The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 10, 1994
Filed:
Nov. 13, 1992
Frank R Whitehead, Orangevale, CA (US);
Hyundai Electronics America, San Jose, CA (US);
Abstract
The invention provides an achromatic expansion prism for use in magneto-optical disk drive systems. The achromatic expansion prism comprises a first prism having a first dispersion value, an entrance surface through which a light beam enters the first prism and an outlet surface through which the light beam exits the first prism, and a constant deviation prism fixed to the outlet surface of the first prism and having a second dispersion value. The constant deviation prism reflects the light beam in a first direction to the optical disk and reflects the light beam reflected from the optical disk in a second direction to a detector. The angle between the first and the second directions is constant irrespective of the angle of incidence of the light beam on the first prism. Moreover, the first and second dispersion values are selected such that the first and second directions are independent of wavelength of the light beam. The achromatic expansion prism thereby simplifies alignment of the prism for proper direction of the light beam toward the disk and detector, and has fewer components and compact size.