CA1183940A - Solid state television camera with iris control - Google Patents
Solid state television camera with iris controlInfo
- Publication number
- CA1183940A CA1183940A CA000408789A CA408789A CA1183940A CA 1183940 A CA1183940 A CA 1183940A CA 000408789 A CA000408789 A CA 000408789A CA 408789 A CA408789 A CA 408789A CA 1183940 A CA1183940 A CA 1183940A
- Authority
- CA
- Canada
- Prior art keywords
- signal
- solid state
- output
- smear
- television camera
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/70—Circuitry for compensating brightness variation in the scene
- H04N23/75—Circuitry for compensating brightness variation in the scene by influencing optical camera components
Abstract
ABSTRACT
A solid state television camera having a solid state image sensing device, such as CCD image sensing device and an iris for control the amount of light from an image irradiated on the image sensing device. The iris is controlled by the peak level of a smear signal of a horizontal scanning line during vertical blanking interval so that the smear signal contained in a video signal from the image sensing decice is reduced. Further, the iris can be controlled by the average level of the smear signal instead of the average level of the video signal of one field as the smear signal has the whole information of the image of one field, that causes the construction of detecting circuit to be very simple and the fidelity of the iris control to be high.
A solid state television camera having a solid state image sensing device, such as CCD image sensing device and an iris for control the amount of light from an image irradiated on the image sensing device. The iris is controlled by the peak level of a smear signal of a horizontal scanning line during vertical blanking interval so that the smear signal contained in a video signal from the image sensing decice is reduced. Further, the iris can be controlled by the average level of the smear signal instead of the average level of the video signal of one field as the smear signal has the whole information of the image of one field, that causes the construction of detecting circuit to be very simple and the fidelity of the iris control to be high.
Description
~3~
_ACKGRO~ND OF THE INVENTIO
1. Field of Invention This invention relates to a television camera using asolid staie image sensor such as a CCD (charge Coupled ~evice), and particularly is directed to an iris control system for the solid state teltvision camera.
_ACKGRO~ND OF THE INVENTIO
1. Field of Invention This invention relates to a television camera using asolid staie image sensor such as a CCD (charge Coupled ~evice), and particularly is directed to an iris control system for the solid state teltvision camera.
2. Description of the Prior Art Recently, solid state imaging devices have been developed in many laboratories in accordance with the advancement of semiconductor technology. Among various types of solid state image sensors, a CCD imager is particularly interest.
There are two types of CCD imager depending on the arrangement of CCD. One is so called frame-transfer type and another is interline-transfer type. The former type of CCD imager has a image sensing array having a plurality of individual light sensing units arranged in both horizontal and vertical rows, temporary storage devices of the same number as that of the light sensing units for storing and transferring the charge accumulated in said light sensing units, and a shift register for receiving the charge sequentially Erom the storage devices and generating a signal representing the image.
In this type of CCD imager , as the light sensing units are irradiated by the light of the image during the transfer period of the charye from the image sensing array to the temporary storaye area, the undesirable charge is mixed to the transferred charge representing the image. Because of this undesirable charge, the output signal of the CCD imager includes, so called smear signal which may be a cause that the black portion of the imaye is whitish, particularly when the image has the high contrast, such as in an outside filming.
.,, --1--~3~
The interline-transfer type CCD imager also generates the smear signal though thecause of generation is different from that oE the frame transfer type CCD imager due to the difference of the arrangement of CCD. The appearance of smear is inevitable in the solid state imaging devices, and it causes the deterioration in thegenerated signal.
While, generally, a television camera has iris means in an optical system arranged in front of the light sensing device and for controlling the amount of light irradiated to the light sensing device so that the output signal has the proper level. And recently, many television cameras adopt, so colled automatic iris control for controlling the operation of the iris means by the average level of the output signal of the light sensing device. According to said existing iris control system, if the image picked up by the television camera has a small bright spot in the dark back-ground, the average level of the output signal is regarded to be relatively small, therefore the iris means is controlled so that more light should be irradiated on the light sensing divice. That causes said bright spot to be more brilliant, and then the undesirable smear signal due to the bright spot becomes large and the reproduced image from the picked up signal becomes noisy Further, the averaging circiut requires very complicated circuit construction, particulary~the picked up signal is a digital signal because the fiçld or frame memory is required for averaging the whole signal during one filcl or frame.
Finally, in the solid state light sensing device, such as a CCD imager has the limitation of the capacit~ for handling or transferring the charge, so the charge above the predetermined level is thrown away to, for example a over-flow-drain constructed in a CCD chip. In other words, the output o
There are two types of CCD imager depending on the arrangement of CCD. One is so called frame-transfer type and another is interline-transfer type. The former type of CCD imager has a image sensing array having a plurality of individual light sensing units arranged in both horizontal and vertical rows, temporary storage devices of the same number as that of the light sensing units for storing and transferring the charge accumulated in said light sensing units, and a shift register for receiving the charge sequentially Erom the storage devices and generating a signal representing the image.
In this type of CCD imager , as the light sensing units are irradiated by the light of the image during the transfer period of the charye from the image sensing array to the temporary storaye area, the undesirable charge is mixed to the transferred charge representing the image. Because of this undesirable charge, the output signal of the CCD imager includes, so called smear signal which may be a cause that the black portion of the imaye is whitish, particularly when the image has the high contrast, such as in an outside filming.
.,, --1--~3~
The interline-transfer type CCD imager also generates the smear signal though thecause of generation is different from that oE the frame transfer type CCD imager due to the difference of the arrangement of CCD. The appearance of smear is inevitable in the solid state imaging devices, and it causes the deterioration in thegenerated signal.
While, generally, a television camera has iris means in an optical system arranged in front of the light sensing device and for controlling the amount of light irradiated to the light sensing device so that the output signal has the proper level. And recently, many television cameras adopt, so colled automatic iris control for controlling the operation of the iris means by the average level of the output signal of the light sensing device. According to said existing iris control system, if the image picked up by the television camera has a small bright spot in the dark back-ground, the average level of the output signal is regarded to be relatively small, therefore the iris means is controlled so that more light should be irradiated on the light sensing divice. That causes said bright spot to be more brilliant, and then the undesirable smear signal due to the bright spot becomes large and the reproduced image from the picked up signal becomes noisy Further, the averaging circiut requires very complicated circuit construction, particulary~the picked up signal is a digital signal because the fiçld or frame memory is required for averaging the whole signal during one filcl or frame.
Finally, in the solid state light sensing device, such as a CCD imager has the limitation of the capacit~ for handling or transferring the charge, so the charge above the predetermined level is thrown away to, for example a over-flow-drain constructed in a CCD chip. In other words, the output o
3~
signal from the CCD imager is clipped to a predetermined over-flow-level if the light from the image becomes very bright.
Therefore, the picked up signal does not always represent the exact light amoun-t and the iris control by the averaged signal that may not represent the average light amount from the image is lack oE fidelity of control. And as the smear signal is generated in proportion to the radiated light amount, the above iris control does not reduce the level of the smear signal.
SIJMMERY OF THE INVENTION
. _ _ Accordingly, an object of the present invention is to provide a solid state television camera free from the defect of the prior art.
Another object of the invention is to provide a solid state television camera with an improved iris control system which can reduce the smear signal.
Futher object of the invention is to provide a solid state television camera in which the control circuit of the iris means is very simple in construction.
Still further object of the invention is to provide a solid state television camera in which the iris control operation can be performed with hig~fidelity.
According to an aspect of the invention, there is provided an improved iris control system used in a solid state television camera which generates the smear signal inevitably ,, The smear signal is detected from the output of the solicl state irnager, and the peak level of the detected smear signal controls the operation of the iris means so 3~Q
that the level of the smear signal is reduced. And as the smear signal is considered to represent the integrated signal of the image vertically in the image sensing device, the iris control by the average level of smear signal can be substitued by the existing control by the average level of the whole signal during a field or frame period.
Other objects and features of the invention will be apparent from the following description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figl is front view of a CCD imager of the frame transfer type usable in the invention.
Fig2 is a schematic diagram showing the characteristics of the pick up video signal and smear signal responsive to the input light amount radiated on the solid state imager.
Fig3 is a block diagram showing an embodiment of an iris control system according to the invention.
Fig4 is a wavefrom showing an output signal generated in a solid state imager.
Fig5 is a block diagram showing another embodiment of an iris control system according to the i~vention.
]?ig6 is a block diagram showing an embodiment of an iris control system used in a solid state color television camera with three CCD chips.
