Abstract: Semiconductor elements deteriorate or are destroyed due to electrostatic discharge damage. The present invention provides a semiconductor device in which a protecting means is formed in each pixel. The protecting means is provided with one or a plurality of elements selected from the group consisting of resistor elements, capacitor elements, and rectifying elements. Sudden changes in the electric potential of a source electrode or a drain electrode of a transistor due to electric charge that builds up in a pixel electrode is relieved by disposing the protecting means between the pixel electrode of the light-emitting element and the source electrode or the drain electrode of the transistor. Deterioration or destruction of the semiconductor element due to electrostatic discharge damage is thus prevented.

Abstract: A display device with high-definition, in which display unevenness due to a voltage drop in a wiring or display unevenness due to a variation in characteristics of TFTs are suppressed. The display device of the invention comprises a first wiring for transmitting a video signal and a second wiring for supplying a current to a light emitting element. The first wiring and the second wiring extend parallel to each other, and are formed so as to overlap with each other at least partly with an insulating layer interposed therebetween.

Abstract: The invention provides a shift register which can operate normally while suppressing a delay of signal and a rounding of waveform. The shift register of the invention includes a plurality of stages of flip-flop circuits each of which includes a clocked inverter. The clocked inverter includes a first transistor and a second transistor which are connected in series, a first compensation circuit including a third transistor and a fourth transistor which are connected in series, and a second compensation circuit including a fifth transistor and a transmission gate. According to the first compensation circuit, a timing at which a signal outputted from the flip-flop circuit rises or falls can be controlled in synchronization with an output of two stages before. The second compensation circuit can control a clock signal input can be controlled.

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 potential of a gate of a driving transistor is fixed, and the driving transistor is operated in a saturation region, so that a current is supplied thereto anytime. A current control transistor operating in a linear region is disposed serially with the driving transistor, and a video signal for transmitting a signal of emission or non-emission of the pixel is input to a gate of the current control transistor via a switching transistor.

Abstract: The present invention provides a TFT that has a channel length particularly longer than that of an existing one, specifically, several tens to several hundreds times longer than that of the existing one, and thereby allowing turning to an on-state at a gate voltage particularly higher than the existing one and driving, and allowing having a low channel conductance gd. According to the present invention, not only the simple dispersion of on-current but also the normalized dispersion thereof can be reduced, and other than the reduction of the dispersion between the individual TFTs, the dispersion of the OLEDs themselves and the dispersion due to the deterioration of the OLED can be reduced.

Abstract: Semiconductor elements deteriorate or are destroyed due to electrostatic discharge damage. The present invention provides a semiconductor device in which a protecting means is formed in each pixel. The protecting means is provided with one or a plurality of elements selected from the group consisting of resistor elements, capacitor elements, and rectifying elements. Sudden changes in the electric potential of a source electrode or a drain electrode of a transistor due to electric charge that builds up in a pixel electrode is relieved by disposing the protecting means between the pixel electrode of the light-emitting element and the source electrode or the drain electrode of the transistor. Deterioration or destruction of the semiconductor element due to electrostatic discharge damage is thus prevented.

Abstract: Degradations in light emitting elements occur with the passage of time. The invention provides a method of driving a light-emitting device provided with a plurality of pixels, which includes a light-emitting means with a first and a second electrodes, a drive means for supplying the light-emitting means with a current in response to an analog video signal, and a setting means for setting a sustaining period and an off time period within a frame period. The method of driving a light-emitting device is characterized by including the steps of: supplying the light-emitting means with the current in response to the analog video signal during the sustaining period; and turning the drive means off thereby to make the light-emitting means nonluminous or making the first and the second electrodes identical in potential thereby to make the light-emitting means nonluminous during the off time period.

Abstract: A light emitting device comprising a light emitting element and a first transistor and a second transistor controlling current to be supplied to the light emitting element in a pixel; the first transistor is normally-on; the second transistor is normally-off; a channel length of the first transistor is longer than a channel width thereof; a channel length of the second transistor is equal to or shorter than a channel length thereof; gate electrodes of the first transistor and the second transistor are connected to each other; the first transistor and the second transistor have the same polarity; and the light emitting element, the first transistor and the second transistor are all connected in series.

