Showing papers on "Image sensor published in 1972"

Multispectral data sensor and display system

Abstract: Apparatus is disclosed for displaying images derived from image sensors sensitive to radiation of different spectral bands In an illustrative embodiment of this invention, a first sensor is responsive to radiation in the visible band, whereas a second sensor is responsive to radiation images in the infrared (IR) band; video signals derived from the first and second sensors are displayed upon a suitable display device such as a color cathode tube (CRT) In accordance with the teachings of this invention, the video signals from the first sensor are processed and applied to the color CRT to provide a black and white display image in the absence of a video signal from the second sensor The video signal derived from the second sensor is processed and applied to the color CRT to display the sensed infrared image in various visual colors (or wave-lengths of radiation) dependent upon whether the portions of the viewed infrared image are ''''warmer'''' or ''''cooler'''' than a preselected reference point For example, warmer objects within the viewed scene may be displayed as red, whereas cooler objects may be displayed as blue or green Suitable gain control is associated with the video signal derived from second sensor to insure that the presentation of the color image upon the CRT is independent of the visual video signal derived from the first sensor In an illustrative embodiment of this invention, a DC signal is derived indicative of the amplitude of the first video signal and is used to control the gain of the IR video signal

Charge transfer circuits

Abstract: Apparatus to increase signal-to-noise ratio of output signals from a charge transfer circuit. Video signals from a charge transfer image sensor array are increased in amplitude by combining light responsive charges of selected sensor elements. Circuitry is arranged to provide summation of signals from, for example, adjacent sensor array elements.

Solid-State Acoustic Image Sensor

Abstract: Some ultrasonic imaging systems with lens system for underwater use have been studied1,2,3. An ultrasonic imaging system utilizing a piezo-electric transducer array converter has been developed4.

Gated holographic coding system for reducing alignment requirements

Abstract: Holographic techniques are used to encode and decode information. The image of a point source of light is used to trigger an image sensor into detecting the decoded information when the relative encoding coordinates between a code plate and hologram are reestablished in a decoding apparatus.

Leakage current compensating circuit for semiconductor image sensor

Abstract: A compensating circuit for leakage current comprising part of a signal from a semiconductor image sensor is provided in which a diode is positioned in thermal contact with the image sensor and is reverse biased to produce a leakage current proportional to the image sensor leakage current. Amplifying means is utilized to provide a diode leakage current signal proportional to the leakage current flowing through the diode and equal to the leakage current component of the image sensor signal. The diode leakage current signal and the image sensor signal are summed in a summing circuit such that the diode leakage current signal offsets the leakage current component of the image sensor signal. An output signal results in which the image sensor leakage current component is substantially eliminated.

A low-light-level self-scanned MOS image sensor

Abstract: A low-light-level self-scanned MOS image sensor using new signal processing and scanning techniques to eliminate completely switching transient noise from the array output has been developed.

Charge-coupled device (CCD) imaging at low light levels

Abstract: We present the analysis, design, fabrication and evaluation of low light level, anti-blooming, charge-coupled device (CCD) image sensors in line and area arrays. The transfer of low light level charge is determined by the non-linear electric field beneath the gate electrode. The CCD image sensor array is analyzed with a figure-of-merit which is the product of signal-to-noise (S/N) and modulation transfer function (MFT). The noise equivalent signal (NES), S/N = 1, is formulated at the system output and referenced to the readout diode. The CCD arrays use a 2-phase, stepped-oxide, clock system with interline transfer. Front surface imaging is achieved with thin silicon-gate electrodes (1000-2000 A) which also serve as a "field shield" and the bottom layer of the lower phase line. The lowerphase line is constructed with an aluminum-silicon sandwich to provide low charging time constants (< 5 nsec) and reduce the incidence of phase line-to-line substrate shorts over large areas. The upper phase line is aluminum and a 3rd level aluminum forms a light shield over the interline shift-registers and CMOS readout circuit. The latter in combination with an analog signal processor provides a low-noise, composite video output signal. A unique cell design is used to combine active CCD sensor, interline shift-register, transfer gate and "stopper" diffusions into compact 2 mil centers in the area array. 1 × 128 element line arrays and 75 × 100 element area arrays are discussed in terms of individual elements NES, responsivity and spectral response.

A Self-Scanned Ferroelectric Image Sensor

Abstract: A prototype imaging system consisting of a monolithic sensor array of pyroelectric elements has been constructed which is capable of imaging visible, infrared and x-radiation. The image sensor is a true flat-panel, self-scanned device which generates a video picture of radiation intensity patterns at the usual television rate of 30 frames per second. The detector material is ceramic lead-zirconatc-titanate. which has an individual spot responsivity of 1 ViW. The video Information is extracted from the sensor mosaic by digital scanning and video coupling circuits which are connected to the array by row and column address electrodes. The electronic circuitry consists of low cost. low power integrated circuits. The initial prototype system incorporates a 5 x 5 element sensor matrix and a large scale device composed of' an array of 2500 spots is currently under construction.

