Abstract: A transflective color display having apertures in reflective electrodes through which light from a backlight (9) passes in the transmissive mode. The switching behavior for both the reflective and the transmissive mode is made identical by introducing a retardation plate (11). The transmission efficiency is further increased by using only a monochrome green mode in transmission.

Abstract: The effective image surface area can be increased by insulating, for example by means of an additional layer of an insulating material, electrodes and conductive parts of a black matrix relative to each other at the location of the edge of a patterned top coat of a display device.

Abstract: Nematic liquid crystal display device, in which the isocontrast curve has obtained a more symmetrical shape by combining two and four sub-pixels with twist angles which are smaller than 90 degrees, at which the sub-pixels are obtained by providing different orientation directions (11) in an orienting layer (8) by means of linearly polarized light. If a cholesteric nematic liquid crystal material is used, a sub-pixel may have a twist angle of more than 90 degrees, while pairs of sub-pixels then have twist angles of opposite twist sense, at which the sum of the absolute values of the twist angles is smaller than 180 degrees.

Abstract: The display device comprises a first and a second substrate (52, 53) between which a number of pixels arranged in rows and columns are situated, and said first substrate (52) being provided with a group of electrodes (56, 56', 56") and said second substrate (53) being provided with a group of electrodes (57, 57', 57") for driving the pixels. The display device is characterized in that electrodes of the group of electrodes (56, 56', 56") extend as far as an edge (a) of the first substrate (52), and that the edge (a) of the first substrate (52) and a corresponding edge (a') of a second substrate (53) are positioned relative to each other such that the corresponding edge (a') projects a distance d.sub.1 beyond the edge (b) of the first substrate (52).

Abstract: A circuit arrangement for the square-wave modulated high-frequency voltage operation of a discharge lamp, including means to control the duty cycle of the square wave, has a measuring circuit for detecting the ignition of the discharge lamp during each cycle of the substantially square-wave modulation and a timer circuit coupled to the measuring circuit for rendering the amplitude of the high-frequency voltage substantially equal to zero when a time interval has elapsed after the ignition of the discharge lamp, whereby the luminous flux of the discharge lamp fluctuates to a low degree only.