Display device and backlight control method

Abstract

This application discloses a display device and a backlight control method. The signal acquisition module includes a light-collecting unit for collecting ambient light intensity to generate a light detection signal; a signal amplification module for spectral shifting and amplification of the light detection signal followed by demodulation to obtain an amplified signal; a display resolution module for obtaining the average brightness of the image to be displayed on the display panel based on the image data; and a backlight control module for adjusting the brightness of the backlight provided by the backlight module to the display panel based on the amplified signal and the average brightness. By spectrally shifting and amplifying the light detection signal to obtain the amplified signal, the flicker noise of the signal amplification module itself can be reduced during the amplification process, improving the signal-to-noise ratio of the amplified signal and thus enhancing the accuracy of the backlight control module in adjusting the backlight brightness based on the amplified signal and the average brightness.

Description

Technical Field

[0001] This application relates to the field of display technology, specifically to a display device and a backlight control method. Background Technology

[0002] The backlight module provides a light source for the passive display panel to enable it to display content. Furthermore, the backlight brightness provided by the backlight module needs to adapt to different environments. However, the backlight brightness adjustment process is highly susceptible to factors such as circuit noise, leading to a decrease in brightness adjustment accuracy. Summary of the Invention

[0003] This application provides a display device and a backlight control method to reduce the impact of circuit noise on backlight brightness adjustment and improve the adjustment accuracy of backlight brightness.

[0004] This application provides a display device, including a display panel, a backlight module, a signal acquisition module, a signal amplification module, a display resolution module, and a backlight control module. The display panel is used to display an image, and the backlight module is configured to provide backlight to the display panel. The signal acquisition module includes a light-collecting unit configured to acquire the ambient light intensity of the environment in which the display panel is located, to generate a light detection signal. The signal amplification module is electrically connected to the signal acquisition module and is configured to perform spectrum shifting and amplification on the light detection signal before demodulation to obtain an amplified signal. The display resolution module is configured to obtain the average brightness corresponding to the image to be displayed on the display panel based on the image data of the image to be displayed. The backlight control module is electrically connected to the signal amplification module and the display resolution module and is configured to adjust the brightness of the backlight provided by the backlight module to the display panel based on the amplified signal and the average brightness.

[0005] This application also provides a backlight control method, comprising: acquiring the ambient light intensity of the environment in which the display panel is located to generate a light detection signal; performing spectrum shifting and amplification on the light detection signal and then demodulating it to obtain an amplified signal; acquiring image data of the image to be displayed on the display panel to obtain the average brightness corresponding to the image to be displayed; and adjusting the brightness of the backlight provided by the backlight module to the display panel according to the amplified signal and the average brightness.

[0006] In the above technical solution, the ambient light intensity is collected by the light-collecting unit in the signal acquisition module to generate a light detection signal. This light detection signal is then amplified and frequency-shifted by the signal amplification module before demodulation to obtain an amplified signal. The display resolution module obtains the average brightness of the image to be displayed on the display panel based on the image data. This allows the backlight control module to adjust the backlight brightness supplied to the display panel based on the amplified signal and the average brightness. Because the amplified signal is obtained by frequency shifting, amplification, and demodulation of the light detection signal by the signal amplification module, the flicker noise of the signal amplification module itself can be reduced during the amplification process, thus improving the signal-to-noise ratio of the amplified signal. Consequently, the accuracy of the backlight control module in adjusting the backlight brightness based on the amplified signal and the average brightness is improved. Attached Figure Description

[0007] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 This is a schematic diagram of the structure of the display device provided in an exemplary embodiment of this disclosure; Figure 2 This is a schematic block diagram of a backlight driving system provided by an exemplary embodiment of this disclosure; Figure 3 This is a comparison chart showing the effect of ambient brightness on different response speeds provided by exemplary embodiments of this disclosure; Figures 4A-4B This is a schematic flowchart of a backlight control method provided by an exemplary embodiment of this disclosure. Detailed Implementation

[0009] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0010] It should be noted that the electrical connection referred to in this application can include direct connection or indirect connection. Indirect connection can include connection between connected modules, devices, and nodes through electrical components, wired or wireless media, etc. Electrical connection can refer to a physically existing connection or a connection established through signals.

[0011] Furthermore, descriptions involving "first," "second," etc., in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified. The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict. Each technical feature in this application can be applied to achieve different combinations, and is not limited to the technical solutions formed by the combinations listed in the embodiments. Technical solutions between various embodiments can be combined, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application. The terms "optionally" and "in some embodiments" used in this application indicate that the technical content they refer to can be selectively set and are not necessarily interpreted as being more preferred or advantageous than other embodiments.

[0012] Furthermore, the descriptions provided in the Background section should not be presumed to be prior art simply because they are mentioned in or associated with the description in the Background section. The Background section may include information describing one or more aspects of the subject matter, and the description in this section does not limit the invention.

[0013] To enable any person skilled in the art to implement and use this application, the following description is provided. In this description, details are set forth for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be implemented without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0014] To overcome the fundamental limitation that liquid crystal materials cannot actively emit light, backlight modules are incorporated into passive illuminant displays. These backlight modules provide a light source for the passive illuminant panel, and by controlling the deflection of the liquid crystals to adjust the light transmittance, the brightness of the display can be controlled. Therefore, the brightness, uniformity, and energy efficiency of the light source provided by the backlight module directly affect the visual display quality and power consumption of the display panel. In practical applications, to balance display quality and power consumption, the backlight brightness provided by the backlight module is adaptively adjusted according to the environment in which the display panel is located. However, the backlight brightness adjustment process is highly susceptible to factors such as circuit noise, leading to a decrease in brightness adjustment accuracy.

[0015] Therefore, in order to improve the above problems, this application provides a display device and a backlight control method.

