This application claims priority of Taiwanese Patent Application No. 110117350, filed on May 13, 2021.
The disclosure relates to display driving techniques, and more particularly to a backlight driving method and a backlight driving module for a scan-type display.
In a liquid crystal display, light emitted by a backlight module passes through a liquid crystal layer of a liquid crystal panel by a variable amount, and is filtered by a color filter of the liquid crystal panel, so as to produce color images. However, the liquid crystal layer has a long response time, and if all light emitting diodes (LEDs) of the backlight module emit light continuously, motion blur could occur when the liquid crystal display shows moving images.
Therefore, an object of the disclosure is to provide a backlight driving method and a backlight driving module for a scan-type display. The backlight driving method and the backlight driving module can alleviate motion blur.
According to an aspect of the disclosure, the backlight driving method is to be implemented by a backlight driving module of a scan-type display, and is adapted to drive a backlight module of the scan-type display. The backlight module includes a plurality of backlight sources. The backlight driving method includes steps of: (A) generating an original synchronization control signal and a serial input signal; the original synchronization control signal being related to refreshing of image frames on the scan-type display; the serial input signal containing an image stream and a plurality of predetermined delay values; (B) generating a plurality of internal synchronization control signals based on the original synchronization control signal and the predetermined delay values, such that a time delay of each of the internal synchronization control signals with respect to the original synchronization control signal is dependent on a respective one of the predetermined delay values; and (C) generating a plurality of backlight driving outputs based on the image stream and the internal synchronization control signals and outputting the backlight driving outputs respectively to the backlight sources, such that the backlight sources emit light in an order dependent on the predetermined delay values, and brightness of the backlight module is dependent on the image stream.
According to another aspect of the disclosure, the backlight driving module is adapted to be installed in a scan-type display to drive a backlight module of the scan-type display. The backlight module includes a plurality of backlight sources. The backlight driving module includes a plurality of backlight drivers that are adapted to be respectively coupled to the backlight sources. Each of the backlight drivers receives an original synchronization control signal and a serial input signal. The original synchronization control signal is related to refreshing of image frames on the scan-type display. The serial input signal contains an image stream and a plurality of predetermined delay values. Each of the backlight drivers generates an internal synchronization control signal based on the original synchronization control signal and a respective one of the predetermined delay values, such that a time delay of the internal synchronization control signal with respect to the original synchronization control signal is dependent on the respective one of the predetermined delay values. Each of the backlight drivers further generates a backlight driving output based on the image stream and the internal synchronization control signal and outputs the backlight driving output to the backlight source coupled to the backlight driver, such that the backlight sources emit light in an order dependent on the predetermined delay values, and brightness of the backlight module is dependent on the image stream.
Other features and advantages of the disclosure will become apparent in the following detailed description of the embodiment with reference to the accompanying drawings, of which:
Referring to
The backlight module 11 includes a plurality of backlight sources (e.g., three backlight sources 111-113 in this embodiment) that are arranged in parallel with one another. Each of the backlight sources 111-113 includes a plurality of switches (not shown), and a light emitting diode (LED) array (not shown) that includes a plurality of LEDs. The configuration of each of the backlight sources 11 is known to those skilled in the art, and other details thereof are omitted herein for the sake of brevity.
The backlight driving module 12 of this embodiment includes a controller 21 and a plurality of backlight drivers (e.g., three backlight drivers 121-123 in this embodiment). It should be noted that each of the backlight drivers 121-123 is fabricated as a single integrated circuit in this embodiment. In addition, while the controller 120 is included in the backlight driving module 12 in this embodiment, it may be independent of the backlight driving module 12 in other embodiments.
The controller 21 is configured to generate a serial input signal (SDI) and an original synchronization control signal (EVsync). The serial input signal (SDI) contains a plurality of predetermined delay values (three predetermined delay values in this embodiment) and an image stream. A total number of the predetermined delay values is equal to a total number of the backlight sources 111-113. All of the predetermined delay values may be the same, or at least two of the predetermined delay values may be different from each other. The image stream is generated by a graphics processing unit (GPU) (not shown) of the controller 120, and contains multiple pieces of image data that respectively correspond to multiple image frames (images of multiple frames of the image stream) to be shown by the scan-type display. Each piece of image data includes a plurality of data segments (three data segments in this embodiment). Each image frame includes a plurality of frame segments (three frame segments in this embodiment) that respectively correspond to the data segments of the corresponding piece of image data. The original synchronization control signal (EVsync) is related to refreshing of image frames on the scan-type display (i.e., an act of the scan-type display switching from displaying a current image frame to displaying a next image frame). In this embodiment, light transmittance of the liquid crystal panel 2 varies according to the image stream, and light emitted by the backlight module 11 is modulated by the liquid crystal panel 2 to produce the image frames related to the image stream.
Each of the backlight drivers 121-123 is coupled to the controller 120 to receive the serial input data (SDI) and the original synchronization control signal (EVsync), and is adapted to be further coupled to a respective one of the backlight sources 111-113. Each of the backlight drivers 121-123 generates an internal synchronization control signal (IVsync1/IVsync2/IVsync3) based on the original synchronization control signal (EVsync) and a respective one of the predetermined delay values, such that a time delay of the internal synchronization control signal (IVsync1/IVsync2/IVsync3) with respect to the original synchronization control signal (EVsync) is dependent on the respective one of the predetermined delay values. Each of the backlight drivers 121-123 further generates a backlight driving output (Dr1/Dr2/Dr3) based on the image stream and the internal synchronization control signal (IVsync1/IVsync2/IVsync3) and outputs the backlight driving output (Dr1/Dr2/Dr3) to the backlight source 111/112/113 coupled to the backlight driver 121/122/123, such that the backlight sources 111-113 emit light in an order dependent on the predetermined delay values, and brightness of the backlight module 11 is dependent on the image stream.
