JPH03197920A - Polarized light source - Google Patents
Polarized light sourceInfo
- Publication number
- JPH03197920A JPH03197920A JP33664989A JP33664989A JPH03197920A JP H03197920 A JPH03197920 A JP H03197920A JP 33664989 A JP33664989 A JP 33664989A JP 33664989 A JP33664989 A JP 33664989A JP H03197920 A JPH03197920 A JP H03197920A
- Authority
- JP
- Japan
- Prior art keywords
- light
- beam splitter
- transparent plate
- light source
- polarizing beam
- 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
- 230000010287 polarization Effects 0.000 claims abstract description 36
- 239000004973 liquid crystal related substance Substances 0.000 claims description 14
- 210000002858 crystal cell Anatomy 0.000 claims description 9
- 210000004027 cell Anatomy 0.000 claims description 3
- 230000001788 irregular Effects 0.000 abstract 1
- 239000000463 material Substances 0.000 description 5
- 239000000758 substrate Substances 0.000 description 3
- 230000008033 biological extinction Effects 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 239000004988 Nematic liquid crystal Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910001507 metal halide Inorganic materials 0.000 description 1
- 150000005309 metal halides Chemical class 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000010445 mica Substances 0.000 description 1
- 229910052618 mica group Inorganic materials 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920006254 polymer film Polymers 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、ランダムな偏光特性をもった光ビームな直線
偏光に変える偏光光源装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polarized light source device that converts a light beam into linearly polarized light having random polarization characteristics.
［従来の技術］
例えば、液晶プロジェクタ−の光源として、また光源の
映り込みを嫌う照明（ガラス越しの照明や水面を通した
照明等）に直線偏光光源装置が役立つことが知られてい
る。[Prior Art] For example, it is known that a linearly polarized light source device is useful as a light source for a liquid crystal projector, or for illumination where reflection of the light source is avoided (lighting through glass, lighting through water, etc.).
この様な直線偏光光源装置としては、従来ランダムな偏
光特性の光源（例えばハロゲンランプ、キセノンランプ
、メタルハライドランプ等）と偏光板との組合わせが用
いられており、上記光源からの光を偏光板に通すことに
よって直線偏光が作られている。しかして、この際、偏
光板に入射する光のうち透過光の偏光面と垂直な偏光面
を持つ偏光成分がカットされるため、利用できる光量（
透過光量）は光源光の高々５０％である。Conventionally, such a linearly polarized light source device uses a combination of a light source with random polarization characteristics (for example, a halogen lamp, xenon lamp, metal halide lamp, etc.) and a polarizing plate, and the light from the light source is passed through the polarizing plate. Linearly polarized light is created by passing it through the At this time, among the light incident on the polarizing plate, the polarized component whose polarization plane is perpendicular to the polarization plane of the transmitted light is cut, so the amount of light that can be used (
The amount of transmitted light) is at most 50% of the light source light.
この様に、偏光板を用いた偏光光源装置では損失が大き
いという問題点がある。As described above, a polarized light source device using a polarizing plate has a problem in that the loss is large.
この損失を避ける方法として、先ず光源光を偏光ビーム
スプリッタ−で２つの直線偏光成分に分け、その一方の
偏光面を９０°回転させてから他方に合流させる方法が
考えられる。A conceivable method for avoiding this loss is to first split the light source light into two linearly polarized components using a polarizing beam splitter, rotate one of the polarized planes by 90 degrees, and then merge the two linearly polarized components into the other.
この考えを実現した例として、特開昭６３−１９７９１
３号公報、実開昭６３−１８７１０１号公報、特開昭６
３−２７１３１３号公報、実開昭６３−１５０９２２号
公報および特開昭６３−１６８６２２号公報に記載のも
のがある。An example of realizing this idea is Japanese Patent Laid-Open No. 63-19791
Publication No. 3, Japanese Utility Model Publication No. 187101/1983, Japanese Patent Application Publication No. 1983
There are those described in JP-A No. 3-271313, JP-A-63-150922, and JP-A-63-168622.
