CN114187882A - System and method for adjusting brightness of display screen of projector - Google Patents

System and method for adjusting brightness of display screen of projector Download PDF

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Publication number
CN114187882A
CN114187882A CN202111407216.6A CN202111407216A CN114187882A CN 114187882 A CN114187882 A CN 114187882A CN 202111407216 A CN202111407216 A CN 202111407216A CN 114187882 A CN114187882 A CN 114187882A
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brightness
module
average power
adjusting
switch module
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CN202111407216.6A
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余锋
金凌琳
曾瑶
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Dangqu Network Technology Hangzhou Co Ltd
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Dangqu Network Technology Hangzhou Co Ltd
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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G5/00—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators
    • G09G5/10—Intensity circuits
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/14—Details

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  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Theoretical Computer Science (AREA)
  • Controls And Circuits For Display Device (AREA)
  • Transforming Electric Information Into Light Information (AREA)

Abstract

The application relates to a system and a method for regulating the brightness of a display screen of a projector, wherein a main control chip sends a brightness signal to a first switch module, the brightness signal is used for switching on or off the first switch module, the first switch module drives a second switch module to be switched on or off, and under the condition that the second switch module is switched on, a constant current control module supplies power to a brightness regulation module through the second switch module; the main control chip adjusts the conduction time of the second switch module by adjusting the brightness signal, so that the average power of the brightness adjusting module is adjusted, the brightness of the display screen is adjusted according to the average power of the brightness adjusting module, stepless adjustment of the brightness of the display screen is achieved, the problems that the number of gears for adjusting the brightness of the display screen is small, and user experience is poor are solved, and the user can prolong the endurance time of the projector by reducing the average power of the brightness adjusting module.

Description

System and method for adjusting brightness of display screen of projector
Technical Field
The application relates to the technical field of projectors, in particular to a system and a method for adjusting brightness of a display screen of a projector.
Background
The intelligent projector is one of a plurality of intelligent electronic products in recent years, integrates human-computer interaction, multimedia interconnection and network search, and has very wide application in intelligent families and intelligent office scenes. The intelligent projector displays contents such as videos on the display screen, the brightness of the display screen directly influences the viewing experience of users, and the requirements of different users on the brightness of the display screen are different. In the related art, the brightness of the display screen can only be roughly adjusted by adjusting the back plate of the display screen, and the adjusted gears are few, so that the user experience is influenced.
At present, an effective solution is not provided aiming at the problems that the brightness of the display screen is roughly adjusted by adjusting a back plate of the display screen, the number of adjusted gears is small, and the user experience is poor in the related art.
Disclosure of Invention
The embodiment of the application provides a system and a method for adjusting the brightness of a display screen of a projector, which are used for at least solving the problems that the brightness of the display screen is roughly adjusted by adjusting a back plate of the display screen, the number of adjusted gears is small, and the user experience is poor in the related art.
In a first aspect, an embodiment of the present application provides a system for adjusting brightness of a display screen of a projector, where the system includes a dimming control circuit and a main control chip, the dimming control circuit includes a first switch module, a second switch module, a brightness adjustment module and a constant current control module, the first switch module is connected to the main control chip and the second switch module respectively, and the second switch module is connected to the constant current control module and the brightness adjustment module respectively;
the main control chip sends a brightness signal to the first switch module, the brightness signal is used for switching on or switching off the first switch module, the first switch module drives the second switch module to be switched on or switched off, and under the condition that the second switch module is switched on, the constant current control module supplies power to the brightness adjusting module through the second switch module;
the main control chip adjusts the conduction time of the second switch module by adjusting the brightness signal so as to adjust the average power of the brightness adjusting module, and adjusts the brightness of the display screen of the projector according to the average power of the brightness adjusting module, wherein the brightness adjusting module is used for supplying power to the display screen of the projector.
In some embodiments, the dimming control circuit further includes a sampling module, the sampling module is connected between the second switch module and the brightness adjustment module, the main control chip acquires an actual average power of the brightness adjustment module by collecting signal values at two ends of the sampling module, and adjusts the brightness signal according to the actual average power and a target average power.
In some of these embodiments, adjusting the luminance signal according to the actual average power and the target average power comprises:
the main control chip is used for storing a corresponding relation between a brightness signal and a target average power, calculating a difference value between the actual average power and the target average power after the main control chip obtains the target average power corresponding to the current brightness signal, judging whether the difference value is within a preset range, and if not, adjusting the brightness signal according to the difference value.