3~
D~SCRIPTION OF TEIE PREFERRED EMBODIM NTS
Referring first to Eigl which shows a CCD imager of frame tramsfer type usable in the present inventlon. The CCD
imager 5 shown in Figl has an image sensing device 1 incl~ding a plurality of individual light sensing units arranged in both hoEizontal and vertical rows, a temporary storage devices 2 and a horizontal shift register 3 for generating a video signal sequentially. Further, a synchronizing signal generator 6 for generating a horizontal synchronizing signal and a vertical synchronizing signal and a clock signal generator 7 supplied with the horizontal and vertical synchronizing signal and for generating various kinds of clock signals for controlling the operation of the image sensing device 1 temporary storage devices 2 and the horizontal shift register 3. The signal charge generated in the image sensing divice 1 is transferred vertically to the temporary storage devices 2, and the signal charge from the temporary storage devices 2 is read out line by line through the holizontal shift register 3. In this operation, during the transfer of the signal charge from, the image sensing divice 1 to the temporary storage devices 2, the light from the image is still irradiated on the image sensing device 1, so the undesirable ~harge due to the irradiated light during the transfer period is generated and it causes the smear signal in the read out video signal.
'rhe CCD imager shown in E'igl has the limitation of capacity for handlinc;or transferring the charge, so the charge above the predetermined level is thrown away to a over-flow-drain (not shown) constructed in the CCD chip. Therefore the 3~
output video signal generated in the CCD imager 5 is chipped to an over-flow level even if the light of the image is increased above the predetermined amount as shown in the broken line of Fig2. On the contrar~, the level of the smear signal increases in proportion to the amount of the light irradiated on the image sensing device 1 as shown in the so]id line of Fig2. Therefore, according to the existing iris control system for controlling the iris by the average level of the video signal obtained from the CCD imager, the smear signal contained in the video signal is not reduced and the iris control with high fidelity can not be achieved.
In Eig3 which shows an enbodiment of this invention, the output video signal from a CCD i~ager 11 is supplied to a movable tap of selecting switch 13 througha buffer amplifier 12. A first fixed tap of the switch 13 is connected to an average detector 15 and a second fixed tap of the switch 13 is connected to a peak detector 16. The selecting switch 13 is controlled by a control signal from the synchronizing signal generator 6 of Figl, the movable tap of the switch 13 is connected to the Eirst fixed tap during the vertical trace period TV as shown in Fig4 and the video signal during that period is supplied to the averaye detector 15, and the movable tap of the switch 13 is connec:ted to the second fixed tap during the vertical blanking interval T~ as shown in Fig4. The output signal from the CC~ imager during the vertical blanking interval TB does not contain the signal representing the image theoretically, accorclingly that signal can be considered as the smear signal. This smear signal during the vertical 3~
blanking interval TB is supplied to the peak detector 16 through an amplifier 1~ which is privided because the level of the smear signal is low compared with that of video signal during the vertical trace period Tv and the smear signal must be amplified to be the comparable level with the video signal.
The detected outputs of the detectors 15 and 16 are supplied to a mixer 17 for generating a control signal of an iris driver 18 for an iris 19 disposed in front of the CCD imager 11. The mixer includes a cornparator 17a for comparing the output of the peak detector 16 with a reference level forming a threshold level, a gate circuit 17b controlled by the output of the comparator 17a and passing the output of the detector 16 when the level of the peak detected output is higher than the threshold, and an adder 17c for adding the output of the average detector 15 and the gate circuit 17b with an appropriate ratio Therefore the iris 19 is controlled by only -the average :level of the video signal when the level of the smear signal is relatively small and the smear signal cloes not disturb the video signal representing the image remarkably.
But when the level of the smear signal is higher than the threshold level and the smear signal gives a bad influence to the video signal, the iris 19 is controlled by the synthe-sized outputs oE both the average detector 15 and the peak detector 16.
Here, the smear signal oE one horizontal period in the verti.cal blanking interval TB is in proporation to the integrated signal of the video signal representing the whole image vertically in the CCD imager ancl the signal ~3~
of each horizontal period in the vertical blanking interval TB is quite similar with each other, so the smear signal of any one horizontal period can be regarded to have all information of the light amount during one field. Therefore the peak detector 16 can he designed to detect the peak level of the signal of only one holizontal period in the vertical blanking interval TB. According to the embodiment of Fig3 and explained above, the iris control for reducing the level of the smear signal when it is remarkcably large can berealized because both the average level of the video signal and the peak level of the smear signal are used as a control signal of iris 19.
