Showing papers on "Image sensor published in 1971"

Self-scanned image sensors based on charge transfer by the bucket-brigade method

Abstract: Solid-state image sensors which are internally scanned by charge transfer offer a potentially usefull alternative to sensors based on x-y addressing. The application of charge transfer to solid-state scanning introduces sensor design problems which are common to either the "bucket-brigade" or "charge-coupled" approach. Two-dimensional and single-line sensors employing bucket-brigade scanning have been built and evaluated. Problems discussed include transfer efficiency, video signal extraction, vertical scanning, and spurious effects. The use of the bucket-brigade shift register as a scan generator for x-y addressing is also described.

Video signals and switching transients in capacitor-photodiode and capacitor-phototransistor image sensors

Abstract: A new configuration of the capacitor-photodiode type of image sensor is described which results in appreciable reduction of switching transients at the sensor's output. The modification consists of replacing the photodiode by a phototransistor operating in the common base configuration. A 32 × 32 element array capable of operating in either the photodiode or phototransistor mode was fabricated. The dynamic range, transfer characteristic, and switching transient voltage were calculated for both modes and compared with experiment. For the experimental array an order-of-magnitude improvement in signal-to-noise ratio has been realized in the transistor mode of operation.

Noise Characteristics of Bragg Imaging

Abstract: The effect of Brillouin scattering on the image quality of a Bragg-imaging system is analyzed in this chapter. The particular Bragg-imaging system considered here uses a cylindrically convergent illuminating light beam. The signal-to-noise ratio for an image element (that is, a resolution cell) is shown to vary with the image-plane location when the image sensor is broadband in temporal frequency. It is also shown that quantum noise due to light scattered from thermal phonons (Brillouin scattering) is the dominant limiting source of noise for a Bragg-imaging system operating in the ultrasonic band at room temperature when the best available TV camera tube is used for detecting the image. Competing noise sources which are evaluated include quantum noise due to signal photons and image sensor noise. The effects of dust particles and other inhomogeneities on scattered light are not considered.

Interfacing Photodiode Array Cameras To Microcomputers For Quality Control

Abstract: Optical sensors are rinding increased usage in inspection and quality assurance applications. The versatility and high speed data gathering capabilities of imaging sensors lend themselves to complex applications such as pattern recognition and gray-scale defect deter-minations. Applications of this type usually require computer capability to mandLutte and digest the data but optical scanning rates usually outpace the instruction cycle rates of microcomputers. This paper discusses a method of handling high speed imaging data to pro vide real time computer analysis, decision and control. Methods and technical designs are described that provide data compression, formatting and preprocessing. Hanipulative tech.- niques for both digital and analog (video) signals are discussed.

Image sensors based on charge transfer by integrated bucket-brigades

Abstract: Image sensors which are internally scanned by bucket-brigade or charge-coupling offer the opportunity fcr improved signal-to-noise ratio and ease of fabrication over conventional x-y addressed sensors. A completely-integrated self-scanned bucket-brigade sensor having 32 × 44 elements spaced on 3 mil centers has been built. As few as nine leads are required for scanning and signal output, High signal-to-noise ratio and reduction of spurious switching transients are possible by the transfer of all elemental charges to a single output terminal whose capacitance is no more than that of each elemental capacitor. A 32-stage bucket-brigade shift register is used as a vertical scanner for gating the horizontal clock drives to successive lines. Operating characteristics will be described and compared with published data on x-y addressed and charge-coupled sensors.

A multispectral image sensor array

Abstract: A silicon monolithic multispectral photosensor device is described. Fabrication techniques and preliminary spectral response data are presented.

Surface charge transistor imaging array

Abstract: Surface-charge transport offers the possibility of achieving both high sensitivity and high image cell density while requiring only a small number of connections to the imaging array itself. The high sensitivity is achieved by allowing the charge-storage reservoirs to integrate the image for an appropriate time which is long compared to the time required for read out. High sensitivity is maintained if part of the array can be read out at the same time that the remainder of the array is integrating the optical image.