JPS62134801A - Magnetic recording device - Google Patents

Abstract

PURPOSE:To attain information recording with enhanced definition near the end part of a magnetic recording medium without affecting the protection function of the recording medium by recording information at changed levels of a recording signal when the end of the magnetic recording medium is detected. CONSTITUTION:When a tape is supplied from a reel and travels in the direction where the tape is wound by another reel and when a recording failure part at the former reel side passes through a tape end sensor 1, the sensor 1 outputs a signal at 'H'. At that time, the output from an inversion signal generator 8 to a NOR gate 13 is at 'L', and the output of the gate 13 rises at 'H', and a differentiation circuit 16 gives a trigger signal to a one-shot circuit 7 and a voltage generator 5. The output of the generator 8, which is supplied to the UP/DOWN terminal of the generator 5 is at 'L', and the value of a voltage signal is dropping until said output comes to 'H'. Accordingly the level of the recording signal drops to fade out the recording signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording device, and particularly to a magnetic recording device using a tape-shaped magnetic recording medium.

[Prior Art] In a conventional magnetic recording device of this type, a tape-shaped magnetic recording medium (hereinafter simply referred to as tape) runs while being suspended between a supply reel and a take-up reel. , fit the reels into a reel holder, etc.
By properly engaging and rotating the reel holder,
The tape is guided from the supply reel through a predetermined path by a guide post or the like to a position facing the recording head, and is pulled and wound by a take-up reel. Further, such a tape is provided with a non-recordable portion such as a part of the leader at the beginning and end of the tape in order to protect the tape and fix it to the reel.

Conventional magnetic recording devices that use such tapes protect the tape by immediately canceling the recording state when the boundary between the tape and the unrecordable area is detected during recording. be.

[Problems to be Solved by the Invention] However, in conventional magnetic recording devices, when the end of the tape is detected, recording of the recording signal for recording information on the tape is abruptly interrupted. Therefore, there is a problem in that tapes recorded in the conventional manner feel very unnatural when played back, and the quality is degraded.

SUMMARY OF THE INVENTION An object of the present invention is to solve this problem and provide a magnetic recording device that can record information with enhanced quality even near the tape ends without impeding the tape protection function.

[Means for Solving the Problems] The magnetic recording device of the present invention includes a running means for running a tape-shaped magnetic recording medium along a predetermined route, and recording on the magnetic recording medium running along the predetermined route. a recording means;
The magnetic recording medium is equipped with a detection means for detecting the edge of the magnetic recording medium, and a means for recording by changing the level of the recording signal from the previous level when the edge is detected.

[Function] According to the above configuration, it is possible to stop or start recording by appropriately processing the recording signal without abruptly stopping or starting recording at the end of the tape-shaped magnetic recording medium. This makes it possible to improve recording quality.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows, as an embodiment of the present invention, an example of the configuration of a tape running mechanism in a VTR to which the present invention can be applied. Here, k is a tape as a magnetic recording medium, g is a cassette containing tape k, and C and m are reels provided in cassette g. h is a drum equipped with a magnetic head for performing magnetic recording on tape k, and a to f are reels f.
This is a guide post for guiding the tape k between the tape k and the spatula h. In addition, 1 and 2 are respectively,
This is a tape end sensor (tape end sensor) installed on the reel °C and m sides.For example, when facing a tape coated with a magnetic material, it sends an L level signal, and when the tape is coated with a magnetic material on both ends of the tape, It outputs an H level signal when facing an unrecordable part such as a part of the reader that is not loaded.

FIG. 2 shows an example of the configuration of the main part of the present invention.

Here, 3 is a tape running direction detection circuit, and the reel l
A signal F/R indicating the tape running direction is generated by detecting the direction of rotation for 9 m. 4 is a recording signal generation circuit that generates a recording signal to be recorded on the tape k. Reference numeral 5 denotes a voltage generator, which changes the voltage signal output from its output terminal 011T during fade-in and fade-out of information. A fader circuit 6 changes the level of a recording signal according to the voltage signal from the voltage generator 5 and supplies it to the recording circuit 11. The recording circuit 11 includes a recording amplifier,
The amplified recording signal is supplied to the magnetic head of the drum h.

IO is a tape speed selector that can set the tape running speed to either high or low, and generates an information signal regarding the tape speed depending on the setting.

7 is a one-shot circuit whose trigger input terminal TR
It operates on the rising edge of a signal input to the IG, and outputs an H level signal from its output terminal OUT for a predetermined period of time.

This predetermined time is determined based on the running direction information signal F/R supplied from the tape running direction detection circuit 3 and the tape speed information signal TC supplied from the tape speed selector 10. , the time immediately before the magnetic head traces the joint between the part coated with the magnetic material and part of the leader is determined.

8 is an inverted signal generation circuit whose trigger input terminal TR
It operates on the falling edge of the signal input to IG, and continues to output an H level signal from the output terminal 01JT until there is a signal input at the reset input terminal RESET. This signal is led to the input terminal UP/DOWN of the voltage generator 5, and depending on the level of the signal, that is, whether it is H level or L level, the potential of the voltage signal outputted by the voltage generator 5 is raised or lowered. is selected. Also, at this time, the tape speed information signal from the tape speed selector 10 is introduced to the input terminal TC of the voltage generator 5, and a time is set for changing the potential according to the tape speed.

