Animated Display

Abstract

An animated display assembly for an advertising sign or decorative display. A plurality of overlapping, axially separated polarizing disks are rotatably mounted between a stationary display panel and a light source. A drive motor is connected to the disks through a train of couplings and gears to rotate the disks in synchronism. Stationary polarizing sheets in various orientations are secured to the display panel, and the stationary sheets coact with the synchronously rotating disks to impart an animation effect to letters, symbols, or other markings on the display panel.

Description

BACKGROUND OF THE INVENTION

There are several known styles of advertising signs and similar displays which achieve an animation or simulated-motion effect in words or symbols forming a displayed message. One effective way of achieving animation is disclosed in U.S. Pat. No. 3,054,204 - Yates, titled "Animation Illustrator". This patent relates to a display using a rotating polarizing disk between a light source and translucent display panel bearing stationary polarizing films of varying orientations.

This invention relates to a display assembly which is of a size and format requiring more than one polarizing disk. The invention includes a plurality of overlapping disks or support frames each carrying a polarizing film. A simple and economical drive system is used to rotate the several disks in synchronism to achieve the desired animation effect on a relatively large sign.

SUMMARY OF THE INVENTION

Briefly stated, the animated display assembly of this invention includes a hollow housing having at least one open face, and a light-transmitting display member is supported on the housing across the open face. The member has display markings thereon, and carries stationary light-polarizing members of varying orientations organized to impart an animation effect to the markings when the panel is illuminated with light of varying polarization.

A light-source means, such as a bank of parallel fluorescent lamps, is mounted within the cabinet to backlight the display member. A plurality of overlapping and axially separated movable light-polarizing members are movably supported in the housing between the light-source means and the display member. A drive means is mounted in the housing, and is connected to the movable polarization members for synchronously varying the orientation of the movable members whereby light illuminating the display member is of varying polarization.

Preferably, the movable light-polarizing members are circular disks, and the display member is a sheet of acrylic plastic. The drive means comprises a variable-speed electric motor connected to a plurality of gear boxes having shafts which, in turn, are secured to the disks.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation of an animated display assembly according to the invention;

FIG. 2 is a perspective view, partly broken away, of a portion of the assembly shown in FIG. 1;

FIG. 3 is a top sectional view of the display assembly;

FIG. 4 is a perspective view of a mechanical drive system for the display assembly;

FIG. 5 is a perspective view, partly broken away, of a gear box used in the mechanical drive; and

FIG. 6 is a schematic view of three overlapping polarizing disks used in the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1-3, an animated display assembly 10 according to the invention is shown in the form of an advertising sign suitable for mounting on a pole or on the top or facia of a building. Assembly 10 includes a hollow cabinet or housing 11 having an angle-iron frame 12, top and bottom metal closure panels 13 and 14 and metal side closure panels 15. The housing is supported on a conventional rigid pole or mast 16 secured to a cross member 17 which is centrally positioned in and anchored to frame 12. A flange 18 at the base of the mast enables the assembly to be secured to a pole, building or other supporting structure.

The open front and back faces of housing 11 are closed by acrylic-plastic display members or panels 20 and 21 which are held in place by trim frames 22 secured to the housing. Panels 20 and 21 are transparent or translucent acrylic plastic sheets which are spray painted or pigmented to display an advertising message (as exemplified by the word "sign" in FIG. 1). An animation effect is achieved in the advertising display by adding differently oriented portions of sheet polarizing material to panels 20 and 21 in accordance with the disclosure in the aforementioned U.S. Pat. No. 3,054,204.

For example, in FIG. 1, each letter 25 of the word "sign" is subdivided into an inner zone 26, middle zone 27, and outer zone 28. An overlay of polarizing sheet material is cut to match the contours of each zone, and is glued or otherwise secured to the inner faces of panels 20 and 21 in alignment with the respective zone.

The polarizing axes of the several side-by-side overlays are arranged in different orientations as indicated by arrows 29 in FIG. 1. A background space 30 surrounding the letters has a polarizing overlay oriented the same as the overlay on inner zone 26, and a border space 31 also has a polarizing overlay oriented in alignment with the polarization axes of the overlays on middle zone 27 of the letters.

The use of differently oriented segments or overlays of polarizing material to achieve an animation effect is well known, and is described in greater detail in the aforementioned U.S. Pat. No. 3,054,204, and patents cited therein. Many other arrangements and orientations of polarized display markings are of course possible. Polarization-vector orientations are determined during design of the advertising display, and the overlays are permanently secured to panels 20 and 21 to be a stationary part of the panels.

A plurality of fluorescent lamps 34 are spaced along the interior of housing 11 and supported in sockets 35. Power for the lamps is supplied through a line 36 extending from a power junction box 37 mounted on side panel 15, and power to the junction box is in turn supplied by an external power cable 38.

A variable-speed, right-angle-drive motor 40 is secured at one end of cross member 17 (FIGS. 2 and 3). The right-angle drive is preferred as it permits the motor to be mounted compactly at the side of the sign housing where it offers minimum shadowing and interference with light transmission in the housing. Conventional speed-control circuitry for the drive motor is housed in a box 41 on side panel 15 above the motor. A variable-speed motor is preferred so an animation rate appropriate to a particular display can be established without difficulty. Power cables 42 provide electrical power from junction box 37 to the speed-control circuitry and drive motor.

