TWI887776B - Backlight module of display screen - Google Patents

Abstract

A backlight module of a display screen is provided, and the backlight module includes a circuit board and a light-emitting diode array. The circuit board includes a first column region to j-th column region, and j is a positive integer greater than or equal to 3.The light-emitting diode array is arranged on the circuit board, and the light-emitting diode array includes k light source groups, and the k light source groups include at least a first raw light source group, a i-th raw light source group, a i+1-th raw light source group, and a k-th raw light source group. k is a positive integer greater than or equal to 4, i is a positive integer greater than or equal to 2, and i+1 is less than k. The first raw light source group includes several first raw light-emitting diode modules that are spaced apart from each other. The first raw column light-emitting diode modules are respectively arranged in the first column region to the j-th region. The i-th raw light source group includes several i-th raw light-emitting diode modules that are spaced apart from each other. The i+1-th raw light source group includes several i+1-th raw light-emitting diode modules that are spaced apart from each other. The i-th raw light-emitting diode modules are respectively connected to the i+1-th raw light-emitting diode modules.

Description

Display backlight unit

The present invention relates to a backlight module, in particular to a backlight module for a display screen.

The backlight module of the current liquid crystal screen includes a plurality of LED modules, wherein each LED module is connected in series with a single current source, and each LED module is composed of a plurality of LEDs connected in series with each other. In addition, the LEDs in each LED module are further connected in parallel with a plurality of switch devices.

The user can control each switch device to be in the on state or the off state through the control circuit, so that the current flowing through the LED module changes, thereby achieving the effect of controlling the brightness of the backlight module with a single current source to provide the light source required by the liquid crystal screen.

The technical problem to be solved by the present invention is to provide a backlight module for a display screen in view of the deficiencies of the prior art.

In order to solve the above technical problems, one of the technical solutions adopted by the present invention is to provide a backlight module of a display screen including a circuit board and a light-emitting diode array. The circuit board includes a 1st row area to a jth row area, and j is a positive integer greater than or equal to 3. The light-emitting diode array is arranged on the circuit board, and the light-emitting diode array includes k light source groups, and the k light source groups at least include a 1st column light source group, an i-th column light source group, an i+1th column light source group, and a k-th column light source group, wherein k is a positive integer greater than or equal to 4, i is a positive integer greater than or equal to 2, and i+1 is less than k. The 1st column light source group includes a plurality of 1st column light-emitting diode modules spaced from each other, and the 1st column light-emitting diode modules are respectively located in the 1st row area to the jth row area. The i-th row light source group includes a plurality of i-th row light emitting diode modules spaced from each other, the i+1-th row light source group includes a plurality of i+1-th row light emitting diode modules spaced from each other, and the i-th row light emitting diode modules are respectively connected to the i+1-th row light emitting diode modules.

In order to solve the above technical problems, another technical solution adopted by the present invention is to provide a backlight module for a display screen, including a circuit board and a light emitting diode array. The light emitting diode array is arranged on the circuit board, and the light emitting diode array includes a first column light source group and a second column light source group. Among them, the first column light source group includes a plurality of first column light emitting diode modules spaced from each other, and the second column light source group includes a plurality of second column light emitting diode modules spaced from each other, and one of the first column light emitting diode modules is connected to one of the second column light emitting diode modules.

The specification requirements for the backlight module of the display screen require that the high brightness must reach 1400 nits, while the low brightness must reach below 1nits. Pulse width modulation is a technical means to adjust the brightness of the backlight module, and the limit of reducing the duty cycle of pulse width modulation is about 0.17%. If the brightness of the backlight module is to be reduced to 1nits, the duty cycle of pulse width modulation must be set close to 0.17%. However, when the duty cycle of pulse width modulation is set to close to 0.17%, the backlight module will experience uneven brightness and firefly phenomenon.

One of the beneficial effects of the present invention is that the backlight module of the display screen provided by the present invention can reduce the number of activated LED modules through control means, and the LED modules that are not activated will be evenly dispersed in the backlight module according to the layout of the LED array, thereby, the overall brightness is not limited by the limit of the working cycle of the pulse width modulation, and the backlight module can be operated in a brightness range lower than the normal mode without the occurrence of the firefly phenomenon.

To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only used for reference and description and are not used to limit the present invention.

