Abstract: An object of the present invention is to decrease substantial resistance of art 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: Power consumption of a signal processing circuit is reduced. Further, power consumption of a semiconductor device including the signal processing circuit is reduced. The signal processing circuit includes a reference voltage generation circuit, a voltage divider circuit, an operational amplifier, a bias circuit for supplying bias current to the operational amplifier, and first and second holding circuits. The first holding circuit is connected between the reference voltage generation circuit and the bias circuit. The second holding circuit is connected between the voltage divider circuit and a non-inverting input terminal of the operational amplifier. Reference voltage from the reference voltage generation circuit and reference voltage from the voltage divider circuit can be held in the first and second holding circuits, respectively, so that the reference voltage generation circuit can stop operating. Thus, power consumption of the reference voltage generation circuit can be reduced.

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 to 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: Brightness irregularities that develop in a light emitting device due to is persion among pixels in the threshold values of TFTs used for supplying electric current to light emitting devices become obstacles to improved image quality of the light emitting device. As an image signal input to a pixel from a source signal line, a desired electric potential is applied to a gate electrode of a TFT for supplying electric current to an EL device, through a TFT having its gate and drain connected to each other. A voltage equal to the TFT threshold value is produced between the source and the drain of the TFT 105. An electric potential in which the image signal is offset by the amount of the threshold value is therefore applied to the gate electrode of the TFT. Further, TFTs are disposed in close proximity to each other within the pixel, so that dispersions in the TFT characteristics do not easily develop.

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 canceled, 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: Brightness irregularities that develop in a light emitting device due to is persion among pixels in the threshold values of TFTs used for supplying electric current to light emitting devices become obstacles to improved image quality of the light emitting device. As an image signal input to a pixel from a source signal line, a desired electric potential is applied to a gate electrode of a TFT for supplying electric current to an EL device, through a TFT having its gate and drain connected to each other. A voltage equal to the TFT threshold value is produced between the source and the drain of the TFT 105. An electric potential in which the image signal is offset by the amount of the threshold value is therefore applied to the gate electrode of the TFT. Further, TFTs are disposed in close proximity to each other within the pixel, so that dispersions in the TFT characteristics do not easily develop.

Abstract: Brightness irregularities that develop in a light emitting device due to is persion among pixels in the threshold values of TFTs used for supplying electric current to light emitting devices become obstacles to improved image quality of the light emitting device. As an image signal input to a pixel from a source signal line, a desired electric potential is applied to a gate electrode of a TFT for supplying electric current to an EL device, through a TFT having its gate and drain connected to each other. A voltage equal to the TFT threshold value is produced between the source and the drain of the TFT 105. An electric potential in which the image signal is offset by the amount of the threshold value is therefore applied to the gate electrode of the TFT. Further, TFTs are disposed in close proximity to each other within the pixel, so that dispersions in the TFT characteristics do not easily develop.

Abstract: A pulse is inputted to TFTs 101 and 104 so that the TFTs would turn ON and then potential of a node a rises. When the potential of the node ? reaches (VDD?VthN), the node ? became in a floating state. Accordingly, a TFT 105 then turns ON, and potential of an output node rises as a clock signal reaches the level H. On the other hand, potential of a gate electrode of the TFT 105 further rises due to an operation of capacitance 107 as the potential of the output node rises, so that the potential of the output node would be higher than (VDD+VthN). Thus, the potential of the output node rises to VDD without voltage drop caused by a threshold of the TFT 105.

Abstract: Brightness irregularities that develop in a light emitting device due to is persion among pixels in the threshold values of TFTs used for supplying electric current to light emitting devices become obstacles to improved image quality of the light emitting device. As an image signal input to a pixel from a source signal line, a desired electric potential is applied to a gate electrode of a TFT for supplying electric current to an EL device, through a TFT having its gate and drain connected to each other. A voltage equal to the TFT threshold value is produced between the source and the drain of the TFT 105. An electric potential in which the image signal is offset by the amount of the threshold value is therefore applied to the gate electrode of the TFT. Further, TFTs are disposed in close proximity to each other within the pixel, so that dispersions in the TFT characteristics do not easily develop.

Abstract: Brightness irregularities that develop in a light emitting device due to is persion among pixels in the threshold values of TFTs used for supplying electric current to light emitting devices become obstacles to improved image quality of the light emitting device. As an image signal input to a pixel from a source signal line, a desired electric potential is applied to a gate electrode of a TFT for supplying electric current to an EL device, through a TFT having its gate and drain connected to each other. A voltage equal to the TFT threshold value is produced between the source and the drain of the TFT 105. An electric potential in which the image signal is offset by the amount of the threshold value is therefore applied to the gate electrode of the TFT. Further, TFTs are disposed in close proximity to each other within the pixel, so that dispersions in the TFT characteristics do not easily develop.

