Abstract: If a determination result obtained using software in a scanner CPU is not identical to a determination result obtained using hardware in a determination section, error processing is performed to prevent image forming of a particular document.

Abstract: An image copier according to the invention comprises a scanner for reading an image and a printer for forming an image on sheet, and the scanner includes a document table for positioning an original document from which an image is to be read; a document holding cover holding the original document on the original document table and having a light-emitting element for detecting the size of an original document which emits light when the size of the original document is detected, a light source for irradiating the original document with light when an image on the original document is read, a light-receiving element for image reading which receives reflected light from the original document, a controller for the light-emitting element for detecting the size of an original document which controls the light-emitting element for detecting the thickness of the original document, a specific region determination unit for identifying a specific region based on the numbers of pixels in a main scanning direction and a sub

Abstract: An image copier of the invention includes a document table to position a document from which an image is read, a document holding cover to hold the document on the document table, a light source to irradiate light to the document when the image of the document is read, and an image reading light receiving element to receive reflected light from the document, and the document holding cover includes a document size detecting light emitting element to emit light at a time of document size detection. According to the image copier of the invention, the document size can be accurately detected independently of the kind of the document.

Abstract: The CPU of the image forming apparatus sets up an ADF reading magnification in the ADF driving unit including the motor and the motor driver referring to the first magnification conversion table in the memory of the system unit when reading a document image while a document is being moved. Further, the reading magnification that is also in the ADF driving unit is also set in the specific document detection unit. The specific document detection unit makes the pattern matching as to whether the read image data is that of a specific document using the magnification dictionary (specific image data) that is set and outputs a detection signal as the result of the matching to the CPU. As that time, the CPU controls the output of the applicable read image data by a printer according to the detection signal.

Abstract: A light beam position detecting device detects the passage positions of a plurality of light beams for scanning the surface of a photosensitive drum. The light beam position detecting device has a sensor pattern for generating an output which is continuously changed in a wide range with a variation in the passage position of the light beam in a sub-scanning direction perpendicular to a main scanning direction of the light beam. The sensor pattern precisely detects the relative scanning position of the light beam in a wide range. The passage positions of the plurality of light beams for scanning the surface of the photosensitive drum are controlled to a preset position based on the output of the sensor pattern.

Abstract: A light beam position detecting device detects the passage positions of a plurality of light beams for scanning the surface of a photosensitive drum. The light beam position detecting device has a sensor pattern for generating an output which is continuously changed in a wide range with a variation in the passage position of the light beam in a sub-scanning direction perpendicular to a main scanning direction of the light beam. The sensor pattern precisely detects the relative scanning position of the light beam in a wide range. The passage positions of the plurality of light beams for scanning the surface of the photosensitive drum are controlled to a preset position based on the output of the sensor pattern.

Abstract: A light beam position detecting device detects the passage positions of a plurality of light beams for scanning the surface of a photosensitive drum. The light beam position detecting device has a sensor pattern for generating an output which is continuously changed in a wide range with a variation in the passage position of the light beam in a sub-scanning direction perpendicular to a main scanning direction of the light beam. The sensor pattern precisely detects the relative scanning position of the light beam in a wide range. The passage positions of the plurality of light beams for scanning the surface of the photosensitive drum are controlled to a preset position based on the output of the sensor pattern.

Abstract: With the present invention, by changing the scanning timing of a CCD line sensor in accordance with the amount of scanning misregistration corresponding to a magnification, misregistration of less than one line can be accurately corrected, thereby eliminating degradation of MTF, which has occurred in conventional apparatuses.

Abstract: An image reading device includes a light irradiation device that moves and scans a document while irradiating the light on the document table, a color CCD sensor which reads the reflecting light of the light from the light irradiating device and photoelectric converts it into plural color signals, and a correction device which executes the shading correction of plural color signals that are photoelectric converted by the color CCD sensor and at the same time, executes the color balance correction and the stray light correction. Further, at the same time with the shading correction executed using white document data comprising R, G, B signals of a white document in color equipment to the shading correction plate that are read and photoelectric converted by the color CCD sensor as desired values for the shading correction, this image reading device executes the color balance correction and the stray light correction.

