JPS5832691B2 - Overhead projector unit - Google Patents
Overhead projector unitInfo
- Publication number
- JPS5832691B2 JPS5832691B2 JP50129108A JP12910875A JPS5832691B2 JP S5832691 B2 JPS5832691 B2 JP S5832691B2 JP 50129108 A JP50129108 A JP 50129108A JP 12910875 A JP12910875 A JP 12910875A JP S5832691 B2 JPS5832691 B2 JP S5832691B2
- Authority
- JP
- Japan
- Prior art keywords
- gear
- arm
- projection lens
- stage
- rotatably supported
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Overhead Projectors And Projection Screens (AREA)
- Projection Apparatus (AREA)
Description
【発明の詳細な説明】
本発明はオーバーヘッドプロジェクタ−における画面修
正装置、更に詳しくはオーバーヘッドプロジェクタ−に
お（・てミラーの仰角を変えて投影画面の高さを変えた
時に生ずるキーストン効果による画面のゆがみを修正す
る装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a screen correction device for an overhead projector, and more specifically, to an overhead projector (in which the height of the projection screen is changed by changing the elevation angle of the mirror). The present invention relates to a device for correcting distortion.
周知のように、オーバーヘッドプロジェクタ−（以下Ｏ
ＨＰと略称する。As is well known, overhead projector (hereinafter referred to as O
It is abbreviated as HP.
）にお℃・て、単にミラーの仰角を変えてスクリーン上
の投影画面の位置を高くしようとすると、キーストン効
果によって画面の上方部分が拡がって画面がゆがむとＬ
・う問題がある。), if you try to raise the position of the projection screen on the screen by simply changing the elevation angle of the mirror, the upper part of the screen will expand due to the keystone effect and the screen will become distorted.
・There is a problem.
周知のように、ステージ、投影レンズ、スクリーンの３
者が平行、すなわち光軸に対して前記３者が等角度で傾
Ｌ・て（・る時には、このキーストン効果は生じなＬ・
。As is well known, there are three stages: a stage, a projection lens, and a screen.
When the three members are parallel to each other, that is, the three members are tilted at equal angles to the optical axis, this keystone effect does not occur.
.
したがって上記のような画面のゆがみを修正するために
は、投影レンズとステージとを平行を保って動かしミラ
ーの仰角の変化θに対して２倍の角度２θだげミラーと
同方向に傾げるようにすればよし・。Therefore, in order to correct the above-mentioned screen distortion, the projection lens and the stage must be kept parallel to each other, and the angle 2θ, which is twice as large as the change θ in the elevation angle of the mirror, should be tilted in the same direction as the mirror. It's okay if you do.
このような方法によって画面を修正する装置は従来より
提案されてＬ・るが、従来のこのような装置は複雑な歯
車の連動機構等を使用し、高価であった。Devices for correcting screens using such a method have been proposed in the past, but such devices have been expensive because they have used complicated interlocking mechanisms of gears.
本発明は極めて簡単な構造によって、ミラー、ステージ
、投影レンズを前記のような関係を保って動かし、画面
のゆがみをなくすようにしたＯＨＰにおける画面修正装
置を提供せんとするものである。The present invention aims to provide a screen correction device for an OHP that has an extremely simple structure and moves the mirror, stage, and projection lens while maintaining the above-mentioned relationship to eliminate screen distortion.
本発明の修正装置は一端を回動自在に軸支され、その回
動によってステージと投影レンズを平行に回動させるよ
うにしたアーム、そのアームの他端に回転自在に軸支さ
れ、かつ□ラーに連結されたセクターギヤ、前記アーム
の中間部に回転自在に軸支され、前記セクターギヤと噛
合する中間ギヤ、およびこの中間ギヤと噛合し、前記ア
ームと同軸に固定される回転不能の固定ギヤとからなり
、前記セクターギヤと固定ギヤのギヤ比を２＝１とした
ことを特徴とするものである。The correction device of the present invention includes an arm that is rotatably supported at one end, and whose rotation rotates the stage and the projection lens in parallel; the arm is rotatably supported at the other end of the arm; a sector gear connected to the arm, an intermediate gear that is rotatably supported in the middle of the arm and meshes with the sector gear, and a non-rotatable fixing that meshes with the intermediate gear and is fixed coaxially with the arm. The gear is characterized in that the gear ratio between the sector gear and the fixed gear is 2=1.
