Signal-processing apparatus compensating the distortion in a transmitted or recorded signal

Claim 2

A signal processing apparatus for processing an analog information signal, comprising: reference inserting means (17, 18, 19) for generating a reference waveform and inserting it at periodic intervals into said signal, said reference waveform varying in the range of amplitude variations of said information signal; reference detecting means (56A, 56B) for detecting the inserted reference waveform from the information signal, the detected reference waveform being affected by errors which may be present in the apparatus; and transfer circuit means (58A, 58B, 100A, 100B, 200A, 200B) having a transfer function describing the relationship between said reference waveform inserted by said inserting means and the error-affected reference waveform for transforming the waveform of said information signal to a distortion-free waveform according to said transfer function.

Claim 3

A signal processing apparatus as claimed in claim 1, wherein said transfer circuit means (58A, 58B) comprises: waveform generating means (71, 72) for generating a reference waveform identical to the reference waveform inserted by said inserting means; difference detecting means (70) for detecting a difference between said error-affected waveform and said identical waveform; and correcting means (75) for correcting said information signal with said difference detected by said difference detecting means.

Claim 4

A signal processing apparatus as claimed in claim 2, wherein said difference detecting means further comprises: a memory (73); and memory control means (74) for writing said detected difference into said memory as a function of the amplitude of said error-affected waveform and reading the stored difference out of the memory as a function of the amplitude of said information signal to said transfer circuit means.

Claim 5

4 . A signal processing apparatus as claimed in claim 1, wherein said transfer circuit means (100A, 100B) comprises: a first memory (102); means (103) for generating periodic data; memory control means for writing the periodic data into said first memory as a function of the amplitude of the detected reference waveform and reading the periodic data out of the first memory as a function of the amplitude of said signal; and a second memory (104) storing a reference waveform identical to the reference waveform inserted by said w inserting means, said second memory being responsive to said periodic data read out of said first memory for reading the reference waveform stored therein.

Claim 6

A signal processing apparatus as claimed in claim 1, wherein said transfer circuit means (200A, 200B) comprises: waveform generating means (203, 204) for generating a reference waveform identical to said reference waveform inserted by said inserting means; a memory (202); and memory control means (201) for writing the instantaneous amplitude value of said reference waveform generated by said waveform generating means as a function of the amplitude of said detected reference waveform and reading the stored amplitude value out of said memory as a function of the amplitude of said information signal as said distortion-free waveform.

Claim 7

A video recording and reproducing apparatus adapted to receive a video signal, comprising: channel separating means for separating said video signal into a first channel component having odd-numbered lines and a second channel component having even-numbered lines; reference inserting means operable during recording mode of the apparatus for generating a reference waveform and inserting it into a vertical blanking period of each of said first and second channel components and applying said components to a recording medium through first and second transducer means respectively, said reference waveform varying in a range from white level to black level; first reference detecting means coupled to said first transducer means for detecting the reference waveform from the first channel component reproduced by the first transducer means during playback mode of the apparatus, the detected reference waveform being affected by errors which may be present in the apparatus; second reference detecting means coupled to said second transducer means for detecting the reference waveform from the second channel component reproduced by the second transducer means during playback mode of the apparatus, the detected reference waveform being affected by errors which may be present in the apparatus; first transfer circuit means receptive of said reproduced first channel component and the reference waveform detected by said first detecting means, the first transfer circuit means having a first transfer function describing the relationship between said reference waveform inserted by said inserting means and the reference waveform detected by said first detecting means for transforming the waveform of said reproduced first channel component according to said first transfer function. second transfer circuit means receptive of said reproduced second channel component and the reference waveform detected by said second detecting means, the second transfer circuit means having a second transfer function describing the relationship between said reference waveform inserted by said inserting means and the reference waveform detected by said second detecting means for transforming the waveform of said reproduced second channel component according to said second transfer function; and channel recombining means for recombining output signals from said first and second transfer circuit means and generating a signal which is a replica of said video signal.