Fig5 shows a second embodiment of the invention wherein the only smear signal is supplied to both peak and average detectors in parallel and the control signal for iris 19 is generated from only the smear signal while both the smear signal and video signal are used for generating a control signal for iris in the embodiment of Fig3.
In Fig5, the output signal of the bu~fer amplifier 12 is supplied to a smear signal gating switch 23 which is turned on during one horizontal period of the vertival blanking interval 1'g, and the smear signal during this period is gated and supplied to both the average detector 15 ~nd the peak det:ector 16. The outputs of these d~tectors are mixed by the mixer 17 which can be constructed same as that in E'ig3, and the output of the mixer 17 controls the iris driver 18 for the iris 19. In this embodiment, as the smear signal during one horizontal period of the vertical blanking interval has the all information of the light of the image during one field period as explained above, the same effect as in the embodiment of Fig3 wherein the video signal of one Eiled period is detected by the average detector can be achieved. And, particularly when the output signal from the CCD imager is a digital video signal, the average detector 15 can be very simple in construction in this embodiment, while in the embodiment of Fig3 or in the existing iris control system, the field mernory for memorizing the digital video information of one fie~d is required to obtain the average level of the video signal during one field.
The third embodiment in which the present invention is applied to a solid state color television camera will be explained hereinafter with reference to Fig6. The solid state color teLevision camera in Fig6 has three chips of solid state image sensors llG for green, llR for red and llB for blue Three primary color sigr.als obtained from image sensors llG, llR and llB are fed to output terminals 20G, 20R and through amplifiers 12G 12R and 12B for the adjustment of the white balance. The iris 19 common to three solid state imagesensors llG llR and llB Eor adjusting the amount of light irradiated on each image sensor is controlled by the level of smear signal of One horizontal period in the vertical blanking interval TB. That is, the output signals oE the amplifiers 12G,12R and~l2B are supplied to a non-adder mixer 30 which generates an output signal e~ual to the highest level oE the input signals or operates as a signal selector for selecting a signal with the highest level. The smear signal of one horizontal period in the vertical blanking interval TB contained in the output of the non-adder mixer 30 is gated by a gating switch 23 and ~3s~
is supplied to the detectors 15 and 16. The avera~e level and the peak level of the smear signal detected by detectors lS and 16 are supplied to the mixer 17, and the output of the mixer 17 is supplied to the iris dri~er 18 for the iris 19 as a control signal. The mixer 17 may be constructed as shown in Fig3.
As explained above with reference to various embodiments, the deteriorations in the picture quality can be reduced and the iris control with the higher fidelity can be attained with a simple circuit construction as the iris is controlled and the level of the signal is controlled by the smear signal in the vertical blanking interval obtained from the solid state image sensor.
It will be apparent that many modifications and variations may be effected without departing frorn the scope of the novel concepts of this invention.
signal from the CCD imager is clipped to a predetermined over-flow-level if the light from the image becomes very bright.
Therefore, the picked up signal does not always represent the exact light amoun-t and the iris control by the averaged signal that may not represent the average light amount from the image is lack oE fidelity of control. And as the smear signal is generated in proportion to the radiated light amount, the above iris control does not reduce the level of the smear signal.
SIJMMERY OF THE INVENTION
. _ _ Accordingly, an object of the present invention is to provide a solid state television camera free from the defect of the prior art.
Another object of the invention is to provide a solid state television camera with an improved iris control system which can reduce the smear signal.
Futher object of the invention is to provide a solid state television camera in which the control circuit of the iris means is very simple in construction.
Still further object of the invention is to provide a solid state television camera in which the iris control operation can be performed with hig~fidelity.
According to an aspect of the invention, there is provided an improved iris control system used in a solid state television camera which generates the smear signal inevitably ,, The smear signal is detected from the output of the solicl state irnager, and the peak level of the detected smear signal controls the operation of the iris means so 3~Q
that the level of the smear signal is reduced. And as the smear signal is considered to represent the integrated signal of the image vertically in the image sensing device, the iris control by the average level of smear signal can be substitued by the existing control by the average level of the whole signal during a field or frame period.
Other objects and features of the invention will be apparent from the following description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figl is front view of a CCD imager of the frame transfer type usable in the invention.
Fig2 is a schematic diagram showing the characteristics of the pick up video signal and smear signal responsive to the input light amount radiated on the solid state imager.