In some embodiments, the first switch module comprises a first transistor, a first resistor and a sixth resistor;
the first end of the first triode is connected with the main control chip through the first resistor, the third end of the first triode is connected with the first end of the sixth resistor and the second switch module respectively, the second end of the sixth resistor is connected with the power supply, and the second end of the first triode is grounded.
In some embodiments, the first switching module comprises a first switching circuit comprising a first transistor, a first resistor, and a fourth resistor, and a second switching circuit comprising a second transistor and a sixth resistor;
the first end of first triode passes through first resistance with main control chip connects, the third end of first triode respectively with the first end of fourth resistance with the first end of second triode is connected, the third end of second triode respectively with the first end of sixth resistance with second switch module connects, the second end of fourth resistance with the second end of sixth resistance all connects the power, the second end of first triode with the second end of second triode all connects ground.
In some embodiments, the second switch module includes a PMOS transistor, a gate of the PMOS transistor is connected to the first switch module, a source of the PMOS transistor is connected to the constant current control module, and a drain of the PMOS transistor is connected to the brightness adjustment module.
In some embodiments, the brightness signal is a PWM signal, and the on-time of the second switching module is adjusted by adjusting a duty ratio of the PWM signal.
In some embodiments, the system further includes a storage module, the storage module is connected to the main control chip, and the main control chip stores the current brightness signal update in the storage module.
In a second aspect, the present application provides a method for adjusting brightness of a display screen of a projector, where the method is applied to the above system, and the method includes:
the main control chip receives a brightness adjusting instruction, obtains a target brightness division value according to the brightness adjusting instruction, and adjusts the duty ratio of the PWM signal according to the target brightness division value;
and the dimming control circuit adjusts the brightness of the display screen of the projector according to the duty ratio of the PWM signal.
In some embodiments, after the dimming control circuit adjusts the brightness of the display screen of the projector according to the duty ratio of the PWM signal, the method further includes:
the main control chip acquires target average power corresponding to the target brightness division value according to the corresponding relation between the brightness division value and the average power, wherein the corresponding relation between the brightness division value and the average power is calibrated in advance and stored in the main control chip;
and the main control chip acquires a difference value between the target average power and the actual average power of the brightness adjusting module, judges whether the difference value is within a preset range, and if not, adjusts the duty ratio of the PWM signal until the difference value is within the preset range.
Compared with the related art, the method for adjusting the brightness of the display screen of the projector, provided by the embodiment of the application, includes the steps that a brightness signal is sent to a first switch module through a main control chip, the brightness signal is used for switching on or switching off the first switch module, the first switch module drives a second switch module to be switched on or switched off, and under the condition that the second switch module is switched on, a constant current control module supplies power to a brightness adjusting module through the second switch module; the main control chip adjusts the conduction time of the second switch module by adjusting the brightness signal, so as to adjust the average power of the brightness adjustment module, and adjusts the brightness of the display screen of the projector according to the average power of the brightness adjustment module, wherein the brightness adjustment module is used for supplying power to the display screen of the projector, and controls the conduction or cut-off time of the second switch module by controlling the time when the brightness signal is at a high level or a low level, so as to adjust the power of the brightness adjustment module, thereby realizing stepless adjustment of the brightness of the display screen of the projector, solving the problems of few adjusted gears and poor user experience, and the user can prolong the endurance time of the projector by reducing the average power of the brightness adjustment module.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:
FIG. 1 is a schematic diagram of a system for brightness adjustment of a projector display screen according to an embodiment of the present application;
FIG. 2 is a schematic diagram of a first switch module according to a first embodiment of the present application;
FIG. 3 is a schematic diagram of a first switch module according to a second embodiment of the present application;
FIG. 4 is a schematic diagram of a second switch module according to an embodiment of the present application;
FIG. 5 is a schematic diagram of a sampling module according to an embodiment of the present application;
FIG. 6 is a schematic diagram of another system for brightness adjustment of a projector display screen according to an embodiment of the present application;
fig. 7 is a flowchart of a method for adjusting brightness of a display screen of a projector according to an embodiment of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments provided in the present application without any inventive step are within the scope of protection of the present application. Moreover, it should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another.
Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of ordinary skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments without conflict.
Unless defined otherwise, technical or scientific terms referred to herein shall have the ordinary meaning as understood by those of ordinary skill in the art to which this application belongs. Reference to "a," "an," "the," and similar words throughout this application are not to be construed as limiting in number, and may refer to the singular or the plural. The present application is directed to the use of the terms "including," "comprising," "having," and any variations thereof, which are intended to cover non-exclusive inclusions; for example, a process, method, system, article, or apparatus that comprises a list of steps or modules (elements) is not limited to the listed steps or elements, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. Reference to "connected," "coupled," and the like in this application is not intended to be limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Reference herein to "a plurality" means greater than or equal to two. "and/or" describes an association relationship of associated objects, meaning that three relationships may exist, for example, "A and/or B" may mean: a exists alone, A and B exist simultaneously, and B exists alone. Reference herein to the terms "first," "second," "third," and the like, are merely to distinguish similar objects and do not denote a particular ordering for the objects.
The application provides a system for adjusting the brightness of a projector display screen, and fig. 1 is a schematic diagram of the system for adjusting the brightness of a projector display screen according to an embodiment of the application, as shown in fig. 1, the system includes a dimming control circuit 10 and a main control chip 11, the dimming control circuit 10 includes a first switch module 103, a second switch module 105, a brightness adjusting module 106 and a constant current control module 104, the first switch module 103 is respectively connected with the main control chip 11 and the second switch module 105, and the second switch module 105 is respectively connected with the constant current control module 104 and the brightness adjusting module 106;
because the luminance signal of the main control chip 11 cannot directly drive the second switch module 105, the driving capability of the luminance signal is improved by adding the first switch module 103 for level conversion, the main control chip 11 sends the luminance signal to the first switch module 103, the luminance signal is used for switching on or off the first switch module 103, the first switch module 103 drives the second switch module 105 to be switched on or off, and the constant current control module 104 supplies power to the luminance adjusting module 106 through the second switch module 105 under the condition that the second switch module is switched on;
the brightness signal is a high-level signal or a low-level signal, the main control chip 11 controls the on-off time of the second switch module 105 by controlling the time when the brightness signal is at the high level or the low level, the power of the brightness adjusting module 106 can be adjusted by adjusting the on-off time of the second switch module 105, the brightness adjusting module 106 is used for supplying power to the projector display screen, so the brightness of the projector display screen can be adjusted by adjusting the average power of the brightness adjusting module 106, and the larger the average power of the brightness adjusting module 106 is, the brighter the display screen is, and the stepless adjustment of the average power of the brightness adjusting module 106 can be achieved, so the stepless adjustment of the brightness of the display screen can be achieved.
In the related art, the brightness of the display screen is roughly adjusted by adjusting the back plate of the display screen, the adjusted gears are few, and the user experience is poor, and in the related art, the power of a module for supplying power to the projector is always the maximum value, so that the power loss is large, and the endurance of the projector is short.
The Pulse Width Modulation (PWM) signal is equivalent to a required waveform by modulating the Width of a series of pulses, and the duty ratio of the PWM signal refers to the percentage of the time that the signal is at a high level in a period of the signal period, so in some embodiments, the luminance signal may be the PWM signal, and the time that the luminance signal is at the high level may be adjusted by adjusting the duty ratio of the PWM signal, so as to adjust the on-time of the second switching module 105.
The transistor operates in the cut-off region and the saturation region, which is equivalent to the turn-off and turn-on of the circuit, so in some embodiments, the first switching module 103 may be a circuit in which the transistor serves as a switch, fig. 2 is a schematic diagram of the first switching module according to the first embodiment of the present application, as shown in fig. 2, the first transistor Q1 is an NPN transistor, and the first switching module 103 includes an NPN transistor Q1, a first resistor R1, and a sixth resistor R6;
a base electrode of the NPN triode Q1 is connected to the main control chip 11 through the first resistor R1, a PWM pin of the main control chip 11 is protected from high voltage impact through the first resistor R1, an emitter electrode of the NPN triode Q1 is connected to the first end of the sixth resistor R6 and the second switch module 105, respectively, a second end of the sixth resistor R6 is connected to the power VCC, a collector electrode of the NPN triode Q1 is grounded, if the second switch module 105 is turned on at a low level, when a PWM signal is at a high level, the NPN triode Q1 is turned on, at this time, a collector electrode of the NPN triode Q1 is at a low level, the second switch module 105 is turned on, and the constant current control module 104 supplies power to the brightness adjustment module 106 through the second switch module 105; when the PWM signal is at a low level, the NPN transistor Q1 is turned off, and at this time, the collector of the NPN transistor Q1 is at a high level, and the second switch module 105 is turned off, and the average power of the luminance adjusting module 106 can be adjusted by controlling the on-time of the second switch module 105, thereby adjusting the luminance of the projector display screen.
