Patent ID: 7621615
Filing Date: 2009-11-24
Classification: B41J

Abstract:
1. A print medium identifying device that identifies the type of a print medium used for a printing apparatus, the print medium identifying device comprising: a light emitting section that irradiates a surface of the print medium with ultraviolet light and infrared light having a longer wavelength than the ultraviolet light; a light receiving section that receives the light applied by the light emitting section and reflected by the surface of the print medium to output a signal corresponding to the quantity of light received; and identifying means for identifying the type of the print medium on the basis of a signal output by the light receiving section when the print medium is irradiated with the ultraviolet light and a signal output by the light receiving section when the print medium is irradiated with the infrared light, wherein the light emitting section is arranged such that an incident angle of the ultraviolet light is smaller than the incident angle of the infrared light, wherein the print medium identified by the identifying means includes ordinary paper, glossy paper, and matte paper, and wherein the identifying means identifies the print medium as glossy paper in the case where the signal output obtained from the reflected infrared light by the light receiving section is smaller than a second predetermined value when the print medium is irradiated with the infrared light, and identifies the print medium as matte paper in the case where the signal output obtained from the reflected infrared light by the light receiving section is larger than the second predetermined value when the print medium is irradiated with the infrared light and the signal output obtained from reflected ultraviolet light by the light receiving section is larger than a first predetermined value when the print medium is irradiated with the ultraviolet light, and identifies the print medium as ordinary paper in the case where the signal output obtained from reflected infrared light by the light receiving section is larger than the second predetermined value when the print medium is irradiated with the infrared light and the signal output obtained from the reflected ultraviolet light by the light receiving section is smaller than the first predetermined value when the print medium is irradiated with the ultraviolet light.