Image capturing device, color measuring device, color measuring system, and image forming apparatus

An image capturing device comprising:

• an image capturing unit that includes:
• an optical transmission member disposed on a surface facing a subject;
• and
• a sensor unit that captures an image of the subject via the optical transmission member;
• a moving unit that moves the image capturing unit in an optical axis direction of the sensor unit;
• and
• a determining unit that determines whether contaminations imaged in first and second images represent a contamination on the optical transmission member, based on a difference between at least one of a position and size of the contaminations imaged in the first and second images, the first image being captured by the sensor unit when the image capturing unit is located at a first position in the optical axis direction, and the second image being captured by the sensor unit when the image capturing unit is located at a second position spaced farther away from the subject than the first position in the optical axis direction.

An image forming apparatus comprising:

• an image forming unit that forms a subject on a sheet;
• an image capturing unit that includes:
• an optical transmission member disposed on a surface facing the subject;
• and
• a sensor unit that captures an image of the subject via the optical transmission member;
• a moving unit that moves the image capturing unit in an optical axis direction of the sensor unit;
• and
• a determining unit that determines whether contaminations imaged in first and second images represent a contamination on the optical transmission member, based on a difference between at least one of a position and size of the contaminations imaged in the first and second images, the first image being captured by the sensor unit when the image capturing unit is located at a first position in the optical axis direction, and the second image being captured by the sensor unit when the image capturing unit is located at a second position spaced farther away from the subject than the first position in the optical axis direction.

An image forming system comprising:

• an image forming unit that forms a subject on a sheet;
• an image capturing unit that includes:
• an optical transmission member disposed on a surface facing the subject;
• and
• a sensor unit that captures an image of the subject via the optical transmission member;
• a moving unit that moves the image capturing unit in an optical axis direction of the sensor unit;
• and
• a determining unit that determines whether contaminations imaged in first and second images represent a contamination on the optical transmission member, based on a difference between at least one of a position and size of the contaminations imaged on the first and second images, the first image being captures by the sensor unit when the image capturing unit is located at a first position in the optical axis direction, and the second image being captured by the sensor unit when the image capturing unit is located at a second position spaced farther away from the subject than the first position in the optical axis direction.