JP2007078944A

JP2007078944A - Laser projection apparatus

Info

Publication number: JP2007078944A
Application number: JP2005264946A
Authority: JP
Inventors: Kazuhisa Yamamoto; 和久山本; Kiminori Mizuuchi; 公典水内; Toshifumi Yokoyama; 敏史横山; Hiroyuki Furuya; 博之古屋; Shinichi Kadowaki; 愼一門脇
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 2005-09-13
Filing date: 2005-09-13
Publication date: 2007-03-29

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser projection apparatus capable of reflecting light beams in the direction of an observer, preventing images from beeing seen from surroundings, and concentrating light in the direction of the observer, thereby enabling the observer to see bright images. <P>SOLUTION: The laser projection apparatus has short-wavelength laser beam sources that generate at least three color laser beams, namely red, blue, and green laser beams. The apparatus also has a screen that reflects red, blue, and green laser beams emitted from the short-wavelength laser beam sources. The light beams are reflected so as to be limited to corresponding specific ranges of angle by an angle selecting element disposed on the screen. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、コヒーレント光を利用する光情報分野に使用するレーザ投射装置に関するものである。 The present invention relates to a laser projection apparatus used in the field of optical information using coherent light.

従来技術としてのレーザ投射装置（特開平０８−８３８７５７号公報）について説明する。 A laser projection apparatus (Japanese Patent Laid-Open No. 08-83757) as a conventional technique will be described.

レーザ投射装置は、図１１に示すように、赤、青、緑の３色のレーザ光を発生する短波長レーザ光源としてレーザ１、２、３を有し、かつ前記短波長レーザ光源からの赤、青、緑の３色のレーザ光（それぞれＰ１、Ｐ２、Ｐ３）が液晶セル７を介してスクリーン１０に照射される。赤色レーザ１の赤は半導体レーザ、青色レーザ２および緑色レーザ３は半導体レーザの波長変換を用いている。スクリーン１０は通常の水銀ランプを用いたプロジェクターで使用されるゲイン１のスクリーン（サイズ９０インチ）である。詳しく説明すると赤色レーザ１は連続発光動作しておりここから出たレーザ光Ｐ１はミラー５で反射され方向を変える。レンズ系６ａで液晶セル７に投射され、ここでセルごとに映像信号を載せるための変調をうける。レンズ系６ｂで拡大され、スクリーン１０上に投影される。同様に青色レーザ２および緑色レーザ３も映像信号が載せられスクリーン１０上に投影される。人はスクリーン手前（レーザ側）から、スクリーン１０の反射、散乱光を観測する。全白を出したときスクリーンでは２００ルクス程度の明るさとなっていた。
特開平０８−８３８７５７号公報 As shown in FIG. 11, the laser projection apparatus includes lasers 1, 2, and 3 as short wavelength laser light sources that generate laser light of three colors of red, blue, and green, and red light from the short wavelength laser light source. , Blue, and green laser beams (P1, P2, and P3, respectively) are applied to the screen 10 through the liquid crystal cell 7. The red laser 1 uses a semiconductor laser, and the blue laser 2 and the green laser 3 use wavelength conversion of the semiconductor laser. The screen 10 is a gain 1 screen (size 90 inches) used in a projector using a normal mercury lamp. More specifically, the red laser 1 is continuously emitting light, and the laser beam P1 emitted therefrom is reflected by the mirror 5 and changes its direction. The light is projected onto the liquid crystal cell 7 by the lens system 6a, and is subjected to modulation for placing a video signal for each cell. The image is magnified by the lens system 6 b and projected onto the screen 10. Similarly, the blue laser 2 and the green laser 3 are also projected on the screen 10 with video signals. A person observes the reflected and scattered light from the screen 10 from the front of the screen (laser side). When all white was put out, the screen was about 200 lux bright.
Japanese Patent Laid-Open No. 08-83757

スクリーン１０での散乱は均一であり広い範囲で画像が見えていた。ビーズ等を付加しゲイン改善のスクリーンは存在するが周囲での光量が半分になる程度であり、やはり周囲から充分見える。特に携帯型の場合は使用する個人のみで映像を見たい場合が多く問題となる。従来でもビーズにより反射を制限するスクリーンもあったが、中央以外の周囲でも１／３程度の光量があった。 Scattering on the screen 10 was uniform, and an image was visible in a wide range. There are screens for gain improvement by adding beads, but the amount of light in the surrounding area is halved, and it is still visible from the surroundings. In particular, in the case of a portable type, there are many cases where it is often desired to view the video only by the individual who uses it. In the past, there were screens that limited reflection by beads, but there was about 1/3 of the amount of light even around the center.

