Backlight control circuit of screen, and virtual reality device

Abstract

A backlight control circuit of a screen, and a virtual reality device. The backlight control circuit comprises: a control circuit, a boost circuit, a backlight circuit, a constant current source circuit, and a screen, wherein the control circuit is separately connected to the boost circuit, the screen, and the constant current source circuit, and the backlight circuit is separately connected to the boost circuit, the screen, and the constant current source circuit; the boost circuit is used for outputting voltage to supply power to the backlight circuit; the constant current source circuit is used for controlling the current of the backlight circuit to be constant; the control circuit is used for controlling, by means of the screen, a light-emitting element in the backlight circuit to be turned on or turned off, and controlling the boost circuit on the basis of the voltage of the constant current source circuit. The power consumption of the backlight control circuit is reduced, and the accuracy of voltage control is improved.

Description

Screen backlight control circuit and virtual reality device

[0001] This application claims priority to Chinese Patent Application No. 202311630504.7 filed on November 30, 2023, and the contents of the above-mentioned Chinese patent application disclosure are hereby incorporated by reference in their entirety as a part of this application. Technical Field

[0002] The embodiments of the present disclosure relate to a backlight control circuit for a screen and a virtual reality device. Background Art

[0003] The optical display effect of the screen in a virtual reality (VR) device is related to the user's experience of using the VR device.

[0004] Currently, VR devices can adjust screen brightness using low-frequency pulse-width modulation (PWM) signals. For example, a VR device can use a PWM signal to control the screen's light bulb to stay on for 10% of the time, thus avoiding prolonged lighting while still maintaining the desired display quality. However, the boost circuit is under low load and inefficient, resulting in high power consumption. Summary of the Invention

[0005] The present disclosure provides a screen backlight control circuit and a virtual reality device, which are used to solve the technical problem of high circuit power consumption.

[0006] In a first aspect, the present disclosure provides a backlight control circuit for a screen, the backlight control circuit for the screen comprising: a control circuit, a boost circuit, a backlight circuit, a constant current source circuit and a screen, wherein:

[0007] The control circuit is connected to the boost circuit, the screen and the constant current source circuit respectively, and the backlight circuit is connected to the boost circuit, the screen and the constant current source circuit respectively;

[0008] The boost circuit is used to output a voltage to supply power to the backlight circuit, and the constant current source circuit is used to control the current of the backlight circuit to be constant;

[0009] The control circuit is used to control the lighting or extinguishing of the light-emitting elements in the backlight circuit through the screen, and to control the boost circuit according to the voltage of the constant current source circuit.

[0010] In a second aspect, the present disclosure provides a virtual reality device, comprising a glasses body and the backlight control circuit described in the first aspect, wherein the backlight control circuit is arranged in the glasses body. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, a brief introduction will be given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0012] FIG1 is a schematic diagram of an application scenario provided by an embodiment of the present disclosure;

[0013] FIG2 is a schematic structural diagram of a backlight control circuit provided by an embodiment of the present disclosure;

[0014] FIG3 is a schematic structural diagram of another backlight control circuit provided by an embodiment of the present disclosure;

[0015] FIG4 is a voltage schematic diagram of a constant current source circuit provided by an embodiment of the present disclosure;

[0016] FIG5 is a schematic structural diagram of another backlight control circuit provided by an embodiment of the present disclosure;

[0017] FIG6 is a schematic diagram of the working process of a backlight control circuit provided by an embodiment of the present disclosure;

[0018] FIG7 is a schematic structural diagram of another backlight control circuit provided by an embodiment of the present disclosure;

[0019] FIG8 is a schematic diagram of a comparison result provided by an embodiment of the present disclosure;

[0020] FIG9 is a schematic diagram showing the relationship between a boost circuit and a comparator provided by an embodiment of the present disclosure; and

[0021] FIG10 is a schematic diagram of the working process of a backlight control circuit provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0022] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0023] The application scenario of the embodiment of the present disclosure is described below with reference to FIG1 .

[0024] Figure 1 is a schematic diagram of an application scenario provided by an embodiment of the present disclosure. Please refer to Figure 1, which includes a virtual reality device. Among them, the screen of the virtual reality device can play virtual reality videos. When the virtual reality device is in use, the light-emitting elements in the screen do not need to be always on. For example, the light-emitting elements in the screen can be periodically lit for 0.5 seconds and off for 0.5 seconds. In this way, the screen brightness in the virtual reality device can be adjusted and the playback effect of the screen can be guaranteed. It should be noted that when the screen brightness is increased, the proportion of the time the light-emitting elements are lit can be increased, and when the screen brightness is lowered, the proportion of the time the light-emitting elements are lit can be reduced. In addition, this disclosure only uses a cycle of 1 second as an example, and the actual working cycle of the light-emitting elements in the screen can be much less than 1 second.

[0025] It should be noted that FIG1 is only an illustrative illustration of the application scenario of the embodiment of the present disclosure, and does not limit the application scenario of the embodiment of the present disclosure.

[0026] In the related art, the optical display quality of the screen in a VR device is closely related to the user experience of using the VR device. Currently, VR device screen brightness can be adjusted using a low-frequency PWM signal. Because the human eye experiences image delay, a low-frequency PWM signal not only ensures the screen's display quality but also prevents the screen's light-emitting elements from being continuously illuminated. For example, a VR device can control the screen's on-time to 10% based on a PWM signal. This means that the light-emitting elements are off 90% of the time and illuminated 10% of the time. Due to the high brightness required for VR device screens, the backlight current is high, necessitating a voltage boost for the light-emitting elements. Currently, a constant-voltage boost circuit combined with a high-output capacitor can be used to power the screen backlight, achieving a high boost ratio and short-term high current requirements. However, after the voltage reaches the boost value, the constant-voltage boost circuit stops operating, while current continues to flow into the boost circuit. This results in a low-load, low-efficiency state for the boost circuit, leading to high power consumption.

