Texas Instruments Corporation

Kent McCormack

William M Knight, Jr

Dana Dudley

James E Robinson

Dane A McNeill

A visible light and near infrared imaging device is disclosed. The imaging device comprises X-Y addressing means, an array of opto-electronic semiconductor elements or cells, a multiplexer, a precharge switch, and an amplifier. The X-Y addressing means selectively addresses each cell of the array of opto-electronic semiconductor cells and corresponding multiplexer switch for connecting a reference voltage to each cell to charge each element to the reference voltage, then to isolate each element and vary its voltage in proportion to the intensity of the impinging light, and finally to read out selectively the voltage of each element to the amplifier for amplifying the electrical signals representative of the light intensity to a working level for processing into video signals.

Visible light and near infrared imaging device

An improved ferroelectric imaging system comprises a chopper, lens system, ferroelectric detector matrix, anistropic heat sink, switching matrix, temperature controlled heat sink, drive and read out electronics, video processor, and display. The chopper interrupts infrared energy emanating from a scene, and the lens system focuses the chopped infrared energy on the ferroelectric detector matrix which produces electrical signals representative of the infrared energy impinging thereon. The signals are read out by the drive and read out electronics whose action is synchronized with the chopper action, processed in the video processor and displayed by the display. The ferroelectric detector matrix is a plurality of detector capacitor elements whose lower plates are metal pads formed on the lower surface of the dielectric which is a wafer of ferroelectric material. The switching matrix includes a corresponding plurality of solid state switches operatively connected to output pads, a bias source, and the drive and readout electronics. The anisotropic heat sink includes a plurality of spaced conductor rods of a preselected cross-sectional area and length. The conductor rods are grown on the output pads of the solid state switches and the lower plate capacitor pads are bump bonded to their ends. The conductor rods are either vacuum packed or glass packed depending on their mechanical strength to support the detector matrix. The conductor rods are formed by coating the switching matrix with a photoresist, patterning the photoresist, and electrodepositing metal in the pattern of photoresist. Additional layers are used where necessary to achieve the preselected length. The photoresist is then removed to leave the conducting rods in a spaced relationship. To provide additional mechanical strength the conductor rods are refilled with a glass filled photoresist, the photoresist exposed and removed to leave the glass particles which are sintered to provide a glass frit support for the conductor rods.

Ferroelectric imaging system

An improved ferroelectric imaging system comprises a chopper, lens system, ferroelectric detector matrix, switching matrix, drive and readout electronics, video processor and display. The chopper interrupts infrared energy emanating from a scene, and the lens system focuses the chopped infrared energy on the ferroelectric detector matrix which produces electrical signals representative of the impinging infrared energy. The signals are read out by the drive and read out electronics whose action is synchronized with the chopper action, processed in the video processor and displayed by the display. The ferroelectric matrix comprises a plurality of detector capacitor elements fabricated by forming a metal surface on the upper surface of a dielectric of ferroelectric material and a plurality of metal pads arranged in rows and columns on its lower surface. Said metal plate forming the upper plates for the capacitors and the metal pads forming the lower plates. The upper plate is connected to busbars for biasing. The switching matrix includes a plurality of solid state switches arranged in rows and columns. The switches have elements operatively connected to the lower plates of the detector capacitor elements, a sense line for each row, and x and y address lines of the drive and readout electronics. The drive and readout electronics action is synchronized with the chopper action to provide the sense line with a signal representative of the infrared energy impinging sequentially on each detector capacitor element for processing and display.

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Richardson, TX, United States of America

Kent McCormack