また、スクリーン１０は暗い部屋では良いが、室内灯が点灯している部屋では、スクリーン１０に室内灯が反射し、黒浮きがする（本来黒いところが白っぽく見える）という問題を発する。例えば照明が点灯状態でスクリーン上で２０ルクスとした場合、照明が消灯した場合ではコントラストが１０００：１であったものが、照明によりコントラストが１０：１まで低下してしまっていた。 The screen 10 may be a dark room, but in a room where the room light is lit, the room light is reflected on the screen 10 and floats black (originally black areas look whitish). For example, when the illumination is turned on and 20 lux is set on the screen, the contrast is 1000: 1 when the illumination is turned off, but the contrast is reduced to 10: 1 by the illumination.

本発明は、少なくとも赤、青、緑の３色のレーザ光を発生する短波長レーザ光源を有し、かつ前記短波長レーザ光源からの赤、青、緑の３色のレーザ光に対してレーザ光を反射するスクリーンを有し、前記反射光が前記スクリーンに設けられた角度選択素子により特定の角度範囲に制限され反射されるレーザ投射装置となる。 The present invention has a short-wavelength laser light source that generates laser beams of at least three colors of red, blue, and green, and lasers the laser light of three colors of red, blue, and green from the short-wavelength laser light source. The laser projection apparatus includes a screen that reflects light, and the reflected light is limited to a specific angle range and reflected by an angle selection element provided on the screen.

また、本発明は、少なくとも赤、青、緑の３色のレーザ光を発生する短波長レーザ光源を有し、かつ前記短波長レーザ光源からの赤、青、緑の３色のレーザ光がスクリーンに設けられた空孔を透過するレーザ投射装置となる。 The present invention also includes a short wavelength laser light source that generates laser light of at least three colors of red, blue, and green, and the red, blue, and green laser light from the short wavelength laser light source is a screen. It becomes a laser projection apparatus which permeate | transmits the hole provided in this.

以上説明したように本発明のレーザ投射装置は赤、青、緑の３色のレーザ光を出力し、レーザ光に対してのみ選択角度範囲に反射するスクリーンまたは光学構成を用いている。これによれば、映像情報が載せられたレーザ光は観測者の方向に反射され、一方周囲から映像を見えにくくすることができる。さらに、光を観測者の方向に集中でき、明るい画像を見ることが可能でありその工業的価値は極めて大きい。 As described above, the laser projection apparatus of the present invention uses a screen or an optical configuration that outputs laser light of three colors of red, blue, and green and reflects the laser light only in a selected angle range. According to this, the laser beam on which the video information is placed is reflected in the direction of the observer, and the video can be made difficult to see from the surroundings. Furthermore, the light can be concentrated in the direction of the observer and a bright image can be seen, and its industrial value is extremely large.

また本発明のレーザ装置によれば照明光は吸収し、レーザ光は空孔のみ部分的に透過するスクリーンを用いることで背面投写型ＴＶのコントラストを大幅に向上できる。レーザ光は観測者の方向に角度依存性を持って透過され、一方周囲から映像を見えにくくすることができる。 Further, according to the laser apparatus of the present invention, the contrast of the rear projection TV can be greatly improved by using a screen that absorbs illumination light and partially transmits laser light only through holes. The laser beam is transmitted with an angle dependency in the direction of the observer, while the image can be made difficult to see from the surroundings.

以下、実施の形態を用いて本発明をさらに具体的に説明する。 Hereinafter, the present invention will be described more specifically using embodiments.

（実施の形態１）
本発明のレーザ投射装置の実施の形態１の構成図を図１に示す。 (Embodiment 1)
FIG. 1 shows a configuration diagram of Embodiment 1 of the laser projection apparatus of the present invention.

