Zoom lens system, imaging device and camera

An imaging device capable of outputting an optical image of an object as an electric image signal, comprising:

• a zoom lens system that forms the optical image of the object;
• and
• an image sensor that converts the optical image formed by the zoom lens system into the electric image signal, wherein
• in the zoom lens system,
• the system, in order from the object side to the image side, comprises a first lens unit having negative optical power, a second lens unit having positive optical power and a third lens unit having positive optical power, wherein
• the first lens unit, in order from the object side to the image side, consists of a first lens element that has a concave surface at least on the image side and that has negative optical power and a second lens element that has a convex surface at least on the object side and that has positive optical power,
• the second lens unit, in order from the object side to the image side, comprises a cemented lens element fabricated by cementing a third lens element and a fourth lens element having optical power of mutually different signs, and a fifth lens element being one single lens element,
• in zooming from a wide-angle limit to a telephoto limit, all of the first lens unit, the second lens unit and the third lens unit move along an optical axis, and
• the following conditions (1) and (I-2) are satisfied:
• 5.0<αiw<20.0 (1)
• n11≧1.9 (I-2)
• (wherein, 3.2<fT/fW and ωW>35)
• where,
• αiW is an incident angle of a principal ray to an image sensor at a maximum image height at a wide-angle limit (defined as positive when the principal ray is incident on a light acceptance surface of the image sensor in a state of departing from the optical axis),
• n11 is a refractive index of the first lens element to the d-line,
• ωW is a half view angle (°) at a wide-angle limit,
• fT is a focal length of the entire system at a telephoto limit, and
• fW is a focal length of the entire system at a wide-angle limit.

A camera for converting an optical image of an object into an electric image signal and then performing at least one of displaying and storing of the converted image signal, comprising

• an imaging device having a zoom lens system that forms the optical image of the object and an image sensor that converts the optical image formed by the zoom lens system into the electric image signal, wherein
• in the zoom lens system,
• the system, in order from the object side to the image side, comprises a first lens unit having negative optical power, a second lens unit having positive optical power and a third lens unit having positive optical power, wherein
• the first lens unit, in order from the object side to the image side, consists of a first lens element that has a concave surface at least on the image side and that has negative optical power and a second lens element that has a convex surface at least on the object side and that has positive optical power,
• the second lens unit, in order from the object side to the image side, comprises a cemented lens element fabricated by cementing a third lens element and a fourth lens element having optical power of mutually different signs, and a fifth lens element being one single lens element,
• in zooming from a wide-angle limit to a telephoto limit, all of the first lens unit, the second lens unit and the third lens unit move along an optical axis, and
• the following conditions (1) and (I-2) are satisfied:
• 5.0<αiW<20.0 (1)
• n11≧1.9 (I-2)
• (wherein, 3.2<fT/fW and ωW>35)
• where,
• αiW is an incident angle of a principal ray to an image sensor at a maximum image height at a wide-angle limit (defined as positive when the principal ray is incident on a light acceptance surface of the image sensor in a state of departing from the optical axis),
• n11 is a refractive index of the first lens element to the d-line,
• ωW is a half view angle (°) at a wide-angle limit,
• fT is a focal length of the entire system at a telephoto limit, and
• fW is a focal length of the entire system at a wide-angle limit.

A zoom lens system, in order from the object side to the image side, comprising a first lens unit having negative optical power, a second lens unit having positive optical power and a third lens unit having positive optical power, wherein

• the first lens unit, in order from the object side to the image side, consists of a first lens element that has a concave surface at least on the image side and that has negative optical power and a second lens element that has a convex surface at least on the object side and that has positive optical power,
• the second lens unit, in order from the object side to the image side, comprises a cemented lens element fabricated by cementing a third lens element and a fourth lens element having optical power of mutually different signs, and a fifth lens element being one single lens element,
• in zooming from a wide-angle limit to a telephoto limit, all of the first lens unit, the second lens unit and the third lens unit move along an optical axis, and
• the following conditions (1) and (II-2) are satisfied:
• 5.0<αiW<20.0 (1)
• (n11−1)·(n12−1)≧0.84 (II-2)
• (wherein, 3.2<fT/fW and ωW>35)
• where,
• αiW is an incident angle of a principal ray to an image sensor at a maximum image height at a wide-angle limit (defined as positive when the principal ray is incident on a light acceptance surface of the image sensor in a state of departing from the optical axis),
• n11 is a refractive index of the first lens element to the d-line,
• n12 is a refractive index of the second lens element to the d-line,
• ωW is a half view angle (°) at a wide-angle limit,
• fT is a focal length of the entire system at a telephoto limit, and
• fW is a focal length of the entire system at a wide-angle limit.

