JPH04330659A - Magnetic recording and reproducing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates primarily to a magnetic recording/reproducing apparatus typified by a VTR having a function of detecting the lifespan of a magnetic tape while the apparatus is in use.

0002

2. Description of the Related Art FIG. 4 is a diagram showing a magnetic tape running system in a conventional magnetic recording and reproducing apparatus. a tension control pin for adjusting the tension of the magnetic tape 2; 4 an erasing head for erasing signals recorded on the magnetic tape 2; 7 pulling out the magnetic tape 2 from the cassette 1; A guide roller 8 has a rotatable tape contact portion in order to run the magnetic tape 2 along the rotating magnetic head 9 that records signals by winding it around the tape. S slant pole that changes the running direction three-dimensionally, 10 is an inclined magnetic tape 2
11 is a control signal recording head for recording control signals and audio signals on the magnetic tape 2; 12 is a rotating magnetic tape 2 that pulls out the magnetic tape 2 using frictional force and sends it out; A rotatable pinch roller 14 that presses against the capstan shaft 13 is used to align the magnetic tape 2 with the pinch roller 12.
A pull-out pin 15 for pulling out the magnetic tape 2 from the cassette 1 is located inside the cassette 1 and is a reel for winding the magnetic tape 2.

[0003] Next, the operation of the above configuration will be explained. As for the running state of the magnetic tape when the magnetic tape is loaded in the magnetic recording/reproducing device, first, when the magnetic tape 2 is fed out from the cassette 1, the tape tension control pin 3, the erasing head 4, the S slant pole 8, It is in sliding contact under tension with the rotating magnetic head 9, T-transpol 10, control signal recording head 11, etc., and is in rotating contact with the guide roller 7, while being in contact with the pinch roller 12 and capstan shaft 13. It is crimped, pulled, fed out, and wound onto the reel 15 inside the cassette 1.

0004

[Problems to be Solved by the Invention] In the conventional magnetic recording and reproducing apparatus configured as described above, when the magnetic tape is repeatedly used under tension, it becomes difficult to connect with various fixed guides and heads. Contact increases the coefficient of friction. When the coefficient of friction increases, the frictional resistance force at the sliding contact area increases, and the running resistance of the tape becomes excessive.
There have been disadvantages such as the pressure force between the capstan shaft and the pinch roller alone cannot pull the magnetic tape completely, making it impossible for the tape to run.

[0005] This invention was made to solve the above-mentioned problems, and the deterioration rate of the magnetic tape during running can be determined by detecting the change in the coefficient of friction between the fixed post and the magnetic tape. Detects the lifespan of the magnetic tape inside,
It is an object of the present invention to provide a magnetic recording/reproducing device having a function of determining the usable limit of a magnetic tape.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a fixed post in the magnetic tape running system that changes the running direction of the magnetic tape while regulating the vertical running position of the magnetic tape. At the same time, a pair of rotating posts are arranged in front and behind the fixed post, and the pair of rotating posts has a rotating roller that rotates with low frictional force while receiving side pressure due to the tension of the magnetic tape, and a rotating roller that rotates with low frictional force while receiving side pressure due to the tension of the magnetic tape. It consists of a measuring shaft that distorts according to the lateral pressure of the measuring shaft, and a strain sensor that is attached near the mounting part of the measuring shaft and converts the distortion into an electrical signal and calculates it to determine the tape tension. The present invention is characterized in that it is equipped with an alarm means when the coefficient of friction obtained from the ratio of the tape tension before and after the post exceeds a preset tape use limit value.

[0007]

[Operation] According to the present invention, when the rotating rollers of the rotating posts disposed before and after the fixed post are subjected to lateral pressure due to the tension of the magnetic tape before and after the fixed post in the magnetic tape running system of the magnetic recording and reproducing device, the rotating roller Distortion occurs in the measurement axis depending on the lateral pressure from the The strain caused by the tape tension on the measurement axis is converted into an electrical signal by the strain sensor. This electrical signal is calculated to determine the tape tension, and the friction coefficient of the magnetic tape is determined from the ratio of the tape tension before and after the fixed post.If this friction coefficient exceeds a preset tape use limit value, an alarm is issued. Since an alarm is emitted from the means, this can be known as the tape's usage limit.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a running system diagram of a magnetic tape in a magnetic recording and reproducing apparatus of the present invention, FIG. 2 is a detailed diagram of a magnetic tape tension detection section, and FIG. 3 is a detailed diagram of a rotating post that detects the tension of a magnetic tape. In these drawings, the same reference numerals are given to the same or corresponding parts as in FIG. 4 showing the conventional example, and detailed explanation thereof will be omitted.