The following is an explanation of the implementation method of the "backlight module for display screen" disclosed in the present invention through specific concrete embodiments. Technical personnel in this field can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without deviating from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted according to actual sizes. Please note in advance. The following implementation method will further explain the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention.

It should be understood that, although the terms "first", "second", "third", etc. may be used herein to describe various components or signals, these components or signals should not be limited by these terms. These terms are mainly used to distinguish one component from another component, or one signal from another signal. In addition, the term "or" used herein may include any one or more combinations of the associated listed items depending on the actual situation.

FIG1 is a schematic diagram of the circuit layout of the backlight module of the display screen of the present invention. Referring to FIG1 , the backlight module BL includes a circuit board M and a light emitting diode array L. The light emitting diode array L is disposed on the circuit board M. The circuit board M is, for example, a single-sided rigid printed circuit board, a double-sided rigid printed circuit board, a multi-layer rigid printed circuit board, or a flexible printed circuit board, but the present invention is not limited thereto.

The circuit board M includes the 1st row area CL(1) to the jth row area CL(j) arranged side by side, the light emitting diode array L includes k light source groups, and the k light source groups are respectively the 1st column light source group L(1) to the kth column light source group L(k), wherein the i-th column light source group L(i) and the i+1-th column light source group L(i+1) are located between the 1st column light source group L(1) and the k-th column light source group L(k).

The first row light source set L(1) includes a plurality of first row LED modules that are spaced apart from each other, and the first row LED modules are respectively located in the first row region CL(1) to the jth row region CL(j).

The i-th row light source set L(i) includes a plurality of i-th row light emitting diode modules that are spaced apart from each other, and the i-th row light emitting diode modules are respectively located in the first row region CL(1) to the j-th row region CL(j).

The i+1th row light source set L(i+1) comprises a plurality of i+1th row LED modules spaced apart from each other, and the i+1th row LED modules are respectively located in the first row region CL(1) to the jth row region CL(j). The i-th row LED modules are respectively connected to the i+1th row LED modules.

The k-th row light source set L(k) includes a plurality of k-th row light emitting diode modules that are spaced apart from each other, and the k-th row light emitting diode modules are respectively located in the first row region CL(1) to the j-th row region CL(j).

The first row of LED modules to the kth row of LED modules located in the first row region CL(1) are connected to a power source P, and the power source P provides power for the LED module array L to emit light.

It can be seen that the total number of LED modules of the LED array L is k*j and they are arranged on the circuit board 1 according to the structure of k columns and j rows, wherein i is a positive integer greater than or equal to 2, j is a positive integer greater than or equal to 3, k is a positive integer greater than or equal to 4, and i+1 is less than k. By setting the ranges of i, j and k, the overall brightness of the backlight module BL is not limited by the limit of the duty cycle of the pulse width modulation, and the backlight module BL can operate in a brightness range lower than the normal mode without the occurrence of the firefly phenomenon.

FIG2 is a circuit diagram of a first embodiment of a backlight module for a display screen of the present invention. Referring to FIG1 , a backlight module 100 includes a circuit board 1 , a light emitting diode array 2 , a first switch module SW1 and a control circuit 3 .

The circuit board 1 includes a first row region CL(1), a second row region CL(2) and a third row region CL(3) arranged side by side in a direction, and the LED array 2 includes a first row light source group 21, a second row light source group 22, a third row light source group 23 and a fourth row light source group 24. The first row light source group 21 includes a plurality of first row light emitting diode modules 211, 212, 213 spaced apart from each other, any of the first row light emitting diode modules 211, 212, 213 includes a plurality of interconnected light emitting diodes, and the first row light emitting diode modules 211, 212, 213 are respectively located in the first row region CL(1), the second row region CL(2) and the third row region CL(3) of the circuit board 1.

The second row light source group 22 includes a plurality of second row LED modules 221, 222, 223 spaced apart from each other. Any of the second row LED modules 221, 222, 223 includes a plurality of interconnected LEDs, and the second row LED modules 221, 222, 223 are respectively located in the first row area CL(1), the second row area CL(2), and the third row area CL(3) of the circuit board 1.

The third row of light source group 23 includes a plurality of third row of LED modules 231, 232, 233 spaced apart from each other. Any of the third row of LED modules 231, 232, 233 includes a plurality of interconnected LEDs. The positions of the third row of LED modules 231, 232, 233 correspond to the first row area CL(1), the second row area CL(2), and the third row area CL(3) of the circuit board 1, respectively.

