JP2002286934A - Optical filter, imaging unit using the same and imaging appliance using the same - Google Patents
Optical filter, imaging unit using the same and imaging appliance using the sameInfo
- Publication number
- JP2002286934A JP2002286934A JP2001093760A JP2001093760A JP2002286934A JP 2002286934 A JP2002286934 A JP 2002286934A JP 2001093760 A JP2001093760 A JP 2001093760A JP 2001093760 A JP2001093760 A JP 2001093760A JP 2002286934 A JP2002286934 A JP 2002286934A
- Authority
- JP
- Japan
- Prior art keywords
- optical filter
- image pickup
- birefringent
- transmittance
- light
- 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.)
- Pending
Links
Landscapes
- Optical Filters (AREA)
- Polarising Elements (AREA)
- Transforming Light Signals Into Electric Signals (AREA)
- Color Television Image Signal Generators (AREA)
- Blocking Light For Cameras (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明はデジタルカメラや携
帯端末などの撮像機器と、これらに用いる光学フィルタ
及び撮像装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device such as a digital camera or a portable terminal, and an optical filter and an image pickup device used for the same.
【０００２】[0002]
【従来の技術】一般的に画像撮像素子として用いられる
ＣＣＤ(Ｃｈａｒｇｅ ＣｏｕｐｌｅｄＤｅｖｉｃｅ)や
ＣＭＯＳ(Ｃｏｍｐｌｅｍｅｎｔａｒｙ Ｍｅｔａｌ Ｏ
ｘｉｄｅ Ｓｅｍｉｃｏｎｄｕｃｔｏｒ)等は周期的に画
素が配列されている。これらの素子を用いた場合、撮像
素子のサンプリング周波数の１／２以上の高周波成分が
含まれると偽信号として取り込まれモアレ等の問題を発
生させる。このため図３に示すように、パッケージ１１
に収納されてカバーガラス１４で封止された撮像素子１
２と対物レンズ８との間に、複屈折板や回折格子等から
なる光学フィルタ１３がおかれている(特開平１−２５
４９１２号、特開平３−２８４７１４号公報参照)。2. Description of the Related Art A CCD (Charge Coupled Device) and a CMOS (Complementary Metal O) generally used as an image pickup device are used.
Pixels are periodically arranged in an element such as “xide semiconductor”. When these elements are used, if a high frequency component equal to or more than 以上 of the sampling frequency of the image pickup element is included, it is captured as a false signal and causes a problem such as moire. Therefore, as shown in FIG.
Image sensor 1 housed in a box and sealed with cover glass 14
An optical filter 13 composed of a birefringent plate, a diffraction grating, or the like is provided between the lens 2 and the objective lens 8 (Japanese Patent Laid-Open No. 1-25 / 1990).
4912, and JP-A-3-284714).
【０００３】また、撮像装置の小型化により、図４
（ａ），（ｂ）に示すように撮像素子１２を収納するパ
ッケージ１１のカバーガラスに光学フィルタ１３を設置
することもある(特開平１−１２９６７１号公報、特開
平５−２５７０８６号、特開２０００−４０８１３号公
報参照)。[0003] In addition, due to the miniaturization of the imaging apparatus, FIG.
As shown in FIGS. 1A and 1B, an optical filter 13 may be provided on a cover glass of a package 11 containing an image pickup device 12 (Japanese Patent Application Laid-Open Nos. 1-126971, 5-257086, and 5-27086). 2000-40813).
【０００４】上記光学フィルタ１３として、一般的に回
折格子は精密な形状を形成する事が困難であり、また焦
点の関係上、実装位置に自由度が持たせられないことか
ら、複屈折板が好まれる。また、この複屈折板の材質と
しては水晶が一般的に用いられる。In general, it is difficult to form a precise shape of the diffraction grating as the optical filter 13 and the mounting position is not given a degree of freedom due to the focal point. Preferred. Quartz is generally used as a material of the birefringent plate.
【０００５】この光学フィルタ１３は、図５（ａ），
（ｂ）に示すように水晶からなる複屈折板１６，１８と
１／４波長板１７を積層し、これらの間に赤外線遮断層
１９としてガラス板が挟まれていたり、コートを施した
りしている。[0005] This optical filter 13 is shown in FIG.
As shown in (b), birefringent plates 16 and 18 made of quartz and a quarter-wave plate 17 are laminated, and a glass plate is sandwiched or coated as an infrared shielding layer 19 between them. I have.
【０００６】通常これらの撮像素子１２を用いる場合、
撮像素子１２が赤外光に対し感度がよいことから取り込
まれた画像は一般的に赤味を帯びてしまうため、ある範
囲で赤外光を遮断する必要があり、図５（ａ），（ｂ）
に示すように赤外線遮断層１９を配置している。Normally, when these image pickup devices 12 are used,
Since the image taken in because the image sensor 12 has high sensitivity to infrared light generally has a reddish tint, it is necessary to block the infrared light in a certain range. b)
The infrared shielding layer 19 is disposed as shown in FIG.
【０００７】[0007]
【発明が解決しようとする課題】現在、これら撮像素子
を用いた装置ではさらに小型・薄板化が望まれている。At present, it is desired to further reduce the size and thickness of an apparatus using such an image sensor.
【０００８】しかし、水晶からなる複屈折板１６，１８
での光学フィルタ１３では複屈折が小さいため薄板化が
困難であった。薄板化は複屈折の大きな材料により可能
となるが、その材料としてルチル（ＴｉＯ2）や方解石
（ＣａＣＯ3）等を用いると、品質の安定性、供給の安
定性、価格、大きさ等の点で問題があった。However, birefringent plates 16 and 18 made of quartz are used.
