Patent Description:
In related arts, an optical sensor is generally assembled on a terminal device having a screen and configured to detect the intensity of ambient light, so as to adjust the intensity of backlight according to the intensity of the ambient light. The display effect of the screen can therefore be adjusted to be within a comfortable brightness range which is acceptable to the human eyes. For example, in a mobile phone using a liquid-crystal display (LCD), the optical sensor is disposed at the position of a frame and under a glass cover, and is arranged in the same horizontal plane with the backlight board. For example, in a mobile phone using an organic light-emitting diode (OLED) display, the optical sensor is disposed at the position of a frame or under the OLED display. However, in the above solutions, it is necessary to add an independent element (optical sensor) to detect the optical parameters of the ambient light, which not only increases the costs but also reduces the screen-to-body ratio of the terminal device due to the large additional space occupied by the independent element.

<CIT> discloses an OLED display including a first substrate on which a plurality of OLEDs are formed, a second substrate attached to the first substrate, a plurality of photo sensors formed on the second substrate, and a shield layer covering the photo sensor.

Further display devices are disclosed in: <CIT>, <CIT>, <CIT>and <CIT>.

In order to overcome the problems in the related art, the embodiments of the present disclosure are directed to provide a display panel and a terminal device for reducing the cost of the terminal device in detecting the optical parameters of ambient light.

A display panel according to the present invention is defined by independent claim <NUM>. Further aspects of the present invention are defined by the dependent claims.

According to a particular embodiment, there is no overlap area between a projection of the photoelectric sensing layer (<NUM>) on the substrate (<NUM>) and a projection of the pixel unit (CF) on the substrate (<NUM>).

According to a particular embodiment, the display panel (<NUM>) further including:
a visible light selective transmission layer (<NUM>) disposed on the photoelectric sensing layer (<NUM>) and configured to allow visible light in a specified wavelength range in an ambient light to pass through and transmit the visible light to the photoelectric sensing layer (<NUM>).

According to a particular embodiment, the pixel unit includes subpixel units of N colors;.

According to a particular embodiment, the projection of the photoelectric sensing layer (<NUM>) on the substrate (<NUM>) falls within a projection of the visible light selective transmission layer (<NUM>) on the substrate (<NUM>).

According to a particular embodiment, the pixel layer (<NUM>) includes:.

According to a particular embodiment, the pixel layer (<NUM>) includes an organic light-emitting layer; the display panel (<NUM>) further comprises:.

According to a particular embodiment, a projection area of the photoelectric sensing layer (<NUM>) on the substrate (<NUM>) is greater than a specified area; and/or
a projection of the photoelectric sensing layer (<NUM>) on the substrate (<NUM>) is uniformly distributed.

According to a particular embodiment, the visible light selective transmission layer (<NUM>) includes an optical grating.

According to an exemplary embodiment of the present disclosure, there is provided a terminal device, including:.

According to a particular embodiment, the terminal device further including:.

The technical solutions provided by the embodiments of the present disclosure may provide a display panel and a terminal device, which can help reduce the cost of the terminal device in detecting the optical parameters of the ambient light.

The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments consistent with the disclosure and, together with the description, serve to explain the principles of the present disclosure.

<FIG> and <FIG> are structural schematic views illustrating a terminal device <NUM> according to related art. The terminal device <NUM> can be a mobile phone, a tablet PC, and the like. The terminal device <NUM> can include a display panel <NUM>, a glass cover <NUM>, an optical sensor <NUM> and a housing <NUM>. The display panel <NUM> is located below the glass cover <NUM>. The optical sensor <NUM> may be located below the display panel <NUM>. The display panel <NUM> is located in the housing <NUM>. Light emitted by the display panel <NUM> can pass through the glass cover <NUM>. The display panel <NUM> may be viewed through the transparent glass cover <NUM>. The display panel <NUM>, for instance, may be an OLED display panel or an LCD display panel, but not limited thereto. The optical sensor <NUM> is disposed below the display panel <NUM>, which is helpful to enhance the screen-to-body ratio. The optical sensor <NUM> may be configured to detect the optical parameters of ambient light in an environment provided with the terminal device <NUM>. However, the cost is high to add an independent photosensitive element to detect the optical parameters of the ambient light.

