JPS60234282A - Program searching mechanism of recording medium - Google Patents

Abstract

PURPOSE:To facilitate approximately an easy program searching action by setting previously the program searching positions in fast forward and rewind modes, and stopping automatically the drive of a magnetic tape at those positions. CONSTITUTION:The revolutions of both supply and take-up reels 12 and 13 are converted into pulse signals by sensors 16B and 16A. While counters 21 and 22 counts the rotational frequencies of both reels. Based on the output difference of both counters, a position detector 23 detects roughly the position of a magnetic tape which is under shift. A comparator 24 decides the coincidence between the take-up position of the tape and the program searching position set by a slide variable resistor 1. When the coincidence is decided, the drive of the tape is stopped via a loading motor 32. In such a way, an easy rough program searching action is facilitated.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a mechanism for locating the beginning of a recording medium in a magnetic recording/reproducing device, etc., and particularly for fast-forwarding or rewinding a magnetic tape (recording medium) at high speed. This invention relates to a so-called magnetic tape cue mechanism that stops the magnetic tape at almost any position during execution.

[Background of the invention]

In conventional magnetic recording and reproducing apparatuses, there are the following so-called cue mechanisms for selecting an arbitrary position from a recorded portion of information recorded on a magnetic tape.

First, when a member that comes into contact with the magnetic tape while the magnetic tape is running or a head installed in the member starts recording information on the tape, a recording start signal is sent, or an arbitrary screen is sent during recording. There is a mechanism for writing position detection signals on the magnetic tape in preparation for reproduction, and by reading these signals during reproduction to locate the beginning and stop fast forwarding and rewinding of the magnetic tape.

This mechanism is insufficient because it only stops at the recording start position when cuing up using a recording start signal, or if you want to cue up at an arbitrary position, you can use it later. It is necessary to operate a necessary switch in order to write the position detection signal in advance during recording in the part where the output is desired, and there is a drawback in that it requires consideration and effort. Another disadvantage is that it is necessary to add a magnetic head for writing and detection purposes, resulting in high costs.

In some cases, the magnetic tape is guided to a predetermined position during detection in a so-called half-loading state without increasing the number of heads, and a magnetic head that comes into contact with the magnetic tape as it travels is used, but this is a mechanism for positioning a predetermined transport member. is required separately. Furthermore, currently, as mentioned above, writing a position detection signal on a magnetic tape means that noise is introduced into the main signal, and for example, in a VTR, that noise becomes audio noise. There are drawbacks such as appearing.

Second, in order to search for the scene you want to watch at high speed while viewing the playback image, there is also a method of cuing up the tape by loading the magnetic tape and sending it at several times to several times the normal playback speed. However, if a tape has been recorded for a long time, for example, a tape recorded for 8 hours, it will take about 30 minutes to an hour to search for the beginning, and during this time it will take about 30 minutes to an hour to find the beginning of the tape. Because of this, you can't take your hands off it, which results in a lot of wasted time.

You can shorten the time you spend looking at this screen by fast-forwarding or rewinding to roughly the location you want to see, but even if you know in advance how far to advance the magnetic tape, you can It is necessary to monitor the speed of fast forwarding and rewinding to see if it is being sent.

If you cannot directly see the feeding status of the magnetic tape, such as with a front-load type magnetic recording/playback device, you can eject the magnetic tape cassette after it has been fed a certain amount, and then check how much time is left. The disadvantage is that the cassette must be inserted into the recording/playback device again after estimating whether it is needed, which is troublesome and time-consuming.

In addition, if the search speed is increased in an attempt to shorten the time required, for example, on a VTR, the area of noise on the TV monitor image will become wider, and electrical image processing will be required to check the screen. In the case of a tape recorder, there is a disadvantage that it becomes impossible to distinguish the audio, making it difficult to find the beginning.

A third method is to use a tape counter attached to the magnetic recording/reproducing device. However, there is no unified standard for the scale of a tape counter, and since the scale is not proportional to the tape feed length, for example, in VTRs, it depends on the type of tape, such as whether the magnetic tape is a 60-minute tape or a 120-minute tape. However, the disadvantage is that the cue cannot be found unless the relationship between the tape feed length and the scale is determined using a complicated conversion formula, or by guessing based on the operator's experience, making the method complicated.

[Purpose of the invention]

The present invention has been made in order to solve the above-mentioned drawbacks of the prior art, and therefore, an object of the present invention is to solve the problem of the need to record a position detection signal for cueing on a recording medium in advance. In addition, it does not require unnecessary effort such as monitoring the recording medium undergoing feeding operation during cueing, and it is extremely simple and time-saving, rather than using complicated methods such as when using a tape counter. It is an object of the present invention to provide a recording medium cueing mechanism that can easily perform general cueing.

