Folded Stereoscope

This invention relates to a stereoscope, more particularly, improvements in the stereoscope disclosed in the Japanese Utility Model Publication 22276/1977.

Many stereoscopes including folded stereoscopes have been proposed. In one conventional type, the folded stereoscope is assembled into a box shape and in another, the stereoscope has portions which require paste for connection between the portions as disclosed the above mentioned Japanese Utility Model Publication 22276/1977. In these folded stereoscope, production must be done manually due to the difficulty in automation of mass production. Consequently, the cost of manufacture is high. Further, the body of these conventional stereoscope occupies much space and cannot be easily put into a flat configuration when folded.

It is, therefore, a main object of the invention to provide a very simple folded stereoscope which can be readily manufactured at low cost and is convenient to carry.

Another object of the invention is to provide a folded stereoscope which is made of a single sheet of material provided with a few fold lines and a few cut away portions and which can be readily assembled and disassembled.

A further object of the invention is to provide a stereoscope which occupies less space when folded.

A further object of the invention is to provide a stereoscope in which a partition wall can be accurately set perpendicular to and between photographs for stereoscopic viewing in order to give a good stereoscopic image to the viewer.

In accordance with the present invention there is provided a folded stereoscope which comprises a relatively rigid sheet of material generally in the form of a rectangle provided with a cut away portion cut from one side edge thereof, the sheet comprising an upper flap portion provided with two apertures spaced at a distance substantially equal to the distance between human eyes, each of said apertures being provided with a lens, a first lower flap portion connected to said upper flap portion through a first fold line and a second lower flap portion connected to said first lower flap portion through a second fold line and separated from said upper flap portion by said cut away portion.

The invention will be now explained with reference to the accompanying drawings.

FIG. 1 shows a plan view of one embodiment of a sheet for use in a stereoscope according to the present invention before assembly,

FIG. 2 shows a perspective view of a sheet assembled into a stereoscope,

FIG. 3 shows a plan view of another embodiment of a sheet similar to that of FIG. 1, and

FIG. 4 shows a perspective view of a sheet assembled into a stereoscope similar to that of FIG. 2.

Referring now to FIGS. 1 and 3, a sheet 1 which is to be assembled into a stereoscope 20 as shown in FIGS. 2 and 4, hereinafter described in more detail is preferably made of a relatively rigid synthetic resin sheet or card board which permits thin fold lines to be made on its surface easily.

The sheet 1 is generally in the form of a rectangle and is provided with a cut away portion 6. A laterally extending fold line 9 and a longitudinally extending fold line 10 are provided on the sheet 1 for forming an upper flap portion 3, a lower flap portion 8 or 8' and another flap portion 7 as shown in FIGS. 1 and 3.

More particularly, the cut away portion 6 is provided on the sheet 1 by cutting out a portion from one side thereof (the left side as shown in FIGS. 1 and 3) substantially in the central area thereof. The lower flap portion 8 or 8' is connected to the upper flap portion 3 through the fold line 9 which extends laterally from the portion of the cut away portion 6 toward one side edge of the sheet 1 (the right side edge as shown in FIGS. 1 and 3). The other lower flap portion 7 is connected to the lower flap portion 8 or 8' through the fold line 10 which extends longitudinally from the edge adjacent the cut away portion 6 toward the bottom edge of the plate 1, but is separated from the upper flap portion 3 by the cut away portion 6.

The upper flap portion 3 is provided with two apertures 2 spaced from each other at a distance substantially equal to the distance between the eyes of the viewer. A lens 4 held in a frame 5 is removably fitted in each aperture 2. The aperture 2 is preferably constructed in an elliptical or flattened elliptical form so as to permit the lenses to move slightly for adjustment of the distance between them to the viewer's eyes.

The upper flap portion 3 may be formed with a top flap portion 11 by providing a fold line 16 laterally extending between the opposite side edges of the plate 1, between the flap portions 3 and 11. The top flap portion 11 is provided with an elongated cut-out 12. The cut-out 12 functions to frictionally and resiliently clamp the edge 17 provided on the lower flap portion 7 therebetween, when the stereoscope is assembled. The edge 17 is formed by cutting a small rectangular area from the top side corner of the flap portion 7. When the stereoscope 20 is assembled as shown in FIGS. 2 and 4, the lower flap portion 7 serves as a partition wall which separates the left and right stereoscopic photographs with regard to the viewer's eyes. The above-mentioned construction imparts stability and strength to the assembled stereoscope.

The cut-away portion 6 may be formed to accommodated the viewer's nose by enlarging its central portion such as by the provision of a trapezoid portion 13 and a triangle or trapezoid portion 14.

In the embodiment shown in FIGS. 1 and 2, a fold line 15 is provided on the flap portion 8, laterally extending from the portion of the cut away portion 6 toward one side edge of the sheet 1 parallel to the fold line 9. The fold line 15 allows the flap portion 8 to be bent at the fold line 15 when assembled.

In the other embodiment shown in FIGS. 3 and 4, there is no fold line provided on the flap portion 8' and, therefore, the flap portion 8' itself is not bent when assembled.

In assembling the stereoscope, the flap portion 7 is bent or folded at right angles relative to the flap portion 8 or 8' to form legs of the stereoscope therewith. In case of the embodiment shown in FIGS. 1 and 2, after bending of the flap portion 7 to the flap portion 8 the flap portion 8 itself is slightly bent at the fold line 15 and thereafter, bent or folded at substantially right angles relative to the upper flap portion 3 at the fold line 9. In case of the embodiment shown in FIGS. 3 and 4, just after bending of the flap portion 7 to the flap portion 8', the flap portion 8' is folded relative to the upper flap portion 3.

Where the top flap portion 11 together with the cut-out 12 is provided on the upper flap portion 3, the flap portion 11 is folded relative to the upper flap portion 3 and then the edge 17 of the lower flap portion 7 is fitted into the cut-out 12 and frictionally and resiliently held therein to ensure that the assembled stereoscope 20 is rigidly constructed as shown in FIG. 2 or 4.

In use, the assembled stereoscope 20 is placed on the stereoscopic photographs, not shown, so that the lower flap portion 7 is positioned between and perpendicular to the stereoscopic photographs. Thereafter, when the viewer looks at the stereoscopic photographs through the lenses 4 with his nose placed in the cut-away portions 13 and 14, he is able to view a stereoscopic image.