JPH0448460A - 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] Industrial applications The present invention allows for high-speed mode transition and high-speed tape forwarding.

The present invention relates to a magnetic recording/reproducing device equipped with a start/end detection function that can realize winding.

2. Description of the Related Art In recent years, high-speed operation and high-speed operability have been required for magnetic recording and reproducing devices.

In a conventional video tape recorder, a photo sensor is used to detect the beginning and end of the tape, and the process of detecting the beginning and end is always performed at regular intervals when the tape is running. Immediately after detecting the beginning and end, the mode transition process is performed and the mechanism is stopped.

Problems to be Solved and Attempted by the Invention However, in the above-mentioned conventional method for detecting the starting and ending edges, the starting and starting edges are detected constantly or at fixed time intervals while the tape is running, resulting in extremely poor processing efficiency and the difficulty in detecting the starting and ending edges. included a time error. Moreover, since the mode transition is started after detecting the beginning and end, there is a problem in that it takes time until the mechanism actually stops.

The present invention solves the above-mentioned conventional problems, and aims to provide a magnetic recording/reproducing device that detects the starting and ending edges only when necessary, can stop immediately after detecting the ending, and can shift to a high-speed mode. do.

Means for Solving the Problems In order to achieve this object, the magnetic recording and reproducing apparatus of the present invention winds up the tape sent out from the supply reel through a predetermined running path with the take-up reel, and winds the tape. a motor; a driving means for driving the motor;
a control means for controlling the motor; a rotation speed detection means for detecting the rotation speed of the reel; and a tape amount detection means for detecting the amount of tape wound on the reel from the rotation speed detected by the rotation speed detection means; a starting edge detecting means for detecting a starting edge in accordance with the tape amount detected by the tape amount detecting means; an operation mode setting means for setting an operation mode at the same time as the starting edge detecting means starts detecting the ending edge; and command sending means for sending a command to the control means for the operation mode set by the setting means.

According to the above-described structure, the present invention detects the remaining amount of tape wound on the reel from the rotational speed of the reel when the tape is running, and when the detected remaining amount of tape reaches a predetermined amount, start and end detection is started. At the same time, pre-processing is performed so that it can be stopped immediately after the start and end ends are detected, enabling high-speed operation.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a block diagram of a magnetic recording/reproducing apparatus according to an embodiment of the present invention.

In FIG. 1, 1 is a magnetic tape N, 2a is a supply reel, 2b is a take-up reel, 3 is a motor for rotating the take-up reel 2b, and 10a is a light emitting device for detecting the beginning and end of the tape. , 10b is a first light receiving device for detecting the end of the tape, and 10c is a second light receiving device for detecting the starting end of the tape.

Next, the control means 7 sends a rotation command for the motor 3 to the drive means 4 in accordance with the command sent from the command sending means 12,
The rotational speed of the motor 3 is controlled using rotational speed signals (hereinafter abbreviated as FG multiplied signals) detected by the rotational speed detection devices 5 and 6. Further, the drive means 4 supplies a drive signal to the motor 3, and the rotational speed detection devices 5 and 6 provide FG double signals corresponding to the rotational speeds of the supply reel 2a and the take-up reel 2b.The tape amount detection means 8 and the control means 7.

On the other hand, the tape amount detecting means 8 detects the remaining amount of the tape from the FG multiplied signal supplied from the rotational speed detecting device 5.6, and sends it to the end/start end detecting means 9. Furthermore, when the remaining amount of the tape reaches a predetermined amount, the end/start edge detection means 9 starts the end/start end detection process and supplies an operation start signal to the operation mode setting means 11. Immediately after the starting edge is detected, a starting edge detection signal is supplied to the operation mode setting means 11. Subsequently, the operation mode setting means 11 sets a mechanism stop mode using the operation start signal, and supplies a stop signal to the command sending means 12 upon arrival of the start/end detection signal. Further, the command sending means 12 sends a stop command to the control means 7 in response to a stop signal supplied from the operation mode setting means 11.

Note that a portion 30 surrounded by a dashed-dotted line is constituted by software within the microprocessor.

The operation of the magnetic recording/reproducing apparatus of this embodiment configured as described above will be explained with reference to FIGS. 1 to 3.

FIG. 2(a) is a graph showing the relationship between the reel radius and tape speed, and FIG. 2(b) is a graph showing the relationship between the amount of tape wound on the reel and the rotation period of the reel. Second
The method for detecting the remaining amount of tape will be explained with reference to FIGS. (a) and (b).

In the tape running state when the tape speed is constant, Fig. 2 (a)
As shown in FIG. 1, the tape speed is vl, the radius of the tape wound on the reel is R (hereinafter referred to as radius R), and the rotation period of the reel is T (hereinafter referred to as period T), then the following equation holds true.

R= (V/2π)・T (1) Therefore, since the tape speed V is constant, the radius R and the period T are in a proportional relationship, and the graph shown in Figure 2 (b) can be obtained. Recognize.

Here, in the configuration diagram shown in FIG. 1, the rotation period T can be obtained from the FG multiplied signal supplied from the rotation speed detection devices 5 and 6, and the tape speed (2) is constant depending on the operation mode and is a default value.

