Dainippon Screen Mfg. Co., Ltd.

Ricoh Company, Ltd.

Screen Holdings Co., Ltd.

Tsuyoshi Okuda

Takaharu Yamamoto

Shinsuke Yamashita

Hiroyuki Fuchioka

Kunio Ikefuji

Each unit of an inkjet printing station includes chains arranged along a transportation path of a web paper. A holding mechanism is fixedly arranged on the chain. The holding mechanism holds both ends of a paper passing bar to which the web paper is attached. Driving the chain with a handle causes the holding mechanism to move. The paper passing bar is delivered between the units adjoining each other. Therefore, the paper passing bar is movable from one end to the other end of the inkjet printing station formed by the units. Moreover, when specifications are changed for changing combination of the units, the combination can be made optionally.

Printing apparatus

A printing apparatus records a predetermined test pattern on printing paper, and reads the test pattern by means of a scanner. The scanner reads the test pattern at a resolution lower than the resolution of a recording head. This allows the automatic and fast reading of the test pattern. Additionally, the printing apparatus performs an interpolation process on read data, and judges whether there is an abnormality in nozzles or not, based on the read data subjected to the interpolation process. This reproduces the positions of and spacing between lines recorded on the printing paper with high accuracy to achieve the exact judgment as to whether there is an abnormality in the nozzles or not. Therefore, an inspection with a high degree of reliability is accomplished.

Printing apparatus, method of inspecting nozzles for abnormalities, and program

In a patch measurement device, a data storage section stores printed-image data including a control strip on a printed material. Based on the pixel values constituting printed-image data stored in the data storage section, a patch position detection section detects the position of a patch. A color density measurement section measures the color density of the patch whose position has been detected by the patch position detection section. A correlation coefficient &#x3c1;m between a key pattern x and subject data y which is calculated by a reference mark detection section is represented as &#x3c1;m=([x]*[y])&#x2212;([x]*[y]), where [x]*[y] is a sum of multiplication products of corresponding elements of the two matrices. Matrix [x]represents an inverted pattern of the key pattern x. Even if the subject data y is of an unrelated pattern resembling the key pattern x having different signal levels from those of the key pattern x, the resultant correlation coefficient &#x3c1;m has a small value, thereby indicative of a low correlation. The resultant correlation coefficient &#x3c1;m also becomes small if the subject data y is that of a solid patch, due to cancellation by a drastic subtraction.

Patch measurement device

A reading time setting section () determines a read area for an imaging section () on the basis of color chart positional data (id). The imaging section () reads an image on printing paper during the reading time and readout image data (rd) is stored in an image data storage section (). A reference mark detecting section () detects the positions of reference marks from the readout image data (rd). A color chart actual position calculation section () corrects a tilt of a color chart determined from the positions of the reference marks and calculates an actual position of each of color chart fields (cr). An image data readout section () reads out image data on a color chart field corresponding to the calculated actual position. At the same time, image data on a white color field immediately above the color chart field is also read out. A white color correction section () produces a white reference on the basis of the image data on the white color field and corrects the image data on the color chart field. A color chart information determination section () measures color chart information, such as a color density and a dot percentage, about each of the color chart fields. This printing press determines a reading time on the basis of the position of the color chart at the time of printing plate recording and thereby allows imaging of an area including the color chart on the printing paper being transported.

Printing press equipped with color chart measuring apparatus

A reading time setting section ( ) determines a read area for an imaging section ( ) on the basis of color chart positional data (id). The imaging section ( ) reads an image on printing paper during the reading time and readout image data (rd) is stored in an image data storage section ( ). A reference mark detecting section ( ) detects the positions of reference marks from the readout image data (rd). A color chart actual position calculation section ( ) corrects a tilt of a color chart determined from the positions of the reference marks and calculates an actual position of each of color chart fields (cr). An image data readout section ( ) reads out image data on a color chart field corresponding to the calculated actual position. At the same time, image data on a white color field immediately above the color chart field is also read out. A white color correction section ( ) produces a white reference on the basis of the image data on the white color field and corrects the image data on the color chart field. A color chart information determination section ( ) measures color chart information, such as a color density and a dot percentage, about each of the color chart fields. This printing press determines a reading time on the basis of the position of the color chart at the time of printing plate recording and thereby allows imaging of an area including the color chart on the printing paper being transported.

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Kyoto, Japan

Tsuyoshi Okuda