Backlight module, backlight control method thereof and liquid crystal display device with adjustable backlight

Abstract

The embodiment of the present application provides a backlight module, a backlight control method of the backlight module and a liquid crystal display device with adjustable backlight, wherein the backlight control method of the backlight module comprises the following steps: obtaining real-time gray scale information transmitted by an external mainboard; comparing the real-time gray scale information with a preset gray scale threshold; adjusting color temperatures of a plurality of color temperature adjustable lamp beads in the backlight module to a target color temperature mode through a driving circuit of the backlight module according to a comparison result; and the target color temperature mode is a low color temperature mode or a standard color temperature mode. The embodiment of the present application is suitable for backlight adjustment in different picture gray scale states, can effectively correct picture white balance, optimize overall display effect and improve viewing experience.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a backlight module, a backlight control method for a backlight module, and a liquid crystal display device with adjustable backlight. Background Technology

[0002] Currently, LCD monitors generally use backlight modules with fixed color temperature to provide the light source. The amount of light passing through is controlled by adjusting the voltage of the liquid crystal layer, and different grayscale images are displayed in conjunction with polarizers.

[0003] When displaying low grayscale images, the phase retardation of the liquid crystal layer is small, and its ability to modulate the polarization direction of light is weak. At this time, the influence of the polarizer on the transmitted spectrum is dominant. Existing fixed color temperature backlight modules cannot adapt to this characteristic, resulting in more blue light passing through at low grayscale levels, causing the overall image to appear bluish and distorting the white balance at low grayscale levels. As the grayscale increases, the modulation capability of the liquid crystal layer strengthens, and the image color gradually returns to normal. This abrupt color change from low grayscale to mid-to-high grayscale levels causes uneven color transitions across the entire grayscale range, reducing display quality and affecting the user's viewing experience. Summary of the Invention

[0004] Therefore, in order to overcome at least some of the defects and deficiencies in the prior art, embodiments of the present invention provide a backlight module, a backlight control method for a backlight module, and a backlight-adjustable liquid crystal display device.

[0005] Specifically, in one aspect, embodiments of the present invention provide a backlight control method for a backlight module, comprising: acquiring real-time grayscale information transmitted from an external motherboard; comparing the real-time grayscale information with a preset grayscale threshold; and, based on the comparison result, adjusting the color temperature of multiple color-temperature adjustable LED beads in the backlight module to a target color temperature mode by controlling the driving circuit of the backlight module; wherein the target color temperature mode is a low color temperature mode or a standard color temperature mode.

[0006] In some embodiments, adjusting the color temperature of multiple color-temperature adjustable LED beads in the backlight module to a target color temperature mode by controlling the driving circuit of the backlight module according to the comparison result includes: when the real-time grayscale information is less than or equal to the grayscale threshold, controlling the driving circuit to switch the multiple color-temperature adjustable LED beads to a low color temperature mode; and when the real-time grayscale information is greater than the grayscale threshold, controlling the driving circuit to switch the multiple color-temperature adjustable LED beads to a standard color temperature mode.

[0007] In some embodiments, when the real-time grayscale information is less than or equal to the grayscale threshold, controlling the driving circuit to switch the plurality of color-temperature adjustable LED beads to a low color temperature mode specifically includes: matching the acquired real-time grayscale information with a plurality of pre-stored grayscale values ​​to determine the corresponding driving current value, wherein the plurality of grayscale values ​​are all less than or equal to the grayscale threshold; and controlling the driving circuit to output the corresponding driving current to the plurality of color-temperature adjustable LED beads according to the driving current value.

[0008] In some embodiments, the backlight module forms multiple backlight control areas corresponding to multiple display sub-areas of the liquid crystal display panel, and each backlight control area includes at least one of the color temperature adjustable LED beads; the step of acquiring real-time grayscale information transmitted from the external motherboard specifically includes: acquiring real-time grayscale information corresponding to each display sub-area; the step of adjusting the color temperature of the color temperature adjustable LED beads in the backlight module to the target color temperature mode according to the comparison result specifically includes: adjusting the color temperature of the color temperature adjustable LED beads in the corresponding backlight control area according to the real-time grayscale information of each display sub-area.

