Abstract: Image display apparatus comprising a projector, at least one primary modulator (4,6,8) for modulating light, an auxiliary modulator (36) for modulating the light modulated by the primary modulator, and an optical device (32) for relaying the light modulated by the primary modulator to the auxiliary modulator (36), the optical device (32) comprising a concave mirror and at least one refractive element.

Abstract: An acoustic source for delivering acoustic energy to a ground formation, particularly a rock formation, the source including (a) a solenoid to generate an electromagnetic field, (b) a bullet positioned within the influence of the electromagnetic field, (c) a casing surrounding and enclosing the solenoid and bullet so that both the solenoid and the bullet are protected from the surrounding environment, in use the solenoid being electrically energized to cause the bullet to be propelled by electromagnetic force so that the bullet impacts an anvil portion of the casing in contact with the ground formation is provided.

Abstract: A computer-based method is provided for modeling and visualizing a property of a subterranean earth formation while drilling a borehole therethrough. The computer-based method gathers electromagnetic signals corresponding to a current measurement station location of a measurement-while-drilling tool, and generates a multilayer model corresponding to such electromagnetic signals. A histogram characterizing uncertainty of the multilayer model is used to generate a set of color hue values which represent predictions of the formation property for depth values above/below the tool, and a corresponding set of saturation values (which represent uncertainties for these predictions). A curtain plot is generated and displayed. The curtain plot employs colors to visualize formation property predictions for depth values above/below the tool over successive measurement station locations. A new column of the curtain plot is generated for the current measurement station location.

Abstract: Illumination apparatus (8) which comprises at least two light sources, at least one light collecting device for collecting light from the light sources (10), motion providing means for providing relative motion between the light sources (10) and the light collecting device (14), and control means for controlling the illumination of the light sources (10) such that the light sources (10) are illuminated for a predetermined time period when in a predetermined position relative to the light collecting device (14).

Abstract: An eyepiece (2) for viewing a flat image, which eyepiece (2) has a wide field of view and which eyepiece (2) comprises a cemented doublet of reflecting and refracting optical components, the reflecting and refracting optical components being such that they are each of a different refractive index whereby chromatic aberrations and spherical aberrations are reduced.

Abstract: A novel method and apparatus is disclosed for the separation of fluid phases in borehole measurements. The method is based on selecting an optimum contrast mechanism and a corresponding set of measurement parameters for a particular borehole environment. The contrast mechanism can be based on, among others, diffusion, relaxation time or hydrogen index differences between different types of fluids. Once an initial measurement is made, the measurement parameters are compared to a predetermined set of values to broadly estimate the types of fluids present in the geologic environment. If necessary, the measurement is repeated to obtain optimal fluid typing for the estimated fluid types.

Abstract: A support structure (2) for elements forming part of an optical device, which support structure (2) is made of a polymer foam material. The support structure. (2) is lightweight. The optical device may be a head mounted display or a head mounted projector.

Abstract: Illumination apparatus (8) which comprises at least two light sources, at least one light collecting device for collecting light from the light sources (10), motion providing means for providing relative motion between the light sources (10) and the light collecting device (14), and control means for controlling the illumination of the light sources (10) such that the light sources (10) are illuminated for a predetermined time period when in a predetermined position relative to the light collecting device (14).

Abstract: A display device (2) for mobile telecommunications apparatus, which display device comprises: i) a display panel (4); ii) pancake optical means (6) for producing: a) a collimated image to an eye (8) of a viewer so that the image is able to be seen normally from distances as close as it is physically possible to get the eye (8) of the viewer to the display panel (4); and b) an un-collimated image which is equivalent to viewing the display panel (4) directly; iii) polarising filter means (10) for suppressing the un-collimated image; and iv) rotator means (14) for rotating at least part of the filter means (10) through 90° in order to allow the un-collimated image to be used, whereby the display device (2) is such that the user can select an un-collimated viewing mode if the image is of a simple content, and a viewer can select a collimated viewing mode if the image is of a detailed content.

Abstract: Image display apparatus (26) comprising a display panel (28), a screen (30), and image relay apparatus (2), the optical relay apparatus (2) comprising at least one aspherical polymer lens (8, 10, 12,14) and at least one spherical glass lens (4, 6), the said lenses being such that an image is able to be relayed from the display panel to the screen with a predetermined distortion, the optical relay apparatus (2) being such that it has a final aspherical polymer lens (14) which is the said aspherical polymer lens (8, 10, 12, 14) or one of the said aspherical polymer lenses, the final aspherical polymer lens (14) has a first depression (16) on a first side (18) and a second and larger depression (20) on a second side (22), the first side (18) being nearer to the display panel (28) than the second side (22), and the final aspherical polymer lens (14) directs light towards the screen (30) such that the direction of light rays complements the operation of an eyepiece used to view the screen (30).

Abstract: Borehole NMR logging apparatus and methods. A multifrequency method using triple-wait-time is disclosed for determining gas- and light-oil-filled porosity over a broad range of reservoir conditions. The method improves the signal-to-noise ratio and the determination of T1 values for the hydrocarbons, especially when the reservoir contains different fluid types. A set of conditions is derived for the selection of optimum acquisition parameters for logging applications. The data acquisition and processing method enables accurate determination of the pore volumes occupied by each hydrocarbon phase as well as the pore volume occupied by water, as well as accurate T1. A set of conditions is developed to aid in the selection of wait-time combinations appropriate for logging conditions.

Abstract: An eyepiece (2) for viewing a flat image, which eyepiece (2) has a wide field of view and which eyepiece (2) comprises a cemented doublet of reflecting and refracting optical components, the reflecting and refracting optical components being such that they are each of a different refractive index whereby chromatic aberrations and spherical aberrations are reduced.

Abstract: A novel method and apparatus is disclosed for the separation of fluid phases in borehole measurements. The method is based on selecting an optimum contrast mechanism and a corresponding set of measurement parameters for a particular borehole environment. The contrast mechanism can be based on, among others, diffusion, relaxation time or hydrogen index differences between different types of fluids. Once an initial measurement is made, the measurement parameters are compared to a predetermined set of values to broadly estimate the types of fluids present in the geologic environment. If necessary, the measurement is repeated to obtain optimal fluid typing for the estimated fluid types.

Abstract: Display apparatus (2) for displaying an image by back projection, which display apparatus (2) comprises a projector (4), a screen (6), and a quarterwave retarder (8), the screen (6) being a back projection screen (6) that maintains the polarisation state of incident light (10), the quarterwave retarder (8) being orientated such that its axis at 45° to the axis of polarised light (11) from the projector (4), and the quarterwave retarder (8) being such that it circularly polarizes linearly polarized light that it receives, for example from the projector (4) .

Abstract: A novel method and apparatus is disclosed for the separation of fluid phases in NMR borehole measurements. The method is based on selecting an optimum contrast mechanism and a corresponding set of measurement parameters for a particular borehole environment. The contrast mechanism can be based on diffusion, relaxation time or hydrogen index differences between different types of fluids. Once an initial measurement is made, the measurement parameters are compared to a predetermined set of values to broadly estimate the types of fluids present in the geologic environment. If necessary, the measurement is repeated to obtain optimal fluid typing for the estimated fluid types.