Illumination device and imaging device for imaging skin of a human body

An imaging device for imaging skin of a human body as a target, the imaging device comprising:

• an illumination device;
• and
• an imager,
• wherein:
• the imager comprises:
• an image sensor configured to image a target;
• and
• an imaging lens configured to form an image of the target on the image sensor,
• the illumination device comprises:
• a first objective cover comprising a first light transmissive member having a first predetermined area, the first objective cover being configured to direct light reflected from the target and incident on a front surface of the first objective cover to the imaging lens, the image of the target being formed on the image sensor based on the reflected light received through the first objective cover, and the front surface of the first objective cover being orthogonal to an optical axis of the imager;
• a second objective cover comprising a second light transmissive member having a second predetermined area smaller than the first predetermined area, the second objective cover directing reflected light reflected from the target and incident on a front surface of the second objective cover to the imaging lens, the image of the target being formed on the image sensor based on the reflected light received through the second objective cover, the front surface of the second objective cover being orthogonal to the optical axis of the imager, and the second objective cover being selectively usable with the first objective cover;
• at least one first light source to illuminate the target through the first objective cover;
• and
• at least one second light source to illuminate the target through the second objective cover,
• the first objective cover is provided on a first cover included in the illumination device, the first cover being cylindrical,
• the second objective cover is provided on a second cover, the second cover being cylindrical and including an attachment and detachment part by which the second cover is selectively attachable to and detachable from the illumination device,
• the first objective cover is used as the objective cover to be in contact with the target, in a state in which the second cover is detached from the illumination device,
• the second objective cover is used as the objective cover to be in contact with the target, in a state in which the second cover is attached to the illumination device by the attachment and detachment part and is covering the first cover,
• in the state in which the second cover is detached from the illumination device and the first objective cover is in contact with the target, (i) a first region is defined outside the illumination device on a target side of the first objective cover, a sectional shape of the first region being bounded by outermost light rays among light rays included in the reflected light incident on the first objective cover and in focus with the imaging lens, and (ii) a second region is defined inside the illumination device on an imager side of the first objective cover, such that a sectional shape of the second region and the sectional shape of the first region are symmetrical with respect to the front surface of the first objective cover as an axis of symmetry,
• in the state in which the second cover is attached to the illumination device and the second objective cover is in contact with the target, (i) the first region is defined outside the illumination device on a target side of the second objective cover, a sectional shape of the first region being bounded by outermost light rays among light rays included in the reflected light incident on the second objective cover and in focus with the imaging lens, and (ii) the second region is defined inside the illumination device on an imager side of the second objective cover, such that a sectional shape of the second region and the sectional shape of the first region are symmetrical with respect to the front surface of the second objective cover as an axis of symmetry,
• the at least one first light source is located outside the second region as defined with respect to the first objective cover in the state in which the second objective cover is detached from the illumination device and the first objective cover is in contact with the target, and
• the at least one second light source is located outside the second region as defined with respect to the second objective cover in the state in which the second objective cover is attached to the illumination device and the second objective cover is in contact with the target.

An imaging device comprising:

• an illumination device;
• and
• an imager,
• the imager comprising:
• an image sensor configured to image a target;
• and
• an imaging lens configured to form an image of the target on the image sensor, and
• the illumination device comprising:
• a first objective cover comprising a first light transmissive member having a first predetermined area, the first objective cover being configured to direct light reflected from the target and incident on a front surface of the first objective cover to the imaging lens, the image of the target being formed on the image sensor based on the reflected light received through the first objective cover, and the front surface of the first objective cover being orthogonal to an optical axis of the imager;
• a second objective cover comprising a second light transmissive member having a second predetermined area smaller than the first predetermined area, the second objective cover directing reflected light reflected from the target and incident on a front surface of the second objective cover to the imaging lens, the image of the target being formed on the image sensor based on the reflected light received through the second objective cover, the front surface of the second objective cover being orthogonal to the optical axis of the imager, and the second objective cover being selectively usable with the first objective cover;
• a first light source configured to illuminate the target through the first objective cover;
• and
• a second light source configured to illuminate the target through the second objective cover,
• wherein:
• in a state in which the first objective cover is in contact with the target, (i) a first region is defined outside the illumination device on a target side of the first objective cover, a sectional shape of the first region being bounded by outermost light rays among light rays included in the reflected light incident on the first objective cover and in focus with the imaging lens, and (ii) a second region is defined inside the illumination device on an imager side of the first objective cover, such that a sectional shape of the second region and the sectional shape of the first region are symmetrical with respect to the front surface of the first objective cover as an axis of symmetry,
• in a state in which the second objective cover is in contact with the target, (i) the first region is defined outside the illumination device on a target side of the second objective cover, a sectional shape of the first region being bounded by outermost light rays among light rays included in the reflected light incident on the second objective cover and in focus with the imaging lens, and (ii) the second region is defined inside the illumination device on an imager side of the second objective cover, such that a sectional shape of the second region and the sectional shape of the first region are symmetrical with respect to the front surface of the second objective cover as an axis of symmetry,
• the first light source is located outside the second region as defined with respect to the first objective cover in the state in which the first objective cover is in contact with the target, and
• the second light source is located outside the second region as defined with respect to the second objective cover in the state in which the second objective cover is in contact with the target.