Pioneer PR-8210-A User manual

Б ДУ,
с
РТИапиа1
|
=
ORDER
NO.
VRT-019-0
VIDEO DISC PLAYER
8-8210-А
~
eS
CONTENTS
1.
SPECIFICATIONS
аа.
2
11-2
SYPS,
LSPS
AND
МСМВ............
76
2.
PARTS
АМО
CONTROLS
...............
3
TUSUREAMUS
Ы
лы
t
EM
Ed
81
3.
CONNECTIONS...
5
114
УЗОР,
CPCB
AND
Р$СВ............
83
4.
DISASSEMBLY
.......
ре
Dieu
1:5
AUDX
occ
ccc
ccc
ыа
ea
94
5.
CIRCUIT
DESCRIPTIONS
...............
9
11.6
CONT,
GATB
AND
IOIB
...........
98
»^
6.
SAFETY
CHECK
.....2...............
39
112
КЕҮС
AND
IRAB
................
104
t
7.
MECHANICAL
ADJUSTMENTS
........
a
12.
EXPLODED
VIEWS
AND
PARTS
LISTS
....
108
.
8.
SLIDER
ASSEMBLY
AND
ALIGNMENTS
...
45
12-1
EXTERNAL
AND
TOP
VIEW
........
108
9.
ELECTRICAL
ADJUSTMENTS
............
53
122
BOTTOM
VIEW
..................
111
10.
TROUBLE
SHOOTING
.............
‚..
68
123
SLIDER
с...
114
11.
SCHEMATIC
DIAGRAMS,
PCB
13.
SAFETY
INFORMATION
...............
116
PATTERNS
AND
PARTS
LISTS
..........
723
14.
PACKING
PROCESS
...................
117
11-1
OVERALL
isses
ee
73
О PIONEER’
pm
PIONEER
ELECTRONIC
CORPORATION
4-1.
Meguro
1-Ch^orne,
Meguro-ku,
Tokyo
153,
Japac
PIONEER
ELECTRONICS
(ОВАЈ
INC.
РО.
Box
1760,
Long
Beach,
Самого
e
90801
USA
PIONEER
ELECTRONIC
[EUROPE]
М.М.
Keetbenglaan
1,
2740
Beveren,
Begum
PIONEER
ELECTRONICS
AUSTRALIA
РТУ.
LTD.
178-184
Boundary
Fload,
Braeside.
v
ctor
a
3195,
Азатгета
Printed in Japan МЕ $1 10

PR-8210-A
1. SPECIFICATIONS
General
System and disc spec.
ЕЕ
Comply
with
MCA
Philips
specifications
*1 Maximum playing time
bw n rub АТ Standard play videodisc: 30 minutes/side
..... . Extended play videodisc: 60 minutes/side
Spindle motor revolutions
"P Standard play videodisc: 1800 RPM
SAMT NE RUE a Extended play videodisc: 1800 RPM
(inner circumference)
to 600 RPM {outer circumference}
Laser е 6328 angstrom, He-Ne 1mW
Video Characteristics
Format seated ае ay PG NTSC specification
Video output
Level ... 1Vp-p nominal, sync. negative, terminated
impedance ............., 75 ohm unbalanced
Terminal ЕЕН aN BNC type jack
Signal to noise ratio ............ More than 42dB
Audio Characteristics
Audio output.......-. Two channels; stereo or two
individual channels
Level ........ 650mV nominal (1kHz 100% mod.
50 kilohms terminated)
Impedance ..... Less than 2.2 kilohms unbalanced
Terminal с, ва ваља Stereo pinjacks
Total harmonic distortion . Less than 0.396
(1kHz 7596 mod.)
Signal to noise ratio ............ More than 70dB
(CX encoded disc, CX NR ON, 1kHz 650mV
output, using IHF A network)
Frequency response. . . 40Hz to 20kHz (+3dB reference
to 1КН2 10% mod.)
External controls
Terminal: zs TET 24 Pins amphenol type
Functions
CAV CLV
Play (Normal play mode with sounds) ... YES YES
Pause (Pause mode without picture
and sounds) «o ius ыы tm тағы YES YES
Scan forward/reverse ............... YES YES
Others
Power requirements ............ AC 120V, 60Hz
Power consumptions ................. 85-watts
Dimensions ........ 525(W) x 408(D) x 143(H) mm.
20-21/32(W) x 15-13/16(D) x 5-5/8(H) in.
Net weight (without package) ...... 13.5kg (29.8 lbs)
Furnished Accessories
Audio connecting cords with pinplugs .......... 1
Operating instructions ..................... 1
NOTES:
Specifications and the design subject to possible modifica-
tion without notice, due to improvements.
*1 Actual playback time differs for each disc.
we

=
2.
PARTS
AND
CONTROLS
®
DISC
CLAMP
This
holds
the
disc
onto
the
turntable
when
the
hood
is
closed
to
assure
that
the
disc
rotates
smoothly.
@ TURNTABLE
Place
a
disc
on
this
platter
so
it
fits
over
the
raised
center
hub.
The
turntable
is
directly
connected
to
the
motor
so
the
precise
speed
is
maintained
at
all
times.
($ OBJECTIVE LENS
This
lens
focuses
the
laser
beam
onto
the
disc
and
picks
up
the
beam
reflected
back
from
the
disc.
Note
that
the
lens
surface
must
be
kept
clean
in
order
to
maintain
optimum
performance.
@ POWER
Press this switch to turn power on and off.
® POWER INDICATOR
This lights up to show the power is on.
© REJECT/OPEN
Press this key to cut off operation and to open the
hood.
(D HOOD UNLOCKED INDICATOR
This
indicator
lights
up
when
the
hood
is
open
and
goes
out
when
the
hood
is
completely
closed
and
locked.
Note
that
the
player
can
not
be
operated
until
this
indicator
goes
out.
(& STAND BY INDICATOR
This indicator flashes on and off during those peri-
ods when some time is required for the player to
switch to the next commanded function mode.
For example: When > marked end of the PLAY/
PAUSE
key
is
pressed
after
REJECT,
during
the
return period.
@ DISC INDICATORS
A
few
moments
after
»
marked
end
of
the
PLAY/
PAUSE
key
has
been
pressed,
опе
of
these
indica-
tors
shows
whether
a
CAV
or
CLV
disc
is
being
played.
@ PLAYBACK MODE INDICATORS
One of these indicators shows the playback mode
presently selected.