It was difficult to make the optical filter 13 thinner because of low birefringence. Although thinning is possible with a material having a large birefringence, if rutile (TiO 2 ) or calcite (CaCO 3 ) is used as the material, the quality stability, supply stability, price, size, etc. There was a problem.
【０００９】[0009]
【課題を解決するための手段】本発明ではニオブ酸リチ
ウム単結晶からなる複屈折板を光学フィルタに用いるこ
とで小型・薄板化を図るとともに、このニオブ酸リチウ
ム単結晶からなる複屈折板に可視光域４００〜５５０ｎ
ｍでの透過率８５％以上で赤外光域７２５〜１０００ｎ
ｍでの透過率１５％以下の赤外線遮断層を積層したこと
を特徴とする。According to the present invention, a birefringent plate made of a single crystal of lithium niobate is used for an optical filter to reduce the size and thickness of the plate. Light range 400-550n
m is at least 85% and the infrared light range is 725 to 1000 n.
An infrared shielding layer having a transmittance of 15% or less at m is laminated.
【００１０】また本発明は、ニオブ酸リチウム単結晶か
らなる複屈折板を複数枚積層させた構造とし、少なくと
も３枚用いて各複屈折板の光軸投影方向を４５度乃至９
０度にして、光を正方もしくは長方分離して画素ピッチ
に合わした光学フィルタとしたことを特徴とする。さら
に、この複数枚積層させた複屈折板の少なくとも１枚を
水晶に置き換えたり、あるいは１／４波長板に置き換え
ても分離効果は得られる。Further, the present invention has a structure in which a plurality of birefringent plates made of a single crystal of lithium niobate are laminated, and the optical axis projection direction of each birefringent plate is 45 to 9 using at least three birefringent plates.
The optical filter is characterized in that the light is separated into a square or a rectangle by setting the angle to 0 degrees, and the optical filter is adjusted to the pixel pitch. Further, even if at least one of the plurality of laminated birefringent plates is replaced with quartz or a quarter-wave plate, the separation effect can be obtained.
【００１１】さらに本発明は、上記赤外線遮断層として
Ｐ−Ｖ値が１０％以内であり、光の入射角度２０度以内
における透過率の半値波長の変動が±１５ｎｍ以下とす
る膜を付けることで、更に小型・薄板化を図るようにし
たものである。Further, according to the present invention, the infrared ray blocking layer is provided with a film having a PV value within 10% and a variation in a half-value wavelength of a transmittance within ± 20 nm within an incident angle of light of ± 15 nm or less. In addition, it is intended to further reduce the size and thickness.
【００１２】また本発明は、上記複屈折板にそれぞれ接
する物に対しての反射防止膜を施すことで透過率を向上
させ、光学フィルタ全体の可視光域４００〜５５０ｎｍ
での透過率を８５％以上とした物である。Further, according to the present invention, the transmittance is improved by applying an antireflection film to an object in contact with each of the birefringent plates, and the visible light range of the entire optical filter is 400 to 550 nm.
The transmittance was set to 85% or more.
【００１３】さらに本発明は、上記光学フィルタを撮像
素子の収納用パッケージに備えることで撮像装置の小型
・薄板化を図るようにしたものである。Further, in the present invention, by providing the above-mentioned optical filter in a package for accommodating an image pickup device, the size and thickness of the image pickup device can be reduced.
【００１４】また本発明は、上記光学フィルタをパッケ
ージに接合するための接合剤として紫外線硬化型などの
温度が上がらない物を用いたり、加熱を必要とする接合
剤においてはニオブ酸リチウム単結晶に近似した８×１
０-5〜３×１０-6／℃の熱膨張係数を有する物にして割
れを防ぐようにしたものである。またニオブ酸リチウム
単結晶からなる複屈折板の軸方位に応じて数種の接合剤
を同時に用いて接合したり、接合工程でのニオブ酸リチ
ウム単結晶内での温度差を３０度以内にすることで割れ
を防ぐようにしたものである。The present invention also relates to a bonding agent for bonding the optical filter to a package, such as a UV-curable bonding agent which does not rise in temperature, or a bonding agent requiring heating, which is made of lithium niobate single crystal. Approximate 8 × 1
It has a thermal expansion coefficient of 0 -5 to 3 × 10 -6 / ° C. to prevent cracking. In addition, several types of bonding agents are simultaneously used in accordance with the axial orientation of the birefringent plate made of lithium niobate single crystal, or the temperature difference in the lithium niobate single crystal in the bonding step is kept within 30 degrees. This is to prevent cracking.
【００１５】[0015]
【発明の実施の形態】本発明の光学フィルタを図１に示
す。FIG. 1 shows an optical filter according to the present invention.
【００１６】ニオブ酸リチウム単結晶からなる複屈折板
１，２，３と赤外線遮断層４を図１のように積層させて
光学フィルタ９を構造する。この赤外線遮断層４の接合
場所は複屈折板１，２，３の表面、もしくは複数の複屈
折板１，２，３の間であっても良い。また、この赤外線
遮断層４は固体でも薄膜でも良い。An optical filter 9 is formed by laminating birefringent plates 1, 2, 3 made of lithium niobate single crystal and an infrared shielding layer 4 as shown in FIG. The bonding location of the infrared shielding layer 4 may be on the surface of the birefringent plates 1, 2, 3 or between the plurality of birefringent plates 1, 2, 3. Further, the infrared shielding layer 4 may be a solid or a thin film.
