JPH0329108A - Rotary four-head type magnetic tape reproducing device - Google Patents

Abstract

PURPOSE:To improve the quality of reproduced data, an error rate and the traveling speed of a magnetic tape at the time of searching by utilizing all reproduced signals obtained from four magnetic heads at the time of reproducing. CONSTITUTION:All the reproduced signals obtained from the four magnetic heads 2 to 5 are utilized at the time of reproducing. The magnetic heads 2 to 4 are fixed to a drum 10 to be rotated in the arrow 9 direction with equal intervals of 90 deg. in the peripheral direction. A magnetic tape is wound around the outer periphery of the drum 10 by 90 deg. in the peripheral direction, and at the time of recording data are recorded so that the peripheral speed of the drum 10 goes a previously determined value and an azimuth angle goes a previ ously determined value. When data having less errors among data read out from the same recording area are selected, the error rate can be improved, the quality of reproduced data can be improved and the traveling speed of a magnetic tape at the time of searching can also be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotary four-head magnetic tape reproducing apparatus that can be suitably implemented in a digital audio tape (DAT) used as a data memory. 2. Description of the Related Art Conventionally, in a device for recording and reproducing a magnetic tape using a rotary 4-head system having a rotating drum on which four magnetic heads are attached in the circumferential direction, when recording on a magnetic tape, two The remaining two magnetic heads are used to read and confirm the recorded contents, making a total of four magnetic heads. Only the magnetic head is being used, and the remaining two magnetic heads are idle, so to speak. Therefore, it is desirable to improve the quality during playback by utilizing the two magnetic heads that are idle during playback. Problems to be Solved by the Invention An object of the present invention is to provide a rotating four-head type magnetic tape reproducing apparatus that can improve the quality during reproduction. Means for Solving the Problems The present invention provides a rotating four-head type magnetic tape reproducing apparatus having a rotating drum having four magnetic heads arranged in the circumferential direction. This is a rotating four-head type magnetic tape playback device that is specially designed to playback using both. Function According to the present invention, all of the reproduction signals from the four magnetic nodules are used during reproduction, so that the pair of magnetic heads 1, which are arranged 90 degrees apart in the circumferential direction of the drum, is used. The data recorded on the magnetic tape can be read twice for each pair using the magnetic tape. As a result, it is possible to improve the error rate and the quality of reproduced data by selecting the data with fewer errors among the data read from the same recording area j3i. In addition, by running the magnetic tape at a high speed and reading the reproduced signals from each magnetic head, it is possible to improve the accuracy of the search, and also to improve the running speed of the magnetic tape during the search. It is possible to Embodiment FIG. 1 is a block diagram of an embodiment of the present invention. Four magnetic heads 2, 3, 4.5 are provided, and using these four magnetic heads 2 to 5, data from the recording data signal generation circuit 6 is transferred to the magnetic tape 44Ctlt.
The signals recorded on the magnetic tape or reproduced on the magnetic tape can be visually displayed by driving the display means 8 such as a cathode ray tube by the drive circuit 7. The data signal to be recorded on the magnetic tape, for example, may be a binary signal used in a computer or the like, or may also be a video signal. head 2
It is a plan view showing ~5. These magnetic heads 2 to 5 are housed in a drum 1o that is rotated in the direction of arrow 9 at equal intervals of 90 degrees in the circumferential direction. A magnetic tape is wound 90 degrees around the drum 1o, and during recording, data is recorded so that the circumferential speed of the drum 1o becomes a predetermined value and the azimuth angle becomes a predetermined value. The pair of magnetic heads 2 and 3 are offset by 180 degrees in the circumferential direction of the drum 1o, and the pair of magnetic heads 45 are offset by 180 degrees in the circumferential direction of the drum 10.

Data WA, using magnetic head 2.3 on the magnetic tape.
WB is written, and the magnetic heads 4 and 5 read out the `gnA and RB recorded on the magnetic tag, and as shown in FIG. During one rotation of to, 90
The so-called read-after-write (Re
Recording is performed using the aJ AfterWriLe) method. Here, the written content WA of the magnetic head 2 and the magnetic head 4
The reproduced read data RA is the same record on the magnetic tape.
Corresponds to the area. Further, the write data WD by the magnetic head 3 and the reproduction read data RD by the magnetic head 5 are performed in the same recording head area of the magnetic tape. Referring to FIG. 1, the data signal from the recording data signal generation circuit 6 is subjected to arithmetic processing for recording in the recording processing circuit 12, and the data signal is divided into two parts to the amplifier circuits 13 and 14. , and is applied to individual contacts 15a and 16a of changeover switches 15 and 16, respectively. Changeover switch 15. Signals to be recorded from common contacts 15c and 16c of l6 are applied to magnetic henodes 2 and 3 via rotary transformers 17 and 18. During this recording, the data written on the magnetic tape by the magnetic heads 2 and 3 is successively output from the magnetic head 4.5, is amplified by the amplifier circuit 2122 via the rotary trasses 19 and 20, and is subjected to reproduction No. 13 processing. Memory 25. equipped in circuit 23.24.
26. The contents stored in this memory 25.26 are the individual contacts 27a, 28 of the switching switch 27.28.
Through a, their common contact point. 27c and 28c are generated by the data synthesis circuit 31 via lines 29 and 30, and supplied to the drive circuit 7. The rgA dynamic circuit 7 receives data from the signal control circuit 31, and when the data signal is a video signal, drives the cathode ray tube 8 to produce a visual display. During reproduction, reproduction signals RA 1 , RB I RA2, RB2 from a total of four magnetic heads 2.3, 4.5 attached to the drum 10 as shown in FIG.
Both are used for playback. As shown in FIG. 5, during this reproduction, the reproduction signals RAI and RA2 of the magnetic head 2.4 read the same recording chain area of the magnetic tape during each 90 degree period of one rotation period of the drum 10. 13, reproduction signals RBI, RB2 of magnetic nodes 3 and 5
reproduces the same recording head area of the magnetic tape.