Various embodiments of the present disclosure provide a display panel and a terminal device for solving the above technical problem and which can reduce the cost of the terminal device in detecting the optical parameters of the ambient light.

Some embodiments of the present disclosure provide a display panel, which may be applied to the terminal device. As shown in <FIG> and <FIG>, the display panel <NUM> includes: a substrate <NUM>, a pixel layer <NUM> and a photoelectric sensing layer <NUM>.

In some embodiments of the present disclosure, the pixel layer <NUM> is located on the substrate <NUM> and includes pixel units CF arranged in an array. The photoelectric sensing layer <NUM> is located on one side of the substrate <NUM> away from the pixel layer <NUM> or located on one side of the substrate <NUM> close to the pixel layer <NUM>. The photoelectric sensing layer <NUM> is configured to convert a received optical signal into an electrical signal.

In some embodiments of the present disclosure, as the photoelectric sensing layer is located away from the pixel layer or located close to the pixel layer in the display panel, the photoelectric sensing layer may be configured to detect the optical parameters of the ambient light. As the cost of integrating the photoelectric sensing layer in the display panel is lower than that of additionally arranging an independent optical sensor on the outside of the display panel, the cost of the terminal device in detecting the optical parameters of the ambient light can be reduced. Moreover, the screen-to-body ratio of the terminal device can also be enhanced.

In some embodiments, there is no overlap area between a projection of the photoelectric sensing layer <NUM> on the substrate <NUM> and a projection of the pixel unit CF on the substrate <NUM>. In other words, the elements of the photoelectric sensing layer <NUM> and the pixel units CF of the pixel layer <NUM> do not overlap in a viewing direction. The viewing direction is the direction from which a user will look on the display during the use of the device. Thus, the detection of the ambient light will not affect the display effect and the light emitted by the display panel will not affect the detection of the ambient light.

In some embodiments of the present disclosure, the integration of the photoelectric sensing layer in the display panel can also avoid the arrangement of the independent optical sensor in the terminal device from affecting the functions of other elements and can improve the overall performances of the terminal device.

In some embodiment, the display panel may be an LCD display panel. In another optional embodiment, the display panel may be an OLED display panel. As the LCD display panel and the OLED display panel have different structures, description will be given below to the LCD display panel and the OLED display panel respectively.

Some embodiments of the present disclosure further provide a display panel. In some embodiments, referring to <FIG> and <FIG>, the display panel <NUM> may be an LCD display panel. In some embodiments, referring to <FIG>, the photoelectric sensing layer <NUM> is disposed at a side of the substrate <NUM> proximal (close) to the pixel layer <NUM>.

In some embodiments, the pixel unit CF includes subpixel units of N colors, in which N is a positive integer, and <NUM>≤i≤N. There is also no overlap area between the projection of the photoelectric sensing layer <NUM> on the substrate <NUM> and projections of the subpixel units on the substrate <NUM>.

In some embodiments, N may be <NUM>. That is to say, the display panel <NUM> may include subpixel units of <NUM> colors. The subpixel units of <NUM> colors may be a red subpixel unit, a green subpixel unit and a blue subpixel unit. Wherein, the subpixel unit may also be referred to as subpixel. The luminous color of the pixel unit may be determined by the luminous intensity of the subpixel units of <NUM> colors.

In some embodiments, referring to <FIG> and <FIG>, the pixel layer <NUM> may include a liquid crystal layer <NUM>, a color filter layer (not shown) and a Black Matrix BM. The liquid crystal layer <NUM> may be disposed on the substrate <NUM>. The color filter layer may be disposed on the liquid crystal layer <NUM> and may include subpixel units of <NUM> colors CF1, CF2 and CF3 arranged in an array. The Black Matrix BM may be disposed between adjacent subpixel units. The photoelectric sensing layer <NUM> may be disposed on the Black Matrix BM and disposed at a side of the Black Matrix BM away from the liquid crystal layer <NUM>. As the Black Matrix BM is disposed between the adjacent subpixel units and the photoelectric sensing layer <NUM> is disposed on the Black Matrix BM, it is ensured that there is no overlap area between the projection of the photoelectric sensing layer on the substrate and the projection of the subpixel units on the substrate, so as to not affect the display effect.

