JPS599616U

JPS599616U - Distortion reduction circuit for frequency modulated wave signals

Info

Publication number: JPS599616U
Application number: JP10391782U
Authority: JP
Inventors: 勲増田; 西川　和典; 岩崎　善樹; 昭治植野; 古村　誠
Original assignee: 日本ビクター株式会社
Priority date: 1982-07-09
Filing date: 1982-07-09
Publication date: 1984-01-21
Also published as: JPH0325344Y2

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of the drawing]

第１図Ａ−Ｅは夫々変調信号と歪の無いときの周波数変
調信号及びそのＦＭ復調出力信号と歪の　　・あるとき
の周波数変調波信号及びそのＦＭ復調出力信号との夫々
波形の一例を示す図、第２図は本考案回路を本出願人が
先に提亭した情報信号記録円盤再生装置に適用したとき
の一実施例を示すブロック系統図、第３図は本考案回路
の一実施例を示す回路図、第４図Ａ〜Ｄは夫々第３図図
示回路の動作説明用信号波形図である。１・・・情報信号記録円盤（ディスク）、２・・・再生
針、９・・・ピックアップ回路、１１０・・・歪低減回
路、１゛２・・・リミッタ、１３・・・ＦＭ復調回路、
１４・・・復調信号出力端子、１５・・・周波数変調波
信号入力端子、１６・・・矩形波出力端子、Ｑｌ・・・
増幅用ＮＰＮ　トランジスタ、Ｒ１，Ｒ２・・・ベース
バイアス用抵抗、ＶＲ・・・ベースバイアス用可変イン
ピーダンス素子、Ｒ５，Ｒ６・・・積分回路用抵抗、Ｃ
４・・・積分用コンデンサ。Figures 1A to 1E show examples of the waveforms of a modulated signal, a frequency modulated signal when there is no distortion, an FM demodulated output signal thereof, a frequency modulated wave signal when there is distortion, and an FM demodulated output signal, respectively. 2 is a block system diagram showing an embodiment of the circuit of the present invention applied to an information signal recording disk reproducing device previously proposed by the applicant, and FIG. 3 is an embodiment of the circuit of the present invention. FIGS. 4A to 4D are signal waveform diagrams for explaining the operation of the circuit shown in FIG. 3, respectively. DESCRIPTION OF SYMBOLS 1... Information signal recording disk (disc), 2... Reproduction needle, 9... Pick-up circuit, 110... Distortion reduction circuit, 1゛2... Limiter, 13... FM demodulation circuit,
14... Demodulated signal output terminal, 15... Frequency modulated wave signal input terminal, 16... Rectangular wave output terminal, Ql...
NPN transistor for amplification, R1, R2... Resistor for base bias, VR... Variable impedance element for base bias, R5, R6... Resistor for integration circuit, C
4... Integrating capacitor.

Claims

[Scope of utility model registration request]

(1) an amplifier having a variable bias circuit and supplied with a frequency modulated wave signal; a limiter converting the output signal of the amplifier into a rectangular wave and outputting the rectangular wave to an FM demodulation circuit;
control means for variably controlling a variable bias circuit of the amplifier to operate the amplifier in a nonlinear region having input/output characteristics that cancel out the distortion when the frequency modulated wave signal includes distortion; A frequency modulated wave signal distortion reduction circuit configured to extract a frequency modulated wave signal with reduced distortion from the amplifier.

(2) The control means integrates the output rectangular wave of the limiter to obtain an average DC level of the rectangular wave, and controls the amplifier in the non-linear region by changing the average DC level with respect to a predetermined constant value. The distortion reduction circuit for a frequency modulated wave signal according to claim 1, which is an integrating circuit that controls the variable bias circuit to operate.

(3) The frequency modulated wave signal is a recording circle of a constant angular velocity method,
It is a frequency modulated wave signal reproduced from a disc, and the control means causes the amplifier to operate in the non-linear region when the reproduction track of recording is a track on the inner circumferential side of a predetermined constant diameter value. A distortion reduction circuit for a frequency modulated wave signal according to claim 1, which is means for controlling the variable bias circuit in such a manner that the frequency modulated wave signal is a means for controlling the variable bias circuit.