JPS6064590A - Color solid-state image pickup device - Google Patents

Abstract

PURPOSE:To prevent generation of a false color signal because of a vertical correlation error by using a frequency interleave type color filter array and obtaining alternately two color difference signals from an identical scanning line signal at each scanning line. CONSTITUTION:A modulation signal is separated from an image of a signal formed on a solid-state image pickup element 1 via a color filter array where white-green are arranged on the n-th scanning line and cyan-yellow are arranged on the (n+1)-th scanning line by a band pass filter 10 and a sum and a diffference chrominance signal are extracted by a demodulator 11 and a low pass filter 12. In case of the sum signal, a color difference signal is formed from a low frequency component separated at a low pass filter 13 and in case of the difference signal, the white balance is applied by an adder 17 and two color difference signals are formed by the signal processing using the result of white balance as it is as the color difference signal. Since the two color difference components are formed from the modulation component and the low frequency component obtained from the identical scanning line signal, generation of the false color signal is prevented.

Description

【発明の詳細な説明】 本発明は固体撮像素子を用いたカラー撮像装置に係り、
特に偽色信号の発生が少なく、鮮明なカラー画像が得ら
れるカラー固体撮像装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color imaging device using a solid-state imaging device,
In particular, the present invention relates to a color solid-state imaging device that produces clear color images with less generation of false color signals.

１個の撮像素子を用いてカラーテレビジョン信号を得る
一方式として垂直相関周波数分離方式が周知である。こ
の方式は透明と黄、透明とシアンより成る２種のフィル
ターを重ね合わせて被写体の実像を結ぶ位置に置き、赤
信号と青信号を空間変調し、空間変調の周波数で決まる
搬送波成分（以下変調成分と略記する。）として低域の
輝度信号成分と周波数多重化して撮像素子から出力し、
この撮像素子の出力信号を低域成分と変調成分とに分離
し、変調成分と、これを１水平走査期間だけ遅延した成
分との加算信号及び減算信号を形成し、この加算及び減
算信号を復調して赤及び青信号を取り出し、これら２原
色信号と前記低域成分とからカラーテレビジョン信号を
得ている。即ち前記２種のフィルターの配列を隣り合っ
た２本の走査線信号に含まれているそれぞれの赤の変調
成分と青の変調成分が周波数インターリ−ピング関係を
持たせるように選び、垂直相関で２つの変調成分を分離
するため、垂直相関の無い画像で垂直相関誤差による極
めて大きな偽色信号が発生する欠点があった。A vertical correlation frequency separation method is well known as one method for obtaining a color television signal using one image sensor. In this method, two types of filters, transparent and yellow and transparent and cyan, are superimposed and placed in a position that connects the real image of the subject, and the red and blue signals are spatially modulated, and the carrier wave component (hereinafter referred to as the modulation component) determined by the frequency of the spatial modulation is used. ), which is frequency-multiplexed with the low-frequency luminance signal component and output from the image sensor.
Separate the output signal of this image sensor into a low-frequency component and a modulation component, form an addition signal and a subtraction signal of the modulation component and a component delayed by one horizontal scanning period, and demodulate the addition and subtraction signals. A color television signal is obtained from these two primary color signals and the low frequency component. That is, the arrangement of the two types of filters is selected so that the respective red modulation components and blue modulation components contained in two adjacent scanning line signals have a frequency interleaving relationship, and are vertically correlated. Since the two modulation components are separated, there is a drawback that an extremely large false color signal is generated due to a vertical correlation error in an image without vertical correlation.

本発明の目的は前記の欠点を除去し、簡単な構成で偽色
信号の発生が少なく、鮮明なカラー画像が得られるカラ
ー固体撮像装置を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks, and to provide a color solid-state imaging device that has a simple configuration, produces fewer false color signals, and can obtain clear color images.

本発明によれば、複数の色フィルタが周期的に配列され
た色フイルタアレイと前記色フイルタアレイを介して被
写体像が結像される固体撮像素子とから成るカラー固体
撮像装置に於いて、前記固体撮像素子は前記色フイルタ
アレイに対応して得られる信号が第ｎ番目の走査線信号
に第１及び第２の色信号の和信号が変調成分として含ま
れ、第ｎ＋１番目の走査線信号に第１及び第２の色信号
の差信号が変調成分として含まれるように構成された前
記色フイルタアレイを少なくとも備え、前記固体撮像素
子の出力信号を低域成分と変調成分び差信号を用い、前
記和信号と、この和信号と同一の走査線信号から分離し
た前記低域成分とから第１の色差信号を形成し、前記差
信号と同一の走査線信号から分離した前記低域成分を用
いて、この差信号の白バランスを調整して第２の色差信
号を形成し、前記第１５第２の色差信号及び前記低域成
分とからカラーテレビジョン信号を形成することを特徴
とするカラー固体撮像装置が得られる。According to the present invention, in a color solid-state imaging device comprising a color filter array in which a plurality of color filters are arranged periodically and a solid-state imaging device on which a subject image is formed through the color filter array, In the solid-state imaging device, the signal obtained corresponding to the color filter array is such that the nth scanning line signal includes a sum signal of the first and second color signals as a modulation component, and the n+1th scanning line signal contains the sum signal of the first and second color signals as a modulation component. comprising at least the color filter array configured to include a difference signal between the first and second color signals as a modulation component, and converting the output signal of the solid-state image sensor using a low frequency component and a modulation component difference signal; A first color difference signal is formed from the sum signal and the low frequency component separated from the same scanning line signal as the sum signal, and the low frequency component separated from the same scanning line signal as the difference signal is used. and adjusting the white balance of this difference signal to form a second color difference signal, and forming a color television signal from the fifteenth second color difference signal and the low frequency component. An imaging device is obtained.

以下、本発明について図面を用いて詳述する。Hereinafter, the present invention will be explained in detail using the drawings.

゛第１図は既知の垂直相関周波数分離方式の構成を示す
。固体撮像素子１は色フィルタ２が組合わされている。1 shows the configuration of a known vertical correlation frequency separation system. The solid-state image sensor 1 is combined with a color filter 2.

固体撮像素子１の出力信号は低域フィルタ３で低域成分
を分離し、これを輝度信号Ｙとし、一方帯域フィルタ４
で変調成分を分離している。前記の通り変調成分は周波
数インターリ−ピング関係を持っている。即ち変調成分
は走査線ごとに、第ｎ番目の走査線信号では（Ｂ＋Ｒ）
ｃｃｍｗｔ第ｎ＋１番目の走査線信号では（Ｂ　−Ｒ）
　ｔ−ａ　ｗ　ｔ（Ｗは変調周波数を示す。）となされ
ている。この変調成分を１水平走査期間遅延線５で遅延
し、この遅延信号と元の変調成分とを用い垂直相関で赤
及び青の変調成分を分離していた。即ち加算器６で加え
合わせることで逆位相となっている赤の変調成分を打消
して同位相の青の変調成分を取り出し、復調器７で復調
して青信号を得、他方、減算器８で同位相成分を打消し
、逆位相成分である赤の変調成分を取り出し復調器９で
復調して赤信号を得ていた。The output signal of the solid-state image sensor 1 is separated into low-frequency components by a low-pass filter 3, and this is used as a luminance signal Y.
The modulation components are separated. As described above, the modulation components have a frequency interleaving relationship. That is, the modulation component is (B+R) for each scanning line, and for the nth scanning line signal.
ccmwt n+1st scanning line signal (B - R)
t-a w t (W indicates the modulation frequency). This modulation component is delayed by a delay line 5 for one horizontal scanning period, and the red and blue modulation components are separated by vertical correlation using this delayed signal and the original modulation component. That is, adder 6 adds the red modulation components to cancel out the opposite phase red modulation components, extracts the same phase blue modulation components, demodulates them in demodulator 7 to obtain a blue signal, and subtracter 8 The in-phase component is canceled out, and the red modulated component, which is an anti-phase component, is extracted and demodulated by a demodulator 9 to obtain a red signal.

しかしながら、この従来の方式では、例えば垂直輪邪部
をこ代表されるような垂直相関の無い部分において、隣
り合った２本の走査線信号に含まれる変調成分の大きさ
が異なると、加算器６での逆位相成分の打消し及び減算
器８での同位相成分の打消しができず、これが垂直相関
誤差となり、極めて大きな偽色信号がツ；う生して画質
が劣化する欠点があった。However, in this conventional method, if the magnitude of the modulation components included in two adjacent scanning line signals differs in the area where there is no vertical correlation, such as a vertical loop area, the adder 6 and the in-phase component cannot be canceled out in the subtracter 8, which results in a vertical correlation error, producing an extremely large false color signal and deteriorating the image quality. Ta.

本発明は上述した従来の欠点を除去し、偽色信号を無く
すため、各走査線信号の変調成分に含まれる和及び差の
色信号を互いに分離することなくそのまま用いて色差信
号を形成する様にしたものである。第２図はこの本発明
のカラー固体撮像装置の構成を示す。固体撮像素子１と
色フイルタアレイ２は第１図におけるものと同一である
。色フイルタアレイ２は第３図に一例を示す様に第ｎ−
ｉ目の走査線に白−緑（Ｗ−Ｇ）、第ｎ　−１−１第目
の走査線にシアン−黄（Ｃｙ　Ｙｅ）を配列している。In order to eliminate the above-mentioned conventional drawbacks and eliminate false color signals, the present invention creates a color difference signal by directly using the sum and difference color signals contained in the modulation components of each scanning line signal without separating them from each other. This is what I did. FIG. 2 shows the configuration of the color solid-state imaging device of the present invention. The solid-state image sensor 1 and color filter array 2 are the same as those in FIG. The color filter array 2 has an n-th color filter as shown in FIG.
White-green (W-G) is arranged on the i-th scanning line, and cyan-yellow (Cy Ye) is arranged on the (n-1-1)th scanning line.

被写体の像はこの色フイルタアレイ２で空間変調されて
固体撮像素子ｌに結像される。この固体撮像素子１の出
力信号を帯域フィルタＩＯに供給し、変調成分を分離す
る。次に分離した変調成分を復調器１１で復調し、次い
で低域フィルタ１２を通して和及び差の色信号を取り出
す。本例では第３辺の通り、赤色光が透過できる白面及
び黄（Ｙｅ）フィルタを走査線ごとに逆位相となった市
松配置とし、青色光が透過できる白（Ｗ）及びシアン（
Ｃｙ）フィタを走査線ごとに同位相どなった縦配置とし
たため、固体撮像素子１から得られる各走査線信号に含
まれる変調成分は第ｎ番目の走査線（（ｎ（Ｈ））では
次式（１）で示され％　等１＋１番目の走査線（（ｎ＋
１ｉ）１））では次式（２）で示すものとなる。The image of the subject is spatially modulated by the color filter array 2 and formed on the solid-state image sensor l. The output signal of this solid-state image sensor 1 is supplied to a bandpass filter IO to separate modulation components. Next, the separated modulation components are demodulated by a demodulator 11, and then passed through a low-pass filter 12 to extract the sum and difference color signals. In this example, as shown in the third side, white (W) and cyan (Ye) filters that allow red light to pass through are arranged in a checkered pattern with opposite phases for each scanning line, and white (W) and cyan (Ye) filters that allow blue light to pass through.
Cy) Since the filters are vertically arranged with the same phase for each scanning line, the modulation component included in each scanning line signal obtained from the solid-state image sensor 1 is as follows for the nth scanning line ((n(H)). As shown in equation (1), % etc. 1+1st scanning line ((n+
1i)1)) is expressed by the following equation (2).

（Ｂ十几）（２）ｗｔ　（（帽Ｈ１）　・・・・・・（
１）（Ｂ−Ｒ）ｃｏｓｗｔ　（（ｎ＋　１（Ｉ（））　
−（２）これら変調成分を復調して低域フィルタ１２か
ら取り出される和及び差の色信号は次式（３）及び（４
）で示される通り走査線ごとに和信号と差信号が交互に
繰返して得られる。(B 10) (2) wt ((hat H1) ・・・・・・(
1)(BR) coswt ((n+ 1(I())
-(2) The sum and difference color signals extracted from the low-pass filter 12 by demodulating these modulation components are expressed by the following equations (3) and (4).
), a sum signal and a difference signal are obtained by alternately repeating each scanning line.

