Abstract: A device having a sight line detecting function includes an illumination unit for illuminating an eyeball of an observer looking into an observation screen, by a plurality of light-emitting members; an image-pickup member which receives the light reflected from the eyeball; a rotational angle calculating device which calculates the rotational angle of the eyeball of the observer, using the cornea reflection images detected by the image-pickup member; and a correction unit for calculating correction data for correcting error between the calculated rotational angle value and the sight line of the observer, and for storing the correction data. In this device, the correction unit stores a plurality of correction data corresponding to the number of the cornea reflection images, with respect to the same observer.

Abstract: A device having a sight line detecting function includes an illumination unit for illuminating an eyeball of an observer looking into an observation screen, by a plurality of light-emitting members; an image-pickup member which receives the light reflected from the eyeball; a rotational angle calculating device which calculates the rotational angle of the eyeball of the observer, using the cornea reflection images detected by the image-pickup member; and a correction unit for calculating correction data for correcting error between the calculated rotational angle value and the sight line of the observer, and for storing the correction data. In this device, the correction unit stores a plurality of correction data corresponding to the number of the cornea reflection images, with respect to the same observer.

Abstract: A motor drive device capable of being connected with a camera body includes a communication line for communicating information on an operation mode of the motor drive device from the camera body to the motor drive device, a switch connected in series with the communication line and arranged to be closed when a battery connected to the motor drive device is a specific type of battery, and a control circuit which controls the motor drive device to operate in an operation mode based on the information on the operation mode communicated from the camera body when the switch is closed and to operate in a predetermined operation mode when the switch is opened.

Abstract: A movable optical unit includes a light beam deflector for preventing an image blur or the like. A position detector detects a position of the movable optical unit. The position detector incudes an arrangement for substantially pre-matching a center position of a displacement of the optical unit with a mechanical initial position of the optical unit. The mechanical initial position is, for example, a balanced position with gravity or a lock position. Thus, the center position of displacement can be pre-matched with the mechanical initial position. In addition, characteristics of the matching operation may be varied corresponding to an output of the position detector. Thus, the matching operation can be quickly performed.