PR-8210-A
1)
CX
INDICATOR
This
indicator
lights
when
the
CX
noise
reduction
system
is
activated.
42
AUDIO
INDICATORS
These
indicators
show
whether
only
one
or
both
audio
channels
are
being
heard.
@
SLOW
SPEED
CONTROL
Use
this
contro!
to
adjust
the
speed
of
slow
motion
playback.
NOTE:
Slow
motion
playback
is
possible
only
when
an
ex-
ternal
controller
is
being
used
to
contro!
the
player.
Slow
motion
playback
can
not
be
рег-
formed
using
the
buttons
on
the
player
itself.
@ PLAY/PAUSE
Pressing
the
|»
mark
on
the
upperside
of
the
switch
starts
playback
or
returns
to
normal
play
mode
from
another
mode.
To
temporarily
stop
playback,
press
the
М
mark
on
the
lower
side
of
the
switch.
This
stops
the
pickup,
turns
off
both
picture
and
sound.
Pressing
the
И
mark
again
can-
cels
the
pause
mode.
4$ SCAN
Use
this
key
to
quickly
locate
a
particular
part
of
the
disc
program
or
skip
a
part
of
the
program.
pe
:
press
to
scan
quickly
forward
44:
press
to
scan
quickly
backward
4%
AUDIO
1/1,
2/R
Use
this
key
to
turn
sound
off
and
on
in
the
left
or
right
channel.
Pressing
either
end
of
the
key
turns
off
sound
in
that
channel;
press
again
to
turn
sound
back
on.
@ CX SYSTEM
This
key
turns
the
CX
noise
reduction
system
on
and
off.
Turn
the
CX
system
on
when
playing
a
CX
encoded
disc.

3.
CONNECTIONS
PR-8210-A
22)
~ ә)
6)
e
VIDEO IN
1
ME 1
|
і Stereo amplifier
|
Use the coaxial cable to connect the VIDEO OUT
terminal on the player to the video input terminal
on the monitor TV or other video equipment
(terminated video input terminal).
Audio output on the player should be connected
to the audio inputs of the monitor TV (or other
video equipment) or to the stereo system for audio
reproduction.
@ AUDIO OUT
These jacks provide the left and right channel
audio signals for connection to a stereo hi-fi sys-
tem.
(à EXT CONTROL
This terminal is used as an МО port when the
player is controlled by a controller.
Video monitor TV or
othar video equipment
NOTE:
The
connections
diagram
shows
only
one
example
of
the
possible
ways
to
perform
connections.
The
method
of
connection
differs
depending
on
the
control
unit,
video
equipment
and
other
units
being
used.
© VIDEO OUT
The terminal is for connection to a color video
monitor TV or other video equipment (that have
video input terminal). It provides the direct video
signal.
@ POWER CORD
Plug this into a wall socket.

E
a«a
I
=
4. DISASSEMBLY
1. ENCLOSURE AND PCBS
‚^^
А В
С
ты
CC
Caution label B
VRW-O71
Under housing
@ Unscrew 7 screws
marked 6).
Printed circuit Front panel
boards p
* Unscrew 4 screws * Unscrew 3 screw:
marked $). marked @..
Top housing
* Undo the под, and $1
disengage the locking
* Unscrew 3 screws mi
the turntable.
* Unscrew 9 screws mi
Remove parts in the order
above sequence diagram. For exa
© © the top housing, the under housing
and the hood must first be remove
Note: Loosen the shipping screw |
ing disassembly procedures
tion of repairs, check th
screw, lens cap, shield ca
other shields have been f
positions.
3 7

PR-8210-A
2. HOW TO REMOVE SLIDER FROM
MECH-CHASSIS
1.
Remove
the
four
fixing
screws
on
the
VSOP
board, and open the VSOP.
2. Put the slider harness out of the joint by re-
moving
the
E
washer,
and
disconnect
the
A
housings N4, N5, and high voltage cap.
.
Remove
the
two
screws
installed
the
slider-pot
assembly.
К
.
Remove
the
four
screws
installed
the
rail
near
„ the slider pot.
©з
NN
N
SLIDER
ES
UN
WARNING: EXTREME CARE MUST BE EXERCIS-
ED TO "LSPS" BOARD WHILE WORKING WITH
THE PLAYER TO PREVENT POSSIBILITY OF
EXPOSING YOURSELF TO DANGEROUS VOLT-
AGES.
er housing
Unscrew 7 screws
marked .6`.
* Open the hood,
and unscrew
6 screws |
nt
panel
marked
(V.
Unscrew 3 screws
marked :4..
) housing
jo the ring, and shift to one side to
ngage the locking catches.
crew 3 screws marked (2), and remove
y
turntabie. _
crew 9 screws marked (3:. (
¢ f
SA Эм
. the order indicated in the
am. For example, to remove
inder housing, the front panel
st be removed. М
93
pping screw before commenc-
y procedures. Upon comple-
s, check that the shipping
ip, shield case, barrier, and
have been fixed in suitable

