Abstract: An image forming apparatus, in which a method of correcting a positional deviation of a sheet is performed, includes a detecting device to detect a position of the sheet, a pair of sheet conveying bodies to convey the sheet and correct the positional deviation of the sheet, an image forming device to form an image on the sheet, and circuitry to calculate a first positional deviation amount of the sheet based on a first detection result of the detecting device, cause the pair of sheet conveying bodies to correct the positional deviation of the sheet based on the first positional deviation amount, calculate a second positional deviation amount of the sheet based on a second detection result of the detecting device, and cause the image forming device to correct the positional deviation of an image forming position on the sheet based on the second positional deviation amount.

Abstract: An abnormality detecting device includes: a light emitter including a light-emitting element disposed at one side of a conveyed medium, and configured to emit a laser beam having a width in a thickness direction of the medium by the light-emitting element; a light receiver disposed at the other side of the medium to be opposed to the light emitter across the medium, including a plurality of light-receiving elements arranged in the thickness direction of the medium, and configured to receive, by the plurality of light-receiving elements, the laser beam emitted by the light emitter; and a detecting unit configured to detect a lift of the medium in a case where a number of light-receiving elements indicating received light amounts not exceeding a first threshold and being arranged successively in the thickness direction among the plurality of light-receiving elements exceeds a second threshold.

Abstract: A liquid ejection apparatus includes a first control unit, a light projection unit, a light reception unit, a determination unit, and a liquid ejection head. The first control unit is configured to change a threshold for determining a lifting of a recording medium conveyed along a conveyance path according to thickness of the recording medium. The light projection unit is configured to emit a detection beam for detecting the lifting of the recording medium. The light reception unit is configured to receive the detection beam. The determination unit is configured to determine the lifting of the recording medium, when the recording medium is detected with a height greater than the threshold by the detection beam. The liquid ejection head is configured to eject liquid to the recording medium.

Abstract: An abnormality detecting device includes: a light emitter including a light-emitting element disposed at one side of a conveyed medium, and configured to emit a laser beam having a width in a thickness direction of the medium by the light-emitting element; a light receiver disposed at the other side of the medium to be opposed to the light emitter across the medium, including a plurality of light-receiving elements arranged in the thickness direction of the medium, and configured to receive, by the plurality of light-receiving elements, the laser beam emitted by the light emitter; and a detecting unit configured to detect a lift of the medium in a case where a number of light-receiving elements indicating received light amounts not exceeding a first threshold and being arranged successively in the thickness direction among the plurality of light-receiving elements exceeds a second threshold.

Abstract: A liquid ejection apparatus includes a first control unit, a light projection unit, a light reception unit, a determination unit, and a liquid ejection head. The first control unit is configured to change a threshold for determining a lifting of a recording medium conveyed along a conveyance path according to thickness of the recording medium. The light projection unit is configured to emit a detection beam for detecting the lifting of the recording medium. The light reception unit is configured to receive the detection beam. The determination unit is configured to determine the lifting of the recording medium, when the recording medium is detected with a height greater than the threshold by the detection beam. The liquid ejection head is configured to eject liquid to the recording medium.

Abstract: An image forming apparatus, in which a method of correcting a positional deviation of a sheet is performed, includes a detecting device to detect a position of the sheet, a pair of sheet conveying bodies to convey the sheet and correct the positional deviation of the sheet, an image forming device to form an image on the sheet, and circuitry to calculate a first positional deviation amount of the sheet based on a first detection result of the detecting device, cause the pair of sheet conveying bodies to correct the positional deviation of the sheet based on the first positional deviation amount, calculate a second positional deviation amount of the sheet based on a second detection result of the detecting device, and cause the image forming device to correct the positional deviation of an image forming position on the sheet based on the second positional deviation amount.