上記特開昭６３−１９７９１３号公報及び実開昭６３−
１８７１０１号公報に記載のものでは、偏光ビームスプ
リッタ−で分けられた２つの直線偏光成分のうちの一方
を２つの反射面で順次反射させて偏光面を回転させてい
る。この様に反射によって偏光面を回転させることは波
長依存性をもたない点で好ましい。しかしながら、反射
光の光路な確保するために装置のサイズが太き（なり、
好ましくない。The above-mentioned Japanese Unexamined Patent Publication No. 197913/1983 and Utility Model Application No. 63-
In the device described in Japanese Patent No. 187101, one of two linearly polarized light components separated by a polarizing beam splitter is sequentially reflected by two reflecting surfaces to rotate the plane of polarization. Rotating the plane of polarization by reflection in this manner is preferable because it does not have wavelength dependence. However, in order to ensure a clear optical path for the reflected light, the size of the device must be large.
Undesirable.
また、上記特開昭６３−２７１３１３号公報及び実開昭
６３−１５０９２２号公報に記載のものは、装置のサイ
ズが大きくなるため、かなり用途は制限される。Furthermore, the devices described in Japanese Patent Application Laid-Open No. 63-271313 and Japanese Utility Model Application No. 63-150922 are large in size, so that their applications are considerably limited.
特開昭６３−１６８６２２号公報に記載のものでは、偏
光面の回転にＴＮ液晶を用いることにより比較的小型で
且つ極めて簡単な構造で前記の機能を実現している。但
し、ここでは偏光ビームスプリッタ−によって分けられ
た２つの光が空間的に分離した状態で出射ビームを構成
するために、液晶層を通過する際に受ける若干の減衰等
により出射ビームに明るさのむらを生ずるという難点が
ある。The device described in Japanese Unexamined Patent Publication No. 63-168622 uses a TN liquid crystal to rotate the plane of polarization, thereby realizing the above function with a relatively small and extremely simple structure. However, in this case, since the two lights separated by the polarizing beam splitter constitute the output beam in a spatially separated state, the output beam may have uneven brightness due to slight attenuation received when passing through the liquid crystal layer. The problem is that it causes
［発明が解決しようとする課題］
本発明の目的は、ランダム偏光の光源を用いて効率よく
直線偏光を作る際に、出射ビームに明るさのむらが生じ
にくい偏光光源装置を提供することある。[Problems to be Solved by the Invention] An object of the present invention is to provide a polarized light source device that is less likely to cause brightness unevenness in an emitted beam when linearly polarized light is efficiently produced using a randomly polarized light source.
［課題を解決するための手段］
本発明の請求項１に記載の偏光光源装置は、光源と、該
光源から発せられる光を２方向に分岐するプリズムと、
該分岐手段からの２つの分岐光のそれぞれについてｐ偏
光成分光及びＳ偏光成分光の一方を反射させ且つ他方を
透過させる偏光ビームスプリッタ−と、該偏光ビームス
プリッタ−からの反射光及び透過光のうちの一方を偏光
面の９０°回転を伴って透過させる坏波長板と、上記偏
光ビームスプリッタ−によって分けられて得られた４つ
の光を通過させ合成させるため片面にプリズム列が形成
されている透明板と、該透明板の上記プリズム列形成面
と反対側の面へと上記４つの光を上記％波長板を透過し
た光と透過しない光とが重なる様に導く光反射手段とを
有することを特徴とする、偏光光源装置、
である。[Means for Solving the Problems] A polarized light source device according to claim 1 of the present invention includes a light source, a prism that branches light emitted from the light source into two directions,
a polarizing beam splitter that reflects one of the p-polarized component light and the s-polarized component light and transmits the other of the two branched lights from the splitting means; A prism array is formed on one side to pass and combine the four lights obtained by dividing them by the polarizing beam splitter and the polarizing wave plate that transmits one of them with a 90° rotation of the polarization plane. comprising a transparent plate and a light reflecting means for guiding the four lights to a surface of the transparent plate opposite to the prism row forming surface so that the light that has passed through the % wavelength plate and the light that has not passed overlap. A polarized light source device, characterized by:
また、請求項２に記載の偏光光源装置は、光源と、該光
源から発せられる光を２方向に分岐するプリズムと、該
分岐手段からの２つの分岐光のそれぞれについてｐ偏光
成分光及びＳ偏光成分光の一方を反射させ且つ他方を透
過させる偏光ビームスプリッタ−と、該偏光ビームスプ
リッタ−からの反射光及び透過光のうちの一方を偏光面
の９０°回転を伴って透過させるＴＮ液晶セルと、上記
偏光ビームスプリッタ−によって分けられて得られた４
つの光を通過させ合成させるため片面にプリズム列が形
成されている透明板と、該透明板の上記プリズム列形成
面と反対側の面へと上記４つの光を上記ＴＮ液晶セルを
透過した光と透過しない光とが重なる様に導く光反射手
段とを有することを特徴とする、偏光光源装置、である
。The polarized light source device according to claim 2 further includes a light source, a prism that branches light emitted from the light source into two directions, and p-polarized component light and S-polarized light for each of the two branched lights from the splitting means. A polarizing beam splitter that reflects one of the component lights and transmits the other, and a TN liquid crystal cell that transmits one of the reflected light and the transmitted light from the polarizing beam splitter with a 90° rotation of the plane of polarization. , obtained by dividing by the above polarizing beam splitter.
