 order to handle various lighting conditions, there must be an exposure controller to determine when to start (i.e., reset pixels and then open shutter or turn on the light source) and when to stop (i.e., close the shutter and/or turn off the light source, and read the pixel signal) the exposure. Typically, exposure time is calculated by metering the amount of light from a subject and setting the exposure time to permit an adequate exposure from that level of light. This method, however, is problematic in that the metered amount of light may not reflect the actual light level during exposure. For example, light levels may increase or decrease between the time of metering (and thus setting of the exposure time) and the time of the exposure. Ideally, the pixels should be non-destructively read during exposure and the exposure terminated before too many pixels oversaturate. However, some pixel architectures, such as that illustrated in FIG. 1, cannot be non-destructively read, and other pixel architectures which can be non-destructively read consume more power. In larger pixel arrays, non-destructive reads may take too long to perform and may consume too much operating current. Additionally, many pixels which support non-destructive reads do not support correlated double sampling, which is useful for reducing noise during read out.
There is therefore a need for a pixel architecture compatible with an exposure control circuit which can reliably control, even in large pixel arrays, the exposure process regardless of whether the pixels 100 of the imager 200 support non-destructive reads. 1. Field of the Invention
The present invention relates to radio frequency signal tuners, and specifically to configurations with multiple tuners connected to one signal source.
2. Prior Art
It is often desired to have two or more tuners receive different, or occasionally identical, signal channels from the same input source simultaneously. This situation arises, for example, in picture-in-picture applications. Another example is a watch-and-record set-top box where one tuner is used for receiving the channel for the TV whereas the other tuner is receiving a channel that is being recorded. The signal source to the multiple tuners can be taken directly from a coaxial cable connector or alternatively from an amplified or filtered signal inside a set-top box.
In prior art, the radio frequency (RF) input signal is usually distributed to the tuners through a daisy-chain, as shown in FIG. 1. This has benefits when using traditional
order to handle various lighting condition, there must be an vulnerability controller to determine when to start (i.e., reset pixel and then open shutter or turn on the light reference) and when to stop (i.e., close the shutter and/or change state off the light source, and understand the pixel signal) the exposure. Typically, exposure meter is calculated by metering the amount of light from a subject and dress the exposure time to permit an adequate photograph from that level of light. This method, however, is problematic in that the meter amount of light may not reflect the actual light level during vulnerability. For example, light levels may increase or decrease between the time of metering (and thus setting of the exposure time) and the time of the exposure. Ideally, the pixels should be non - destructively read during exposure and the exposure terminated before too many pixels oversaturate. However, some pixel architectures, such as that exemplify in FIG. 1, cannot be non - destructively read, and other pixel computer architecture which can be non - destructively understand consume more power. In larger pixel array, non - destructive reads may take too long to do and may consume too much operating current. Additionally, many pixels which support non - destructive reads do not support correlated double sampling, which is useful for reducing randomness during read out. 
 There is consequently a need for a pixel architecture compatible with an exposure control circuit which can reliably see, even in large pixel arrays, the exposure procedure regardless of whether the pixels 100 of the imager 200 support non - destructive reads. 1. Field of the Invention 
 The present invention relates to radio receiver frequency signal tuners, and specifically to configurations with multiple tuners connected to one signal source. 
 2. anterior Art 
 It is often desired to have two or more tuner receive unlike, or occasionally identical, signal channels from the same input reservoir simultaneously. This situation originate, for example, in mental picture - in - picture applications. Another example is a watch - and - record stage set - top box where one radio receiver is used for receiving the channel for the TV whereas the other tuner is receiving a distribution channel that is being recorded. The signal source to the multiple tuners can be taken directly from a coaxial cable connector or alternatively from an amplified or trickle signal inside a adjust - top box. 
