Matsushita Electric Industrial Co., Ltd.

Toshiba Matsushita Display Technology Co., Ltd.

Yutaka Nanno

Etsuya Takeda

Seiichi Nagata

Kouji Senda

Hiroshi Tsutsu

Masumi Izuchi

Mika Nakamura

Tetsuya Kawamura

Shin-itsu Takehashi

Takao Kawaguchi

Kazuo Inoue

Yoneharu Takubo

Katsumi Adachi

Naomi Kaneko

Noriko Okawa

An organic EL display panel includes a substrate, pixel electrodes, a common electrode, signal lines, power supply lines, thin-film transistors, scan lines, organic EL elements and storage capacitors. To obtain a full color image by light emissions of the organic EL elements, red, green and blue emitters are patterned correspondently with the pixel electrodes and arranged in this order along the gate line direction. The emitters are patterned such that each pair of the red, green and blue emitters which are adjacent to each other along the gate line direction overlap each other to define a light-emitting layer overlap region, where colors of light components which exit the organic EL elements and pass through the emitters are mixed, between the adjacent organic EL elements arranged along the gate line direction. At least one of the thin-film transistor and the storage capacitor is arranged in the light-emitting layer overlap region.

Organic EL display panel

An EL display deviceincludes a display portionhaving unit pixelsarranged in a matrix, a source line driver circuit, and a gate line driver circuit. Each of the unit pixelshas an EL element, a switching transistor Tr, a driver transistor Tr, and an auxiliary capacitor. The auxiliary capacitorhas electrodes, one connected to a gate electrode of the transistor Trand the other to a next gate line GL. The gate line driver circuitoutputs, via the next gate line GL, blanking signals for forcibly stopping a light-emitting state of the EL elements, within hold times in which the voltages written to the gate electrodes of the transistors Trare held. With such a configuration, a blanking period where the EL elements do not emit light, is inserted in one frame.

EL display device providing means for delivery of blanking signals to pixel elements

An active matrix liquid crystal display device has a plurality of unit pixels being arranged in a matrix configuration, each unit pixel being divided into a plurality of subpixels. Each of the subpixels has a subpixel electrode, a pixel transistor connected to the subpixel electrode, and a voltage controlling capacitor connected to the subpixel electrode. A voltage controlling capacitor line for supplying a compensation voltage signal is connected to the voltage controlling capacitor so that after the writing to the subpixel has been completed, the potential of the compensation voltage signal is varied to modulate the potential of the subpixel electrode to be a predetermined voltage, using the voltage controlling capacitor. Such combining of spatial dithering attained by a pixel-dividing technique and a capacitively-coupled driving method eliminates the need for digital-to-analog converter circuits, attains gray scale display based on a digital image signal, and achieves a reduction in power consumption.

Liquid crystal display device, electroluminescent display device, method of driving the devices, and method of evaluating subpixel arrangement patterns

A unit pixel () includes a plurality of current controlling elements (Tr&#x2013;Tr) having controlling terminal and connected to a single EL element (), and switching elements (Tr&#x2013;Tr) provided to the respective current controlling elements in order to switch between application and cutoff of a digital image signal with respect to the controlling terminals in accordance with the condition of a scanning signal. Each of the current controlling elements is controlled by a voltage of the digital image signal so as to take an OFF state for cutting off a supply of a driving current to the EL element or an ON state for supplying the EL element with a driving current corresponding to the voltage of the digital image signal, and a value of the current flowing in the EL element is the sum value of currents supplied from the respective current controlling elements in the ON state. Based on a combination of the current controlling elements in the ON state, the current supplied to the EL element is controlled to be a value corresponding to the gradation.

Active matrix EL display device and method of driving the same

The present invention provides a liquid crystal display device having a liquid crystal display portion, a gate driver circuit, a source driver circuit, and a power supply circuit, where the liquid crystal display portion includes unit pixels with pixel switching elements and pixel electrodes arranged in a matrix. The pixel switching elements are thin film transistors that are made of polycrystalline silicon semiconductor formed on an insulating substrate. The power supply circuit is a charge pump-type power supply circuit, is made of a polycrystalline silicon semiconductor, and is a built-in circuit integrally formed on an insulating substrate. With such a configuration, a liquid crystal display device that greatly reduces power consumption is realized.

Display device

An object of the present invention is, by eliminating a driver IC from the components of an liquid crystal display, to achieve a cost reduction, to eliminate a manufacturing step of mounting the driver IC onto an array substrate, and to reduce a thickness of the liquid crystal display. A driver circuit for an active matrix liquid crystal display comprises a resistive dividing type digital-to-analog converter circuit (DAC). An analog output voltage from the DAC is amplified by a signal amplifier element, and a liquid crystal element is driven by the amplified analog output voltage. The driver circuit is characterized in that a resistance element R is formed in an n&plus; layer of p-Si on an array substrate of the liquid crystal display, and a switching element Tr and a signal amplifier element are also formed on the array substrate.