During this playback, the first [2l] records, and the playback control circuit 33 connects the common contact 15c of the changeover switch 15.16,
Switch 16c to song-specific contacts 15b and 16b. As a result, the data reproduced by the magnetic head 2.3 is transferred from the rotary transformer 17.18 to the changeover switch 15.16.
are amplified in amplifier circuits 35 and 36,
It is stored in the memory 37.38 of the reproduced signal processing circuit 23.24, and is also provided to the data check circuit 39.40.

During reproduction, the data reproduced by the magnetic heads 4 and 5 is transferred from the rotary transformer 19, 20 to the amplifier circuit 21.
．． 22, amplified and stored in memories 25 and 26, respectively, and data check circuits 39 and 39.
Give to 40. It will be done. The data check circuit 39 selects the contents of the memory 37.25 in which the data with fewer errors is stored when reading the same recording area of the reproduced data given from the amplifier circuit 35.21, The common contact 27c is switched to the separate contact 27b or 27a, and the data signal with the lower error rate is thus led to the line 29. Similarly, in response to the reproduced data signal from the amplifier circuit 36.22, the data check circuit 40 selects the one with fewer errors among the reproduced data signals of the same recording area, and selects the one with fewer errors from among the reproduced data signals of the same recording area. Switch 28c to contact 28b or 28a and lead out to line 30. Synthesizing circuit 31 is line 2
9,. 30 is synthesized, and a display means 8 is driven by a drive circuit 7 to perform display. During such normal playback, the running speed of the magnetic tape is, for example, 8.15 mm/sec, and the magnetic heads 2 to 5
The recorded contents of one recording area 42 are reproduced using the magnetic head 2.4 to produce a reproduced data signal RA1. ,RA
Get 2. Further, the recorded contents of the adjacent recording area 43 are reproduced using the magnetic heads 3 and 5, and reproduced data signals RBI,
Get RB 2. Reproduction is performed by repeating these operations. The magnetic tag is indicated by the reference numeral 44, and the running direction of the magnetic tape on the outer peripheral surface of the rotating drum 10 is indicated by the reference numeral 45.
As shown in When searching for contents recorded on a magnetic tape, the above-mentioned 6th
Similarly to the reproduction described in connection with the figure, when performing fast forward running FF in the tape running direction 45, the magnetic heads 2 to 5
can be used to reproduce and read data from the magnetic tape 44, improving search accuracy. In the above-mentioned prior art, only the reproduced data signal from the magnetic node 2.3 shown by the solid line in No. 7I2l can be obtained, and therefore the search accuracy is low. The present invention solves this problem. Referring to FIG. 8, the magnetic tape 44 is
Rotating drum 1 in the running direction 46 opposite to the running direction shown in the figure.
Even when running on the outer peripheral surface of 0 and performing a reproduction REW search with the running speed set to a high speed, if the sweat rate is the same as before, the running speed of the tape can be improved, and therefore the search speed can be improved. It is possible to aim for The aforementioned seventh
During the so-called FF search shown in the figure and the so-called REW search shown in FIG. It is possible to speed up such searches. The present invention can be implemented not only for reproducing binary data in computers, etc., but also for reproducing video signals, and furthermore, for reproducing other data. Effects of the Invention As described above, according to the present invention, in a magnetic tape playback device using four rotating heads, all of the playback signals from each of the four magnetic heads are used during playback, so that the quality of playback data can be improved. For example, it is possible to improve the error rate, improve search accuracy,
Furthermore, it becomes possible to improve the running speed of the magnetic tape during search.

[Brief explanation of drawings]

1 is a block diagram showing the overall configuration of an embodiment of the present invention, FIG. 2 is a plan view of the rotating drum 10 showing the state during recording, and 311 is a recording operation in the recording process shown in FIG. 2. Figure 4 is a diagram for explaining the rotating drum 1 during playback.
0, No. 511Z is a diagram for explaining the operation during reproduction, FIG. 6 is a diagram showing the reproducing path of the magnetic heads 2 to 5 when reproducing and reading the magnetic tape 44, and No.
The figure shows the reproduction path when the magnetic tape 4 is reproduced using the magnetic heads 2 to 5 during a so-called FF search, and FIG. 8 shows the reproduction path when the magnetic tape 4 is reproduced using the magnetic heads 2 to 5 during a so-called REW search. FIG. 1...Rotating drum, 2-5...
・Magnetic head, 6... Recording data signal generation circuit, 7
... Drive circuit, 8... Display means, 12... Recording processing circuit, 13, 14, 21, 22, 35, 36...
Amplifier circuit, 15, 16, 27, 28... Selector switch, 17-20... Rotary transformer, 23.24.
...Reproduction signal processing circuit, 25.26.37.38...
Memory, 31... Self-adjudication circuit, 39, 40... Data check circuit

Claims (1)

[Scope of Claims] In a rotating four-head type magnetic tape reproducing device having a rotating drum having four magnetic heads attached in the circumferential direction, all of the reproduction signals from each of the four magnetic heads are used to perform reproduction. A rotary four-head type magnetic tape reproducing device characterized by: