An apparatus includes a second detection unit configured to detect whether there is a decrease in reflectance of a reflection unit for light, based on a second output value which is output by an output unit based on light which is received by a light receiving unit in a state in which, after a first output value is controlled to become a prescribed value, a light emitting unit is radiating light and it is detected by a first detection unit that a predetermined object is present in a path.

An optical information reader includes a reflective member that reflects illumination light emitted from an illuminant toward a reading surface, and an image former ensured to present an imaging target held over the reading surface within an imaging region of an imager. The imaging region includes a first imaging region defined between the image former and the reading surface, and a second imaging region defined between the reading surface and the reflective member so as to be continuous to the first imaging region when light is internally reflected on the reading surface inside the housing. The reflective member is arranged outside the first imaging region, while the illuminant, the imager and the image former are arranged outside the second imaging region. The illuminant emits illumination light toward a reflecting surface of the reflective member in the second imaging region.

Example implementations relate to an edge sensing apparatus. For example, an edge sensing apparatus consistent to the present disclosure may include a reflector in a beam path of a retroreflective sensor. The edge sensing apparatus consistent with the present disclosure may include a cover glass located between the retroreflective sensor and the reflector. The edge sensing apparatus consistent with the present disclosure may include a media feeder to feed a media along a media path between the cover glass and the retroreflective sensor.

An optical device includes a light emitting surface, a lens mirror array having an incident surface that transmits light from the light emitting surface and converges the light, an emission surface that emits the light incident through the incident surface, and a plurality of reflecting surfaces that reflect the light incident through the incident surface toward the emission surface, and an image plane where an image of the light emitted through the emission surface is formed. The light emitting surface and the image plane are disposed nonparallel to each other so that an imaginary first plane parallel to the light emitting surface and an imaginary second plane parallel to the image plane intersect at a side of the plurality of reflecting surfaces.

A light sensing apparatus includes a sheet passage, a first sensing assembly and a first background sheet. The sheet passage has a scan window. The first sensing assembly disposed on a first side of the scan window outputs first scan light to the scan window. The first background sheet disposed on a second side of the scan window has a first reflective surface reflecting the first scan light, passing through the scan window, back to the first sensing assembly through the scan window. The first reflective surface of the first background sheet and the scan window are disposed in a non-parallel manner. Therefore, a light sensing method is also provided to achieve the effects of brightness calibration and boundary detection of the first sensing assembly.

An image data generating method of generating an image from a document includes acquiring, based on light reflected by the document, a first image signal corresponding to a plurality of components in a plurality of visible wavelength ranges and a component having a reflection absorption characteristic in an invisible wavelength range, converting the first image signal into a second image signal including a plurality of device-independent color space components and a black component, and generating image data based on the second image signal.

A reading device includes a radiator configured to radiate light, a light receiver configured to receive the light reflected from an image capturing target, a first optical path on which the light radiated by the radiator is reflected by a reflection surface to irradiate a surface of the image capturing target in a radiation area so that diffuse reflection light diffusely reflected by the surface of the image capturing target is guided to the light receiver as a read image, a second optical path on which the light radiated by the radiator is reflected by the reflection surface to irradiate the surface of the image capturing target in the radiation area so that regular reflection light regularly reflected by the surface of the image capturing target is guided to the light receiver as a read image, and a switcher configured to switch the first optical path and the second optical path in a carriage that houses the radiator and the reflection surface and moves along a sub-scanning direction for image reading.

An illuminating device according to an embodiment included in an image reading apparatus and an image forming apparatus includes light source portions, light-guiding members for illuminating an illumination target from an elongated light emitting face that extends in a longitudinal direction, by guiding light from the light source portions, and holding members for holding the light-guiding members. The holding members include holding portions for removably holding the light-guiding members, and tilted portions that reflect light emitted from the light emitting face, the tilted portions extending from a front end on the light emitting face side of the holding portions, obliquely widening with increasing distance from the light-guiding members.

An image reading apparatus includes a light source that emits light in a main scanning direction to a subject to be read, a light receiving unit that receives light reflected by the subject to be read, and an optical system that images the light reflected by the subject to be read and guides the light to the light receiving unit. The optical system includes a reflector mirror that reflects the light reflected by the subject to be read, and an optical element that is disposed adjacent to the reflector mirror and images the light reflected by the subject to be read. The optical element is held by the reflector mirror.

An illuminating device according to an embodiment included in an image reading apparatus and an image forming apparatus includes light source portions, light-guiding members for illuminating an illumination target from an elongated light emitting face that extends in a longitudinal direction, by guiding light from the light source portions, and holding members for holding the light-guiding members. The holding members include holding portions for removably holding the light-guiding members, and tilted portions that reflect light emitted from the light emitting face, the tilted portions extending from a front end on the light emitting face side of the holding portions, obliquely widening with increasing distance from the light-guiding members.