US2846799A - Display devices - Google Patents

Description

gauge Alig- 12, 1958 N. vlszLocKY ETAL DISPLAY DEVICES SPIDER FIGQB INVENTORS NICHOLAS VISZLOCKY STEVEN VlSZLOCKY ATTORNEY Lamu Unit/eid States Patent O ice 2,846,799

DISPLAY DEVICES Nicholas Viszlocky and Steven Viszlocky, New York, N. Y.

Application September 18, 1953, Serial No. 381,018

3 lClaims. (Cl. 40-130) This invention relates to display devices utilizing polarized light and its effects; more particularly it relates to devices of such type wherein changeable images and colors are visible to the observer.

An object of the invention is to provide an improved display device of this character wherein it will be possible for an observer to see novel decorative color changes caused by changing polarized light played upon v a birefringent material.

A further object of the invention is to provide a display device of this character capable of producing the optical effects ordinarily attained by multiple bulbs set in complex circuits with liashers.

Still a further object of this invention is to provide improved images for display devices of this character.

To the accomplishment of the foregoing and such other objects as may hereinafter appear, this invention consists in the novel construction and arrangement of parts hereinafter to be described in detail and then sought to be defined in the appended claims, reference being had to the accompanying drawings forming a part hereof which show, merely for the purposes of illustration, preferred embodiments of the invention, it being expressly understood, however, that changes may be made in practice within the scope of the claims without digressing from the inventive concepts.

In the drawings in which similar reference characters denote corresponding parts:

Figure 1 is a vertical section of a display device constructed according to the principles of this invention.

Figure 2 is a perspective view of one form of image and image support illustrating the details of its constructron.

Figure 3 is a plan view of another form of image and image support.

Figure 4 is an enlarged view showing a portion of the image illustrated in Figure 3.

Referring to the drawing, the display device has an opaque housing 12 surrounding and supporting the other component elements. For purposes of clarity, the brackets or other conventional means used for supporting purposes are omitted. Also omitted are means by which display device 10 may be hung from a wall or held in place on a shelf. The hollow interior of housing 12 is preferably circular. Attached to the sides of housing 12 by a bracket through posts 19 is a base compartment 13 which contains the electrical control elements for display device 10. Thus inside compartment 13 is a motor 14 whose shaft 16 extends through into housing 12. For ready access to the motor and other electrical elements, the end plate 15 may be removably attached to compartment 13. The starting button 17, motor switches, etc. can project out from end plate 15.

Attached to motor shaft 16 are a plurality of spider legs 18 which extend centrally past uorescent light 20 and the bracket to a translucent isotropic sheet 22. The spider legs 18 which attach to translucent sheet 22 at ...are v- Patented Aug. 12, 1958 sheet in place and make it rotatable. Co-extensive with translucent sheet 22 is a sheet 24 of light polarizing material such as Polaroid which has a fixed polarizing axis. The sheets 22 and 24 which may be united or laminated together in any suitable way, rotate as a unit when spider legs 18 are turned by motor 14 through shaft 16.

The light source, consisting of a toroidal fluorescent light 20 such as the Circline light or a tubular light of the neon type arranged in a coil, is supported inside housing 12 in any manner which leaves its central opening an unencumbered passage for the spider legs 18. For example, thelight can be clamped to the same bracket which supports compartment 13. The electrical connections for fluorescent light 20 lead out of compartment 13, with transformer 21 and starter button 17 for the light being housed inside compartment 13. As a constructional characteristic of display device 10, compartment 13 is smaller than the central opening of light 20 so that the light bulb may be inserted and removed without disturbing compartment 13 and its contents. The annular base 23 is removably bolted' or screwed to the rest of housing 12 to provide ready access to light 20 for its maintenance or replacement.

