Variable power optical system, imaging apparatus, and digital apparatus

A variable power optical system that performs variable power by changing the distance between each lens group in an optical axis direction, comprising from an object side:

• a first lens group having a negative optical power;
• a second lens group having a positive optical power;
• and
• a third lens group having a positive optical power,
• wherein the distance between said first lens group and said second lens group is narrowed when performing variable power from wide-angle end to telephoto end, said first lens group includes a cemented lens and is configured by less than or equal to three lenses, the cemented lens is comprises from the object side a negative lens and a positive lens, said second lens group includes an aspherical surface, and said third lens group consists of one ore two lens.

An imaging apparatus comprising:

• imaging elements for converting an optical image to an electrical signal;
• and
• a variable power optical system that forms an optical image of the object on a receiving surface of said imaging elements and performs variable power by changing the distance between each lens group in an optical axis direction,
• wherein said optical system including from the object side:
• a first lens group including a cemented lens, configured by less than or equal to three lenses, including an aspherical surface and having a negative optical power as a whole;
• and
• a second lens group including an aspherical surface and having a positive optical power as a whole, and
• wherein the distance between said first lens group and said second lens group is narrowed when performing variable power from wide-angle end to telephoto end.

A digital apparatus comprising an imaging unit which includes imaging elements for converting an optical image to an electrical signal, and a variable power optical system that forms an optical image of the object on a receiving surface of said imaging elements and performs variable power by changing the distance between each lens group in an optical axis direction,

• wherein said optical system includes from the object side:
• a first lens group including a cemented lens, configured by less than or equal to three lenses, including an aspherical surface and having a negative optical power as a whole;
• and
• a second lens group including an aspherical surface and having a positive optical power as a whole, and
• wherein the distance between said first lens group and said second lens group is narrowed when performing variable power from wide-angle end to telephoto end.