Waveform equalizer for obtaining corrected signal and apparatus for reproducing information

波形均衡器(6)用于对从数据载体(1)上读出的读信号执行波形均衡从而获得校正信号S′。波形均衡器(6)有一个第一滤波器(61)，能够对所述读信号进行滤波处理，一个限幅器(62)，能够通过将所述读信号的幅度值限定至一预定值从而得到一个被限幅的读信号S#-[LIM]。提供一个第二滤波器(63)，能够对所述被限幅的读信号S#-[LIM]执行滤波处理。此外还有一个能够将分别由所述第一滤波器(61)和第二滤波器(63)执行滤波处理后得到的信号相加的加法器(64)，能够产生一个如所述校正读信号S′的加法结果。所述波形均衡器(6)对那些幅度小于所述预定的幅度限定值的信号的信号频率响应，在频率从零到信号频率响应在最大幅值处对应的频率值之间的一个频域中有一槽口。对记录在信息载体上的信息的信息再现的装置，包括一个波形均衡器(6)能够以较高的S/N比和较低的数据跳动读出信息。因此，该信息再现装置可适用于有较高字节密度，同时又有可接受的S/N比和数据跳动的情况。 The waveform equalizer ( 6 ) for obtaining a corrected signal S' by performing a waveform equalization to a read signal S read out from an information carrier ( 1 ). The waveform equalizer ( 6 ) has a first filter ( 61 ) able to perform a filtering process to said read signal S, and an amplitude limiting means ( 62 ) able to obtain an amplitude limited read signal SLIM by limiting an amplitude level of said read signal S by a predetermined amplitude limitation value. A second filter ( 63 ) is provided which is able to perform a filtering process to said amplitude limited read signal SLIM. Further, an adder ( 64 ) is present which is able to add the signals obtained by performing the filtering process by each of said first ( 61 ) and second filters ( 63 ), able to generate an addition result as said corrected read signal S'. The signal frequency response of said waveform equalizer ( 6 ) to signals having an amplitude smaller than said predetermined amplitude limitation value, has a notch in a first frequency region from zero to a frequency at which the signal frequency response is at a maximum amplitude. The apparatus for reproducing information recorded on an information carrier ( 1 ), having the waveform equalizer ( 6 ) is able to read the information with a higher S/N ratio and a lower data jitter. As a result the information reproducing apparatus can be applied for a higher bit density and at the same time having a acceptable S/N ratio and data jitter.