Abstract: A method of reading a bar code formed on an object subjected to information detection employs a plurality of light and dark pattern detecting members which are disposed in the bar code reading direction within the widthwise dimension of a single clock bar in the reading direction. The light and dark pattern of one of the clock bars is detected by one of the light and dark pattern members, and the light and dark pattern of another clock bar adjacent to the first-mentioned clock bar is detected by another light and dark pattern detecting member which is located such as to correspond to the second-mentioned clock bar. The detected light and dark patterns are compared with each other, whereby light and dark portions constituting the bar code are discriminated from each other on the basis of relative brightness. Thus, it is possible to prevent the occurrence of a read error in relation to the light and dark portions of the bar code.

Abstract: A photographic film having a bar code formed in the vicinity of one side edge thereof is longitudinally moved while being guided by a mount. An optical fiber bundle which moves while following one widthwise end surface of the photographic film reads the bar code on the film. The optical fiber bundle follows any change in width of the photographic film and therefore constantly coincides with the bar code to effect correct reading thereof.

Abstract: A photographic printing apparatus for printing an image formed on a negative film on photographic paper includes a shutter disposed between the photographic paper and an enlarging lens. A reflective surface is provided on the surface of the shutter on the side thereof which is closer to the enlarging lens. A light receiver is disposed outside the optical path of exposure light in such a manner as to face the reflective surface. When the shutter is closed, the light receiver receives the light which forms an out-of-focus image at the reflective surface and is reflected therefrom. Accordingly, it is possible to measure an averaged density of the film image.