JPS6247016A - Focal length detection - Google Patents
Focal length detectionInfo
- Publication number
- JPS6247016A JPS6247016A JP18710285A JP18710285A JPS6247016A JP S6247016 A JPS6247016 A JP S6247016A JP 18710285 A JP18710285 A JP 18710285A JP 18710285 A JP18710285 A JP 18710285A JP S6247016 A JPS6247016 A JP S6247016A
- Authority
- JP
- Japan
- Prior art keywords
- focal length
- light
- receiving element
- light source
- convex lens
- 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
- 238000001514 detection method Methods 0.000 title claims description 21
- 230000003287 optical effect Effects 0.000 claims abstract description 15
- 230000004907 flux Effects 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 7
- 241000251468 Actinopterygii Species 0.000 description 6
- 230000000694 effects Effects 0.000 description 3
Landscapes
- Measurement Of Optical Distance (AREA)
- Focusing (AREA)
- Automatic Focus Adjustment (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、対象物の焦点を検出する焦点距離検出方法に
関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a focal length detection method for detecting the focus of an object.
従来の焦点距離検出装置の原理の一例を第２図に示す。 An example of the principle of a conventional focal length detection device is shown in FIG.
図示するように、被写体１からの光はレンズ２、ファイ
ンダースクリーン３及びリレーレンズ４，５を通してセ
ンサ６．７に導かれる。As shown, light from object 1 is directed to sensor 6.7 through lens 2, finder screen 3, and relay lenses 4, 5.
上記構成の焦点距離検出装置において、焦点が合ってい
れば、センサ６．７の中央に結像されるが、焦点距離が
合っていなければ結像はセンサ６．７の中央からずれる
から、このずれにより焦点距離を検出することができる
。In the focal length detection device having the above configuration, if the focus is correct, the image will be formed at the center of the sensor 6.7, but if the focal length is not correct, the image will be shifted from the center of the sensor 6.7. The focal length can be detected based on the shift.
しかしながら従来の焦点距離を検出する装置は、三角測
量法を用いた一部の装置を除き、対照物を照らすための
光源を装置に内蔵していない。However, conventional devices for detecting focal length do not have a built-in light source for illuminating a target object, except for some devices that use triangulation.
そのため、周囲が暗い条件下では焦点の検出が困難とな
るか若しくは不可能となるという欠点があった。Therefore, there is a drawback that detection of the focus becomes difficult or impossible under dark surroundings.
本発明は上述の点に鑑みてなされたもので、周囲が暗い
条件下でも検出が可能な焦点距離検出方法を提供するこ
とにある。The present invention has been made in view of the above points, and it is an object of the present invention to provide a focal length detection method that allows detection even under dark surroundings.
上記問題点を解決するため本発明は、対象物を照らす光
を発する光源、対象物からの反射光を受光する受光素子
及び前記光源からの光を前記対象物に導き、更に対象物
からの反射光を前記受光素子に導くレンズ及びミラー等
を有する光学系を具備し、前記光源からの光が前記光学
系を通し対象物に導かれ、該対象物から反射された光を
受光素子で受光することにより光学系の焦点距離と対象
物の位置とが一致しているか否かを検出するように構成
した。In order to solve the above problems, the present invention provides a light source that emits light that illuminates an object, a light receiving element that receives reflected light from the object, and a light receiving element that guides the light from the light source to the object. An optical system having a lens, a mirror, etc. that guides light to the light receiving element is provided, the light from the light source is guided to an object through the optical system, and the light reflected from the object is received by the light receiving element. Accordingly, it is configured to detect whether the focal length of the optical system and the position of the object match.
焦点検出方法を」−２の如く構成することにより、焦点
距離を検出するための対象物を照らず光源が内蔵されて
おり、該光源からの光で対象物を照らすようにするから
周囲が暗い条件下でも焦点距離を検出することが可能と
なる。By configuring the focus detection method as in ``-2'', the surrounding area is dark because the light source is built-in and the object is illuminated with light from the light source instead of illuminating the object for detecting the focal length. It becomes possible to detect the focal length even under such conditions.
以下、本発明の一実施例を図面を用いて説明する。 An embodiment of the present invention will be described below with reference to the drawings.
