A light-emitting panel, backlight module and liquid crystal display device

Abstract

The present invention discloses a light-emitting panel, a backlight module and a liquid crystal display device. By setting a gating circuit electrically connected to a light-emitting group, in a first time period, under the control of the gating circuit, a first light-emitting area of ​​the light-emitting group is electrically connected to a first constant current module and a second light-emitting area of ​​the light-emitting group is electrically connected to a second constant current module; in a second time period, under the control of the gating circuit, the first light-emitting area of ​​the light-emitting group is electrically connected to the second constant current module and the second light-emitting area of ​​the light-emitting group is electrically connected to the first constant current module.

Description

Technical Field

[0001] The present invention relates to the technical field of backlight, and in particular to a light-emitting panel, a backlight module and a liquid crystal display device. Background Art

[0002] A liquid crystal display device includes a liquid crystal display panel and a backlight module. Existing backlight modules mostly use LEDs as light sources. In order to reduce the power consumption of the backlight, a backlight local dimming technology is usually used to drive the LED to emit light, which can significantly reduce the energy consumption of the LED and improve the display quality. Summary of the invention

[0003] The embodiments of the present invention provide a light emitting panel, a backlight module and a liquid crystal display device, which are used to solve the problem of uneven light emitting brightness of different backlight partitions in the prior art.

[0004] An embodiment of the present invention provides a light-emitting panel, comprising a plurality of light-emitting groups, each of the light-emitting groups comprising a first light-emitting area and a second light-emitting area arranged adjacent to each other, and any one of the first light-emitting area and the second light-emitting area comprising a plurality of light-emitting elements electrically connected;

[0005] It also includes: a gating circuit electrically connected to each of the light-emitting groups in a one-to-one correspondence, and a first constant current module and a second constant current module electrically connected to each of the gating circuits; wherein different light-emitting groups are electrically connected to different first constant current modules, and different light-emitting groups are electrically connected to different second constant current modules; the light-emitting groups are configured to be electrically connected to the first constant current module and the second constant current module under the control of the gating circuit;

[0006] Wherein, in a first time period, under the control of the gating circuit, the first light-emitting area is electrically connected to the first constant current module and the second light-emitting area is electrically connected to the second constant current module; in a second time period, under the control of the gating circuit, the first light-emitting area is electrically connected to the second constant current module and the second light-emitting area is electrically connected to the first constant current module.

[0007] Optionally, in the above-mentioned light-emitting panel provided by an embodiment of the present invention, the plurality of light-emitting groups are arranged along a row direction.

[0008] Optionally, in the above-mentioned light-emitting panel provided in an embodiment of the present invention, any one of the first light-emitting area and the second light-emitting area includes multiple parallel branches, each of the parallel branches includes at least two light-emitting elements connected in series, and the first end of each parallel branch is electrically connected to the driving voltage end.

[0009] Optionally, in the above-mentioned light-emitting panel provided by the embodiment of the present invention, the gating circuit includes a first switch transistor, a second switch transistor, a third switch transistor and a fourth switch transistor; wherein,

[0010] The gate of the first switch transistor and the gate of the second switch transistor are both electrically connected to the first control signal line, the first electrode of the first switch transistor is electrically connected to the second ends of the plurality of parallel branches in the first light-emitting area, the first electrode of the second switch transistor is electrically connected to the second ends of the plurality of parallel branches in the second light-emitting area, the second electrode of the first switch transistor is electrically connected to the first constant current module, and the second electrode of the second switch transistor is electrically connected to the second constant current module;

[0011] The gate of the third switch transistor and the gate of the fourth switch transistor are both electrically connected to the second control signal line, the first electrode of the third switch transistor is electrically connected to the second ends of the multiple parallel branches in the second light-emitting area, the first electrode of the fourth switch transistor is electrically connected to the second ends of the multiple parallel branches in the first light-emitting area, the second electrode of the third switch transistor is electrically connected to the first constant current module, and the second electrode of the fourth switch transistor is electrically connected to the second constant current module.

