JPH01105377A - Tape traveling quantity correcting method - Google Patents

Abstract

PURPOSE:To drastically decrease an error and to obtain a correct tape traveling quantity by calculating a correction approximate to the error of the tape traveling quantity from the rotation cycles of the reels on a sending side and on a winding side, and adding it to the tape traveling quantity or subtracting it from the quantity. CONSTITUTION:The rotations of a reel 10 on the sending side and a reel 20 on the winding side are detected by rotation angle detectors 4 and 5, and a pulse signal from photo sensors 13 and 23 is outputted to a control part 2. The rotation cycles detected respectively by the detectors 4 and 5 are stored into a memory in the microcomputer of the device 2, and the traveling quantity of a tape 6 including the error is stored into the separate memory further a value in order to calculate the correction is stored into the separate memory. In addition, the device 2 compares the measurement completion times of the respective rotation cycles of the both reels 10 and 20, the value, which is obtained by subtracting 1/2 of the faster rotation cycle from the lower rotation cycle, is multiplied by a magnification for a normal tape scanning speed, this value is made into the correction, and the correction is added to the tape traveling quantity or subtracted from the quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tape running amount correction method in an apparatus for recording or reproducing signals using a tape-shaped recording medium such as a tape recorder or a VTR.

[Summary of the invention]

In the above-mentioned apparatus, when calculating and displaying the running distance of the tape from the rotation period of the sending reel and the take-up reel on which the recording medium tape is wound, The normal speed of the tape running speed at the time of measurement is calculated by comparing the end times of measurement of the rotation period of the take-up reel and subtracting 1/2 of the rotation period of the earlier one from the rotation period of the later one. The correction value is a value multiplied by a multiple of the tape running speed during recording or playback, and the tape running amount calculated from the rotation period of each reel is added to this correction value when the tape runs in the forward direction. When the tape runs in the opposite direction, this correction value is subtracted and corrected, thereby making it possible to display an accurate amount of tape travel.

[Conventional technology]

In a device that records or reproduces signals using a tape-shaped recording medium, a rotation angle detector detects the rotation of a sending reel and a take-up reel around which the recording medium tape is wound. The rotation period of each reel is determined by measuring the time required for each reel to rotate an integer number of times, the travel distance of the tape is calculated from each rotation period, and this is recorded or played back at a normal speed from the beginning of the tape. Those equipped with a tape running amount display device that displays the running time in hours are often used.

In such an apparatus, an example of a method of calculating the tape running amount from the rotation period of the sending reel and the take-up reel will be described.

The rotation period of the sending reel is Ts.

The radius of the tape wound on the same reel is Rs.

The rotation period of the take-up reel is Tt.

The radius of the tape wound on the same reel is Rt.

The radius of each reel's hub is r.

V is the tape running speed when measuring the rotation period.

The total length of the tape is Q, and the thickness of the tape is d.

When the tape travel distance is A, the areas Ss and St of the tape wound on the sending reel and the take-up reel, respectively, viewed from the axial direction are as follows.If A is calculated from this, then A=Q- 8t/(St+5s) = Q ・(Rt2-r2)/ (Rt" 10R52-
2r2)-■. Also, since it becomes, substituting these Rt and Rs into the 0 formula, it becomes. In this equation (2), (2πr/V)'' is constant, so if this is K, the equation (2) becomes as follows.

A=Q・(Tt”-K)/(Tt2+Ts”-2K)・
・・However, K=(2πr/V)” According to this formula, the rotation period Ts of each reel.

The tape running amount A was calculated and determined from Tt.

If you calculate the tape travel distance in this way, for example, even if a cassette is loaded where the tape is in the middle of winding,
Immediately after starting use, the amount of tape travel up to that point can be calculated and displayed.

[Problem that the invention seeks to solve]

However, even if we actually measure the rotation periods Ts and Tt of the sending reel and take-up reel and calculate the tape running distance by calculating, for example, the above-mentioned formula 0, the amount of time spent measuring the reel rotation period is Because there is a time limit, and because the measurement end points of the rotation period of both reels are usually different, the rotation period of the one that ended earlier is held until the measurement of the other reel ends. The actual period varies, which has the disadvantage of causing errors in the calculation results.

In particular, if the reel rotation period is determined by the average value of the time required for multiple rotations of the reel instead of the time required for one rotation, the amount of tape travel during measurement will increase, and the above error will also increase, so it is not practical. It was causing problems.

This problem can be solved by measuring the rotation period of both reels and
The same problem occurs when the tape running distance is determined by calculations other than formulas.

This invention was made in view of the above problems,
It is an object of the present invention to correct errors in the tape running amount determined as described above, so that a more accurate tape running amount can be displayed.

