JPH04332988A - Method and device for detecting thickness of tape - Google Patents

Abstract

PURPOSE:To detect the thickness of a tape without error regardless of the magnitude of the thickness and, at the same time, to accurately display the remaining time, etc., of the tape by not coping with a difference in the thickness through setting in hardware, but in software, and finding the thickness by calculation. CONSTITUTION:This method for detecting the thickness of tapes detects the thickness of a tape by calculation by using pulse period changing information obtained from the rotation of a take-up side tape reel 4 or feeding side tape reel 3, rotating speed of the reel, and a tape speed. The above-mentioned calculation for the take-up side is carried out by an equation, d= A.v0(TT-TT0)/2pi.nT, where the d, TT, TT0, nT, v0, and A respectively represent the thickness of the tape, pulse period of the take-up side tape reel, and initial pulse period of the take-up side tape reel, rotating speed of the take-up side tape reel from the initialization, tape speed, and number of poles of the tape reel.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention is applicable to tape recorders, DA
The present invention relates to a tape thickness detection method and device used in a device for detecting the running amount and remaining amount of tape in T-shirts, VTRs, etc.

0002

[Prior Art] In this type of device that detects the running amount and remaining amount of tape and displays the elapsed time and remaining amount time, conventionally, in order to detect the running amount of tape, the tape reel on the take-up side or the supply It is known to measure the period of a pulse train (hereinafter referred to as reel pulse) obtained in response to the rotation of a side tape reel, and to convert this measured period into the remaining amount of tape by calculation (for example, Japanese Patent Publication No. 58-197
No. 77, No. 57-143772, No. 63-21498
No. 8, No. 63-214989, No. 63-214990
(see publication).

0003

[Problem to be solved by the invention] However, conventional calculation methods do not take into account differences in the thickness of the tape used or the hub diameter of the reel of the equipment, and instead substitute fixed values for the tape thickness and hub diameter. and calculates it. Therefore, tapes and hubs with different numbers will output incorrect data, causing errors in the display of remaining time, etc. In order to deal with this, there is a method that deals with the difference in tape thickness by setting hardware. For example, in DAT, a detection hole is provided in the tape case for thin tape, the type of tape is detected, and the value used for calculation is changed based on the detection result. Furthermore, some VTRs are designed so that the user operates a changeover switch depending on the type of tape. However, the above methods become difficult to deal with in reality when there are many types of tapes with different thicknesses. Also, with the latter, if the user sets the toggle switch to the wrong position,
Wrong data is displayed.

The present invention has been made to solve the above-mentioned problems, and it deals with differences in tape thickness not by setting hardware, but by using software. To provide a tape thickness detection method and its method that can calculate the thickness of a tape by calculation, detect the tape thickness without error no matter what the tape thickness is, and can also accurately display remaining time, etc. The purpose is to provide equipment.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the invention of claim 1 uses pulse cycle change information obtained by rotation of a take-up tape reel, the number of rotations of the reel, and the tape speed. This is a tape thickness detection method that calculates the tape thickness by calculation. The invention of claim 2 performs the above calculation with the tape thickness being d and the pulse period of the take-up tape reel being T.
T, the initial pulse period of the tape reel is TT0, the number of rotations of the take-up tape reel from the initial setting is nT, the tape speed is v0, and the number of poles of the tape reel is A, then d=A・v0 ( The following formula is used: TT - TT0)/2π·nT. The third aspect of the invention is a tape thickness detection method in which the tape thickness is determined by calculation using information on changes in the rotation period of a tape reel on the supply side, the number of rotations of the reel, and the tape speed. In the invention of claim 4, the above calculation is performed by assuming that the tape thickness is d, the pulse period of the supply tape reel is TS, and the initial pulse period of the tape reel is TS0,
The number of revolutions of the supply tape reel from the initial setting is nS.
, when the tape speed is v0 and the number of poles of the tape reel is A, d=A・v0 (TS0-TS)/2π・nS
The following formula is used. The invention as claimed in claim 5 provides a rotation speed detection means for generating a pulse proportional to the rotation speed of the tape reel on the take-up side, and a predetermined calculation using a predetermined pulse period obtained from the rotation speed detection means. A tape thickness detecting device has a calculating means for calculating tape thickness, and the calculating means calculates the formula shown in claim 2. The invention as set forth in claim 6 provides a tape reel by performing a predetermined calculation using a rotation speed detection means that generates a pulse proportional to the rotation speed of the supply side tape reel and a predetermined pulse period obtained from the rotation speed detection means. and calculation means for calculating the thickness, the calculation means according to claim 4.
This is a tape thickness detecting device that calculates the equation shown below.

