CN1073312A - Lost signal compensator - Google Patents

Abstract

Translated fromChinese

本发明在从记录媒体读取或通过传输通道接收的调制信号进行解调的装置中，为了改善信号的复原状态，通过追加ASD功能提供一种可使漏失信号补偿部分的噪音成分最小的漏失信号补偿装置。在ASO器之前配置有用以检测调制信号的漏失部分的漏失信号检测器，从不具有ASO功能的调制信号中检测出漏失的部分后，产生漏失脉冲信号。从而可使在漏失信号补偿部分产生的噪音进一步减少。

The present invention provides a missing signal that minimizes the noise component of the missing signal compensation part by adding an ASD function in an apparatus for demodulating a modulated signal read from a recording medium or received through a transmission channel in order to improve the restoration state of the signal. compensation device. A missing signal detector for detecting the missing part of the modulated signal is arranged before the ASO device, and after detecting the missing part from the modulated signal without ASO function, a missing pulse signal is generated. Thereby, the noise generated in the missing signal compensating section can be further reduced.

Description

Translated fromChinese

本发明涉及一种用以对从记录媒体读取的、或通过传输通道接受的指定的调制信号复原的装置中信号的漏失部分进行补偿的装置，特别是通过追加ASO（Active    Sideband    Optimum有效边带最佳值）功能，而使所引起的漏失信号补偿部分的噪声最小的漏失信号补偿装置。The present invention relates to a device for compensating the missing part of the signal in the device for restoring the specified modulated signal read from the recording medium or received through the transmission channel, especially by adding ASO (Active Sideband Optimum) The best value) function, and the missing signal compensation device that minimizes the noise caused by the missing signal compensation part.

通常，用VCR（盒式磁带录像机）等装置读取记录在规定的记录媒体上的数据并进行复原时，在解调调频信号的过程中，是最大限度地使用调频信号的下边带信号，几乎不用上边带信号。通过在这种先有的VCR上配备ASO功能，能在复原调频信号时使下边带和上边带的信号电平为最佳值。也就是说，具有ASO功能的VCR在复原调频信号时，不仅复原下边带信号，而且也适当地复原上边带信号，提高了图象信号的复原能力，所以，可提供更鲜明的画面。这种先有的VCR，再现从记录媒体读取的数据时会产生漏失信号现象，此漏失信号现象是因为反复播放或损伤使记录媒体上磁化成分出现忽而变弱忽而丢失的部分而造成的。即，在磁化成分减弱或消失的部分，产生再现信号的电平忽而下降忽而消失的现象。用以防止这种漏失信号现象的功能是DOC（Drop    Out    Compensation信号失落补偿）功能。DOC功能是通过检测记录媒体中磁化成分忽弱忽失部分，并将在时间上位于此被检测的信号之前的信号插入以代替漏失的部分来补偿漏失部分的信号。Usually, when the data recorded on a specified recording medium is read and restored by a device such as a VCR (Video Cassette Recorder), in the process of demodulating the FM signal, the lower sideband signal of the FM signal is used to the maximum extent, almost No upper sideband signal. By providing such a conventional VCR with the ASO function, it is possible to optimize the signal levels of the lower sideband and the upper sideband when restoring the FM signal. That is to say, when the VCR with ASO function restores the FM signal, it not only restores the lower sideband signal, but also appropriately restores the upper sideband signal, which improves the restoration ability of the image signal, so it can provide a more vivid picture. This prior VCR, when reproducing the data read from the recording medium, will produce a dropout phenomenon. This dropout phenomenon is caused by repeated playback or damage that causes the magnetization component on the recording medium to appear suddenly weakened and then lost. That is, in the portion where the magnetization component is weakened or disappeared, the level of the reproduced signal suddenly drops and then disappears. The function used to prevent this kind of missing signal phenomenon is the DOC (Drop Out Compensation signal loss compensation) function. The DOC function is to compensate the signal of the missing part by detecting the weak and missing part of the magnetization component in the recording medium, and inserting a signal that is temporally ahead of the detected signal to replace the missing part.

