Patent ID: 8135294
Filing Date: 2012-03-13
Classification: G01N,G03G

Abstract:
1. An image forming apparatus to form an image on a record medium, comprising: a record medium supply mechanism to supply a record medium one by one; a record medium conveyance path to convey the record medium supplied from the record medium supply mechanism to a record medium discharge unit; a laser light source to irradiate a laser light to a surface of a record medium; a line sensor which has plural optical sensors for the laser light source to receive a reflected light of the laser light from the record medium to output an output signal converted into an electric signal, when the record medium totally reflects the laser light, the line sensor is arranged so that an axis of a sensor of the line sensor in a longitudinal direction is positioned on a plane to which a light path of the laser light irradiated from the laser light source and reflected by the record medium belongs; a signal processing device to determine a kind of the record medium based on the output signal; and an image forming unit that is arranged on a downstream side of the record medium conveyance path with respect to the line sensor and forms an image to the record medium conveyed through the record medium conveyance path; when the record medium is being conveyed, the laser light source irradiates the laser light to the record medium for a definite time, the line sensor receives the reflected light of the laser light from the record medium for the definite time and outputs the output signal converted into the electric signal, and the signal processing device compares a distribution state of an average of the received light intensity for the definite time at the received light position with a previously determined distribution state, and determines the kind of the record medium.