[0027] In order to solve the technical problems in the related art, the embodiment of the present disclosure provides a backlight control circuit of a screen, including a control circuit, a boost circuit, a backlight circuit, a constant current source circuit and a screen, wherein the control circuit is respectively connected to the boost circuit, the screen and the constant current source circuit, and the backlight circuit is respectively connected to the boost circuit, the screen and the constant current source circuit, wherein the boost circuit can output voltage to supply power to the backlight circuit, the constant current source circuit can control the current of the backlight circuit to be constant, thereby improving the stability of the screen display, and the control circuit can control the light-emitting elements in the backlight circuit to light up or go out through the screen, and the control circuit can control the boost circuit according to the voltage of the constant current source circuit. According to the above-mentioned backlight control circuit, since the voltage difference between the constant current source circuit and the backlight circuit is stable, the control circuit can sample the voltage across the constant current source circuit. When the voltage of the constant current source circuit is small, the boost circuit can be controlled to boost the voltage for a longer period of time. When the voltage of the constant current source circuit is large, the boost circuit can be controlled to reduce the voltage for a period of time. In this way, the boost circuit can be guaranteed to work continuously, the working efficiency of the boost circuit is high, and thus the power consumption is reduced. In addition, the constant current source circuit can ensure the current stability of the backlight circuit, avoid large ripples, and improve the screen display effect.

[0028] The following detailed description of the technical solution of the present disclosure and how the technical solution of the present disclosure solves the above-mentioned technical problems is provided with specific embodiments. The following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments. The embodiments of the present disclosure will be described below in conjunction with the accompanying drawings.

[0029] Figure 2 is a schematic diagram of the structure of a backlight control circuit provided by an embodiment of the present disclosure. Referring to Figure 2 , the backlight control circuit includes a control circuit, a boost circuit, a screen, a backlight circuit, and a constant current source circuit. The control circuit is connected to the boost circuit, the screen, and the constant current source circuit, respectively; and the backlight circuit is connected to the boost circuit, the screen, and the constant current source circuit, respectively.

[0030] The control circuit is used to control the lighting or extinguishing of the light-emitting element in the backlight circuit through the screen, and to control the boost circuit according to the voltage of the constant current source circuit. For example, the light-emitting element can be a light bulb, or any other device that can emit light, which is not limited in the embodiments of the present disclosure. For example, the control circuit can sample the voltage of the constant current source circuit and send a PWM signal to the boost circuit based on the voltage of the constant current source circuit. The boost circuit can operate according to the PWM signal to boost the backlight circuit.

[0031] For example, if the voltage of the constant current source circuit sampled by the control circuit is relatively small, the control circuit can generate a related PWM signal with a relatively large duty cycle in the PWM signal, and the boost circuit can increase the voltage of the backlight circuit based on the PWM signal; if the voltage of the constant current source circuit sampled by the control circuit is relatively large, the control circuit can generate a related PWM signal with a relatively small duty cycle in the PWM signal, and the boost circuit can reduce the voltage of the backlight circuit based on the PWM signal.

[0032] For example, the control circuit can send lighting control information to the screen for controlling the on / off of light-emitting elements. The screen can then control the light-emitting elements in the backlight circuit to light up or off based on the lighting control information. For example, the lighting control information sent by the control circuit to the screen can be: light up the light-emitting element at time A and turn off the light-emitting element at time B. Then, based on the lighting control information, the screen can control the light-emitting elements in the backlight circuit to light up at time A and turn off at time B.

[0033] The screen may be a screen in a VR device, and the backlight circuit may be provided in the screen. Optionally, the backlight circuit may include multiple light-emitting elements. For example, the backlight circuit may include multiple light-emitting elements of any material, and the multiple light-emitting elements may be periodically turned on and off. The longer the light-emitting elements are on during the period, the brighter the screen brightness, and the longer the light-emitting elements are off during the period, the dimmer the screen brightness.

[0034] It should be noted that the working period of the light emitting element can be of any duration (eg, 0.1 seconds, 0.2 seconds, etc.), and the embodiments of the present disclosure do not limit this.

[0035] The boost circuit is used to output a voltage to power the backlight circuit. For example, the boost circuit can be a boost circuit that can boost the input voltage to output a higher voltage. For example, if the input voltage of the boost circuit is 10V, the output voltage of the boost circuit can be 20V.

[0036] It should be noted that the above-mentioned boost circuit is only an example of a boost circuit and is not a limitation of the boost circuit in the embodiment of the present disclosure. The boost circuit in the embodiment of the present disclosure can be any circuit with a boost function, and the embodiment of the present disclosure does not limit this.

[0037] The constant current source circuit is used to control the current in the backlight circuit. For example, the backlight control circuit of a screen based on the constant current source circuit can ensure the current in the backlight circuit is constant, thereby reducing the current ripple, avoiding damage to the light-emitting elements in the backlight circuit, and extending the service life of the light-emitting elements in the backlight circuit.

[0038] It should be noted that the constant current source circuit in the embodiment of the present disclosure may also be grounded. The constant current source circuit in the embodiment of the present disclosure may be any circuit with a current stabilization function. The embodiment of the present disclosure does not limit the structure of the constant current source circuit.

[0039] It should be noted that the backlight control circuit of the screen in the embodiment of the present disclosure may also include a power supply, wherein the connection relationship between the power supply and the components in the backlight control circuit of the screen is not limited in the embodiment of the present disclosure.