第１図は本発明に係る焦点距離検出装置の原理を示す図
である。同図において、１１は焦点距離Ｆの凸レンズで
あり、１２は２面の鏡を一辺で接合してなる断面三角形
状の鏡である。鏡１２の頂部１２ａは凸レンズ１１の光
軸と一致した位置にあり、該凸レンズ１１を透過する全
光束を左右に２分割する。凸レンズ１１から鏡１２の右
面１２ｂを通る焦点距離の位置に焦光＠１３を配置し、
凸レンズ１１から鏡１２の右面１２ｃを通る焦点距離の
位置に魚受光素子１４を配置する。FIG. 1 is a diagram showing the principle of a focal length detection device according to the present invention. In the figure, 11 is a convex lens with a focal length F, and 12 is a mirror with a triangular cross section formed by joining two mirrors together on one side. The top portion 12a of the mirror 12 is located at a position that coincides with the optical axis of the convex lens 11, and divides the total luminous flux passing through the convex lens 11 into two left and right. A focal beam @13 is placed at a focal length from the convex lens 11 passing through the right surface 12b of the mirror 12,
A fish light-receiving element 14 is arranged at a focal distance from the convex lens 11 to the right surface 12c of the mirror 12.
上記凸レンズ１１及び鏡１２から構成される光学系を具
備する焦点距離検出装置の動作を第３図、第４図、第５
図を用いて説明する。第３図は対象物体１５が凸レンズ
１１の焦点距離にある場合、第４図は焦点距離が焦点距
離手前にある場合、第５図は対象物が焦点距離前方にあ
る場合である。The operation of the focal length detection device equipped with the optical system composed of the convex lens 11 and mirror 12 is shown in FIGS. 3, 4, and 5.
This will be explained using figures. 3 shows a case where the target object 15 is at the focal length of the convex lens 11, FIG. 4 shows a case where the focal length is in front of the focal length, and FIG. 5 shows a case where the target object is in front of the focal length.
第３図において、点光源１３から発せられた光束１６は
鏡１２の右面１２ｂで反射され凸レンズ１１を通って対
象物１５に到達して結像する。該対象物１５により反射
された光束１７は、凸レンズ１１を通り鏡１２の左面１
２ｃで反射きれ魚受光素子１４に達し結像する。従って
、該魚受光素子１４が点光源１３からの光を受光したら
対象物が凸レンズ１１の焦点距離上にあることになる。In FIG. 3, a light beam 16 emitted from a point light source 13 is reflected by the right surface 12b of the mirror 12, passes through the convex lens 11, reaches the object 15, and forms an image. The light beam 17 reflected by the object 15 passes through the convex lens 11 and reaches the left surface 1 of the mirror 12.
At 2c, the reflected light reaches the fish light receiving element 14 and forms an image. Therefore, when the fish light receiving element 14 receives light from the point light source 13, the object is located on the focal length of the convex lens 11.
対象物１５が焦点距離の手前或いは前方にある場合は、
第４図及び第５図に示すように点光源１３からの光束１
６と対象物１５からの反射光束１７の間に交わる点がな
いから、点光源１３から発せられた光束１６は魚受光素
子１４に受光されることがかい７
上述の如く上記構成の焦点距離検出装置によれば、装置
内部に焦点距離を検出するための対象物１５を照らす点
光源１３を内蔵しているので、周囲が暗い条件子でも焦
点の検出が可能となる。If the object 15 is in front of or in front of the focal length,
As shown in FIGS. 4 and 5, a luminous flux 1 from a point light source 13
6 and the reflected light beam 17 from the object 15, the light beam 16 emitted from the point light source 13 is likely to be received by the fish light receiving element 14. As described above, focal length detection with the above configuration According to the device, since the point light source 13 that illuminates the object 15 for detecting the focal length is built into the device, the focal point can be detected even in a dark conditioner.
なお−Ｆ記例では、凸レンズ１１を透過する全光束を２
分割する手段として鏡１２を用いたが、透過光を区分す
る手段としては鏡１２に限定されるものではなく、例え
ばプリズム等の光学部品を用いてもよいことは当然であ
る。また、光学系を構成するレンズも一個に限定される
ものではなく、要は所定の焦点距離を有し光源からの光
を対象物に導きさらに対象物により反射される反射光を
受光素子に導く光学系であればよい。In addition, in the example -F, the total luminous flux passing through the convex lens 11 is 2
Although the mirror 12 is used as a means for dividing the transmitted light, the means for dividing the transmitted light is not limited to the mirror 12, and it goes without saying that an optical component such as a prism may be used. Furthermore, the lenses constituting the optical system are not limited to one lens; in short, they have a predetermined focal length, guide light from the light source to the object, and guide reflected light reflected by the object to the light-receiving element. Any optical system is sufficient.
