CN113934054B

CN113934054B - Display with regional dimming function, dimming method and backlight module

Info

Publication number: CN113934054B
Application number: CN202111247349.1A
Authority: CN
Inventors: 郭辉
Original assignee: Jiashi Shandong Electronic Technology Co ltd
Current assignee: Jiashi Shandong Electronic Technology Co ltd
Priority date: 2021-10-26
Filing date: 2021-10-26
Publication date: 2022-05-17
Anticipated expiration: 2041-10-26
Also published as: CN113934054A; CN114758628B; CN114758628A

Abstract

The invention relates to the field of displays, in particular to a display for regional dimming, a dimming method and a backlight module.A composite light source arranged in a matrix manner is arranged on a PCB (printed Circuit Board), and the composite light source comprises a basic lamp bead and at least one dimming lamp bead; the power interfaces of all the basic lamp beads are connected with a first dimming power supply, the dimming lamp beads are electrically connected with a local dimming module, and the power interfaces of the local dimming module are connected with a second dimming power supply; the local dimming module is provided with a local dimming controller, an initial light power module, a local dimming power module and a selector switch which corresponds to the dimming lamp beads one by one, and two inputs of the selector switch are respectively electrically connected with the initial light power module and the local dimming power module; the output end of the change-over switch is electrically connected with the dimming lamp bead, and the change-over switch is electrically connected with the local dimming controller. The invention can perform local dimming on the liquid crystal display and simultaneously achieve the beneficial effect of reducing power consumption.

Description

Display with regional dimming function, dimming method and backlight module

Technical Field

The invention relates to the field of displays, in particular to a display with regional dimming, a dimming method and a backlight module.

Background

Currently, for the lcd, in a special application, a specific area on the screen of the lcd needs to be highlighted or darkened, or a highlight band is formed to move from left to right or from top to bottom on the screen. The existing display can only adjust the brightness of the screen of the whole display. Therefore, it is an urgent requirement to design a liquid crystal display capable of local dimming.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: a display with local dimming, a dimming method and a backlight module are provided.

The utility model provides a regional dimming backlight module for LCD, includes the PCB board, its characterized in that: the PCB is provided with composite light sources arranged in a matrix manner, the upper part of the PCB is provided with a light guide partition, the light guide partition is in a honeycomb shape, and each groove of the light guide partition surrounds one composite light source; the side wall of the light guide partition is coated with a diffuse reflection coating; the composite light source comprises a basic lamp bead and at least one dimming lamp bead; the power interfaces of all the basic lamp beads are connected with a first dimming power supply, the dimming lamp beads are electrically connected with a local dimming module, and the power interfaces of the local dimming module are connected with a second dimming power supply; the local dimming module is provided with a local dimming controller, an initial light power module, a local dimming power module and a selector switch which corresponds to the dimming lamp beads one by one, and two inputs of the selector switch are respectively electrically connected with the initial light power module and the local dimming power module; the output end of the change-over switch is electrically connected with the dimming lamp bead, and the change-over switch is electrically connected with the local dimming controller.

Preferably, the PCB board is provided with an initial light bus and a regional dimming bus which are arranged in a row.

Preferably, the change-over switch is a relay provided with a normally open normally closed contact; a normally open contact of the relay is connected between the initial light bus and the dimming lamp bead; the normally closed contact of the relay is connected between the regional dimming bus and the dimming lamp bead;

or the like, or, alternatively,

the change-over switch comprises a first switch tube and a second switch tube; the first switch tube is connected between the initial light bus and the dimming lamp bead; the second switch tube is connected between the regional dimming bus and the dimming lamp bead.

A local dimming display comprises a power module, a driving module, a liquid crystal display panel and a frame thereof, and is applied to a local dimming backlight module for the liquid crystal display.

Preferably, when dimming of the area is required:

reducing the voltage of the first dimming power supply to reduce the brightness of all basic lamp beads;

switching a power supply of the dimming lamp bead outside the defined area to a regional dimming bus; the local dimming controller controls the power supply of the local dimming power supply module to boost the voltage, so that dimming lamp beads outside the defined area become bright;

and keeping the power supply of the dimming lamp bead in the enclosed area connected with the initial light bus, and keeping the voltage of the initial light power supply module unchanged.

Preferably, when the area needs to be brightened:

switching a power supply of dimming lamp beads in the enclosed area to a local dimming bus;

the local dimming controller controls the power supply of the local dimming power supply module to boost voltage, so that dimming lamp beads in the delineating region become bright.

Preferably, an external control instruction is received to set a brightness adjusting area and a dimming area;

switching a power supply of the dimming lamp beads in the dimming area to a local dimming bus;

switching a power supply of the dimming lamp beads in the dimming area to an initial light bus;

the local dimming controller controls the power supply of the local dimming power supply module to boost the voltage, so that dimming lamp beads in the dimming area become bright;

the regional dimming controller controls the power supply of the initial light power supply module to reduce the voltage, so that dimming lamp beads in a dimming region become dark.

Preferably, an external control instruction is received to set a first brightness area, a second brightness area and a third brightness area … … tail brightness area;

determining the number of high-brightness composite light sources and the number of dark composite light sources in the brightness area according to the brightness of the brightness area; the dimming lamp beads in the high-brightness composite light source are independently connected with the regional dimming power supply module; the dimming lamp bead of the dark composite light source is independently connected with the initial light power module; the high-brightness composite light source and the dark composite light source are uniformly distributed at intervals;

determining the voltage of the local dimming power supply module according to the brightest brightness region; and determining the voltage of the initial light power supply module according to the darkest brightness area.

Preferably, a second liquid crystal dimming layer is arranged on the upper part of the light guide partition, and the second liquid crystal dimming layer is overlapped with the original liquid crystal layer of the display;

the second liquid crystal dimming layer is provided with three dimming liquid crystals corresponding to each pixel, and the arrangement direction of the three dimming liquid crystals is vertical to the liquid crystal arrangement direction of each pixel of the original liquid crystal layer.

Preferably, when dimming is required:

acquiring a region defined by an operator on a screen through a touch module;

and adjusting the voltage at two ends of the liquid crystal in the corresponding circle area in the second liquid crystal dimming layer to change the brightness of the light passing through the second liquid crystal dimming layer.

The invention has the beneficial effects that:

local dimming of the liquid crystal display can be performed.

The effect of reducing power consumption can be achieved by performing local dimming.

Drawings

Fig. 1 is a schematic diagram of a distribution of leds according to an embodiment of the present invention.

FIG. 2 is a schematic circuit diagram of an embodiment of the present invention.

FIG. 3 is a schematic circuit diagram of an embodiment of the present invention.

Fig. 4 is a schematic diagram of an embodiment of liquid crystal control dimming according to the present invention.

FIG. 5 is a schematic diagram of the liquid crystal distribution of an embodiment of the liquid crystal control dimming of the present invention.

FIG. 6 is a schematic diagram of a composite light source distribution according to an embodiment of the present invention.

In the figure: 410. dimming the liquid crystal; 820. a second dimming power supply; 810. a first dimming power supply; 400. a second liquid crystal dimming layer; 120. a local dimming bus; 110. an initial optical bus; 233. a local dimming controller; 232. a local dimming power supply module; 231. an initial light power module; 240. a switch; 230. a local dimming module; 220. a dimming lamp bead; 210. a base bead; 300. light guide partition; 200. a composite light source; 200a, a high-brightness composite light source; 200b, a dark composite light source; 100. a PCB board;

Detailed Description

In order to make the technical solution and the advantages of the present invention clearer, the following explains embodiments of the present invention in further detail.

Example one

A local dimming backlight module for a liquid crystal display comprises a PCB (printed Circuit Board) 100, wherein composite light sources 200 arranged in a matrix manner are arranged on the PCB 100. The upper part of the PCB 100 is provided with a light guide partition 300. The light guide partition 300 has a plate shape with a certain thickness, and is provided with a honeycomb-shaped through hole at an upper portion thereof, wherein the cross-sectional shape of the through hole may be a regular hexagon. Each groove of the light guide partition 300 surrounds one composite light source 200, each through hole serves as a container for containing the composite light source 200, and light of the composite light source irradiates the liquid crystal layer through the through hole. In order to make the light have better diffusion effect, the sidewall of the light guide partition 300 is coated with a diffuse reflection coating.

In order to realize dimming and ensure the brightness balance of the light source, the composite light source 200 includes a base light bead 210 and at least one dimming light bead 220. Basic lamp pearl 210 is supplied power by same power, all in this embodiment the power interface of basic lamp pearl 210 connects first power 810 of adjusting luminance. The first dimming power supply 810 can adjust the brightness of the base lamp beads 210, and all the base lamp beads 210 are synchronously adjusted. The brightness of the whole liquid crystal display screen can be ensured to be balanced.

Taking an example of setting one dimming lamp bead 220, the dimming lamp bead 220 is electrically connected to the local dimming module 230, and a power interface of the local dimming module 230 is connected to the second dimming power 820. The local dimming module 230 is provided with a local dimming controller 233, an initial light power module 231, a local dimming power module 232, and a switch 240 corresponding to the dimming lamp beads 220 one to one.

The function of the change-over switch 240 is to realize the switching of two input power supplies, two inputs of the change-over switch 240 are respectively electrically connected with the initial light power supply module 231 and the regional dimming power supply module 232, and the output end of the change-over switch 240 is electrically connected with the dimming lamp bead 220. Through the control of controller, the power supply of adjusting luminance lamp pearl 220 can switch to initial light power module 231 or regional power module 232 of adjusting luminance, and then controls through different powers, realizes regional regulation of adjusting luminance. The switch 240 is electrically connected to the local dimming controller 233. The local dimming controller 233 is a processor or a dimming module program integrated in an internal controller of the liquid crystal display, and the processor or the dimming module program implements local dimming according to the dimming method disclosed in the present invention.

Wherein the switch 240 is a relay provided with a normally open and normally closed contact; the normally open contact of the relay is connected between the initial light bus 110 and the dimming lamp bead 220; and the normally closed contact of the relay is connected between the regional dimming bus bar 120 and the dimming lamp bead 220.

Alternatively, the switch 240 includes a first switch tube and a second switch tube; the first switch tube is connected between the initial light bus 110 and the dimming lamp bead 220; the second switch tube is connected between the regional dimming bus bar 120 and the dimming lamp bead 220.

In practical application, to adjust luminance lamp pearl 220 and be connected with the power alone, when carrying out independent control, because the influence of circuit length change, the power of adjusting luminance lamp pearl can't guarantee the equilibrium, and then the difference of luminance can appear, in order to avoid above-mentioned problem, set up the power bus on PCB board 100 and supply power for adjusting luminance lamp pearl 220. Wherein the power bus bars are arranged in a row on the PCB board 100 and include an initial light bus bar 110 and a local dimming bus bar 120. In order to reduce the cross-over, an anode bus and a cathode bus can be respectively laid on the upper surface layer and the lower surface layer of the PCB board 100, and the initial light bus 110 and the local dimming bus 120 are laid on two sides of the dimming lamp bead 220. Meanwhile, the switch 240 and the dimming lamp bead 220 are arranged at intervals, and one switch 240 controls one dimming lamp bead 220.

When the regional dimming is carried out again, the regional brightness of one part of the screen is unchanged, and the scheduling of the rest part of the screen can be adjusted. And the dimming lamp beads 220 of the region needing to be adjusted are uniformly connected with the regional dimming power supply module 232 through the regional dimming bus bar 120. The other part is connected to the original light bus bar 110 and is uniformly connected to the original light power module 231. The local dimming power module 232 and the initial light power module 231 are connected to the external second dimming power 820, and they are power sources that can be controlled independently, so that the brightness variation difference of the areas that do not need to be adjusted is small, and the areas that need to be adjusted can be adjusted in brightness.

