JPH03144987A - Level display method of rotary head type digital audio tape recorder - Google Patents

Abstract

PURPOSE:To put a level meter in equal-speed motion without any influence upon a recording mode by varying the counted value of level data in the recording mode. CONSTITUTION:The level data of an audio signal which is recorded in the recording mode through a digital signal processing circuit 12 are counted by a display microcomputer 34 up to a specific number, a level meter 36 indicates the maximum value of a specific number of level data when the maximum value is larger than a last display or display the last displaying data on the level data 36 when smaller, and the same operation is repeated. The specific number is varied according to different-speed recording modes such as an LP and a standard mode, and consequently the level meter is put in the equal-speed motion without any influence upon the recording mode, so that its level is displayed in an easy-to-see state.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a rotary head type digital audio recorder (hereinafter referred to as R-DAT), and particularly to a level display method thereof.

(b) Prior Art Below, a conventional R-DAT block is shown in FIG. 3 and explained. In the figure, (1) is an input terminal into which analog audio signals, etc. are input, (2) is a digital signal circuit that performs interleaving and time axis compression on the audio signal and converts it into digital, and (3) is for tracking control. (4) is a subcode signal generation circuit that generates subcode signals such as star) ID, track number, and playing time information for high-speed search; (5) is a subcode signal generation circuit that generates an ATF signal for tape. A PCM area formed in each track, AT
A switch circuit that selects and switches a predetermined signal to the F area and subcode area at a predetermined timing, (6> is a recording amplifier, and (7) is a switch circuit that connects the output from the recording amplifier (6) to two recorders 180° apart. The rotary transformer of the cylinder (9) to the rotation supplied to the reusable magnetic head (8) (8), (
9a) is a cylinder motor, (10) is a regeneration amplifier, (
1]) is a PCM demodulation circuit that converts the digital audio signal from the reproduction amplifier (10) into an analog signal, (12) is a digital signal processing circuit that processes the subcode etc. from the reproduction amplifier (10), and (13) (14) is a servo circuit that extracts the ATF signal from the reproduction amplifier (10) and generates a tracking error signal for tracking control;
is the magnetic tape, (15) is the capstan, (16) is the capstan motor, (17) is the capstan motor drive circuit, and (18) is the capstan (15) etc. depending on the subcode and various keys. Control circuit for controlling (19)
is an output terminal from which audio is output.

Therefore, during recording, the audio signal input to the input terminal (1) is digitally converted by the PCM modulation circuit (2), and the A
The ATF signal from the TF signal generation circuit (3) and the subcode from the subcode generation circuit (4) are sent to the recording amplifier (6) in a time-sharing manner, and then sent to the magnetic head (8) via the rotary transformer (7). (8') by magnetic tape (1
4) Recorded above. At this time, a track pattern as shown in FIG. 1 is formed on the tape, and a PCM area (31) is formed in the center of each track, and ATF areas (32) (32) are formed on both sides of the PCM area (31). 'I' F f
Subcode area (33) outside l area (32) (32)
(33) will be JjJ.

Next, during playback, the audio signal, ATF signal, and subcode signal recorded on the magnetic tape (14) are transferred to the magnetic head (8) (
8) and sent from the rotary transformer (7) to the reproduction amplifier (10), the audio signal is demodulated by the PCM modulation circuit (11), the audio is output from the output terminal (19), and the subcode signal is Sub code place 8! Circuit (1
2), the ATF signal is processed to display time information, etc., and the ATF signal is used to generate a tracking error signal in a servo circuit (13), which controls a capstan (15) to perform tracking control.

The recording method of the R-DAT device includes a normal recording mode (hereinafter referred to as SP mode) and a long-time recording mode (hereinafter referred to as LP mode) that allows recording for twice the time of this SP mode. The level display in the above two recording modes is performed by counting the number of input digital data, comparing the levels each time the number of data reaches a predetermined number, and holding the maximum value for a certain period of time. , I was trying to display the level of that data.