第６図は本発明に係る他の焦点距離検出装置の構成を示
す図である。該焦点距離検出装置は、−第１図に示す焦
点距離検出装置の魚受光素子１４に替えて小さな受光素
子を直線状に配列してなる直線状受光素子１８を用いた
もので、対象物が焦点距離の手前か前方か或いは手前又
は前方のどの位置にあるかを検出することが可能な焦点
距離検出装置である。FIG. 6 is a diagram showing the configuration of another focal length detection device according to the present invention. This focal length detecting device uses a linear light receiving element 18 formed by linearly arranging small light receiving elements in place of the fish light receiving element 14 of the focal length detecting device shown in FIG. This is a focal length detection device that can detect whether the object is in front or in front of the focal length, or which position is in front or in front of the focal length.
上記構成の焦点距離装置の動作を第７図、第８図、第９
図を用いて説明する・
対象物が第７図に示すように焦点距離Ｆの位置にある場
合は、点光源１３から発せられた光束１６は鏡１２の右
面で反射され凸レンズ１１を通って対象物１５を照射し
、該対象物１５により反射された光束１７は凸レンズ１
１を通り、鏡１２の左面１２ｃにより反射され直線状受
素子１８上の中央Ａの受素子に入射し、これにより対象
物１５が凸レンズ１１の焦点距離と一致した位置にある
ことが検知される。The operation of the focal length device with the above configuration is shown in FIGS. 7, 8, and 9.
Explain using a diagram. When the target object is at a focal length F as shown in FIG. A light beam 17 that illuminates an object 15 and is reflected by the object 15 passes through a convex lens 1
1, is reflected by the left surface 12c of the mirror 12, and enters the receiving element at the center A on the linear receiving element 18, whereby it is detected that the object 15 is at a position that matches the focal length of the convex lens 11. .
対象物が焦点距離Ｆの手前にある時は、第８図に示すよ
うに、点光源１３から発せられた光束１６は、前述のよ
うに鏡１２の右面１２ｂ５凸レンズ１１を経て対象物１
５に照射され、該対象物により反射された光束１７は直
線状受光素子１８の受光面上に第１０図に示すような広
がりを持った光束として受光される。When the object is in front of the focal length F, as shown in FIG.
The light beam 17 irradiated onto the object 5 and reflected by the object is received on the light-receiving surface of the linear light-receiving element 18 as a light beam with a spread as shown in FIG.
対象物が焦点距離Ｆの前方にある時は、第９図に示すよ
うに、点光源１３から発せられた光束１６は、前述のよ
うに鏡１２の右面１２ｂ、凸レンズ１１を経て対象物１
５に照射され、該対象物により反射された光束１７は直
線状受光素子１８の中央Ａ点から０点の間の受光素子に
入射される。When the object is in front of the focal length F, as shown in FIG.
The light beam 17 irradiated onto the object 5 and reflected by the object is incident on the linear light receiving element 18 between the center point A and the zero point.
焦点距離装置は第７図に示す如く構成することにより、
直線状受光素子１８の中央Ａ点からＢ点側或いは０点側
の受光素子に反射光が入射された場合は、対象物１５が
焦点距離Ｆより手前或いは前方にあるから、凸レンズ１
１又は焦点距離装置全体或いは対象物１５の光軸方向に
前後に移動させることにより、対象物１５の位置と焦点
距離とを一致させることが可能となる。By configuring the focal length device as shown in FIG.
When reflected light is incident on the light receiving element from the center A point of the linear light receiving element 18 to the B point side or the 0 point side, since the object 15 is in front of or near the focal length F, the convex lens 1
1 or the entire focal length device or the object 15 by moving it back and forth in the optical axis direction, it is possible to match the position of the object 15 with the focal length.
なお、上記実施例において、点光源１３としては例えば
レーザー光源を用い、魚受光素子１４及び直線状受光素
子１８に該レーザー光源からの波長のレーザー光にのみ
感じる受光素子を用いることにより、光ノイズ等により
焦点距離の検出に誤差を生ずる等の問題がなくなる。In the above embodiment, for example, a laser light source is used as the point light source 13, and the fish light receiving element 14 and the linear light receiving element 18 are light receiving elements that are sensitive only to laser light of the wavelength from the laser light source, thereby reducing optical noise. This eliminates problems such as errors in focal length detection.