Fig3 is a block diagram showing an embodiment of an iris control system according to the invention.
Fig4 is a wavefrom showing an output signal generated in a solid state imager.
Fig5 is a block diagram showing another embodiment of an iris control system according to the i~vention.
]?ig6 is a block diagram showing an embodiment of an iris control system used in a solid state color television camera with three CCD chips.
3~
D~SCRIPTION OF TEIE PREFERRED EMBODIM NTS
Referring first to Eigl which shows a CCD imager of frame tramsfer type usable in the present inventlon. The CCD
imager 5 shown in Figl has an image sensing device 1 incl~ding a plurality of individual light sensing units arranged in both hoEizontal and vertical rows, a temporary storage devices 2 and a horizontal shift register 3 for generating a video signal sequentially. Further, a synchronizing signal generator 6 for generating a horizontal synchronizing signal and a vertical synchronizing signal and a clock signal generator 7 supplied with the horizontal and vertical synchronizing signal and for generating various kinds of clock signals for controlling the operation of the image sensing device 1 temporary storage devices 2 and the horizontal shift register 3. The signal charge generated in the image sensing divice 1 is transferred vertically to the temporary storage devices 2, and the signal charge from the temporary storage devices 2 is read out line by line through the holizontal shift register 3. In this operation, during the transfer of the signal charge from, the image sensing divice 1 to the temporary storage devices 2, the light from the image is still irradiated on the image sensing device 1, so the undesirable ~harge due to the irradiated light during the transfer period is generated and it causes the smear signal in the read out video signal.
'rhe CCD imager shown in E'igl has the limitation of capacity for handlinc;or transferring the charge, so the charge above the predetermined level is thrown away to a over-flow-drain (not shown) constructed in the CCD chip. Therefore the 3~
output video signal generated in the CCD imager 5 is chipped to an over-flow level even if the light of the image is increased above the predetermined amount as shown in the broken line of Fig2. On the contrar~, the level of the smear signal increases in proportion to the amount of the light irradiated on the image sensing device 1 as shown in the so]id line of Fig2. Therefore, according to the existing iris control system for controlling the iris by the average level of the video signal obtained from the CCD imager, the smear signal contained in the video signal is not reduced and the iris control with high fidelity can not be achieved.
In Eig3 which shows an enbodiment of this invention, the output video signal from a CCD i~ager 11 is supplied to a movable tap of selecting switch 13 througha buffer amplifier 12. A first fixed tap of the switch 13 is connected to an average detector 15 and a second fixed tap of the switch 13 is connected to a peak detector 16. The selecting switch 13 is controlled by a control signal from the synchronizing signal generator 6 of Figl, the movable tap of the switch 13 is connected to the Eirst fixed tap during the vertical trace period TV as shown in Fig4 and the video signal during that period is supplied to the averaye detector 15, and the movable tap of the switch 13 is connec:ted to the second fixed tap during the vertical blanking interval T~ as shown in Fig4. The output signal from the CC~ imager during the vertical blanking interval TB does not contain the signal representing the image theoretically, accorclingly that signal can be considered as the smear signal. This smear signal during the vertical 3~
blanking interval TB is supplied to the peak detector 16 through an amplifier 1~ which is privided because the level of the smear signal is low compared with that of video signal during the vertical trace period Tv and the smear signal must be amplified to be the comparable level with the video signal.
The detected outputs of the detectors 15 and 16 are supplied to a mixer 17 for generating a control signal of an iris driver 18 for an iris 19 disposed in front of the CCD imager 11. The mixer includes a cornparator 17a for comparing the output of the peak detector 16 with a reference level forming a threshold level, a gate circuit 17b controlled by the output of the comparator 17a and passing the output of the detector 16 when the level of the peak detected output is higher than the threshold, and an adder 17c for adding the output of the average detector 15 and the gate circuit 17b with an appropriate ratio Therefore the iris 19 is controlled by only -the average :level of the video signal when the level of the smear signal is relatively small and the smear signal cloes not disturb the video signal representing the image remarkably.
But when the level of the smear signal is higher than the threshold level and the smear signal gives a bad influence to the video signal, the iris 19 is controlled by the synthe-sized outputs oE both the average detector 15 and the peak detector 16.