In some embodiments, the subpixel unit CF1 may be a red film layer, the subpixel unit CF2 may be a green film layer, and the subpixel unit CF3 may be a blue film layer. When the liquid crystal layer <NUM> is in light transmission state, light transmitted from the liquid crystal layer <NUM> pass through the subpixel unit CF1 and then emitted from the subpixel unit CF1 is red light; light transmitted from the liquid crystal layer <NUM> pass through the subpixel unit CF2 and then emitted from the subpixel unit CF2 is green light; and light transmitted from the liquid crystal layer <NUM> pass through the subpixel unit CF3 and then emitted from the subpixel unit CF3 is blue light. The Black Matrix BM is light-proof and configured to isolate the subpixel units CF1, the subpixel units CF2 and the subpixel units CF3.

In some embodiments, the photoelectric sensing layer <NUM> may be configured to detect the optical parameters of the ambient light. The photoelectric parameters may be light intensity, chroma, color temperature, and the like. For instance, the photoelectric sensing layer <NUM> may be configured to detect the light intensity of the ambient light. The terminal device may adjust the intensity of backlight according to the detected light intensity of the ambient light, so that the display effect of the screen is within a comfortable brightness range acceptable by the human eyes.

In some embodiments, the material of the photoelectric sensing layer <NUM> may be indium tin oxide (ITO) or bismuth tungstate (Bi2WO6), but not limited thereto.

In some embodiments, the photoelectric sensing layer <NUM> is integrally formed with the display panel.

It should be noted that the subpixel units of <NUM> colors may also be subpixel units of other colors. N may also be other numbers, not limited to the cases listed in the embodiments of the present disclosure.

Some embodiments of the present disclosure further provide a display panel. Referring to <FIG> and <FIG>, the display panel <NUM> is an LCD display panel. The display panel <NUM> may also include a visible light selective transmission layer <NUM>.

In some embodiments, the visible light selective transmission layer <NUM> may be disposed on the photoelectric sensing layer <NUM> and is configured to allow visible light in a specified wavelength range in the ambient light to pass through and transmit the visible light to the photoelectric sensing layer <NUM>. Thus, the visible light in the specified wavelength range in the ambient light can pass through the visible light selective transmission layer <NUM> and be transmitted to the photoelectric sensing layer <NUM>.

In some embodiments, the visible light selective transmission layer <NUM> may be an optical grating. The parameters of the optical grating may be determined according to the visible light in the specified wavelength range. The optical grating may be manufactured by ultraviolet irradiation method or other methods. The structure of the above optical grating can be: ITO/PVK:m-MTDATA(<NUM>)/NPB(<NUM>)/Alq(<NUM>)/LiF(<NUM>)/Al
wherein PVK refers to polyvinyl carbazole; m-MTDATA refers to <NUM>,<NUM>',<NUM>'-tris(N-<NUM>-methylphenyl-N-phenylamino)triphenylamine; the doping ratio of PVK to m-MTDATA may be <NUM> : <NUM>; NPB refers to N,N'-bis(<NUM>-naphthyl)-N,N'-diphenyl-<NUM>, <NUM>'-biphenyl-<NUM>-<NUM>'-diamine; Alq refers to hydroxyquinoline aluminum salt; LiF refers to lithium fluoride; and Al refers to aluminum. The thickness of PVK:m-MTDATA is <NUM>; the thickness of NPB is <NUM>; the thickness of Alq is <NUM>; and the thickness of LiF is <NUM>. It should be noted that the structure of the optical grating is not limited to the above structure and may also be other structures.

In some embodiments, the photoelectric sensing layer <NUM> includes N sub-photoelectric sensing layers. The N sub-photoelectric sensing layers include the first sub-photoelectric sensing layer, the second sub-photoelectric sensing layer,. , the ith sub-photoelectric sensing layer,. , the Nth sub-photoelectric sensing layer, in which N is a positive integer, and <NUM> ≤ i≤N.

In some embodiment, the visible light selective transmission layer <NUM> includes N sub-visible light selective transmission layers. The N sub-visible light selective transmission layers include the first sub-visible light selective transmission layer,. , the ith sub-visible light selective transmission layer,. , the Nth sub-visible light selective transmission layer. Wherein, the ith sub-visible light selective transmission layer is disposed on the ith sub-photoelectric sensing layer and allows visible light in the ith wavelength range to pass through; and the wavelength range of light emitted by subpixel units of the ith color is the same with the ith wavelength range.