[0040] The disclosed embodiments provide a backlight control circuit, comprising a control circuit, a boost circuit, a backlight circuit, a constant current source circuit, and a screen. The control circuit can send lighting control information to the screen, and the screen can control the lighting or extinguishing of the light-emitting elements in the backlight circuit based on the lighting control information. Furthermore, the control circuit can sample the voltage across the constant current source circuit and, based on the voltage of the constant current source circuit, send a PWM signal to the boost circuit to cause the boost circuit to operate based on the PWM signal. In this way, the boost circuit in the backlight control circuit can operate continuously, with high operating efficiency. Furthermore, the constant current source circuit can ensure current stability in the backlight circuit, preventing damage to the light-emitting elements in the backlight circuit. Furthermore, the voltage across the constant current source circuit is highly stable, and the control circuit controls the boost circuit based on the voltage of the constant current source circuit, thereby improving the accuracy of the boost circuit's operation.

[0041] Based on the embodiment shown in FIG2 , the control circuit includes a system-on-chip (SOC) and an MCU. The structure of the backlight control circuit will be further described below in conjunction with FIG3 .

[0042] FIG3 is a schematic diagram of the structure of another backlight control circuit provided by an embodiment of the present disclosure. Based on the embodiment shown in FIG2 , please refer to FIG3 . The control circuit includes a system-on-chip (SOC) and an MCU, wherein the SOC is connected to the MCU and the screen, respectively, and the MCU is also connected to the boost circuit and the constant current source circuit. The SOC can be used to control or extinguish the light-emitting element circuit in the backlight circuit through the screen, and the SOC is also used to send a backlight synchronization signal to the MCU. The MCU is used to generate a pulse width modulation signal and control the boost circuit based on the pulse width modulation signal.

[0043] Optionally, the backlight synchronization signal can be used to indicate the voltage sampling time. For example, the backlight synchronization signal can synchronize the time when the MCU performs voltage sampling. The backlight synchronization signal can include multiple signals for indicating the time of voltage sampling. The MCU can sample the voltage of the constant current source circuit at the associated time based on the signals.

[0044] Optionally, the SOC can determine the backlight synchronization signal based on the interrupt signal of the light-emitting element in the screen and send the backlight synchronization signal to the MCU. For example, in actual application, after the light-emitting element in the backlight circuit is lit, the voltage will continue to drop, and after the light-emitting element is turned off, the voltage will rise. Therefore, the backlight synchronization signal generated by the SOC can instruct the MCU to sample the voltage at the moment the light-emitting element is turned off (that is, sample the lowest point of the voltage of the constant current source circuit, and the MCU can determine the sampling time of the lowest voltage point based on the backlight synchronization signal).

[0045] Next, the voltage of the constant current source circuit will be described with reference to FIG. 4 .

[0046] Figure 4 is a voltage schematic diagram of a constant current source circuit provided in an embodiment of the present disclosure. Please refer to Figure 4, which includes: a coordinate system. The vertical axis of the coordinate system is voltage, the horizontal axis of the coordinate system is time, and the coordinate system includes a line showing the voltage of the constant current source circuit changing with time. In the stage from point A to point B, the light-emitting element in the backlight circuit is turned on, and the voltage of the constant current source circuit decreases. In the stage after point B, the light-emitting element in the backlight circuit is turned off, and the voltage of the constant current source circuit increases. In an embodiment of the present disclosure, the MCU can perform voltage sampling at the moment when the backlight is turned off at point B based on the backlight synchronization signal, and then sample the minimum voltage of the constant current source circuit. The operation of the boost circuit is controlled based on the voltage, which can ensure that the light-emitting element is turned on and improve the working efficiency of the boost circuit.

[0047] Optionally, when the SOC controls the light-emitting element circuit in the backlight circuit through the screen to turn it on or off, the SOC is specifically used to send light control information to the screen, and the screen is specifically used to generate a backlight pulse width modulation signal according to the light control information, and send the backlight pulse width modulation signal to the backlight circuit, so that the backlight circuit turns on the light-emitting element or turns off the light-emitting element according to the backlight pulse width modulation signal.

[0048] The backlight pulse-width modulation signal can be used to control the lighting of light-emitting elements. For example, the backlight circuit turns on the light-emitting elements when the backlight PWM signal is at a high level and turns off the light-emitting elements when the backlight PWM signal is at a low level. For example, in actual applications, the light-emitting elements of the backlight circuit can be controlled by a display. Therefore, after the display receives the lighting control information, it can generate a corresponding backlight PWM signal to turn the light-emitting elements in the backlight circuit on and off based on the lighting control information.

[0049] Optionally, the backlight control circuit further includes an analog-to-digital converter (ADC), wherein the ADC is connected to the MCU and the constant current source circuit respectively, and is used to sample the voltage of the constant current source circuit and send the voltage of the constant current source circuit to the MCU.

[0050] The structure of the backlight control circuit will be described below with reference to FIG. 5 .

[0051] FIG5 is a schematic diagram of the structure of another backlight control circuit provided by an embodiment of the present disclosure. Please refer to FIG5 , which includes: an SOC, an MCU, a boost circuit, a screen, a backlight circuit, a constant current source circuit, and an ADC. The backlight circuit is connected to the screen, the constant current source circuit, and the boost circuit, respectively; the MCU is connected to the SOC, the boost circuit, and the ADC, respectively; the ADC is also connected to the constant current source circuit; and the SOC is also connected to the screen. The ADC can be used to sample the voltage of the constant current source circuit and send the voltage of the constant current source circuit to the MCU. In this way, the MCU can control the boost circuit based on the voltage of the constant current source circuit to improve the boost accuracy of the boost circuit.

[0052] Optionally, the MCU is specifically used to: determine the voltage sampling time according to the backlight synchronization signal, control the ADC to collect the voltage of the constant current source circuit at the voltage sampling time, and generate a first pulse width modulation signal according to the voltage of the constant current source circuit, and send the first pulse width modulation signal to the boost circuit so that the boost circuit operates according to the first pulse width modulation signal.

