A head-mounted image display device with a good operability and a data
processing apparatus including such a display device. A head-mounted
image display device wherein a liquid crystal panel and an enlarging
optical system are crystal display panel through the enlarging optical
system housed in a frame and wherein images generated on the liquid are
visible in the field of view in front of the frame comprises a first
direction detection means (107) disposed in part of the frame (101) for
detecting the direction of the user's head; an observation point
detection means (109) disposed in part of the frame for detecting the
user's line of sight; a trigger input means (4) for transmitting trigger
signals; and an image generation means (3, 105) for controlling images
generated on the liquid crystal display panel based on signals from the
first direction detection, observation point detection, and trigger input
means.