Patent ID: 11889979
Assignee: BARCO N.V.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC A  G  H | IPC A  G  H

Claim 0:
1. A calibrated inspection unit for direct application to a skin surface of a patient, wherein a skin includes layers below the skin surface, said calibrated inspection unit comprising:
an optical array of elements in an optical path, said optical path comprising:
at least one light source,
an image capturing device configured to capture images and having a field of view,
a reference viewing surface through which the image capturing device is able to capture images,
an imaging lens having a radius of curvature and a focal length, wherein the imaging lens is configured to define a position of a focus point of the image capturing device that extends beyond the reference viewing surface along the optical path,
a fixed first calibration pattern located in a fixed position with respect to the reference viewing surface and located external to the reference viewing surface for contacting the skin surface, the fixed first calibration pattern being located at the fixed position that is at a depth that corresponds to at least one layer of the layers of the skin below the skin surface,
wherein the image capturing device is configured to capture an image of the fixed first calibration pattern, as a first image, and the image capturing device is configured to capture an image of the skin below the skin surface, as a second image, and
a focusing means for changing the focus position along the optical path as a function of adjustment values,
the calibrated inspection unit further comprising:

a calibration defining a relationship between the adjustment values of the focusing means and the positions of focus points below the skin surface, the adjustment values including a first adjustment value for the position of the focus point of the image capturing device at the fixed position of the fixed first calibration pattern,
wherein the focusing means are provided by the imaging lens which is a liquid lens, and wherein the calibrated inspection unit is configured in a way such that the fixed first calibration pattern is configured to be used for focus calibration.