CN117594016A - Electronic device - Google Patents

Abstract

An electronic device comprises a display panel, a backlight source, an ambient light sensor and a controller. The backlight is arranged under the display panel and comprises a plurality of light emitting units. The ambient light sensor is used for sensing ambient light brightness. The controller is electrically connected with the display panel, the backlight source and the ambient light sensor, and is used for judging a general mode or a low-brightness mode according to the sensing result of the ambient light sensor, wherein the white screen brightness of the display panel is more than 0 nit (nit) and less than or equal to 50 nit in the low-brightness mode, and the white screen brightness of the display panel is more than 50 nit in the general mode. The backlight has a local dimming function. When in the low brightness mode, the local dimming function is in the first mode. When in the normal mode, the local dimming function is in the second mode.

Description

Electronic device

Technical Field

The present disclosure relates to an electronic device, and more particularly, to an electronic device capable of improving uniformity of a low-luminance or low-gray-scale image.

Background

In the conventional display device, at low brightness or low gray scale, the threshold voltage (Vth) and parasitic capacitance of the thin film transistor (thin film transistor, TFT) affect the driving current of the backlight source, so that the uniformity of the overall brightness of the backlight source is deteriorated, and the quality of the low gray scale or low brightness picture is poor. Therefore, there is a need for a new circuit architecture design that ameliorates the aforementioned problems.

Disclosure of Invention

The embodiment of the disclosure provides an electronic device, which comprises a display panel, a backlight source, an ambient light sensor and a controller. The backlight is arranged under the display panel and comprises a plurality of light emitting units. The ambient light sensor is used for sensing ambient light brightness. The controller is electrically connected with the display panel, the backlight source and the ambient light sensor, and is used for judging a general mode or a low-brightness mode according to the sensing result of the ambient light sensor, wherein the white screen brightness of the display panel is more than 0 nit (nit) and less than or equal to 50 nit in the low-brightness mode, and the white screen brightness of the display panel is more than 50 nit in the general mode. The backlight has a local dimming function. When the controller determines the low brightness mode, the local dimming function is in the first mode. When the controller judges the normal mode, the local dimming function is in the second mode.

The embodiment of the disclosure provides an electronic device, which comprises a display panel and a backlight source. The picture displayed by the display panel is formed by a plurality of sub-pictures corresponding to different colors. When the display panel displays the picture with the maximum brightness, the sub-picture has the maximum gray scale value at the same time. The backlight is arranged under the display panel and comprises a plurality of light emitting units. The backlight has a local dimming function. When the gray level of each of the sub-pictures in the first picture area of the picture displayed by the display panel is greater than zero gray level and less than or equal to 1/5 of the maximum gray level, and in the second picture area other than the first picture area, the gray level of at least one of the sub-pictures in the position corresponding to the second picture area is greater than 1/5 of the maximum gray level, the area dimming function controls the light emitting unit in the first backlight area corresponding to the first picture area in a first mode and controls the light emitting unit in the second backlight area corresponding to the second picture area in a second mode.

Drawings

Fig. 1 is a schematic diagram of an electronic device according to an embodiment of the disclosure.

Fig. 2 is a schematic diagram illustrating a correspondence relationship between a panel brightness of a display panel and a backlight brightness of a backlight according to an embodiment of the disclosure.

Fig. 3A is a schematic diagram of a display screen of a display panel and a backlight state of a backlight according to an embodiment of the disclosure.

Fig. 3B is a schematic diagram of a display screen of a display panel and a backlight state of a backlight according to an embodiment of the disclosure.

Fig. 3C is a schematic diagram of a display screen of a display panel and a backlight state of a backlight according to an embodiment of the disclosure.

Fig. 4 is a schematic diagram of a display screen of a display panel and a backlight state of a backlight according to an embodiment of the disclosure.

Fig. 5 is a schematic diagram of a display screen of a display panel and a backlight state of a backlight according to an embodiment of the disclosure.

Fig. 6A is a schematic diagram illustrating a correspondence relationship between a panel brightness of a display panel and a backlight brightness of a backlight according to an embodiment of the disclosure.

Fig. 6B is a schematic diagram illustrating a correspondence relationship between a panel brightness of a display panel and a backlight brightness of a backlight according to an embodiment of the disclosure.

Fig. 7 is a schematic diagram of an electronic device according to an embodiment of the disclosure.

Fig. 8 is a schematic diagram of a display screen of a display panel and a backlight state of a backlight according to an embodiment of the disclosure.

Fig. 9 is a schematic diagram illustrating a correspondence relationship between a gray level value of a frame of a display panel and a backlight brightness of a backlight according to an embodiment of the disclosure.

Fig. 10 is a schematic diagram of a display screen of a display panel and a backlight state of a backlight according to an embodiment of the disclosure.

Fig. 11A is a schematic diagram illustrating a correspondence relationship between a gray level value of a frame of a display panel and a backlight brightness of a backlight according to an embodiment of the disclosure.