Here, the smear signal oE one horizontal period in the verti.cal blanking interval TB is in proporation to the integrated signal of the video signal representing the whole image vertically in the CCD imager ancl the signal ~3~
of each horizontal period in the vertical blanking interval TB is quite similar with each other, so the smear signal of any one horizontal period can be regarded to have all information of the light amount during one field. Therefore the peak detector 16 can he designed to detect the peak level of the signal of only one holizontal period in the vertical blanking interval TB. According to the embodiment of Fig3 and explained above, the iris control for reducing the level of the smear signal when it is remarkcably large can berealized because both the average level of the video signal and the peak level of the smear signal are used as a control signal of iris 19.
Fig5 shows a second embodiment of the invention wherein the only smear signal is supplied to both peak and average detectors in parallel and the control signal for iris 19 is generated from only the smear signal while both the smear signal and video signal are used for generating a control signal for iris in the embodiment of Fig3.
In Fig5, the output signal of the bu~fer amplifier 12 is supplied to a smear signal gating switch 23 which is turned on during one horizontal period of the vertival blanking interval 1'g, and the smear signal during this period is gated and supplied to both the average detector 15 ~nd the peak det:ector 16. The outputs of these d~tectors are mixed by the mixer 17 which can be constructed same as that in E'ig3, and the output of the mixer 17 controls the iris driver 18 for the iris 19. In this embodiment, as the smear signal during one horizontal period of the vertical blanking interval has the all information of the light of the image during one field period as explained above, the same effect as in the embodiment of Fig3 wherein the video signal of one Eiled period is detected by the average detector can be achieved. And, particularly when the output signal from the CCD imager is a digital video signal, the average detector 15 can be very simple in construction in this embodiment, while in the embodiment of Fig3 or in the existing iris control system, the field mernory for memorizing the digital video information of one fie~d is required to obtain the average level of the video signal during one field.
The third embodiment in which the present invention is applied to a solid state color television camera will be explained hereinafter with reference to Fig6. The solid state color teLevision camera in Fig6 has three chips of solid state image sensors llG for green, llR for red and llB for blue Three primary color sigr.als obtained from image sensors llG, llR and llB are fed to output terminals 20G, 20R and through amplifiers 12G 12R and 12B for the adjustment of the white balance. The iris 19 common to three solid state imagesensors llG llR and llB Eor adjusting the amount of light irradiated on each image sensor is controlled by the level of smear signal of One horizontal period in the vertical blanking interval TB. That is, the output signals oE the amplifiers 12G,12R and~l2B are supplied to a non-adder mixer 30 which generates an output signal e~ual to the highest level oE the input signals or operates as a signal selector for selecting a signal with the highest level. The smear signal of one horizontal period in the vertical blanking interval TB contained in the output of the non-adder mixer 30 is gated by a gating switch 23 and ~3s~
is supplied to the detectors 15 and 16. The avera~e level and the peak level of the smear signal detected by detectors lS and 16 are supplied to the mixer 17, and the output of the mixer 17 is supplied to the iris dri~er 18 for the iris 19 as a control signal. The mixer 17 may be constructed as shown in Fig3.
As explained above with reference to various embodiments, the deteriorations in the picture quality can be reduced and the iris control with the higher fidelity can be attained with a simple circuit construction as the iris is controlled and the level of the signal is controlled by the smear signal in the vertical blanking interval obtained from the solid state image sensor.
It will be apparent that many modifications and variations may be effected without departing frorn the scope of the novel concepts of this invention.
Claims (7)
1. A solid state television camera having a solid state image sensing divice including a plurality of individual light sensing units arranged in both horizontal and vertical rows and for sequentially generating a signal corresponding to an image by transferring a charge generated by said light sensing units, said solid state television camera comprising, (A) a synchronizing signal generator for generating horizontal and vertical synchronizing signals, (B) a clock pulse generator controlled by said synchronizing signals and for generating various kinds of clock pulses controlling the transfer of the charge generated in said light sensing units, (C) iris means for controlling the light amount from the image radiated on said light sensing units, (D) driver means for controlling said iris means, (E) smear signal detecting means for detecting a smear signal from the output signal of said solid state image sensing device, and (f) means for supplying the output of said smear signal detecting means to said drive means such that the light amount is controlled by the level of said smear signal.
2. A solid state television camera according to claim 1, wherein said smear signal detecting means includes a detecting circuit for detecting a signal during a horizontal period in a vertical blanking period thereby the detected output representing the smear signal.
