Abstract: The present invention is intended to suppress power consumption of an EL display. In accordance with the brightness of an image to be displayed in a pixel portion, the contrast of the image is determined whether to be inverted or not, and the number of bits of the digital video signal to be input into the pixel portion is reduced, and the magnitude of a current to flow through the EL element is allowed to be maintained at a constant level even when a temperature of an EL layer changes by providing the EL display with another EL element to be used for monitoring a temperature.

Abstract: The data latch circuit of the invention includes a means for short-circuiting an input terminal and an output terminal of an inverter and by connecting the input terminal to one electrode of a capacitor and sampling a data signal or a reference potential to the other electrode of the capacitor, an accurate operation can be obtained without being influenced by variations in the TFT characteristics even when the amplitude of an input signal is small relatively to the width of a power supply voltage.

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: When a time grayscale method is used, it is an object to provide a display device in which the number of signal writings into a pixel can be reduced by dividing one frame period by the number of bits and power consumption can be reduced, and grayscale can be expressed. Further a smaller electronic device that performs display by a time grayscale method can be obtained. Grayscale can be expressed by dividing one frame period into subframe periods without storing signals by grayscale expression by a time grayscale method. Thus, power consumption can be reduced and downsizing of an electronic device can be achieved.

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: A semiconductor display device is formed including an interlayer insulating. Specifically, a TFT is formed and then a nitrogen-containing inorganic insulating film that transmits less moisture compared to organic resin film is formed so as to cover the TFT. Next, organic resin including photosensitive acrylic resin is applied and an opening is formed by partially exposing the organic resin film to light. The organic resin film where the opening is formed, is then covered with a nitrogen-containing inorganic insulating film which transmits less moisture than organic resin film does. Thereafter, the gate insulating film and the two layers of the nitrogen-containing inorganic insulating films are partially etched away in the opening of the organic resin film to expose the active layer of the TFT.

Abstract: The present invention is intended to suppress power consumption of an EL display. In accordance with the brightness of an image to be displayed in a pixel portion, the contrast of the image is determined whether to be inverted or not, and the number of bits of the digital video signal to be input into the pixel portion is reduced, and the magnitude of a current to flow through the EL element is allowed to be maintained at a constant level even when a temperature of an EL layer changes by providing the EL display with another EL element to be used for monitoring a temperature.

Abstract: Amplitude of a data line is made small, thereby reducing power consumption. Included are a first transistor to which a first scan signal is supplied through a first scan line; a second transistor to which a second scan signal is supplied through a second scan line; a third transistor which is turned on or off depending on a first signal supplied from a current supply line through the first transistor and a second signal supplied from a data line through the second transistor; a pixel electrode; and a light-emitting element which emits light by driving current flowing between the pixel electrode and a counter electrode. The first signal cuts electrical connection between the current supply line and the pixel electrode through the third transistor, and the second signal makes the current supply line and the pixel electrode electrically connected through the third transistor.

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: An object of the present invention is to provide a semiconductor device having high operation characteristic and reliability. The measures taken are: A pixel capacitor is formed between an electrode comprising anodic capable material over an organic resin film, an anodic oxide film of the electrode and a pixel electrode above. Since the anodic oxide film is anodically oxidized by applied voltage per unit time at 15 V/min, there is no wrap around on the electrode, and film peeling can be prevented.

Abstract: It is an object of the present invention to provide a display device in which images can be seen under a dark place to intense external light. In the display device, display is performed by changing the gray scale number depending on external light intensity, and display modes can be switched depending on contents displayed on the screen. An analog mode and a digital mode are switched depending on external light intensity. In an analog digital switching circuit, when a video signal is an analog value, a signal is outputted to a pixel array without any change and, when the video signal is a digital value, the signal is outputted to a circuit that performs a digital operation such as a latch circuit. Consequently, display gray scales of a pixel are changed appropriately. Accordingly, a clear image can be displayed. For example, it is possible to ensure visibility in a wide range of a dark place or under indoor florescent light to outdoor sun light.

Abstract: The present invention is characterized in that a transistor with its L/W set to 10 or larger is employed, and that |VDS| of the transistor is set equal to or larger than 1 V and equal to or less than |VGS?Vth|. The transistor is used as a resistor so that the resistance of a light emitting element can be held by the transistor. This slows down an increase in internal resistance of the light emitting element and the resultant current value reduction. Accordingly, a change with time in light emission luminance is reduced and the reliability is improved.

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: If the frequency of a clock signal is increased, the pulse width of a sampling pulse is decreased, and the amount of time for a video signal to be written to a source line is inadequate. Sampling pulses (sam) rise sequentially in synchronization with the rise of a start pulse (SP). As the start pulse (SP) rises, synchronized with the rise of clock signals (CK, CKB), the sampling pulses (sam) fall off sequentially, delayed by half the period of the clock signals (CK, CKB) for every step. As a result, the sampling pulses (sam) with a pulse width longer than one period of the clock signals (CK, CKB) are generated. In a period Ta, a desired video signal (VIDEO) is written to its corresponding source line. In this way, the time for half a period of the clock signal can be secured for writing to the source line.

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: Disclosed is a display device and an electronic apparatus incorporating the display device. The display device includes a transistor and a planarization film over the transistor. The planarization film has an opening where an edge portion is rounded. The display device further includes a first electrode over the planarization film and an organic resin film over the first electrode. The organic resin film also has an opening where an edge portion is rounded. The organic resin film is located in the opening of the planarization film. The first electrode and the transistor are electrically connected to each other through a conductive film. The first electrode is in contact with a top surface of the conductive film. Over the first electrode, a light-emitting member and a second electrode are provided.