JPH04129484A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To always obtain a best reproduction signal by discriminating by which of the VHS recording or the S-VHS recording system the signal is recorded and revising the tracking to be an optimum tracking fixed value depending on the result of discrimination so as to match the tracking with the optimum tracking value automatically. CONSTITUTION:While the operation of detecting a tracking to maximize a reproduction signal level is fixed attended with the start of reproduction, a head amplifier 13 inputs a reproduction signal to a VHS/S-VHS discrimination circuit 17, in which the system is discriminated and the result is inputted to a microcomputer 16. The microcomputer 16 detects a tracking maximizing the reproduction level and gives a command to a servo circuit 12 so that the tracking is fixed to a ratio of a tracking fixed value in response to the system based on the information from the VHS/S-VHS discrimination circuit 17. Thus, a ratio of the tracking fixed value is selected automatically so that the tracking is matched with an optimum point of a tape of the VHS recording and S-VHS recording.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a magnetic recording and reproducing device capable of reproducing both the VHS system and the 5-VHS system. The present invention relates to an improvement in an automatic tracking adjustment device that detects and automatically controls tracking so that the reproduced signal level is at or around the maximum level.

[Conventional technology]

FIG. 2 is a configuration diagram showing an automatic tracking device for a conventional magnetic recording/reproducing device. 2.3 picks up the reproduced signal while tracing the recording track recorded on the magnetic tape 7. A head amplifier circuit 13 amplifies the reproduced signal picked up by the rotating head 2.3. 1
4 is a detection circuit which detects the amplified reproduced signal and converts it into a DC voltage. 15 is an A/D conversion circuit which converts the above DC voltage into a digital signal and inputs it to the microcomputer 16. ■2 is a servo circuit, which drives the capstan motor 9 through the capstan drive circuit 104.
Also, the drum motor 4 is driven through the drum motor drive circuit 11.
The speed and phase of the tram are controlled, and the relative position between the coretroll pulse picked up by the command of the microcomputer 16 and the PC pulse corresponding to the phase of the rotating tram 1 outputted from the PG head 5 is adjusted. Automatically performs tracking adjustment.

Next, the operation of the above configuration will be explained. At the start of reproduction, the microcomputer 16 designates an initial tracking value to the servo circuit 12. At this time, the level of the reproduced signal picked up by the rotating heads 2 and 3 is measured by the head amplifier 13, the detection circuit 14. It is input to the microcomputer 16 through the A-D conversion circuit 15 and stored in the memory.Then, the microcomputer 16 converts the servo circuit 1 into
After the servo system is stabilized, the reproduction signal level is similarly stored in the microcomputer 16. The above operation is repeated to increase or decrease the tracking value, and the tracking value is detected so that the reproduced signal level is at or near the maximum, and is fixed at the optimum tracking value. Generally, the optimal tracking value is VHSH3
Recording tape - VHSH3 recording tape The values are different, and this is especially noticeable in EP mode.

FIG. 3 is a graph showing the relationship between the reproduced signal output level and the tracking phase. In this case, the tracking fixing range obtained by the above operation is 8 points from point A, and the tracking value is fixed to 0 point between them. At this time, AC:
The BC ratio is determined to give the best image quality; for example, the ratio is 2:6 for VHSH3 recording tape.
5-VH8 records show 3 out of 5. Conventionally, the ratio was determined depending on which method was prioritized; for example, 5-VH
If the ratio is 3:5 with emphasis on the VHSH3 recording tape, the VHSH3 recording tape would not be at the optimal point either.

[Problem to be solved by the invention]

Since the automatic tracking adjustment device of the conventional magnetic recording/reproducing device is configured as described above, there is only one ratio of tracking fixed values for the 5-VHSH3 recording tape H3H3 recording tape, so the ratio of the fixed tracking values is fixed. had problems such as not necessarily being able to obtain the best image quality.

This invention was made to solve the above-mentioned problems, and the ratio of fixed tracking values is automatically switched so that the tracking value matches the optimum point of each tape for VHS recording and 5-VHS recording. The purpose is to obtain a magnetic recording/reproducing device that can perform the following steps.