本実施の形態では前面からレーザ光を投射し、観測者としての人間がレーザの照射される側と同じ側（前面）から観測する構成について説明する。図１はレーザ反射の範囲制限についての説明図である。レーザ光４０はスクリーンに入射角θ１で入射し反射光４１はパワー中心として反射角θ２で反射する。この際散乱で反射の散乱角７２は角度幅Δθ（１０分の１の光量となるところ）の領域が観測者の観測できる領域となる。 In this embodiment, a configuration in which laser light is projected from the front surface and a human being as an observer observes from the same side (front surface) as the laser irradiation side will be described. FIG. 1 is an explanatory diagram for limiting the range of laser reflection. The laser light 40 is incident on the screen at an incident angle θ1, and the reflected light 41 is reflected at the reflection angle θ2 as the center of power. At this time, the scattering angle 72 of the reflection due to scattering is a region where the observer can observe the region having the angle width Δθ (where the light amount is 1/10).

図２には本発明の実施の形態の赤、青、緑色のレーザ光を反射するスクリーンを有するレーザ投射装置の全体構成を示す。スクリーンには角度選択素子を有している。また赤、青、緑の３色の短波長レーザ光源としてレーザを有し（それぞれ図中の１，２，３）、かつ前記レーザから発生する赤、青、緑の３色のレーザ光（それぞれＰ１、Ｐ２、Ｐ３）に対してのみ反射するスクリーン１０を用いている。図２で赤色レーザ１は連続発光動作しておりここから出たレーザ光Ｐ１はミラー５で反射され方向を変える。レンズ系６ａで液晶セル７に投射され、ここでセルごとに映像信号を載せるための変調をうける。レンズ系６ｂで拡大され、スクリーン１０上に投影される。同様に青色レーザ２および緑色レーザ３も映像信号が載せられスクリーン１０上に投影される。観測者である人間はスクリーン手前（レーザ側）から、スクリーン１０の反射、散乱光を観測する。角度選択素子として反射角度を制御する配置を採った。 FIG. 2 shows the overall configuration of a laser projection apparatus having a screen that reflects red, blue, and green laser light according to an embodiment of the present invention. The screen has an angle selection element. In addition, lasers are used as short-wavelength laser light sources of three colors of red, blue, and green (1, 2, and 3 in the figure, respectively), and laser beams of three colors of red, blue, and green (respectively, respectively) A screen 10 that reflects only to P1, P2, P3) is used. In FIG. 2, the red laser 1 is continuously emitting light, and the laser beam P1 emitted therefrom is reflected by the mirror 5 and changes its direction. The light is projected onto the liquid crystal cell 7 by the lens system 6a, and is subjected to modulation for placing a video signal for each cell. The image is magnified by the lens system 6 b and projected onto the screen 10. Similarly, the blue laser 2 and the green laser 3 are also projected on the screen 10 with video signals. The human being who observes observes the reflected and scattered light from the screen 10 from the front of the screen (laser side). An arrangement for controlling the reflection angle was adopted as the angle selection element.

図３で本発明のレーザ投射装置の実施の形態１の原理を詳しく説明する。反射体の前には散乱体を有しておりレーザ光はある程度各方向に散乱される。そのためスクリーン１０は拡散体１２と反射体１１により構成されている。レーザ投射部５０は３色のレーザ、レンズ系、液晶セル等の投射部を含んだものである。レーザ投射部５０からのレーザ光４０は拡散体１２で方向が各位置で少し変化し、反射体１１で反射され再び拡散体１２を通って反射光４１として、見ている人の目に入る。一方、室内照明３０からの照明光４２は拡散体１２および反射体１１を抜けていく。図４はスクリーン上下方向の反射散乱光の分布である。また図５はスクリーン横方向の反射散乱光の分布である。全角度は上下方向約２０度、横である左右方向約３０度にわたって存在し、その周囲では画像はほとんど見ることができない。図５に反射体１１の波長に対する反射特性を示す。照射されるレーザ光の青４６５ｎｍ、緑５３２ｎｍ、赤６３５ｎｍに対して波長ピークを持ち、反射体として８０％反射する誘電体多層膜で出来ている。この実施の形態で散乱体１２は浅い凹凸を持つすりガラスでできている。これにより外光の反射は極めて抑えられ黒浮きをかなり防止できる。コントラストは約１０倍改善された。誘電体多層膜と散乱体の組み合わせで角度選択素子となり、これにより角度依存性を持たせることができ、この構成は安価で大量に生産可能である。 The principle of Embodiment 1 of the laser projection apparatus of the present invention will be described in detail with reference to FIG. A scatterer is provided in front of the reflector, and the laser light is scattered to some extent in each direction. Therefore, the screen 10 includes a diffuser 12 and a reflector 11. The laser projection unit 50 includes projection units such as three color lasers, a lens system, and a liquid crystal cell. The laser light 40 from the laser projection unit 50 is slightly changed in direction at each position by the diffuser 12, reflected by the reflector 11, and again passes through the diffuser 12 as reflected light 41 and enters the eyes of the viewer. On the other hand, the illumination light 42 from the room illumination 30 passes through the diffuser 12 and the reflector 11. FIG. 4 shows the distribution of reflected and scattered light in the vertical direction of the screen. FIG. 5 shows the distribution of reflected and scattered light in the horizontal direction of the screen. The entire angle exists over about 20 degrees in the vertical direction and about 30 degrees in the horizontal direction, which is the horizontal direction, and almost no image can be seen around it. FIG. 5 shows the reflection characteristics with respect to the wavelength of the reflector 11. It is made of a dielectric multilayer film having a wavelength peak with respect to blue 465 nm, green 532 nm, and red 635 nm of the irradiated laser light and reflecting 80% as a reflector. In this embodiment, the scatterer 12 is made of ground glass having shallow irregularities. As a result, reflection of external light is extremely suppressed, and black float can be considerably prevented. The contrast was improved about 10 times. The combination of the dielectric multilayer film and the scatterer provides an angle selection element, which can provide angle dependency, and this configuration is inexpensive and can be produced in large quantities.

