DISC FILE SYSTEM

• US 3,555,286 A
• Filed: 08/22/1968
• Issued: 01/12/1971
• Est. Priority Date: 08/22/1968
• Status: Expired due to Term

• Current Assignee: Lawrence Cote
• Original Assignee: Lawrence Cote
• Inventors: Cote, Lawrence
• Application Number:
  US04/754,703
• Time in Patent Office: 873 Days
• US Class Current: 250/222.1
• CPC Class Codes: G11B 19/10 by sensing presence or absence of record in accessible stored position or on turntable

Abstract

Apparatus for use in a disc file system to sense the presence of a disc pack comprising a light sensor and lamp, both mounted on a bracket for movement onto opposite sides of the lower disc of the disc pack.

Claims

1. Apparatus for detecting the presence of a disc pack which includes a disc having timing slots at its periphery, comprising:

a bracket having a pair of arms for disposal on opposite side of said disc;

a pair of photocell means mounted on a first of said arms;

a pair of lamp means mounted on a second of said arms to shine a pair of light beams at said photocell means; and

means coupled to said photocell means for preventing the rotation of said disc pack unless at least one of said photocell means detects an interruption of a light beam.

2. The apparatus described in claim 1 including means for covering and uncovering said disc pack coupled to said bracket to move it toward and away from the position at which said disc is normally situated.

3. The apparatus described in claim 2 including a housing disposed at least partially about the area at which said disc pack is received, including a reception area for receiving said bracket when said means for covering and uncovering is in an uncovering position.

4. In a disc file system including a spindle for holding and rotating a disc pack in an area about said spindle, wherein the disc pack has a disc with at least one slot in a peripheral portion thereof, the improvement comprising:

light means for directing a pair of light beams simultaneously across a portion of said area about said spindle which is occupied by said peripheral portion of said disc when said disc pack is fully installed on said spindle;

a pair of photocell means positioned opposite said light means for detecting the interruption of said beams by said peripheral portion of a disc pack in said area; and

means coupled to said photocell means for preventing the rotation of said spindle means unless at least one of said light beams is interrupted.

5. The improvement described in claim 4 wherein:

said peripheral portion of said disc has at least a plurality of slots which are spaced by predetermined distances from each other; and

said light beams are spaced by a distance different than the spacing between any two of said slots.

6. The improvement is a disc file system described in claim 4 including:

a bracket having a first arm for holding said photocell means and a second arm for holding said light means in opposed relationship to said photocell means to shield said photocell means from ambient light, said arms spaced apart to fit on either side of a disc of said disc pack;

cover means for covering and uncovering said area about said spindle; and

means coupled to said cover means for moving said bracket toward and away from said area about said spindle in response to movement of said cover over and away from said area.