Ｂ　＋　Ｒ（（ｎ（Ｈ））　・・・・・・（３）Ｂ−Ｒ
（（ｎ＋ｊｉ刊）　・・・・・・（４）一方、固体撮像
素子１の出力信号から低域フィルタ１３で狭帯域の低域
成分ＹＬを分離する。この低域成分ＹＬを減算器１４に
供給する。減算器１４では前記（３）式の和信号と低域
成分ＹＬから次式（５）で示される第１の色差信号を形
成する。B + R ((n(H)) ...... (3) B-R
((published by n+ji) (4) On the other hand, a low-pass filter 13 separates a narrow-band low-frequency component YL from the output signal of the solid-state image sensor 1. This low-frequency component YL is sent to a subtracter 14. The subtracter 14 forms a first color difference signal shown by the following equation (5) from the sum signal of equation (3) and the low frequency component YL.

（Ｂ＋Ｒ）　−ＹＬ　・・・・・・（５）他方、低域成
分ＹＬは差動増幅器１５に供給され、正負両極性の出力
が作られ調整器１６に供給さｎる。(B+R) -YL (5) On the other hand, the low frequency component YL is supplied to the differential amplifier 15, and outputs having both positive and negative polarities are produced and supplied to the regulator 16.

調整器１６の出力は加算器１７に供給される。加算器１
７では前記（４）式の差信号に低域成分ＹＬ　ａ）　１
部を加える。前述の減算器１４においては％（５１式の
通り必ず正極性の信号である和信号（Ｂ＋Ｒ）と低域成
分ＹＬとから第１の色差信号を形成しているが他方、（
４）式で示される差信号はこの差信号自身で色差信号を
形成しているが照明の色温度によってＲ及びＢの信号の
大きさの比率が変わるため正負両極性の値を取り得る。The output of regulator 16 is fed to adder 17. Adder 1
7, the low frequency component YL a) 1 is added to the difference signal of equation (4) above.
Add part. In the subtracter 14 described above, the first color difference signal is formed from the sum signal (B+R), which is always a positive polarity signal as per equation 51, and the low frequency component YL, but on the other hand, (
The difference signal expressed by equation 4) forms a color difference signal by itself, but the ratio of the magnitudes of the R and B signals changes depending on the color temperature of the illumination, so it can take values of both positive and negative polarities.

このため調整器１６から加算器１７に供給される低域成
分ＹＬのＬ部はこれを補正するもので、白色を撮像した
状態で加算器１７′から得られる色差信号が零となるよ
うに加える低域成分ＹＬの大きさと極性を調整する。従
って加算器１７からは次式（６）で示される第２の色差
信号が得られる。Therefore, the L part of the low frequency component YL supplied from the adjuster 16 to the adder 17 is for correcting this, and is added so that the color difference signal obtained from the adder 17' becomes zero when white is imaged. Adjust the magnitude and polarity of the low frequency component YL. Therefore, the adder 17 obtains a second color difference signal expressed by the following equation (6).

（Ｂ−刊）±ΔＹＬ　・・・・・・（６）第４図は前述
の第１及び第２の色差信号を示すベクトル図である。前
記（３）式で示す和信号はマゼンタ（Ｂ＋Ｒ＝Ｍｇ）色
を表わし、原点からマゼンタ方向の成分であるから前記
（５）式で示す第１の色差信号はマゼンタ−ｍｃ　（Ｍ
ｇ　−Ｇ　）方向のベクトル成分である。また前記（４
）式で示す差信号は青−赤（Ｂ−Ｒ）方向のベクトル成
分であり、前述した通りこの信号自身で色差信号を形成
しているが赤と青信号の比率によっては無彩色を撮像し
た時に多少原点からずれるため前記（６）式で示す通り
△ＹＬ信号で白バランスをとる操作が必要である。(B-issue) ±ΔYL (6) FIG. 4 is a vector diagram showing the aforementioned first and second color difference signals. The sum signal shown in equation (3) above represents magenta (B+R=Mg) and is a component in the magenta direction from the origin, so the first color difference signal shown in equation (5) above is magenta - mc (M
g - G ) is a vector component in the direction. Also, the above (4
) The difference signal shown by the formula is a vector component in the blue-red (B-R) direction, and as mentioned above, this signal itself forms a color difference signal, but depending on the ratio of the red and blue signals, when imaging an achromatic color, Since there is some deviation from the origin, it is necessary to perform white balance using the ΔYL signal as shown in equation (6) above.