Fig. 11B is a schematic diagram illustrating a correspondence relationship between a gray level value of a frame of a display panel and a backlight brightness of a backlight according to an embodiment of the disclosure.

Fig. 12 is a flowchart of a method of operating an electronic device according to an embodiment of the disclosure.

Fig. 13 is a flowchart of a method of operating an electronic device according to an embodiment of the disclosure.

[ symbolic description ]

100 700:

110 710 display panel

120 720 backlight source

121 721 light emitting unit

130 ambient light sensor

140 730 controller

A1 A2, B1, B2, C1, C2: region

411 412, 511, 512, 811, 812, 813, 1011, 1012, 1013: picture area

310 311, 312, 410, 510, 810, 1010: display screen of display panel

320 Backlight status of backlight 321, 322, 1020

421 First backlight area 521, 821, 1021

422 522, 822, 1022: second backlight area

823 1023 third backlight area

D1 Difference of D2, D3, D4

GL1: 1/5 of maximum gray level

L1 preset brightness value

L2 backlight luminance upper limit value

L3, L4, L6, L7, L8 luminance value

L5 fixed luminance value

RA1, RB1, RA2, RB2, RA3, RB3, RB4, RA5, RB5, RA6, RB6, straight lines

S1202 to S1212, S1302 to S1312

Detailed Description

The present disclosure will be described in detail with reference to the following examples, which are provided for clarity of understanding. In order to enable those skilled in the art to readily appreciate and make the drawings concise, the various drawings in the present disclosure may depict only a portion of the entire electronic device, and the specific elements in the drawings are not necessarily drawn to scale.

The present disclosure provides different examples to illustrate the technical features of different embodiments of the present disclosure. The arrangement, number and size of the elements in the embodiments are illustrative, and are not intended to limit the disclosure. In addition, if the embodiment and the reference numerals of the elements in the drawings are repeated, the relevance between the different embodiments is not meant to be implied for simplicity of description.

Furthermore, the use of ordinal numbers such as "first," "second," etc., in the description and the claims to modify a claim element does not by itself connote and indicate any preceding ordinal number for a requesting element, nor does it indicate the order in which a requesting element is ordered from another requesting element, or the order in which it is manufactured, and the use of such ordinal numbers serves to clearly distinguish one requesting element having a certain name from another requesting element having a same name.

In the present disclosure, features of the embodiments may be mixed and matched at will without departing from the spirit of the invention or conflicting.

In some embodiments of the present disclosure, the terms "coupled" and "electrically connected" may include any means of direct or indirect electrical connection, unless specifically defined otherwise.

In this context, the terms "about", "approximately", "about" and "approximately" generally refer to a range within 20%, or within 10%, or within 5%, or within 3%, or within 2%, or within 1%, or within 0.5% of a given value. The amounts given herein are about amounts, i.e., where "about" is not specifically recited, the meaning of "about" may still be implied.

In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to.

Furthermore, the term "coupled" as used herein includes any direct or indirect means of coupling. Thus, when an element or film is referred to as being "connected" to another element or film, it can be directly connected to the other element or film or intervening elements or films may be present therebetween. When an element is referred to as being "directly connected" to another element or film, there are no intervening elements or films present therebetween. The terms "coupled," "electrically connected," and "connected," unless specifically defined otherwise, may encompass any direct or indirect means of electrical connection.

In an embodiment, the electronic device may include a display device, a backlight device, an antenna device, a sensing device, a stitching device or a therapeutic diagnostic device, but is not limited thereto. The electronic device may be a bendable or flexible electronic device. The display device may be a non-self-luminous type display device or a self-luminous type display device. The antenna device may be a liquid crystal type antenna device or a non-liquid crystal type antenna device, and the sensing device may be a sensing device for sensing capacitance, light, heat energy or ultrasonic waves, but is not limited thereto. The electronic devices may include passive devices and active devices such as capacitors, resistors, inductors, diodes, transistors, etc. The diode may include a light emitting diode (light emitting diode, LED) or a Photodiode (PD). The light emitting diode may include, for example, an organic light emitting diode (organic light emitting diode, OLED), a sub-millimeter light emitting diode (mini LED), a micro LED, or a quantum dot LED (but is not limited thereto. The splicing device can be, for example, a display splicing device or an antenna splicing device, but is not limited to this. It should be noted that the electronic device may be any of the above arrangements, but is not limited thereto. The display device is used as an electronic device to illustrate the disclosure, but the disclosure is not limited thereto.

Fig. 1 is a schematic diagram of an electronic device according to an embodiment of the disclosure. Referring to fig. 1, the electronic device 100 may at least include a display panel 110 and a backlight 120. In some embodiments, the electronic device 100 may further include an ambient light sensor 130. The ambient light sensor 130 may output a signal to control the panel brightness of the display panel 110. Further, the electronic device 100 may further include a controller 140. The controller 140 may be electrically connected to the display panel 110, the backlight 120, and the ambient light sensor 130.

