Dainippon Screen Seizo Kabushiki-kaisha

Dainippon Screen Mfg. Co., Ltd.

Masaji Mizuta

Fumihiko Nishida

Koichi Fujii

Norimasa Nomura

Nobuhiro Takita

Hiroshi Taniguchi

Tomiji Hotta

Atsushi Yoshida

Makoto Urata

Isamu Itoi

Minoru Kinoshita

Tomohiro Yoshida

Yasumasa Shimizu

Hiroshi Yamashita

A device for supplying/discharging PS plates in an inclined-type step and repeat machine having a rearwardly inclined exposing table which includes a supplying holder disposed on a side of the exposing table for supplying the PS plate thereto, the holder having a surface thereof rearwardly inclined at the same angle with respect to the horizontal as that of a surface of the exposing table, a pair of endless chains respectivley disposed along both side edges of the holder and adapted to move up and down longitudinally of the holder in synchronism with each other, metal support supported by the chains at both ends thereof, support bars also supported by the chains at respective both ends thereof via metal pieces the chains being driven to move up while carrying the PS plate which is being held by the metal support and support bars, and a guide provided on the top of the supplying holder and bent backwardly for guiding upward the plate being discharged.

Device for automatically supplying/discharging photosensitive material

Disclosed is a method of printing through a contact exposure in a step-and-repeat machine which is constituted by a photosensitive material holder for supporting a photosensitive material, an original film holder having a transparent base plate for fixedly holding an original film and having a holder frame defining a first chamber between the photosensitive material holder and the base plate, first suction means for holding the original film on the base plate, second suction means for evacuating air within the first chamber, and a light source disposed behind the original film for exposing the photosensitive material through the original film. The method comprises the steps of: actuating the first suction means to mount the original film fixedly on the base plate of the original holder by means of suction: positioning the original holder at a desired position on the photosensitive material; actuating the second suction means to evacuate air within the first chamber; decreasing the suction applied from the first suction means so as to effect the higher negative pressure within the first chamber than that applied by the first suction means, by which the original film contacts with the photosensitive material; and exposing the photosensitive material through the original film.

Method of printing through contact exposure in step-and-repeat machine

A one-way reducing and enlarging printer to print a reduced or enlarged image in one direction onto a photosensitive material comprising a photosensitive material holder to mount the photosensitive material, a negative holder having a light transmissive property to mount a negative at a position opposite to the photosensitive material, a light source, a douser having a slit opening and placed between the light source and the negative, and control device to control relative motion among the photosensitive material holder, the negative holder, and the douser by the signals from a signal generating device.

One-way reducing and enlarging printer

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.

Control means for a drier for films or sheets using a minimum of electric power. A heater is connected to a semiconductor switch and an alternating-current power supply in series. An oscillator outputs a pulse to a turn-on terminal of the semiconductor switch via an OR gate in synchronization with a certain phase angle of the wave form of the alternating voltage turning on the semiconductor switch for approximately 10% of the rated value of the heater thereby preheating the heater. When an entrance sensor detects the presence of films or sheets entering the drier, a starting signal is sent to a flip-flop circuit which outputs a high level signal to the turn-on terminal of the semiconductor switch via the OR gate activating the heater to full rated value. The high level signal is also sent to the turn-on terminal of a second semiconductor switch activating a second heater and a blower. When an exit sensor detects the presence of films or sheets leaving the drier, the exit sensor sends a stopping signal to the flip-flop circuit which outputs a low level signal turning off the second heater and blower and returning the first heater to the preheat phase.

Control means for a drier

An amplification-factor of the amplifier is controlled so as the output from a film-detecting-mechanism to be supplied as the input into a subtractor is adjusted fitting to a reference signal-prior to the film-insertion into the detecting mechanism. The output-signal from a comparator is supplied into the amplification-factor-variable-amplifier, in which the amplification-factor is controlled depending on the magnitude of the input-signal, and it is kept at the controlled value. Or an intensity of a light source is controlled so as the output from the film detecting mechanism to be supplied as the input into the subtractor is adjusted fitting to the reference-signal prior to the film-insertion into the detecting mechanism.

Film blackening area measuring equipment

A method and apparatus for automatically controlling an activity of a developing liquid for use in a developer are disclosed. A blackening area rate detector detects a blackening area rate of a film developed and outputs an analog signal to a voltage-frequency converter which converts it into a digital signal. The digital signal is sent to a dividing counter which frequency-divides it and outputs a supplement signal to an up-down counter. The up-down counter is counted up by the supplement signal to output a high level signal to a timer via a gate. The timer is actuated by the high level signal to actuate a valve so as to supply a supplemental developing liquid to a developing tank. The gate is closed by using the output signal of the timer during the actuation of the timer. The up-down counter is counted down by the high level signal passed through the gate.

Method and apparatus for automatically controlling an activity of a

A uniform developing method of a film for use in an automatic developer in which the film light-exposed is moved in developing solution in a developing vessel, wherein the moving speed of the film is gradually reduced depending on a deterioration rate of the developing solution with respect to the length of the film to be developed.

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Uji, Japan

Masaji Mizuta