Focusing roll and displacement prisms

Claim 2

Optical apparatus for selectively controlling the transmission of a light image therethrough comprising: a pair of similar prisms each having substantially the same angular construction, an entry-exit or first surface opposite the smallest or first of the three prism angles for transmitting light images therethrough, a hypotenuse or second surface opposite the largest or second of the three prism angles for selectively reflecting and transmitting light images impinging thereon, and a third surface opposite the third angle for reflecting light images impinging thereon, a first prism of said pair arranged for receiving at its entryexit surface a light image traveling along a first optical axis of said apparatus, said received image being internally reflected from said hypotenuse surface and said third surface, respectively, prior to being transmitted through said hypotenuse surface, said first prism being further arranged such that the angle of incidence of said light image at said hypotenuse surface is greater than the critical angle when reflection of the image is required and less than the critical angle when transmission is required, a second prism of said pair being arranged so that its hypotenuse surface is parallel and adjacent to the hypotenuse surface of said first prism for receiving said light image from said first prism and then, subsequent to internally reflecting said light image from said third surface and said hypotenuse surface, respectively, transmitting said light image through said entry-exit face of said second prism along a second optical axis parallel to said first optical axis; and means for selectively positioning one of said first an second prisms along a first line which makes an angle with said second optical axis, which angle is equivalent to the third prism angle, to change the path length of said light image through said optical apparatus.

Claim 3

The invention according to claim 1 and further including means to selectively position one of said prisms along a second line perpendicular to said first line whereby the offset of said second axis from a projection of said first axis may be controlled.

Claim 4

The invention according to claim 1 wherein the third surfaces of said first and second prisms have a specular coating applied thereto.

Claim 5

The invention according to claim 1 wherein said entry-exit faces of said first and second prisms are perpendicular to said first and second optical axis and wherein a roof comprises the third surface of one of said prisms.

Claim 6

The invention according to claim 4 and further including means to position said one prism with a roof along a third line, said third line being perpendicular to a plane bisecting the angle of the peak of said roof whereby offset of said second from said first axis in a first direction may be controlled.

Claim 7

The invention according to claim 4 and further including means to roll said prisms around one of said first and second axes.

Claim 8

The invention according to claim 4 and further including means to selectively position one of said prisms along a second line perpendicular to said first line whereby the offset of said second axis from the projection of said first axis in a second direction may be controlled.

Claim 9

Optical apparatus for selectively controlling the transmission of a light image therethrough comprising: a mirror having its reflecting surface parallel to a first optical axis of said apparatus; a pair of similar prisms each having substantialy the same angular construction, an entry-exit or first surface opposite the smallest or first of the three prism angles for transmitting light images therethrough, a hypotenuse or second surface opposite the largest or second of the prism angles for selectively reflecting and transmitting light images impinging thereon, and a third surface opposite the third angle for reflecting light images impinging thereon, a first prism of said pair arranged for receiving at its entry-exit surface a light image traveling along said first optical axis, said received image then being internally reflected from said hypotenuse surface and said third surface, respectively, prior to being transmitted through said hypotenuse surface onto said mirror, said first prism being further arranged such that the angle of incidence of said light image at said hypotenuse surface is greater than the critical angle when reflection of the image is required and less than the critical angle when transmission is required, a second prism of said pair being arranged with its entry-exit face parallel to said entry-exit face of said first prism and further arranged such that its hypotenuse surfacee intersects said light image reflected from said mirror and then, subsequent to internally reflecting said light image from said third surface and said hypotenuse surface, respectively, said light image is transmitted through said entry-exit face of said second prism along a second optical axis parallel to said first optical axis; and means for selectively positioning one of said first and second prisms along a first line which makes an angle with said second optical axis which angle is equivalent to the third prism angle thereby changing the path length of said light image through said optical apparatus.