In the present embodiment, the display panel 110 may be a liquid crystal display panel (liquid crystal display panel, LCD panel), but the present disclosure is not limited thereto. The display panel 110 may include a plurality of pixel units, and each pixel unit may include at least a thin film transistor (thin film transistor, TFT), but the present disclosure is not limited thereto.

The backlight 120 may be disposed under the display panel 110 and include a plurality of light emitting units 121, wherein the light emitting units 121 may be light emitting diodes, but is not limited thereto. Further, the backlight 120 may be disposed under the display panel 110 in a top view direction, and the light emitting units 121 may be arranged in a matrix, but the disclosure is not limited thereto. In addition, the backlight 120 may have a local dimming function (local dimming function). In the present embodiment, the area dimming function may cause the light emitting units 121 in the first backlight of the backlight 120 to emit light in an area, and the light emitting units 121 in the second backlight area other than the first backlight area of the backlight 120 to emit no light, wherein the first backlight area is different from the second backlight area, but the disclosure is not limited thereto. For example, in some embodiments, the local dimming function may adjust a first backlight region of the backlight 120 to a first brightness and adjust a second backlight region of the backlight 120 other than the first backlight region to a second brightness, where the first brightness is different from the second brightness. It should be noted that, for simplicity of description in this disclosure, the term "backlight area" will be used to refer to the light emitting unit 121 located in the backlight area. For example, "the first backlight region is adjusted to the first luminance" means that the light emission luminance of the light emitting unit 121 located in the first backlight region of the backlight 120 is adjusted to the first luminance. The remaining terms can be analogized.

As shown in fig. 1, the backlight 120 and the display panel 110 are controlled by the controller 140, and the controller 140 can adjust the brightness of the backlight 120 and the brightness of the display panel 110 according to the signals output by the ambient light sensor 130 after sensing. In some embodiments, the controller 140 may determine the low-light mode when the ambient light is weak (e.g., indoors or at night). More specifically, the white brightness of the display panel 110 (i.e. when the panel is at maximum brightness) may be changed by the sensing result of the ambient light sensor 130, when the ambient light is weak and enters the low brightness mode, the local dimming function of the backlight 120 may be in the first mode when the white brightness is reduced to a range greater than 0 nit and less than or equal to 50 nit (such as the area A1 shown in fig. 2) due to the low brightness mode, wherein the relationship between the white brightness and the upper limit of the backlight brightness is represented by the straight line RA1 in fig. 2. In some embodiments, in the first mode, the local dimming function of the backlight 120 may be turned off, so that the entire backlight 120 may emit light with a preset brightness value L1, as shown in fig. 3A, but the disclosure is not limited thereto. In fig. 3A, reference numeral "310" is a display screen of the display panel 110, and reference numeral "320" is a light emitting state of the backlight 120. As can be seen from fig. 3A, all the light emitting units 121 of the backlight 120 can emit light at a preset luminance L1 value, so that the backlight 120 generates a backlight of the preset luminance L1. That is, the area A1 shown in fig. 2 corresponds to the low luminance mode, and the luminance value L1 of the backlight luminance of the backlight 120 is fixed. Note that, since the display panel 110 in the present disclosure does not emit light, the pixel unit controls the transmittance of light to form a picture, and thus the display picture 310 also corresponds to the transmittance distribution of light of the display panel 110. The "white brightness" refers to the brightness of the light emitted from the display panel 110 after the light is emitted from the backlight 120 and passes through the display panel 110 when the light transmittance of the display panel 110 is maximum.

Additionally, in some embodiments, the controller 140 may determine the normal mode when the ambient light is strong (e.g., generally outdoors). At this time, the white screen brightness of the display panel 110 may be greater than 50 nits, and at this time, the local dimming function of the backlight 120 may be in the second mode, such as the area B1 shown in fig. 2. In the present embodiment, in the second mode, the maximum luminance value of the backlight luminance of the backlight 120 may increase with the increase of the white screen luminance of the display panel 110, and the relationship between the white screen luminance and the upper limit of the backlight luminance is represented by a line RB1 in fig. 2. However, the brightness distribution of the backlight 120 may correspond to the brightness distribution of the screen displayed on the display panel 120 by the local dimming function, as shown in fig. 3B, but the disclosure is not limited thereto. More specifically, in fig. 3B, reference numeral "311" is a display screen of the display panel 110 (corresponding to the light transmittance distribution of the display panel 110 itself), and reference numeral "321" is a backlight state of the backlight 120. As can be seen from fig. 3B, the luminance distribution of the light emitted by all the light emitting units 121 of the backlight 120 may correspond to the luminance distribution of the picture of the display panel 110. It should be noted that, since the relationship between the white screen brightness (i.e. the maximum brightness of the panel display) and the upper limit of the backlight brightness is presented in the area B1 of fig. 2, the local dimming function is turned on in the second mode. Thus, when a dark block appears in the frame (e.g., the black portion of frame 311), the local dimming function will dim or even not illuminate the portion of backlight 120 corresponding to the dark block. In addition, although the relationship between the white screen luminance and the backlight luminance upper limit is represented in a linear scale in the present disclosure, in some embodiments, the relationship between the white screen luminance and the backlight luminance upper limit may be represented in a nonlinear non-linear scale.

