When round lenses (uncut lenses) are edged so as to fit with the shapes of the left and right rims of a spectacle frame, shifts between the fitting points of the left and right eyes of the spectacle wearer (that are the pupil positions of the left and right eyes of the wearer in a spectacle frame when he or she wears the spectacle frame, and will also be referred to as IPs hereinafter) and the optical centers of the left and right lenses, if any, greatly influence the comfort upon wearing the spectacle. In this respect, it is necessary to precisely measure the interpupillary distance (to be also referred to as PD hereinafter) between the left and right pupils or the distances (to be also referred to as monocular PDs hereinafter) from the center of the bridge of the nose of the wearer to the left and right pupils to determine the optical center distance between the left and right lenses, and edge the respective lenses so that the optical centers of the respective lenses coincide with the IPs of the left and right eyes. To meet this requirement, a measuring tool disclosed in, for example, Japanese Patent Laid-Open No. 8-98810 measures PD or monocular PDs.
A fitting point measuring tool described in Japanese Patent Laid-Open No. 8-98810 easily, precisely measures the positions, in the horizontal direction and height direction, of the pupils of the left and right eyes of the subject. This fitting point measuring tool includes a base member, a clip-shaped attachment portion, and left and right movable members. The base member is placed on the front portion of a spectacle frame parallel to it. The attachment portion is used to attach the base member to the spectacle frame. The movable members are attached to the base member to be movable in its longitudinal direction (horizontal direction), and are individually aligned with the pupils of the left and right eyes of the subject. The base member is marked with horizontal scales for measuring the positions of the pupils in the horizontal direction, and the movable members are marked with vertical scales for measuring the positions of the pupils in the vertical direction.
USPTO Backgrounds
USPTO Backgrounds