A plurality of right-angle-drive gear boxes 45 are secured to cross member 17, and are evenly spaced apart within housing 11. Each gear box 45 includes an input shaft 46 and a cross shaft 47. An output shaft 48 is also provided if the gear box is to drive another downstream gear box. The shafts are journaled through conventional bearings 49 secured to gear box 45.

Each shaft has a beveled gear 50 rigidly secured thereto, and the gears are meshed so the rotation of the input shaft is transmitted to the cross shaft and output shaft. The opposite ends 51 of cross shaft 47 are reduced in diameter and threaded, and an enlarged flange 52 is positioned at the base of each threaded section.

As best seen in FIG. 4, the several gear boxes of the display assembly are coupled through universal joints 55 to interconnecting drive shafts 56. A torque-limiting clutch 57 is provided on the output shaft of drive motor 40, and the clutch is connected to the first drive shaft in the train of components. The universal joints accommodate any misalignments in the system, and the clutch prevents motor damage in the event of a drive-system jam.

A disk 60 of transparent light-polarizing material is supported on a circular frame 61 formed by a rim portion 62 stiffened by cross members 63. Frame 61 is preferably formed of light-gage aluminum stock to provide a small and lightweight assembly which will not unduly shadow disk 60 or panels 20 or 21, or load the drive system. A plurality of these polarizing-disk assemblies are used in animated assembly 10, with one polarizing disk mounted at the end of each cross shaft 47 of the drive system between lamps 34 and an adjacent display panel 20 or 21. A central hub of frame 61 is slipped over threaded end 51 of the cross shaft against flange 52, and is secured in place by a threaded fastener 64.

As best seen in FIGS. 3 and 6, the lengths of cross shafts 47 are alternately varied to permit overlapping of adjacent disks 60. The lateral spacing of the several cross shafts is adjusted so the periphery of each disk is only slightly spaced from the cross shaft of the adjacent disk. In this manner, a simple and inexpensive drive system and group of polarizing disks are effective in covering a large rectangular surface of the display panels.

The polarizing film on each disk 60 has a polarization axis indicated by arrows 66 in FIG. 6. The disks are carefully aligned with the axes in parallel relation at the time frames 61 are secured to cross shafts 47, and the frames are locked in this orientation by fasteners 64. The disks will then be rotated synchronously by the mechanical drive system of the display assembly, and light illuminating the back surface of display panels 20 and 21 is of a uniform (but constantly changing) polarization.

As the disks are rotated by the drive system, animated letters 25 appear to "bloom" in synchronism with intensity variations in background and border spaces 30 and 31. Other kinds of animation effects such as linear motion are also easily achieved by orienting the stationary polarizing media on panels 20 and 21 in the fashion disclosed in U.S. Pat. No. 3,054,204.

The interior surfaces of the panels forming housing 11 are painted flat black to reduce stray light reflection within the housing which could interfere with the animation effect produced by the assembly. Similarly, the end portions of lamps 34 which are not directly behind disks 60 are blacked out (black black-out paint used on neon signs is satisfactory for this purpose) as shown in FIG. 6 to avoid dilution or washing out of the animation effect by stray light. Other components (such as boxes 37 and 41) which are mounted in the housing outside the desired light path (which is within a space defined by projecting the outlines of disks 60 toward the lamps and normal to the planes of the disks) are also painted flat black for this purpose.

Display assembly 10 has been described as a double-face advertising sign, but the drive system and polarizing-disk orientation herein disclosed are equally applicable to single-face displays. In either case, the mechanism herein disclosed provides absolute synchronization and a dependable drive system with a minimum number of inexpensive components.

Claims

What is claimed is:

1. An animated display assembly comprising:

a hollow housing having an open face;

a light-transmitting display member supported on the housing across the open face, the member having display markings thereon, and bearing stationary light-polarizing members of varying orientations organized to impart an animation effect to the display markings when illuminated by light of varying polarization;

light-source means mounted within the cabinet to back light the display member;

a plurality of overlapping and axially separated light-polarizing members rotatably supported in the housing between the light-source means and the display member, the members having parallel axes of polarization and laterally spaced axes of rotation; and

drive means secured to the housing and connected to the movable light-polarizing members for continuously rotating and synchronously varying the orientation of the movable members whereby light which back illuminates the display member is of varying polarization.

2. The assembly defined in claim 1 in which the movable light-polarizing members are circular disks.

3. The assembly defined in claim 2 in which the drive means comprises a drive motor, a plurality of shafts secured to the respective movable light-polarizing disks, and a transmission means interconnecting the motor and shafts whereby the several disks are driven by a single motor.

4. The assembly defined in claim 3 in which the transmission means comprises a plurality of right-angle gear boxes connected to the respective shafts, the gear boxes being interconnected by universal joints, and a torque-limiting clutch connected between the motor and one of the gear boxes.

5. The assembly defined in claim 4 in which the drive motor is a variable-speed motor, the light-source means comprises a plurality of elongated and parallel spaced-apart lamps, and the display member is a sheet of acrylic plastic.

6. The assembly defined in claim 5 in which surfaces within the housing outside a direct light path from the lamps to the light-polarizing disks and display member are blackened to reduce stray light reflection within the housing, the direct light path being a space between the lamps and disks which is bounded by a projection of the disk outlines in a direction perpendicular to the disk surfaces.