Patent EP0127451A1 successfully refreshed from Google Patents.
EP0127451A1
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Automatic focus control system for video camera
Assignee: Sony Corp
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Filing: 1984-05-24
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Granted: —
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Expires: 2004-05-24
Abstract
Abstract In an automatic focus control system for video cameras part of the object light is diverted through an optical sub-system (22) to a detecting unit (30) the output signals of which are used for controlling focusing of the optical main system. The output signals from the detecting unit are used for vari- ably controlling a diaphragm (21) in the sub-system. The state of focus of the main optical system (2,3,4, 5 and 8) is sensed and depending on whether the main optical system is in considerably defocused state or approximately focused state, the effective diameter of the diaphragm (21) in the optical sub-system is reduced or enlarged, respectively.
Inventors
- 👤 Yasuo Nakada
- 👤 Yukihiro Kato
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 21:15
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/36; G02B7/38; H; H04; H04N; H04N23/00; H04N23/60; H04N23/67; H04N23/671; H04N23/673
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
100 words
An automatic focus control system for a video camera comprising: a main optical system (5) for directing object light at first means (10) for photoelectrically converting the object light from the main optical system into imaging signals, an optical sub-system (22) for conducting a part of the object light to second means (31A, B, 32A, B) for converting part of the object light from said sub-system into imaging signals, a diaphragm (21) for controlling light volume in the optical sub-system,and an automatic focus control unit (40) for detecting a focused state based on said imaging signals from said second means.
Claim 2
Dependent Claim
100 words
An automatic focus control system for a video camera comprising: a main optical system (5) for directing object light at first means (10) for photoelectrically converting the object light from the main optical system into imaging signals, an optical sub-system (22) for conducting a part of the object light to second means (31A, B, 32A, B) for converting part of the object light from said sub-system into imaging signals, a diaphragm (21) for controlling light volume in the optical sub-system,and an automatic focus control unit (40) for detecting a focused state based on said imaging signals from said second means.
Claim 3
Dependent Claim
24 words
The automatic focus control system as claimed in claim 1 wherein said second diaphragm (21) is controlled by said automatic focus control unit (40).
Claim 4
Dependent Claim
26 words
The automatic focus control system claimed in claim 2 wherein said automatic focus control section (40) comprises contrast detecting means whereby to determine the focused state.
Claim 5
Dependent Claim
31 words
The automatic focus control system for video camera as claimed in claim 3 wherein a beam splitter (8) is provided for splitting object light into main system light and sub-system light.
Claim 6
Dependent Claim
59 words
The automatic focus control system according to any one of the preceding claims including means (41, 42, 45) for varying the effective diameter of said diaphragm in accordance with the degree of defocus of the main optical system, the effective diameter being reduced when the degree of defocus is larger and increased when the state of defocus is smaller.
Claim 7
Dependent Claim
17 words
A video camera including an automatic focus control system according to any one of the preceding claims.
References Cited (Backward Citations)
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