In addition, in some embodiments, the controller 140 determines the black mode when the white brightness of the display panel 110 is equal to 0 nit. The local dimming function of the backlight 120 may be in a third mode at this time, such as the region C1 shown in fig. 2. In the present embodiment, in the third mode, the backlight of the backlight 120 may not emit light, as shown in fig. 3C. Reference numeral "322" is a backlight state of the backlight 120. As can be seen from fig. 3C, all the light emitting units 121 of the backlight 120 do not emit light. That is, in the region C1 shown in fig. 2, the display panel 110 may be a black screen, and the backlight 120 does not emit light. It should be noted that, in the previous paragraph, the "white brightness" refers to the brightness of the light emitted from the display panel 110 after the light is emitted from the backlight 120 and passes through the display panel 110 when the light transmittance of the display panel 110 is maximum. Therefore, even though the display panel itself may still have a light transmittance distribution at different locations (e.g., as shown by the screen 312 in fig. 3C), the display panel 110 still presents a black screen when the backlight is not emitting light.

In the above embodiment, in the first mode, the local dimming function is turned off and the backlight 120 emits light at the preset luminance value L1, but the disclosure is not limited thereto. In the embodiment shown in fig. 4, in the first mode corresponding to the area A1 of fig. 2, the screen 410 displayed on the display panel 110 may include a specific screen area (e.g. the screen area 411) and other screen areas (e.g. the screen area 412) outside the specific screen area, and the area dimming function of the backlight 120 may make the first backlight area 421 corresponding to the screen area 411 in the backlight 120 emit light with a luminance value L1, and the luminance value L1 is fixed.

Further, in the first mode corresponding to the area A1 of fig. 2, the local dimming function of the backlight 120 may further cause the second backlight area 422 corresponding to the screen area 412 in the backlight 120 to not emit light. That is, in the present embodiment, in the first mode corresponding to the area A1 of fig. 2, the first backlight area 421 of the backlight 120 can emit light with a preset brightness (e.g. brightness L1) and the second backlight area 422 of the backlight 120 does not emit light by the area dimming function of the backlight 120.

As shown in fig. 5, in other embodiments, the screen 510 displayed by the display panel 110 may have a specific screen region (e.g., screen region 511) and other screen regions outside the specific screen region (e.g., screen region 512). In the first mode, the local dimming function of the backlight 120 may cause the first backlight area 521 corresponding to the picture area 511 in the backlight 120 to emit light according to the first backlight brightness-panel brightness ratio relationship, and the second backlight area 522 corresponding to the picture area 512 to emit no light.

In the present embodiment, the first backlight luminance-panel luminance ratio relationship described above may be represented by a straight line RA2 or RA3 within the area A1 as in fig. 6A or 6B. More specifically, in the embodiment of fig. 5, when the backlight 120 emits light in the first mode, the upper limit value of the brightness of the first backlight area 521 of the backlight 120 may increase as the white screen brightness of the display panel 110 increases. In addition, when there are still blocks with different brightness in the frame region 511 of the frame 510, the local dimming function of the backlight 120 can also enable the light emitting units 121 in the first backlight region 521 to adjust the light emitting brightness along with the corresponding blocks with different brightness. For example, in fig. 5, when the lower half of the screen region 511 in the screen 510 is brighter, the lower half of the first backlight region 521 of the backlight 120 is also brighter. That is, in the embodiment corresponding to fig. 5, 6A or 6B, when the backlight 120 is operated in the first mode, the local dimming function of the backlight 120 may not only make the portion of the backlight 120 not corresponding to the specific frame area in the frame not emit light, but also make the portion corresponding to the specific frame area further individually control the light emitting units 121 according to the brightness distribution in the specific frame area.

In the embodiment corresponding to fig. 5, 6A or 6B, when the backlight 120 is operated in the second mode, the local dimming function of the backlight 120 may enable the backlight 120 to emit light according to the second backlight luminance-panel luminance ratio relationship.

Similar to the region B1 of fig. 2, in the region B1 shown in fig. 6A (or 6B), the relationship of the white screen luminance (i.e., the panel maximum luminance) and the backlight luminance upper limit is represented by a straight line RB2 (or a straight line RB 3), but the present disclosure is not limited thereto. Also, since the backlight 120 turns on the local dimming function in the second mode. Therefore, when a dark area appears in the screen, the local dimming function will darken or even not illuminate the portion of the backlight 120 corresponding to the dark area.

