GB2541438A

GB2541438A - Open zoetrope device

Info

Publication number: GB2541438A
Application number: GB1514811.7A
Authority: GB
Inventors: Akinwale Latunde-Dada Kehinde
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-08-20
Filing date: 2015-08-20
Publication date: 2017-02-22
Also published as: GB201514811D0

Abstract

An optical device, in which a series of animated sequences of unlimited length is viewed, includes a stationary cylindrical drum 1 with a vertical opening 4 and equidistant slots 2 and a rotating cylindrical shutter drum 9 with corresponding slots. A crank handle 15 connected to pulleys imparts rotational motion to the drum 9 causing a picture band 3 fed from spool 5 to advance in the space between the drums by the action of the struts 13 on drum 9 upon the studs 21 on the picture band, while simultaneously opening and closing the view of the band through slots. Thus viewers looking at the picture band through the slots 2 observe an animated display of a non-repetitive nature and of a longer length unlike the traditional zoetrope.

Description

Open zoetrope device

This invention relates to a new type of zoetrope device for displaying a long series of animated sequences of a non-repetitive nature.

The zoetrope, a nineteenth century optical device invented by William Horner and patented by William E. Lincoln has long been an object of fascination amongst collectors and the general public alike. It operates by the well-known principle of persistence of vision actualized by rotating a cylindrical drum with a number of equidistant slots in its upper circumference through which a number of observers may view a cylindrical picture band containing a series of successive animated pictures placed around the bottom interior of the drum. However, the ordinary zoetrope as an animation device has a major limitation in that it is constrained to the reproduction of the continuous and repetitive animation of a finite number of individual frames i.e. the last picture frame on the picture band precedes the first picture frame forming a continuous series. This is because the length of the picture band and therefore the number of distinct sequential frames it can display is restricted by the circumferential length of the zoetrope drum within which it sits. Thus only a limited range of animated movement is observable.

The present invention eliminates this constraint, by means of a device which displays a longer length of picture band with an unlimited length of picture frames whilst operating with the same principles as the simple repetitive zoetrope. This design consists of two rather than one cylindrical drum; a rotating shutter drum of special construction sitting inside a stationary drum with corresponding vertical slots cut out in their upper circumferences. By making a vertical opening in the stationary drum through which a picture band may be fed from a spool bank in the gap between the two drums, motion is imparted to the picture band by rotating the shutter drum which also successively obscures and opens the view to the observer. Thus, a sequence of animated frames may be observed. This enables the operator to reproduce and observers to view a longer sequence of animated pictures of a non-repetitive nature such as an entire cartoon strip.

The invention will now be described by referring to the accompanying drawings:

Figure 1 shows the familiar repetitive zoetrope.

Figure 2 shows the arrangement for the invention.

Figure 3 shows the details of the shutter drum

Figure 4 shows a section through the device highlighting the engagement between the picture band and the shutter drum

In Figure 1, the familiar zoetrope features are shown. The cylindrical drum 1, the upper circumference of which contains an equidistant number of vertical slots 2 with a circular picture band 3 with an animated series arranged around its base. The drum can freely rotate around this base. In the present invention, the stationary drum 1 has a vertical opening 4 in its circumference through which the picture band is fed and removed as shown in Figure 2. On the upper part of the drum, a row of vertical slots 2 a picture frame width apart, is arranged at a height such that the band of pictures sitting at the base of the drum 1 can be viewed clearly without obstruction. Inserted within drum 1, with sufficient clearance to accommodate the picture band 3, is a second rotating drum 9 shown in detail in Figure 3. Drum 9 is made up of a shutter screen 12 and vertical struts 13 which act as part of the advancing mechanism for the picture band. The shutter screen 12 has an equivalent number of equidistant slots 14 to the slots 2 on drum 1 such that when it is enclosed by drum 1, the slots 14 and 2 coincide. The distance between vertical struts 13 is the width of a picture frame, so that the picture frames can clearly be seen between them. The drum 5 is free to rotate within the stationary drum 1 in both directions. A spool known henceforth as the feed spool 5 is situated close to one edge of the opening 4 whilst a second spool 7 known as the take-up spool is located at the opposite edge. The feed spool carries the picture reel 6 made with a plasticized or laminated material smooth enough (or with some lubrication) to slide along the face of the drum 1 without much friction. Upon the inside face of the band are a series of animated picture frames, with each successive frame picture slightly different from the preceding one such that the entire reel contains an animated series or a collection of such. Between each frame is inserted a stud 21 of sturdy metal or plastic material. A length of this band 3 is fed from the feed spool 5 into the space between the two drums 1 and 9 with the studs 21 are positioned just in advance and in connection with the vertical struts 13 of drum 9, such that when drum 9 is rotated, the picture band 3 is pulled along by the movement of the struts 13 as shown in Figure 4. Upon reaching the opening 4 at the other edge of the drum 1, the band is wound under tension upon the take-up spool 7 forming the take-up reel 8. To improve the quality of the animation viewed, the vertical struts 13 and studs 21 are made of solid transparent materials e.g. Perspex.