A transparent plate having a prism array formed on one side for passing and combining the four lights, and the light transmitted through the TN liquid crystal cell to transmit the four lights to the surface of the transparent plate opposite to the surface on which the prism array is formed. This is a polarized light source device characterized by having a light reflecting means for guiding light and non-transmitted light so that they overlap.
［作用］
本発明の偏光光源装置は、光源からの光を２方向に分岐
し、次に各分岐光について偏光ビームスプリッタ−で２
つの直線偏光成分に分け、その−方の偏光面を９０”回
転させ、かくして得られた４つの光のうち偏光面回転を
受けた光と受けない光とを合流させるものであり、偏光
面回転のための手段として％波長板あるいはＴＮ液晶セ
ルを用い、上記偏光面回転を受けた光と受けない光（こ
れらの光の偏光面は揃えられている）とを反射面等の光
反射手段によって重なりあう様に導き、ここに光出射側
の面にプリズム列が形成されている透明板を配置し、該
透明板によって平行な直線偏光出射光を得るものである
。[Operation] The polarized light source device of the present invention splits light from a light source into two directions, and then splits each branched light into two directions using a polarized beam splitter.
It separates the light into two linearly polarized components, rotates the negative plane of polarization by 90'', and combines the light that has undergone polarization plane rotation and the light that has not undergone polarization plane rotation among the four light beams obtained in this way. As a means for this purpose, a wavelength plate or a TN liquid crystal cell is used, and the light that has undergone the rotation of the polarization plane and the light that has not been rotated (the polarization planes of these lights are aligned) are reflected by a light reflecting means such as a reflective surface. A transparent plate having an array of prisms formed on the surface on the light exit side is arranged here so that parallel linearly polarized light is emitted from the transparent plate.
［実施例］
以下、実施例を用いて本発明を説明する。尚、以下の実
施例における坏波長板をＴＮ液晶セルに置き換えたもの
が請求項２の実施例となる。[Example] The present invention will be described below using Examples. Incidentally, an embodiment according to claim 2 is obtained by replacing the wave plate in the following embodiments with a TN liquid crystal cell.
以下の実施例では、光源からのランダム偏光を２方向に
分岐する手段として透明板の片面に形成された微小プリ
ズム列を用いており、これにより装置の小型化を図って
いる。もちろん、１つのプリズムを用いて同様の機能を
果たすこともできる。In the following embodiments, a micro prism array formed on one side of a transparent plate is used as a means for splitting randomly polarized light from a light source into two directions, thereby reducing the size of the device. Of course, a single prism can also be used to perform the same function.
第１図及び第２図はいずれも請求項１の実施例の装置の
平面図であり、第３図は第１図の装置の斜視図である。1 and 2 are both plan views of the apparatus according to the embodiment of claim 1, and FIG. 3 is a perspective view of the apparatus of FIG. 1.