Claim 10

Optical apparatus for selectively controlling the transmission of a light image therethrough comprising: a mirror having its reflecting surface parallel to a first optical axis of said apparatus; a pair of similar prisms each having substantialy the same angular construction, an entry-exit or first surface opposite the smallest or first of the three prism angles for transmitting light images therethrough, a hypotenuse or second surface opposite the largest or second of the prism angles for selectively reflecting and transmitting light images impinging thereon, and a third surface opposite the third angle for reflecting light images impinging thereon, a first prism of said pair arranged for receiving at its entry-exit surface a light image traveling along said first optical axis, said received image then being internally reflected from said hypotenuse surface and said third surface, respectively, prior to being transmitted through said hypotenuse surface onto said mirror, said first prism being further arranged such that the angle of incidence of said light image at said hypotenuse surface is greater than the critical angle when reflection of the image is required and less than the critical angle when transmission is required, a second prism of said pair being arranged with its entry-exit face parallel to said entry-exit face of said first prism and further arranged such that its hypotenuse surfacee intersects said light image reflected from said mirror and then, subsequent to internally reflecting said light image from said third surface and said hypotenuse surface, respectively, said light image is transmitted through said entry-exit face of said second prism along a second optical axis parallel to said first optical axis; and means for selectively positioning one of said first and second prisms along a first line which makes an angle with said second optical axis which angle is equivalent to the third prism angle thereby changing the path length of said light image through said optical apparatus.

Claim 11

The invention according to claim 8 and further including means to rotate said first and second prisms and said mirror about one of said optical axes while maintaining their relative positions.

Claim 12

The invention according to claim 8 and further including means to selectively position one of said prisms along a second line perpendicular to said first line whereby the offset of said second axis from a projection of said first axis may be controlled.

Claim 13

The invention according to claim 1 wherein said pair of similar prisms is a pair of similar right angle prisms.

Claim 14

The invention according to claim 1 wherein said pair of similar prisms is a pair of 30*-60*-90* prisms.

Claim 15

Optical apparatus for selectively controlling the transmission of a light image therethrough comprising: a pair of similar prisms each having substantially the same angular construction, an entry-exit or first surface opposite the smallest or first of the three prism angles for transmitting light images therethrough, a hypotenuse or second surface opposite the largest or second of the three prism angles for selectively reflecting and transmitting light images impinging thereon, and a third surface opposite the third angle for reflecting light images impinging therEon, a first prism of said pair arranged for receiving at its entry-exit surface a light image traveling along a first optical axis of said apparatus, said received image being internally reflected from said hypotenuse surface and said third surface, respectively, prior to being transmitted through said hypotenuse surface, said first prism being further arranged such that the angle of incidence of said light image at said hypotenuse surface is greater than the critical angle when reflection of the image is required and less than the critical angle when transmission is required, a second prism of said pair being arranged so that its hypotenuse surface is parallel and adjacent to the hypotenuse surface of said first prism for receiving said light image from said first prism and then, subsequent to internally reflecting said light image from said third surface and said hypotenuse surface, respectively, transmitting said light image through said entry-exit face of said second prism along a second optical axis parallel to said first optical axis; and means for selectively positioning one of said first and second prisms along a first line which makes an angle with said second optical axis, which angle is equivalent to the third prism angle plue 90*, to change the offset of said second axis with respect to a projection of said first axis.