In addition, fig. 6A and 6B are different in that the slope of the first backlight luminance-panel luminance ratio relationship of the region A1 may be different, and the backlight luminance upper limit value corresponding to the left start point of the straight line RA2 and the left start point of the straight line RB2 in fig. 6A are both L2, but the backlight luminance upper limit value corresponding to the left start point (luminance value L3) of the straight line RA3 and the left start point (luminance value L4) of the straight line RB3 in fig. 6B are different. It should be noted that in fig. 6A and 6B, there is a difference D1 and D2 between the maximum backlight luminance (i.e. the luminance value corresponding to the right end point of the straight line RA2 and the straight line RA 3) of the first backlight luminance-panel luminance ratio in the area A1 and the minimum backlight luminance (i.e. the luminance value corresponding to the left end point of the straight line RB2 or the straight line RB 3) of the second backlight luminance-panel luminance ratio in the area B1, respectively, but the disclosure is not limited thereto. For example, in some embodiments, at 50 nit of the panel luminance in fig. 6A, the difference D1 may be zero, that is, the maximum backlight luminance of the first backlight luminance-panel luminance ratio of the area A1 may be the same as the minimum backlight luminance of the second backlight luminance-panel luminance ratio of the frame area B1. In some other embodiments, the maximum backlight luminance of the first backlight luminance-panel luminance ratio relationship corresponding to the region A1 may be still smaller than the minimum backlight luminance of the second backlight luminance-panel luminance ratio relationship corresponding to the region B1. In addition, the regions B1 and C1 of fig. 6A or 6B and the regions B1 and C1 of fig. 2 are the same or similar, and reference may be made to the description of the embodiment of fig. 2, so that the description thereof is omitted herein. Furthermore, the regions B1 and C1 of fig. 6A or 6B may correspond to the embodiments shown in fig. 3B and 3C.

Fig. 7 is a schematic diagram of an electronic device according to an embodiment of the disclosure. Referring to fig. 7, the electronic device 700 may at least include a display panel 710 and a backlight 720.

In some embodiments, the electronic device 700 may further include a controller 730. The controller 730 may be electrically connected to the display panel 710 and the backlight 720. The controller 730 may receive a picture signal. Then, the controller 730 can determine the gray-scale values of the plurality of frame regions in the frame 810 displayed on the display panel 710 according to the frame signals. Then, the controller 730 can determine the operation mode corresponding to each of the plurality of frame regions according to the gray-scale values in the plurality of frame regions. Then, the controller 730 may control the backlight brightness of the backlight 720 according to the operation modes corresponding to the image areas. It should be noted that, the pixel units in the display panel 710 adjust the light transmittance of the pixel units according to the gray-scale values corresponding to the pixel units, so that the light is emitted from the backlight 720 and penetrates the display panel 710 to display a picture.

In the present embodiment, the display panel 710 may be a liquid crystal display panel, but the present disclosure is not limited thereto. In addition, the screen displayed by the display panel 710 may be formed of a plurality of sub-screens corresponding to different colors. In the present embodiment, the sprites are red (R), green (G), and blue (B) pictures, for example, but the disclosure is not limited thereto. That is, the screen displayed by the display panel 710 may be formed of sub-screens of at least three colors (e.g., red, green, and blue). In addition, when the screen displayed on the display panel 710 has the maximum brightness, the sub-screen may have the maximum gray scale value at the same time. In the present embodiment, the maximum gray level value is, for example, 255, 511 or 1023 or other suitable gray level values, but the disclosure is not limited thereto.

The backlight 720 may be disposed under the display panel 710 and include a plurality of light emitting units 721. Further, the backlight 720 may be disposed under the display panel 710 in a top view direction, and the light emitting units 721 may be arranged in a matrix, but the disclosure is not limited thereto. In addition, the backlight 720 may have a local dimming function. In the present embodiment, the local dimming function may make a first backlight area of the backlight 720 emit light with a first brightness, and make a second backlight area of the backlight 720 other than the first backlight area emit no light or emit light with a second brightness, wherein the first backlight area is different from the second backlight area, and the first brightness is also different from the second brightness, but the disclosure is not limited thereto.

Please refer to fig. 8 and 9. In some embodiments, when the display panel 710 displays a frame 810 having a frame area 811, wherein each of the sub-frames (i.e., each of the sub-frames of colors) has a gray level value greater than zero and less than or equal to 1/5 of the maximum gray level value (e.g., reference "GL1" in fig. 9) at a position corresponding to the frame area 811, the controller 730 determines that the frame area 811 is in the low gray level mode. The local dimming function of the backlight 720 may control the light emitting unit 721 of the first backlight area 821 corresponding to the screen area 811 in the first mode.

In the present embodiment, in the first mode, the first backlight area 821 corresponding to the screen area 811 emits light at a preset fixed luminance value L5, as shown in the area A2 of fig. 8 and 9.

In addition, when there is another frame area (e.g., frame area 812 in fig. 8) in the frame 810, the gray-scale value of any one color sub-frame at the position corresponding to the frame area 812 is greater than 1/5 of the maximum gray-scale value, and the controller 730 determines that the frame area 812 is in the normal mode. The local dimming function of the backlight 720 can control the light emitting units 721 of the second backlight area 822 corresponding to the frame area 812 in the second mode. In the second mode, the light emitting luminance value of the light emitting unit 721 may increase as the gray scale value increases, and the relationship between the backlight luminance and the gray scale value thereof may be as shown by a straight line RB4 in the region B2 of fig. 9. That is, in the region B2 shown in fig. 9, the frame 810 may have a frame region 812, at least one of the sub-frames has a gray level greater than 1/5 of the maximum gray level at the position corresponding to the frame region 812, and the brightness value of the backlight 720 in the second backlight region 822 at the position corresponding to the frame region 812 is adjustable. It should be noted that, although the relationship between the backlight brightness and the gray scale value is represented by a linear scale in the present disclosure, in some embodiments, the relationship between the backlight brightness and the gray scale value may be represented by a nonlinear non-linear scale.

In addition, the frame 810 may also have a "zero gray scale value region" (e.g., frame region 813). The gray scale value of each color sub-frame at the position corresponding to the "zero gray scale value region" is 0, i.e. the frame region 813 of the display panel 710 presents a black block. At this time, the controller 730 determines that the screen area 813 is in the zero gray mode. The area dimming function of the backlight 720 may control the light emitting unit 721 of the third backlight area 823 corresponding to the screen area 813 in the third mode. In the present embodiment, in the third mode, the third backlight area 823 corresponding to the screen area 813 in the backlight 720 does not emit light. That is, in the region C2 shown in fig. 9, the screen region 813 of the display panel 710 appears black, and the luminance value of the third backlight region 823 corresponding to the screen region 813 in the backlight 720 is zero.

Please refer to fig. 10, fig. 11A and fig. 11B. In some embodiments, when the gray-scale value of each color of the sub-picture in the picture area 1011 of the picture 1010 displayed on the display panel 710 at the position corresponding to the picture area 1011 is greater than zero gray-scale and less than or equal to 1/5 of the maximum gray-scale value (e.g., the reference symbol "GL1" shown in fig. 11A or 11B), the controller 730 determines that the picture area 1011 is in the low gray-scale mode. At this time, the local dimming function of the backlight 720 may control the light emitting unit 721 of the first backlight area 1021 corresponding to the frame area 1011 in the first mode, and when the frame 1010 has a frame area 1012 such that the gray scale value of at least one of the sub-frames at the position corresponding to the frame area 1012 is greater than 1/5 of the maximum gray scale value, the controller 730 determines that the frame area 1012 is in the normal mode. The local dimming function controls the light emitting unit 721 of the backlight 720 corresponding to the second backlight area 1022 of the screen area 1012 in the second mode, as shown in fig. 10 and 11A or fig. 10 and 11B.

In the present embodiment, in the first mode, the light emitting unit 721 of the first region 1021 may emit light according to a first backlight luminance-gray scale value ratio relationship, in the second mode, the light emitting unit 721 of the second region 1022 may emit light according to a second backlight luminance-gray scale value ratio relationship, and the first backlight luminance-gray scale value ratio relationship may be different from the second backlight luminance-gray scale value ratio relationship, but the disclosure is not limited thereto. The first backlight luminance-gray scale value ratio may be represented as a straight line RA5 or RA6 in the region A2 shown in fig. 11A or 11B, and the second backlight luminance-gray scale value ratio may be represented as a straight line RB5 or RB6 in the region B2 shown in fig. 11A or 11B. The above-mentioned expression that the first backlight luminance-gray scale value proportional relationship is different from the second backlight luminance-gray scale value proportional relationship may be understood as that the straight line RA5 (or the straight line RA 6) and the straight line RB5 (or the straight line RB 6) have different slopes, but the present disclosure is not limited thereto. In addition, fig. 11A and 11B are different in that the slope of the first backlight luminance-panel luminance ratio relationship of the region A2 may be different, and the luminance values corresponding to the left start point of the straight line RA5 and the left start point of the straight line RB5 in fig. 11A are the same as L6, but the luminance values corresponding to the left start point of the straight line RA6 (luminance value L7) and the left start point of the straight line RB6 (luminance value L8) in fig. 11B are different.

In some embodiments, in fig. 11A and 11B, there is a gap D3 and D4 between the maximum backlight luminance (i.e. the right end point of the straight line RA5 or the straight line RA 6) of the first backlight luminance-panel luminance ratio in the area A2 and the minimum backlight luminance (i.e. the left end point of the straight line RB5 or the straight line RB 6) of the second backlight luminance-gray scale value ratio in the area B2, but the disclosure is not limited thereto. That is, the maximum luminance emitted from the light emitting unit 721 of the first backlight area 1021 in the backlight 720 according to the first backlight luminance-gray scale value ratio relationship may be greater than the minimum luminance emitted from the light emitting unit 721 of the second backlight area 1022 according to the second backlight luminance-gray scale value ratio relationship, as shown in fig. 11A or 11B, but the disclosure is not limited thereto. In some embodiments, the maximum backlight luminance of the first backlight luminance-gray scale value ratio relationship corresponding to the region A2 may be equal to the minimum backlight luminance of the second backlight luminance-gray scale value ratio relationship corresponding to the region B2. In some other embodiments, the maximum backlight brightness of the first backlight brightness-gray scale value proportional relationship corresponding to the region A2 may be smaller than the minimum backlight brightness of the second backlight brightness-gray scale value proportional relationship corresponding to the region B2. In addition, the regions B2 and C2 of fig. 11A or 11B and the regions B2 and C2 of fig. 9 are the same or similar, and reference may be made to the description of the embodiment of fig. 9, so that the description thereof is omitted here.

