Zoom lens with differential focal compensation for visible, IR, and UV light

A zoom lens mechanism, comprising:

• a zoom lens barrel;
• a variable magnification lens part including a first cam pin, which is supported within said zoom lens barrel in such a manner to be movable forward and backward along an optical axis;
• a correction lens part including a second cam pin for correcting a focal inadequacy resulting from a movement of said variable magnification lens part, which is supported within said zoom lens barrel in such a manner to be movable forward and backward along an optical axis;
• a cylindrical cam supported within said zoom lens barrel in such a manner to be rotatable on said optical axis;
• a first cam groove for variable magnification formed on said cylindrical cam to be engaged with said first cam pin;
• a second cam groove for correction formed on said cylindrical cam to be engaged with said second cam pin, which has a first edge on one side of said second cam groove being formed to have a shape which corrects a focal inadequacy resulting from a movement of said variable magnification lens part in a wavelength area of visible light and a second edge facing said first edge being formed to have a shape which corrects focal inadequacy resulting from a movement of said variable magnification lens part in a wavelength area of infrared light;
• and
• switching means for selectively contacting said second cam pin of said correction lens part with said first edge or said second edge.

A zoom lens mechanism, comprising:

• a zoom lens barrel;
• a variable magnification lens part support within said zoom lens barrel in such a manner to be movable forward and backward along an optical axis;
• a correction lens part for correcting a focal inadequacy resulting from a movement of said variable magnification lens part, which is supported within a zoom lens barrel in such a manner to be movable forward and backward along an optical axis;
• first control means for controlling a movement of said correction lens part so as to correct focal inadequacy resulting from a movement of said variable magnification lens part in a wavelength area of visible light;
• second control means for controlling a movement of said correction lens part so as to correct a focal inadequacy resulting from a movement of said variable magnification lens part in a wavelength area of ultraviolet light;
• and
• switching means for selectively making said first control means or said second control means work.

A zoom lens mechanism, comprising:

• a zoom lens barrel;
• a variable magnification lens part including a first cam pin, which is supported within said zoom lens barrel in such a manner to be movable forward and backward along an optical axis;
• a correction lens part including a second cam pin for correcting a focal inadequacy resulting from a movement of said variable magnification lens part, which is supported within said zoom lens barrel in such a manner to be movable forward and backward along an optical axis;
• a cylindrical cam supported within said zoom lens barrel in such a manner to be rotatable on said optical axis;
• a first cam groove for variable magnification formed on said cylindrical cam to be engaged with said first cam pin;
• a second cam groove for correction formed on said cylindrical cam to be engaged with said second cam pin, which has an first edge on one side of said second cam groove being formed to have a shape which corrects a focal inadequacy resulting from a movement of said variable magnification lens part in a wavelength area of visible light and a second edge facing said first edge being formed to have a shape which corrects focal inadequacy resulting from a movement of said variable magnification lens part in a wavelength area of ultraviolet light;
• and
• switching means for selectively contacting said second cam pin of said correction lens part with said first edge or said second edge.