Attachment. Optical Power Measurement - LG RH178H Service Manual

7. ATTACHMENT. OPTICAL POWER MEASUREMENT

Optical Power measurement is to adjust LD power from Pick-up
To measure optical power, LD status is on. Other light affects to optical power.
Avoid other light to measure exact power
Generally headlight power is about 50µW, Sun power is about 100mW.
Optical Power measurement method
1. Fit optical Power Meter λ(wavelength) value to DVD.(generally 660nm)
2. DVD LD On.
3. Approach power sensor to Pick-up Lens about 3mm vertically. Fix Lens and Sensor
4. Read Monitor value. (move sensor read just a little and read max value.)
(caution) unit is mW.
5. Write monitoring value x 100. Only an integer.
6. Fit opticcal Power Meter λ(wavelength) value to CD.(generally 780nm)
7. CD LD On.
8. 3 ~ 5 recheck.
4-30
mark position.
Display Part