A particular advantage of the toroidal or tubular light (both of which are hereinafter called circular) lies in the large surface area for emission of high intensity light. A less preferred alternative light source comprises linear uorescent lights situated along the sides of housing 12 so as to leave an unencumbered central passage. Of course, lights so situated may be used in addition to the circular one, but ordinarily a single circular fluorescent light will provide sufficient illumination for display device 10. As a further advantage of the circular light source, placement of the light along a locus about midway between the center and the outer periphery of translucent sheet 22 facilitates uniform diffusion of light through the translucent sheet to polarizer 24 so that an observer looking at light 20 solely through supcrposed sheets 22, 24 would see a substantially uniform field of high intensity light issuing from sheet 24. In this connection there is some advantage to coating the interior surface portion of housing 12 lying behind light 20 with a light reflecting material.

Since the polarizing sheet 24 has a fixed polarizing axis, when motor 14 is energized to rotate its associated shaft 16 and spider legs 18 thereby rotating sheet 22, 24 in its plane before circular light 20, as viewed from open end of housing 12 the plane of polarization of the light passing through sheets 22, 24 is constantly changing direction.

At the open or viewing end of housing 12 a stationary analyzer sheet 26 of light polarizing material such as Polaroid is provided. This analyzer sheet 26 has a fixed polarizing axis and has substantially the same dimension as sheets 22, 24. An observer viewing the polarized light passing directly from rotating polarizer 24 to analyzer 26 would cyclicly sce the variations in light intensity so characteristic of crossing and uncrossing polarizers. The light would periodically go from minimum to maximum intensity. Interposition of an image 28 fashioned from a birefringent material such as regenerated cellulose or cellophane alters this pattern by its anisotropic effect. rl'he cyclic change in light intensity is transformed into a cyclic change in the color pattern of the image. These color changes are coupled with the aforementioned variation in actual light intensity, but this variation is ordinarily noted by the eye of an observer as phases of dull and bright colors.

A backing 30 may be placed behind image 28 for providing sufficient rigidity to make it self-supporting, and if image 28 is cellophane, backing 30 adds a desirable degree of fire resistance. Backing 30, which is of a suitable isotropic material may be joined to the birefringent image in any suitable manner, e. g. by an isotropic adhesive. In a preferred form of the invention both image 28 and backing 36 are recessed into an isotropic image support 32. As shown in Figure 2, stamped out cellophane image R may be simply dropped into a matching slot in image support 32 and a closely fitted backing piece (not shown) placed in the slot to sandwich the image between backing 30 and support 32. Cement may be applied to the lateral edge of backing 30 and/or the sides of the image slot in support 32. This construction provides a simple method of securing an increased image from thin segments of birelringent material. Generally support 32 and backing 30 will be of the same isotropic substance, but colorful effects may be obtained if one of them, preferably backing 30, is tinted. The optical effect caused by the edges of backing 30 and the slot in support 32 is small and may be further decreased by placing the assembled image in housing 12 with support 32 facing the viewing end as shown in Figure l.

The details of a type of image 28 productive of unusual optieal effects are shown in Figures 3 and 4. The image support 132 is an opaque or an isotropic translucent sheet having a set of perforations or apertures which form a desired pattern such as the numeral 8 of Figure 3. Underlying each aperture is a birefringent segment. Each segment may consist of one or more layers of birefringent material. Different optical effects are obtained according to the selection and orientation of the segments. Thus, as shown in Figure 4, the segments underlying apertures 34, 36, 38, 40, 42, 44 may be individually oriented with their significant axis or direction as shown by the arrows to an overall random pattern of orientation. Since each segment has its individual effect on the polarized light passing through its aperture as the plane of polarization changes with the rotation of polarizing sheet 24, individual apertures will grow brighter or darker as well as change in color. Since a random pattern of orientation was preselected, the image as a whole, i. e. the numeral 8, will appear to twinkle or pulsate in varying colors. Since the segments may be initially of different color tints as well as oriented in different directions, there is a tremendous amount of variation permissible within this single pulsating or twinkling effect.

