초록 ▼

This invention is directed to a rangefinding system which includes a light beam source, a plurality of light receiving elements disposed to receive an image light spot reflected from a target object existing in any one of a group of distance zones in such manner that the image light spot is projecte

This invention is directed to a rangefinding system which includes a light beam source, a plurality of light receiving elements disposed to receive an image light spot reflected from a target object existing in any one of a group of distance zones in such manner that the image light spot is projected on one or more of the light receiving elements, the light receiving elements being adapted to produce a combination of outputs, the contents of which vary depending on the distance between the target object and the rangefinding system the invention also includes a logic circuit for producing signals indicating the distance zone in which the target object exists, the signal generated in response to the combination of outputs, so that the space occupied by the light receiving elements can be advantageously decreased and the precision of rangefinding can be improved.

대표청구항 ▼

A device for automatically adjusting the focus setting of an objective lens, said device comprising: (a) a light beam emitter for emitting a light beam; (b) an exit means for projecting said light beam emitted from said light beam emitter toward a target object located within a distance range consis

A device for automatically adjusting the focus setting of an objective lens, said device comprising: (a) a light beam emitter for emitting a light beam; (b) an exit means for projecting said light beam emitted from said light beam emitter toward a target object located within a distance range consisting of a plurality of distance zones; (c) an entrance means for receiving a light beam reflected from said target object, said entrance means disposed at a predetermined distance from said exit means such that said reflected light beam is adapted to pass through said entrance means at an angle with respect to the emitted light beam whose value is dependent upon the distance between said target object and said device, said reflecting light beam projecting an image light spot representative of said target object; (d) a plurality of light receiving elements for generating an output in response to light impinging thereon, said plurality of elements disposed behind said entrance means for receiving said image light spot, said plurality of elements spaced a predetermined distance from each other and arranged in a row, wherein said image light spot impinges on at least one of said light receiving elements, the location of the impinging of said image light spot varying in accordance with the distance zone within which said target object is located, whereby said light receiving elements generate a combination of outputs; (e) a logic circuit for receiving said combination of outputs from said plurality of light receiving elements and for generating a signal representative of said distance zone within which said target object is located, said signal generated by said logic circuit in accordance with said combination of outputs from said plurality of light receiving elements; (f) means for shifting said objective lens along the optical axis thereof for focus adjustment; (g) an arresting means for arresting said objective lens shifting means; (h) trigger means for actuating said objective lens shifting means; and (i) means for actuating said arresting means in response to said signal generated by said logic circuit when said objective lens is set to a position corresponding to said distance zone within which said target object exists, said actuating means including a detector for detecting the position of said objective lens and generating actuating signals when said objective lens is brought into focus at one of said distance zones by the actuation of said objective lens shifting means, and a control circuit for comparing said actuating signals with said signal generated by said logic circuit and for actuating said arresting means upon the generation of the one of said actuating signals representing that said objective lens has been brought into focus at said distance zone represented by said signal generated by said logic circuit, whereby said objective lens is focused at said distance zone wherein said target object is located.