Abstract: A semiconductor display device using a light-emitting element, which can suppress luminance unevenness among pixels due to the potential drop of a wiring, is provided. Power supply lines to which a power supply potential is supplied are electrically connected to each other in a display region where a plurality of pixels are arranged. Further, an interlayer insulating film is formed over a wiring (an auxiliary power supply line) for electrically connecting the power supply lines to each other in the display region and a gate electrode of a transistor included in a pixel; and the power supply lines are formed over the interlayer insulating film which is formed over the auxiliary power supply line and the gate electrode. Furthermore, a wiring (an auxiliary wiring) formed over the interlayer insulating film is electrically or directly connected to the auxiliary power supply line.

Abstract: There is provided a semiconductor device in which fabrication steps can be reduced by constructing a circuit using only TFTs of one conductivity type and in which a voltage amplitude of an output signal can be normally obtained. A capacitance (205) is provided between a gate and a source of a TFT (203) connected to an output node, and a circuit formed of TFTs (201) and (202) has a function to bring a node ? into a floating state. When the node ? is in the floating state, a potential of the node ? is caused higher than VDD by using gate-source capacitance coupling of the TFT (203) through the capacitance (205), thus an output signal having an amplitude of VDD-GND can be normally obtained without causing amplitude attenuation due to the threshold value of the TFT.

Abstract: In order to increase the continuous operating time of a display device driven by a battery or the like, and a portable information terminal using the same, the volume and weight of the battery are increased. Thus, there arises a trade-off between the increased capacity of the battery and the portability of the device/terminal. Therefore, the invention provides a display device with portability ensured, which is capable of operating continuously for long periods and a portable information terminal using the same. In the display device, TFTs and an RFID tag are formed over the same insulating substrate. The RFID tag detects signals from a reader/writer, and generates DC power based on the signals. While the RFID tag is detecting signals, the display device is driven by the DC power generated in the RFID tag.

Abstract: To provide a structure and a manufacturing method for efficiently forming a transistor to which tensile strain is preferably applied and a transistor to which compressive strain is preferably applied over the same substrate when stress is applied to a semiconductor layer in order to improve mobility of the transistors in a semiconductor device. Plural kinds of transistors which are separated from a single-crystal semiconductor substrate and include single-crystal semiconductor layers bonded to a substrate having an insulating surface with a bonding layer interposed therebetween are provided over the same substrate. One of the transistors uses a single-crystal semiconductor layer as an active layer, to which tensile strain is applied. The other transistors use single-crystal semiconductor layers as active layers, to which compressive strain using part of heat shrink generated by heat treatment of the base substrate after bonding is applied.

Abstract: The present invention provides a semiconductor device in which a power line is not affected by noise due to a voltage drop caused by instantaneous high-current consumption in the buffer portion and that has no possibility that a logic portion malfunctions. In a case where the same potential is supplied to a logic portion and a buffer portion, by a method in which separate FPC terminals are used for the logic portion and the buffer portion, or by a method in which the FPC terminal is shared but a power line is branched for the logic portion and the buffer portion at a point close to the FPC terminal, a problem that the logic portion is affected by noise generated by a voltage drop of the power line due to instantaneous high-current consumption in the buffer portion can be prevented.

Abstract: Display irregularities in light emitting devices, which develop due to dispersions per pixel in the threshold value of TFTs for supplying electric current to light emitting elements, are obstacles to increasing the image quality of the light emitting devices. An electric potential in which the threshold voltage of a TFT (105) is either added to or subtracted from the electric potential of a reset signal line (110) is stored in capacitor means (108). A voltage, in which the corresponding threshold voltage is added to an image signal, is applied to a gate electrode of a TFT (106). TFTs within a pixel are disposed adjacently, and dispersion in the characteristics of the TFTs does not easily develop. The threshold value of the TFT (105) is thus cancelled, even if the threshold values of the TFTs (106) differ per pixel, and a predetermined drain current can be supplied to an EL element (109).