Abstract: Power consumption of a signal processing circuit is reduced. Further, power consumption of a semiconductor device including the signal processing circuit is reduced. The signal processing circuit includes a reference voltage generation circuit, a voltage divider circuit, an operational amplifier, a bias circuit for supplying bias current to the operational amplifier, and first and second holding circuits. The first holding circuit is connected between the reference voltage generation circuit and the bias circuit. The second holding circuit is connected between the voltage divider circuit and a non-inverting input terminal of the operational amplifier. Reference voltage from the reference voltage generation circuit and reference voltage from the voltage divider circuit can be held in the first and second holding circuits, respectively, so that the reference voltage generation circuit can stop operating. Thus, power consumption of the reference voltage generation circuit can be reduced.

Abstract: A light emitting device that achieves long life, and which is capable of performing high duty drive, by suppressing initial light emitting element deterioration is provided. Reverse bias application to an EL element (109) is performed one row at a time by forming a reverse bias electric power source line (112) and a reverse bias TFT (108). Reverse bias application can therefore be performed in synchronous with operations for write-in of an image signal, light emission, erasure, and the like. Reverse bias application therefore becomes possible while maintaining a duty equivalent to that of a conventional driving method.

Abstract: A pulse is inputted to TFTs 101 and 104 so that the TFTs would turn ON and then potential of a node a rises. When the potential of the node ? reaches (VDD?VthN), the node ? became in a floating state. Accordingly, a TFT 105 then turns ON, and potential of an output node rises as a clock signal reaches the level H. On the other hand, potential of a gate electrode of the TFT 105 further rises due to an operation of capacitance 107 as the potential of the output node rises, so that the potential of the output node would be higher than (VDD+VthN). Thus, the potential of the output node rises to VDD without voltage drop caused by a threshold of the TFT 105.

Abstract: Power consumption of a signal processing circuit is reduced. Further, power consumption of a semiconductor device including the signal processing circuit is reduced. The signal processing circuit includes a reference voltage generation circuit, a voltage divider circuit, an operational amplifier, a bias circuit for supplying bias current to the operational amplifier, and first and second holding circuits. The first holding circuit is connected between the reference voltage generation circuit and the bias circuit. The second holding circuit is connected between the voltage divider circuit and a non-inverting input terminal of the operational amplifier. Reference voltage from the reference voltage generation circuit and reference voltage from the voltage divider circuit can be held in the first and second holding circuits, respectively, so that the reference voltage generation circuit can stop operating. Thus, power consumption of the reference voltage generation circuit can be reduced.

Abstract: An object of the present invention is to decrease substantial resistance of art 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: 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 canceled, 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: A light emitting device that achieves long life, and which is capable of performing high duty drive, by suppressing initial light emitting element deterioration is provided. Reverse bias application to an EL element (109) is performed one row at a time by forming a reverse bias electric power source line (112) and a reverse bias TFT (108). Reverse bias application can therefore be performed in synchronous with operations for write-in of an image signal, light emission, erasure, and the like. Reverse bias application therefore becomes possible while maintaining a duty equivalent to that of a conventional driving method.

Abstract: Brightness irregularities that develop in a light emitting device due to is persion among pixels in the threshold values of TFTs used for supplying electric current to light emitting devices become obstacles to improved image quality of the light emitting device. As an image signal input to a pixel from a source signal line, a desired electric potential is applied to a gate electrode of a TFT for supplying electric current to an EL device, through a TFT having its gate and drain connected to each other. A voltage equal to the TFT threshold value is produced between the source and the drain of the TFT 105. An electric potential in which the image signal is offset by the amount of the threshold value is therefore applied to the gate electrode of the TFT. Further, TFTs are disposed in close proximity to each other within the pixel, so that dispersions in the TFT characteristics do not easily develop.

Abstract: Brightness irregularities that develop in a light emitting device due to is persion among pixels in the threshold values of TFTs used for supplying electric current to light emitting devices become obstacles to improved image quality of the light emitting device. As an image signal input to a pixel from a source signal line, a desired electric potential is applied to a gate electrode of a TFT for supplying electric current to an EL device, through a TFT having its gate and drain connected to each other. A voltage equal to the TFT threshold value is produced between the source and the drain of the TFT 105. An electric potential in which the image signal is offset by the amount of the threshold value is therefore applied to the gate electrode of the TFT. Further, TFTs are disposed in close proximity to each other within the pixel, so that dispersions in the TFT characteristics do not easily develop.

Abstract: A pulse is inputted to TFTs 101 and 104 so that the TFTs would turn ON and then potential of a node ? rises. When the potential of the node ? reaches (VDD?VthN), the node ? became in a floating state. Accordingly, a TFT 105 then turns ON, and potential of an output node rises as a clock signal reaches the level H. On the other hand, potential of a gate electrode of the TFT 105 further rises due to an operation of capacitance 107 as the potential of the output node rises, so that the potential of the output node would be higher than (VDD+VthN). Thus, the potential of the output node rises to VDD without voltage drop caused by a threshold of the TFT 105.