CN112788815A - Display device and power supply circuit - Google Patents
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Abstract
The application provides a display device and supply circuit, wherein display device includes: a display screen configured to display an image picture; a sound reproducing device configured to play sound; the LED lamp is used for lighting the display screen; a power supply circuit configured to supply power to a load of the display apparatus, the load including at least a display screen, a sound reproducing apparatus, and an LED lamp; a controller configured to transmit a first signal and a second signal to a power supply circuit; the power supply circuit is configured to supply power to the LED lamp according to the first signal and the second signal according to a preset period, and the brightness of the LED lamp is adjusted. The application provides a display device and supply circuit can make display device reduce under the condition of circuit hardware cost when adjusting luminance to LED, can also reach certain light modulation precision.
Description
This application claims priority from a chinese patent application filed on 2019, 11/04, under the name "LED dimmer circuit", at the chinese patent office, application No. 201911067353.2, the entire contents of which are incorporated herein by reference.
Technical Field
The present application relates to the field of electronic technologies, and in particular, to a display device and a power supply circuit.
Background
With the continuous development of electronic technology, more and more functions can be realized by electronic equipment, the working state of some electronic equipment can be indicated by the on and off of the arranged LED lamps and the brightness of the LED lamps, and other electronic equipment can also light the display screen of the electronic equipment through the LED lamps. In electronic equipment such as a television and the like, the electronic equipment further comprises an LED lamp controller, for example, when the electronic equipment main controller determines that the brightness of the LED lamp needs to be adjusted, the electronic equipment main controller can send a brightness control signal to the LED lamp controller, and the LED lamp controller can adjust the brightness of the LED lamp according to the brightness control signal.
In the prior art, an analog dimming mode or a digital dimming mode can be adopted when a display device adjusts the brightness of an LED lamp, but in an analog dimming circuit and a digital dimming circuit which are used for dimming an LED, the problems of insufficient precision or high hardware cost exist respectively, and how to enable the display control box to achieve certain dimming precision under the condition that the hardware cost of the circuit can be reduced when the LED is dimmed are also a technical problem which needs to be solved urgently in the field.
Disclosure of Invention
A first aspect of the present application provides a display device comprising:
a display screen configured to display an image picture;
a sound reproducing device configured to play sound;
an LED lamp for lighting the display screen;
a power supply circuit configured to supply power to a load of the display apparatus, the load including at least the display screen, the sound reproduction apparatus, and the LED lamp;
a controller configured to transmit a first signal and a second signal to the power supply circuit;
the power supply circuit is configured to supply power to the LED lamp according to the first signal and the second signal according to a preset period, and the brightness of the LED lamp is adjusted.
In an embodiment of the first aspect of the present application, the power supply circuit includes: an LED controller and a diode;
the first end of the controller used for sending the first signal is connected with the first end of the LED controller;
the second end of the controller, which is used for sending the second signal, is connected with the anode of the diode, and the cathode of the diode is connected with the first end of the LED controller;
in an embodiment of the first aspect of the present application, the first signal is used to instruct the LED controller to perform analog dimming on the LED lamp;
the second signal is used for switching the LED controller to be in a working state.
In an embodiment of the first aspect of the present application,
the LED controller is specifically configured to disconnect the LED power supply from the LED lamp according to a preset period according to the first signal and the second signal.
In an embodiment of the first aspect of the present application, the controller is configured to send the first signal to the first end of the LED controller according to the preset period from the first end of the controller;
in an embodiment of the first aspect of the present application, the controller is further specifically configured to send the second signal from the second terminal of the controller to the first terminal of the LED controller through the diode according to the preset period.
In an embodiment of the first aspect of the present application, the LED controller is configured to establish a connection between the LED power supply and the LED lamp and perform analog dimming on the LED lamp by controlling the LED power supply when the received first signal and the received second signal are both at a high level;
and when the received first signal is at a low level, disconnecting the LED power supply from the LED lamp.
In an embodiment of the first aspect of the present application, the method further includes: a capacitor connected in parallel with the LED lamp;
when the LED controller disconnects the connection relation between the LED power supply and the LED lamp, the capacitor is used for supplying power to the LED lamp through the stored electric energy, and the power-down time of the LED lamp is prolonged.