[Summary of the invention]

If you know approximately where the part you want to cue is based on the diameter of the magnetic tape, it is convenient to first fast-forward or rewind to that point. However, as mentioned above, with front-load type magnetic recording and reproducing devices, it is not possible to monitor the winding diameter because it is not possible to see the feeding status of the magnetic tape, and even with the type that can be seen, it may end up going too far beyond the planned radial position. The tape radius must be watched for a specified period of time to ensure that no damage occurs.

It takes about 5 minutes to fast-forward and rewind a magnetic tape on a VTR, and it is physically painful to maintain consciousness during that time to monitor the tape radius.

Therefore, in the present invention, a mechanism is adopted in which the end of fast forwarding/rewinding, that is, the approximate cue position, is set in advance, and the magnetic tape is automatically stopped at that position.

With a mechanism that automatically stops at a predetermined position, there is no need to pay attention to the tape running until it stops, and the waiting time can be used for other tasks, making it ideal for front-load VTRs. However, there is no need to go to the trouble of providing a window through which the magnetic tape cassette hub can be monitored.

In this way, the present invention allows the feeding operation of the recording medium that is unwound from the first reel and wound onto the second reel to the position where the medium has been wound by an arbitrary length (the beginning position). a recording medium cueing mechanism for stopping the recording medium at a position, the first and second rotational speed detecting means detecting the rotational speeds of the first and second reels, respectively; a means for detecting the winding position of the tape, a means for presetting a cue position, a detection output from the detection means and a setting output from the setting means, and when the two match, a feeding operation of the recording medium is performed. It is characterized by comprising means for stopping.

[Embodiments of the invention]

The present invention will now be described in detail with reference to the drawings.

Figure 1 is a perspective view showing the appearance of a VTR embodying the present invention. In the figure, 1 is a slide volume, 2 is a cue button switch, 3 is a fast forward button, and 4 is a rewind button.

FIG. 2 is an enlarged view showing details of the main part (near the slide volume 1) in FIG. 1.

Please refer to FIGS. 1 and 2. In the VTR embodying the present invention, a slide volume 1 is provided on the exterior surface for roughly setting the cue position. That is, the volume 1
The settings are made by sliding to any position on a series of scales from the beginning of the volume, through the middle of the volume, to the end of the volume. Assume that the setting is now in the middle of the winding (meaning the middle of the winding diameter).

Next, press the cue button switch 2, and press the fast forward button 3 or rewind button 4 in the direction you want to move.

As a result, the magnetic tape in the VTR is fast-forwarded, and the beginning is located at the middle of the tape diameter.

FIG. 3 is a plan view of a VTR in fast-forward mode. In the same figure, 7 is a chassis, 10 is a magnetic tape cassette, 11 is a magnetic tape, 12 is a feeding reel, 13 is a take-up reel, and 14 is a motor pulley. , 15 is idler,
15A and 16B are reel rotational speed (rotation per unit time) detection sensors, respectively.

In the magnetic tape cassette 1o, which is installed at a predetermined position using electric or manual means, the magnetic tape 11 is driven to run by a feeding reel 12 and a take-up reel 13.

In fast-forward mode, the reel drive motor (see figure -9-
- to the idler 15) from the motor pulley 14 to the idler 15.
The winding reel 13 winds the magnetic tape 11 at high speed in the forward direction of the arrow. On the lower chassis 7 surface of the take-up reel 13 and the feed-out reel 12, a sensor 3i3 detects the number of rotations (rotation speed) per unit time of both reels;
16A and 16B are attached respectively.

The rotational speed of the take-up reel 13 detected by the sensor 16A and the feed-out reel 1 detected by the sensor 16B
By comparing the two rotational speeds, the winding position of the tape 11 can be determined. At the beginning of winding the tape 11, the rotational speed of the spring reel 13 is fast and the rotational speed of the feeding reel 12 is slow. Sowaga. Ka, □yo, wa, yai, yo'l-/L
-13011ffi iWhen the rolling speed becomes slow and that of the feeding reel 12 becomes fast, and the middle of the entire length of the tape has been wound, the winding diameter of the tape on the reel 13 and that on the reel 12 are equal, so that both times
(The rolling speed becomes equal. And at the end of winding, 1
0- The rotational speed of reel 13 is much slower than that of reel 12.

In short, the winding position of the tape 11 can be known by comparing the detection outputs of the rotational speed detection sensors 16A and 16B, and the present invention uses this fact to perform cueing.

FIG. 4 is a block diagram showing the configuration of an embodiment of the present invention. In this figure, the same elements as in FIGS. 1 to 3 are given the same reference numerals.

In addition, a counter 21 counts the detection output of the rotation speed detection sensor 16B, a counter 22 counts the detection output of the same <16A, and a counter 23 detects the tape winding position by comparing the count outputs of both counters. A position detector 24 is a comparator that compares the detection output (tape winding position) input via the cue button switch 2 with the cue position setting output from the slide volume 1.

