A scanning carriage of a printer includes a first emitter to emit first airborne charges, a second emitter to emit second airborne charges, and a fluid ejection device interposed between the first and second emitters to deposit droplets of ink particles within a non-aqueous fluid carrier onto a print medium to form an image. The carriage is movable relative to the print medium in a first direction and an opposite second direction. In the first direction, the first emitter is to electrostatically discharge the medium and the second emitter is to induce electrostatic fixation of the ink particles relative to the medium. In the opposite second direction, the second emitter is to electrostatically discharge the medium and the first emitter is to induce electrostatic fixation of the ink particles relative to the medium.

An optical scanning device (12) includes cleaning holders (511, 512), light transmitting members (52), a linear member (54), a winding motor (55), and stoppers (56a, 56b). The two cleaning holders (511, 512) are coupled to the linear member (54). The linear member 54 is driven to circulate by the winding motor (55), whereby the two cleaning holders (511, 512) move and each cleaning member slides on a corresponding one of the light transmitting members (52). When the cleaning holders (511, 512) come into contact with the respective stoppers (56a, 56b), the stoppers (56a, 56b) restrict movement of the respective cleaning holders (511, 512) in one of directions of extension of the light transmitting members (52). A contact determining section (913) determines, based on a current value of the winding motor (55), that the cleaning holder (511, 512) has come into contact with the stopper (56a, 56h).

In a first image formation mode, an image is formed with a first development contrast C1 and a specific dot pattern is formed with a second development contrast C2, which is lower than the first development contrast C1; in a second image formation mode, an image is formed with a third development contrast C3 and a specific dot pattern is formed with a fourth development contrast C4, which is lower than the third development contrast C3; and when ΔC1 (=C2/C1) denotes a ratio between the second development contrast C2 and the first development contrast C1, and ΔC2 (=C4/C3) denotes a ratio between the fourth development contrast C4 and the third development contrast C3, ΔC2<ΔC1 is satisfied.

A printing assembly for thermal transfer printing is disclosed. The assembly comprises at least one first printing system comprising a transfer member having an imaging surface on the front side, a coating station at which a monolayer of thermoplastic particles is applied to the imaging surface, an imaging station at which electromagnetic radiation (EM) is applied, optionally via the rear side of the transfer member, to selected regions of the imaging surface to render the particles coating the selected regions tacky, a transfer station at which only the regions of the particles coating that have been rendered tacky are transferred to a substrate to form an adhesive image; and at least one more downstream printing system. The transfer member includes on its front side an EM radiation absorbing layer, the imaging surface being formed on, or as part of, the absorbing layer, and on its rear side a body which can optionally be transparent to EM radiation.

In a first image formation mode, an image is formed with a first development contrast C1 and a specific dot pattern is formed with a second development contrast C2, which is lower than the first development contrast C1; in a second image formation mode, an image is formed with a third development contrast C3 and a specific dot pattern is formed with a fourth development contrast C4, which is lower than the third development contrast C3; and when C1 (=C2/C1) denotes a ratio between the second development contrast C2 and the first development contrast C1, and C2 (=C4/C3) denotes a ratio between the fourth development contrast C4 and the third development contrast C3, C2<C1 is satisfied.

An optical scanning device (12) includes cleaning holders (511, 512), light transmitting members (52), a linear member (54), a winding motor (55), and stoppers (56a, 56b). The two cleaning holders (511, 512) are coupled to the linear member (54). The linear member 54 is driven to circulate by the winding motor (55), whereby the two cleaning holders (511, 512) move and each cleaning member slides on a corresponding one of the light transmitting members (52). When the cleaning holders (511, 512) come into contact with the respective stoppers (56a, 56b), the stoppers (56a, 56b) restrict movement of the respective cleaning holders (511, 512) in one of directions of extension of the light transmitting members (52). A contact determining section (913) determines, based on a current value of the winding motor (55), that the cleaning holder (511, 512) has come into contact with the stopper (56a, 56b).

In a first image formation mode, an image is formed with a first development contrast C1 and a specific dot pattern is formed with a second development contrast C2, which is lower than the first development contrast C1; in a second image formation mode, an image is formed with a third development contrast C3 and a specific dot pattern is formed with a fourth development contrast C4, which is lower than the third development contrast C3; and when C1 (=C2/C1) denotes a ratio between the second development contrast C2 and the first development contrast C1, and C2 (=C4/C3) denotes a ratio between the fourth development contrast C4 and the third development contrast C3, C2<C1 is satisfied.

In a first image formation mode, an image is formed with a first development contrast C1 and a specific dot pattern is formed with a second development contrast C2, which is lower than the first development contrast C1; in a second image formation mode, an image is formed with a third development contrast C3 and a specific dot pattern is formed with a fourth development contrast C4, which is lower than the third development contrast C3; and when C1 (=C2/C1) denotes a ratio between the second development contrast C2 and the first development contrast C1, and C2 (=C4/C3) denotes a ratio between the fourth development contrast C4 and the third development contrast C3, C2<C1 is satisfied.

A printing assembly for thermal transfer printing is disclosed. The assembly comprises at least one first printing system comprising a transfer member having an imaging surface on the front side, a coating station at which a monolayer of thermoplastic particles is applied to the imaging surface, an imaging station at which electromagnetic radiation (EM) is applied, optionally via the rear side of the transfer member, to selected regions of the imaging surface to render the particles coating the selected regions tacky, a transfer station at which only the regions of the particles coating that have been rendered tacky are transferred to a substrate to form an adhesive image; and at least one more downstream printing system. The transfer member includes on its front side an EM radiation absorbing layer, the imaging surface being formed on, or as part of, the absorbing layer, and on its rear side a body which can optionally be transparent to EM radiation.