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5
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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
IC121 SDRAM converts MPEG4 encoded data inside the ASIC,
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 IC182. The audio data is then encoded (AAC) inside the
ASIC, and is then written in sequence onto the SD card to-
gether with the image signals described above.
5-2. Playback
The data is read from the SD card. The encoded data is de-
coded into image data inside the ASIC and then where it is
displayed by the LCD or on a TV monitor. At this time, the
audio data is also decoded, and it is input to IC182 as digital
data. D/A conversion is carried out at IC182, and the sound is
then output to the speaker or to the LINE OUT terminal.
6. Audio CODEC Circuit (IC182)
The audio signals from the microphone are converted into 16-
bit digital data. AD conversion is carried out at a maximum
sampling frequency of 48 kHz.
During audio playback, the 16-bit digital data is converted into
analog signals and these drive the speaker or line out system.
DA conversion is carried out at a maximum sampling frequency
of 48 kHz.
4. Lens drive block
4-1. Focus drive
The 16-bit serial data signals (LENS_SDI) and (LENS_SCLK
and LENS_EN) which are output from the ASIC (IC101) are
used to drive (FOCUS A +, FOCUS A -, FOCUS B + and FO-
CUS B -) by the motor driver IC (IC951), and are then used to
microstep-drive the stepping motor for focusing operation.
Detection of the focus reference position is carried out by the
photointerruptor (F_SENSE) which is inside the lens block.
4-2. Zoom drive
The 16-bit serial data signals (LENS_SDI) and (LENS_SCLK
and LENS_EN) which are output from the ASIC (IC101) are
used to drive (ZOOM A +, ZOOM A -, ZOOM B + and ZOOM B
-) by the motor driver IC (IC951), and are then used to
microstep-drive the stepping motor for zooming operation.
Detection of the focus reference position is carried out by the
photointerruptor (Z_SENSE) which is inside the lens block.
4-3. ND filter
The 16-bit serial data signals (LENS_SDI) and (LENS_SCLK
and LENS_EN) which are output from the ASIC (IC101) are
used to drive (ND+ and ND-) by the motor driver IC (IC951),
and then the ND filter is inserted into and removed from the
beam path.
4-4. Iris drive
The output from the Hall sensor inside the lens is amplified by
the Hall amplifier circuit inside the IC951 motor drive IC, and
the difference between the current and target aperture deter-
mined by the resulting output and the exposure amout (16 bit
serial signal (LENS_SDI) and (LENS_SCLK and LENS_EN))
output from the ASIC (IC101) is input to the servo amplifier
circuit (IC951) to keep the aperture automatically controlled
(DRIVE+ and DRIVE -) to the target aperture, and drive the
galvanometer.
4-5. Shutter drive
This is carried out by applying reverse voltages to the aperture
driving coil. To operate the shutter, the signal
which is output from the ASIC (IC101) is set to a high level
(SHUTTER signals are input to IC951).