When setting up a plurality of lamp pearls of adjusting luminance, including the first lamp pearl of adjusting luminance, the second lamp pearl of adjusting luminance, the third lamp pearl of adjusting luminance etc. this moment. All first lamp pearls of adjusting luminance pass through the generating line and are connected with power one, and all second lamp pearls of adjusting luminance pass through the generating line and are connected with power two, and all third lamp pearls of adjusting luminance pass through the generating line and are connected with power three to analogize. Simultaneously, each dimming lamp bead is provided with a control switch, and at the moment, the brightness is adjusted by controlling the lighting quantity of the dimming lamp beads. The power supply of one group of dimming lamp beads 220 can be set to be an adjustable power supply, and then the fine tuning function can be achieved.

The local dimming power module 232 is an adjustable power module, and can adjust the voltage by connecting and disconnecting resistors in series and parallel and removing the connecting and disconnecting resistors in series and parallel. Similarly, the local dimming power module 232 may also be a voltage regulator of a thyristor, and the voltage may be adjusted by adjusting a duty ratio. Similarly, the initial light power module 231 is configured as the same adjustable power module.

Example two

A local dimming display comprises a power module, a driving module, a liquid crystal display panel and a frame thereof, and a local dimming backlight module for the liquid crystal display according to an application embodiment.

In order to perform local dimming, it is necessary to acquire a region for performing local dimming, and therefore, the display in this embodiment is further provided with a region setting module. The area setting module comprises an area adjusting button arranged on the frame and a touch module integrated on the screen. The touch module adopts a capacitive touch screen or a surface acoustic wave touch screen. The technology of touch screens is now well established, and the position on the screen can be acquired by applying the technology of touch screens. Both capacitive touch screens and surface acoustic wave touch screens can be multi-sampled. In this embodiment, through artificial sliding, when drawing a closed region that needs to adjust luminance, the touch screen can detect the position that the staff slided, then calculates the region that corresponds on the backlight unit to select the lamp pearl 220 of adjusting luminance that corresponds regional inside, will adjust luminance the lamp pearl and switch to on initial light generating line 110 or regional light generating line 120 of adjusting luminance. When dimming, the dimming lamp beads needing to be controlled are obtained through the mode, then the brightness is adjusted through the area adjusting buttons, the brightness can be improved through the increment buttons, or the brightness is reduced through the decrement buttons. In the process of realizing brightness adjustment, the following specific implementation methods are included:

a

A method for carrying out regional highlight adjustment on a regional dimming display comprises the following steps that when a region needs to be brightened:

and acquiring a region defined by an operator on a screen through the touch module. For example, when a part of the display displays a picture, the picture needs to be highlighted, and then an area can be drawn along the edge of the picture. Especially, in large-size display screens and large-size advertisement display screens, the display is required to be partitioned and disconnected for displaying with different brightness, and the characteristic of energy consumption saving embodied by the invention can be displayed at the moment.

The power supply of the dimming lamp bead 220 in the enclosed area is switched to the local dimming bus 120. Because the local dimming bus 120 is connected with the output end of the local dimming power module 232, the dimming lamp beads 220 in the defined area are all powered by the local dimming power module 232. The local dimming controller 233 is electrically connected to the local dimming power module 232, and after the local dimming controller 233 receives the adjustment signal, the local dimming power module 232 is controlled to adjust the output voltage thereof, that is, the local dimming controller 233 controls the power of the local dimming power module 232 to boost the voltage, so that the dimming lamp beads 220 in the defined region become bright. In an initial state, or in a default state, the dimming lamp beads 220 are connected to the initial light bus 110, at this time, the dimming lamp beads 220 of other undefined regions are kept connected to the initial light bus 110, the power module of the initial light power module 231 connected to the initial light bus 110 is not adjusted, meanwhile, the power supply of the basic lamp beads 210 is not adjusted, and further, the brightness of the undefined regions is kept unchanged.