The fourth row light source set 24 includes a plurality of fourth row LED modules 241, 242, 243 spaced apart from each other, any of the fourth row LED modules 241, 242, 243 includes a plurality of interconnected LEDs, and the fourth row LED modules 241, 242, 243 are located in the first row region CL(1), the second row region CL(2), and the third row region CL(3) of the circuit board 1, respectively. It can be seen that the total number of LED modules in the LED array 2 is 12, and the 12 LED modules are arranged on the circuit board 1 in a 4-row and 3-row structure.

There is a first distance between the first switch module SW1 and the first row area CL(1), a second distance between the first switch module SW1 and the second row area CL(1), and a third distance between the first switch module SW1 and the third row area CL(3), wherein the third distance is smaller than the second distance, and the second distance is smaller than the first distance.

The first row of LED modules 211, the second row of LED modules 221, the third row of LED modules 231, and the fourth row of LED modules 241 located in the first row region CL(1) are connected to a power source P, and the power source P provides power for the LED module array 2 to emit light.

The first row of LED modules 211 in the first row region CL(1), the second row of LED modules 222 in the second row region CL(2), and the third row of LED modules 233 in the third row region CL(3) are connected in series.

The second row LED module 221 in the first row region CL(1), the third row LED module 232 in the second row region CL(2), and the fourth row LED module 234 in the third row region CL(3) are connected in series.

The third row LED module 231 in the first row region CL(1), the fourth row LED module 242 in the second row region CL(2), and the first row LED module 213 in the third row region CL(3) are connected in series.

The fourth row LED module 241 in the first row region CL(1), the first row LED module 212 in the second row region CL(2), and the second row LED module 223 in the third row region CL(3) are connected in series.

As shown in FIG2 , the first switch module SW1 includes a first field effect transistor and a first diode, and a drain and a source of the first field effect transistor are connected to an anode and a cathode of the first diode, respectively. The first switch module SW1 of this embodiment is only an example, and a mechanical switch module or an electronic switch module with a different circuit structure can also be used on the circuit board 1 to replace the first switch module SW1.

The first switch module SW1 is connected in series with the first column LED module 213 located in the third row area CL(3), wherein the source of the first field effect transistor of the first switch module SW1 is connected to one end of the first column LED module 213, and the gate of the first field effect transistor is connected to the first control terminal CT1 of the control circuit 3.

The control circuit 3 can control the backlight module 100 to operate in a normal mode and a dimming mode, and the normal mode and the dimming mode can correspond to different brightness ranges. For example, the normal mode can make the overall brightness (e.g., average brightness) of the backlight module 100 between 1 nits and 1400 nits (i.e., the limit of the duty cycle of the pulse width modulation), while the dimming mode can make the average brightness of the backlight module 100 less than 1 nits, that is, it can exceed the limit of the duty cycle.

For example, with respect to the structure of FIG. 2 , in the normal mode, the control circuit 3 can control the first switch module SW1 to be in the on state, and in the dimming mode, the control circuit 3 can control the first switch module SW1 to be in the off state. For example, the first switch module SW1 is an N-type field effect transistor (NMOS), and the first control terminal CT1 of the control circuit 3 can output a high-level control signal in the normal mode to make the first switch module SW1 in the on state, and output a low-level control signal in the dimming mode to make the first switch module SW1 in the off state.

When the first switch module SW1 is in the on state in the normal mode, the current output by the power source P passes through the first column LED module 213, the fourth column LED module 242, and the third column LED module 231, so that the first column LED module 213, the fourth column LED module 242, and the third column LED module 231 are activated to emit light.

When the first switch module SW1 is in the off state in the dimming mode, the current output by the power source P cannot pass through the first column LED module 213, the fourth column LED module 242 and the third column LED module 231, so the first column LED module 213, the fourth column LED module 242 and the third column LED module 231 are not activated and do not emit light.

Since the number of activated LED modules is reduced in the dimming mode, and the unactivated LED modules are evenly dispersed in the backlight module 100 according to the layout of the LED array 2, the overall brightness is not limited by the duty cycle limit of the pulse width modulation, and the backlight module 100 can operate in a brightness range lower than that of the normal mode without the occurrence of the firefly phenomenon.