Claim 16

Optical apparatus for selectively controlling the transmission of a light image therethrough comprising: a pair of similar prisms each having substantially the same angular construction, an entry-exit or first surface opposite the smallest or first of the three prism angles for transmitting light images therethrough, a hypotenuse or second surface opposite the largest or second of the three prism angles for selectively reflecting and transmitting light images impinging thereon, and a third surface opposite the third angle for reflecting light images impinging therEon, a first prism of said pair arranged for receiving at its entry-exit surface a light image traveling along a first optical axis of said apparatus, said received image being internally reflected from said hypotenuse surface and said third surface, respectively, prior to being transmitted through said hypotenuse surface, said first prism being further arranged such that the angle of incidence of said light image at said hypotenuse surface is greater than the critical angle when reflection of the image is required and less than the critical angle when transmission is required, a second prism of said pair being arranged so that its hypotenuse surface is parallel and adjacent to the hypotenuse surface of said first prism for receiving said light image from said first prism and then, subsequent to internally reflecting said light image from said third surface and said hypotenuse surface, respectively, transmitting said light image through said entry-exit face of said second prism along a second optical axis parallel to said first optical axis; and means for selectively positioning one of said first and second prisms along a first line which makes an angle with said second optical axis, which angle is equivalent to the third prism angle plue 90*, to change the offset of said second axis with respect to a projection of said first axis.

Claim 17

The invention according to claim 8 wherein said pair of similar prisms is a pair of similar right angle prisms.

Claim 18

The invention according to claim 8 wherein said pair of similar prisms is a pair of 30*-60*-90* prisms.

Claim 19

Optical apparatus for selectively controlling the transmission of a light image therethrough comprising: a mirror having its reflecting surface parallel to a first optical axis of said apparatus; a pair of similar prisms each having substantially the same angular construction, an entry-exit or first surface opposite the smallest or first of the three prism angles for transmitting light images therethrough, a hypotenuse or second surface opposite the largest or second of the prism angles for selectively reflecting and transmitting light images impinging thereon, and a third surface opposite the third angle for reflecting light images impinging thereon, a first prism of said pair arranged for receiving at its entry-exit surface a light image traveling along said first optical axis, said received image then being internally reflected from said hypotenuse surface and said third surface, respectively, prior to being transmitted through said hypotenuse surface onto said mirror, said first prism being further arranged such that the angle of incidence of said light image at said hypotenuse surface is greater than the critical angle when reflection of the image is required and less than the critical angle when transmission is required, a second prism of said pair being arranged with its entry-exit face parallel to said entry-exit face of said first prism and further arranged such that its hypotenuse surface intersects said light image reflected from said mirror and then, subsequent to internally reflecting said light image from said third surface and said hypotenuse surface, respectively, said light image is transmitted through said entry-exit face of said second prism along a second optical axis parallel to said first optical axis; and means for selectively positioning one of said first and second prisms along a first line which makes an angle with said second optical axis which angle is equivalent to the third prism angle plus 90*, to change the offset of said second axis with respect to a projection of said first axis.

Claim 20

Optical apparatus for selectively controlling the transmission of a light image therethrough comprising: a mirror having its reflecting surface parallel to a first optical axis of said apparatus; a pair of similar prisms each having substantially the same angular construction, an entry-exit or first surface opposite the smallest or first of the three prism angles for transmitting light images therethrough, a hypotenuse or second surface opposite the largest or second of the prism angles for selectively reflecting and transmitting light images impinging thereon, and a third surface opposite the third angle for reflecting light images impinging thereon, a first prism of said pair arranged for receiving at its entry-exit surface a light image traveling along said first optical axis, said received image then being internally reflected from said hypotenuse surface and said third surface, respectively, prior to being transmitted through said hypotenuse surface onto said mirror, said first prism being further arranged such that the angle of incidence of said light image at said hypotenuse surface is greater than the critical angle when reflection of the image is required and less than the critical angle when transmission is required, a second prism of said pair being arranged with its entry-exit face parallel to said entry-exit face of said first prism and further arranged such that its hypotenuse surface intersects said light image reflected from said mirror and then, subsequent to internally reflecting said light image from said third surface and said hypotenuse surface, respectively, said light image is transmitted through said entry-exit face of said second prism along a second optical axis parallel to said first optical axis; and means for selectively positioning one of said first and second prisms along a first line which makes an angle with said second optical axis which angle is equivalent to the third prism angle plus 90*, to change the offset of said second axis with respect to a projection of said first axis.