A loading motor 32 performs an operation to stop the tape feeding operation when a matching output is inputted from the comparator 24.

IJ-Rule 12 for zero refilling to explain the operation in more detail
And 130 rotations of the winding reel are sensor i6B, x6
A converts it into a pulse signal, and counters 21 and 22 count the number of rotations as the pulse signal.

Difference in count output between counters 21 and 22 (difference in rotation speed)
Therefore, the position detector 23 can detect the type of magnetic tape cassette 10 (for example, T-60 or T-120) and the approximate position of the magnetic tape 11 during transfer.

Prior to execution of the fast forward/rewind operation, a comparator 24 checks whether or not the cue position (stop position) set by the slide volume 1 matches the winding position of the magnetic tape 11.
When they match, that is, when the magnetic tape 11 reaches the set cue position, the loading motor 32 for operating the tape loading mechanism (not shown) is rotated, and all mechanisms in the VTR are fast-forwarded.・Move from the rewind position to the stop position.

When the magnetic tape 11 enters the stop position, the reel driving motor stops rotating, a main brake (not shown) is applied to the feeding reel 12 and the take-up IJ reel 13, and the feeding of the magnetic tape 11 is stopped.

Next, the detector 23 for detecting the winding position of the magnetic tape during fast forwarding and rewinding will be specifically explained. FIG. 5 is a perspective view of the feeding reel 12 and the take-up reel 13 seen from below. A reflective plate 20 in which surfaces that reflect light and surfaces that do not reflect light are arranged alternately is attached to the bottom surface of both reels, and the sensor 16B mounted on the surface of the chassis 7 described above is attached to the bottom surface of both reels.
, 16A are arranged to face the reflecting plate 20 with a predetermined distance therebetween.

That is, as the reels 12 and 13 rotate, the reflector 20
When it rotates, light from a light source (not shown) is interrupted by the reflection plate 20 and enters the sensors 6B and 16A, so if this is detected and counted by the counter, the reel 12.13
It is possible to count the number of revolutions.

Since the method for detecting rotational speed and rotational speed using such an optical sensor is well known, further explanation will be omitted here.

Furthermore, by comparing the rotation speeds of both the feed reel 12 and the take-up reel 130, it is possible to determine the type of magnetic tape cassette 10, for example, T-60 or T-120, and to determine the type of magnetic tape 11 based on the difference in winding diameter. The approximate position can be detected. This method is used as a function to display the remaining amount of the magnetic tape 11 during playback and recording, and is not new in itself, so a detailed explanation will be omitted.

In the above embodiment, the rotation of the reel has been explained using an example in which the rotation of the reel is detected by an optical sensor, but other known examples, an example in which a permanent magnet or a magnetized member is attached to the reel and detected by a magnetic sensor, or A row or the like may be used in which the reel hub portion is irradiated with light to directly measure the winding diameter of the tape.

Furthermore, although the present embodiment has been explained using a VTR as an example, the present invention can be applied to all magnetic recording/reproducing apparatuses that use a magnetic tape whose ends are fixed to two reels.

〔Effect of the invention〕

According to the present invention, when searching for the head of a desired part among the contents recorded on a magnetic tape, if the approximate position of the part recorded on the magnetic tape is known, the slide volume can be set in advance. It is possible to provide a magnetic recording and reproducing device in which the tape can be fast-forwarded and rewinded simply by holding the tape in place, and the tape stops at roughly the desired position (near the beginning). This eliminates the need to constantly monitor the winding position of the magnetic tape and be careful not to over-feed the tape. can be used for work.

Furthermore, since the mechanism according to the present invention is easy to operate and can be understood immediately by looking at it, there is an advantage that even customers who are unfamiliar with machines can easily handle it.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the appearance of a VTR embodying the present invention;
Figure 2 is an enlarged view showing the details of the main parts in Figure 1;
The figure is a plan view of the VTR in fast-forward mode, FIG. 4 is a four-dimensional diagram showing the configuration of an embodiment of the present invention, and FIG. 5 is a perspective view of the reel 12° 13 in FIG. It is. Explanation of symbols 1...Slide volume, 2...Cue switch, 11...Magnetic tape, 12...
...Feeding reel, 13...Take-up reel, 16A, 16B...Photo sensor agent Patent attorney Akio Namiki

Claims (1)

[Scope of Claims] 1) The feeding operation of the recording medium that is unwound from the first reel and wound onto the second reel is controlled at ), the first and second rotational speed detection means detecting the rotational speeds of the first and second reels, respectively, and A means for detecting the wound position of the recording medium, a means for presetting the cue position, and a comparison between the detected field by the detecting means and the setting output by the setting means, and when the two match, the recording medium is fed. 1. A cueing mechanism for a recording medium, comprising means for stopping the operation.