EP0312266A2
Expired / Lapsed
EP
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Apparatus for reproducing recorded information with cross modulation suppression
Assignee: Pioneer Corp
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Filing: 1988-10-07
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Granted: —
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Expires: 2008-10-07
Abstract
Abstract Apparatus for reproducing recorded information on a video disk (1), the recorded information including an FM signal containing video information, an EFM signal containing audio signals and cross modulation components of the FM and EFM signals within the bandwidth of the video signal. The apparatus includes cross modulation suppressing circuitry (4) consisting of an amplifier with a gain which decreases at frequencies equal to the frequency components of the cross modulation components falling within the frequency band of the FM video signal. In this way the cross modulation components are suppressed without suppressing the FM signal, thereby preventing the cross modulation components from interfering with the FM signal.
Inventors
- 👤 Hitoshi C/O Pioneer Senso
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 02:03
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/91; H04N5/911; G; G11; G11B; G11B20/00; G11B20/02; G11B20/06; G11B20/22; H04N9/00; H04N9/79; H04N9/80; H04N9/802
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
128 words
Apparatus for reproducing an FM signal of a predetermined bandwidth recorded on a recording medium along with another known signal having a bandwidth outside the bandwidth of the FM signal, and cross modulation components of said FM signal and said other known signal said cross modulation components having frequency components in the bandwidth of the FM signal, said apparatus comprising: pickup means for reading a signal, including said FM signal, from said recording medium, and amplifying means for amplifying said signal including said FM signal read from said recording medium, said amplifying means having a frequency response characteristic such that the gain of said amplifying means decreases at frequencies equal to the frequency components of said cross modulation components that fall within the bandwidth of said FM signal.
Claim 2
Dependent Claim
128 words
Apparatus for reproducing an FM signal of a predetermined bandwidth recorded on a recording medium along with another known signal having a bandwidth outside the bandwidth of the FM signal, and cross modulation components of said FM signal and said other known signal said cross modulation components having frequency components in the bandwidth of the FM signal, said apparatus comprising: pickup means for reading a signal, including said FM signal, from said recording medium, and amplifying means for amplifying said signal including said FM signal read from said recording medium, said amplifying means having a frequency response characteristic such that the gain of said amplifying means decreases at frequencies equal to the frequency components of said cross modulation components that fall within the bandwidth of said FM signal.
Claim 3
Dependent Claim
24 words
The apparatus as claimed in claim 1 further including a limiter circuit means for limiting the amplitude of the output from said amplifier means.
Claim 4
Dependent Claim
82 words
The apparatus as claimed in claim 2 further including switch means positioned between said amplifying means and said limiter, one input to said switch means being the output from said applying means, another input to said switch means corresponding to said read signal without being amplified by said amplifying means; and switch command circuit means responsive to command data and having an output coupled to said switch means for causing either of the inputs to said switch means to be output therefrom.
Claim 5
Dependent Claim
93 words
The apparatus as claimed in claim 3 wherein the recording medium is a video disk and said command data are data designating whether the video disk is of the CAV or CLV type and the radial position of the pickup means relative to said disk, said switch command circuit means including means for causing said switch means to transfer said another input to said limiter when the command data indicates a CAV disk and the pickup means is positioned to read from positions on the CAV disk interior to a predetermined disk radius.
Claim 6
Dependent Claim
46 words
The apparatus as claimed in claim 1 wherein the frequencies of said cross modulation components are higher than the carrier frequency of said FM signal, said amplifying means having a frequency response characteristic such that the gain of said amplifying means decreases with increasing frequency components.
Claim 7
Dependent Claim
97 words
The apparatus as claimed in claim 1 wherein said amplifying means comprises a first delay means receiving a signal representing said read signal, a second delay means receiving the output from said first delay means, first adder means receiving the output from said second delay means and said signal representing said read signal, attenuator means for attenuating the output from said first adder means, and second adder means receiving the output from said attenuator means and the output from said first delay means, the output from said second adder means being the output from said amplifying circuit.
Claim 8
Dependent Claim
34 words
The apparatus as claimed in claim 3 further including FM carrier frequency detecting means for controlling the gain versus frequency characteristics of said amplifying means in accordance with the frequency of the FM carrier.
References Cited (Backward Citations)
No citation records indexed.
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