Patent ID: 6697584
Filing Date: 2004-02-24
Classification: G03G

Abstract:
An image formation apparatus in which the a discomfort index S of the sound obtained by the following tone quality evaluation equation a) expressed in a regression equation, using regression coefficients of loudness value, sharpness value, tonality value and impulsiveness value of psychoacoustic parameters obtained from the operating noise at a position away from an end face of an image formation apparatus by a predetermined distance:S=AÃ—(loudness value)+BÃ—(sharpness value)+CÃ—(tonality value)+DÃ—(impulsiveness value)+E, where 0.209&lE;A&lE;0.249 0.308&lE;B&lE;0.439 3.669&lE;C&lE;4.984 0.994&lE;D&lE;1.461 âˆ’4.280&lE;E&lE;3.274â€ƒâ€ƒ(a) satisfies the condition of:S&lE;0.6708Ã—nN(ppm)âˆ’2.824 16&lE;ppm&lE;70â€ƒâ€ƒ(b), and where pmm is defined as the number of sheets of A4 lateral size paper printed in one minute, and Ln is natural logarithm.