The number of light source groups of the LED array 2 in the first embodiment and the number of LED modules included in each light source group are merely examples, and the present invention is not limited thereto.

In other embodiments, the circuit board 1 may include a 1st row region, a 2nd row region, a 3rd row region, and a 4th row region arranged in parallel along a direction, the LED array 2 may include a 1st row light source group, a 2nd row light source group, a 3rd row light source group, a 4th row light source group, and a 5th row light source group, and any one of the 1st row light source group, the 2nd row light source group, the 3rd row light source group, the 4th row light source group, and the 5th row light source group includes four LED modules. Therefore, the total number of LED modules in the LED array 2 may be 20, and these 20 LED modules are arranged on the circuit board 1 in a 5-row and 4-row structure. As for the layout rules of the 20 LED modules on the circuit board 1, refer to the layout rules of the 12 LED modules on the circuit board 1 in the first embodiment.

For example, the first row of LED modules located in the fourth row of the circuit board 1 is connected to the fifth row of LED modules located in the third row, the first row of LED modules located in the third row is connected to the fifth row of LED modules located in the second row, and the first row of LED modules located in the second row is connected to the fifth row of LED modules located in the first row. The first column of LED modules in the first row, the first column of LED modules in the second row, and the first column of LED modules in the third row are respectively connected to the second column of LED modules in the second row, the second column of LED modules in the third row, and the second column of LED modules in the fourth row. The second column of LED modules in the first row, the second column of LED modules in the second row, and the second column of LED modules in the third row are respectively connected to the third column of LED modules in the second row, the third column of LED modules in the third row, and the third column of LED modules in the fourth row. The connection method between other LED modules can be deduced in the same way.

The number of the first switch modules SW1 in the first embodiment is only an example, and the present invention is not limited thereto.

In other embodiments, the number of first switch modules SW1 may be more than one. For example, the number of first switch modules SW1 may be four, and the four first switch modules SW1 are respectively connected in series with the first row of LED modules 213, the second row of LED modules 223, the third row of LED modules 233, and the fourth row of LED modules 243 located in the third row region CL(3). Regarding the control method of the four first switch modules SW1, for example, the four first switch modules SW1 may respectively receive control signals transmitted from four control terminals, or the four first switch modules SW1 may simultaneously receive control signals transmitted from one control terminal.

Fig. 3 is a circuit diagram of a second embodiment of the backlight module of the display screen of the present invention. Comparing the backlight module 200 of Fig. 3 with the backlight module 100 of Fig. 2 , a plurality of second switch modules SW2 are connected near the first row area CL( 1 ) of the circuit board 1 of Fig. 3 .

The second switch modules SW2 are respectively connected in parallel with the first row of LED modules 211, the second row of LED modules 221, the third row of LED modules 231, and the fourth row of LED modules 241 located in the first row region. Each second switch module SW2 includes a second field effect transistor and a second diode, a drain and a source of the second field effect transistor are respectively connected to an anode and a cathode of the second diode, and the gates of the second switch modules SW2 are commonly connected to a second control terminal CT2 of the control circuit 3.

The second switch module SW2 in the second embodiment is only an example, and a mechanical switch module or an electronic switch module with a different circuit structure may also be used on the circuit board 1 to replace the second switch module SW2.

The control circuit 3 can control the backlight module 200 to operate in a normal mode and a dimming mode, and the normal mode and the dimming mode can correspond to different brightness ranges.

For the structure of FIG. 3 , in the normal mode, the control circuit 3 can control each second switch module SW2 to be in the off state. For example, the second switch module SW2 is an N-type field effect transistor (NMOS), and the second control terminal CT2 of the control circuit 3 can output a low-level control signal in the normal mode to make the second switch module SW2 in the off state.

For the structure of FIG. 3 , in the dimming mode, the control circuit 3 can control each second switch module SW2 to be in the on state. For example, the second switch module SW2 is an N-type field effect transistor (NMOS), and the second control terminal CT2 of the control circuit 3 can output a high-level control signal in the dimming mode to make the second switch module SW2 in the on state.

In the normal mode, the second switch modules SW2 located in the first row area CL(1) are all in the cut-off state, and the current output by the power source P passes through the first column LED module 211, the second column LED module 221, the third column LED module 231 and the fourth column LED module 241 located in the first row area CL(1), so that the first column LED module 211, the second column LED module 221, the third column LED module 231 and the fourth column LED module 241 are activated to emit light.

