JPH0754385B2 - Optical write type liquid crystal light valve - Google Patents
Optical write type liquid crystal light valveInfo
- Publication number
- JPH0754385B2 JPH0754385B2 JP15803889A JP15803889A JPH0754385B2 JP H0754385 B2 JPH0754385 B2 JP H0754385B2 JP 15803889 A JP15803889 A JP 15803889A JP 15803889 A JP15803889 A JP 15803889A JP H0754385 B2 JPH0754385 B2 JP H0754385B2
- Authority
- JP
- Japan
- Prior art keywords
- liquid crystal
- light valve
- crystal light
- layer
- fourier transform
- 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 - Fee Related
Links
- 239000004973 liquid crystal related substance Substances 0.000 title claims description 84
- 230000003287 optical effect Effects 0.000 title claims description 36
- 238000009826 distribution Methods 0.000 claims description 33
- 239000005262 ferroelectric liquid crystals (FLCs) Substances 0.000 claims description 14
- 229910021417 amorphous silicon Inorganic materials 0.000 claims description 6
- 239000010410 layer Substances 0.000 description 80
- 239000000758 substrate Substances 0.000 description 18
- 238000003909 pattern recognition Methods 0.000 description 14
- 230000002596 correlated effect Effects 0.000 description 12
- 238000010586 diagram Methods 0.000 description 11
- 230000010287 polarization Effects 0.000 description 11
- -1 boron ions Chemical class 0.000 description 9
- 150000002500 ions Chemical class 0.000 description 9
- 238000004519 manufacturing process Methods 0.000 description 9
- 239000000203 mixture Substances 0.000 description 6
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 6
- 239000000969 carrier Substances 0.000 description 5
- WPYMKLBDIGXBTP-UHFFFAOYSA-N benzoic acid Chemical compound OC(=O)C1=CC=CC=C1 WPYMKLBDIGXBTP-UHFFFAOYSA-N 0.000 description 4
- 238000005468 ion implantation Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 230000005684 electric field Effects 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 125000006850 spacer group Chemical group 0.000 description 3
- 238000007740 vapor deposition Methods 0.000 description 3
- 239000005711 Benzoic acid Substances 0.000 description 2
- 206010034972 Photosensitivity reaction Diseases 0.000 description 2
- 239000013543 active substance Substances 0.000 description 2
- 235000010233 benzoic acid Nutrition 0.000 description 2
- 229910052796 boron Inorganic materials 0.000 description 2
- 230000001427 coherent effect Effects 0.000 description 2
- 230000000875 corresponding effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N nitrogen Substances N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 2
- 230000036211 photosensitivity Effects 0.000 description 2
- 230000002269 spontaneous effect Effects 0.000 description 2
- XEVIRQDFPGFYFL-UHFFFAOYSA-N 5-octoxynaphthalene-1-carboxylic acid Chemical compound C1=CC=C2C(OCCCCCCCC)=CC=CC2=C1C(O)=O XEVIRQDFPGFYFL-UHFFFAOYSA-N 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229910052785 arsenic Inorganic materials 0.000 description 1
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 238000005282 brightening Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 230000005621 ferroelectricity Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Landscapes
- Liquid Crystal (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は光パターン認識や光連想などにおいて、光学的
フーリエ変換像を処理するために用いる光書込型液晶ラ
イトバルブに関する。The present invention relates to an optical writing type liquid crystal light valve used for processing an optical Fourier transform image in optical pattern recognition, optical association and the like.
本発明はレーザビーム,LEDなどの光による書込手段と、
光導電層，光反射層，液晶配向層，液晶層，電圧印加手
段が形成された光書込型液晶ライトバルブにおいて、上
記光導電層の光導電率が面内で中心対称に分布しており
面内の中心から離れるに従って大きくすることにより光
書込される情報の空間周波数成分の大きさを任意に制御
することを可能とし、特に上記光導電層をステップ状に
することにより本発明の液晶ライトバルブの製造を容易
にすると共に、本液晶ライトバルブに用いる液晶層に双
安定メモリ性を有する強誘電液晶とすることによりフー
リエ変換像の二値記録を容易に実現でき感度の高い光パ
ターン認識を実現する手段を提供するものである。The present invention is a laser beam, writing means by light such as LED,
In a photo-writing type liquid crystal light valve in which a photoconductive layer, a light reflection layer, a liquid crystal alignment layer, a liquid crystal layer, and a voltage applying means are formed, the photoconductivity of the photoconductive layer is distributed symmetrically in the plane. It becomes possible to arbitrarily control the magnitude of the spatial frequency component of the information to be optically written by increasing the distance from the center of the plane, and in particular, the liquid crystal of the present invention is formed by forming the photoconductive layer into a step shape. In addition to facilitating the manufacture of light valves, the liquid crystal layer used in this liquid crystal light valve is made of a ferroelectric liquid crystal having a bistable memory property, so that binary recording of Fourier transform images can be easily realized and highly sensitive optical pattern recognition. It provides a means for realizing.
従来より、解像度とコントラストの大きな光書込型液晶
ライトバルブを相関光学に適用して光パターン認識を行
う提案や試みが数多くなされてきた。また、合同変換相
関器を用いた光パターン認識ではフーリエ変換面で二値
化処理を行うことによって相互相関ピークに対するSNR
が向上するという提案もなされてきた〔B.ジャビディ、
C.J.クオ、アプライド・オプチックス、27、663（198
8）:B.Javidi and C.J.Kuo,Appl.Opt.27,633（198
8）〕。Hitherto, many proposals and attempts have been made to apply an optical writing type liquid crystal light valve having high resolution and contrast to correlated optics for optical pattern recognition. Also, in optical pattern recognition using a congruential transform correlator, binarization processing is performed on the Fourier transform plane to obtain the SNR for the cross-correlation peak.
Has been proposed to improve [B. Javidi,
CJ Kuo, Applied Optics, 27, 663 (198
8): B.Javidi and CJKuo, Appl.Opt.27,633 (198
8)].
しかしながら、従来の光書込型液晶ライトバルブはTN液
晶を用いているものが大部分であり、二値化処理された
フーリエ変換像の記録を行うためにはあらかじめフーリ
エ変換像をCCDなどを用いて電気系に取り込み二値化処
理をした後レーザスキャナなどの走査光学系を用いて光
書込型液晶ライトバルブに記録しなければならなかっ
た。また、本発明に見られるような双安定メモリ性を有
する強誘電性液晶を用いた光書込型液晶ライトバルブを
用いるとしてもフーリエ変換像の光強度分布が中心対称
に急激に変化しているために高い空間周波数まで二値化
記録したい場合は極めて強い光を用いてフーリエ変換像
を作り出すか、もしくは長時間露光を行わねばならなか
ったため、逆に低い空間周波数領域のフーリエ変換像が
潰れてしまうという問題点を有していた。However, most of the conventional optical writing type liquid crystal light valves use TN liquid crystal, and in order to record the binarized Fourier transform image, the Fourier transform image is used in advance by using a CCD or the like. It was necessary to use an optical writing liquid crystal light valve for recording by using a scanning optical system such as a laser scanner after taking it into an electric system to perform binarization processing. Further, even if the optical writing type liquid crystal light valve using the ferroelectric liquid crystal having the bistable memory property as used in the present invention is used, the light intensity distribution of the Fourier transform image sharply changes to the center symmetry. Therefore, if you want to binarize and record up to a high spatial frequency, you have to create a Fourier transform image using extremely strong light or perform long-time exposure, so the Fourier transform image in the low spatial frequency region is crushed. It had a problem that it would end up.
