单元101在接收到第二控制信号且判断当前帧影像信号与前一帧影像信号相同时，不输出任何影像信号到时序控制器104，因此时序控制器104和数据驱动器106不工作，从而进一步节省整个液晶显示器的功率消耗。
请一并参阅图5，图5为第二实施例的液晶显示器的刷新频率为120Hz时，处理单元102输出的影像信号所表示的画面和液晶显示器实际显示的影像画面的对比示意图。画面A表示处理单元102输出的影像信号所表示的画面，画面B表示液晶显示器实际显示的影像画面。图5显示了第1帧、第2帧和第3帧画面。显示上述三帧画面的驱动方法如下：
显示第1帧画面：步骤S1：处理单元102输出一第i帧影像信号至判断单元101，i=1；步骤S2：计数控制单元105计数处理单元102输出的帧数为1，是预定值；步骤S3：计数控制单元105输出所述第一控制信号至判断单元101，判断单元101直接输出接收的第1帧影像信号至时序控制器104，并输出一光源开启信号至光源驱动电路122，时序控制器104配合扫描驱动器108和数据驱动器106控制显示面板110设备显示第1帧影像信号，且光源驱动电路122控制光源124开启，因此液晶显示器实际显示的影像画面如图5的第1帧所示。
显示第2帧画面：步骤S7：令i=i+1，重复执行步骤S1：处理单元102输出一第i帧影像信号至判断单元101，i=2；步骤S2：计数控制单元105计数处理单元102输出的帧数为2，不是预定值；步骤S4：计数控制单元105输出所述第二控制信号至判断单元101，判断单元101判断出第2帧与第1帧影像信号相同；步骤S5：判断单元101不输出任何影像信号至时序控制器104，输出一光源关闭信号至光源驱动电路122，光源驱动电路122据此控制光源124关闭；因此液晶显示器实际上是不显示第2帧画面的，故第2帧的影像画面为图5所示的黑画面。
显示第3帧画面：步骤406：令i=i+1，重复执行步骤S1：处理单元102输出一第i帧影像信号至判断单元101，i=3；步骤S2：计数控制单元105计数处理单元102输出的帧数为3，是预定值；步骤S3：计数控制单元105输出所述第一控制信号至判断单元101，判断单元101直接输出接收的第3帧影像信号至时序控制器104，并输出一光源开启信号至光源驱动电路122，因此液晶显示器实际显示的影像画面如图5的第3帧所示。
综上可知，判断单元101在第2帧时，不输出任何影像信号至时序控制器104，且输出一光源关闭信号至光源驱动电路122，控制光源124关闭。因此可节省整个液晶显示器的功率消耗。
此外，由于人眼感知影像的微小变动有极限，在刷新频率为高扫描频率120Hz时，如果第1帧影像信号和第2帧影像信号相同，即使没有显示第2帧，只显示第1帧和第3帧，人眼实际看到第1帧和第3帧的效果也基本等效于三帧都显示的效果。
请参阅图4和图6，图6为第二实施例的液晶显示器的刷新频率为240Hz时，处理单元输出的一种影像信号所表示的画面和液晶显示器实际显示的影像画面的对比示意图。画面C表示处理单元102输出的影像信号所表示的画面，画面D表示液晶显示器实际显示的影像画面。图6显示了第1、2、3、4、5帧画面。显示上述五帧画面的驱动方法如下：
显示第1帧画面：步骤S1：上述处理单元102输出一第i帧影像信号至判断单元101，i的初始值为1；步骤S2：计数控制单元105计数处理单元102输出的帧数为1，是预定值；步骤S3：计数控制单元105输出所述第一控制信号至判断单元101，判断单元101直接输出接收的第1帧影像信号至时序控制器104，并输出一光源开启信号至光源驱动电路122，因此液晶显示器实际显示的影像画面如图6的第1帧所示。
显示第2帧画面：步骤S7：令i=i+1，重复执行步骤S1：处理单元102输出一第i帧影像信号至判断单元101，i=2；步骤S2：计数控制单元105计数处理单元102输出的帧数为2，不是预定值；步骤S4：计数控制单元105输出所述第二控制信号至判断单元101，判断单元101判断出第2帧与第1帧影像信号相同；步骤S5：判断单元101不输出任何影像信号至时序控制器104，输出一光源关闭信号至光源驱动电路122，光源驱动电路122据此控制光源124关闭；因此液晶显示器实际上是不显示第2帧画面的，故第2帧的影像画面为图6所示的黑画面。
显示第3帧和第4帧画面的方法与显示第2帧画面的方法类似，不再详细阐述。