なお第４図で明らかなように前記（４）式の差信号はＲ
−Ｂで表わされる差信号でも全く同様に青−光方向のベ
クトル成分となる。この場合第３図のＣＹとｙｅが入れ
替った色フィルタ配列となる。As is clear from FIG. 4, the difference signal in equation (4) above is R
The difference signal represented by -B also becomes a vector component in the blue-light direction in exactly the same way. In this case, the color filter arrangement will be such that CY and ye in FIG. 3 are exchanged.

得られた２つの色差信号はスイッチ１８で走査線ごとに
第ｎ番目の走査線では減算器１４の出力を、第ｎ＋１番
目の走査線では加算器１７の出力をそれぞれ切り換える
。次にこの１水平走査線ごとに交互に繰返す２つの色差
信号を１水平走査期間遅延線１９と１水平走査線ごとの
切り換えスイッチ２０で同時化し、カラーエンコーダ２
１に供給する。カラーエンコーダ２１はこの２つの色差
信号と、固体撮像素子１の出力信号を低域フィルタ２２
及びプロセス回路ｎを通して得た輝度信号Ｙとからカラ
ーテレビジョン信号を形成する。The two obtained color difference signals are used to switch the output of the subtracter 14 for the n-th scanning line and the output of the adder 17 for the n+1-th scanning line for each scanning line using a switch 18. Next, the two color difference signals that are alternately repeated for each horizontal scanning line are synchronized by the delay line 19 for one horizontal scanning period and the changeover switch 20 for each horizontal scanning line, and the color encoder 2
Supply to 1. The color encoder 21 passes these two color difference signals and the output signal of the solid-state image sensor 1 through a low-pass filter 22.
A color television signal is formed from the luminance signal Y obtained through the process circuit n.

上述した本発明によれば、走査線ごとに交互に得られる
ＲとＢの和及び差信号を単独のＲ及びＢ信号に分離する
ことなく和及び差信号のまま用いて、和信号のさきには
、Ａ°口倍信号低域成分とから色差信号を形成し、差信
号のときには、白バランスをとるのみでそのまま色差信
号として用いる信号処理によって２つの色差信号を形成
し、しかちこれら２つの色差信号の形成を同一の走査線
信号から得らｎる変調成分と低域成分とから行なってい
るため、垂直相関の無い画像においても偽色信号が発生
せず、鮮明なカラー画像が得られる。According to the present invention described above, the sum and difference signals of R and B obtained alternately for each scanning line are used as they are without separating them into individual R and B signals. A color difference signal is formed from the low frequency component of the A° mouth multiplied signal, and when it is a difference signal, two color difference signals are formed by signal processing that is used as a color difference signal as is with just white balance, and these two color difference signals are Since the color difference signal is formed from the modulation components and low-frequency components obtained from the same scanning line signal, no false color signals occur even in images without vertical correlation, and clear color images can be obtained. .