本発明の液晶ライトバルブは光導電層の光導電率が面内
で連続的にあるいはステップ状に中心対称に分布してお
り面内の中心から離れるに従って光導電率が大きくなる
ようにしてフーリエ変換像の高周波成分に対する光導電
層の光感度を向上させることにより実質的に広い空間周
波数帯域にわたってフーリエ変換像を記録することを可
能とし上記問題点を解決した。In the liquid crystal light valve of the present invention, the photoconductivity of the photoconductive layer is continuously or stepwise distributed symmetrically in the plane, and the Fourier transform is performed by increasing the photoconductivity with increasing distance from the center of the plane. By improving the photosensitivity of the photoconductive layer to the high frequency components of the image, it is possible to record a Fourier transform image over a substantially wide spatial frequency band and solve the above problems.
本発明の液晶ライトバルブは、一度液晶ライトバルブの
書込面全面を光照射し、その動作しきい値電圧の最大値
よりも十分に高い直流バイアス電圧あるいは100Hz〜50k
Hzの交流電圧を重畳した直流バイアス電圧を電圧印加手
段に印加して強誘電性液晶を一方向の安定状態までそろ
え、その状態をメモリさせるか、もしくは光照射無し
で、暗時のしきい値電圧の最大値よりも十分に高い直流
バイアス電圧あるいは100Hz〜50kHzの交流電圧を重畳し
た直流バイアス電圧を電圧印加手段に印加して強誘電性
液晶を一方向の安定状態までそろえその状態をメモリさ
せる第一の工程と、暗時には動作しきい値電圧の最小値
以下であり、光照射時には動作しきい値電圧の最大値以
上となる逆極性の直流バイアス電圧あるいは100Hz〜50k
Hzの交流電圧を重畳した直流バイアス電圧を電圧印加手
段に印加しながら、レーザ光等によって画像の光書込を
する第二の工程を行う。第二の工程ではレーザ照射を受
けた領域の光導電層にはキャリアが発生し、発生したキ
ャリアは直流バイアス電圧により電界方向にドリフト
し、その結果、光導電層の比抵抗が下がり、レーザ照射
が行われた領域にはしきい値電圧以上の逆極性のバイア
ス電圧が印加され、強誘電性液晶は自発分極の反転に伴
う分子の反転が起こり、もう一方の安定状態に移行し画
像がメモリされる。この画像がフーリエ変換像のように
中心部の光強度が大きな中心対称の光強度分布を持って
いても本発明の液晶ライトバルブの光導電層の光導電率
は面内で中心対称に分布しており、面内の中心から離れ
るに従って大きくなっているため広い空間周波数領域の
フーリエスペクトルを鮮明にメモリすることができる。
このようにして形成されたフーリエ変換像は、第一の工
程によってそろえられたＣダイレクタの方向（またはそ
れと直角方向）に偏光軸を合わせた直線偏光の投影光の
照射および光反射層による反射光の偏光方向に対し、偏
光軸が垂直に（または平行に）なるように配置された検
光子を通した投影により、スクリーン上に読みだすこと
ができる。The liquid crystal light valve of the present invention irradiates the entire writing surface of the liquid crystal light valve with light once, and a DC bias voltage or 100 Hz to 50 k sufficiently higher than the maximum value of the operation threshold voltage.
Apply a DC bias voltage that superimposes an AC voltage of Hz to the voltage application means to align the ferroelectric liquid crystal to a stable state in one direction and store that state, or, without light irradiation, a threshold value in the dark. A DC bias voltage sufficiently higher than the maximum value of the voltage or a DC bias voltage in which an AC voltage of 100Hz to 50kHz is superimposed is applied to the voltage applying means to arrange the ferroelectric liquid crystal to a stable state in one direction and store the state. DC bias voltage of reverse polarity or 100Hz to 50k, which is less than the minimum value of the operation threshold voltage in the first step and dark and more than the maximum value of the operation threshold voltage in the light irradiation.
The second step of optically writing an image with a laser beam or the like is performed while applying a DC bias voltage on which an AC voltage of Hz is superimposed to the voltage applying means. In the second step, carriers are generated in the photoconductive layer in the region irradiated with the laser, and the generated carriers drift toward the electric field due to the DC bias voltage, resulting in a decrease in the specific resistance of the photoconductive layer and the laser irradiation. A bias voltage with a reverse polarity above the threshold voltage is applied to the region where the electric charge is applied, and the ferroelectric liquid crystal undergoes inversion of molecules due to the inversion of spontaneous polarization, transitions to the other stable state, and the image is stored in memory. To be done. Even if this image has a centrally symmetric light intensity distribution in which the central light intensity is large like a Fourier transform image, the photoconductivity of the photoconductive layer of the liquid crystal light valve of the present invention is distributed in the plane with central symmetry. Since the distance increases from the center of the plane, the Fourier spectrum in a wide spatial frequency region can be clearly stored.
The Fourier transform image formed in this way is irradiated with projection light of linearly polarized light whose polarization axis is aligned with the direction of the C director (or the direction perpendicular thereto) aligned in the first step and the light reflected by the light reflection layer. It can be read out on the screen by projection through an analyzer arranged such that its polarization axis is perpendicular (or parallel) to the polarization direction of.
また、前記第二の工程終了後、再び極性を反転させ、暗
時のしきい値電圧の最小値以下であり、明時のしきい値
電圧の最大値以上である直流バイアス電圧を印加しなが
ら光照射を行うことにより、部分消去（部分書込）も行
える。Further, after the second step is completed, the polarity is reversed again, while applying a DC bias voltage that is equal to or lower than the minimum threshold voltage in the dark and equal to or higher than the maximum threshold voltage in the bright. By performing light irradiation, partial erasing (partial writing) can also be performed.
光導電層としては、電子の移動度が大きく暗時の抵抗率
および光照射時の導電率が高く、かつ熱的に安定なａ−
Si:H膜が特に優れた特性を与えることができる。The photoconductive layer has a high electron mobility, a high resistivity in the dark and a high electrical conductivity when irradiated with light, and is thermally stable a-
Si: H films can provide particularly good properties.