[0012] Optionally, in the above-mentioned light-emitting panel provided by an embodiment of the present invention, the frequency of the first control signal on the first control signal line and the frequency of the second control signal on the second control signal line are both greater than 1 KHz.

[0013] Optionally, in the above-mentioned light-emitting panel provided in an embodiment of the present invention, the first switch transistor, the second switch transistor, the third switch transistor and the fourth switch transistor are all N-type transistors, or the first switch transistor, the second switch transistor, the third switch transistor and the fourth switch transistor are all P-type transistors.

[0014] Optionally, in the above-mentioned light-emitting panel provided by an embodiment of the present invention, the first time period and the second time period have the same length.

[0015] Optionally, in the above-mentioned light-emitting panel provided in an embodiment of the present invention, when the first light-emitting area and the second light-emitting area present the same light-emitting brightness, the first constant current module generates the same current signal in the first time period and the second time period, and the second constant current module generates the same current signal in the first time period and the second time period.

[0016] Correspondingly, an embodiment of the present invention further provides a backlight module, comprising any one of the above-mentioned light-emitting panels provided by the embodiment of the present invention.

[0017] Correspondingly, an embodiment of the present invention further provides a liquid crystal display device, comprising the above-mentioned backlight module provided by an embodiment of the present invention.

[0018] Beneficial effects of the present invention:

[0019] The light-emitting panel, backlight module and liquid crystal display device provided by the embodiment of the present invention are provided with a gating circuit electrically connected to the light-emitting group. In the first time period, under the control of the gating circuit, the first light-emitting area of ​​the light-emitting group is electrically connected to the first constant current module and the second light-emitting area of ​​the light-emitting group is electrically connected to the second constant current module; in the second time period, under the control of the gating circuit, the first light-emitting area of ​​the light-emitting group is electrically connected to the second constant current module and the second light-emitting area of ​​the light-emitting group is electrically connected to the first constant current module. The currents flowing through the first light-emitting area and the second light-emitting area of ​​the same light-emitting group are alternately controlled by the first constant current module and the second constant current module, so that the brightness consistency of the first light-emitting area and the second light-emitting area of ​​the same light-emitting group can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of an existing light-emitting panel;

[0021] Figure 2 for Figure 1 A schematic diagram of the lighting effect of two adjacent partitions in the light-emitting panel shown;

[0022] Figure 3 A schematic diagram of the structure of a light-emitting panel provided by an embodiment of the present invention;

[0023] Figure 4 A schematic diagram of the structure of another light-emitting panel provided by an embodiment of the present invention;

[0024] Figure 5 for Figure 4 The working timing diagram of the light-emitting panel shown;

[0025] Figure 6 for Figure 4 A schematic diagram of a current path of a light-emitting group in a first time period is shown;

[0026] Figure 7 for Figure 4 A schematic diagram of a current path of a light-emitting group in a second time period is shown;

[0027] Figure 8 for Figure 4 A schematic diagram of the lighting effects of a first light-emitting area and a second light-emitting area in a light-emitting group is shown. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clear, the specific implementation methods of a light-emitting panel, a backlight module and a liquid crystal display device provided by the embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0029] The thickness and shape of each film layer in the drawings do not reflect the actual proportion of the light-emitting panel, and the purpose is only to illustrate the content of the present invention.

[0030] In recent years, Mini LED has been favored for its high brightness and high contrast performance, and its application market has been continuously expanding. Among them, Mini LED is used as the light source of the backlight module. In order to reduce power consumption, the backlight module can adopt local dimming (backlight area adjustment technology), such as Figure 1 As shown in the figure, two partitions (Block1 and Block2) are taken as an example. Each partition includes at least one Mini LED, and the number and connection method of the Mini LEDs included in each partition are the same. The positive electrode (+) of each partition is directly connected to the driving voltage terminal V LED Electrical connection, the negative pole of each partition's LED is connected to the corresponding constant current module, which is used to control the current flowing through the electrical path of the corresponding partition. When each partition presents the same brightness, since the performance of each constant current module cannot be absolutely consistent, the current of the electrical path of different partitions is inconsistent, resulting in a decrease in the brightness uniformity of different partitions in the backlight module, such as Figure 2 As shown, Figure 2 The left side of Figure 1 The brightness of the middle partition Block1 is Figure 1 From the luminous brightness of the middle partition Block 2, it can be seen that there is a difference in brightness between the two partitions.