The second aspect of the present application provides a power supply circuit for adjusting the brightness of an LED lamp in a display device; the display device includes: a controller configured to transmit a first signal and a second signal to the power supply circuit; the LED lamp is used for lightening a display screen of the display device;
the power supply circuit is configured to supply power to the LED lamp according to the first signal and the second signal according to a preset period, and the brightness of the LED lamp is adjusted.
A third aspect of the present application provides a display device comprising:
a first display screen for displaying a first image;
a second display screen for displaying a second image;
a sound reproducing device configured to play sound;
an LED lamp for lighting the display screen;
a power supply circuit configured to supply power to a load of the display apparatus, the load including at least the first display screen, the second display screen, the sound reproduction apparatus, and the LED lamp;
a controller configured to transmit a first signal and a second signal to the power supply circuit;
the power supply circuit is configured to supply power to the LED lamp according to the first signal and the second signal according to a preset period, and the brightness of the LED lamp is adjusted.
In summary, the present application provides a display device and a power supply circuit, wherein the display device includes: a display screen configured to display an image picture; a sound reproducing device configured to play sound; the LED lamp is used for lighting the display screen; a power supply circuit configured to supply power to a load of the display apparatus, the load including at least a display screen, a sound reproducing apparatus, and an LED lamp; a controller configured to transmit a first signal and a second signal to a power supply circuit; the power supply circuit is configured to supply power to the LED lamp according to the first signal and the second signal according to a preset period, and the brightness of the LED lamp is adjusted. The application provides a display device and power supply circuit can make LED dimmer circuit reduce under the condition of circuit hardware cost when adjusting luminance to LED, can also reach certain dimming precision.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.
FIG. 1 is a schematic diagram of a display device with an independent power board;
FIG. 2 is a schematic diagram of the connection relationship between a power panel and a load;
fig. 3 is a schematic diagram of a power supply structure of an LED lamp in the display device provided in the present application;
FIG. 4 is a schematic diagram of an analog dimming circuit;
FIG. 5 is a circuit diagram of one implementation of an analog dimming circuit;
fig. 6 is a schematic structural diagram of a PWM dimming circuit;
FIG. 7 is a circuit diagram of a PWM dimming circuit;
FIG. 8 is a schematic structural diagram of an embodiment of a display device provided in the present application;
FIG. 9 is a schematic structural diagram of the controller provided in the present application when the first signal is not transmitted;
fig. 10 is a schematic structural diagram of another embodiment of a display device provided in the present application;
fig. 11 is a circuit schematic diagram of a display device provided in the present application;
FIG. 12 is a diagram illustrating a state one of the device;
FIG. 13 is a diagram illustrating state two of the device;
fig. 14 is a detailed waveform diagram of the first signal provided in the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
Before formally describing the technical solutions provided by the present application, the following description will be made with reference to the accompanying drawings.
As the demand for obtaining information is continuously increasing, various types of display devices, such as computers, televisions, projectors, and the like, are being developed. The power supply circuit is one of the most important circuit structures in the display device, and the power supply circuit can provide electric energy for the display device, so that the display device can normally operate. Some display devices are provided with independent power panels, and some display devices combine the power panels and the main board into a whole.
Taking a display device provided with an independent power board as an example, a structure of the display device is described, referring to fig. 1, fig. 1 is a schematic structural diagram of the display device provided with the independent power board, and as shown in fig. 1, the display device includes a panel 1, a backlight assembly 2, a main board 3, a power board 4, a rear case 5 and a base 6. Wherein, the panel 1 is used for presenting pictures for users; the backlight assembly 2 is located below the panel 1, usually some optical assemblies, and is used for supplying sufficient light sources with uniform brightness and distribution, so that the panel 1 can normally display images, the backlight assembly 2 further includes a back plate 20, the main board 3 and the power board 4 are arranged on the back plate 20, usually some convex hull structures are formed by punching on the back plate 20, and the main board 3 and the power board 4 are fixed on the convex hulls through screws or hooks; the rear shell 5 is covered on the panel 1 to hide the parts of the display device such as the backlight assembly 2, the main board 3 and the power panel 4, and the like, thereby achieving the effect of beautiful appearance; and a base 6 for supporting the display device.
