An X-ray apparatus, comprising: an X-ray source configured to radiate X-rays; a collimator configured to adjust a radiation field of the X-rays and rotate on an optical axis direction of the X-rays; a ring-shaped first rotation transfer unit centered on an optical axis of the X-rays in the X-ray source; a second rotation transfer unit configured to be interlocked with the ring-shaped first rotation transfer unit and configured to rotate as the collimator rotates; a rotation sensor configured to sense, as a position signal, an amount of rotation of the second rotation transfer unit; a detector comprising a receiving surface on which the X-rays radiated from the collimator are incident; a controller; an image generator configured to generate an image signal based on a detection signal generated by the X-rays incident on the receiving surface of the detector; wherein the rotation sensor is adapted to transmit the extent of rotation of the collimator to the controller, and the controller is configured to determine an extent of rotation of the detection signal based on the amount of rotation of the collimator and information about the position of the detector and adapted to transmit the extent of rotation of the detection signal generated by the receiving surface of the detector, to an image display unit, and an output unit configured to output a corrected image based on the image signal generated by the image generator, using the image signal received from the image display unit, wherein the image display unit is further configured to receive, from the controller, the extent of rotation of the detection signal, and generate a corrected image signal based on the extent of rotation of the detection signal. an X-ray source configured to radiate X-rays; a collimator configured to adjust a radiation field of the X-rays and rotate on an optical axis direction of the X-rays; a ring-shaped first rotation transfer unit centered on an optical axis of the X-rays in the X-ray source; a second rotation transfer unit configured to be interlocked with the ring-shaped first rotation transfer unit and configured to rotate as the collimator rotates; a rotation sensor configured to sense, as a position signal, an amount of rotation of the second rotation transfer unit; a detector comprising a receiving surface on which the X-rays radiated from the collimator are incident; a controller; an image generator configured to generate an image signal based on a detection signal generated by the X-rays incident on the receiving surface of the detector; wherein the rotation sensor is adapted to transmit the extent of rotation of the collimator to the controller, and the controller is configured to determine an extent of rotation of the detection signal based on the amount of rotation of the collimator and information about the position of the detector and adapted to transmit the extent of rotation of the detection signal generated by the receiving surface of the detector, to an image display unit, and an output unit configured to output a corrected image based on the image signal generated by the image generator, using the image signal received from the image display unit, wherein the image display unit is further configured to receive, from the controller, the extent of rotation of the detection signal, and generate a corrected image signal based on the extent of rotation of the detection signal.