Display device

A display device that is a reflective display device comprising:

• a display unit including a plurality of pixels;
• a lighting unit emitting light to the display unit;
• a measurement unit measuring an intensity of external light serving as light other than internal light out of light with which the display unit is irradiated, the internal light emitting from the lighting unit;
• and
• a control unit controlling an intensity of the internal light and a gradation value of each of the pixels based on the intensity of the external light measured by the measurement unit, wherein
• the control unit calculates a required luminance value for a luminance value of a pixel to be N times (N>0) as high as a luminance value indicated by an input signal, the pixel performing output with the largest gradation value out of the pixels included in a predetermined image display region in the display unit,
• the control unit determines the intensity of the internal light based on a result of comparison between the intensity of the external light and the required luminance value, and
• the control unit calculates an output gradation value of each of the pixels based on Equation (1):
• O=I×N/(OL+IL) (1)
• where OL denotes the intensity of the external light, IL denotes the intensity of the internal light, I denotes the gradation value indicated by the input signal, and O denotes the output gradation value of the pixel.