3. A solid state television camera according to claim 1, wherein said means for supplying includes a peak detector for detecting the peak level of said smear sagnal.
4. A solid state television camera according to claim 3, wherein said means for supplying further includes an average detector for detecting an average level of the output signal of said solid state image sensing device and a mixer for mixing the outputs of said peak detector and average detector.
5. A solid state television camera according to claim 4, wherein said mixer generates an output responsive to only the output of said average detector when the output of said peak detector is less than a threshold level and said mixer generates an output responsive to both the outputs of said average and peak detectors when the output of said peak detector is above said threshold level.
6. A solid state television camera according to claim 3, wherein said means for supplying further includes an average detector for detecting an average level of said smear signal and a mixer for mixing the outputs of said peak and average detectors.
7. A solid state television camera according to claim 1, wherein said television camera comprises three solid state image sensing devices for three primary colored lights for generating tree output signals representing the each color component of the image, respectively, said iris means is common to said three solid state image sensing devices, and said smear signal detecting means includes a non-adder mixer for generating the output equal to the maximum level of three smear signals of said three output signals.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP125062/81 | 1981-08-10 | ||
| JP56125062A JPS5827472A (en) | 1981-08-10 | 1981-08-10 | Controller for solid-state image pickup device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1183940A true CA1183940A (en) | 1985-03-12 |
Family
ID=14900870
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000408789A Expired CA1183940A (en) | 1981-08-10 | 1982-08-05 | Solid state television camera with iris control |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US4516172A (en) |
| JP (1) | JPS5827472A (en) |
| AT (1) | AT390343B (en) |
| CA (1) | CA1183940A (en) |
| DE (1) | DE3229771A1 (en) |
| FR (1) | FR2511213B1 (en) |
| GB (1) | GB2106740B (en) |
| NL (1) | NL8203154A (en) |
Families Citing this family (28)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB8219853D0 (en) * | 1982-07-14 | 1995-04-12 | British Aerospace | Image sensing |
| JPS5981992A (en) * | 1982-11-02 | 1984-05-11 | Canon Inc | Color image pickup device |
| GB2151430A (en) * | 1983-11-30 | 1985-07-17 | Hitachi Ltd | Solid-state imaging system with smear suppression circuits |
| US4599654A (en) * | 1984-10-31 | 1986-07-08 | Rca Corporation | Dark current eliminator useful for auto-iris controller |
| US4748506A (en) * | 1984-12-28 | 1988-05-31 | Canon Kabushiki Kaisha | Image pickup apparatus with excess-charge control |
| FR2577669B1 (en) * | 1985-02-21 | 1992-05-15 | Fuji Photo Film Co Ltd | IMAGE READING METHOD AND APPARATUS |
| DE3509825A1 (en) * | 1985-03-19 | 1986-09-25 | Richard Wolf Gmbh, 7134 Knittlingen | LIGHT PROJECTOR WITH ADJUSTABLE ILLUMINATION |
| US4598322A (en) * | 1985-05-13 | 1986-07-01 | Honeywell Inc. | Video level control for CCD camera |
| NL8501635A (en) * | 1985-06-06 | 1987-01-02 | Philips Nv | CAMERA FOR TELEVISION, PHOTOGRAPH AND FILM RECORDING. |
| US4670787A (en) * | 1985-07-31 | 1987-06-02 | Rca Corporation | Suppression of field-rate brightness variations for a television camera |
| FR2586151B1 (en) * | 1985-08-06 | 1988-07-15 | Thomson Csf | AUTOMATIC ILLUMINATION ADJUSTMENT DEVICE FOR TELEVISION SHOOTING SYSTEMS |
| US4843476A (en) * | 1986-11-25 | 1989-06-27 | Matsushita Electric Industrial Co., Ltd. | System for controlling the amount of light reaching an image pick-up apparatus based on a brightness/darkness ratio weighing |
