Light width controller and image projector employing the same

Claim 2

A light width controller comprising a light width controlling mirror of a refractive index n2, said mirror having: a first surface formed to have a predetermined angle a1 with respect to horizontal; a second surface formed to have a different predetermined angle a2 with respect to horizontal such that said first surface is not parallel to said second surface; and a reflection layer formed against said second surface for reflecting light incident on said second surface, said light having passed through a medium of a refractive index of n1 smaller than n2 and then having passed through said first surface prior to being incident on said second surface.

Claim 3

A light width controller as claimed in claim 1, wherein said angle a2 is larger than said angle a1 and said angle a2 equals a1+1/2*arcsin { cos a1*(n 2 sin 2 a1) 1/2 -sin a1*(n 2 -cos 2 a1)!/n 2 }, where n is an index of refraction and where n2 equals n for n1=1.

Claim 4

A light width controller as claimed in claim 1, wherein n1 is a refractive index of air.

Claim 5

A light width controller as claimed in claim 1, wherein n2 has a value in the range of 1.4≦n2≦2.0.

Claim 6

A light width controller as claimed in claim 1, wherein: said first and second surfaces define two lines, respectively, that intersect at a point; and a width of light incident on said first surface in direction generally pointing away from said point of intersection is enlarged in width by said light width controlling mirror while a width of light incident on said first surface in a direction generally pointing toward said point of intersection is reduced in width by said light width controlling mirror.

Claim 7

An image projector utilizing a light width controller, said projector comprising: a light source; a light width controller having a light width controlling mirror of a refractive index n2, said mirror having: a first surface formed to have a predetermined angle a1 with respect to horizontal; a second surface formed to have a different predetermined angle a2 with respect to horizontal such that said first surface is not parallel to said second surface; and a reflection layer formed against said second surface for reflecting light incident on said second surface, said light having passed through a medium of a refractive index of n1 smaller than n2 and then having passed through said first surface prior to being incident on said second surface; image display means for displaying an image with a light width controlled by said light width controller; a projection lens for enlarging an image formed in said image display means; and a screen for projecting the image focused by said projection lens.

Claim 8

An image projector utilizing a light width controller, said projector comprising: a light source; a light width controller having a light width controlling mirror of a refractive index n2, said mirror having: a first surface formed to have a predetermined angle a1 with respect to horizontal; a second surface formed to have a different predetermined angle a2 with respect to horizontal such that said first surface is not parallel to said second surface; and a reflection layer formed against said second surface for reflecting light incident on said second surface, said light having passed through a medium of a refractive index of n1 smaller than n2 and then having passed through said first surface prior to being incident on said second surface; image display means for displaying an image with a light width controlled by said light width controller; a projection lens for enlarging an image formed in said image display means; and a screen for projecting the image focused by said projection lens.

Claim 9

An image projector as claimed in claim 6, wherein said image display means is a film.

Claim 10

An image projector as claimed in claim 6, wherein said angle a2 is larger than said angle a1 and said angle a2 equals a1+1/2*arcsin { cos a1*(n 2 sin 2 a1) 1/2 -sin a1*(n 2 -cos 2 a1)!/n 2 }, where n is an index of refraction and where n2=n for n1=1.

Claim 11

An image projector as claimed in claim 6, wherein n1 is a refractive index of air.

Claim 12

An image projector as claimed in claim 6, wherein n2 has a value in the range of 1.4≦n2≦2.0.

Claim 13

An image projector as claimed in claim 6, wherein said light width controller further includes a condensing lens for collecting light emitted via the light width controlling mirror.

Claim 14

An image projector as claimed in claim 6, wherein said image display means includes a liquid crystal panel.

Claim 15

A light projector as claimed in claim 6, wherein: said first and second surfaces define two lines, respectively, that intersect at a point; and a width of light incident on said first surface in direction generally pointing away from said point of intersection is enlarged in width by said light width controlling mirror while a width of light incident on said first surface in a direction generally pointing toward said point of intersection is reduced in width by said light width controlling mirror.