1. Field of the Invention
The present invention relates to a liquid electrophotographic printer, and more particularly, to a carrier recovery apparatus for recovering a liquid carrier of a developer liquid adsorbed onto a photoreceptor.
2. Description of the Related Art
In general, in a liquid electrophotographic printer employed in a laser printer or a copier, an image formed on a photoreceptor such as a photoreceptor belt is developed using a developer liquid which is a mixture of a toner powder having a predetermined color and a liquid carrier. The developed image is transferred to and printed onto a sheet of paper after the liquid carrier is removed therefrom.
The liquid carrier, made of carbon hydroxide, is a pollutant and harmful to humans. Thus, it is desirable to recover the liquid carrier for recycling.
Referring to FIG. 1 showing a conventional liquid carrier recovery apparatus, a liquid carrier in the developer liquid supplied to an electrostatic latent image formed on a traveling photoreceptor belt 11 is evaporated by a drying roller 122 installed in a drying unit 12, and a heating roller 123 for heating the drying roller 122.
Part of the evaporated carrier contacts a heat transmission fin 121a formed in a housing 121, thereby being cooled and liquefied. The liquefied carrier is recovered through a first recovery tube 124 and stored in a carrier reservoir 15. Any evaporated carrier remaining in the housing 121 is sent to a condenser 14 by a fan 13a driven by a driving motor 13b. The gas carrier introduced into the condenser 14 contacts a condensed carrier maintained at a constant temperature, thereby being cooled and liquefied. The liquefied carrier is recovered through a second recovery tube 141 and stored in the carrier reservoir 15.
Part of the evaporated carrier introduced into the condenser 14 remains in a gaseous state. This gas carrier is filtered by a filter 161 installed in an exhaust unit 16 to prevent the carrier from effusing into the outside environment.
In the conventional carrier recovery apparatus, the cooling capacity of the heat transmission fin 121a is small. Thus, a negligible amount of carrier is liquefied within the drying unit 12, and most of the gas carrier is condensed in the condenser 14. Consequently, the time required for recovering the carrier is long, and the carrier recovery efficiency is low.