Dainippon Screen Seizo Kabushiki-kaisha

Dainippon Screen Mfg. Co., Ltd.

Norimasa Nomura

Masaji Mizuta

Nobuhiro Takita

Atsushi Yoshida

Hiroshi Taniguchi

Masami Ohtani

Yoshihiro Masuda

Tomiji Hotta

Yozi Dohi

Yasuhito Yoshimi

Disclosed are method and device for automatically controlling the time period of photographic development for each specific combination of a photographic developer and a photosensitive material for the purpose of obtaining a substantially same or optimum photographic development result at various temperatures. Through utilization of the knowledge of a certain relation between the time period of photographic development and the temperature of the photographic developer which will produce a same photographic development result, the time period of photographic development is adjusted, for instance, by changing the speed of a conveyor carrying the photosensitive material through the photographic developer. The mentioned relationship may not be always expressed by a linear function with a desired accuracy but may be approximated with a desired accuracy by means of various mathematical functions such as polynomials and irrational functions.

Method and device for automatically developing photosensitive material

A method and apparatus for controlling the activity of a developing solution against oxidation by using a test piece for use in an automatic developer. Differences N.sub.4 -N.sub.4 ' and N.sub.5 -N.sub.5 ' between first and second standard densities N.sub.4 and N.sub.5 measured at first and second points of a first test piece developed in a standard developing solution and first and second densities N.sub.4 ' and N.sub.5 ' measured at the same points of a second test piece of the same type as the first one as the same points of the first test piece, developed in a developing solution to be controlled, are obtained. An operating time T of constant-flow supplementing means is calculated according to a formula T=K.sub.1 [K.sub.3 (N.sub.4 -N.sub.4 ')-(N.sub.5 -N.sub.5 ')]+K.sub.2 wherein K.sub.1, K.sub.2 and K.sub.3 are first, second and third predetermined oxidation factors, and then the constant-flow supplementing means is actuated for the obtained operating time T, thereby supplementing a supplementary solution to the developing solution to be controlled in order to restore its activity. A permissible density range may be determined, in which no activity control is performed.

Method and apparatus for controlling activity of developing solution

A method and apparatus for controlling the activity of a developing solution against blackening by using a test piece for use in an automatic developer are disclosed. A difference between a standard density measured at the predetermined point of the first test piece developed in a standard developing solution, and a density measured at the same point of the second test piece of the same type as the first test piece as said predetermined point of the first test piece, developed in a developing solution to be controlled, is obtained. Then, a predetermined factor is multiplied by the thus obtained density difference to obtain a control value, and then the activity of the developing solution is controlled according to the control value, such as adding a supplementary solution against the blackening to the developing solution to be controlled or putting an exposed film into the same. A permissible density difference range may be determined, in which no activity control is performed.

The insertion of exposed film into a developing tank 1 is detected by a detector 12, by which a pump motor 8 is operated by a control circuit 20, to agitating continuously the developing solution filled in the tank, and simultaneously a pulse counter 16 stars counting pulses generated from a pulse generator 14. The continuous agitation of the developing solution is suspended when the film is discharged from the tank, which is measured by counting up to the predetermined number which corresponds to the time required for the film treatment in the tank. When the pulse counter 16 counts up to the predetermined number, the intermittent agitation of the developing solution is started by the control circuit 20, to keep the developing solution uniform.

Film processor with agitation means

An automatic film developer having a film guide means, wherein a film exposed is developed while it is conveyed in a developing liquid in a liquid tank, and then the film developed is taken out of the liquid along a contact surface of a film guide means in order to be transferred to a next process, and wherein the film guide means is provided with a recess in its contact surface so that the film may be separated from the contact surface in the recess portion.

Automatic film developer having a film guide means

An automatic film feeder for an automatic developer wherein films exposed are processed through a developing tank, and wherein the films put in trays arranged above an endless belt which feeds the films into the developer, are ejected from the trays onto the belt by film ejectors of the same number as the trays, a control means controlling the ejectors so that the films may be ejected in the desired order and may be fed to the developer one by one without overlapping one on another.

Growing community of inventors

Kyoto, Japan

Norimasa Nomura