[0016] like Figure 1 This is a schematic diagram of the structure of a display device provided in an exemplary embodiment of this disclosure. This application provides a display device including a display panel 10 and a backlight driving system BS.

[0017] The display panel 10 is used to display images, and the backlight driving system BS is used to adjust the backlight brightness provided to the display panel 10.

[0018] In some embodiments, the display panel 10 is a passive light-emitting display panel 10. The passive light-emitting display panel 10 includes, but is not limited to, a liquid crystal display panel 10.

[0019] Understandably, the display panel 10 may include multiple sub-pixels Spx, which are used to implement the display function of the display panel 10. The display panel 10 may also include scan lines, data lines, and other parts not shown.

[0020] Figure 2 This is a schematic block diagram of a backlight driving system provided in an exemplary embodiment of this disclosure. The backlight driving system BS includes a backlight module 20, a signal acquisition module 30, a signal amplification module 40, a display resolution module 50, and a backlight control module 60.

[0021] The backlight module 20 is configured to provide backlight to the display panel 10. In some embodiments, the backlight module 20 may include a plurality of backlight sources 201, which may be light-emitting elements. The light-emitting elements include, but are not limited to, light-emitting diodes.

[0022] The signal acquisition module 30 includes a light-collecting unit 301, which is configured to collect the ambient light intensity of the environment where the display panel 10 is located in order to generate a light detection signal.

[0023] The signal amplification module 40 is electrically connected to the signal acquisition module 30. The signal amplification module 40 is configured to perform spectrum shifting and amplification on the optical detection signal before demodulation to obtain the amplified signal.

[0024] The display resolution module 50 is configured to obtain the average brightness of the image to be displayed based on the image data of the image to be displayed on the display panel 10.

[0025] The backlight control module 60 is electrically connected to the signal amplification module 40 and the display resolution module 50. The backlight control module 60 is configured to adjust the brightness of the backlight provided by the backlight module 20 to the display panel 10 according to the amplified signal and the average brightness.

[0026] Since the amplified signal is obtained by frequency shifting, amplification, and demodulation of the optical detection signal through the signal amplification module 40, the flicker noise of the signal amplification module 40 itself can be reduced during the process of amplifying the optical detection signal to obtain the amplified signal. This reduces the influence of the signal amplification module 40 itself on the conversion process from optical detection signal to amplified signal, thereby improving the signal-to-noise ratio of the amplified signal. Consequently, when the backlight control module 60 adjusts the backlight brightness according to the amplified signal and the average brightness, the backlight brightness adjustment accuracy is improved.

[0027] It should be noted that spectrum shifting of the optical detection signal refers to transferring the spectrum of the optical detection signal from a first frequency band to a second frequency band. The frequencies corresponding to the first frequency band are lower than the frequencies corresponding to the second frequency band.

[0028] Optionally, in order to perform spectrum shifting and amplification / demodulation on the optical detection signal to obtain an amplified signal, the signal amplification module 40 may include a chopper-stabilized amplifier. The chopper-stabilized amplifier is configured to shift the spectrum of the optical detection signal from the first frequency band to the second frequency band to obtain a modulated signal, and then amplify and demodulate the modulated signal to obtain an amplified signal.

[0029] By using a chopper-stabilized amplifier to shift the spectrum of the optical detection signal from the first frequency band to the second frequency band to obtain the modulation signal, the modulation signal can be amplified in a frequency band with extremely low amplifier noise and no offset error. This eliminates the influence of the amplifier's inherent DC offset voltage drift and flicker noise on the amplification process and result. After the modulation signal is amplified, its spectrum can be shifted from the second frequency band to the first frequency band, thus obtaining a high-precision amplified signal. The process of shifting the modulation signal's spectrum from the second frequency band to the first frequency band is the demodulation described above.

[0030] Optionally, to achieve the acquisition of light intensity, the light-collecting unit 301 may include at least one of a photodiode and a photoelectric sensor. The photodiode may be a photosensitive diode.

[0031] In some embodiments, photodiodes are sensitive to infrared light, thus the results collected by photodiodes include a significant infrared component. However, since the human eye is not sensitive to infrared light, when generating an amplified signal based on the light detection signal collected by the photodiode to adjust the backlight brightness, it can lead to the brightness adjustment being too bright or too dim. For example, under incandescent lamp brightness, the results collected by the photodiode include a large infrared component, and adjusting the backlight brightness based on the photodiode's light detection signal can result in a backlight brightness adjustment misjudgment rate greater than 20%.

[0032] Therefore, to improve the problem of backlight brightness adjustment being too dim or too bright due to invisible light factors, thus affecting the viewing experience, the light-collecting unit 301 can include multiple photoelectric sensors. At least one photoelectric sensor is configured to detect visible light and infrared light, so as to generate a visible light detection signal reflecting the intensity of visible light and an infrared light detection signal reflecting the intensity of infrared light based on the environment in which the display panel 10 is located. The light detection signal includes the visible light detection signal. The signal amplification module 40 is configured to obtain a visible light amplification signal based on the visible light detection signal, and the backlight control module 60 is configured to adjust the backlight brightness based on the visible light amplification signal and the average brightness, so that the backlight brightness adjustment is not affected by the infrared light component in the environment in which the display panel 10 is located, resulting in a better viewing experience.

[0033] In some embodiments, multiple photoelectric sensors can be arranged in an array to form a photoelectric sensor array, thereby improving the high-precision detection of the light intensity of the environment in which the display panel 10 is located.

[0034] In some embodiments, the photoelectric sensor can be a four-channel ambient light sensor. The four-channel ambient light sensor can be used to detect red, green, and blue light in the visible spectrum, and can also be used to detect invisible light. Invisible light includes, but is not limited to, infrared light.