The take up spool 7 is connected by a grooved pulley wheel 10 and pulley band 11 to the crank handle mechanism.

In its starting position, the slots of the device are open as shown in Figure 2; the slots of drums 1 and 9 are aligned and the picture band 3 can be clearly seen by an observer through the slots 2 and 14.

In the closed position, the slots of the device are closed; the drum 9 having been rotated slightly causing the slots 2 and 14 to be misaligned and thus the view of the observer is obscured.

The operation of the optical device is a follows:

In the starting position, a sufficient length of the picture band 3, a leader is threaded in the space between the two drums 1 and 9 from the feed spool 5 and wound upon the take-up spool 7. The stud projections 21 on the picture band 3 between the two drums are aligned just in advance of the vertical struts 13 on drum 9. When the drum 9 is rotated, the vertical struts 13 acting upon the studs 15 pull the picture band along from the feed spool round the circumference of the drums to the take-up spool simultaneously obscuring and opening the slots 2 and 14. The view of the observer looking through a slot is of the picture band advanced by a frame each time the slots are opened and thus the animation represented on the picture band is reproduced by the principles of persistence of vision. As the picture band exits the drums on the edge of drum 1, the vertical strut on drum 9 is disengaged from the stud 21 and carries on rotating to engage with the next frame at the other edge fed from the feed spool.

It may be desirable to constrain the view through the slits of the observer to only one picture frame. This is done using a masking strip shown in Figure 5 with a cut-out 22 the size of a picture frame. This is inserted in front of the picture band 3 in the interior of the drum masking all but one of the picture frames through which a single animated sequence can be viewed.

The device is operated by continuously revolving the crank handle 15 shown in Figure 1. Connected to the crank disc 16 by friction gearing or bevel gears rotational motion is imparted to a grooved pulley 17 connected to the take-up spool 7 via a pulley band 11 and pulley wheel 10. A second concentric pulley 18 drives the rotation of drum 9 by engaging with the grooved pulley 19 via a second pulley band 20. Turning the crank handle 15, imparts motion to a crank disc 16 which drives both the take-up spool 7 and the drum 9 at the same rate enabling the picture band 3 to be taken up on the reel 8 at the same speed as it is driven out of the drums. A third similar pulley system may be optionally applied to the feed spool 5.

Claims

1. An optical device comprising two cylindrical drums with equidistant vertical slots; one stationary drum with a vertical opening in its side enclosing a second shutter drum with vertical struts, a feed spool carrying a picture band with studs between each picture frame and a take up spool, in which motion is imparted to the picture band by the rotation of the shutter drum acting upon the picture band, advancing it while successively opening and closing the view of the band through the slots.

2. An optical device according to Claim 1 for displaying non-repetitive movements on a picture band of unlimited length in which an animated display is produced by rotating one cylindrical drum with equidistant vertical slots within another also with corresponding vertical slots, the two drums, the action of which simultaneously advances the picture band while successively opening and closing the view of the band through the slots.

3. An optical device for displaying non-repetitive movements on a picture band of unlimited length in which an animated display is produced by the action of a shutter device which simultaneously advances a picture band while successively opening and closing the view of the band to an observer.