第１図の実施例において、光源５からの光は曲面鏡６で
平行光とされ、該平行光は片面にプリズム列の形成され
た透明板２で２方向に分岐せしめられる。各分岐光はそ
れぞれ別のプリズム型偏光ビームスプリッタ−４に入射
し、該入射光のうちｐ偏光成分（図中、実線で示されて
いる）は偏光ビームスプリッタ−４を透過し、坏波長板
３で偏光面を回転せしめられてＳ偏光成分となる。この
光線は、反射鏡７で反射せしめられ、更に透明板ｌに入
射し、該透明板に形成されたプリズムで屈折せしめられ
て出射光となる。一方、偏光ビームスプリッタ−４に入
射した光のうちＳ偏光成分（図中、破線で示されている
）は、該偏光ビームスプリッタ−で反射せしめられ、更
に反射鏡７で反射せしめられた後、透明板ｌに入射し、
該透明板に形成されたプリズムで屈折せしめられて出射
光となる。In the embodiment shown in FIG. 1, light from a light source 5 is converted into parallel light by a curved mirror 6, and the parallel light is split into two directions by a transparent plate 2 having an array of prisms formed on one side. Each branched light is incident on a separate prism-type polarizing beam splitter 4, and the p-polarized component (indicated by a solid line in the figure) of the incident light is transmitted through the polarizing beam splitter 4, 3, the plane of polarization is rotated and becomes an S-polarized component. This light beam is reflected by a reflecting mirror 7, further incident on a transparent plate l, and is refracted by a prism formed on the transparent plate to become an output light. On the other hand, the S-polarized component (indicated by a broken line in the figure) of the light incident on the polarizing beam splitter 4 is reflected by the polarizing beam splitter, further reflected by the reflecting mirror 7, and then incident on the transparent plate l,
The light is refracted by a prism formed on the transparent plate and becomes an emitted light.
以上により、光源５からの光の２つの偏光成分が、Ｓ偏
光となって出射される。As a result of the above, the two polarized light components of the light from the light source 5 are emitted as S-polarized light.
ここで、２枚の反射鏡７及び２つの偏光ビームスプリッ
タ−４の反射面はいずれも平行であり、これらは透明板
１と垂直に配置されている。従って、透明板２によって
分岐された光は、それぞれ２つの偏光ビームスプリッタ
−４に同じ角度（図では４５°）で入射する様に設定さ
れている。Here, the reflecting surfaces of the two reflecting mirrors 7 and the two polarizing beam splitters 4 are parallel, and are arranged perpendicularly to the transparent plate 1. Therefore, the lights split by the transparent plate 2 are set to be incident on the two polarizing beam splitters 4 at the same angle (45° in the figure).
第２図の実施例は、局波長板３が偏光ビームスプリッタ
−４で反射せしめられるＳ偏光成分の光路中に置かれて
いる点を除き、上記第１図の実施例と同様である。尚、
この場合は、出射光はｐ偏光となる。The embodiment of FIG. 2 is similar to the embodiment of FIG. 1 above, except that the local wavelength plate 3 is placed in the optical path of the S-polarized light component reflected by the polarizing beam splitter 4. still,
In this case, the emitted light becomes p-polarized light.
以上の装置において、上記反射鏡７及び透明板１は、２
種類の光成分（Ｖ２波長板３で偏光面回転を受けた成分
と該偏光面回転を受けない成分）が透明板１上にて重な
る様に配置されている。そして、一方の偏光ビームスプ
リッタ−４からの偏光面回転を受けた光成分と他方の偏
光ビームスプリッタ−４からの偏光面回転を受けない光
成分とが透明板１上の一方の半分で重なり、また上記−
方の偏光ビームスプリッタ−４からの偏光面回転を受け
ない光成分と上記他方の偏光ビームスプリッタ−４から
の偏光面回転を受けた光成分とが透明板１上の他方の半
分で重なる様にされている。In the above device, the reflecting mirror 7 and the transparent plate 1 are
Different types of light components (components subjected to polarization plane rotation by the V2 wavelength plate 3 and components not subjected to the polarization plane rotation) are arranged so as to overlap on the transparent plate 1. Then, the light component that has undergone polarization plane rotation from one polarizing beam splitter 4 and the light component that has not undergone polarization plane rotation from the other polarizing beam splitter 4 overlap on one half of the transparent plate 1, Also above-
The light component from one polarizing beam splitter 4 that has not undergone polarization plane rotation and the light component that has undergone polarization plane rotation from the other polarization beam splitter 4 overlap on the other half of the transparent plate 1. has been done.
例えば、第４図の比較例に示す様に、小型化をはかるた
め透明板１の設置位置を変えた場合には、偏光ビームス
プリッタ−４を透過した光成分は透明板１の周辺部から
出射し、偏光ビームスプリッタ−４により反射せしめら
れた光成分は該偏光ビームスプリッタ−の中央部から出
射するが、これら２つの光成分は、
・偏光ビームスプリッタ−４のＳ偏光に対する反射率と
ｐ偏光に対する透過率とが厳密には等しくないこと、
・坏波長板３での反射や吸収によるロスがあること、
・坏波長板３に位相差角の波長依存性があること、
等によって、強度及びスペクトルが異なるため、出射光
にむらを生じ、好ましくない。For example, as shown in the comparative example in FIG. 4, when the installation position of the transparent plate 1 is changed in order to achieve miniaturization, the light component that has passed through the polarizing beam splitter 4 is emitted from the periphery of the transparent plate 1. The light component reflected by the polarizing beam splitter 4 is emitted from the center of the polarizing beam splitter, and these two light components are: - The reflectance of the polarizing beam splitter 4 for S-polarized light and the p-polarized light The transmittance is not strictly equal to Since the spectra are different, the emitted light becomes uneven, which is not preferable.