In some embodiments, N is <NUM>. The visible light selective transmission layer <NUM> may allow visible light in the first wavelength range, the second wavelength range and the third wavelength range in the ambient light to pass through. The wavelength range of light emitted by the red subpixel unit is the same with the first wavelength range; the wavelength range of light emitted by the green subpixel unit is the same with the second wavelength range; and the wavelength range of light emitted by the blue subpixel unit is the same with the third wavelength range. Thus, the visible light in other wavelength ranges in the ambient light entering the display panel can be eliminated, and then the display effect can be improved.

In some embodiments, the photoelectric sensing layer <NUM> may include a first sub-photoelectric sensing layer <NUM>, a second sub-photoelectric sensing layer <NUM> and a third sub-photoelectric sensing layer <NUM>. The visible light selective transmission layer <NUM> may include a first sub-visible light selective transmission layer <NUM>, a second sub-visible light selective transmission layer <NUM> and a third sub-visible light selective transmission layer <NUM>. The first sub-visible light selective transmission layer <NUM> may be disposed on the first sub-photoelectric sensing layer <NUM>; the second sub-visible light selective transmission layer <NUM> may be disposed on the second sub-photoelectric sensing layer <NUM>; and the third sub-visible light selective transmission layer <NUM> may be disposed on the third sub-photoelectric sensing layer <NUM>.

In some embodiments, the first sub-visible light selective transmission layer <NUM> may allow the visible light in the first wavelength range to pass through; the second sub-visible light selective transmission layer <NUM> may allow the visible light in the second wavelength range to pass through; and the third sub-visible light selective transmission layer <NUM> may allow the visible light in the third wavelength range to pass through. Thus, the visible light in the first wavelength range in the ambient light may pass through the first sub-visible light selective transmission layer <NUM> and be transmitted to the first sub-photoelectric sensing layer <NUM>, and the first sub-photoelectric sensing layer <NUM> may detect the first light intensity of the visible light in the first wavelength range in the ambient light.

Similarly, the visible light in the second wavelength range in the ambient light may pass through the second sub-visible light selective transmission layer <NUM> and be transmitted to the second sub-photoelectric sensing layer <NUM>, and the second sub-photoelectric sensing layer <NUM> may detect the second light intensity of the visible light in the second wavelength range in the ambient light.

Similarly, the visible light in the third wavelength range in the ambient light may pass through the third sub-visible light selective transmission layer <NUM> and be transmitted to the third sub-photoelectric sensing layer <NUM>, and the third sub-photoelectric sensing layer <NUM> may detect the third light intensity of the visible light in the third wavelength range in the ambient light.

Therefore, the terminal device may obtain the optical parameters of the ambient light according to the first light intensity, the second light intensity and the third light intensity. The optical parameters may be light intensity, color temperature or chromaticity coordinate. For instance, the terminal device may obtain the light intensity of the ambient light according to the first light intensity, the second light intensity and the third light intensity. The terminal device may also obtain the color temperature or the chromaticity coordinate of the ambient light according to the first light intensity, the second light intensity and the third light intensity.

In some embodiments, referring to <FIG>, a projection of the photoelectric sensing layer <NUM> on the substrate <NUM> falls within a projection of the visible light selective transmission layer <NUM> on the substrate <NUM>. More specifically, a projection of the first sub-photoelectric sensing layer <NUM> on the substrate <NUM> falls within a projection of the first sub-visible light selective transmission layer <NUM> on the substrate <NUM>; a projection of the second sub-photoelectric sensing layer <NUM> on the substrate <NUM> falls within a projection of the second sub-visible light selective transmission layer <NUM> on the substrate <NUM>; and a projection of the third sub-photoelectric sensing layer <NUM> on the substrate <NUM> falls within a projection of the third sub-visible light selective transmission layer <NUM> on the substrate <NUM>. In this way, only light passing through the visible light selective transmission layer <NUM> can be detected by the photoelectric sensing layer <NUM>, thereby avoiding visible light except the visible light in the specified wavelength ranges from being transmitted to the photoelectric sensing layer <NUM> and improving the accuracy in the detection of the optical parameters of the ambient light.

