Abstract: Optical scanning of a moving sheet of image-bearing material is carried out in a stand-alone apparatus. No drive is provided for the sheet in the scanning apparatus, and the sheet accelerates therethrough under its own momentum and under its own weight. Transmittance scans from an optical sensor are obtained at a uniform frequency, and are analysed to determine the final speed of the sheet. Computation then allows the data to be corrected such that the detected transmittance can be related to the actual area of the sheet under acceleration. The transmittance of the sheet is then combined with its measured area to determine the amount of image present on the sheet. The invention finds application in photoprocessing apparatus, and a signal dependent on the amount of image present on the sheet and its area is sent back to the photoprocessor to control the amount of replenishment chemicals added to the processing tanks.

Abstract: A processed sheet of photographic film is guided into a channel of scanning equipment in which it is subjected to light from an elongate fluorescent tube. Light transmitted through the film is detected by a sensing arrangement in the form of an elongate solar cell strip. The strip is scored so as to divide it into 3 small subsidiary sensors and four longer sensors. All seven sensors form the main light sensor. As the leading edge of the film, which is assumed to be of uniform light density, enters the channel and totally obscures at least one of the subsidiary sensors, that sensor measures the transmittance of the film. This value, together with the reduction in light sensed by the main sensor, is then used to determine the width of the film. The film width is combined with the separately computed film length, to provide a signal used to control the amount of replenishment chemicals to be supplied to a photoprocessor.

Abstract: Described herein is a buffer device for use with photographic processing apparatus which provides a buffer for solution being fed to or collected from the apparatus. The buffer device (18) comprises a flexible plastic concertina-shaped container (30) having a volume appropriate to the apparatus with which it is to be used. The container (30) is preferably constructed to be normally-closed and requires liquid pressure to open it. The container (30) is fixed at its upper end (38) and its lower end (40) is free to move downwardly when liquid enters it. An index member (32) is attached to the lower end (40) and this member (32) cooperates with a position sensor to indicate to an operator whether the container (30) is "not empty", "not full" or "full".

Abstract: Described herein is a portable film processing arrangement which is housed in a case-like receptacle comprising a base portion and a lid portion. Base portion 10 houses a plurality of processing units 30 which accommodate spiral holders onto which film to be processed can be wound automatically. Lid portion 14 houses a plurality of containers 18,19,20 which contain processing chemicals for processing the film. The chemicals are fed to the processing units 30 from the containers 18,19,20 as required by valves which are controlled by an on-board computer in a control section 45 located in the base portion 10 between the processing units 30.

Abstract: It is known to use infra-red densitometry to measure the variations in the optical density of photographic material. In photographic processing apparatus, it is important that the photographic material is transferred from one part of the apparatus to another at precisely the correct time to prevent damage to the material. Described herein is a method and apparatus for controlling the transfer or switching of photographic material from one processing tank to another of photographic processing apparatus during processing of the material. A threshold detector (30) is used to produce an output signal (40) indicative of a change in infra-red density of the photographic material. The output signal (40) is then used to control the transfer or switching of the material from one processing tank to another.

Abstract: In photographic processing, the chemistry needs to be replenished periodically in order to produce optimum results. Known replenishment systems utilize replenishers in liquid form which are dispensed according to volume. These systems require the use of a pump which is both accurate and relatively inexpensive. Described herein is a replenishment system which uses a weighing system with a series of intermediate containers to dispense replenishment materials. The system comprises a weighing device which has three intermediate containers supported on it. Each container is connected to its associated processing stage by a pipeline. Flow of replenisher materials from each container is controlled by respective valves which are interfaced with a computer. The computer is also interfaced with the weighing device and monitors the decrement in weight of the intermediate containers so that the exact amount of replenisher materials can be added.

Abstract: An automatic film processing device replenishment system where an infra red sensor is located to measure silver content of the image on a film or paper carrier, and use the measured silver content for control of replenishment of the process chemicals. In a preferred arrangement a first infra red sensor measures silver content and controls replenishment of developer and bleach and a second infra red sensor measures silver halide content and controls replenishment of fixer.

Abstract: In known film processing techniques, the amount by which a film is processed at each stage is determined chiefly by time. If a film is either over- or underexposed, it may be incorrectly processed producing unsatisfactory results. The present invention utilises an arrangement which measures changes in the infrared density of the film during processing to ensure that satisfactory results are produced. The arrangement comprises an infrared light emitting diode (22) and an infrared sensitive photodiode detector (26) which are both mounted in a support (20). Film (34) passes between the diode (22) and the detector (26) so that the amount of infrared radiation being transmitted through the film can be determined to provide a measure of the infrared density of the film at each stage during its processing.