This disclosure relates to a printing device for printing or dispensing a curable printing composition which is capable of changing color in response to the application of a magnetic field in the non-cured state. The printing device may be a handheld device such as a portable pen. The present disclosure further relates to curable compositions, cartridges and methods which may be used in combination with the aforementioned printing devices or in other applications.

This disclosure relates to a printing device for printing or dispensing a curable printing composition which is capable of changing color in response to the application of a magnetic field in the non-cured state. The printing device may be a handheld device such as a portable pen. The present disclosure further relates to curable compositions, cartridges and methods which may be used in combination with the aforementioned printing devices or in other applications.

An electrohydrodynamic print head includes a plurality of nozzles and a common electrode. Separately controllable electrostatic fields between the common electrode and each nozzle are provided. The common electrode can also shield adjacent electrostatic fields from each other. Each nozzle can be associated with separately controllable gas flow fields and separately back pressures. The print head enables simultaneous e-jet printing of different printing fluids and/or different resolutions. The print head may be part of a printing system with interchangeable cartridges. Each cartridge has multiple nozzles, and printing fluid extraction parameters can be made separately controllable for each nozzle.

An electrohydrodynamic print head includes a plurality of nozzles and a common electrode. Separately controllable electrostatic fields between the common electrode and each nozzle are provided. The common electrode can also shield adjacent electrostatic fields from each other. Each nozzle can be associated with separately controllable gas flow fields and separately back pressures. The print head enables simultaneous e-jet printing of different printing fluids and/or different resolutions. The print head may be part of a printing system with interchangeable cartridges. Each cartridge has multiple nozzles, and printing fluid extraction parameters can be made separately controllable for each nozzle.

This disclosure relates to a printing device for printing or dispensing a curable printing composition which is capable of changing color in response to the application of a magnetic field in the non-cured state. The printing device may be a handheld device such as a portable pen. The present disclosure further relates to curable compositions, cartridges and methods which may be used in combination with the aforementioned printing devices or in other applications.

This disclosure relates to a printing device for printing or dispensing a curable printing composition which is capable of changing color in response to the application of a magnetic field in the non-cured state. The printing device may be a handheld device such as a portable pen. The present disclosure further relates to curable compositions, cartridges and methods which may be used in combination with the aforementioned printing devices or in other applications.

An electrohydrodynamic print head includes a plurality of nozzles and a common electrode. Separately controllable electrostatic fields between the common electrode and each nozzle are provided. The common electrode can also shield adjacent electrostatic fields from each other. Each nozzle can be associated with separately controllable gas flow fields and separately back pressures. The print head enables simultaneous e-jet printing of different printing fluids and/or different resolutions. The print head may be part of a printing system with interchangeable cartridges. Each cartridge has multiple nozzles, and printing fluid extraction parameters can be made separately controllable for each nozzle.

An inkjet head device comprises a body comprising light emitting devices, a nozzle installed on a lower side of the body to spray the light emitting devices onto the substrate in units of droplets, and a first guide part disposed in the body to guide the light emitting devices to the nozzle in a line. Since the light emitting devices arranged in a line by the first guide part are dropped on the substrate in units of a predetermined amount of droplets, the number of light emitting devices included in each droplet may be the same or similar. Thus, since the same or similar number of light-emitting elements are disposed or aligned in each sub-pixel, the luminance in each sub-pixel obtained by the light-emitting elements can be uniform.

An inkjet head device comprises a body comprising light emitting devices, a nozzle installed on a lower side of the body to spray the light emitting devices onto the substrate in units of droplets, and a first guide part disposed in the body to guide the light emitting devices to the nozzle in a line. Since the light emitting devices arranged in a line by the first guide part are dropped on the substrate in units of a predetermined amount of droplets, the number of light emitting devices included in each droplet may be the same or similar. Thus, since the same or similar number of light-emitting elements are disposed or aligned in each sub-pixel, the luminance in each sub-pixel obtained by the light-emitting elements can be uniform.

An inkjet amount measuring system, an inkjet amount measuring method and an inkjet amount controlling method. The inkjet amount measuring system includes: an inkjet printing spray head; and electricity applying device configured to apply electric charges to ink droplets passing through a nozzle of the inkjet printing spray head; a magnetic field generating device configured to generate a magnetic field to deflect the charged ink droplets; a test board having a surface for carrying ink droplets; and a processor configured to calculate an amount of ink droplets according to positions of falling points of the ink droplets on the surface of the test board, an electric charge amount of the ink droplets, and a magnetic field intensity.