Abstract: A system for making a holographic medium for use in generating light patterns for eye tracking includes a light source configured to provide light and a beam splitter configured to separate the light into a first portion of the light and a second portion of the light that is spatially separated from the first portion of the light. The system also includes a first set of optical elements configured to transmit the first portion of the light for providing a first wide-field beam onto an optically recordable medium, a second set of optical elements configured to transmit the second portion of the light for providing a second wide-field beam, and a plurality of parabolic reflectors optically coupled with the second set of optical elements and configured to receive the second wide-field beam and project a plurality of separate light patterns onto the optically recordable medium for forming the holographic medium.

Abstract: A quadrupole responder for an OQR-type gravity gradiometer comprises a housing, and a mass quadrupole positioned within the housing. The mass quadrupole has a pair of sides, and also has a center of mass between the sides. At least a pair of torsion spring flexures are provided by pins connecting said side of said mass quadrupole to the housing. The torsion spring flexures provide an axis of rotation which passes through the center of mass of the mass quadrupole and through both spring flexures. The pins are integral with the mass quadrupole.

Abstract: The present invention proposes a torsion balance apparatus with high sensitivity and accuracy to measure extremely small rotation angle. The torsion balance apparatus comprises a bar which rotates and is horizontally suspended by a suspending fiber, a light source, a detector and a light reflecting system which reflects the light beam from the light source several times and reaches to the detector.

Abstract: A quadrupole responder for an OQR-type gravity gradiometer comprises a housing, and a mass quadrupole positioned within the housing. The mass quadrupole has a pair of sides, and also has a center of mass between the sides. At least a pair of torsion spring flexures are provided by pins connecting said sideof said mass quadrupole to the housing. The torsion spring flexures provide an axis of rotation which passes through the center of mass of the mass quadrupole and through both spring flexures. The pins are integral with the mass quadrupole.

Abstract: A quadrupole responder for an OQR-type gravity gradiometer comprises a housing, and a mass quadrupole positioned within the housing. The mass quadrupole has a pair of sides, and also has a center of mass between the sides. At least a pair of torsion spring flexures are provided by pins connecting said side of said mass quadrupole to the housing. The torsion spring flexures provide an axis of rotation which passes through the center of mass of the mass quadrupole and through both spring flexures. The pins are integral with the mass quadrupole.

Abstract: A quadrupole responder for an OQR-type gravity gradiometer comprises a housing, and a mass quadrupole positioned within the housing. The mass quadrupole has a pair of sides, and also has a center of mass between the sides. The quadruple responder further comprises at least two torsion spring flexures. The torsion spring flexures are provided by pins connecting each side of the mass quadrupole to the housing. The torsion spring flexures provide an axis of rotation which passes through the center of mass of the mass quadrupole and through both torsion spring flexures.

Abstract: A quadrupole responder for an OQR-type gravity gradiometer comprises a housing, and a mass quadrupole positioned within the housing. The mass quadrupole has a pair of sides, and also has a center of mass between the sides. At least a pair of torsion spring flexures are provided by pins connecting said side of said mass quadrupole to the housing. The torsion spring flexures provide an axis of rotation which passes through the center of mass of the mass quadrupole and through both spring flexures. The pins are integral with the mass quadrupole.

Abstract: A quadrupole responder for an OQR-type gravity gradiometer comprises a housing, and a mass quadrupole positioned within the housing. The mass quadrupole has a pair of sides, and also has a center of mass between the sides. The quadruple responder further comprises at least two torsion spring flexures. The torsion spring flexures are provided by pins connecting each side of the mass quadrupole to the housing. The torsion spring flexures provide an axis of rotation which passes through the center of mass of the mass quadrupole and through both torsion spring flexures.

Abstract: A gravity gradiometer is disclosed which has a sensor in the form of bars (41 and 42) which are supported on a mounting (5) which has a first mount section (10) and a second mount section (20). A first flexure web (33) pivotally couples the first and second mount sections about a first axis. The second mount has a first part (25), a second part (26) and a third part (27). The parts (25 and 26) are connected by a second flexure web (37) and the parts (26 and 27) are connected by a third flexure web (35). The bars (41 and 42) are located in housings (45 and 47) and form a monolithic structure with the housings (45 and 47) respectively. The housings (45 and 47) are connected to opposite sides of the second mount section 20. The bars (41 and 42) are connected to their respective housings by flexure webs (59). Transducers (71) are located in proximity to the bars for detecting movement of the bars to in turn enable the gravitational gradient tensor to be measured.

Abstract: A gravity gradiometer is described which comprises a pair of sensor bars 41, 43 arranged in housings 45, 47. Transducers 71 are arranged adjacent the bars 41, 43 for measuring movement of the bars in response to the gravity gradient tensor. At least one of the transducers has a sensing coil 510 and a capacitor plate 518a having a concentric arrangement with the sensing coil 510 for providing one plate of a capacitor used in a balancing circuit for measuring the balance of the sensor mass.

Abstract: The invention relates to a gravity measurement apparatus comprising a torsion balance bearing a test mass. The torsion balance has a predetermined center of mass and is rotatable around a predetermined rotation axis, wherein the torsion balance is asymmetric in such a way that the center of mass of the torsion balance is offset to the rotation axis of the torsion balance.

Abstract: An apparatus and a method for manufacturing a thick-walled bent pipe with a simple structure at low production cost, which has durability and can manufacture an elbow material for piping with higher size accuracy, are provided. For this purpose, the manufacturing apparatus is a manufacturing apparatus comprising a presser die (12) and a lower die (20), in which the lower die (20) includes a pair of bottom dies (21, 22) having meshing means (30), and a pair of the bottom dies (21, 22) are allowed to rotate opposite to each other by the meshing means (30), in connection with a descent of the presser die.

Abstract: A gravity meter comprises a casing, a vacuum tube mounted in the casing in a vibration-free manner, a sensor mechanism mounted within the vacuum tube, the sensor mechanism comprising two masses of different size acting on the respective arms of a beam balance comprising a material whose shape is arranged to change in response to changes in gravity and whose shape can be restored by the application of an electrical current thereto, and detector means arranged to provide from the restoring current an output representative of changes in gravity. The material is preferably a piezoelectric material.

Abstract: An apparatus for measuring moment of inertia incorporating a torsional pendulum and an analog electronic circuit. The circuit measures the period of oscillation, sets a scaling factor equal to the torsional coefficient of the resilient member, and computes moment of inertia by multiplying the scaling factor by the square of the period of oscillation. The moment of inertia is then displayed in metric units.