Image-taking lens unit

An image-taking lens unit comprising:

• a variable-focal-length image-taking lens system that forms an optical image of an object at a variable magnification;
• and
• an image sensor that receives the optical image in a rectangular image-sensing region and converts the optical image into an electrical signal,
• wherein, of lens elements constituting the image-taking lens system, a most image-side lens element called a last lens element is given a non-circular outer shape fulfilling conditional formula (1) below, and
• wherein the image-taking lens system includes a reflective optical element that bends an optical path, and fulfils conditional formula (3) below:
• 1<TL/TS (1)
• 3≦ft/fw (3)
• where
• TS represents a maximum outer dimension in a direction parallel to shorter sides of the image-sensing region;
• TL represents a maximum outer dimension in a direction parallel to longer sides of the image-sensing region;
• fw represents a focal length of the entire image-taking lens system at a wide-angle end;
• and
• ft represents a focal length of the entire image-taking lens system at a telephoto end,
• wherein conditional formula (1a) below is fulfilled:
• b 4/3<TL/TStm (1a)
• and wherein conditional formula (2) below is fulfilled:
• 4≦LD ·FN/LB (2)
• where
• LD represents a diagonal length of the image-sensing region;
• FN represents an f-number of the image-taking lens system (a minimum value of the f-number in a case where the f-number varies);
• and
• LB represents an air-equivalent distance from a vertex of an image-side surface of the last lens element to an image surface (a maximum value of the distance in a case where the distance varies).

An image-taking apparatus comprising an image-taking lens unit, the image-taking lens unit comprising:

• an image-taking lens system that forms an optical image of an object;
• and
• an image sensor that receives the optical image in a rectangular image-sensing region and converts the optical image into an electrical signal,
• wherein the image-taking lens system includes a reflective optical element that bends an optical path, and
• wherein, of lens elements constituting the image-taking lens system, a most image-side lens element called a last lens element is molded of resin, and is given a non-circular outer shape fulfilling conditional formula (1) below:
• 1<TL/TStm (1)
• where
• TS represents a maximum outer dimension in a direction parallel to shorter sides of the image-sensing region;
• and
• TL represents a maximum outer dimension in a direction parallel to longer sides of the image-sensing region,
• wherein conditional formula (1a) below is fulfilled:
• 4/3<TL/TS (1a)
• wherein conditional formula (2) below is fulfilled:
• 4≦LD·FN/LB (2)
• where
• LD represents a diagonal length of the image-sensing region;
• FN represents an f-number of the image-taking lens system (a minimum value of the f-number in a case where the f-number varies);
• and
• LB represents an air-equivalent distance from a vertex of an image-side surface of
• the last lens element to an image surface (a maximum value of the distance in a case where the distance varies).

An image-taking apparatus comprising an image-taking lens unit, the image-taking lens unit comprising:

• a variable-focal-length image-taking lens system that forms an optical image of an object at a variable magnification;
• and
• an image sensor that receives the optical image in a rectangular image-sensing region and converts the optical image into an electrical signal,
• wherein, of lens elements constituting the image-taking lens system, a most image-side lens element called a last lens element is given a non-circular outer shape fulfilling conditional formula (1) below, and
• wherein the image-taking lens system includes a reflective optical element that bends an optical path, and fulfils conditional formula (3) below:
• 1<TL/TS (1)
• 3≦ft/fw (3)
• where
• TS represents a maximum outer dimension in a direction parallel to shorter sides of the image-sensing region;
• TL represents a maximum outer dimension in a direction parallel to longer sides of the image-sensing region;
• fw represents a focal length of the entire image-taking lens system at a wide-angle end;
• and
• ft represents a focal length of the entire image-taking lens system at a telephoto end wherein conditional formula (1a) below is fulfilled:
• 4/3<TL/TS (1a)
• and wherein conditional formula (2) below is fulfilled:
• 4≦LD·FN/LB (2)
• where
• LD represents a diagonal length of the image-sensing region;
• FN represents an f-number of the image-taking lens system (a minimum value of the f-number in a case where the f-number varies);
• and
• LB represents an air-equivalent distance from a vertex of an image-side surface of the last lens element to an image surface (a maximum value of the distance in a case where the distance varies).