显示第5帧画面的方法与显示第1帧画面的方法类似，不再详细阐述。
综上可知，判断单元在第2、3和4帧时，不输出任何影像信号至时序控制器104，且输出一光源关闭信号至光源驱动电路122，控制光源124关闭。因此可节省整个液晶显示器的功率消耗。
此外，由于人眼感知影像的微小变动有极限，在刷新频率为高扫描频率240Hz时，如果第1、2、3、4帧影像信号相同，即使没有显示第2、3、4帧，只显示第1帧和第5帧，人眼实际看到第1帧和第5帧的效果也基本等效于五帧都显示的效果。
请参阅图4和图7，图7为第二实施例的液晶显示器的刷新频率为240Hz时，处理单元102输出的另一种影像信号所表示的画面和液晶显示器实际显示的影像画面的对比示意图。画面E表示处理单元102输出的影像信号所表示的画面，画面F表示液晶显示器实际显示的影像画面。图7显示了第1~5帧画面。显示上述五帧画面的驱动方法如下：
显示第1帧画面：步骤S1：处理单元102输出一第i帧影像信号至判断单元101，i的初始值为1；步骤S2：计数控制单元105计数处理单元102输出的帧数为1，是预定值；步骤S3：计数控制单元105输出所述第一控制信号至判断单元101，判断单元101直接输出接收的第1帧影像信号至时序控制器104，并输出一光源开启信号至光源驱动电路122，因此液晶显示器实际显示的影像画面如图7的第1帧所示。
显示第2帧画面：步骤S7：令i=i+1，重复执行步骤S1：处理单元102输出一第i帧影像信号至判断单元101，i=2；步骤S2：计数控制单元105计数处理单元102输出的帧数为2，不是预定值；步骤S4：计数控制单元105输出所述第二控制信号至判断单元101，判断单元101判断出第2帧与第1帧影像信号相同；步骤S5：判断单元101不输出任何影像信号至时序控制器104，输出一光源关闭信号至光源驱动电路122，光源驱动电路122据此控制光源124关闭；因此液晶显示器实际上是不显示第2帧画面的，故第2帧的影像画面为图7所示的黑画面。
显示第3帧画面：步骤S7：令i=i+1，重复执行步骤S1：处理单元102输出一第i帧影像信号至判断单元101，i=3；步骤S2：计数控制单元105计数处理单元102输出的帧数为3，不是预定值；步骤S4：计数控制单元105输出所述第二控制信号至判断单元101，判断单元101判断出第3帧与第2帧影像信号不相同；步骤S6：判断单元101输出第3帧影像信号至时序控制器104，并输出一光源开启信号至光源驱动电路122，光源驱动电路122据此控制光源124开启；因此液晶显示器实际显示的影像画面如图7的第2帧所示。
显示第4帧画面：步骤S7：令i=i+1，重复执行步骤S1：处理单元102输出一第i帧影像信号至判断单元101，i=4；步骤S2：计数控制单元105计数处理单元102输出的帧数为4，不是预定值；步骤S4：计数控制单元105输出所述第二控制信号至判断单元101，判断单元101判断出第4帧与第3帧影像信号相同；步骤S5：判断单元101不输出任何影像信号至时序控制器104，输出一光源关闭信号至光源驱动电路122，光源驱动电路122据此控制光源124关闭；因此液晶显示器实际上是不显示第4帧画面的，故第4帧的影像画面为图7所示的黑画面。
显示第5帧画面的方法与显示第1帧画面的方法类似，不再详细阐述。
综上可知，判断单元101在第2、4帧时，不输出任何影像信号至上述时序控制器104，且输出一光源关闭信号至光源驱动电路122，控制光源124关闭。因此可节省整个液晶显示器的功率消耗。
此外，由于人眼感知影像的微小变动有极限，在刷新频率为高扫描频率240Hz时，如果第1、2帧影像信号相同，第3、4帧影像信号相同，即使没有显示第2、4帧，只显示第1、3、5帧，人眼实际看到第1、3、5帧的效果也基本等效于五帧都显示的效果。
本发明液晶显示器及其驱动方法并不限于第一实施例和第二实施例所述，还具有其它变更实施例，例如：第一实施例的时序控制器104可不连接上述判断单元101，而是直接连接上述处理单元102，直接接收上述处理单元102输出的数帧影像信号。