Abstract: The CPU of the image forming apparatus sets up an ADF reading magnification in the ADF driving unit including the motor and the motor driver referring to the first magnification conversion table in the memory of the system unit when reading a document image while a document is being moved. Further, the reading magnification that is also in the ADF driving unit is also set in the specific document detection unit. The specific document detection unit makes the pattern matching as to whether the read image data is that of a specific document using the magnification dictionary (specific image data) that is set and outputs a detection signal as the result of the matching to the CPU. As that time, the CPU controls the output of the applicable read image data by a printer according to the detection signal.

Abstract: A light beam position detecting device detects the passage positions of a plurality of light beams for scanning the surface of a photosensitive drum. The light beam position detecting device has a sensor pattern for generating an output which is continuously changed in a wide range with a variation in the passage position of the light beam in a sub-scanning direction perpendicular to a main scanning direction of the light beam. The sensor pattern precisely detects the relative scanning position of the light beam in a wide range. The passage positions of the plurality of light beams for scanning the surface of the photosensitive drum are controlled to a preset position based on the output of the sensor pattern.

Abstract: A light beam position detecting device detects the passage positions of a plurality of light beams for scanning the surface of a photosensitive drum. The light beam position detecting device has a sensor pattern for generating an output which is continuously changed in a wide range with a variation in the passage position of the light beam in a sub-scanning direction perpendicular to a main scanning direction of the light beam. The sensor pattern precisely detects the relative scanning position of the light beam in a wide range. The passage positions of the plurality of light beams for scanning the surface of the photosensitive drum are controlled to a preset position based on the output of the sensor pattern.

Abstract: In a digital copying machine using a multi-beam optical system, a sensor pattern senses a light beam directed onto the photosensitive drum and generates current according to the amount of light. The current is converted into a voltage by an operational amplifier acting as a current/voltage conversion amplifier. The output voltage of the operational amplifier is integrated by an integrator. The output of the integrator is converted into a digital signal by an A/D converter, thereby producing luminous energy sensing information. According to the luminous energy sensing information, a laser oscillator is controlled. Between the operational amplifier and integrator, a variable resistor is inserted which absorbs variations in the sensitivity of the sensor pattern or variations in the conversion characteristic of the operational amplifier.

Abstract: In an image reading apparatus according to the invention, the switching frequency of a switching power supply is set to a value equal to integral multiples of a reading frequency corresponding to each line, thereby correcting, for example, uneven image density due to ripples in a power supply voltage. Further, the switching of the switching power supply is synchronized with a horizontal synchronizing signal output from a scanner, thereby causing the positions of the ripples to correspond between lines for correcting, for example, uneven image density.

Abstract: An image reading apparatus according to the present invention can obtain an image light from all areas of a document with uniform brightness, when receiving an image light from an area elongate in a first direction, and obtaining image data corresponding to the image information of a document by moving the image light area in a direction orthogonal to the first direction.

Abstract: If a determination result obtained using software in a scanner CPU is not identical to a determination result obtained using hardware in a determination section, error processing is performed to prevent image forming of a particular document.

Abstract: An image reading apparatus having a color line sensor and a monochromatic line sensor starts to read on the basis of the color reading start position when reading the image of a document in color and starts to read on the basis of the monochromatic reading start position when reading the image of a document in monochrome.

Abstract: An image reading unit according to the present invention includes a lamp to incorporate a change in temperature conditions to the emitting light amount, the lamp capable of illuminating an reading object with a light of a predetermined intensity, an image signal generation unit which generates an image signal corresponding to the reflected light generated when a reading object is illuminated, and a cooling unit which cools a predetermined range of the lamp, so that the intensity change in the light radiated from the lamp of the illumination unit, in the length direction of the illumination unit can be suppressed.

Abstract: With the present invention, by changing the scanning timing of a CCD line sensor in accordance with the amount of scanning misregistration corresponding to a magnification, misregistration of less than one line can be accurately corrected, thereby eliminating degradation of MTF, which has occurred in conventional apparatuses.

Abstract: The emission level of a laser source at the non-imaging time when image data “0” is input and the emission level at the imaging time when image data “1” is input are controlled so that each of them becomes a desired level. The light output intensity is stabilized at all times regardless of variations in ambient temperature. As a result, images uniform in density can be obtained.