Method and apparatus for determining addresses in time along a recording tape

• US 5,724,203 A
• Filed: 10/25/1996
• Issued: 03/03/1998
• Est. Priority Date: 08/19/1991
• Status: Expired due to Fees

• Current Assignee: Index Systems Incorporated (Adeia Inc.)
• Original Assignee: Index Systems Incorporated (Adeia Inc.)
• Inventors: Kwoh, Daniel S., Ng, Yee Kong
• Primary Examiner(s): Sniezek, Andrew L.
• Application Number:
  US08/736,789
• Time in Patent Office: 494 Days
• Field of Search: 360/72.3, 360/74.2, 360/72.1, 360/71, 242/334.5
• US Class Current: 360/72.3
• CPC Class Codes: G11B 15/023 remotely controlled
• CPC Class Codes: G11B 15/026 by using processor, e.g. microcomputer
• CPC Class Codes: G11B 15/07 on containers
• CPC Class Codes: G11B 15/087 by sensing recorded signals
• CPC Class Codes: G11B 15/1816 Programmed access in sequence to indexed parts of operating tapes cooperating with rotating heads see provisional also G11B15/005
• CPC Class Codes: G11B 2220/41 Flat as opposed to hierarchical combination, e.g. library of tapes or discs, CD changer, or groups of record carriers that together store one title
• CPC Class Codes: G11B 2220/65 wherein solid state memory is used for storing indexing information or metadata
• CPC Class Codes: G11B 2220/90 Tape-like record carriers
• CPC Class Codes: G11B 2220/91 Helical scan format, wherein tracks are slightly tilted with respect to tape direction, e.g. VHS, DAT, DVC, AIT or exabyte
• CPC Class Codes: G11B 23/08714 Auxiliary features sensing such features G11B15/06
• CPC Class Codes: G11B 23/30 with provision for auxiliary signals
• CPC Class Codes: G11B 23/36 Signals on record carriers or on containers and recorded by the same method as the main recording
• CPC Class Codes: G11B 27/002 Programmed access in sequence to a plurality of record carriers or indexed parts, e.g. tracks, thereof, e.g. for editing; transfer of record carriers from magazine G11B15/68, G11B17/10; G11B17/22
• CPC Class Codes: G11B 27/024 on tapes G11B27/028, G11B27/029 take precedence
• CPC Class Codes: G11B 27/029 Insert-editing
• CPC Class Codes: G11B 27/107 of operating tapes
• CPC Class Codes: G11B 27/11 by using information not detectable on the record carrier
• CPC Class Codes: G11B 27/13 the information being derived from movement of the record carrier, e.g. using tachometer
• CPC Class Codes: G11B 27/3054 Vertical Interval Time code [VITC]
• CPC Class Codes: G11B 27/309 Table of contents
• CPC Class Codes: G11B 27/324 : Duty cycle modulation of control pulses, e.g. VHS-CTL-coding systems, RAPID-time code, VASS- or VISS-cue signals
• CPC Class Codes: G11B 27/328 : on a tape [TTOC]
• CPC Class Codes: G11B 27/34 : Indicating arrangements indicating means incorporated in magazine or cassette G11B23/046 and G11B23/0875; indicating measured values in general G01D
• CPC Class Codes: G11B 31/00 : Arrangements for the associated working of recording or reproducing apparatus with related apparatus with cameras or projectors G03B31/00 ; recording/reproducing of music for electrophonic musical instruments G10H1/0033; automatic arrangements for answering calls or for recording messages for absent subscribers H04M1/64; telephonic communication systems adapted for combination with dictation recording and playback systems H04M11/10; connection of TV recorder with other related apparatus, e.g. TV camera or receiver, in which the TV signal is significantly involved H04N, e.g. H04N23/00, H04N5/765; combination of radio or TV with other apparatus, e.g. with vehicles H05K11/00
• CPC Class Codes: G11B 33/10 : Indicating arrangements; Warning arrangements G11B15/04, G11B19/04, G11B27/34, G11B27/36 take precedence
• CPC Class Codes: G11B 5/0086 : using cyclically driven heads providing segmented tracks
• CPC Class Codes: H04N 5/45 : Picture in picture , e.g. displaying simultaneously another television channel in a region of the screen
• CPC Class Codes: H04N 5/765 : Interface circuits between an apparatus for recording and another apparatus
• CPC Class Codes: H04N 5/775 : between a recording apparatus and a television receiver
• CPC Class Codes: H04N 5/7755 : the recorder being connected to, or coupled with, the antenna of the television receiver
• CPC Class Codes: H04N 5/782 : on tape
• CPC Class Codes: H04N 5/78263 : for recording on tracks inclined relative to the direction of movement of the tape
• CPC Class Codes: H04N 5/9206 : the additional signal being a character code signal
• CPC Class Codes: H04N 7/0887 : for the transmission of programme or channel identifying signals

Abstract

Apparatus and methods are provided for measuring an address in time between the beginning of the tape on the reel and the current location along a recording tape wound around a hub of a reel. A method for measuring an address in time between the beginning of the tape on the reel and the current location along a recording tape wound around a hub of a reel comprises the steps of measuring a single rotational period of the reel near a first location along the recording tape being represented as Tp, storing a single rotational period of the reel when the radius of the tape on the reel is approximately the same as the radius of the reel hub being represented as To, storing a differential period between one rotational period of the reel and the next rotational period of the reel as the recording tape is wound around or unwound from the reel being represented as dT, and deriving from Tp, To and dT, an address in time from the beginning of the tape to the first location on the tape by calculating a value Tc corresponding to Tc=(Tp02-To02)/(2 * dT). A method is also provided for measuring a start address for a program recorded on a recording tape wound around a hub of a reel as the program is recorded by measuring a single rotational period of the supply reel near a start of the recording of the program.

