33results about How to "Easy and accurate calibration" patented technology

A calibration apparatus for an image forming apparatus includes a calculation unit for calculating a color deviation by subtracting a target value from each value on the two orthogonal axes not including brightness of a color coordinate system based on a measured color value of a printed material and a display unit for displaying the color deviation with respect to each gray balance at the feedback such that the number of times of inversions of a sign of the color deviation calculated by the calculation unit and a variation width of the color deviation when the sign of the color deviation is inverted can be detected.

A by-pass and pressure regulator valve exhibiting: an inlet mouth and an outlet mouth set in reciprocal communication by a main conduit; a by-pass mouth. The by-pass and pressure regulator valve comprises: an obturator, mobile between at least a closed position, in which it interrupts fluid communication between the main conduit and the by-pass mouth, and at least an open position, in which the fluid communication is not interrupted; operating pressure control means, predisposed to move the obturator from the closed position; means for determining a flow pressure loss in fluids crossing the main conduit, arranged along the main conduit in order to separate a first tract upstream of the main conduit from a second tract downstream thereof; obturator command means governed by a fluid pressure difference between the first tract and the second tract of the main conduit, distinct from the operating pressure control means but operatively connected to the obturator.

The invention discloses a position calibrating method of a medical ultrasonic three-dimensional imaging based on linear scanning, comprising the steps that a rectangular solid with known sizes is used as a scanning object, on the premise of assuming that an angle conversion relationship does not exist between an original ultrasonic image plane and a linear guide rail, a two-dimensional image is subjected to the three-dimensional reconstruction, and then an actual mathematic relationship of the angle and the deformation amount of the reconstructed rectangular solid between the original ultrasonic image plane and the linear guide rail can be calculated; and in the actual calibrating process, the rectangular solid is scanned by a linear scanning method, the sequence of the ultrasonic image is subjected to the three-dimensional reconstruction, the deformation amount of the reconstructed rectangular solid is substituted into a mathematic relationship to calculate the rotation angle between the original ultrasonic image plane (i.e. the position of an ultrasonic probe) and the linear guide rail, and the rotation angle is the calibrating result of the position of the ultrasonic probe in the linear scanning mode. The position calibrating method has the advantages that the simplicity and the easy understanding are realized, the operability is high, the test is simple, and the calibrating is convenient and accurate. The position calibrating method can be used for a three-dimensional ultrasonic imaging system based on a free arm linear scanning method or a mechanical driving linear scanning method.