Further, fig. 2 is a schematic diagram of a connection relationship between the power supply board and a load, and as shown in fig. 2, the power supply board 4 includes an input terminal 41 and an output terminal 42 (a first output terminal 421, a second output terminal 422, and a third output terminal 423 are shown in the figure), where the input terminal 41 is connected to the commercial power, the output terminal 42 is connected to the load, for example, the first output terminal 421 is connected to the display screen, the second output terminal 422 is connected to the sound reproduction device (e.g., a sound box), and the third output terminal 423 is connected to the LED lamp. The power panel 4 needs to convert the ac power into dc power required by the load, and the dc power is usually in different specifications, for example, 18V is required for sound, 12V is required for LED lamp, etc.
In addition, the present application can also be applied to sound and picture synchronization processing of a display device having a dual-system, dual-display-screen structure, that is, a display device having a first controller (first hardware system, a chip), a second controller (second hardware system, N chip), a first display screen, and a second display screen. The display device comprises a first display screen and a second display screen, wherein the first display screen and the second display screen are independent from each other, and a double-hardware control system is adopted between the first display screen and the second display screen. The first display screen and the second display screen may be used to display different image pictures.
More specifically, fig. 3 is a schematic diagram of a power supply structure of an LED lamp in a display device provided in the present application, as shown in fig. 1, the present application may be applied to a display device 1 having an LED lamp 30, where the LED lamp may be used to illuminate a display screen of the display device, and the display device 1 may include: the controller 10, the LED controller 20 and the LED lamp are sequentially connected, and the controller 10 of the display device 1 can adjust the brightness of the LED lamp through the LED controller 20. The controller 10 may be a Central Processing Unit (CPU) in an electronic device, and the LED controller 20 is used to adjust operating parameters such as on and off and brightness of the LED lamp 30. When the controller 10 of the electronic display device determines that the brightness of the LED lamp 30 needs to be adjusted, a brightness control signal, which may also be referred to as a "dimming signal," may be sent to the LED controller 20. Subsequently, the brightness of the LED lamp 30 is adjusted by the LED controller 20 according to the received brightness control signal.
For example, if the display device 1 shown in fig. 3 is a television, the LED lamp may be one LED lamp 30 on the television, and the LED lamp 30 may be composed of a plurality of LED group strings; alternatively, the LED lamp may also be used to illuminate the display screen of a television set. Meanwhile, the controller 10 is a main controller in the television, and when the main controller determines that the brightness of the LED lamp 30 needs to be adjusted according to the current working state of the television, the main controller may send a brightness control signal to the LED controller 20 for controlling the LED lamp 30, so that the LED controller 20 adjusts the brightness of the LED lamp 30.
In the display device 1 shown in fig. 3, the LED controller 20 includes at least the following two specific dimming circuits and corresponding dimming methods for adjusting the brightness of the LED lamp 30.
Firstly, simulating dimming.
Fig. 4 is a schematic diagram of an analog dimming circuit, in the analog dimming structure shown in fig. 4, the LED controller 20 is further connected to an LED power supply 31 for supplying power to the LED lamp 30, and the LED power supply 31 is further grounded through the LED lamp 30. At this time, the LED controller 20 can control the brightness of the LED lamp by controlling the current output from the LED power supply 31 to the LED lamp 30.
More specifically, fig. 5 is a circuit schematic diagram of a specific implementation of the analog dimming circuit, in the specific circuit structure shown in fig. 5, the LED power source is denoted as an LED +, the LED lamp includes n LED group strings connected in series, and a current provided by the LED power source flows through the LED lamp and then flows into the ground point. Meanwhile, the LED controller can collect the current flowing through the LED lamp, so that the current value flowing through the LED lamp can be adjusted, and the brightness of the LED lamp can be controlled.
However, in the analog dimming circuit, a special current sampling resistor needs to be arranged in the LED controller to collect the current flowing through the LED lamp, the resistance value of the current sampling resistor needs to be as small as possible due to the problem of current loss caused by the resistor, and the voltage on the resistor is very low under the low-current condition. The current sampling resistor collects the brightness of the LED lamp when the voltage is low, and the brightness of the LED lamp is easy to be disturbed to cause instability, so that the precision of the analog dimming circuit for adjusting the brightness of the LED lamp is not high. For example, assuming that the brightness of the LED lamp can be quantized to twenty brightness levels between (0-20) and 1, 2 … … 19, 20, when the analog dimming circuit adjusts the brightness of the LED lamp to the 5 th level, the current flowing through the LED lamp is already small, the voltage on the current sampling resistor is also low, and the collected voltage is easily interfered, so that the analog dimming circuit cannot perform finer brightness control on the brightness of the LED lamp at the smaller brightness levels 1-4.