A method for dimming a local area of a local dimming display, when dimming the local area, comprises the following steps:

and acquiring a region defined by an operator on a screen through the touch module. Because basic lamp pearl 210 has the function of adjusting luminance, in order to guarantee the original function of adjusting luminance of LCD, adjust luminance lamp pearl 220 initial state under with initial light bus 110 be connected, and in order not to influence luminance, the mains voltage on initial light bus 110 keeps in the low-voltage state, and then can guarantee original dimming range. When the brightness needs to be reduced, the voltage reduction force of the initial light bus 110 is limited, so that the voltage of the first dimming power supply needs to be reduced, and the brightness of all the basic lamp beads 210 is reduced. Meanwhile, the power supply of the dimming lamp bead 220 outside the delineating region is switched to the regional dimming bus 120; the local dimming controller 233 controls the power supply of the local dimming power supply module 232 to boost the voltage, so that the dimming lamp beads 220 outside the defined region become bright; the brightness in the undefined area is ensured to be unchanged through the adjustment of the two. The dimming lamp beads in the delineating region are always connected with the initial light bus 110, and the voltage of the initial light power module 231 is kept unchanged. At initial light bus 110 voltage unchangeable, the lamp pearl luminance of adjusting luminance of the inside of delineating the region is unchangeable, and the luminance of basic lamp pearl 210 reduces, and then has realized the adjustment of luminance reduction.

Based on the above two embodiments, the adjustment of the regional brightness can also be realized by providing the second liquid crystal dimming layer 400. At this time, a second liquid crystal light modulation layer 400 is disposed on the upper portion of the light guide partition 300, and the second liquid crystal light modulation layer 400 is disposed to overlap the original liquid crystal layer of the display. The second liquid crystal light modulation layer 400 controls the degree of light transmission of the light guide partition 300 to the original liquid crystal layer. By controlling the voltage across the liquid crystal of the second liquid crystal dimming layer 400, the amount of light transmitted can be controlled, and the brightness can be changed.

Besides manual adjustment, different brightness of different areas can be set according to external controls such as image processing software and image display software, so that a more optimized and clear image display effect is achieved. In order to better display a picture, the brightness of a specific area in the picture needs to be adjusted, and the optimal brightness of each area can be calculated through software and an algorithm.

When the region needs to be dimmed, the voltage of the first dimming power supply is firstly reduced, so that the brightness of all the basic lamp beads 210 is reduced. Then, the power supply of the dimming lamp bead 220 outside the defined region is switched to the regional dimming bus 120; the local dimming controller 233 controls the power supply of the local dimming power module 232 to boost the voltage, so that the dimming lamp beads 220 outside the defined region become bright.

At this time, the power supply of the dimming lamp bead 220 in the enclosed area is kept connected to the initial light bus bar 110, and the voltage of the initial light power module 231 is kept unchanged.

When the area needs to be lightened, the power supply of the dimming lamp bead 220 in the enclosed area is switched to the local dimming bus 120. Then, the local dimming controller 233 controls the power supply of the local dimming power module 232 to boost the power supply, so that the dimming lamp beads 220 in the delineated region become bright.

In some complicated image display processes, brightness adjustment is required to be performed on a plurality of areas in order to achieve a better display effect. The invention also discloses a method for adjusting the brightness of the two areas, which comprises the following steps:

firstly, an external control instruction is received to set a dimming area and a dimming area. When the image processing and displaying module receives an image, in order to achieve a better display effect, the image processing and displaying module calculates the image to obtain an area needing to increase the brightness and reduce the brightness. After the area is obtained, the division information of the area is sent to the display, and the controller of the display controls according to the area information.

Then, the local dimming controller 233 switches the power supply of the dimming lamp bead 220 in the dimming area to the local dimming bus 120; the power supply of the dimming lamp bead 220 in the dimming dark area is switched to the initial light bus 110. Meanwhile, the local dimming controller 233 controls the power supply of the local dimming power module 232 to be boosted, so that the dimming lamp beads 220 in the dimming area become bright, and the local dimming controller 233 controls the power supply of the initial light power module 231 to be reduced in voltage, so that the dimming lamp beads 220 in the dimming area become dark. At this time, the brightness of the area that needs to be brightened is increased, and the brightness of the dimmed area is decreased.

Besides the above processing modes, the device responsible for image processing can also set a plurality of areas with different brightness to achieve an optimized display effect. At this time, the process of the present invention,

first, an external control command is received to set a first brightness region, a second brightness region, and an end brightness region … … of the third brightness region.

