Dainippon Screen Mfg. Co., Ltd.

Dainippon Screen Seizo Kabushiki-kaisha

Minoru Kinoshita

Masaji Mizuta

Kiyoshi Sugou

Yukio Onoda

An amplification-factor of the amplifier is controlled so as the output from a film-detecting-mechanism to be supplied as the input into a subtractor is adjusted fitting to a reference signal-prior to the film-insertion into the detecting mechanism. The output-signal from a comparator is supplied into the amplification-factor-variable-amplifier, in which the amplification-factor is controlled depending on the magnitude of the input-signal, and it is kept at the controlled value. Or an intensity of a light source is controlled so as the output from the film detecting mechanism to be supplied as the input into the subtractor is adjusted fitting to the reference-signal prior to the film-insertion into the detecting mechanism.

Film blackening area measuring equipment

A photographic film blackened area measuring device, having two rod shaped light conducting members, each of which is formed as an elongated piece of transparent material with part of its surface, parallel to its axis, being roughened so as to diffuse light, while light is totally internally reflected along the length of the rod shaped member from the remainder of its smooth surface. These rod shaped light conducting members are arranged one on each side of a piece of developed photographic film in a automatic film developing machine, and the film passes between them. A light emitting device is provided at one end of one of the rod shaped light conducting members, and a photo sensitive device is provided at the end of the other rod shaped light conducting member which is remote from the light emitting device. Thereby, as the photographic film moves between the rods, fluctuations of the output of the light sensitive device are produced, depending on the total area of blackening of the photographic film, but substantially independent of the positioning and arrangement of said blackened area with respect to the edges of the film.

Growing community of inventors

Kyoto, Japan

Minoru Kinoshita