图1示出以往的具有DOC功能的VCR数据再现装置的一个例子。FIG. 1 shows an example of a conventional VCR data reproducing apparatus having a DOC function.

在图1的装置中，用磁头10从记录媒体读取的信号被前置放大器（Pre-amplifier：20）放大为规定大小的信号。均衡器30接收由前置放大器20输出的调频信号，通过修正此信号的被改变的频率特性，可在调频信号解调时，恢复成与原来信号最相近的信号。均衡器30的输出信号供给ASO器40，ASO器40通过对输入的调频信号使其下边带和上边带形成最合适的信号电平从而追加了在调频信号解调时的复原能力。自动增益控制器50能自动调整由ASO部40供给的信号的增益，使信号的大小达到一定的电平。自动增益控制器50的输出信号同时供给限幅器60和漏失信号检测器80。限幅器60不仅对输入的调频信号的下边带而且也对其上边带进行限幅，由于在上边带信号振幅小的时候也用限幅器60检测，从而在解调时数值小的上边带信号也可以复原。这样，经过限幅的调频信号通过解调器70便可复原为原来的图象信号。In the apparatus of FIG. 1 , a signal read from a recording medium by amagnetic head 10 is amplified by a preamplifier (Pre-amplifier: 20 ) to a signal of a predetermined magnitude. Theequalizer 30 receives the FM signal output by thepreamplifier 20, and by correcting the changed frequency characteristics of the signal, it can restore the signal closest to the original signal when the FM signal is demodulated. The output signal of theequalizer 30 is supplied to theASO unit 40, and theASO unit 40 adds the restoration capability in the demodulation of the FM signal by forming the lower sideband and the upper sideband of the input FM signal to an optimum signal level. Theautomatic gain controller 50 can automatically adjust the gain of the signal supplied from theASO unit 40 so that the magnitude of the signal becomes a constant level. The output signal of theautomatic gain controller 50 is supplied to thelimiter 60 and themissing signal detector 80 at the same time. Thelimiter 60 not only limits the lower sideband of the input FM signal but also its upper sideband. Since the amplitude of the upper sideband signal is also detected by thelimiter 60, the upper sideband with a small value during demodulation Signals can also be restored. In this way, the clipped FM signal can be restored to the original image signal by thedemodulator 70 .

另一方面，自动增益控制器50输出的调频信号供给漏失信号检测器80后，便在此调频信号的漏失部分产生具有规定脉冲电平的漏失脉冲信号。于是，将此漏失脉冲信号供给指定的漏失信号补偿器（图中未示出），如上所述该漏失信号补偿器通过用漏失之前的数据值代替检测出的漏失部分的数据值便可防止在漏失部分产生噪声信号。On the other hand, when the frequency modulation signal output from theautomatic gain controller 50 is supplied to themissing signal detector 80, a missing pulse signal having a predetermined pulse level is generated at the missing part of the frequency modulation signal. Then, this missing pulse signal is supplied to a designated missing signal compensator (not shown in the figure), and the missing signal compensator, as described above, can prevent the data value of the detected missing part by replacing the data value before the missing. The dropout portion produces a noise signal.

但是，在这种先有的数据再现装置中，再现的调频信号虽在经过ASO器40使漏失的部分减小的同时，也会使漏失信号检测器80检测的漏失信号脉冲的宽度变小。随着漏失脉冲宽度变小，由于在漏失信号补偿部分因漏失信号引起畸变的区间的宽度增加，所以，在漏失补偿部分产生的噪声也增加。However, in this conventional data reproducing apparatus, although the reproduced FM signal passes through theASO device 40 to reduce the missing portion, the width of the missing signal pulse detected by themissing signal detector 80 is also reduced. As the missing pulse width becomes smaller, since the width of the section where distortion due to the missing signal increases in the missing signal compensating part, the noise generated in the missing compensating part also increases.

因此，本发明的目的是在有ASO功能的数据恢复装置中，提供一种能使因追加ASO功能引起的漏失补偿部分所增加的噪音成分为最小的漏失信号补偿装置。SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a dropout signal compensator capable of minimizing the noise component added to the dropout compensation part due to the addition of the ASO function in a data recovery device having an ASO function.

