Abstract: An active infra-red surveillance illuminator uses a statistically mono-directional micro-diffractive material overlaid on a bank of light emitting diodes (LEDs) to refract light from the LEDs onto a target image. This delivers energy distribution profiles out to a distance to match the aspect ratios of current wide-angle target and wide-angle camera surveillance systems. The distribution of refracted light is elliptical. This distribution can vary by using different diffractive material in conjunction with various numbers, brightness and angles of the LEDs in an LED bank. The effective range of the illuminators is greatly extended with this type of illumination. By limiting infrared (IR) radiation down to a 10 degree vertical window it renders the IR illumination much more effective for surveillance imaging by providing much more effective power on wide, ground-level scenes, and particularly enables multi-lane license plate capture.

Abstract: This system provides a wide range of smooth and precisely controlled low and high speeds for pan-tilt-zoom surveillance cameras, in which a brushless motor is controlled by a Microcontroller in a low speed mode by sinusoidal synchronous commutation, in a high speed mode by block commutation, and in a transition phase from the low speed mode to the high speed mode by modulating integrated pulse-width modulation (PWM) square waves with sine waves. PID and lookup table registers are used by a microcontroller for a smooth transition from high speed mode to low speed mode, and from low speed mode to high speed mode, phase locking a sine position during transitions, in order to give a surveillance camera an ability to quickly move from one target to another at up to 100 degrees per second yet track objects that are moving very slowly.

Abstract: The present invention is an illuminator for CCTV surveillance and security applications that maintains constant optical output from an array of LEDs by employing output compensation, feedback and enhancement. This constant optical output illuminator system enables reliable long-duration low-light imaging and data capture for surveillance and security applications, via an array of LEDs, LED power supply circuitry, and output feedback and compensation circuitry in which a photodetector circuit provides a voltage signal proportional to an amount of light falling on a photosensor and the voltage signal is fed to a drive control circuit for electrical current to the LEDs to achieve a desired optical output as measured by a photosensor voltage setpoint across the photodetector circuit.

Abstract: A surveillance system having two specialized surveillance cameras with corresponding specialized illuminators is provided in a dual compartment container that eliminates internal light reflection problems by separating each camera and corresponding illuminator while combining each camera with an alternate illuminator, rendering the system more accurate, yet more compact and suited to unobtrusive placement. Considerable heat is generated by the specialized illuminators, requiring a heat sink to preserve illuminator life expectancy and to prevent the adjacent cameras from being adversely affected by the heat. Another feature enabling the system to work in its compact form despite the heat from the illuminators is that the protective case itself is adapted to be a heat sink for the illuminators.