Patent ID: 6052538
Filing Date: 2000-04-18
Classification: G03B

Abstract:
A camera for use with a roll photo film, said roll photo film including a photo filmstrip having an effective exposure region in which plural frames are formable one after another, a light-shielding leader disposed on a front end of said photo filmstrip, a light-shielding trailer disposed on a rear end of said photo filmstrip, said roll photo film being pre-wound with said trailer wound inwards and with said leader wound outwards, and including a bar code, prerecorded between a front end of said leader and said effective exposure region, for representing photo film information including information of an auto input photosensitivity value, said camera comprising:a bar code reader for reading said bar code to detect said auto input photosensitivity value;a variable photosensitivity input unit, externally operable, for inputting a manual input photosensitivity value;a mode selector, externally operable, for selecting one of automatic and manual modes, said mode selector rendering said auto input photosensitivity value effective when selecting said automatic mode, and rendering said manual input photosensitivity value effective when selecting said manual mode;an exposure control unit for controlling an amount of exposure to said effective exposure region in accordance with an effective one of said auto and manual input photosensitivity values;a photo film take-up chamber, formed in said camera body, for taking up said roll photo film with said leader advanced thereto;a take-up spool which is disposed in said take-up chamber in a removable manner, on which said front end of said leader is retained and which winds said roll photo film thereabout when rotated;a drive shaft, engaged with said take-up spool, for rotating said take-up spool;a first rotary encoder for generating a pulse representing a unit axial rotating amount of said drive shaft, said unit axial rotating amount corresponding to a unit transported amount of said roll photo film; anda counter for counting said pulse to detect an axial rotating amount of said drive shaft;said bar code reader including:a photo sensor for detecting a reflection level of said bar code;a control unit for obtaining a distance where said reflection level of said bar code is stable by referring to said axial rotating amount in response to signals from said counter and said photo sensor, so as to obtain a width of said bars;a driven roller, disposed near to said take-up spool, and rotated by said photo filmstrip in contact therewith; anda second rotary encoder for detecting a unit roller rotating amount of said driven roller, said unit roller rotating amount being adapted to control of said photo filmstrip for one-frame advancement.