上記第１図及び第２図の場合には、これら２つの光成分
が出射面（透明板１）で−様に混ざりあうので、上記第
４図の場合の様な問題は起こらない。In the case of FIGS. 1 and 2 above, these two light components mix in a negative manner at the exit surface (transparent plate 1), so the problem as in the case of FIG. 4 does not occur.
本発明の透明板ｌに形成されるプリズムの形状は、第５
図から分かる通り、透明板１の法線と平行な出射光を得
るために、プリズム面と透明板の法線とのなす角θが、
以下の式（１）を満足する様に選べばよい。The shape of the prism formed on the transparent plate l of the present invention is
As can be seen from the figure, in order to obtain emitted light parallel to the normal line of the transparent plate 1, the angle θ between the prism surface and the normal line of the transparent plate is
It may be selected so as to satisfy the following equation (1).
尚、ここで、ｎｌは透明板１の屈折率、βは透明板１へ
光線が入射する際の入射角である。Note that here, nl is the refractive index of the transparent plate 1, and β is the incident angle at which the light ray is incident on the transparent plate 1.
また、第５図において、α≧θとなる様にｎ及びβを選
ぶことが好ましい。もしαくθであれば、入射光の一部
がプリズムのもう一方の傾斜面での反射により方向を変
え、平行な出射光とならないため、効率の低下をまねく
。Further, in FIG. 5, it is preferable to select n and β so that α≧θ. If α and θ, a part of the incident light changes its direction due to reflection on the other inclined surface of the prism and does not become parallel outgoing light, resulting in a decrease in efficiency.
一方、本発明の透明板２に形成されるプリズムの形状は
、第６図から分かる通り、プリズム面と透明板２の法線
とのなす角δが、以下の式（２）を満足する様に選べば
よい。On the other hand, as can be seen from FIG. 6, the shape of the prism formed on the transparent plate 2 of the present invention is such that the angle δ between the prism surface and the normal to the transparent plate 2 satisfies the following equation (2). All you have to do is choose.
尚、ここで、ｎ２は透明板２の屈折率である。Note that here, n2 is the refractive index of the transparent plate 2.
第６図において、γ〉δであれば、入射光の一部がプリ
ズムのもう一方の傾斜面での反射により方向を変え出射
角がβとならないため、効率の低下をまねく。従って、
γ≦δとなる様にｎ２及びδを選ぶのが好ましい。In FIG. 6, if γ>δ, part of the incident light changes direction due to reflection on the other inclined surface of the prism, and the output angle does not become β, resulting in a decrease in efficiency. Therefore,
It is preferable to select n2 and δ so that γ≦δ.
尚、２つの透明板１．２を同じ材質で作る場合には、ｎ
＋＝ｎｚであるので、上記式（１）。In addition, when the two transparent plates 1.2 are made of the same material, n
Since +=nz, the above formula (1).
（２）から、γ＝α、δ＝θであり、形成するプリズム
は相似形となる。更に、上記α≧θ、γ≦δの条件下で
は、γ＝α＝δ＝θとなり、上記式（１）をθについて
解けば、
θ＝ ｃｏｓ−’ （（１＋ ！Ｆ■７）／４ｒ＋＋）
・・・（３）となる。From (2), γ=α and δ=θ, and the prisms to be formed have similar shapes. Furthermore, under the conditions of α≧θ and γ≦δ, γ=α=δ=θ, and solving the above equation (1) for θ, θ= cos-' ((1+ !F■7)/4r++ )
...(3).
上記第１図及び第２図の実施例においては、β＝４５°
であるから、ｎ ＋ ” ｎ ２のときには、上記式（
３）からｎ＋ ＝ｎｚ ＝ １．５４となり、屈折率１
．５４の材料を用いればよいことが分かる。また、β＝
４５°のときに、透明板１と透明板２とを異なる材料で
作る場合にはｎ１≦１．５４、ｎ２≧１．５４となる様
に材料を選定すればよい。In the embodiment shown in FIGS. 1 and 2 above, β=45°
Therefore, when n + ” n 2, the above formula (
3), n+ = nz = 1.54, and the refractive index is 1.