【００１７】詳細を後述するように図２に示すＣＣＤ及
びＣＭＯＳ等の撮像素子１２は周期的に画素が配列さ
れ、それに色フィルターが周期的に付けられているの
で、上記のように少なくとも３枚の複屈折板１，２，３
を用いて、互いの結晶光軸投影方向を４５度乃至９０度
の角度をもって交差させて、入射光を正方または長方の
４点に均等な光に分離させることで、その撮像素子１２
の画素ピッチに対応した光学フィルタ９とする事ができ
る。As will be described later in detail, the image pickup device 12 such as a CCD and a CMOS shown in FIG. 2 has pixels arranged periodically and color filters are periodically attached thereto. Birefringent plates 1, 2, 3
Is used to intersect the crystal optical axis projection directions at an angle of 45 ° to 90 ° to separate the incident light into four light points of a square or a rectangular shape, so that the image sensor 12
The optical filter 9 corresponding to the pixel pitch can be obtained.
【００１８】また、複屈折板１，２，３のうち、中間の
複屈折板２を１／４波長板に置き換えた構成でも良い。
この１／４波長板は水晶やニオブ酸リチウム単結晶等を
結晶方位や厚みを設計して用いる。The birefringent plates 1, 2, and 3 may be configured such that the intermediate birefringent plate 2 is replaced with a quarter-wave plate.
This quarter-wave plate is made of quartz, lithium niobate single crystal, or the like with its crystal orientation and thickness designed.
【００１９】さらに複屈折板１，２，３の少なくとも１
枚を水晶に置き換えても、同様の光の分離効果を得るこ
とができる。Furthermore, at least one of the birefringent plates 1, 2, 3
The same light separating effect can be obtained even if the sheet is replaced with quartz.
【００２０】さらに、図１では３枚の複屈折板を用いた
が、１枚のニオブ酸リチウム単結晶からなる複屈折板１
のみでも光学フィルタ９として用いることができる。赤
外線遮断層４は可視光域である波長４００〜５５０ｎｍ
の光を透過して、赤外光域である波長７２５〜１０００
ｎｍの光をカットする性質を持つ。この可視光域４００
〜５５０ｎｍでの透過率はそのまま撮像素子で取り込ま
れた映像の明るさに影響するため高い方が好ましく、ま
た、赤外光域７２５〜１０００ｎｍでの透過率は映像の
赤味に大きく影響するため低い方が好ましく、中間の５
５０〜７２５ｎｍでは連続的にシャープに透過率を減少
させることが好ましい。特に可視光域である波長４００
〜５５０ｎｍでの透過率は８５％以上で、赤外光域であ
る波長７２５〜１０００ｎｍでの透過率が１５％以下で
あるものを用い、さらに透過率５０％の半値波長が６３
５±１５ｎｍになる様にした状態で連続的に波長域につ
ながったものを用いれば、得られた映像は人の感度に近
い状態で好ましい。Further, in FIG. 1, three birefringent plates are used, but one birefringent plate 1 made of lithium niobate single crystal is used.
Only the optical filter 9 can be used. The infrared blocking layer 4 has a wavelength of 400 to 550 nm in the visible light range.
At a wavelength of 725 to 1000, which is an infrared light range.
It has the property of cutting light of nm. This visible light region 400
The transmittance at は 550 nm directly affects the brightness of the image captured by the image sensor, and is therefore preferably high. The transmittance in the infrared light range of 725 to 1000 nm greatly affects the redness of the image. Lower is preferable, middle 5
It is preferable to continuously and sharply reduce the transmittance at 50 to 725 nm. In particular, a wavelength of 400 in the visible light range.
The transmittance at 85 to 550 nm is 85% or more, and the transmittance at a wavelength of 725 to 1000 nm, which is an infrared light region, is 15% or less.
If an image which is continuously connected to the wavelength region in a state of 5 ± 15 nm is used, the obtained image is preferable in a state close to human sensitivity.
【００２１】また、被写体からの光は光学フィルタ９の
垂直方向に対して２０度以内で入射されるため、その範
囲で分光透過率の変動が大きくなると量産時に個々の透
過率特性にあったデジタル信号処理が必要になり、大変
手間を取る。そのため入射角度２０度以内での透過率の
半値波長の変動は小さいことが好ましく、±１５ｎｍ以
下であることが望まれる。Also, since light from the subject is incident within 20 degrees with respect to the vertical direction of the optical filter 9, if the variation of the spectral transmittance becomes large within that range, the digital light having the individual transmittance characteristics during mass production is obtained. It requires signal processing and takes a lot of time. Therefore, it is preferable that the change in the half-value wavelength of the transmittance within the incident angle of 20 degrees is small, and it is desired that the change is ± 15 nm or less.
【００２２】ただし、赤外線遮断層４が薄膜の場合はニ
オブ酸リチウム単結晶からなる複屈折板１，２，３の屈
折率が大きいため、図６に従来の薄膜として示すように
可視光域４００〜６５０ｎｍで数カ所に及び透過率がお
ちるリップルが発生する事になる。これを防止するため
には、赤外線遮断層４として数層にわたり酸化チタン
（ＴｉＯ2）等の高屈折材と酸化珪素（ＳｉＯ2）、弗化
マグネシウム（ＭｇＦ）等の低屈折材からなる薄膜を順
番に積層して４００〜５５０ｎｍでの透過率を８５％以
上にして、そのＰ−Ｖ値を１０％以下にすることが好ま
しい。また、透過率５０％の半値波長を６２５±２５ｎ
ｍで赤外光域７２５〜１０００ｎｍでの透過率を１５％
以下にしたシャープカットな赤外線遮断層４を構成する
ことがさらに好ましい。成膜の方法は蒸着法、スパッタ
法等で可能である。However, when the infrared shielding layer 4 is a thin film, the birefringent plates 1, 2, and 3 made of lithium niobate single crystal have a large refractive index. Therefore, as shown in FIG. Ripple whose transmittance falls in several places at up to 650 nm is generated. To prevent this, titanium oxide over several layers as an infrared blocking layer 4 (TiO 2) high refractive material and silicon oxide, such as (SiO 2), a thin film made of a low refractive material such as magnesium fluoride (MgF) It is preferable that the layers are sequentially laminated so that the transmittance at 400 to 550 nm is 85% or more and the PV value is 10% or less. Further, the half-value wavelength of the transmittance of 50% is 625 ± 25n.
