Abstract: A device produces an electric field between two electrodes, the electric field having a specified value in the vicinity of a first of the two electrodes. The device includes a means for applying a potential difference between the two electrodes, means forming modulation electrode located near to the first electrode in the vicinity of which the electric field must have specified value. The device also includes control means for applying a potential difference between the means forming modulation electrode and the first electrode located nearby in order to obtain, through the contribution of the potential differences, the specified value of electric field.

Abstract: A microtip electron source including at least one electron emission zone composed of a plurality of microtips connected electrically to a cathode conductor. At least one gate electrode is positioned opposite the electron emission zone and pierced with apertures located opposite the microtips, to extract the electrons from the microtips. An emitted electron focusing gate is positioned opposite the gate electrode, and includes an aperture unit including at least one slit located opposite at least two successive microtips. A flat display screen can include such a microtip electron source. Further, a manufacturing process of such an electron source is disclosed.

Abstract: An apparatus for depositing a material by evaporation on a substrate having a large surface. The apparatus includes an enclosure in which are placed a number of material evaporation sources. It also includes a device for channeling or piping of vapors emitted by the sources toward the substrate during evaporation. This is formed by walls or covers which define compartments within the enclosure, each evaporation source being placed in a compartment. The apparatus can also utilize a device for moving the substrate in order to improve the uniformity of the deposit.

Abstract: The invention involves the making of a group of apertures spaced in a precise manner on a structure and including, for example, a first aperture made in a first layer and a second aperture made in a second layer which covers the first layer, the first aperture being located within the second aperture.

Abstract: A process for manufacturing a micropoint electron source with an extraction grid and a focusing grid. This process allows for precise alignment of the holes of the extraction grid with the apertures of the focusing grid by using a single photolithography step for making the holes in the extraction grid. Such a process may find particular application for making a micropoint electron source for a flat viewing screen.