[0035] In some embodiments, a compensation unit may be added separately. The compensation unit is used to detect the light intensity of invisible light in the environment where the display panel 10 is located, so as to use the detection result of the compensation unit to compensate the result of photodiode detection, so as to reduce the influence of invisible light included in the photodiode detection result on backlight brightness adjustment.

[0036] It should be understood that the above embodiments are all illustrated using infrared light as an example of invisible light, but this is not intended to limit invisible light to only infrared light. The principle of adjusting the effect of other non-infrared invisible light on the perception can be obtained by referring to the principle of improving the effect of infrared light on the perception, which will not be elaborated here.

[0037] Optionally, the backlight control module 60 may include a precision control unit 601, which is electrically connected to the signal amplification module 40. The precision control unit 601 is configured to adjust the backlight brightness according to the rate of change of ambient light intensity. By controlling the backlight brightness adjustment precision according to the rate of change of ambient light intensity, the backlight brightness can be quickly adjusted to match the environment in which the display panel 10 is located when the ambient light intensity changes significantly. Conversely, when the ambient light intensity changes slightly, the backlight brightness can be finely adjusted.

[0038] Optionally, different control signals can be generated based on the amplified signal to achieve backlight brightness adjustment under different light intensity change rates.

[0039] In some embodiments, the precision control unit 601 may include an analog-to-digital converter (ADC) 6011 and a processor 6012. The ADC 6011 is electrically connected to the signal amplification module 40, and the processor 6012 is electrically connected to the ADC 6011. When the rate of change of light intensity is less than a preset rate of change, the ADC 6011 is configured to convert the amplified signal into a first control signal, and the processor 6012 is configured to adjust the backlight brightness to a first precision based on the first control signal. When the rate of change of light intensity is greater than or equal to the preset rate of change, the ADC 6011 is configured to convert the amplified signal into a second control signal, and the processor 6012 is configured to adjust the backlight brightness to a second precision based on the second control signal. The first precision is higher than the second precision, so that the backlight control module 60 can adjust the backlight brightness to different precisions according to different light intensity changes.

[0040] It should be understood that the preset light intensity change rate can be set differently depending on the actual needs. For example, in some embodiments, the preset light intensity change rate can be greater than 1000 lux / s; lux / s means lux per second.

[0041] In some embodiments, the analog-to-digital converter 6011 may be a successive approximation analog-to-digital converter 6011.

[0042] In some embodiments, the analog-to-digital converter 6011 may include a first analog-to-digital converter with a first conversion accuracy and a second analog-to-digital converter with a second conversion accuracy, wherein the first conversion accuracy is higher than the second conversion accuracy. The first analog-to-digital converter is used to generate a first control signal, and the second analog-to-digital converter is used to generate a second control signal. When the light intensity changes rapidly, a lower-precision analog-to-digital converter is used to achieve a faster response in backlight adjustment through a faster response loop, and this also helps reduce the power consumption of the analog-to-digital converter during sampling. Conversely, when the rate of change in light intensity is gradual, a higher-precision analog-to-digital converter is used to improve the backlight adjustment accuracy.

[0043] In some embodiments, different mapping relationships can be applied to the amplified signal to obtain a first control signal or a second control signal for different light intensity change rates, thereby achieving different levels of adjustment of the backlight brightness.

[0044] In some embodiments, when the rate of change of light intensity is less than a preset rate of change of light intensity, the analog-to-digital converter 6011 is configured to convert the amplified signal into a first control signal according to a first mapping relationship. When the rate of change of light intensity is greater than or equal to the preset rate of change of light intensity, the analog-to-digital converter 6011 is configured to convert the amplified signal into a second control signal according to a second mapping relationship. The first mapping relationship characterizes the mapping relationship between the M levels of backlight brightness change and the amplified signal, and the second mapping relationship characterizes the mapping relationship between the N levels of backlight brightness change and the amplified signal; M>N. This allows for coarse adjustment of the backlight brightness when the rate of change of light intensity is large, enabling the backlight brightness to quickly match the ambient light intensity of the display panel 10. When the rate of change of light intensity is greater than or equal to the preset rate of change of light intensity, fine adjustment of the backlight brightness allows for a more precise match between the backlight brightness and the ambient light intensity of the display panel 10.

[0045] In some embodiments, N≥2, and M and N are positive integers.

[0046] It should be understood that the first and second mapping relationships can be determined during the debugging phase. The brightness adjustment levels corresponding to different light intensity change rates can be divided into different levels according to different needs. In some embodiments, the mapping relationships between the M levels of backlight brightness change and the amplified signal can be stored in the form of a first lookup table, and the mapping relationships between the N levels of backlight brightness change and the amplified signal can be stored in the form of a second lookup table. When generating the corresponding control signal based on the amplified signal and the light intensity change rate, either the first or second lookup table can be directly invoked.

[0047] It should be noted that backlight adjustment levels with varying degrees of precision can be defined based on the rate of change of light intensity.

[0048] In some embodiments, to improve the control accuracy of backlight brightness adjustment, the analog-to-digital converter 6011 may include a first filter and a signal converter. The first filter is electrically connected to the signal amplification module 40 and is configured to filter sampled data obtained by sampling based on the amplified signal to obtain a filtered signal. The signal converter is electrically connected to the first filter and is configured to obtain a control signal for adjusting the backlight based on the filtered signal.

[0049] In some embodiments, to enable faster response speed of backlight adjustment when the light intensity change rate is large, and to improve backlight adjustment accuracy when the light intensity change rate is small, the first filter can be configured to have different filtering strengths under different light intensity change rates.

[0050] That is, Figure 3 This is a comparison chart showing the effect of ambient brightness on different response speeds provided by exemplary embodiments of this disclosure. Figure 3 In this context, L1 represents ambient brightness, L2 corresponds to the case with a smaller time constant, and L3 corresponds to the case with a larger time constant.

