By overlapping lighting timings of light sources that emit lights of a plurality of different wavelength bands including a wavelength band of at least a visible light region and an infrared light region, the lights of the plurality of the different wavelength bands including the wavelength band of at least the visible light region and the infrared light region are emitted on a banknote while securing an overlap in timings thereof. Moreover, by using light receiving elements each including a bandpass filter that allows only light of a wavelength range that corresponds to the wavelength band of each of the light sources, received light intensities of the light of the wavelength range that corresponds to the wavelength band of each of the light sources are acquired simultaneously, and image data are formed based on the received light intensity of every acquired wavelength band.

Provided is an image reading optical system including an image reading unit in which plural reading devices are arranged in a first direction, and plural image-forming mirrors that guide reflected light, which is acquired by reflecting light from a light source in a reading target, to the image reading unit, wherein any one of the plural image-forming mirrors is an adjustment mirror that has power only in one of the first direction and a second direction intersecting the first direction, and is rotatable or relatively movable with respect to the other image-forming mirrors.

A reading apparatus that reads a sheet includes: a first light emitting diode (LED) configured to emit light with a specific wavelength; a light emitting element including a second LED configured to emit light with the specific wavelength and a phosphor configured to be excited by the light emitted from the second LED; a line sensor configured to generate a reference signal according to a quantity of received light emitted from the first LED and reflected off the sheet, and also generate an image signal according to a quantity of received light emitted from the light emitting element and reflected off the sheet; and a controller configured to generate an image representing the sheet from a differential result obtained by removing a component corresponding to the reference signal from the image signal.

An image reading apparatus includes: three or more light sources configured to each emit light; a light receiving unit including a common light receiving surface configured to detect each light emitted; and an image generation unit configured to cause the three or more light sources to be switched over in a predetermined order and emit the corresponding light, and generate an image read from a document, wherein at least one of the three or more light sources includes a white light source and an optical filter, and the optical filter is configured such that a half-value width of a wavelength with respect to a maximum intensity of a spectral characteristic of the emitted light after transmission is wider than a half-value width of a wavelength with respect to a maximum intensity of the spectral characteristic of the light emitted from at least one of the other light sources.

A light irradiation device includes a light source, a light guide member, and a holding member. The light guide member includes an incident surface, an exit surface, and a held surface. The incident surface has an elongated shape in a main scanning direction and faces a light emitting surface of the light source. The light guide member includes a securing structure in each of both end portions in the main scanning direction, which are out of a light guide area of the light guide member. The securing structure in one end portion is an engagement lug structure protruding to penetrate into a through-hole of the holding member, including a lug on a leading end, and engaging the holding member. The securing structure on another end portion is a fastening structure having a fastening hole penetrated with a fastening member and being secured to the holding member with the fastening member.

A reading apparatus includes: a light-shielding member having a thickness T in which plural through-holes having a diameter D through which light reflected from a document passes are formed at an interval P; an optical member that includes a surface separated from and facing the light-shielding member and including lenses formed at positions facing the through-holes, in which a light-shielding film is formed on at least the surface other than a lens surface of the lens, and a distance L from the light-shielding member in an optical axis direction of the lens satisfies 0<L≤T (P/D−1); and a substrate that includes an element that receives light passing through the optical member.

In a reading device part, a scan motor that moves a sensor unit relative to a document is accommodated in an accommodating portion protruding from the bottom surface of the reading device part toward a printing device part. A carriage in the printing device part and the accommodating portion are arranged so as to face each other in a direction crossing the scan direction of the carriage at the same height in the vertical direction. A flexible member connected to the carriage moves and follows the carriage on a lower side relative to the accommodating portion.

A reflective member is disposed on the optical path from the linear light source to the lens array. An ultraviolet light blocking filter is provided closer to a light-receiving unit than the reflective member. A color filter is provided closer to the light-receiving unit than the ultraviolet light blocking filter. A light-receiving surface of the light-receiving unit has a first region opposed to the reflective member without the ultraviolet light blocking filter and the color filter interposed therebetween, a second region opposed to the reflective member and the ultraviolet light blocking filter without the color filter interposed therebetween, and a third region opposed to the reflective member, the ultraviolet light blocking filter, and the color filter.

In a line sensor including color filters that are periodically disposed in a light-receiving-element row, a problem called a “mixture of colors” occurs. A “mixture of colors” occurs when light that has been transmitted through a color filter differing from a color filter corresponding to a light receiving element is incident upon the light receiving element. In a CMOS sensor 107 including a light-receiving-element row in which a plurality of photodiodes 1204 are disposed side by side in a main scanning direction and a plurality of color filters 1202 that are disposed in correspondence with the plurality of photodiodes 1204, the center of each color filter 1202 is displaced in a direction of the center of the light-receiving-element row from the center of the photodiode 1204 corresponding to the color filter.

Systems and methods relate generally to exposure correction of an image transparency. In an example method thereof, an adaptable filter having an adjustable transparency panel and a microcontroller is obtained. The image transparency is backlit to obtain first analog image information by the adaptable filter. An exposure level associated with the first analog image information is sensed. A transparency level of the adjustable transparency panel is adjusted responsive to the sensed exposure level. Second analog image information is obtained from the adjustable transparency panel provided to a sensor array. The second analog image information is the first analog image information with the adjusted transparency level.