第一实施例的计数控制单元105也可以只输出一种控制信号，即在帧数是预定值时，输出控制信号至判断单元101；帧数不是预定值时，不输出控制信号至判断单元101。如果判断单元101接收到上述控制信号，则将当前帧影像信号传送给时序控制器104，并输出光源开启信号至光源驱动电路122；如果判断单元101没接收到上述控制信号，则判断当前帧影像信号与前一帧影像信号是否相同，如果相同，则判断单元101不输出任何影像信号至时序控制器104，并输出光源关闭信号至光源驱动电路122，如果不同，则判断单元101将当前帧影像信号传送给时序控制器104，并输出光源开启信号至光源驱动电路122。
第二实施例的计数控制单元105亦可为其它控制单元，例如计时控制单元，上述计时控制单元自处理单元102输出第m帧影像信号起，每隔一预定时段就输出一控制信号至判断单元101，m为正整数。上述预定时段可为x/60帧，其中x表示刷新频率。例如x=120Hz时，预定时段为2帧；x=240Hz时，预定时段为4帧。
如果判断单元101接收到上述控制信号，则将当前帧影像信号传送给时序控制器104，并输出光源开启信号至光源驱动电路122；如果判断单元101没接收到上述控制信号，则判断当前帧影像信号与前一帧影像信号是否相同，如果相同，则判断单元101不输出任何影像信号至时序控制器104，并输出光源关闭信号至光源驱动电路122，如果不同，则判断单元101将当前帧影像信号传送给时序控制器104，并输出光源开启信号至上述光源驱动电路122。
综上所述，虽然本发明已以较佳实施例揭露如上，但该较佳实施例并非用以限制本发明，该领域的普通技术人员，在不脱离本发明的精神和范围内，均可作各种更动与润饰，因此本发明的保护范围以权利要求界定的范围为准。
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  1. 一种液晶显示器，其包含一液晶显示面板、一处理单元和一背光模块，上述处理单元用来产生数帧影像信号，其特征在于，所述液晶显示器进一步包含一控制单元和一判断单元，上述控制单元用于周期性的输出控制信号，上述判断单元接收上述影像信号和控制信号，根据上述控制信号决定是否需要判断当前帧影像信号与前一帧影像信号是否相同，如果不需要判断，则上述判断单元控制上述背光模块的光源开启，如果需要判断，则在上述两帧影像信号不同的情况下，上述判断单元控制上述背光模块的光源开启，在上述两帧影像信号相同的情况下，控制上述背光模块的光源关闭。
  2. 根据权利要求1所述的液晶显示器，其特征在于：上述液晶显示器进一步包括一连接上述处理单元的时序控制器，上述时序控制器接收上述处理单元产生的数帧影像信号，并将上述影像信号转换为数据信号。
  3. 根据权利要求1所述的液晶显示器，其特征在于：上述液晶显示器进一步包括一连接上述判断单元的时序控制器，上述判断单元将其接收的数帧影像信号传输至上述时序控制器，上述时序控制器将上述影像信号转换为数据信号。
  4. 根据权利要求1所述的液晶显示器，其特征在于：上述液晶显示器进一步包括一连接上述判断单元的时序控制器，上述判断单元在控制上述背光模块的光源开启的同时输出当前帧影像信号至上述时序控制器，上述控制单元在控制上述背光模块的光源关闭的同时不输出任何影像信号至上述时序控制器，上述时序控制器用于将其接受的影像信号转换为数据信号。
  5. 5. 根据权利要求4所述的液晶显示器，其特征在于：上述控制单元为计数控制单元，其用于计数上述处理单元输出的影像信号的帧数，当帧数是预定值时，上述计数控制单元输出一控制信号至判断单元，如果上述判断单元接收到上述控制信号，则将当前帧影像信号传送给上述时序控制器，并输出上述光源开启信号控制上述背光模块的光源开启；如果上述判断单元没接收到上述控制信号，则判断当前帧影像信号与前一帧影像信号是否相同，如果相同，则上述判断单元不输出任何影像信号至上述时序控制器，并输出上述光源关闭信号控制上述背光模块的光源关闭，如果不同，则上述判断单元将当前帧影像信号传送给上述时序控制器，并输出上述光源开启信号控制上述背光模块的光源开启。
  6. 根据权利要求5所述的液晶显示器，其特征在于：上述预定值为k(x/60)+1，其中x表示上述液晶显示器的刷新频率，k为自然数。