—
PR-8210-A
5. CIRCUIT DESCRIPTIONS
5-1 RFAM
RFAM consists of PHDB (photo detector is an emitter follower. The RF OUT signal is
board) and HEDA (head amp) is mounted on the extracted from this point.
slider assembly. The photo detector mounted on The four focus control signals are B1 thru ВА.
PHDB picks up the various signals, and after The sums of B1 and B3, and the sums of B2 and
passing them through a filter choke to eliminate B4 are sent to their respective OP amps (Z2) where
the 620MHz spurious signal generated by the laser they are amplified about 17dB, then output as
tube, outputs them to HEDA. FOCS А and FOCS B signals. Tracking controi
The FM signal is amplified by about 20dB by signals À and C are input to the voltage-follower
the negative feedback amp. Transistors Q1 and Q2 type OP amp 71, and extracted as TRKG A and
form a cascade connected amplifier stage, and Q3 ТЕКС B output signals.
HEAD AMP.
В,
| + + Amp a - FOCSB
| DETECTOR |
4—] amp = = 0 FOCS A
Amp E Emiter —O RF OUT
follower
|
Negative feedback amplifier
Voltage-
follower Е ТАКС А
Vottage- =
follower P тако в
ЯРАМ BLOCK DIAGRAM
Fig. 1
RFAM block diagram

5.2 VDEM (VSOP)
With the UA5002 DOC processor and the
UA5001 video processor IC, the VDEM section
which occupy 1/3 of the VSOP board handles
video signa! demodulation and 1H delay video sig-
nal demodulation plus video signal switching when
dropouts occur. А block diagram of the VDEM
section is shown in Fig. 2.
The video and audio FM signals applied to the
VSOP board from the RFAM board are applied to
the RF correction circuit (Q201- Q203). Since
the electrical conversion frequency response in the
optical system is lower at the inner circumference
than аї the outer circumference, there is a certain
amount of gain compensation up to frame number
#13500 (approx), especially in the high frequency
region where the effect is much greater.
Following compensation of the gain difference
between inner and outer circumferences, the FM
signal is passed to the AUDX board and to the
UA5002 DOS RFIN terminals. This signal is also
passed through a bandpass filter for video FM sig-
nals, and then through an audio FM signal trap in
order to extract the video FM signal components.
After being applied to pin 24 of ПА5001, this FM
signal is amplified by Q208 and Q220, detected
(level detection), and then applied as the RF sensor
output to UM3002 in the SPDL section. Further-
more, the video FM signal delayed by an interval of
1H by the 1H delay line is applied to pin 7 of the
UA5002 DOC processor.
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Function
explanatory
diagrams
for
each
func-
tion
block
in
UA5001
are
outlined
in
Fig.
3.
And
waveforms
on
each
terminals
are
shown
in
Fig.
4.
After
aligning
the
amplitudes
of
the
video
FM
signals
applied
to
pin
24
by
internal
limiter,
an
output
signal
is
obtained
from
pin
29
(with
an
external
resistor
serving
as
the
load),
this
signal
consisting
of
a
frequency
(16MHz)
twice
that
of
the
carrier
signal
added
to
the
video
signal.
How-
ever,
since
this
signal
has
not
yet
been
passed
through
the
de-emphasis
stage,
the
high
frequency
components
will
still
be
raised.
The
video
signal
detected
in
the
discriminator
is
passed
through
a
4.2MHz
lowpass
filter
before
being
applied
to
the
pin
21
video
amplifier
where
the
gain
is
about
31
to
32dB.
The
amplified
video
output
signal
appear-
ing
at
pin
19
is
passed
through
a
220ns
delay
line
and
then
applied
to
the
next
DOS
switch.
(In
this
model,
the
video
signal
is
also
applied
to
the
SPDL
section
after
the
220ns
delay
line)
This
DOS
switch
includes
2
inputs
—
pin
18
for
the
main
line
video
signal
input,
and
pin
16
for
the
1H
delay
video
signal
input,
plus
pin
14
for
the
“DOS”
switch
control
signal.
The
output
appears
at
pin
10.
The
pin
18
input
appears
at
the
pin
10
output
when
pin
14
is
at
L
level,
while
the
pin
16
input
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Fig.
З
UA5001
block
diagram
PR-8210-A
appears
at
pin
10
instead
when
pin
14
is
at
H
level.
The
DOS
switch
output
is
passed
through
the
de-emphasis
stage
and
is
then
applied
to
CPCB
board
and
a
synchronizing
separator
circuit.
The
CPCB
board
is
a
feed
forward
circuit
which
con-
trols
phase
of
chroma
components
in
the
video
signal,
and
serves
to
eliminate
color
bands
and
color
irregularities
in
the
picture.
In
addition
to
separating
the
synchronization
signal,
the
synchro-
nizing
separator
circuit
also
includes
a
noise
can-
cellation
function.
Any
noise
components
exceed-
ing the
input
video
signal
sync
tip
level
in
the
negative
direction
by
more
than
about
0.5V
is
not
accepted
as
a
synchronizing
signal,
and
is
not,
therefore,
included
in
the
synchronizing
separator
signal
output.
In
addition
to
triggering
the
internal
MMV,
this
synchronizing
separator
output
signal
appears
at
pin
6
as
a
composite
synchronizing
signal
output.
In
this
model,
this
composite
synchronizing
signal
is
applied
to
the
V
synchronizing
separator
where
a
signal
is
generated
(and
applied
to
the
SPDL
sec-
tio)
in
order
to
cover
the
V
blanking
interval
of
about
15H
from
the
vertical
synchronizing
signal.
If
the
FM
signal
level
is
not
detected,
however,
this
composite
synchronizing
signal
is
inhibited.
TL
b
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or:
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ur
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Fig.
4
UA5001
waveforms
on
each
terminals
11

