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 display device where the influence of variations in current of the light emitting element due to changes in ambient temperature and changes with time can be suppressed. The display device of the invention has a light emitting element, a driving transistor connected in series to the light emitting element, a monitoring light emitting element, a limiter transistor connected in series to the monitoring light emitting element, a constant current source for supplying a constant current to the monitoring light emitting element, and a circuit for outputting a potential equal to an inputted potential. A first electrode of the light emitting element is connected to an output terminal of the circuit through the driving transistor, and a first electrode of the monitoring light emitting element is connected to an input terminal of the circuit through the limiter transistor.

Abstract: The invention provides a semiconductor display device with less generation of a pseudo contour while the drive frequency of a driver circuit is suppressed. Furthermore, the invention provides a semiconductor display device with less generation of a pseudo contour while the decrease in image quality is suppressed. A semiconductor display device comprises a table storing data for determining a relationship between the gray scale level of a video signal and a subframe period for light emission in the plurality of subframe periods, a controller for changing a video signal in accordance with the data and outputting, and a panel whose pixel gray scale level is controlled in accordance with the outputted video signal. The number and the length of the plural subframe periods for each gray scale level of 2 or more are determined in accordance with a subframe ratio RSF which is calculated in accordance with a sharing ratio Rsh determined by the frame frequency.

Abstract: A display device, where the power consumption of a display panel can be reduced by controlling a display time rate, including an average gray scale calculator obtaining an average gray scale by averaging a gray scale of each pixel over an entire screen of one frame and for outputting an average gray scale signal, a display time rate table outputting a magnification signal for reducing the display time rate when the average gray scale exceeds a certain value in accordance with the average gray scale signal, and a timing signal generator generating an erase start signal for erasing the digital video signal written to the each pixel in accordance with the magnification signal.

Abstract: A conventional setting voltage was a value with an estimated margin of a characteristic change of a light emitting element. Therefore, a voltage between the source and drain of a driver transistor Vds had to be set high (Vds?Vgs?VTh+a). This caused high heat generation and power consumption because a voltage applied to the light emitting element. The invention is characterized by feedbacking a change in a current value in accordance with the deterioration of a light emitting element and a power source voltage controller which modifies a setting voltage. Namely, according to the invention, the setting voltage is to be set in the vicinity of the boundary (critical part) between a saturation region and a linear region, and a voltage margin for the deterioration is not required particularly for an initial setting voltage.

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 method of electrically inspecting semiconductors display device, which is capable of inspecting whether a signal is normally input to the pixels and whether an electric charge is normally held by the holding capacitors without using the video signal line as a passage for reading the electric charge and without separately providing an inspection-dedicated circuit. Power source lines which are used as passages for supplying the power source voltage are used as passages for reading the electric charge. Namely, the power source lines that can be connected to the signal lines are used as passages for inputting an inspection signal to the holding capacitors in the pixels and for reading the electric charge from the holding capacitors in the pixels.

Abstract: A method of electrically inspecting semiconductor display devices, which is capable of inspecting whether a signal is normally input to the pixels and whether an electric charge is normally held by the holding capacitors without using the video signal line as a passage for reading the electric charge and without separately providing an inspection-dedicated circuit. Power source lines which are used as passages for supplying the power source voltage are used as passages for reading the electric charge. Namely, the power source lines that can be connected to the signal lines are used as passages for inputting an inspection signal to the holding capacitors in the pixels and for reading the electric charge from the holding capacitors in the pixels.

Abstract: By operating a driving TFT in a saturation region, luminance is not easily reduced when an EL element is degraded. However, such problems occur as a high voltage, high power consumption, and heat generation. In the case of operating a driving TFT in a saturation region, luminance varies due to a variation of driving TFTs. In view of the aforementioned problems, a high current capacity TFT is used in the high gray-scale and a low current capacity TFT is used in the low gray-scale. The high current capacity TFT can supply a large current with a lower Vgs, therefore, it does not easily operate in a linear region even when Vds is lowered. Thus, a luminance is not reduced easily even when an EL element is degraded, and an operation at a low voltage is realized. The low current capacity TFT supplies current when high Vgs is applied. With high Vgs, an effect of variation in characteristics of TFTs, especially in Vth can be ameliorated.

Abstract: It is an object of the present invention to provide a display device that is able to display a three-dimensional image without reducing resolution in displaying a two-dimensional image to half, and prevent the device itself from being bulky. This display device is a display device that has a light-emitting device having a plurality of pixels and an optical system at one side of the light-emitting device, where the light-emitting element has two electrodes that both have translucency, light is shielded by the first shield means and light is shielded by the second shield means, and the optical system makes light emitted from one of two adjacent pixels of the plurality of pixels incident into a let eye of a viewer and makes light emitted from the other incident into a right eye of the viewer by controlling a traveling direction of light emitted from the plurality of pixels.

