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4. Lens drive block
4-1. Focus drive
The focusing motor is a stepping motor that is microprocessor
driven by IC951. When input the control signal (FCW, FOE
and FCLK) which are output from the ASIC port (IC101), the
focusing motor is driven microstep by IC951. Detection of the
standard focusing position is carried out by means of
photointerruptor sensor inside the lens block.
4-2. Zoom drive
The zoom motor is a stepping motor that is microprocessor
driven by IC951. When input the control signal (ZCW,
ZOOMOE, and ZCLK) which are output from the ASIC port
(IC101), the zoom motor is driven microstep by IC951. Detec-
tion of the standard zoom position is carried out by means of
photointerruptor sensor inside the lens block.
4-3. ND filter
IC951 turns the ND filter on and off when ND ON and ND OFF
signals are input to IC951 respectively.
4-4. Iris drive
The output from the Hall sensor inside the lens is amplified by
the Hall amplifier circuit in the lens drive block, and the differ-
ence in the target aperture values that are determined by the
output from that and by the exposure level output from the
ASIC is input to the servo amplifier circuit to automatically con-
trol the aperture opening so that it matches the target aperture
setting.
4-5. Shutter drive
The shutter is operated by applying a reverse voltage to the
aperture coil mentioned above. During normal operation, the
NAESW signal that is output from the ASIC is held at a High
level, but when the shutter operates, the NAESW signal be-
comes Low and after that the SHUTTER signal that is output
from the ASIC becomes High and the shutter operates.
5. Video clip recording and playback
5-1. Recording
The signals from the camera block are input to the ASIC where
they are processed, and the image data that is stored in the
SDRAM built-in IC101 is input to the IC102 MPEG4 CODEC
LSI. The CODEC LSI converts this data to encoded MPEG4
data, after which it is returned to the ASIC as streaming data,
and the data is then written in sequence onto the SD card. At
this time, the audio signals that are input to the built-in micro-
phone are converted into digital data by the audio CODEC IC
of IC183, and they are then input via the ASIC to IC102 (MPEG4
CODEC). The audio data is then encoded (AAC) by IC102,
and then it is returned to the ASIC as streaming data and is
then written in sequence onto the SD card together with the
image signals described above.
5-2. Playback
The data is read from the SD card and input to IC102 as stream-
ing data. The encoded data is decoded into image data by
IC102 and then returned to the ASIC where it is displayed by
the LCD or on a TV monitor. At this time, the audio data is also
decoded by IC102, and it passes through the ASIC and is in-
put to IC183 as digital data. D/A conversion is carried out at
IC183, and the sound is then output to the speaker or to the
LINE OUT terminal.
6. Audio CODEC circuit (IC183)
The signals from the camera block are input to the ASIC where
they are processed, and the image data that is stored in the
SDRAM of IC104 is input to the IC102 MPEG4 CODEC LSI.
The CODEC LSI converts this data to encoded MPEG4 data,
after which it is returned to the ASIC as streaming data, and
the data is then written in sequence onto the SD card. At this
time, the audio signals that are input to the built-in microphone
are converted into digital data by the audio CODEC IC of IC183,
and they are then input via the ASIC to IC102 (MPEG4
CODEC). The audio data is then encoded (AAC) by IC102,
and then it is returned to the ASIC as streaming data and is
then written in sequence onto the SD card together with the
image signals described above.
