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The basic movement
the CD changer is described as follows.
See
2 and
3.
• The CD changer basically consists of the tray (208) which slides
on the
CD
chassis (224), and the main gear (238) to move the
tray. As the main gear rotates, the projection (Zenbea Pi.n) on
the main gear causes rotation of the CD up/down cam (241),
resulting in up/down of the CD mechanism and CD chucking.
The main gear is driven by Loading Motor MTR1.
On the tray (208),the turntable (209) to load a disc and the disc
select motor MTR2 to rotate the turntable are set up. MTR2
controls the turntable movements. MTR2 which rotates on the
tray can rotatethe disc table regardlessof the open/close motion
of the tray.
• The following arethe electric parts which controlthe movements
to open/close the tray and to rotate the turntable.
Tray Driving Motor (Loading Motor) : MTR1
Tray Open Switch to detect that the tray is completely
open: SW1
Photo Sensor (Tray Close SW) to detect that the tray is
closed: PHi
Photo Sensor (Mecha UP SW) to detect that the CD mecha-
nism is UP : PH2
Turntable Driving Motor (Disk Select Motor) : MTR2
Photo Sensor (Disc Select SW) to detect the disc table
position: PH3
The Table
2
below shows the ports of the microcomputer
(IC801)
to decode signals and to drive with the use of the above parts.
Under the main gear to control the tray movements, a double
screen of concentric circle is placed. The relationof the maingear
rotating position and the tray position is
1:1.
Height of the screen
can be changed with the tray closed or at the main gear position
corresponding to the tray position where the CD mechanism is
moved up/down. As a result, the
LED
light of the photo sensors
PH1 and PH2 can be shut or passedto change output of PH1 and
PH2 high and low. The tray movement is controlled by changing
this signal.
The signals PHi and PH2 change depending on the height of
peripheral screen, and the inner screen, respectively. When the
screen is placed low, the LED light is passed to make the photo
transistor inside the sensor turn ON, resulting in low output
(approx.0.2V). On the other hand,whenthe screenis placed high,
the light is shut to makethe photo transistor OFF, resulting in high
output (5V).
Summary:
MTR1 : Controls opening/closing of the tray and up/down of the
CD mechanism.
[MTR1 rotation(clockwise/counterclockwise)
~J
S'
It
R
t
tl
d'
tl
f th
.
irnu aneous
~
0
a Ing
irec
Ion
0
e main gear
~
t
f
~
Opening/closing of the tray
two tvoes
S 0
.
wo ypes
~
Up/down of CD mechanism
MTR2 : Controls the turntable rotation.
The movementsof the main gear and the tray, which are
structurallycomplicated, will be explained independently
in the other section. Thereafter, the turntable movement
will be described.
PORT
.-UN\.,; IIVN
OF MICROCOMPUTER
NAME
CIRCUIT DIAGRAM
•
Port for Macha UP SW(PH2)
ICaDi
44 pin
MECHA UPSW
Port for Tray Close SW(PH1)
47 pin
CLOSESW
Port for Tray Open SW(SW1 )
48 pin
OPENSW
Port to drive MTR 1
45 pin
CLOSE MTR
46 pin
OPEN MTR
Port to drive MTR2
42 pin
MTR+
41 pin
MTR-
Port for Disc Changer SW(PH3)
43 pin
DISCTBLSW
2
OPEN
}J.-COM
IC801
SW1
Tray close
photo sensor
Loading motor
(MTR1)
Disc select motor
(MTR2)
Disc changer
photo sensor
-2-
2
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