[0009] In some embodiments, the grayscale threshold is 10%-20% of the full-scale grayscale of the liquid crystal display panel.

[0010] In some embodiments, the grayscale threshold is 16% of the full-scale grayscale of the liquid crystal display panel.

[0011] On the other hand, embodiments of the present invention also provide a backlight module for executing the backlight control method of the backlight module as described above. The backlight module includes: a circuit board; a plurality of color-temperature adjustable LED beads disposed on and electrically connected to the circuit board; a driving circuit disposed on and electrically connected to the circuit board, wherein the plurality of color-temperature adjustable LED beads are respectively electrically connected to the driving circuit; and a main control chip disposed on and electrically connected to the circuit board, wherein the main control chip is electrically connected to the driving circuit, and the main control chip is used to acquire grayscale information from an external motherboard and control the current of the driving circuit according to the grayscale information to adjust the color temperature of the color-temperature adjustable LED beads; wherein the main control chip has a preset grayscale threshold.

[0012] In some embodiments, a plurality of color temperature adjustable LED beads are spaced apart on the circuit board, and the plurality of color temperature adjustable LED beads are arranged in a matrix.

[0013] In some embodiments, the backlight module forms multiple backlight control areas corresponding to multiple display sub-areas of the liquid crystal display panel, and each backlight control area includes at least one of the color temperature adjustable LED beads; the output terminal of the driving circuit is independently electrically connected to the color temperature adjustable LED beads in each backlight control area.

[0014] In another aspect, embodiments of the present invention also provide a backlight-adjustable liquid crystal display device, comprising: a liquid crystal display panel and a backlight module as described above, wherein the backlight module is connected to one side of the liquid crystal display panel.

[0015] As can be seen from the above, the embodiments of the present invention can achieve one or more of the following beneficial effects: by acquiring real-time grayscale information transmitted from an external motherboard, comparing the real-time grayscale information with a preset grayscale threshold, and adjusting the color temperature of multiple color-temperature adjustable LED beads in the backlight module to the target color temperature mode by controlling the driving circuit of the backlight module according to the comparison result. This method can dynamically adjust the color temperature of the backlight according to different grayscale levels. At low grayscale levels, the LED beads are switched to a low color temperature mode, which can effectively compensate for the influence of the polarizer on the transmitted spectrum at low grayscale levels, reduce blue light transmission, and improve the problems of blue tint and white balance distortion in low grayscale images. At medium and high grayscale levels, the LED beads are switched to a standard color temperature mode to ensure the normal display effect of the image. This avoids abrupt color changes from low grayscale to medium and high grayscale levels, making the color transition across the entire grayscale range smoother, improving display quality, and enhancing the user's viewing experience. Attached Figure Description

[0016] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the module connection of the backlight module provided in an embodiment of the present invention.

[0018] Figure 2 This is a full grayscale color point curve diagram for liquid crystal display devices using fixed color temperature backlight in the prior art.

[0019] Figure 3 This is a full grayscale color point curve diagram of a backlight-adjustable liquid crystal display device provided in an embodiment of the present invention.

[0020] Figure 4 This is a schematic flowchart of a backlight control method for a backlight module provided in an embodiment of the present invention.

[0021] Figure 5 for Figure 4 A flowchart of step S30.

[0022] Figure 6 for Figure 5 A flowchart of step S31.

[0023] Figure 7 This is a comparison chart of the backlight spectrum and polarizer transmittance of existing technologies.

[0024] Figure 8 This is a comparison diagram of the low grayscale backlight spectrum and the transmittance of the polarizer in an embodiment of the present invention.

[0025] [Explanation of Labels in the Attached Image] 10: Backlight module; 100: Circuit board; 200: Color temperature adjustable LED beads; 300: Driver circuit; 400: Main control chip. Detailed Implementation

[0026] To make the above-mentioned objectives, features, and advantages of the present invention more apparent and understandable, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] It should also be noted that the division of multiple embodiments in this invention is only for the convenience of description and should not constitute a special limitation. Features in various embodiments can be combined and referenced in each other without contradiction.

