JPS6012394Y2 - FM playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an FM reproducing device, and particularly to one in which a de-emphasis characteristic is obtained by providing an integral action at an output section including an electrostatic speaker.

Generally, in an audio reproduction apparatus, signals are operated in a so-called amplitude form throughout the system, as shown in FIG. 1, which shows a disk record reproduction system as a typical example.

That is, this obtains a signal converted into an amplitude component by a cartridge 11 such as an electrostatic type, and directly transmits this signal to a preamplifier 12, an equalizer circuit 13, and a main amplifier 14.
The signal is supplied to an electromagnetic speaker 15, such as a moving coil type speaker, through the antenna to obtain acoustic (reproduction) output.

However, in systems such as this, where all signals are handled as amplitude-type signals, the inherent nature of the system is that it is easily affected by time-component signals such as distortion and noise components generated within the amplifiers of the signal transmission system. It has certain deficiencies.

In addition, recently, electrostatic speakers have been developed as speakers that are excellent in reproducing high-frequency sounds, but an electrostatic speaker can be used as is in place of the electromagnetic speaker 15 in the reproduction system shown in Figure 1. If so, the amplifier 14 is likely to be destroyed because the impedance decreases too much in the high frequency range, and if a protective resistor is inserted to prevent this, the high frequency reproduction characteristics that are characteristic of electrostatic speakers will deteriorate. It had the disadvantage of being damaged.

On the other hand, in the case of an FM reproducing device, a dedicated circuit is required in order to provide a de-emphasis characteristic to an FM signal that is received with a pre-emphasis characteristic that increases the high frequency range.

Therefore, this idea was made in view of the above points, and it is possible to improve the de-emphasis characteristic by adding an integral action to the FM signal having the pre-emphasis characteristic at the output section including the electrostatic speaker. An FM playback device that can be obtained without using any dedicated circuit, and that can reduce the influence of the signal on time components as much as possible by treating frequencies above a certain level as speed types. is intended to provide.

An embodiment of this invention will be described below with reference to FIGS. 2 and 3.

That is, FIG. 2 shows an embodiment of the FM reproducing device according to this invention, which has a pre-emphasis characteristic (50 pSeC-o in Japan) given to the FM signal.
f (t) Medium 3.18kHz, 3dB, 75 in Europe and America
μ5e(-”f(t)”2-12kHz293d
B) As shown in Figure 3, by using the frequency characteristic that the gain is constant up to f and increases above a certain frequency such as +5dB10ct, f and below are amplitude types, and above It is speed. The purpose of this project is to provide an FM playback device that can be used as a model.

That is, the FM signal obtained through the tuner 30 is directly amplified by the audio amplifier 236 without being de-emphasized after detection, and then is distributed to the electromagnetic speaker 248 and the electrostatic speaker 249. However, on the electrostatic speaker 249 side, the (constant) resistance R and the capacitance C of the speaker itself cause an integral action over f, so that it is essentially a speed-type signal. The signal above f is converted back into an amplitude signal and reproduced, and in this case, of course, the signal below f is reproduced on the electromagnetic speaker 248 side as before.

According to such an FM playback device, as will be described later, the effect of a sound playback system that uses one amplifier in common and separately reproduces low-mid range and high-range range, can be reproduced as FM. This can be achieved specifically in playback systems.

In other words, in order to suppress the treble region and make the overall frequency response as flat as possible, an integral action is involved in the treble region, and as a result, the so-called de-emphasis characteristic is not used exclusively. This can be obtained without using any circuit.

This reduces the leakage of unnecessary frequency waves as much as possible, prevents deterioration of reproduced sound quality, and protects the amplifier, electrostatic speaker, etc. themselves.

By the way, in the above, if large amplitude components at low frequencies are re-corrected at the same time, non-linear distortion will occur in the amplification element etc. due to saturation by the large amplitude components, but generally the (voltage) amplitude spectrum at high frequencies is very small, so this does not cause saturation.

In other words, in the above-mentioned FM playback device, the level for each frequency range of the general sound field reproduction is very small in the high frequency range.In other words, it is not necessary to have sound pressure, but to have a balance commensurate with each range as a level. This is a case in which a single amplifier is shared, and a low-mid range reproduction system and a high-frequency range reproduction system are respectively used exclusively for reproduction.

In addition, in the case of 10 or more, which is treated as a velocity type, there is no effect on the time component, and the S/N and distortion rate improvements of the entire system are extremely remarkable, and the dynamic range of the amplifier itself is expanded to make effective use of it. It becomes possible to increase the rate.

Therefore, as described in detail above, according to this invention, the de-emphasis characteristic can be improved by performing an integral action on the FM signal having the pre-emphasis characteristic at the output section including the electrostatic speaker. It is possible to provide an FM reproducing device that can obtain the FM signal without using a frequency component, and can reduce the influence of the signal regarding the time component as much as possible by treating frequencies substantially above a certain level as velocity types. Become.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing a typical conventional sound reproduction device, Fig. 2 is a circuit diagram showing an embodiment of the FM reproduction device according to this invention, and Fig. 3 explains the operation of Fig. 2. FIG. 3 is a curve diagram showing a pre-emphasis characteristic in an FM signal for the purpose of providing an FM signal. 30...Tuner, 236...Amplifier, 249...Capacitive speaker, 248...
...Electromagnetic speaker.

Claims (1)

[Scope of utility model registration request] A tuner that derives an FM signal having a pre-emphasis characteristic that is flat up to a predetermined frequency f and rises at a predetermined slope above 10; an amplifier that directly amplifies the FM signal from the tuner; comprising an electromagnetic speaker for reproducing low and midrange frequencies directly connected to the output end of the amplifier, and an electrostatic speaker for reproducing high frequency ranges connected to the output end of the amplifier via a resistive component, The FM playback is characterized in that the resistance component and the capacitance component of the electrostatic speaker are integrated so as to fall at a predetermined slope above the ft, thereby obtaining a de-emphasis characteristic. Device.