Second, digital dimming (also called Pulse Width Modulation (PWM) dimming) is performed).
Fig. 6 is a schematic structural diagram of a PWM dimming circuit, and in the digital dimming structure shown in fig. 6, a switching tube 34 needs to be specially arranged, and the switching tube 34 may be, for example, a MOS tube. Specifically, the switch tube 34 may be disposed on a circuit between the LED power source 31, the LED lamp 30 and the ground 32, and the LED controller 20 may control whether the LED power source 31 supplies power to the LED lamp 30 by controlling on and off of the switch tube 34. In the dimming structure, it is assumed that the LED power source 31 supplies power to the LED lamp 30 all the time, at this time, the brightness of the LED lamp 30 may reach the maximum, and the LED controller 20 may control the switching tube 34 to be turned on and off at a certain period, for example, once every 1 millisecond, so that the LED lamp is switched between a state of frequent power-on and power-off and light-off within a longer time range, thereby reducing the average current flowing through the LED lamp within the time range and realizing the brightness control of the LED lamp.
More specifically, fig. 7 is a circuit schematic diagram of the PWM dimming circuit, and in the specific circuit structure shown in fig. 7, the LED power supply is denoted as an LED +, the LED lamp includes n LED group strings connected in series, the LED lamp is connected in series with the switching tube V1, and the current provided by the LED power supply flows into the grounding point after sequentially flowing through the LED lamp and the switching tube V1. At this moment, the LED controller can be turned on and off according to a preset period by controlling the switching tube V1, and the frequency of turning on and off can determine the average current value flowing through the LED lamp, thereby realizing the control of the brightness of the LED lamp.
However, in the digital dimming circuit, a special switching tube needs to be arranged on a power supply circuit of the LED lamp, and the improvement of the dimming accuracy of the LED lamp is realized through different on and off frequencies of the switching tube, but since each dimming circuit needs to be provided with one switching tube, the complexity of the whole dimming circuit is increased, the manufacturing cost and the maintenance cost of the dimming circuit are increased, and the digital dimming circuit is unacceptable for manufacturers of electronic equipment in actual industrial batch production.
In summary, the above-mentioned problems of the conventional analog dimming circuit and the conventional digital dimming circuit for dimming the LED include insufficient accuracy and high hardware cost, and how to make the LED dimming circuit achieve a certain dimming accuracy while reducing the circuit hardware cost when dimming the LED is a technical problem to be solved in the art.
Therefore, the application provides a display device and a power supply circuit for the power supply circuit can also reach certain dimming precision of dimming to the LED lamp under the condition of reducing cost. The technical solution of the present application will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.
Fig. 8 is a schematic structural diagram of an embodiment of a display device provided in the present application, and the display device 1 shown in fig. 8 includes: controller 10, power supply circuit and LED lamp 30. In the power supply circuit, the LED controller 20 is used to control the LED power source 31 to supply power to the LED lamp 30. Specifically, a first terminal of the controller 10 is connected to a first terminal of the LED controller 20, a second terminal of the LED controller 20 is connected to the LED lamp, and the controller 10 is configured to send a first signal and a second signal to the power supply circuit 20, and specifically configured to supply power to the LED lamp 30 according to the first signal and the second signal according to a preset period to adjust the brightness of the LED lamp. The LED controller 20 may adjust the brightness of the LED lamp 30 in a manner of analog dimming, where the LED lamp 30 may include a plurality of LED assemblies connected in series, and the specific implementation manner of analog dimming may refer to the description in fig. 4 and fig. 5, and is not described herein again. Further, the display device as shown in fig. 8 may further include: a display screen configured to display an image picture; a sound reproduction device configured to play sound or the like, the power supply circuit 20 being further configured to supply power to a load of the display device, the load including at least the display screen, the sound reproduction device, and the LED lamp.