[0029] See Figure 1 This invention provides a backlight module 10 and a backlight-adjustable liquid crystal display device. The backlight-adjustable liquid crystal display device includes, for example, a liquid crystal display panel and the backlight module 10. The backlight module 10 is connected and disposed on one side of the liquid crystal display panel, and is used to provide a backlight source for the liquid crystal display panel. The liquid crystal display device can be, for example, an electronic device employing liquid crystal display technology such as a liquid crystal monitor or a liquid crystal television.

[0030] The backlight module 10 includes, for example, a circuit board 100, multiple color-temperature adjustable LED beads 200, a driving circuit 300, and a main control chip 400. The main control chip 400 is electrically connected to the driving circuit 300, and the driving circuit 300 is electrically connected to the multiple color-temperature adjustable LED beads 200. The multiple color-temperature adjustable LED beads 200, the driving circuit 300, and the main control chip 400 are respectively disposed on the circuit board 100 and electrically connected to the circuit board 100.

[0031] The circuit board 100 may be, for example, a printed circuit board (PCB) used to carry the electronic components of the backlight module 10 and to realize the electrical connection and signal transmission between the components. In other embodiments, the circuit board 100 may also be a flexible printed circuit board to adapt to the installation requirements of curved display devices; the specific type of circuit board is not limited here.

[0032] The main control chip 400 can be, for example, a microcontroller unit (MCU), whose signal input terminal is electrically connected to the display signal output terminal of the external motherboard, and whose control output terminal is electrically connected to the input terminal of the drive circuit 300. The main control chip 400 has a preset grayscale threshold in its internal non-volatile memory, used to acquire real-time grayscale information corresponding to the current display screen transmitted from the external motherboard, compare this grayscale information with the preset threshold, and generate a corresponding color temperature adjustment command to be sent to the drive circuit 300. In other embodiments, the main control chip 400 can also be other chips with logic operation and control functions; the specific chip type is not limited here.

[0033] The input terminal of the driver circuit 300 is electrically connected to the control output terminal of the main control chip 400, and the multiple output terminals are electrically connected to multiple color-temperature adjustable LED beads 200 respectively. The driver circuit 300 is used to receive color-temperature adjustment commands sent by the main control chip 400 and adjust the magnitude of the forward current output to each color-temperature adjustable LED bead 200 according to the commands. The driver circuit 300 can be an LED constant current driver circuit or a dedicated LED driver chip with integrated multi-channel constant current output. The specific circuit structure of the driver circuit 300 is not limited here.

[0034] Multiple color-temperature adjustable LED beads 200 can be, for example, dual-color-temperature LED beads. Color temperature adjustment can be achieved by adjusting the current ratio of different color-temperature light-emitting units. These multiple color-temperature adjustable LED beads 200 are positioned facing the light-incident surface of the liquid crystal display panel. In other embodiments, the color-temperature adjustable LED beads 200 can also employ other LED bead structures capable of color temperature adjustment; the specific structure of the LED beads is not limited here. The color-temperature adjustable LED beads 200 can be adjusted to a target color temperature mode, which includes a low color temperature mode and a standard color temperature mode. In the low color temperature mode, the color-temperature adjustable LED beads 200 output light primarily consisting of long-wavelength warm light, reducing the output proportion of short-wavelength blue light, resulting in an overall warmer light tone. In the standard color temperature mode, the color-temperature adjustable LED beads 200 output conventional standard white light, conforming to the conventional backlight output standards of liquid crystal display devices.

