Hamamatsu Photonics C9300-124, Инструкция по эксплуатации

Страница: 34 / 46

C9300-124 Ver.1.4
33
11. PRECAUTIONS WHEN USING THE CCD
The camera uses a CCD. Careful attention must be paid to the following points when using
a CCD:
(1) White spots
Subjecting the CCD to extended exposures may cause failure in part of the silicon
wafer, resulting in white spots. This phenomenon is not currently preventable. If the
CCD is at a fixed temperature, recurrence of the white spot increases proportionally
with the exposure time, so this can be rectified with dark subtraction*. Atomic ray may
generate white spot.
Note
•
Regarding the specifications at the shipment, please refer to section 14-3.
*
After acquiring an image using an arbitrary exposure time, the CCD is placed in a dark state for an equal amount of
time, and reacquires the image without any light exposure. Subsequently, the second image is subtracted from
the first, canceling dark-area information from the original image.
(2) Smear
This is a phenomenon whereby bright vertical striations (vertical smear) appear on the
images of bright objects. This is caused by vertical charge leakage in the CCD. The
amount of smear is dependent on scan time and exposure time.
Impact from smear is not an issue for the camera in normal frame blanking mode, but
sometimes becomes an issue when exposure time is shortened in electronic shutter
and external exposure time modes.
(3) Folding distortion
A rough-edged flicker may be visible when imaging striped patterns, lines, and similar
subject matter.
(4) Interference fringes pattern
Coherent light such as LASER light may generate interference fringes pattern on
image.
(5) Over light
CAUTION
•
Be careful not to input too strong light such as high-energy laser into
CCD chip because CCD chip may be damaged by over light.
(6) Dual readout mode
Note
•
Dual readout mode uses two separated readout Amp whose performance is not
perfectly same. Due to the readout Amp characteristics variation, you may see
little intensity gap between right side and left side in one image even though the
fine adjustment is done at factory before shipping. Single readout mode is
recommended to achieve the best possible image quality.
12. MAINTENANCE
12-1 CARE
Clean the exterior with a soft, dry cloth.
•
Do not use a wet cloth, dirty cloth.