Abstract:
A sheet detecting apparatus includes: a light emitting unit that emits light emitted toward a detection position; a light receiving unit that is provided to receive the light reflected by a sheet present at the detection position and that outputs an electric signal which corresponds to a received light amount; and an adjustment processing unit that adjusts, within a specified range, a duty ratio of a drive pulse signal used to drive the light emitting unit, so that a detection value of the electric signal output from the light receiving unit is included in a specified standard range; and a decision processing unit that decides the specified range based on a change range which is among a variable range of the duty ratio of the drive pulse signal and in which the detection value of the electric signal changes in response to a change in the duty ratio.
Abstract:
In an image reading device, an object intrusion detecting device includes a rod-like member disposed along a widthwise direction of a document tray and detects that the rod-like member has been pushed up to a predetermined position in a height direction. When the object intrusion detecting device detects that the rod-like member has been pushed up to the predetermined abnormal position in the height direction, the controller determines that an object intrusion has occurred.
Abstract:
An abnormality detection device for an image forming apparatus detects an abnormality in the image forming apparatus which includes a heating belt looped around a heating roller and a fixing roller. The abnormality detection device for an image forming apparatus includes: thermistors for detecting temperatures of one widthwise end portion and the other widthwise end portion of the heating belt; a temperature difference detection section for determining whether or not a temperature difference between the temperature of the one end portion and the temperature of the other end portion which are detected by the thermistors is greater than a predetermined value; and a judgment section for judging that an abnormality has occurred in the image forming apparatus when it is determined in the temperature difference detection section that the temperature difference is greater than the predetermined value.