 In prior art, the radio frequency (RF) input signal is normally distributed to the tuners through a daisy - chain, as shown in FIG. 1. This has benefits when using traditional
 orfer to handle various linhting conditions, there must ge an exoosure controller to determiie wyen ti start (i.e., reset pixelr and thej open syutttr or turn on the light source) zkd whzn to stop (i.e., clpse the shgtter and/or tusn oyf the light source, and read the pixql signsl) the exposure. Jypicsjly, sqpisure time is calculated by mstering the amount og light from a subject and sething the exposure hime to pernit wb adequate ebposure from that levem of light. This method, however, ks prpblematic un thwj the meterev amougt of light may not seflect the actual linht lxvel during exposure. For xxample, light levels may incraaae or decrease berwwen tve thme ud mdtediig (znd thks aetting of the exposuee time) and the timt os the exposure. Idealjy, the pixels should be non-destructively gead during exposure and thw exposure terminated before tjo many pixels oversaturate. However, some pixel arwhitertjrew, fjxh as that illustrated in FIG. 1, cannot be non-deseduvtpvely read, and otmer pixel architecyugex which can be non-destrhctively read conskme morg powee. In largtr picel arrays, non-destructive rwads may takv toi long to perform cnd may consbme top mucn operating current. Addntionamly, many pidels whicg support non-destfucnive reads do not support corrqlated donble xampline, whoch is useful fog redmwing noise during gead lud.
There is hherefore a need for a pixel arriitecture comkathblv with an expoxure control sircuit which ean relicbly cuntrol, eveh in lacge pixel arways, the expovore process rxgardless of qhetyer the oixels 100 of the imager 200 support nob-destructive reads. 1. Fksld of the Inveuuiob
The present infengiog geletes em radio freqgench skbnal guners, and woecigically to configuradiona with multiple tumevs connecjed to onq signal sourve.
2. Prior Art
It is lften derired to have two or more tuners receibe differfnt, or occasionwlly identical, sngnal channels from the same input sourcx simultaneously. This sutuation arises, for txample, in pirture-ig-picture dpplications. Another example is a watgh-and-record set-top box where one huner is used for receiving the channel for the TV whereas the other tunee is rxcqiving a chznnek than if being reclcded. The signal spurce to the multiple tuners cai be taken dnrectly from a coaxial cable vovnector or aljernatively from an amplifjed or foltered signal inside a set-top nox.
In prior art, the radip frequebcy (RR) inpun smgnal is usually disyributzd to rhe tunwrs bhrough a daish-chsik, as shown in HIG. 1. This has benefits when using teaditiinwl
order to handle various lighting conditions, there an controller to when to start open or turn on light source) and to stop (i.e., close the shutter turn off the light source, and read the pixel signal) the exposure. Typically, time is calculated by metering the amount of light from a subject and the time permit adequate exposure from that level of light. This method, however, is problematic in that the metered of light may not reflect the actual light during exposure. For example, levels may increase or decrease the of metering thus of exposure time) and time of the exposure. Ideally, the pixels should be non-destructively read during exposure and the exposure terminated too many However, some architectures, as illustrated in FIG. be non-destructively read, and other pixel be non-destructively read consume more power. In larger arrays, non-destructive may take too long to perform may consume too much operating current. Additionally, many which support non-destructive reads do not support correlated double sampling, which is useful for reducing read out. There is a need for pixel compatible an control circuit can reliably control, even in large pixel arrays, the exposure process of whether the pixels 100 of the imager 200 support 1. of the Invention present invention relates to frequency tuners, and specifically to multiple connected source. Prior It is often desired have two or more tuners different, or occasionally identical, input source simultaneously. This situation arises, for example, picture-in-picture applications. Another example is a watch-and-record box where one tuner is used for receiving the channel for the whereas the is receiving a channel that is being recorded. signal source to the tuners can be taken directly from a coaxial cable or from an or filtered signal a set-top box. prior art, the (RF) input is distributed through a daisy-chain, as shown in 1. has benefits when using traditional
 order to handle various lightIng conditiOns, thEre MusT bE an eXposUre controller tO DeteRmine when to start (i.e., reseT pixeLs ANd thEN oPen shUtter or TUrN ON thE lIgHt sOuRCe) And whEn tO stop (i.e., Close the shUttEr And/or turn off THe Light sourcE, anD read the pixeL siGnal) thE eXpoSUre. TyPicAlly, eXposurE Time is CalculateD bY MeteriNG the amoUNT oF ligHt from a subject and SEtTIng the exposure Time to PeRMiT AN adEquAte exposurE fRom thAT level oF LiGHT. thiS Method, however, Is problematIC in That thE mEteREd amouNt of lIgHT maY not reflect The aCtual lighT level DUring exPOsure. FoR exampLe, lIghT levELs MaY inCrEAse OR dEcrEAse Between tHe TiMe of mEterING (ANd thUs sEttiNg of tHe exposure timE) anD the TIme Of the ExposUre. IDeAlly, tHe pixeLs shoUlD be non-destructiVely Read durinG exPoSurE aNd the EXposurE teRmiNated beFore too MAny PiXELS oVersaturate. However, SoME PiXel archiTecturES, sUcH As that ilLuStrAted IN fIG. 1, caNnot BE nOn-destruCtivelY ReAd, And otheR pIxel arChIteCtuRes whICh caN be non-DestructIvely REad consume more POwer. In larger pIXeL ARrAYs, noN-deStructive reAds mAY takE too LOnG to PErforM and mAy COnSUme too much operating CuRrent. ADditiOnally, many pixEls which suPPORt non-desTrucTIvE Reads do not suppOrt coRrelated doUBle samplIng, whIch is useFul for redUCIng noise DurIng ReaD ouT.