[0053] Optionally, the voltage sampling time may be the time corresponding to the lowest voltage of the constant current source circuit. For example, to ensure the brightness of the screen, the light-emitting element can be normally lit when the voltage across the light-emitting element is at its lowest (i.e., after the light-emitting element is lit, the voltage drops, and the light-emitting element can still operate normally when the voltage across the light-emitting element is at its lowest). Therefore, the voltage sampling time may be the time corresponding to the lowest voltage of the constant current source circuit.

[0054] The first pulse-width modulation signal can control the operation of the boost circuit. Optionally, the MCU generates the first pulse-width modulation signal based on the voltage of the constant current source circuit. Specifically, the MCU can determine a target difference between the voltage of the constant current source circuit and the minimum operating voltage of the constant current source circuit, and determine the first pulse-width modulation signal based on the corresponding relationship between the target difference and the pulse-width modulation signal.

[0055] The minimum operating voltage of the constant current source circuit can indicate whether the light-emitting element is functioning properly. For example, if the voltage of the constant current source circuit is less than the minimum operating voltage of the constant current source circuit, the light-emitting element in the backlight control circuit cannot be illuminated. If the voltage of the constant current source circuit is greater than or equal to the minimum operating voltage of the constant current source circuit, the light-emitting element in the backlight control circuit can be illuminated normally.

[0056] It should be noted that the minimum operating voltage of the constant current source circuit may be a preset voltage value, or a voltage value set based on any other feasible method, and the embodiments of the present disclosure are not limited thereto.

[0057] The target difference may be the difference between the voltage of the constant current source circuit and the minimum operating voltage of the constant current source circuit. For example, if the output voltage is 21V, the number of light-emitting elements is 3, the voltage of each light-emitting element is 6V, and the minimum operating voltage of the constant current source circuit is 2V, then after the output voltage passes through the voltage drop of the three light-emitting elements, the voltage of the constant current source circuit is 3V. Therefore, the target difference between the voltage of the constant current source circuit and the minimum operating voltage of the constant current source circuit is 1V, which indicates that the output voltage is relatively large.

[0058] Optionally, the correspondence between the target difference and the pulse width modulation signal may include multiple differences and the pulse width modulation signal corresponding to each difference. For example, the correspondence between the target difference and the pulse width modulation signal may be as shown in Table 1:

[0059] Table 1

[0060] It should be noted that Table 1 is only an example of the corresponding relationship between the target difference and the pulse width modulation signal, and does not limit the corresponding relationship between the target difference and the pulse width modulation signal.

[0061] For example, if the target difference between the voltage of the constant current source circuit and the minimum operating voltage of the constant current source circuit is difference 1, the first pulse width modulation signal is pulse width modulation signal 1; if the target difference between the voltage of the constant current source circuit and the minimum operating voltage of the constant current source circuit is difference 2, the first pulse width modulation signal is pulse width modulation signal 2; if the target difference between the voltage of the constant current source circuit and the minimum operating voltage of the constant current source circuit is difference 3, the first pulse width modulation signal is pulse width modulation signal 3.

[0062] The MCU can generate a first pulse-width modulation signal based on the voltage of the constant current source circuit and send the first pulse-width modulation signal to the boost circuit, so that the boost circuit operates according to the first pulse-width modulation signal. For example, after determining the voltage of the constant current source circuit, the MCU can generate a first PWM signal (with a pulse width corresponding to the target difference) based on the target difference between the voltage and the minimum operating voltage of the constant current source circuit, and then send the first PWM signal to the boost circuit. After receiving the first PWM signal, the boost circuit can operate based on the first PWM signal. In this way, when the voltage of the constant current source circuit is greater than the minimum operating voltage of the constant current source circuit, it indicates that the voltage output by the boost circuit is relatively high. The first PWM signal can control the boost circuit to reduce the voltage for a period of time. When the voltage of the constant current source circuit is less than the minimum operating voltage of the constant current source circuit, it indicates that the voltage output by the boost circuit is relatively low and cannot maintain the normal operation of the light-emitting element. Therefore, the first PWM signal can control the boost circuit to increase the voltage for a longer period of time, thereby ensuring the normal operation of the light-emitting element.

[0063] It should be noted that, in the embodiment shown in FIG5 , since the MCU can accurately sample the voltage of the constant current source circuit based on the ADC, when the MCU generates the first pulse width modulation signal, the modulation basis is: increasing the voltage of the constant current source circuit so that the sampled voltage of the constant current source circuit is greater than or equal to the minimum operating voltage of the constant current source circuit. In this way, the normal operation of the light-emitting element in the backlight circuit can be guaranteed.

[0064] Next, the working process of the backlight control circuit in the embodiment shown in FIG. 5 will be described with reference to FIG. 6 .

[0065] Figure 6 is a schematic diagram illustrating the operation of a backlight control circuit according to an embodiment of the present disclosure. Referring to Figure 6 , the circuit includes a system-on-chip (SOC), an MCU, a display, a boost circuit, a backlight circuit, a constant current source circuit, and an ADC. The SOC can send lighting control information to the display. The SOC can also send a backlight synchronization signal to the MCU. Based on this signal, the MCU determines the voltage sampling time and controls the ADC to sample the voltage of the constant current source circuit.

[0066] As shown in Figure 6, the screen can generate a backlight pulse-width modulation signal based on the lighting control information and send the backlight pulse-width modulation signal to the backlight circuit, thereby turning the light-emitting elements in the backlight circuit on and off according to the lighting control information. After receiving the voltage from the constant current source circuit, the MCU can determine the output voltage of the boost circuit based on this voltage. It can then generate a first pulse-width modulation signal based on the voltage of the constant current source circuit and send the first pulse-width modulation signal to the boost circuit.