Optionally, the first transistor Q1 may also be a PNP transistor, but because the characteristics of the PNP transistor and the NPN transistor are different, the PNP transistor alone cannot be used as a switch, but rather, a PNP transistor and an NPN transistor are used as a switch, fig. 3 is a schematic diagram of the first switch module according to the second embodiment of the present application, and as shown in fig. 3, the first switch module 103 includes a first switch circuit and a second switch circuit, the first switch circuit includes a first transistor (i.e., PNP transistor Q1), a first resistor R1, and a fourth resistor R4, and the second switch circuit includes a second NPN transistor (i.e., transistor Q2) and a sixth resistor R6;
the base electrode of the PNP triode Q1 is connected to the main control chip 11 through the first resistor R1, the emitter electrode of the PNP triode Q1 is connected to the first end of the fourth resistor R4 and the base electrode of the NPN triode Q2, the collector electrode of the NPN triode Q2 is connected to the first end of the sixth resistor R6 and the second switch module 105, the second end of the fourth resistor R4 and the second end of the sixth resistor R6 are both connected to the power supply, wherein the power supply VCC may obtain a 3.3V voltage after voltage reduction, and the collector electrode of the PNP triode Q1 and the emitter electrode of the NPN triode Q2 are both grounded.
If the second switch module 105 is turned on at a low level, when the PWM signal is at a high level, the PNP transistor Q1 is turned off, at this time, the emitter of the PNP transistor Q1 is at a high level, the NPN transistor Q2 is turned on, the collector of the NPN transistor Q2 is at a low level, the second switch module 105 is turned on, and the constant current control module 104 supplies power to the brightness adjustment module 106 through the second switch module 105; when the PWM signal is at a low level, the PNP transistor Q1 is turned on, at this time, the emitter of the PNP transistor Q1 is at a low level, the NPN transistor Q2 is turned off, the collector of the NPN transistor Q2 is at a high level, and the second switch module 105 is turned off, and by controlling the on-time of the second switch module 105, the average power of the luminance adjusting module 106 can be adjusted, thereby adjusting the luminance of the display screen of the projector.
Since MOS transistors have high driving capability and are often used as power switches or switches for high current, in some embodiments, the second switch module 105 may be a PMOS transistor as a switch circuit, fig. 4 is a schematic diagram of the second switch module according to the embodiment of the present disclosure, as shown in fig. 4, the second switch module 105 includes a PMOS transistor TR1, a gate of the PMOS transistor TR1 is connected to the first switch module 103, a source of the PMOS transistor TR1 is connected to the constant current control module 104, and a drain of the PMOS transistor TR1 is connected to the brightness adjustment module 106;
if VCC is 14V, the voltage output by the constant current control module 104 is also 14V, when the PWM signal is at a high level, the transistor Q1 is turned on, the collector of the transistor Q1 is at a low level, the PMOS transistor is turned on, and the constant current control module 104 supplies power to the brightness adjustment module 106 through the second switch module 105; when the PWM signal is low, the transistor Q1 is turned off, the collector of the transistor Q1 is high, and the PMOS transistor is turned off.
Optionally, the second switch module 105 may also be a circuit in which an NMOS transistor is used as a switch, but since the conduction conditions of the NMOS transistor and the PMOS transistor are different, the power supply voltage needs to be higher than the voltage output by the constant current control module 104 by a certain value.
