Television – Camera – system and detail – Combined image signal generator and general image signal...
Reexamination Certificate
1997-12-24
2001-05-29
Garber, Wendy R. (Department: 2612)
Television
Camera, system and detail
Combined image signal generator and general image signal...
C348S345000
Reexamination Certificate
active
06239838
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a video camera, and more particularly to an improved video camera for detecting a focus value engaged to an output picture which makes it possible to detect a focus value from a picture signal by being engaged to a final output picture, for thereby enabling a signal process and a automatic focus control to be carried out in greater precision.
2. Description of the Prior Art
As shown in
FIG. 1
, a conventional camera apparatus includes: an optical system
1
having an object lens, a zoom lens and an iris, and carrying out a photo-electric conversion in order for an object picture signal to be converted to an electric signal; an AGC (automatic gain control) circuit
2
for automatically controlling the picture signal outputted from the optical system
1
; a signal process unit
3
for processing and outputting a picture signal outputted from the AGC circuit
2
; an A/D (analog/digital) converter
4
for converting the gain-controlled picture signal from AGC
2
to a digital signal; a Y/C separation circuit
5
for separating the converted signal into a luminance signal and a color signal; an area varying unit
6
for receiving the digital luminance signal converted in the A/D converter
4
and carrying out a zoom area varying function; a focus value detector
7
for receiving an output signal of the area varying unit
6
and detecting a focus value Fv so as to carry out an automatic focus; a controller
8
for receiving a telephoto signal and a widephoto signal, and outputting a control signal so as to drive the optical system
1
in response to the focus value outputted from the focus value detector
7
; and a driving unit
9
for driving the optical system
1
under the control of the controller
8
.
The operation of the thusly constituted conventional camera apparatus will now be described.
An optical signal representing an object from the optical system
1
is converted through a CCD (charge-coupled device) to an electric picture signal, which is then gain-controlled in the AGC circuit
2
and outputted via the signal process unit
3
. The gain-controlled picture signal is converted to a digital signal in the A/D converter
4
so that an area varying function is carried out through the area-varying unit
6
, and together therewith a focus value Fv for the luminance signal is detected in the focus value detector
7
.
The focus value Fv is applied to the controller
8
which in turn receives an externally applied telephoto/widephoto signal T/W so as to drive the optical system
1
via the driving unit
9
, for thereby carrying out a zoom-in/zoom-out function and an AF (automatic focusing) operation in accordance with the focus value Fv.
In more detail, the optical system
1
, the AGC circuit
2
, the A/D converter
4
and the Y/C separation circuit
5
process an image signal to derive a luminance signal which is provided to the area varying unit
6
. The controller
8
outputs a control signal to the area varying unit
6
, but the controller
8
does not output a signal directly to the Y/C separation circuit
5
.
However, the signal for carrying out the AF function in the conventional camera system is employed so as to directly apply the CCD output signal to a focus value detecting signal, so that when a zoom-in/zoom-out function is carried out against an object beyond a focus range, an accurate focusing becomes difficult.
That is, because an input data signal for generating an AF estimate value is based upon the output of the AGC circuit, when digital zooming is carried out, a focusing of the accordingly appearing picture becomes performed against an object other than the finally outputted actual picture, thereby resulting in an optical parallax against the actual object.
SUMMARY OF THE INVENTION
It is another object of the present invention to provide a camera apparatus for performing an automatic focusing by using a luminance signal outputted from a digital zoom process unit as a focus value detecting signal, thereby eliminating an optical parallax and realizing an accurate automatic focusing.
It is an object of the invention to provide an apparatus (and the method inherent thereto) that avoids an optical parallax error in a situation where the optical focal point does not correspond to the center of a digitally zoomed image area. Such an apparatus according to the invention can accurately focus when more than one object is within the zoomed image area.
To achieve the above-described objects, there is provided a camera apparatus and method inherent therein for detecting a focus value based upon an output picture, the apparatus comprising: an object-shooting means for photo-shooting an object and converting an associated optical image electric signals; signal process means for applying a digital signal process and a digital zoom process to the converted picture signal to produce a digital luminance signal, a digital color signal, a digital zoom luminance signal and a digital zoom color signal, respectively; focus value detecting means for receiving at least one of the digital zoom luminance and digital zoom color signals and detecting a focus value therein; and a controller for carrying out AF (automatic focusing) control using the focus value detected by the focus value detecting means.
Further, to achieve the above-described objects, there is provided a camera apparatus and method inherent therein for detecting a focus value based upon an output picture, the apparatus comprising: object-shooting means for photo-shooting an object and converting an associated optical image into electric signals; signal process means for applying a digital signal process to the converted picture signal to produce a digital luminance signal and a digital color signal; zoom process means for receiving the digital luminance and color signals and applying a digital zoom process function to produce a digital zoom luminance signal and a digital zoom color signal; switching means for selecting one of the digital luminance signal and the digital zoom luminance signal; focus value detecting means for receiving the signal selected by the switching means and detecting the focus value therein; and a controller for controlling the switching means depending upon a quality level of a digital zooming state, and carrying out an AF control in accordance with the focus value detected by the focus value detecting means.
The foregoing and other objectives of the present invention will become more apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
REFERENCES:
patent: 5428391 (1995-06-01), Murata et al.
patent: 5867217 (1999-02-01), Okino et al.
patent: 5933187 (1999-08-01), Hirasawa et al.
patent: 406133206A (1994-05-01), None
Lee Seoung Eog
Park Jin-Soo
Yeo Myung Keun
Garber Wendy R.
LG Electronics Inc.
Tillery Rashawn N.
LandOfFree
Camera apparatus for detecting focus value engaged to output... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Camera apparatus for detecting focus value engaged to output..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Camera apparatus for detecting focus value engaged to output... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2497576