Nikon Coolpix 5700 Repair Manual page 36

3. IC904 and IC906 (V Driver)
IC904 and IC906 are vertical clock driver for image
sensor. The ternary pulse of V φ 1 (A, B and C) and V
φ 3 (A, B and C) for CCD which are output from
ASIC (IC102) are generated to add the sensor reading
clock (XSG**) and the vertical transfer clock (XV*). V
φ 2, V φ 4 and the two pulse of φ SUB for CCD
which are output from ASIC (IC102) are generated
from vertical transfer clock (XV*).
4. IC905 (H Driver, CDS, AGC and A/D converter)
IC905 contains the functions of H driver, CDS, AGC
and A/D converter. As horizontal clock driver for CCD
image sensor, H φ 1 (A and B) and H φ 2 (A and B)
are generated inside, and output to CCD.
The video signal which is output from the CCD is input
to pins (29) of IC905. There are sample hold blocks
inside IC905 generated from the SHP and SHD pulses,
and it is here that CDS (correlated double sampling) is
carried out.
After passing through the CDS circuit, the signal passes
through the AGC amplifier (PGA: Programmable Gain
Amplifier). It is A/D converted internally into a 12-bit
signal, and is then input to ASIC (IC102). The gain of
the AGC amplifier is controlled by pin (36)-(38) serial
signal which is output from ASIC (IC102).
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Fig. 1-3. IC902 Block Diagram
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5. Lens drive block
5-1. Focus drive
The focus stepping motor drive signals (FM RESETB,
FM CW, FM CLK and FM OEB) which are output
from ASIC expansion port (IC108) are used to drive
micro step by the motor driver (IC951). Detection of
the standard focusing positions is carried out by means
of the photointerruptor (FPI) inside the lens block.
5-2. Zoom drive
The DC motor drive signals (ZIN1 and ZIN2) which
are output from 8-bit microprocessor (IC301) are used
to drive by the motor driver (IC953). Counting and
detection of the standard zoom positions is carried out
by means of photoreflector (ZPI) inside the lens block.
5-3. Iris drive
The iris stepping motor drive signals (IIN1, IIN2, IIN3
and IIN4) which are output from the ASIC expansion
port (IC106) are converted into drive by the motor drive
(IC952), and are then used to drive the iris steps.
5-4. Shutter drive
The two shutter motor drive signals (SIN1, SIN2)
which are output from the ASIC expansion port (IC106)
are converted into drive pulses by the motor drive
(IC952), and the mecha shutter is opened and closed by
regular current drive.
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- E2 ･ E5700 -
VAA11801-R.3578.A