Drive circuit for active matrix liquid crystal display

An active matrix liquid crystal display for projection system comprises a light shielding layer 12 arranged between a layer 13 including thin film transistors and a first substrate 11 for shielding an injection light toward each of the thin transistors, said light shielding layer 12 having a plurality of openings through which each of the pixel electrodes 22 is exposed against the injection light. The light shielding layer 12 is preferably made of metal and is connected to an electric source. A level of voltage applied on the data lines is adverse to that applied on the light shielding layer with respect to polarity of the applied voltage.

Active matrix liquid crystal display for projection system

A driving method of an active matrix LCD is provided. According to this method, a scan signal has three voltage levels, i.e., an ON voltage Vg, an OFF voltage Voff and a compensation voltage Ve having the opposite polarity with respect to the OFF voltage Voff. In contrast with the conventional capacitively coupled driving method in which the scan signal consists of four voltages, the driving method of this invention can reduce a cost and power consumption for a driver IC without degradation due to flickers or other causes. The method for adjusting the brightness of the LCD accompanying this driving method as well as the method for optimizing design parameters of the compensation voltage Ve and a thin film transistor of the LCD are also described.

Method for driving active matrix LCD using only three voltage levels

A method of driving a display device having a matrix of display material elements includes transmitting a picture signal voltage to each picture element electrode during an ON period of a respective switching element, applying a first modulation signal to a first wire during an OFF period of the switching elements associated with the first wire, and applying a second modulation signal to counter electrodes associated with the first wire during the OFF period of the switching elements associated with the first wire. Each picture element electrode of a plurality of the display material elements is connected to the first wire through a respective capacitance.

Method of driving an image display device by driving display materials

A method of driving a display unit having matrix-arranged pixel electrodes each connected via a capacitor to a first line, each pixel electrode being connected to a switching element which is electrically connected to an image signal line and scan signal line, and display material held between the pixel electrode and opposing electrode and being AC driven, wherein an image signal voltage is transmitted to the pixel electrode during an on-period of the switching element, and a modulating signal with its voltage reversing alternately for each field is applied to the first line during an off-period of the switching element, thereby changing the potential of the pixel electrode so that the changed potential is superposed upon, or cancelled out from, the image signal voltage, the resultant voltage being applied across the display material.

Method of driving display unit

An electrostatic breakdown protection circuit protects an internal circuit from positive and negative high voltages. One form of the protection circuit includes a hot line connected to the internal circuit for supplying a data signal, a bypass line, a first diode connected in a first direction between the hot line and the bypass line, and a second diode connected in a second direction between the hot line and the bypass line in parallel to the first diode.

Electrostatic breakdown protection circuit

A driving method of a display apparatus for AC driving display materials such as liquid display and so on to the picture display by the use of an active matrix with switching elements of thin film transistors so that the output signal voltage of the signal driving circuit of the active matrix display apparatus is considerably reduced and the consumption power of the same driving circuit handling the analog signal may be reduced.

Capacitively coupled driving method for TFT-LCD to compensate for

In an electro-optical effect display apparatus, a number of pairs of two parallel and closely disposed scanning bus-lines (21-21, 21-21, . . . ) are disposed on a substrate with a predetermined interval therebetween, and a first electrode bus-line (25) is disposed between each other neighboring two pairs of the scanning bus-lines (21-21 and 21-21). Then respective storage capacitors (26) belonging to two display elements (24, 24), each other neighboring with respect to the first electrode bus-line (25), are connected commonly to the first electrode bus-line (25), thereby utilizing a single first electrode bus-line (25) commonly for two storage capacitors (26, 26) which are disposed substantially symmetrically to the first electrode bus-line (25); and thus, the number of bus-lines can be reduced, and consequently, the area of the display element increases.

Display apparatus

A method of production of active matrix display substrates using thin film transistors and more particularly to a method for production of substrates for liquid-crystal display use. The active matrix substrate using the thin film transistor is produced by the mask processes of smaller number. The process of the present invention can reduce the number of the masks, by one, of the active matrix substrate using the inverted staggered thin film transistor which requires the masks from five levels to six levels. Further improvements reduce the number of the masks to four levels from three levels, thus contributing greatly towards lower cost, improved yield.

Growing community of inventors

Takarazuka, Japan

Yutaka Nanno