Then, determining the number of the high-brightness composite light sources 200a and the number of the dark composite light sources 200b in the brightness area according to the brightness of the brightness area; the dimming lamp bead 220 inside the high-brightness composite light source 200a is independently connected with the regional dimming power module 232; the dimming lamp bead 220 of the dark composite light source 200b is separately connected with the initial light power module 231; the high-brightness composite light source 200a and the dark composite light source 200b are uniformly distributed at intervals. If there are half of high light composite light source 200a and half of dark composite light source 200b, high light composite light source 200a and dark composite light source 200b are arranged at intervals. The light sources in other proportions are uniformly arranged at the same proportion interval, as shown in fig. 6, which is a schematic diagram of the distribution of a composite light source with one-third high brightness and two-thirds dark.

Finally, the voltage of the local dimming power module 232 is determined according to the brightest brightness region; the voltage level of the initial light power module 231 is determined according to the darkest luminance region.

After the above configuration is set, the initial light power module 231, the local dimming power module 232, and the switch 240 are controlled to control the brightness.

Preferably, in order to simplify the control, the second liquid crystal light modulation layer 400 is provided with three light modulation liquid crystals corresponding to each pixel, and the arrangement direction of the three light modulation liquid crystals 410 is perpendicular to the liquid crystal arrangement direction of each pixel of the original liquid crystal layer. The adjustment of the light transmittance is realized by notifying the number of the three dimming liquid crystals.

In this case, when the luminance of light needs to be adjusted:

firstly, a region needing dimming on a display is obtained through a touch module or receiving an external control instruction.

Then, the voltage across the liquid crystal in the corresponding area of the second liquid crystal dimming layer is adjusted, so that the light passing through the second liquid crystal dimming layer 400 changes in brightness.

Alternatively, changing the number of on three dimming liquid crystals corresponding to a single pixel inside the defined area in the second liquid crystal dimming layer 400 changes the brightness of the liquid crystal display.

When a pair of dimming lamp beads is set, each dimming lamp bead 220 configures the corresponding initial light bus 110 and local dimming bus 120, and the corresponding initial light bus 110 and local dimming bus 120 are connected to the independent initial light power module 231 and local dimming power module 232. And utilize above-mentioned mode to control luminance, under the condition that adjust luminance lamp pearl 220 is many, can reach better regional dimming effect.

In summary, the present invention is only a preferred embodiment, and is not intended to limit the scope of the present invention, and various changes and modifications can be made by workers in the light of the above description without departing from the technical spirit of the present invention. The technical scope of the present invention is not limited to the content of the specification, and all equivalent changes and modifications in the shape, structure, characteristics and spirit described in the scope of the claims of the present invention are included in the scope of the claims of the present invention.

Claims

1. The utility model provides a regional dimming backlight module for LCD, includes PCB board (100), its characterized in that:

the LED light source module is characterized in that composite light sources (200) are arranged in a matrix mode on the PCB (100), a light guide partition (300) is arranged on the upper portion of the PCB (100), the light guide partition (300) is in a honeycomb shape, and each groove of the light guide partition (300) surrounds one composite light source (200); the side wall of the light guide partition (300) is coated with a diffuse reflection coating;

the composite light source (200) comprises a basic light bead (210) and at least one dimming light bead (220); the power interfaces of all the basic lamp beads (210) are connected with a first dimming power supply (810), the dimming lamp beads (220) are electrically connected with a local dimming module (230), and the power interfaces of the local dimming module (230) are connected with a second dimming power supply (820);

the regional dimming module (230) is provided with a regional dimming controller (233), an initial light power module (231), a regional dimming power module (232) and a change-over switch (240) which corresponds to the dimming lamp beads (220) one by one, and two inputs of the change-over switch (240) are respectively and electrically connected with the initial light power module (231) and the regional dimming power module (232); the output end of the change-over switch (240) is electrically connected with the dimming lamp bead (220), and the change-over switch (240) is electrically connected with the regional dimming controller (233).

