Abstract: According to a driving method of applying a reverse bias voltage, capacitance occurs due to a stacked structure of a conductor, an insulator and a conductor, or due to a structure of a TFT. This capacitance prevents normal operation. The invention provides a pixel configuration including at least a driving transistor for driving a light emitting element and a switching transistor for controlling the driving transistor, wherein the switching transistor is turned on in the case of applying a forward bias voltage after applying a reverse bias voltage. As a result, it is prevented that the potential changes due to unwanted capacitive coupling.

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 semiconductor display device which can suppress the drive frequency while increasing the number of gray scales.

Abstract: A light emitting device capable of suppressing generation of pseudo-contours by increasing the frame frequency while suppressing the drive frequency of a driver circuit is provided. According to the present invention, gray scales are displayed not only by controlling the emission period of a light emitting element, but also by controlling the luminance of the light emitting element. Specifically, one frame period is divided into a plurality of sub-frame periods each having an equal length, and the luminance of the light emitting element in each sub-frame period is controlled to have different levels. By controlling the total sum of the luminance level of the sub-frame periods that are selected with a video signal, a desired gray scale can be displayed.

Abstract: A semiconductor display device that operates normally at a room temperature may not operate normally at a low temperature. Meanwhile, in semiconductor display devices with the same circuit configuration and the same driving method, the higher the operating frequency is, the better the display quality is. Thus, a semiconductor display device the operating frequency of which is set on the basis of a room temperature may not operate normally at a low temperature. According to the invention, the temperature and the operating state of a semiconductor display device are measured to vary the operating frequency in accordance with the measurement result. More specifically, the operating frequency is decreased at a low temperature to obtain normal operation, while the operating frequency is increased at a room temperature and a high temperature to improve the display quality.

Abstract: It is an object of the present invention to provide a method of manufacturing a display device, which can display images favorably by insulating a short-circuit portion between an anode and a cathode. Further, it is another object of the invention to provide a method of manufacturing a display device, which can prevent intrusion of moisture so as to inhibit deterioration of a light emitting element when the short-circuit portion between the anode and the cathode is insulated. Specifically, the invention provide a method of manufacturing a display device, wherein a reverse bias voltage is applied to the light emitting element including an electro-luminescent material between the anode and the cathode so as to insulate the short-circuit portion between the anode and the cathode at a temperature of from ?40° C. to 8° C., more preferably, from ?25° C. to 8° C.

Abstract: A display device and a driving method thereof are provided, which reduces an instantaneous current generated with a charge and discharge of source signal lines and further reduces a load to a power supply line. According to the invention, source signal lines are divided into the first to the n-th groups so as to be charged or discharged according to the first to the n-th latch pulses which are inputted at different timing. Since the number of the source signal lines which start to be charged or discharged at the same time is reduced, an instantaneous current generated with the charge and discharge can be reduced, and a load to the power supply line can be reduced as well.

Abstract: It is an object of the present invention to provide a light emitting device which can be made into a module with smaller volume. By using a light emitting element represented by an EL element and the like as a pixel portion, two pixel portions are formed at different portions over the light emitting device. A first pixel portion comprises a plurality of pixels arranged in matrix. In the periphery of the first pixel portion, a first source line driving circuit and a first gate line driving circuit for transmitting signals to the first pixel portion are formed. A second pixel portion is formed of passive pixels, and is segregated from a TFT group which constitutes the first pixel portion, the first source line driving circuit, and the first gate line driving circuit in the direction from the back surface of the substrate to the top surface of the substrate by interposing an interlayer film therebetween.

Abstract: A photodetector of the invention is characterized by having a plurality of detector elements that are arranged over a light-transparent substrate and are connected in parallel. A foldable portable communication tool having two display portions of the invention is characterized by including one photodetector which includes a plurality of detector elements connected in parallel.

Abstract: It is provided a display device that prevents, when applying a reverse bias, an anode line and a power supply line included in a signal line driver circuit from being short-circuited, and a driving method thereof. According to the invention, a reverse bias applying circuit is provided in a scan line driver circuit or a signal line driver circuit, a signal from the reverse bias applying circuit is supplied to a transistor disposed between a signal line and an anode line, and thereby the transistor is turned off. The reverse bias applying circuit comprises an analog switch or a clocked inverter and a biasing transistor, and drives so as to invert potentials of the anode line and a cathode. line and apply a reverse bias to a light emitting element, while turn off the analog switch and turn on the biasing transistor. Then, a potential of the anode line becomes equal to that of a scan line, and thereby turning off the transistor between the anode line and the signal line assuredly.

