Backlight source control circuit of Android all-in-one machine

Abstract

The utility model is suitable for the technical field of displays, and provides a backlight source control circuit of an Android all-in-one machine, which comprises a longitudinal LED backlight unit, a transverse LED backlight unit, a sub-control unit, a DC / DC voltage regulating module, a light intensity receptor, a voltage comparator and a backlight control module. The backlight units can be controlled to be switched on and off simultaneously or respectively, and the situation that the service life of a single backlight unit is damaged due to long-time work is avoided. Through the light intensity of the ambient light, when the light intensity is too high, the backlight control module directly controls all the backlight units to be turned off, the situation that light is still emitted at the highest brightness under the condition that enough display brightness cannot be provided is avoided, and then rapid reduction of the service life of the backlight units is avoided. The light intensity sensor of the ambient light is used for directly controlling the voltage regulating unit, the luminance of the backlight source can be controlled based on the ambient light, energy is saved, and the service life of the light source is further prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of displays, and particularly relates to a backlight control circuit for an Android all-in-one machine. Background Technique

[0002] With the continuous development of the economy, Android all-in-one machines are required in more and more scenarios, such as advertising machines, inquiry machines, intelligent bus electronic signs, conference all-in-one machines, and teaching all-in-one machines, etc., which are placed either indoors or outdoors. Especially for those placed outdoors or in an environment with strong indoor light, the display brightness of the backlight panel is often one of the important factors affecting the display effect. The display brightness of a display is determined by the following main factors:

[0003] Firstly, it is the type and maximum brightness of the backlight. The backlight is the main light source of the display. Common backlights include LEDs (Light Emitting Diodes) and fluorescent lamps. The brightness of an LED backlight is usually higher than that of a fluorescent lamp and is more energy-efficient. The brightness of the backlight determines the maximum brightness level of the display.

[0004] Secondly, there are also the control circuit and the power supply. The control circuit and the power supply are responsible for managing the power supply and brightness adjustment of the backlight. They control the brightness level of the backlight by adjusting the current or voltage, as well as the stability and efficiency at different brightness levels. In addition to the display effect, the factor of its service life also needs to be considered.

[0005] However, in current display devices, under strong daylight, the backlight panel will operate at the highest brightness. However, even if the backlight panel can reach a peak brightness of one thousand nits or higher, compared with the ambient light, the brightness of the display is still significantly insufficient, and its users will have difficulty clearly distinguishing the display content of the display. At this time, affected by high temperature and the highest brightness, the service life of the backlight panel will be significantly reduced. Therefore, the existing backlight control circuits are difficult to achieve a balance between high brightness and high life. Summary of the Utility Model

[0006] The purpose of the embodiments of this application is to provide a backlight control circuit for an Android all-in-one machine, aiming to solve the problem that the existing backlight control circuits are difficult to achieve a balance between high brightness and high life.

[0007] The embodiments of this application are implemented as follows. A backlight control circuit for an Android all-in-one machine is provided. The backlight control circuit includes:

[0008] A longitudinal LED backlight unit, a transverse LED backlight unit, a sub-control unit, a DC / DC voltage regulation module, a light intensity sensor, a voltage comparator, a backlight control module, and a controller;

[0009] The longitudinal LED backlight unit is used to provide a longitudinally emitted light source for the LED backlight panel;

[0010] The transverse LED backlight unit is used to provide a transversely emitted light source for the LED backlight panel;

[0011] The light intensity sensor is used to sense the ambient light intensity, obtain a light intensity signal, and output the light intensity signal to the DC / DC voltage regulation module and the voltage comparator;

[0012] The voltage comparator is connected to the input terminal of the light intensity reference voltage, and is used to compare the light intensity signal with the light intensity reference voltage and output a comparison result to the backlight control module;

[0013] The sub-control unit is connected to the DC / DC voltage regulation module, and is used to control the on / off state of the longitudinal LED backlight unit and also used to control the on / off state of the transverse LED backlight unit;

[0014] The DC / DC voltage regulation module is connected to the backlight control module, and is used to perform DC voltage regulation based on the light intensity signal to change the magnitude of the voltage value output to the sub-control unit, thereby controlling the light emission brightness of the longitudinal LED backlight unit and the transverse LED backlight unit;

[0015] The backlight control module is connected to the DC / DC voltage regulation module and is used to output a voltage to it;

[0016] When the voltage value of the light intensity signal is higher than the light intensity reference voltage, the backlight control module controls the sub-control unit to turn off both the longitudinal LED backlight unit and the transverse LED backlight unit simultaneously.

