An electro-optical device having a plurality of pixels including a plurality of EL elements, wherein the electro-optical device provides a gray scale display by controlling a period of time at which the plurality of the EL elements emit light in one frame period; the plurality of the EL elements have a first electrode and a second electrode; the first electrode is held at a constant potential; and a potential of the second electrode changes in such a manner that a polarity of an EL driving voltage, which is a difference between the potentials applied to the first and second electrodes, is inverted for each one frame period.

Electro-optical device

To provide a semiconductor display device capable of displaying an image having clarity and a desired color, even when the speed of deterioration of an EL layer is influenced by its environment. Display pixels and sensor pixels of an EL display each have an EL element, and the sensor pixels each have a diode. The luminance of the EL elements of each in the display pixels is controlled in accordance with the amount of electric current flowing in each of the diodes.

Semiconductor display device

A display device in which variations in luminance due to variations in characteristics of transistors are reduced, and image quality degradation due to variations in resistance values is prevented The invention comprises a transistor whose channel portion is formed of an amorphous semiconductor or an organic semiconductor, a connecting wiring connected to a source electrode or a drain electrode of the transistor, a light emitting element having a laminated structure which includes a pixel electrode, an electro luminescent layer, and a counter electrode, an insulating layer surrounding an end portion of the pixel electrode, and an auxiliary wiring formed in the same layer as a gate electrode of the transistor, a connecting wiring, or the pixel electrode Further, the connecting wiring is connected to the pixel electrode, and the auxiliary wiring is connected to the counter electrode via an opening portion provided in the insulating layer

Display Device and Electronic Apparatus

To improve color reproduction areas in a display device having light-emitting elements. A display region has a plurality of picture elements. Each picture element includes: first and second pixels each including a light-emitting element which has a chromaticity whose x-coordinate in a CIE-XY chromaticity diagram is 0.50 or more; third and fourth pixels each including a light-emitting element which has a chromaticity whose y-coordinate in the diagram is 0.55 or more; and fifth and sixth pixels each including a light-emitting element which has a chromaticity whose x-coordinate and y-coordinate in the diagram are 0.20 or less and 0.25 or less, respectively. The light-emitting elements in the first and second pixels have different emission spectrums from each other; the light-emitting elements in the third and fourth pixels have different emission spectrums from each other; and the light-emitting elements in the fifth and sixth pixels have different emission spectrums from each other.

Display device and electronic device

A circuit (300) and method for controlling the brightness of a display screen (200) implemented using a flat panel field emission display (FED) screen (200). A brightness control circuitry (300) is positioned across the row drivers (220) for altering the applied voltage (212) to the rows (230) causing a change in brightness cross the FED screen (200). The applied voltage (212) can be pulse width modulated or amplitude modulated to alter the brightness of the FED screen (200). Within one FED screen (200) implementation, it is more efficient to alter the row voltage (212); however, in alternative embodiment of the present invention the column voltages (207) are modulated in amplitude or pulse width to alter the brightness of the FED screen (200). The brightness control circuitry (300) of the present invention can be made responsive to a manual brightness knob (520) or can be responsive to an ambient light sensor (580a, 580b).

Circuit and method for controlling the brightness of an fed device

A scanning apparatus for a matrix display panel having a plurality of picture elements at the intersections of X- and Y-line conductors. The scanning apparatus has an X-line driving circuit, Y-line driving circuit, a video signal generator, a timing signal generator, a width control signal generator, a second switching circuit and an analog-to-digital converter. The Y-line driving circuit has a plurality of sets of first memory circuits, a set of second memory circuits, a set of first switching circuits, and a set of brightness control circuits. The scanning apparatus is capable of reproducing moving images having many steps of gray scale from coded video signals having relatively few bits by digital circuits and is also capable of finely controlling the brightness by the efficient use of a horizontal sweep retrace period of the video signals with simplified circuits.

Scanning apparatus for a matrix display panel

A scanning apparatus for an electroluminescent crossed-grid panel having a multiplicity of electroluminescent elements at the intersections of horizontal and vertical electrodes. The scanning apparatus has a horizontal electrode driving circuit adapted to be coupled to said horizontal electrodes and having a set of pulse generators for supplying a selecting pulse to a horizontal electrode to be scanned sequentially in response to a synchronizing signal of a video signal and for supplying the remaining horizontal electrodes at the same time with blanking pulses which are in phase with said selecting pulse and have an amplitude less than one-half of said selecting pulse. A video signal supply means is coupled to said horizontal electrode driving circuit for supplying the synchronizing signal of the video signal. A vertical electrode driving circuit is provided which has a set of brightness control circuits, each of which includes a transistor having the collector thereof adapted to be connected to a corresponding vertical electrode. A circuit for supplying a multi-channel video signal is connected to the base of each said transistor, and a delay means is provided having a delay time corresponding to one horizontal period of the video signal and has taps connected to associated brightness control circuits. A sample reset signal generator is coupled to said brightness control circuits and to said video signal supply means for supplying a sample signal and a reset signal to said brightness control circuits in response to synchronizing signals of a video signal. The video signal supply means is coupled to said vertical electrode driving circuit for supplying an amplified video signal to the input terminal of said delay means. By means of this apparatus each of said electroluminescent elements along the horizontal electrode to be scanned is simultaneously controlled with respect to the brightness thereof by varying the collector resistance of each of said transistors in response to the multi-channel video signals which are sampled at each tap of said delay means at the same time.

Scanning apparatus for electroluminescent crossed-grid panel

1,202,289. Electroluminescence. MATSUSHITA ELECTRIC INDUSTRIAL CO. Ltd. 29 Dec., 1967 [29 Dec., 1966; 30 Dec., 1966], No. 59256/67. Heading C4S. [Also in Divisions H3 and H4] A display apparatus includes electroluminescent crossed grid display panel 15, and horizontal electrode driving circuit 16, including, for instance, pulse generators 101, 102, 103 . . . (see Division H3) coupled to the horizontal electrodes for supplying a selecting pulse of amplitude greater than 200 volts to a selected horizontal electrode and for supplying blanking pulses, in phase with the selecting pulse and of amplitude between one-third and one-half thereof, to the remaining horizontal electrodes in a predetermined sequence. The blanking pulses reduce or obviate cross-talk. Vertical electrode drive circuitry 17 comprises a storage device 36 such as an L.C. delay line for storing video signals from a video signal generator 18, TV camera or signal circuits of a TV receiver for instance, each of the storage device output electrodes being, connected to its respective vertical electrode through a brightness control gate 201, 202, 203 . . . . Each control gate which may comprise two S.C.R.'s (Fig. 3, not shown) or an S.C.R. and resistor combination, is opened simultaneously on application of the selecting pulse to transmit the video signal from storage device 36 to all the vertical electrodes. Counter 33 and sequential pulse circuit 35 can be a counting tube and conventional magnetic core matrix and both may be replaced by a ring counter. Trigger pulse generator 34 may be a monostable vibrator. The electroluminescent material may be ZnS in a binder and a reflective and a non-linear impedance layer such as SiC, CdS or CdSe in a binder may be included. There may be dissimilar numbers of horizontal and vertical conductors and the electrodes are preferably straight, narrow and parallel and preferably the two sets are at right-angles.

Teruo Sato

Papers

Scanning apparatus for a matrix display panel

Scanning apparatus for electroluminescent crossed-grid panel

Electroluminescent image display system having improved horizontal scanning

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