In the dimming mode, the second switch modules SW2 located in the first row area CL(1) are all in the on state, and the current output by the power source P passes through the second switch modules SW2 located in the first row area CL(1), but does not pass through the first column LED module 211, the second column LED module 221, the third column LED module 231, and the fourth column LED module 241 located in the first row area CL(1). In this way, the first column LED module 211, the second column LED module 221, the third column LED module 231, and the fourth column LED module 241 located in the first row area CL(1) are not activated and do not emit light.

Since the number of activated LED modules is reduced in the dimming mode, and the unactivated LED modules are evenly dispersed in the backlight module 200 according to the layout of the LED array 2, the overall brightness is not limited by the duty cycle limit of the pulse width modulation, and the backlight module 200 can operate in a brightness range lower than the normal mode without the occurrence of the firefly phenomenon.

Regarding the control method of the four second switch modules SW2, in addition to the four second switch modules SW2 simultaneously receiving a control signal transmitted by a control terminal, the four second switch modules SW2 can also respectively receive multiple control signals transmitted by multiple control terminals.

The number of the second switch modules SW2 in the second embodiment is only an example. In other embodiments, the number of the second switch module SW2 may be one. For example, the second switch module SW2 may be connected in parallel to any one of the first column LED module 211, the second column LED module 221, the third column LED module 231, and the fourth column LED module 241 located in the first row region CL(1).

Fig. 4 is a circuit diagram of a third embodiment of the backlight module of the display screen of the present invention. Referring to Fig. 4, a plurality of first switch modules SW1 are connected near the third row area CL(3) of the circuit board 1 of the backlight module 300, and a plurality of second switch modules SW2 are connected near the first row area CL(1) of the circuit board 1.

The first switch modules SW1 are connected in series with the first row of LED modules 213, the second row of LED modules 223, the third row of LED modules 233, and the fourth row of LED modules 243 located in the third row region CL(3). The second switch modules SW2 are connected in parallel with the first row of LED modules 211, the second row of LED modules 221, the third row of LED modules 231, and the fourth row of LED modules 241 located in the first row region CL(1).

The gates of the first field effect transistors of the first switch modules SW1 are respectively connected to a third control terminal CT3, a fourth control terminal CT4, a fifth control terminal CT5 and a sixth control terminal CT6 of the control circuit 3. The gates of the second field effect transistors of the second switch modules SW2 are commonly connected to a seventh control terminal CT7 of the control circuit 3.

4 , the control circuit 3 can control the backlight module 300 to operate in the general mode, the first dimming mode, the second dimming mode and the third dimming mode, and the general mode, the first dimming mode, the second dimming mode and the third dimming mode can correspond to different brightness ranges.

With respect to the structure of FIG. 4 , in a normal mode, the control circuit 3 can control each first switch module SW1 to be in an on state and control each second switch module SW2 to be in an off state.

In the first dimming mode, the control circuit 3 can control the two first switch modules SW1 connected to the third control terminal CT3 and the fourth control terminal CT4 to be in the cut-off state. At this time, the current output by the power source P cannot pass through the first row of LED modules 213 located in the third row area CL(3), the fourth row of LED modules 242 located in the second row area CL(2), the second row of LED modules 223 located in the third row area CL(3), and the first row of LED modules 212 located in the second row area CL(2). Therefore, the first column LED module 213 located in the third row region CL(3), the fourth column LED module 242 located in the second row region CL(2), the second column LED module 223 located in the third row region CL(3), and the first column LED module 212 located in the second row region CL(2) are not activated and do not emit light.

In the second dimming mode, the control circuit 3 can control the two first switch modules SW connected to the fifth control terminal CT5 and the sixth control terminal CT6 to be in the cut-off state. At this time, the current output by the power source P cannot pass through the third row of the LED module 233 located in the third row area CL(3), the second row of the LED module 222 located in the second row area CL(2), the fourth row of the LED module 243 located in the third row area CL(3), and the third row of the LED module 232 located in the second row area CL(2). Therefore, the 3rd column LED module 233 located in the 3rd row region CL(3), the 2nd column LED module 222 located in the 2nd row region CL(2), the 4th column LED module 243 located in the 3rd row region CL(3), and the 3rd column LED module 232 located in the 2nd row region CL(2) are not activated and do not emit light.