In some embodiments, the projection area of the photoelectric sensing layer <NUM> on the substrate <NUM> is greater than the specified area. Or in some embodiments, the projections of the photoelectric sensing layer <NUM> on the substrate <NUM> are uniformly distributed and may basically cover the substrate <NUM>. Thus, the photosensitive area is enhanced, and then the sensitivity in the detection of the ambient light can be enhanced. Of course, in some embodiments, the projection area of the photoelectric sensing layer <NUM> on the substrate <NUM> may also be greater than the specified area, and the projections on the substrate <NUM> are uniformly distributed.

In some embodiments, a surface of the visible light selective transmission layer <NUM> away from the substrate <NUM> may be basically level and parallel to a surface of the color filter layer from the substrate <NUM>. In some embodiments, when the surface of the visible light selective transmission layer <NUM> away from the substrate <NUM> and the surface of the color filter layer away from the substrate <NUM> are not in the same horizontal plane, transparent optical cement may be filled on the surface of the visible light selective transmission layer <NUM> away from the substrate <NUM> and the surface of the color filter layer away from the substrate <NUM> to obtain a planarization layer to provide smooth support for other film layers above.

In some embodiments, referring to <FIG>, the display panel <NUM> may also include a polarizer <NUM> which is configured to avoid the ambient light entering the display panel from being emitted from a light-emitting surface of the display panel and affecting the display effect. In some embodiments, the light-emitting surface of the display panel may be a polarizer side of the display panel.

Some embodiments of the present disclosure further provide a display panel. Referring to <FIG> and <FIG>, the display panel <NUM> is an OLED display panel.

In some embodiments, the display panel <NUM> includes a substrate <NUM>, a pixel layer <NUM>, a photoelectric sensing layer <NUM> and a visible light selective transmission layer <NUM>. The photoelectric sensing layer <NUM> and the visible light selective transmission layer <NUM> are respectively similar to the photoelectric sensing layer <NUM> and the visible light selective transmission layer <NUM> in some embodiments as shown in <FIG>, and no further description will be given here.

In some embodiments, the pixel layer <NUM> includes organic light-emitting layers <NUM>, <NUM> and <NUM> and a pixel define layer (PIXEL DEFINITION LAYER) <NUM>. In some embodiments, the display panel <NUM> also includes an array layer <NUM> which is disposed between the substrate <NUM> and the organic light-emitting layers <NUM>, <NUM> and <NUM>. The organic light-emitting layers <NUM>, <NUM> and <NUM> may include organic light-emitting layers <NUM> of red subpixel units, organic light-emitting layers <NUM> of green subpixel units, and organic light-emitting layers <NUM> of blue subpixel units.

In some embodiments, there is no overlap area between projections of the organic light-emitting layers <NUM>, <NUM> and <NUM> on the substrate <NUM> and projections of the first photoelectric sensing layer <NUM>, the second photoelectric sensing layer <NUM> and the third photoelectric sensing layer <NUM> on the substrate <NUM>.

In some embodiments, referring to <FIG>, the first sub-photoelectric sensing layer <NUM>, the second sub-photoelectric sensing layer <NUM> and the third sub-photoelectric sensing layer <NUM> may be disposed between organic light-emitting layers of adjacent subpixel units. In some embodiments, referring to <FIG>, any one of the first sub-photoelectric sensing layer <NUM>, the second sub-photoelectric sensing layer <NUM> and the third sub-photoelectric sensing layer <NUM> may also be disposed between organic light-emitting layers of adjacent subpixel units.

In some embodiments, the array layer <NUM> may include a drive circuit layer <NUM> and an anode layer <NUM>. The drive circuit layer <NUM> is disposed on the substrate <NUM>; the anode layer <NUM> is disposed on the drive circuit layer <NUM>; and the organic light-emitting layers <NUM>, <NUM> and <NUM> are disposed on the anode layer <NUM>.

In some embodiments, the photoelectric sensing layer <NUM> may be disposed at a side of the substrate <NUM> distal (away) from the pixel layer <NUM>, namely the photoelectric sensing layer <NUM> may be disposed on the back of the substrate <NUM>. When the photoelectric sensing layer <NUM> is disposed at a side of the substrate <NUM> away from the pixel layer <NUM>, the substrate <NUM> is a transparent substrate, and the light transmittance of the array layer <NUM> is greater than the specified light transmittance. For instance, the specified light transmittance may be <NUM>%, but not limited thereto.

