Abstract: Active matrix liquid crystal displays, mainly applicable to screens with small dimensions, fabricated for example starting from silicon substrates, are especially applicable to display operation in color sequential mode. The pixel comprises a pixel electrode controlled by a control transistor and counter-electrodes situated on the same side of the liquid crystal as the pixel electrode and parallel to the pixel electrode; the liquid crystal is composed of molecules having a natural rest orientation in the absence of a voltage between the pixel electrode and the counter-electrodes and a different orientation in the presence of an electric field created between the pixel electrode and the counter-electrodes. Erase electrodes are situated on either side of the pixel in a transverse direction with respect to the counter-electrodes and are designed to produce, during an erase phase, an erase electric field tending to return the molecules of the liquid crystal to their rest orientation.

Abstract: Method for manufacturing a microelectronic device from a first substrate (10), including the production of at least one electronic component in the semi-conductor substrate after transferring the first substrate (10) onto a second substrate (20), characterized in that it comprises: a first phase carried out prior to the transfer, and including forming at least one pattern made of a sacrificial material in a layer of the first substrate (10), a second phase carried out after the transfer and including the substitution of the electronic component for the pattern.

Abstract: A method for producing an opto-microelectronic micro-imaging device includes a step of forming a first functional part on the base of a first substrate, a base layer, and first electric connection pad. The first functional part is transferred onto a second substrate. The first substrate is thinned until the base layer is reached. A second functional part is formed on the base layer. One via is connected to the first electric connection pad and through the first functional part. The step of forming the second functional part includes connecting the via with the second electric connection pad.

Abstract: A head-up display, including an image source and a mirror positioned along parallel main planes and separated by a first distance, the mirror being shaped to form virtual images of the images provided by the image source at a second distance from the mirror, greater than the first distance.

Abstract: In the field of active matrix liquid crystal displays and, more particularly, to microdisplays produced using collective fabrication technologies, a matrix comprises, for each pixel, a transparent electrode and opaque regions resulting from the presence in the pixel of at least one row conductor, one column conductor, and one control transistor for the pixel connected to the electrode of the pixel. The pixel comprises at least three possible geometrical configurations, the position of the transistor with respect to the rows and to the columns being different in the various configurations, the various configurations being distributed in a pseudo-random manner within at least one region of the matrix.

Abstract: A nanoprojector panel formed of an array of cells, each cell including a liquid crystal layer between upper and lower transparent electrodes, a MOS control transistor being arranged above the upper electrode, each transistor being covered with at least three metallization levels. The transistor of each cell extends in a corner of the cell so that the transistors of an assembly of four adjacent cells are arranged in a central region of the assembly. The upper metallization level extends above the transistors of each the assembly of four adjacent cells. The panel includes, for each assembly of four adjacent cells, a first conductive ring surrounding the transistors, the first ring extending from the lower metallization level to the upper electrode of each cell, with an interposed insulating material.

Abstract: A wavefront analyzer comprises a network of adjustable converging microlenses dividing an incident wavefront into multiple beams and creating a respective focal point for each beam, and a network of light-sensitive detectors placed behind to detect positions of these focal points. The microlenses network is formed from a liquid crystal layer operating in transmission with an array of electrodes forming liquid crystal pixels whose refractive index is controllable by a voltage applied individually to each electrode. Each converging microlens comprises a subset of pixels grouped in a region constituting the microlens, the pixels of a subset having indices that vary radially in a monotonic manner by distance from a central point of the region to its edges, enabling the microlens to operate in refractive mode. The number, position, size and focal length of the microlenses can be adjusted by the profile of the voltages applied to the array of pixels.

Abstract: A photochromic structure includes a plastic support of optical grade with good light transparency, having at least one face with an adhesive layer impregnated with a solution of a solvent with photochromes, having a flexible host matrix for the photochromes, which is mounted by adhesion onto another support. A structure with a uniform flexible photochromic matrix, which has rapid transition times, notably a rapid relaxation time, is thus obtained. The structure is mountable, and advantageously repositionable. It is produced via a process using roll-milling combined with a system for dispensing the solvated solution of photochromes upstream of the rolls, via which a support strip of an adhesive is entrained by the rolls, and the adhesive is gradually impregnated and then laminated on another support.