PR-8210-A
The
MMV
triggered
by
the
composite
syn-
chronizing
signal
generates
a
clamp
pulse
for
keyed
clamping
of
the
input
video
signal
applied
via
pin
9
from
the
CPCB
board.
This
clamp
pulse
is
also
employed
as
the
UA5002
clamp
pulse.
The
clamp-
ed
video
signal
is
passed
via
switches
P1,
P2
and
P3,
the
output
appearing
at
pin
1.
At
the
P1
switch,
the
video
signal
is
switched
to
a
signal
of
half
the
video
level
by
a
display
back-
ground
signal,
The
P2
switch
switches
the
video
sig-
nal
and
the
character
signal
with
white
level,
and
in
this
case,
the
switched
character
white
level
can
be
adjusted
by
the
voltage
applied
to
pin
17.
The
P3
switch
is
involved
in
video
squelching
and
switch-
ing
of
the
video
signal
with
the
P4
switch
output.
When
using
CAV
discs,
switch
P4
applies
the
com-
posite
synchronizing
signal
{о
pin
7
for
“soft
clamping”
purposes,
and
extracts
the
signal
again
when
the
input
level
on
pin
2
of
the
P3
switch
is
changed
to
L
level.
The level of the MCA code which exists within
the V blanking interval of the video signal output
from pin 1 is suppressed by 70%. The reason for
this
is
to
prevent
the
appearance
of
the
MCA
code
in the screen during the fly-back period in certain
types of TV sets. This operation is inhibited during
video squelching.
Fig. 5 ЏА5002 block diagram
12
Fig. 5 outlines the internal functional blocks in
the UA5002 DOC processor, and also an example
of general application. The delayed video signal
applied to pin 7 via the 1H delay line is demodu-
lated by a discriminator circuit (of same composi-
tion as the discriminator circuit in the UAS001)
with an external resistor connected to pin 12 serv-
ing as the load. As can be seen from the discrimi-
nator stage signal waveform diagram, the frequency
component with a frequency twice that of the
carrier frequency is still included in the signal at
this stage, but is eliminated by a low-pass filter
connected to the load resistor.
der rM.
wA We س󰾯
PANAN 4» e
"P [уу ра оох
ET и
is ros qe КИ
ви за RED
eos ШЫГ] T
Fig. 6 Waveforms at UA5002 each terminals

Ihe video signal applied to the amplifier con-
nected
tu
pin
16
is
amplified
by
about
30dB
in
order
to
obtain
a
video
signa!
of
the
required
level
from pin 14. and since this signal has not been
passed through a de-empha:
frequeney region of tho sigr
sis stage yel, the high
lis boosted as shown
in the signal waveform diagram. This signal is ap-
plied to pin 16 of UAS001 for compensation pur-
poses when drop-outs are generated.
The
FM
signal
app
to
pin
18
is
also
applied
to
the
limiter
and
then
retriggers
the
retriggerable
MMV
1.
During
this
retriggering
action.
the
MMV1
output
is
maintained
at
Г.
level,
resulting
in
the
MMV2
output
also
becoming
L
level.
If.
however,
а
drop-out
exists
in
the
input
FM
signai,
the
MMV1
retriggering
action
stops,
and
the
ММУ?
is
con-
sequently
triggered.
This
results
in
а
DOS
signal
5-3 AUDX
Following
compensation
for
level
differences
between
the
inner
and
outer
tracks
Бу
the
RF
correction
circuit
in
the
VDEM
stage,
the
RF
signal
is
passed
to
the
АСОХ
board
which
includes
the
audio
FM
detectors,
the
output
selector
switches,
and
the
CX
noise
reduction
system
decoder.
(See
block
diagram
in
Fig.
7
below.)
The
RF
signal
applied
to
pin
1
of
the
AUDX
board
is
first
applied
to
a
low-pass
filter
where
the
video
FM
signal
is
removed,
the
RF
signal
then
being
amplified
by
about 37dB.
The
1Лей
and
2jright
channel
audio
FM
signals
which
serve
as
the
respective
frequency
carrier
signals
are
ex-
tracted
by
2.3МН2
and
2.8MHz
band-pass
filters,
and
subsequently
passed
to
the
FM
detector
stage
(a
quadrature
detector
utilizing
PA30014A).
Ud
pe
PR-82810-A
output
of
constant
width
rrom
pin
1.
The
resistor
and
capacitor
connected
to
pin
21
are
used
in
deciding
the
MMV1
output
pulse
width
iie.
the
detected
drop-out
width).
while
the
resistor
and
capacitor
connected
to
pin
22
determine
the
ММУ?
output
pulse
width,
i.e.
the
width
of
the
pulse
added
to
the
drop-out.
The video output signal from pin 10 of
UAğ5001 is passed through the de-emphasis stage,
and then applied to the CPCB board. This signal is
also applied to pin 5 of 15002 in order to extract
the phillins code present in the vertical blanking
interval. This video signal is then synchronized and
clamped by the clamping pulse applied to pin 2,
sliced by the DC voltage applied to pin 13, and
then appears at the pin 3 output only while the
DATAENABLE signal applied to pin 4 is at L level.
These demodulated audio signals are applied to
respective switching circuits via the audio output
level
setting
controls
ҮКІ
and
VR2.
When
the
AUDI and AUD signals from the CONT board
are
applied,
S1
and
$2
are
switched
on
and
$3
switched
off,
resulting
in
the
1Леѓ
and
2/right
channel
output
signals
appearing
at
the
switching
circuit
outputs
(A)
and
(В)
respectively.
If,
how-
ever, the AUDI (or AUD2) signal is not received
from the CONT board, S2 (S1) and $3 are switch-
ed
on
and
51
(52)
switched
off,
resulting
in
the
2/
right
channel
signal
appearing
at
both
switching
circuit
outputs
(A)
and
(B).
Апа
if
neither
the
AUDI
пог
AUD2
input
signal
is
received,
51
and
S2
are
switched
off
and
53
switched
on,
thereby
preventing
either
channel
signal
from
appearing
at the (A) and (B) outputs.
227
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Fig.
7
AUDX
Block
Diagram
13