このように構成された本発明の修正装置によれば、アー
ムの回動に伴って、セクターギヤ、中間ギヤおよび固定
ギヤの噛合によってアームの回動角度の丁度半分の角度
だけセクターギヤが反対方向に回転する。According to the correction device of the present invention configured in this manner, as the arm rotates, the sector gear is moved in the opposite direction by exactly half the rotation angle of the arm due to the meshing of the sector gear, intermediate gear, and fixed gear. Rotate to.
したがって、ミラーはアームと同方向に同角度だけ回動
しり２アームの回動角度すｉわちステージと投影レンズ
の回動角度の丁度半分の角度だけ、セクターギヤの回転
によって反対方向に戻されることになる。Therefore, the mirror rotates by the same angle in the same direction as the arm, and is returned to the opposite direction by the rotation of the sector gear by an angle that is exactly half the rotation angle of the two arms, that is, the rotation angle of the stage and projection lens. It turns out.
したがって、ステージおよび投影レンズの回動角度がミ
ラーの回動角度の丁度２倍になるようにして３者が動く
から、ミラーの仰角を変えてもキーストン効果が起きる
ことがな”ｏ （この原理につＬ゛ては後に図をもっ
て詳述する。Therefore, since the three parties move so that the rotation angle of the stage and projection lens is exactly twice the rotation angle of the mirror, the keystone effect will not occur even if the elevation angle of the mirror is changed. The details will be explained later in detail with reference to figures.
）しかも本発明の構成によれば構造が極めて簡単であり
、かつ安価である。) Moreover, according to the configuration of the present invention, the structure is extremely simple and inexpensive.
以下図面を参照して本発明の実施例を詳細に説明する。Embodiments of the present invention will be described in detail below with reference to the drawings.
第１Ａ図および第１Ｂ図は本発明の詳細な説明するため
の図である。FIG. 1A and FIG. 1B are diagrams for explaining the present invention in detail.
第１Ａ図にお（・てアーム１が軸１ａによって回動自在
に軸支されてＬ・る。In FIG. 1A, an arm 1 is rotatably supported by a shaft 1a.
このアーム１に第１の歯車２と中間歯車３が回転自在に
軸支され、互Ｌ・に噛合して（・る。A first gear 2 and an intermediate gear 3 are rotatably supported on this arm 1 and mesh with each other.
中間歯車３に第２の歯車４が噛合してし・る。The second gear 4 meshes with the intermediate gear 3.
この第２の歯車４はアーム１と同軸に固定された回転不
能の固定歯車であり、第１の歯車とのギヤ比が１：２に
なって（・る。This second gear 4 is a non-rotatable fixed gear fixed coaxially with the arm 1, and has a gear ratio of 1:2 with respect to the first gear.
ここでアーム１を第１Ａ図に示す位置から第１Ｂ図に示
すように反時計方向に角θだげ回動させると、第１の歯
車２上の１点、例えば点Ａはアーム１の回動方向と同方
向に回動する。When the arm 1 is rotated counterclockwise by an angle θ from the position shown in FIG. 1A to the position shown in FIG. 1B, a point on the first gear 2, for example, point A, is Rotates in the same direction as the movement direction.
この時、点Ａの回動角度は、もし前記３個の歯車２．３
．４が噛合してち・なければ当然θに等しＬ・。At this time, the rotation angle of point A is, if the three gears 2.3
．． If 4 is not engaged, it is naturally equal to θ and L.