In FIG. 1, reference numeral 5 denotes a pair of rotating posts that are rotatably disposed before and after a fixed post 6, and the rotating posts 5, 5 and the fixed post 6 constitute a magnetic tape tension detection section. has been done.

Specifically, the rotating post 5 is composed of a rotating roller 51, a measuring shaft 52, and a strain sensor 53, as shown in FIG. The measuring shaft 52 rotates with a low frictional force while receiving the rotational pressure, and the measuring shaft 52 is distorted according to the side pressure from the rotating roller 51. In addition, the strain sensor 53
is pasted near the attachment of the measuring shaft 52, and has a function of converting the distortion due to the tension of the magnetic tape of the measuring shaft 52 into an electrical signal. Furthermore, the fixed post 6 is
The running direction of the magnetic tape 2 is changed while regulating the running position of the magnetic tape 2 in the vertical direction.

The basic running of the magnetic tape due to the operation of the above structure is basically the same as that of the conventional example, so a detailed explanation thereof will be omitted.

Next, measurement of magnetic tape tension will be explained. As shown in FIG. 3, in order to measure the tension of the magnetic tape, there is a side pressure (F1, F2) occurs. A strain corresponding to the lateral pressure is generated in the mounting portion of the measurement shaft 52, and the strain sensor 53 converts the generated strain into an electrical signal and calculates it to determine the tension of the magnetic tape 2.

Similarly, the tension of the magnetic tape 2 at the position of the other rotating post 5 is measured, and the coefficient of friction of the magnetic tape 2 is determined from the ratio of the tensions of the front and rear magnetic tapes 2. If the calculated friction coefficient exceeds a preset value, an alarm (not shown) will issue an alarm or the magnetic recording/reproducing device will be stopped. Also,
The relationship between the friction coefficient between the magnetic tape 2 and the fixed post 6 and the tension of the magnetic tape 2 is expressed by the following equation.

[0014]

[Math 1]

However, in the above formula, T1 = Tension on the traveling direction side of the magnetic tape T2 = Tension on the rear side of the magnetic tape e = Base of natural logarithm μ = Coefficient of friction between the magnetic tape and the fixed post θ = The magnetic tape and Shall indicate the frictional contact angle between fixed posts.

Example 2 In Example 1 above, the axial strain of the rotating post was measured to measure the coefficient of friction. However, even if a piezoelectric element is used in the shaft or a piezoelectric element is used in the attachment part of the shaft, the above example It has the same effect as.

[0017]

[Effects of the Invention] As explained above, according to the present invention, the usage limit of a magnetic tape can be detected in advance, so that an alarm is issued to notify when the magnetic tape is nearing the end of its life. This has the effect of preventing serious accidents such as the stoppage of the magnetic tape during use.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a magnetic recording/reproducing apparatus which is an embodiment of the present invention.

FIG. 2 is a detailed view of a rotating post for magnetic tape tension detection.

FIG. 3 is a detailed diagram of a magnetic tape tension detection section.

FIG. 4 is a diagram of a conventional magnetic tape running system.

[Explanation of symbols]

1 Cassette 2 Magnetic tape 3 Tension control pin 4 Erasing head 5 Rotating post 6 Fixed post 51 Rotating roller 52 Measurement axis 53 Strain sensor

Claims (1)

[Claims] Claim 1: A fixed post is provided in a magnetic tape running system to change the running direction of the magnetic tape while regulating the vertical running position of the magnetic tape, and a pair of rotating posts are provided in front and behind the fixed post. The above-mentioned pair of rotating posts includes a rotating roller that rotates with low frictional force while receiving lateral pressure due to the tension of the magnetic tape, a measuring shaft that is distorted in response to the lateral pressure from the rotating roller, and a mounting portion for this measuring shaft. It consists of a strain sensor attached nearby that converts the strain into an electrical signal and calculates it to determine the tape tension. 1. A magnetic recording and reproducing device comprising: a warning means for when a set tape usage limit value is exceeded.