Display device, display module including the display device, and electronic device including the display device or the display module
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsYasuhiro Niikura, Makoto Ikenaga, Daisuke Kubota, Ryo Hatsumi
Life of this patent
Estimating the term…
Abstract
Provided is a novel display device without deterioration of display quality or a novel display device in which flickering due to a reduced refresh rate is suppressed. The display device includes a pixel for displaying a still image at a frame frequency of less than or equal to 1 Hz. The pixel includes a liquid crystal layer. The liquid crystal layer includes a molecule whose dipole moment is greater than or equal to 0 debye and less than or equal to 3 debye. Thus, flickering due to a reduced refresh rate can be suppressed, which leads to an improvement in display quality.
Claims10
A display device comprising:
- a pixel comprising:
- a transistor comprising an oxide semiconductor in a channel thereof;
- a pixel electrode electrically connected to the transistor;
- and
- a liquid crystal layer over the pixel electrode;
- and
- a driver circuit for outputting a signal to the pixel,
- wherein:
- the liquid crystal layer comprises a liquid crystal mixture formed only of materials having a dipole moment of 3 debye or less,
- the liquid crystal layer has a resistivity of 1.0×1014 (Ω·cm) or more,
- the driver circuit is configured to switch a first mode in which the signal for a moving image is output to the pixel at a frequency of 30 Hz or more, and a second mode in which the signal for a still image is output to the pixel at a frequency of 1 Hz or less, and
- the pixel is configured to display the still image at a frame frequency of 1/30 Hz to 1 Hz.
A display device comprising:
- a pixel comprising:
- a transistor comprising an oxide semiconductor in a channel thereof;
- a reflective electrode electrically connected to the transistor;
- and
- a liquid crystal layer over the reflective electrode;
- and
- a driver circuit for outputting a signal to the pixel,
- wherein:
- the reflective electrode has a projection and a depression,
- the liquid crystal layer comprises a liquid crystal mixture formed only of materials having a dipole moment of 3 debye or less,
- the liquid crystal layer has a resistivity of 1.0×1014 (Ω·cm) or more,
- the driver circuit is configured to switch a first mode in which the signal for a moving image is output to the pixel at a frequency of 30 Hz or more, and a second mode in which the signal for a still image is output to the pixel at a frequency of 1 Hz or less, and
- the pixel is configured to display the still image at a frame frequency of 1/30 Hz to 1 Hz.
Dependencies are inferred from the claim text.