Regarding the level display method of a digital device, there is a method disclosed in Japanese Patent Application Laid-Open No. 62-231486 (G11B27/36).

(c) Problem to be Solved by the Invention The data input to the level meter drive circuit of R-DAT is inputted with 1 omitted from the cylinder rotation synchronization clock,
In P mode recording, the cylinder rotation speed is 2000 rpm.
So, in the I and P mode recordings, the cylinder rotation speed was 11.
000 rp, the time required to count the predetermined number of data is different in the above two modes. That is, since it takes twice as much time to record in the LP mode as it does to record in the SP mode, the movement of the level meter becomes slow during recording in the LP mode, which has the drawback of being very unsightly in practice.

(d) Means for Solving the Problems The present invention is intended to solve the above problems, and provides an audio signal digitally converted by a rotating head,
R-1 records an ATF signal for traffking control and a subcode signal such as time information on the same track of a magnetic tape, and reproduces the subcode signal along with the audio signal.
In the DAT, the level data of the audio signal input corresponding to the rotational speed of the cylinder is inputted in a predetermined number of runs).

When displaying the maximum level data among the predetermined number of data, it recognizes whether it is an SP mode record or an LP mode record, and changes the predetermined number of data count values according to the mode. We propose an R-DAT level display method characterized by the following.

(E) Effect According to the above means, the R-DAT recording mode (SP
Since the count value of the input level data is changed depending on the recording mode (LP mode, LP mode), the level meter can be moved at the same speed regardless of the recording mode.

(F) Embodiment Next, the level display method of the present invention will be explained with reference to the flowchart of FIG. 1 and the block diagram of FIG. 2.

In Fig. 2, (36) is a level meter that displays the signal level, (35) is a drive circuit that fully drives the level meter (36), and (34) is a rotation synchronized clock and digital signal of cylinder (9). The display microcomputer receives level data from the processing circuit (2) and always recognizes the recording mode of the recording mode changeover switch (37).

First, if it is determined in step 1 that it is in the recording state, in step 2 it is determined whether it is SP mode or LP mode, and
The predetermined number of data to be counted when it is determined that the mode is n
(Step 3), and in Step 5, the count value N of the level data from the digital signal processing circuit (12) is actually determined.
During the counting, the maximum value in the previous level data is displayed on the level meter (36) (step 6), and 1 is added to the count value N (step 7). , repeat from step 2 until it is determined in step 8 that the system is in a stopped state. On the other hand, when the count value N becomes equal to the count number n in step 5, the new maximum value in the counted level data is displayed (step 9), and the count value is cleared in step l.
O) The operations from step 2 are repeated until it is determined in step 8 that the machine is in a stopped state.

In addition, if it is determined in step 2 that the mode is not SP mode, that is, LP mode, the count number is set to n/2 (step 4
), the above operations are performed to drive the level meter. Since the value is changed, the level meter can move at the same speed regardless of the recording mode, making the level display very easy to see, which is extremely useful in practice.

[Brief explanation of the drawing]

Figure 1 1! A flowchart for explaining the level display method of the present invention, FIG. 2 is a block diagram showing a level meter display circuit, FIG. 3 is a block diagram of a general R-DAT device, and FIG. 4 is a track diagram of R-DAT. It is a figure showing a 7-ohmat. (34)... Display microcomputer, (35)... Level meter drive circuit, (36)... Level meter, (37
)... Recording mode selector switch.

Claims (1)

[Claims] (1) Audio signals digitally converted by a rotating head, ATF signals for tracking control, and subcode signals such as time information are recorded on the same track of a magnetic tape, and the subcode signals are reproduced together with the audio signals. In a rotary head type digital audio tape recorder, when counting a predetermined number of level data of the input audio signal corresponding to the rotation speed of the cylinder, and displaying the maximum level data among the predetermined number of data, the standard A level display method for a rotary head type digital audio tape recorder, characterized in that it recognizes whether it is recording mode or long time mode and changes a predetermined number of data count values depending on the mode. .