Abstract: A retroreflective photoelectric sensor has a light-emitting optical system having a light-emitting element and a first polarizer and serving to transmit light from the light-emitting element through the first polarizer, a light-receiving optical system having a second polarizer and a light-receiving element and serving to convert light received through the second polarizer into an electrical signal by the light-receiving element, the first and second polarizers having mutually perpendicular polarizer axes, a single lens for both emitting light from the light-emitting element and receiving light to the light-receiving element therethrough, a beam splitter serving to direct light received from the light-emitting optical system to the single lens and light received from the single lens to the light-receiving optical system, and a phase shifter inserted between the light-emitting optical system and the single lens.

Abstract: A retroreflective photoelectric sensor has a light-emitting optical system having a light-emitting element and a first polarizer and serving to transmit light from the light-emitting element through the first polarizer, a light-receiving optical system having a second polarizer and a light-receiving element and serving to convert light received through the second polarizer into an electrical signal by the light-receiving element, the first and second polarizers having mutually perpendicular polarizer axes, a single lens for both emitting light from the light-emitting element and receiving light to the light-receiving element therethrough, a beam splitter serving to direct light received from the light-emitting optical system to the single lens and light received from the single lens to the light-receiving optical system, and a phase shifter inserted between the light-emitting optical system and the single lens.

Abstract: A retroreflective photoelectric sensor may be of a biaxial type or of a coaxial type. A sensor of the biaxial type includes a light-emitting optical system having a light-emitting element, a first polarizer and a light-emitting lens arranged sequentially in this order, a light-receiving optical system having a light-receiving lens, a second polarizer and a light-receiving element arranged sequentially in this order, and a phase shifter inserted between the first polarizer and the light-emitting lens of the light-emitting optical system. The polarizer axes of the first and second polarizers are mutually perpendicular. A phase shifter such as a ½ wave plate may further be placed between the first polarizer and the light-emitting lens of the light-emitting optical system.

Abstract: A retroreflective photoelectric sensor may be of a biaxial type or of a coaxial type. A sensor of the biaxial type includes a light-emitting optical system having a light-emitting element, a first polarizer and a light-emitting lens arranged sequentially in this order, a light-receiving optical system having a light-receiving lens, a second polarizer and a light-receiving element arranged sequentially in this order, and a phase shifter inserted between the first polarizer and the light-emitting lens of the light-emitting optical system. The polarizer axes of the first and second polarizers are mutually perpendicular. A phase shifter such as a ½ wave plate may further be placed between the first polarizer and the light-emitting lens of the light-emitting optical system.

Abstract: A waterproof lens-fitted photo film unit includes a lens-fitted photo film unit. Between a case body and a rear lid, the lens-fitted photo film unit is contained in a watertight manner. A separation opening is formed in the case body. A separation access chamber has an entrance connected to the separation opening, and closes the separation opening in a watertight manner in a position interior with reference to the case body. The separation access chamber includes a thin wall having a small thickness, and is breakable by a separator tool having a long shape with a small width.

Abstract: A film winding unit is removably attached to a film unit so as to engage a coupling gear with a film winding wheel. The coupling gear is connectable to a gear train through a clutch member. While the film winding wheel of the film unit is unlocked, the clutch member is placed in a power transmitting position for transmitting rotational movement of a motor to the coupling gear through the gear train. Upon the film winding mechanism being locked, a large load is applied to the clutch member, so that the clutch member slips into a disconnecting position to disconnect the motor from the coupling gear. In cooperation with the movement of the clutch member into the disconnecting position, a motor inactivating device inactivates the motor. After a release button of a film winding unit is depressed to depress a shutter button of the film unit, a motor activating device activates the motor in cooperation with returning movement of the release button.

Abstract: A price printer for printing prices relative to photographic processing, which is suitable for a printer-processor for printing image recorded on photographic films onto photographic papers. The price printer is disposed in a position where each image printed on the photographic paper is detected. The number of defective prints selected by detection is input by an operator. The number of the defective prints is subtracted from the total number of prints which is automatically input from the printer-processor to calculate the number of prints to be delivered to a customer and compute a print price to be printed. Therefore, a proper statement of delivery can be made at a time and the efficiency of work can be improved. A photographic-film carrier capable of automatically detecting information about the length of a processed photographic film can be provided. The price printer can read the length information so as to determine the kind of the photographic film and automatically set and print a development price.