Fig. 12 is a flowchart of a method of operating an electronic device according to an embodiment of the disclosure. Fig. 12 may correspond to the embodiments of fig. 1-6B. In step S1202, the light intensity of the ambient light is sensed by the ambient light sensor and a signal is output. In step S1204, the controller receives the signal output by the ambient light sensor to adjust the white screen brightness of the display panel. In step S1206, a corresponding operation mode is determined according to the white screen brightness of the display panel. When the controller determines that the operation mode is the low brightness mode, step S1208 is performed, and the local dimming function of the backlight is in the first mode. In some embodiments, in the first mode corresponding to the area A1 of fig. 2 and the first mode of fig. 3A, the local dimming function is turned off, and the backlight emits light with a preset brightness value (e.g., the brightness value L1 in fig. 2).

In some embodiments, in the first mode corresponding to the area A1 of fig. 2 and the first mode of fig. 4, the display panel displays a frame including a specific frame area, the area dimming function makes a first backlight area of the backlight source corresponding to the specific frame area emit light with a preset brightness value (e.g. the brightness value L1 of fig. 2), and a second backlight area of the backlight source other than the specific frame area emit no light. In some embodiments, in the first mode corresponding to the area A1 of fig. 5 and 6A or the area A1 of fig. 5 and 6B, the display panel displays a picture having a specific picture area, and the area dimming function makes the first backlight area corresponding to the specific picture area in the backlight emit light according to the first backlight brightness-panel brightness ratio relationship and the second backlight area corresponding to the other picture areas except the specific picture area emit no light.

When the controller determines that the normal mode is the normal mode, the step S1210 is performed, and the local dimming function of the backlight is in the second mode. In some embodiments, in the second mode, the backlight turns on the local dimming function. Therefore, when a dark block appears in the picture, the local dimming function can darken or even not illuminate the portion of the backlight source corresponding to the dark block.

When the controller determines that the black screen mode is in the black screen mode, the step S1212 is performed, and the local dimming function of the backlight is in the third mode. In some embodiments, in the third mode corresponding to the areas C1 and C1 of fig. 2 and 3C, the areas C1 of fig. 6A and the areas C1 of fig. 3C or 6B and the areas C3C, the backlight does not emit light and the display panel displays a black image.

Fig. 13 is a flowchart of a method of operating an electronic device according to an embodiment of the disclosure. Fig. 13 may correspond to the embodiment of fig. 7-11B. In step S1302, a frame signal is received by the controller. In step S1304, the controller determines gray-scale values of a plurality of screen areas of the screen displayed on the display panel according to the screen signal. In step S1306, the controller determines the operation modes corresponding to the image areas according to the gray scale values in the image areas. When the controller determines that a frame area of the display panel is in the low gray level mode, step S1308 is performed, where the area dimming function of the backlight source controls the light emitting units of the backlight area of the backlight source corresponding to the frame area in the first mode. In some embodiments, in the picture areas 811 and 821 corresponding to fig. 8 and the area A2 of fig. 9, the light emitting units in the backlight area corresponding to this picture area emit light with a preset luminance value (e.g., L5 of fig. 9). In some embodiments, in the first mode corresponding to the picture area 1011, 1021 of fig. 10 and the area A2 of fig. 11A or the picture area 1011, 1021 of fig. 10 and the area A2 of fig. 11B, the backlight area corresponding to the picture area emits light according to the first backlight luminance-gray scale value ratio relationship.

When the controller determines that the frame area of the display panel is in the normal mode, the step S1310 is performed, and the area dimming function of the backlight source controls the light emitting units in the backlight area corresponding to the frame area in the second mode. In some embodiments, in the second mode corresponding to the regions 812, 822 of fig. 8 and the region B2 of fig. 9, the regions 1012, 1022 of fig. 10 and the region B2 of fig. 11A or the regions 1012, 1022 of fig. 10 and the region B2 of fig. 11B, the light emitting units of the second backlight region emit light according to the second backlight luminance-gray scale value ratio. In addition, the first backlight luminance-gray scale value ratio relationship may be different from the second backlight luminance-gray scale value ratio relationship.