为了达到上述目的，利用用来解调被调制为指定频率的信号的装置，在用以补偿调制信号的漏失部分的装置中，设有：施加调制信号的输入端、把通过输入端输入的调制信号的下边带和上边带进行最佳化处理并进行复原的ASO器、连接在输入端和ASO器之间用来检测上述调制信号的漏失部分，并产生漏失信号脉冲的漏失信号检测器、和利用由漏失信号检测器供给的漏失信号脉冲来补偿输入信号的漏失部分的漏失信号补偿。In order to achieve the above object, using the device for demodulating the signal modulated to a specified frequency, in the device for compensating the missing part of the modulation signal, there are: an input terminal for applying the modulation signal, a modulation signal input through the input terminal The lower sideband and the upper sideband of the signal are optimized and restored by an ASO device, a missing signal detector connected between the input terminal and the ASO device to detect the missing part of the modulation signal and generate a missing signal pulse, and Missing signal compensation for compensating for a missing portion of an input signal using a missing signal pulse supplied by a missing signal detector.

图1是表示已有的有漏失信号补偿功能的数据再现装置的方框图。FIG. 1 is a block diagram showing a conventional data reproducing apparatus having a missing signal compensation function.

图2是表示本发明的有漏失信号补偿功能的数据再现装置的方框图。10-磁头    20-前置放大器Fig. 2 is a block diagram showing a data reproducing apparatus having a missing signal compensation function according to the present invention. 10-head 20-preamplifier

30-均衡器    40-ASO器30-Equalizer 40-ASO

50，90-自动增益控制器    60-限幅器50, 90-automatic gain controller 60-limiter

70-解调器    80，100-漏失信号检测器70-demodulator 80, 100-missing signal detector

下面，根据附图详细说明本发明的最佳实施例。Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

图2示出按照本发明的有漏失信号补偿装置的VCR数据再现装置。FIG. 2 shows a VCR data reproducing apparatus with a missing signal compensating apparatus according to the present invention.

图2的装置由以下各部分组成：将用磁头从记录媒体读取的数据放大为规定大小的前置放大器20、接受由前置放大器20输出的调频信号并补偿此信号的已改变的频率特性的均衡器30、使均衡器30供给的调频信号的下边带信号和上边带信号能在最佳条件下复原的ASO器40、用以自动调整ASO器40的输出信号的增益的第一自动增益控制器50;对第一自动增益控制器50输出的信号的下边带及上边带进行限幅的限幅器60、把限幅器60输出的调频信号解调为图象信号的解调器70、自动调整由上述均衡器30输出的调频信号的增益，以便把信号的大小维持在一定电平的第二自动增益控制器90、以及用以借助第二自动增益控制器90的输出信号检测漏失信号部分的漏失信号检测器100。The device of Fig. 2 is made up of the following parts: thepreamplifier 20 that amplifies the data read from the recording medium with the magnetic head into a specified size, accepts the frequency modulation signal output by thepreamplifier 20 and compensates the changed frequency characteristic of this signal Theequalizer 30, theASO device 40 that enables the lower sideband signal and the upper sideband signal of the FM signal supplied by theequalizer 30 to be restored under optimal conditions, the first automatic gain for automatically adjusting the gain of the output signal of theASO device 40Controller 50; alimiter 60 for limiting the lower sideband and upper sideband of the signal output by the firstautomatic gain controller 50, and ademodulator 70 for demodulating the frequency modulation signal output by thelimiter 60 into an image signal , automatically adjust the gain of the FM signal output by the above-mentionedequalizer 30, so that the size of the signal is maintained at a secondautomatic gain controller 90 at a certain level, and for detecting leakage by means of the output signal of the secondautomatic gain controller 90Missing Signal Detector 100 of the Signal Section.

在图2的装置中，对和图1装置中相同的方框标以相同的标号，对这些相同的方框不再说明。In the apparatus of FIG. 2, the same blocks as those in the apparatus of FIG. 1 are given the same reference numerals, and description of these same blocks will not be repeated.

在图3A至图3F中示出由图1装置及图2装置的方框输出的信号的波形图。Waveform diagrams of signals output by the blocks of the apparatus of FIG. 1 and the apparatus of FIG. 2 are shown in FIGS. 3A to 3F .

参照图3A至图3F的波形图，说明图2装置进行漏失信号补偿的过程。Referring to the waveform diagrams of FIG. 3A to FIG. 3F , the process of the device in FIG. 2 performing missing signal compensation will be described.

在图2的装置中，由均衡器30输出的调频信号供给第二自动增益控制器90，第二自动增益控制器90自动调整输入的调频信号的增益，使信号的大小达到一定的电平。进行过自动增益控制的调频信号供给漏失信号检测器100，漏失信号检测器100利用输入信号检测出漏失的部分后，产生规定的漏失脉冲信号。于是，被解调器70解调的信号利用由漏失信号检测器100输出的漏失脉冲信号进行漏失信号补偿。In the device of FIG. 2, the FM signal output by theequalizer 30 is supplied to the secondautomatic gain controller 90, and the secondautomatic gain controller 90 automatically adjusts the gain of the input FM signal to make the signal reach a certain level. The frequency modulation signal subjected to automatic gain control is supplied to themissing signal detector 100, and themissing signal detector 100 detects the missing part by using the input signal, and generates a predetermined missing pulse signal. Then, the signal demodulated by thedemodulator 70 is subjected to missing signal compensation using the missing pulse signal output from themissing signal detector 100 .

图3A为由图2的第二自动增益控制器90输出的调频信号的漏失部分，图3B为由图1的自动增益控制器50输出的调频信号的漏失部分，图3C为由图2的漏失信号检测器100产生的漏失信号脉冲，图3D为由图1的漏失信号检测器80产生的漏失信号脉冲，图3E为用图2的装置时漏失信号补偿部分存在的畸变，图3F为用图1的装置时漏失信号补偿部分存在的畸变。Fig. 3 A is the leakage part of the frequency modulation signal output by the secondautomatic gain controller 90 of Fig. 2, Fig. 3B is the leakage part of the frequency modulation signal output by theautomatic gain controller 50 of Fig. 1, Fig. 3C is the leakage part of the frequency modulation signal output by Fig. 2 The missing signal pulse generated by thesignal detector 100, Fig. 3D is the missing signal pulse generated by themissing signal detector 80 of Fig. 1, Fig. 3 E is the distortion existing in the missing signal compensation part when using the device of Fig. 2, Fig. 3F is the 1 means that the missing signal compensates for the distortion that exists in the part.

由图3A和图3B可知，在未追加ASO功能的均衡器30的输出信号（图3A）中，因漏失信号而引起的信号畸变区间为△T₁，在应用ASO功能的ASO器40的输出信号（图3B）中，因漏失而引起的信号畸变区间为△T₂，两者相比，△T₂的宽度更大。因而，由图3C和图3D可知，与未追加ASO功能的漏失信号部分相应的漏失信号脉冲（图3C）的宽度为△T₃，与应用ASO功能的漏失信号部分相应的漏失信号脉冲（图3D）的宽度为△T₄，两者相比，△T₄值比△T₃更小。于是，如图3E和图3F所示，因为用已解调的信号对漏失部分的漏失信号补偿是按照由漏失信号检测器产生的漏失脉冲信号在其脉冲区间实施的，所以便在从因漏失而信号开始畸变的部分到利用漏失信号脉冲开始进行漏失补偿的部分之间产生一定大小的噪音。因此，当漏失信号脉冲的宽度小时（图3D），漏失信号补偿部分产生的噪音大，与此相反，在漏失信号脉冲的宽度大时（图3C），漏失信号补偿部分产生的噪音变小。像图2的装置那样，利用ASO器40的输入信号检测漏失信号时，比利用具有ASO功能的信号检测漏失信号时产生的漏失信号脉冲更宽，因而，在漏失信号补偿部分的畸变区间产生的噪声便减少。It can be seen from Fig. 3A and Fig. 3B that in the output signal of theequalizer 30 without the ASO function (Fig. 3A), the signal distortion interval caused by the missing signal is ΔT₁ , and in the output signal of theASO device 40 with the ASO function In the signal (Fig. 3B), the signal distortion interval caused by the dropout is △T₂ , and the width of △T₂ is wider compared with the two. Therefore, it can be known from Fig. 3C and Fig. 3D that the width of the missing signal pulse (Fig. 3C) corresponding to the part of missing signal without ASO function is △T₃ , and the width of the missing signal pulse corresponding to the part of missing signal with ASO function (Fig. 3D) has a width of △T₄ , comparing the two, the value of △T₄ is smaller than △T₃ . Then, as shown in FIG. 3E and FIG. 3F, because the missing signal compensation of the missing part is implemented in its pulse interval according to the missing pulse signal generated by the missing signal detector with the demodulated signal, so that the On the other hand, a certain amount of noise is generated between the part where the signal starts to be distorted and the part where the loss compensation is started by using the missing signal pulse. Therefore, when the width of the missing signal pulse is small (FIG. 3D), the noise generated by the missing signal compensation part is large. On the contrary, when the width of the missing signal pulse is large (FIG. 3C), the noise generated by the missing signal compensation part becomes small. Like the device in Fig. 2, when using the input signal of theASO device 40 to detect the missing signal, the missing signal pulse generated when using the signal with the ASO function to detect the missing signal is wider, therefore, the distortion interval generated in the missing signal compensation part Noise is reduced.

