A method and apparatus for driving a light emitting diode (LED) display having a matrix of LEDs of different colors wherein different color LEDs of the matrix are commonly connected so that a voltage applied to one LED of the commonly connected LEDs is applied to all of the commonly connected LEDs. Different voltages are applied to the commonly connected different color LEDs in the matrix of LEDs. A drive circuit may have commonly connected drivers which multiplex voltages to an array of commonly connected LEDs such that different voltages may be applied to LEDs having different operating voltages. An LED display is also provided.
The disclosure concerns a light display panel with a matrix of pixels each comprising three monochrome electroluminescent diodes of three colors. The diodes are controlled by a control circuit delivering electrical power P to each diode, said electrical power being expressed in the form P-k.Pr, wherein Pr is a reference electrical power particular to the diodes of each color and k is a coefficient selected according to the display to be presented. Over the course of time the reference electrical power is subjected to different variations depending on the colors, to compensate for the aging of the diodes.
A light-emitting device comprising: a first electroluminescent element for emitting light of a first colour when energised; and a second electroluminescent element for emitting light of a second colour when energised, the first electroluminescent element having an active lifetime which is greater than that of the second electroluminescent element; characterised in that the second element is configured to operate at a lower brightness than the first element.
An image display device incorporates a group of pixels of two or more types, each pixel including a light source whose primary wavelength is specific to the type of pixel; a generating device for generating analog pixel signals to be input to the group of pixels from input digital pixel data, wherein the generating device has a converter to convert input digital pixel data into different output digital pixel data appropriate for each type of pixel where the output digital pixel data contains more bits than the input digital pixel data; and an input device for inputting the analog pixel signals to the group of pixels, each pixel including a light emission driver for driving the light source according to the analog pixel signal. An organic EL display device having individual R, G, and B light emission elements enables displaying in desired colors and controllable tones with reduced packaging area for the components of the organic EL display.
An LED display unit disclosed. A plurality of pixels are provided on an insulation substrate. Each pixel comprises vertically arranged green, red, and blue LEDs, wherein the green LED is above the red LED, and the blue LED is below the red LED. Each pixel is positioned in a corresponding one of cavities defined in a predetermined pattern on the insulation substrate, and each cavity provides a light reflection surface on the inner wall.
The present invention provides an electroluminescent display which allows each of Red (R), Green (G), and Blue (B) light-emitting elements to be built up simultaneously for emitting light at predetermined instantaneous luminance in order to improve the reproducibility of gradations when addressed by a pulse-width modulation drive. The electroluminescent display has a charging means for charging at least any one of the R, G, and B light-emitting elements in the duration between the end of a scan and the start of the subsequent scan. The charging means charges different amounts of charge to each of the R, G, and B light-emitting elements. While scanning a scanning line, a power supply is connected to a predetermined drive line in response to the scan on the scanning line, hereby causing a light emission by the light-emitting element connected to the intersection of the scanning line and the drive line.
