Cmos Image Sensor Unit Block; Dsp (Digital Signal Processor) Block; Fm Modulation Block; Fm Demodulation Block - Panasonic VL-SVN511BX Service Manual

VL-SVN511BX/VL-SVN511CX/VL-SVN511CX1
4.2.2.

Cmos Image Sensor Unit Block

Cmos image sensor unit and DSP blocks are shown in Fig. 1.2. Basically the image through the lens is converted into the elec-
tric signal by the optical filter and cmos image sensor. Then it is transferred to the DSP block.
4.2.3.

DSP (Digital Signal Processor) Block

In the DSP block the analog RGB signal is converted into the digital data, and the image is processed for NTSC.
After that it is converted into the analog signal again to become NTSC signal.
4.2.4.

FM Modulation Block

There are two ways of transferring image, one is FM and the other is AM. FM is chosen in this model because it is hardly influ-
enced by the ambience noise. The anti-noise performance is an essential point because the interphone cable can be placed
anywhere in house.
4.2.5.

FM Demodulation Block

The FM signal from the interphone cable is demodulated into the NTSC signal in the Monitor station.
4.2.6.

LCD Controller and Color LCD Module

Since the demodulated signal is NTSC, it's necessary to be converted to the Y/C signal for LCD module.
Block diagrams of LCD controller and LCD module are shown in Fig. 1.6.
NTSC signal per line is separated into Y (Luminance, Brightness) signal and C (Chroma) signal in Y/C separation circuit.
Y/C signal for X-driver is produced by being added some compensations (Gamma, Brightness, Contrast and so on) in Y/C inter-
face circuit.
Also timing controller makes the horizontally and vertically synchronized signals for X-Y driver of LCD module.
These signals drive each LCD's cells of a screen and then the image of a screen is displayed on the LCD.
LCD requires backlight because LCD itself does not light up.
Fig. 1.2 CCD & DSP block
Fig. 1.6 Color LCD module & LCD controller
10