Abstract: A plurality of data lines are provided for pixels arranged in one column. One of the data lines is precharged to a predetermined voltage, and a write current of a voltage corresponding to black data is supplied to a selected pixel via another data line. These data lines are connected to the pixels in different rows in a predetermined sequence. A display device capable of writing a complete black signal without impairing a margin for a write time can be provided.

Abstract: Signal lines for supplying signal currents to respective pixel circuits having light emitting elements are arranged. A signal line driving circuit generates, on a signal line, a signal current corresponding to the image data, by switching bit weighting currents output from bit weighting current source circuits provided for respective bits of the image data, using a switch circuit turned on/off dependent on the corresponding bit. Each current source circuit has a function of correcting the level of the bit weighting current output from itself, based on a reference current of the bit weighting current supplied from a reference current line. Therefore, even when the characteristics of TFTs forming respective current source circuits vary widely, variation in signal currents among the signal lines can be suppressed, and unevenness in emission luminance can be suppressed.

Abstract: A reflective liquid crystal display device is integrated with a liquid crystal display panel (1), detects display surface illuminance by a plurality of light sensors (10) provided in the vicinity of the display surface, and in accordance with the detection result, controls luminous intensity of a front light (lighting means) (19) using a lighting control circuit (22) so that the display surface illuminance becomes a predetermined magnitude. Even if the use environment of the reflective liquid crystal display device changes, or more specifically, intensity of external light shone from outside of the device into the display surface varies, the configuration allows controlling automatically the amount of emission from the front light to automatically maintain an appropriate display luminance and to reduce electric power consumption.

Abstract: A display current of a whole gray scale range according to a display signal of four bits is produced from a sum of output currents of an analog current supply circuit producing a first output current according to lower data bits and two digital current supply circuits operating in accordance with corresponding data bits to execute or stop generation of second and third output currents according to higher data bits. The analog current supply circuit has a calibration function of compensating for output current variations due to transistor characteristics at one point in a control range of the first output current. A display device with light-emitting elements can accurately generate a display current for gray-scale expression without imposing an excessive load on a manufacturing process while suppressing circuit footprint.

Abstract: A current supply circuit includes a bit select circuit selectively providing even-numbered bits or odd-numbered bits of eight bit image data, and supplies a gray-scale current corresponding to the bits provided from the bit select circuit to a pixel. In a one-frame period, a time length for supplying a current corresponding to the even-numbered bits to the light-emitting element is set twice as large as a time length for supplying a current corresponding to the odd-numbered bits. By setting 16 levels of the gray-scale current for four bits, a current-time product of a current passing through the light-emitting element during the one-frame period can be controlled to 256 levels for eight bits. Thereby, an image display device provided at each of the pixels with the light-emitting element can reduce sizes of circuits generating the gray-scale current in accordance with a digital signal.

Abstract: Each of pixels arranged in a matrix is divided into sub pixels. Horizontal scanning lines and vertical scanning lines are arranged corresponding to rows and columns of the sub pixels, so that each sub pixel can be independently on and off. Each pixel includes a sub pixel connection circuit arranged between the sub pixels. A sub pixel connection circuit connects the pixel electrodes of corresponding sub pixels in accordance with a sub pixel connection signal input from a data line in synchronization with activation of vertical scanning line.

Abstract: In a compensation mode executed before a supply mode, a current supply circuit for supplying a data current according to display luminance to a current-driven light emitting device allows a reference current to pass through a drive transistor for supplying the data current to a data line in the supply mode. The voltage of a node connected to the gate of the drive transistor at this time is held by a voltage holding capacitor. In the supply mode, the voltage of the node changes according to a data voltage. The data voltage is set according to the difference between the data current to be supplied and the reference current.

Abstract: In a color liquid crystal display device, two capacitors are connected in parallel between a pixel signal line and an electrode of a liquid cell, or one of the capacitors is connected therebetween, or none of the capacitors are connected therebetween, in order to selectively set a potential of the electrode of the liquid crystal cell in any of four steps. Therefore, gradation display in four steps can be achieved without a digital-to-analog conversion circuit, so that the cost of the device can be reduced.

Abstract: Complementary signal lines are provided for data lines provided corresponding to columns of pixels arranged in a display pixel matrix. In a refresh mode, data of these pixels are read out on the complementary signal lines CL and CR, and differentially amplified by a sense amplifier, and the data differentially amplified is written in the original pixel. A refreshing operation is carried out internally and there is no need for externally providing a refreshing memory for storing data used in refreshing the pixel data. Thus, it is possible to reduce the current consumption for holding data of pixels.