JPH02103762A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To shorten the rewinding time by rewinding a tape usually at high speed and rewinding the tape at slow speed in the vicinity of the end of the tape or during the take-up of the tape, i.e. after that both revolving speeds of supply and take-up reels become equal to each other. CONSTITUTION:At the initial rewinding time, either of the supply and take-up reels 7 and 8 is rotated to take up the magnetic tape 3-6, where a revolving frequency of the take-up side reel 8 is denoted as ft, while a revolving frequency of the supply side reel 7 is fs, and when ft>fs, the reels 7 and 8 are rotated at high speed to take up the tape 3-6. Moreover since then, a revolving frequency of the take-up side reel 8 is denoted as Ft, while a revolving frequency of the supply side reel 7 is Fs, and when the time required to meet Ft<=Fs is longer than a prescribed time, the reels 7 and 8 are rotated again at low speed where Fs/Ft>=ft/fs is satisfied to take up the tape 3-6. When the time required to meet Ft<=Fs is shorter than the prescribed time, the slow speed mode is brought back where Ft<=Fs is satisfied. By this method, the rewinding time can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to reducing the time required for rewinding a tape in a magnetic recording/reproducing device at high speed.

BACKGROUND OF THE INVENTION In recent years, magnetic recording and reproducing devices (hereinafter abbreviated as VTR) have become popular and popular, and it is desired to shorten the time it takes to fast forward and rewind nine times when searching for a program on a recorded tape. .

In conventional rewinding, the reel on the winding side is rotated at a constant speed that allows the leader tape to stop without contacting the head on the tape running when the reel is stopped at the tape end. Ta.

Problems to be Solved by the Invention As stated above, if the conventional method of simply increasing the reel rotation speed and shortening the rewinding time is used, the head and leader tape will come into contact and the tape will become clogged. However, there was a problem in that there was a risk of serious damage such as breakage.

In view of the above problems, the present invention normally performs rewinding at high speed,
The present invention provides a magnetic recording/reproducing device capable of shortening the time by performing rewinding at a low speed near the end of the tape and during tape winding (where both reel rotational speeds are equal) and thereafter.

Means for Solving the Problems In order to solve the above problems, the magnetic recording device of the present invention rotates one of the supply and take-up reels at a low speed in the initial stage of rewinding to wind the magnetic tape; Take-up side reel rotation frequency f, supply side reel rotation frequency fB
When, f, > f.

If so, the reel is rotated at high speed to wind up the magnetic tape, and the subsequent winding side rotation frequency F0,
When the supply side reel rotation frequency is F8, if the time until Ft≦Fs is longer than the predetermined time T1, the reel is rotated at a low speed again when F8/F, ≧ft/f8 is satisfied, and the magnetic tape is If the time required for F, ≦FB is shorter than T1, the mode is returned to the low speed mode when the condition of F, ≦Fs is satisfied.

Function The present invention detects the rotational frequencies of the take-up reel and the supply reel with the above-described configuration, calculates the values, issues a high-speed rotation command to the reel drive control section near the end of the tape or during tape winding, A low speed command is issued near the end of the tape or during tape winding, thereby preventing damage to the head, etc. at the end of the tape.

Example The present invention will be explained below using examples.

Figure 1 is a mechanical diagram showing the tape running state of a home VTR.
Fig. 2 is a circuit diagram showing one embodiment of the present invention, and Fig. 3 is a circuit diagram showing an embodiment of the present invention.
This is a flow chart for explaining the operation of the microcomputer used in the figure.

Figure 1 shows the tape running path during fast forwarding and rewinding. 1 is the cylinder, 2 is the A/C head, 5 is the tape guide 3.4, 5.6 is the supply reel, 8 is the tape guide.
1 is a take-up series, 9 is a tape, 10.11 is a head attached to a cylinder, and 12 is a cassette.

As parameters, the take-up reel rotation frequency during low-speed rotation is ft, the supply reel rotation speed is f8, the take-up reel rotation frequency during high-speed rotation is T4, and the supply reel rotation speed is T6. Here, we will explain the fast-forward operation. When entering the fast-forward mode, the rotation is performed at low speed first, and the take-up reel rotation frequency f and the supply reel rotation frequency f8 are set at this time.
If f, > fs, it can be determined that the amount of tape on the supply reel is greater, and the V rotation speed is increased. At this time, calculate r-ft/fs.

Next, detect the take-up reel rotation frequency Ft and the supply reel rotation frequency F8 during high-speed rotation, calculate R=Fs/Ft, and compare it with the previously calculated r, so that r≦R, that is, f, /f6≦F s/F.

From the point where the condition is satisfied, the low speed rotation is also performed again 6,
.

Thud.

Here, if the reel diameters are the same, there is a point that satisfies the above conditions up to the end of the tape. but,
With a VHS-C adapter, the diameters of the two glue holes (V) are different, and the above conditions cannot be met and the tape ends at high speed, resulting in damage to the head, etc. may occur.