．． It can be seen that 54 materials may be used. Also, β=
When the angle is 45°, when transparent plate 1 and transparent plate 2 are made of different materials, the materials may be selected so that n1≦1.54 and n2≧1.54.
本発明の偏光光源装置に用いられる偏光ビームスプリッ
タ−は、消光比、及び消光比の角度依存性、波長依存性
等の点からプリズム型偏光ビームスプリッタ−を用いる
のが好ましいが、単色光に対して用いる場合については
、有効な波長範囲が狭いミラー型偏光ビームスプリッタ
−を使用することも可能である。As the polarizing beam splitter used in the polarizing light source device of the present invention, it is preferable to use a prism-type polarizing beam splitter from the viewpoint of extinction ratio, angular dependence of extinction ratio, wavelength dependence, etc. However, for monochromatic light, For applications where the wavelength range is narrow, it is also possible to use a mirror-type polarizing beam splitter with a narrow effective wavelength range.
第７図はミラー型偏光ビームスプリッタ−８を用いた実
施例であるが、該偏光ビームスプリッタ−は入射角を任
意に選べるため、２つの反射鏡６を平行に配置したまま
でβを任意に選択すイ）ことができる。本実施例は、β
〉４５°の実施例である。FIG. 7 shows an example using a mirror type polarizing beam splitter 8. Since the incident angle of this polarizing beam splitter can be arbitrarily selected, β can be arbitrarily set while the two reflecting mirrors 6 are arranged in parallel. (Choose a) I can do it. In this example, β
>45°.
本発明の請求項１に記載の坏波長板としては、雲母、水
晶等の無機物の結晶を所定の厚さに成形したものや、ポ
リカーボネート、ポリエステル等の複屈折を示す高分子
フィルムを所定の倍率に延伸したもの等が用いられる。The crystalline wave plate according to claim 1 of the present invention may be formed by molding inorganic crystals such as mica or quartz to a predetermined thickness, or by forming a polymer film exhibiting birefringence such as polycarbonate or polyester at a predetermined magnification. A stretched material is used.
また、請求項２に記載のＴＮ液晶セルは、ラビング等に
よって一軸配向処理を行った一対の透明基板を、配向軸
が互いに直交する様に向かい合わせ、これらの間にネマ
ティック液晶を充填させたもので、液晶分子の分子軸は
これらの基板の間で９０’捩れたヘリカル構造を形成し
、入射偏光光の偏光面をこのヘリカル構造に沿って回転
させるものである。Further, the TN liquid crystal cell according to claim 2 is a cell in which a pair of transparent substrates subjected to uniaxial alignment treatment by rubbing or the like face each other so that their alignment axes are perpendicular to each other, and nematic liquid crystal is filled between them. The molecular axes of the liquid crystal molecules form a 90' twisted helical structure between these substrates, and the plane of polarization of incident polarized light is rotated along this helical structure.
このＴＮ液晶セルを用いたものは、偏光面を回転させる
性質が波長依存性を持たない点で、白色光源に使用する
のに好ましい。しかしながら、セルを通過する際の光の
損失を少なくする様注意しなければならず、また液晶の
温度特性に注意しなければならない等、坏波長板に比較
して取扱がやや難しい。A device using this TN liquid crystal cell is preferable for use as a white light source because the property of rotating the plane of polarization has no wavelength dependence. However, it is somewhat difficult to handle compared to a crystal wave plate, as care must be taken to reduce the loss of light when passing through the cell, and attention must be paid to the temperature characteristics of the liquid crystal.
一方、％波長板は、偏光面の回転効率に波長依存性があ
るものの、可視光全域にそこそこの効果（８０％以上）
を示し、白色光に適用することも十分可能である。On the other hand, the % wave plate has a wavelength dependence in the rotation efficiency of the polarization plane, but has a moderate effect (over 80%) over the entire visible light range.
It is also possible to apply it to white light.