[0017] Preferably, the longitudinal LED backlight unit includes a plurality of longitudinally connected LED units in parallel, and the transverse LED backlight unit includes a plurality of transversely connected LED units in parallel.

[0018] Preferably, the light intensity signal output by the light intensity sensor is a voltage analog signal.

[0019] A control chip is provided in the controller, and a reference voltage output terminal is provided on the control chip, and the reference voltage output terminal is used to output a light intensity reference voltage.

[0020] Preferably, the voltage output by the backlight control module to the DC / DC voltage regulation module is a stable rated DC voltage.

[0021] Preferably, the backlight control module is also connected to the controller inside the display device, and is used to control the on / off states of the longitudinal LED backlight unit and the transverse LED backlight unit based on the control signal output from the controller.

[0022] Preferably, the control signal output by the controller is an analog control quantity.

[0023] The backlight control circuit of an Android all-in-one machine provided by the embodiment of the present application has the following advantages: First, by grouping the light sources in different directions in the display backlight module and using the backlight control module and the sub-control unit to separately control the opening and closing of each backlight emitting unit, it is possible to control the simultaneous opening and closing or separate opening and closing of each backlight unit, avoiding damage to the life of a single backlight unit caused by long-term operation. Second, by obtaining the light intensity of the ambient light and comparing it with the reference voltage, when the light intensity is too strong, the backlight control module directly controls all backlight units to turn off, avoiding emitting light at the highest brightness when it is unable to provide sufficient display brightness, thereby avoiding a rapid reduction in the service life of the backlight unit. Third, using the light intensity sensor of the ambient light to directly control the voltage regulating unit can control the emission brightness of the backlight source based on the ambient light, saving energy and further extending the service life of the light emitting source. Description of the Drawings

[0024] Figure 1 It is a schematic diagram of the circuit module connection of the backlight control circuit of an Android all-in-one machine provided by the embodiment of the present application. Detailed Embodiment

[0025] In order to make the objectives, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0026] Regarding the "coupled" or "connected" used herein, it may refer to two or more elements making direct physical or electrical contact with each other, or making indirect physical or electrical contact with each other, and may also refer to two or more elements operating or acting on each other. The term "circuit" generally refers to an object formed by connecting one or more transistors and / or one or more active and passive elements in a certain manner to process signals.

[0027] However, those skilled in the art should understand that the same element may be referred to by different names. The present application does not use the difference in names as a way to distinguish elements, but uses the difference in the functions of elements as the basis for distinction.

[0028] In addition, the embodiments of the present application cover the features of multiple specific embodiments and the method steps and their sequences for constructing and operating these specific embodiments. However, other specific embodiments can also be used to achieve the same or equivalent functions and step sequences. Unless otherwise defined in this specification, the meanings of the scientific and technical terms used herein are the same as those understood and commonly used by those skilled in the art to which this application belongs. In addition, in the case of not conflicting with the context, the singular nouns used in this specification cover the plural forms of the nouns; and when the plural nouns are used, the singular forms of the nouns are also covered.

[0029] The following describes in detail the specific implementation of the present application in combination with specific embodiments.

[0030] It can be understood that the "horizontal" and "vertical" described in the present application are only used to distinguish two light sources with different light emission directions, and do not represent the actual orientation or spatial position as "horizontal" or "vertical". For example, the light sources in the above two directions can represent two intersecting directions. Preferably, the directions of the two intersecting light sources are perpendicular to each other.