以下に本発明の液晶ライトバルブの実施例を図面を用い
て詳細に説明する。第１図は、本発明による液晶ライト
バルブの構造を示す断面図である。従来の液晶ライトバ
ルブと構造が異なる部分は液晶層として光透過率または
光反射率と印加電圧の間に明瞭な双安定性を有する強誘
電性を用い、かつ光導電層の光導電率が中心対称に分布
していることである。Hereinafter, embodiments of the liquid crystal light valve of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing the structure of a liquid crystal light valve according to the present invention. The part of the structure that differs from the conventional liquid crystal light valve uses ferroelectricity with clear bistability between the light transmittance or light reflectance and the applied voltage as the liquid crystal layer, and the photoconductivity of the photoconductive layer is the center. It is distributed symmetrically.
液晶分子を挟持するためのガラスやプラスチック等の透
明基板1a,1bは、表面に透明電極層2a,2b、透明基板の法
線方向から75度から85度の範囲の角度で一酸化砒素を斜
方蒸着した配向膜層3a,3bが設けられている。透明基板1
aと1bはその配向膜層3a,3b側を、スペーサ９を介して関
隙を制御して対向させ、強誘電性液晶層４を挟持するよ
うになっている。The transparent substrates 1a and 1b such as glass or plastic for sandwiching liquid crystal molecules have transparent electrode layers 2a and 2b on the surface, and arsenic monoxide is inclined at an angle in the range of 75 to 85 degrees from the normal direction of the transparent substrate. Oriented film layers 3a and 3b vapor-deposited are provided. Transparent substrate 1
The alignment film layers 3a and 3b of the a and 1b are opposed to each other by controlling a clearance via a spacer 9 to sandwich the ferroelectric liquid crystal layer 4.
また、光による書込側の透明電極層2a上には光導電層5,
遮光層6,強電体ミラー７が配向膜3aとの間に積層形成さ
れ、書込側の透明基板1aと読みだし側の透明基板1bのセ
ル外面には、無反射コーティング層8a,8bが形成されて
いる。Further, the photoconductive layer 5, on the transparent electrode layer 2a on the writing side by light,
A light-shielding layer 6 and a ferroelectric mirror 7 are laminated and formed between the alignment film 3a, and antireflection coating layers 8a and 8b are formed on the cell outer surfaces of the transparent substrate 1a on the writing side and the transparent substrate 1b on the reading side. Has been done.
光導電層５の光導電率は面内で中心対称に分布しており
面内の中心から離れるに従って大きくなるように作製し
た。第２図は光導電率が中心対称分布を持つ場合の光導
電層の比抵抗分布図である。第２図に示すように光導電
膜の暗時の比抵抗は面内の中心付近で最大値VDを取り中
心から離れるに従ってしだいに小さくなる。また、光導
電膜の明時の比抵抗も同様に面内の中心付近で最大値VP
を取り中心から離れるに従ってしだいに小さくなる。従
って、作用で説明した第二の工程に示すように、暗時に
おいて動作しきい値電圧の最小値よりも小さな逆極性の
直流バイアス電圧あるいは100Hz〜50kHzの交流電圧を重
畳した直流バイアス電圧が透明電極層2aと遮光層６の間
に分圧されるように透明電極層2aと透明電極層2bの間に
電圧を印加しながら、レーザ光を用いて所定の画像のフ
ーリエ変換像を透明基板1aの側から照射すると、フーリ
エ変換像が照射された領域の光導電層にはキャリアが発
生し、発生したキャリアは直流バイアス電圧V1により電
界方向にドリフトし、その結果、光導電層の比抵抗が下
がり、第２図の明時の比抵抗で示す曲線に対応した電圧
降下が生じるためにフーリエ変換像が照射された領域に
はしきい値電圧以上の逆特性のバイアス電圧が印加さ
れ、強誘電性液晶は自発分極の反転に伴う分子の反転が
起こり、もう一方の安定状態に移行しフーリエ変換像が
メモリされる。この時、本発明の液晶ライトバルブの光
導電層の光導電率は、面内で中心対称に分布しており面
内の中心から離れるに従って大きくなっているため、第
２図に示すようにフーリエ変換像が照射されている領域
の内、面内の中心から離れるに従って実効的な光感度が
大きくなるために、フーリエ変換像の低周波成分よりも
高周波成分の方が高感度で記録されることになる。一
方、光学的フーリエ変換像の光強度は一般的に高周波成
分領域になるにつれて急激に減衰するような分布とな
る。第３図に一般的な光学的フーリエ変換像の光強度分
布図を示す。一般的には、第３図に示すような光学的フ
ーリエ変換像の隣り合った次数のピークの強度比は1:10
〜1:100程度である。The photoconductivity of the photoconductive layer 5 was distributed symmetrically in the plane, and was prepared so as to increase as the distance from the center of the plane increased. FIG. 2 is a resistivity distribution diagram of the photoconductive layer in the case where the photoconductivity has a centrosymmetric distribution. As shown in FIG. 2, the dark specific resistance of the photoconductive film takes a maximum value V D near the center of the plane and becomes gradually smaller as the distance from the center increases. Similarly, the specific resistance of the photoconductive film when bright is the maximum value V P near the center of the plane.
It becomes smaller as it gets away from the center. Therefore, as shown in the second step explained in the operation, the DC bias voltage of the reverse polarity smaller than the minimum value of the operation threshold voltage or the DC bias voltage superposed with the AC voltage of 100 Hz to 50 kHz is transparent in the dark. While applying a voltage between the transparent electrode layer 2a and the transparent electrode layer 2b so that the voltage is divided between the electrode layer 2a and the light-shielding layer 6, a Fourier transform image of a predetermined image is formed using a laser beam on the transparent substrate 1a. When irradiated from the side of, the carrier is generated in the photoconductive layer in the region irradiated with the Fourier transform image, and the generated carriers drift in the direction of the electric field due to the DC bias voltage V 1 , and as a result, the specific resistance of the photoconductive layer. , And a voltage drop corresponding to the curve shown by the specific resistance at the time of light in FIG. 2 occurs, a bias voltage having an inverse characteristic higher than the threshold voltage is applied to the region irradiated with the Fourier transform image, Dielectric liquid crystal is spontaneous Inversion of molecules with the electrode inversion occurs, the Fourier transform image moves to the other stable state is memory. At this time, the photoconductivity of the photoconductive layer of the liquid crystal light valve according to the present invention is distributed symmetrically in the plane and increases as the distance from the center of the plane increases. Therefore, as shown in FIG. Since the effective photosensitivity increases as the distance from the center of the plane in the area irradiated with the converted image increases, the high-frequency component is recorded with higher sensitivity than the low-frequency component of the Fourier transform image. become. On the other hand, the light intensity of the optical Fourier transform image generally has a distribution that abruptly attenuates in the high frequency component region. FIG. 3 shows a light intensity distribution chart of a general optical Fourier transform image. Generally, the intensity ratio of the adjacent peaks of the order in the optical Fourier transform image as shown in FIG. 3 is 1:10.