Optical design of an imaging spectral radiometer for earth resources applications.

Abstract: Description of the optics, thermal compensation measures, and calibration procedures for a scanning imaging spectroradiometer to be used in earth resources sensing applications. The spectral range covered extends from 4000 to 8500 A. Two possible modes of operation include (1) a high-spatial-resolution terrestrial survey mode with moderate spectral resolution, and (2) a high-spectral-resolution ocean survey mode with decreased spatial resolution. Two high-aperture f/1.4 objective lenses (providing fields of view of 10 and 25 deg) are interchangeable to give added flexibility in planning experiments with this instrument. A diffraction grating disperses the spectrum which is then scanned by the image sensor.

A self-scanned ferroelectric image sensor

Abstract: A prototype imaging system consisting of a monolithic sensor array of pyroelectric elements has been constructed which is capable of imaging visible, infrared and x-radiation. The image sensor is a true flat-panel, self-scanned device which generates a video picture of radiation intensity patterns at the usual television rate of 30 frames per second. The detector material is ceramic lead-zirconatc-titanate which has an individual spot responsivity of 1 V/W. The video information is extracted from the sensor mosaic by digital scanning and video coupling circuits which are connected to the array by row and column address electrodes. The electronic circuitry consists of low cost, low power integrated circuits. The initial prototype system incorporates a 5 × 5 element sensor matrix and a large scale device composed of an array of 2500 spots is currently under construction.

Design and Performance of Silicon Integrated Imaging Sensor Incorporating Self-Scanning Integrated Circuits

Abstract: 蓄積モードを利用したSiの100×100撮像ICを設計, 試作し, その特性を調べた.フォトダイオードと2つのMOSTからなる絵素をマトリックス状に構成したデバイスが, 水平および垂直の2つの走査パルスで順次切換えられて映像信号を発生する.この論文では (1) MOSTとフォトダイオードの組合せよりなる絵素の蓄積モードの解析, (2) 走査パルスの印加に伴って出力側に発生するスパイク電流の減少, (3) 以上の考察から設計, 試作された10,000絵素のデバイスが60Hzのフレーム周波数で感光面上約1～101xのイメージを残像なしに撮像できる特性, などの点を中心に検討する.

Charge coupled frame transfer imaging devices with interlaced readout and blooming suppression

Abstract: A charge coupled image sensor to be used in conventional television applications has to be read out in two progressively scanned, 2:1 interlaced fields. A difficulty arises in frame transfer imaging devices, since they are basically shift registers that move the whole charge pattern in unison. A modified form of interlacing has been devised which offers a resolution per scan line in the display that is comparable to what is produced in an electron beam scanned arrangement. Each charge transfer cell is elongated in the vertical direction to cover the distance corresponding to two scan lines in the display. The information to be presented in two consecutive fields is integrated underneath different sets of electrodes, within this stretched resolution cell, to match the center of charge collection with the corresponding location of the scan line in the display. Several implementations of this scheme have been tested experimentally and compared to the theoretical resolution limit.

Solid-State Scan Mosaic Sensors.

Abstract: : A 512 x 512 element photoconductive image sensor with integrated thin-film scanning decoders has been built and scanned at 30 frames per second on laboratory test equipment. Spurious signals due to switching transients and defects in the decoders gave a poor quality picture. A parallel research effort on a 32 x 44 element silicon photodiode sensor which is scanned internally by bucket-brigade charge transfer registers has yielded very encouraging results. Switching transients are low and can be readily separated from the video signal. Sensitivity and uniformity are excellent because all charges are transferred with low loss through an output register to an amplifier located on the same chip. A bucket-brigade vertical scan generator drives the gating circuits which connects the horizontal clock voltages to each row in sequence. A small solid-state camera has been built incorporating the 32 x 44 element sensor. Its dimensions are 2.25 in. x 2.75 in. x 3.75 in. and it consumes less than 1 W of power. (Author)

Improved image position sensor for high resolution optical tracking.

Abstract: The narrow beamwidth of a laser source can provide advantages, relative to a microwave source, in applications such as short range, high angular resolution trackers. In such applications, an image position sensor (IPS) is used which senses the angle of arrival of the optical radiation from the target. It is shown analytically and empirically that, in the case of a rotating mirror IPS, cross coupling between azimuthal and elevation channels as well as nonlinear and saturation effects result when the image displacements on the rotating mirror are large compared to the image size. The performance of the rotating mirror IPS and consequently that of the tracker has been greatly enhanced by incorporating a computer generated variable density spatial filter (VDSF) in front of the rotating mirror.