| JPH0789178B2 (en) * | 1986-12-19 | 1995-09-27 | オリンパス光学工業株式会社 | Automatic light control device for endoscopes using an external camera |
| JPH07114474B2 (en) * | 1987-01-05 | 1995-12-06 | 株式会社東芝 | Electronic still camera |
| US4908709A (en) * | 1987-12-11 | 1990-03-13 | Fuji Photo Film Co., Ltd. | Solid-state electronic imaging device with a photometry function responsive to discarded charge packets |
| AU607033B2 (en) * | 1988-01-12 | 1991-02-21 | Sanyo Electric Co., Ltd. | Auto iris/gamma correction apparatus for making automatic exposure adjustment and/or automatic gamma correction in response to video signal and image sensing apparatus comprising such auto iris/gamma correction apparatus |
| KR910008286Y1 (en) * | 1988-07-12 | 1991-10-15 | 삼성전자 주식회사 | Auto-exposure control circuit of video camera |
| KR920000575B1 (en) * | 1988-11-03 | 1992-01-16 | 삼성전관 주식회사 | Solid-state image device |
| US5282041A (en) * | 1988-12-15 | 1994-01-25 | Asahi Kogaku Kogyo Kabushiki Kaisha | Apparatus for driving image pick-up device |
| JPH02288686A (en) * | 1989-04-28 | 1990-11-28 | Toshiba Corp | Solid-state image pickup device |
| JPH031772A (en) * | 1989-05-30 | 1991-01-08 | Sony Corp | Image pickup device |
| US5111301A (en) * | 1989-06-28 | 1992-05-05 | Sanyo Electric Co., Ltd. | Automatic exposure adjusting apparatus for automatically adjusting exposure by fuzzy inference |
| DE69033646T2 (en) * | 1989-07-18 | 2001-02-22 | Fuji Photo Film Co Ltd | Method and device for controlling the exposure changes of a video camera |
| US5341220A (en) * | 1990-01-08 | 1994-08-23 | Nikon Corporation | Still picture imaging apparatus having an improved automatic exposure control and reduction in power consumption |
| JPH04373277A (en) * | 1991-06-21 | 1992-12-25 | Sony Corp | Smear correcting circuit |
| JP3207313B2 (en) * | 1992-12-22 | 2001-09-10 | 富士写真フイルム株式会社 | Imaging device and control method thereof |
| US6674475B1 (en) * | 1999-08-09 | 2004-01-06 | Agilent Technologies, Inc. | Method and circuit for electronic shutter control |
| EP1942659A1 (en) * | 2006-12-12 | 2008-07-09 | Axis AB | Improved method for capturing image data |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3767853A (en) * | 1972-09-21 | 1973-10-23 | S Bendell | Automatic iris control |
| JPS5911308B2 (en) * | 1975-10-31 | 1984-03-14 | ソニー株式会社 | Color Kotai Satsuzou Sochi |
| JPS54126425A (en) * | 1978-03-25 | 1979-10-01 | Sony Corp | Automatic aperture control device of color camera unit |
| US4366501A (en) * | 1978-04-23 | 1982-12-28 | Canon Kabushiki Kaisha | Image recording system |
| JPS55163950A (en) * | 1979-06-08 | 1980-12-20 | Nec Corp | Automatic aperture control method of solid-state pickup unit |
| JPS5710583A (en) * | 1980-06-23 | 1982-01-20 | Nec Corp | Automatic diaphragm control method of solidstate image pickup device |
| US4399466A (en) * | 1981-12-24 | 1983-08-16 | Calspan Corporation | Dark current compensating lens iris control |
-
1981
- 1981-08-10 JP JP56125062A patent/JPS5827472A/en active Pending
-
1982
- 1982-08-03 GB GB08222405A patent/GB2106740B/en not_active Expired
- 1982-08-05 CA CA000408789A patent/CA1183940A/en not_active Expired
- 1982-08-05 US US06/405,571 patent/US4516172A/en not_active Expired - Fee Related
- 1982-08-10 AT AT0305782A patent/AT390343B/en not_active IP Right Cessation
- 1982-08-10 FR FR8213933A patent/FR2511213B1/en not_active Expired
- 1982-08-10 NL NL8203154A patent/NL8203154A/en not_active Application Discontinuation
- 1982-08-10 DE DE19823229771 patent/DE3229771A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| GB2106740A (en) | 1983-04-13 |
| AT390343B (en) | 1990-04-25 |
| FR2511213A1 (en) | 1983-02-11 |
| JPS5827472A (en) | 1983-02-18 |
| GB2106740B (en) | 1985-02-13 |
| DE3229771C2 (en) | 1991-01-31 |
| ATA305782A (en) | 1989-09-15 |
| DE3229771A1 (en) | 1983-02-24 |
| US4516172A (en) | 1985-05-07 |
| FR2511213B1 (en) | 1987-03-06 |
| NL8203154A (en) | 1983-03-01 |
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