In the third dimming mode, the control circuit 3 can be connected to the second switch modules SW2 of the seventh control terminal CT7 in the on state. At this time, the current output by the power source P directly passes through the second switch modules SW2, and does not pass through the first column of LED modules 211, the second column of LED modules 221, the third column of LED modules 231, and the fourth column of LED modules 241 located in the first row area CL(1). Therefore, the first column of LED modules 211, the second column of LED modules 221, the third column of LED modules 231, and the fourth column of LED modules 241 located in the first row area CL(1) are not activated and do not emit light.

Since the number of activated LED modules is reduced in the first dimming mode, the second dimming mode and the third dimming mode, and the unactivated LED modules are evenly dispersed in the backlight module 300 according to the layout of the LED array 2, the overall brightness is not limited by the limit of the working cycle of the pulse width modulation, and the backlight module 300 can operate in a brightness range lower than the normal mode without the occurrence of the firefly phenomenon.

FIG5 is a circuit diagram of a fourth embodiment of the backlight module of the display screen of the present invention. Referring to FIG5, a first switch module SW1 is connected near the third row area CL(3) of the circuit board 1 of the backlight module 500, two second switch modules SW2 are connected near the first row area CL(1) of the circuit board 1, and a third switch module SW3 is connected to the second row area CL(2) of the circuit board 1.

The first switch module SW1 is connected in parallel to the first row of LED modules 213 located in the third row region CL(3). The second switch modules SW2 are connected in parallel to the first row of LED modules 211 and the fourth row of LED modules 241 located in the first row region CL(1). The third switch module SW3 is connected in parallel to the third row of LED modules 232 located in the second row region CL(2).

The third switch module SW3 includes a third field effect transistor and a third diode, and a drain and a source of the third field effect transistor are respectively connected to an anode and a cathode of the third diode. The third switch module SW3 in the fourth embodiment is only an example, and the circuit board 1 can also use a mechanical switch module or an electronic switch module with a different circuit structure to replace the third switch module SW3.

The gate of the first field effect transistor of the first switch module SW1 , the gates of the second field effect transistors of the second switch modules SW2 , and the gate of the third field effect transistor of the third switch module SW3 are commonly connected to an eighth control terminal CT8 of the control circuit 3 .

With respect to the structure of FIG. 5 , the control circuit 3 can control the backlight module 400 to operate in a normal mode and a dimming mode, and the normal mode and the dimming mode can correspond to different brightness ranges.

In the normal mode, the control circuit 3 can control the first switch module SW1, the second switch modules SW2 and the third switch module SW3 connected to the eighth control terminal CT8 to be in the cut-off state. At this time, the current output by the power source P can pass through the first row of the LED module 211 located in the first row area CL(1), the fourth row of the LED module 241 located in the first row area CL(1), the third row of the LED module 232 located in the second row area CL(1) and the first row of the LED module 213 located in the third row area CL(3).

In the dimming mode, the control circuit 3 can control the first switch module SW1, the second switch modules SW2 and the third switch module SW3 connected to the eighth control terminal CT8 to be in the on state. At this time, the current output by the power source P directly passes through the first switch module SW1, the second switch modules SW2 and the third switch module SW3, and does not pass through the first row of the LED module 211 located in the first row area CL(1), the fourth row of the LED module 241 located in the first row area CL(1), the third row of the LED module 232 located in the second row area CL(1) and the first row of the LED module 213 located in the third row area CL(3). Therefore, the first column LED module 211 located in the first row region CL(1), the fourth column LED module 241 located in the first row region CL(1), the third column LED module 232 located in the second row region CL(1), and the first column LED module 213 located in the third row region CL(3) are not activated and do not emit light.

Since the number of activated LED modules is reduced in the dimming mode, and the unactivated LED modules are evenly dispersed in the backlight module 400 according to the layout of the LED array 2, the overall brightness is not limited by the duty cycle limit of the pulse width modulation, and the backlight module 400 can operate in a brightness range lower than the normal mode without the occurrence of the firefly phenomenon.

