Dainippon Screen Seizo Kabushiki-kaisha

Dainippon Screen Mfg. Co., Ltd.

Nobuhiro Takita

Masaji Mizuta

Norimasa Nomura

Hiroshi Taniguchi

Tadashi Shintani

Takashi Sakamoto

Masamichi Cho

Yasuo Kurusu

Kunio Tomohisa

Yutaka Tamura

Akihiro Nomura

Takashi Ohmori

Yosuke Shimamoto

Hiroichi Tada

Experiential gradation correction curves for sample images are prepared. By analyzing the experiential gradation correction curves and accumulated density histograms of the sample images, two points (Y.sub.1, Q.sub.1) and (Y.sub.2, Q.sub.2) are specified, where Y.sub.1 and Y.sub.2 are values of accumulated occurrence and Q.sub.1 and Q.sub.2 are halftone dot percentages for image reproduction. The values Y.sub.1 and Y.sub.2 through an accumulated density histogram of an original image whose gradation is to be corrected. A gradation correction curve Q=G(x) is determined so as to pass through the two points (x.sub.1, Q.sub.1) and (x.sub.2, Q.sub.2).

Method of generating gradation correction curve for correcting gradation

Methods and apparatus for avoiding moire occurring in color scanning for graphic art, wherein light rays from a color original are passed through a pick-up lens, and prior to starting the color scanning, are modulated by means of a low-pass filter, which modulated rays are branched into two optical paths, on one of the paths a lattice plane is provided so as to project the modulated rays thereon, the lattice plane being beforehand selected in accordance with various conditions for scanning. A possible moire on the lattice plane is observed thereby to adjust the low-pass filter by replacement or displacement until the moire disappears on the lattice plane. Finally the light rays from the color original are modulated by the selected low-pass filter.

Methods and apparatus for avoiding moire in color scanners for graphic

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.

A film squeegee mechanism of an automatic film developing apparatus including developing, fixing and washing means. Film squeegee means incorporated in the film transport means contacting with film to be treated with proper pressure and relative speed to film surface are provided between two liquid treating tanks of film transport means of the automatic film developing apparatus, scraping off liquid and minimizing the amount of treating liquids carried over by the film from one tank to the next.

Film squeegee mechanism of automatic film developing apparatus

In a film conveyor for use in developing films comprising a first and a second belt racks consisting of a plurality of narrow belts and pressure rollers, and a roller rack consisting of a plurality of squeegee rollers and spray tubes arranged between said two belt racks, the pressure rollers of the two belt racks are so positioned as to press the belts at the mid points of two vertically adjacent squeegee rollers, and the squeegee rollers of the roller rack are arranged in two vertical rows between which an adequate number of said spray tubes are horizontally disposed so that developing solution may be sprayed out directly toward between said two rows of squeegee rollers. Further, the squeegee rollers of the roller rack are driven in synchronism with the moving speed of the belts so as to effect smooth conveyance of the film held between the belts and the squeegee rollers.

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Kyoto, Japan

Nobuhiro Takita