The main control chip 11 may further detect an actual average power of the brightness adjusting module 106 at any time, and adjust a duty ratio of the PWM signal to precisely control the power of the brightness adjusting module 106 when the actual average power is not expected, so in some embodiments, the dimming control circuit 10 further includes a sampling module, fig. 5 is a schematic diagram of the sampling module according to the embodiment of the present disclosure, and as shown in fig. 5, the sampling module samples the power of the brightness adjusting module 106The module comprises a sampling resistor R3, the sampling resistor R3 is connected between the second switch module 105 and the brightness adjusting module 106, and the main control chip 11 collects the voltage U at the two ends of the sampling resistor R3NAnd UPThe actual average power of the brightness adjusting module 106 is calculated, if the actual average power is smaller than the target average power, the duty ratio of the PWM signal is increased, and if the actual average power is larger than the target average power, the duty ratio of the PWM signal is decreased until the actual average power is equal to the target average power or the difference value is within the preset range.
The actual average power P of the brightness adjustment module 106 is calculated as shown in the following equations 1 and 2:
equation 1:
Figure BDA0003373161950000071
equation 2:
Figure BDA0003373161950000072
wherein D is the duty ratio of the PWM signal,
Figure BDA0003373161950000073
Ponis the power when the PMOS tube is conducted, PoffThe value is 0, the power of the PMOS tube when the PMOS tube is cut off is shown, and the larger the duty ratio D of the PWM signal is, the larger the actual average power P is, and the brighter the display screen of the projector is.
Optionally, the corresponding relationship between the duty ratio and the target average power is calibrated in advance and stored in the main control chip 11, after the main control chip 11 calculates the actual average power of the brightness adjusting module 106, the corresponding target average power is obtained according to the current duty ratio, and the difference between the actual average power and the target average power is calculated, if the difference is within a preset range, no adjustment is needed, and if the difference is outside the preset range, the duty ratio is adjusted until the difference between the actual average power and the target average power is within the preset range.
In some embodiments, fig. 6 is a schematic diagram of another system for adjusting brightness of a display screen of a projector according to an embodiment of the present disclosure, and as shown in fig. 6, the system further includes a storage module 61, the storage module 61 is connected to the main control chip 11, and the main control chip 11 updates and stores a current brightness signal in the storage module 61. In this embodiment, the storage module 61 may be an EMMC chip, and when the luminance signal is a PWM signal, the duty ratio information of the current PWM signal is stored in the EMMC chip, so that the duty ratio information of the PWM signal is not lost even if the system is powered off, and when the user turns on the intelligent projector next time, the screen can automatically recover to the luminance before the shutdown.
The present embodiment provides a method for adjusting brightness of a display screen of a projector, which is applied to the system for adjusting brightness of a display screen of a projector described in the foregoing embodiment, and fig. 7 is a flowchart of a method for adjusting brightness of a display screen of a projector according to an embodiment of the present application, and as shown in fig. 7, the method includes the following steps:
step S701, the main control chip 11 receives a brightness adjusting instruction, obtains a target brightness division value according to the brightness adjusting instruction, and adjusts the duty ratio of the PWM signal according to the target brightness division value; in practical application, the system for adjusting the brightness of the projector display screen may further include a UI control interface, a brightness adjustment button is embedded in the UI control interface, a user selects a corresponding button through a remote controller to send a brightness adjustment instruction, the main control chip 11 receives the brightness adjustment instruction to obtain a target brightness division value corresponding to the brightness adjustment instruction, according to a corresponding relationship between the brightness division value and a duty ratio of a PWM signal, a duty ratio of the PWM signal corresponding to the target brightness division value is obtained, and the duty ratio of the PWM signal is adjusted, where the corresponding relationship between the brightness division value and the duty ratio of the PWM signal is stored in the main control chip 11 in advance.
In step S702, the dimming control circuit 10 adjusts the brightness of the projector display screen according to the duty ratio of the PWM signal. In this embodiment, when the duty ratio of the PWM signal is changed, the on-time of the second switch module 105 in the dimming control circuit 10 is also changed, so that the average power of the brightness adjusting module 106 is changed, and the effect of adjusting the brightness of the display screen of the projector is achieved.
Compared with the prior art, the brightness of the display screen is roughly adjusted by adjusting the back plate of the display screen, the adjusted gears are few, and the user experience is poor, in the embodiment, through the steps from S701 to S702, the duty ratio of the PWM signal is adjusted through the brightness adjusting instruction, so that the average power of the brightness adjusting module 106 is adjusted, the higher the average power is, the brighter the projector display screen is, and the effect of the brightness of the projector display screen is achieved, and as the duty ratio of the PWM signal can be steplessly adjusted by 0-100%, the stepless adjustment of 0-100% can be achieved for the brightness of the projector display screen, and the problems of few gears and poor user experience of the brightness adjustment of the projector display screen are solved.