如上所述，本发明的漏失信号补偿装置，在从记录媒体读取的重现调频信号通过ASO器之前，检测出此调频信号的漏失部分后，通过产生漏失信号脉冲，就能使在漏失信号补偿部分的畸变区间产生的噪声最小。As described above, the missing signal compensating device of the present invention detects the missing portion of the FM signal before the reproduced FM signal read from the recording medium passes through the ASO device, and generates missing signal pulses to make the missing signal The distortion interval of the compensation part produces the least noise.

上述实施例对VCR的数据再现装置应用的漏失信号补偿装置进行了说明，但本发明的漏失信号补偿装置不限于VCR。也就是说，本发明的漏失信号补偿装置，可以广泛应用于在通过规定的调制过程进行调制后，记录到记录媒体上，或通过传输通道，读取发射的信号，并在进行接收、解调的过程中，补偿在处理信号时所产生的漏失现象的装置。The above embodiments have described the missing signal compensating device applied to the VCR data reproducing device, but the missing signal compensating device of the present invention is not limited to the VCR. That is to say, the missing signal compensating device of the present invention can be widely used in recording on a recording medium after being modulated through a prescribed modulation process, or reading the transmitted signal through a transmission channel, and performing reception and demodulation A device that compensates for the dropout phenomenon that occurs during signal processing.

Claims (4)

1, a kind of lost signal compensator is characterized in that: comprise in the device of the leakage part of modulation signal in the device of the signal that is modulated to assigned frequency in order to the compensation demodulation:

Import the input of above-mentioned modulation signal;

Make the lower sideband signal of the modulation signal of supplying with by above-mentioned input and the ASO device that upper side band signal can restore under optimum condition;

Be connected in and be used between above-mentioned input and the ASO portion detecting the leakage part of above-mentioned modulation signal and producing the leakage signal detection device of missed signal pulse;

The missed signal compensator that the missed signal pulse that utilization is supplied with by above-mentioned leakage signal detection device partly compensates the leakage of input signal.

2,, it is characterized in that also being equipped with being connected between above-mentioned input and the above-mentioned leakage signal detection device, being maintained certain gain controller in order to the size of signal that will be by above-mentioned input input according to the lost signal compensator of claim 1.

3,, it is characterized in that above-mentioned leakage signal detection device can produce the pulse signal of high level less than the interval of setting at incoming signal level according to the lost signal compensator of claim 1 or 2.

4,, it is characterized in that above-mentioned missed signal compensator utilizes data value before the above-mentioned missed pulse to replace between pulse area with the missed pulse signal of being supplied with by above-mentioned leakage signal detection device signal data value accordingly according to the lost signal compensator of claim 1.

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