[0035] See Figure 2 , Figure 2This is a full grayscale color point curve diagram of a liquid crystal display device using a fixed color temperature backlight in the prior art. Figure 2 It is known that in existing technologies, because the backlight module maintains a fixed color temperature, its full grayscale color point curve has obvious defects: in the low grayscale range of 0-40, the x and y coordinates of the color point change significantly, causing the color point to shift, resulting in a bluish tint and white balance distortion in low grayscale images; furthermore, the transition of color points from low grayscale to mid-to-high grayscale is not smooth, exhibiting color jump phenomena. See [link / reference] Figure 3 , Figure 3 The full grayscale color point curve diagram of the backlight-adjustable liquid crystal display device provided in the embodiments of the present invention is derived from... Figure 3 It can be seen that the full grayscale color point curve of the LCD panel remains basically stable throughout the entire grayscale range, with small fluctuations in the x and y values ​​of the color point coordinates. The color point shift problem in the low grayscale range is effectively improved, the color transition from low grayscale to mid-to-high grayscale is natural, and the white balance consistency across the entire grayscale range is significantly improved. Among these improvements, Figure 2 , Figure 3 The horizontal axis represents the grayscale value of the LCD display panel, and the vertical axis represents the color point value.

[0036] Therefore, through the coordinated operation of the above-mentioned components, the embodiments of the present invention can improve the low grayscale display defects caused by fixed color temperature backlight, make the low grayscale color point curve smoother, significantly reduce the color jump from low grayscale to medium-high grayscale, make the image quality performance of the display smoother across the entire grayscale range, improve the overall display effect of the liquid crystal display, and enhance the user experience.

[0037] This invention embodiment sets multiple color-temperature adjustable LED beads 200 and a driving circuit 300 on a circuit board 100, electrically connecting a main control chip 400 to the driving circuit 300, and the driving circuit 300 to the multiple color-temperature adjustable LED beads 200. The main control chip 400 has a preset grayscale threshold and acquires real-time grayscale information of the display screen transmitted from the external motherboard, thus providing a stable and reliable basis for subsequent dynamic adjustment of the backlight color temperature. In this embodiment, the main control chip 400 compares the acquired real-time grayscale information with the preset grayscale threshold, generates a matching color temperature adjustment command based on the comparison result, and realizes backlight color temperature adjustment, ensuring that the backlight output matches the actual grayscale state of the display screen. After receiving the color temperature adjustment command from the main control chip 400, the driving circuit 300 adjusts the current output to the color-temperature adjustable LED beads 200, switching the color-temperature adjustable LED beads 200 to the corresponding target color temperature mode. In the low color temperature mode, the color-temperature adjustable LED beads 200... To output long-wavelength warm light, the proportion of short-wavelength blue light output is significantly reduced, resulting in an overall warmer light tone. This effectively compensates for the high blue light transmittance of the polarizer in low grayscale conditions, correcting the defects of bluish tint and uneven color point curves in low grayscale images. In standard color temperature mode, the 200 adjustable LED beads have a balanced ratio of warm and cool light, outputting standard white light with a neutral and natural tone, conforming to the standard backlight output of LCD devices. This meets the normal spectral control requirements of the liquid crystal layer in medium and high grayscale conditions, ensuring true color reproduction of the image.

[0038] Specifically, multiple color temperature adjustable LED beads 200 are distributed at intervals on the circuit board 100, and the multiple color temperature adjustable LED beads 200 are arranged in a matrix, so that the light intensity of the backlight module 10 is more evenly distributed on the entire light-emitting surface. The uniform light output can ensure that the backlight intensity received by each area of ​​the LCD panel is consistent, thereby improving the brightness uniformity and color consistency of the entire display screen and avoiding the problems of local overly bright or dark areas and uneven colors.

[0039] Furthermore, the backlight module 10 forms multiple backlight control areas corresponding to multiple display sub-areas of the liquid crystal display panel, and each backlight control area includes at least one color temperature adjustable LED bead 200; the output terminal of the driving circuit 300 is independently electrically connected to the color temperature adjustable LED bead 200 in each backlight control area, so that the color temperature of each area can be independently adjusted.