上記第１図、第２図及び第７図の実施例で用いられる反
射鏡７は、基板に金属または誘電体多層膜を蒸着したも
の等が用いられるが、これらの他にも第８図に断面図を
示す様な微小な直角プリズムを片面に形成した屈折率ｆ
１以上の透明板を用いることもできる。The reflecting mirror 7 used in the embodiments shown in FIGS. 1, 2, and 7 above is made of a substrate with a metal or dielectric multilayer film deposited on it. Refractive index f with a minute right-angle prism formed on one side as shown in the cross-sectional view
One or more transparent plates can also be used.
本発明の説明図には、光源に曲面ミラーを使ったビーム
光源を用いたが、レンズを用いたビーム光源であっても
、全（同様であることはいうまでもない。In the explanatory drawings of the present invention, a beam light source using a curved mirror is used as a light source, but it goes without saying that the same applies to a beam light source using a lens.
［発明の効果］
以上説明した様に、本発明による偏光光源装置は、ラン
ダム偏光の光源から小型の簡単な装置を用いて、明るさ
むらを生ずることなしに直線偏光の光を効率よ（作るこ
とを可能にした。[Effects of the Invention] As explained above, the polarized light source device according to the present invention efficiently generates linearly polarized light from a randomly polarized light source using a small and simple device without causing uneven brightness. made it possible.
第１図、第２図及び第７図はいずれも本発明の偏光光源
装置の平面図である。
第３図は本発明の偏光光源装置の斜視図である。
第４図は比較例の偏光光源装置の平面図である。
第５図及び第６図はいずれもプリズムを形成した透明板
における光通過状態を示す図である。
第８図は反射鏡の一例を示す断面図である。
第３図
１．２・・・プリズムを形成した透明板、３・・・％波
長板、
４・・・プリズム型偏光ビームスプリッタ−５・・・光
源、 ６・・・曲面鏡、７・・・反射鏡、
８・・・ミラー型偏光ビームスプリッタ−第４図1, 2, and 7 are all plan views of the polarized light source device of the present invention. FIG. 3 is a perspective view of the polarized light source device of the present invention. FIG. 4 is a plan view of a polarized light source device of a comparative example. FIG. 5 and FIG. 6 are both diagrams showing the state of light passing through a transparent plate in which a prism is formed. FIG. 8 is a sectional view showing an example of a reflecting mirror. Figure 3 1.2...Transparent plate with prism formed, 3...% wavelength plate, 4...Prism type polarizing beam splitter-5...Light source, 6...Curved mirror, 7...・Reflector, 8...Mirror type polarizing beam splitter - Figure 4
Claims (2)
するプリズムと、該分岐手段からの２つの分岐光のそれ
ぞれについてｐ偏光成分光及びｓ偏光成分光の一方を反
射させ且つ他方を透過させる偏光ビームスプリッターと
、該偏光ビームスプリッターからの反射光及び透過光の
うちの一方を偏光面の９０°回転を伴って透過させるに
波長板と、上記偏光ビームスプリッターによって分けら
れて得られた４つの光を通過させ合成させるため片面に
プリズム列が形成されている透明板と、該透明板の上記
プリズム列形成面と反対側の面へと上記４つの光を上記
に波長板を透過した光と透過しない光とが重なる様に導
く光反射手段とを有することを特徴とする、偏光光源装
置。(1) A light source, a prism that splits light emitted from the light source into two directions, and a prism that reflects one of the p-polarized component light and the s-polarized component light and reflects the other of the two branched lights from the splitting means. A polarizing beam splitter that transmits the polarizing beam splitter, a wavelength plate that transmits one of the reflected light and the transmitted light from the polarizing beam splitter with a 90° rotation of the plane of polarization, and a polarizing beam splitter that is divided by the polarizing beam splitter. A transparent plate having a prism array formed on one side to pass and synthesize the four lights, and a wavelength plate that transmits the four lights to the surface of the transparent plate opposite to the surface on which the prism array is formed. A polarized light source device comprising a light reflecting means for guiding light and untransmitted light so that they overlap.
