The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 11, 1996
Filed:
Oct. 18, 1994
Nagayoshi Hirano, Ohmiya, JP;
Fuji Photo Optical Co., Ltd., , JP;
Abstract
An automatic visibility regulator for a camera viewfinder includes a focusing detector system that is adapted to detecting whether or not an object image to be photographed, having passed through the viewfinder, is focused on the retina of the user's eyeball and a focal position shifting device adapted to shifting a focal position of an ocular system and thereby to shift a position at which the object image is focused. The focal position shifting device is actuated to shift the ocular system when the focusing detector system detects that the object image is not focused on the retina of the user's eyeball. The focal position shifting device is not actuated, and, consequently, the focal position of the ocular system is not changed, when the focusing detector system detects that the object image is focused on the retina. The focusing detector system includes a combination of a photo projector and a photodetector, wherein a beam of light projected from the projector passes through the ocular system and is reflected on the retina of the user's eyeball. The beam of light passes again through the ocular system and is received by the photodetector. Properties of the received beam of light determine whether or not the object image is focused on the retina. If it is determined that the object image is not focused on the retina, the focal position shifting device is actuated to shift the focal position of the ocular system until the object image is focused on the retina. In this manner, visibility is automatically adjusted to an appropriate value without any adjustment operation by user.