HP INDIGO B.V.

In one example of the disclosure, a substantially transparent substrate is provided at a printer. A primer layer is applied upon a first surface of the substrate. A security ink layer that includes security information is applied upon the primer layer. An opaque background ink layer is applied upon the security ink layer. A corona treatment is applied to a second surface, located on an opposite side of the substrate relative to the first surface. A release ink layer is applied upon the corona-treated second surface. An opaque cover image ink layer is applied upon the release ink layer.

In one example of the disclosure, a substantially transparent substrate is provided at a printer. A primer layer is applied upon a first surface of the substrate. A security ink layer that includes security information is applied upon the primer layer. An opaque background ink layer is applied upon the security ink layer. A corona treatment is applied to a second surface, located on an opposite side of the substrate relative to the first surface. A release ink layer is applied upon the corona-treated second surface. An opaque cover image ink layer is applied upon the release ink layer.

In one example of the disclosure, a substantially transparent substrate is provided at a printer. A primer layer is applied upon a first surface of the substrate. A security ink layer that includes security information is applied upon the primer layer. An opaque background ink layer is applied upon the security ink layer. A corona treatment is applied to a second surface, located on an opposite side of the substrate relative to the first surface. A release ink layer is applied upon the corona-treated second surface. An opaque cover image ink layer is applied upon the release ink layer.

A printing system comprises a print station and print medium transport system. The print medium transport system comprises a track and a transport apparatus engaged with the track. The track defines a transport path past the print station, the transport path has a print medium entry point and a print medium exit point. The transport apparatus comprises: a drive for moving the transport apparatus along the track; and a gripping system. The gripping system can be moved between a first position in which a sheet of print medium is gripped and a second position in which the sheet of print medium is released. In use, the gripping system is configured to be in the first position when the transport apparatus is in motion along the track from the print medium entry point to the print medium exit point.

In an example, a rotogravure printer roller is described. The printer roller ( 300 ) comprises a contact surface formed from a plurality of adjacent roller sections ( 302, 304 ). The roller sections are constructed and arranged to be removably assembled to form the roller.

According to some examples in the disclosure, a method may comprise providing a first stream of discrete volumes of material; and directing a pulsed laser beam at a first discrete volume of material in the first stream of discrete volumes of material so as to interact with the first discrete volume of material and thereby displace the first discrete volume away from the first stream. An apparatus and a system are also disclosed.

In an example, monitoring circuitry includes a first and a second coupling to electrically connect the monitoring circuitry to a monitored circuit having a resistance. The resistance of the monitored circuit may be indicative of a status, and the monitored circuit may be connected in series between the first and second coupling. The first coupling comprises a plurality of galvanically separated connection elements which are to form an electrical connection with a common connection element of the monitored circuit. The monitoring circuitry further comprises a monitoring apparatus to determine the resistance of the monitored circuit via the first coupling and the second coupling. The monitoring apparatus is to acquire a plurality of electrical values and to use the plurality of electrical values to determine a value of the resistance of the monitored circuit.

There is disclosed a selective wetting apparatus comprising a roller rotatable about a roller axis and comprising a wettable roller surface; an applicator unit having a lip which extends parallel to the roller axis and is radially spaced apart from the roller surface by a gap, wherein the applicator unit is to convey liquid agent towards the roller so that the liquid agent forms a liquid bridge over the gap to wet a wetted axial portion of the roller surface; and a flow guide to direct a gas flow into a regulated axial portion of the gap to locally prevent formation of a liquid bridge, and thereby prevent wetting of a corresponding axial portion of the roller surface.

A liquid electrophotographic (LEP) printing device that includes a photo-imaging plate (PIP) to receive a liquid printing fluid, the liquid printing fluid including a pigment incorporated into a resin, a charge conductor, and a carrier liquid, and a transfer roller to transfer the liquid printing fluid from the PIP to a fabric substrate while wet.

Apparatus and methods are provided for measuring the dryness of primer on a substrate in an inline priming system. In implementations, the apparatus comprises a plurality of measurement electrodes spaced laterally to extend across and contact a primed surface of a substrate following application of a primer to the substrate as it is fed through the inline priming system. A resistance measurement unit is provided as part of the dryness measuring apparatus to, in use, measure the surface resistance of the primed substrate between different measurement electrodes across the primed surface of a substrate. A controller is provided in the dryness measurement apparatus, the controller arranged to, in use: receive the measured surface resistance value and to generate, based on the measured surface resistance values, a dryness profile indicative of the dryness of the primer at locations across the substrate in the direction of the spacing of the electrodes.