Abstract: Described here is a method for performing phase contrast imaging using an array of independently controllable x-ray sources. The array of x-ray sources can be controlled to produce a distinct spatial pattern of x-ray radiation and thus can be used to encode phase contrast signals without the need for a coded aperture. The lack of coded aperture increases the flexibility of the imaging method. For instance, because a fixed, coded aperture is not required, the angular resolution of the imaging technique can be increased as compared to coded-aperture imaging. Moreover, the lack of a radioopaque coded aperture increases the photon flux that reaches the subject, thereby increasing the attainable signal-to-noise ratio.

Abstract: An x-ray source for use in Phase Contrast Imaging is disclosed. In particular, the x-ray source includes a cathode array of individually controlled field-emission electron guns. The field emission guns include very small diameter tips capable of producing a narrow beam of electrons. Beams emitted from the cathode array are accelerated through an acceleration cavity and are directed to a transmission type anode, impinging on the anode to create a small spot size, typically less than five micrometers. The individually controllable electron guns can be selectively activated in patterns, which can be advantageously used in Phase Contrast Imaging.

Abstract: A liquid crystal display having pixels illuminated by field emitter arrays. The field emitter arrays may be utilized to illuminate each pixel individually or to be a backlight lamp to illuminate the whole display, whether monochrome or color. A field emitter array back-lighted liquid crystal displays, whether active matrix or passive, provide greater compactness, higher luminous efficiency, more brightness, and longer lifetime than a fluorescent lamp. Field-emitter arrays may also provide light in various colors for the liquid crystal display thereby eliminating the need for color filters which result in duller colors than that of field emitter arrays. Each color filter absorbs two-thirds of the light that it receives. A color filter liquid crystal color display exhibits colors that have diminished chromaticity and purity in comparison to those of a field emitter array liquid crystal display.