Specifically, the controller 10 may enable the LED controller to adjust the brightness of the LED lamp 30 by analog dimming by sending a first signal to the LED controller 20 through a first terminal thereof, where the first signal may be a high-level signal. Therefore, when the first end of the LED controller 20 receives the high level signal sent by the controller 10, it starts to operate, establishes the connection relationship between the LED power supply 31 and the LED lamp 30, and adjusts the brightness of the LED lamp 30 by analog dimming, and the state can be referred to as fig. 8.
When the first end of the LED controller 20 does not receive the high level signal sent by the controller 10, and the received first signal is a low level signal, or the first end of the LED controller 20 does not receive the first signal (the two indication manners are not limited in this embodiment, and the first end of the LED controller 20 can be set to a low level), the LED controller 20 stops working, and the state of the LED controller 20 can be as shown in fig. 9, where fig. 9 is a schematic structural diagram of the controller provided in this application when the first signal is not sent, where when the controller 10 does not send the first signal to the LED controller 20, the LED controller 20 disconnects the connection relationship between the LED power supply 31 and the LED lamp 30, so that the LED lamp 30 is powered down, and the LED controller 20 also stops adjusting the brightness of the LED lamp 30.
In addition to the controller 10 sending a first signal to the LED controller 20 for indicating dimming, the controller 10 may send a second signal to the LED controller 20 for enabling the LED controller 20, and the second signal may be used for turning on the LED controller 20 so that the LED controller 20 is switched to an operating state and is in a non-operating state when the LED controller 20 does not receive the second signal.
Some LED controllers, due to their pin limitation, typically multiplex the first signal and the second signal sent by the controller 10 on the chip pins, and receive the two signals on the same pin. At this time, for the LED controller 20, it is necessary to ensure that the second signal keeps a high level while receiving the first signal, that is, the second signal is driving the LED controller to be in an on working state, so as to realize the function of turning on the LED controller 20 and performing dimming.
For example, fig. 10 is a schematic structural diagram of another embodiment of the display device provided in the present application, and as shown in fig. 10, the second terminal of the controller 10 is further connected to the first terminal of the LED controller 20, and the controller 10 can simultaneously send the first signal and the second preference to the LED controller 20 through the first terminal and the second terminal thereof. For the LED controller, the LED lamp can be subjected to analog dimming in a preset period within a first time range according to a first signal and a second signal sent by the controller.
Particularly, in this embodiment, the controller 10 may send the first signal to the LED controller 20 according to the preset period, and further improve the dimming precision in a manner of analog "digital dimming" by controlling the LED controller 20 to alternately start and stop working in the preset period, on the basis of obtaining a certain dimming precision by controlling the LED controller 20 to perform analog dimming on the LED lamp.
For example, assuming that the brightness of the LED lamp 30 shown in fig. 8 can be quantized into twenty brightness levels of 1, 2 … … 19, 20 between (0-20), the LED controller 20 adjusts the current output from the LED power supply 31 to the LED lamp 30 by analog dimming, so as to realize the minimum 5 th brightness level to adjust the brightness of the LED lamp. Then, after the controller 10 controls the LED controller 20 to decrease the brightness of the LED lamp 30 to the target value 5, if the brightness of the LED lamp needs to be further decreased to the level 2, the first signal may be sent to the LED controller 20 according to a preset period. For example, the first signal having a length of 1 ms is transmitted every 2 ms within a preset period of 1 second.
The LED controller 20 starts dimming the LED lamp 30 within the above-mentioned 1 second range after receiving the first signal having a length of 1 ms, and the LED rectifying circuit is in the state shown in fig. 6. After 1 ms, the controller 10 stops sending the first signal to the LED controller 20, and the LED controller 20 stops dimming the LED lamp 30 within the interval of 2 ms for the next sending of the first signal, and the LED rectifying circuit is in the state shown in fig. 7.
That is, after the controller 10 sends the first signal to the LED controller 20 at the preset period, the LED controller 20 may be controlled to switch between two states as shown in fig. 6 and 7 at the preset period.
