Improved coaxial examination of surfaces

• Main Authors: Martin Wayne Millington, Peter Martin Hallett, Jordan Dean Pearce, Roberto Stefano Pasquale King
• Format: Patent
• Language: English
• Published: 08.02.2023
• Subjects: ACCESSORIES THEREFOR; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USINGWAVES OTHER THAN OPTICAL WAVES; APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FORPROJECTING OR VIEWING THEM; CALCULATING; CINEMATOGRAPHY; COMPUTING; COUNTING; ELECTRIC DIGITAL DATA PROCESSING; ELECTROGRAPHY; HOLOGRAPHY; PHOTOGRAPHY; PHYSICS

A coaxial lighting and image acquisition apparatus (200) for acquiring an image, perhaps of a fingerprint, from a surface (150), the apparatus including: a camera (140) having an optical axis; a beam splitter (110); an incident light source (230); and control means (260) for moving the incident light source axially relative to the beam splitter (110). The incident light source may include a diffuser (135) and multiple separate light sources, such as LEDs (230). The light may illuminate the surface from at least two angles (120) relative to the camera optical axis. There may be a controller (260) to select which discrete light source illuminates. The image may be stored together with the position of the incident light source, perhaps by having that information embedded in the image captured by the camera. Alternatively, the angle of incident light may be embedded in the image captured by the camera. The embedded information may be visibly indicated in the image. More than one image may be captured, at least one of which may have illumination off axis from that of the camera axis (145). There may be a frame extending from the camera to position it a fixed distance from the surface.