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:
Jan. 17, 1984
Filed:
Oct. 09, 1981
Applicant:
Inventors:
Ken Takahashi, Suita, JP;
Hiroshi Youda, Hirakata, JP;
Assignee:
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
29603 ; 360121 ;
Abstract
A method for making magnetic recording heads suitable for mass production with high accuracy. The track width tw or w of the head core is defined by a photolithographic etching method. First, larger grooves are formed by mechanical machining or electrolytic etching to form an outline of the pole piece parts, and then further smaller and shallower grooves are formed with very high accuracy by an etching process, such as electrolytic etching, sputter etching or ion etching at the edges of the first grooves. Thus, the track width of the head core is accurately determined by means of a photolithographic process.