1. Technical Field
The present invention relates to display devices and electronic apparatuses including the display devices.
2. Related Art
To date, devices and methods of extracting light components of a plurality of colors from a single light-emitting layer using optical resonance have been proposed (for example, see Japanese Patent No. 2,797,883). Japanese Patent No. 2,797,883 describes a color display device with a simple structure. However, the thicknesses of transparent electrodes need to be changed in accordance with the emission colors of the pixels, and additional production processes such as etching are required. This leads to an increase in cost.
JP-A-2004-111398 describes a technology using a resonant structure and adjusting of resonant optical path lengths to the least common multiples of the central wavelengths of colors of light-emitting elements. This technology is intended to achieve improvements in chromatic purity and extraction efficiency of light components, which are effects of the resonant structure. Since layers that constitute the resonant structure can be used in common with the light-emitting elements of any color in this technology, the production process can be simplified.
However, the structure described in JP-A-2004-111398 is predicated on the bottom emission type. In the bottom emission structure, the brightness of the emitted light tends to be reduced since the light is emitted through the substrate. Moreover, a large aperture ratio cannot be ensured as compared with the top emission structure since thin-film transistors or wiring lines for driving the light-emitting elements are disposed between the substrate and the light-emitting elements.
Moreover, a translucent half-reflecting film formed of a thin metallic film is disposed between the light-emitting layer and the substrate such that the chromatic purity of light is enhanced by the reciprocation of the light between a cathode layer and the translucent half-reflecting film in this structure. However, it is difficult to produce the translucent half-reflecting film having desired transparency and reflectivity in a uniform manner, and the characteristics of actual products can be unstable when the improvement in the chromatic purity depends only on the translucent half-reflecting film.
USPTO Backgrounds
USPTO Backgrounds