Abstract: The invention relates to a 2N pole claw rotor comprising a first magnetic material part, comprising an axial hub having a free end, and an end provided with N axially-extending claws that are peripherally localized, uniformly distributed, and together define a bezel; a second magnetic material part of polarity opposite to the polarity of the first magnetic material part, having the same shape as the first magnetic material part, and disposed facing the first magnetic material part, each claw of the second magnetic material part being disposed between two claws of the first magnetic material part, and vice versa; non-magnetic spacers interposed between the free ends of the claws and the end walls of the bezels of the facing parts; and non-magnetic rotor-cowling means.

Abstract: A synchronous machine rotor has a progressive magnetic airgap and a constant aerodynamic airgap.

Abstract: The variable-focal-length objective for motion-picture cameras and especially color television cameras comprises two movable groups of lens elements placed between two stationary groups of lens elements and capable of displacement so as to produce a variation of the focal distance. In this objective, the two movable groups each take part in the total variation of magnification; each elementary magnification has a minimum and maximum absolute value during the variation, such that the ratio of maximum value to minimum value is higher than 1:1. However, only one of the two movable groups which does not pass through a magnification of unity performs both a magnification function and an additional focusing function. On the other hand, the other movable group which may pass through a position corresponding to a magnification of unity performs only a magnification function.

Abstract: These device and method for adjusting the value of the chromatism and distortion aberrations in an optical system, notably for color television cameras, by using a diascope from which a color image is injected into the optical system, comprises an assembly of at least four prismatic blades forming two optically parallel groups of variable thickness, each group comprising two such blades, the blades consisting of transparent materials having the same index of refraction and the same index of dispersion of the blades of the same group, but a different index of dispersion for each group, with control means for varying the thickness of each group while preserving a constant total thickness.

Abstract: An optical device comprising at least an optical element having a cut away area and which supports an inner mechanical structure accommodated in the cut away area, the whole being supported by an outer mechanical structure without obstruction in the optical path between the structures. The contact areas of the optical element with the structures comprise mechanical gripping and position means including deformable members for holding an unvaried centered position to the optical element for severe temperature and mechanical operating conditions.