just one example of a configuration that may be implemented in a laser printer other configurations are possible for example the configuration of slot 54 and gap 66 may be adjusted for the use of different size toner particles in dry toners or possibly even for the use of liquid toners as well to accommodate different sizes shapes and or performance characteristics of developer roller 42 fig5 and 6 show a vertically oriented laser printer 68 printer 68 illustrates one exemplary implementation for a toner supply device such as device 36 described above with reference to fig3 and 4 referring first to fig5 sheets 70 of paper or other print media are fed into printer 68 from an input tray 72 and printed sheets 74 are discharged to an output tray 76 a replaceable print cartridge 78 and other printer components are enclosed in a housing 80 referring now also to fig6 printer 68 includes a charging roller 82 for charging the surface of a photoconductive drum 84 to a relatively high and substantially uniform level the surface of photoconductive drum 84 includes photosensitive material that can be charged and discharged a laser scanner 86 emits a beam of light 88 onto the uniformly charged surface of photoconductive.