15% in the infrared light range from 725 to 1000 nm
It is more preferable to form a sharp-cut infrared shielding layer 4 described below. The film can be formed by a vapor deposition method, a sputtering method, or the like.
【００２３】また、複屈折板１，２，３や赤外線遮断層
４の各主面にそれぞれの接する物質に対する反射防止膜
５，６，７を形成することで、図７に示すように光学フ
ィルタ９全体の可視光域４００〜５５０ｎｍでの透過率
を８５％以上にすることができる。Further, by forming antireflection films 5, 6, 7 for the substances in contact with the respective main surfaces of the birefringent plates 1, 2, 3 and the infrared shielding layer 4, as shown in FIG. 9 can have a transmittance of 85% or more in the visible light region of 400 to 550 nm.
【００２４】光学フィルタ９として構成するニオブ酸リ
チウム単結晶からなる複屈折板１，２，３および赤外線
遮断層４の接合には透光性接着剤を用いたり、機械的な
接合でも可能である。The birefringent plates 1, 2, 3 made of lithium niobate single crystal constituting the optical filter 9 and the infrared shielding layer 4 can be joined by using a translucent adhesive or by mechanical joining. .
【００２５】こうして得た本発明の光学フィルタ９を撮
像装置に用いた例を図２に示す。FIG. 2 shows an example in which the optical filter 9 of the present invention thus obtained is used in an image pickup apparatus.
【００２６】ＣＣＤまたはＣＭＯＳ等の撮像素子１２が
パッケージ１１に収納されており、その撮像素子１２の
受光面側にパッケージ１１の開口部があり、そこには透
光性があり撮像素子１２を保護し封止するためのカバー
ガラスと兼用して、図１に示す光学フィルタ９を用い
て、接合剤１０で接合する。An image pickup device 12 such as a CCD or a CMOS is housed in a package 11, and an opening portion of the package 11 is provided on a light receiving surface side of the image pickup device 12, and has a light transmitting property to protect the image pickup device 12. The optical filter 9 shown in FIG. 1 is used as a cover glass for sealing, and then joined with a bonding agent 10.
【００２７】一般にＣＣＤ及びＣＭＯＳ等の撮像素子１
２は周期的に画素が配列され、それに色フィルターが周
期的に付けられているので、特に複屈折板１，２，３を
少なくとも３枚用いて、互いの結晶光軸投影方向を４５
度乃至９０度の角度をもって交差させて、入射光を正方
または長方の４点に均等な光に分離させることで、その
撮像素子１２の画素ピッチに対応した光学フィルタ９を
備えることにより、従来、光学フィルタ９が置かれてい
たスペースが削減する事ができる。Generally, an image pickup device 1 such as a CCD and a CMOS
Reference numeral 2 denotes that pixels are periodically arranged and color filters are periodically attached thereto. In particular, at least three birefringent plates 1, 2, 3 are used, and the crystal optical axis projection directions are set to 45.
By intersecting at an angle of degrees to 90 degrees and separating incident light into four lights of square or rectangular shape, the optical filter 9 corresponding to the pixel pitch of the image sensor 12 is provided. In addition, the space where the optical filter 9 is placed can be reduced.
【００２８】上記接合剤１０としては、ニオブ酸リチウ
ム単結晶と熱膨張が近似した接着剤、ガラス材、樹脂材
等を用い、特に熱膨張係数８×１０-5〜３×１０-6／℃
程度の熱硬化接合剤が好ましい。As the bonding agent 10, an adhesive, a glass material, a resin material, or the like whose thermal expansion is similar to that of the lithium niobate single crystal is used, and particularly, the thermal expansion coefficient is 8 × 10 -5 to 3 × 10 -6 / ° C.
A degree of thermosetting bonding agent is preferred.
【００２９】また、本発明で複屈折板１，２，３として
用いるニオブ酸リチウム単結晶は、表１のように光軸投
影方向とそれに垂直方向では熱膨張が異なるため、それ
ぞれの方向で熱膨張の近似した複数の接合剤１０を用い
ることが好ましい。The lithium niobate single crystal used as the birefringent plates 1, 2, and 3 in the present invention has different thermal expansions in the optical axis projection direction and the perpendicular direction as shown in Table 1, so that the thermal expansion in each direction is different. It is preferable to use a plurality of bonding agents 10 having similar expansions.
【００３０】[0030]
【表１】 [Table 1]
【００３１】あるいは、接合剤１０として熱がかからな
い紫外線硬化型の接着剤を用いることもできる。Alternatively, an ultraviolet-curing adhesive to which heat is not applied can be used as the bonding agent 10.
