JPH0461601A - 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 relates to a magnetic recording/reproducing device such as a VTR.

2. Description of the Related Art Conventionally, recording and reproducing apparatuses using magnetic tape as a recording medium, including VTRs, have been developed and put into practical use. In recent years, due to demands for higher image quality in the field of video equipment and rapid advances in semiconductors, research has begun on digital VTRs that record video signals as digital data on magnetic tape, and are beginning to be put into practical use. When video signals are digitized, the data rate becomes extremely high, and if the recording and reproducing thread is considered as one transmission path, a broadband transmission path is required.

On the other hand, - research progresses in the field of magnetic tape, and MP, ME
Magnetic tapes with better characteristics have been developed. In addition to conventional longitudinal recording media that record in the in-plane direction of a tape, perpendicular recording media that record in the perpendicular direction of the tape have recently begun to be developed. Due to the nature of magnetic recording, perpendicular magnetic recording media are essentially capable of recording at shorter wavelengths than longitudinal magnetic recording media. In addition, the recording/reproducing system as a transmission path generally has a wider band if a perpendicular magnetic recording medium is used.

FIG. 2 is a block diagram of a conventional digital VTR. In FIG. 2, the video signal to be recorded is applied to a digital processing record 4 via a video signal input terminal 13, and is subjected to digital processing such as compression and modulation by a digital processor I4. For example, a magnetic head 17 mounted on a rotating cylinder 16 passes through an analog processor 15 that performs analog processing such as D-A conversion and analog modulation.
is applied to The magnetic head 17 records signals on the magnetic tape while rotating on the rotating cylinder 16.

Further, during reproduction, the signals read from the magnetic tape by the magnetic head 17 are processed by the analog processor 15 and the digital processor 14, and then output from the video signal output terminal 18.

In this series of operations, the rotation of the rotary cylinder 16 is controlled by the rotation control section 19, but the cylinder rotation speed is constant regardless of the type of magnetic tape, and the rotation speed of the cylinder is constant regardless of the type of magnetic tape. The recording wavelength remains constant.

Problems to be Solved by the Invention However, with the above method, it is not possible to change the shortest recording wavelength or reproduction wavelength equalization amount depending on the type of magnetic tape, and it is difficult to use high-density recording such as perpendicular recording media. A problem arose in that it was not possible to fully cope with the potential capabilities of magnetic tape.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and it is possible to set recording conditions that fully utilize the characteristics of magnetic tape, and to perform optimal reproduction signal processing. The purpose is to provide a recording/playback device.

Means for Solving the Problems The present invention provides a magnetic recording and reproducing apparatus that records and reproduces information on a magnetic tape using a magnetic head provided on a rotating cylinder controlled by a rotation controller. When reproducing, if no data is recorded on the magnetic tape, temporary data is recorded on the magnetic tape and reproduced, or if data is recorded on the magnetic tape, the data is reproduced and the tape discrimination means for evaluating frequency components based on data and determining frequency characteristics of the magnetic tape as a transmission path; recording condition determination means for determining specific recording conditions based on the frequency characteristics of the tape discrimination means; and recording condition determination means for determining specific recording conditions based on the frequency characteristics of the tape discrimination means. Recording condition setting means for setting the recording conditions of the rotation control unit based on the input recording conditions input by the recording condition input means for inputting the specific recording conditions or the recording conditions of the means, and the discrimination result of the tape discrimination means. and reproduction optimization means for selecting optimal reproduction signal processing based on the recording conditions set by the recording condition setting means.

In the present invention, when recording and reproducing the magnetic tape using a magnetic disc, if no data is recorded on the magnetic tape, the tape discriminating means records provisional data on the magnetic tape and reproduces it; Alternatively, if data is recorded on the magnetic tape, the data is reproduced, frequency components are evaluated based on the data, frequency characteristics of the magnetic tape as a transmission path are determined, and recording condition determining means is provided. The recording condition setting means determines a specific recording condition based on the frequency characteristics of the tape discrimination means, and determines the specific recording condition or the input recording condition inputted by the recording condition inputting means for inputting the recording condition. sets the recording conditions for the rotation control section. Therefore, in the recording operation, recording is possible under recording conditions that fully utilize the characteristics of the magnetic tape. In addition, in the playback operation, the tape discrimination means determines the frequency characteristics of the magnetic tape as a transmission path, and in addition,
The playback optimization means selects the optimum playback signal processing based on the discrimination result of the tape discrimination means and the recording conditions set by the recording condition setting means, so that the playback optimization means can perform the optimum playback signal processing. An embodiment of a magnetic recording/reproducing apparatus according to the present invention will be described with reference to the drawings.

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

This embodiment exemplifies the case of a digital VTR.

When recording and reproducing the magnetic tape using the magnetic head 5, if no data is recorded on the magnetic tape, the tape discriminating means 8 records provisional data on the magnetic tape and reproduces it, or records provisional data on the magnetic tape. If the data has already been recorded, the data is reproduced, the frequency components are evaluated based on the data, and the frequency characteristics of the magnetic tape as a transmission path are determined.

The recording condition determining means 9 determines, for example, the lower limit of the shortest recording wavelength, as a specific recording condition of the magnetic tape to be used, based on the frequency characteristics determined by the tape discriminating means 8.

The recording condition setting means 7 sets the recording conditions based on the specific recording conditions determined by the recording condition determining means 9 or the appropriate conditions following the specific recording conditions inputted by the user using the recording condition input means IO. For example, the rotation speed of the rotary cylinder 4, the track width of the magnetic tape used, etc. are set.

