Method And System For Personnel Control With Blinding Illumination

Abstract

Unruly personnel, e.g. rioters, are subjected to continuous low intensity illumination of one part of the visible spectrum, which is sufficient for identification purposes, simultaneously with flashes of high intensity light of a different part of the visible spectrum, the latter is sufficient to blind the eye temporarily to the low intensity illumination and cause movements to appear confused and chaotic in the flashing high intensity illumination, whereby the activity of the crowd is inhibited or arrested. Police equipped with goggles, which are transparent to the continuous low intensity illumination but opaque to the flashing high intensity illumination, can see adequately under such conditions to remove individual agitators.

Description

The invention described herein may be manufactured, used and licensed by or for the Government for governmental purposes without the payment to me of any royalty thereon.

BACKGROUND OF THE INVENTION

The present invention relates to a method and system for controlling unruly crowds of people by non-violent means.

Present methods for controlling people engaged in unlawful group activities, such as riots, involve the use of force, such as the intervention of armed policemen or soldiers, or the use of various means of incapacitation, such as tear gas, vomiting gas, and the like. Such violent methods are costly and inefficient and at times result in injury and even death to participants. An urgent need therefore exists for a method for controlling or restricting the behavior of unruly personnel, which is effective and non-violent and is not psychologically degrading as is the use of tear gas, cattle probes, etc.

SUMMARY OF THE INVENTION

Accordingly, it is a principal object of the present invention to provide a method, and system therefor, suitable for controlling rioting crowds, etc., which is non-violent, quick and effective. Other objects and advantages will become apparent from the description of the invention.

In accordance with this invention, there is provided an effective, economical and non-violent method for crowd control as well as a system therefor, which utilize a combination of illumination and optical viewing means. The illumination includes a continuous low intensity light together with a high-intensity flashing light to temporarily, "blind" the human eye. Under these conditions, police equipped with optical filter means, e.g. goggles, which selectively cut out, and thereby protect their eyes against, the "blinding" flashing light, can enter the crowd and remove individual agitators with a minimum of force and risk of injury to persons or property.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a view of the illumination system of this invention being utilized by police to control a street riot.

FIG. 2 shows the spectral transmission curves for light filters suitable for use in the present invention.

DETAILED DESCRIPTION OF THE INVENTION

More specifically, this invention provides a novel method and system for personnel control, which comprises two emission sources of illumination, such as a searchlight or floodlight, in combination with an optical filter. The two sources of illumination may be separate or combined, as in a twin beam emission source. One of these emission sources provides a low intensity, continuous illumination in the area of interest, which is adequate for identification purposes and is composed of light of only a part, preferably a narrow part, of the visible spectrum. The other illumination source provides flashes, i.e. brief periods, of light of very high intensity and of a different part of the visible spectrum at a suitable regular or random frequency. The optical filter, which may be in the form of goggles or transparent face shields worn by law enforcement personnel, is designed so that it cuts off the spectral wavelengths of the high intensity light but transmits the spectral wavelengths of the continuous, low intensity light with little spectral transmission loss.

FIG. 1 shows a night riot scene, wherein searchlights 10 and 11 are mounted on a police vehicle 12 and are directed at a crowd of rioters 13 by operator 14. Searchlight 10 provides continuous, low intensity illumination, which is sufficient for identification purposes. Searchlight 10 is of the incandescent tungsten filament type, and is fitted with a filter 15, which transmits light of only a narrow part of the visible spectrum. Searchlight 11 provides flashes of high intensity illumination and is fitted with a filter 16, which transmits only light of a different part of the visible spectrum from that emitted from searchlight 10 through filter 15. Operator 14 and police officers 17 are provided with goggles 18, which are opaque to the flashing high intensity illumination but transmit the continuous, low intensity illumination essentially completely.

