Canon Kabushiki Kaisha

Katsuhiro Ishido

Takashi Soya

Daisuke Akagi

Toshio Hayashi

Tetsuro Fukusaka

Hirotaka Seki

Noriaki Matsui

Kazunori Togashi

Yuichi Makino

Shinichiro Wakahara

Nobuo Matsuoka

Masafumi Kamei

Tsunao Honbo

Toshitaka Noro

Jiro Futagawa

Satoru Kijima

Takeshi Aoyama

Daisuke Morikawa

Noriyoshi Chizawa

Yuzuru Yano

Shohei Takeda

Hayato Koyama

Shouhei Takeda

Akihiro Kashiwabara

Junichi Kishimoto

An original image is read as an aggregate of a plurality of pixels in which adjacent pixels have different colors (R, G, and B) in a main scanning direction and in a sub-scanning direction, and the read pixels of the respective colors are stored in a line memory in association with information on relative positions of the pixels with respect to another pixel. Then, the stored pixels are sorted so that pixels having the same color are adjacent to each other, and an abnormal pixel (dust) not present in the original image is detected based on the state of the sorted pixels. With this, the dust not present in the original image is detected without increasing the cost, and the dust is corrected without forming a conspicuous trace of correction.

Image reading apparatus with detection of abnormal pixels

An optical sensor includes a first light emitting diode (LED), a second LED, a first photodiode (PD), and a second PD. The first LED and the second LED are configured to irradiate an optical-axis center point of an intermediate transfer belt. The first PD is arranged at a position at which specularly reflected light of light emitted from the first LED and diffused reflected light of light emitted from the second LED are received. The second PD is arranged at a position at which diffused reflected light of the light emitted from the first LED is received.

Optical sensor and image forming apparatus

An image reading apparatus includes a front-side reader, which includes a white LED configured to irradiate an original with light and a CMOS sensor configured to receive light that is reflected by the original. The front-side reader is configured to generate read data that represents a luminance value of an image on the original from the result of receiving light with the CMOS sensor. The image reading apparatus stores, in a non-volatile memory, a condition for determining whether there is a sub-scanning color shift, and uses a sub-scanning color shift detector to determine whether there is a sub-scanning color shift based on the read data obtained from the front-side reader and the condition stored in the non-volatile memory. When there is a sub-scanning color shift, the image reading apparatus corrects the sub-scanning color shift by correcting the read data with a color shift corrector.

Image reading apparatus with correction for sub-scanning color shifts, image forming apparatus, image reading method, and computer readable non-transitory storage medium

Image reading apparatus

Provided is an image reading apparatus capable of accurately detecting an inclination amount of an original image by recognizing an edge part of the original image with high precision even when dust, stain, or the like adheres to a background part. The image reading apparatus includes: an original reader configured to read an image of an original; and a volume resistor configured to represent an original width of the original by a resistance value. The image reading apparatus further includes: a skew feed amount detector configured to set a predetermined range including the edge part of the original in a width direction as an edge detection range based on the original width, to acquire an edge image being the edge part of the original from an image within the edge detection range.

Image reading apparatus with skew feed correction and image reading method thereof

Provided is an image reading apparatus configured to recognize edge portions of an image of an original precisely without being influenced by the varying state of the four sides of the original. The image reading apparatus includes an image reading unit configured to read the original image by scanning the original, an edge determining unit configured to determine first edge locations at the left end and right end of the original image in a main scanning direction, an edge detector configured to detect a second edge location of the original image in a sub-scanning direction, a tilt expression calculator configured to calculate a linear expression that represents the amount of inclination of the original image with respect to the main scanning direction.

Image reading apparatus and image reading method

An image reading apparatus which is capable of successfully reading an image off an original by correctly detecting a size of the original without degrading productivity even if mixed-size originals are placed on an original tray with edges not aligned. An image reading unit reads an image off an original passing through a reading position. An original size detection sensor detects an original. A first original size is determined using a result of detection by the original size detection sensor, and a second original size is determined using the image read off the original. The first original size or the second original size is adopted as an original size.

Image reading apparatus with original size detection sensor

In the original reading apparatus configured to store the image data in the image storing unit such as temporary storage memory, time required to complete the overwriting for erasure is reduced. The image data read by the image reading unit is stored in the image data storing unit and the stored image data is output. To hold data stored in the image data storing unit, refresh processing, which is to perform processing intermittently required to hold the data stored in the image data storing unit, is performed at a predetermined execution frequency. After the image data is output, frequency to execute the refresh processing is reduced as compared to a predetermined execution frequency to perform writing of the dummy data.

Information processing apparatus and original reading apparatus

A document size detector sets an amount of light to be emitted from a light source for document size detection in accordance with the amount of disturbance light detected by the CCD, switches on the light source so as to make the light source emit the set amount of light, and detects the size of a document placed on a platen. Therefore, erroneous detection of a document size is prevented and glare that a user is subjected to when the size of a document placed on the platen is detected is reduced.

Document size detector

A plurality of line sensors corresponding to a plualrity of color components receive reflected light passed through an imaging unit and convert the light into a plurality of color component data. A correcting unit performs color misalignment correction based on a reference color component for which resolution performance is lowest among the plurality of color component, on the color component data corresponding to other color components.

Original reading apparatus reading image from original

A document reading apparatus includes a white LED including an LED and a fluorescent material and configured to illuminate a document reading position with light, a reading unit having a color line sensor and a monochrome line sensor and configured to read an image of a document illuminated with the light emitted from the white LED, and a filter arranged on an optical path between the monochrome line sensor and the document, and wherein the filter is configured to suppress transmission of light at a peak wavelength of the LED so that, regarding an intensity of light to be received on the monochrome line sensor, the intensity of the light at the peak wavelength of the LED is smaller than the intensity of the light at the peak wavelength of the fluorescent material when the light emitted from the LED is received.

Document reading apparatus

A document reading apparatus includes a document positioning plate configured to set a document to be read thereon, a light source configured to emit light onto an area where the document is set on the document positioning plate, an image sensor configured to photoelectrically convert reflected light of the light emitted from the light source to output color signals, and a document size detection unit configured to select a color signal used for document size detection from among the color signals output from the image sensor based on the color signals output from the image sensor in a state where the light source is turned off, and to detect a size of the document set on the document positioning plate based on the selected color signal output from the image sensor in a state where the light source is turned on.

An original size detecting apparatus is capable of carrying out accurate original size detection without erroneous detection of the size of an original due to the influence of external scattered light. A CCD reads reflected light of light irradiated from a light source onto an original placed on an original platen glass. Optical sensors detect two open states of the original presser plate, and a scanner controller performs predetermined control corresponding to each of the open states of the original presser plate detected by the optical sensors, to determine the size of the original based on the result of the reading by the CCD.

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Abiko, Japan

Katsuhiro Ishido