An image reading device can easily increase or improve the depth of field. The image reading device includes a lens array (1) including lenses (2) arrayed in a main scanning direction, a sensor array (4) including sensor elements (4) arrayed in the main scanning direction to receive light converged by the lenses (2), and an overlap preventer located between the lens array (1) and the sensor array (4) to prevent an overlap of images formed by the lenses (2). The overlap preventer includes a slit assembly (5) including at least one specific-light blocker or optically transparent columns (13).

An image forming system (100) includes an image forming apparatus (1) and an image reading apparatus (50). The image forming apparatus (1) include a first casing (10) including a top plate (13) having a first opening (11) and a second opening (12); and a fixing member (20) disposed below the top plate (13), having a first projecting part (21) and a second projecting part (22) and operated such that the first projecting part (21) is protruded and retracted through the first opening (11) and the second projecting part (22) is protruded and retracted through the second opening (12). The image reading apparatus (50) includes: a second casing (60) placed on the first casing (10); a second carriage (52) being movable inside the second casing (60); a lock member (70) which is engaged with the second carriage (52) to restrict movement of the second carriage (52), and when pushed up by the first projecting part (21), is disengaged from the second carriage (52) to release restriction of the movement of the second carriage (52); and a third opening (64) into which the second projecting part (22).

An image reading apparatus includes a for-still-document contact glass serving as a reading face for a placed document, a for-moving-document contact glass serving as a reading face for a document conveyed by an automatic document feeder, and an optical scanner unit to move in a scanning range of the for-still-document contact glass back and forth in a sub-scanning direction to scan the document. The optical scanner unit moves to a scanning range of the for-moving-document contact glass and scans the document in a static manner when the document is conveyed in an automatic manner, and the optical scanner unit includes a contact image sensor, a carriage that holds the contact image sensor in a movable manner in the sub-scanning direction, and a pair of end sliders arranged on both ends of a plane facing the reading face in a longer-side direction of the optical scanner unit.

An image reading apparatus includes a for-still-document contact glass serving as a reading face for a placed document, a for-moving-document contact glass serving as a reading face for a document conveyed by an automatic document feeder, and an optical scanner unit to move in a scanning range of the for-still-document contact glass back and forth in a sub-scanning direction to scan the document. The optical scanner unit moves to a scanning range of the for-moving-document contact glass and scans the document in a static manner when the document is conveyed in an automatic manner, and the optical scanner unit includes a contact image sensor, a carriage that holds the contact image sensor in a movable manner in the sub-scanning direction, and a pair of end sliders arranged on both ends of a plane facing the reading face in a longer-side direction of the optical scanner unit.

A contact image sensor includes a preset scanning plane used for the surface to be scanned to map to the original copy. The contact image sensor includes: a timing circuit: for self-generating light source control signal LRDT and line scan control signal TRIG1; a lens: for collecting reflected light emitted by a light source reflected by the original copy and emitting the reflected light onto a photoelectric conversion chip for converting received optical signals into electrical signals; and a data processing unit: emitting trigger pulse TRIG according to the encoder transmitting the object to be detected, receiving and processing electrical signals output by the photoelectric conversion chip that has the same size of the photoelectric signal output, ensuring the output stability, dynamic range and sensitivity of the image sensor.

A contact image sensor includes a preset scanning plane used for the surface to be scanned to map to the original copy. The contact image sensor includes: a timing circuit: for self-generating light source control signal LRDT and line scan control signal TRIG1; a lens: for collecting reflected light emitted by a light source reflected by the original copy and emitting the reflected light onto a photoelectric conversion chip for converting received optical signals into electrical signals; and a data processing unit: emitting trigger pulse TRIG according to the encoder transmitting the object to be detected, receiving and processing electrical signals output by the photoelectric conversion chip that has the same size of the photoelectric signal output, ensuring the output stability, dynamic range and sensitivity of the image sensor.

An image reading device (1) includes a board (24) including a plurality of imaging elements (23) arranged along a scanning direction, and a housing (13) including (i) a plurality of optical components that are arranged along the scanning direction and (ii) a plurality of housing components (13a, 13b) that are arranged along the scanning direction. Each of the plurality of optical components focuses light reflected by a reading target onto a corresponding imaging element (23), and each of the plurality of housing components holds at least one optical component. The plurality of housing components (13a, 13b) are arranged to have a clearance therebetween and each of the plurality of housing components (13a, 13b) is fixed to the board (24) at a position to transmit light through the optical components to focus onto the corresponding imaging element (23).

An optical head comprises a substrate on which optical elements are arranged in a main scanning direction, a lens unit that transmits light emitted from the optical elements or light entering the optical elements, and a holder that holds the lens unit. The holder has a sidewall extending in the main scanning direction. The sidewall has a hole at a position facing the lens unit. A fixing member is provided in the hole. The fixing member fixes the lens unit to the sidewall.

An image reading apparatus comprises a first reading unit configured to output an analog signal by reading an original, a second reading unit different from the first reading unit, a conversion unit configured to convert analog signals outputted from the first reading unit and the second reading unit to digital signals, a wire connection control unit configured to control wire connection between the first reading unit and the second reading unit, and the conversion unit, and an output control unit configured to control an output of an analog signal from the first reading unit.

An image reading apparatus comprises a first reading unit configured to output an analog signal by reading an original, a second reading unit different from the first reading unit, a conversion unit configured to convert analog signals outputted from the first reading unit and the second reading unit to digital signals, a wire connection control unit configured to control wire connection between the first reading unit and the second reading unit, and the conversion unit, and an output control unit configured to control an output of an analog signal from the first reading unit.