Patent ID: 8339710
Filing Date: 2012-12-25
Classification: G02B

Abstract:
1. A head up display device for a vehicle, comprising: a display configured to display an image; a reflective member that is disposed rotatably relative to the display and configured to reflect the image displayed by the display and to project the image onto a projection member of the vehicle, thereby displaying a virtual image of vehicle-related information; a stepping motor configured to rotate the reflective member so as to adjust a display position of the virtual image, wherein: an operating switch configured to output an upward command signal or a downward command signal that indicates a request for the rotation of the magnet rotor; and a control part that is configured to control the drive signal to the coil based on the command signal inputted from the operating switch and that includes: an obtaining unit configured to obtain whether the rotation of the magnet rotor is requested based on the upward command signal or the downward command signal from the operating switch; a first drive mode unit configured to perform normal rotation control that controls the amplitude of the drive signal to rotate the magnet rotor to the target rotation angle so as to rotate the magnet rotor by a predetermined rotation angle in accordance with the command signal obtained by the obtaining unit; a first performance unit configured to perform application continuation control that continues the application of the drive signal for a predetermined period, with the amplitude of the drive signal at the target rotation angle being maintained, after the first drive mode unit performs the normal rotation control to rotate the magnet rotor to the target rotation angle, and then configured to put the coil into a non-magnetized state; a determination unit configured to determine whether a duration of the request for the rotation of the magnet rotor exceeds a predetermined determination time, wherein the determination unit determines that the operating switch is momentarily pressed when the duration of the request for the rotation is shorter than the determination time and determines that the operating switch is pressed for a long time when the duration of the request for the rotation is longer than the determination time; an ending unit configured to end the application continuation control and perform the normal rotation control so as to rotate the magnet rotor again when the duration of the request for the rotation is longer than the determination time; an obtaining unit configured to obtain a request to stop the rotation of the magnet rotor by obtaining no upward command signal or no downward command signal; and a second performance unit configured to perform the application continuation control and then to put the coil into the non-magnetized state when the request to stop the rotation is obtained, wherein when the request for the rotation is obtained again before the determination time elapses so that the magnet rotor needs to be rotated to a subsequent target rotation angle of the magnet rotor during the application continuation control, the control part stops the application continuation control and then performs the normal rotation control to rotate the magnet rotor to the subsequent target rotation angle by the first drive mode unit.