[0040] This invention, through setting backlight control areas corresponding to multiple display sub-areas of the liquid crystal display panel, utilizes a driving circuit to regulate the color temperature adjustable LEDs within each backlight control area. This allows for adaptation of the corresponding backlight color temperature to the grayscale state of different display sub-areas. Different display sub-areas within the same image can be in low grayscale or medium-high grayscale states respectively. Low grayscale areas switch to low color temperature mode, while medium-high grayscale areas switch to standard color temperature mode. By performing zoned matching and adjustment of the backlight color temperature for different display sub-areas, spectral deviations caused by grayscale differences in each area can be accurately compensated, the white balance of each area of ​​the entire image can be corrected, and the overall uniformity and display effect of the displayed image can be improved.

[0041] This invention also provides a backlight control method for a backlight module 10, which can be applied, for example, to the backlight module 10 described above. Specifically, the backlight control method for the backlight module 10 provided in this embodiment is executed by the main control chip 400 in the backlight module 10.

[0042] See Figure 4 The backlight control method for the backlight module 10 provided in this embodiment of the invention may include, for example, the following steps: S10: Obtain real-time grayscale information transmitted from the external motherboard; S20: Compare the real-time grayscale information with the preset grayscale threshold; S30: Based on the comparison results, the color temperature of multiple color temperature adjustable LED beads in the backlight module 10 is adjusted to the target color temperature mode by controlling the driving circuit of the backlight module 10; the target color temperature mode is a low color temperature mode or a standard color temperature mode.

[0043] When the backlight module 10 starts working with the display device, it can obtain real-time grayscale information transmitted from the external motherboard through the main control chip 400 of the backlight module 10, for example. This real-time grayscale information corresponds to the grayscale of the image currently displayed on the LCD panel. The specific grayscale information parsing method can be adjusted according to the display signal protocol, which is not limited here.

[0044] The main control chip 400 has a preset grayscale threshold. It compares the acquired real-time grayscale information with the preset grayscale threshold and generates a corresponding color temperature adjustment command based on the comparison result. This enables precise triggering of the color temperature adjustment action, so that the backlight color temperature can match the actual grayscale state of the display screen, ensuring the rationality and adaptability of the color temperature adjustment.

[0045] The main control chip 400 sends a color temperature adjustment command to the drive circuit 300. The drive circuit 300 receives the corresponding color temperature adjustment command and adjusts the color temperature of the color temperature adjustable LED bead 200 to the corresponding target color temperature mode, thereby realizing dynamic and controllable adjustment of the backlight color temperature and adapting it to the display characteristics under different gray levels.

[0046] This invention acquires real-time grayscale information transmitted from an external motherboard, compares this information with a preset grayscale threshold, and adjusts the color temperature of multiple adjustable LED beads 200 in the backlight module 10 to the target color temperature mode by controlling the driving circuit 300 of the backlight module 10 based on the comparison result. This method dynamically adjusts the backlight color temperature according to different grayscale levels. At low grayscale levels, the adjustable LED beads 200 are switched to a low color temperature mode, effectively compensating for the influence of the polarizer on the transmitted spectrum at low grayscale levels, reducing blue light transmission, and improving the problems of blue tint and white balance distortion in low grayscale images. At medium to high grayscale levels, the adjustable LED beads 200 are switched to a standard color temperature mode to ensure normal display performance. This avoids abrupt color changes from low to medium to high grayscale levels, resulting in smoother color transitions across the entire grayscale range, improving display quality and enhancing the user's viewing experience.

[0047] See Figure 5 In step S30, based on the comparison results, the color temperature of the adjustable LED beads in the backlight module 10 is adjusted to the target color temperature mode by controlling the driving circuit of the backlight module 10. This specifically includes the following steps: S31: When the real-time grayscale information is less than or equal to the grayscale threshold, control the driving circuit to switch the multiple color temperature adjustable LED beads to low color temperature mode; S32: When the real-time grayscale information is greater than the grayscale threshold, control the driving circuit to switch the plurality of color temperature adjustable LED beads to the standard color temperature mode.

