Semiconductor Energy Laboratory Co., Ltd.

Kazutaka Inukai

Jun Koyama

Shunpei Yamazaki

Toshimitsu Konuma

Mayumi Mizukami

Takeshi Fukunaga

Mitsuaki Osame

Tomoyuki Iwabuchi

Mai Osada

Satoshi Murakami

Etsuko Fujimoto

Satoshi Seo

Hajime Kimura

Yasuko Watanabe

Takeshi Noda

Yasuhiro Sakamoto

Shunpai Yamazaki

A current storing circuit capable of having a small area, a simple structure with the small number of devices, a low consumption current operation and high yield in manufacturing is provided. Applying the current storing circuit to the current-driving type of display device such as an OLED display device can improve the aperture rate of pixels and reliability of the display device as well as highly functionalize the display device. The invention is characterized by using a new semiconductor element in a shape of a transistor having plural drains or sources. When the semiconductor elements is used for both of a writing element and a driving element, reading in and storing a current value and outputting the current can be performed by only the two semiconductor elements, so that the area occupied by the devices would be easily reduced significantly.

Semiconductor element, electric circuit, display device and light-emitting device

An inexpensive light emitting device and inexpensive electric equipment are provided. A substrate on which a semiconductor element or a light emitting element is formed and a color filter are manufactured by separate manufacturing processes, and they are bonded to each other to complete the light emitting device. Thus, the yield of the light emitting device is improved and the manufacture period is shortened.

Light emitting device

There is provided an electronic device in which the deterioration of the device is prevented and an aperture ratio is improved without using a black mask and without increasing the number of masks. In the electronic device, a first electrode () is disposed on another layer different from the layer on which a gate wiring () is disposed as a gate electrode, and a semiconductor layer of a pixel switching TFT is superimposed on the gate wiring () so as to be shielded from a light. Thus, the deterioration of the TFT is suppressed, and a high aperture ratio is realized.

Electronic device

An electro-optical device having a plurality of pixels including a plurality of EL elements, wherein the electro-optical device provides a gray scale display by controlling a period of time at which the plurality of the EL elements emit light in one frame period; the plurality of the EL elements have a first electrode and a second electrode; the first electrode is held at a constant potential; and a potential of the second electrode changes in such a manner that a polarity of an EL driving voltage, which is a difference between the potentials applied to the first and second electrodes, is inverted for each one frame period.

Electro-optical device

There is provided an electronic device having high reliability and high color reproducibility. A pixel structure is made such that a switching FET () and an electric current controlling FET () are formed on a single crystal semiconductor substrate (), and an EL element () is electrically connected to the electric current controlling FET (). The fluctuation in characteristics of the electric current controlling FET () is very low among pixels, and an image with high color reproducibility can be obtained. By taking hot carrier measures in the electric current controlling FET (), the electronic device having high reliability can be obtained.

A display device capable of displaying a picture of vivid colors maintaining a good balance of colors and a good balance of light-emitting brightnesses of the EL elements. The widths of the detour wirings supplying current to the power source feed lines are increased for those EL elements into which a current of a large density flows. This constitution decreases the wiring resistances of the detour wirings, decreases the potential drop through the detour wirings, and suppresses the amount of electric power consumed by the detour wirings.

Display device and electronic device

There is provided an electronic device having high reliability and high color reproducibility. A pixel structure is made such that a switching FET () and an electric current controlling FET () are formed on a single crystal semiconductor substrate (), and an EL element () is electrically connected to the electric current controlling PET (). The fluctuation in characteristics of the electric current controlling FET () is very low among pixels, and an image with high color reproducibility can be obtained. By taking hot carrier measures in the electric current controlling FET (), the electronic device having high reliability can be obtained.

Display device using light-emitting element

Electronic device with light emission for a display

The light emitting device according to the present invention is characterized in that a gate electrode comprising a plurality of conductive films is formed, and concentrations of impurity regions in an active layer are adjusted with making use of selectivity of the conductive films in etching and using them as masks. The present invention reduces the number of photolithography steps in relation to manufacturing the TFT for improving yield of the light emitting device and shortening manufacturing term thereof, by which a light emitting device and an electronic appliance are inexpensively provided.

Light emitting device and manufacturing method thereof

Semiconductor element, electronic device

An AM-OLED display device is provided in which dispersion in OLED element driver currents is sufficiently suppressed is taken as an objective. The present invention places a plurality of transistors into a parallel connection state during write-in of a data current into pixels, and places the plurality of transistors into a series connection state when light emitting elements emit light. As a result, even if dispersions exist between the plurality of transistors structuring a driver element within the same pixel, the influence of the dispersions can be greatly suppressed, and therefore irregularities in the brightness of emitted light across pixels, of an order such that it causes problems in practical use, can be prevented.

Display device, light emitting device, and electronic equipment

To provide a display device and its driving method free from lack of writing time, which usually accompanies an increase in size of a display device and enhancement in definition. Therefore, there is provided a display device and a driving method in which x (x is a natural number equal to or larger than 4) data lines are placed in each column to simultaneously supply video signals to x pixels through the x data lines. The present invention makes it possible to supply video signals to x pixels simultaneously as opposed to conventional dot sequential driving where a signal is supplied to one pixel at a time. Furthermore, a display device of the present invention and its driving method make it possible to supply video signals to (x&#xd7;n) pixels at once as opposed to conventional linear sequential driving where only n pixels in the first to last (the last column is the n-th column) columns receive signals simultaneously. Thus the present invention can make the speed of writing video signals in pixels x times faster than prior art.

Growing community of inventors

Kanagawa, Japan

Kazutaka Inukai