するプリズムと、該分岐手段からの２つの分岐光のそれ
ぞれについてｐ偏光成分光及びｓ偏光成分光の一方を反
射させ且つ他方を透過させる偏光ビームスプリッターと
、該偏光ビームスプリッターからの反射光及び透過光の
うちの一方を偏光面の９０°回転を伴って透過させるＴ
Ｎ液晶セルと、上記偏光ビームスプリッターによって分
けられて得られた４つの光を通過させ合成させるため片
面にプリズム列が形成されている透明板と、該透明板の
上記プリズム列形成面と反対側の面へと上記４つの光を
上記ＴＮ液晶セルを透過した光と透過しない光とが重な
る様に導く光反射手段とを有することを特徴とする、偏
光光源装置。(2) A light source, a prism that splits light emitted from the light source into two directions, and a prism that reflects one of the p-polarized component light and the s-polarized component light and reflects the other of the two branched lights from the splitting means. A polarizing beam splitter to transmit, and a T to transmit one of reflected light and transmitted light from the polarizing beam splitter with a 90° rotation of the plane of polarization.
N liquid crystal cell, a transparent plate having a prism row formed on one side for passing and combining the four lights obtained by being separated by the polarizing beam splitter, and a side of the transparent plate opposite to the surface on which the prism row is formed. A polarized light source device comprising: a light reflecting means for guiding the four lights to the plane of the TN liquid crystal cell so that the light that has passed through the TN liquid crystal cell and the light that has not passed through the cell overlap.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33664989A JPH03197920A (en) | 1989-12-27 | 1989-12-27 | Polarized light source |
| DE69025924T DE69025924T2 (en) | 1989-12-26 | 1990-12-26 | OPTICAL DEVICE FOR GENERATING POLARIZED LIGHT |
| PCT/JP1990/001699 WO1991010153A1 (en) | 1989-12-26 | 1990-12-26 | Optical apparatus for generating polarized light |
| EP91901553A EP0460241B1 (en) | 1989-12-26 | 1990-12-26 | Optical apparatus for generating polarized light |
| US08/017,968 US5359455A (en) | 1989-12-26 | 1993-02-12 | Polarization forming optical device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33664989A JPH03197920A (en) | 1989-12-27 | 1989-12-27 | Polarized light source |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03197920A true JPH03197920A (en) | 1991-08-29 |
Family
ID=18301351
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33664989A Pending JPH03197920A (en) | 1989-12-26 | 1989-12-27 | Polarized light source |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03197920A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USRE39243E1 (en) | 1996-12-18 | 2006-08-22 | Seiko Epson Corporation | Optical element, polarization illumination device, and projector |
-
1989
- 1989-12-27 JP JP33664989A patent/JPH03197920A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USRE39243E1 (en) | 1996-12-18 | 2006-08-22 | Seiko Epson Corporation | Optical element, polarization illumination device, and projector |
| USRE40251E1 (en) | 1996-12-18 | 2008-04-22 | Seiko Epson Corporation | Optical element, polarization illumination device, and projector |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP7411255B2 (en) | Light-guiding optics employing polarized internal reflectors | |
| US5808709A (en) | Illuminator with polarization separating anisotropic layer between light guide and reflector | |
| JP2747349B2 (en) | Lighting system for liquid crystal display system | |
| US5359455A (en) | Polarization forming optical device | |
| US5856855A (en) | Edge-lit illumination system containing cholesteric polarizer and diffuser behind waveguide | |
| US5453859A (en) | Polarization beam splitter and projection display apparatus | |
| KR950006508A (en) | Optical components having phase-forming, color- and polarization-selective reflections, including cholesterol liquid crystals, methods for their preparation and use thereof | |
| KR20040097367A (en) | Image display unit | |
| US6078363A (en) | Image display apparatus | |
| US6142633A (en) | Polarized light illuminator and projection type image display apparatus | |
| JPH03156421A (en) | Polarized light source device | |
| US5506642A (en) | Projector with plastic mirror | |
| US5900973A (en) | Optical polarization device and projection system of liquid crystal valve type utilizing such a device | |
| US6094240A (en) | Liquid crystal display polarizing beam splitter with specific incidence angle | |
| JPH03197920A (en) | Polarized light source | |
| JPH03196015A (en) | Polarized light source device | |
| US20230288706A1 (en) | Optical elements for reducing visual artifacts in diffractive waveguide displays and systems incorporating the same | |
| JP6995169B2 (en) | 3D image projection device | |
| JPH03157621A (en) | Polarization light source | |
| RU2321031C1 (en) | Reflecting prism for bringing plane of polarization in rotation | |
| US7180666B2 (en) | Polarized light illumination device | |
| JPH04139416A (en) | Polarized light generating optical device | |
| JPH0458215A (en) | Polarized light generating optical device | |
| JPH0458214A (en) | Polarized light generating optical device | |
| US20240036429A1 (en) | Electrically controlled optical screen |