[Means to solve the problem]

According to the magnetic recording and reproducing apparatus according to the present invention, it is configured to determine whether the reproduced signal is VHS recording or 5-VH8 recording and automatically change the ratio of tracking fixed values within the tracking range. It is something.

[Effect]

According to this invention, since the ratio of tracking fixed values is automatically switched when playing either the VHS system or the 5-VHS system, it is possible to fix the optimal tracking value for tapes of either system.

〔Example〕

Embodiments of the invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an automatic tracking device for a magnetic recording/reproducing apparatus according to an embodiment of the present invention.

In this FIG. 1, since 1 to 16 are the same as those in the conventional example shown in FIG. 2, the same reference numerals are given and detailed explanation thereof will be omitted. 17 uses the reproduced signal from the head amplifier 13 to determine, for example, by looking at the frequency of the FM envelope, that if the 5 MHz component is above a predetermined level, it is the 5-VHD system, and if not, it is the VH8 system.
This is an HS/5-VHS discrimination circuit.

Next, the operation of the above configuration will be explained. The operation up to the detection of the tracking value at which the reproduction signal level becomes the maximum upon the start of reproduction is the same as that described in the description of the conventional example, and therefore will not be described here.

Until the above operation is completed, the head amplifier 13 inputs a reproduced signal to the VHS/5-VHSH3 discrimination circuit 17 to discriminate the system, and the resulting information is input to the microcomputer 16. Microcomputer 1
6 detects the playback level or the maximum tracking value,
When fixing the tracking value, if the information from the VHS/5-VH8 discrimination circuit 17 is a VHS system, it is the ratio of the tracking fixed value of the VHS system, and if it is a 5-VHS system, it is 5.
- Issue a command to the servo circuit 12 to fix the tracking to the ratio of the tracking fixed value of the VHS system.

In the above embodiment, only the automatic tracking adjustment was shown, but if the playback signal method changes from VHS to 5-VHS or vice versa during playback, the tracking value at which the playback signal becomes maximum is stored in memory. If this is done, it is of course possible to change the fixed tracking value from the VHS system tracking fixed value ratio to the 5-VHS system tracking fixed value ratio, or vice versa. Furthermore, if the reproduction signal method changes,
The tracking value at the optimal point may be fixed by performing automatic adjustment again from that point.

Further, in the above embodiment, only the VHS system and the 5-VH8 system have been described, but the invention can also be applied to the β system, high band β system, etc., and the same effects as in the above embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the magnetic recording and reproducing apparatus according to the present invention, it is determined whether recording was performed using VHS recording or 5-VHS recording, and the optimal tracking fixed value is changed according to the determination result. As a result, the tracking value can be automatically adjusted to the optimum tracking value regardless of whether the tape is VHS recorded or 5-VHS recorded, and the best reproduction signal can always be obtained.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an automatic tracking device for a magnetic recording/reproducing device according to an embodiment of the present invention, FIG. 2 is a configuration diagram showing an automatic tracking device for a conventional magnetic recording/reproducing device,
FIG. 3 is a diagram showing the relationship between the reproduced signal output level and the tracking phase. In the figure, ■ is a rotating drum, 2.3 is a rotating head, 1
3 is a head amplifier circuit, 14 is a detection circuit, 15 is A-D
Conversion circuit, 16 is a microcomputer, 12 is a servo circuit, 10 is a capstan drive circuit, 9 is a capstan motor, 11 is a drum motor drive circuit, 4 is a drum motor, 5 is a PG head, 17i;! This is a VHS/5-VHS discrimination circuit. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) A means for reproducing both the VHS system and the S-VHS system, a means for changing the tracking of the servo circuit in the forward and reverse directions, and the above-mentioned means so that the reproducing signal from the rotating head is at the maximum or in a range close to it. In a magnetic recording and reproducing device comprising a means for fixing tracking and a means for determining whether a reproduced signal from a rotary head is a VHS system or an S-VHS system, the tracking fixing position is determined according to a determination result of the system determining means. A magnetic recording/reproducing device characterized in that it is fixed at different positions for a VHS system and an S-VHS system.