次に本発明の他の実施例について説明する。第５図は同
一出願人が出願した特願昭５８−０４４７３７号に於て
提案した、垂直方向に２つの画素の信号を混合して読み
出し、混合の組合せをフィールドによって上下方向−こ
変えてインターレースを行なわせる方式の色フイルタア
レイの配列の一例を示すものである。図において各画素
２４には、第１行目及び第３行目に白−黄（Ｘ’Ｖ−Ｙ
ｅ）、第２行目には白−緑（Ｗ−Ｏ）、第４行目にはシ
アン−黄（ＣｖＹｅ）が配列されている。各行にふいて
含まれる変調成分は次式（７）〜（１（Ｉｔで示すもの
となっている。Next, other embodiments of the present invention will be described. Figure 5 shows a method proposed in Japanese Patent Application No. 58-044737 filed by the same applicant, in which the signals of two pixels are read out by mixing them in the vertical direction, and the mixed combination is changed in the vertical direction depending on the field for interlacing. This figure shows an example of an arrangement of color filter arrays that performs the following. In the figure, each pixel 24 has white-yellow (X'V-Y
e), white-green (W-O) is arranged in the second row, and cyan-yellow (CvYe) is arranged in the fourth row. The modulation components included in each row are shown by the following equations (7) to (1(It).

Ｂ　囲ｗｔ（１行）・・・・・・（７）（Ｂ−１−１も
）　ｃｏｓ　ｗｔ　（２行）・−−４８）Ｂ、璃ｗｔ（
３行）　・・・・−・（９）（Ｂ−Ｒ）ｃｏｓｗｔ　（
４行）　−・−（ｔ１１固体操像素子が一例としてＣＣ
Ｄ撮像素子の場合、各画素からの信号を垂直転送レジス
タ内で加え合わせて読み出す。即ち第１フイールドでは
第５図の第１及び第２行を加え合わせた信号を第ｎ番目
の走査線信号とし、第３及び第４行を加え合わせた信号
を第ｎ　＋　１番目の走査線信号とする。B enclosure wt (1 line) (7) (B-1-1 also) cos wt (2 lines)・--48) B, li wt (
3 lines) ・・・・・・(9)(B-R)coswt (
4 lines) ---(t11 solid state image element is CC
In the case of a D image sensor, signals from each pixel are added together in a vertical transfer register and read out. That is, in the first field, the signal obtained by adding the first and second rows in FIG. Signal.

次に第２フイールドでは加え合わせる組合わせを上下方
向で変え、第２及び第３行を加え合わせた信号を第ｎ′
番目の走査線信号、第４及び第１行を加え合わせた信号
を第ｎ＋１番目の走査線信号とするようにしている。こ
の抗み出し方法によれば、各画素の信号がフィールドご
とζこ全て読み出されるフィールド動作を行ない、かつ
インターレース動作を行わせることが可能である。次に
この動作によって得られる各走査線信号に含まれる変調
成分は、゛前記（７）〜住０）式で示した各行の変調成
分が加゛え合わされた信号となり、第１フイールドでは
次式Ｉ及びＵａ、第２フイールドでは次式０り及び（１
４）で示される。Next, in the second field, the combination to be added is changed in the vertical direction, and the signal obtained by adding the second and third rows is added to the n'th
The signal obtained by adding the th scanning line signal, the fourth row, and the first row is set as the (n+1)th scanning line signal. According to this projecting method, it is possible to perform a field operation in which all the signals of each pixel are read out for each field, and also to perform an interlace operation. Next, the modulation components included in each scanning line signal obtained by this operation are the sum of the modulation components of each row shown in equations (7) to 0) above, and in the first field, the following equation I and Ua, in the second field, the following formulas 0 and (1
4).

即ち各フィールド共に第ｎ番目の走査線信号からは（２
Ｂ＋ｆ（）で示される和信号が、第ｎ＋１番目の走査線
信号からは（２Ｂ−Ｒ）で示される差信号がそれぞれ変
調成分として得られる。従って、第２図、第３図及び第
４図に於て説明した第１の実施例に於て色フイルタアレ
イ２を第５図の色フイルタアレイに変更しても全く同様
にして２つの色差信号を得ることができる。なお、この
時の２つの色差信号は次式（１９及び（ｔｅで示す値と
なる。That is, for each field, from the nth scanning line signal (2
A sum signal represented by B+f() is obtained as a modulation component, and a difference signal represented by (2B-R) is obtained from the (n+1)th scanning line signal, respectively. Therefore, even if the color filter array 2 in the first embodiment explained in FIGS. 2, 3, and 4 is changed to the color filter array shown in FIG. I can get a signal. Note that the two color difference signals at this time have values shown by the following equations (19 and (te).