【００３２】また、接合時にはニオブ酸リチウム単結晶
内で部分的に大きな温度差があるとクラックが発生しや
すくなるため、単結晶内での温度差が３０度以下となる
ようにして製造することが好ましい。Further, at the time of bonding, cracks are likely to occur if there is a large temperature difference in the lithium niobate single crystal, so that the temperature difference within the single crystal should be 30 ° C. or less. Is preferred.
【００３３】このように、本発明のニオブ酸リチウム単
結晶からなる複屈折板１，２，３を用いて赤外線遮断層
膜４を備えた光学フィルタ９を、撮像素子１２収納用パ
ッケージ１１に設置することで、大幅に光学系の距離の
短縮が可能になり、撮像装置の小型、薄板化ができる。As described above, the optical filter 9 provided with the infrared shielding layer film 4 using the birefringent plates 1, 2, 3 made of the lithium niobate single crystal of the present invention is installed in the package 11 for accommodating the image sensor 12. By doing so, the distance of the optical system can be greatly reduced, and the size and thickness of the imaging device can be reduced.
【００３４】そのため、このような本発明の光学フィル
タや撮像装置をデジタルカメラなどの撮像機器に用いれ
ば、小型、薄板化することができる。Therefore, if such an optical filter or an image pickup apparatus of the present invention is used for an image pickup apparatus such as a digital camera, it is possible to reduce the size and thickness of the apparatus.
【００３５】[0035]
【実施例】結晶光軸面から４５度傾けたニオブ酸リチウ
ム単結晶からなる４インチサイズの複屈折板を３枚用い
て、図１の光学フィルタ９を構成する。１枚目の複屈折
板１は基板厚み０．３１ｍｍにして、仮にその基板内の
光軸投影方向線を０度とした場合、２枚目、３枚目の複
屈折板２，３の光軸投影方向線を＋４５度、−４５度に
する。その２枚目、３枚目の複屈折板２，３の厚みはそ
れぞれ０．２２ｍｍとした。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The optical filter 9 of FIG. 1 is constituted by using three 4-inch birefringent plates made of a single crystal of lithium niobate inclined at 45 degrees from the crystal optical axis plane. Assuming that the first birefringent plate 1 has a substrate thickness of 0.31 mm and the optical axis projection direction line in the substrate is 0 °, the light of the second and third birefringent plates 2 and 3 The axis projection direction lines are set to +45 degrees and -45 degrees. The thickness of each of the second and third birefringent plates 2 and 3 was 0.22 mm.
【００３６】それぞれの複屈折板１，２，３は接する物
に応じた反射防止膜５，６、７を両面に施す。１枚目の
複屈折板１の片面には空気に対しての反射防止膜５を施
し、他面には反射防止膜７と赤外線遮断層４の膜とを施
した。赤外遮断層４の膜は酸化チタンと酸化珪素の薄膜
を順番に２０層以上積層して、可視光域４００〜５５０
ｎｍでの透過率が８５％以上で赤外光域７２５〜１００
０ｎｍでの透過率が１５％以下で可視光域４００〜５５
０ｎｍでの透過率のＰ−Ｖ値が１０％以下の特性を出し
た。Each of the birefringent plates 1, 2, and 3 is provided with antireflection films 5, 6, and 7 on both surfaces according to the objects in contact. One surface of the first birefringent plate 1 was provided with an antireflection film 5 for air, and the other surface was provided with an antireflection film 7 and a film of an infrared shielding layer 4. The film of the infrared blocking layer 4 is formed by sequentially laminating 20 or more thin films of titanium oxide and silicon oxide in a visible light range of 400 to 550.
with a transmittance of 85% or more in the infrared region of 725 to 100
When the transmittance at 0 nm is 15% or less and the visible light range is 400 to 55
A characteristic was obtained in which the PV value of the transmittance at 0 nm was 10% or less.
【００３７】２枚目の複屈折板２は両面に屈折率１．５
前後の透過性接着剤に対しての反射防止膜６を施し、３
枚目の複屈折板３には片面に前記同様の接着剤に対する
反射防止膜６を施し、他面には空気に対する反射防止膜
５を施した。The second birefringent plate 2 has a refractive index of 1.5 on both sides.
An antireflection film 6 is applied to the front and rear transparent adhesives,
The second birefringent plate 3 was provided with an anti-reflection film 6 for the same adhesive as described above on one surface, and an anti-reflection film 5 for air on the other surface.
【００３８】赤外線遮断層４の膜および反射防止膜５，
６，７は蒸着法で被着したが、スパッタ法等でも可能で
ある。 これらの複屈折板１，２，３を順番に光軸投影
方向を前記角度に正確に保ちながら、前記の接着剤にて
接着固定した。The film of the infrared shielding layer 4 and the antireflection film 5,
Although Nos. 6 and 7 are deposited by a vapor deposition method, they can be formed by a sputtering method or the like. These birefringent plates 1, 2, and 3 were bonded and fixed with the above-mentioned adhesive while keeping the optical axis projection direction at the above-described angle accurately.
【００３９】こうして得られた光学フィルタ９の分光透
過率は図６，図７に示すように可視光域４００〜５５０
ｎｍでの透過率が８５％以上でリップルの小さい特性に
改善された。The spectral transmittance of the optical filter 9 thus obtained has a visible light range of 400 to 550 as shown in FIGS.
When the transmittance in nm was 85% or more, the characteristics were improved with small ripple.
【００４０】透過性接着剤の屈折率は特に限定はなく、
その屈折率に応じた反射防止膜を施せばよい。 接着剤
の硬化方法も紫外線硬化、熱硬化等で限定はないが、信
頼性や複屈折板の熱特性を考慮すると紫外線硬化型の接
着剤が好ましい。The refractive index of the transparent adhesive is not particularly limited.
What is necessary is just to apply an antireflection film according to the refractive index. The method of curing the adhesive is not limited to ultraviolet curing, thermal curing, or the like, but an ultraviolet-curable adhesive is preferable in consideration of reliability and thermal characteristics of the birefringent plate.
【００４１】こうして得られたニオブ酸リチウム単結晶
からなる３枚の複屈折板と赤外線遮断層を積層した光学
フィルターをダイシング加工により３０×３０程度へチ
ップ化する。The optical filter obtained by laminating the thus obtained three birefringent plates made of lithium niobate single crystal and an infrared shielding layer is formed into chips of about 30 × 30 by dicing.
【００４２】この光学フィルタは可視光域での透過率で
９０％以上を保ち、正方に約１２μｍのピッチで４点に
分離する。This optical filter maintains a transmittance of 90% or more in the visible light region, and separates the light into four points at a pitch of about 12 μm.
【００４３】このチップを図２のようにＣＣＤ撮像素子
１２が収納されたパッケージ１１の受光部側のカバーガ
ラスとして接合する。This chip is joined as a cover glass on the light receiving section side of the package 11 in which the CCD image pickup device 12 is housed as shown in FIG.
【００４４】接合方法は紫外線硬化型の接着剤を用いて
光学フィルター全周を接着する。他に熱硬化接着剤、樹
脂、ガラス等を用いた接合も可能だが、加熱する場合
は、その熱膨張係数をニオブ酸リチウム単結晶に類似し
た物を選択する必要がある。また、光学フィルタを積層
するときに用いた接着剤の熱特性も考慮する必要があ
る。The bonding method is to bond the entire circumference of the optical filter using an ultraviolet curing adhesive. In addition, bonding using a thermosetting adhesive, resin, glass, or the like is also possible, but when heating, it is necessary to select a material having a coefficient of thermal expansion similar to that of lithium niobate single crystal. It is also necessary to consider the thermal characteristics of the adhesive used when laminating the optical filters.
【００４５】こうして得られた光学フィルタを一体にし
た撮像装置を用いた光学系は、従来のフィルタが分離し
ている撮像装置の光学系に比べ設置スペースが約１／３
以下の厚みになり、水晶の光学フィルタを一体にした撮
像装置の光学系の設置スペースの約１／２の厚みにする
事が可能になる。An optical system using an image pickup device integrated with an optical filter obtained in this way requires about one-third the installation space as compared with the optical system of an image pickup device in which a conventional filter is separated.
The thickness is as follows, and it is possible to reduce the thickness to about ス ペ ー ス of the installation space of the optical system of the imaging apparatus in which the quartz optical filter is integrated.
【００４６】[0046]
【発明の効果】本発明によれば、ニオブ酸リチウム単結
晶からなる複屈折板を用いて、光学フィルタを構成し、
それを撮像素子が収納されるパッケージのカバーとして
用いることで小型・薄板化された撮像装置が可能にな
る。また、これを実現するに当たり光学フィルタを破損
させない製造方法と、ニオブ酸リチウム単結晶に対し要
求される特性を持った赤外線遮断層の膜の製造を可能に
する。According to the present invention, an optical filter is constituted by using a birefringent plate made of lithium niobate single crystal,
By using it as a cover of a package in which an image sensor is housed, a small and thin imaging device can be realized. Further, in realizing this, a manufacturing method that does not damage the optical filter and a film of an infrared shielding layer having characteristics required for a lithium niobate single crystal can be manufactured.
【図１】本発明の光学フィルタを示す図である。FIG. 1 is a diagram showing an optical filter of the present invention.
【図２】本発明の撮像装置を示す断面図である。FIG. 2 is a cross-sectional view illustrating the imaging device of the present invention.
【図３】従来の撮像装置を示す断面図である。FIG. 3 is a cross-sectional view illustrating a conventional imaging device.
【図４】（ａ）（ｂ）は従来の撮像装置を示す断面図で
ある。FIGS. 4A and 4B are cross-sectional views showing a conventional imaging device.
【図５】（ａ）（ｂ）は従来の光学フィルタを示す図で
ある。FIGS. 5A and 5B are diagrams showing a conventional optical filter.
【図６】光学フィルタにおける赤外線遮断層の光透過率
を示した図である。FIG. 6 is a diagram showing the light transmittance of an infrared shielding layer in the optical filter.
【図７】本発明の光学フィルタにおける光透過率を示し
た図である。FIG. 7 is a diagram showing light transmittance in the optical filter of the present invention.
１：複屈折板 ２：複屈折板 ３：複屈折板 ４：赤外線遮断層 ５：反射防止膜 ６：反射防止膜 ７：反射防止膜 ８：レンズ ９：光学フィルタ １０：接合剤 １１：パッケージ １２：撮像素子 １３：光学フィルタ １４：カバーガラス １５：接合剤 １６：複屈折板 １７：複屈折板 １８：複屈折板 １９：赤外線遮断層 ２０：反射防止膜 1: birefringent plate 2: birefringent plate 3: birefringent plate 4: infrared blocking layer 5: antireflection film 6: antireflection film 7: antireflection film 8: lens 9: optical filter 10: bonding agent 11: package 12 : Image sensor 13: Optical filter 14: Cover glass 15: Bonding agent 16: Birefringent plate 17: Birefringent plate 18: Birefringent plate 19: Infrared shielding layer 20: Antireflection film
Claims (15)
に、可視光域である波長４００〜５５０ｎｍの光の透過
率が８５％以上で、赤外光域である波長７２５〜１００
０ｎｍの光の透過率が１５％以下の赤外線遮断層を積層
したことを特徴とする光学フィルタ。1. A birefringent plate made of a single crystal of lithium niobate has a transmittance of 85% or more of light having a wavelength of 400 to 550 nm, which is a visible light region, and a wavelength of 725 to 100, which is an infrared light region.