[Beneficial Effects of Embodiments]

One of the beneficial effects of the present invention is that the backlight module of the display screen provided by the present invention reduces the number of activated LED modules in the dimming mode, and the LED modules that are not activated are evenly dispersed in the backlight module according to the layout of the LED array, thereby, the overall brightness is not limited by the limit of the working cycle of the pulse width modulation, and the backlight module can operate in a brightness range lower than the normal mode without the occurrence of the firefly phenomenon.

The contents disclosed above are only preferred feasible embodiments of the present invention and are not intended to limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made using the contents of the specification and drawings of the present invention are included in the scope of the patent application of the present invention.

BL, 100, 200, 300, 400: backlight module L: LED array L(1): 1st column light source group L(i): ith column light source group L(i+1): ith+1st column light source group L(k): ith kth column light source group M: circuit board CL(1): 1st row area CL(2): 2nd row area CL(3): 3rd row area CL(j): jth row area 1: circuit board 2: LED array 21: 1st column light source group 22: 2nd column light source group 23: 3rd column light source group 24: 4th column light source group 211, 212, 213: 1st column LED module 221, 222, 223: 2nd column LED module 231, 232, 233: 3rd row LED module 241, 242, 243: 4th row LED module SW1: 1st switch module SW2: 2nd switch module SW3: 3rd switch module P: power supply 3: control circuit CT1: 1st control terminal CT2: 2nd control terminal CT3: 3rd control terminal CT4: 4th control terminal CT5: 5th control terminal CT6: 6th control terminal CT7: 7th control terminal CT8: 8th control terminal

FIG. 1 is a schematic diagram of the circuit layout of the backlight module of the display screen of the present invention.

FIG. 2 is a circuit diagram of a first embodiment of a backlight module for a display screen of the present invention.

FIG. 3 is a circuit diagram of a second embodiment of a backlight module for a display screen of the present invention.

FIG. 4 is a circuit diagram of a third embodiment of a backlight module for a display screen of the present invention.

FIG. 5 is a circuit diagram of a fourth embodiment of a backlight module for a display screen according to the present invention.

100: Backlight module

1: Circuit board

CL(1): 1st row area

CL(2): 2nd row area

CL(3): 3rd row area

2: LED array

21: 1st row light source group

22: 2nd row light source group

23: The third row of light source groups

24: 4th row light source group

211, 212, 213: The first row of LED modules

221, 222, 223: The second row of LED modules

231, 232, 233: The third row of LED modules

241, 242, 243: 4th row of LED modules

SW1: First switch module

P: Power supply

3: Control circuit

CT1: First control terminal

Claims (11)

