Compensation method of push-pull tracking servo offset of optical disk drives.

Yoshimoto, Kyosuke; Ito, Osamu; Tanaka, Kunimaro

doi:10.3169/itej1978.44.1398

Cited by 1 publication

(1 citation statement)

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“…To compensate for misalignment of optical assembly, several studies have proposed methods for correcting servo signal offset due to optical misalignment over time (Yoshimoto et al, 1990;Nakai et al, 2013). Those methods involve subtracting additional values, such as an average servo signal level during track jump and an imbalance in light intensity on the detector, from the servo signal itself.…”

Section: Introductionmentioning

confidence: 99%

Heat- and humid-proof adhesive joints for optical pickup

Ochi

Kitada

Konishi

2019

JAMDSM

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Our previously proposed method for arranging adhesive joints for an optical assembly was adopted to resist long-term exposure to severe environments. This method is expected to passively compensate for permanent optical misalignment due to long-term exposure to hot and humid conditions by arranging the bonding direction and position of each optical component in order to tend to displace or tilt a desired amount in a desired direction over time. We calculated the beam spot deviation on a detector, which is an indicator of misalignment of the optical assembly due to heat, humidity, and time effects on adhesive joints. We arranged to adhesively bond the laser diode to the holder from the top so that the laser diode could be lifted up due to the moisture expansion of the adhesive joint over time. The developed adhesive joints arrangement had a great advantage in that upward displacement of the laser diode compensates for beam spot deviation caused by tilt of the prism and displacement of the detector along the warp deformation of the housing. The calculated and measured results showed that the beam spot deviation was within about ±5 % after the optical pickup was left at 60 °C and 90 %RH for 336 hours. It is concluded that our method for arranging adhesive joints of each component effectively compensates for passively permanent optical misalignment that occurs after long-term exposure to hot and humid conditions.

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Section: Introductionmentioning

confidence: 99%