Natural lighting apparatus

Claim 1

A natural lighting apparatus comprising: a. a plane mirror having a plane mirror face for reflecting light therefrom in a front direction; b. a supporting means for supporting the mirror for rotation about both a first vertical axis parallel to said plane mirror and a second horizontal axis parallel to said plane mirror and perpendicular to the first vertical axis, said supporting means comprising an outer frame and an inner frame supported on the outer frame for rotation about the first vertical axis, said plane mirror being supported on the inner frame to be rotatable about the second horizontal axis; c. a first sensing means for sensing the direction of the light source relative to and about the first vertical axis, and for generating a first signal representative thereof, said first sensing means including a pair of first photosensors for receiving light from the light source to generate the first signal; d. a second sensing means for sensing the direction of the light source relative to and about the second horizontal axis, and for generating a second signal representative thereof, said second sensing means including a pair of second photosensors for receiving light from the light source to generate the second signal; e. an attitude control means for angularly moving the mirror about the first axis in accordance with the first signal from the first sensing means and about the second axis in accordance with the second signal from the second sensing means, thus controlling the attitude of the mirror to reflect light from the light source in a predetermined direction, said attitude control means comprising a light source following lever, mounted to said inner frame for pivotal movement about the second horizontal axis, and a slider link means, connecting the mirror to both the inner frame and the light source following lever, for controlling an angle defined between the mirror and the inner frame about the second horizontal axis to be one half of an angle defined between the inner frame and the light source following lever about the horizontal axis, to thereby reflect light from the light source in the predetermined direction, said first sensing means being mounted to the inner frame, and said second sensing means being mounted to the light source following lever, and wherein said attitude control means comprises a first rotation unit for rotating the inner frame about the first vertical axis, and a second rotation unit for rotating the mirror about the second horizontal axis, wherein the attitude control means further comprises a control unit for comparing the signals from the first photosensors to control the first rotation unit to rotate the inner frame so as to direct the mirror in the first light source direction and for comparing the signals from the second photosensors to control the second rotation unit to rotate the inner frame to direct the mirror in the second light source direction.