このように周囲から観測できない上に、照明光がある部屋でも黒浮きが少なく、コントラストの良い画面が得られるのはレーザ光の発振波長幅が極めて狭いことにより可能となる。図４のように観測者の上下方向で観測者の方向に反射ピークを一致させると、明るさがピークを保て良い。また左右方向は観測者を中心にできるので図５に示すように対称にするのが良い。この構成が周囲からの覗き見に対して十分効果がある。 In this way, it is not possible to observe from the surroundings, and even in a room with illumination light, it is possible to obtain a high contrast screen with little black floating due to the extremely narrow oscillation wavelength width of the laser light. As shown in FIG. 4, when the reflection peak is made to coincide with the observer's direction in the vertical direction of the observer, the brightness may be kept at the peak. Further, since the left and right direction can be centered on the observer, it is preferable to make it symmetrical as shown in FIG. This configuration is sufficiently effective for peeping from the surroundings.

このような構成により映像情報が載せられたレーザ光以外の明かり（例えば室内照明、太陽などの外光）がスクリーンで反射され、映像を見えにくくすることを防止できる。 With such a configuration, it is possible to prevent the light other than the laser light on which the video information is placed (for example, room light, outside light such as the sun) from being reflected by the screen and making the image difficult to see.

この実施の形態では赤色レーザ１として６４０ｎｍの赤色半導体レーザ、また青色レーザ２、緑色レーザ３には半導体レーザの光波長変換による短波長レーザ光源を用いた。半導体レーザは消費電力も小さく、装置も小型化できるので良い。光波長変換素子としてＭｇＯドープのＬｉＮｂＯ_３基板を用いたものである。青色用および緑色用は同構成であるので、簡単に緑色について説明する。ここで用いた半導体レーザは波長８１０ｎｍ、出力２Ｗのものである。これにより固体レーザの共振器をポンプし光変換素子により２００ｍＷの緑色光（波長５３２ｎｍ）が取り出された。緑色は波長変換による構成が高効率で光を取り出せ実用的である。 In this embodiment, a red semiconductor laser having a wavelength of 640 nm is used as the red laser 1, and a short wavelength laser light source is used as the blue laser 2 and the green laser 3 by converting the wavelength of the semiconductor laser. A semiconductor laser is good because it consumes less power and the size of the device can be reduced. An MgO-doped LiNbO ₃ substrate is used as the optical wavelength conversion element. Since blue and green have the same configuration, green will be described briefly. The semiconductor laser used here has a wavelength of 810 nm and an output of 2 W. Thereby, the resonator of the solid laser was pumped, and 200 mW of green light (wavelength 532 nm) was extracted by the light conversion element. Green is practical because the wavelength conversion configuration can extract light with high efficiency.

青色、緑色は２００ｍＷ、赤色は半導体レーザで４００ｍＷとなり、装置が構成される。横モードおよびパワーは安定で色再現性が良く、かつコントラストが良い映像が得られた。レーザ光源は高効率であるため装置全体の消費電力は８Ｗであり、バッテリ駆動が可能であった。バッテリ駆動は持ち運び可能であり、他者からは観測困難な本構成が効果的である。 Blue and green are 200 mW, and red is 400 mW with a semiconductor laser, so that the apparatus is configured. The horizontal mode and power were stable, the color reproducibility was good, and the contrast was good. Since the laser light source is highly efficient, the power consumption of the entire apparatus is 8 W, and battery driving is possible. The battery drive is portable, and this configuration, which is difficult to observe from others, is effective.

