Description Of Operation; Description Of Mechanism - Hitachi DZ-MV350A Service Manual

3

Description of Operation

3-1 Description of Mechanism

(1) Lock mechanism of disc loading block (lock unit)
Since the structure of disc loading block in DZ-MV350A is different from that of the lock unit in
previous models, it will not open unless a power supply (battery or AC adapter/charger) is
connected.
The lock arm in DZ-MV350A lock unit is driven by the DC motor controlled by a microprocessor (see
Fig. 3-1-1).
The lock arm is usually in locked status: When the DISC EJECT button is pressed, the DC motor
drives the lock arm in the release direction.
DISC
EJECT
button
The lock arm in lock units of previous models is mechanically coupled with the DISC EJECT button
via a solenoid , except when disc is being accessed (see Fig. 3-1-2).
*1
The solenoid is controlled by the current supplied from camera control microprocessor.
While the disc is being accessed, the camera control microprocessor outputs the current and controls
the solenoid to release the coupling between DISC EJECT button and lock arm, so that the disc
loading block does not open.
If no power supply is connected, the camera control microprocessor will not operate, and the
solenoid will not release the coupling.
*1: A device that converts electrical energy to mechanical energy, using the magnetic force that is generated
when current flows to electromagnetic coil.
In status other than
disc access
Lock unit
Solenoid
Camera
control µP
Camera
SH µP
control µP
Fig. 3-1-1 Lock Unit in DZ-MV350A
DISC
Lever
EJECT
button
Open
Lock arm
Case
Fig. 3-1-2 Lock Unit on Previous Models
3 - 1
µP in disc
DC
M
drive unit
motor
Lock arm
During disc access
Lever
Lock unit
Solenoid
Lock arm
Current
Camera
control µP
Lock unit
Spring
Release
direction
DISC
EJECT
button
Open
Case