In some embodiments, the photoelectric sensing layer <NUM> may also be disposed at a side of the substrate <NUM> proximal to the pixel layer <NUM>. When the photoelectric sensing layer <NUM> is disposed at a side of the substrate <NUM> proximal to the photoelectric sensing layer on the substrate and a projection of the pixel unit on the substrate.

In some embodiments, the display panel can also comprise:
a visible light selective transmission layer disposed on the photoelectric sensing layer and configured to allow visible light in a specified wavelength range in the ambient light to pass through and transmit the visible light to the photoelectric sensing layer.

In some embodiments, the pixel unit includes subpixel units of N colors;.

In some embodiments, a projection of the photoelectric sensing layer on the substrate may fall within a projection of the visible light selective transmission layer on the substrate.

In some embodiments, the pixel layer may include:.

In some embodiments, the pixel layer may include an organic light-emitting layer; the display panel further comprises:.

In some embodiments, a projection area of the photoelectric sensing layer on the substrate may be greater than a specified area; and/or
a projection of the photoelectric sensing layer on the substrate may be uniformly distributed.

In some embodiments, the visible light selective transmission layer may include an optical grating.

In some embodiments, the terminal device may also comprise a driver chip, wherein the photoelectric sensing layer is electrically connected with the driver chip.

The technical solution provided by various embodiments of the present disclosure can have the following advantages.

As the photoelectric sensing layer is disposed at a side of the substrate away from the pixel layer or disposed at a side of the substrate proximal to the pixel layer in the display panel, the foregoing photoelectric sensing layer may be configured to detect the optical parameters of ambient light. Since the cost of integrating the photoelectric sensing layer in the display panel is lower than that of separately arranging an independent optical sensor on the outside of the display panel, the cost of the terminal device in detecting the optical parameters of the ambient light can be reduced.

It is to be noted that in the accompanying drawings, the dimension of layers and regions may be exaggerated for clarity of illustration. It is also understood light-emitting layer; the display panel further comprises:.

The technical solution provided by viarious embodiments of the present disclosure can have the following advantages.

As the photoelectric sensing layer is disposed at a side of the substrate distal from the pixel layer or disposed at a side of the substrate proximal to the pixel layer in the display panel, the foregoing photoelectric sensing layer may be configured to detect the optical parameters of ambient light. Since the cost of integrating the photoelectric sensing layer in the display panel is lower than that of separately arranging an independent optical sensor on the outside of the display panel, the cost of the terminal device in detecting the optical parameters of the ambient light can be reduced.

It is to be noted that in the accompanying drawings, the dimension of layers and regions may be exaggerated for clarity of illustration. It is also understood that when an element or layer is referred to as "on" another element or layer, it may be that when an element or layer is referred to as "on" another element or layer, it may be directly on the other element or an intermediate layer may be present. In addition, it is to be understood that when an element or layer is referred to as "under" another element or layer, it may be directly beneath the other element or more than one intermediate layer or elements may be present. In addition, it is to be understood that when a layer or element is referred to as being "between" two layers or two elements, it may be a single layer between two layers or two elements, or more than one intermediate layer or elements may be present. Similar reference numerals indicate similar elements.

In the present invention, the terms "first" and "second" are used for descriptive purpose only, and are not to be construed as indicating or implying relative importance. The term "a plurality of" means two or more than two, unless expressly defined otherwise.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed here. This application is intended to cover any variations, uses, or adaptations of the invention following the general principles thereof and including such departures from the present disclosure as come within known or customary practice in the art. It is intended that the specification and examples be considered as exemplary only, with a true scope of the invention being indicated by the following claims.

Claim 1:
A display panel (<NUM>), comprising:
a substrate (<NUM>); and
a pixel layer (<NUM>) disposed on the substrate (<NUM>) and including pixel units (CF) arranged in an array,
characterized in that the display panel (<NUM>) further comprises:
a photoelectric sensing layer (<NUM>) disposed on a back of the substrate <NUM> or disposed at a same side of the substrate (<NUM>) with the pixel layer (<NUM>),
wherein the photoelectric sensing layer (<NUM>) is configured to detect a light intensity of ambient light to adjust an intensity of backlight according to the detected light intensity of the ambient light.