Television – Camera – system and detail – Optics
Reexamination Certificate
2001-02-07
2004-09-07
Ho, Tuan (Department: 2612)
Television
Camera, system and detail
Optics
C396S217000
Reexamination Certificate
active
06788344
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an exchangeable connecting device between a video camera and an automatic iris lens, especially an exchangeable connecting device arbitrary between video camera M and an automatic iris lens L having galvanometer control circuit p or an automatic iris lens L not having galvanometer control circuit p.
2. Description of the Prior Art
FIG. 4
shows a conventional connecting device between video camera M such as a CCD (Charged Couple Device) camera, an area image sensor and automatic iris lens L. Referring
FIG. 4
, an example of operational principal of automatic iris lens L and video camera M is explained.
A light signal passing through lens a is changed into electrical signal by area sensor b, amplified by AGC amplifier circuit c, processed by signal processing circuit d, and output as regular video signal IVpp.
On the other hand, a part of electrical signal of area sensor b is amplified by constant amplifier r of 6 dB to 12 dB and output as light control signal
1
for automatic iris lens L. Light control signal
1
is integrally amplified by level setting circuit e and provides driving DC current
2
, for galvanometer f of iris control mechanism of automatic iris lens L. Variable resistor g is to set the iris value to a suitable value. Namely, DC current
2
increases according to an increase in light control signal
1
and closes iris I. On the contrary DC current
2
decreases according to a decrease in light control signal
1
and opens iris I, so that video camera M operates according to a suitable light control signal
1
.
Normally, camera M needs various lens, therefore camera M and the lens are independent and according to necessity, connected by a thread.
On the other hand, information such as said light control signal
1
or driving DC current
2
are connected by a cable and connector.
However, there are two type of automatic iris lens L as follows;
1. VS (Video Signal) control type automatic iris lens L
1
.
This VS control type automatic iris lens L
1
includes galvanometer control circuit p in which iris I is control by a part of light control signal
1
of a video signal.
FIG. 5
shows a connecting device of conventional video camera M
1
and VS control type automatic iris lens L
1
having galvanometer control circuit p and the same or similar numerals used for the same or similar parts of FIG.
4
and so on.
Video camera M
1
and VS control type automatic iris lens L
1
have connectors k, k connected by a cable (not shown) respectively connecting terminals {circle around (1)}, {circle around (2)}, {circle around (3)}, {circle around (4)} of connectors k, k. Terminal {circle around (1)} is connected to an electric circuit, terminals {circle around (2)}, {circle around (2)} are NC terminals (no connection), terminals {circle around (3)}, {circle around (3)} are connected to light control signal
1
, terminals {circle around (4)}, {circle around (4)} are connected to ground (earth).
Operation of this circuit is as follows; light control signal
1
input from terminals {circle around (3)} is integral amplified by driving amplifier h, and video control signal
1
of video camera M
1
set by variable resistor g reaches a level voltage corresponding to regular video signal IVpp, current in driving coil CL
1
of galvanometer f decreases and controls iris I. Braking coil CL
2
is to suppress rapid operation of driving coil CL
1
. Braking coil CL
2
detects reverse voltage generated in galvanometer f, this reverse voltage is amplified in amplifier j, feedback to driving amplifier h, controls the movement of galvanometer f so as to be smooth and stable operation.
2. DC control type automatic iris lens L
2
.
This DC control type automatic iris lens L
2
(
FIG. 6
) is intended to lower the lens price, which only includes galvanometer f and does not include galvanometer control circuit p (
FIG. 5
) and is driven by a suitable DC electric source from video camera M
2
.
FIG. 6
shows a connecting device of a conventional video camera M
2
and DC control type automatic iris lens L
2
, without galvanometer control circuit p. As shown in
FIG. 6
, video camera M
2
and DC control type automatic iris lens L
2
have terminals of connectors k, k connected by a four wire cable (not shown) respectively, terminal {circle around (
1
)} of connectors k, k is connected to the positive (+) pole of braking coil CL
2
, terminal {circle around (2)}, is connected to the negative (−) pole of braking coil CL
2
, terminal {circle around (3)} is connected to the positive (+) pole of driving coil CL
1
, terminal {circle around (4)} is connected to the negative (−) pole.
Operation of this circuit is as follows; in video camera M
2
, video control signals
1
is integral amplified by driving amplifier h, changed into suitable driving DC current
2
set in variable resistor g, and drives driving coil CL
1
through terminal {circle around (3)}, {circle around (4)} of connectors k, k.
Reverse voltage generated in braking coil CL
2
is fed to video camera M
2
, through terminal {circle around (1)}{circle around (2)} as braking information.
Namely, this DC control type automatic iris lens L
2
(paragraph heading “2.” above) eliminates galvanometer control circuit p (
FIG. 5
) against 1.VS control type automatic iris lens L
1
so as to be simple in construction.
Therefore, to use this DC control type automatic iris lens L
2
(described under heading “2.” above), it is necessary to provide galvanometer control circuit p in video camera M
2
.
However in actuality, it is desired to freely use said two kinds of lenses; of a VS control type automatic iris lens L
1
(described under heading “1” above) or a DC control type automatic iris lens L, (described under heading “2.” above). And in actuality, connectors k, k used in said two kinds of VS control type automatic iris lens L, or DC control type automatic iris lens L, are the same in construction but connections are different.
FIG. 7
shows a circuit of a conventional exchangeable connecting device between video camera M
3
and automatic iris lens L
1
having galvanometer control circuit p or automatic iris lens L
2
but not having galvanometer control circuit p.
Video camera M
3
has two connectors k
1
and k
2
one is for lens L
1
and the other is for lens L
2
.
Terminal {circle around (3)} of connector k
1
for lens L
1
outputs video control signal
1
without galvanometer control circuit p. On the other hand, in connector k
2
, video control signal
1
is integral amplified by galvanometer control circuit p, changed into a suitable driving DC current
2
, having its level set by variable resistor g so as to correspond to regular video signal IVpp and terminal {circle around (3)} of connector k
2
for lens L
2
and outputs driving DC current
2
.
Therefore, the signal for controlling lens L
1
and signal for controlling lens L
2
are output from connector k
1
and connector k
2
, respectively.
However, it is necessary to change the connector according to the lens being used and this is troublesome and can cause errors.
FIG. 8
shows a circuit of conventional general video camera M
4
, provided with switch v instead of two connectors for an exchangeable connection of lens L
1
having galvanometer control circuit p or lens L
2
without galvanometer control circuit p.
Namely, video control signals
1
and driving DC current
2
of galvanometer f are switched by switch v, and fed to common connector k. Other terminals are also switched.
However, it is necessary to change switch v according to the lens being used and this is troublesome and can cause errors.
Problems to be solved by this invention.
As explained above, in a conventional device, it is necessary to confirm the lens to be used and false connections of the connector or false switching can cause errors and damage of the device.
This invention intends to eliminate said drawbacks, and an object of this invention is to provide and exchangeable connecting device between a video camera and an automatic iri
Ho Tuan
O'Reilly David
Watec Co., Ltd.
LandOfFree
Exchangeable connecting device between video camera and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Exchangeable connecting device between video camera and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Exchangeable connecting device between video camera and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3262948