[0031] As Figure 1 shown, it is a schematic diagram of the module connection of a backlight control circuit of an Android all-in-one machine provided by an embodiment of the present application, including:

[0032] The backlight control circuit includes:

[0033] A longitudinal LED backlight unit, a transverse LED backlight unit, a sub-control unit, a DC / DC voltage regulation module, a light intensity sensor, a voltage comparator, a backlight control module, and a controller;

[0034] The longitudinal LED backlight unit is used to provide a longitudinally emitted light source for the LED backlight panel;

[0035] The transverse LED backlight unit is used to provide a transversely emitted light source for the LED backlight panel;

[0036] The light intensity sensor is used to sense the ambient light intensity, obtain a light intensity signal, and output the light intensity signal to the DC / DC voltage regulation module and the voltage comparator;

[0037] The voltage comparator is connected to the input terminal of the light intensity reference voltage, and is used to compare the light intensity signal with the light intensity reference voltage, and output a comparison result to the backlight control module;

[0038] The sub-control unit is connected to the DC / DC voltage regulation module, and is used to control the on / off state of the longitudinal LED backlight unit, and is also used to control the on / off state of the transverse LED backlight unit;

[0039] The DC / DC voltage regulation module is connected to the backlight control module and is used to perform DC voltage regulation based on the light intensity signal to change the magnitude of the voltage value output to the sub-control unit, thereby controlling the light emission brightness of the longitudinal LED backlight unit and the transverse LED backlight unit;

[0040] The backlight control module is connected to the DC / DC voltage regulation module and is used to output a voltage to it;

[0041] When the voltage value of the light intensity signal is higher than the light intensity reference voltage, the backlight control module controls the sub-control unit to turn off both the longitudinal LED backlight unit and the transverse LED backlight unit simultaneously.

[0042] In the embodiment of the present application, the backlight control module can adopt a mainstream backlight control scheme. This module is connected to a voltage comparator and is provided with several input terminals. In this embodiment, the comparison result output by the voltage comparator can be used as a separate input, and the control signal input to the controller as shown in Figure 1 is used as two parallel control inputs to control whether to output a voltage to the DC / DC voltage regulation module and / or control the control signal for turning on or off either the longitudinal LED backlight unit or the transverse LED backlight unit output to the sub-control unit. The comparison result output by the voltage comparator can be a positive voltage, a negative voltage, etc. compared to the reference voltage, which is not limited here.

[0043] Those skilled in the art know that high temperature and constant lighting will both affect the brightness and lifespan of the light-emitting source components. Through the setting of the above modules in the present application, the control of the backlight source has multiple flexible methods, which not only makes the control more flexible, but also reduces energy consumption and is beneficial to extending the service life of the light source. The output voltage of the DC / DC voltage regulation unit can change according to the light intensity signal of the light intensity sensor to save energy and provide an appropriate voltage output.

[0044] The backlight control circuit of an Android all-in-one machine provided by the embodiment of the present application has the following prominent advantages:

[0045] First, by grouping the light sources in different directions in the display backlight module and using the backlight control module and the sub-control unit to separately control the opening and closing of each backlight emitting unit, it is possible to control the simultaneous opening and closing or separate opening and closing of each backlight unit, avoiding damage to the lifespan of a single backlight unit caused by long-term operation.

[0046] Second, by obtaining the light intensity of the ambient light and comparing it with the reference voltage, when the light intensity is too strong, the backlight control module directly controls all backlight units to turn off, avoiding emitting light at the highest brightness when it is impossible to provide sufficient display brightness, thereby avoiding a rapid reduction in the service life of the backlight unit.

[0047] Thirdly, the light intensity sensor that utilizes ambient light directly controls the voltage regulating unit, enabling the control of the luminous brightness of the backlight source based on ambient light, saving energy and further extending the service life of the light-emitting source.

[0048] As a preferred embodiment of the present application, the longitudinal LED backlight unit includes a number of longitudinally-connected LED units in parallel, and the transverse LED backlight unit includes a number of transversely-connected LED units in parallel.

[0049] In the embodiments of the present application, both the transverse and longitudinal display units can be composed of a large number of individual light-emitting elements, such as light-emitting diodes.

[0050] As another preferred embodiment of the present application, the light intensity signal output by the light intensity sensor is a voltage analog signal.

