Abstract: The invention provides an organic EL display device usable for both negative and positive polarity video signals. The organic EL display device of the invention has a polarity switching circuit switching a polarity of a digital video signal. In a case where a display panel is made for a negative polarity video signal, when a negative digital video signal is inputted, this polarity switching circuit lets the negative polarity digital video signal pass therethrough without inverting its polarity. When a positive polarity digital video signal is inputted, this polarity switching circuit inverts a polarity of the positive polarity digital video signal and inverts and switches reference data for a white level and reference data for a black level in order to obtain an accurate inverted image. An output of the polarity switching circuit is converted into an analog video signal through a first D/A converter and outputted to the display panel.

Abstract: The invention provides a display device that achieves optimization of an RGB signal without increasing power consumption required for displaying a test image. A display device of an embodiment of the invention has a display panel displaying an image corresponding to an RGB signal, a signal processing circuit portion including a plurality of signal processing circuits optimizing the RGB signal, an ACL circuit controlling the RGB signal so that the display panel emits light with predetermined electric power or less, and first and second test circuits respectively supplying first and second test image signals corresponding to first and second test images for the optimization to the display panel.

Abstract: In a display device performing multiple gray level display using a sub-field drive method, an operation rate of a scan driver and a data driver is reduced and power consumption in the circuits are reduced. When 28 levels of gray level display is performed with 8 bits of video data, one field is equally divided by 8 into eight sub-fields to generate a first sub-field SF0 through an eighth sub-field SF7. Each of the sub-fields SF0 through SF7 has an equal length of sub-field period to each other. And a line-sequential addressing is adopted in addressing pixels so that each line of video data is written-in collectively. Addressing operation of the pixels and light emitting operation of the pixels are performed in parallel. Each of addressing periods AP0 through AP7 in each of the sub-fields is approximately equal to the sub-field period, that is a period of one field divided by 8.

Abstract: In an organic EL display device, a power loss of a driver transistor is suppressed and heating and power consumption of the display device is reduced. A plurality of R pixels is provided with a first power supply circuit, a plurality of G pixels is provided with a second power supply circuit and a plurality of B pixels is provided with a third power supply circuit. The first power supply circuit generates a voltage PVDD-R and a voltage CV-R. The second power supply circuit generates a voltage PVDD-G and a voltage CV-G. Also the third power supply circuit generates a voltage PVDD-B and a voltage CV-B. Each of the voltages generated by the power supply circuits is independently controlled by a micro processing unit in order for the white balance adjustment.

Abstract: This invention provides a drive system of a display device preventing an uneven display caused by output current values of current conversion circuits. A drive system of a display device of the invention has a plurality of pixels disposed in a matrix of m rows and n columns and having current drive elements, n pieces of current conversion circuits converting digital display signals inputted from outside into analog signals corresponding to the digital display signals, a first selector circuit selectively supplying the digital display signals to the n pieces of the current conversion circuits, and a second selector circuit selectively supplying current outputs of n pieces of the current conversion circuits to pixel groups divided in columns.

Abstract: A disk-like recording medium, such as a compact disc, stores information on tracks recorded on the disc surface. A spindle motor rotates the disc and a read unit, which moves in a radial direction in relation to the disc, reads the stored information off of disc. Servo control of the spindle motor and movement of the read unit is controlled by a control circuit, which acts in response to a recording track detection signal. Servo control of the movement of the read unit is further controlled by a mute circuit, which only allows the read unit to be moved when a control signal generated by the control circuit is above a predetermined voltage level. Limiting when the read unit is driven conserves power.