The invention relates, generally, to a film developer apparatus and, more particularly, to a roller tank system therefor.
Film developer apparatuses, such as those used to develop x-ray film, typically consist of a plurality of driven rollers for conveying an exposed film through a liquid developer bath, a liquid fixer bath and a rinsing bath. The developer and fixer baths typically consist of alkaline and acidic solutions, respectively, and the rinsing bath typically consists of water. After passing through these baths the film is dried by a hot air drier and dispensed from the developer apparatus.
In the known systems, the developer, fixer and rinsing solutions are contained in plastic or stainless steel tanks. These tanks are open at the top such that the film can be brought into contact with the solutions.
As is well known in the film developer art, the film can be brought into contact with the solutions by one of two methods. In the so called, "deep tank" method, a complex arrangement of transportation rollers or a transportation web moves the film through a serpentine path. These transport rollers or transport webs are arranged such that the film is conveyed into the tanks and is immersed in the solutions. One problem with such a transportation system is that the film must be bent so as to be able to travel through the serpentine path created by the rollers. This bending can damage the film. Moreover, to create the serpentine path a large member of rollers must be used such that these systems are relatively difficult and expensive to manufacture and maintain. Lastly, the pressure needed to transport the film along the serpentine path, whether by roller or by web, tend to leave marks on the film.
The other method of transporting film through a developer apparatus is the, so called, "straight through" method. In this method the rollers are arranged such that the film is conveyed horizontally in a straight line over the tops of the baths. Because the film is moved in a straight line, it cannot be immersed in the solutions. Therefore, a tray, through which the film travels, is disposed above each of the tanks. Solution from each of the tanks is continuously splashed onto the tray so as to contact both sides of the film as it passes through. While this method avoids bending the film, it is unable to immerse the film in the baths. As a result, the solutions must be continuously splashed onto the trays from the tanks. Because space is required between the rollers to accommodate the splashing apparatus, developers using this method are unable to handle small film such as dental x-rays.
Thus, an improved film developer that can immerse the film in solution without bending it and can handle film of virtually any size is desired.