Pickup stylus having fused diamond and ceramic bodies with conductive surfaces for capacitance disk records

• US 4,542,493 A
• Filed: 12/04/1981
• Issued: 09/17/1985
• Est. Priority Date: 12/05/1980
• Status: Expired due to Fees

• Current Assignee: Victor Company of Japan Limited (JVC Kenwood Corporation)
• Original Assignee: Victor Company of Japan Limited (JVC Kenwood Corporation)
• Inventors: Takehara, Hideaki
• Primary Examiner(s): PSITOS, ARISTOTELIS
• Application Number:
  US06/327,672
• Time in Patent Office: 1,383 Days
• Field of Search: 369/126, 369/173
• US Class Current: 369/126
• CPC Class Codes: G11B 9/075 using mechanical contact with record carrier, e.g. by stylus

Abstract

An oxidation resistant soldering compound is deposited in a bore formed on an end of a ceramic shank. A diamond grain is placed in the bore of the shank and heated at an elevated temperature in a vacuum to solder the diamond with the ceramic shank. The soldered diamond and ceramic body are lapped into the shape of a stylus. The stylus is subsequently placed in an environment containing a small amount of oxygen and heated at a temperature lower than the solidus temperature of the soldering compound to convert the surface area of the diamond into a conductive layer of carbon which is lapped into an elongated form to serve as a stylus electrode.

Claims

1. A pickup stylus for capacitance disk records comprising:

a ceramic body having a bore on one end thereof;

a diamond body having a surface and having a conductive layer of carbon as an integral part of said surface, the diamond body partially extending into said bore; and

an oxidation resistant soldering material for soldering said bodies together.

2. A pickup stylus as claimed in claim 1, wherein said ceramic body comprises a porous ceramic material.

3. A pickup stylus as claimed in claim 1, wherein said soldering material comprises a compound of gold or a platinum compound of gold and palladium.

4. A pickup stylus as claimed in claim 3, wherein said compound has a weight percent of 65 percent to 85 percent of gold and a weight percent of 35 percent to 15 percent of platinum or a weight percent of 90 percent to 94 percent of gold and a weight percent of 10 percent to 6 percent of palladium.

5. A pickup stylus as claimed in claim 4, wherein said compound has a gold-to-platinum ratio of 75:

25 or a gold-to-palladium ratio of 92;

8.

6. A pickup stylus as claimed in claim 3, wherein said compound further comprises a small amount of titanium.