Claims

1. An apparatus for measuring an address in time between a beginning of a tape on a reel and a current location along the tape wound around a hub of the reel comprising:

means for measuring a single rotational period of the reel near a first location along the tape being represented as Tp;

means for storing a single rotational period of the reel when the radius of the tape on the reel is approximately the same as the radius of the reel hub being represented as To;

means for deriving an average differential period between one rotational period of the reel and the next rotational period of the reel as the tape is wound around or unwound from the reel being represented as dT; and

means for deriving from Tp, To and dT, an address in time from the beginning of the tape to the first location on the tape.

2. An apparatus for measuring a start address for a program recorded on a recording tape wound around a hub of a take-up reel as the program is recorded comprising:

means for measuring a single rotational period of the take-up reel near a start of the recording of the program being represented as Ts;

means for counting the number of revolutions of the take-up reel between the start and an end of the recording, the number of revolutions being represented as N;

means for measuring a single rotational period of the take-up reel near the end of the recording of the program being represented as Te;

means for calculating an average differential period between one rotational period of the take-up reel and the next rotational period of the take-up reel as the recording tape is wound around or unwound from the take-up reel being represented as dT by using Ts, N and Te;

means for storing a single rotational period of the reel when the radius of the tape on the reel is approximately the same us the radius of the reel hub being represented as To; and

means for deriving from Ts, N, To, and To, the start address being represented by Tsa as the time between the beginning of the tape on the take-up reel and the start of recording of the program recorded along the recording tape.

3. The apparatus of claim 2, additionally comprising means for deriving from Ts, N, Te, and To, the end address of the program being represented by Tea as the time between the beginning of the tape on the take-up reel and the end of recording of the program recorded along the recording tape.

4. The apparatus of claim 3, additionally comprising means for subtracting Tsa from Tea to determine the length of the program.

5. The apparatus of claim 3, in which the means for deriving from Ts, N, Te, and To, the end address of the program being represented by Tea as the time between the beginning of the tape on the take-up reel and the end of recording of the program recorded along the recording tape additionally comprises processor means for obtaining a value Tea corresponding to

6. The apparatus of claim 2, in which the means for measuring a single rotational period of the take-up reel near a start of the recording of the program being represented as Ts additionally comprises:

means for generating pulses as the take-up reel rotates;

a rotational period counter means coupled to the means for generating pulses for measuring time for a rotation of the take-up reel; and

a clock coupled to the rotational period counter.

7. The apparatus of claim 6, in which the means for counting the number of revolutions of the take-up reel between the start and an end of the recording, the number of revolutions being represented as N additionally comprises a revolution counter means coupled to the means for generating pulses for counting the revolutions of the take-up reel.

8. The apparatus of claim 2, in which the means for measuring a single rotational period of the take-up reel near a start of the recording of the program being represented as Ts comprises:

a plurality of reflective lines on the take-up reel;

optical detector means for sensing the passing of the reflective lines as the take-up reel rotates;

a rotational period counter means coupled to the optical detector means for measuring a time for a rotation of the take-up reel; and

a clock coupled to the rotational period counter.

9. The apparatus of claim 2, in which the means for calculating an average differential period between one rotational period of the take-up reel and the next rotational period of the take-up reel as the recording tape is wound around or unwound from the take-up reel being represented as dT by using Ts, N and Te additionally comprises process means for obtaining a value dT corresponding to

10. The apparatus of claim 2, in which the means for deriving from Ts, N, and To, the start address being represented by Tsa as the time between the beginning of the tape on the take-up reel and the start of recording of the program recorded along the recording tape additionally comprises processor means for obtaining a value Tsa corresponding to

11. A method for measuring a length of a tape wound between a supply reel having a hub and a take-up reel having a hub comprising the steps of:

winding the entire length of tape onto either the supply reel or the take-up reel;

measuring a single rotational period being represented as Tp of the reel upon which the tape is wound;

storing a single rotational period of the reel when the radius of the tape on the reel is approximately the same as the radius of the reel hub being represented as To;

deriving an average differential period between one rotational period of the supply or take up reel and the next rotational period of the supply or take up reel as the tape is wound around the supply or take up reel being represented as dT; and

deriving from Tp, To and dT an address in time from the beginning of the tape to the end of the tape.

12. The method of claim 11 wherein the step of deriving from Tp, To and dT an address in time from the beginning of the tape to the end of the tape comprises the step of calculating a value T1 corresponding to