A medium feeding device includes: a placement unit on which a medium is placed; a feeding section that feeds the medium placed on the placement unit; a wrinkle detection section that is provided on a further upstream side than the feeding section in a feeding direction and outputs a detection value in accordance with a wrinkle in the medium; and a control section that performs predetermined control on the basis of the detection value of the wrinkle detection section and stops the feeding section in a case in which the detection value output from the wrinkle detection section exceeds a predetermined allowable value.

An image forming apparatus including: a measurer which measures a physical property of a medium on which an image is formed; an image forming operator which forms the image on the medium; a reader which reads the formed image; and a hardware processor which specifics a medium type based on a measurement result by the measurer and a reading result by the reader.

An image reading apparatus includes an image reading unit, a document pressing unit, a first position detection unit, a second position detection unit, and a controller. The image reading unit reads an image of a document. The document pressing unit presses the document against a document placement component. The first position detection unit detects a first closed position at which the document pressing unit is not in contact with the document placement component. The second position detection unit detects a second closed position that is closer to the document placement component than the first closed position is. The controller performs first width detection on the document and further performs second width detection. The first width detection is performed in accordance with detection performed by the first position detection unit on a closing operation of the document pressing unit. The second width detection is performed after elapse of a predetermined time in accordance with detection performed by the second position detection unit on the closing operation of the document pressing unit. If the controller receives an image reading instruction before the elapse of the predetermined time, the controller performs the second width detection without waiting for the elapse of the predetermined time and starts an image reading process.

An image reading apparatus includes an image reading unit, a document pressing unit, a first position detection unit, a second position detection unit, and a controller. The image reading unit reads an image of a document. The document pressing unit presses the document against a document placement component. The first position detection unit detects a first closed position at which the document pressing unit is not in contact with the document placement component. The second position detection unit detects a second closed position that is closer to the document placement component than the first closed position is. The controller performs first width detection on the document and further performs second width detection. The first width detection is performed in accordance with detection performed by the first position detection unit on a closing operation of the document pressing unit. The second width detection is performed after elapse of a predetermined time in accordance with detection performed by the second position detection unit on the closing operation of the document pressing unit. If the controller receives an image reading instruction before the elapse of the predetermined time, the controller performs the second width detection without waiting for the elapse of the predetermined time and starts an image reading process.

A recognition system including: a specifier that specifies a person who approaches an image forming apparatus using predetermined user information; a memory that stores the person specified by the specifier; a recognizer that recognizes at least any of the stored persons as a candidate who carries away a recording medium on which an image is formed on the basis of a user's print job; and a notificator that notifies a message regarding carrying away of the recording medium on which the image is formed to the recognized candidate.

A sheet feeding sub tray is detachably attachable to a sheet loading stand of a sheet conveying device that includes a setting reference part on one end side of the sheet loading stand in a sheet width direction. The sheet feeding sub tray includes a small-size setting reference part disposed at a position closer to a center of the sheet loading stand in the sheet width direction than the setting reference part in a state in which the sheet feeding sub tray is installed to the sheet loading stand.

A medium feeding device includes: a placement unit on which a medium is placed; a feeding section that feeds the medium placed on the placement unit; a wrinkle detection section that is provided on a further upstream side than the feeding section in a feeding direction and outputs a detection value in accordance with a wrinkle in the medium; and a control section that performs predetermined control on the basis of the detection value of the wrinkle detection section and stops the feeding section in a case in which the detection value output from the wrinkle detection section exceeds a predetermined allowable value.

A paper thickness detecting device that detects a paper thickness in accordance with a detection signal of a displacement sensor, includes: a pair of paper thickness detecting rollers including a first roller and a second roller that pinch a paper conveyed via a pair of conveyance rollers; and the displacement sensor that detects a displacement amount of the pair of paper thickness detecting rollers at the time when the paper passes through the pair of paper thickness detecting rollers, wherein the paper thickness is detected on the basis of the displacement amount of the pair of paper thickness detecting rollers that follows to rotate with respect to the paper conveyed via the pair of conveyance rollers.

A sheet feeding device comprising: a stacking member on which a sheet is stacked; a first conveying portion that conveys a sheet stacked on the stacking member; a second conveying portion that separates and conveys a sheet conveyed by the first conveying portion; a stopper member that stops a sheet whose front end is abutted against the stopper member at an upstream of the second conveying portion in a sheet conveying direction, wherein the stopper member can be at a first position where the sheet can be stopped and a second position where the sheet can pass the stopper member, and wherein the stopper member can move from the first position toward the second position such that a sheet conveyed by the first conveying portion reaches the second conveying portion while maintaining a state where the front end of the sheet is abutted to the stopper member.

A sheet feeding sub tray is detachably attachable to a sheet loading stand of a sheet conveying device that includes a setting reference part on one end side of the sheet loading stand in a sheet width direction. The sheet feeding sub tray includes a small-size setting reference part disposed at a position closer to a center of the sheet loading stand in the sheet width direction than the setting reference part in a state in which the sheet feeding sub tray is installed to the sheet loading stand.