US 4,594,788 A · Light-tight combination micrographic map-reader protractor compass

Abstract

A movable film cartridge with at least one view superimposed by a protractor image on transparent film is further provided with a compass viewed through a prism at an edge of the field of view of the film containing a map or aerial view image. A double spool cartridge contains the film and moves the film from one spool to the other reversibly by a hand-turned knob or motor. The cartridge moves vertically within the light-tight casing housing the cartridge. An eyepiece with a sealed double flap opens for viewing with the eyepiece tightly sealed against the face of a user. A button operated by the user's nose or bridge of the nose turns the interior light on for light-tight viewing. Magnified viewing of the microphotographic film may be through a single lens in a wrist mounted embodiment or through a double viewing system for stereo vision with images recorded from two different perspectives separated by the distance between the eyes of the user. Additional information may be recorded on the frames between the stereo images on the film. Vials of acid mounted interiorly may be broken for film destruction in security tight situations. A light-weight plastic casing and lens system alternately uses film mounted on circular discs. Both cartridges and discs are replaceable in the casings.

Claims19

Dependent claims

A navigational aid combining a self-illuminated stereo micro-photographic map reader, a direction finder compass and a distance measuring protractor in one self-contained light-tight portable compartment, wherein the navigational aid comprises:

a completely opaque casing with spaced viewing openings for two eyes of a user, wherein each viewing opening seals tight around each eye of the user while viewing emitting no light outside of the eyes of the viewer so that total light control is maintained;
aligned with each viewing opening, a microphotographic reproduction of a landform, wherein each reproduction is taken from a perspective separated from the other reproduction by an average distance between two pupils of the eyes of a human;
a self-powered internal source of light for illuminating the micro-photographic reproduction within the casing for viewing the reproduction and a means for activating and deactivating the light;
a lens means for equally magnifying both reproductions when seen through the eyes of the user;
at least one compass means of establishing direction viewable through at least one of the viewing openings simultaneously with viewing the reproduction;
at least one protractor means of measuring the reproduction in relative scale, which protractor means is viewable through at least one of the viewing openings simultaneously with the reproduction, wherein the protractor appears to overlay the reproduction;
a translucent panel behind the reproduction, which panel is normally closed to outside light by a shutter, which shutter may be opened to admit external light into the casing to illuminate the reproductions for viewing.

4 more elements

A navigational aid combining a self-illuminated microphotographic map reader, a direction finding compass and a distance measuring protractor in one self-contained light-tight portable compartment, wherein the navigational aid comprises:

a completely opaque casing with at least one viewing opening for an eye of a user, wherein the viewing opening contacts the face of the user around the eye, having a flexible rubberized gasket which surrounds the eye of the user, wherein the gasket comprises an enclosed cup tightly attached to the casing and the outer portion of the cup comprises an opening slit which is normally closed, which slit is forced open by an outer flange flared open by pressure from the user's face;
aligned with the viewing opening, a microphotographic reproduction of a landform;
a self-powered internal source of light for illuminating the microphotographic reproduction within the casing for viewing the reproduction and a means for activating and deactivating the light;
a lens means for magnifying the reproduction when seen through an eye of a user;
a compass means of establishing direction viewable through the viewing opening simultaneously with viewing the reproduction;
a protractor means of measuring the reproduction in relative scale, which protractor means if viewable through the viewing opening simultaneously with the reproduction and appearing to overlie the reproduction;
and
wherein the casing is mounted on a band and worn around a wrist of the user.

5 more elements

Dependencies are inferred from the claim text.

Light-tight combination micrographic map-reader protractor compass

Life of this patent

Light-tight combination micrographic map-reader protractor compass

Life of this patent

Abstract

Claims19