Tohoku Pioneer Corporation

Naoki Yazawa

Gen Suzuki

Koji Henmi

Masato Togashi

Keisuke Moriya

Takeshi Okuyama

Masatoshi Yamaki

Yoichi Munekata

Shingo Wakou

Daisuke Fujita

The anode sides of respective EL elements E-Econstituting icons are connected to a first potential V, the cathode sides of the EL elements E-Eare connected to current absorption sides of constant current sources I-I, and current output sides of the constant current sources are connected to a second potential Vwhose potential is lower than that of the first potential via light emission control switches S-S. Current regulating resistors R-Rare connected in parallel corresponding to the respective EL elements E-E, and therefore by appropriately selecting the resistance values of the current regulating resistors R-R, light emission intensities of the respective EL elements E-Econstituting icons can be regulated appropriately. During an all extinction period during which the respective EL elements E-Eare all extinguished, an analog switch Sis turned off, and an analog switch Sis turned on. Thus, the anode sides of all EL elements E-Ebecome ground potential, and a reverse bias voltage is applied to all EL elements E-E. By periodic applying of this reverse bias voltage, the light emission lifetimes of the EL elements E-Ecan be prolonged.

Drive device and drive method of light emitting elements

Provided is a driving device that enables compensating for the decrease in luminance characteristic due to the aging of an EL display panel. On a transparent substratemade of, for example, glass, there are lamination-formed a number of luminescent elements. By this, a light from the luminescent element is radiated, via the transparent substrate, in a direction of its intersecting a substrate surface thereof, thereby a display image is formed. The driving device is equipped with photo-electric conversion meansthat, when receiving part of the light from the luminescent elementthat, by using as the interface a substrate surface of the transparent substrateor a substrate surface of a light-guiding substratedisposed on the transparent substratein a laminated state, is reflected within the substrate, produces an electric signal, as well as drive power setting meansthat sets a luminescent drive power that is supplied to each of the luminescent elements. By this construction, it is possible to compensate for the decrease in luminance characteristic due to, for example, the aging of the luminescent element

Device for and method of driving luminescent display panel

In an apparatus for driving a luminescent display panel, in a state in which scanning lines are sequentially scanned to drive and illuminate light-emitting elements, a voltage peak value arising in a scanning line in a non-scanning state is held by a capacitor through parasitic capacitance of the light-emitting element in a non-scanning state. On the basis of the voltage value held by the capacitor, a reverse bias voltage to be output from a reverse bias voltage generation circuit is controlled, and the voltage is supplied to the scanning lines.

Apparatus and method for driving luminescent display panel

In order to realize, at a low cost, the function of an indicator which is brought to a light emitting state during a wait state, a panelas a display section is constituted by self light emitting elements E&#x2013;Enm for example by organic EL elements, and organic EL elements which function as the indicator Ei which is brought to the light emitting state during the wait state are also formed on the same panel. Meanwhile, an indicator drive circuitwhich drives and allows the organic EL elements that function as the indicator Ei to emit light is constructed by one chip IC together with the data driver. By forming the indicator drive circuitas one chip IC in a data driver, the manufacturing cost can be reduced compared to the case where the indicator drive circuit is prepared separately. The EL elements functioning as the indicator Ei also can be formed on the same substrate as that of the respective EL elements E&#x2013;Enm constituting the display section by the same process, thereby contributing to cost reduction.

Self light emitting display device

A transparent electrode layer, an organic EL layer, and a metallic electrode layer are stacked on top of each other in layers on the lower surface of a transparent substrate to form a planar light emitting element region in a light emitting device. A light beam which is emitted from the light emitting element region and incident on the transparent substrate is transmitted out from a display region as well as a light transmitting region formed near an edge of the transparent substrate. Thus, the light emitting device is enabled to facilitate fabrication and make an effective use of the entire surface of the transparent substrate as the light transmitting region.

Light emitting device

An organic EL display includes a transparent electrode, an organic EL layer, and a back electrodesequentially stacked on a transparent substrate. A half mirroris disposed on the outer surface of the transparent substrate. A thin metal film is formed as the half mirrorby vapor-depositing or sputtering one of metals such as Al, Ag, Sn and Cr and a compound such as TiOor several of the metals and compound on the outer surface of the transparent substrate. A transparent resin film on which a thin metal film is formed, or the like is used.

Organic EL display

In a drive method of a light-emitting display panel capable of emitting light in low luminance, the parasitic capacitances of the light-emitting elements disposed in the light-emitting display panel are precharged making use of a reverse bias voltage before they are lit. In this case, a reverse bias voltage created by a reverse bias voltage creation circuit or a peak current being precharged is controlled by selectively grounding control terminals based on dimmer control. In particular, when the light-emitting elements are emitted in low luminance, the reverse bias voltage is output in a low level, thereby the light-emitting elements are prevented from being precharged with an excessive voltage. The above arrangement can realize light emission control in low luminance.

Growing community of inventors

Yonezawa, Japan

Naoki Yazawa