Browse Prior Art Database

Laser Holder with Five Degrees of Adjustment

IP.com Disclosure Number: IPCOM000103831D
Original Publication Date: 1993-Feb-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Bargerhuff, RA: AUTHOR [+2]

Abstract

In optical data storage devices, the laser must be aligned relative to the rest of the optical components in regards to three translations and two angles (three angles in Direct Read After Write, or DRAW. The collimating lens is typically translated along the Z-axis coordinating system in the figure for aligning one degree of freedom, or DOF. The remaining DOFs are commonly adjusted by shimming a heatsink block holding the laser and/or shimming the entire optical head. This approach does not allow for assembly automation and has its adjustment resolution limited to the available shim stock. A better method is shown in the figure. The laser is heatsunk to a partial spherical shell that is then loaded against a base by a flat spring.

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Laser Holder with Five Degrees of Adjustment

      In optical data storage devices, the laser must be aligned
relative to the rest of the optical components in regards to three
translations and two angles (three angles in Direct Read After Write,
or DRAW.  The collimating lens is typically translated along the
Z-axis coordinating system in the figure for aligning one degree of
freedom, or DOF.  The remaining DOFs are commonly  adjusted by
shimming a heatsink block holding the laser and/or shimming the
entire optical head.  This approach does not allow for assembly
automation and has its adjustment resolution limited to the available
shim stock.  A better method is shown in the figure.  The laser is
heatsunk to a partial spherical shell that is then loaded against a
base by a flat spring.  The X and Y translations are accomplished by
sliding the base against the optical head's housing.  All angular
manipulations are done by rotating the power receptacle that mounts
to the laser leads while the heatsink shell is being lightly biased
against a ring within the heatsink shell is being lightly biased
against a ring within the base.  When the laser is aligned properly,
the entire assembly is attached to the optical head housing by screws
which also load the flat spring tightly against the heatsink shell.
This loading causes the laser to be clamped into its aligned
position.

      While the heatsink shell and base may also be a more standard
ball-and-socket design...