JPH0175209U

JPH0175209U -

Info

Publication number: JPH0175209U
Application number: JP1987170645U
Authority: JP
Priority date: 1987-11-10
Filing date: 1987-11-10
Publication date: 1989-05-22

Description

[Brief explanation of the drawing]

第１図、第２図および第３図は、いずれも本考
案に係る測距用補助光投射装置の実施例の構成を
示す平面図、側面図および斜視図、第４図は、上
記実施例を自動焦点カメラに適用した例を示し、
特に該自動焦点カメラの明暗パターンを検出する
検出方向と明暗パターンの配列方向との関係を示
す斜視図、第５図および第６図は、いずれも従来
例を示す側面図で、このうち第５図は光源が大き
い場合、第６図は光源が小さい場合のものである
。１……光源、２……レンズ、３……シリンドリ
カルフレネルレンズ（フレネルレンズ）、４……
明暗パターン、４ａ……明部、４ｂ……暗部、５
……被写体面、６……自動焦点（ＡＦ）カメラ、
７……撮影レンズ、８……補助光投射装置、９…
…検出方向、１０……非検出方向、Ｌ１〜Ｌ５…
…分割光束、Ｓ……平面。 1, 2, and 3 are a plan view, a side view, and a perspective view showing the configuration of an embodiment of the distance measuring auxiliary light projection device according to the present invention, and FIG. An example of applying this to an autofocus camera is shown.
In particular, the perspective view, FIGS. 5 and 6, which show the relationship between the detection direction for detecting the light-dark pattern of the autofocus camera and the arrangement direction of the light-dark pattern, are both side views showing the conventional example. The figure shows the case where the light source is large, and FIG. 6 shows the case where the light source is small. 1... Light source, 2... Lens, 3... Cylindrical Fresnel lens (Fresnel lens), 4...
Light and dark pattern, 4a...Bright area, 4b...Dark area, 5
...Subject plane, 6...Auto focus (AF) camera,
7...Photographing lens, 8...Auxiliary light projection device, 9...
...Detection direction, 10...Non-detection direction, L1 to L5...
...Divided luminous flux, S...plane.

Claims

[Scope of utility model registration request]

In order to maintain the distance measurement accuracy of an autofocus camera that uses a phase detection method when the subject brightness is low, fill-in light consisting of a luminous flux divided into multiple parts is projected onto the subject, and a light and dark pattern corresponding to the above divisions is created. A distance measuring auxiliary light projection device that forms a light beam on the subject surface includes a lens that focuses light from a relatively small light source into a parallel beam or a loosely diverging beam and passes it through, and a lens that receives the light beam that has passed through this lens and directs it to the The camera is equipped with a cylindrical Fresnel lens that divides the light into a plurality of light beams at different angles in the detection direction in which the light and dark patterns are detected, and allows the light to pass through in a direction perpendicular to the detection direction as a parallel light beam or a loosely diverging light beam. An auxiliary light projection device for distance measurement, characterized in that the light beam emitted from the cylindrical Fresnel lens is configured to project a bright and dark pattern onto the subject from a short distance to a long distance.