Abstract: The present invention relates to a jotting implement that infers hand-jotted information from a jotting surface. The hand-jotted information is any information marked on the jotting surface as a result of writing, jotting, drawing, sketching or in any other manner of marking or depositing marks on the jotting surface. Hand-jotted information is also information traced on the jotting surface without leaving any markings thereon or otherwise produced by the motions executed by the jotting implement with respect to the jotting surface while in contact with the jotting surface. The jotting implement has a nib for jotting and an arrangement for determining when the nib is jotting on the jotting surface. Further, the implement has an optical unit for viewing the jotting surface.

Abstract: An apparatus and a method are disclosed for optically determining a distance r to a feature from an origin or a center. The apparatus uses a beam generation unit for launching a reference beam on a reference path and a first beam on a first path. The center from which distance r is determined is selected such that it is along a line of the reference path and not along a line of the first path. Alternatively, the center can be chosen not to lie along a line of the reference path. A rotation mechanism rotates the reference path and the first path about the center such that the reference beam moves over the feature at a reference time tr and the first beam moves over the feature at a first time t1. A determination unit determines distance r between the center and the feature from an angular velocity ? of the reference beam over the feature and from times tr, t1.

Abstract: An elongate object optically determines at least one of its orientation parameters relative to a plane surface. A probe radiation beam is directed from the object at various angles ? to various locations on the plane, where the angle ? is a periodic function of time. Two angularly-selective radiation detectors oriented at fixed angles ?1 and ?2 sense scattered portions of the beam from two locations at two corresponding times. The orientation parameter is computed from a time difference ?t=t2?t1 between the two times.

Abstract: An apparatus and method for determining an inclination angle ? between an axis of an elongate object such as a cane, a pointer or a jotting implement such as a pen, pencil, stylus or the like and a normal to a plane surface at times when a tip of the elongate object is contacting that plane surface. The apparatus has an emitter mounted on the object for illuminating the plane surface with a probe radiation at an angle ? with respect to the axis of the object. The apparatus also has a detector mounted on the elongate object for detecting a radiation characteristic of a scattered portion of the probe radiation returning from the plane surface and a computing unit for deriving the inclination angle ? from the radiation characteristic. A scanning arrangement, such as a uniaxial or biaxial scanner, or a light guiding optic can be used for varying angle ?, and the probe radiation can be emitted in the form of a scan beam.

Abstract: A method and apparatus for determining a pose of an elongate object and an absolute position of its tip while the tip is in contact with a plane surface having invariant features. The surface and features are illuminated with a probe radiation and a scattered portion, e.g., the back-scattered portion, of the probe radiation returning from the plane surface and the feature to the elongate object at an angle ? with respect to an axis of the object is detected. The pose is derived from a response of the scattered portion to the surface and the features and the absolute position of the tip on the surface is obtained from the pose and knowledge about the feature. The probe radiation can be directed from the object to the surface at an angle ? to the axis of the object in the form of a scan beam. The scan beam can be made to follow a scan pattern with the aid of a scanning arrangement with one or more arms and one or more uniaxial or biaxial scanners. Angle ? can also be varied, e.g.

Abstract: A solid catadioptric lens with a single viewpoint has a spherical refractive surface with a center C on an optical axis of the lens. An ellipsoidal reflective surface of the lens faces the spherical refractive surface such that a first focus F1 of the ellipsoidal reflective surface is coincident with the center C of the spherical refractive surface. Furthermore, the lens has a shaping surface facing the ellipsoidal reflective surface for shaping a light that passes the single viewpoint. The shaping surface can be refractive, reflective or semi-transparent and its shape can be ellipsoidal with its first focus F1? coincident with the second focus F2 of the ellipsoidal reflective surface. The single viewpoint of the lens is at the center C of the spherical reflective surface and is enforced with an aperture that can be positioned at various points inside, on a surface or even outside the lens, depending on the type of shaping surface chosen.

Abstract: An apparatus and method employing principles of stereo vision for determining one or more orientation parameters and especially the second and third Euler angles ?, ? of an elongate object whose tip is contacting a surface at a contact point. The apparatus has a projector mounted on the elongate object for illuminating the surface with a probe radiation in a known pattern from a first point of view and a detector mounted on the elongate object for detecting a scattered portion of the probe radiation returning from the surface to the elongate object from a second point of view. The orientation parameters are determined from a difference between the projected and detected probe radiation such as the difference between the shape of the feature produced by the projected probe radiation and the shape of the feature detected by the detector.