Zoom lens system

A zoom lens system for forming a final image of an object, said system having an object side and an image side and comprising in order from the object side to the image side:

• a zoom lens that forms an intermediate real image;
• and
• a variable focal length relay system that receives the intermediate real image and changes its magnification to form the final image;
• wherein the zoom lens system has a zoom ratio of at least 10 to 1.

A zoom lens system for forming a final image of an object, the zoom lens system having a range of focal lengths between a maximum focal length and a minimum focal length and forming at least a first intermediate real image between the object and the final image for all focal lengths within the range of focal lengths, the zoom lens system having an object side and an image side and comprising in order from the object side to the image side:

• a first lens unit having a focal length that is changed to change the size (magnification) of the first intermediate real image, the first lens unit being located between the object and the first intermediate real image;
• and
• a second lens unit for changing the size (magnification) of the final image, the second lens unit being located between the first intermediate real image and the final image;
• wherein the zoom lens system has a zoom ratio of at least 10 to 1.

A zoom lens system having an object side and an image side and comprising in order from the object side to the image side:

• a variable focal length lens unit that forms an intermediate real image of an object;
• and
• a variable focal length lens unit that forms a real image of the intermediate real image;
• wherein the zoom lens system has a zoom ratio of at least 10 to 1.

A zoom lens system for forming a final image of an object, said system having a variable focal length, an optical axis, an aperture stop, and a chief ray that crosses the optical axis at the aperture stop, said system comprising:

• two lens units for changing the focal length of the system and for forming the final image, one of the units having a variable focal length and the other unit having at least a portion that is moveable;
• wherein the chief ray crosses the optical axis at at least one other location besides said aperture stop for all focal lengths of the system;
• wherein the system forms an intermediate real image that is located between the two lens units for all focal lengths of the system;
• and
• wherein the zoom lens system has a zoom ratio of at least 10 to 1.

A zoom lens system comprising:

• a zoom kernel for forming an intermediate real image;
• and
• a zoom relay that zooms for magnifying the intermediate real image to form a final image;
• wherein the zoom lens system has a zoom ratio of at least 10 to 1.

A zoom lens system for forming a final image of an object, said system having an object side and an image side and forming a first intermediate real image between the object and the final image, said system comprising in order from the object side to the image side:

• a first optical unit including at least two lens elements and located between the object and the first intermediate real image, said unit comprising at least one optical subunit which is moved to change the size (magnification) of the first intermediate real image;
• and
• a second optical unit including at least two lens elements and located between the first intermediate real image and the final image, at least a portion of which is moved to change the size (magnification) of the final image;
• wherein the optical subunit whose movement serves as the primary source of magnification change for the first optical unit has a negative power.

A zoom lens system for forming a final image of an object, said system having an object side and an image side and comprising in order from the object side to the image side:

• a zoom lens that forms an intermediate real image;
• and
• a variable focal length relay system that receives the intermediate real image and changes its magnification to form the final image;
• wherein (i) the zoom lens that forms an intermediate real image comprises an optical unit which has a negative power and (ii) movement of said optical unit serves as the primary source of magnification change for said zoom lens that forms an intermediate real image.

A zoom lens system for forming a final image of an object, the zoom lens system having a range of focal lengths between a maximum focal length and a minimum focal length and forming at least a first intermediate real image between the object and the final image for all focal lengths within the range of focal lengths, the zoom lens system having an object side and an image side and comprising in order from the object side to the image side:

• a first lens unit having a focal length that is changed to change the size (magnification) of the first intermediate real image, the first lens unit being located between the object and the first intermediate real image;
• and
• a second lens unit for changing the size (magnification) of the final image, the second lens unit being located between the first intermediate real image and the final image;
• wherein (i) the first lens unit comprises an optical subunit which has a negative power and (ii) movement of said optical subunit serves as the primary source of magnification change for said first lens unit.

A zoom lens system having an object side and an image side and comprising in order from the object side to the image side:

• a variable focal length lens unit that forms an intermediate real image of an object;
• and
• a variable focal length lens unit that forms a real image of the intermediate real image;
• wherein (i) the variable focal length lens unit that forms the intermediate real image comprises an optical subunit which has a negative power and (ii) movement of said optical subunit serves as the primary source of magnification change for said variable focal length lens unit that forms the intermediate real image.

A zoom lens system for forming a final image of an object, said system having a variable focal length, an optical axis, an aperture stop, and a chief ray that crosses the optical axis at the aperture stop, said system comprising:

• two lens units for changing the focal length of the system and for forming the final image, one of the units having a variable focal length and the other unit having at least a portion that is moveable;
• wherein the chief ray crosses the optical axis at at least one other location besides said aperture stop for all focal lengths of the system;
• wherein the system forms an intermediate real image that is located between the two lens units for all focal lengths of the system;
• and
• wherein (i) the unit that has a variable focal length comprises an optical subunit which has a negative power and (ii) movement of said optical subunit serves as the primary source of magnification change for said lens unit that has a variable focal length.

A zoom lens system comprising:

• a zoom kernel for forming an intermediate real image;
• and
• a zoom relay that zooms for magnifying the intermediate real image to form a final image;
• wherein (i) the zoom kernel comprises an optical unit which has a negative power and (ii) movement of said optical unit serves as the primary source of magnification change for said zoom kernel.