摘要:
A light-emitting element has a property that a resistance value (internal resistance) changes in accordance with an environmental temperature. It is an object to downsize a monitoring element which corrects an influence of variations in current value of the light-emitting element, which are caused by an environmental temperature change and a change with time. A pixel includes a plurality of sub-pixels, areas of light-emitting elements provided in the individual sub-pixels are made to be different from each other, and an area of a monitoring element is made to be the same as an area of the light-emitting element in any of the sub-pixels, thereby correcting light-emission of the pixel by the monitoring element.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
There is 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.
摘要:
Degradations in light emitting elements occur with the passage of time. A method of driving a light-emitting device is characterized by including the steps of: supplying a light-emitting element with the current in response to an analog video signal during a sustaining period; and turning switch off thereby to make the light-emitting element nonluminous or making first and the second electrodes identical in potential thereby to make the light-emitting element nonluminous during an off time period.
摘要:
A semiconductor device with less power consumption and an electronic appliance using the same. The semiconductor device of the invention is supplied with a first potential from a high potential power source and a second potential from a low potential power source. Upon input of a first signal to an input node, an output node outputs a second signal. With the semiconductor device of the invention, a potential difference of the second signal can be controlled to be smaller than a potential difference between the first potential and the second potential, thereby power consumption required for charging/discharging wires can be reduced.
摘要:
A semiconductor device with less power consumption and an electronic appliance using the same. The semiconductor device of the invention is supplied with a first potential from a high potential power source and a second potential from a low potential power source. Upon input of a first signal to an input node, an output node outputs a second signal. With the semiconductor device of the invention, a potential difference of the second signal can be controlled to be smaller than a potential difference between the first potential and the second potential, thereby power consumption required for charging/discharging wires can be reduced.
摘要:
A method of driving an EL display device in which pseudo contours are difficult to be seen is provided. A method of driving an EL display device in which a plurality of pixels, each having a first TFT, a second TFT, a third TFT, and an organic EL element, are formed has the following: n+m display periods (where n and m are both natural numbers) appear in one frame period; the n+m display periods each correspond to one bit of a digital video signal among n bits of the digital video signal; a plurality of display periods, among the n+m display periods, correspond to the same bit of the digital video signal; and display periods corresponding to other bits of the digital video signal, among the n+m display periods, appear during the plurality of display periods.
摘要:
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.