Sanyo VPC-X360, Service Manual

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3. LCD Block

During EE, gamma conversion is carried out for the 10-bit
RGB data which is input from the A/D conversion block of the
CCD to the ASIC in order that the 

γ 

revised can be displayed

on the video. The YUV of 640 x 480 is then transferred to the
SVRAM.
The data which has accumulated in the SDRAM is after D/A
conversion is carried out by SDRAM control circuit inside the
ASIC , makes Y/C signal, the data is sent to the LCD panel
and displayed.
If the shutter button is pressed in this condition, the 10-bit
data which is output from the A/D conversion block of the
CCD is sent to the SDRAM (DMA transfer), and is displayed
on the LCD as a freeze-frame image.
During playback, the JPEG image data which has accumu-
lated in the SSFDC card is converted to RGB signals. In the
same way as for EE, the data is then sent to the SDRAM,
after which D/A conversion is carried out inside the ASIC,
and then the data is sent to the LCD panel and displayed.
The LCD driver is converted Y/C signals to RGB signals from
ASIC, and these RGB signals and the control signal which is
output by the LCD driver are used to drive the LCD panel.
The RGB signals are 1H transposed so that no DC compo-
nent is present in the LCD element, and the two horizontal
shift register clocks drive the horizontal shift registers inside
the LCD panel so that the 1H transposed RGB signals are
applied to the LCD panel.
Because the LCD closes more as the difference in potential
between the VCOM (common polar voltage: fixed at DC) and
the R, G and B signals becomes greater, the display becomes
darker; if the difference in potential is smaller, the element
opens and the LCD become brighter. In addition, the bright-
ness and contrast settings for the LCD can be varied by means
of the serial data from the ASIC.