摘要:
A liquid crystal device comprises pixels which are switchable between a white state 5 and a black state 6. Spacers 10 are disposed in gaps between the pixels and are birefringent such that the spacers 10 have the same optical properties as liquid crystal in the black state 6. For example, the spacers 10 may have the same retardation as the liquid crystal layer with an optic axis fixed in the direction of the optic axis of the liquid crystal when in the black state 6.
摘要:
A spatial light modulator of the diffractive type comprises rows and columns of pixels (3, 3'). Row electrodes 4 are connected to a strobe signal generator 27 and column electrodes are connected to a data signal generator 25. The column electrodes comprise a first elongate electrodes 1 which are connected together and to the data signal generator 25. The column electrodes further comprise second elongate electrodes 2 which are connected together, are interdigitated with the first electrodes, and are connected to the data signal generator 25. In each row, apart from the end pixels, each pixel has its first electrodes 1 connected to the second electrodes of the preceding pixel and its second electrodes 2 connected to the first electrodes 1' of the succeeding pixel.
摘要:
An active matrix light modulator, such as a thresholdless antiferroelectric active matrix liquid crystal display, comprises an active matrix of control elements 18 disposed at intersections of data lines 22 and scan lines 20, and an array 10 of pixels which are selectively addressable by data and scan signals applied to the control elements 18 by a data driver 12 and a scan driver 14. Such addressing is controlled so that a voltage is applied to each pixel during a corresponding addressing frame by the application of data and scan signals to an associated one of the control elements 18 in order to select the optical level of the pixel for each frame, and bipolar switching is applied to control the voltage applied to the pixel during successive subframes such that, when one optical level is selected for the frame, a positive voltage is applied to the pixel during one subframe of the frame and a negative voltage of equal magnitude but opposite polarity is applied to the pixel during another subframe of the frame and, when another optical level is selected for the frame, an intermediate voltage (preferably zero voltage) is applied to the pixel during both of the subframes of the frame, so as to provide DC balancing within the frame. The required grey level within each frame is accurately reproduced and is substantially independent of the previous state of the pixel. The use of such modulators to reduce the effects of asymmetrical optical performance and colour-sequential displays are also disclosed.
摘要:
An integrated electro-optical device comprises a pixellated liquid crystal modulation layer (6) superposed over an electronic detection layer (3). Modulator pads (12) for the liquid crystal layer (6) may be formed as electrically conductive combs to achieve optical polarisation. Where the liquid crystal layer provides selective absorption of unpolarised light, and separate polarisers between the liquid crystal and detection layers are therefore unnecessary, the device comprises such a liquid crystal layer (6) superimposed over the electronic detector layer (3). Further, an integrated electro-optical device, optionally of the above type, has a plurality of pixels (A', B') of the liquid crystal layer for each pixel (AB) of the detector array. This allows optical shuttering of the detector pixels by electrically modulating the pixellated liquid crystal layer (6).
摘要:
An active matrix light modulator, such as a thresholdless antiferroelectric active matrix liquid crystal display, comprises an active matrix of control elements 18 disposed at intersections of data lines 22 and scan lines 20, and an array 10 of pixels which are selectively addressable by data and scan signals applied to the control elements 18 by a data driver 12 and a scan driver 14. Such addressing is controlled so that a voltage is applied to each pixel during a corresponding addressing frame by the application of data and scan signals to an associated one of the control elements 18 in order to select the optical level of the pixel for each frame, and bipolar switching is applied to control the voltage applied to the pixel during successive subframes such that, when one optical level is selected for the frame, a positive voltage is applied to the pixel during one subframe of the frame and a negative voltage of equal magnitude but opposite polarity is applied to the pixel during another subframe of the frame and, when another optical level is selected for the frame, an intermediate voltage (preferably zero voltage) is applied to the pixel during both of the subframes of the frame, so as to provide DC balancing within the frame. The required grey level within each frame is accurately reproduced and is substantially independent of the previous state of the pixel. The use of such modulators to reduce the effects of asymmetrical optical performance and colour-sequential displays are also disclosed.
摘要:
A spatial light modulator or display comprises pixels (10 11 to 10 mn ), for instance arranged as an active matrix. Addressing the pixels (10 11 to 10 mn ) is controlled by shift registers (12, 24) which are configurable so as to vary the effective resolution of the display. Each shift register (12, 24) comprises a plurality of stages (13 1 to 13 m , 23 1 to 23 n ) which are controlled to operate normally or as "followers", in which latter mode the stage output follows the output of the preceding stage.
摘要:
An (Al,Ga)As/(Al,Ga,In)P semiconductor layer structure is etched using an SiCl 4 or an SiCl 4 /(He,Ne) plasma. The etching is carried out at 0 to 80°C and at a plasma pressure below 1.33x10 -1 Pa (1 mTorr). The etched surfaces are sufficiently smooth for the etching process to be used in the production of (Al,Ga)As/(Al,Ga,In)P semiconductor lasers.