[0048] In low color temperature mode, the adjustable LED 200 primarily outputs long-wavelength warm light, reducing the proportion of short-wavelength blue light output. The overall light tone is warm, effectively compensating for the high blue light transmittance of the polarizer at low grayscale levels and correcting the defects of bluish tint and white balance distortion. In standard color temperature mode, the adjustable LED 200 maintains a balanced ratio of warm and cool light, outputting standard white light with a neutral and natural tone, conforming to the standard backlight output of LCD devices. This matches the normal spectral control requirements of the liquid crystal layer at medium and high grayscale levels, ensuring accurate color reproduction. By matching the grayscale threshold and color temperature mode settings, the backlight color temperature and display grayscale can be precisely adapted, improving the unevenness of the low grayscale color point curve, significantly reducing color jumps from low to medium-high grayscale levels, and further enhancing the display quality and viewing experience of LCD devices.

[0049] See Figure 6 Step S31 specifically includes the following steps: S311: Match the acquired real-time grayscale information with multiple pre-stored grayscale values ​​to determine the corresponding drive current value, wherein multiple grayscale values ​​are all less than or equal to the grayscale threshold. S312: Based on the driving current value, control the driving circuit to output the corresponding driving current to the plurality of color temperature adjustable lamp beads.

[0050] Since the low grayscale range is the main area where the image appears bluish, and the amount of blue light transmitted varies at different low grayscale levels, fine-tuning of color temperature is needed within the low grayscale range. The main control chip 400 pre-stores multiple grayscale values ​​and corresponding drive current values, all of which are less than or equal to the grayscale threshold, providing parameter basis for fine-tuning color temperature adjustment in the low grayscale range. Further, the main control chip 400 matches the real-time acquired grayscale information with the pre-stored grayscale values ​​and determines the drive current parameter adapted to the current grayscale. Subsequently, the drive circuit 300 outputs a corresponding drive current to the color-temperature adjustable LED bead 200 according to the matched drive current value, enabling precise adjustment of the LED bead's color temperature according to the current grayscale. This embodiment, through the corresponding matching adjustment of grayscale and drive current, continuously adapts the backlight color temperature in the low grayscale range to grayscale changes, achieving fine-tuning of the backlight color temperature in the low grayscale range. This optimizes the smoothness of the color point curve in the low grayscale range, improves the white balance uniformity and color transition effect of the low grayscale image, and thus makes the image quality performance of the display smoother across the entire grayscale range, improving the overall display effect of the LCD and enhancing the user experience.

[0051] Preferably, the backlight module 10 forms multiple backlight control areas corresponding to multiple display sub-areas of the liquid crystal display panel, and each backlight control area includes at least one of the color temperature adjustable lamp beads. The acquisition of real-time grayscale information transmitted from the external motherboard specifically includes: acquiring real-time grayscale information corresponding to each display sub-area; The step of adjusting the color temperature of the adjustable LED beads in the backlight module 10 to the target color temperature mode based on the comparison results specifically includes: adjusting the color temperature of the adjustable LED beads in the corresponding backlight control area according to the real-time grayscale information of each display sub-area.

[0052] Preferably, the backlight module 10 forms multiple backlight control areas corresponding to multiple display sub-areas of the liquid crystal display panel, and each backlight control area includes at least one color temperature adjustable LED bead 200.

[0053] The acquisition of real-time grayscale information transmitted from the external motherboard specifically includes: the main control chip 400 acquiring the real-time grayscale information corresponding to each display sub-area on the LCD panel. The adjustment of the color temperature of the adjustable LED beads 200 in the backlight module 10 to the target color temperature mode based on the comparison results specifically includes: the main control chip 400 comparing the real-time grayscale information of each display sub-area with a preset grayscale threshold, and adjusting the color temperature of the adjustable LED beads 200 in the corresponding backlight control area to the target color temperature mode through the driving circuit 300 based on the comparison results of each display sub-area.

[0054] This embodiment acquires grayscale information by partitioning and adjusts the backlight color temperature independently for each partition. It can adapt the corresponding backlight color temperature to the grayscale state of different display sub-regions. Different display sub-regions in the same image can be in low grayscale or medium-high grayscale state respectively. The low grayscale display sub-region corresponds to the low color temperature mode, and the medium-high grayscale display sub-region corresponds to the standard color temperature mode. By performing partitioned matching and adjustment of the backlight color temperature of different display sub-regions, it can accurately compensate for the spectral deviation caused by grayscale differences in each region, correct the white balance of each region of the whole image, and improve the overall uniformity and display effect of the display image.