PR-8210-A
An
audio
squelch
is
used
to
suppress
the
noise
level
in
the
audio
output
at
times
when
the
level
of
the
detector
input
FM
signal
is
low
(such
as
when
the
player
is
first
started).
In
this
case,
81
and
82
are
switched
off
and
S3
switched
on
by
using
the
PA3001A
AGC
output
without
involving
the
AUDI
and
AUD2
signals
from
the
CONT
board.
The
audio
signals
appearing
at
the
switching
circuit
outputs
(A)
and
(B)
are
passed
through
respective
75us
de-emphasis
circuits
(R18:C14
and
В39:С40)
before
being
applied
to
the
CX
noise
reduction
decoder.
This
CX
noise
reduction
system
reduces
unwanted
noise
by
compressing
the
dynamic
range
during
recording
and
expanding
it
again
during
playback.
This
system
was
originally
developed
by
the
CBS
Research
Laboratories
for
noise
reduction
in
LP
records,
and
has
now
been
modified
for
use
in
video
discs.
Tne
dynamic
range
compression
and
expansion
characteristics
of
this
system
are
dependent
upon
the
following
four
conditions.
(1)
The
compression
and
expansion
actions
must
have
no
effect
on
the
audio
frequencies.
(2)
The
levels
(in
dB)
of
signals
greater
than
—28dB
(with
reference
level
of
04В)
must
be
compressed
linearly
in
a
proportion
of
2:1,
and
the
level
of
signals
greater
than
—14dB
must
be
expanded
in
a
proportion
of
1:2.
(3)
The
frequency
of
signals
compressed
and
ex-
panded
must
be
at
least
500Hz.
(4)
The
compression
/expansion
control
signal
is
to
employ
a
variable
time
constant
circuit
which
varies
according
to
audio
amplitude
level
changes.
The
block
diagram
of
the
CX
noise
reduction
compressor
stage
is
outlined
in
Fig.
8,
the
circuit
composition
being
the
reverse
of
the
CX
expander
stage
shown
in
the
block
diagram
in
Fig.
7.
Relia-
bility
of
these
circuits
is
ensured
by
using
the
same
circuit
for
the
compressor
feedback
circuit
and
the
expander
feed
forward
circuit.
In
the
compressor,
the
input
signal
is
passed
to
a
VCA
where
part
of
the
output
is
passed
through
а
high-pass
filter
for
peak
detection,
resulting
in
a
DC
voltage
being
generated
at
the
output
of
the
time
constant
network.
This
DC
voltage
is
con-
verted
to
a
current
by
the
V-I
converter,
the
VCA
amplification
being
controlled
by
the
size
of
the
current.
The
output
level
therefore
varies
accord-
ing
to
the
input
signal
level.
The
compression/ex-
pansion
characteristics
of
the
CX
NR
system
fora
1kHz
signal
are
outlined
in
Fig.
9.
14
Fig.
8
CX
NR
system
connesso:
block
diagram
OUTPUT
ie
Fig.
9
CX
NR
system
compression/expansion
characteristics

With
40%
modulation
(frequency
deviation
+
40kHz)
as
the
system
reference
level
(OdB),
signals
with
a
level
greater
than
—28dB
are
subjected
to
1:2
logarithmie
compression.
Signals
of
lower
level
are
not
compressed.
The
basic
attack
time
determined
by
the
time
constant
network
used
by
the
compressor
and
ex-
pander
is
1ms
for
sudden
large
increases
in
ampli-
(аде,
and
30ms
for
more
gradual
large
amplitude
increases.
The
recovery
time
is
200ms
for
decreases
of
large
signals,
while
the
attack
and
recovery
time
for
small
signal
amplitude
changes
15
2
seconds.
The
demodulated
audio
signals
passed
through
the
7545s
de-emphasis
circuit
are
applied
to
current-
controlled
variable
gain
amplifiers
(consisting
of
77).
Part
of
the
de-ernphasis
output
is
also
passed
through
a
500Hz
high-pass
filter
(C61/R75
and
С69:880),
amplified
by
Z5
11/4)
and
25
(3:4),
and
rectified
by
the
full-wave
rectifier
consisting
of
25
(9:4),
D2,
D3,
and
Z5
(4/4),
D4,
05.
Due
tc
the
forward
characteristics
of
the
diodes,
this
rectifier
circuit
has
a
dead
zone
which
ensures
that
signals
below
*
0.6V
do
not
appear
at
the
output.
With
this
circuit
composition,
the
expander
gain
for
input
signals
below
—14dB
(reference
value)
can
be
kept
at
a
constant
value
of
--14dB.
Following
mixing
of
the
rectifier
outputs,
bias
is
applied
by
Q13,
D1
and
R83
and
addition
to
D2-D5
temperature
compensation.
This
output
is
then
received
by
the
Q14
emitter-follower
while
also
being
subjected
to
a
DC
shift.
The
emitter-
follower
output
is
applied
to
the
circuit
formed
by
76
(1/4),
D6,
R85,
R86
and
C63
for
peak
level
detection
and
smoothing
purposes.
This
circuit
has
an
attack
time
of
lms
and
a
recovery
time
of
10ms.
The
filter
output
is
then
applied
to
a
time
constant
network
via
the
Z6
(2/4)
voltage-follower.
PR-8210-A
The
attack
time
of
30ms
in
this
circuit
is
deter-
mined
by
D7,
R87
and
C65,
while
the
recovery
time
of
200ms
is
determined
by
D8,
R89
and
C65.
However,
due
to
the
dead
zone
formed
by
the
for-
ward
characteristics
of
D7
and
D8,
the
attack
and
recovery
times
for
small
level
changes
are
deter-
mined
by
R88
and
C65,
the
value
being
2
seconds
for
both
times.
The
ourput
is
then
passed
to
the
Z6
(3/4)
volt-
age-follower
and
76
(4/4).
C64,
R90
and
R92
form
a
high-pass
filter,
the
output
being
applied
to
the
915
emitter-follower
(which
сап
also
be
соп-
sidered
a
positive
voltage
half-wave
rectifier
with
a
0.7V
dead
zone).
This
circuit
operations
in
con-
junction
with
the
D7,
R87,
C65
circuit
in
achieving
an
attack
time
of
ims
for
sudden
increases
in
high
level
signals.
The
output
from
this
time
constant
network
is
applied
to
a
V-I
converter
formed
by
Z6
(4/4)
and
Q16.
The
Z7
gain
is
controlled
by
the
Q16
collec-
tor
current,
resulting
in
CX
expander
input/output
characteristics
as
shown
in
Fig.
9.
15

