We Claim:
1. An electronic device, comprising a light sensor (21) and a microcontroller (22) connected
to the light sensor (21), wherein
the light sensor (21) is configured to acquire an ambient luminance signal of a current time point; and
the microcontroller (22) is configured to: read the ambient luminance signal of the current time point from the light sensor (21), and obtain through calculation a first target backlight brightness value of the electronic device at the current time point according to the ambient luminance signal of the current time point, wherein
the microcontroller (22) is further configured to: if the electronic device is in a normal screen-on state, adjust from a first initial backlight brightness value to the first target backlight brightness value step by step, wherein the first initial backlight brightness value is a first target backlight brightness value of the electronic device at a previous time point.
2. The electronic device according to claim 1, wherein the microcontroller (22) is specifically
configured to:
perform filtering processing on the read ambient luminance signal of the current time point to obtain an after-filtering ambient luminance signal of the current time point; and
if the after-filtering ambient luminance signal of the current time point changes relative to an ambient luminance signal of the previous time point, obtain through calculation the first target backlight brightness value of the electronic device at the current time point according to the after-filtering ambient luminance signal of the current time point.
3. The electronic device according to claim 1, wherein the microcontroller (22) is specifically
configured to:
acquire an initial brightness change rate corresponding to the first initial backlight brightness value, and adjust to a first first intermediate backlight brightness value according to the initial brightness change rate; and
obtain an intermediate brightness change rate corresponding to a first intermediate backlight brightness value, and adjust to a next first intermediate backlight brightness value according to the intermediate brightness change rate, cyclically until the first target backlight brightness value of the electronic device is reached.

4. The electronic device according to any one of claims 1 to 3, wherein the electronic device
further comprises: an application processor (23), a display driver module connected to the
application processor (23) and the microcontroller (22), and a backlight driver module connected
to the microcontroller (22), wherein
the application processor (23) is configured to output an image to the display driver module;
the display driver module is configured to acquire a second target backlight brightness value of the electronic device at the current time point according to the image input by the application processor(23);
the microcontroller (22) is configured to: multiply the first target backlight brightness value and the second target backlight brightness value to obtain a third target backlight brightness value of the electronic device, and output the third target backlight brightness value to the backlight driver module; and
the backlight driver module is configured to adjust backlight brightness of the electronic device according to the third target backlight brightness value.
5. The electronic device according to claim 4, wherein
the application processor (23) is further configured to send an instruction message to the microcontroller (22), wherein the instruction message is used to instruct the microcontroller (22) to turn on or turn off the light sensor (21).
6. A method for adjusting backlight brightness, applied to an electronic device, wherein the
adjustment method comprises:
acquiring (701) an ambient luminance signal of a current time point;
obtaining (702) through calculation a first target backlight brightness value of the electronic device at the current time point according to the ambient luminance signal of the current time point; and
if the electronic device is in a normal screen-on state, adjusting (703) from a first initial backlight brightness value to the first target backlight brightness value step by step, wherein the first initial backlight brightness value is a first target backlight brightness value of the electronic device at a previous time point.

7. Ihe adjustment method according to claim 6, wherein the obtaining through calculation a
first target backlight brightness value of the electronic device at the current time point according
to the ambient luminance signal of the current time point comprises:
performing filtering processing on the ambient luminance signal of the current time point to obtain an after-filtering ambient luminance signal of the current time point; and
if the after-filtering ambient luminance signal of the current time point changes relative to an ambient luminance signal of the previous time point, obtaining through calculation the first target backlight brightness value of the electronic device at the current time point according to the after-filtering ambient luminance signal of the current time point.
8. The adjustment method according to claim 6, wherein the adjusting from a first initial
backlight brightness value to the first target backlight brightness value step by step comprises:
acquiring an initial brightness change rate corresponding to the first initial backlight brightness value, and adjusting to a first first intermediate backlight brightness value according to the initial brightness change rate; and
obtaining an intermediate brightness change rate corresponding to a first intermediate backlight brightness value, and adjusting to a next first intermediate backlight brightness value according to the intermediate brightness change rate, cyclically until the first target backlight brightness value of the electronic device is reached.
9. The adjustment method according to any one of claims 6 to 8, wherein the adjustment
method further comprises:
acquiring (704) a second target backlight brightness value of the electronic device at the current time point according to an image input to the electronic device; and
multiplying (705) the first target backlight brightness value and the second target backlight brightness value to obtain a third target backlight brightness value, so that the electronic device adjusts backlight brightness according to the third target backlight brightness value.