Abstract: An unpolarized light beam phase modulator emitting in a given wavelength range comprises at least one cell containing a liquid crystal having a helical structure and means for applying a voltage to said cell, said liquid crystal having a torsion elastic constant greater than its twisting elastic constant so as to ensure continuous stable behavior voltage-wise, said liquid crystal having a sufficient number of turns and in which the axis of the turns is in the light-propagation direction, making it possible to obtain an optical effect generated by the liquid crystal on the electrical field that is identical regardless of the direction of this electrical field, said cell being transparent in said wavelength range.

Abstract: A method of display on a color sequential liquid crystal screen, notably an LCOS technology screen (integrated circuit screen), is provided. The liquid crystal between a pixel electrode and counter-electrode common to all pixels, and provision is made to alternate the potential of the counter-electrode at each frame. Writing an image comprises successive addressing of various rows and simultaneous application of a voltage level to column conductors. The writing phase is followed, before the end of a frame, by a phase of switching counter-electrode potential wherein the transistors of the various rows are successively turned on for durations which overlap mutually such that all transistors are simultaneously on at a given moment of this switching phase, and the potential of the counter-electrode is switched at this moment. Overvoltages are thus avoided on the control transistors at the level of the pixel at the moment of the switching of counter-electrode potential.

Abstract: A photochromic structure includes a plastic support of optical grade with good light transparency, having at least one face with an adhesive layer impregnated with a solution of a solvent with photochromes, having a flexible host matrix for the photochromes, which is mounted by adhesion onto another support. A structure with a uniform flexible photochromic matrix, which has rapid transition times, notably a rapid relaxation time, is thus obtained. The structure is mountable, and advantageously repositionable. It is produced via a process using roll-milling combined with a system for dispensing the solvated solution of photochromes upstream of the rolls, via which a support strip of an adhesive is entrained by the rolls, and the adhesive is gradually impregnated and then laminated on another support.

Abstract: To determine the tilt angle in a twisted nematic liquid-crystal cell, the transmission of the cell is calculated as a function of the angle of incidence of a light beam of given wavelength ? using apparent values of the thickness of the cell cavity, of the extraordinary index and of the twist angle, in order to obtain a plurality of simulation curves, one per given pretilt angle, the transmission curve is measured as a function of the angle of incidence of the cell along the axis passing through the top and bottom positions of the cell, for the light beam of wavelength ?, using a contrast meter, and the coincidence between this measurement curve and a curve from among the plurality of simulation curves gives the pretilt angle of this cell.

Abstract: To determine the tilt angle in a twisted nematic liquid-crystal cell, the transmission of the cell is calculated as a function of the angle of incidence of a light beam of given wavelength ? using apparent values of the thickness of the cell cavity, of the extraordinary index and of the twist angle, in order to obtain a plurality of simulation curves, one per given pretilt angle, the transmission curve is measured as a function of the angle of incidence of the cell along the axis passing through the top and bottom positions of the cell, for the light beam of wavelength ?, using a contrast meter, and the coincidence between this measurement curve and a curve from among the plurality of simulation curves gives the pretilt angle of this cell.

Abstract: The disclosure concerns electron tubes. A tube such as a cathode-ray tube consists of several parts, namely the stem, the neck, the cone and the screen of the front face. To build a tube such as this more compactly while, at the same time, improving the quality of the fabrication, a new construction of the neck is proposed. In the prior art, the neck is a glass tube to which there is soldered a glass stem through which pass the connection terminals towards the various electrodes, internal to the tube. Here, the neck is built in the form of a stack of alternating metallic rings and ceramic rings. The metallic rings are used for the supporting of and electrical connection to the internal electrodes. The ceramic rings are used to insulate the metallic rings. The brazings between metallic rings and ceramic rings provide for vacuum tightness. The base of the tube is a ceramic washer without drillings other than lateral ones for the connections to pass through.