By appropriate design of the pattern apertured in image support 132 and proper selection andorientation of the birefringent segments in each aperture, thereY may be attained many of the effects commonly secured by displays made of individual bulbs set in timed sequence. Thus by orienting the segments sequentially with, for example, a progressive 5 or 10 angular increase from a starting segment to its next adjacent segment on through all the segments, rotating the polarizer will cause the colors to travel or run around the numeral 8. With a double row of apertures as shown in Figure 3, the colors may go in one direction around one row and in the opposite direction around the other row. This travelling or running effect can be made more striking by having cellophane segments of one tint, e. g. pink in one row of apertures and a different tint, e. g. blue in the other row of apertures. Similarly other effects like that of expanding and contracting, ag-waving, revolving wheel, pyrotechnic, sunray, smoke and steam, may be obtained by such simple expedients as forming the appropriate designs with the apertures and selecting proper orientation for the birefringent segments.

Unique combination effects may be attained. For example the revolving wheel effect may be obtained by cyclicly blanking out sections of the image. Thus by positioning spaced apart pie shaped opaque sectors (not shown) just adjacent backing 30 and rotating them through suitable connection with motor 14 at the same or at a different rate than polarizing sheet 24 rotates, the sectors will cyclicly black out sufficient apertures to give the optical effect of revolving wheel spokes. Then if the apertures were of different tints randomly oriented, the revolving wheel would appear to pulsate or twinkle n many varying colors.

In operation of a display device having the apertured form of image illustrated by Figures 3 and 4, it is important to relate the rate of color change to the optical effect desired. Thus for the pulsating effect motor shaft 16 should rotate at a relatively rapid rate, e. g. 60 revolutions per minute. Generally speaking,V a minimum rate of.' 20 revolutions per minute is contemplated for all the effects attainable with the apertured image. This is in contrast to the form illustrated in Figure 2 for which 4 or 5 revolutions per minuteis satisfactory.

It is to be understood therefore that an infinite number of combinations of color flow and change of color in images of all conceivable shapes may be secured by suitably positioning birefringent materials in approximately apertured image supports like 132. The examples herein given of color flow and design combinations are illustrative only, and are in no sense to be regarded as limitations. Also, variation in the structural details are possible and are contemplated within the scope of the claims. There is no intention of limitation to the exact details shown and described.

What is claimed is:

l. An illustrated display device comprising: a housing: a motor compartment centrally located at the base of said housing; a motor in the compartment; a shaft rotatable by said motor extending from the compartment interiorly of said housing; a set of spider legs positioned on said shaft; a translucent light diffusing sheet rotatably supported adjacent the peripheral edge thereof by said spider legs; a circular fluorescent light spaced radially outward of said spider legs, the central opening of the circular uorescent light being wider than the motor compartment whereby said light may pass around said compartment upon removal through the base of the housing, said light being generally positioned to substantially uniformly illuminate the translucent diffusing sheet; a light polarizing sheet coextensive with said diffusing sheet and attached thereto for rotation therewith; a stationary birefringent image supported in said housing; and a stationary light polarizing sheet supported in said housing; said rotatable diffusing and polarizing sheets, said stationary birefringent image and said stationary polarizing sheet being in that order aligned in said housing between said light source and the eye of an observer whereby as said motor and spider legs turn said rotatable polarizing sheet the observer views variable color effects.

2. The apparatus of claim 1 wherein said image is disposed in a slotted image support and held there sandwiched between said image support and an isotropic backing, the surface of which matches that of said slotted image support.

3. The apparatus of claim 1 wherein said image comprises an image support having a design formed thereon by a plurality of apertures; and wherein each individual aperture has therein an individually oriented image segment of birefringent material whereby turning of said rotatable polarizing sheet individually effects a change in the color and intensity of the light passing through each aperture.

References Cited in the file of this patent UNITED STATES PATENTS 2,146,962 Land Feb. 14, 1939 2,261,957 Burehell Nov. ll, 1941 2,313,831 Martin Mar. 16. 1943

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