1. A lens support mechanism comprising:
a semiconductor laser for emitting a laser beam;
an enclosure to which the semiconductor laser is fixed and located;
a lens disposed coaxially with the laser beam emitted from the semiconductor laser;
a first cylindrical member formed in a cylindrical shape so as to fix and locate the lens at the inner surface thereof; and
a second cylindrical member fitted to the first cylindrical member on a side of the lens opposite at the semiconductor laser and formed so as to be fixed to the enclosure;
wherein the second cylindrical member has a linear expansion coefficient substantially the same as the linear expansion coefficient of the enclosure,
wherein a shift variation \u0394y per unit temperature of a distance y from a position at which the first cylindrical member and the second cylindrical member fit to each other to a position at which the lens is fixed to the first cylindrical member satisfies substantially Relation (1) below:
\u0394y\u2248\u0394x\u2212\u0394z\u2212\u0394fb\u2003\u2003(Relation 1)
where
\u0394x=\u03b1x,
\u0394y=\u03b2Y,
\u0394z=\u03b3z
\u0394fb: a back focus variation per unit temperature of the lens,
\u03b1: a linear expansion coefficient of the enclosure (unit:K),
\u03b2: a linear expansion coefficient of the first cylindrical member (unit:K),
\u03b3: a linear expansion coefficient of a stem provided to the semiconductor laser (unit:K),
x: a distance from a reference surface for attachment of the semiconductor laser to a position at which the first cylindrical member and the second cylindrical member fit to each other, and
z: a distance from a reference surface for attachment of the semiconductor laser to an emission point of the semiconductor laser.
2. The lens support mechanism according to claim 1, wherein the second cylindrical member and the enclosure are made of aluminum.
3. The lens support mechanism according to claim 1, wherein the second cylindrical member and the enclosure are made of zinc.
4. The lens support mechanism according to claim 1, wherein the second cylindrical member is made of zinc, and the enclosure is made of magnesium.
5. The lens support mechanism according to claim 1, wherein the second cylindrical member is made of zinc, and the enclosure is made of polyphenylene sulfide.
6. An optical head device comprising:
a lens support mechanism according to claim 1, and
an objective lens for converging, onto an information recording medium, the laser beam that has passed through the lens provided for the lens support mechanism.
7. An optical information processor comprising:
the optical head device according to claim 6,
a motor for rotating the information recording medium;
a servo mechanism for controlling the position of the objective lens provided to the optical head device, on the basis of a focus error signal and a tracking error signal obtained from the optical head device; and
an electric circuit for controlling the servo mechanism.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A mobile device retention system, comprising:
a mounting bracket
a retention unit for retaining a mobile device; and
a first mounting drawer having a plurality of acoustic apertures;
wherein said mounting bracket will retain said retention unit upright for viewing by a user and wherein said acoustic apertures enhance a quality of an audio produced by said mobile device.
2. The mobile device retention system according to claim 1, wherein said mounting bracket comprises:
a plurality of grooves;
a lower arm;
an upper arm; and
a gap between said lower and upper arms for attachment to a table.
3. The mobile device retention system according to claim 1, wherein said retention unit further comprises:
a second mounting drawer;
wherein said mounting drawers slide in and out of said retention unit.
4. The mobile device retention system according to claim 3, wherein said second mounting drawer further comprises an erasable surface.
5. The mobile device retention system according to claim 1, wherein the retention unit further comprises a top and back panel.
6. The mobile device retention system according to claim 5, wherein said top is hinged to said back panel.
7. The mobile device retention system according to claim 5, wherein said top is fixedly attached to said first drawer.