Review of Camera Performance and Features
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Camera Orientation
The diagram below shows the definition of forward and reverse with respect to a camera body.
Note that the diagram assumes the use of a lens, which inverts the image.
Figure 7: Example of Object Movement and Camera Direction with a Lens
The mechanical diagram shows which direction is designated as forward for the camera. However,
due to the characteristics of the lens, the direction of the objects motion is opposite to the image
motion direction.
Some AOI systems require the scan direction to change at regular intervals. For example, scanning
a panel forwards, coming to a stop, and then scanning backward as the cameras field of view is
progressively indexed over the entire panel. Direction can be dynamically controlled by sending the
appropriate direction command to the camera or via the CLHS General Purpose Input / Output
(GPIO) control bits.
It is necessary for the system to over-scan the area being imaged, including the lines that are not
valid, because of the direction change. This will ensure that valid data will be generated on the
return path as the camera field of view reaches the area to be inspected.
