Panasonic Liquid Crystal Display Co., Ltd.

Hitachi Displays, Ltd.

Japan Display Inc.

Hitachi, Ltd.

Canon Kabushiki Kaisha

Tohru Kohno

Hajime Akimoto

Naruhiko Kasai

Masato Ishii

Mitsuhide Miyamoto

Hiroshi Kageyama

Akihiro Nakamura

Tomoharu Nakamura

Takahide Kuranaga

Motoo Futami

Hiromu Kakuya

Masaaki Fujimori

Koki Morikawa

In order to provide a calculation method for reproducing solar cell characteristics with high accuracy by using data of a short-circuit current, an open-circuit voltage and the maximum power operation point of a solar cell in a temperature and a solar radiation intensity in a standard state, parameter values for determining characteristics in the standard state are calculated by using data of the short-circuit current, the open-circuit voltage and the maximum power operation point of the solar cell in the temperature and the solar radiation intensity in the standard state. Next, temperature coefficients of the open-circuit voltage and the reverse saturation current are calculated by using the calculated parameters, and a short-circuit current, an open-circuit voltage and the maximum power operation point at a given temperature are calculated.

Method of calculating characteristics of solar cell and solar power generation system

A method for calculating a solar radiation amount is provided, which enables the prediction of a solar radiation amount with consideration also given to the small movement of a cloud that affects a power generation amount generated by a PV array and thereby improves the accuracy of prediction of the power generation amount generated by the PV array. From a measured output value of a solar panel, solar radiation and a temperature parameter are extracted. An output of a PV is calculated from the extracted solar radiation and temperature parameter. The calculated value is correlated with the measured value. A temperature correction coefficient is obtained so that a correlation coefficient is highest, and a solar radiation amount is calculated using the obtained correlation coefficient.

Method for calculating solar radiation amount and method for determining power to be supplied

A low-cost failure diagnosis method, without addition of a measuring unit and a communication unit, provided for a solar battery system, of calculating a working temperature and the number of failed solar battery modules in a solar battery array, by calculating a solar radiation amount while updating a predetermined coefficient as a ratio between a short-circuit current and a working current in accordance with state of the solar battery array and using measured data having the working current and working voltage measured with a detection unit.

Failure diagnosis method for photovoltaic power generation system

In order to provide a system which detects and classifies abnormality in a solar battery even during power generation, an output voltage and an output current of the solar battery during power generation are detected, and a solar battery characteristic equation and a threshold value for detecting an abnormal state are calculated using the detected voltage value and current value and the measurement data of an external environment measurement unit. The kind of abnormal state of the solar battery is classified using the calculation result of the characteristic equation and the threshold value.

Solar power generation system, abnormality detection method, and abnormality detection system

In a case in which a local solution to current-voltage characteristics is generated by way of a partial shade, it has been difficult to perform control for causing a solar cell to operate at a maximum power point efficiently in terms of power and at a low cost. During steady state operation, an MPPT control unitfor performing the normal hill climbing method is selected, and if the change amount of the output current of the solar cell is greater than or equal to a predetermined threshold, an MPPT control unitfor increasing the variation width of the output voltage of the solar cell to greater than the hill climbing method is selected. By way of such control, it is possible to achieve both efficient operation in a steady state and avoidance of a local solution to a partial shade at a low cost.

Solar power system and control system

To provide an image display device having a circuit for solving burning phenomenon without increasing the size of the circuit. An image display device is provided having a display unit formed using display devices, a signal line for inputting a display signal voltage to the display unit, and a display control unit for controlling the display signal voltage, the image display device comprising a detection power source, a switch for causing a current of the detection power source to flow to the display device, a detection circuit for detecting the current, and a detection information storage circuit for storing information, and compensating the display signal voltage, using the information, wherein using a first reference voltage, and current detection is carried out, the detection circuit feeds back the current detected to set a second reference voltage different from the first reference voltage, and carries out current detection.

Image display device

Provided is an image display device, which includes: a display area including a plurality of pixels each of which includes a self light-emitting element; and a plurality of signal lines for inputting an image voltage to each of the plurality of pixels, in which: each of the plurality of pixels includes a field-effect transistor for driving the self light-emitting element based on the image voltage which is input through each of the plurality of signal lines to each of the plurality of pixels; the display area is divided into at least two regions including a first region and a second region; and a (channel width-to-channel length) ratio of the field-effect transistor in the first region is smaller than the ratio of any field-effect transistor in the second region.

Provided is an image display device including: a plurality of pixel scanning lines; a plurality of signal lines; and a plurality of pixel circuits corresponding to intersections between the pixel scanning lines and the signal lines. Each of the pixel circuits includes: a driver transistor; a light emitting element for emitting light based on the current supplied from the driver transistor; a pixel switch for generating a potential based on an image signal and a scanning signal; a capacitor element for controlling the driver transistor based on a potential difference caused by the potential supplied from the pixel switch; and a reset switch for setting a potential at an end of the capacitor element to a predetermined state based on a scanning signal supplied from one of the pixel scanning lines preceding the scanning signal which corresponds to the corresponding one of the plurality of pixel circuits.

