Semiconductor Energy Laboratory Co., Ltd.

Kenichi Wakimoto

Masahiko Hayakawa

Yasuo Nakamura

Akihiro Chida

Kohei Yokoyama

To reduce power consumption of a display device with the use of a simple structure and a simple operation. The display device includes an input device. Input of an image signal to a driver circuit is controlled in accordance with an image operation signal output from the input device. Specifically, input of image signals at the time when the input device is not operated is less frequent than that at the time when the input device is operated. Accordingly, display degradation (deterioration of display quality) caused when the display device is used can be prevented and power consumed when the display device is not used can be reduced.

Display device

An object is to provide a convenient display device which consumes sufficiently small amount of power and a method for driving such a display device. The display device can be in an off state with a still image displayed in a still image display mode in which a pixel electrode and a common electrode which are for applying a voltage to the display element are brought into a floating state so that a voltage applied to the display element is held, and a still image is displayed without further supply of a potential. The display device is put to an off state with a desired image displayed in the still image display mode, whereby the display device can have a higher level of security and can be more convenient.

Method for driving display device

A lighting device including an electroluminescent (EL) material is connected to an external power supply easily and the convenience is improved. In a lighting device having a light-emitting element including an electroluminescence (EL) layer, a housing including a light-emitting element has a terminal electrode electrically connected to the light-emitting element on a peripheral end portion. The terminal electrode provided on the housing so as to be exposed to the outside is in contact with a terminal electrode for the external power supply, so that the external power supply and the light-emitting element are electrically connected to each other and power can be supplied to the lighting device.

Lighting device

A display method suitable for an image provided by a digital data file and/or a display method of a display device in which the image quality and power consumption are adjusted in accordance with the state of the display device or at user's request to display an image. The image is displayed on the display device in which a plurality of pixels having a pixel electrode connected to a switching element whose off-state current is reduced, using the image provided by the digital data file and data which is provided by the digital data file and is correlated to an operation of the display device.

Display method of display device

An object is to suppress degradation of an image quality of a display image. A plurality of display circuits arranged in M rows (M is a natural number of 2 or more) and N columns (N is a natural number) and a light unit are included; the light unit includes a plurality of light-emitting diode groups arranged in X rows (X is a natural number of 2 or more), overlaps with a display circuit in at least different one or more rows every row, and includes a light-emitting diode emitting red light, a light-emitting diode emitting green light and a light-emitting diode emitting blue light and a light guide plate formed between the plurality of display circuits and the plurality of light-emitting diode groups. The light guide plate includes X light guide members which transmits the light of the light-emitting diode groups in the rows different from each other.

Display device and driving method for display device

The still image display mode includes a first period of writing the data of the image signal from the driver circuit portion into the pixel; after the first period, a second period of stopping supply of a signal or voltage for operating the driver circuit portion to the driver circuit portion; and after the second period, a third period of restarting the supply of a signal or voltage for operating the driver circuit portion to the driver circuit portion and writing the data of the image signal into the pixel from the driver circuit portion, so that the pixel keeps displaying a still image. A length of a period from the stop of the supply of the signal for operating the driver circuit portion to the driver circuit portion to the restart is set in accordance with a temperature of the display device.

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Atsugi, Japan

Kenichi Wakimoto