[0067] Please refer to Figure 6. The boost circuit can operate based on the first pulse width modulation signal and output a voltage to the backlight circuit. The constant current source circuit can stabilize the current in the backlight circuit. The light-emitting element in the backlight circuit can operate based on the backlight pulse width modulation signal. The voltage of the light-emitting element in the backlight circuit is provided by the boost circuit, and the boost circuit is controlled by the first pulse width modulation signal output by the MCU. In this way, the MCU can regulate the boost circuit in real time based on the voltage of the constant current source circuit. Since the voltage at both ends of the constant current source circuit is less affected by environmental factors such as temperature, the voltage at both ends of the constant current source circuit is more stable. The MCU can accurately control the boost circuit based on the voltage of the constant current source circuit, thereby improving the control accuracy of the boost circuit and reducing the power consumption of the circuit.

[0068] The present disclosure provides a backlight control circuit for a screen, comprising a system-on-chip (SOC) and an MCU, as well as a boost circuit, a backlight circuit, a constant current source circuit, a screen, and an ADC. The SOC can send lighting control information to the screen, which can generate a backlight PWM signal based on the lighting control information to cause the backlight circuit to illuminate or extinguish light-emitting elements based on the backlight PWM signal. The SOC can send a backlight synchronization signal to the MCU, which can determine a voltage sampling time based on the backlight synchronization signal, and based on the voltage sampling time and the ADC, sample the voltage of the constant current source circuit, thereby controlling the boost circuit based on the voltage of the constant current source circuit. In this way, when the voltage of the constant current source circuit is small, the MCU can control the boost circuit to boost the voltage. When the voltage of the constant current source circuit is large, the MCU can control the boost circuit to reduce the voltage for a period of time. In this way, the light-emitting elements in the backlight circuit can be normally lit, and the display effect of the screen can be improved. In addition, the boost circuit can work continuously, improve the working efficiency of the boost circuit, and reduce the power consumption of the circuit. In addition, the voltage stability at both ends of the constant current source circuit is high, which can improve the accuracy of the control of the boost circuit.

[0069] Based on any of the above embodiments, the backlight control circuit further includes a comparator, wherein the comparator can replace the ADC in the backlight control circuit. The structure of the above backlight control circuit is described below with reference to FIG. 7 .

[0070] FIG7 is a schematic diagram of the structure of another backlight control circuit provided by an embodiment of the present disclosure. Please refer to FIG7 , which includes an SOC, an MCU, a boost circuit, a screen, a backlight circuit, a constant current source circuit, and a comparator. The backlight circuit is connected to the screen, the constant current source circuit, and the boost circuit respectively, the MCU is connected to the SOC and the boost circuit respectively, the comparator is connected to the MCU and the constant current source circuit respectively, and the SOC is also connected to the screen. The comparator is used to generate a comparison result based on the minimum operating voltage of the constant current source circuit and the voltage of the constant current source circuit, and send the comparison result to the MCU.

[0071] Optionally, the comparison result may include a high level and a low level. For example, the high level duration and the low level duration in the comparison result may reflect the relationship between the voltage of the constant current source circuit and the minimum operating voltage of the constant current source circuit. After receiving the comparison result, the MCU may determine whether the voltage output by the boost circuit is larger or smaller based on the comparison result, thereby accurately controlling the boost circuit.

[0072] Optionally, when the voltage of the constant current source circuit is less than the minimum operating voltage of the constant current source circuit, the comparison result output by the comparator is a high level; when the voltage of the constant current source circuit is greater than or equal to the minimum operating voltage of the constant current source circuit, the comparison result output by the comparator is a low level. In this way, if the duration of the high level in the comparison result is longer, it means that the voltage of the constant current source circuit is less than the minimum operating voltage of the constant current source circuit for a period of time, and the voltage output by the boost circuit is smaller. If there is no high level in the comparison result, it means that the voltage of the constant current source circuit is greater than the minimum operating voltage of the constant current source circuit for a period of time, and the voltage output by the boost circuit can enable the light-emitting element to operate normally. For example, the duration of one cycle is 1 second. If the voltage of the constant current source circuit is continuously less than the minimum operating voltage of the constant current source circuit within 0.3 seconds, and the voltage of the constant current source circuit is greater than or equal to the minimum operating voltage of the constant current source circuit within 0.7 seconds, then the high level duration in the comparison result is 0.3 seconds, and the low level duration is 0.7 seconds.

[0073] The comparison results are described below with reference to FIG8 .

[0074] Figure 8 is a schematic diagram of a comparison result provided by an embodiment of the present disclosure. Please refer to Figure 8, including a coordinate system. Among them, the horizontal axis of the coordinate system is time, and the vertical axis of the coordinate system is voltage. The coordinate system includes the relationship between the voltage and time of the constant current source circuit, and the relationship between the comparison result output by the comparator and time. The voltage of the constant current source circuit is less than the minimum operating voltage of the constant current source circuit between point A and point B, that is, the output of the comparator is a high level during the period between the moment of point A and the moment of point B (the light-emitting element cannot work normally during this period), and in other time periods, the output of the comparator is a low level (the light-emitting element can work normally during this period).

[0075] Optionally, the MCU is specifically configured to: generate a second pulse width modulation signal based on the comparison result, and control the boost circuit based on the second pulse width modulation signal. The second pulse width modulation signal can control the operation of the boost circuit. For example, based on the comparison result output by the comparator, the MCU can determine the difference between the voltage of the constant current source circuit and the minimum operating voltage of the constant current source circuit over a period of time. When the voltage of the constant current source circuit is less than the minimum operating voltage of the constant current source circuit, the MCU generates a second pulse width modulation signal that can cause the boost circuit to increase the boost voltage. When the voltage of the constant current source circuit is greater than or equal to the minimum operating voltage of the constant current source circuit, the MCU generates a second pulse width modulation signal that can cause the boost circuit to reduce the boost voltage or maintain the boost voltage unchanged.

