Backlight module of single-layer optimization circuit and brightness compensation method thereof

Abstract

The application discloses a backlight module of single-layer optimized circuit and a brightness compensation method thereof. The design of the brightness compensation is to form the relationship of IV curve 1 by inputting current voltage values of a first light emitter or a third light emitter, and to form the relationship of IV curve 2 by inputting current voltage values of a second light emitter. The LED control IC in the second light emitter has a control module for identifying the IV curve 1 and the IV curve 2, and can correspondingly generate a first Gamma curve and a second Gamma curve. The first Gamma curve controls the output brightness of the first light emitter or the third light emitter, and the second Gamma curve controls the output brightness of the second light emitter. When designing, the IV curve 1 and the IV curve 2 can be adjusted to minimize the characteristic value difference of the two Gamma curves and tend to be the same. The compensation scheme is written into the design scheme of the control IC in the second light emitter, and production and packaging are completed, so that hardware brightness compensation is realized. The application integrates the control IC and the LED lamp bead, and simultaneously realizes the optimization of the circuit structure and the brightness compensation of the backlight module.

Description

Technical Field

[0001] This invention relates to the field of LED display technology, and in particular to a backlight module with a single-layer optimized circuit and its brightness compensation method. Background Technology

[0002] In the backlight market, to achieve high contrast, the original edge-lit backlight module method could not reach the required level. Therefore, direct-lit miniLED backlighting is a technology actively being developed in the industry. This direct-lit method utilizes a matrix arrangement of LED beads. Previously, the number of local dimming zones (local dimming zones) was made more refined. The LED pixel pitch in the local display of Mini LED is also gradually being reduced, shortening the optical distance and reducing the overall thickness to achieve the requirement of thinness. Currently, ordinary LED backlighting with multi-analysis dimming is used as one of the methods to improve TV picture quality. With the advancement of display technology and manufacturing processes, higher precision MiniLEDs are also being applied to TV backlighting. The emergence of MiniLED backlighting has significantly improved the overall effect of TV picture quality. However, due to its fine manufacturing process and its precise light control, when the displayed image is a bright object moving towards the surrounding dark area, a dark shadow phenomenon may appear at the moving edge, thus affecting the quality of the TV picture. To increase the precision of current zone control and achieve accurate control, larger LED modules are generally used. Therefore, the control capacity of the larger panel must also be increased accordingly, which will increase the complexity and load of the circuit system. Using smaller LED beads will be an important trend in Mini LED displays.

[0003] In existing technologies, most display modules bury the wiring connecting the driver chip at the bottom of the substrate, which increases the cost of wiring. Some also use through holes to simplify the wiring, but the processing cost of through holes is high and the number of through holes is large, which affects production efficiency. In addition, the light output brightness of lamp beads containing control chips is lower than that of lamp beads with only LED chips, resulting in poor brightness uniformity of the backlight module as a whole, which affects product quality. Conventional brightness compensation solutions are mostly software program compensation. Summary of the Invention

[0004] To address the aforementioned technical issues, a single-layer optimized circuit backlight module and its brightness compensation method are provided. By integrating control ICs and LED beads on a single-layer board, the number of control ICs used is reduced, the manufacturing process is simplified, production costs are lowered, LED spacing is reduced, product stability and screen uniformity are improved, and hardware compensation is achieved for the backlight module.

[0005] To achieve the above objectives, the present invention discloses a backlight module with a single-layer optimized circuit. The backlight module is composed of several display units arranged in an array. All display units are located on the same side of the substrate. Each display unit contains three sets of light emitters, one of which is an integration of LED and control IC. The display unit is internally connected to the power supply line via wires, and different display units are connected to each other via data input lines. The control IC contains a miniLED control module.

[0006] Furthermore, the display unit is composed of a first light-emitting element, a second light-emitting element, and a third light-emitting element, and the display unit is controlled by a control IC within the second light-emitting element.

[0007] Furthermore, the first light-emitting element is an LED bead without a control IC, the first light-emitting element adopts a PLCC package, and the number of available pins is at least four, and the third light-emitting element has the same structure as the first light-emitting element.

