Arc Design, Inc.

Yoshio Yamazaki

Shigeru Oshima

A cylindrical grooved cam with a plurality of grooved cams provided on its inner cylindrical surface comprises an inner tube having at least two guide walls that are provided on its lower edge and represent one guide wall line of the grooved cam to be formed on the inner cylindrical surface; and an outer tube having at least two guide walls that are provided on its upper edge of protruded area on its cylindrical inner surface and represent the other guide wall line of the grooved cam to be formed on the inner cylindrical surface; wherein the inner tube is to be inserted into the outer tube from above so that the guide walls of the inner tube and the counter part guide walls of the outer tube form the grooved cams on the inner cylindrical surface of the cylindrical grooved cam.

Cylindrical grooved cam for lens driving

A multifocal lens system to be used for digital cameras for setting any one of a plurality of lenses in a picture taking (image capturing) position comprising a wide-angle lens (shorter focal length lens) mounted in front of an image sensor in a picture taking (image capturing) position, a telephoto lens (longer focal length lens) mounted alongside the wide-angle lens, a parallelogram prism (rhombic prism) or a pair of triangular prisms removably arranged between the two lenses at the rear of them. When the wide-angle lens is to be used, the parallelogram prism or one of the two triangular prisms is to be removed from the rear of wide-angle lens so that the wide-angle lens can be focused on the sensor enabling light to pass therethrough. The telephoto lens is so positioned that it may be focused on the image sensor through the parallelogram prism or being reflected by the triangular prisms enabling light to pass therethrough when a part of the parallelogram prism or one of the two triangular prisms is placed in front of the image sensor to cover the imaging area of the sensor and to shut the light through the wide-angle lens to the sensor. By moving the prism from the rear of each lens, one of the two lenses can be positioned for picture taking (image capturing).

Multifocal lens system for digital cameras

An optical apparatus to be used for digital still cameras for setting any one of a plurality of lenses in a picture taking (image capturing) position comprising a lens turret rotatable around an axis and having the lenses mounted thereon, a driving mechanism to rotate the lens turret so that one of the lenses can be set at the picture taking position and a means to adjust and extend the back focal length of the lens shaped like a column or square column and made of glass, plastic or the like that has higher refraction index than that of air. By said means of back focal length adjustment, the position of the lens with shorter focal length can be fixed on the lens turret moving apart from the image sensor like CCD or C-MOS upward without changing its focal length itself, and fixed at the same level thereon as the lens with longer focal length. With this adjustment of back focal length, the lenses can be fixed on the turret as closely as possible with each other, yet any part of one lens does not cut in or disturb any part of light path of the other lens. Consequently the total size of lens turret could be minimized.

Lens turret with back focal length adjustment

A multifocal lens to be used for digital still cameras comprises a fixed first lens or a first group of lenses; a movable second lens or a second group of lenses; and a fixed third lens or a third group of lenses, wherein the second lens or second group of lenses moves back and forth (up and down) between the first and third lenses or lens groups, and changes its own focal length of the whole lens from wide angle to telephoto and vice versa.

Growing community of inventors

Kanagawa, Japan

Yoshio Yamazaki