[0076] Optionally, the MCU generates a second pulse width modulation signal according to the comparison result. There are two feasible implementation methods:

[0077] A possible implementation:

[0078] The duration of the high level in the comparison result is determined, and a second pulse-width modulation signal is generated based on the duration of the high level. For example, because the high level in the comparison result may indicate that the light-emitting element is not functioning properly, the MCU may generate the second pulse-width modulation signal based on the duration of the high level. This can improve the accuracy of the second pulse-width modulation signal, thereby improving the accuracy of control of the boost circuit.

[0079] For example, in the embodiment shown in Figure 8, the high level in the comparison result output by the comparator can indicate that the voltage of the constant current source circuit is less than the minimum operating voltage of the constant current source circuit, and the light-emitting element cannot light up normally. Therefore, the benchmark for the MCU to control the boost circuit is: reducing the duration of the high level in the comparison result of the comparator, that is, shortening the duration between the moment of point A and the moment of point B (such as, shortening the duration to 0). In this way, in Figure 8, the MCU can increase the pulse width length in the second pulse width modulation signal, and then control the boost circuit to boost. After the boost circuit boosts, the voltage of the constant current source circuit will also increase, thereby reducing the duration between point A and point B.

[0080] Optionally, the MCU may obtain a correspondence between the duration of the high level and the pulse width modulation signal, and determine the second pulse width modulation signal based on the duration of the high level and the correspondence. For example, the correspondence between the duration of the high level and the pulse width modulation signal may be as shown in Table 2:

[0081] Table 2

[0082] It should be noted that Table 2 is only an example of the corresponding relationship between the duration of the high level and the pulse width modulation signal, and does not limit the corresponding relationship between the duration of the high level and the pulse width modulation signal.

[0083] For example, if the duration of the high level in the comparison result output by the comparator is duration 1, the second pulse width modulation signal output by the MCU can be pulse width modulation signal 1; if the duration of the high level in the comparison result output by the comparator is duration 2, the second pulse width modulation signal output by the MCU can be pulse width modulation signal 2; if the duration of the high level in the comparison result output by the comparator is duration 3, the second pulse width modulation signal output by the MCU can be pulse width modulation signal 3.

[0084] It should be noted that after the MCU obtains the duration of the high level in the comparison result, it can also generate the second pulse width modulation signal based on any other feasible implementation method, and the embodiment of the present disclosure is not limited to this.

[0085] Another possible implementation:

[0086] Based on the comparison result, a duty cycle is determined, and a second pulse-width modulation signal is generated based on the duty cycle. For example, because the MCU can determine a duty cycle based on the comparison result that can reflect the duration of time during which the light-emitting element fails to operate normally, the MCU can generate the second pulse-width modulation signal based on the duration of the high level. This can improve the accuracy of the second pulse-width modulation signal, thereby improving the accuracy of the control of the boost circuit.

[0087] Optionally, the MCU may obtain a correspondence between the duty cycle and the pulse width modulation signal, and generate a second pulse width modulation signal based on the duty cycle determined by the MCU based on the comparison result and the correspondence. For example, the correspondence between the duty cycle and the pulse width modulation signal may be as shown in Table 3:

[0088] Table 3

[0089] It should be noted that Table 3 is only an example of the corresponding relationship between the duty cycle and the pulse width modulation signal, and does not limit the corresponding relationship between the duty cycle and the pulse width modulation signal.

[0090] For example, if the duty cycle determined by the MCU based on the comparison result is duty cycle 1, the second pulse width modulation signal output by the MCU may be pulse width modulation signal 1; if the duty cycle determined by the MCU based on the comparison result is duty cycle 2, the second pulse width modulation signal output by the MCU may be pulse width modulation signal 2; if the duty cycle determined by the MCU based on the comparison result is duty cycle 3, the second pulse width modulation signal output by the MCU may be pulse width modulation signal 3.

[0091] It should be noted that in the embodiment of the present disclosure, if the voltage output by the boost circuit is large enough so that the light-emitting element can light up normally, then in this scenario, the MCU can control the boost circuit to reduce the output voltage over a period of time in the future until the minimum voltage of the constant current source circuit is equal to the minimum operating voltage of the constant current source circuit. If the voltage output by the boost circuit is small, resulting in the light-emitting element being unable to light up normally during some time periods, then in this scenario, the MCU can control the boost circuit to boost the voltage until the minimum voltage of the constant current source circuit is greater than or equal to the minimum operating voltage of the constant current source circuit.

[0092] 9 , the relationship between the comparison result output by the comparator and the control of the boost circuit will be described.

[0093] FIG9 is a schematic diagram of the relationship between a boost circuit and a comparator provided in an embodiment of the present disclosure. Please refer to FIG9 , which includes a coordinate system. The vertical axis of the coordinate system is voltage, and the horizontal axis of the coordinate system is time. The coordinate system includes the relationship between the voltage and time of the constant current source circuit, and the relationship between the comparison result output by the comparator and time. Between point A and point B, the voltage of the constant current source circuit is less than the minimum operating voltage of the constant current source circuit. Between the moment corresponding to point A and the moment corresponding to point B, the light-emitting element cannot light up normally. The comparator is at a high level during the period between the moment corresponding to point A and the moment corresponding to point B, and is at a low level during other periods.

[0094] Please refer to Figure 9. The comparator can feed back the comparison result of the comparator output to the MCU (not shown in Figure 9). The MCU can determine that the boost circuit (not shown in Figure 9) is insufficiently boosted based on the comparison result. Therefore, the MCU can increase the pulse width length of the second pulse width modulation signal, thereby enabling the boost circuit to operate based on the second pulse width modulation signal. The boost circuit boosts the voltage, and the voltage of the constant current source circuit will increase.