The playback optimization means 11 selects the optimum playback signal processing based on the discrimination result of the tape discrimination means 8 and the recording conditions set by the recording condition setting means 7, and sends this selection information to the analog processor 3. be.

Next, the operation during recording will be explained.

In FIG. 1, a video signal to be recorded is applied to a digital processor 2 via a video signal input terminal l, and after digital processing such as signal compression and modulation is performed by the digital processor 2, The signal is applied to a magnetic head 5 mounted on a rotary cylinder 4 through an analog processor 3 that performs analog processing such as DA conversion and analog modulation. The magnetic head 5 records signals on the magnetic tape L while rotating on the rotating cylinder 4. At this time, the rotation cylinder 4 is controlled by the rotation control section 6 to rotate at the rotation speed set by the recording strip f'+setting means 7.

Here, the operation of the tape discrimination means 8 will be explained.

The tape discrimination means 8 determines the frequency characteristics of a transmission path when a signal is recorded and reproduced on a magnetic tape.

The magnetic tape that has been loaded and wound around the rotating cylinder 4 is first judged by the strength of the magnetic flux detected by the magnetic head 5 mounted on the rotating cylinder 4 as to whether or not a signal is recorded on the part of the tape that is wound around the cylinder. .

If no signal is recorded on the cylinder-wrapped portion of the tape, the rotary cylinder 4 rotates and the tape remains stationary, and the magnetic head 5 temporarily records data in the same format as the video signal recording data having multiple frequency components. By recording and reproducing data on a magnetic tape and evaluating each frequency component of the reproduced output, the frequency characteristics of the recording and reproducing system as a transmission path are determined. Note that the temporary data is erased by the erase head after determining the frequency characteristics.

If a signal is recorded on the cylindrical winding portion of the tape, the frequency characteristics of the recording and reproducing system as a transmission path are determined by reproducing the tape and evaluating each frequency component of the reproduced output.

Based on the frequency characteristics determined as described above, the recording condition determining means 9 determines, for example, the lower limit of the shortest recording wavelength as the recording condition for the magnetic tape used. The user selects an appropriate lower limit or higher recording condition,
Recording conditions are determined by inputting information to the recording condition setting means 7 from the recording condition inputting means IO. At this time, by selecting the lower limit of the recording conditions, the highest recording density for the magnetic tape used can be achieved. Moreover, by selecting conditions equal to or higher than the lower limit, although the recording density becomes lower, more stable high image quality can be achieved. The recording conditions determined in this way are sent to the rotation control section 6, and the rotation speed of the rotary cylinder 40 is set and operated based on the determined recording conditions. The rotation speed information at this time is recorded on the magnetic tape as data.

Next, the operation during playback will be explained.

First, the rotating cylinder 4 starts rotating at a predetermined rotational speed. The magnetic head 5 reads rotation speed data recorded on the magnetic tape. The rotation speed data is sent to the rotation control section 6 through the tape discrimination means 8, and the rotation control section 6 changes the rotation speed of the rotary cylinder 4 based on the rotation speed data. The rotating cylinder 4 is rotated at this rotational speed to reproduce the magnetic tape, and the tape discrimination means 8 evaluates each frequency component of the reproduced output in the same way as when a signal is recorded on the tape winding part during recording. By this, the frequency characteristics of the recording/reproducing system as a transmission path are determined. The reproduction optimization means 11 selects the optimum reproduction signal processing based on the shortest recording wavelength based on the rotation speed data and the frequency characteristics of the transmission path, and sends the selection information to the analog processor 3. Based on the selection information, the analog processor 3 processes the reproduced signal from the magnetic head 5. After being further processed by the digital processor 2, it is output from the video signal output terminal 12.

In this embodiment, as a tape discrimination means, the frequency characteristics were determined by zf-rating each frequency component of the playback output of recorded data or provisional data having the same format as the recorded data. The tape discrimination means can also be achieved by frequency characteristic evaluation or by providing an identification code or shape on the magnetic tape cassette in advance.

Effects of the Invention According to the present invention, it becomes possible to set recording conditions that make the most of the characteristics of a magnetic tape in a magnetic recording/reproducing apparatus. Also, during playback, Rif! You can select the desired signal processing.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a magnetic recording/reproducing apparatus according to the present invention, and FIG. 2 is a block diagram showing the configuration of a conventional digital VTR. 4.16... Rotating cylinder, 5.17... Magnetic head, 6... Rotation control unit, 7... Recording condition setting means,
8... Tape discrimination means, 9... Recording condition determining means,
10... Recording condition input means, 11... Playback optimization means.

Claims (1)

[Claims] In a magnetic recording and reproducing device that records and reproduces data on a magnetic tape using a magnetic head provided on a rotating cylinder controlled by a rotation control unit, when the magnetic head records and reproduces the magnetic tape, data is recorded on the magnetic tape. If not recorded, provisional data is recorded on the magnetic tape and reproduced, or if data is recorded on the magnetic tape, the data is reproduced, the frequency components are evaluated using the data, and the tape discriminating means for determining frequency characteristics of a magnetic tape as a transmission path; recording condition determining means for determining specific recording conditions based on the frequency characteristics of the tape discriminating means; and said specific recording of said recording condition determining means. Based on the input recording conditions input by the recording condition input means for inputting conditions or recording conditions,
recording condition setting means for setting recording conditions of the rotation control section; and reproduction optimization means for selecting optimal reproduction signal processing based on the discrimination result of the tape discrimination means and the recording conditions set by the recording condition setting means. A magnetic recording/reproducing device comprising: