JPS6094583A - Optical system for television projector - Google Patents
Optical system for television projectorInfo
- Publication number
- JPS6094583A JPS6094583A JP20341483A JP20341483A JPS6094583A JP S6094583 A JPS6094583 A JP S6094583A JP 20341483 A JP20341483 A JP 20341483A JP 20341483 A JP20341483 A JP 20341483A JP S6094583 A JPS6094583 A JP S6094583A
- Authority
- JP
- Japan
- Prior art keywords
- lens
- shape
- crt
- optical system
- image
- 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
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/72—Modifying the appearance of television pictures by optical filters or diffusing screens
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Transforming Electric Information Into Light Information (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明はＣＲＴの画像表示部に形成された画像を投影す
るためのテレビジ町ンプロジェクター用光学系の改良に
関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in an optical system for a television projector for projecting an image formed on an image display section of a CRT.
一般にＣＲＴ （陰極線管）は矩形の映像表示部をもっ
ていて、映像表示部の螢光面に電子ビームが当ることに
よりその点が発光し、電子ビームの偏光・走査により画
像が表示される。このＣＲＴの映像をテレビジョンプロ
ジェクタ−圧よって投影す部間様の明るさに投影される
にはＣＲＴの映像表示部に近接してこの対角線をカバー
するような凹レンズを設けて映像表示部より発した光を
次のコンデンサ光学系へと導くことが必要である。８こ
のＣＲＴの映像表示部に対向した凹レンズは、従来加工
及び調芯の容易なことからレンズ素材に関係なく、外周
形状を円形とすることがなされてきた。しかし映像表示
部の多くは円形ではなく４角形形状であるため、レンズ
外周形状を従来の円形とすると、結像に不要な光線を取
り込み迷光となって投影像のコントラストを下げたりフ
レアを発生し画質を低下させる欠点を有していた。また
結像に寄与しないレンズ部分を有するため忙、レンズの
大きさや重さは必要以上大きくなる。Generally, a CRT (cathode ray tube) has a rectangular image display section, and when an electron beam hits a fluorescent surface of the image display section, that point emits light, and an image is displayed by polarizing and scanning the electron beam. In order to project the CRT image with the same brightness as that of a television projector, a concave lens that covers the diagonal line should be provided close to the CRT image display section to emit light from the image display section. It is necessary to guide the emitted light to the next condenser optical system. 8. Conventionally, the concave lens facing the image display section of the CRT has been made to have a circular outer circumferential shape regardless of the lens material because it is easy to process and align. However, most video display sections are square rather than circular, so if the outer circumference of the lens were made circular, it would trap unnecessary rays of light for image formation and become stray light, lowering the contrast of the projected image and causing flare. It had the disadvantage of deteriorating image quality. Furthermore, since there is a lens portion that does not contribute to image formation, the size and weight of the lens become larger than necessary.
本発明は、上記の従来技術の欠点を解消し、画質の向上
とレンズの軽量コンパクト化を計ったテレビジ薔ンプロ
ジェクター用光学系を提供することを目的とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical system for a television projector that eliminates the drawbacks of the above-mentioned prior art, improves image quality, and makes the lens lightweight and compact.
上記目的は本発明のＣＲＴの映像部輪郭に対応したほぼ
４角形形状の物体側レンズを有することを特徴とするテ
レビジ曹ンプロジェクター用光学系により達成される。The above object is achieved by the optical system for a television projector according to the present invention, which is characterized by having an object side lens having a substantially rectangular shape corresponding to the outline of the image area of a CRT.
即ちＣＲＴ映像部輪郭は一般に矩形等の形状をなしてい
るところから、ＣＲＴ映像映像表示対圧対向配置する物
体側レンズをこの映像部輪郭に対応したはぼ矩形形状の
レンズ形状としたテレビジ璽ンブロジェクター用光学系
とするものである。That is, since the outline of the CRT image area is generally rectangular or the like, the object side lens placed opposite to the CRT image display is designed to have a roughly rectangular lens shape corresponding to the outline of the image area. This is an optical system for a projector.
第１図は本発明の１実施例を示した物体側レンズ１を示
すもので、第１図（ａ）は該レンズの正面図、第１図（
ｂ）はその側面図を示す。FIG. 1 shows an object-side lens 1 showing one embodiment of the present invention, FIG. 1(a) is a front view of the lens, and FIG.
b) shows its side view.
物体側レンズ１はアクリル等の透明樹脂を材料として型
成形した凹レンズであって、テレビプロジェクシ１１
＞用ＣＲＴの映像部輪郭が４角形のため、之にあわせて
４角形としたものである。これＫよりレンズ外周形状を
最外透過光束忙あわせて円形とした時よりも体積で３０
−以上小さくなっており、形状も大幅に小さくすること
ができる。The object side lens 1 is a concave lens molded from a transparent resin such as acrylic, and is
Since the outline of the image area of the CRT for 2008 is a rectangle, the outline of the image area is made into a rectangle to match this. From this K, the volume is 30% larger than when the outer peripheral shape of the lens is circular including the outermost transmitted light beam.
- or more, and the shape can also be made significantly smaller.
第２図（ａ）は上記実施例の対物レンズ１を用いたテレ
ビシロンプロジェクタ−用光学系を示すもので１２は凸
レンズ九３は補正用の弱い凹レンズの第３レンズである
。第２図（ｂ）は之に対して円形外形の対物レンズ１ａ
を用いたテレビジョンプロジェクタ−用光学系である。FIG. 2(a) shows an optical system for a telescope projector using the objective lens 1 of the above embodiment, and 12 is a convex lens 93 is a third lens which is a weak concave lens for correction. FIG. 2(b) shows an objective lens 1a having a circular outer shape.