Image display device having a reset switch for setting a potential of a capacitor to a predetermined reference state

To determine a deterioration and maintain a high-quality image without unevenness of brightness by performing a precise correction, a detection scanning line for selecting a pixel which detects a deterioration of a pixel, a detection line for informing the outside of the display area of the property of a pixel selected for detecting the deterioration, a deterioration determination means for determining a deterioration amount based on a voltage corresponding to a current detected by the detection line, and a deterioration correction means (computation circuit) for reflecting the determination result of the deterioration determination means in image data supplied to the pixel, are provided.

Imaging device

An organic electroluminescence display device is provided having a display section including a plurality of pixels arranged in a matrix; and a detection section for detecting a luminance characteristic of an OLED element in each of the pixels. The detection section includes a first path for allowing a detected characteristic value to pass therethrough and a second path for attenuating the detected characteristic value. A first switch is provided for the first path whereas a second switch is provided for the second path, the second switch being opened when the first switch is closed. The detected characteristic value having passed through any one of the first path and the second path is input to a same analog-to-digital converter to be converted into a digital quantity.

Organic electroluminescence display device

To shorten the measuring time of the characteristics of light emission of OLED elements for feedback to image data for image display in an organic EL display device. Pixels that emit red lights, pixels that emit green lights, and pixels that emit blue lights are arranged on a screen in a matrix manner. A detection system is provided on the upper side of the screen. A detection line extending from the detection system is coupled to the respective pixels through analog switches and digital switches controlled by switch controlling lines. A detection scanning circuit is provided on the right side of the screen. Detection switch controlling lines extend from the detection scanning circuit. By appropriately selecting the analog switches, the switch controlling lines, and the detection switch controlling lines, the voltage-current characteristics of plural pixels are measured at the same time.

Display device

An image display device includes switches directly connected a constant current source to a self-luminous element to be able to detect a characteristic of the self-luminous element, generate a coordinates and convert information of the characteristic and coordinates into a system communication signal, transferring an input with a temperature variation to a system side.

In a display mode, a signal driving circuit (DAC) transmits image signals to the pixels selected by a scanning circuit for display and first switches of switch units. Then, a power supply circuit supplies a current corresponding to the transmitted signal to the pixels. Then, organic EL elements provided in the pixels are driven to emit light, thereby displaying an image. In order to correct the deterioration of the organic EL elements, first, a constant current flows from a current source to the organic EL elements of the pixels selected by a scanning circuit for detection and second switches and a voltage corresponding to the constant current applied to the organic EL element is detected. The detected voltage is input to an AD converter through a buffer amplifier, and the AD converter converts the voltage into a digital value, and transmits the digital value to a signal correction control unit. When the organic EL element deteriorates, the detected digital value varies. Therefore, the signal correction control unit corrects the signal from the signal driving circuit, thereby correcting the deterioration of the organic EL element.

Imaging device and method of correction pixel deterioration thereof

In an organic EL display, correction is made for a difference in screen luminance between the case of measuring characteristics of OLED elements, and the case of not measuring the characteristics of the OLED elements. A data line for feeding image data items, and a detection line for measuring the characteristics of the OLED elements are connected to respective pixels. Detection of the characteristics of the OLED elements is executed by utilizing a specified period of a frame period. Because an image-displaying period is limited in a frame where measurement of the characteristics of the OLED elementis executed, the luminance undergoes deterioration. In order to prevent the deterioration of the luminance, an analog-to-digital converter ADC causes &#x3b3; characteristic of the OLED elements in the frame where measurement of the characteristics ofis executed to be varied by the agency of a signal from a timing controller Tcon to the analog-to-digital converter ADC, thereby increasing luminance intensity of light emission of the OLED elements.

Organic electroluminescence display

Provided is an image display device in which deterioration of a self-light-emitting element within a pixel is corrected accurately. A detection unit detects, within a detection period, a difference in characteristics between self-light-emitting elements of adjacent pixels. A first subtraction circuit outputs a differential voltage between a reference voltage and an image voltage to a self-light-emitting element that is determined by the detection unit as a deteriorated element. An amplifier amplifies an output of the first subtraction circuit with a gain [1/{1-(&#x3b1;/100)}]when a driver transistor is driven in a saturation region. The amplifier amplifies the output of the first subtraction circuit with a gain [1/{1-(&#x3b1;/100)}] when the driver transistor is driven in a linear region. A differential between the reference voltage and an output of the amplifier obtained by a second subtraction circuit is used as a corrected image voltage.

Growing community of inventors

Kokubunji, Japan

Tohru Kohno