[0008] Furthermore, the second light-emitting element is an LED bead containing a control IC. The second light-emitting element adopts a PLCC package and has at least six available pins.

[0009] Furthermore, the control IC compensates for the brightness differences of its display unit using the IV Gamma curve.

[0010] Furthermore, in the backlight module, the horizontal spacing between every two horizontally arranged display units is the same, and the vertical spacing between every two vertically arranged display units is the same. In the display unit, the vertical spacing between every two adjacent light emitters is the same.

[0011] Furthermore, both the wires and the power cords are made using a sintered copper process.

[0012] Furthermore, the different display units are connected to the second light emitter via data input lines embedded in the substrate, or via ohmic resistors.

[0013] A brightness compensation method for a backlight module with a single-layer optimized circuit is disclosed. The method establishes an IV curve (IV1) based on the input current and voltage values ​​of a first or third light-emitting element, and an IV curve (IV2) based on the input current and voltage values ​​of a second light-emitting element. The LED control IC within the second light-emitting element has a control module that identifies IV curves 1 and 2, and can generate a first Gamma curve and a second Gamma curve accordingly. The first Gamma curve controls the output brightness of the first or third light-emitting element, while the second Gamma curve controls the output brightness of the second light-emitting element. During design, IV curves 1 and 2 can be adjusted to minimize the difference in characteristic values ​​between the two Gamma curves and bring them closer to the same value. This compensation scheme is incorporated into the design of the control IC within the second light-emitting element, and production and packaging are completed to achieve hardware brightness compensation.

[0014] Furthermore, the compensation scheme can be written into the target by replacing the control IC with a miniLED control module, and software brightness compensation can be achieved by using PWM to control the control IC in the second light-emitting body.

[0015] Compared with the prior art, the beneficial effects of this invention are as follows: This invention discloses a backlight module with a single-layer optimized circuit and its brightness compensation method. The control circuit and LED chip are packaged together, which can reduce circuit complexity and complete the circuit design using a single-sided circuit board; a single control chip can control multiple LED beads, reducing the number of control ICs and lowering the cost of the backlight module; the control chip and LED chip are packaged together, reducing the area occupied by the control IC on the circuit and significantly reducing the LED spacing; the uniformity of the LED brightness can be significantly improved through hardware compensation of the control IC. Attached Figure Description

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0017] Figure 1 This is a 3-channel LED circuit according to Embodiment 1 of the present invention.

[0018] Figure 2 This is a 6-channel LED circuit according to Embodiment 2 of the present invention.

[0019] Figure 3 This is a schematic diagram of the display module structure of the present invention.

[0020] Figure 4 This is a Gamma curve diagram of the present invention.

[0021] Figure 5 This is a flowchart of the hardware compensation method of the present invention.

[0022] Figure 6 This is a flowchart of the software compensation method of the present invention.

[0023] In the diagram: 1 is the display unit; 2 is the first light-emitting element; 3 is the second light-emitting element; 4 is the third light-emitting element; 5 is the substrate;

[0024] GND is the ground line; Vdd is the power line; DATA is the data input line. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0026] like Figure 1 and Figure 3 As shown in Embodiment 1 of the present invention, a backlight module with a single-layer optimized circuit, taking a 3-channel LED circuit as an example, the backlight module is composed of several display units 1 arranged in an array. The display units 1 are all located on the same side of the substrate 5. Each display unit 1 contains three sets of light emitters, one of which is an integration of LED and control IC. The display unit 1 is connected to the power supply line through wires, and different display units 1 are connected to each other through data input lines. The control IC is equipped with a miniLED control module. By integrating the control IC and LED chip into one unit, the LED spacing is reduced, the circuit complexity is simplified, and regional control of the backlight module is realized.

[0027] The display unit 1 consists of a first light-emitting element 2, a second light-emitting element 3, and a third light-emitting element 4. The display unit 1 is controlled by a control IC within the second light-emitting element 3. By controlling three groups of LED beads simultaneously with one set of control ICs, the amount of IC chips used is reduced, thus reducing production costs.

