JPS6230233Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording level display circuit that makes it easy to know the optimum recording level.

Conventionally, in tape recorders and the like, recording levels have been set using VU meters and peak level meters, but these have not always been easy to use. Therefore, the present invention has been devised to specifically indicate the deviation from the optimum recording level with numerical values.

Conventionally, as a device for adjusting the recording level, for example, Japanese Patent Application Laid-Open No. 53-77606 (G11B5/033)
Devices such as those described in are known.

In such a conventional device, a tone signal from an oscillator is once recorded on a tape, the level of this reproduced signal is compared with the level of the tone signal itself, and adjustments are made by looking at a meter pointer.

For this reason, a tone signal oscillator had to be prepared to adjust the recording level, and the tone signal had to be recorded once on the tape, making the recording level check operation extremely time-consuming.

However, the present invention is constructed so that the level of the recording signal can be checked without recording it on a tape, and an embodiment of the present invention shown in the drawings will be described below.

In the figure, 1 is a recording signal input terminal, 2 is a preamplifier, 3 is a variable resistor for setting the recording level, 4 is a main amplifier, 5 is a recording magnetic head, 6 is a recording amplifier, 7 is a meter drive circuit, 8 is a recording level meter. The above configuration is the same as the conventional one. In the present invention, the following circuit is further added. 9 is an A-D converter, 10 is a maximum value detection circuit that detects the highest value (for example, peak value) of the recording signal, 11 is a discrimination circuit that determines whether the difference is positive or negative with respect to a preset reference value, and 12 is a preset value. 13 is a first display drive circuit; 14 is a second display drive circuit; 15 is a first display drive circuit;
16 is a second display, 17 is a reset means, and 18 is a reset switch. The reference value is set to the maximum value (value corresponding to the optimum recording level) at which the signal can be recorded without distortion, taking into account the characteristics of the tape recorder, the characteristics of the magnetic tape, etc. Further, the positive and negative indications on the first display 15 are not limited to "+, -" but also include arrow indications as shown in the figure. Further, the maximum value detection circuit 10, the discrimination circuit 11, and the arithmetic circuit 12 may be configured by a microprocessor. It is convenient to provide the first display 15 and the second display 16 near the operating knob 19 of the variable resistor 3 for setting the recording level (see FIG. 2).

Now, suppose that the variable resistor 3 for setting the recording level is appropriately set and a signal to be recorded is applied to the terminal 1 for a certain period of time. Then, the second display 16 displays the difference from the reference value, and the first display 15 displays the positive and negative values. Therefore, by operating the operating knob 19 of the recording level setting variable resistor 3 in the direction of increasing or decreasing the recording level based on this display, the optimum recording level can be easily set.

It is convenient to use arrows to indicate positive and negative because the direction of the arrows matches the operating direction of the operating knob 19. Further, when the difference is displayed in decibels, it is more convenient to display the scale of the operation knob 19 in decibels as well.

Incidentally, when recording another recording source, by operating the reset switch 18 and driving the reset means 17, the maximum value detection circuit 10, the first,
Reset the second display 15, 16, etc.

As explained above, according to the device of the present invention, it is possible to easily check the optimum recording level compared to the conventional method in which the tone signal from the oscillator is recorded once on a tape and then the level is checked. , is extremely useful.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a recording level display device according to the present invention, and FIG. 2 is a diagram showing a display means and an operation knob. 9...A-D converter, 10...Maximum value detection circuit, 11...Discrimination circuit, 12...Arithmetic circuit, 15
...First display, 16...Second display.

Claims (1)

[Claims for Utility Model Registration] (a) An analog-to-digital conversion circuit that extracts a part of the recording signal supplied to the recording magnetic head and converts it into a digital signal; (c) a maximum value output from the maximum value detection circuit;
an arithmetic circuit that calculates a difference from a reference value corresponding to a preset optimal recording level; (d) a discrimination circuit that determines whether the difference between the highest value and the reference value is positive or negative; and (e) a determination circuit that 1st to display positive and negative output
A recording level comprising: a display; and (f) a second display for displaying the difference output from the arithmetic circuit, and configured to check the level of the recording signal without recording it on tape. Display device.