[0031] In view of this, an embodiment of the present invention provides a light-emitting panel, such as Figure 3 As shown, it includes a plurality of light-emitting groups 1 (taking two light-emitting groups 1 as an example), each light-emitting group 1 includes a first light-emitting area 11 and a second light-emitting area 12 arranged adjacent to each other, and any one of the first light-emitting area 11 and the second light-emitting area 12 includes a plurality of light-emitting elements L that are electrically connected;

[0032] It also includes: a gating circuit 2 electrically connected to each light-emitting group 1 in a one-to-one correspondence, and a first constant current module 3 and a second constant current module 4 electrically connected to each gating circuit 2; wherein different light-emitting groups 1 are electrically connected to different first constant current modules 3, and different light-emitting groups 1 are electrically connected to different second constant current modules 4; the light-emitting group 1 is configured to be electrically connected to the first constant current module 3 and the second constant current module 4 under the control of the gating circuit 2;

[0033] Among them, in the first time period, under the control of the gating circuit 2, the first light-emitting area 11 is electrically connected to the first constant current module 3 and the second light-emitting area 12 is electrically connected to the second constant current module 4; in the second time period, under the control of the gating circuit 2, the first light-emitting area 11 is electrically connected to the second constant current module 4 and the second light-emitting area 12 is electrically connected to the first constant current module 3.

[0034] The above-mentioned light-emitting panel provided by the embodiment of the present invention is provided with a gating circuit electrically connected to the light-emitting group. In the first time period, under the control of the gating circuit, the first light-emitting area of ​​the light-emitting group is electrically connected to the first constant current module and the second light-emitting area of ​​the light-emitting group is electrically connected to the second constant current module; in the second time period, under the control of the gating circuit, the first light-emitting area of ​​the light-emitting group is electrically connected to the second constant current module and the second light-emitting area of ​​the light-emitting group is electrically connected to the first constant current module. In this way, the first light-emitting area and the second light-emitting area in the same light-emitting group are controlled by the first constant current module and the second constant current module at the same time, which can improve the brightness consistency of the first light-emitting area and the second light-emitting area of ​​the same light-emitting group.

[0035] Optionally, the light emitting element of the embodiment of the present invention may be a light emitting diode, such as a Mini LED (English: Mini Light Emitting Diode) or a Micro LED (English: Micro Light Emitting Diode).

[0036] Optionally, the first constant current module and the second constant current module may be an IDAC current source or a VDAC voltage source.

[0037] In a specific implementation, in the above-mentioned light-emitting panel provided in the embodiment of the present invention, as Figure 3 As shown, a plurality of light-emitting groups 1 may be arranged along a row direction X. Embodiments of the present invention Figure 3 Only two light-emitting groups are shown. Of course, in actual implementation, in order to achieve more precise zoning control, the number of light-emitting groups can be set as needed.

[0038] In a specific implementation, in the above-mentioned light-emitting panel provided in the embodiment of the present invention, as Figure 3 As shown, any one of the first light-emitting area 11 and the second light-emitting area 12 may include multiple parallel branches (taking three parallel branches as an example), each parallel branch includes at least two light-emitting elements L connected in series (taking three light-emitting elements L in series as an example), and the first end of each parallel branch is connected to the driving voltage end V LED In this way, each first light-emitting area 11 and each second light-emitting area 12 can emit light independently, realize zone control, and reduce power consumption.

[0039] It should be noted that if Figure 3As shown, the first constant current module 3 and the second constant current module 4 are also electrically connected to the ground signal terminal.

