Semiconductor Energy Laboratory Co., Ltd.

Yukari Ando

Jun Koyama

Masahiko Hayakawa

Keisuke Miyagawa

Shunpei Yamazaki

Yu Yamazaki

Hajime Kimura

Mitsuaki Osame

Aya Anzai

Satoshi Seo

Hiroko Abe

Yu Kojima

Tomoyuki Iwabuchi

A display device having a pixel configuration in which the aperture ratio is not decreased, and a driving method of a display device in which the duty ratio and the reliability of a light emitting element are increased. According to the invention, a signal line for inputting an analog signal, a first switch controlled by a first scan line, a second switch controlled by a second scan line, and a light emitting element connected to the second switch are included, wherein the first switch and the second switch are selected and an analog signal is inputted in a first period of one gate selection period, the first switch is selected and a reference signal is inputted from the signal line in a second period of the one gate selection period, and the light emitting element emits light by the analog signal and the reference signal.

Display device and driving method thereof

A light emitting element has a property that a resistance value (internal resistance value) thereof changes according to the ambient temperature. Specifically, assuming that the room temperature is a normal temperature, when the ambient temperature becomes higher than the normal temperature, a resistance value is decreased, and when the ambient temperature becomes lower than the normal temperature, a resistance value is increased. Therefore, when the ambient temperature changes or degradation is caused with time due to the aforementioned property of the light emitting element, luminance varies. The invention provides a display device where an effect of current fluctuation of a light emitting element, which is caused by the change in ambient temperature and degradation with time, is suppressed. The display device comprises a monitoring element, to which a current is supplied from a current source. A voltage applied to the monitoring element is applied to a light emitting element.

Display device, driving method thereof and electronic appliance

The brightness of a light emitting element varies when changes in ambient temperature or changes with time occur. In view of this, the invention provides a display device where the influence of variations in the current value of the light emitting element due to changes in ambient temperature and changes with time can be suppressed. The display device of the invention includes a monitoring element that is driven with a constant current, and a voltage applied to the monitoring element is detected and inputted to a light emitting element. In other words, the monitoring element is driven with a low current, and a voltage applied to the monitoring element is inputted to the light emitting element such that the light emitting element is driven with a constant current.

Display device and driving method of the same, and electronic apparatus

The luminance of light emitting elements varies when the characteristics thereof change due to changes in environment temperature and changes with time. It is an object of the present invention to suppress the effect of the change in current value of a light emitting element due to the changes of environment temperature and changes with time. The invention provides a display device provided with a compensation function for the changes in environment temperature and a compensation function for the change with time. The display device of the invention includes a light emitting element, a driving transistor connected to the light emitting element, and a monitoring light emitting element. By using this monitoring light emitting element, an effect of the change of current value of the light emitting element due to the change of environment temperature and change with time can be suppressed.

Display device and electronic device

A display device where the influence of variations in current of the light emitting element due to changes in ambient temperature and changes with time can be suppressed. The display device of the invention has a light emitting element, a driving transistor connected in series to the light emitting element, a monitoring light emitting element, a limiter transistor connected in series to the monitoring light emitting element, a constant current source for supplying a constant current to the monitoring light emitting element, and a circuit for outputting a potential equal to an inputted potential. A first electrode of the light emitting element is connected to an output terminal of the circuit through the driving transistor, and a first electrode of the monitoring light emitting element is connected to an input terminal of the circuit through the limiter transistor. The channel length Land the channel width Wof the driving transistor, and the channel length Land the channel width Wof the limiter transistor satisfy L/W:L/W=1:2 to 1:10.

A display device where the influence of variations in current of the light emitting element due to changes in ambient temperature and changes with time can be suppressed. The display device of the invention has a light emitting element, a driving transistor connected in series to the light emitting element, a monitoring light emitting element, a limiter transistor connected in series to the monitoring light emitting element, a constant current source for supplying a constant current to the monitoring light emitting element, and a circuit for outputting a potential equal to an inputted potential. A first electrode of the light emitting element is connected to an output terminal of the circuit through the driving transistor, and a first electrode of the monitoring light emitting element is connected to an input terminal of the circuit through the limiter transistor. The channel length Land the channel width Wof the driving transistor, and the channel length Land the channel width Wof the limiter transistor satisfy L/W: L/W=1:2 to 1:10.

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Gifu, Japan

Yukari Ando