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Sensors that Achieve High Picture Quality with a 1.75 μm Unit Pixel Size
3M-Pixel, 5M-Pixel, and 8M-Pixel CMOS
Sensors for Cellular Phone Cameras
IMX029/IMX034/
IMX043/IMX058
Along with the recent trend towards higher pixel counts in cameras included in cellular phones,
these cameras are also approaching digital still cameras in their level of functionality.
Furthermore, contemporary cellular phones are becoming even thinner
thus increasing the needs for further miniaturization in the built-in camera system.
Sony has now developed a series of 1.75 μm unit pixel size CMOS sensors
that includes 3M-pixel, 5M-pixel, and 8M-pixel sensors.
These sensors achieve the industry's highest speed and image quality by adopting column-parallel A/D conversion *1.
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IMX029: |
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■ Diagonal 4.51 mm (Type 1/4) 3.22M
effective pixels
■ High-speed serial interface |
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IMX058: |
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■ Diagonal 4.51 mm (Type 1/4) 3.22M
effective pixels
■ High-speed parallel interface |
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IMX034: |
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■ Diagonal 5.71 mm (Type 1/3.2)
5.15M effective pixels
■ High-speed parallel interface |
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IMX043: |
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■ Diagonal 7.18 mm (Type 1/2.5)
8.12M effective pixels
■ High-speed parallel interface |
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*1: See the Featuring section in CX-News Vol. 47.
*2: See the New Products section in CX-News Vol. 46.
*3: See the New Products section in CX-News Vol. 48. |
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Achieving both Miniaturization
and Improved Picture Quality |
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The frequency with which cameras included in
cellular phones, in which pixel counts are
increasing, are used in daily life is increasing
due to their portability. Furthermore, since the
number of users who use these devices as personal recording media is increasing, the
demand for improved picture quality is
increasing as well. At the same time, the
importance of the design of cellular phones is
increasing in the market, and the number of
models that not only feature small sizes and
light weights but that also appeal to users by
emphasizing their thinness is increasing.
Therefore the demands for further
miniaturization in cameras included in cellular
phones can be just as strong as the demands for
even higher picture quality.
Sony has recently developed the 2.5 μm unit
pixel IMX018*2 and 2.0 μm unit pixel
IMX020*3 compact, high picture quality
CMOS sensors, which have been well received
by the market due to their superlative imaging
characteristics, including their high picture
quality, high resolution, and high frame rates.
Now, to respond to further market demands, we
have developed compact, high picture quality
CMOS sensor products based on a 1.75 μm
unit pixel. To increase the size of the pixel
aperture even slightly, we have adopted a Cu
process that can implement even finer
interconnects, and, by developing a new
condenser structure, have succeeded in
improving the condensing performance relative
to the angle of incidence of the light on the
sensor. (See figure 1.) Also, we achieved both
a high electron efficiency (photoelectric
conversion efficiency) and a high saturation
signal level by improving the semiconductor
process and achieved the same high signal-to-noise
ratio as the IMX020 despite the pixel
miniaturization. |
Extensive Variations |
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In the IMX034 and IMX043, we adopted the
same 2-channel data strobe sub-LVDS serial
interface used in the IMX020, thus making it
possible to read out all 8M pixels from the
IMX043 at 15 frame/s. While this results in
high-speed signals that reach 130 MHz at 10
bits/pixel in this case, this allows stable
transfers even in cellular phones. Furthermore,
we are responding to a wide range of market
needs by also releasing the 10-bit CMOS
parallel interface IMX058 and the 1-channel
data strobe sub-LVDS serial interface IMX029
3M-pixel products.
Another point is that the percentage of cameras
included in cellular phones that provide an AF
function is increasing. In this 1.75 μm unit
pixel CMOS sensor series, Sony contributes to
reduced system costs and module
miniaturization by including drivers that can
also control AF actuators. |
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Mr. Makino and Mr.Yamaguchi
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Are you dissatisfied with cellular phone
camera image quality? I certainly am.
This is why I was willing to struggle with
image quality improving technologies, no
matter how difficult they were. As a result,
the developers and staff on this project
were able to create sensors with these
characteristics.
Furthermore, we hope that by providing
this diverse lineup from 3M to 8M pixels
even more customers will try out these
products. |
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See
all articles with figures and tables.  |
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Vol.54 |
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