A quality control station (2) for a sheet element processing machine, the station having at least one camera (6) arranged for capturing images of sheet elements (4) transported through the quality control station (2), and further having a camera calibration system (10). The camera calibration system (10) having a target holder (12) for holding an optical target (14), and a drive (15) for the target holder (12). The drive (15) is adapted for displacing the target holder (12) between a rest position, in which it is outside of the viewing area (7) of the camera (6), and a calibration position in which it is arranged in the viewing area (7) of the camera (6).

Example implementations relate to determining a correction factor that converts a measured sensor distance to a calibrated sensor distance. The measured sensor distance may be based on an amount of substrate advancement through a web printing press between detecting a mark on the substrate at a first sensor and detecting the mark at a second sensor. The calibrated sensor distance may be the separation between the first sensor and the second sensor.

A method of testing a functional unit includes an optical sensor system (28) for detecting an optical signal from at least a part of a moving material web (14), a data processing system (36) for valuating the optical signals, and a display (38) displaying a state of the material web (14) and arranged in a sensitive range (30) of the sensor system (28).

A device (100) includes a sensor (101) to determine a capacitance between a first metal piece (209, 309, 409, 509, 609, 709, 809, 909) coupled to a paper tray (213, 413, 513, 913) of a printing device (206, 306) and a second metal piece (207, 307, 407, 507, 607, 707, 807, 907) coupled to a paper width adjuster (212) of the printing device (206, 306).The device (100) also includes a controlled (102) coupled to the sensor (101) comprising a processor (103) in communication with a memory resource (104) including executable instructions to determine a size of paper in the paper tray (213, 413, 513, 913) based on the determined capacitance.

A conveyor conveys a sheet along a conveyance path provided with an ultrasonic sensor, and includes: an updating member that successively updates a parameter indicating aged deterioration of the conveyor; a searcher that searches a look-up table storing pieces of noise data of noises predicted to be superimposed on a detection signal of the ultrasonic sensor in accordance with a degree of the aged deterioration, and obtains a piece of noise data corresponding to a current parameter value of the conveyor; and a signal processor that uses, for signal processing, a remaining portion of the detection signal of the ultrasonic sensor excluding a portion corresponding to the piece of noise data obtained by the searcher.

A transport apparatus includes a speaker and a mike disposed at respective positions between which a transport path of a medium is interposed, where the speaker and the mike face each other, a drive circuit that outputs a drive signal to the speaker, an amplifier circuit formed by coupling a plurality of amplifiers in series, where the amplifier circuit amplifies and outputs an output signal of the mike, a processor to which the output signal of the amplifier circuit is input, an attenuation circuit disposed in a stage preceding a predetermined amplifier, where the attenuation circuit attenuates an input signal and outputs the input signal to the predetermined amplifier, and a switch that switches an attenuation factor by the attenuation circuit.

A paper sheet detection device includes: an optical sensor that includes a light-emitting portion that emits light, and a light-receiving portion that receives the emitted light; a storage portion that stores a first threshold value used for determining whether or not a paper sheet is present in a path of the emitted light, a target light-receiving level set as a target value of a level of the light received by the light-receiving portion in a state where the paper sheet is not present, and a second threshold value that is set to a value that is greater than the first threshold value and less than the target light-receiving level; an estimating portion that determines whether the level of the light received by the light-receiving portion is equal to or greater than the first threshold value and less than the second threshold value, and that estimates whether or not the paper sheet is present; and a light amount adjusting portion that adjusts an amount of the light emitted by the light-emitting portion so that the level of the light received by the light-receiving portion becomes the target light-receiving level in the state where the paper sheet is not present when the estimating portion estimates that the paper sheet is not present after the estimating portion determines that the level of the light received by the light-receiving portion is equal to or greater than the first threshold value and less than the second threshold value.

A multifeed detection device that detects multifeed by using an ultrasonic wave includes an ultrasonic emitting unit and an ultrasonic receiving unit arranged to oppose each other with a medium transport path interposed therebetween; judges occurrence of multifeed of media based on a detection intensity of an ultrasonic wave received by the ultrasonic receiving unit, and a multifeed threshold for judging multifeed of media; and acquires first information that is information relating to adjustment for the multifeed threshold, and second information for specifying that the first information is the information relating to the adjustment for the multifeed threshold, from a calibration sheet holding the first information and the second information.

A medium transport apparatus includes a medium transport path through which a medium passes, a path state detection section configured to output a detection value corresponding to a state of the medium transport path, a control section configured to compare the detection value output by the path state detection section with a threshold value for the detection value and determine whether an abnormal condition has occurred in the medium transport path, and a storage configured to store history information including the detection value acquired in the past, in which the control section changes the threshold value based on the history information.

In one example of the disclosure, an uncalibrated sensor may be calibrated. Calibrated sensor data is obtained. The data relates to an amount of light transmitted through an ink solution of a first colour as a function of ink concentration. An amount of light transmitted through an ink solution of the first colour is measured, using the uncalibrated sensor, at a plurality of ink concentrations. A calibration factor relating the light transmission of the calibrated sensor for the first colour and the light transmission of the uncalibrated sensor for the first colour is determined, using a processor, based on the obtained data and the measurements.