Filter switching device, photographing lens, camera, and image pickup system

A photographing lens for a camera, comprising:

• an optical filter unit that is disposed on an optical path of an object light that passes through the photographing lens, and can be switched to any one of a plurality of spectral transmittances;
• a spectral transmittance switching unit that switches a spectral transmittance of the optical filter unit to one of the plurality of spectral transmittances;
• a filter spectral transmittance information storage unit that stores filter spectral transmittance information, which is information relating to each of the plurality of spectral transmittances;
• a lens spectral transmittance information storage unit that stores lens spectral transmittance information, which is information relating to a spectral transmittance of the photographing lens;
• and
• a lens information output unit that outputs lens information including the lens spectral transmittance information and the filter spectral transmittance information corresponding to the spectral transmittance of the optical filter unit to the camera to which the photographing lens is attached when the spectral transmittance of the optical filter unit is switched.

A photographing lens for a camera, comprising:

• an optical filter unit that is disposed on an optical path of an object light that passes through the photographing lens, and can be switched to any one of a plurality of spectral transmittances;
• a spectral transmittance switching unit that switches a spectral transmittance of the optical filter unit to one of the plurality of spectral transmittances;
• a lens total spectral transmittance information storage unit that stores lens total spectral transmittance information, which is information relating to a lens total spectral transmittance obtained by adding a spectral transmittance of the photographing lens to each of the plurality of spectral transmittances;
• and
• a lens information output unit that outputs lens information including the lens total spectral transmittance information corresponding to the spectral transmittance of the optical filter unit to the camera to which the photographing lens is attached when the spectral transmittance of the optical filter unit is switched.

A filter switching device comprising:

• an optical filter unit that is disposed on an optical path of light emitted from an illumination light source for illuminating an object to be photographed by a camera toward the object, and can be switched to any one of a plurality of spectral transmittances;
• a spectral transmittance switching unit that switches a spectral transmittance of the optical filter unit to a spectral transmittance selected from the plurality of spectral transmittances;
• a filter spectral transmittance information storage unit that stores filter spectral transmittance information, which is information relating to each of the plurality of spectral transmittances;
• and
• a filter spectral transmittance information output unit that outputs filter spectral transmittance information corresponding to the selected spectral transmittance to the camera.

An image pickup system comprising a camera, an illumination light source for illuminating an object to be photographed by the camera, and a filter switching device constituted to be capable of varying a spectral characteristic of illumination light emitted from the illumination light source toward the object by switching a spectral transmittance of an optical filter unit that is disposed on an optical path of the illumination light emitted toward the object and can be switched to any one of a plurality of spectral transmittances,

• wherein the filter switching device comprises:
• a spectral transmittance switching unit that switches the spectral transmittance of the optical filter unit to a spectral transmittance selected from the plurality of spectral transmittances;
• a filter spectral transmittance information storage unit that stores filter spectral transmittance information, which is information relating to each of the plurality of spectral transmittances;
• and
• a filter spectral transmittance information output unit that outputs filter spectral transmittance information corresponding to the selected spectral transmittance to the camera,
• the camera comprises:
• a filter spectral transmittance information input unit that receives the filter spectral transmittance information output from the filter spectral transmittance information storage unit;
• an image pickup unit capable of generating an image signal having at least three bands from an object image formed by a photographing lens;
• an image data processing unit that generates image data by processing the image signal generated by the image pickup unit;
• and
• a spectral transmittance switch command signal output unit that outputs a signal specifying one of the plurality of spectral transmittances that can be switched by the optical filter unit to the filter switching device, and
• the image data processing unit generates image data having a larger number of bands than a number of bands included in an image signal generated by the image pickup unit in a single image pickup operation on the basis of a plurality of the image signals having at least three bands, which are obtained by the image pickup unit through image pickup operations performed every time the spectral transmittance of the optical filter unit is switched, and the filter spectral transmittance information included in the filter spectral transmittance information input from the filter switching unit.