It is about 1: 100.
従って、以上述べた本発明の液晶ライトバルブの記録特
性を用いればフーリエ変換像の高周波成分の光強度が第
３図に示すように急激に減少しても従来の液晶ライトバ
ルブ以上に正確にフーリエ変換像の高周波成分を記録で
きるために、本発明の液晶ライトバルブに記録されたフ
ーリエ変換像を用いて、光学的相関処理を行ってパター
ン認識を行うことにより複雑な画像パターン認識が可能
となった。Therefore, by using the recording characteristics of the liquid crystal light valve of the present invention described above, even if the light intensity of the high frequency component of the Fourier transform image sharply decreases as shown in FIG. Since the high-frequency component of the converted image can be recorded, a complex image pattern can be recognized by performing optical correlation processing and pattern recognition using the Fourier transform image recorded in the liquid crystal light valve of the present invention. It was
次に、本発明の液晶ライトバルブの製造方法の一実施例
について簡単に説明する。まず、透明基板1a,1bとして
透明ガラス基板を用意し、透明電極層2a,2bとして当該
ガラス基板の表面にITO透明電極層を形成した。また、
光書込側透明電極層2a上にはSiF4を主体とするガスを放
電分解して厚さ３μｍのイントリンシックな水素化アモ
ルファスシリコンを形成した後、ホウ素イオン，酸素イ
オンあるいは窒素イオンをイオン注入して中心対称な光
導電率分布を光導電膜層に付与する。第４図に光導電率
が中心対称分布を持つ光導電膜の作製原理を示す。第４
図において透明基板1aの上に透明電極層2aを形成し、さ
らにイントリンシックな水素化アモルファスシリコンを
用いた光導電層５を形成した基板をイオンガンに近接し
て配し上記のホウ素イオン，窒素イオンあるいは酸素イ
オンなどの注入イオン12を光導電膜に打ち込む。このと
き、イオンガン13のイオン出射口が透明基板1aを見込む
角度は充分大きいため光導電膜に打ち込まれる注入イオ
ン12の数密度分布はガウス分布に近くなる。このような
イオン注入処理をされた水素化アモルファスシリコンの
光導電膜の光導電率は面内で中心対称に分布しており面
内の中心から離れるに従って大きくなることがわかっ
た。言うまでもなくイオン注入する前のイントリンシッ
クな水素化アモルファスシリコンは最も大きな光導電率
を有する組成で作製した。Next, an embodiment of the method of manufacturing the liquid crystal light valve of the present invention will be briefly described. First, transparent glass substrates were prepared as the transparent substrates 1a and 1b, and ITO transparent electrode layers were formed on the surfaces of the glass substrates as the transparent electrode layers 2a and 2b. Also,
On the transparent electrode layer 2a on the optical writing side, a gas mainly composed of SiF 4 is discharged and decomposed to form an intrinsic hydrogenated amorphous silicon having a thickness of 3 μm, and then boron ions, oxygen ions or nitrogen ions are ion-implanted. Then, the photoconductive film layer is provided with a centrosymmetric photoconductivity distribution. FIG. 4 shows the principle of manufacturing a photoconductive film having a photoconductivity having a central symmetrical distribution. Fourth
In the figure, the transparent electrode layer 2a is formed on the transparent substrate 1a, and the substrate on which the photoconductive layer 5 using intrinsic hydrogenated amorphous silicon is further formed is arranged close to the ion gun, and the above-mentioned boron ion, nitrogen ion Alternatively, implanted ions 12 such as oxygen ions are implanted in the photoconductive film. At this time, since the angle at which the ion emission port of the ion gun 13 looks into the transparent substrate 1a is sufficiently large, the number density distribution of the implanted ions 12 implanted in the photoconductive film becomes close to a Gaussian distribution. It was found that the photoconductivity of the photoconductive film of hydrogenated amorphous silicon subjected to such ion implantation treatment is distributed symmetrically in the plane and increases as the distance from the center of the plane increases. Needless to say, the intrinsic hydrogenated amorphous silicon before ion implantation was prepared with the composition having the highest photoconductivity.
このようにして作製した光導電率が中心対称分布を持つ
光導電膜の上に遮光層６を設け、さらにSiとSiO2を15層
積層して光反射層としての誘導体ミラー７を形成した、
誘導体ミラーの可視光反射率が充分大きく光導電層５に
対して読みだし光の影響が極めて小さい場合には遮光層
６を省略することができる。The light-shielding layer 6 was provided on the photoconductive film having the photoconductivity having a central symmetrical distribution, and 15 layers of Si and SiO 2 were further laminated to form the derivative mirror 7 as a light reflecting layer.
When the visible light reflectance of the derivative mirror is sufficiently large and the influence of the light read on the photoconductive layer 5 is extremely small, the light shielding layer 6 can be omitted.
さらに、誘導体ミラー７および読みだし側の透明電極2b
の上に一酸化珪素（SiO）を、基板と蒸着源を結ぶ直線
が基板の法線方向に対して82度の角度になるようにセッ
トし、かつ蒸着の法線方向にセットした水晶振動子式膜
厚計で膜厚を計測しながら、2000Åの厚さに斜方蒸着し
て液晶配向層3a,3bを形成した、透明基板1a,1bはその配
向膜層3aおよび3b側を対向させ、直径1.5μｍのグラス
ファイバーを加えた接着剤よりなるスペーサ９を介して
間隙を制御，形成し、強誘電性液晶層４を挟持するよう
にした。封入した強誘電性組成物は、エステル系SmC液
晶混合物に光学活性物質を添加して強誘電性液晶組成物
としたものでありエステル系SmC液晶混合物として、４
−（（４′−オクチル）フェニル）安息香酸（３″−フ
ルオロ,4″−オクチルオキシ）フェニルエステルと、４
−（（４′−オクチルオキシ）フェニル）安息香酸
（３″−フルオロ,4″−オクチルオキシ）フェニルエス
テルを1:1で混合したものを用い、これに光学活性物質
として５−オクチルオキシナフタレンカルボン酸,1′−
シアノエチルエステルを25重量％加えて強誘電性液晶組
成物としたものを用いた。Furthermore, the dielectric mirror 7 and the transparent electrode 2b on the reading side
Crystal oscillator with silicon monoxide (SiO) set on top of it so that the straight line connecting the substrate and the vapor deposition source is at an angle of 82 degrees with respect to the normal direction of the substrate, and also in the normal direction of vapor deposition. While measuring the film thickness with a formula film thickness meter, the liquid crystal alignment layers 3a, 3b were formed by oblique vapor deposition to a thickness of 2000 Å, the transparent substrates 1a, 1b face the alignment film layers 3a and 3b, A space 9 is controlled and formed through a spacer 9 made of an adhesive to which a glass fiber having a diameter of 1.5 μm is added so as to sandwich the ferroelectric liquid crystal layer 4. The encapsulated ferroelectric composition was prepared by adding an optically active substance to an ester-based SmC liquid crystal mixture to prepare a ferroelectric liquid crystal composition.
-((4'-octyl) phenyl) benzoic acid (3 "-fluoro, 4" -octyloxy) phenyl ester and 4
A mixture of-((4'-octyloxy) phenyl) benzoic acid (3 "-fluoro, 4" -octyloxy) phenyl ester in a ratio of 1: 1 was used, and 5-octyloxynaphthalenecarboxylic acid was used as an optically active substance. Acid, 1'-
A ferroelectric liquid crystal composition prepared by adding 25% by weight of cyanoethyl ester was used.
以上のようにして作製した液晶ライトバルブを用いて行
った光パターン認識の一実施例を説明する。第５図は本
発明の液晶ライトバルブを用いた光パターン認識装置の
原理構成図である。第５図において第１のレーザ光源15
から出射されたコヒーレント光は第１のビームエキスパ
ンダ16によって所定のビーム径に拡大された後、相関像
と被相関像が並べて記録してある写真フィルム17に照射
され、第１のフーリエ変換レンズ18でフーリエ変換され
て本発明の液晶ライトバルブ19の書込面に照射される。
本発明の液晶ライトバルブはあらかじめ暗時のしきい値
電圧の最小値あるいは明時のしきい値電圧の最大値より
も高い電圧を印加して一様に消去されている。そして、
上記フーリエ変換されたレーザ光が本発明の液晶ライト
バルブ19の書込面に照射されたとき本発明の液晶ライト
バルブに暗時のしきい値電圧の最小値と明時のしきい値
電圧の最大値の間の逆特性の直流バイアス電圧あるいは
１〜50kHzの交換電圧を重畳した直流バイアス電圧を所
定の時間印加して写真フィルム17に記録されている相関
像と被相関像のフーリエ変換像を記録する。もちろんこ
の時、本発明の液晶ライトバルブ19には暗時のしきい値
電圧の最小値と明時のしきい値電圧の最大値の間の逆特
性の直流バイアス電圧あるいは１〜50kHzの交流電圧を
重畳した直流バイアス電圧を印加したままで、第１のレ
ーザ光源15を所定の時間だけONさせるか、あるいは第１
のレーザ光源15と本発明の液晶ライトバルブの間の光路
の所定の位置に配した光シャッタを所定の時間だけONさ
せてもよい。次に、第２のレーザ光源20からコヒーレン
ト光を出射した後、第２のビームエキスパンダ21でビー
ムを所望の径に拡大し偏光ビームスプリッタ22により光
路を切り替え本発明の液晶ライトバルブ19の読みだし面
に照射する。この時、本発明の液晶ライトバルブには上
述した相関像と被相関像のフーリエ変換像が記録されて
おり、なんらバイアス電圧は印加されていない。従って
読みだし面に照射された第２のレーザ光源からの光にお
いて、フーリエ変換像が記録されている領域に照射され
た光は偏光面を90度回転させて読みだされ偏光ビームス
プリッタ22を透過し、フーリエ変換像が記録されていな
い領域に照射された光はその偏光面に影響を受けないた
めに再び偏光ビームスプリッタ22で反射される。つま
り、偏光ビームスプリッタ22を透過した直後の光は写真
フィルム17に記録された相関像と被相関像のフーリエ変
換の強度情報となるのである。このようにして読みださ
れた相関像と被相関像のフーリエ変換の強度情報は第２
のフーリエ変換レンズ23で再びフーリエ変換されCCDカ
メラ24で読みだされる。このようにCCDカメラで読みだ
された情報はビデオモニター25で観察でき、この観察さ
れる情報は相関像と被相関像の自己相関ピークおよび相
互相関ピークである。なお、写真フィルム17と本発明の
液晶ライトバルブ19はそれぞれ第１のフーリエ変換レン
ズ18の前焦点面と後焦点面に配されており、本発明の液
晶ライトバルブ19とCCDカメラ24はそれぞれ第２のフー
リエ変換レンズ23の前焦点面と後焦点面に配されてい
る。また、本発明の液晶ライトバルブ19に記録されるフ
ーリエ変換像の大きさが適当でなかったり、CCDカメラ2
4に入力する自己相関ピークおよび相互相関ピークの大
きさが適当でなかったりする場合は、第１のフーリエ変
換レンズ18の後焦点面と本発明の液晶ライトバルブ19の
間に拡大レンズ系を入れたり、第２のフーリエ変換レン
ズ23の後焦点面とCCDカメラ24の間に拡大レンズ系を入
れて像を所望の大きさに拡大することで対処できる。An example of optical pattern recognition performed using the liquid crystal light valve manufactured as described above will be described. FIG. 5 is a principle block diagram of an optical pattern recognition device using the liquid crystal light valve of the present invention. In FIG. 5, the first laser light source 15
The coherent light emitted from the first beam expander 16 expands the beam to a predetermined beam diameter, and then irradiates the photographic film 17 on which the correlated image and the correlated image are recorded side by side, and the first Fourier transform lens. After being Fourier transformed at 18, the writing surface of the liquid crystal light valve 19 of the present invention is irradiated.
