The basic movement the CD changer is described asfollows.
See 2 and 3.
• The CDchangerbasicallyconsistsofthetray(208)whichslides
on the
CD chassis (224), and the maingear (238) to movethe
tray. Asthe main gear rotates, theprojection (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 maingear is driven by Loading Motor MTR1.
Onthetray (208),theturntable (209)toload a discandthe disc
select motor MTR2 to rotate the turntable are set up. MTR2
controls the turntable movements. MTR2 which rotateson the
traycanrotatethedisctableregardlessoftheopen/closemotion
of the tray.
•Thefollowingarethe electricpartswhichcontrolthemovements
to open/closethe tray and to rotatethe 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
PhotoSensor (Mecha UP SW)to detect that the CD mechanism is UP :PH2
Turntable Driving Motor (Disk Select Motor) : MTR2
Photo Sensor (Disc Select SW) to detect the disc table
position: PH3
TheTable
2 below showsthe 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
screenofconcentriccircle is placed.The relationofthemain
gear
rotatingpositionandthe trayposition is 1:1. Height of the screen
can bechanged withthe tray closed or at the maingear position
corresponding to the tray position where the CD mechanism is
movedup/down. Asa result,the
LEDlight ofthe photo sensors
PH1and PH2 can be shut or passedto changeoutput of PH1and
PH2 high and low.The tray movementis controlled by changing
this signal.
The signals PHi and PH2 change depending on the height of
peripheralscreen, andthe inner screen, respectively.When the
screen is placed low, the LED light is passed to makethe photo
transistor inside the sensor turn ON, resulting in low output
(approx.0.2V). Ontheotherhand,whenthe screenisplacedhigh,
the lightisshutto makethe phototransistorOFF, resultinginhigh
output (5V).
Summary:
MTR1
:Controls opening/closingof 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 Ion0 e main gear
~
t f
~
Opening/closingof the tray
two
tvoes S 0
. wo ypes
~
Up/downof CD mechanism
MTR2 :Controls the turntable rotation.
The movementsofthe maingear andthe tray, whichare
structurallycomplicated,willbeexplainedindependently
inthe othersection.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 MTR1 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)
Discselect motor
(MTR2)
Disc changer
photosensor
-2-
2