Other

USA As Represented by Secretary of the Navy

US Government As Represented by the Secretary of the Army

Richard H Vollmerhausen

Robert S Rohde

Edwin W Wentworth

J Brian Gillespie

William M Decker

Jack L Kimberly, Jr

Robert G Branigan

The invention implements room temperature imaging of a photovoltaic diode image array operating in any spectral band (visible through extreme thermal). The invention also operates the photo diodes at zero bias voltage and thus eliminates 1/f (burst) noise and dark current. And the invention simplifies the electrical-mechanical interface between the readout integrated circuit (ROIC) and the photodetector array and minimizes the component count on the ROIC. These advantages are realized by multiplexing the photocurrents from each photodiode in the array according to an orthogonal or biorthogonal code set. The multiplexed current is supplied to an op amp such that zero bias is maintained for the photodetector array. The code set also allows the photocurrent generated by each photodiode to be recovered.

Photovoltaic image array operation at zero bias voltage to eliminate 1/f noise and dark current

This Orthogonal Code Readout (OCR) electronically expands the dynamic range of CMOS active pixels by adding digital electron wells. The dynamic range of an active pixel is not limited by in-pixel capacitance. When employed as a thermal array readout, OCR simplifies thermal detector array fabrication by eliminating the need for large electron well capacitors. OCR also improves digital quantization beyond that provided by hardware digitizers.

Focal plane arrays using an orthogonal code readout

Methods for design and production of highly sensitive active and passive light detecting devices and systems. Orders of magnitude improvement in optical signal detection is made possible in high noise or low contrast scenes. The current invention creates a small spectral difference between two parts of a split light stream. When recombined, the altered light streams partially correlate, and that generates fall amplitude signal oscillation at a frequency that depends on the constituent spectrum. The full amplitude signals and spectrum dependent oscillation make signal discrimination much better than intensity-only methods. The effect of read noise, amplifier noise, dark current noise, and thermal noise due to photo detector shunt resistance, become less important when compared to light detection using prior art methods.

Enhanced light detector

A method for generating a color image. The method comprises collecting a color image of a scene, the color image comprising three color slice images, each one comprising color image pixels, and collecting an achromatic image of the scene, the achromatic image comprising achromatic image pixels. The achromatic image having a higher resolution than the color image. The achromatic image is presented on a first screen comprising a white phosphor. The color slice images are processed to reduce noise, to increase a signal-to-noise ratio, to increase contrast, and/or to normalize the pixel intensity values in each color slice. The color image is presented on a semi-transparent screen or display. The semi-transparent screen is situated between an observer and the achromatic image on the first screen. An optical component is used to view an image on the first screen through the semi-transparent second screen.

Color night vision goggle

A system for fusing a direct image and a reflective image. The system comprises a first image sensor sensing the direct image from a scene where the direct image comprises direct image pixels. A second image sensor senses the reflective image from the scene where the reflective image comprising reflective image pixels. A component spatially registers the direct image pixels and the reflective image pixels. A digital processor fuses an intensity value of each direct image pixel and an intensity value of an aligned or registered reflective image pixel to generate a fused pixel value, where a plurality of fused pixel values forms a fused image that is displayed on a monitor.

Fusion of thermal and reflective imagery

This disclosure describes implementation of a display with resolution of one to ten million color pixels per square inch of display area. Fabrication in a CMOS foundry uses silicon waveguide technology. Red, green, and blue light are distributed via waveguide to all display pixels. Optical modulators in each pixel control image color and luminance. A photo diode is incorporated into each display pixels to enable uniformity correction of pixel luminance and color.

Waveguide display

Plane Wave Imagers (PWI) directly sense the amplitude and phase of electromagnetic waves and do not require a lens to image a scene. PWI's can also be used in the exit pupil of an afocal lens. PWI's are implemented in CMOS using silicon waveguide technology. Since the wavelength of light ranges from less than one to tens of microns, PWI's fabricated on silicon are essentially flat plates, making a PWI a thin and light structure. A CMOS PWI can operate in the visible, near infrared, short wave infrared, and mid wave thermal spectral bands. Benefits of using a PWI include the ability to achieve large optical aperture performance by digitally processing the outputs of multiple small aperture PWI's that are not necessarily precisely optically aligned. Enhanced scene resolution can be obtained by collecting imagery from several adjacent positions and then digitally combining the digital data into one large dataset.

Plane wave imager with synthetic aperture capability

A heterodyne starring array active imager for producing an image. The imager comprises a light source and a component for segregating the light into frequency bands, each band intermittently illuminating a region of a scene and an array of light collecting sites, each comprising: a coupling component optically coupling scene light into a first waveguide and a local oscillator light coupled into a second waveguide. First and second waveguides coupled to a third waveguide with scene light and local oscillator light propagating into the third waveguide. A square law photo detector at each light collecting site receives the merged light for heterodyning the scene light and the local oscillator light. Components receive and process the heterodyned light from the photo detectors to produce a frame signal for each light collecting site. A read-out device produces an array signal responsive to the frame signal from each light collecting site.

Heterodyne starring array active imager with spread spectrum illuminator

A system for creating and displaying a color image having a higher resolution than a source color image. The system comprising a first sensor for sensing electromagnetic energy in a first spectral band to generate an achromatic image of achromatic image pixels. A second sensor for sensing electromagnetic energy in a second spectral band to generate a color image comprising a triad of color pixels. A digital processor interpolates the color triad pixels to achieve a count of color triad pixels equal to a count of achromatic image pixels. The digital processor fuses each color triad pixel, pixel by pixel, with an achromatic image pixel to produce fused color pixels. A display responsive to the fused color pixels displays a color image of the scene.

Resolution enhancement of color images

A heterodyne starring array active imager for producing an image. The imager comprises a light source intermittently illuminating a scene and an array of light collecting sites imaging the scene, each one comprising: a coupling component optically coupling scene light into a first waveguide and a local oscillator light coupled into a second waveguide. The first and second waveguides coupled to a third waveguide such that the scene light and local oscillator light propagate into the third waveguide. A square law photo detector associated with each light collecting site receives the merged light for heterodyning the scene light and the local oscillator light. Components receive and process the heterodyned light from the photo detectors to produce a frame signal for each light collecting site. A read-out device produces an array signal responsive to the frame signal from each light collecting site.

Heterodyne starring array active imager

The invention provides an array of standard infrared aiming lights mounted n an aircraft and used occasionally by pilots wearing infrared goggles to enhance perception of terrain features on low flying missions.

Terrain cueing

Dichroic mirrors employed in an optical seeker system to achieve spectral scrimination. The dichroic mirrors are aligned so as to produce a reticle phase difference between different wavelengths of reflected optical energy. Background optic energy is spectrally balanced so no net guidance is given to the seeker.

Growing community of inventors

Lake Mary, FL, United States of America

Richard H Vollmerhausen