JPS5819780A - Magnetic recorder and reproducer - Google Patents

Abstract

PURPOSE:To display the proper recording level for each frequency band and each type of the tape, by providing a means to switch the set voltage between a BPF and a comparator for every type of the tape at the front stage of a voltage comparator where the detected and rectified voltage of a recording signal input is inputted to. CONSTITUTION:The recording signal applied to an input terminal 1 is fed to a recording head 4 via the amplifiers 2 and 3. The output of the amplifier 2 is applied to an amplifier 5 via a BPF16. The plus input terminal of a voltage comparator 10 is connected to the output of the amplifier 5 via a rectifying diode 6 and also earthed via a capacitor 7. The input terminal of one side of the comparator 10 is connected to a power supply VCC via a resistance R8 and then to the terminals a-d of a tape changeover switch 15 via the resistances R9 and R12-R14. The output of the comparator 10 is fed to a display device, i.e., a light emitting diode. In such way, the recording level can be checked by limiting the high frequency component only. Furthermore the level can be set in accordance with the type of the tape.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording and reproducing device.17. For details, < is related to the recording level display device.

FIG. 1 is a peak indicator circuit diagram showing a conventional recording level display device. In the figure, a signal input from a recording input terminal 1 is amplified by an amplifier 2 and an amplifier 5, rectified by a diode 6 and a capacitor 7, and held at its peak value, and then input to the + side input terminal of a voltage comparator 10. . On the other hand, a DC voltage divided by a resistor 8 and a resistor 9 is supplied to one input terminal of the voltage comparator 1o. Here, when the + side input terminal of the voltage comparator 1o becomes higher i voltage than the one side input terminal, the voltage comparator 1
The output terminal of o becomes a high voltage, and one light emitting diode 11 lights up.

The disadvantage of this conventional method is that the peak value is displayed regardless of the frequency of the input signal, so it tends to saturate on the tape. Also, it is not possible to check the level of high frequencies. Furthermore, the level depends on the type of tape.

The problem lies in the fact that Cheetsuk cannot do it.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic recording and reproducing apparatus that can display the appropriate recording level of a magnetic recording and reproducing apparatus for each frequency band and tape type, and that can check the appropriate recording level of high frequencies for each tape type. It is in.

The present invention provides a bandpass filter before a voltage comparator (level comparator) and means for switching the set voltage of the voltage comparator for each tape type.

The appropriate recording level of a magnetic recording/reproducing device is displayed for each frequency band and tape type, and the appropriate recording level suitable for the tape can be easily obtained.

Embodiments of the present invention will be described below based on the drawings. FIG. 2 is a circuit diagram showing an embodiment of the present invention, in which 1 is a recording input terminal, 2 and 3 are amplifiers, and 4 is a recording head, which together constitute a recording system. 5 is an amplifier, 6.7 is a diode and a capacitor constituting a rectifier circuit, and 10 is a voltage comparator.

It is also grounded via capacitor 7. -f and lI input terminals of comparison v10 are connected to power supply 1 through resistor 8.
1ccjc connected, and multiple resistors 9, 12゜15
, 1/l to terminal a of the tape changeover switch 15.

b, c, and d, respectively. The output terminal of the comparator 10 is grounded via an indicator, such as a light emitting diode (meter). The terminal e of the switch 15 is grounded, and the switch causes the resistors 9, 12 . i5,14
One of them is selected. Resistors 9.12 and 13.14 are used to change the set voltage of the comparator 10 depending on the type of tape. 16 indicates a bandpass filter provided between the W reading point of the amplifier 2.3 and the input of the amplifier 5, and the filter +:
t, has the characteristics shown in Figure 4. .

FIG. 3 is a characteristic diagram showing the recording and reproducing characteristics of tape types such as typical TR, normal tape, and metal tape.

As you can see from the characteristic diagram, -20VNt is normal,
The high frequency characteristics are almost the same as metal tape.

However, the higher the level, the more noticeable the drop in the level of high frequencies on normal tape. With current tape decks, it is normally recommended to set the recording/playback level on the level meter near OFu, but since the meter itself displays the entire band, it is difficult to record music with a lot of high frequency components on normal tape. If you do so, you will not be able to record with the same frequency characteristics as the input source. For the above reasons, a filter with the characteristics shown in Figure 4 was provided.

By issuing a saturation level warning for each frequency band, optimal recording and playback characteristics can be obtained.

In such a configuration, the basic operation is the same as that of the prior art shown in FIG.
Since the frequency components for lighting can be limited, level checking can be performed by limiting only the high frequency components that tend to be saturated on the tape. Further, since the voltage set on the negative side of the voltage comparator 10° can be varied by switching the tape changeover switch 15, it is possible to set a level corresponding to the type of tape. According to the present invention, it is possible to optimize the high frequency recording level for each type of tape.

FIG. 5 shows an embodiment in which a plurality of filters, comparators, 9 indicators, etc. are provided.

16f2 is a low pass filter (4Hz), 16
b is a band pass filter (4 to IQXRz), 1
6ty is bypass fiyvri (1(lK#z), 5a,
5h and 5c are amplifiers.

6a, 6h, 6c rectifier diode, 7a
, 7b, 7c are Conde 7-1-110 (Z, I
Qb, 10c is a comparator, 11σ.

11+6, 117? indicates a light emitting diode, and its operation y is the same as described above, so its description will be omitted.

As can be seen from the above, the present invention has the effect of being able to check the appropriate recording level of high frequencies for each type of tape.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a conventional example, FIG. 2 is a circuit diagram showing an embodiment of the present invention, FIG. 5 is a characteristic diagram for explaining the present invention, and FIG. 4 is a diagram of a bandpass filter of the present invention. Characteristic diagram, 5th
The figure is a circuit diagram showing another embodiment of the present invention. 1: Recording input terminal 2 I amplifier 5 Amplifier 4: Recording head 5 I amplifier 6: Diode 7; Capacitor 8 I Resistor 9 E 2 diagram

Claims (1)

[Claims] t. In a magnetic recording and reproducing device, a voltage comparator that detects and rectifies a recording signal input and compares the rectified voltage with a reference voltage;
a band that is coupled to the output stage of the comparator and includes an indicator that displays the input level of the recording signal, and busses a band in which a high frequency component of the recording signal input is present on the input stage side of the comparator; a pass filter is provided, - a voltage setting circuit for setting the reference voltage is provided on the other input stage side of the comparator;
A magnetic recording and reproducing device is characterized in that it enables checking of an appropriate recording level. 2. The above filter! 2. The magnetic recording and reproducing apparatus according to claim 1, wherein a plurality of pressure comparators and indicators are provided for each frequency band. 6. The magnetic recording and reproducing apparatus according to claim 1 or 2, wherein the setting voltage circuit of the voltage comparator is configured to be switched externally depending on the type of tape used.