[0051] When the rate of change of light intensity is less than a preset rate of change of light intensity, the first filter is configured to filter the first sampled data obtained by sampling the amplified signal with a first filter intensity to obtain a first filtered signal. The signal converter is configured to obtain a first control signal based on the first filtered signal when the rate of change of light intensity is less than the preset rate of change of light intensity. When the rate of change of light intensity is greater than or equal to the preset rate of change of light intensity, the first filter is configured to filter the second sampled data obtained by sampling the amplified signal with a second filter intensity to obtain a second filtered signal. The signal converter obtains a second control signal based on the second filtered signal when the rate of change of light intensity is greater than or equal to the preset rate of change of light intensity. The first filter intensity is greater than the second filter intensity to reduce the filtering intensity of the first filter on the sampled signal when the rate of change of light intensity is large and the illumination changes rapidly, thereby reducing the time constant of the first filter and accelerating the response speed to backlight adjustment. When the rate of change of light intensity is small and the illumination changes gradually, the filtering intensity of the first filter on the sampled signal is increased, thereby increasing the time constant of the first filter, which helps to better suppress noise and improve the signal-to-noise ratio of the first control signal.

[0052] In some embodiments, when the rate of change of light intensity is less than a preset rate of change of light intensity, the first filter in the first analog-to-digital converter is configured to filter the first sampled data with a first filtering intensity to obtain a first filtered signal. The signal converter in the first analog-to-digital converter is configured to obtain a first control signal based on the first filtered signal when the rate of change of light intensity is less than the preset rate of change of light intensity. When the rate of change of light intensity is greater than or equal to the preset rate of change of light intensity, the first filter in the second analog-to-digital converter is configured to filter the second sampled data with a second filtering intensity to obtain a second filtered signal. The signal converter in the second analog-to-digital converter obtains a second control signal based on the second filtered signal when the rate of change of light intensity is greater than or equal to the preset rate of change of light intensity.

[0053] In some embodiments, when the rate of change of light intensity is less than a preset rate of change of light intensity, mean filtering can be used to filter the first sampled data obtained by sampling based on the amplified signal.

[0054] In some embodiments, when the rate of change of light intensity is greater than or equal to a preset rate of change of light intensity, the light intensity can be predicted so that the backlight brightness can be adjusted according to the predicted light intensity and the second mapping relationship, so that the backlight brightness can quickly adapt to changes in illumination. The prediction can be based on the currently detected light intensity and the previously detected light intensity. That is: Predict_lux = Current_lux + beta × (Current_lux - Prev_lux). Predict_lux represents the predicted light intensity, Current_lux represents the currently detected light intensity, and Prev_lux represents the previously detected light intensity, which is the data obtained before the currently detected light intensity. beta represents an adjustable parameter defined for display effect during the application process. The adjustable parameter can have different values ​​depending on the actual application.

[0055] Optionally, because the ambient light in the environment where the display panel 10 is located varies in intensity, the dynamic range of the light detection signal generated by the light-collecting unit 301 is extremely wide, as is the dynamic range of the amplified signal generated based on the light detection signal. The digital-to-analog converter (DAC) cannot maintain high-precision sampling and conversion across such a wide range. Therefore, to ensure that the DAC 6011 can still achieve high-precision signal conversion across a wide range of brightness variations, the precision control unit 601 can further include a gain adjuster 6013.

[0056] Gain regulator 6013 is electrically connected between signal amplification module 40 and analog-to-digital converter 6011. Gain regulator 6013 is configured to adjust the gain of the amplified signal transmitted to analog-to-digital converter 6011 according to the illumination range of the ambient light intensity, so that analog-to-digital converter 6011 can achieve high-precision sampling conversion for different illumination ranges.

[0057] In some embodiments, when the light intensity is low, the gain amplification factor can be increased by the gain regulator 6013 so that the analog-to-digital converter 6011 can sample and convert the amplified signal based on the high gain amplification factor. Conversely, when the light intensity is high, the gain amplification factor can be decreased by the gain regulator 6013 so that all the information represented by the amplified signal can be received by the analog-to-digital converter 6011, thereby supporting the analog-to-digital converter 6011 in effectively sampling and converting the amplified signal.

[0058] The gain amplification factor can vary depending on the illumination range. The value of the gain amplification factor can be determined based on the voltage range that the analog-to-digital converter 6011 can receive and the voltage range corresponding to the amplified signal. For example, if the voltage range that the analog-to-digital converter 6011 can receive is 0V~1000V, and the voltage range of the amplified signal for the first illumination range is 10V~100V, then the gain amplification factor can be set to 10. For the second illumination range, the voltage range of the amplified signal is 10V~500V, then the gain amplification factor can be set to 2.

[0059] In some embodiments, the gain regulator 6013 may be an adjustable feedback resistor network.

[0060] Optionally, the display resolution module 50 may include an image resolution unit 501 and a compensation generation unit 502. The image resolution unit 501 is configured to obtain the proportion of white space in the image to be displayed based on the image data of the image to be displayed, thereby obtaining the average brightness corresponding to the image to be displayed. The compensation generation unit 502 is electrically connected to the image resolution unit 501, and is configured to generate first compensation data based on the average brightness corresponding to the image to be displayed when the rate of change of the average brightness corresponding to two adjacent display frames is greater than a preset rate of change of brightness. When the rate of change of the average brightness corresponding to two adjacent display frames is greater than the preset rate of change of brightness, the processor 6012 is configured to adjust the backlight brightness based on one of a first control signal and a second control signal and the first compensation data, thereby adjusting the backlight to blend with the brightness of the display content of the display panel 10.

[0061] If 10% of the area in the image to be displayed is white and 90% is black, then the average brightness of the image to be displayed is 10%.

[0062] In some embodiments, based on the stored ambient light and the required backlight brightness under corresponding ambient brightness, a first control signal or a second control signal for adjusting the backlight can be obtained through an analog comparator and digital logic circuits, a microcontroller, etc., and then combined with first compensation data obtained based on average brightness to obtain the final control signal for adjusting the backlight. The first mapping relationship and the second mapping relationship can respectively represent the ambient light and the required backlight brightness under corresponding ambient brightness.

[0063] In some embodiments, when the ambient brightness is high, if the display resolution module 50 determines that the brightness of the content to be displayed on the display panel 10 is low, high contrast display can be achieved by reducing the backlight brightness, so as to show more details of the displayed content.

[0064] When the rate of change of average brightness between two adjacent display frames is less than or equal to a preset rate of change of brightness, the processor 6012 is configured to adjust the backlight brightness according to one of the first control signal and the second control signal, so that the backlight brightness adjustment does not change with the display content.

[0065] In some embodiments, the processor 6012 may be multiplexed as at least one of an image resolution unit 501, a compensation generation unit 502, and a gain adjuster.

[0066] In some embodiments, the display device includes a timing controller, which is multiplexed as at least one of an image resolution unit 501, a compensation generation unit 502, and a gain regulator.

[0067] Optionally, the processor 6012 includes a pulse width modulation circuit configured to adjust the duty cycle of the output pulse width modulation signal according to one of a first control signal and a second control signal and first compensation data to adjust the brightness of the backlight.

[0068] It should be understood that the first control signal, the second control signal, and the first compensation data can each change the duty cycle of the pulse width modulation signal. When the rate of change of the average brightness corresponding to two adjacent display frames is less than or equal to the preset rate of change of brightness, the pulse width modulation circuit can adjust the duty cycle of the output pulse width modulation signal according to only one of the first control signal and the second control signal to adjust the brightness of the backlight.

[0069] Optionally, the display device further includes a power supply module 70, which is electrically connected to the signal amplification module 40. The power supply module 70 is configured to provide a power signal to the signal amplification module 40. The power supply module 70 includes a second filter, which is configured to filter the power signal to reduce the impact of power ripple, noise, etc. on the backlight brightness adjustment accuracy.

[0070] In some embodiments, the second filter is a π-type filter network, which includes at least one of a capacitor, a resistor, an inductor, etc.

[0071] In some embodiments, the second filter includes an input capacitor, a resistor, and an output capacitor. The input capacitor is used to filter out some high-frequency noise in the power supply signal, while the resistor and the output capacitor together form a low-pass filter to further filter out high-frequency noise.

[0072] Optionally, the signal acquisition module 30 further includes a temperature acquisition unit 302, which is configured to detect the temperature of the environment in which the display panel 10 is located, in order to generate a temperature detection signal. The backlight control module 60 is also configured to adjust the brightness of the backlight based on the temperature detection signal.

[0073] Optionally, the temperature acquisition unit 302 includes a temperature sensor. The temperature sensor includes, but is not limited to, an integrated high-precision temperature sensor (such as a bandgap reference source circuit).

[0074] In some embodiments, the response curves of the temperature sampling unit 302 under different temperatures and different light conditions can be stored in advance, and the brightness mapping curves of the backlight at different temperatures can be obtained through debugging. In order to adjust the backlight brightness according to the temperature, different brightness curves can be called according to different temperatures based on the temperature data measured by the temperature sampling unit 302 and the pre-stored data, so that the backlight output brightness is as consistent as possible when the temperature changes, thereby realizing the correction of the backlight brightness adjustment accuracy.

[0075] In some embodiments, the backlight brightness can be adjusted according to the frame rate. That is, when the frame rate is greater than or equal to a preset frame rate, the backlight control module 60 adjusts the duty cycle of the pulse width modulation signal according to the frame rate so that the backlight brightness does not fluctuate as the display content update speed increases. When the frame rate is less than the preset frame rate, the backlight control module 60 adjusts the backlight brightness according to the amplified signal and the average brightness.

[0076] It should be understood that the preset frame rate can be set differently depending on actual needs.

[0077] In the comparative embodiment, a discrete transimpedance amplifier was used to obtain the amplified signal. However, discrete transimpedance amplifiers are prone to power supply ripple interference and cannot eliminate their own flicker noise. Therefore, the signal-to-noise ratio of the amplified signal obtained using a discrete transimpedance amplifier based on a nanometer-scale weak light detection signal is low. In this application, by using a chopper-stabilized amplifier to amplify the light detection signal, it is beneficial to reduce the impact of the amplifier's inherent DC offset voltage drift and flicker noise on the amplification process and amplification result, thereby improving the signal-to-noise ratio of the amplified signal. In addition, this application also uses a second filter to filter the power supply signal, which is beneficial to reduce power supply ripple interference, thereby improving the signal-to-noise ratio of the control signal generated based on the weak light signal for adjusting the backlight brightness.

[0078] In the comparative embodiment, a fixed brightness curve is used to adjust the backlight, resulting in a rigid backlight brightness adjustment control chain. In this application, however, the backlight is adjusted not only based on the ambient light intensity of the display panel 10, but also based on the rate of change of light intensity, which helps to meet brightness adjustment requirements under different rates of change of light intensity. Furthermore, this application can also adjust the backlight brightness based on at least one of the displayed content, temperature, etc., making backlight brightness adjustment more flexible.

[0079] Therefore, in this application, by including a photoelectric sensor capable of detecting visible and infrared light in the light-collecting unit 301, the amount of data collected on light parameters can be increased, which helps to eliminate interference from non-visible light on backlight adjustment, improves the accuracy of backlight adjustment, and alleviates the problem of poor spectral matching in backlight adjustment. The addition of a chopper-stabilized amplifier reduces the impact of the amplifier's inherent noise on backlight adjustment accuracy. The addition of a second filter reduces the impact of power supply ripple on backlight adjustment accuracy. Adjusting the backlight based on at least one of ambient light intensity, the average brightness change rate corresponding to the displayed image, and temperature makes backlight adjustment more flexible and improves the problem of rigid backlight brightness control links. By adjusting the filtering intensity of the signal sampled by the first filter according to the light intensity change rate to adjust the response speed of backlight brightness adjustment, the probability of abnormal brightness display on the display panel 10 caused by sudden brightness changes can be reduced, which helps to improve the problem of poor backlight adjustment stability. Therefore, the display device of this application can achieve a low-noise, low-power backlight adjustment control design.