[0051] A control chip is provided in the controller, and a reference voltage output terminal is provided on the control chip for outputting a light intensity reference voltage.

[0052] In the embodiments of the present application, the comparison of the comparator can be made more accurate by obtaining the amplitude change of the voltage signal. The reference voltage can also be directly provided by the voltage output terminal on the control chip to facilitate changing the specific reference voltage according to the actual situation.

[0053] As another preferred embodiment of the present application, the voltage output by the backlight control module to the DC / DC voltage regulating module is a stable rated DC voltage.

[0054] In the embodiments of the present application, only the DC / DC voltage regulating module can be used for voltage regulation, that is, the output terminal of the backlight control module can have only two working modes: outputting a stable voltage and not outputting a voltage.

[0055] As another preferred embodiment of the present application, the backlight control module is also connected to the controller inside the display device, and is used to control the on / off states of the longitudinal LED backlight unit and the transverse LED backlight unit based on the control signal output by the controller.

[0056] In the embodiments of the present application, the DC / DC voltage regulating module can be bypassed based on the control signal in the control chip to directly control the sub-control unit, and then control the on / off states of the longitudinal LED backlight unit and the transverse LED backlight unit, making the user's control and definition of the backlight source more flexible.

[0057] As another preferred embodiment of the present application, the control signal output by the controller is an analog control quantity.

[0058] In the embodiments of the present application, controlling through analog quantity has lower cost and does not require the use of a large number of digital-to-analog converters.

[0059] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A backlight control circuit for an Android all-in-one machine, characterized in that: The backlight source control circuit comprises: Vertical LED backlight unit, horizontal LED backlight unit, sub-control unit, DC / DC voltage regulator module, light intensity sensor, voltage comparator, backlight control module and controller; The longitudinal LED backlight unit is used to provide a longitudinally emitting light source to the LED backlight panel; The horizontal LED backlight unit is used to provide a horizontally emitting light source to the LED backlight panel; The light intensity sensor is used to sense the intensity of ambient light, obtain a light intensity signal, and output the light intensity signal to the DC / DC voltage regulator module and the voltage comparator; The voltage comparator is connected to the input end of the light intensity reference voltage, and is used to compare the light intensity signal with the light intensity reference voltage, and output the comparison result to the backlight control module; The sub-control unit is connected to the DC / DC voltage regulating module and is used to control the on / off status of the longitudinal LED backlight unit and also to control the on / off status of the transverse LED backlight unit; The DC / DC voltage regulating module is connected to the backlight control module and is used to perform DC voltage regulation based on the light intensity signal to change the voltage value output to the sub-control unit, thereby controlling the light brightness of the longitudinal LED backlight unit and the transverse LED backlight unit; The backlight control module is connected to the DC / DC voltage regulator module for outputting voltage thereto; When the voltage value of the light intensity signal is higher than the light intensity reference voltage, the backlight control module controls the sub-control unit to turn off the longitudinal LED backlight unit and the transverse LED backlight unit at the same time.

2. The backlight control circuit of the Android all-in-one machine according to claim 1, characterized in that: The longitudinal LED backlight unit includes a plurality of longitudinal LED units connected in parallel, and the transverse LED backlight unit includes a plurality of transverse LED units connected in parallel.

3. The backlight source control circuit of the Android all-in-one machine according to claim 1, characterized in that: The light intensity signal output by the light intensity sensor is a voltage analog signal. A control chip is arranged in the controller, and a reference voltage output terminal is arranged on the control chip. The reference voltage output terminal is used to output a light intensity reference voltage.

4. The backlight source control circuit of the Android all-in-one machine according to claim 1, characterized in that: The backlight control module outputs a stable rated DC voltage to the DC / DC voltage regulator module.

5. The backlight control circuit of the Android all-in-one machine according to claim 1, characterized in that: The backlight control module is also connected to a controller inside the display device, and is used to control the on / off states of the longitudinal LED backlight unit and the transverse LED backlight unit based on a control signal output from the controller.

6. The backlight source control circuit of the Android all-in-one machine according to claim 5, characterized in that: The control signal output by the controller is an analog control variable.

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