An optical filter comprising an infrared shielding layer having a transmittance of 0 nm light of 15% or less laminated.
面または間に上記赤外線遮断層を積層したことを特徴と
する光学フィルタ。2. An optical filter comprising a plurality of the birefringent plates laminated, and the infrared shielding layer laminated on the outermost surface or between the birefringent plates.
各板の光軸投影方向が４５度乃至９０度になるようにし
て、透過光を正方もしくは長方分離させることを特徴と
する請求項２記載の光学フィルタ。3. At least three birefringent plates are laminated,
The optical filter according to claim 2, wherein the transmitted light is separated into a square or a rectangle so that the optical axis projection direction of each plate is 45 to 90 degrees.
も１枚を水晶に置き換えたことを特徴とする請求項２ま
たは３記載の光学フィルタ。4. The optical filter according to claim 2, wherein at least one of said plurality of laminated birefringent plates is replaced with quartz.
も１枚を１／４波長板に置き換えたことを特徴とする請
求項２乃至４のいずれかに記載の光学フィルタ。5. The optical filter according to claim 2, wherein at least one of the plurality of laminated birefringent plates is replaced with a quarter-wave plate.
４００〜５５０ｎｍの光の透過率のＰ−Ｖ（Ｐｅａｋ
ａｎｄ Ｖａｌｌｅｙ）値が１０％以下であることを特
徴とする請求項１乃至５のいずれかに記載の光学フィル
タ。6. The infrared shielding layer has a PV (Peak) having a transmittance of light having a wavelength of 400 to 550 nm, which is a visible light region.
The optical filter according to any one of claims 1 to 5, wherein a value of (and Valley) is 10% or less.
以内における透過率の半値波長の変動が±１５ｎｍ以下
であることを特徴とする請求項１乃至６のいずれかに記
載の光学フィルタ。7. The optical filter according to claim 1, wherein the infrared cutoff layer has a transmittance half-wavelength variation of ± 15 nm or less within a light incident angle of 20 degrees. .
ｍの光の透過率が８５％以上であることを特徴とする請
求項１乃至７のいずれかに記載の光学フィルタ。8. A wavelength of 400 nm to 550 n which is a visible light region.
The optical filter according to any one of claims 1 to 7, wherein a transmittance of light of m is 85% or more.
面の対面に、ニオブ酸リチウム単結晶からなる複屈折板
を備えたことを特徴とする撮像装置。9. An image pickup apparatus comprising: a birefringent plate made of a single crystal of lithium niobate on a surface opposite to a light receiving surface of an image pickup device housed in a package.
特徴とする請求項９記載の撮像装置。10. The imaging device according to claim 9, wherein a plurality of the birefringent plates are stacked.
光面の対面に請求項１乃至８のいずれかに記載の光学フ
ィルタを備えたことを特徴とする撮像装置。11. An image pickup apparatus comprising: the optical filter according to claim 1 on a surface opposite to a light receiving surface of an image pickup device housed in a package.
×１０-6／℃の熱膨張係数を有する接着剤を用いて、前
記複屈折板または光学フィルタをパッケージに接合した
ことを特徴とする請求項９乃至１１のいずれかに記載の
撮像装置。12. An ultraviolet curing adhesive or 8 × 10 -5 to 3
The imaging device according to any one of claims 9 to 11, wherein the birefringent plate or the optical filter is bonded to a package using an adhesive having a coefficient of thermal expansion of 10-6 / C.
屈折板の軸方位に対して、その熱膨張係数に合わせた複
数の接合剤を用いてパッケージに接合することを特徴と
する請求項９乃至１２のいずれかに記載の撮像装置。13. A package according to claim 9, wherein said birefringent plate made of lithium niobate single crystal is bonded to a package using a plurality of bonding agents corresponding to the thermal expansion coefficient of said birefringent plate. The imaging device according to any one of claims 12 to 12.
差が３０度以下になるようにしてパッケージに接合した
ことを特徴とする請求項９乃至１３のいずれかに記載の
撮像装置。14. The image pickup apparatus according to claim 9, wherein said image pickup device is joined to a package such that a temperature difference in said lithium niobate single crystal is 30 ° C. or less.