[0040] In a specific implementation, in the above-mentioned light-emitting panel provided in the embodiment of the present invention, as Figure 4 As shown, the gating circuit 2 may include a first switch transistor T1, a second switch transistor T2, a third switch transistor T3 and a fourth switch transistor T4; wherein,

[0041] The gate of the first switch transistor T1 and the gate of the second switch transistor T2 are both electrically connected to the first control signal line 5, the first electrode of the first switch transistor T1 is electrically connected to the second ends of the plurality of parallel branches in the first light-emitting area 11, the first electrode of the second switch transistor T2 is electrically connected to the second ends of the plurality of parallel branches in the second light-emitting area 12, the second electrode of the first switch transistor T1 is electrically connected to the first constant current module 3, and the second electrode of the second switch transistor T2 is electrically connected to the second constant current module 4;

[0042] The gate of the third switch transistor T3 and the gate of the fourth switch transistor T4 are both electrically connected to the second control signal line 6, the first electrode of the third switch transistor T3 is electrically connected to the second ends of the multiple parallel branches in the second light-emitting area 12, the first electrode of the fourth switch transistor T4 is electrically connected to the second ends of the multiple parallel branches in the first light-emitting area 11, the second electrode of the third switch transistor T3 is electrically connected to the first constant current module 3, and the second electrode of the fourth switch transistor T4 is electrically connected to the second constant current module 4.

[0043] like Figure 4 As shown, in the first time period, under the control of the first control signal line 5, the first switch transistor T1 and the second switch transistor T2 can be controlled to be turned on, and under the control of the second control signal line 6, the third switch transistor T3 and the fourth switch transistor T4 can be controlled to be turned off, so that the sum of the currents flowing through the multiple parallel branches of the first light-emitting area 11 is controlled by the first constant current module 3, and the sum of the currents flowing through the multiple parallel branches of the second light-emitting area 12 is controlled by the second constant current module 3; in the second time period, under the control of the first control signal line 5, the first switch transistor T1 and the second switch transistor T2 can be controlled to be turned on, and under the control of the second control signal line 6, the third switch transistor T3 and the fourth switch transistor T4 can be controlled to be turned off, so that the sum of the currents flowing through the multiple parallel branches of the first light-emitting area 11 is controlled by the first constant current module 3, and the sum of the currents flowing through the multiple parallel branches of the second light-emitting area 12 is controlled by the second constant current module 3. The body tube T2 is turned off, and under the control of the second control signal line 6, the third switch transistor T3 and the fourth switch transistor T4 can be controlled to be turned on, so that the sum of the currents flowing through the multiple parallel branches of the first light-emitting area 11 is controlled by the second constant current module 4, and the sum of the currents flowing through the multiple parallel branches of the second light-emitting area 12 is controlled by the first constant current module 3; in this way, the currents flowing through the first light-emitting area 11 and the second light-emitting area 12 of the same light-emitting group 1 are alternately controlled by the first constant current module 3 and the second constant current module 4, which can improve the brightness consistency of the first light-emitting area 11 and the second light-emitting area 12 of the same light-emitting group 1.

[0044] In a specific implementation, in order to prevent the flickering problem when different light-emitting areas of the same light-emitting group are alternately controlled by two constant current modules, in the above-mentioned light-emitting panel provided in an embodiment of the present invention, Figure 4 As shown, the frequency of the first control signal on the first control signal line 5 and the frequency of the second control signal on the second control signal line 6 can be set to be greater than 1KHz. In this way, the human eye cannot see the flicker phenomenon. In this way, the first time period and the second time period in the embodiment of the present invention respectively include multiple sub-segments. For example, the first time period is the cumulative time when the first control signal is at a valid level (for example, a high level) within a frame time, that is, the sum of N t1s, and the second time period is the cumulative time when the second control signal is at a valid level (for example, a high level) within a frame time, that is, the sum of N t2s.

[0045] In specific implementation, in the above-mentioned luminous panel provided by the embodiment of the present invention, the first time period and the second time period have the same length, so as to ensure that different luminous areas of the same group are controlled by different constant current modules for the same time, further improving the uniformity of luminous brightness.

[0046] In a specific implementation, in the above-mentioned light-emitting panel provided in the embodiment of the present invention, as Figure 4 As shown, when the first light-emitting area 11 and the second light-emitting area 12 present the same light-emitting brightness, the first constant current module 3 generates the same current signal in the first time period and the second time period, and the second constant current module 4 generates the same current signal in the first time period and the second time period.

