Ricoh Company, Ltd.

Masahito Obata

Tomio Sasaki

Shinji Kobayashi

Hidefumi Nishitsuji

Takanobu Saito

Makoto Ide

Morihiko Okimoto

An image forming apparatus, method and computer program product, including a pattern detecting device configured detect whether or not a pattern is constructed with a lengthwise line of a single dot width on a basis of a pattern of respective multi-value data of a target pixel and circumferential pixels adjacent thereto in a main scanning direction; and a printing device configured to print size-reduced printing dots of the lengthwise line of the single dot width detected by the pattern detecting device.

Apparatus, method and computer program product for performing image formation

An image forming system includes an imaging data generator which generates a dot intensity data from each of a series of pixels contained in an input image, each pixel having bits indicative of an intensity of the pixel only, the imaging data generator including a plurality of discrimination patterns to detect the presence of a 1-pixel-thick vertical line or a multipixel-thick line edge in the input image. An optical writing unit modulates an emission power and/or an emission time of a laser diode by using the dot intensity data, and determines the emission power of the laser beam per dot based on the dot intensity data, so that the laser diode emits the laser beam to a photoconductive medium in accordance with the modulation data. When an intensity pattern related to a subject pixel and neighboring pixels thereof matches one of the discrimination patterns, the imaging data generator selects a corrected intensity value corresponding to the matched discrimination pattern as the dot intensity data. When the intensity pattern does not match any of the discrimination patterns, the imaging data generator selects the intensity of the subject pixel as the dot intensity data.

Image forming system having an improved imaging data generator

A writing devices for an image forming apparatus of the present invention determines whether or not an image at and around an interval between nearby light emitter chips of a light emitter array is of halftone. If the image is of halftone, the writing device corrects image data corresponding to the above interval in order to increase the quantity of light. This successfully reduces or fully obviates the local omission of an image ascribable to intervals between nearby light emitter chips and insures a smooth output image.

Writing device for an image forming apparatus

In a digital copier of the type writing image data read by a scanner in a memory and transferring them from the memory to a printer, a memory change flag indicative of whether or not to calculate the occupancy of the memory is checked. If the flag is set, the occupancy of the memory is calculated and sent to a system controller. One or more reference amounts, which are easy for the user to grasp (e.g. amount corresponding to a single paper of A4 size), can be entered on an operation and display panel. The occupancy of the memory is displayed on the operation and display panel on the basis of each of the reference amounts. The memory change flag is set when image data have been fully written to the memory and when the discharge of a recording medium carrying an image thereon from the copier has been detected (end of read-out). The copier prevents the image data stored in the memory from being destroyed.

Digital copier with memory occupancy calculation

A digital image forming apparatus having a scanner for reading a document, a memory for storing image data generated by the scanner, and a printer for outputing the image data read out of the memory. Only the image data representative of the actual document are written to the memory so as to use the memory efficiently.

Digital image forming apparatus

An image area dicriminating device for a digital copier, facsimile machine, scanner or similar imaging equipment. The device determines whether areas constituting an input image each has undergone dot processing or not automatically.

Image area discriminating device

An image processing apparatus includes an edge detector for detecting whether or not a target pixel of an input image signal is at an edge portion of a discontinuous density image; a first quantizer for generating quantized image data with respect to the target pixel by using a first error spreading filter having a relatively high error spreading effect, such that a density error between the input image signal and an output multilevel image signal is incorporated in 'm' neighboring pixels surrounding the target pixel; a second quantizer for generating quantized image data with respect to the target pixel by using a second error spreading filter having a relatively low error spreading effect, such that a density error between the input image signal and the output multilevel image signal is incorporated in 'm' neighboring pixels surrounding the target pixel; and a selector for selecting either the quantized image data generated by the first quantizer or the quantized image data generated by the second quantizer in accordance with the result of a detection made by the edge detector.

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Tokyo, Japan

Masahito Obata