Minolta Company, Ltd.

Ryuichi Yasuhara

Akira Ogino

Yoshiyuki Inoue

Yoshiharu Tanaka

In a cartridge chamber of a camera is disposed a photoreflector to read a bar code formed on a disk attached to an end of a film spool. When a cartridge is loaded, the film spool is rotated more than one round in the direction to rewind the film. The photoreflector starts to read the bar code when supply of a driving force to rotate the spool is started. The leading part and the trailing part of the output signals of the photoreflector are compared in the reverse direction to find a point where signals corresponding to the constant rotation of the disk begin. The signals preceding the point are discarded and the initial position of the disk before it is rotated is determined based on the length of the signals truly representative of the bar code while the disk is rotating at the constant speed. Use condition of the film, unexposed, fully exposed, partly exposed or already developed, is judged from the initial position of the disk.

Device and method for detecting a rest position of a revolving body, and an apparatus equipped with such a device

A camera is loadable with a film cartridge having a rotary spool connected with a film and a bar code disk rotatable with the rotary spool and provided with a bar code for indicating photographing information of the film. While the rotary spool is being rotated, the bar code on the bar code disk is read by two readers to judge whether the film has been exposed. Code data is generated based on a read signal produced by the readers after the bar code disk rotates together with the rotary spool a predetermined rotation amount after the film is judged to have not been exposed, and is decoded into film information.

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Sakai, Japan

Ryuichi Yasuhara