[0047] In a specific implementation, in the above-mentioned light-emitting panel provided in the embodiment of the present invention, as Figure 4 As shown, the first switch transistor T1, the second switch transistor T2, the third switch transistor T3 and the fourth switch transistor T4 are all N-type transistors, so that the manufacturing process of the switch transistors can be unified, and the N-type transistor is turned on under the action of a high level and is cut off under the action of a low level. Of course, the first switch transistor T1, the second switch transistor T2, the third switch transistor T3 and the fourth switch transistor T4 can also be P-type transistors, and the P-type transistor is turned on under the action of a low level and is cut off under the action of a high level.

[0048] Below Figure 4 Taking a light-emitting group 1 in the light-emitting panel as an example, the lighting principle of the light-emitting element L provided in the embodiment of the present invention is described. The working timing diagram is shown in FIG. Figure 5 shown.

[0049] In the time period t1: the potential of the first control signal on the first control signal line 5 is high, the potential of the second control signal on the second control signal line 6 is low, the first switch transistor T1 and the second switch transistor T2 are turned on, the third switch transistor T3 and the fourth switch transistor T4 are turned off, the first constant current module 3 controls the sum of the currents flowing through the multiple parallel branches of the first light-emitting area 11 to be the first current I1 through the turned-on first switch transistor T1, the second constant current module 4 controls the sum of the currents flowing through the multiple parallel branches of the second light-emitting area 12 to be the second current I2 through the turned-on second switch transistor T2, and the current flow paths of the first current I1 and the second current I2 are as follows: Figure 6 shown.

[0050] In the time period t2: the potential of the first control signal on the first control signal line 5 is low, the potential of the second control signal on the second control signal line 6 is high and low, the first switch transistor T1 and the second switch transistor T2 are turned off, the third switch transistor T3 and the fourth switch transistor T4 are turned on, the first constant current module 3 controls the sum of the currents flowing through the multiple parallel branches of the second light-emitting area 12 to be the first current I1 through the turned-on third switch transistor T3, the second constant current module 4 controls the sum of the currents flowing through the multiple parallel branches of the first light-emitting area 11 to be the second current I2 through the turned-on fourth switch transistor T4, and the current flow paths of the first current I1 and the second current I2 are as follows: Figure 7 shown.

[0051] Therefore, in Figure 4 In each light-emitting group 1, the first light-emitting area 11 is input with the first current I1 in the first time period (i.e., the sum of multiple t1s), and is input with the second current I2 in the second time period (i.e., the sum of multiple t2s). Figure 8 As shown, Figure 8 The left side of the dotted line is the luminous brightness of the first luminous area 11, and the right side of the dotted line is the luminous brightness of the second luminous area 12. It can be seen that, using the embodiment of the present invention, the brightness of the first luminous area 11 and the second luminous area 12 are consistent.

[0052] Based on the same inventive concept, the embodiment of the present invention further provides a backlight module, including the above-mentioned light-emitting board provided by the embodiment of the present invention. The principle of solving the problem by the backlight module is similar to that of the above-mentioned light-emitting board, so the implementation of the backlight module can refer to the implementation of the above-mentioned light-emitting board, and the repeated parts will not be repeated here.

[0053] Based on the same inventive concept, the embodiment of the present invention further provides a liquid crystal display device, including the above-mentioned backlight module provided by the embodiment of the present invention. The principle of solving the problem by the liquid crystal display device is similar to that of the aforementioned light-emitting panel, so the implementation of the liquid crystal display device can refer to the implementation of the aforementioned light-emitting panel, and the repeated parts will not be repeated here.