[0055] Specifically, liquid crystal display panels commonly use a full-scale grayscale of 256 levels. The grayscale threshold is 10% to 20% of the full-scale grayscale of the liquid crystal display panel. For example, 10%, 12%, 14%, 16%, 18%, or 20% of the full-scale grayscale can be selected. Through experiments and observations, it has been found that the optical characteristics of liquid crystal display panels change within the 10% to 20% range of the full-scale grayscale: below this threshold, the liquid crystal layer has a weaker ability to control the light spectrum, and the image is easily affected by the light transmission characteristics of the polarizer, which can easily lead to a higher amount of blue light transmission and an overall bluish tint to the image; above this threshold, the liquid crystal layer can normally control the spectrum, the image is less affected by the light transmission characteristics of the polarizer, and the amount of blue light transmission remains within a reasonable range.

[0056] The above phenomenon is related to the backlight spectrum and the light transmission characteristics of the polarizer. See [link to relevant documentation]. Figure 7 . Figure 7The blue curve represents the transmittance of the polarizer, while the red curve represents the output spectrum of a fixed color temperature backlight module in existing technology. The polarizer exhibits a relatively high transmittance peak in the short-wavelength blue light range of 380-430nm, indicating stronger transmittance in the blue light region. Meanwhile, the fixed color temperature backlight spectrum has a high energy peak in the blue light band. At low grayscale levels, the liquid crystal layer's ability to control light is weak, and the polarizer's transmittance characteristics dominate the final output spectrum. The final output spectrum is determined by the superposition of the backlight spectrum and the polarizer's transmittance characteristics. The blue light band combines high backlight energy with high polarizer transmittance; the combination results in excessive blue light transmission at low grayscale levels, ultimately manifesting as an overall bluish tint in the image.

[0057] See Figure 8 In this embodiment of the invention, the energy distribution of the backlight spectrum is adjusted by switching to a low color temperature mode at a low grayscale. Figure 8 The blue curve in the middle still represents the orthogonal transmittance characteristics of the polarizer in the liquid crystal display panel, and... Figure 7 Consistent with the inherent optical properties of the panel; the red curve represents the backlight spectrum under low grayscale and low color temperature mode, and is consistent with... Figure 7 Compared to conventional backlight spectra, the energy peak of its short-wavelength blue light is reduced, while the output proportion of long-wavelength warm light (500-700nm) is significantly increased. After the adjusted backlight spectrum is superimposed with the polarizer transmittance, the total transmittance in the blue light band is reduced, and the output proportion of long-wavelength warm light is correspondingly increased. This compensates for the high transmittance of the polarizer in the blue light range, resulting in a more balanced spectrum ultimately transmitted through the LCD panel, thus achieving white balance correction for low-grayscale images.

[0058] Based on this optical characteristic change law of liquid crystal display panel, the grayscale threshold range set in this embodiment can reasonably divide the low grayscale and medium-high grayscale regions, providing a reliable judgment basis for subsequent color temperature mode switching.

[0059] Preferably, the grayscale threshold is 16% of the full-scale grayscale of the liquid crystal display panel. Further experimental verification confirmed that 16% grayscale is a superior color temperature mode switching point. Below 16% grayscale, the adjustable color temperature LED 200 is switched to a low color temperature mode to compensate for the high blue light transmittance of the polarizer at low grayscale levels, correcting the defects of bluish tint and white balance distortion. Above 16% grayscale, the adjustable color temperature LED 200 is switched to a standard color temperature mode, conforming to the conventional backlight output standard of liquid crystal display devices and meeting the color reproduction requirements of normal images. By using this preferred threshold to complete grayscale state recognition and backlight mode switching, the backlight adjustment requirements under different display states can be accurately matched, effectively improving the color transition effect of the full grayscale image and further enhancing the overall image display effect of the liquid crystal display device.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A backlight control method for a backlight module, characterized in that, include: Obtain real-time grayscale information transmitted from the external motherboard; The real-time grayscale information is compared with a preset grayscale threshold. Based on the comparison results, the color temperature of multiple adjustable LED beads in the backlight module is adjusted to the target color temperature mode by controlling the driving circuit of the backlight module; the target color temperature mode is either a low color temperature mode or a standard color temperature mode.