しかしながら、ここではアーム１０反時計方向の回動に
よって、中間歯車３が固定された第２の歯車４との噛合
によって反時計方向に回動せし、められ、したがって、
第１の歯車２が中間歯車３によって時計方向に回転せし
められるから、点Ａは第１の歯車２の回転角度分だけ時
計方向に戻される。However, in this case, as the arm 10 rotates counterclockwise, the intermediate gear 3 is rotated counterclockwise by meshing with the fixed second gear 4, and is set.
Since the first gear 2 is rotated clockwise by the intermediate gear 3, point A is returned clockwise by the rotation angle of the first gear 2.
この時第１の歯車と第２の歯車のギヤ比が２：１である
から、第１の歯車の時計方向への回転角度はアーム１の
反時計方向への回動角度θの半分のθ／２となる。At this time, since the gear ratio of the first gear and the second gear is 2:1, the clockwise rotation angle of the first gear is θ, which is half of the counterclockwise rotation angle θ of arm 1. /2.
したがって点Ａはアーム１の回動角度の丁度半分だけ反
時計方向に回動することになる。Therefore, point A rotates counterclockwise by exactly half the rotation angle of arm 1.
以下この原理図と対照しながら本発明の一実施例を説明
する。An embodiment of the present invention will be described below in contrast with this principle diagram.
第２図は本発明の一実施例を示す側面図、第３図図はそ
の斜視図である。FIG. 2 is a side view showing one embodiment of the present invention, and FIG. 3 is a perspective view thereof.
第２図におＬ゛て、ＯＨＰボディ１０の支柱１０ａの上
端部付近に軸１１ａによって、第１のアーム１１と第２
のアーム１２が４５°の角度で接続すして（・るＶ字型
レバー１３が軸支されても・る。As shown in FIG. 2, a shaft 11a connects the first arm 11 and the second
The arm 12 is connected at an angle of 45° (even if the V-shaped lever 13 is pivoted).
第１のアーム１１には反射ミラー１４を一体的に有する
第１のセクターギヤ（ミラー回動ギヤ）１５が軸１５ａ
によって回動自在に軸支されてＬ・る。A first sector gear (mirror rotating gear) 15 that integrally has a reflecting mirror 14 is attached to the first arm 11 and has a shaft 15a.
It is rotatably supported by L.
第２のアーム１２には投影レンズ１６が一体的に固着さ
れて℃・る。A projection lens 16 is integrally fixed to the second arm 12.
また支柱１０ａの上端部には回転不能の第２のセクター
ギヤ１７が一体的に形成されており、前記第１のアーム
１１の中間部に回転自在に軸支され、かつ第１のセクタ
ーギヤ１５と噛合している中間ギヤ１８と噛合している
。Further, a non-rotatable second sector gear 17 is integrally formed at the upper end of the support column 10a, and is rotatably supported by the intermediate portion of the first arm 11. The intermediate gear 18 is in mesh with the intermediate gear 18 which is in mesh with the intermediate gear 18 .
第１のセクターギヤ１５は軸１５ａを中心とする仮想線
で描いたギヤ１５ｂの一部をなすもので、前記原理図の
第１の歯車２に相当する。The first sector gear 15 forms part of a gear 15b drawn by an imaginary line centered on the shaft 15a, and corresponds to the first gear 2 in the principle diagram.
第２のセクターギヤ１７はＶ字型レバー１３の軸１１ａ
を中心とする仮想線で描℃・たギヤ１７ａの一部をなす
もので、原理図の第２の歯車４に相当する。The second sector gear 17 is the shaft 11a of the V-shaped lever 13.
It forms part of the gear 17a drawn by an imaginary line centered at , and corresponds to the second gear 4 in the principle diagram.
前記ギヤ、１５ｂとギヤ１７ａとのギヤ比は２：１にな
ってＬ・る。The gear ratio between the gear 15b and the gear 17a is 2:1, which is L.
アーム１１および中間ギヤ１８はそれぞれ前記原理図の
アーム１、中間歯車３に相当する。The arm 11 and the intermediate gear 18 correspond to the arm 1 and the intermediate gear 3 in the principle diagram, respectively.