  7. 根据权利要求4所述的液晶显示器，其特征在于：上述控制单元为计时控制单元，其用于自上述处理单元输出第m帧影像信号起，每隔一预定时段就输出一控制信号至上述判断单元，m为正整数，如果上述判断单元接收到上述控制信号，则将当前帧影像信号传送给上述时序控制器，并输出上述光源开启信号以开启上述背光模块的光源；如果上述判断单元没接收到上述控制信号，则判断当前帧影像信号与前一帧影像信号是否相同，如果相同，则上述判断单元不输出任何影像信号至上述时序控制器，并输出光源关闭信号以关闭上述背光模块的光源，如果不同，则上述判断单元将当前帧影像信号传送给上述时序控制器，并输出上述光源开启信号以开启上述背光模块的光源。
  8. 根据权利要求7所述的液晶显示器，其特征在于：上述预定时段为x/60帧，其中x表示上述液晶显示器的刷新频率。
  9. 根据权利要求1所述的液晶显示器，其特征在于：所述液晶显示器的刷新频率为120Hz或者240Hz。
  10. 一种液晶显示器的驱动方法，其包含一液晶显示面板、一处理单元、一光源、一控制单元和一判断单元，上述液晶显示器的驱动方法包括如下步骤：
    一、上述处理单元输出一第i帧影像信号，i的初始值为1；
    二、上述控制单元计数输出的影像信号的帧数，并判断帧数是否为预定值，如果是预定值，则执行步骤三；如果不是预定值，则执行步骤四；
    三、上述判断单元控制上述光源开启，然后执行步骤五；
    四、上述判断单元判断第i帧与第i-1帧影像信号是否相同；如果相同，则上述判断单元控制上述光源关闭，然后执行步骤五；如果不同，则上述判断单元控制上述光源开启，然后执行步骤五；
    五、令i=i+1，回到步骤一。
  11. 根据权利要求10所述的液晶显示器的驱动方法，其特征在于：上述液晶显示器进一步包括一用于将上述影像信号转换为数据信号的时序控制器，上述液晶显示器的驱动方法的步骤一中，上述处理单元输出第i帧影像信号至上述判断单元；步骤三中，上述判断单元控制上述光源开启的同时进一步将其接收的第i帧影像信号输出至上述时序控制器；步骤四中，如果相同，则上述判断单元不输出任何影像信号至上述时序控制器，并控制上述光源关闭；如果不同，则上述判断单元控制光源开启，并将其接收的第i帧影像信号输出至上述时序控制器。
  12. 根据权利要求10所述的液晶显示器的驱动方法，其特征在于：上述控制单元为一用于计数上述处理单元输出的影像信号的帧数的计数控制单元。
  13. 根据权利要求12所述的液晶显示器的驱动方法，其特征在于：上述预定值为k(x/60)+1，其中x表示上述液晶显示器的刷新频率，k为自然数。
  14. 根据权利要求10所述的液晶显示器的驱动方法，其特征在于：所述液晶显示器的刷新频率为120Hz或者240Hz。
  15. 一种液晶显示器的驱动方法，其包含一液晶显示面板、一处理单元、一光源、一控制单元和一判断单元，上述液晶显示器的驱动方法包括如下步骤：
    一、上述处理单元输出一第i帧影像信号，i的初始值为1；
    二、上述控制单元自处理单元输出第m帧影像信号起，每隔一预定时段就输出一控制信号至上述判断单元，m为正整数；
    二、如果上述判断单元接收到上述控制信号，则执行步骤三；如果上述判断单元未接收到上述控制信号，则执行步骤四；
    三、上述判断单元控制上述光源开启，然后执行步骤五；
    四、上述判断单元判断第i帧与第i-1帧影像信号是否相同；如果相同，则上述判断单元控制上述光源关闭，然后执行步骤五；如果不同，则上述判断单元控制上述光源开启，然后执行步骤五；
    五、令i=i+1，回到步骤一。
  16. 根据权利要求15所述的液晶显示器的驱动方法，其特征在于：上述液晶显示器进一步包括一用于将上述影像信号转换为数据信号的时序控制器，上述液晶显示器的驱动方法的步骤三中，上述判断单元控制上述光源开启的同时进一步将其接收的第i帧影像信号输出至上述时序控制器；步骤四中，如果相同，则上述判断单元不输出任何影像信号至上述时序控制器，并控制上述光源关闭；如果不同，则上述判断单元控制光源开启，并将其接收的第i帧影像信号输出至上述时序控制器。
  17. 根据权利要求15所述的液晶显示器的驱动方法，其特征在于：上述预定时段为x/60帧，其中x表示上述液晶显示器的刷新频率。
  18. 根据权利要求15所述的液晶显示器的驱动方法，其特征在于：所述液晶显示器的刷新频率为120Hz或者240Hz。
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