Laser fixing device and image forming apparatus

摘要

A fixing device includes: a plurality of laser irradiation sections each of which emits a laser beam whose wavelength exhibits an absorbance of 80% or more with respect to a corresponding toner; and a control device for controlling the plurality of irradiation sections so that in order to fuse a black toner, (i) a laser irradiation section corresponding to the black toner among the plurality of laser irradiation sections irradiates the black toner with a laser beam thereof, and (ii) the other laser irradiation sections irradiate the black toner with laser beams thereof, where the other laser irradiation sections do not correspond to the black toner among the plurality of laser irradiation sections. Therefore, it is possible to provide a laser fixing device which can fix a color toner while preventing an increase in size of the fixing device as much as possible.

主权项

1. A laser fixing device for use in an electrophotographic image forming apparatus for forming an image on a sheet by use of a plurality of toners of different colors, the laser fixing device fusing a toner adhering to the sheet among the plurality of toners by irradiating the toner with a laser beam so as to fix the toner on the sheet, the laser fixing device comprising:
a plurality of laser irradiation sections for outputting laser beams of different wavelengths, respectively, wherein each of the plurality of toners corresponds to one of the plurality of laser irradiation sections, and each of the plurality of laser irradiation sections outputs a laser beam whose wavelength exhibits an absorbance of 80% or more with respect to a corresponding one of the plurality of toners; and a control section for carrying out irradiation control in which the plurality of laser irradiation sections are controlled so that in order to fuse a target toner which is at least one of the plurality of toners, (i) a laser irradiation section, corresponding to the target toner among the plurality of laser irradiation sections, irradiates the target toner with a laser beam thereof, and simultaneously (ii) at least one of the other laser irradiation sections among the plurality of laser irradiation sections also irradiates the target toner with a laser beam thereof; wherein the control section carries out the irradiation control also in a region including only the target toner; wherein each of the plurality of laser irradiation sections emits a laser beam on a sheet in a direction oblique to the normal line of the sheet; the plurality of laser irradiation sections are provided independently; wherein the plurality of laser irradiation sections comprise a first toner laser irradiation section, a second toner laser irradiation section, a third toner laser irradiation section, and a fourth toner laser irradiation section; wherein a first toner is black toner and the first toner laser irradiation section is a black toner laser irradiation section; wherein when a black-and-white image is to be formed the control section carries out the irradiation control by simultaneously using the black toner laser irradiation section, the second toner laser irradiation section, the third toner laser irradiation section, and the fourth toner laser irradiation section; and where when one of a second toner, a third toner, and a fourth toner is to be irradiated, the control section carries out the irradiation control by simultaneous using the black toner laser irradiation section in addition to a respective one of the second toner laser irradiation section, the third toner laser irradiation section, and fourth toner laser irradiation section.