したがって、前述のようにアーム１１が角θだげ回動す
るとミラー１４は角θ／２“だけ回動することになる。Therefore, as described above, when the arm 11 rotates by an angle θ, the mirror 14 rotates by an angle θ/2''.
さらに、支柱１０ａの下端にはステージ２０が軸２０ａ
によって回動自在に軸支されて（・る。Furthermore, a stage 20 is mounted on a shaft 20a at the lower end of the support column 10a.
It is rotatably supported by (・ru.
このステージ２０は弧状のラックギヤ２１を一体的に有
してＬ・て、ハンドル２２によって回転せしめられるピ
ニオン２３の時計方向への回転によって反時計方向に回
動せしめられるようになってＬ・る。This stage 20 integrally has an arc-shaped rack gear 21, and is rotated counterclockwise by clockwise rotation of a pinion 23 rotated by a handle 22.
ステージ２０とレバー１３の第２のアーム１２は、一端
をアーム１２に他端をステージ２０に回転自在に軸支さ
れてＬ・るリンク棒２４によって連結されて（・て、両
者が平行を保って回動するよ５になってＬ・る。The stage 20 and the second arm 12 of the lever 13 are connected by an L-shaped link rod 24 that is rotatably supported by the arm 12 at one end and the stage 20 at the other end (so that the two remain parallel). It will rotate and become 5 and L・ru.
また前記ミラー１４はステージ２０が水平の時には第１
のアーム１１と一直線をなすように、すなわち水平面と
４５°の角度をなすように設定されてＬ・る。Further, the mirror 14 is the first mirror when the stage 20 is horizontal.
It is set so as to be in line with the arm 11 of L, that is, to form an angle of 45° with the horizontal plane.
以上の構成から明らかなように、ハンドル２２を時計方
向に回転させるとステージ２０と投影レンズ１６が平行
を保ちながら反時計方向に回動する。As is clear from the above configuration, when the handle 22 is rotated clockwise, the stage 20 and the projection lens 16 are rotated counterclockwise while maintaining parallelism.
したがって第１のアーム１１はステージ２０と投影レン
ズ１６０回動角度と等し〜・角度だけ反時計方向に回動
し、ミラー１４はその半分の角度だけ反時計方向に回動
する。Therefore, the first arm 11 rotates counterclockwise by an angle equal to the rotation angle of the stage 20 and the projection lens 160, and the mirror 14 rotates counterclockwise by an angle equal to the rotation angle of the stage 20 and the projection lens 160.
したがって、ハンドル２２を時計方向に回すことによっ
て、ステージ２０と投影レンズ１６を平行に保ちながら
傾げることができ、かつ両者の傾き角度の１／２の角度
だけミラー１４の仰角を変えることができる。Therefore, by turning the handle 22 clockwise, the stage 20 and the projection lens 16 can be tilted while keeping them parallel, and the elevation angle of the mirror 14 can be changed by an angle of 1/2 of the tilt angle of both.
この３者が上記のような関係を保ってＬ・るから、ミラ
ー１４の仰角を変えてもキーストン効果による画面のゆ
がみが生じなＬ・。Since these three maintain the above-mentioned relationship, even if the elevation angle of the mirror 14 is changed, screen distortion due to the keystone effect will not occur.
しかも、本発明の構成によれば、構造が極めて簡単であ
り、したがって安価である。Moreover, according to the configuration of the present invention, the structure is extremely simple and therefore inexpensive.
第１Ａ、１Ｂ図は本発明の原理を示す原理図、第２図は
本発明の一実施例を示す側面図、第３図はその斜視図で
ある。
１１・・・第１のアーム、１２・・・第２のアーム、１
４・・・ミラー １５・・・第１のセクターギヤ、１６
、・・投影レンズ、１７・・・第２のセクターギヤ、１
８・・・中間ギヤ、２０・・・ステージ。1A and 1B are principle diagrams showing the principle of the present invention, FIG. 2 is a side view showing an embodiment of the invention, and FIG. 3 is a perspective view thereof. 11...first arm, 12...second arm, 1
4... Mirror 15... First sector gear, 16
,... Projection lens, 17... Second sector gear, 1
8... intermediate gear, 20... stage.