Therefore, in order to detect the remaining amount of tape, the tape amount detection means 8 actually detects the radius R of the tape wound on the reel from equation (1). The detected remaining amount of tape is stored in a specific memory and sent to the beginning/end detection means 9 via the memory.

Note that r in FIG. 2(a) is the hub radius of the reel, and R
wax is the maximum winding diameter.

Next, the beginning and end detection processing will be specifically explained. First, a signal is output to the light emitting device 10a to cause the light emitting device 10a to emit light. Next, the emitted light is transmitted to the light receiving device 10b.
, 10c, the electric signal is sent to the end/start end detection means 9.
Output to. That is, in the transparent portion of the tape at the beginning and end, the light from the light emitting device 10a passes through the tape and is received by the light receiving devices 10b and 10c. However, in the area where the magnetic tape 1 is located, the light is blocked by the magnetic tape 1, so that the light does not reach the light receiving devices 10b and 10c. Therefore, the starting and ending ends are detected by detecting the transparent portion of the tape.

Next, according to the flowchart of FIG.
．． Operation mode setting means 11. The operation of the command sending means 12 will be explained.

First, it is determined whether or not the beginning and end detection process is being executed in branch 200 using the beginning and end detection flag. If it is being executed, the process advances to processing block 207; if it is not being executed, the process advances to branch 201.

Branch 201 determines whether radius R is smaller than constant A. If it is smaller, the process proceeds to processing block 203, where an end detection flag is set, and the process block 204 sets the stop mode, and proceeds to the next process. Radius R is constant A
If it is larger, the process proceeds to branch 202, where it is determined whether the radius R is larger than the constant B. If it is larger, a start end detection flag is set in processing block 205, the stop mode is set in processing block 206, and the process moves to the next process.

By performing the above processing, it is possible to start end processing when the remaining tape amount reaches a predetermined amount, and by simultaneously stopping the operation mode, the next operation mode can be started immediately after the end end is detected. can move to. Here, the above constants A and B are A=r+α
...(2) B = Rwax-β
-(3) (2), (3) Expressions α and β depend on the accuracy of the rotational speed detection means 5 and 6 and the tape amount detection means 8 or the tape speed, but in this embodiment, 2[ ■ko〈 α〈3[−■ko
...(4) J [WI co〈 β
<2πmm
- (5) is set. If α, β (4)
, If the value is set to a value larger than the range satisfied by equation (5), the processing efficiency of end-edge detection will deteriorate, and if it is set to a small value, the mode transition will be delayed, making it no different from the conventional end-edge detection method.

When the beginning and end of the tape is being detected, a process block 207 performs a beginning and end detection process, and a branch 208 determines whether or not it is the end of the tape. If it is not the end, move on to the next process,
The above process is repeated until the starting and ending ends are detected.

If the end is detected, proceed to processing block 209;
A mechanical operation stop command is sent to the control means 7, and the start/end detection flag is reset in processing block 210. Next, in processing block 211, the next operation mode is set and the process moves on to the next process. By predicting and detecting the starting edge in this way, the processing efficiency of detecting the ending edge can be improved and the operation mode transition after detecting the ending edge can be performed at high speed.

As described above, according to this embodiment, the motor 3 that winds the tape, the drive means 4 that drives the motor 3, the control means 7 that controls the motor 3, and the rotation speed detection means that detects the rotation speed of the reel. 5, 6, the tape amount detection means 8, the beginning and end detection means 9, the operation mode setting means 11, and the command sending means 12, it is possible to efficiently detect the beginning and end. It can be stopped immediately and the mode can be changed quickly.

Effects of the Invention As is clear from the above description, the magnetic recording and reproducing apparatus equipped with the end-start detection method of the present invention detects the remaining amount of tape by calculating the tape winding diameter from the reel rotation period when the tape speed is constant. However, when the remaining amount of tape reaches a predetermined amount, it is configured to constantly detect the beginning and end of the tape and prepare to stop at the same time, so high-speed fast forwarding can be performed without damaging the tape.
Rewinding is possible, the starting and ending edges can be detected efficiently, and the starting and ending edges can be stopped immediately after the ending and the operation mode can be changed at high speed, which has a great practical effect.

[Brief explanation of drawings]

FIG. 1 is a flowchart of the main part of a magnetic recording/reproduction example according to an embodiment of the present invention. 3...Motor, 4...Driving means, 7...
Control means, 8...Tape amount detection means, 9...Tape end detection means, 11...Operation mode setting means, 1
2... Command sending means. Name of agent: Patent attorney Shigetaka Awano

Claims (1)

[Scope of Claims] The tape sent out from the supply reel is wound up by the take-up reel through a predetermined running path, and includes: a motor for winding the tape; a drive means for driving the motor; and a drive means for controlling the motor. a control means; a rotation speed detection means for detecting the rotation speed of the reel; a tape amount detection means for detecting the amount of tape wound on the reel from the rotation speed detected by the rotation speed detection means; and the tape amount detection means a starting edge detecting means for detecting a starting edge in accordance with a tape amount detected by a tape amount, an operation mode setting means for setting an operation mode at the same time when the ending edge detecting means starts detecting an end edge; a command sending means for sending a command to the control means for the selected operation mode.