A display apparatus, comprising: a first substrate; a plurality of pixels on the first substrate, each pixel of the pixels including a pixel region and a transmitting region adjacent to the pixel region, the pixel region emitting light in a first direction and the transmitting region transmitting external light; a second substrate that faces the first substrate and seals the pixels; an optical filter arranged at the front of the display apparatus through which light is emitted, the optical filter being configured to transmit circularly polarized light that rotates in a predetermined direction; and an optical reflectance conversion device arranged at the back of the display apparatus, the optical reflectance conversion device being configured to change a reflectance of the external light according to a plurality of modes of operation of the display apparatus, the plurality of modes of operation including a first mode, a second mode, and a third mode, wherein, in the first mode, the optical reflectance conversion device transmits the external light that enters through the optical filter and the display device and wherein, in the second mode, the optical reflectance conversion device reflects the external light entering through the optical filter and the display device and wherein, in the third mode, the optical reflectance conversion device reflects an external light portion of the external light entering through the optical filter and the display device and transmits the other external light portion of the external light, wherein each pixel of the pixels includes: a pixel circuit unit in the pixel region on the first substrate, the pixel circuit unit including at least one thin-film transistor; a first insulating film covering at least the pixel circuit unit; a first electrode on the first insulating film and electrically connected to the pixel circuit unit; a second electrode facing the first electrode; and an organic film between the first electrode and the second electrode, the organic film including a light-emitting layer. a first substrate; a plurality of pixels on the first substrate, each pixel of the pixels including a pixel region and a transmitting region adjacent to the pixel region, the pixel region emitting light in a first direction and the transmitting region transmitting external light; a second substrate that faces the first substrate and seals the pixels; an optical filter arranged at the front of the display apparatus through which light is emitted, the optical filter being configured to transmit circularly polarized light that rotates in a predetermined direction; and an optical reflectance conversion device arranged at the back of the display apparatus, the optical reflectance conversion device being configured to change a reflectance of the external light according to a plurality of modes of operation of the display apparatus, the plurality of modes of operation including a first mode, a second mode, and a third mode, wherein, in the first mode, the optical reflectance conversion device transmits the external light that enters through the optical filter and the display device and wherein, in the second mode, the optical reflectance conversion device reflects the external light entering through the optical filter and the display device and wherein, in the third mode, the optical reflectance conversion device reflects an external light portion of the external light entering through the optical filter and the display device and transmits the other external light portion of the external light, wherein each pixel of the pixels includes: a pixel circuit unit in the pixel region on the first substrate, the pixel circuit unit including at least one thin-film transistor; a first insulating film covering at least the pixel circuit unit; a first electrode on the first insulating film and electrically connected to the pixel circuit unit; a second electrode facing the first electrode; and an organic film between the first electrode and the second electrode, the organic film including a light-emitting layer. a pixel circuit unit in the pixel region on the first substrate, the pixel circuit unit including at least one thin-film transistor; a first insulating film covering at least the pixel circuit unit; a first electrode on the first insulating film and electrically connected to the pixel circuit unit; a second electrode facing the first electrode; and an organic film between the first electrode and the second electrode, the organic film including a light-emitting layer.