A backlight module for a display screen, comprising: a circuit board, comprising a 1st row region to a jth row region, wherein j is a positive integer greater than or equal to 3; and a light-emitting diode array, disposed on the circuit board, wherein the light-emitting diode array comprises k light source groups, wherein the k light source groups at least comprise a 1st column light source group, an i-th column light source group, an i+1th column light source group, and a k-th column light source group, wherein k is a positive integer greater than or equal to 4, i is a positive integer greater than or equal to 2, and i+1 is less than k; the 1st column light source group comprises a plurality of 1st column light-emitting diode modules spaced from each other, wherein the 1st column light-emitting diode modules are respectively located in the 1st row region to the jth row region; The i-th column light source group includes a plurality of i-th column light-emitting diode modules spaced apart from each other, and the i+1-th column light source group includes a plurality of i+1-th column light-emitting diode modules spaced apart from each other, and the i-th column light-emitting diode modules are respectively connected to the i+1-th column light-emitting diode modules. A backlight module for a display screen as described in claim 1, wherein the k-th column light source group comprises a plurality of k-th column light-emitting diode modules spaced apart from each other, the k-th column light-emitting diode modules are respectively located in the 1st row region to the j-th row region, the 1st column light-emitting diode modules located in the 2nd row region to the j-th row region are respectively connected to the k-th column light-emitting diode modules located in the 1st row region to the j-1th row region; one of the 1st column light-emitting diode modules is connected to a first switch module, and the first switch module is connected to a first control terminal. In the backlight module of the display screen as described in claim 1, the first row of light-emitting diode modules corresponding to the j-th row area is connected to a first switch module, and the first switch module is connected to a first control terminal. The backlight module of the display screen as described in claim 3, wherein the first switch module comprises a first field effect transistor and a first diode, an anode and a cathode of the first diode are respectively connected to a drain and a source of the first field effect transistor, and a gate of the first field effect transistor is connected to the first control terminal; when the first switch module is connected to the first row of the first field effect transistor in the j-th row area, the first field effect transistor is connected to the first control terminal; When the photodiode modules are connected in series, the source of the first field effect transistor is connected to one end of the first column of the light-emitting diode module located in the j-th row area; when the first switch module is connected in parallel with the first column of the light-emitting diode module located in the j-th row area, the drain and the source of the first field effect transistor are respectively connected to the two ends of the first column of the light-emitting diode module located in the j-th row area. In the backlight module of the display screen as described in claim 1, the first row of light-emitting diode modules located in the first row area is connected to a second switch module, and the second switch module is connected to a second control terminal. A backlight module for a display screen as described in claim 5, wherein the second switch module includes a second field effect transistor and a second diode, a gate of the second field effect transistor is connected to the second control terminal, an anode and a cathode of the second diode are respectively connected to a drain and a source of the second field effect transistor, and the drain and the source of the second field effect transistor are respectively connected to two ends of the first column of light-emitting diode modules located in the first row area. The backlight module of the display screen as described in claim 1, wherein the first column of light-emitting diode modules located in the j-th row area is connected to a first switch module, and the first switch module is connected to a first control terminal; the first column of light-emitting diode modules located in the first row area is connected in parallel to a second switch module, and the second switch module is connected to a second control terminal. A backlight module for a display screen as described in claim 7, wherein the first switch module comprises a first field effect transistor and a first diode, a gate of the first field effect transistor is connected to the first control terminal, an anode and a cathode of the first diode are respectively connected to a drain and a source of the first field effect transistor, and the source of the first field effect transistor is connected to the first row of light-emitting diodes located in the jth row region. The first control terminal is connected to the first body module; the second switch module includes a second field effect transistor and a second diode, a gate of the second field effect transistor is connected to the second control terminal, an anode and a cathode of the second diode are respectively connected to a drain and a source of the second field effect transistor, and the drain and the source of the second field effect transistor are respectively connected to two ends of the first column of light-emitting diode modules located in the first row area. A backlight module for a display screen as described in claim 1, wherein the first column of light-emitting diode modules located in the j-th row region is connected to a first switch module, and the first switch module is connected to a first control terminal; the first column of light-emitting diode modules located in the 1st row region is connected to a second switch module, and the second switch module is connected to the first control terminal; an i-th row region is provided between the 1st row region and the j-th row region of the circuit board, i is a positive integer less than j, and the first column of light-emitting diode modules located in the i-th row region is connected to a third switch module, and the third switch module is connected to the first control terminal. A backlight module for a display screen as described in claim 9, wherein the first switch module comprises a first field effect transistor and a first diode, a gate of the first field effect transistor is connected to the first control terminal, an anode and a cathode of the first diode are respectively connected to a drain and a source of the first field effect transistor, the drain and the source of the first field effect transistor are respectively connected to two ends of the first column of light-emitting diode modules located in the j-th row area; the second switch module comprises a second field effect transistor and a second diode, a gate of the second field effect transistor is connected to the first control terminal, a cathode of the second diode is respectively connected to a drain and a source of the first field effect transistor, and the drain and the source of the first field effect transistor are respectively connected to two ends of the first column of light-emitting diode modules located in the j-th row area. An anode and a cathode are respectively connected to a drain and a source of the second field effect transistor, and the drain and the source of the second field effect transistor are respectively connected to two ends of the first column of light-emitting diode modules located in the first row area; the third switch module includes a third field effect transistor and a third diode, a gate of the third field effect transistor is connected to the first control end, an anode and a cathode of the third diode are respectively connected to a drain and a source of the third field effect transistor, and the drain and the source of the third field effect transistor are respectively connected to two ends of the third column of light-emitting diode modules located in the second row area. A backlight module for a display screen comprises: a circuit board; and a light-emitting diode array disposed on the circuit board, the light-emitting diode array comprising a first-row light source group and a second-row light source group; wherein the first-row light source group comprises a plurality of first-row light-emitting diode modules spaced apart from each other, the second-row light source group comprises a plurality of second-row light-emitting diode modules spaced apart from each other, and one of the first-row light-emitting diode modules is connected to one of the second-row light-emitting diode modules.