An imaging device capable of outputting an optical image of an object as an electric image signal, comprising:

• a zoom lens system that forms the optical image of the object;
• and
• an image sensor that converts the optical image formed by the zoom lens system into the electric image signal, wherein
• in the zoom lens system,
• the system, in order from the object side to the image side, comprises a first lens unit having negative optical power, a second lens unit having positive optical power and a third lens unit having positive optical power, wherein
• the first lens unit, in order from the object side to the image side, consists of a first lens element that has a concave surface at least on the image side and that has negative optical power and a second lens element that has a convex surface at least on the object side and that has positive optical power,
• the second lens unit, in order from the object side to the image side, comprises a cemented lens element fabricated by cementing a third lens element and a fourth lens element having optical power of mutually different signs, and a fifth lens element being one single lens element,
• in zooming from a wide-angle limit to a telephoto limit, all of the first lens unit, the second lens unit and the third lens unit move along an optical axis, and
• the following conditions (1) and (II-2) are satisfied:
• 5.0<αiW<20.0 (1)
• (n11−1)·(n12−1)≧0.84 (II-2)
• (wherein, 3.2<fT/fW and ωW>35)
• where,
• αiW is an incident angle of a principal ray to an image sensor at a maximum image height at a wide-angle limit (defined as positive when the principal ray is incident on a light acceptance surface of the image sensor in a state of departing from the optical axis),
• n11 is a refractive index of the first lens element to the d-line,
• n12 is a refractive index of the second lens element to the d-line,
• ωW is a half view angle (°) at a wide-angle limit,
• fT is a focal length of the entire system at a telephoto limit, and
• fW is a focal length of the entire system at a wide-angle limit.

A camera for converting an optical image of an object into an electric image signal and then performing at least one of displaying and storing of the converted image signal, comprising

• an imaging device having a zoom lens system that forms the optical image of the object and an image sensor that converts the optical image formed by the zoom lens system into the electric image signal, wherein
• in the zoom lens system,
• the system, in order from the object side to the image side, comprises a first lens unit having negative optical power, a second lens unit having positive optical power and a third lens unit having positive optical power, wherein
• the first lens unit, in order from the object side to the image side, consists of a first lens element that has a concave surface at least on the image side and that has negative optical power and a second lens element that has a convex surface at least on the object side and that has positive optical power,
• the second lens unit, in order from the object side to the image side, comprises a cemented lens element fabricated by cementing a third lens element and a fourth lens element having optical power of mutually different signs, and a fifth lens element being one single lens element,
• in zooming from a wide-angle limit to a telephoto limit, all of the first lens unit, the second lens unit and the third lens unit move along an optical axis, and
• the following conditions (1) and (II-2) are satisfied:
• 5.0<αiW<20.0 (1)
• (n11−1(·(n12−1)≧0.84 (II-2)
• (wherein, 3.2<fT/fW and ωW>35)
• where,
• αiW is an incident angle of a principal ray to an image sensor at a maximum image height at a wide-angle limit (defined as positive when the principal ray is incident on a light acceptance surface of the image sensor in a state of departing from the optical axis),
• n11 is a refractive index of the first lens element to the d-line,
• n12 is a refractive index of the second lens element to the d-line,
• ωW is a half view angle (°) at a wide-angle limit,
• fT is a focal length of the entire system at a telephoto limit, and
• fW is a focal length of the entire system at a wide-angle limit.