[Means for solving problems]

In order to achieve the above object, the present invention provides an apparatus for recording or reproducing signals using a tape-shaped recording medium, the apparatus comprising means for calculating and displaying the running distance of the tape as described above. , the measurement end time of the rotation period of the sending reel and the rotation period of the take-up reel is compared, and the time is calculated from the rotation period of the later one to the rotation period of the earlier one.
The correction value is the value obtained by subtracting /2 from the normal speed of the tape running speed at the time of measuring the rotation period, and a multiple of the tape running speed at the time of playback, and the tape calculated from the rotation period of each reel. The mileage of
This tape running amount correction method adds this correction value when the tape runs in the forward direction, and subtracts this correction value when the tape runs in the reverse direction.

[For production]

According to this invention, a correction value that approximates the error in the tape travel amount is easily calculated from the rotation period of the sending reel and the take-up reel, and the correction value is calculated from the rotation period of each reel according to the tape travel direction. By adding or subtracting from the calculated tape running amount, the error can be significantly reduced and an accurate tape running amount can be obtained.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram schematically showing only the portions related to the present invention of a tape recorder embodying the present invention.

1 is a measuring device that detects a rotation angle in order to measure the rotation period of each reel, which will be described later; 2 is a control device using a microcomputer; 3 is a control device that calculates the tape running distance calculated by the control device 2 from the beginning of the tape. This is a display device that digitally displays the running time during recording or playback.

The measuring device 1 includes a rotation angle detector 4 for detecting the rotation of the delivery reel 10 and a rotation angle detector 5 for detecting the rotation of the take-up reel 20.

The rotation angle detector 4 is located opposite to the outer circumferential surface of the reel stand on which the feed-out reel 10 on which the tape 6 as a recording medium is wound is mounted, or the rotating slit member 12 attached to the rotating shaft 11 of the reel stand. The rotating slit member 12 rotates in synchronization with the rotation of the sending reel 10, and the slit on its outer periphery intermittents the detection light of the photosensor 13. Thereby, the photosensor 13 sends a pulse signal to the control device 2 at every predetermined rotation angle (72° in this example) of the reel 10.

Similarly, the rotation angle detector 5 includes a reel stand on which a take-up reel 20 for winding the tape 6 is attached when the tape 6 travels in the forward direction, or a rotation slit member 22 attached to the rotation shaft 21 of the reel stand, and a rotation slit member 22 attached to the rotation shaft 21 thereof. The rotating slit member 22 is configured by a reflective photosensor 23 disposed opposite to the outer circumferential surface, and rotates in conjunction with the rotation of the take-up reel 20.
rotates and intermittents the detection light of the photosensor 23 through the slit on its outer periphery, thereby causing the photosensor 2
3 sends a pulse signal to the control device 2 every predetermined rotation angle (72'' in this example) of the reel 10.

In addition, instead of each reflection type photosensor 13.23, a transmission type photosensor is attached to the rotating slit member 12.22.
They may be arranged so as to sandwich the outer periphery of the.

The microcomputer of the arithmetic unit 2 executes the process shown in the flowchart of FIG. 2 to calculate and correct the tape travel amount.

The microcomputer includes a timer for measuring the rotation period of each of the following memories and each reel, and an end flag for comparing the end time of measurement of the rotation period of both reels.

(a) Memory that stores the rotation period Ts of the sending reel: MTs (b) Memory that stores the rotation period Tt of the take-up reel: MTt (c) Memory that stores the tape running distance A including error:
MA (d) Two MB of memory for storing the value B (B=Ts-Tt/2 or Tt-Ts/2) for calculating the correction value C. Hereinafter, the processing by the microcomputer of the control device 2 will be described in FIG. We will explain each step.

First, in step 1 it is determined whether the sending reel 10 has rotated once, and in step 2 it is determined whether the take-up reel 20 has rotated once.
When the reel rotates, the value stored in the memory MTs is updated according to the rotation period Ts of the sending reel 10 measured in step 3, and the end flag is set to 0°. Take-up reel 2
0 rotates once, the memories M and T are determined by the rotation period Tt of the take-up reel 20 measured in step 4.
Update the stored value of t and set the end flag to °1".

Then, in step 5, it is determined whether or not both wheels have rotated more than once, and if no, return to step 1 and repeat the above process, and if YES, proceed to step 6.
From Ts and Tt, perform the calculation according to the above formula 0, that is, A=Ω・(Tt2-K)/(Tt2+Ts2-2K), where K=(2πr/V)2, and calculate the tape running amount A including the error. The value stored in the memory MA is updated.

