Device for detecting tape end of magnetic recording apparatus

• US 4,343,024 A
• Filed: 05/08/1980
• Issued: 08/03/1982
• Est. Priority Date: 05/08/1980
• Status: Expired due to Term

• Current Assignee: Efuti Giken Company Limited, Funai Electric Co., Ltd. (Funai Electric Holdings Company Limited)
• Original Assignee: Efuti Giken Company Limited, Funai Electric Co., Ltd. (Funai Electric Holdings Company Limited)
• Inventors: Kawai, Tsutomu
• Primary Examiner(s): Eddleman, Alfred H.
• Application Number:
  US06/147,832
• Time in Patent Office: 817 Days
• Field of Search: 360/74.6, 360/74.5, 360/132-133, 242/188
• US Class Current: 360/74.6
• CPC Class Codes: G11B 15/08 by photoelectric sensing G11B15/07 takes precedence
• CPC Class Codes: G11B 15/675 Guiding containers , e.g. loading, ejecting cassettes
• CPC Class Codes: G11B 23/087 using two different reels or cores

Abstract

A video tape cassette of the type wherein a supply reel and a take-up reel are contained therein holds a magnetic video tape having transparent sections of tape at each end connected to a respectively one of the reels. A light-receiving element, or sensor, such as a phototransistor is incorporated into one of the positioning poles which enters into a cooperating opening in the cassette when it is put into position, and a light-emitting element, such as a light emitting diode is provided on the base outside of the cassette so that the end of the tape can be detected by the cooperative action of these two elements to automatically stop the running of the tape. Since the light-receiving element can be incorporated into the existing positioning pole, no additional space is required and the device can be incorporated into already existing video tape recorders. Obviously, the same results can be achieved if the phototransistor and light-emitting diode are interchanged.

Claims

1. In a device for detecting a transparent portion of a normally opaque magnetic tape carried on a pair of reels arranged side by side within a cassette having openings in the bottom for positioning the cassette and an opening along one side to allow removal of an intermediate length of tape during operation and end openings in horizontal alignment with the plane of the tape, said cassette being initially supported on a tiltable receiving plate which is lowered downwardly to be supported on a fixed base plate when the cassette is in use, both of said plates being provided with openings to accomodate cassette reel driving shafts and cassette positioning poles, the combination comprising:

a unitary assembly comprising a generally U-shaped member having embedded in the upper portions of the respective upstanding legs thereof a light source, and light sensor to be responsive to the direct radiation from said light source;

the intermediate portion of said member being an elongated flat section to lie against the under side of said base plate;

one of said upstanding legs having an upwardly and inwardly tapering circular cross-section defining a positioning pole for a cassette to project upwardly through aligned openings in said plates;

the other of said upstanding legs to be disposed closely adjacent the exterior of one end of a cassette at the location of an end opening;

said light source being positioned when said flat section lies against the under side of the base plate to project radiation in a path to pass through the end opening of the cassette to be directly received by the light sensor after being intercepted by the tape.

2. Device as defined in claim 1, wherein said light source is embedded in said one of the upstanding legs defining a positioning pole.

3. Device as defined in either one of claims 1 or 2, wherein the other of said upstanding legs comprises a flat strip lying in a plane parallel with the end surface of a cassette.

4. Device as defined in claim 3, wherein said light sensor is embedded in said flat strip.