Electronic device and operation method thereof
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsRyo HATSUMI, Hisao IKEDA, Daiki NAKAMURA, Tomotaka NISHIMURA
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Abstract
An electronic device with good visibility of display is provided. The electronic device includes a reflective liquid crystal display device for displaying information, and part of external light taken into the electronic device can be supplied to the reflective liquid crystal display device to be used as a light source of display light. Thus, the visibility of display can be increased even when external light is intense. Furthermore, since external light is utilized for display, power consumption can be reduced compared with a transmissive liquid crystal display device that constantly uses a light source, a self-luminous organic EL display device, and the like.
Claims16
An electronic device comprising:
- a reflective liquid crystal display device, a planar light source, a reflective polarizing plate, a first retardation plate, and a half mirror,
- wherein a display surface of the reflective liquid crystal display device faces a light-emitting surface of the planar light source,
- wherein the reflective polarizing plate is positioned at an angle at which light that is emitted from the display surface and travels straight through the planar light source is incident obliquely, and
- wherein the reflective polarizing plate, the first retardation plate, and the half mirror are positioned in this order in a direction in which the light reflected by the reflective polarizing plate travels.
An electronic device comprising:
- a transflective liquid crystal display device, a planar light source, a reflective polarizing plate, a retardation plate, and a half mirror,
- wherein a surface opposite to a display surface of the transflective liquid crystal display device faces a light-emitting surface of the planar light source,
- wherein the reflective polarizing plate is positioned at an angle at which light that is emitted from the display surface and travels straight is incident obliquely, and
- wherein the reflective polarizing plate, the retardation plate, and the half mirror are positioned in this order in a direction in which the light reflected by the reflective polarizing plate travels.
A method for operating an electronic device comprising a reflective liquid crystal display device or a transflective liquid crystal display device on which first light is incident from a first light source and second light is incident from a second light source, the method comprising:
- obtaining a first illuminance and a first chromaticity of the first light emitted from the first light source;
- changing a second illuminance of the second light source so as to have a negative slope with respect to the first illuminance;
- and
- changing a second chromaticity of the second light emitted from the second light source in accordance with the first chromaticity such that a color of combined light of the first light and the second light is close to white light.
Dependencies are inferred from the claim text.