Next, in step 7, it is determined whether the end flag is 0°,
If it is 0, the measurement end time of the rotation period Ts of the sending reel 10 was later, so proceed to step 8 and
=Ts-Tt/2 is calculated, and the value stored in the memory MB is updated by the value of B. If it is 1°, the measurement end time of the rotation period Tt of the take-up reel 20 was later, so proceed to step 9 and calculate B = Ts - Tt/2, and use the value of B to store the memory MB. Update the stored value.

In either case, the process then proceeds to step 10, where B stored in the memory MB is multiplied by the speed number to obtain a correction value C. Here, the double speed number is the multiple of the tape running speed at the time of measuring the rotation period of the reel with respect to the tape running speed at the time of recording or reproducing the normal speed. For example, if the speed is 4 times, the value of B multiplied by 4 is corrected. Let the value be C.

Next, in step 11, it is determined whether the running force of the tape is in the forward direction (running direction from the sending reel side to the take-up reel side), and if it is in the forward direction, in step 12, A+C is calculated and corrected. If the tape is not in the forward direction (in other words, if it is in the reverse direction, that is, from the take-up reel side to the delivery reel side), then in step 13 A-C is set.
is calculated and the process is terminated with this as the corrected tape running amount.

This corrected tape running amount is displayed on the display device 3 as the tape running time (minutes and seconds) during normal speed recording or playback.

In this way, it is possible to almost correct errors caused by the running of the tape during the measurement of the rotation period of both reels, or the difference in the end point of measurement of the rotation period of the sending reel and the take-up reel. , it becomes possible to display accurate tape running amount.

In this embodiment, each of the rotation detectors 4 and 5 constituting the measuring device 1 detects the rotation angle of the reel based on a signal detected by a photo sensor of a slit portion of a rotation slit member attached to a reel stand or the like. However, a magnetic material with N and S poles alternately magnetized in the circumferential direction is added to a member that rotates together with the reel stand or reel 10°20, and the rotation is converted into a magnetoelectric converter such as a Hall element. It may be detected by an element.

Further, although an example has been described in which a microcomputer is used as the arithmetic device 2, a wired logic circuit may also be used to calculate the tape running amount, calculate the correction value, and perform the correction process.

Furthermore, the rotation period of each reel was measured by the time required for one rotation of the reel, and the n (n is a positive integer) of the reel.
The time required for rotation may be measured and the value of 1/n may be used as the rotation period of the reel.

Furthermore, the calculation of the tape running amount A including the error may be performed not by the formula 0 but by the following formula.

A=(K, α-Km)/(α+1) However, α=(T
t/Ts)2 to 1 =fl+r2/du K2 =r2/dυ Here, d is the thickness of the tape, and υ is the running speed of the tape during normal recording or reproduction.

Further, although the above-mentioned embodiment has been described as an example of displaying the tape running amount of a tape recorder, the present invention is not limited to this, and the present invention is not limited to this. - This invention can also be implemented in tape recorders (DAT), movie projectors, etc.

[Effects of the Invention] As described above, according to the present invention, the error in the tape running amount calculated from the rotation period of the sending reel and the rotation period of the take-up reel can be corrected by a relatively simple calculation. to obtain and display more accurate tape travel.

[Brief explanation of the drawing]

FIG. 1 is a block diagram schematically showing only the parts related to the present invention of a cheap recorder which is an embodiment of the present invention, and FIG. Flowchart of the correction process, 1...Measuring device 2...Control device 3...
・Display device 4, 5...Rotation angle detector 6・
... Tape (recording medium) 10 ... Sending side reel 20 ... Winding side reel 11.21 ... Rotating shaft 12.22 ... Rotating slit member 13.23 ... Reflective photo sensor

Claims (1)

[Scope of Claims] 1. A device for recording or reproducing signals using a tape-shaped recording medium, wherein the rotation of a sending reel and a take-up reel on which the tape serving as the recording medium is wound is controlled by rotation, respectively. Means for detecting with an angle detector, measuring the time required for each reel to rotate an integral number of times to obtain the rotation period of each reel, and calculating and displaying the running distance of the tape from each rotation period. In a device equipped with this, the measurement end time of the rotation period of the sending reel and the measurement end time of the rotation period of the take-up reel are compared, and the time is calculated from the later rotation period to 1/1/2 of the earlier rotation period. The correction value is the value obtained by subtracting 2 by a multiple of the normal speed of the tape running speed at the time of measuring the rotational cycle or the tape running speed at the time of playback, and the tape calculated from the rotational cycle of each reel. A tape running amount correction method characterized in that the running amount of the tape is corrected by adding the correction value when the tape runs in the forward direction and subtracting the correction value when the tape runs in the reverse direction.