Astigmatic lens for use in detecting a focussing error in an opt

Details Astigmatic lens for use in detecting a focussing error in an opt Astigmatic lens for use in detecting a focussing error in an opt

1994-11-04

1996-08-13

Epps, Georgia Y.

Optical: systems and elements

Lens

With multipart element

359571, G02B 308, G02B 518

Patent

active

055462359

ABSTRACT:
A cylindrical astigmatic lens is used conventionally in detecting focussing errors in an optical pickup system. The inventive astigmatic lens is comprised of an orthorhombic base, made of a refractive material, provided with two parallel surfaces and a centerplane perpendicular thereto, and two sets of M pentahedrons, made of the same refractive material, placed on one of the two parallel surfaces thereof in such a way that each set of M pentahedrons is symmetric with respect to the centerplane. Each of the pentahedrons consists of three rectangular surfaces and two right angled triangular side surfaces, each of the triangular side surfaces being defined by a height H.sub.m, a base R.sub.m and an inclination. Since the height is the same in all of the triangular side surfaces in the M pentahedrons, the dimension of each pentahedron in the inventive astigmatic lens is defined by R.sub.m, R.sub.m being expressed as ##EQU1## wherein f represents the focus length and .lambda. is the wavelength of the light source with the inventive astigmatic lens, it is possible to improve the alignment accuracy of the optical pickup system, since the inventive astigmatic lens being planar.

REFERENCES:
patent: 4023033 (1977-05-01), Bricot et al.
patent: 4824227 (1989-04-01), Goldenberg et al.
patent: 5002383 (1991-03-01), Sisler

Affiliated with

Also associated with

Rating

Astigmatic lens for use in detecting a focussing error in an opt does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Astigmatic lens for use in detecting a focussing error in an opt, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Astigmatic lens for use in detecting a focussing error in an opt will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1053264