Abstract: A light emitting device is provided, in which a change of luminance of an OLED is suppressed and a desired color display can be stably performed even if an organic light emitting layer is somewhat deteriorated or an environmental temperature is varied. Separately from a pixel portion for displaying an image, a pixel portion for measuring a driving current of the OLED is provided in the light emitting device. The driving current is measured in the pixel portion for measuring the driving current of the OLED, and a value of the voltage supplied to the above two pixel portions from a variable power supply is corrected such that the measured driving current has a reference value. With the above-described structure, a reduction of the luminance accompanied with the deterioration of the organic light emitting layer can be suppressed. As a result, a clear image can be displayed.

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 light emitting device is provided, in which a change of luminance of an OLED is suppressed and a desired color display can be stably performed even if an organic light emitting layer is somewhat deteriorated or an environmental temperature is varied. Separately from a pixel portion for displaying an image, a pixel portion for measuring a driving current of the OLED is provided in the light emitting device. The driving current is measured in the pixel portion for measuring the driving current of the OLED, and a value of the voltage supplied to the above two pixel portions from a variable power supply is corrected such that the measured driving current has a reference value. With the above-described structure, a reduction of the luminance accompanied with the deterioration of the organic light emitting layer can be suppressed. As a result, a clear image can be displayed.

Abstract: [Object] To stabilize a luminance and prevent a degradation during use in a display device of an active matrix driving system that arranges TFTs in matrix, by completely repairing a defective portion through application of a reverse voltage and repairing a short-circuit or leak area of a light emitting device.

Abstract: The present invention is to carry out stable doping and to prevent the drastic pressure change in a treatment chamber by reducing degasification of resist during adding impurities. In the present invention, the stability of the impurity ion injection can be ensured by reducing degasification of resist by reducing the area (resist area proportion, that is, the ratio of the area of resist to the whole area of a substrate) of resist pattern which is used depending on the conditions such as acceleration voltage or current density of a doping process.

Abstract: A manufacturing method of a display device, which prevents electrostatic breakdown of the display device both before and after a circuit test without reducing the productivity in forming a plurality of display devices on a substrate to be processed by a step-and-repeat exposing method. A wiring pattern group led out from signal input terminals of the display devices to the edge of the substrate to be processed is efficiently formed by exposing to light through a repetitive pattern integrated with a display device pattern. Depending on the states of the wiring pattern group as to contact or non-contact with a detachable and conductive component, the signal input terminals of the display devices can be easily switched between in a short circuited state and a non-short circuited state. Accordingly, both the measure against electrostatic breakdown and the circuit test are achieved in the display devices on the substrate to be processed.

Abstract: There are provided a method for deciding a duty factor in driving a light-emitting device and a driving method using the duty factor that enable restraint of deterioration of light-emitting elements and improvement in reliability. In a method for deciding a duty factor of a light-emitting device that performs display based on an analog video signal, with respect to a characteristic obtained by multiplying the characteristic of luminance after X hours in relation to the current density and the characteristic of luminance after X hours in relation to the duty factor when the total quantity of electricity flowing through light-emitting elements in one frame period is defined at a specific value, a range of duty factor that enables realization of luminance approximately exceeding a value that is 0.8 times a maximum value is regarded as an optimum range of duty factor.

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 driving method is provided which improves the duty ratio, which presents high image quality by securing a sufficient length of sustain (lighting) period when gray scales are increased in number, and which prolongs the lifetime of a light emitting element. One frame period has m (m is a natural number equal to or larger than 2) different sub-frame periods SF1, SF2, . . . , and SFm. The m different sub-frame periods SF1, SF2, . . . , and SFm each have an address period and a sustain period. Analog data signals are inputted to their respective light emitting elements in the address period. In the sustain period, the light emitting elements emit light in response to the analog data signals at n (n is a natural number equal to or larger than 2) levels of luminance for gray scale display.

Abstract: A light emitting device is provided, in which a change of luminance of an OLED is suppressed and a desired color display can be stably performed even if an organic light emitting layer is somewhat deteriorated or an environmental temperature is varied. Separately from a pixel portion for displaying an image, a pixel portion for measuring a driving current of the OLED is provided in the light emitting device. The driving current is measured in the pixel portion for measuring the driving current of the OLED, and a value of the voltage supplied to the above two pixel portions from a variable power supply is corrected such that the measured driving current has a reference value. With the above-described structure, a reduction of the luminance accompanied with the deterioration of the organic light emitting layer can be suppressed. As a result, a clear image can be displayed.