A flat panel display, comprising: a pixel unit for displaying an image corresponding to data signals and scan signals; a data driver for receiving video signals and generating the data signals to transmit the data signals to the pixel unit; a scan driver for generating the scan signals to transmit the scan signals to the pixel unit; and a photo sensor configured to sense brightness of peripheral light to control brightness of the image to correspond to the brightness of the peripheral light, characterised in that the photo sensor comprises: a first transistor (M11, M12, M13) whose first electrode is coupled to a first power source, whose second electrode is coupled to a first node (N11, N12, N13), and whose gate electrode is coupled to a second node (N21, N22, N23); a photo diode (PD1, PD2, PD3) comprising a first electrode coupled to the first power source and a second electrode; a second transistor (M21, M22, M23) whose first electrode is coupled to the second electrode of the photo diode (PD1, PD2, PD3), whose second electrode is coupled to the second node (N21, N22, N23), and whose gate electrode is coupled to a first control line; a third transistor (M31, M32, M33) whose first electrode is coupled to the second node (N21, N22, N23), whose second electrode is coupled to the first node (N11, N12, N13), and whose gate electrode is coupled to a reset signal line; a fourth transistor (M41, M42, M43) whose first electrode is coupled to the first node (N11, N12, N13), whose second electrode is coupled to a first output end, and whose gate electrode is coupled to the reset signal line; a fifth transistor (M51, M52, M53) whose first electrode is coupled to the first node (N11, N12, N13), whose second electrode is coupled to a second output end, and whose gate electrode is coupled to a second control line; and a first capacitor (Cst1, Cst2, Cst3) whose first electrode is coupled to the first power source and whose second electrode is coupled to the second node (N21, N22, N23). a pixel unit for displaying an image corresponding to data signals and scan signals; a data driver for receiving video signals and generating the data signals to transmit the data signals to the pixel unit; a scan driver for generating the scan signals to transmit the scan signals to the pixel unit; and a photo sensor configured to sense brightness of peripheral light to control brightness of the image to correspond to the brightness of the peripheral light, characterised in that the photo sensor comprises: a first transistor (M11, M12, M13) whose first electrode is coupled to a first power source, whose second electrode is coupled to a first node (N11, N12, N13), and whose gate electrode is coupled to a second node (N21, N22, N23); a photo diode (PD1, PD2, PD3) comprising a first electrode coupled to the first power source and a second electrode; a second transistor (M21, M22, M23) whose first electrode is coupled to the second electrode of the photo diode (PD1, PD2, PD3), whose second electrode is coupled to the second node (N21, N22, N23), and whose gate electrode is coupled to a first control line; a third transistor (M31, M32, M33) whose first electrode is coupled to the second node (N21, N22, N23), whose second electrode is coupled to the first node (N11, N12, N13), and whose gate electrode is coupled to a reset signal line; a fourth transistor (M41, M42, M43) whose first electrode is coupled to the first node (N11, N12, N13), whose second electrode is coupled to a first output end, and whose gate electrode is coupled to the reset signal line; a fifth transistor (M51, M52, M53) whose first electrode is coupled to the first node (N11, N12, N13), whose second electrode is coupled to a second output end, and whose gate electrode is coupled to a second control line; and a first capacitor (Cst1, Cst2, Cst3) whose first electrode is coupled to the first power source and whose second electrode is coupled to the second node (N21, N22, N23). a first transistor (M11, M12, M13) whose first electrode is coupled to a first power source, whose second electrode is coupled to a first node (N11, N12, N13), and whose gate electrode is coupled to a second node (N21, N22, N23); a photo diode (PD1, PD2, PD3) comprising a first electrode coupled to the first power source and a second electrode; a second transistor (M21, M22, M23) whose first electrode is coupled to the second electrode of the photo diode (PD1, PD2, PD3), whose second electrode is coupled to the second node (N21, N22, N23), and whose gate electrode is coupled to a first control line; a third transistor (M31, M32, M33) whose first electrode is coupled to the second node (N21, N22, N23), whose second electrode is coupled to the first node (N11, N12, N13), and whose gate electrode is coupled to a reset signal line; a fourth transistor (M41, M42, M43) whose first electrode is coupled to the first node (N11, N12, N13), whose second electrode is coupled to a first output end, and whose gate electrode is coupled to the reset signal line; a fifth transistor (M51, M52, M53) whose first electrode is coupled to the first node (N11, N12, N13), whose second electrode is coupled to a second output end, and whose gate electrode is coupled to a second control line; and a first capacitor (Cst1, Cst2, Cst3) whose first electrode is coupled to the first power source and whose second electrode is coupled to the second node (N21, N22, N23).