[0028] The first light-emitting element 2 is an LED bead without a control IC. The first light-emitting element 2 adopts a PLCC package and has at least four available pins. The third light-emitting element has the same structure as the first light-emitting element. The PLCC package further reduces the module size.

[0029] The second light-emitting element 3 is an LED bead containing a control IC. The second light-emitting element 3 adopts a PLCC package and has at least six available pins. The PLCC package further reduces the module size.

[0030] In the backlight module, the horizontal spacing between any two horizontally arranged display units 1 is the same, and the vertical spacing between any two vertically arranged display units 1 is the same. In the display unit 1, the vertical spacing between any two adjacent light emitters is the same. The uniform arrangement of the display units can improve the uniformity of the backlight module image and improve product quality.

[0031] Both the wires and power lines are made using a sintered copper process. Sintered copper circuitry not only reduces circuit impedance but also improves the brightness of the LED chips and enhances the heat dissipation performance of the substrate.

[0032] Different display units 1 are connected to the second light emitter 3 through data input lines embedded in the substrate 5, or by bridging through ohmic resistors, thereby reducing wiring distance and optimizing the circuit.

[0033] A brightness compensation method for a backlight module with a single-layer optimized circuit, such as... Figure 4 and Figure 5 As shown, the brightness compensation design uses the input current and voltage values ​​of the first or third light-emitting element to form IV curve 1, and the input current and voltage values ​​of the second light-emitting element to form IV curve 2. The LED control IC in the second light-emitting element has a control module that identifies IV curve 1 and IV curve 2, and can generate a first Gamma curve and a second Gamma curve accordingly. The first Gamma curve controls the output brightness of the first or third light-emitting element, and the second Gamma curve controls the output brightness of the second light-emitting element. During the design, IV curve 1 and IV curve 2 can be appropriately adjusted to minimize the difference in characteristic values ​​between the two Gamma curves and make them approach the same. This compensation scheme is written into the design scheme of the control IC in the second light-emitting element and production and packaging are completed to realize hardware brightness compensation, optimize the circuit structure and improve the uniformity of the screen.

[0034] like Figure 2 As shown, in a second embodiment of the present invention, a 6-channel LED circuit is provided. Based on the first embodiment, the control IC additionally controls three groups of LEDs, and six groups of light emitters are controlled by one control IC. The control IC is integrated with one of the light emitters, which reduces the number of control ICs used in a single backlight module, controls production costs, simplifies circuit design, realizes a one-to-many control method, reduces LED spacing, and improves the backlight module display.

[0035] In the third embodiment of the present invention, another single-layer optimized circuit backlight module and its brightness compensation method are described. The compensation scheme can be written to the target by replacing the control IC with a miniLED control module, and the control IC in the second light-emitting body is controlled by PWM to realize software brightness compensation. Compared with the hardware compensation adjustment method, it is more flexible and can be used as a backup scheme when the hardware compensation fails.

[0036] The working principle of this invention: The backlight module is composed of an array of several display units 1, which are connected to each other via data input lines. The second light-emitting element 3 in the display unit 1 is an integrated structure of IC and LED. The control IC is connected via the data input lines and controls the LEDs. All light-emitting elements use 2835 LED chips without PLCC packaging. The second light-emitting element 3 has at least six usable pins, two of which are connected to the first and third light-emitting elements respectively, the other two are connected to other display units 1 via data input lines, and the remaining two are connected to the power line and ground line. Because the second light-emitting element 3 is an integrated structure of control IC and LED chip, the brightness of the second light-emitting element 3 is reduced by 10% compared to other light-emitting elements, affecting the picture quality. Uniformity is achieved by considering the relationship between the input current and voltage values ​​of the first light-emitting element 2 or the third light-emitting element 4 forming IV curve 1, and the relationship between the input current and voltage values ​​of the second light-emitting element 3 forming IV curve 2. The LED control IC inside the second light-emitting element 3 has a control module that identifies IV curve 1 and IV curve 2, and can generate a first Gamma curve and a second Gamma curve accordingly. The first Gamma curve controls the output brightness of the first light-emitting element 2 or the third light-emitting element 4, and the second Gamma curve controls the output brightness of the second light-emitting element. By appropriately adjusting IV curve 1 and IV curve 2, the difference in characteristic values ​​of the two Gamma curves is minimized and brought closer to the same. This compensation scheme is written into the design scheme of the control IC inside the second light-emitting element 3 and production and packaging are completed to realize hardware brightness compensation.

