Abstract: A display device for a portable instrument includes at least a first transparent or semi-transparent plate arranged on a bottom element. Several closed cavities are formed at least in part in the first plate in the field of view of the device to display information. Each cavity is connected by a respective channel through the bottom element to a tank of colored fluid via feed means for filling or emptying each closed cavity of colored fluid for displaying information. The feed means include at least one micropump connected by an inlet pipe to the colored fluid tank, and microvalves connected to the micropump by a common outlet pipe. Each cavity is directly connected via its respective channel to a corresponding microvalve. The micropump and the microvalves are controlled by electric signals from control means, which can be clocked by a time base in order to control display of time information.

Abstract: A display device for a portable instrument includes at least a first transparent or semi-transparent plate arranged on a bottom element. Several closed cavities are formed at least in part in the first plate in the field of view of the device to display information. Each cavity is connected by a respective channel through the bottom element to a tank of coloured fluid via feed means for filling or emptying each closed cavity of coloured fluid for displaying information. The feed means include at least one micropump connected by an inlet pipe to the coloured fluid tank, and microvalves connected to the micropump by a common outlet pipe. Each cavity is directly connected via its respective channel to a corresponding microvalve. The micropump and the microvalves are controlled by electric signals from control means, which can be clocked by a time base in order to control display of time 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.