Interleaved Area-scan Acquisition Principles

System Description

The following drawing shows the main elements of an area-scan acquisition system configured for Interleaved Area-scan Acquisition:

The system is composed of:
  • One asynchronous reset grabber-controlled exposure area-scan camera.
  • One acquisition channel of a compatible Grablink frame grabber configured for Interleaved Area-scan acquisition.
  • Two illumination devices, each being controlled by a specific strobe output of the frame grabber.

Usually, the Trigger event is delivered by a presence detector.

All area-scan acquisition modes (SNAPSHOT and HFR) are compatible with Interleaved Area-scan Acquisition.

Operation

The Interleaved Acquisition feature allows to capture, with a time-optimized sequence of two camera cycles, two images with different exposure time, strobe duration, strobe delay and strobe output settings.

The first cycle of the sequence uses the settings defined by P1, the second cycle uses the settings defined by P2.

The following drawing shows an acquisition sequence of two overlapping cycles where the exposure time is smaller than the readout time for both cycles:

The above sequence is time-optimized:
  • The exposure of the second cycle overlaps the readout of the first cycle.
  • The exposure of the second cycle terminates exactly when the readout of the first cycle terminates.

Double Exposure Mode Emulation

The following drawing shows a particular Interleaved Area-scan Acquisition sequence of two overlapping cycles where the second exposure time matches the readout time:

The exposure time of the second cycle is increased to become equal to the readout time. This allows the second strobe to be issued immediately after the first strobe.

This emulates the double exposure mode.