Sony SNC-CS50P - Manual (Page 15)

15
CCD with Exwave HAD Technology
The CCD with Exwave HAD technology was developed to
provide extra sensitivity for both visible and near infrared
regions of the spectrum, allowing the camera to capture
bright images both during the day and night.
Inheriting the OCL structure from the Super HAD CCD,
Exwave HAD technology further increases sensitivity by
incorporating an internal lens layer between the color
filter and photo shielding film (Fig. 3). These internal
lenses are used to efficiently converge light that was not
converged toward the photo sensor by the OCL. This
double convergence structure enables more light to be
directed to the photo sensors.
As a result, the CCD incorporating Exwave HAD
technology has a higher sensitivity than the Super HAD
CCD.
In addition to this higher light convergence capability,
Exwave HAD technology uses a unique structure to
improve the CCD sensitivity to near infrared light.
This enhancement allows much brighter images to be
captured in the dark using the Day/Night function.
With earlier CCD structures, near infrared light was
difficult to capture because of its nature of being
converted to electric charges in areas deeper than the
photo sensor surface. By extending the photo sensor
deeper into the silicon substrate, the CCD with Exwave
HAD technology achieves a much higher sensitivity to
infrared light, allowing images to be captured in extreme
darkness.
Furthermore, Exwave HAD technology incorporates a
thinner insulating film between the silicon substrate and
the electrodes. Compared to earlier-generation CCDs,
this structure reduces the amount of light that leaks
directly into the vertical shift register, and suppresses the
smear level.
CCD with SuperExwave Technology
SuperExwave technology adds a further improvement to
the sensitivity of Exwave HAD technology, especially for
near infrared light. SuperExwave technology improves on
Exwave HAD technology by changing the structure of the
photodiodes in such a manner that it has even higher
photoelectric conversion efficiency. This structure can
capture even more of the light in the near infrared region
that would normally escape to the substrate in normal
CCD image sensors. As a result, the sensitivity in the near
infrared region is increased by approximately 50%, and
sensitivity of visible light is increased by approximately
10% compared to the CCD with Exwave HAD technology
(Fig. 4).
Fig. 4 Comparison Between SuperExwave and Exwave HAD
Technology *1
*1 This chart has been simplified to show the difference in sensitivity between SuperExwave and Exwave HAD. The values are for reference only.
1.20
1.00
0.80
0.60
0.40
0.20
0.00
300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
Wavelength (nm)
Relative Response
SuperExwave
Exwave HAD
Visible
wavelength
region Near
infrared
region
Shooting environment: LED lights (wavelength 950 nm, irradiation
distance 1 m), Dark room
<SuperExwave> <Exwave HAD>