Casio Computer Co., Ltd.

Shunji Kashiyama

Jun Ogura

Manabu Takei

Tsuyoshi Ozaki

Ryuichi Hirayama

Naoki Inagaki

Masao Kawamura

Takahiro Fuse

Saburo Kobayashi

Yukinori Hirasawa

Nobol Yabe

A pixel includes a light emitting element and a driving element connected to the light emitting element. After an initial voltage is applied to one end of a current path of the driving element via the signal line, the pixel driving device acquires the threshold voltage of the driving element based on a voltage value at a terminal of the signal line when the initial voltage is cut off and the relaxation time is elapsed. The voltage-current characteristics of the driving element is acquired based on the voltage value at the terminal of the signal line when the current flows into the current path of the driving element via the signal line. The current gain value of the driving element is acquired based on the threshold voltage of the driving element. The image data is corrected based on the acquired threshold voltage.

Pixel driving device, light emitting device and light emitting device driving control method

A data acquisition circuit sets one of the potential value at one end of a signal line and the value of a current flown thereto when one end of a current path of a drive device is connected to a light emitting device with the other end thereof set to a potential value where no current flows to the light emitting device. Then the circuit causes current to flow via the current path and the signal line and acquires one of the value of the current flown to the signal line and the potential value at the one end of the signal line according to the set value. A correction operation circuit acquires a threshold voltage and a current amplification factor of the drive device based on one of the current and potential values thus acquired as well as on one of the potential and current values thus set.

Display driving apparatus, display apparatus and drive control method for display apparatus

A pixel driving device for drive control of pixels, has a image data conversion circuit for generating an original gradation signal by converting an image data, based on a preset conversion property, a signal correction circuit for outputting a corrected gradation signal by adding a correction value acquired based on an electric property parameter of a pixel to the original gradation signal, and a drive signal impressing circuit for impressing a voltage signal corresponding to the corrected gradation signal on one end of a signal line. The original gradation signal has a value that corresponds to a gradation value of the image data and the maximum value of the original gradation signal is set to a value equal to or smaller than a value acquired by subtracting a value corresponding to the correction value from a maximum value in an input range of the drive signal impressing circuit.

Pixel driving device and a light emitting device

A liquid crystal display apparatus to which the present invention is applied has a first data conversion circuit and a second data conversion circuit. The first data conversion circuit converts each predetermined number of display data included in prepared display data into pixel data in which the respective display data are arranged in a predetermined arranging order and in time-series. The second data conversion circuit is provided for each the predetermined number of signal lines included in the display apparatus and sequentially applies display signal voltages corresponding to the pixel data to the predetermined number of signal lines respectively. The liquid crystal display apparatus equalizes the amounts of charges to be written in respective display pixels by reversing the arranging order of the display data in the pixel data and the order of applying the display signal voltages to the signal lines per field period or per horizontal scanning period.

Display drive device and display apparatus having same

A light emitting device has a plurality of pixels, each of which includes a drive transistor, a light emitting element and signal lines, a property parameter acquisition circuit which acquires property parameter, a signal correction circuit that generates a corrected gradation signal by correcting the image data based on the property parameter, and a drive signal impressing circuit that impresses a drive signal, generated based on the corrected gradation signal, on the pixel to drive it. The property parameter is constituted of a threshold voltage, a current amplification factor and its irregularity of the drive transistor, and is acquired based on measured voltages of the signal lines after each of a plurality of predetermined settling times elapses from the time when the light emitting device cuts off a voltage subsequent to impressing the voltage on each pixel for a predetermined length of time.

Light emitting device and a drive control method for driving a light emitting device

A pixel driving device in which, after a reference voltage exceeds a threshold voltage of a drive transistor is impressed through the signal lines on each pixel equipping a light emitting element and the drive transistor, set the signal lines in a state of high impedance, and acquires a voltage value of one end of the signal lines subsequent to a predetermined settling time elapsing, and acquires the threshold voltage of the drive transistor for each pixel and the current amplification factor of the pixel drive circuit as a first property parameter based on acquired voltage values at the time a plurality of first settling times longer than a predetermined value and acquires an irregularity parameter indicating the irregularity in the current amplification factor based on the value of the first property parameter and the measured voltage value acquired at the time shorter than the predetermined value.

Pixel driving device, light emitting device, and property parameter acquisition method in a pixel driving device

A pixel driving device has a voltage impressing circuit that outputs a reference voltage that exceeds a threshold voltage of a drive transistor, a voltage measurement circuit, and a property parameter acquisition circuit that acquires a property parameter related to an electronic property of a pixel. The pixel driving device impresses the reference voltage on the pixel that has a light emitting element and the drive transistor. The voltage measurement circuit acquires voltage of a signal line, as measured voltages, after each of a plurality of the settling times elapsing from the time when the reference voltage is cut. The property parameter acquisition circuit acquires, as property parameters, the threshold voltage and a current amplification factor of drive transistor based on values of a plurality of measured voltages acquired by the voltage measurement circuit.

A portable television reciever of the panel type, having a pocketable size, is provided with about 1/8 the number of scanning electrodes as effective T.V. picture scanning lines, and a panel type picture display device with a double matrix array in which two picture element electrodes lying on each of the signal electrodes commonly provided in the direction of the width of said scanning electrodes are disposed in opposition to each other. A display circuit is driven at a duty cycle expressed as follows: ##EQU1## where A is the number of fields constituting one frame, B is the number of horizontal periods for a video signal assigned to a scanning electrode; and C is the number of scanning lines.

Growing community of inventors

Sagamihara, Japan

Shunji Kashiyama