Abstract: An object of the present invention is to decrease substantial resistance of an electrode such as a transparent electrode or a wiring, and furthermore, to provide a display device for which is possible to apply same voltage to light-emitting elements. In the invention, a auxiliary wiring that is formed in one layer in which a conductive film of a semiconductor element such as an electrode, wiring, a signal line, a scanning line, or a power supply line is connected to an electrode typified by a second electrode, and a wiring. It is preferable that the auxiliary wiring is formed into a conductive film to include low resistive material, especially, formed to include lower resistive material than the resistance of an electrode and a wiring that is required to reduce the resistance.

Abstract: The invention provides a display device and an electronic apparatus which can reduce power consumption in the case of being driven by using a digital time grayscale method. According to the invention, a row in which all the pixels display black is focused on in a plurality of pixels arranged in matrix, and sampling of data which is to be inputted to the pixels arranged in the row is not performed. Then, in a period during which the data sampling is not performed, the operation of a shift register in a source driver and sampling operation of a video signal in a first latch circuit are stopped. The invention which has the aforementioned characteristics can temporally stop operation of the source driver to reduce power consumption. In particular, the invention can stop operation of the source driver which consumes much power in the display device, leading to dramatic reduction in power consumption.

Abstract: Display irregularities in light emitting devices, which develop due to dispersions per pixel in the threshold value of TFTs for supplying electric current to light emitting elements, are obstacles to increasing the image quality of the light emitting devices. An electric potential in which the threshold voltage of a TFT (105) is either added to or subtracted from the electric potential of a reset signal line (110) is stored in capacitor means (108). A voltage, in which the corresponding threshold voltage is added to an image signal, is applied to a gate electrode of a TFT (106). TFTs within a pixel are disposed adjacently, and dispersion in the characteristics of the TFTs does not easily develop. The threshold value of the TFT (105) is thus cancelled, even if the threshold values of the TFTs (106) differ per pixel, and a predetermined drain current can be supplied to an EL element (109).

Abstract: To provide a structure and a manufacturing method for efficiently forming a transistor to which tensile strain is preferably applied and a transistor to which compressive strain is preferably applied over the same substrate when stress is applied to a semiconductor layer in order to improve mobility of the transistors in a semiconductor device. Plural kinds of transistors which are separated from a single-crystal semiconductor substrate and include single-crystal semiconductor layers bonded to a substrate having an insulating surface with a bonding layer interposed therebetween are provided over the same substrate. One of the transistors uses a single-crystal semiconductor layer as an active layer, to which tensile strain is applied. The other transistors use single-crystal semiconductor layers as active layers, to which compressive strain using part of heat shrink generated by heat treatment of the base substrate after bonding is applied.

Abstract: There is provided a semiconductor device in which fabrication steps can be reduced by constructing a circuit using only TFTs of one conductivity type and in which a voltage amplitude of an output signal can be normally obtained. A capacitance (205) is provided between a gate and a source of a TFT (203) connected to an output node, and a circuit formed of TFTs (201) and (202) has a function to bring a node ? into a floating state. When the node ? is in the floating state, a potential of the node ? is caused higher than VDD by using gate-source capacitance coupling of the TFT (203) through the capacitance (205), thus an output signal having an amplitude of VDD-GND can be normally obtained without causing amplitude attenuation due to the threshold value of the TFT.

Abstract: In order to increase the continuous operating time of a display device driven by a battery or the like, and a portable information terminal using the same, the volume and weight of the battery are increased. Thus, there arises a trade-off between the increased capacity of the battery and the portability of the device/terminal. Therefore, the invention provides a display device with portability ensured, which is capable of operating continuously for long periods and a portable information terminal using the same. In the display device, TFTs and an RFID tag are formed over the same insulating substrate. The RFID tag detects signals from a reader/writer, and generates DC power based on the signals. While the RFID tag is detecting signals, the display device is driven by the DC power generated in the RFID tag.