Reference numeral 9 denotes an inversion mode selector for selecting whether or not to perform an inversion (reverse) operation on the tape. When the inversion mode is selected, the output signal of the one-shot circuit 7 is passed through to trigger the inversion signal generation circuit 8. Leads to input terminal TRIG.

12 is a NOR gate that receives the detection output signals of tape end sensors 1 and 2; 13 is a NOR gate that receives the NOR gate output signal and the output signal of the inverted signal generator 8; and 16 is a differential gate for the NOR gate output signal. 14 is an OR gate that receives the differentiated output signal and the output signal of the inverted signal generator 8;
The gate output signal is supplied to the one-shot circuit 7 and the trigger input terminal TRIG of the voltage generator 5. Also, N
The output of the OR gate 12 is also supplied to the reset terminal RESET of the inversion signal generator 8.

15 rotates the tape k in the forward direction (forward rotation) or in the reverse direction (reverse rotation)
This is a controller (mechanism controller) of the traveling mechanism for making the vehicle travel in the same direction, and switches the traveling direction according to the output of the reversal signal generator 8.

In this configuration, it is assumed that the tape k is supplied from the reel °C and runs in the direction in which it is wound onto the reel m. Here, the unrecordable part on the reel A side is tape end sensor 1.
When the sensor 1 passes through, the sensor 1 outputs an H level signal.

At this time, the output of the inverted signal generator 8 to the NOR gate 13 is at the L level, and therefore the output of the NOR gate 13 rises to the H level. A triggered signal is given.

At this time, the output of the inverted signal generator 8 supplied to the UP/DOWN terminal of the voltage generator 5 is at L level, so
During the time it takes to reach the level, the value of the voltage signal decreases, and the level of the recording signal decreases. That is, when the tape k approaches the end, the recording signal is faded out.

When the trigger signal is input manually, the one-shot circuit 7 outputs an H level signal for a time determined according to the running direction information signal and the tape speed information signal, and when the time elapses, the output signal becomes L level. Reverse mode selector 9
When is set to the inversion mode, this signal change is supplied to the inversion signal generator 8, and when the signal becomes L level, the output signal of the inversion signal generator 8 becomes H level.

In response to this, the mechanism controller 15 starts reversing the running direction, and the one-shot circuit 7 again
However, this is because the traveling direction information signal F/R is inverted at this time, and the time during which the one-shot signal is at the H level is different from that during normal rotation.

In the voltage generator 5, since the output signal of the inverted signal generator 8 applied to the LIP/DOWN terminal is at H level when inverted, the value of the generated voltage signal is increased over a predetermined period of time. This causes the recording signal to fade in near the beginning of the tape.

That is, when performing reversal control when the tape end is detected, recorded information is faded out and faded in before and after the reversal, respectively.

When the running direction of the tape is reversed and the magnetic material passes through the sensor 1 again, the output of the sensor 1 changes from the H level to the L level, and in response to this, the NOR gate 1
A reset signal is manually input from 2 to the inverted signal generator 8.

Furthermore, when the tape k is wound sideways from the reel m to the reel □, and when the boundary between the magnetic material and the leader section passes through the sensor 2, the same operation as described above is repeated according to the detection output of the sensor 2. .

In this way, conventionally the video and audio were abruptly cut off near the end of the tape, spoiling the atmosphere during playback, but with this example, for example, the video is gradually made whiter or It is possible to perform processing such as making the video black or gradually decreasing or increasing the volume of the audio, so that the ending seam does not feel strange.

In addition, conventionally, recording was not performed on the tape section from the boundary with the unrecordable section at the end to the head, but in this example, this section is used to perform recording processing for fade-in and fade-out. I decided to do this, so
Tape usage efficiency can be maximized.

Note that the present invention can be applied to a magnetic recording device that uses any kind of tape-shaped magnetic recording medium, or a magnetic recording device that records any recording signal such as an image signal or an audio signal.

For example, when the present invention is applied to an audio magnetic recording device capable of reverse recording, the problem of the audio signal suddenly cutting off before the tape is reversed and rising suddenly after the reversal is solved, and the volume drops immediately before the reversal. After the reversal, the volume gradually increases, which does not cause discomfort to the user and improves quality. Also in this case, it is possible to make maximum use of recordable areas that could not be used in the past.

[Effects of the Invention] As explained above, according to the present invention, a magnetic recording device is provided which is capable of recording information with enhanced quality even near the edge of the tape without impairing the function of protecting the tape. realizable.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of the structure of a tape running mechanism in a magnetic recording apparatus to which the present invention can be applied, and FIG. 2 is a block diagram showing an example of the structure of the main part of the present invention. 1.2... Tape end sensor, 3... Tape running direction detection circuit, 4... Recording signal generation source, 5... Voltage generator, (i... Fader circuit, 7... One shot circuit, 8... inversion signal generator, 9... inversion mode selector, 10... tape speed selector, 11... recording circuit, 15... mechanism controller.

Claims (1)

[Scope of Claims] Running means for running a tape-shaped magnetic recording medium along a predetermined route; recording means for recording on the magnetic recording medium running along the predetermined route; and an edge of the magnetic recording medium. What is claimed is: 1. A magnetic recording device comprising: detecting means for detecting the end; and means for causing recording by changing the level of a recording signal from the previous level when the end is detected.