PR-8210-A
5-4 FOCUS SERVO
Due io ihe ingenious combination of cylindri-
cal lens and. 1-way divider photo-detector, the laser
beam reflected from the dise into the photo-detec-
tor mounted ou the slider results in the generation
Xu focus error signal where the variation between
output level and rhe distance between the objective
ler describes an S curve. By utilizing the
linear section of this focus error signal variation
curve 13 curve), changes in the distance between
the object lens and the dise сап be detected апа
employ а focus servo mechanism. After this
focus error signal is amplified in the RF AM board
and processed in the УЗОР, it is further amplified
tcurrent amplification) in the SYPS board in order
to drive the focus motor. In this way the focus
motor {objective lens) is operated to maintain
focussing error constantly at zero, thereby ensuring
that the laser beam is accurately focussed on the
disc at all times.
When starting, the objective lens is first raised
(as a result of the FOCUS ON command from the
CONT board) to a position where the focus servo
сап be applied. and once the beam is properly
focussed ("in focus") the focus servo loop is closed
and d
ed i
and
а
FOCUS
LOCK
command
output
is
sent
te
the
CONT
board.
The
focus
servo
is
thus
set
to
normal
operating
status.
but
if
proper
focussing
cannot
be
achieved
within
1
sec
after
the
applica-
tim
of
the
FOCUS
ON
command,
this
command
signal
will
Бе
stopped
temporaril
sing
operation
retried
4
times.
Ef
i
sand the focus-
is sll not pos-
sible
to
lock
the
focus
serve
mechanism,
the
player
is switched automatically te reject mode
Starting operation
The
focus
servo
mechanism
block
diagram
is
outlined
in
Fig.
10
and
the
timing
sequence
chart
is
shown
in
Fig,
11.
Until
the
PLAY
key
is
pres
after
switching
the
power
oa.
the
FOCUS.
ОЎ
Input
command
is
no!
applied.
And
with
the
аррисапов
of
the
L
level
output
from
the
Q5
inverter,
the
Q2
analog
switch
remains
off.
The
Q8
inverter
output
is
likewise
kept
at
L
level;
and
a
DC
voltage
of
approximately
—-30mV
is
applied
to
the
Z2
(1
2)
driver
amplifier
input.
thereby
keep-
ing
the
focus
motor
pulled
downwards.
The
Q4
Inverter
output.
on
the
other
hand,
keeps
the
Q6
QT
loop
thp-flop
output
at
L
(Q6)
and
H
(Q7)
levels.
-[ ZERO
+ | CROSS
+ |СЕТЕСТОН
GE
NE
де
FOCS
ON
»
=
pd
1008
ON
Oris
px
EE
COSLOCK.O
АА.
Кен
an
^
GY
VV
в
Б
Е
«у
cs
t
|
|
|
E
|
је
|
TRKG
A
2
у
=
е
|
TRKG
B
|
+
t
4
то
t
t
f
UMA4CCA
PIN
21
Fig. 10 Focus serve block diagram
16

When the PLAY key is pressed, the FOCUS ON
command from the CONT board is applied to the
VSOP board, while at the same time, the LASER
ON command is applied to the LSPS board, result-
ing in the laser generator being switched on. Due to
the application of the FOCUS ON command the
Q5 inverter output is switched to H level, resulting
in this output combining with the Q7 H level out-
put to turn the Q2 analog switch on. And due to
the QS output. 53 is inverted and а *30mV DC
voltage is applied to the Z2 (1/2) input. The circuit
constituted Бу D7, 18. and C11 is for applying a
pulse differentiated by a time constant of СІІ,
R52 and R53 to Z2 (1/2). and overates for de-
creasing a static frictional forse of the focus motor
while beginning of the focus motor raising opera-
tion, and also increasing a focus motor torque
lowered by unbalanced focus bridge. This *30mV
DC voltage is amplified in Z2 (1/2) in order to raise
the focus motor to the required position. The
counter electromotive force appearing between the
focus motor terminals at this time as detected
(level detection) by the Z2 (2/2) counter electro-
motive force detector circuit via a bridge circuit,
and is then applied to the Z2 (2/2) amplifier as a
negative feedback signal. The focus motor can thus
be raised at a constant velocity.
When the focus motor is raised to about 60
um below the proper focusing position, tracking
error will commence to appear. This tracking
error is generated in А and B forms, and appears as
an output from the КРАМ board. These signals are
added and applied to the Z3 (1/2) dise sensor com-
parator input. Phe output from the Z3 (2/2) zero-
Cross detector is an H level output, and increases
the disc sensor comparator threshold level in the
(+) direction. When the tracking error level is in-
creased to a value in excess of the threshold level,
the output of Z3 (1/2) is switched to H level. The
reason [юг increasing the disc sensor comparator
threshold level at this time is to eliminate the
effect of the reflected beam from the dise surface
(protective plastie surface).
When the objective lens is raised further, focus
error is generated, resulting in À and B focus error
signals from the RF AM board being applied to the
Zl (1:2) differential amplifier input. The focus
error appearing at the output of the Z1 (1/2) am-
plifier is applied to the zero-cross detector (—)
input. If the objective lens is raised still further, the
focus error change will reach the non-linear section
of the S-shaped curve, and at the point where the
threshold level determined by the (+) input voltage
is exceeded, the detector output will be switched
to L level. The loop flip-flop outputs Q7 and Q6
will thus be switched to L and H levels respectively,
Fig. 11 Focus servo timing chart
thereby closing the Q1 loop switch, and resulting
in the closure of the focus servo.
At the same time, the zero-cross detector thres-
hold level is raised in the (+) direction, and the disc
sensor comparator threshold level is reduced by
about *0.2V, followed by the FOCUS LOCK com-
mand signal being sent to the CONT board. Апа
thereafter, the focus servo mechanism is in normal
operating mode.
Normal Operation
Focus error A, B is amplified by a differential
amp consisting of Z1 (2/2). УҢ] serves as the
overall voltage adjustment for focus offset caused
by the RFAM section DC offset voltage, photo
detector sensitivity corrections, slight deviations
from the optical focus point, and other factors.
The focus error that appears in the output of
Z1 (1/2) passes through VR2 to set the loop gain
and then enters the AGC circuit. When the loop
gain is raised above the level normally required,
noise generated in the system is caused by the in-
creasing amount of static generated by the focus
motor. Also, the system becomes susceptible to
17
PR-8210-A