The liquid crystal light valve of the present invention is previously erased uniformly by applying a voltage higher than the minimum threshold voltage at dark or the maximum threshold voltage at bright. And
When the Fourier-transformed laser light is applied to the writing surface of the liquid crystal light valve 19 of the present invention, the liquid crystal light valve of the present invention has a minimum threshold voltage when dark and a threshold voltage when bright. A DC bias voltage having an inverse characteristic between the maximum values or a DC bias voltage superposed with an exchange voltage of 1 to 50 kHz is applied for a predetermined time to obtain a Fourier transform image of a correlated image and a correlated image recorded on the photographic film 17. Record. At this time, of course, in the liquid crystal light valve 19 of the present invention, a DC bias voltage having an inverse characteristic between the minimum value of the threshold voltage in the dark and the maximum value of the threshold voltage in the bright, or an AC voltage of 1 to 50 kHz. The first laser light source 15 is turned on for a predetermined time while the DC bias voltage superposed with is applied, or
The optical shutter arranged at a predetermined position on the optical path between the laser light source 15 and the liquid crystal light valve of the present invention may be turned on for a predetermined time. Next, after emitting coherent light from the second laser light source 20, the beam is expanded to a desired diameter by the second beam expander 21 and the optical path is switched by the polarization beam splitter 22 to read the liquid crystal light valve 19 of the present invention. Irradiate the dashi surface. At this time, the liquid crystal light valve of the present invention has the above-described Fourier transform images of the correlated image and the correlated image recorded thereon, and no bias voltage is applied. Therefore, in the light from the second laser light source irradiated on the reading surface, the light irradiated on the area in which the Fourier transform image is recorded is read by rotating the polarization surface by 90 degrees and transmitted through the polarization beam splitter 22. However, the light emitted to the region where the Fourier transform image is not recorded is reflected by the polarization beam splitter 22 again because it is not affected by the polarization plane. That is, the light immediately after passing through the polarization beam splitter 22 becomes intensity information of the Fourier transform of the correlated image and the correlated image recorded on the photographic film 17. The intensity information of the Fourier transform of the correlation image and the correlated image thus read is the second
It is again Fourier-transformed by the Fourier transform lens 23 and read by the CCD camera 24. The information read by the CCD camera can be observed on the video monitor 25, and the observed information is the autocorrelation peak and cross-correlation peak of the correlation image and the correlated image. The photographic film 17 and the liquid crystal light valve 19 of the present invention are arranged on the front focal plane and the rear focal plane of the first Fourier transform lens 18, respectively. The two Fourier transform lenses 23 are arranged on the front focal plane and the rear focal plane. Further, the size of the Fourier transform image recorded in the liquid crystal light valve 19 of the present invention is not appropriate, or the CCD camera 2
If the autocorrelation peak and the cross-correlation peak input to 4 are not appropriate, a magnifying lens system is inserted between the back focal plane of the first Fourier transform lens 18 and the liquid crystal light valve 19 of the present invention. Alternatively, a magnifying lens system may be inserted between the back focal plane of the second Fourier transform lens 23 and the CCD camera 24 to magnify the image to a desired size.
さらに、本発明の液晶ライトバルブ19に第３図に示すよ
うなフーリエ変換像のどの空間周波数領域までいれるか
は、本発明の液晶ライトバルブ19に印加するバイアス電
圧の値を調節することによりある程度調節することが可
能であった。Further, to what extent the spatial frequency region of the Fourier transform image as shown in FIG. 3 can be included in the liquid crystal light valve 19 of the present invention is adjusted to some extent by adjusting the value of the bias voltage applied to the liquid crystal light valve 19 of the present invention. It was possible to adjust.
第５図の写真フィルム17に入力した相関像と被相関像の
一実施例を第６図に示す。第６図に示す入力像は“光”
という漢字を並べて配したネガ像である。An example of the correlation image and the correlated image input to the photographic film 17 of FIG. 5 is shown in FIG. The input image shown in Fig. 6 is "light".
It is a negative image with the kanji side by side.
第６図に示すパターンを第５図に示す写真フィルム17に
記録してそれから得られる相互相関ピークを観察した。
第７図に第６図の液晶ライトバルブ19として従来の液晶
ライトバルブを用いた場合と本発明の液晶ライトバルブ
を用いた場合の相互相関ピークの相違を示す。ここで、
従来の液晶ライトバルブとは第１図に示す断面構造を有
しているが、光導電層５の光導電率は面内で一様なもの
を指す。第７図から本発明の液晶ライトバルブを用いた
方が従来の液晶ライトバルブを用いた場合に比べて相互
相関ピークの半値幅が狭く相互相関ピーク強度も大きく
なっていることがわかる。従来の液晶ライトバルブを用
いた場合においても第１図の強誘電性液晶層４の替わり
にTN液晶層を用いると相互相関ピークの半値幅は第７図
の従来の液晶ライトバルブを用いた場合で示す相互相関
ピークの半値幅よりも広くなることは言うまでもない。
ただし、この場合相互相関ピークの強度は変化しない。
なお、第７図の横軸で示す位置座標は分りやすくするた
めにスケールを拡大してある。このように、本発明の液
晶ライトバルブを用いることにより、光パターン認識す
る場合に極めて重要な量となる相互相関ピークが、従来
の液晶ライトバルブを用いた場合よりもさらに強くシャ
ープに得られることがわかり、従来よりもさらに複雑な
画像や図形や文字などの認識が可能となった。The pattern shown in FIG. 6 was recorded on the photographic film 17 shown in FIG. 5 and the cross-correlation peak obtained therefrom was observed.
FIG. 7 shows the difference in cross-correlation peak between the case of using the conventional liquid crystal light valve as the liquid crystal light valve 19 of FIG. 6 and the case of using the liquid crystal light valve of the present invention. here,
The conventional liquid crystal light valve has the cross-sectional structure shown in FIG. 1, but the photoconductivity of the photoconductive layer 5 is uniform in the plane. It can be seen from FIG. 7 that the liquid crystal light valve of the present invention has a narrower half-value width of the cross-correlation peak and a larger cross-correlation peak intensity than the case of using the conventional liquid crystal light valve. Even when the conventional liquid crystal light valve is used, if the TN liquid crystal layer is used instead of the ferroelectric liquid crystal layer 4 of FIG. 1, the half-value width of the cross-correlation peak is the case of using the conventional liquid crystal light valve of FIG. It goes without saying that the width becomes wider than the half-value width of the cross-correlation peak shown by.
However, in this case, the intensity of the cross-correlation peak does not change.
Note that the scale of the position coordinates shown by the horizontal axis in FIG. 7 is enlarged for easy understanding. As described above, by using the liquid crystal light valve of the present invention, the cross-correlation peak, which is an extremely important amount for recognizing a light pattern, can be obtained more strongly and sharply than in the case of using the conventional liquid crystal light valve. This made it possible to recognize more complicated images, figures, characters, etc. than before.