[0095] Please refer to Figure 9. After the voltage of the constant current source circuit increases, the distance between point A and point B will continue to decrease, and the proportion of high levels in the comparison result output by the comparator will also continue to decrease, until the voltage of the constant current source circuit is greater than the minimum operating voltage of the constant current source circuit. The light-emitting element can light up normally at the voltage output by the boost circuit, and the comparison result output by the comparator is a low level.

[0096] Next, the working process of the backlight control circuit in the embodiment shown in FIG. 8 will be described with reference to FIG. 10 .

[0097] Figure 10 is a schematic diagram illustrating the operation of a backlight control circuit according to an embodiment of the present disclosure. Referring to Figure 10 , the circuit includes a system-on-chip (SOC), an MCU, a display, a boost circuit, a backlight circuit, a constant current source circuit, and a comparator. The SOC can transmit lighting control information to the display. Based on this lighting control information, the display generates a backlight pulse-width modulation (PWM) signal and transmits it to the backlight circuit, causing the light-emitting elements in the backlight circuit to illuminate and extinguish according to the lighting control information.

[0098] As shown in Figure 10, the MCU receives the comparison result from the comparator and, based on the duration of the high level in the comparison result, generates a second pulse-width modulated signal. The second pulse-width modulated signal is then sent to the boost circuit. The boost circuit operates based on the second pulse-width modulated signal, outputting a voltage to the backlight circuit. The constant current source circuit stabilizes the current in the backlight circuit.

[0099] Please refer to Figure 10. The light-emitting elements in the backlight circuit can be turned on and off based on the backlight pulse width modulation signal. The voltage of the light-emitting elements in the backlight circuit is provided by the boost circuit, and the boost circuit is controlled by the second pulse width modulation signal output by the MCU. In this way, the MCU can regulate the boost circuit in real time based on the comparison result output by the comparator, thereby improving the working efficiency and boost accuracy of the boost circuit and reducing the power consumption of the circuit.

[0100] The present disclosure provides a backlight control circuit for a screen, comprising a system-on-chip (SOC) and an MCU, as well as a boost circuit, a backlight circuit, a constant current source circuit, a screen, and a comparator. The SOC can send light control information to the screen, and the screen can generate a backlight PWM signal based on the light control information, so that the backlight circuit can light up or extinguish a light-emitting element based on the backlight PWM signal. The comparator can generate a comparison result based on the minimum operating voltage of the constant current source circuit and the voltage of the constant current source circuit, and send the comparison result to the MCU. The MCU generates a second pulse width modulation signal based on the comparison result, and controls the boost circuit based on the second pulse width modulation signal. Thus, since the comparison result can accurately reflect the relationship between the voltage of the constant current source circuit and the minimum operating voltage of the constant current source circuit, the MCU can accurately determine the second pulse width modulation signal based on the comparison result, thereby improving the accuracy of the boost circuit boosting. Furthermore, the boost circuit can continue to operate, improving the working efficiency of the boost circuit and reducing the power consumption of the circuit.

[0101] Optionally, based on any of the above embodiments, an embodiment of the present disclosure further provides a virtual reality device, wherein the virtual reality device includes a pair of glasses and a backlight control circuit as shown in any of the above embodiments, and the backlight control circuit can be provided in the pair of glasses.

[0102] In a first aspect, in one or more embodiments of the present disclosure, the present disclosure provides a backlight control circuit for a screen, the backlight control circuit for the screen comprising: a control circuit, a boost circuit, a backlight circuit, a constant current source circuit, and a screen, wherein:

[0103] The control circuit is connected to the boost circuit, the screen and the constant current source circuit respectively, and the backlight circuit is connected to the boost circuit, the screen and the constant current source circuit respectively;

[0104] The boost circuit is used to output a voltage to supply power to the backlight circuit, and the constant current source circuit is used to control the current of the backlight circuit to be constant;

[0105] The control circuit is used to control the lighting or extinguishing of the light-emitting elements in the backlight circuit through the screen, and to control the boost circuit according to the voltage of the constant current source circuit.

[0106] According to one or more embodiments of the present disclosure, the control circuit includes a system-on-chip (SOC) and an MCU, wherein:

[0107] The SOC is connected to the MCU and the screen respectively, and the MCU is also connected to the boost circuit and the constant current source circuit;

[0108] The SOC is used to control the light-emitting elements in the backlight circuit to light up or turn off through the screen;

[0109] The MCU is used to generate a pulse width modulation signal and control the boost circuit based on the pulse width modulation signal.

[0110] According to one or more embodiments of the present disclosure, the backlight control circuit further includes an analog-to-digital converter ADC, wherein:

[0111] The ADC is connected to the MCU and the constant current source circuit respectively;

[0112] The ADC is used to sample the voltage of the constant current source circuit and send the voltage of the constant current source circuit to the MCU;

[0113] The SOC is further configured to send a backlight synchronization signal to the MCU.

[0114] According to one or more embodiments of the present disclosure, the MCU is specifically used for:

[0115] Determining a voltage sampling time according to the backlight synchronization signal;

[0116] At the voltage sampling moment, controlling the ADC to collect the voltage of the constant current source circuit, and generating a first pulse width modulation signal according to the voltage of the constant current source circuit;

[0117] The first pulse width modulation signal is sent to the boost circuit, so that the boost circuit operates according to the first pulse width modulation signal.

[0118] According to one or more embodiments of the present disclosure, the backlight control circuit further includes a comparator, wherein:

[0119] The comparator is connected to the MCU and the constant current source circuit respectively;

[0120] The comparator is used to generate a comparison result according to the minimum operating voltage of the constant current source circuit and the voltage of the constant current source circuit, and send the comparison result to the MCU;

[0121] The MCU is specifically configured to generate a second pulse width modulation signal according to the comparison result, and control the boost circuit based on the second pulse width modulation signal.