By the way, in the case of the VH8-C adapter, the amount of tape wound is smaller than that of the VH8 thin hub cassette, and the time it takes from the start of rewinding to the middle of the tape (where the rotation speed of both reels are equal) is Count and V
You can determine whether it is a standard H8 sumo kit or a VHS-C adapter. Therefore, if the time at which the two can be distinguished is T1, then
If the time required from the start of rewinding to the middle of the tape is longer than T1, the high speed mode is continued as it is, and if it is shorter than T1, the low speed mode is set from the middle of the tape. At this time, the tape is in low speed mode at the end, and no damage occurs.

Specific means for realizing the above discrimination and control method are described in the second section. This will be explained using FIG. 21 is a microcomputer, 22 is a take-up reel pulse detection circuit, 23 is a supply reel pulse detection circuit, 24 is a tape end detection circuit, 25 is an operation mode command section, 26 is a mechanism drive section, and 27 is a reel rotation command. be.

The entire operation of the circuit constructed as described above will be explained below with reference to FIG. 2 and FIG. 33.

In operation, the tape command unit 25 sends a rewind command to the microcomputer 2.
1, and the microcomputer 21 receives this and sets the mechanism drive section 26 to the rewind mode. 22 converts the rotation of the take-up reel into an electrical signal and inputs it to the microcomputer 21. Similarly, numeral 23 converts the rotation of the supply reel into an electrical signal and inputs it to the microcomputer 21 manually. Based on the processing results of the microcomputer 27 and 21, the mechanism drive unit 2 issues a high speed or low speed command.
6 to use human power.

Next, as shown in FIG. 3, when the microcomputer enters the rewind mode, it first changes to the low speed mode. The take-up reel rotation frequency f and the supply reel rotation frequency f8 are detected from human signals from the take-up reel pulse detection circuit 22 and the supply reel pulse detection circuit 23. f,
and fs, and if ft>f8, reel rotation command 2γ
to high speed mode and the reels to high speed rotation mode. Furthermore, the ratio of f and f6 at this time r = f t / f
Memorize s and at the same time measure the time it takes to rewind using the rewind time counter. Also, if f, < f8, then
Leave in low speed mode. Next, after entering the high-speed mode, the take-up reel pulse detection circuit 22 and the supply reel
The take-up reel rotation frequency F and the supply reel rotation frequency F8 are detected from the input signal from the Haruless detection circuit 23. If t is the value of the rewind time counter when F, ≦Fs, then if t≧T1, the high speed mode continues and the ratio of ft and fs is R=F, /F.
t is calculated, and when r≦R, that is, f6/f,≦F8/F, when compared with r calculated previously, the reel rotation command 27 is set to low speed mode. t(T
If it is I, it will immediately return to low speed mode. Then, after that,
A: The tape rotates at a low speed, and the end of the tape is reached.A tape end j1 signal is input from the tape end detection circuit 24 to the microcomputer 21, and the microcomputer 21 then sends stop operation information to the mechanism drive section 26, and rewinds. Even if the operation is stopped, the reel rotation speed remains low, so the operation can be stopped without causing any damage to the head or the like.

In addition, in a cassette with the same reel diameter, most of the intermediate sections are operated in high speed rotation mode, so the rewinding time can be significantly shortened.

As has been described in detail, according to the present invention, in a case where the reel diameters are the same, it is possible to rewind the tape at high speed without damaging the head or the like at the end of the tape, and the time required for rewinding the tape can be significantly shortened.

Also, with cassettes with different reel diameters such as VHS-C adapters, rewinding can be done without damaging the head or the like.

[Brief explanation of drawings]

Figure 1 is a top view showing the tape running state of a home VTR;
FIG. 2 is a circuit diagram showing an embodiment of the present invention, and FIG. 3 is a flowchart 1 for explaining the operation of the microcomputer used in FIG. 1...Cylinder, 2...A/C head, 3゜4.5.6...Tape guide, 7...
...Supply reel, 8...Take-up reel, 9.
...Tape, 1o. 11...Head attached to the cylinder, 1
2...Cassette, 21...Microcomputer, 22
...Take-up series pulse detection circuit, 23...
... Supply reel pulse detection circuit, 24 ... Tape end detection circuit, 25 ... Operation mode command section, 26 ... Mechanism drive section, 27 ......
Reel rotation command. Name of agent: Patent attorney Shigetaka Awano and one other person Figure Figure! !

Claims (1)

[Scope of Claims] A magnetic recording/reproducing device that rewinds the magnetic tape at high speed by loading a cassette containing a magnetic tape wound on a supply reel and a take-up reel, the rewinding being performed at a low speed at the beginning of rewinding. The magnetic tape is wound by rotating one of the supply and take-up reels, and the take-up reel rotation frequency f at that time is
_t, supply side reel rotation frequency f_s, f_t
> f_s, the reel is rotated at high speed to wind the magnetic tape, and further, when the winding side reel rotation frequency F_t and the supply side reel rotation frequency F_s are set, F_
If the time until t≦F_s is longer than the predetermined time T_1, the reel is rotated at low speed again to wind the magnetic tape when F_s/F_t≧f_t/f_s is satisfied until F_t≦F_s again. If the time is shorter than T_1, the magnetic recording and reproducing apparatus returns to the low speed mode when the condition F_t≦F_s is satisfied.