Abstract: The present invention relates to an intervention blowout preventer (1) for being mounted on a well head (2) or a Christmas tree, comprising a plurality of valves (3, 4) arranged in fluid communication with each other, connected and forming a tubular pipe (5) enclosing a cavity being in fluid communication with the well head when the intervention blowout preventer is mounted onto the well head and at least one plug (37) in the well head has been removed, wherein the intervention blowout preventer further comprises a pressure reducing system (1) comprising a chamber (6) and a piston (7) arranged inside the chamber dividing the chamber into a first chamber part (8) and a second chamber part (9), the first chamber part being in fluid communication with the cavity and the second chamber part being filled with a compressible fluid, such as gas. Furthermore, the invention relates to a well intervention tool (100), a well intervention system (200) and a well intervention method.

Abstract: A system for detecting and automatically correcting X-Y errors in displayed image data. In a specific implementation, the invention (6, 10) includes a display driver ( 12, 14, 16, 4 ) for commanding the display ( 2 ) to display a picture element of an image at a predetermined position on a display screen thereof. The actual position of the displayed picture element is detected (6) and used to calculate a set of correction factors which are used in real time to correct the positioning of picture elements of actual image data (20, 24, 5).

Abstract: An image registration system for registering multiple images on a screen is disclosed. A single registration sensor, such as a photodetector, is disposed at an image plane of the system, typically adjacent an edge of the image plane of an image whose position is to be controlled and registered. A sensor mask having a square opening is disposed adjacent the photodetector, and between the image projector and the photodetector. A calibration light pattern is generated, illuminating the entire active area of the photodetector during a calibration time interval. The photodetector output is saved as a calibration value. A vertical test pattern is generated nominally illuminating only one vertical half of the sensor active area, and the sensor output is saved as a vertical pattern value. A horizontal test pattern is generated, nominally illuminating only one horizontal half of the sensor active area, and the sensor output is saved as a horizontal pattern value.

Abstract: A compensation arrangement for a display system that adaptively compensates the display parameters thereof for each pixel position to provide a precise display image that automatically adapts to the scan rate and aspect ratio of its sweep circuit. The sweep signals are sensed directly to define the actual instantaneous scan position. The sweep position is used to generate a compensation parameter for compensating the display signals. In a preferred embodiment, a lookup table is used to store compensation parameters, a compensation parameter is accessed from the table in response to the sweep signals, and the accessed compensation parameter is used to compensate the display signals.

Abstract: An electronic CRT centering alignment apparatus is disclosed. The apparatus includes a pair of zero crossing detectors, one sensing CRT horizontal deflection current, the other sensing CRT vertical deflection current. The zero crossing detectors are employed by the apparatus to generate video signals to mark the center of deflection of the CRT and to delineate the horizontal and vertical axes of deflection.

Abstract: An image registration system for registering multiple images on a screen is disclosed. A registration pattern is projected on the screen along with the image to be registered and in a fixed position in that image. A sensor apparatus for each image, having three photodetectors disposed in a right angle relationship is mounted on the screen at a predetermined location for determining the position of the registration pattern on the screen. The position of the registration pattern on the screen is determined by comparing the outputs of the three photodetectors. Difference signals are produced by the comparisons and are used to reposition the projected image to bring it into registration. The sensor apparatus are disposed so that when the registration patterns are in register with them, the images are in register with each other.

Abstract: A system for the transmission and reception of complex codes which provides a simple means for selection by an operator of the item to be encoded and transmitted. The invention allows the transmitted signal to be decoded and to be shown visually without requiring any assistance from an operator. Standard electrical and electronic components are used in the equipment of the invention. This invention is especially useful for signalling messages in Chinese or Japanese text, which both have a large number of characters and present difficulties in transmission and reception with conventional teleprinter machines.