[0006]

[Operation] According to the above-mentioned method and apparatus, the pulse period change information obtained by the rotation of the tape reel on the take-up side or the supply side, the rotation speed of the same reel, and the tape speed are used to
Regardless of the thickness of the tape, the tape thickness can be determined by calculation.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the structure of a tape recorder in which the method and apparatus of the present invention are implemented. The microcomputer 1 takes in information on changes in the cycle of pulses (reel pulses) obtained by the rotation of the tape reel, calculates the tape thickness by a calculation described later, and performs a reel calculation based on the tape thickness calculated by this calculation. It has a function to calculate the remaining tape time, etc., and display it. A sensor 5 detects the rotation of the supply side reel 3 of the tape 2 as a means for obtaining pulses corresponding to the rotation of the tape reel.
and a sensor 6 that detects the rotation of the reel 4 on the take-up side (take-up side) of the tape 2. Each sensor 5, 6
The pulse signals from the microcomputer 1 are waveform-shaped via amplifiers 7 and 8, and are input to the microcomputer 1. Further, the rotation of the motor 9 that drives each reel 2, 4 is detected by the FG sensor 10, and this detection signal is inputted to the microcomputer 1 via the amplifier 11 as the tape speed. The display 12 displays the calculated remaining amount of tape, etc. The memory 13 is a storage means for storing various data and the like. A servo system for driving the tape reel is not shown.

Note that the memory 13 also stores hub radius data, and this data is also given to the microcomputer 1. In addition, the microcomputer 1 cumulatively stores the number of reel pulses, and calculates the current position based on changes, including increases and decreases, in the cumulative number of pulses even when the tape is fast forwarded or rewound. I try to do that.

FIG. 2 is a diagram schematically showing the supply side and take-up side of a tape reel, and the calculation formula for detecting the tape thickness by the microcomputer 1 will be explained below. In Figure 2, v0: Tape speed d: Tape thickness rh: Radius of the hub rT: Radius of the tape wound on the take-up side and the hub rS: Radius of the tape wound on the supply side and the hub rT0: Initial setting rT at time rS0: rS at initial setting TT: Reel pulse period on the take-up side TT0: Initial reel pulse period on the take-up side TS: Reel pulse period on the supply side TS0: Initial reel pulse period on the supply side A: Reel pulse period Number of poles nT: Number of rotations of the take-up reel from the time of initial setting (number of TT pulses counted A times) nS: Number of rotations of the supply side reel from the time of initial setting (number of TS pulses counted A number of times)
(number of times counted).

First, considering only the take-up reel, the following equation holds true. rT = rT0+d・nT

…■ Also, 2πrT = A・v
0 ・TT A・v
0 Therefore, rT =──────TT

…■
2π A・v0
rT0=──────TT0

…■ 2
From π ■, ■, ■ A・v0 A・v0 ─
────TT =──────TT0+d・nT
2π 2π Therefore, the tape thickness d is A・v0
d=──────(TT −TT0)
…■
It is determined by 2π・nT.

Similarly, in the case of the supply side reel,
rS = rS0-d・nS

...■, so the tape thickness d is A・v0
d=──────(TS0-TS)
…■
It is determined by 2π・nS.

Here, a reel calculation formula using the tape thickness d is shown below. Let the tape length from the tape start end be LT, the elapsed time be tT, and the area of the tape thickness wound on the take-up side be ST, then ST = π(rT 2 − rh 2 )
LT = π(rT2-rh2)/d
Since tT = LT /v0, tT =
π(rT 2 −rh 2 )/d・v0
…■
Substituting the previous formula ■ into this, the elapsed time tT becomes
π A2 ・v0
2 tT =────(──────TT 2
-rh2)
…■ d・v0 4π2
becomes. Similarly, if the remaining amount time is tS, then
π A2 ・v0 2
tS =────(──────TS 2
-rh2)
...■ d・v0 4π2. Conventionally, by substituting a fixed value for the tape thickness d in these formulas ■ and ■, the elapsed time tT and remaining amount time t
S was calculated and these were displayed. Therefore, if the thickness of the tape used is different from the substituted value, the display will include an error.

On the other hand, in this embodiment, by substituting the equations (2) and (2) for determining the tape thickness d into the above equations (2) and (2), the elapsed time tT from the beginning of the tape is calculated as follows:
2π2 ・nT A
2 ・v0 2 tT =──────────
──(──────TT 2 −rh 2 ) …(
10) A・v0 2 (TT −
TT0) 4π2 Tape remaining time tS is 2π2 ・nS
A2 ・v0 2 tS =───
────────(──────TS 2 -rh 2
) …(11) A・v0 2
(TS0-TS) 4π2. In addition, the tape recordable (playback) time tTAPE is t
TAPE=tT +tS

...(12) becomes.