フィルタ、又は請求項９乃至１４のいずれかに記載の撮
像装置を用いたことを特徴とする撮像機器。15. An image pickup apparatus using the optical filter according to claim 1 or the image pickup apparatus according to claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001093760A JP2002286934A (en) | 2001-03-28 | 2001-03-28 | Optical filter, imaging unit using the same and imaging appliance using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001093760A JP2002286934A (en) | 2001-03-28 | 2001-03-28 | Optical filter, imaging unit using the same and imaging appliance using the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2002286934A true JP2002286934A (en) | 2002-10-03 |
Family
ID=18948057
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001093760A Pending JP2002286934A (en) | 2001-03-28 | 2001-03-28 | Optical filter, imaging unit using the same and imaging appliance using the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2002286934A (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006101120A (en) * | 2004-09-29 | 2006-04-13 | Nikon Corp | Solid-state imaging element and digital camera |
| JP2006139238A (en) * | 2004-11-09 | 2006-06-01 | Samsung Electronics Co Ltd | Optical module and its manufacturing method, back light assembly having optical module, and display device having back light assembly |
| JP2006222700A (en) * | 2005-02-09 | 2006-08-24 | Olympus Corp | Imaging device |
| JP2006317695A (en) * | 2005-05-12 | 2006-11-24 | Canon Inc | Optical device |
| JP2007043319A (en) * | 2005-08-01 | 2007-02-15 | Matsushita Electric Ind Co Ltd | Imaging apparatus and on-vehicle camera system using the same |
| JP2007110402A (en) * | 2005-10-13 | 2007-04-26 | Canon Inc | Imaging unit and imaging apparatus with same |
| JP2008042796A (en) * | 2006-08-10 | 2008-02-21 | Epson Toyocom Corp | Solid-state imaging element cover and imaging device |
| JP2008042797A (en) * | 2006-08-10 | 2008-02-21 | Epson Toyocom Corp | Solid-state imaging element cover and imaging device |
| JP2009153178A (en) * | 2002-09-17 | 2009-07-09 | Anteryon Bv | Camera device and method for manufacturing camera device and wafer scale package |
| WO2016175089A1 (en) * | 2015-04-28 | 2016-11-03 | 浜松ホトニクス株式会社 | Optical detection device |
-
2001
- 2001-03-28 JP JP2001093760A patent/JP2002286934A/en active Pending
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009153178A (en) * | 2002-09-17 | 2009-07-09 | Anteryon Bv | Camera device and method for manufacturing camera device and wafer scale package |
| JP2006101120A (en) * | 2004-09-29 | 2006-04-13 | Nikon Corp | Solid-state imaging element and digital camera |
| JP4687053B2 (en) * | 2004-09-29 | 2011-05-25 | 株式会社ニコン | Image sensor unit and digital camera |
| JP2006139238A (en) * | 2004-11-09 | 2006-06-01 | Samsung Electronics Co Ltd | Optical module and its manufacturing method, back light assembly having optical module, and display device having back light assembly |
| JP2006222700A (en) * | 2005-02-09 | 2006-08-24 | Olympus Corp | Imaging device |
| JP2006317695A (en) * | 2005-05-12 | 2006-11-24 | Canon Inc | Optical device |
| JP2007043319A (en) * | 2005-08-01 | 2007-02-15 | Matsushita Electric Ind Co Ltd | Imaging apparatus and on-vehicle camera system using the same |
| JP2007110402A (en) * | 2005-10-13 | 2007-04-26 | Canon Inc | Imaging unit and imaging apparatus with same |
| JP2008042797A (en) * | 2006-08-10 | 2008-02-21 | Epson Toyocom Corp | Solid-state imaging element cover and imaging device |
| JP2008042796A (en) * | 2006-08-10 | 2008-02-21 | Epson Toyocom Corp | Solid-state imaging element cover and imaging device |
| WO2016175089A1 (en) * | 2015-04-28 | 2016-11-03 | 浜松ホトニクス株式会社 | Optical detection device |
| JP2016211860A (en) * | 2015-04-28 | 2016-12-15 | 浜松ホトニクス株式会社 | Light detection device |
| CN113049100A (en) * | 2015-04-28 | 2021-06-29 | 浜松光子学株式会社 | Optical detection device |
| US11118972B2 (en) | 2015-04-28 | 2021-09-14 | Hamamatsu Photonics K.K. | Optical detection device having adhesive member |
| US11555741B2 (en) | 2015-04-28 | 2023-01-17 | Hamamatsu Photonics K.K. | Optical detection device having adhesive member |
| CN113049100B (en) * | 2015-04-28 | 2023-11-28 | 浜松光子学株式会社 | Light detection device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100705349B1 (en) | Solid state imaging device, semiconductor wafer and camera module | |
| US20050180010A1 (en) | Dielectric multilayer filter and its manufacturing method, and solid-state imaging device | |
| US20100044815A1 (en) | Cmos image sensor package and camera module using same | |
| WO2017126376A1 (en) | Image sensor, manufacturing method, and electronic device | |
| JP2006032886A (en) | Solid-state imaging device, its manufacturing method, and camera module | |
| JP2005043755A (en) | Optical multilayer filter, manufacturing method therefor, optical low-pass filter, and electronic equipment system | |
| WO2001065306A1 (en) | Optical device | |
| JP2013218245A (en) | Optical element, imaging device, camera, and manufacturing method of optical element | |
| JP2002286934A (en) | Optical filter, imaging unit using the same and imaging appliance using the same | |
| TWI352825B (en) | ||
| JP2010165939A (en) | Solid-state imaging device and method of manufacturing the same | |
| KR102314952B1 (en) | Imaging element, imaging device, and production device and method | |
| TW200303619A (en) | Solidstate image-taking apparatus | |
| JP2006011408A (en) | Optical element and optical equipment | |
| JP2000114502A (en) | Solid-state image pickup element | |
| JP2006091625A (en) | Optical low pass filter | |
| US20070153115A1 (en) | Image pickup device | |
| JP2006195373A (en) | Visibility correcting near infrared cut filter, and optical low pass filter and visibility correcting element using the same | |
| JP2008034502A (en) | Solid-state image sensing device cover and solid-state image sensing apparatus | |
| JPS61124901A (en) | Production of color separating filter | |
| JPH0516003B2 (en) | ||
| US20080129852A1 (en) | Image sensor, method of manufacturing the same, and camera module having the same | |
| JP4853157B2 (en) | Antireflection film, optical element, imaging device, and camera | |
| JP2000206325A (en) | Infrared ray cut filter and imaging device by using infrared ray cut filter | |
| JP2001324615A (en) | Spatial filter |