This is an optical system for a television projector using.
ＣＲＴの矩形をした映像部輪郭の短辺に対し、光学的に
不要な部分を有した第２図（ｂ）に示す光学系では、側
線で示した不要光束がゴーストやフレアとなって結像の
コントラストを低下させる。従って第２図（ｂ）Ｋ示し
た従来の光学系では、レンズの光学的に不要な部分によ
るこれらの影響を避けるためにレンズの不要な部分への
墨塗り、或いは固定絞りを設けるといった対策がなされ
ていたが、第２図（ａ） Ｋ示す本発明では２吟を必要
としない。In the optical system shown in Fig. 2(b), which has an optically unnecessary portion on the short side of the rectangular image area outline of the CRT, the unnecessary light flux shown by the side line becomes a ghost or flare and forms an image. reduce the contrast of Therefore, in the conventional optical system shown in Fig. 2 (b) K, in order to avoid these effects caused by optically unnecessary parts of the lens, measures such as blacking out unnecessary parts of the lens or installing a fixed aperture are taken. However, the present invention shown in FIG. 2(a) K does not require 2 gins.
第３図は第２図（＆）Ｋ示した本発明のテレビジ１ンプ
ロジエクター用光学系を鏡体４に収めた実施例を示して
いる。この実施例では対物レンズ１と凸レンズ２との間
に９０’の角度で第１ミラーを、凸レンズ２と第３レン
ズ３との間忙も９４６の角度で第２ミラーを挿入したも
ので、対物レンズ１をＣＲＴの映像部に正対するように
鏡体４を設置するようにしたものである。FIG. 3 shows an embodiment in which the optical system for a television projector of the present invention shown in FIGS. In this embodiment, a first mirror is inserted between the objective lens 1 and the convex lens 2 at an angle of 90', and a second mirror is inserted between the convex lens 2 and the third lens 3 at an angle of 946'. A mirror body 4 is installed so that the lens 1 directly faces the image section of the CRT.
なお本実施例ではＣＲＴの４角形をした映像部輪郭に対
して対物レンズ１を正対するようにし、対物レンズ１は
ｉｔぼ対応した４角形形状としたが、対物レンズがＣＲ
Ｔの映像部に対してＸ〕おりを持って設置される場合に
はＣＲＴ上の結像範囲が不等辺４辺形となるため、対物
レンズのレンズ外形形状を之にあわせ非対称の異形状と
する場合も本発明に含まれる。In this embodiment, the objective lens 1 is set to directly face the rectangular image section outline of the CRT, and the objective lens 1 has a rectangular shape that corresponds to the outline of the CRT.
When the CRT is installed with an angle of X with respect to the image area of T, the imaging range on the CRT becomes a scalene quadrilateral. The present invention also includes cases where
本発明によるプレビジ冒ンプロジェクター用光学系は小
型・軽量で、且つフレアーやゴーストのない優れた結像
がなされる投影光学系が得られることとなった。The optical system for a pre-visual projection projector according to the present invention is small and lightweight, and provides excellent image formation without flare or ghost.
特に本発明による対物側レンズは、その形状から材質を
樹脂としコンプレッション成形等によって型成形による
ことが有利で、本発明はその成形材料の節約、成形時間
の短縮等の効果も生ずるものである。In particular, it is advantageous for the objective lens according to the present invention to be made of resin and molded by compression molding or the like because of its shape, and the present invention also produces effects such as saving molding materials and shortening molding time.
第１図は本発明の実施例を示す物体側レンズ、第２図は
テレビジョンプロジェクタ−用光学系の光路図を示した
もので、第２図（＆）は本発明ｊ（よるもの、第２図（
ｂ）は従来例によるもので、第３図は鏡体に収めた本発
明のテレビジョンプロジェクタ−用光学系を示す。
１．１ａ・・・・・・物体側レンズ ２・・・・・・凸
レンズ３・・・・・・第３レンズ ４・・・・・・釧体
代理人桑原義美Fig. 1 shows an object-side lens showing an embodiment of the present invention, Fig. 2 shows an optical path diagram of an optical system for a television projector, and Fig. 2 (&) shows an object-side lens showing an embodiment of the present invention. Figure 2 (
b) is a conventional example, and FIG. 3 shows an optical system for a television projector according to the present invention housed in a mirror body. 1.1a...Object side lens 2...Convex lens 3...Third lens 4...Yoshimi Kuwabara, the body agent
Claims (1)
レンズを有することを特徴とするテレビジ１ンプロジエ
クター用光学系。An optical system for a television projector, characterized by having an object-side lens having a substantially rectangular shape corresponding to the outline of an image section of a CRT.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20341483A JPS6094583A (en) | 1983-10-28 | 1983-10-28 | Optical system for television projector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20341483A JPS6094583A (en) | 1983-10-28 | 1983-10-28 | Optical system for television projector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6094583A true JPS6094583A (en) | 1985-05-27 |
Family
ID=16473675
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20341483A Pending JPS6094583A (en) | 1983-10-28 | 1983-10-28 | Optical system for television projector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6094583A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04261285A (en) * | 1990-10-18 | 1992-09-17 | Mitsubishi Electric Corp | Projection type television receiver |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5646376A (en) * | 1979-09-21 | 1981-04-27 | Hitachi Ltd | Projection type display |
-
1983
- 1983-10-28 JP JP20341483A patent/JPS6094583A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5646376A (en) * | 1979-09-21 | 1981-04-27 | Hitachi Ltd | Projection type display |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04261285A (en) * | 1990-10-18 | 1992-09-17 | Mitsubishi Electric Corp | Projection type television receiver |
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