[0014] Therefore, by determining the tape thickness d using the above formula (1) or (2), the data can be further expressed as
By substituting into equations (8), (9), and (12), it is possible to detect the elapsed time tT from the beginning of the tape, the remaining tape time tS, and the number of minutes of the tape being used. Information can be displayed on display 12. This information will be accurate no matter the thickness of the tape.

[0015]

As described above, according to the method and apparatus of the present invention, pulse cycle change information obtained by the rotation of the tape reel on the take-up side or the supply side, the rotation speed of the reel, and the tape speed are used. The tape thickness is calculated. The tape thickness determined by this calculation is accurate regardless of the type of tape. In this calculation, the tape thickness is d, the pulse period of the take-up tape reel is TT,
The initial pulse period of the tape reel is TT0, the number of revolutions of the take-up tape reel from the initial setting is nT, the tape speed is v0, the number of poles of the tape reel is A, the pulse period of the supply tape reel is TS, When the initial pulse period of the tape reel is TS0, and the number of rotations of the supply tape reel from the initial setting is nS, d=A・v0 (TT
−TT0)/2π・nT, or d=A・v0 (
This is done using the formula: TS0-TS)/2π・nS.

[0016] Then, the tape thickness d obtained by this calculation
It uses reel pulse calculations to accurately display remaining tape time, etc. Regarding this point, conventionally, in order to display the remaining tape time, etc., reel pulse calculations were performed by substituting a fixed value for the tape thickness. Errors were occurring in the display of quantity, time, etc. In contrast, in the present invention,
Since the tape thickness determined by the above calculation is accurate, it is possible to accurately display remaining amount time, etc. Therefore, it is also possible to properly perform running control such as slowing down the tape speed at the end of the tape to protect the tape. Further, the conventional hardware solution in which the user operates a changeover switch depending on the thickness of the tape to be used cannot cope with the increase in the number of types of tapes with different thicknesses. On the other hand, in the present invention, this problem is eliminated because it is handled by software.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a tape control device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a tape supply side and a take-up side for explaining calculation formulas according to the present invention.

[Explanation of symbols]

1 Microcomputer 3 Supply side tape reel 4 Take-up side tape reel 5,6 Sensor 12 Display 13 Memory

Claims (6)

[Claims] 1. A tape thickness detection method, characterized in that the tape thickness is determined by calculation using pulse cycle change information obtained from the rotation of a take-up tape reel, the number of rotations of the reel, and the tape speed. [Claim 2] The calculation according to claim 1 calculates the tape thickness by d
The pulse period of the take-up tape reel is TT, the initial pulse period of the tape reel is TT0, the number of revolutions of the take-up tape reel from the initial setting is nT, the tape speed is v0, and the number of poles of the tape reel is A tape thickness detection method characterized in that, when A, the following formula is used: d=A·v0 (TT −TT0)/2π·nT. 3. A tape thickness detection method, characterized in that the tape thickness is determined by calculation using information on changes in the rotation period of a tape reel on the supply side, the number of rotations of the reel, and the tape speed. [Claim 4] The calculation according to claim 3 calculates the tape thickness by d
Let TS be the pulse period of the tape reel on the supply side, TS0 be the initial pulse period of the tape reel, nS be the number of revolutions of the tape reel on the supply side from the initial setting, v0 be the tape speed, and A be the number of poles of the tape reel. A tape thickness detection method characterized in that the following formula is used: d=A·v0 (TS0−TS)/2π·nS. 5. The tape thickness is determined by performing a predetermined calculation using a rotation speed detection means that generates a pulse proportional to the rotation speed of the take-up tape reel and a predetermined pulse period obtained from the rotation speed detection means. , and the calculating means is configured such that the tape thickness is d, the pulse period of the tape reel on the winding side is TT, the initial pulse period of the tape reel is TT0, and the winding side from the time of initial setting is TT. Tape thickness detection characterized by performing the calculation d=A・v0 (TT − TT0)/2π・nT, where the rotation speed of the tape reel is nT, the tape speed is v0, and the number of poles of the tape reel is A. Device. 6. The tape thickness is determined by performing a predetermined calculation using a rotation speed detection means that generates a pulse proportional to the rotation speed of the supply tape reel and a predetermined pulse period obtained from the rotation speed detection means. and a calculation means for calculating, and the calculation means has a tape thickness d, a pulse period of the supply tape reel TS, an initial pulse period of the tape reel TS0, and a take-up tape reel from the time of initial setting. 1. A tape thickness detection device characterized by performing the calculation d=A·v0 (TS0−TS)/2π·nS, where nS is the rotational speed of the tape, v0 is the tape speed, and A is the number of poles of the tape reel.