For the LED lamp 30, when the LED controller 20 is in the off state, the current flowing through the LED lamp 30 is rapidly reduced from the 5 th level; when the LED controller 20 is in the operating state, the current flowing through the LED lamp 30 increases toward the 5 th level that can be achieved by the analog dimming; within the time range of 1 second, the average value of the current flowing through the LED lamp is reduced to be smaller than the current Im corresponding to the 5 th-level brightness, for example, the current Iv corresponding to the 2 nd-level brightness, so that the brightness adjustment precision of the LED lamp is increased on the basis of the analog dimming circuit.
Specifically, the reduction to the current value Iv may be implemented by setting different preset periods, and it can be understood that, when the preset period is longer, the current value Iv is smaller, and the preset period is shorter, the current value Iv is larger.
It should be noted that the brightness values described in the above embodiments are only examples, and different LED lamps have different brightness levels, and the preset period needs to be adaptively adjusted to adjust the specific brightness levels of the LED lamps. Moreover, when the controller adjusts the brightness of the same LED lamp, the dimming manner in the present application may be used in some brightness levels (for example, brightness levels of 5 to 20) within the brightness levels (for example, brightness levels of 20) that can be realized by the LED lamp, and may be set according to different situations, which is not limited in the present application.
To sum up, in the display device provided in the embodiment of the present application, the controller sends the first signal indicating the analog dimming to the LED controller in the preset period within the first time range, so that the LED controller switches between two states of performing and not performing the analog dimming on the LED lamp within the first time range, and the average current flowing through the LED lamp within the first time range is reduced, thereby reducing the brightness of the LED lamp.
The display device that this embodiment provided can be on the basis of the precision that LED controller carries out the simulation to the LED lamp and adjust luminance, through the conversion between the start of LED controller and the stop work, the simulation realizes "digital dimming", thereby make the display device based on the simulation adjusts luminance under the condition of not adding new switch tube in power supply circuit, also can obtain higher light modulation precision through the mode similar to digital dimming, enlarge the scope of adjusting luminance, and then solved display device and can't compromise simultaneously and reduce the technical problem that circuit hardware cost can also reach certain light modulation precision.
More specifically, fig. 11 is a circuit schematic diagram of the display device provided in the present application, in which one end of the display device outputting the first signal "BRI" is denoted as a first end of the controller, and one end of the controller outputting the second signal "BL _ ON" is denoted as a second end; meanwhile, in the control circuit of the display device, the "EN/DIM" pin of the LED controller N1 is referred to as a first terminal. The first terminal of the controller is connected to the first terminal of the LED controller N1 through a resistor R1, and the control circuit further comprises: and the second end of the controller is connected with the anode of the diode VD1, and the cathode of the diode VD1 is connected with the first end of the LED controller N1.
Meanwhile, in the circuit shown in fig. 11, the LED power supply is denoted as "Vin", and the LED power supply is connected to n LED group strings connected in series in the LED lamp and then grounded. The 'OUT' pin of the LED controller N1 is connected with a switch tube V1, when a first signal received by the LED controller is a low level signal, the switch tube V1 is controlled to be closed, the LED power supply cannot supply power to the LED lamp, when the first signal and a second signal received by the LED controller are both high level signals, the switch tube V2 is controlled to be disconnected, the LED power supply can supply power to the LED lamp, and therefore the LED lamp is controlled to be turned on and turned off. In addition, the control circuit of the display device further comprises: the capacitor C2 and the LED power supply are grounded through the capacitor C2, the capacitor C2 is connected with the LED lamp in parallel, meanwhile, the capacitor can store electric energy when the LED power supply supplies power to the LED lamp, and after the LED controller disconnects the LED power supply and the LED lamp, the capacitor supplies power to the LED lamp through the stored electric energy, and the power failure time of the LED lamp is prolonged.
In the embodiment shown in fig. 11, the first signal "BRI" and the second signal "BL _ ON" may be high signals sent by the controller, and the first signal and the second signal may act together ON the "EN/DIM" pin of the LED controller N1 to realize the control of the LED controller.
In a first possible specific implementation manner, fig. 12 is a schematic diagram of a state one in the display device, and fig. 12 shows that in a time range from t1 to t6, the controller sends the voltage of the first signal "BRI" and the voltage of the second signal "BL _ ON" to the LED controller N1 according to a preset period, and the current I flowing through the LED lampledThe first correspondence relationship of (1).
