An image forming apparatus including an image forming device, a sensor, and a processor. The image forming device is to form an image on recording medium. The sensor is to irradiate light to the recording medium and detect an amount of light transmitted through the recording medium and an amount of light reflected from the recording medium, resulting in a control of a printing operation of the image forming device based the amount of light transmitted through the printing medium and the amount of light reflected from the printing medium.

An apparatus for determining the thickness of media is provided and includes a ferrous plate, a solenoid mounted perpendicular to the ferrous plate, and a magnet at the end of the solenoid piston. The solenoid piston ranges from a retract position to a down position where the magnet presses on media fed in the gap between the solenoid piston and the ferrous plate. A current source connected to the solenoid moves the piston to the retract position when the current source is energized. A detector is provided to determine when the solenoid piston is in the retract position. A programmable device controls the current source and a time measurement device. The programmable device simultaneously starts the time measurement device and increases current to the solenoid, thereby retracting the piston and timing the retraction.

An image forming apparatus includes: an image carrier; a toner image forming unit that forms a toner image on the image carrier; a transfer unit that transfers the toner image on the image carrier to a transfer target having ridges and valleys on a surface thereof; an adjusting unit that adjusts a ratio of A/B, where A is a transfer ratio [%] from the image carrier to a valley portion of the transfer target while B is a transfer ratio [%] from the image carrier to a ridge portion of the transfer target, based on an adjustment input by a user; and a control unit that controls a transfer condition of the transfer unit based on the ratio of A/B adjusted by the adjusting unit.

An optical sensor includes a light source; and an optical detector detecting intensity of light that is reflected by a recording medium, the light from the light source and irradiated onto the recording medium. Further, when an incident angle of the light incident to the recording medium from the light source relative to a normal line of the recording medium is given as 1, a formula 75185 is satisfied.

An image forming apparatus including an image forming device, a sensor, and a processor. The image forming device is to form an image on recording medium. The sensor is to irradiate light to the recording medium and detect an amount of light transmitted through the recording medium and an amount of light reflected from the recording medium at each of a plurality of positions. The processor is to determine a thickness of the recording medium based on the amount of light transmitted through the recording medium and the amount of light reflected from the recording medium at each of the plurality of positions. The processor is to then control the image forming device on the basis of the determined thickness.

A printing apparatus capable of conveying sheets to a sheet processing apparatus and to control the type of a sheet to be used as a cover sheet in a case where a book bound product is generated by switching back sheets each having an image printed, inverting the sheets and folding the inverted sheets, and to notify an error to a user based on the type of a sheet to be used as the cover sheet in a case where printing an image on the cover sheet is designated.

An optical sensor includes a light source; and an optical detector detecting intensity of light that is reflected by a recording medium, the light from the light source and irradiated onto the recording medium. Further, when an incident angle of the light incident to the recording medium from the light source relative to a normal line of the recording medium is given as 1, a formula 75185 is satisfied.

A printing apparatus capable of conveying sheets to a sheet processing apparatus and to control the type of a sheet to be used as a cover sheet in a case where a book bound product is generated by switching back sheets each having an image printed, inverting the sheets and folding the inverted sheets, and to notify an error to a user based on the type of a sheet to be used as the cover sheet in a case where printing an image on the cover sheet is designated.

A thickness detector includes a rotator having different shape marks, disposed at different positions in a rotation direction; an opposing member disposed opposite the rotator; a detector to detect and output a displacement amount of the rotator or the opposing member in a sheet thickness direction; and a controller. The controller is configured to acquire first output values for one rotation from the detector, in a state without sheet; determine, based on a value output from the detector, whether one of the plurality of marks is detected in a state with the sheet held; acquire a predetermined number of second output values after one of the marks is detected; extract, from the first output values, values corresponding to the second output values, based on the value corresponding to the detected mark; and calculate a sheet thickness based on the second output values and the extracted first output values.

In an example implementation, a stackable component assembly includes a first stackable component with a bottom recess in its bottom surface, and a second stackable component with a top recess in its top surface. A first alignment element is installed in the bottom recess and a second alignment element is installed in the top recess. The second alignment element is nestable within the first alignment element to align the first and second stackable components upon stacking the first stackable component onto the second stackable component.