[0080] Figures 4A-4B This is a schematic flowchart of a backlight control method provided by an exemplary embodiment of this disclosure. This application also provides a backlight control method for any of the above-described display devices.

[0081] Backlight control methods include: Step S10: Collect the ambient light intensity of the environment where the display panel 10 is located to generate a light detection signal; Step S20: Spectral shift and amplification of the optical detection signal followed by demodulation to obtain the amplified signal; Step S30: Obtain the image data of the screen to be displayed on the display panel 10 to obtain the average brightness corresponding to the screen to be displayed; Step S40: Adjust the brightness of the backlight provided by the backlight module 20 to the display panel 10 according to the amplified signal and average brightness.

[0082] Step S10 can be executed through the light-collecting unit 301, step S20 can be executed through the signal amplification module 40, step S30 can be executed through the display resolution module 50, and step S40 can be executed through the backlight control module 60.

[0083] In some embodiments, the light detection signal includes a visible light detection signal reflecting the intensity of visible light. Accordingly, step S20 includes: spectral shifting and amplification of the visible light detection signal followed by demodulation to obtain an amplified visible light signal. Step 40 includes: adjusting the backlight brightness based on the amplified visible light signal and the average brightness. This reduces the influence of invisible light in the ambient light on the backlight adjustment.

[0084] In some embodiments, to achieve higher accuracy in backlight adjustment when the light intensity change rate is relatively flat, and to achieve a faster response speed in backlight adjustment when the light intensity change rate is relatively fast, step 40 may include: Step S401: When the rate of change of ambient light intensity is less than the preset rate of change of ambient light intensity, the amplified signal is converted into a first control signal, so as to select the first precision to adjust the brightness of the backlight according to the first control signal.

[0085] Step S402: When the light intensity change rate is greater than or equal to the preset light intensity change rate, the amplified signal is converted into a second control signal, so as to select a second precision to adjust the backlight brightness according to the second control signal. The first precision is higher than the second precision.

[0086] Steps S401 and S402 can be performed by analog-to-digital converter 6011.

[0087] In some embodiments, step S40 further includes: Step S40a: When the light intensity change rate is less than the preset light intensity change rate, the first sampled data obtained by sampling based on the amplified signal is filtered with the first filter intensity to obtain the first filtered signal, and the first control signal is obtained based on the first filtered signal.

[0088] Step S40b: When the light intensity change rate is greater than or equal to the preset light intensity change rate, the second sampled data obtained by sampling based on the amplified signal is filtered with a second filter intensity to obtain a second filtered signal, and a second control signal is obtained based on the second filtered signal. The first filter intensity is greater than the second filter intensity. In this way, the response speed of the backlight adjustment can be different according to the different light intensity change rates.

[0089] Steps S40a and S40b can be performed jointly by the first filter and the signal converter.

[0090] In some embodiments, step S40 includes: when the rate of change of the average brightness corresponding to two adjacent display frames is greater than a preset rate of change of brightness, generating first compensation data based on the average brightness corresponding to the image to be displayed, and adjusting the backlight brightness based on one of a first control signal and a second control signal and the first compensation data. This allows the degree of backlight adjustment to be corrected according to different display content.

[0091] In some embodiments, step S40 includes: when the rate of change of average brightness corresponding to two adjacent display frames is less than or equal to a preset rate of change of brightness, adjusting the brightness of the backlight according to one of a first control signal and a second control signal.

[0092] In some embodiments, the backlight control method further includes: Step S50: Detect the temperature of the environment in which the display panel 10 is located to generate a temperature detection signal.

[0093] Step S60: Obtain second compensation data based on the temperature detection signal, and adjust the duty cycle of the pulse width modulation signal based on the amplified signal, average brightness, and second compensation data to adjust the backlight brightness according to the pulse width modulation signal. In this way, the backlight adjustment can be corrected according to the temperature of the environment in which the display panel 10 is located.

[0094] Specifically, step S50 can be executed by the temperature sampling unit 302 and step S60 can be executed by the backlight control module 60.

[0095] Please continue reading. Figure 4B For ease of understanding this application, Figure 4B The backlight control method of this application will be briefly described using an example.

[0096] In this application, the adjustment of backlight brightness based on ambient light and the adjustment of backlight brightness based on the average brightness of the image to be displayed can be performed in parallel. That is, while the ambient light is sampled by the light-collecting unit 301, the average brightness of the image to be displayed can be obtained synchronously by the image analysis unit 501.

[0097] After the ambient light intensity is collected by the light-collecting unit 301 to generate a light detection signal, the light detection signal can be spectrum shifted and amplified to obtain an amplified signal. Based on the amplified signal, the light intensity change rate of the environment in which the display panel 10 is located can be obtained. Comparing the obtained light intensity change rate with a preset light intensity change rate reveals their magnitude relationship. Therefore, when the light intensity change rate is less than the preset light intensity change rate, the first sampled data obtained from sampling the amplified signal is filtered with a first filter intensity to obtain a first filtered signal. A first control signal is then generated based on the first filtered signal to select a first precision for adjusting the backlight brightness. At this time, the backlight control module 60 can generate a first pulse width modulation signal.