In the time range t1-t6, the controller sends a first signal "BRI" with a duration of t1-t2, t3-t4 and t5-t6 to the LED controller N1 according to the same preset period of t2-t3 and t4-t5, as shown in fig. 12, since the first signal "BRI" is a high frequency signal, the first signal may be in the form of a continuous pulse with a high level in the preset period of t1-t2, t3-t4 and t5-t 6. Meanwhile, the controller sends a second signal "BL _ ON" with the duration of t1-t2, t3-t4 and t5-t6 to the LED controller N1 according to the same preset period as the first signal, and the second signal representation shown in FIG. 10 is also high level.
At this time, in the time of t1-t2, t3-t4 and t5-t6, the high level "BRI" output by the controller is transmitted to the "EN/DIM" pin of the LED controller N1, and the high level "BL _ ON" output by the controller is at the positive pole of the diode VD1, so that the high level "BRI" of the negative pole is not pulled down, and the "EN/DIM" pin of the LED controller N1 is guaranteed to be at the high level. Subsequently, under the drive of high level, the LED controller N1 controls to turn off the switch tube V1, so that the LED power Vin supplies power to the LED lamp, and the LED controller N1 performs analog dimming, so that the current I flowing through the LED lampledWith a rising trend. In t2-t3 and t4-t5, the BRI and BL _ ON output by the controller are both low level, and under the driving of the low level, the LED controller N1 controls the switch tube V1 to be closed, the LED power supply is stopped to supply power to the LED lamp, so that the current I flowing through the LED lampledAnd begins to fall. In particular, due to the presence of the capacitor C2, after closing the switching tube V1, the stored electrical energy in the capacitor C2 may power the LED lamp such that the current I flowing through the LED lampledThe current does not immediately drop to zero, but gradually drops to prolong the power-down time of the LED lamp.
Therefore, under the action of the first signal "BRI" and the second signal "BL _ ON" as shown in FIG. 12, the current I of the LED lampledThe waveform diagram of (1) generates reciprocating changes in a time range t1-t6, and converts the current I in the time range t1-t6ledThe average value of (d) is designated Iv. Current I of LED lamp during simulation dimming which can be realized by LED controllerledThe capability of the display device to carry out the LED lamp is further increased compared with ImThe dimming range increases the dimming precision.
In another possible specific implementation manner, fig. 13 is a schematic diagram of the state two in the display device, and fig. 13 shows that the voltage of the first signal "BRI" and the voltage of the second signal "BL _ ON" sent to the LED controller N1 by the controller preset period within the time range of t1-t6, and the current I flowing through the LED lampledThe second correspondence relationship of (1). In the time range t1-t6, the controller sends a first signal "BRI" with the duration of t1-t2, t3-t4 and t5-t6 to the LED controller N1 according to the same preset period of t2-t3 and t4-t5, as shown in fig. 10, since the first signal "BRI" is a high frequency signal, the first signal may be in the form of a continuous pulse with a high level in the preset period of t1-t2, t3-t4 and t5-t 6. Meanwhile, the controller continuously transmits the second signal 'BL _ ON' of high level to the LED controller N1 for a time range of t1-t 6.
At this time, in the time of t1-t2, t3-t4 and t5-t6, the high level "BRI" output by the controller is transmitted to the "EN/DIM" pin of the LED controller N1, and the high level "BL _ ON" output by the controller is at the positive pole of the diode VD1, so that the high level "BRI" of the negative pole is not pulled down, and the "EN/DIM" pin of the LED controller N1 is guaranteed to be at the high level. Subsequently, under the drive of high level, the LED controller N1 controls to turn off the switch tube V1, so that the LED power Vin supplies power to the LED lamp, and the LED controller N1 performs analog dimming, so that the current I flowing through the LED lampledWith a rising trend. And in t2-t3 and t4-t5, "BRI" output by the controller is low level and "BL _ ON" is high level, under the action of diode VD1, the low level "BRI" of the negative electrode is not pulled high, so that the pin "EN/DIM" of the LED controller N1 is low level, under the driving of low level, the LED controller N1 controls to close the switch tube V1, the LED power supply is stopped to supply power to the LED lamp, and the current I flowing through the LED lamp is enabled to be low levelledAnd begins to fall. In particular, due to the presence of the capacitor C2, after closing the switching tube V1, the stored electrical energy in the capacitor C2 may power the LED lamp such that the current I flowing through the LED lampledDoes not drop to zero immediately, but drops gradually to extendAnd power-down time of the LED lamp.
