Projection apparatus

1. A projection apparatus comprising:

a housing;

a transmission-type screen provided on a front side of said housing;

an optical engine provided in said housing, said optical engine projecting an image on said transmission-type screen from a rear side of said transmission-type screen;

an engine supporting plate on which said optical engine is placed, said engine supporting plate being provided in said housing so that an angle of said engine supporting plate is adjusted to thereby adjust a projecting direction of said optical engine;

a base portion provided on an inner bottom surface of said housing;

an adjusting member having a substantially wedge-shape with nonparallel upper and lower surfaces, said adjusting member being inserted into between said base portion and a lower surface of said engine supporting plate, so that front or rear end of said engine supporting plate is vertically rotatable;

a front-to-rear position adjusting unit capable of pushing said adjusting member frontward and pulling said adjusting member rearward;

a slope portion having a slope surface that gradually increases or decreases an angle of a surface of said adjusting member that contacts said engine supporting plate in accordance with a movement of said adjusting member in front-to-rear direction, and

a fixing unit that fixes said engine supporting plate to an adjusted position, wherein said engine supporting plate has a convex-shaped center shaft protrusion at an end thereof opposite to a vertically rotated end, and

wherein said base portion has a center shaft receiving portion in the form of a concave or through-hole capable of receiving said center shaft protrusion.

2. A projection apparatus comprising:

a housing;

a transmission-type screen provided on a front side of said housing;

an optical engine provided in said housing, said optical engine projecting an image on said transmission-type screen from a rear side of said transmission-type screen;

an engine supporting plate on which said optical engine is placed, said engine supporting plate being provided in said housing so that an angle of said engine supporting plate is adjusted to thereby adjust a projecting direction of said optical engine;

a base portion provided on an inner bottom surface of said housing;

an adjusting member having a substantially wedge-shape with nonparallel upper and lower surfaces, said adjusting member being inserted into between said base portion and a lower surface of said engine supporting plate, so that front or rear end of said engine supporting plate is vertically rotatable;

a front-to-rear position adjusting unit capable of pushing said adjusting member frontward and pulling said adjusting member rearward;

a slope portion having a slope surface that gradually increases or decreases an angle of a surface of said adjusting member that contacts said engine supporting plate in accordance with a movement of said adjusting member in front-to-rear direction, and

a fixing unit that fixes said engine supporting plate to an adjusted position, wherein said base portion has a convex-shaped center shaft protrusion at a position facing an end of said engine supporting plate opposite to a vertically rotated end, and

wherein said engine supporting plate has a center shaft receiving portion in the form of a concave or through-hole capable of receiving said center shaft protrusion.

3. The projection apparatus according to claim 1 , wherein said center shaft protrusion has a shape such that said center shaft protrusion functions as a rotational axis in vertical and horizontal directions, and has a dimension such that said center shaft protrusion can be inserted into said center shaft receiving portion, and

wherein said center shaft receiving portion has shape and dimension such that said center shaft receiving portion is able to receive said center shaft protrusion.

4. The projection apparatus according to claim 3 , wherein said center shaft protrusion is provided on a front end of said engine supporting plate, and

wherein said center shaft receiving portion is provided on said base portion.

5. The projection apparatus comprising:

an optical engine that projects an image;

an optical engine placing unit on which said optical engine is placed;

a supporting unit supporting said optical engine placing unit so that said optical engine placing unit is rotatable about a predetermined axis, wherein said supporting unit has a convex-shaped center shaft protrusion at an end thereof opposite to a vertically rotated end;

a center shaft receiving portion in the form of a concave or through-hole capable of receiving said center shaft protrusion; and

an adjusting unit rotating said optical engine placing unit about said predetermined axis, to thereby adjust a projecting direction of said optical engine,

wherein said adjusting unit comprises:

an adjusting member having an arcuate surface having a center at a predetermined point, and

a guide portion that guides said adjusting member along said arcuate surface.

6. The projection apparatus comprising:

an optical engine that projects an image;

an optical engine placing unit on which said optical engine is placed;

a supporting unit supporting said optical engine placing unit so that said optical engine placing unit is rotatable about a predetermined axis;

a convex-shaped center shaft protrusion at a position facing an end of said supporting unit opposite to a vertically rotated end, wherein said supporting unit has a center shaft receiving portion in the form of a concave or through-hole capable of receiving said center shaft protrusion; and

an adjusting unit rotating said optical engine placing unit about said predetermined axis, to thereby adjust a projecting direction of said optical engine,

wherein said adjusting unit comprises:

an adjusting member having an arcuate surface having a center at a predetermined point, and

a guide portion that guides said adjusting member along said arcuate surface.