Claims (1)
ち・て水平軸のまわりに回動自在に軸支された投影レン
ズ１６、この投影レンズ１６に対して平行を保って水平
軸のまわりに回動する投影原稿載置用ステージ２０、こ
のステージ２０および投影レンズ１６０回動に連動して
回動するよう前記ボディの上方におち・て水平軸のまわ
りに回動自在とされたアーム１１．そのアーム１１と同
軸に固定された回動不能の固定ギヤ１７、前記アーム１
１に回転自在に軸支され前記固定ギヤ１７と噛合する中
間ギヤ１８、および前記アーム１１に回転自在に軸支さ
れ、□ジー１４に連結された、前記中間ギヤ１８と噛合
するミラー回動ギヤ１５とからなり、前記固定ギヤ１７
と□ラー回動ギヤ１５とのギヤ比が１：２であり、投影
レンズ１６とステージ２０を平行を保って回動させ、そ
の両者の回動角度の２分の１だけ□ジー１４を同方向に
回動させるようにしたことを特徴とするオーバーヘッド
プロジェクタ−における画面修正装置。1. A projection lens 16 mounted above the body of the overhead projector and rotatably supported around a horizontal axis, and a projection original rotating around the horizontal axis while remaining parallel to the projection lens 16. A mounting stage 20, an arm 11 which is placed above the body and is rotatable around a horizontal axis so as to rotate in conjunction with the rotation of the stage 20 and the projection lens 160. a non-rotatable fixed gear 17 fixed coaxially with the arm 11;
an intermediate gear 18 that is rotatably supported by the arm 11 and meshes with the fixed gear 17; and a mirror rotating gear that is rotatably supported by the arm 11 and connected to the □ gee 14 and meshes with the intermediate gear 18. 15, and the fixed gear 17
The gear ratio between the and □r rotation gear 15 is 1:2, and the projection lens 16 and the stage 20 are rotated while maintaining parallelism, and the □gear 14 is rotated by half of the rotation angle of both. 1. A screen correction device for an overhead projector, characterized in that the screen correction device is configured to rotate in a direction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP50129108A JPS5832691B2 (en) | 1975-10-27 | 1975-10-27 | Overhead projector unit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP50129108A JPS5832691B2 (en) | 1975-10-27 | 1975-10-27 | Overhead projector unit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5253425A JPS5253425A (en) | 1977-04-30 |
| JPS5832691B2 true JPS5832691B2 (en) | 1983-07-14 |
Family
ID=15001253
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP50129108A Expired JPS5832691B2 (en) | 1975-10-27 | 1975-10-27 | Overhead projector unit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5832691B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4863263A (en) * | 1987-02-13 | 1989-09-05 | Minolta Camera Kabushiki Kaisha | Overhead projector |
| US5530496A (en) * | 1993-03-05 | 1996-06-25 | Fuji Photo Optical Co., Ltd. | Overhead projector |
| US5622417A (en) * | 1995-11-01 | 1997-04-22 | Lightware, Inc. | Invertible and orthoscopic liquid crystal display projector |
| KR100200143B1 (en) * | 1996-07-31 | 1999-06-15 | 전주범 | Beam-projection angle adjusting system for projector |
| US5722752A (en) * | 1997-01-10 | 1998-03-03 | In Focus Systems, Inc. | Multimedia projection system with image quality correction |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4831847A (en) * | 1971-08-27 | 1973-04-26 |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS527587Y2 (en) * | 1972-05-15 | 1977-02-17 |
-
1975
- 1975-10-27 JP JP50129108A patent/JPS5832691B2/en not_active Expired
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4831847A (en) * | 1971-08-27 | 1973-04-26 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5253425A (en) | 1977-04-30 |
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