PR-8210-A
defocusing
due
to
tracking
mirror
movements
during
scanning
and
other
similar
operations.
However,
when
the
gain
is
small,
it
is
possible
that
the
focus
offset
voltage
will
not
be
able
to
keep
up
with
the
focus
servo
(the
input
dis-
turbances).
To
prevent
this,
gain
is
automatically
raised
only
when
setting
the
loop
gain
so
that
VR2
has
a
stable
and
sufficient
gain
at
the
same
time
there
is
а
great
deal
of
disturbance
in
the
AGC
circuit.
This
operation
is
performed
by
01.
D2
and
72.
C2.
and
ВЭ
in
reverse
parallel
connection.
22
(2:2)
forms
an
equalizer
to
stabilize
the
‘oop.
During
standard
operation,
the
loop
switch
is
‘eft
on
by
Q1.
and
the
focus
error
is
amplified
by
the
drive
amp
as
controlled
by
Z2
(1/2).
Аз
de-
scribed
earlier,
the
output
of
this
drive
amp
is
eur-
rent
amplified
in
the
SYPS
amplifier
and
drives
the
focus
motor.
5.5
TRACKING
SERVO
AND
SLIDER
SERVO
The
major
component
in
the
tracking
and
slider
servo
systems
is
the
UM4004
ТЕКС
IC.
See
the
block
diagram
in
Fig.
12.
The
photo-detector
outputs
from
both
sides
of
the
center
segments
divided
in
4
parts
on
the
slider
are
amplified
by
the
RFAM,
and
then
applied
to
N4-7
and
N4-8
in
the
VSOP
board.
The
difference
between
these
signals
is
extracted
in
Z4
(1/2)
and
is
applied
to
Z4
(2/2)
as
the
tracking
error.
Q10
FROM FOCUS SERVO
forms
part
of
the
Z4
(2/2)
feedback
loop,
and
due
to
the
slider
potentiometer
output
the
change
in
resistance
across
the
D-S
interval
is
practically
linear
from
the
inside
to
the
outside
circumference
of
the
disc.
Consequently,
the
loop
gain
at
the
out-
side
disc
track
is
increased
approximately
4dB
compared
with
at
the
inside
dise
track.
The
track-
ing
error
amplified
by
Z4
12.2)
and
compensated
for
level
differences
between
inside
and
outside
tracks
is
applied
to
UM4004
via
VRS.
This
VR
control
is
used
to
ensure
optimum
loop
gain
adjust-
ment
for
the
tracking
servo.
The
major
components
incorporated
in
UM4004
are
described
below
in
a
little
more
detail.
AMPI
and
AMP?
form
the
tracking
servo
op.
amp.
stage.
while
switch
1
operates
as
the
servo
loop
open
se
switch.
The
loop
is
open
when
the
switch
is
on.
and
closed
when
the
switch
is
off.
AMP?
and
AMP.
form
the
slider
servo
op.
amp.
stage
with
switch
2
serving
as
the
servo
ioop
open;
closed
switch.
The
ioop
F.F.
circuit
opens
and
closes
the
loop
by
controlling
switches
1
&
2.
[here
are
3
comparators.
COMP1
detects
the
zero
cross-point
of
the
tracking
error
signal
for
determining
the
loop
closing
timing.
COMP2
is
a
window
comparator
which
is
applied
an
input
vol-
tage
corresponding
to
the
degree
of
rotation
in
the
TRKG
mirror,
and
is
used
in
limiting
the
mirror's
field
of
vision.
COMP3
is
not
used
in
this
model.
à
TRKG
а
Og
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iocus
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К
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TRKS
OFFSET
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4004
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|
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Fig.
12
Tracking
&
slider
servo
block
diagram
18

