US5077613A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Video camera with automatic focusing function
Assignee: Panasonic Holdings Corp
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Filing: 1990-01-30
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Granted: 1991-12-31
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Expires: 2010-01-30
Abstract
Abstract A video camera with an automatic focusing device includes a pre-process unit for eliminating a direct current component from a signal of the video camera and controlling the obtained signal so that the amplitude thereof can be at a constant level, which is disposed at the preceding stage of a signal processing unit for operating the focusing condition of an object from the signal of the video camera. An amplitude of a video signal to be inputted to the signal processing unit can be largely suppressed, thus providing a largely simplified circuit structure of a signal processing unit.
Inventors
- 👤 Yoshiaki Hirao
- 👤 Ryuichiro Kuga
- 👤 Masayuki Yoneyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:31
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/153; H04; H04N; H04N23/00; H04N23/60; H04N23/67; H04N23/673
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
207 words
A video camera with automatic focusing function comprising: a taking lens for image-forming an image of an object, said taking lens including a focusing lens; a photo-electric converting means for converting an image formed through said taking lens into an electrical signal; a pre-process means comprising a high-pass filter for eliminating a direct current component from an output signal of said photo-electric converting means, and a gain control means for detecting a maximum value of an amplitude level of an output signal of said high-pass filter in a signal extracting range to be set at a specific area of an image plane and for either amplifying or compressing the output signal of said high-pass filter so as to maintain the maximum value thus detected at a constant level; a signal processing means comprising a filter means for extracting a high frequency component having a frequency exceeding a specific frequency from an output signal of said pre-process means, and a detecting means for generating a focus signal corresponding to an amplitude level of the high frequency component thus extracted; a lens driving means for driving said focusing lens of said taking lens; and a control means for controlling said lens driving means in accordance with said focus signal.
Claim 2
Dependent Claim
207 words
A video camera with automatic focusing function comprising: a taking lens for image-forming an image of an object, said taking lens including a focusing lens; a photo-electric converting means for converting an image formed through said taking lens into an electrical signal; a pre-process means comprising a high-pass filter for eliminating a direct current component from an output signal of said photo-electric converting means, and a gain control means for detecting a maximum value of an amplitude level of an output signal of said high-pass filter in a signal extracting range to be set at a specific area of an image plane and for either amplifying or compressing the output signal of said high-pass filter so as to maintain the maximum value thus detected at a constant level; a signal processing means comprising a filter means for extracting a high frequency component having a frequency exceeding a specific frequency from an output signal of said pre-process means, and a detecting means for generating a focus signal corresponding to an amplitude level of the high frequency component thus extracted; a lens driving means for driving said focusing lens of said taking lens; and a control means for controlling said lens driving means in accordance with said focus signal.
Claim 3
Dependent Claim
26 words
A video camera as claimed in claim 1, wherein a cutoff frequency of side high-pass filter is set at a frequency of at least 0.1 MHz.
Claim 4
Dependent Claim
299 words
A video camera comprising: a taking lens for image-forming an image of an object, said taking lens including a focusing lens; a photo-electric converting means for converting an image formed through said taking lens into an electrical signal; a pre-process means for processing an output signal of said photo-electric converting means so as to eliminate therefrom a direct current component and to make an amplitude of the direct current component eliminated signal at a constant level; a signal processing means for extracting a high frequency component having a frequency exceeding a specific frequency from an output signal of said pre-process means and generating a focus signal corresponding to an amplitude level of the high frequency component thus extracted; a lens driving means for driving said focusing lens of said taking lens; and a control means for controlling said lens driving means in accordance with said focus signal; wherein said pre-process means comprises; a low-pass filter for eliminating a signal component having a frequency exceeding a specific frequency from the output signal of said photo-electric converting a first gain control means for detecting a maximum value of an output signal of said low-pass filter in a signal extracting range and for either amplifying or compressing the output signal of said low-pass filter so as to maintain the maximum value thus detected at a constant level; a high-pass filter for extracting only a signal having a frequency exceeding a specific frequency from an output signal of said first gain control means; and a second gain control means for detecting a maximum value of an output signal of said high-pass filter in said signal extracting range and for either amplifying or compressing the output signal of said high-pass filter so as to maintain the maximum value thus detected at a constant level.