Claim 8

A video recording and reproducing apparatus adapted to receive a video signal, comprising: channel separating means for separating said video signal into a first channel component having odd-numbered lines and a second channel component having even-numbered lines; reference inserting means operable during recording mode of the apparatus for generating a reference waveform and inserting it into a vertical blanking period of each of said first and second channel components and applying said components to a recording medium through first and second transducer means respectively, said reference waveform varying in a range from white level to black level; first reference detecting means coupled to said first transducer means for detecting the reference waveform from the first channel component reproduced by the first transducer means during playback mode of the apparatus, the detected reference waveform being affected by errors which may be present in the apparatus; second reference detecting means coupled to said second transducer means for detecting the reference waveform from the second channel component reproduced by the second transducer means during playback mode of the apparatus, the detected reference waveform being affected by errors which may be present in the apparatus; first transfer circuit means receptive of said reproduced first channel component and the reference waveform detected by said first detecting means, the first transfer circuit means having a first transfer function describing the relationship between said reference waveform inserted by said inserting means and the reference waveform detected by said first detecting means for transforming the waveform of said reproduced first channel component according to said first transfer function. second transfer circuit means receptive of said reproduced second channel component and the reference waveform detected by said second detecting means, the second transfer circuit means having a second transfer function describing the relationship between said reference waveform inserted by said inserting means and the reference waveform detected by said second detecting means for transforming the waveform of said reproduced second channel component according to said second transfer function; and channel recombining means for recombining output signals from said first and second transfer circuit means and generating a signal which is a replica of said video signal.

Claim 9

An apparatus as claimed in claim 6, wherein said first transfer circuit means comprises: first waveform generating means for generating a first reference waveform identical to the reference waveform inserted by said / inserting means; first difference detecting means for detecting a first difference between the reference waveform detected by said first detecting means and the first reference waveform; and first correcting means for correcting said reproduced first channel component with the difference detected by said first difference detecting means, wherein said second transfer circuit means comprises: second waveform generating means for generating a second reference waveform identical to the reference waveform inserted by said inserting means; second difference detecting means for detecting a second difference between the reference waveform detected by said second detecting means and said second reference waveform; and second correcting means for correcting said reproduced second channel component with said difference detected by said second difference detecting means.

Claim 10

An apparatus as claimed in claim 7, wherein said first difference detecting means further comprises: a first memory; and first memory control means for writing said first difference into said first memory as a function of the amplitude of said error-affected waveform and reading the stored first difference out of the memory as a function of the amplitude of said reproduced first channel component, wherein said second difference detecting means further comprises: a second memory; and second memory control means for writing said second difference into said second memory as a function of the amplitude of said error-affected waveform and reading the stored second difference out of the memory as a function of the amplitude of said reproduced second channel component.

Claim 11

An apparatus as claimed in claim 6, wherein said first transfer circuit means comprises: a first memory; first periodic data generating means for generating first periodic data; first memory control means for writing the first periodic data into said first memory as a function of the amplitude of the reference waveform detected by said first reference detecting means and reading the first periodic data out of the first memory as a function of the amplitude of said reproduced first channel component; and a second memory storing a first reference waveform identical to the reference waveform inserted by said inserting means, said second memory reading the first reference waveform stored therein in response to said first periodic data read out of said first memory, wherein said second transfer circuit means comprises: a third memory; second periodic data generating means for generating second periodic data; second memory control means for writing the second periodic data into said third memory as a function of the amplitude of the reference waveform detected by said second reference detecting means and reading the second periodic data out of the third memory as a function of the amplitude of said reproduced second channel component; and a fourth memory storing a second reference waveform identical to the reference waveform inserted by said inserting means, said fourth memory reading the second reference waveform stored therein in response to said second periodic data read out of said third memory.

Claim 12

An apparatus as claimed in claim 9, wherein each of said first and second periodic data generating means comprises: clock generating means for generating a clock pulse synchronously with said reproduced video signal; and an address counter for counting said clock pulse and recyclically generating a series of address data as each of said periodic data.

Claim 13

An apparatus as claimed in claim 6, wherein said first transfer circuit means comprises: first waveform generating means for generating a first reference waveform identical to said reference waveform inserted by said inserting means; a first memory; and first memory control means for writing the instantaneous amplitude value of said first reference waveform as a function of the amplitude of the reference waveform detected by said first reference detecting means and reading the stored amplitude value out of said first memory as a function of the amplitude of said reproduced first channel component, wherein said second transfer circuit means comprises: second waveform generating means for generating a second reference waveform identical to said reference waveform inserted by said inserting means; a second memory; and second memory control means for writing the instantaneous amplitude value of said second reference waveform as a function of the amplitude of the reference waveform detected by said second reference detecting means and reading the stored amplitude value out of said second memory as a function of the amplitude of said reproduced second channel component;