2. The local dimming backlight module for liquid crystal display according to claim 1, wherein:

the PCB (100) is provided with an initial light bus (110) and a regional dimming bus (120) which are arranged in a row.

3. The local dimming backlight module for liquid crystal display according to claim 2, wherein:

the change-over switch (240) is a relay provided with a normally open normally closed contact; a normally open contact of the relay is connected between the initial light bus (110) and the dimming lamp bead (220); a normally closed contact of the relay is connected between the regional dimming bus (120) and the dimming lamp bead (220);

or the like, or, alternatively,

the change-over switch (240) comprises a first switch tube and a second switch tube; the first switch tube is connected between the initial light bus (110) and the dimming lamp bead (220); the second switch tube is connected between the regional dimming bus (120) and the dimming lamp bead (220).

4. A local dimming display comprises a power module, a driving module, a liquid crystal display panel and a frame thereof, and is characterized in that:

an LCD local dimming backlight module as claimed in any one of claims 1 to 3.

5. The method of claim 4, wherein the method comprises:

when the area needs to be dimmed:

reducing the voltage of the first dimming power supply to reduce the brightness of all the basic lamp beads (210);

switching a power supply of the dimming lamp bead (220) outside the defined region to a regional dimming bus (120); the local dimming controller (233) controls the power supply of the local dimming power supply module (232) to boost the voltage, so that dimming lamp beads (220) outside the defined region become bright;

and keeping the power supply of the dimming lamp beads (220) in the enclosed area connected with the initial light bus (110), and keeping the voltage of the initial light power supply module (231) unchanged.

6. The method of claim 4, wherein the area brightness adjustment is performed by a local dimming display, and the method further comprises:

when the area needs to be lightened:

switching a power supply of dimming lamp beads (220) in the enclosed area to a regional dimming bus (120);

the local dimming controller (233) controls the power supply of the local dimming power supply module (232) to boost voltage, so that dimming lamp beads (220) in the defined area become bright.

7. The method of claim 4, wherein the method further comprises:

receiving an external control instruction to set a brightness adjusting area and a dimming area;

switching a power supply of a dimming lamp bead (220) in a dimming area to a local dimming bus (120);

switching a power supply of a dimming lamp bead (220) in a dimming area to an initial light bus (110);

the local dimming controller (233) controls the power supply of the local dimming power supply module (232) to be boosted, so that dimming lamp beads (220) in a dimming area become bright;

the regional dimming controller (233) controls the power supply of the initial light power supply module (231) to reduce the voltage, so that dimming lamp beads (220) in the dimming region are darkened.

8. The method of claim 4, wherein the method further comprises:

receiving an external control instruction to set a first brightness area, a second brightness area and an end brightness area of a third brightness area … …;

determining the number of high-brightness composite light sources (200a) and the number of dark composite light sources (200b) in the brightness area according to the brightness of the brightness area; the dimming lamp bead (220) in the high-brightness composite light source (200a) is independently connected with the regional dimming power supply module (232); the dimming lamp bead (220) of the dark composite light source (200b) is independently connected with the initial light power module (231); the high-brightness composite light source (200a) and the dark composite light source (200b) are uniformly distributed at intervals;

determining the voltage of the local dimming power supply module (232) according to the brightest brightness region; the voltage level of the initial light power module (231) is determined according to the darkest brightness area.

9. A local dimming display as claimed in claim 4, wherein:

a second liquid crystal dimming layer (400) is arranged on the upper part of the light guide partition (300), and the second liquid crystal dimming layer (400) is overlapped with an original liquid crystal layer of the display;

the second liquid crystal dimming layer (400) is provided with three dimming liquid crystals corresponding to each pixel, and the arrangement direction of the three dimming liquid crystals (410) is vertical to the liquid crystal arrangement direction of each pixel of the original liquid crystal layer.

10. A local dimming display according to claim 9, wherein:

when dimming is required:

acquiring a region defined by an operator on a screen through a touch module;

the voltage at two ends of the liquid crystal in the corresponding area in the second liquid crystal light modulation layer is adjusted, so that the light penetrating through the second liquid crystal light modulation layer (400) is changed in brightness.