When the high intensity light from searchlight 11 is flashed at suitable frequency, e.g. at 2 to 3 second intervals, the vision of the crowd 13 is temporarily blinded so that the eye cannot see in the low intensity illumination from searchlight 10, since it cannot accommodate to the ever changing level of illumination, whereby movements appear confused and chaotic. Under these conditions, the activities of the crowd, due to the fact that it is temporarily blinded and confused, become greatly restricted and possibly even immobilized. Law enforcement personnel 17 equipped with face goggles 18 are protected against the blinding effect of the flashing high intensity light but are still able to see in the low intensity continuous illumination, and therefore are able to move unhindered into the crowd.

The method and system of this invention can be effectively utilized under night and dusk conditions, when the level of daylight illumination is insufficient to interfere with the efficient operation of the invention. When the invention is utilized to control crowds in city streets, etc. illuminated with artificial light from conventional sources, e.g. tungsten bulb, mercury vapor lamp, etc. such lighting is preferably turned off; or if necessary, it can be reduced to a level where it either does not interfere or is utilized as the continuous low level illumination in the system and method of this invention.

Thus, this invention provides a number of important advantages and advances in the art of controlling riots and related situations, for example:

1. It is not physically injurious to anyone, including rioters, innocent bystanders and police.

2. It is not psychologically degrading or immoral, such as is the use of gases, cattle probes, etc.

3. It minimizes the amount of police force required as well as the extent of injury to persons and property.

4. It is effective and economical.

5. It can be deployed and utilized in a short time. The searchlights can be mounted permanently on a vehicle and utilized quickly and effectively in a trouble area.

In a particular embodiment of the present invention, the high intensity flashing light was provided by a xenon vapor flash lamp with a Number 4-96 Corning glass filter. The continuous, low intensity illumination was provided by a standard tungsten bulb with a Number 2-64 Corning glass filter. The protective goggles were fabricated from Number 2-58 Corning glass filters.

The spectral transmission characteristics of these filters are set forth in the drawing. Thus, filter No. 4-96, used with the flashing xenon vapor lamp, transmits light of wavelength between about 300 and 600 millimicrons, the per cent transmission rising to a maximum of 80 percent at 500 millimicrons, and cuts off light of wavelength above about 605 millimicrons. Filter No. 2-64, used with the tungsten lamp, transmits about 80 percent of light of wavelength 680 millimicrons or higher and none of wavelengths below about 640 millimicrons. Filter No. 2-58, used in the goggles, cuts off wavelengths of light below about 615 millimicrons and transmits higher wavelengths, the percent transmission rising to about 90 percent for wavelengths of about 680 millimicrons and above.

Accordingly, in the particular system described above the goggles almost completely transmitted the continuous low intensity illumination and completely cut off the flashing high intensity light.

The aforesaid embodiment was found to be effective when tested on personnel in a dark room, wherein the continuous illumination from the tungsten lamp was about 0.01 ft-candles and the high intensity illumination peak illumination was about 200,000 ft-candles flashed at intervals of 2 to 3 seconds, the duration of the flashes being approximately 0.0005 second.

I wish it to be understood that I do not desire to be limited to the exact detail of construction shown and described for obvious modification will occur to a person skilled in the art.

Claims

I claim:

1. An illuminating system for use in control of unruly personnel, which comprises in combination:

means for subjecting said personnel to continuous, low-intensity illumination, adequate for identification, with light of a part of the visible spectrum;

means for subjecting said personnel to flashes of high intensity illumination with light of a different part of the visible spectrum; and

viewing means transparent to the light of said low intensity illumination but opaque to the light of said high intensity illumination.

2. A method for controlling unruly personnel, which comprises subjecting said personnel to continuous low intensity illumination, adequate for identification, by means of light of a part of the visible spectrum simultaneously with flashes of high intensity illumination with light of a different part of the visible spectrum than said low intensity illumination, wherein the flashes of said high intensity illumination occur with such frequency and intensity that the naked eye is blinded to the low level illumination and is unable to accommodate to the ever changing light level, whereby movements appear confused and chaotic, and viewing said personnel through a filter capable of transmitting the spectral wavelength of the low intensity illumination but incapable of transmitting the spectral wavelength of the high intensity illumination, thereby protecting the viewer against the blinding and confusing effect of the flashing high intensity illumination.