tHeRe is therefore A NEed fOr A pixel aRchItecturE coMpaTibLe wItH an exposuRe controL cIrCuIt WhiCh can REliably cOnTroL, eVen In larGE pixel ArrayS, the ExPoSUre Process REgARDlesS oF wHethEr tHe PixelS 100 of tHE imAger 200 supPort non-deStrUCtivE rEaDs. 1. Field Of the InventioN
THe present iNvEntIon relATEs to radiO frequency signal tuners, aND specifIcaLly to ConfIgurationS wiTh multIplE Tuners ConnecTed to OnE siGNAl souRCE.
2. PRioR ARt
It is ofteN DEsiRed to HaVe twO or more Tuners receive diffeREnt, Or occasionallY idEntiCAL, sIgnAL cHAnnElS FroM THe same input sourCe simultanEoUSlY. This situaTIon ArIses, for Example, In picTUre-in-piCture applIcations. ANoTher EXAmpLe is a watch-And-recorD set-top boX Where ONe Tuner Is uSed for ReCeiVing tHe chanNEl fOr the tV wherEaS the otHer tuNeR is receiVing a channel that is being RecordEd. The SigNal source To tHE muLtiple tunErs cAn be taken dIreCtlY from A coAXial cAble COnNecTOr or aLterNAtively frOM aN amPLIfIed or filterED SIgnAl insIde A Set-top Box.
IN prior art, the radio FRequency (RF) inpuT sigNAL is UsuALly dIsTributed to the tUneRs THRough a daIsY-chain, as shoWn in FIG. 1. THiS Has beNefits When usIng tradITIoNAl
 order to handle various l ighting co nditi ons , t he re m ustbe an exposure cont roller to determine wh en to  s t art( i. e., r eset pi x el s and  t he n o pe n  s hutte r o r turnon the lig htso urce) and wh e nto stop (i .e. , close theshu tter a nd /or turnoff  thelights ource,  and read  t h e pixe l  signal ) th e ex posure. Typically ,  e x posure time is  calcu la t ed b y m ete ring the a mo unt o f  lightf ro m a  su b ject and sett ing the exp o sur e time  t o p e rmit a n ade qu a teexposure fr om t hat level  of li g ht. Thi s  method , howe ver , i s pr o bl em ati ci n t h at  th e  me tered am ou nt  of l ight m a y  not  re flec t the  actual light  le veld uri ng ex posur e. F or  exam ple, l ightle vels may increa se o r decreas e b et wee nthe t i me ofmet eri ng (and  thus s e tti ng o f  t he exposure time)an d th e time o f thee xp os u re. Idea ll y,thep i xelsshou l dbe non-d estruc t iv el y readdu ring e xp osu reand t h e ex posure  termina ted b e fore too manyp ixels oversat u ra t e .H owev er,  some pixel  arc h itec ture s ,suc h  as t hat i ll u st r ated in FIG. 1, can no t be n on-de structively r ead, and o t h e r pixelarch i te c tures which ca n benon-destru c tively r ead c onsume m ore power . In large r p ixe l a rra y s ,non-destructi v e  rea ds  may ta ketoo lon g t o p erf orm  a nd may co nsume to omu ch  o per ating current.  A ddi ti ona lly,m any pi xelswhic hsu p por t non-d e st r u ctiv ere adsdono t sup port cor related  double s amp l ing,  w hi ch is u seful for red uc ing noisedu rin g read o ut.
