Spyder3 S3-14 and S3-24 Monochrome Camera User's Manual
77
Teledyne DALSA
03-032-20117-01
Appendix A
Clearing Dark Current
Gate Dark Current Clear
N ote:
This featu re is not available for the S3-24-04k40 cam era m od el.
Im age sensors accu m u late d ark cu rrent w hile they w ait for a trigger signal. If the read ou t is not triggered
in a reasonable am ou nt of tim e, then this d ark cu rrent accu m u lation m ay increase to an excessive
am ou nt. The resu lt of this hap p ening w ill be that the first row , and p ossibly ad d itional row s (fram es), of
the im age w ill be corru p t.
The sensor u sed in th is cam era contains tw o sou rces of d ark cu rrent that w ill accu m u late w ith tim e: 1) in
the p hoto sensitive area, an d 2) in the gates u sed to clock-ou t the charge.
The gate d ark cu rrent can accou nt for ap p roxim ately 20% of the total d ark cu rrent p resent. While the
exp osu re control has d irect control over the am ou nt of d ark cu rrent in the p hot o sensitive area, it has no
control over the ch arge accu m u lated in the gates. Even w ith exp osu re control on, at low line rates, this
gate ch arge can cau se the cam era to satu rate.
Using the
Set Readout Mode (srm)
com m and , the cam era u ser can control the cam era's behavior in
ord er to m inim ize the d ark cu rrent artifact.
The m od es of op eration selected by the
srm
com m and are: Au to, On, or Off.
N ote: This com m and is only available in low sensitivity and tall p ixel m od es. H igh sensitivity m od e
op erates only in th e im m ed iate read ou t p osition.
0Hz
Watchdog
Frequency
Max. Line Rate in
Immediate
Readout Mode
Increasing Line Rate
Frequency
Dark Current
Clear
Immediate
Readout
Dark
Current
Clear to
Immediate
Readout
Transition
Frequency
Immediate
Readout to
Dark
Current
Clear
Transition
Frequency
Max. Line Rate in
Dark Current Clear
Mode
Mode
Figure 28: Gate Dark Current Clear
Table 17.
Transition Frequencies
Model
Dark Current Clear to Immediate Readout
Transition
Immediate Readout to Dark
Current Clear Transition
S3-14-01k40
13.6KH z
16.4KH z
S3-24-01k40
25.1KH z
30.4KH z