[0098] When the rate of change of light intensity is greater than or equal to a preset rate of change of light intensity, the second sampled data obtained by sampling based on the amplified signal is filtered with a second filter intensity to obtain a second filtered signal. A second control signal is then generated based on the second filtered signal to select a second precision control for backlight brightness adjustment. At this time, the backlight control module 60 can generate a second pulse width modulation signal, the duty cycle of which may differ from the duty cycle of the first pulse width modulation signal.

[0099] When the average brightness of the screen to be displayed is greater than the preset brightness change rate, first compensation data is generated based on the average brightness of the screen to be displayed. Then, a third pulse width modulation signal is generated based on the first compensation data. The duty cycle of one of the first pulse width modulation signal and the second pulse width modulation signal is adjusted based on the third pulse width modulation signal, thereby obtaining the pulse width modulation signal actually used to adjust the backlight brightness.

[0100] Therefore, when the average brightness of the screen to be displayed is greater than the preset brightness change rate, the pulse width modulation signal actually used to adjust the backlight brightness is obtained based on one of the first control signal and the second control signal, as well as the first compensation data.

[0101] However, when the average brightness of the screen to be displayed is less than or equal to the preset brightness change rate, if the light intensity change rate is less than the preset light intensity change rate, then the first pulse width modulation signal corresponds to the pulse width modulation signal actually used to adjust the backlight brightness.

[0102] When the average brightness of the screen to be displayed is less than or equal to the preset brightness change rate, if the light intensity change rate is greater than or equal to the preset light intensity change rate, then the second pulse width modulation signal corresponds to the pulse width modulation signal actually used to adjust the backlight brightness.

[0103] In some embodiments, the third pulse width modulation signal can be obtained based on the average brightness of the image to be displayed. That is, the third pulse width modulation signal PWM_C = 1.25 - 0.0025 × APL. Here, APL represents the average brightness of the image to be displayed. 1.25 and 0.0025 are determined by the data format extracted from the average brightness of the image to be displayed.

[0104] It should be noted that since the backlight control method of this application corresponds to the aforementioned display device, the backlight control method of this application possesses all the beneficial effects of the aforementioned display device, which will not be elaborated further here.

[0105] This embodiment also provides a computer-readable storage medium having a computer program stored thereon, the computer program being loaded by a processor to perform the steps of any of the methods in the above embodiments.

[0106] In the embodiments of this application, the storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM), etc.

[0107] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0108] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A display device, characterized in that, include: The display panel is used to display the screen. A backlight module is configured to provide backlight to the display panel; The signal acquisition module includes a light-collecting unit, which is configured to collect the ambient light intensity of the environment in which the display panel is located, in order to generate a light detection signal; The signal amplification module, electrically connected to the signal acquisition module, is configured to perform spectrum shifting and amplification on the optical detection signal before demodulation to obtain the amplified signal. The display analysis module is configured to obtain the average brightness of the image to be displayed based on the image data of the image to be displayed on the display panel. A backlight control module, electrically connected to the signal amplification module and the display resolution module, is configured to adjust the brightness of the backlight provided by the backlight module to the display panel according to the amplified signal and the average brightness.

2. The display device according to claim 1, characterized in that, The signal amplification module includes: A chopper-stabilized amplifier is configured to shift the spectrum of the optical detection signal from a first frequency band to a second frequency band to obtain a modulated signal, and to amplify and demodulate the modulated signal to obtain the amplified signal. The frequency corresponding to the first frequency band is lower than the frequency corresponding to the second frequency band.

3. The display device according to claim 1, characterized in that, The light-collecting unit includes multiple photoelectric sensors, at least one of which is configured to detect visible light and infrared light to generate a visible light detection signal reflecting the intensity of the visible light and an infrared light detection signal reflecting the intensity of the infrared light, wherein the light detection signal includes the visible light detection signal. The signal amplification module is configured to obtain a visible light amplification signal based on the visible light detection signal, and the backlight control module is configured to adjust the brightness of the backlight based on the visible light amplification signal and the average brightness.

4. The display device according to any one of claims 1 to 3, characterized in that, The backlight control module includes: The precision control unit, electrically connected to the signal amplification module, is configured to adjust the backlight variation precision according to the rate of change of ambient light intensity.

5. The display device according to claim 4, characterized in that, The accuracy control unit includes: An analog-to-digital converter, electrically connected to the signal amplification module, is configured to convert the amplified signal into a first control signal when the rate of change of light intensity is less than a preset rate of change of light intensity; and is configured to convert the amplified signal into a second control signal when the rate of change of light intensity is greater than or equal to the preset rate of change of light intensity. The processor, electrically connected to the analog-to-digital converter, is configured to adjust the brightness of the backlight with a first precision according to the first control signal when the light intensity change rate is less than a preset light intensity change rate; and is configured to adjust the brightness of the backlight with a second precision according to the second control signal when the light intensity change rate is greater than or equal to the preset light intensity change rate. The first precision is higher than the second precision.

6. The display device according to claim 5, characterized in that, When the rate of change of light intensity is less than a preset rate of change of light intensity, the analog-to-digital converter is configured to convert the amplified signal into a first control signal according to a first mapping relationship; When the light intensity change rate is greater than or equal to the preset light intensity change rate, the analog-to-digital converter is configured to convert the amplified signal into a second control signal according to the second mapping relationship; Wherein, the first mapping relationship is used to characterize the mapping relationship between the M levels of brightness change of the backlight and the amplified signal, and the second mapping relationship is used to characterize the mapping relationship between the N levels of brightness change of the backlight and the amplified signal; M>N.

7. The display device according to claim 5, characterized in that, The accuracy control unit includes: A gain regulator, electrically connected between the signal amplification module and the analog-to-digital converter, is configured to adjust the gain of the amplified signal transmitted to the analog-to-digital converter according to the illumination range to which the ambient light intensity belongs.

