JPH1049807A - Magnetic recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve generation of noise due to overlapping wiring of the recorded signal generation when the recording is started in a magnetic recording apparatus by previously erasing the recorded signal before the start of the recording. SOLUTION: The tape is rewound so that the reserved recording start position is located to a total width erasing head 1 by a tape drive control circuit 9 immediately before the start of the recording. The recorded signal can be erased by operating the total width erasing head 1 and running the tape cassette 2 to run for the length longer than the distance up to the magnetic head 4 from the total width erasing heat 1. After the erasing operation, the tape is rewound again so that the reserved recording start position is located at the magnetic head 4 position to set into a standby state until the reserved recording is started.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording apparatus, and more particularly to a magnetic recording apparatus which is effective for timer recording.

[0002]

2. Description of the Related Art Timer reservation recording in a conventional magnetic recording apparatus will be described below.

FIG. 3 is a schematic diagram showing a configuration of a conventional magnetic recording apparatus. In FIG. 3, reference numeral 1 denotes a magnetic tape 1 to be described later.
2 is a full-width erasing head for erasing the video and audio signals recorded over the entire width of the tape. A magnetic head for recording on the tape 12; a reel base 5 built in the tape cassette 2 for rotating a reel around which the magnetic tape is wound;
Reference numeral 7 denotes a reel control circuit for controlling the rotation of the reel bases 5 and 6, and reference numeral 8 denotes a timer reservation circuit for setting timer reservation.

The operation of the conventional magnetic recording apparatus configured as described above will be described below.

First, a magnetic tape 1 which is a recorded tape
Reference numeral 2 denotes a full-width erasing head 1 for erasing all recorded video and audio signals, and a magnetic head 4 of a rotary cylinder 3 at the next stage.
Thus, a new video / audio signal is recorded on the magnetic tape 12. In such a device, when performing reservation recording, the timer reservation circuit 8 sets the date and time and the channel for which reservation recording is to be performed, and when the set date and time comes, the reel control circuit 7 drives the reel bases 5 and 6 to drive. The magnetic tape 12 is run, and the recording of the video and audio signals is performed by the magnetic head 4.

The recording state will be described with reference to the schematic diagram of FIG. In FIG. 4, P is the position of the magnetic head, Q is the position of the full-width erase head, S is the recording start position by the magnetic head, and T is the erase start position by the full-width erase head.

When setting reservation recording, the magnetic tape 12
Is loaded as shown in FIG. 4 (a). In FIG. 4A, when the set recording start date and time comes, the magnetic tape 12 starts running in the direction of arrow A, and erases the recorded signal by the full-width erasing head as shown in FIG. 4B. Meanwhile, the recording of a new video / audio signal on the magnetic tape 12 by the magnetic head 4 is started. At this time, a portion 12a where the already recorded signal and the newly recorded video / audio signal overlap is formed. If the recording is continued as it is, as shown in FIG. 4C, the erasure start position T will eventually exceed the magnetic head position P, and a portion (between P and T) where only a new video / audio signal is recorded will be formed.

[0008]

However, in the above-described conventional configuration, after recording is started, between the magnetic head position P and the erase head position Q, the recorded signal is not erased by the full-width erase head 1 but is erased by the magnetic head 4. A new video / audio signal is overwritten and recorded, which causes a problem that noise is generated by overwriting. As a countermeasure against this problem, there is a method of installing the magnetic head 4 and the full-width erase head 1 at an extremely short distance. An erase head different from the full-width erase head 1 is attached to the rotary cylinder 3 and this erase head is used. Although there is a method of erasing a portion that has not been erased by the full-width erasing head 1, the erasing head and a driving circuit are required, which has a problem that the cost is increased.

An object of the present invention is to solve the above-mentioned conventional problems, and to provide a magnetic recording apparatus in which noise caused by overwriting which occurs during a certain period of time after the start of reservation recording is improved at low cost. .

[0010]

In order to achieve this object, a magnetic recording apparatus according to the present invention comprises: a full-width erasing head for erasing a recorded portion of a magnetic tape; and a full-width erasing head on a running path of the magnetic tape. A magnetic head that is arranged at a later stage than the above and performs recording of a video and audio signal, and erases the video and audio signal recorded at least at a distance on the magnetic tape between the magnetic head and the full-width erasing head before recording starts. And a tape drive control circuit for controlling the drive of the magnetic tape so that the data is erased by a head. With this configuration, it is possible to obtain an inexpensive function of improving noise caused by overwriting which occurs for a certain period of time after the start of recording.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claims 1 and 2 of the present invention is directed to a full-width erasing head for erasing a recorded portion of a magnetic tape, and a stage subsequent to the full-width erasing head in a running path of the magnetic tape. And a magnetic head for recording a video / audio signal, the video / audio signal recorded at least at a distance on the magnetic tape between the magnetic head and the full-width erasing head before the start of recording. And a tape drive control circuit for controlling the drive of the magnetic tape so as to improve the noise caused by overwriting with a recorded signal generated for a certain period of time at the start of recording.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2, taking a timer reservation recording as an example.

