A liquid development device includes a storage section storing a liquid developer in which toner is dispersed, a development member to which the liquid developer stored in the storage section is applied using an application unit, a removing device that, after an electrostatic latent image in a latent image-holding member is developed, removes the liquid developer remaining on the development member, and a shearing device that is provided in a path through which the liquid developer removed using the removing device is returned to the storage section, and applies a shear force to the liquid developer removed using the removing device by making the liquid developer pass through a contact section of two members at least one of which rotates and that have different velocities from each other.

A fluid detection apparatus to detect quantity of a fluid having flowability and stored in a casing includes an oscillator disposed outside the casing to output a frequency of an oscillation signal corresponding to a magnetic flux passing through a space near the oscillator, a vibrator made of material effecting the magnetic flux and disposed inside the casing, a vibration trigger disposed inside the casing to vibrate the vibrator, and circuitry to acquire frequency-related information related to the frequency of the oscillation signal output from the oscillator, detect the vibration of the vibrator based on a change of the frequency-related information, determine whether the vibration of the vibrator converges during a convergence-checking time period defined after the vibrator is vibrated by the vibration trigger, and detect the quantity of the fluid in the casing based on a convergence determination result of the vibration of the vibrator.

A characterization apparatus for characterizing a liquid containing insoluble particles includes a housing including an inlet portion defining an inlet passage between an inlet end and a first channel end, a channel portion defining a measurement channel between the first channel end and a second channel end, and an outlet portion defining an outlet passage between the second channel end and an outlet end. The channel portion includes a first electrode and a second electrode at a first and second side of the channel. The apparatus also includes a measurement device configured for measuring an electric measure representative for properties of the liquid flowing between the first electrode and the second electrode. The inlet passage gradually changes shape from the inlet end to the first channel end. The outlet passage gradually changes shape from the second channel end to the outlet end.

In a method to adjust print quality of print images in an electrophoretic digital printer with at least one print group, the print group generates charge images of the print images. The charge images are developed with a developer station into toner images using liquid developer having carrier fluid and toner. The toner images are transfer-printed onto a carrier medium in a transfer station. A first control marking is generated on the recording medium with elements of the first control marking being aligned transverse to a printing direction. A shape of the elements of the first control marking is measured to generate a first measurement signal. The first measurement signal is compared with a predetermined nominal value, and given a difference, an adjustment signal is generated via which an amount of the carrier fluid in the liquid developer is modified so that the first measurement signal approaches the predetermined nominal value.

According to an example, a mixing device comprises a first chamber including a solute addition member and a first mixer, a second chamber including a second mixer, a printing fluid pump, and a controller operatively connected to the solute addition member, the pump, the first mixer, and the second mixer. The controller is to control the pump to move printing fluid towards the printing fluid tank based on a printing fluid density level in the printing fluid tank, to control the solute addition member to add solids based on the printing fluid density level, and to control the first mixer and the second mixer to mix the added solids with the printing fluid moved by the pump.