（２Ｂ＋Ｒ）−ＹＬ　・・・・・霞 （２Ｂ−Ｂ）±ΔＹＬ　・・・・・ｉｌＱこのｔｔｓ　
、　ｕｅ式と前記の＋５）　、　（＋３）式を比較する
と和及び差信号中のＲ信号とＢ信号の比率が異なってお
り、第３図の色フィルクアレイを用いる場合と第５図の
色フイルタアレイを用いる場合では色再現性が異なって
くる。色再現性は前記低域成分ＹＬに関連し、色再現性
を良好にするためには低域成分ＹＬに含まれているＲ成
分とＢ成分の比率を和及び差信号中のＲ信号とＢ信号の
比率ｔこ近すけることが必要である。第５図の色フイル
タアレイを用いると前述の条件を必ずしも満足しないが
、仁の場合には第４図で示した色差信号のベクトル方向
を若干回転させることで最適化することができる。(2B+R)-YL...Hasumi (2B-B)±ΔYL...ilQ this tts
, ue formula and the above-mentioned +5), (+3) formula, the ratios of R and B signals in the sum and difference signals are different. When using an array, color reproducibility will differ. Color reproducibility is related to the low frequency component YL, and in order to improve color reproducibility, the ratio of the R component and the B component included in the low frequency component YL is summed, and the R signal and B component in the difference signal are It is necessary to keep the signal ratio t close to each other. If the color filter array shown in FIG. 5 is used, the above-mentioned conditions are not necessarily satisfied, but in the case of color, optimization can be achieved by slightly rotating the vector directions of the color difference signals shown in FIG.

以上第２〜第５図を用いて詳述した通り本発明は、従来
、垂直相関分離による色信号分離しかできないと考えら
れていた周波数インターリーブ型の色フイルタアレイを
用いて、垂直相関処理を行なわず走査線ごとに２つの色
差信号を同一の走査線信号から交互に得ることによって
従来の垂直相関処理方式の欠点であった垂直相関誤差に
よる偽色信号の発生を無くしたものである。なお説明で
は第３図及び第５図の色フイルタアレイについて行なっ
たが、詳細な説明で明らかな通り本発明は第３図及び第
５図の色フイルタアレイ′に限定されるものではなく５
周波数インターリーブ型の色フイルタアレイであれば全
て用いることができ、この周波数インターリーブ壓の色
フイルタアレイは例えばテレビジョン学会１９８３年金
国大会予稿集ｐ９１〜Ｉ）９２において述べられている
１００　種類の色フイルタアレイなどについて全て同様
に用いることができる。As described above in detail using FIGS. 2 to 5, the present invention performs vertical correlation processing using a frequency interleaved color filter array, which was conventionally thought to be capable of separating color signals only by vertical correlation separation. By alternately obtaining two color difference signals for each scanning line from the same scanning line signal, the generation of false color signals due to vertical correlation errors, which is a drawback of the conventional vertical correlation processing method, is eliminated. Although the description has been made regarding the color filter arrays shown in FIGS. 3 and 5, as is clear from the detailed description, the present invention is not limited to the color filter arrays shown in FIGS.
Any frequency interleaved color filter array can be used, and this frequency interleaved color filter array may be one of the 100 types of color filters described in the Proceedings of the 1983 Annual Conference of the Television Society of Japan, pages 91-1) 92. All the same can be used for arrays and the like.

