Abstract: The display unit (2) equips a portable instrument, such as a wristwatch (1) with hands (13, 14, 15) for indicating the time. The unit comprises at least one display cell (4) which comprises a transparent front substrate (41) having first transparent electrodes (45) on an interior face, a transparent rear substrate (42) having at least one transparent second electrode (46) on an interior face and a fixing frame (43) for the two substrates in order to define a closed space between the substrates. A substance (44), the optical or physical properties of which can be modified between the electrodes which are activated by a difference of potentials applied via control means, occupies the closed space between the first and second electrodes. Via the action of the control means, the display cell (4) makes it possible to display information, for example temporal information.

Abstract: The display unit (2) equips a portable instrument, such as a wristwatch (1) with hands (13, 14, 15) for indicating the time. The unit comprises at least one display cell (4) which comprises a transparent front substrate (41) having first transparent electrodes (45) on an interior face, a transparent rear substrate (42) having at least one transparent second electrode (46) on an interior face and a fixing frame (43) for the two substrates in order to define a closed space between the substrates. A substance (44), the optical or physical properties of which can be modified between the electrodes which are activated by a difference of potentials applied via control means, occupies the closed space between the first and second electrodes. Via the action of the control means, the display cell (4) makes it possible to display information, for example temporal information.

Abstract: A second device (24) is mounted on a first device (22) formed of a liquid crystal (27) display cell (26) at the front of which is arranged a first linear polarizer (40), of a liquid crystal (29) optical valve (28) at the back of which is arranged a second polarizer (44) and means (23) for controlling the valve (28) and the cell (26) from a switched state to a non switched state. When the cell (26) is switched to display a data item, by associating a first light or dark device (22) with a second absorbent or reflective polarizer (44), an inversion of the contrast in said data is obtained by switching the valve (28).

Abstract: A display assembly is disclosed including an electro-optical cell (28), for example a liquid crystal cell, and a photovoltaic cell (61) acting as a back reflector. In order to improve the aesthetic appearance of the display, the photovoltaic cell (61) reflects predetermined wavelengths and thus exhibits a desired color in the transparent zones (90) of the electro-optical cell. In particular, the reflected light can be colored by reflection onto a multi-layered reflective filter including a transparent electrode (69) of the photovoltaic cell. This cell may form part of the dial of a watch.

Abstract: The invention concerns a display assembly including two superposed, respectively upper (24) and lower (26) display devices, characterised in that the upper display device (24) includes a double structure formed of a display cell (28) arranged above an optical valve (30), said double structure being arranged so that said cell (28) and said valve (30) are transparent in a first state to make the lower display device visible (26), and that the cell (28) displays an item of data and that the valve (30) is opaque and masks at least partially the lower display device (26) in a second state, control means being provided for supplying a control voltage to the cell (28) and the optical valve (30) to cause them to switch from the first state to the second state and vice versa.

Abstract: The assembly includes on the one hand a first device I determining a first color, said device being formed of a liquid crystal display module (CL; CL1, CL2), including at the front and at the back a linear polarizer (PAb1, PAb2) selective of said first color, and on the other hand a second device II including a colored filter (Fy) corresponding to the second color. The assembly is characterised in that the axes of polarization of the selective polarizers (PAb1, PAb2) are parallel to each other, in that the colored filter (Fy) includes at the front a reflective polarizer (PR1) whose axis of polarization is parallel to the axes of polarization of the two polarizers (PAb1, PAb2), and at the back a reflective element (R, PR2), and in that a control unit (7) enables a switching configuration to be defined displaying an item of information in the first color on a background corresponding to the second color or vice versa.

Abstract: The present invention concerns a display assembly including two superposed, respectively top (52) and bottom (54), display devices, the top display device (52) including a double structure formed of a display cell (56) arranged above an optical valve (58), said double structure being arranged so that said cell (56) and said valve (58) are transparent in a first state to make the bottom display device (54) visible, and so that the cell (56) displays an item of data and so that the valve (58) is opaque and at least partially masks the bottom display device (54) in a second state, control means supplying a control voltage to cause the display cell (56) and the optical valve (58) to pass from the first state to the second state and vice versa, characterised in that the display cell (56) is of the reflective type in the switched state, and in that the optical valve (58) is formed of a cell having an absorbent state in the switched state.