8. The display device according to claim 5, characterized in that, The analog-to-digital converter includes: A first filter, electrically connected to the signal amplification module, is configured to filter first sampled data obtained by sampling the amplified signal with a first filter intensity when the light intensity change rate is less than a preset light intensity change rate, to obtain a first filtered signal; and is configured to filter second sampled data obtained by sampling the amplified signal with a second filter intensity when the light intensity change rate is greater than or equal to a preset light intensity change rate, to obtain a second filtered signal. A signal converter, electrically connected to the first filter, is configured to obtain the first control signal based on the first filtered signal when the light intensity change rate is less than a preset light intensity change rate; and is configured to obtain the second control signal based on the second filtered signal when the light intensity change rate is greater than or equal to the preset light intensity change rate. The first filter strength is greater than the second filter strength.

9. The display device according to claim 5, characterized in that, The display parsing module: The image analysis unit is configured to obtain the proportion of white in the image to be displayed based on the image data of the image to be displayed, so as to obtain the average brightness of the image to be displayed. The compensation generation unit is electrically connected to the image analysis unit and is configured to generate first compensation data based on the average brightness corresponding to the image to be displayed when the rate of change of the average brightness corresponding to two adjacent display frames is greater than a preset rate of change of brightness. Wherein, when the rate of change of the average brightness corresponding to two adjacent display frames is greater than the preset rate of change of brightness, the processor is configured to adjust the brightness of the backlight according to one of the first control signal and the second control signal and the first compensation data.

10. The display device according to claim 9, characterized in that, When the rate of change of the average brightness corresponding to two adjacent display frames is less than or equal to a preset rate of change of brightness, the processor is configured to adjust the brightness of the backlight according to one of the first control signal and the second control signal.

11. The display device according to claim 9, characterized in that, The processor includes a pulse width modulation circuit configured to adjust the duty cycle of an output pulse width modulation signal according to one of a first control signal and a second control signal and the first compensation data, so as to adjust the brightness of the backlight.

12. The display device according to any one of claims 1 to 3, characterized in that, Also includes: A power supply module, electrically connected to the signal amplification module, is configured to provide a power signal to the signal amplification module, and includes a second filter configured to filter the power signal.

13. The display device according to any one of claims 1 to 3, characterized in that, The signal acquisition module also includes: The temperature sensing unit is configured to detect the temperature of the environment in which the display panel is located in order to generate a temperature detection signal; The backlight control module is further configured to adjust the brightness of the backlight based on the temperature detection signal.

14. A backlight control method, characterized in that, The backlight control method includes: The ambient light intensity of the environment in which the display panel is located is collected to generate a light detection signal; The optical detection signal is then spectrum-shifted, amplified, and demodulated to obtain the amplified signal. The image data of the image to be displayed on the display panel is obtained to obtain the average brightness corresponding to the image to be displayed; The brightness of the backlight provided to the display panel by the backlight module is adjusted according to the amplified signal and the average brightness.

15. The backlight control method according to claim 14, characterized in that, The light detection signal includes a visible light detection signal that reflects the intensity of visible light; The step of performing spectrum shifting and amplification on the optical detection signal and then demodulating it to obtain an amplified signal includes: performing spectrum shifting and amplification on the visible light detection signal and then demodulating it to obtain a visible light amplified signal; The step of adjusting the brightness of the backlight provided by the backlight module to the display panel according to the amplified signal and the average brightness includes: adjusting the brightness of the backlight according to the visible light amplified signal and the average brightness.

16. The backlight control method according to claim 14, characterized in that, The step of adjusting the brightness of the backlight provided by the backlight module to the display panel based on the amplified signal and the average brightness includes: When the rate of change of ambient light intensity is less than the preset rate of change of ambient light intensity, the amplified signal is converted into a first control signal, and the brightness of the backlight is adjusted according to the first control signal with a first precision. When the light intensity change rate is greater than or equal to the preset light intensity change rate, the amplified signal is converted into a second control signal, so as to select a second precision to adjust the brightness of the backlight according to the second control signal; The first precision is higher than the second precision.

17. The backlight control method according to claim 16, characterized in that, The step of adjusting the brightness of the backlight provided by the backlight module to the display panel based on the amplified signal and the average brightness further includes: When the light intensity change rate is less than the preset light intensity change rate, the first sampled data obtained by sampling based on the amplified signal is filtered with a first filter intensity to obtain a first filtered signal, and the first control signal is obtained based on the first filtered signal. When the light intensity change rate is greater than or equal to the preset light intensity change rate, the second sampled data obtained by sampling based on the amplified signal is filtered with a second filter intensity to obtain a second filtered signal, and the second control signal is obtained based on the second filtered signal; The first filter strength is greater than the second filter strength.

18. The backlight control method according to claim 16, characterized in that, The step of adjusting the brightness of the backlight provided by the backlight module to the display panel based on the amplified signal and the average brightness includes: When the rate of change of the average brightness corresponding to two adjacent display frames is greater than the preset rate of change of brightness, first compensation data is generated based on the average brightness corresponding to the display frame, and the brightness of the backlight is adjusted based on one of the first control signal and the second control signal and the first compensation data.

19. The backlight control method according to claim 16, characterized in that, The step of adjusting the brightness of the backlight provided by the backlight module to the display panel based on the amplified signal and the average brightness includes: When the rate of change of the average brightness corresponding to two adjacent display frames is less than or equal to the preset rate of change of brightness, the brightness of the backlight is adjusted according to one of the first control signal and the second control signal.

20. The backlight control method according to claim 14, characterized in that, The backlight control method further includes: The temperature of the environment in which the display panel is located is detected to generate a temperature detection signal; The second compensation data is obtained based on the temperature detection signal, and the duty cycle of the pulse width modulation signal is adjusted based on the amplified signal, the average brightness, and the second compensation data, so as to adjust the brightness of the backlight according to the pulse width modulation signal.

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