Abstract: An apparatus for forming an image with modulated image lights which are obtained by modulating an image light in accordance with image signals, including a reference pattern signal generation circuit, a comparator to compare image signals with a reference pattern signal so as to produce a pulse width modulation signal, and a circuit to shift the level of the image signal of either a maximum or minimum value to a level out of the amplitude of the reference pattern signal.

Abstract: A document size detector for detecting a size of a document in use with a document scanner. The document size detector has an irradiator to irradiate the document with a light beam; a cover of the document; a receiver of the reflection light from the document and the cover; a converter to convert the reflection light to image signals; a detector to detect the shadow of the document on the cover in the image signals; and the determiner to determine the size of the document according to the detected shadow of the document.

Abstract: An electric circular saw of the type including a mechanism for tilting a base relative to the plane of a blade is provided wherein a side knob for being gripped by the user during cutting operation pivotally connects the base and a body of the circular saw through a base attachment portion and a bevel plate having an arcuate guide groove extending through an angular distance corresponding to a tilt angle of the base relative to the blade. The side knob is threaded to the base attachment portion and movable together with the base when the base is tilted. The side knob is spaced from a guide surface of the base by a distance at least larger than a maximum radius of the side knob. The distance between the base and the side knob is constant regardless of the relative angular position of said base and the blade, so that circular saw can be held stably and hence is capable of performing an accurate cutting operation.