Abstract: In a display device with a pixel constituted using an EL element or the like, leak light from a monitoring element that is provided for correcting changes in the properties of the element due to the temperature change, deterioration, or the like is effectively suppressed. The display device has a structure in which an insulating layer is formed over a substrate and a plurality of light emitting elements each of which has a light emitting layer interposed between a first electrode and a second electrode are formed over the insulating layer. Furthermore, at least part of the plurality of light emitting elements has a structure in which an opening is formed in the insulating layer, and the light emitting layer is formed in the opening region of the insulating layer.

Abstract: Power consumption is reduced in a driving circuit of a display device capable of handling a low voltage amplitude input signal by employing level shifters that utilize a differential amplifier. The driving circuit is divided into a plurality of units and each unit is provided with a constant current source. In addition to a usual scanning circuit, there is provided a sub-scanning circuit for controlling ON/OFF of the constant current source arranged in each unit. The sub-scanning circuit turns ON only the constant current sources in the unit that is being scanned. A current thus can be supplied efficiently.

Abstract: The semiconductor device has a semiconductor layer, a gate electrode which covers an end portion of the semiconductor layer, and an insulating layer for insulating the semiconductor layer and the gate electrode. The film thickness of the insulating layer which insulates a region where an end portion of the semiconductor layer and the gate electrode overlap each other is thicker than the film thickness of the insulating layer which covers the central portion of the semiconductor layer.

Abstract: The invention provides a light emitting device which can suppress the reduction of luminance in accordance with the light emission time and light emission at a high luminance. Moreover, the invention relates to a driving method which can suppress the reduction of luminance in accordance with the light emission time and light emission at a high luminance. The light emitting device of the invention can display a plurality of colors of which brightness and chromaticity are different by visually mixing light emission of a plurality of light emitting elements of which light emission colors are different. When a visually mixed display color is formed, a white light emission is exhibited.

Abstract: In a display device with a pixel constituted using an EL element or the like, leak light from a monitoring element that is provided for correcting changes in the properties of the element due to the temperature change, deterioration, or the like is effectively suppressed. The display device has a structure in which an insulating layer is formed over a substrate and a plurality of light emitting elements each of which has a light emitting layer interposed between a first electrode and a second electrode are formed over the insulating layer. Furthermore, at least part of the plurality of light emitting elements has a structure in which an opening is formed in the insulating layer, and the light emitting layer is formed in the opening region of the insulating layer.

Abstract: The semiconductor device has a semiconductor layer, a gate electrode which covers an end portion of the semiconductor layer, and an insulating layer for insulating the semiconductor layer and the gate electrode. The film thickness of the insulating layer which insulates a region where an end portion of the semiconductor layer and the gate electrode overlap each other is thicker than the film thickness of the insulating layer which covers the central portion of the semiconductor layer.

Abstract: The invention provides a light emitting device which can suppress the reduction of luminance in accordance with the light emission time and light emission at a high luminance. Moreover, the invention relates to a driving method which can suppress the reduction of luminance in accordance with the light emission time and light emission at a high luminance. The light emitting device of the invention can display a plurality of colors of which brightness and chromaticity are different by visually mixing light emission of a plurality of light emitting elements of which light emission colors are different. When a visually mixed display color is formed, a white light emission is exhibited.

Abstract: An object is to provide a structure for forming a circuit for which high-speed operation and low-voltage operation are required and a circuit for which sufficient reliability is required at the time of high voltage application in a circuit group provided over one substrate in a semiconductor device, and a manufacturing method thereof. A semiconductor device is provided with a plurality of kinds of transistors which include single-crystal semiconductor layers with different thicknesses, which are separated from a single-crystal semiconductor substrate and bonded, over one substrate. The single-crystal semiconductor layer of a transistor for which high-speed operation is required is formed thinner than that of a transistor for which high resistance to a voltage is required, so that the thickness of the single-crystal semiconductor layer is made to be thin.