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Automatic adjustment is executed every time the disc changes.  (7 to 8 seconds later)
Why?  Because

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reflection rates, etc. differ on different discs

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it absorbs laser power, PD, an optical system changes with the passage of time, etc.

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 of the need to decrease adjustment at the time of production

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While the light doesn’t return the laser condition, the laser and adjusts the TES and FES to
a standard voltage.
(It revises the electric offset on error formation circuits)

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If there are differences in the reception of the PD as shown, even if the focus on the disc is
at optimum condition, error signals do not become “0”.
Therefore, bias is added to the FES signal, then the RF amplitude signal reaches its
maximum, or zitta seeks the best bias voltage to achieve a revised bias voltage.

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Similarly, in tracking, error “0” level revisions are made.
When rotating the disc in the Focus Servo “ON”, Tracking Servo “OFF” and Thread Servo
“OFF” modes, TES shows up due to the polarized core of the disc.  Revise it to make the
voltage of the half of the p-p value to be error “0”.

FES

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Depending on the disc reflection rate, PD sensitivity difference, etc, FES output voltage
changes against a certain amount of focus gap.
For example, if FES becomes 1/2 of the same amount as the focus gap, servo output voltage
reduces to half to revise it.
That means, the gain decreased 6dB.
The method to adjust the gain for this condition is to add a “gairan” of a certain frequency
to the focus servo group, compare the FES and added “gairan” levels phase, and revise the
gain in the servo IC to reach the targeted gain.

FES

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Similarly, gain adjustment is done through the tracking servo system

The TRAHMECHA position is detected by turning on 5 of SW.
However, there are some cases when the position of the TRAYMECHA cannot be detected with
SW input information only.  In such a case, it is possible to specify the position from the condition
of the SW input change when tray motor is rotated one direction or the other.
The following are the input conditions responding to each TRAYMECHA position.
Terms in parenthesis show the condition of switches responding to the tray 2 side.

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Position where SW2B (SW1B) fall is detected while tray discharge is activating.

Both SW2B (SW1B), SW2A (SW1A) are under condition “H”, and during this period
(while the motor is rotating), MECHASW does not change from “H” (while Tray 2 is
in action) or “L” (while Tray 1 is in action).

The position where SW2A (SW1A) fall is detected while the tray is activating.

Note: While Tray 1 is in action, disc reproduction is possible when MECHASW is “L”

and PICKMECHA is on the Tray 2 side.  On the other hand, while Tray 2 is in
action, disc reproduction is possible when MECHASW is “H” and PICKMECHA
is on the Tray 1 side

i

j

i

j

(1) Position of concluded PICKMECHA transfer from the Tray 1 side to the Tray 2 side.

The position where SW2A fall is detected while PICKMECHA is moving from the
Tray 1 side to the Tray 2 side.

(2) Position of PICKMECHA during movement (from either side to the other side)

SW1A, SW1B, SW2A and SW2B are all in “H”, and MECHASW changes from “H”
to “L”, or “L” to “H” during this time (while the motor is running).

(3) Position of concluded PICHKECHA transfer from the Tray 2 side to the Tray 1 side

The position where SW1A fall is detected while PICKMECHA is moving from Tray
2 side to Tray 1 side.

Insert the tray and move it to c: tray close position.  (both Trays 1 and 2)

Insert the tray and move it to c: tray close position.

The current position marks the completion of movement and the treatment is over.

It is the same position as Tray 1 Close, so the movement is complete and the treatment is over.

Rotate the loading motor in the direction of PICKMECHA movement from the Tray 2 side to
the Tray 1 side, then reverse it when MECHASW = “H” is detected.  After that, PICKMECHA
movement is completed from d: Tray 1 side to Tray 2 side.

Move PICKMECHA from the Tray 1 side to the Tray 2 side, then d: move it to the PICKMECHA
completion position from the Tray 1 side to the Tray 2 side.