（実施の形態２）
本発明の実施の形態２について説明する。基本的には実施の形態１と同様の構成である。レーザとしては３原色光を発生する３種類の短波長レーザ光源はともに半導体レーザを用いた。６４０ｎｍの赤色レーザ、５２０ｎｍの緑色レーザ、４５０ｎｍの青色レーザである。それぞれ出力は４０ｍＷ、３０ｍＷ、２５ｍＷであった。 (Embodiment 2)
A second embodiment of the present invention will be described. The configuration is basically the same as in the first embodiment. As the laser, semiconductor lasers were used for all of the three types of short wavelength laser light sources generating three primary color lights. A 640 nm red laser, a 520 nm green laser, and a 450 nm blue laser. The outputs were 40 mW, 30 mW, and 25 mW, respectively.

この実施の形態では反射体としてホログラム記録の有機膜を用いた。干渉露光により簡単に反射体を形成できるという特長がある。ここでは、散乱体として微小平面レンズ群を用いた。開口数０．１を持ち直径０．５ｍｍのものを平面に並べると、ロスが少なく有効に機能した。反射波長幅は５ｎｍに設定できたため通常の照明がある部屋においてもコントラストは２０まで改善できた。 In this embodiment, an organic film for hologram recording is used as the reflector. There is a feature that a reflector can be easily formed by interference exposure. Here, a microplanar lens group was used as the scatterer. Arranging ones with a numerical aperture of 0.1 and a diameter of 0.5 mm on a plane functioned effectively with little loss. Since the reflection wavelength width could be set to 5 nm, the contrast could be improved to 20 even in a room with normal illumination.

本実施の形態の装置全体の消費電力は３Ｗであり、容易にバッテリ駆動できた。バッテリ駆動は持ち運び可能であり、他者からは観測が困難な本構成が特に有効である。 The power consumption of the entire apparatus according to the present embodiment is 3 W, and can be easily driven by a battery. This configuration is particularly effective because it can be carried by battery and is difficult to observe from others.

（実施の形態３）
本発明の実施の形態３について説明する。基本的には実施の形態１と同様の構成である。レーザとしては３原色光を発生する３種類の短波長レーザ光源はともに半導体レーザを用いた。この実施の形態では反射体として通常の反射スクリーンとレンズアレイの組み合わせを用いた。レンズアレイは角度選択素子として機能している。下方からのレーザ光は上方に反射するためレンズアレイと反射ミラーを用いているが他の入射方向からは反射しにくいように吸収膜が反射面に形成されている。つまり反射すべき方向にしかミラーがなくそれ以外の方向から入る光は吸収される構成となる。レーザの入射光を異なる方向へと向けるように配置されている結果である。角度２０度以内で観測できた。 (Embodiment 3)
Embodiment 3 of the present invention will be described. The configuration is basically the same as in the first embodiment. As the laser, semiconductor lasers were used for all of the three types of short wavelength laser light sources generating three primary color lights. In this embodiment, a combination of a normal reflection screen and a lens array is used as the reflector. The lens array functions as an angle selection element. Since the laser beam from below is reflected upward, a lens array and a reflection mirror are used. However, an absorption film is formed on the reflection surface so as not to be reflected from other incident directions. In other words, there is a mirror only in the direction to be reflected, and light entering from other directions is absorbed. This is a result of arranging the incident light of the laser to be directed in different directions. It was observed within an angle of 20 degrees.

このように周囲から観測できない上に、照明光がある部屋でも黒浮きが少なく、コントラストの良い画面が得られた。観測者の上下方向で観測者の方向に反射ピークを一致させると、明るさがピークを保て良い。この構成が周囲からの覗き見に対して十分効果がある。 In this way, it was not possible to observe from the surroundings, and even in a room with illumination light, there was little black floating and a screen with good contrast was obtained. If the reflection peak is matched with the observer's direction in the vertical direction of the observer, the brightness may be kept at the peak. This configuration is sufficiently effective for peeping from the surroundings.

（実施の形態４）
次に本発明のレーザ投射装置による他の実施の形態を説明する。 (Embodiment 4)
Next, another embodiment of the laser projection apparatus of the present invention will be described.

