Display device and display method for reducing power consumption of a source driver

A display method used by a display device that includes:

• a plurality of pixel units;
• a source driver that applies, to data signal lines connected to the pixel units, voltages corresponding to gray-level values of display pixels included in an image indicated by an image signal;
• and a control unit configured to control operations of the pixel units and the source driver, wherein each of the pixel units includes (i) a light-emitting element that emits light according to a driving current, (ii) a capacitance element that accumulates electrical charge corresponding to a voltage among the voltages which is applied to a data signal line connected to the pixel unit among the data signal lines, and (iii) a driving transistor that supplies the driving current corresponding to the electrical charge accumulated in the capacitance element to the light-emitting element, and the driving transistor is a P-channel transistor, the display method comprising
• decreasing at least one of the voltages to be outputted from the source driver, when an appearance frequency of at least one display pixel having a low gray-level value lower than or equal to a first reference value among the display pixels is lower than a first reference frequency, or when an appearance frequency of at least one display pixel having a high gray-level value higher than or equal to a second reference value among the display pixels is lower than a second reference frequency.