[0054] The light-emitting panel, backlight module and liquid crystal display device provided by the embodiment of the present invention are provided with a gating circuit electrically connected to the light-emitting group. In the first time period, under the control of the gating circuit, the first light-emitting area of ​​the light-emitting group is electrically connected to the first constant current module and the second light-emitting area of ​​the light-emitting group is electrically connected to the second constant current module; in the second time period, under the control of the gating circuit, the first light-emitting area of ​​the light-emitting group is electrically connected to the second constant current module and the second light-emitting area of ​​the light-emitting group is electrically connected to the first constant current module. The currents flowing through the first light-emitting area 11 and the second light-emitting area 12 of the same light-emitting group 1 are alternately controlled by the first constant current module 3 and the second constant current module 4, which can improve the brightness consistency of the first light-emitting area 11 and the second light-emitting area 12 of the same light-emitting group 1.

[0055] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A light-emitting panel, characterized in that: comprising a plurality of light-emitting groups, each of the light-emitting groups comprising a first light-emitting area and a second light-emitting area arranged adjacent to each other, and any one of the first light-emitting area and the second light-emitting area comprising a plurality of light-emitting elements electrically connected; It also includes: a gating circuit electrically connected to each of the light-emitting groups in a one-to-one correspondence, and a first constant current module and a second constant current module electrically connected to each of the gating circuits; wherein different light-emitting groups are electrically connected to different first constant current modules, and different light-emitting groups are electrically connected to different second constant current modules; the light-emitting groups are configured to be electrically connected to the first constant current module and the second constant current module under the control of the gating circuit; Wherein, in a first time period, under the control of the gating circuit, the first light-emitting area is electrically connected to the first constant current module and the second light-emitting area is electrically connected to the second constant current module; in a second time period, under the control of the gating circuit, the first light-emitting area is electrically connected to the second constant current module and the second light-emitting area is electrically connected to the first constant current module.

2. The light-emitting panel according to claim 1, characterized in that The plurality of light-emitting groups are arranged along a row direction.

3. The light-emitting panel according to claim 1, characterized in that Any one of the first light-emitting area and the second light-emitting area includes a plurality of parallel branches, each of the parallel branches includes at least two light-emitting elements connected in series, and a first end of each of the parallel branches is electrically connected to a driving voltage end.

4. The light-emitting panel according to claim 3, characterized in that: The gating circuit includes a first switch transistor, a second switch transistor, a third switch transistor and a fourth switch transistor; wherein, The gate of the first switch transistor and the gate of the second switch transistor are both electrically connected to the first control signal line, the first electrode of the first switch transistor is electrically connected to the second ends of the plurality of parallel branches in the first light-emitting area, the first electrode of the second switch transistor is electrically connected to the second ends of the plurality of parallel branches in the second light-emitting area, the second electrode of the first switch transistor is electrically connected to the first constant current module, and the second electrode of the second switch transistor is electrically connected to the second constant current module; The gate of the third switch transistor and the gate of the fourth switch transistor are both electrically connected to the second control signal line, the first electrode of the third switch transistor is electrically connected to the second ends of the multiple parallel branches in the second light-emitting area, the first electrode of the fourth switch transistor is electrically connected to the second ends of the multiple parallel branches in the first light-emitting area, the second electrode of the third switch transistor is electrically connected to the first constant current module, and the second electrode of the fourth switch transistor is electrically connected to the second constant current module.

5. The light-emitting panel according to claim 4, characterized in that: The frequency of the first control signal on the first control signal line and the frequency of the second control signal on the second control signal line are both greater than 1 KHz.

6. The light-emitting panel according to claim 4, characterized in that: The first switch transistor, the second switch transistor, the third switch transistor and the fourth switch transistor are all N-type transistors, or the first switch transistor, the second switch transistor, the third switch transistor and the fourth switch transistor are all P-type transistors.

7. The light-emitting panel according to any one of claims 1 to 6, characterized in that: The first time period and the second time period have the same length.

8. The light-emitting panel according to claim 7, characterized in that: When the first light-emitting area and the second light-emitting area present the same light-emitting brightness, the first constant current module generates the same current signal in the first time period and the second time period, and the second constant current module generates the same current signal in the first time period and the second time period.

9. A backlight module, characterized in that: The invention comprises the light-emitting panel as claimed in any one of claims 1 to 8.

10. A liquid crystal display device, characterized in that: Comprising the backlight module as claimed in claim 9.

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