本発明のレーザ投射装置の実施の形態４の構造図を図７に示す。本実施の形態では背面からレーザ光を投射し、人間が前面から映像を見る構成（背面投射型）について説明する。図７は、本実施の形態のレーザ投射装置である。赤、青、緑の３色のレーザ光を発生するレーザを有している。部分空孔の前には散乱体を有しておりレーザ光はある程度幅を持って散乱される。このような構成により周囲からは観察できにくくできる。図７で赤色レーザ１は連続動作しておりここから出たレーザ光Ｐ１は変調器４で映像信号が載せられポリゴンミラーを用いた水平偏向装置１５およびガルバノミラーを用いた垂直偏向装置１４でスクリーン１０上をスキャンされる。同様に青色レーザ２からのレーザ光Ｐ２および緑色レーザ３からのレーザ光Ｐ３も映像信号が載せられスクリーン１０上に投影される。人はレーザ光源側とは反対方向から、スクリーン１０の透過、散乱光を観測する。図８はスクリーンの背面から見たものである。部分的に空孔８０が設けてあり、それ以外は光が通過しないブラックマスク８１となっている。つまり空孔の周囲はレーザ光が不透過となっている。また空孔は画素と１対１対応、つまり一致している。レーザ光は変調されながらスクリーン上をスキャンされており、空孔８０より出力されていく。図９はレーザ光源の時間的応答であるが、変調同期信号が入った所のみレーザ光源は発光、これが空孔８０と同期しておりレーザ光が空孔８０を通り抜けるようになっている。この際、空孔８０の中心に達した時はレーザ光出力は最大となるように変調されると効率が良い。レーザ光源が発光している際の強度はアナログ諧調またはディジタル諧調のどちらか、または両方の組み合わせでもかまわない。 A structural diagram of Embodiment 4 of the laser projection apparatus of the present invention is shown in FIG. In the present embodiment, a configuration (rear projection type) in which laser light is projected from the back and a human views an image from the front will be described. FIG. 7 shows a laser projection apparatus according to this embodiment. A laser that generates laser beams of three colors of red, blue, and green is included. A scatterer is provided in front of the partial holes, and the laser light is scattered with a certain width. Such a configuration makes it difficult to observe from the surroundings. In FIG. 7, the red laser 1 is continuously operated, and a laser beam P1 emitted from the red laser 1 is loaded with a video signal by a modulator 4 and screened by a horizontal deflection device 15 using a polygon mirror and a vertical deflection device 14 using a galvano mirror. 10 is scanned. Similarly, a laser beam P2 from the blue laser 2 and a laser beam P3 from the green laser 3 are also projected onto the screen 10 with video signals placed thereon. A human observes the transmitted and scattered light from the screen 10 from the opposite direction to the laser light source side. FIG. 8 is a view from the back of the screen. The holes 80 are partially provided, and the other portions are black masks 81 through which light does not pass. That is, the laser beam is not transmitted around the hole. The holes correspond to the pixels in a one-to-one correspondence, that is, match. The laser beam is scanned on the screen while being modulated, and is output from the holes 80. FIG. 9 shows the time response of the laser light source. The laser light source emits light only when a modulation synchronization signal is input, and this is synchronized with the hole 80 so that the laser light passes through the hole 80. At this time, when the center of the hole 80 is reached, it is efficient if the laser light output is modulated so as to be maximized. The intensity when the laser light source emits light may be either analog gradation or digital gradation, or a combination of both.

なお本実施の形態では変調器を用いて変調を行ったが、直接半導体レーザを変調することも可能である。この際、部品点数が低減でき小型化も図れる。また、緑色は波長変換による構成が高効率で光を取り出せ実用的である。その際ポンプとなる基本波の直接変調が部品点数も増えず良い。 In this embodiment, modulation is performed using a modulator. However, it is also possible to directly modulate a semiconductor laser. At this time, the number of parts can be reduced and the size can be reduced. Also, green is practical because the wavelength conversion configuration can extract light with high efficiency. In this case, direct modulation of the fundamental wave serving as a pump is good without increasing the number of parts.

（実施の形態５）
次に本発明のレーザ投射装置による他の実施の形態を説明する。 (Embodiment 5)
Next, another embodiment of the laser projection apparatus of the present invention will be described.

