A document platen on which a document is placed; and a reading sensor having a light source for irradiating the document with light, are provided, and the reading sensor performs first scanning for irradiating the document with light at a first light quantity, and then performs second scanning for irradiating the document with light at a second light quantity greater than the first light quantity.

A reading device includes a carriage configured to move in a sub-scanning direction with reference to an object placed on a contact glass, an optical sensor attached to the carriage, the optical sensor being configured to scan the object placed on the contact glass to obtain an image of the object, and a reference scale used as a reference when a dimension of the object is computed based on the image obtained by the optical sensor. In the reading device, the reference scale extends in a main scanning direction and a sub-scanning direction with reference to the object, and is disposed outside a range of image acquisition in which the optical sensor scans the object to obtain the image of the object as the carriage moves and inside a maximum movement range in which the carriage is movable and the optical sensor obtains the image of the object.

An image forming apparatus includes a light transmitting member provided at a reading position set in a conveyance path and an opposite plate opposed thereto, and a document being conveyed passes between this opposite plate and the light transmitting member. On an opposing surface of the opposite plate to the light transmitting member, a low brightness area, for example, like a gray color and a high brightness area, for example, like a white color, having a higher brightness than the low brightness area are formed adjacent to each other in a conveyance direction of the document. Then, an image reader sets a home position of a scanning unit to a first position or a second position corresponding to either the low brightness area or the high brightness area to read the document passing through the reading position.

The present invention discloses a double-sided synchronous scanning device. A scanning channel is formed between two scanning components; two backlight plates are respectively used to provide backlight for an opposite-side scanning component and fixed with the same-side scanning component; one side of each backlight plate facing the scanning channel is provided with a light guide groove corresponding to a light inlet of the corresponding scanning component; a backlight source is arranged in the light guide groove. When the two scanning components work synchronously, because the backlight plates always need to provide backlight for the opposite-side scanning component, and the reflected light generated by the backlight plates on a scanned sample enters the light inlet of the same-side scanning component, which will affect the image scanning effect.

An image reading apparatus includes a moving unit, a first detecting unit, and a second detecting unit. The moving unit moves a calibration plate in the main scanning direction relatively to a reading apparatus. The calibration plate is a plate for calibrating the reading apparatus. The reading apparatus has a reading unit and reading glass. The reading unit is arranged in the main scanning direction. The reading glass is disposed on a reading surface side of the reading unit. The first detecting unit detects an abnormality on the calibration plate from reading results. The reading results are obtained in such a manner that, while the moving unit is controlled to move the calibration plate, the reading unit reads the calibration plate. The second detecting unit detects an abnormality on the reading glass from the reading results.

According to one embodiment, an image reading apparatus includes a light emitting unit, a first carriage, a first photoelectric conversion unit, a first lens, and a second carriage. The light emitting unit irradiates a reading object with light. The first carriage includes a first optical member for guiding reflected light from the reading object. The first carriage is movable in a sub-scanning direction along the reading object. The first photoelectric conversion unit receives the reflected light from the reading object guided through the first optical member and outputs an image signal. The first lens is disposed on an optical path of the reflected light between the first optical member and the first photoelectric conversion unit, and images the reflected light from the reading object on the first photoelectric conversion unit. The second carriage is movable in a main scanning direction orthogonal to the sub-scanning direction along the reading object with respect to the first carriage. The second carriage includes a second optical member for guiding the reflected light from the reading object, a second photoelectric conversion unit that receives the reflected light from the reading object guided through the second optical member to output an image signal, and a second lens that is disposed on an optical path of the reflected light between the second optical member and the second photoelectric conversion unit and images the reflected light from the reading object on the second photoelectric conversion unit at a magnification different from the first lens.

An image reading apparatus includes an LED light source, a CCD sensor receiving light reflected from a document irradiated with light from the LED light source, a fan, and a frame housing the LED light source, the CCD sensor and the fan. The fan circulates air in a substantially sealed space formed by the frame. Thus, temperature difference in the image reading apparatus can be reduced while not degrading dust-proof property of the apparatus, and efficient heat radiation to the outside becomes possible. Thus, variation of sensitivity of CCD sensor, deviation of point of focus of image forming system and deviation of reading position caused by temperature increase can be prevented.

An image reading device includes a single light source that irradiates an image reading target with light, a traveling change member that changes a traveling direction of the light from the light source and irradiates the image reading target with the light at an incidence angle different from an incidence angle of the light directly applied from the light source to the image reading target, and a switching mechanism that switches traveling of the light from the light source to an optical path for directly irradiating the image reading target or an optical path for irradiating the image reading target via the traveling change member.

An image reading device includes plural light sources that irradiate an image reading target with light at different angles; and a switching mechanism that sequentially switches the light incident to the image reading target from the plural light sources during an image reading operation on the image reading target.

An image processing device includes a light source, a reader, and circuitry. The light source is configured to irradiate an object at least with invisible light. The reader is configured to read a first image from the object irradiated with the invisible light. The circuitry is configured to generate a second image from the first image read by the reader. The circuitry is configured to recognize first information in the second image.