When the controller determines that the frame area of the display panel is in the zero gray mode, the step S1312 is proceeded, and the area dimming function of the backlight source controls the light emitting units of the backlight area corresponding to the frame area in the third mode. In some embodiments, in the third mode corresponding to the screen regions 813, 823 of fig. 8 and the region C2 of fig. 9, the screen regions 1013, 1023 of fig. 10 and the region C2 of fig. 11A, or the screen regions 1013, 1023 of fig. 10 and the region C3 of fig. 11B, the backlight does not emit light, and the screen regions display black.

In summary, in the electronic device of the embodiment of the disclosure, when the white screen brightness of the display panel is greater than 0 nit and less than or equal to 50 nit, the local dimming function of the backlight is in the first mode, and when the white screen brightness of the display panel is greater than 50 nit, the local dimming function is in the second mode. In addition, in some embodiments, when the frame displayed on the display panel includes a first frame area and a second frame area, and the gray-scale value of each of the plurality of sub-frames for forming the frame is greater than zero and less than or equal to 1/5 of the maximum gray-scale value at the position corresponding to the first frame area, the area dimming function of the backlight source controls the light emitting unit in the backlight area corresponding to the first frame area in the first mode, and when the gray-scale value of at least one of the plurality of sub-frames at the position corresponding to the second frame area is greater than 1/5 of the maximum gray-scale value, the area dimming function controls the light emitting unit in the backlight area corresponding to the second frame area in the second mode. Therefore, the situation that the overall brightness uniformity of the backlight source is poor, and the picture quality of low gray scale or low brightness is poor is avoided, or the picture uniformity of low brightness or low gray scale is improved.

Although the present disclosure has been described with reference to certain embodiments, those skilled in the art will appreciate that various modifications, substitutions, rearrangements, mixtures, and substitutions can be made without departing from the spirit and scope of the disclosure.

Claims (10)

1. An electronic device, comprising:

a display panel;

a backlight source arranged below the display panel and comprising a plurality of light emitting units;

an ambient light sensor for sensing ambient light level;

the controller is electrically connected with the display panel, the backlight source and the ambient light sensor and is used for judging a general mode or a low-brightness mode according to the sensing result of the ambient light sensor, wherein the white picture brightness of the display panel is more than 0 nit and less than or equal to 50 nit in the low-brightness mode, and the white picture brightness of the display panel is more than 50 nit in the general mode;

the backlight source has a local dimming function, and when the controller judges that the low-brightness mode is adopted, the local dimming function is in a first mode; and when the controller judges that the general mode is adopted, the local dimming function is in a second mode.

2. The electronic device of claim 1, wherein in the first mode, the local dimming is turned off and the backlight emits light at a predetermined brightness value.

3. The electronic device of claim 1, wherein in the first mode, the frame displayed on the display panel includes a specific frame area, and the local dimming function causes the light emitting unit in the first backlight area corresponding to the specific frame area to emit light with a preset brightness value.

4. The electronic device of claim 3, wherein in the first mode, the light emitting units in the second backlight area of the backlight corresponding to the outside of the specific frame area do not emit light.

5. The electronic device of claim 1, wherein in the first mode, the frame displayed on the display panel has a specific frame area, and the area dimming function causes the light emitting units in a first backlight area corresponding to the specific frame area in the backlight to emit light according to a first backlight brightness-panel brightness ratio relationship and the light emitting units in a second backlight area other than the specific frame area to emit no light.

6. The electronic device of claim 1, wherein in the second mode, the local dimming function is turned on and the light emitting unit of the backlight emits light according to a second backlight luminance-panel luminance ratio.

7. An electronic device, comprising:

a display panel, wherein a picture displayed by the display panel is formed by a plurality of sub-pictures corresponding to different colors, and when the picture displayed by the display panel has maximum brightness, the sub-pictures simultaneously have maximum gray scale values; and

a backlight source arranged below the display panel and comprising a plurality of light emitting units;

the backlight source has a region dimming function, when the gray level of each sub-picture in a first picture region of the picture displayed by the display panel is greater than zero gray level and less than or equal to 1/5 of the maximum gray level in a position corresponding to the first picture region, and the gray level of at least one sub-picture in a second picture region outside the first picture region is greater than 1/5 of the maximum gray level in a position corresponding to the second picture region, the region dimming function controls the light emitting units in the first backlight region corresponding to the first picture region in a first mode and controls the light emitting units in the second backlight region corresponding to the second picture region in a second mode.

8. The electronic device of claim 7, wherein in the first mode, the light emitting unit in the first backlight area corresponding to the first picture area emits light with a preset brightness value.

9. The electronic device of claim 7, wherein in the first mode, the light emitting units in the first backlight region emit light according to a first backlight luminance-gray scale value ratio, and in the second mode, the light emitting units in the second backlight region emit light according to a second backlight luminance-gray scale value ratio, and the first backlight luminance-gray scale value ratio is different from the second backlight luminance-gray scale value ratio.

10. The electronic device of claim 9, wherein the maximum luminance of the light emitting units in the first backlight area according to the first backlight luminance-gray scale value ratio is greater than the minimum luminance of the light emitting units in the second backlight area according to the second backlight luminance-gray scale value ratio.