JPH0360330U

JPH0360330U -

Info

Publication number: JPH0360330U
Application number: JP12254889U
Authority: JP
Priority date: 1989-10-19
Filing date: 1989-10-19
Publication date: 1991-06-13

Description

[Brief explanation of the drawing]

第１図は、本考案に係るフイルム給送検出装置
の一実施例を要部構成を示す断面図、第２図は、
同上実施例におけるフイルムの遮光部の検出状態
を示す断面図、第３図は、同上実施例を実装した
カメラの制御系のブロツク図、第４図は、第３図
のブロツク図におけるフオトリフレクタの部分を
主体に示す回路図、第５図は、同上実施例の動作
を説明するための相対光電流−距離特性図、第６
図，およびは、いずれも同上実施例におけ
るフオトリフレクタの受光部の出力処理を説明す
るためのタイムチヤート、第７図ａは、同上実施
例におけるフイルム面と反射板までの距離に焦点
距離を合わせた場合の受光部の出力レベルを示す
波形図、第７図ｂは、従来のフイルム孔の光電的
検出装置を有するカメラにおけるフイルム面と圧
板面の光路の光を検出する場合の受光素子の出力
レベルを示す波形図、第８図および第９図は、そ
れぞれ異なる従来のフイルム孔の光電的検出装置
を有するカメラの断面図、第１０図は、フイルム
の反射率の測定回路を示す回路図、第１１図は、
従来のフイルム孔の光電的検出装置を有するカメ
ラにおける受光素子の相対光電流−距離特性図で
ある。２１……レール面、２２……フイルム、２２ａ
……パーフオーレーシヨン、２３……フオトリフ
レクタ、２３ａ……発光部、２３ｂ……受光部、
２３ｃ……投受光面、２４……圧板、２４ａ……
透光孔、２５……裏蓋、２６……反射板、２７…
…給送検知回路、２８……中央処理装置、３１…
…操作スイツチ、３３……給送モータ用ドライバ
、３４……給送モータ。 FIG. 1 is a cross-sectional view showing the main structure of an embodiment of a film feed detection device according to the present invention, and FIG.
FIG. 3 is a block diagram of the control system of the camera implementing the above embodiment, and FIG. FIG. 5 is a circuit diagram mainly showing the above parts, and FIG. 5 is a relative photocurrent-distance characteristic diagram for explaining the operation of the same embodiment.
7A and 7B are time charts for explaining the output processing of the light receiving section of the photoreflector in the above embodiment, and FIG. Figure 7b shows the output level of the light receiving element when detecting light in the optical path between the film surface and the pressure plate surface in a camera having a conventional film hole photoelectric detection device. 8 and 9 are cross-sectional views of cameras having different conventional film hole photoelectric detection devices, and FIG. 10 is a circuit diagram showing a film reflectance measurement circuit. Figure 11 shows
FIG. 3 is a relative photocurrent-distance characteristic diagram of a light receiving element in a camera having a conventional film hole photoelectric detection device. 21...Rail surface, 22...Film, 22a
...perflation, 23...photoreflector, 23a...light emitting section, 23b...light receiving section,
23c... Light emitting/receiving surface, 24... Pressure plate, 24a...
Transparent hole, 25...Back cover, 26...Reflector, 27...
...Feeding detection circuit, 28...Central processing unit, 31...
...Operation switch, 33...Feeding motor driver, 34...Feeding motor.

Claims

[Scope of utility model registration request]

A film feed detection device that optically reads the perforation of a film and allows a predetermined film feed to be carried out, includes an automatic film feed mechanism that winds the film using a motor, and a rail surface or It has a light-emitting part and a light-receiving part for optically reading the perforation of the film, which are arranged on or near the rail surface and whose focal length is set to the distance from the vicinity to the reflection part provided on the back cover. a photoreflector disposed between the reflection section and the film, the light beam being emitted from the light-emitting section of the photoreflector toward the reflection section and reflected from the reflection section toward the light-receiving section; a pressure plate having a transparent hole through which the light beam passes; when the perforation of the film faces the photoreflector, the light is emitted from the light projecting section of the photoreflector; The light beam reflected by the reflecting section is detected by the light receiving section, and when the light shielding section between adjacent perforations faces the photoreflector, the light beam is emitted from the light projecting section of the photoreflector. 1. A film feed detection device characterized in that the light receiving section detects only a small amount of the light beam, excluding the light beam transmitted or absorbed by the light shielding section.