Abstract: The inventors found out that in the case of performing a low gray scale display in which a very small amount of current is supplied to a light emitting element, variations in threshold voltages of driving transistors become notable since the gate-source voltage is low. In view of this, the invention provides a display device in which variations in the threshold voltages of the driving transistors are reduced even in the low gray scale display, and a driving method thereof. According to the invention, a gate-source voltage of the driving transistor is set higher in the low gray scale display than that in the high gray scale display. As one mode to achieve this, different power source lines are provided for the low gray scale display and the high gray scale display and their potentials are set to be different.

Abstract: The reliability of an EL element is enhanced while the increase of the electric power consumption is suppressed. It becomes possible that in a SES drive, the reverse bias is applied to the EL element driven at a constant electric current. Moreover, the application of the reverse bias is performed by varying only the counter electrode, and thus withstand voltage of TFT and the increase of the electric power consumption due to the increase of voltage of the gate signal line drive circuit, which becomes a problem when changing greatly the electric current supplying line, can be suppressed. Furthermore, the reduction of the electric power consumption can also be achieved while the enhancement of the reliability is secured by making the reverse bias smaller than the forward bias.

Abstract: The luminance of light emitting elements varies when the characteristics thereof change due to changes in environment temperature and changes with time. It is an object of the present invention to suppress the effect of the change in current value of a light emitting element due to the changes of environment temperature and changes with time. The invention provides a display device provided with a compensation function for the changes in environment temperature and a compensation function for the change with time. The display device of the invention includes a light emitting element, a driving transistor connected to the light emitting element, and a monitoring light emitting element. By using this monitoring light emitting element, an effect of the change of current value of the light emitting element due to the change of environment temperature and change with time can be suppressed.

Abstract: A latch circuit is disposed to an output terminal of the respective stages of a shift register circuit, when a pulse is shifted to a stage to which an output is wanted to be outputted, a latch pulse is inputted and held there until a subsequent pulse is inputted, when the pulse is shifted to a stage to which an output is wanted to be outputted in the next time, a latch pulse is again inputted, and thereby an output stage is switched. Thus, a period to be selected and a stage to be selected can be arbitrary selected by changing a latch pulse without changing a clock frequency.

Abstract: The reliability of an EL element is enhanced while the increase of the electric power consumption is suppressed. It becomes possible that in a SES drive, the reverse bias is applied to the EL element driven at a constant electric current. Moreover, the application of the reverse bias is performed by varying only the counter electrode, and thus withstand voltage of TFT and the increase of the electric power consumption due to the increase of voltage of the gate signal line drive circuit, which becomes a problem when changing greatly the electric current supplying line, can be suppressed. Furthermore, the reduction of the electric power consumption can also be achieved while the enhancement of the reliability is secured by making the reverse bias smaller than the forward bias.

Abstract: The inventors found out that in the case of performing a low gray scale display in which a very small amount of current is supplied to a light emitting element, variations in threshold voltages of driving transistors become notable since the gate-source voltage is low. In view of this, the invention provides a display device in which variations in the threshold voltages of the driving transistors are reduced even in the low gray scale display, and a driving method thereof. According to the invention, a gate-source voltage of the driving transistor is set higher in the low gray scale display than that in the high gray scale display. As one mode to achieve this, different power source lines are provided for the low gray scale display and the high gray scale display and their potentials are set to be different.

Abstract: The luminance of light emitting elements varies when the characteristics thereof change due to changes in environment temperature and changes with time. It is an object of the present invention to suppress the effect of the change in current value of a light emitting element due to the changes of environment temperature and changes with time. The invention provides a display device provided with a compensation function for the changes in environment temperature and a compensation function for the change with time. The display device of the invention includes a light emitting element, a driving transistor connected to the light emitting element, and a monitoring light emitting element. By using this monitoring light emitting element, an effect of the change of current value of the light emitting element due to the change of environment temperature and change with time can be suppressed.

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 conventional setting voltage was a value with an estimated margin of a characteristic change of a light emitting element. Therefore, a voltage between the source and drain of a driver transistor Vds had to be set high (Vds?Vgs?VTh+a). This caused high heat generation and power consumption because a voltage applied to the light emitting element. The invention is characterized by feedbacking a change in a current value in accordance with the deterioration of a light emitting element and a power source voltage controller which modifies a setting voltage. Namely, according to the invention, the setting voltage is to be set in the vicinity of the boundary (critical part) between a saturation region and a linear region, and a voltage margin for the deterioration is not required particularly for an initial setting voltage.

Abstract: A method of electrically inspecting semiconductor display devices, which is capable of inspecting whether a signal is normally input to the pixels and whether an electric charge is normally held by the holding capacitors without using the video signal line as a passage for reading the electric charge and without separately providing an inspection-dedicated circuit. Power source lines which are used as passages for supplying the power source voltage are used as passages for reading the electric charge. Namely, the power source lines that can be connected to the signal lines are used as passages for inputting an inspection signal to the holding capacitors in the pixels and for reading the electric charge from the holding capacitors in the pixels.