Ricoh Company, Ltd.

Dainippon Screen Mfg. Co., Ltd.

Screen Holdings Co., Ltd.

Yuji Kurokawa

Takaharu Yamamoto

Kunio Muraji

Hiroshi Okamoto

Hiroyuki Fujisawa

Keisuke Hirayama

Hiroaki Kishida

Kazuyuki Tanoue

Hiroshi Asai

Atsushi Imamura

Hideaki Ogawa

Makoto Narazaki

Hitoshi Shioda

Ichiro Watanabe

Masaru Wakui

Okamoto Hiroshi

Disclosed is an inspecting chart including a reference pattern containing a first line segment group and a second line segment group, a first-side deviation pattern, and a second-side deviation pattern. The first line segment group is formed by a plurality of first line segments printed by a reference printing head at a first given interval. The second line segment is formed by second line segments printed by a printing head on a center between two adjacent first line segments or a center of each of the first line segments, the printing head being spaced away from the reference printing head in the transportation direction of a print medium. The first-side deviation pattern and the second-side deviation pattern are printed with various deviations.

Inspecting chart and printing apparatus

Disclosed is an inspecting chart including a reference pattern containing a first line segment group and a second line segment group, a first-side deviation pattern, and a second-side deviation pattern. The first line segment group is formed by a plurality of first line segments printed by a reference printing head at a first given interval. The second line segment is formed by second line segments printed by a printing head on a center between two adjacent first line segments or a center of each of the first line segments, the printing head being spaced away from the reference printing head in a the transportation direction of a print medium. The first-side deviation pattern and the second-side deviation pattern are printed with various deviations.

Disclosed is an inkjet printing apparatus including a printing head, an overcoating head discharging an overcoating agent, and a controller operating the printing head and the overcoating head to perform printing to a print medium. The controller operates in a normal discharge mode having a printing rate in the print medium relative to a given area of less than 100% for printing to the print medium, and an inspecting discharge mode having a printing rate in the print medium relative to the given area higher than the printing rate of the normal discharge mode for confirming a discharge state of the overcoating agent. In the inspecting discharge mode, the controller operates the printing head to form an inspecting region on the print medium, and operates the overcoating head to discharge the overcoating agent onto the inspecting region, whereby an overcoating inspecting chart is formed.

Inkjet printing apparatus and printing method of inspecting chart therewith

In a halftone image formed on a printing plate for letterpress printing, a minimum halftone dot has a square main cluster consisting of 9 pixels and four sub-clusters located around the main cluster radially, each of which is one pixel. Each sub-cluster contacts with only a vertex of the main cluster. Convex portions corresponding to the minimum halftone dots in the halftone image are formed on the printing plate. A convex portion corresponding to the main cluster is supported by convex portions corresponding to the sub-clusters to increase the strength of relief corresponding to the minimum halftone dot. Reliefs corresponding to the minimum halftone dots are normally formed regardless of a dot area rate of highlight area to thereby improve reproduction in printing of the halftone image.

Halftone image generation method, threshold matrix generation method, threshold matrix, printing plate manufacturing method, and printing plate

An image recording apparatus according to this invention includes a frequency dividerfor generating a reference signal of a frequency higher than that of a dot clock signal, a pulse exposure control circuitfor causing a laser beam emitted from a laser diodeto irradiate a recording medium when both an image signal and the reference signal are ON, and a switching devicefor switching between a first recording mode for causing the laser beam emitted from the laser diodeto irradiate the recording medium when the image signal is ON, and a second recording mode for causing the laser beam emitted from the laser diodeto irradiate the recording medium when both the image signal and reference signal are ON.

Image recording apparatus having a laser source

An image recording apparatus () causes a recording head () to move through a distance corresponding to one half of the recording width of the recording head () in a sub-scanning direction each time a recording drum () makes one rotation. This, light emitting devices () record two line data in advance, and thereafter following light emitting devices () record the same line data repeatedly at the same position. This increases the energy of laser light beams given to a recording position on a printing plate (P) to accomplish the recording of an image with reliability. The recording speed is not extremely decreased because not all light emitting devices (to) are used to make the repeated recordings at the same position on the printing plate (P). Further, the construction of optical systems and driving systems in the image recording apparatus is not complicated.

Apparatus for and method of recording image

Growing community of inventors

Kyoto, Japan

Yuji Kurokawa