Claim 5
Dependent Claim
299 words
A video camera comprising: a taking lens for image-forming an image of an object, said taking lens including a focusing lens; a photo-electric converting means for converting an image formed through said taking lens into an electrical signal; a pre-process means for processing an output signal of said photo-electric converting means so as to eliminate therefrom a direct current component and to make an amplitude of the direct current component eliminated signal at a constant level; a signal processing means for extracting a high frequency component having a frequency exceeding a specific frequency from an output signal of said pre-process means and generating a focus signal corresponding to an amplitude level of the high frequency component thus extracted; a lens driving means for driving said focusing lens of said taking lens; and a control means for controlling said lens driving means in accordance with said focus signal; wherein said pre-process means comprises; a low-pass filter for eliminating a signal component having a frequency exceeding a specific frequency from the output signal of said photo-electric converting a first gain control means for detecting a maximum value of an output signal of said low-pass filter in a signal extracting range and for either amplifying or compressing the output signal of said low-pass filter so as to maintain the maximum value thus detected at a constant level; a high-pass filter for extracting only a signal having a frequency exceeding a specific frequency from an output signal of said first gain control means; and a second gain control means for detecting a maximum value of an output signal of said high-pass filter in said signal extracting range and for either amplifying or compressing the output signal of said high-pass filter so as to maintain the maximum value thus detected at a constant level.
Claim 6
Dependent Claim
26 words
A video camera as claimed in claim 3, wherein a cutoff frequency of said high-pass filter is set at a frequency of at least 0.1 MHz.
Claim 7
Dependent Claim
28 words
A video camera as claimed in claim 3, wherein a cutoff frequency of said low-pass filter is set at a frequency less than or equal to 4 MHz.
Claim 8
Dependent Claim
229 words
A video camera with automatic focusing function comprising: a taking lens for image-forming an image of an object, said taking lens including a focusing lens; a photo-electric converting means for converting an image formed through said taking lens into an electrical signal; a pre-process means comprising a high-pass filter for eliminating a direct current component from an output signal of said photo-electric converting means, and a gain control means for detecting a maximum value of an amplitude level of an output signal of said high-pass filter in a signal extracting range to be set at a specific area of an image plane and for either amplifying or compressing the output signal of said high-pass filter so as to maintain the maximum value thus detected at a constant level; a signal processing means comprising an analog-to-digital converting means for converting an output signal of said pre-process means into a digital signal, a filter means for extracting a high frequency component having a frequency which is higher than than a specific frequency from an output signal of said analog-to-digital converting means, and a detecting means for generating a focus signal corresponding to an amplitude level of the high frequency component thus extracted; a lens driving means for driving said focusing lens of said taking lens; and a control means for controlling said lens driving means in accordance with said focus signal.
Claim 9
Dependent Claim
229 words
A video camera with automatic focusing function comprising: a taking lens for image-forming an image of an object, said taking lens including a focusing lens; a photo-electric converting means for converting an image formed through said taking lens into an electrical signal; a pre-process means comprising a high-pass filter for eliminating a direct current component from an output signal of said photo-electric converting means, and a gain control means for detecting a maximum value of an amplitude level of an output signal of said high-pass filter in a signal extracting range to be set at a specific area of an image plane and for either amplifying or compressing the output signal of said high-pass filter so as to maintain the maximum value thus detected at a constant level; a signal processing means comprising an analog-to-digital converting means for converting an output signal of said pre-process means into a digital signal, a filter means for extracting a high frequency component having a frequency which is higher than than a specific frequency from an output signal of said analog-to-digital converting means, and a detecting means for generating a focus signal corresponding to an amplitude level of the high frequency component thus extracted; a lens driving means for driving said focusing lens of said taking lens; and a control means for controlling said lens driving means in accordance with said focus signal.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-12-30 | 1995-07-01 | 1995-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-30 | 1999-07-01 | 1999-12-31 | $3760.00 | Window Closed / Lapsed |
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