A zoom lens system, in order from the object side to the image side, comprising a first lens unit having negative optical power, a second lens unit having positive optical power and a third lens unit having positive optical power, wherein

• the first lens unit, in order from the object side to the image side, consists of a first lens element that has a concave surface at least on the image side and that has negative optical power and a second lens element that has a convex surface at least on the object side and that has positive optical power,
• the second lens unit, in order from the object side to the image side, comprises a cemented lens element fabricated by cementing a third lens element and a fourth lens element having optical power of mutually different signs, and a fifth lens element being one single lens element,
• in zooming from a wide-angle limit to a telephoto limit, all of the first lens unit, the second lens unit and the third lens unit move along an optical axis, and
• the following conditions (1) and (III-2) are satisfied:
• 5.0<αiW<20.0 (1)
• n12≧2.0 (III-2)
• (wherein, 3.2<fT/fW and ωW>35)
• where,
• αiW is an incident angle of a principal ray to an image sensor at a maximum image height at a wide-angle limit (defined as positive when the principal ray is incident on a light acceptance surface of the image sensor in a state of departing from the optical axis),
• n12 is a refractive index of the second lens element to the d-line,
• ωW is a half view angle (°) at a wide-angle limit,
• fT is a focal length of the entire system at a telephoto limit, and
• fW is a focal length of the entire system at a wide-angle limit.

An imaging device capable of outputting an optical image of an object as an electric image signal, comprising:

• a zoom lens system that forms the optical image of the object;
• and
• an image sensor that converts the optical image formed by the zoom lens system into the electric image signal, wherein
• in the zoom lens system,
• the system, in order from the object side to the image side, comprises a first lens unit having negative optical power, a second lens unit having positive optical power and a third lens unit having positive optical power, wherein
• the first lens unit, in order from the object side to the image side, consists of a first lens element that has a concave surface at least on the image side and that has negative optical power and a second lens element that has a convex surface at least on the object side and that has positive optical power,
• the second lens unit, in order from the object side to the image side, comprises a cemented lens element fabricated by cementing a third lens element and a fourth lens element having optical power of mutually different signs, and a fifth lens element being one single lens element,
• in zooming from a wide-angle limit to a telephoto limit, all of the first lens unit, the second lens unit and the third lens unit move along an optical axis, and
• the following conditions (1) and (III-2) are satisfied:
• 5.0<αiW<20.0 (1)
• n12≧2.0 (III-2)
• (wherein, 3.2<fT/fW and ωW>35)
• where,
• αiW is an incident angle of a principal ray to an image sensor at a maximum image height at a wide-angle limit (defined as positive when the principal ray is incident on a light acceptance surface of the image sensor in a state of departing from the optical axis),
• n12 is a refractive index of the second lens element to the d-line,
• ωW is a half view angle (°) at a wide-angle limit,
• fT is a focal length of the entire system at a telephoto limit, and
• fW is a focal length of the entire system at a wide-angle limit.

A camera for converting an optical image of an object into an electric image signal and then performing at least one of displaying and storing of the converted image signal, comprising

• an imaging device having a zoom lens system that forms the optical image of the object and an image sensor that converts the optical image formed by the zoom lens system into the electric image signal, wherein
• in the zoom lens system,
• the system, in order from the object side to the image side, comprises a first lens unit having negative optical power, a second lens unit having positive optical power and a third lens unit having positive optical power, wherein
• the first lens unit, in order from the object side to the image side, consists of a first lens element that has a concave surface at least on the image side and that has negative optical power and a second lens element that has a convex surface at least on the object side and that has positive optical power,
• the second lens unit, in order from the object side to the image side, comprises a cemented lens element fabricated by cementing a third lens element and a fourth lens element having optical power of mutually different signs, and a fifth lens element being one single lens element,
• in zooming from a wide-angle limit to a telephoto limit, all of the first lens unit, the second lens unit and the third lens unit move along an optical axis, and
• the following conditions (1) and (III-2) are satisfied:
• 5.0<αiW<20.0 (1)
• n12≧2.0 (III-2)
• (wherein, 3.2<fT/fW and ωW>35)
• where,
• αiW is an incident angle of a principal ray to an image sensor at a maximum image height at a wide-angle limit (defined as positive when the principal ray is incident on a light acceptance surface of the image sensor in a state of departing from the optical axis),
• n12 is a refractive index of the second lens element to the d-line,
• ωW is a half view angle (°) at a wide-angle limit,
• fT is a focal length of the entire system at a telephoto limit, and
• fW is a focal length of the entire system at a wide-angle limit.