なお、実施例ではＲ及びＢの和及び差信号を用いて第４
図に示した青−赤（Ｂ−Ｒ）方向とマゼンタ−緑（Ｍｇ
−Ｇ）方向の２つの色差信号を形成したが、和及び差信
号は几及びＢ信号以外の信号でも良く、ベクトルの方向
を和及び差信号に一致させれば全く同様にカラーテレビ
ジョン信号を得ることができる。In addition, in the embodiment, the sum and difference signals of R and B are used to calculate the fourth
The blue-red (B-R) direction and magenta-green (Mg
Although two color difference signals in the -G) direction are formed, the sum and difference signals may be signals other than the 几 and B signals, and if the direction of the vector is made to match the sum and difference signals, a color television signal can be generated in exactly the same way. Obtainable.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は従来の垂直相関周波数分離方式の一例を示す構
成図、第２図は本発明のカラー固体撮像装置の構成図、
第３図及び第５図は色フイルタアレイを示す図、第４図
はベクトルを示す図である。 なお図において、１は固体撮像素子、２は色フイルタア
レイ、３は低域フィルタ、４は帯域フィルタ、５は１水
平走査期間遅延線、６は加算器、８は減算器、７と９は
復調器、１０は帯域フィルタ、１１は復調器、１２と１
３　、２２は低域フィルタ、１４は減算器、１５は差動
増幅器、１６は調整器％１７は加算器、１８は切り換え
スイッチ、１９は１水平走査期間遅延線、２０は切り換
えスイッチ、２１はカラーエンコーダ、２３はプロセス
回路、２４は画素である。 Σ　の　にFIG. 1 is a block diagram showing an example of a conventional vertical correlation frequency separation method, and FIG. 2 is a block diagram of a color solid-state imaging device of the present invention.
3 and 5 are diagrams showing color filter arrays, and FIG. 4 is a diagram showing vectors. In the figure, 1 is a solid-state image sensor, 2 is a color filter array, 3 is a low-pass filter, 4 is a bandpass filter, 5 is a delay line for one horizontal scanning period, 6 is an adder, 8 is a subtracter, 7 and 9 are demodulator, 10 is a bandpass filter, 11 is a demodulator, 12 and 1
3, 22 are low-pass filters, 14 is a subtracter, 15 is a differential amplifier, 16 is an adjuster, 17 is an adder, 18 is a changeover switch, 19 is a delay line for one horizontal scanning period, 20 is a changeover switch, and 21 is a changeover switch. A color encoder, 23 is a process circuit, and 24 is a pixel. in Σ

Claims (1)

【特許請求の範囲】[Claims] 複数の色フィルタが周期的に配列された色フイルタアレ
イと前記色フイルタアレイを介して被写体像が結像され
る固体撮像素子とから成るカラー固体撮像装置に於いて
、前記固体撮像素子は前記色フイルタアレイに対応して
得られる信号が第ｎ番目の走査線信号に第１及び第２の
色信号の和信号が変調成分として含まれ、第ｎ＋１番目
の走査線信号に第１及び第２の色信号の差信号が変調成
分として含まれるように構成された前記色フイルタアレ
イを少なくとも備え、前記固体撮像素子の出力信号を低
域成分と変調成分とに分離し、変調成分を復調して１水
平走査線ごとに前記和信号と差信号を交互に得、少なく
ともこの和及び差信号を用い、前記和信号と、この和信
号と同一の走査線信号から分離した前記低域成分とから
第１の色差信号を形成し、前記差信号と同一の走査線信
号から分離した前記低域成分を用いてこの差信号の白バ
ランスを調整して第２の色差信号を形成し、前記第１、
第２の色差信号及び前記低域成分上からカラーテレビジ
ョン信号を形成することを特徴とするカラー固体撮像装
置。In a color solid-state imaging device comprising a color filter array in which a plurality of color filters are arranged periodically and a solid-state imaging device on which a subject image is formed through the color filter array, the solid-state imaging device The signals obtained corresponding to the filter array include a sum signal of the first and second color signals as a modulation component in the n-th scanning line signal, and a sum signal of the first and second color signals in the n+1-th scanning line signal. The color filter array includes at least the color filter array configured to include a difference signal of color signals as a modulation component, and separates the output signal of the solid-state image sensor into a low frequency component and a modulation component, demodulates the modulation component, and converts the output signal into 1. The sum signal and the difference signal are obtained alternately for each horizontal scanning line, and using at least the sum signal and the difference signal, a first forming a color difference signal, adjusting the white balance of this difference signal using the low frequency component separated from the same scanning line signal as the difference signal to form a second color difference signal;
A color solid-state imaging device, characterized in that a color television signal is formed from the second color difference signal and the low frequency component.