For example, the backlight driver 121 is coupled to the backlight source 111, delays the original synchronization control signal (EVsync) by a delay time dependent on a first one of the predetermined delay values so as to generate the internal synchronization control signal (IVsync1), and generates the backlight driving output (Dr1) based on the internal synchronization control signal (IVsync1) and a first one of the data segments of any piece of image data of the image stream. The backlight driver 122 is coupled to the backlight source 112, delays the original synchronization control signal (EVsync) by a delay time dependent on a second one of the predetermined delay values so as to generate the internal synchronization control signal (IVsync2), and generates the backlight driving output (Dr2) based on the internal synchronization control signal (IVsync2) and a second one of the data segments of any piece of image data of the image stream. The backlight driver 123 is coupled to the backlight source 113, delays the original synchronization control signal (EVsync) by a delay time dependent on a third one of the predetermined delay values so as to generate the internal synchronization control signal (IVsync3), and generates the backlight driving output (Dr3) based on the internal synchronization control signal (IVsync3) and a third one of the data segments of any piece of image data of the image stream.
It should be noted that each of the backlight driving outputs (Dr1-Dr3) includes a plurality of switching signals for respectively switching the switches of the corresponding backlight source 111/112/113 between conduction and non-conduction, and a plurality of driving signals for adjusting brightness of the LED array of the corresponding backlight source 111/112/113. The composition of each of the backlight driving outputs (Dr1-Dr3) is known to those skilled in the art, and other details thereof are omitted herein for the sake of brevity. In addition, the controller 120 outputs the serial input signal (SDI) and the original synchronization control signal (EVsync) to each of the backlight drivers 121-123 in this embodiment, but the disclosure is not limited thereto. For example, in another embodiment, the controller 120 outputs the serial input signal (SDI) and the original synchronization control signal (EVsync) only to the backlight driver 121; then the backlight driver 121 outputs the serial input signal (SDI) and the original synchronization control signal (EVsync) to the backlight driver 122; and finally the backlight driver 122 outputs the serial input signal (SDI) and the original synchronization control signal (EVsync) to the backlight driver 123. In yet another embodiment, the controller 120 outputs the serial input signal (SDI) to each of the backlight drivers 121-123, and outputs the original synchronization control signal (EVsync) only to the backlight driver 121; then the backlight driver 121 outputs the original synchronization control signal (EVsync) to the backlight driver 122; and finally the backlight driver 122 outputs the original synchronization control signal (EVsync) to the backlight driver 123. In still another embodiment, the controller 120 outputs the original synchronization control signal (EVsync) to each of the backlight drivers 121-123, and outputs the serial input signal (SDI) only to the backlight driver 121; then the backlight driver 121 outputs the serial input signal (SDI) to the backlight driver 122; and finally the backlight driver 122 outputs the serial input signal (SDI) to the backlight driver 123.
In this embodiment, as shown in
In this embodiment, each of the backlight driver 121-123 generates the corresponding backlight driving output (Dr1/Dr2/Dr3) in such a way that the corresponding backlight source 111/112/113 starts to emit light in a line scan manner (i.e., the LED array of the corresponding backlight source 111/112/113 emitting light row by row without overlapping one another in time) for a predetermined time period upon appearance of each pulse of the corresponding internal synchronization control signal (IVsync1/IVsync2/IVsync3).
Referring to
In step 31, the controller 120 generates the original synchronization control signal (EVsync) and the serial input signal (SDI).
In step 32, the controller 21 outputs the original synchronization control signal (EVsync) and the serial input signal (SDI) to each of the backlight drivers 121-123.
In step 33, each of the backlight drivers 121-123 generates the corresponding internal synchronization control signal (IVsync1/IVsync2/IVsync3) based on the original synchronization control signal (EVsync) and the corresponding predetermined delay value.
In step 34, each of the backlight drivers 121-123 generates the corresponding backlight driving output (Dr1/Dr2/Dr3) based on the image stream and the corresponding internal synchronization control signal (IVsync1/IVsync2/IVsync3) and outputs the corresponding backlight driving output (Dr1/Dr2/Dr3) to the corresponding backlight source 111/112/113, so as to drive the corresponding backlight source 111/112/113 to emit light.
In view of the above, in this embodiment, by virtue of the backlight driving module 12 performing the backlight driving method, the backlight sources 111-113 emit light in an order that is dependent on the predetermined values, instead of all emitting light continuously. Therefore, motion blur can be alleviated and display quality can be enhanced when the scan-type display shows moving images.
In the description above, for the purposes of explanation, numerous specific details have been set forth in order to provide a thorough understanding of the embodiment. It will be apparent, however, to one skilled in the art, that one or more other embodiments may be practiced without some of these specific details. It should also be appreciated that reference throughout this specification to “one embodiment,” “an embodiment,” an embodiment with an indication of an ordinal number and so forth means that a particular feature, structure, or characteristic may be included in the practice of the disclosure. It should be further appreciated that in the description, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of various inventive aspects.
While the disclosure has been described in connection with what is considered the exemplary embodiment, it is understood that the disclosure is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
Number | Date | Country | Kind |
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110117350 | May 2021 | TW | national |
Number | Name | Date | Kind |
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6243067 | Noguchi | Jun 2001 | B1 |
11132960 | Wu | Sep 2021 | B1 |
20080094344 | Kuroki | Apr 2008 | A1 |
20220366862 | Chen | Nov 2022 | A1 |
20220366863 | Chen | Nov 2022 | A1 |
Number | Date | Country | |
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20220366860 A1 | Nov 2022 | US |