Bidirectional, cassette-loaded changer mechanism for overhead transparencies

A changer mechanism attachment for the automatic sequential display of a plurality of transparencies by an overhead projector having a light box with a light source and a cover glass, and optics positioned relative to the cover glass for projecting onto a remote viewing screen the image of a transparency brought into registration with the cover glass and illuminated by the light source, the changer mechanism comprising:

• a bin dimensioned, configured and adapted for receiving the plurality of transparencies loaded in a stack in the bin, the stack having front and rear sides;
• and
• transportation means for automatically feeding the transparencies one at a time sequentially from the stack into registration with the cover glass and then back to the bin;
• the transportation means comprising a first roller positioned to be adjacent to the loaded stack front side;
• a second roller laterally-spaced from the first roller and positioned to be adjacent to the loaded stack rear side;
• means for biasing the first and second rollers respectively against the loaded stack front and rear sides;
• and means for selectively driving the first or second roller in a pick-up rotational direction to pick up a transparency from the corresponding adjacent loaded stack front or rear side.

A changer mechanism attachment for the automatic sequential display of a plurality of transparencies by an overhead projector;

• the projector having a light box with a light source and a cover glass, and optics positioned relative to the cover glass for projecting onto a remote viewing screen the image of a transparency brought into registration with the cover glass and illuminated by the light source;
• and the changer mechanism having a bin, and transportation means for automatically feeding the transparencies, one at a time, sequentially from the bin into registration with the cover glass and then back to the bin;
• characterized in that:
• the bin is dimensioned, configured and adapted for receiving the plurality of transparencies loaded in a stack in the bin, the stack having front and rear sides;
• the changer includes means for cycling the transparencies in a forward direction through the stack, by sequentially picking the transparencies one at a time from the front side of the stack, moving them into registration with the cover glass and then returning them to the rear side of the stack;
• the means for cycling the transparencies in a forward direction comprising movable members defining a path for transport of the transparencies, means for driving the movable members to move transparencies along the path, circuitry including a microprocessor for controlling the means for driving, and sensor means, connected to the microprocessor, for monitoring the movement of transparencies transported along the path.

A changer mechanism attachment for the automatic sequential display of a plurality of transparencies by an overhead projector;

• the projector having a light box with a light source and a cover glass, and optics positioned relative to the cover glass for projecting onto a remote viewing screen the image of a transparency brought into registration with the cover glass and illuminated by the light source;
• and the changer mechanism having a bin, and transportation means for automatically feeding the transparencies, one at a time, sequentially from the bin into registration with the cover glass and then back to the bin;
• characterized in that:
• the bin is dimensioned, configured and adapted for receiving the plurality of transparencies loaded in a stack in the bin, the stack having front and rear sides;
• and
• the changer includes means for cycling the transparencies in a forward direction through the stack, by sequentially picking the transparencies one at a time from the front side of the stack, moving them into registration with the cover glass and then returning them to the rear side of the stack;
• and further includes means for locating and displaying a particular next desired transparency from the stack.

In combination with an overhead projector having a light box with a light source and a cover glass, and optics positioned relative to the cover glass for projecting onto a remote viewing screen the image of a transparency brought into registration with the cover glass and illuminated by the light source;

• a changer mechanism having a housing, a bin located in the housing for receiving a plurality of transparencies loaded in a stack in the bin, and transportation means for automatically feeding the transparencies, one at a time, sequentially from the stack loaded in the bin into registration with the cover glass;
• characterized in that:
• the stack has front and rear sides;
• the bin has a cavity;
• the changer further comprises a cassette having an interior and an exterior;
• the cassette interior being dimensioned, configured and adapted for receiving the stack of transparencies therein, and the cassette exterior being dimensioned, configured and adapted for being received within the bin cavity;
• and
• the means for feeding comprises means for cycling the transparencies in a forward direction through the stack by sequentially picking the transparencies one at a time from the front side of the cassette-loaded stack with the cassette loaded in the bin, moving the picked transparencies one at a time into registration with the cover glass, and then returning the registered transparencies one at a time to the rear side of the stack;
• means for cycling the transparencies backward through the stack by sequentially picking the transparencies one at a time from the rear side of the stack, moving the picked transparencies one at a time into registration with the cover glass, and then returning the registered transparencies one at a time to the front side of the stack;
• and means for selectively choosing between operation of the means for cycling in the forward direction and the means for cycling in the backward direction.

In combination with an overhead projector having a light box with a light source and a cover glass, and optics positioned relative to the cover glass for projecting onto a remote viewing screen the image of a transparency brought into registration with the cover glass and illuminated by the light source;

• a changer mechanism having a housing, a bin located in the housing for receiving a stack of transparencies, and transportation means for automatically feeding the transparencies, one at a time, sequentially from the stack loaded in the bin into registration with the cover glass;
• characterized in that:
• the changer housing comprises a horizontal portion having an unobstructed viewing area in alignment with the cover glass and first and second edges, and a vertical portion connecting one edge of the horizontal portion;
• the bin is located in the vertical portion;
• and the means for feeding comprises means for feeding the transparencies sequentially from the stack loaded in the bin, one at a time from the vertical portion to the horizontal portion, into registration with the cover glass, and then back to the stack.

A changer mechanism attachment for the automatic sequential display of a plurality of transparencies by an overhead projector;

• the projector having a light box with a light source and a cover glass, and optics positioned relative to the cover glass for projecting onto a remote viewing screen the image of a transparency brought into registration with the cover glass and illuminated by the light source;
• and the changer mechanism having a bin, and transportation means for automatically feeding the transparencies, one at a time, sequentially from the bin into registration with the cover glass and then back to the bin;
• characterized in that:
• the bin is dimensioned, configured and adapted for receiving the plurality of transparencies loaded in a stack in the bin, the stack having front and rear sides;
• and
• the changer includes means for cycling the transparencies in a forward direction through the stack, by sequentially picking the transparencies one at a time from the front side of the stack, moving them into registration with the cover glass and then returning them to the rear side of the stack;
• means for cycling the transparencies in a backward direction through the stack, by sequentially picking the transparencies one at a time from the rear side of the stack, moving them into registration with the cover glass, and then returning them to the front side of the stack;
• and means for selectively choosing between operation of the means for cycling in the forward direction and the means for cycling in the backward direction.