4'
There
are
also
3
MMV
components.
MMVI
is
triggered
by
a
jump-back
trigger
signal
from
the
CONT
board,
and
sets
the
jump
F.F.
by
generating
pulse
outputs
of
approx.
1004s.
ММУ2
is
triggered
by
a
pulse
corresponding
to
the
zero
cross-point
of
the
tracking
error.
Since
MMV2
is
а
re-trigger
type
component
with
an
output
pulse
width
set
to
about
100из.
an
L
ievel
output
will
be
maintained
without
inversion
while
ihe
trigger
pulse
repetition
frequency
is
more
than
10КН2.
MMV3
is
triggered
by
the
output
of
the
window
comparator
in
the
previous
stage.
resulting
in
the
generation
of
out-
put
pulses
of
about
5ms
:n
width
which
serve
as
resetting
signals
for
the
loop
Е.Р.
in
the
next
stage.
Pin
No.
Lis
for
jump
pulse
outputs
generated
when
the
jump
F.F.
in
the
next
stage
is
set
by
the
MMV1
output.
Although
the
output
pulse
polarity
js
determined
by
the
SCAN
C
signal,
only
the
—6.6V
output
is
obtained
in
this
model,
Pin
No.
12
is
for
the
DC
outputs
employed
to
drive
the
slider
during
scan
mode.
There
are
5
output
voltages
altogether.
viz
+6.6\.-
6.6V
(high
scan),
*3.3V,
—3.3V
(low
scan)
and
OV,
and
these
are
controlled
by
the
SCAN
А.
SCAN
B
and
SCAN
C
input
signals.
Start
of
initial
tracking
operation
from
set
up
mode:
When
the
PLAY
key
is
pressed,
there
is
a
FOCUS
ON
command
output
from
the
CONT
board,
resulting
in
the
start
of
focussing
by
the
PLAY FOCUS TRKG
KEY-IN ON SLO f CLOSE
FOCUS ON
SCAN A
SCAN B [ыы ome 5
SCAN C
PIN 12
FOCUS LOCK |
: DELAYED BY А
i TIME CONSTANT
4 C12 R74
12V
PIN 211М
TRKG
ERROR
Fig. 13 Initial tracking operation timing chart
PR-8210-A
focus
servo
mechanism.
At
the
same
time,
the
slider
is
moved
initially
in
the
forward
direction
by
the
SCAN
A
and
SCAN
C
commands
in
order
to
locate
the
inside
start
position.
After
a
delay
of
about
0.5
sec.
following
the
FO
LOCK
com-
mand
from
the
focus
servo
mechanism,
an
input
voltage
is
applied
to
pin
21
of
UM4004,
thereby
switching
the
internal
F.F.
to
enable
status.
And
at
approximately
the
same
time,
a
tracking
error
sgnal
is
applied
to
pin
27,
resulting
in
COMP)
being
inverted
by
the
zero
crosspoint
of
that
sig
This
is
followed
by
triggering
of
MMV2.
and
100us
later,
the
gering
of
the
loop
P.F..
result-
ing
in
the
tracking
and
slider
servo
mechanisms
being
closed.
See
Fig.
13
for
an
outline
of
the
time
chart
of
this
initia!
tracking
operation.
Scanning operation:
The
time
chan
tor
the
scanning
operation
is
outlined
in
Fig.
14.
When
the
SCAN
REV
key
в
pressed.
SCAN
A
iL}.
SCAN
В
(Н)
and
SCAN
©
tL)
commands
from
the
CONT
board
are
applied
to
the
UM4004,
resulting
in
switch
2
being
turned
on
by
the
internal
scan
logic.
and
the
slider
servo
thus
being
made
“open
loop”.
At
the
same
time,
а
—3.83V
output
voltage
appears
at
pin
12.
This
vol-
tage
is
inverted
and
amplified
by
AMP4,
resulting
in
the
slider
being
shifted
in
the
reverse
direction.
p— — SCAN REV — —31
DEPRESS RELEASE
|
' '
SCAN А
SCAN В
SCAN C اف ا󰾯
PIN 12 OUT
OPEN
۴ کار
PIN 6
STOPPER
IN
(TRKG ERROR)
Fig. 14 Scanning operation timing chart
ла

PR-8210-A
Tracking
Eror
Mirror rotat.on |
Center point
Following track
Stoope* contact L
ол. са OL
us
Xs es %;
opens
= returns 10
ти
center pos: tion
Fig. 15 Tracking mirror operation during scan mode
Although
tracking
of
the
dise
track
is
continued
while
the
mirror
inclination
is
increased.
the
track-
ing
error
DC
component
is
also
increased,
and
when
the
input
voltage
applied
to
pin
6
exceeds
+0.6V.
the
window
comparator
is
activated
and
MMV3
triggered.
The
loop
F.F.
turns
switch
1
on
during
the
5ms
interval
corresponding
io
the
MMV3
output
pulse
width,
resulting
in
the
track-
ing
servo
being
made
"open
loop".
During
this
period,
the
mirror
returns
to
the
center
position,
the
loop
F.F.
is
set
by
the
ММУ?
output
pulse,
and
switch
1
is
turned
off
(i.e.
the
tracking
servo
15
switched
to
“closed
loop").
Ге
movement
of
the
ТЕКС
mirror
during
scan
mode
is
outlined
in
Fig.
15.
The
above
operation
is
repeated
con-
tinually
during
scan
mode,
but
as
soon
as
the
SCAN
key
is
released,
the
tracking
and
slider
servo
mechanisms
are
switched
back
to
"closed
loop"
for
normal
operation.
During
stillstep
and
slow
motion
playback
modes,
jump-back
trigger
is
also
applied
to
the
UM4004
together
with
the
SCAN
A
(H),
SCAN
B
(L)
and
SCAN
С
(L)
commands
from
the
CONT
board.
Although
the
output
pattern
of
this
jump-
back
trigger
differ
according
to
the
type
of
play-
back
mode,
it
is
generated
during
the
v
blanking
under
Philips
code
control.
(See
the
list
of
sig-
nals
in
the
table
referred
to
during
the
description
of
the
CONT
board).
ММУ1
is
triggered
by
the
jump-back
trigger
applied
to
pin
16.
This
is
then
followed
by
the
generation
of
а
-6.6V
jump-back
pulse
signal
from
pin
1
by
the
jump
F.F.,
while
at
the
same
time
the
loop
F.F.
is
also
reset,
resulting
in
the
tracking
20
servo mechanisms being switched to "open loop”.
Тһе jump-back pulse output signal from pin 1 is
differentiated. level-adjusted. by УВВ, and then
applied to AMP2.
The laser beam traverses the tracks as indicated
in the time chart Fig. 16 and moves to an inter-
mediate
point
between
one
track
and
the
next.
When the tracking error intersects the zero cross-
point in the positive direction, the pin 1 jump-back
pulse output returns to OV resulting in the tracking
loop being closed, and the differentiated DC vol-
tage
being
applied
to
the
AMP2
input
in
a
direction
which
will
suppress
the
inertial
movement
of
the
mirror.
PN 16
JUMP BACK TRIG iN Lf
PIN 1
JUMPBACK OUT
PIN 4 |
AMP 2IN
PIN 27 14045
TRKG ERROR IN џ 2
А ~
> ۲ `
BEAM SPOTS
ON THE DISC о
‘ + + 4
TRACK А А Ac А-1
Fig. 16 Jump back operation timing chart