ここで、第３図に見られるように、フーリエ変換像は像
の中心から離れるにつれてその強度が周期的に変化す
る。従って、液晶ライトバルブに記録したいフーリエ変
換像の空間周波数領域やその周期性があらかじめわかっ
ている場合は、前述してきたように光導電膜の光導電率
が面内で中心対称で面内の中止から離れるに従ってなめ
らかに大きくなるようにしなくても、光導電膜の光導電
率が面内で中心対称で面内の中心から離れるに従ってス
テップ状に変化するだけで前述したのと同様の機能を持
った液晶ライトバルブとすることができる。第８図に本
発明の液晶ライトバルブにおいて光導電膜の光導電率分
布をステップ状に形成した場合の光導電層の比抵抗分布
図を示す。この場合もなめらかな比抵抗分布を持った光
導電膜の場合と同様に、光導電膜の暗時の比抵抗は面内
の中心領域で最大値VDを取り、中心から離れるに従って
ステップ状に小さくなる。また、光導電膜の明時の比抵
抗も同様に面内の中心領域で最大値VPを取り中心から離
れるに従ってステップ状に小さくなる。従って、暗時に
おいてしきい値電圧の最小値よりも小さな逆極性の直流
バイアス電圧あるいは１〜50kHzの交流電圧を重畳した
直流バイアス電圧が第１図の透明電極層2aと遮光層６の
間に分圧されるように透明電極層2aと透明電極層2bの間
に電圧を印加しながら、レーザ光を用いて所定の画像の
フーリエ変換像を透明基板1aの側から照射すると、フー
リエ変換像が照射された領域の光導電膜層にはキャリア
が発生し、発生したキャリアは直流バイアス電圧V1によ
り電界方向にドリフトし、その結果、光導電層の比抵抗
が下がり、第８図の明時の比抵抗で示す曲線に対応する
電圧降下が光導電層に生じるため、フーリエ変換像が照
射された領域にはしきい値電圧以上の逆特性のバイアス
電圧が印加され、強誘電性液晶は自発分極の反転に伴う
分子の反転が起こり、もう一方の安定状態に移行しフー
リエ変換像がメモリされる。Here, as seen in FIG. 3, the intensity of the Fourier transform image changes periodically as the distance from the center of the image increases. Therefore, if the spatial frequency domain of the Fourier transform image to be recorded in the liquid crystal light valve and its periodicity are known in advance, the photoconductivity of the photoconductive film is in-plane symmetry in the plane as described above. Even if the photoconductive film does not need to increase smoothly as it moves away from, it has the same function as described above, except that the photoconductivity of the photoconductive film is centrally symmetric in the plane and changes stepwise as it moves away from the center of the plane. Can be a liquid crystal light valve. FIG. 8 shows a specific resistance distribution diagram of the photoconductive layer in the case where the photoconductive distribution of the photoconductive film is formed stepwise in the liquid crystal light valve of the present invention. Also in this case, as in the case of the photoconductive film having a smooth resistivity distribution, the dark specific resistance of the photoconductive film takes a maximum value V D in the central region of the surface and becomes stepwise as it goes away from the center. Get smaller. Similarly, the specific resistance of the photoconductive film at the time of brightening also takes a maximum value V P in the in-plane central region and decreases stepwise as the distance from the center increases. Therefore, in the dark, a DC bias voltage having a reverse polarity smaller than the minimum threshold voltage or a DC bias voltage in which an AC voltage of 1 to 50 kHz is superimposed is applied between the transparent electrode layer 2a and the light shielding layer 6 in FIG. While applying a voltage between the transparent electrode layer 2a and the transparent electrode layer 2b so that the voltage is divided, when a Fourier transform image of a predetermined image is irradiated from the transparent substrate 1a side using laser light, a Fourier transform image is obtained. Carriers are generated in the photoconductive film layer in the irradiated region, and the generated carriers drift toward the electric field due to the DC bias voltage V 1 , and as a result, the specific resistance of the photoconductive layer is lowered, resulting in the light in FIG. Since a voltage drop corresponding to the curve indicated by the resistivity of the photoconductive layer is generated in the photoconductive layer, a bias voltage having an inverse characteristic equal to or higher than the threshold voltage is applied to the area irradiated with the Fourier transform image, and the ferroelectric liquid crystal is spontaneously generated. Molecular reversal associated with polarization reversal Rolling occurs, the other stable state is entered, and the Fourier transform image is stored.
ステップ状の光導電率分布を持った光導電膜層の作製は
なめらかな光導電率分布を持った光導電膜層の作製より
も再現性が良い。第９図にステップ状の光導電率分布を
持つ光導電層の作製原理図を示す。第４図に示した光導
電率が中心対称分布を持つ光導電膜層の作製原理と異な
っているのはイントリンシックなアモルファスシリコン
５の形成された透明基板1aをイオンガンから充分離れた
位置に配し、光導電膜に打ち込まれる注入イオンの数密
度分布が均一な領域を用いてイオン注入を行うことと、
イオン注入したい所望の領域以外はドーナツ形状のマス
ク14で覆いながらイオン注入を行うことである。The production of a photoconductive film layer having a stepwise photoconductivity distribution has better reproducibility than the production of a photoconductive film layer having a smooth photoconductivity distribution. FIG. 9 shows a principle of manufacturing a photoconductive layer having a stepwise photoconductivity distribution. The difference between the photoconductivity shown in FIG. 4 and the production principle of the photoconductive film layer having a central symmetrical distribution is that the transparent substrate 1a on which the amorphous amorphous silicon 5 is formed is arranged at a position sufficiently separated from the ion gun. Then, ion implantation is performed using a region in which the number density distribution of implanted ions to be implanted in the photoconductive film is uniform.
The ion implantation is performed while covering the region other than the desired region to be ion-implanted with a donut-shaped mask 14.
ステップ状の光導電率分布を持つ光導電膜層を有する本
発明の液晶ライトバルブを用いて第５図に示す光パター
ン認識装置を構成したところ、なめらかな中心対称分布
の光導電率を持つ光導電膜層を有する本発明の液晶ライ
トバルブと同様の優れたパターン認識能力があることが
わかった。A liquid crystal light valve according to the present invention having a photoconductive film layer having a stepwise photoconductivity distribution was used to construct the optical pattern recognition device shown in FIG. 5, and light having a smooth central symmetry distribution was obtained. It was found that the liquid crystal light valve of the present invention having a conductive film layer has the same excellent pattern recognition ability.
なお、本発明の液晶ライトバルブはフーリエ変換像の記
録に対する実施例を主体に説明したが、インコヒーレン
ト光源であるLEDを用いた画像記録や自然光を用いた画
像記録においても、特に入力光画像の強度分布がガウス
分布になっていたりする場合に効果を発揮するものであ
る。Although the liquid crystal light valve of the present invention has been described mainly with respect to the example for recording the Fourier transform image, even in the image recording using the LED which is the incoherent light source and the image recording using natural light, particularly the input light image This is effective when the intensity distribution is Gaussian distribution.
以上述べたように、本発明の液晶ライトバルブはレーザ
ビーム,LEDなどの光による書込手段と、光導電層，光反
射層，液晶配向層，液晶層，電圧印加手段が形成された
光書込型液晶ライトバルブにおいて、上記光導電層の光
導電層の光導電率が面内で中心対称に分布しており、面
内の中心から離れるに従って光導電率が大きくなるよう
にし、特に上記光導電膜層の光導電率分布をステップ状
とし、また、本液晶ライトバルブに用いる液晶層に双安
定メモリ性を有する強誘電性液晶を用いることにより、
光強度分布が中心対称に急激に減衰するようなフーリエ
変換像の高空間周波数成分までも忠実に二値記録するこ
とができ、フーリエ変換を応用した光パターン認識、特
に光相関処理による光パターン認識に対する効果は大き
い。As described above, the liquid crystal light valve of the present invention is an optical writing device in which writing means by light such as a laser beam and LED and a photoconductive layer, a light reflection layer, a liquid crystal alignment layer, a liquid crystal layer, and a voltage applying means are formed. In the embedded liquid crystal light valve, the photoconductivity of the photoconductive layer of the photoconductive layer is distributed symmetrically in the plane, and the photoconductivity increases as the distance from the center of the plane increases. By making the photoconductivity distribution of the conductive film layer stepwise and using a ferroelectric liquid crystal having a bistable memory property in the liquid crystal layer used in the present liquid crystal light valve,
Even the high spatial frequency components of the Fourier transform image where the light intensity distribution is abruptly asymmetrically attenuated can be faithfully recorded in binary, and optical pattern recognition using Fourier transform, especially optical pattern recognition by optical correlation processing Has a great effect on.
