Television – Camera – system and detail – Combined image signal generator and general image signal...
Reexamination Certificate
1998-12-09
2003-11-18
Garber, Wendy R. (Department: 2712)
Television
Camera, system and detail
Combined image signal generator and general image signal...
C348S240200, C348S208600, C348S347000, C348S357000
Reexamination Certificate
active
06650367
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a lens device having a zoom lens, an imaging device equipped with this lens device and adapted to perform electronic zooming, an imaging system, an lens control system and a computer readable storage medium.
2. Description of the Related Art
FIG. 4
is a block diagram showing the configuration of a conventional lens-interchangeable video camera. In this figure, reference numeral
100
designates an interchangeable lens unit; and
200
a camera body unit to which the interchangeable lens unit is detachably attached. In the interchangeable lens unit
100
, reference numeral
101
denotes a fixed front lens group;
102
a variator or zoom lens group for zooming or changing a magnification;
103
a fixed lens group;
104
a compensator or focusing lens group for performing both functions of compensating and focusing. These lens groups
101
to
104
constitute a lens system of inner focusing type.
Reference numeral
106
designates a stepping motor for moving the variator lens group
102
;
108
a rotation shaft that is connected to a gear
107
through the stepping motor
106
and has a screw;
109
a rack that is movably mounted on the rotation shaft
108
and provided with the variator lens group
102
. Reference numeral
105
denotes a driver for driving the stepping motor
106
; and
110
a zoom encoder for detecting the position of the variator lens group
102
.
Reference numeral
112
designates a stepping motor for moving the compensator lens group
104
;
113
a rotation shaft that is directly connected to a stepping motor
112
and has a screw;
114
a rack that is movably mounted on the rotation shaft
113
and provided with the compensator lens group
104
. Reference numeral
111
denotes a driver for driving the stepping motor
112
. Reference numeral
115
designates a microcomputer (hereunder sometimes referred to as a lens microcomputer) that communicates with a microcomputer
208
of the camera body unit
200
and controls each of the drivers.
105
and
111
and receives position detection information from the zoom encoder
110
.
Further, in the camera body unit
200
, reference numeral
201
denotes an imager such as CCD;
202
CDS/AGC circuit for performing a correlated double sampling operation and an automatic gain control operation;
203
A/D converter;
204
a signal processing circuit;
205
an enlargement processing circuit for performing electronic zooming;
206
a signal processing circuit;
207
D/A converter;
208
a microcomputer (hereunder sometimes referred to as a camera microcomputer) for controlling the entire video camera and for communicating with the lens microcomputer
115
;
210
and
211
zoom switches for moving the variator lens group in a tele or telephoto direction and a wide or wide-angle direction, respectively;
212
and
213
focus switches for moving a focus position to an infinite focus position and to a shortest focus position, respectively; and
209
a group of these switches.
Next, an operation of this video camera will be described hereinbelow. When the interchangeable lens unit
100
is attached to the camera body unit
200
, electric power is supplied from the camera body unit
200
to the interchangeable lens unit
100
. Then, an image is formed on the imager
201
from light that comes from an object through the lens groups
101
to
104
. Video signals obtained by photoelectric conversion performed in the imager
201
are processed by the CDS/AGC circuit
202
. Subsequently, the video signals are converted by the A/D converter
203
into digital video signals which are then sent to the signal processing circuit
204
. After the signal processing circuit
204
gamma-corrects the digital video signals, the enlargement processing circuit
205
performs enlargement processing (to be described later) on the gamma-corrected video signals. Further, the signal processing circuit
206
performs balanced modulation on color signals. The processed signals are converted by the D/A converter
207
into digital analog video signals which are then sent to VTR (not shown).
Next, operations of the lens microcomputer
115
and zooming and focusing operations will be described hereinbelow. When the zooming or focusing operation is designated, the lens microcomputer
115
determines the rotation speed and direction of each of the motors
106
and
112
by executing programs. Further, the lens microcomputer
115
outputs control signals representing the determined rotation speed and direction, and controls the stepping motors
106
and
112
through the drivers
105
and
111
, respectively. Incidentally, regarding the zooming operation, the lens microcomputer
115
determines the rotation direction of the motor
106
according to the states of the switches
210
and
211
, which are represented by signals outputted from the camera microcomputer
208
, respectively. Regarding the focusing operation, in the case of adjusting focus by a manual operation, the rotation direction of the motor
112
is determined according to the states of the switches
212
and
213
, which are represented by signals sent from the camera microcomputer
208
. On the other hand, in the case of adjusting focus by an autofocusing (AF) operation, the rotation direction of the motor
112
is determined by executing AF processing routine in the lens microcomputer
115
.
Each of the motors
106
and
112
rotate by being controlled according to the aforementioned control signals. Thus, the rotation shaft
108
rotates through the gear
107
. Moreover, the rotation shaft
113
rotates. Each of the racks
109
and
114
moves back and forth together with a corresponding one of the lens groups
102
and
104
. Consequently, predetermined zoomed and focused conditions of the video camera are obtained.
Next, enlargement processing (namely, electronic zooming) to be performed on an image in the enlargement processing circuit
205
by utilizing linear interpolation will be described hereinbelow. Enlargement processing is performed by operating the zoom switches
210
and
211
by a cameraman. When an original image shown in the leftside part of
FIG. 5A
is expanded into an enlarged image shown in the right-side part thereof, scan lines representing the original image are as illustrated in the left-side part of
FIG. 5B
, and scan lines representing the enlarged image are as illustrated in the right-side part thereof. In this case, the scan lines, which represent the enlarged image and are respectively indicated by dashed lines in the right-side part of
FIG. 5B
, are newly formed from the scan lines A to F representing the original image shown in the-left-side part thereof. Thus, each of the scan lines respectively indicated by dashed lines is obtained by multiplying data representing corresponding ones of scan lines, which are respectively indicated by solid lines in the right-side part of
FIG. 5B
, by weight factors (or correction coefficients) corresponding to the distances thereof and adding up resultant data. The original image can be enlarged at an arbitrary enlargement magnification by performing such linear interpolation processing in the vertical and horizontal directions.
FIG. 6
shows the configuration of the enlargement processing circuit
205
. For simplicity of description, this figure illustrates only the vertical enlargement processing. As shown in
FIG. 6
, input video signals
300
are stored in a memory circuit
301
under the control of a memory control signal generating circuit
302
. Microcomputer interface circuit
304
receives an enlargement magnification and enlargement information from the camera microcomputer
208
. Based on this, an enlarged magnification determining circuit
303
outputs the enlargement magnification to the memory control signal generating circuit
302
and an interpolation coefficient generating circuit
308
. The memory control signal generating circuit
302
reads signals, which respectively represent an nth line and an (n−1)th line de
Canon Kabushiki Kaisha
Garber Wendy R.
Morgan & Finnegan L.L.P.
Villecco John M.
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