2. The backlight control method for a backlight module as described in claim 1, characterized in that, The step of adjusting the color temperature of multiple adjustable LED beads in the backlight module to the target color temperature mode by controlling the driving circuit of the backlight module according to the comparison results includes: When the real-time grayscale information is less than or equal to the grayscale threshold, the driving circuit is controlled to switch the multiple color temperature adjustable LED beads to a low color temperature mode. When the real-time grayscale information is greater than the grayscale threshold, the driving circuit is controlled to switch the plurality of color temperature adjustable LED beads to the standard color temperature mode.

3. The backlight control method for a backlight module as described in claim 2, characterized in that, When the real-time grayscale information is less than or equal to the grayscale threshold, controlling the driving circuit to switch the plurality of color-temperature adjustable LED beads to a low color temperature mode specifically includes: The acquired real-time grayscale information is matched with multiple pre-stored grayscale values ​​to determine the corresponding driving current value, wherein multiple grayscale values ​​are all less than or equal to the grayscale threshold. Based on the driving current value, the driving circuit is controlled to output a corresponding driving current to a plurality of the color temperature adjustable LED beads.

4. The backlight control method for a backlight module as described in claim 1, characterized in that, The backlight module forms multiple backlight control areas corresponding to multiple display sub-areas of the liquid crystal display panel, and each backlight control area contains at least one of the color temperature adjustable lamp beads. The acquisition of real-time grayscale information transmitted from the external motherboard specifically includes: acquiring real-time grayscale information corresponding to each display sub-area; The step of adjusting the color temperature of the adjustable LED beads in the backlight module to the target color temperature mode based on the comparison results specifically includes: adjusting the color temperature of the adjustable LED beads in the corresponding backlight control area according to the real-time grayscale information of each display sub-area.

5. The backlight control method for a backlight module as described in claim 2, characterized in that, The grayscale threshold is 10%-20% of the full-scale grayscale of the liquid crystal display panel.

6. The backlight control method for a backlight module as described in claim 2, characterized in that, The grayscale threshold is 16% of the full-scale grayscale of the liquid crystal display panel.

7. A backlight module, characterized in that, A method for performing a backlight control of a backlight module as described in any one of claims 1-6, wherein the backlight module comprises: Circuit board; Multiple color temperature adjustable LED beads are mounted on the circuit board and electrically connected to the circuit board; A driving circuit is disposed on the circuit board and electrically connected to the circuit board, and a plurality of color temperature adjustable LED beads are respectively electrically connected to the driving circuit; The main control chip is electrically connected to the circuit board and is electrically connected to the drive circuit. The main control chip is used to acquire grayscale information from the external motherboard and control the current of the drive circuit according to the grayscale information to adjust the color temperature of the color temperature adjustable LED bead. The main control chip has a preset grayscale threshold.

8. The backlight module as described in claim 7, characterized in that, Multiple color temperature adjustable LED beads are spaced apart on the circuit board and arranged in a matrix.

9. The backlight module as described in claim 7, characterized in that, The backlight module forms multiple backlight control areas corresponding to multiple display sub-areas of the liquid crystal display panel, and each backlight control area contains at least one of the color temperature adjustable LED beads; the output terminal of the driving circuit is independently electrically connected to the color temperature adjustable LED beads in each backlight control area.

10. A backlight-adjustable liquid crystal display device, characterized in that, include: The liquid crystal display panel and the backlight module as described in any one of claims 7-9, wherein the backlight module is connected to one side of the liquid crystal display panel.

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