Planar light sources are directed at an article on either side of the optical axis so that the trace of each light beam defines a line, on either side of the optical axis, whose form is dependent on the shape of the surface of the article. To determine whether the article is in focus, the distance between the two lines is measured. To determine whether the article is in correct pitch, the distance between each line and the optical axis is measured and compared. To determine whether the article has drifted, the distances between the ends of the lines and the optical axis are measured and compared.
To image a surface of an object more efficiently using automatic positioning of the object with respect to the optical axis of a camera while keeping the surface of the object at a predetermined angular orientation with respect to the optical axis, a general shape of the object is first measured and a mathematical function approximating the surface is determined. Relative displacements and orientations for an imaging path are then calculated and the object is manipulated along the imaging path while being imaged with the surface of the object being at the predetermined angular orientation. The speed and accuracy of surface imaging is improved.
An apparatus and method for imaging fired bullets and/or cartridges for forensic examination, which facilitate mounting of the ammunition to be imaged. The apparatus comprises a mounting support including a fired bullet holding device and a fired cartridge holding device, a microscope, an illumination device and a mechanical device for selectively aligning the optical axis of the microscope with a bullet section or the longitudinal axis of the cartridge showing its head surface. The bullet holding device comprises a rotary member extending through a mounting support and ending with an adjustable bullet holder for maintaining the bullet in a desired angular orientation with respect to a transverse reference plane aligned with the optical axis of the microscope, while the rotary member is being rotated about its rotation axis to scan the imaged surface area. According to a preferred embodiment, the adjustable bullet holder includes a bullet mounting ball for attaching thereto the bullet and being received in a socket portion of the rotary member, and a retaining device for maintaining the mounting ball and the attached bullet in the desired angular orientation. The retaining device preferably comprises a magnetic source using ferromagnetic properties of the mounting ball to provide retaining thereof, while providing mechanical coupling for imparting rotation to the rotary member as desired. The apparatus and method according to the invention are particularly useful in connection with an automated ammunition examining system.
An Optical Probe Measurement Device accurately and efficiently measures locations of visible features of a structure without making contact with the structure. It employs a centering microscope which a user looks through to locate the feature to be measured. The centering microscope is connected to an orientation plate in a known pose which has targets measurable with a 3D measurement device. The 3D measurement device determines 3D locations of the targets. A light source is attached to the orientation plate to produce a light beam which intersects the optical axis at the focal point of the centering microscope, being a distance D.sub.0 away from the end of the centering microscope. When this light beam impinges on the surface of the structure at the same location as the feature seen in the centering microscope, the feature is exactly the D.sub.0 away from the centering microscope. A calculation device receives the measured 3D locations of the targets, the pose of the centering microscope relative to the orientation plate, and the distance D.sub.0, and calculates the actual 3D location of the focal point, also being the location of the feature on the structure. Optionally a triggering device may be used to indicate when to calculate the location of the focal point.
The apparatus has a fired cartridge mounting device for holding the cartridge substantially aligned with a longitudinal axis with a primer surface of the cartridge substantially perpendicular to the axis, a cartridge microscope mounted with its optical axis substantially parallel to the longitudinal axis, a focusing mechanism for focusing the microscope to image a breech face impression on the primer surface and a firing pin impression surface in the primer surface, and an axisymmetric light source mounted to project axially symmetric light onto the breech face impression and the firing pin impression surface about the longitudinal axis. Images of the breech face and the firing pin impressions can be used for comparative analysis independently of an angular orientation of the cartridge held by the mounting device. During this analysis, a first image from a test cartridge and a second image from a computer data bank are rotated relative to one another, and a maximum correlation value for the rotated first and second images is obtained.
The portable spent cartridge casing examination imaging apparatus has a carrying case in which all the necessary components for field imaging of spent cartridge casings are contained securely for transport when the case is closed, and can be solidly assembled in the field for imaging. The case includes a base, a lid which locks in a vertical open position. A spent cartridge casing mounting device is provided for holding the cartridge substantially aligned with a longitudinal axis with the primer surface of the cartridge being substantially perpendicular to the axis, and an imaging system consisting of a cartridge microscope, camera, and light source are solidly interconnected with the mounting device to form a unit which is connected to the lid such that when the lid is open, the unit is substantially vertically disposed, while being at least partially received by the base of the case when the lid is closed for safe storage. The microscope has an adjustable magnification and focus adjustment mechanism for adjusting a magnification of the microscope and a focus of the microscope between two settings to image a breech face impression on the primer surface and a firing pin impression surface in the primer surface so that full images of the breech face and the firing pin impressions can be obtained with good focus using a single adjustment. The apparatus is designed for field use by a police officer having limited training in spent cartridge casing examination imaging, and the images obtained are to be sent to a forensic spent cartridge casing examination center where forensic experts can carry out proper examination of the spent cartridge casing images.