以上説明したように本発明によれば、焦点距離を検出す
るための対象物を照らす光源を内部に装備しているから
周囲が暗い条件下でも対象物の焦点を検出することが可
能となるという優れた効果が得られる。As explained above, according to the present invention, since the light source that illuminates the object for detecting the focal length is installed inside, it is possible to detect the focus of the object even under dark surroundings. Excellent effects can be obtained.
第１図は本発明に係る焦点距離検出装置の原理を示す図
、第２図は従来の焦点距離検出装置の原理を示す図、第
３図、第４図、第５図はそれぞれ第１図に示す焦点距離
検出装置の動作を説明するだめの図、第６図は本発明に
係る他の焦点距離検出装置の原理を示す図、第７図、第
８図、第９図はそれぞれ第６図に示す焦点距離検出装置
の動作を示す図、第１０図は直線状受光素子部分を示す
拡大図である。Fig. 1 is a diagram showing the principle of a focal length detection device according to the present invention, Fig. 2 is a diagram showing the principle of a conventional focal length detection device, and Figs. 3, 4, and 5 are respectively similar to Fig. 1. 6 is a diagram showing the principle of another focal length detection device according to the present invention, and FIGS. 7, 8, and 9 are diagrams for explaining the operation of the focal length detection device shown in FIG. FIG. 10 is an enlarged view showing the linear light-receiving element portion.
Claims (3)
反射光を受光する受光素子と、前記光源からの光を前記
対象物に導きさらに対象物からの反射光を前記受光素子
に導く光学系とを具備し、前記光源からの光が前記光学
系を通し対象物に導かれ、該対象物により反射され該光
学系を通して導かれた光を前記受光素子で受光すること
により、前記対象物の位置と前記光学系の焦点距離との
一致を検出することを特徴とする焦点距離検出方法。(1) A light source that emits light that illuminates a target object, a light-receiving element that receives reflected light from the target object, and guides the light from the light source to the target object, and further guides the reflected light from the target object to the light-receiving element. an optical system, the light from the light source is guided to a target object through the optical system, and the light that is reflected by the target object and guided through the optical system is received by the light receiving element. A focal length detection method, comprising detecting coincidence between the position of an object and the focal length of the optical system.
対象物で反射された光が該直線状受光素子のどの位置に
入射されたかにより、対象物の焦点距離からのずれを検
出することを特徴とする特許請求の範囲第（１）項記載
の焦点距離検出方法。(2) A linear light-receiving element is used as the light-receiving element, and the deviation from the focal length of the object is detected based on where on the linear light-receiving element the light reflected by the object is incident. A focal length detection method according to claim (1).
子として該レーザー光源からの波長のレーザー光にのみ
感じる受光素子を用いることを特徴する特許請求の範囲
第（１）又は（２）項記載の焦点距離検出方法。(3) A laser light source is used as the light source, and a light-receiving element that is sensitive only to laser light of a wavelength from the laser light source is used as the light-receiving element. Focal length detection method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18710285A JPS6247016A (en) | 1985-08-26 | 1985-08-26 | Focal length detection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18710285A JPS6247016A (en) | 1985-08-26 | 1985-08-26 | Focal length detection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6247016A true JPS6247016A (en) | 1987-02-28 |
Family
ID=16200139
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18710285A Pending JPS6247016A (en) | 1985-08-26 | 1985-08-26 | Focal length detection |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6247016A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0331713A (en) * | 1989-06-28 | 1991-02-12 | Dainippon Screen Mfg Co Ltd | Dislocation detecting mechanism |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54155832A (en) * | 1978-05-30 | 1979-12-08 | Canon Inc | Focusing detector |
| JPS59165030A (en) * | 1983-03-10 | 1984-09-18 | Canon Inc | auto focus camera |
-
1985
- 1985-08-26 JP JP18710285A patent/JPS6247016A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54155832A (en) * | 1978-05-30 | 1979-12-08 | Canon Inc | Focusing detector |
| JPS59165030A (en) * | 1983-03-10 | 1984-09-18 | Canon Inc | auto focus camera |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0331713A (en) * | 1989-06-28 | 1991-02-12 | Dainippon Screen Mfg Co Ltd | Dislocation detecting mechanism |
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