Ryobi Limited

Other

Hideki Doumoto

Takashi Kimura

Yutaka Fujii

Yuuki Watanabe

Takahiko Shinmoto

In a double-sided color printing press, first and second color bars of a print are scanned to acquire alignment information of control patches, so that the first and second color bars are recognized whether they are printed on the first or second side of the print based on the alignment information. The alignment information of the patches acquired is compared with alignment information previously stored in a memory means so that when they are matched, information on the print quality of the patches evaluated is transmitted to the printing press in the order in which they are scanned in scanning directions, and when they are not matched, the information is transmitted to the printing press in the reversed scanning order. The amount of ink is thus controlled based on the information on the print quality in the order in which they are transmitted.

Method of recognizing color bars on double-sided color prints, color print quality control system and color print quality evaluation apparatus

The present invention provides a method of detecting the locations of right and left register marks respectively burned onto right- and left-hand side portions of a printing plate based upon image data of images respectively captured within an image processing area with right and left vertical edges respectively extending in the Y-direction, and upper and lower horizontal edges extending in the X-direction. The method includes detecting the center coordinates in the X-direction of the right and left register marks based upon the image data obtained from substantially the entire portion of the image data processing area; detecting the center coordinate in the Y-direction of the right register mark based upon the image data obtained from a right-hand side portion of the image data processing area extending up to at least the center coordinate in the X-direction of the right register mark; and detecting the center coordinate in the Y-direction of the left register mark based upon the image data obtained from a left-hand side portion of the image data processing area extending up to at least the center coordinate in the X-direction of the left register mark.

Printing plate processing apparatus and method of detecting the location of a register mark on a printing plate

An image adjusting device for an offset printing machine includes a drive source, an adjustment gear mounted on a rotary shaft and always engaged with a gear mounted on a blanket cylinder for adjusting a position of an image to be printed, a clutch mechanism for selectively transmitting a rotation of the drive source to the adjustment gear, and an encoder for controlling a rotational amount of the adjustment gear, the encoder being mounted on the rotary shaft. Further the image adjusting device has first and second detectors for detecting the rotational positions of the blanket cylinder and a cylinder gear, respectively, a microcomputer provided with calculating means for calculating standard and present phase differences between the blanket cylinder and the cylinder gear, and an input means for inputting an amount of adjustment on the basis of the present phase difference therebetween. Thus, it is possible to more correctly effect the image adjustment in the offset printing press.

Image adjusting device for offset printing machine

An apparatus and method for controlling a plurality of connected continuous paper printing machines connected in series prevent difference in rotational speeds of the connected printing machines from causing the paper between the printing machines from piling up or tearing. Signal generators count the number of sheets of continuous paper entering each printing machine. The difference in the number of sheets entering each printing machine is calculated and compared to preset upper and lower limits. If an upstream printing machine turns faster than a downstream printing machine, slack will develop in the paper between the printing machines, and the difference between the sheets entering the upstream printing machine and sheets entering the downstream printing machine will be a (+) value. When a preset upper limit is reached, a controller will temporarily stop the upstream printing machine until the downstream printing machine takes up all the slack. Similarly, if the downstream printing machine turns faster than the upstream printing machine, paper between the printing machines will become taut, and the difference between sheets entering the upstream printing machine and sheets entering the downstream printing machine will be a (-) value. When a preset lower limit is reached, another controller will temporarily stop the downstream printing machine until the tautness is relieved.

Apparatus and method for controlling a plurality of continuous paper

A sheet-fed press includes a front guide device which performs a positional adjustment of a printing sheet before transferring it to a transfer drum. In order to adjust an image forming portion on the printing sheet, both ends of a front guide rod are moved independently of each other. Moving distances of the both ends of the rod are computed by a central processing unit on the basis of a paper size, etc.

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Fuchu, Japan

Hideki Doumoto