In some embodiments, after the dimming control circuit 10 adjusts the brightness of the display screen of the projector according to the duty ratio of the PWM signal, the main control chip 11 obtains a target average power corresponding to the target brightness division value according to a corresponding relationship between the brightness division value and the average power, where the corresponding relationship between the brightness division value and the average power is calibrated in advance and stored in the main control chip 11;
the main control chip 11 obtains a difference between the target average power and the actual average power of the brightness adjusting module 106, determines whether the difference is within a preset range, and if not, adjusts the duty ratio of the PWM signal until the difference is within the preset range, so that the average power of the brightness adjusting module 106 can be accurately controlled through the embodiment, and the viewing experience of the user is greatly improved.
It should be noted that the steps illustrated in the above-described flow diagrams or in the flow diagrams of the figures may be performed in a computer system, such as a set of computer-executable instructions, and that, although a logical order is illustrated in the flow diagrams, in some cases, the steps illustrated or described may be performed in an order different than here.
The present embodiment also provides an electronic device comprising a memory having a computer program stored therein and a processor configured to execute the computer program to perform the steps of any of the above method embodiments.
Optionally, the electronic apparatus may further include a transmission device and an input/output device, wherein the transmission device is connected to the processor, and the input/output device is connected to the processor.
It should be noted that, for specific examples in this embodiment, reference may be made to examples described in the foregoing embodiments and optional implementations, and details of this embodiment are not described herein again.
In addition, in combination with the method for adjusting the brightness of the display screen of the projector in the foregoing embodiments, the embodiments of the present application may provide a storage medium to implement. The storage medium having stored thereon a computer program; the computer program, when executed by a processor, implements any one of the above-described embodiments of the method for adjusting the brightness of a display screen of a projector.
In one embodiment, a computer device is provided, which may be a terminal. The computer device includes a processor, a memory, a network interface, a display screen, and an input device connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device comprises a nonvolatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of an operating system and computer programs in the non-volatile storage medium. The network interface of the computer device is used for communicating with an external terminal through a network connection. The computer program is executed by a processor to implement a method for adjusting the brightness of a display screen of a projector. The display screen of the computer equipment can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer equipment can be a touch layer covered on the display screen, a key, a track ball or a touch pad arranged on the shell of the computer equipment, an external keyboard, a touch pad or a mouse and the like.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus Direct RAM (RDRAM), direct bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).
It should be understood by those skilled in the art that various features of the above-described embodiments can be combined in any combination, and for the sake of brevity, all possible combinations of features in the above-described embodiments are not described in detail, but rather, all combinations of features which are not inconsistent with each other should be construed as being within the scope of the present disclosure.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A system for adjusting the brightness of a display screen of a projector is characterized by comprising a dimming control circuit and a main control chip, wherein the dimming control circuit comprises a first switch module, a second switch module, a brightness adjusting module and a constant current control module;
the main control chip sends a brightness signal to the first switch module, the brightness signal is used for switching on or switching off the first switch module, the first switch module drives the second switch module to be switched on or switched off, and under the condition that the second switch module is switched on, the constant current control module supplies power to the brightness adjusting module through the second switch module;
the main control chip adjusts the conduction time of the second switch module by adjusting the brightness signal so as to adjust the average power of the brightness adjusting module, and adjusts the brightness of the display screen of the projector according to the average power of the brightness adjusting module, wherein the brightness adjusting module is used for supplying power to the display screen of the projector.
2. The system of claim 1, wherein the dimming control circuit further comprises a sampling module, the sampling module is connected between the second switching module and the brightness adjustment module, the main control chip acquires an actual average power of the brightness adjustment module by collecting signal values at two ends of the sampling module, and adjusts the brightness signal according to the actual average power and a target average power.
3. The system of claim 2, wherein adjusting the luminance signal according to the actual average power and the target average power comprises:
the main control chip is used for storing a corresponding relation between a brightness signal and a target average power, calculating a difference value between the actual average power and the target average power after the main control chip obtains the target average power corresponding to the current brightness signal, judging whether the difference value is within a preset range, and if not, adjusting the brightness signal according to the difference value.
