Sanyo Electric Co., Ltd.

Katsuya Anzai

Tsutomu Yamada

Ryoichi Yokoyama

Naoaki Komiya

Shoichi Matsumoto

A source of a driving transistor for driving an organic EL element functions as a first capacitance electrode layer. A second capacitance electrode layer is formed on the source through a gate insulating film of the driving transistor. The second capacitance electrode layer is formed with the same layer and by the same process as the gate electrode. A third capacitance electrode layer is formed extending over the second capacitance electrode layer through the interlayer insulating film. The third capacitance electrode layer is formed with the same layer as the drain electrode and the drain signal line. The third capacitance electrode layer is connected to the source of the driving transistor. The forming area of the storage capacitance element for holding the video signal supplied to the gate of the driving transistor can be thus reduced, improving display quality as well as extending life span of the organic El element.

Display device

A TFT for controlling the power supplied to an element to be driven, such as an organic EL element which operates based on the supplied power, is provided between the element to be driven and a power supply line VL. The TFT and the element to be driven are electrically connected by a wiring layer. The contact position between the wiring layer and the TFT and the contact position between the wiring layer and the element to be driven are positioned so as to be distant from each other. Alternatively, at least the contact hole region of a first electrode of the element is covered by a flattening layer. With this structure, it is possible to realize a flatter surface on which to form, for example, the emissive layer of the element to be driven.

Contact between element to be driven and thin film transistor for supplying power to element to be driven

On a substrate (), one or more inverter circuits for adjusting delay time are provided between an external clock input section (T, T) to which a clock signal CKHor CKHis externally input and a sampling signal generating circuit (shift register). Of the inverter circuits, only necessary inverter circuits are selected and connected, thereby delaying the sampling timing for a video signal. The connection between the inverter circuit and the signal path is achieved simply by changing a connection line pattern mask in accordance with the number of inverter circuits to be connected, and without changing other manufacturing processes.

Video display device

An EL element () having an organic emissive layer or the like between the anode and cathode is used as an element to be driven, and an element driving TFT () for controlling the current supplied to the EL element () and a compensation thin film transistor () having an opposite conductive characteristic as the element driving TFT () are provided between the EL element () and the power supply line VL. With this structure, variation in the current supplied to each EL element () is reduced.

Thin film transistor for supplying power to element to be driven

An active matrix type display device comprising a plurality of pixels arranged in a matrix form, wherein each of the plurality of pixels comprises a display element, a second TFT for supplying power from a driving power supply line to the display element, and a first TFT for controlling the second TFT based on a data signal supplied from a data line when selected, and the driving power supply line extends across the pixel region. More specifically, of opposing first and second sides of a pixel, in a section where the first TFT is connected to the data line, the driving power supply line is placed on the second side, being the side opposite the data line, and in a section where the second TFT is connected to the driving power supply line, the driving power supply line is placed on the first side. In this manner, pixels provided in positions shifted for each row can be connected with a simple wiring layout.

Active matrix type display device

The pixel portion of the display device of this invention has the emissive portion including the organic EL element and the circuit portion including the pixel selection TFT and the driving TFT. The cathode layer C , which is disposed on the emissive portion, is utilized only as the cathode of the organic EL element. The wiring layer made of the same layer as the cathode layer is separated from the cathode layer, and electrically insulated from cathode layer. The wiring layer, which is disposed on the pixel portion, is utilized for other than the cathode. The location to divide the wiring layer from the cathode layer C is above the circuit portion in order to prevent the lowered open aperture. Therefore, it is possible to increase the number of the signal lines and source lines without lowering the open aperture.

One or more element driving TFTs ( ) for controlling the amount of current supplied from a power supply line VL is (are) provided between an organic EL element ( ) and the power supply line VL. The element driving TFT ( ) is placed so that its channel length direction is parallel to the longitudinal direction of the pixel, the extension direction of a data line for supplying a data signal to a switching TFT ( ) for controlling the element driving TFT ( ), or the scan direction of laser annealing for polycrystallizing the active layer ( ) of the TFT ( ).

The number of TFT ( ), thin film transistors for controlling the supplied power to an element to be driven such as an organic EL element ( ) which operates based on the supplied power, provided between the element to be driven and a power supply line VL, is equal to n, where n is an integer greater than or equal to two. The n TFTs ( ) and corresponding element to be driven ( ) are electrically connected by contact points, the number of which is less than or equal to (n&minus;1). It is possible to improve the reliability as a semiconductor device and a display device, and, at the same time, to secure maximum actual operation region (illumination region for an illuminating element) of the element to be driven.

A TFT ( ) for controlling the power supplied to an element to be driven ( ), such as an organic EL element which operates based on the supplied power, is provided between the element to be driven ( ) and a power supply line VL. The TFT ( ) and the element to be driven ( ) are electrically connected to by a wiring layer ( ). The contact position between the wiring layer ( ) and the TFT ( ) and the contact position between the wiring layer ( ) and the element to be driven ( ) are positioned so as to be distant from each other. Alternatively, at least the contact hole region of a first electrode ( ) of the element ( ) is covered by a flattening layer. With this structure, it is possible to realize a flatter surface on which to form, for example, the emissive layer of the element to be driven.

Thin film transistors TFT and TFT for driving elements are formed in parallel between a power source line and an organic EL element, and active layers of the transistors TFT and TFT are spaced apart in a scanning direction of a laser used for annealing for polycrystallization. As a result, the annealing conditions for the transistors TFT and TFT will not be exactly the same, thereby reducing the chance of a same problem being caused in both transistors TFT and TFT

Semiconductor device having thin film transistor for supplying current to driven element

Thin film transistors TFT and TFT for driving elements are formed in parallel between a power source line ( ) and an organic EL element ( ), and active layers ( ) of the transistors TFT and TFT are spaced apart in a scanning direction of a laser used for annealing for polycrystallization. As a result, the annealing conditions for the transistors TFT and TFT will not be exactly the same, thereby reducing the chance of a same problem being caused in both transistors TFT and TFT

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Gifu, Japan

Katsuya Anzai