本発明の実施の形態５について説明する。基本的には実施の形態４と同様の構成である。レーザ光源としては３原色光を発生する３種類の短波長レーザ光源はともに半導体レーザを用いた。この実施の形態では空孔を有する透過スクリーンとレンズアレイの組み合わせを用いた。レンズアレイにより散乱範囲を制限する構成となっている。図１０にスクリーン１０近傍での断面図を示す。変調されたレーザ光４０はスクリーン１０上をスキャンされており空孔８０より出力されていく。変調同期信号が入った所のみレーザ光源は発光、これが空孔８０と同期しており、レーザ光４０が空孔８０を通り抜けるようになっている。空孔を出て拡散体８０で散乱された光はレンズ８２のアレイで散乱角度を制限され観測者に到達する。つまり観測者の方向にしかレーザ光は散乱されず、それ以外の方向から入る光は見えない構成となる。この例では角度３０度以内で観測できた。この角度が観測者も尤度があり、また覗き見を防止する際も効果的な角度である。ただし人間の視野をある程度固定すると１０〜２０度と狭くても良い。 Embodiment 5 of the present invention will be described. The configuration is basically the same as that of the fourth embodiment. As the laser light source, a semiconductor laser was used for each of the three types of short wavelength laser light sources generating three primary color lights. In this embodiment, a combination of a transmissive screen having holes and a lens array is used. The scattering range is limited by the lens array. FIG. 10 shows a cross-sectional view in the vicinity of the screen 10. The modulated laser beam 40 is scanned on the screen 10 and outputted from the hole 80. The laser light source emits light only where the modulation synchronization signal is input, and this is synchronized with the hole 80, so that the laser light 40 passes through the hole 80. The light that has exited the holes and scattered by the diffuser 80 reaches the observer with the scattering angle limited by the array of lenses 82. That is, the laser beam is scattered only in the direction of the observer, and the light entering from other directions cannot be seen. In this example, it was observed within an angle of 30 degrees. This angle is also an angle that is effective for observers and also for preventing peeping. However, if the human visual field is fixed to some extent, it may be as narrow as 10 to 20 degrees.

またレーザ光源は高効率であるため装置全体の消費電力は小さく、バッテリ駆動が可能であった。バッテリ駆動は持ち運び可能であり、他者からは観測困難な本構成が効果的である。 Further, since the laser light source is highly efficient, the power consumption of the entire apparatus is small, and battery driving is possible. The battery drive is portable, and this configuration, which is difficult to observe from others, is effective.

なお実施の形態では３色のレーザ光源を用いたが４色を用いる等、これに限ることはない。また紫外レーザ光源を用いて蛍光を出す装置にも適用可能である。 In the embodiment, laser light sources of three colors are used, but four colors are used, but the present invention is not limited to this. Moreover, it is applicable also to the apparatus which emits fluorescence using an ultraviolet laser light source.

本発明は、コヒーレント光を利用する光情報分野に使用するレーザをスクリーンに投射しその映像を観測するレーザ投射装置に関する。 The present invention relates to a laser projection apparatus that projects a laser used in an optical information field using coherent light onto a screen and observes an image thereof.

本発明のレーザ投射装置の実施の形態１を示す構成図The block diagram which shows Embodiment 1 of the laser projection apparatus of this invention 本発明の実施の形態１のレーザ投射装置の全体構成を示す図The figure which shows the whole structure of the laser projection apparatus of Embodiment 1 of this invention. 本発明の実施の形態１のレーザ投射装置の原理を示す断面図Sectional drawing which shows the principle of the laser projection apparatus of Embodiment 1 of this invention 本発明の実施の形態のスクリーン上下方向の反射光の分布を示す図The figure which shows distribution of the reflected light of the screen up-down direction of embodiment of this invention 本発明の実施の形態のスクリーン横方向の反射光の分布を示す図The figure which shows distribution of the reflected light of the screen horizontal direction of embodiment of this invention 波長に対する反射特性を示す図Diagram showing reflection characteristics with respect to wavelength 本発明のレーザ投射装置の実施の形態４を示す構成図The block diagram which shows Embodiment 4 of the laser projection apparatus of this invention 本発明のレーザ投射装置の実施の形態４のスクリーンの背面図The rear view of the screen of Embodiment 4 of the laser projection apparatus of this invention 本発明のレーザ投射装置の実施の形態４の変調同期信号を示す図The figure which shows the modulation | alteration synchronizing signal of Embodiment 4 of the laser projection apparatus of this invention 本発明のレーザ投射装置の実施の形態５のスクリーン付近の断面図Sectional drawing of the screen vicinity of Embodiment 5 of the laser projection apparatus of this invention 従来のレーザ投射装置の構造図Structure of a conventional laser projector