Abstract: To provide a light emitting device without nonuniformity of luminance, a correcting circuit for correcting a video signal supplied to each pixel to a light emitting device. The correcting circuit is stored with data of a dispersion of a characteristic of a driving TFT among pixels and data of a change over time of luminance of a light emitting element. Further, by correcting a video signal inputted to the light emitting device in conformity with a characteristic of the driving TFT of each pixel and a degree of a deterioration of the light emitting element based on the over-described two data, nonuniformity of luminance caused by a deterioration of an electroluminescent layer and nonuniformity of luminance caused by dispersion of a characteristic of the driving TFT are restrained.

Abstract: The invention provides a light emitting device and an element substrate in which a luminance variation of light emitting elements among pixels due to variation in characteristics of driving transistors can be suppressed even without suppressing the off-current of a switching transistor low or increasing the capacitance of a capacitor. A gate of a first transistor is connected to a first scan line, and a gate of a second transistor is connected to a second scan line. A connection between a signal line and a gate of a third transistor is controlled by the first transistor. The second transistor and the third transistor are connected in series between a pixel electrode of a light emitting element and a power supply line. The signal line, the second scan line and the power supply line are disposed in parallel, while the first scan line is crossed with the signal line, the second scan line and the power supply line.

Abstract: A-light-emitting device which realizes a high aperture ratio and in which the quality of image is little affected by the variation in the characteristics of TFTs. The channel length of the driving TFTs is selected to be very larger than the channel width of the driving TFTs to improve current characteristics in the saturated region, and a high VGS is applied to the driving TFTs to obtain a desired drain current. Therefore, the drain currents of the driving TFTs are little affected by the variation in the threshold voltage. In laying out the pixels, further, wiring is arranged under the partitioning wall and the driving TFTs are arranged under the wiring in order to avoid a decrease in the aperture ratio despite of an increase in the size of the driving TFT.

Abstract: A low power consumption shift register which inputs a CK signal with a low voltage with almost no effect of variation in characteristics of transistors. In the invention, an input portion of an inverter is set at a threshold voltage thereof and a CK signal is inputted to the input portion, of the inverter through a capacitor means. In this manner, the CK signal is amplified, which is sent to the shift register. That is, by obtaining the threshold potential of the inverter, the shift register which operates with almost no effect of variation in characteristics of transistors can be provided. A level shifter of the CK signal is generated from an output pulse of the shift register, therefore, the low power consumption shift register having the level shifter which flows a shoot-through current for a short period can be provided.

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 including a substrate, a pixel portion, and a driver circuit having first to ninth transistors and first and second inverters, the various transistors are configured such that one of a source and a drain of the fifth transistor is electrically connected to a gate of the first transistor. In embodiments, the electrical connection may be a direct connection. Additionally, a switch may be provided that is directly connected to an output terminal of the second inverter.

Abstract: 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.

Abstract: A light emitting device and an element substrate which are capable of suppressing variations in the luminance intensity of a light emitting element among pixels due to characteristic variations of a driving transistor without suppressing off-current of a switching transistor low and increasing storage capacity of a capacitor. According to the invention, a depletion mode transistor is used as a driving transistor. The gate of the driving transistor is fixed in its potential or connected to the source or drain thereof to operate in a saturation region with a constant current flow. A current controlling transistor which operates in a linear region is connected in series to the driving transistor, and a video signal for transmitting a light emission or non-emission of a pixel is inputted to the gate of the current controlling transistor through a switching transistor.

Abstract: The invention provides a light emitting device which is capable of displaying on both sides, has a small volume, and is capable of being used as a module. A light emitting element represented by an EL element and the like is used in a pixel portion, and two pixel portions are provided in one light emitting device. A first pixel portion has a structure to emit light only from a counter electrode side of the light emitting element. A second pixel portion has a structure to emit light only from a pixel electrode side of the light emitting element. That is, in the first pixel portion and the second pixel portion, directions of light emission are reverse in front and back.

Abstract: A display device having a first pixel electrode and a second pixel electrode whose areas are different from each other is provided. In the display device, the first pixel electrode and the second pixel electrode are electrically connected to a first transistor and a second transistor, respectively. Gates of the first transistor and the second transistor are electrically connected to each other. A potential is supplied to the first pixel electrode and the second pixel electrode through a wiring electrically connected to the first transistor and the second transistor.

Abstract: The light emitting device has a limiter transistor which is connected to a monitoring element, and an inverter an output terminal of which is connected to a gate electrode of the limiter transistor and an input terminal of which is connected to one electrode of the limiter transistor and the monitoring element. In the case where the monitoring element is short-circuited, the limiter transistor can be turned off by the inverter to correct a defect of the monitoring element.