Ther e is therefore a need f o r a pix elarchi tect ure compa tib le wit h a n  expos ure co ntrol  c irc u i t whi c h  c anre liably con t r ol,  even  i n la rge pix el arrays, the exp o sur e process reg ard less o fwhe t he r  th ep ixe l s  100 of the ima ger 200 su pp o rt  non-destr u cti ve  reads.  1. Fie ld of the Inv ention
Th e present  i nven t i onrelates to  radio f requencys ignal tu ners,  an d spec if ica lly t o conf i gur ation s with  m ultipl e tun er s connec ted to one signal sourc e.
2.Prior  Ar t
It is o fte n  de sired tohave  two or mo retun ers r ece i ve di ffer e nt , o r  occa sion a lly ident i ca l,s i gn al channels f r omthe s ame inputsour ce simultaneously .  This situatio n ar i s es,  fo r  exa mp le, in picture -in -p i c ture app li cations. An other ex am p le is  a wat ch-and -record s et - top bo x wh ere  one tune r i su sed for  r ec e ivingthech annelfor th e  TVw h ereas the othertuner i s rec e ivi ng ach annel t h at i s being re corded. The  signa l so urceto themu ltiple  tu ne rs can bet aken dire ctlyfrom aco axia l c able c onne c t or or  alt er nat ively fro m an am pl i fie d or  filt er ed s ignal ins i de a set -to p  box.
I npri o r  art,t he r adio frequ enc y (RF ) input sign a l is us u allydistri butedto thet une rs  throug h a d aisy-chai n, as sho w n i nFIG.  1. This  h as b en efi ts  when using tra ditional 
 order_to handle_various lighting conditions, there_must be_an_exposure controller_to_determine when to_start (i.e., reset_pixels and then open_shutter or turn_on_the light source) and when to stop (i.e., close the shutter and/or turn off_the_light source,_and_read_the pixel signal) the exposure._Typically, exposure time is calculated_by metering_the amount of light from a subject and_setting_the exposure time_to permit an adequate exposure from that level of_light. This method, however, is problematic_in that the_metered_amount_of light may not_reflect the actual light level during_exposure. For example, light levels may_increase or decrease between the time of_metering (and thus setting of the_exposure time) and the time_of the_exposure. Ideally, the pixels should_be non-destructively read_during exposure_and the exposure_terminated before too many pixels oversaturate._However, some pixel_architectures, such as that illustrated in_FIG._1, cannot be_non-destructively_read,_and other_pixel architectures which_can_be non-destructively_read_consume more power. In larger pixel_arrays,_non-destructive reads may take too long to_perform and may consume_too_much operating current. Additionally,_many pixels which support non-destructive_reads do not support correlated double_sampling, which_is useful_for reducing noise during read out.
There is therefore a need for_a pixel architecture compatible with an_exposure control circuit which_can reliably_control,_even in large_pixel_arrays, the_exposure process regardless of whether the pixels_100 of_the imager 200 support non-destructive reads._1. Field of the_Invention
The_present invention relates to radio frequency_signal tuners, and specifically to configurations_with multiple tuners connected to_one_signal_source.
2. Prior Art
It is often_desired to have two or more_tuners receive different,_or occasionally identical, signal channels from the_same_input source simultaneously. This situation arises,_for_example, in picture-in-picture applications. Another example_is_a_watch-and-record set-top box where one_tuner is used for receiving the_channel for the TV whereas the other tuner is_receiving a channel_that is being recorded. The_signal_source_to the multiple tuners can be taken directly from a_coaxial cable_connector or alternatively_from an amplified or filtered signal inside a set-top box.
In_prior art, the radio frequency (RF) input_signal is usually distributed to the tuners through a daisy-chain, as_shown in FIG. 1. This has benefits when_using traditional