Explanation of symbols

１赤色レーザ
２青色レーザ
３緑色レーザ
４変調器
５ミラー
６ａ，６ｂレンズ系
７液晶セル
１０スクリーン
１１反射体
１２拡散体
１３吸収体
１４垂直偏向装置
１５水平偏向装置
３０室内照明
４０レーザ光
４１反射光
４２照明光
５０レーザ投射部
７０入射角
７１反射角
７２散乱角
８０空孔
８１ブラックマスク
Ｐ１レーザ光
Ｐ２レーザ光
Ｐ３レーザ光 DESCRIPTION OF SYMBOLS 1 Red laser 2 Blue laser 3 Green laser 4 Modulator 5 Mirror 6a, 6b Lens system 7 Liquid crystal cell 10 Screen 11 Reflector 12 Diffuser 13 Absorber 14 Vertical deflector 15 Horizontal deflector 30 Indoor illumination 40 Laser light 41 Reflected light 42 Illumination Light 50 Laser Projection 70 Incident Angle 71 Reflection Angle 72 Scattering Angle 80 Hole 81 Black Mask P1 Laser Light P2 Laser Light P3 Laser Light

Claims

It has a short wavelength laser light source that generates laser light of at least three colors of red, blue, and green, and reflects the laser light with respect to laser light of three colors of red, blue, and green from the short wavelength laser light source. A laser projection apparatus having a screen, wherein the reflected light is limited and reflected within a specific angle range by an angle selection element provided on the screen.

2. The laser projection apparatus according to claim 1, wherein the screen includes a reflector that reflects only the wavelength peaks of all the lasers.

The laser projection apparatus according to claim 2, wherein a dielectric multilayer film in which reflected light is limited to a specific angle range is used as the reflector.

The laser projection apparatus according to claim 2, wherein hologram recording in which reflected light is limited to a specific angle range is used as the reflector.

The laser projection device according to claim 2, wherein a lens array in which reflected light is limited to a specific angle range is used as a reflector in front of the reflector.

The laser projection device according to claim 1, wherein an angle range of an angle selection element provided on the screen with respect to each laser beam is 30 degrees or less.

The laser projection apparatus according to claim 6, wherein an angle selection element is arranged to direct the reflected light in a different direction with respect to the laser light incident on the screen.

The laser projection apparatus according to claim 7, wherein an angle selection element is disposed so that the direction of reflected light from the screen is directed toward the observer.

2. The laser projection apparatus according to claim 1, wherein a semiconductor laser is used as the short wavelength laser light source.

The laser projection device according to claim 1, wherein green among short-wavelength laser light sources is configured by wavelength conversion.

A hole having a short wavelength laser light source that emits laser light of at least three colors of red, blue, and green, and provided with a laser beam of three colors of red, blue, and green from the short wavelength laser light source. Projector that transmits light.

The laser projection device according to claim 11, wherein a laser beam is not transmitted around the hole, and each pixel of the screen is aligned with the hole.

The laser projection apparatus according to claim 12, further comprising an angle selection element that limits a scattering range of the laser light scattered by the air holes.

The laser projection apparatus according to claim 13, wherein the angle selection element is configured to limit a scattering range using a lens array in which transmitted light is limited to a specific angle range.

The laser projection apparatus according to claim 14, wherein the angle width of scattering of each laser beam in the holes by the angle selection element is limited to 30 degrees or less.

The laser projection apparatus according to claim 11, wherein the short wavelength laser light source is modulated.

17. The laser projection device according to claim 16, wherein the modulation of the short wavelength laser light source is synchronized with the hole, and the short wavelength laser light source is modulated so that the output of the laser beam is maximized when reaching the center of the hole. .

The laser projection device according to claim 11, wherein a laser beam is projected from the back of the screen and an image is viewed from the front of the screen.

19. The laser projection apparatus according to claim 18, wherein a semiconductor laser is used as the short wavelength laser light source.

The laser projection device according to claim 18, wherein green of the short wavelength laser light source is configured by wavelength conversion.

21. The laser projection apparatus according to claim 20, wherein a fundamental wave semiconductor laser is modulated in order to modulate the wavelength-converted light of the green laser.