Rotatable Strobascopic Toy

Abstract

A strobascopic light source and a rotatable toy to create exciting optical illusions as to the toy's rotational or lateral motion. Light emitting diodes placed on the periphery of a resilient aerodynamic disc toy which is thrown from one player to another cooperate with a multivibrator type electronic drive circuit, to create an unusual strobascopic effect.

Description

SUMMARY OF THE INVENTION

This invention relates in general to a novel application of a strobascopic light source to rotatable toys. This combination creates novel optical illusions regarding the lateral and rotational movement of the toy and also allows the toy to be used at night. Specifically, this invention is applied to an aerodynamic inverted cup-shaped disc which is thrown between two or more players and commonly referred to as a "Frisbee". The disc gains its flight stability from rotational motion. This application involves the placing of intermittent light emitting sources on or near the periphery of the disc. The interval and duration of the light pulse is controlled by an adjustable electronic drive circuit.

It is an object of this invention to provide for the use of rotatable toys, such as aerodynamic discs during the nighttime.

It is another object of this invention to create a number of optical illusions regarding the lateral and rotational movement of a rotatable toy. This will add an exciting new dimension to the sport.

Further objects, features and advantages of this invention will become apparent from a consideration of the following description, the appended claims, and the accompanying drawing in which:

FIG. 1 is a perspective view of the aerodynamic disc of this invention;

FIG. 2 is a cross sectional view through the center of the disc showing the relative positions of the drive circuit and the light emitting diodes;

FIG. 3 is a fragmentary view of the edge of the disc showing the position of the light emitting diodes;

FIG. 4 is an illustration of the comet tail effect produced by the combined effect of the rotational motion of the disc and the current-time profile;

FIG. 5 is a graph illustration of the current time profile; and

FIG. 6 is a schematic diagram of the electronic circuit which drives the light emitting diodes in the apparatus of this invention.

Referring now to the drawings, the rotatable toy of this invention is a shallow inverted cup-shaped disc 10 (FIG. 1) typically having a diameter of about eight inches, although this is not a critical dimension. A common example of this toy is manufactured by the Wham-O Corporation, and is marketed under the trademark FRISBEE. Such toys are thrown in free flight between players who send the disc through any number of flight patterns.

The inverted cup-shaped disc 10 includes a circular body member 11 having a central recess 12 and a downturned peripheral flange 13. The flange 13 provides the disc 10 with aerodynamic stability, and in addition functions as the portion of the disc 10 which is gripped by a player in propelling the disc 10 through the air with an initial wrist motion that rotates the disc. Typically, the disc 10 spins fastest at the beginning of the throw and then slows down gradually.

Two sets, or groups, of three light emitting diodes 14, a left side set 17 and a right side set 19, are mounted in diametrically opposite portions of the flange 13. The diodes are connected by leads 15 to a drive or control circuit 16, the major components of which are disposed in the recess 12.

As shown in FIG. 3, the diodes 14 in each set are arranged in a linear array of three, which is perpendicular to the plane of the body member 11. The diodes are preferably gallium arsenide phosphide light emitting diodes (L.E.D.) which emit photons at a wave length of 6700 Angstrom units (red), as a forward bias is applied, and places the P-N junction in a conducting state. This provides a very intense point source light. Green, amber, or any color L.E.D. could be used, and there could be one color on one side and a different color on the other.

The drive circuit 16 includes a voltage source 20, preferably a six to nine volts DC battery, a capacitor 21 in parallel with battery 20, and a linear integrated circuit 22. The circuit 22 performs a multivibrator function and is commercially available from Signetics, 811 Arques Ave., Sunnyvale, California, as part number NE555V. The circuit 16 also includes an "on-off" switch 24 and two resistors 26 and 28 connected in series with a capacitor 30. The resistors 26 and 28 and the capacitor 30 cooperate with the multivibrator-type circuit 22 to generate a current wave form, and is applied to the two sets 17 and 19 of diodes 14. This wave form which is shown in FIG. 5, is comprised of positive and negative spikes which peak at 34, and exponentially decay to zero. During the positive spikes, one set 19 of diodes will be turned on by a forward bias and will emit light; the other set 17 will be turned off by a reverse bias. As the current passes through zero at point 36 and becomes negative, the emitting diodes 19 will be turned off by the reverse bias and the other set 17 will begin to emit in response to the forward bias.

The diodes 14 are connected to ground through a current limiting resistor 40. The resistor 28 is preferably, but does not have to be, adjustable to enable adjustment of the blink rate 37. For this reason, resistor 28 is shown in the drawing as a potentiometer. In a preferred embodiment of the invention the blink rate is about 22 H.sub.z and in this embodiment the resistors 26 and 28 have values of 10,000 ohms and 3.3 megohms, respectively, and capacitor 30, has a capacitance of 0.01 microfarads. The capacitor 21 is 25 microfarads, the capacitor 32 has a capacitance of 220 microfarads and the resistor 40 has a resistance of 5 ohms. The blink rate of 22H.sub.z is chosen because it has been found that the usual rate at which a thrown disc 10 spins is about 22 revolutions per second. When first thrown, the disc spins faster than 22 r.p.s., midway in its flight it is about this rate and at the end of the flight it is less.

When the thrown disc 10 is viewed in free flight by the thrower, the blinking diodes 14 appear to be very intense lights rotating slowly in one direction. When the rate of rotation of the disc 10 slows down to about the 22 r.p.s. rate, the lights appear to move without rotation, and finally the lights appear to be rotating in the opposite direction. All of the above-described visual effects are due to the strobascopic effects caused by adjusting the diode blink rate so that it is approximately a whole number multiple of the disc rotation rate. The result is a very far out toy. It will be apparent to those skilled in the art that the same result can be achieved by locating the diodes 14 inwardly from the flange 13 and using fiber optics to transport light images to the flange 13. Also, more or less diodes 14 can be used in each group 17 or 19 and the color can be varied.

Claims

What is claimed is:

1. A toy comprising a disc having a downturned peripheral flange and adapted to be propelled through the air in free flight and concurrently rotated during at least a portion of said flight at a predetermined rate, light means in diametrically opposed portions of said flange, control circuit means mounted on said disc and connected to said light means, said circuit means being operable to turn said light means off and on at a frequency which is approximately a whole number multiple of said rate to thereby produce a strobascopic effect for a viewer of said disc during free flight thereof, said control circuit means including means for generating light pulses spaced apart at time intervals, and means determining said time intervals, said control circuit means providing for a voltage-time relationship for each diode in which the voltage falls off exponentially from a peak so that the light from each diode appears to go out quickly concurrently with rotation of the light during free flight of the disc to thereby give the impression of a comet-type light pattern.