[0037] Several points need to be clarified: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly, and can refer to mechanical or electrical connections, or internal connections between two components, or direct connections. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships, and the relative positional relationships may change when the absolute position of the described objects changes. Second, in this document, relational terms such as "first" and "second" are only used to distinguish one entity from another entity, and do not necessarily require or imply any such actual relationship or order between these entities.

[0038] The examples above are merely illustrative of the present invention and do not constitute a limitation on the scope of protection of the present invention. Any designs that are the same as or similar to the present invention are within the scope of protection of the present invention.

Claims

1. A backlight module with a single-layer optimized circuit, characterized in that: The backlight module is composed of several display units (1) arranged in an array. The display units (1) are all located on the same side of the substrate (5). Each display unit (1) contains at least three sets of light emitters, one of which is an integration of LED and control IC. The display unit (1) is connected to the power supply line through wires. Different display units (1) are connected to each other through data input lines. The control IC is equipped with a miniLED control module. The display unit (1) is composed of a first light emitter (2), a second light emitter (3) and a third light emitter (4). The display unit (1) is controlled by the control IC in the second light emitter (3). The first light emitter (2) is an LED without a control IC. The first light emitter (2) adopts a PLCC package and has at least two available pins. The third light emitter (4) has the same structure as the first light emitter (2).

2. A backlight module with a single-layer optimized circuit according to claim 1, characterized in that: The second light-emitting element (3) is an LED bead containing a control IC. The second light-emitting element (3) adopts a PLCC package and has at least six available pins.

3. A backlight module with a single-layer optimized circuit according to claim 1, characterized in that: In the backlight module, the horizontal spacing between every two horizontally arranged display units (1) is the same, and the vertical spacing between every two vertically arranged display units (1) is the same. In the display unit (1), the vertical spacing between every two adjacent light emitters is the same.

4. A backlight module with a single-layer optimized circuit according to claim 1, characterized in that: Both the conductors and the power cord are made using a sintered copper process.

5. A backlight module with a single-layer optimized circuit according to claim 1, characterized in that: The different display units (1) are connected to the second light emitter (3) through data input lines embedded in the substrate (5), or are bridged by ohmic resistors.

6. A brightness compensation method for a backlight module of a single-layer optimized circuit according to any one of claims 1-5, characterized in that: Includes the following steps S1: The relationship between the input current and voltage values ​​of the first light-emitting body (2) or the third light-emitting body (4) to form IV curve 1; S2: The relationship between the input current and voltage values ​​of the second light-emitting body (3) forming the IV curve 2; S3: The LED control IC in the second light-emitting body has a control module that identifies IV curve 1 and IV curve 2, and can generate the first Gamma curve and the second Gamma curve accordingly. The first Gamma curve controls the output brightness of the first light-emitting body (2) or the third light-emitting body (4), and the second Gamma curve controls the output brightness of the second light-emitting body (3). S4: During the design, IV curve 1 and IV curve 2 can be adjusted to minimize the difference in the characteristic values ​​of the two Gamma curves and bring them closer to the same value. S5: Write this compensation scheme into the design scheme of the control IC inside the second light source (3) and complete the production and packaging to realize hardware brightness compensation.

7. A brightness compensation method for a backlight module of a single-layer optimized circuit according to claim 6, characterized in that: In step S5, the compensation scheme can be written to the target by replacing the control IC with a miniLED control module, and the software brightness compensation can be achieved by using PWM to control the control IC in the second light-emitting body (3).

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