(Embodiment 1) FIG. 1 is a schematic diagram showing the configuration of a magnetic recording apparatus according to the present invention. In FIG. 1, reference numeral 1 denotes a video / audio signal recorded on a magnetic tape 12 to be described later over the entire width of the tape. 2 is a tape cassette containing a magnetic tape 12, 3 is a rotary cylinder,
Reference numeral 4 denotes a magnetic head mounted on the rotary cylinder 3 for recording video and audio signals on the magnetic tape 12. Reference numerals 5 and 6 denote reel stands which are built in the tape cassette 2 and rotationally drive a reel around which the magnetic tape is wound. A reel control circuit for controlling the amount of tape movement by reading the number of rotations; a timer reservation circuit for calculating / controlling the start time of reserved recording;
Reference numeral 9 denotes a tape drive control circuit that controls the drive of the magnetic tape 12 by the timer reservation circuit 8 before the start of reservation recording. FIG.
FIG. 3 is a schematic diagram showing the state of the full-width erase head 1 and the magnetic head 4 on the magnetic tape 12.

The operation of the thus configured magnetic recording apparatus of the present embodiment will be described below.

First, the user inserts the tape cassette into the main body of the VTR and performs loading, and the timer reservation circuit 8 sets reservation recording. At that time, the positional relationship between the magnetic tape, the full-width erase head and the magnetic head is as shown in FIG.
When recording is started as it is, the portion between the magnetic head 4 and the full-width erasing head 1 is not erased by the full-width erasing head 1, and the already recorded signal and the newly recorded video / audio signal are recorded in an overlapping manner. And the image quality is disturbed.

Therefore, as shown in FIG. 2, after setting the timer reservation, the timer reservation circuit 8 calculates the reservation recording start time, and immediately before the start of the reservation recording, for example, 30 seconds before the recording starts, the tape drive control circuit 9 erases the full width. A command to rewind the magnetic tape 12 for the length L1 from the head position Q to the magnetic head position P is sent. Then, the reel control circuit 7 controls the reel base 5 to move the recording start position S to the full-width erase head position Q.
Then, the magnetic tape 12 is rewound in the direction of arrow B so as to come back (FIG. 2A).

After rewinding, the full width erasing head 1 is started, and the distance L from the full width erasing head position Q to the magnetic head position P is determined.
The magnetic tape 12 is moved in the direction of the arrow A for a distance L2 (Q to R) longer than 1 to erase a recorded signal in the L2 section of the magnetic tape 12 (FIG. 2B).

After erasing, the magnetic tape 12 is moved in the direction of arrow B by a distance L so that the recording start position S comes to the magnetic head position P.
Rewind for 3 minutes (FIG. 2 (c)).

Thereafter, when the scheduled recording start date and time comes, a new video / audio signal starts to be recorded from the recording start position S by the magnetic head 4 (FIG. 2 (d)).

As described above, according to the present embodiment, there is no overwriting of a recorded signal and a newly recorded video / audio signal which occur for a certain period of time after the start of reservation recording.
It improves the noise.

[0021]

As described above, according to the present invention, an excellent effect of improving the noise caused by overwriting at the start of scheduled recording can be obtained at a low cost without providing a new erase head separate from the full-width erase head. Can be

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a magnetic recording device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing positions of a tape cassette of a full-width erasing head and a magnetic head in the embodiment.

FIG. 3 is a schematic diagram showing a configuration of a conventional magnetic recording device.

FIG. 4 is a schematic diagram showing a state of a magnetic tape in a conventional magnetic recording device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 full width erasing head 2 tape cassette 3 rotating cylinder 4 magnetic head 5 supply reel 6 take-up reel 7 reel control circuit 8 timer reservation circuit 9 tape drive control circuit 12 magnetic tape

Claims (2)

[Claims] 1. A full-width erasing head for erasing a recorded portion of a magnetic tape, and a magnetic head disposed at a stage subsequent to the full-width erasing head on a running path of the magnetic tape and recording video and audio signals, And a tape drive control circuit for controlling the drive of the magnetic tape so that the erase head erases a video / audio signal recorded at least at a distance on the magnetic tape between the magnetic head and the full-width erase head before starting recording. A magnetic recording device, characterized in that: 2. A method for controlling a magnetic tape to erase a video and audio signal recorded at least at a distance between a magnetic head and a full-width erasing head on a magnetic tape before recording is started. And a newly recorded video / audio signal.