A device includes a current sensor, a first current monitor, and a second current monitor. The current sensor is to sense a current between an input node and an output node. The first current monitor is to disconnect the input node from the output node in response to the sensed current exceeding a first threshold current for a period exceeding a threshold period. The second current monitor is to disconnect the input node from the output node in response to the sensed current exceeding a second threshold current greater than the first threshold current.

A device includes a current sensor, a first current monitor, and a second current monitor. The current sensor is to sense a current between an input node and an output node. The first current monitor is to disconnect the input node from the output node in response to the sensed current exceeding a first threshold current for a period exceeding a threshold period. The second current monitor is to disconnect the input node from the output node in response to the sensed current exceeding a second threshold current greater than the first threshold current.

A pressureless high-frequency suspension thermal transfer printer is disclosed, in which a high-frequency signal of 60-100 Hz is generated by a high-frequency switching power supply, and a high-frequency energy conversion motor is driven to convert a signal into high-frequency mechanical vibration which produces 60-100 Hz high-frequency waves which propagate in a longitudinally diffused manner in which an entire transfer printing surface is covered in a direction that is perpendicular to the transfer printing surface, avoiding wasteful loss in the direction of lateral propagation parallel to the transfer printing surface, so that the high-frequency waves act on a molecular movement during the transfer printing process to the greatest extent, which effectively changes a state of the molecular movement, enhances a molecular penetration force, realizes replacement of physical pressure with the high-frequency waves, completely changes a thermal transfer printing process, and achieves pressureless thermal transfer printing.

An image forming apparatus includes a plurality of photosensitive drums respectively corresponding to a plurality of colors to print, on a recording medium, color chart of a plurality of vertical lines in a sub-scanning direction to a main scanning direction of the recording medium and to be arranged at intervals along the main scanning direction. A vertical line of the plurality of vertical lines includes at least two colored sub-lines to be formed by corresponding at least two photosensitive drums. A processor is to perform a correction in non-linear color registrations in the main scanning direction using an image of the color chart.

The present disclosure is drawn to printing systems. In one example, a printing system can include an electrode having a plurality of electrode protrusions associated therewith and a conductive plate. The electrode and conductive plate can be positioned with respect to one another to generate an electric field therebetween and to allow a media substrate to be positioned therebetween to be exposed to the electric field. Additionally, an inkjet print head can form a printed image on the media substrate after exposure to the electric field.

The present disclosure is drawn to printing systems. In one example, a printing system can include an electrode having a plurality of electrode protrusions associated therewith and a conductive plate. The electrode and conductive plate can be positioned with respect to one another to generate an electric field therebetween and to allow a media substrate to be positioned therebetween to be exposed to the electric field. Additionally, an inkjet print head can form a printed image on the media substrate after exposure to the electric field.

An image forming method includes: applying a resin powder to a first area of an object to be subjected to image forming; applying a water-based ink comprising pigments to a second area of the object by an inkjet method to form an image, the first area and the second area at least partially overlapping each other; and heating the first area and the second area to fix the resin powder and the water-based ink to the object. By contact with the resin powder, the water-based ink either thickens, or causes an aggregation of the pigments.

An image forming apparatus includes an image former to print on a printing paper a plurality of lines that are arranged at intervals in a main scanning direction and are vertical to the main scanning direction using different photosensitive drums, a scanner is to scan the printing paper on which the plurality of lines are printed to obtain a scanned image usable in a color registration correction.

An electrophotographic image forming apparatus includes: an image carrier that carries and conveys a toner image; a charging member arranged in contact with or close to the image carrier; a charging power supply that charges the image carrier; an exposurer that forms a latent image on the charged image carrier; a developing member arranged close to the image carrier; a developing power supply that develops the latent image and forms a toner image on the image carrier; a transfer member that transfers the toner image to a medium; and a hardware processor that controls the image forming apparatus, wherein the hardware processor obtains a potential of an exposure part and a non-exposure part, on the image carrier after the toner image has been transferred to the medium, determines a charging bias based on a difference between the obtained potentials, and determines a developing bias based on the determined charging bias.

An electrophotographic image forming apparatus includes: an image carrier that carries and conveys a toner image; a charging member arranged in contact with or close to the image carrier; a charging power supply that charges the image carrier; an exposurer that forms a latent image on the charged image carrier; a developing member arranged close to the image carrier; a developing power supply that develops the latent image and forms a toner image on the image carrier; a transfer member that transfers the toner image to a medium; and a hardware processor that controls the image forming apparatus, wherein the hardware processor obtains a potential of an exposure part and a non-exposure part, on the image carrier after the toner image has been transferred to the medium, determines a charging bias based on a difference between the obtained potentials, and determines a developing bias based on the determined charging bias.