[0122] According to one or more embodiments of the present disclosure, when the voltage of the constant current source circuit is less than the minimum operating voltage of the constant current source circuit, the comparison result output by the comparator is a high level; when the voltage of the constant current source circuit is greater than or equal to the minimum operating voltage of the constant current source circuit, the comparison result output by the comparator is a low level.

[0123] According to one or more embodiments of the present disclosure, the MCU is specifically used for:

[0124] Determine the duration of the high level in the comparison result;

[0125] The second pulse width modulation signal is generated based on the duration of the high level.

[0126] According to one or more embodiments of the present disclosure, the MCU is specifically used for:

[0127] determining a duty cycle according to the comparison result;

[0128] The second pulse width modulation signal is generated according to the duty cycle.

[0129] According to one or more embodiments of the present disclosure, the SOC is specifically used to send light control information to the screen, and the light control information is used to control the on and off of the light-emitting elements in the backlight circuit;

[0130] The screen is specifically configured to generate a backlight pulse width modulation signal according to the light control information, and send the backlight pulse width modulation signal to the backlight circuit, so that the backlight circuit lights up or turns off the light-emitting element according to the backlight pulse width modulation signal.

[0131] In a second aspect, according to one or more embodiments of the present disclosure, an embodiment of the present disclosure provides a virtual reality device, which includes a pair of glasses and a backlight control circuit as shown in any one of the above embodiments, wherein the backlight control circuit is arranged in the pair of glasses.

[0132] It should be noted that the modifications of "one" and "multiple" mentioned in the present disclosure are illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, they should be understood as "one or more".

[0133] The above description is merely an illustration of the technical principles employed in the embodiments of the present disclosure. Those skilled in the art should understand that the scope of disclosure involved in the present disclosure is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also encompass other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the above-mentioned disclosed concepts. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this disclosure.

[0134] In addition, although each operation is described in a specific order, this should not be understood as requiring these operations to be performed in the specific order shown or in a sequential order. Under certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although some specific implementation details have been included in the above discussion, these should not be interpreted as limiting the scope of the present disclosure. Some features described in the context of a separate embodiment can also be implemented in a single embodiment in combination. On the contrary, the various features described in the context of a single embodiment can also be implemented in multiple embodiments individually or in any suitable sub-combination mode.

[0135] Although the present disclosure has been described in language specific to structural features and / or methodological logical acts, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are merely example forms of implementing the claims.

Claims

1. A backlight control circuit for a screen, comprising: Control circuit, boost circuit, backlight circuit, constant current source circuit and screen, wherein: The control circuit is connected to the boost circuit, the screen and the constant current source circuit respectively, and the backlight circuit is connected to the boost circuit, the screen and the constant current source circuit respectively; The boost circuit is configured to output a voltage to supply power to the backlight circuit, and the constant current source circuit is configured to control the current of the backlight circuit to be constant; The control circuit is configured to control the lighting or extinguishing of the light emitting element in the backlight circuit through the screen, and to control the boost circuit according to the voltage of the constant current source circuit.

2. The backlight control circuit according to claim 1, wherein: The control circuit includes a system-on-chip (SOC) and an MCU, wherein: The SOC is connected to the MCU and the screen respectively, and the MCU is also connected to the boost circuit and the constant current source circuit; The SOC is configured to control the light emitting element in the backlight circuit to light up or turn off through the screen; The MCU is configured to generate a pulse width modulation signal and control the boost circuit based on the pulse width modulation signal.

3. The backlight control circuit according to claim 2 further comprises an analog-to-digital converter ADC, wherein: The ADC is connected to the MCU and the constant current source circuit respectively; The ADC is configured to sample the voltage of the constant current source circuit and send the voltage of the constant current source circuit to the MCU; The SOC is further configured to send a backlight synchronization signal to the MCU.

4. The backlight control circuit according to claim 3, wherein: The MCU is configured as: Determine a voltage sampling time according to the backlight synchronization signal; At the voltage sampling moment, controlling the ADC to collect the voltage of the constant current source circuit, and generating a first pulse width modulation signal according to the voltage of the constant current source circuit; The first pulse width modulation signal is sent to the boost circuit, so that the boost circuit operates according to the first pulse width modulation signal.

5. The backlight control circuit according to any one of claims 2 to 4, further comprising a comparator, wherein: The comparator is connected to the MCU and the constant current source circuit respectively; The comparator is configured to generate a comparison result according to the minimum operating voltage of the constant current source circuit and the voltage of the constant current source circuit, and send the comparison result to the MCU; The MCU is configured to generate a second pulse width modulation signal according to the comparison result, and control the boost circuit based on the second pulse width modulation signal.

6. The backlight control circuit according to claim 5, wherein: When the voltage of the constant current source circuit is less than the minimum operating voltage of the constant current source circuit, the comparison result output by the comparator is a high level; when the voltage of the constant current source circuit is greater than or equal to the minimum operating voltage of the constant current source circuit, the comparison result output by the comparator is a low level.

7. The backlight control circuit according to claim 6, wherein: The MCU is configured as: Determining the duration of the high level in the comparison result; The second pulse width modulation signal is generated based on the duration of the high level.

8. The backlight control circuit according to claim 5, wherein the MCU is configured as follows: Determining a duty cycle according to the comparison result; The second pulse width modulation signal is generated according to the duty cycle.

9. The backlight control circuit according to any one of claims 2 to 8, wherein: The SOC is configured to send light control information to the screen, wherein the light control information is used to control the on and off of the light emitting element in the backlight circuit; The screen is configured to generate a backlight pulse width modulation signal according to the light control information, and send the backlight pulse width modulation signal to the backlight circuit, so that the backlight circuit lights up or turns off the light-emitting element according to the backlight pulse width modulation signal.

10. A virtual reality device, comprising a pair of glasses and a backlight control circuit according to any one of claims 1 to 9, wherein: The backlight control circuit is arranged in the glasses body.

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