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 information processing apparatus includes a light emitting unit and a light receiving unit for receiving light output from the light emitting unit, and includes a detection unit for outputting a light reception signal indicating that the light receiving unit has received light from the light emitting unit, a driving signal output unit for outputting a driving signal to the detection unit so that the light emitting unit intermittently outputs light, a detection signal output unit for outputting, based on the output driving signal and the output light reception signal, a detection signal indicating whether an object exists between the light emitting unit and the light receiving unit, and a control unit including an interrupt port to which the output detection signal is input and for returning from a power saving state in response to the detection signal being input to the interrupt port in the power saving state.

When a reading target object that includes a light emitting region is set as a reading target, the light emitting region is detected by a reading mechanism of a reading unit. The reading unit is caused to read the detected light emitting region, and in the reading, a read operation by the reading unit is controlled based on change of an amount of light received from the light emitting region.

To provide a sheet size determining apparatus capable of appropriately determining a sheet size. Specifically, a sheet size detection result is acquired by a sensor, and when there are a plurality of candidate sheet sizes corresponding to the acquired detection result, a sheet size is determined from the plurality of candidate sheet sizes in response to a setting of the operation device that indicates sheet sizes.

A medium feeding device includes a medium placing portion, a feeding roller that feeds paper, a medium movement detecting portion that is positioned on a placing region of the paper of the medium placing portion in a medium feeding direction and is capable of detecting movement of the paper being fed in a width direction intersecting the medium feeding direction, and a controller that stops feeding of the paper in a case in which a physical quantity relating to movement of paper in the width direction exceeds a predetermined threshold based on a detected result by the medium movement detecting portion.

A printer is disclosed, which comprises a frame, an image forming module, a controller, a light guide unit, and an optical detector. The image forming module is disposed opposite to the frame and forms a passage. The light guide unit is disposed in the frame and is connected to the controller. The optical detector comprises an illuminating part and a receiving part. The illuminating part illuminates a beam to the light guide d unit, and the receiving part is for receiving the light.

A medium feeding device includes a medium placing portion, a feeding roller that feeds paper, a medium movement detecting portion that is positioned on a placing region of the paper of the medium placing portion in a medium feeding direction and is capable of detecting movement of the paper being fed in a width direction intersecting the medium feeding direction, and a controller that stops feeding of the paper in a case in which a physical quantity relating to movement of paper in the width direction exceeds a predetermined threshold based on a detected result by the medium movement detecting portion.

A sheet conveyance apparatus includes a conveyance unit and first and second moving members respectively including first and second projection portions. When the first projection portion contacts a sheet, the first moving member is moved from a first projection position, where the first projection portion projects to a conveyance path, to a first retraction position, where the first projection portion is retracted from the first projection position. When the first moving member moves to the first retraction position, the second moving member moves from a second retraction position, where the second projection portion is retracted from the second projection position, to a second projection position, where the second projection portion projects to the conveyance path. When a sheet pushes the second projection portion, the second moving member is moved from the second projection position to the second retraction position with the first moving member located at the first retraction position.

An image forming apparatus includes a scanner and a printing apparatus, wherein the scanner includes a scanning window; a transport unit configured to transport a document to a top surface of the scanning window; a scan unit configured to obliquely irradiate light to a bottom surface of the scanning window to scan the document; a transport guide member configured to be disposed to face the top surface of the scanning window to guide a transport of the document; and a curved reflection member configured to be coupled to the transport guide member to collect the light irradiated from the scan unit and to reflect the collected light toward the scanning window.

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.