Therefore, under the action of the first signal "BRI" and the second signal "BL _ ON" as shown in FIG. 13, the current I of the LED lampledThe waveform diagram of (1) generates reciprocating changes in a time range t1-t6, and converts the current I in the time range t1-t6ledThe average value of (d) is designated Iv. Current I of LED lamp during simulation dimming which can be realized by LED controllerledCompared with Im, the dimming range of the display device for the LED lamp is further increased, and the dimming precision is increased.
Further, fig. 14 is a detailed waveform diagram of the first signal provided by the present application, and as shown in fig. 14, for example, between times t1-t2 in fig. 12 or fig. 13, in the above time, because the signal frequency of the first signal BRI itself is high, the controller continuously sends square wave signals at equal intervals to the LED controller during the whole time t1-t 2.
Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.
Claims (10)
1. A display device, comprising:
a display screen configured to display an image picture;
a sound reproducing device configured to play sound;
an LED lamp for lighting the display screen;
a power supply circuit configured to supply power to a load of the display apparatus, the load including at least the display screen, the sound reproduction apparatus, and the LED lamp;
a controller configured to transmit a first signal and a second signal to the power supply circuit;
the power supply circuit is configured to supply power to the LED lamp according to the first signal and the second signal according to a preset period, and the brightness of the LED lamp is adjusted.
2. The display device according to claim 1,
the power supply circuit includes: an LED controller and a diode;
the first end of the controller used for sending the first signal is connected with the first end of the LED controller;
the second end of the controller used for sending the second signal is connected with the anode of the diode, and the cathode of the diode is connected with the first end of the LED controller.
3. The display device according to claim 2,
the first signal is used for instructing the LED controller to carry out analog dimming on the LED lamp;
the second signal is used for switching the LED controller to be in a working state.
4. The display device according to claim 3,
the LED controller is specifically configured to disconnect the LED power supply from the LED lamp according to a preset period according to the first signal and the second signal.
5. The display device according to claim 4,
the controller is configured to send the first signal to the first terminal of the LED controller at the preset period from the first terminal of the controller.
6. The display device according to claim 5,
the controller is further specifically configured to send the second signal from the second terminal of the controller to the first terminal of the LED controller through the diode according to the preset period.
7. The method of claim 6,
the LED controller is configured to establish connection between the LED power supply and the LED lamp and perform analog dimming on the LED lamp by controlling the LED power supply when the received first signal and the received second signal are both at a high level;
and when the received first signal is at a low level, disconnecting the LED power supply from the LED lamp.
8. The method of claim 7, further comprising:
a capacitor connected in parallel with the LED lamp;
when the LED controller disconnects the connection relation between the LED power supply and the LED lamp, the capacitor is used for supplying power to the LED lamp through the stored electric energy, and the power-down time of the LED lamp is prolonged.
9. A power supply circuit is used for adjusting the brightness of an LED lamp in a display device; the display device includes: a controller configured to transmit a first signal and a second signal to the power supply circuit; the LED lamp is used for lightening a display screen of the display device;
the power supply circuit is configured to supply power to the LED lamp according to the first signal and the second signal according to a preset period, and adjust the brightness of the LED lamp.
10. A display device, comprising:
a first display screen for displaying a first image;
a second display screen for displaying a second image;
a sound reproducing device configured to play sound;
an LED lamp for lighting the display screen;
a power supply circuit configured to supply power to a load of the display apparatus, the load including at least the first display screen, the second display screen, the sound reproduction apparatus, and the LED lamp;
a controller configured to transmit a first signal and a second signal to the power supply circuit;
the power supply circuit is configured to supply power to the LED lamp according to the first signal and the second signal according to a preset period, and the brightness of the LED lamp is adjusted.
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| CN115657347A (en) * | 2022-10-26 | 2023-01-31 | 锦花电子(镇江)有限公司 | Display screen running state intelligent monitoring system and method based on multivariate information |
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