Dual-use optical projection apparatus

Claim 2

An optical projection apparatus comprising a light source; a screen disposed in a path of light from said light source for projecting thereon an image of a film; film-loading means for releasabily mounting a film between said light source and said screen in said light path; light-intercepting means for screening a predetermined part of said image projected on said screen and including a plurality of light-intercepting plates for screening a plurality of predetermined sections of said part of said image, respectively, each of said light-intercepting plates being independently movable between a light-intercepting position defined between said screen and said light source in said light path for screening a corresponding one of said sections and a non-intercepting position defined outside said light path for preventing said corresponding section from being screened; control means for controlling the movement of said lightintercepting plates; and holding means for holding all of said light-intercepting plates at their non-intercepting positions for permitting said image to be completely projected on said screen.

Claim 3

An optical projection apparatus according to claim 1, in which said light-intercepting means comprises a frame on which said light-intercepting plates are movable mounted, said frame being movable between a first position where said light-intercepting plates are movable and a second position where said light-intercepting plates are incapable of preventing said sections of said image on the film from being projected on the screen.

Claim 4

An optical projection apparatus according to claim 2, comprising a means for holding said frame at the first and second positions.

Claim 5

An optical projection apparatus according to claim 2, comprising a magnetic tape recording-and-reproducing means for describing the image projected on said screen; said magnetic tape recording-and-reproducing means including a film-feeding signal detector circuit which detects film-feeding signals recorded on the magnetic tape together with signals for describing the image and produces an output, and an automatic stop circuit which not only automatically stops the feed of the magnetic tape when an output signal of said film-feeding signal detector circuit is applied to said automatic stop circuit, but also has a manual feeding circuit for restarting the tape feed as desired; said film-loading means comprising a film-feeding means for feeding the film in sequence, a film-feeding circuit which not only drives said film-feeding means when an output signal of said film-feeding signal detector circuit is applied to said film-feeding circuit, but also has a manual control circuit interlocked with said manual feeding circuit to operate said film-feeding means manually, and a frame position detector circuit including a first switch inserted between said film-feeding signal detector circuit and said automatic stop circuit and a second switch inserted between said film-feeding signal detector circuit and said film-feeding circuit, said first and second switches being adapted to close and open respectivelY at said first frame position and to open and close respectively at said second frame position.

Claim 6

An optical projection apparatus according to claim 4, in which said light-intercepting means includes a frame-holding means which operates in concert with the movement of said frame to the second position.

Claim 7

An optical projection apparatus according to claim 2, in which said film-loading means comprises a film-feeding means for feeding the film in sequence, a film-feeding circuit for driving said film-feeding means, a signal circuit for generating a signal for energizing said film-feeding circuit, and a frame position detector circuit inserted between said film-feeding circuit and said signal circuit, said frame position detector circuit having a contact which detects the position of said frame and closes at the second frame position, said film-feeding circuit including a manual control circuit for energizing said film-feeding circuit manually as desired.

Claim 8

An optical projection apparatus according to claim 2, in which said frame is supported on one shaft so as to be rotatable between said first position where said frame is in parallel with said screen and said second position where said frame is at right angles or more to the screen, said frame including a plurality of openings corresponding to said light-intercepting plates each independently movable between a light-intercepting position where a corresponding one of said openings is closed and a non-light-intercepting position where a corresponding one of said openings is opened, said light-intercepting plates being usually held at the light-intercepting position by a unidirectional force, said light-intercepting plates being interlocked with a control board for moving said light-intercepting plates to the non-light-intercepting position against said unidirectional force when said frame is at the first position.

Claim 9

An optical projection apparatus according to claim 7, in which each of said light-intercepting plates is movable between a non-light-intercepting position where said light-intercepting plate is released from a corresponding opening by a rotating shaft provided on one side of said opening and a light-intercepting position where said light-intercepting plate is returned to the opening by the rotating shaft, said light-intercepting plates being usually held at the light-intercepting position by said unidirectional force, said control board having an engaging member which engages with said winding shaft to enable rotation of said light-intercepting plate against said unidirectional force only at the first position of said frame.

Claim 10

An optical projection apparatus according to claim 7, in which each of said light-intercepting plates is supported coaxially with a rotary shaft of said frame so as to be independently rotatable between the light-intercepting position and the non-light-intercepting position, said light-intercepting plates being usually held at the light-intercepting position by means of a spring, said control board being integrated with said light-intercepting plates.

Claim 11

An optical projection apparatus according to claim 1, in which each of said light-intercepting plates is marked with a character, numeral or a symbol on the front of the same so as to be visible through said screen when said light-intercepting plate is positioned at the light-intercepting position.