4. The system of claim 1, wherein the first switching module comprises a first transistor, a first resistor, and a sixth resistor;
the first end of the first triode is connected with the main control chip through the first resistor, the third end of the first triode is connected with the first end of the sixth resistor and the second switch module respectively, the second end of the sixth resistor is connected with the power supply, and the second end of the first triode is grounded.
5. The system of claim 1, wherein the first switching module comprises a first switching circuit and a second switching circuit, the first switching circuit comprising a first transistor, a first resistor, and a fourth resistor, the second switching circuit comprising a second transistor and a sixth resistor;
the first end of first triode passes through first resistance with main control chip connects, the third end of first triode respectively with the first end of fourth resistance with the first end of second triode is connected, the third end of second triode respectively with the first end of sixth resistance with second switch module connects, the second end of fourth resistance with the second end of sixth resistance all connects the power, the second end of first triode with the second end of second triode all connects ground.
6. The system of claim 1, wherein the second switch module comprises a PMOS transistor, a gate of the PMOS transistor is connected with the first switch module, a source of the PMOS transistor is connected with the constant current control module, and a drain of the PMOS transistor is connected with the brightness adjustment module.
7. The system of claim 6, wherein the brightness signal is a PWM signal, and the on-time of the second switching module is adjusted by adjusting a duty ratio of the PWM signal.
8. The system according to any one of claims 1 to 7, further comprising a storage module, wherein the storage module is connected to the main control chip, and the main control chip stores the current brightness signal update in the storage module.
9. A method for adjusting brightness of a display screen of a projector, which is applied to the system of any one of claims 1-8, the method comprising:
the main control chip receives a brightness adjusting instruction, obtains a target brightness division value according to the brightness adjusting instruction, and adjusts the duty ratio of the PWM signal according to the target brightness division value;
and the dimming control circuit adjusts the brightness of the display screen of the projector according to the duty ratio of the PWM signal.
10. The method of claim 9, wherein after the dimming control circuit adjusts the brightness of the projector display screen according to the duty cycle of the PWM signal, the method further comprises:
the main control chip acquires target average power corresponding to the target brightness division value according to the corresponding relation between the brightness division value and the average power, wherein the corresponding relation between the brightness division value and the average power is calibrated in advance and stored in the main control chip;
and the main control chip acquires a difference value between the target average power and the actual average power of the brightness adjusting module, judges whether the difference value is within a preset range, and if not, adjusts the duty ratio of the PWM signal until the difference value is within the preset range.
CN202111407216.6A 2021-11-24 2021-11-24 System and method for adjusting brightness of display screen of projector Pending CN114187882A (en)

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Publication number Priority date Publication date Assignee Title
CN1115399A (en) * 1994-03-30 1996-01-24 Lg电子株式会社 Lamp opreation device for a projection type LCD projector
CN101371291A (en) * 2006-02-08 2009-02-18 夏普株式会社 Liquid crystal display device
CN202261957U (en) * 2011-09-15 2012-05-30 四川新力光源有限公司 Light-emitting diode (LED) lighting device
US20130044272A1 (en) * 2011-08-18 2013-02-21 Xinming Gao LED Backlight Driving Method, LED Backlight Driving Circuit and Liquid Crystal Display Device
CN103796399A (en) * 2014-03-07 2014-05-14 广州灿博电子科技有限公司 Undistorted LED PWM luminance control circuit
CN104883776A (en) * 2015-04-28 2015-09-02 丁建华 Double control driving technique for industrial film viewer
CN105022220A (en) * 2015-07-31 2015-11-04 苏州市英富美欣科技有限公司 Backlight brightness adjustment circuit of projector

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1115399A (en) * 1994-03-30 1996-01-24 Lg电子株式会社 Lamp opreation device for a projection type LCD projector
CN101371291A (en) * 2006-02-08 2009-02-18 夏普株式会社 Liquid crystal display device
US20130044272A1 (en) * 2011-08-18 2013-02-21 Xinming Gao LED Backlight Driving Method, LED Backlight Driving Circuit and Liquid Crystal Display Device
CN202261957U (en) * 2011-09-15 2012-05-30 四川新力光源有限公司 Light-emitting diode (LED) lighting device
CN103796399A (en) * 2014-03-07 2014-05-14 广州灿博电子科技有限公司 Undistorted LED PWM luminance control circuit
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Application publication date: 20220315