Abstract: An active matrix display device comprises an array of display pixels provided over a common substrate. Each pixel has a voltage-programmed current source circuit, a drive transistor and a light sensitive device for sensing the display element light output. The light sensitive device provides a current dependent on the display element output, and the light sensitive device and the current source circuit define a feedback control loop which controls the voltage provided to the gate of the drive transistor. This pixel circuit uses a current source circuit to provide a gate voltage to a drive transistor. This enables the current source circuit to operate at low current levels, and therefore under low voltage stress.

Abstract: A digital to analog converter system comprises an input circuit (3) which converts, during a sequence of corresponding time periods (Ti), a digital input signal (IS) having more than n bit into a sequence of n-bit digital input sub-signals (DS). An n-bit digital to analog converter (1) sequentially converts the digital input sub-signals (DS) into a sequence of analog output sub-signals (VD). A signal storage circuit (2) stores analog output sub-signals of the sequence of analog output sub-signals (VD) to obtain the analog output voltage (VO) as a combination of the sequence of analog sub-output signals (VD).

Abstract: The present invention relates to a display device (100) arranged to operate in two different modes: a transparent mode and a display mode. The idea of the present invention is that a transparent plate (101) is provided with a plurality of light emitting means (102). The light emitting means are arranged in a grid which defines the pixels of the display device. The area of each light emitting means must be small compared to the area (104) of the corresponding pixel it illuminates, since the plate provided with the light emitting means must appear transparent to the human eye. A first switchable diffuser (103) is placed in front of the plate. Thus, the display device will appear virtually transparent when the diffuser is operated in the transparent mode, whereas when operated in the display mode, the light emitted from the light emitting means will be diffused and result in uniform pixels of the display device.

Abstract: The invention provides a method of activating an electronic paint (50). A registration code embedded in a first portion (20) of an image written on a portion of an electronic paint (50) is scanned. A position of an electronic brush (30) is determined based on the scanned registration code, and a second portion (22) of the image is written on the electronic paint (50) based on the determined position of the electronic brush (30).

Abstract: The invention provides a method of activating an electronic paint (50). An electronic-paint registration code on a coded portion (20) of an electronic paint (50) is scanned. A position of an electronic brush (30) relative to the coded portion (20) of the electronic paint (50) is determined based on the scanned electronic-paint registration code, and a predetermined image is written on the electronic paint (50) based on the position of the electronic brush (30).