JPH0444670A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To eliminate noise and to enable the recording and reproducing taking vocals as a leading part to be easily listenable in voice by making a bias circuit of an NR circuit possess an offset function and making linearity characteristics of the NR circuit variable. CONSTITUTION:A signal S1 inputted to an input terminal 1 is logarithmically compressed by the NR circuit at the time of recording. Then, at the time of reproducing, by operating a control circuit connected to the bias circuit of the NR circuit, the bias circuit has some offset, and input and output characteristics of logarithmic elongation is lowered in its output level for such an input as lower than a certain set level and the signal is reproduced. That is, by adjusting a current IX to flow via RX into a negative power source at the time of reproducing, a variable point of the linearity characteristics can be settled. By this method, noise, such as motor noise and wind whiz to be recorded is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention particularly relates to magnetic recording and reproducing devices such as VTRs and tape decks.

2. Description of the Related Art In recent years, with the spread of camera-integrated VTRs (hereinafter referred to as "movies"), movie playback functions have been attracting attention. −
This will be explained below with reference to the drawings.

A conventional example is shown in FIG. In FIG. 4, a signal S1 input to an input terminal 1 is logarithmically compressed and recorded by an NR circuit during recording. And when playing back, it is NR as it is.
It is logarithmically expanded and reproduced by the circuit. Figure 5 shows the human ability characteristics of the NR circuit.

Problems that the invention aims to solveHowever, with the above configuration, when playing back a tape recorded with a movie, it is easy to record the motor noise and wind noise that are characteristic of movies, so it is difficult to record vocals without vocals. In the small signal portion, the ode to the fact that these noises were noticeable and difficult to hear was highlighted.

In view of the above-mentioned problems, the present invention provides a piezo offset I-circuit that changes the linearity characteristic of the NR circuit and a control circuit that controls the operation of the offset circuit. It is an object of the present invention to provide a magnetic recording and reproducing device that eliminates cutting noise and makes it easier to hear vocals.

Means for Solving the Problems In order to solve the above problems, the present invention provides an NR circuit that logarithmically compresses a signal input from an input terminal during recording and logarithmically expands it during playback, and changes the linearity characteristics of the NR circuit. , a bias offset circuit, and a control circuit that controls the operation of the offset circuit.

Function The present invention removes noise such as motor noise and wind noise in movies by changing the linearity characteristics of the NR circuit during recording and/or playback, and improves the quality of voices, mainly vocals. This enables easy-to-listen recording and playback.

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

In FIG. 1, the signal S1 input to the input terminal 1 is
The NR circuit performs logarithmic compression during recording. During playback, the control circuit connected to the bias circuit of the NR circuit operates, so that the bias circuit has some offset, and the input/output characteristics of logarithmic expansion are at a certain setting level, as shown in Figure 2. With the following inputs, the output level is reduced and the signal is reproduced.

FIG. 3 shows a specific example of a control circuit for providing an offset to the bias circuit. In Figure 3, R during playback
By adjusting the current flowing into the negative power supply through the capacitor, the point at which the linearity characteristic changes in Figure 2 can be set.

Effects of the Invention As described above, according to the present invention, the bias circuit of the NR circuit has an offset function and the linearity characteristics of the NR circuit are varied, thereby reducing noise such as motor noise and wind noise recorded in movies. It is possible to obtain excellent effects such as removing the sound and making it possible to record and play back voices with a focus on vocals that are easy to hear.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a magnetic recording/reproducing device according to an embodiment of the present invention, Fig. 2 is a linearity characteristic diagram of an NR circuit showing the effect of the embodiment, and Fig. 3 is a concrete diagram of the control circuit of Fig. 1. FIG. 4 is a block diagram of a conventional example, and FIG. 5 is a linearity characteristic diagram of a conventional NR circuit. 1...Input terminal, 2...NR circuit, 3
...control circuit. Name of agent: Patent attorney Shigetaka Awano and 1 other carvings? Figure 2

Claims (1)

[Claims] an input terminal, a noise reduction circuit (hereinafter abbreviated as NR circuit) that logarithmically compresses a signal input to the input terminal during recording and logarithmically expands it during playback; a bias offset circuit that changes the linearity characteristic of the NR circuit; A magnetic recording and reproducing device comprising: a control circuit that controls the operation of an offset circuit.