in still another embodiment as shown in fig6 the first detecting unit 31 includes an integrator 313 where the detecting signal is generated by adjusting the resistance r and capacitance c of the integrator 313 after the high frequency noise in the tv signal is filtered by a noise filter 35 the tv signal is transmitted to the digitizing circuit 33 after receiving the control signal emitted by the computing unit 32 the digitizing circuit 33 converts the tv signal into a digital signal in reference to the level value provided by the first detecting unit 31 where the tv signal is taken as 1 if the signal level is above the level value and taken as 0 if the signal level is below the level value the second detecting unit 34 is coupled to the digitizing circuit 33 to detect whether the digital signal contains a frame code the second detecting unit 34 decodes the frame code and compare it with the frame codes of various vbi types to determine whether the tv signal contains a vbi signal and to identify the type of the vbi signal if the tv signal contains the vbi signal the vbi signal is transmitted to a data slicer for subsequent processing the vbi detection apparatus 30 in fig3 can be applied to a vbi decoder to identify and filter non vbi noises and according to the type of a detected vbi signal lock a corresponding level value as a reference for digitizing the tv signal thereby enhancing.