第１図は本発明の液晶ライトバルブの構成を示す断面図
であり、第２図は本発明の液晶ライトバルブにおける光
導電率が中心対称分布を持つ光導電層の比抵抗分布を示
す図であり、第３図は一般的な光学的なフーリエ変換像
の光強度分布を示す図であり、第４図は光導電率が中心
対称分布を持つ光導電膜の作製原理図であり、第５図は
本発明の液晶ライトバルブを用いた光パターン認識装置
の原理構成図であり、第６図は第５図の光パターン認識
装置で用いた写真フィルムへの像入力の一実施例を示す
図であり、第７図は第５図の光パターン認識装置に従来
の液晶ライトバルブを用いた場合と本発明の液晶ライト
バルブを用いた場合の相互相関ピーク強度の相違を示す
図であり、第８図は本発明の液晶ライトバルブにおける
光導電率分布をステップ状に形成した光導電膜の比抵抗
分布を示す図であり、第９図はステップ状の光導電率分
布を持つ光導電膜の作製原理を示す図である。 1a,1b……透明基板 2a,2b……透明電極層 3a,3b……配向膜層 ４……強誘電性液晶層 ５……光導電層 ６……遮光層 ７……誘電体ミラー 8a,8b……無反射コーティング ９……スペーサ 10……書込光 11……読みだし光 12……注入イオン 13……イオンガン 14……マスク 15……第１のレーザ光源 16……第１のビームエキスパンダ 17……写真フィルム 18……第１のフーリエ変換レンズ 19……本発明の液晶ライトバルブ 20……第２のレーザ光源 21……第２のビームエキスパンダ 22……偏光ビームスプリッタ 23……第２のフーリエ変換レンズ 24……CCDカメラ 25……ビデオモニターFIG. 1 is a cross-sectional view showing the structure of the liquid crystal light valve of the present invention, and FIG. 2 is a diagram showing the specific resistance distribution of a photoconductive layer having a central symmetrical distribution of photoconductivity in the liquid crystal light valve of the present invention. FIG. 3 is a diagram showing a light intensity distribution of a general optical Fourier transform image, and FIG. 4 is a principle diagram of manufacturing a photoconductive film having a center symmetric distribution of photoconductivity, and FIG. FIG. 6 is a diagram showing the principle configuration of an optical pattern recognition device using the liquid crystal light valve of the present invention, and FIG. 6 is a diagram showing an embodiment of image input to a photographic film used in the optical pattern recognition device of FIG. FIG. 7 is a diagram showing a difference in cross-correlation peak intensity between the case where the conventional liquid crystal light valve is used in the optical pattern recognition device of FIG. 5 and the case where the liquid crystal light valve of the present invention is used. FIG. 8 shows the photoconductivity distribution of the liquid crystal light valve of the present invention. Tsu is a diagram showing the resistivity distribution of the photoconductive layer formed on the looped, FIG. 9 is a diagram illustrating a manufacturing principle of the photoconductive layer with a step-like photoconductivity distribution. 1a, 1b …… Transparent substrate 2a, 2b …… Transparent electrode layer 3a, 3b …… Alignment film layer 4 …… Ferroelectric liquid crystal layer 5 …… Photoconductive layer 6 …… Light-shielding layer 7 …… Dielectric mirror 8a, 8b …… Anti-reflection coating 9 …… Spacer 10 …… Write light 11 …… Read light 12 …… Implanted ions 13 …… Ion gun 14 …… Mask 15 …… First laser light source 16 …… First beam Expander 17 ... Photographic film 18 ... First Fourier transform lens 19 ... Liquid crystal light valve of the present invention 20 ... Second laser light source 21 ... Second beam expander 22 ... Polarizing beam splitter 23 ... … Second Fourier transform lens 24 …… CCD camera 25 …… Video monitor
Claims (4)
手段と、光導電層，光反射層，液晶配向層，液晶層，電
圧印加手段が形成された光書込型液晶ライトバルブにお
いて、上記光導電層の光導電率が面内で中心対称に分布
しており面内の中心から離れるに従って大きくなってい
ることを特徴とする光書込型液晶ライトバルブ。1. An optical writing type liquid crystal light valve in which an image writing means using light such as a laser beam and an LED, a photoconductive layer, a light reflecting layer, a liquid crystal alignment layer, a liquid crystal layer, and a voltage applying means are formed. An optical writing type liquid crystal light valve, wherein the photoconductivity of the photoconductive layer is distributed symmetrically in the plane and increases with distance from the center of the plane.
ステップ状であることを特徴とする請求項１記載の光書
込型液晶ライトバルブ。2. The optically writable liquid crystal light valve according to claim 1, wherein the central symmetry distribution of the photoconductivity of the photoconductive layer is stepwise.
ａ−Si:Hであることを特徴とする請求項１あるいは２記
載の光書込型液晶ライトバルブ。3. The optical writing type liquid crystal light valve according to claim 1, wherein the photoconductive layer used in the liquid crystal light valve is a-Si: H.
反射率と印加電圧との間に双安定性メモリを有する強誘
電性液晶であることを特徴とする請求項1,2あるいは３
記載の光書込型液晶ライトバルブ。4. The liquid crystal layer used in the liquid crystal light valve is a ferroelectric liquid crystal having a bistable memory between a light reflectance and an applied voltage.
The optical writing type liquid crystal light valve described.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15803889A JPH0754385B2 (en) | 1989-06-19 | 1989-06-19 | Optical write type liquid crystal light valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15803889A JPH0754385B2 (en) | 1989-06-19 | 1989-06-19 | Optical write type liquid crystal light valve |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0321926A JPH0321926A (en) | 1991-01-30 |
| JPH0754385B2 true JPH0754385B2 (en) | 1995-06-07 |
Family
ID=15662923
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15803889A Expired - Fee Related JPH0754385B2 (en) | 1989-06-19 | 1989-06-19 | Optical write type liquid crystal light valve |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0754385B2 (en) |
-
1989
- 1989-06-19 JP JP15803889A patent/JPH0754385B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0321926A (en) | 1991-01-30 |
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