Abstract: To provide a cutter knife which can be stepwise automatically locked while preventing a leaf spring from being unusably deformed. A holder 1 has engaging recesses 1b of an isosceles trapezoid formed in its upper face, and a slider is so inserted in a slide groove as to move back and forth. In a center recess 2g formed in a body member 2 of the slider, there is inserted a leaf spring 4. In an opening 2d into and out of which the protruding portion of the leaf spring 4 is to go, there is disposed a boss 2e which is erected on the body member to regulating the movement of the leaf spring. An operation member 3, as movably supported by the body member, is provided with an engaging groove 3b and a movable stopper 3c. As the operation member is moved forward or backward, the movable stopper allows the backward movement of the protruding portion, and the engaging groove can depress the protruding portion of the leaf spring out of engagement from the engaging recess so that the slider can be moved.

Abstract: A digital tape measure comprising a tape stored in a case when it is not used and drawn out of an aperture of the case when it is used and onto which a plurality of detection marks are affixed at equivalent interval, a detector of detecting the detection marks by photoelectric transfer elements, a counter of counting the detected signal being output from the detector corresponding to the volume of movement of the tape, a display of displaying the result counted by the counter, and in which a length of each detection mark is established to be a length twice as long as the minimum scale of the tape, the distance between each detection mark is established to be equivalent to the length of each detection mark in the direction of measurement, and the detector comprises two photoelectric transfer elements arranged at the phase difference of 90.degree. and a discriminator of discriminating the output signal from the photoelectric transfer elements.

Abstract: A digital tape measure comprising a tape stored in a casing body being wound on a reel so as to be movable corresponding to a length of measuring object when drawn out and on which a detection mark is indicated and a photoelectric transfer element for receiving a light projected to the tape and reflected therefrom and converting the light to an electric signal, the combination with a control roller for controlling a moving state of the tape on the moving passage which is disclosed between the reel and photoelectric transfer element to form a spacing corresponding to an allowance of the focal distance of the photoelectric transfer element between the roller surface and the tape surface.