US4559559A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Noise reducing circuit
Assignee: Canon Inc
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Filing: 1982-06-16
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Granted: 1985-12-17
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Expires: 2002-06-16
Abstract
Abstract A noise reducing circuit, including a circuit to reduce noises contained in a low frequency band with a clamping circuit, having a first circuit with an attenuating characteristic near a first frequency which is the upper frequency limit of a noise that can be reduced by the clamping circuit and a second circuit with a characteristic of the first circuit. The first circuit is provided in front of the clamping circuit and the second circuit following the clamping circuit.
Inventors
- 👤 Seiji Hashimoto
- 👤 Nobuyoshi Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:02
CPC Classifications
H; H04; H04N; H04N25/00; H04N25/60; H04N25/63; H04N25/633
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
90 words
A noise reducing circuit, comprising: (a) a clamping circuit to clamp signals; (b) a first circuit, being provided at an input side of said clamping circuit and having such characteristic as having an attenuating characteristic at least at a first frequency constituting the upper limit frequency of noises which can be reduced by said clamping circuit; and (c) a second circuit, being provided at an output side of said clamping circuit and having a characteristic to emphasize the output signal of the clamping circuit, at least said first frequency thereof.
Claim 2
Dependent Claim
90 words
A noise reducing circuit, comprising: (a) a clamping circuit to clamp signals; (b) a first circuit, being provided at an input side of said clamping circuit and having such characteristic as having an attenuating characteristic at least at a first frequency constituting the upper limit frequency of noises which can be reduced by said clamping circuit; and (c) a second circuit, being provided at an output side of said clamping circuit and having a characteristic to emphasize the output signal of the clamping circuit, at least said first frequency thereof.
Claim 3
Dependent Claim
46 words
A noise reducing circuit, according to claim 1, having such features that the above-mentioned noises have a second frequency at which a frequency characteristic of noise level changes, and the noise level will be almost in inverse proportion to frequency at bands below said second frequency.
Claim 4
Dependent Claim
29 words
A noise reducing circuit according to claim 2, in which the first circuit has a nature to lower the above-mentioned second frequency down nearer to the above-mentioned first frequency.
Claim 5
Dependent Claim
18 words
A noise reducing circuit according to claim 1, in which the above-mentioned first circuit includes an equalizer circuit.
Claim 6
Dependent Claim
21 words
A noise reducing circuit according to claim 1, or claim 4 in which the above-mentioned second circuit includes an equalizer circuit.
Claim 7
Dependent Claim
122 words
An image pick-up apparatus, comprising: (a) an image pick up means to convert light information into a video signal; (b) an amplifying circuit to amplify the video signal obtained by said image pick up means; (c) a clamping circuit to clamp the video signal amplified by said amplifying circuit; (d) a first circuit being provided at an input side of said clamping circuit, and having an attenuating characteristic at least at a first frequency constituting the upper limit frequency of noises which can be reduced by said clamping circuit; and (e) a second circuit being provided at an output side of said clamping circuit and having a characteristic to emphasize the output signal of the clamping circuit, at least said frequency thereof.
Claim 8
Dependent Claim
122 words
An image pick-up apparatus, comprising: (a) an image pick up means to convert light information into a video signal; (b) an amplifying circuit to amplify the video signal obtained by said image pick up means; (c) a clamping circuit to clamp the video signal amplified by said amplifying circuit; (d) a first circuit being provided at an input side of said clamping circuit, and having an attenuating characteristic at least at a first frequency constituting the upper limit frequency of noises which can be reduced by said clamping circuit; and (e) a second circuit being provided at an output side of said clamping circuit and having a characteristic to emphasize the output signal of the clamping circuit, at least said frequency thereof.
Claim 9
Dependent Claim
47 words
An image pick up apparatus according to claim 6, having such features that the above-mentioned noises have a second frequency at which a frequency characteristic of noise level changes, and the noise level will be almost in inverse proportion to frequency at bands below said second frequency.
Claim 10
Dependent Claim
31 words
An image pick up apparatus according to claim 7, in which the above-mentioned first circuit has such nature as lowering the above-mentioned second frequency down nearer to the above-mentioned first frequency.
Claim 11
Dependent Claim
22 words
An image pick up apparatus according to claim 7, in which the above-mentioned noises are mainly generated from the above-mentioned amplifying circuit.
Claim 12
Dependent Claim
24 words
An image pick up apparatus according to claim 9, in which as the above-mentioned amplifying circuit, metal oxide semi-conductors-field effect transistors (MOS-FET) are used.
Claim 13
Dependent Claim
23 words
An image pick up apparatus according to claim 9, in which the above-mentioned image pick up means includes a solid state image sensor.
Claim 14
Dependent Claim
30 words
An image pick up apparatus according to claim 7, in which a clamping cycle of the clamping circuit is a cycle of a horizontal synchronizing signal of the video signal.
Claim 15
Dependent Claim
34 words
An image pick up apparatus according to claim 6, which further comprises a low band filter being provided between the amplifying circuit and the clamping circuit and eliminating clock elements in the video signal.
Claim 16
Dependent Claim
19 words
An image pick up apparatus according to claim 6, in which the above-mentioned first circuit includes an equalizer circuit.
Claim 17
Dependent Claim
22 words
An image pick up apparatus according to claim 6 or claim 14, in which the above-mentioned second circuit includes an equalizer circuit.
Claim 18
Dependent Claim
36 words
An image pick up apparatus according to claim 6, which further comprises a black level setting circuit being provided after the second circuit and setting a black level of the video signal at a new value.
References Cited (Backward Citations)
US4122776A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-16 | 1989-06-17 | 1989-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-16 | 1993-06-17 | 1993-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-16 | 1997-06-17 | 1997-12-17 | $7700.00 | Window Closed / Lapsed |