Sigma LBA-710 manual Trigger Delay, CCD Frame Transfer Camera, Interlaced, Cmos Camera, Interlaced

field rate of 60 Hz can cause a trigger pulse to output at a 30 Hz rate. A non-interlaced camera running at a frame rate of 60 Hz can produce a trigger output pulse at a 60 Hz rate.

5.1.3.2Trigger Delay

The LBA-PC will produce trigger output pulses at the programmed frame Interval rate. With the Trigger Delay check box deselected, the trigger output pulses will occur at vertical sync time. With the Trigger Delay check box selected, the trigger output pulses will occur in the middle of the frame of a non-interlaced camera; or in the middle of field 2 of an interlaced camera. The reason to delay the trigger pulse is discussed in the following sections.

5.1.3.3CCD Frame Transfer Camera, Interlaced

These camera types can only capture a laser pulse in one field. Therefore 2x is the highest resolution possible with pulsed lasers. The video output from each laser pulse will occur during the field outputting immediately after the laser trigger arrives. Since the laser is not synchronized with the camera, this means that the pulse can occur in either field. As a result you will observe a field hopping effect in the displayed image.

5.1.3.4CCD Interline and Full Frame Transfer Camera, Interlaced

These camera types can capture a laser pulse in both fields at the same time. Therefore 1x high-resolution images are possible with pulsed lasers. The video output from each laser pulse will occur during the next two fields outputting immediately after the laser trigger arrives.

When the LBA is running, each digitized pixel is being tested for the trigger level pixel value. When a trigger field is detected, the data is retained in the frame buffer and displayed. The timing delay to the next frame that can be acquired depends upon the overhead needed to process the first frame.

As in earlier examples, the Interline camera can display a pulse acquired in both fields while the Frame transfer camera can only use one field. Because of the asynchronous arrival of the laser pulse the Frame transfer image will randomly hop fields.

5.1.3.5CMOS Camera, Interlaced

Most CMOS cameras employ either line or X/Y scanning methods. suited for operation with pulsed lasers. Leave the Trigger Delay camera types.

As a result they are poorly box disabled for all of these

5.1.3.6Tube Camera, Interlaced

With pulsed lasers these camera types will yield an image in both the odd and even fields. Therefore 1x high resolution is possible. Leave the Trigger Delay box disabled for all of these camera types.

Note many tube style cameras will suffer image degradation in the second field, during the readout of the first. Tube cameras also suffer from long lag times, which make them poor devices for any, but the slowest rep rate pulsed lasers.

Operator’s Manual 120 LBA-PC