1. Field of the Invention
The present invention relates to a light emitting apparatus fitted with light-emitting devices and, more particularly, to a light emitting apparatus on which a display portion for displaying multiple colors is formed. The invention also relates to a driving method for displaying multiple colors.
2. Description of the Related Art
In recent years, a light emitting apparatus using light-emitting devices that are self-emitting devices have been studied and developed. These light emitting apparatus are widely used as the display screens of mobile phones and as a light emitting apparatus when personal computers are used, by making use of their merits including high image quality, thinness, and lightweight.
In this light emitting apparatus, a known method to display multiple colors consists of fabricating all light-emitting devices of the pixel portion using monochrome light-emitting materials and obtaining desired colors of light using color filters or color conversion layers corresponding to RGB light-emitting devices. In particular, in one type of system, light-emitting devices emitting white light and color filters are combined. In another type of system, light-emitting devices emitting blue light are combined with color conversion layers. In a further known system, a light-emitting material emitting light of a different color is applied to each of RGB light-emitting devices.
When multiple colors are displayed on a light emitting apparatus by the method of fabricating all light-emitting devices of the pixel portion using monochrome light-emitting materials and obtaining desired colors of light using color filters or color conversion layers corresponding to the RGB light-emitting devices, the light transmittances of the color filters or color conversion layers are sometimes not uniform among red (R), green (G), and blue (B)(also simply abbreviated RGB). The apparent brightness obtained by transmission through such a color filter or color conversion layer is (brightness of monochrome light-emitting device)×(light transmittance of color filter or color conversion layer).
Accordingly, even if the light-emitting devices are uniform in brightness, the apparent brightnesses obtained by passage through the color filters or color conversion layers will differ unless the color filters of red (R), green (G), and blue (B) or color conversion layers are uniform in light transmittance.
The manifestation of these brightness variations is not limited to the color filters or color conversion layers. Therefore, color filters or color conversion layers are collectively referred to as colored layers.