Abstract: A display assembly includes two superposed, respectively upper (24) and lower (26) display devices, characterized in that the upper display device (24) includes a display cell (28) arranged above an optical valve (30), said double structure being arranged so as to be transparent in a first state to make the lower display device visible (26), and so as to display item of data in a second state, control circuits supplying a control voltage to the cell (28) to cause it to switch from the first state to the second state and vice versa, characterized in that the cell (28) is a display cell of the type including a diffusing or reflective liquid crystal in the second state.

Abstract: The assembly includes on the one hand a first device I determining a first colour, said device being formed of a liquid crystal display module (CL; CL1, CL2), including at the front and at the back a linear polariser (PAb1, PAb2) selective of said first colour, and on the other hand a second device 11 including a coloured filter (Fy) corresponding to the second colour. The assembly is characterised in that the axes of polarisation of the selective polarisers (PAb1, PAb2) are parallel to each other, in that the coloured filter (Fy) includes at the front a reflective polariser (PR1) whose axis of polarisation is parallel to the axes of polarisation of the two polarisers (PAb1, PAb2), and at the back a reflective element (R, PR2), and in that a control unit (7) enables a switching configuration to be defined displaying an item of information in the first colour on a background corresponding to the second colour or vice versa.

Abstract: The invention concerns a display assembly including two superposed, respectively upper (24) and lower (26) display devices, characterised in that the upper display device (24) including a display cell (28) arranged above an optical valve (30), said double structure being arranged so as to be transparent in a first state to make the lower display device visible (26), and so as to display an item of data in a second state, control means supplying a control voltage to the cell (28) to cause it to switch from the first state to the second state and vice versa, characterised in that said cell (28) is a display cell of the type including a diffusing or reflective liquid crystal in the second state.

Abstract: A display assembly is disclosed including an electro-optical cell (28), for example a liquid crystal cell, and a photovoltaic cell (61) acting as a back reflector for the latter. In order to improve the aesthetic appearance of the display, the photovoltaic cell (61) reflects predetermined wavelengths and thus exhibits a desired color in the transparent zones (90) of the electro-optical cell. In particular, the reflected light can be colored by reflection onto a multi-layered reflective filter including a transparent electrode (69) of the photovoltaic cell. This cell may form part of the dial of a watch.

Abstract: The assembly includes a first display device (22) in front of which is arranged a second active liquid crystal display device including, starting from the exterior, a front polariser (11) selective of a first colour “V”, a liquid crystal display cell (26) which is switchable ON/OFF, an intermediate polariser (13) selective of a second colour “R”, an ON/OFF switchable optical liquid crystal valve (28) and a rear polariser (15), which is reflective when the first display device (22) has a dark background and absorbent when it has a light background. A control unit (23) allows two switching states to be selected allowing the colour of the information displayed, or that of the background on which said information is displayed to be reversed.

Abstract: A liquid crystal composition comprising a low molecular weight liquid crystal in the interior of which a cross-linking network is formed by polymerization of a prepolymer of formula I: ##STR1## X being a non-mesogenic bivalent radical, the free bonds of which form an angle smaller than 180.degree.;B.sub.1 and B.sub.2 being rigid cyclic groups which would confer liquid crystal properties to the prepolymer if X was such that=180.degree..R.sub.1 and R.sub.2 being the same or different, each representing an optionally substituted alkyl, alkoxy, arylalkyl or aralalkoxy chain;A.sub.1 and A.sub.2 being the same or different, each representing a reactive polymerizable function. Display cells comprising the liquid crystal composition having a low commutation voltage.

Abstract: The liquid crystal cell with an alignment layer in the form of a soluble halogenated polymer of the ethylenic substituted ethylenic cycloaliphatic or heterocycloaliphatic type which induces homeotropic or planar alignment of the crystal molecules in contact therewith depending on whether the temperature is below or above a predetermined temperature T.sub.HP. The alignment layer may be a copolymer of tetrafluoroethylene with bis-2,2-trifluoromethyl-4,5-difluoro-1,3-dioxide.